JP2886703B2 - Hydraulic pressure control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pressure control valve provided in a master cylinder or the like of a vehicle brake device.

[0002]

2. Description of the Related Art In general, when a running vehicle is braked, the load moves to the front wheels and the rear wheels are likely to be locked. For this reason, conventionally, as shown in FIG. 8, a master cylinder M that sends brake fluid stored in a reservoir tank R to a front wheel cylinder and a rear wheel cylinder is provided between the rear cylinder and the rear wheel cylinder. So that the hydraulic pressure of the brake fluid sent out to the
A hydraulic pressure control valve A (so-called pcv) for lowering the pressure than the front wheel cylinder is provided.

The structure of the hydraulic pressure control valve A will be described with reference to FIG. In the drawings, reference numeral 1 denotes a housing, reference numeral 2 denotes a piston housed between an input port 3 and an output port 4 of the housing 1, reference numeral 5 denotes a valve body for opening and closing a liquid passage 6 penetrated by the piston 2, and reference numeral. 7 is an elastic member which presses and biases the piston 2 toward the output port 4,
Reference numeral 8 denotes the valve element 5 which is moved by a convex key 10 (see FIG. 1) provided on a piston 9 in the master cylinder M.
5 shows a slider that releases the function of the hydraulic pressure control valve A by inclining the hydraulic pressure control valve A. The housing 1 is formed by combining a housing body 11 and an adapter 12 in series, and an input port 3 connected to the mounting portion Ma of the master cylinder M is connected to an output port connected to the adapter 12 to a wheel cylinder. Ports 4 are respectively formed. Further, the piston 2 is connected to the housing 1
Are stored so as to be able to reciprocate between the two ports 3 and 4, and the input port 3 with respect to the intermediate portion 13 in the longitudinal direction.
The adapter 12 has a stepped shape with a small diameter on the side and a large diameter on the output port 4 side.
However, the small-diameter portions 16 are slid in contact with the annular wall 15 projecting from the inner peripheral portion near the input port 3 of the housing body 11 in a liquid-tight manner. Symbol 17
Indicates a seal member provided on the sliding portion. The liquid passage 6 formed in the piston 2 is also connected to the output port 4.
The diameter is gradually reduced from the side toward the input port 3 side. A flange 18 is provided on the outer peripheral portion of the piston 2 in the vicinity of the large-diameter portion 14, and a front end position of the piston 2 stroke (initial The elastic member 7 is provided between the flange 18 and the annular wall 15 of the housing body 11.

On the other hand, the valve element 5 is provided so as to be movable to the input port 3 of the housing 1 and urged against the annular wall 15 of the housing body 11 by a spring (elastic member) 21 so as to abut. The piston 2 retreats and the small diameter portion 16
The liquid passage 6 is closed by the front end contacting the seat surface 5a. The valve element 5 is provided with a notch 22 and a flow path 23 that allow the input port 3 to communicate with the inside of the housing 1.
Are formed. In this case, the valve element 5 and the annular wall 15
A communication chamber 24 communicating with the input port 3 through the notch 22 of the valve body 5 and the flow path 23 is formed between the valve body 5 and the small diameter portion 16 of the piston 2 at the initial position of the piston 2.
The input port 3, the communication chamber 24, and the liquid passage 6 are in communication with each other with an interval provided between the distal end portions. The spring 21 is locked by a spring receiver 25 projecting from an inner peripheral portion of the housing body 11.

The slider 8 has protrusions 31, 32 in the direction of the master cylinder M and in the direction of the valve element 5, respectively.
Is formed, and a spring member 8a that applies an urging force to the shaft portion 36 to always position the shaft portion 36 at the center.
When the shaft 36 is slid by the convex key 10 of the master cylinder M, the spring 8a is guided to guide the shaft 3
6 comprises a guide portion 37 for sliding the slider 6 horizontally, and a mounting cylinder portion 38 for attaching the slider 8 to the input port 3 side of the hydraulic pressure control valve main body 1. The shaft portion 36, the spring member 8a, and the guide portion 37, the mounting cylinder 38 is integrated. Then, the projection 3 on the valve body 5 side of the shaft portion 36
2 is engaged with a concave portion 5 b formed in the valve element 5, and a projection 31 provided on the master cylinder M side is inserted into a brake fluid passage 34 formed on a cylinder wall 33 of the master cylinder M. Pressurized chamber 35 of master cylinder M
It is projected to.

