JP3195015B2 - Fluid pressure control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention relates to a housing having an input port connected to a fluid pressure supply, an output port connected to a fluid pressure device, and a release port connected to a reservoir, and the output port and release. The housing is slidably fitted between a retracted position communicating between the ports and an advanced position communicating between the output port and the input port, and the sliding member is urged in the retracting direction. A reaction force chamber formed in the housing facing the front surface of the sliding member to generate fluid pressure, and connected to the output port; A pressing piston interlocked and connected to the end, an input piston slidably fitted to the housing and interlocked and connected to the operating member, and a rear surface of the pressing piston and a front of the input piston. And a pressure chamber formed between pressure receiving area facing the reaction force chamber is a fluid pressure control device is set smaller than the pressure receiving area facing the pressure chamber of the pressure piston of the sliding member.

[0002]

2. Description of the Related Art Conventionally, such a fluid pressure control device is known, for example, from Japanese Patent Laid-Open No. 3-220054.

[0003]

In the above-mentioned fluid pressure control device, since the pressure receiving areas of the pressing piston and the input piston facing the pressure chamber are set to be equal, the state in which the fluid pressure is generated in the reaction force chamber is generated. When the fluid pressure fluctuates, the pressure fluctuation in the pressure chamber due to the sliding of the sliding member back and forth is relatively large, and the kickback acting on the operating member from the input piston becomes relatively large. When fluid pressure is generated in the reaction force chamber, when the sliding member is further operated to advance the sliding member while the sliding member blocks between the output port and the input port, the input piston is used. Is 1: 1 and the pushing piston is 1: 1, the force required to advance the sliding member to the position where the output port and the input port communicate with each other is relatively large.

The present invention has been made in view of such circumstances, and provides a fluid pressure control device that reduces kickback due to reaction force fluctuation and reduces ineffective stroke that accompanies further operation of an operation member. The purpose is to:

[0005]

According to a first aspect of the present invention, a pressure receiving area of a pressure piston facing a pressure chamber is smaller than a pressure receiving area of a pressure piston facing a pressure chamber of an input piston. Is set.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the pressure chamber is provided with a fluid through a bypass valve which closes in response to an increase in output pressure from an output port. Connected to pressure equipment.

[0007]

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

1 to 7 show an embodiment of the present invention. FIG. 1 is a hydraulic circuit diagram of a brake pressure control device, FIG. 2 is a longitudinal sectional view showing a configuration of a hydraulic pressure transmission unit,
3 is a longitudinal sectional view showing the configuration of the flow control unit, FIG. 4 is a longitudinal sectional view showing a partial configuration of the fluid pressure control device, FIG. 5 is a longitudinal sectional view showing the remaining configuration of the fluid pressure control device, and FIG. FIG. 7 is a vertical sectional view showing the structure of the stroke accumulator, and FIG. 7 is a diagram showing the relationship between the input piston stroke and the spring reaction force in the auxiliary fluid pressure generating means.

First, referring to FIG.
For front left wheel and front right wheel, for front left wheel as fluid pressure device
Brake device B_FLAnd right front wheel brake device B_FRBut
Each is mounted on the left rear wheel and right rear wheel as driven wheels
Is the brake device B for the left rear wheel as a fluid pressure device_RLAnd
And right rear wheel brake device B_RRAre respectively mounted. one
On the other hand, the brake pedal 1 as an operating member
Output flow of the fluid pressure supply source 3 according to the depression amount of the key pedal 1
The body pressure can be controlled and the output pressure of the fluid pressure supply source 3
When abnormally low, the flow according to the amount of depression of the brake pedal 1
A fluid pressure control device 2 capable of outputting body pressure is connected,
During normal braking when the output fluid pressure of the fluid pressure supply source 3 is normal
Means that the amplified fluid pressure output from the fluid pressure control device 2 is fluid
Pressure transmission unit 4_FL, 4_FRThrough each front wheel brake device
Place B_FL, B_FRAnd the fluid pressure control device 2
Fluid pressure transmission unit 4_RAnd proportional
Brake device B for both rear wheels via pressure reducing valve 5_RL, B_RRTo
available. The output fluid pressure of the fluid pressure supply source 3 is abnormally low.
When it is released, it corresponds to the amount of depression of the brake pedal 1
The non-amplified fluid pressure output from the fluid pressure control device 2 is a fluid pressure
Transmission unit 4_FL, 4_FRThrough each front wheel brake device
B_FL, B_FRAnd the fluid pressure control device 2
The non-amplified fluid pressure of the fluid pressure transmission unit 4_Rand
Brake device B for both rear wheels via proportional pressure reducing valve 5_RL, B_RR
Given to. Further, each front wheel brake device B_FL, B_FR
Inlet valve 6 corresponding to each_FL, 6_FRAnd outflow valve 7_FL,
7_FRAnd brake device B for both rear wheels_RL, B_RRCommon to
A certain inflow valve 6_RAnd outflow valve 7 _RBy each brake device
B_FL, B_FR, B_RL, B_RRHold or reduce brake fluid pressure
To perform anti-lock control.
Normally open solenoid valve 8 and normally closed solenoid valve 9 for controlling
Brake control B for both front wheels_FL, B_FRof
Traction control can be performed by increasing the braking fluid pressure.
it can.

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.

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.
And 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. Passage 24 with abnormal pressure drop
And a bypass valve 23 configured to communicate between the output fluid pressure chambers 20 and provided in the housing 18.

