CN114041197A

CN114041197A - Electrical contact system for a switching device

Info

Publication number: CN114041197A
Application number: CN202080035942.7A
Authority: CN
Inventors: ***·赫尔曼; 艾瑞克·赫佐格; 尼尔斯·戈勒
Original assignee: Johnson Electric Guangdong Co Ltd
Current assignee: Johnson Electric Guangdong Co Ltd
Priority date: 2019-07-02
Filing date: 2020-07-02
Publication date: 2022-02-11
Anticipated expiration: 2040-07-02
Also published as: DE102019117804B4; CN114041197B; EP3981019A1; DE102019117804A1; WO2021001465A1

Abstract

The invention relates to an electrical contact system (2) for a switching device (1), comprising at least one pair of contacts (3), said contacts (3) having a fixed contact (4) and a movable contact (5). The movable contact (5) is connected to a slider (15). A planar contact carrier (7) extends in its longitudinal cross section and is connected at a first end (11) to a second busbar (13). A second end (12) of the contact carrier (7) is connected to the slider (15). A spring element (18) has a first spring arm (22) and a second spring arm (23) and a pressure part (24) arranged between them in the region of the movable contact piece (5). The first spring arm (22) is connected to the second busbar (13) at the first end (11). The second spring arm (23) is also connected to the slider (15) at its free end (21).

Description

Electrical contact system for a switching device

Technical Field

The present invention relates to an electrical contact system for a switchgear, wherein the switchgear used in the present invention may include relays, switches, contactors and circuit breakers.

Background

Switching devices such as relays, switches, contactors and circuit breakers should have the following characteristics: due to the low electrical resistance and low losses between the connection terminals, high efficiency and safety of the device during operation, in particular with respect to heating and fire protection and long service life, can be achieved, which means that as many switching operations as possible are carried out under load; and protective measures to prevent the contacts from sticking to each other due to high short-circuit currents, for example in the event of an electrical fault.

In conventional switching devices, the spring element ensures that the movable contact piece lifts off the fixed contact piece quickly when the contact is released, thereby reducing wear of the contact piece.

In relays in particular, such spring elements are usually made of steel and riveted to the movable contact piece. A disadvantage associated with these steel elements riveted to the movable contact is due to the high load and low flexibility, which in turn only contributes to a minimal tolerance compensation.

Spring elements or mechanical coupling elements (hereinafter slider) made of steel connected to the magnetic actuator of the switching device are also known. A magnetic actuator is generated and then the slider transfers the force required to open or close the contacts. Here a spring may be used to release two or more contacts simultaneously. However, a disadvantage of connecting the spring element to the actuator or the slider is that a device constructed in this way is hardly suitable for delaying the opening or closing of at least two pairs of contacts. This delayed opening or closing of the contacts is also referred to as a lead-lag switching characteristic.

Another form known in the prior art comprises a spring element which is integrated into the current path of the contact carrier for the movable contact. However, this will result in a larger mechanical load than the above-described direct connection of the spring element to the movable contact. In addition to this, it has the disadvantage that the spring heats up, which leads to a deformation of the slider and thus to a shortening of the service life of the contact system. Furthermore, the roll-off movement of the contacts is limited, since the contact carrier is deformed during the short circuit due to the following conditions. In the case of a spring element connected to a movable contact, for example by riveting, the high stiffness leads to a reduced flexibility of the spring element and thus to a limited roll-off movement of the contacts. In the case of a spring integrated in the contact carrier of the movable contact, the roll-off movement is limited due to the reduced flexibility of the current path of the contact carrier of the movable contact.

Disclosure of Invention

The basic object of the present invention is defined as providing a space-saving electrical contact system which can be produced economically, provides high performance, has a long service life and allows reliable absorption and transfer of short-circuit forces.

The object of the invention is solved by the use of an electrical contact system and corresponding advantages are created in a switching device equipped with an electrical contact system. Further embodiments are provided.

