JP2001158340A - Hydraulic brake device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic brake device for a vehicle capable of conveying a suitable pedal operating feel to the driver. SOLUTION: The pressure of brake fluid in a control chamber is built up by the advance of a control piston 33 (spool valve 35), and hydraulic pressure within a power chamber adds an assisting force to the force of operating a brake pedal 10. According to the assisting force, brake fluid in a pressure chamber is compressed to output the brake hydraulic pressure. When the hydraulic pressure of the brake fluid in the control chamber is greater than a predetermined pressure, a reaction disc 39 is elastically deformed by hydraulic pressure within a reaction chamber R5 to cause sliding movement of a reaction rod 38 to vary the balance of forces acting on the control piston 33 so as to reduce the gradient of pressure buildup of the brake fluid within the control chamber R4 and also to reduce the assisting force for the force of operating the brake pedal 10, the assisting force being produced by the hydraulic pressure within the power chamber R1. The reaction rod 38 is positioned within a rod compartment 38 so as to be always brought into abutting relation with the reaction disc 39 by the energizing force of a coil spring 90.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic brake device for a vehicle, and more particularly, to a hydraulic brake device for a vehicle which outputs a brake hydraulic pressure by applying an assisting force to the depression force of a brake pedal.

[0002]

2. Description of the Related Art Conventionally, as a hydraulic brake device for a vehicle, for example, one described in Japanese Patent Application Laid-Open No. 11-34852 is known. In the vehicle hydraulic brake device described in the publication, a master piston that is drivingly connected to a brake pedal, a control piston that is interlocked with the master piston, a spool valve that switches a brake fluid flow path in conjunction with the control piston, A reaction force disk that elastically deforms in response to pressure and a reaction force rod that slides toward the spool valve based on the elastic deformation of the reaction force disk are housed in the cylinder body. In the cylinder body, a power chamber, a pressure chamber, a control chamber, and a reaction chamber are separately formed.

In this hydraulic brake system, when the master piston moves forward with the operation of the brake pedal, the control piston and the spool valve move forward in conjunction with each other. At this time, the communication between the control chamber and the reservoir is cut off by the spool valve,
The control chamber communicates with the auxiliary hydraulic pressure source, and the brake fluid in the control chamber is boosted. Then, an assisting force is applied to the depression force of the brake pedal by the fluid pressure in the power chamber introduced from the control chamber, and the brake fluid in the pressure chamber is compressed according to the assisting force to output the brake fluid pressure. Then, as shown by a solid line in FIG. 8, a first-stage brake fluid pressure characteristic corresponding to the depression force of the brake pedal is obtained.

On the other hand, when the pressure of the brake fluid in the control chamber is higher than a predetermined pressure, the reaction disk is elastically deformed by the pressure of the reaction chamber introduced from the control chamber, and the reaction rod is slid. And push the spool valve back through it. Due to this reaction force, the balance of the force acting on the control piston changes, and the pressure increase gradient of the brake fluid in the control room decreases. Then, the assisting force of the depression force of the brake pedal due to the hydraulic pressure in the power room introduced from the control room is reduced, and as shown by the solid line in FIG. 8, a second stage corresponding to the depression force of the brake pedal is performed. Brake fluid pressure characteristics are obtained.

[0005] The first brake pedal corresponding to the depression force of these brake pedals
The pedal operation feeling is made favorable by the brake fluid pressure characteristics of the second stage.

[0006]

In this hydraulic brake system, the reaction force rod is only slidably supported in the cylinder body between the reaction force disk and the spool valve. Accordingly, the relative positions of the reaction force disk and the reaction force rod when the elastic deformation of the reaction force disk starts are different each time. When the deformation of the reaction force disk changes due to the relative position of the reaction force disk and the reaction force rod, the reaction force chamber at the time when the spool valve starts to be pushed back through the reaction force rod. 8 may change, and FIG.
As shown by the one-dot chain line, the brake pedal pressure (point S) when shifting to the second-stage brake fluid pressure characteristic may shift. Such a shift in the pedaling force when shifting to the second-stage brake fluid pressure characteristic is transmitted to the driver as an uncomfortable feeling of the pedal operation.

An object of the present invention is to provide a vehicle hydraulic brake device capable of transmitting a favorable pedal operation feeling to a driver.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, an invention according to claim 1 includes a master piston drivingly connected to a brake pedal, a control piston interlocked with the master piston, and a control piston. A spool valve that switches the flow path of the brake fluid in conjunction with it, a reaction disk that elastically deforms according to the hydraulic pressure, and a reaction rod that slides toward the spool valve based on the elastic deformation of the reaction disk inside the cylinder body. And a power chamber, a pressure chamber, a control chamber, and a reaction force chamber are separately formed, and a brake is provided so as to increase the pressure of the brake fluid in the control chamber by interlocking the spool valve with one side movement of the control piston. The liquid flow path is switched, and an assisting force is applied to the depressing force of the brake pedal by the hydraulic pressure in the power chamber introduced from the control chamber, thereby responding to the assisting force. And compressing the brake fluid in the pressure chamber to output a brake fluid pressure. On the other hand, when the fluid pressure in the reaction force chamber is greater than a predetermined pressure, the elastic deformation of the reaction force disc due to the fluid pressure in the reaction force chamber A force acting on the control piston by applying a reaction force that pushes the spool valve back to the other side via the reaction force transmitting means by pressing the reaction force transmission means and sliding the reaction force transmission means. Of the vehicle to reduce the pressure gradient of the brake fluid in the control room, and to reduce the assisting force of the brake pedal by the hydraulic pressure in the power room introduced from the control room. The gist of the brake device is that the brake device further includes holding means for holding a relative position along a sliding direction between the reaction force disk and the reaction force rod when the reaction force disk is in an original state.

