JP7059462B2 - Boost brake device - Google Patents

Description

The present invention relates to a booster brake device including a brake booster connected to a brake pedal.

Conventionally, a booster brake device including a brake booster connected to a brake pedal is known. The brake booster functions to amplify the input from the brake pedal. This makes it possible to push out the piston housed in the master cylinder more strongly even if the input from the brake pedal is relatively small.

Patent Document 1 discloses an example of a brake booster. The brake pedal is connected to the rear end of the input shaft located behind the brake booster. In the event of a vehicle collision, when the vehicle body receives an impact force from the outside, the brake pedal retracts toward the vehicle together with the brake booster. At this time, if the input shaft is not displaced relative to the brake pedal, the brake pedal retracts more. Therefore, the possibility that the brake pedal comes into contact with the occupant is higher, and there is a concern that the safety for the occupant may be reduced.

Japanese Unexamined Patent Publication No. 10-23840

In view of the above circumstances, it is an object of the present invention to provide a booster brake device capable of suppressing the retreat of the brake pedal in the event of a vehicle collision.

The boost brake device provided by the present invention has a pedal bracket having a first axis extending in the vehicle width direction and supported on the vehicle rear side of the partition wall member, and the first shaft extending in the vehicle width direction. A brake pedal that has a second shaft located below the shaft and is suspended and supported by the pedal bracket so that the upper end can rotate around the first shaft, and a piston housed in the master cylinder. An output shaft that operates the output shaft, a shell portion that accommodates the output shaft, a booster piston supported at the rear end of the shell portion, a plunger that is accommodated in the booster piston and is located behind the output shaft, and a plunger. The front end is supported by the plunger and the rear end has an input shaft supported by the brake pedal so as to be rotatable around the second shaft, and the shell portion is on the vehicle front side of the partition wall member. The brake booster is provided with a supported brake booster, and the brake booster is provided with a rotation allowable means for rotating the input shaft in the vehicle width direction by receiving an impact force from the outside, and the impact force is applied. When the pedal bracket comes into contact with the guide member located behind the vehicle wall member by receiving the brake bracket, the pedal bracket hangs down along the guide member and is viewed along the vehicle width direction. The axis of the second axis is more than the virtual line connecting the first virtual point located on the axis and the rearmost end of the plunger and the second virtual point located at the trailing edge and the lowest end of the booster piston. It is characterized in that it is displaced downward to the vehicle by the rotation allowing means.

According to the booster brake device provided by the present invention, it is possible to suppress the retreat of the brake pedal in the event of a vehicle collision.

Other features and advantages of the present invention will be more apparent by the detailed description given below based on the accompanying drawings.

It is a side view (the view seen from the left side in the vehicle width direction) of the booster brake device which concerns on 1st Embodiment of this invention, and shows a part of a brake booster as a cross-sectional view. It is a partially enlarged view of FIG. FIG. 3 is a partially enlarged cross-sectional view according to another embodiment of the booster brake device shown in FIG. 1. It is a side view explaining the operation effect of the booster brake device shown in FIG. 1, and a part of a brake booster is shown as a sectional view. It is a side view (the view seen from the left side in the vehicle width direction) of the booster brake device which concerns on 2nd Embodiment of this invention, and shows a part of a brake booster as a cross-sectional view.

The embodiment for carrying out the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
The boost brake device A10 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. The boost brake device A10 includes a pedal bracket 21, a brake pedal 22, and a brake booster 30. Here, FIGS. 1 and 4 show a part of the brake booster 30 as a cross-sectional view along the axis N of the plunger 34 (details will be described later) for convenience of understanding. The cross-sectional view shows only the main part of the brake booster 30. The cross-sectional position of FIG. 3 is the same as the cross-sectional position of FIG.

Here, for convenience of explanation, up shown in these figures indicates the vehicle upward direction, dwn indicates the vehicle downward direction, fr indicates the vehicle front direction, and rr indicates the vehicle rear direction. Further, in the following description, when the upper and lower parts are used without special mention, it means the upper and lower parts of the vehicle of the booster brake device A10, and when the front and back parts are used without special mention, it means the front and back of the vehicle of the booster brake device A10. The vehicle width direction refers to the vehicle left-right direction.

As shown in FIG. 1, the pedal bracket 21 is supported on the vehicle rear side of the partition wall member 11. In the booster brake device A10, the partition wall member 11 is a dash panel that separates the engine room and the vehicle interior in the front-rear direction of the vehicle. The pedal bracket 21 has a first shaft 211 and a base plate 212. The first shaft 211 extends in the vehicle width direction and is fixed to the main body of the pedal bracket 21. The base plate 212 is located at the front end of the pedal bracket 21. The base plate 212 is in contact with the surface of the partition member 11 facing the vehicle rear. The base plate 212 is used to support the pedal bracket 21 on the partition member 11.

