JPH0547274A - Vacuum valve - Google Patents

Abstract

PURPOSE:To improve a withstand voltage between contacts by jointing a conical reinforcement cylinder with the coil electrode and an energization shaft for reinforcing the coil electrode and a contact member for preventing them from deformation at an outer circumference in switching a current, and shielding an angular part of the coil electrode. CONSTITUTION:For a reinforcement cylinder 9 composed of a conical metal of which end aperture diameters are different from each other, its inner wall surface is jointed with an outer circumferential surface on the counter-contact member side of a coil electrode 5, and the thinner-diameter aperture part is jointed with an outer diametric surface of an energization shaft. The larger- diameter aperture part of the cylinder 9 surrounds the whole outer circumference of the electrode 5 through a space, and the end part of the aperture part is rounded. Deformation of the outer circumferential part of the electrode 5 is thus restricted, an angular part of the electrode 5 is shielded by a roundness at the aperture end part and a smooth outer wall surface for an electric field, and concentration of the electric field is restricted to improve the withstand voltage between contacts, thereby the reliability 9 of its insulation can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve having an axial magnetic field electrode structure for forming a magnetic field parallel to an arc generated between contacts.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a structural example of a conventional vacuum valve. A movable contact 4A and a fixed contact 4B are housed facing each other in a vacuum tank 3 composed of a cover plate 2 airtightly joined to both ends of an insulating cylinder 1 to form a contact. Coil electrodes 5 are joined to the contacts 4A and 4B, respectively. Each of the coil electrodes 5 has a current-carrying shaft 6A,
6B is joined, and the current-carrying shafts 6A, are airtightly drawn to the outside via the bellows 7, and the current-carrying shafts 6B penetrate the cover plate 2 directly and airtightly and are drawn to the outside.

FIG. 5 is a plan view of the contactor 4A or 4B shown in FIG. 4 viewed from the facing surface thereof. A coil electrode 5 (dotted line) is arranged on the back surface of the contactor 4. The coil electrode 5 includes an arm portion 5B radially extending from the central portion 5A in four directions, a circumferential portion 5C circumferentially extending on the outer circumference, and a joint portion 5D joined to the contactor 4. FIG. 6 is a sectional view taken along the line AA of FIG. 5, in which the central portion 5A of the coil electrode 5 is fixed to the current-carrying shaft 6. On the other hand, the joint portion 5D of the coil electrode 5 is the joint surface 5
It is joined to the back surface of the contactor 4 via E. The central portion 5A of the coil electrode 5 is joined to the central portion of the contactor 4 via the reinforcing portion 8A and the reinforcing ring 8B (for example, Japanese Utility Model Publication No. 63-25632).

In FIGS. 5 and 6, a large current flows from the energizing shaft 6 to the coil electrode 5 at the central portion 5A and the arm portion 5 when the current is cut off.
B, the circulating portion 5C, the joining portion 5D in this order, and the joining surface 5E
To the contactor 4 via. Since the electric current flows in the circumferential direction in the circulating portion 5C, a magnetic field (axial magnetic field) parallel to the arc generated between the contacts is generated. The dissipation of ions and electrons by this axial magnetic field can be captured, and the arc can be stably ignited on the entire surface of the contactor 4. This prevents the contactor 4 from being locally melted by the arc.

The reinforcing portion 8A and the reinforcing ring 8B shown in FIG.
Is made of a material having a higher resistance than the coil electrode 5 and a high mechanical strength, such as a stainless material. When the contactor 4 is opened and closed, the coil electrode 5 and the contactor 4 are deformed by a shock,
In order to prevent the contactor 4 and the coil electrode 5 from coming into contact with each other except the contact surface 5E, the reinforcing portion 8A and the reinforcing ring 8B fix the coil electrode 5 and the contactor 4 at the center.

[0006]

However, the conventional device as described above has the problems that the outer peripheral portion of the coil electrode is easily deformed and that the withstand voltage between the contacts is low. That is, in the conventional device, the coil electrode and the contactor are fixed only at the central portion by the reinforcing portion and the reinforcing ring. Therefore, due to the impact when the current is cut off, the outer circumference of the coil electrode arm and the coil electrode surrounding part are deformed, or the contactor is tilted, and the coil electrode and the contactor come into contact with each other on a joint surface not provided in advance. There was a possibility that it would go down. As the breaking current increases, the amount of deformation and the inclination thereof increase, which hinders upgrading of the breaking capacity of the vacuum valve. Further, since the coil electrode has many corners, the electric field is concentrated, and the withstand voltage between the contacts is determined by the structure of the corners.

