JP2001158339A - Hydraulic brake device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic brake device for a vehicle capable of providing a suitable pedal operating feel while preventing over-braking and under-braking. SOLUTION: The pressure of brake fluid in a control chamber R4 is built up by the operation (advance) of a brake pedal 10, and hydraulic pressure within a power chamber R1 adds an assisting force to a brake pedal operating force so as to compress brake fluid in a pressure chamber R3 and output the brake hydraulic pressure. When the hydraulic pressure of brake fluid in a reaction chamber R5 is greater than a predetermined pressure, a reaction disc 39 is elastically deformed by the hydraulic pressure within the reaction chamber R5 to cause sliding movement of a reaction transmitting means 38 and vary the balance of forces acting on a control piston 33 so as to reduce the gradient of pressure buildup of the brake fluid in the control chamber R4 and also to reduce the assisting force produced by the hydraulic pressure within the power chamber R1. When the hydraulic pressure within the reaction chamber R5 is greater than an actuation starting pressure set to be greater than the predetermined pressure, the pressure-receiving area of the reaction transmitting means 38 during its sliding movement is set to be larger than it is when the hydraulic pressure within the pressure chamber R5 is smaller than the actuation starting pressure.

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. H11-115728 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 transmission means 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 the solid line in FIG. 11, a first-stage brake fluid pressure characteristic corresponding to the depression force of the brake pedal is obtained.

On the other hand, when the liquid pressure in the reaction chamber is higher than a predetermined pressure, the reaction disk is elastically deformed by the liquid pressure in the reaction chamber, and the reaction force transmitting means is slid to move through the reaction disk. Push the spool valve back. 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 chamber introduced from the control room is reduced, and as shown by the solid line in FIG. 11, the brake hydraulic pressure corresponding to the depression force of the brake pedal is reduced. A second stage brake fluid pressure characteristic in which the pressure increase gradient is suppressed is obtained.

[0005]

By the way, in order to obtain a favorable pedal operation feeling, the characteristics of the brake fluid pressure according to the depression force of the brake pedal must be adjusted along the curve shown by the two-dot chain line in FIG. Is generally known to be ideal. In the case where the ideal characteristics are deviated from the above, the brakes become too effective or inadequately effective. Therefore, in the hydraulic brake device, it is necessary to operate the brakes within a very narrow range of the depression force of the brake pedal. Yes, pedal operation feeling is not good.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hydraulic brake device for a vehicle which can obtain a favorable pedal operation feeling without excessively applying or insufficiently applying the brake.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 has a brake fluid pressure characteristic of three or more steps with respect to the depression force of a brake pedal, and a brake based on an increase in the depression force. The gist is that the pressure increase gradient of the hydraulic pressure is gradually reduced.

According to a second aspect of the present invention, there is provided a master piston drivingly connected to a brake pedal, a control piston interlocked with the master piston, a spool valve for switching a brake fluid flow path interlocked with the control piston, and a hydraulic pressure. A reaction force disk elastically deformed in response to the above, and a reaction force transmission means sliding toward the spool valve side based on the elastic deformation of the reaction force disk are housed in a cylinder body, and a power chamber, a pressure chamber, a control chamber, and The reaction force chambers are formed separately, and the flow path of the brake fluid is switched so as to increase the pressure of the brake fluid in the control room by interlocking the spool valve with one side movement of the control piston, and is introduced from the control chamber. The assisting force is applied to the depressing force of the brake pedal by the fluid pressure in the power chamber, and the brake fluid in the pressure chamber is compressed according to the assisting force to form a brake. A hydraulic pressure is output. On the other hand, when the hydraulic pressure in the reaction chamber is larger than a predetermined pressure, the reaction force transmitting means is pressed by the elastic deformation of the reaction disk due to the hydraulic pressure in the reaction chamber, and the reaction force is transmitted. The balance of the force acting on the control piston is changed by sliding the force transmitting means and applying a reaction force for pushing the spool valve to the other side via the reaction force transmitting means, thereby changing the brake fluid in the control chamber. In the hydraulic brake system for a vehicle, which reduces the boost gradient of the brake chamber and reduces the assisting force of the depression force of the brake pedal by the hydraulic pressure in the power chamber introduced from the control chamber, the hydraulic pressure in the reaction chamber is reduced. The pressure receiving area when the reaction force transmitting means slides due to the elastic deformation of the reaction force disk when the pressure is larger than the operation start pressure set larger than the predetermined pressure is determined by the hydraulic pressure in the reaction force chamber when the operation starts. When less than pressure It is summarized as being set larger than the pressure receiving area during sliding of reaction force transmission means due to the elastic deformation of the reaction force disc.

