JPH10250568A - Brake stroke simulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of a large abutting sound when a high speed brake operation is carried out, as to a brake stroke simulator which regulates the brake operation feeling of the brake device of a vehicle. SOLUTION: A piston 32 is inserted to the inside of a housing 122, so as to partition a hydraulic pressure room 34 and a back side room 36. The hydraulic pressure room 34 communicates with a master cylinder. The back side room 36 communicates with a reservoir tank. A spring 138 is provided between the piston 32 and a plug 124. A fitting projection 123 is provided on the piston 32. A fitting recess 134 fitted with the fitting projection 123 is provided at the end face of the plug 124. A through passage 128 and a through hole 132 are provided thereby making a fitting recess 134 to communicate with the back side room 36 passing through the plug 124. A check valve to allow only the flowing of a liquid from the penetration passage 128 side to the fitting recess 134 is provided inside the fitting recess 134.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake stroke simulator, and more particularly to a brake stroke simulator suitable as a device for adjusting a feeling of a brake operation in a vehicle brake device.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open No. 6-2111
As disclosed in No. 24, a brake device using a brake stroke simulator (hereinafter, referred to as a stroke simulator) is known. The conventional brake device includes a master cylinder that generates a hydraulic pressure corresponding to a brake pedal force, a hydraulic pressure source that generates a predetermined hydraulic pressure regardless of the brake pedal force, and a hydraulic pressure generated from the hydraulic pressure source as a brake pedal force. And a hydraulic pressure control valve that controls the hydraulic pressure in accordance with the hydraulic pressure.

[0003] The above-mentioned conventional brake device has a first state in which brake fluid flowing out of a high-pressure source flows into a wheel cylinder and a second state in which brake fluid flowing out of a master cylinder flows into a wheel cylinder. A control valve for switching is provided. According to the above-described conventional brake device, the function of electronically controlling the wheel cylinder pressure P _{W / C} can be realized by realizing the first state. Further, by realizing the second state, a function of manually operating the wheel cylinder pressure P _{W / C} can be realized.

In the above conventional brake device, when the hydraulic pressure control valve realizes the first state, the master cylinder is separated from the wheel cylinder. The brake pedal is
When a brake pedal force is applied, the brake fluid flows out of the master cylinder to make a stroke. Therefore, if the brake fluid does not flow out of the master cylinder when the first state is realized, a state occurs in which the brake pedal does not stroke even though the brake pedal force is applied.

[0005] The above-described conventional brake device is provided with a stroke simulator in order to prevent such a situation from occurring. In the stroke simulator, the hydraulic control valve is the first
In order to realize the above condition, a hydraulic chamber is provided which communicates with the master cylinder. The hydraulic chamber is separated by a piston. The piston is urged toward the hydraulic chamber by a spring.

[0006] According to the above configuration, an amount of brake fluid corresponding to the master cylinder pressure PM _{/ C} can flow into the hydraulic chamber of the stroke simulator. For this reason, according to the conventional brake device, an appropriate brake operation feeling can be realized even when the hydraulic pressure control valve realizes the first state.

[0007]

However, according to the conventional stroke simulator, when the brake pedal is operated at a high speed, that is, when the master cylinder pressure PM _{/ C} is rapidly increased, the piston is not operated. High displacement rates occur. Then, the displacement speed is maintained at a high speed until the piston reaches the displacement end. For this reason, according to the conventional stroke simulator, a loud contact sound may be generated when the piston reaches the displacement end.

The present invention has been made in view of the above points, and has as its object to provide a brake stroke simulator that does not generate a large contact sound even when the brake pedal is operated at a high speed. And

[0009]

The above object is achieved by the present invention.
As described in the above, in a brake stroke simulator that sucks brake fluid in an amount corresponding to the supplied hydraulic pressure into a hydraulic chamber, the hydraulic chamber and the rear chamber are slidably disposed inside the housing. This is achieved by a brake stroke simulator that includes a separating piston and a damper that reduces the displacement speed of the piston when the displacement of the piston toward the rear chamber exceeds a predetermined distance.

