JPS6124435Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a hydraulic pressure control valve used in a two-system control device provided in a vehicle.

In vehicles such as automobiles, it is common practice to connect the master cylinder and each wheel cylinder through two mutually independent piping systems in order to obtain highly reliable and stable braking force. One type of piping is called X-shaped (cross) piping. The left front and rear wheels are connected in an X-shape by two piping systems, such as the front left wheel and the rear right wheel, and the front right wheel and the rear left wheel. Although the number of pipes and joints is reduced, even if a failure occurs in one of the piping systems, the braking force of the diagonally located front and rear wheels is maintained.

In a two-system control system equipped with this cross piping, a hydraulic pressure control valve is generally provided in order to ensure the stability of the vehicle during braking.
If a sudden braking force is applied to the vehicle and the center of gravity moves toward the front wheels, the rate of increase in the brake fluid pressure of the rear wheels in the range exceeding a certain brake fluid pressure (node point fluid pressure) is compared to that of the front wheels. This also reduces the braking force ratio between the front and rear wheels to bring it closer to the ideal distribution.
In the event that one of the two systems fails, instability during braking can be reduced by increasing the turning point hydraulic pressure value and compensating for the lack of braking force at the rear wheels, which carry the vehicle's braking load. to improve. Proportioning valves (hereinafter simply referred to as "P valves") are used as hydraulic control valves because they have a simple structure and reliable operation, and are arranged in parallel within a single housing. Some valve pistons are biased into the housing by a single spring mechanism with a pushing force that follows the same spring characteristics. This is the hydraulic control valve that the present applicant previously filed as Utility Model Application No. 130997/1984 (Kokai No. 46453/1983).

With such conventional hydraulic pressure control valves, there is no difference in the braking fluid pressure transmitted to the rear wheel cylinder, regardless of differences in the operating characteristics of both valve pistons due to variations in the machining accuracy of valve parts, etc. Although there are advantages, since the spring mechanism is disposed outside the housing, there is a disadvantage that the external size of the hydraulic control valve that encloses the cover that accommodates the spring mechanism becomes large. Particularly with the increase in the number of components mounted on vehicles in recent years, it is desirable to have a hydraulic pressure control valve that is as small and lightweight as possible.

The present invention was developed against the background of the above circumstances, and its purpose is to provide a system in which two valve pistons are arranged in parallel in a single housing, with one end of each valve piston exposed outside the housing. Each valve piston is pushed out of the housing by a certain length by the brake fluid pressure of each independent system, and by closing the on-off valve provided in the brake fluid passage of each system, each valve piston is released from the hydraulic pressure source. It is a control valve that reduces the brake fluid pressure transmitted to the left and right rear wheel cylinders at a fixed ratio.When both systems are normal, the pressure is reduced almost equally on the left and right, and one piping system is damaged. The objective is to create a small and lightweight device that can increase the normal hydraulic pressure in such a state.

To achieve this objective, the hydraulic control valve according to the present invention (a) is fitted around the outer periphery of each valve piston within the single housing, and biases each valve piston toward the housing, respectively; 2
(b) extending in a direction perpendicular to both exposed ends of the two valve pistons, the intermediate two portions being disposed at the exposed ends of the respective valve pistons; and an adjusting member which is rotatably engaged in a plane including the center and substantially immovably in the axial direction of the valve piston, and whose opposite ends are respectively opposed to the housing; When the distance between both ends of the adjustment member and the housing is such that one of the two valve pistons is at the most pushed into the housing, the other valve piston engages the adjustment member with the one valve piston. When the adjusting member is pushed out of the housing while being rotated about the other valve piston, the end of the adjusting member on the one valve piston side contacts the housing before the on-off valve corresponding to the other valve piston is closed. selected.

In the hydraulic control valve configured in this way,
Errors in the lengths of the two valve pistons, errors in the lift amount (distance between the open and close positions of the on-off valve), etc. are absorbed by the rotation of the adjustment member.

Also, based on differences in the spring characteristics of the coiled spring that biases the valve piston into the housing, the sliding resistance of the valve piston, etc., if one of the valve pistons starts moving before the other valve piston. , the adjusting member rotates around the engagement portion with the valve piston on the stationary side, and the end on the stationary valve piston side comes into contact with the housing. At this point,
The on-off valve corresponding to the valve piston that started moving first is also not closed. Then, the hydraulic pressure acting on the two valve pistons increases further, causing 2
When the force pushing the valve piston out of the housing overcomes the biasing force of the two coiled springs, the valve piston, which had been stationary until then, also started moving, and it started moving first. The on-off valve on the valve piston side is closed, and then the on-off valve on the other valve piston side is closed. In other words, the closing timing of the on-off valve corresponding to the valve piston that starts moving first is delayed compared to when there is no adjustment member, and as a result, the braking fluid transmitted to the left and right rear wheel cylinders is delayed. The pressure will be reduced almost evenly.

