阅读说明：本技术 具有横截面直径可变的管状或杆状镦压区的电断路开关件 (Electrical disconnect switch with tubular or rod-shaped upset region of variable cross-sectional diameter ) 是由 P·莱尔 于 2020-02-20 设计创作，主要内容包括：本发明涉及具有横截面直径可变的管状或杆状镦压区的电断路开关件。它具有壳体,壳体包围限定经过断路开关件的电流路径的触点单元。触点单元具有第一和第二连接触点、分离区和镦压区。触点单元经由第一连接触点可被供应电流并可经由第二连接触点自此输出电流,或反之。触点单元具有推进反射器或与推进反射器连接。推进反射器通过施加压力可从初始位置运动到最终位置,在推进反射器的最终位置中分离区被分断开并获得在第一和第二连接触点之间的绝缘距离。镦压区被设计成其在推进反射器从初始位置运动至最终位置时被镦压。镦压区设计成管状件或杆状件,其轴向延伸方向沿轴线X延伸,管状件或杆状件在垂直于轴线X来限定的横截面直径上具有一个或多个缩窄部。(The invention relates to a circuit breaker having a tubular or rod-shaped upset region with a variable cross-sectional diameter. It has a housing which encloses a contact unit which defines a current path through the disconnection switch. The contact unit has first and second connection contacts, a separation region, and an upset region. The contact unit can be supplied with current via the first connecting contact and can output current therefrom via the second connecting contact, or vice versa. The contact unit has or is connected to a push reflector. The push-on reflector can be moved from an initial position into a final position by applying pressure, in which final position the separation zone is broken and the insulation distance between the first and second connection contacts is obtained. The upsetting zone is designed such that it is upset when the pushing reflector is moved from the initial position to the final position. The upsetting zone is designed as a tubular or rod-shaped element, the axial extension of which extends along the axis X, the tubular or rod-shaped element having one or more constrictions in a cross-sectional diameter defined perpendicular to the axis X.)

1. A circuit breaker (1), in particular for breaking large currents at high voltages,

(a) the electrical disconnection switch has a housing (2) which encloses a contact unit (3) which defines a current path through the disconnection switch (1), and

(b) wherein the contact unit (3) has a first connecting contact (4) and a second connecting contact (5), a separating region (6) and an upsetting region (12),

(c) wherein the contact unit (3) is designed such that it can take up current via the first connecting contact (4) and can carry current away from the contact unit via the second connecting contact (5), or vice versa,

(d) wherein the contact unit (3) has or is connected to a push reflector (9) which is designed such that it can be moved from an initial position into a final position by applying pressure, wherein in the final position of the push reflector the separation zone (6) is broken and an insulation distance between the first connection contact (4) and the second connection contact (5) is obtained,

(e) wherein the upsetting press zone (12) is designed such that it is upset when the pushing ram moves from the initial position to the final position,

it is characterized in that the utility model is characterized in that,

(f) the upsetting zone (12) is designed as a tubular or rod-shaped element, the axial extension direction of which extends along an axis (X), wherein the tubular or rod-shaped element has one or more constrictions in its cross section along the axis (X), wherein the cross section is perpendicular to the axis (X).

2. The circuit breaker element (1) according to claim 1, wherein the tubular or rod-shaped element in its two opposite end regions respectively merges into a flange (13,14) which extends in the direction of the housing (2) and perpendicularly to the axis (X).

3. The disconnector (1) of claim 1 or 2, wherein the upsetting zone (12) has a minimum cross-sectional area at the narrowing, which increases towards both end areas of the upsetting zone (12).

4. A disconnection switch (1) according to claim 3, wherein the progression of the cross-section extends in a mirror-symmetrical manner in the direction of the end region, wherein a mirror plane is arranged in the smallest cross-sectional region perpendicular to the axis X.

5. The disconnection switch (1) according to claim 3 or 4, wherein the upsetting zone (12) has a plurality of constrictions so that the minimum cross-sectional area periodically alternates with the maximum cross-sectional area.

