JPH04367912A - Automatic setting pressure reducing valve - Google Patents

Abstract

PURPOSE:To obtain the automatic setting pressure reducing valve whose structure is simple by controlling an electric conduction to an exciting coil by a specific control means. CONSTITUTION:A magnet 15 is attached to the upper face of a diaphragm 14, a fixed iron core 17 is attached so as to be opposed to the magnet 15 to a case 16, and an exciting coil, 18 is placed in its periphery. An electric conduction to the exciting coil 18 is controlled by a control means. The control means stores in advance a function relation of a current value to the exciting coil 18 and set pressure. The lower face of the diaphragm 14 faces a diaphragm chamber 20 through a secondary side detection passage 19 for communicating with an outlet 2. In such a state, when an arbitrary pressure value to be set is inputted, the control means calculates a current value, based on the function relation, and controls a current value subjected to electric conduction to the exciting coil 18. When the electric conduction to the exciting coil 18 is executed, magnetic force is generated on the face of the fixed iron core 17 which faces the magnet 15, and as a current increases, repulsion increases. By this repelling power, force worked on one face of the diaphragm is set.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve for controlling the pressure of a fluid, and more particularly to a pressure reducing valve that reduces the pressure of a fluid on the primary side so as to maintain a constant pressure on the secondary side. The pressure reducing valve is
The main valve is operated directly by the displacement of a pressure-responsive member such as a diaphragm or bellows, or the main valve such as a piston valve is indirectly operated by operating a pilot valve. The fluid pressure on the next side is applied to the other side by the elastic force of the pressure setting spring. When setting the pressure on the secondary side,
This is done by manually rotating the adjustment screw that adjusts the elastic force of the pressure setting spring. Therefore, it is extremely inconvenient to frequently change the set pressure, and remote control or automatic control is not possible.

0002

[Prior Art] Therefore, an automatic setting pressure reducing valve in which an adjusting screw is automatically rotated was proposed in Japanese Patent Application Laid-Open No. 63-20603.
It is shown in the publication No. This involves attaching an electric motor to the pressure reducing valve to drive its adjusting screw, providing a position detecting means for detecting the displacement of the adjusting screw, storing in advance the functional relationship between the displacement of the adjusting screw and the set pressure, and detecting the position by the position detecting means. A control means is provided for controlling the drive of the electric motor based on the signal. When an arbitrary setting pressure to be set is input, the control means rotates the electric motor based on the functional relationship, and stops the electric motor when the position detection means detects that the adjustment screw has been displaced to the position where it should be stopped. urge

0003

[Problems to be Solved by the Invention] In the above system, in order to set the force acting on one surface of the diaphragm, a pressure setting spring, an adjustment screw, and a mechanism and position detection means for transmitting the rotation of the electric motor to the adjustment screw are used. The problem is that the structure becomes complicated. Therefore, the technical problem of the present invention is to make it possible to automatically change the set pressure with a simple structure.

0004

[Means for Solving the Problems] The technical means of the present invention taken to solve the above-mentioned technical problems is to provide a pressure-responsive device such as a diaphragm or bellows that has one side subjected to fluid pressure on the secondary side. A magnet is attached to the other surface of the member, and a fixed iron core and an excitation coil are arranged to generate a magnetic force that repels the magnet when energized, and a control means is provided in which the functional relationship between the magnitude of the current applied to the excitation coil and the set pressure is stored in advance. A control means is provided to control energization of the excitation coil.

[0005]

[Operation] The operation of the above technical means is as follows. Since the control means stores in advance the functional relationship between the current value to the excitation coil and the set pressure, when an arbitrary pressure value to be set is input, the current value is calculated based on the functional relationship. When the excitation coil is energized based on this current value, magnetic force is generated on the surface of the fixed core facing the magnet, and as the current increases, the repulsive force increases. This repulsive force sets the force that is applied to one side of the diaphragm. On the other hand, the fluid pressure on the secondary side acts on the other side of the diaphragm, and if the two forces are unbalanced, the diaphragm is displaced and the main valve is actuated either directly or indirectly through the pilot valve. Operate to adjust the amount of fluid passing and set the pressure on the secondary side to the set pressure. In this way, the repulsive force between the fixed core and the magnet is applied to the diaphragm, and this repulsive force is adjusted by the value of the current flowing to the excitation coil, so it is possible to set the force applied to one side of the diaphragm with a simple structure. can.

[0006]

[Example] An example showing a specific example of the above technical means will be described (see FIG. 1). Inlet 1 and outlet 2 in the valve casing,
A main valve port 3 is formed, and the main valve port 3 is opened and closed by a main valve element 5 that is biased in the valve closing direction by a main valve spring 4. A piston 9 is slidably disposed within a cylinder 10, and a lower piston rod of the piston 9 abuts an upper protrusion of the main valve body 5. The fluid pressure on the outlet 2 side acts on the lower surface of the piston 9, and the fluid pressure on the inlet 1 side is introduced into the upper surface through primary pressure passages 11 and 12 under control of a pilot valve 13. Pilot valve 1
3 is biased by a spring in the valve closing direction, contacts the lower surface of the diaphragm 14 via the valve stem, and receives an operating force in the valve opening direction due to its displacement.

A magnet 15 is attached to the upper surface of the diaphragm 14. A fixed iron core 17 is installed in the case 16 facing the magnet 15.
is attached, and an excitation coil 18 is placed around it. Control of energization to the excitation coil 18 is performed by a control means (not shown). The control means stores in advance the functional relationship between the current value to the exciting coil 18 and the set pressure. The lower surface of the diaphragm 14 faces the diaphragm chamber 20 through the secondary detection passage 19 communicating with the outlet 2.

[0008] When an arbitrary pressure value to be set is input,
The control means calculates a current value based on the functional relationship and controls the current value applied to the exciting coil 18. Excitation coil 18
When energization is performed, a magnetic force is generated on the surface of the fixed iron core 17 facing the magnet 15, and as the current increases, the repulsive force increases. A force acting on one surface of the diaphragm 14 is set by this repulsive force. When the diaphragm 14 is displaced downward, the pilot valve 13 is pushed down and opened.
The fluid at the inlet 1 is introduced above the piston 9 through the passages 11 and 12, the main valve body 5 is pushed down by the piston 9, the main valve port 3 is opened, and the fluid at the inlet 1 flows to the outlet 2. When the pressure on the secondary side increases, the pressure in the diaphragm chamber 23 also increases through the secondary detection passage 22, and the diaphragm 14 is displaced upward. As a result, the pilot valve 13 is pushed up and closed, the fluid supplied above the piston 9 is reduced, the main valve body 5 is pushed up by the main valve spring 4, and the main valve port 3 is closed. Repeat the above steps to maintain the pressure on the secondary side at the desired value.

[0009]

As described above, according to the present invention, it is possible to obtain an automatically set pressure reducing valve that has a simple structure and can automatically change the set pressure.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an automatic setting pressure reducing valve according to an embodiment of the present invention.

[Explanation of symbols]

1 Entrance 2 Exit 3 Main valve port 5 Main valve body 14 Diaphragm 15 Magnet 17 Fixed iron core 18 Excitation coil

Claims (1)

[Claims] Claim 1: A fixed iron core and an excitation coil, which have a pressure-responsive member such as a diaphragm or bellows on which fluid pressure is applied on one surface and a magnet attached to the other surface, and generate a magnetic force that repels the magnet when energized. The automatic setting pressure reducing valve is provided with a control means in which the functional relationship between the magnitude of the current to be energized to the excitation coil and the set pressure is stored in advance, and the control means controls the energization to the excitation coil.