JP3104140B2 - Fluid pressure control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention comprises a reaction piston having a front surface facing a reaction chamber, which is interlocked with and connected to an operation member so as to reduce the volume of the reaction chamber in accordance with the operation of the operation member. An operation reaction force generating means, a fluid pressure control valve capable of adjusting and outputting an output pressure of a fluid pressure supply source capable of outputting a constant fluid pressure in accordance with an operation amount of the operation member, and connected to the reaction force chamber And a fluid pressure control device including a stroke accumulator to be operated.

[0002]

2. Description of the Related Art Conventionally, such a fluid pressure control device is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 1-244956 and 2-1753.
61 and JP-A-2-299966.

[0003]

By the way, in the prior art, when the output pressure of the fluid pressure supply source is normal, the fluid pressure generated in the reaction chamber by operation of the operating member is accumulated by the stroke accumulator. In this way, an operation reaction force is generated, and a fluid pressure corresponding to the operation amount is generated by operating a fluid pressure control valve according to the operation amount of the operation member. When the pressure drops, the fluid pressure generated in the reaction force chamber is used. However, when the output pressure of the fluid pressure supply source is abnormally decreased, the fluid pressure generated in the reaction force chamber is unnecessarily consumed by the stroke accumulator, and the operation amount of the operation member increases.

The present invention has been made in view of the above circumstances, and when the output fluid pressure of the fluid pressure supply source is abnormally reduced, the amount of fluid consumed by the stroke accumulator is reduced to increase the operation amount of the operation member more than necessary. It is an object of the present invention to provide a fluid pressure control device in which the operation is prevented.

[0005]

According to a first aspect of the present invention, a stroke accumulator includes a cylinder body and a pressure accumulating chamber communicating with a reaction force chamber between the cylinder body and the cylinder body. And an accumulator piston slidably fitted to the cylinder body and a pilot chamber communicating with the fluid pressure supply source are formed between the cylinder body and the accumulator is moved to the side for reducing the volume of the pilot chamber. A backup piston slidably fitted to the cylinder body so as to move close to the piston, first biasing means for resiliently biasing the accumulator piston to the side of reducing the volume of the accumulator, A second urging means for resiliently urging the backup piston on the side of reducing the volume of the pilot chamber by making the load larger than the urging means; The backup urging force acting on the accumulator piston due to the proximity movement of the backup piston to the accumulator piston due to the decrease is configured to be greater than the elastic urging force acting on the accumulator piston when the fluid pressure in the pilot chamber is normal. You.

According to a second feature of the present invention, the first biasing means comprises a coil spring contracted between the accumulator piston and the backup piston.

[0007] Further, an apparatus according to a third aspect of the present invention includes:
An interval regulating member for regulating a minimum interval between the accumulator piston and the backup piston is provided.

[0008]

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

1 to 4 show a first embodiment of the present invention. FIG. 1 is a hydraulic circuit diagram of a fluid pressure control device,
FIG. 2 is a longitudinal sectional view showing the configuration of the fluid pressure transmission unit, and FIG.
FIG. 4 is a longitudinal sectional view showing the structure of the flow restricting means, and FIG. 4 is a longitudinal sectional view showing the structure of the control fluid pressure output unit and the flow restricting means.

First, in FIG. 1, the driving wheels of the vehicle
Left front wheel brake device B for front left and front right wheels_FLAnd
And right front wheel brake device B_FRAre attached and driven
The left rear and right rear wheels are equipped with brakes for the rear left wheel.
Place B_RLAnd right rear wheel brake device B_RRIs attached to each
Is done. On the other hand, the brake pedal 1 as an operating member
Is supplied with fluid pressure according to the amount of depression of the brake pedal 1.
The output fluid pressure of the source 3 can be controlled and the fluid pressure is supplied.
Depress the brake pedal 1 when the output pressure of the power source 3 drops abnormally
Control fluid pressure output unit that can output fluid pressure according to volume
2 is connected, and the output fluid pressure of the fluid pressure supply source 3 is positive.
During normal braking, which is normal, the control fluid pressure output unit 2
The amplified fluid pressure output from the fluid pressure transmission unit 4_FL, 4
_FRBrake device B for each front wheel_FL, B_FRGiven to
And the amplifying fluid from the control fluid pressure output unit 2.
Pressure is fluid pressure transmission unit 4_RAnd via the proportional pressure reducing valve 5
B for both rear wheels_RL, B_RRGiven to. Also
When the output fluid pressure of the fluid pressure supply source 3 drops abnormally
Control fluid pressure output corresponding to the amount of depression of brake pedal 1
The non-amplified fluid pressure output from the unit 2 is
Knit 4_FL, 4_FRBrake device B for each front wheel_FL,
B_FRAnd the control fluid pressure output unit 2
The non-amplified fluid pressure from the_RAnd
Brake device B for both rear wheels via the proportional pressure reducing valve 5_RL, B
_RRGiven to. Further, each front wheel brake device B_FL, B
_FRValves 6 provided correspondingly to the_FL, 6_FRand
Outflow valve 7 _FL, 7_FRAnd brake device B for both rear wheels_RL,
B_RRInflow valve 6 provided commonly to _RAnd outflow valve 7_RTo
From each brake device B_FL, B_FR, B_RL, B_RRBrake fluid
Hold or reduce pressure to perform antilock control.
The normally open solenoid valve 8 for traction control
By controlling the opening and closing of the normally closed solenoid valve 9, both driving wheels
Front wheel brake device B_FL, B_FRIncrease the brake fluid pressure of
Traction control can be performed.

The fluid pressure supply source 3 includes a fluid pressure pump 10 for pumping hydraulic oil from a reservoir R, and a fluid pressure pump 10
An accumulator 11 connected to the
And a pressure switch 12 for controlling the operation of.

