JPH0611259Y2 - Front brake control system for automobiles - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a control device for a front brake of an automobile,
More specifically, the present invention relates to a front brake control device for an automobile, in which the braking force of the front brake system can be artificially weakened according to the condition of the road surface.

<Prior Art> As a conventional front brake control device for an automobile of this type, as shown in FIG. 2, opening / closing manually operated to an air outlet 1a of a front brake system provided in a dual type brake valve 1 The inlet 2a of the valve 2 and the inlet 3a of the limiting quick release valve 3 are connected, the outlet 2d of the on-off valve 2 is connected to the control port 3b of the limiting quick release valve 3, and the limiting quick release valve is connected. There is one in which the outlet 3c of 3 is connected to a booster or a brake chamber (not shown). 1b
Is the outlet of the rear brake system, 3c is the exhaust port of the limiting quick release valve 3, 4a is the front tank, and 4b.
Is a rear tank (see JP-A-60-56661).

In such a front brake control device, the on-off valve 2
When the lever 2c is closed at the position shown in the figure, air is supplied only to the control port 3a of the limiting quick release valve 3 to output depressurized air to the booster or brake chamber. If it is tilted to the left and the on-off valve 2 is opened, air is also supplied to the control port 3b of the limiting quick release valve 3 and the brake valve 1
In order to directly supply the air output from the booster or the brake chamber as it is, the braking force of the front brake can be used separately between the normal state and the state in which the braking force of the front brake is limited only by switching the lever 2c to open and close the on-off valve 2. Therefore, the lockability of the front wheel, which tends to occur on a slippery road surface or the like, can be reduced and the steerability can be secured.

<Problems to be solved by the invention> By the way, in the limiting quick release valve 3 which performs the depressurization action as described above, the pressure of the air supplied from the inlet 3a is applied to the small diameter end face of the deformed piston. It is impossible to reduce the sliding resistance to zero. Therefore, as long as the limiting quick release valve 3 for reducing the pressure by such a balanced action of the odd-shaped piston is used, even when the vehicle is normally traveling, air is applied from the control port 3b to the stepped surface of the odd-shaped piston. There is a practically non-negligible pressure difference between the pressure of the air supplied to 3a (the pressure of the air output from the brake valve 1) and the pressure of the air output from the outlet 3c of the limiting quick release valve 3. Therefore, there is a problem that the braking force of the front brake system during braking during normal traveling is reduced.

The present invention has been made in view of such a situation,
An object of the present invention is to provide a front brake control device capable of ensuring the steerability of a vehicle by reducing the lock of the front wheel on a slippery road surface without reducing the braking force during normal traveling.

<Means for Solving Problems> In order to achieve the above object, the present invention is provided with a dual type brake valve, a limiting quick release valve using a deformed piston, and a manually operated switching valve. There is. Further, the inlet of the switching valve is connected to the air outlet of the front brake system provided in the brake valve, and one outlet of the switching valve is connected to the inlet of the limiting quick release valve. Then, after connecting the inlet of the high-pressure priority type shuttle valve to the other outlet of the switching valve and the outlet of the limiting quick release valve, the outlet of the shuttle valve was connected to the booster or the brake chamber of the front brake system. It is characterized by that.

<Operation> With such a configuration, for example, when traveling on a slippery road surface, the air output from the brake valve can be decompressed and output by outputting the air from the switching valve through the limiting quick release valve. Further, during normal traveling, air can be output by switching the switching valve without passing through the limiting quick release valve. Therefore, during normal traveling, the air having the same pressure as the air output from the brake valve can be sent to the booster or the brake chamber of the front brake system, and the desired braking force can be obtained.

Furthermore, since the shuttle valve that outputs the air output from the switching valve and limiting quick release valve to the booster or brake chamber of the front brake system has very little damping action, it is actually supplied to the booster or brake chamber of the front brake system. The error between the air pressure and the design value can be made extremely small. Furthermore, since the shuttle valve can flow backward, there is no need to provide a relay valve or the like in the air circuit downstream from the shuttle valve to perform exhaust, and the air circuit does not become complicated.

<Embodiment> An embodiment of the present invention will be described in detail below with reference to FIG.

Brake pedal 10a operated by the driver
The brake valve 10 provided with is composed of a dual type brake valve in which the front brake system and the rear brake system are independent, and the inlet 11a of the manual switching valve 11 is connected to the air outlet 10b of the front brake system. is doing. 10c is an air outlet of the rear brake system, 12a,
Reference numeral 12b denotes a front tank and a rear tank, and at least one of control air and operation air is supplied to the front brake and the rear brake from each of these tanks 12a and 12b.

The switching valve 11 includes a lever 11b that is manually operated in the left-right direction in the figure. When the lever 11b is held at the position shown in the figure, the inlet 11a is connected to the first outlet 11c.
To the lever 11b.
Is swung to the left side in the figure, the plunger 11f provided with the valve body 11e is pushed down against the spring 11g, so that the inlet 11a is switched and connected to the second outlet 11h.

The inlet 13a of the limiting quick release valve 13 is connected to the first outlet 11c provided in the switching valve 11, and the outlet 13b of the limiting quick release valve 13 and the switching valve 11 are provided. The second outlets 11h are respectively connected to the inlets 14a and 14b of the high-pressure priority type shuttle valve 14, and the outlet 14c of the shuttle valve 14 is a control signal supply port provided in a booster (not shown) of the front brake system. Connected to.

