JPH0371295B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake hydraulic pressure control valve device for a vehicle, which uses a pair of proportional pressure reducing valves to supply hydraulic pressure reduced from the hydraulic pressure of the front wheel brakes as the hydraulic pressure of the rear wheel brakes. The purpose of this is for a vehicle with a simple configuration that allows the anti-lock function to be achieved by simultaneously closing both proportional pressure reducing valves when the rear wheels are about to lock up, weakening the braking force on the rear wheels. An object of the present invention is to provide a brake hydraulic control valve device.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A tandem type master cylinder 1 has first and second output ports 4a and 4 which are independent of each other.
b, and when the brake pedal 2 is stepped on,
Braking oil from the oil tank 3 is supplied from each output port 4a, 4b. The oil passage 5a extending from the first output port 4a is for the left rear wheel brake via the primary brake oil pressure chamber 18a, the oil passage 6a, the first proportional pressure reducing valve Va, and the oil passage 7a. It is connected to the wheel cylinder hydraulic chamber 10 ₂ of the wheel cylinder Br ₂ , and the secondary brake hydraulic chamber 19a of the first brake hydraulic pressure adjusting means Ca is connected to the wheel cylinder hydraulic chamber 9 of the right front wheel brake wheel cylinder Bf ₁ via an oil passage 8a. Connected to ₁ . On the other hand, the oil passage 5b extending from the second output port 4b includes the primary brake oil pressure chamber 18b of the second brake oil pressure adjustment means Cb, the oil passage 6b, and the second proportional pressure reducing valve Vb.
It is connected to the wheel cylinder hydraulic chamber ₁₀₁ of the right rear wheel brake wheel cylinder _Br1 through the oil passage 7b, and the secondary brake oil pressure chamber 19b of the second brake oil pressure adjustment means Cb is connected to the left front wheel brake through the oil passage 8b. It is connected to the wheel cylinder hydraulic chamber ₉₂ of the brake wheel cylinder _Bf2 . In this way, the right front wheel brake wheel cylinder Bf ₁ and the left rear wheel brake wheel cylinder Br ₂ are included in the first braking hydraulic system by the first output port 4a, and the left front wheel brake wheel cylinder Bf _{2 and the right rear wheel brake wheel cylinder Bf 1} are included in the first brake hydraulic system connected to the first output port 4a. The wheel brake wheel cylinder Br ₁ is included in the second brake hydraulic system connected to the second output port 4b, and the oil passages of both brake hydraulic systems constitute a so-called X-shaped pipe.

The first and second brake hydraulic pressure adjusting means Ca and Cb have exactly the same configuration, and below, only the configuration of the first brake hydraulic pressure adjusting means Ca will be described in detail with the subscript a, and the second brake hydraulic pressure adjusting means The portion of the means Cb corresponding to the first braking oil pressure adjusting means Ca is only shown with the suffix b.

The first braking oil pressure adjusting means Ca includes a cylinder portion 13a whose one end is closed by an end wall 11a and whose other end is closed by a cap 12a;
The rod 17a has pistons 15a and 16a at both ends thereof, and passes through the partition wall 14a in the axial direction between the pistons 15a and 16a. A primary braking hydraulic chamber 18a is defined between the partition wall 14a and the piston 15a, a secondary braking hydraulic chamber 19a is defined between the partition wall 14a and the piston 16a, and a secondary braking hydraulic chamber 19a is defined between the end wall 11a and the piston 15a. An anti-lock control hydraulic chamber 20a is defined.

A compression spring 2 is provided between the end wall 11a and the piston 15a in the anti-lock control hydraulic chamber 20a.
A compression spring 22a is interposed between the piston 16a and the partition wall 14a in the secondary brake hydraulic chamber 19a. These compression springs 2
Due to the elastic restoring action of 1a and 22a, each piston 15a and 16a is always held at a predetermined position when not braking.

