JPS6215082Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a brake device used for braking automobiles, and when a leak occurs in the foil cylinder or in the pipe that supplies pressure oil to the cylinder, all This invention relates to an improvement in a brake safety valve for preventing wheels from becoming incapable of braking and ensuring a minimum braking force.

Hydraulic brakes are widely used for braking automobiles, in which the movement of pressure oil strongly presses a brake shoe against the inner peripheral surface of a drum that rotates with the wheels or the side surface of a disc rotor. In this type of hydraulic brake, when the driver's seat presses the brake pedal, the pedal drives the piston in the master cylinder either directly or through a pneumatic booster, and the pressure oil discharged from the master cylinder is routed through piping. It is configured to supply oil to the wheel cylinder and perform braking, but if a leak occurs in any part of the foil cylinder or pressure oil piping, the oil pressure will drop throughout the entire pressure oil supply system and braking will not be possible. It is dangerous if you become unable to do it.

For this reason, the pressure oil supply system is divided into two systems in the middle, and even if a leak occurs in one system, the other system is configured so that the oil pressure does not drop, thereby minimizing the braking force even in the event of a leak. Traditionally, efforts have been made to ensure that

That is, as shown in Fig. 1, a pipe 1 for feeding pressure oil from a master cylinder is branched into two parts in the middle, and safety valves 3a and 3b are provided in the middle of each branched pipe 2a and 2b, respectively. One pipe 2
The configuration is such that even if leakage occurs in pipe a or pipe 2b, pressure oil can be supplied to the other pipe 2b or 2a.

As conventional safety valves used for this purpose, there are known safety valves having structures as shown in FIGS. 2 to 4, for example. That is, a pressure oil inlet 5 is formed in the lower part of the main body 4 of the safety valve, passages 7, 8, and 9 are provided by branching to the left and right of this inlet 5, respectively, and stop valves 6a, 6b are provided in the left and right passages 8, 8. It is something that The passage 9 communicates with the lower ends of two cylinder chambers 10 formed vertically on the left and right sides of the main body 4, respectively, as shown in FIG. Inside each cylinder chamber 10 is a rubber piston body 12 having a small through hole 11 on the side surface.
is fitted under a downward pressure from a compression spring 13. The upper end of each cylinder chamber 10 is closed by a screw cap 15 having a through hole 14 in the center, and the end of the piping 2a or 2b is connected to the through hole 14.

The operation of the conventional brake safety valve constructed as described above is as follows. That is, if there is no leakage in the pressure oil piping, etc., the stop valves 6a and 6b are kept open as shown in Figure 3, and pressure oil is sent from the piping 1 into the pressure oil inlet 5 during braking. supply.
This pressure oil passes through passages 7, 8, and 9 to the cylinder chamber 10.
However, if there is no leakage, the flow rate of the pressure oil is small, so the foil cylinder of each wheel is has through hole 1
4. A sufficient amount of pressure oil is sent through the pipes 2a and 2b to perform braking.

When a leak occurs in one of the pipes 2a and 2b, the piston body 12 in the cylinder pipe 10 on the side where the leak occurs
moves upward rapidly as pressure oil is supplied into the cylinder chamber 10 and comes into contact with the lower surface of the screw cap 15, cutting off communication between the inside of the cylinder chamber 10 and the through hole 14. In this case, the amount of movement of the piston on the leaking side and therefore the amount of oil sent will increase, so if you press the brake pedal twice and send more pressure oil from the master cylinder, it will be possible to connect the piping on the side that is not leaking. A sufficient amount of pressure oil is supplied to enable braking. At this time, you can tell that a leak has occurred in one of the pipes by the sudden increase in the amount of depression of the brake pedal, so immediately after stopping, the stop valve 6a leading to the pipe 2a or 2b on the side where the leak has occurred Or close 6b to prevent further leakage of pressure oil.

However, the conventional brake safety valve constructed and operated as described above has the following disadvantages. That is, one pipe 2a or 2b
Immediately after a leak occurs, braking can be applied by depressing the brake pedal twice, but if you do not close the stop valve 6a or 6b on the side where the leak has occurred, the brake pedal will be able to replenish the slight leak. All the pressure oil that enters the cylinder chamber 10 through the small passage hole 11 of the piston body 12 that is provided leaks out, and this replenishment oil is supplied from the master cylinder and the replenishment tank attached to it. Eventually, the oil in the master cylinder chamber and supply tank will run out and braking will no longer be possible.

In order to eliminate the above-mentioned disadvantages, the brake safety valve of the present invention is capable of reliably and repeatedly applying braking through the other pipe, even if a leak occurs in one pipe, without having to take any subsequent measures. It is configured as follows.

Hereinafter, the present invention will be explained with reference to drawings showing embodiments.

