JP2011048997A - Mold vacuum valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To disperse stress inside an insulating layer formed between an electric field relaxing shield and a vacuum insulating container to suppress generation of insulating defects. <P>SOLUTION: A valve includes a fixing-side sealing fitting 2 and a movable-side sealing fitting 3 sealed to both end openings in the vacuum insulating container 1; a fixing-side contact 5 and a movable-side contact 6, which are contained in the vacuum insulating container 1 and freely brought into contact/out of contact with each other; a fixing-side electric field relaxing shield 20, provided to cover an outer peripheral end of the fixing-side sealing fitting 2; a movable-side electric field relaxing shield 21 provided to cover an outer peripheral end of the movable-side sealing fitting 3; and the insulating layer 12, formed on the outer peripheries of the vacuum container 1 and the electric field relaxing shields 20, 21. The electric field relaxing shields 20, 21 are respectively constituted of radially expanding fixing parts 20a, 21a, and axially extending relaxing parts 20b, 21b, and inner peripheral surfaces of the relaxing parts 20b, 21b are provided with recessed curved surfaces. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a molded vacuum valve in which a vacuum valve having a pair of contactable and separable contacts is molded with an insulating material such as an epoxy resin, and an insulating layer is formed on the outer periphery.

  Conventionally, in a vacuum valve molded with an epoxy resin, since the end of a sealing fitting constituting the vacuum valve has an acute angle and the electric field strength is increased, an electric field relaxation shield that covers this is known. (For example, refer to Patent Document 1).

  A mold vacuum valve of this type is shown in FIG. 6, and a fixed-side sealing fitting 2 and a movable-side sealing fitting 3 are sealed at both end openings of a vacuum insulating container 1 made of cylindrical ceramics. 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. The movable contact 6 is fixed to the end of the movable energizing shaft 7 that movably penetrates the movable sealing fitting 3 so as to face the fixed contact 5.

  One end of a telescopic bellows 8 is sealed at an intermediate portion of the movable energizing shaft 7. The other end is sealed in the opening of the movable side sealing fitting 3. A cylindrical arc shield 9 provided so as to surround the contacts 5 and 6 is fixed to the inner surface of the vacuum insulating container 1.

  A hook-shaped fixed-side electric field relaxation shield 10 is fixed to the fixed-side sealing fitting 2 so as to cover the outer peripheral end portion thereof. The end of the fixed-side electric field relaxation shield 10 extends until it wraps with the end of the vacuum insulating container 1. In addition, a hook-like movable-side electric field relaxation shield 11 is fixed to the movable-side sealing metal fitting 3 so as to cover the outer peripheral end portion thereof. The end of the movable-side electric field relaxation shield 11 also extends until it wraps with the end of the vacuum insulating container 1. The electric field relaxation shields 10 and 11 are generally made of a copper material having good workability.

  An insulating layer 12 formed by molding with an epoxy resin is provided on the outer periphery of the vacuum insulating container 1 and the electric field relaxation shields 10 and 11. On the outer periphery of the insulating layer 12, a ground layer 13 formed by applying a conductive paint is provided. The axial direction on the fixed side of the insulating layer 12 is a concave interface connecting portion 14, and the movable side is a convex interface connecting portion 15, which is connected to other electrical devices.

JP 2005-276472 A (page 4, FIG. 1)

  The above-described conventional mold vacuum valve has the following problems. The fixed-side electric field relaxation shield 10 and the movable-side electric field relaxation shield 11 can reduce the electric field at the ends of the fixed-side sealing metal fitting 2 and the movable-side sealing metal fitting 3. The electric field relaxation shields 10 and 11 expand in the radial direction, then bend approximately 90 degrees in the axial direction, and extend until the end portion is overlapped with the vacuum insulating container 1. That is, the electric field relaxation shields 10 and 11 have an L-shaped cross section, and the portions extending in the axial direction are arranged coaxially with the vacuum insulating container 1.