The antilock control oil pressure chambers 20a, 20b of the first and second braking oil pressure adjusting means Ca, Cb are supplied with or discharged from the antilock control oil by operating the pressure guiding and exhaust pressure control valves _CV1 , _CV2 . Further, first and second braking oil pressure adjusting means Ca,
The cylinder chambers between the caps 12a, 12b and the pistons 16a, 16b in Cb are communicated with the oil tank 3 via oil passages 24a, 24b as open oil chambers 23a, 23b, respectively.

A pair of first and second proportional pressure reducing valves Va, Vb are
It is provided to control the primary brake hydraulic pressure immediately after control is started, so that the braking force to the rear wheels is smaller than the braking force to the front wheels, and the axes of these are parallel to each other and in the opening/closing operation direction. are arranged in the same way. These proportional pressure reducing valves
Va and Vb have exactly the same configuration, and below,
Only the first proportional pressure reducing valve Va will be described in detail with the subscript a, and the structure of the second proportional pressure reducing valve Vb will only be illustrated with the subscript b attached to the corresponding parts.

The first proportional pressure reducing valve Va has an input hydraulic chamber 27a communicating with an inlet 26a communicating with the oil passage 6a, and an oil passage 7.
Output hydraulic chamber 2 communicating with outlet 28a communicating with a
9a, a piston 30a that is displaced within both hydraulic chambers 27a and 29a, and an output hydraulic chamber 2 of the piston 30a.
Valve seat 31 fixedly provided at one end near 9a
a, and a valve body 32a provided opposite to the valve seat 31a. The other end of the piston 30a is
Cap 33 for closing the input hydraulic chamber 27a
a freely displaceable in the axial direction and in an oil-tight manner. A flange 34a extending radially outward is provided in the middle of the piston 30a, and this flange 34a and
A seal member 35a is supported by the cap 33a and performs a sealing function by slidingly contacting the outer peripheral surface of the piston 30a.
A spring 36a is interposed between the two. The spring force of the spring 36a urges the piston 30a toward the output hydraulic chamber 29a.

An oil passage 37a extending in the axial direction is formed closer to one end than the collar 34a of the piston 30a, and a valve seat 31a concentrically communicates with this oil passage 37a.
is fixed. This oil passage 37a is connected to the piston 30a.
It communicates with the input hydraulic pressure chamber 27a through a through hole 38a extending in the radial direction. Further, the valve body 32a is connected to the valve seat 3.
It is arranged in the oil passage 37a opposite to 1a,
A support rod 39a that penetrates through the valve seat 31a and can come into contact with the end wall of the output hydraulic chamber 29a is concentrically fixed to the valve body 32a. The support rod 39a is the piston 30a
At the same time, by being displaced toward and abutting against the end wall, the valve body 32a has a function of separating the valve body 32a from the valve seat 31a, that is, opening the valve. moreover,
In the oil passage 37a, the valve body 32a and the piston 3
A spring 40a is interposed between the
It is urged toward 1a.

In such a first proportional pressure reducing valve Va, when the oil pressures of the input and output oil pressure chambers 27a and 29a reach a predetermined value, the oil pressure acting on the piston 30a causes a downward pressing force in the drawing (the input oil pressure chamber 27a of the piston 30a). (corresponds to the side cross-sectional area A multiplied by the hydraulic pressure of the input and output hydraulic chambers 27a, 29a) overcomes the biasing force applied to the piston 30a by the spring 36a and moves the piston 30a downward in the drawing. Thereby, the valve body 32a is moved to the valve seat 31a.
, the input hydraulic chamber 27a and the output hydraulic chamber 29a are shut off. After that, the input hydraulic chamber 27a
When the hydraulic pressure increases, the upward pressing force of the piston 30a due to the hydraulic pressure in the input hydraulic chamber 27a (the difference between the cross-sectional area B of the sliding part of the piston 30a with the output hydraulic chamber 29a and the cross-sectional area A) Hydraulic chamber 27
It is approximately equivalent to the oil pressure multiplied by a. Furthermore, B＞
It is A. ) is the downward pressing force of the piston 30a due to the hydraulic pressure of the output hydraulic chamber 29a (the cross-sectional area B
It approximately corresponds to the value obtained by multiplying by the oil pressure of the output oil pressure chamber 29a. ), the piston 30a is pushed back upwards, and the valve body 32a is separated from the valve seat 31a. Therefore, the two hydraulic chambers 27a and 29a are communicated again, and the hydraulic pressure in the output hydraulic chamber 29a rises accordingly.
The downward pressing force of the piston 30a due to the oil pressure of a increases immediately, the piston 30a moves downward again, and the two hydraulic chambers 27a and 29a are cut off. Thereafter, the same operation is repeated as the hydraulic pressure acting on the input hydraulic chamber 27a from the inlet 26a increases. As a result, the output oil pressure of the first braking oil pressure adjustment means Ca is proportionally reduced, and the left rear wheel wheel cylinder oil pressure chamber 1
0 ₂ is transmitted.

