JPH04138168U - directional valve - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a directional control valve in which a poppet-shaped seal member seals a discharge valve seat at a substantially constant position regardless of fluctuations in fluid pressure. [Structure] On the outer circumferential surface of poppet-shaped second seal members 20, 20 that seal the discharge valve seats 8, 8 provided in the valve portion 1, a presser portion 10a provided on the pistons 10, 11 that drive the valve rod 12, 11a are brought into contact with each other. [Effect] Since the poppet-shaped second seal member does not expand in diameter due to fluid pressure, it seals the discharge valve seat at a substantially constant position.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a directional control valve used in industrial equipment that utilizes fluid pressure.

0002

[Conventional technology]

Pressure fluid supply ports, output ports, and discharge ports; A valve hole, a discharge valve seat formed between the output port and the discharge port of the valve hole, and a valve seat that slides into the valve hole. a first seal member movably inserted to cut off communication between the supply port and the output port; A poppet-shaped second seal member is fitted to open and close the discharge valve seat from the discharge port side. A valve portion having a valve stem and pistons attached to both axial ends of the valve stem, and the piston. A directional control valve equipped with a fluid pressure drive unit that applies fluid pressure to the ton is particularly exemplified. Already known. In order to make the stroke of the valve stem constant in this directional valve, it is necessary to A poppet-shaped second seal member that opens and closes the discharge valve seat seals the discharge valve seat at a fixed position. It is necessary to However, when the fluid pressure of the fluid in the valve section increases, the above-mentioned directional control valve Because the diameter of the poppet-shaped seal member expands, the seal position is likely to change. There's a problem.

0003

[Problem that the idea aims to solve]

The problem to be solved by this invention is to provide a poppet-shaped system that can be used regardless of fluid pressure fluctuations. To provide a directional control valve in which a discharge valve seat can be sealed at a substantially constant position by a valve member. be.

0004

[Means to solve the problem]

In order to solve the above problems, the present invention provides a pressure fluid supply port, an output port and Exhaust ports, the valve holes through which these ports open, and the output ports and exhaust ports of the valve holes. A discharge valve seat formed in between is slidably inserted into the valve hole, and is connected to the supply port and the output port. A popper that opens and closes the first seal member that cuts off communication between the ports and the discharge valve seat from the discharge port side A valve stem fitted with a second seal member in the shape of a cutter, and attached to both ends of the valve stem in the axial direction. a valve portion having a piston; and a fluid pressure drive portion that applies fluid pressure to the piston. In the directional control valve, the piston on the discharge port side is connected to the second seal. It is characterized by being equipped with a presser part that comes into contact with the outer peripheral surface of the member and prevents the diameter from expanding. Ru.

[0005]

[Effect]

The second seal member is held down by the holding part of the discharge side piston that comes into contact with the outer peripheral surface. Therefore, the diameter does not expand due to fluid pressure, so even if the fluid pressure fluctuates, the second seal member will not be discharged. The seal position on the valve seat is constant.

[0006]

【Example】

The figure shows an embodiment of the present invention, and this directional control valve includes a valve part 1 and a fluid pressure operating part. It is equipped with a pilot valve 2. The valve portion 1 includes a valve body 4 and end plates 5 and 6 on both sides of the valve body 4 in the axial direction. The main body 4 includes a pressure fluid supply port P, output ports A and B, and a discharge port EA. EB and an axial valve hole 7 through which these ports open are formed. Discharge valve seats 8, 8 are formed between the output ports A, B and the discharge ports EA, EB. ing. Further, sleeves 9a, 9b are provided between the end plates 5, 6 and both ends of the valve hole 7. is fitted, and the inner diameter of the sleeve 9b is smaller than the inner diameter of the sleeve 9a. Pistons 10 and 11, which slide airtightly over these sleeves 9a and 9b, open the valve hole 7. It is integrally slidably attached to both ends of the sliding valve stem 12 with mounting bolts, and Pressure chambers 13 and 14 are formed between the hand plates 5 and 6 and the pistons 10 and 11. Ru.