According to the hydraulic pressure control valve A having the above structure, when the hydraulic pressure in the pressurizing chamber 35 of the master cylinder M is equal to or lower than a predetermined value, the hydraulic pressure is transmitted to the wheel cylinder as it is. When the pressing force generated by the difference between the pressure receiving areas at both ends of the elastic member 7 becomes larger than the urging force of the elastic member 7, the piston 2 is moved to the input port 3 side, and the liquid passage 6 is closed by the valve body 5, and thereafter, The hydraulic pressure of the master cylinder M acts on the wheel cylinder while being restricted at a fixed ratio. In the event that the front wheel cylinder fails, the piston 9 of the master cylinder M moves in the direction of arrow a in FIG.
Move until it touches. As a result, the convex key 10 of the piston 9 is engaged with the projection 31 and the slider 8 is moved in the direction of arrow B in FIG. Is tilted so that the control of the brake fluid pressure by the valve element 5 is released.

[0007]

In the hydraulic pressure control valve A having the above structure, when the brake hydraulic pressure is released, the piston 2
The piston 2 and the valve body 5 are moved toward the input port 3 with the tip of the small diameter portion 16 abutting on the valve body 5 and the liquid passage 6 is closed, and the output side is also changed due to a change in volume on the output port 4 side. The pressure is reduced. In the full stroke state where the rear end of the intermediate portion 13 of the piston 2 abuts against the annular wall 15 of the housing body 11, a state in which the output side is not depressurized slightly occurs. Thereafter, the valve element 5 is moved by the differential pressure between the output side hydraulic pressure and the input side hydraulic pressure in the liquid passage 6 acting on the seat surface 5a of the valve body 5, and the liquid passage 6 is opened and closed. I do. That is, the brake fluid is sent from the fluid passage 6 of the piston 2 to the communication chamber 24, and the notch 22 of the valve 5
3 and between the outer periphery of the valve element 5 and the annular wall 15, the brake fluid is returned from the brake fluid passage 34 formed in the cylinder wall 33 of the master cylinder M to the pressurizing chamber 35 of the master cylinder M,
The hydraulic pressure on the output side is reduced.

By the way, the brake fluid is supplied to the notch 2 of the valve body 5.
2. When returning to the input port 3 after passing between the outer periphery of the flow path 23 and the valve body 5 and the annular wall 15, there is a problem that an unusual sound is generated and gives a discomfort to the driver. Was. After examining the cause of this abnormal noise, one of the causes was
By the flow of the brake fluid returning to the input port 3, the valve body 5
Was thought to be caused by rocking. In particular, since the valve body 5 side of the fluid passage 6 of the piston 2 has a seat surface, it is preferable that the fluid passage 6 has a small area in order to reduce the size of the fluid pressure control valve body. It is also necessary to provide a throttle in the path between the master cylinder M and the wheel cylinder for the purpose of or for twice-braking, so that the liquid passage 6 also needs to have a small area. I have. However, when the fluid passage 6 has a small area, the valve body 5 is easily affected by the flow of the brake fluid returned from the fluid passage 6, and noise is likely to be generated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a hydraulic pressure control valve capable of reducing generation of abnormal noise when releasing brake hydraulic pressure.

[0010]

A hydraulic pressure control valve according to the present invention is provided between an input port of a cylinder attached to a master cylinder and an output port of a cylinder to which a wheel cylinder is connected, with respect to the input port. A stepped piston having a large diameter on the output port side is housed in a state where the stepped piston is reciprocally movable between the two ports and is pressed and biased toward the output port by an elastic member. A communicating liquid passage is provided in a penetrating state, and a valve body capable of closing the liquid passage between the input port of the housing and the tip of the small diameter portion of the piston is provided, and formed on a piston provided on the master cylinder. The liquid pressure control valve is provided with a slider that slides by engagement of the convex key that is engaged to incline the valve body to open the liquid passage. Wherein the slider is provided with a check valve opened by the hydraulic pressure of the brake fluid sent from the master cylinder, and a throttle passage through which the brake fluid returned from the fluid passage to the master cylinder passes. It is characterized by.

