JPS6136336B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetically driven gas shear breaker, the purpose of which is to prevent overheating in large current areas without sacrificing arc driving force in small current areas. The purpose is to alleviate electromagnetic repulsion.

Magnetically driven gas shield disconnectors are so-called self-acting disconnectors, so the arc driving force decreases in the small current range and the performance becomes unstable. To avoid this, it is possible to increase the number of turns of the drive coil, but since this type of device generally places the arc runner close to the coil, increasing the number of turns causes a strong electromagnetic repulsion between the two in a large current range. This causes problems in terms of strength.

This will be explained based on the conventional device shown in FIG. The figure shows a fixed contact 1 and a movable contact 2.
A cylindrical drive coil is wound coaxially with the arc runner 3 between the arc runner 3 and the flange of the fixed contact base 5. 4. The arc is rotated and extinguished by the magnetic flux φ generated by flowing a shear current. Note that 6 is an insulating sleeve that insulates between the drive coil 4 and the fixed contact 1, and the whole is housed in a container sealed and filled with an insulating arc-extinguishing gas such as SF ₆ gas. For simplicity, illustration is omitted.

In the above-mentioned configuration, in order to obtain sufficient rotational driving force in a small current range, the number of turns of the drive coil 4 can be increased. A strong electromagnetic repulsive force is generated between the runner 3 and it is difficult to obtain something strong enough to resist this electromagnetic repulsive force.

The present invention was proposed in view of the above points, and will be described below based on the embodiment shown in FIG.

FIG. 2 shows one embodiment of the present invention, in which a spring 7 such as a coil spring or a disc spring is inserted between the drive coil 4 and the flange portion of the fixed contact base 5, so that the coil 4 is always pressed and the arc The structure is such that it is brought close to the runner 3. Although it is not clearly shown in the figure, it is a matter of course that the fixed contact base 5, coil 4, and arc runner 3 are electrically connected, and the whole is covered with an insulating arc-extinguishing gas such as SF ₆ gas. It is stored in a hermetically sealed container (not shown).

In the above configuration, the electromagnetic repulsion force is small in the case of a break in a small current range, so the coil is in a state close to the arc runner, and the magnetic flux φ has little leakage and is effectively used for arc drive. Further, in the case of a break in a large current range, the electromagnetic repulsion force becomes large, so that the coil 4 moves upward in the figure against the spring 7. The electromagnetic repulsive force between the arc runner 3 and the coil 4 decreases as the distance between them increases, and the coil 4 stops at a point where it balances with the force of the spring 7. As the distance between the arc runner 3 and the coil 4 increases, the magnetic flux involved in arc drive will be relatively reduced compared to when both are close to each other, but even in that case, sufficient driving force cannot be obtained. By selecting the spring 7 to such an extent that a large current can be cut off, the structure of the above embodiment is a preferable structure in that it does not apply more than necessary driving force.

As explained above, according to the present invention, the drive coil has a structure that allows it to be separated from the arc runner, and in the case of a small current range or break, the arc runner and the drive coil are brought close to each other, thereby generating magnetic flux for arc drive. The electromagnetic repulsion between the arc runner and the coil is increased in the large current range, increasing the distance between the two, and reducing the electromagnetic repulsion. This has the remarkable effect of solving structural problems related to electromagnetic force.

[Brief explanation of the drawing]

FIG. 1 is a partially vertical front view showing a conventional device, and FIG. 2 is a partially longitudinal front view showing an embodiment of the present invention. 1... Fixed contact, 2... Movable contact, 3...
Arc runner, 4... Drive coil, 5... Fixed contact base, 6... Insulating sleeve, 7... Spring, 8
...Arc, φ...Magnetic flux.

Claims (1)

[Scope of Claims] 1. A fixed contact base having a flange at one end; A fixed contact provided on the flange side of the fixed contact base; An insulating sleeve provided to surround the fixed contact; a disc-shaped arc runner fixed to an end of the insulating sleeve; a drive coil movably inserted into the insulating sleeve between the disc-shaped arc runner and the flange of the fixed contact base; A gas shield and disconnector comprising: a compression spring provided between an end of a drive coil and a flange of the fixed contact base; and a movable contact corresponding to the fixed contact.