JPH1159350A - Automotive brake pedal structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automotive brake pedal structure which, in the event of the head-on collision of a vehicle, can prevent impact load from working on a pedal arm via the push rod of a Master vac. SOLUTION: If a Master vac 9 is moved backward as the result of the head-on collision of a vehicle and accordingly an impact input works on a push-rod lever 11 via a push rod 10 in the backward direction, the backward rotation of the push rod lever 11 can be restrained and the input of the impact load to the pedal arm 2 can be avoided, since the push rod 10 is connected to the push rod lever 11 in such a manner that when the impact input exceeds a predetermined value, the push rod 10 is released from the push rod lever 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a brake pedal device for a motor vehicle.

[0002]

2. Description of the Related Art As shown in Japanese Utility Model Laid-Open Publication No. Hei 6-1113, for example, a brake pedal device for a motor vehicle includes a dash lower panel and a dash lower panel which pivotally support the upper end of a pedal arm. It is fastened and fixed to the lower part of the dash upper panel that is joined to the lower panel and protrudes toward the cabin, and pushes the pedal arm to push forward the push rod connected to the upper end of the pedal arm. , The master back is activated.

[0003]

When a master back or a dash lower panel to which the master back is fixed is deformed at the time of a frontal collision of the vehicle and the vehicle moves backward toward the passenger compartment,
A turning force in the reverse direction, which is opposite to the stepping direction, acts on the pedal arm via the push rod of the master back, and the depressed position of the brake pedal may shift rearward, causing a sense of incongruity.

Accordingly, the present invention is to prevent a collision load from acting on a pedal arm via a push rod of a master back at the time of a frontal collision of a vehicle, thereby avoiding an uncomfortable feeling. Is provided.

[0005]

According to a first aspect of the present invention, a pedal bracket fixed to a dash panel and a pedal shaft rotatably supported by a pedal shaft provided on the pedal bracket are urged to rotate backward. The pedal arm and the push rod lever rotatably supported by the pedal shaft and connected to the push rod of the master back, the pedal arm and the push rod lever are integrally connected, And a connecting portion between the push rod and the push rod lever, wherein the push rod is detached from the push rod lever when an input acting on the push rod lever in the backward direction via the push rod exceeds a predetermined value. It is characterized by.

According to a second aspect of the present invention, the push rod according to the first aspect is connected to the push rod lever via a pin, and the push rod lever has a pin connecting portion which is opened at the lower end of the push rod lever. A pin release guide slit is provided which has a groove and guides the pin downward when the input acting on the push rod lever in the backward direction via the push rod exceeds a predetermined value, and releases the pin from the slit opening at the lower end. It is characterized by:

According to a third aspect of the present invention, the pin opening of the pin detachment guide slit according to the second aspect is provided with a pin stopper which can be detached when an input acting from a pin sliding downward exceeds a predetermined value. It is characterized in that means are provided.

According to a fourth aspect of the present invention, the push rod according to the first aspect is connected to a push rod lever via a pin, and a push rod lever lower end is provided at a pin connecting portion of the push rod lever. A pin detachment guide slit having an opening is formed at a position above the pin connection portion of the pin detachment guide slit, and when an input acting on the pin exceeds a predetermined value, the push rod lever is disengaged from the pin. A deformation promoting slit for deforming the guide slit in a direction in which the guide slit expands is provided continuously.

According to a fifth aspect of the present invention, the push rod according to the first aspect is connected to a push rod lever via a pin, and a pin disengagement provided on the push rod lever so as to be inclined forward and downward. A guide slit, and forcible release means for converting downwardly the turning power of the push rod lever generated by an input acting on the push rod lever through the push rod to release the pin from the pin release guide slit. It is characterized by having.

In a sixth aspect, between the pedal arm and the push rod lever according to the first to fifth aspects, the pedal arm and the push rod lever are normally connected integrally in a normal state, It is characterized in that a clutch means for separating the pedal arm and the push rod lever by the detecting action of the collision detecting means is provided.

According to a seventh aspect, either one of the push rod lever and the pedal arm according to the sixth aspect is slidably supported in the axial direction of the pedal shaft, and the clutch means is connected to the pedal arm and the push arm. A meshing portion formed on an end face of a boss portion formed on each shaft support portion of the rod lever and engaging with each other, and a meshing portion of the push rod lever and the pedal arm is normally positioned so as to engage with each other, and a predetermined load is applied. And a positioning means capable of allowing one of the push rod lever and the pedal arm to move in the direction in which the engagement portion is disengaged along the axial direction of the pedal shaft. Features.

