Insulating body, housing of a vacuum switching tube and vacuum switching tube

Abstract

The invention relates to an insulating body (1 to 12) made of an electrically insulating material and having an end face (20) with a metallization (22) for joining the insulating body (1 to 12) to another object by means of a soldered connection. Only a central region of the end face (20) is metallized and / or the surface of the end face (20) is not planar and / or the surface of a section (32) of the insulating body (1 to 12) adjoining the end face (20) is curved, wherein the end face (20) has a tongue (26) for a tongue-and-groove connection and the metallization (22) is arranged on the tongue (26).

Description

[0001] The invention relates to an insulating body, a housing of a vacuum switching tube and a vacuum switching tube.

[0002] A vacuum switching tube, such as that known from EP 0 563 830 A1, comprises a housing and two contact elements movable relative to each other. Typically, one contact element is a fixed contact that is rigidly connected to the housing, and the other contact element is a movable contact that is movable relative to the fixed contact between a first switching position, in which the movable contact touches the fixed contact, and a second switching position, in which the movable contact and the fixed contact are spaced apart.

[0003] The housing of a vacuum interrupter typically includes at least one insulating element made of an electrically insulating material, such as a ceramic or glass, and shaped like a tube around a longitudinal axis of the housing. An insulating element in the form of an insulating disc for cooling electrical components is known, for example, from WO 93 / 10 560 A1.

[0004] To connect an insulating body to another component of the vacuum interrupter, such as another insulating body or an electrically conductive section of the housing, the contact surface where the insulating body is joined to the other component is typically metallized to allow soldering. This soldered connection creates a gas-tight seal between the insulating body and the other component. The contact surface is usually the surface of an end face of the insulating body.

[0005] Soldering creates so-called "triple points" at the edges of the metallization, where three different media meet. In this case, these media are, for example, the electrically conductive material of the metallization and two insulators: the material from which the insulating body is made, and the vacuum inside the housing (at the inner edge of the metallization) or the medium surrounding the housing, usually air (at the outer edge of the metallization). Since the two insulators have different dielectric constants, electric field lines are forced out of the insulator with the higher dielectric constant, in this case the insulating body, and toward the insulator with the lower dielectric constant, in this case the vacuum or the medium surrounding the vacuum tube.If no countermeasures are taken, this will result in increased electric field strength in the areas of the triple points, which can lead to a reduced dielectric performance of the insulators.

[0006] To counteract the increased electric field strength in areas around triple points, these points are electrically shielded, for example, by metal screens or other electrically conductive shielding materials, thus relieving the electrical load in these areas. Alternatively or additionally, the vacuum and / or the medium surrounding the vacuum interrupter are replaced, at least in the vicinity of triple points, by a medium with a higher dielectric constant.

[0007] The invention is based on the objective of providing an improved insulating body with a metallization, an improved housing of a vacuum switching tube with such an insulating body and an improved vacuum switching tube with such a housing, wherein the improvement in each case relates in particular to the electrical load of the environment of triple points that arise from the metallization.

[0008] The object is achieved according to the invention by an insulating body with the features of claim 1, a housing of a vacuum switching tube with the features of claim 10 and a vacuum switching tube with the features of claim 11.

[0009] Advantageous embodiments of the invention are the subject of the dependent claims.

[0010] An insulating body according to the invention is made of an electrically insulating material and has an end face that has a metallization for the metallurgical connection of the insulating body to another object by means of a soldered joint. Only a central area of ​​the end face is metallized and / or the surface of the end face is not planar and / or the surface of a section of the insulating body adjoining the end face is curved.

[0011] By metallizing only a central area of ​​the insulating body's end face, triple points at the edges of the end face are avoided; that is, the triple points are shifted from the edges of the end face to less exposed areas. A non-planar design of the end face and / or a curved design of a section of the insulating body adjoining the end face impedes the movement of charge carriers from the metallization to objects or media connected to the insulating body. All these features reduce the negative effects of triple points on electric fields in the vicinity of the triple points through the design of the insulating body, thus reducing or completely eliminating the need for further design measures to mitigate these effects, such as electrically conductive elements for shielding the triple points.