[0011]

According to the hydraulic pressure control valve of the present invention, during braking,
When the check valve provided on the slider is opened by the flow of the brake fluid from the master cylinder in the piston direction, the brake fluid is satisfactorily fed. When the brake is released, the flow rate of the brake fluid is reduced by passing the brake fluid returned from the fluid passage formed in the piston to the input port through the throttle passage provided in the slider. Therefore, the swing of the valve body due to the flow of the returned brake fluid can be weakened, whereby the generation of abnormal noise due to the swing of the valve body can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the hydraulic control valve of the present invention will be described below with reference to the drawings. The same components as those of the conventional example are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 1, on the input port 3 side of the hydraulic control valve A1 of the present invention, a valve plate 41 is provided between the slider wall 8 and the cylinder wall 33 of the master cylinder M to which the hydraulic control valve A1 is attached. Is provided. A fitting hole 42 is formed at the center of the valve plate 41, and the protrusion 31 of the slider 8 is slidably inserted therethrough.

An elastic body 43 made of, for example, a wave washer is provided between the valve plate 41 and the slider 8, and the urging force of the elastic body 43 keeps the valve plate 41 constantly in the cylinder wall. 33 abuts on the cylinder wall 33
Is closed. The valve plate 41 is connected to the pressurizing chamber 35 of the master cylinder M.
When the brake oil flows into the input port 3 of the hydraulic pressure control valve A1 from the cylinder wall 33, it moves in a direction away from the cylinder wall 33 against the urging force of the elastic body 43 to open the brake fluid passage 34. Has become. That is, the cylinder wall 33 is provided on the input port 3 side of the hydraulic pressure control valve A1.
Is a valve seat, and a check valve that opens and closes the brake fluid passage 34 when the valve plate 41 contacts and separates from the cylinder wall 33 is configured. The valve plate 41 has an orifice flow path (throttle flow path) 44 at a position facing the brake fluid path 34.
Are formed. The orifice flow path 44 has a smaller area than the liquid passage 6 formed in the piston 2, and has a greater throttle effect than the liquid passage 6.

In the hydraulic pressure control valve A1 configured as described above, the piston 2 is arranged at an initial position where the flange 18 abuts the stopper 19 in the housing 1 by the urging force of the elastic member 7 at all times. Small diameter part 1 of piston 2
6 The space between the tip and the valve element 5 is made clear,
The liquid passage 6 is opened. Also, when braking
Brake fluid is supplied from the pressurizing chamber 35 of the master cylinder M to the input port 3 through the brake fluid passage 34. Here, a part of the brake fluid is supplied to the input port 3 through an orifice flow passage 44 formed in the valve plate 41. The orifice flow passage 44 has a small cross-sectional area. Accordingly, the pressure of the brake fluid acts on the valve plate 41 closing the brake fluid passage 34. Thereby, the valve plate 41 moves in a direction away from the cylinder wall 33 as shown in FIG. 2 against the urging force of the elastic body 43, and the brake fluid passage 34 is opened.

Thus, most of the brake fluid is supplied to the valve plate 41.
To the input port 3 side. Then, the brake fluid is supplied into the communication chamber 24 through the notch 22 and the flow path 23 of the valve body 5, and is guided from the output port 4 to the wheel cylinder via the fluid passage 6 of the piston 2. In this case, the hydraulic pressure acts on both ends of the piston 2, and a difference in pressure receiving area between the small diameter portion 16 and the large diameter portion 14 (the cross-sectional area of the large diameter portion 14 including the liquid passage 6 is A1 and the small diameter portion 16 Let A2 be the cross-sectional area and A3 be the minimum step area of the liquid passage 6.
(A1-A3)-(A2-A3)) and input port 3
The piston 2 is held at the initial position while the pressing force (p. (A1-A2) where p is the input hydraulic pressure) is smaller than the urging force F of the elastic member 7. However, when the pressing force exceeds the biasing force, the piston 2
Moves toward the input port 3 and the tip of the small-diameter portion 16 abuts on the valve body 5 to close the liquid passage 6, thereby temporarily closing the ports 3 and 4.