The output fluid pressure chamber 20 communicates with a brake device _BFL via a passage 25. On the outer periphery of the free piston 21, there is provided an annular recess which forms an annular chamber 26 between the inner surface of the housing 18 and the outer periphery of the free piston 21 between the annular chamber 26 and the input fluid pressure chamber 19. A seal member 27 is mounted on the outer periphery of the free piston 21 between the annular chamber 26 and the output fluid pressure chamber 20. Thus, at least the seal member 28 is a cup seal, and allows the working fluid to flow from the annular chamber 26 to the output fluid pressure chamber 20. Moreover, a communication hole 29 communicating with the annular chamber 26 is provided in the housing 18 irrespective of the stroke of the free piston 21,
The communication hole 29 is connected to the reservoir R via the release passage 40, and the annular chamber 26 is always in communication with the reservoir R.

The output fluid pressure chamber 2 is formed between the free piston 21 and the cylindrical shape.
0 and a valve housing 30 fitted and fixed in the housing 18, and a valve hole 31 communicating with the output fluid pressure chamber 20 being opened at the center to output fluid pressure chamber 2 of the valve housing 30.
A valve seat 32 provided at a portion close to zero and a valve chamber 33 communicating with the passage 24 are defined between the valve seat 32 and an end opposite to the valve chamber 33 faces the pilot chamber 34. A drive piston 35 slidably fitted into the valve housing 30 and a valve chamber 33 capable of seating on the valve seat 32.
The valve body 36 is housed in a spring chamber 37 formed between the drive piston 35 and the valve housing 30 and is separated from the valve seat 32. And a spring 38 for applying a repulsive force in the direction to the drive piston 35. A passage 44 is connected to the pilot chamber 34, and the spring chamber 37 is connected to the reservoir R via a release passage 40.

In the bypass valve 23, when the fluid pressure in the pilot chamber 34 is lower than a predetermined value, the spring 3
The drive piston 35 moves to the position where the valve element 36 opens the valve hole 31 by the spring force of 8, the valve chamber 33 communicates with the output fluid pressure chamber 20, and the fluid pressure in the pilot chamber 34 becomes equal to or higher than the predetermined value. Then, the drive piston 35 moves so as to close the valve hole 31 with the valve element 36, and the valve is closed.

According to such a configuration of the fluid pressure transmitting unit 4 _FL , 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.
It is possible to output from zero, and the working fluid in the output fluid pressure chamber 20 does not flow to the input fluid pressure chamber 19 side. When the bypass valve 23 is open, the input fluid pressure chamber 1
The fluid pressure from the passage 24 can be guided to the output fluid pressure chamber 20 even when fluid pressure is not acting on 9.

Furthermore the fluid pressure transmission unit 4 _FL, 4 _FR output fluid pressure chamber 20 the brake device B _FL, communicates respectively individually B _FR, fluid pressure transmission unit 4 _R output fluid pressure chamber 20 is proportional common The brake device B _RL ,
Connected to 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 40 leading to the reservoir R. The inflow valves 6 _FL and 6 _FR are respectively interposed between the input fluid pressure chamber 19 and the passage 41 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 42.

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 and proportionally reduce the fluid pressure output from
Rake device B_RL, B_RRIt works to act on.

The normally open solenoid valve 8 for traction control includes:
It is provided between the passages 43 and 44, and is switchable between a state in which the passages 43 and 44 communicate with each other in a demagnetized state and a state in which the passages 43 and 44 are shut off in an excited state. The normally closed solenoid valve 9 for traction control is interposed between the fluid pressure supply source 3 and the passage 44, and shuts off the fluid pressure supply source 3 and the passage 44 in a demagnetized state. The state in which the fluid pressure supply source 3 and the passage 44 are communicated with each other in the excited state can be switched. Thus, during traction control, both solenoid valves 8 and 9 are excited.

A one-way valve 45 which allows only the flow of the working fluid from the passage 43 to the passage 44 is connected in parallel with the normally-open solenoid valve 8. The one-way valve 45 is connected to the brake pedal during traction control. 1 functions to guide the fluid pressure output from the fluid pressure control device 2 to the passage 43 to the passage 44 when the brake operation is performed.

Further, the flow of the working fluid from the passage 44 to the passage 41 is permitted between the passages 44 and 41 as the fluid pressure on the passage 44 side becomes larger than the fluid pressure on the passage 41 side by a predetermined value or more. The differential pressure valve 46 functions as a one-way valve that permits the flow of the working fluid from the passage 41 to the passage 44 as the fluid pressure on the passage 41 becomes slightly higher than the fluid pressure on the passage 44. A flow restricting unit 48 including a cup seal 47 is provided.

In FIG. 3, the distribution control unit 48 is
Cylindrical housing 5 with one end closed by a closing member 49
In the housing 50, a fluid chamber 51 communicating with the passage 44 is formed between the closing member 49 and the valve housing 5 fitted in the housing 50.
2 is provided, and a cup seal 47 that slides on the inner surface of the housing 50 is mounted on the outer periphery of the valve housing 52. Further, the valve housing 52 and the closing member 4
A spring 53 for urging the valve housing 52 toward the other end of the housing 50 is contracted between the positions 9.

The differential pressure valve 46 is provided in a valve seat 52 provided in the valve housing 52 by opening a valve hole 55 leading to the fluid chamber 51 at the center in a valve chamber 54 formed in the valve housing 52 through the passage 41. A valve body 57 which can be seated on the valve body 56;
And a spring 58 for exerting a resilient force in a direction in which the valve chamber 7 is seated on the valve seat 56. The fluid pressure of the fluid chamber 51 communicating with the passage 44 is connected to the valve chamber 5 communicating with the passage 41.
The valve is opened as the fluid pressure becomes higher than a predetermined value by a predetermined value.

