JP3013881B2 - Hybrid inflator with coaxial chamber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an inflatable safety system for a motor vehicle, and more particularly to a hybrid inflator capable of rapidly inflating an air / safety bag.

[0002]

2. Description of the Related Art With the development of inflators for inflatable safety systems for motor vehicles, inflators dedicated to pressurized gas, propellants, and hybrid inflators have been developed. Of course, there are many possible designs for each of the above inflators. In all three systems, the primary design requirement is that the air / safety bag must be inflated by a predetermined amount at a predetermined time in order to operate effectively.

In many cases, the weight of the motor vehicle is an important design requirement, and the weight of the inflator is also an important requirement. In addition, because space is limited in the design of many motor vehicles, the size of the inflator is also an important design requirement.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to rapidly mix and burn a propellant gas and a pressurized medium under pressure in order to inflate an airbag.

[0005]

In order to achieve the above object, in a first embodiment of the present invention, a pressurized medium is contained in an inflator housing. A gas generator housing is connected to the inflator housing, the gas generator housing including a first chamber containing a propellant, and an ignition assembly for igniting the propellant. Further, the gas generator housing includes a second chamber, an outlet, and a main closure disk, the second chamber communicating with the first chamber and the inflator housing and providing the propellant gas generated from the ignited propellant. Combustion by pressurized medium. An outlet is provided in the gas generator housing for supplying the pressurized medium and propellant gas from the second chamber to an air / safety bag. The main closure disc always closes its outlet and is destroyed after ignition of the propellant. The first chamber, the second chamber and the main closing disk are arranged on the same axis in this order. The gas generator housing has at least one bleed port for keeping the internal pressure of the inflator housing and the first chamber substantially equal.

In a second embodiment of the present invention, an inflator housing containing a pressurized medium is provided.
The gas generator is connected to the inflator housing. The gas generator has a first chamber and a second chamber communicating with each other, a propellant housed in the first chamber, at least one bleed port communicating the first chamber and the inflator housing, a second chamber and At least one gas generator inlet communicating with the inflator housing, and at least one gas generator outlet. The main closure disk is located between all said gas generator outlets and the air / safety bag. A propellant ignition assembly is associated with the gas generator and ignition of the propellant forms a propellant gas. Means are provided for opening the main closure disc to initiate flow to the air / safety bag, the opening means having means for burning the propellant gas in the second chamber, wherein the propellant gas is on the main closure disc. Acts directly.

In the second embodiment, in order to reduce the size of the hybrid inflator, it is preferable that the first chamber, the second chamber, and the main closing disk are arranged on the same axis in this order. .

Further, in each of the embodiments, it is desirable that the ignition assembly includes an initiator. Preferably, the ignition assembly includes an initiator and a sub-closing disk which always interrupts communication between the first chamber and the initiator, and the sub-closing disk is preferably disposed on the axis. The ignition assembly may also include an initiator, a booster agent ignited by the initiator, and a secondary closure disk that always interrupts communication between the first chamber and the initiator and is destroyed when the booster agent ignites. It is possible. In this case, the booster agent and the secondary closing disk are arranged on the axis.

It is preferable that the pressurized medium is housed in the inflator housing so as to surround the gas generator housing. In this case, the space in the inflator housing can be used effectively.

It is even more preferable that the inflator housing includes a donut-shaped high-pressure gas housing and the gas generator housing has a substantially cylindrical shape in order to effectively use the space. In this case, the high-pressure gas housing is arranged around the gas generator housing.

The first chamber and the second chamber are separated by a dome-shaped partition, and the ignition assembly is disposed inside the first chamber so as to be close to the partition, and has a periphery of the ignition assembly. It is preferable that the propellant is disposed at the bottom. Also in this case, the space in the inflator housing can be effectively used, and the size of the entire inflator housing can be reduced.

It is preferable that the partition has a plurality of vents communicating with the first chamber and the second chamber, and the vents are arranged to be inclined with respect to the axis. In this case, a vortex can be formed by the gas passing through the vent, and the room into which the gas flows can be sufficiently stirred.

In order to reduce the size of the hybrid inflator, the capacity of the inflator housing should be approximately 50c.
m ³ to about 150 cm ^3, it is preferable volume of the first chamber from about 5 cm ³ to about 15cm ^3, and the capacity of the second chamber is about 1 cm ³ to about 20 cm ^3.

The second chamber has a plurality of inlets for introducing the pressurized medium into the second chamber, each inlet being arranged to intersect a line extending radially from the axis. Is preferred. In this case, a vortex can be formed by the gas passing through the inlet, and the room into which the gas flows can be sufficiently stirred.

In the second chamber, after the ignition assembly is actuated, the inflator housing and the gas generator housing pass through the inlet until the pressure in the inflator housing exceeds the pressure in the gas generator housing by a predetermined amount. Preferably, there is provided a valve means operable in cooperation with said inlet to substantially prevent flow therebetween. In this case, the pressurized medium in the inflator housing is prevented from flowing into the gas generator housing while the pressure in the gas generator housing is relatively low.

The inflator housing and the gas generator housing may be formed in a substantially cylindrical shape, the gas generator housing may be housed in the inflator housing, and both ends of the inflator housing may be connected to both ends of the gas generator housing. It is. In this case, the entire hybrid inflator is formed in a small size so as to have a cylindrical shape.

In the cylinder type hybrid inflator, it is preferable that an aspirator nozzle is provided between the first chamber and the second chamber. The aspirator nozzle injects the propellant gas toward the main closure disk.

[0018] The second chamber may have an inlet near the aspirator nozzle for introducing the pressurized medium into the second chamber. In order to reduce the size of the hybrid inflator, it is desirable that a portion of the inlet and the tip of the aspirator nozzle which is closest to the outlet is separated from the outlet by 4 mm to 80 mm.

In the second chamber, after the ignition assembly is actuated, the inflator housing and the gas generator housing pass through the inlet until the pressure in the inflator housing exceeds the pressure in the gas generator housing by a predetermined amount. It is also possible to provide valve means operated in cooperation with said inlet to substantially block the flow between them. The valve means may be formed from a flexible material and arranged to surround the aspirator.

In the first chamber, there is provided a transmission tube located on the axis line, the tube being connected to the aspirator nozzle, and having a plurality of holes communicating the inside of the tube with the first chamber. It is desirable to have. In this case, it is possible to increase the flow velocity of the gas passing through the plurality of holes.

To reduce the size of the cylinder-type hybrid inflator, the capacity of the inflator housing is about 150 cm ³ to about 450 cm ³ , the capacity of the first chamber is about 10 cm ³ to about 40 cm ³ , and the second chamber is Is preferably about 1 cm ³ to about 50 cm ³ .

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. The present invention relates to a hybrid inflator for an inflatable safety system of a motor vehicle. That is, the present invention relates to an inflator that utilizes both a stored pressurized gas and a gas and / or heat generating propellant. Various hybrid inflators are disclosed in U.S. Pat. No. 5,230,531 to Hamilton et al.

FIG. 1 shows an overall view of one embodiment of an inflatable safety system for a motor vehicle. Inflatable safety system 10
Are the detector 14, the inflator 26 and the air / safety bag 18. Detector 14 detects a condition that requires inflation of air / safety bag 18 (eg, a predetermined deceleration).
Is detected, a signal is transmitted to the inflator 26 and gas or other suitable fluid is released from the inflator 26 via line 22 to the air / safety bag 18.

The inflator 30 shown in FIG. 2 is a hybrid inflator and can be used in place of the inflator 26 in the inflatable safety system 10 of FIG. Accordingly, the inflator 30 supplies a bottle or inflator housing 34 having pressurized medium 36 to be supplied to the air / safety bag 18 (FIG. 1) at the appropriate time, and supplies a propellant to the air / safety bag.
A gas generator 82 is provided to increase the flow to the safety bag 18 (eg, by heating to expand the pressurized medium 36 and / or to generate additional gas). As described in more detail below, a gun-type propellant (eg, a high-temperature multi-fuel propellant) is used to form the propellant grains 90 located in the gas generator 82, and the pressurized medium 36 includes at least one non- A mixture of an active gas (eg, argon) and oxygen has been used. Pressurized medium 36 desirably includes from about 70% to about 92% inert gas and from about 8% to about 30% oxygen on a molar basis. More preferably, it contains from about 79% to about 90% inert gas and from about 10% to about 21% oxygen on a molar basis.

The inflator housing 34 and the gas generator 82 communicate with each other, and the gas generator 82 is disposed inside the inflator housing 34 to reduce the space required for the inflator 30. More specifically, the hollow boss 66
A hollow diffuser 38 is welded to one end (e.g., about 1.25 inches (3.18 cm) in diameter). The diffuser 38 has a plurality of rows of discharge holes 40 (e.g., 80 discharge holes 40 each having a diameter of about 0.100 inches (0.254 cm)) through which "non-thrust output" is provided from the inflator 30. The screen 58 is provided adjacent to the discharge hole 40. A closure disc 70 is suitably positioned inside the boss 66 and initially welded to the boss 66 to initially retain the pressurized medium 36 within the inflator housing 34. When gas release is required, a projectile 50 having a substantially conical head is closed
Propelled to penetrate zero. More specifically, the projectile 50 is located on the convex side of the closure disk 70 in the barrel 54 and upon receiving the appropriate signal from the detector 14 of the inflatable safety system 10 (FIG. 1), activation of the initiator 46 Will be promoted. Initially, a ring 62 is provided to hold projectile 50 in the proper position before ignition.

An orifice sleeve 74 is welded to the end of the closure disk 70 and / or boss 66. The orifice sleeve 74 is hollow and includes a plurality of orifice ports 78 (e.g., each having a diameter of about 0.201 inch (0.5.
511 cm) with four orifice ports 78)
When the closure disk 70 is ruptured by the projectile 50, the interior of the inflator housing 34 communicates with the interior of the boss 66 and diffuser 38. Further, the gas generator 82, more specifically, the gas generator housing 86 is welded to the orifice sleeve 74 to complete the communication between the inflator housing 34 and the gas generator 82.

The gas generator housing 86 contains a plurality of propellant grains 90 which, when ignited, provide the combustion product gases of the heated propellant to increase flow to the air / safety bag 18 (FIG. 1). Supply. The propellant grains 90 are held inside the gas generator housing 86 by a propulsion sleeve 94, which is
A gas generator inlet nozzle 98 at the end 96 of the gas generator housing 86 is isolated by a baffle and baffle 100. As described below, the propellant grains 90
Can be manufactured from gun-type propellants. However, the propellant grains 90 are substantially cylindrical, with one hole passing through the center. Other forms of propellant grains may be suitable, depending at least in part on the method of making the propellant used.

A single (or composite) gas generator inlet nozzle 98 (eg, about 0.516 inch (1.3 inch) in diameter
1 cm) suction nozzle 98) is located in the gas generator housing 8
6 and is typically oriented away from the closure disk 70. The gas generator housing 86 also has a plurality of circumferentially spaced outlets or discharge nozzles 200 on its side walls (eg, each having a diameter of about 0.221 inches (0.561 cm)). 1
4 rows of ejection nozzles 200). It may be desirable to change the axial position of these discharge nozzles 200 (usually located in the middle of the gas generator housing 86),
The effect is enhanced by the position close to the outlet. Furthermore,
It may be desirable to change the number of ejection nozzles 200. The discharge nozzle 20 is provided on the side wall of the gas generator housing 86.
0 and a suction nozzle 98 at the end 96 of the gas generator housing 86, the propellant grains 90
During the combustion of the gas, the pressurized medium 36 is drawn into the gas generator housing 86 via the suction nozzle 98, and the mixed gas from inside the gas generator housing 86 is discharged from the discharge nozzle 200.
Out of the gas generator housing 86 via More specifically, a pressure difference is generated due to the flow of the pressurized medium 36 near the side wall of the gas generator housing 86, whereby the pressurized medium 36 is transmitted through the suction nozzle 98 to the gas generator housing 8.
It is drawn into 6. As will be described in more detail below, this greatly improves the performance of the inflator 30 at least when producing certain types of propellant gases.

The gas generator 82 is provided with the propellant grains 9 in a timely manner.
An ignition assembly 114 for igniting 0 is provided. An ignition assembly 114 is disposed at least partially within the gas generator housing 86 between the projectile 50 and the propellant grains 90 and typically includes the working piston 12.
4, having at least one squib primer 120 and an igniter / booster agent 144 as activator. More specifically, the actuating guide 140 engages the end of the orifice sleeve 74 and the inner wall of the gas generator housing 86, so that the actuating guide 140
4 and at least partially fulfills the function of guiding the working piston 124. A primer holder 116 engages one end of the actuation guide 140 and contains a plurality of conventional firing primers 120 disposed substantially adjacent to the ignition / booster agent 144. Typically, the igniter / booster agent 144 is held adjacent to the squib 120 by a charge cup 148. A preferred example of an ignition / booster agent 144 is an RDX aluminum booster agent having a composition of 89% RDX, 11% aluminum powder and 0.5% hydroxypropyl-cellulose.
Cage 1 between the primer holder 116 and the propulsion sleeve 94
08 and the baffle 112 are arranged. If the gas generator housing 86 is attached to the orifice sleeve 74 by crimping rather than welding, it may have the property of extending during operation. Therefore, to ensure that the parts interact, for example, the retainer 108 and the baffle 11
2, a wave-shaped spring washer can be arranged (not shown).

The actuating piston 124 is slidably disposed within the actuating guide 140 and comprises one continuous projecting rim 128 substantially arranged on the firing squib 120.
As will be appreciated, a plurality of projecting members (not shown) may be used in place of a single substantially continuous projecting rim 128. A countersunk washer 136 is disposed (via the spacer 126) between the actuating guide 140 and the actuating piston 124 and engages a portion of both, and initially the actuating piston 12
The position of No. 4 is kept away from the strike and detonator 120.
As a result, the likelihood that the actuating piston 124 will erroneously engage the squib 120 and activate the gas generator 82 is reduced. However, after the projectile 50 has passed the closing disk 70, the energy transferred by the projectile 50 to the actuation piston 124 is sufficient to overwhelm the countersunk washer 136, and the projecting rim 128 has at least one It can be engaged with the firing squib 120 with sufficient power to ignite the squib 120. In turn, this causes ignition of the igniter / booster agent 144 and the propellant grains 90 ignite.

During operation of the gas generator 82, the firing squib 120
May be corroded, allowing propellant gas generated by the combustion of the propellant grains 90 to flow through the squib 120. Such propellant gas leaks can adversely affect the consistency of the performance of the inflator 30. However, such gas desirably acts on the working piston 124 and moves it into sealing engagement with the working guide 140. This results in a seal for the gas generator housing 86 that limits any gas leakage.
Accordingly, the propellant gas preferably flows through the gas generator suction nozzle 98.

To summarize the operation of inflator 30, detector 14 (FIG. 1) transmits a signal to initiator 46,
The projectile 50 is propelled. The projectile 50 first passes through the closure disk 70, opening the passage between the inflator housing 34 and the air / safety bag 18 (FIG. 1). The projectile 50 continues to advance and finally strikes the working piston 124, and the projecting rim 12 attached to the working piston 124
8 strikes at least one array firing primer 120.
As a result, the ignition / booster agent 144 is ignited, and then the propellant grains 90 are ignited. Gas generator housing 8
During combustion of the propellant grains 90 in 6, the pressurized medium 36 from the inflator housing 34 is drawn into the gas generator housing 86 via a suction nozzle 98 located at the end 96 of the gas generator housing 86. It is. This results from the flow of the pressurized medium 36 near the sidewall of the gas generator housing 86 and creating a pressure differential. This “pull-in” of the pressurized medium 36 promotes mixing of the propellant gas and the pressurized medium 36 within the gas generator housing 86. As described in detail below, this is particularly desirable when the pressurized medium 36 contains oxygen and reacts with a propellant gas that is rich in carbon monoxide and hydrogen. However, this gas is discharged from the gas generator housing 86 via the discharge nozzle 200 on the side wall of the gas generator housing 86. Thus, by mixing the pressurized medium 36 with the products of combustion from the gas generator housing 86, the flow to the air / safety bag 18 is advantageously increased (FIG. 1).