Until the liquid passage 6 is closed, the input hydraulic pressure from the master cylinder M is directly transmitted to the wheel cylinders, and the same hydraulic pressure acts on both the rear and front wheel cylinders. After the liquid passage 6 is once closed, the piston 2 reciprocates so as to balance the pressing force against the increase in the input hydraulic pressure, and the opening and closing of the liquid passage 6 is repeated, and the output hydraulic pressure is gradually increased. Also rises.

On the other hand, in the pressure reduction step of releasing the brake fluid pressure, the pressure is reduced in proportion to the pressure reduction of the master cylinder M, whereas the pressure is reduced stepwise in the rear wheel cylinder. That is, when the hydraulic pressure on the input side slightly decreases and the balance with the pressing force is lost, the piston 2 moves toward the input port 3 by the pressing force. Accordingly, the piston 2 and the valve body 5 are moved toward the input port 3 in a state where the distal end of the small diameter portion 16 of the piston 2 comes into contact with the valve body 5 and the liquid passage 6 is closed, and the volume on the output port 4 side is The output is also depressurized by the change. Then, in the full stroke state shown in FIG. 4 in which the rear end of the intermediate portion 13 of the piston 2 abuts against the annular wall 15 of the housing body 11, a state in which the output side is not depressurized slightly occurs.

Thereafter, the valve element 5 is moved by the pressure difference between the output side hydraulic pressure and the input side hydraulic pressure in the liquid path 6 acting on the seat surface 5a of the valve element 5 to open and close the liquid path 6. Resume decompression. That is, the brake fluid is supplied to the fluid passage 6 of the piston 2.
From the valve body 5, passes through the notch 22 of the valve element 5, the flow path 23, and the space between the outer periphery of the valve element 5 and the annular wall 15, and returns to the input port 3. Further, the valve plate 41 is made of an elastic material 4.
The brake fluid is moved in the direction of the cylinder wall 33 by the urging force of 3 and is brought into contact with the cylinder wall 33 so that the brake fluid returned to the input port 3 passes only through the orifice flow passage 44 formed in the valve plate 41. Then, the fluid is gradually returned to the pressurizing chamber 35 of the master cylinder M, and the hydraulic pressure on the output side is reduced. Thereafter, when the pressing force acting on the piston 2 becomes smaller than the urging force of the elastic member 7, the urging force pushes the piston 2 back to the initial position at once.

If the front brake fails, the piston 9 of the master cylinder M is moved in the direction of arrow a in FIG. 1 until the end 9a of the piston 9 comes into contact with the lower portion Ma. . As a result, the convex key 10 provided on the piston 9 engages with the projection 31 of the slider 8 and moves the slider 8 in the direction of arrow B in the figure. This allows
The valve element 5 engaged with the other protrusion 32 of the slider 8
Is tilted as shown in FIG. 4 to be in a tilted state. As a result, the opening and closing operation of the liquid passage 6 of the piston 2 by the valve element 5 is not performed. That is, the control of the hydraulic pressure by the hydraulic pressure control valve A1 is released, and the brake fluid sent from the pressurizing chamber 35 is supplied to the rear wheel cylinder without controlling the hydraulic pressure.

As described above, according to the hydraulic pressure control valve A1 of this embodiment, the notch 22 of the valve body 5, the flow path 2
The brake fluid that passes between the outer circumference of the valve body 3 and the valve body 5 and the annular wall 15 and returns to the master cylinder M passes only through the orifice passage 44 formed in the valve plate 41,
Its flow velocity is reduced. Thereby, the master cylinder M
Swing of the valve body 5 due to the brake fluid returned to the
The generation of abnormal noise due to the swing of the valve body 5 can be reduced. Therefore, discomfort to the driver due to the generation of abnormal noise can be reduced.

