JPS629470B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid pressure brake device for a vehicle.

Conventionally, in the type of brake system that operated remotely using fluid pressure, an auxiliary emergency brake system was built into the brake system in case the piping system that sent the fluid pressure was damaged. There is a format that is set up.

In these conventional types, when the brake piping system caused by the main fluid pressure is damaged, the energy stored in the spring acts on the brake drum due to the fluid pressure being reduced. There are two types of brake systems: systems in which a single hydraulic actuator that operates the brake device is operated by main fluid pressure, and brake systems that have other fluid pressures that operate the hydraulic actuator in an emergency manner. There is a method that has a built-in system.

However, in the above-mentioned systems, the former method has the disadvantage that sudden braking is instantaneously applied in an emergency, regardless of the driver's will, and the latter method has the disadvantage that the main fluid The pipelines that select and communicate the pressure system and the emergency fluid pressure system communicate with a single fluid pressure actuator that acts in common, so if the selected pipeline system is damaged. In this case, the brake device will not work.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluid pressure brake system that has an internal emergency brake system and that has improved the above-mentioned problems.

The present invention will be explained based on examples.

FIG. 1 shows a system diagram of a hydraulic brake system for special vehicles as an embodiment of the present invention. In FIG. 1, a power unit 20 and a normal brake master cylinder 30 are shown. 3f, 3g, 5h and 2
5a is a hydraulic pipe, 5i is a pressure oil discharge pipe, 10 is a control valve, 1 is a brake pedal, 25 is a hydraulic power source, 25b is a switching valve, 26 is an accumulator, 26a is a check valve, 27 is the reservoir.

In the power unit 20, a side plate 22 is fastened to a housing 21 with a plurality of bolts, and a piston 23 is fitted into a cylinder 21a cut into the housing 21 to enable sliding movement in the axial direction. However, the piston 30b fitted into the cylinder 30a of the brake master cylinder 30 is in contact with a rod 23b fixed to the piston 23, and the spring 23a applies a force to the piston 23 to the right. .

Cylinder 23c cut into the inner circumference of piston 23
A piston 24 is fitted into the piston 24 so as to be able to slide in the axial direction, and a spring 24c applies a force to the piston 24 to the left.

The discharge pipe 5i communicates with the reservoir 27 through the borehole 22a, the chamber 21h and the borehole 21e, the hydraulic pipeline 3g communicates with the pressure chamber 24b through the connection hole 21b and the borehole 24a, and the hydraulic pipeline 5h communicates with the reservoir 27 through the borehole 21e.
d, and the hydraulic pipe line 5h communicates with the pressure chamber 21g through the perforations 21d and 21c, and the hydraulic pipe line 25.
It communicates with a hydraulic power source 25 via a and a switching valve 25b.

FIG. 2 shows a side sectional view of the control valve 10 in FIG. 1, in which a rear housing 3 is screwed onto the front housing 2, and a side plate 3d is screwed onto the rear housing 3. A large-diameter piston 5b and a small-diameter piston 5a of the piston 5 are fitted into cylinders 2e and 2d cut into the front housing 2 so as to be able to slide in the axial direction, respectively. A valve 6 is fitted into the cut cylinder 5g so as to be able to slide in the axial direction, and the rod 1a, which is interlocked with the brake pedal 1, comes into contact with the valve 6, and the springs 5g and 6h
, each of which applies a biasing force to the piston 5 and the valve 6, respectively.

A rod 7 having a bore hole 7b is fitted into the cylinder 3a cut into the rear housing 3 so as to be able to slide in the axial direction, and the spring 7a applies an urging force to the rod 7 toward the piston 5 side. There is.

A valve 4 is biased by the biasing force of a spring 4a to a valve seat 3b cut into a port 3h communicating with the perforation 7b.

By the large diameter piston 5b and cylinder 2e,
A chamber 2f and a pressure chamber 2g are provided on both sides of the piston 5b.
are formed respectively.

A groove 5c is cut on the circumference of the piston 5, and a groove 5d,
5e and 5f are perforations, respectively, grooves 6b, 6d and 6f are cut on the circumference of the valve 6, and grooves 6b, 6d and 6f are respectively perforated by the perforation 6.
They are integrally communicated via a, 6c, 6e and 6g.