5 to 9 show an embodiment of the brake safety valve of the present invention, FIG. 5 is a plan view, and FIG.
Figure 7 is a cross-sectional view taken along line CC in Figure 6, Figure 8 is a cross-sectional view taken along line E-E in Figure 7, and Figure 9 is an enlarged view of section F in Figure 6. . Two cylinder chambers 18a and 18b parallel to each other are formed in the main body 17, which is attached to the vehicle body through the base 16. The tips of both cylinder chambers 18a and 18b (the end farthest from the base 16, the left end in FIG. 7) communicate with each other through a through hole 19, and the lower surface of the tip of one cylinder chamber 18a is provided with air from the master cylinder. A connection port 20 for connecting the pipe 1 is provided. Since each cylinder chamber 18a, 18b is built with the same left-right symmetrical structure, the following description will mainly focus on the cylinder chamber 18a.
I will explain about it. A through hole 21 (sixth
) is formed, and the through hole 21 communicates with a connecting port 22 for connecting one end of each pipe 2a, 2b via a valve body 23 (described later) for forming residual pressure.
A piston body 24 is fitted into the cylinder chamber 18a so as to be slidable in an oil-tight manner within the cylinder chamber 18a.
The tip end 24a of the piston body 24 is formed to have a small diameter, and a bottomed hole 26 is bored from the base end side. This piston body 24 is always pressed toward the tip (left end in FIG. 7) by a compression spring 25. Inside the hole 26 of the piston body 24 is a distal end 2 of a rod 28 with a packing 27 fixed to the proximal end.
8a is slidably inserted. This tip 2
The rod 8a has a larger diameter than the middle part of the rod 28, and is prevented from coming out of the central circular hole of the spring seat 29 placed over the base end of the piston body 24. The compression spring 25 is inserted between the spring seat 29 and a spring seat 30 that slidably supports the proximal end of the rod 28.
and the spring seats 30 are connected to the cylinder chambers 18a, 18.
It is brought into contact with the proximal end surface of b. 31 is a screw cap that closes the tip of the cylinder chamber 18a. Rod 28
The length is such that when the piston body 24 is moved closest to the distal end, the packing 27 fixed to the proximal end is slightly separated from the proximal end surface of the cylinder chamber 18a. A socket 33 is provided at the other end of the through hole 32, which opens at one end on the base end surface, and communicates with an oil supply tank through a pipe (not shown). Through hole 21 and piping 2 provided on the side surface of the base of cylinder chamber 18a
The valve body 23 provided between the connecting port 22 connecting the end portions of the valve body a and the connecting port 22 is configured as shown in FIG. 9 in detail. That is, a rubber ring-shaped body 36 is placed on a metal plate 35 having a small hole 34 arranged in an annular manner so as to cover the small hole 34 from the outside. Formed screw cap 39
When hydraulic pressure is applied to the inside of the valve body 23 (on the left side in FIG. 9) from the through hole 21, the inner flange 36a of the annular body 36 is formed to transfer the hydraulic pressure to the connecting port 20. When the hydraulic pressure from the through hole 21 disappears, the annular body 36 returns to its position and closes the small hole 34, and the residual pressure by the compression spring 37 is applied to the pressure oil supply system from the connection port 22 to the foil cylinder. so that the next braking can be done quickly.

Next, the operation of the brake safety valve of the present invention constructed as described above will be explained.

When using this safety valve, the piping connected to the brake master cylinder (piping 1 in Figure 1)
is connected to the connection port 20 of the main body, and each cylinder chamber 18 is connected to the connection port 20 of the main body.
Connecting ports 22, 22 opening on the sides of a, 18b are connected to the pressure oil supply system of each independent brake.

When the brake pedal is pressed to apply the brakes, pressure oil flows from the connection port 20 of the main body 4 to the cylinder chamber 1.
8a, this pressure oil circulates around the tip 24a of the piston body 24, enters the adjacent cylinder chamber 18b through the through hole 19, and pushes the piston bodies 24, 24 of each cylinder chamber toward the base end. . Due to this movement of the piston body 24, the oil filling between the spring seats 29 and 30 is pressurized and sent to the pressure oil supply system to the brake through the through hole 21 and the connection port 22, and is will be carried out.

When you stop pressing the brake pedal, each piston body 24 returns to the state shown in FIG. 7 due to the compression spring 25, and the force of the return spring of the brake shoe pushes back the piston of the foil cylinder, causing the oil to drain. Spring 3
7, the valve body 23 is pushed open and enters the cylinder chambers 18a, 18b through the through hole 21, and the oil outside the tip of the piston body returns to the master cylinder through the connection port 22. If there is a small amount of leakage in the pressure oil supply system, the rod 2 should be
The through hole 32 and the socket 33 pass between the packing 27 which is pulled away from the base end of the cylinder chamber by the
The oil from the oil supply tank flows into the spring seat 2 of the cylinder chamber.
It will be replenished between 9 and 30. Packing 27 is
Since it is pressed against the base end of the cylinder chamber due to the hydraulic pressure generated during braking, no pressure oil leaks into the through hole 32.