As noted above, the hybrid inflator 30 may use a mixture of oxygen and at least one inert gas for the gun-type propellant and pressurized medium 36 for the propellant grains 90. The gun type propellants used herein are high temperature multi-fuel propellants such as single base, double base or triple base propellants and nitramine propellants such as LOVA or HELOVA propellants.
More specifically, conventional gun-type propellants comprise about 2,500
~ 3,800 ° K, usually about 3,000
It is a propellant with a combustion temperature above ° K and is multi-fuel in that it generates large amounts of CO and H ₂ in the absence of excess oxygen. Normally, the in obtaining the CO ₂ and H ₂ O by reacting an excess fuel from these propellants, it is necessary to add 5 to 25 mole%, or sometimes 15 to 40 mole% of the oxygen pressure gas .

The propellant grains 9 of the hybrid inflator 30
One particular "conventional" gun-type propellant that may be used at 0 is HPC-96. It consists of about 76.6% nitrocellulose, about 13.25% nitrogen by weight, about 20.0% nitroglycerin, about 0.6% ethylcentralite, about 1.5% nitric acid Composition of barium, about 0.9% potassium nitrate and about 0.4% graphite, is a double base smokeless propellant.
HPC-96 is available in Wilmington, Delaware, USA.
available at Hercules, Inc. Although this double base propellant contains nitrocellulose as a major component, it produces the desired ballistic properties but fails to meet current automotive industry long term heat resistance criteria.

LOVA propellant (low brittle ammunition) and HE
LOVA propellants (high energy, low vulnerability ammunition) are another "conventional" gun-type propellant that can be used in propellant grains 90. This includes about 76.
0% RDX (hexahydrotrinitrotriazine), about 12.0% cellulose acetate butyrate, about 4.0%
Nitrocellulose (12.6% nitrogen), about 7.60
There is an M39LOVA propellant consisting of a composition of acetyl triethyl citrate and about 0.4% ethyl centralialite. The M39 LOVA propellant is available from The Naval Naval Battle Center in Indianhead, Maryland, USA
Surface Warfare Center) and available in Europe (Boforu Sweden) (Bofors), no excess oxygen is present when generating of H ₂ to about 32 mole percent CO and 30 mole percent. LOVA and HELO
VA propellants are preferred over existing double base propellants.
The latter does not pass the current US automotive industry heat resistance standards, while the former does. However, relatively high operating pressures are required for stable combustion of LOVA and HELOVA propellants. HPC-96
And HPC-96 despite the properties of the LOVA propellant
And LOVA propellants help illustrate at least some aspects of the principles / features of the present invention.

Due to the performance characteristics of gun-type propellants when used in forming propellant grains 90, coupled with the use of oxygen as part of pressurized medium 36, for example, the assignee of the present patent application Compared to current designs using 20-30 g of FN 1061-10 available from
It is possible to reduce the amount of propellant required for the gas generator 82 (the composition of FN 1061-10 is about 7.93% polyvinyl chloride by weight, 7.17%
Dioctyl adipate, 0.05% carbon black, 0.35% stabilizer, 8.5% sodium oxalate, 75% potassium perchlorate and about 1% lecithin. ). For example, a gun-type propellant that can be used to form propellant grains 90 typically has a total grain weight of about 1
It is in the range of 0 to 12 g (when used on the passenger seat side), preferably less than about 15 g. In this case, about 150-1
Preferably, 90 g of pressurized medium 36 is used with about 10-30% oxygen of pressurized medium 36 on a molar basis. More specifically, when about 169 grams of pressurized medium 36 is used with about 15% oxygen of pressurized medium 36 on a mole percent basis, the total weight of propellant grains 90 is about 1%.
0.4 g. When used on the driver's side, the desired / required amount of propellant grains 90 is about 5 g, and about 1.5 g when used in a side inflator.

The reduction in the amount of the gun-type propellant compared to the composition of the FN 1061-10 propellant can also be expressed as a weight ratio of the pressurized medium 36 to the total weight of the propellant grains 90. . Currently, FN 1061-1
0 propellant, the assignee of the present patent application is FN 10
A ratio of about 7.04 by weight of argon (i.e., high pressure gas and corresponding to pressurized medium 36 in accordance with the present invention) to weight of 61-10 propellant is used. With respect to the use of gun-type propellants, the weight ratio of pressurized medium 36 to the total weight of propellant grains 90 is about 10 to obtain an inflator having the same power, weight and dimensions as the inflator using FN 1061-10. 20, more preferably about 14-18, optimally about 15 or more. As will be appreciated, the use of hotter propellants can further increase these ratios and require less propellant. In this regard, the inflator is capable of producing output gas at a higher temperature than particle-loaded inflators, such as current state-of-the-art hybrid inflators, because essentially no hot particulate matter is present in the output gas of the gun-type propellant. Due to this temperature rise, the hot gas is relatively expandable,
Inflators are smaller and lighter. In addition to the foregoing, the structural dimensions and weight of the inflator can generally be reduced when using gun-type propellants. For example, 7.04 for a gun type propellant in an inflator
, The same output is obtained as when using the same rate of FN 1061-10, but the inflator with the gun type propellant is about 50% lighter than the inflator using FN 1061-10, and small. 7.
The ratio of 04 can be equally suitably used as described above regardless of whether it is used on the driver's seat side or in the side inflator.

The reduced amount of the gun-type propellant compared to the composition of the FN 1061-10 propellant indicates that the total gas output relative to the total weight of the propellant grains 90 (ie, the propellant gas and (Mixture with the pressurized medium 36). Currently, FN 1
For the 061-10 propellant, the assignee of the present patent application has used a ratio of about 0.192 gmol / g propellant for moles of output gas to propellant weight. In contrast, for a gun-type propellant for an inflator of the same power, weight and dimensions, the ratio of moles of output gas to the total weight of propellant grains 90 is typically about 0,0 g / g propellant. 35-0.6 gmol, more preferably about 0.4-0.5 gmol, optimally about 0.5 gmol. As mentioned above, in a hybrid inflator using a gun-type propellant and also using a ratio of 0.192 gmol / g propellant, the output of the inflator is FN
Same as a hybrid inflator using 1061-10, but with a weight and size reduction of the gun type propellant inflator of about 50%.

By using a plurality of gases for the pressurized medium 36, at least a gun-type propellant formation can be used for the propellant grains 90. Typically, the pressurized medium 36 comprises at least one inert gas and oxygen. Suitable inert gases include argon, nitrogen, helium and neon, of which argon is preferred. The oxygen portion of the pressurized medium 36 is multifunctional. Initially, the gaseous combustion products of the gun-type propellant of the propellant grains 90 react with oxygen to provide a heat source that causes the inert gas to expand. Thereby, the amount of propellant required for the gas generator 82 can be at least partially reduced. In addition, the reaction of oxygen with the propellant combustion products reduces the existing toxicity levels of the propellant gas to acceptable levels. For example, oxygen preferably converts a substantial portion of existing carbon monoxide to carbon dioxide (eg, at least about 85% of CO to CO ₂ ) and existing hydrogen to steam (eg, at least about 80% of H ₂ ). To H ₂ O) and a significant portion of the unburned hydrocarbons is removed as well (eg, at least 75% of the hydrocarbons are removed). Thus, the performance of the gas generator 82 is greatly improved as described above. That is, the pressurized medium 36 containing oxygen is caused to flow to the end 96 of the gas generator housing 86 by a pressure difference generated by the flow of the pressurized medium 36 near the side wall of the gas generator housing 86 having the discharge nozzle 200 on the side wall. Is drawn into the gas generator housing 86 via the suction nozzle 98 at. As a result, the pressurized medium 36 and the combustion products rich in CO and hydrogen of the gas generation source are mixed, and the total combustion efficiency of the gas generation source and the combustion products of the gas generation source and the pressurized medium 36 rich in oxygen are mixed. The burning rate of the mixing and propellant grains 90 is significantly improved. Then, gas is extracted from the discharge nozzle 200 on the side wall of the gas generator housing 86. Thus, the above configuration of the gas generator housing 86 significantly improves the performance of the inflator 30 (e.g., to mix oxygen and propellant gas quickly and efficiently).

Usually, the amount of at least one inert gas is about 70-90% on a molar basis and the amount of oxygen is about 10-30% on a molar basis. In general, it is desirable to use an amount of oxygen that exceeds that based on theoretical conversion. However, it is also generally desirable to have no more than about 20% (mole) oxygen in the output gas (ie, the mixture of propellant gas and pressurized medium).

The inflator 30 is assembled as follows. First, the gas generator 82 is assembled as follows. 1) Baffle 100 and screen 104 are inserted into gas generator housing 86 adjacent discharge end 96, 2) propulsion sleeve 94 is inserted into gas generator housing 86, and 3) propellant grain 90. 4) baffle 112 in gas generator housing 86 so as to be adjacent to the end of propulsion sleeve 94 in a direction opposite discharge end 96 of gas generator 82.
5) Insert the primer holder 116 with the ignition / booster agent 144 and the charging cup 148 into the gas generator housing 86;
0, insert the plate washer 136 and the working piston 124 into the gas generator housing 86. Thereafter, the various components are interconnected as follows. After the gas generator housing 86 has been welded to the orifice sleeve 74 and the projectile 50 and the initiator 46 have been placed in the diffuser 38, the diffuser 38 is welded to the boss 66 and a closing disc is provided between the boss 66 and the orifice sleeve 74. 70, and the boss 66 is welded to the inflator housing 34. With the above structure secured, the inflator housing 34
The pressurized medium 36 can be introduced into the inside. In this regard, in the case of multiple gases, argon and oxygen can be separately introduced into the inflator housing 34 via an end plug 42 welded to the end of the inflator housing 34 (e.g., first with argon and / or other , And then oxygen, or vice versa) or in a premixed state.

The following examples further serve to describe various features associated with using gun-type propellants in hybrid inflators. Example 1 The HPC-96 propellant described above was used to form a propellant grain 90 with a total weight of 18 g. Each propellant grain 90 has the shape shown schematically in FIG. 2 and is about 0.52 inches (1.32 cm) in length or thickness and about 0.3 mm in outer diameter.
It was 29 inches (0.737 cm) and had a thickness of about 0.105 inches (0.267 cm) (１ ／ the difference between the inner and outer diameters of the propellant grains 90). In addition, the HPC-96 propellant exhibited the following properties when ignited under air: Athletic power is 363,493 ft-lbs / lb, explosion heat is 1,062 calories / g, TV is 3,490 ° K, gas molecular weight is 26.7 g / mol, specific heat ratio is 1.21
96 and the solid phase density was 1.65 g / cm ³ . Based on theoretical calculations of normal composition, the composition of the gas, assuming combustion at gun pressure expanded to atmospheric pressure, is about 26.5% carbon monoxide, about 19.1% water on a mole percent basis. , About 26.2% carbon dioxide, about 13.7% nitrogen,
About 14.2% hydrogen and about 0.3% other gases.

The HPC-96 propellant grain 90, when exposed to a temperature of 120 ° C. in the industry standard Taliani heat resistance test, began to discolor within about 40 minutes and ignited within about 5 hours. This reduces the relevance of using HPC-96 propellant in propellant grains 90. that is,
One current industry standard specifies that propellants for inflatable safety systems do not degrade significantly when exposed to a temperature of 107 ° C. for 400 hours, and then ignite when exposed to the auto-ignition temperature. Because it is. However, HPC-
96 propellants are described herein to demonstrate certain principles of the present invention.

For HPC-96 propellant grain 90, about 169 g of pressurized medium 36 was provided in inflator housing 34 and comprised, on a mole percent basis, about 5% oxygen and about 95% argon. Inflator 30 has four orifice ports 78 on orifice sleeve 74, each having a diameter of about 0.676 cm.
(0.266 inch) and the diameter of the gas generator suction nozzle 98 was about 1.191 cm (0.469 inch). The discharge nozzle 200 was not provided on the side wall of the gas generator housing 86. Thus, the pressurized medium 36 was not drawn into the gas generator 82 during operation, and all discharges were performed through the suction nozzle 98.

The pressure fluctuation inside the inflator housing 34 during the operation of the inflator 30 was as shown in FIG. 10 communicated with the inflator 30
The internal pressure of the 0 liter tank is as shown in FIG. The gas output from the inflator 30 is about 1.2% carbon monoxide, about 1.5% carbon dioxide, about 2% or more hydrogen and about 60 ppm NO on a weight percent basis.
X. Thus, using the above proportions of oxygen and argon significantly reduced the amounts of carbon monoxide and hydrogen compared to the theoretical gas output of the HPC-96 propellant described above. In this example, without using radial holes,
Only one gas generator outlet was used.

Example 2 The procedure of Example 1 was repeated. However, the propellant grains 90 used 10.4 g of HPC-96 propellant and used about 164.4 g of pressurized medium 36 with a composition of about 15% oxygen and about 85% argon on a mole percent basis. . The performance curves when the inflator 30 is operated with these propellant grains 90 are shown in FIGS. The inflator 30 was shaped as discussed in Example 1. Further, the gaseous output from inflator 30 is about 2.4% carbon dioxide, about 1,000 ppm carbon monoxide, about 70 ppm on a mole percent basis.
Of NOX, containing hydrogen of NO ₂ and about 0ppm about 38 ppm. Therefore, the amount of carbon monoxide without NO and NO ₂ are increased so has greatly reduced by the increased amount of oxygen to 15% 5% Example 1. In addition, this greatly reduced the amount of propellant used.

EXAMPLE 3 The procedure of Example 1 was repeated twice using 16.4 g of HPC-96 and 169.0 g of pressurized medium 36 having a composition of about 15% oxygen and about 85% argon on a mole percent basis. Repeated. The performance curves of the inflator 30 were the same as in FIGS. 3 and 4, and the inflator 30 was shaped as discussed in Example 1. Furthermore, inflator 3
The gaseous output from 0 is about 1,000 ppm and 8 respectively.
00 ppm carbon monoxide, about 1.0%, 1.2% carbon dioxide, about 60 ppm, 50 ppm NOx, about 23 p
pm, contained 20 ppm of NO ₂ . Therefore, 15%
To increase the amount of oxygen, by that reducing the amount of HPC-96, the amount of carbon monoxide without affecting significantly the NO and NO ₂ is reduced. Furthermore, the amount of propellant used decreased due to the increase in the amount of oxygen.

As mentioned above, in this example, two existing "conventional" gun-type propellants were initially considered.
A conventional double base gun propellant and a low fragility nitramine (LOVA) gun propellant. The system works as expected with conventional double base gun propellants,
Do not pass industry standards for long-term storage (for example,
400 hours at 107 ° C). In the LOVA gun propellant,
Failure to burn the propellant at high pressures (eg, over 9,000 psi) will prove to be an inadequate system performer, which will increase design weight, cost and complexity. Normally, it is desirable that the operating pressure used for the inflator 30 be only about 4,000 psi. Under these conditions, there is no propellant suitable for this example, and a new method for forming a propellant that constitutes a new kind of propellant has been developed. That is, the ballistic properties of the double base propellant (excellent in ignition and combustion at low pressure) and the storage properties of the nitramine LOVA propellant (10
(Excellent after storage at 400C for 7 hours at 7 ° C). This type of propellant is called a hybrid propellant.

