JP2006344557A - Vacuum valve and conditioning treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve withstand voltage property by efficiently performing conditioning treatment. <P>SOLUTION: This vacuum valve comprises a vacuum insulated container 1, a fixed side sealing fitting 2 sealed to one side of the vacuum insulated container 1; a fixed side current-carrying shaft 4 fixed penetrating the fixed side sealing fitting 2; a fixed side contact 5 and a movable side contact 6 freely contacting and separating; a fixed side electrode protective shield 10 provided to surround the fixed side contact 5; a movable side sealing fitting 3 sealed to the other side of the vacuum insulated container 1; a movable side current-carrying shaft 7 penetrating the movable side sealing fitting 3; a main bellows 8 mounted between the movable side current-carrying shaft 7 and movable side sealing fitting 3; and a movable side electrode protective shield 11 provided to surround the movable contact 6. An extensible outer bellows 20 is mounted between one side of the vacuum insulated container 1 and the fixed side sealing fitting 2 and/or between the other side of the vacuum insulated container 1 and the movable side sealing fitting 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vacuum valve and a conditioning processing method that can efficiently perform a conditioning process for removing electrical defects that occur during manufacturing and improve a withstand voltage characteristic.

  In FIG. 7 showing a cross-sectional view of a typical conventional vacuum valve, a fixed-side sealing fitting 2 and a movable-side sealing fitting 3 are airtightly attached to both end opening surfaces of a cylindrical vacuum insulating container 1. Yes. A fixed-side energizing shaft 4 serving as one electric circuit is hermetically penetrated and fixed to the fixed-side sealing metal fitting 2, and a fixed-side contact 5 is fixed to the end of the fixed-side energizing shaft 4 in the vacuum insulating container 1. Opposite to the fixed side contact 5, a movable side contact 6 that is detachable is fixed to the end of the movable side energizing shaft 7 serving as the other electric circuit.

One end of the telescopic main bellows 8 is airtightly attached to the middle portion of the movable side energizing shaft 7 in the vacuum insulating container 1, and the other end is airtightly attached to the central opening of the movable side sealing fitting 3. ing. Thereby, it is possible to move the movable-side energizing shaft 7 in the axial direction while maintaining a vacuum degree of an internal pressure of 10 ⁻² Pa or less.

  In addition, a cylindrical arc shield 9 is provided on the middle protruding portion 1a of the inner surface of the vacuum insulating container 1 so as to surround both the contacts 5 and 6, and the metal vapor generated when the contacts 5 and 6 are opened and closed. It adheres to the inner surface of the vacuum insulating container 1 and prevents the creeping insulation resistance from decreasing (see, for example, Patent Document 1).

  When such a vacuum valve is used for a disconnector, it is necessary to open and close a loop current (several hundred amperes), and the surfaces of both contacts 5 and 6 are melted. Moreover, when using for earthing switches, the duty which forcibly short-circuits an accident electric current (several thousands to several tens of thousands of amperes) is required, and the surfaces of both the contacts 5 and 6 are melted or welded.

  As described above, the gap length between the contacts 5 and 6 is generally increased in order to ensure a predetermined withstand voltage characteristic even when both the contacts 5 and 6 are melted or welded and the surface becomes rough. Increasing the gap length increases the axial direction of the vacuum valve, and as a result, the overall shape of the disconnector and grounding switch is increased.

  As a method for solving this problem, a method in which an electrode protection shield that surrounds the contacts 5 and 6 is attached is known (for example, see Patent Document 2).

  In FIG. 8 showing a sectional view of this vacuum valve, the stationary contact 5 is surrounded by a cylindrical stationary electrode protection shield 10 fixed to the stationary sealing metal fitting 2. The movable contact 6 is surrounded by a cylindrical movable electrode protection shield 11 fixed to the movable sealing fitting 3. And the gap length between the front-end | tips which the electrode protection shields 10 and 11 oppose is shortened rather than the gap length at the time of the contact 5 and 6 opening.

  As a result, even if the surfaces of both contacts 5 and 6 are roughened due to current switching, they are surrounded by the electrode protection shields 10 and 11, so that the electric field is mitigated and the axial length can be shortened. .

  On the other hand, in the manufacturing process of the vacuum valve as shown in FIG. 8, the contacts 5 and 6 are subjected to a conditioning process for removing electrical defects such as fine protrusions and burrs generated by machining or the like by electrical processing. . In the conditioning process between the contacts 5 and 6, the gap length is shortened and a low voltage is applied for discharging to remove electrical defects. However, a high voltage must be applied between the electrode protection shields 10 and 11.

