CN118076522A - Pedal simulator - Google Patents

Abstract

The present invention relates to a pedal simulator, comprising: a cylinder body, in which a groove is formed, and one side of which is opened and the other side is closed; a piston inserted to one side of the cylinder to be movable forward and backward in conjunction with the operation of the pedal; a guide bush disposed at one side of the cylinder to reduce friction between the cylinder and the piston; a damper provided inside the cylinder to transmit a pedal feel to the electric booster by pressure applied from the piston; a push rod having one side connected to the pedal and the other side connected to the piston and moving the piston forward toward the damper in conjunction with the operation of the pedal; and a return means surrounding one side of the guide bush and a portion of the push rod and providing a restoring force for moving the push rod moving forward rearward.

Description

Pedal simulator

Technical Field

The present invention relates to a pedal simulator, and more particularly, to a pedal simulator that transmits a pedal operation of a driver to an electronic control system and provides a reaction force to the driver.

Background

Vehicles are basically equipped with a brake system for performing braking, and various modes of brake systems are proposed for safety of drivers and passengers.

The conventional brake system mainly adopts a manner of supplying hydraulic pressure required for braking to wheel cylinders by using a mechanically connected booster when a driver depresses a brake pedal.

However, as the market demand for various braking functions capable of closely responding to the operating environment of a vehicle has increased, in recent years, an electronic brake system configured to receive a braking intention of a driver as an electric signal from a pedal displacement sensor that senses a displacement of a pedal when the driver depresses the brake pedal, and operate a hydraulic pressure supply device based on the electric signal to supply hydraulic pressure required for braking to wheel cylinders has been widely used.

The electric brake system is provided with a simulator for forming a brake feel inside the electric booster. The simulator generates a brake feel by pressure generated by operating the master cylinder by a force transmitted when the driver depresses the brake pedal.

However, since the conventional simulator is provided inside the electric booster as described above, it is necessary to inevitably change the shape of the electric booster when it is desired to change the braking feel, but the configuration of the engine room is limited due to the large size of the electric booster, and the firewall inside the vehicle is also required to have a great rigidity due to the weight of the electric booster. As described above, there are many limitations in changing the brake feel of the simulator.

Disclosure of Invention

First, the technical problem to be solved

The present invention is directed to providing a pedal simulator which is separated from an electric control system, can improve the degree of freedom of installation, prevent the occurrence of impact and noise, and can transmit a pedal operation of a driver to the electric control system and provide a reaction force to the driver.

(II) technical scheme

According to one embodiment of the present invention, the pedal simulator of the present invention includes: a cylinder body, in which a groove is formed, and one side of which is opened and the other side is closed; a piston inserted to one side of the cylinder to be movable forward and backward in conjunction with the operation of the pedal; a guide bush disposed at one side of the cylinder to reduce friction between the cylinder and the piston; a damper provided inside the cylinder to transmit a pedal feel to the electric booster by pressure applied from the piston; a push rod having one side connected to the pedal and the other side connected to the piston and moving the piston forward toward the damper in conjunction with the operation of the pedal; and a return means surrounding one side of the guide bush and a portion of the push rod and providing a restoring force for moving the push rod moving forward rearward.

In addition, the cylinder includes a damper coupling portion formed to protrude from a position spaced apart from the other side of the cylinder by a predetermined distance, the damper being coupled to the damper coupling portion.

In addition, the damper coupling portion includes a damper coupling groove concavely formed at one surface thereof such that the damper is insertedly coupled to the damper coupling groove.

In addition, the damper coupling portion further includes one or more vent holes formed through the damper coupling portion in a direction parallel to a length direction of the cylinder body such that air of the inside of the cylinder body is discharged to the outside or external air flows into the inside of the cylinder body.

The cylinder may further include a pair of wing portions formed on an outer circumferential surface of the cylinder so as to extend in a direction intersecting a longitudinal direction of the cylinder, the wing portions being symmetrically formed with respect to a central axis extending in the longitudinal direction of the cylinder.

In addition, a through hole is formed in the wing part, the through hole being formed in a direction parallel to a length direction of the cylinder.

In addition, further comprising: and a fastening member penetrating the through hole and coupled to the cylinder, and fixing the cylinder to the vehicle.

In addition, the guide bush includes a bush body formed with a hollow in a length direction such that the piston is inserted therethrough.