  Therefore, the insulating layer 12 between the vacuum insulating container 1 and the portion where the electric field relaxation shields 10 and 11 extend in the axial direction has a rectangular cross section, and the inner peripheral surface and the outer peripheral surface are substantially parallel, Will be. The vacuum insulating container 1, the electric field relaxation shields 10, 11 and the insulating layer 12 are all made of different materials and have different thermal expansion coefficients. For this reason, when a temperature change occurs during molding or the usage environment, stress is generated in the constrained insulating layer 12, and the insulating layer 12 may be peeled off from the vacuum insulating container 1 or the electric field relaxation shields 10 and 11. . Furthermore, cracks may occur in the insulating layer 12.

  When an insulation defect such as peeling or cracking occurs in the insulating layer 12, partial discharge occurs, resulting in insulation deterioration. In particular, when a partial discharge is generated from the tips of the electric field relaxation shields 10 and 11, the deterioration of insulation progresses between the ground layers 13, leading to dielectric breakdown.

  The present invention has been made to solve the above-mentioned problems, and is intended to spread the stress of the insulating layer formed between the electric field relaxation shield provided on the outer periphery of the sealing metal fitting and the vacuum insulating container, and to prevent mold defects from causing insulation defects. The object is to provide a valve.

  In order to achieve the above object, the mold vacuum valve of the present invention includes a cylindrical vacuum insulation container, a fixed-side sealing metal fitting and a movable-side sealing metal fitting sealed at both ends of the vacuum insulation container, A fixed-side energizing shaft that is fixed through the fixed-side sealing metal fitting, a fixed-side contact that is fixed to the fixed-side energizing shaft end, a movable-side contact that is in contact with and away from the fixed-side contact; The movable-side energizing shaft that sticks and penetrates the movable-side sealing fitting in an airtight manner, the fixed-side electric field relaxation shield provided so as to cover the outer peripheral end of the fixed-side sealing fitting, and the movable A movable-side electric field relaxation shield provided so as to cover an outer peripheral end of the side sealing metal fitting, and an insulating layer formed by molding an insulating material on the outer periphery of the vacuum insulating container and the electric field relaxation shield, Each of the electric field relaxation shields has a radius It is composed of a relaxation portion extending the fixed part and axially extending direction, characterized in that to have a concave curved surface on the inner peripheral surface of the relaxed portion.

  According to the present invention, since the inner peripheral surface of the electric field relaxation shield is a curved surface, the stress distribution of the insulating layer formed between the vacuum insulating container and the electric field relaxation shield can be achieved, and insulation defects are less likely to occur. .

Sectional drawing which shows the structure of the mold vacuum valve which concerns on Example 1 of this invention. The principal part expanded sectional view which shows the structure of the electric field relaxation shield which concerns on Example 1 of this invention. The principal part expanded sectional view which shows the structure of the mold vacuum valve which concerns on Example 2 of this invention. The principal part expanded sectional view which shows the structure of the mold vacuum valve which concerns on Example 3 of this invention. The principal part expanded sectional view which shows the structure of the mold vacuum valve which concerns on Example 4 of this invention. Sectional drawing which shows the structure of the mold vacuum valve by a conventional method.

  The inner peripheral surface of the electric field relaxation shield that covers the end portion of the sealing metal fitting is formed as a concave curved surface, and the insulating layer formed between the vacuum insulating container has a curved surface to distribute stress. Embodiments according to the present invention will be described below with reference to the drawings.

  First, a mold vacuum valve according to Example 1 of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a configuration of a mold vacuum valve according to Embodiment 1 of the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part showing a configuration of an electric field relaxation shield 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, a fixed-side sealing metal fitting 2 and a movable-side sealing metal fitting 3 are sealed at both end openings of a vacuum insulating container 1 made of cylindrical ceramics. 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. The movable contact 6 is fixed to the end of the movable energizing shaft 7 that movably penetrates the movable sealing fitting 3 so as to face the fixed contact 5.

  One end of a telescopic bellows 8 is sealed at an intermediate portion of the movable energizing shaft 7. The other end is sealed in the opening of the movable side sealing fitting 3. Thereby, the movable energizing shaft 7 can be moved in the axial direction while maintaining the vacuum in the vacuum insulating container 1. A cylindrical arc shield 9 provided so as to surround the contacts 5 and 6 is fixed to the inner surface of the vacuum insulating container 1.

