阅读说明：本技术 具有形状记忆元件的电开关装置 (Electric switching device with shape memory element ) 是由 阿克塞尔·法比格 于 2020-04-24 设计创作，主要内容包括：一种开关装置(1),包括待布置在电气组件(2)上的载体元件(10)、可沿着操纵方向(B)向载体元件(10)运动的操纵元件(14)和布置在载体元件(10)上的形状可变的形状记忆元件(11),所述形状记忆元件与操纵元件(14)有效连接以使操纵元件(14)运动。弹性开关元件(13)与操纵元件(14)有效连接,并且具有至少一个可弹性偏转的支腿(131,132),开关元件(13)通过所述支腿支撑在载体元件(10)上,其中所述至少一个支腿(131,132)通过形状记忆元件(11)的形状变化和由此引起的操纵元件(14)的运动而向载体元件(10)可移动,以便与电接触元件(201,202,205,206)电接触。(A switching device (1) comprises a carrier element (10) to be arranged on an electrical component (2), an actuating element (14) which is movable in an actuating direction (B) toward the carrier element (10), and a shape-modifiable shape memory element (11) which is arranged on the carrier element (10) and is operatively connected to the actuating element (14) in order to move the actuating element (14). The elastic switching element (13) is operatively connected to the actuating element (14) and has at least one elastically deflectable leg (131, 132) by means of which the switching element (13) is supported on the carrier element (10), wherein the at least one leg (131, 132) is movable toward the carrier element (10) by a change in shape of the shape memory element (11) and a movement of the actuating element (14) caused thereby in order to make electrical contact with the electrical contact element (201, 202, 205, 206).)

1. Switching device (1) having a carrier element (10) to be arranged on an electrical component (2), an actuating element (14) which can be moved in an actuating direction (B) toward the carrier element (10), and a shape-modifiable shape memory element (11) which is arranged on the carrier element (10) and is operatively connected to the actuating element (14) for moving the actuating element (14), characterized by a resilient switching element (13) which is operatively connected to the actuating element (14) and has at least one resiliently deflectable leg (131, 132) by means of which the switching element (13) is supported on the carrier element (10), wherein at least one of the legs (131, 132) can be moved toward the carrier element (10) by a change in shape of the shape memory element (11) and a movement of the actuating element (14) caused thereby, in order to be in electrical contact with the electrical contact elements (201, 202, 205, 206).

2. The switching device (1) according to claim 1, wherein the carrier element (10) has two contact surfaces (101, 102) and the switching element (13) has two elastically movable legs (131, 132), wherein the legs (131, 132) are supported on one of the contact surfaces (101, 102), respectively.

3. The switching device (1) according to claim 2, wherein the legs (131, 132) are slidably movable with respect to the corresponding touch surfaces (101, 102), respectively.

4. The switching device (1) according to claim 2 or 3, wherein each leg (131, 132) is movable towards the carrier element (10) by a change in shape of the shape memory element (11) and a resulting manipulation of the manipulation element (14) for electrical contact with the corresponding electrical contact element (201, 202, 205, 206).

5. The switching device (1) according to any one of claims 2 to 4, wherein the carrier element (10) has an opening (100), wherein the contact surfaces (101, 102) are formed on mutually opposite sides of the opening (100).

6. The switching device (1) according to any one of the preceding claims, wherein the switching element (13) contacts the corresponding first contact element (205, 206) with the at least one elastically deflectable leg (131, 132) in a first switching position and contacts the corresponding second contact element (201, 202) in a second switching position which is moved relative to the first switching position.

7. The switching device (1) according to any one of the preceding claims, wherein the switching element (13) has and can be switched between a discrete first switching position and a discrete second switching position.

8. The switching device (1) according to claim 7, characterized in that the switching element (13) switches from a discrete first switching position to a discrete second switching position when the force exerted by the shape memory element (11) on the switching element (13) exceeds a predetermined threshold.

9. The switching device (1) according to any one of the preceding claims, wherein the actuating element (14) has an actuating head (140), by means of which the actuating element (14) is operatively connected to the switching element (13).

10. Switching device (1) according to claim 9, characterized in that said handling element (14) is connected to said shape memory element (11) with an end (141) remote from said handling head (140).

11. The switching device (1) according to any one of the preceding claims, wherein the shape memory element (11) has two ends (111, 112) which are each fixed relative to the carrier element (10) and have an inner section (110) extending between the ends (111, 112), by means of which inner section the shape memory element (11) is connected with the operating element (14).

12. The switching device (1) according to any one of the preceding claims, wherein the shape memory element (11) is configured as a wire or a sheet element.

