JPH01299383A - Gas cutoff valve - Google Patents

Abstract

PURPOSE:To obtain reliability without malfunction due to external impact by providing a collar part in the periphery of a core piece and guiding a permanent magnet by a sheet metal pressing work. CONSTITUTION:At the time of abnormality, when an electromagnetic coil 6 is instantaneously energized so as to generate a magnetic field opposite to a permanent magnet 2, a magnetic force is generated by the electromagnetic coil 6 so as to reduce attraction force between a core piece 3 and a plunger 9. A magnetic flux in this case passes the plunger 9, the core piece 3, the collar part 3a of the core piece 3, a yoke 1 and yoke 7. Accordingly, when viewing from the coil side, magnetic resistance is reduced by the part of the collar part 3a of the core piece 3. Consequently, since the magnetic flux generated by the coil 6 passes the attracting face of the plunger 9 and the core piece 3 more than when there is not collar part 3a of the core piece 3, a difference between the attraction force when a current value is 0 and the attraction force in an operating point can be increased. The core piece 3 has a form capable of being pressed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a gas shutoff valve for use as a safety device in piping systems for supplying gaseous fuel.

Conventional technology In recent years, under administrative guidance, city gas supply companies and the LP gas supply industry have introduced 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 that closes the gas passage in the event of an abnormality.

An example of the conventional gas cutoff valve mentioned above will be described below with reference to the drawings.

FIG. 3 shows a longitudinal sectional view of a conventional gas cutoff valve. In FIG. 3, a permanent magnet 2 is placed at the bottom of a U-shaped magnetic yoke 1, and a core piece 3 is attracted onto it.
A guide pipe 4 made of non-magnetic metal is fitted outside the permanent magnet and the core piece, an electromagnetic coil 6 wound around a coil bobbin 5 is fitted around the outer periphery of the guide pipe 4, and a yoke 7 is fitted onto the coil bobbin 5. ing.

Cut and raised portions 1M are provided on both sides of the yoke 1, and a support 8 is fastened and fixed to the cut and raised portions 1a of C with screws. On the other hand, the movable part of the gas cutoff valve has a structure in which the plunger 9 is inserted into the guide pipe 4, with a valve rubber 10 fitted and attached to the tip of the plunger 9. In addition, there is an O-ring 11 inside the guide pipe 4, and an O-ring 1 outside the guide pipe 4.
2 is used to airtightly isolate between the gas passage side where the valve rubber 10 is located and the atmosphere side where the coil 6 and yoke 1 are located.

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

First, when the plunger 9 is pushed in with the setting rod 15, which is an operating rod for returning the valve, the attraction force of the permanent magnet 2, which is greater than the reaction force of the spring 13, is applied to the plunger 9 and the core piece 3.
It forms on the suction surface between the two, and is held as it is by suction. In this state, the valve rubber 10 is in the state where the valve seat 14 is open, and the tab valve is in the open state.

When the valve is closed, when the electromagnetic coil 6 is instantaneously energized in a direction that generates magnetic lines of force in the opposite direction to the permanent magnet 2, the core piece 3
The adsorption force between the plunger and the plunger r9 decreases, and the spring 13
When the reaction force becomes relatively large, the plunger 9 separates from the core piece 3, and the valve rubber 1° elastically contacts the valve seat 14 and closes.

Problem to be Solved by the Invention However, in the above configuration, in the diagram showing the relationship between the operating current value and the attraction force in Figure 2, the attraction force when the current is 0 is Plunger 9
Since the difference between the attraction force f at the operating point when the core piece 3 separates from the core piece 3, that is, F-f, is small, malfunctions occur due to external shocks, etc. In addition, it is economical that the core piece 3 has a structure that allows the parallelism and surface roughness of the attraction surface of the plunger 9 and the attraction surface of the permanent magnet 2 to be pressed very precisely. .

However, in the structure shown in FIG. 3, the suction surfaces on both sides of the core piece 3 must be finished separately, which makes it difficult to achieve parallelism and is uneconomical due to the high cost.

In view of the above-mentioned problems, the present invention provides a core piece that is reliable and does not malfunction due to external shocks, etc. by making a large difference between the adsorption force F when the current is 0 and the adsorption force f at the above-mentioned operating point. This provides an inexpensive gas cutoff valve that can be processed using a sheet metal press.

Means for Solving the Problems In order to solve the above problems, the gas cutoff valve of the present invention includes a permanent magnet that constantly attracts a plunger having a valve rubber at one end to keep the gas passage open, and a permanent magnet that is used in the event of an abnormality. an electromagnetic coil that excites a magnetic field in the opposite direction to the magnetic field of the plunger to separate the plunger from the core piece and close the gas passage; a guide pipe that guides the plunger, the core piece, and a coil bobbin around which the electromagnetic coil is wound; and a guide pipe for sealing. an O-ring, the core piece has a flange on the outer periphery,
It has a structure that guides a permanent magnet using sheet metal press processing.

