JPH0537622U - Hydraulic control valve - Google Patents

Abstract

(57) [Abstract] [Purpose] When the brake fluid is returned from the input port to the master cylinder, the poppet valve is prevented from swinging due to the flow of the brake fluid, and abnormal noise due to swinging of the poppet valve is prevented. It reduces the occurrence and discomfort to the driver. [Configuration] A valve housing 31 is provided on the input port 3 side of the housing 1. A poppet valve 37 biased by a spring 41 toward the upper surface of the valve housing chamber 34 is housed in a valve housing chamber 34 formed in the valve housing 31. Annular wall 15 formed on the housing 1
This restricts the movement of the piston 2 and forms a gap between the tip of the piston 2 and the upper surface of the valve storage chamber 34.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hydraulic control valve provided in a vehicle brake device or the like.

[0002]

[Prior Art]

 Between the master cylinder and the rear wheel cylinder of the vehicle, the load moves to the front wheel side during braking and the rear wheels tend to lock, so the brake fluid pressure on the rear wheel cylinder is the master cylinder fluid pressure. Accordingly, a hydraulic pressure control valve (so-called pcv) is provided so that the pressure does not rise as it is and the pressure is lower than that of the front wheel cylinder.

A conventional structure of this type of hydraulic control valve will be described by taking the structure shown in FIG. 6 as an example. In the drawings, reference numeral 1 is a housing, reference numeral 2 is a piston housed between the input port 3 and output port 4 of the housing 1, and reference numeral 5 is a poppet valve for opening and closing a liquid passage 6 penetrating the piston 2. Reference numeral 7 denotes an elastic member that presses and urges the piston 2 toward the output port 4. The housing 1 is composed of a housing body 11 and an adapter 12 combined in series, and an input port 3 connected to a master cylinder (not shown) in the housing body 11 is connected to a wheel cylinder in the adapter 12. Each output port 4 is formed. The piston 2 is housed so as to be able to reciprocate between the ports 3 and 4 of the housing 1, and the input port 3 side has a smaller diameter and the output port 4 side has a smaller diameter with respect to the intermediate portion 13 in the longitudinal direction. It has a large-diameter stepped shape, and a large-diameter portion 14 is formed on the inner peripheral surface of the adapter 12, and an annular wall 15 is provided protruding from the inner peripheral portion of the housing body 11 near the input port 3. The small-diameter portions 16 are adapted to be in liquid-tight contact with each other and can be slid. Reference numeral 17 indicates a seal member arranged on the sliding portion. The liquid passage 6 formed in the piston 2 is also gradually reduced in diameter from the output port 4 side toward the input port 3 side. A flange 18 is provided on the outer peripheral portion near the large diameter portion 14 of the piston 2, and a stopper 19 at the rear end of the adapter 12 protruding into the housing 1 is provided with a front end position of the stroke of the piston 2 ( The elastic member 7 is provided between the flange 18 and the annular wall 15 of the housing body 11 at the initial position).

On the other hand, the poppet valve 5 is movably attached to the input port 3 of the housing 1 and is urged by a spring (elastic member) 21 against the annular wall 15 of the housing body 11 in a contact state. Then, the piston 2 is retracted so that the tip of the small diameter portion 16 contacts the seat surface 5a to close the liquid passage 6, and the poppet valve 5 connects the input port 3 to the housing 1. Flow paths 23, 23 are formed. In this case, a communication chamber 24 is formed between the poppet valve 5 and the annular wall 15 and communicates with the input port 3 via the flow paths 23, 23 of the poppet valve 5, and in the initial position of the piston 2, the poppet valve is formed. A space is provided between the piston 5 and the tip of the small-diameter portion 16 of the piston 2 so that the input port 3, the communication chamber 24, and the liquid passage 6 are in communication with each other. The spring 21 is locked by a spring receiver 25 provided on the inner peripheral portion of the housing body 11. At the end of the housing body 11 on the input port 3 side, a short cylindrical cap 26 is swaged at several places on the circumference so that the flange portion 11a formed on the outer circumference of the body 11 is sandwiched. It is fixed by. The cap 26 is formed with passage holes 27, 27 and 28 which connect the master cylinder side and the input port 3 to each other. Further, the poppet valve 5 is formed with a retaining protrusion 5b protruding toward the seal member 17 and a positioning protrusion 5c on the side opposite to the retaining protrusion 5b so as to come into contact with the cap 26. ing.

As described above, the poppet valve 5 is formed with the retaining projections 5b and the positioning projections 5c. Therefore, when the hydraulic pressure control valve main body 11 is assembled to the vehicle body, when the air is released by filling the brake fluid, the input Even if the small diameter portion 16 of the piston 2 pushes up the seal member 17 when reassembling the main body 11 after disassembling and repairing the main body 11 due to negative pressure on the port 3 side, the seal member 17 is formed in the poppet valve 5. The positioned positioning projection 5c comes into contact with the cap 26 and the retaining projection 5b reliably prevents the seal member 17 from falling off.

