JPH0789423A - Anti-lock brake device for vehicle - Google Patents

Abstract

PURPOSE:To make possible brake pressure reducing control according to body deceleration by providing variable orifices which increase the degree of restriction according to increase of the car body deceleration between normally-closed solenoid valves and reservoirs. CONSTITUTION:When a brake fluid pressure is decreased immediately before a wheel lock is started to be produced, a corresponding solenoid valve among normally-closed type solenoid valves VCFL to VCRL is energized to open a valve. Since variable orifices 19FL, 19FR, 19RL, and 19RR are provided between the normally-closed solenoid valves VCFL, VCFR, VCRL, and VCRR and reservoirs R1 and R2, respectively, the releasing rate of the brake fluid from wheel brakes BFL to BRL is limited by the variable orifices 19FL, 19FR, 19RL, and 19RR. Also the degree of restriction of the variable orifices 19FL, 19FR, 19RL, and 19RR is increased according to increase of body deceleration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a normally open solenoid valve provided between a master cylinder and a wheel brake, a reservoir, and a normally closed solenoid valve provided between the reservoir and the wheel brake. The present invention relates to an antilock brake device for a vehicle, comprising a return pump having an intake port connected to the reservoir, and a damper connected between a normally open solenoid valve and a master cylinder and having a discharge port connected to the return pump.

[0002]

2. Description of the Related Art An anti-lock brake device, in which an anti-lock brake control is performed by selectively switching a wheel brake between a master cylinder and a reservoir and adjusting a brake pressure of the wheel brake, is disclosed in, for example, Japanese Patent Laid-Open No. Sho 60. It is already known from, for example, Japanese Patent Publication No. 33158.

[0003]

In such a device, the friction coefficient of the road surface is relatively high when the anti-lock brake control is executed in response to the possibility that the wheels will be locked during the brake operation. When the deceleration is relatively high, it is desirable to gently reduce the brake pressure, whereas when the vehicle road surface has a relatively low friction coefficient and the vehicle deceleration is relatively low, the brake pressure is quickly reduced. It is desirable to do. However, in the above-mentioned conventional one, the electromagnetic directional control valve is connected by connecting the throttle having a constant throttle degree in series to the electromagnetic switch control valve for selectively switching the wheel brake to the master cylinder and the reservoir. Although the hydraulic pressure control is performed smoothly by avoiding a sudden hydraulic pressure exerted on the wheel brakes due to the changeover, the brake pressure reduction control according to the vehicle deceleration is not considered.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an antilock brake device for a vehicle capable of controlling the brake pressure reduction according to the vehicle deceleration.

[0005]

In order to achieve the above object, the invention according to claim 1 is a normally open solenoid valve interposed between a master cylinder and a wheel brake, and a reservoir.
A normally closed solenoid valve provided between the reservoir and the wheel brake, a return pump having an inlet connected to the reservoir, and a discharge valve of the return pump connected between the normally open solenoid valve and the master cylinder. In a vehicle anti-lock brake device including a damper to which an outlet is connected, a variable orifice that increases the degree of throttling in accordance with a large vehicle deceleration is provided between a normally closed solenoid valve and a reservoir. It is characterized by being done.

According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, the normally open solenoid valve is
The orifices are connected in parallel.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an antilock brake device for a four-wheel vehicle will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention, FIG. 1 is a hydraulic circuit diagram of an antilock brake device for a vehicle, and FIG. 2 is an enlarged vertical sectional view of a normally open solenoid valve. Figure 3
FIG. 3 is an enlarged vertical sectional view of a normally closed solenoid valve.

First, in FIG. 1, the tandem type master cylinder M is provided with a pair of output ports 12 and 13 for outputting a braking fluid pressure according to the depression of the brake pedal 11, and the left front wheel brake B _FL and the right rear wheel. A proportional pressure reducing valve 14 _R connected to the brake B _RR , a right front wheel brake B _FR , and a proportional pressure reducing valve 14 _L connected to the left rear wheel brake B _RL ,
An antilock brake device 15 is provided between the output ports 12 and 13.