Effects of the present invention With the above-described configuration, when a current instantaneously flows through the electromagnetic coil to release the plunger and the core piece from the magnetic force of the permanent magnet, the magnetic flux generated by the current flowing through the coil flows into the plunger, the core piece, and the flange of the core piece. It flows through the yoke and yoke. Therefore, when viewed from the coil side, the magnetic resistance is reduced by the amount of the magnetic path in the flange of the core piece. As a result, compared to the case where there is no flange of the core piece, the magnetic flux generated by the coil passes through the attraction surfaces of the plunger and core piece more, so there is a difference between the attraction force when the current value is 0 and the attraction force at the operating point. You will be able to get a large amount of Moreover, the core piece has a shape that can be pressed.

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, a permanent magnet 2 is placed at the bottom of a U-shaped magnetic yoke 1, a core piece 3 with a pressed collar 3 is placed on top of the permanent magnet 2, and a non-magnetic guide pipe 4 is placed outside the core piece. A coil bobbin 5, which is a winding of an electromagnetic coil 6, is fitted onto the outer periphery of the guide pipe 4, and a yoke 7 is fitted onto the coil bobbin 5. Further, cut and raised portions 1a are provided on both sides of the yoke 1, and the support 8 is fastened and fixed to the cut and raised portions with screws.

Further, the core piece 3 has a flange 3a and a permanent magnet 2 fitted therein.

On the other hand, the movable part of the gas cutoff valve has a structure in which the plunger 9 is inserted into the coil bobbin 5, with a valve rubber 10 fitted and attached to the tip of the plunger 9. An O-ring 11 is used inside the coil bobbin 5, and an O-ring 12 is used outside the coil bobbin 5 to airtightly isolate the gas passage side where the valve rubber 10 is located and the atmosphere side where the coil 6 and yoke 1 are located.

Regarding the gas cutoff valve configured as above, the following is the first part.
The operation will be explained using diagrams.

FIG. 1 is a longitudinal cross-sectional view of the gas cutoff valve when the valve rubber 10 of the gas cutoff valve is open and the gas passage is open during normal operation. First, when the plunger r9 is pushed in with the setting rod 15, the plunger 9 moves and comes into contact with the core piece 3.
Due to the magnetic flux of the permanent magnet 2 flowing through the plunger 9, core piece 3, yoke 1, and yoke 7, an attraction force that is greater than the reaction force of the spring 13 is generated on the attraction surface between the plunger 9 and the core piece 3, and the attraction force remains as it is. Retained. In this state, the valve rubber 10 is separated from the valve seat 14, and the valve is opened, allowing gas to flow in the direction of the arrow.

In the event of an abnormality, when the electromagnetic coil 6 is instantaneously energized to generate a magnetic field in the opposite direction to that of the permanent magnet 2, a magnetic force is generated by the electromagnetic coil 6 to reduce the attraction force between the core piece 3 and the plunger 9. do.

In this case, the magnetic flux flows through the plunger 9, the core piece 3, the flange 3a of the core piece 3, the yoke 1, and the yoke 7. Therefore, when viewed from the coil side, the magnetic resistance is reduced by the flange portion 3a of the core piece 3.

Effects of the Invention As described above, in the present invention, a flange can be provided on the core piece by pressing the core piece, and the passage resistance of the magnetic flux generated by instantaneous energization of the electromagnetic coil in the event of an abnormality is reduced. . Therefore, since there is a large difference between the attraction force of the permanent magnet when the coil current value is 0 and the attraction force at the operating point, it is possible to create a stable and reliable gas cutoff valve without detaching due to external impact force, etc. can be made.

Furthermore, since the core piece is made by pressing sheet metal, it is very inexpensive and has a large economical effect. In addition, since the core piece is press-drawn, it is possible to precisely finish the parallelism and surface roughness of both sides, thereby reducing variations in the operating characteristics of the shutoff valve.

In the embodiment, a case is illustrated in which a guide pipe 4 made of non-magnetic metal is used, but the same effect can be obtained even in the case of a structure in which the guide pipe and the coil bobbin 5 are integrally molded with resin without a guide pipe.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a gas cutoff valve according to an embodiment of the present invention, and FIG. 2 shows the relationship between the coil current value and the attraction force between the plunger and the core piece. FIG. 3 is a longitudinal sectional view of a conventional gas cutoff valve. 1... Yoke, 2... Permanent magnet, a.
...Core piece, 4...Guide pipe,
5... Coil bobbin, 6... Electromagnetic coil, 7... Yoke, 8... Support, 9
...Plunger, 10...Valve rubber. 1.-York? - Permanent stone 3 - Core piece 5 - Coil bobbin ≦ - Tami coil (1... - Valve rubber

Claims (1)

[Claims] A permanent magnet that constantly attracts a plunger with a valve rubber at one end to open the gas passage, and in the event of an abnormality, excites a magnetic field in the opposite direction to the magnetic field of the permanent magnet to detach the plunger from the core piece and close the gas passage. a guide pipe for guiding the plunger, a core piece, and a coil bobbin around which the electromagnetic coil is wound; and a sealing O-ring; A gas cutoff valve with a structure that guides a magnet.