For this reason, the test equipment for performing the conditioning process has to have a large capacity in order to generate a voltage higher than the withstand voltage of the vacuum valve. Furthermore, the discharge generated between the electrode protection shields 10 and 11 may move to the inner surface of the vacuum insulating container 1. When the discharge is transferred to the inner surface of the vacuum insulating container 1, the creeping surface is soiled or damaged.
JP 2000-294089 A (2nd page, FIG. 5) JP-A-53-3662 (2nd page, Fig. 1)

  If the vacuum valve using the arc shield 9 is used for a disconnector or a ground switch, the gap length between the contacts 5 and 6 must be increased, so that the axial direction becomes longer.

  Further, in the case of using the electrode protection shields 10 and 11 surrounding the contacts 5 and 6, respectively, the test equipment during the conditioning process has a large capacity, and the vacuum insulating container 1 may be soiled and damaged. When damaged, the degree of vacuum in the vacuum insulating container 1 cannot be maintained.

  For this reason, the vacuum valve which improved the withstand voltage characteristic using the electrode protection shields 10 and 11, and can perform a conditioning process efficiently was desired.

  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 efficiently perform a conditioning process and improve a withstand voltage characteristic.

  In order to achieve the above object, a vacuum valve according to the present invention includes a cylindrical vacuum insulating container, a fixed-side sealing metal fitting attached to one opening surface of the vacuum insulating container, and a through-hole to the fixed-side sealing metal fitting. The fixed-side energizing shaft is fixed, the fixed-side contact fixed to the end of the fixed-side energizing shaft in the vacuum insulating container, and the fixed-side sealing bracket is provided so as to surround the fixed-side contact. A fixed electrode protection shield that is fixed, a movable sealing member that is attached to the other opening surface of the vacuum insulating container, and a movable energizing shaft that movably passes through the central opening of the movable sealing member. A movable side contact fixed to the end of the movable side energizing shaft so as to face the fixed side contact; one end of the movable side energizing shaft is attached to the center side opening of the movable side sealing metal fitting Mounted telescopic main bellows A vacuum valve provided so as to surround the movable side contact and having a movable side electrode protection shield fixed to the movable side sealing metal fitting, wherein one of the opening surfaces of the vacuum insulating container and the vacuum valve A stretchable external bellows is attached between the fixed-side sealing fittings and between at least one of the other opening surface of the vacuum insulating container and the movable-side sealing fittings.

  According to the present invention, the pair of contacts are respectively surrounded by the electrode protection shield, and the conditioning process at the time of manufacturing is performed by individually reducing the gap length between the contacts and between the electrode protection shields, so the conditioning process is efficient. And withstand voltage characteristics can be improved.

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

  First, a vacuum valve according to a first embodiment of the present invention will be described with reference to FIGS. 1 is a cross-sectional view showing a configuration of a vacuum valve according to Embodiment 1 of the present invention, FIG. 2 is a diagram for explaining a conditioning processing method between contacts of the vacuum valve according to Embodiment 1 of the present invention, and FIG. FIG. 3 is a diagram for explaining a conditioning method between electrode protection shields of a vacuum valve according to Embodiment 1 of the present invention. In addition, in each figure, the same code | symbol was attached | subjected about the component similar to the past.

  As shown in FIG. 1, a fixed-side sealing fitting 2 is airtightly attached to one opening surface of a cylindrical vacuum insulating container 1 made of alumina porcelain, for example. One end of a telescopic outer bellows 20 is airtightly attached to the other opening surface. At the other end of the external bellows 20, the movable-side sealing fitting 3 is airtightly attached.

  A fixed-side energizing shaft 4 serving as one electric circuit is hermetically penetrated and fixed to the fixed-side sealing metal fitting 2, and a fixed-side contact 5 is fixed to the end of the fixed-side energizing shaft 4 in the vacuum insulating container 1. Opposite to the fixed side contact 5, a movable side contact 6 that is detachable is fixed to the end of the movable side energizing shaft 7 serving as the other electric circuit.

One end of the telescopic main bellows 8 is airtightly attached to the middle portion of the movable side energizing shaft 7 in the vacuum insulating container 1, and the other end is airtightly attached to the central opening of the movable side sealing fitting 3. ing. Thereby, it is possible to move the movable-side energizing shaft 7 in the axial direction while maintaining a vacuum degree of an internal pressure of 10 ⁻² Pa or less.