13. The switching device (1) according to any of the preceding claims, characterized by activation means (12) electrically connected to said shape memory element (11) so as to generate an electric current through said shape memory element (11) and thereby cause a shape change on said shape memory element (11).

14. The switching device (1) according to claim 13, characterized in that the shape memory element (11) has a first shape in the currentless state and the switching element (13) occupies a first position, wherein the shape memory element (11) can be switched to a second shape by generating a current through the shape memory element (11) and the switching element (13) can be moved from the first position to a second position.

15. Assembly with a switching device (1) according to one of the preceding claims and an electrical assembly (2) on which the switching device (1) is arranged.

16. Assembly according to any one of the preceding claims, characterized in that the electrical assembly (2) has a circuit board (21) on which a carrier element (10) of the switching device (1) can be fixed.

17. Assembly according to claim 16, characterized in that the circuit board (21) has an introduction opening (20) into which the operating element (14) can be introduced in the operating direction (B).

18. Assembly according to claim 17, characterized in that an electrical contact element (201, 202) is arranged on at least one edge of the introduction opening (20) for electrical contact with at least one of the legs (131, 132) of the switching element (13) of the switching device (1).

Technical Field

The present invention relates to a switching device according to the preamble of claim 1.

Background

The switching device comprises a carrier element to be arranged on the electrical component, an actuating element which is movable in an actuating direction towards the carrier element, and a shape memory element which is arranged on the carrier element and can be varied in shape and is operatively connected to the actuating element for moving the actuating element.

Such switching devices, also called relays, can be switched between different electrical switching states. Such a switching device can be used, for example, as a safety relay in order to cause an emergency shutdown, for example, in the event of a failure of the power supply or of another system.

In such switching devices, there is a desire for simple, cost-effective retrofitting.

In this connection, there may be a desire, for example, for electrical components to be used with and without switching devices, wherein, for example, switching devices can be added to such electrical components as desired by the customer.

Furthermore, there is a desire for a switching device which can be realized with a relatively small installation space and weight, wherein the switching device is resistant to ageing, reliable in operation and, if necessary, can be checked for its ready state of operation.

A switching unit is known from DE 102015116394 a1, in which a spring-loaded pressure element is movable by a shape change on a shape memory alloy component.

From WO 01/99135 a1 a device is known in which a spring element with contacts arranged thereon can be moved by a shape memory alloy member in order to establish an electrical contact.

DE 19725001 a1 discloses a switching device in which the trip lever can be moved by means of a shape memory alloy part.

Disclosure of Invention

The object of the present invention is to provide a switching device which can be designed such that it can be retrofitted on an electrical component in a simple and cost-effective manner and has reliable operating characteristics for switching between different switching states.

This object is achieved by a body having the features of claim 1.

The switching device therefore has an elastic switching element which is operatively connected to the actuating element and has at least one elastically deflectable leg by means of which the switching element is supported on the carrier element, wherein the at least one leg can be moved toward the carrier element by a change in shape of the shape memory element and a movement of the actuating element caused thereby in order to make electrical contact with the electrical contact element.

The switching device is used to switch between different electrical switching states. The electrical contact is established by a switching element which is designed to be elastically adjustable and has the shape of a helical torsion spring, for example. The switching element can be adjusted by means of an actuating element, wherein the actuating element is operatively connected to the shape memory element in such a way that the actuating element is moved by a change in shape on the shape memory element and the switching element is thus switched from one switching state to the other switching state.

The shape memory element can, for example, electrically change its shape by means of a current flowing through the shape memory element. However, it is also conceivable and possible to activate the shape memory element in a different way, for example by heat.

For switching the switching device, the elastically deflectable leg of the switching element is in contact with or not in contact with one or more corresponding electrical contact elements. The electrical contact elements can be arranged, for example, on a carrier element or on an electrical component (for example, a circuit board of an electrical component on which the carrier element is arranged). By adjusting the switching element, the leg can be brought into contact with one or more contact elements or out of contact with the contact elements, so that an electrical connection can be established by switching of the switching element.

Since the switching element is elastically adjustable, the switching of the switching element can be effected by actuating the actuating element in the actuating direction against an elastic pretensioning force of the switching element, which leads to the resetting of the actuating element being able to take place or at least being able to be supported by the elastic pretensioning force of the switching element.

In one embodiment, the carrier element has two contact surfaces. The switching element can have two elastically adjustable legs, wherein each leg corresponds to one of the contact surfaces and is supported on the contact surface. The legs are slidably movable relative to the respective contact surfaces for switching the switching element between different switching states.

