contact box

Abstract

The application provides a contact box and belongs to the technical field of electrical insulation. The contact box solves the problem of short service life of the existing contact box. The contact box comprises a body in a cylindrical shape with an open lower end and a high-voltage shielding net embedded in the body and matched with the inner cavity of the body. A protruding part is integrally formed on the side of the body and is provided with a wire outlet port communicated with the inner cavity of the body. The side of the high-voltage shielding net is provided with a clearance port matched with the wire outlet port. An extended shielding cover is fixedly connected to the side of the high-voltage shielding net at the clearance port. The extended shielding cover is embedded in the protruding part. The extended shielding cover is in a horn shape and gradually reduces in size along the direction of the wire outlet port extending into the inner cavity of the body. The contact box has the advantages of good insulation effect, long service life and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electrical insulation, and relates to a contact box. BACKGROUND

[0002] A high-voltage switch cabinet generally comprises a cabinet body and components such as a contact box, a bent partition plate and a bushing arranged in the cabinet body, wherein the main function of the contact box is to insulate the connection part of the incoming and outgoing lines to ensure the safe operation of the high-voltage switch cabinet. The conventional contact box currently comprises a box body made of insulating material, and the side wall of the upper part of the box body and the bottom part are respectively provided with an outgoing line port and an incoming line port, and a top part in the box body is connected with an insert for fixing a static contact which extends into the box body from the outgoing line port. When the contact box is used, the busbar and the moving contact are respectively extended into the box body from the outgoing line port and the incoming line port of the box body and contacted.

[0003] In order to reduce the partial discharge in the contact box, a contact box of a 40.5KV high-voltage switch cabinet has been disclosed in Chinese patent application No. 201120477835.8, which is embedded with a high-voltage shielding net in the contact box body, the high-voltage shielding net is connected with the insert in the contact box body, and the connection position of each conductive component is covered by the high-voltage shielding net, so as to eliminate the discharge phenomenon in the contact box body. However, in actual application, the air gap between the inner wall of the outgoing line port and the busbar is very small after the busbar is installed from the outgoing line port, and the discharge phenomenon will occur at the position when the contact box works, and the high-voltage shielding net can only eliminate the tip discharge phenomenon in the contact box body, which will affect the service life of the contact box. The other contact boxes with shielding function also have the similar problems.

[0004] In view of the phenomenon, the person skilled in the art can easily think of the following ways: 1. improving the machining precision of the surface of the busbar to avoid burrs and the like; 2. increasing the outgoing line port to increase the air gap between the busbar and the inner wall of the outgoing line port; and 3. using better insulating materials to manufacture the body. SUMMARY

[0005] The present application aims at solving the above problems in the prior art, and provides a contact box to solve the problem of short service life.

[0006] The object of the present application can be achieved by the following technical scheme:

[0007] The contact box comprises a body with a cylindrical shape and an open lower end, and a high-voltage shielding net embedded in the body and shaped to match the inner cavity of the body. The side of the body is integrally formed with a protrusion, and the protrusion is provided with a wire outlet communicating with the inner cavity of the body. The side of the high-voltage shielding net is provided with a clearance communicating with the wire outlet. The feature of the contact box is that the side of the high-voltage shielding net is fixedly connected with an extended shielding cover at the clearance. The extended shielding cover is embedded in the protrusion. The extended shielding cover is trumpet-shaped and gradually narrows in the direction of the wire outlet extending into the inner cavity of the body.

