EP2545622B1 - Surge protection element - Google Patents

Description

The invention relates to an overvoltage protection element.

Overvoltage protection elements are often used to protect electrical and electronic equipment against overvoltages that can be transmitted through the electrical supply network. Such overvoltages can be caused, in particular, by lightning discharges which, for example, couple into the infrastructure of the supply networks via grounding systems.

Such an overvoltage protection element is for example from the EP 0 987 803 B1 in the form of an overvoltage protection device for electrical installations, to which the device is connected by means of connecting means comprising at least two connectors, the device further comprising a lightning protection cell, the first pole of which is directly connected to a first one of the connectors. A second pole of the cell is connected to a first conductor section. Furthermore, the device has a second conductor section, which is directly connected to a second of the connectors. In addition, the device has fuses to maintain a stable slide in a working position of the device in electrical contact with the conductor portions, the means serving to permanently push the slider to an open position of the device in which the slider is not in contact with the two conductor sections has more.

However, such an overvoltage protection element is only for relatively low-energy impulse loads and the resulting lower dynamic current forces suitable. The dynamic current forces are largely determined by the pulse shape and in part by the amplitude level of the surge current.

Another overvoltage protection device which is considered to be the closest prior art is known from the WO 2005/112 050 A1 known. It comprises a varistor whose one pole is directly connected to a contact of the overvoltage protection device. The other pole of the varistor is connected to a connection means. The overvoltage protection device further comprises a connecting element, which is connected to the contact element. The connecting element can be transferred between a first and a second position, wherein in the first position the connecting element for electrically connecting the connecting means to a second contact of the overvoltage protection device bears against the connecting means and in the second position the connecting element is arranged at a distance from the connecting means. In the first position, a thermally separable connection is provided between the connecting element and the connecting means.

The invention is therefore based on the object to provide an overvoltage protection element, by means of which both surge currents with high amplitudes (typically 8/20 μs pulse) as they can arise in switching operations as well as high-energy partial lightning currents (typically 10/350 μs pulse ) can be safely derived.

The object is achieved by the features of claim 1. Advantageous embodiments of the invention are specified in the dependent claims.

The overvoltage protection element according to the invention has a contact tongue and a contact element arranged at a distance from the contact tongue, wherein a connecting element is provided, which can be converted into a first position and into a second position, wherein in the first position the connecting element for electrically connecting the contact tongue to the contact element is disposed on the contact tongue and on the contact element and in the second position, the connecting element is arranged spaced from the contact tongue and the contact element, wherein in the first position between the connecting element and the contact tongue and between the connecting element and the contact element is provided a thermally separable connection, wherein in the first position, the connecting element at least partially surrounds the contact tongue and / or the contact element.

The connecting element serves to be able to produce a contact between the contact tongue and the contact element spaced apart from the contact tongue, wherein in the contacting state, in the first position of the connecting element, the connecting element bears against a surface of the contact tongue and against a surface of the contact element the connecting element is preferably at least partially adapted to the contour of the contact tongue and the contour of the contact element. The surface of the contact tongue and the surface of the contact element against which the connection element abuts can lie in a plane relative to one another such that the connection element overlaps the surface of the contact tongue and the surface of the contact element like a kind of bridge, or the surfaces can face one another, so that the connecting element is arranged between the contact tongue and the contact element. On the adjoining surfaces of the connecting element with the contact tongue and on the adjoining surfaces of the connecting element with the contact element, a thermally separable connection, for example in the form of a solder, is provided for connecting the connecting element to the contact tongue and the connecting element to the contact element. The thermally separable connection is preferably applied over a large area between the connecting element and the contact tongue and the connecting element and the contact element. In this case, a larger current amplitude can be transmitted over a large area contact due to the larger cross section. In addition, a large contact surface ensures high stability of the connection.

Achieved in an overload case of Überspannungsschtzelements the thermally separable connection a temperature which is equal to the melting temperature, the thermally separable connection melts, so that the connecting element is released and from the first position to a second position in which the connecting element of the Contact tongue and the contact element is arranged spaced apart, moves. The movement of the connecting element is preferably realized in that the connecting element is connected to a prestressed spring element, which is activated upon melting of the thermally separable connection and moves the connecting element away from the contact tongue and the contact element.