According to a second aspect of the present invention, in the vehicle hydraulic brake device according to the first aspect, the holding means includes:
An immovable portion disposed opposite to the reaction force rod on the opposite side of the reaction force disc with respect to the reaction force rod, and biasing means interposed between the reaction force rod and the immovable portion; The gist of the present invention is that the reaction force rod is urged by the urging means so as to come into contact with the reaction force disk.

According to a third aspect of the present invention, in the vehicle hydraulic brake device according to the second aspect, the reaction rod includes a fitting means for fitting with the urging means. And

The invention according to claim 4 is the invention according to claim 2 or 3.
In the vehicle hydraulic brake device according to the above, the gist is that the immovable portion is integrally formed with a cylinder that slidably supports the spool valve.

According to the first and second aspects of the present invention, when the reaction force disk is in the original state, the relative position of the reaction force disk and the reaction force rod along the sliding direction is maintained. Held by means. Therefore, the deformation of the reaction force disc is prevented from changing due to the relative position, and the hydraulic pressure in the reaction force chamber when the spool valve starts to be pushed back through the reaction force rod is also stabilized. Is done. That is, since the state in which the assisting force of the depression force of the brake pedal starts to be reduced is stabilized, a favorable pedal operation feeling is transmitted to the driver.

According to the third aspect of the present invention, the reaction rod has a fitting means for fitting with the urging means. Therefore, the urging means is stably connected to the reaction force rod, and its operation is also stabilized.

According to the fourth aspect of the present invention, the immovable portion is formed integrally with a cylinder that slidably supports the spool valve. Therefore, an increase in the number of parts is suppressed to a minimum.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a hydraulic brake system for a vehicle embodying the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view showing the hydraulic brake device. As shown in FIG. 1, the hydraulic brake device generates a required hydraulic pressure by a push rod 11 connected to a brake pedal 10 and a movement of the push rod 11 in accordance with the operation of the brake pedal 10. A hydraulic control cylinder 12, a brake fluid reservoir 13 in which brake fluid is stored, an auxiliary hydraulic pressure source 14 for generating high-pressure (power hydraulic) brake fluid, each front wheel 15 and each rear wheel 16 of the vehicle (FIG. 1 is provided with wheel cylinders 17 and 18 respectively provided on each of them (only one is shown).

A cylinder body 21 forming the external shape of the hydraulic control cylinder 12 penetrates along its axis, and corresponds from one side (right side in FIG. 1) corresponding to the rear side of the vehicle to the front side. To the other side (left side in FIG. 1),
A first hole 21a, a second hole 21b smaller in diameter than the first hole 21a, and a third hole 2 smaller in diameter than the second hole 21b
1c and a stepped fourth hole 21d are formed.
In the cylinder body 21, a hydraulic passage 22 communicating the rear part of the second hole 21b and the fourth hole 21d, a front part of the second hole 21b, and the brake fluid reservoir 13 are provided on the upper side of FIG. The hydraulic pressure path 23 which communicates with the hydraulic pressure path 2 which communicates the substantially middle portion of the fourth hole 21d with the brake fluid reservoir 13.
1, a hydraulic passage 25 communicating the rear of the second hole 21b with the wheel cylinder 18, a hydraulic passage 26 communicating the rear of the third hole 21c with the wheel cylinder 17, A hydraulic path 27 communicating between the front part and the rear part of the fourth hole 21d, and a hydraulic path 28 communicating a substantially middle part of the fourth hole 21d and the auxiliary hydraulic pressure source 14 are formed. In addition, as shown in FIG.
The spaces 5 are communicated with each other by a peripheral groove 29 formed in the second hole 21b corresponding to the opening. As shown in FIG. 3, the hydraulic passages 22 and 27 communicate with each other by a circumferential groove 30 formed in the fourth hole 21d corresponding to the opening.

The hydraulic pressure control cylinder 12 includes a master piston 31, a valve body 32, and a control piston 3 housed in the first to fourth holes 21a to 21d of the cylinder body 21.
3, a spool cylinder 34, a spool valve 35, a plunger 36, a sleeve 37, a reaction rod 38, a reaction disk 39, and a plug 40.

The master piston 31 has a first piston 41 and a second piston 42. As shown in FIG. 2, the first piston 41 is connected to the second hole 21.
b having a slightly smaller outer diameter than the inner diameter of the second hole 21.
b, and a cylindrical portion 44 having a diameter smaller than that of the disk portion 43 and projecting toward the first hole 21a. The first piston 41 is provided between the first hole 21a and the cylindrical portion 44 and has a substantially cylindrical sleeve 45 provided with a seal member. The first piston 41 is provided between the second hole 21b and the disk portion 43. The first and second holes 21a and 21b are slidably supported in a liquid-tight manner by the annular seal member 43a. The inner peripheral surface of the first hole 21a, the boundary surface between the first and second holes 21a and 21b,
A space formed by the outer peripheral surface and the boundary surface of the cylindrical member 3 and the cylindrical portion 44, the front end surface of the sleeve 45, and the like is a power chamber R1. The power chamber R1 is connected to the peripheral groove 29 (the hydraulic passages 22, 25) via a clearance C1 formed between the inner peripheral surface of the second hole 21b and the outer peripheral surface of the disk portion 43.
Is in communication with

A transmission member 46 connected to the end of the push rod 11 inserted in the cylindrical portion 44 is mounted inside the cylindrical portion 44. This transmission member 46
The bolt 46a is fastened to a contact member 47 that penetrates the disk 43 along the axis at the bolt portion 46a and protrudes toward the second piston 42. Accordingly, the first piston 41, the transmission member 46, and the contact member 47 are integrally connected, and as shown in FIG. 2, when the push rod 11 moves forward based on the operation of the brake pedal 10, it is integrated. Move. Since the volume of the power chamber R1 is expanded as the first piston 41 advances, more brake fluid flows into the power chamber R1.