The electrical contact system constructed according to the invention is suitable for switchgear, such as relays, having at least one pair of contacts with one fixed contact, which is connected to a first busbar having a fixed position compared to the housing of the switchgear, and one contact which is movable relative to the fixed contact, wherein the contact is connected to a slider and can be moved by the slider in such a way that the pair of contacts are opened and closed; a planar contact carrier to which the movable contact is connected, wherein the contact carrier extends in its longitudinal cross-section along its longitudinal axis from a first end to a second end, wherein the first end is connected to a second busbar whose position is fixed relative to the housing of the switching device, wherein the second end of the contact carrier is connected to the slider; one spring element has a first spring arm and a second spring arm and a pressure part arranged between them in the region of the movable contact, wherein the first spring arm is connected to the second busbar at a first end of the contact carrier and wherein the second spring arm is also connected to the slider at its free end in such a way that the spring element exerts a contact force on the movable contact via the pressure part.

The spring element has a lower electrical conductivity than copper or has an electrically insulating coating, for example an insulating varnish. An electrically insulating spring element may be useful if a large part of the current flows through the spring element, since this allows to reduce the current in a contact carrier designed as a layered structure. This reduces the repulsive force, referred to as "blow-off force", in the layered contact carrier in the short circuit test.

Furthermore, the spring element is connected to the second busbar and has at least one spring arm having a first spring arm and a second spring arm, wherein the first spring arm extends from the connecting section upwards into a position with at least one pressure portion, and the second spring arm extends from said position to a free end of the spring arm. This enables a defined contact force even after overheating of the contact carrier and ensures reliable maintenance of the relay function.

Tolerance problems can be controlled in a technically elegant manner if the planar contact carrier is substantially straight along its longitudinal axis from the first end to the second end in its longitudinal cross section.

According to the invention, at least one pressure part is positioned such that a direct or indirect force-locking connection between the pressure part and the movable contact piece can be produced by preloading of a spring element, thereby allowing a force to be exerted on a pair of contacts.

When the pair of contacts is electrically disconnected, the spring element remains preloaded and exerts a contact force on the contacts by the pressure portion. Advantageously, the contact force is effective immediately upon contact closure, compressing the contacts and minimizing contact bounce.

Alternatively, the contact carrier of the movable contact may be positioned in such a way that it increases the contact force and further reduces bounce and contact resistance when the contact is closed.

In order to be able to benefit from the attractive or repulsive forces in the conductor through which the current flows, the contact carrier is ideally connected to the second busbar in such a way that it forms a V-shape together with the second busbar in longitudinal section, in other words along the longitudinal axis.

The conceptual design according to the invention focuses on the use of a spring element with a low electrical conductivity to connect to the same busbar as the contact carrier of the movable contact. Such spring elements combine various beneficial mechanisms of action with each other. The spring element is preferably designed in the form of a sheet or a strip. In one embodiment, the spring element is a leaf spring.

The spring element may be made of a paramagnetic or alternatively a diamagnetic material. The spring element should preferably be made of a material having paramagnetic properties. Particularly preferred materials here are stainless steels or stainless steel alloys. The material of the spring element must necessarily be less conductive than the material of the fixed busbar and the contact carrier in order for as little current as possible to flow through the spring element. The difference in electrical conductivity between steel and copper is a factor between 6 and 7. For example, if the fixed position busbar and the contact carrier are made of aluminum instead of copper, but the spring is still made of steel, the coefficient conductivity between the two would be nearby, which is still sufficient. All materials having a lower electrical conductivity than steel provide the spring element with a sufficiently low electrical conductivity.

One beneficial effect is based on the force applied to the contact pair, which is generated by the preloading of the spring element and presses the contacts together. This creates pressure portions, so-called points a, at the interface between the contacts, where these pressure portions promote the flow of current. Here, the larger the pressure, the larger the size (area) of the pressure portion available for the current flow, and the lower the resistance at the pressure portion.

