JPH03611Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a proportional valve that is installed in a flow channel to control the flow rate of fluid flowing through the flow channel, and in particular has a closing function to control the flow rate of fluid flowing through the flow channel. This invention relates to a proportional valve suitable for flow rate control.

Problems to be solved by conventional techniques and ideas A proportional valve that controls the flow rate of fluid in a fluid flow path is
Generally, the valve body that adjusts the opening degree of the valve port provided between the inlet and outlet of the body is biased in the valve closing direction by the elasticity of a compression coil spring for return, and the The actuator has a structure in which an actuator is attached to the body to press the valve body in the valve opening direction against the elasticity of the compression coil spring, and the degree of opening of the valve port by the valve body is adjusted by controlling the actuator. Proportional valves like this are originally intended to control the flow rate, but if a compression coil spring with a large elastic expansion force is used to bias the valve body in the valve opening direction, it can be used to control the actuator. When the current is cut off, the valve body can have the function of closing the valve port by the elasticity of the compression coil spring and cutting off the flow of fluid, similar to an electromagnetic on-off valve. However, if a compression coil spring with a large elastic expansion force is used for such a return spring, an actuator with a correspondingly large output must be used, which not only increases the size of the device, but also requires a high-output actuator. Since a large control current is required and a large-capacity control device must be used, conventionally, when it is required to cut off the flow of fluid in a fluid flow path, an electromagnetic on-off valve is placed in series in addition to this proportional valve. However, especially when the fluid used is a dangerous substance such as gas, it is necessary to install two electromagnetic on-off valves in series to increase the reliability of shutoff, which requires long piping for the fluid flow path. Moreover, there is a drawback that piping work is time-consuming, and even when the valves are combined into a unit to facilitate piping work, there are limits to miniaturization.

Means for Solving the Problems As a means for solving the above problems, the present invention has a built-in compression spring for closing that urges the valve body upward, and the plunger elastically contracts the compression spring when energized. The solenoid, which moves downward and releases the energization, is attached to the body by fitting the tip of the guide tube of the plunger into a through hole formed in the lower surface of the body corresponding to the lower part of the valve body, and attaching the solenoid to the body. A cover body is provided above the opening to cover the upper part of the gap between the inner periphery of the opening at the upper end and the outer periphery of the plunger.

Function and effect of the invention The proportional valve with a closing function of the invention has the above configuration,
When the solenoid is energized, the biasing force of the closing compression spring on the valve body in the valve opening direction is released, and the actuator operates only against the elasticity of the spring for returning the valve body. However, when the solenoid is de-energized, the valve body moves in the valve-closing direction due to the elasticity of the closing compression spring, and the valve opening is closed. Since the actuator's actuating body operates only against the elasticity of the valve body's return spring, there is no need to use a high-output actuator, and the existing actuator and its control device can be used as is. In addition, since it has a closing function that closes the valve port by cutting off the energization of the solenoid, there is no need to install a separate on-off valve to prevent fluid flow in case of a power outage, and it also improves safety. Even if on-off valves are installed in series, it is sufficient to install only one. Therefore, the piping for the fluid flow path is short and the piping work is easy. Furthermore, this on-off valve can be combined with the proportional valve into one. When forming a unit into a unit, only one on-off valve is required, which simplifies the fluid flow path, reduces pressure loss in the flow path, and makes the entire unit smaller. Since a cover is provided to cover the upper part of the gap between the inner periphery of the opening and the outer periphery of the plunger, foreign matter such as chips generated during piping and accumulated in the gas flow path will flow through the valve port from above. It is carried by the gas flow and falls into the opening at the upper end of the plunger guide, preventing it from entering the gap between the guide tube and the plunger guide and causing malfunction of the plunger, thereby improving reliability. .

Embodiment Hereinafter, an embodiment in which the present invention is applied to a gas control valve will be described based on the accompanying drawings.