In addition, the guide bush includes a lubricant flow path formed on an inner circumferential surface of the bush body and capable of storing lubricant, the lubricant flow path being recessed in a length direction of the bush body by a predetermined length from a position spaced apart from the other side of the bush body by a predetermined distance.

In addition, the lubricant flow paths are formed in plurality at a predetermined angle in the circumferential direction of the liner body.

In addition, the guide bush further includes a bush flange protruding from an outer circumferential surface of a position spaced apart from one side to the other side of the bush body by a predetermined distance and formed to extend in a circumferential direction of the bush body.

In addition, the reset device includes: a first elastic member surrounding the push rod and connected to one side of the guide bush, and moving the push rod backward by an elastic force; and a sheath surrounding the first elastic member and coupled to one side of the guide bush, and contracted and expanded with forward and backward movements of the piston.

In addition, the reset device further includes: and a second elastic member disposed inside the cylinder body to surround the damper, one side of the second elastic member being connected to the damper coupling portion, the other side being connected to the piston, and moving the piston rearward by elastic force.

In addition, the guide bush further includes a ventilation flow path so that air flows according to a volume change of the inside of the cylinder and the sheath caused by forward and backward movement of the piston.

In addition, the ventilation flow paths are concavely formed in the longitudinal direction on the inner peripheral surface of the liner body, and are formed in plurality at predetermined angles apart in the circumferential direction of the liner body.

In addition, the ventilation flow path is formed between the adjacent lubricant flow paths.

In addition, further comprising: and a filtering member provided at the other side of the cylinder to remove foreign matters in air flowing into the cylinder from the outside.

In addition, the filter member includes: a filter arranged in front of the damper coupling portion; and a filter fixing cover coupled to the cylinder body at a position opposite to the damper coupling portion to prevent the filter from being detached.

In addition, the piston includes a piston flange protruding from an outer circumferential surface of a position spaced apart from the other side by a predetermined distance, and formed to extend in a circumferential direction of the piston.

In addition, further comprising: and a stopper member disposed between the piston flange and the guide bush for absorbing impact generated when the piston moves forward and backward and preventing noise.

The details of other embodiments are contained in the detailed description and the accompanying drawings.

(III) beneficial effects

The pedal simulator according to the present invention has the following effects.

First, a pedal simulator separate from an electric control system (electric booster) can be realized, so that the degree of freedom of installation in the engine room can be improved.

Second, since the pedal simulator is separated from the electric booster, its size can be freely deformed to cope with various braking sensations.

Third, a guide bush may be provided between the piston and the cylinder, thereby preventing noise from being generated due to friction when the piston moves forward and backward.

Fourth, the ventilation means is provided, so that noise generated due to the air flow when the pedal simulator is operated can be prevented.

Fifth, a stopper member is provided so that it can absorb shock generated when the pedal simulator is operated and prevent noise.

Drawings

Fig. 1 is an exploded perspective view of a pedal simulator according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a pedal simulator in accordance with one embodiment of the present invention.

Fig. 3 is a partially enlarged perspective view showing a combined state of the wing part of the cylinder and the fastening member.

Fig. 4 is a perspective view showing the fastening member.

Fig. 5 is a partially enlarged sectional view showing the "a" portion of fig. 2 in an enlarged manner.

Fig. 6 is a perspective view and a partial sectional view of the guide bushing.

Fig. 7 is a perspective view showing the stopper member.

Fig. 8 is a partially enlarged perspective view showing a part of the cylinder and the filter member.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily implement the embodiments. The present invention may be implemented in a variety of different ways and is not limited to the embodiments described herein.

It is noted that the figures are schematic and not drawn to scale. The relative dimensions and proportions of parts of the drawings have been exaggerated or reduced in size, and any dimensions are merely illustrative and not restrictive in character, for the sake of clarity and convenience in the drawings. For the same structure, element, or component shown in more than two drawings, the same reference numerals are used to indicate similar features.

The embodiments of the present invention describe in detail the ideal embodiments of the present invention. Accordingly, various changes to the drawings are contemplated. Thus, embodiments are not limited to the particular morphology of the regions illustrated in the figures, but also include variations in morphology, for example, due to manufacturing.

Hereinafter, the pedal simulator according to the present invention will be described in detail with reference to fig. 1 to 8.

The pedal simulator 100 according to an embodiment of the present invention includes a cylinder 110, a piston 120, a guide bushing 130, a damper 125, a push rod 140, a return device 150, a fastening member, and a filter member 180.

