JPS636536Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a sequence valve.

Conventionally, this type of valve has a cylindrical balance piston b which can be slid freely inside the valve casing a, as shown in the first diagram.
The sliding movement of the piston b is controlled by a relatively weak spring d in the chamber c behind it and a pilot valve e that opens due to the rise in pressure in the chamber c, and the flow between the inlet f and the outlet g of the valve housing a is controlled. There are known devices that control communication. With such a configuration, if the pressure at the inlet f fluctuates below the set pressure of the pilot valve e, the balance piston b cannot be kept open and stopped, resulting in communication between the inlet f and outlet g. This is not suitable for a hydraulic circuit in which it is desired that pressure fluid continues to flow once the pressure fluid has flowed into the outlet g. For example, in a circuit that uses multiple hydraulic motors to operate a winch for mooring a ship, the load pressure fluctuates greatly due to the effects of waves, etc. If a sequence valve is used in this circuit, the valve will repeatedly open and close. , it is desirable to have a continuous flow of pressurized fluid into the motor circuit, since variations in winch speed can result in dangerous mooring conditions.

The present invention provides a sequence valve that does not close after the balance piston slides to communicate between the inlet and the outlet unless the force due to the pressure at the inlet becomes lower than the elasticity of the spring that urges the balance piston. A slidable cylindrical balance piston 2 is provided in the valve housing 1 of the sequence valve, and the sliding movement of the piston 2 is controlled by the chamber 3 behind it.
In the valve housing 1, communication between the inlet 6 and the outlet 7 of the valve housing 1 is controlled by a spring 4 inside the valve housing 1 and a pilot valve 5 that opens due to an increase in pressure in the chamber 3.
A through hole 8 penetrating inside and outside is formed in the peripheral wall 2a of the balance piston 2, and when the balance piston 2 retreats against the spring 4, the chamber opens opposite to the through hole 8. 3 to the drain circuit.
It is formed by forming. One example is as shown in the second figure, in which a small hole 10 is formed in the balance piston 2 so that the pressure of the inlet 6 is guided to the chamber 3, and When the pressure in the chamber 3 rises, a poppet 11 of the pilot valve 5 opens against a spring 12 to connect the chamber 3 through a spring chamber 13 to an outlet 14 connected to a drain circuit.

When the balance piston 2 is in contact with the seat portion 15 to prevent communication between the inlet 6 and the outlet 7, the passage 9 is closed by its peripheral wall 2a, and the pilot valve 5 is opened to close the balance piston. 2 retreats against the spring 4, the passage 9 closes to the peripheral wall 2.
It communicates with the chamber 3 through the through hole 8 of a. To explain its operation, when the pressure at the inlet 6 increases and reaches the opening pressure of the pilot valve 5, the pilot valve 5 communicates with the chamber 3 through the small hole 10, which has the same pressure as the pressure at the inlet 6. The chamber 3 is opened by the pressure of Pressure fluid flows to 7. So this balance piston 2
When the chamber 3 retreats, the chamber 3 is further connected to the drain circuit via the through hole 8 and the passage 9 in the peripheral wall 2a of the balance piston 2, so that the pressure at the inlet 6 becomes lower than the opening pressure of the pilot valve 5, and this is closed. Even when the pressure in the chamber 3 becomes low, the pressure in the chamber 3 remains at the low pressure in the drain circuit, and the balance piston 2 is maintained in the retracted state. When the pressure at the inlet 6 becomes lower than the pressure corresponding to the elasticity of the spring 4, or when the force acting on the back of the balance piston 2 increases by applying pressure to the drain circuit, etc., the balance piston 2 2 moves back and the inlet 6 and outlet 7 are no longer communicated with each other.

In this way, according to the present invention, a through hole 8 is formed in the peripheral wall 2a of the balance piston 2 of the sequence valve, and when the piston 2 retreats, the chamber 3 is connected to the passage 9 connected to the drain circuit through the through hole 8. Therefore, even if the pressure at the inlet 6 drops below the opening pressure of the pilot valve 5, the balance piston 2 does not easily close the communication between the inlet 6 and the outlet 7, and the outlet 7 It is convenient to be able to continuously obtain pressurized fluid and keep the hydraulic circuit connected to the outlet 7 active, and its structure is relatively simple and can be manufactured and improved at low cost.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional sequence valve;
The figure is a cutaway side view of an embodiment of the present invention. 1...Valve housing, 2...Balance piston, 3...
Chamber, 4... Spring, 5... Pilot valve, 6... Inlet, 7... Outlet, 8... Through hole, 2a... Peripheral wall, 9... Passage.

Claims (1)

[Scope of utility model registration request] A slidable cylindrical balance piston 2 is provided in the valve housing 1 of the sequence valve, and the sliding movement of the piston 2 is controlled by a spring 4 in a chamber 3 behind the piston 2 and a pilot valve 5 which is opened by an increase in pressure in the chamber 3. The peripheral wall 2a of the balance piston 2 controls the communication between the inflow port 6 and the outflow port 7 of the valve housing 1.
A through hole 8 passing through the valve housing 1 is formed in the valve housing 1.
A sequence valve comprising a passage 9 which faces the through hole 8 and communicates the chamber 3 with a drain circuit when the balance piston 2 retreats against the spring 4.