JP2014182877A - Resin insulation vacuum valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain field relaxation in an end portion of a sealed metal fitting which is sealed to an opening of a vacuum insulation vessel.SOLUTION: A resin insulation vacuum valve comprises: a tubular vacuum insulation vessel 1; a fixed-side sealed metal fitting 2 which is sealed to one end opening of the vacuum insulation vessel 1; a movable-side sealed metal fitting 3 which is sealed to another end opening of the vacuum insulation vessel 1; a fixed-side high dielectric layer 10 which is provided to cover an end portion of the fixed-side sealed metal fitting 2; a movable-side high dielectric layer 11 which is provided to cover an end portion of the movable-side sealed metal fitting 3; a main insulation layer 13 which is provided around the vacuum insulation vessel 1, the fixed-side high dielectric layer 10 and the movable-side high dielectric layer 11; and a grounding layer 14 which is provided around the main insulation layer 13. The resin insulation vacuum valve is characterized in that both of the end openings of the vacuum insulation vessel 1 are made into thin diameter portions 1a and 1b and an intermediate part is made into a thick diameter portion 1c.

Description

  Embodiments described herein relate generally to a resin-insulated vacuum valve obtained by molding a vacuum valve with an insulating material.

  Conventionally, a vacuum valve having a pair of contactable and separable contacts is molded with an epoxy resin to reinforce external insulation. In the molding, it is known to provide a bowl-shaped electric field relaxation shield that covers the outer periphery of the sealing fitting in order to relax the electric field of the sealing fitting constituting the vacuum valve (see, for example, Patent Document 1). .)

  The electric field relaxation shield is made of a metal material such as a copper material, covers the sealing metal fitting, and is fixed to the outer periphery on the coaxial axis of the vacuum insulating container with a predetermined gap. However, the gap varies depending on the assembling method, and in an extreme case, the inner surface of the electric field relaxation ring may contact the outer surface of the vacuum insulating container. In the contact portion, a minute gap is formed, and the electric field strength increases.

  The electric field relaxation ring is, for example, passed through a bolt through the through hole and fastened and fixed to the sealing metal fitting. However, the electric field relaxation ring may be eccentric depending on the processing error or the size of the inner diameter of the through hole. For this reason, processing and assembly must be performed with great care, which is a difficult task. This operation is prepared before molding.

JP 2012-243581 A

  The problem to be solved by the present invention is to provide a resin-insulated vacuum valve that can reduce the electric field at the end of the sealing fitting without providing an electric field relaxation ring and can improve workability before molding. is there.

  In order to solve the above-mentioned problems, a resin insulated vacuum valve according to an embodiment includes a cylindrical vacuum insulated container, a fixed-side sealing metal fitting sealed at one end opening of the vacuum insulated container, and the vacuum insulated container A movable-side sealing metal fitting sealed at the other end opening, a fixed-side high-permittivity layer provided so as to cover the fixed-side sealing metal edge, and an end portion of the movable-side sealing metal fitting A movable-side high dielectric constant layer, a vacuum insulating container, the fixed-side high dielectric constant layer, a main insulating layer provided around the movable-side high dielectric constant layer, and the surroundings of the main insulating layer A resin-insulated vacuum valve provided with a grounding layer provided on the inside of the vacuum insulating container, wherein both ends of the vacuum insulating container have a small diameter portion and an intermediate portion has a large diameter portion.

1 is a half cross-sectional view showing a configuration of a resin insulated vacuum valve according to Embodiment 1 of the present invention. FIG. 6 is a half cross-sectional view showing a configuration of a resin insulated vacuum valve according to Embodiment 2 of the present invention.

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

  First, a resin insulated vacuum valve according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a half cross-sectional view showing a configuration of a resin insulated vacuum valve according to Embodiment 1 of the present invention.

  As shown in FIG. 1, at both ends of a cylindrical vacuum insulating container 1 made of alumina porcelain, a disk-shaped fixed-side sealing metal fitting 2 having an outer diameter similar to the outer diameter of the opening and a movable-side sealing are provided. The fitting 3 is sealed. The vacuum insulating container 1 has a fixed-side narrow-diameter portion 1a, a movable-side thin-diameter portion 1b, and an intermediate portion having a large-diameter portion 1c. 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. An intermediate portion of the movable energizing shaft 7, which is fixed to the end of the movable energizing shaft 7, which faces the fixed contact 5, and which is movable to and away from the movable side sealing fitting 3. One end of the expandable bellows 8 is sealed to the part, and the other end is sealed to the opening of the movable side sealing fitting 3. A cylindrical arc shield 9 is provided around the contacts 5 and 6 to prevent diffusion of metal vapor.

  A fixed-side high dielectric constant layer 10 is provided around the fixed-side sealing metal fitting 2 so as to cover the end portion and fill the fixed-side narrow diameter portion 1a. The movable-side sealing metal fitting 3 is also provided with a movable-side high dielectric constant layer 11 so as to cover the end portion and fill the movable-side narrow diameter portion 1b. A resin intrusion prevention pipe 12 is provided around the movable side energizing shaft 7. Around the large-diameter portion 1c, the high dielectric constant layers 10 and 11, and the resin intrusion prevention tube 12 of the vacuum insulating container 1, a main insulating layer 13 for forming a main insulation molded with an epoxy resin is provided. A ground layer 14 is provided on the outer periphery of the main insulating layer 13. Note that tapered interface connection portions are provided at both ends in the axial direction of the main insulating layer 13 to connect with other electrical devices.