On the other hand, if one system is damaged, the valve piston of the normal system will start moving, and one end of the adjustment member will be in contact with the housing, which is the same as in the above case. Since the pushing force based on hydraulic pressure does not act on the valve piston of the damaged system, the valve piston of the normal side cannot close the on-off valve unless it independently compresses two coiled springs. The point liquid pressure will be higher than when the two systems are normal.

In this way, the hydraulic control valve according to the present invention reduces the braking hydraulic pressure transmitted to the left and right rear wheel cylinders almost equally when the two systems are normal, but when one system is damaged, the hydraulic pressure at the corner of the normal system is reduced. Since a coiled spring, which can increase the temperature and requires a considerable length, is fitted around the outer periphery of the valve piston inside the housing, it is sufficient to provide an adjustment member outside the housing, instead of the conventional Compared to the case where the spring is disposed outside the housing, the mechanical part outside the housing becomes more compact, and as a result, the entire hydraulic pressure control valve can be made smaller and lighter.

Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

In FIG. 1, 2 is a P valve, and its outer shell is composed of a housing 4 and a cover 6 fixed to the housing. The housing 4 has valve chambers 8L and 8R opened in parallel on one end surface, and each of the valve chambers 8L and 8R has a disk-shaped valve at its inner end (upper end in FIG. 1). Body 10L, 1
Valve piston 12 in which 0R is coaxially formed
L and 12R are respectively inserted, and the valve chamber 8
Valve piston 1 is installed in the center hole in the openings of L and 8R.
The lids 14L and 14R, through which the lower ends of the exposed ends of the openings 2L and 12R are inserted, are respectively fitted and prevented from coming off by a snap ring 15 that is locked to the inner peripheral surface of the opening. Lid body 14L, 14
A seal ring 16 for sealing between the openings of the valve chambers 8L and 8R is attached to the outer periphery of R, and valve pistons 12L and 12R are installed around the center holes of the lids 14L and 14R. By installing an oil seal 18 that seals between the valve chambers 8L and 8R, the valve chambers 8L and 8R are kept oil-tight while allowing the valve pistons 12L and 12R to move in the axial direction.

The valve chambers 8L, 8R communicate with input ports 20L, 20R to which hydraulic pressure is supplied and first output ports 24L, 24R that transmit the hydraulic pressure to wheel cylinders 22L, 22R of the front wheels, which will be described later. At the top of chambers 8L and 8R are valve pistons 12L,
Valve seats 26L, 26R are provided so that the valve bodies 10L, 10R come into contact when the valve 12R moves in its axial direction (downward in FIG. 1). The sides of the valve seats 26L, 26R with the valve bodies 10L, 10R (upper side in Figure 1) are second output ports 30L, 30R for outputting controlled hydraulic pressure to the rear wheel cylinders 28R, 28L, which will be described later. is communicated with. Valve bodies 10L, 10R and valve seats 26 are installed in the middle of the liquid passage from the input ports 20L, 20R to the second output ports 30L, 30R.
An on-off valve consisting of L and 26R is provided.

Ring-shaped protrusions 32L, 32R are formed on the outer periphery of the upper end of the valve pistons 12L, 12R, and the valve pistons 12L, 12R are fitted between the ring-shaped protrusions 32L, 32R and the inner surfaces of the lids 14L, 14R. In this state, compressed coil springs 34L and 34R with equal biasing forces are interposed coaxially. Therefore, the valve piston 12
L and 12R are always urged in the direction of being pushed into the housing 4. Note that 36 is a spring receiver disposed between the coiled springs 34L, 34R and the inner surfaces of the lids 14L, 14R.

