JPH08318838A - Check valve - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a check valve having a cup seal fitted on the outer periphery of a support member, and an object thereof is to prevent the cup seal from falling off. [Structure] The valve seat 26 having a fluid passage 26a is press-fitted into the tip of the core 24. At the end of the fluid passage 26a,
A poppet valve 28a that is displaced by an electromagnetic force is provided to form an electromagnetic valve. In the fitting groove 26d of the valve seat 26, a cup seal 46 that allows only the flow of the working fluid from the fluid passage 44 side to the fluid passage 34 side is provided on the outer periphery of the electromagnetic valve 10. The valve seat 26 has a fitting groove 26
A through hole 26e that connects the outer periphery of d and the fluid passage 26a is provided to prevent the working fluid from flowing through the inner periphery of the cup seal 46 over the entire axial length.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a check valve, and more particularly to a check valve.
The present invention relates to a check valve in which a cup seal is fitted on the outer periphery of a support member.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Laid-Open No. 6-24308, a check valve has been known in which a cup seal is fitted around the outer circumference of an electromagnetic valve. This cup seal is
The elastic member includes a cylindrical portion that holds the outer periphery of the solenoid valve, and an umbrella portion that extends from one end of the cylindrical portion so as to be folded back to the outside of the cylindrical portion. Further, the electromagnetic valve equipped with the cup seal is inserted and arranged in the fluid passage such that the outer peripheral portion of the cap seal has a contact with the inner wall of the fluid passage.

With this structure, when fluid pressure is generated between the outer periphery of the solenoid valve and the inner wall of the fluid passage in the direction to open the umbrella portion of the cup seal, the contact between the umbrella portion and the fluid passage is strengthened, The fluid flow is cut off. On the other hand, when fluid pressure is generated between the outer periphery of the solenoid valve and the inner wall of the fluid passage in the direction to close the cap portion of the cup seal, a clearance is created between the umbrella portion and the fluid passage to allow fluid flow. To be done. In this way, according to the above configuration, it is possible to realize a check valve that allows only one-way flow between the outer circumference of the solenoid valve and the inner wall of the fluid passage.

[0004]

However, when a large fluid pressure acts on the conventional check valve in the direction to close the cap portion of the cup seal, the cap portion is closed and the diameter of the cylindrical portion is expanded. There is. When the diameter of the cylindrical portion is increased in this manner, a clearance is generated between the cylindrical portion and the outer circumference of the solenoid valve, and the fluid can flow through the clearance.

In the conventional check valve described above, the cup seal is held by the fact that the cylindrical portion grips the solenoid valve, so that a frictional force is generated between the inner periphery of the cylindrical portion and the outer periphery of the solenoid valve. Therefore, as described above, when the fluid flows between the cylindrical portion and the solenoid valve and the frictional force acting between them is reduced, the cup seal is likely to be axially displaced on the outer circumference of the solenoid valve.

Particularly, when the ambient temperature is low and the viscosity of the fluid is high, a large amount of fluid flows between the cylindrical portion of the cup seal and the solenoid valve when the liquid pressure acts in the direction of closing the umbrella portion. As it flows, a large force acts on the cup seal as the fluid flows. Therefore, when the above-mentioned conventional check valve is used in such a situation, the cup seal may drop off from the solenoid valve.

As described above, the conventional check valve described above has an advantage that a one-way valve having a simple structure can be realized between the outer circumference of the solenoid valve and the inner wall of the fluid passage.
There is a problem that the viscosity of the fluid flowing around the check valve is high, and the cup seal is likely to come off when a large fluid pressure acts on the check valve.

The present invention has been made in view of the above points, and prevents the fluid from flowing on the inner peripheral side of the cylindrical portion of the cup seal to prevent the cup seal from falling off, or the cylindrical portion. It is an object of the present invention to provide a check valve that solves the above problems by preventing the cup seal from falling off by preventing the diameter expansion of the.

[0009]

The above-mentioned object is defined in claim 1.
In a check valve formed by inserting a cup seal into a support member, the check valve is provided with a blocking means for blocking the working fluid from flowing between the cup seal and the support member. To be achieved.

