JPH06137445A - Check valve - Google Patents

Abstract

PURPOSE:To provide a check valve for closing or opening a fluid path provided in the outer periphery of a bevel part by means of the elastic deformation of the bevel part while holding proper valve opening pressure so as to prevent the bevel part from hardly sticking. CONSTITUTION:A bevel part 13 continuous with a tubular part 12 to be incorporated on a center shaft provided in a liquid path and folded back to the outside of the tubular part 12 is provided. The maximum diameter of the bevel part 13 is set slightly larger than the diameter of the fluid path. A plurality of lugs 14 are formed on predetermined positions on the outer periphery of the tubular part 12 and opposed to the bevel part 13. When fluid is going to flow backward in the fluid path, the bevel part 13 is expanded to prevent the counter flow. When the fluid flows forward, the bevel part 13 is closed to open the fluid path. Then, the lugs 14 prevent the tubular part 12 from hardly sticking to the bevel part 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check valve, and more particularly to a check valve which closes or conducts a fluid passage provided on the outer periphery of an umbrella-shaped portion by elastic deformation of the umbrella-shaped portion.

[0002]

2. Description of the Related Art Conventionally, as a check valve arranged in a fluid passageway, an umbrella-shaped portion is provided continuously from one end of a tubular portion to the outside, and the fluid passageway is closed or conducted by elastic deformation of the umbrella-shaped portion. There is known a reciprocating valve (Japanese Utility Model Laid-Open No. 4-25076).

FIG. 8 shows the structure of the check valve 1 described in the above publication, in which the cylindrical portion 2, the umbrella-shaped portion 3 and the rib 4 are integrally formed by a rubber elastic body. The check valve 1 is arranged in the fluid passage 6 with the central shaft 5 inserted in the tubular portion 2.

According to this check valve 1, in the fluid passage 6,
When a flow from the direction in which the cylindrical portion 2 and the umbrella upper portion 3 are continuous (a positive flow A in FIG. 8) occurs, the umbrella of the umbrella-shaped portion 3 is elastically deformed in the direction in which the fluid passage 6 is formed. It is conducted. Also,
When a reverse flow (backflow B in FIG. 8) occurs in the fluid passage 6, the umbrella of the umbrella-shaped portion 3 is elastically deformed in the opening direction to close the fluid passage 6.

The ribs 4 are radially provided between the cylindrical portion 2 and the umbrella-shaped portion 3. The rib 4 has a function of preventing the umbrella of the umbrella-shaped portion 3 from being inverted when a strong flow occurs in the backward flow B direction. Therefore, according to the check valve 1 described in the above publication, it is possible to secure a high pressure resistance against the backflow B and reliably prevent the backflow of the fluid in the fluid passage 6.

[0006]

However, in the structure of the above-mentioned conventional check valve, the ribs provided between the tubular portion and the umbrella-shaped portion reinforce the rigidity of the umbrella-shaped portion against the reverse flow of the fluid. As a result, the pressure resistance for backflow prevention is improved and the rigidity of the umbrella-shaped portion in the forward flow direction is also improved. Therefore, the valve opening pressure of the check valve increases as compared with the case where the rib is not provided, and the piping resistance in the forward flow direction increases.

In particular, when the diameter of the fluid passage is set to be small due to the demand for downsizing, the space between the tubular portion and the umbrella portion, that is, the space of the rib becomes narrow, so that the effect of improving the rigidity by the rib becomes remarkable. , The valve opening pressure rises significantly.

On the other hand, when the diameter of the fluid passage is sufficiently small, the operable area of the umbrella-shaped portion is narrowed, and the umbrella-shaped portion can be prevented from being inverted even if it is not reinforced by ribs. However,
In such a situation, when a check valve having no rib is used, the tubular portion and the umbrella portion may stick to each other and the function as the check valve may not be maintained.

That is, in the check valve having the conventional structure, particularly when the diameter of the fluid passage is set small, the tubular portion and the umbrella portion are fixed to each other while maintaining the valve opening pressure at an appropriate value. It had a problem that it could not be prevented.