The anti-lock brake device 15 includes four _normally open solenoid valves V _OFL individually corresponding to the left front wheel brake B _FL , the right rear wheel brake B _RR , the right front wheel brake B _FR and the left rear wheel brake B _RL. , V _ORR , V _OFR , V _ORL and four check valves 17 _FL , 17 _RR , 17 _FR , 17 connected in parallel to the _normally open solenoid valves V _{OFL to} V _ORL , respectively.
_RL and four orifices 18 _FL , 18 _RR , 18 _FR , which are connected in parallel to the _normally open solenoid valves V _{OFL to} V _ORL , respectively.
18 _RL and four normally closed solenoid valves V _CFL , V _CRR , V _CFR and V individually corresponding to the wheel brakes B _{FL to} B _RL.
CRL , left front wheel brake B _FL and right rear wheel brake B _RR
Side and right front wheel brake B _FR and left rear wheel brake B
A pair of reservoirs R ₁ and R individually corresponding to the _RL side
₂ , normally closed solenoid valves V _CFL , V _CRR and reservoir R ₁
And the normally closed solenoid valves V _CFR , V _CRL and the reservoir R ₂ respectively, with variable orifices 19 _FL , 1
9 _RR , 19 _FR and 19 _RL , a pair of return pumps 21 ₁ and 21 ₂ connected to both reservoirs R ₁ and R ₂ via suction valves 20 ₁ and 20 ₂ , and both return pumps 21 ₁ and 21 ₂ , A pair of dampers D ₁ connected to both return pumps 21 ₁ and 21 ₂ via discharge valves 23 ₁ and 23 ₂ .
D ₂ and the output ports 12, 13 of the master cylinder M
And orifices 25 ₁ and 25 ₂ provided between the dampers D ₁ and D ₂ , respectively.

The _normally open solenoid valve V _OFL is a master cylinder M.
The _normally open solenoid valve V _ORR is provided between the one output port 12 and the left front wheel brake B _FL, and
And a proportional pressure reducing valve 14 _R connected to the right rear wheel brake B _RR , the _normally open solenoid valve V _OFR is provided between the other output port 13 of the master cylinder M and the right front wheel brake B _FR . The normally open solenoid valve V _ORL is interposed between the proportional pressure reducing valve 14 connected to the output port 13 and the left rear wheel brake B _RL.
It is installed between _L and. Check valves 17 _{FL to} 17 _{RL
Are the} normally open solenoid valves V _{OFL to} V so that only the flow of hydraulic fluid from the corresponding wheel brakes B _{FL to} B _RL is allowed.
Connected in parallel to the _ORL .

Normally closed solenoid valve V_CFLLeft front wheel brake B_FL
And reservoir R₁Variable orifice 19 connected to_FLWith
In between, a normally closed solenoid valve V_CRRIs the proportional pressure reducing valve 14_RAnd lizard
Bar R ₁Variable orifice 19 connected to_RRAnd always
Closed solenoid valve V_CFRRight front wheel brake B_FRAnd reservoir R₂
Variable orifice 19 connected to_FRBetween and again closed
Type solenoid valve V_CRLIs the proportional pressure reducing valve 14_LAnd reservoir R₂Contact
Variable orifice 19 continued_RLAnd are respectively installed between
Be done.

Such an antilock brake device 15
According to the above, during normal braking in which each wheel is not likely to be locked, each normally open solenoid valve V _{OFL to} V _ORL is in a demagnetized state and is open, and each normally closed solenoid valve V _CFL. ~
V _CRL is demagnetized and is closed. Therefore, the braking fluid pressure output from one output port 12 of the master cylinder M acts on the left front wheel brake B _FL via the _normally open solenoid valve V _OFL , and at the same time, the _normally open solenoid valve V _ORR and the proportional pressure reducing valve 14 are provided. It acts on the right rear wheel brake B _RR via _R ,
The braking fluid pressure output from the other output port 13 of the master cylinder M acts on the right front wheel brake B _FR via the _normally open solenoid valve V _OFR, and at the same time, the _normally open solenoid valve V _ORL and the proportional pressure reducing valve 14 are provided. It acts on the left rear wheel brake B _RL via _L.

