JP3502820B2 - Relief valve - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a relief valve.

[0002]

2. Description of the Related Art As a relief valve incorporated in a flow control valve of a power steering apparatus, for example, Japanese Patent Laid-Open No. 8-
No. 42513 has been proposed.

FIG. 10 shows the flow control valve 200. As shown, the relief valve 250 is incorporated in the spool 201 of the flow control valve 200.

In the flow control valve 200, the hydraulic oil supplied from the pump port P to the supply chamber 202 on the tip end side of the spool 201 is supplied from the orifice 203 to the hydraulic oil supply port 204.
And is supplied to the power steering device. The hydraulic pressure on the hydraulic oil supply port 204 side (the hydraulic pressure on the downstream side of the orifice 203) is the flow control spring chamber 20 on the proximal end side of the spool 201.
Introduced in 5. The spool 201 is balanced by the thrust of the hydraulic pressure of the supply chamber 202 (the hydraulic pressure of the orifice 203 upstream) and the balance of the spring force of the spring 206 provided in the flow control spring chamber 205 and the reaction force of the hydraulic pressure of the flow control spring chamber 205. Move. When the differential pressure between the upstream and downstream of the orifice 203 increases as the pump speed increases, the supply chamber 20
The thrust due to the hydraulic pressure of 2 exceeds the reaction force, the spool 201 moves in the proximal direction (leftward in FIG. 10), and the supply chamber 202 communicates with the tank port T. As a result, a part of the flow rate from the pump port P is returned to the tank, and the flow rate is controlled.

Further, when the load on the power steering device side increases and the hydraulic pressure at the hydraulic oil supply port 204 suddenly increases, if the hydraulic pressure in the pressure control spring chamber 205 exceeds the set pressure of the relief valve 250, the relief valve 250 will be activated. It is pushed open and the hydraulic pressure in the pressure control spring chamber 205 is released to the tank port T. As a result, the spool 201 moves in the proximal direction,
As a result of the hydraulic pressure in the supply chamber 202 being released to the tank port T, the supply pressure is prevented from increasing beyond the allowable pressure.

[0006]

However, in such a relief valve 250, the ball support member 252 for supporting the ball 251 as the valve body and the valve hole 2 are provided.
Since there is a large gap with the inner circumference of 53, when the relief valve 250 is opened, the movable member (the ball 251 and the ball support member 252) is moved by the influence of the inclination of the return spring 254 and the lateral force of the flow. There was a problem that it was easy to shake laterally.

Further, in such a relief valve 250,
In a transitional state in which the movable member is pushed open, there is a problem that abnormal noise occurs due to a chattering phenomenon in which the operation of the movable member becomes unstable. In order to suppress this chattering phenomenon, it is conceivable to reduce the diameter of the seat orifice 255, but this causes deterioration of the override characteristic (the characteristic of the difference between the set pressure and the cracking pressure) of the relief valve 250 due to the increase in pressure loss. I will end up.

The present invention has been made in view of such a problem, and provides a relief valve which can stabilize the operation of the movable member and can prevent the chattering phenomenon and improve the override characteristic. The purpose is to do.

[0009]

