JPH0443654Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention is a proportional valve that is interposed in a fluid flow path and controls the flow rate of fluid flowing through the flow path, and a proportional valve that has the function of closing the flow path. Regarding improvement of proportional valve with function.

Problems to be Solved by Prior Art and Ideas A proportional valve is generally a valve that adjusts the opening degree of a valve port provided between an inlet chamber and an outlet chamber that communicate with an inlet and an outlet of a body, respectively. A proportional solenoid that urges the valve body in the valve closing direction by the elastic expansion force of the return spring, and the plunger presses the valve body against the elastic expansion force of the return spring in proportion to the control current flowing to the coil. is attached to the body, and its operation adjusts the degree of opening of the valve port by the valve body.In such a proportional valve, an elastic expansion force is applied to the return spring that biases the valve body in the valve closing direction. By using a large one, when the control current of the proportional solenoid is cut off, the valve body can have the function of closing the valve port with the elastic expansion force of the return spring and cutting off the flow of fluid. When applied to the control of fluids such as fuel gas that require complete closure, it is possible to reduce or eliminate the number of on-off valves connected in series. If the elastic expansion force of the spring is increased, a large force is required to open the valve, so a proportional solenoid with a large output must be used, resulting in an increase in size and power consumption. Therefore, the applicant of the present application developed a closing compression coil spring that biases the valve body in the valve closing direction with a force greater than that of the return spring, as a proportional valve with a closing function that allows the conventional small-output proportional solenoid to be used as is. When the plunger is energized, the compression coil spring is elastically compressed to release the above-mentioned bias.When the fluid is to flow, the plunger is energized and the compression coil spring is compressed. Release the bias in the valve closing direction by the coil spring, operate the valve body against only the elasticity of the return spring using the proportional solenoid to control the flow rate, and cut off the energization to the closing release solenoid. proposed a system in which the valve body is moved back and forth using the biasing force of a closing compression coil spring to close the valve port.

By the way, as mentioned above, if the fluid used is a dangerous substance such as fuel gas, in addition to the above-mentioned proportional valve with a closing function, another electromagnetic on-off valve should be connected in series with the flow path on the inlet side. However, if both the proportional valve and the on-off valve are sealed, gas will be trapped in the flow path between them, and if the ambient temperature drops, the gas will leak out. The volume of the proportional valve contracts, creating a negative pressure in the flow path, and as a result, the diaphragm stretched between the proportional solenoid and the body of the proportional valve is forcibly pulled toward the inflow chamber, and the part where it is attached to the valve rod is Cracks appear, or
There was still room for improvement, as the valve element of the proportional valve was pressed strongly against the valve seat to close the valve, requiring a large amount of force to open the valve, making it necessary to increase the output of the proportional solenoid.

Means for Solving the Problems The proportional valve with a closing function of the present invention is equipped with a closing compression coil spring in the outflow chamber that biases the valve body in the valve closing direction with a force greater than that of the return compression coil spring. , the body is equipped with a closing release solenoid that elastically contracts the closing compression coil spring when the plunger is attracted by energizing the coil, and a backing plate with dimensions such that the effective pressure-receiving area of the diaphragm is larger than the pressure-receiving area of the valve body. It has a structure in which the two are superimposed.

Functions and Effects of the Invention The present invention has the above-mentioned configuration, and includes a closing compression coil spring that biases the valve body in the valve closing direction with a force greater than that of the return compression coil spring in the outflow chamber, and energizing the coil. Since the body is equipped with a closing release solenoid that elastically compresses the closing compression coil spring when the plunger is attracted by the plunger, when fluid is to flow, the closing release solenoid is energized and the closing compression coil spring is activated. By releasing the bias in the valve closing direction and controlling the flow rate by operating the valve body against only the elasticity of the return spring using the proportional solenoid, the valve is closed by cutting off the power to the closing release solenoid. The biasing force of the compression coil spring presses the valve body against the valve port and closes it reliably, and since the effective pressure receiving area of the diaphragm is made larger than the pressure receiving area of the valve body, the inflow chamber becomes under negative pressure. When the diaphragm is attracted to the inflow chamber, the force that pushes the valve body away from the valve seat is greater than the force that presses the valve body against the valve seat due to the pressure difference between the inflow chamber and the outflow chamber. becomes larger, and therefore, when the inflow chamber becomes negative pressure, the valve body is biased in the valve closing direction, and the valve can be opened even if the valve opening force by the proportional solenoid is small. Since a relatively large patch plate is superimposed on the surface of the diaphragm on the inflow chamber side, when the inflow chamber becomes negative pressure, only the peripheral edge of the diaphragm is sucked into the inflow chamber, and the entire diaphragm is This has the effect of preventing damage caused by being sucked in and causing large deformation.

