Electrical interruption switching element with a tubular or rod-shaped compression area with a varying cross-sectional diameter

Abstract

An example electrical interruption switch includes a casing, surrounding a contact unit defining a current path therethrough. The contact unit has a first and second connection contact, a separation region and an upsetting region. A current supplied to the contact unit via the first connection contact, can be discharged via the second connection contact, or vice versa. The contact unit includes, or is connected to, a sabot configured to move from a starting to an end position via pressure; in the end position, the separation region is separated causing an insulation spacing between the first and second connection contacts. The upsetting region, upset during movement of the sabot from the starting to end positions, is formed as a tubular or rod-shaped element having an axis; the tubular or rod-shaped element has one or more tapers in its cross-sectional diameter; and the cross-sectional diameter is defined perpendicular to the axis.

Claims

1. An electrical interruption switch for interrupting high currents at high voltages, the electrical interruption switch comprising: a casing surrounding a contact unit defining a current path through the electrical interruption switch, the contact unit having a first connection contact, a second connection contact, a separation region and an upsetting region, the contact unit configured to receive a current supplied to the contact unit via the first connection contact; and discharge the current therefrom via the second connection contact, or vice versa, the contact unit including a sabot, or is connected to the sabot, the sabot configured to move from a starting position into an end position by exposure to pressure, wherein in the end position of the sabot, the separation region is separated and an insulation spacing between the first connection contact and the second connection contact is achieved, the upsetting region configured to upset during movement of the sabot from the starting position into the end position, the upsetting region formed as a tubular or rod-shaped element, an axial direction an extent of which runs along an axis X, wherein the tubular or rod-shaped element has one or more tapers in a cross-sectional surface area along the axis X, wherein the cross-sectional surface area is perpendicular to the axis X, and wherein a taper of the upsetting region has a region of a minimum cross-sectional surface area which increases in a direction towards two end regions of the upsetting region.

2. The electrical interruption switch according to claim 1, wherein the tubular or rod-shaped element merges, at two opposite end regions, into respective flanges which extend in a direction of the casing and perpendicular to the axis X.

3. The electrical interruption switch according to claim 1, wherein an increase in the cross-sectional surface area runs mirror-symmetrically in the direction of the end regions, wherein a mirror plane is arranged in the region of the minimum cross-sectional surface area perpendicular to the axis X.

4. The electrical interruption switch according to claim 1, wherein the upsetting region has several tapers, such that the region of the minimum cross-sectional surface area alternates periodically with regions of maximum cross-sectional surface area.

5. The electrical interruption switch according to claim 1, wherein at least one chamber in the electrical interruption switch, which is at least partially delimited by the separation region, is filled with an extinguishing agent, such that the separation region is in contact with the extinguishing agent.

6. The electrical interruption switch according to claim 5, wherein the separation region, the sabot and the extinguishing agent are formed such that the separation region is separable into at least two parts through a supplied current when a threshold amperage is exceeded, wherein an electric arc forming between the two parts of the separation region vaporizes the extinguishing agent, such that a gas pressure to which the sabot is exposed forms, wherein the sabot is moved and the upsetting region is upset.

7. The electrical interruption switch according to claim 1, wherein the interruption switch comprises an activatable material, arranged such that, when the activatable material is ignited, the separation region is exposed to a gas pressure or shock wave generated by the activatable material, such that the separation region is torn open, caved in or separated, the sabot is moved and the upsetting region is upset.

Description

(1) The invention is explained in more detail below with reference to the embodiments represented in the drawings. All individual features described in the figures can—provided this is technically possible—also be used independently of each other in an interruption switch according to the invention.

(2) FIGS. 1A and 1B show schematic views of an interruption switch according to the invention respectively before and after the upsetting region is upset (conducting position), which is present in the form of a rod-shaped element with several tapers in its cross-sectional diameter.

(3) FIGS. 2 to 8 show sections of a contact unit of an interruption switch according to the invention in the upsetting region with different shapes of the tapers in the cross-sectional diameter.

(4) The embodiment represented in FIGS. 1A and 1B of an interruption switch 1 according to the invention comprises a casing 2, in which a contact unit 3 is arranged, which extends through the entire casing 2, and comprises the connection contacts 4 and 5, the separation region 6, the upsetting region 12 and the flanges 13 and 14. The casing 2 is formed such that it withstands a pressure, generated inside the casing 2, which is generated for example in the case of a pyrotechnic tripping of the interruption switch 1, without there being the danger of damage or even bursting. The casing 2 can consist in particular of a suitable material, preferably steel. In the embodiment example represented, the contact unit 3 is formed as a switch tube that can be depressed by the sabot 9 in the upsetting region 12, with the result that it is formed as a tube in the separation 6 and upsetting 12 regions. In the embodiment example represented, the contact unit 3 has a first connection contact 4. Adjoining the first connection contact 4 is a flange 14 extending radially outwards, which is braced on an annular insulator element, which consists of an insulating material, for example a plastic, such that the contact unit 3 cannot be moved out of the casing 2 in the axial direction. The contact unit 3 has an upsetting region 12 adjoining the flange in the axis of the contact unit 3. In the upsetting region 12, which has a predetermined axial extent, the wall thickness of the contact unit 3 is chosen and matched to the material such that, when the interruption switch 1 is tripped as a result of a plastic deformation of the contact unit 3 in the upsetting region 12, the upsetting region 12 is shortened in the axial direction by a predetermined distance.