In particular, each leg can be adjusted by a change in shape of the shape memory element and the resulting actuation of the actuating element such that it comes into electrical contact with a corresponding electrical contact element on the carrier element or on the corresponding electrical component (for example when the actuating element is adjusted in the actuating direction) or out of contact with a corresponding electrical contact element (for example when the actuating element is adjusted against the actuating direction). Thus, an electrical connection can be established between the contact elements, for example, by means of the legs of the switching element. By bringing the legs out of contact with the contact elements, the electrical connection can be cancelled, which is caused by a shape change on the shape memory element, which can be used, for example, to provide a safety function, in particular an emergency shut-off in the event of a failure of the electrical system.

By the fact that the legs of the switching element can be moved in a sliding manner on the corresponding contact surfaces during the adjustment and come into sliding contact with the corresponding contact elements, it is possible to ensure a reliable switching operation even in the case of possibly contaminated or oxidized contact elements. Thus, the switching element slides on the contact element when switching in the direction of the on-state, which causes decontamination and wears away the oxide layer and thus reduces the oxide layer. Thus, by sliding the contact, it is possible to resist contamination effects or oxidation which may cause the contact to be damaged.

Because of the sliding movement of the legs, tolerance compensation can also be achieved in a simple manner without special measures having to be taken for this purpose.

In one embodiment, the carrier element has an opening into which the actuating element can be inserted. The contact surfaces can be curved, for example, and formed on the sides of the opening that face each other. The legs of the switching element can be moved over the contact surface, so that the switching element can be brought with its legs into or out of electrical contact with the corresponding contact element.

The actuating element can be inserted into the opening, for example, in an actuating direction, so that a switching element operatively connected to the actuating element is adjusted and a leg of the switching element is moved over the contact surface. The actuating element can have an actuating head, for example, by means of which the actuating element is operatively connected to the switching element. With the actuating head, the actuating element can be moved into the opening of the carrier element, so that the switching element can be adjusted relative to the carrier element.

The switching element can be embodied, for example, as a helical torsion spring, wherein the legs of the switching element project from the intermediate section. The switching element is preferably connected to the actuating head of the actuating element via the intermediate section in such a way that the actuating element acts on the intermediate section of the switching element and thereby adjusts the switching element.

The switching element can be wound, for example, from a spring wire, wherein the legs project from the central winding section. Alternatively, the spring element can be made of a spring plate, for example.

The switching element is preferably electrically conductive. Thus, an electrical connection between the contact elements can be established by the legs of the switching element and their contact with the corresponding contact elements.

In one embodiment, the switching device is designed as a normally open contact and is used to close the electrical contact. In this case, in a first switching position in which the switching element is in the initial state, for example when the shape memory element is not energized, the switching device is opened by the electrical contact elements not being contacted. Starting from the first switching position, the switching element can be switched into a second switching position in order to contact the electrical contact elements in the second switching position and thus to establish a connection between the electrical contact elements. In the second switching position, the switching device is therefore closed.

In an alternative embodiment, the switching device is designed as a normally closed contact and serves to open the electrical contact. In this case, in a first switching position in which the switching element is in the initial state, for example when the shape memory element is not energized, the switching device is closed by bringing the electrical contact element into contact with the switching element. Starting from the first switching position, the switching element can be switched into a second switching position, so that in the second switching position the electrical contact elements are no longer contacted and the connection between the electrical contact elements is thus broken. In the second switching position, the switching device is therefore open.

In a further embodiment, the switching device can also be designed as a so-called transfer relay. In this embodiment, the switching element contacts the first contact element with its at least one elastically deflectable leg in the first switching position. By switching the switching element from the first switching position into the second switching position, the second contact element can be contacted instead of the first contact element, so that the switching device switches from the first contact element onto the second contact element. For example, in the first switching position, a connection between a set of first contact elements can be established via two legs of the switching element. In the second switching position, the first contact is not contacted, but a connection between a set of second contact elements is established.

The switching element can be designed, for example, as a leg spring and can be adjusted, for example, continuously elastically (in the case of elastic tensioning of the switching element) by means of a shape memory element.

Alternatively, it is also conceivable and possible for the switching element to be designed as a bistable spring element, for example, which is designed, depending on the type of so-called clicker, for example, by means of a preformed sheet metal element. In this case, the switching element can be switched between a discrete first switching position and a discrete second switching position. This enables a configuration of, for example, the switching device such that switching takes place only under the condition that a predetermined force is provided by the shape memory element, so that in this way it is possible, for example, to adjust in which state the switching device switches.

This is based on the idea that the shape memory element usually does not change its shape abruptly, but continuously, when heated. The switching of the switching device is thus not performed abruptly, but rather within a predetermined time period. In order to achieve a sudden switching, a switching element of the type with a spring element having discrete switching positions can be used, which switches only when a certain force acts. The switching device is therefore switched only when a predetermined force is provided by the shape memory element (which is caused by the action of the shape memory element, for example, by changing its shape as a result of heating) in that the switching element is switched from a discrete first switching position to a discrete second switching position or vice versa.