As shown in FIG. 1, the brake pedal 22 is suspended and supported by the pedal bracket 21. The upper end of the brake pedal 22 is configured to be rotatable around the first axis 211 of the pedal bracket 21. The brake pedal 22 has a second shaft 221 and a pedal portion 222. The second shaft 221 is located below the vehicle with the first shaft 211. The second shaft 221 extends in the vehicle width direction and penetrates the brake pedal 22. The pedal portion 222 is located at the lower end of the brake pedal 22. When the occupant steps on the pedal portion 222, the brake pedal 22 rotates around the first shaft 211.

As shown in FIG. 1, the brake booster 30 is supported on the vehicle front side of the partition wall member 11. The brake booster 30 has an output shaft 31, a shell portion 32, a booster piston 33, a plunger 34, and an input shaft 35.

As shown in FIG. 1, the output shaft 31 operates a piston (not shown) housed in the master cylinder 40. The master cylinder 40 is filled with brake fluid. When the output shaft 31 operates the piston, the brake fluid is supplied to the wheel cylinders of each wheel.

As shown in FIG. 1, the shell portion 32 is a hollow member that accommodates the output shaft 31. In the example shown by the boost brake device A10, the shell portion 32 has a configuration in which two members are butted against each other in the front-rear direction of the vehicle. The shell portion 32 is located in the engine room. A plurality of stud bolts 321 are provided on the shell portion 32. The plurality of stud bolts 321 project from the rear end of the shell portion 32 toward the rear of the vehicle. The partition wall member 11 is provided with a plurality of first holes (not shown) that penetrate in the front-rear direction of the vehicle and correspond to the arrangement of the plurality of stud bolts 321. The plurality of stud bolts 321 are individually inserted into the plurality of first holes from the vehicle front side of the partition wall member 11. Further, the base plate 212 of the pedal bracket 21 is provided with a plurality of second holes (not shown) that penetrate in the front-rear direction of the vehicle and correspond to the arrangement of the plurality of first holes. As a result, the plurality of stud bolts 321 are individually inserted into the plurality of second holes in addition to the plurality of first holes. In this state, nuts are attached to each of the plurality of stud bolts 321 and the partition wall member 11 and the base plate 212 are tightened with the nuts, so that the shell portion 32 is supported on the vehicle front side of the partition wall member 11. At the same time, the pedal bracket 21 is supported on the vehicle rear side of the partition member 11.

As shown in FIG. 1, the booster piston 33 is supported by the rear end of the shell portion 32. The booster piston 33 has a cylindrical shape that penetrates the partition wall member 11 and the base plate 212 of the pedal bracket 21 from the rear end of the shell portion 32 and projects toward the rear of the vehicle. Therefore, a part of the booster piston 33 is located in the vehicle interior (driver's seat). The booster piston 33 is made of synthetic resin. As shown in FIG. 2, the booster piston 33 has an inner peripheral surface 331 and a fragile portion 332. The inner peripheral surface 331 is located inside the booster piston 33 and is along the circumferential direction of the booster piston 33 (the direction around the axial direction of the input shaft 35). The fragile portion 332 is recessed from the inner peripheral surface 331 in the radial direction of the booster piston 33 (the direction orthogonal to the axial direction of the input shaft 35). The fragile portion 332 is located behind the vehicle with respect to the plunger 34 and is connected to the trailing edge of the booster piston 33. In the embodiment shown in FIG. 2, the fragile portion 332 is a portion of the booster piston 33 that is relatively thin. The portion is formed over the entire circumferential direction of the booster piston 33.

FIG. 3 shows another embodiment of the fragile portion 332 of the booster piston 33. The fragile portion 332 is a plurality of grooves extending in the axial direction of the input shaft 35. The plurality of grooves are formed below the vehicle with the input shaft 35.

As shown in FIG. 1, the plunger 34 is housed in the inner member of the booster piston 33. The plunger 34 is located behind the vehicle with respect to the output shaft 31. The plunger 34 moves along the axis N shown in FIG. As shown in FIG. 2, the plunger 34 has a first support portion 341. The first support portion 341 is located at the rear end of the plunger 34. The first support portion 341 is recessed from the rear end of the plunger 34 toward the front of the vehicle.

As shown in FIG. 2, the front end of the input shaft 35 is supported by the first support portion 341 of the plunger 34. The front end of the input shaft 35 is spherical. The front end of the input shaft 35 is fitted and tightened in the first support portion 341. However, when an impact force from the outside is received at the time of a vehicle collision, a rotational displacement occurs at the front end of the input shaft 35 with respect to the first support portion 341. The input shaft 35 has a second support portion 351. The second support portion 351 is located at the rear end of the input shaft 35. The second support portion 351 is a clevis. The second support portion 351 sandwiches the periphery of the second shaft 221 of the brake pedal 22 from both sides in the vehicle width direction. The second shaft 221 penetrates the second support portion 351 in the vehicle width direction. The second support portion 351 is supported by the brake pedal 22 so as to be rotatable around the second shaft 221.