According to an eighth aspect of the present invention, the positioning means according to the seventh aspect is axially slidably supported by an arm shaft provided on the pedal bracket in parallel with the pedal shaft, and is provided with a push rod lever or a pedal. It is characterized by comprising a clutch arm connected to one of the arms, and a positioning member for positioning the clutch arm at a predetermined position in the axial direction of the arm shaft and displacing when a predetermined load is exceeded.

According to a ninth aspect of the present invention, the collision detecting means according to the eighth aspect is rotatably supported by the arm shaft and is arranged so as to protrude above the pedal bracket. As a result, the collision detection lever that rotates by engaging with the lower surface of the dash upper panel, and the collision detection lever that is formed on the end faces of the bosses formed on the respective shaft supports of the clutch arm and the collision detection lever and engage with each other, And a cam portion for moving the clutch arm along the axial direction of the arm shaft in a direction in which the engagement portion is disengaged against the positioning force of the positioning member by the rotation of the arm.

[0014]

According to the first aspect, the connecting portion between the push rod and the push rod lever is disengaged when a collision input acting on the push rod lever in the backward direction via the push rod exceeds a predetermined value. In the normal state, the pedal arm and the push rod lever rotate integrally by the depressing operation of the pedal arm, and the pedal force is transmitted to the master back via the push rod connected to the push rod lever in a normal state. However, not only can a master back operation be performed in the same manner as a general brake pedal device, but even if the master back moves backward due to a frontal collision of the vehicle, and the push rod moves backward accordingly, the collision input will not occur. When the pressure exceeds a predetermined value, the push rod is released from the push rod lever and separated. Collision load to the pedal arm by suppressing the rearward rotation of Doreba can be prevented from being input.

According to the second aspect, in addition to the effect of the first aspect, the detaching direction of the push rod detaching from the push rod lever can be reliably guided downward by the pin detachment guide slit. After the rod is disengaged from the push rod lever, the push rod can be prevented from interfering with peripheral components such as the steering member.

According to the third aspect, in addition to the effect of the second aspect, as long as the collision load transmitted via the push rod by the frontal collision of the vehicle by the pin retaining means does not exceed a predetermined value, the push rod lever can be used. Since the push rod can be prevented from coming off, reliability can be improved.

Further, even when the push rod lever and the push rod are sub-assembled and the push rod lever is attached to the pedal bracket, the push rod can be prevented from dropping off the push rod lever during the work. Installation workability can be improved.

According to the fourth aspect, in addition to the effect of the first aspect, when the push rod retreats due to a frontal collision of the vehicle and the collision load transmitted via the push rod exceeds a predetermined value, the push rod lever is moved. The pin release guide slit is expanded by the action of the deformation promoting slit provided in the portion above the pin connection portion, so that the pin is released from the pin release guide slit and the push rod is separated from the push rod lever. Therefore, the structure can be simplified and the cost can be advantageously obtained.

According to the fifth aspect, in addition to the effect of the first aspect, in addition to the effect of the first aspect, the rearward turning force of the push rod lever caused by the input acting on the push rod lever via the push rod due to the frontal collision of the vehicle is lowered. The push rod is forcibly disengaged from the push rod lever and is separated from the push rod lever because it is provided with a forced release means for releasing the pin from the pin release guide slit. Thus, it is possible to reliably prevent the collision load from being input to the pedal arm.

According to the sixth aspect, in addition to the effects of the first to fifth aspects, in a normal state, the pedal arm and the push rod lever are integrally connected by the clutch means. The pedal arm and the push rod lever rotate together to perform a master back operation which is the same as that of a general brake pedal device. Since the means operates and separates the pedal arm and the push rod lever,
Even if the master back moves backward or the dash lower panel is deformed to the cabin side and the push rod of the master back moves backward, the collision load is input to the pedal arm only by the swinging of the push rod lever. Can be avoided.

According to the seventh aspect, in addition to the effects of the sixth aspect, in addition to the effect of the sixth aspect, the clutch means is formed on the end surface of the boss portion of each of the shaft supports of the pedal arm and the push rod lever, and the clutch means of the push rod lever or the pedal arm. Either one is positioned along the axial direction of the pedal shaft so that the meshing portion is engaged, and is displaced when exceeding a predetermined load to allow movement in a direction in which the meshing portion is disengaged. Since the mechanical clutch structure is constituted by these means, the structure is simple and the cost can be advantageously obtained.