The overvoltage protection element according to the invention is characterized in that in the first position the connecting element at least partially surrounds the contact tongue and / or the contact element. This makes it possible to achieve a particularly high mechanical stability of the connection between the connecting element and the contact tongue and / or the connecting element and the contact element in the first position, so that it is possible to derive surge currents with dynamic energetic pulse shapes via the overvoltage protection element this is possible with the surge voltage protection elements known from the prior art. The connecting element may for example be U-shaped, so that the connecting element at least partially surrounds one or more edge regions of the contact tongue and / or the contact element.

According to an advantageous embodiment of the invention, a clearing element is provided, wherein the clearing element between the contact tongue and the contact tongue spaced apart contact element is arranged to be movable. The clearing element is used in a separation of the contact between the contact element and the contact tongue in case of overload of the overvoltage protection element to remove the remaining in the gap between the contact element and the contact tongue remnants of the thermally separable connection to ensure that between the contact blade and the contact element no electrical Compound can exist more. For this, the reaming element is preferably moved or moved during a movement of the connecting element from the first position to the second position within the gap between the contact tongue and the contact element in order to clean the gap, preferably from the thermally separable connection. Preferably, the clearing element is thereby moved from the contact element to the contact tongue within the gap in order to achieve the most complete removal of the remainders of the thermally dissociable compound in the gap. The clearing element can be designed, for example, as a clearing finger or as a clearing blade. If the clearing element is designed as a clearing finger, the clearing element is moved in a separation of the contacting by transferring the connecting element from the first position to the second position within the gap, wherein upon reaching the second position, the clearing element from the gap between the contact tongue and the Contact element is moved out. If the clearing element is designed as a dozer blade, so preferably remains the clearing element in the second position of the connecting element within the gap between the contact element and the contact tongue and thus serves as a shield to at the separation of the Contacting any resulting arcs can interrupt.

The reaming element is preferably arranged on the connecting element. The reaming element can be integrally connected to the connecting element or else arranged and attached as a separate component to the connecting element. If the broaching element is arranged on the connecting element, then the broaching element preferably performs the same movement as the connecting element, so that no separate movement mechanism has to be provided for the broaching element, but the broaching element, for example, also moves by means of the spring element, which is connected to the connecting element can be.

Alternatively, it is preferably provided that the clearing element is movable independently of the connecting element. In this embodiment, for example, after the connecting element has been moved from the first position to the second position, the clearing element can be moved into the gap between the contact tongue and the contact element. As a result, a decoupling of the movement of the connecting element and the Räumelements is possible. To realize the movement of the clearing element, for example, a second spring element or a lever may be provided which is connected to the broaching element.

Further, it is preferably provided that the clearing element is formed of a non-conductive material. Preferably, the clearing element is formed of a plastic material. By forming the Räumelements from a non-conductive material can possibly resulting in the separation of the contact between the contact tongue and the contact element in case of overload arcs are interrupted.

According to a further advantageous embodiment of the invention, the connecting element is formed trough-shaped. The connecting element is preferably trough-shaped, if the contact element and the contact tongue are arranged parallel to each other and the surface of the contact tongue and the surface of the contact element, which contacts the connecting element, so that the connecting element at least partially between the contact tongue and the contact element is arranged. If the connecting element has a trough-shaped configuration, the connecting element itself can remove the thermally separable connection from the gap between the contact tongue and the contact element during the process from the first position to the second, without the need for an additional clearing element. Such a trained connecting element can thus fulfill two functions simultaneously, on the one hand in the first position the production of an electrical contact between the contact element and the contact tongue and on the other the function as a clearing element for cleaning the gap between the contact element and the contact tongue at a separation of electrical contacting and movement of the connecting element from the first position to the second position.

The thermally separable compound is preferably formed from a material which can be converted into a viscous state when a melting temperature is exceeded. This can prevent the thermal separable compound when melting during the separation of the contact drips uncontrolled. The thermally separable compound is preferably formed of a non-eutectic material, so that the material of the thermally dissociable compound initially assumes a tough or mushy phase during melting.

The invention will be explained in more detail with reference to the accompanying drawings with reference to preferred embodiments.