The cup seal 47 prevents the working fluid from flowing from the fluid chamber 51 to the passage 41. However, when the fluid pressure in the passage 41 becomes larger than the fluid pressure in the fluid chamber 51, the cup seal 47 separates the fluid from the fluid chamber 51. The valve is mounted on the outer periphery of the valve housing 52 so as to allow the working fluid to flow therethrough.

[0027] According to the differential pressure valve 46, the braking operation early, the fluid pressure to the fluid pressure transmission unit 4 _FL, 4 _FR, 4 bypass valve 23 in _R is closed in response to fluid pressure increase in the pilot chamber 34 The working fluid from the passage 44 to the passage 41 communicating with the input fluid pressure chamber 19 of the transmission units 4 _FL and 4 _FR is blocked. That is, in the initial stage of the braking operation, the fluid pressure transmission units 4 _FL ,
4 braking pressure to the input fluid pressure chamber 19 of _FR will act. When the braking operation force is released, the working fluid in the passage 41 is released to the reservoir R by the cup seal 47.

In FIGS. 4 and 5, the fluid pressure control device 2 comprises an auxiliary fluid pressure generating means 61 capable of generating a non-amplified fluid pressure corresponding to the braking operation force of the brake pedal 1, and the output of the fluid pressure supply source 3. Fluid pressure control valve 62 capable of controlling the pressure in accordance with the operation amount of brake pedal 1 and outputting the amplified fluid pressure
And

The housing 63 of the fluid pressure control device 2 comprises a large cylinder body 64 and a small cylinder body 65 fitted and fixed in the front end of the large cylinder body 64. In the large cylinder body 64, a cylinder hole 66, a fitting hole 67 having a diameter larger than the cylinder hole 66 and coaxially connected to the front end of the cylinder hole 66, and fitting with a diameter larger than the fitting hole 67. A screw hole 68 that is coaxially continuous with the front end of the joint hole 67 is provided. The small cylinder body 65 is provided with the cylinder hole 66 and the fitting hole 6.
At the front end, an engagement flange 65a that engages with the step 69 between the seven is formed in a cylindrical shape, and is fitted into the cylinder hole 66. In addition, the plug member 70 is fitted into the fitting hole 67, and by tightening the screw member 71 screwed into the screw hole 68, the engaging flange 65a is sandwiched between the plug member 70 and the step portion 69. The small cylinder body 65 is fixed in the large cylinder body 64. The small cylinder body 65 is provided with a small sliding hole 72 and a large sliding hole 73 coaxially connected to the rear end of the small sliding hole 72.

The fluid pressure control valve 62 has a spool 74 as a sliding member slidably fitted in a small sliding hole 72 of a small cylinder body 65. Small cylinder body 65 and plug member 7
A reaction force chamber 75 facing the front surface of the spool 74 is defined between 0, and the reaction force chamber 75 communicates with the passage 42. At the front end of the spool 74, a retaining ring 76 that abuts against the small cylinder body 65 and regulates the retreat limit of the spool 74 is fitted. Includes a spring 77 for urging the spool 74 rearward.
Is contracted.

A pressing piston 78, which is a component of the auxiliary fluid pressure generating means 61, is slidably fitted in the large sliding hole 73 of the small cylinder body 65. It is in contact with the rear end. Further, a release chamber 79 defined between the pressing piston 78 and the small cylinder body 65 is communicated with the reservoir R. Accordingly, a force toward the rear side acts on the spool 74 by the fluid pressure of the reaction force chamber 75 and the spring 77, and a force toward the front side by the pressing piston 78 acts. The position of the spool 74 in the small cylinder body 65 is determined by the balance.

The large cylinder body 64 and the small cylinder body 65, which cooperate to form the housing 63, have small sliding holes 72 spaced from the front side in the axial direction to the rear side.
An input port 80, an output port 81, and a release port 82 that are open to the inner surface are provided. The input port 80 communicates with a passage 83 that communicates with the fluid pressure supply source 3, and the output port 81 communicates with a passage 43. Reference numeral 82 communicates with the reservoir R via the release passage 40. Moreover, an annular recess 84 is provided on the outer periphery of the spool 74. The length of the annular recess 84 along the axis of the spool 74 is such that when the spool 74 is in the forward position, the output port 81 is input through the annular recess 84. When the spool 74 is in the retracted position, the output port 81 communicates with the release port 82 through the annular recess 84 and is disconnected from the input port 80 when the spool 74 is at the retracted position. ing.

The passage 4 leading to the output port 81
Between the passage 43 and the reaction chamber 75, the passage 43, that is, the fluid pressure on the output port 81 side becomes larger than the fluid pressure on the reaction chamber 75 by a predetermined value or more, from the passage 43 to the reaction chamber 75. And a differential pressure valve 85 that allows the flow of the working fluid, and the flow of the working fluid from the reaction chamber 75 to the passage 43 when the fluid pressure on the reaction chamber 75 side is slightly larger than the fluid pressure on the passage 43 side. A cup seal 86 that functions as a one-way valve that permits flow is provided.