6. The circuit breaker (1) of any of claims 1 to 5 wherein at least one chamber (7) within said circuit breaker (1) is filled with a fire extinguishing agent such that said separation area (6) contacts said fire extinguishing agent, said at least one chamber being at least partially delimited by said separation area (6).

7. The disconnection switch (1) according to any of claims 1 to 6, wherein the disconnection switch (1) comprises an activatable material (10) which is arranged such that, upon ignition of the activatable material (10), the disconnection region (6) is subjected to a gas pressure or a shock wave generated by the activatable material (10), so that the disconnection region (6) is torn, pressed or severed, the push reflector (9) moves and the upsetting pressure region (12) is upset.

8. A circuit breaker (1) according to claim 6 or 7, wherein the separation region (6), the push reflector (9) and the extinguishing agent are designed such that the separation region (6) can be divided into at least two parts by means of a supplied current when a threshold current intensity is exceeded, wherein an arc occurring between the two parts of the separation region (6) vaporizes the extinguishing agent so that a gas pressure applied to the push reflector (9) occurs, wherein the push reflector (9) moves and the upsetting zone (12) is upset.

Technical Field

The invention relates to a circuit breaker, in particular for breaking large currents at high voltages.

Background

Such circuit breakers are used, for example, in power plant technology and KFZ technology, for example in the usual machine and electrical systems of switchgear cabinets for machines and devices, such as in the electric range in electric and hybrid vehicles, but also in electric helicopters and aircraft in emergency situations for the regulated and rapid disconnection of high-current circuits. The requirement for such a switching element is that no hot gases, particles, lumps or plasma are thereby produced. In addition, the overall switching element should ensure insulation resistance after opening.

Other fields of application are the electrical isolation of components from the onboard power supply for short-circuit situations in the relevant components, for example in vertical electrical heating devices or in electric brakes, and the emergency shut-off of lithium batteries, as they have hitherto been used in electric and hybrid vehicles and aircraft. The battery has a terminal voltage of up to 1200 v at a very low internal resistance, while the structural volume is small. Both of these result in a possible short-circuit current of up to 5000 a, sometimes and temporarily even up to 30 ka, in which case there is no significant breakdown of the source voltage, which may have led to the battery igniting or its explosion after a few seconds. The disconnection device proposed here is also well suited for emergency disconnection of individual solar modules or of the entire solar field in the event of an emergency, since it can be designed to be controllable or can be controlled remotely.

All the applications described here are generally dc-switched off, which, unlike ac-current, does not have a zero crossing. Normally, only the operating voltage is applied to the disconnection switch. However, at the moment when the dc circuit is broken in the disconnection switch, the breakdown of the magnetic field of the external current circuit causes the voltage to rise so significantly that an arc generally occurs between the two separate terminals of a disconnection element. In order to generate an arc, a relatively high voltage is generally required. But already much lower voltage is sufficient for sustaining, which is generally the case at the usual operating voltage of about 450 volts.

In order to extinguish the arc also after the voltage peak has dropped to the operating voltage, switching pieces have been used which have a contact tube which conducts the current and has a separating region in the form of a hollow cylinder which is completely split, melted or broken along its cross section in order to open the circuit and which mechanically move the two ends of the cylinder away from one another. For the purpose of splitting or breaking the hollow cylinder, an activatable drive element is usually used, which is located in the hollow space of the hollow cylinder. Furthermore, such circuit breakers usually comprise push-in reflectors (Treibspiegel) for moving the separating ends of the separating zones away from one another. At this point, the pushing reflector must upset the upset region (Stauchbereich) of the contact tube. In general, the upsetting press zone is also referred to as tubular or hollow cylinder and must fold well during upsetting. However, it is established that the upsetting zone often breaks during rapid movement of the thrust reflector and upsetting of the upsetting zone and at the same time the housing may be in impermissibly electrically conductive contact, in which case the insulation of the separated connecting elements may be bridged.