Further, as described in claim 2, the above-mentioned object is, in the check valve according to claim 1, wherein the blocking means penetrates through the opening of a surface of the support member facing the cup seal. It is also achieved by a check valve with holes.

Further, as described in claim 3, the above object is to provide a check valve having a cup seal fitted in a fitting groove of a support member, wherein the cup seal has a diameter larger than a predetermined diameter. This is also achieved by a check valve having a deformation suppressing means for preventing the above.

[0012]

In the invention according to claim 1, the cup seal closes the cap portion when the fluid pressure is generated in the axial direction of the support member in the direction of closing the cap portion of the cup seal, and the working fluid is circulated. Tolerate. Further, when a fluid pressure in the direction of opening the umbrella portion of the cup seal is generated, the umbrella portion is opened to prevent the working fluid from flowing. As a result, only the flow of the working fluid in one direction is allowed on the outer periphery of the support member, and the function as the check valve is realized.

When fluid pressure acts on the cup seal, elastic deformation occurs in the cup seal, a clearance is created between the cup seal and the support member, and the working fluid may enter the clearance. In the present invention, the blocking means blocks the flow of the working fluid when the working fluid enters between the cup seal and the support member. When the flow of the working fluid that has entered between the cup seal and the support member is blocked, the frictional force acting between the cup seal and the support member is prevented from being significantly reduced. As a result, in the check valve according to the present invention, the cup seal is prevented from falling off the support member.

In the invention of claim 2, when the fluid enters between the cup seal and the support member, the fluid is
It flows into a through hole that opens in the surface of the support member that faces the cup seal. When the fluid that has entered between the cup seal and the support member flows into the through hole, the fluid is reliably blocked from flowing. Therefore, it is possible to prevent the cup seal from falling off the support member.

In the invention according to claim 3, the cup seal is arranged in a state of being fitted in the fitting groove of the support member. Further, the deformation suppressing means prevents the cup seal from being expanded to a predetermined diameter or more. If the diameter of the cup seal does not exceed the predetermined diameter, the cup seal will not fall out of the fitting groove of the support member. Therefore, in the check valve according to the present invention, the cup seal does not drop off from the support member regardless of how large the force acts on the cup seal.

[0016]

1 is a front sectional view of a solenoid valve 10 incorporating a check valve according to an embodiment of the present invention. Also, in FIG.
The expanded sectional view of the solenoid valve 10 which expanded and represented the vicinity of the check valve of a present Example is shown. Hereinafter, the configuration of the solenoid valve 10 will be described with reference to FIGS. 1 and 2.

The electromagnetic valve 10 is provided with an electromagnetic coil 14 on the outer circumference of the sleeve 12. The electromagnetic coil 14 includes a winding wire 18 formed by winding a conductive wire around the bobbin 16 a predetermined number of times. Both the bobbin 14 and the winding wire 18 are covered with a resin cover 20.

The sleeve 12 is a tubular member made of a non-magnetic material. At the open end (lower end in FIG. 1) of the sleeve 12, a skirt portion 12a having a larger opening diameter on the end side is formed. Inside the sleeve 12, the plunger 22 and the core 24 are arranged in order from the closed end side.
Has been inserted.

The plunger 22 is a member made of a magnetic material and can displace the inside of the sleeve 12 in the longitudinal direction of the sleeve. The core 24 is a member made of a magnetic material, and is press-fitted and fixed inside the sleeve 12. The core 24 has a through hole 24a in the center thereof and a taper portion 24b which engages with the skirt portion 12a of the sleeve 12 on the outer periphery thereof. The core 24 is pressed into the sleeve 12 until the tapered portion 24b contacts the skirt 12a.

The plunger 22 is press-fitted and fixed to the shaft 28 which penetrates the core 24 so that these three parts are integrated. At this time, an air gap of a predetermined length is formed between the core 24 and the plunger 22. Therefore, under the situation where the core 24 is properly assembled, the displacement of the plunger 22 in the sleeve 12 is restricted within a predetermined air gap length.

