JPS5836611Y2 - Deceleration responsive hydraulic control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deceleration-responsive hydraulic pressure control valve that controls brake fluid pressure transmitted to rear wheel brakes in response to deceleration occurring in a vehicle when the brakes of a vehicle are applied.

Conventionally, this type of deceleration-responsive hydraulic pressure control valve has been used to optimally control the brake fluid pressure supplied to the rear wheel brakes without being affected by the vehicle's loading status, so that the deceleration of the vehicle remains at a constant value. The control start fluid pressure is determined based on the brake fluid pressure when the brake fluid pressure is reached, and when the brake fluid pressure supplied from the master cylinder becomes equal to or higher than the control start fluid positive, the brake fluid pressure supplied to the rear wheel brakes is changed to It was designed to reduce the amount to a predetermined ratio for each model.

However, due to the characteristics of the vehicle, the load applied to the rear wheels changes greatly depending on the loaded state, and when the load is empty, the load is small, but when fully loaded, it becomes significantly large. In other words, there is a risk that the rear wheels will lock up when the deceleration that occurs in the vehicle is small, but as the load on the vehicle increases, the braking force required by the rear wheels increases, and the rear wheels increase accordingly. The ring becomes difficult to lock.

Therefore, it is desirable to increase the vehicle deceleration value that defines the control start hydraulic pressure of the deceleration-responsive hydraulic pressure control valve in accordance with the loaded weight of the vehicle.

The present invention was developed to satisfy the above requirements, and is a brake system that increases the vehicle deceleration value that defines the control start fluid pressure in accordance with the brake fluid pressure transmitted from the master cylinder. It is an object of the present invention to provide a speed responsive hydraulic pressure control valve.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

In the figure, 1 is a main body of a deceleration-responsive hydraulic pressure control valve, inside which a cylinder hole 2 and a hole 3 are provided, and inside the cylinder hole 2 there is a step having a large diameter part 4 and a small diameter part 5. A control piston 6 and a control piston 7 are slidably inserted.

The single-stage piston 6 has a right side portion of its small diameter portion 5 slidably fitted into a hole 8 formed in the control piston 7, and a valve provided inside the left side thereof. A valve member 10 and a valve spring 11 for biasing the valve member 10 against its valve seat 10a are provided in the chamber 9.

The valve member 10 and the valve seat 10a constitute a valve means.

An outlet chamber 12 formed between the left side of the stepped piston 6 and the left closed end of the cylinder hole 2 is connected to a rear wheel brake (not shown) via a connection port 13, and is also connected to a rear wheel brake (not shown) through a connection port 13. It communicates with the valve chamber 9 via a passage 14 and valve means 10, 10a.

An inlet chamber 15 defined between the stepped piston 6 and the control piston 7 is connected to a master cylinder (not shown) via a connection port 16 and to the valve chamber 9 via a fluid passage 17. , communicates with the inside of the hole 3 via the liquid passage 18.

Also, a blind cover 20 that fits into the right end of the cylinder hole 2 and is prevented from being removed by a retaining ring 19, that is, the cylinder hole 2
A control chamber 21 is located between the right closed end of the control piston 7 and the control piston 7.
is formed.

Reference numeral 23 denotes an air chamber, which is formed across the inside of the hole 24 bored in the small diameter portion 5 of the stepped piston 6 and the hole 8 of the control piston 7.

The preload spring 25 includes a spring receiver 26 in contact with the stepped portion 6a of the stepped piston 6 and a spring receiver 2 in contact with the left end of the control piston 7.
The tension, that is, the biasing force that biases the stepped piston 6 to the left, is set between the stepped piston 6 and
The left end of the valve member 1 is brought into contact with the left end wall of the cylinder hole 2.
0 is removed from the valve seat 10a.

28, 29, 30, and 31 are sealing materials, respectively.

Reference numeral 40 denotes a ball valve of a deceleration responsive valve, which is disposed so as to be able to slide or roll on a guide surface 42 of a guide member 41 disposed in the hole 3, and is press-fitted into the left end of the liquid passage 20. supporting member 43
It can be seated on a valve seat 44 mounted on the left side of the valve.
When the ball valve 40 is in the position shown in the figure, the support member 43 is located inside the hole 3.
When the ball valve 40 moves to the right, the valve seat 44
The control room 21 is shut off from the hole 3 by sitting on the seat.

47 is a hydraulic response piston whose upper part protrudes into the hole 3, and whose upper end abuts against the lower surface of the guide member 41 to support the guide member 41, and which is connected to a flange part 48 provided at the center thereof. A spring 51 is stretched between the spring receiver 50 and the spring receiver 50, which is prevented from being removed by a retaining ring 49.

Therefore, the hydraulic response piston 47 receives the brake fluid pressure in the hole 3 on its upper surface, compresses the spring 51 according to the height of the brake fluid pressure, moves downward, and moves the guide member 410 on the guide surface 42. It is possible to tilt the inclination angle by a maximum of 01 degrees.