Disclosure of Invention

In view of the prior art, the invention is based on the object of providing a disconnection switch, in particular for interrupting a high direct current at high voltage, in which material of the upsetting zone is prevented from breaking when the contact is transferred from the conducting position into the disconnection position, so that no fragments short the separated component contacts, which are then electrically insulated from the housing, toward the housing.

The invention relates to a circuit breaker switch element which is particularly suitable for breaking large currents at high voltages. It has a housing which encloses a contact unit which defines a current path through the disconnection switch. The contact unit has first and second connection contacts, a separation region and an upset region. The contact unit is designed such that it can receive current via the first connecting contact and can output current therefrom via the second connecting contact, or vice versa. The contact unit has or is connected to a push reflector. The push-on reflector is designed such that it can be moved from an initial position into a final position by applying pressure, wherein in the final position of the push-on reflector the separation zone is broken and an insulation distance between the first and second connection contacts is obtained. The upset region is designed such that it is upset when the push reflector is moved from the initial position to the final position.

The trip switch according to the invention is characterized in that the upset region is designed as a tubular or rod-shaped element, the axial extension of which extends along an axis X, wherein the cross section of the tubular or rod-shaped element has one or more constrictions along the axis X, wherein the cross section is perpendicular to the axis X.

By means of the one or more constrictions, unlike a cross section which remains constant along the axis X, a bursting of the upsetting zone fragments can be largely avoided when transitioning from the conducting position into the separating position, so that the separated contacts of the disconnecting switch are not conductively contacted with respect to the housing. As a result, the upset region is not largely torn off, but rather folds of the upset region occur without the formation of harmful fragments.

In one embodiment of the invention, the tubular or rod-shaped element preferably merges at its two opposite end regions into a flange which extends toward the housing and perpendicularly to the axis X. The flange serves to enable a force to be applied to the upset region in the direction of the axis X from the pushing reflector, i.e. the upset region can be upset.

The cross-section of the rod-like or tubular element may have any shape, e.g. circular, oval, any circle with or without one or more corners, triangular, quadrangular, pentagonal, hexagonal or polygonal, wherein a circular cross-section is preferred. It is a tubular member and therefore one would prefer a circular cross-section rather than a circular cross-section.

By cross-sectional narrowing is meant here that the cross-section is smaller in the region of the upset region than in the adjoining region (in the direction of the axis X). The upsetting zone has a minimum cross-sectional area at the narrowing, which preferably increases towards the two end areas of the upsetting zone.

The cross-sectional progression may be continuous or discontinuous in the axial extension of the rod-shaped or tubular element, i.e. stepped, for example, wherein a continuous progression is preferred. The successive increments may be made linearly or progressively. Preferably, the cross section increases conically towards the end region of the rod-shaped or tubular element. It is also preferred that the rod-like or tubular member is designed so that it has a cross section of the same shape (with varying area dimensions) in any plane perpendicular to the axis X. Furthermore, the increase in cross-section in both directions towards the end region of the rod-or tube-like element may be different or identical, i.e. extend in a mirror-symmetrical manner, where the mirror plane is arranged perpendicular to the axis X in the smallest cross-sectional area. It is also preferred that the cross-sectional transitions up to the respective end region of the rod or tube extend radially, i.e. with a defined radius, in order to avoid excessive notch stresses here, which could undesirably break the rod or tube at said points, in particular under mechanical or vibrational loading of the component or connection.

In one embodiment of the invention, it is preferred that the upset region has a plurality of constrictions, the smallest cross-sectional area alternating with the largest cross-sectional area preferably periodically. In this case, the upset region can be designed on the surface in a zigzag, stepped or accordion bellows shape. The latter is preferred when the upset region is designed as a tubular member.

The smallest cross-sectional area of the rod-like or tubular element can be formed in the form of an area with a constant cross-section. In this case, it is preferred that the cross-sectional transition from the region with the smallest cross-section to the region with increasing cross-section extends radially, i.e. with a certain radius. In one embodiment, such regions with a constant cross section, i.e. a plurality of cross-sectional increasing regions which adjoin one another in the smallest cross-sectional area, preferably also with radially extending cross-sectional transitions, can also be dispensed with.