The cylinder 110 is formed with a groove 111 inside, and one side of the cylinder 110 is opened and the other side is closed. The cylinder 110 includes a damper coupling portion 112, and the damper 125 is coupled to the damper coupling portion 112 such that the damper 125 may be disposed inside the cylinder 110.

The damper coupling portion 112 is formed to protrude toward one side of the cylinder 110 from a position spaced apart from the other side of the cylinder 110 by a predetermined distance. The damper coupling portion 112 includes: a first protrusion 112a protruding from the other side of the cylinder 110 to one side; and a second protrusion 112b protruding from the first protrusion 112 to one side of the cylinder 110.

The second protruding portion 112b intersecting the longitudinal direction has a smaller cross-sectional dimension than the first protruding portion 112a intersecting the longitudinal direction. A damper coupling groove 112c recessed toward the first protrusion 112a is formed at one side of the second protrusion 112b so that the damper 125 can be coupled to the damper coupling groove 112c.

A vent hole 112d is formed at the damper coupling portion 112 so that air inside the cylinder 110 is discharged to the outside or external air flows into the inside of the cylinder 110. Specifically, the vent hole 112d is formed through the first protrusion 112a in a direction parallel to the longitudinal direction of the cylinder 110. The ventilation holes 112d are formed in a plurality at predetermined angles apart in the circumferential direction of the first protruding portion 112a.

The cylinder 110 includes a wing 113. The wing 113 is used to mount the pedal simulator 100 in a vehicle. The wing 113 is formed to protrude from the outer circumferential surface of the cylinder 110. The wing 113 is formed to extend in a direction crossing the longitudinal direction of the cylinder 110. The wing parts 113 are symmetrically formed in a pair with respect to a central axis parallel to the longitudinal direction of the cylinder block 110.

The wing 113 may be formed in a plate shape having a predetermined thickness, and the shape of the wing 113 is not limited and may be formed in various shapes. A through hole 113a is formed in the wing 113, and the through hole 113a penetrates in a thickness direction parallel to a length direction of the cylinder 110. The fastening member 170 is coupled to the through hole 113a.

The pedal simulator 100 is mounted to a vehicle (not shown) through the fastening member 170. As described above, the fastening member 170 is inserted through the through hole 113a formed in the wing 113. When the pedal simulator 100 is to be mounted on the vehicle (not shown), the cylinder block 110 may be fixed to the vehicle (not shown) so as to mount the pedal simulator 100 on the vehicle (not shown) as long as the fastening member 170 is inserted into the vehicle (not shown).

On the other hand, the cylinder 110 is manufactured by Insert injection molding in a state of including the fastening member 170.

In this embodiment, the cylinder 110 is made of a plastic material. The conventional cylinder is made of a metal material such as aluminum or steel and the fastening members are coupled in a press-fit manner. However, in the present embodiment, as described above, the cylinder is made of a plastic material, and thus the wing 113 may be damaged during the press-in coupling of the fastening member 170. Accordingly, the cylinder block 110 is manufactured by insert injection molding in a state where the fastening member 170 is included, to ensure quality and durability of the cylinder block 110.

The fastening member 170 includes a head 171 and an insertion fixing portion 172. The head 171 is a portion inserted into the through hole 113a of the wing 113. A protrusion 171a is formed on the outer peripheral surface of the head 171. The protrusions 171a are continuously formed in the circumferential direction of the head 171. The protrusion 171a reduces the contact area between the fastening member 170 and the wing 113.

The insertion fixing portion 172 is formed to extend from one surface of the head 171. The insertion fixing portion 172 is a portion inserted into the vehicle (not shown), and the cylinder 110 is fixed by the insertion fixing portion 172. On the other hand, a step a (see fig. 3) of a predetermined pitch is formed between a surface of the head 171 and a surface of the wing 113, which form the insertion fixing portion 172.

When the pedal simulator 100 is mounted on the vehicle (not shown), if the wing 113 is in direct contact with the vehicle (not shown), a load generated during the mounting is transmitted to the wing 113, so that the wing 113 may be damaged.

However, by having the step a as described above, it is possible to prevent the wing 113 from being in direct contact with the vehicle (not shown) and to prevent a load generated during installation from being transmitted to the wing. In addition, as described above, by forming the protrusion 171a at the head 171, the contact area between the head 171 and the wing 113 can be reduced, and thus friction and load transmission between the fastening member 170 and the wing 113 can be reduced.