According to the first invention, a valve is provided.
Ball 5 for opening and closing seat hole 6B opened in seat 6
And support the ball 5 from the opposite side of the valve seat 6.
For a relief valve equipped with a ball support member 4 to hold
At the end of the ball support member 4 on the ball side.
A flange portion 4A having a substantially circular cross section and the ball support
It is formed in a part of the accommodating portion 62 that accommodates the member 4,
A guide recess 62A having a diameter larger than the above, the collar 4A and the guide
Orifice 6 formed in the gap between the recess 62A
3 and 3. In the second invention, the valve seat 6
The ball 5 for opening and closing the opened seat hole 6B and the bow
For supporting the ball 5 from the opposite side of the valve seat 6
A relief valve including a support member 72, wherein
The ball support member 72 is replaced with the ball support member 7
The ball support is slidably contacted with the inner peripheral surface 7A of the second accommodating portion.
On the outer peripheral surface of the member 72, the axial direction of the ball support member 72
Forming a plurality of grooves 73 extending to the. In the third invention
Opens and closes the seat hole 6B opened in the valve seat 6.
Ball 5 and the ball 5 opposite the valve seat 6
The ball support member 82 supported from the side, and the ball
Installed on the outer periphery of the support member 82, the ball support section
Return spring that urges the material toward the valve seat 6 side
In the relief valve including the
The inner circumference of the accommodating portion of the ball support member 82.
The surface of the ball support member 82 is slidably contacted with
It is the circumference and has an opening on the installation side of the return spring 3.
Is provided with a plurality of recesses 83, and the recesses 83 are
Through hole 8 penetrating the ball support member 82 in the axial direction
4 is forming. However, the reference numerals are used in the embodiment for reference.
Correspondingly attached.

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

In the first aspect of the invention, the gap between the flange 4A and the guide recess 62A is located downstream of the seat hole.
Since the orifice 63 is provided in the above, the presence of this orifice stabilizes the operation of the movable member (for example, the ball 5 and the ball support member 4) and suppresses the generation of abnormal noise due to the chattering phenomenon. In addition, since pressure builds up in the seat hole downstream portion upstream of the orifice, the override characteristic of the relief valve is also improved.

Further, since the gap portion between the flange portion 4A and the draft in the recess 62A is an orifice directly attenuation is given to the operation of the movable member, the operation of the movable member is stabilized, the chattering The prevention and the improvement of the override characteristic can be achieved extremely effectively.

In the second and third aspects of the invention, the ball support member 72 or 82 is in sliding contact with the inner peripheral surface 7A of the accommodating portion, so that lateral runout is completely prevented. Also, the second departure
Clear grooves formed on the outer peripheral surface of the ball support member 72
73 is easy to machine and can be machined with high precision.
It is also possible to set the damping force by the orifice appropriately.
Wear. Further, the groove 73 is formed on the outer periphery of the ball support member 72.
Since it is formed , the return spring 3 does not close the orifice even when the return spring is installed.

In the third invention, a bow that is an orifice is used.
Since the through hole 84 of the support member 82 can be easily processed and can be processed with high accuracy, the damping force by the orifice can be appropriately set.

Further, in the third invention, since the through hole 84 , which is an orifice, is formed so as to open in the recess 83 , the return spring 3 does not close the orifice.

[0024]

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

In each of the following embodiments, the relief valve of the present invention is incorporated in a flow control valve for controlling a hydraulic oil supply amount from a vane pump to a power steering device in a power steering device of an automobile.

1 and 2 show the structure of a vane pump 20 common to the respective embodiments.

As shown, the vane pump 20 is
Body 21, cover 22, shaft 23, rotor 24,
It is composed of a cam ring 25, a side plate 26 and the like.

The shaft 23 is a drive shaft of a rotor 24 provided in the body 21, and is rotatably supported by the body 21. The shaft 23 is connected to an engine of an automobile (not shown) and rotates with the rotation of the engine.

The rotor 24 is arranged inside a cam ring 25 having an elliptical inner wall. Further, the rotor 24 is
It is sandwiched between the cover 22 and the side plate 26, and the front and rear sides are closed.

A plurality of vanes 27 are provided on the outer periphery of the rotor 24.
Are radially incorporated. These vanes 27
The rotor 24 can freely appear and appear. Then, as the rotor 24 rotates, the vanes 27 are
The tip portion extends until it comes into contact with the inner peripheral surface of the cam ring 25. As a result, a pump chamber is formed between the vanes 27 and expands and contracts as the rotor 24 rotates.

In the expansion stroke of these pump chambers, the working oil is sucked from the low pressure passage 28 communicating with the tank (not shown). On the other hand, in the contraction stroke, the hydraulic oil is discharged to the high pressure passage 29. The high-pressure passage 29 communicates with a power steering device (not shown) via a flow control valve 30 described later.