The present invention has been made in view of the above-mentioned points, and is suitable by providing a convex portion on the outer periphery of the cylindrical portion constituting the check valve so as to prevent fixation with the umbrella-shaped portion. An object of the present invention is to provide a check valve capable of achieving both a valve opening pressure and a stable function.

[0011]

Means for Solving the Problems The above-mentioned problems include a tubular portion formed of an elastic body, and an umbrella-shaped portion which is continuous from one end of the tubular portion to the outside and has an umbrella shape. A check valve that is attached to a central shaft disposed inside and controls conduction of the fluid passage by elastic deformation of the umbrella-shaped portion, and a plurality of check valves are provided on a portion of the outer periphery of the tubular portion facing the umbrella-shaped portion. It is solved by the check valve provided with the convex part of.

[0012]

In the check valve having the above structure, the convex portion makes contact with the umbrella-shaped portion and the tubular portion over a wide area when the umbrella-shaped portion elastically deforms in the direction of the tubular portion. Prevent.
Therefore, sticking between the umbrella-shaped portion and the tubular portion is prevented,
The function as a check valve is maintained under high stability.

No member for improving the rigidity is attached to the umbrella-shaped portion. Therefore, the rigidity of the umbrella-shaped portion with respect to the flow in the forward flow direction can be independently set, and an appropriate valve opening pressure as a check valve can be secured.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of an embodiment of a check valve according to the present invention. FIG. 1A is a perspective view of FIG.
Shows a side sectional view.

As shown in FIG. 1, the check valve 11 of the present embodiment.
Is composed of a tubular portion 12, an umbrella-shaped portion 13, and a convex portion 14. The umbrella-shaped portion 13 is an umbrella-shaped member that is folded back from one end of the tubular portion 12. Further, the plurality of convex portions 14 are provided on the outer periphery of the tubular portion 12 at a predetermined portion facing the inside of the umbrella-shaped portion 13. Incidentally, these tubular parts 1
2, the umbrella-shaped portion 13 and the convex portion 14 are integrally formed by an elastic body.

Prior to the description of the effect of the check valve 11 of this embodiment, an example of a system to which the check valve 11 is applied will be described below.

FIG. 2 is a configuration diagram of a main part of an antilock brake system (ABS) which is an example of a system to which the check valve 11 of this embodiment is applied.

In FIG. 2, reference numeral 21 indicates a brake pedal. The brake pedal 21 is connected to a piston 22a of a master cylinder 22 filled with brake fluid, and when the driver steps on the brake pedal 21, the piston 22a is pressed according to the stepping force.

A hydraulic passage 26 is connected to the hydraulic chamber 22b of the master cylinder 22. The hydraulic passage 26 is connected to the reserve tank 25 via the solenoid valves 23 and 24.
And a branch between the solenoid valves 23 and 24, which leads to a wheel cylinder 27 that drives the brake mechanism of each wheel.

Further, the solenoid valve 23 is provided with a bypass passage 28 having the check valve 11 of this embodiment. The check valve 11 is arranged as a one-way valve that allows only the flow from the wheel cylinder 27 side to the master cylinder 22 side, and the bypass passage 28 bypasses only the flow in this direction.

When the ABS system shown in FIG. 2 is operating as a normal braking system, the solenoid valve 23 brings the hydraulic passage 26 into conduction. Further, in this case, the solenoid valve 24 closes the hydraulic passage 26. Each solenoid valve 23, 24 is electrically connected to an electronic control unit (ECU) 29, and EC
According to the control signal from U29, each hydraulic passage 26
It functions as an ABS by blocking or conducting.

That is, while the ABS is not functioning and the system of FIG. 2 is being used as the hydraulic system of the normal brake system, the brake fluid in the master cylinder 22 is changed to the hydraulic passage 26 by depressing the brake pedal 21.
And the wheel cylinder 2 via the solenoid valve 23.
7 is supplied. As a result, the brake mechanism provided on each wheel tries to stop the rotation of the wheel with a force corresponding to the pedaling force when the driver depresses the brake pedal 21.

