CN113826177A

CN113826177A - Switching device with self-cleaning contact

Info

Publication number: CN113826177A
Application number: CN202080036090.3A
Authority: CN
Inventors: P·维兹
Original assignee: Schaltbau GmbH
Current assignee: Schaltbau GmbH
Priority date: 2019-05-15
Filing date: 2020-04-28
Publication date: 2021-12-21
Also published as: WO2020229161A1; EP3970170A1; DE102019112683B3

Abstract

The invention relates to a switching device with a double interruption, comprising a first fixed contact (2) with a first contact surface (3), a second fixed contact (4) with a second contact surface (5), and a contact bridge (6) with a third contact surface (7) and a fourth contact surface (8), wherein the first contact surface and the third contact surface form a first contact point and the second contact surface and the fourth contact surface form a second contact point, wherein the switching device further comprises a drive mechanism with a drive element (1), which is connected to the contact bridge (6) and can be moved between an initial position and an end position, wherein the drive mechanism is designed such that, by a movement of the drive element from the initial position into the end position, the contact bridge (6) is transferred on the one hand in a first direction (21) from an open position into a closed position, in which open position, the first contact and the second contact are open, in the closed position the first contact and the second contact are closed, wherein, on the other hand, the contact bridge (6) is moved parallel to the contact surfaces in the second direction (20) after the first contact surface and the third contact surface have contacted each other and/or the second contact surface and the fourth contact surface have contacted each other. According to the invention, the contact bridge (6) is divided into a first half (9) and a second half (10) between the third contact surface (7) and the fourth contact surface (8) in one direction in such a way that both the third contact surface (7) and the fourth contact surface (8) are divided into a first half (11, 13) and a second half (12, 14), respectively, wherein the drive mechanism is designed in such a way that the first half (9) of the contact bridge and the second half (10) of the contact bridge move opposite one another when the contact bridge (6) is moved in the second direction (20).

Description

Switching device with self-cleaning contact

Technical Field

The present invention relates to a switchgear according to the preamble of independent claim 1.

Background

A switching device of this type has a double interruption with a first fixed contact (sometimes also referred to as fixed contact) with a first contact surface, a second fixed contact with a second contact surface, and a contact bridge with a third contact surface and a fourth contact surface, wherein the first contact surface and the third contact surface form a first contact point (sometimes also referred to as contact) and the second contact surface and the fourth contact surface form a second contact point, wherein the switching device further has a drive mechanism with a drive element which is connected to the contact bridge and can be moved between an initial position and an end position, wherein the drive mechanism is set up such that, by a movement of the drive element from the initial position into the end position, the contact bridge is on the one hand moved in a first direction from an open position into a closed position, in the open position, the first contact and the second contact are open, and in the closed position the first contact and the second contact are closed, wherein, on the other hand, the contact bridge is moved parallel to the contact surfaces in the second direction after the first contact surface and the third contact surface have made contact with each other and/or the second contact surface and the fourth contact surface have made contact with each other.

A switchgear according to the preamble of the independent claim 1 is known, for example, from JP S51-39356B 2. In such a switching device, the integral contact link is connected to the drive element via a bow spring (belleville spring), and when the contact link strikes a fixed contact, the contact link is displaced in a direction parallel to the contact surface by the design of the bow spring. As a result, contact surface friction is produced between the contact surfaces on the contact link and the contact surfaces of the fixed contact, which leads to a clean surface and thus an increased service life without external maintenance measures.

Disclosure of Invention

The object of the invention is to provide a switching device of this type which allows for an effective contact surface friction which protects the components as far as possible and thus ensures an increased service life.

This object is achieved by the features of the independent claim 1. The solution according to the invention for this purpose therefore exists in a switching device according to the preamble of independent claim 1 if the contact bridge is divided into a first half and a second half in such a way between the third contact surface and the fourth contact surface in a direction that both the third contact surface and the fourth contact surface are divided into the first half and the second half, respectively, wherein the drive mechanism is set up in such a way that the first half of the contact bridge and the second half of the contact bridge move opposite one another when the contact bridge moves in the second direction.