Large cylinder body 64 in housing 63
Is provided with an introduction port 88 communicating with the passage 43. A differential pressure valve 85 is connected between the introduction port 88 and the reaction force chamber 75 to open and close a passage 89 provided in the plug member 70.
The differential pressure valve 85 is provided with a valve seat 90 that opens to a reaction chamber 75 through a passage 89, and a valve housed in the reaction chamber 75 so as to be able to seat on the valve seat 90. Body 91
And a spring 92 for urging the valve body 91 in a direction of sitting on the valve seat 90. The cup seal 86 is provided in the reaction force chamber 7.
5 is attached to the outer periphery of the plug member 70 while allowing the working fluid to flow from the inlet port 88 to the inlet port 88.

According to the differential pressure valve 85, no fluid pressure is generated in the reaction force chamber 75 until the fluid pressure output from the output port 81 of the fluid pressure control device 2 to the passage 43 reaches a certain value at the beginning of the braking operation. it allows as well as serves to increase the fluid pressure to a certain value that is output to the passage 43 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 fluid until the it is intended to suppress the fluid pressure output of the passage 42 leading to the input fluid pressure chamber 19 in the pressure transmission 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 42 acts on the input fluid pressure chamber 19 of the fluid pressure transmission unit 4 _R. The cup seal 86 functions to release the working fluid in the passage 42 from the passage 43 to the reservoir R via the output port 81, the annular concave portion 84, and the release port 82 when the braking operation force is released.

The auxiliary fluid pressure generating means 61 is operatively connected to the rear end of the spool 74 of the fluid pressure control valve 62, and is slidably fitted in the large sliding hole 73.
And an input piston 94 which is slidably fitted in the cylinder hole 66 with the front face facing a pressure chamber 93 defined between the rear face of the pressing piston 78 and being interlocked with and connected to the brake pedal 1. , A pair of springs 95 and 96 interposed in series between the pistons 78 and 94.

Large cylinder body 64 in housing 63
A restricting member 97 for restricting the retraction limit of the input piston 94 is fixed to the rear end opening, and a piston rod 98 that penetrates the restricting member 97 in a fluid-tight manner and movably penetrates the input piston 94 coaxially. Is established. On the other hand, a push rod 99 is connected to the brake pedal 1, and the front end of the push rod 99 is swingably connected to the piston rod 98. Therefore, the input piston 94 moves forward in the direction of reducing the volume of the pressure chamber 93 in response to the depression operation of the brake pedal 1.

A cup-shaped retainer 100 is fitted into the front end of the input piston 94, and a cylindrical retainer 101 with a bottom is in contact with the back surface of the pressing piston 78. A retainer 101 is provided between the retainers 100 and 101. A spring 95 having a guide member 102 slidably fitted to the spring 95 interposed therebetween.
96 is contracted. In addition, the rear end of the rod 103 movably penetrating the retainer 101 is engaged with the retainer 100 such that the retreat limit position with respect to the pressing piston 78 is regulated by the retainer 101. This regulates the maximum distance between the pressing piston 78 and the input piston 94. The spring 95 has a relatively large spring constant,
Are set relatively small.

A valve hole 104 provided in the input piston 94 through the reservoir R, a valve body 105 provided at the rear end of the rod 103, and a rod 103 biasing the rod 103 in a direction in which the valve body 105 closes the valve hole 104. A shut-off valve 107 for switching between communication and shut-off between the pressure chamber 93 and the reservoir R is constituted by the spring 103 provided between the rod 103 and the retainer 100, and the shut-off valve 107 is provided with a pressing piston 78 and an input. When the interval between the pistons 94 is maximum, the valve is opened to connect the pressure chamber 93 to the reservoir R. When the input piston 94 moves forward with respect to the rod 103 from this state, the valve closes to open the pressure chamber. Shut off between 93 and reservoir R.

In such a fluid pressure control device 2, the pressure receiving area A ₁ of the spool 74 facing the reaction force chamber 75 is smaller than the pressure receiving area A ₂ of the pressing piston 78 facing the pressure chamber 93. The pressure receiving area A ₃ of the input piston 94 is larger than the pressure receiving area A ₂ of the pressing piston 78. That is, A ₁ <A ₂ <A ₃ .

A passage 108 is connected to the pressure chamber 93 of the auxiliary fluid pressure generating means 61.
Is connected to the stroke accumulator 113.

Referring to FIG. 6, a stroke accumulator 113 includes a casing 114, an accumulator piston 116 which forms a pressure accumulating chamber 115 communicating with the passage 108 between the casing 114 and a sliding accumulator piston 116, and a fluid. A backup piston 118 that forms a pilot chamber 117 communicating with a passage 114 communicating with the pressure supply source 3 between the casing 114 and a backup piston 118 that firstly urges an accumulator piston 116 toward the side that reduces the volume of the accumulator chamber 115. The second accumulator spring 119,
120 and the backup piston 11 on the side of reducing the volume of the pilot chamber 117 by exerting a spring load larger than the spring load by the accumulator springs 119 and 120.
8 is provided.

The casing 114 has a first cylinder hole 122 closed at one end, and has a diameter larger than that of the first cylinder hole 122 and is coaxially connected to the other end of the first cylinder hole 122 via a step 124. The second cylinder hole 123 has a diameter larger than that of the second cylinder hole 123 and is larger than the second cylinder hole 12.
An open end of a stepped bottomed cylinder 127 having a third cylinder hole 125 whose one end is coaxially connected via a tapered step 126 to the other end of 3 is closed by a closing member 128.