  The fixed side contact 5 is surrounded by a metal cylindrical fixed side electrode protection shield 10 whose one end is fixed to the fixed side metal fitting 2. The movable side contact 6 is surrounded by a metallic cylindrical movable side electrode protection shield 11 whose one end is fixed to the movable side sealing fitting 3. The tips of these electrode protection shields 10 and 11 are each curved in an arc shape, and the gap length between the tips is shorter than the gap length when the contacts 5 and 6 are opened.

  Thereby, even if the surface of both the contacts 5 and 6 is roughened due to current switching, both the contacts 5 and 6 are surrounded by the respective electrode protection shields 10 and 11, so that the electric field is reduced and the withstand voltage characteristics are improved. The decrease can be suppressed.

  Next, a conditioning method for removing electrical defects in the manufacture of such a vacuum valve will be described with reference to FIGS.

  As shown in FIG. 2, between the contacts 5 and 6, the main bellows 8 is extended to move the movable-side energizing shaft 7 upward in the drawing to shorten the gap length. And a voltage is applied between the contacts 5 and 6, and it discharges. In this case, the external bellows 20 is in an extended state.

  As shown in FIG. 3, between the electrode protection shields 10 and 11, the external bellows 20 is shortened to shorten the gap length between the tips while the contact points 5 and 6 are opened at the open position. And a voltage is applied between the electrode protection shields 10 and 11, and it discharges. When the conditioning process between the electrode protection shields 10 and 11 is completed, the external bellows 20 is extended and returned to the original state, and is incorporated into a switch or the like.

  As a result, the voltage in the conditioning process between the contacts 5 and 6 and between the electrode protection shields 10 and 11 can be kept low. For this reason, the capacity | capacitance of a test equipment can be made small and it can suppress that the discharge between the electrode protection shields 10 and 11 transfers to the vacuum insulation container 1 inner surface.

  According to the vacuum valve of the first embodiment, the pair of contacts 5 and 6 are surrounded by the electrode protection shields 10 and 11, respectively, and during the conditioning process at the time of manufacture, between the contacts 5 and 6 and between the electrode protection shields 10 and 11. Since the gap length is individually shortened, the conditioning process is efficient, and the electric field relaxation of the contacts 5 and 6 is achieved by the electrode protection shields 10 and 11, and the withstand voltage characteristics can be improved.

  In the first embodiment, the external bellows 20 is provided between one opening surface of the movable-side sealing fitting 3 and the vacuum insulating container 1, but the other opening surface of the fixed-side sealing fitting 2 and the vacuum insulating container 1 is described. Even if external shields 20 are provided between the fixed side sealing metal fitting 2 and the movable side sealing metal fitting 3, the gap length between the electrode protection shields 10 and 11 can be shortened during the conditioning process.

  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 illustrating the configuration of the vacuum valve according to the second embodiment of the present invention. The second embodiment differs from the first embodiment in that an internal bellows is provided on the fixed energizing shaft side. 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 central opening is provided in the fixed-side sealing metal fitting 2 so that the fixed-side energizing shaft 4 penetrates freely. In addition, one end of the extendable internal bellows 21 is airtightly attached to the middle portion of the fixed-side energizing shaft 4, and the other end is airtightly attached to the central opening of the fixed-side sealing fitting 2.

  In the conditioning process, the fixed energizing shaft 4 and the movable energizing shaft 7 are moved to shorten the gap length between the contacts 5 and 6. Thereby, each contact 5 and 6 can be exposed rather than the front-end | tip of each electrode protection shield 10 and 11, and the conditioning process of the contacts 5 and 6 can be performed efficiently. That is, it is possible to perform the conditioning process on the side surface as well as the facing surface between the contacts 5 and 6.

  According to the vacuum valve of the second embodiment, in addition to the effects of the first embodiment, the conditioning process can be performed more efficiently.

  Next, a vacuum valve according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view illustrating the configuration of the vacuum valve according to the third embodiment of the present invention. The third embodiment differs from the first embodiment in that a first auxiliary shield that covers the external bellows is provided. In FIG. 5, 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. 5, an annular first auxiliary shield 22 protruding inward is airtightly attached to the end of the vacuum insulating container 1 to which the external shield 20 is attached. The end of the first auxiliary shield 22 is bent so as to cover the outer shield 20.

  According to the vacuum valve of the third embodiment, in addition to the effect of the first embodiment, it is possible to suppress the arrival of the metal vapor generated from between the contacts 5 and 6 when the current is opened and closed to the external bellows 20.