The valve plate 41 is always in contact with the cylinder wall 33 of the master cylinder M due to the urging force of the elastic body 43. The brake fluid is moved in a direction away from the cylinder wall 33 against the urging force of the elastic body 43 by the flow, and the brake fluid sent from the brake fluid passage 34 wraps around the outer peripheral side of the valve plate 41. It is possible to keep the supply of the brake fluid from the cylinder M to the input port 3 favorable,
Deterioration of the responsiveness of the brake operation can be prevented.
The valve plate 41 has an orifice passage 4 which is always open.
Since the pressure control valve 4 is formed, there is no pressure difference between the master cylinder M side and the input port 3 side, and a hydraulic pressure control valve free from dragging or the like can be obtained.

The location of the orifice flow path 44 formed in the valve plate 41 of the above embodiment is not limited to the embodiment. For example, as shown in FIG. A slight gap may be formed between the fitting hole 42 and the protrusion 31 of the slider 8 fitted in the fitting hole 42, and this gap may be used as the orifice flow path 44.

In the above embodiment, the brake fluid passage 34 of the cylinder wall 33 is opened and closed by the contact and separation of the valve plate 41 with the cylinder wall 33 in accordance with the brake fluid pressure. The body 41 itself is connected to the brake fluid passage 3
4 is formed from a material which can be elastically deformed by the brake fluid flowing into the valve body 4.
The opening and closing of the brake fluid passage 34 may be performed. Further, in the above-described embodiment, the cylinder wall 33 is used as a valve seat constituting the check valve. However, the check valve may be constituted by another member. Further, the specific structure of the hydraulic pressure control valve is not limited to the embodiment.

In the above embodiment, the slider 8 is provided with the valve plate 41 having the orifice passage 44 formed therein.
Although the movement of 1 controls the flow rate of the brake fluid, it goes without saying that the slider 8 may be used as a valve plate.

Here, an example in which the slider 8 itself is used as a valve plate will be described as a second embodiment. FIG. 6 shows a hydraulic control valve using the slider 8 itself as a valve plate. The slider 8 of this hydraulic pressure control valve has a shaft 3
6, a plate portion 39 is formed near the side portion.
An orifice flow path 44 is formed in 9 (see FIG. 7). Further, the shaft portion 36 and the plate portion 39 around the shaft portion are positioned at the center by the spring material 8a, and are supported by being slightly protruded toward the protrusion 31. However, the projecting dimensions of the shaft portion 36 and the plate portion 39 are determined when the slider 8 is attached to the input port 3 side and the hydraulic pressure control valve with the slider 8 attached is attached to the attachment portion Ma of the master cylinder M. The slider 39 is set to such an extent that the plate portion 39 of the slider 8 comes into contact with the cylinder wall 33.

When the slider 8 thus formed is attached to the input port 3 side of the hydraulic pressure control valve, and the input port 3 side of this hydraulic pressure control valve is attached to the mounting portion Ma of the master cylinder M, the slider 8 The plate portion 39 around the shaft portion 36 is urged toward the cylinder wall 33 by the spring material 8a and comes into contact with the cylinder wall 33, so that the plate portion 39 covers the brake fluid flow path 34.

According to the hydraulic pressure control valve having the above structure,
When the brake fluid flows from the master cylinder M through the brake fluid passage 34, the fluid pressure causes the plate portion 39 of the slider 8 to move toward the input port 3 against the urging force of the spring material 8a, and the brake fluid is discharged. The fluid flows from the gap formed between the plate portion 39 of the slider 8 and the cylinder wall 33 toward the hydraulic pressure control valve.

In the decompression process, the plate portion 39 of the slider 8 is moved by the urging force of the spring member 8a.
When the brake fluid is returned from the fluid passage 6 of the piston 2 due to the contact with the brake fluid, the returned brake fluid is
It is returned to the master cylinder M through only the orifice passage formed in the plate portion 39. That is, since the flow rate of the returned brake fluid is reduced, the swing of the valve body 5 due to the returned brake fluid is reduced, and the generation of abnormal noise caused by the swing of the valve body 5 can be reduced.