In this way, the switching device can be configured such that, for example, an abrupt switching takes place in the event of a predetermined temperature being reached at the shape memory element.

In this case, the term "discrete first switching position" and "discrete second switching position" is to be understood to mean that the switching element cannot assume a (stable) intermediate position between the first switching position and the second switching position, but rather is always switched abruptly from the first switching position to the second switching position or vice versa during switching. The first switching position can preferably be designed in a stable manner. The second switching position can likewise be designed in a stable manner, it also being conceivable for the switching element to automatically switch back to the first switching position when the force effect is reduced and for this reason for the second switching position to be unstable, i.e. not designed to be automatically maintained.

In one embodiment, the switching element is switched from the discrete first switching position to the discrete second switching position when the force exerted on the switching element by the shape memory element exceeds a predetermined threshold value. In an initial state, for example when the shape memory element is not energized, the switching element exerts a pre-loading force on the shape memory element. If the shape memory element is, for example, energized or the temperature on the shape memory element is otherwise changed, and a force is thus exerted on the switching element, the switching element is only switched when the force exerted by the shape memory element exceeds a predetermined threshold value. In this case, the switching element suddenly switches from the first switching position to the second switching position. Thus, the spring force on the switching element suddenly yields to the force caused by the shape memory element.

The threshold value, which needs to be exceeded by the force exerted by the shape memory element to switch the switching element, can be adjusted, for example, by adjusting the pre-stress exerted by the switching element on the shape memory element. This adjustment can be performed, for example, by selecting a suitable switching element with a suitable spring characteristic value.

Additionally or alternatively, the elastic switching element is adjustable with respect to its spring force, so that the spring force caused by the switching element can be varied. In this way, the threshold value for switching the switching element can be adjusted.

In one embodiment, the actuating element is connected to the shape memory element at an end remote from the actuating head. The shape memory element thus acts on the end of the actuating element which is remote from the actuating head via which the actuating element is connected to the switching element. By means of a shape change on the shape memory element, the actuating element can be moved in an actuating direction in order in this way to bring the switching element into contact with one or more electrical contact elements or out of contact with a contact element.

In one embodiment, the shape memory element has two ends by which the shape memory element is secured to the carrier element. An inner section of the shape memory element extends between the ends, through which inner section the shape memory element is connected to the operating element, such that the operating element is moved in an operating direction when the shape of the shape memory element changes.

The shape memory element can be configured here, for example, as a wire or also as a sheet element. The shape memory element is made of a shape memory material, a so-called shape memory alloy (FGL for short), such as a nickel-titanium alloy (nitinol) or a nickel-titanium-copper alloy, a copper-zinc-aluminum alloy or a copper-aluminum-nickel alloy.

The shape memory element can be tensioned, for example, on the carrier element, such that the ends of the shape memory element are connected to the carrier element and the inner section extends across the actuating element. By means of the shape change, a length change effect can be caused in particular on the shape memory element, so that upon a change in the length of the shape memory element the actuating element is moved in the actuating direction towards the carrier element in order in this way to switch the switching element between the different switching states.

The shape change on the shape memory element may be caused, for example, by an activation device that generates a current through the shape memory element. The activation means may for example comprise a current source or a voltage source and be electrically connected to the shape memory element such that the shape memory element can be energized in order to cause a shape change, in particular a length change, on the shape memory element in this way.

The shape memory element can in this case have, in particular in the currentless state, a first shape which corresponds to a first position of the switching element. The first position of the switching element may, for example, correspond to an untouched position in which the legs of the switching element are not in electrical connection with the corresponding contact element. By energizing the shape memory element, the shape memory element can be transferred to a second shape, wherein in particular the length of the shape memory element is shortened and the second shape corresponds to the second position of the switching element. In the second position of the switching element, the legs of the switching element can in particular be brought into contact with corresponding electrical contact elements, so that an electrical connection between the contact elements is established, for example, by the switching element.

The shape memory element is electrically conductive. This aspect enables shape changes on the shape memory element. On the other hand, a measurement can be made, for example by measuring the resistance of the shape memory element, from which measurement information can be obtained, for example about the aging of the switching device, and with which measurement, for example, the functionality of the switching device can be checked and verified.

Furthermore, by means of such a resistance measurement on the shape memory element, a determination of the position of the actuating element can be carried out on the basis of the knowledge that the resistance is adjusted according to the current shape of the shape memory element and, therefore, the current shape of the shape memory element can be inferred on the basis of the resistance.

Furthermore, the correct electrical contact of one or more contact elements can be verified by such a resistance measurement.

