JPS594520Y2 - Vacuum cutter - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vacuum breaker having a vertical magnetic field electrode structure, and more particularly to a vacuum breaker with an improved reinforcing member that prevents deformation of the coil electrode due to impact when opening and closing the electrode.

The structure of a vacuum breaker having a vertical magnetic field electrode structure is already known, having been developed by the applicant and others.

An example of the structure is shown in Fig. 1 a, l).

1 is the main electrode, and an arc is generated on this surface when the current is interrupted.

2 is a coil electrode that extends radially from the current-carrying shaft 3;
A portion extending in the circumferential direction at the outer periphery and a portion connecting to the main electrode 1 2. A, and the current flowing through the paths of each part generates an axial magnetic field, that is, a longitudinal magnetic field, with respect to the arc column.

Reference numeral 4 denotes a reinforcing member, which is made of a material with higher resistance and mechanical strength than the coil electrode 2, such as stainless steel, so that the main electrode 1 and the coil electrode 2 are in contact with each other at a portion other than the connecting portion 2a of the main electrode 1. prevents you from doing so.

It is desirable to bond both the main electrode 1 side and coil electrode 2 sides of this reinforcing member 4 by a method such as brazing, but from the viewpoint of current flow, the main electrode 1 and coil electrode 2 are Since the top priority is to adhere the reinforcing member 4 to the main electrode 1 side or the coil electrode 2 side, the conventional method is to adhere the reinforcing member 4 only to either the main electrode 1 side or the coil electrode 2 side, and leave a slight gap on one side so that it is not bonded. Ta.

According to this, the adhesion between the main electrode 1 and the coil electrode 2 at the connecting portion 2a is reliably performed, and neither of the reinforcing member 4 and the main electrode 1 or the coil electrode 2 is able to withstand the impact when the electrode is inserted. Deformation of the coil electrode 2 by only one gap is sufficient to provide reinforcement against compressive force.

However, when high voltage and large current interruption are required and the opening/closing speed of the electrodes becomes faster, the following problems occur with the conventional reinforcing member structure.

As mentioned above, the reinforcing member 4 is sufficiently effective when the electrode is inserted, but the problem arises when the electrode is opened.

In the conventional reinforcing member structure, the main electrode 1 side or the coil electrode 2
- Since only one of the sides is bonded, there is no reinforcing effect against the force (tensile force) that pulls the main electrode 1 and coil electrode 2 together in the axial direction.

When the electrode is opened, a tensile force is applied to the electrode portion due to inertial force.

When the electrode opening speed is slow, this tensile force does not pose much of a problem, but the reinforcing member 4 has no effect on the tensile force caused by the faster electrode opening speed, so the peripheral part of the coil electrode 2 is warped. It changes shape.

If this deformation operation is repeated many times, there is a risk that the connecting portion 2a between the main electrode 1 and the coil electrode 2 will be damaged by fatigue.

In addition, there is a method to improve this drawback, that is, to reliably bond the main electrode 1 and the coil electrode 2 at the connecting portion 2a and to bond the reinforcing member 4 to both surfaces of the main electrode 1 and the coil electrode 2. It is necessary to process the electrode 1, coil electrode 2, and reinforcing member 4 with high precision, which requires a lot of time.

In addition, since the main electrode 1, coil electrode 2, and reinforcing member 4 are generally made of different materials, brazing requires a combination of the difference in coefficient of thermal expansion and fitting dimensions when bonding, etc., and requires high-precision processing. There are also limits.

The second drawback is that in order to increase the reinforcing effect, it is possible to make the reinforcing member 4 larger in diameter, but if this is done, the resistance ratio with the coil electrode 2 will decrease, and the reinforcing member 4 The current flowing through the electrode cannot be ignored, and the effect of the vertical magnetic field electrode structure cannot be fully obtained.

In order to improve this drawback, methods such as machining the round bar to make it hollow have been considered, but this has the drawback of requiring a large amount of material and processing time, making it expensive.

The present invention has been made to eliminate the above-mentioned drawbacks, and provides a vacuum breaker that is equipped with a coil electrode for generating a vertical magnetic field and can prevent the coil electrode from deforming when the electrode is opened and closed. The purpose is to

Hereinafter, the present invention will be described in a second diagram in which the same parts as in Figure 1 are given the same reference numerals.
This will be explained with reference to FIGS.

