JP2010129337A - Vacuum valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum valve which uses a magnetic body which is easy to process and generates a stable magnetic field parallel in an axial direction. <P>SOLUTION: The vacuum valve includes a pair of freely attachable/removable contacts 3; a cup-like coil electrode 2, which generates a magnetic field parallel to an axial direction between the contacts 3, wherein two or more magnetic bodies 5 of a rod shape are arranged in a circumferential, direction with a predetermined spacing in a space portion of a coil electrode at the back surface of the contacts 3; an eddy current within magnetic body 5 is controlled; and a magnetic field parallel to an axial direction is increased. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vacuum valve having a pair of contact points that can increase and decrease a magnetic field parallel to an axial direction.

Conventionally, this type of vacuum valve is provided with a contact that can be freely contacted and separated and a coil electrode that generates a magnetic field parallel to the axial direction between the contacts, thereby improving the cutoff characteristics. Furthermore, it is known that a magnetic material is further increased by arranging a ring-shaped magnetic body in the coil electrode on the back surface of the contact. A magnetic field parallel to the axial direction diffuses the arc generated between the contacts, improving the breaking characteristics. (For example, refer to Patent Document 1).
JP-A-6-150786 (Page 3, FIG. 1)

  The above-described conventional vacuum valve has the following problems. In many cases, a ring-shaped magnetic body is obtained by cutting a thick rod-shaped material into a predetermined length and cutting the inner periphery and the outer periphery into a predetermined size. For this reason, a great deal of time is required for the processing operation, and the material of the inner peripheral portion is wasted.

  Further, in a ring-shaped magnetic body, when a coil electrode is energized to generate a magnetic field parallel to the axial direction, an electromotive force is generated in a direction that cancels the change of the magnetic field, and a circumferential eddy current flows. The eddy current acts to reduce a magnetic field parallel to the axial direction generated by the coil electrode.

  As a countermeasure against eddy currents, there is a method in which a part of the magnetic body in the circumferential direction is cut and released, but the residual stress inside the magnetic body is also released and deformation occurs. When the magnetic material is deformed, it becomes difficult to obtain a predetermined magnetic field, and advanced correction processing is required for correction processing.

  The present invention has been made to solve the above-described problems, and has an object to provide a vacuum valve that can facilitate the processing of a magnetic material, stabilize the generation of a magnetic field, and increase the magnetic field parallel to the axial direction. To do.

  In order to achieve the above object, a vacuum valve of the present invention is a vacuum valve comprising a pair of contactable and separable contacts and a coil electrode that generates a magnetic field parallel to the axial direction between the contacts, A plurality of rod-shaped magnetic bodies are arranged in the circumferential direction at predetermined intervals on the back surface of the contact.

  According to the present invention, since a plurality of rod-like magnetic bodies are arranged at predetermined intervals in the circumferential direction in the space of the coil electrode that generates a magnetic field parallel to the axial direction, the workability of the magnetic bodies is easy. In addition, the generation of eddy currents in the magnetic body is extremely small, and the magnetic field parallel to the axial direction can be increased.

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

  First, a vacuum valve according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a cross-sectional view showing a configuration of a contact of a vacuum valve according to Embodiment 1 of the present invention, and FIG. 2 is a view of the contact of the vacuum valve according to Embodiment 1 of the present invention as viewed from the contact side. In addition, it demonstrates using one contact among a pair of contacts.

  As shown in FIG. 1, an outer bottom portion of a cup-shaped coil electrode 2 made of electrolytic copper or the like is fixed to the end of the energizing shaft 1. A disk-shaped contact 3 made of a copper alloy is fixed to the opening of the coil electrode 2. A ring-shaped reinforcing member 4 made of, for example, stainless steel having a higher electric resistance than the coil electrode 2 or the contact 3 is fixed to the substantially central portion by brazing or the like in the space 2 a that is inside the coil electrode 2. Mechanical reinforcement is provided.

  A plurality of columnar magnetic bodies 5 are fixed between the bottom surface 2b of the space 2a of the coil electrode 2 and the contact 3 by brazing or the like. As shown in FIG. 2, the magnetic bodies 5 are arranged in the circumferential direction with a predetermined distance from each other, and at a predetermined distance from the inner peripheral side surface of the space 2 a and the outer peripheral side surface of the reinforcing member 4. Has been placed. As shown by a two-dot chain line in FIG. 1, a plurality of slits 6 that obliquely cross the axial direction are provided on the outer peripheral portion 2c of the coil electrode 2 so that a magnetic field parallel to the axial direction can be generated. ing.

  Thereby, even if a magnetic field change occurs in the coil electrode 2 in the individual magnetic bodies 5, the generation of eddy current is extremely small because it is not a ring shape as in the prior art but a small-diameter columnar shape. Further, since predetermined intervals are maintained between the magnetic bodies 5, between the magnetic body 5 and the inner peripheral side surface of the outer peripheral portion 2 c, and between the magnetic body 5 and the outer peripheral side surface of the reinforcing member 4, The magnetic field is stabilized. That is, since a stable magnetic field is applied by the magnetic body 5 over the entire circumferential direction of the contact 3, the magnetic field parallel to the axial direction can be increased.

