CIRCUIT ARRANGEMENT FOR DISCONNECTING A CONDUCTIVE CONNECTION

Description

[0001] The invention relates to a switching arrangement for disconnecting a current-carrying connection, wherein a secondary contact is located on a fixed contact, the secondary counter-bearing. The secondary contact is arranged at the end of a pivotable secondary contact arm, and pivoting causes the conductive connection to be disconnected.

[0002] Various switching arrangements are known from the prior art in which a pivoting component can be used to disconnect the electrically conductive connection. A known embodiment, on which the invention is based, is known from DE 16 65 510 C3. Another prior art switching arrangement is known from CH-A-341209.

[0003] The disclosed high-voltage switch has a main current path that can rotate about an axis and rests with its free end against a fixed main contact in the current-carrying position. A secondary current path is pivotably mounted on the main current path, with the pivot axis of the secondary current path being arranged slightly offset parallel to the pivot axis of the main current path. In addition to the fixed main contact, there is a fixed secondary contact against which the secondary current path rests in the current-carrying position. For this purpose, a spring is arranged in the bearing of the secondary current path, which causes the contact with the fixed secondary contact. When the main current path is rotated and thus the connection from the fixed main contact is opened, the spring is tensioned because the secondary current path continues to rest against the fixed secondary contact and is thus prevented from performing the same pivoting movement.Shortly before the main current path reaches its end position, the secondary current path slides past the stationary secondary contact, and the tensioned spring pulls the secondary current path back to its previous position relative to the main current path. This interrupts the connection to the stationary secondary contact. This allows for arc-free separation from the main contact during the switching operation. Only then does the stationary secondary contact separate.

[0004] Although the currents conducted via the fixed auxiliary contact during the switching operation are lower and thus the arc occurring during separation is smaller than it would be with a single main switch, each switching operation with the resulting arc leads to damage to the fixed auxiliary contact or the auxiliary current path.

[0005] The object of the present invention is therefore to reduce the occurrence of arcs during the switching process.

[0006] The stated object is achieved by an inventive embodiment of a switching arrangement according to the teaching of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0007] This generic switching arrangement is used to break an electrically conductive connection and comprises a stationary auxiliary counter bearing and a movable auxiliary contact arm. The auxiliary contact arm, in a contact position, rests against the auxiliary counter bearing with a secondary contact located at its free end, thus establishing the current-carrying connection of the switching arrangement.

[0008] The secondary contact arm has a secondary pivot axis at the end opposite the secondary contact, about which the secondary contact arm can pivot. The secondary contact arm is designed to pivot about the secondary pivot axis in a first direction to a limit position, and in the opposite direction back to a rest position, at least starting from a contact position when the secondary contact is in contact with the secondary counter bearing.

[0009] The secondary contact arm is also adjustable transversely to the secondary pivot axis. In this case, it is possible to provide a linear adjustment movement transversely to the secondary pivot axis and, for example, approximately transversely to the extension of the secondary contact arm when the latter is in its initial position. However, it should be emphasized that the adjustability transversely to the secondary pivot axis can also include pivoting in addition to displacement, and the adjustment movement is therefore composed of translation and rotation. The adjustment movement transversely to the secondary pivot axis occurs from an initial position through an intermediate position to a release position.

[0010] It should be ensured that when the auxiliary contact arm is adjusted from the initial position to the intermediate position, it is simultaneously pivoted from the contact position to the limit position. This ensures that the auxiliary contact arm is in the limit position upon reaching the intermediate position. The simultaneous adjustment is achieved by the auxiliary contact resting on the auxiliary counterbearing from the contact position to the limit position. This means that the adjustment movement is not possible without simultaneous pivoting.

[0011] With regard to the positioning of the secondary contact relative to the secondary counter bearing in the initial position, it can be provided, on the one hand, that the secondary contact arm is in the contact position and that contact is made from the secondary contact to the secondary counter bearing.

[0012] Alternatively, the secondary contact can be arranged at a distance from the secondary counter bearing in the home position and thus not in the contact position. In this case, the contact position is reached over a relatively short distance from the home position to the intermediate position. A relatively short distance is assumed to be less than 10% of the distance. In this case, the secondary contact arm is also in the rest position in the home position.