According to the eighth aspect, in addition to the effect of the seventh aspect, since the clutch arm of the positioning means slides in the axial direction along the arm shaft parallel to the pedal shaft, the push rod lever or the pedal arm is provided. The axial sliding on either one of the pedal shafts can be smoothly performed, and the clutch operation can be smoothly performed.

According to the ninth aspect, in addition to the effect of the eighth aspect, since the collision detecting means is mechanically constituted by the collision detecting lever and the cam portion, the structure is simple and the cost is advantageously obtained. be able to.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings.

In FIGS. 1 to 3, reference numeral 1 denotes a pedal bracket, and 2 denotes a pedal arm having an upper end rotatably supported on a pedal shaft 3 fixed to the pedal bracket 1, and a pedal pad (not shown) at the lower end. Have.

The pedal bracket 1 is formed in an inverted L-shape on the side. The front wall 1A is fastened and fixed to the dash lower panel 4 with bolts 7 and nuts 8, and the rear end of the upper wall 1B is connected to the rear end. Bolts 7, The nut 8 is fastened and fixed in a forwardly inclined state.

Reference numeral 9 denotes a push rod 10 which is fixed to a side of the dash lower panel 4 on the engine room side by a bracket or the like (not shown). The push rod 10 penetrating through the dash lower panel 4 is pushed by the pedal arm 2 to depress. 2 shows a master bag that generates hydraulic pressure in the brake unit of FIG.

The push rod 1 of the master bag 9
Numeral 0 is connected to the lower end of a push rod lever 11 rotatably supported on the pedal shaft 3 via a pin 12.

Particularly in this embodiment, as shown in FIG. 2, the pedal arm 2 and the push rod lever 11 are joined to a collar 13 at the upper end thereof, and fitted to the pedal shaft 3 to be integrated. To rotate.

Reference numeral 14 denotes a pin releasing guide slit. The pin releasing guide slit 14 lowers the pin 12 when the input acting on the push rod lever 11 in the backward direction via the push rod 10 at the time of a frontal collision of the vehicle exceeds a predetermined value. To the pin 1 through the slit opening at the lower end.
2 is detached to separate the push rod 10 from the push rod lever 11.

Further, in this embodiment, as shown in FIG.
When an input acting from the pin 12 sliding downwards exceeds a predetermined value, the pin 12 comes off, and a bolt / nut as a pin retaining means 15 for enabling the pin 12 to be detached is provided.

In FIG. 1, reference numeral 16 denotes a stopper for restricting backward rotation of the pedal arm 2, and reference numeral 17 denotes a dash insulator provided on a side surface of the dash lower panel 4 on the vehicle interior side.

According to the structure of the above embodiment, the connecting portion between the push rod 10 and the push rod lever 11 is connected to the push rod lever 11 via the push rod 10.
When the collision input acting in the backward direction exceeds a predetermined value, the pedal arm 2 and the push rod lever 11 which are integrally connected by the depressing operation of the pedal arm 2 are normally connected. By rotating, the pedaling force is transmitted to the master back 9 via the push rod 10 connected to the push rod lever 11 by the pin 12, and the master back operation which is the same as a general brake pedal device can be performed. Of course, even if the master back 9 moves backward due to the frontal collision of the vehicle and the push rod 10 moves backward accordingly, if the collision input exceeds a predetermined value, the push rod 10 is detached from the push rod lever 11 and separated. Therefore, the rearward rotation of the push rod lever 11 is suppressed, and the collision load is input to the pedal arm 2. It is possible to avoid that.

In the present embodiment, in particular, the release direction of the push rod 10 which is released from the push rod lever 11 is surely guided downward by the pin release guide slit 14. After detaching from the push rod lever 11, it is possible to avoid interference with peripheral parts such as a steering member (not shown).

Since the push rod 10 is connected at its end to a plunger (not shown) by a spherical joint in the master back 9, the end of the push rod 10 is connected to the push rod lever 11 in this manner. In the part, the connecting part can escape downward.

Further, since bolts and nuts as pin retaining means 15 are provided in the slit openings of the pin releasing guide slit 14, the load transmitted via the push rod 10 due to a frontal collision of the vehicle or the like can be reduced to a predetermined value. , The push rod 10 can be prevented from being detached from the push rod lever 11, and the reliability can be improved.

