JP2017013571A - Stroke Simulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stroke simulator which can improve a brake feeling by a simple constitution.SOLUTION: A stroke simulator device 40 comprises a housing 41, a first piston 42 and a second piston 44. The first piston 42 comprises an elastic member 421 in which an annular groove 425 is formed, and which is pressure-inserted into the annular groove 425. An internal peripheral face of the housing 41 has a first pressing face in which the elastic member 421 presses the internal peripheral face of the housing 41 in a state that the first piston 42 is in an initial position, the internal peripheral face of the housing 41 has a second pressing face in which the elastic member 421 presses the internal peripheral face of the housing 41 in a state that the first piston is moved for a prescribed distance, and a first inside diameter being an inside diameter of the housing 41 at the first pressing face is larger than a second inside diameter being an inside diameter of the housing 41 at the second pressing face.SELECTED DRAWING: Figure 2

Description

The present invention relates to a stroke simulator that causes a brake pedal to generate a stroke having a magnitude corresponding to the operating force of the brake pedal.

In the conventional stroke simulator, the first piston, the second piston, and the rubber cap that move based on the hydraulic pressure corresponding to the operating force of the brake pedal of the driver in the housing, and the maximum movement of the rubber cap when the hydraulic pressure increases. A rubber receiving portion that regulates the range, and a first spring and a second spring that bias the first piston, the second piston, and the rubber cap in a direction that opposes the hydraulic pressure are provided. The inner peripheral portion of the housing is formed with a first simulator chamber defined by the housing and the first piston, and a second simulator chamber on the opposite side of the first simulator chamber. The first spring is disposed between the first piston and the second piston, and the second spring is disposed between the second piston and the rubber receiving portion. Further, the first piston has a substantially cylindrical shape, and a ring-shaped cup is attached to an annular groove formed on the surface of the cylinder, and the cup presses the inner periphery of the housing so as to be slidable in the axial direction. The first simulator room is sealed.

JP2007-210372

In the conventional stroke simulator described in Patent Document 1 described above, the first piston moves toward the rubber cap while compressing the first spring as the hydraulic pressure increases according to the operating force of the brake pedal of the driver. Then, while compressing the second spring, the second piston and the rubber cap move integrally to the rubber receiving portion side, and the repulsive force of the spring at this time gives the driver a predetermined brake feeling. Yes.

The rubber cap is provided with a rubber buffer elastic body, and the buffer elastic body is compressed just before the end of compression of the first spring and just before the end of compression of the second spring. The second curve is smoothly changed to give the driver a good brake feeling.

However, in the stroke simulator described in Patent Document 1 described above, since the operation force of the brake pedal at the initial stage of the brake operation by the driver is small, the cup attached to the first piston presses against the housing so as to be slidable in the axial direction. The effect of sliding resistance is large. As a result, the brake feeling felt by the driver differs between the initial brake operation state where the brake pedal operation force by the driver is small and the brake pedal operation force sufficient by the driver. This may give the driver a feeling of strangeness in the brake operation.

Accordingly, an object of the present invention is to provide a stroke simulator that can improve the brake feeling with a simple configuration.

In order to solve the above-mentioned problem, the invention according to claim 1 is a stroke simulator device for causing a brake pedal to generate a stroke having a magnitude corresponding to the operating force of the brake pedal. A first piston disposed in a fluid-tight manner so as to be slidable, a hydraulic pressure chamber formed on one end side of the first piston and supplied with a hydraulic pressure corresponding to the operating force of the brake pedal, and a first piston A second piston disposed at the other end and movable integrally with the first piston, and the first piston is formed with an annular groove on the outer peripheral surface, and is press-fitted into the annular groove and An elastic member that slidably presses against the inner peripheral surface, a stopper that restricts the range of movement of the second piston in the direction in which the volume of the hydraulic chamber increases, and the first piston and the second piston are disposed between the first piston and the second piston. The volume of the hydraulic chamber is reduced A first spring that biases the first piston in a direction that decreases and a second spring that biases the second piston in a direction that decreases the volume of the hydraulic chamber, and the brake pedal is not operated and the first piston Is in the initial position, the inner peripheral surface of the housing has a first pressing surface against which the elastic member presses the inner peripheral surface of the housing, and the brake pedal is operated and the first piston moves in a predetermined distance. The inner peripheral surface of the housing has a second pressing surface on which the elastic member presses the inner peripheral surface of the housing, and the first inner diameter that is the inner diameter of the housing on the first pressing surface is the housing inner surface on the second pressing surface. It is characterized by being set larger than the second inner diameter which is the inner diameter.