[0008] During installation, the contact box is fixed in the cabinet of a switch cabinet. The busbar extends into the inner cavity of the body from the wire outlet for fixation. The remaining conductive components extend into the body from the open lower end of the body and match the busbar. Since the high-voltage shielding net is shaped to match the inner cavity of the body, the fixed position of the busbar in the inner cavity of the body is located inside the high-voltage shielding net. Thus, when the contact box is in operation, the high-voltage shielding net can eliminate the discharge phenomenon in the inner cavity of the body, thereby reducing the partial discharge and making the internal electric field more uniform. In addition, the high-voltage shielding net is provided with the protruding extended shielding cover at the clearance. The extended shielding cover is embedded in the protrusion. The extended shielding cover can eliminate the discharge phenomenon caused by the small air gap between the busbar and the inner wall of the protrusion. Moreover, since the extended shielding cover is trumpet-shaped and gradually narrows in the direction of the wire outlet extending into the inner cavity of the body, the distance between the end of the extended shielding cover and the inner wall of the protrusion can be maximized, and the insulation thickness is increased, thereby avoiding the discharge and breakdown of the inner wall of the protrusion due to burrs at the end of the extended shielding cover, and ensuring the insulation performance. Through the above arrangement, the contact box improves the shielding effect and ensures the insulation performance, thereby prolonging the service life of the contact box.

[0009] In the above contact box, the wire outlet is a square port, and the extended shielding cover is square.

[0010] The wire outlet is a square port, and the extended shielding cover is square. The shape of the extended shielding cover matches the shape of the busbar, so that the busbar at the wire outlet can be covered by the extended shielding cover as much as possible, and the shielding effect at this position is better, thereby ensuring the insulation performance and prolonging the service life of the contact box.

[0011] In the above contact box, the extended shielding cover comprises a pair of shielding pieces one and a pair of shielding pieces two. The two shielding pieces one are both inclined and gradually narrow in the direction of the wire outlet extending into the inner cavity of the body. The two shielding pieces two are both inclined and gradually narrow in the direction of the wire outlet extending into the inner cavity of the body.

[0012] The two shielding pieces one are both arranged obliquely and the distance between the two shielding pieces one gradually reduces along the direction of the wire outlet extending into the inner cavity of the body, the two shielding pieces two are both arranged obliquely and the distance between the two shielding pieces two gradually reduces along the direction of the wire outlet extending into the inner cavity of the body, so that the whole extension shielding cover is trumpet-shaped, the thickness of the insulation layer gradually increases along the direction of the wire outlet extending out of the inner cavity of the body, and the tip discharge at the end of the extension shielding cover is avoided to prevent the inner wall of the protrusion from being broken and the insulation performance is affected.

[0013] In the above-mentioned contact box, each shielding piece one and the two adjacent shielding pieces two are both circularly arc transition.

[0014] Each shielding piece one and the two adjacent shielding pieces two are both circularly arc transition, so that the sharp angle at the connection is avoided to cause the discharge phenomenon, and the service life of the contact box is further prolonged.

[0015] In the above-mentioned contact box, the high-voltage shielding net is made of conductive nylon by injection molding, and the extension shielding cover and the high-voltage shielding net are integrated.

[0016] Through the design of the mold, the high-voltage shielding net with the extension shielding cover can be directly injection molded by conductive nylon. The two are integrated, the integrity is better, the tip discharge phenomenon is less likely to occur, the service life of the contact box is ensured, the production cost is lower, and the quality is lighter.

[0017] The metal cannot directly manufacture the high-voltage shielding net with the extension shielding cover, and can only be separately manufactured and then welded into a whole, so that the welding part is easy to increase the probability of tip discharge.

[0018] In the above-mentioned contact box, the end edge of the extension shielding cover has an outwardly protruding thickening part, the surface of the thickening part is a circular arc surface, and the thickening part and the inner surface and the outer surface of the end part of the extension shielding cover are both circularly arc transition.

[0019] The surface of the thickening part is a circular arc surface, and the thickening part and the inner surface and the outer surface of the end part of the extension shielding cover are both circularly arc transition, so that there is no sharp part at the end part of the extension shielding cover, and the discharge phenomenon is further eliminated.

[0020] In the above-mentioned contact box, the upper part of the inner cavity of the body is a working section, the length of the high-voltage shielding net is the same as the length of the working section, or the length of the high-voltage shielding net is greater than the length of the working section.