Fig. 1

eine schematische Darstellung eines Überspannungsschutzelements gemäß einer ersten Ausführungsform in einem kontaktierenden Zustand;

Fig. 2

eine schematische Schnittdarstellung eines Ausschnitts des in Fig. 1 gezeigten Überspannungsschutzelements;

Fig. 3

eine schematische Darstellung des Überspannungsschutzelements gemäß der ersten Ausführungsform in einem nicht-kontaktierenden Zustand;

Fig. 4

eine schematische Schnittdarstellung eines Ausschnitts des in Fig. 3 gezeigten Überspannungsschutzelements;

Fig. 5

eine schematische Darstellung eines Überspannungsschutzelements gemäß einer zweiten Ausführungsform in einem kontaktierenden Zustand;

Fig. 6

eine schematische Schnittdarstellung eines Ausschnitts des in Fig. 5 gezeigten Überspannungsschutzelements;

Fig. 7

eine schematische Darstellung des Überspannungsschutzelements gemäß der zweiten Ausführungsform in einem nicht-kontaktierenden Zustand;

Fig. 8

eine schematische Schnittdarstellung eines Ausschnitts des in Fig. 7 gezeigten Überspannungsschutzelements;

Fig. 9

eine schematische Darstellung eines Überspannungsschutzelements gemäß einer dritten Ausführungsform in einem kontaktierenden Zustand;

Fig. 10

eine schematische Draufsicht auf das in Fig. 9 gezeigte Überspannungsschutzelement;

Fig. 11

eine Schnittdarstellung der in Fig. 10 gezeigten Darstellung des Überspannungsschutzelements gemäß der dritten Ausführungsform;

Fig. 12

eine schematische Darstellung des Überspannungsschutzelements gemäß der dritten Ausführungsform in einem nicht-kontaktierenden Zustand;

Fig. 13

eine schematische Darstellung eines Überspannungsschutzelements gemäß einer vierten Ausführungsform in einem kontaktierenden Zustand;

Fig. 14

eine schematische Draufsicht auf das in Fig. 13 gezeigte Überspannungsschutzelement;

Fig. 15

eine Schnittdarstellung der in Fig. 14 gezeigten Darstellung des Überspannungsschutzelements gemäß der vierten Ausführungsform; und

Fig. 16

eine schematische Darstellung des Überspannungsschutzelements gemäß der vierten Ausführungsform in einem nicht-kontaktierenden Zustand.

Show it:

Fig. 1

a schematic representation of an overvoltage protection element according to a first embodiment in a contacting state;

Fig. 2

a schematic sectional view of a section of the in Fig. 1 shown overvoltage protection element;

Fig. 3

a schematic representation of the overvoltage protection element according to the first embodiment in a non-contacting state;

Fig. 4

a schematic sectional view of a section of the in Fig. 3 shown overvoltage protection element;

Fig. 5

a schematic representation of an overvoltage protection element according to a second embodiment in a contacting state;

Fig. 6

a schematic sectional view of a section of the in Fig. 5 shown overvoltage protection element;

Fig. 7

a schematic representation of the overvoltage protection element according to the second embodiment in a non-contacting state;

Fig. 8

a schematic sectional view of a section of the in Fig. 7 shown overvoltage protection element;

Fig. 9

a schematic representation of an overvoltage protection element according to a third embodiment in a contacting state;

Fig. 10

a schematic plan view of the in Fig. 9 shown overvoltage protection element;

Fig. 11

a sectional view of in Fig. 10 shown representation of the overvoltage protection element according to the third embodiment;

Fig. 12

a schematic representation of the overvoltage protection element according to the third embodiment in a non-contacting state;

Fig. 13

a schematic representation of an overvoltage protection element according to a fourth embodiment in a contacting state;

Fig. 14

a schematic plan view of the in Fig. 13 shown overvoltage protection element;

Fig. 15

a sectional view of in Fig. 14 shown representation of the overvoltage protection element according to the fourth embodiment; and

Fig. 16

a schematic representation of the overvoltage protection element according to the fourth embodiment in a non-contacting state.