A cylindrical portion 24c is formed at one end (lower end in FIG. 1) of the core 24. This cylindrical portion 24c
A valve seat 26 is press-fitted into the core 24 from the front end side. A fluid passage 26a is provided at the center of the valve seat 26. An orifice 26b is provided at the end of the fluid passage 26a on the side communicating with the inside of the cylindrical portion 24c.

A poppet 28a provided at one end of the shaft 28 faces the opening of the orifos 26b. As shown in FIG. 2, a predetermined clearance is provided between the opening of the orifice 26b and the poppet 28a, and the orifice 26b is configured to be opened and closed by the poppet 28a. Further, a spring 29 is arranged between the valve seat 26 and the shaft 28 to generate a biasing force in a direction to separate the two. Therefore, when the electromagnetic coil 14 is not excited, a clearance is secured between the orifice 26b and the poppet 28a.

The shaft 28 has a through hole 24a in the core 24.
One end (upper end in Fig. 1) that slidably penetrates inside
It is fixed to the plunger 22 with. According to this configuration, when a predetermined current is supplied to the electromagnetic coil 14, a magnetic flux penetrating the plunger 22 and the core 24 flows, and the plunger 22 has a direction in which the air gap between the plunger 22 and the core 24 is reduced. Electromagnetic force of. This electromagnetic force is transmitted to the poppet 28a via the shaft 28 against the biasing force of the spring 29, and presses the poppet 28a toward the orifice 26b.

On the other hand, when the supply of the electric current to the electromagnetic coil 14 is stopped, the above electromagnetic force disappears, and as a result, the force pressing the poppet 28a in the direction of closing the orifice 26b also disappears. Therefore, according to the electromagnetic valve 10, by controlling the current supply to the electromagnetic coil 14, the fluid passage 2
The conduction state of 6a can be controlled.

The solenoid valve 10 described above is assembled in the housing 32 with the valve seat 26 press-fitted into the tip of the core 24. The housing 32 includes a fluid passage 34 having a diameter slightly larger than that of the cylindrical portion 24c of the core 24 and the jaw portion 26c of the valve seat 26, a fluid passage 36 having a diameter larger than that of the fluid passage 34, and a fluid. A backup ring storage space 38 having a diameter larger than that of the passage 36 and designed to open to the outside of the housing 32.
Is provided.

The core 24 houses the solenoid valve 10 in the housing 32.
When inserted in, the vicinity of the boundary between the cylindrical portion 24c and the tapered portion 24b is shaped so as to accurately close the fluid passage 36. The tapered portion 24b of the core 24 is formed so as to fit into the skirt portion 12a of the sleeve 12, and the backup ring 40 is hooked on the skirt portion 12a of the sleeve 12.

The backup ring 40 is a member having a predetermined elasticity and is caulked and fixed in a backup ring storage space 38 provided in the housing 32. According to this structure, the core 24 is pressed by the restoring force of the backup ring 40 in the direction to deepen the fitting with the housing 32. Therefore, if the solenoid valve 10 is properly assembled as shown in FIG. 1, the fluid passage 3 is provided between the fluid passage 36 and the backup ring storage space 38.
Sufficient sealing performance is ensured against the fluid pressure guided to 6.

The fluid passage 34 described above communicates with the fluid passage 42 extending below the solenoid valve 10 in FIG.
Further, the above-described fluid passage 36 is provided at a position aligned with the side surface of the cylindrical portion 24c of the core 24 when the solenoid valve 10 is assembled to the housing 32, and is located on the side of the solenoid valve 10 in FIG. It communicates with the extending fluid passage 44. On the other hand, the core 24 is provided with a fluid passage 24d that connects the internal space of the cylindrical portion 24c (the space in which the poppet 28a is housed) and the external space of the cylindrical portion 24c.