  Here, the main insulating layer 13 is a general epoxy resin and has a relative dielectric constant of 3 to 4, and the vacuum insulating container 1 is a general ceramic having a relative dielectric constant of 6 to 8. The high dielectric constant layers 10 and 11 are filled with epoxy resin such as titanium oxide and barium titanate, and have a relative dielectric constant of 10 or more. That is, the relative dielectric constant is larger than that of the main insulating layer 13 and the vacuum insulating container 1 and is formed by a two-stage mold.

  As a result, the fixed-side and movable-side sealing metal fittings 2 and 3 are provided with the fixed-side and movable-side high dielectric constant layers 10 and 11 so as to cover the ends. A gradient dielectric layer with a relative dielectric constant lowering toward the base layer 14 can be obtained, and the electric field distribution can be improved. As the insulating thickness of the high dielectric constant layers 10 and 11 is increased, the electric field can be relaxed, but the main insulating layer 13 is not exceeded. That is, the insulating thickness of the main insulating layer 13 is made thicker than that of the high dielectric constant layers 10 and 11 to provide the electrical and mechanical strength imposed on the device. Although a larger dielectric constant has an electric field relaxation effect, it is difficult to mix a large amount of high dielectric constant powder, so a dielectric constant of about 30 is preferable in terms of material preparation. In addition, the preparation work for the electric field relaxation ring as in the prior art can be made unnecessary, and the number of parts can be reduced.

  According to the resin-insulated vacuum valve of Example 1 above, the high dielectric constant layers 10 and 11 are formed so that the opening portions at both ends of the vacuum insulating container 1 have the narrow diameter portions 1a and 1b and cover the ends of the sealing fittings 2 and 3, respectively. Therefore, it is possible to reduce the electric field at the ends of the sealing fittings 2 and 3. Moreover, the preparatory work before molding can be facilitated.

  Next, a resin insulated vacuum valve according to Example 2 of the present invention will be described with reference to FIG. FIG. 2 is a half cross-sectional view showing the configuration of the resin insulated vacuum valve according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in that an intermediate potential exists. 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, two vacuum insulating containers 20 a and 20 b are connected by a sealing tube 21. The vacuum insulating containers 20a and 20b have a fixed-side narrow diameter portion 20a1, an intermediate small-diameter portion 20a2, 20b1, a movable-side small-diameter portion 20b2, and an intermediate portion having large-diameter portions 20a3 and 20b3, respectively. An intermediate high dielectric constant layer 22 similar to the high dielectric constant layers 10 and 11 is provided around the sealing tube 21 so as to fill the narrow diameter portions 20a2 and 20b1 and cover the sealing tube 21. The sealing tube 21 is about 50% of the intermediate potential. The intermediate high dielectric constant layer 22 may have an insulating thickness smaller in proportion to the potential than the fixed and movable high dielectric constant layers 10 and 11.

  According to the resin-insulated vacuum valve of the second embodiment, in addition to the effects of the first embodiment, the openings of the vacuum insulating containers 20a and 20b for sealing the sealing tube 21 having an intermediate potential are formed in the small diameter portions 20a2 and 20b1. Since the high dielectric constant layer 22 is provided, the electric field can be relaxed.

  According to the embodiment as described above, since the high dielectric constant layer is provided so as to cover the sealing metal fitting, the gradient dielectric layer whose relative dielectric constant decreases as the insulating layer up to the ground layer becomes the ground layer, and It is possible to reduce the electric field at the end of the sealing fitting.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1, 20a, 20b Vacuum insulation container 1a, 20a1 Fixed side small diameter part 1b, 20b2 Movable side small diameter part 1c, 20a3, 20b3 Large diameter part 2 Fixed side sealing metal fitting 3 Moving side sealing metal fitting 10 Fixed side high dielectric constant Layer 11 Movable side high dielectric constant layer 13 Main insulating layer 14 Ground layers 20a2 and 20b1 Intermediate small diameter portion 22 Intermediate high dielectric constant layer

Claims (5)

A tubular vacuum insulated container;
A fixed-side sealing fitting sealed at one end opening of the vacuum insulating container;
A movable-side sealing fitting sealed at the other end opening of the vacuum insulating container;
A fixed-side high dielectric constant layer provided so as to cover the end of the fixed-side sealing metal fitting,
A movable high dielectric constant layer provided so as to cover the end of the movable sealing metal fitting,
A main insulating layer provided around the vacuum insulating container, the fixed high dielectric constant layer, the movable high dielectric constant layer;
A resin-insulated vacuum valve comprising a ground layer provided around the main insulating layer,
A resin-insulated vacuum valve characterized in that the opening at both ends of the vacuum insulating container has a small diameter portion and the middle portion has a large diameter portion.   Two of the vacuum insulating containers are connected by a sealing tube, and the openings of the vacuum insulating containers connected by the sealing tube are made into small diameter portions, respectively, and an intermediate high dielectric constant layer is formed so as to cover the sealing tube. The resin-insulated vacuum valve according to claim 1, wherein the resin-insulated vacuum valve is provided.   3. The resin according to claim 1, wherein a relative dielectric constant of the fixed high dielectric constant layer and the movable high dielectric constant layer is made larger than that of the vacuum insulating container and the main insulating layer. Insulated vacuum valve.   4. The resin according to claim 1, wherein an insulation thickness of the main insulating layer is made thicker than that of the fixed high-permittivity layer and the movable high-permittivity layer. 5. Insulated vacuum valve.   The resin-insulated vacuum valve according to any one of claims 1 to 4, wherein a relative dielectric constant of the fixed high-dielectric constant layer and the movable high-dielectric constant layer is set to 10 to 30.