Single-part shield produced by tensile compressive forming

Abstract

The invention proposes a single-part shield, produced by tensile compressive forming, for tubular insulators in high-voltage technology. The single-part shield according to the invention does not require the production process needed to connect, by hard soldering or welding, the parts in a conventional multi-part shield.

Description

[0001] Description

[0002] One-piece shielding manufactured by tensile compression forming

[0003] The invention relates to a shield for an insulator in high-voltage technology.

[0004] In vacuum interrupters, an insulating section can consist of several interconnected insulators. The insulators are connected to each other by a metal layer at their ends. This metal layer is electrically conductive and is shielded. Furthermore, an insulator can be connected to a metallic part. This contact area is also shielded.

[0005] The shields consist of a flat cylindrical section to which the end faces of the insulators are attached at the top and bottom. At the edge of the cylindrical section, the shield is extended in the axial direction. This forms a thin cylinder or cone, at the end of which is a torus or part of a torus.

[0006] The shielding must act in both the positive and negative axial directions. It must therefore act along the axis of the first insulator as well as along the axis of the second insulator. The shielding is usually manufactured by tensile-compression forming. It is currently made from several parts that must be joined together. This can be done by brazing or welding.

[0007] The invention is based on the problem of providing a shielding for insulators in high-voltage technology which requires less effort than a conventional shielding.

[0008] The problem is solved by a shield having the features of claim 1. The one-piece shield according to the invention eliminates the manufacturing process required for joining the shields by brazing or welding, as opposed to a conventional multi-piece shield. Eliminating the connection point also eliminates the risk of unsuccessful soldering.

[0009] Advantageous further developments of the invention are specified in the subclaims.

[0010] The invention is explained in more detail below as an exemplary embodiment to the extent necessary for understanding, using figures. In the figures:

[0011] Fig. 1 a shielding according to the invention between two insulators,

[0012] Fig. 2 a shield according to the invention between an insulator and a metallic part and

[0013] Fig 3 a conventional two-part shield.

[0014] In the figures, like designations refer to like elements.

[0015] In the conventional shielding in two-part design shown in Fig. 3, there is a first shielding S1 which has a flat, annular section FA1. At the inner edge of section FA1, the shielding is extended by a conical section Kl in the direction of axis A. The end of the conical section Kl facing axis A is adjoined by a torus TI or part of a torus TI such that the cross section of the shielding S1 is approximate to the shape of a question mark “?” and the torus TI does not intersect the plane of section FA1. The first shielding S1 and a second shielding S2 which is identical to it are connected to one another in an opposite manner at their sections FA1 and FA2, which can be achieved, for example, by brazing or welding. Tubular insulators II and I2, respectively, are connected to the surfaces of sections FA1 and FA2 facing away from the connection.In the shield according to the invention in a one-piece design shown in Fig. 1, there is a shield S which has a flat annular section FA. At the inner edge of the section FA, the shield is extended by a conical section K in the direction of the axis A. Adjoining the end of the conical section K facing the axis A is a first surface GF1 which is curved towards the plane of the section FA and is bent around the axis A, has a circular segment-like shape in cross-section and onto which a tubular section RA with a substantially constant diameter is formed. Formed onto the tubular section RA is a second surface GF2 which is curved towards the plane of the section FA, is bent around the axis A and has a circular segment-like shape in cross-section. The loose end of the second curved surface GF2 faces the flat annular section FA in such a way that an open gap SP remains.The conical section K, the first curved surface GF1, the tubular section RA and the second curved surface GF2 form an incompletely closed torus with a circumferential gap SP, the torus extending above and below the plane of the section FA. The axis A of the tubular section RA is intersected at right angles by the plane of the section FA. The plane of the section FA intersects the tubular section RA perpendicularly. The end faces of the tubular insulators II and 12, respectively, which are arranged concentrically to the axis A, are connected to the top and bottom of the section FA.

[0016] In the shielding according to the invention shown in Fig. 2, a shielding S is provided in a one-piece design which is identical to the shielding S from Fig. 1. A tubular insulator I and a metallic part MT are connected to the top and bottom of the section FA and are arranged concentrically to the axis A. The metallic part MT has a smaller wall thickness than the insulator I. The circumferential gap SP in the torus of the shielding S is arranged facing the metallic part MT.

[0017] The shielding S according to the invention is produced from a component, for example, from thin sheet metal, by tensile-compressive forming. In a first forming step, the first torus GF1, or part of a torus, is produced. In a further forming step, the second torus GF2, or part of a torus, is produced.

[0018] The present invention has been explained in detail for illustrative purposes using specific embodiments. Elements of the individual embodiments can also be combined with one another. The invention is therefore not intended to be limited to individual embodiments, but rather to be limited solely by the appended claims.

[0019] Reference symbol list

[0020] A - central axis

[0021] AB - Distance

[0022] FA1 - flat section shielding S 1

[0023] FA2 - flat section shielding S2

[0024] GF1 - first curved surface

[0025] GF2 - second curved surface

[0026] Kl - first cone section

[0027] K2 - second cone section

[0028] I - I insulator

[0029] II - first insulator

[0030] 12 - second insulator

[0031] MT - metallic part

[0032] RA - tubular section

[0033] S - shielding

[0034] 51 - first shielding

[0035] 52 - second shielding

[0036] SP - gap

[0037] TI - Torus 1

[0038] T2 - Torus 2

[0039] + - positive direction of axis A

[0040] - - negative direction of axis A

Claims

Patent claims 1. Shielding for a high-voltage insulator, - a flat annular section (FA) concentric to an axis (A), - on the inner edge of the section (FA) a conical section (K) is formed which is inclined in the positive direction (+) of the axis (A) and towards the axis (A), - a first surface (GF1) is formed on the end of the conical section (K) which is curved in the negative direction of the axis (A) and towards the axis (A), which is bent concentrically around the axis (A) and has a circular segment-like shape in cross-section, - a tubular section (RA) concentric with the axis (A) and having a substantially constant radius relative to the axis (A) is formed on the end of the first curved surface (GF1) facing the axis (A), - at the end of the tubular section (RA) aligned in the negative direction (-) of the axis (A), a second surface (GF2) is formed which is curved in the positive direction (+) of the axis (A) and towards the inner edge of the section (FA), which is bent concentrically around the axis (A) and has a circular segment-like shape in cross-section, - from the axis (A) the radius of the free end of the curved surface (GF2) is smaller than the radius of the inner edge of the section (FA), - the free end of the curved surface (GF2) is at a distance (AB) in the negative direction (-) of the axis (A) from the plane of the section (FA) and - the plane of the section (FA) intersects the tubular section (RA) at right angles.

2. Shielding according to claim 1, characterized in that the flat annular portion (FA) cooperates with the end face of an insulator (I).

3. Shielding according to one of the preceding claims, characterized in that the flat annular portion (FA) cooperates with the end face of a tubular metallic part (MT).

4. Shielding according to one of the preceding claims, characterized in that it is made of thin sheet metal by means of tensile compression forming.

5. Shielding according to claim 1, characterized in that the first curved surface (GF1) is produced in a first forming step and the second curved surface (GF2) is produced in a second forming step.

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