As described above, the brake mounted on the vehicle is operated by supplying the brake fluid to the wheel cylinders 27. Therefore, when the pedaling force of the brake pedal 21 is released, it is necessary to immediately return the brake fluid from the wheel cylinder 27 to the master cylinder 22 in order to release the brake acting on each wheel.

The check valve 11 of this embodiment is provided in order to secure a route for the brake fluid to return to the master cylinder 22, and in order to obtain a good responsiveness when the brake is released, the check valve 11 is provided. It is necessary to set the valve opening pressure of as low as possible.

On the other hand, when the ECU 29 detects the lock of the wheel during braking based on signals from various sensors mounted on the vehicle, the ABS operates to unlock the wheel. . That is, the brake fluid is appropriately extracted from the wheel cylinder 27 corresponding to the locked wheel regardless of the driver's intention,
The brake is temporarily released. When the wheels are unlocked, the brake fluid is supplied to the wheel cylinder 27 again.

As the control performed by the ECU 29 in order to remove the brake fluid from the wheel cylinder 27 while the driver is stepping on the brake pedal 21, for example, the solenoid valve 23 is shut off and the solenoid valve 24 is switched on. Just do it. That is, in this case,
The flow from the master cylinder 22 to the wheel cylinder 27 is shut off by the solenoid valve 23 and the check valve 11, and the brake fluid flowing into the wheel cylinder 27 is passed through the solenoid valve 24 to the reserve tank 2
Outflow to 5.

At this time, if the check valve 11 is insufficiently prevented from backflowing, the brake fluid will still flow from the master cylinder 22 to the wheel cylinder 27 even if the solenoid valve 23 is closed.
Will continue to be supplied to. In this case, the brakes may not be released sufficiently, and the ABS function may not be fully exhibited.

As described above, the check valve 11 is an important component for ensuring the reliability of the ABS, and as described above, an appropriate valve opening pressure is required, and the check valve 11 has a high backflow prevention mechanism. Reliability is required.

FIG. 3 is a front sectional view showing the structure of a solenoid check valve in which the check valve 11 and the solenoid valve 23 shown in FIG. 2 are integrally provided. In the figure, the same components as those in FIG. 2 are designated by the same reference numerals.

The solenoid valve 23 has a housing 3
0, a coil 31 and a needle 32 housed in the housing 30. The needle 32 has a ball valve 32a at its tip and a permanent magnet 32b that produces a magnetic force in a predetermined direction at the other end. The permanent magnet 32b is arranged so as to be located at the axis of the coil 31.

Therefore, when a current flows through the coil 31,
An axial magnetic field corresponding to the direction of the current acts on the permanent magnet 32b, and the permanent magnet 32b receives an external force in the axial direction. The direction of the external force received by the permanent magnet 32b is the coil 3
The needle 32 can be reversed by changing the direction of the current flowing through the needle 1, and the needle 32 moves in the axial direction according to the reversal of the external force.

A fluid inflow passage 33 is provided on the extension line of the needle 32 of the housing 30. The inflow passage 33 has an opening at the tip of the housing 30 and is electrically connected to the vicinity of the tip of the needle 32 via an orifice 34. The orifice 34 is used for the ball valve 3
Since the needle 32 is disposed on the axial extension line of 2a, it is closed by the ball valve 32a when the needle 32 is located at the tip end side, and is opened when the needle 32 is located at the rear end side.

The housing 30 is further provided with a fluid outflow passage 35 extending from the vicinity of the tip of the needle 32 in the direction perpendicular to the axis and opening to the side surface of the housing 30. That is, when the orifice 34 is blocked by the needle 32, the inflow passage 33 and the outflow passage 35 are blocked,
Further, when the needle 32 opens the orifice 34, the inflow passage 33 and the outflow passage 35 are in a conductive state.

In FIG. 3, reference numeral 40 denotes a solenoid check valve which is a combination of the check valve 11 and the solenoid valve 23. The solenoid valve 23 corresponds to the central axis when the check valve 11 is attached. Reference numeral 41 denotes a housing block, which houses the check valve 11 and the solenoid valve 23, and is provided with fluid passages 42 and 43 which communicate with the master cylinder 22 and the wheel cylinder 27.