The accumulator piston 116 forms a pressure accumulation chamber 115 with one end wall of the casing 114 and is slidably fitted in the first cylinder hole 122. The backup piston 118 defines a release chamber 129 communicating with the reservoir R between the backup piston 118 and the accumulator piston 116, and is slidably fitted in the second and third cylinder holes 123 and 125. A pilot chamber 117 communicating with the fluid pressure supply source 3 is provided between the inner surface of the third cylinder hole 125 and the outer surface of the backup piston 118.
Is defined.

The backup piston 118 is formed in a cylindrical shape, and a receiving flange 130 is provided at a front end thereof, that is, at a portion near the accumulator piston 116, to protrude inward in the radial direction.

First and second accumulator springs 11
Reference numerals 9 and 120 are provided in series between retainers 132 and 133 with a guide member 131 interposed therebetween. In the middle of the piston rod 134 coaxially connected to the accumulator piston 116, there is provided a flange portion 134a projecting outward in the radial direction.
2 is a piston rod 1 to be engaged with the collar 134a.
34 are formed in a disk shape. Also, retainer 13
Numeral 3 is formed in a bottomed cylindrical shape in which an open end is brought into contact with the closing member 128. Further, the guide member 131 is slidably fitted to the piston rod 134, and the first accumulator spring 119 is connected to the flange 1 of the piston rod 134.
The second accumulator spring 120 is provided between the retainer 132 and the guide member 131 engaged with the guide member 131 and the retainer 133 supported by the guide member 131 and the closing member 128.
It is arranged between. Thus, both accumulator springs 11
The load characteristics of the accumulator pistons 9 and 120 are such that the accumulator piston 116 is moved toward the side where the volume of the accumulator chamber 115 is increased while the accumulator piston 116 is moving.
They are set differently from each other such that the spring load characteristics biasing to the side change.

The backup spring 121 is provided in the release chamber 129.
Inside, it is contracted between the receiving flange 130 and the retainer 133 of the backup piston 118.

Such a stroke accumulator 11
3, when the fluid pressure supply source 3 is operating normally and normal fluid pressure from the fluid pressure supply source 3 is acting on the pilot chamber 117, as shown in FIG. It moves to the side that increases the volume of the pilot chamber 117 against the urging force of the spring 121, that is, the side that is separated 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,
The backup piston 118 is a backup spring 121
Due to the spring force of (1), the pilot chamber 117 moves to the side where the volume is reduced, that is, the side close to the accumulator piston 116, and the receiving flange 130 of the backup piston 118 contacts the retainer 132. Therefore, a large spring load of the backup spring 121 acts on the accumulator piston 116 instead of the first and second accumulator springs 119 and 120.

In the stroke accumulator 113, the accumulator piston 116 and the retainer 1
The maximum distance between the retainers 133 and the backup piston 118 is regulated by the engagement of the retainer 133 with the piston rod 134 connected to the accumulator piston 116, and the backup piston 118 is engaged with the accumulator piston 116. It is regulated by doing. That is, the flange 1 of the piston rod 134
The maximum interval between the retainer 133 and the backup piston 118 is regulated by the engagement of the backup piston 118 with the retainer 132 engaged with the retainer 132a.
Therefore, the accumulator piston 116, the retainer 132, the two accumulator springs 119 and 120, the retainer 133, the backup piston 118, and the backup spring 121 can be assembled separately from the casing 114 as an interior assembly. After the insertion into the bottomed cylindrical body 127, the assembly of the stroke accumulator 113 is completed only by attaching the closing member 128 to the bottomed cylindrical body 127, so that the workability of assembling the stroke accumulator 113 is improved.

Incidentally, the stroke accumulator 11
3, a differential pressure valve 136 that allows the working fluid to flow from the pressure accumulating chamber 115 to the passage 24 when the fluid pressure in the pressure accumulating chamber 115 becomes higher than the fluid pressure in the passage 24 by a predetermined value. As the pressure becomes higher than the fluid pressure in the pressure accumulating chamber 115, the cup seal 137 that functions as a one-way valve that permits the flow of the working fluid from the path 24 to the pressure accumulating chamber 115, and the path 24 are depressurized. And a cup seal 138 that functions as a one-way valve that permits the flow of the working fluid from the release chamber 129 that communicates with the reservoir R to the passage 24 when the hydraulic fluid flows.

An annular recess which forms an annular chamber 139 between the accumulator piston 116 and the inner surface of the first cylinder hole 122 of the casing 114 is provided on the outer periphery of the accumulator piston 116. 1
A connection hole 140 communicating with the connection hole 39 is formed.
Is connected to the passage 24. Therefore, the annular chamber 139 communicates with the passage 24.

The differential pressure valve 136 communicates with the annular chamber 139 and has a valve chamber 141 provided in the accumulator piston 116.
A valve body 144 having a valve hole 142 communicating with the accumulator chamber 115 is opened at the center, and a valve body 144 facing the inside of the valve chamber 141 and capable of being seated on a valve seat 143 provided in the accumulator piston 116. 143 and a spring 145 which exerts a resilient force in a direction to be seated on are those, which are accommodated, each of the fluid pressure transmission unit 4 _FL, 4 _FR, 4 the valve chamber 33 of the bypass valve 23 in the _R channel 24 and annular Room 1
The fluid pressure in the valve chamber 141 communicating via
The valve is opened when the fluid pressure is lower than the fluid pressure of
Fifteen fluid pressures are applied to the fluid pressure transmission units 4 _FL , 4 _FR ,
4 and serves to act on the valve chamber 33 of the _R.