According to the first aspect of the present invention, the first inner diameter, which is the inner diameter of the housing when the brake pedal is not operated and the piston is in the initial position, is the inner diameter of the housing when the brake pedal is operated and the piston moves a predetermined distance. It is set larger than a certain second inner diameter. Thus, when a brake operation is performed by the driver, the pressing force between the elastic member and the inner peripheral surface of the housing at the initial operation of the brake pedal is increased as the brake pedal is operated and the piston moves a predetermined distance. Can do. Therefore, in the initial operation of the brake pedal, the sliding resistance between the cup seal and the inner peripheral surface of the housing can be reduced, and the resistance to the brake operation of the driver can be reduced, so that the brake feeling can be improved. Further, when the driver's operating force is sufficiently increased with the operation of the brake pedal, the influence of sliding resistance between the elastic member and the inner peripheral surface of the housing is small. There is no problem in increasing the pressing force, and the sealing performance by the elastic member can be ensured reliably according to the present invention.

Further, the hydraulic chamber side of the housing is formed with a third inner diameter smaller than the first inner diameter at a predetermined distance from the elastic member.

According to the invention of claim 2, the initial position of the first piston in the non-operating state of the brake pedal (same when the operation of the brake pedal is released) is a position where the first inner diameter and the third inner diameter are switched. It is determined. That is, the sliding resistance between the elastic member at the third inner diameter and the inner peripheral surface of the housing is greater than the sliding resistance between the elastic member at the first inner diameter and the inner peripheral surface of the housing. Axial movement to the chamber side can be restricted. For this reason, since the initial position of the first piston in the non-operating state of the brake pedal can be made constant, the brake feeling in the initial operation of the brake pedal can be made uniform, and the brake feeling can be improved. Can do.

Configuration diagram of a brake device using the stroke simulator according to the first embodiment of the present invention. Sectional view of the stroke simulator in FIG. 1 is an enlarged cross-sectional view of a cup seal portion in FIG. 1 is an enlarged cross-sectional view of a cup seal portion when the stroke simulator of FIG. 1 is operated. Sectional drawing of the stroke simulator of 2nd Embodiment in this invention

Hereinafter, although the 1st Embodiment of this invention is described concretely with FIGS. 1-3, this invention is not limited by the following embodiment, unless the meaning is exceeded.

FIG. 1 shows a brake device using a stroke simulator 40 according to the first embodiment of the present invention. In the figure, the hydraulic circuit of the brake device is shown for four wheels (FL, FR, RL, RR), but the configuration and operation of the parts related to brake hydraulic pressure control of each wheel are common, Here, only the left front wheel (FL) side will be described, and description of the configuration and operation related to the other wheels will be omitted.

The brake pedal 10 is depressed by a driver when a braking force is applied to the vehicle. The stroke sensor 20 detects a stroke of the brake pedal 10 (hereinafter referred to as a pedal stroke), and generates an electrical signal corresponding to the pedal stroke.

The master cylinder 30 generates brake fluid pressure when the brake pedal 10 is depressed, and this brake fluid pressure is transmitted to a stroke simulator 40 to be described later via a pipeline A, and is applied to the left front wheel via a pipeline B. It is transmitted to the wheel cylinder 50.

The pipe A is provided with a first cut valve 80 for opening and closing the pipe A. The first cut valve 80 is a normally closed electromagnetic valve.

The pipe B is provided with a second cut valve 61 that is a normally open electromagnetic valve that opens and closes the pipe B. Hereinafter, in the pipeline B, the portion between the second cut valve 61 and the master cylinder 30 is referred to as an M / C side pipeline B1, and the portion between the second cut valve 61 and the wheel cylinder 50 is a W / C side pipeline B2. That's it.

A first pressure sensor 62 that detects a brake fluid pressure in the M / C side conduit B1 is disposed in the M / C side conduit B1, and the first pressure sensor 62 is an electric signal corresponding to the brake fluid pressure. Is generated. The W / C side pipe B2 is provided with a second pressure sensor 63 for detecting the brake fluid pressure in the W / C side pipe B2, and the second pressure sensor 63 corresponds to the brake fluid pressure. Generate electrical signals.