Further, since the cap 26 is caulked on the outer periphery of the main body 11 and is less likely to generate metal dust, and since no metal dust enters the input port 3, the input of metal dust is prevented. It is possible to prevent the operation of the poppet valve 5 and the sealability of the seal member 17 from being adversely affected by the entry into the port 3. Note that reference numeral 29 in FIG. 1 denotes a seal member interposed between the housing body 11 and the adapter 12.

According to the fluid pressure control valve having the above configuration, when the fluid pressure in the master cylinder is equal to or lower than a certain value, the fluid pressure is directly transmitted to the wheel cylinder, but the pressure receiving areas at both ends of the piston 2 When the pressing force generated by the difference between the two 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 poppet valve 5, and thereafter the master cylinder is closed. The hydraulic pressure of the wheel acts on the wheel cylinder while being limited at a fixed rate.

[0008]

[Problems to be solved by the device]

 In the fluid pressure control valve having the above structure, when the brake fluid pressure is released, the tip of the small diameter portion 16 of the piston 2 contacts the poppet valve 5 and the fluid passage 6 is closed, and the piston 2 and the poppet valve are closed. 5 is moved toward the input port 3 and the output side is also depressurized by the volume change on the output port 4 side. Then, in the full stroke state in which the rear end of the intermediate portion 13 of the piston 2 is in contact with the annular wall 15 of the housing main body 11, the state where the output side is not depressurized slightly occurs.

After that, the poppet valve 5 is moved by the differential pressure between the output side hydraulic pressure and the input side hydraulic pressure in the liquid passage 6 that acts on the seat surface 5 a of the poppet valve 5, so that the liquid passage 6 is opened and closed. Restart decompression. That is, the brake fluid is sent from the fluid passage 6 of the piston 2 to the communication chamber 24, passes through the flow paths 23, 23 of the poppet valve 5 and the outer circumference of the poppet valve 5 and the annular wall 15 and reaches the cap 26. The fluid pressure on the output side is reduced by returning to the master cylinder from the formed passage holes 27, 27 and 28.

By the way, when the brake fluid passes through the flow paths 23, 23 of the poppet valve 5 and the outer circumference of the poppet valve 5 and the annular wall 15 and is returned to the input port 3, an abnormal noise is generated, There is a problem that it gives a driver an unpleasant feeling. When the cause of this abnormal noise was examined, it was thought that one cause was that the poppet valve 5 rocked due to the flow of the brake fluid returned to the input port 3.

In this case, like the hydraulic pressure control valve shown in FIG. 1 of Japanese Patent Laid-Open No. 62-299459, a poppet valve is movably accommodated in a bracket, so that the influence of the flow of the brake liquid is affected. However, even with a hydraulic control valve having such a structure, when the differential pressure piston moves and the tip of the bracket comes into contact with the valve seat, the passage of the stepped piston The brake fluid that is returned from the valve and moves the poppet valve flows into the bracket that houses the poppet valve (the inside of the bracket serves as a flow path), causing the poppet valve to oscillate and produce abnormal noise. There was a problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hydraulic control valve that can reduce the generation of abnormal noise when releasing the brake hydraulic pressure.

[0013]

[Means for Solving the Problems]

 A hydraulic control valve of the present invention comprises a housing having an input port and an output port, a piston which is reciprocally supported in the housing and has a large diameter on the output port side, and the piston which extends in the output port direction. An elastic member for urging the stopper, a stopper formed in the housing to restrict movement of the piston in the direction of the input port, a liquid passage formed in the piston and communicating with both ports, In a hydraulic control valve having a valve body for closing the input port side of the passage, a housing chamber for movably housing the valve body and an outer peripheral side of the housing chamber are provided on the input port side of the housing. A valve housing having a formed flow path is provided, and between the end portion of the piston on the input port side and the valve housing, the stopper of the piston is provided. At restricted state of movement by, it is characterized by comprising formed passages brake fluid consisting passable clearance.

[0014]

[Action]

 According to the fluid pressure control valve of the present invention, the brake fluid passes through the flow passage formed by the gap formed between the end portion of the piston on the input port side and the valve housing, and the valve housing of the valve housing is accommodated. Since the brake fluid in the room serves as a cushioning material for the valve element, the vibration caused by the flow of the brake fluid in the valve element and the vibration generated during movement are greatly reduced, and It is possible to reduce the generation of abnormal noise.