An object of the present invention is to reinforce the coil electrode and the contactor so that they are not deformed at their outer circumferences when the current is switched, and to shield the corners of the coil electrode and improve the withstand voltage between the contacts. ..

[0008]

In order to achieve the above object, according to the present invention, a contact housed in a vacuum tank made of an insulating tube and facing each other so as to be able to come into contact with and separate from each other, and an opposite surface of the contact. And a coil electrode having one end connected to the contact and forming a magnetic field parallel to the arc generated between the contacts, and the other end of the coil electrode and the end portion being a vacuum tank. A reinforcing cylinder, which is composed of a current-carrying shaft that is airtightly drawn to the outside of the coil and has an inner wall surface joined to the outer peripheral portion of the coil electrode opposite to the contactor side. The thin opening of the reinforcing cylinder is joined to the current-carrying shaft, and in such a configuration, the thick opening of the reinforcing cylinder surrounds the entire outer circumference of the coil electrode with a gap and Circle at the end of the part It shall have provided further metallic reinforcing plate disposed within the reinforcing tube, and that is joined to the reinforcing tube with the reinforcing plate is bonded to the non-opposing face of the contact.

[0009]

According to the structure of the present invention, the metallic flap-shaped reinforcing cylinder having different opening diameters at both ends is arranged so that its inner wall surface is joined to the outer peripheral portion of the coil electrode opposite to the contactor side. Further, the thin opening of the reinforcing cylinder is joined to the current-carrying shaft. With this configuration, the reinforcing cylinder fixes the outer peripheral side of the coil electrode entirely, so that the deformation of the outer peripheral portion of the coil electrode can be suppressed.

According to the structure of the present invention, in the above structure, the thicker opening of the reinforcing cylinder surrounds the entire outer circumference of the coil electrode with a gap, and the end of the opening is rounded. Was established. With this configuration, the corners of the coil electrode are shielded by the electric field, so that the withstand voltage between the contacts is improved.

Further, according to the structure of the present invention, in addition to the above structure, a metallic reinforcing plate is arranged inside the reinforcing cylinder, and the reinforcing plate is joined to the opposite surface of the contactor and is joined to the reinforcing cylinder. Was also joined. With this configuration, the contactor is entirely reinforced and its inclination can be suppressed.

[0012]

EXAMPLES The present invention will be described below based on examples.
FIG. 1 is a plan view of a contactor of a vacuum valve according to an embodiment of the present invention as viewed from its facing surface. The reinforcing cylinder 9 is arranged on the outer circumference of the contact 40. Since other configurations are the same as those of the conventional configuration shown in FIG. 5, the same reference numerals are used for the same portions, and detailed description thereof will be omitted. FIG. 2 shows B- of FIG.
It is a B sectional view. The reinforcing cylinder 9 is made of a metal having a different shape with different opening diameters at both ends. The inner wall surface of the reinforcing tube 9 is joined to the outer peripheral surface 5F of the coil electrode 5, and the narrow opening 9A of the reinforcing tube 9 is joined to the outer diameter surface of the energizing shaft 60. In addition, the thicker opening 9B of the reinforcing tube 9 is
The entire outer circumference of the coil electrode 5 is surrounded by a gap 10 and the end of the opening 9B is rounded.

In FIG. 2, the reinforcing cylinder 9 is made of a material having a higher resistance than the coil electrode 5 made of a copper material and a high mechanical strength, such as austenitic stainless steel. As a result, the deformation of the coil electrode 5 is suppressed, and most of the current flows to the coil electrode 5 side. In the method of joining the members in the configuration of FIG. 2, the members are joined by heating and welding the whole body after preliminarily assembling the surfaces 5E, 5F, 9A to be joined with silver solder. Thick opening 9 of the reinforcing tube 9
B is rounded by rounding its end to the inner diameter side. The corners of the coil electrode 5 are electrically shielded by the roundness and the smooth outer wall surface of the reinforcing cylinder 9. Therefore, the electric field concentration is relaxed and the withstand voltage between the contacts is improved. In addition to the configuration of FIG. 2, the opening 9B may be rounded by rounding the end of the reinforcing tube 9 toward the outer diameter side. Further, a metal ring having a circular cross section may be joined to the end of the reinforcing tube 9.

