JPH10310035A - Braking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To positively reduce a load to which the foot of a driver is subjected to from a brake pedal at the time when cars collide. SOLUTION: A push rod 10 of a negative pressure booster B connected to a brake pedal 12 is arranged so that its axis line L is tilted from the horizontal plane in an up and down direction. The push rod 10 is not bent even when usual treading force is applied to the brake pedal 12, but when the negative pressure booster B is retracted to apply a great axial compressive force to the push rod 10 when cars collide, the push rod 10 is bent to rotate the brake pedal 12 forward. Thus, the push-up of the brake pedal 12 to the cabin side due to retraction of a master cylinder M is prevented to reduce the load applied to the foot of a driver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake apparatus for an automobile, which brakes wheels with brake hydraulic pressure generated by a brake hydraulic pressure generating means by operating a brake pedal.

[0002]

2. Description of the Related Art A brake pedal of an automobile is supported by a dashboard rising from a floor panel.
When the dashboard retreats to the passenger compartment together with the brake pedal due to the impact of the automobile collision, a load may be applied to the driver's foot on the brake pedal. In order to reduce the load applied to the driver's feet in such a case, the pedal bracket that rotatably supports the upper end of the brake pedal and the dashboard are separably connected by impact, and separated from the dashboard in the event of a collision. Japanese Patent Application Laid-Open No. H06-211115 discloses a method in which a pedal bracket is rotated forward together with a brake pedal to reduce the load.
It is publicly known from Japanese Patent Publication No.

[0003]

However, since the degree of deformation and the magnitude of the deformation of the dashboard vary depending on the state of collision, the above-mentioned prior art can reliably separate the bracket from the dashboard depending on the state of collision. Therefore, there is a possibility that the brake pedal cannot be rotated forward.

The present invention has been made in view of the above circumstances, and has as its object to surely reduce the load that a driver's foot receives from a brake pedal in the event of an automobile collision.

[0005]

According to one aspect of the present invention, there is provided a brake pedal operated by a driver at a rear end of a push rod of a brake hydraulic pressure generating means for generating a brake hydraulic pressure. In the brake device for an automobile, the axis of the push rod is vertically inclined with respect to the horizontal plane, and is disposed when an axial compression force of a predetermined value or more acts on the push rod at the time of collision of the automobile. The push rod is bent to allow the brake pedal to move forward of the vehicle body.

According to the above construction, when the driver depresses the brake pedal and an axial compression force less than a predetermined value acts on the push rod, the push rod is not bent and the movement of the brake pedal is transmitted to the brake hydraulic pressure generating means. I do.
When the brake hydraulic pressure generating means retreats due to the collision of the vehicle and an axial compressive force of a predetermined value or more acts on the push rod, a bending load is applied to the push rod which is arranged vertically and the push rod bends. And
The forward stroke of the brake pedal is allowed, and the load applied to the driver's foot is reduced.

The predetermined value is larger than an axial compression force generated when a driver applies a normal pedaling force to a brake pedal, and is an axial compression force generated when the brake hydraulic pressure generating means retreats due to an automobile collision. It is a smaller value.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 5 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a front portion of a vehicle compartment provided with a negative pressure booster.
2 is an enlarged sectional view of the negative pressure booster, FIG. 3 is an enlarged view of a main part of FIG. 2, FIG. 4 is an explanatory diagram of an operation at the time of a collision, and FIG. 5 is a graph showing a load applied to a brake pedal.

As shown in FIG. 1, a dashboard upper 25 extending substantially horizontally and a dashboard lower 26 extending substantially downward from the dashboard upper 25 are provided at the front of the cabin of the automobile. The dashboard lower 26 supports a negative pressure booster B integrally provided with a master cylinder M. The master cylinder M and the negative pressure booster B constitute a brake hydraulic pressure generating means of the present invention.

An upper end of the brake pedal 12 is rotatably supported via a pin 28 on a pedal bracket 27 connecting the dashboard upper 25 and the dashboard lower 26. A negative pressure booster B is provided at an intermediate portion of the brake pedal 12. The rear end of the push rod 10 extending rearward from the rear end is supported via a pin 29. The axis L of the push rod 10 is arranged so as to be inclined such that the rear side is lower with respect to the horizontal plane P.