According to the above-mentioned structure, when the electric current is not supplied to the electromagnetic coil 14, the fluid passage 26a and the fluid passage 24d are brought into conduction. In this case, bidirectional flow of the working fluid is allowed between the fluid passage 42 and the fluid passage 44 through the inside of the solenoid valve 10 as shown by the solid line and the alternate long and short dash line in FIG. On the other hand, when the predetermined current is supplied to the electromagnetic coil 14, the fluid passage 26a and the fluid passage 2
4d is cut off. In this case, the working fluid cannot flow inside the solenoid valve 10, and the flow of the working fluid shown by the solid line and the alternate long and short dash line in FIG. 2 is blocked. As described above, in this embodiment, the solenoid valve 10 functions as a control valve that can arbitrarily control the conduction state between the fluid passage 40 and the fluid passage 42.

As shown in FIGS. 1 and 2, the solenoid valve 10
A cup seal 46 is fitted around the outer circumference of the valve seat 26. The cup seal 46 includes a cylindrical portion 46a that holds the valve seat 26 and an umbrella portion 46 that extends from one end of the cylindrical portion 26a so as to be folded back to the outside of the cylindrical portion 26a.
b is an elastic member. The valve seat 26 includes a fitting groove 26d having a width substantially equal to the axial length of the cylindrical portion 46a of the cup seal 46 on the lower end side of the jaw portion 26c in FIGS. 1 and 2, and the cup seal 46 is It is fitted in the fitting groove 26d.

The cup seal 46 has an end on the side where the umbrella portion 46b and the cylindrical portion 46a are integrated (hereinafter referred to as the closed end portion 4).
6c) abuts on the jaw 26c of the valve seat 26, and the end (hereinafter referred to as the open end 46d) on the side where the umbrella 46b is separated from the outer periphery of the cylindrical portion 46a is inside the fluid passage 34. The valve seat 26 is fitted so as to open at. Further, the specifications of the cup seal 46 are set such that the outermost peripheral portion of the umbrella portion 46b contacts the inner wall of the fluid passage 34 when the solenoid valve 10 is assembled to the housing 32 as shown in FIGS. Has been done.

With this structure, when a fluid pressure higher than that of the fluid passage 42 is generated on the fluid passage 44 side, the fluid pressure acts on the cup seal 46 in the direction to close the umbrella portion 46b. In this case, a clearance is generated between the inner wall of the fluid passage 34 and the outer periphery of the cup seal 46,
As shown by the chain double-dashed line in FIG. 2, the flow of the working fluid from the fluid passage 44 to the fluid passage 42 through the outside of the solenoid valve 10 is allowed. On the other hand, the fluid passage 4 is provided on the fluid passage 42 side.
When a fluid pressure higher than 4 is generated, the fluid pressure becomes
It acts on the cup seal 46 in a direction to open the umbrella portion 46b. In this case, the sealing property between the inner wall of the fluid passage 34 and the outer periphery of the cup seal 46 is enhanced, and the flow of the working fluid from the fluid passage 42 to the fluid passage 44 through the outside of the solenoid valve 10 is blocked. As described above, in the present embodiment, the cup seal 46 is provided outside the solenoid valve 10,
It functions as a check valve that allows only the flow of the working fluid from the fluid passage 44 to the fluid passage 42.

In the present embodiment, the valve seat 26 of the solenoid valve 10 is provided with two through holes 26e which are open to the fitting groove 26d and are orthogonal to each other. These through holes 26e communicate with the fluid passage 26a at the central portion of the valve seat 26. Further, as shown in FIG. 2, the through hole 26e is provided at a position deviated from the axial middle point M of the cup seal 46 by a predetermined length L toward the closed end portion 46c.

The present embodiment is characterized in that the above-mentioned through hole 26e is provided in the valve seat 26 when the cup seal 46 is fitted into the valve seat 26 to form the check valve. Hereinafter, the effect obtained by providing the through hole 26e will be described with reference to FIGS. 3 and 4.