Heat-resistant gun-type propellants are different from nitrocellulose-based propellants such as HPC-96, and when used as a formation of propellant grains 90, in the case of LOVA propellants, a secondary explosive, namely nitramine, is used. (RDX). Other secondary explosives suitable for use in forming the propellant grains 90 include other nitramines, namely HMX.
(Cyclotetramethylenetetranitramine)
There are also ETN (pentaerythritol tetranitrate) and TAGN (triaminoguanidine nitrate).
Table 1 below shows the combustion characteristics of RDX, HMX and PETN secondary explosives.

[0050]

[Table 1] Usually, to combine certain ballistic properties with long-term heat resistance as desired (eg, to obtain the ballistic properties of a double-base propellant and the long-term aging properties or long-term thermal stability of a LOVA propellant). The secondary explosive is then combined with a binder system to form the propellant grains 90 ("hybrid propellant" as described above). As used herein, the term "binder system" refers to one or more compounds useful for modifying the physical, chemical, and / or ballistic properties of a propellant and added to the propellant. Useful binder systems include binder systems that incorporate a propellant additive selected from the group consisting of binders, plasticizers, stabilizers, opacifiers and these compounds.

The hybrid propellant for the propellant grains 90 in the hybrid inflator 30 exhibits excellent ballistic properties (ie, firing rate and firing temperature at relatively low operating pressures) and reasonable long-term stability (eg, One of the industry tests to evaluate long-term heat resistance is a statistically sufficient number of samples that can withstand a temperature of 107 ° C. (without ignition) for 400 hours.) Another test is an inflator 30 that can withstand a temperature of 100 ° C. for 400 hours without unacceptable performance degradation (typically set / specified by the customer). More specifically, the propellant grains 90 formed from the hybrid propellant have a particle size of about 2,000-3.8.
Combustion temperature of 00K, about 0.1-1 inch / sec
(0.25-2.5 cm / sec), about 4,000
Combustion is performed at an operating pressure (pressure in the gas generator housing 86) of 0 psi (27.6 MPa) or less. More preferably,
The propellant grains 90 formed from the hybrid propellant have about 2,
Combustion temperature of 000-3,800 K, about 0.3-0.5
It burns at a speed of inches / sec (0.76-1.26 cm / sec) and at an operating pressure of about 4,000 psi (27.6 MPa) or less.

Usually, about 50-90 is required to form a hybrid propellant.
It contains wt% secondary explosives and about 10-50 wt% binder system. More generally, the formation of these propellants requires about 60-80 wt% of a secondary explosive and about 20-80 wt.
Contains 40 wt% binder system. Preferably, the propellant formation contains about 70-80 wt% of the specific secondary explosive and about 20-30 wt% of the binder system. Other additives and unavoidable impurities may be present in the composition of these propellants in trace amounts (i.e., less than about 5 wt% composition).

Usually, the resinous binder is a propellant grain 90
A part of the binder system for the formation of a hybrid propellant for use. Ordinary solvents (ie acetone, lower alcohols, etc.)
Almost any type of binder that is soluble in can be used. However, it is generally desirable that the binder be an active compound. That is, it is desirable that the binder easily burns at the desired combustion temperature and operating pressure described above. Further, when used with a plasticizer, it is, of course, desirable that the binder be compatible with the plasticizer. Typical binders suitable for use in the propellant composition include CA (cellulose acetate), CAB (cellulose acetate butyrate), EC
(Ethyl cellulose), PVA (polyvinyl acetate), C
Examples include, but are not limited to, AP (cellulose acetate propiolate), azido polymer, polybutadiene, hydrogenated butadiene and polyurethane, and mixtures thereof. The azide polymer is at least one of a homopolymer and a copolymer having a monomer selected from the group consisting of GA (glycidyl azide) monomer, BAMO (3,3-bis (azidomethyl) oxetane) monomer, AMMO (azidomethylmethyloxetane) monomer. Including one. In addition, GAP (active glycidyl azide polymer) is used as the binder element, which burns substantially more vigorously than CA. In this case, it may be desirable to use only GAP as a binder together with the secondary explosive. However, due to the current significant cost differences between GAP and CA, the formation of hybrid propellants includes elements of both GAP and CA. Plasticizers can also be used as part of the binder system for forming the hybrid propellant for propellant grains 90. As noted above, the plasticizer should be compatible with the binder. Furthermore, it is generally desirable to use an extrudable binder system. In addition, it is desirable to use an active plasticizer for at least some secondary explosives (e.g., nitramine), i.e., a plasticizer that is capable of stable combustion at the operating temperatures and pressures described above. Useful activated plasticizers include nitrate ester plasticizers such as TMETN (trimethylolethane trinitrate), BTTN (butanetriol trinitrate), and TEGDN (triethylene glycol dinitrate), glycidyl azide plasticizers and NG (nitroglycerin). )
And other compounds such as, but not limited to, BDNPA / F (bis (2,2-dinitropropyl) acetal / formal), ATEC (acetyltriethyl citrate).

Stabilizers can also be included in the binder system for forming the hybrid propellant for the propellant grains 90. For example, certain binders and / or plasticizers, such as the nitrate ester plasticizers described above, can degrade when exposed to certain temperatures and affect ignition of the propellant grains 90 (i.e., certain temperatures). The nitrate ester plasticizer thermally decomposes to the extent that ignition occurs). Thus, stabilizers are included in the formation of the hybrid propellant and "react" with the pyrolytic binder and / or plasticizer to maintain stability (e.g.,
Reduce the risk of pre-ignition of the propellant), and improve the long-term stability of the formation of the hybrid propellant. For example, in the case of nitrates, stabilizers useful in forming the propellant include those that are activators but are nitrate receptors. Suitable stabilizers include, but are not limited to, ethyl centralialite (sym-diethyldiphenylurea), DPA (diphenylamine) and resorcinol.

One of the formations of hybrid propellants which have the desired ballistic properties and exhibit adequate long-term stability is to use the nitramine secondary explosive RDX (hexahydrotrinitrotriazine) and the binder Combination with CA (cellulose acetate), plasticizer TMETN (trimethylolethane trinitrate) and stabilizer EC (ethylcentralite). Typically, the formation of this hybrid propellant is at least about 70 watts.
t% RDX, about 5 to 15 wt% CA, about 5 to 15 w
It consists of t% TMETN and only about 2 wt% EC. These approximate relative amounts provide the desired ballistic and long-term aging properties for hybrid propellants. However, if the propellant grains 90 are formed by extrusion from this formation, it will be understood that it is necessary to refine relative amounts within the above numerical ranges.

Also, at least about 70% by weight of the propellant
RDX (hexahydrotrinitrotriazine),
About 5 to about 15% by weight of CA (cellulose acetate)
And about 5 to about 15% by weight of one of GAP (glycidyl azide polymer) and ATEC (acetylethyl citrate). Generally, when a mixture of a binder, a plasticizer and a stabilizer is used as a binder system, the mixing ratio of each agent is about 5% by weight.
To 30% by weight, 0% to 20% by weight and 0% by weight
To 5% by weight.

Another hybrid propellant having the desired impact properties and suitable long term stability is the nitramine secondary explosive RD
X and a binder system comprising CA and GAP (glycidyl azide polymer) as binders and a suitable plasticizer (eg, GAP plasticizer, TMETN, ATEC and combinations thereof). Generally, the hybrid propellant will be at least about 70 wt%, typically about 70-80 wt%.
RDX, about 5 to 15 wt% CA, and about 5 to 15 w
It has t% GAP and about 5-15 wt% plasticizer. These relative amounts provide the desired impact and long-term aging properties for the hybrid propellant.
s). However, if the propellant grains 90 are formed from this hybrid propellant by extrusion, it may be necessary to adjust the relative amounts within the above ranges. For hybrid propellants including double base propellants and LOVA propellants of the large amounts of carbon monoxide and hydrogen are formed during the combustion (e.g., 35% CO and 19% H ₂ is formed during combustion) . The formation of carbon monoxide and hydrogen gas by combustion of inflator propellants is not generally acceptable in inflatable safety systems for motor vehicles. But,
When these types of hybrid propellants are used in the hybrid inflator 30, nearly all (eg, 95%) of carbon monoxide and hydrogen is converted to harmless carbon dioxide and water vapor during or as part of the post-combustion reaction. Pressurized medium 3
6 contains oxygen. The use of hyperbaric oxygen is particularly desirable because the use of hyperbaric oxygen eliminates the need to include an oxygen source (eg, potassium perchlorate) in the hybrid propellant.
In addition, the exothermic reaction that occurs between the combustion gas formed from the propellant and the high pressure oxygen increases the propellant's heating value, thereby minimizing the amount of propellant needed to inflate the air / safety bag. The exothermic reaction is particularly preferable in order to minimize the reaction.

The hybrid propellant is formed as a propellant grain 90 and, when inserted into the hybrid inflator 30, is available in the specific amounts indicated above for the gun-type propellant and includes the propellant grain 90. And the relative features of the pressurized medium 36 may be included in particular. Further, the relative amounts of oxygen and one inert gas used in pressurized medium 36 can be used in the hybrid propellants disclosed herein.

The following examples show the properties associated with hybrid propellants, including secondary explosives and binder systems. As described above, “Wt%” indicates percent by weight. Example 4: at least about 70 wt% RDX (hexahydrotrinitrotriazine), about 5-15 wt% CA
(Cellulose acetate), about 5 to 15 wt% TME
TN (trimethylolethane trinitrate) and about 2
A hybrid propellant composition containing up to wt% ethyl centralialite was prepared, and the propellant composition was about 1.7132 g.
/ Cc formed as cylindrical grains having an average density of / cc. Insert a 10 g sample into a bomb chamber with thick walls,
And exploded into the tank. The sample is 4,000
It has a combustion temperature of about 2,578 K at psi (27.6 MPa) and has acceptable impact properties (i.e., 0.
47 inches / second (1.18 cm / second)). The performance curves for this generally corresponded approximately with the curves shown in FIGS. The gas formed had about 36% carbon monoxide, about 24% nitrogen, about 19% hydrogen, about 16% water vapor and about 5% carbon dioxide. An evaluation of the long-term thermal stability of the hybrid propellant composition was performed and the results confirmed that the long-term thermal stability of the composition was within acceptable limits (eg, propellant over 400 hours). Exposure to a temperature of 107 ° C. did not ignite the propellant, and the propellant was mixed in a hybrid inflator.
Exposure to a temperature of 107 ° C. for 400 hours did not ignite the propellant. Thereafter, the propellant was activated, but the performance of the inflator was substantially unaffected by the heat treatment).

Example 5: RDX of at least about 70 wt%
(Hexahydrotrinitrotriazine), about 5 to 15
wt% cellulose acetate, and about 5-15 wt%
A hybrid propellant composition comprising GAP (glycidyl azide polymer) was prepared, wherein the propellant composition was about 1.6885.
Formed as cylindrical grains having an average density of 7 g / cc. A 10 g sample was inserted into a bomb chamber with a thick wall and exploded into the tank. The sample is 4,000
About 2,357 ° K at 0 psi (27.6 MPa)
Having a combustion temperature of and acceptable impact properties (ie,
0.48 inches / sec (1.18 cm / sec)).
The performance curves for this generally corresponded approximately with the curves shown in FIGS. The gas formed is about 37% carbon monoxide, about 25% hydrogen, about 25% nitrogen, about 10%
Water vapor and about 3% carbon dioxide. An evaluation of the long-term thermal stability of the hybrid propellant composition was performed and the results confirmed that the long-term thermal stability of the composition was within acceptable limits (eg, propellant over 400 hours). The propellant did not ignite when exposed to a temperature of 107 ° C. The propellant did not ignite when exposed to a temperature of 107 ° C. for 400 hours in a hybrid inflator. Although the agent was activated, the performance of the inflator was substantially unaffected by the heat treatment).

[0061] Another propellant used in one or another embodiment of the present invention is hexogen (RD).
X) 1 to 99 parts by weight and Octogen (HMX) 99 to
The binder is contained in an amount of 5 to 50 parts by weight based on 1 part by weight and further 100 parts by weight of RDX and HMX in total. Preferably, 80 to 95 parts by weight of hexogen (RDX), 20 to 5 parts by weight of octogen (HMX), and further R
The binder is contained in an amount of 5 to 50 parts by weight based on 100 parts by weight of DX and HMX in total.

The above propellants are used in the hybrid inflators described herein. A hybrid inflator generally includes a pressurized gas chamber containing a pressurized gas, a gas generating chamber containing a propellant, an ignition assembly, a rupturable plate, and the like. The pressurized gas consists essentially of an inert fluid and oxygen. The propellant is ignited and burned by the ignition assembly during a vehicle collision to produce gaseous, oxygen-reactive combustion products, namely, carbon monoxide and hydrogen.
Carbon monoxide and hydrogen react with oxygen in the pressurized gas to generate carbon dioxide and water vapor, while increasing the pressure in the gas chamber. Then, the rupturable plate is broken, and carbon dioxide, water vapor, and an inert fluid are supplied to the airbag 18 (FIG. 1) from the outlet of the inflator, and the airbag 18
(FIG. 1) expands.

The propellant is hexogen (RDX),
It is composed of Octogen (HMX) and a binder. The ratio of RDX, HMX and the binder is as follows: RDX1 to 99 parts by weight, HMX99
バ イ ン ダ ー 1 part by weight, preferably 80 to 95 parts by weight of RDX, 20 to 5 parts by weight of HMX, and 5 to 50 parts by weight of the binder to 100 parts by weight of RDX and HMX in total.

The binder that can be used in the present invention is not particularly limited, but includes polyurethanes (PU), ethyl cellulose (EC), cellulose acetate butyrate (CA).
B), Cellulose acetate propionate (CAP)
Cellulose derivatives such as hydroxyterminated polybutadiene (HTPB); glycidyl acid polymers such as glycidyl nitrate polymer (polygulin);
Includes azide polymers such as glycidyl azide polymer (GAP), and polymers of 3-nitrate methyl-3-methyloxymethane (Polynimo). Among these, cellulose acetate butyrate (CAB) and / or
Alternatively, glycidyl azide polymer (GAP) is desirable.

The propellant of the present invention may further contain a plasticizer, a stabilizer, and an additive selected from the group consisting of these compounds.
(Trimethylolethane trinitrate), BTTN
(Butanetriol trinitrate), TEGDN (triethylene glycol dinitrate), glycidyl azide, NG (nitroglycerin), BDNPA / F (bis (2,2-dinitropropyl) acetal / formal) and ATEC (acetyl triethyl citrate) It is preferably selected from the group consisting of

Further, as a stabilizer usable in the above-mentioned propellant, for example, ethyl centralia, diphenylamine, resorcinol, acardite, amyl alcohol, urea, petroleum jelly and the like can be used.

The amount of the plasticizer added was RDX, HMX,
And 0 to 30 with respect to a total of 100 parts by weight of the binder.
Parts by weight are preferred. The amount of the stabilizer added is RDX, H
For a total of 100 parts by weight of MX and binder, 0
-5 parts by weight is preferred.