[0021] The upper part of the inner cavity of the body is a working section, the conductive cooperation of each part is located in the working section, the length of the high-voltage shielding net is the same as the length of the working section, or the length of the high-voltage shielding net is greater than the length of the working section, so that the high-voltage shielding net completely covers the electrical connection of each part to achieve full shielding, and local discharge in the inner cavity of the body is avoided to affect the service life of the contact box.

[0022] In the contact box, the body is externally provided with a square boss, the square boss is located below the protruding part, a plurality of metal inserts I with internal screw holes are embedded in the lower surface of the square boss, a grounding shielding ring is embedded in the body corresponding to the position of the square boss, the lower end of the high-voltage shielding net is located inside the grounding shielding ring, a plurality of strip-shaped metal connecting pieces are integrally connected to the outer circumferential surface of the grounding shielding ring, and each metal insert I is fixed to the end of the corresponding metal connecting piece.

[0023] Through the setting of the grounding shielding ring, the discharge phenomenon at the connection position of the body and the switch cabinet mounting plate can be shielded and eliminated, and the service life of the contact box is further prolonged.

[0024] In the contact box, the body is integrally formed with the high-voltage shielding net and the grounding shielding ring by an epoxy resin pouring method.

[0025] In the contact box, the body is integrally formed with the high-voltage shielding net and the grounding shielding ring by an epoxy resin pouring method.

[0026] In use, the contact box is fixed in the cabinet body of the switch cabinet, and the contact box and the cabinet body of the switch cabinet have two fixed positions, one of which is fixed by cooperation of the fastener and the metal insert I, and the other of which is fixed by cooperation of the fastener and the metal insert II. The two fixed positions make the connection between the contact box and the cabinet body of the switch cabinet more firm, and the upper end does not hang in the air, so that the center of gravity is more stable and the stress points are more dispersed.

[0027] Compared with the prior art, the contact box has the following advantages:

[0028] 1. The high-voltage shielding net is shaped to cooperate with the inner cavity of the body, which can eliminate the discharge phenomenon inside the body, thereby reducing the partial discharge amount and making the internal electric field more uniform.

[0029] 2. The high-voltage shielding net is provided with a protruding extension shielding cover at the position of the clearance, the extension shielding cover is embedded in the protruding part, and the extension shielding cover can eliminate the discharge phenomenon caused by the small air gap between the busbar and the inner wall of the protruding part.

[0030] 3. The extension shielding cover is trumpet-shaped and gradually reduces in size in the direction of extending into the inner cavity of the body along the outlet port, which can maximize the distance between the end of the extension shielding cover and the inner wall of the protruding part, increase the insulation thickness, and thus avoid discharge and breakdown of the inner wall of the protruding part due to burrs at the end of the extension shielding cover, and ensure the insulation performance.

[0031] 4. By eliminating the discharge phenomenon and increasing the insulation thickness, the service life is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a schematic view of the contact box embodiment one.

[0033] Figure 2 is another angle schematic view of the contact box embodiment one.

[0034] Figure 3 is a vertical sectional view of the contact box embodiment one.

[0035] Figure 4 is a horizontal sectional view of the contact box embodiment one.

[0036] Figure 5 is a schematic view of the high voltage shielding net in the contact box.

[0037] Figure 6 is a schematic view of the grounding shielding ring in the contact box.

[0038] Figure 7 is a horizontal sectional view of the contact box embodiment two.

[0039] Figure 8 is a horizontal sectional view of the contact box embodiment three.