In the present invention, when hydraulic pressure is supplied to the hydraulic chamber, brake fluid flows into the hydraulic chamber while displacing the piston toward the rear chamber. When the displacement of the piston toward the rear chamber exceeds a predetermined distance, the displacement speed of the piston is reduced by the function of the damper. For this reason,
Even if the hydraulic pressure supplied to the hydraulic chamber is rapidly increased, the piston does not reach the displacement end with a large displacement speed.

[0011]

FIG. 1 shows a system configuration diagram of a brake device provided with a brake stroke simulator 10 (hereinafter referred to as a stroke simulator 10) according to one embodiment of the present invention. The brake device shown in FIG. A master cylinder 14 is connected to the brake pedal 12. The master cylinder 14 includes therein a hydraulic pressure chamber that generates a master cylinder pressure P _{M / C} in accordance with the brake depression force applied to the brake pedal 12. Above the master cylinder 14, a reservoir tank 16 is provided. The hydraulic chamber of the master cylinder 14 is electrically connected to the reservoir tank 16 when the depression of the brake pedal 12 is released.

The suction side of a pump 18 communicates with the reservoir tank 16. An accumulator 20 communicates with the discharge side of the pump 18. In addition, accumulator 2
0 is in communication with the regulator 22. The regulator 22 is connected to the reservoir tank 16 together with the accumulator 20.
Is in communication with Regulator 22, by reducing the pressure of the accumulator pressure P _ACC is supplied from the accumulator 20, to generate a predetermined regulator pressure P _RE.

The brake device shown in FIG. 1 includes a hydraulic actuator 24. The hydraulic actuator 24 is
A master cylinder communication hole 26 is provided. The master cylinder 14 communicates with the master cylinder communication hole 26 via a hydraulic pipe 28. Inside the hydraulic actuator 24, there is a hydraulic passage 3 communicating with the master cylinder communication hole 26.
0 is formed.

The hydraulic pressure passage 30 has a liquid introduced therein.
Pressure, ie, master cylinder pressure P _{M / C}Detecting the hydraulic pressure
The sensor 31 is in communication. In the hydraulic passage 30,
The stroke simulator 10 is in communication. straw
The simulator 10 has a hydraulic chamber 34 and a back
A piston 32 that separates the chamber 36 is provided. In addition,
The structure of the trooke simulator 10 will be described in detail later.
I do.

The hydraulic chamber 34 of the stroke simulator 10
Communicates with the hydraulic passage 30. On the other hand, the rear chamber 36 of the stroke simulator 10 communicates with the low-pressure passage 38. The hydraulic actuator 24 has a low-pressure passage communication hole 40 communicating with the low-pressure passage 38. The low-pressure passage communication hole 40 communicates with the reservoir tank 16 via a hydraulic pipe 42.

The above-mentioned hydraulic passage 30 communicates with a left front wheel hydraulic passage 46 via a first master cut solenoid 44 (hereinafter referred to as SMC _- 144), and a second master cut solenoid 48 (hereinafter referred to as SMC _- 144). (Hereinafter referred to as SMC _- 248)
Through the right front wheel hydraulic passage 50. SMC _-1
Both 44 and SMC- ₂ 48 are two-position solenoid valves that realize a valve-open state in a normal state and receive a drive signal to achieve a valve-closed state.

The hydraulic actuator 24 includes a left front wheel communication hole 52 communicating with the left front wheel hydraulic pressure passage 46, and a right front wheel communication hole 54 communicating with the right front wheel hydraulic pressure passage 50.
A hydraulic pipe and a brake hose (hereinafter, these are collectively referred to as a brake hose 56) are provided in the left front wheel communication hole 52.
The wheel cylinder 58 of the left front wheel FL communicates with the left side. The right front wheel communication hole 54 is provided with a hydraulic pipe and a brake hose (hereinafter, these are collectively referred to as a brake hose 6).
0) communicates with the wheel cylinder 62 of the left front wheel FL.