Further, even when the push rod lever 10 and the push rod 11 are sub-assembled and the push rod lever 11 is attached to the pedal bracket 1, the push rod 10 falls off the push rod lever 11 during the operation. Can be prevented, so that the mounting workability can be improved.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, the first embodiment shown in FIGS.
When the input acting on the pin of the push rod lever 11 in the embodiment above the pin detachment guide slit 14 of the pin detachment guide slit 14 exceeds a predetermined value, the pin detachment guide slit 14 of the push rod lever 11 expands. A deformation promoting slit 18 for deforming in the opening direction is provided continuously.

According to the structure of this embodiment, when the push rod 10 moves backward due to the frontal collision of the vehicle and the collision load transmitted through the push rod 10 exceeds a predetermined value, the slit 18 for promoting the deformation causes the push rod 10 to act. Since the pin release guide slit 14 is expanded and the pin 12 is released from the pin release guide slit 14 to separate the push rod 10 from the push rod lever 11, the structure can be simplified and the cost can be advantageously reduced. Obtainable.

FIG. 5 shows a third embodiment of the present invention. In this embodiment, the first embodiment shown in FIGS.
The pin release guide slit 14 of the push rod lever 11 of the embodiment is formed so as to face forward and obliquely downward, and the push rod lever 1 is inserted through the push rod 10.
Forcible release means is provided for converting the backward rotation force of the push rod lever 11 generated by the input acting on 1 to the downward direction and releasing the pin 12 from the pin release guide slit 14.

More specifically, a cable 19 is provided between the upper end of the push rod lever 11 and the connecting portion of the pin 12 and the push rod 10, and the pulley 20 is provided with the cable 19 on the pedal bracket 1. , 20.

Accordingly, the backward rotating force acting on the push rod lever 11 is converted into a force for pulling the push rod 10 downward through the cable 19, and the push rod 10 can be forcibly disengaged. .

According to the structure of this embodiment, the push rod 10 is forcibly disengaged from the push rod lever 11 and separated, so that the push rod lever 10 is restrained from turning backward and collides with the pedal arm 2. The input of the load can be reliably avoided.

FIGS. 6 and 7 show a fourth embodiment of the present invention in which the pedal bracket 1 is moved backward with the backward movement of the dash lower panel 4 due to the frontal collision of the vehicle in the structure of the second embodiment. The pedal arm 2 and the push rod lever 11 are detachably connected by a clutch structure.

Although the example used in the second embodiment is shown here, it goes without saying that it may be used in the first and third embodiments.

Specifically, a cylindrical collar 21 is fitted on the pedal shaft 3 via a bush (not shown), and a cylindrical boss 2 is provided on the upper end of the pedal arm 2.
2, and is rotatably fitted to the collar 21 via the boss portion 22.

The push rod lever 11 is provided with a cylindrical boss 23 at the upper end thereof. The push rod lever 11 is rotatably and axially slidable on the collar 21 of the pedal shaft 3 via the boss 23. It is fitted freely.

The pedal arm 2 and the push rod lever 11 are connected integrally in a normal state by a clutch means 24, but when the clutch means 24 is operated by a detection operation of a collision detection means described later, The pedal arm 2 and the push rod lever 11 are separated.

In this embodiment, a return spring (not shown) is stretched between the pin 12 of the push rod lever 11 and the pedal bracket 1, and the pedal is moved rearward to the pedal arm 2 via the push rod lever 11. Is turned on.

In this embodiment, the clutch means 24 is formed on the opposing end surfaces of the boss portion 22 of the pedal arm 2 and the boss portion 23 of the push rod lever 11 and engages with the engaging portion 25 which engages with each other. The push rod lever 11 is constituted by a positioning means 26 that urges the push rod lever 11 in the direction in which the engagement portion 25 is engaged, that is, toward the pedal arm 2 along the axial direction of the pedal shaft 3.

The positioning means 26 is provided with a clutch arm 27 for operating the push rod lever 11 in the axial direction of the collar 21, and the clutch arm 27 is pushed to one side to engage the push rod lever 11 with the engagement portion 25. 28 as a positioning member for urging in the axial direction in the axial direction
It consists of:

The clutch arm 27 has a cylindrical boss 29 and a fork 30, and an arm shaft 31 fixed to the pedal bracket 1 in parallel with the pedal shaft 3.
The fork portion 30 is rotatably fitted via the boss portion 29 and slidably in the axial direction of the arm shaft 31. The push rod lever 11 is connected to the upper and lower portions of the boss portion 23 so as to be able to move in the axial direction of the collar 21.

