JPS6256678A - Gas shut off valve - Google Patents

Abstract

PURPOSE:To make it possible to form a magnetic route in which the magnetic loss is small so as to get a gas shut off valve superior in its magnetic efficiency, by setting a packing for providing airtightness between the inside of a yoke and the open air. CONSTITUTION:An air tight packing 15 which provides airtightness between the inside of a yoke 1 and the open air, is set on the back surface of the flange 1a of the yoke 1. A washer 16 which is made of a magnetic body, is set on the surface of the flange 1a, and then, the packing 15 and the washer 16 are fixed to the flange 1a airtightly, by a seal flange 6. The yoke 1 is formed to be cylindrical. Accordingly, a conventional metal guide pipe and on O-ring, made of nonmagnetic bodies which bring the loss of magnetic characteristics, can be deleted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a gas cutoff valve used as a safety device in a piping system (1) for supplying gaseous fuel.

Conventional technology In recent years, city gas supply companies and the LP gas supply industry have installed gas meters that measure gas usage as a means of ensuring safety and security when using gas. We are considering installing a gas cutoff valve to close the passage.

Hereinafter, examples of the conventional JJ's cutoff valves mentioned above will be described with reference to the drawings.

FIG. 2 shows a longitudinal sectional view of a conventional gas cutoff valve. In FIG. 2, a core piece 2 is fixed to the bottom of a U-shaped magnetic yoke 1, a guide pipe 3 made of non-magnetic metal is fitted outside the core piece, and an electromagnetic coil 4 is fitted around the outer periphery of the guide pipe 3. A permanent magnet 5 is attached to the upper end of the electromagnetic coil 4 so as to face each other. A cut-and-raised portion 1a is provided on both sides of the yoke 1, and a seal flange 6 is fastened and fixed to the cut-and-raised portion with screws. On the other hand, the movable part of the gas cutoff valve is )-,・jar 7
Insert the valve rubber 8 into the tip of the device 7.1. It has a structure in which the plunger 7 is completely inserted into the guide pipe 3. In addition, an O-ring 9 is used inside the gas valve 3, and an O-ring 10 is used on the outside to airtightly isolate the gas passage side where the valve rubber 8 is located and the atmosphere side where the coil 4 and yoke 1 are located. Techiru.

The operation of the gas cutoff valve configured as above will be explained below.

First, when the plunger 7 is pushed in with the setting rod 11, the attraction force of the permanent magnet 5, which is greater than the reaction force of the spring 12, is generated on the attraction surface between the plunger 7 and the core piece 2, and the core piece 2 is attracted and held as it is.

In this state, the valve rubber 8 is in the state where the valve seat 13 is opened, that is, the valve is in the open state.

When the valve is closed, when the electromagnetic coil 4 is momentarily energized in a direction that generates magnetic lines of force in the opposite direction to the permanent magnet 5, the attraction force between the core piece 2 and the plunger = c-7 decreases, and the spring 1
2 becomes relatively large, the plunger e-7 separates from the knob piece 2, and the valve rubber 8 closes the valve seat 13.

Problems to be Solved by the Invention However, in the above configuration, since the guide vibe 3 made of non-magnetic metal is used between the plunger 7 and the permanent magnet 5 and between the plunger 7 and the electromagnetic coil 40, the plunger This causes a loss of magnetic flux flowing through the magnetic flux. th core bi-
Insert the airtight O-IJ ring 9 between the base 2 and the U4 drive 3. Originally, the outer diameter of the core beam 2 and the plunger □e-7 should be the same as the inner diameter of the O-ring. Although a size equal to 1 - is sufficient for magnetic properties, it has the problem that a diameter equal to the outer diameter of the O-ring 9 must be used, which is uneconomical.

In view of the above-mentioned problems, the present invention reduces the loss of magnetic flux flowing on the attracting surface of the plunger and core piece, which has a magnetic operating point.
Lottery magnetic efficiency? The purpose of the present invention is to provide a gas cutoff valve that is improved in size and reduced in size by reducing the diameter of the plunger and core piece.

Problems and Means for Solving the Problems In order to solve the above problems, the gas cutoff valve of the invention is a permanent valve that normally holds a plunger with valve rubber at one end to keep the gas passage open. When something goes wrong with a magnet, a magnetic field in the opposite direction to the permanent magnet's magnetic field is excited to move the plunger.
Remove from the abyss and close the gas passage.2. It has a magnetic coil, a yoke in which the electromagnetic coil, a permanent magnet, and a core piece are housed in a bottomed cylindrical part, and a bulge provided on the outer periphery of the upper end of this yoke to make the inside of the yoke airtight from the outside air. It is something.

Effect of the present invention With the above-described configuration, in the bottomed cylindrical portion of the yoke,
Gas leakage is prevented, and since the inside of the yoke and the outside air are airtight with a gasket, even if gas flows into the coke, it will not leak to the outside. Therefore, the conventional non-magnetic metal guide pipe and O-ring between the permanent magnet and the plunger and between the coil and the plunger are unnecessary.

