JP2011228083A - Vacuum valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the withstand voltage characteristics and the interruption characteristics by improving the magnetic field distribution between contacts.SOLUTION: In a vacuum valve having a pair of make/break contacts 6, the contact 6 comprises an electrode 10 fixed to the end of an energization shaft 7 and generating a magnetic field, an electrode plate 11 attached to the electrode 10, a first contact member 12 attached to the central part of the electrode plate 11 and made of an alloy improving the withstand voltage characteristics, a second contact member 13 attached to the circumference of the first contact member 12 and made of an alloy improving the interruption characteristics, and a magnetic body 14 provided between the electrode 10 and the electrode plate 11 and improving the magnetic field strength. The electrode plate 11 has a conductivity higher than those of the first contact member 12 and second contact member 13 so that temperature rise can be limited, and the magnetic body 14 is provided with a plurality of slits in the circumferential direction in order to limit generation of eddy current.

Description

  Embodiments of the present invention relate to a vacuum valve having a pair of contact points that can improve withstand voltage characteristics and cutoff characteristics.

  As shown in FIG. 5, the vacuum valve having a pair of contactable and separable contacts is sealed with a fixed sealing metal fitting 2 at one end of a cylindrical vacuum insulating container 1 and a movable sealing metal fitting 3 at the other end. Has been. A fixed-side energizing shaft 4 is fixed through the fixed-side sealing fitting 2, and a fixed-side contact 5 is fixed to an end in the vacuum insulating container 1. A movable side contact 6 that can be contacted and separated so as to face the fixed side contact 5 is fixed to the end of the movable side energizing shaft 7 that movably penetrates the movable side sealing fitting 3. One end of a telescopic bellows 8 is sealed to the middle portion of the movable side energizing shaft 7 and the other end is sealed to the movable side sealing fitting 3. Thereby, the movable side energizing shaft 7 can be moved in the axial direction while maintaining the vacuum in the vacuum insulating container 1. In addition, a cylindrical arc shield 9 that surrounds the contacts 5 and 6 is fixed to the vacuum insulating container 1 to prevent metal vapor from adhering to the inner surface of the vacuum insulating container 1.

  Here, conventionally, in order to improve the breaking characteristics, a so-called longitudinal magnetic field electrode that generates a magnetic field parallel to the axial direction between the contacts 5 and 6 is used, and a magnetic material is further provided on the longitudinal magnetic field electrode to improve the magnetic field distribution. (For example, refer to Patent Document 1).

  Furthermore, in order to improve the withstand voltage characteristics required for vacuum valves, it is known to use a contact made of two types of contact materials for withstand voltage characteristics and interrupt characteristics to improve the withstand voltage characteristics as well as the interrupt characteristics. (For example, see Patent Document 2).

JP 2000-76964 A JP 2003-331699 A

The above-described conventional vacuum valve has the following problems.
Since vacuum valves have been increased in capacity and voltage, it is necessary to improve the breakdown characteristics as well as the withstand voltage characteristics. That is, it is desired to use two types of contact materials for the breaking characteristics and the withstand voltage characteristics, improve the magnetic field distribution and uniformly diffuse the arc, and improve the breaking characteristics as well as the withstand voltage characteristics.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a vacuum valve that can improve the withstand voltage characteristics, improve the magnetic field distribution, and improve the cutoff characteristics.

  In order to achieve the above object, a vacuum valve according to the present invention is a vacuum valve having a pair of contactable and separable contacts, wherein the contact is an electrode for generating a magnetic field fixed to a current-carrying shaft end, and the electrode An electrode plate fixed to the electrode plate, a first contact member made of a withstand voltage characteristic improving alloy fixed to the center portion of the electrode plate, and an interruption characteristic improving alloy fixed to the outer periphery of the first contact member. A second contact member; and a magnetic body provided between the electrode and the electrode plate, wherein the electrode plate has higher conductivity than the first contact member and the second contact member, The magnetic body is provided with a plurality of slits in the circumferential direction.