At the time of anti-lock control when the wheel is about to enter the locked state during braking, the normally open type solenoid valve corresponding to the wheel that is about to enter the locked state among the _normally open solenoid valves V _{OFL to} V _ORL. Is excited to close the valve, and at the same time, of the normally closed solenoid valves V _{CFL to} V _CRL , the normally closed solenoid valves corresponding to the wheels are excited and opened. Then, a part of the brake fluid pressure is released to the reservoir R ₁ or R ₂ and reduced. When the brake fluid pressure is maintained, the normally open solenoid valves V _{OFL to} V _ORL are excited to close the valve, and the normally closed solenoid valves V _{CFL to} V _CRL are demagnetized to maintain the closed state. Of course, when increasing the braking fluid pressure, deenergize the normally open solenoid valves V _{OFL to} V _ORL and open them, and demagnetize the normally closed solenoid valves V _{CFL to} V _CRL to keep them closed. Good.

Thus, the pair of return pumps 21₁, 21₂To
The motor 22 that is commonly driven is used during the above antilock control.
Is operated by the reservoir R₁, R₂To
The released hydraulic fluid is returned to the pump 21₁, 21₂From Dan
PA D₁, D₂And orifice 25₁, 25₂Through each
Normally open solenoid valve V_OFL~ V_ORLIs returned to the upstream side of. did
Reservoir R₁, R₂Master Siri only as much as you missed
Increases the depression amount of the brake pedal 11
There is no such thing, and the return pump 21₁, 21 ₂Sent from
The pulsation of the hydraulic fluid that is discharged is damper D₁, D₂And Oriff
25₁, 25₂Is attenuated by the action of
No pulsation is transmitted to the key pedal 11.

Demagnetization / excitation of the normally open solenoid valves V _{OFL to} V _ORL and the normally closed solenoid valves V _{CFL to} V _CRL is controlled by an electronic control unit (hereinafter referred to as ECU) 26. The ECU 26 includes wheel speed sensors 27 _FL , 27 _RR , 27 for individually detecting the wheel speed of each wheel in order to determine whether or not the wheel is about to enter a locked state.
The detection signals of _FR and 27 _RL are input, and the detection signal of the handbrake detection sensor 29 that detects whether or not the handbrake lever 28 is operated is input, and further activated by the ECU 26 when in the antilock control state. A notification device 30 such as a lamp is connected to the ECU 26.

The antilock brake device 15 is a block
It is provided with a metal base 34 formed in a square shape.
The base 34 has four normally open solenoid valves V_OFL, V
_ORR, V _OFR, V_ORLFour normally closed solenoid valves V_CFL, V
_CRR, V_CFR, V_CRL, Check valve 17_FL, 17_RR, 1
7_FR, 17_RL, Orifice 18_FL, 18_RR, 18_FR, 1
8 _RL, Variable orifice 19_FL, 19_RR, 19_FR, 1
9_RL, Intake valve 20₁, 20₂, Return pump 21₁, 21
₂, Motor 22, discharge valve 23₁, 23₂And Orifice
Space 25₁, 25₂Are respectively arranged.

Each of the normally open solenoid valves V _OFL , V _ORR , V _OFR ,
The V _ORL has basically the same configuration, and the normally closed solenoid valves V _CFL , V _CRR , V _CFR , and V _CRL have basically the same configuration. Type solenoid valve V
_OFL , V _ORR , V _OFR , and V _ORL are normally open solenoid valves V _OFL , and normally closed solenoid valves V _CFL , V _CRR , and V _CF.
The detailed configuration of _R and V _CRL will be described using a normally closed solenoid valve V _CFL .

