JPS6213324Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode structure for a vacuum fuse having an electrode structure that generates an axial magnetic field when a fuse element is blown.

Conventionally, some vacuum fuses of this type have a fuse element that can be fused between opposing conductor axes, disk-shaped electrodes with a hole in the center that are arranged opposite each other, and a spiral conductor plate on the back side. There is a fuse element that is installed to generate an axial magnetic field when the fuse element blows, improving the interrupting performance.
7254).

FIG. 1 shows a conventional example of the electrode structure of the vacuum fuse described above, and since both electrode structures disposed facing each other have the same shape, only one electrode structure is shown.

Reference numeral 1 denotes a fuse element that can be fused and is connected to a conductor shaft 3 through a disk-shaped electrode 2 having a hole in the center. Reference numeral 4 denotes a spiral conductor plate, the central end of which is connected to the conductor shaft 3, and the outer peripheral end connected to the outer peripheral inner wall surface of the electrode 2. A spacer 5 is made of a high resistance material such as stainless steel and is inserted between adjacent conductors of the spiral conductor plate 4.

However, in this configuration, the spiral conductor plate 4
The central end of the conductor shaft 3 is fixed to the side surface of the conductor shaft 3, and the outer peripheral end thereof is fixed to the outer peripheral inner wall surface of the electrode 2 by brazing with arcuate contact surfaces. Since there are two arcuate contact surfaces, the spiral conductor plate 4 can easily rotate and move.
It had the drawback that it was difficult to fix and the brazing was unstable.

Furthermore, the magnetic field generated by the spiral near the center of the spiral conductor plate 4 acts in a direction that lowers the magnetic field generated by the spiral on the outer peripheral side at the outer periphery of the electrode surface, so the axial magnetic field is stronger at the center. In the end, the arc was confined to the center, and the effective use of the electrode was impaired, resulting in the need for a large electrode in order to obtain a large breaking ability, and the drawback was that the vacuum fuse was large.

The present invention was devised to eliminate these drawbacks, and its features include the provision of arms extending in the radial direction at the center of the spiral conductor plate;
In addition to being securely fixed to the conductor shaft, a spiral portion is provided on the outer periphery of the back surface of the electrode so that the arc generated after the fuse element is blown spreads uniformly over the entire surface of the electrode.This will be explained in detail below with reference to the drawings.

Hereinafter, since both electrode structures according to the present invention have the same shape, only one electrode structure will be described.

FIG. 2 is a longitudinal sectional view showing the electrode assembly 10 of the first embodiment according to the present invention, and FIG.
A cross-sectional view taken from line A is shown, and the same parts are designated by the same reference numerals.

11 is a fuse element, 12 is an electrode, 13
is a conductor shaft, 14 is a spiral conductor plate, 15a, 15b
is a spacer made of a high resistance material such as stainless steel. Here, the spiral conductor plate 14 has an arm portion 14a extending in the radial direction at the center thereof, and a first slit 14b is formed at a predetermined depth so that the fuse element 11 can be inserted into the center portion. It has a double spiral configuration with a

FIG. 4 is a perspective view showing the end of the conductor shaft 13, in which a partially arcuate groove is formed at a predetermined depth so that the fuse element 11 and the arm portion 14a of the spiral conductor plate can be inserted. a second slit 13 having
A is provided. The respective parts are assembled as follows. That is, first, the spacers 15a and 15b are closely inserted between adjacent conductors of the spiral conductor plate 14. Next, the second
The arm portion 14a and the fuse element 11 are fitted and inserted into the slit 13a, the electrode 13 is fitted and inserted into the outer periphery of the spiral conductor plate 13, and the fitting portions are fixed by brazing.

With this configuration, it is possible to prevent the rotational movement of the spiral conductor plate 14 and the conductor shaft 13 during assembly, allowing stable brazing, and the helical portion of the spiral conductor plate 14 is connected to the electrode. Since the arc is located toward the outer periphery of the back surface, the arc is not confined to the center of the electrode and spreads uniformly over the entire surface of the electrode, allowing effective use of the electrode.

FIG. 5 is a longitudinal sectional view showing an electrode assembly 20 according to a second embodiment of the present invention, in which the same or similar parts as in the first embodiment described above are designated by the same reference numerals. In this embodiment, a cup-shaped support flange 21 made of high resistance material such as stainless steel is added to the above-described embodiment.