The cup seal 137 has an annular chamber 139.
And an accumulator piston 116
The cup seal 138 is attached to the outer periphery of the annular chamber 13.
9 and the release chamber 129 between the accumulator piston 11
6 is attached to the outer periphery.

According to the differential pressure valve 136, the auxiliary pressure is maintained until the fluid pressure generated in the pressure chamber 93 of the auxiliary fluid pressure generating means 61 in the fluid pressure control device 2 in accordance with the braking operation of the brake pedal 1 becomes a certain value or more. The output pressure of the fluid pressure generating means 61 is prevented from acting on the valve chamber 33 of the bypass valve 23 in each of the fluid pressure transmission units 4 _FL , 4 _FR , 4 _R , and the bypass valve 23 increases the pilot pressure of the pilot chamber 34. After the valve is closed accordingly, the differential pressure valve 136 can be opened. In addition, the breathing of the passage 24 due to the advancement of the brake piston or the temperature change due to the wear of the brake pad in each of the brake devices B _FL , B _FR , B _RL , and B _RR is performed via the cup seal 137 when the pressure increases, and the cup when the pressure decreases. This is possible through the seal 138.

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 , and 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 43 for guiding the amplified fluid pressure from the output port 81 of the fluid pressure control device 2
_FL, 4 _FR, 4 to the pilot chamber 34 of the bypass valve 23 in the _R communicates via a passage 44, also to the input fluid pressure chamber 19 of the fluid pressure transmission unit 4 _FL, 4 _FR via the differential pressure valve 46 and the passage 41 with a connected state, the differential pressure valve 85 is in the connected state to the input fluid pressure chamber 19 of the fluid pressure transmission unit 4 _R through the reaction chamber 75 and the passage 42.

When the brake pedal 1 is depressed in this state,
In the fluid pressure control device 2, the input piston 94 moves forward and applies a forward force to the pressing piston 78 via the springs 95 and 96, whereby the spool 74 of the fluid pressure control valve 62 moves forward while reducing the spring 77. .

The spool 74 advances to a position where the input port 80 communicates with the output port 81 and is cut off from the release port 82, and the spool 74 is operated by the differential pressure valve 85 until the output pressure of the passage 43 reaches a certain value. No fluid pressure in the power chamber 75, that is, fluid pressure for urging the spool 74 in the backward direction, is generated, and a fluid pressure that rapidly increases is output to the passage 43 at the beginning of the braking operation. Thereby, each fluid pressure transmission unit 4
_FL, 4 _FR, 4 bypass valve 23 is closed in _R, then the fluid pressure transmission unit 4 by opening of the differential pressure valve 46 _FL, 4
With the respective fluid pressure from the passage 41 to the input fluid pressure chamber 19 of the _FR acts, the fluid pressure will act from the passage 42 to the input fluid pressure chamber 19 of the fluid pressure transmission unit 4 _R by opening of the differential pressure valve 85 .

In the fluid pressure control valve 62, the spring 7
7, and the force in the retreating direction, which is the sum of the force obtained by multiplying the cross-sectional area of the spool 74 by the fluid pressure of the reaction force chamber 75,
When the spring load of the springs 95 and 96 becomes larger, the spring 9
The input piston 94 moves forward with respect to the pressing piston 78 while reducing the pressure of the pressure chambers 5 and 96, the shutoff valve 107 is closed, the pressure chamber 93 is shut off from the reservoir R, and the volume of the pressure chamber 93 is reduced. Fluid pressure is generated in the reaction chamber 93.

Therefore, although the pressure accumulating chamber 115 of the stroke accumulator 113 for securing the operation stroke is communicated with the pressure chamber 93, the initial operation stroke is absorbed by the stroke accumulator 113 and becomes an invalid stroke. Nor.

Thereafter, the fluid pressure in the pressure chamber 93 is accumulated in the accumulator chamber 115 of the stroke accumulator 113, and the input piston 94 is acted upon by the operating force opposing the urging force of the accumulator springs 119 and 120 acting on the accumulator piston 116. Is further advanced, and an operation stroke can be secured by the stroke accumulator 113.

After the fluid pressure is generated in the pressure chamber 93, the fluid pressure is controlled.
The spool 74 of the valve 62 retreats from the reaction chamber 75 side
In the forward direction and the force in the forward direction from the pressure chamber 93 side are balanced
Back and forth so that the fluid pressure source 3
The output pressure is controlled, and the fluid pressure control device 2
The amplified fluid pressure corresponding to the operation amount of the rake pedal 1 is output.
And each brake device B_FL, B_FR, B_RL, B_RRWith amplification fluid
A braking force by pressure is obtained. Thus, hydraulic transmission
Unit 4_FL, 4_FR, 4_RBy the free piston 21
Therefore, the fluid pressure circuit on the fluid pressure supply source 3 side and each brake device
Place B_FL, B_FR, B _RL, B_RRBetween the
Gases that may enter the working fluid on the body pressure supply source 3 side
Is each brake device B_FL, B_FR, B_RL, B_RRAdversely affect
Blurring is prevented.

When a fluid pressure is generated in the reaction force chamber 75 and the spool 74 is connected to the output port 81 and the input port 8.
When the input piston 94 is further advanced by further operating the brake pedal 1 in a state in which the time interval 0 is shut off, the pressure receiving area A ₂ facing the pressure chamber 93 of the pressing piston 78.
Is smaller than the pressure receiving area A ₃ facing the pressure chamber 93 of the input piston 94 (A ₂ <A ₃ ), so that the advance amount of the pressing piston 78, that is, the spool 74 is larger than the advance amount of the input piston 94. Port 80 and output port 8
The operating force required to advance the spool 74 until the connection between the spools is made relatively small.