According to a third aspect of the present invention, in the vehicle hydraulic brake device according to the second aspect, the reaction force transmitting means includes a reaction force rod and a reaction force supporting the reaction force rod slidably. A force cylinder, and biasing means interposed between the reaction force cylinder and the immovable portion for biasing the reaction force cylinder so as to contact the reaction force disk. When the pressure is smaller than the operation start pressure, only the reaction force rod is pressed by the elastic deformation of the reaction force disk due to the liquid pressure in the reaction force chamber to slide the reaction force rod, and the reaction force rod is moved through the reaction force rod. When the spool valve is pushed back to the other side and the hydraulic pressure in the reaction chamber is larger than the operation start pressure, the urging force of the urging means is resisted by the elastic deformation of the reaction disk due to the hydraulic pressure in the reaction chamber. The reaction force cylinder to the reaction force rod Moni pressed to slide the reaction force rod and the reaction force cylinder, and summarized in that push back the spool valve through which the reaction force rod and the reaction force cylinder on the other side.

(Operation) According to the structure of the first aspect of the present invention, the brake fluid pressure characteristic in three or more stages with respect to the pedaling force of the brake pedal causes the pressure increasing gradient of the brake fluid pressure based on the increase of the pedaling force to be stepwise. By making the brake pressure gentler, the ideal brake fluid pressure characteristic according to the pedaling force can be approached, and a suitable pedal operation feeling can be obtained without causing excessive or insufficient braking.

According to the second aspect of the present invention, when the reaction force transmitting means slides due to the elastic deformation of the reaction force disk when the hydraulic pressure in the reaction force chamber is higher than the operation start pressure. The pressure receiving area is set larger than the pressure receiving area when the reaction force transmitting means slides due to the elastic deformation of the reaction force disk when the liquid pressure in the reaction force chamber is smaller than the operation start pressure.
Therefore, the load applied to the reaction force transmitting means by the elastic deformation of the reaction force disk based on the liquid pressure in the reaction force chamber,
That is, the force that pushes the spool valve back to the other side via the reaction force transmitting means is higher when the hydraulic pressure in the reaction force chamber is larger than the operation start pressure than when the hydraulic pressure is smaller than the operation start pressure. The increase gradient with respect to the increase of the value increases. When the spool valve is pushed back by such a force, the balance of the force acting on the control piston is changed, and the pressure increase gradient of the brake fluid in the control room is reduced,
Since the assisting force of the brake pedal depressing force due to the fluid pressure in the power room introduced from the control room is reduced, the pressure increase gradient of the brake fluid pressure based on the increase in the brake pedal depressing force is The pressure is relaxed when the pressure is higher than the operation start pressure than when the pressure is low.

As described above, the brake hydraulic pressure characteristic with respect to the depression force of the brake pedal is such that when the hydraulic pressure in the reaction chamber becomes larger than a predetermined pressure, and when the hydraulic pressure in the reaction force chamber increases from the predetermined pressure to the above-mentioned operation start pressure, the same operation start pressure is obtained. When it becomes larger, the pressure increase gradient is gradually relaxed to approximate the ideal brake fluid pressure characteristics according to the pedaling force, and suitable pedal operation without excessive braking or insufficient braking Feeling is obtained.

According to the third aspect of the present invention, when the hydraulic pressure in the reaction chamber is smaller than the operation start pressure,
Due to the elastic deformation of the reaction force disc due to the liquid pressure in the reaction force chamber, only the reaction force rod is pressed to slide the reaction force rod, and the spool valve is pushed back to the other side via the reaction force rod, When the hydraulic pressure in the force chamber is larger than the operation start pressure, the reaction cylinder is pressed together with the reaction rod by the elastic deformation of the reaction disk by the liquid pressure in the reaction chamber, and the reaction rod and the reaction force are pressed. The cylinder is slid, and the spool valve is pushed back to the other side through the reaction force rod and the reaction force cylinder. Accordingly, when the hydraulic pressure in the reaction chamber is higher than the operation start pressure, the increasing gradient of the force for pushing the spool valve back to the other side with respect to the increase in the pressure in the reaction chamber becomes larger than when the hydraulic pressure in the reaction chamber is low.

