JPH0330033B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a gas control device provided in a gas passage of a gas combustion device.

Conventional configuration and its problems Conventionally, a gas control device installed in the gas passage of a gas combustion device that proportionally controls the combustion amount consists of a solenoid valve that opens and closes the gas passage according to an electric signal from a controller, and a gas governor and burner nozzle. It consists of a proportional control valve that controls the gas flow rate to. Here, in order to maintain confidentiality and increase reliability, two solenoid valves are usually connected in series. For this reason, two solenoid valves, a gas governor,
Since a gas control valve composed of a proportional control valve is large and expensive, it has been considered to provide a closing function to the proportional control valve and reduce the number of solenoid valves to one. FIG. 1 shows a conventional gas control device using a proportional control valve having a closing function and a gas governor function.
1 is a solenoid valve that opens and closes the gas passage; gas inlet 2;
It is comprised of a valve body 5 that opens and closes the gas outlet 3 and the valve seat 4, a plunger 7 that opens the valve body 5 by energizing a coil 6, and a spring 8 that presses the plunger 7 in the valve closing direction. A proportional control valve 9 is connected to the downstream side of the electromagnetic valve 1, and the proportional control valve 9 has a gas governor section formed from a diaphragm 10, a valve body 11 integrally attached to the diaphragm 10, and an elastic member. Naru valve seat 1
2. A proportional valve coil 14 as a drive unit that is composed of a spring 13 that presses the valve body 11 and the valve seat 12 in the valve closing direction to apply a closing force, and generates a drive force that acts on the gas governor section using an electric signal; It consists of a plunger 15. 16 is a vent hole that communicates the back pressure chamber 17 of the diaphragm 10 with the atmosphere.
19 is an inlet, and 20 is an outlet. Further, a burner buzzle 18 is connected to the outlet 20 side of the proportional control valve 9. With this configuration, fuel gas is supplied to the inlet 2 of the solenoid valve 1.
The electromagnetic valve 1 is opened by a signal from a controller (not shown), and the proportional control valve 9 is also energized to control the burner secondary pressure to a predetermined burner nozzle 18. It is combusted in a burner (not shown). Further, the burner secondary pressure can be continuously and proportionally controlled according to the amount of current supplied to the proportional valve coil 14. here,
When the use of the gas combustion equipment is finished, the solenoid valve 1 and the proportional control valve 9 are closed. Then, the outlet 3 of the solenoid valve 1
A sealed passage 21 that is sealed to the outside is formed between the side and the inlet 19 side of the proportional control valve 9, and a fuel gas such as propane gas is sealed inside the passage 21.

If the gas combustion equipment is not used in this state for several days or more, the diaphragm 10 of the gas governor section is made of rubber material such as nitrile rubber, so the trapped fuel gas such as propane gas will evaporate. A phenomenon occurs in which the liquid permeates and diffuses into the rubber of the diaphragm 10 and is released to the back pressure chamber 17 side of the diaphragm 10. As a result, the inside of the sealed passage 21 sometimes became negative pressure.

Therefore, due to the negative pressure, the electromagnetic valve or the proportional control valve cannot be opened at a predetermined voltage, and it is necessary to apply a large voltage or to increase the valve opening force by increasing the size of the coil itself. In addition, the film part of the diaphragm 10 is inverted due to negative pressure and is held in an unnatural shape, which increases the stress on the film part, which has the disadvantage that the diaphragm 10 may crack due to ozone deterioration. .

FIG. 2 shows another conventional gas control device that uses a solenoid valve, a gas governor, and a proportional control valve with a closing function. The difference from the conventional example is that a gas governor 22 is provided on the inlet side of the proportional control valve 23 since the proportional control valve 1 having a closing function does not have a gas governor function. The gas governor 22 suppresses fluctuations in supply gas pressure and supplies stable gas pressure to the proportional control valve 23. The proportional control valve 23 proportionally controls the amount of gas flowing into the burner nozzle 18 by adjusting the opening degrees of the valve seat 24 and the valve body 25.

In this configuration as well, similarly to the conventional example, a closed passage 26 is formed on the outlet side of the solenoid valve 1 and the inlet side of the proportional control valve 23, and negative pressure is applied to the closed passage through the diaphragm 27 of the gas governor 22. The same drawbacks as the conventional example described above occurred.