The piston 120 is inserted into one side of the cylinder 110 to move forward and backward in conjunction with the operation of the pedal. The piston 120 is not in direct contact with the cylinder 110 but is inserted into the guide bush 130, and the guide bush 130 is inserted into one side of the cylinder 110.

The piston 120 includes a piston body 121, and the piston body 121 is formed in a cylindrical state having a circular or polygonal cross section intersecting the longitudinal direction. In this embodiment, the piston body 121 is formed in a cylindrical shape. When the piston 120 moves forward, the other side of the piston 120 contacts the damper 130. A damper insertion groove 123 having the same shape as that of the damper 125 is formed at the other side of the piston body 121. Accordingly, when the piston 120 moves forward, one side of the damper 125 is inserted into the damper insertion groove 123.

The piston 120 includes a piston flange 122, and the piston flange 122 is formed to protrude from an outer circumferential surface of a position spaced apart from the other side of the piston body 121 by a predetermined distance. The piston flange 122 is formed to extend in the circumferential direction of the piston body 121. The piston 120 is prevented from being separated from the guide bush 130 to the outside by the piston flange 122.

A stop member 190 is provided between the piston flange 122 and the guide bushing 130. The stopper member 190 serves to absorb shock generated when the piston 120 moves forward and backward and to prevent noise. The stopper member 190 will be described in more detail later.

The damper 125 is disposed inside the cylinder 110. The damper 125 transmits a pedal feel to an electric booster (not shown) by the pressure applied by the piston 120.

As described above, when the piston 120 moves forward, the piston 120 contacts the damper 125 and applies pressure to the damper 125. Further, the damper 125 transmits a pedal feel to an electric booster (not shown) by the applied pressure. A pressure sensor (not shown) is provided in the electronic brake (not shown), and the pressure sensor (not shown) measures the pressure applied to the damper 125.

In addition, whether the damper 125 is broken or damaged may be determined by a value of the pressure applied to the damper 125 measured by the pressure sensor (not shown). For example, a pressure greater than or equal to a predetermined value should be measured at the damper 125, and if the pressure is not measured, it may be determined that the damper 125 is broken or damaged.

On the other hand, although not shown in the drawings, a force (force) sensor may be provided at the damper 125. The force sensor (not shown) may confirm whether the damper 125 is damaged by measuring the pressure applied to the damper 125.

The guide bush 130 is inserted into one side of the cylinder 110. The guide bush 130 is provided to reduce friction between the cylinder 110 and the piston 120.

The guide bush 130 includes a bush body 131, and the bush body 131 is formed with a hollow 131a in a length direction such that the piston 120 is inserted through the hollow 131 a. The bushing body 131 is made of a plastic material. The guide bushing 130 may store lubricant to reduce friction between the guide bushing 130 and the piston 120.

The guide bush 130 includes a lubricant flow path 132, and the lubricant flow path 132 is formed on an inner circumferential surface of the bush body 131 and is capable of storing a lubricant. The lubricant flow path 132 is formed to be recessed in a length direction of the bushing body 131 by a predetermined length from a position spaced apart from the other side to one side of the bushing body 131 by a predetermined distance.

The guide bushing 130 includes a bushing flange 133. The bush flange 133 is formed on the outer circumferential surface of the bush main body 131. Specifically, the liner flange 133 protrudes from an outer circumferential surface of a position spaced apart from one side of the liner body 131 to the other side by a predetermined distance and is formed to extend in a circumferential direction of the liner body 131. Accordingly, when the guide bush 130 is inserted into the cylinder 110, the guide bush 130 is caught by the bush flange 133.

A sheath coupling groove 133a is formed in the bush flange 133, and the sheath coupling groove 133a is recessed from the outer circumferential surface of the bush flange 133 and is formed to extend in the circumferential direction of the bush flange 133. One side of the sheath 152, which is one of the components of the reset device 150, is fitted and coupled to the sheath coupling groove 133a.

In another aspect, the guide bushing 130 further includes a seal coupling groove 134. The seal coupling groove 134 is formed on the outer circumferential surface of the bushing body 131. Specifically, the seal coupling groove 131 is recessed from an outer circumferential surface spaced apart from the other side of the bushing body 131 by a predetermined distance and is formed to extend in the circumferential direction of the bushing body 131.

A sealing member s is provided in the sealing coupling groove 134 to maintain airtightness between the cylinder block 110 and the guide bush 130.