The second piston 42 is accommodated on the front side (left side in FIG. 1) of the first piston 41 (disk portion 43) with a slight gap. As shown in FIG. 2, the second piston 42 is formed in a substantially cylindrical body, and has an outer diameter slightly smaller than the inner diameter of the second hole 21b and the third hole 21c at the rear and front portions. Have the second
A first flange 42a and a second flange 42b are respectively formed at the rear portions of the third holes 21b and 21c. The second piston 42 is slidably supported by the first and second flanges 42a and 42b with respect to the second and third holes 21b and 21c, respectively.

A recess 48 is formed at the rear of the second piston 42 so as to face the contact member 47 and to contact the contact member 47. Therefore, as shown in FIG. 2, when the first piston 41 (push rod 11) moves forward, the second piston 42 is pressed by the contact member 47 in the concave portion 48 and moves.

Further, a substantially cylindrical valve body support portion 52 whose diameter is reduced through a step portion 51 is formed to extend in front of the second piston 42. The valve body 32 is accommodated in the valve body support portion 52.

Here, the first and second flanges 42 are provided.
a and 42b between the inner peripheral surface of the second hole 21b and the second hole 21b.
The space formed by the outer peripheral surface of the piston 42 is a liquid supply chamber R2. The liquid supply chamber R2 is provided with the disk portion 43.
The power chamber R is provided by a seal member 43a attached to the power chamber R.
1 and separated. Further, the liquid supply chamber R2 communicates with the brake fluid reservoir 13 via the hydraulic path 23. As shown in FIG. 2, the second piston 42 has a through hole 53 penetrating in a meridian direction corresponding to the liquid supply chamber R2, and a valve body supporting portion 52 penetrating in the axial direction. A communication passage 54 communicating with the through hole 53 is formed. Therefore, the hollow portion of the valve body support portion 52 communicates with the liquid supply chamber R2 through the communication passage 54 and the through hole 53.

The second piston 42 is provided with an annular cup-shaped sealing member 55 that is folded forward at the step 51. This sealing member 55
The brake fluid in the supply chamber R2 is filled with the third hole 21c.
Through the clearance C2 formed between the inner peripheral surface of the second flange 42b and the outer peripheral surface of the second flange 42b, and allows the brake fluid at the front to flow into the same through the clearance C2. It has a function as a check valve for inhibiting the inflow into the chamber R2.

The valve body 32 is housed in the valve body support portion 52 and is locked by a retainer 56 fitted on the outer peripheral portion of the valve body support portion 52. An elastic body made of rubber, for example, is attached to the rear end of the valve body 32.
When the second member 2 comes into contact with the second piston 42 (the opening of the communication passage 54), the hollow portion of the valve body supporting portion 52 and the communication passage 54 are shut off. Therefore, when the second piston 42 moves forward and is pressed by the valve body 32, the communication between the liquid supply chamber R <b> 2 and the hollow portion of the valve body support 52 is interrupted by the valve body 32.

The front end of the valve body 32 has a rod 5
7 are integrally formed, and as shown in FIG. 3, a locking portion 57a is formed at the distal end thereof. The control piston 33 is accommodated in the third hole 21c in front of the master piston 31. As shown in FIG. 3, a third portion having an outer diameter slightly smaller than the inner diameter of the third hole 21c is provided at a substantially intermediate portion of the control piston 33.
A flange 58 is formed, a first cylindrical portion 59 having an outer diameter slightly smaller than the inner diameter of the third hole 21c at the front portion of the control piston 33, and an inner diameter at the front side of the first cylindrical portion 59. The enlarged second cylindrical portions 60 are formed. The control piston 33 is slidably fitted to the third hole 21c by the third flange 58 and the first and second cylindrical portions 59 and 60, and is mounted on the outer peripheral surface of the first cylindrical portion 59. It is liquid-tightly supported by the annular seal member 59a. Incidentally, the third flange 58 communicates in the axial direction.

The space formed between the master piston 31 (second piston 42) and the control piston 33 in the third hole 21c is a pressure chamber R3. The pressure chamber R3 is substantially separated from the liquid supply chamber R2 by a seal member 55 mounted on the second piston 42.

As shown in FIG. 3, the control piston 33 has a through hole extending in the axial direction, opening at the rear end, and radially penetrating between the third flange 58 and the first cylindrical portion 59. 61 are formed. The through hole 61 accommodates the locking portion 57a of the valve body 32. The locking portion 57a is locked to a retainer 62 fitted to a rear portion of the control piston 33.

The retainer 56 fitted to the valve body support 52 of the second piston 42 and the control piston 3
A spring 63 is interposed between the retainer 62 and the retainer 62 fitted to the rear portion of the spring 3. Therefore, as shown in FIG. 3, when the master piston 31 (the second piston 42) advances, the control piston 33 advances integrally via the spring 63.

