JPH0249427Y2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> This invention relates to a gas cutoff valve, and particularly relates to an improvement in the airtight structure between a housing housing a gas cutoff solenoid and a valve housing.

<<Prior Art>> As shown in FIG. 4, conventional solenoid type gas cutoff valves include a solenoid housing 3 that accommodates a solenoid 2 attached to a valve housing 1, and a plunger 4 that protrudes from the solenoid 2 within the housing 3. A valve body 5 is provided at the tip of the valve body 5, and the valve body 5 is opposed to a nozzle 6 that constitutes a valve seat.

In this structure, the detection means for driving the solenoid 2 is configured as follows.

That is, a side chamber 7 is integrally formed on the gas downstream side of the valve housing 1, and the side chamber 7 has a communication hole 7a.
It communicates with the gas downstream through. The inside of the side chamber 7 is airtightly partitioned into a gas chamber G and an atmospheric pressure chamber A by a pressure sensitive diaphragm 8, and a switch 9 interlocked with the pressure sensitive diaphragm 8 detects the reduced pressure state of the gas. Then, the solenoid 2 is activated, and the valve body 5 is pressed against the nozzle 6 to cut off the gas flow path.

[Problems to be solved by the invention] However, with this configuration, it is necessary to ensure sealing between the valve housing and the solenoid housing and the sliding contact surface of the plunger, which makes the sealing structure complicated. Resistance increases in the sliding portions, which necessitates increasing driving power.

Furthermore, since this structure integrates the side chamber into the valve housing, a complicated mold structure must be used for mold cutting, resulting in an increase in cost.

This invention was made in view of the above problems, and aims to solve the problem of mold cutting by simplifying the structure of the valve housing with a simple seal.

<<Means for Solving the Problems>> In order to achieve the above object, this invention airtightly connects the valve housing and the solenoid housing via a pressure-sensitive diaphragm, and the diaphragm is formed into a double ring shape, and the periphery of the solenoid housing is is held between the respective housings, and the intermediate position is held by a fixed part, and further, a valve body provided at the tip of the plunger of the solenoid housed in the solenoid housing is integrated into the center of the pressure-sensitive diaphragm,
The pressure-sensitive diaphragm is characterized in that the periphery of the central portion thereof is expanded and contracted in conjunction with the operation of the plunger, and the periphery of the diaphragm is linked to a switch for operating a solenoid.

<<Operation>> The valve housing and solenoid housing are sealed by a single diaphragm, which simplifies the sealing structure.

Since there is no need to provide a side chamber, the structure of the valve housing itself becomes simple and mold cutting becomes easy.

<<Example>> Hereinafter, an example of this invention will be described in detail using the drawings.

FIG. 1 is a sectional view of the gas cutoff valve according to this invention.

In the figure, reference numeral 10 denotes a valve housing, 12 a solenoid housing flanged to the upper opening of the valve housing 10, and 14 both housings 1.
The periphery is fixed between 0 and 12, and a gas chamber G is connected between them.
This is a pressure-sensitive diaphragm that airtightly partitions the chamber and the atmospheric pressure chamber A side.

The valve housing 10 has an angled shape,
Gas is introduced through an inlet port 16 formed at the bottom, and gas is discharged through an outlet port 18 formed at one side of the top. A nozzle 20 facing toward the upper opening is formed in this flow path. Therefore, the lower side of the nozzle 20 is the upstream side of the gas, and the upper side is the downstream side of the gas.

A solenoid 22 is disposed inside the solenoid housing 12, and a valve drive shaft 24 is integrated with the plunger thereof.

A flange 26 is integrated into the lower part of the valve drive shaft 24.

The flange 26 is integrally fixed to the center of the diaphragm 14 and faces the upper part of the nozzle 20 so as to be able to move toward and away from it.

The diaphragm 14 is made of an elastic material such as rubber, and as shown in FIG. A bellows 32 having a shape of 32 mm is integrated, and a thick-walled valve body 34 which is connected to the flange 26 is integrally molded at the center of the bellows 32.

Further, an annular seal packing part 36 is integrally formed on the outermost periphery of the diaphragm part 28, and by sandwiching this part between the two housings 10 and 12, the space between them is airtightly sealed.

The cylindrical portion 30 is supported by a fixing cylindrical portion 38 on the lower surface of the solenoid casing 12 via a fixing band 38a, thereby providing independence of movement between the pressure sensitive diaphragm portion 28 and the bellows 32. .