[0040] In the figure, 1, the body; 1a, the protruding part; 1a1, the outlet; 1b, the square boss; 1c, the concave cavity; 1d, the support part; 1e, the creepage umbrella skirt; 1f, the protection part; 2, the high voltage shielding net; 2a, the gap; 3, the extended shielding cover; 3a, the shielding sheet one; 3b, the shielding sheet two; 3c, the thickened part; 4, the metal mounting block; 5, the fastening screw; 6, the protection part; 7, the connecting hole; 8, the metal insert one; 9, the grounding shielding ring; 10, the metal connecting sheet; 11, the metal insert two. DETAILED DESCRIPTION

[0041] The following are specific embodiments of the present application and further describe the technical solutions of the present application in conjunction with the drawings, but the present application is not limited to these embodiments.

[0042] Embodiment one

[0043] As Figures 1-4As shown, the contact box comprises a body 1 which is cylindrical and open at the lower end, and a high-voltage shielding net 2 embedded in the wall of the body 1 and shaped to match the inner cavity of the body 1. A metal mounting block 4 is fixed at the top wall of the inner cavity of the body 1, the lower surface of the metal mounting block 4 is provided with an internally threaded mounting hole, and the upper end surface of the metal mounting block 4 is provided with a connector embedded in the top wall of the body 1 and penetrating through the top of the high-voltage shielding net 2. The metal mounting block 4 is fixed with the high-voltage shielding net 2 by means of fastening screws 5 which penetrate through the top wall of the high-voltage shielding net 2 and into the metal mounting block 4. The side of the body 1 is integrally formed with a protruding portion 1a, and the protruding portion 1a is provided with a wire outlet 1a1 which communicates with the inner cavity of the body 1. In this embodiment, the wire outlet 1a1 is perpendicular to the axis of the body 1, and the upper end side of the high-voltage shielding net 2 is provided with a clearance opening 2a corresponding to the wire outlet 1a1. The side of the body 1 is also integrally formed with a protective portion 1f which is arranged in the same direction as the protruding portion 1a. The protruding portion 1a is located inside the protective portion 1f and the protective portion 1f extends out of the protruding portion 1a, and there is a gap between the protruding portion 1a and the protective portion 1f. The upper part of the inner cavity of the body 1 is a working section, and the length of the high-voltage shielding net 2 is the same as or greater than the length of the working section.

[0044] As shown in Figure 3 , Figure 4 and Figure 5 , the high-voltage shielding net 2 is specifically cylindrical and open at the lower end. The side of the high-voltage shielding net 2 is fixedly connected with an extended shielding cover 3 at the clearance opening 2a, the extended shielding cover 3 is embedded in the protruding portion 1a, the wire outlet 1a1 is a square opening, the extended shielding cover 3 is also square, the extended shielding cover 3 is trumpet-shaped and gradually narrows in the direction of the wire outlet 1a1 extending into the inner cavity of the body 1. The extended shielding cover 3 and the high-voltage shielding net 2 are of an integral structure, and coupling holes 7 are provided through the high-voltage shielding net 2 and the extended shielding cover 3. The cross section of the extended shielding cover 3 in the vertical direction is square, and the extended shielding cover 3 comprises a pair of shielding pieces one 3a and a pair of shielding pieces two 3b. Both the shielding pieces one 3a and the shielding pieces two 3b are fixedly connected with the high-voltage shielding net 2. The two shielding pieces one 3a are both arranged obliquely, and the distance between the two shielding pieces one 3a gradually narrows in the direction of the wire outlet 1a1 extending into the inner cavity of the body 1. The two shielding pieces two 3b are also both arranged obliquely, and the distance between the two shielding pieces two 3b gradually narrows in the direction of the wire outlet 1a1 extending into the inner cavity of the body 1. The shielding piece one 3a and the adjacent shielding piece two 3b are transitioned by a circular arc. Further, the end edge of the extended shielding cover 3 has a thickened portion 3c which protrudes outward, the surface of the thickened portion 3c is a circular arc surface, and the thickened portion 3c and the inner and outer surfaces of the end of the extended shielding cover 3 are all transitioned by a circular arc. In this way, there is no sharp part at the end of the extended shielding cover 3, and the discharge phenomenon is further eliminated.