In FIG. 2, in the normally open solenoid valve V _OFL , the base end of the bottomed cylindrical guide cylinder 35 _O is the valve housing 36 _O.
37 _O and a guide tube 35 _O
Fixed core 38 _O fixed to the base end side of the fixed core 38
_The movable core 39 is spring-biased in a direction away from _O and is housed in the guide cylinder 35 _O , and is continuously connected to the movable core 39 so that it can be seated on the valve seat 40 provided in the valve housing 37 _O. a valve body 41, a coil 43 which is wound around the bobbin 42 surrounding the guide tube 35 _O, and a yoke 44 that magnetically couples the ends of the guide tube 35 _O over a portion of the coil 43 Prepare

The valve housing 36 _O is formed by caulking a bottomed cylindrical body 45 made of magnetic metal and a valve housing main body 46 _O partially fitted in the bottomed cylindrical body 45. The outer surface shape is formed into a stepped cylindrical shape. Moreover, a valve chamber 47 is formed between the valve housing main body 46 _O and the bottomed cylindrical body 45. The guide tube 35 _O is made of a magnetic metal through a cylindrical portion 45 b integrally provided on the bottomed cylindrical body 45 via a step portion 45 a and a non-magnetic portion 48 formed in a cylindrical shape by a non-magnetic material. The bottomed cylindrical portion 49 is coaxially connected in series. Therefore, the housing 37 _O is formed by coaxially connecting the valve housing 36 _O with the base end of the guide cylinder 35 _O via the step portion 45 a.

The valve housing 36_OIs one of the base 34
Fitting recess 50 provided on the surface 34a _OAnd the step 45
a is substantially flush with one surface 34a of the base 34
Mated. This fitting recess 50_OIs the valve housing 36
_OLarge-diameter portion 50 for fitting the bottomed cylindrical body 45 of_OAAnd
Housing subject 46_OSmall diameter part 50 for fitting_OBAnd step
It has a cylindrical body with a bottom.
A large diameter portion 50 is provided on the outer surface of 45._OAA ring that elastically contacts the inner surface of the
The large-diameter portion 50 while the seal member 51 of FIG._OAof
An annular filter 52 mounted between the inner surface and the inner surface is mounted.
The valve housing main body 46_O50 on the outer surface of_OBof
An annular seal member 53 that elastically contacts the outer surface _OIs installed
It

On the other hand, the base 34 is provided with a passage 54 that opens at a position eccentric to the inner end closed portion of the fitting recess 50 _O and a passage 56 that communicates with the valve chamber 47 via the filter 52. As shown in FIG. 1, the passage 54 communicates with the output port 12 of the master cylinder M, and the passage 56 communicates with the left front wheel brake B _FL .

Valve housing main body 46_OIn the valve chamber 4
7, a tapered valve seat 40 and the center of the valve seat 40
A cylindrical valve seat member 58 having a valve hole 57 that opens in the
When fitted and fixed, the valve seat member 58 and the passage
Filter 60 interposed between passages 54_OIs installed. Well
Check valve 17_FLIs the valve chamber 47 and the filter 60. _O
Between the valve seat member 58 and the valve housing main body 46_O
The orifice 18_FLCheck valve 17_FLAverage
In-line valve housing main body 46_OIs installed in.

The fixed core 38 _O is fitted and fixed to the end of the guide cylinder 35 _{O on} the valve housing 36 _O side. Further, in the valve chamber 47, the bottomed cylindrical body 45 and the valve housing main body 46 _O
A bearing member 61 is sandwiched therebetween, and a bearing member 62 is fitted and fixed to the tip end side of the guide cylinder 35 _O, that is, the bottomed cylindrical portion 49. The movable core 39 faces the fixed core 38 _O and is accommodated in the guide cylinder 35 _O so as to be movable in the axial direction. A rod 63 _O coaxially fixed to the movable core 39 so as to penetrate the fixed core 38 _O coaxially and axially movably and slidably supported at both ends by bearing members 61 and 62 is coaxially fixed,
A rod 63 _O is provided between the fixed core 38 _O and the movable core 39.
Is contracted, and the movable core 39 is biased by the spring 64 in a direction away from the fixed core 38 _O. A hemispherical valve element 41 that can be seated on the valve seat 40 is provided at one end of the rod 63 _O in the valve chamber 47. Moreover, the movable core 39 has a through hole 6 for allowing the working fluid to flow therethrough.
5 is drilled over the entire axial length.