A pipe C is connected to the W / C side pipe B2. In this pipeline C, a pump 71, an accumulator 72, a relief valve 73, and a third pressure sensor 74 for detecting the brake fluid pressure in the pipeline C are disposed as a hydraulic pressure source 70 that generates brake fluid pressure. The third pressure sensor 74 generates an electrical signal corresponding to the brake fluid pressure. The hydraulic pressure source 70 sucks and discharges brake fluid from the reservoir of the master cylinder 30 by a pump 71 driven by an electric motor, stores the discharged high-pressure brake fluid in the accumulator 72, and also adjusts the pressure of the brake fluid. The pressure is detected by the third pressure sensor 74 and adjusted to the set pressure.

In the line C, a pressure increasing valve 81 for opening and closing the pressure increasing line C1 is disposed in the pressure increasing line C1 from the third pressure sensor 74 to a portion connected to the W / C side line B2. When the pressure increasing valve 81 is opened, high-pressure brake fluid is supplied from the hydraulic pressure source 70 to the wheel cylinder 50, and the brake fluid pressure of the wheel cylinder 50 increases. The pressure increasing valve 81 is a normally closed solenoid valve.

In the line C, a pressure reducing valve 82 for opening and closing the pressure reducing line C2 is disposed in the pressure reducing line C2 from the portion connected to the W / C side line B2 to the suction side of the hydraulic pressure source 70. Yes. When the pressure reducing valve 82 is opened, the brake fluid in the wheel cylinder 50 is returned to the suction side of the fluid pressure source 70 or the reservoir of the master cylinder 30, and the brake fluid pressure in the wheel cylinder 50 is reduced. The pressure reducing valve 82 is a normally closed electromagnetic valve.

Next, the stroke simulator 40 which is 1st Embodiment is demonstrated based on FIG. 2 and FIG. FIG. 2 shows a state where the brake pedal 10 is not operated, and shows a state when the pressure in the hydraulic chamber 43 is 0 (that is, atmospheric pressure).

The stroke simulator 40 is for generating a pedal stroke having a magnitude corresponding to the operating force of the brake pedal 10. The housing 41 of the stroke simulator 40 has two cylindrical holes 411 and 412 formed therein. These holes 411 and 412 are coaxially arranged in series.

In the first hole 411, a substantially cylindrical first piston 42 formed of an inelastic member such as S45C is slidably disposed. The inelastic member referred to in the present specification has a remarkably small amount of elastic deformation compared to rubber, and can be regarded as a rigid body in practice, and corresponds to metal and hard resin.

An annular groove 425 is formed on the outer circumferential surface of the first piston 42, and a cup seal 421 that seals between the inner circumferential surface of the first hole 411 and the outer circumferential surface of the first piston 42 in the annular groove 425. It is arranged. The cup seal 421 is formed of an elastic member and is made of, for example, ethylene / propylene / diene copolymer rubber (EPDM). The cup seal 421 corresponds to the elastic member of the present invention.

As shown in FIG. 3, the cup pedal 421 has a first pressing surface 70 that presses the inner peripheral surface of the housing 41 when the brake pedal 10 is not operated and the first piston 42 is in the initial position.

As shown in FIG. 4, the brake pedal 10 is operated and the first piston 42 is moved a predetermined distance A in the X direction (volume increasing direction X). At this time, it has the 2nd press surface 71 in which the cup seal 421 presses the inner peripheral surface of the housing 41 formed by the 2nd internal diameter C (refer FIG. 1). Here, the predetermined distance A is set as an axial distance necessary for forming the second pressing surface 71, and the predetermined distance A in this embodiment is the first pressing surface 70 and the second pressing surface 71. The distance between the X-side ends is shown.

The first inner diameter B, which is the inner diameter of the housing on the first pressing surface 70, is set larger than the second inner diameter C, which is the inner diameter of the housing 41 on the second pressing surface 71.

Further, a tapered portion 80 is formed on the X direction side of the first pressing surface 70 so as to extend toward the axis of the housing 41 and smoothly connect the first pressing surface 70 and the second pressing surface 71.

A hydraulic chamber 43 is formed between the bottom of the first hole 411 and one end surface of the first piston 42, and the brake hydraulic pressure is transmitted from the master cylinder 30 to the hydraulic chamber 43 via the pipe A. It has become so.