The solution according to the invention relates to the closing of the contact points of the double interruption of the switching device by means of a drive mechanism, wherein contact friction is carried out between the contact surfaces of the fixed contact and the contact surfaces on the contact bridge. The drive mechanism is preferably also designed such that a movement of the drive element from the end position into the starting position causes the contact bridge to be transferred from the closed position into the open position. In this case, the contact bridge halves are displaced in the second direction and in the first direction. Accordingly, contact friction also occurs when the drive element is moved back into the initial position.

The solution according to the invention provides the advantage that: the contact surface rubbing is performed as gently as possible. The opposite displacement of the halves of the contact bridge makes it possible in particular to achieve symmetrical loading on the switching device and a good contact process between the contact surfaces rubbing against one another with constant pressure and area.

The movement of the drive element by the drive mechanism can be effected mechanically or electrically.

Advantageous embodiments of the invention are the subject matter of the dependent claims.

In a preferred embodiment of the invention, it is provided that the first spring connects the first half of the contact bridge to the drive element in such a way that a deformation of the first spring brings about a first displacement of the first half of the contact bridge in the second direction, and that the second spring connects the second half of the contact bridge to the drive element in such a way that a deformation of the second spring brings about a second displacement of the second half of the contact bridge in the second direction, wherein the first displacement and the second displacement have opposite directions in the second direction. This embodiment of the opposite displacement of the contact bridge halves enables a simple implementation, which for this purpose can also be produced and installed cost-effectively and easily.

In a further preferred embodiment of the invention, it is provided that the switching device is designed such that the first spring and the second spring also act as contact pressure springs. This embodiment is particularly advantageous for the compactness of the switching device, since no further contact pressure springs have to be supported.

In a further preferred embodiment, the first and second springs are embodied as bow springs. This allows for a simple and cost-effective manufacture.

More preferably, the first and second springs are configured as leaf springs. Advantageously, the two leaf springs are U-shaped here, wherein one leg is connected to the drive element and one leg is connected to the contact bridge half. The bulges of the U-shaped leaf spring point in opposite directions and thus determine the direction of movement of the contact bridge halves in the second direction. This simple shape of the spring makes it possible to achieve a precise orientation of the movement of the contact bridge halves with little manufacturing effort.

It is particularly advantageous if the first spring is formed as a one-piece contact bridge spring together with the second spring. For this purpose, in particular, the parts of the first and second springs, through which the movement of the drive element is transmitted to the first and second springs, are designed in one piece in the form of the base surface of the contact bridge spring, and the two legs are guided to the first half of the contact bridge and to the second half of the contact bridge. The robustness of the spring, the force transmission between the drive element and the spring and the mounting are thereby improved in particular.

In a further preferred embodiment of the invention, it is provided that the one-piece contact bridge spring is stamped from a sheet metal part. By this embodiment, the manufacturing of the switching device can be simplified.

It is further preferred that the first and second springs are each centrally connected to a respective side of the contact bridge half, which side is opposite to the side of the contact bridge half having the contact surface. By means of this embodiment, a symmetrical loading of the drive element is ensured, and the loading on the contact bridge spring under pressure simplifies the bearing of the contact bridge spring relative to the contact bridge.

In a further preferred embodiment of the invention, it is provided that the first half of the contact bridge and the second half of the contact bridge rest against the stop on the drive element on the side of the contact bridge half on which the third contact surface and the fourth contact surface are located, at least when the first contact surface is not in contact with the third contact surface and the second contact surface is not in contact with the fourth contact surface. This ensures that the contact is mechanically broken by the movement of the drive element during the welding together. This also enables a simple connection of the contact bridge spring to the contact bridge and the drive element. It is particularly advantageous here if the ends of the contact bridge spring which are supported on the first and second halves of the contact bridge are bent perpendicularly to the contact bridge and are therefore located in two spring receptacles in the first and second halves of the contact bridge, and if the drive element has a surface on which at least one projection is located and on which a base surface of the contact bridge spring rests, wherein the base surface has a through-opening into which the projection of the drive element can be inserted. This connection of the contact bridge spring to the drive element and the contact bridge halves simplifies the assembly of the switching device.