[0012] In one embodiment of an insulating body according to the invention, the end face has two grooves between which the metallization is arranged. The grooves advantageously act as barriers to the movement of charge carriers from the metallization to objects connected to the insulating body.

[0013] In a further embodiment of an insulating body according to the invention, the end face has a groove in which the metallization is arranged. By arranging the metallization in a groove in the end face, the groove also advantageously acts as a barrier to the movement of charge carriers from the metallization to an object or medium connected to the insulating body. The groove can also be advantageously used for positioning the insulating body by means of a tongue-and-groove connection with another object.

[0014] In an insulating body according to the invention, the end face has a spring for a tongue-and-groove connection, and the metallization is arranged on the spring. Due to the arrangement of the metallization on the spring, the spring also advantageously acts as a barrier for the movement of charge carriers from the metallization to an object or medium connected to the insulating body and can also be advantageously used for positioning the insulating body by means of the tongue-and-groove connection with another object.

[0015] In a further embodiment of an insulating body according to the invention, the end face has several steps, and the metallization is arranged on one of these steps. The stepped design of the end face also hinders the movement of charge carriers from the metallization to an object or medium connected to the insulating body. Furthermore, the stepped design of the end face can also be used to position the insulating body relative to another object.

[0016] In a further embodiment of an insulating body according to the invention, the section of the insulating body adjoining the end face has at least one groove that runs equidistant from the end face. For example, the metallization extends up to this groove. In this embodiment of an insulating body according to the invention, the section of the insulating body adjoining the end face is also used to reduce the negative effects of triple points on electric fields in the vicinity of the triple points. A groove in the section of the insulating body adjoining the end face impedes the movement of charge carriers from the metallization to an object or medium connected to the insulating body. Extending the metallization up to this groove avoids spatial concentrations of the electric field and thus increases in the electric field strength in the vicinity of triple points.

[0017] In a further embodiment of an insulating body according to the invention, the section of the insulating body adjoining the end face tapers from the end face outwards. This taper also impedes the movement of charge carriers from the metallization.

[0018] In a further embodiment of an insulating body according to the invention, the insulating body is made of a ceramic material or glass.

[0019] In a further embodiment of an insulating body according to the invention, the insulating body is essentially designed as a hollow cylinder and the metallization runs in a ring shape around a cylinder axis of the hollow cylinder.

[0020] The two aforementioned embodiments of an insulating body according to the invention are particularly advantageous for the use of the insulating body as a component of a housing of a vacuum switching tube.

[0021] A housing of a vacuum switching tube according to the invention comprises at least one insulating body designed according to the invention.

[0022] A vacuum switching tube according to the invention has a housing designed according to the invention.

[0023] The advantages of a housing for a vacuum switching tube and a vacuum switching tube according to the invention result from the advantages of an insulating body according to the invention mentioned above.

[0024] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of exemplary embodiments, which are explained in more detail in conjunction with the drawings. These drawings show: Fig. 1 a sectional view of a first embodiment of two interconnected insulating bodies, Fig. 2 a sectional view of a second embodiment of two interconnected insulating bodies, Fig. 3 a sectional view of a third embodiment of two interconnected insulating bodies, Fig. 4 a sectional view of a fourth embodiment of two interconnected insulating bodies, Fig. 5 a sectional view of a fifth embodiment of two interconnected insulating bodies, Fig. 6 a sectional view of a sixth embodiment of two interconnected insulating bodies, Fig. 7 a sectional view of a seventh embodiment of two interconnected insulating bodies, Fig. 8 a sectional view of an eighth embodiment of two interconnected insulating bodies, Fig. 9 a sectional view of a ninth embodiment of two interconnected insulating bodies, Fig. 10 a sectional view of a tenth embodiment of two interconnected insulating bodies, Fig. 11 a sectional view of an embodiment of a vacuum switching tube.

[0025] Corresponding parts are marked with the same reference symbols in the figures.

