JP5197065B2 - Vacuum valve - Google Patents

Description

  The present invention relates to a vacuum valve in which a pair of contactable and separable contacts are housed in a vacuum vessel and an insulating layer is formed by molding an epoxy resin on the outer periphery thereof.

  Conventionally, a vacuum valve having a pair of contactable and separable contacts is molded with epoxy resin and a grounding layer is provided on the outer periphery of the insulating layer. Thereby, the vacuum valve can be reduced in size due to excellent insulating properties of the epoxy resin, and the installation environment can be selected by the ground layer (see, for example, Patent Document 1).

  In such a molded vacuum valve, as shown in FIG. 5, a fixed-side sealing fitting 2 and a movable-side sealing fitting 3 are sealed at both end openings of a cylindrical vacuum insulating container 1. A fixed-side energizing shaft 4 is fixed through the fixed-side sealing metal fitting 2, and a fixed-side contact 5 is fixed to the end. A movable contact 6 that can be moved toward and away from the fixed contact 5 is fixed to the end of the movable energizing shaft 7 that movably penetrates the movable seal 3. One end of the bellows 8 is sealed to the intermediate portion of the movable side energizing shaft 7 and the other end is sealed to the movable side sealing metal fitting 3. A cylindrical arc shield 9 that surrounds the contacts 5 and 6 and captures the metal vapor is fixed to the inner surface of the intermediate portion of the vacuum insulating container 1.

A fixed-side outer shield 10 and a movable-side outer shield 11 are fixed to the fixed-side sealing metal fitting 2 and the movable-side sealing metal fitting 3 on the outer periphery of both ends of the vacuum insulating container 1, respectively. An insulating layer 12 formed by molding an epoxy resin is provided on the outer periphery of these, and a ground layer 13 is provided on the outer periphery of the insulating layer 12.
JP 2002-152930 A (Page 9, FIG. 1)

  The above-described conventional vacuum valve has the following problems. When the potentials of the contacts 5 and 6 are 100%, it is desirable that the potential of the arc shield 9 is in the vicinity of 50%, which is intermediate between the potential of the ground layer 13 and 0%. However, the electric potential of the arc shield 9 is determined by the capacitance ratio between the contacts 5 and 6 and the arc shield 9 and between the arc shield 9 and the ground layer 13 and is swung to the ground side. In particular, since the insulating layer 13 is as large as 4 to 6 compared to the relative dielectric constant in vacuum, the potential is greatly swung to the ground side.

  If the electric potential of the arc shield 9 is swung to the ground side, the electric potential distribution in the vacuum insulating container 1 is disturbed, and the withstand voltage characteristic and the interruption characteristic are deteriorated. For this reason, when the arc shield 9 is used, the potential is surely fixed, and when the arc shield 9 is not used, it has been desired that metal vapor diffused from the contacts 5 and 6 can be captured. Even when one of the contacts 5 (6) has a potential of 100% and the other contact 6 (5) has a potential of 0%, the potential of the arc shield 9 is swung to the ground side.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a molded vacuum valve capable of maintaining a good potential distribution in a vacuum insulating container and improving a withstand voltage characteristic and a cutoff characteristic. .

In order to achieve the above object, a vacuum valve of the present invention comprises a cylindrical vacuum insulating container, a cup-shaped vacuum metal container having a peripheral edge sealed at one end opening of the vacuum insulating container, and the vacuum A fixed energizing shaft that is fixed to the bottom of the metal container, a fixed contact that is fixed to the end of the fixed energizing shaft, and a movable side sealing bracket that is sealed to the other end opening of the vacuum insulating container; A movable-side energizing shaft that movably penetrates the movable-side sealing fitting, a movable-side contact that is fixed to the movable-side energizing shaft end, and that is in contact with and away from the fixed-side contact; and A telescopic bellows whose one end is sealed to the intermediate portion and whose other end is sealed to the movable-side sealing fitting, and an insulating layer provided on the outer periphery of the vacuum metal container and the vacuum insulating container, , and a ground layer provided on an outer periphery of said insulating layer, said Allowed Wherein with increasing the outer diameter of the fixed contact than the side contact, fitted with a coil electrode for generating a vertical magnetic field to these contacts, and that increasing the outer diameter of the coil electrode of the fixed side of the movable And

  According to the present invention, a vacuum metal container is sealed at one end opening of the vacuum insulating container, and a pair of contacts that can be contacted and separated are accommodated in the vacuum metal container, and the contact on the fixed side and the vacuum metal container are Since they have the same potential, the potential distribution in the vacuum metal container and the vacuum insulation container is stabilized, and the withstand voltage characteristic and the cutoff characteristic can be 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 FIG. FIG. 1 is a cross-sectional view illustrating a configuration of a vacuum valve according to Embodiment 1 of the present invention. In FIG. 1, the same components as those in the prior art are denoted by the same reference numerals.