By the way, all the normally open solenoid valves V _{OFL to} V _ORL and all the normally closed solenoid valves V _{CF L} are housed in the housing 37 _O with the valve housing 36 _O fitted in the fitting recess 50 _O. It is fixed to the base body 34 by fastening a pressing plate 66 common to V _CRL to one surface 34a of the base body 34. The pressing plate 66 is formed of a rigid magnetic metal into a rectangular flat plate shape, and is fastened to the one surface 34a of the base 34 by a plurality of bolts (not shown). In addition, each normally open solenoid valve V _OFL
V _ORL guide cylinder 35 _O ... and each normally closed solenoid valve V
Eight insertion holes 67 ... through which the guide cylinders 35 _C of _{CFL to} V _CRL (see FIG. 3) are inserted are provided, and the guide cylinders 35 _O and 35 _C are inserted into the corresponding insertion holes 67. by pressing plate 66 is fastened to one surface 34a of the base 34 engages with the stepped portion 45a of the housing 37 _O were, housing 37 _O is fixed to the base 34, the housing 37 _O of the guide tube 35 in this state _O is projected from the pressing plate 66.

The bobbin 42 is made of synthetic resin in a cylindrical shape surrounding the protruding portion of the guide cylinder 35 _{O from} the pressing plate 66, and the coil 43 is wound around the outer circumference of the bobbin 42.

The yoke 44 is used for all _normally open solenoid valves V _OFL.
-V _ORL , which is common to the pressing plate 66, and the abutting plate portion 44a that abuts the bobbin 42 of each normally open solenoid valve V _OFL -V _{ORL on} the side opposite to the pressing plate 66, and the outer edge of the corresponding abutting plate portion 44a. A support plate portion 44b, one end of which is connected at a right angle to the support plate portion 44b,
At the other end of b, there is a mounting plate portion 44c that is connected to the contact plate portion 44a at a right angle so as to extend to the opposite side and is formed of magnetic metal.
Is attached to the pressing plate 66. Then the yoke 44
The bobbins 22 of the _normally open solenoid valves V _{OFL to} V _ORL are sandwiched between the pressing plate 66 and the abutting plate portion 44 a of the yoke 44 in a state in which is attached to the pressing plate 66.

Moreover, the contact plate portion 44a of the yoke 44 is
Hole 71 for inserting the tip of each guide tube 35 _O , 35 _C
Are provided, and notches 72 that are connected to the holes 71 are provided, and a pair of connection terminals 73 that are connected to the coil 43 and project from the bobbin 42 are arranged in the notches 72. , Conductors such as lead wires are connected to these connection terminals 73.

The normally closed electromagnetic valve V _CFL ~V _CRL is a number of its components is intended to be identical to the normally open electromagnetic valves V _OFL ~V _ORL, normally open electromagnetic valves V _OFL ~ The same components as those of V _ORL are designated by the same reference numerals, and the configuration of the normally closed solenoid valve V _CFL will be described below.