FIG. 3 shows the structure of the flow control valve 30 and the relief valve 1 incorporated in the flow control valve 30 according to the first embodiment of the present invention.

In the power steering system, when the engine rotates at a low speed, the amount of hydraulic oil supplied to the power steering system needs to increase as the engine speed increases. On the other hand, when the engine rotates at high speed, the amount of hydraulic oil supplied to the power steering device needs to be limited so that it does not increase even if the engine speed increases. The flow rate control valve 30 is provided for such a flow rate control, and when the engine speed (the speed of the vane pump 20) increases, the flow rate control valve 30 drains hydraulic oil that exceeds the required hydraulic oil supply amount. Act on.

The flow control valve 30 is constructed by slidably accommodating the spool 40 in a sliding hole 31 formed in the body 21 of the vane pump 20. A connector 32 is screwed on the opening end side of the sliding hole 31. The hollow portion of the connector 32 serves as a hydraulic oil supply port 32A to a power steering device (not shown).

A plug 33 is attached to the bottom of the connector 32. An opening is formed in the plug 33. A tip portion 41 of the spool 40 penetrates through this opening, and a portion between the outer circumference of the tip portion 41 and the inner circumference of the opening serves as an orifice 33A.

The tip portion 41 of the spool 40 has a large diameter portion 41A on the tip side and a small diameter portion 41B inside the large diameter portion 41A.
Consists of. As a result, the opening area of the orifice 33A changes depending on whether there is the large diameter portion 41A or the small diameter portion 41B inside the opening.

In the present embodiment, the opening area of the orifice 33A is made variable by the tip portion 41 of the spool 40 as described above. However, as will be described later (see the embodiment of FIG. 9), the orifice 33A is changed. A member for changing the opening area of the orifice 33 is separated from the flow control valve 30, and the orifice 33
The member for changing the opening area of A may be driven by a solenoid. As a result, the opening area of the orifice 33A can be controlled more accurately.

The hydraulic oil supply port 32A (downstream of the orifice 33A) has a flow rate control spring chamber 35, which will be described later, and a communication passage 37.
Through the. An orifice 38 is provided between the communication passage 37 and the hydraulic oil supply port 32A, and an orifice 39 is provided between the communication passage 37 and the flow rate control spring chamber 35.

The tip portion 41 of the spool 40 (small diameter portion 41
A contact step portion 42 is formed on the base end side of B). The contact step portion 42 has a larger diameter than the opening of the plug 33. As a result, when the spool 40 moves to the tip end side (left side in the drawing) and the tip end surface 42A of the contact step portion 42 is in contact with the plug 33, the orifice 33A is in contact with the contact step portion 4.
It is designed to be closed by 2.

A sliding portion (land portion) 43 is formed on the base end side of the contact step portion 42 of the spool 40. The sliding portion 43 slides along the inner peripheral surface of the sliding hole 31. Sliding hole 3
Due to the sliding portion 43, the inside of the inside 1 of the supply chamber 34 (upstream of the orifice 33A) on the tip side of the spool 40 (left side in the drawing).
And a flow control spring chamber 35 on the proximal end side (right side in the drawing) of the spool 40.

The base end side of the sliding portion 43 of the spool 40 is a base end portion 44 having a smaller diameter than the sliding portion 43.
A flow rate control spring 36 is arranged on the outer circumference of the base end portion 44. The flow control spring 36 has its base end in contact with the bottom portion of the sliding hole 31, and always biases the spool 40 in the front end direction (leftward in FIG. 3).

The vane pump 20 is provided on the side surface of the sliding hole 31.
A pump port P communicating with the high pressure passage 29 and a tank port T communicating with the tank are open. The pump port P is located near the open end of the sliding hole 31 and is in constant communication with the supply chamber 34. The tank port T is located on the inner side (right side in the drawing) of the sliding port 31 than the pump port P, and the movement of the spool 40 allows communication with the supply chamber 34.
The communication area can be switched between non-communication and communication.

