Vacuum arc-extinguishing chamber with external insulation shielding structure and circuit breaker

Abstract

The invention discloses a vacuum arc-extinguishing chamber with an external insulation shielding structure and a circuit breaker, and belongs to the technical field of vacuum arc-extinguishing chambers. The structure comprises a porcelain shell, a sealing ring, an outer shielding case and an inner shielding case, the contact end face of the porcelain shell is provided with a metallization layer. The sealing ring is located on the contact end face of the ceramic shell and is fixedly connected with the metallization layer; the inner shielding cover is positioned in the inner cavity of the ceramic shell and is fixedly connected with the sealing ring; and the outer shielding cover is sleeved outside the porcelain shell and is clamped with the sealing ring. The structure can obviously improve the insulation of the outer edge surface of the ceramic shell of the vacuum arc-extinguishing chamber, and solves the problem that the insulation difficulty of the edge surface of the ceramic shell is obviously improved after the vacuum arc-extinguishing chamber enters the tank-type circuit breaker. According to the invention, assembling can be directly carried out on the whole pipe of the processed vacuum arc-extinguishing chamber, the installation of the shielding cover outside the vacuum arc-extinguishing chamber can be rapidly and accurately realized through rotating and clamping, the installation process is simplified, and the installation difficulty and cost are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of vacuum interrupter chambers, and relates to a vacuum interrupter chamber and a circuit breaker with an external insulating shielding structure. Background Art

[0002] Existing high-voltage circuit breakers generally use SF6 gas as electrical insulation and circuit breaking medium, but SF6 gas is a greenhouse gas with a very long atmospheric life. The greenhouse effect has a great impact and causes serious pollution to the environment. Therefore, replacing SF6 becomes particularly important. At present, one of the most common SF6 replacement methods in high-voltage circuit breakers is to use a vacuum interrupter as a breaking element, and use environmentally friendly gases as the external insulating medium, such as N2, C02, clean air, etc., but the dielectric constant of environmentally friendly gases is usually much lower than that of SF6.

[0003] When welding the vacuum interrupter, the upper and lower end faces of the porcelain shell must be metallized, which is equivalent to plating a layer of metal on the surface of the porcelain shell. This process will lead to two effects. First, this metallization layer is equivalent to a metal sheet. When the vacuum interrupter is placed in the circuit breaker and the fracture is pressurized, there is a risk of tip discharge, which will damage the insulation level of the circuit breaker; second, this metallization layer forms a three-phase junction with the porcelain shell and the external insulating medium in this area. This area is inevitably degraded by insulation due to force majeure factors such as structural design and processing defects. If this area is not treated, the insulation level of the circuit breaker will also be damaged. Third, after the vacuum interrupter is placed in the circuit breaker, especially the tank circuit breaker, the insulation level along the porcelain shell surface is significantly reduced because the shell is grounded and too close to the vacuum interrupter porcelain shell. Therefore, an external shielding cover must be installed in the sealing area of ​​the vacuum interrupter porcelain shell for insulation optimization.

[0004] At present, the shielding cover outside the vacuum interrupter is mostly formed in one piece with the shielding cover inside the vacuum interrupter, which has a complicated process. Moreover, the one-piece shielding cover can only shield the tip discharge of the metallization layer of the porcelain shell, and it is difficult to make the electric field of the three-intersection area uniform. Summary of the invention

[0005] The object of the present invention is to provide a vacuum interrupter and a circuit breaker with an external insulation shielding structure, so as to solve the technical problem in the prior art that the difficulty of insulation along the porcelain shell surface is significantly increased after the interrupter enters the tank circuit breaker.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a vacuum arc extinguishing chamber with an external insulating shielding structure, comprising a porcelain shell, a sealing ring, an outer shielding cover and an inner shielding cover; the contact end face of the porcelain shell is provided with a metallized layer; the sealing ring is located on the contact end face of the porcelain shell, and the sealing ring is fixedly connected to the metallized layer; the inner shielding cover is located in the inner cavity of the porcelain shell, and is fixedly connected to the sealing ring; the outer shielding cover is sleeved on the outside of the porcelain shell, and is clamped with the sealing ring.