[0013] Upon further adjustment from the intermediate position toward the release position, the secondary contact moves increasingly away from the secondary counterbearing, and the current-carrying contact is interrupted. At the same time, the secondary contact arm pivots back, so that shortly before, with, or shortly after reaching the release position, the secondary contact arm moves into the rest position with the simultaneous pivoting movement around the secondary pivot axis.

[0014] When the secondary contact detaches from the secondary counterbearing in the intermediate / limit position, an arc typically occurs between the secondary contact and the secondary counterbearing (depending on the applied voltages and currents). To reduce this effect or reduce the duration of the arc, the invention provides for a flow element to be arranged on the secondary contact arm, at least in the area of ​​the secondary contact. The flow element is to be designed in such a way that when the secondary contact arm pivots about the secondary pivot axis, an air flow is caused to the free end of the secondary contact and thus to the arc. For this purpose, the flow element represents an air resistance against the pivoting movement, whereby the air displaced by the flow element during pivoting is to be directed accordingly to the end of the secondary contact as far as possible (and, if possible, does not flow above or below the secondary contact at a distance from the free end).

[0015] The inventive arrangement of a flow element on the pivoting secondary contact creates an air flow onto the resulting arc when the connection to the secondary counter bearing is broken, thus extinguishing the arc more quickly. This results in less damage to the switching arrangement than is the case with a generic design. Conversely, this increases the permissible voltage or current during the breaking process, thus expanding the application range of the respective design compared to the generic solution.

[0016] The flow element is intended to direct an air flow to the free end of the secondary contact arm. Therefore, an arrangement is required that is effective in achieving the corresponding air movement, unlike a design without a flow element. In this regard, in a first advantageous embodiment, the flow element is arranged on a side of the secondary contact that lies in the direction of the secondary pivot axis. However, it is particularly advantageous if the flow element is arranged on both sides of the secondary contact in the direction of the secondary pivot axis. In this regard, it is irrelevant whether the flow element is formed by a single component or is constructed in multiple parts.

[0017] Advantageous air displacement during pivoting of the secondary contact arm is achieved if the flow element has a flat and / or blade-like shape on the side facing the secondary counter bearing in the contact position. Consequently, the flow element extends in the longitudinal direction of the secondary contact arm and in the direction of the secondary pivot axis. Thus, when pivoting the secondary contact arm, the air can be advantageously directed in the longitudinal direction of the secondary contact arm to the free end of the secondary contact.

[0018] To ensure the intended current flow from the secondary contact to the secondary counter bearing while avoiding undefined current flows, the flow element is advantageously made of a non-conductive material.

[0019] Furthermore, it is necessary for the flow element to be of sufficient effective size, but not to unnecessarily hinder the pivoting movement due to air resistance. For this purpose, the effective resistance area FS that opposes a pivoting movement is taken into account, i.e. for a rectangular shape, the area formed by the product of the length in the longitudinal direction of the secondary contact arm multiplied by the effective width in the direction of the secondary pivot axis. For this purpose, a secondary arm length LN is considered to be the distance from the secondary pivot axis to the end of the secondary contact. Even though the secondary contact only makes a minor contribution, it is included in the calculation of the effective resistance area FS if the flow element is located in the area of ​​the secondary contact.

[0020] This advantageously results in a resistance area FS according to the formula: FS ≥ 0,0005 * LN * LN .

[0021] In a particularly advantageous manner, the resistance area is at least: FS ≥ 0,001 * LN * LN .

[0022] In contrast, the resistance area should not be larger than: FS ≤ 0,01 * LN * LN .

[0023] In a particularly advantageous manner, the resistance area is at most: FS ≤ 0,04 * LN * LN .

[0024] A flow element of this size represents a particularly advantageous compromise between the desired air flow to the free end of the secondary contact to combat an arc while avoiding unnecessary air resistance to ensure a fast pivoting movement.

[0025] To realize the pivoting movement of the secondary contact arm, the switching assembly features a secondary pivot bearing on which the secondary contact arm is pivotably mounted. The secondary pivot bearing thus defines the secondary pivot axis.