Each of the brake devices B _FL , B _FR , B _RL , B
_{The RR} includes a cylinder 14 and a brake piston 15 slidably fitted in the cylinder 14, and is configured to reduce a fluid pressure acting on a brake fluid pressure chamber 16 defined between the cylinder 14 and the brake piston 15. It is configured to exert a braking force by moving the braking piston 15 in response.

The fluid pressure transmission units 4 _FL , 4 _FR , 4 _R are:
Since those having basically the same configuration, then there will be described a configuration of the fluid pressure transmission unit 4 _FL as a representative.

In FIG. 2, the fluid pressure transmitting unit 4
_FL is a cylindrical housing 18 having both ends closed.
A free piston 21 slidably fitted in the housing 18 with both ends facing the input fluid pressure chamber 19 and the output fluid pressure chamber 20, and biasing the free piston 21 toward the input fluid pressure chamber 19. The spring 22 housed in the output fluid pressure chamber 20 and the passage 24 and the output fluid pressure chamber 20 are cut off when the output fluid pressure of the fluid pressure supply source 3 is normal. A bypass valve 23 is provided in the housing 18 and configured to communicate between the passage 24 and the output fluid pressure chamber 20 in response to abnormally low pressure.

The bypass valve 23 is formed in a cylindrical shape and is disposed between the output fluid pressure chamber 2 and the free piston 21.
0, a valve housing 25 fitted and fixed in the housing 18 and a valve provided at an axially intermediate portion of the valve housing 25 by opening a valve hole 26 communicating with the output fluid pressure chamber 20 at the center. A seat 27 and a valve chamber 28 communicating with the passage 24
And a pushing piston 30 slidably fitted into the valve housing 25 with the end opposite to the valve chamber 28 facing the pilot chamber 29 and defined between the valve seat 27 and the valve seat 27.
A spherical valve element 31 accommodated in a valve chamber 28 so as to be seated on a valve seat 27, a pressing rod 32 gently penetrating the valve hole 26 and abutting on the valve element 31, A return spring 3 contracted between the pressing rod 32 and the valve housing 25 so as to exert a resilient force in a direction of contact with the body 31.
3 and a passage 34 is communicated with the pilot chamber 29.

In the bypass valve 23, when the fluid pressure in the pilot chamber 29 is lower than a predetermined value, the valve body 31 is pushed up by the spring force of the return spring 33 to a position where the valve hole 26 is opened, and the valve chamber 28 is opened. When the fluid pressure in the pilot chamber 29 becomes equal to or higher than the predetermined value, the pushing piston 30 moves so as to close the valve hole 26 with the valve body 31 and is closed.

According to the configuration of the fluid pressure transmission unit 4FL, the fluid pressure corresponding to the fluid pressure acting on the input fluid pressure chamber 19 with the bypass valve 23 closed is output to the output fluid pressure chamber 2 _FL.
0 and output fluid pressure chamber 2
0 working fluid does not flow to the input fluid pressure chamber 19 side. When the bypass valve 23 is opened, the fluid pressure from the passage 24 can be guided to the output fluid pressure chamber 20 even when the fluid pressure is not acting on the input fluid pressure chamber 19. Further, the output fluid pressure chamber 20 of the fluid pressure transmission units 4 _FL and 4 _FR
Are individually communicated with the brake fluid pressure chambers 16 of the brake devices B _FL and B _FR , respectively. The output fluid pressure chamber 20 of the fluid pressure transmission unit 4 _R is connected to the brake device B through a common proportional pressure reducing valve 5.
_RL, is connected to the brake fluid pressure chamber 16 of the B _RR.

Brake device B for front wheels_FL, B_FRCorresponding to
Fluid pressure transmission unit 4_FL, 4_FRTo the input fluid pressure chamber 19
Is the inflow valve 6_FL, 6_FRAnd outflow valve 7_FL, 7_FRBut in parallel
And the rear wheel brake device B_RL, B_RRTo
Corresponding fluid pressure transmission unit 4 _RTo the input fluid pressure chamber 19
Is the inflow valve 6_RAnd outflow valve 7_RAre connected in parallel.

The inflow valves 6 _FL , 6 _FR , 6 _R are normally open solenoid valves that close when energized, and the outflow valves 7 _FL , 7 _FR , 7 _R are normally closed solenoid valves that open when energized. . Thus, the outflow valve 7 _FL ,
And 7 _FR, 7 _R is a fluid pressure transmission unit 4 _FL, 4 _FR, 4 input fluid pressure chamber 19 of _R, each of which is interposed between the release passage 36 leading to the reservoir R. The inflow valves 6 _FL and 6 _FR are respectively provided between the input fluid pressure chamber 19 and the passage 35 of the fluid pressure transmission units 4 _FL and 4 _FR , and the inflow valve 6 _R is connected to the fluid pressure transmission unit 4 _FL as shown in FIG. It is interposed between the input fluid pressure chamber 19 of _R and the passage 36.

The proportional pressure reducing valve 5 has a conventionally well-known structure.
And the fluid pressure transmission unit 4 _ROutput fluid pressure chamber 2
0, the fluid pressure output from
Place B _RL, B_RRTo act on the brake fluid pressure chamber 16
I do.

The normally open solenoid valve 8 for traction control includes:
It is provided between the passages 38 and 34, and is switchable between a state in which the passages 38 and 34 communicate with each other in a demagnetized state and a state in which the passages 38 and 34 are shut off in an excited state. The normally closed solenoid valve 9 is connected to the fluid pressure supply source 3 and the passage 34.
Between the fluid pressure supply sources 3 in a demagnetized state.
And a state in which the path between the fluid pressure supply source 3 and the path 34 is communicated in an excited state. Thus, during traction control, the two solenoid valves 8, 9
Is excited.