A bolt 40 having a stepped portion 38 having a diameter larger than the threaded portion between the head and the threaded portion is screwed onto the end face of the exposed end of the valve pistons 12L and 12R. , the two intermediate portions of the long plate-shaped connecting rod 42 serving as the adjusting member can be rotated to the exposed end portions of the valve pistons 12L, 12R, respectively, and the valve pistons 12L,
12R is engaged so as to be substantially immovable in the axial direction. That is, in the middle part of the connecting rod 42, there are two through holes 4 with counterbored openings on both sides.
4 is formed, and a stepped portion 38 having a diameter approximately 0.1 to 0.2 mm longer than the depth dimension of the through hole 44 not including the counterbore portion and approximately 0.1 to 0.2 mm smaller than the inner diameter thereof is the through hole. Bolt 4 is loosely fitted into 44.
0 is engaged with the counterbore of the connecting rod 42. The diameter of the counterbore portion is formed to be sufficiently larger than the diameter of the lower end portions of the valve pistons 12L, 12R and the diameter of the head portion of the threaded bolt 40.

Protrusions 46 for contact are provided at both ends of the connecting rod 42 toward the housing 4, and the valve pistons 12L, 12R are pushed into the housing 4 as far as possible according to the urging force of the coiled springs 34L, 34R. When the projection 4 is in the
6 and the surface of the housing 4 facing the protrusion 46, a substantially equal constant distance D is formed therebetween.

This connecting rod 42 and valve piston 12L, 1
The exposed end of 2R is covered with a cover 6 for dust prevention.

As described above, according to this embodiment, the coiled springs 34L, 34R, which require a large length in the axial direction in order to apply a biasing force to the valve pistons 12L, 12R,
Since it is housed in the housing 4 in parallel with R, the height dimension of the cover 6 is extremely small compared to a conventional hydraulic control valve housed in the cover 6.
The entire hydraulic pressure control valve 2 includes a valve piston 12L,
The dimension of 12R in the axial direction (vertical direction in FIG. 1) is significantly reduced. In addition, since no force such as a spring is applied to the cover 6, lighter materials such as thinner plates and synthetic resins can be used compared to conventional cases where the function as a strength member is required. Coupled with the miniaturization of the cover 6, its weight can be significantly reduced, and the weight of the hydraulic control valve as a whole can be reduced. Furthermore, connecting rod 4
Since load such as the biasing force of a spring is not constantly applied to 2, there is an advantage that consideration for strength such as long-term fatigue and wear is not required.

The P valve 2 configured as described above is used by being connected via piping within two systems of braking devices. That is, the brake pedal 50 is connected to the master cylinder 48.
Output ports 52 and 54 are provided so as to independently generate equal hydraulic pressure by operating the left front wheel wheel cylinder 22.
L through the input port 20L and first output port 24L of the P valve 2, and the output port 54 is connected to the wheel cylinder 22R of the right front wheel through the input port 20R and the first output port 24R of the P valve 2. It is connected. The second output port 30L of the P valve 2 is connected to the wheel cylinder 28R of the right rear wheel, and the second output port 30R is connected to the wheel cylinder 28R of the left rear wheel.
Connected to L. In this way, P of this example
Since the valve 2 is equipped with the first output ports 22L and 22R, the output port 5 of the master cylinder 48
From 2,54 to the left and right front wheel cylinders 22
There is an advantage that piping parts such as T-shaped pipe joints for branching to L and 22R are not required.

The operation of this embodiment will be explained below.

When the brake pedal 50 is depressed while the piping system is in a normal state, equal hydraulic pressures are generated at the output ports 52 and 54 of the master cylinder 48. Of these, the hydraulic pressure at the output port 52 is the P valve 2.
input port 20L and wheel cylinder 22L
is transmitted to. While the brake fluid pressure is lower than a predetermined value, the valve piston 12L is pressed against the upper end of the valve chamber 8L by the urging force of the coiled spring 34L, so that the input port 2
The hydraulic pressure of 0L is transmitted as it is to the second output port 30L, and the left front wheel and right rear wheel are operated by the same brake hydraulic pressure in the wheel cylinder 22L.
and 28R. Output port 5
Regarding the hydraulic pressure No. 4, the right front wheel and the left rear wheel are braked by the wheel cylinders 22R and 28L which are operated by the same brake hydraulic pressure.