If one pressure oil supply system, e.g. cylinder chamber 1
If the pressure oil supply system leading to 8a is damaged and braking becomes impossible, as the brake pedal is depressed and the piston body 24 moves to the right in FIG.
The oil in the cylinder chamber 18a in front of the piston body 24 is pushed out from the through hole 21 and the connecting port 22,
No hydraulic pressure is generated because the oil is drained from the leakage point. The piston body 24 moves to the right while the rod 28 enters the hole 26, and stops when the spring seats 29 and 30 come into contact with each other. The pressure oil pushing the piston body 24 to the right does not proceed beyond the piston body 24 into the passage 21. In one cylinder chamber 18b, each part operates normally, so in order to send oil corresponding to the increased movement of the piston body 24 in the cylinder chamber 18a, press the brake pedal twice to send pressure oil from the master cylinder. The brake can be applied by the cylinder chamber 18b.

When the brake pedal is released and pressure oil no longer enters the connection port 20, the piston body 24 on the leaking side
Due to the compression spring 25, the leaked oil returns to the state shown in FIG.
a is replenished.

Next, when you step on the brake pedal, the piston body 24
The spring moves to the right until the spring seats 29 and 30 come into contact with each other, and the oil that was filled in the cylinder chamber 18a is pushed out from the through hole 21 without generating pressure, and this volume of oil is removed from the damaged part. Although it is expelled,
Thereafter, there is no leakage, and pressurized oil is sent out from the cylinder chamber 18b by pressing the pedal twice, so that the brake can be applied in a leak-free pressurized oil supply system. If the brakes are applied repeatedly in this state, the oil replenishment tank that continues to replenish oil into the cylinder chamber 18a becomes empty, and the piston body moves idly within the cylinder chamber 18a each time the brake is applied. Braking by the healthy cylinder chamber 18b is reliably performed.

As described above, the brake safety valve according to this invention completely blocks oil flow between the pressure oil supply system from the master cylinder and the pressure oil supply system leading to the foil cylinder by the piston bodies 24, 24. Since only pressure is transmitted, the pressure oil sent from the master cylinder will not leak. Therefore, even if the brake pipe etc. is damaged, the stop valve 6 can immediately stop the car like a conventional safety valve.
There is no need to close the a and 6a, and there is an advantage that even a driver who is inexperienced in car maintenance can continue driving safely.

[Brief explanation of the drawing]

Figures 1 to 4 show conventional brake safety valves,
Figure 1 is a schematic diagram showing the piping, Figure 2 is a plan view of the safety valve, Figure 3 is a sectional view taken along line AA in Figure 2, Figure 4 is a sectional view taken along line BB in Figure 2, and Figures 5 to 9. The figures show the safety valve according to this invention, Fig. 5 is a plan view, and Fig. 6 is a
Figure 7 is a cross-sectional view taken along line CC in the figure, Figure 7 is a cross-sectional view taken along line D-D in Figure 6, Figure 8 is a cross-sectional view taken along line E-E in Figure 7, and Figure 9 is an enlarged view of section F in Figure 6. be. 1, 2a, 2b: Piping, 3a, 3b: Safety valve,
4: Main body, 5: Pressure oil inlet, 6a, 6b: Stop valve,
7, 8, 9: Passage, 10: Cylinder chamber, 11: Small through hole, 12: Piston body, 13: Compression spring, 1
4: Through hole, 15: Spring lid, 16: Base, 17: Main body, 18a, 18b: Cylinder chamber, 19: Through hole,
20, 22: Connection port, 21: Through hole, 23: Valve body,
24: Piston body, 24a: Tip, 25 Compression spring, 26: Hole, 27: Packing, 28: Rod, 28a: Tip, 29, 30: Spring seat, 3
1: Screw cap, 32: Through hole, 33: Socket, 3
4: Small hole, 35: Metal plate, 36: Rubber ring,
36a: Inner flange portion, 37: Compression spring, 3
9: Screw lid.

Claims (1)

[Scope of utility model registration request] There are two cylinder chambers 18a and 18b in the main body 17.
The closed ends of both cylinder chambers are communicated through a through hole 19, and a connecting port 2 is connected to the piping from the master cylinder and communicates with the cylinder chamber.
0 is provided in the main body 17, and each cylinder chamber 18a, 18
The base end of b is connected to the connection port 22 of the pipe leading to the foil cylinder via the valve body 23 for forming residual pressure, and the piston body 24 is slidably fitted in each of the cylinder chambers 18a and 18b in an oil-tight manner. A bottomed hole 26 is bored in the piston body 24 from the base end side,
Rod 28 with packing 27 fixed to the proximal end side
The end of the rod 28 is slidably inserted into the spring seat 30, and the tip 28a of the rod 28 on the opposite side has a larger diameter and is slidably inserted into the hole 26 of the piston body 24. A spring seat 29 is provided with a center hole that does not allow the large diameter end to pass through, and the rod 28 is inserted therethrough, and the spring seat 29 is placed over the base end side of the piston body 24, and the compression spring 25 is interposed between the spring seat 30 and the spring seat 29. The length of the rod 28 is such that when the piston body 24 moves farthest from the base end of the cylinder chamber, the packing 27 will be slightly away from the base side end surface of the cylinder chamber, and the packing 27 will cover this base side end surface of the cylinder chamber. A safety valve for brakes is formed by opening a through hole 32 of the same size as the brake valve, and the through hole 32 communicates with a socket 33 connected to an oil supply tank.