A one-way valve 39 which allows only the flow of the working fluid from the passage 38 to the passage 34 is connected in parallel with the normally-open solenoid valve 8, and this one-way valve 39 is connected to the brake pedal during traction control. 1 functions to guide the fluid pressure output from the control fluid pressure output unit 2 to the passage 38 to the passage 34 when the brake operation is performed. Further, between the passages 34 and 35, as the fluid pressure on the passage 34 side becomes larger than the fluid pressure on the passage 35 side by a predetermined value or more, the passage 3
Differential pressure valve 4 that allows the working fluid to flow from passage 4 to passage 35
1 and a cup that functions as a one-way valve that permits the flow of working fluid from the passage 35 to the passage 34 as the fluid pressure on the passage 35 side becomes slightly higher than the fluid pressure on the passage 34 side. A flow restricting means 43 having a seal 42 is provided.

In FIG. 3, the flow restricting means 43 includes a bottomed cylindrical housing 45 having one end closed by a closing member 44, and a fluid chamber 46 communicating with the passage 34 is closed by the closing member 44.
And a differential pressure valve 41 having a valve housing 47 formed and fitted in the housing 45 is provided in the housing 45, and a cup seal 42 slidably contacting the inner surface of the housing 45 is mounted on the outer periphery of the valve housing 47. You.
A spring 5 for urging the valve housing 47 toward the other end of the housing 45 is provided between the valve housing 47 and the closing member 44.
3 is contracted.

The differential pressure valve 41 is provided in a valve chamber 48 formed in the valve housing 47 through the passage 35. A valve hole 49 communicating with the fluid chamber 46 is opened at the center of the valve chamber 48, and a valve seat 50 provided in the valve housing 47 is provided. A valve element 51 that can be seated on the
5 which exerts a resilient force in a direction in which the valve seat 50 is seated on the valve seat 50.
2 is accommodated, and the fluid pressure in the fluid chamber 46 communicating with the passage 34 is
The valve is opened as the fluid pressure becomes higher than the fluid pressure by a predetermined value or more.

The cup seal 42 prevents the flow of the working fluid from the fluid chamber 46 to the valve chamber 48. However, when the fluid pressure in the valve chamber 48 becomes larger than the fluid pressure in the fluid chamber 46, the cup seal 42 is closed. The valve is mounted on the outer periphery of the valve housing 47 so as to allow the working fluid to flow through the fluid chamber 46.

According to such a flow restricting means 43, each of the fluid pressure transmission units 4 _FL , 4 _FR , 4 _{R at the} beginning of the braking operation.
Fluid pressure transmission unit 4 _FL to bypass valve 23 is closed in response to fluid pressure increase in the pilot chamber 29 in,
4 passage _FR into the passage 35 leading to the input fluid pressure chamber 19 of 34
From the working fluid is blocked. That is, in the initial stage of the braking operation, the braking pressure acts on the input fluid pressure chambers 19 of the fluid pressure transmission units 4 _FL and 4 _FR after each bypass valve 23 is closed. When the braking operation force is released, the passage 35
Of the working fluid is released to the reservoir R by the cup seal 42 of the flow restricting means 43.

In FIG. 4, the control fluid pressure output unit 2
In the housing 55, an operation reaction force generating means 5 capable of generating an operation reaction force corresponding to the braking operation by the brake pedal 1 and generating a non-amplified fluid pressure corresponding to the operation force.
6 and a fluid pressure control valve 57 capable of controlling the output pressure of the fluid pressure supply source 3 according to the operation amount of the brake pedal 1 and outputting the amplified fluid pressure.

The housing 55 is formed in a cylindrical shape whose front end is closed by a closing member 58.
5 is provided with a cylinder hole 59.

The fluid pressure control valve 57 is configured such that a spool valve body 61 is slidably fitted to a cylindrical sleeve 60 fitted and fixed to a cylinder hole 59 on the closing member 58 side. A pressure chamber 62 communicating with the passage 36 is defined between the front end of the spool valve element 61 and the closing member 58, and the rear end of the spool valve element 61 slides into the cylinder hole 59 as one component of the operation reaction force generating means 56. It comes into contact with the front end of the interlocking piston 85 movably fitted. Further, a spring 64 for urging the spool valve body 61 rearward is housed in the pressure chamber 62. Therefore, the spool valve element 61 is subjected to a force toward the rear side by the fluid pressure of the pressure chamber 62 and the spring 64, and is pushed forward by the interlocking piston 85. The position of the spool valve element 61 in the sleeve 60 is determined by the balance.

The sleeve 60 is provided with an input valve hole 65, an output valve hole 66, and a release valve hole 67 at intervals in order from the front side to the rear side in the axial direction. A passage 68 communicating with the fluid pressure supply source 3;
The output valve hole 66 communicates with the passage 38, and the release valve hole 67 communicates with the release passage 37 communicating with the reservoir R. In addition, the spool valve element 61 is provided with an annular concave portion 69,
The length of the annular concave portion 69 along the axis of the spool valve body 61 is
When the spool valve element 61 is in the forward position, the output valve hole 6
6 communicates with the input valve hole 65 via the annular recess 69 and is shut off from the release valve hole 67. When the spool valve body 61 is in the retracted position, the output valve hole 66 is closed via the annular recess 69. And the input valve hole 65 is shut off.