The hydraulic conduit 5h communicates with the groove 5c via the perforation 2b, the discharge conduit 5i communicates with the chamber 2f via the perforation 2c, and the hydraulic conduit 3g communicates with the port 3h, enclosing the spring 4a and the valve 4. The chamber 3c to be installed is the perforation 3
It communicates with the hydraulic pipe line 3f via e.

Note that 2a is a boot, and 6i is a check valve.

In the above configuration, its operation is explained as follows.
During brake operation under normal conditions, no hydraulic pressure is generated in the hydraulic line 3g, so the switching valve 2
5b is in an open state as shown in FIG. 1, and in this state, as the brake pedal 1 is depressed, the spring constant of the spring 6h becomes smaller than the spring constant of the spring 5g. , the valve 6 moves toward the rear housing 3 relative to the piston 5. As a result, groove 6
f will close the perforation 5f, and therefore, the pressure oil being fed from the hydraulic source 25 will be transferred to the switching valve 25b, the hydraulic conduit 25a, the perforations 21c and 21.
d, pressure chamber 21g, hydraulic pipe 5h, perforation 2b, groove 5c, perforation 5d, groove 6b, perforation 6c, 6a, 6
e, the pressure in the pressure chamber 2g is increased through the groove 6d and the perforation 5e, and this pressure causes the large-diameter piston 5b of the piston 5 to move against the urging force of the spring 5g and press the rear housing 3. 21g of the pressure chamber at the same time.
The increased pressure presses the piston 23 toward the brake master cylinder 30, and as a result, the piston 23 pushes against the piston 3 via the rod 23b.
0b to apply a brake to a brake drum (not shown).

However, in this action, as the piston 5 moves toward the rear housing 3, the groove 6
Since f will open the perforation 5f again,
The system of pressure chambers 2g and 21g is in a state where it is easily opened to the reservoir 27 via the chamber 2f, the perforation 2c, the discharge pipe 5i, the perforation 22a, the chamber 21h and the perforation 21e, and there is no attempt to reduce the pressure therein. When the piston 5 tries to return to the rod 1a side due to the pressure drop due to the urging force of the spring 5g, the perforation 5f is closed again, and the pressure in the pressure chambers 2g and 21g is increased again. try to make it happen

As a result, the pressures generated in the pressure chambers 2g and 21g have the effect of becoming an operating pressure corresponding to the amount of movement of the valve 6.

Note that when the brake pedal 1 is not depressed, the perforation 5f is fully open, so the pressure chambers 2g and 21g are each open to the reservoir 27.

In addition, in the above state, the pressure chamber 24b
are perforation 24a, hydraulic pipe line 3g, port 3h, perforation 7b, chamber 2f, perforation 2c, discharge pipe 5i, perforation 2
Since the pressure chamber 24b is open to the reservoir 27 through the chamber 2a, the chamber 21h, and the perforation 21e, no pressure is generated in the pressure chamber 24b.

In the above normal state, the front housing 2, the piston 5, and the valve 6 form one control valve, and the cylinder 21a and the piston 23 form one fluid actuator. In an emergency when any part of the system consisting of one fluid actuator is damaged and pressure cannot be generated in the pressure chamber 21g, the brake pedal 1
The piston 5 closes the borehole 7b in the rod 7 by depressing it more forcefully than the normal depressing described above.

As a result, the pressure chamber 24, which has been in communication until now,
b and the reservoir 27 are in a new closed state, and from this state the brake pedal 1
As you step down, the movement of piston 5 causes
The rod 7 is in a state of pushing up the valve 4, and the chamber 3
c and port 3h communicate with each other, and at this time, the pressure oil stored in the accumulator 26 is transferred to the hydraulic pipe 3.
f, perforation 3e, chamber 3c, port 3h, hydraulic pipe line 3
g and the perforation 24a to the pressure chamber 24b.