When the guide bush 130 is inserted into one side of the cylinder block 110, one side end of the cylinder block 110 is fitted into a fixing groove (not shown) formed in the bush flange 133. Although not shown in detail in the drawings, a fixing groove (not shown) recessed and extending in the circumferential direction of the liner body 131 is formed at one surface of the liner flange 133 contacting one side end of the cylinder block 110.

The fixing groove (not shown) has a width equal to the thickness of one side end of the cylinder block 110, and the cylinder block 110 may be fixed to the guide bush 130 when an operator presses and fits one side of the cylinder block 110 into the fixing groove (not shown) using a clamping member (not shown).

A stop member 190 is provided between the piston 120 and the guide bush 130. Fig. 7 shows the stop member 190. The stopper member 190 is formed in a ring shape. One face 191 of the stop member 190 faces the guide bushing 130 and the other face 192 faces the piston flange 122 of the piston 120.

A protrusion 193 is formed on the one surface 191. That is, the protrusion 193 is in contact with the guide bush 130. The protrusions 193 are formed in plurality at predetermined angles on the one surface 191 in a circumferential direction of the stopper member 190. By forming the protrusion 193 on the stopper member 190, it is possible to reduce a contact area with the guide bush 130 and reduce noise generated when the piston 120 is separated from the guide bush 130 when it moves forward.

Grooves 194 are formed on both sides of the one surface 191 with reference to the protrusions 193. The groove 194 serves as an avoidance space in which a portion where the protrusion 193 is formed can be easily deformed, so that the piston 120 is brought into contact with the protrusion 193 before being brought into close contact with the one face 191. The stopper member 190 is made of a material having elastic force, and the pressing force of the other surface 192 and the piston flange 122 can be further improved when pressure is applied due to the formation of the groove 194. Like the protrusion 193, the grooves 194 are formed in plurality at predetermined angles apart in the circumferential direction of the stopper member 190.

As described above, the stopper member 190 has an effect of reducing noise while also functioning to absorb shock generated when the piston 120 moves forward and backward.

When the piston 120 moves backward, external air flows into the inside of the cylinder 110 and flows into the jacket 152 through the ventilation flow path 135. A filtering member 180 is provided at the other side of the piston 120 to remove foreign substances in the air when the external air flows into the inside of the cylinder 110.

The filter member 180 includes a filter 181 and a filter fixing cover 182. The filter 181 is disposed in front of the damper coupling portion 112. Foreign substances in the outside air are removed while passing through the filter 181.

The strainer fixing cover 182 is provided in front of the strainer 181 at a position facing the damper coupling portion 112 with reference to the strainer 181. The filter fixing cover 182 is coupled to the cylinder 110 to prevent the filter 181 from being detached from the cylinder 110.

Referring to fig. 8, a cover hole 182a is formed in the filter fixing cover 182. The cover holes 182a are formed in plurality at predetermined angles apart in the circumferential direction of the filter fixing cover 182. The external air flows in and through the filter 181 through the cover hole 182a.

Since the conventional pedal simulator is integrally formed with an electric booster (not shown), the pedal simulator can be connected to the pedal when the electric booster is incorporated into a Firewall (Firewall) in the vehicle. In particular, it has disadvantages in that it is necessary to have a pedal forming a circular track in a downward direction to connect, a space for an engine room needs to be secured, and a plurality of assembling persons (two) are required. Therefore, it is difficult to apply to organ pedals.

The pedal simulator according to the present embodiment is separate from the electric booster, and thus can also be connected to an organ pedal. An organ pedal is a pedal that forms a circular trajectory in the upward direction. The pedal simulator 100 according to the present embodiment has a degree of freedom of installation, and thus can be disposed and assembled obliquely downward at a predetermined angle with respect to an imaginary horizontal line passing through the axes of the organ pedal (not shown) and the pedal simulator 100.

The organ type pedal (not shown) can be installed by one operator, and thus the assembly condition can be improved.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that the present invention may be embodied in any other specific form without changing the technical spirit or essential features of the present invention.

It is, therefore, to be understood that the above-described embodiments are illustrative in all respects and not restrictive, and that the scope of the invention is to be determined by the appended claims, and all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (20)

1. A pedal simulator, comprising:

a cylinder body, in which a groove is formed, and one side of which is opened and the other side is closed;

a piston inserted to one side of the cylinder to move forward and backward in conjunction with the operation of the pedal;

A guide bush disposed at one side of the cylinder to reduce friction between the cylinder and the piston;

a damper provided inside the cylinder to transmit a pedal feel to the electric booster by pressure applied from the piston;

a push rod having one side connected to the pedal and the other side connected to the piston and moving the piston forward toward the damper in conjunction with the operation of the pedal; and

A return device surrounding one side of the guide bush and a portion of the push rod and providing a restoring force to move the push rod moving forward backward.