In FIG. 1, reference numeral 1 denotes the body of a proportional valve 4 according to the present invention, in which a vertical valve port 2 is formed on the left side between an outlet port and an inlet port (not shown) formed on the front surface on both the left and right sides, respectively. A valve seat 3 made of synthetic rubber is fitted to the mouth edge of the valve seat 3, and a bowl-shaped valve body 5 that moves up and down to move toward and away from the valve seat 3 is connected to a spring receiving surface formed on its lower surface. The elastic expansion force of the return compression coil spring 10 with a small spring constant is installed between the closing plate 8 that closes the lower surface of the body, and the upper surface of the valve body 5 is biased upward in the valve closing direction. A valve rod 11 is protruded to press downward in the valve opening direction, and an actuator 15 for driving the valve rod 11 is mounted on the upper surface of the opening 12 of the body 1 above the valve rod 11 to tighten the screw 14. The actuator 15 includes two ring-shaped permanent magnets 18, which are stacked concentrically and fixed on the upper surface of an annular mount 17 fixed to the body 1.
A sleeve 20 is fitted into the center hole of the permanent magnet 18, and inside the sleeve 20 is a cylindrical center pole 21 made of a magnetic material.A collar 22 integrally formed on the outer periphery of the upper end of the center pole 21 is joined to the upper surface of the permanent magnet 18. The center pole 21 is supported concentrically with a space between it and the inner periphery of the sleeve 20, and a coil bobbin 23 having a bottomed cylindrical shape with a coil 19 wound around the outer surface slides around the center pole 21. Fitted with freedom of movement,
A fitting hole 27 of an engaging portion 24 protruding from the center of the lower surface of the bottom plate is fitted into the upper end of an engaging shaft 16 protruding from the upper end of the valve rod 11. A diaphragm 13 sandwiched between the mount 17 of the actuator 15 and the body 1 seals the area between the opening 12 of the body 1 and the periphery of the opening 12 of the body 1 . Below the valve body 5, a solenoid 7 is attached to the lower surface of the closing plate 8 that closes off the lower surface of the body 1, and this solenoid 7 is fitted into an external core 28 fixed to the lower surface of the closing plate 8. A guide tube 30 is fitted into the center hole of the coil 29 with its upper end protruding from the upper surface of the outer core 28, and its upper end is inserted into a through hole formed in the center of the conical protrusion of the closing plate 8. 31 and is fitted into an annular space with a triangular cross section formed between the lower surface of the protrusion and the upper surface of the external core 28.
is crushed between them, thereby sealing the space between the guide tube 30 and the through hole 31, and a core 33 is attached to the reduced diameter step inside the lower end of the guide tube 30. The guide tube 3 is airtightly fitted by the O-ring 34.
The plunger 35, which is slidably inserted into the core 33, is urged upward by the elasticity of the closing compression coil spring 36 with a large spring constant, which is installed between the plunger 35 and the core 33. The upper end of the mating shaft 37 is in contact with the center of a recess formed on the lower surface of the valve body 5, so that the valve body 5 is in contact with the compression coil spring 36.
is pressed against the valve seat 3 by the elastic force of the valve body 5, and the valve port 2 is closed by the valve body 5.

And the guide tube 30 of the plunger 35
A cover 45a having a bottomed cylindrical shape is attached between the upper end and the upper end of the engagement shaft 37 of the plunger 35, and the cover 45a is molded from synthetic rubber. A tightening ring 46 is formed around the opening of the plunger guide 35 , and a tightening ring 47 is formed around a central hole transparently provided in the center of the upper surface.
Placed from above, the lower end tightening ring 46 is fitted around the flange portion 30a formed by bending the upper end portion protruding from the through hole 31 of the guide tube 30 outward, and the upper end tightening ring 47 is placed from above. The engaging shaft 37
It is attached by tightly fitting around the lower side of a flange 48 formed on the upper end, and this cover 45a allows the inner periphery of the opening at the upper end of the guide tube 30 and the plunger 35 to be connected. The upper part of the gap between the body 1 and the outer periphery is cut off from the fluid flow path within the body 1.

On the other hand, on the right side of the body 1 is an electromagnetic on-off valve 38.
This electromagnetic on-off valve 38 has a valve body 40 that opens and closes a valve port 39 on the right side in the figure, which is formed between the valve port 2 of the proportional valve 4 and the inlet. It is urged in the valve closing direction and is connected to a plunger 43 of a solenoid 42 attached to the top surface of the body 1. By energizing the solenoid 42, the valve body 40 is caused to respond to the elasticity of the compression coil spring 41. The solenoid 42 of the electromagnetic on-off valve 38, the solenoid 7 of the proportional valve 4, and the actuator 15 are connected to a control device, respectively. Depending on the device, the solenoids 7 and 42 are energized and energized simultaneously, and the coil 19 of the actuator 15 is supplied with a control current.

Next, the operation of this embodiment will be explained.