FIG. 3 is a cross-sectional view of essential parts showing the structure of a vacuum valve according to another embodiment of the present invention. The metallic reinforcing plate 11 is arranged inside the reinforcing tube 90. Further, the reinforcing plate 11 is entirely bonded to the back surface of the contactor 40, and its end 11A is also bonded to the end of the reinforcing tube 90. The other structure is the same as that of FIG. The material of the reinforcing plate 11 is the same as that of the reinforcing cylinder 9 for the coil electrode 5
A material having higher resistance and higher mechanical strength, for example, austenitic stainless steel is used. As a result, the inclination of the contact 40 is suppressed, and most of the current flows to the coil electrode 5 side. The reinforcing plate 11 in FIG. 3 is formed in an oval shape, and the width of the narrow side is smaller than the opening diameter of the wide side of the reinforcing tube 90. The reinforcing plate 11 is joined by bending the reinforcing plate 11 slightly and inserting the reinforcing plate 11 into the reinforcing tube 90, arranging silver brazing metal on the entire surface thereof, and then placing the contactor 40 and heat-welding the whole. Are joined by.

[0015]

As described above, the present invention has a structure in which the braided reinforcing cylinder is joined to the coil electrode and the current-carrying shaft.
With this configuration, the deformation of the outer peripheral portion of the coil electrode is suppressed, and there is no possibility that the coil electrode and the contactor will contact each other at a portion other than the joint portion. Further, according to the present invention, in the above structure, the thicker opening of the reinforcing cylinder surrounds the entire outer circumference of the coil electrode and the end of the opening is rounded. With this structure, the withstand voltage between the contacts is improved and the insulation reliability is improved. Further, in the present invention, in addition to the above configuration, a reinforcing plate is arranged inside the reinforcing cylinder and joined to both the contactor and the reinforcing cylinder. With this configuration, the inclination of the contact is also suppressed,
There is provided an apparatus in which there is no possibility that the coil electrode and the contactor contact each other at a portion other than the joint portion, and an advantage that the rated breaking capacity of the vacuum valve can be further improved is obtained.

[Brief description of drawings]

FIG. 1 is a plan view of a contact of a vacuum valve according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB of FIG.

FIG. 3 is a cross-sectional view of essential parts showing the structure of a vacuum valve according to another embodiment of the present invention.

FIG. 4 is a sectional view showing a configuration example of a conventional vacuum valve.

5 is a plan view of the contact of FIG.

6 is a sectional view taken along line AA of FIG.

[Explanation of symbols]

 40 contactor 5 coil electrode 5A center part 5B arm part 5C orbiting part 5D joint part 5E joint surface 5F outer peripheral face 60 current-carrying shaft 9 reinforcing cylinder 90 reinforcing cylinder 10 void 11 reinforcing plate

Claims (3)

[Claims] 1. A contactor housed in a vacuum tank made of an insulating cylinder and facing each other so as to be able to come into contact with and separate from each other, and one end of each contactor is joined to the opposite side of the contactor and is joined to the contactor. The coil electrode that forms a magnetic field parallel to the arc that is generated at the end of the coil, and the other end of this coil electrode that is joined to the coil shaft and has a current-carrying shaft that is airtightly drawn to the outside of the vacuum tank. A reinforcing cylinder is provided, which is made of a metal rod cylinder having a different diameter and whose inner wall surface is joined to the outer peripheral portion of the coil electrode opposite to the contactor side, and the narrow opening of the reinforcing cylinder is joined to the current-carrying shaft. A vacuum valve characterized by that. 2. The structure according to claim 1, wherein the thicker opening of the reinforcing cylinder surrounds the entire outer circumference of the coil electrode with a gap, and the end of the opening is rounded. And vacuum valve. 3. The structure according to claim 2, wherein a metallic reinforcing plate is arranged inside the reinforcing cylinder, and the reinforcing plate is bonded to the opposite surface of the contact and to the reinforcing cylinder. Characteristic vacuum valve.