In addition to or instead of activation by the activation device, the change in shape on the shape memory element can also be caused by a change in temperature, for example by the ambient temperature on the switching device. The shape memory element may be specifically designed and arranged such that when a predetermined limit temperature is exceeded, the shape memory element undergoes a shape change and thus causes a shape change on the shape memory element.

The switching device can be a component of an assembly, in the context of which the switching device is arranged on an electrical assembly, for example a circuit board of the electrical assembly, and is fixed to the circuit board, for example by means of suitable fixing elements. The circuit board can be designed such that the electrical component can be fitted with the switching device in a simple, cost-effective manner, but the electrical component can also be operated without the switching device in principle.

In one embodiment, the circuit board has an insertion opening, which is arranged in alignment with the opening of the carrier element, so that the actuating element can be inserted into the opening of the carrier element and into the insertion opening of the circuit board in the actuating direction. In this case, electrical contact elements may be arranged (respectively) on the edges of the insertion openings or on the edges of the insertion openings which lie opposite one another, with which the corresponding legs of the switching element can be brought into electrical contact. By moving the actuating element into the insertion opening, in particular, the legs of the switching element can be moved such that they make electrical contact with the electrical contact elements on the mutually opposite edges of the insertion opening, so that an electrical connection between the contact elements is established when the actuating element is actuated in this way.

However, the switching device can also be a component of the circuit board arrangement. In this case, the carrier element is formed, for example, by a circuit board, so that the carrier element is not provided as a separate component, but as an integral part of the circuit board.

Drawings

The inventive concept is explained in detail below with the aid of embodiments shown in the drawings. Wherein:

fig. 1 shows a schematic view of a switching device on a circuit board of an electrical assembly in an open position of a switching element;

fig. 2 shows a view of the switching device in the on position of the switching element;

FIG. 3 shows a view of one embodiment of a switching element in the form of a helical torsion spring;

fig. 4 shows a schematic view of an electrical contact element on a circuit board of an electrical assembly;

fig. 5 shows a view of a switching element connected to an actuating element according to another embodiment;

fig. 6 shows a view of the embodiment modified with respect to the embodiment according to fig. 1 and 2 in a first switching position of the switching element;

fig. 7 shows a view of the embodiment according to fig. 6 in a second switching position of the switching element;

fig. 8 shows a schematic view of a castanet-type switching element in a first switching position;

Fig. 9 shows the switching element according to fig. 8 in a second switching position;

fig. 10 shows a view of a further embodiment of the switching device in a first switching position of the switching element;

fig. 11 shows a view of the embodiment according to fig. 10 in a second switching position of the switching element;

fig. 12 shows a view of a further embodiment of the switching device in a first switching position of the switching element; and

fig. 13 shows a view of the embodiment according to fig. 12 in a second switching position of the switching element.

Detailed Description

Fig. 1 and 2 show an exemplary embodiment of a switching device 1 in a schematic representation, which has a carrier element 10, a shape memory element 11 arranged on the carrier element 10, an activation device 12 for activating the shape memory element 11, a switching element 13 and an actuating element 14.

The carrier element 10 is arranged on the circuit board 21 of the corresponding electrical component 2 and is fixedly connected to the circuit board 21 by means of the fastening element 15. By switching of the switching element 13, an electrical connection between the electrical contact elements 201,202 on the circuit board 21 can be established or cancelled.

In the exemplary embodiment shown in fig. 1 and 2, the shape memory element 11 is fastened with the ends 111,112 to the carrier element 10 by means of the contact means 121, 122 and extends between the ends 111,112 with the inner portion 110. The shape memory element 11 is connected to the actuating element 14 via an inner section 110, so that the actuating element 14 can be moved by a shape change on the shape memory element 11 in an actuating direction B (perpendicular to the plane of extension of the carrier element 10).

The operating element 14 is formed in the manner of a plunger and is connected with one end 141 to the shape memory element 11. The actuating element 14 is operatively connected to the switching element 13 via an actuating head 140 remote from the end 141, so that the switching element 13 can be moved by moving the actuating element 14 in the actuating direction B.

The switching element 13 is elastically displaceable and is configured, for example, as a helical torsion spring. As shown in the illustration in fig. 3, the switching element 13 has, for example, a central section 130, from the two sides of which legs 131, 132 project.

The switching element 13 may be made of a spring wire, for example. In this case, the intermediate section 130 is wound, for example, in a plurality of turns, wherein the legs 131, 132 can be elastically deflected toward the intermediate section 130.

In an alternative embodiment, the switching element 13 can also be made of a spring plate, for example, wherein in this case the switching element 13 extends in the form of a strip and is preferably not wound (annularly) in its central section 130.