52 is a sealing material. 53 is a blind lid fitted into the left opening end of the hole 3, and a sealing material 54 is attached to the outer periphery.
Removal is prevented by a retaining ring 55.

56 is an air vent valve, and 57 is an adjustment spring.

The main body 1 is mounted to the vehicle body through mounting holes 60 and 60' so that its right side faces the front of the vehicle, and its center line extending left and right with respect to the horizontal plane H forms an angle θ2 to the right.

Therefore, the sum of this angle θ2 and the inclination angle of the guide surface 42 given by the displacement of the hydraulic pressure responsive piston 47 defines the deceleration of the vehicle when the one-ball valve 40 moves to the right.

Next, the operation of this embodiment will be explained.

When the driver depresses the brake pedal to apply the brakes to the vehicle and brake fluid pressure is generated in the master cylinder, the brake fluid is supplied to the front wheel brakes and is also supplied to the inlet chamber 15 from the connection port 16.

When the hydraulic pressure is sufficiently low and sufficient deceleration does not occur in the vehicle to move the ball valve 40 to the right, the stepped piston 6 is biased to the left by the preload spring 25. Since the valve member 10 is separated from the valve seat 10a, the brake fluid supplied to the inlet chamber 15 flows through the liquid passage 17 and the valve seat 9.
, is supplied to the outlet chamber 12 through the liquid passage 14, and is connected to the connection port 1.
3 is supplied to the rear wheel brakes.

Therefore, brakes are applied to the front wheels and rear wheels, causing deceleration of the vehicle.

The brake fluid supplied to the inlet chamber 15 is simultaneously supplied to the outlet chamber 12 and into the hole 3 through the fluid passage 18, but since the ball valve 40 is in the left position as shown in the figure. , and is further supplied to the control chamber 21 through liquid passages 45, 20, and 46.

Therefore, the same hydraulic pressure acts on the control piston 7 from both sides, but the pressure receiving area of the control piston 70 facing the inlet chamber 15 is larger than the pressure receiving area of the stepped piston 70 facing the control chamber 21.
Since the cross-sectional area of the small diameter portion 5 is smaller by S1, when the brake fluid pressure is P, the control piston 7 is pushed to the left by a force of S1 and P.

When this pressing force S1.P becomes larger than the differential force obtained by subtracting the tension of the adjustment spring 57 that pushes the control piston γ to the left from the tension of the preload spring 25 that pushes the control piston 7 to the right, the control piston 7 compresses the preload spring 25 and moves to the left, increasing the biasing force of the preload spring 25 that biases the stepped piston 6 to the left.

Therefore, the value of the brake fluid pressure that starts to move the brake piston 7 to the left is adjusted by appropriately setting the tension of the adjustment spring 57.

The brake fluid supplied to the hole 3 in the housing presses the upper surface of the ME response piston 47, so the fluid response piston 47 compresses the spring 51 and moves downward, moving the guide surface 42 of the guide member 41 to the left. Installed on the downhill side.

Now, when the brakes are applied when the vehicle is fully loaded or lightly loaded, the ratio of vehicle deceleration to the brake fluid pressure is large, so the brake fluid pressure supplied to the inlet chamber 15 and the hole 3 is relatively low and the liquid drops. While the inclination angle of the guide surface 42 due to the downward movement of the response piston 47 is small, a deceleration sufficient to move the body valve 40 to the right occurs.

Therefore, due to the relatively small deceleration of the vehicle defined by the sum of the inclination angle of the guide surface 42 and the mounting angle θ2, the body valve 40 moves to the right, seats on the valve seat 44, and performs control. The brake fluid in the chamber 21 is sealed.

Therefore, even if the brake fluid pressure supplied to the inlet chamber 15 and the hole 3 via the connection port 16 further increases, brake fluid is no longer supplied to the control chamber 21 and the control piston 1 moves to the left. Never.

Therefore, the biasing force of the preload spring 25 is determined by the hydraulic pressure when the body valve 40 blocks the liquid passage 45.

Then, the brake fluid pressure supplied to the population chamber 15 further increases, and the force that pushes the stepped piston 6 to the right, that is, the exit chamber 12 exerts a force on the cross-sectional area S2 of the large diameter portion 4 of the stepped piston 60.
The liquid pressure S2. P is the force that pushes the stepped piston 6 to the left,
In other words, the fluid pressure (Sz
-8l).

The sum of P and the biasing force F of the preload spring 25 (Sz-8t).

When P+F is greater than P+F, the stepped piston 6 moves to the right and closes the fluid communication between the inlet 15 and the outlet chamber 12 by the valve means 10.1.
0a, and control of the brake fluid pressure supplied from the outlet chamber 12 to the rear wheel brakes begins.