[0026] The Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9 to Fig. Figure 10 shows two insulating bodies 1 to 12 according to exemplary embodiments of the invention. The two insulating bodies 1 to 12 have opposing end faces 20, each of which has a metallization 22. These metallizations 22 are joined together. For example, the metallizations 22 are soldered together by placing solder foil between the metallizations 22 and melting it in an oven. Each insulating body 1 to 12 is designed as a hollow cylinder. Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9 to Fig. Figure 10 each shows a section of a cross-sectional view of insulating bodies 1 to 12 in a section plane in which the cylinder axes of the insulating bodies 1 to 12 lie, the cylinder axes being vertical in the drawing plane and coinciding with each other, and the section showing the insulating bodies 1 to 12 only on one side of the cylinder axes. The insulating bodies 1 to 12 are, for example, each made of a ceramic material or of glass. Each metallization 22 runs in a ring-like pattern around the cylinder axis of the respective insulating body 1 to 12 on the end face 20.

[0027] Fig. 1 ( Fig. Figure 1 shows two identically constructed insulating bodies 1. The end faces 20 of the insulating bodies 1 are flat. The metallization 22 of each end face 20 covers a central area of ​​the end face 20.

[0028] Fig. 2 ( Fig. Figure 2) shows two identical insulating bodies 2. The end face 20 of each insulating body 2 has two grooves 24, between which the metallization 22 is arranged. Each groove 24 extends in a ring-like fashion around the cylindrical axis of the respective insulating body 2.

[0029] Fig. 3 ( Fig. Figure 3 shows two insulating bodies 3, 4 with differently designed end faces 20. The end faces 20 interact as a tongue-and-groove connection, wherein the end face 20 of a first insulating body 3 has a groove 24 and the end face 20 of the second insulating body 4 has a tongue 26 that engages in the groove 24. The metallization 22 of the end face 20 of the first insulating body 3 is arranged in the groove 24. The metallization 22 of the end face 20 of the second insulating body 4 is arranged on the tongue 26.

[0030] Fig. 4 ( Fig. Figure 4) shows two insulating bodies 3, 5 with differently designed end faces 20. As in Fig. 3 The end faces 20 act together as a tongue-and-groove connection, wherein the end face 20 of a first insulating body 3 has a groove 24 and the end face 20 of the second insulating body 5 has a tongue 26 that engages in the groove 24. The metallization 22 of the end face 20 of the first insulating body 3 is arranged in the groove 24. The metallization 22 of the end face 20 of the second insulating body 5 is arranged on the tongue 26. In contrast to Fig. 3 the spring 26 is arranged between two grooves 24 in the end face 20 of the second insulating body 5.

[0031] Fig. 5 ( Fig. Figure 5) shows two insulating bodies 6, 7 with differently designed end faces 20. As in Fig. 3 The end faces 20 act together as a tongue-and-groove connection, wherein the end face 20 of a first insulating body 6 has a groove 24 and the end face 20 of the second insulating body 7 has a tongue 26 that engages in the groove 24. The metallization 22 of the end face 20 of the first insulating body 6 is arranged in the groove 24. The metallization 22 of the end face 20 of the second insulating body 4 is arranged on the tongue 26. In contrast to Fig. 3. The groove 24 and the tongue 26 have round cross-sections instead of square ones. For example, the cross-sections of the groove 24 and the tongue 26 are each semicircular.

[0032] Fig. 6 ( Fig. Figure 6 shows two identical insulating bodies 6. The end face 20 of each insulating body 6 has a groove 24 with a circular cross-section. For example, the cross-section of the groove 24 is semicircular. Each groove 24 is located centrally in the end face 20 of an insulating body 6. The metallization 22 of the end face 20 of each insulating body 6 is located in the groove 24 of this end face 20. The grooves 24 of the end faces 20 of the two insulating bodies 6 form a cavity in which a metal ring 28, for example a copper ring, is located and soldered to the metallizations 22 of both end faces 20. In this case, the metallizations 22 of the two end faces 20 are therefore not directly connected to each other but via the metal ring 28.

[0033] Fig. 7 ( Fig. Figure 7 shows two insulating bodies 8, 9, each having end faces 20 with two corresponding steps 30. Opposing first steps 30 of the two end faces 20 each have a metallization 22.

[0034] Fig. 8 ( Fig. Figure 8 shows two identical insulating bodies 10. A section 32 of each insulating body 10 adjoining the end face 20 tapers from the end face 20.

[0035] Fig. 9 ( Fig. Figure 9 shows two identical insulating bodies 11. A section 32 adjoining the end face 20 of each insulating body 11 is curved, having a groove 34 on both the inside and outside of the insulating body 11, the grooves being equidistant from the end face 20. Each groove 34 has a rounded cross-section.