As shown in FIGS. 2 and 3, the virtual line V is a straight line connecting the first virtual point 30A and the second virtual point 30B when viewed along the vehicle width direction. The first virtual point 30A is located on the axis N of the plunger 34 and at the rearmost end when viewed along the vehicle width direction. The second virtual point 30B is located at the trailing edge and the lowest position of the booster piston 33 when viewed along the vehicle width direction. In a normal state, the axis C of the second axis 221 of the brake pedal 22 is located above the virtual line V when viewed along the vehicle width direction.

Next, the outline of the mechanism of the boost brake device A10 will be described.

The inside of the shell portion 32 of the brake booster 30 is divided into two rooms (not shown) in the front-rear direction of the vehicle by a diaphragm (not shown) which is an elastic body. For convenience of explanation, the room located in front of the vehicle is referred to as a first room, and the room located behind the vehicle is referred to as a second room. A suction port (not shown) is provided at the front end of the shell portion 32, and the first chamber leads to the suction port. The suction port is connected to the intake manifold of the engine. As a result, the pressure of the air in the first chamber becomes a negative pressure with respect to the atmospheric pressure while the engine is being driven. On the other hand, the inside of the booster piston 33 of the brake booster 30 is connected to each of the first chamber and the second chamber. Further, inside the booster piston 33, a connecting passage (not shown) for circulating the air in the first chamber and the air in the second chamber is provided. When the boost brake device A10 is not activated, the connecting passage is open. Therefore, the pressure of the air in the second chamber is equal to the pressure of the air in the first chamber. Therefore, both the pressure of the air in the first chamber and the pressure of the air in the second chamber are negative pressures with respect to the atmospheric pressure.

When the occupant steps on the pedal portion 222 of the brake pedal 22, the brake pedal 22 rotates around the first shaft 211 of the pedal bracket 21 and the input shaft 35 of the brake booster 30 is along the axis N of the output shaft 31. And push it in front of the vehicle. Then, the plunger 34 is pushed forward along the axis N by the input shaft 35, and the plunger 34 closes the connecting passage provided in the booster piston 33. As a result, the flow of air between the first chamber and the second chamber of the shell portion 32 is blocked, and the atmosphere flows into the second chamber from the rear end of the booster piston 33. That is, although the pressure of the air in the first chamber always holds a negative pressure with respect to the atmospheric pressure, the pressure of the air in the second chamber becomes the atmospheric pressure, so that the pressure of the air in the second chamber is the first. It is greater than the pressure of the air in one room. Therefore, a pressure difference of air is generated inside the shell portion 32. By using this pressure difference as power, the force of the output shaft 31 that pushes the piston of the master cylinder 40 can be amplified.

Next, the operation and effect of the boost brake device A10 will be described.

The brake booster 30 of the booster brake device A10 is provided with rotation allowing means for rotating the input shaft 35 in the vehicle width direction by receiving an impact force from the outside in the event of a vehicle collision. In the booster brake device A10, the rotation permitting means is composed of the first support portion 341 of the plunger 34 and the fragile portion 332 of the booster piston 33. As shown in FIG. 4, when the vehicle body receives an impact force from the front of the vehicle during a vehicle collision, the partition member 11 retracts to the rear of the vehicle. Therefore, the boost brake device A10 also retreats to the rear of the vehicle. Here, in the vehicle body, the guide member 12 and the support member 13 are located behind the vehicle body of the partition wall member 11. The support member 13 is a reinforcing member of the vehicle body extending in the vehicle width direction and having both ends in the vehicle width direction supported by the vehicle side member. The support member 13 suspends and supports the steering column. The guide member 12 is a bracket suspended and supported by the support member 13.

When the boost brake device A10 retracts to the rear of the vehicle, the upper end of the pedal bracket 21 comes into contact with the guide member 12, and the pedal bracket 21 hangs down along the guide member 12. At this time, the first support portion 341 of the plunger 34 constituting the rotation allowable means receives an impact force, so that the input shaft 35 can rotate around the point B shown in FIG. 4 in the vehicle width direction. .. When the input shaft 35 rotates, the input shaft 35 comes into contact with the fragile portion 332 of the booster piston 33 constituting the rotation allowable means, and the fragile portion 332 breaks. As a result, the input shaft 35 further rotates, so that, as shown in FIG. 4, the axis C of the second shaft 221 of the brake pedal 22 when viewed along the vehicle width direction is the first virtual point 30A and the second virtual point. It is displaced below the vehicle from the virtual line V connecting the point 30B. As a result, the retreat of the brake pedal 22 is suppressed by the length ΔL1. Therefore, according to the booster brake device A10, it is possible to suppress the retreat of the brake pedal 22 in the event of a vehicle collision.