Incidentally, a passage 38 communicating with the output valve hole 66 is provided.
The flow of the working fluid from the passage 38 to the passage 36 is made between the passage 38 and the passage 36 communicating with the pressure chamber 62 in response to the fluid pressure on the passage 38 side being larger than the fluid pressure on the passage 36 by a predetermined value or more. Allowable differential pressure valve 71 and a function as a one-way valve that allows the flow of working fluid from passage 36 to passage 38 as the fluid pressure on passage 36 becomes slightly greater than the fluid pressure on passage 38 And a flow restricting means 73 provided with a cup seal 72 exhibiting the following.

The flow restricting means 73 has a bottomed cylindrical housing 75 having one end closed by a closing member 74. A fluid chamber 76 communicating with the passage 38 is formed between the housing 75 and the closing member 74. Valve housing 77 fitted to
Is provided in the housing 75 and the cup seal 7 slidingly contacting the inner surface of the housing 75 is provided.
2 is mounted on the outer periphery of the valve housing 77. A valve housing 77 is provided between the valve housing 77 and the closing member 74.
Is biased toward the other end of the housing 75.

The differential pressure valve 71 is provided in a valve chamber 79 formed in the valve housing 77 through the passage 36, with a valve hole 80 communicating with the fluid chamber 76 being opened at the center, and a valve seat 81 provided in the valve housing 77. A valve body 82 that can be seated on the
8 that exerts a resilient force in the direction of seating on the valve seat 81
3 is accommodated, and the fluid pressure in the fluid chamber 76 communicating with the passage 38 is controlled by the valve chamber 79 communicating with the passage 36.
The valve is opened as the fluid pressure becomes higher than the fluid pressure by a predetermined value or more.

The cup seal 72 prevents the working fluid from flowing from the fluid chamber 76 to the valve chamber 79. However, when the fluid pressure in the valve chamber 79 becomes larger than the fluid pressure in the fluid chamber 76, the cup seal 72 closes. It is mounted on the outer periphery of the valve housing 77 so as to allow the working fluid to flow to the fluid chamber 76.

According to such a flow restricting means 73, no pressure is generated in the pressure chamber 62 until the fluid pressure output from the control fluid pressure output unit 2 to the passage 38 reaches a certain value at the beginning of the braking operation. , as well as serves to increase the fluid pressure to a certain value that is output to the passage 38 while the operation reaction force in the braking operation early does not occur, the fluid pressure transmission unit 4 _R bypass valve 23 is closed until the fluid pressure transmission of it is intended to suppress the fluid pressure output passage 36 leading to the input fluid pressure chamber 19 in the unit 4 _R. Thus the braking operation early, after the bypass valve 23 of the fluid pressure transmission unit 4 _R is closed, the fluid pressure in the passage 36 acts on the input fluid pressure chamber 19 of the fluid pressure transmission unit 4 _R. The cup seal 72 functions to release the working fluid in the passage 36 to the reservoir R when the braking operation force is released.

The operation reaction force generating means 56 includes the fluid pressure control valve 5
7, an interlocking piston 8 interlocked with and connected to the rear end of the spool valve body 61 and slidably fitted in the cylinder hole 59.
And a reaction force slidably fitted in the cylinder hole 59 with the front face facing a reaction force chamber 86 defined and interlocked with and connected to the brake pedal 1 and the back surface of the interlocking piston 85. A piston 87 and a spring 88 contracted between the pistons 85 and 87 are provided.

A restricting member 89 for restricting the retreat limit of the reaction force piston 87 is fixed to the rear end opening of the housing 55. A piston rod 90 which penetrates the restricting member 89 in a fluid-tight manner and movably penetrates therethrough. It is connected to the force piston 87 coaxially. On the other hand, a push rod 91 is connected to the brake pedal 1, and the front end of the push rod 91 is swingably connected to the piston rod 90. Therefore, in response to the depression operation of the brake pedal 1, the reaction force piston 87 moves forward in the direction of reducing the volume of the reaction force chamber 86.

A cup-shaped retainer 92 is fitted into the front end of the reaction force piston 87, and a bottomed cylindrical retainer 93 abuts on the back surface of the interlocking piston 85.
A spring 88 is contracted between the two. In addition, the rear end of the rod 94 movably penetrating the retainer 93 is engaged with the retainer 92 such that the retreat limit position with respect to the interlocking piston 85 is regulated by the retainer 93. This regulates the maximum distance between the interlocking piston 85 and the reaction force piston 87.

A valve hole 141 provided in the reaction force piston 87 through the reservoir R and a valve body 142 provided at the rear end of the rod 94 are used to switch the communication between the reaction force chamber 86 and the reservoir R. The shut-off valve 140 is opened when the distance between the interlocking piston 85 and the reaction force piston 87 is maximized, and connects the reaction force chamber 86 to the reservoir R. In this state, when the reaction force piston 87 moves forward with respect to the rod 94 from this state, the valve closes to shut off the space between the reaction force chamber 86 and the reservoir R.

The reaction chamber 86 communicates with a passage 95,
The passage 95, the fluid pressure transmission unit 4 _FL, 4 _FR, 4 _R
A flow regulating means 97 is provided between the passage 24 commonly communicating with the valve chamber 28 of the bypass valve 23 and the breathing passage 96 communicating with the reservoir R. A differential pressure valve 98 that allows the flow of the working fluid from the passage 95 to the passage 24 when the fluid pressure of the passage 24 becomes larger than a predetermined value or more, and the fluid pressure of the passage 24 becomes larger than the fluid pressure of the passage 95. A cup seal 99 that functions as a one-way valve that allows the flow of the working fluid from the passage 24 to the passage 95 in accordance with the pressure, and a passage from the breathing passage 96 communicating with the reservoir R when the passage 24 is depressurized. And a cup seal 100 that functions as a one-way valve that allows the flow of the working fluid to 24.