In a further preferred embodiment of the invention, it is provided that the drive mechanism is designed such that the opposite displacement of the first half of the contact bridge and the second half of the contact bridge in the second direction is a linear displacement. A particularly simple construction of the switching device according to the invention is thereby achieved.

In a further preferred embodiment of the invention, it is provided that the first direction extends parallel to the movement of the drive element and perpendicular to the second direction. By means of this embodiment, particularly symmetrical loading of the components is produced and the structure can be designed as compactly as possible.

In a further preferred embodiment of the invention, it is provided that the first half of the contact bridge has the same dimensions as the second half of the contact bridge, wherein the first half and the second half of the third contact surface and the first half and the second half of the fourth contact surface have the same dimensions. This embodiment helps to distribute the load evenly over the various parts of the member.

According to another preferred embodiment of the invention, the movement of the drive element is controlled by a snap mechanism between the drive element and the trigger. For this purpose, a snap spring is located between the trigger and the drive element. This results in a rapid separation and closing of the contacts, which suppresses the formation of an arc.

Furthermore, it is preferred that the switching device has a positive closure between the trigger and the drive element, and that the switching device is designed such that the positive closure, after passing over the position of the trigger (which causes the triggering of the catch mechanism to close the contact), causes the drive element to move into the end position in a force-fitting manner mechanically on the basis of the movement of the trigger. Such a positive closure can be realized by recesses at the drive element and the trigger, between which recesses legs are located, which legs are rotatably supported and thus serve as a force-fitting connection between the trigger and the drive element from a certain trigger and drive element position. This configuration ensures closure at the contact and implementation of frictional movement of the contact bridge halves.

Furthermore, it is preferred that the switching device has a forced disconnection between the trigger and the drive element, and that the switching device is designed such that the forced disconnection, after passing over the position of the trigger (which causes the triggering of the catch mechanism to disconnect the contact), causes the drive element to move into the initial position mechanically in a force-fitting manner on the basis of the movement of the trigger. Such a positive disconnection can likewise be realized by recesses at the drive element and the trigger, between which recesses are situated legs which are rotatably supported and thus serve as a force-fitting connection between the trigger and the drive element from a certain trigger and drive element position. This configuration ensures disconnection of the contacts.

In a further preferred embodiment of the invention, it is provided that the switching device has, in addition to the contact bridge, at least one second contact bridge with two associated fixed contacts. The at least one second contact bridge can be designed according to the invention and is designed as a counterpart for the contact bridge. The contact site of the second contact bridge is then located in the open position of the second contact bridge when the contact bridge is located in the closed position; when the contact bridge is in the open position, the contact of the second contact bridge is in the closed position of the second contact bridge. The switching device can also be designed such that the forced closing of the contact link acts as a forced opening of the second contact link and the forced opening of the contact link acts as a forced closing of the second contact link. The switching device is therefore very suitable as a changeover switch (weichenschelter).

The invention is particularly suitable for use with a snap action switch (Schnappschalter). In such snap-action switches, as well as other switching devices, the drive element may be, for example, a push rod.

Drawings

Embodiments of the present invention are explained in more detail below with reference to the drawings. Here:

fig. 1 shows a detailed view from obliquely above of a part of a drive element, two fixed contacts and a contact bridge of a switching device according to the invention, with the drive element vertically separated for better visibility;

2a, b, c show three front views of the detailed view in FIG. 1, with the switching device according to the invention shown in three positions for different positions;

fig. 3 shows a front view through a section of a switchgear with two contact bridges, without an enclosure, a joint fixing the contacts and possible guides for better visibility.