As shown in FIG. 2, the booster shell 1 of the negative pressure booster B has a pair of front and rear shell halves 1a and 1b whose opposing ends are connected to each other. The booster piston 3 is housed so as to be able to reciprocate back and forth. The outer periphery of the diaphragm 2 is fixed to the joint between the two shell halves 1a, 1b, and the inner periphery of the diaphragm 2 is fixed to the outer periphery of the front part of the piston boss 4. The booster piston 1 and the diaphragm 2 partition the inside of the booster shell 1 into a front negative pressure chamber A facing the front surface of the booster piston 3 and a rear working chamber B facing the rear surface of the diaphragm 2. A rear extension cylinder 5 extending rearward is formed integrally with a central portion of the rear wall of the shell half 1b,
At the rear end of the rear extension cylinder 5, an air inlet 6 is formed. The negative pressure chamber A is always in communication with an intake manifold (not shown) of the internal combustion engine that is a negative pressure source. Booster piston 3
Is urged rearward by a return spring 7 mounted between the shell half 1a.

The piston boss 4 has a cylindrical portion 4a slidably supported by a rear extension cylinder 5 via a sealing member 9, and purifies air introduced from an air inlet 6 at a rear portion inside the cylindrical portion 4a. At the same time, a filter 11 that can be deformed so as not to hinder the operation of the input rod 10 is mounted. A valve piston 13 is connected to the tip of the input rod 10 connected to the brake pedal 12, and the valve piston 13 is slidably supported at the center of the piston boss 4. A control valve 14 that is operated to switch according to the relative movement of the valve piston 13 with respect to the piston boss 4 due to the advance / retreat operation of the input rod 10 is provided inside the cylindrical portion 4 a of the piston boss 4.

Next, the structure of the control valve 14 will be described with reference to FIG. The control valve 14 has a valve body 15 made of rubber.
An annular first valve seat 16 ₁ formed inside the piston boss 4 to enable the valve body 15 to be seated;
It is formed on the third rear end annularly and a ₂ second valve seat 16 which enables the seating of the first valve seat 16 the valve body 15 while being surrounded by _1. The valve element 15 is formed in a cylindrical shape, and the rear end portion of the valve element holding cylinder 1 fitted on the inner periphery of the cylindrical portion 4 a of the piston boss 4.
8 and the front ends are the first valve seat 16 ₁ and the second valve seat 1
Is formed in a thick as possible the seating of the 6 _2,
The first and second valve springs 19 provided between the first and second input rods 10 are provided.
It is urged toward the valve seats 16 ₁ and 16 ₂ . The input rod 10 is urged in a backward direction by a return spring 8 provided between the input rod 10 and the valve body holding cylinder 18.

A first valve seat 16 ₁ The outer piston boss 4
Is communicated with the negative pressure chamber A via a through hole 20 provided in the first through hole.
The first, middle portion of the second valve seat 16 _1, 16 ₂ is communicated to the working chamber B through another hole 21 provided in the piston boss 4, the inside of the second valve seat 16 ₂ valve body 15 and communicates with the air introduction port 6 through the interior.

In the control valve 14, when the valve body 15 is seated on the first and second valve seats 16 ₁ and 16 ₂ ,
The communication between the negative pressure chamber A and the working chamber B is cut off, and the communication between the two chambers A, B and the air inlet 6 is also cut off. That is, the control valve 14 is in the switching neutral state. The being switched upright state from the valve piston 13 is advanced relative to the piston boss 4 the second valve seat 16 ₂ is separated from the valve body 15, through holes 21
The working chamber B communicates with the atmosphere introduction port 6 via the. When the valve piston 13 moves backward with respect to the piston boss 4,
The valve body 15 away from the first valve seat 16 ₁ via the holes 20 and 21 and the negative pressure chamber A and the working chamber B communicates.

The piston boss 4 has an output rod 2 extending forward.
The output rod 22 is connected to the master cylinder M. A rod 23 penetrating the booster shell 1 back and forth
As a result, the negative pressure booster B is fixed to the dashboard lower 26 that partitions the front of the vehicle compartment, and the master cylinder M is fastened to the booster shell 1 together. The outer periphery of the rod 23 is covered by a boot 2a provided integrally with the diaphragm 2 so that the negative pressure chamber A and the working chamber B do not communicate with each other.