In one design, the circuit breaker of the present invention has at least one chamber at least partially defined by a separation zone. The at least one chamber is preferably filled with a fire extinguishing agentThereby allowing the separation zone to contact the fire extinguishing agent. The at least one chamber is preferably outside the separation zone cavity, preferably in the form of a tubular member, i.e. the at least one chamber is surrounded by the separation zone. In addition, the inventive circuit breaker can have a further chamber which adjoins the outer region of the tubular element of the separation region. In other words, the tubular member delimits the at least one chamber from the other chamber. The further chamber is preferably delimited at its outer periphery by the housing of the disconnection switch element. The further chamber is also preferably filled with a fire extinguishing agent.

However, it is also possible to dispense with filling the cavity of the tubular element of the separation region, in which case only the other chamber outside the tubular connection is filled with extinguishing medium. However, even in the case of very small currents to be switched off, which are associated with very low circuit inductances, the extinguishing agent can be dispensed with completely, the surrounding air then being sufficient for the separation process.

The extinguishing agent may be a solid, powdered or fluid medium. The extinguishing agent is preferably a vaporizable or vaporizable medium (e.g., boric acid, powder is directly transformed from a powder phase to a gas under the influence of an electric arc, where it absorbs energy and thus depletes the electric arc). The extinguishing agent is preferably a fluid medium which completely or partially changes into the gaseous state when the boiling or gasification temperature is reached. It is also preferred that the extinguishing agent also has good electrical insulating properties so that the arc can be extinguished after the two separate parts of the separation zone are sufficiently far apart, there then being sufficient insulation between the separate contacts for the subsequent undesired flow of current there through. The fire extinguishing agent is preferably an oil with or without a thickener such as silicone oil, or a silane or polysiloxane such as hexasilane or pentasilane with as little or better no carbon atom weight.

The push-on reflector has the task, in the inventive circuit breaker, of separating the two separate parts of the separating area from one another by means of a mechanical movement which is carried out by the application of pressure and which separates one part of the separating area from the other part of the separating area. In this way, a safe distance is established between the two separate parts of the separation zone.

The tripping of the circuit breaker element according to the invention, i.e. the tripping of the transition from the on position to the off position, can take place in a passive or active manner.

If the tripping of the inventive circuit breaker is to be carried out actively, it is preferred that the circuit breaker contains an activatable material. The activatable material is preferably arranged such that, upon ignition of the pyrotechnic material, the separation region is subjected to a gas pressure or shock wave generated by the activatable material, thereby causing the separation region to crack, crush or break, advancing the reflector and the upsetting pressure region to be upset. The pushing reflector is preferably designed such that, when the activatable material is ignited, it is subjected to the gas pressure or shock wave generated thereby in such a way that the pushing reflector moves in the housing in a direction of movement from the initial position into the final position, with the detachment zone being split, pressed or broken.

The activatable material may be a pyrotechnic material that acts as a detonation or deflagration. The pyrotechnic material is present in the circuit-breaking switching element according to the invention, preferably a so-called mini-detonator or primer or a cake igniter, but can also be incorporated in other forms.

If the triggering of the inventive circuit breaker should take place passively, i.e. without the need for an activatable material for the initial breaking of the separation zone, it is preferred that the separation zone, the push reflector and the extinguishing agent are designed such that they can be divided into at least two parts by supplying an electric current above a threshold current intensity as a result of heating at or above the melting point of the connecting piece material, wherein an arc occurring between the two parts of the separation zone vaporizes the extinguishing agent, so that a gas pressure is present which is applied to the push reflector, wherein the push reflector moves and the upset zone is upset.

Furthermore, the separation zone can also have one or more theoretical breaking points, which can be in the form of constrictions, incisions, slots or holes. The theoretical breaking point is preferably in the form of a hole through the tubular member of the separation zone. In this way, the aperture connects the at least one chamber with another chamber. In this way, it is easy to fill the at least one chamber inside the tubular element with extinguishing agent when manufacturing the circuit breaker element according to the invention.