Detailed Description

For the following explanation to apply, like parts are denoted by like reference numerals. If reference numerals are included in the figures that are not discussed in detail in the associated figure description, reference is made to the previous or subsequent figure description.

Fig. 1 shows a detailed view of a part of the drive element 1, the two fixed contacts 2, 4 and the contact bridge 6 from obliquely above. The illustrated components are part of a snap-action switch, and the drive element 1 is in this case designed as a push rod.

As can be seen from the figure, the first fixed contact 2 has a first contact surface 3, wherein the second fixed contact 4 has a second contact surface 5. The contact bridge 6 has a third contact surface 7 and a fourth contact surface 8. The pairing of the first contact surface 3 and the third contact surface 7 forms the first contact of the double interruption. A second pair of second contact surface 5 and fourth contact surface 8 forms a second contact point. It can also be seen in fig. 1 that the contact bridge 6 is divided into two parts having the same dimensions. This is the first half 9 of the contact bridge and the second half 10 of the contact bridge. The third contact surface 7 and the fourth contact surface 8 are also divided into two parts having the same dimensions, respectively. The first half 9 of the contact link has a first half 11 of the third contact surface and a first half 13 of the fourth contact surface. Correspondingly, the second half 10 of the contact bridge has a second half 12 of the third contact surface and a second half 14 of the fourth contact surface.

The contact bridge 6 is connected in a floating manner to the drive element 1 by means of an integrated contact bridge spring 15, wherein the first half 9 of the contact bridge is supported on a first leg 16 of the contact bridge spring 15 and the second half 10 of the contact bridge is supported on a second leg 17 of the contact bridge spring 15. The ends of the first leg 16 and of the second leg 17 are each supported centrally in the spring receptacle on the side of the

contact bridge halves

9, 10 remote from the contact surfaces 7, 8. In order to support the contact bridge spring 15 and the contact bridge 6 relative to the drive element 1, the drive element 1 has a first stop 23 and a second stop 22 which are parallel to one another and to the contact surfaces 3, 5, 7, 8. The first stop 23 has two projections 18, which act in perforations 19 in the contact bridge spring 15 and thus fix the contact bridge spring 15 relative to the drive element 1. In fig. 1, only the projection 18 is shown, based on a partial view of the drive element. The sides of the

contact bridge halves

9, 10 on which the third contact surface 7 and the fourth contact surface 8 are located bear against the second stop 22.

The drive element 1 is movable in a drive element movement direction 21. By this movement, the contact bridge 6 is also moved in a first direction coinciding with the drive element movement direction 21 and causes the contact faces 7, 8 and the contact faces 3, 4 to move towards each other or away from each other. By means of a floating connection via the contact bridge spring 15, the

contact bridge halves

9, 10 can be moved in a second direction 20 parallel to the contact surfaces and perpendicular to the drive element movement direction 21.

Fig. 2a, b and c show a front view of the detailed view in fig. 1 in three different positions in which the switching device can be located. The switching device is set up such that the drive element 1 is moved in the drive element displacement direction 21 from the initial position shown in fig. 2a to the end position shown in fig. 2 c. In the initial position, the first contact and the second contact are disconnected. If the drive element 1 is now displaced in the direction of the end position in the drive element displacement direction 21, the contact surface halves 11, 12, 13, 14 meet the contact surfaces 3, 5 by the displacement of the drive element 1. Such meeting of the contact surfaces with each other is shown in fig. 2 b. If the drive element 1 is moved still further into the end position, the first half 9 of the contact bridge and the second half 10 of the contact bridge are released from the stop 22 due to their support in the form of the contact bridge spring 15 and move in the opposite direction in the second direction 20, while the contact bridge spring 15 presses the third contact surface 7 against the first contact surface 3 and the fourth contact surface 8 against the second contact surface 5. This results in that the third contact surface halves 11, 12 rub on the first contact surface 3 in the opposite direction of the second direction 20 and the fourth contact surface halves 13, 14 rub on the second contact surface 5 in the opposite direction of the second direction 20 until the drive element is in the end position and the deflection of the