As described above, by the reaction force transmitting means having a very simple structure including the reaction force rod, the reaction force cylinder and the urging means, it is possible to obtain a favorable pedal operation feeling without excessive or insufficient braking effect. can get.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a hydraulic brake device 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 force transmitting means 38, a reaction force disk 39, and a plug 40 are provided as immovable parts.

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, 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 68
Communicates with the circumferential groove 69 formed in the fourth hole 21d corresponding to the opening of the hydraulic passage 24. Therefore, the hollow portion of the cylindrical portion 67 is provided with the through hole 68, the circumferential groove 69, and Hydraulic passage 2
4 communicates with the brake fluid reservoir 13.

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 rear part of the spool valve 35 is mounted in a liquid-tight manner with respect to the first cylindrical part 59,
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 part of the spool valve 35 is slidably supported on the spool cylinder 34.

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. The hollow portion of the sleeve 37 is enlarged in diameter at the front, and the rear portion and the front portion are a reaction force transmitting means accommodating portion 83 and a disk accommodating portion 84, respectively. The inner diameter of the reaction force transmitting means accommodating portion 83 is set to be larger than the inner diameter of the spool cylinder 34.

The reaction force transmitting means 38 is accommodated in the reaction force transmitting means accommodating portion 83 so as to be slidable in the axial direction.
More specifically, the reaction force transmitting means accommodating portion 83 includes a reaction force cylinder 96, a reaction force rod 97, and a coil spring 98 as urging means.

The reaction force cylinder 96 has an outer diameter slightly smaller than the reaction force transmission means accommodating portion 83,
5 and the reaction force transmitting means accommodating portion 83
It is formed in a substantially cylindrical shape having a length in the axial direction equivalent to that of, and a housing groove 96a cut out along the outer peripheral surface is formed on the rear side. The reaction cylinder 96
The hollow portion is a rod housing portion 96b.

The reaction force rod 97 has an outer diameter slightly smaller than the inner diameter of the reaction force cylinder 96, and is slidably supported by the rod accommodating portion 96b. It is arranged facing the distal end portion 36a. A contact portion 97a whose diameter is reduced toward the center is formed on the front side of the reaction force rod 97.

The coil spring 98 is accommodated in the accommodating groove 96a of the reaction force cylinder 96 and is interposed between the reaction force cylinder 96 and the end surface of the spool cylinder 34. It is urged toward the disk storage portion 84.

The disk accommodating portion 84 has a rubber reaction disk 39 mounted thereon, for example. The reaction force transmission means 38 is restricted from moving forward in the axial direction by the reaction disk 39. . Further, the plug 40 is fitted to the front side of the disk accommodating portion 84 with respect to the reaction disk 39. Then, the reaction force disk 39
Is pressed toward the reaction force transmitting means 38 by a spring 85 interposed between the reaction force disk 39 and the plug 40.

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 radially 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 smaller than a predetermined pressure, the spool valve 35 (plunger 36) operates the reaction force transmitting means 3
Advance without being regulated by 8.

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. At this time,
Only the reaction rod 97 is pushed rearward on the spool valve 35 (plunger 36) side. The tip of the reaction rod 97 is connected to the tip 36 of the plunger 36.
By being pressed by a, the spool valve 35 (control piston 33) is pushed back. Such an operation is adjusted by the set load and the spring constant of the coil spring 98 that urges the reaction force cylinder 96 so as to contact the reaction force disk 39.

Further, when the hydraulic pressure in the reaction force chamber R5 becomes higher than the operation start pressure which is higher than the predetermined pressure, FIG.
As shown in the figure, the reaction force disc 39 is pressed by the hydraulic pressure, and the reaction force transmitting means accommodating portion 8 in which the reaction force cylinder 96 is disposed against the urging force of the coil spring 98.
3 elastically deforms to swell. At this time, the pressure receiving area at the time of sliding as the reaction force transmission means 38 increases, and the reaction force cylinder 96 is pushed out together with the reaction force rod 97 rearward on the spool valve 35 side. When the tip end of the reaction cylinder 96 is pressed against the front end face of the spool valve 35, the spool valve 35 (control piston 33) is pushed back with a stronger force.