[0026] Typically, the secondary contact arm is designed to pivot back immediately upon exceeding the intermediate position. For this purpose, a clamping device is used, which is tensioned when the secondary contact arm pivots from the contact position to the limit position. If the limit position is exceeded due to the movement beyond the intermediate position, the clamping device causes the secondary contact arm to pivot back.

[0027] The tensioning device can be designed in various ways, with the preferred version being located in and / or on the secondary pivot bearing. For example, a torsion spring can be used.

[0028] In order to be able to make contact again, it is necessary to be able to guide the secondary contact past the secondary counter bearing in the opposite direction. Since it is generally intended that the secondary contact arm cannot be pivoted beyond the rest position, returning the adjustment movement from the released position to the starting position would lead to a collision. It is therefore advantageous to provide a deflection element on the secondary counter bearing. For this purpose, the secondary contact arm must have either an elastic deformation area or an articulated joint, which enables adjustment of the secondary contact in the direction of the secondary pivot axis via the secondary counter bearing. In this respect, a joint axis of the articulated joint must be aligned perpendicular to the secondary pivot axis. The deflection element has the task of guiding the secondary contact over the secondary counter bearing during the movement to the starting position.

[0029] Since the deflection element and the flow element according to the invention are arranged in the region of the secondary contact, it is advantageously provided that the flow element rests on the deflection element in sections upon appropriate adjustment movement, returning to its original position. However, it can also be provided that the flow element is designed such that the secondary contact rests directly on the deflection element.

[0030] To ensure that, at the end of the adjustment movement back to the starting position, the secondary contact does not get stuck on the deflection element without being able to assume the contact position, it is further advantageous if the secondary contact arm can either be adjusted beyond the starting position into an operating position or, alternatively, pivoted beyond the contact position into an end position. In both cases, this allows the secondary contact to return to the contact position after crossing the deflection element in the direction of the secondary pivot axis. In any case, it must be ensured that the main contact maintains reliable contact with the main counterbearing from the operating position to the starting position.

[0031] Although the switchable auxiliary contact could be used as a standalone switching arrangement, the invention provides for a combination of a main contact and the auxiliary contact in a switching arrangement. This advantageous switching arrangement comprises, first of all, a main contact arm, which surrounds the main contact at a free end. At the end opposite the main contact is a main pivot axis, about which the main contact arm can pivot from the initial position through the intermediate position to the free position. The auxiliary pivot axis is arranged parallel to the main pivot axis on the main contact arm and spaced apart from the main pivot axis.

[0032] Accordingly, pivoting the main contact arm leads to a simultaneous adjustment of the secondary contact arm transverse to the secondary pivot axis due to the adjustment of the secondary pivot axis. At the same time, the engagement of the secondary contact with the secondary counterbearing from the contact position to the limit position leads to pivoting around the secondary pivot axis in the opposite direction to the main contact arm.

[0033] In the initial position, the main contact rests against a main counter bearing. The main counter bearing is also fixedly arranged adjacent to the secondary counter bearing. When the main contact arm pivots, the main contact moves away from the main counter bearing. For this purpose, the switching arrangement has, in addition to the secondary counter bearing, a main counter bearing that is also fixed and located adjacent to the secondary counter bearing.

[0034] It is intended that there is already a sufficient distance between the main contact and the main counter bearing when the intermediate position is reached or, with regard to the secondary contact arm, the limit position, so that no arc can occur between the main contact and the main counter bearing.

[0035] A main pivot bearing is used to support the main contact arm, by means of which the main contact arm is pivotably mounted and which thus defines the main pivot axis.

[0036] A particularly advantageous design with regard to the arrangement of the secondary contact arm on the main contact arm is achieved by arranging the secondary pivot bearing on the main contact arm.