The form of the propellant of the present invention may be any form such as powder, granule and pellet, but it is preferable to use the form of pellet. The following are examples of some compositions suitable for use in the present invention. Example 6: A substance having the following composition is mixed into pellets,
It was loaded into a hybrid inflator composed of a pressurized gas chamber, a gas generation chamber, an ignition assembly, and a rupturable plate. Then, the hybrid inflator was operated. As a result, no smoke composed of KCl was generated.

Hexogen (RDX) 68 parts by weight Octogen (HMX) 8 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight In addition, binder (CAB, GAP) based on 100 parts by weight of RDX and HMX Is about 32 parts by weight. Example 7: A substance having the following composition is mixed into pellets,
The same hybrid inflator as in Example 6 was loaded and the hybrid inflator was operated. As a result, no smoke was generated.

Hexogen (RDX) 72 parts by weight Octogen (HMX) 4 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight In addition, binders (CAB and GAP) based on 100 parts by weight of RDX and HMX Is about 32 parts by weight. Example 8: A substance having the following composition is mixed into pellets,
The same hybrid inflator as in Example 6 was loaded and the hybrid inflator was operated. As a result, no smoke was generated.

Hexogen (RDX) 64 parts by weight Octogen (HMX) 12 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight In addition, binder (CAB, GAP) based on RDX and HMX 100 parts by weight Is about 32 parts by weight. Example 9: A substance having the following composition is mixed into pellets,
The same hybrid inflator as in Example 6 was loaded and the hybrid inflator was operated. As a result, no smoke was generated.

Hexogen (RDX) 75 parts by weight Octogen (HMX) 1 part by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Binders (CAB, GAP) based on 100 parts by weight of RDX and HMX Is about 32 parts by weight. Example 10: A substance having the following composition was mixed into pellets, loaded into the same hybrid inflator as in Example 6, and the hybrid inflator was operated. As a result, no smoke was generated.

Hexogen (RDX) 1 part by weight Octogen (HMX) 75 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight In addition, binder (CAB, GAP) based on 100 parts by weight of RDX and HMX Is about 32 parts by weight. Example 11: A substance having the following composition was formed into pellets, loaded into the same hybrid inflator as in Example 6, and the hybrid inflator was operated. As a result, no smoke was generated.

Hexogen (RDX) 38 parts by weight Octogen (HMX) 38 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Binders (CAB, GAP) based on 100 parts by weight of RDX and HMX Is about 32 parts by weight. Example 12: A substance having the following composition was pelletized, charged in the same hybrid inflator as in Example 6, and the hybrid inflator was operated. As a result, no smoke was generated.

Hexogen (RDX) 68 parts by weight Octogen (HMX) 8 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Ethylcentralite 2 parts by weight RDX and HMX 100 parts by weight The content of the binder (CAB, GAP) is about 32 parts by weight. Example 13: A substance having the following composition was mixed into pellets, charged into the same hybrid inflator as in Example 6, and the hybrid inflator was operated. As a result, no smoke was generated.

Hexogen (RDX) 68 parts by weight Octogen (HMX) 8 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Trimethylolethane trinitrate 20 parts by weight (TMETN) RDX And the content of the binder (CAB, GAP) per 100 parts by weight of HMX is about 32 parts by weight. Example 14: A substance having the following composition was formed into pellets, loaded into a hybrid inflator similar to that in Example 6, and the hybrid inflator was operated. As a result, no smoke was generated.

Hexogen (RDX) 68 parts by weight Octogen (HMX) 8 parts by weight Cellulose acetate butyrate (CAB) 12 parts by weight Glycidyl azide polymer (GAP) 12 parts by weight Ethylcentralite 2 parts by weight Trimethylolethane trinitrate 20 parts by weight (TMETN) The content of the binder (CAB, GAP) is about 32 parts by weight based on 100 parts by weight of RDX and HMX.

FIGS. 5-7 show another embodiment of a hybrid inflator that can be used in the inflatable safety system 10 shown in FIG. As shown mainly in FIG. 5, the hybrid inflator 2
02 has a generally cylindrical gas generator 208 and a generally cylindrical high pressure gas housing 204, the high pressure gas housing 204 (third chamber) being the same around the gas generator 208. It is arranged to have the same central axis as the gas generator 208. Generally, the high pressure gas housing 204 has a suitable pressurized medium and the gas generator 208 has a suitable propellant grain 258. The main advantage of the inflator 202 is that its design is such that the second closing disc (primary closing disc) 290 (the second closing disc 290 is
This is to allow rapid pressurization in the area adjacent to the flow blocking (see FIG. 1) between the safety bag 18 (see FIG. 1), whereby the fluid pressure created by the second closing disc 290 to close the disc 290
Acts directly on. Another important advantage with respect to the design of the inflator 202 is that it provides or allows for sufficient mixing between the propellant gas and pressurized medium formed by ignition and combustion of the propellant grains 258. As a result, the inflator 202 uses at least one of the aforementioned gun-type propellant composition and the hybrid propellant composition as a composite pressurized medium (eg, one component is oxygen and another component is at least one non- It is particularly suitable for use with a complex pressurized medium which is an active gas. That is, the design of the inflator 202 is such that the gas formed by the ignition of the propellant gas and the propellant grains 258 (eg, the ignition / booster described in detail below) may facilitate the operation of the inflatable safety system 10 (see FIG. 1). At least one of the gases formed by the combustion of the agent 240) is effectively combusted with the pressurized medium. This second combustion increases the rapid inflation capability of the inflator 202 to initiate gas flow to the air / safety bag (see FIG. 1).

The gas generator 208 has a cylindrical gas generator housing 212, and the gas generator housing 212 is the first housing 21 in this embodiment.
6 and is coupled to the second housing 278 along the axial direction. Gas generator housing 2
12 contains a large amount of pressurized medium in its entirety in a static state, so that one end of the first housing 216 has an initiator adapter 224 to form a hermetic seal.
(For example, connection by welding at the welding portion 248). The initiator adapter 224 includes a suitable initiator 228 (eg, an electric igniter tube or other suitable explosive device).
Is used to perform ignition on the propellant grains 258. In addition, the initiator 228 is engageable on its outer circumference along the inner circumference of the O-ring 232 to form a suitable seal. In order to separate the initiator 228 from the pressurized medium contained within the gas generator 208, the first closure disk (sub-closure disk) 236 is
First housing 2 to form a hermetic seal via
It is appropriately fixed between the end of the adapter 16 and the end of the initiator adapter 224.

The first housing 216 of the gas generator housing 212 defines a first chamber 254. The first chamber 254 is disposed adjacent to and axially aligned with the initiator 228. First chamber 25 of gas generator housing 212
4 mainly comprises propellant grains 258 which, when ignited, cause the air / safety bag 18
Propelling gas is formed to increase the flow of gas to (see FIG. 1). As a result, the first chamber 254 can be characterized as a propellant or combustion chamber. Propellant grain 2
To assist ignition of 58, a suitable ignition / booster agent 240 (e.g., RDX / aluminum booster agent containing 89 wt% RDX and 11 wt% aluminum powder, or 0 of the same RDX / aluminum booster agent) Between 0.5 and 5.0 wt% RDX and 0.5 to 5.0 wt% hydroxypropylcellulose can be used as a booster agent) between initiator 228 and propellant grains 258.
It can be arranged at a position matching the discharge from the initiator 228. As described in more detail below, the gas product formed by the ignition of the igniter / booster agent 240 can be chemically reacted with the pressurized medium to further enhance the characteristics of the onset of flow by rapid inflation of the inflator 202. It is. A suitable booster cup 244 or the like retains the igniter / booster agent 240 (typically in the form of a powder or slurry dry body) therein, and the end of the initiator adapter 224 and the first end. (Eg, held between the adapter 224 and the housing 216 via a weld 248). The first chamber 254 has a screen 266 or the like to discharge a propellant gas into the second chamber 324 as described above, while retaining particulate matter of a particular size therein. I can do it. In addition, the inflator 2
02 has a capacity of the high-pressure gas housing 204 in the second chamber 3.
24 is set larger than the capacity.

The first chamber 254 is a high pressure gas housing 2
04 is generally connected to at least one bleed orifice or bleed port 262 (two bleed ports are formed in this embodiment). As a result, the first chamber 254 contains a large amount of pressurized medium in a static state.
The bleed port 262 extends radially (ie, the bleed port 262 has its origin on the central axis 220 and extends along a radius extending in a direction perpendicular to the central axis 220). ). In order to properly adjust the performance of the inflator 202, the use of the bleed port 262 and the bleed port 262
Size and / or quantity can be selected.

By forming at least one bleed port 262, a specific amount of the propellant gas flow formed by the ignition of the propellant 258 is controlled by the high pressure gas housing 2.
Guided inside 04. Propellants of the type described above (e.g., gun-type propellants, hybrid propellants) and pressurized media (e.g.,
If a mixture of oxygen and an inert fluid (including at least one inert gas) is used, a second combustion, i.e., a further combustion of the propellant gas, occurs in the high-pressure gas housing 204. Part of the propellant gas is transferred to the first chamber 254.
Guiding into the high-pressure gas housing 204 from
It can be used to achieve a desired output or discharge to the air / safety bag 18, ie to achieve a desired inflation rate of the air / safety bag 18. As will be described in more detail below, the propellant gas is supplied to the high pressure gas housing 20 at a rate that maintains a substantially constant flow of gas from the high pressure gas housing 204 to the second chamber 324 for a sufficient period of time.
4 is preferably provided. Generally, less than half of the propellant gas formed to achieve the desired result (e.g., no more than about 40% of the propellant gas, more typically no more than about 30% of the propellant gas). Is guided into the housing for high pressure gas 204 during operation.
It needs to flow in.

The pressure increase in the high pressure gas housing 204 after ignition of the propellant grains 258, even with the bleed ports 262, is significantly less than that found in many commercial hybrid inflators. That is, the significant pressure build-up typically associated with ignition of propellant grains 258 is substantially confined within gas generator 208. As a result, the strength condition of the high-pressure gas housing 204 can be reduced. This allows at least one of reducing the wall thickness of the high-pressure gas housing 204 and / or using a lightweight material for the high-pressure gas housing 204. Both of these reduce the weight of the inflator 202.

The main flow of propellant gas formed in the first chamber 254 (eg, at least about 50%, and typically at least about 70% of the total flow of propellant gas), It is guided into a second chamber 324 (referred to as an "afterburner" for reasons detailed below) formed by the second housing 278. At least one afterburner nozzle or aspirator 274 (first through hole) is provided in the first chamber 25.
Gas flow from 4 into second chamber 324 (mainly propellant gas)
To thereby form the desired communication. The afterburner nozzle 274 is connected to the first housing 21.
Prior to properly connecting 6 to second housing 278 (eg, by welding at weld 250), shoulder 2 formed inside first housing 216
70 and the first housing 216
It is arranged inside.

In this embodiment, the gas generator housing 21
One end of the second second housing 278 is engaged with the inner surface of an afterburner adapter 282 having at least one gas generator outlet 286 therein. O-ring 328 is located between second housing 278 and adapter 282 to provide a suitable seal. Adapter 282 for afterburner is boss 294
(For example, the welded portion 308).
The boss 294 is fixed to the high-pressure gas housing 204 (for example, fixing by welding at the welding portion 312). Second room 324
Has a large amount of pressurized medium in the static state,
These two fixings are preferably performed so as to form a hermetic seal. In order to properly hold the pressurized medium in the inflator 202 until the desired time is reached, the second closing disc 290 is connected to the afterburner adapter 2.
It is located between the end of 82 and the boss 294 and is held by the weld 308.

The communication between the first chamber 254 and the second chamber 324 provides at least a portion of the propellant gas formed by the combustion of the propellant grains 258 and the gas formed by the ignition of the igniter / booster agent 240. Are guided into a second chamber (afterburner chamber) 324. Second chamber 324 controlled based on the method detailed below
Due to the sudden pressure increase in the second closure disc 290
Is opened at the appropriate time and the gas flow from the inflator 202 is directed to the diffuser 298 and then into the air / safety bag 18 (see FIG. 1). Diffuser 298 includes a plurality of diffuser ports 300 to provide less disruptive output to air / safety bag 18 (see FIG. 1). The retention of certain particulate matter in the inflator 202 and the mixing or reaction of the propellant gas and pressurized medium before the propellant gas and pressurized medium pass into the air / safety bag 18 (see FIG. 1). The diffuser 298 may include a diffuser screen 304 to achieve at least one of further facilitation.

Further, the second chamber 324 communicates with the high-pressure gas housing 204. At least one, and preferably a plurality, of gas generator inlets 316 form a communication between the high pressure gas housing 204 and the second chamber 324. As a result, the pressurized medium in the high-pressure gas housing 204 can flow into the second chamber 324 at an appropriate time.
That is, in a specific application, the flow direction of this specific gas flow can be controlled. In particular, valve 320 can be located adjacent to at least one, and preferably all, gas generator inlets 316. In the static state, the valve 320
Need not actually separate the high pressure gas housing 204 from the second chamber 324 in this region. In fact, a large amount of pressurized medium is preferably retained in the second chamber 324 in a static state. This allows a connection without hermeticity to be used for such a supply. One configuration of the valve 320 that does not separate the second chamber 324 from the high pressure gas housing 204 above the gas generator inlet 316 includes a filler material comprised of a generally cylindrical roll (eg, 300 series stainless steel). And has a thickness of 0.002 inches (approx.
m) thing). A cantilever connection can be used between the valve 320 and the inner wall of the second housing 278. At this time, the rear part of the valve 320 (that is, the part sufficiently separated from the inlet 316) is connected to the second housing 278, and the front part and the intermediate part of the valve 320 are not connected to the other. As a result, the valve 320 can move or deflect freely.

From the above, the high pressure gas housing 2
It can be seen that the pressures spreading inside each of the housing 04 and the gas generator housing 212 are substantially equal in the static state. However, dynamic conditions or propellant grains 25
After the ignition of 8, the pressure in each chamber of the inflator 202 is different from each other to achieve the desired performance. When the ignition of the propellant grains 258 is performed, the formed propellant gas begins to flow into at least the second chamber 324 to increase the pressure in the second chamber 324. With the inflator 202 having at least one bleed port 262, a portion of the propellant gas is
4 and the high pressure gas housing 20
4 results in a small pressure increase. Second room 32
The pressure increase rate in the housing 4 for high pressure gas
Preferably, it is even faster than the pressure increase rate in the pressure 4. The difference between the pressure increasing rates is generated based on the flow of the propellant gas into each of the second chamber 324 and the high-pressure gas housing 204 and the relative volume difference therebetween. This pressure differential causes valve 320 to be pressed against the inner wall of gas generator housing 212, more specifically, the portion of second housing 278 that is aligned with valve 320. As a result, the high-pressure gas housing 204
The gas generator inlet 316 is separated from the second chamber 324 by being shut off by the valve 320. The cantilever connection of the valve 320 allows movement of the valve 320. When the pressure in the second chamber 324 reaches a predetermined pressure value, the fluid pressure acting directly on the second closing disc 290 will open, rupture or break it. As a result, the opening of disk 290 creates a gas flow from gas generator 208 to diffuser 298 and air / safety bag 18 (see FIG. 1).