One of the fluid passages 42 has a hydraulic chamber 22b of the master cylinder 22 shown in FIG. 2 and a solenoid valve 23.
The fluid passage 43 communicates with the vicinity of the outflow passage 35 of the solenoid valve 23 and the wheel cylinder 27.

A predetermined gap is provided between the housing 30 of the solenoid valve 23 and the housing block 41 of the solenoid check valve 40.
When 1 does not exist, the two fluid passages 42 and 43 are brought into conduction through this gap. The housing 30
The space between the housing block 41 and the housing block 41 is sealed by an O-ring as shown in FIG. 3, so that the brake fluid supplied from the master cylinder 22 is released by the solenoid check valve 4.
It does not leak to the outside of 0.

The check valve 11 of the present embodiment is attached near the tip of the solenoid valve 23, and the umbrella-shaped portion 13 closes the gap provided between the housing 30 and the housing block 41 to prevent fluid flow. The conduction between the passages 42 and 43 is controlled. That is, when the master cylinder 22 side has a high pressure and the wheel cylinder 27 side has a low pressure, the umbrella-shaped portion 13
Opens to close the connection between the fluid passages 42 and 43, blocking the flow of brake fluid. In the opposite case, the umbrella-like portion 13 is closed, the fluid passages 42 and 43 are electrically connected, and the brake fluid flows from the wheel cylinder 27 side to the master cylinder 22 side.

Therefore, in the solenoid check valve 40 shown in FIG. 3, when the needle 32 does not close the orifice, the master cylinder 22 to the wheel cylinder 27 are used.
The flow of the brake fluid to the flow path is controlled only to the flow from the inflow passage 33 through the orifice 34 to the outflow passage 35.

In this state, when the internal pressure of the master cylinder 22 drops and the brake fluid returns from the wheel cylinder 27 to the master cylinder 22, the orifice 34 is used.
Because of the large resistance of most brake fluids,
A route in which the umbrella-shaped portion 13 of the check valve 11 is electrically connected by elastic deformation, that is, the housing 30 and the housing block 41.
It will flow through the gap between.

As described above, no reinforcing member is attached to the umbrella-shaped portion 13 of the check valve 11 of this embodiment. Therefore, the valve opening pressure of the check valve 11 is a value determined only by the elastic force of the umbrella-shaped portion 13. Further, the gap between the housing 30 and the housing block 41 is sufficiently smaller than the size of the umbrella-shaped portion 13, and the umbrella-shaped portion 13 is not inverted due to the high pressure on the master cylinder 22 side. Therefore, according to the check valve 11 of the present embodiment, the valve opening pressure can be easily set to an appropriate value while maintaining the function of the check valve 11 with high reliability. .

In the solenoid check valve 40, when the orifice 34 is closed by the needle 32, the route through which the brake fluid flows from the master cylinder 22 side to the wheel cylinder 27 side is cut off, and thereafter. The brake fluid is not supplied to the wheel cylinder 27 no matter how hard the driver depresses the brake pedal 21.

Next, the effect of providing the convex portion on the tubular portion 12 in the check valve of this embodiment will be described.

4 to 6 are views showing a case where a check valve having a conventional structure is used as the solenoid check valve 40.
Hereinafter, the difference between the check valve of the conventional configuration and the check valve 11 of the present embodiment will be described with reference to the drawings. In each figure, the same components as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 4 is a diagram showing a case where a check valve having the most commonly used structure is applied. The check valve 51 shown in FIG. 4 includes a tubular portion 52 and an umbrella-shaped portion 53 continuously provided at one end of the tubular portion 52.

As shown in FIG. 4 (A), when the pressure in either direction is not generated in the brake fluid, the check valve 5
1 closes the gap between the housing 30 and the housing block 41 as in the check valve 11 of this embodiment.

Then, as shown in FIG. 4B, when a flow from the fluid passage 43 on the wheel cylinder side to the fluid passage 42 on the master cylinder side is generated, the umbrella portion 53 is elastically deformed toward the tubular portion 52 side. Then, a route through which the brake fluid can flow is created. At this time, the check valve 51 does not have a convex portion unlike the check valve 11 of the present embodiment. Therefore, when the pressure that presses the umbrella-shaped portion 53 is high, the umbrella-shaped portion 53 may come into close contact with the tubular portion 52 as shown in FIG. 4B.