The relief valve 1 is incorporated in the spool 40.

The relief valve 1 acts as a pilot valve when pressure control is performed in the flow control valve 30. That is, when a large load is applied to the power steering device and the pressure of the hydraulic oil supply port 33A rapidly increases, the flow rate control valve 30 also functions as a pressure control valve that lowers the supply pressure from the vane pump 20. In such pressure control, the relief valve 1 has a hydraulic oil supply port 33.
It is incorporated in the spool 40 of the flow path switching valve 30 as a valve for switching the flow rate control valve 30 when the pressure of A rises.

The relief valve 1 is constructed by assembling a return spring 3, a ball support member 4, a ball 5, a valve seat 6, a sleeve member 7 and the like into a valve hole 2 which is opened at the base end side of the spool 40.

The sleeve member 7 is fixed to the inner peripheral surface of the valve hole 2 on the opening end side. The valve seat 6 is fixed to the inner peripheral surface 7A of the sleeve member 7. A seat orifice 6A is provided coaxially with the valve seat 6, and a downstream end of the seat orifice 6A serves as a seat hole 6B. The opening end of the valve hole 2 (seat orifice 6
The filter 8 is attached to the upstream side of A).

The ball 5 and the ball support member 4 are arranged on the downstream side (left side in FIG. 3) of the valve seat 6. A return spring 3 is provided on the outer circumference of the ball support member 4. The return spring 3 is bridged between the collar portion 4A of the ball support member 4 and the bottom surface of the valve hole 2 to constantly urge the ball support member 4 toward the valve seat 6 side.

The ball 5 is supported by the ball support member 4 from the side opposite to the valve seat 6, and the spring force of the return spring 3 allows the seat hole 6B of the valve seat 6 to be supported.
Is pressed against the sheet hole 6B to close the seat hole 6B. And
When the force due to the fluid pressure in the flow rate control spring chamber 35 of the flow rate control valve 30 exceeds the spring force of the return spring 3, the ball 5 is pushed down, and the valve hole 2 from the seat orifice 6A and the seat hole 6B. Hydraulic fluid is introduced inside.

A flange portion 4A is formed at the end of the ball support member 4 on the ball 5 side. The collar portion 4A includes a chamber 9 on the valve seat 6 side inside the valve hole 2 and
It is defined in the pressure control spring chamber 10 on the return spring 3 side.

An orifice 11 is formed between the collar portion 4A and the inner peripheral surface 7A of the sleeve member 7 extending to the side of the collar portion 4A. As will be described later, the presence of the orifice 11 makes it possible to stabilize the operations of the ball support member 4 and the ball 5 in the relief valve 1 without deteriorating the override characteristic, and suppress the noise generation due to the chattering phenomenon. . In this case, the width (diameter) of the orifice 11 is set to the collar portion 4
By setting the outer diameter of A to 1/20 or less, a sufficient damping effect can be given to the operation of the ball support member 3. In addition, the width of the orifice 11 is 1 / the outer diameter of the collar portion 4A.
It has been confirmed by experiments and analysis that a sufficient damping effect can be obtained when the ratio is 20 or less.

The pressure control spring chamber 10 includes a plurality of oil passages 12
And the tank port T via the outer peripheral groove 13. The outer peripheral groove 13 is an annular groove formed on the outer periphery of the sliding portion 43 of the spool 40.

Next, the operation will be described.

When the engine of the automobile is started from the stopped state, the vane pump 20 rotates in synchronization with the engine rotation, and the pump port P is provided in the supply chamber 34 of the flow control valve 30.
Is supplied with hydraulic oil. This hydraulic oil is used in the orifice 3
It flows into the hydraulic oil supply port 32A via 3A and is supplied to the power steering device. In this way, when the pump rotational speed is low and the hydraulic oil supply amount to the power steering device is small, the hydraulic oil supply amount increases in proportion to the pump rotational speed.