A cylindrical second piston 44 with a flange is disposed in the second hole 412 so as to face the other end surface of the first piston 42. When the first piston 42 moves in the direction X direction in which the volume of the hydraulic pressure chamber 43 increases as the brake hydraulic pressure increases, the second piston 44 contacts the first piston 42 and the second piston 44. It moves integrally with the first piston 42 from the time of contact.

A substantially cylindrical stopper 45 formed of an inelastic member such as aluminum is disposed in the opening of the second hole 412 so as to face the other end surface of the second piston 44. The stopper 45 regulates the movement range of the second piston 44 in the X direction. An O-ring 451 made of, for example, ethylene / propylene / diene copolymer rubber (EPDM) is disposed on the outer periphery of the stopper 45, and a circlip 452 for preventing the stopper 45 from being detached is disposed on the end of the stopper 45. It is installed. The second hole 412 is opened to the atmosphere by a through hole 413, and a waterproof pipe 414 for preventing water from entering the second hole 412 is attached to the through hole 413.

Between the 1st piston 42 and the 2nd piston 44, the 1st spring 46 which urges | biases the 1st piston 42 in the direction Y (volume decreasing direction Y) where the volume of the hydraulic pressure chamber 43 reduces is arrange | positioned. Yes. The first spring 46 is a cylindrical compression coil spring made of spring steel, for example.

Between the 2nd piston 44 and the stopper 45, the 2nd spring 47 which urges | biases the 2nd piston 44 to the Y direction side is arrange | positioned. The second spring 47 is a cylindrical compression coil spring made of spring steel, for example. The spring constant of the second spring 47 is different from that of the first spring 46, and the spring constant of the second spring 47 is set to be larger (for example, about 10 times) than the spring constant of the first spring 46.

A surface of the first piston 42 facing the second piston 44 is fitted with a spring receiving surface 422 that supports one end of the first spring 46 and one end of the first spring 46 so that the radial direction of the first spring 46 is increased. A cylindrical first fitting portion 423 that restricts the movement range is formed. The outer diameter of the first fitting portion 423 is set to be larger than the inner diameter of the first spring 46 in the free state. Therefore, the first spring 46 is press-fitted into the first fitting portion 423 and assembled. Yes.

The second piston 44 has a disk-shaped flange 441 at its axially intermediate portion, and supports the other end of the first spring 46 by one spring receiving surface 442 of the flange 441, One end of the second spring 47 is supported by the other spring receiving surface 443.

The second piston 44 protrudes from the flange portion 441 toward the first piston 42 side, and from the cylindrical first protrusion 444 and the flange portion 441 that can come into contact with the front end surface of the fitting portion 423 of the first piston 42. A cylindrical second protrusion 445 that protrudes toward the stopper 45 and can come into contact with the movement range regulating surface 454 of the stopper 45 is provided.

Note that the front end surface of the fitting portion 423 of the first piston 42 and the front end surface of the first protrusion 444 of the second piston 44 when the brake pedal 10 is not operated and the hydraulic pressure in the hydraulic chamber 43 is zero. The distance in the movement direction between the first stroke and the second stroke is the first stroke. In addition, the movement direction distance between the tip end surface of the second protrusion 445 of the second piston 44 and the movement range regulating surface 454 of the stopper 45 in the state where the hydraulic pressure is 0 is the second stroke.

The first protrusion 444 of the second piston 44 is for fitting the other end of the first spring 46 to restrict the radial movement range of the first spring 46. The outer diameter of the first protrusion 444 is set to be smaller than the inner diameter of the first spring 46 in the free state. Therefore, the first spring 46 is assembled to the first protrusion 444 in a non-press-fit state. .

On the surface of the stopper 45 that faces the second piston 44, a spring receiving surface 453 that supports the other end of the second spring 47 and a movement range regulating surface that can contact the tip of the second protrusion 445 of the second piston 44. 454 and a cylindrical guide portion 455 projecting from the spring receiving surface 453 and the movement range regulating surface 454 toward the second piston 44 side are formed. A second protrusion 445 of the second piston 44 is slidably inserted in the inner peripheral portion of the guide portion 455, and thereby the second piston in a direction orthogonal to the moving direction of the second piston 44. The movement range of 44 is regulated.