The spring 28 is mounted on the arm shaft 31 between one side wall of the pedal bracket 1 and the boss 29 of the clutch arm 27.

Numeral 32 denotes a collision detecting means for detecting and disconnecting the clutch means 24 in the event of a frontal collision of the vehicle. In this embodiment, the collision detecting means 32 is rotatably supported by the arm shaft 31 via a boss portion. A collision detection lever 3 whose upper end protrudes and is disposed near a front portion of the vehicle body side bracket 6 through a window 33 provided in the upper wall 1B of the pedal bracket 1.
4 and a cam portion 36 formed on the opposing end surfaces of the boss portion 35 of the collision detection lever 34 and the boss portion 29 of the clutch arm 27 and engaged with each other.

When the vehicle frontally collides and the pedal bracket 1 moves backward, the collision detection lever 34 engages with the front surface of the vehicle body-side bracket 6 and rotates. The arm 28 is moved along the axial direction of the arm shaft 31 against the spring force of the spring 28 to disengage the engagement portion 25 of the clutch means 24. That is, the spring 28 is displaced when a predetermined load is exceeded.

Therefore, the cam portion 36 is provided with the boss portions 29, 3
5 are formed as inclined surfaces at the same required lead angle so that they are in close contact with each other.

According to the structure of the above embodiment, the engaging portion 25 of the clutch means 24 is in the engaged state in the normal state, and the pedal arm 2 and the push rod lever 11 are integrally connected. When the pedal arm 2 is depressed, the pedal arm 2 and the push rod lever 11 rotate integrally, so that the push rod 10 is pushed and the master back 9 can be operated as in a general brake pedal device. .

On the other hand, when the vehicle collides head-on, the other functional components in the engine room interfere with the master back 9 and are pushed rearward, or the functional components in the engine room interfere with the dash lower panel 4. When the dash lower panel 4 is deformed toward the passenger compartment and the pedal bracket 1 is moved backward with the deformation of the dash lower panel 4 toward the passenger compartment, the collision detecting lever 34 of the collision detecting means 32 is moved to the front of the vehicle body side bracket 6. Engage and rotate forward.

When the collision detecting lever 34 rotates forward, the clutch arm 27 of the clutch means 24 moves axially on the arm shaft 31 against the spring force of the spring 28 by the guide action of the cam portion 36. The push rod lever 11 is moved by the clutch arm 27
The push rod lever 11 and the pedal arm 2 are separated from each other by moving in a direction in which the engagement of the push rod 5 is released.

As a result, even if the master back 9 moves backward and the push rod 10 exerts a rearward pressing force on the push rod lever 11, only the push rod lever 11 simply swings and swings. No collision load is input to the arm 2 and the pedal arm 2
It is possible to prevent a load acting on the driver's foot that has depressed the vehicle from causing an uncomfortable feeling or giving a shock.

In addition to the fact that the collision detecting means 32 is mechanically constituted by a collision detecting lever 34 pivotally supported on the arm shaft 31 and a cam portion 36, the clutch means 24 is also mechanically connected to the engaging portion 25 and the arm shaft 31. Mechanically constituted by the clutch arm 27 and the positioning means 26 comprising a spring 29, the structure can be simplified and the cost can be advantageously obtained.

Further, the vibration can be absorbed by the spring 28 and the rattling of the clutch arm 27 can be eliminated, so that the quality can be improved.

Further, since the clutch arm 27 slides in the axial direction along the arm shaft 31 parallel to the pedal shaft 3, the push rod lever 11 can smoothly slide in the axial direction on the pedal shaft 3. Thus, the clutch operation can be smoothly performed.

As the positioning member, a cylindrical collar which is deformed in the axial direction when a predetermined load is exceeded may be used instead of the spring 28 described above. In this case, the collar is deformed in the axial direction beyond the predetermined load. Thus, it is preferable to provide a trigger for deformation by providing a slit in the collar or the like.

In addition to the above, an electromagnetic clutch can be used as the clutch means 24, and a collision sensor for operating an airbag device usually mounted on a vehicle can be used as the collision detection means 32. it can.

In the above embodiment, the push rod lever 11 is slidable, but the pedal arm 2 may be slidable.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a sectional view of the embodiment.

FIG. 3 is an explanatory diagram of the embodiment.

FIG. 4 is an explanatory view of a second embodiment of the present invention.

FIG. 5 is a perspective view showing a third embodiment of the present invention.