The hydraulic actuator 24 has a regulator communication hole 64. The regulator communication hole 64 is
It communicates with the regulator 22 through a hydraulic line 66. A hydraulic passage 68 communicating with the regulator communication hole 64 is formed inside the hydraulic actuator 24.
The hydraulic passage 68, hydraulic pressure sensor 70 for detecting the regulator pressure P _RE supplied from the regulator 22 is communicated. The hydraulic passage 68 is provided with a linear pressure increasing solenoid 7.
2 (hereinafter, referred to as SLA 72) and communicates with the hydraulic passage 74. The SLA 72 is a linear control valve that linearly controls the flow rate of the brake fluid flowing from the hydraulic passage 68 to the hydraulic passage 74 based on a drive signal supplied from the outside.

Between the hydraulic passage 68 and the hydraulic passage 74,
A check valve 76 is provided in parallel with the SLA 72. The check valve 76 is a brake fluid that moves from the hydraulic passage 74 to the hydraulic passage 68 when the hydraulic pressure in the hydraulic passage 68 becomes lower than the hydraulic pressure in the hydraulic passage 74. This is a one-way valve that allows the flow of air. A linear pressure reducing solenoid 78 (hereinafter, referred to as SLR 78) communicates with the hydraulic pressure passage 74. An auxiliary reservoir 80 communicates with the SLR 78. The SLR 78 is a linear control valve that linearly controls the flow rate of the brake fluid flowing from the hydraulic passage 74 to the auxiliary reservoir 80 based on a drive signal supplied from the outside.

A check valve 82 is provided between the hydraulic passage 74 and the auxiliary reservoir 80 in parallel with the SLR 78. The check valve 82 is a one-way valve that allows the flow of brake fluid from the auxiliary reservoir 80 side to the hydraulic pressure passage 74 side when the hydraulic pressure in the hydraulic pressure passage 74 side decreases to near the atmospheric pressure. A hydraulic passage 84 communicates with the hydraulic passage 74. The hydraulic passage 84, hydraulic pressure sensor 86 for detecting the fluid pressure P _R to be derived from the fluid pressure passage 74 is disposed. Hydraulic P _R detected in the hydraulic pressure sensor 86, SLA
The pressure of the brake fluid 72 is increased by flowing the brake fluid from the fluid pressure passage 68 to the fluid pressure passage 74, and the pressure is reduced by opening the brake fluid from the fluid pressure passage 74 to the auxiliary reservoir 80 by the SLR 78.

The hydraulic passage 84 is provided with the rear wheel holding solenoid 8.
8 (hereinafter referred to as RrH88) and communicates with the rear wheel hydraulic pressure passage 90. RrH88 is a two-position solenoid valve that realizes the valve open state in a normal state and also realizes the valve closed state when a drive signal is supplied from the outside. Hydraulic passage 8
A check valve 92 is disposed between the rear wheel hydraulic pressure passage 4 and the rear wheel hydraulic pressure passage 90 in parallel with the RrH 88. The check valve 92 is a one-way valve that allows only the flow of the brake fluid from the rear wheel hydraulic pressure passage 90 toward the hydraulic pressure passage 84.

The hydraulic actuator 24 has a rear wheel communication hole 94 communicating with the rear wheel hydraulic pressure passage 90. A proportioning valve 96 (hereinafter, referred to as PV 96) communicates with the rear wheel communication hole 94 via a hydraulic pipe or the like. Further, wheel cylinders 98, 100 of the left and right rear wheels RL, RR communicate with the PV 96 via a brake hose or the like. When the hydraulic pressure guided to the hydraulic pressure passage 90 is less than a predetermined value, the PV 96 supplies the hydraulic pressure to the wheel cylinders 98 and 100 as it is, and the hydraulic pressure guided to the hydraulic pressure passage 90 decreases the predetermined value. If it exceeds, it is a valve that attenuates the fluid pressure at an appropriate rate and supplies it to the wheel cylinders 98,100.