At the rear of the first cylindrical portion 59, a locking pin 64 protruding in the radial direction is fixed to the cylinder body 21. Therefore, the movement range of the control piston 33 is restricted between the third flange 58 and the first cylindrical portion 59.

Here, the hydraulic passage 26 is opened in the third hole 21c corresponding to the position of the locking pin 64. Therefore, the pressure chamber R3 and the wheel cylinder 17 communicate with each other through the hydraulic path 26.

The spool cylinder 34 is fitted to the front side of the control piston 33 in the fourth hole 21d. The spool cylinder 34 is provided with the third hole 2
The control piston 33 is formed in a substantially cylindrical shape with an outer diameter slightly smaller than the inner diameter and an inner diameter slightly smaller than the inner diameter of the first cylindrical portion 59 of the control piston 33. An annular first sealing member 34a, a second sealing member 34b, and a third sealing member 34c are mounted on the outer peripheral surface of the spool cylinder 34, and are fixed to the fourth hole 21d in a liquid-tight manner. I have.

At the rear end of the spool cylinder 34, there is formed a cylindrical portion 65 whose outer peripheral surface is reduced in diameter and protrudes. As shown in FIG. 4, a peripheral groove 66 is formed on the inner peripheral surface in front of the base end of the cylindrical portion 65. On the other hand, at the front end of the spool cylinder 34, an annular inward flange 67a is formed as a stationary part.
At the front end of the spool cylinder 34, a cylindrical portion 67 protruding forward is formed. A through hole 68 is formed in the cylindrical portion 67 so as to penetrate in the radial direction corresponding to the opening of the hydraulic path 24. This through hole 6
8 corresponds to the fourth hole 21d corresponding to the opening of the hydraulic passage 24.
The hollow portion of the cylindrical portion 67 communicates with the brake fluid reservoir 13 through the through hole 68, the circumferential groove 69, and the hydraulic passage 24.

The first and second sealing members 3
4a, 34b, the second and third sealing members 34
A first communication hole 70 and a second communication hole 71 penetrating in the radial direction are formed between b and 34c, respectively. One end of the spool cylinder 34 extends in the axial direction and communicates with the second communication hole 71, and the other end of the spool cylinder 34 has the third hole 2.
A third communication hole 72 that opens to the side 1c is formed. The first communication hole 70 communicates with the peripheral groove 73 formed in the fourth hole 21d corresponding to the opening of the hydraulic passage 28, and accordingly, the peripheral groove 73 and the hydraulic passage 28 Through the auxiliary hydraulic pressure source 14.

The spool valve 35 has a rear portion and a front portion each having a first cylindrical portion 59 of the control piston 33.
Has an outer diameter slightly smaller than the inner diameter of the spool cylinder 34 and an outer diameter slightly smaller than the inner diameter of the spool cylinder 34. The inner diameter of the hollow portion formed on the front side of the spool valve 35 is the same as that of the inward flange 67.
It is set smaller than the inner diameter of a. The rear part of the spool valve 35 is mounted in a liquid-tight manner on the first cylindrical part 59 and is locked to the control piston 33. More specifically, a retainer 74 is fitted on the inner wall surface of the first cylindrical portion 59, and a spring 75 is interposed between the retainer 74 and the spool cylinder. The spool valve 35 is biased by the spring 75 so as to contact the control piston 33. The front of the spool valve 35 is connected to the inward flange 67a with respect to the spool cylinder 34.
It is slidably supported in the range up to.

Here, the fourth hole 21d, the inner wall surface of the second cylindrical portion 60 of the control piston 33, the spool cylinder 34
A space formed by the rear end face, the outer peripheral face of the spool valve 35, and the like is a control chamber R4. This control room R4
Is a seal member 59 mounted on the control piston 33.
a separates the pressure chamber R3 from the pressure chamber R3. And
The control chamber R4 communicates with the hydraulic passage 27 via a peripheral groove 76 formed in the fourth hole 21d corresponding to the opening of the hydraulic passage 27.

As shown in FIG. 4, the control valve 33 (the brake pedal 1) is connected to the spool valve 35.
In the initial state (return state) of (0), the first circumferential groove 7 is provided on the outer peripheral surface of the spool cylinder 34 so as to face the circumferential groove 66.
7 are formed. A second circumferential groove 78 is formed on the outer peripheral surface of the spool valve 35 at a predetermined distance axially rearward of the first circumferential groove 77.

This control piston 33 (spool valve 3)
In the initial state 5), the opening of the first communication hole 70 is closed by the spool valve 35,
The communication hole 70 and the control room R4 are substantially shut off. Accordingly, the auxiliary hydraulic pressure source 14 communicating with the first communication hole 70 through the circumferential groove 73 and the hydraulic pressure passage 28 is isolated from the control chamber R4. The opening of the second communication hole 71 is not closed by the spool valve 35, and the hollow portion of the spool cylinder 34 and the control chamber R4 are connected via the second and third communication holes 71 and 72. Communicating. Therefore, the brake fluid reservoir 13 and the control chamber R4 communicate with each other through the fluid pressure passage 24, the circumferential groove 69, the through hole 68, and the second and third communication holes 71 and 72. Thus, the control chamber R4 is filled with the brake fluid at atmospheric pressure.