FIG. 5 shows a diagram when the check valve 51 is elastically deformed by the finite element method (FEM).
In addition, the result shown in FIG. 5 is 27.5 × 10 ⁴ Pa (2.8 kg / c) between the wheel cylinder 27 and the master cylinder 22.
It shows the case where a pressure difference of m ² ) occurs.

From the state where no external force is applied to the check valve 51 (FIG. 5 (A)), an external force for elastically deforming the umbrella portion 53 to the tubular portion 52 side is applied, and the check valve 51 shown in FIG. When the tip of the umbrella-shaped portion 53 is deformed until it comes into contact with the housing 30 as shown in (4), a space is isolated from the outside between the umbrella-shaped portion 53 and the tubular portion 52. And the umbrella-shaped portion 5
When 3 is pressed in the direction of the tubular portion 52, the umbrella-shaped portion 53 deforms so as to reduce this space.

After that, when the force for elastically deforming the umbrella-shaped portion 53 disappears, the check valve 51 tries to restore its original shape due to its elasticity. Therefore, the umbrella-shaped portion 53 tends to be displaced in the direction away from the tubular portion 52. However, the tubular portion 5
Between the 2 and the umbrella-shaped portion 53, there is a space shielded from the outside as described above. Then, the force that presses the umbrella-shaped portion 53 toward the tubular portion 52 disappears, and at the same time, the umbrella-shaped portion 53
A negative pressure is generated in this space due to the restoring force of.

Therefore, the check valve 51 can no longer return to its original shape, and the umbrella-shaped portion 53 remains deformed to the tubular portion 41 side as shown in FIG. 5 (C). Becomes FIG. 4B shows the case where the tubular portion 51 and the umbrella-shaped portion 53 are fixed to each other by the same principle as that shown in FIG.

Further, FIG. 4C shows a case where the cylindrical portion 52 and the umbrella-shaped portion 53 are fixed to each other by a principle different from that of FIG. In this case, the fixation of the tubular portion 52 and the umbrella-shaped portion 53 is caused by the thermal expansion of the check valve 51. That is, when the solenoid check valve 40 is left in a high temperature atmosphere, the check valve 51 expands, and the tubular portion 52 and the umbrella portion 53.
And are in close contact. Also in this case, a space that is shielded from the outside is generated between the cylindrical portion 52 and the umbrella-shaped portion 53.
Therefore, when the atmospheric temperature is lowered thereafter, as in the case of FIG. 5, the space becomes negative pressure, and the cylindrical portion 52 and the umbrella-shaped portion 5 are
3 is in a fixed state.

As described above, in the conventional check valve 51 described above, when the umbrella-shaped portion 53 is deformed, the umbrella-shaped portion 53 and the tubular portion 51 are formed.
A negative pressure space may be generated between and, and when a negative pressure is generated in this space, the check valve 51 cannot thereafter function as a check valve.

On the other hand, the check valve 11 of this embodiment is
Since the plurality of convex portions 14 are provided at the predetermined positions where the tubular portion 12 and the umbrella-shaped portion 13 face each other as described above, even if the umbrella-shaped portion 13 is pressed toward the tubular portion 12 side, In the meantime, no space is cut off from the outside. Therefore, according to the check valve 11 of the present embodiment, the tubular portion 12 and the umbrella portion 13 are provided.
The function of the check valve can be stably maintained without sticking to each other.

FIG. 6 is a block diagram showing a case where the check valve 1 shown in FIG. 8 is used as a check valve having a conventional structure. still,
6, the same components as those in FIGS. 3 and 8 are designated by the same reference numerals and the description thereof will be omitted.

The check valve 1 is provided with the ribs 4 radially between the cylindrical portion 2 and the umbrella-shaped portion 3 as described above. Therefore, unlike the above-described conventional check valve 51, the tubular portion 2 and the umbrella-shaped portion 3 do not stick to each other under various conditions.