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

In the figure, 1 is a body, and an inlet 2 is formed on the lower surface of the left side of the figure, and an outlet 3 is formed on the front of the right side. A valve port 5 of the proportional valve 4 is formed, and an inflow chamber 6 is formed on the inflow port 2 side, and an outflow chamber 7 is formed on the outflow port 3 side. A bowl-shaped valve body 10 that approaches and separates from a valve seat 8 formed on the edge is closed by the elastic expansion force of a return compression coil spring 12 with a small spring constant installed between it and the bottom plate 11 of the outflow chamber 7. A valve rod 14 is protruded from the upper surface of the valve body 10 and protrudes from the open hole 15 of the inflow chamber 6 formed on the upper surface of the body 1 corresponding to the valve port 5. When control power is applied to a coil 20 wound around a plunger 19 fixed at the center of the stretched diaphragm 16 and engaged with the upper end of the valve rod 14 of a proportional solenoid 18 attached to the body 1, the coil 20 Due to the interaction between the magnetic field formed by the plunger 1 and the magnetic field formed by the permanent magnets 21 and 21 attached around the plunger 1
9 moves downward along the guide shaft 22 and presses the valve rod 14 to push down the valve body 10 against the elasticity of the return compression coil spring 12, thereby opening the valve port 5 and opening the proportional solenoid 18. The opening degree of the valve port 5 is adjusted in proportion to the current flowing to the coil 20 of the inlet port 2.
The flow rate of gas flowing from the outlet port 3 to the outlet port 3 is controlled.

A compression coil spring 23 for closing and a solenoid 25 for canceling closing are attached to the bottom plate 11 of the outflow chamber 7 of the proportional valve 4.
is the guide tube 27 fitted into the center hole of the coil 26.
A plunger 28 is slidably fitted therein, and a spring receiving plate 2 is attached to the upper end of the plunger 28.
The upper end of the above-mentioned closing compression coil spring 23 is fitted into 9, and its elastic expansion force applies an upward protruding force to the plunger 28.
When the upper end abuts against the lower surface of the valve body 10, the valve body 10
is pressed against the valve seat 8 with a force greater than that of the return compression coil spring 12, thereby closing the valve port 5. On the other hand, the coil 26 of the solenoid 25 is energized to cause the plunger 28 to elastically expand and close the compression coil spring 23. By attracting the core 30 against the force, the pressing force of the plunger 28 against the valve body 10 is released.

In addition, at a position directly above the inlet 2 in the body 1,
A valve port 35 of the electromagnetic on-off valve 34 is formed, and a valve body 36
However, due to the elastic expansion force of the coil spring 38 installed between the spring holder 37 installed in the middle of the inlet 2, the valve port 35
The valve port 35 is closed by being pressed against the valve seat 39 formed on the lower surface of the coil 41 of the solenoid 40.
By applying electricity to attract the plunger 42 toward the core 43, the rod 4 that protrudes from the plunger 42, passes through the core 43, and is connected to the valve body 36.
4 is movable and pushes down the valve body 36, thereby opening the valve port 35.

In this embodiment, the diaphragm 1
6 is sandwiched between the body 1 and the mounting ring 47 of the proportional solenoid 18 and fixed, and the valve rod 14 is inserted into the center hole 48 of the diaphragm 16.
The reduced diameter portion 14a at the tip of the center hole 50 is inserted into the center hole 50.
a, 51a fitted to the reduced diameter portion 14a of the backing plate 5
0 and 51 are superimposed on the upper and lower surfaces of the diaphragm 16, and the two backing plates 50 and 51 are connected by a compression coil spring 55 installed between a ring 54 and a ring 54 that is engaged in a groove 53 formed in the reduced diameter portion 14a. The center part of the diaphragm 16 sandwiched between is the stepped part 1 of the valve rod 14.
4b and is integrally fixed.
The upper and lower backing plates 50, 51 have a bent portion 50 on the periphery.
b, 51b, the lower backing plate 51 has a larger diameter than the upper backing plate 50, and the effective pressure receiving area of the diaphragm 16 on the inflow chamber 6 side is larger than the pressure receiving area of the valve body 10. It's summery. The effective pressure-receiving area of the diaphragm 16 is determined by the diameter of the fixed part on the outer periphery and the diameter of the backing plate. In this embodiment, the diameter of the open hole 15 of the inflow chamber 6 is D ₁ ,
Assuming that the diameter of the lower backing plate 51 is D ₂ , its effective pressure-receiving area Se is determined by the following empirical formula.