In FIG. 2, a hole 424 is formed on the fitting portion 423 side of the first piston 42, and a columnar first buffer elastic body 90 is inserted into the hole 424. One end of the first buffer elastic body 90 protrudes from the hole 424 toward the second piston 44 when the hydraulic pressure is zero.

A cylindrical second buffer elastic body 100 is disposed on the outer periphery of the second protrusion 445 in the first piston 42. One end of the second buffer elastic body 100 protrudes toward the movement range regulating surface 454 side of the stopper 45 from the tip surface of the second protrusion 445 in a state where the hydraulic pressure is zero.

The first buffer elastic body 90 and the second buffer elastic body 100 are made of a material having a remarkably large amount of elastic deformation compared to metal or hard resin, more specifically rubber, and more specifically, for example, ethylene, propylene, diene. It consists of polymer rubber (EPDM).

Next, the operation of the brake device configured as described above will be described.

First, the operation of the portion excluding the stroke simulator 40 will be described with reference to FIG. When the brake pedal 10 is depressed when there is no abnormality in the brake device, the stroke sensor 20 detects that the brake pedal 10 has been depressed, and the second cut valve 61 is closed to close the pipeline B.

When the depression of the brake pedal 10 is released, it is detected by the stroke sensor 20 that the depression of the brake pedal 10 is released, the second cut valve 61 is opened, and the pipe line B is opened.

Next, the operation of the stroke simulator 40 according to the first embodiment will be described with reference to FIG.

When there is no abnormality in the brake device, for example, it is detected that the door of the vehicle is opened, and the first cut valve 80 of the stroke simulator 40 is opened by an ECU (electronic control unit) not shown in the figure. A is opened so that the brake fluid pressure is transmitted from the master cylinder 30 to the fluid pressure chamber 43 via the pipe A.

When the brake pedal 10 is operated, the brake hydraulic pressure transmitted to the hydraulic pressure chamber 43 acts on the first piston 42 and biases the first piston 42 in the X direction side. The first piston 42 starts moving in the X direction against the spring force of the first spring 46 and the second spring 47 as the brake fluid pressure increases.

At this time, in the initial stage where the first piston 42 starts moving in the X direction from the state in which the brake pedal 10 is not operated and the first piston 42 is in the initial position, the above-described first inner diameter B is the brake pedal 10. Is set to be larger than the second inner diameter C in a state where the first piston 42 has moved a predetermined distance A.

As a result, the pressing force between the cup seal 421 and the inner peripheral surface of the housing in the initial operation of the brake pedal 10 can be increased as the brake pedal 10 is operated and the first piston 42 moves a predetermined distance A. . Therefore, in the initial operation of the brake pedal 10, the sliding resistance between the cup seal 421 and the inner peripheral surface of the housing 41 can be reduced, and the resistance to the brake operation of the driver can be reduced, so that the brake feeling can be improved. . Further, when the driver's operating force is sufficiently increased as the brake pedal 10 is operated, the influence of the sliding resistance between the cup seal 421 and the inner peripheral surface of the housing is small. There is no problem in increasing the peripheral surface and the pressing force, and the sealing performance by the cup seal 421 can be reliably ensured by the above configuration.

Further, during the movement of the first piston 42 in the X direction side, the spring constant is maintained until the front end surface of the fitting portion 423 of the first piston 42 contacts the front end surface of the first protrusion 444 of the second piston 44. Since the first spring 46 having a small is mainly compressed, the change amount of the pedal stroke with respect to the change amount of the pedal operation force becomes large.

From the time when the first piston 42 and the second piston 44 come into contact with each other, the first piston 42 and the second piston 44 are such that the tip end surface of the second protrusion 445 of the second piston 44 is the movement range regulating surface 454 of the stopper 45. It moves integrally until it contacts. At this time, the change amount of the pedal stroke with respect to the change amount of the pedal operating force by which the second spring 47 having a large spring constant is compressed becomes small.

Then, after the tip end surface of the second protrusion 445 of the second piston 44 comes into contact with the movement range regulating surface 454 of the stopper 45, the pedal stroke does not change even if the pedal operating force increases.

When the second piston 44 moves, the second protrusion 445 of the second piston 44 is guided by the guide portion 455 of the stopper 45. As a result, the movement range of the second piston 44 in the direction orthogonal to the movement direction of the second piston 44 is restricted and the inclination of the second piston 44 is prevented, so that the simulator characteristics are stabilized.