[0007] Furthermore, the sealing ring comprises an annular clamping portion and a clamping interval which are arranged in sequence at intervals; the annular clamping portion extends to the outside of the porcelain shell and is clamped with the outer shielding cover.

[0008] Furthermore, the inner wall of the outer shielding cover has a plurality of limiting parts, each limiting part is provided with a groove as an insertion gap along a direction perpendicular to the axis of the outer shielding cover, and the insertion gap is used to limit the annular clamping part.

[0009] Furthermore, the width of the insertion gap is greater than the thickness of the annular clamping portion.

[0010] Furthermore, the inner shielding cover is a cylindrical structure, and both ends of the inner shielding cover have flanges.

[0011] Furthermore, the outer shielding cover is a cylindrical structure, and the two ends of the outer shielding cover respectively have an upper flange and a lower flange, and the upper flange and the lower flange are both outward flanges.

[0012] Furthermore, the height H1 of the upper flange and the height H2 of the lower flange are both greater than 15 mm; the chamfer R1' of the upper flange and the chamfer R2' of the lower flange are both greater than 8 mm.

[0013] Furthermore, the maximum radius R1 of the sealing ring is greater than the minimum radius R3 of the outer shielding cover, and smaller than the maximum radius R2 of the outer shielding cover.

[0014] Furthermore, the outer shielding cover is made of aluminum alloy material.

[0015] In a second aspect, the present invention provides a circuit breaker, comprising the above-mentioned vacuum arc extinguishing chamber with an external insulation shielding structure.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a vacuum arc chamber and a circuit breaker with an external insulation shielding structure. The setting of the external shielding cover can significantly improve the insulation of the outer edge of the porcelain shell of the vacuum arc chamber, solve the problem that the difficulty of insulating the porcelain shell along the surface is significantly increased after the vacuum arc chamber enters the tank circuit breaker, and improve the insulation performance of the product; improve the electromagnetic compatibility and operation reliability of the equipment. In addition, the present invention also provides an installation method of the outer shielding cover of the vacuum arc chamber. Through the method of rotating and snapping the outer shielding cover in the method, the vacuum arc chamber can be welded first, and then the outer shielding cover can be snapped in. The outer shielding cover does not need to enter the vacuum furnace for brazing. This method can be directly assembled on the whole tube of the vacuum arc chamber after processing. The installation of the outer shielding cover of the vacuum arc chamber can be realized quickly and accurately by rotating and snapping. The structure and process of the inner shielding cover of the vacuum arc chamber using this installation method do not change much, and will not cause the increase of cost and processing difficulty. The limit part using this method can be set integrally with the outer shielding cover of the vacuum arc chamber, which has higher strength and is easier to form. This design simplifies the installation process and reduces the installation difficulty and cost. At the same time, the card-joint structure also facilitates subsequent maintenance and replacement work, improving the maintainability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a schematic diagram of the overall installation structure of the present invention; Figure 2 It is a schematic diagram of the structure of the inner shielding cover of the present invention; Figure 3 It is a schematic diagram of the structure of the outer shielding cover of the present invention; Figure 4 is a cross-sectional view of the outer shielding cover of the present invention; Figure 5 It is a schematic structural diagram of the sealing ring of the present invention.

[0019] Among them: 1-ceramic shell; 2-metallized layer; 3-outer shielding cover; 4-sealing ring; 301-limiting part; 302-upper flange; 303-insertion gap; 304-lower flange; 401-annular clamping part; 402-flange; 403-clamping interval; 5-inner shielding cover. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0023] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0024] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings: See also Figure 1 and Figure 5 The present invention discloses a vacuum arc extinguishing chamber with an external insulating shielding structure, comprising a porcelain shell 1, a sealing ring 4, an inner shielding cover 5 and an outer shielding cover 3; the porcelain shell 1 has a metallized layer 2 on its contact end surface; the sealing ring 4 is fixedly connected to the metallized layer 2, and the inner shielding cover 5 is located in the inner cavity of the porcelain shell 1; the outer shielding cover 3 is sleeved on the outside of the porcelain shell 1 and is clamped with the sealing ring 4. Through the dual arrangement of the inner shielding cover 5 and the outer shielding cover 3, an effective electromagnetic shielding layer is formed, which can significantly reduce the influence of the external electromagnetic field on the inside of the vacuum arc extinguishing chamber, not only shielding the tip discharge of the porcelain shell metallized layer, but also uniformizing the electric field of the three-intersection area; improving the electromagnetic compatibility and operation reliability of the equipment. For the existing patents of the integrated design of the outer shielding cover 5 and the sealing ring 4, the integration is difficult to design and process, and must be welded in a vacuum furnace. The outer shielding cover 5 that is too large and too heavy not only occupies space, but also easily makes the welding part contact poor, resulting in uneven distribution of solder, thereby affecting the airtightness of the welding. By rotating and snapping the outer shielding cover 5 in the present method, the vacuum arc chamber can be welded first, and then the outer shielding cover 5 can be snapped in. The outer shielding cover does not need to be brazed in a vacuum furnace, so the outer shielding cover 5 can be made of lightweight aluminum alloy material, which not only meets the performance requirements but also has low cost.