Next, the operation of the above embodiment will be described.

A brake pedal 12 is depressed to brake the vehicle, and the input rod 10 and the valve piston 1 connected thereto are applied.
3 and is advanced to, initially, since the booster piston 3 is immobile, the second valve seat 16 _second valve piston 13 away from the valve body 15 of control valve 14. As a result, the working chamber B communicates with the atmosphere introduction port 6 through the through hole 21 and becomes atmospheric pressure,
The booster piston 3 moves forward due to a large differential pressure generated between the negative pressure chamber A and the working chamber B, and the master cylinder M can be operated via the output rod 22. Brake pedal 1
When the pedaling force is released, the input rod 10 first retreats together with the valve piston 13 by the elastic force of the return spring 8, and the second valve seat 1
6 ₂ is seated on the valve body 15 and the first valve seat 16 ₁
From the valve body 15. As a result, the negative pressure chamber A and the working chamber B communicate with each other through the through hole 20 and the pressure difference disappears or decreases, so that the booster piston 3 retreats by the resilient force of the return spring 7 and the master cylinder M operates. Cancel.

The driver operates the brake pedal 1
When a treading force is applied to the push rod 2, an axial compressive force acts on the push rod 10, but the push rod 10 has such a strength that it is not bent by the treading force. However, as shown in FIG.
6 and the pedal bracket 27 are deformed, the master cylinder M is retracted to the cabin side together with the dashboard lower 26, and when the driver puts his foot on the brake pedal 12, the push rod 10 has an axis larger than the normal pedaling force. Directional compression force acts. At this time, the negative pressure booster B retreats in a substantially horizontal direction along the horizontal plane P, whereas the axis L of the push rod 10 is vertically inclined.
Push rod 10 projecting backward from negative pressure booster B
, A bending load acts on the push rod 10 to bend downward. As a result, the brake pedal 12 rotates forward, and the brake pedal 12
Is prevented from being pushed up to the cabin side, and the load applied to the driver's foot is reduced.

The dashed line in FIG. 5 shows how the load received by the driver's foot changes with respect to the stroke of the brake pedal 12 when a high-strength non-flexible push rod 10 is used. . In this case, it can be seen that the load rises sharply when the pedal stroke reaches the limit position. On the other hand, the solid line in FIG. 5 shows a change in the load in the present embodiment. When the load increases to the point a, the push rod 10 bends, so that a further increase in the load can be avoided.

Although the embodiments of the present invention have been described in detail, the present invention can be variously modified without departing from the gist thereof.

For example, in the embodiment, the present invention is applied to the push rod 10 of the negative pressure booster M.
The present invention can be applied to a push rod of a master cylinder in a brake device having no. If a fragile portion is formed in advance on a part of the push rod 10, the push rod 10 can be bent more reliably at the time of collision.

[0024]

As described above, according to the first aspect of the present invention, the axis of the push rod is disposed so as to be vertically inclined with respect to the horizontal plane, and the push rod has a predetermined value or more when the vehicle collides. When the axial compression force is applied, the push rod is bent to allow the brake pedal to move forward of the vehicle body, so that the forward stroke of the brake pedal is allowed to reduce the load applied to the driver's foot. it can.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a front part of a passenger compartment having a negative pressure booster.

FIG. 2 is an enlarged sectional view of a negative pressure booster.

FIG. 3 is an enlarged view of a main part of FIG. 2;

FIG. 4 is an explanatory view of an operation at the time of a collision.

FIG. 5 is a graph showing a load applied to a brake pedal.

[Explanation of symbols]

 Reference Signs List 10 push rod 12 brake pedal B negative pressure booster (brake hydraulic pressure generating means) L axis M master cylinder (brake hydraulic pressure generating means) P horizontal surface

Claims (1)

[Claims] 1. A brake device for an automobile, comprising a brake pedal (12) operated by a driver connected to the rear end of a push rod (10) of a brake oil pressure generating means (B, M) for generating a brake oil pressure. The axis (L) of the push rod (10) is disposed so as to be vertically inclined with respect to the horizontal plane (P), and when an axial compression force equal to or more than a predetermined value acts on the push rod (10) at the time of collision of the vehicle. A brake device for an automobile, wherein the push rod (10) is bent to allow the brake pedal (12) to move forward of the vehicle body.