  A hook-shaped fixed-side electric field relaxation shield 20 is fixed to the fixed-side sealing fitting 2 so as to cover the outer peripheral end portion thereof. The fixed-side electric field relaxation shield 20 includes a fixed portion 20a that spreads in the radial direction and a relaxed portion 20b that is connected to the fixed portion 20a and bent in the axial direction. The relaxation portion 20b has a concave curved inner peripheral surface and extends until the tip wraps with the end portion of the vacuum insulating container 1.

  A hook-shaped movable-side electric field relaxation shield 21 is also fixed to the movable-side sealing fitting 3 so as to cover the outer peripheral end portion thereof. The movable-side electric field relaxation shield 21 is also composed of a fixed portion 21a that spreads in the radial direction and a relaxed portion 21b that is connected to the fixed portion 21a and bent in the axial direction. The relaxation portion 21b also has a concave curved inner peripheral surface, and extends until the tip of the relaxation portion 21b wraps with the end of the vacuum insulating container 1, maintaining a predetermined insulation distance from the tip of the relaxation portion 20b on the fixed side. It is separated.

  The electric field relaxation shields 20 and 21 are made of a metal material such as copper material or alumina having good workability. The relaxation portions 20b and 21b are formed by drawing or the like that bends a thin plate, and are fixed to the fixing portions 20a and 21a by brazing or the like. Further, as shown in FIG. 2, each of the relaxing portions 20b and 21b has a semicircular cross section with a radius of curvature R1 at the intermediate portion and a semicircular cross section with a radius of curvature R2 that is smaller than the radius of curvature R1. Yes.

  An insulating layer 12 formed by molding with an epoxy resin is provided on the outer periphery of the vacuum insulating container 1 and the electric field relaxation shields 20 and 21. On the outer periphery of the insulating layer 12, a ground layer 13 formed by applying a conductive paint is provided. The axial direction on the fixed side of the insulating layer 12 is a concave interface connecting portion 14, and the movable side is a convex interface connecting portion 15, which is connected to other electrical devices.

  Thereby, although the insulating layer 12 formed between the vacuum insulation container 1 and the relaxation parts 20b and 21b of the electric field relaxation shields 20 and 21 is linear on the vacuum insulation container 1 side, an intermediate part on the relaxation parts 20b and 21b side. Has a curved surface with a semicircular cross section with a radius of curvature R1 and a radius of curvature R2 with the tip connected to the radius of curvature R1. In the arc-shaped insulating layer 12 having a continuous curved surface as described above, stress is not easily concentrated at a specific location, and is dispersed over the entire curved surface, so that insulation defects such as peeling and cracks are hardly generated. Moreover, since the relaxation parts 20b and 21b are thin plates, the residual stress can be absorbed.

  In addition, although the curvature radius R2 is so good that it is large, the electric field relaxation shields 20 and 21 are enlarged. Conversely, when the radius of curvature R2 is small, stress concentration is likely to occur. For this reason, the curvature radius R2 is preferably 1/5 to 1/20 of the curvature radius R1.

  Furthermore, although the relaxation portions 20b and 21b form ground-to-ground insulation with the ground layer 13, the shortest insulation distance portion becomes a curved portion having a large curvature radius R1, and electric field relaxation can be achieved. The insulating layer 12 formed between the relaxing portions 20b and 21b and the ground layer 13 is free from large stress because the ground layer 13 side is released.

  According to the mold vacuum valve of the first embodiment, the inner peripheral surfaces of the relaxation portions 20b and 21b of the electric field relaxation shields 20 and 21 fixed to the sealing fittings 2 and 3 are concave curved surfaces. And the insulating layer 12 formed between the relaxing portions 20b and 21b has a shape having a semicircular curved surface, can distribute stress, and is less likely to cause insulation defects such as peeling and cracking. it can.

  Next, a mold vacuum valve according to a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is an enlarged cross-sectional view showing a main part of the configuration of the mold vacuum valve according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in the shape of the electric field relaxation shield. 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. Since the fixed side and the movable side have the same shape, description will be made using the fixed side.