The design of the upsetting zone according to the invention is advantageous or of great significance in particular when using materials for the upsetting zone, the ductility of which is not as good as E-copper, which is generally used here. For example, in order to produce aluminum as a material for the connecting element, it is necessary to use hard aluminum, which will break into many small pieces immediately during the folding process, even after the connecting element has been softened and annealed after its manufacture.

According to one embodiment of the invention, the upset region is preferably designed as a tubular element. The cavity within the tubular member is referred to herein as the additional chamber. The further chamber of the upsetting zone can be completely filled with extinguishing agent. In this case, it is preferred that a communication means in the form of a channel is present between the further chamber and the at least one chamber. By the movement of the propelling reflector and/or the upsetting process of the upsetting zone, the volume of the further chamber is reduced such that the extinguishing agent is sprayed through the passage between the at least two portions of the separation zone. As a result, the extinguishing medium can be pressed from the other chambers into the other chambers during the upsetting operation via the channel and the electric arc which may still be present at the separation region is prevented or further effectively cooled. At the same time, the extinguishing agent, which may have already partially decomposed in the at least one chamber, is diluted by the newly inflowing extinguishing agent, thus also improving the "in-arm" insulating properties of the extinguishing agent. It may also be preferred in this design of the invention that only one chamber and also the other chamber and the associated channel are filled with fire extinguishing agent. It may be preferred here that the further chamber is not filled with extinguishing agent.

The features of the inventive disconnecting switch device shown in the preceding embodiments can be combined with one another according to the invention as long as they are not mutually exclusive.

Drawings

The present invention will be described in detail with reference to the embodiments shown in the drawings. All individual features shown in the figures can be used independently of one another in the circuit breaker according to the invention as long as they are technically possible.

Fig. 1 shows a schematic representation of the inventive circuit breaker before the beginning of the upset region (conducting position), which is in the form of a rod-shaped element with a plurality of constrictions in its cross-sectional diameter,

fig. 2 to 8 show a detail of a contact unit of the inventive circuit breaker in an upsetting zone, the cross-sectional diameter of which has a different narrowing.

List of reference numerals

1 breaking switch

2 casing

3 contact unit

4 first connection point

5 second connection contact

6 separation area

7 chamber

8 another chamber

9 push reflector

10 activatable material

12 upset zone

13 flanges on the upset region for applying pressure by pushing on the reflector

14 flanges on the upset region

L-shaped upset area extension in X-axis direction

Radius of transition region of R1-R5 cross section

T length of cylindrical zone with minimum wall thickness in upset zone

Angle of linear increasing wall thickness of w1-w4

X axis X

Z length of the cylindrical zone with minimum wall thickness in the separation zone

F force, determined by the pressure exerted by the propelling reflector

Detailed Description

The embodiment of the circuit breaker 1 according to the invention shown in fig. 1 comprises a housing 2 in which a contact unit 3 is arranged, which extends through the entire housing 2 and comprises connecting contacts 4, 5, a separating region 6, a contact region 12 and flanges 13, 14. The housing 2 is designed such that it is able to absorb the pressure occurring in the housing 2, which pressure occurs, for example, when the pyrotechnic triggering of the circuit breaker 1 occurs, without the risk of damage or even cracking. The housing 2 can be made of a suitable material, preferably steel. The contact unit 3 is designed in the embodiment shown in the form of a switching tube which can be pressed by the push-in reflector 9 in the upsetting region 12, so that it is designed in the form of a tube in the separating region 6 and the upsetting region 12. The contact unit 3 is provided with a first connection point 4 in the embodiment shown. A radially outwardly extending flange 14, which is supported on an annular insulating part made of an insulating material, such as plastic, is connected to the first connection point 4, so that the contact unit 3 cannot be axially displaced out of the housing 2. The contact unit 3 has an upset region 12 which meets the flange on the axis of the contact unit 3. The wall thickness of the contact unit 3 in the upset region 12 with the predetermined axial extent is selected and matched to the material in such a way that, when the disconnection switch 1 is triggered by plastic deformation of the contact unit 3 in the upset region 12, the upset region 12 is shortened by a predetermined distance in the axial direction.