The auxiliary hydraulic pressure source 14 is for generating 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 (return 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 (returned 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 integrally advances 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 becomes 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 a 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 hydraulic pressure in the control chamber R4 (reaction chamber R5) exceeds a predetermined pressure, the reaction disk 39 is pressed by the hydraulic pressure as shown in FIG. It is elastically deformed so as to swell into 96b. At this time, only the reaction rod 97 is connected to the spool valve 35.
(Plunger 36) is pushed backward. When the tip of the reaction rod 97 is pressed by the tip 36a of the plunger 36, the spool valve 3
5 is pushed back. By applying such a reaction force, the balance of the force acting on the control piston 33 is changed, and the pressure increase gradient of the brake fluid in the control chamber R4 is reduced. Then, as also shown by the solid line in FIG. 11, 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. Incidentally, since the contact portion 97a is formed on the reaction force rod 97 that contacts the reaction force disc 39 (the bulging portion), the connection when the reaction force rod 97 starts to push the spool valve 35 back backward. That is, the transition from the first-stage brake fluid pressure characteristic to the second-stage brake fluid pressure characteristic according to the depression force of the brake pedal 10 is smoothly rounded.

Further, when the hydraulic pressure in the control chamber R4 (reaction chamber R5) becomes larger than the operation start pressure, the reaction disk 39 is pressed by the hydraulic pressure as shown in FIG. It is elastically deformed so as to protrude into the reaction force transmitting means accommodating portion 83 in which the reaction force cylinder 96 is disposed, against the urging force of the coil spring 98. At this time, the pressure receiving area at the time of sliding as the reaction force transmitting means 38 increases, and the reaction force cylinder 96 and the reaction force rod 97 move together with the spool valve 3.
It is pushed backward, which is the fifth side. When the tip end of the reaction cylinder 96 is pressed against the front end face of the spool valve 35, the spool valve 35 (control piston 33) is pushed back with a stronger force. In other words, when the hydraulic pressure in the reaction force chamber R5 is higher than the operation start pressure, the spool valve 35 for the increase in the pressure in the reaction force chamber R5 is higher than when the hydraulic pressure is lower than the operation start pressure.
Of the force for pushing back to the other side increases. And
When the spool valve 35 is pushed back by such a force, the balance of the force acting on the control piston 33 is changed, the pressure gradient of the brake fluid in the control room R4 is reduced, and the power introduced from the control room R4 is reduced. Since the assisting force of the depression force of the brake pedal 10 due to the hydraulic pressure in the chamber R1 is reduced, the pressure increase gradient of the brake hydraulic pressure based on the increase in the depression force of the brake pedal 10 is such that the hydraulic pressure in the reaction force chamber R5 is When the pressure is higher than the operation start pressure, the pressure is more relaxed than when the pressure is lower. As a result, as shown by the thick solid line in FIG. 11, a third-stage brake fluid pressure characteristic is obtained in which the pressure increase gradient with respect to the pedaling force of the brake pedal 10 is more gentle than the second-stage brake fluid pressure characteristic. . At this time, a predetermined pressure ratio is maintained between the pressure chamber R3 and the control chamber R4.

As described above, the brake hydraulic pressure characteristic with respect to the depression force of the brake pedal is determined to be the same when the hydraulic pressure in the reaction force chamber R5 is higher than a predetermined pressure and when the pressure is within the range from the predetermined pressure to the operation start pressure. When the pressure becomes larger than the starting pressure, the pressure increase gradient is gradually reduced, and the ideal brake fluid pressure characteristic according to the pedaling force is approached. Pedal operation feeling is obtained.

Next, a quantitative analysis of the operation of the hydraulic brake device will be briefly described with reference to the schematic diagram of FIG. Note that the same members as those in the above embodiment shown in this schematic diagram will be described with the same reference numerals. For the sake of simplicity, the effects of the sliding resistance of the various seal members and the set loads of the springs 63 and 75 are omitted. In FIG. 9, the brake pedal 10
The input load corresponding to the stepping force of F is F, the hydraulic pressure of the power chamber R1, the control chamber R4 and the reaction chamber R5 is Pp, the hydraulic pressure of the pressure chamber R3 is Pm, and the large-diameter cross-sectional area (rear side) of the master piston 31 is S
1. Assuming that the small-diameter sectional area (front side) is S2, the sectional area (rear side) of the control piston 33 is S3, the sectional area (rear side) of the spool valve 35 is S4, and the pressure receiving area of the reaction force transmitting means 38 is S5. , F = Pm · S3 · (1 + ((S2-S1) / (S3-S)
4 + S5))). Accordingly, although the input load F increases in accordance with the increase in the hydraulic pressure Pm of the pressure chamber R3, the increasing gradient of the input load F decreases as the pressure receiving area S5 of the reaction force transmitting means 38 increases. Therefore, as shown in FIG. 10, when the hydraulic pressure Pp of the reaction force chamber R5 becomes larger than a predetermined pressure, when the pressure from the predetermined pressure to the operation start pressure,
When the pressure becomes larger than the operation start pressure, the pressure receiving area S
5 changes stepwise, as shown in FIG. 11, the pressure increase gradient of the brake fluid pressure characteristic with respect to the pedaling force of the brake pedal is gradually reduced, and an ideal brake fluid pressure characteristic corresponding to the pedaling force is obtained. Get closer.