In this case, the supply chamber 34 (orifice 33A
Upstream) and the hydraulic oil supply port 32A (downstream of the orifice 33A) is determined by the opening area of the orifice 33A and the flow rate passing through the orifice 33A, and the rotation speed of the vane pump 20 increases and passes through the orifice 33A. It increases as the flow rate increases.

The hydraulic pressure of the hydraulic oil supply port 32A is guided to the pressure control spring chamber 35 of the flow rate control valve 30 through the orifice 38, the oil passage 37, and the orifice 39. Therefore, when the rotation speed of the vane pump 30 increases and the differential pressure between the upstream and downstream of the orifice 33A increases, the spool 30 becomes
It moves in the proximal direction (rightward in the figure) against the flow control spring 36. That is, the flow rate through the orifice 33A increases, and the thrust force to move the spool 40 in the proximal direction (the product P1 × A1 of the pressure P1 of the supply chamber 34 and the pressure receiving area A1 of the spool 40 on the supply chamber 34 side). However, the reaction force (spring force F of the flow rate control spring 35, the pressure P2 of the flow rate control spring chamber 35, and the flow rate control spring chamber 35 side of the spool 40 side that pushes the spool 40 back in the tip direction (left direction in the drawing). Of the pressure receiving area A2, P2 × A2, and the sum F + (P2 × A2)), and the spool 40 retracts in the proximal direction.

By retreating the spool 40, the supply chamber 3
4 communicates with the tank port T. As a result, a part of the hydraulic oil supplied from the pump port P is released to the tank port T, so that the increase in the hydraulic oil supply amount to the power steering device is suppressed even if the pump rotation speed increases. become. Further, when the large diameter portion 41A of the spool 40 moves into the orifice 33A, the opening area of the orifice 33A is narrowed and the amount of hydraulic oil supplied to the power steering device is further suppressed. In this way, the amount of hydraulic oil supplied to the power steering device is controlled according to the pump rotation speed.

The pressure in the supply chamber 34 is controlled as follows. For example, when the pressure of the hydraulic oil supply port 32A is rapidly increased by kickback or the like from the power steering device side, this pressure is transmitted to the flow rate control spring chamber 35 via the orifice 38, the oil passage 37, and the orifice 39. To be done. As a result, when the pressure in the flow control spring chamber 35 increases and exceeds the set pressure of the relief valve 1, the relief valve 1
Is pushed open, and the flow rate control spring chamber 35 and the tank port T communicate with each other. That is, the ball 5 and the ball support member 4 are pushed open against the spring force of the return spring 3, whereby the hydraulic pressure of the flow rate control spring chamber 35 causes the filter 8, the seat orifice 6A, the seat hole 6B, the chamber 9, It escapes to the tank port T via the orifice 11, the pressure control spring chamber 10, the oil passage 12, and the outer peripheral groove 13. As a result, the pressure in the flow rate control spring chamber 35 decreases to the tank pressure, and the spool 40 retreats greatly to the right in the figure. As a result, the supply pressure of the supply chamber 34 is released to the tank port T and is controlled so as not to become excessive. Further, the opening area of the orifice 33A has a large diameter portion 41A.
The flow rate flowing into the power steering device side is limited to a small amount by being narrowed by.

The relief valve 1 functions in this way in pressure control, but in the present embodiment, the width of the collar portion 4A of the ball support member 4 is widened so that the collar portion 4A and the inner peripheral surface 7A of the sleeve member 7 are widened. The orifice 11 is formed between and. Therefore, due to the resistance (pressure loss) and damping force when the hydraulic oil passes through this orifice 11,
The override is improved, the operation of the ball support member 4 is stabilized, and the chattering phenomenon can be suppressed. That is, vibration of the ball support member 4 in the axial direction and the lateral direction can be suppressed, and the generation of abnormal noise due to this vibration can be prevented. Further, due to the presence of the orifice 11, the chamber 9
Pressure rises (downstream of the seat hole 6B of the relief valve 1),
Moreover, since this pressure increases as the flow rate increases,
The override characteristic of the relief valve 1 (the characteristic of the difference between the set pressure of the relief valve 1 and the cracking pressure) is improved.