[0045] As Figure 1 , Figure 2 and Figure 6 shown, the body 1 outside is provided with a square boss 1b, which is an integral structure with the body 1, and is located below the protruding part 1a. A plurality of metal inserts 8 with internal threads are embedded on the lower surface of the square boss 1b near the four corners. A grounding shield ring 9 is embedded in the body 1 corresponding to the position of the square boss 1b, and the lower end of the high-voltage shielding net 2 is located inside the grounding shield ring 9. Four strip-shaped metal connecting pieces 10 are integrally connected to the outer circumferential surface of the grounding shield ring 9, and the top of each metal insert 8 is fixed to the lower side of the end of the corresponding metal connecting piece 10 (specifically, it can be fixed by welding).

[0046] Further, as Figure 1 and Figure 2 shown, the outer side of the lower end of the body 1 and the outer side near the upper end of the body 1 are both provided with a creepage umbrella skirt 1e, and the high-voltage shielding net 2 is located between the two creepage umbrella skirts 1e. The top of the body 1 has a concave cavity 1c, and the bottom wall of the concave cavity 1c has a convexity. The body 1 is integrally formed with a support part 1d on the side opposite to the protruding part 1a, and at least one metal insert 11 with an internal threaded hole is embedded on the side of the support part 1d away from the body 1.

[0047] The high-voltage shielding net 2 and the grounding shield ring 9 are both made of conductive material. The metal mounting block 4 and the high-voltage shielding net 2 are fixed together, each metal insert 8 and the grounding shield ring 9 are fixed together, and then the two and the metal insert 11 are placed in a mold. Then pour liquid epoxy resin into the mold, and after cooling, the body 1 with the high-voltage shielding net 2, the grounding shield ring 9, the metal insert 8 and the metal insert 11 embedded inside is formed. In use, the contact box is fixed in the cabinet of the switch cabinet, and the contact box and the cabinet of the switch cabinet have two fixing positions, one is fixed by cooperating the fastener with the metal insert 8, and the other is fixed by cooperating the fastener with the metal insert 11. The two fixing positions make the connection between the contact box and the cabinet of the switch cabinet more firm, and the upper end does not hang in the air, so that the center of gravity is more stable and the stress point is more dispersed.

[0048] The busbar extends into the inner cavity of the body 1 from the outlet 1a1 and is fixed to the metal mounting block 4 by fasteners, and the remaining components are extended into the inner cavity of the body 1 from the opening at the lower end of the body 1 to form a fit. The upper part of the inner cavity of the body 1 is a working section, and the conductive fit of each component is located in the working section. The length of the high-voltage shielding net 2 is the same as or greater than the length of the working section, so that the high-voltage shielding net 2 completely covers the electrical connections of each component to achieve full shielding and avoid partial discharge in the inner cavity of the body 1. At the same time, the protruding extension shielding cover 3 is arranged on the high-voltage shielding net 2 at the accommodation opening 2a, and the extension shielding cover 3 is embedded in the protruding portion 1a. The extension shielding cover 3 can eliminate the discharge phenomenon caused by the small air gap between the busbar and the inner wall of the protruding portion 1a.

[0049] Embodiment Two

[0050] The structure and principle of this embodiment are basically the same as those of Embodiment One, except that, as shown in FIG. 2, the outlet 1a1 is inclined to one side relative to the axis of the body 1 in the horizontal direction. Figure 7

[0051] Embodiment Three

[0052] The structure and principle of this embodiment are basically the same as those of Embodiment One, except that, as shown in FIG. 3, the outlet 1a1 is inclined to the other side relative to the axis of the body 1 in the horizontal direction. Figure 8

[0053] The specific embodiments described herein are merely illustrative of the spirit of the present application. Those skilled in the art of the present application can make various modifications or supplements to the described specific embodiments or replace them with similar ways, without deviating from the spirit of the present application or exceeding the scope defined by the appended claims.​​