2. The pedal simulator of claim 1, wherein,

The cylinder body includes a damper coupling portion formed to protrude from a position spaced apart from the other side of the cylinder body by a predetermined distance, the damper being coupled to the damper coupling portion.

3. The pedal simulator according to claim 2, wherein,

The damper coupling portion includes a damper coupling groove concavely formed at one side thereof such that the damper is insertedly coupled to the damper coupling groove.

4. The pedal simulator of claim 3, wherein,

The damper coupling portion further includes one or more vent holes formed through the damper coupling portion in a direction parallel to a length direction of the cylinder body such that air of the inside of the cylinder body is discharged to the outside or external air flows into the inside of the cylinder body.

5. The pedal simulator of claim 1, wherein,

The cylinder further includes wing portions formed on an outer peripheral surface of the cylinder to extend in a direction intersecting a longitudinal direction of the cylinder, the wing portions being formed symmetrically with each other in a pair with respect to a central axis penetrating in the longitudinal direction of the cylinder.

6. The pedal simulator of claim 5, wherein,

A through hole is formed in the wing part, the through hole being formed in a direction parallel to a length direction of the cylinder.

7. The pedal simulator of claim 6, further comprising:

and a fastening member penetrating the through hole and coupled to the cylinder, and fixing the cylinder to the vehicle.

8. The pedal simulator of claim 1, wherein,

The guide bush includes a bush body formed with a hollow in a length direction such that the piston is inserted therethrough.

9. The pedal simulator of claim 8, wherein,

The guide bush includes a lubricant flow path formed on an inner circumferential surface of the bush body and capable of storing lubricant, the lubricant flow path being recessed by a predetermined length in a length direction of the bush body from a position spaced apart from the other side direction of the bush body by a predetermined distance.

10. The pedal simulator of claim 9, wherein,

The lubricant flow path is formed in plurality at a predetermined angle in a circumferential direction of the liner body.

11. The pedal simulator of claim 10, wherein,

The guide bush further includes a bush flange protruding from an outer circumferential surface of a position spaced apart from one side of the bush body to the other side by a predetermined distance and formed to extend in a circumferential direction of the bush body.

12. The pedal simulator of claim 9, wherein,

The resetting device comprises:

A first elastic member surrounding the push rod and connected to one side of the guide bush, and moving the push rod backward by an elastic force; and

A sheath surrounding the first elastic member and coupled to one side of the guide bush, and contracted and expanded with forward and backward movements of the piston.

13. The pedal simulator of claim 12, wherein,

The reset device further comprises:

And a second elastic member disposed inside the cylinder body to surround the damper, one side of the second elastic member being connected to the damper coupling portion, the other side being connected to the piston, and moving the piston rearward by elastic force.

14. The pedal simulator of claim 12, wherein,

The guide bush further includes a ventilation flow path so that air flows according to a volume change of the interior of the cylinder and the sheath caused by forward and backward movement of the piston.

15. The pedal simulator of claim 14, wherein,

The ventilation flow path is concavely formed in the length direction at the inner peripheral surface of the liner body, and is formed in plurality at a predetermined angle in the circumferential direction of the liner body.

16. The pedal simulator of claim 15, wherein,

The ventilation flow path is formed between adjacent lubricant flow paths.

17. The pedal simulator of claim 2, further comprising:

And a filtering member provided at the other side of the cylinder to remove foreign matters in air flowing into the cylinder from the outside.

18. The pedal simulator of claim 17, wherein,

The filter member includes:

A filter arranged in front of the damper coupling portion; and

A filter fixing cover coupled to the cylinder at a position opposite to the damper coupling portion to prevent the filter from being detached.

19. The pedal simulator of claim 1, wherein,

The piston includes a piston flange protruding from an outer circumferential surface of a position spaced apart from the other side by a predetermined distance, and formed to extend in a circumferential direction of the piston.

20. The pedal simulator of claim 19, further comprising:

and a stopper member disposed between the piston flange and the guide bush for absorbing impact generated when the piston moves forward and backward and preventing noise.