FIG. 4 shows a flow control valve 30 according to the second embodiment of the present invention and a relief valve 61 incorporated in the flow control valve 30.

The present embodiment is different from the first embodiment except that the structure of the relief valve 61 is different from the structure of the relief valve 1 in the following points as compared with the first embodiment. Common.

Explaining the difference between the relief valve 61 and the relief valve 1, the sleeve member 67 of the relief valve 61 of the present embodiment is shorter than the sleeve member 7 of the relief valve 1 and has a collar portion 4A of the ball support member 4. Has not extended to the side. Instead, a guide recess 62A is formed in the valve hole 62 at the side of the flange 4A, and the gap between the flange 4A and the guide recess 62A serves as the orifice 63. In this case, the width (diameter) of the orifice 63 is set to 1/20 or less of the outer diameter of the collar portion 4A so that a sufficient damping effect can be given to the operation of the ball support member 3.

Therefore, the present embodiment has the same effects as those of the first embodiment described above, and the inner diameter of the sleeve member 61 and the outer diameter of the collar portion 4A are set to the orifice 63.
Since it is not necessary to adjust to a relationship that forms
The degree of freedom in design is increased.

The guide recess 62A is not necessarily provided in the valve hole 62, and the orifice 63 may be formed between the inner peripheral surface of the valve hole 62 and the flange 4A.

FIG. 5A shows a relief valve 71 according to the third embodiment of the present invention. Further, FIG. 5B shows a cross-sectional view taken along the line BB of FIG.

This relief valve 71 has a basic structure in common with the relief valve 1 of the first embodiment, and differs only in the points described below. Further, this relief valve 71 is incorporated in the spool 40 of the flow path switching valve 30 similarly to the relief valve 1 of the first embodiment.

Explaining the difference between the relief valve 71 and the relief valve 1, in the relief valve 71 of the present embodiment, the flange portion 72A of the ball support member 72 is made slightly wider in the axial direction and the outer peripheral surface thereof. Completely slidably contact the inner peripheral surface 7A of the sleeve member 7. And the collar 72
A plurality of grooves (in the present embodiment, four notches provided at intervals of 90 degrees) extending in the axial direction of the ball support member 72 are formed on the outer peripheral surface of A, and these grooves form the orifice 73. Has become.

Due to the orifice 73, the relief valve 71 of the present embodiment can provide the same operational effect as the relief valve 1 of the first embodiment. Further, in the present embodiment, since the collar portion 72A is in contact with the inner peripheral surface 7A of the sleeve member 7, the lateral vibration of the ball support member 72 is completely prevented. Further, in this embodiment, the orifice 73
Since the outer peripheral surface of the collar portion 72A is cut out, it is easy to form, and it is easy to perform accurate processing, and the accuracy of setting the damping force can be improved. Further, the orifice 73 has a collar 72.
Since it is formed on the outer peripheral surface of A, it is not closed by the end of the return spring 3.

FIG. 6A shows a relief valve 81 according to the third embodiment of the present invention. Further, FIG. 6B shows a cross-sectional view taken along line CC of FIG.

The relief valve 81 has a basic structure in common with the relief valve 1 of the first embodiment, and differs only in the points described below. Further, the relief valve 81 is incorporated in the spool 40 of the flow path switching valve 30 as in the relief valve 1 of the first embodiment.

Explaining the difference between the relief valve 81 and the relief valve 1, in the relief valve 81 of the present embodiment, the flange portion 82A of the ball support member 82 is made slightly wider in the axial direction and the outer peripheral surface thereof. Completely slidably contact the inner peripheral surface 7A of the sleeve member 7. On the outer peripheral surface of the collar portion 82A, a plurality of recessed portions 83 opening to the pressure control spring chamber 10 side are formed. Then, a plurality of orifices 84 axially penetrating the collar portion 82A are provided in the inner portion of each recess portion 83.