The operation when an abnormality occurs in the brake device will be described with reference to FIG. For example, when an abnormality such as failure of the hydraulic pressure source 70 occurs, the first cut valve 80, the pressure increasing valve 81, and the pressure reducing valve 82 are closed, and the second cut valve 61 is opened. In this state, when the brake pedal 10 is depressed, the brake fluid is supplied from the master cylinder 30 to the wheel cylinder 50 via the pipe B, and braking can be performed.

By the way, with the above configuration, when the operation of the brake pedal 10 is released, the first piston 42 and the second piston move in the axial direction to the Y direction side by the urging force of the first spring 46 and the second spring 47, respectively. A pressing force is applied. Thereby, the 1st piston 42 and the 2nd piston 44 return to an initial position.

The initial position of the first piston 42 is determined by the sliding resistance between the cup seal 421 and the inner peripheral surface of the housing 41. For this reason, the initial position of the first piston 42 does not become constant due to the contact state of the cup seal 421 with the inner peripheral surface of the housing 41 and variations in molding. As a result, in the initial operation of the brake pedal 10, the brake feeling is different each time the brake pedal 10 is operated, which may give the driver a feeling of strangeness.

On the other hand, in the second embodiment of the present invention shown in FIG. 5, not only the taper portion 80 on the X direction side of the first pressing surface but also on the Y direction side (hydraulic pressure chamber 43) of the cup seal 421. A tapered portion 81 is formed, and a third inner diameter is formed in which the inner diameter of the housing 41 is smaller than the first inner diameter B (see FIG. 2). In addition, the position of the taper part 81 can be arbitrarily set as the initial position of the first piston 42.

That is, the sliding resistance between the cup seal 421 and the inner peripheral surface of the housing 41 at the third inner diameter D is greater than the sliding resistance between the cup seal 421 and the inner peripheral surface of the housing 41 at the first inner diameter B. The first piston 42 can be restricted from moving axially toward the hydraulic pressure chamber 43 side. For this reason, the initial position of the first piston 42 when the operation of the brake pedal 10 is released is determined by the tapered portion 81 and the third inner diameter D. Thereby, since the initial position of the first piston 42 can be set to a fixed position, the brake feeling can be made uniform in the initial operation of the brake pedal 10, and the brake feeling can be improved.

In the second embodiment, the second inner diameter and the third inner diameter are the same. However, the second inner diameter and the third inner diameter may be different from each other.

10 brake pedal 41 housing 42 first piston 43 hydraulic chamber 44 second piston 46 first spring 47 second spring 70 pressing surface 80, 81 taper part A predetermined movement distance B of piston first inner diameter C second inner diameter D third Inner diameter

Claims (2)

A stroke simulator device for causing the brake pedal to generate a stroke having a magnitude corresponding to the operating force of the brake pedal,
A housing;
A first piston slidably disposed in the housing in a liquid-tight manner;
A hydraulic chamber formed on one end side of the first piston and supplied with a hydraulic pressure corresponding to the operating force of the brake pedal;
A second piston disposed at the other end of the first piston and movable integrally with the first piston;
The first piston is formed with an annular groove on the outer peripheral surface, and is elastically pressed into the annular peripheral groove and slidably pressed on the inner peripheral surface of the housing;
A first spring disposed between the first piston and the second piston and biasing the first piston in a direction in which the volume of the hydraulic chamber decreases; and a direction in which the volume of the hydraulic chamber decreases. And a second spring for biasing the second piston,
In a state where the brake pedal is not operated and the first piston is in an initial position, the inner peripheral surface of the housing has a first pressing surface on which the elastic member presses the inner peripheral surface of the housing,
In a state where the brake pedal is operated and the first piston moves a predetermined distance, the inner peripheral surface of the housing has a second pressing surface on which the elastic member presses the inner peripheral surface of the housing,
A stroke simulator device, wherein a first inner diameter that is an inner diameter of the housing on the first pressing surface is larger than a second inner diameter that is an inner diameter of the housing on the second pressing surface. 2. The stroke simulator device according to claim 1, wherein the hydraulic pressure chamber side of the housing is formed with a third inner diameter smaller than the first inner diameter at a predetermined distance from the elastic member.