When the pedal 50 is depressed even more strongly from this state, the braking fluid pressure generated in the master cylinder 48 is directly transmitted to the front wheel cylinders 22L, 22R, while the brake fluid pressure generated in the master cylinder 48 is directly transmitted to the rear wheel cylinders 28L, 28R. Since the brake fluid pressure reduced by the P valve 2 is transmitted, the rate of increase in the braking force applied to the rear wheels is smaller than that to the front wheels. That is, the brake fluid pressure at the second output ports 30L, 30R is
The biasing force of the coiled springs 34L and 34R is greater than the force pushing down the valve piston 1.
When the force becomes larger than the force pushing up the valve bodies 10L, 12R, the valve pistons 12L, 12R move downward against the urging force, and the valve bodies 10L, 10R move downward.
are seated on the valve seats 26L, 26R and the input ports 20L, 20R and the second output ports 30L, 3
0R is closed. The brake fluid pressure at this point is the corner fluid pressure. After this, the second output ports 30L, 30R and the input ports 20L, 20
Valve piston 12L, 1 based on brake fluid pressure of R
Pressing force to 2R and coiled spring 34L, 3
Valve piston 12L, 1 based on the biasing force of 4R
Valve body 10 so that the upward force to 2R is equal to
L and 10R open and close slightly to perform a known hydraulic pressure control action.

At this time, if both valve pistons 12L and 12R move simultaneously, the connecting rod 42 does not rotate at all.
However, slight variations in the urging force of the coiled springs 34L, 34R and the outer diameters of the valve pistons 12L, 12R, etc.
Due to variations in the sliding resistance of 2R, one of the valve pistons 12L and 12R may start moving before the other. Now, if the valve piston 12L starts moving first and the valve piston 12R is in a stationary state, the connecting rod 42
is rotated in the counterclockwise direction in FIG. 1 about the engaging portion for the protruding end of the valve piston 12R. Then, the valve body 10L is connected to the valve seat 2.
6L, the abutting protrusion 46 on the right side in FIG. 1 of the connecting rod 42 abuts against the housing 4. That is, the valve body 10L is connected to the valve seat 26.
In order to seat at L, it is necessary that the valve piston 12R also move.

The brake fluid pressure in the valve chambers 8L and 8R further increases,
When the pushing force of the valve pistons 12L, 12R overcomes the biasing force of the coil springs 34L, 34R, the connecting rod 42 rotates further, and the valve body 10L
When the connecting rod 42 is not provided, the brake fluid pressure in the wheel cylinder 28R is increased and approaches the brake fluid pressure in the wheel cylinder 28R.
The brake fluid pressure of L is reduced almost uniformly.

The operation when a failure occurs in either piping system is as follows. For example, a conduit from the output port 54 of the master cylinder 48 to the wheel cylinder 22R of the front right wheel via the input port 20R and the first output port 24R of the P valve 2, or from the second output port 30R to the wheel cylinder 28
If a fluid leak occurs in the pipe leading to L, brake fluid pressure is not supplied from the output port 54, but brake fluid pressure is supplied from the output port 52 to the input port 20L and the left front wheel wheel cylinder 22L. Ru. When the brake fluid pressure of the second output port 30L increases, the valve piston 12L moves downward, causing the connecting rod 42 to rotate counterclockwise (in FIG. 1) about the engagement portion with the valve piston 12R. This rotation is regulated by the distance D between the abutting protrusion 46 on the right side of the connecting rod 42 (in FIG. 1) and the housing 4 disappearing and they coming into contact with each other. When the valve piston 12L is further pushed down, the connecting rod 2 is rotated about the corresponding contact point against the biasing force of the coiled springs 34L and 34R, and the valve piston 12L is further depressed.
L is seated on the valve seat 26L, and the brake fluid pressure of the second output port 30L is adjusted. At this point, the contact point and the valve piston 12R
The distance between the contact point and the valve piston 12 is a.
If the distance from L is b, then the valve piston 12L
The pushing up force is (1+a/b) times the normal one, and correspondingly, the corner point hydraulic pressure of the brake hydraulic pressure generated at the second output port 30 is about (1+a/b) times as much as the normal force. This is extremely convenient for maintaining balance during braking. That is, the connecting rod 42 has its abutting protrusion 4
6 and the housing 4 as a fulcrum, and the engagement portion between the valve pistons 12L, 12R and their intermediate portions (near the through hole 44) as a power point, the lever transmits the biasing force of the coiled spring 34R to the valve piston 12L. is formed. Incidentally, since the present embodiment is configured symmetrically, the above-mentioned operation is performed in the same manner on the opposite side.

In this way, according to this embodiment, the valve pistons 12L and 12R may
Even if there is a difference between the valve pistons 12L and 12R,
are connected by a connecting rod 42, and the connecting rod 42
The protrusions 46 on both ends of the housing 4 have a small distance D
Since the two systems are placed facing each other with a gap between them, the hydraulic pressure control characteristics of both systems can be made to be approximately the same when the two systems are normal, and even if a failure occurs in one piping system, the breakpoint of the other piping system can be maintained. Since the hydraulic pressure is increased, the braking force at the rear wheels increases and the balance of the vehicle is maintained when braking.