3 and 4, the working fluid flows around the electromagnetic valve 10 having the through hole 26e and the passage when the working fluid flows through the outer periphery of the electromagnetic valve 10 'having no through hole 26e. The route when doing is shown. In the configuration shown in FIG. 3, when a higher fluid pressure is generated on the oil passage 44 side than on the oil passage 42 side, the flow of the working fluid passing through the outside of the solenoid valve 10 'is allowed as described above. When the working fluid thus circulates, a force acts on the cup seal 46 to displace the cup seal 46 toward the tip side of the valve seat 26 ', as indicated by F in FIG. On the other hand, a frictional force for restricting the axial displacement of the cup seal 46 acts on the contact portion between the cup seal 46 and the valve seat 26 'due to the gripping force of the cup seal 46 shown by M in FIG. .
Therefore, if the frictional force is maintained at a desired level, the cup seal 46 will not be largely displaced in the axial direction.

However, for example, the ambient temperature is low, the viscosity of the working fluid flowing between the fluid passages 42 and 44 is high,
In addition, when a high-pressure fluid pressure is generated from the fluid passage 44 toward the fluid passage 42, a relatively large elastic deformation occurs in the vicinity of the closed end portion 46c of the cup seal 46, and the inside of the cylindrical portion 46a of the cup seal 46a. A clearance may occur between the circumference and the outer circumference of the fitting groove 26d of the valve seat 26 '.

When a clearance is created between the inner circumference of the cylindrical portion 46a and the outer circumference of the fitting groove 26d, the working fluid enters the clearance. Since the solenoid valve 10 'shown in FIG. 3 does not have a through hole that opens into the fitting groove 26d, when the working fluid enters the inside of the cup seal 26' as shown above, it is shown by a two-dot chain line in FIG. As you can see, cup seal 46
A flow of the working fluid is generated from the fluid passage 44 toward the fluid passage 42 through the inner peripheral side of the. Then, when such a flow occurs, the cup seal 4 is caused by the lubricating action of the working fluid.
The frictional force acting between the valve 6 and the valve seat 26 is significantly reduced, and as a result, the cup seal 46 is easily removed from the fitting groove 26d.

On the other hand, as shown in FIG. 4, the valve seat 26
When the through hole 26e is provided in the valve seat 26, the working fluid that has infiltrated from the fluid passage 44 side into the inner peripheral side of the cup seal 46 flows into the through hole 26e as indicated by the chain double-dashed line in FIG. Fluid passage 2 provided in the center of the
It flows through 6a to the fluid passages 34 and 42. In this case, the working fluid does not enter between the cup seal 46 and the valve seat 26 in the region on the tip side of the valve seat 26 with respect to the through hole 26d, which is sufficient to suppress the axial displacement of the cup seal 46. A friction force can be secured.

Further, in this embodiment, the through hole 26e is provided on the closed end portion 46c side from the midpoint M of the cup seal 46 as described above. Therefore, the region where the cylindrical portion 46a is elastically deformed when the working fluid enters the inner peripheral side of the cup seal 46 is limited to the vicinity of the closed end portion 46c. In this case, since the opening end 46d side of the cup seal 46 is not greatly expanded, the cup seal 46 is fitted into the fitting groove 26.
It becomes difficult to fall over the valve seat 26 toward the tip end side of the valve seat 26.

Therefore, as in this embodiment, the cup seal 4
6 is fitted into the valve seat 26 having the through hole 26e to form the check valve, the closed end portion 46 of the cup seal 46 is formed.
It is possible to effectively prevent the cup seal 46 from falling off the valve seat 26 when a large amount of fluid pressure acts on the c side. Therefore, according to such a configuration, a more reliable check valve can be realized as compared with the case where the through hole 26e does not exist.

In the above embodiment, the valve seat 26 corresponds to the above-mentioned support member, and the through hole 26e provided in the valve seat 26 corresponds to the above-mentioned blocking means. FIG. 5 is an enlarged cross-sectional view showing a solenoid valve 50 having a built-in check valve according to a second embodiment of the present invention by enlarging the vicinity of the check valve. In addition, in FIG. 5, FIG.
Constituent parts that are the same as those in FIG.

The solenoid valve 50 has a valve seat 52 at one end (lower end in FIG. 1) of the core 24. The valve seat 52 has a fluid passage 52a penetrating its central portion.
And an orifice 52 provided at the end of the fluid passage 52a
and b. In addition, the valve seat 52 has a jaw 5
A small diameter portion 52d is provided on the tip side of 2c. Small diameter part 52
A cup seal 54, which is an essential part of the present embodiment, is fitted to d, and a ring 56 for preventing the cup seal 54 from coming off is fitted and inserted at its tip.