On the other hand, the pressure-receiving area Sg of the valve body 10 is Sg=π×(D ₃ /2) ² where the diameter of the valve port 5 is D ₃ , so to make Se>Sg, for example, D ₁ = 4.2 cm, D ₃ =3.42 cm, the diameter D ₂ of the lower backing plate 51 should be larger than 2.57 cm. However, if the gap c between the lower backing plate 51 and the open hole 15 of the inflow chamber 6 is too small, the diaphragm 16 will be pushed into the inflow chamber 16 as shown by the chain line in FIG.
When it is sucked to the side, it digs into the gap c and becomes inoperable, so it is necessary to set the diameter D ₂ of the lower backing plate 51 so that the gap c is larger than twice the thickness of the diaphragm 16. There is.

The present embodiment has the above-described structure, and when the solenoid 25 for releasing the closure of the proportional valve 4 and the solenoid 40 of the electromagnetic on-off valve 34 are energized, the valve port 35 of the electromagnetic on-off valve 34 opens and the closing force of the proportional valve 4 is applied. is released, and now the coil 20 of the proportional solenoid 18
When a control current is applied, the valve port 5 of the proportional valve 4 opens to an opening proportional to the control current, and the flow rate of gas flowing from the inlet 2 to the outlet 3 is controlled.
When the energization to the solenoid 40 of the electromagnetic on-off valve 34 and the solenoid 25 for unclosing the proportional valve 4 is cut off, the respective valve ports 35 and 5 close, and the outflow port 3
The gas in the flow path between the two valve ports 35, 5 is now in a window-sealed state, and in this state, when the ambient temperature drops, its volume will shrink. As a result, the inside of this flow path becomes negative pressure, and the diaphragm 16 is sucked into the inflow chamber 6. A backing plate 51 is superimposed on the center of the lower surface of the diaphragm 16, so that the diaphragm 16 is sucked into the inflow chamber 6. As shown by the chain line in FIG. Since the effective pressure-receiving area Se on the chamber 6 side is larger than the pressure-receiving area Sg of the valve body 10, the negative pressure in the inflow chamber 6 acts on the valve body 10 in the direction of separating it from the valve seat 8 and opening the valve. , the closing release solenoid 25 is energized and the plunger 2
After the valve 8 moves downward, the valve is easily opened by the relatively small driving force of the proportional solenoid 18.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment in which the present invention is applied to a fuel gas control valve. 1...Body, 2...Inflow port, 3...Outflow port,
5... Valve port, 6... Inflow chamber, 7... Outflow chamber, 8...
... Valve seat, 10 ... Valve body, 12 ... Compression coil spring for return, 14 ... Valve rod, 15 ... Open hole, 16
...Diaphragm, 18...Proportional solenoid, 1
9... Plunger, 20... Coil, 23... Compression coil spring for closing, 25... Solenoid for closing release, 26... Coil, 28... Plunger,
51...Packing board.

Claims (1)

[Scope of utility model registration request] An inflow chamber communicating with the inflow port and an outflow chamber communicating with the outflow port are formed in the body, a valve seat is formed on the outflow chamber side of the valve port formed between the two chambers, and the valve seat is moved toward and away from the valve seat. A valve rod protruding from a valve body that opens and closes a valve port is projected from an open hole of the inflow chamber formed in the body corresponding to the valve port, and a center portion of a diaphragm stretched over the open hole is inserted into the valve body. In addition to connecting to the rod,
A return compression coil spring that biases the valve body in the valve closing direction is installed in the outflow chamber, and a proportional solenoid whose plunger projects with a force approximately proportional to the control current flowing to the coil is installed in the body. In a proportional valve in which the plunger corresponds to the tip of the valve rod,
A closing compression coil spring that urges the valve body in the valve closing direction with a force greater than that of the return compression coil spring is installed in the outflow chamber, and when the coil is energized, the plunger is attracted and the closing compression coil spring is installed. A closing release solenoid for elastically compressing a compression coil spring is installed in the body, and a patch plate is provided on a surface of the diaphragm on the inflow chamber side and has a size such that the effective pressure receiving area of the diaphragm is larger than the pressure receiving area of the valve body. A proportional valve with a closing function characterized by overlapping the two.