[0015]

【Example】

 An embodiment of the hydraulic control valve of the present invention will be described below with reference to FIGS. 1 and 2. The same structural parts as those of the conventional example are designated by the same reference numerals, and the description thereof will be omitted. As shown in the figure, the hydraulic pressure control valve of this embodiment is provided with a valve housing 31 on the input port 3 side. The valve housing 31 is supported such that an outer peripheral edge portion 32 thereof is sandwiched by a flange portion 11a of the housing main body 11 and a cap 33 which is formed in a short cylindrical shape and is attached to the flange portion 11a by fastening at several places. ing. A valve housing chamber 34 is formed in the valve housing 31, and is formed between the valve housing chamber 34 and the outer peripheral edge portion 32 so as to communicate with a flow path 35 formed in the cap 33. A flow path 36 is provided. That is, the flow path 36 of the valve housing 31 and the flow path 35 of the cap 33 connect the input port 3 and the master cylinder (not shown).

A poppet valve (valve body) 37 is provided in the valve housing chamber 34 of the valve housing 31. The poppet valve 37 is formed with a projection 38 having a seat surface 38a on the piston 2 side, and the projection 38 is inserted into a hole 39a formed in an upper surface 39 of the valve housing chamber 34. ing. A spring 41 engaged with a recess 37b formed on the master cylinder side of the poppet valve 37 is provided between the poppet valve 37 and the cap 33, and the poppet is urged by the spring 41. The valve 37 is constantly urged toward the upper surface portion 39 of the valve storage chamber 34. Further, a gap is formed between the upper surface portion 39 of the valve housing chamber 34 of the valve housing 31 and the end portion of the piston 2 on the input port 3 side even in the full stroke state of the piston 2. That is, the rear end of the intermediate portion 13 of the piston 2 is brought into contact with the annular wall (stopper) 15 to restrict the movement of the piston 2 to the input port 3, and the end of the piston 2 on the input port 3 side. A gap is maintained between the above portion and the upper surface portion 39 of the valve storage chamber 34. Reference numeral 42 is an air vent hole formed for venting air in the valve housing chamber 34 when the hydraulic pressure control valve body is assembled and the brake fluid is filled.

In the fluid pressure control valve configured as described above, the piston 2 is normally arranged at the initial position where the flange 18 contacts the stopper 19 in the housing 1 by the urging force of the elastic member 7 as shown in FIG. As a result, a space is provided between the tip of the small diameter portion 16 of the piston 2 and the poppet valve 37, so that the liquid passage 6 is opened. Further, during braking, as shown in FIG. 3, the brake fluid flows from the master cylinder through the flow passages 35 and 36 into the input port 3, and further passes between the piston 2 and the valve housing 31 to pass the fluid passage. It is led from the output port 4 to the wheel cylinder via 6 In this case, the hydraulic pressure acts on both ends of the piston 2, and the difference in the 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 is Assuming that the cross-sectional area of A2 is A2 and the minimum step area of the liquid passage 6 is A3, it will be pressed toward the input port 3 by (A1-A3)-(A2-A3)), and the pressing force (input liquid When the pressure is p, the piston 2 is held in the initial position while p · (A1-A2)) is smaller than the urging force F of the elastic member 7, but when the pressing force is larger than the urging force, the piston 2 inputs. By moving toward the port 3 and the tip of the small diameter portion 16 contacting the seat surface 38a of the poppet valve 37, the liquid passage 6 is closed, and the ports 3 and 4 are temporarily shut off from each other.

Until the hydraulic passage 6 is closed, the input hydraulic pressure from the master cylinder is transmitted to the wheel cylinder as it is, and the same hydraulic pressure is applied to both the rear and front wheel cylinders (Op0 in FIG. 4). while). After the fluid passage 6 is once closed, the piston 2 reciprocates so as to balance the pressing force with the increase in the input fluid pressure, and the opening and closing of the fluid passage 6 is repeated. It rises (between p0 and A in FIG. 4).

On the other hand, in the depressurization process for releasing the brake fluid pressure, the pressure is reduced in comparison with the depressurization of the master cylinder, whereas in the rear wheel cylinder, the pressure is reduced stepwise. That is, when the hydraulic pressure on the input side is slightly reduced (between A and B in FIG. 4) and the balance with the pressing force is lost, the pressing force causes the piston 2 to move toward the input port 3. As a result, the tip of the small-diameter portion 16 of the piston 2 contacts the seat surface 38a of the poppet valve 37, and the piston 2 and the poppet valve 37 move toward the input port 3 side (downward direction in FIG. 1) with the liquid passage 6 closed. (2) and the output side is depressurized by the volume change on the output port 4 side (between B and C in FIG. 4). Then, in the full stroke state shown in FIG. 5 in which the rear end of the intermediate portion 13 of the piston 2 is in contact with the annular wall 15 of the housing body 11, there is a slight state in which the output side is not depressurized (between C and D in FIG. 4).