The cup seal 54 has a cylindrical portion 54a for holding the valve seat 52 and an umbrella portion 54 extending from one end of the cylindrical portion 54a so as to be folded back to the outside of the cylindrical portion 54a.
It is a member consisting of b. Cup seal 5 of this embodiment
4 is a cylindrical member 54 made of an inelastic member in the cylindrical portion 54a.
It is characterized in that the cylindrical member 54c is molded with an elastic material so that c is incorporated.

According to this structure, the diameter of the cylindrical portion 54a does not become larger than the outer diameter of the ring 56, and the fluid passage 4
No matter how high the fluid pressure is generated on the 4 side, the cup seal 54 does not drop off on the tip side of the valve seat 52. More specifically, in the cup seal 54 of the present embodiment, since the cylindrical member 54c prevents the cylindrical portion 54a from expanding in diameter, a comparison is made between the inner peripheral surface of the cylindrical portion 54a and the outer peripheral surface of the valve seat 52. A large surface pressure can be secured. Even if the working fluid flows between the cylindrical portion 54a and the valve seat 52, the diameter of the cylindrical portion 54a is smaller than the outer circumference of the groove formed by the ring 56 and the valve seat 52. Therefore, the cup seal 54 does not fall off the valve seat 52. Therefore, even with the configuration of the present embodiment, a highly reliable check valve can be realized as in the check valves shown in FIGS. 1 and 2.

In the above embodiment, the valve seat 52 is in the support member, the groove portion formed by the small diameter portion 52d of the valve seat 52 and the ring 56 is in the fitting groove, and the cup. The cylindrical member 54c built in the seal 54 corresponds to the above-described deformation suppressing means.

By the way, in each of the above-mentioned embodiments, the solenoid valve 1
The check valve is limited to the outer peripheral side of 0 and 50, but the present invention is not limited to such a configuration.
It can be widely applied when a check valve is constructed by inserting a cup seal on the outer periphery of a support member.

Next, an example of use of the solenoid valves 10 and 50 described above will be described. FIG. 6 shows an example of a hydraulic circuit diagram of a vehicle anti-lock brake system (hereinafter referred to as ABS). The solenoid valves 10 and 50 can be used as components of such a hydraulic circuit. In FIG. 6, the brake pedal 60 is connected to the booster 62. The booster 62 is a device that boosts the brake pedal force applied to the brake pedal 60, and is connected to the master cylinder 64. The master cylinder 64 is a tandem type master cylinder having two hydraulic pressure generating chambers therein. Fluid passages 66a and 66b are connected to the two hydraulic pressure generating chambers of the master cylinder 64, respectively. Fluid passage 6
The hydraulic circuits corresponding to the left rear wheel and the right front wheel, or the hydraulic circuits corresponding to the right front wheel and the left rear wheel, respectively communicate with the downstream sides of 6a and 66b. Since these hydraulic circuits do not differ from each other in configuration, the configuration of the circuit communicating with the fluid passage 66a will be described as a typical example thereof in the following description.

A holding solenoid 68 is provided in the fluid passage 66a.
RL and 68FR are in communication. Holding solenoid 68R
L and 68FR are two-position solenoid valves that switch between open and closed states in response to a drive signal supplied from an electronic control unit (not shown), and normally maintain the open state.

The holding solenoids 68RL and 68FR include
Check valves 70RL and 70FR, which allow only the flow of the working fluid from the downstream side toward the master cylinder 64 side, are arranged in parallel. Therefore, when the pressure on the master cylinder 64 side becomes lower than the pressure on the downstream side of the holding solenoids 68RL, 68FR, the holding solenoids 68RL, 68
Regardless of the open / closed state of FR, the holding solenoid 68RL,
The working fluid flows backward from the downstream side of 68FR to the master cylinder 64 side.