The valve 320 may provide air /
Enables the timely initiation of gas flow into the safety bag 18 (see FIG. 1). In certain designs, the use of the valve 320 allows the second closure disc 29
The second chamber 324 can be rapidly pressurized at such a speed that the zero can be opened in a timely manner. If the inflator 202 does not have the valve 320, the propellant gas flows from the second chamber 324 into the high-pressure gas housing 204. In this case, it may take a longer time for the internal pressure of the second chamber 324 to reach a pressure value that can rupture the second closing disk 290. However, the use of the second chamber 324 provides a smaller pressurized chamber, which allows the air / safety bag 18
The time required to start the flow of gas to (see FIG. 1) is reduced. In certain designs, as described in detail below, the volume of the second chamber 324 is sufficiently small and the propellant and pressurized medium are adjusted to achieve satisfactory operation without the use of the valve 320. At least one of the selections can be performed (e.g., formed by combustion of at least one of propellant grains 258 and / or igniter / booster agent 240 to perform rapid pressurization in second chamber 324). Utilizing the combustion of gas that has been used).

The valve 320 maintains its position after the second closure disk 290 has been opened to create a flow of gas to the air / safety bag 18 (see FIG. 1), and thereby allows the gas to flow. The generator inlet 316 is shut off for a specified time. However, if a particular pressure differential is created between the high pressure gas housing 204 and the second chamber 324, the valve 320
Is moved by the pressing force caused by this pressure difference so as to expose. When the valve 320 is formed as described above,
The free end of the valve 320 moves radially inward toward the central axis 220 or indents the valve 320 at least in a region radially aligned with the gas generator inlet 316. This allows the desired gas flow through the gas generator inlet 316.
However, valve 320 is retained by its connection to second housing 278. Gas generator inlet 316
Is exposed, the flow of gas from the high-pressure gas housing 204 into the second chamber 324 is started. The valve 320 is movable from a first position to a second position. That is, the valve 320 is positioned in the first position in use to substantially block the flow. When the pressure in the high pressure gas housing 204 exceeds the pressure in the gas generator housing 212 by a predetermined amount, the valve 320 moves to a second position to allow the flow, and the second position has a radius. It is located inside the first position along the direction.

The second chamber 3 after the second closing disk 290 is broken by the rapid pressurization of the second chamber 324
The primary function of 24 is to provide or allow for effective mixing of the propellant gas and pressurized medium before the propellant gas and pressurized medium are expelled into air / safety bag 18 (see FIG. 1). That is. Propellant compositions of the type described above (e.g.,
When a gun-type propellant, a hybrid propellant) and a pressurized medium of the type described above (for example, a mixture of an inert fluid and oxygen typified by one containing at least one inert gas), this mixture is used. Promotes to provide the aforementioned effects, including, for example, reducing toxicity and reducing the total amount of propellant used in the inflator 202 by further burning and increasing the expansion capacity resulting from the burning. This results in further combustion of the gas. In this case, the second chamber 324
Is further characterized as an afterburner. Preferably, at least about 99% of the total combustion of the propellant gas and the gas formed by the ignition of the ignition / booster agent 240 occurs, and more preferably about 100% of such combustion occurs in the inflator 202. This is air / safety bag 1
8 (see FIG. 1) to reduce the risk of damage.

In order to achieve the full effect of this second combustion, the second chamber 324 may be provided with a gas formed by either its length or the formation of turbulence, as described in more detail below. And a sufficient mixing of the pressurized medium must be provided or tolerated. In the embodiment shown in FIG. 5, the afterburner nozzle 274 and the gas generator outlet 28 out of all the gas generator inlets 316 are used in the driver side use.
6 is at least 15 mm away from the gas generator outlet 286. This interval can be set within a range of 4 mm to 80 mm. The increase in the length of the second chamber 324 causes the high-pressure gas
A sufficient amount of pressurized medium, which reacts with the propellant gas formed before the flow of gas from the gas into the second chamber 324 begins, can be contained in the second chamber 324 in a static state. Become. That is, a sufficient amount of the pressurized medium that reacts with the propellant gas until the flow of the pressurized medium from the high-pressure gas housing 204 to the second chamber 324 is started by the movement of the valve 320 is increased. Is preferably included from the beginning.

To achieve the effect of the "long" second chamber 324, the gas generator inlet 316 is preferably formed at a position sufficiently spaced from the gas generator outlet 286. Preferably, the most mesial portion or the foremost portion of all gas generator inlets 316 (each of the gas generator inlets 316) facilitates further mixing of the propellant gas and the pressurized medium. (Defined by the center line) is positioned along the length of the second housing 278 in alignment with the end of the afterburner nozzle 274, and the portion located further forward is the afterburner as shown in the figure. -It is preferable that the nozzle 274 be disposed further rearward (that is, in a direction approaching the initiator 228).

Although the dimensions of any design of the inflator 202 can be changed, as shown in Table 2, particularly, the preferable range of the capacity of the inflator housing 204 depends on the use of the inflator. For example, the capacity of the inflator housing 204 ranges from about 150 cm ³ to about 450 c.
m ³ , the capacity of the first chamber 254 is from about 10 cm ³ to about 40 c
m ³ , and the volume of the second chamber 324 is from about 1 cm ³ to about 50
cm ³ .

In order to show the principle of the present invention, its dimensions in one embodiment are exemplified below. 1) The diameter of the high-pressure gas housing 204 is about 59 mm. 2) The length of the high-pressure gas housing 204 is about 200 mm.
3) The high-pressure gas housing 204 is formed from a mild steel tube and its wall has a thickness of about 2.5 mm.
4) The internal volume of the high-pressure gas housing 204 (the volume of the portion of the interior of the high-pressure gas housing 204 that includes the pressurized medium, including the volume of the gas generator 208 located at the center thereof. No) is about 375cc.
5) The diameter of the first housing 216 of the gas generator housing 212 is about 20 mm. 6) First room 2
The length of 54 is about 55 mm. 7) The first housing 216 is made of mild steel and its wall is about 1.5 mm
Thickness. 8) Gas generator housing 212
The inner volume of the first chamber 254 is about 11 cc. 9) The diameter of the second housing 278 of the gas generator housing 212 is about 17 mm. 10) The length of the second chamber 324 is about 90 mm. 11) The second housing 278 is made of mild steel and its wall has a thickness of about 1.25 mm. 12) The interior volume of the second chamber 324 of the gas generator housing 212 is about 14 cc. 13) The inflator 202 is about 3 mm
Are provided. 1
4) The inner diameter of the afterburner nozzle 274 is about 2.5
mm. 15) Outlet 286 for gas generator is about 10m
m. 16) All gas generator inlets 316 are located about 76 mm away from gas generator outlets 286. 17) The nozzle 274 is located at a distance of about 75 mm from the gas generator outlet 286. 18) The internal volume of the diffuser 298 is about 4
cc. 19) The inflator 202 has twelve diffuser ports 300. 20) The total weight of the propellant grains is about 9 g,
Includes a composition of the type described above with DX, CA, TMETN and a stabilizer. 21) The static pressure in the inflator 202 is about 20.7 MPa, and the inflator 202 contains about 140 g of a pressurized medium. 85 of the same pressurized medium
Percent (mol percent) is argon and 15% (mol percent) is oxygen. 22) Inflator 202
Has a total weight of about 1,200 g.

When helium is included in the pressurized medium to detect gas leakage, its composition is on a molar basis,
Preferably, oxygen is about 8% to about 30%, argon is about 60% to about 91%, and helium is about 0.5% to about 10%.

The operation of the inflator 202 is shown in FIGS.
D and FIGS. 7A to 7D. As shown in FIGS. 6A and 7A, the second closure disk 290 is intact in the static state, and the valve 320 does not need to separate the high pressure gas housing 204 from the second chamber 324. Initiator 228 is activated when a suitable signal indicating that deployment of air / safety bag 18 (see FIG. 1) is required is detected by detector / sensor 14 (see FIG. 1). Activation of the initiator 228 ruptures the first closure disk 236 and ignites the igniter / booster 240, which ignites the propellant grains 258. The combustion of the propellant grains 258 forms a propellant gas in the first chamber 254. The propellant gas is supplied to the second chamber 3 of the gas generator housing 212.
24 and into the high-pressure gas housing 204. The presence of the hot propellant gas in the first chamber 254 and the flow of the hot propellant gas into the second chamber 324 and the high-pressure gas housing 204 allows for these "vessels".
A corresponding increase in pressure takes place within.

To break the second closure disk 290 at the appropriate time, thereby initiating the flow of gas into the air / safety bag 18 (see FIG. 1), the second chamber 32
4 is designed to be even faster than in the high pressure gas housing 204 by guiding the hot propellant gas into it. As shown in FIGS. 6B and 7B, this pressure differential causes the valve 320 to move from the second housing 324 to separate the high pressure gas housing 204 from the second chamber 324 to affect the rapid pressurization of the second chamber 324. 278 toward the inner wall. Since the supply of the pressurized medium that reacts with the propellant gas is stopped, the total amount of the pressurized medium present in the second chamber 324 in the static state becomes smaller between the high-pressure gas housing 204 and the second chamber 324. It must be of sufficient quantity to react with the propellant gas guided into it before forming direct communication.

As shown in FIG. 6C, when the pressure in the second chamber 324 reaches a predetermined value, the fluid pressure acting directly on the second closing disk 290 breaks the second closing disk 290. , Whereby the gas generator outlet 286
A gas flow is formed through the diffuser 298 and the air / safety bag (see FIG. 1). However, as shown in FIGS. 6C and 7C, the valve 320 blocks gas flow directly from the high pressure gas housing 204 to the second chamber 324 by closing the gas generator inlet 316. As shown in FIGS. 6D and 7D, after a certain pressure difference is formed between the high-pressure gas housing 204 and the second chamber 324, the pressure difference is transferred from the high-pressure gas housing 204 to the second chamber 324. The valve 320 is spaced from the gas generator inlet 316 to form a pressurized medium flow. For example, the structure of the valve 320 shown here (eg, a cylindrical roll of metal foil) may cause the valve 320 to form when the specified pressure differential is created in a region adjacent or aligned with the gas generator inlet 316. The front of the indents or moves inward along the radial direction. However, the rear of valve 320 maintains a connection with second housing 278.

In view of the foregoing, the design of the inflator 202 is based on a system including the propellant (eg, a gun-type propellant, a hybrid propellant) and a pressurized medium (eg, a mixture of oxygen and at least one inert gas). It can be seen that the method is particularly suitable for improving the performance of. For example, if the aforementioned propellant and pressurized medium were used, the second chamber 3
In 24, a second combustion of the propellant gas and the pressurized medium occurs. This additional combustion causes the gas to expand further. Further expansion of the gas can reduce the amount of propellant required. This reduction in the amount of propellant allows the weight of the inflator 202 to be reduced. Furthermore, this second combustion reduces the toxicity of the propellant gas. The length of the second chamber 324 is long, in particular, the afterburner nozzle 274 and the gas generator outlet 286 of the gas generator inlet 316.
And the gas generator outlet 286, the distance between the gas generator outlet 286 and the gas generator outlet 286 is sufficient to allow a second combustion to occur before the gas flows out to the air / safety bag 18 (see FIG. 1). Time is gained.

As described above, in certain designs, the inflator 202 may be configured as described above, except for the use of the valve 320. This can be achieved by using a propellant of the type described above and a pressurized medium. The propellant is oxidized under pressure in the second chamber 324 (eg,
A propellant gas that can be further combusted is formed by mixing with an inert fluid, such as one containing one or more inert gases, and an oxidizing pressurized medium composed of a composite of oxygen. In this case, the combustion of the propellant gas occurring in the second chamber 324 and the second combustion of the gas formed by the ignition of the igniter / booster agent 240 is such that the pressure increase or pressure is sufficient such that the valve 320 is not required. Brings increased speed. For example, after activating the inflator 202, the second chamber 32
The second combustion occurring within 4 accounts for at least about 30% of the pressure increase or rate of pressure increase, up to about 50%.
%. In this case, the second chamber 32
The initiation of flow by rapid pressurization can be realized using the chemical reaction in 4, which reduces the need for valve 320.

FIGS. 8-11 show another embodiment of a hybrid inflator that can be used in the inflatable safety system 10 shown in FIG. Although the function or operation of the inflator 350 is similar to that of the inflator 202, the inflator 350 is formed particularly adapted for use on the driver's side. Inflator 350 may include a propellant of the type described above (e.g., gun-type propellant, hybrid propellant) and a composite pressurized medium (e.g., an inert fluid typified by one containing at least one inert gas) and oxygen. The use of a mixture may improve the performance of the inflatable safety system 10.

As shown principally in FIG. 8, a hybrid inflator 350 generally has two main components to achieve a hermetic seal, the two main components being a gas generator 362 and a diffuser. Central housing 3 including 458
58 and a high pressure gas housing 354 mounted along the outer periphery of the central housing 358 (eg, the high pressure gas housing 354 can be coupled to the central housing 358 by welding at welds 442, 450). . The high-pressure gas housing 354 has a donut shape and has a pressurized medium therein. The main advantage of the inflator 350 is that the inflator 350 can open the second
Adjacent to a second closure disk 428 (the second closure disk 428 separates the gas flow between the inflator 350 and the air / safety bag 18 (see FIG. 1)) to exert a fluid pressure directly on 8 This is a point that acts on the rapid pressurization in the region that has been set. Further, as will be described in greater detail below, another advantage of the inflator 350 is that it provides a substantial pressure increase primarily within the gas generator 362 associated with propellant activation. As a result, the wall thickness of the high-pressure gas housing 354 becomes thinner than that of the conventional hybrid inflator (that is, the ratio of the pressure applied to the high-pressure gas housing 354 is reduced as compared with the conventional hybrid inflator). The weight of 350 can be reduced.

[0104] The central housing 358 is
The central housing 358 is disposed around a central axis 352 extending in the length direction of the gas generator 362.
It has a diffuser 458 aligned with the gas generator 362 along its length direction and spaced from the gas generator 362. Gas generator 362 and diffuser 458 are at least partially formed by central housing 358. For example, the gas generator 3
62 is a substantially cylindrical gas generator housing 366
The gas generator housing 366 is a part of the central housing 358, the ignition assembly holder 3
70, a dome-shaped septum 390, and a gas generator end cap assembly 420. In particular, since the gas generator housing 366 has a large amount of pressurized medium in a static state, the ignition assembly holder 370 is located below the central housing 358 and the high pressure gas housing to form a corresponding hermetic seal. 354 are properly coupled to both (eg,
Connection by welding at the welding portion 442). Ignition assembly holder 370 is provided with a suitable ignition assembly 374
(Eg, an electric igniter tube or other suitable explosive device) and an O-ring 372 may be used to form a seal. To form a hermetic seal for separating the ignition assembly 374 from the pressurized medium in the gas generator 362, a first closing disc (secondary closing disc) 3 is formed.
Reference numeral 78 is suitably connected to the end of the ignition assembly holder 370 (for example, connection by welding at the welding portion 446). In this embodiment, the first closure disk 378 is welded between the end of the main housing 382 of the ignition assembly holder 370 and the end cap 386 of the ignition assembly holder 370 of the ignition assembly holder 370. 446.

The partition wall 390 is a gas generator housing 366.
Into a first chamber 394 and a second chamber 418. The first chamber 394 is formed by the lower portion of the central housing 358, the holder 370 for the ignition assembly, and the bottom surface of the partition wall 390, and the first chamber 394 is formed adjacent to the ignition assembly 374. The first chamber 394 of the gas generator housing 366 essentially has a propellant grain 404 that increases the flow of gas to the air / safety bag 18 (see FIG. 1) upon ignition. Propellant gas is formed to achieve this. As a result, the first chamber 394 can be characterized as a propellant chamber. To assist in igniting the propellant grains 404, a suitable igniter / booster 408 (eg, an RDX / aluminum booster containing 89 wt% RDX and 11 wt% aluminum powder, or the same RDX / aluminum.
0.5 to 5.0 wt% of the booster agent RDX and a booster agent in which aluminum is replaced with 0.5 to 5.0 wt% of hydroxypropylcellulose may be used) at least a portion of the ignition assembly 374. It may be centrally located in the first chamber 394 for alignment. A suitable screen 412, booster cup or the like can separate the propellant grains 404 from the ignition / booster 408.