Next, another embodiment of the present invention will be described. It should be noted that the present invention differs from the previous embodiment in the method of engagement between the connecting rod 42 and the valve pistons 12L, 12R, and therefore a description of the other parts will be omitted.

In FIG. 2, valve pistons 12L, 1
A U-shaped notch 60 with a width sufficiently larger than the diameter of the exposed end of the 2R is formed on the inner surface of the notch 60, and the middle portion in the thickness direction of the notch 60 extends inwardly along the inner circumferential surface. A protruding ridge 62 is formed. A groove 64 is formed on the outer periphery of the exposed side end (lower end) of the valve pistons 12L, 12R on one circumference, and the exposed side end of the valve piston 12L, 12R is formed so that the protrusion 62 is fitted into this groove 64. By being pushed into the notch 60, the valve pistons 12L, 12R are engaged with the connecting rod 42. In this case, the width of the groove 64 is approximately 0.1 to 0.2 mm larger than the thickness of the protrusion 62, and the diameter of the bottom of the groove 64 is approximately 0.1 to 0.2 mm smaller than the distance between the tips of the opposing protrusions 62. Valve piston 12 on rod 42
Rotation relative to L and 12R is allowed. In the above state, as shown in FIG. 3, since the cover 6 having an inner width slightly larger than the width of the connecting rod 42 is fixed to the housing 4, the connecting rod 42 falls off from the valve pistons 12L and 12R. do not. In this way, according to this embodiment, the connecting rod 4
2 is extremely easy to assemble.

The above-mentioned embodiment is merely one embodiment of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

For example, the first output ports 24L, 24R provided in the housing 4 supply the braking fluid pressure of the output ports 52, 54 of the master cylinder 48 to the left and right front wheel cylinders 22L, 22R, so the output ports 52 , 54 directly to the wheel cylinders 22L, 22R, the first output port 24
There is no problem even if L and 24R are removed.

Further, the valve piston 12L of the above-mentioned embodiment,
The engagement between the lower end of 12R and the connecting rod 42 is achieved through a recess such as a stepped portion 38 or a groove 64 provided at the lower end, and a through hole 44 or a protrusion 6 formed in the connecting rod 42.
For example, a snap spring is provided at the lower end of the valve pistons 12L, 12R in a recess such as a groove provided on the inner peripheral surface of the notch 60 of the connecting rod 42. Of course, a ring-shaped convex portion such as the above may be engaged.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a hydraulic control valve connected to two systems of braking devices, showing an embodiment of the present invention. FIG. 2 is a perspective view illustrating an assembled state of another embodiment of the present invention. 3 is a side view, partially in section, of the embodiment of FIG. 2. FIG. 2: Hydraulic pressure control valve (P valve), 4: Housing, 12L, 12R: Valve piston, 22L,
22R, 28L, 28R: Wheel cylinder, 3
4L, 34R: Coiled spring, 42: Adjustment member (connecting rod), 48: Master cylinder, 50:
Brake operating member (brake pedal).

Claims (1)

[Claims for Utility Model Registration] Two valve pistons are disposed in a single housing in parallel with one end of each exposed outside the housing, and each valve piston uses an independent system of brake fluid. The brake fluid pressure is pushed out of the housing for a certain length by pressure and closes the on-off valves provided in the brake fluid passages of each system, thereby keeping the brake fluid pressure transmitted from the fluid pressure source to the wheel cylinders of the left and right rear wheels at a constant level. A control valve that reduces pressure at a ratio of , wherein two coil springs are fitted around the outer periphery of each valve piston in the housing and bias each valve piston toward the housing; extending in a direction perpendicular to both exposed ends of the valve pistons, the two portions of the intermediate portion being rotatable and axial in a plane including the axes of at least two valve pistons at the exposed ends of each valve piston; an adjustment member that is substantially immovably engaged with the housing and has both ends facing the housing, and the distance between both ends of the adjustment member and the housing is equal to the distance between the two ends of the adjustment member and the housing. When one of the valve pistons is pushed out of the housing while the other valve piston rotates the adjustment member around the engagement portion with respect to the one valve piston, with one of the valve pistons being pushed into the housing the most; ,
Before the opening/closing valve corresponding to the other valve piston is closed, the end of the adjusting member on the one valve piston side comes into contact with the housing, but when both valve pistons are pushed out of the housing, A hydraulic control valve for a two-system control device, characterized in that the valve is selected to have a size that does not touch each other.