A groove is formed on the surface of the valve plate 41 or the plate portion 39 of the slider 8 which is in contact with the respective cylinder walls 33 to close the brake fluid passage 34 in the above embodiment.
The valve plate 41 or the plate portion 39 of the slider 8 is
The flow path formed by the groove when contacting the groove 3 may be the orifice flow path 44.

In the above-described embodiment, the valve plate 41 is urged by the elastic member 43 and the plate portion 39 of the slider 8 by the spring material 8a, so that the valve plate 41 comes into contact with the cylinder wall 33. Alternatively, by reducing the distance between the plate portion 39 of the slider 8 and the cylinder wall 33, the valve plate 41 or the plate portion 39
May be moved to open and close the brake fluid passage 34.

[0031]

As described above, according to the hydraulic pressure control valve of the present invention, the following effects can be obtained.

When the brake is released, the brake fluid returned to the input port from the fluid passage formed in the piston passes through the throttle passage provided in the slider, and the flow rate of the brake fluid is reduced. The swing of the valve body due to the flow of the brake fluid can be suppressed, and the generation of abnormal noise due to the swing of the valve body can be reduced. Thus, it is possible to prevent the driver from feeling uncomfortable due to the generation of abnormal noise. Further, when the brake is operated, the check valve provided on the slider is opened by the flow of the brake fluid in the piston direction, so that the flow of the brake fluid from the master cylinder to the input port can be kept good. .

[Brief description of the drawings]

FIG. 1 is a sectional view of a hydraulic pressure control valve illustrating a structure of a hydraulic pressure control valve according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a part of the hydraulic control valve for explaining the operation of the hydraulic control valve during braking.

FIG. 3 is a cross-sectional view of a part of the hydraulic pressure control valve for explaining an operation of the hydraulic pressure control valve when braking is released.

FIG. 4 is a cross-sectional view of a part of the hydraulic pressure control valve for explaining the operation of the hydraulic pressure control valve at the time of failure.

FIG. 5 is a cross-sectional view of a hydraulic control valve illustrating a structure of a hydraulic control valve according to another embodiment.

FIG. 6 is a partial cross-sectional view of a hydraulic pressure control valve illustrating a structure of a hydraulic pressure control valve according to a second embodiment.

FIG. 7 is a plan view of the slider for explaining the structure of the slider used in the hydraulic control valve of the second embodiment.

FIG. 8 is a cross-sectional view of the master cylinder and its surroundings for explaining the configuration of the master cylinder to which the hydraulic pressure control valve is attached.

FIG. 9 is a cross-sectional view of a hydraulic control valve illustrating a structure of a conventional hydraulic control valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Piston 3 Input port 4 Output port 5 Valve 6 Liquid passage 7 Elastic member 8 Slider 16 Small diameter part 39 Plate part (check valve) 41 Valve plate (check valve) 44 Orifice flow path (throttle flow path) M Master cylinder Ma mounting part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-266556 (JP, A) JP-A-3-246148 (JP, A) JP-A-3-258642 (JP, A) JP-A-1- 233144 (JP, A) JP-A-2-107558 (JP, U) JP-A-1-76362 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60T 8/26-8 / 30

Claims (1)

(57) [Claims] 1. A stepped piston formed between an input port of a cylinder attached to a master cylinder and an output port of a cylinder to which a wheel cylinder is connected, the output port side having a larger diameter than the input port side. Is reciprocally movable between the two ports and housed in a state of being pressed and urged toward the output port by an elastic member, and the piston is provided with a liquid passage communicating with the two ports in a penetrating state, and The input port is provided with a valve body capable of closing the liquid passage between the tip of the small-diameter portion of the piston, and slides by engaging a convex key formed on the piston provided on the master cylinder. ,
A hydraulic control valve provided with a slider that inclines the valve body to open the liquid passage, wherein the slider is provided with a check valve that is opened by the hydraulic pressure of brake fluid sent from the master cylinder. And a throttle passage through which the brake fluid returned from the fluid passage to the master cylinder passes.