A bottomed control cylinder portion 41 having an axis parallel to the axes of the proportional pressure reducing valves Va and Vb is provided between the proportional pressure reducing valves Va and Vb, and a control piston 42 is slidably engaged with the control cylinder portion 41. At one end of the control piston 42 protruding from the control cylinder portion 41, there is a connecting member 43 extending in the direction of both the proportional pressure reducing valves Va and Vb.
is fixed. Moreover, both ends of the connecting member 43 are
Pistons 30a and 30b of both proportional pressure reducing valves Va and Vb
The pistons 30a, 30b are inserted into the control piston 42 while allowing relative movement in the axial direction by a small distance δ. An oil passage 44 is opened at the bottom of the control cylinder portion 41, and anti-lock control hydraulic pressure is applied to the other end of the control piston 42 via the oil passage 44 by the operation of the pressure guiding and exhaust pressure control valve _CV3 . act.

Next, I will explain the anti-lock control system.
For example, control oil pressurized by a hydraulic source P such as a plunger pump passes through a check valve 45 and an oil path 47 that communicates with a pressure accumulator 46 midway through each pressure control valve CV ₁ , CV ₂ , sent to CV ₃ .
Further, control oil discharged from each pressure guiding and exhaust pressure control valve CV ₁ , CV ₂ , CV ₃ is sent to an oil tank 49 via an oil path 48 . After the control oil in the oil tank 49 passes through a filter 50, it passes through an oil passage 51 and a check valve 52, and is again pressurized by the hydraulic source P.

Next, the operation of this embodiment will be explained. When the brake pedal 2 is depressed during braking, the brake hydraulic pressure generated in the master cylinder 1 is transferred to the oil passage 5a,
first and second brake hydraulic pressure adjusting means via 5b;
The hydraulic pressure is transmitted to each of the primary brake hydraulic chambers 18a and 18b of Ca and Cb. As a result, the pistons 15a, 15 in the first and second braking oil pressure adjusting means Ca, Cb
b moves in the direction approaching the end walls 11a, 11b, and secondary braking oil pressure is generated in the secondary braking oil pressure chambers 19a, 19b, and this secondary braking oil pressure is transferred to the oil passages 8a, 8b.
Through the foil cylinder Bf ₁ for both front wheel brakes,
The pressure is transmitted to the wheel cylinder hydraulic chambers 9 ₁ and 9 ₂ of Bf ₂ , respectively. On the other hand, each primary brake hydraulic chamber 18a, 1
The primary braking oil pressure of 8b is proportionally reduced by the proportional pressure reducing valves Va and Vb, and the wheel cylinder oil pressure chambers 10 ₁ and 10 ₂ of the wheel cylinders Br ₁ and Br ₂ for both rear wheel brakes are proportionally reduced.
are transmitted to each. In this way, the left and right front wheels receive a braking force, and a smaller braking force is applied to the left and right rear wheels.