Purpose of the invention The present invention solves such conventional problems,
Gas control allows solenoid valves and proportional control valves to be opened at a predetermined voltage without using gas combustion equipment for long periods of time, and prevents the diaphragm membrane from inverting and applying unnatural reaction force. The purpose is to provide equipment.

Structure of the Invention In order to achieve this object, the present invention provides a check valve between a sealed passage formed by the solenoid valve outlet side and the proportional control valve inlet side, and the proportional control valve outlet.

With this configuration, when the inside of the sealed passage becomes negative, it is communicated with the outlet side of the proportional control valve, and has the effect of preventing excessive negative pressure from becoming inside the sealed passage.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. Note that the same members as in FIG. 1 are designated by the same numbers and their explanations will be omitted. A sealed passage section 21 formed by the outlet side of the solenoid valve 1 and the inlet side of the proportional control valve 9
A check valve 27 is provided which communicates the outlet 20 side of the proportional control valve 9 with the outlet 20 side of the proportional control valve 9. The check valve 27 is connected to the communication hole 2
8 is provided on the check valve body 29 in the closing direction from the outlet side of the solenoid valve 1, and a closing force is applied by a spring 30. 31 is a spring receiver.

In the above configuration, the check valve 27 closes the check valve body 29 when there is pressure acting from the outlet side of the electromagnetic valve 1 to the outlet side of the proportional control valve 9. Then, the gas combustion equipment is not used for several days, and the closed passage section 2
Components of the fuel gas such as propane gas that had been confined in the sealed passage 21 are released to the outside through the diaphragm 10 that is sealed with the outside, and the inside of the sealed passage 21 becomes negative pressure. Initially, when the negative pressure exceeds the closing force applied by the spring 30, the check valve body 29 opens and the proportional control valve 9
It communicates with the outlet 21 of. Therefore, the inside of the sealed passage 21 formed by the outlet 3 side of the solenoid valve 1 and the inlet 19 side of the proportional control valve 9 does not become excessively negative pressure, and when the combustion equipment is used again, the solenoid valve or the proportional control valve can be opened at a predetermined voltage.

In addition, the diaphragm will not be inverted, so that no unnatural stress will be applied to the membrane portion of the diaphragm. Although a solenoid valve is used in one embodiment of the present invention, a manual valve,
A shutoff valve such as a water pressure responsive valve is similarly effective.

Next, another embodiment of the check valve structure of the gas control device of the present invention will be described with reference to FIG. The difference in FIG. 5 from the above embodiment is that a leaf spring 32 is used instead of the spring 30 that applies the closing force, a valve body 34 is provided on the movable side 33 of the leaf spring 32, and a communication hole is provided in the valve body 34. 35 is provided, and is configured to press against the valve seat 37. According to this configuration, the pressure receiving area of the check valve body 34 can be increased, and a smaller negative pressure can be applied. The check valve body 34 can be opened. In addition, since the communication hole 35 can be made smaller, in the unlikely event that foreign matter such as dust adheres to the convex portion 36 of the check valve body 34 and the valve seat 37, the shrinkage function of the check valve will be impaired at a certain point. Then open the communication hole 3.
5, even if gas leaks to the outlet side of the proportional control valve 9, it has the effect of suppressing the leak to a minute amount.

Effects of the Invention As described above, the gas control device of the present invention provides the following effects.

When the inside of the sealed passage formed between the solenoid valve and the proportional control valve with a closing function becomes negative pressure, the check valve operates and prevents excessive negative pressure. The valve can be opened with

Furthermore, the membrane portion of the diaphragm is inverted, and no unnatural stress is applied to the membrane portion.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional gas control device, FIG. 2 is a sectional view of another conventional gas control device, and FIG. 3 is a sectional view of a gas control device showing an embodiment of the present invention.
FIG. 4 is an enlarged view of the main parts of one embodiment of the present invention, and FIG. 5 is an enlarged view of the main parts of a check valve used in a gas control device according to another embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Solenoid valve, 9... Proportional control valve, 10... Diaphragm, 21... Sealed passage section, 27... Check valve.

Claims (1)

[Claims] 1. A proportional control valve having a closing function that can open and close a gas passage, a sealed passage provided on the inlet side of the proportional control valve, a diaphragm that seals the sealed passage from the outside, and a diaphragm that seals the sealed passage from the outside. A gas control device comprising a check valve that communicates the outlet side of the proportional control valve with the sealed passage.