A further improvement of the prior art is achieved according to a preferred embodiment of the invention, by which the electrical contact system comprises a plurality of pairs of contacts, a contact force being generated for each pair of separable contacts, respectively. Pairs of contacts may be connected in parallel here to keep the resistance always low throughout the life even if one pair of contacts burns out. The plurality of movable contacts may be arranged on the contact carrier transversely to their longitudinal axis or in the direction of the longitudinal axis or one after the other transversely to the longitudinal axis, but offset in the direction of the longitudinal axis. As mentioned above, the geometry of a pair of contacts that are burned out can change, for example due to burning itself, or in particular a bimetal contact rivet, due to delamination. The change in shape results in a change in the very important spring pretension and thus also in the contact force. To ensure that an unburnt contact pair is not changed by a burnt contact pair, a force is generated separately for each pair of contacts. This is achieved by designing the spring element advantageously as a leaf spring with separate spring arms for each pair of contacts. This results in a low resistance, even when multiple pairs of contacts are used, one of which can burn out.

Another aspect of the invention relates to a switching device, such as a relay, comprising an electrical contact system according to the invention. The corresponding switching device also comprises an excitation coil and a solenoid, classified as an armature, which is operatively connected to a slide, which acts as a mechanical coupling element. The magnet coil can thereby generate a force as a result of the magnetic field generated by it, which can then be applied to the electrical contact system via the armature and the mechanical coupling element, so that the electrical contact system can be switched by the magnet coil.

Another advantageous mechanism of action of the spring element is based on the generation of a force on the armature/solenoid, which then supports the opening process, so that the contacts can be opened as quickly as possible. The greater the preload force of the spring element, the faster the opening speed of the contacts and the less severe the burning out (corrosion) of the contacts due to the opening arc when opening the electrical load. The lighter the degree of contact burning, the more switching operations can be performed, thereby increasing the service life of the corresponding switching device.

The low spring constant of the spring element is particularly advantageous here. The spring constant generally represents the ratio of the force acting on the spring that elongates the spring. Due to the way the system operates, a significant portion of the spring force is applied to the solenoid after the contacts are opened. Only a small part of the contact force is applied, which is a result of the preloading of the spring element (leaf spring) between the movable contact and the busbar connected to the movable contact carrier. The force component counteracts the opening movement and increases as the contacts open wider, because the spring part is increasingly preloaded with the opening movement. A low spring constant means that increasing the preload distance results in only a minimal increase in force, and therefore the solenoid decelerates only very slightly in the opening movement. This results in a faster opening movement of the contacts, thereby extending the service life of the device.

Another advantage is based on the high thermal stability of the spring material. The contact system heats up during the operation of the switch. The spring material has a corresponding thermal stability, which ensures the mechanical properties at elevated temperatures.

Another advantage is based on the fact that the spring material is either not electrically conductive or only low electrically conductive and, in the case of stainless steel, for example has paramagnetic properties. The relationship between the low conductivity or paramagnetism of the spring element and the beneficial effect, i.e. preventing contact soldering, is explained in more detail below.

In the event of a short circuit, there are two key functions to prevent contact welding. One of these effects focuses on the relative motion between the switch contacts when current flows through the contacts. Another effect focuses on increasing the contact force to increase the contact surface. First, this reduces the current density in the pressure portion between the contacts. Secondly, the pinch resistance (holm force) occurring between the contacts due to the current flow is compensated. The pinch resistance (hall force) always acts in the direction of opening of the contacts, which would result in opening of the contacts in the event of a short-circuit fault if there were no corresponding reaction force. The force required to achieve these effects is generated by the magnetic field, which is generated by the short circuit current itself. These effects should not be influenced by the spring element. First, the low conductivity prevents high short circuit currents from flowing through the spring element, so that no associated magnetic field is formed around the spring element. Secondly, the application of a reluctance force on the spring or surrounding components due to the magnetic field around the current path can be prevented by the paramagnetism of the spring element. This makes a valuable contribution to preventing the contacts from sticking together in a practical manner of operation, i.e. the relative movement between the switch contacts is not affected by the spring element.