When the control device energizes the solenoid 7 of the proportional valve 4 and the solenoid 42 of the electromagnetic on-off valve 38, the valve port 39 of the electromagnetic on-off valve 38 is opened, and the plunger 35 of the solenoid 7 of the proportional valve 4 closes the core 3.
3 and moves downward against the elasticity of the closing compression coil spring 36, the upper end of the plunger 35 engages with the deformation of the cover 45a as shown by the chain line in FIG. The tip of the shaft 37 separates from the lower surface of the valve body 5, thereby releasing the biasing force of the closing compression coil spring 36 on the valve body 5 in the valve closing direction. When a control current is applied to the coil 19 by the control device, the coil 19 generates a magnetic field, and the interaction between this magnetic field and the magnetic fields of the permanent magnets 18 causes the coil bobbin 23 around which the coil 19 is wound to move toward the valve body 5. The engagement shaft of the valve rod 11 The upper end of the coil bobbin 23 is pushed down by the engaging portion 24 at the lower end of the coil bobbin 23 in accordance with the control current, whereby the degree of opening of the valve port 2 by the valve body 5 is adjusted in proportion to the control current, and the inflow port of the body 1 is from the proportional valve 4.
The flow rate of gas flowing out from the outlet is controlled through the valve port 2 of the electromagnetic on-off valve 38.
When the solenoid 42 of the proportional valve 4, the solenoid 7 of the proportional valve 4, and the actuator 15 are de-energized,
The valve body 40 of the electromagnetic on-off valve 38 is a compression coil spring 41
The elasticity of the valve moves back and closes the valve port 39, and the plunger 35 of the solenoid 7 of the proportional valve 4
moves back due to the elastic expansion force of the closing compression coil spring 36, and as shown by the solid line in FIG. By pushing up, the valve body 5 is pressed against the valve seat 3 of the valve port 2 and the valve port 2 is closed, and both the valve port 39 of the electromagnetic on-off valve 38 and the valve port 2 of the proportional valve 4 are closed. This ensures that gas is prevented from flowing out from the outlet.

In addition, in this embodiment, the guide tube 3
Since the gap between the inner periphery of the opening at the upper end of body 1 and the outer periphery of plunger 35 is isolated from the gas flow path, when connecting gas pipes to the inlet and outlet of body 1, the gas Even if foreign matter such as chips generated when threading a pipe connection gets into the flow path, the gas flow flowing through the valve port 2 from above will remove the foreign matter from the plunger 35 and the guide tube. This prevents the plunger 35 from falling above the gap between the plunger 35 and the plunger 30, and prevents foreign matter from entering through the gap, thereby reliably preventing the plunger 35 from malfunctioning.

FIG. 2 shows a cover body 45b as a modification,
This cover body 45b is the same as the cover body 45a but has a bellows-shaped side circumferential portion.

Furthermore, although both the covers 45a and 45b are designed to completely block the fitting gap between the plunger 35 and the guide tube 30 from the gas flow path, foreign matter in the flow path may cause the plunger 35 and the guide tube 30 to The reason why the plunger 35 may fall above the fitting gap with the actuator 15 is as shown by the chain line in FIG.
Since this is only when gas flows through the valve port 2 by opening the valve port 2, as shown by the chain line in FIG.
A dish-shaped cover 45c that covers the upper surface of the conical projection 31a is attached to the cover 45a, 4.
It may be attached to the upper end of the plunger 35 instead of 5b.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of one embodiment of the present invention, and FIGS. 2 and 3 are cross-sectional views of a portion of the device with a modified cover mounted thereon. 1...Body, 2...Valve port, 4...Proportional valve, 5
... Valve body, 10 ... Compression coil spring for return, 11
... Valve rod, 15 ... Actuator, 23 ... Coil bobbin (operating body), 30 ... Guide tube,
31...Through hole, 35...Plunger, 45a, 4
5b, 45c...Covering body.

Claims (1)

[Scope of utility model registration request] The valve body that adjusts the opening degree of the vertical valve port provided between the inlet and outlet of the body is urged upward by the elasticity of the return spring, and the valve body is pushed downward to open the valve. An actuator is connected above the valve rod of the body to connect a valve rod to be driven to the valve element, and the actuator presses the valve rod in proportion to the control current against the elasticity of the return spring. The proportional valve is configured to adjust the degree of opening of the valve port by the valve body by mounting the actuator and controlling the actuator. A solenoid that moves downward while elastically compressing a compression spring to release the bias is fitted with the tip of the guide tube of the plunger into a through hole provided in the lower surface of the body corresponding to the lower part of the valve body. A closing function characterized in that a cover is provided above the opening and is attached to the body and covers an upper part of the gap between the inner periphery of the opening at the upper end of the guide tube and the outer periphery of the plunger. With proportional valve.