JP2001263201A - Variable nozzle port type fuel injection nozzle for common rail - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable nozzle port type fuel injection nozzle for a common rail having a mechanism for controlling fuel injection by controlling a needle valve, being suitable for a fuel injection system having the common rail, requiring no enlargement of an actuator for controlling the fuel injection, capable of selecting the nozzle port cross-sectional area and capable of injecting spray suitable for a combustion state of an engine. SOLUTION: A rotary valve 27 has a selecting fuel passage 36 communicable with nozzle ports 22 and 23 by paying attention to the fact that the selecting fuel passage 36 of the rotary valve 27 varies the nozzle port cross-sectional area by selecting either of the nozzle ports 22 and 23 having a different nozzle port cross-sectional area and the needle valve 4 is driven for opening and closing by driving the rotary valve 27 in the shaft direction as a mechanism for controlling the fuel injection, and is featured in that the needle valve 4 can be driven by driving the rotary valve 27 in the shaft direction by a drive shaft 26 for rotating the rotary valve 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable injection hole type fuel injection nozzle for a common rail, in which high pressure fuel from a fuel accumulator (common rail) is atomized into a diesel engine or other internal combustion engine. More specifically, the present invention relates to a variable injection hole type fuel injection nozzle for a common rail that can make the injection hole cross-sectional area variable for each injection.

[0002]

2. Description of the Related Art Conventionally, there has been research and development of a variable injection hole type fuel injection nozzle for the purpose of promoting combustion in an internal combustion engine, improving output and fuel efficiency, and reducing combustion noise and nitrogen oxide (NOx) emission. Is being done. For example, in a fuel injection device disclosed in JP-A-59-18006, a tapered pressure receiving surface is formed at the tip of a needle valve slidably housed in a nozzle body, and a fuel pressure acts on the tapered pressure receiving surface. Then, the valve is opened, and a plurality of injection holes formed in multiple stages in the axial direction at the tip end portion of the nozzle body are selected to inject fuel. Also, Japanese Patent Application Laid-Open No. 4-7
As in the fuel injection nozzle disclosed in US Pat. No. 6,266,
A technology that opens the valve by applying fuel pressure to the pressure receiving surface of the needle valve, and adjusts the opening of the nozzle using a rotary valve to change the cross-sectional area of the nozzle. Are also being considered. Further, as in the variable injection hole type fuel injection nozzle disclosed in Japanese Patent Application Laid-Open No. 8-193560, a configuration in which a multistage injection hole can be selected by rotating a rotary valve is adopted. Some do.

However, what is conventionally developed is a so-called jerk type fuel injection nozzle in which fuel pressure is lifted by applying fuel pressure to a needle valve to perform fuel injection by opening an injection hole. However, this type of variable injection hole type fuel injection nozzle cannot be immediately applied to a common rail type fuel injection system. That is, in the common rail type fuel injection system, high pressure fuel accumulated in the common rail is always supplied to the fuel injection nozzle, and the needle valve is opened and closed by an actuator such as an electromagnetic valve. Although the injection pressure and the injection amount can be appropriately controlled, it is necessary to control the opening and closing of the needle valve, that is, perform the injection control. However, for example, when a fuel injection nozzle having an injection hole selection mechanism of the type described in Japanese Patent Application Laid-Open No. 8-193560 is considered to be mounted on a common rail type fuel injection system, a function of controlling fuel injection on the fuel injection nozzle side is provided. Therefore, it is necessary to incorporate a mechanism for performing fuel injection control inside the nozzle. That is, as the variable injection hole type fuel injection nozzle for the common rail type fuel injection system, it is necessary to develop a fuel injection nozzle having a function of controlling the fuel injection by driving the needle valve.

[0004] In particular, in a fuel injection nozzle for a diesel engine, the fuel pressure for injection is much higher than that in a gasoline engine.
If the actuator that drives and controls the lift of the needle valve in the common rail fuel injection system is a so-called direct-acting type that directly drives the needle valve, there is a problem that this actuator becomes large. Requires some ingenuity.