As described in detail above, according to the present embodiment, the following effects can be obtained. (1) In the present embodiment, when the hydraulic pressure in the control chamber R4 (reaction force chamber R5) is from the predetermined pressure to the operation start pressure, the reaction force disc 39 is swelled into the rod housing 96b. By elastically deforming, only the reaction force rod 97 is pushed rearward on the spool valve 35 (plunger 36) side to push back the spool valve 35 back.
When the hydraulic pressure in the control chamber R4 (the reaction force chamber R5) is higher than the operation start pressure, the reaction force disk 96 is disposed against the urging force of the coil spring 98 to dispose the reaction force disk 39. The reaction force cylinder 96 is elastically deformed so as to protrude into the reaction force transmitting means accommodating portion 83, and the reaction force cylinder 96
7, the spool valve 35 (the control piston 33) is pushed rearward with a stronger force to be pushed rearward. Therefore, when the spool valve 35 is pushed back by such a force, the balance of the force acting on the control piston 33 is changed, and the pressure increase gradient of the brake fluid in the control chamber R4 is reduced, and the pressure is introduced from the control chamber R4. Since the assisting force of the depressing force of the brake pedal 10 due to the fluid pressure in the power chamber R1 is reduced, the depressing force of the brake pedal 10 increases when the fluid pressure in the reaction force chamber R5 is higher than the operation start pressure. , The pressure increase gradient of the brake fluid pressure can be made smaller than when it is small. Then, it is possible to obtain a third-stage brake fluid pressure characteristic in which the pressure increasing gradient with respect to the depression force of the brake pedal 10 is more gentle than the second-stage brake fluid pressure characteristic. Thus, when the hydraulic pressure in the reaction force chamber R5 becomes larger than a predetermined pressure, when the hydraulic pressure in the reaction force chamber R5 becomes larger than the predetermined pressure, the brake hydraulic pressure characteristic is changed to the same operation start pressure. When it becomes larger, the pressure increase gradient is gradually reduced to approximate the ideal brake fluid pressure characteristic according to the pedaling force. You can get a ring.

(2) In this embodiment, the brake pedal 1
The third-stage brake fluid pressure characteristic according to the pedaling force of 0 can be realized by an extremely simple configuration including the reaction force cylinder 96, the reaction force rod 97, and the coil spring 98.

(3) In the present embodiment, the coil spring 98 is interposed between the spool cylinder 34 and the reaction cylinder 96 by using the front end face. Therefore, for example, an increase in the number of components can be suppressed to a minimum as compared with a case where a similar immovable portion is separately provided.

(4) In this embodiment, the biasing means can be a coil spring 98 having an extremely simple shape. (5) In the present embodiment, the reaction force cylinders 96 are arranged in the reaction force transmission means accommodating portion 83 so as to always contact the reaction force disk 39 by the urging force of the coil spring 98. Further, it is possible to prevent the deformation mode of the reaction force disk 39 from being changed due to the relative position of the reaction force disk 39. 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 cylinder 96 can also be stabilized. Therefore, the state in which the assisting force of the depression force of the brake pedal 10 starts to be further reduced, that is, the state in which the second-stage brake hydraulic pressure characteristic corresponding to the depression force of the brake pedal 10 shifts to the third-stage brake hydraulic pressure characteristic is stabilized. Can be

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 98 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 front end surface of the spool cylinder 34 is used as the immovable portion. However, the front end surface may be separately provided on the cylinder body 21 or the like, for example.

In the above embodiment, in order to change the pressure receiving area during sliding as the reaction force transmitting means 38, the reaction force transmitting means 38 is connected to the reaction force cylinder 96, the reaction force rod 97 and the coil spring 98. Although the configuration has been described, such a configuration is an example. The point is that the pressure receiving area at the time of sliding as the reaction force transmitting means 38 is changed according to the liquid pressure in the control chamber R4 (reaction force chamber R5).