After that, the poppet valve 37 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 38 a of the poppet valve 37 so that the liquid passage 6 is opened and closed. Then, the pressure reduction is restarted (between D and E in FIG. 4). That is, the brake fluid passes from the fluid passage 6 of the piston 2 between the end portion of the piston 2 on the side of the input port 3 and the upper surface portion 39 of the valve accommodating chamber 34, and further passes through the flow passages 36, 35. It is returned to the cylinder and the hydraulic pressure on the output side is reduced. Here, the brake fluid sent out from the fluid passage 6 flows radially outward in the gap between the end portion of the piston 2 on the input port 3 side and the upper surface portion 39 of the valve storage chamber 34, and further, the flow passage 36. , 35 to be returned to the master cylinder, the poppet valve 37 is not affected by the flow of the brake fluid returned to the master cylinder. That is, the poppet valve 37 is prevented from swinging due to the flow of the brake fluid. Further, when the poppet valve 37 moves, the brake fluid in the valve storage chamber 34 serves as a cushioning material, and the vibration generated when the poppet valve 37 moves is absorbed. After that, 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 (between E and F in FIG. 4).

As described above, according to the hydraulic control valve of the present embodiment, the brake fluid returned to the master cylinder is generated between the end portion of the piston 2 on the input port 3 side and the upper surface portion 39 of the valve storage chamber 34. Since the brake fluid in the valve housing chamber 34 of the valve housing 31 serves as a cushioning material for the poppet valve 37, the poppet valve 37 is returned as well as passing through the gap formed therebetween. Vibration caused by the flow of the brake fluid and vibration generated during movement can be significantly reduced, and abnormal noise generated by the oscillation and vibration of the poppet valve 37 can be reduced. Therefore, it is possible to reduce the discomfort to the driver due to the generation of abnormal noise. In order to obtain a good cushioning effect by the brake fluid in the valve storage chamber 34, the annular gap between the hole 39a of the valve storage chamber 34 and the projection 38 of the poppet valve 37 should be made small, and the air bleed should be removed. The diameter of the hole 42 is also reduced so that the formation position of the hole 42 does not appear below the poppet valve 37 when it is in contact with the upper surface portion 39 of the poppet valve 37, and the piston 2 is in the full stroke state. The position where it is covered by the side surface of the poppet valve 37 is preferable. The specific structure of the hydraulic pressure control valve of the above embodiment is not limited to the embodiment.

[0022]

[Effect of the device]

 As described above, according to the hydraulic control valve of the present invention, the following effects can be obtained. The brake fluid passes through the gap formed between the end of the piston on the input port side and the valve housing, and the brake fluid in the valve housing chamber of the valve housing serves as a cushioning material for the valve element. Therefore, it is possible to greatly reduce the vibration generated when the valve body swings and moves due to the flow of the brake fluid, and it is possible to reduce the abnormal noise generated by the swinging and vibration of the valve body. Therefore, discomfort to the driver due to the generation of abnormal noise can be reduced.

[Brief description of drawings]

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

FIG. 2 is a plan view of a valve housing accommodating a poppet valve for explaining the shape of the valve housing according to the embodiment of the present invention.

FIG. 3 is a sectional view of a part of the hydraulic control valve for explaining the operation of the hydraulic control valve according to the embodiment of the present invention.

FIG. 4 is a hydraulic pressure characteristic diagram showing a change in hydraulic pressure between a rear wheel cylinder to which a hydraulic pressure control valve is connected and a master cylinder.

FIG. 5 is a sectional view of a part of the hydraulic control valve for explaining the operation of the hydraulic control valve of the embodiment of the present invention.

FIG. 6 is a cross-sectional view of a hydraulic control valve for explaining the structure of a conventional hydraulic control valve.

[Explanation of symbols]

 1 Housing 2 Piston (Stepped Piston) 3 Input Port 4 Output Port 6 Liquid Passage 7 Elastic Member 15 Annular Wall (Stopper) 31 Valve Housing 34 Storage Chamber (Valve Storage Chamber) 36 Flow Path 37 Poppet Valve (Valve Disc)

Claims (1)

[Scope of utility model registration request] 1. A housing having an input port and an output port, a piston reciprocally supported in the housing and having a large diameter on the output port side, and urging the piston toward the output port. An elastic member, a stopper formed in the housing for restricting movement of the piston in the direction of the input port, a liquid passage formed in the piston and communicating with both ports, and the liquid flow passage on the input port side. In a hydraulic control valve having a valve body for closing the valve, the housing has an accommodating chamber for accommodating the valve element on the input port side, and a flow path formed on an outer peripheral side of the accommodating chamber. A valve housing is provided, and between the end portion of the piston on the input port side and the valve housing, the movement of the piston by the stopper is regulated. State in the liquid pressure control valve characterized by comprising formed passages brake fluid consisting passable clearance.