contact bridge halves

9, 10 is maximal. If the drive element 1 is moved from the end position into the initial position, the contact-

bridge halves

9, 10 are first moved in the second direction 20 until the contact-

bridge halves

9, 10 abut against the stop 22. Thereafter, the third contact surface 7 is released from the first contact surface 3 and the fourth contact surface 8 is released from the second contact surface 5, and the contact bridge 6 is moved together with the drive element 1 in the first direction to the initial position.

Fig. 3 shows a section through a switching device according to another embodiment, wherein the enclosure of the switching device, the joint of the fixed contact and possible guides of the components are not shown for better visibility. The switching device in fig. 3 shows, on the one hand, the contact bridge 6 with its associated fixed contacts 2, 4 and the contact bridge spring 15 which connects the contact bridge 6 to the drive element 1, in the form which is also shown in fig. 1. In addition to this first double interruption, a second contact bridge 24 is also arranged on the drive element 1 in the same manner and with the same design, the contact surface of the second contact bridge also lying opposite a fixed contact 25 with a contact surface.

The second contact bridge 24 is arranged at the drive element 1 in such a way that, when the drive element 1 is in the initial position, the contact face of the second contact bridge 24 lies on the associated contact face of the fixed contact 25 and the half of the second contact bridge 24 is maximally moved in the second direction 20 and, when the drive element 1 is in the end position, the contact face of the second contact bridge 24 does not contact the associated contact face of the fixed contact 25.

The movement of the drive element 1 in the drive element movement direction 21 between the initial position and the end position is caused by the trigger 26 and the catch mechanism. The trigger 26 is connected to the drive element 1 by a latch spring 27 and can be moved in a trigger direction 31 parallel to the drive element movement direction 21. The catch mechanism causes the trigger 31 to move in the opposite direction to the direction of movement 21 of the drive element. The snap spring 27 enables a quick switching between the initial position and the end position, which reduces the risk of arcing.

In order to ensure that the contacts are separated or closed and that friction occurs between the contact surfaces, a positive closing and a positive opening are integrated in the switching device. The positive-locking and positive-unlocking mechanical connection between the trigger 26 and the drive element 1, which means a positive-locking mechanical connection, can move the drive element and therefore the contact bridge away from the respective fixed contact even in the event of a malfunction of the snap spring and when the contact surfaces are welded together. The connection also ensures that the separate contact surfaces are frictionally moved over the contact surfaces of the fixed contact parts. Such positive closure and positive opening are achieved by means of a rotatably supported leg 32 which is located in a recess 28 at the drive element 1 and in a recess 29 at the trigger 26. The switching device is designed such that, as soon as the trigger 26 has moved past the respective jump point, the leg 32 establishes a non-positive mechanical connection between the trigger 26 and the drive element 1, from which jump point the latch spring should move the drive element 1. The movement of the trigger is caused by an external force by the operator when the drive element 1 should be transferred from the initial position into the end position, or by a return spring 30 or return springs 30 when the drive element 1 is transferred from the end position into the initial position.

List of reference numerals

1 drive element

2 first fixed contact part

3 first contact surface

4 second fixed contact part

5 second contact surface

6 contact bridge

7 third contact surface

8 fourth contact surface

9 first half of contact bridge

10 second half of contact bridge

11 first half of the third contact surface

12 second half of the third contact surface

13 first half of the fourth contact surface

14 second half of the fourth contact surface

15 contact bridge spring

16 contact bridge spring first leg

17 second leg of contact bridge spring

18 projection

19 perforation

20 the second direction

21 direction of movement of the driving member

22 second stop

23 first stop

24 second contact bridge

25 second pair of fixed contacts

26 trigger

27 circlip

28 grooves in the drive element

29 recess in trigger

30 return spring

31 direction of movement of the trigger

32 rotatably supported.