The rear wheel hydraulic pressure passage 90 communicates with the above-described low pressure passage 38 via a rear wheel pressure reducing solenoid 102 (hereinafter, referred to as RrR102). RrR10
Reference numeral 2 denotes a two-position solenoid valve that realizes the valve-closed state in a normal state and realizes the valve-closed state by supplying a drive signal from the outside. The above-described hydraulic passage 84 communicates with a hydraulic passage 106 via a switching solenoid 104 (hereinafter, referred to as SS104). The SS 104 is a two-position solenoid valve that achieves the valve-closed state in a normal state and the valve-opened state by supplying a drive signal from the outside.

The hydraulic pressure passage 106 is connected to a hydraulic pressure sensor 108 for detecting a hydraulic pressure P _F introduced into the passage.
The hydraulic passage 106 is provided with the left front wheel holding solenoid 11.
0 (hereinafter, referred to as FLH 110), and communicates with the front left wheel hydraulic passage 46 via a right front wheel holding solenoid 112 (hereinafter, referred to as FRH 112). I have. FLH110 and FRH
Reference numeral 112 denotes a two-position solenoid valve that realizes the valve open state in a normal state and also realizes the valve closed state by supplying a drive signal from the outside.

Check valves 114 and 116 are disposed between the hydraulic passage 106 and the front left hydraulic passage 46 and between the hydraulic passage 106 and the front right hydraulic passage 50, respectively. . The check valve 114 is a one-way valve that allows only a fluid flow from the left front wheel hydraulic pressure passage 46 toward the hydraulic pressure passage 106. The check valve 116 is a one-way valve that allows only the flow of the fluid from the right front wheel hydraulic pressure passage 50 side to the hydraulic pressure passage 106 side.

The left front wheel hydraulic passage 46 communicates with the low pressure passage 38 via a left front wheel pressure reducing solenoid 118 (hereinafter, referred to as FLR 118). On the other hand, the right front wheel hydraulic passage 50
Is a right front wheel decompression solenoid 120 (hereinafter, FRR120).
) To the low-pressure passage 38. FLR
Both 118 and FRR 120 are two-position solenoid valves that realize a valve-closed state in a normal state and also realize a valve-opened state by supplying a drive signal from outside.

Next, the operation of the brake device shown in FIG. 1 will be described. In the brake device shown in FIG. 1, when the brake pedal 12 is depressed, the master cylinder 14 generates a master cylinder pressure PM _{/ C} corresponding to the brake depression force.
Therefore, when the brake pedal is depressed, the hydraulic pressure sensor 31 detects a hydraulic pressure exceeding a predetermined value. Therefore, according to the system of the present embodiment, when the hydraulic pressure sensor 31 detects a hydraulic pressure exceeding a predetermined value, it can be determined that the brake operation is being performed by the driver.

When the brake device shown in FIG. 1 determines that the brake operation is being performed by the driver, the SMC
_-1 44, SMC _-2 48, and SS 104 are turned on. Specifically, SMC _- 144 and SMC _- 248
Are closed and SS 104 is opened.
When the above processing is executed, the wheel cylinders 58, 62 of the left and right front wheels FL, FR are separated from the master cylinder 14, and all the wheel cylinders 58, 62, 9 are separated.
8, 100 is communicated with the hydraulic passage 84. In this case, the wheel cylinders 58, 6 of all wheels
2, 98 and 100 are supplied with hydraulic pressure adjusted by the SLA 72 and the SLR 78.

After the above processing is completed, the brake device shown in FIG. 1 calculates the braking force required by the driver based on the master cylinder pressure PM _{/ C} detected by the hydraulic pressure sensor 31. . Then, the SLA 72 and the SLR 78 are driven to control the wheel cylinder pressure P _{W / C} of each wheel so that the required braking force is generated. According to the above-described process, during the execution of the brake operation, the wheel 18 can generate an appropriate wheel cylinder pressure P _{W / C} using the pump 18 and the accumulator 20 as a hydraulic pressure source.