FIG. 6 is a perspective view of the support flange 21, the bottom of which has an opening 21a that fits into the conductor shaft 13.
, and the cylindrical portion has the spiral conductor plate 1 at the opposing portion.
4 through the third slit 2.
1b and 21c. The cylindrical portion of the support flange 21 is assembled so as to be in close contact with the center-side spiral portion of the spiral conductor plate 14. In the case of this embodiment, in order to prevent the arm portions 14a of the spiral conductor plate 14 from deforming and to securely hold them, the thickness of the spiral conductor plate 14 is made thinner and the number of turns is increased. It has the advantage of generating a strong magnetic field.

FIG. 7 is a longitudinal sectional view showing an electrode assembly 30 according to a third embodiment of the present invention, in which the same or similar parts as in the first and second embodiments described above are designated by the same reference numerals. In this embodiment, a disk-shaped support disk 31 made of high resistance material such as stainless steel is added to the first and second embodiments described above.

FIG. 8 is a perspective view of the support disk 31, and the center portion is a first opening 31a that fits into the conductor shaft 12.
and a plurality of second openings 3 surrounding it.
1b, 31c, 31d, 31e, 31f, 31
g, 31h, 31i. The outer peripheral portion 31j of the support disk 31 is fixed to the electrode 12, and the first opening 31a is fixed to the conductor shaft 13 by brazing. In the case of this embodiment, since the electrode 12 is firmly fixed to the conductor shaft 13, it is possible to prevent the two electrodes from attracting and moving when the generated magnetic field is relatively large, resulting in a stable electrode configuration. I can donate my body. Note that the second openings 31b to 31i shown in this embodiment limit the current flowing through the support disk 31 when the interrupting current is applied.
This is provided in order to allow the breaking current to flow as much as possible through the spiral conductor plate 14 and generate a stronger magnetic field.In consideration of mechanical strength, it is not necessary to provide this, and it is also possible to use a slit-shaped opening. Good as a club.

In the first to third embodiments described so far, all the spiral conductor plates are double-wound, but may be single-wound or triple-wound or multiple-wound.

As explained above, according to the present invention, the arm portion extending radially from the center of the helical conductor plate is fixed to the conductor shaft, the helix of the helical conductor plate is firmly held while located on the outer periphery of the back surface of the electrode, and the arc can be spread over the entire surface of the electrode, so that the number of spiral turns can be effectively increased without making the electrode larger, resulting in an electrode structure that generates a strong and stable magnetic field, and a small vacuum fuse with excellent breaking ability can be realized.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing the electrode structure of a conventional vacuum fuse, FIG. 2 is a vertical cross-sectional view showing the electrode structure of the first embodiment of the present invention, and FIG. 3 is a cross-sectional view of the same embodiment. 4 is a perspective view showing the conductor shaft of the same embodiment, FIG. 5 is a longitudinal sectional view showing the electrode assembly of the second embodiment of the present invention, and FIG. 6 is a support flange of the same embodiment. FIG. 7 is a longitudinal sectional view showing an electrode assembly according to a third embodiment of the present invention, and FIG. 8 is a perspective view showing a support disk of the third embodiment. 11... Fuse element, 12... Electrode,
13...Conductor shaft, 13a...Slit for inserting the spiral conductor plate arm part, 14...Spiral conductor plate, 14a...
...Arm portion, 14b...Slit for fuse element insertion, 15a, 15b...Spacer, 21...
Support flange, 31...Support disk.

Claims (1)

[Scope of utility model registration request] A conductor that can be fused and cut is connected between conductors that are arranged oppositely in a vacuum container, and approximately disk-shaped electrodes with a hole in the center are placed facing each other between the conductors, and that the fusion-cuttable is possible during the opening. one end of a spiral conductor plate disposed concentrically with the conductor axis on the back surface of the electrode is connected to the conductor axis, and the other end is connected to the electrode. In the electrode structure of a vacuum fuse in which a high-resistance material is interposed between adjacent conductors to generate a magnetic field in the axial direction of the conductor at the time of fusing, the spiral conductor plate has an arm portion extending in the radial direction at the center thereof. A slit is provided at the end of the conductor shaft, and the arm portion is fitted and fixed to the slit.