In the axial direction of the contact unit 3, a flange 13, on which the push-on reflector 9 rests in the embodiment shown, adjoins the upsetting zone 12. The push reflector 9 is designed as an electrically insulating element, for example made of a suitable plastic, preferably a ceramic material. It surrounds the contact unit 3 in such a way that the insulating region of the push-on reflector 9 is inserted between the outer circumferential surface of the collar 13 and the inner wall of the housing 2. If a pressure is applied to the surface of the push reflector 9, a force F is generated which compresses the upsetting zone 12 of the contact unit 3 by the flange 13. The force F is selected such that during the triggering of the disconnecting switch 1, a pressure is applied to the pressure-increasing region 12, wherein the push-in reflector 9 is moved from its initial position (switched-on position before the tripping of the disconnecting switch 1) into a final position (switched-off position after the switching process has ended).

As shown in fig. 1, the push-in reflector 9 can be selected such that its outer diameter corresponds substantially to the inner diameter of the housing 2, so that an axially guided and thus also an axially guided upsetting movement of the flange 13 is obtained during the switching process.

After the pressing process, the insulation and the projection of the pushing reflector 9 close to the housing 2 are completely staggered, so that the folded-up upset region 12, which is folded in a meandering manner after the triggering and upsetting processes, is completely surrounded by the electrically insulating material.

The separation area 6 is connected to the pushing reflector 9 or the flange 13 of the contact unit 3. The second connecting contact 5 then meets the contact unit 3 on this side.

In the exemplary embodiment shown, the push-in reflector 9 is pushed onto the contact unit 3 from the side of the connecting contact 5 when the disconnecting switch 1 is installed. It is separated for this purpose (not shown). If the second connecting contact 5 is not separated or, as shown, is integral with the contact unit 3, the push-on reflector 9 must be injected or designed in multiple parts in order to be able to be mounted.

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, which is usually also mounted in a miniature detonator or a firing screw (drive element). The electrical connection lines for the drive element can be guided outwards by means of recesses in the interior of the contact unit 3. The drive member is preferably arranged in a chamber 7 in the tubular member of the separation zone 6. Another chamber 8 is located between the outer wall of the separation zone 6 and the housing 2.

The separation zone 6 is dimensioned such that it is at least partially broken, but preferably completely broken, by the generated driving gas pressure or the generated driving shock wave, so that said pressure or shock wave can also propagate from the chamber 7 into the outer chamber 8, preferably in the form of a surrounding annular cavity. The chambers 7, 8 are in this way interconnected to form a volume. The internal pressure required for the contact unit 3 to be upset can also be generated in such a way that, at a certain threshold current level, the separation zone 6 melts and an electric arc is generated between the two, which vaporizes the extinguishing agent located in the chambers 7 and/or 8. The wall of the contact unit 3 in the separation zone 6 may also have one or more indentations or holes and/or grooves (not shown in fig. 1) in order to facilitate cracking. In this case, it is ensured that the material of the separating zone 6 switches off the drive current well, i.e. not so hot that the material does not age rapidly or so strongly, taking into account the heat dissipation.

That is, when the interrupter switch 1 is activated, a pressure or even a shock wave is generated on the side of the push-in reflector 9 facing away from the upset region 12, as a result of which the push-in reflector 9 is subjected to a corresponding axial force. The force is selected by appropriately dimensioning the activatable material 10 such that the contact unit 3 in the upset region 12 is plastically deformed or pressed in, but not split, and subsequently the push-in reflector 9 is moved towards the first connecting point 4. The activatable material 10 is dimensioned here such that, after the detachment zone 6 has been broken or pressed in, the movement of the push reflector 9 separates the two severing halves sufficiently far apart from one another so that, in cooperation with the evaporation of the extinguishing agent, they reach even a final position.