[0037] The following figures outline two exemplary circuit configurations. They show: Fig. 1 shows a first embodiment with the switching arrangement in the initial position and intermediate position; Fig. 2 shows the switching arrangement from Fig. 1 in the movement to the intermediate position / limit position; Fig. 3 the switching arrangement from Fig. 1 in the intermediate position / limit position; Fig. 4 the switching arrangement from Fig. 1 in the movement from the intermediate position / limit position to the release / rest position; Fig. 5 the switching arrangement from Fig. 1 in the release / rest position; Fig. 6 the switching arrangement from Fig. 1 in the movement to the operating position; Fig. 7 the switching arrangement from Fig. 1 in the movement to the end position; Fig. 8 shows a second embodiment of the secondary contact with flow element in detail; Fig. 9 shows the second embodiment in the initial position / contact position; Fig. 10 shows the switching arrangement from Fig. 9 in the movement to the intermediate position / limit position; Fig. 11 the switching arrangement from Fig. 9in the intermediate / border position.

[0038] In the Figure 1 The first exemplary embodiment of a pivot arrangement 01 according to the invention is schematically sketched in a plan view in the direction of the secondary pivot axis 22. The main contact arm 11 can be seen, which is pivotally mounted about the main pivot axis 12 by means of the main pivot bearing 13. At the end of the main pivot arm 11 opposite the main pivot axis 12 is a main contact 14. This main contact 14 rests on a fixed main counter bearing 04, and thus this connection establishes the conductive connection intended for the normal case.

[0039] In this illustration, the main contact arm 11 is in the starting position.

[0040] On the main contact arm 11, at a distance from the main pivot axis 12, there is a secondary pivot bearing 23 with the secondary pivot axis 22, which is aligned parallel to the main pivot axis 12 .A secondary pivot arm 21 is connected to the secondary pivot bearing 23 and can pivot about the secondary pivot axis 22. With the connection via the secondary pivot bearing 23 to the main contact arm 11, its pivoting simultaneously leads to a displacement of the secondary pivot bearing 23. At the end of the secondary contact arm 21 opposite the secondary pivot axis 22, a secondary contact 25 is arranged, which 25 rests against a stationary secondary counter bearing 05.

[0041] Furthermore, the secondary contact arm 21 is in the contact position in this illustration.

[0042] Also shown in this view is the arrangement of a clamping device 24 which connects the secondary contact arm 21 to the main contact arm 11.

[0043] Essential for the present invention is the arrangement of a flow element 27 at the secondary contact 25. According to the illustration in Fig. 1the flow element 27 is located above the secondary contact 25 and extends in the direction of the secondary pivot axis 22.

[0044] In the Figure 2 The switching arrangement 01 is now removed from the Fig. 1 sketched in the movement of the main contact arm 11 to the intermediate position. The distance now existing between the main contact 14 and the main counter bearing 04 can be seen. In contrast, the secondary contact 25 remains in constant contact with the secondary counter bearing 05, thus blocking the similar movement of the secondary contact arm 21. As a result, the secondary pivot bearing 23 with the secondary contact arm 21 undergoes a displacement on the main contact arm 11 on the one hand, and pivots around the secondary pivot axis 22 in the opposite direction to the main contact arm 11 on the other. This tensions the clamping device 24.

[0045] In the Figure 3The intermediate position of the main contact arm 11 and thus of the auxiliary pivot bearing 23 is now sketched, in which the auxiliary contact arm 11 is also in the limit position. This represents the transition up to which the auxiliary contact 25 rests on the auxiliary counter bearing 05. Since further pivoting movement of the main contact arm 11 means that the auxiliary contact 25 no longer rests on the auxiliary counter bearing 25, the tensioned tensioning device 24 causes the auxiliary contact arm 21 to be suddenly retracted towards the main contact arm 11, whereby the distance between the auxiliary contact 25 and the auxiliary counter bearing 05 increases at a higher speed than the distance from the main contact 14 to the main counter bearing 04.

[0046] When the contact is released, an arc often occurs between the secondary contact 25 and the secondary counter bearing 25, which must be eliminated or at least reduced. This is achieved with the aid of the flow element, which, with the incipient pivoting movement of the secondary contact arm 11 after leaving the limit position, causes an air flow to the free end of the secondary contact 25. The resulting arc is, so to speak, blown out.

[0047] In the following Figure 4 the swivel arrangement 01 is sketched in the further movement with the main contact arm 11 between the intermediate position and the release position and the secondary contact arm 21 between the limit position and the rest position.

[0048] In the Figure 5 The swivel arrangement 01 is sketched as an example in the free position, which is also the rest position.