The actuating element 14 is connected to the central section 130 of the switching element 13 via an actuating head 140. When the actuating element 14 is moved in the actuating direction B, the actuating element 14 therefore acts on the switching element 13 and moves the middle section 130 of the switching element 13 in the actuating direction B toward the carrier element 10.

As can be seen from fig. 1 and 2, an opening 100 is formed in the carrier element 10, which opening is aligned with the insertion opening 20 in the circuit board 21, so that when the actuating element 14 is moved in the actuating direction B, the actuating head 140 is inserted into the opening 100 and can be lowered into the insertion opening 20 of the circuit board 21, as can be seen in the transition from fig. 1 to fig. 2.

The legs 131,132 of the switching element 13 are supported (in the section according to fig. 1 and 2) on curved contact surfaces 101,102 formed on both sides of the opening 100 of the carrier element 10 and are slidably movable on these contact surfaces 101, 102. When the actuating element 14 is moved in the actuating direction B, the legs 131,132 slide along the contact surfaces 101,102 in such a way that the angle α between the legs 131,132 becomes smaller and the legs 131,132 come into contact with the contact elements 201,202 on both sides of the insertion opening 20 of the circuit board 21, as can be seen in the transition from fig. 1 to fig. 2.

By the legs 131,132 being moved in a sliding manner along the contact surfaces 101,102 in the direction of the switched-on position (fig. 2) during switching of the switching device 1 and furthermore being in sliding contact with the contact elements 201,202, possible contamination or oxidation layers on the legs 131,132 and/or the contact elements 201,202 are repelled and thus at least reduced, so that reliable electrical switching characteristics can be achieved.

When moving from the off position (fig. 1) into the on position (fig. 2), the legs 131, 132 move resiliently relative to each other with the switching element 13 resiliently tensioned. The resetting of the switching element 13 together with the actuating element 14 from the on position (fig. 2) into the off position (fig. 1) thus takes place automatically or at least assisted by an elastic resetting force on the switching element 13.

In the switched-on position (fig. 2), the electrical contact elements 201,202 on the circuit board 21 of the electrical assembly 2 are electrically connected to one another via the switching element 13. The switching element 13 is made of an electrically conductive material in this case, so that an electric current can flow between the contact elements 201,202 via the switching element 13.

The contact elements 201,202 are formed on mutually opposite edges of the opening 20, as can be seen schematically in fig. 4. Each contact element 201,202 is connected, for example, to a corresponding conductor circuit 203,204 on the circuit board 21, so that an electrical connection between the conductor circuits 203,204 is established via the switching element 13 in the on position, which connection can however be interrupted by switching the switching element 13 into the off position.

The movement of the actuating element 14 and thus of the switching element 13 is effected by the shape memory element 11 and the shape change induced on the shape memory element 11. The shape memory element 11 may be formed of, for example, a metal wire or a metal sheet, and is made of a shape memory alloy. The shape memory element 11 can be activated here, for example, by means of the activation device 12, by means of the current source 120 and the contact devices 121, 122, which cause a current through the shape memory element 11, which leads to heating and thus to a change in shape on the shape memory element 11, in particular to a shortening for the displacement of the actuating element 14 from the off position (fig. 1) in the direction of the on position (fig. 2) of the switching element 13.

In the currentless state, the shape memory element 11 assumes an elongated shape corresponding to fig. 1. In the exemplary embodiment shown, upon activation by an electric current, a shortening of the shape memory element 11 and thus a displacement of the actuating element 14 in the actuating direction B takes place, as can be seen in the transition from fig. 1 to fig. 2.

Additionally or alternatively, the activation and the shape change on the shape memory element 11 can also be effected by a temperature change, for example by the ambient temperature on the switching device 1. The shape memory element 11 may be designed in particular such that, when a temperature is exceeded, a change in shape is caused and thus a switching off of the switching device 1 is caused.

The switching device 1 can, for example, provide a safety device which, in the event of a superordinate system failure, brings about an emergency shutdown of the electrical component 2 in that the switching device 1 is switched from its on position (fig. 2) into its off position (fig. 1).

As in the example according to fig. 1 and 2, the switching device 1 can be designed as a normally open contact which closes when the shape memory element 11 is activated. Alternatively, however, the switching device 1 can also be designed as a normally closed contact which opens when the shape memory element 11 is activated, for example when a current flows through the shape memory element 11.

By measuring the electrical resistance on the shape memory element 11, the current shape of the shape memory element 11 can be inferred. Thus, by measuring the resistance on the shape memory element 11, the currently occupied position of the switching device 1 can be deduced, wherein possible aging effects can additionally be monitored, for example, on the shape memory element 11.