[0036] Fig. 10 ( Fig. Figure 10 shows two identically constructed insulating bodies 12. The insulating bodies 12 differ from those in Fig. The insulating bodies 11 shown in Figure 9 are distinguished only by the fact that the metallizations 22 extend beyond the end face 20 to the grooves 34 on the inside and outside of the respective insulating body 12.

[0037] Fig. 11 ( Fig. Figure 11 shows a schematic sectional view of an embodiment of a vacuum switching tube 40 according to the invention. The vacuum switching tube 40 comprises an embodiment of a housing 41 of the vacuum switching tube 40 according to the invention and two contact elements 43, 45. The contact elements 43, 45 are positioned relative to each other along a longitudinal axis 47 of the vacuum switching tube 40 between a first switching position, in which they touch each other, and a position in Fig. The second switching position shown in Figure 11, in which they are separated from each other, is movable. The housing 41 comprises a first end section 49, a second end section 51, a middle section 53, and four insulating bodies 1. The end sections 49, 51, and the middle section 53 are each made of metal. The insulating bodies 1 are arranged as shown in Figure 11. Fig. 1 described. Each insulating body 1 is essentially designed as a hollow cylinder whose cylinder axis coincides with the longitudinal axis 47 of the vacuum switching tube 40. Two insulating bodies 1 are arranged between the first end region 49 and the central region 53 and are designed as described in Fig. 1 are connected to each other as described. Furthermore, one of these insulating bodies 1 can be connected to the first end region 49 via a metallization 22, and the other of these insulating bodies 1 can be connected to the central region 53 via a metallization 22. The other two insulating bodies 1 are arranged between the second end region 51 and the central region 53 and are connected as described in Fig. 1 described, interconnected. Furthermore, one of these insulating bodies 1 can be connected analogously to the second end region 51 via a metallization 22, and the other of these insulating bodies 1 can be connected analogously to the central region 53 via a metallization 22. Instead of based on Fig. 1. The described insulating body 1 can have the housing 41 insulating bodies, which, as described by one of the Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9 to Fig.10 are described, executed, and interconnected.

[0038] Although the invention has been further illustrated and described in detail by means of preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived from them by a person skilled in the art.

Claims

Insulating body (1 to 12) made of an electrically insulating material and having an end face (20) which has a metallization (22) for the metallurgical connection of the insulating body (1 to 12) to another object by means of a soldered connection, wherein - only a central area of ​​the end face (20) is metallized and / or - the surface of the end face (20) is not planar and / or - the surface of a section (32) of the insulating body (1 to 12) adjoining the end face (20) is curved, characterized in that the end face (20) has a tongue (26) for a tongue-and-groove connection and the metallization (22) is arranged on the tongue (26). Insulating body (1 to 12) according to claim 1, wherein the end face (20) has two grooves (24) between which the metallization (22) is arranged. Insulating body (1 to 12) according to claim 1 or 2, wherein the end face (20) has a groove (24) in which the metallization (22) is arranged. Insulating body (1 to 12) according to one of the preceding claims, wherein the end face (20) has several steps (30) and the metallization (22) is arranged on one of these steps (30). Insulating body (1 to 12) according to one of the preceding claims, wherein the section (32) of the insulating body (1 to 12) adjoining the end face (20) has at least one groove (34) which extends equidistantly to the end face (20). Insulating body (1 to 12) according to claim 5, wherein the metallization (22) extends to the groove (34). Insulating body (1 to 12) according to one of the preceding claims, wherein the section (32) of the insulating body (1 to 12) adjoining the end face (20) tapers from the end face (20). Insulating body (1 to 12) according to one of the preceding claims, which is made of a ceramic material or glass. Insulating body (1 to 12) according to one of the preceding claims, wherein the insulating body (1 to 12) is essentially designed as a hollow cylinder and the metallization (22) extends in a ring shape around a cylinder axis of the hollow cylinder. Housing (41) of a vacuum switching tube (40) comprising at least one insulating body (1 to 12) designed according to one of the preceding claims. Vacuum switching tube (40) with a housing (41) designed according to claim 10.

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