[0049] Not shown in this embodiment is the advantageous deflection element, which allows the secondary contact 25 to pass the secondary counter bearing 05 during the pivoting movement back from the release position to the starting position. To ensure that the secondary contact 25 does not get stuck on the deflection element at the end of the movement and thus cannot return to its contact position, the secondary contact is guided beyond the deflection element. For this purpose, Figure 6 An example in which the main contact arm 11 is pivoted further into an operating position. In this respect, it is irrelevant whether the main contact arm 11 is pivoted into the operating position shown here or back into the initial position for the normal state of the power line. In this case, contact between the main contact 14 and the main counter bearing 04 is ensured in any case, regardless of the position of the main contact arm 11. Fig. 6 outlined operating position up to the Fig. 1The starting position is given as shown in the sketch. Alternatively, the Figure 7 a solution in which the secondary contact arm 21 is pivoted further into a deformation.

[0050] In the Figure 8 Now, for a further exemplary embodiment of a switching arrangement 31 according to the invention, the secondary contact 55 with the flow element 57, 58 arranged thereon is formed in this exemplary embodiment by a flow element part 57 arranged on the upper side and a flow element part 58 arranged on the lower side. In this figure, the blade-like shape of the flow element 57, 58 can be advantageously seen, which 57, 58 extends from near the end of the secondary contact 55 to the secondary contact arm 51.

[0051] In the Figure 9The second embodiment of the switching arrangement 31 is now sketched in the initial position or contact position. First of all, the main contact arm 41 can be seen, which is pivotably mounted about the main longitudinal axis 42 via the main pivot bearing 43. Opposite is the main contact 44, which rests on the fixed main counter bearing 34 in the initial position shown here.

[0052] On the main contact arm 41, spaced from the main pivot axis 42, the secondary pivot bearing 53 is arranged with a secondary pivot axis 52 parallel to the main pivot axis 42. The secondary contact arm 51 is attached to the secondary pivot axis 53, which has a joint 56. The axis of the joint 56 is aligned perpendicular to the secondary pivot axis 52 and transverse to the longitudinal extent of the secondary contact arm 51. At the end of the secondary contact arm 51 is the secondary contact 55, on the top and bottom of which the flow element 57, 58 is located as in the previous Figure 8 shown in detail. The secondary contact 55 rests against the stationary secondary counter bearing 35 in the contact position.

[0053] The deflection element 36 is arranged diagonally above the secondary counter bearing 35 opposite the secondary contact 55, over which 36 the secondary contact 55 slides with the part of the flow element 58 arranged on the underside when the arrangement with the main contact arm 41 and the secondary contact arm 51 is pivoted back and is thus guided over the secondary counter bearing 35.

[0054] In the following Figure 10 The switching arrangement 31 is shown in the pivoting movement from the initial position to the intermediate position. Here, the main contact 44 is spaced apart from the main counter bearing 34. In contrast, the secondary contact 55 remains in contact with the secondary counter bearing 35.

[0055] In the Figure 11The switching arrangement 31 is shown in the intermediate position of the main contact arm 41 and thus also in the limit position of the secondary contact arm 51. In this state, the contact of the secondary contact 55 detaches from the secondary counter bearing 35, so that in the subsequent movement, the secondary contact arm 51 is pulled at an accelerated rate toward the main contact arm 41. With the onset of the movement and the arrangement of the flow element 57, 58 on the secondary contact 55, an air flow is caused to the free end of the secondary contact 55. This extinguishes any resulting arc at an accelerated rate.

