JPS5847629Y2 - Vacuum cutter - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a vacuum breaker.

Generally, a vacuum breaker is constructed by arranging a fixed electrode and a movable electrode facing each other in a vacuum container, and current is applied by moving the movable electrode toward and away from the fixed electrode.

It is shutting off.

However, when breaking, an arc is generated between the electrodes, and if the breaking current is large, this arc receives electromagnetic force in the direction of the electrode's outer circumference due to the interaction between the magnetic field generated by the arc itself and the magnetic field created by the external circuit, and the arc It leans toward the outer periphery and locally heats that area, generating a large amount of metal vapor.

For this reason, metal vapor remains between the electrodes after the current reaches zero, delaying insulation recovery and reducing the breaking ability.

Conventionally, as a countermeasure against this problem, applying an axial magnetic field to the arc has been carried out.

An example is shown in FIG.

In the figure, 1 is an insulating tube, 2 and 3 are end plates attached to both ends of the insulating tube 1, 4 is a fixed electrode rod inserted into the end plate 2,
Reference numeral 5 indicates a movable electrode rod which is inserted through the end plate 3 and is attached to the end plate 3 via a bellows 6; 7 and 8 are each electrode rod 4;
A fixed electrode and a movable electrode are respectively attached to the tips of the insulating cylinder 1. end plate 2,
3 and bellows 6 form a vacuum container.

The movable electrode 8 has a base 9 attached to the tip of the movable electrode rod 5.
a contact electrode 9 having a coil portion 9b extending in a coil shape from a base portion 9a; a contact electrode 11 attached to the base portion 9a via a spacer 10 made of a high resistance material such as stainless steel; 9b is attached to the recess 9C at the tip of the contact electrode 11, and the other end is attached to the recess 11a of the contact electrode 11.
Similarly, the fixed electrode 7 is composed of a coil electrode 13, a spacer 14, and a connecting conductor 12 attached to it. It is composed of a contact electrode 15 and a connecting conductor 16.

In the vacuum breaker with this configuration, the cutoff current at the time of cutoff is: movable electrode rod 5 - coil electrode 9 - connection conductor 12 - contact electrode 1
1-Arc-contact electrode 15-Connecting conductor 16-Coil electrode 13-Fixed electrode rod 4 flow, each coil electrode 9,1
3 generates an axial magnetic field.

Therefore, an axial magnetic field is applied to the arc, and charged particles such as electrons and ions carrying the arc current are trapped in this magnetic field, preventing the concentration of the arc, and each contact electrode 11.15 generates a large amount of metal vapor due to local heating. This will no longer occur, and the shutoff ability can be improved.

By the way, when the vacuum breaker is in the closed state, the contact electrode 11.
It is electrically and mechanically desirable that the contact surfaces 11b, 15a of 15 are in full contact with each other, and for this purpose it is necessary that the contact electrodes 11.15 are placed parallel to the coil electrodes 9, 13, respectively.

However, in the above vacuum breaker, for example, in the movable electrode 8, both ends of the connecting conductor 12 are provided between the recess 11a of the contact electrode 11 and the recess 9C of the coil electrode 9 (1'), and the spacer 10 is provided between the recess 11a of the coil electrode 9. It is provided between the four parts 9d provided on the base 9a and the recess 11C of the contact electrode 11.

Therefore, if there is a manufacturing error in the length of the spacer 10 or contact electrode 12 or the depth of each recess 9C, 9d, 11a, 11C, the contact electrode 11 will not be parallel to the coil electrode 9, and the contact surface 11b will be Only a portion of the contact surface 15a came into contact with the contact surface 15a, resulting in a reduction in the current-carrying area and weakening of the mechanical strength.

Furthermore, since the connecting conductor 12 made of a highly conductive material such as copper and the spacer 10 made of a high resistance material such as stainless steel are made of different materials, their thermal expansion coefficients are also different, and as a result, the contact electrode 11 sometimes tilts during brazing. This caused problems such as:

The present invention is a vacuum breaker that can eliminate the above-mentioned drawbacks and improve the breaking ability by generating an axial magnetic field, and the contact electrode is kept parallel to the coil electrode. An object of the present invention is to provide a vacuum breaker whose surface can be brought into full contact with a counter electrode.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 17 denotes a coil portion 17C that is attached to a protrusion 18a provided at the tip of the electrode rod 18 via a recess 17b provided on one side of the base 17a, and extends in a coil shape from the base 17a. a coil electrode,
Reference numeral 19 denotes a cylindrical spacer made of a high-resistance material, one end of which is attached to four parts 17d provided on the other surface of the base 17a;
0 is a contact electrode attached to the other end of the spacer 19 via a recess 20a, and an axial through hole 20b is provided in the outer circumference of the contact electrode 20.