(5) Adjoining the upsetting region 12 in the axial direction of the contact unit 3 is a flange 13, on which a sabot 9 sits in the embodiment example represented. The sabot 9 is formed as an electrically insulating element, for example a suitable plastic, preferably made of ceramic. This surrounds the contact unit 3 such that an insulating region of the sabot 9 engages between the outer circumference of the flange 13 and the inner wall of the casing 2. If a pressure acts on the surface of the sabot 9, a force F is generated which compresses the upsetting region 12 of the contact unit 3 via the flange 13. This force F is chosen such that, during the tripping operation of the interruption switch 1, an upsetting of the upsetting region 12 occurs, wherein the sabot 9 is moved from its starting position (as seen in FIG. 1B, status before the interruption switch 1 is tripped=conducting position) into an end position (as seen in FIG. 1B, after the switching operation has been completed=separating position).

(6) As can be seen from FIGS. 1A and 1B, the sabot 9 can be chosen such that its external diameter corresponds substantially to the internal diameter of the casing 2, with the result that an axial guidance of the flange 13 and thus also an axially guided upsetting movement during the switching operation is achieved.

(7) After the pressing operation the lugs of the insulator element and of the sabot 9 located close to the casing 2 overlap completely, as seen in FIG. 1B, with the result that the upsetting region 12 pushed together in a meandering fashion after the tripping and the upsetting region 12 is completely surrounded by electrically insulating materials.

(8) Adjoining the sabot 9 or the flange 13 of the contact unit 3 is a separation region 6. The second connection contact 5 then adjoins this side of the contact unit 3.

(9) In the embodiment example represented the sabot 9 is pushed onto the contact unit 3 from the side of the connection contact 5 during the assembly of the interruption switch 1. For this purpose it is split (not drawn). If the second connection contact 5 is not split or if it is in one piece like the contact unit 3, as drawn, the sabot 9 must either be injection-molded or be designed in several parts, in order to be able to install it.

(10) In the axial end of the contact unit 3 in the region of the second connection contact 5 an activatable material 10 can be provided, here often also housed in a mini detonator or a priming screw (drive). Electrical connection lines for the drive can be guided outwards through an opening in the interior of the contact unit 3. The drive is preferably provided in a chamber 7 inside the tubular element of the separation region 6. A further chamber 8 is located between the outer wall of a separation region 6 and the casing 2.

(11) The separation region 6 is dimensioned such that it tears open at least partially, but preferably tears open completely, through the gas pressure generated or the shock wave generated by a drive, with the result that the pressure or the shock wave can also propagate out of the chamber 7 into the outer chamber 8 preferably designed as a surrounding annular space. In this way the chambers 7 and 8 are connected to each other to form one volume. The internal pressure required for upsetting the contact unit 3 can also be generated such that in the case of a particular threshold amperage the separation region 6 melts open and an electric arc forms in between, which vaporizes an extinguishing agent located in the chambers 7 and/or 8. To facilitate the tearing open, the wall of the contact unit 3 in the separation region 6 can also have one or more openings or holes and/or grooves (not shown in FIGS. 1A and 1B). It is to be ensured here that the material of the separation region 6 disconnects the operating current well, thus does not become too hot taking into account heat dissipation, in order that the material cannot be aged too quickly or too much.

(12) When the interruption switch 1 is activated, a pressure or even a shock wave is thus generated on the side of the sabot 9 facing away from the upsetting region 12, whereby the sabot 9 is exposed to a corresponding axial force. This force is chosen through a suitable dimensioning of the activatable material 10 such that in the upsetting region 12 the contact unit 3 is plastically deformed or caved in, but not torn open, and the sabot 9 is then moved in the direction of the first connection contact 4. The activatable material 10 is dimensioned such that, after the separation region 6 has been broken open or caved in, the movement of the sabot 9 moves the two separation halves sufficiently far away from each other, in cooperation with the vaporization of an extinguishing agent then even into an end position.

(13) Directly after the activatable material 10 has been activated, the separation region 6 is thus at least partially torn open or caved in, preferably completely torn open. If the tearing open or caving in has not already been effected before the start of the axial movement of the sabot 9 over the entire circumference of the separation region 6, a residual remainder of the separation region 6, which causes another electrical contact, is completely torn open by the axial movement of the sabot 9, intensified by the very rapid heating then occurring here of the residual cross section of the conductor, which is then only small here, due to the high electric current flowing here.