  Next, a vacuum valve according to Embodiment 4 of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view showing a configuration of a vacuum valve according to Embodiment 4 of the present invention. The fourth embodiment differs from the first embodiment in that a second auxiliary shield is provided on the movable side electrode protection shield. In FIG. 6, 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. 6, an annular second auxiliary shield 23 that extends in the radial direction is attached to the outer periphery of the movable electrode protection shield 11. Note that when the external bellows 20 is attached to the fixed-side sealing metal fitting 2 side, the second auxiliary shield 23 is attached to the fixed-side electrode protection shield 10.

  According to the vacuum valve of the fourth embodiment, in addition to the effect of the first embodiment, it is possible to suppress the arrival of the metal vapor generated from between the contacts 5 and 6 when the current is opened and closed to the external bellows 20.

Sectional drawing which shows the structure of the vacuum valve which concerns on Example 1 of this invention. The figure explaining the conditioning processing method between the contacts of the vacuum valve which concerns on Example 1 of this invention. The figure explaining the conditioning process method between the electrode protection shields of the vacuum valve which concerns on Example 1 of this invention. Sectional drawing which shows the structure of the vacuum valve which concerns on Example 2 of this invention. Sectional drawing which shows the structure of the vacuum valve which concerns on Example 3 of this invention. Sectional drawing which shows the structure of the vacuum valve which concerns on Example 4 of this invention. Sectional drawing which shows the structure of the vacuum valve which has the conventional arc shield. Sectional drawing which shows the structure of the vacuum valve which has the conventional electrode protection shield.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum insulating container 1a Protrusion part 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 Main bellows 9 Arc shield 10 Fixed side electrode protection shield 11 Movable electrode protection shield 20 External bellows 21 Internal bellows 22 First auxiliary shield 23 Second auxiliary shield

Claims (6)

A tubular vacuum insulated container;
A fixed-side sealing fitting attached to one opening surface of the vacuum insulating container;
A fixed-side energizing shaft that is fixedly penetrated to the fixed-side sealing fitting;
A fixed-side contact fixed in the vacuum insulating container of the fixed-side energizing shaft end;
A fixed-side electrode protection shield that is provided so as to surround the fixed-side contact, and is fixed to the fixed-side sealing metal fitting;
A movable-side sealing fitting attached to the other opening surface of the vacuum insulating container;
A movable-side energizing shaft that movably passes through a central opening of the movable-side sealing fitting;
A movable contact that is fixed to the movable energized shaft end opposite to the fixed contact;
A telescopic main bellows having one end attached to the movable-side energizing shaft and the other end attached to a central opening of the movable-side sealing fitting;
A vacuum valve provided so as to surround the movable side contact and having a movable side electrode protection shield fixed to the movable side sealing metal fitting,
A telescopic external bellows is attached between at least one of the opening surface of the vacuum insulating container and the fixed-side sealing fitting, and at least one of the other opening surface of the vacuum insulating container and the movable-side sealing fitting. Features a vacuum valve.   A central opening is provided in the fixed-side sealing metal fitting, the fixed-side energizing shaft is movably penetrated through the central opening, and an extendable internal bellows is attached between the central opening and the fixed-side energizing shaft. The vacuum valve according to claim 1.   The vacuum valve according to claim 1 or 2, wherein an auxiliary shield is provided at an end of the vacuum insulating container so as to cover the external bellows.   The vacuum valve according to claim 1, wherein an auxiliary shield extending in a radial direction is provided on an outer periphery of the electrode protection shield. A tubular vacuum insulated container;
A telescopic external bellows attached to at least one opening surface of the vacuum insulating container;
A pair of contacts housed in the vacuum insulation container;
A bellows that allows the contact points to contact and separate in an airtight manner; and
One electrode protection shield is provided so as to surround one of the contacts, and is fixed to one of the vacuum insulating containers;
A vacuum valve provided so as to surround the other of the contacts, and having the other electrode protection shield fixed to the other of the vacuum insulating container,
First, the bellows is expanded and contracted so that the gap between the contacts is shorter than the gap length between the electrode protection shields, and discharged.
Then, the external bellows is expanded and contracted to discharge the electrode protection shield with a gap shorter than the gap length between the contacts. 6. The bellows is attached between at least one of the contact and one opening surface of the vacuum insulating container, and at least one between the other contact and the other opening surface of the vacuum insulating container. Conditioning processing method of the vacuum valve as described in 2.

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