This control starting hydraulic pressure P. From the above relationship, Sz・Pcm(Sz-81)・Pc+F 2.sl and is proportional to the biasing force F of the preload spring 25.

Then, when the brake fluid pressure in the inlet chamber 15 further increases from the control start fluid pressure, the stepped piston 6 moves to the left due to the increased fluid pressure, and the valve member 10 moves away from its valve seat 10a. Pressure is transmitted to the outlet chamber 12.

As a result, the hydraulic pressure in the outlet chamber 12 increases, and the stepped piston 6
is pushed to the left again to cut off fluid communication between both chambers 15 and 12.

By repeating this operation, the brake fluid pressure in the outlet chamber 12 is controlled, so the increase in the brake fluid pressure in the outlet chamber 12 is as follows: Let Po be the fluid pressure in the outlet chamber 12, and PI be the fluid pressure in the inlet chamber 15. From the relationship Sz・Po−(Sz−8i)・P1+F, the increase in fluid pressure in the inlet chamber 15 (S2+31)
/S2.

Therefore, an excessive braking force is not generated on the rear wheel brake, and skid is prevented.

Next, when the brakes are applied while the vehicle is fully loaded or close to being fully loaded, the body valve 40 begins to move to the right, since a sufficiently high brake fluid pressure is required to cause the vehicle to decelerate to a predetermined value. Sufficiently high liquid pressure is supplied to hole 3 before
The hydraulic pressure causes the hydraulic pressure-responsive piston 47 to be pushed down significantly, and the inclination angle of the guide surface 42 increases.

Then, when a large deceleration defined by the sum of the inclination angle of the guide surface 42 and the mounting angle θ2 occurs in the vehicle,
The body valve 40 moves to the right against the inclination angle of its guide surface 42, seats on the valve seat 44, seals the brake fluid in the control chamber 21, and transfers the biasing force of the preload spring 25 to the body valve 40. The brake fluid pressure is maintained at a value corresponding to the brake fluid pressure when the fluid passage 45 is closed.

When the hydraulic pressure in the inlet chamber 15 increases and becomes equal to or higher than the control start hydraulic pressure determined by the above-mentioned biasing force, the hydraulic pressure in the outlet chamber 12 increases due to the same effect as in the case of the fully loaded or lightly loaded state described above. The increase in hydraulic pressure in chamber 15 is reduced.

Therefore, the inclination angle of the guide surface 42 of the guide member 410 changes depending on the brake fluid pressure supplied from the master cylinder to the hole 3. When the hydraulic pressure is low, the inclination angle of the guide surface 42 is small, and when the fluid pressure is high, the guide surface 42 is increased, when the vehicle is in a lightly loaded state, the body valve 40 operates based on the relatively low deceleration of the vehicle to set the control start hydraulic pressure, and when the vehicle is in a heavily loaded state. sets a higher control start hydraulic pressure based on high vehicle deceleration.

As is clear from the above explanation, the present invention limits the biasing force of the preload spring that biases the stepped piston by the brake fluid pressure when the deceleration of the vehicle reaches a predetermined value, and The predetermined value of is increased or decreased depending on the brake fluid pressure supplied from the master cylinder, so when the vehicle is lightly loaded, a low control start fluid pressure is set to prevent the rear wheels from locking, and when the vehicle is lightly loaded, In this state, the response vehicle deceleration of the deceleration responsive valve is increased, a higher control start hydraulic pressure is set, and sufficient brake hydraulic pressure can be supplied to the rear wheel brakes.

[Brief explanation of drawings]

The figure shows a sectional view of a deceleration responsive hydraulic pressure control valve showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Main body, 2... Cylinder hole, 6... Stepped piston, 7... Control piston, 10, 10a... Valve means, 12... Outlet chamber, 15... Inlet chamber , 21...
Control room, 23... Air chamber, 25... Preload spring, 4
0... Deceleration response valve, 41... Guide member, 42...
- Guide surface, 44... Valve seat, 47... Hydraulic pressure responsive piston.

Claims (1)

[Scope of utility model registration request] A stepped piston and a control piston that are slidably inserted into the cylinder hole of the main body and are movable with respect to each other, and an outlet chamber formed between the stepped piston and one closed end of the cylinder hole. A valve means for opening and closing a liquid passage with an inlet chamber formed between the pistons, a preload spring stretched between both pistons and urging the stepped piston in a direction to open the valve means, a control piston and a cylinder. A deceleration-responsive valve that opens and closes a liquid passage between the control chamber and the inlet chamber formed between the other closed end of the hole in response to vehicle deceleration, and a guide that guides the deceleration-responsive valve. a deceleration-responsive hydraulic pressure control valve having a guide member having a surface and defining the deceleration of the vehicle according to an inclination angle of the guide surface with respect to a horizontal plane; A deceleration responsive hydraulic pressure control valve comprising a hydraulic responsive device that moves in response to brake fluid pressure supplied to the guide surface and changes the inclination angle of the guide surface.