  As shown in FIG. 1, at one end opening of a cylindrical vacuum insulating container 1 made of an insulating material such as alumina porcelain, a peripheral portion of a cup-shaped vacuum metal container 20 made of a metal material such as stainless steel, for example. Is sealed. The fixed-side energizing shaft 4 is fixed through the bottom of the vacuum metal container 20, and the fixed-side contact 5 is fixed to the end of the vacuum metal container 20.

  A movable side contact 6, which is movable toward and away from the fixed side contact 5, movably penetrates the central opening of the movable side sealing fitting 3 sealed at the other end opening of the vacuum insulating container 1. It is fixed to the end of the energizing shaft 7. Here, the fixed side contact 5 can have an outer diameter larger than that of the movable side contact 6. One end of a telescopic bellows 8 is sealed at the intermediate portion of the movable side energizing shaft 7, and the other end is sealed at the central opening of the movable side sealing fitting 3.

  As a result, while maintaining the vacuum in the vacuum metal container 20 and the vacuum insulating container 1, the movable side energizing shaft 7 can be moved in the axial direction, and the fixed side contact 5 and the movable side contact 6 can be brought into and out of contact with each other. Further, a cylindrical arc shield 9 surrounding the contacts 5 and 6 is fixed to the inner surface of the vacuum metal container 20, and captures the metal vapor generated between the contacts 5 and 6 when the current is interrupted. .

  An annular stationary outer shield 10 and a movable outer shield 11 are fixed to the ends of the vacuum metal container 20 and the movable sealing metal fitting 3 on the outer periphery of both ends of the vacuum insulating container 1, respectively. An insulating layer 12 formed by molding an epoxy resin is provided on the outer periphery of the vacuum metal container 20, the vacuum insulating container 1, the fixed side outer shield 10 and the movable side outer shield 11. On the outer periphery of the insulating layer 12, for example, a ground layer 13 formed by applying a conductive paint is provided.

  Thereby, since the arc shield 9 is fixed at the same potential as the fixed side contact 5 and the vacuum metal container 20, it is possible to prevent the potential distribution from being disturbed due to potential imbalance. Since the electric potential of the arc shield 9 is fixed regardless of whether the contacts 5 and 6 are opened or closed, the electric potential distribution in the vacuum metal container 20 and the vacuum insulating container 1 is not disturbed, and the withstand voltage characteristic and the interruption characteristic are improved. Can be improved.

  Moreover, since the outer diameter of the stationary contact 5 can be made larger than that of the movable contact 6, temperature rise can be suppressed on the stationary side. Furthermore, when a coil electrode that controls a magnetic field, such as a longitudinal magnetic field electrode, is used, the outer diameter of the coil electrode can be increased, so that a larger magnetic field can be generated.

  According to the vacuum valve of the first embodiment, the vacuum metal container 20 is sealed at one end opening of the vacuum insulating container 1, the pair of contacts 5 and 6 are accommodated in the vacuum metal container 20, and the vacuum metal Since the container 20, the fixed contact 5, and the arc shield 9 are set to the same potential, the potential of the arc shield 9 is fixed, the potential distribution in the vacuum metal container 20 and the vacuum insulating container 1 is stabilized, and the withstand voltage characteristics and interruption are interrupted. Characteristics can be improved.

  Next, a vacuum valve according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 2 is a cross-sectional view showing a configuration of a vacuum valve according to Embodiment 2 of the present invention. The difference between the second embodiment and the first embodiment is that the outer diameter of the vacuum metal container is increased and the arc shield is removed. In FIG. 2, 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. 2, the outer diameter of the vacuum metal container 20 is set to the same size as the fixed-side outer shield 10. That is, the outer diameter of the vacuum metal container 20 is made larger than that of the vacuum insulating container 1. Further, an annular fixed inner shield 21 is provided at the end in the vacuum metal container 20.

