JPH0624276U - Relief valve - Google Patents

Abstract

(57) [Abstract] [Purpose] To facilitate production and improve the control performance of the gradual relief setting pressure. [Structure] The valve body 6 is provided with a plurality of pilot chambers 7 and 9, and the valve bodies 2 and 3 are provided with pressure receiving surfaces 2C and 3C facing the respective pilot chambers 7 and 9 at a plurality of positions. It is characterized in that the relief setting pressure can be switched stepwise by selectively introducing the control fluid.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a relief valve used in, for example, a control device for oil or pneumatic equipment, and more particularly to a structure for gradually changing a relief set pressure.

[0002]

[Prior art]

 As a conventional relief valve of this type, for example, there is a variable relief valve using a proportional solenoid or the like, but when changing the relief set pressure at a large ratio of 1/10 to 1/100 or controlling high pressure. However, in order to balance the suction force and pressure of the solenoid, a large solenoid was required, and the control accuracy of the relief set pressure sometimes became a problem.

[0003]

[Problems to be solved by the device]

 In contrast to the above-mentioned conventional technology, when it is not necessary to continuously control the relief set pressure as in the relief valve described above but only stepwise control of the relief set pressure is required, a smaller solenoid can be used with high accuracy. It may be required to switch the relief set pressure.

The present invention meets the above-mentioned requirements, and an object of the present invention is to provide a relief valve capable of facilitating the production and improving the stepwise control of the relief setting pressure. Especially.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, the relief port provided in the valve body can be opened and closed by the movement of the valve body reciprocally inserted in the hollow internal valve body. The valve body is provided with an urging means for urging the valve body in one direction, and a pilot chamber for applying a pressure of the control fluid to the valve body in a direction opposing the urging force of the urging means. , If the fluid pressure is below the specified relief setting pressure, the relief port is kept closed.If the fluid pressure exceeds the relief setting pressure, the valve element moves against the urging force of the urging means to open the relief port and apply pressure. In the relief valve for releasing, by providing a plurality of pilot chambers in the valve body, providing pressure receiving surfaces facing each pilot chamber in the valve body at a plurality of locations, and selectively introducing a control fluid into the pilot chambers. , Re Characterized in that the stepwise switchable to-safe set pressure.

[0006]

[Action]

 In the relief valve having the above structure, the valve body is provided with a plurality of pilot chambers, the valve body is provided with a plurality of pressure receiving surfaces facing the respective pilot chambers, and the control fluid is selectively introduced into the pilot chambers. As a result, the relief setting pressure can be switched in stages, so the relief setting pressure can be switched simply by changing the number of pilot chambers and the area of the pressure receiving surface. Therefore, the manufacturing can be facilitated, and the control performance of the relief setting pressure can be improved.

[0007]

【Example】

 The present invention will be described below based on the illustrated embodiment. In FIG. 1 showing a relief valve according to an embodiment of the present invention, reference numeral 1 denotes a relief valve main body, which is configured to change the relief relief setting pressure in stages.

The relief valve 1 has a schematic structure in which a spool 2 as a valve body, a pin 3, a guide hole 4 into which the spool 2 is inserted, and a guide hole 4 into which the pin 3 is inserted have different diameter guides. A housing 6 as a valve body having a hole 5, a solenoid valve 8 for introducing a control fluid into a first pilot chamber 7 provided at the other end of the spool 2, and a second pilot chamber provided at the other end of the pin 3. And a pump 10 for introducing a control fluid into the valve 9.

A guide hole 4 is provided inside the housing 6, and a step portion 11 is provided at an end portion of the guide hole 4 so as to be coaxial with the guide hole 4 and have a smaller diameter than the guide hole 4. A different diameter guide hole 5 is provided to close the part.

The spool 2 is slidably inserted into the inner periphery of the guide hole 4, and a closing member 12 for closing the opening of the guide hole 4 is fluid-tightly fitted and fixed to one end of the spool 2. There is. A spring 13 as a biasing means is mounted between one end of the spool 2 and the closing member 12. The spring 13 has one end in contact with the closing member 12 and the other end in contact with one end of the spool 2 to bias the spool 2 toward the pin 3 side. Further, a first pilot chamber 7 is formed between the other end surface 2C of the spool 2 and the step portion 11 of the guide hole 4 at the other end of the spool 2 in the direction opposite to the spring force of the spring 13, and the other end surface 2C is formed. Is a pressure receiving surface facing the first pilot chamber 7.

Then, the pin 3 is slidably inserted into the inner circumference of the different diameter guide hole 5, one end of the pin 3 abuts on the other end of the spool 2, and the pin 3 in a direction counteracting the spring force of the spring 13. A second pilot chamber 9 is formed at the other end of the pin 3 between the other end surface 3C of the pin 3 and the closed portion of the different diameter guide hole 5, and the other end surface 3C is a pressure receiving surface facing the second pilot chamber 9. .