EXAMPLE Hereinafter, a gas cutoff valve according to an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a longitudinal sectional view of a gas cutoff valve in one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a magnetic metal yoke with a cylindrical narrowed tube part and a flange 1a, and a permanent magnet 5 is fixed to the center bottom of the yoke 1.
The upper surface of the i-ri 1 and the opposite r/↑ side (7 is the core piece 2
(Z).

14 is permanent r1 stone 5 h(j ” 7 ?'l”-su 2
It is a synthetic resin bobbin that is attached to the cylindrical part of the yoke 1 as a Z VC ('MJL) and is wound with an electromagnetic Z VC (4). The sealing member 6 was applied for 15 minutes, and a magnetic washer τ-16 was applied to the surface of the collar 1a and the collar i4a of the bobbin 14, and then placed on the upper surface of the warashima-16.
The entire circumference of the collar 1a is caulked by caulking a part 6a of the collar 1a.゛The lead wire 17 of the electric wire 4 is still insulated from the yoke 1 by a bar/menox seal or the like.

On the other hand, in the r'iJ moving part, the valve rubber 8 is fitted into the tip of the pusher 7, the plunger 7 is inserted into the bobbin 14, and the spring 12 is installed between the seal flange 6 and the inner rubber 8. It has a similar structure.

The operation of the gas cutoff piece constructed as described above will be explained below in 7-1 with reference to FIG.

Figure 1 shows valve rubber a of normal temple b and ζ73 shield 15 e,
1; [; - shows a longitudinal cross-sectional view when the gas passage is in an open state. First, when the plunger τ-7 is pushed in with the setting rod 11, the plunger 7 moves and comes into contact with the core piece 2, and an adsorption force greater than the reaction force of the spring 12 is applied to the yoke 1, the washer 16, and the plunger τ-7.
The magnetic flux of the permanent magnet 5 flowing through the plunger 7 and the core piece 2 is generated on the attraction surface between the plunger 7 and the core piece 2, and the plunger 7 and the core piece 2 are attracted and held as they are. In this state, the valve rubber 8 is attached to the valve seat 13.
The valve moves away from the valve, and the valve becomes open, allowing gas to flow in the direction of the arrow. In this case, the gas passes through the gap between the bobbin 14 and the plunger 7, the core piece 2, and the permanent magnet 5, and the gap between the bobbin 14 and the washer e-16, and passes through the yoke 1.
However, since the airtight gasket 15 is attached, the gas does not leak to the outside.

In the event of an abnormality, when the electromagnetic coil 4 is instantaneously energized so as to generate a magnetic field in the opposite direction to that of the permanent magnet 5, the attraction force between the core piece 2 and the plunger r7 decreases, and the reaction force of the spring 12 becomes relatively large. Then, the plunger 7 separates from the core piece 2, and the valve rubber 8 closes the valve seat 13 to cut off the flow of gas. Note that although the bobbin 14 is located between the washer 16 and the plunger 7, this is not always necessary.

As described above, according to this embodiment, the airtight gasket 15 that makes the inside of the yoke 1 airtight from the outside air is provided on the back surface of the collar 1a of the yoke 1, and the magnetic washer e is provided on the surface of the collar 1a.
-16 is provided, and the seal flange 6 is provided with a seal 15.
, the washer 16'1fiia, and since the yoke 1 is made into a cylindrical portion, it is possible to eliminate the non-magnetic metal guide pipe and O-ring which cause loss of magnetic properties in the conventional example.

Effects of the Invention As described above, the present invention provides a gas-tight seal between the inside of the yoke and the outside air, thereby forming a magnetic path with less magnetic loss, thereby providing a gas cutoff valve with good magnetic efficiency. Also, since the magnetic path can be formed using a plunger and core piece with a smaller diameter than conventional ones, it is possible to create a small gas cutoff valve.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a gas cutoff valve according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of a conventional gas cutoff valve. 1... Yoke, 2... Core piece, 4...
... Coil, 5 ... Permanent magnet, 6 ...
... Seal flange, 7... Plungmer,
8...Valve rubber, 15...Airtight packing, 16...Washer.

Claims (1)

[Claims] Under normal conditions, a permanent magnet attracts the plunger with a valve rubber at one end to open the gas passage, and when an abnormality occurs, a magnetic field in the opposite direction to the magnetic field of the permanent magnet is excited to cause the plunger to separate from the core piece and open the gas passage. The yoke is equipped with an electromagnetic coil that is brought into a closed state, a yoke in which the electromagnetic coil, a permanent magnet, and a core piece are housed in a bottomed cylindrical part, and a packing provided on the outer periphery of the upper end of the yoke to make the inside of the yoke airtight between the outside air and the outside air. Gas shutoff valve.