With this orifice 84, the relief valve 81 of the present embodiment can also obtain the same operational effect as the relief valve 1 of the first embodiment. Further, in the present embodiment, since the collar portion 82A is in contact with the inner peripheral surface 7A of the sleeve member 7, the lateral vibration of the ball support member 82 is completely prevented. Further, in this embodiment, the orifice 84
Is formed as a through hole that penetrates the collar portion 82A,
It is easy to form, it is easy to perform accurate processing, and the accuracy of setting the damping force can be improved. Further, since the orifice 84 is formed inside the hollow portion 83, even when the return spring 3 is installed at the end of the flange portion 82, it is not closed by the end of the return spring 3.

FIG. 7 shows a flow control valve 30 and a relief valve 91 incorporated in the flow control valve 30 according to the fifth embodiment of the present invention.

The present embodiment is different from the first embodiment except that the structure of the relief valve 91 is different from the structure of the relief valve 1 in the following points as compared with the first embodiment. Common.

The difference between the relief valve 91 and the relief valve 1 will be described. In the relief valve 91, an orifice having a damping action is formed on the outer periphery of the collar portion 92A of the ball support member 92, and the pressure control spring is further provided. The chamber 10 and the outer peripheral groove 13 are communicated not by the oil passage 12 but by the orifice 93.

As a result, when the relief valve 91 is pushed open, an appropriate back pressure is established in the pressure control spring chamber 10 by the flow through the orifice 93,
It is possible to suppress the influence of mixing of air and prevent the occurrence of cavitation in the pressure control spring chamber 10. Further, the operation of the ball support member 92 is stabilized, and the generation of abnormal noise due to the chattering phenomenon can be reduced. Further, since pressure is applied to the pressure control spring chamber 10 downstream of the seat hole 6B, the override characteristic can be improved.

FIG. 8 shows a flow rate control valve 30 and a relief valve 101 incorporated in this flow rate control valve 30 according to a sixth embodiment of the present invention.

In this embodiment, in the structure in which the pressure control spring chamber 10 and the outer peripheral groove 13 are communicated with each other by the orifice in the fifth embodiment (FIG. 7), a notched orifice 103 is formed on the outer periphery of the collar portion 102A. It was formed.
That is, in the present embodiment, the ball support member 10
The second flange portion 102A is brought into sliding contact with the inner peripheral surface 7A of the sleeve member 7, and a notched orifice 103 is formed on the outer periphery of the flange portion 102A. Further, the pressure control spring chamber 10 and the outer peripheral groove 13 communicate with each other via the orifice 104. With such a configuration, lateral vibration of the support member 102 can be more reliably prevented.

FIG. 9 shows a seventh embodiment of the present invention.

Compared to the first embodiment (FIG. 3) described above, this embodiment has a common structure relating to the relief valve 1, but has a hydraulic oil supply port 120 to the pump port P and the power steering device. Between the orifices 118
The difference is that the opening area of is variable by the solenoid valve 110.

More specifically, the spool 40 of the flow control valve 20 is provided with a small-diameter tip portion 46 on the tip end side of the sliding contact portion 43 which is in sliding contact with the sliding hole 31. The pump port P opens to the side of this tip portion 46. Also, the tank port T
Is opened to the side of the sliding contact portion 43, and is opened to the end portion 46 side when the spool 40 is retracted so that a part of the fluid from the pump port P is released to the tank port T. .

A solenoid valve 110 is arranged between the hydraulic oil supply port 120 communicating with the power steering device and the pump port P. Solenoid valve 110
Is a fixed iron core 112 having a coil 111 arranged on the outer circumference.
And a rod 114 around which a movable iron core is arranged. The rod 114 is slidably supported in the axial direction via bearings 115 and 116, and is driven by energizing the coil 111. The tip of the rod 114 fits into the opening of the diaphragm forming sheet. The outer peripheral portion of the rod 114 serves as an orifice 118, and the opening area of the orifice 118 is variable as the rod 114 moves back and forth.