[0030] In FIG. 3, the normally closed electromagnetic valves V _CFL is bottomed cylindrical guide tube 35 _C of the proximal valve housing 36 _C
37 _C and a guide tube 35 _C
Fixed core 38 _C fixed to the base end side of the fixed core 38
_The movable core 39 is spring-biased in a direction away from _C and is housed in the guide cylinder 35 _C , and is continuously connected to the movable core 39 so that the valve seat 40 provided on the valve housing 37 _C can be seated. a valve body 41, a coil 43 which is wound around the bobbin 42 surrounding the guide tube 35 _C, and a yoke 44 that magnetically couples the ends of the guide tube 35 _C over a portion of the coil 43 Prepare

The valve housing 36 _C has a bottomed cylindrical body 45.
And a valve housing main body 46 _C partly fitted in the bottomed cylindrical body 45 are caulked and coupled, and the outer surface shape thereof is formed into a stepped cylindrical shape. The guide cylinder 35 _C is formed by connecting a fixed core 38 _C to a cylindrical portion 45 b provided on the bottomed cylindrical body 45 via a non-magnetic portion 48 formed in a cylindrical shape by a non-magnetic material. The housing 37 _C is formed by coaxially connecting the base end of the guide cylinder 35 _{C to} the valve housing 36 _C via the step portion 45 a.

The valve housing 36_CIs one of the base 34
Fitting recess 50 provided on the surface 34a _CAnd the step 45
a is substantially flush with one surface 34a of the base 34
Fitted, the fitting recess 50_CIs the valve housing 36_Cof
Large-diameter portion 50 into which the bottomed cylindrical body 45 is fitted_CAAnd the valve house
46_CSmall diameter part 50 for fitting_CBAnd through the step
Then, it is provided coaxially. On the outer surface of the bottomed cylindrical body 45,
Large diameter part 50_CARing-shaped seal member 5 that elastically contacts the inner surface of the
1, the bottomed cylindrical body 45 and the valve how
And the valve chamber 47 formed between the main body 46c
An annular filter 52 interposed between the passages 56 is attached,
Main valve housing 46_C50 on the outer surface of_CBExterior of
An annular sealing member 53 that elastically contacts the_CIs installed.

A valve seat member 58 having a valve seat 40 and a valve hole 57 facing the valve chamber 47 is fitted and fixed to the valve housing main body 46 _C, and is eccentrically provided at the closed end of the fitting recess 50 _C. A filter 60 _C interposed between the passage 74 and the valve seat member 58 is installed. Also, the passage 74
Is connected to the reservoir R ₁ , as shown in FIG.

The movable core 39 having the through hole 65 is fixed.
Core 38_CFacing the guide tube 35 _CAxial movement possible
And the movable core 39 has one end fixed to the movable core 39.
38 _CIs movably supported in the axial direction and the other end is
A rod 63 supported by a bearing member 61 so as to be movable in the axial direction.
_CIs fixed coaxially, and the fixed core 38_CAnd movable core 3
Rod 63 between 9_CThe spring 64 surrounding the
It The movable core 39 is fixed by the spring 64._C
Is biased by a spring in a direction away from
63_CHas a hemispherical valve body 41 that can be seated on the valve seat 40.
It is provided.

The housing 37 _C of the normally closed solenoid valves V _{CFL to} V _{CRL is} the normally open solenoid valves V _{OFL to} V _ORL.
In the same manner as the housing 37 _O of being fixed to the base 34 by fastening the pressing plate 66 on one surface 34a of the base 34, the guide tube 35 _C of the housing 37 _C in the state protruded from the holding plate 66.

The bobbin 42 surrounding the protruding portion of the guide cylinder 35 _{C from} the pressing plate 66 is a _normally open solenoid valve V _OFL .
With the yoke 44 having the same shape as the yoke 44 on the V _ORL side,
It is attached to the pressing plate 66. That is, the bobbin 42 is sandwiched between the contact plate portion 44a of the yoke 44 attached to the pressing plate 66 and the pressing plate 66 in common with all the normally closed solenoid valves V _{CFL to} V _CRL , and the bobbin 42 is coiled. 43 is wound.