On the other hand, the housing 6 has a first passage 14 through which the first pilot chamber 7 and the solenoid valve 8 communicate, a second passage 15 through which the second pilot chamber 9 and the pump 10 communicate, and a guide hole 4. A P port 16 as an outflow port, a D port 17 as a relief port, and a port 18 for adjusting the pressure between the spool 2 in which the spring 13 is interposed and the closing member 12 are provided.

An annular groove 2A is provided on the outer periphery of the spool 2, the P port 16 is always open to face the groove 2A, and the D port 17 is larger than the groove 2A of the spool 2. It is opened and closed by the land portion 2B on the one end side so that the P port 16 and the D port 17 are communicated with each other and are not communicated with each other.

As shown by the symbol in the circuit diagram shown in FIG. 1, the solenoid valve 8 is connected to a flow passage A19 communicating with the first passage 14 provided in the housing 6 and a flow passage B21 communicating with the oil tank 20. It is peeling. The flow passage B21 is provided with a flow passage C22 communicating with the D port 17 provided in the housing 6 and a flow passage D23 communicating with the port 18 provided in the housing 6 in a continuous state. The solenoid valve 8 is normally open.

Further, in the pump 10, a flow passage E 24 communicating with the second passage 15 provided in the housing 6, a flow passage F 25 communicating with the first passage 14 provided in the housing 6, and a P port provided in the housing 6. The flow path G26 leading to 16 is provided in a continuous state.

An orifice 27 is provided in the flow path F25, and the flow path A19 is connected to the orifice 27. Since the flow passage F25 and the flow passage A19 are connected to each other in this manner, the introduction of the pilot pressure of the control fluid into the first pilot chamber 7 can be cut by the orifice 27 and the solenoid valve 8. .

The relief setting pressure is determined by the balance between the spring force in the set load of the spring 13 and the pilot pressure applied to the other end surface 3C of the pin 3 and the other end surface 2C of the spool 2, and when the pilot pressure increases, When the spool 2 moves toward the closing member 12 side against the spring force of the spring 13, the land portion 2B moves and the D port 17 opens, and the P port 16 and the D port via the groove 2A. 17 and communicate with each other for relief.

In the state of FIG. 1, the pilot pressure is applied only to the other end surface 3C of the pin 3, and when the solenoid valve 8 is turned on, the pilot pressure is applied to the other end surface 2C of the spool 2 as well. Become. That is, the relief set pressure is changed stepwise by the ratio of the cross-sectional area of the pin 3 and the spool 2 depending on ON / OFF of the solenoid valve 8. For example, if the ratio of the diameters of the pin 3 and the spool 2 is 1:10, the change of the relief set pressure of 1: 100 can be controlled.

In the relief valve having the above-mentioned configuration, since the control fluid introduction to the first pilot chamber 7 and the control fluid introduction to the second pilot chamber 9 are switched by turning on / off the solenoid valve 8, the relief valve is provided. The set pressure changes stepwise depending on the ratio of the cross-sectional areas of the spool 2 and the pin 3 to which the pilot pressure of the control fluid is applied. Therefore, the relief setting pressure can be changed stepwise by the ratio of the diameters of the spool 2 and the pin 3, so that the manufacturing is easy and the change of the relief setting pressure can be controlled accurately.

FIG. 2 shows another embodiment of the present invention. The present embodiment is different from the first embodiment in that two guide holes 4A and 5B having different diameters and different diameters from the guide hole 4 which are provided continuously to the guide hole 4 are provided at a predetermined interval on the axis line. ing. Of the two different diameter guide holes 5A and 5B, one different diameter guide hole 5A is located on the upper side in FIG. 2 and has a larger diameter than the different diameter guide hole 5 shown in FIG. The guide hole 5B is located on the lower side in FIG. 2 and has a smaller diameter than the different diameter guide hole 5 shown in FIG. Accordingly, the pin I 3A slidably inserted in the different diameter guide hole 5A has a cross sectional area S2, and the pin II 3B slidably inserted in the different diameter guide hole 5B has a cross sectional area S1. Has become.

A first pilot chamber I 9A is provided at the other end of the pin I 3A, the other end surface 3D is the pressure receiving surface of the first pilot chamber I 9A, and the other end of the pin II 3B is A second pilot chamber II9B is provided, and the other end surface 3E is the pressure receiving surface of the second pilot chamber II9B. Therefore, as shown in FIG. 1, the first pilot chamber 7 is not provided at the other end of the spool 2, and accordingly, the first passage 14 is not provided in the housing 6.