[0027] In a possible embodiment of the present invention, see Figure 2 The sealing ring 4 includes an annular clamping portion 401 and a clamping interval 403 which are arranged in sequence; the annular clamping portion 401 extends to the outside of the porcelain shell 1 and is clamped with the outer shielding cover 3.

[0028] In a possible embodiment of the present invention, see Figure 3 and Figure 4 The inner wall of the outer shielding cover 3 has a plurality of limiting parts 301, each limiting part 301 is provided with a groove as an insertion gap 303 along a direction perpendicular to the axis of the outer shielding cover 3, and the insertion gap 303 is used to limit the annular clamping part 401.

[0029] In a feasible embodiment of the present invention, the width of the insertion gap 303 is greater than the thickness of the annular clamping portion 401 , and the maximum radius R1 of the sealing ring 4 is greater than the minimum radius R3 of the outer shielding cover 3 and smaller than the maximum radius R2 of the outer shielding cover 3 .

[0030] In a feasible embodiment of the present invention, the two ends of the inner shielding cover 5 have flanges 402. In order to optimize the external electric field of the vacuum interrupter and improve the insulation performance, the two ends of the outer shielding cover 3 have an upper flange 302 and a lower flange 304 respectively. The design features of the upper flange 302 include a height H1 and a rounding R1', and the design features of the lower flange 304 include a height H2 and a rounding R2'. The heights H1 and H2 must be greater than 15mm, and the roundings R1' and R2' must be greater than 8mm. According to the electric field simulation results, the height of the upper flange 302 and the lower flange 304 of the outer shielding cover is greater than or equal to 15mm, and the rounding of the upper flange 302 and the lower flange 305 is greater than or equal to 8mm, so as to achieve the desired electric field optimization effect.

[0031] An embodiment of the present invention discloses a circuit breaker, which includes the above-mentioned vacuum arc chamber with an external insulation shielding structure. The external insulation shielding structure can significantly improve the insulation of the outer edge surface of the porcelain shell of the vacuum arc chamber, and solve the problem that the difficulty of insulating the porcelain shell surface is significantly increased after the vacuum arc chamber enters the tank circuit breaker.

[0032] The embodiment of the present invention discloses a method for installing the above-mentioned vacuum interrupter with an external insulation shielding structure, comprising the following steps: First, the inner shielding cover 5, the porcelain shell 1 and other parts of the vacuum interrupter are brazed in a vacuum furnace to obtain a vacuum interrupter with a vacuum state inside; The outer shielding cover 3 is sleeved on the outside of the porcelain shell 1 of the vacuum interrupter, so that the limiting part 301 is correspondingly inserted into the clamping interval 403, and is screwed in from the clamping interval 403 and completely screwed into the annular clamping part 401, and then fixed to complete the installation of the vacuum interrupter shielding cover.

[0033] In this embodiment, the outer shielding cover 3 is sleeved on the outside of the porcelain shell 1 and connected to the inner shielding cover 5 by a snap-fitting method. This design simplifies the installation process and reduces the installation difficulty and cost. At the same time, the snap-fitting structure also facilitates subsequent maintenance and replacement work, improving the maintainability of the equipment.