A connecting conductor 21 has one end attached to a recess 17e provided at the tip of the coil portion 17C, and the other end of the connecting conductor 21 is inserted into a through hole 20b and provided with a protrusion 21a. The through hole 20b is brazed through the brazing material 22 around the area a.

In a vacuum breaker with this structure, one end of the connecting conductor 21 is inserted into the through hole 20b, so the length of the spacer 19 and the connecting conductor 21, or the recesses 17b, 17d, 17
Even if there is a manufacturing error in the depth of 20a, the distance between the coil electrode 17 and the contact electrode 20 is maintained only by the spacer 19 during assembly, and the contact electrode 20 will not tilt due to the manufacturing error.

In addition, brazing sometimes generates stress due to the difference in thermal expansion coefficient between the spacer 19 and the connecting conductor 2, but this stress is absorbed by the sliding between the connecting conductor 21 and the through hole 20b, and the contact electrode 20 is It is not a tilting force.

Therefore, the contact surface 20C of the contact electrode 20 is in full contact with the counter electrode.

FIG. 3 shows another embodiment of the present invention, in which one end of the connecting conductor 23 is attached to the recess 17e of the coil electrode 17, and the other end of the connecting conductor 23 is inserted into the through hole 20b, and the four annular parts 23a A brazing material 22 is housed in the four parts 23a and is fixed to the through hole 20b via the brazing material 22.

The tip of the connecting conductor 23 is inclined to match the surface of the contact electrode 20.

This example is the same as the previous embodiment except for the installation position of the brazing material 22, and the effects are also the same.

As described above, in the present invention, one end of the connecting conductor is attached to the coil electrode, and the other end is inserted into the through hole provided in the axial direction on the outer periphery of the contact electrode. The only member that maintains the distance between them is the spacer,
The contact electrode is not tilted.

In addition, when brazing, the stress due to the difference in thermal expansion coefficient between the spacer and the connecting conductor is absorbed by the sliding movement of the connecting conductor and the through hole.
The contact electrode does not tilt.

Therefore, the contact electrode is kept parallel to the coil electrode, and its contact surface is in full contact with the counter electrode, ensuring a current flow area and mechanical strength.

Note that the electrode structure according to the present invention can be applied to both a fixed electrode and a movable electrode, but it may be applied to either one.

[Brief explanation of drawings]

1A and 1B are a longitudinal sectional front view and an enlarged longitudinal sectional front view of a movable electrode portion of a conventional vacuum breaker, respectively, and FIGS. 2 A and B are a longitudinal sectional front view and an enlarged longitudinal sectional front view of an electrode portion of a vacuum breaker according to the present invention, respectively. FIG. 3 is a plan view of a coil electrode, and FIG. 3 is a longitudinal sectional front view of an electrode portion of a vacuum breaker according to another embodiment of the present invention. 1... Insulating cylinder, 2, 3... End plate, 4.
...Fixed electrode rod, 5...Movable electrode rod, 6
...Bellows, 17...Coil electrode,
17 a... Base, 17 C... Coil part, 18... Electrode rod, 19... Spacer, 20... Contact electrode, 20b・・・・・・
・Through hole, 20 C...Contact surface, 21, 23・
...Connecting conductor.

Claims (1)

[Scope of utility model registration request] A vacuum breaker in which a pair of electrodes are disposed facing each other in a vacuum container so that they can be brought into contact with each other through electrode rods. a coil electrode that generates a directional magnetic field; a contact electrode that is attached to the base of the coil electrode via a spacer made of a high-resistance material and has an axial through hole in the outer periphery;
A vacuum breaker characterized in that at least one electrode is constituted by a connecting conductor having one end attached to a coil portion and the other end inserted into a through hole of a contact electrode.