Sectional drawing which shows the contact used for the vacuum valve which concerns on Example 1 of this invention. The top view which shows the magnetic body used for the vacuum valve which concerns on Example 1 of this invention. The top view which shows the longitudinal magnetic field electrode used for the vacuum valve which concerns on Example 1 of this invention. Sectional drawing which shows the contact used for the vacuum valve which concerns on Example 2 of this invention. Sectional drawing which shows the structure of the vacuum valve of a prior art.

  In this embodiment, two types of contact materials are used, and the magnetic field distribution for diffusing the arc is improved. 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 contact used in a vacuum valve according to Embodiment 1 of the present invention, FIG. 2 is a top view showing a magnetic body used in the vacuum valve according to Embodiment 1 of the present invention, and FIG. It is a top view which shows the longitudinal magnetic field electrode used for the vacuum valve which concerns on Example 1 of invention. In addition, in each figure, the same code | symbol was attached | subjected about the component similar to the past. Further, the configuration of the vacuum valve is the same as that of the conventional method, so that the description thereof is omitted. Further, since the contacts on the fixed side and the movable side are the same, the description will be made using the movable side.

  As shown in FIG. 1, a longitudinal magnetic field electrode 10 is fixed to the end of the movable energizing shaft 7 by brazing or the like. As shown in FIG. 2, the longitudinal magnetic field electrode 10 includes an arm portion 10 a fixed to the movable side energizing shaft 7 and extending in the radial direction, and an arc shape that is connected to the end of the arm portion 10 a and generates a magnetic field parallel to the axial direction. The coil part 10b and the connection part 10c connected to the coil part 10b end are comprised. A plurality of these arm portions 10a, coil portions 10b, and connection portions 10c are provided in the circumferential direction.

  One surface of an electrode plate 11 made of, for example, electrolytic copper, which has better conductivity than a contact member described later, is fixed to the coil portion 10c by brazing or the like. A cylindrical first contact member 12 is fixed to the other surface of the electrode plate 11 at the center, and an annular second contact member 13 is fixed to the outer periphery thereof by brazing or the like. The first contact member 12 protrudes toward the fixed side from the second contact member 13.

  As the first contact member 12, a Cu-W alloy having an excellent withstand voltage characteristic and having a W content of 70 to 80 wt% or an Ag-WC alloy having an Ag content of 35 to 45 wt% that suppresses the arc voltage is used. . The second contact member 13 is made of a Cu—Cr alloy having a Cr content of 10 to 30 wt% and excellent in arc resistance. The first contact member 12 contains at least one of Bi, Te, Se, and Sb, and the second contact member 13 contains at least one of Ti, Zr, V, Nb, Ta, and Mo. By making it, each characteristic can be improved.

  As shown in FIG. 3, a high magnetic permeability annular magnetic body 14 such as pure iron is provided between the electrode plate 11 and the longitudinal magnetic field electrode 10 and is fixed to the electrode plate 11 side. The magnetic body 14 is provided with a plurality of slits 14a in the circumferential direction. Moreover, the notch part 14b which the contact part 11c penetrates is provided so that it may not contact the contact part 11c. The inner diameter is slightly larger than the outer diameter of the movable energizing shaft 7 so as not to come into contact with it, and the outer diameter is about the same as that of the electrode plate 11.

  As described above, the movable contact 6 includes the longitudinal magnetic field electrode 10, the electrode plate 11, the first contact member 12, and the second contact member 13. The same applies to the stationary contact.

  As a result, a magnetic field parallel to the axial direction is generated by the longitudinal magnetic field electrode 10 when a large current is interrupted, but the magnetic field is attracted toward the outer periphery by the magnetic body 14. That is, the magnetic field distribution is stronger on the second contact member 13 than on the first contact member 12, and the arc can be diffused in the outer circumferential direction. Since the diffused arc is an alloy in which the second contact member 13 is excellent in arc resistance, the interruption characteristic can be improved. That is, the arc diffusion by the magnetic body 14 and the arc extinguishing by the second contact member 13 are synergistic, and the interruption characteristic can be improved.