The first chamber 394 is generally connected to the high-pressure gas housing 354 by at least one bleed orifice or bleed port 400 (two in this embodiment). As a result, the pressurized medium is also contained in the first chamber 394 in a static state as described above. In this embodiment, the bleed ports 400 extend in a radial direction (ie, the bleed ports 400 are each arranged to extend along a radius having its origin on the central axis 220), and extend in a substantially horizontal direction. (Ie, center axis 352
Are included in a plane that extends in a direction orthogonal to. Selection of the size and / or quantity of the bleed ports 400 can be used to properly adjust the performance of the inflator 350 as described above in the inflator 202.

As described in detail below, the gas formed by the ignition of the ignition / booster agent 408 is supplied to the inflator 3
The 50 can be further chemically reacted with the pressurized medium to further enhance the properties of the onset of flow by rapid pressurization.

The guidance of a portion of the propellant gas from the first chamber 394 into the high pressure gas housing 354 is to achieve the desired output or discharge to the air / safety bag 18, ie, air / safety. It can be used to achieve the desired inflation rate of bag 18. As will be described in more detail below, the propellant gas is supplied to the high pressure gas housing 35 at a rate that maintains a substantially constant flow of gas from the high pressure gas housing 354 to the second chamber 418 for a sufficient period of time.
4 is preferably provided. Generally, less than half of the propellant gas formed to achieve the desired result (e.g., no more than about 40% of the propellant gas, and more typically, no more than about 30% of the propellant gas). During the operation of the high-pressure gas housing 354).
It needs to flow in.

The pressure increase in the high pressure gas housing 354 after ignition of the propellant grains 404, even with the bleed port 400, is significantly less than in many other commercial hybrid inflators. That is, the significant pressure build-up generally associated with ignition of propellant grains 404 is substantially confined within gas generator 362. As a result, the strength condition of the high-pressure gas housing 354 can be reduced.
This allows at least one of reducing the wall thickness of the high-pressure gas housing 354 and / or using a lightweight material for the high-pressure gas housing 354. Both of these reduce the weight of the inflator 350. For example, if the high pressure gas housing 354 is formed from mild steel and its internal pressure in the static state is about 4,000 pounds (4,000 psi) per square inch (6.45 square centimeters), the high pressure gas housing 354 may be used. The maximum required wall thickness of the wall is about 0.0
It can be 75 inches (about 1.91 mm).

The main flow of propellant gas from the first chamber 394 (eg, at least about 50%, and more typically at least about 70% of the total flow of propellant gas) is in the second chamber 418
(Referred to as "afterburner" for the reasons described above). The second chamber 418 of the gas generator housing 366 is connected to the first chamber 39 of the gas generator housing 366.
4, at least one propellant gas vent 416
(In this embodiment, two), and the propellant gas vent 416 extends through the gas generator partition 390. As will be described in further detail below, the primary flow path for the pressurized medium present in the high pressure gas housing 354 to the air / safety bag 18 (see FIG. 1) is further directly connected into the second chamber 418. I have. In order to achieve sufficient mixing of the propellant gas flowing from the first chamber 394 into the second chamber 418 and the pressurized medium flowing into the second chamber 418 from the high pressure gas housing 354 (e.g. The propellant gas vent 416 is oriented to form a vortex (eg, a flow with at least a radial velocity component) within the second chamber 418 so as to remain within the second chamber 418 for a sufficient amount of time. It is possible. One way to create this vortex is to form the propellant gas vent 416 of the gas generator to extend substantially linearly, as shown in FIG. The vents 416 are arranged so as to be inclined to opposite sides in the corresponding plane.

The second chamber 4 of the gas generator housing 366
18 are aligned with the first chamber 394 along its length and are separated by a gas generator partition 390 into the first chamber 3.
94 and a housing 354 for high pressure gas.
Are arranged along its outer periphery. Second room 4
Reference numeral 18 denotes an intermediate portion of the central housing 358, the gas generator partition 390, and the gas generator end cap assembly 4.
20. The gas generator end cap assembly 420 is suitably coupled to the central housing 358 (eg, by welding at a weld 454), with the upper portion of the central housing 358 relative to the upper portion of the high pressure gas housing 354. Appropriately connected (for example, connection by welding at the welding portion 450). Since the second chamber 418 has a large amount of pressurized medium in a static state, the welds 450, 454 preferably form a hermetic seal. The gas generator end cap assembly 420 has at least one gas generator outlet 424 (one shown). To form a hermetic seal for properly holding the pressurized medium in the inflator 350, particularly the second chamber 418, for a desired time, the second closure disk 428 is attached to the gas generator end cap assembly 420. (For example, connection by welding at the welding portion 454).

The communication between the first chamber 394 and the second chamber 418 provides at least one of the propellant gas formed by the combustion of the propellant grains 404 and the gas formed by the ignition of the igniter / booster 408. The section is guided into the second chamber 418. Due to the rapid pressure increase in the second chamber 418 based on the control detailed below, the second closing disc 428 is opened at the appropriate time. As a result, the gas flow from the inflator 350 is guided to the diffuser 458 and the air / safety bag 18 (see FIG. 1). Diffuser 458 includes a plurality of diffuser ports 462 to provide less disruptive gas output to air / safety bag 18 (see FIG. 1). The diffuser 458 retains the broken closure disc debris within the inflator 350 and provides the propellant gas and pressurized medium before the propellant gas and pressurized medium pass into the air / safety bag 18 (see FIG. 1). A diffuser screen (not shown) to achieve at least one of mixing the medium and / or further enhancing the reaction.
It is possible to have

The second chamber 418 is a high pressure gas housing 3
It communicates with 54. In this regard, at least one,
Preferably, a plurality of gas generator inlets 432 provide communication between the high pressure gas housing 354 and the second chamber 418. As a result, the pressurized medium in the high-pressure gas housing 354 flows into the second chamber 418 in a timely manner. That is,
In a particular design or application, the flow of this particular gas can control the direction of the flow. In particular, valve 438 can be located adjacent to at least one, and preferably all, gas generator inlets 432. In the static state, the valve 438 need not actually separate the high pressure gas housing 354 from the second chamber 418 in this region. In fact, large volumes of pressurized medium are preferably retained in the second chamber 418 in a static state, and a connection that is not hermetically sealed can provide such a supply. One form of valve 438 that does not separate the second chamber 418 from the high-pressure gas housing 354 over the gas generator inlet 432 is a roll-shaped filling material (eg, 0.
002 inches (about 0.05 mm) of stainless steel). A cantilever connection can be used between the valve 438 and the inner wall of the gas generator housing 366. That is, the rear of the valve 438 is
And the valve 438 is movable / deflectable because it is coupled between the septum 390 and the front of the valve 438 is not coupled to the other.

Although the current shape of the valve 438 is preferable, individual plugs 438a and 438b (FIG. 14) are used.
(A), (B)) can be arranged in each entrance 432. These plugs 438a and 438b are desirably connected to the inflator 350 by a tether 439 or the like (shown only in FIG. 14B). Further, it is desirable that the plugs 438 a and 438 b be supported in the inlet 432 by the flexible member 433. Plug 438
a, 438b can also be used with the other hybrid inflators described herein.

From the above, the high pressure gas housing 3
It can be seen that the pressure spreading inside each of 54 and gas generator 362 is approximately equal in the static state. However, in the dynamic state or after ignition of the propellant grains 404, the pressure in each chamber of the inflator 350 is different from each other to achieve the desired performance. Propellant grain 404
When the ignition is performed on the second chamber 4
Begin flow into at least the second chamber 418 to increase the pressure in 18. When the inflator 202 has at least one bleed port 400, a part of the propellant gas flows into the high-pressure gas housing 354, and
The pressure in the high-pressure gas housing 354 is increased.
The rate of pressure increase in the second chamber 418 is preferably faster than the rate of pressure increase in the high-pressure gas housing 354. The difference in the rate of pressure increase is the second chamber 418
And the high-pressure gas housing 354 due to the flow of the propellant gas and their relative volume differences. This pressure differential causes valve 438 to have a matched gas generator housing 366 with valve 438.
Is pressed against a part of the inner wall of the. As a result, the high-pressure gas housing 354 is isolated from the second chamber 418 by blocking the gas generator inlet 432. The cantilever connection of valve 320 is
0 movement is possible. If the pressure in the second chamber 418 reaches a predetermined pressure value, the fluid pressure will open, break or break the second closure disk 428. As a result, the opening of disk 428 creates a flow of gas from gas generator 362 to diffuser 458 and air / safety bag 18 (see FIG. 1).

The valve 438 allows for a timely gas flow to the air / safety bag 18 (see FIG. 1) in a particular design or application. In particular, in certain designs, the use of valve 438 allows the second chamber 418 to be rapidly pressurized at a rate that allows the second closing disk 428 to be opened in a timely manner. Inflator 35
If the zero has no valve 438, the propellant gas flows from the second chamber 418 into the high pressure gas housing 354.
In this case, it takes a longer time for the internal pressure of the second chamber 418 to increase to a pressure value at which the second closing disk 428 can be broken. However, the use of the second chamber 418 provides a smaller pressurized chamber, which reduces the time required to initiate gas flow to the air / safety bag 18 (see FIG. 1). As will be described in more detail below, the volume of the second chamber 418 may be sufficiently small in certain designs, and the propellant and pressurized medium may be adjusted to achieve satisfactory operation without the use of the valve 438. At least one of the selections can be performed (e.g., propellant grains 404 and ignition / booster agent 4 to affect rapid pressurization in second chamber 418).
18 by utilizing the combustion of the gas formed by the combustion of at least one of 18).

The valve 438 maintains its position after the second closure disk 428 is opened to create a flow of gas to the air / safety bag 18 (see FIG. 1), and thereby maintains the gas flow. The generator inlet 432 is shut off for a specified time. However, if a particular pressure differential is created between the high pressure gas housing 354 and the second chamber 418, the upper free end of the valve 438 will be forced by this pressure differential to expose the gas generator inlet 432. Be moved. As a result, the flow of gas from the high-pressure gas housing 354 into the second chamber 418 is started. The lower end of the valve 438 is located at the gas generator housing 366.
Is maintained in a coupled state. If the valve 438 is formed from a rolled fill material, the valve 438 may move radially inward toward the central axis 352 or may be radially aligned with the gas generator inlet 432. The valve 438 is recessed into the defined area to allow the desired gas flow therethrough.

The second closing disk 42 is formed by rapid pressurization.
The main function of the second chamber 418 after the breakage of the propellant gas and pressurized medium is before the propellant gas and pressurized medium are discharged into the air / safety bag 18 (see FIG. 1). To provide or tolerate effective mixing of Propellant compositions of the type described above (e.g., gun-type propellants, hybrid propellants) and pressurized media of the type described above (e.g., an inert fluid and oxygen, represented by at least one inert gas). If used, this mixture provides a significant effect (including, for example, reducing toxicity and reducing the total amount of propellant by further burning and increasing the expansion capacity associated therewith). This results in further combustion of the propellant gas. In this case, the second chamber 418 is further characterized as an afterburner. Preferably, at least about 99% of the total combustion of the gas formed by the propellant gas and the igniter / booster agent occurs in the inflator 350, and more preferably about 100% of such combustion. This reduces the risk of damage to the air / safety bag 18 (see FIG. 1).

Due to the constraints imposed on the driver side use, it is not practical to use a "long" second chamber 418 as used in the inflator 202 to provide afterburner functionality. In order to supplement the use of the "short" second chamber 418 when using the inflator 350 on the driver side, the mixing of the propellant gas and the pressurized medium in the second chamber 418 can be further enhanced, This mixing can be performed from the high pressure gas housing 354 to promote mixing of the pressurized medium and the propellant gas into the second chamber 4.
This may be achieved by introducing a vortex into the gas flow to 18 (primarily a pressurized medium, or a large amount of propellant gas and / or gas formed by ignition / ignition of the booster agent).
This increases the residence time of the propellant gas and pressurized medium in the second chamber 418 to chemically react the propellant gas and pressurized medium.

One way to form the vortex is to arrange a generally linear gas generator inlet 432 in a substantially horizontally extending reference plane, as shown in FIG. The central axis of the inlet 432 extends in the longitudinal direction of the inflator 350 as shown in FIG.
Can be realized by orienting them so as not to pass through. That is, the substantially linearly extending inlet 432 may extend radially outward from a longitudinally extending central axis 352 to connect the second chamber 418 and the high pressure gas housing 354. Absent. Alternatively, a portion of any of the inlets 432 is located on one radially extending line, and another portion of any of the inlets 432 is located on another radially extending line. In this case, the flow of gas from the high-pressure gas housing 354 to the second chamber 418 is generally formed along the direction of arrow A shown in FIG. In order to effect further mixing of the propellant gas and the incoming pressurized medium, the propulsion gas vent 416 shown in FIGS. Can be formed.

The dimensions of any design of the inflator 350 can be changed. In particular, the capacity of each chamber of the inflator 350 differs depending on the use of the inflator. For example,
The overall volume of the inflator housing is from about 50 cm ³ to about 150 cm ³ , the volume of the first chamber 394 is from about 5 cm ³ to about 15 cm ³ , and the volume of the second chamber 418 is from about 1 cm ³ to about 20 cm ³ . In order to show the principle of the present invention, its dimensions in one embodiment are exemplified below. 1) The diameter of the inflator 350 is about 3.25 inches (about 8.2
6 cm). 2) The height of the central housing 358 is about 1.6 inches (about 4.06 cm). 3) The height of the high-pressure gas housing 354 is about 1.2 inches (about 3.0 inches).
5 cm). 4) The internal volume of the high pressure gas housing 354 is about 5 cubic inches (about 82 cubic centimeters)
It is. 5) The interior volume of the first chamber 394 of the gas generator housing 366 is about 7 cc. 6) The interior volume of the second chamber 418 of the gas generator housing 366 is about 2
cc. 7) The inflator 350 has two bleed ports 400 having a diameter of about 1.5 mm. 8) The inflator 350 has two propellant gas vents 416 with a diameter of about 2 mm. 9) The total weight of propellant grains 404 is about 3.5 g, and the propellant grains include a composition of the type described above with RDX, CA, TMETN and stabilizers. 10) High pressure gas housing 35
4, the static pressure in the high pressure gas housing 354 contains about 40 g of pressurized medium, and 85% (mole percent) of the pressurized medium is argon; Percent (mol percent) is oxygen. 1
1) The inflator 350 is made of mild steel. 1
2) The wall thickness of the high-pressure gas housing 354 is about 0.0
75 inches (1.91 mm) and a pressure ratio (Pr
The essure rating is about 18,000 psi. 13) The wall thickness of the central housing 358 is about 0.0
625 inches (1.59 mm). 14) The total weight of the inflator 350 is about 400 g.

The operation of the inflator 350 will be described in detail with reference to FIGS. 11A to 11C. As shown in FIG. 11A, when an appropriate signal is transmitted from the detector / sensor 14 (see FIG. 1), the ignition assembly 374 is activated, and the ignition assembly 374 breaks the first closure disc 378, Further, ignition of the ignition / booster agent 408 is performed. The propellant grains 404 are then ignited by the ignition of the ignition / booster agent 408. Propellant grain 404
Propellant gas is formed in the first chamber 394 by the combustion of
The propellant gas is supplied to the second chamber 4 of the gas generator housing 366.
18 and into the high pressure gas housing 354, where it is mixed with the pressurized medium. The presence of the hot propellant gas in the first chamber 394 and the flow of the hot propellant gas into the second chamber 418 and the high-pressure gas housing 354 also increase the pressure in these vessels.