Downstream of the holding solenoid 68RL, a pressure reducing solenoid 72RL and a left rear wheel wheel cylinder 74 are provided.
Proportioning valve (PV) 76 communicating with RL
L is in communication. Further, a pressure reducing solenoid 72FR and a wheel cylinder 74FR for the right front wheel communicate with the downstream of the holding solenoid 68FR. Pressure reducing solenoid 72
RL and 72FR are two-position solenoid valves that switch between open and closed states in response to a drive signal supplied from an electronic control unit (not shown), and normally maintain the closed state.

A reservoir tank 78a communicates with the downstream side of the pressure reducing solenoids 72RL and 72FR. Also,
The suction hole of the ABS pump 80a communicates with the reservoir tank 78a. The ABS pump 80a has a motor 82
Is a pump for pumping the oil liquid as a drive source, and its discharge hole has a fixed damper 8 for the purpose of reducing pulsation of discharge hydraulic pressure.
It communicates with the upstream side of the holding solenoids 68RL and 68FR via 4a. Therefore, the pressure reducing solenoid 72R
When the brake fluid flows out to the downstream side of the L, 72FR, the brake fluid is temporarily stored in the reservoir tank 78a, and then returned to the upstream side of the holding solenoids 68RL, 68FR by the operation of the ABS pump 80a.

According to this structure, the holding solenoid 68
RL and 68FR open, and pressure reducing solenoid 72R
When L and 72FR are closed, the brake hydraulic pressure generated in the master cylinder 64 is applied to the wheel cylinders 74RL and 74RL.
The state guided to 74FR, that is, the pressure increasing mode is realized. When the holding solenoids 68RL and 68FR are closed and the pressure reducing solenoids 72RL and 72FR are closed, a state in which the brake hydraulic pressure in the wheel cylinders 74RL and 74FR is held, that is, a holding mode is realized. . Furthermore, holding solenoids 68RL, 68F
When R is closed and the pressure reducing solenoids 72RL, 72FR are open, the wheel cylinders 64RL, 64
A state in which the brake hydraulic pressure in FR can be discharged to the reservoir tank 78a, that is, a pressure reduction mode is realized.

The above-mentioned electronic control unit is provided with the wheels FL, during the braking operation in which the brake pedal 60 is depressed.
If the rotation states of FR, RL, RR are estimated and it can be determined that there is no possibility of shifting to the locked state for all wheels, the wheel cylinders 74RL, 74FR, 74R
The hydraulic path leading to the R and 74FL is set to the pressure increasing mode. Further, when it is detected that any of the wheels may shift to the locked state, the hydraulic pressure path corresponding to the wheel is appropriately set to the holding mode or the pressure reducing mode to reduce the excessive brake hydraulic pressure. As a result, each wheel is prevented from being locked during braking, and the ABS function is realized.

It should be noted that while the ABS is operating, the master cylinder 64
When the oil pressure in the cylinder is reduced, the brake fluid passes through the check valves 70RL and 70FR and the brake fluid flows to the wheel cylinders 74RL and 7RL.
Backflow from 4FR to the master cylinder 64 side. Therefore, regardless of the states of the holding solenoids 68RL and 68FR and the pressure reducing solenoids 72RL and 72FR, when the braking operation by the driver is stopped, the braking force disappears promptly thereafter.

In addition, during operation of the ABS, the reservoir tank 7
The brake fluid that has flowed out to the 8a side is appropriately pumped by the ABS pump 80a as described above. Therefore, even if the operation of the ABS continues for a long period of time, the master cylinder 64 will not be in the so-called bottomed state.

By attaching the cup seals 46 and 54 to the solenoid valves 10 and 50 described above, in the hydraulic circuit shown in FIG. 6, the holding solenoids 68RL, 60FR, 60FL,
Function of 60RR and check valve 60RL, 68FR, 68F
It can be used as a mechanism that also has the functions of L and 68RR (a mechanism that also has the function of the portion surrounded by the alternate long and short dash line in FIG. 6).