During braking, when one of the left and right front wheels, for example the right front wheel, locks, the pressure guide and exhaust pressure control valve CV ₁ is displaced to the left position in the drawing by the operation of a control means (not shown). As a result, the control oil sent from the hydraulic source P is immediately introduced into the antilock control hydraulic chamber 20a, and presses the pistons 15a and 16a toward the right side in the drawing. As a result, the secondary brake hydraulic chamber 19
The secondary braking oil pressure in a decreases, the braking force applied to the right front wheel by the right front wheel brake wheel cylinder _Bf1 decreases, and the locked state is released. This is the same when the front left wheel is locked, and the pressure guiding and exhaust pressure control valve CV ₂ is activated to supply anti-lock control oil to the anti-lock control hydraulic chamber 20b, thereby releasing the locked state of the front left wheel. be done.

Furthermore, when at least one of the left and right rear wheels approaches a lock state during braking, the pressure guiding and exhaust pressure control valve CV ₃ is displaced to the left position in the drawing by a control means (not shown), and the anti-lock from the hydraulic source P is moved. Control oil is introduced into the control cylinder portion 41 via the oil passage 44 . As a result, the control piston 42 is pushed downward in the drawing, and via the connecting member 43 pushes the pistons 30a, 30b of both proportional pressure reducing valves Va, Vb in the valve closing direction. Therefore, both proportional pressure reducing valves Va and Vb
In this case, the valve bodies 32a, 32b are provided with a valve seat 31a,
31b comes into contact with the oil passages 37a and 37b, and the left and right rear wheel brake wheel cylinders Br ₁ ,
The supply of brake oil to each wheel cylinder hydraulic chamber 10 ₁ , 10 ₂ of Br ₂ is cut off. And piston 30
In response to the movement of valves a and 30b in the valve closing direction, the hydraulic pressure in the output hydraulic chambers 29a and 29b is reduced, and the braking force exerted on the left and right rear wheels by the respective wheel cylinders Br ₁ and Br ₂ is weakened, thereby avoiding a locked state. .

As described above, according to the present invention, a pair of proportional pressure reducing valves are arranged in parallel, and a control cylinder part for sliding a control piston is arranged in parallel between both proportional pressure reducing valves, and a connection fixed to the control piston. The member has an extremely simple structure in which each piston of both proportional pressure reducing valves is connected to each other by allowing relative movement in the axial direction with respect to the control piston by a distance necessary for proportional pressure reducing operation, so that the rear wheel is likely to lock. By driving the control piston when the pressure is released, both proportional pressure reducing valves can be closed simultaneously, weakening the braking force on the rear wheels and exerting the anti-lock function.

[Brief explanation of drawings]

The drawing is a hydraulic circuit diagram of an embodiment of the present invention. 1...Master cylinder, 4a, 4b...Output port, 5a, 5b, 6a, 6b, 7a, 7b, 4
4... Oil path, 30a, 30b... Piston, 41
... Control cylinder section, 42 ... Control piston, 4
3... Connection member, Va, Vb... proportional pressure reducing valve.

Claims (1)

[Claims] 1 A pair of proportional pressure reducing valves capable of proportionally reducing and transmitting the output hydraulic pressure of the output port are interposed in a pair of oil passages connecting a pair of output ports of a master cylinder and a pair of rear wheel brakes. In the vehicle brake hydraulic control valve device, both proportional pressure reducing valves are
Each piston is biased by a spring in the valve opening direction and moves to a position where the output side can be depressurized when the valve is closed, and the pistons are arranged so that their axes are parallel to each other and the opening and closing directions are the same,
A control cylinder portion for sliding a control piston is disposed in parallel between both proportional pressure reducing valves, and anti-lock control hydraulic pressure is applied to the control cylinder portion when the rear wheels are about to enter a lock state. An oil passage is connected to move the control piston in the closing direction of both proportional pressure reducing valves, and a connecting member fixed to the control piston is configured to move relative to the control piston in the axial direction by a distance necessary for the proportional pressure reducing operation. A brake hydraulic control valve device for a vehicle, characterized in that each piston of both proportional pressure reducing valves is connected in a permissive manner.