  Further, in the magnetic body 14, the eddy current generated in the alternating magnetic field is suppressed by the slit 14a and is not in contact with the movable side energizing shaft 7 or the contact portion 10c, so that no shunting occurs and a stronger magnetic field is generated. Can do. In the first contact member 12, the gap length is the narrowest and becomes the starting point of discharge, but withstand voltage characteristics can be improved by an excellent alloy.

  Here, the Cu-W alloy mainly improves the static withstand voltage characteristic, and the Ag-WC alloy mainly improves the re-ignition characteristic. Since these all suppress discharge, they are defined as alloys with improved withstand voltage characteristics. Further, the second contact member 13 is defined as an interruption characteristic improving alloy.

  Moreover, since the 1st contact member 12 and the 2nd contact member 13 are each adhere | attached on the electrode plate 11 with sufficient electroconductivity, a temperature rise can be suppressed low and it can improve an electricity supply characteristic.

  According to the vacuum valve of the first embodiment, the electrode plate 11 is fixed to the longitudinal magnetic field electrode 10 through the magnetic body 14 provided with the slits 14a, and the first with excellent withstand voltage characteristics is provided at the center of the electrode plate 11. Since the contact member 12 and the second contact member 13 having excellent blocking characteristics are provided on the outer periphery thereof, the magnetic field strength is enhanced by the magnetic body 14 that suppresses the eddy current, the magnetic field distribution is improved, and withstand voltage characteristics, The blocking characteristic can be improved.

  Next, a vacuum valve according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a contact used in a vacuum valve according to Embodiment 2 of the present invention. The second embodiment differs from the first embodiment in the electrodes that generate a magnetic field. In FIG. 4, 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. 4, a so-called control electrode 15 having a cup shape is fixed to the end of the movable energizing shaft 7. The outer peripheral surface is provided with a plurality of slits 15a that obliquely cross the axial direction. The slit 15a end and the electrode plate 11 are connected by a plurality of connecting portions 15b. A magnetic body 14 is provided between the electrode plate 11 and the control electrode 15.

  According to the vacuum valve of the second embodiment, the same effect as that of the first embodiment can be obtained also in the control electrode 15 that generates a magnetic field radially from the axis and rotationally drives the arc in the circumferential direction.

DESCRIPTION OF SYMBOLS 1 Vacuum insulating container 2 Fixed side sealing metal fitting 3 Movable side sealing metal fitting 4 Fixed side energizing shaft 5 Fixed side contact 6 Movable side contact 7 Movable side energizing shaft 8 Bellows 9 Arc shield 10 Vertical magnetic field electrode 10a Arm part 10b Coil part 10c , 15b Connecting portion 11 Electrode plate 12 First contact member 13 Second contact member 14 Magnetic body 14a, 15a Slit 14b Notch 15 Control electrode

Claims (4)

A vacuum valve having a pair of contactable and separable contacts,
The contact is an electrode that generates a magnetic field fixed to the end of the energizing shaft;
An electrode plate fixed to the electrode;
A first contact member made of a withstand voltage characteristic improving alloy fixed to a central portion of the electrode plate;
A second contact member made of a barrier property improving alloy fixed to the outer periphery of the first contact member;
A magnetic body provided between the electrode and the electrode plate;
The electrode plate has higher electrical conductivity than the first contact member and the second contact member,
A vacuum valve characterized in that the magnetic body is provided with a plurality of slits in the circumferential direction.   The vacuum valve according to claim 1, wherein the electrode is a longitudinal magnetic field electrode.   The vacuum valve according to claim 1, wherein the electrode is a control electrode. The withstand voltage characteristic improving alloy is one of a Cu-W alloy and an Ag-WC alloy,
The vacuum valve according to any one of claims 1 to 3, wherein the barrier property improving alloy is a Cu-Cr alloy.

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