[0005] In particular, in a fuel injection nozzle for a diesel engine, it is necessary to inject high-pressure fuel. Therefore, in order to improve fuel efficiency, it is required that the internal fuel seal be good. .

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a variable injection hole fuel for a common rail suitable for a fuel injection system having an accumulator (common rail) for storing high-pressure fuel. It is an object to provide an injection nozzle.

Another object of the present invention is to provide a common rail variable injection hole type fuel injection nozzle having a mechanism for controlling the fuel injection by driving the needle valve.

Another object of the present invention is to provide a variable injection hole type fuel injection nozzle for a common rail in which an actuator for performing fuel injection control is not increased in size.

It is another object of the present invention to provide a variable injection hole type fuel injection nozzle for a common rail which can change or select the injection hole cross-sectional area and can inject a spray suitable for the combustion state of the engine.

It is another object of the present invention to provide a variable injection hole type fuel injection nozzle for a common rail with improved sealing performance.

[0011]

In other words, the present invention is to provide a fuel injection valve having a variable injection hole cross-sectional area by selecting one of a plurality of injection holes having different injection hole cross-sectional areas by a fuel passage for selecting a rotary valve. And a mechanism for performing fuel injection control, in which a rotary valve is driven in the axial direction thereof to open and close a needle valve, and the high-pressure fuel from a common rail storing high-pressure fuel is used. And a nozzle body having a nozzle hole and a jetting surface and a sheet surface connected to the nozzle hole,
A needle valve that is reciprocally movable within the nozzle body and that can inject the high-pressure fuel from the injection hole by lifting from the seat surface; and a rotary valve that changes the injection hole cross-sectional area of the injection hole. And a variable injection hole type fuel injection nozzle for a common rail, comprising: a plurality of injection holes each having a different injection hole cross-sectional area, wherein the rotary valve adjusts a relative position with respect to the injection hole. The fuel injection valve has a selectable fuel passage that is adjustable and can communicate with the injection hole. By rotating the rotary valve, an arbitrary injection hole is selected from the plurality of injection holes, and the selection is made to the injection hole. And a drive shaft for injecting the high-pressure fuel from the selected injection hole, and the drive shaft is used to remove the rotary valve. By driving the axial direction, a variable injection hole type fuel injection nozzle for a common rail, characterized in that to enable driving the needle valve.

A two-way valve capable of controlling the back pressure of the needle valve for receiving the high-pressure fuel from the common rail can be provided.

[0013] A rotary solenoid capable of rotating the rotary valve around its axis can be provided.

[0014] A linear solenoid capable of driving the drive shaft in the axial direction can be provided.

In the variable injection hole type fuel injection nozzle for the common rail according to the present invention, as a mechanism for controlling the fuel injection, a method of driving the needle valve to open and close by driving the rotary valve in the axial direction thereof is adopted.
When the high-pressure fuel is introduced by connecting to the common rail, the rotary valve itself for changing the injection hole cross-sectional area can be used for opening and closing control of the needle valve. Further, the lift operation of the needle valve in the nozzle body to which high-pressure fuel is supplied can be controlled by a smaller actuator via the rotary valve. Furthermore, since the fuel passage for selection of the rotary valve selects one of a plurality of injection holes having different injection hole cross-sectional areas, the injection hole cross-sectional area is made variable, so that injection is performed without changing the injection hole cross-sectional shape itself. By properly adjusting the injection pressure, the injection amount, and the like during the period, the spray suitable for the combustion state of the engine can be injected.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a variable injection hole type fuel injection nozzle 1 for a common rail according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a common rail variable injection hole type fuel injection nozzle 1. The common rail variable injection hole type fuel injection nozzle 1 includes a nozzle housing 2, a nozzle body 3, a needle valve 4, and an injection hole. It has a selection mechanism 5, an injection control mechanism 6, and a control circuit 7.