The flow restricting means 97 includes a cylindrical housing 101 having both ends closed. An input chamber 102 communicating with the passage 95 is formed between one end of the housing 101 and a breathing chamber 103 communicating with the breathing passage 95. A differential pressure valve 98 including a valve housing 104 formed between the other end of the housing 101 and fitted and fixed in the housing 101.
Are provided in the housing 101, and cup seals 99 and 100 slidably contacting the inner surface of the housing 101 are mounted on the outer periphery of the valve housing 104.

The valve housing 104 has an input chamber 102 formed between the housing 101 and an opening end of a cylindrical valve housing main body 105 having a bottom.
01, and a differential pressure valve 98 is provided in a valve chamber 107 formed in the valve housing 104 through the passage 24 and an input chamber 102.
A valve body 110 that can be seated on a valve seat 109 provided in the valve housing 104 by opening a valve hole 108 communicating with the valve hole 108 at the center.
And a spring 111 that exerts a resilient force in a direction in which the valve element 110 is seated on the valve seat 109. The fluid pressure in the input chamber 102 communicating with the passage 95 communicates with the passage 24. The valve is opened when the fluid pressure in the valve chamber 107 becomes larger than a predetermined value by a predetermined value or more.

Although the cup seal 99 prevents the working fluid from flowing from the input chamber 102 to the valve chamber 107, the valve seal 1
When the fluid pressure of 07 becomes higher than the fluid pressure of the input chamber 102, it is mounted on the outer periphery of the valve housing 104 so as to allow the working fluid to flow from the valve chamber 107 to the input chamber 102, and the cup seal 100 is Although the flow of the working fluid from the valve chamber 107 to the breathing chamber 103 is blocked, the valve chamber 107
Is mounted on the outer periphery of the valve housing 104 so as to allow the working fluid to flow from the breathing chamber 103 to the valve chamber 107 when the fluid pressure becomes smaller than the fluid pressure of the breathing chamber 103.

According to such a flow restricting means 97, during braking, the fluid pressure in the passage 95 is reduced by a predetermined value and acts on the passage 24, and the fluid pressure in the passage 95 is reduced in accordance with the decrease in the fluid pressure in the passage 95 due to the end of the braking operation. Of working fluid can escape to the passage 95 side, and each of the brake devices B _FL , B _FR , B _RL , B _RR
Piston 15 due to brake pad wear
When the pressure rises, the passage 24 can breathe through the cup seal 99 when the pressure rises, and through the cup seal 100 when the pressure decreases.

The operation passage 95 that communicates with the reaction force chamber 86 of the reaction force generating means 56 is connected to the stroke accumulator 113 ₁ as shown in Figure 1.

This stroke accumulator 113
₁ is a cylinder body 114 and a pressure accumulation chamber 1 communicating with a passage 95.
15 is formed between the cylinder body 114 and the cylinder body 114.
Accumulator piston 1 slidably fitted to 14
16, a backup piston 118 ₁ to form a pilot chamber 117 communicating with the passage 68 leading to a fluid pressure supply source 3 between the cylinder body 114, the elastic accumulator piston 116 on the side to reduce the volume of the accumulation chamber 115 a first biasing means 119 for biasing, the resiliently urging the backup piston 118 ₁ on the side to reduce the volume of the pilot chamber 117 and the load larger than the first biasing means 119 2
And a biasing means 120.

The cylinder body 114 has a first end closed at one end.
A second cylinder hole 122 having a diameter larger than that of the first cylinder hole 121 and having one end coaxially connected to the other end of the first cylinder hole 121 via a step 124;
The second cylinder hole 1 has a larger diameter than the cylinder hole 122 and
A third cylinder hole 123, one end of which is coaxially connected via a step 125 and the other end of which is closed, is provided at the other end of 22. Thus, the accumulator piston 116 forms a pressure accumulation chamber 115 between itself and one end wall of the cylinder body 114, and is slidably fitted in the first cylinder hole 121. The backup piston 118 ₁ defines a release chamber 126 communicating with the reservoir R between the backup piston 118 ₁ and the accumulator piston 116, and is slidably fitted to the second and third cylinders 122 and 123. 124 and the inner surface of the third cylinder hole 123 and the backup piston 118 ₁
A pilot chamber 117 is defined between the pilot chamber 117 and the outer surface of the pilot chamber 117. Further backup piston 118 ₁ and the accumulator piston to the side spring chamber 127 communicating with the release chamber 126 have been defined, the accumulator 115 to increase the volume of the accumulation chamber 115 is formed between the other end wall of the cylinder body 114 A return spring 135 that urges 116 with a small spring load is housed.

The backup piston 118 ₁ is intended to be formed into a cylindrical shape, receives a collar 128 which issued radially inwardly Zhang is provided at its axially intermediate portion.

The first biasing means 119, an accumulator piston 116 and the backup piston 118 a pair of coil springs 130 and 131 between ₁ are those formed by interposed in series with intervening guide member 132 therebetween.
Guide member 132 is intended to be slidably fitted in the backup piston 118 _1, one coil spring 13
0 is the accumulator piston 116 and the guide member 132
And the other coil spring 131 is connected to the guide member 1.
It is arranged between the 32 and the backup piston 118 _first receiving flange 128. Thus, both coil springs 130, 131
Are different from each other so that the spring load characteristic that urges the accumulator piston 116 toward the accumulator 115 changes while the accumulator piston 116 moves toward the side where the volume of the accumulator 115 increases. Is set.

The second biasing means 120, which is housed in the spring chamber 127, between a pair of coil springs 133 and 134 parallel to each other with the other end wall of the backup piston 118 ₁ and the cylinder body 114 The spring load of the second urging means 120 is set to be larger than that of the first urging means 119.