In order to break the second closing disk 428 in a timely manner and thereby start the flow of gas to the air / safety bag 18 (see FIG. 1), the second chamber 418 and the high pressure gas housing 354 The rate of pressure increase in the second chamber 418 further increases the rate of pressure increase in the high-pressure gas housing 354 based on the flow of the high-temperature propellant gas into the second chamber 418 and the capacity of the second chamber 418 and the high-pressure gas housing 354. Designed to exceed. As shown in FIG. 11A, this pressure differential urges valve 438 against the inner wall of gas generator housing 366 to separate high pressure gas housing 354 from second chamber 418 in this region. This stops the supply of the pressurized medium that reacts with the propellant gas, so that the pressurized medium in the second chamber 418 in a static state prior to establishing communication between the high pressure gas housing 354 and the second chamber 418 The total amount of the second room 4
It must be sufficient to react with the propellant gas flowing into 18.

As shown in FIG. 11B, when the pressure in the second chamber 418 reaches a predetermined pressure value, the pressure breaks the second closing disk 428, thereby passing through the gas generator outlet 424. Thus, a flow of gas flowing into the diffuser 458 and the air / safety bag 18 (see FIG. 1) is formed. However, valve 438 closes gas generator inlet 432, thereby continuing to inhibit direct flow of gas from high pressure gas housing 354 into second chamber 418. After a certain pressure difference is formed between the high pressure gas housing 354 and the second chamber 418,
This pressure differential causes the valve 438 to move or deflect away from the gas generator inlet 432 to form a flow of pressurized medium from the high pressure gas housing 354 to the second chamber 418. For example, the valve 43 shown here
With the construction of FIG. 8 (such as a roll of filling material), the one-way check valve 438 will fall into at least the area adjacent or aligned with the gas generator inlet 432 due to the pressure differential. First chamber 394 as described above
Second chamber 418 to facilitate mixing of the pressurized medium and the propellant gas that continuously flow into the second chamber 418 through the second chamber 418.
The flow of the pressurized medium and the propellant gas into it may be vortex.
This allows the pressurized medium and the propellant gas to flow through the air / safety bag 1
8 (see FIG. 1) may increase the time that the mixture of pressurized medium and propellant gas is held in the second chamber 418 before being fed into the second chamber 418.

FIG. 12 shows a plurality of pressure curves for the test model of the embodiment with similar dimensions and characteristics. These curves are shown in FIG.
13D is almost the same as the curve shown in FIG. The initial static pressure in the inflator 350 is about 4,000 psi. At time T1 (about 5 milliseconds), the inflator 3
50 was activated and the propellant grains 404 ignited. At this time, the internal pressure of each of the first chamber 394, the high-pressure gas housing 354, and the second chamber 418 was increased by the propellant gas generated by the ignition of the propellant grains 404. The maximum pressure in the first chamber 394 and the second chamber 418 was established at time T2, at which point the second closure disk 428 broke. Time T2
At about 1 millisecond after activation, the pressure in the first chamber 394 is increased from a static state of 4,000 psi to about 10,000
0 psi and the pressure in the second chamber 418 is 4.0
From a static state of 00 psi to about 7,000 psi, and the pressure in the high pressure gas
It increased from a static state of 00 psi to about 4,500 psi.

After the second closing disk 428 was opened, the pressure in the second chamber 418 dropped. At time T3, the pressure difference between the high pressure gas housing 354 and the second chamber 418 has reached a value sufficient to open the valve 438, thereby exposing the gas generator inlet 432. As a result, the pressure in the second chamber 418 increased again. That is, after the elapse of the time T3, the gas flowed from the high-pressure gas housing 354 and the first chamber 394 to the second chamber 418. The pressure in the second chamber 418 increased to a maximum of about 4,750 psi at time T4, after which the pressure decreased. This time substantially coincided with the time at which a maximum pressure of about 5,000 psi was built up in the high pressure gas housing 354. At this time, the pressure increase generated in the inflator 350 was mainly concentrated in the gas generator 362 rather than in the high-pressure gas housing 354. As a result, the wall thickness of the high-pressure gas housing 354 can be reduced as described above. Furthermore, the desired pressure can be provided to the air / safety bag 18 (see FIG. 1) because the internal pressure of the second chamber 418 is relatively constant (only varies between 4000 and 4600 psi).

As noted above, in certain designs, inflator 350 may be configured as described above, except for the use of valve 438. This can be achieved through the use of a propellant and a pressurized medium of the type described above, which propellant in the second chamber 324 includes an oxidized pressurized medium (eg, containing one or more inert gases such as argon and nitrogen). By mixing with an inert fluid and an oxidizing pressurized medium composed of a complex of oxygen (typically, a propellant gas that can be further burned in the second chamber 418). In this case, the "second" combustion of the propellant gas occurring in the second chamber 418 and the second combustion of the gas formed by the ignition of the ignition / booster agent 408 is such that the valve 438 is not required. Produces a sufficient pressure increase or rate of pressure increase. For example, the second chamber 41 after activating the inflator 350
The second combustion occurring within 8 accounts for at least about 30% of the pressure increase or rate of pressure increase, up to about 50%.
%. In this case, the second chamber 41
The initiation of flow by rapid pressurization can be realized using the chemical reaction in 8, which reduces the need for valve 438.

FIGS. 13A to 13D show the first chamber 394, the second chamber 418, the high-pressure gas housing 354, and the air / safety bag 18 (FIG. 1) of the inflator 350 having the above-described structure except for the valve 438. 2) shows a pressure curve representing the internal pressure of each of the containers with fixed walls. As is clear from the comparison between FIG. 12 and FIGS. 13A to 13C, equivalent performance can be realized without using the valve 438. This is a particular type of propellant and pressurized medium that provides for combustion of gas in the second chamber 418 to provide rapid pressurization in the second chamber 418 to open the second closure disk 428. This is basically caused by using.

FIG. 15 shows a modification of the hybrid inflator of the present invention. Since the inflator of this modified example has a configuration similar to that of the inflator of FIG. 5, the similarities are referred to by the same reference numerals, and description thereof is omitted. Differences from the inflator of FIG. I do.

The first chamber 501 has a larger inner diameter than the second chamber 502. The length of the second chamber 502 is set to be significantly shorter than that of the second chamber 324 of FIG. Therefore, the second chamber 502 has a much smaller capacity than the first chamber 501. Second chamber 50 in this embodiment
The capacity of the second chamber 501 is about 1/20 of the capacity of the first chamber 501.

The transmission tube 503 is arranged on the axis of the first chamber 501, and connects the initiator 228 and the aspirator nozzle 274. The transmission tube 503 has a hollow shape, and has a plurality of ventilation holes 504 on the peripheral wall thereof. Therefore, the first chamber 501 is divided into the second chamber 502 by the heat transfer tube 503 and the aspirator nozzle 274.
Is in communication with Also, the first closing disk 236 always closes the passage 507 between the initiator 228 and the first chamber 501.

The second chamber 502 is connected to the outlet 286 by an afterburner pipe 505. A second closing disk 290 located near the second chamber 502 and the aspirator nozzle 274 always closes the outlet 286 via the pipe 505.

The bleed port 262 connects the first chamber 501 with the inside of the high-pressure gas housing 204. Entrance 31
6 is provided in the second chamber 502, and in a static state,
Since the valve 320 is not in close contact with the inner wall of the second chamber 502, it is open. Therefore, in the static state,
The pressure inside the high-pressure gas housing 204, the first chamber 501, and the second chamber 502 is kept almost uniform by the aspirator nozzle 274, the transfer tube 503, the inlet 316, and the bleed port 262. In this state, when the initiator 228 is operated, the first closing disk 236 is broken, and the propellant 258 is burned. After the combustion gas generated from the propellant increases the pressure in the first chamber 501,
The pressure inside the second chamber 502 is increased through the transfer tube 503 and the aspirator nozzle 274. The pressure causes valve 320 to move toward the wall of second chamber 502, closing inlet 316. Then, the combustion gas is injected from the aspirator nozzle 274 into the pipe 505 and destroys the second closing disk 290.

Then, the pressure in the second chamber 502 temporarily decreases, and the valve 320 opens the inlet 316. Thus, the pressurized medium enters the second chamber 502 as well as the pipe 505 through the inlet 316. Thereafter, the oxygen in the pressurized medium chemically reacts with carbon monoxide and hydrogen in the combustion gas in the second chamber 502 and the pipe 505 to be converted into carbon dioxide and water. These high-pressure carbon dioxide, water, and argon in the pressurized medium pass through the outlet 286 and are supplied from the diffuser 508 to an airbag (not shown) to inflate the airbag.

As described above, in this embodiment, the second chamber 5
02 is set smaller than the first chamber 501, and a second closing disk 290 is arranged near the aspirator nozzle 274. Therefore, in addition to exhibiting the same operation and effect as the inflator shown in FIGS. 5 and 8,
The pressure of the combustion gas in the first and second chambers 501 and 502 is rapidly increased, so that the disk 290 can be quickly destroyed.

Further, a large number of air holes 5 are provided in the first chamber 501.
Since the heat transfer tube 503 provided with the fuel gas 04 is disposed, the flow velocity of the combustion gas when passing through each ventilation hole 504 can be increased. This assists in the early destruction of the disk 290.

It should be noted that the transfer tube 503 can be applied to the embodiment shown in FIG. Regarding the opening area of the aspirator nozzle and the sum of the opening areas of the bleed ports in the embodiments of FIGS. 5 and 8, the pressurized medium is introduced into the first chamber or the combustion gas of the propellant is added. Depending on whether it leads to the pressure medium side
It is possible to determine which area to increase.

Table 2 shows the physical characteristics of each of the inflators shown in FIGS. 5, 8, and 14, that is, the features of the present invention. For example, Table 2 shows the numerical ranges for propellant grains, propellant gases and pressurized media.

[0139]

[Table 2] If each of the characteristic values shown in Table 2 is below the lower limit, a sufficient amount of gas for inflating the air safety bag cannot be obtained. Further, when each characteristic value exceeds the upper limit value, the whole inflator cannot be sufficiently reduced in size. Further, in the inflator of the present invention, it is indispensable to provide the conditions regarding the weight of the propellant shown in Table 2. However, other characteristics can be appropriately selected as needed.

FIG. 16A shows a hybrid inflator according to another embodiment of the present invention.
Can be incorporated into the inflatable safety system 10. The inflator 614 includes a cylindrical inflator housing 622 with a pressurized medium 620 for supplying the air / safety bag 18 (FIG. 1), and a pressurized medium 620.
A gas generator 624 that generates propellant gas to inflate the airbag and increases flow to the air / safety bag 18.

The inflator 614 is mounted on a vehicle seat or door, and is used to protect an occupant when a shock is applied to the vehicle from the side (for example, a side impact inflator). The pressurized medium 620 contains an inert gas such as argon and oxygen.

A gas generator housing 644 is fixed to the opening 642 at the right end of the inflator housing 622 by welding, and a part thereof is disposed in the inflator housing 622. A propellant 64 that generates a propellant gas during combustion is provided in a storage chamber 645 of the gas generator housing 644.
6 are accommodated, and an ignition assembly 648 is mounted. Gas generator housing 644 and ignition assembly 648 are aligned with axis 6 of inflator housing 622.
17.

The propellant 646 is a nitramine type,
For example, those containing about 70% by weight RDX (hexahydrotrinitrotriazine), about 5 to about 15% by weight cellulose acetate and about 5 to about 15% by weight GAP (glycidyldiazide polymer) are desirable. This propellant generates a combustible gas containing carbon monoxide and hydrogen during combustion.

The gas generator housing 644 has a communication hole 650 at the inner end thereof, and the communication hole 650 is always closed by the first disk 652. A ring-shaped connector 626 is fixed to the left end opening 625 of the inflator housing 622 by welding. Connector 626
The opening 628 at the left end of the cap has a cap-shaped diffuser 63.
0 is fixed. The diffuser 630 is a peripheral wall 630
a and a top wall 630b, and a plurality of ventilation holes 632 are formed in the peripheral wall 630a. Diffuser 630
Is located on the axis 617 of the inflator housing 622 and is connected to the air / safety bag 18 (FIG. 1).

The opening at the right end of the connector 626 forms an outlet 634 of the inflator housing 622.
A second disk 636 is mounted on the outlet 634, and the outlet 634 is always closed. The diffuser 630 has an opening 630c communicating with the outlet 634. The connector 626 is provided with a cap 64 having a plurality of vents 638 so as to cover the outlet 634.
0 is attached. Therefore, the inside of the inflator housing 622 is always sealed by the two disks 636 and 652 and the peripheral wall of the inflator housing 622. Further, when the first disk 652 and the second disk 636 are destroyed, the communication hole 650 causes the accommodation chamber 64 to break.
5 communicates with the inside of the inflator housing 622, and the inside of the inflator housing 622 communicates with the outlet 634 through a vent 638.

The first disk 652 and the second disk 6
Desirably, the spacing between C.36 and C.36 is between about 20 mm and about 70 mm. If this interval is below the lower limit, not enough gas is obtained to inflate the air / safety bag 18 (FIG. 1), and if it is greater than the upper limit, the inflator will not be sufficiently miniaturized. The inflator housing 62
The amount of the pressurized medium in 2 is from about 40 cm ³ to about 100 cm ³
It is. The amount of the pressurized medium 620 is set based on the same reason as the above-mentioned interval. More preferably, about 50c
m ³ to about 90 cm ³ . Further, the inside of the inflator housing 622 is maintained at a high pressure of about 4000 psi.

Now, when the ignition assembly 648 is operated according to the signal from the detector 612, the propellant 64
6 combusts to generate combustible gas. This gas contains carbon monoxide and hydrogen. This gas also increases the pressure in the gas generator housing 644 and destroys the first disk 652. Then, the flammable gas flows into the communication hole 650.
Flows into the inflator housing 622 where it is mixed with the pressurized medium 620.

The pressurized medium 620 contains oxygen. This oxygen reacts with carbon monoxide and hydrogen in the combustible gas to produce carbon dioxide and water vapor. The combustible gas increases the pressure in the inflator housing 622, which acts on the second disk 636 via the vent 638.
That is, gas must flow around end wall 641 of cap 640 and enter hole 638. This facilitates more complete combustion within the housing 622. Thus, the end wall 641 of the cap 640 functions as a so-called propellant trap and is located at the outlet to the inflator 614.

Further, since the end wall 641 of the cap 640 is disposed on the axis 617, the first disk 652
Is prevented from being directly injected into the second disk 636. Then, the propellant gas sufficiently reacts with the pressurized medium in the housing 622 and then passes through the hole 638 in the peripheral wall of the cap 640 and collides with the second disk 636. Therefore, the carbon monoxide contained in the propellant gas passes through the outlet 634 after being completely oxidized.
Then, the second disk 636 is destroyed, and high-pressure carbon dioxide, water vapor, and inert gas are supplied to the air / safety bag 18 (FIG. 1) through the outlet 634 and the vent 632 of the diffuser 630, and the air / Safety bag 18
(FIG. 1) is effectively expanded by a predetermined amount within a predetermined time.