A passage 7 for connecting the valve hole 57 of the normally closed solenoid valve V _CFL to the reservoir R ₁ through the filter 60 _C.
A variable orifice 19 _FL is arranged at 4. The variable orifice 19 _FL has a valve housing 76 fitted and fixed in the passage 74, and a valve body 78 capable of being seated on a valve seat 77 provided at one end of the valve housing 76. Weight 79 housed in 76 and valve body 78
And a spring 80 that is compressed between the weight 79 and the valve housing 76 by exerting a spring force in a direction of separating the valve seat 77 from the valve seat 77.

The valve housing 76 is intended to be formed into a cylindrical shape by synthetic resin, on one end side of the valve housing 76 is a normally closed electromagnetic valve V _CFL side, the normally closed electromagnetic valves V _CFL
The valve hole 57 is provided with a valve hole 81 communicating with the filter 60 _C , and a tapered valve seat 77 having the valve hole 81 opened in the center is provided facing inward. The other end of the valve housing 76 has a closing plate 83 having a communication hole 82.
The weight 79, which is closed by means of the closing plate 83 and which is prevented from escaping outward by the closing plate 83 and is accommodated in the valve housing 76, is formed in a spherical shape. The valve body 78 includes a weight 79 to a valve seat 77.
It is provided so as to project toward the side, and is formed in a tapered shape so as to face the valve seat 77. Further, on the side of the weight 79, a flow groove 84 for allowing the flow of the hydraulic fluid is provided.
Incidentally, the substrate 34, V the normally open electromagnetic valve is attached to the base body 34 _{OF L} ~V _ORL and the guide tube 35 _O in the normally closed electromagnetic valves V _CFL ~V _CRL ..., 35 _C
It is mounted on the vehicle with the tip of the ... Directed forward along the traveling direction 75 of the vehicle. Therefore, in the variable orifice 19 _FL , when the vehicle deceleration is large, the weight 79 is relatively close to the valve seat 77, and the gap between the valve seat 77 and the valve body portion 78 is narrowed, so that the degree of throttling becomes large. On the other hand, when the vehicle body deceleration is small, the weight 79 relatively separates from the valve seat 77, and the gap between the valve seat 77 and the valve body portion 78 is widened, so that the throttle degree is small.

Next, the operation of this embodiment will be described. When the brake fluid pressure is reduced when the wheels are about to be locked, the corresponding solenoid valve among the normally closed solenoid valves V _{CFL to} V _CRL is used. Although opened by energizing the valve, the normally closed electromagnetic valves _{V CFL, V CFR, V CRL} , V CR R and the reservoir R _1,
Between R ₂ , variable orifices 19 _FL , 19 _FR , 19 _RL ,
Since 19 _RR is installed, wheel brakes B _{FL to} B _RL
The braking fluid pressure release speed from the variable orifice 19 _FL , 19
It will be limited by _FR , 19 _RL and 19 _RR . Moreover, each variable orifice 19 _FL , 19 _FR , 19 _RL , 19 _RR
Since the degree of throttle is increased as the vehicle body deceleration increases, the brake pressure is increased during antilock brake control where the friction coefficient of the road surface is relatively high and the vehicle deceleration is relatively large. The brake pressure can be gradually reduced during anti-lock brake control where the friction coefficient of the road surface is relatively low and the deceleration of the vehicle body is relatively small. It becomes possible to execute the brake control.

Moreover, each variable orifice 19 _FL , 19 _FR ,
Since 19 _RL and 19 _RR change the degree of aperture by moving the weight 79 according to the deceleration of the vehicle body, the ECU 2
The command by 6 is unnecessary, and the control by the ECU 26 can be simplified.

Each normally open solenoid valve V_OFL, V_OFR, V
_ORL, V_ORROrifice 18 in parallel with _FL, 18_FR, 18
_RL, 18_RRIs a normally open solenoid valve V_OFL, V_OFR, V_ORL，
V_ORRControl the brake fluid pressure from the master cylinder M when the valve is closed.
Each wheel brake B in a limited state_FL~ B_RLAct on
Since it can be operated, a normally open solenoid valve V_OFL, V_OFR, V_OR
L, V_ORRAnd normally closed solenoid valve V_CFL, V_CFR，
V_CRL, V_CRRBy closing both valves together, the brake fluid
The pressure can be increased slowly. Furthermore, normally open type electric
Magnetic valve V_OFL, V_OFR, V_ORL, V_ORROpen / close control
By adjusting them, more precise control of brake fluid pressure can be achieved.
It will be possible.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It is possible to do.