Such a stroke accumulator 11
3 in _1, in the state where the normal fluid pressure from the fluid pressure supply source 3 fluid pressure supply source 3 is operating properly to the pilot chamber 117 is exerted, the backup piston 118 as shown in FIG. 1 ₁ Moves toward the side where the volume of the pilot chamber 117 is increased against the urging force of the second urging means 120, that is, the side away from the accumulator piston 116. However, if the operation of the fluid pressure supply source 3 becomes abnormal and the fluid pressure in the pilot chamber 117 drops abnormally,
Backup piston 118 ₁ is moved to the side close to the side ie the accumulator piston 116 to reduce the volume of the pilot chamber 117 by the spring force of the second biasing means 120. Therefore, a pair of coil springs 13 in series with each other
Bullet with onset force of the first biasing means 119 composed of 0,131, by two coil springs 130, 131 are compressed, the backup piston 118 ₁ fluid pressure in the pilot chamber 117 is normal is not retracted Larger than when

Next, the operation of this embodiment will be described. First, assuming a normal braking operation in a state where the fluid pressure supply source 3 is operating normally, the inflow valves 6 _FL , 6 _FR , 6
_R and the outflow valves 7 _FL , 7 _FR , 7 _R are in a demagnetized state (the state shown in FIG. 1), and a normally-open solenoid valve 8 for traction control.
The normally closed solenoid valve 9 is also in the demagnetized state (the state shown in FIG. 1). Therefore, the passage 38 for guiding the amplified fluid pressure from the control fluid pressure output unit 2 is provided in each fluid pressure transmission unit 4 _FL ,
4 _FR, 4 pilot chamber 29 of the bypass valve 23 in the _R
Are connected to the input fluid pressure chambers 19 of the fluid pressure transmission units 4 _FL and 4 _FR via the flow restricting means 43 and the path 35, and the flow restricting means 73 and the 36 is in a state of communication with the input fluid pressure chamber 19 of the fluid pressure transmission unit 4 _R through.

When the brake pedal 1 is depressed in this state,
In the control fluid pressure output unit 2, the reaction force piston 87 operates forward to apply a forward force to the interlocking piston 85 via the spring 88, thereby causing the spool valve body 6 of the fluid pressure control valve 57 to operate.
1 moves forward while reducing the return spring 64.

The spool valve element 61 advances to a position where the input valve hole 65 communicates with the output valve hole 66 and is cut off from the release valve hole 67 until the output pressure of the passage 38 reaches a certain value. The fluid pressure in the pressure chamber 62, that is, the fluid pressure urging the spool valve body 61 to the retracted position is not generated by the function of the differential pressure valve 71 in the means 73, and the fluid pressure that rapidly increases is output to the passage 38 at the beginning of the braking operation. Is done. Moreover, the bypass valves 23 in each of the fluid pressure transmission units 4 _FL , 4 _FR , 4 _R are closed by the functions of the differential pressure valves 41, 71 of the flow restricting means 43, 73, and the fluid pressure is transmitted by opening the differential pressure valves 41. The fluid pressure acts on the input fluid pressure chambers 19 of the units 4 _FL and 4 _FR from the passage 35, respectively, and the fluid pressure is applied from the passage 36 to the input fluid pressure chamber 19 of the fluid pressure transmission unit 4 _R by opening the differential pressure valve 71. Will work.

In the fluid pressure control valve 57, a force in the retreating direction which is the sum of the spring force of the return spring 64 and the force obtained by multiplying the sectional area of the spool valve body 61 by the fluid pressure of the pressure chamber 62. However, when the spring load of the spring 88 becomes larger, the reaction force piston 87 moves forward with respect to the interlocking piston 85 while contracting the spring 88, the shutoff valve 140 is closed, and the reaction force chamber 86 is shut off from the reservoir R. When the volume of the reaction force chamber 86 is reduced, a fluid pressure is generated in the reaction force chamber 86.

Therefore, the pressure accumulating chamber 115 of the stroke accumulator 113 ₁ for securing the operation stroke.
There spite communicates with the reaction chamber 86, the initial operation stroke does not become invalid stroke is absorbed by the stroke accumulator 113 _1.

[0057] Thereafter, the fluid pressure of the reaction chamber 86 would be accumulated in the accumulation chamber 115 of the stroke accumulators 113 _1, by the operation force opposing the biasing force of the first biasing means 119 acting on the accumulator piston 116 the reaction piston 87 is further advanced, it is possible to ensure the operation stroke by the stroke accumulator 113 _1.

After the fluid pressure is generated in the reaction force chamber 86, the spool valve element 61 of the fluid pressure control valve 57 has the force in the retreating direction from the pressure chamber 62 side and the force in the forward direction from the reaction force chamber 86 side. It moves back and forth so as to be balanced, whereby the output pressure of the fluid pressure supply source 3 is controlled, and the amplified fluid pressure corresponding to the operation amount of the brake pedal 1 is output from the control fluid pressure output unit 2 to the passage 38, Brake devices B _FL , B _FR , B _RL , B _RR
Thus, a braking force due to the amplified fluid pressure is obtained.

At the time of such braking, when the pedaling force of the brake pedal 1 becomes excessive and the wheels are about to be locked, the inflow valve 6 corresponding to the wheels that are about to be locked
_FL, is excited to 6 _FR, 6 _R, passage 35 and the fluid pressure transmission unit 4 _FL, 4 _FR between, as well as blocking the passages between 36 and fluid pressure transmission unit 4 _R. This suppresses an increase in the braking force to avoid the wheels from being locked. When this still wheel is likely to enter the locked state, communicates the outflow valve 7 _FL, 7 _FR, 7 to energize the _R fluid pressure transmission unit 4 _FL to 4 _R input fluid pressure chamber 19 corresponding to the reservoir R By reducing the braking pressure, the tendency to lock the wheels can be eliminated.