The nozzle housing 2 includes a common rail side housing 8 and a linear solenoid housing 9 (first
), A rotary solenoid housing 10 (second solenoid housing), and a distance piece 11. High-pressure fuel is stored in the common rail 14 (accumulator) from the fuel tank 12 via the fuel pump 13, and high-pressure fuel can be supplied to the fuel inlet 15 formed in the common rail side housing 8. A fuel passage 16 is formed from the fuel inlet 15 to the nozzle housing 2 and the nozzle body 3, and a pressure in a lift direction can be applied to a pressure receiving portion 18 of the needle valve 4 in a fuel storage chamber 17 in the nozzle body 3. 17 to a hole 19 at the tip of the nozzle body 3 (FIG. 4).

The nozzle body 3 includes the retaining nut 2
This is fixed to the nozzle housing 2 by 0, and its front end faces the combustion chamber 21. At the tip of the nozzle body 3, a plurality of injection holes (small diameter injection holes 22 and large diameter injection holes 23) having two different types of injection hole cross-sectional areas (in particular, FIG.
And FIG. 6). The small-diameter injection holes 22 and the large-diameter injection holes 23 are formed alternately, for example, at intervals of 45 degrees, for example, four each.

The needle valve 4 is provided in the nozzle body 3 so as to be able to reciprocate. That is, the needle valve 4 is slidable between the nozzle body 3 and the inner wall surface 3A on the upstream side of the fuel reservoir through the first clearance seal portion 24, and between the needle valve 4 and the inner wall surface 3B on the downstream side of the fuel reservoir. Fuel passage 16
This can be reciprocated in the axial direction.

FIG. 2 is an enlarged cross-sectional view of a main part showing the tip portion of the nozzle body 3, the injection hole selection mechanism 5 and the injection control mechanism 6 in the variable injection hole type fuel injection nozzle 1 for the common rail. The injection control mechanism 6 controls the opening and closing of the injection holes (small-diameter injection holes 22 and large-diameter injection holes 23) by driving the needle valve 4 in the axial direction thereof, and controls the linear solenoid 25 (the first solenoid valve 25). Solenoid, drive shaft 26, rotary valve 27, two-way valve 28, shaft spring 29, needle valve spring 30
And The injection hole selection mechanism 5 includes a rotary solenoid 31 (second solenoid), the drive shaft 26 and the rotary valve 27.

FIG. 3 is an enlarged perspective view of the rotary valve 27, and FIG. 4 is an enlarged sectional view of a main part of the injection hole selection mechanism 5 in a state where the rotary valve 27 is seated in the hole 19 and the needle valve 4 is lifted. 5 is a cross-sectional view taken along the line VV of FIG. 2, and FIG. 6 is a cross-sectional view similar to FIG. 5, in which a rotary valve 27 is integrally formed at the tip of the drive shaft 26, as shown in FIG. I have.

In particular, as shown in FIG.
The fuel passage 16 from the fuel inlet 15 and the small-diameter injection holes 22 and the large-diameter injection holes 22 and the large-diameter injection holes The diameter injection hole 23 can be shut off and opened. The seat part 32 and the seat surface 33 form a first mechanical seal part 34. When the needle valve 4 lifts from the seat surface 33 against the urging force of the needle valve spring 30 (FIG. 2), high-pressure fuel is supplied from the small-diameter injection hole 22 or the large-diameter injection hole 23 to the combustion chamber 2.
Injection into 1 is possible.

As shown in FIGS. 3 and 4, the rotary valve 27 is formed in a conical shape so that the conical seat portion 35 can also seat in the conical concave hole 19 and its circumferential direction. The selection fuel passages 36 are formed at equal angular intervals (90-degree intervals) in the
6 can communicate with the small diameter injection hole 22 or the large diameter injection hole 23.