A compression coil spring 37 is in elastic contact between the inner circumferential upper end of the fixing cylinder part 38 and the valve body 34, and the compression coil spring 37 is in elastic contact with the valve body 34 against the attraction force of the solenoid 22.
4 is biased toward the lower side.

By fixing the cylindrical portion 30, the pressure-sensitive diaphragm portion 28 and the bellows 32 can move completely independently.

That is, the bellows 32 expands and contracts only by following the movement of the valve body 34, and the pressure sensitive diaphragm portion 28
perform expansion and contraction operations in response to pressure fluctuations within the gas chamber.

A diaphragm receiving plate 40 is disposed above the pressure-sensitive diaphragm portion 28, and a compression coil spring 42 interposed between the diaphragm receiving plate 40 and the solenoid housing 12 counteracts the pressures on the atmospheric pressure chamber A side and the gas chamber G side. ing.

Furthermore, a micro switch 44 is installed on one side of the upper part of the diaphragm receiving plate 40 to face it.

This switch 44 is a normally closed type switch, in which the gas pressure is equal to the atmospheric pressure, and the diaphragm portion 2
Turn on the contact when 8 is in the raised position. and,
The gas pressure is lower than atmospheric pressure, that is, a gas leak has occurred on the gas downstream side, and the pressure sensitive diaphragm section 28
Turns OFF when decreases.

The solenoid 22 is normally connected to the valve drive shaft 2.
4 is held in the raised position, thereby holding the valve body 34 in the raised position and opening the nozzle.

On the other hand, when the switch 44 is turned off by the above-described action or when another operating switch is inputted, the solenoid 22 releases the force holding the plunger and the spring 3
7, the valve drive shaft 24 protrudes.
Thereby, the valve body 34 closes the nozzle 20.

In either case, when the switch 44 is turned off, the valve body 34 is held in a closed state, and if the gas pressure on the downstream side is reduced for some reason, the gas cutoff operation continues.

Next, FIG. 3 shows another embodiment of this invention.

The pressure-sensitive diaphragm 50 in the figure includes a pressure-sensitive diaphragm portion 52 with a seal ring 51 integrated on the outermost periphery, a flexible cylindrical portion 54 integrally hung in the center of the pressure-sensitive diaphragm portion 52, and a cylindrical portion. It consists of a thick-walled valve body 56 that is integrally molded on the lower surface of the portion 54, and the center of the valve body 56 is connected to the flange 26 that is integrated with the valve drive shaft 24.

A stopper portion 58 is disposed on the inner circumferential portion of the cylindrical portion 54 to cut off joint movement between the pressure-sensitive diaphragm portion 52 and the cylindrical portion 54.

In this embodiment, the cylinder part 54 expands and contracts in accordance with the movement of the pressure-sensitive diaphragm part 52, but since the cylinder part 54 is flexible, this expansion and contraction movement does not affect the operation of the valve body 56. Similarly to the embodiments described above, the valve body 56 and the pressure-sensitive diaphragm portion 52 perform independent expansion and contraction operations.

<<Effects of the invention>> As explained in detail in each of the embodiments above, in this invention, the valve housing and the solenoid housing are sealed by a single diaphragm.
Seal structure becomes simpler. In addition, this invention eliminates the need for the side chambers found in the prior art, and the structure of the valve housing itself is simple, simplifying the mold structure and reducing the number of parts, resulting in lower manufacturing costs.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a gas cutoff valve according to this invention, Fig. 2 is a partially sectional perspective view of a diaphragm, Fig. 3 is an enlarged sectional view showing a diaphragm portion according to another embodiment of this invention, and Fig. 4. is a sectional view of a conventional gas cutoff valve. DESCRIPTION OF SYMBOLS 10... Valve housing, 12... Solenoid housing, 14... Pressure sensitive diaphragm, G... Gas chamber, A... Atmospheric pressure chamber, 20... Nozzle, 22...
...Solenoid, 24...Valve drive shaft, 28, 52...
. . . Pressure-sensitive diaphragm portion, 30, 54 .

Claims (1)

[Scope of utility model registration request] The valve housing and the solenoid housing are airtightly coupled via a pressure-sensitive diaphragm, and the diaphragm is formed into a double ring shape, and the periphery is sandwiched between the housings, and the intermediate position is held at a fixed part. A valve body provided at the tip of a plunger of a solenoid housed in a solenoid housing is integrated into the center of the pressure-sensitive diaphragm, and the periphery of the center of the pressure-sensitive diaphragm expands and contracts in conjunction with the operation of the plunger, and the diaphragm A gas cutoff valve characterized in that a peripheral portion of the valve is connected to a switch for operating a solenoid.