In addition, the limiting quick release valve 13 is
A deformed piston 13d is inserted in a stepped cylinder provided in the valve body 13c so as to be vertically movable in the figure.
A hole 13e is formed vertically through the deformed piston 13d. A spherical feed valve 13f seated from above on the upper end (valve seat) of the hole 13e and an upper end (valve seat) of the exhaust port 13g provided at the bottom of the valve body 13c are opposed to each other from above with a predetermined clearance. Exhaust valve 13h and rod 13 penetrating the hole 13e
Guide fixed to the valve body 13c by connecting via i
A spring 13k is provided between 13j and the lower surface of the deformed piston 13d.
By tensioning the spring 13K, the piston 13
The feed valve 13f is seated and held by pushing up d, and the air introduced from the inlet 13a is applied to the small diameter end surface (upper surface) of the deformed piston 13d.

In the vehicle front brake control device having such a structure, when the vehicle is used for traveling on a normal road surface, the lever 11b of the switching valve 11 is rocked to the left side in the drawing to push down the plunger 11f. Inlet 11a to second outlet 11
Keep it in communication with h. Then, in this state, when the brake pedal 10a is operated to operate the brake, the air output from the air outlet 10b of the front brake system provided in the brake valve 10 passes through the switching valve 11 and the shuttle valve 14 and is illustrated. Not supplied to boosters. For this reason, the pressure of the air supplied to the booster becomes equal to the pressure of the air output from the brake valve 10 if the loss due to the line resistance is ignored, and a sufficient braking force can be obtained.

On the other hand, when the automobile is used for traveling on a slippery road surface, the lever 11b of the switching valve 11 is pivotally returned to the position shown in the figure to keep the inlet 11a in communication with the first outlet 11c. Then, in this case, the limiting quick release valve is installed in the air passage from the switching valve 11 to the booster.
Since 13 is interposed, the air depressurized by the valve 13 is supplied to the booster. Therefore, the braking force of the front brake system is weakened by the amount of pressure reduction by the limiting quick release valve 13, and the front wheel is prevented from being locked on a slippery road surface or the like.

Incidentally, the depressurizing action by the limiting quick release valve 13 as described above is caused by the pressure of the air output to the booster and the upper surface of the deformed piston 13d to which the pressure of the air output from the brake valve 10 is applied. The difference in pressure receiving area from the lower surface of the deformed piston 13d.

When air is supplied to the upper surface of the deformed piston 13d, the deformed piston 13d descends and the exhaust valve
Although 13h is seated and the exhaust port 13g is closed, when the air supply to the upper surface of the deformed piston 13d is stopped by opening the brake pedal 10a, the deformed piston 13d is moved to the position shown by the pressure difference between the upper and lower surfaces. The air from the limiting quick release valve 13 to the booster is rapidly discharged to rise and return to open the exhaust port 13g. The depressurizing action (limiting action) and quick release action are the same as those of the conventional one, and such limiting quick release valve 13 and switching valve 11
The specific structure of is not limited to the embodiment.

Further, since the outlet 11h of the switching valve 11 and the outlet 13b of the limiting quick release valve 13 are connected to the booster or the brake chamber of the front brake system via the high pressure priority type shuttle valve 14, each valve is connected.
The air output from the outlets 11h and 13b of the valves 11 and 13 is sent to the booster or the brake chamber of the front brake system without being attenuated. Therefore, the error between the air pressure actually supplied to the booster or the brake chamber of the front brake system and the design value can be made extremely small. Furthermore, since the shuttle valve 14 is capable of reverse flow, there is no need to provide a relay valve or the like in the air circuit downstream of the shuttle valve 14 to perform exhaust, and the air circuit does not become complicated.

Further, in the embodiment, the case where the booster is connected to the outlet 14c of the shuttle valve 14 has been described, but it is not always necessary to use the booster, and for example, the shuttle valve 14
A relay valve or a brake chamber may be connected to the outlet 14c of the above.

<Effects of the Invention> As described above, according to the present invention, when the vehicle is used for traveling on a normal road surface, the air of the front brake system does not pass through the limiting quick release valve like the rear brake system. On the other hand, when the vehicle is used for traveling on slippery roads, the air of the front brake system is delivered via the limiting quick release valve. It is possible to prevent the front wheel from being locked on a slippery road surface and to ensure the steerability of the vehicle without causing the braking force of the brake system to be insufficient. Furthermore, since the shuttle valve that outputs the air output from the switching valve and limiting quick release valve to the booster or brake chamber of the front brake system has very little damping action, it is actually supplied to the booster or brake chamber of the front brake system. The error between the air pressure and the design value can be made extremely small. Furthermore, since the shuttle valve can flow backward, there is no need to provide a relay valve or the like in the air circuit downstream from the shuttle valve to perform exhaust, and the air circuit does not become complicated.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a brake circuit showing an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of a brake circuit showing a conventional example. 10 …… Brake valve, 10a …… Brake pedal 10b …… Air outlet, 11 …… Switching valve 11a …… Inlet, 11c, 11h …… Outlet 13 …… Limiting quick release valve 13a …… Inlet, 13b …… Outlet 14 …… Shuttle valves, 14a, 14b …… Inlet 14c …… Outlet

Claims (1)

[Scope of utility model registration request] 1. A dual type brake valve, a limiting quick release valve using a modified piston, and a manually operated switching valve, wherein the switching is performed to an air outlet of a front brake system provided in the brake valve. The inlet of the valve is connected, one outlet of the switching valve is connected to the inlet of the limiting quick release valve, and the other outlet of the switching valve and the outlet of the limiting quick release valve are respectively high pressure priority type shuttles. A front brake control device for an automobile, characterized in that it is connected to an inlet of a valve and an outlet of the shuttle valve is connected to a booster or a brake chamber of a front brake system.