Another advantageous mechanism of action is achieved by the spring element acting with a normal force on the pressure part. Due to the spring preload, a force-locking connection is established between the electrical switch contact and the spring element. However, the force action here does not contain any torque component. The spring element rests with its pressure part only on the rear face of the movable contact or on the part of the contact carrier adjacent to the movable contact and is not connected thereto. Therefore, the compressive force, also referred to as normal force in the following, can only be transmitted orthogonally from the spring element to the contacts. The transmission of torque or significant lateral forces is not possible or is thus prevented. This results in the situation that the described relative movement transverse to the contact surfaces is not impaired in the event of a short circuit. The contacts can be prevented from sticking together more safely, since the applied mode of action is not affected.

In a particularly preferred embodiment of the invention, the at least one movable contact has a projection, also referred to as a rivet collar, on its rear side, which projection extends through a corresponding mounting hole in the contact carrier. This allows the spring arm of the spring element to bear directly against the projection of the contact, the rivet ring, have a pressure portion and exert pressure. However, the at least one spring arm should preferably have, in the region of the pressure portion, a widened annular portion which is arranged transversely to the longitudinal axis of the contact carrier, with a central recess which is positioned such that it rests on the contact carrier in the preloaded state and surrounds the projection of the rear face of the current movable contact. In this embodiment, the at least one spring arm preferably has two pressure portions in opposite positions of the widened annular portion.

Contacts without rivet rings may also be used. These can be soldered or welded to the contact carrier, so that no mounting holes are required. In this case, the spring arm of the spring element can bear directly against or press against the contact carrier on the rear side of the fixed position of the movable contact with only one pressure portion.

In a preferred embodiment in terms of production and function, the slider has a recess into which the second end of the contact carrier and the free end of the second spring arm of the spring element protrude.

Drawings

FIG. 1: a cross-sectional view of an electrical contact system with spring elements for a relay as a switching device;

FIG. 2: a side view of a portion of an electrical contact system;

FIG. 3: a spring element with two spring arms;

FIG. 4: a perspective view of an electrical contact system having two contacts; and

FIG. 5: a front view of a portion of an electrical contact system having two differently sized contacts.

Detailed Description

Fig. 1 shows a schematic cross-sectional view of a relay 1 as an example of a switching device 1, in which an electrical contact system 2 having the features of the invention is applied. The electrical contact system 2 comprises at least one pair of contacts 3, which are formed by a pair of contacts 4, 5. Here, at least one pair of contacts comprises a fixed contact 4, said fixed contact 4 being connected to a first busbar 6 having a fixed position relative to a housing 33 of the switching device, and a movable contact 5 which is movable relative to the fixed contact 4 to perform a switching function, the contacts of said contacts being positioned relative to each other in such a way that said movable contact 5 can be pressed against the fixed contact 4 by means of a contact force.

In addition to this, the electrical contact system 2 comprises a planar contact carrier 7 for the at least one movable contact 5. The contact carrier 7 can have a spring characteristic and is therefore also generally referred to as a contact spring.

As shown in fig. 1, the planar contact carrier 7 is made of two current paths 8, 9 lying on top of one another and is configured substantially straight in its longitudinal cross section along its longitudinal axis from a first end 11 to a second end 12. The contact carrier 7 is connected with its first end 11 to a second busbar 13, the second busbar 13 having a fixed position, preferably riveted, relative to the housing 33 of the switchgear and forming a V-shape therewith in its longitudinal section. The at least one movable contact 5 is connected in the region of the second free end of the contact carrier 7. In the exemplary embodiment shown, the contact carrier 7 comprises a first, straight current path 8 and a second current path 9, wherein the second current path 9 is also straight, with the exception of a curved portion 10 which projects out of its plane and which extends transversely to the longitudinal axis over the entire width of the contact carrier. Said bent portion 10 is located near a first end 11 of the contact carrier 7, the contact carrier 7 being connected to a second busbar 13 via said first end 11.