On the other hand, as shown in FIG. 5, when the control piston 33 (spool valve 35) advances, the first communication hole 70 opens in the first peripheral groove 77 and the peripheral groove 66 And a part of the second circumferential groove 78 overlaps, and the first communication hole 70 and the control chamber R4 are connected to the first communication hole 7.
Communication passage formed between the first circumferential groove 77 and the first circumferential groove 77, the circumferential groove 66
And the first and second peripheral grooves 77 and 78 through a communication passage formed between the first and second peripheral grooves 77 and 78. Accordingly, the auxiliary hydraulic pressure source 14 and the control chamber R4 are connected to the hydraulic pressure path 28, the circumferential groove 73, the first communication hole 7
0, the peripheral groove 66, the first peripheral groove 77 and the like. Then, high-pressure brake fluid from the auxiliary hydraulic pressure source 14 is supplied to the control chamber R4. Also, the second communication hole 71
Is closed by the spool valve 35, so that the control chamber R 4 communicating with the second communication hole 71 and the third communication hole 72 is shut off from the brake fluid reservoir 13.

The plunger 36 is fitted to a front portion of the spool valve 35 to constitute a part of the spool valve 35, and as shown in FIG. 4, a tip portion 36a formed at the front end thereof. Project axially forward of the spool valve 35.

The sleeve 37 is provided on the spool cylinder 3
4, the rear part and the front part have outer diameters slightly smaller than the inner diameter of the cylindrical portion 67 of the spool cylinder 34 and the inner diameter of the fourth hole 21d, respectively, as shown in FIG. Have. The sleeve 37 is fitted in the fourth hole 21d such that the rear portion is accommodated in the cylindrical portion 67. Note that this sleeve 37
The two seal members 81 and 82 are mounted on the outer peripheral surface that contacts the fourth hole 21d at a predetermined interval in the axial direction. Further, the hollow portion of the sleeve 37 is enlarged in diameter at the front, and the rear portion and the front portion are each provided with a rod accommodation portion 83.
And a disk accommodation portion 84. The inner diameter of the rod housing 83 is set to be larger than the inner diameter of the inward flange 67a.

The reaction force rod 38 is accommodated in the rod accommodation portion 83 so as to be slidable in the axial direction, and the rear end thereof is opposed to the distal end portion 36 a of the plunger 36. On the rear side of the reaction force rod 38, a distal end portion 38a protruding from a substantially cylindrical body is formed, and on the outer peripheral side thereof, a substantially annular fitting groove 38b is formed. This fitting groove 3
8b, a coil spring 90 as an urging means, which is locked to the inward flange 67a and interposed between the inward flange 67a and the reaction force rod 38, is fitted. The coil spring 90 urges the reaction rod 38 toward the disk housing 84. At the front side of the reaction rod 38, a contact portion 38c whose diameter is reduced toward the center is formed.

The disk accommodating portion 84 is mounted with a reaction disk 39 made of rubber, for example, and the reaction rod 38 is rotated by the contact portion 38c of the reaction disk 39. Movement in the forward direction is restricted. Further, the reaction force disk 3 of the disk accommodation portion 84
The plug 40 is fitted on the front side of the plug 9. The reaction disk 39 is formed by a spring 85 interposed between the reaction disk 39 and the plug 40.
Thus, it is pressed toward the reaction force rod 38 side.

The space defined by the opposing surface of the fourth hole 21d, the reaction disk 39 and the plug 40 is a reaction chamber R5. The reaction force chamber R5 is formed in a liquid-tight manner by a seal member 86 and a reaction force disk 39 mounted on the outer peripheral surface of the plug 40.

At substantially the middle portions of the seal members 81 and 82 corresponding to the reaction force chamber R5 of the sleeve 37, there are formed through holes 87 and 88 penetrating in the radial direction on the upper and lower sides in FIG. . These through holes 87 and 88 are respectively connected to the hydraulic passages 22 and 27 and the reaction force chamber R through the circumferential groove 30.
5 is communicated. Therefore, the control room R4 and the reaction force room R5
Are the circumferential groove 76, the hydraulic path 27, the circumferential groove 30, and the through hole 88.
The reaction chamber R5 and the power chamber R1 communicate with each other through the through-hole 87, the circumferential groove 30, the hydraulic path 22, the circumferential groove 29, and the clearance C1, and the power chamber R1
And the wheel cylinder 18 have a clearance C1,
It communicates via the circumferential groove 29 and the hydraulic path 25.

As shown in FIG. 6, when the hydraulic pressure in the reaction force chamber R5 is low, the reaction force rod 38 (contact portion 38c) is brought into contact with the reaction force disk 39 in the original state. Since the reaction force rod 38 is urged by the coil spring 90, the spool valve 35 (plunger 36) moves forward without being restricted by the reaction force rod 38. On the other hand, when the liquid pressure in the reaction force chamber R5 becomes larger than a predetermined pressure, the reaction force disk 39 is pressed by the liquid pressure as shown in FIG.
It elastically deforms to swell inside. At this time, the reaction rod 38 in contact with the reaction disk 39 is pushed rearward on the plunger 36 side against the urging force of the coil spring 90. Then, the tip 3 of the reaction force rod 38
The spool valve 35 (the control piston 33) is pressed by the tip 8 a of the plunger 36.
Is pushed back. In the present embodiment, since the reaction force rod 38 is disposed in the rod accommodating portion 83 so as to always contact the reaction force disk 39 by the urging force of the coil spring 90, the reaction force rod 3
The deformation of the reaction force disk 39 due to the relative position of the reaction force disk 39 and the reaction force disk 39 is avoided.
The hydraulic pressure in the reaction chamber R5 at the start of pushing back the pressure is also stabilized. Further, since the contact portion 38c is formed on the reaction force rod 38 that contacts the reaction force disk 39 (bulging portion), the connection when the reaction force rod 38 starts pushing the spool valve 35 back backward. Is buffered.