The braking system shown in Figure 1, when an abnormality is detected, SMC _-1 44 even during the execution of the braking operation, SMC _-2, and turn off the SS 104, that is, in FIG. 1 Maintain as shown. In the state shown in FIG. 1, the wheel cylinders 5 of the left and right front wheels FL, FR
Reference numerals 8 and 62 communicate with the master cylinder 14. Therefore, according to the state shown in FIG.
The hydraulic pressure can be supplied from the master cylinder 14 to the L and FR wheel cylinders 58 and 62. For this reason,
According to the brake device shown in FIG. 1, it is possible to exhibit excellent fail-safe performance against a system abnormality.

When the brake device shown in FIG. 1 is functioning normally and the brake operation is performed, the SMC _- 144 and the SMC _- 248 are switched to the ON state, that is, the valve is closed. Thereafter, the flow of brake fluid from the master cylinder 14 to the wheel cylinders 58, 62 is blocked. Brake pedal 12
Strokes when the brake fluid flows out of the master cylinder 14. Therefore, if the brake fluid cannot flow out of the master cylinder 14, the brake pedal 12 may not be able to stroke regardless of the presence or absence of the brake pedal force.

The brake device shown in FIG. 1 is provided with a stroke simulator 10 to avoid such inconvenience. That is, in the brake device shown in FIG.
The stroke simulator 10 has a master cylinder pressure P
The brake fluid of the amount corresponding to the _{M / C}
It is configured so that it can be inhaled. According to the above arrangement, when the brake pedal force is increased in a state where SMC _-1 44 and SMC _-2 48 are both in a closed state,
That is, when the master cylinder pressure P _{M / C} is increased, an amount of brake fluid corresponding to the increase in the master cylinder pressure P _{M / C} flows from the master cylinder 14 into the stroke simulator 10. When the brake fluid flows into the stroke simulator 10 from the master cylinder 14, the stroke of the brake pedal 12 increases according to the flow amount. Therefore, according to the brake device shown in FIG. 1, even both closed SMC _-1 44 and SMC _-2 48 is, by generating a proper stroke to the brake pedal 12, the proper brake operation feeling Can be realized.

When the brake fluid flows into the stroke simulator 10, displacement occurs in the piston 32 separating the hydraulic chamber 34 and the rear chamber 36 inside the stroke simulator 10. The displacement speed of the piston 32 increases as the flow speed of the brake fluid flowing into the stroke simulator 10 increases. Therefore, when the brake fluid 12 is operated at high speed and the inflow speed of the brake fluid becomes high, the piston 32 may be displaced with a high speed up to the displacement end.

When the piston 32 is displaced at a high speed to the displacement end, a large contact noise may be generated when the piston 32 reaches the displacement end. The stroke simulator 10 according to the present embodiment has a function of suppressing the displacement speed of the piston 32 when the piston 32 is displaced beyond a predetermined distance toward the rear chamber 36 in order to prevent the above-described contact sound from being generated. The feature is that it is provided with. Hereinafter, FIG.
With reference to FIG. 5 to FIG. 5, a characteristic part of the stroke simulator 10 of the present embodiment will be described.

FIG. 2 is a partial sectional view showing the hydraulic actuator 24 shown in FIG. 1 in a side view. As shown in FIG. 2, the hydraulic actuator 24 includes a housing 122. Inside the housing 122, the piston 3
2 are slidably housed. A hydraulic chamber 34 and a rear chamber 36 are formed on both sides of the piston 32. In this embodiment, the piston 32 has a cylindrical fitting projection 123 having a predetermined height on the end face on the side of the rear chamber 36.

A plug 124 for closing the opening of the rear chamber 36 is fitted into the housing 122. The plug 124 has a damper portion 126 having an outer diameter sufficiently smaller than the inner diameter of the rear chamber 36. The damper part 126 is formed with a through passage 128 that penetrates the damper part 126 in the vertical direction in FIG. Further, the sheet member 130 is press-fitted into the damper portion 126 from the end face side facing the piston 32. Sheet member 1
30 has a through hole 132 communicating with the through passage 128.