The drive shaft 26 has a sealing bulge 37 at the base end side (upper side in FIG. 4) of the rotary valve 27.
To form a second clearance seal portion 38 between the needle valve 4 and the inner wall surface 4A. A pressure switching passage portion 39 is provided between the inner wall surface 4A of the needle valve 4 and the upstream side of the seal expanding portion 37 in the drive shaft 26.

The configuration of the rotary valve 27 includes the fuel passage 16 and the small-diameter injection hole 22 or the large-diameter injection hole 23.
Any configuration other than the configuration shown in FIG. For example, in a rotary valve 40 shown in FIG. 7, a selection fuel passage 41 is formed in parallel along a conical seat portion 35. FIG.
The rotary valve 42 shown in FIG.
The introduction hole 43 formed in the upper surface of the sheet and the selection hole 44 formed in the conical sheet portion 35 can communicate with each other.

As shown in FIGS. 1 and 2, the linear solenoid 25 (first solenoid) drives the drive shaft 26 and the rotary valve 27 in the axial direction thereof. The head 47 of the drive shaft 26 is attracted to the armature 48 against the biasing force of the shaft spring 29 interposed between the spring seat portion 46 and the armature 48. When the head 47 of the drive shaft 26 is sucked by the armature 48, the drive shaft 26 and thus the rotary valve 27 are lifted in the direction of the hole 19 by the shaft lift amount L1 (FIGS. 1 and 2), as shown in FIG. The rotary valve 27 moves toward the hole 19 by the shaft lift amount L1 and seats in the hole 19. As will be described later with reference to FIGS. 9 and 10, the rotary valve 27 seats in the hole 19,
The two-way valve 28 in the injection control mechanism 6 switches, and the needle valve 4 is lifted.

The rotary solenoid 31 (second solenoid) drives the drive shaft 26 and thus the rotary valve 27 to rotate about its axis, as shown in FIGS. 1 and 2, and a flange member 45 of the drive shaft 26. Via the magnet 49 fixed to
Normally, at the time of an exhaust process or an intake process in the combustion chamber 21 of the engine, the drive shaft 26 is rotated by a predetermined circumferential angle, and the fuel passage 36 for selection in the rotary valve 27 and the small-diameter injection hole 22 or the large-diameter The relative position with respect to the injection hole 23 is controlled and adjusted. For example, as shown in FIG. 5, the selection fuel passage 36 faces the small-diameter injection hole 22, or as shown in FIG. The operator operates whether the fuel passage 36 is exposed. In addition,
If the driving force of the rotary solenoid 31 is set to be sufficiently large, the relative position between the rotary valve 27 and the small-diameter injection hole 22 or the large-diameter injection hole 23 can be increased even in the compression process or the combustion process in which the combustion chamber 21 is in a high pressure state. Position control adjustment operation is possible. FIG. 5 shows a state in which a suitable spray can be ejected at high load and low rotation. FIG. 6 shows a state in which a suitable spray can be ejected at low load and high rotation. In either case shown in FIGS. 5 and 6, the selection fuel passage 36
By rotating and selecting the small-diameter injection hole 22 and the large-diameter injection hole 23 so that they are completely located inside the passage,
Injection can be performed while maintaining the normally circular cross-sectional shape of the small-diameter injection hole 22 and the large-diameter injection hole 23, and the shape and direction of the spray can be normally maintained.

