JP3509284B2 - Pressure reducing valve - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure reducing valve which is attached to a piping system for steam, compressed air, liquid or the like to maintain a fluid pressure on an outlet side at a constant set pressure. Normally, a pressure reducing valve is installed immediately before a device that uses a fluid such as steam or compressed air to reduce the pressure of the fluid and supply it to the optimal pressure for the device, thereby improving the operating efficiency and productivity of the device. Things.
In this pressure reducing valve, when a small pressure reducing ratio is set, stable pressure reduction can be performed with a single pressure reducing valve, but when the pressure reducing ratio is large, chattering occurs and the setting cannot be performed. Was. [0002] Therefore, conventionally, when a large pressure reduction ratio is set, a plurality of pressure reduction valves are connected in series to sequentially reduce the pressure of a fluid. This is achieved by reducing the pressure of the high-pressure fluid with the first pressure reducing valve and further reducing the pressure of the reduced pressure fluid with the second pressure reducing valve, or, if necessary, with the third and subsequent pressure reducing valves. By doing so, a large pressure reduction ratio can be set. [0003] In the conventional multi-stage pressure reduction using a plurality of pressure reducing valves, if the pressure reducing valve installed in the preceding stage cannot be closed, the fluid flows in without being reduced in pressure. This causes chattering. [0004] Accordingly, it is an object of the present invention to provide a pressure reducing valve which can maintain the outlet side pressure at a predetermined low pressure without chattering when the preceding pressure reducing valve cannot be closed. The technical means of the present invention taken to solve the above problems is to provide a valve port between an inlet and an outlet, and to control the outlet side pressure through an outlet pressure communication passage. A pressure receiving member for receiving pressure is arranged on one side through the pressure receiving means, and a pressure setting means is attached to the other side of the pressure receiving member, and the pressure receiving member detects that the outlet side pressure is lower than the set pressure, and the valve port is closed. In the pressure reducing valve that supplies the inlet side pressure to the outlet side through the outlet side and maintains the outlet side pressure at the set pressure, a bypass passage that bypasses the inlet side to one side of the pressure receiving response member is provided, and a sub valve port is provided in the bypass passage. A sub-pressure receiving member for receiving pressure on one side through the primary pressure communication passage is provided on the inlet side, and a sub-pressure setting means is mounted on the other side of the sub-pressure receiving member, so that the inlet pressure is set to the pre-stage pressure reducing valve. When the pressure rises by a predetermined value, the The material is detected, and the pressure on the inlet side is supplied to one side of the pressure receiving responsive member through the sub-valve port. In the pressure reducing valve of the present invention, when the upstream pressure reducing valve is unable to close and the inlet pressure rises by a predetermined value from the set pressure of the upstream pressure reducing valve, the secondary pressure receiving response member responds and the secondary valve operates. Open your mouth,
Inlet pressure is supplied to one side of the pressure receiving responsive member via the bypass passage. As a result, the pressure-responsive member responds to shut off the valve port between the inlet and the outlet, thereby preventing chattering. Then, a part of the inlet pressure supplied to one side of the pressure receiving member is supplied to the outlet via the outlet pressure communication passage. At this time, the outlet side pressure is maintained at a predetermined low pressure by reducing the flow rate in the outlet pressure communication passage because the outlet pressure communication passage is usually smaller in diameter than the inlet and outlet pipe diameters and the valve diameter.
If the outlet side pressure cannot be maintained at a predetermined low pressure when the pre-stage pressure reducing valve cannot be closed, the flow path to the outlet pressure communication passage is limited within a range that does not deteriorate the response when the pressure receiving responsive member receives the outlet side pressure. An orifice member for reducing the pressure can be interposed. An embodiment showing a specific example of the above technical means will be described (see FIG. 1). An inlet 11 and an outlet 12 are formed in the valve casing 10, and a valve port 14 is provided in a valve seat member 13 attached to the valve casing 10. The inlet 11 is connected to the inlet pipe 1, and the outlet 12 is connected to the outlet pipe 2. [0008] A flat valve body 16 is opposed to the valve port 14,
The valve is urged in the valve closing direction by a spring 18 via a valve body guide member 17, and is connected to a connection rod 20 of a piston 19 at an upper portion thereof. A hemispherical portion 21 is provided between the piston 19 and the connecting rod 20.
To form The upper part of the piston 19 is connected to a pilot valve chamber 23 through a communication passage 22. A pilot valve body 25 is disposed at the end of the pilot valve chamber 23 by being biased by a spring 26 in a valve closing direction. The pilot valve body 25 communicates with the inlet 11 through an inlet pressure communication passage 27. Pilot valve 2
5 is connected to a diaphragm 29 as a pressure-receiving member by connecting a pilot valve rod 28 to the upper part. Diaphragm 2
The lower surface chamber 30, which is one side of 9, receives a pressure on the outlet 12 side through an outlet pressure communication passage 31. The orifice member 15 that narrows the flow path is disposed in the outlet pressure communication path 31. A coil spring 33 as pressure setting means is provided on the other side of the diaphragm 29.
Place. A pressure adjusting screw 3 is provided at the upper end of the coil spring 33.