The relay 1 also has a solenoid actuator for moving the contact carrier 7 into the respective relay position. The solenoid actuator has a magnetic coil, a permanent magnet and an armature 14, the armature 14 being held pivotably on the magnetic coil between two switching positions. The armature 14 is connected to a mechanical coupling element 15 in the form of a slide 15, so that the slide 15 can be raised and lowered by a rotary movement of the armature 14. The armature 14 may also be classified as a lifting magnet or solenoid. The armature 14 is held by the slider 15 from above and below at its lower end section 16 in the direction of movement of the lifting movement of the slider 15. In the region of the free end 12 of the contact carrier 7, the upper end 17 of the slider 15 is located on its underside. The slider 15 connected to the armature 14 can then transmit the force generated by the magnetic field of the excitation coil in the relay 1 to the contact carrier 7 with the at least one connected movable contact piece 5, so that the contact between the fixed contact piece 4 and the movable contact piece 5 can be opened or closed by the excitation coil.

As a characteristic key of the present invention, said electrical contact system 2 comprises a spring element 18 with low electrical conductivity, preferably made of stainless steel or a stainless steel alloy. The spring element 18 is connected to the second busbar 13, and the contact carrier 7 for the movable contact 5 is also connected to the second busbar 13. Said spring element 18 comprises a connecting portion 19, the spring element 18 being connected (preferably riveted) to the second busbar 13 by means of the connecting portion 19. Starting from the connecting portion 19, the spring element 18 has at least one spring arm 20, which extends from the connecting portion 19 as far as a free end 21 of the spring element 18. At least one spring arm 20 may be divided into two distinct

spring arm portions

22, 23. The first spring arm 22 extends from the connection portion 19 to the pressure portion 24, and the spring element 18 rests only on the back face of the movable contact 5 or on a portion of the contact carrier 7 close to the back face of the movable contact 5, but is not connected to said movable contact 5 or contact carrier 7. Starting from pressure part 24, second spring arm 23 extends as far as free end 21 of spring arm 20. The distance between the contact carrier 7 and the second spring arm 23 increases here starting from a pressure portion 24, at which pressure portion 24 the spring element 18 still rests on the movable contact 5 or the contact carrier 7 and continues as far as the free end 21 of the spring arm 20. This means that the two

different spring arms

22,23 together form a V-shape.

Due to the preloading of the spring element 18, schematically depicted as a continuous line by the second spring arm portion 23, a force-locking connection 25 exists between the pressure portion 24 and the movable contact piece 5, and thus exerts a force on the contact 3 to press the contact pieces 4, 5 together, as indicated by arrows 26. The force 26 applied to the contact 3 creates contact points, so-called points a, at the interface between the contact elements 4, 5, wherein these contact points promote the flow of current. Here the larger the contact force, the larger the size (area) of the contact point available for current flow, as indicated by arrow 27, and the lower the electrical resistance at the contact point.

Another advantageous mechanism of action of the spring element 18 is based on generating a force on the armature/solenoid 14, wherein the force is represented by the arrow in fig. 1, which then supports the armature/solenoid 14 during opening. The force also ensures that the contacts 3 can open as quickly as possible. The greater the pretensioning force of the spring element 18, the faster the opening speed of the contact 3.

Due to the way the system operates, a significant portion of the spring force is applied to the armature/solenoid 14 after opening the contacts 3. Although the spring arm 23 is always preloaded, a mechanical contact is established between the second end 12 of the contact carrier and the slider 15 when the electrical contact is opened. This changes the flow of force. The preload force of the spring element 18 is completely absorbed in the slider 15 and no longer dissipated by the armature 14. When the contacts are opened, the resultant of the spring preload force 28 on the armature 14 is equal to zero. This situation is schematically illustrated in fig. 1 in the form of a dashed line, which depicts the second spring arm 23'. Only a small part of the previously applied contact force is applied, which is a result of the preloading of the first spring arm 22, which acts as a spring element interposed between the bus bar 13, to which the movable contact 5 is connected to the movable contact carrier 7. The force component counteracts the opening movement of the movable contact piece 5 and increases as the contact opens wider, since the spring arm 22 is increasingly preloaded with the opening movement. A low spring constant means that an increased preload distance results in only a minimal increase in force, so that the solenoid 14 slows down only very slightly in its opening movement. This results in a faster opening movement of the contacts 3, resulting in a longer service life of the device.