Claims

1. Switching arrangement (01,31) for disconnecting an electrically conductive connection, having a fixed main counter-bearing (04,34) and having a main pivot bearing (13), which (13) defines a main pivot axis (12,42), and having a main-contact arm (11,41), which (11,41) comprises a main contact (14,44) at one end and is mounted on the main pivot bearing (13,43) at the opposite end and is pivotable about the main pivot axis (12,42) from the initial position as far as the free position via the intermediate position, having a fixed secondary counter-bearing (05,35), and having a secondary pivot bearing (23,53), which (23,53) defines a secondary pivot axis (22,52), wherein the secondary pivot axis (22,52) is positioned on the main contact arm (11,41) parallel to and at a distance from the main pivot axis (12,42), and having a secondary contact arm (21,51), which (21,51) comprises a secondary contact (25,55) at one end and is mounted on the secondary pivot bearing (23,53) at the opposite end and is pivotable about the secondary pivot axis (22,52) from a contact position to a limit position and back to a rest position and has a secondary-arm length LN from the secondary pivot axis (22,52) as far as the end of the secondary contact (25,55), and having a tensioning device (24), which (24) connects the secondary contact arm (21) to the main contact arm (11) and is tensioned during the pivoting movement of the secondary contact arm (21,51) from the contact position into the limit position, wherein the secondary pivot bearing (23,53) is adjustable in a plane transverse to the secondary pivot axis (22,52) from an initial position into a free position via an intermediate position, wherein, during an adjustment from the initial position to the intermediate position, the secondary contact (25,55) abuts against the secondary counter-bearing (05,35) and a pivoting movement from the contact position to the limit position takes place, and wherein, when the intermediate position is exceeded during an adjustment to the free position, the tensioning device (24) causes a pivoting-back movement of the secondary contact arm (21,51) from the limit position into the rest position and the secondary contact (25,55) is at an increasing distance from the secondary counter-bearing (05,35), characterized in that the secondary contact arm (21,51) comprises a flow element (27,57,58), which (27,57,58) is arranged on the secondary contact (25,55) and, during the pivoting-back movement, causes air to flow onto the free end of the secondary contact (25,55) and has an effective resistance area FS of at least FS = 0.0005 * LN * LN and at most FS = 0.01 * LN * LN, wherein the resistance area FS is that area of the flow element (27,57,58) which extends in the longitudinal direction of the secondary contact arm (21,51) and in the direction of the secondary pivot axis (22,52).

2. Switching arrangement (01,31,31) according to Claim 1, characterized in that the flow element (27,57,58) is arranged on the secondary contact (25,55) on both sides in the direction of the secondary pivot axis (22,52).

3. Switching arrangement (01,31) according to Claim 1 or 2, characterized in that the flow element (27,57,58), at least on that side by way of which the secondary contact (25,55) abuts against the secondary counter-bearing (05,35), has a flat and / or blade-like design and extends in a longitudinal direction of the secondary contact arm (21,51) and in the direction of the secondary pivot axis (22,52).

4. Switching arrangement (01,31) according to one of Claims 1 to 3, characterized in that the flow element (27,57,58) consists of a non-conductive material.

5. Switching arrangement (01,31) according to one of Claims 1 to 4, characterized in that the resistance area FS is at least FS = 0.001 * LN * LN and / or at most FS = 0.004 * LN * LN.

6. Switching arrangement (31) according to one of Claims 1 to 5, characterized in that the tensioning device is arranged in and / or on the secondary pivot bearing (53).

7. Switching arrangement (01,31) according to one of Claims 1 to 6, characterized in that a deflecting element (36) is arranged on the secondary counter-bearing (05,35), and the secondary contact arm (21,51) has an elastic deformation region (26) or an articulated joint (56) perpendicularly to the secondary pivot axis (22,52), wherein, during an adjustment into the initial position, the secondary contact (25,55) is guided over the secondary counter-bearing (05,35) by the deflecting element (36).

8. Switching arrangement (01,31) according to Claim 7, characterized in that, during the pivoting-back movement, the flow element (27,57,58) comes into abutment with the deflecting element (36).

9. Switching arrangement (01,31) according to Claim 7 or 8, characterized in that the secondary contact arm (21,51) is adjustable beyond the initial position as far as an operating position and / or is pivotable beyond the contact position as far as an end position.

10. Switching arrangement (01,31) according to one of Claims 1 to 9, wherein the main contact arm (11,41 is pivotable about the main pivot axis (12,42) from the operating position as far as the free position via the intermediate position.

11. Switching arrangement (01,31) according to one of Claims 1 to 10, wherein the main contact (14,44) abuts against the main counter-bearing (04,34) in the initial position and, during the pivoting movement into the free position, is at an increasing distance from the main counter-bearing (04,34).