However, the ribs 4 of the check valve 1 act to improve the rigidity of the umbrella-shaped portion 3. Therefore, a large force is required to elastically deform the umbrella-shaped portion 3 toward the tubular portion 2, and when applied to the solenoid check valve 40 described above, the brake fluid returns from the wheel cylinder 27 side to the master cylinder 22 side. Will be delayed, and the release characteristics of the brake will be deteriorated.

Further, in the umbrella-shaped portion 3, the rib 4
The rigidity of the portion where the ribs 4 exist is significantly different from the rigidity of the portion where the ribs 4 do not exist. Therefore, as shown in FIG. 6 (A), when the umbrella-shaped portion 3 is deformed so as to prevent the flow of the brake fluid, the umbrella-shaped portion 3 shows different deformations between a non-rigid portion and a certain portion. That is, a large amount of deformation occurs in the non-rigid portion as compared with the rigid portion, and stress concentrates on that portion.

Therefore, as shown in FIG. 6B, the surface of the check valve 1 that is pressed against the housing 30 when the flow of the brake fluid is blocked is caused by the variation in the rigidity of the umbrella-shaped portion 3. Variation occurs. As described above, the above-described conventional check valve 1 has problems that it is difficult to set the valve opening pressure low and that the durability of the non-rigid portion is difficult.

On the other hand, the check valve 11 of this embodiment is
As described above, since no reinforcing member is attached to the umbrella-shaped portion 13, its rigidity is uniform. Therefore, the stress when shutting off the fluid is dispersed, and high durability can be secured.

The shape of the convex portion attached to the cylindrical portion 12 is
The shape is not limited to the shape attached to the check valve 11 of the above embodiment, but may be a spline shape having the longitudinal direction in the axial direction as shown in FIG. 7, for example.

According to the structure of the check valve 61 shown in FIG. 7, the axial rigidity of the tubular portion 12 can be ensured by the spline 62 corresponding to the convex portion of the check valve according to the present invention. 12 can be thinned. Therefore, the space required for the tubular portion 12 can be reduced as compared with the conventional check valve. Further, the flexibility of the cylindrical portion 12 in the circumferential direction is improved, and the assembling property when the check valve 61 is attached to the housing 30 of the solenoid valve 23 corresponding to the central axis is remarkably improved.

[0062]

As described above, according to the present invention, the convex portion provided on the cylindrical portion prevents the formation of a space that is shielded from the outside between the upper portion of the cylinder and the umbrella-shaped portion. Therefore, it is possible to prevent the umbrella-shaped portion and the upper part of the cylinder from being fixed to each other while maintaining the rigidity of the umbrella-shaped portion uniformly over the entire circumference. That is, the check valve according to the present invention has a feature that it has an appropriate opening pressure and significantly higher reliability than the conventional check valves.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a check valve according to the present invention.

FIG. 2 is a configuration diagram of an example of a system using the check valve of the present embodiment.

FIG. 3 is a front cross-sectional view showing the configuration of a solenoid check valve including the check valve of the present embodiment as a component.

FIG. 4 is a diagram for explaining the effect of the check valve of the present embodiment.

FIG. 5 is a diagram for explaining the principle of fixing the tubular portion and the umbrella portion in the conventional check valve.

FIG. 6 is a diagram for explaining another problem in the conventional counter valance valve.

FIG. 7 is a configuration diagram of another embodiment of the check valve according to the present invention.

FIG. 8 is a configuration diagram of a conventional check valve.

[Explanation of symbols]

 11,61 Check valve 12 Cylindrical part 13 Umbrella part 14 Convex part 22 Master cylinder 23,24 Solenoid valve 27 Wheel cylinder 30 Housing 40 Solenoid check valve 41 Housing block 62 Spline

Claims (1)

[Claims] 1. A central axis disposed in a fluid passage, comprising a tubular portion formed of an elastic body, and an umbrella-shaped portion which continuously extends outward from one end of the tubular portion and has an umbrella shape. A check valve attached to control the conduction of the fluid passage by elastic deformation of the umbrella-shaped portion, wherein a plurality of convex portions are provided on a portion of the outer periphery of the tubular portion facing the umbrella-shaped portion. And a check valve.