The structure is arbitrary as long as the pressure increase gradient of the brake fluid pressure based on the increase in the pedaling force is gradually reduced by three or more stages of the brake fluid pressure characteristics with respect to the pedaling force of the brake pedal 10. .

Next, technical ideas other than the claims that 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 claim 3, wherein the immovable portion is a cylinder that slidably supports the spool valve.

According to this structure, the immovable portion is a cylinder that slidably supports the spool valve. Therefore,
The increase in the number of parts is minimized. (B) The hydraulic brake device for a vehicle according to claim 3 or (a), wherein the urging means is a coil spring.

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

[0076]

As described in detail above, according to the first to third aspects of the present invention, it is possible to obtain a favorable pedal operation feeling without excessive or insufficient braking.

[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 an exemplary sectional view showing an operation mode of the embodiment;

FIG. 9 is a sectional view schematically showing the same embodiment.

FIG. 10 is a graph showing the relationship between brake fluid pressure and area.

FIG. 11 is a graph showing a relationship between a brake pedal pressure and a 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 immovable part 35 Spool valve 38 Reaction force transmission means 39 Reaction disk 96 Reaction cylinder 97 Reaction Force rod 98 Coil spring as biasing means

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahito Hattori 2-1-1 Asamachi, Kariya City, Aichi Prefecture Aisin Seiki Co., Ltd. F-term (reference) 3D048 BB25 BB37 CC10 CC19 GG03 GG13 GG16 GG22 GG23 GG27 HH15 HH16

Claims (3)

[Claims] 1. A hydraulic pressure for a vehicle, comprising: three or more brake fluid pressure characteristics with respect to a pedaling force of a brake pedal, wherein a pressure increasing gradient of the brake fluid pressure based on the increase in the pedaling force is gradually reduced. Brake device. 2. A master piston which is drivingly connected to a brake pedal, a control piston which is interlocked with the master piston, a spool valve which switches a flow path of brake fluid in conjunction with the control piston, and a spool valve which elastically deforms according to the hydraulic pressure. A power disk, a pressure chamber, a control chamber, and a reaction chamber are respectively formed by housing a force disk and a reaction force transmission means that slides toward the spool valve based on elastic deformation of the reaction disk in the 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 increased. By applying an assisting force to the depression force of the brake pedal, the brake fluid in the pressure chamber is compressed according to the assisting force to output a brake fluid pressure. When the liquid pressure in the reaction force chamber is larger than a predetermined pressure, the reaction force transmission means is pressed by the elastic deformation of the reaction force disk due to the liquid pressure in the reaction force chamber, and the reaction force transmission means is slid. By applying a reaction force that pushes the spool valve back to the other side via the reaction 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 In a hydraulic brake device for a vehicle, which reduces an assisting force of a depression force of the brake pedal by a hydraulic pressure in the power chamber introduced from a control room, a hydraulic pressure in the reaction chamber is set to be higher than the predetermined pressure. The pressure receiving area at the time of sliding of the reaction force transmitting means due to the elastic deformation of the reaction force disk when it is larger than the operation start pressure,
A vehicle, wherein the pressure receiving area when the reaction force transmitting means slides due to elastic deformation of the reaction force disk when the hydraulic pressure in the reaction force chamber is smaller than the operation start pressure is set to be larger. Hydraulic brake equipment. 3. The hydraulic brake device for a vehicle according to claim 2, wherein the reaction force transmission means includes a reaction force rod, a reaction force cylinder that slidably supports the reaction force rod, and the reaction force. Biasing means interposed between the cylinder and the immovable portion to bias the reaction force cylinder so as to abut on the reaction force disk, when the hydraulic pressure in the reaction force chamber is smaller than the operation start pressure. The reaction force disk is elastically deformed by the liquid pressure in the reaction force chamber, and only the reaction force rod is pressed to slide the reaction force rod, and the spool valve is pushed back to the other side via the reaction force rod. When the hydraulic pressure in the reaction chamber is greater than the operation start pressure, the reaction cylinder is resiliently deformed by the hydraulic pressure in the reaction chamber to cause the reaction cylinder to resist the urging force of the urging means. Press the reaction force rod together to A hydraulic brake device for a vehicle, characterized in that the hydraulic valve and the reaction force cylinder slide, and the spool valve is pushed back to the other side via the reaction force rod and the reaction force cylinder.