As a result, the shoulder 24d of the piston 24 remains in contact with the housing 21, and on the other hand, the piston 23 presses the piston 30b via the rod 23b as a reaction force from the pressing of the piston 24. Since the valve 4 is pushed up according to the amount of depression of the brake pedal 1,
Depending on the opening amount of the valve 4, the amount by which the piston 23 is pressed is determined.

Furthermore, when the brake pedal 1 is released from the above state, the piston 5 is pushed back by the force of the spring 5g, so the valve 4
is again seated on the valve seat 3b, and the hole 7b in the rod 7 is opened from the piston 5, and the port 3h is opened.
are the perforation 7b, the chamber 2f, the perforation 2c and the discharge pipe 5i.
The fluid is communicated with the reservoir 27 via the above-described method, and the hydraulic pressure in the pressure chamber 24b also disappears.

Furthermore, when hydraulic pressure is generated in the hydraulic pipe line 3g, the switching valve 25b is set to a closed state by the hydraulic pressure, so that the oil discharged from the hydraulic source 25 is removed from damage in the hydraulic pipe line 25a. The discharge hydraulic pressure is then replenished into the accumulator 26 via the check valve 26a.

Note that in the above-mentioned normal state in which no hydraulic pressure is generated in the hydraulic line 3g, the switching valve 25b is always open, but as described in detail above, when the brake pedal 1 is depressed, Since the hydraulic line 25a is under pressure, the oil discharged from the hydraulic source 25 is also replenished into the accumulator 26 via the check valve 26a at this time.

In addition, in the above-mentioned embodiment, the explanation was given regarding the operation using hydraulic pressure, but this may also be fluid pressure control using pneumatic pressure.

As described above, the fluid pressure brake device according to the present invention includes one control valve, one fluid actuator, and the other control valve and the other fluid actuator that are independent from each other as a brake master system. - By having a configuration that acts on the cylinder 30, the brake master cylinder 3
Even if any part of the brake master cylinder 30 is damaged, the brake master cylinder 30 will function normally.

In addition, the other control valve used in an emergency is not one that applies only the maximum constant braking force in an emergency situation, as with conventional spring brakes; The brake force can be manipulated, and even if one control valve system is damaged, it is possible to continue driving while repeatedly applying the brakes in the same way as a normal brake. This is the result.

Furthermore, the hydraulic pressure source 25 as one pressure source and the accumulator 26 as the other pressure source may be respective pressure sources consisting of independent hydraulic pumps. In this case, there is no need to connect one pressure source to the other pressure source via the check valve 26a, and there is no need for the switching valve 25b.

However, as in the second invention in the claims, when the check valve 26a shown in FIG. ) can be made into a single,
Moreover, by providing the switching valve 25b in the hydraulic pipe 25a that operates by detecting the pressure in the hydraulic pipe 3g, pressure oil is always replenished into the accumulator 26 when the brake pedal 1 is depressed. On the other hand, when the brake pedal is not depressed, no hydraulic pressure is generated in the discharge pipe of the single hydraulic pump, so there is no unnecessary power usage. It has become a thing.

[Brief explanation of the drawing]

FIG. 1 shows a system diagram of the hydraulic brake device according to the present invention. In FIG. 1, the power unit 20 is shown in a side sectional view, and FIG. 2 shows the control valve 10 in FIG.
1 shows a side sectional view of. The symbols used in the examples are as follows.
1: Brake pedal, 1a: Rod. 2: Front housing, 2a: Boot, 2b and 2c: Perforation, 2d and 2e: Cylinder, 2f: Chamber, 2
g: Pressure chamber. 3: rear housing, 3a: cylinder, 3b: valve seat, 3c: chamber, 3d: side plate, 3f and 3g: hydraulic conduit, 3h: port. 4: Valve, 4
a: Spring. 5: Piston, 5a: Small diameter piston, 5b: Large diameter piston, 5c: Groove, 5d, 5
e and 5f: perforation, 5g: spring, 5h:
Hydraulic line, 5i: Discharge line. 6: Valve, 6a, 6
c, 6e and 6g: perforation, 6b, 6d and 6
f: groove, 6h: spring. 7: Rod, 7a:
Spring, 7b: perforation. 10: Control
Valve, 20: Power unit, 21: Housing, 21a: Cylinder, 21b: Connection hole, 21
c, 21d and 21e: perforation, 21f: relief valve, 21g: pressure chamber, 21h: chamber. 22: Side plate, 22a: Perforation, 22b: Marking part. 23 and 24: Piston, 23a and 24c: Spring, 23b: Rod, 23c: Cylinder, 24
a: perforation, 24b: pressure chamber, 24d: shoulder. 25:
Hydraulic source, 25a: Hydraulic pipe line, 25b: Switching valve. 2
6: Accumulator, 26a: Check valve. 2
7: Reservoir, 30: Brake master cylinder, 30a: Cylinder, 30b: Piston.