The end surface of the sheet member 130 and the damper member 1
A step of a predetermined length is formed between the end face 26 and the end face. As a result, a fitting recess 134 having a predetermined depth is formed on the end face of the damper member 126. In this embodiment, the fitting recess 134 is configured to fit with the fitting projection 123 provided in the piston 32. A ball valve 136 is provided inside the seat member 130. The ball valve 136 and the seat member 130 function as a one-way valve that allows the flow of brake fluid from the through passage 128 toward the fitting recess 134 and prevents the reverse flow.

Between the piston 32 and the plug 124,
A spring 138 is provided. Spring 138
Generates an urging force for urging the piston 32 toward the hydraulic chamber 34. When the internal pressure of the hydraulic chamber 34 is less than the predetermined value, the piston 32 is held at the original position shown in FIG. The stroke simulator 10 is designed such that when the piston 32 is at the home position, a predetermined length of space is formed between the piston 32 and the plug 124.

The rear chamber 36 has an opening 140 communicating with the reservoir tank 16 through the low-pressure passage 38. The inside of the rear chamber 36 is filled with brake fluid guided from the reservoir tank 16 through the opening 140. On the other hand, an opening 144 communicating with the master cylinder 14 via the hydraulic passage 30 is opened in the hydraulic chamber 34.

The piston 32 is displaced toward the rear chamber 36 when a high master cylinder pressure P _{M / C} is introduced from the opening 144 to the hydraulic chamber 34. Piston 32 is rear chamber 3
When displacing to the side 6, the brake fluid filled in the rear chamber 36 flows out to the reservoir tank 16 through the opening 140 and the low-pressure passage 38. When the displacement length of the piston 32 reaches a predetermined length, the fitting projection 1 of the piston 32
23 and the fitting recess 134 of the plug 124 start fitting. Then, the piston 32 can continue to be displaced until the end face of the piston 32 and the end face of the plug 124 come into contact with each other. Hereinafter, the displacement length of the piston 32 when the fitting protrusion 123 and the fitting recess 134 start fitting is referred to as a fitting start displacement. The position where the piston 32 contacts the plug 124 is referred to as the displacement end of the piston 32.

FIG. 3 shows a state in which the piston 32 has reached the vicinity of the displacement end. Before the displacement length of the piston 32 reaches the fitting start displacement, the pressure of the rear chamber 36, that is, the atmospheric pressure acts on all surfaces of the piston 32. Therefore, in such a situation, the relationship between the master cylinder pressure PM _{/ C} guided to the hydraulic chamber 34 and the displacement length of the piston 32 is substantially proportional.

When the displacement length of the piston 32 exceeds the fitting start displacement, the hydraulic pressure generated inside the fitting concave portion 134 acts on the fitting convex portion 123 of the piston 32. As described above, the seat member 130 and the ball valve 136 function as a one-way valve that blocks the flow of fluid from the fitting recess 134 toward the through passage 128. Therefore, the fitting recess 134
When the hydraulic pressure exceeding the atmospheric pressure is generated on the side, the brake fluid does not flow out from the fitting recess 134 side to the through passage 128.

Therefore, when the displacement length of the piston 32 further increases beyond the fitting start displacement, the fitting recess 134
Of the fitting recess 134
The path through which the liquid flows out from the
3 and only the clearance formed between the fitting recess 134. For this reason, when the displacement length of the piston 32 increases beyond the fitting start displacement, a hydraulic pressure higher than the atmospheric pressure is generated inside the fitting recess 134.

The hydraulic pressure generated inside the fitting recess 134 is
A force that presses the piston 32 toward the hydraulic chamber 34,
A force is generated in a direction that reduces the displacement speed of the piston 32. Further, in a region where the displacement length of the piston 32 exceeds the fitting start displacement, a higher hydraulic pressure is generated inside the fitting concave portion 134 as the displacement speed of the piston 32 is higher.
Therefore, according to the stroke simulator 10 of the present embodiment, after the displacement length of the piston 32 exceeds the fitting start displacement, the higher the displacement speed of the piston 32,
The displacement speed can be reduced.