Claims

1. A switching device with double interruption has a first fixed contact (2) with a first contact surface (3), a second fixed contact (4) with a second contact surface (5), and a contact bridge (6) with a third contact surface (7) and a fourth contact surface (8),

wherein the first contact surface (3) and the third contact surface (7) form a first contact point and the second contact surface (5) and the fourth contact surface (8) form a second contact point,

wherein the switching device further has a drive mechanism with a drive element (1), which is connected to the contact bridge (6) and is movable between an initial position and a final position,

wherein the drive mechanism is set up such that, by a movement of the drive element (1) from the initial position into the end position, the contact bridge (6) is transferred on the one hand in a first direction from an open position, in which the first contact and the second contact are open, into a closed position, in which the first contact and the second contact are closed, wherein, on the other hand, the contact bridge (6) is moved parallel to the contact faces (3, 5, 7, 8) in a second direction (21) after the first contact face (3) and the third contact face (7) have made mutual contact and/or the second contact face (5) and the fourth contact face (8) have made mutual contact,

characterized in that the contact link (6) is divided in one direction between the third contact surface (7) and the fourth contact surface (8) into a first half (9) and a second half (10) in such a way that both the third contact surface (7) and the fourth contact surface (8) are divided into a first half (11, 13) and a second half (12, 14), respectively, wherein the drive mechanism is designed in such a way that the first half (9) of the contact link and the second half (10) of the contact link move opposite one another when the contact link is moved in the second direction (20).

2. A switching device according to claim 1, characterized in that a first spring connects the first half (9) (1) of the contact bridge with the drive element in such a way that a deformation of the first spring causes a first displacement of the first half (9) of the contact bridge in the second direction (20), and a second spring connects the second half (10) of the contact bridge with the drive element (1) in such a way that a deformation of the second spring causes a second displacement of the second half (10) of the contact bridge in the second direction (20), wherein the first and second displacements have opposite directions in the second direction (20).

3. The switching device according to claim 2, characterized in that the switching device is set up such that the first spring and the second spring also act as contact pressure springs.

4. The switchgear as claimed in any of claims 2 to 3, wherein the first and second springs are configured as bow springs.

5. The switching device as claimed in one of claims 2 to 4, characterized in that the first spring together with the second spring is constructed as an integral contact bridge spring (15).

6. A switching device according to claim 5, characterized in that the integrated contact bridge spring (15) is stamped from sheet metal.

7. The switching device according to any one of claims 2 to 6, characterized in that the first spring and the second spring are each centrally connected with a respective side of a contact bridge half (9, 10) which is situated opposite a side with a contact face (7, 8).

8. The switching device according to claim 7, characterized in that the first half (9) of the contact bridge and the second half (10) of the contact bridge bear against a stop (22) at the drive element (1) on the side of the half of the contact bridge on which the third contact surface (7) and the fourth contact surface (8) are located, at least when the first contact surface (3) and the third contact surface (7) and the second contact surface (5) do not touch the fourth contact surface (8).

9. The switching device as claimed in one of claims 1 to 8, characterized in that the drive mechanism is set up such that the opposite movement of the first half (9) of the contact bridge and the second half (10) of the contact bridge in the second direction (20) is a linear movement.

10. A switching device according to any one of claims 1-9, characterized in that the first direction extends parallel to the movement of the drive element (21) and perpendicular to the second direction (20).

11. The switching device according to any one of claims 1 to 10, characterized in that the first half (9) of the contact bridge has the same dimensions as the second half (10) of the contact bridge, wherein the first half (11) and the second half (12) of the third contact surface (7) and the first half (13) and the second half (14) of the fourth contact surface (8) have the same dimensions.