The actuating element 14 can also be made of an electrically conductive material. This enables, for example, also checking the effectiveness of the electrical contact of the contact elements 201,202 by measuring the electrical resistance on the shape memory element 11.

The switching device 1 may be mounted as a whole on the corresponding circuit board 21. The provision of only electrical contacts on the circuit board 21 in this respect enables simple attachment of such a switching device 1 to the electrical component 2.

The electrical contacting of the contact elements 201,202 can be effected directly via the legs 131, 132 of the switching element 13. However, it is conceivable and possible, as shown in the modified exemplary embodiment according to fig. 5, to provide an additional contact element 16 on the switching element 13, which contact element can be brought into electrical contact with the contact elements 201,202 by means of the sections 161, 162. In this case, when the switching device 1 is switched on, a current can flow between the contact elements 201,202, preferably via the contact element 16. The contact element 16 can be made of a strip-shaped material (having a larger conductor cross section than the switching element 13), for example, which makes it possible to increase the current-carrying capacity of the switching device 1.

The contact elements 16 are elastically deformable, so that the contact elements 16 are deformed together when the switching element 13 is moved. However, it is also conceivable and possible for the contact element 16 itself to be formed rigidly, so that when the switching element 13 is moved, the contact element 16 is moved in the actuating direction B toward the contact elements 201,202, but is not deformed in this case.

In the exemplary embodiment according to fig. 1 and 2, the switching device 1 is designed as a normally closed contact or a normally open contact, so that the contact elements 201,202 open or close depending on the position of the switching element 13.

Alternatively, as shown in one exemplary embodiment in fig. 6 and 7, the switching device 1 can also be designed as a so-called transfer relay, in which the switching element 13 contacts the first contact elements 205,206 in the first switching position (fig. 6) and the second contact elements 201,202 in the second switching position (fig. 7). Thus, an electrical connection between the contact elements 205,206 is established in the first switch position. In the second switching position, the switching device 1 is switched for contacting further contacts 201,202, so that the switching element 13, in a position-dependent manner, contacts and closes some contacts 205,206 or further contacts 201, 202.

In the exemplary embodiments according to fig. 1 and 2 and in the exemplary embodiments according to fig. 6 and 7, the fastening element 15 can serve not only to mechanically fasten the carrier element 10 to the circuit board 21, but also to establish an electrical connection for the control circuit (activation device 12) or the load circuit (contacts 201,202,205, 206).

The carrier element 10 does not have to be formed separately from the printed circuit board 21 and mechanically connected to the printed circuit board 21, but can also form part of the printed circuit board 21 and thus be formed by the printed circuit board 21 itself. The switching device 1 therefore does not have to be formed as a component of an electronic assembly separate from the circuit board 21, but can be an integral part of the assembly.

As is shown schematically in fig. 8 and 9, the switching element 13 can in one embodiment be designed as a spring element which can be switched between discrete switching positions, for example in the form of a spring plate in the form of a snap disk (also referred to as flip disk). Thus, when the switching device 1 is switched, the switching element 13 is not moved continuously, but abruptly between its discrete positions according to fig. 8 and 9, so that the switching element 13 electrically contacts the first contact elements 205,206 (fig. 8) in the first switching position and the second contact elements 201,202 (fig. 9) in the second switching position, for example.

Thus, in case the shape memory element 11 tends to deform, for example due to heating on the shape memory element 11, a continuous switching action over time on the switching element 13 does not occur, but the switching element 13 switches abruptly. The switching element 13 having a discrete position is to be understood in that the switching element 13 cannot assume a (stable) intermediate position between the discrete first switching position according to fig. 8 and the discrete second switching position according to fig. 9, but rather switches abruptly if the force action on the switching element 13 is sufficient.

Thus, for example, when the shape memory element 11 starts to heat up, no switching of the switching device 1 takes place first. The switching element 13 is switched from its discrete first switching position (fig. 8) into the discrete second switching position (fig. 9) only when the deformation caused on the shape memory element 11 by heating and the resulting force exceed the limit force required for the switching of the switching element 13.

This enables, for example, a relatively precise setting of the temperature at which the switching device 1 switches when applied to the shape memory element 11. The switching point of the switching device 1 can therefore be preset by the configuration of the switching element 13.

Fig. 10 and 11 show an embodiment in which the switching element 13 is realized in the form of a spring plate in the form of a clicker (flip-chip) which is switchable between discrete positions.