As described above, in this embodiment, since the first and second disks 652 and 636 and the diffuser 630 are disposed on the axis 617 of the inflator housing 622, the entire inflator is formed into a compact cylinder. be able to. Therefore, it can be securely mounted in a limited space such as the inside of a vehicle door or seat without changing the shape of the door or seat.

In this embodiment, the propellant 646 generates a combustible gas containing carbon monoxide and hydrogen during its combustion. The gas reacts with oxygen in the pressurized medium 620 and is converted to carbon dioxide and water. Thus, the gas / safety bag 18 (FIG. 1) can be inflated with a gas that is harmless to the occupant.

The diffuser 630 has a cap shape, has a peripheral wall 630a and a top wall 630b, and has an opening 630c communicating with the outlet 634.
30a has a plurality of holes 632 communicating with the opening 630c. Accordingly, when gas is released from the inflator housing 622, the gas can be injected in all directions from the plurality of holes 632 to more efficiently inflate the air / safety bag 18 (FIG. 1).

FIG. 16B shows a modification of the inflator shown in FIG. In this modification, the gas generator housing 644 includes a base portion 660 and a chamber portion 662. Base portion 660 supports ignition assembly 648. The chamber portion 662 includes the propellant 64
6 are accommodated. Disk 664 has a base portion 660
And the chamber portion 662 and are sandwiched therebetween. The disk 664 is provided in the through hole 6 of the chamber portion 662.
66 is always closed. The chamber portion 652 is a communication hole 65
0 and communicates with the inflator housing 622. Accordingly, the interior of chamber portion 652 is under pressure.

When the ignition assembly 648 is operated,
The ignition assembly 648 destroys the disk directly and burns the propellant to generate combustible gas. The combustible gas reacts with oxygen in the pressurized medium 620 and is converted into carbon dioxide and water vapor. Thus, the air / safety bag is inflated with a gas that is substantially harmless to the occupant.

The foregoing description of the invention has been presented for purposes of illustrating and explaining the invention. The description of the present invention is not intended to limit the present invention to the form disclosed herein. Therefore, changes and modifications considered to be equivalent to the above-described techniques, and changes and modifications based on the related art and the knowledge related thereto, are included in the scope of the present invention. Furthermore, the embodiments disclosed herein illustrate the best mode for carrying out the invention, and others skilled in the art may refer to these embodiments, or other embodiments, for adapting the particular applications or uses of the invention. It is intended to be able to be used together with various changes required for. The claims of the present invention are intended to include other embodiments within the scope permitted by the prior art.

[0156]

As described in detail above, the present invention has an excellent effect that the propellant gas and the pressurized medium can be quickly mixed and burned under pressure to inflate the airbag.

[Brief description of the drawings]

FIG. 1 is a schematic view of an inflatable safety system for a motor vehicle.

FIG. 2B is a longitudinal sectional view of one embodiment of the hybrid inflator. (A) is an enlarged vertical cross-sectional view of a portion A of (B).

FIG. 3 is an internal pressure / time performance curve of an inflator for the composition of the propellant of Example 2.

FIG. 4: Gas tank pressure / propellant composition for Example 2
Time performance curve.

FIG. 5 is a longitudinal sectional view of another embodiment of the hybrid inflator.

6A to 6D are enlarged longitudinal sectional views of the valve and the closing disk of the inflator of FIG. 5 at different times during operation.

FIG. 7 is an end view of the valve of FIGS. 6 (A) to 6 (D).

FIG. 8 is a longitudinal sectional view of another embodiment of the hybrid inflator.

FIG. 9 is a sectional view of the central housing taken along line 9-9 in FIG. 8;

10 is a perspective view of the bulkhead of FIG. 8 between the first and second chambers of the gas generator housing, showing the arrangement of the vents for the propellant gas.

11A to 11C are enlarged longitudinal sectional views of the valve and the closing disk of the inflator of FIG. 8 at different times during operation.

FIG. 12 is a graph showing internal pressures of various chambers during operation of the inflator of FIG. 8;

13 (A) to (D) show various chambers (first chamber, second chamber, housing for high pressure gas and air / air) during operation of the inflator of FIG. 8 when the valve / valve system is not used. Graph of the internal pressure of the safety bag).

14 (A) and (B) are cross-sectional views showing a modification of the valve for the hybrid inflator of FIGS. 5 and 8;

FIG. 15 is a longitudinal sectional view showing another embodiment of the hybrid inflator.

FIG. 16A is a longitudinal sectional view showing another embodiment of the hybrid inflator. FIG. 16B is a modified example of the hybrid inflator shown in FIG.

[Explanation of symbols]

36 ... Pressurized medium, 204,622 ... Inflator housing, 212,366,644 ... Gas generator housing, 254,394,501 ... First chamber, 258,40
4 ... propellant (propellant grain), 262,400 ... bleed port, 286, 424, 634 ... outlet, 290 ... main closing disk, 324, 418, 502 ... second chamber, 228,
374,648: ignition assembly.

──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Brent A. Parks United States 80111 Englewood, Colorado South Macon Way 6153 (56) References JP-A-5-147490 (JP, A) JP-A-6-316247 (JP, A) JP-A-8-40178 (JP, A) Japanese Translation of PCT Application No. Hei 6-508320 (JP, A) US Patent 5060974 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60R 21/26

Claims (45)

(57) [Claims] 1. A hybrid inflator for an inflatable vehicle safety system including an air / safety bag, comprising: an inflator housing containing a pressurized medium; a gas generator housing connected to the inflator housing; The generator housing includes a first chamber containing a propellant; an ignition assembly for igniting the propellant; and a propellant gas communicating with the first chamber and the inflator housing and generating propellant gas from the ignited propellant. A second chamber for combustion by a pressurized medium; an outlet provided in the gas generator housing for supplying the pressurized medium and propellant gas from the second chamber to an air / safety bag; A main closure disk that always closes the outlet and is destroyed after ignition of the propellant; The chamber and the main closure disk is disposed on the same axis in this order, and said gas generator housing comprises at least one bleed port for maintaining substantially equal pressure in the inflator housing and the first chamber,
Further, the first chamber and the second chamber are formed in a partition between the two chambers.
Hybrid inflator that is communicated by the formed communication hole . 2. The hybrid inflator according to claim 1, wherein said ignition assembly includes an initiator. 3. The ignition assembly includes an initiator,
2. The hybrid inflator according to claim 1, further comprising a sub-closing disk that always interrupts communication between the first chamber and the initiator, wherein the sub-closing disk is disposed on the axis. 3. 4. The ignition assembly includes an initiator,
A booster agent ignited by the initiator, and a sub-closing disk that always interrupts communication between the first chamber and the initiator and is destroyed when the booster agent is ignited. The hybrid inflator according to claim 1, wherein is disposed on the axis. 5. The hybrid inflator according to claim 1, wherein said pressurized medium is housed in said inflator housing so as to surround said gas generator housing. 6. The inflator housing includes a donut-shaped high-pressure gas housing, the gas generator housing has a substantially cylindrical shape, and the high-pressure gas housing is disposed around the gas generator housing. Item 6. A hybrid inflator according to Item 5. 7. The hybrid inflator according to claim 6, wherein a plurality of said bleeding ports are provided and are arranged radially with respect to said axis. 8. The first chamber and the second chamber are separated by a dome-shaped partition, and the ignition assembly is disposed inside the first chamber so as to be close to the partition, and the ignition assembly is provided. The hybrid inflator according to claim 6, wherein the propellant is disposed around the periphery of the vehicle. 9. The partition according to claim 8, wherein the partition has a plurality of vents communicating the first chamber and the second chamber, and the vents are arranged obliquely with respect to the axis. Hybrid inflator. 10. The capacity of the inflator housing is about 50 cm ³ to about 150 cm ³ , and the capacity of the first chamber is about 5 c.
m ³ to about 15 cm ³ , and the volume of the second chamber is about 1 cm ³
Hybrid inflator according to claim 6 is about 20 cm ³ from. 11. The second chamber includes a plurality of inlets for introducing the pressurized medium into the second chamber, each inlet being arranged to intersect a line extending radially from the axis. The hybrid inflator according to claim 6, wherein: 12. In the second chamber, after the ignition assembly is actuated, the pressure in the inflator housing exceeds the pressure in the gas generator housing by a predetermined amount.
12. The hybrid inflator of claim 11, comprising valve means operated in cooperation with said inlet to substantially prevent flow between the inflator housing and the gas generator housing through the inlet. 13. The inflator housing and the gas generator housing are substantially cylindrical, the gas generator housing is housed in the inflator housing, and both ends of the inflator housing are connected to both ends of the gas generator housing. The hybrid inflator according to claim 5. 14. The hybrid inflator according to claim 13, wherein a plurality of said bleed ports are provided and are radially arranged with respect to said axis. 15. The aspirator nozzle according to claim 13, wherein an aspirator nozzle is provided between the first chamber and the second chamber, the aspirator nozzle injecting the propellant gas toward the main closing disk. Hybrid inflator. 16. The capacity of the inflator housing is set larger than the capacity of the second chamber.
6. The hybrid inflator according to 5. 17. The hybrid inflator according to claim 15, wherein said second chamber has an inlet near said aspirator nozzle for introducing said pressurized medium into said second chamber. 18. A part of the inlet and the tip of the aspirator nozzle which is closest to the outlet is 4 mm from the outlet.
The hybrid inflator according to claim 15, wherein the hybrid inflator is separated from the hybrid inflator by 80 mm. 19. The second chamber further comprises a pressure in the inflator housing which exceeds a pressure in the gas generator housing by a predetermined amount after the ignition assembly is actuated.
16. The hybrid inflator according to claim 15, comprising valve means operated in cooperation with said inlet to substantially prevent flow between the inflator housing and the gas generator housing through the inlet. 20. The hybrid inflator according to claim 19, wherein said valve means is made of a flexible material and is disposed so as to surround said aspirator. 21. The first chamber includes a firing tube located on the axis in the interior thereof, the tube being connected to the aspirator nozzle and communicating a plurality of tubes with the interior of the tube and the first chamber. The hybrid inflator according to claim 15, further comprising a hole. 22. The capacity of the inflator housing is about 150 cm ³ to about 450 cm ³ , and the capacity of the first chamber is about 1 cm.
0 cm ³ to about 40 cm ³ , and the capacity of the second chamber is about 1 c
hybrid inflator of Claim 13 m ³ is about 50 cm ^3. 23. A hybrid inflator for an inflatable vehicle safety system with an air / safety bag, comprising: an inflator housing including a pressurized medium; a gas generator connected to the inflator housing; gas generator first chamber and a second chamber communicating with each other, propellant contained in the first chamber, at least one bleed port communicating the first chamber and the inflator housing, the second chamber and the inflator Having at least one gas generator inlet communicating with the housing, and at least one gas generator outlet ;
And the second chamber is formed by a communication hole formed in the partition between the two chambers.
Being in communication, a main closure disc located between all the gas generator outlets and the air / safety bag, and a propellant ignition assembly associated with the gas generator;
Ignition of the propellant to form a propellant gas; means for opening the main closure disc to initiate flow to the air / safety bag; and the means for opening combust the propellant gas in the second chamber. Means, wherein the propellant gas acts directly on the main closure disk. 24. The first chamber, the second chamber and the main closure disk are arranged on the same axis in this order.
4. The hybrid inflator according to 3. 25. The hybrid inflator according to claim 23, wherein said ignition assembly includes an initiator. 26. The ignition assembly as claimed in claim 1, wherein the ignition assembly comprises an initiator and a sub-closing disc which always interrupts the communication between the first chamber and the initiator, the sub-closing disc being arranged on the axis. Item 25. The hybrid inflator according to item 24. 27. The ignition assembly according to claim 27, wherein the initiator, the booster ignited by the initiator, and the communication between the first chamber and the initiator are always interrupted, and a sub-closure which is destroyed when the booster ignites is provided. 25. The hybrid inflator of claim 24, comprising a disc, wherein the booster agent and the secondary closure disc are located on the axis. 28. The hybrid inflator according to claim 24, wherein the pressurized medium is housed in the inflator housing so as to surround the gas generator housing. 29. The inflator housing includes a donut-shaped high-pressure gas housing, the gas generator housing has a substantially cylindrical shape, and the high-pressure gas housing is disposed around the gas generator housing. Item 29. The hybrid inflator according to Item 28. 30. The hybrid inflator according to claim 29, wherein a plurality of said bleeding ports are provided and are arranged radially with respect to said axis. 31. The first chamber and the second chamber are separated by a dome-shaped partition, and the ignition assembly is disposed inside the first chamber so as to be close to the partition, and the ignition assembly is provided. 30. The hybrid inflator according to claim 29, wherein the propellant is disposed around the inflator. 32. The partition according to claim 31, wherein the partition has a plurality of vents communicating the first chamber and the second chamber, and the vents are arranged obliquely with respect to the axis. Hybrid inflator. 33. The capacity of the inflator housing is about 50 cm ³ to about 150 cm ³ , and the capacity of the first chamber is about 5 c.
m ³ to about 15 cm ³ , and the volume of the second chamber is about 1 cm ³
Hybrid inflator according to claim 29 is about 20 cm ³ from. 34. The second chamber has a plurality of inlets for introducing the pressurized medium into the second chamber, each inlet being arranged to intersect a line extending radially from the axis. 30. The hybrid inflator according to claim 29, wherein: 35. In the second chamber, after the ignition assembly is activated, the pressure in the inflator housing exceeds the pressure in the gas generator housing by a predetermined amount.
35. The hybrid inflator of claim 34, comprising valve means operated in cooperation with said inlet to substantially block flow between the inflator housing and the gas generator housing through the inlet. 36. The inflator housing and the gas generator housing have a substantially cylindrical shape, the gas generator housing is housed in the inflator housing, and both ends of the inflator housing are connected to both ends of the gas generator housing. A hybrid inflator according to claim 28. 37. The hybrid inflator according to claim 36, wherein a plurality of said bleed ports are provided and are arranged radially with respect to said axis. 38. The aspirator nozzle according to claim 36, wherein an aspirator nozzle is provided between the first chamber and the second chamber, and the aspirator nozzle injects the propellant gas toward the main closing disk. Hybrid inflator. 39. The capacity of the inflator housing is set larger than the capacity of the second chamber.
9. The hybrid inflator according to 8. 40. The hybrid inflator according to claim 38, wherein the second chamber has an inlet near the aspirator nozzle for introducing the pressurized medium into the second chamber. 41. A portion of the inlet and the tip of the aspirator nozzle closest to the outlet is 4 mm from the outlet.
39. The hybrid inflator according to claim 38, wherein the hybrid inflator is 80mm apart from the. 42. In the second chamber, after the ignition assembly is actuated, the pressure in the inflator housing exceeds the pressure in the gas generator housing by a predetermined amount.
39. The hybrid inflator of claim 38, comprising valve means operated in cooperation with said inlet to substantially prevent flow between the inflator housing and the gas generator housing through the inlet. 43. The hybrid inflator according to claim 42, wherein said valve means is made of a flexible material and is disposed so as to surround said aspirator. 44. The first chamber includes a firing tube located on the axis within the first chamber, the tube being connected to the aspirator nozzle and communicating the interior of the tube with the first chamber. 39. The hybrid inflator of claim 38, comprising: 45. The capacity of the inflator housing is from about 150 cm ³ to about 450 cm ³ , and the capacity of the first chamber is about 1 cm.
0 cm ³ to about 40 cm ³ , and the capacity of the second chamber is about 1 c
hybrid inflator as claimed in claim 36 from m ³ is about 50 cm ^3.