During the above-mentioned braking, failure of the hydraulic pump 10 or the like may occur.
Consider the case where the output pressure of the fluid pressure supply source 3 drops abnormally.
Set. In this case, the passage from the control fluid pressure output unit 2 to the passage
In response to a decrease in the fluid pressure output to
Knit 4_FL, 4_FR, 4_RThe bypass valve 23 in
Open each one. Therefore, the depressing operation of the brake pedal 1
The reaction force chamber 8 according to the forward movement of the reaction force piston 87
6. The fluid pressure generated in the passage 6
The fluid pressure transmission unit 4 via the passage 24_FL, 4 _FRBye
Brake device B for both front wheels from pass valve 23_FL, B_FRInto it
And the fluid pressure transmission unit 4_RBye
Rear wheel brake via pass valve 23 and proportional pressure reducing valve 5
Device B_RL, B_RRWill be given to Therefore the flow
Operate even when the output pressure of the body pressure supply source 3 is abnormally low.
The fluid pressure generated in the reaction force chamber 86 of the reaction force generation means 56 is
Brake device B_FL, B_FR, B_RL, B_RRActing on
Can be.

At this time, the stroke accumulator 113
In _1, by with the lower output fluid pressure drop of the fluid pressure source 3 is abnormally low fluid pressure in the pilot chamber 117, thereby backup piston 118 ₁ is advanced operation, the acting on the accumulator piston 116 1
The spring load of the urging means 119 has increased. Therefore, when the output fluid pressure of the fluid pressure supply source 3 is abnormally decreased, the fluid pressure generated in the reaction force chamber 86 is reduced by the stroke accumulator 113.
Without being consumed unnecessarily by _1, the brake pedal 1
The stepping stroke of the vehicle does not become unnecessarily large.

Further, when the driving force of the engine becomes excessive during non-braking and the driving wheels are likely to slip excessively,
The normally open solenoid valve 8 and the normally closed solenoid valve 9 for traction control are excited. As a result, the output fluid pressure of the fluid pressure supply source 3 acts on the input fluid pressure chamber 19 of the fluid pressure transmission means 4 _FL , 4 _FR , and the brake devices B _FL , B of the left and right front wheels as drive wheels.
_A braking force is generated in the _FR , and the occurrence of excessive slip is avoided. Thereafter, as in the case of anti-lock control described above, the excitation and demagnetization control of the inlet valve 6 _FL, 6 _FR and the outlet valve 7 _FL, 7 _FR, can control the braking force.

FIG. 5 shows a second embodiment of the present invention, in which parts corresponding to those of the first embodiment are denoted by the same reference numerals.

[0064] In the stroke accumulator 113 _2, an accumulator piston 116, the backup piston 118 between the _2, receiving portion 138 provided to the rear end to the backup piston 118 ₂ with a possible contact with the front end to the accumulator piston 116 An interval regulating member 137 formed in a rod shape that can be brought into contact with is provided. A flange portion 137a extending radially outward is provided at an intermediate portion of the gap regulating member 137.
The pair of coil springs 130 and 131 constituting the part 19 are arranged in series with the flange 137a interposed therebetween.

[0065] Moreover the space restricting member 137, the pistons 11 at both ends before when advancing the backup piston 118 ₂ and the fluid pressure is abnormally low is ₂ the backup piston 118 reaches the forward limit of the pilot chamber 117
It is set to a length that is brought into contact with 6,118 _2.

Such a stroke accumulator 11
In 3 _2, the working fluid pressure source 3 becomes upset,
When the fluid pressure in the pilot chamber 117 drops abnormally,
Backup piston 118 ₂ is the spring force of the second biasing means 120 by moving the side close to the side ie the accumulator piston 116 to reduce the volume of the pilot chamber 117, the pistons 116 through the space restricting member 137,
118 ₂ interlocking is connected. As a result, the accumulator piston 116 is urged by the second urging means 120 having a spring load larger than that of the first urging means 119 to reduce the accumulator chamber 115. Bullet with onset force acting on the accumulator piston 116 therefore, becomes larger than when the backup piston 118 ₂ fluid pressure in the pilot chamber 117 is normal has been retracted, the fluid pressure generated in the reaction chamber 86 can be prevented from being wastefully consumed by the stroke accumulator 113 _2, the depression stroke of the brake pedal 1 can be prevented from becoming larger than necessary.

FIG. 6 shows a third embodiment of the present invention, and portions corresponding to the first and second embodiments are denoted by the same reference numerals.

[0068] In the stroke accumulator 113 _3, an accumulator piston 116, the approach movement rod-shaped restriction member 137 for restricting the minimum interval 'is the backup piston 118 ₃ of the accumulator piston 116 between the backup piston 118 ₃ It is integrally connected to the backup piston 118 ₃ so as to abut on the accumulator piston 116.

According to the third embodiment, the fluid pressure supply source
3 malfunctions, and the fluid pressure in pilot chamber 117 rises.
When abnormally lowered, the backup piston 118_Three
Is accumulator pin by the spring force of the second urging means 120.
By moving to the side close to the stone 116, the distance
Both pistons 116 and 118 are controlled via a regulating member 137 '. _Three
Will be linked and linked, and the accumulator pistes
The urging force acting on the
Is normal and the backup piston 118_Three
Can be larger than when the
The fluid pressure generated in the chamber 86 is the stroke accumulator 1
13_ThreeThe brake pedal
That the stepping stroke of Le1 becomes larger than necessary
Can be prevented.

In each of the above embodiments, a coil spring is used as the first and second urging means. However, a gas spring may be used.