At the time of such braking, when the pedaling force of the brake pedal 1 becomes excessive and the wheels are likely to be locked, the inflow valve 6 corresponding to the wheels which are about to be locked.
_FL, 6 to excite the _FR, 6 _R, passage 41 and the fluid pressure transmission unit 4 _FL, 4 _FR between, as well as to block between passage 42 and the 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.

When such anti-lock control is executed, the spool 74 slides back and forth in accordance with the fluctuation of the fluid pressure in the reaction chamber 75, and the pressure receiving area A _{1 of the} spool 74 facing the reaction chamber 75 and the pressure chamber Since there is a relationship of A ₁ <A ₂ <A ₃ between the pressure receiving area A ₂ of the pressing piston 78 facing the 93 and the pressure receiving area A ₃ of the input piston 94 facing the pressure chamber 93, the front and rear of the spool 74 Fluctuation in the volume of the pressure chamber 93 due to sliding is relatively small, and therefore kickback acting on the brake pedal 1 due to fluctuation in the fluid pressure in the reaction force chamber 75 can be suppressed to a relatively small value.

It is assumed that the output pressure of the fluid pressure supply source 3 drops abnormally due to a failure of the fluid pressure pump 10 or the like during the braking. In this case, each of the fluid pressure transmission units 4 according to a decrease in the fluid pressure output from the fluid pressure control device 2 to the passage 43.
_FL, 4 _FR, 4 bypass valve 23 in _R is opened, respectively. Accordingly, the fluid pressure generated in the pressure chamber 93 in response to the forward operation of the input piston 94 by the depression operation of the brake pedal 1 is transmitted through the passage 108, the differential pressure valve 136, the annular chamber 139, and the passage 24 to the fluid pressure transmission units 4 _FL and 4 _FL . _{It is} supplied from the bypass valve 23 of the _{FR to} the brake devices B _FL and B _FR for the front wheels, respectively, and to the brake devices B _RL and B _RR for the rear wheels via the bypass valve 23 and the proportional pressure reducing valve 5 of the fluid pressure transmission unit 4 _R. Will be given. Therefore, even when the output pressure of the fluid pressure supply source 3 is abnormally reduced,
The fluid pressure generated in the pressure chamber 93 of the auxiliary fluid pressure generating means 61 can act on each of the brake devices _BFL , _BFR , _BRL , and _BRR . Since moreover the pressure receiving area A ₂ of the pressure piston 78 facing the pressure chamber 93 is smaller than the pressure receiving area A ₃ of the input piston 94 facing the pressure chamber 93, the pressure piston 7
The change in the volume of the pressure chamber 93 accompanying the forward movement of the brake pedal 8 can be made relatively small, and the ineffective stroke of the brake pedal 1 can be reduced.

At this time, the stroke accumulator 113
In this case, the fluid pressure in the pilot chamber 117 decreases abnormally with the decrease in the output fluid pressure of the fluid pressure supply source 3, whereby the backup piston 118 operates forward and the retainer 132
, And the retainer 132 further moves the piston rod 1
By contacting the flange portion 134a of the 34, the backup spring 121 having a large spring load acts on the accumulator piston 116. Therefore, when the output fluid pressure of the fluid pressure supply source 3 is abnormally reduced, the fluid pressure generated in the pressure chamber 93 is not unnecessarily consumed by the stroke accumulator 113, and the depressing stroke of the brake pedal 1 becomes larger than necessary. Never.

In the auxiliary fluid pressure generating means 61 of the fluid pressure control device 2, a spring 95 having a large spring load and a spring 96 having a small spring load are interposed between the input piston 94 and the pressing piston 78 in series. Have been. Therefore, the spring reaction force with respect to the stroke of the input piston 94 is as shown in FIG. That is, the input piston 94
There spring reaction force from the start of forward until it reaches the stroke amount S _A increases gradually to reach a predetermined value P _A, the stroke when exceeds the stroke amount S _A spring reaction force of the input piston 94 suddenly increases . In this way, when a failure occurs in the fluid pressure system communicating with the pressure chamber 93 in a state where the output pressure of the fluid pressure supply source 3 is normal, a relatively large spring reaction force is applied to the input piston 94 by applying a relatively large spring reaction force. pedal stroke increases in the brake pedal 1 is suppressed to a degree that exceeds slightly the stroke amount S _a, and the pressure chamber 93
The leading when the output pressure of the fluid pressure system is normal fluid pressure source 3 is abnormally low, the input piston 94 a predetermined value the spring reaction increased acting on the brake pedal 1 from P _A
Slightly more than

Further, when the braking force is not applied,
When the drive wheels are about to slip excessively,
Normally open solenoid valve 8 for traction control and normally closed solenoid
Valve 9 is energized. As a result, the output flow of the fluid pressure
Body pressure is fluid pressure transmission unit 4 _FL, 4_FRInput fluid pressure chamber 1
9 which acts on the left and right front wheels as drive wheels
B _FL, B_FRBraking force and excessive slip
Evaded. After this, the same as for the antilock control described above
And the inflow valve 6_FL, 6_FRAnd outflow valve 7_FL, 7_FRExcitation
The braking force can be controlled by the demagnetization control.