Claims

1. A contact box, comprising a body (1) in the shape of a cylinder with an open lower end and a high-voltage shielding net (2) embedded in the body (1) and shaped to fit the inner cavity of the body (1), the side of the body (1) being integrally formed with a protrusion (1a) provided with a wire outlet (1a1) in communication with the inner cavity of the body (1), and the side of the high-voltage shielding net (2) being provided with a clearance opening (2a) in communication with the wire outlet (1a1), characterized in that, The high-voltage shielding net (2) is fixedly connected with an extension shielding cover (3) at the side of the displacement opening (2a), the extension shielding cover (3) protrudes from the outer side of the high-voltage shielding net (2), the extension shielding cover (3) is embedded in the protruding part (1a), the extension shielding cover (3) is trumpet-shaped and gradually reduces in size along the direction of the wire outlet (1a1) extending into the inner cavity of the body (1), and the distance between the extension shielding cover (3) and the inner wall of the protruding part (1a) gradually reduces along the direction of the wire outlet (1a1) extending into the inner cavity of the body (1).

2. The contact box of claim 1, wherein, The wire outlet (1a1) is a square opening, and the extension shielding cover (3) is square.

3. The contact box of claim 2, wherein, The extension shielding cover (3) comprises a pair of shielding sheets one (3a) and a pair of shielding sheets two (3b), the two shielding sheets one (3a) are both arranged obliquely, the distance between the two shielding sheets one (3a) gradually reduces along the direction of the wire outlet (1a1) extending into the inner cavity of the body (1), the two shielding sheets two (3b) are both arranged obliquely, and the distance between the two shielding sheets two (3b) gradually reduces along the direction of the wire outlet (1a1) extending into the inner cavity of the body (1).

4. The contact box of claim 3, wherein, Each shielding sheet one (3a) and the adjacent two shielding sheets two (3b) are in arc transition.

5. The contact box according to claim 1 or 2 or 3 or 4, characterized in that, The high-voltage shielding net (2) is made of conductive nylon by injection molding, and the extension shielding cover (3) and the high-voltage shielding net (2) are in an integrated structure.

6. The contact cartridge of claim 5, wherein, The end edge of the extension shielding cover (3) has an outwardly protruding thickened part (3c), the surface of the thickened part (3c) is a circular arc surface, and the thickened part (3c) and the inner and outer surfaces of the end of the extension shielding cover (3) are in arc transition.

7. The contact cartridge of claim 1, wherein, The upper part of the inner cavity of the body (1) is a working section, the length of the high-voltage shielding net (2) is the same as the length of the working section, or the length of the high-voltage shielding net (2) is greater than the length of the working section.

8. The contact cartridge of claim 7, wherein, The outer side of the body (1) is provided with a square boss (1b), the square boss (1b) is located below the protruding part (1a), the lower surface of the square boss (1b) is embedded with a plurality of metal inserts one (8) with internal threaded holes, the body (1) is embedded with a grounding shielding ring (9) at the position corresponding to the square boss (1b), the lower end of the high-voltage shielding net (2) is located on the inner side of the grounding shielding ring (9), the outer circumferential surface of the grounding shielding ring (9) is integrally connected with a plurality of strip-shaped metal connecting pieces (10), and each metal insert one (8) is fixedly connected to the end of the corresponding metal connecting piece (10).

9. The contact cartridge of claim 8, wherein, The body (1) is integrally formed with the high-voltage shielding net (2) and the grounding shielding ring (9) by an epoxy resin pouring method.

10. The contact cartridge of claim 1, wherein, The upper end side of the body (1) is further integrally formed with a supporting part (1d), the supporting part (1d) is arranged opposite to the protruding part (1a), and at least one metal insert two (11) with an internal threaded hole is embedded on the side surface of the supporting part (1d) away from the body (1).

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