The present invention is not limited to a vehicle brake device in which a boosting brake pressure is applied to each of the brake devices B _FL , B _FR , B _RL , and B _RR in accordance with the depression operation of the brake pedal 1. An operation reaction force generating means coupled to and connected to the operation member, and a fluid pressure control valve capable of adjusting and outputting the output pressure of a fluid pressure supply source capable of outputting a constant fluid pressure in accordance with the operation amount of the operation member And a stroke accumulator connected to the reaction force chamber of the operation reaction force generating means, and is widely applicable.

[0072]

As described above, according to the first feature of the present invention, the pilot urging force acting on the accumulator piston due to the close movement of the backup piston to the accumulator piston due to the abnormal decrease in the fluid pressure in the pilot chamber is controlled by the pilot. When the output fluid pressure of the fluid pressure supply drops abnormally, the fluid pressure generated in the reaction chamber is consumed more than necessary because the pressure is greater than the repulsive urging force acting on the accumulator piston when the fluid pressure in the chamber is normal. This can prevent the operation stroke of the operation member from becoming unnecessarily large.

According to the second feature of the present invention, the first biasing means comprises a coil spring contracted between the accumulator piston and the backup piston.
By increasing the load of the urging means, the effect of the first feature can be achieved with a compact configuration.

A device according to a third aspect of the invention further comprises:
Since an interval regulating member that regulates the minimum interval between the accumulator piston and the backup piston is provided, the accumulator piston and the backup piston are interlocked and connected when the output fluid pressure of the fluid pressure supply is abnormally low, and the accumulator piston is connected by the second urging means. The effect of the above-mentioned first characteristic can be obtained by energizing.

[Brief description of the drawings]

FIG. 1 is a fluid pressure circuit diagram of a fluid pressure control device according to a first embodiment.

FIG. 2 is a longitudinal sectional view illustrating a configuration of a fluid pressure transmission unit.

FIG. 3 is a longitudinal sectional view showing a configuration of a flow restricting means.

FIG. 4 is a longitudinal sectional view showing a configuration of a control fluid pressure output unit and a flow restricting means.

FIG. 5 is a longitudinal sectional view of a stroke accumulator according to a second embodiment.

FIG. 6 is a longitudinal sectional view of a stroke accumulator according to a third embodiment.

[Explanation of symbols]

1 brake pedal 3 ...... fluid pressure source 56 as ...... operating member ...... operation reaction force generating means 57 ...... fluid pressure control valve 86 ...... reaction chamber 87 ...... reaction piston 113 _1, 113 _2, 113 ₃ Stroke accumulator 114 Cylinder 115 Accumulator 116 Accumulator piston 117 Pilot chamber 118 ₁ , 118 ₂ , 118 ₃ Backup piston 119 First biasing means 120 Second Urging means 130, 131 ... coil spring 137, 137 '... interval regulating member

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshihiro Urai 1-4-1 Chuo, Wako-shi, Saitama Inside of Honda R & D Co., Ltd. (72) Inventor Makoto Horiuchi 840 Kokubu, Kojibu, Ueda-shi, Nagano Nissin Kogyo Co., Ltd. (72) Inventor Ryuji Horiuchi 840 Kokubu, Ueda-shi, Nagano Nissin Kogyo Co., Ltd. (56) References JP-A-2-175361 (JP, A) JP-A-2-306855 (JP, A) JP-A-58-39551 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60T ⁷ /12-8/96 F15B 11/02

Claims (3)

(57) [Claims] A reaction piston (87) having a front surface facing the reaction chamber (86) reduces the volume of the reaction chamber (86) according to the operation of the operation member (1). An operation reaction force generating means (56), which is linked and connected to 1), and an output pressure of a fluid pressure supply source (3) capable of outputting a constant fluid pressure in accordance with an operation amount of the operation member (1). and adjusting and outputting possible fluid pressure control valve (57), the stroke accumulator (113 ₁ connected to the reaction force chamber (86), 113 _2,
113 ₃ ), the stroke accumulator (113 ₁ , 113 ₂ , 113 ₃ )
Is formed between a cylinder body (114) and a pressure accumulation chamber (115) communicating with a reaction force chamber (86) between the cylinder body (114) and is slidably fitted to the cylinder body (114). A pilot chamber (117) communicating with the accumulator piston (116) and the fluid pressure supply source (3) is formed between the cylinder body (114) and the pilot chamber (1).
The backup piston (118 ₁ , 118 ₂ , 118 ₃ ) slidably fitted to the cylinder body (114) so that the movement to the side of reducing the volume of 17) becomes the movement close to the accumulator piston (116). ) And the accumulator (1
15) first biasing means (119) for resiliently biasing the accumulator piston (116) to the side of reducing the volume of (15);
Second biasing means for resiliently biasing the backup pistons (118 ₁ , 118 ₂ , 118 ₃ ) to a side where the load is larger than the first biasing means (119) and the volume of the pilot chamber (117) is reduced. (120) and the pilot room (11).
Backup piston (1) accompanying fluid pressure drop
18 ₁ , 118 ₂ , 118 ₃ ) moves toward the accumulator piston (116), and the resilient urging force acting on the accumulator piston (116) is applied to the pilot chamber (1).
17) A fluid pressure control device characterized in that the fluid pressure control device is configured to increase the repulsive urging force acting on the accumulator piston (116) when the fluid pressure is normal. 2. A first biasing means (119), that a coil spring (130, 131) which is mounted under compression between the accumulator piston (116) and the backup piston (118 _1, 118 _2, 118 ₃₎ The fluid pressure control device according to claim 1, wherein 3. The fluid pressure according to claim 1, further comprising an interval regulating member (137, 137 ') for regulating a minimum interval between the accumulator piston (116) and the backup piston (118 ₂ , 118 ₃ ). Control device.