JPH0637945B2 - Self-holding gas cutoff valve - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a self-holding device for a safety device which is installed in a gas pipe portion of a gas meter, a gas fuel instrument or the like, and which is activated by a driving power source when an abnormal situation occurs to shut off a gas passage. Type gas shutoff valve.

2. Description of the Related Art Generally, in a self-holding type gas cutoff valve, as in the conventional example shown in FIG. 2, a magnetic circuit 6 is formed by a permanent magnet 1, a yoke 2 made of a magnetic material, a sub-yoke 3, a plunger 4, an attracting piece 5 and the like. The plunger 4 and the suction piece 5 are suctioned by the suction surface 7. A ben rubber 8 is attached to the tip of the plunger 4. When a voltage is applied to the coil 9 so that a magnetic field opposite to the magnetic field direction of the magnetic circuit 6 is applied when an abnormality occurs, the attraction force between the attraction piece 5 and the plunger 4 on the attraction surface 8 weakens, The repulsive force of the spring 10 pushes the Ben rubber 8 mounted on the plunger 4 upward.

That is, although not shown in the figure, there is a valve seat above the rubber bell 8 to close the gas passage.

In this case, for safety reasons, it is necessary to isolate the part of the coil 9 that becomes the current-carrying part from the gas atmosphere, and the central hole of the coil bobbin 11 is made of non-magnetic metal to reduce the influence on the magnetic circuit 6. The straight pipe 12 is inserted, and packing seal materials 14 and 15 are provided between the outer periphery of the adsorption piece 5 and the pedestal 13 for gas sealing.

The problem to be solved by the invention is that, in the case of such a structure, in order to improve the gas sealing effect in the seal packing 14, a certain thickness is required, and as a result, the outer diameter of a part of the adsorption piece 5 is reduced. There must be. However, since the magnetic flux of the permanent magnet 1 is efficiently supplied to the magnetic circuit 6, the magnetic path cross-sectional area cannot be made smaller than a certain limit. If the outer diameter corresponding to the required minimum cross-sectional area is φA, the outer edge dimension of the suction piece 5 is φB = φA + (thickness of the seal packing material 14−compression allowance) × 2, and φB> φA.

On the other hand, the outer diameter of the plunger 4 moving in it may be about the same as φA considering the minimum required cross-sectional area. However, since the pipe 12 is straight, the outer diameter of φA is the inner diameter of the pipe 12. A large gap is generated between them and the plunger 4 fluctuates in the range of the gap, and the operation cannot be stable.

Therefore, the outer diameter of the plunger 4 needs to be approximately the same as the diameter φB of the outer edge of the suction piece 5.

That is, although the outer diameter of the plunger 4 may be small in characteristics and performance, it must be increased in structure, resulting in a waste of material.

Further, since the plunger itself has a large weight, it is apt to be naturally actuated, that is, malfunction due to an external impact at the time of adsorption.

MEANS FOR SOLVING THE PROBLEMS The self-holding type gas cutoff valve of the present invention is an adsorption piece having an outer edge portion and an adsorption portion having an outer diameter smaller than the outer diameter thereof, and a part of the outer diameter of the adsorption portion. Insert the non-magnetic metal integral pipe with the expanded part with one end expanded to fit the outer diameter of the outer edge part into the central hole of the drive coil A gap is provided between the end surface and the inner end surface of the pipe expanding portion, and a seal packing material is provided on the outer diameter of the suction portion and the inner circumference of the pipe expanding portion.

Operation The self-holding type gas cutoff valve of the present invention uses the integral pipe having the expanding portion to share the outer diameter of the gas seal portion of the adsorption piece and the outer diameter of the adsorption surface portion, so that the plunger diameter is also required. It can be minimized.

Embodiment Hereinafter, a self-holding type gas cutoff valve according to an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the suction piece 5 includes a suction portion 5a (having an outer diameter of φA ′) having a suction surface 7 and an outer edge portion 5b (having an outer diameter of φB ′). . A pipe 12 having an inner diameter substantially equal to φA ′ is inserted into a central hole of a coil bobbin 11 around which the coil 9 is wound, and a lower portion of the pipe 12 has an inner diameter substantially equal to φB ′.
I have 2 '.

A vertical gap is provided between the end surface of the suction piece outer edge portion 5b on the suction piece suction portion 5a side and the end surface of the pipe expanding portion 12 '. A seal packing material 14 is mounted between the outer diameter of the suction portion 5a and the inner diameter of the pipe expanding portion 12 'with a compression margin added.

Inside the pipe 12, the plunger 4 whose outer diameter is close to φA '
Has been inserted.

Descriptions of other components are the same as those of the conventional example shown in FIG.

Now, with the above configuration, it is natural that φB '> φ
A ′, and φB ′ = φA ′ + (seal packing material 14
Thickness-compression allowance) × 2.

Here, as described in the embodiment, when φA ′ is a diameter corresponding to the minimum required cross-sectional area in terms of magnetic circuit characteristics, the outer diameter of the plunger 4 is also a diameter close to φA ′, so that the minimum required cross-sectional area is equivalent. It will be the diameter.

EFFECTS OF THE INVENTION As described above, the self-holding type gas cutoff valve of the present invention uses the integral pipe having the expanding portion to share the outer diameter of the gas seal portion of the adsorption piece and the outer diameter of the adsorption surface portion. The outer diameter of the plunger can be minimized.

As a result, unnecessary waste of the material of the plunger can be eliminated, the cost can be reduced, and the weight can be reduced, so that the impact resistance against the impact from the outside can be improved.

Further, since the diameter of the central hole of the coil bobbin can be reduced, the outer diameter of the coil itself can be reduced, and the shutoff valve can be downsized.

[Brief description of drawings]

FIG. 1 is a sectional view of a self-holding type gas cutoff valve according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional example. 5 ... adsorption piece, 9 ... coil, 12 ... pipe, 14 ...
… Seal packing material.

Claims (1)

[Claims] 1. An adsorption piece having an outer edge portion and an adsorption portion having an outer diameter smaller than the outer diameter thereof, and an inner diameter for accommodating a part of the outer diameter of the adsorption portion and having an outer diameter of the outer edge portion. A non-magnetic metallic metal integrated pipe having a pipe expanding portion whose one end is expanded so as to fit and a non-magnetic metallic metal integrated pipe inserted into the drive coil central hole; and an end surface of the outer edge portion on the adsorption portion side and an inner end surface of the pipe expanding portion. A self-holding type gas cutoff valve having a gap provided between the suction portion outer diameter and the pipe expanding portion and a seal packing material.