[Second Embodiment]
The booster brake device A20 according to the second embodiment of the present invention will be described with reference to FIG. In FIG. 5, the same or similar elements as the boost brake device A10 described above are designated by the same reference numerals, and duplicate description will be omitted. Here, FIG. 5 shows a part of the brake booster 30 as a cross-sectional view along the axial center N of the plunger 34 for convenience of understanding. The cross-sectional view shows only the main part of the brake booster 30.

In the booster brake device A20, the configuration of the booster piston 33 and the configuration of the rotation allowing means are different from these configurations in the booster brake device A10 described above.

In the booster brake device A20, the fragile portion 332 is not formed on the booster piston 33. It is preferable that the material of the booster piston 33 has a higher mechanical strength against impact than the material of the booster piston 33 of the booster brake device A10.

Next, the operation and effect of the boost brake device A20 will be described.

The brake booster 30 of the booster brake device A20 is provided with rotation allowing means for rotating the input shaft 35 in the vehicle width direction by receiving an impact force from the outside in the event of a vehicle collision. In the booster brake device A20, the rotation allowable means is composed of the first support portion 341 of the plunger 34 and the booster piston 33.

As shown in FIG. 5, when the vehicle body receives an impact force from the front of the vehicle during a vehicle collision, the boost brake device A20 retracts to the rear of the vehicle together with the partition member 11. As a result, the upper end of the pedal bracket 21 comes into contact with the guide member 12, and the pedal bracket 21 hangs down along the guide member 12. At this time, the first support portion 341 of the plunger 34 constituting the rotation allowable means receives an impact force, so that the input shaft 35 has the point B shown in FIG. 4 as the rotation center as in the case of the boost brake device A10. It rotates around the width of the vehicle. When the rotation progresses and the input shaft 35 comes into contact with a point D (see FIG. 5) on the inner peripheral edge located at the rear end of the booster piston 33, the point D is used as a fulcrum and the axis of the second shaft 221 of the brake pedal 22. The front end of the input shaft 35 loosens the tightening of the first support portion 341 by the principle of leverage with C as the fulcrum. As a result, the front end of the input shaft 35 falls off from the first support portion 341 and the input shaft 35 further rotates. Therefore, as shown in FIG. 5, the axis C of the second shaft 221 is viewed along the vehicle width direction. Is displaced below the vehicle from the virtual line V connecting the first virtual point 30A and the second virtual point 30B. As a result, the retreat of the brake pedal 22 is suppressed by the length ΔL2. Therefore, the booster brake device A20 can also suppress the retreat of the brake pedal 22 in the event of a vehicle collision.

The present invention is not limited to the above-described embodiment. The specific configuration of each part of the present invention can be freely redesigned.

A10, A20: Boost brake device 11: Bulk partition member 12: Guide member 13: Support member 21: Pedal bracket 211: 1st axis 212: Base plate 22: Brake pedal 221: 2nd axis 222: Pedal part 30: Brake booster 30A : 1st virtual point 30B: 2nd virtual point 31: Output shaft 321: Stud bolt 33: Booster piston 331: Inner peripheral surface 332: Vulnerable part 34: Plunger 341: 1st support part 35: Input shaft 351: 2nd support Part 40: Master cylinder N, C: Axis V: Virtual line

Claims (1)

A pedal bracket that has a first axis extending in the vehicle width direction and is supported on the vehicle rear side of the partition member,
It has a second axis that extends in the vehicle width direction and is located below the first axis, and is suspended and supported by the pedal bracket so that the upper end can rotate around the first axis. Brake pedal and
An output shaft that operates a piston housed in a master cylinder, a shell portion that houses the output shaft, a booster piston supported at the rear end of the shell part, and a vehicle that is housed in the booster piston and is more than the output shaft. The plunger located at the rear and the front end are supported by the plunger, and the rear end has an input shaft supported by the brake pedal so as to be rotatable around the second shaft, and the shell portion is said. Equipped with a brake booster supported on the front side of the vehicle of the partition member,
The brake booster is provided with a rotation permitting means for rotating the input shaft in the vehicle width direction by receiving an impact force from the outside.
The rotation permitting means is composed of the booster piston and the plunger.
When the pedal bracket comes into contact with the guide member located behind the vehicle wall member by receiving the impact force, the pedal bracket hangs down along the guide member and the input shaft is the booster piston . By contacting the inner peripheral edge located at the rear end and the front end of the input shaft falling off from the plunger.
Than the virtual line connecting the first virtual point located on the axis and the rearmost end of the plunger and the second virtual point located at the trailing edge and the lowest end of the booster piston when viewed in the vehicle width direction. , The boosting brake device in which the axis of the second axis is displaced downward by the rotation permitting means.

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