Fig. 1 - 4th show an overvoltage protection element according to a first embodiment. The overvoltage protection element is usually arranged in a housing, not shown here. The overvoltage protection element has a contact tongue 10 and a contact element 12 arranged at a distance from the contact tongue 10. To produce an electrical contact between the contact tongue 10 and the contact element 12, a connecting element 14 is provided, which in a contacting state, such as in Fig. 1 and Fig. 2 shown, on the contact element 12 and the contact tongue 10 is present. In the first position, the connecting element 14 lies with one of its side surfaces 22 on a surface of the contact tongue 10 and a surface of the contact element 12 arranged in a plane to the surface of the contact tongue 10. The contact tongue 10 and the contact element 12 are thus in the first position on the same side surface 22 of the connecting element 14 at. The contact surface decisively determines the maximum amplitude of the surge currents that can be dissipated. Between the side surface 22 of the connecting element 14 and the surface of the contact tongue 10 pointing in the direction of the side surface 22 and the surface of the contact element 12 facing in the direction of the side surface 22 is a thermally separable connection, preferably in the form of a solder, which the connecting element 14 in the first position on the contact element 12 and the contact tongue 10 is fixed and which in case of overload of the overvoltage protection element melts upon reaching a temperature equal to the melting temperature of the material of the thermally separable connection, so that the fixation is released and the connecting element 14 are moved away from the contact tongue 10 and the contact element 12 in the direction of the second position can, like this in FIG. 3 and FIG. 4 can be seen. The movement of the connecting element 14 via a biased spring element 18, which is connected via a movable carriage 20 with the connecting element 14.

The connecting element 14 is formed in this embodiment such that it encloses the edge regions of the contact element 12 and the contact tongue 10 by angled side parts 16 are provided on the connecting element 14. As a result, a particularly high mechanical stability in the connection between the connecting element 14 and the contact tongue 10 and the contact element 12 in the contacting state can be achieved, as a result of which the overvoltage protection element can be used for particularly high-energy surge currents.

On the side surface 22 of the connecting element 14, a clearing element 24 is arranged in the form of a Räumfingers, by means of which after separation of the contact between the contact tongue 10 and the contact element 12, the gap 42 between the contact tongue 10 and the contact element 12 of Remains of the thermally dissociable compound can be released. In the first position, in the contacting state, the broaching element 24, as in Fig. 1 and Fig. 2 can be seen, arranged in the gap 42 between the contact tongue 10 and the contact element 12. Upon movement of the connecting element 14 from the first position to the in FIG. 3 and FIG. 4 shown second position, the clearing element 24 is moved within the gap 42, starting from the contact element 12 in the direction of the contact tongue 10 and then removed from the gap 42 or moved out.

In Fig. 5-8 a second possible embodiment of the overvoltage protection element according to the invention is shown. The overvoltage protection element shown here corresponds essentially to the in Fig. 1 - 4th shown overvoltage protection element, in which case the clearing element 24 is formed as a dozer blade, which also in the second position of the connecting element 14, as in FIGS. 7 and 8 shown in the gap 42 between the contact tongue 10 and the contact element 12 remains, so that the reaming member 24 serves as a protective element to prevent the formation of arcs in the separation between the contact blade 10 and the contact element 12. In this second embodiment shown here, the clearing element 24 is arranged on the connecting element 14 via a hinge element 26 as a separate component.

Fig. 9 - 12 show a third possible embodiment of the overvoltage protection element according to the invention, wherein in this case the contact tongue 10 and the contact element 12 are arranged opposite each other, parallel to each other, so that in the first position at least a portion of the connecting element 14 between the contact tongue 10 and Contact element 12 is arranged, wherein the connecting element 14, the contact tongue 10 in a U-shape surrounds, as shown in Fig. 10 and Fig. 11 can be seen, and with an angled wall 28 in addition, the contact element 12 partially surrounds. A thermally separable connection is at the interfaces 34, 36, as in FIG Fig. 11 shown, between the connecting element 14 and the contact tongue 10 and the contact element 12 is provided.

The connecting element 14 is in this case trough-shaped, so that the connecting element 14 itself in the process from the first position, in Fig. 9 - 11 shown in the second position, in Fig. 12 shown, the thermally releasable connection from the gap 42, as in Fig. 12 can be seen, between the contact tongue 10 and the contact element 12 can remove, without the need for an additional clearing element would be necessary. In the second position, the connecting element 14 is completely removed from the gap 42 between the contact tongue 10 and the contact element 12.

The connecting element 14 is in this case also preferably connected to a biased spring element, not shown here, in order to realize the movement of the connecting element 14 from the first position to the second position.

The thermally separable connection is formed, in particular in this embodiment, preferably from a material which can be converted into a viscous state when a melting temperature is reached. This can prevent the thermally dissociable compound from melting during the separation of the Contact drops uncontrollably. The thermally separable compound is preferably formed of a non-eutectic material, so that the material of the thermally dissociable compound initially assumes a tough, mushy phase during melting.