In this exemplary embodiment, the switching element 13 is fixedly connected to the actuating element 14 at the intermediate section 130 and is switchable between a first switching position (fig. 10) and a second switching position (fig. 11) along the actuating direction B via a shape memory element 11 coupled to the actuating element 14. The legs 131,132 of the switching element 13 form an angle α with the actuating element 14 in the first switching position₁And in electrical contact with the outer contact elements 205,206, as can be seen in fig. 10. When the actuating element 14 is actuated in the actuating direction B, the position of the limbs 131,132 relative to the actuating element 14 changes such that the limbs 131,132 occupy a (smaller) angle α relative to the actuating element 14₂As can be seen from fig. 11. In this case, the legs 131,132 move on the contact surfaces 101,102 of the carrier 10 of the switching device 1 and come into contact with the inner contact elements 201, 202 in an electrical contact manner, while electrical contact with the contact elements 205,206 is released.

Since in the exemplary embodiment shown in fig. 10 and 11 the switching element 13 is designed as a spring plate according to the flip-chip method, the switching element 13 can be switched abruptly between the discrete switching positions according to fig. 10 and 11. If, as a result of the heating on the shape memory element 11, a force in the actuating direction B is applied to the actuating element 14 by the shape memory element 11, the switching element 13 is only switched from the first switching position according to fig. 10 into the second switching position according to fig. 11 when the force caused by the shape memory element 11 exceeds a threshold force and is large enough to overcome the force required for the abrupt switching of the switching element 13. This force can for example only be reached at a predetermined temperature on the shape memory element 11, so that the temperature at which the switching device 1 switches abruptly can be defined on the basis of a suitable selection of the switching element 13.

In the embodiment shown, the shape memory element 11 is connected by the ends 111, 112 to contact means 121, 122 for connecting the carrier element 10 of the switching device 1 to a circuit board, which forms the electrical component 2, by means of the fixing element 15. The fixing element 15 therefore serves not only to mechanically fix the switching device 1 on the circuit board 2, but also to make electrical contact with the shape memory element 11 of the activation device 12.

Additionally or alternatively, the contact elements 201, 202, 205, 206 may also serve for electrical contacting and additionally also for mechanically fixing the switching device 1 on the circuit board 2.

The shape memory element 11 can be activated by the activation device 12, in particular by a current source 120 of the activation device 12, by means of a current. In addition, the shape memory element 11 can also be activated as a result of the ambient temperature of the switching device 1, so that the switching device 1 switches automatically if a temperature is exceeded. The shape memory element 11 may, for example, be thermally coupled to a housing of the switching device 1 or to the electrical component 2 in order to receive a temperature at the switching device 1 and/or the component 2.

In contrast to the exemplary embodiments according to fig. 1 and 2 and fig. 6 and 7, in the exemplary embodiment according to fig. 10 and 11 the openings 100 in the carrier element 10 are merely configured as recesses and do not extend through the carrier element 10. The circuit board 2 does not have an inlet opening in this embodiment (corresponding to the inlet opening 20 in the embodiment according to fig. 1 and 2 and in the embodiment according to fig. 6 and 7).

In a further embodiment, which is shown in fig. 12 and 13, unlike the embodiment according to fig. 10 and 11, no openings 100 are formed in the carrier 10.

Four contact elements 201,202, 205, 206 are arranged on the carrier 10, wherein a switching element 13 in the form of a leg spring 131, 132 is in electrical contact with the two outer contact elements 205, 206 in a first switching position (fig. 12) and is in electrical contact with the inner contact elements 201,202 when switched into a second switching position (fig. 13) via the legs 131, 132. The inner contact elements 201,202 project from the surface of the carrier element 10 facing the switching element 13 and are in turn designed to be raised relative to the contact elements 205, 206, so that in the second switching position the electrical contact of the switching element 13 with the outer contact elements 205, 206 is cancelled. In this case, no sliding on the touch surface occurs (as is the case on the touch surfaces 101, 102 in the previously described embodiment).

In this embodiment, the switching element 13 is also actuated by the shape memory element 11, in which embodiment the switching element 13 is connected to the actuating element 14 via a wound intermediate section 130, wherein the shape memory element 11 can be activated electrically or by a change in temperature, for example.

The basic idea of the invention is not limited to the embodiments described above but may also be implemented in other ways.

Switching devices of the type described here can be used in particular as safety devices for providing emergency shutdown. However, such a switching device may be generally used as a switch that switches between an on state and an off state.

Description of the reference numerals

1 switching device

10 carrier element

100 opening

101, 102 touch surface

11 shape memory element

110 inner section

111, 112 ends

12 activation device

120 current source

121, 122 contact device

13 switch element (spiral torsion spring)

130 middle section

131, 132 support leg

14 operating element

140 operating head

141 end portion

15 fixing element

16 contact element

161, 162 section

2 electric assembly

20 introduction opening

201, 202 contact element

203, 204 conductor circuit

205, 206 contact element

21 circuit board

Angle alpha, alpha 1, alpha 2

B steering direction