(14) The interruption switch 1 according to FIGS. 1A and 1B is in principle constructed exactly like the interruption switch of DE 10 2017 123 021 A1 shown in FIG. 1, with the difference according to the invention that the upsetting region 12 does not represent a tubular element with a continuously identical wall thickness, but the tubular element has several tapers in its cross-sectional diameter in a region between the flange-side end regions. The tapers repeat periodically in FIGS. 1A and 1B. In addition, the tapers are rounded, namely preferably such that the surface of the tubular element forms a sinusoidal course in cross section along the axis X.

(15) FIGS. 2 to 8 show in each case a partial region of a contact unit 3, in which the upsetting region 12 and the flanges 13 and 14 adjoining it are present. The upsetting region 12 is formed as a tubular element in FIGS. 2, 3 and 5 to 8 and as a rod-shaped element in FIG. 4. The length L is the extent of the upsetting region 12 in the direction of the axis X. The upsetting region 12 has a region with minimum cross-sectional surface area (surface area which is delimited by the outer circumference of the tubular element), which increases in each case in the direction of the flange-side end regions, i.e. towards the flanges 13 and 14. The radii R1 and R2 represent the radii of the cross-section transitions between the upsetting region 12 and the adjoining flanges 13 and 14. The radii R3 to R5 represent the radii of the cross-section transitions in the region of the minimum cross-sectional surface area(s) to the regions of the increasing cross-sectional surface area(s). The force F acts on the upsetting region 12 during movement of the sabot 9. The angles w1-w4 indicate the gradient of the increase of the cross-sectional surface area relative to the axis X.

(16) FIG. 2 shows an upsetting region 12 with only a minimum cross-sectional surface area. Here the increase in the cross-sectional surface area is also effected uniformly in the direction of both flange-side ends of the upsetting region 12. The angles w1 and w2 here are therefore equally large, in order thus to achieve as uniform as possible an upsetting, which would not be achieved in the case of angles not equally large.

(17) FIG. 3 shows an upsetting region 12, which runs conically from one flange-side end to the other flange-side end. The region of the minimum cross-sectional surface area is located adjacent to the flange 13.

(18) FIGS. 4 and 5 show embodiments with several regions with minimum cross-sectional surface area. In between there are regions with maximum cross-sectional surface area. The increase and decrease in the cross-sectional surface areas between these regions run in a zigzag manner here.

(19) The shown changes in the cross-sectional surface areas are chosen in order to allow the length L of the upsetting region to become longer or to be able to use it before the upsetting region would not upset, but would buckle, due to the pressure load, which would be entirely undesired here:

(20) Corresponding to Euler buckling case 4 (both ends of the buckling rod clamped tightly and pressure load on the rod), the critical buckling load here is calculated as F.sub.crit=4*pi.sup.2/L.sup.2*E*I with the clamped length L, the modulus of elasticity of the rod material E and the axial moment of inertia I of the rod cross section. If the critical buckling load is reached, the rod here would buckle in the middle, in the case of hollow bodies would bulge—which is entirely undesired here and is to be safely prevented, because a contact of the disconnecting switch against the casing would thus short-circuit and bypass an insulator.

(21) On the other hand, as long as possible an upsetting length L is desired in order to be able to convert as much as possible of the energy introduced into the assembly/disconnecting switch plastically.

(22) Through the shown changes in the cross-sectional surface areas in the upsetting region, effectively the available upsetting length L is divided into several smaller upsetting stretches, the upsetting regions of which are then predefined by the cross-sectional changes.

(23) The above-described operations apply analogously to all upsetting bodies, regardless of whether their cross section is completely filled (here only kinking occurs) or whether a tube-like upsetting element is present (here kinking and bulging can occur).

(24) As shown in FIG. 6, the region of the minimum cross-sectional surface area can also be cylindrical in a length t and only then merge into the regions of the increase or decrease in the cross-sectional surface area.

(25) As shown in FIGS. 7 and 8, the surface of the upsetting region 12 can also run in the shape of a concertina. In FIG. 7 the outer surface of the upsetting region 12 runs in a wavy manner and the inner surface is flat. FIG. 8 shows an embodiment in which both inner and outer surfaces have a wavy course, in this case with sine curves running parallel.

LIST OF REFERENCE NUMBERS

(26) 1 interruption switch 2 casing 3 contact unit 4 first connection contact 5 second connection contact 6 separation region 7 chamber 8 further chamber 9 sabot 10 activatable material 12 upsetting region 13 flange on the upsetting region for exposure to pressure by sabot 14 flange on the upsetting region L length of the extent of the upsetting region in the direction of the axis X R1-R5 radii of the cross-section transitions t length of the cylindrical regions with minimum wall thickness in the upsetting region w1-w4 angles of the linear increase in the wall thickness X axis X z length of the cylindrical region with minimum wall thickness in the separation region F force, due to exposure to pressure by sabot