With such a structure, the opening area of the orifice 118 between the pump port P and the hydraulic oil supply port 120 can be controlled more precisely.

The above embodiments can be used in any combination if possible.

In addition to the above-described embodiment, the present invention can take any form in which an orifice is provided downstream of the seat hole of the relief valve.

Further, in each of the above embodiments, the relief valve of the present invention is applied to the flow control valve of the vane pump for hydraulically supplying the power steering device, but the present invention is not limited to such a form, and any It is also effective for relief valves used for various purposes.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a vane pump showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view of a flow path switching valve and a relief valve showing the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of a flow path switching valve and a relief valve showing a second embodiment of the present invention.

FIG. 5A is a sectional view of a relief valve showing a third embodiment of the present invention, and FIG. 5B is a sectional view taken along line BB of FIG.

FIG. 6A is a sectional view of a relief valve showing a fourth embodiment of the present invention, and FIG. 6B is a sectional view taken along line CC of FIG.

FIG. 7 is a cross-sectional view of a flow path switching valve and a relief valve showing a fifth embodiment of the present invention.

FIG. 8 is a cross-sectional view of a flow path switching valve and a relief valve showing a sixth embodiment of the present invention.

FIG. 9 is a cross-sectional view of a flow path switching valve and a relief valve showing a seventh embodiment of the present invention.

FIG. 10 is a sectional view showing a conventional example of a flow path switching valve and a relief valve.

[Explanation of symbols]

1 relief valve 2 valve holes 3 Return spring 4 ball support member 4A collar part 5 balls 6 valve seats 6A seat orifice 6B sheet hole 7 Sleeve member 7A inner surface 9 chambers 10 Pressure control spring chamber 11 Orifice

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiichi Nagata 2-4-1, Hamamatsu-cho, Minato-ku, Tokyo World Trade Center Building Kayaba Industry Co., Ltd. (56) Reference JP-A-11-182456 (JP, A) ) JP-A-11-248019 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16K 17/04 B62D 5/07

Claims (3)

(57) [Claims] 1. A seat hole 6B opened in a valve seat 6 is formed.
Balls 5 to be opened and closed, and the balls 5 are supported from the opposite side of the valve seat 6.
Relief valve with ball support member 4
Te, provided at an end portion of the ball end of the ball support member 4
And a portion of the accommodating portion 62 for accommodating the ball support member 4
Formed in the guide recess 62A having a diameter larger than that of the guide recess 62A and a gap between the flange 4A and the guide recess 62A.
And a formed orifice 63 . 2. A seat hole 6B opened in the valve seat 6 is formed.
Balls 5 to be opened and closed, and the balls 5 are supported from the opposite side of the valve seat 6.
A relief valve having a ball support member 72
The ball support member 72 to the ball support portion.
The ball support member 72 is slidably contacted with the inner peripheral surface 7A of the accommodating portion, and the ball support member 72 is provided with a ball support on the outer peripheral surface.
A relief valve having a plurality of grooves 73 extending in the axial direction of the support member 72 . 3. A seat hole 6B opened in the valve seat 6 is formed.
Balls 5 to be opened and closed, and the balls 5 are supported from the opposite side of the valve seat 6.
And a ball support member 82 installed on the outer periphery of the ball support member 82.
Litter for urging the support member toward the valve seat 6 side
In the relief valve including the spring 3 and the ball support member 82,
The ball support member 82 is slidably contacted with the inner peripheral surface of the housing portion 82, and is disposed on the outer periphery of the ball support member 82.
A plurality of recesses 8 which are opened on the installation side of the spring 3
3 is provided, and the ball support member 82 is axially arranged in the recess 83.
A relief valve characterized in that a through hole 84 penetrating therethrough is formed .