FIGS. 9 and 10 are cross-sectional views of the main part of the two-way valve 28, showing a partly omitted configuration. FIG. 9 is a cross-sectional view of the non-injection state in which the needle valve 4 does not perform injection in a seat state. ,
FIG. 10 is a cross-sectional view of an injection state in which the needle valve 4 lifts and performs injection similarly to FIG. As shown in FIGS. 2, 9, and 10, in the two-way valve 28, a pressure chamber 51 is formed at the top of the needle valve 4 through an introduction orifice 50 branched from the fuel passage 16, and the pressure chamber 51 is formed. To the spring chamber 52 of the needle valve spring 30.
Is formed. The pressure chamber 51 and the spring chamber 5
Reference numeral 2 denotes a back pressure of the needle valve 4, and a pressure switching passage portion 3 between the inner wall surface 4 </ b> A of the needle valve 4 and the upstream side of the seal expanding portion 37 in the drive shaft 26.
9 is always in communication. The first clearance seal portion 24 (see FIGS. 1 and 2) is provided between the nozzle body 3 and the needle valve 4 and the pressure chamber 51 and the needle valve 4.
Is sealed with the fuel storage chamber 17 facing the pressure receiving portion 18. Further, the second clearance seal portion 3
Reference numeral 8 (see FIG. 4) seals between the pressure chamber 51 and the injection holes (the small-diameter injection holes 22 and the large-diameter injection holes 23) between the needle valve 4 and the valve body 3.

Along the axial direction of the drive shaft 26,
Further, a seal chamber 53 is formed in communication with the spring chamber 52. A movable seal member 54 attached to the drive shaft 26 and a fixed seal member 56 attached to the sleeve 55 of the spring seat portion 46 are provided in the seal chamber 53.
And are provided. Fixed seal member 56 and movable seal member 5
4, the second mechanical seal portion 57 is formed.
An O-ring 58 is arranged between the fixed seal member 56 and the spring seat 46 and the sleeve 55.

The fixed seal member 56 and the drive shaft 2
There is a low-pressure outlet orifice 59 between the valve spring 6 and the fuel tank 6 at a low pressure side (the fuel tank 12 side) through the spring chamber 60 of the shaft spring 29 and the return passage 61. That is, the second mechanical seal portion 57
The pressure chamber 5 is driven by the drive shaft 26.
Open and close between 1 and low pressure side. The characteristics of the two-way valve 28 mainly depend on the inlet orifice 50 and the outlet orifice 59.
This can be determined by the ratio of the cross-sectional areas of

The control circuit 7 (FIG. 1), based on signals from the load sensor 62 and the rotation speed sensor 63,
The drive control of the linear solenoid 25 (injection control mechanism 6) and the rotary solenoid 31 (injection hole selection mechanism 5) is performed.

In the common rail variable injection hole type fuel injection nozzle 1 having such a configuration, when the inside of the combustion chamber 21 is in a relatively low pressure state, that is, in the exhaust process or the intake process of the engine, the rotary solenoid 31 in the injection hole selection mechanism 5 is used. Is driven to rotate the drive shaft 26 around the axis by a predetermined circumferential angle, so that the selection fuel passage 36 in the rotary valve 27 at the tip of the drive shaft 26 and the small-diameter injection hole in the hole 19 of the nozzle body 3 The state shown in FIG. 5 or FIG. 6 is selected by operating the relative positional relationship with the nozzle 22 or the large-diameter injection hole 23.

The operation of the two-way valve 28 in the injection control mechanism 6 will be described below. In a normal non-injection state, FIG.
2, the head 47 of the drive shaft 26 is pulled upward in FIG. 2 by the urging force of the shaft spring 29 (FIG. 2), and the conical seat portion 35 of the rotary valve 27 is moved from the inner wall surface of the hole 19. The needle valve 4 is seated on the seat surface 33 by the high pressure fuel in the pressure chamber 51 and the spring chamber 52 and the urging force of the needle valve spring 30 because the needle valve 4 is axially separated by the shaft lift amount L1. That is, the pressure chamber 5
1 and the pressure receiving area 51S of the needle valve 4 in the spring chamber 52 (the area obtained by subtracting the diameter of the drive shaft 26 from the diameter of the needle valve 4) corresponds to the seat portion 32 of the needle valve 4 on the seat surface 33 of the nozzle body 3. The pressure receiving area 32S (from the diameter of the needle valve 4 its seat portion 32)
And the urging force of the needle valve spring 30 is applied.
This means that even if both the top facing the pressure chamber 51 and the lower end seating on the seat surface 33 are filled with high-pressure fuel, the seat portion 32 will seat on the seat surface 33. Since the second mechanical seal portion 57 of the seal chamber 53 communicating with the spring chamber 52 by the movable seal member 54 and the fixed seal member 56 is in a closed state, the seal chamber 53 is also in a high-pressure state.