Further, the housing 6 is provided with a second passage I 15A through which the second pilot chamber I 9A and the pump 10 communicate, and a second passage II 15B through which the second pilot chamber II 9B and the pump 10 communicate. There is.

The pump 10 has a flow passage H 28 communicating with the second passage I 15 A provided in the housing 6, a flow passage I 29 communicating with the second passage II 15 B provided in the housing 6, and a P port 16 provided in the housing 6. It is provided in a state where the flow path J30 leading to the. Further, the channels H28 and I29 are provided with orifices I, II27A, and 27B, respectively.

The second pilot chambers I, II 9A, 9B are provided with solenoid valves II, I 8B, 8A for introducing the control fluid, respectively, and operate in the same manner as the solenoid valve 8 of the first embodiment. Has become. The solenoid valve II8B is connected with a flow passage K31 communicating with the flow passage H28 and a flow passage L32 communicating with the oil tank 20, and the solenoid valve I8A is connected with a flow passage M33 communicating with the flow passage I29 and the oil tank 20. Is connected to a flow path N34 leading to. In addition, the flow path L32, the flow path N34, the flow path C22, and the flow path D23 are connected to each other, and are connected to the oil tank 20.

Due to such a configuration, the cross-sectional areas S2 and S1 of the two pins I, II 3A, 3B having different diameters are set. Therefore, only the solenoid valve I 8A is turned on. Only solenoid valve II8B is ON, and solenoid valves I, II8A, 8B are ON, and the relief setting pressure ratio is switched to S1: S2: S1 + S2.

In the relief valve having the above structure, since the two pins I, II 3A, 3B having different diameters are used, the relief setting pressure can be switched in three stages. That is, the number of switching steps can be easily increased by increasing the number of pins. Since other configurations and operations are the same as those of the first embodiment, the same components are designated by the same reference numerals and the description thereof will be omitted.

In the second embodiment, the number of pins is not limited to two, but may be any number according to the number of switching stages. Further, the diameters of the respective pins are not limited to different diameters, but may be the same diameter.

Further, in each of the above-mentioned embodiments, two pilot chambers have been described as an example, but the number of pilot chambers is not limited to two and may be three or four, and a plurality of pilot chambers may be provided.

[0029]

[Effect of device]

 The present invention has the above-described configuration and operation, and in addition to providing a plurality of pilot chambers in the valve body, providing pressure receiving surfaces facing each pilot chamber in the valve body at a plurality of locations, and selecting a control fluid in the pilot chamber. Since the relief setting pressure can be switched stepwise by changing the number of pilot chambers and the area of the pressure receiving surface, the relief setting pressure can be switched. Therefore, the manufacture can be facilitated and the control performance of the relief set pressure can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a relief valve according to an embodiment of the present invention.

FIG. 2 is a sectional view of an essential part of a relief valve according to another embodiment of the present invention.

[Explanation of symbols]

 1 Relief valve 2 Spool (valve body) 2A Groove 2B Land portion 2C Other end surface (pressure receiving surface) 3 Pin (valve element) 3A Pin I (valve element) 3B Pin II (valve element) 3C Other end surface (pressure receiving surface) 3D The other end surface (pressure receiving surface) 3E The other end surface (pressure receiving surface) 4 Guide holes 5, 5A, 5B Different diameter guide holes 6 Housing (valve body) 7 First pilot chamber 8 Solenoid valve 8A Solenoid valve I 8B Solenoid valve II 9 Second Pilot room 9A Second pilot room I 9B Second pilot room II 10 Pump 11 Step 12 Closing member 13 Spring (biasing means) 14 First passage 15 Second passage 15A Second passage I 15B Second passage II 16 P port 17 D port (relief port) 18 port 19 flow path A 20 oil tank 21 flow path B 22 flow path C 23 flow path D 24 flow path E 25 flow path F 2 6 Channel G 27 Orifice 27A Orifice I 27B Orifice II 28 Channel H 29 Channel I 30 Channel J 31 Channel K 32 Channel L 33 Channel M 34 Channel M 34 Channel N

Claims (1)

[Scope of utility model registration request] 1. A relief port provided in the valve body can be opened and closed by moving a valve body that is reciprocally inserted into an internally hollow valve body, while the valve body is provided with the valve body. A pilot chamber is provided that applies a control fluid pressure to the valve body in a direction that opposes the biasing force of the biasing means.When the fluid pressure is less than a predetermined relief setting pressure, the relief pressure is set. In a relief valve that holds the port in a closed state and when the relief set pressure is exceeded, the valve body moves against the biasing force of the biasing means to open the relief port and release the pressure. A plurality of pressure receiving surfaces facing each pilot chamber are provided in the valve body, and the control fluid is selectively introduced into the pilot chamber, whereby the relief set pressure can be switched stepwise. Relief valve, wherein the door.