FIG. 2 is an example of the longitudinal magnetic field electrode structure of the present invention.

This structure differs from the conventional structure shown in FIG. 1 in that the reinforcing member 4 has a cylindrical portion formed by pressing or drawing from a single plate or a blank pipe, and at least one end of the reinforcing member 4 is 90' outward. It has a shape that is bent as follows and the curvature of the bent portion is greater than the plate thickness, and the bent portion has a slit at at least one location in the axial direction.

As for the material, for example, a type of stainless steel is used, which has a spring property against vertical compression in the above-mentioned shape.

This reinforcing member 4 is attached to the connecting portion 2 between the electrode 1 and the coil electrode 2.
Set the reinforcing member 4 in a state where it can be reliably bonded and is slightly compressed to the main electrode 1 and the coil electrode 2, that is, the bending angle of the reinforcing member 4 is close to 90°, and in this state, brazing is performed by a method such as It is attached to both the main electrode 1 and the coil electrode 2.

At this time, the slits in the reinforcing member 4 are filled by the surface tension of the brazing material, capillary action, and the like.

According to the configuration of the present invention as described above, the following effects can be obtained.

First, the reinforcing member 4 can be reliably bonded to both the main electrode 1 and the coil electrode 2 together with the bonding portion 2a of the main electrode 1 and the coil electrode 2 without requiring high-precision machining.

This makes it possible to obtain reinforcement against the force (tensile force) that pulls out the main electrode 1 and the coil electrode 2 in the axial direction, which could not be obtained with conventional reinforcing members.

Furthermore, when bonding the main electrode 1 and the coil electrode 2 of the reinforcing member 4, the slit made in the reinforcing member 4 is filled with the brazing filler metal as described above. After adhering to the coil electrode 2, the reinforcing member 4 loses its springiness, and the compressive impact force at the time of injection has a force (tensile force) that pulls out the main electrode 1 and the coil electrode 2 in the axial direction, which could not be obtained with conventional reinforcing members. sufficient reinforcement can also be obtained against force.

Furthermore, since the reinforcing member 4 is formed from a single plate or a pipe, even if the diameter of the reinforcing member 4 is made larger in order to increase the reinforcing effect, the cross-sectional area of the reinforcing member 4 is small. The resistance ratio with the coil electrode 2 does not decrease, and it can be manufactured easily and inexpensively compared to methods such as machining.

FIG. 4 shows a reinforcing member 4 according to another embodiment of the present invention, and when the material of the reinforcing member 4 has high elasticity, it is not necessary to provide a slit in the bent portion of the reinforcing member. Good too.

However, in this case as well, since the height of the reinforcing member 4 is small, the surface tension of the solder causes the reinforcing member 4 to
A similar effect can be obtained because the sides of the plate are hardened with brazing filler metal.

This embodiment can also be used for materials whose springiness is naturally lost due to heat treatment such as brazing.

Due to the above effects, a high quality and inexpensive vacuum breaker can be provided.

[Brief explanation of the drawing]

Figure 1 shows a conventional vertical magnetic field electrode, where a is a plan view and b is a plan view.
1A is a side view taken along the line A-A in FIG. It is a side view of the reinforcing member which shows an Example. 1... Main electrode, 2... Coil electrode, 3
...... Current-carrying shaft, 4... Reinforcement member, 2a.
・・・・・・Adhesive part between main electrode and coil electrode.

Claims (2)

[Scope of utility model registration request] (1) A pair of main electrodes that can be relatively moved toward and away from each other are arranged opposite each other in a vacuum vessel, and the electrode is arranged on the back side of the main electrode and connected to the main electrode, parallel to the arc generated between the main electrodes. Equipped with a coil electrode that generates a magnetic field,
This coil electrode is fixed to the current-carrying shaft, and a molded reinforcing member is placed between the opposing surfaces of the current-carrying shaft end and the main electrode, and this reinforcing member is arranged so that at least one end of the cylindrical portion is directed outward by 90 degrees or less. A vacuum breaker constructed by bending the curvature of the bend to be greater than the plate thickness. (2) The vacuum breaker according to claim 1, which has a slit at least at one location in the axial direction in the outwardly bent portion of the reinforcing member.