When the contacts 3 of the pair are electrically open, the spring element 18 remains preloaded and exerts a contact force 26 on the contacts via the pressure portion 24. Advantageously, said contact force is effective immediately upon closure of the contacts, so as to compress the contacts 3 and minimize bouncing of the contacts 3.

Furthermore, a beneficial mechanism of action is achieved by the spring element 18 generating a normal force action on the pressure part. Due to the spring preload, a force-locking connection is established between the contacts 3 of the switch and the spring element 18. However, the force action here does not contain any torque component. The spring element 18 rests with its pressure section 24 only on the rear side of the movable contact 5 or on a part of the contact carrier 7 adjacent to the rear side of the movable contact 5 and is not connected to said part. The compressive force can therefore only be transmitted perpendicularly from the spring element 18 to the contact 3. The transmission of torque or significant lateral forces is not possible or is thus prevented. This means that relative movements transverse to the contact surfaces are not affected in the event of a short circuit. This provides greater security against the contacts sticking together.

In a preferred embodiment in terms of production and function, the slider 15 has a recess 35 into which the second end 12 of the contact carrier 7 and the free end 21 of the second spring arm 23 of the spring element 18 project.

Fig. 2 shows a side view of a part of the electrical contact system 2. Part of the electrical contact system 2 comprises a planar contact carrier 7 for the at least one movable contact 5. As shown in fig. 2, it comprises two current paths 8, 9 lying on top of one another and being constructed substantially straight along its longitudinal axis in its longitudinal cross section from a first end 11 to a second end 12. The contact carrier 7 is connected by its first end 11 to a second busbar 13, for example by means of a riveted joint, and forms a V-shape in its longitudinal section together with the second busbar 13. At least one movable contact 5 is connected in the region of the second free end 12 of the contact carrier 7. The contact carrier 7 comprises a first, straight current path 8 and a second current path 9, wherein the second current path 9 is also configured straight, with the exception of a curved section 10 which projects outwards and extends transversely to the longitudinal axis, which curved section 10 extends transversely to the longitudinal axis in a section adjacent to the first end across the entire width of the contact carrier. In addition to the contact carrier 7, a spring element 18 is also connected to the second busbar 13. The spring element 18 includes a connecting portion 19, and the spring element 18 is fixed to the second bus bar 13 via a rivet connection with the connecting portion 19. Starting from the connecting portion 19, the spring element 18 has a spring arm 20 which extends from the connecting portion 19 as far as a free end 21 of the spring element 18. Spring arm 20 may be divided into two distinct spring arm portions 22, 23'. The first spring arm 22 extends from the connection portion 19 to the pressure portion 24, and the spring element 18 rests only on the back face of the movable contact 5 or on a portion of the contact carrier 7 close to the back face of the movable contact 5, but is not connected to said movable contact 5 or contact carrier 7. Starting from pressure part 24, second spring arm 23' extends as far as free end 21 of spring arm 20. The two spring arms 22,23' together form a V-shape.

Fig. 3 shows a spring element 18 constructed according to an advantageous embodiment of the invention. The exemplary embodiment relates to a multi-contact system on which at least two movable contacts are arranged and connected transversely to the longitudinal axis 34 of the contact carrier in the region of the second free end of the contact carrier. Multiple pairs of contacts can then be switched in parallel. In this case, the spring element 18 can be designed as a leaf spring with a connecting section 19 and

separate spring arms

20a, 20b starting from the connecting section 19. In the region of the

pressure portions

24a, 24b, the spring arms 20 a; 20b each have a widened portion 29 a; 29b, which are also referred to below as spring tongues 29 a; 29 b. Each spring tongue 29 a; 29b have a central recess 30 a; 30b, substantially making it annular. Each spring arm 20 a; 20b in the annular spring tongue 29 a; 29b has two pressure portions 24 a; 24 b.