  As shown in FIG. 3, the relaxation portion 20c of the fixed-side electric field relaxation shield 20 has a curved surface similar to the tip portion on the fixed portion 20a side. That is, it has a C-shaped cross section.

  According to the mold vacuum valve of Example 2, the stress distribution of the insulating layer 12 formed between the vacuum insulating container 1 and the relaxing portion 20b can be further promoted.

  Next, a mold vacuum valve according to Example 3 of the present invention will be described with reference to FIG. FIG. 4 is an enlarged cross-sectional view of a main part showing the configuration of the mold vacuum valve according to Example 3 of the present invention. The third embodiment is different from the first embodiment in the shape of the electric field relaxation shield. 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. In addition, it demonstrates using a fixed side electric field relaxation shield.

  As shown in FIG. 4, the relaxation part 20d of the fixed-side electric field relaxation shield 20 is obtained by machining a cylindrical inner peripheral surface of a thick plate into a concave curved surface. The relaxing part 20d is fixed to the fixing part 20a by brazing or the like. The relaxing portion 20d is a thicker plate than the fixed portion 20a.

  According to the mold vacuum valve of the third embodiment, in addition to the effect of the first embodiment, since the plate thickness of the relaxing portion 20d is increased, the heat capacity is increased and the residual stress in the insulating layer 12 during molding is suppressed. be able to.

  Next, a mold vacuum valve according to Example 4 of the present invention will be described with reference to FIG. FIG. 5 is an enlarged cross-sectional view of a main part showing the configuration of a mold vacuum valve according to Example 4 of the present invention. The fourth embodiment is different from the first embodiment in the shape of the electric field relaxation shield. 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. In addition, it demonstrates using a fixed side electric field relaxation shield.

  As shown in FIG. 5, the relaxation portion 20 e of the fixed-side electric field relaxation shield 20 is formed in a spiral shape having elasticity in the radial direction, for example, by drawing a thin plate. The relaxing part 20e is fixed to the fixing part 20a by brazing or the like.

  According to the mold vacuum valve of the fourth embodiment, in addition to the effect of the first embodiment, the relaxation portion 20e is made elastic so that the residual stress in the insulating layer 12 during molding can be suppressed. it can.

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, 20 Fixed side electric field relaxation shield 11, 21 Movable-side electric field relaxation shield 12 Insulating layer 13 Ground layers 14, 15 Interface connection portions 20a, 21a Fixed portions 20b, 20c, 20d, 20e, 21b Relaxation portions

Claims (5)

A tubular vacuum insulated container;
A fixed-side sealing metal fitting and a movable-side sealing metal fitting sealed at both ends of the vacuum insulating container; and
A fixed-side energizing shaft that is fixedly penetrated to the fixed-side sealing fitting;
A fixed-side contact fixed to the fixed-side energizing shaft end;
A movable contact that contacts and separates from the fixed contact;
A movable side energizing shaft that sticks the movable side contact and penetrates the movable side sealing fitting in an airtight manner,
A fixed-side electric field relaxation shield provided to cover an outer peripheral end of the fixed-side sealing metal fitting,
A movable-side electric field relaxation shield provided so as to cover an outer peripheral end of the movable-side sealing metal fitting,
Comprising an insulating layer formed by molding an insulating material on the outer periphery of the vacuum insulating container and the electric field relaxation shield,
Each of the electric field relaxation shields is composed of a fixed portion extending in the radial direction and a relaxation portion extending in the axial direction, and a concave vacuum surface is provided on the inner peripheral surface of the relaxation portion.   The mold vacuum valve according to claim 1, wherein the relaxation portion has a C-shaped cross section.   The mold vacuum valve according to claim 1, wherein the relaxation portion has a spiral cross section.   The mold vacuum valve according to any one of claims 1 to 3, wherein the relaxation portion is formed by drawing.   2. The mold vacuum valve according to claim 1, wherein the relaxation portion is made thicker than the fixed portion, and a concave curved surface is formed on an inner peripheral surface of the relaxation portion.

Images