6 is attached. A bypass passage 3 branching from the inlet pressure communication passage 27 and communicating with the lower surface chamber 30 of the diaphragm 29;
An auxiliary valve port 51 is provided in the bypass passage 3. Secondary valve 5
The sub-valve element 52 is urged in the valve opening direction by a spring 53 so as to face the sub-element 1, and is joined to a sub-diaphragm 54 as a sub-pressure receiving responsive member at an upper portion thereof. The pressure on the inlet 11 side acts on the sub lower surface chamber 55 which is one side of the sub diaphragm 54 via the primary pressure communication passage 7. The upstream pressure reducing valve 5 is disposed in the inlet pipe 1 on the upstream side of the primary pressure communication passage 7. Secondary diaphragm 5
On the other side of 4, a setting spring 57 as sub-pressure setting means is arranged. A setting screw 58 is attached to the upper end of the setting spring 57. By rotating the setting screw 58, the setting spring 5
The spring load of 7 changes, and the urging force on the other side of the sub diaphragm 54 is adjusted. The urging force of the sub-diaphragm 54 to the other side is such that when the pressure on the inlet 11 side rises by a predetermined value above the set pressure of the pre-stage pressure reducing valve 5, the sub-valve element 52
Adjust so that 1 is open. The operation is as follows. When the pre-stage pressure reducing valve 5 performs a normal opening / closing valve operation, the pressure on the inlet 11 side does not increase beyond a pressure obtained by adding a predetermined value to the set pressure of the pre-stage pressure reducing valve 5, and the sub-valve 52 closes. The auxiliary valve port 51 is closed. When the pressure on the outlet 12 side becomes lower than the pressure set by the coil spring 33, the pilot valve body 25 is opened via the pilot valve rod 28 by the spring force of the coil spring 33, and the high-pressure fluid on the inlet 11 side communicates with the communication passage 27, Acting on the upper surface of the piston 19 through 22, the piston 19 is displaced downward. The displacement of the piston 19 causes the valve body 16 to open and replenish the outlet 12 with high-pressure fluid at the inlet 11, thereby increasing the pressure at the outlet 11 to a set pressure.
When the pressure reaches the set pressure, the load for pushing up the diaphragm 29 upward and the load for pushing down the diaphragm by the coil spring 33 are balanced so that the pilot valve body 25 is closed and the valve body 16 is also closed. When the pre-stage pressure reducing valve 5 cannot be closed, the inlet 1
The pressure on the first side rises above a pressure obtained by adding a predetermined value to the set pressure of the pre-stage pressure reducing valve 5. This pressure increase causes the sub-diaphragm 54 to respond, opening the sub-valve element 52 and opening the sub-valve port 51. The inlet pressure on the inlet pressure communication passage 27 side is supplied to the lower surface chamber 30 of the diaphragm 29 via the bypass passage 3 by the opening of the sub-valve port 51. Thereby, the diaphragm 29
Responds and closes the valve port 14. A part of the pressure on the inlet side supplied to the lower surface chamber 30 of the diaphragm 29 is supplied to the outlet 12 side via the outlet pressure communication passage 31, and the pressure on the outlet 12 side is maintained at a predetermined low pressure. As described above, according to the present invention, when the pre-stage pressure reducing valve cannot be closed, the outlet side pressure can be maintained at a predetermined low pressure without chattering. Does not adversely affect the valve.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a piping configuration diagram of two-stage pressure reduction using a pressure reducing valve of the present invention. [Description of Signs] 1 Inlet piping 2 Outlet piping 3 Bypass passage 5 Pre-stage pressure reducing valve 7 Primary pressure communication passage 11 Inlet 12 Outlet 14 Valve port 15 Orifice member 16 Valve 27 Inlet pressure communication passage 29 Diaphragm 30 Lower surface chamber 31 Outlet pressure communication passage 33 Coil spring 51 Sub-valve port 52 Sub-valve 54 Sub-diaphragm 55 Sub-bottom chamber 57 Setting spring

Claims (1)

(57) [Claim 1] A valve port is provided between an inlet and an outlet, and a pressure receiving responsive member that receives pressure on the outlet side to one side via an outlet pressure communication passage is disposed, and a pressure receiving responsive member is provided. A pressure setting means is attached to the other side, the pressure receiving responsive member detects that the outlet side pressure is lower than the set pressure, and supplies the inlet side pressure to the outlet side via the valve port, thereby reducing the outlet side pressure. In the pressure reducing valve that maintains the set pressure, a bypass passage that bypasses the inlet side to one side of the pressure receiving response member is provided, a sub-valve port is provided in the bypass passage, and the inlet side pressure is received to one side through the primary pressure communication passage. The auxiliary pressure response member is disposed, and the auxiliary pressure setting means is attached to the other side of the auxiliary pressure response member, and the auxiliary pressure response member detects that the inlet side pressure has risen by a predetermined value from the set pressure of the preceding pressure reducing valve, Inlet pressure is supplied to one side of the pressure receiving responsive member via the auxiliary valve port Pressure reducing valve characterized by Rukoto.