FIG. 6 is a side view showing a fourth embodiment of the present invention.

FIG. 7 is an exploded perspective view showing a main part of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pedal bracket 2 Pedal arm 3 Pedal shaft 9 Master back 10 Push rod 11 Push rod lever 12 Pin 14 Pin detachment guide slit 15 Detachment prevention means (bolt / nut) 18 Deformation promotion slit 22 Pedal arm boss 23 Push rod lever Boss part 24 clutch means 25 meshing part 26 positioning means 27 clutch arm 29 boss part of clutch arm 31 arm shaft 32 collision detection means 34 collision detection lever 35 boss of collision detection lever 36 cam part

Claims (9)

[Claims] 1. A pedal bracket fixed to a dash panel, a pedal arm rotatably supported by a pedal shaft provided on the pedal bracket and energized in a rearward direction, and pivoted by the pedal shaft. In a structure having a push rod lever freely pivotally supported and connected to a push rod of a master back, the pedal arm and the push rod lever are integrally connected, and the push rod and the push rod lever are connected. Wherein the push rod is detached from the push rod lever when an input acting on the push rod lever in the backward direction via the push rod exceeds a predetermined value. 2. A push rod is connected to a push rod lever via a pin, and a pin connecting portion of the push rod lever is provided with an open groove at a lower end of the push rod lever, and the push rod is pushed through the push rod. 2. The vehicle according to claim 1, further comprising a pin detachment guide slit for slidingly guiding the pin downward when the input acting on the rod lever in the retreating direction exceeds a predetermined value and detaching the pin from the slit opening at the lower end. Brake pedal structure. 3. A pin releasing means which is provided at a slit opening of the pin releasing guide slit and which can be released when an input acting from a pin sliding downward exceeds a predetermined value. 4. The brake pedal structure for an automobile according to claim 1. 4. A push rod is connected to a push rod lever via a pin, and a pin release guide slit provided with a groove at a lower end of the push rod lever is provided at a pin connection portion of the push rod lever. In a portion formed above the pin connecting portion of the pin releasing guide slit, when the input acting on the pin exceeds a predetermined value, the deformation of the push rod lever in the direction in which the pin releasing guide slit expands is promoted. 2. The brake pedal structure for an automobile according to claim 1, wherein slits are provided in series. 5. A push rod connected to a push rod lever via a pin, a pin detachment guide slit provided on the push rod lever toward the front obliquely downward, and a push rod via the push rod. 2. A forcible release means for converting a backward rotating force of the push rod lever generated by an input acting on the lever downward to release the pin from the pin release guide slit. Car brake pedal structure. 6. In a normal state, the pedal arm and the push rod lever are integrally connected between the pedal arm and the push rod lever, and the pedal arm and the push rod lever are detected by a collision detecting means. A brake pedal structure for an automobile according to any one of claims 1 to 5, further comprising a clutch means for disconnecting the brake pedal. 7. A boss end face in which one of a push rod lever and a pedal arm is slidably supported in an axial direction of a pedal shaft, and a clutch means is formed on each shaft of the pedal arm and the push rod lever. And a meshing portion that is engaged with the push rod lever and the pedal arm. The meshing portion of the push rod lever and the pedal arm is positioned so that the meshing portion of the push rod lever and the pedal arm is normally engaged. 7. A vehicle brake according to claim 6, wherein the positioning means is capable of allowing one of the two to move in a direction in which the engagement portion is disengaged along the axial direction of the pedal shaft. Pedal structure. 8. A clutch arm, wherein the positioning means is axially slidably supported by an arm shaft provided on the pedal bracket in parallel with the pedal shaft and connected to either the push rod lever or the pedal arm.
8. A brake pedal structure for an automobile according to claim 7, wherein said clutch arm comprises a positioning member which is positioned at a predetermined position in the axial direction of said arm shaft and is displaced when a predetermined load is exceeded. 9. A collision detection means is rotatably supported by an arm shaft and is arranged to protrude above a pedal bracket. The collision detection means engages with the lower surface of the dash upper panel by retreating the pedal bracket by a collision load. The collision detection lever is formed on the end faces of the bosses formed on the shafts of the clutch arm and the collision detection lever, and engages with each other. The rotation of the collision detection lever opposes the positioning force of the positioning member. 9. A brake pedal structure for an automobile according to claim 8, wherein said clutch arm comprises a cam portion for moving said clutch arm in a direction in which said engagement portion is disengaged along the axial direction of said arm shaft.