For example, a variable orifice capable of switching a plurality of throttling degrees is provided between the normally-closed solenoid valve and the reservoir, and the throttling degree is changed by the ECU 26 according to the detected vehicle deceleration. It is also possible to control the operation of the orifice.

[0044]

As described above, according to the first aspect of the invention, between the normally closed solenoid valve and the reservoir, there is a variable orifice that increases the degree of throttling as the vehicle deceleration increases. Since it is installed, the brake pressure is gently reduced during anti-lock brake control where the friction coefficient of the road surface is relatively high and the vehicle deceleration is relatively high. Is relatively small, the brake pressure is quickly reduced during anti-lock brake control,
It becomes possible to execute more effective anti-lock brake control.

According to the invention described in claim 2, in addition to the structure of the invention described in claim 1, the normally open solenoid valve is
Since the orifices are connected in parallel, braking fluid pressure can be applied to the wheel brakes via the orifice when the normally open solenoid valve is closed, and the brake fluid pressure can be moderated when the normally open solenoid valve is closed. It is possible to increase the pressure to, and it is possible to execute more precise antilock brake control.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a vehicle anti-lock brake device.

FIG. 2 is an enlarged vertical sectional view of a normally open solenoid valve.

FIG. 3 is an enlarged vertical sectional view of a normally closed solenoid valve.

[Explanation of symbols]

15 ... Anti-lock brake device 18 _FL , 18 _FR , 18 _RL , 18 _RR ... Orifice 19 _FL , 19 _FR , 19 _RL , 19 _RR ... Variable orifice 21 ₁ , 21 ₂ ... Return pump B _FL , B _FR , B _RL, B _RR・ ・ ・ Wheel brakes D ₁ , D ₂・ ・ ・ Damper M ・ ・ ・ Master cylinder R ₁ , R ₂・ ・ ・ Reservoir V _CFL 、 V _CFR 、 V _CRL 、 V _CRR・ ・ ・ Normally closed solenoid valve V _OFL , V _OFR , V _ORL , V _ORR・ ・ ・ Normally open solenoid valve

Claims (2)

[Claims] 1. A master cylinder (M) and a wheel breaker.
Ki (B_FL, B_FR, B _RL, B_RR) A normally open electric wire installed between
Magnetic valve (V_OFL, V_OFR, V_ORL, V_ORR) And the reservoir
(R₁, R₂) And the reservoir (R₁, R₂) And before
Wheel brake (B_FL, B_FR, B_RL, B_RR) Between
Normally closed solenoid valve (V_CFL, V_CFR, V_CRL, V_CRR)
And the reservoir (R₁, R₂) Is connected to the suction port
Return pump (21₁, 21₂) And a normally open solenoid valve (V
_OFL, V_OFR, V_ORL, V_ORR) And master cylinder
(M) is connected between the return pump (21)₁, 2
1 ₂) Discharge port is connected to the damper (D₁, D₂) And
In the vehicle anti-lock brake device equipped, normally closed
Type solenoid valve (V_CFL, V_CFR, V_CRL, V_CRR) And
Zaba (R₁, R₂) Between the car body deceleration will be large
The variable orifice (19_FL, 1
9_FR, 19_RL, 19_RR) Is installed
Anti-lock braking system for vehicles. 2. A normally open solenoid valve (V _OFL , V _OFR ,
V _ORL , V _ORR ) has orifices (18 _FL , 18 _FR ,
18. The antilock brake device for a vehicle according to claim 1, wherein 18 _RL and 18 _RR are connected in parallel.