  In addition, since the magnetic body 5 has only to cut a small-diameter rod-shaped material that can be arranged in the space portion 2a into a predetermined length and cut the outer periphery into a predetermined size, the waste of the material is reduced, Processing work becomes easy.

  According to the vacuum valve of the first embodiment, a plurality of columnar magnetic bodies 5 are arranged in the circumferential direction at predetermined intervals in the space 2a of the coil electrode 2 that is the back surface of the contact 3. Even if the magnetic field changes in the coil electrode 2, the generation of eddy currents in the magnetic body 5 is extremely small, and the magnetic field parallel to the axial direction generated in the coil electrode 2 can be increased.

  In the first embodiment, the magnetic body 5 has been described as a cylindrical shape. However, if the material is manufactured with a polygonal cross section or an elliptical cross section, the generation of eddy currents can be suppressed even if the material is maintained, and the shaft is maintained. The magnetic field parallel to the direction can be increased. Here, these shapes are simply defined as bar shapes.

  Next, a vacuum valve according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view illustrating the configuration of the contact of the vacuum valve according to the second embodiment of the present invention. The difference between the second embodiment and the first embodiment is the shape of the magnetic material. In FIG. 3, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 3, the end portion of the magnetic body 5 fixed to the bottom surface portion 2b of the coil electrode 2 is a hemispherical portion 5a. Moreover, it is good also as a cone-shaped part. That is, the magnetic body 5 is fixed in point contact with the bottom surface portion 2b.

  According to the vacuum valve of the second embodiment, in addition to the effects of the first embodiment, since the end of the magnetic body 5 fixed to the bottom surface 2b of the coil electrode 2 is fixed by point contact, the contact resistance increases. In addition, the current diverted to the magnetic body 5 can be suppressed, and the magnetic field of the magnetic body 5 can be stabilized.

  In the second embodiment, the magnetic body 5 in contact with the bottom surface portion 2b has been described as a point contact. However, by making at least one end including the contact 3 side a point contact, the current diverted to the magnetic body 5 is suppressed. be able to.

  Further, the magnetic body 5 has been described in a bare state where the material is exposed. However, if the surface of the magnetic body 5 is covered with an insulating material such as ceramics, the current diverted to the magnetic body 5 can be further suppressed. .

  Next, a vacuum valve according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view illustrating the configuration of the contact of the vacuum valve according to the third embodiment of the present invention. The third embodiment differs from the second embodiment in that the length of the magnetic material is shortened. In FIG. 4, the same components as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the length of the magnetic body 5 in the axial direction is made shorter than that of the second embodiment so that a predetermined gap is maintained from the bottom surface portion 2b. Further, the reinforcing member 4 is constituted by a body part 4a and a flange part 4b having an outer diameter larger than that of the body part 4a, and one end of the magnetic body 5 is attached to a plurality of mounting holes provided in a circumferential direction of the flange part 4b. It is fixed by brazing.

  According to the vacuum valve of the third embodiment, in addition to the effects of the second embodiment, since the magnetic body 5 is not in contact with the bottom surface portion 2b, the current diverted to the magnetic body 5 can be further suppressed. Further, since the contact 3 is supported and fixed by the flange 4b having a large area, deformation of the contact 3 can be suppressed.

  In the third embodiment, the flange 4b is disposed on the contact 3 side. However, a flange is also provided on the bottom surface 2b side of the coil electrode 2, and the magnetic body 5 is fixed to the flange 3 and the contact 3 side. May be non-contact.

Sectional drawing which shows the structure of the contact of the vacuum valve which concerns on Example 1 of this invention. The figure which looked at the contact of the vacuum valve which concerns on Example 1 of this invention from the contact side. Sectional drawing which shows the structure of the contact of the vacuum valve which concerns on Example 2 of this invention. Sectional drawing which shows the structure of the contact of the vacuum valve which concerns on Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Current supply shaft 2 Coil electrode 2a Space part 2b Bottom face part 2c Outer peripheral part 3 Contact point 4 Reinforcing member 4a Body part 4b Gutter part 5 Magnetic body 5a Hemisphere part 6 Slit

Claims (5)

A pair of detachable contacts;
A vacuum valve comprising a coil electrode that generates a magnetic field parallel to the axial direction between the contacts,
A vacuum valve characterized in that a plurality of rod-like magnetic bodies are arranged in the circumferential direction at predetermined intervals on the back surface of the contact.   The vacuum valve according to claim 1, wherein the magnetic body is provided between the contact and the bottom surface of the coil electrode, and at least one end is a point contact.   The vacuum valve according to claim 1, wherein the magnetic body is provided between the contact point and the bottom surface of the coil electrode, and at least one end thereof is not in contact.   4. The vacuum valve according to claim 3, wherein a reinforcing member having a flange on at least the contact side is provided between the contact and the bottom surface of the coil electrode, and the magnetic body is fixed to the flange. .   The vacuum valve according to claim 1, wherein the magnetic body is covered with an insulating material.

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