The auxiliary hydraulic pressure source 14 is for generating a high pressure (power hydraulic pressure) in the brake fluid, and includes an accumulator 91, a hydraulic pump 92, and an electric motor 93. The auxiliary hydraulic pressure source 14 is connected to the electric motor 9.
3 drives the hydraulic pump 92 to suck and pressurize the brake fluid in the brake fluid reservoir 13 and discharge it to the accumulator 91. The accumulator 91 communicates with the hydraulic passage 28, and therefore, the first communication hole 70
When the control room R4 communicates with the control room R4,
Supply high pressure brake fluid to

Next, the operation of the hydraulic brake device will be described. As shown in FIG. 1, the brake pedal 1
In the initial state (return state) in which the second piston 42 is not pressed by the valve body 32, the pressure chamber R3 (the hollow portion of the valve body support portion 52) and the communication passage 54 are not pressed. Is in communication with Therefore, the brake fluid reservoir 13 and the pressure chamber R3 are connected to the hydraulic pressure passage 23 and the fluid supply chamber R.
2, and communicate with each other through a through hole 53 and a communication passage 54 (see FIG. 2). Thus, the pressure chamber R3 is filled with the brake fluid at atmospheric pressure. The inside of the wheel cylinder 17 communicating with the pressure chamber R3 via the hydraulic path 26 is also maintained at substantially the atmospheric pressure.

As shown in FIGS. 1 and 4, in this initial state (returned state), the opening of the first communication hole 70 of the spool cylinder 34 is
5, the first communication hole 70 and the control room R
4 is substantially shut off. Accordingly, the auxiliary hydraulic pressure source 14 communicating with the first communication hole 70 through the circumferential groove 73 and the hydraulic pressure passage 28 is isolated from the control chamber R4. Further, the opening of the second communication hole 71 of the spool cylinder 34 is not closed by the spool valve 35, and the hollow portion of the spool cylinder 34 and the control chamber R4 communicate with the second and third communication holes 71, It communicates via 72. Therefore, the brake fluid reservoir 13 and the control room R4 are connected to the hydraulic pressure passage 24,
Peripheral groove 69, through hole 68, second and third communication holes 71, 72
Is communicated through. Thereby, the control room R4,
The reaction chamber R4 communicates with the peripheral groove 76, the hydraulic path 27, the peripheral groove 30, and the through hole 88 through the reaction force chamber R5. The reaction chamber R5 communicates with the through hole 87, the peripheral groove 30, and the hydraulic path. The brake fluid at approximately atmospheric pressure is also filled in the power chamber R1 that communicates with the power chamber R1 through the circumferential groove 22, the circumferential groove 29, and the clearance C1 (see FIG. 2). The interior of the wheel cylinder 18 communicating with the power chamber R1 (control chamber R4) via the clearance C1, the circumferential groove 29, and the hydraulic path 25 is also maintained at substantially atmospheric pressure.

On the other hand, as shown in FIGS. 2, 3, 5 and 6, when the brake pedal 10 is operated from the initial state (return state) of the brake pedal 10, the push rod 11 is used. The master piston 31 (the first and second pistons 41 and 42, the transmission member 46, and the contact member 47) moves forward, and the second piston 42 is pressed by the valve body 32. At this time, the opening of the communication passage 54 is closed by the elastic body of the valve body 32, and the pressure chamber R
3 (hollow portion of the valve body support portion 52) and the communication passage 54 are shut off. Therefore, the inside of the pressure chamber R3 is provided with the liquid supply chamber R2.
(The brake fluid reservoir 13) and is closed.

Further, as the master piston 31 advances, the control piston 33 advances integrally via a spring 63. And this control piston 33
The spool valve 35 fitted to the body also advances integrally. When the control piston 33 (spool valve 35) moves forward, the opening of the second communication hole 71 is closed by the spool valve 35 (second bank 77). The control chamber R4 communicating through the three communication holes 72 is provided with the brake fluid reservoir 13
Be cut off from. Further, the first communication hole 70 and the control chamber R4 are provided with a communication passage formed between the first communication hole 70 and the first circumferential groove 77, the circumferential groove 66 and the first and second circumferential grooves 77 and 78. And through a communication passage formed between them. Accordingly, the auxiliary hydraulic pressure source 14 and the control chamber R4 communicate with each other via the hydraulic pressure path 28, the peripheral groove 73, the first communication hole 70, the peripheral groove 66, the first peripheral groove 77, and the like. As described above, the high-pressure brake fluid from the auxiliary hydraulic pressure source 14 is supplied to the control chamber R4. Thereby, the reaction chamber R4 communicates with the control chamber R4 through the circumferential groove 76, the hydraulic path 27, the circumferential groove 30, and the through hole 88.
5, the reaction force chamber R5 and the through-hole 87, the circumferential groove 30, the hydraulic path 2
2. The high-pressure brake fluid from the auxiliary hydraulic pressure source 14 is also supplied into the power chamber R1 communicating with the peripheral groove 29 and the clearance C1. And the master piston 3
1 is that the forward movement is assisted by the pressure acting on the boundary surface between the disk part 43 and the cylindrical part 44 of the first piston 41 in the power chamber R1, and the brake fluid in the pressure chamber R3 is compressed, The brake fluid pressure is output to the wheel cylinder 17 via the passage 26. The brake fluid pressure in the power chamber R1 (control chamber R4) is output to the wheel cylinder 18 via the clearance C1, the circumferential groove 29, and the hydraulic pressure path 25.