Accordingly, the pressure chamber 51 and the spring chamber 52 are in a high pressure state together with the seal chamber 53 and the pressure switching passage section 39 from the introduction orifice 50 together with the fuel passage 16 in the high pressure state. When the sheet portion 32 is seated on the sheet surface 33, the small-diameter injection hole 22 or the large-diameter injection hole 23 is not opened, and there is no injection. The periphery of the rotary valve 27 from the seat portion 32 of the needle valve 4 and the expanding portion 37 for sealing of the drive shaft 26 to the injection holes (small diameter injection holes 22 and large diameter injection holes 23) is in a low pressure state. The orifice 59 and the shaft spring 2 are separated by a second mechanical seal 57.
The spring chamber 60 of No. 9 also communicates with the fuel tank 12 via the return passage 61 (FIG. 1) and is in a low pressure state.

The fuel passage 3 for selecting the rotary valve 27
After the communication state between the small diameter injection hole 22 and the large diameter injection hole 22 or the large diameter injection hole 23 is determined, the linear solenoid 25 in the injection control mechanism 6 is driven to thereby rotate the shaft spring 2.
When the armature 48 sucks the head 47 of the drive shaft 26 against the urging force of the rotary shaft 9, the conical seat portion 35 of the rotary valve 27 as shown in FIGS.
Seats in the hole 19 and the movable seal member 5
4 is separated from the fixed seal member 56, the second mechanical seal portion 57 is opened, and the two-way valve 28 is switched. That is, as shown in FIG. 10 in particular, when the second mechanical seal portion 57 is opened, the pressure chamber 51, the spring chamber 52, the seal chamber 53, and the pressure switching passage 39 are formed by the outlet orifice 59 and the spring chamber. 6
It switches to a low pressure state close to the atmospheric pressure level by communicating with zero. Therefore, the pressure balance in the two-way valve 28 switches, and the needle valve 4 receives the high pressure from the fuel passage 16 and the fuel storage chamber 17 by the pressure receiving portion 18, and the seat surface 3
3 (lift amount L2, FIG. 10);
The 2 or large diameter injection hole 23 can be opened to inject into the combustion chamber 21.

To terminate fuel injection, the linear solenoid 25 is turned off. This "off"
Energizing drive shaft 26 of shaft spring 29
And the rotary valve 27 rises from the state of FIG. 10, the second mechanical seal portion 57 is closed, and the communication state between the lead-out orifice 59 and the seal chamber 53 is cut off.
The pressures in the seal chamber 53, the spring chamber 52, the pressure chamber 51, and the pressure switching passage 39 are increased again, and the needle valve 4 is lowered to the state shown in FIG.

Thus, the needle valve 4 is driven in the axial direction by the vertical movement of the drive shaft 26 and the rotary valve 27 in the injection control mechanism 6 in the axial direction to open and close the small diameter injection hole 22 or the large diameter injection hole 23. The drive shaft 26 and the rotary valve 27 in the injection hole selection mechanism 5 rotate to select either the small-diameter injection hole 22 or the large-diameter injection hole 23 to change the cross-sectional area of the injection hole. Suitable spray can be injected.