  Thereby, the outer diameter of the vacuum metal container 20 can be enlarged, and the electric field strength of the stationary contact 5 and the movable contact 6 can be reduced. Further, since the vacuum insulating container 1 is surrounded by the fixed-side outer shield 10 and the fixed-side inner shield 21, the electric field at the end can be reduced. Furthermore, since the tip of the fixed-side inner shield 21 protrudes in the direction of the movable-side energizing shaft 7 and is disposed so as to wrap the movable-side contact 6, it is possible to suppress the diffusion of metal vapor to the vacuum insulating container 1 side. . Although the arc shield used in Example 1 is removed, most of the metal vapor is captured on the inner surface of the vacuum metal container 20.

  Even if the outer diameter of the vacuum insulating container 20 is increased, the insulation thickness of the insulating layer 12 on the outer peripheral part of the vacuum metal container 20 and the outer peripheral part of the fixed-side outer shield 10 is approximately the same, and the dielectric strength decreases. Will not be invited. If the outer diameter of the vacuum metal container 20 is made larger than that of the fixed-side outer shield 10, the insulation thickness is reduced, which is not preferable.

  According to the vacuum valve of the second embodiment, in addition to the effect of the first embodiment, the outer diameter of the vacuum metal container 20 can be increased, so that the electric field strength of the fixed side contact 5 and the movable side contact 6 is reduced. be able to.

  Next, a vacuum valve according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view illustrating a configuration of a vacuum valve according to Embodiment 3 of the present invention. The third embodiment differs from the second embodiment in that the stationary contact is fixed to the vacuum metal container. In FIG. 3, 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. 3, the surface of the fixed side contact 5 opposite to the movable side contact 6 is fixed or brought into contact with the bottom of the vacuum metal container 20. The stationary energizing shaft 4 is fixed to the bottom of the vacuum metal container 20 by penetration.

  According to the vacuum valve of the third embodiment, in addition to the effects of the second embodiment, the axial length of the stationary energizing shaft 4 can be shortened, so the axial length of the vacuum valve is reduced. can do.

  Next, a vacuum valve according to Embodiment 4 of the present invention will be described with reference to FIG. FIG. 4 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 third embodiment in that a shield is provided on the movable member. In FIG. 4, the same components as those in the third embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, an electrode shield 22 made of a metal material such as stainless steel or copper-chromium alloy is provided in a portion from the outer peripheral portion of the movable contact 6 to the joint portion with the movable energizing shaft 7. In addition, a current-carrying shaft shield 23 made of the same metal material as described above is provided on the outer peripheral portion where the movable-side current shaft 7 faces the vacuum metal container 20 and the fixed-side inner shield 21. The shields 22 and 23 made of such a metal material may be fixed in a cylindrical shape, and are particularly resistant in a vacuum than a copper material such as oxygen-free copper used for the movable contact 6 and the movable conductive shaft 7. The voltage characteristics can be improved.

  According to the vacuum valve of the fourth embodiment, in addition to the effects of the third embodiment, the withstand voltage characteristics on the movable side can be improved.

Sectional drawing which shows the structure 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 conventional vacuum valve.

Explanation of symbols

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 Fixed side outer shield 11 Movable side outer shield 12 Insulating layer 13 Grounding layer 20 Vacuum metal container 21 Fixed internal shield 22 Electrode shield 23 Current-carrying shaft shield

Claims (2)

A tubular vacuum insulated container;
A cup-shaped vacuum metal container having a peripheral edge sealed to one end opening of the vacuum insulating container;
A fixed-side energizing shaft that is fixed to the bottom of the vacuum metal container;
A fixed-side contact fixed to the fixed-side energizing shaft end;
A movable-side sealing fitting sealed at the other end opening of the vacuum insulating container;
A movable-side energizing shaft that movably penetrates the movable-side sealing fitting;
A movable side contact fixed to the movable side energizing shaft end and contacting and leaving the fixed side contact;
A telescopic bellows whose one end is sealed to an intermediate portion of the movable-side energizing shaft and whose other end is sealed to the movable-side sealing metal fitting,
An insulating layer provided on an outer periphery of the vacuum metal container and the vacuum insulating container;
A grounding layer provided on the outer periphery of the insulating layer ,
The outer diameter of the stationary contact is made larger than that of the movable contact, the coil electrode for generating a longitudinal magnetic field is attached to these contacts, and the outer diameter of the coil electrode on the stationary side is made larger than the movable side. A vacuum valve characterized by 2. The vacuum valve according to claim 1 , wherein an electrode shield is provided on an outer peripheral portion of the movable side contact, and an energizing shaft shield is provided on an outer peripheral portion of the movable side energizing shaft facing the vacuum metal container .

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