Claims (1)

[Claims] 1. One fluid actuator and the other fluid actuator each have a brake master and a brake master.
a discharge line in one pressure source communicates with the one fluid actuator and one control valve, the one control valve is in conjunction with a brake pedal, and: a: the brake; When the brake pedal is not depressed, the discharge pipe is opened to the reservoir, and b: When the brake pedal is depressed, the discharge pipe and the reservoir are opened in response to the depression, and the discharge pipe is opened to the reservoir. The one fluid actuator is configured as described above to increase the pressure in the discharge pipe, and the one fluid actuator increases the pressure in the brake master when the pressure in the discharge pipe is released to the reservoir.
When the pressure of the cylinder is returned and b: the pressure in the discharge pipe increases,
As the pressure increases, the pressure presses the brake master cylinder. The other control valve is interposed between the other fluid actuator and the other pressure source, and the other control valve is interposed between the other fluid actuator and the other pressure source. The control valve is configured to: (a) increase the communication ratio between the other fluid actuator and the other pressure source in response to the depression when the brake pedal enters a state of depression close to the maximum; closing the communication between the fluid actuator and the reservoir to increase the pressure on the other fluid actuator; b: Conversely, when the brake pedal is in a normal depression range other than near the maximum depression,
the movement of the brake pedal is discoupled from the other control valve, opening the other fluid actuator to the reservoir; b: When the pressure from the other pressure source is being fed to the other fluid actuator, the brake master cylinder is inactivated in response to the pressure feeding. A servo device consisting of the above configuration presses down. 2 One fluid actuator and the other fluid actuator are each connected to a brake master.
in conjunction with the cylinder, a discharge line in the pressure source communicates with the one fluid actuator and one control valve, the one control valve being coupled to a brake pedal; When the brake pedal is not depressed, the discharge pipe is opened to the reservoir, and b: When the brake pedal is depressed, the discharge pipe and the reservoir are opened to each other according to the depression, and the discharge pipe is opened to the reservoir. The one fluid actuator increases the pressure in the discharge pipe, and the one fluid actuator increases the pressure in the brake master pipe when the pressure in the discharge pipe is released to the reservoir.
When the pressure of the cylinder is returned and b: the pressure in the discharge pipe increases,
As the pressure rises, the pressure presses the brake master cylinder.The other control valve is interposed between the other fluid actuator and the accumulator, and the other control valve is provided between the other fluid actuator and the accumulator. The control valve is configured such that: a: when the brake pedal is depressed close to the maximum level, the rate of communication between the other fluid actuator and the accumulator is increased in response to the depression; closing communication between the actuator and the reservoir;
increasing the pressure on the other fluid actuator; b: conversely, when the brake pedal is in a normal depression range other than near the maximum depression;
the movement of the brake pedal is discoupled from the other control valve, opening the other fluid actuator to the reservoir; b: When the pressure from the accumulator is being fed to the other fluid actuator, the brake master cylinder is actuated in response to the pressure feeding. A check valve is interposed between the pressure source and the accumulator, a switching valve is interposed in the discharge pipe, and the switching valve is configured to:a: when the other fluid actuator is open to the reservoir, communicating between the pressure source and the one control valve and the one fluid actuator; b: pressure is pumped to the other fluid actuator; A servo device having the above configuration, which closes the discharge pipe line by the pressure when the discharge pipe is released.