Further, the two-way valve 28 itself is disposed as close to the needle valve 4 as possible, and the base end (pressure chamber 51) and the tip end of the needle valve 4 and the portion close to the rotary valve 27 (a large portion for sealing) (Around 37), switching between high pressure and low pressure is performed, so that responsiveness is good. That is, the first clearance seal portion 24 (FIG. 2) slidable between the needle valve 4 and the inner wall surface 3A of the nozzle body 3 on the upstream side of the fuel storage chamber, and the sealing enlarged portion 37 of the rotary valve 27 and the needle The slidable second clearance seal portion 38 (FIGS. 4, 9, and 10) slidable between the inner wall surface 4A and the valve 4 has good sealing properties and responsiveness, and reduces the amount of leaking fuel. As a result, fuel efficiency can be improved. Further, the first mechanical seal portion 34 (FIGS. 4 and 9) between the seat portion 32 of the needle valve 4 and the seat surface 33 of the nozzle body 3, and between the fixed seal member 56 and the movable seal member 54. Since the switching between high pressure and low pressure is performed in the second mechanical seal portion 57 (FIGS. 9 and 10), the responsiveness can be improved and the amount of leaking fuel can be reduced.

Further, the actuators (the linear solenoid 25 and the rotary solenoid 31) for driving the needle valve 4 and the rotary valve 27 do not need to be so large, so that a compact structure can be achieved, and as described above, a favorable configuration can be obtained. Response can be obtained, so that pilot injection or the like can be performed if necessary.

[0040]

As described above, according to the present invention, the lift state of the needle valve can be realized by driving the rotary valve in the axial direction of the variable injection hole type fuel injection nozzle for the common rail connected to the common rail. Therefore, taking advantage of the characteristics of the common rail and the variable injection hole type fuel injection nozzle with variable injection hole cross-sectional area
Since the spray characteristics can be freely changed, it can greatly contribute to improving the performance of the engine. further,
Since the sealing mechanism is provided in the vicinity of the needle valve having good sealing performance, sealing performance and responsiveness can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a common rail variable injection hole type fuel injection nozzle 1 according to an embodiment of the present invention.

FIG. 2 shows the tip portion of a nozzle body 3 of a variable injection hole type fuel injection nozzle 1 for a common rail, an injection hole selection mechanism 5,
FIG. 4 is an enlarged cross-sectional view of a main part showing a part of an injection control mechanism 6;

FIG. 3 is an enlarged perspective view of the rotary valve 27;

FIG. 4 is an enlarged sectional view of a main part of the injection hole selection mechanism 5 in a state where the rotary valve 27 seats in the hole 19 and the needle valve 4 is lifted.

FIG. 5 is a sectional view taken along line VV of FIG. 2;

FIG. 6 is a sectional view similar to FIG. 5;

FIG. 7 is a perspective view of a rotary valve 40 according to another example of the present invention.

FIG. 8 is a perspective view of a rotary valve 42 according to another example of the present invention.

FIG. 9 is a cross-sectional view of an essential part showing a configuration of the two-way valve 28 in a non-injection state in which the needle valve 4 does not perform injection in a seat state.