That is, the fluid passage 42 shown in FIG. 2 or 5 is communicated with the fluid passage 66a communicating with the master cylinder 64, and the fluid passage 44 shown in FIG. 2 or 5 is communicated with the pressure reducing solenoid 72RL and PV 76R. In this case, the solenoid valves 10 and 50 function as holding solenoids 68RL, and the cup seals 46 and 54 include check valves 70.
Functions as RL.

As described above, the cup seals 46, 54 incorporated in the ABS hydraulic circuit are operated when a braking operation is performed and a high fluid pressure is generated on the master cylinder 64 side as compared with the wheel cylinder 74RL side. Is an umbrella portion 46b, 54
b is opened to block the flow of the working fluid toward the wheel cylinder 74RL side. On the other hand, when the braking operation is completed and the fluid pressure on the wheel cylinder 74RL side is higher than the fluid pressure on the master cylinder 64 side, the umbrella portions 46b and 54b are quickly closed to close the master cylinder. 64
Allow the working fluid to flow to the side.

The check valve 70RL is an important component for realizing the ABS function in the hydraulic circuit shown in FIG. In this respect, according to the configuration of the present embodiment, the cup seals 46, 5
Therefore, the check valve 70RL can be provided with high reliability. Therefore, when the check valve of this embodiment is used in the hydraulic circuit of the ABS, the ABS as a whole can have high reliability.

[0060]

As described above, according to the first aspect of the present invention, even when the fluid pressure acts on the cup seal and the working fluid enters between the cup seal and the support member, The working fluid does not flow between the cup seal and the support member over the entire axial length of the cup seal.

When the flow of the working fluid over the entire axial length of the cup seal is blocked in this way, a sufficient frictional force always acts between the cup seal and the support member. Therefore,
According to the present invention, it is possible to realize a highly reliable check valve in which the cup seal does not drop off from the support member.

According to the second aspect of the present invention, the flow of the fluid infiltrating between the cup seal and the supporting member is surely prevented by guiding the fluid to the through hole opening in the supporting member. it can. Therefore, according to the present invention, a highly reliable check valve in which the cup seal does not drop off from the support member can be realized with a simple configuration.

According to the third aspect of the present invention, it is necessary for the cup seal fitted in the fitting groove of the support member to expand to a predetermined diameter or more, that is, to separate from the fitting groove. It is possible to prevent the diameter from expanding beyond the diameter. Therefore, according to the present invention, it is possible to realize a highly reliable check valve in which the cup seal does not drop off from the support member even when any force acts on the cup seal.

[Brief description of drawings]

FIG. 1 is a front sectional view of a solenoid valve incorporating a check valve according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a solenoid valve including a check valve according to the present embodiment in the vicinity of the check valve in an enlarged manner.

FIG. 3 is a diagram illustrating a flow path of a working fluid when a high-pressure fluid pressure in a forward direction acts on a conventional check valve.

FIG. 4 is a diagram showing a flow path of a working fluid when a high-pressure fluid pressure in a forward direction acts on a check valve of the present embodiment.

FIG. 5 is an enlarged cross-sectional view showing a solenoid valve including a check valve according to a second embodiment of the present invention in the vicinity of the check valve in an enlarged manner.

FIG. 6 shows a hydraulic circuit diagram of an antilock brake system in which a check valve according to the present invention is used.

[Explanation of symbols]

 10, 50 Electromagnetic valve 14 Electromagnetic coil 22 Plunger 24 Core 26 Valve seat 26d Fitting groove 26e Through hole 32 Housing 34, 36, 42, 44 Fluid passage 46, 54 Cup seal 46a, 54a Cylindrical part 46b, 54b Umbrella part 54c Cylindrical part Element

Claims (3)

[Claims] 1. A check valve formed by inserting a cup seal into a support member, comprising a blocking means for blocking a working fluid from flowing between the cup seal and the support member. Check valve to do. 2. The check valve according to claim 1, wherein the blocking unit includes a through hole that opens in a surface of the support member facing the cup seal. 3. A check valve formed by fitting a cup seal into a fitting groove of a support member, characterized by comprising deformation suppressing means for preventing the cup seal from expanding beyond a predetermined diameter. Check valve.