[0007] The valve stem 12 includes a valve stem main body 16 and a stem fitted into the axial center of the main body 16. a spool-shaped first sealing member 18 fitted sequentially to both sides of the pacer 17; 18, seal member presser rings 19, 19, and poppet-shaped second seal members 20, 2 0, and these seal members are made of an elastic material such as synthetic rubber. There is. The first seal members 18, 18 are connected to ports P and A by sliding of the valve stem 12. and a second seal that opens and closes the discharge valve seats 8 and 8. The valve seat sealing surfaces of the members 20, 20 are inclined inward toward the center of the valve stem body 16. ing. Further, the pistons 10 and 11 are provided with outer peripheries of second seal members 20 and 20. Holding parts 10a and 11a that come into contact with the surface to prevent the diameter from expanding, and ventilation holes 10b... 11b... are formed. These ventilation holes 10b, . . . and 11b, . The second seal members 20, 20 are attached to the valve stem body 1 along with the grooves on the sides of the valve stem members 20, 20. 6, this prevents air from being trapped.

[0008] On the other hand, the pilot valve 2 as a fluid pressure drive unit is used to excite the solenoid 2a. The pilot inlet port 23 and pilot outlet port 24 communicate with each other, and the solenoid The pilot outlet port 24 and the pilot exhaust port 25 are It is configured as a well-known 3-port solenoid valve that communicates with the pilot inlet port. The port 23 has a pilot outlet in a pressure accumulating chamber 27 which communicates with the supply port P through a passage 26. The mouth port 24 is connected to the pressure chamber 13, and the pilot exhaust port 25 is connected to the end plate 5. The pressure chamber 14 is connected to the pressure accumulation chamber 27 through a passage 28 to the opened exhaust port E. They are connected to each other. Reference numerals 30 and 30 in the figure are guide rings for the pistons 10 and 11.

[0009] In the above embodiment, when the solenoid 2a of the pilot valve 2 is de-energized, In this case, fluid is supplied to the pressure chamber 14 from the pressure accumulation chamber 27, and fluid in the pressure chamber 13 is supplied to the pressure chamber 14. is discharged from the exhaust port E, so the pistons 10, 11 and the valve stem 12 are port P and B and A and EA communicate with each other, and ports P and A and EA communicate with each other. The communication between B and EB is cut off (see the upper half of the valve stem 12). When the solenoid 2a is excited, the pilot fluid pressure supplied to the pressure chamber 13 Therefore, the pistons 10, 11 and the valve stem 12 move to the right in the figure, and the ports P, A, and Ports B and EB communicate with each other, and communication between ports P and B and A and EA is cut off. (See also bottom half). Due to the reciprocating movement of the valve stem 12, the fluid flowing between ports P and A and between P and B is Although the fluid pressure acts in the direction of expanding the diameter of the second seal members 20, 20, the second seal The members 20, 20 are held by the holding parts 10a, 11a provided on the pistons 10, 11. Diameter expansion is prevented. Therefore, even if the fluid pressure of the fluid flowing through the valve part 1 fluctuates, the 2 sealing members 20, 20 are capable of sealing the discharge valve seats 8, 8 at a certain position. I can do that.

0010 Note that the directional control valve of the present invention is not limited to a 5-port valve, and may be a fluid pressure driven valve. The moving part is also not limited to the pilot valve.

[0011]

[Effect of the idea]

The directional control valve of the present invention has a poppet-shaped second seal member that opens and closes the discharge valve seat. Fluid pressure fluctuates because diameter expansion is prevented by the retaining part installed on the piston on the discharge side. Since the discharge valve seat can always be sealed in the same position even when the valve is closed, the valve stem stroke can be kept constant can do.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an embodiment.

[Explanation of symbols]

1 Valve part, 2 Pilot valve, 7 Valve hole, 8 Discharge valve seat, 10, 11 Piston, 10a, 11a Holding part, 12 Valve stem, 18 First seal member, 20
2nd seal member, P supply port, A, B output port, EA, EB discharge port.

Claims (1)

[Scope of utility model registration request] Claim 1: A pressure fluid supply port, an output port, and a discharge port, a valve hole through which these ports open, a discharge valve seat formed between the output port and the discharge port of the valve hole, and a valve seat that slides into the valve hole. a valve stem that is fitted with a first seal member that can be inserted so as to cut off communication between the supply port and the output port, and a poppet-shaped second seal member that opens and closes the discharge valve seat from the discharge port side; and the valve stem. In the directional control valve, the piston on the discharge port side is connected to the outer periphery of the second sealing member. A directional control valve characterized in that it is provided with a holding part that comes into contact with a surface and prevents diameter expansion.