Fig. 4 shows a perspective view of an electrical contact system 2 with two pairs of

contacts

3a, 3b, in which the spring element 18 shown in fig. 3 is used. A double contact system is produced in which, in the region of the second free end 12 of the contact carrier 7, two

movable contacts

5a, 5b are arranged and connected transversely to the longitudinal axis of the contact carrier and each form a pair with a corresponding fixed contact 4 a; 4b, contact 3 a; 3b, and 3 b. In the embodiment shown, the contact carrier 7 is divided into two

parallel legs

31a, 31b at least at the end carrying the contacts. The

recesses

30a, 30b ensure that the

pressure portions

24a, 24b of the

spring tongues

29a, 29b do not rest directly on the movable contact 5 a; 5b, but rests on an adjacent portion of the contact carrier 7, as a protrusion 32a formed on the back of the

movable contacts

5a, 5 b; 32b, the protrusions 32 a; 32b are located within the

recesses

30a, 30b, are guided through the contact carrier 7 through corresponding holes in the contact carrier 7, and project from the contact carrier 7.

Fig. 5 shows a front view of a part of an electrical contact system 2 with two contacts of different sizes. Different sizes of

movable contacts

5a, 5b and their

protrusions

32a, 32b formed on the back surface also require different sizes of

spring tongues

29a, 29b and different sizes of

recesses

30a, 30b in

spring arms

20a, 20 b.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-listed embodiments, and any simple changes or equivalent substitutions of technical solutions that can be obviously obtained by those skilled in the art within the technical scope of the present invention are within the protection scope of the present invention.

REFERENCE SIGNS LIST

1 Relay, switching device

2 electrical contact system

3 contacts, contact pairs

3a contact, contact pair

3b contacts, contact pairs

4 contact element and fixed contact element

4a contact and fixed contact

4b contact and fixed contact

5 contact and movable contact

5a contact and movable contact

5b contact and movable contact

6 first bus bar

7 contact carrier for a movable contact

8 Current path of contact carrier of movable contact

9 Current path of contact carrier of movable contact

10 curved part

11 first end of contact carrier of movable contact

12 second end of contact carrier

13 second bus bar

14 armature, solenoid valve

15 mechanical coupling element, slider

Lower end section of 16 slide

17 upper end of the slide block

18 spring element

19 connecting part of spring element

20 spring arm

20a first spring arm (with two contact system)

20b first spring arm (with two contact system)

21 free end of spring element

22 first spring arm

23 second spring arm with preloaded spring element

23' second spring arm with non-preloaded spring element

24 pressure part

24a pressure part

24b pressure part

25-force locking connection

26 force of the spring element on the contact, contact force

27 current (I)

28 force of spring element on armature

29a first spring tongue, widened part (with two contact systems)

29b second spring tongue, widened part (with two contact system)

30a first spring tongue recess

30b recess of second spring tongue

31a first leg of a contact carrier (with two contact system)

31b second leg of contact carrier (with two contact system)

32a projection of the back surface of the first movable contact

32b projection of the back surface of the second movable contact

33 casing

34 longitudinal axis of contact carrier

35 grooves in the slider

Claims

1. An electrical contact system (2) for a switching device (1), comprising:

at least one pair of contacts (3) has one fixed contact (4), said fixed contact (4) being connected to a first busbar (6) having a fixed position with respect to a housing (33) of the switchgear, and one contact (5) which is movable with respect to said fixed contact (4), wherein said contact (5) is connected to a slider (15) and said contact (5) is moved by the slider (15) so that said at least one pair of contacts (3) open and close with respect to each other;

-a planar contact carrier (7), to which contact carrier (7) the movable contact (5) is connected, wherein the contact carrier (7) extends in its longitudinal cross-section from a first end (11) along its longitudinal axis (34) to a second end (12), wherein the first end (11) is connected to a second busbar (13), the position of which second busbar (13) is fixed with respect to a housing (33) of the switchgear, wherein the second end (12) of the contact carrier (7) is connected to the slider (15); and

a spring element (18) having a first spring arm (22) and a second spring arm (23) and a pressure part (24) arranged between them in the region of the movable contact piece (5);

the method is characterized in that: the first spring arm (22) is connected to the second busbar (13) at the first end (11) of the contact carrier (7), and the second spring arm (23) is connected to the slider (15) at its free end (21) in such a way that the spring element (18) exerts a contact force (26) on the movable contact (5) via a pressure portion (24).