Here, if the force applied to the control piston 33 based on the hydraulic pressure in the control chamber R4 is greater than the force applied to the control piston 33 based on the hydraulic pressure in the pressure chamber R3,
The control piston 33 moves rearward to move the second communication hole 7.
Reference numeral 1 denotes a control chamber R4 which opens into a hollow portion of the spool cylinder 34 and communicates with the second communication hole 71 and the third communication hole 72.
Is connected to the brake fluid reservoir 13 and communicates with the control room R4.
The inside is decompressed.

On the other hand, if the force applied to the control piston 33 based on the hydraulic pressure in the control chamber R4 is smaller than the force applied to the control piston 33 based on the hydraulic pressure in the pressure chamber R3, the control piston 33 By moving forward, the second communication hole 71
Is closed by the spool valve 35, and the control chamber R4 is replaced with the hydraulic pressure path 28, the circumferential groove 73, and the first communication hole 7.
The pressure in the control chamber R4 is increased by communicating with the auxiliary hydraulic pressure source 14 via the peripheral groove 66, the first peripheral groove 77, and the like.

By repeating the movement of the control piston 33, a force applied to the control piston 33 based on the hydraulic pressure in the control chamber R4 and a force applied to the control piston 33 based on the hydraulic pressure in the pressure chamber R3. Is controlled so as to match. When the pressure in the control chamber R4 (reaction chamber R5) is smaller than the predetermined pressure, a first-stage brake fluid pressure characteristic corresponding to the depression force of the brake pedal 10 is obtained as shown by a solid line in FIG. Can be At this time, a predetermined pressure ratio is maintained between the pressure chamber R3 and the control chamber R4.

When the pressure in the control chamber R4 (reaction chamber R5) exceeds a predetermined pressure, the reaction disk 39 is pressed by the liquid pressure as shown in FIG. It elastically deforms to swell inside. At this time, the reaction force rod 38, which is in contact with the reaction force disk 39, is pushed rearward on the plunger 36 side against the urging force of the coil spring 90. The tip 38a of the reaction force rod 38 is connected to the tip 36 of the plunger 36.
By being pressed by a, the spool valve 35 is pushed back. By applying such a reaction force,
Changing the balance of the forces acting on the control piston 33,
The pressure increase gradient of the brake fluid in the control room R4 is reduced. Then, a second-stage brake fluid pressure characteristic is obtained in which the pressure increase gradient with respect to the depression force of the brake pedal 10 is gentler than the first-stage brake fluid pressure characteristic. At this time, a predetermined pressure ratio is maintained between the pressure chamber R3 and the control chamber R4.

Here, since the reaction force rod 38 is arranged in the rod accommodating portion 83 so as to always contact the reaction force disk 39 by the urging force of the coil spring 90, the reaction force rod 38 and the reaction force disk The change in the deformation of the reaction force disc 39 due to the relative position of the reaction force 39 is avoided, and the reaction force chamber R5 when the spool valve 35 starts to be pushed back backward via the reaction force rod 38.
As described above, the internal fluid pressure is also stabilized.
Accordingly, the state in which the assisting force of the depression force of the brake pedal 10 starts to be reduced, that is, the state in which the first-stage brake fluid pressure characteristic corresponding to the depression force of the brake pedal 10 shifts to the second-stage brake fluid pressure characteristic is stabilized. Have been.

Further, since the contact portion 38c is formed on the reaction force rod 38 which contacts the reaction force disk 39 (bulging portion), the reaction force rod 38 is connected to the spool valve 35.
, The transition from the first-stage brake fluid pressure characteristic to the second-stage brake fluid pressure characteristic in accordance with the depression force of the brake pedal 10 is smoothly rounded.

The first and second brake fluid pressure characteristics according to the depression force of the brake pedal 10 make the pedal operation feeling suitable. As described in detail above, according to the present embodiment, the following effects can be obtained.

(1) In the present embodiment, the reaction force rod 38 always receives the reaction force disc 39 by the urging force of the coil spring 90.
Is arranged in the rod accommodating portion 83 so as to abut the same, so that the deformation of the reaction force disk 39 is prevented from changing due to the relative position of the reaction force rod 38 and the reaction force disk 39. Can be. For this reason, the hydraulic pressure in the reaction force chamber R5 when the spool valve 35 starts to be pushed back through the reaction force rod 38 can also be stabilized. Therefore, the state in which the assisting force of the depression force of the brake pedal 10 starts to be reduced, that is, the state in which the brake fluid pressure characteristic of the first stage corresponding to the depression force of the brake pedal 10 shifts to the brake fluid pressure characteristic of the second stage is stabilized. Can be
The pedal operation feeling can be made favorable.

(2) In the present embodiment, the fitting groove 38b is formed in the reaction force rod 38, and the coil spring 90 is fitted in the fitting groove 38b. Therefore, the coil spring 90 can be stably coupled to the reaction force rod 38, and its operation can be stabilized.