[0034] The installation principle of the present invention is as follows: During the production process of the vacuum interrupter, the porcelain shell 1 and the inner shielding cover 5 must be brazed together with the contacts, conductive rods and other parts of the vacuum interrupter in the vacuum furnace. The vacuum interrupter that has been welded in the vacuum furnace has become a completed individual, and the interior is in a vacuum state. Then, during the assembly process of the vacuum circuit breaker, the outer shielding cover 3 of the vacuum interrupter is inserted into the porcelain shell 1 of the vacuum interrupter, and the limiting portion 301 is inserted into the clamping interval 403 one by one, and is screwed in from the clamping interval 403 and completely screwed into the annular clamping portion 401, and finally fixed with screws or glue to complete the installation of the outer shielding cover of the vacuum interrupter. The maximum radius R1 of the sealing ring 4 is greater than the minimum radius R3 of the outer shielding cover 3, and is smaller than the inner diameter R2 of the outer shielding cover 3 of the vacuum interrupter. The present invention can be directly assembled on the whole tube of the vacuum interrupter after processing, and the installation of the outer shielding cover of the vacuum interrupter can be realized quickly and accurately by rotating and clamping. The structure and process of the inner shielding cover of the vacuum interrupter using this installation method have not changed much, and will not cause an increase in cost and processing difficulty. The limiting part using this method can be integrally arranged with the outer shielding cover of the vacuum arc extinguishing chamber, which has higher strength and is easier to form.

[0035] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A vacuum interrupter with an external insulation shielding structure, characterized in that: The invention comprises a ceramic shell (1), a sealing ring (4), an outer shielding cover (3) and an inner shielding cover (5); the ceramic shell (1) has a metallized layer (2) on its contact end surface; the sealing ring (4) is located on the contact end surface of the ceramic shell (1), and the sealing ring (4) is fixedly connected to the metallized layer (2); the inner shielding cover (5) is located in the inner cavity of the ceramic shell (1), and is fixedly connected to the sealing ring (4); the outer shielding cover (3) is sleeved on the outside of the ceramic shell (1), and is clamped to the sealing ring (4).

2. A vacuum interrupter with an external insulation shielding structure according to claim 1, characterized in that: The sealing ring (4) comprises an annular clamping portion (401) and a clamping interval (403) which are arranged in sequence at intervals; the annular clamping portion (401) extends to the outside of the porcelain shell (1) and is clamped with the outer shielding cover (3).

3. The vacuum interrupter with an external insulation shielding structure according to claim 2, characterized in that: The inner wall of the outer shielding cover (3) has a plurality of limiting portions (301), each limiting portion (301) is provided with a groove as an insertion gap (303) along a direction perpendicular to the axis of the outer shielding cover (3), and the insertion gap (303) is used to limit the annular clamping portion (401).

4. The vacuum interrupter with an external insulation shielding structure according to claim 3, characterized in that: The width of the insertion gap (303) is greater than the thickness of the annular clamping portion (401).

5. The vacuum interrupter with an external insulation shielding structure according to claim 3, characterized in that: The inner shielding cover (5) is a cylindrical structure, and both ends of the inner shielding cover (5) have flanges (402).

6. The vacuum interrupter with an external insulation shielding structure according to claim 3, characterized in that: The outer shielding cover (3) is a cylindrical structure, and the two ends of the outer shielding cover (3) respectively have an upper flange (302) and a lower flange (304), and both the upper flange (302) and the lower flange (304) are outward flanges.

7. The vacuum interrupter with an external insulation shielding structure according to claim 6, characterized in that: The height H1 of the upper flange (302) and the height H2 of the lower flange (304) are both greater than 15 mm; the rounding R1' of the upper flange (302) and the rounding R2' of the lower flange (304) are both greater than 8 mm.

8. The vacuum interrupter with an external insulation shielding structure according to claim 3, characterized in that: The maximum radius R1 of the sealing ring (4) is greater than the minimum radius R3 of the outer shielding cover (3), and smaller than the maximum radius R2 of the outer shielding cover (3).

9. The vacuum interrupter with an external insulation shielding structure according to claim 3, characterized in that: The outer shielding cover (3) is made of aluminum alloy material.

10. A circuit breaker, characterized in that: It comprises a vacuum interrupter with an external insulating shielding structure as described in any one of claims 1 to 9.

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