FIG. 4 shows a state in which the piston 32 is displaced toward the original position after reaching the displacement end shown in FIG. In the process in which the piston 32 is displaced from the displacement end toward the original position, a liquid pressure lower than the atmospheric pressure is generated inside the fitting recess 134. The seat member 130 and the ball valve 136 are attached to the back recess 36 on the side of the fitting recess 134.
When a fluid pressure lower than the internal pressure is generated, the brake fluid is allowed to flow into the fitting recess 134 through the through passage 28. Therefore, the stroke simulator 1
The zero piston 32 can be easily displaced from the vicinity of the displacement end toward the original position by the low master cylinder pressure P _{M / C} guided to the hydraulic chamber 34.

FIG. 5 shows the relationship between the piston displacement length x realized by the stroke simulator 10 of the present embodiment and the brake depression force F. Stroke simulator 10
The characteristics described above can be expressed as shown in FIG. That is, in the stroke simulator 10,
After the brake operation is started, the displacement length x of the piston 32
And the piston 3
In the process in which 2 returns to the original position from the displacement end, a relation that can be expressed as F = k · x using the constant k is substantially established between the brake pedaling force F and the displacement length x of the piston 32. Further, in the process in which the displacement length x of the piston 32 increases beyond the fitting start displacement, a relationship that can be expressed as F = k × x + c (dx / dt) using the constants k and c between the two. Holds.

When the relationship shown in FIG. 5 is established between the displacement length x of the piston 32 and the brake depression force F, the brake depression force F is rapidly increased, that is, the brake pedal 12 is depressed at a high speed. Piston 3
2 can be prevented from reaching the displacement end with a high displacement speed, and the piston 32 can be smoothly returned to the original position when the brake depression force F is relaxed. For this reason, according to the stroke simulator 10 of the present embodiment, a good brake operation feeling can be realized without generating a large contact sound regardless of the operation speed of the brake pedal 12.

In the above embodiment, the plug 12
No. 4, fitting recess 134, seat portion 130, ball valve 13
6 and the fitting projection 123 of the piston 32 correspond to the “damper” of the first aspect. By the way, in the above embodiment, the fitting concave portion 134 and the fitting convex portion 12
Although the damper is realized by using 3 or the like, the configuration of the damper is not limited to this.
What is necessary is to reduce the displacement speed of the piston 32 in a region where the displacement length of the piston 32 exceeds a predetermined amount.

[0049]

As described above, according to the present invention, it is possible to prevent the piston from reaching the displacement end with a large displacement speed. Therefore, according to the present invention, a brake stroke simulator that does not generate a large contact sound can be realized.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a brake device configured using a brake stroke simulator 10 according to one embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a hydraulic actuator including a stroke simulator according to one embodiment of the present invention.

FIG. 3 is a diagram showing a state in which a piston is located near a displacement end in the stroke simulator according to one embodiment of the present invention.

FIG. 4 is a view showing a state where a piston is displaced from the vicinity of a displacement end toward an original position in a stroke simulator according to an embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between a displacement length of a piston and a brake depression force realized by a stroke simulator according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Stroke simulator 12 Brake pedal 14 Master cylinder 22 Regulator 32 Piston 34 Hydraulic room 36 Rear room 123 Fitting convex part 124 Plug 128 Penetrating passage 130 Seat member 134 Fitting concave part 136 Ball valve

Claims (1)

[Claims] 1. A brake stroke simulator for sucking brake fluid into a hydraulic chamber in an amount corresponding to a supplied hydraulic pressure, wherein the hydraulic chamber and the rear chamber are slidably disposed in a housing. A brake stroke simulator, comprising: a separating piston; and a damper for reducing a displacement speed of the piston when a displacement of the piston toward the rear chamber exceeds a predetermined distance.