FIG. 10 is a cross-sectional view of the main part of the two-way valve 28, showing the configuration of the two-way valve 28, similar to FIG. 4, in an injection state in which the needle valve 4 lifts and performs injection.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Variable injection hole type fuel injection nozzle for common rails (Embodiment, FIG. 1) 2 Nozzle housing 3 Nozzle body 3A Inner wall surface of fuel accumulation chamber upstream of nozzle body 3 (FIG. 2) 3B Downstream of fuel accumulation chamber of nozzle body 3 Inner wall surface (FIG. 2) 4 Needle valve 4A Inner wall surface of needle valve 4 (FIGS. 2 and 4) 5 Injection hole selection mechanism 6 Injection control mechanism 7 Control circuit 8 Common rail side housing of nozzle housing 2 9 Linear solenoid of nozzle housing 2 Housing 10 Rotary solenoid housing of nozzle housing 2 11 Distance piece of nozzle housing 2 12 Fuel tank 13 Fuel pump 14 Common rail (pressure accumulator) 15 Fuel inlet 16 Fuel passage 17 Fuel reservoir 18 Pressure receiving portion of needle valve 4 19 Nozzle body 3 Hall 20 Retaining Unit 21 Combustion chamber 22 Small diameter injection hole (injection hole) 23 Large diameter injection hole (injection hole) 24 First clearance seal portion 25 Linear solenoid (first solenoid) 26 Drive shaft 27 Rotary valve 28 Two-way valve 29 Shaft Spring 30 Needle valve spring 31 Rotary solenoid (second solenoid) 32 Seat portion of needle valve 4 32S Pressure receiving area of seat portion 32 of needle valve 4 on seat surface 33 of nozzle body 3 (32S <51S, FIGS. 2, 9) 33) Seat surface of nozzle body 3 34 First mechanical seal portion 35 Conical seat portion of rotary valve 27 36 Fuel passage for selecting rotary valve 27 37 Enlarged portion for sealing drive shaft 26 38 Second clearance seal portion 39 Pressure switching passage 40 Rotor -Valve (Fig. 7) 41 Fuel passage for selection 42 Rotary valve (Fig. 8) 43 Inlet hole 44 Selection hole 45 Flange member of drive shaft 26 46 Spring seat portion 47 Head of drive shaft 26 48 Armature 49 Magnet 50 Introduction Orifice 51 Pressure chamber 51S Pressure receiving area of needle valve 4 in pressure chamber 51 and spring chamber 52 (32S <51S, FIG. 2) 52 Spring chamber of needle valve spring 30 Seal chamber 54 Movable seal member 55 Sleeve of spring seat part 56 Fixed seal member 57 Second mechanical seal portion 58 O-ring 59 Outgoing orifice 60 Spring chamber of shaft spring 29 61 Recirculation passage 62 Load sensor 63 Speed sensor L1 Drive shaft 26 (rotary) Valve 27)
Lift amount of shaft (FIGS. 1 and 2) Lift amount of L2 needle valve 4 (FIG. 10)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) F02M 47/02 F02M 47/02 51/00 51/00 F 61/10 61/10 G 61/18 330 61 / 18 330C 61/20 61/20 NF term (reference) 3G066 AA07 AB02 AC09 AD12 BA12 BA19 BA36 BA67 CB01 CC05U CC06T CC06U CC08T CC14 CC18 CC20 CC23 CC26 CC30 CC66 CC67 CC68U CC70 CD10 CE13 CE22 DB08 DB09 DC01 DC09

Claims (4)

[Claims] 1. A nozzle body having an injection hole and a seat surface connected to the injection hole, receiving a supply of the high-pressure fuel from a common rail storing the high-pressure fuel, and a reciprocatingly provided nozzle body in the nozzle body. A variable injection hole fuel for a common rail, comprising: a needle valve that can inject the high-pressure fuel from the injection hole by lifting from the seat surface; and a rotary valve that changes the injection hole cross-sectional area of the injection hole. An injection nozzle, wherein the injection hole is a plurality of injection holes having different injection hole cross-sectional areas, and the rotary valve is capable of adjusting a relative position with respect to the injection hole and communicating with the injection hole. A fuel passage for selection, and by rotating the rotary valve, an arbitrary injection hole is selected from the plurality of injection holes, and the fuel for selection is supplied to the injection hole. A drive shaft that allows the high-pressure fuel to be injected from the selected injection hole is provided facing the path, and the needle valve can be driven by driving the rotary valve in the axial direction with the drive shaft. A variable injection hole type fuel injection nozzle for a common rail. 2. The fuel injection nozzle according to claim 1, further comprising a two-way valve capable of controlling a back pressure of the needle valve for receiving high-pressure fuel from the common rail. 3. The fuel injection nozzle according to claim 1, wherein a rotary solenoid is provided for rotating the rotary valve around its axis. 4. The fuel injection nozzle according to claim 1, further comprising a linear solenoid capable of driving the drive shaft in the axial direction.