In this brake pressure control device, at the beginning of the braking operation, the fluid pressure is not applied to the reaction force chamber 75 until the fluid pressure output from the output port 81 of the fluid pressure control device 2 reaches a certain value. I.e. brake pedal 1
Differential pressure valve 85 for preventing operation reaction force from acting on
Is provided in the plug member 70, which is a component of the fluid pressure control device 2, so that the configuration can be made compact.

Each fluid pressure transmission unit 4 _FL , 4 _FR , 4
The respiratory action of the output fluid pressure chamber 20 at _R can be achieved by a seal member 28 mounted on the outer periphery of the free piston 21, and the passage 2 communicating with the valve chamber 33 of each bypass valve 23.
4 can be performed by the cup seals 137 and 138 mounted on the outer circumference of the accumulator piston 116 in the stroke accumulator 113, so that the one-way valve for generating the respiration action is connected to the free piston 2
1 and the accumulator piston 116 can be organically integrated into a compact configuration.
Further, the accumulator piston 116 has a pressure chamber 93.
Since the differential pressure valve 136 for preventing the fluid pressure in the pressure chamber 93 from acting on the bypass valve 23 until the pressure becomes equal to or higher than the predetermined value, a more compact configuration can be achieved.

The present invention is not limited to a vehicle brake pressure control 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 response to the depression operation of the brake pedal 1. The present invention can be widely applied in connection with a fluid pressure control device capable of adjusting the output pressure of a fluid pressure supply source capable of outputting a constant fluid pressure in accordance with the operation amount of an operation member to enable output.

[0072]

As described above, according to the first aspect of the present invention, the pressure receiving area of the pressure piston facing the pressure chamber is set smaller than the pressure receiving area of the input piston facing the pressure chamber. Even if the fluid pressure fluctuates, the change in the volume of the pressure chamber due to the sliding of the sliding member back and forth is relatively small to suppress kickback, and the sliding member is in a state where fluid pressure is generated in the reaction force chamber. Can be made relatively small.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the pressure chamber is provided with a fluid through a bypass valve which closes in response to an increase in output pressure from an output port. Since it is connected to the pressure device, it is possible to secure a fluid pressure for driving the fluid pressure device when the output pressure of the fluid pressure supply source is abnormally reduced, and to reduce an invalid stroke at that time. .

[Brief description of the drawings]

FIG. 1 is a fluid pressure circuit diagram of a brake pressure control device.

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

FIG. 3 is a vertical cross-sectional view of a flow control unit.

FIG. 4 is a longitudinal sectional view showing a partial configuration of a fluid pressure control device.

FIG. 5 is a longitudinal sectional view showing the remaining configuration of the fluid pressure control device.

FIG. 6 is a longitudinal sectional view showing a configuration of a stroke accumulator.

FIG. 7 is a diagram showing a relationship between an input piston stroke and a spring reaction force in the auxiliary fluid pressure generating means.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Brake pedal as an operating member 2 ... Fluid pressure control device 3 ... Fluid pressure supply source 23 ... Bypass valve 63 ... Housing 74 ... Spool as a sliding member 75 ...・ Reaction force chamber 78 ・ ・ ・ Pressing piston 80 ・ ・ ・ Input port 81 ・ ・ ・ Output port 82 ・ ・ ・ Release port 93 ・ ・ ・ Pressure chamber 94 ・ ・ ・ Input piston A ₁ , A ₂ , A _3.・ Pressure receiving area B _FL , B _FR , B _RL , B _RR・ ・ ・ Brake device as fluid pressure device R ・ ・ ・ Reservoir

Continuation of the front page (72) Inventor Masaaki Naei 1-4-1 Chuo, Wako-shi, Saitama Prefecture Honda R & D Co., Ltd. (56) References JP-A-3-220054 (JP, A) JP-A-3-3 16861 (JP, A) JP-A-61-139547 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60T 13/12

Claims (2)

(57) [Claims] An input port (80) connected to a fluid pressure supply (3), a fluid pressure device (B _FL , B _FR , B _RL ,
B _RR ), and a housing (63) having an output port (82) connected to the reservoir (R), and communication between the output port (81) and the release port (82). A sliding member (74) slidably fitted to the housing (63) between a retracted position and a forward position communicating between the output port (81) and the input port (80); Sliding member (74) for generating a fluid pressure for urging (74) in the backward direction;
The reaction force chamber (7) formed in the housing (63) facing the front surface of the power port and connected to the output port (81).
5), a pressing piston (78) slidably fitted to the housing (63) and interlocked and connected to the rear end of the sliding member (74), and slidably fitted to the housing (63). The input piston (9
4) and a pressure receiving area (93) formed between the rear surface of the pressing piston (78) and the front surface of the input piston (94), and faces the reaction force chamber (75) of the sliding member (74). In the fluid pressure control device in which (A ₁ ) is set smaller than the pressure receiving area (A ₂ ) facing the pressure chamber (93) of the pressing piston (78), the pressure chamber (93) of the pressing piston (78)
A pressure receiving area (A ₂ ) facing the pressure chamber (93) of the input piston (94) is set smaller than a pressure receiving area (A ₃ ) facing the pressure chamber (93) of the input piston (94). 2. The pressure chamber (93) has an output port (8).
The bypass valve (2) that closes according to the output pressure increase from 1)
3) via the fluid pressure device (B_FL, B_FR, B _RL,B_RR)
The fluid pressure control according to claim 1, wherein the fluid pressure control is connected to
Control device.