(3) In this embodiment, the inward flange 6
7a was formed integrally with the spool cylinder 34. Therefore,
An increase in the number of parts can be suppressed to a minimum. (4) In the present embodiment, the biasing means can be a coil spring 90 having an extremely simple shape.

The embodiment of the present invention is not limited to the above embodiment, but may be modified as follows. In the above-described embodiment, the control chamber R4 and the reaction force chamber R5 are communicated with each other to have the same hydraulic pressure.
May be independently controlled.

In the above embodiment, the coil spring 90 is employed as the urging means, but other urging means such as a leaf spring or an elastic body may be employed. In the above embodiment, the inward flange 67a as an immovable portion is formed integrally with the spool cylinder 34.
For example, a similar flange or the like may be provided on the cylinder body 21 or the like.

In the above embodiment, the reaction force rod 3
Although the coil spring 90 is fitted into the fitting groove 38b of FIG. 8 and the coil spring 90 is connected to the reaction force rod 38, the reaction force rod 38 and the coil spring 90 may be connected to each other by providing locking means or the like. Good. Further, it is not always necessary to make such a connection, and the reaction force rod 38 and the inward flange 67a are not required.
May be interposed only between them.

In the above embodiment, the reaction force rod 3
8 is disposed in the rod accommodating portion 83 so as to always contact the reaction force disk 39 by the urging force of the coil spring 90. In short, the reaction force disk 39 and the reaction force rod 38 are in the original state of the reaction force disk 39. It suffices if the relative position along the sliding direction is maintained.

Next, technical ideas other than the claims which can be grasped from the above embodiments will be described below together with their effects. (A) The hydraulic brake device for a vehicle according to any one of claims 2 to 4, wherein the urging means is a coil spring.

According to this structure, the biasing means is a coil spring having an extremely simple shape.

[0069]

As described in detail above, according to the first and second aspects of the present invention, a favorable pedal operation feeling can be transmitted to the driver.

According to the third aspect of the present invention, the urging means can be stably connected to the reaction force rod, and the operation thereof can be stabilized. According to the fourth aspect, an increase in the number of parts can be suppressed to a minimum.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a hydraulic brake device according to the present invention.

FIG. 2 is an exemplary sectional view showing an operation mode of the embodiment;

FIG. 3 is an exemplary sectional view showing an operation mode of the embodiment;

FIG. 4 is a sectional view showing the same embodiment.

FIG. 5 is an exemplary sectional view showing an operation mode of the embodiment;

FIG. 6 is an exemplary sectional view showing an operation mode of the embodiment;

FIG. 7 is an exemplary sectional view showing an operation mode of the embodiment;

FIG. 8 is a graph showing the relationship between the brake pedal pressure and the brake fluid pressure.

[Explanation of symbols]

 R1 Power chamber R3 Pressure chamber R4 Control chamber R5 Reaction chamber 10 Brake pedal 21 Cylinder body 31 Master piston 33 Control piston 34 Spool cylinder as cylinder 35 Spool valve 38 Reaction rod 38b Fitting groove as fitting means 39 Reaction force Disc 90 Coil spring as biasing means

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Motohiko Yabutani 2-1-1 Asahi-cho, Kariya-shi, Aichi, Japan F-term (reference) 3D048 BB25 CC10 CC19 GG13 GG16 GG22 QQ07

Claims (4)

[Claims] 1. A master piston drivingly connected to a brake pedal, a control piston interlocked with the master piston, a spool valve switching a brake fluid flow path interlocked with the control piston, and a spool valve elastically deformed according to the hydraulic pressure. A power disk, a pressure chamber, a control chamber, and a reaction chamber are separately formed by housing a force disk and a reaction rod that slides toward the spool valve based on elastic deformation of the reaction disk in a cylinder body. The flow path of the brake fluid is switched so that the brake fluid in the control chamber is boosted by the interlocking of the spool valve with one side movement of the control piston, and the hydraulic pressure in the power chamber introduced from the control chamber is changed. An assisting force is applied to the depressing force of the brake pedal, and the brake fluid in the pressure chamber is compressed according to the assisting force to output a brake fluid pressure. When the hydraulic pressure in the force chamber is greater than a predetermined pressure, the reaction force transmitting means is pressed by the elastic deformation of the reaction force disk due to the liquid pressure in the reaction chamber, and the reaction force transmitting means is slid. By applying a reaction force that pushes the spool valve back to the other side via the force transmission means, the balance of the force acting on the control piston is changed, and the pressure increase gradient of the brake fluid in the control chamber is reduced, and the control A hydraulic brake device for a vehicle for reducing the assisting force of the depression force of the brake pedal due to the hydraulic pressure in the power chamber introduced from the power chamber, wherein the reaction disk and the reaction force when the reaction disk is in an original state A hydraulic brake device for a vehicle, comprising: holding means for holding a relative position along a sliding direction with a rod. 2. The hydraulic brake device for a vehicle according to claim 1, wherein the holding means is a fixed part disposed opposite to the reaction force rod on a side opposite to the reaction force disk with respect to the reaction force rod. And urging means interposed between the reaction force rod and the immovable portion, wherein the reaction force rod is urged by the urging means so as to contact the reaction force disk. Characteristic vehicle hydraulic brake device. 3. The hydraulic brake for a vehicle according to claim 2, wherein said reaction force rod includes a fitting means for fitting with said urging means. apparatus. 4. The vehicle hydraulic brake device according to claim 2, wherein the stationary part is formed integrally with a cylinder that slidably supports the spool valve. Hydraulic brake device.