That is, the separation region 6 is at least partially cracked or compressed, preferably completely cracked, immediately after activation of the activatable material 10. If the cracking or pressing-in does not take place over the entire extent of the separating region 6 before the axial movement of the push reflector 9 begins, the remaining part of the separating region 6 which is still in conductive contact is completely broken by the axial movement of the push reflector 9, and the very rapid heating which then occurs here is intensified by the remaining cross section of the conductor which is only then reduced by the high currents flowing there.

The disconnecting switch 1 according to fig. 1 has in principle the same structure as the disconnecting switch of DE102017123021a1, as shown in fig. 1, with the difference according to the invention that the upset region 12 is not a tubular part with a continuously uniform wall thickness, but rather the cross-sectional diameter of the tubular part has a plurality of constrictions in the region between the flange-side ends. In fig. 1, the narrowing is periodically repeated. Furthermore, the narrowing is rounded, preferably such that the surface of the tubular element forms a sinusoidal curve in cross section along the axis X.

Fig. 2 to 8 each show a partial region of the contact unit 3 in which the upsetting region 12 and the adjoining flanges 13,14 are present. The upsetting zone 12 is designed as a tubular piece in fig. 2, 3 and 5 to 8 and as a rod-shaped piece in fig. 4. The length L is the extension of the upset region 12 in the direction of the axis X. The upsetting zone 12 comprises a zone of minimum cross-section (the area is delimited by the outer circumferential surface of the tubular element) which increases towards the flange-side ends, i.e. the flanges 13,14, respectively. Radii R1 and R2 are the radii of the cross-sectional transitions between the upset region 12 and the associated flanges 13, 14. Radii R3-R5 are radii at the transition of the cross-section from the smallest cross-sectional area to the increasing cross-sectional area. The force F acts on the upsetting zone 12 when advancing the movement of the reflector 9. The angles w1-w4 illustrate the increasing inclination of the cross-section with respect to the axis X.

Figure 2 shows an upset region 12 having only a minimal cross-section. The increase in cross section is likewise effected here toward the two flange-side ends of the upsetting zone 12. In this case, angles w1 and w2 are therefore equally large, in order to obtain as much as possible an upset which would not be obtained with angles of different sizes.

Fig. 3 shows an upsetting press region 12 which extends conically from one flange-side end toward the other. The smallest cross-sectional area adjoins the flange 13.

Fig. 4 and 5 show embodiments with a plurality of zones having a minimum cross section. The area with the largest cross-section is located between them. The cross-sectional area between these regions increases and decreases in a zigzag manner.

The cross-sectional change shown is selected so that the length L of the upsetting press zone, which is not upset by the pressure load but which is subsequently bent, can be increased or utilized, which is completely undesirable here:

according to the fourth Euler buckling condition (buckling bars clamped at both ends and applying a compressive load to the bars), here with respect to F_krit＝4*pi²/L²E I the critical buckling load is calculated, the clamping length at this time is L, the modulus of elasticity of the rod material is E and the axial plane moment of inertia of the rod cross section is I. When a critical buckling load is reached, the rod bends centrally here, bulging if it is a hollow body, which is completely undesirable here and should be reliably avoided, so that the contacts of the disconnector are short-circuited towards the housing and will surround the insulation.

On the other hand, it is desirable to have as large a upset length L as possible in order to be able to plastically transform as much energy as possible to be input into the assembly/disconnect switch.

The usable upsetting length L is approximately divided into a plurality of smaller upsetting distances by the illustrated cross-sectional change in the upsetting zone, which is then predetermined by the cross-sectional change.

In the sense of this, the above procedure applies to all upsets, whether they are completely filled in cross section (here only buckling occurs) or whether tube-like upsets are present (here buckling and bulging can occur).

As shown in fig. 6, the minimum cross-sectional area can also be cylindrical over the length t and only then transition to an increasing or decreasing cross-sectional area.

As shown in fig. 7 and 8, the surface of the upsetting zone 12 may also extend in an accordion bellows type. In fig. 7, the outer surface of the upset region 12 is undulating in course and the inner surface is planar in course. Fig. 8 shows an embodiment in which both the inner and the outer surface have a wave-like course, in this case with sinusoidal curves running in parallel.