2. Electrical contact system (2) according to claim 1, characterized in that: the spring element (18) is pressed against the movable contact (5) by the pressure portion (24) even when the pair of contacts (3) is electrically disconnected.

3. Electrical contact system (2) according to claim 1, characterized in that: the spring element (18) is curved in the region of the pressure part (24), in such a way that the spring element (18) has a V-shaped cross section in longitudinal section at least in the region of the pressure part (24).

4. Electrical contact system (2) according to claim 1 or 2, characterized in that: the spring element (18) has a lower electrical conductivity than copper or has an electrically insulating coating.

5. Electrical contact system (2) according to any of the preceding claims, characterized in that: the spring element (18) is made of a paramagnetic or alternatively diamagnetic material.

6. Electrical contact system (2) according to claim 5, characterized in that: the spring element (18) is made of stainless steel or a stainless steel alloy.

7. Electrical contact system (2) according to any of the preceding claims, characterized in that: the contact carrier (7) is connected to the second busbar (13) in such a way that it forms a V-shape or a U-shape together with the second busbar in a longitudinal section along the longitudinal axis.

8. Electrical contact system (2) according to any of the preceding claims, characterized in that: the electrical contact system (2) comprises a plurality of pairs of contacts (3a, 3b), wherein a plurality of movable contacts (5a, 5b) are arranged on a contact carrier (7) one after the other transverse to the longitudinal axis thereof or in the direction of the longitudinal axis or transverse to the longitudinal axis, but offset in the direction of the longitudinal axis.

9. Electrical contact system (2) according to claim 8, characterized in that: the spring element (8) is designed as a leaf spring.

10. Electrical contact system (2) according to claim 8, characterized in that: the spring element (8) is configured such that each pair of contacts (3a, 3b) has a separate spring arm (20a, 20 b).

11. Electrical contact system (2) according to any of the preceding claims, characterized in that: the at least one movable contact (5a, 5b) extends through a corresponding mounting hole in the contact carrier (7) and forms a protrusion (32a, 32b) on its opposite side, and the at least one spring arm (20a, 20b) comprises a widened annular portion (29a, 29b) with a central recess (30a, 30b) in the region of the pressure portion (24a, 24b), the pressure portion (24a, 24b) extending transversely to the longitudinal axis of the contact carrier (7) when preloaded and being positioned in such a way that the protrusion (32a, 32b) is located on the opposite side of the contact (7) in the central recess (30a, 30 b).

12. Electrical contact system (2) according to claim 11, characterized in that: the at least one spring arm (20a, 20b) has two pressure portions (24a, 24b) at opposite positions of the widened annular portions (29a, 29 b).

13. Electrical contact system (2) according to any of the preceding claims, characterized in that: the slider (15) has a recess (35), and the second end (12) of the contact carrier (7) and the free end (21) of the second spring arm (23) of the spring element (18) protrude into the recess (35).

14. A switching device (1) comprising an electrical contact system (2) according to any one of claims 1 to 13.

15. The switching device (1) according to claim 14, further comprising an excitation coil and an armature (14) operatively connected to the slider (15), said slider (15) acting as a mechanical coupling element (15), characterized in that: the magnet coil generates a force as a result of the magnetic field generated by it, which is transmitted via the armature (14) and the mechanical coupling element to the electrical contact system (2), so that the latter is switched by the magnet coil.

16. The switching device (1) according to any one of claims 14 to 15, wherein: the switching device (1) is or comprises a relay.