In Fig. 13 - 16 A fourth possible embodiment of the overvoltage protection element according to the invention is shown, wherein the overvoltage protection element shown here essentially corresponds to that in FIG Fig. 9 - 12 In the fourth embodiment shown here, the contact element 12 has a first contact leg 30 and a second contact leg 32 guided parallel thereto. The trough-shaped connecting element 14 can be arranged between the first contact leg 30 and the second contact leg 32 of the contact element 12 in the first position, as in FIG Fig. 13 - 15 it can be seen, wherein the connecting element 14 surrounds the contact tongue arranged between the first contact leg 30 and the second contact leg 32 in a U-shape. The thermally separable connection is arranged substantially at four boundary surfaces 34, 36, 38, 40 between the contact tongue 10, the contact legs 30, 32 and the connecting element 14, so that solely by the increased number of interfaces 34, 36, 38, 40 to which a thermally separable connection is provided, a higher mechanical stability of the contact can be achieved and thereby more energy-rich surge currents can be derived. In addition, the contact area is increased, so that surge currents can be derived with higher amplitudes. This advantage is reinforced by the distribution of the current to the two legs 30, 32 arranged parallel to one another.

With the in Fig. 13 - 16 shown overvoltage protection element particularly high-energy surge currents can be transmitted. If the parallel arranged contact legs 30, 32 at the same time, in the same direction flows through current, so the contact legs 30, 32 attract each other by the magnetic field accompanying the current flow. As a result, a lower mechanical load acts on the thermally separable connections provided at the interfaces 34, 36, 38, 40 when a surge current flows, since the attracting contact legs 30, 32 press the connecting element 14 against the contact tongue 10, thereby providing mechanical support the thermally dissociable compound in the interfaces 34, 36, 38, 40 can be realized and thereby the interfaces 34, 36, 38, 40 itself can be dimensioned smaller or the amount of applied to the interfaces 34, 36, 38, 40 thermally dissociable compound can be reduced.

LIST OF REFERENCE NUMBERS

contact tongue

10

contact element

12

connecting element

14

side panel

16

spring element

18

carriage

20

side surface

22

clearing element

24

hinge element

26

wall

28

First contact legs

30

Second contact leg

32

interface

34

interface

36

interface

38

interface

40

gap

42

Claims (14)

1. A surge protection element, having
   a contact stud (10)
   and a contact element (12) spaced apart from the contact stud (10),
   wherein a connecting element (14) is provided, which can be transferred into a first position and a second position,
   wherein in the first position the connecting element (14) rests against the contact stud (10) and the contact element (12) in order to electrically connect the contact stud (10) to the contact element (12), and
   in the second position the connecting element (14) is arranged spaced apart from the contact stud (10) and the contact element (12),
   wherein in the first position a thermally separable connection is provided between the connecting element (14) and the contact stud (10) and between the connecting element (14) and the contact element (12),
   wherein in the first position the connecting element (14) at least partially surrounds the contact stud (10) and/or the contact element (12).
2. The surge protection element according to Claim 1,
   characterized in that
   a spatial element (24) is provided, wherein the spatial element (24) is arranged such that it can move between the contact stud (10) and the contact element (12) that is spaced apart from the contact stud (10).
3. The surge protection element according to Claim 2,
   characterized in that
   the spatial element (24) is arranged on the connecting element (14).
4. The surge protection element according to Claim 2,
   characterized in that
   the spatial element (24) is moveable independently of the connecting element (14).
5. The spatial element according to any one of Claims 2 to 4,
   characterized in that
   the spatial element (24) is formed from a nonconductive material.
6. The spatial element according to any one of Claims 2 to 4,
   characterized in that
   in particular in the second position of the connecting element (14), the spatial element (24) remains in a gap (42) between the contact stud (10) and the contact element (12).
7. The surge protection element according to Claim 1,
   characterized in that
   the connecting element (14) is of a trough-shaped design.
8. The spatial element according to any one of Claims 1 to 7,
   characterized in that
   the thermally separable connection is formed from a material which can be transferred into a viscous state on reaching a melting temperature.
9. The spatial element according to any one of Claims 1 to 8,
   characterized in that
   the contact element (12) comprises a first contact member (30) and a second contact member (32) parallel thereto.
10. The surge protection element according to Claim 9,
    characterized in that
    the contact stud (10) is arranged between the first contact member (30) and the second contact member (32) of the contact element (12).
11. The spatial element according to any one of Claims 9 to 10,
    characterized in that
    in the first position the connecting element (14) is arranged between the first contact member (30) and the second contact member (32) of the contact element (12).
12. The spatial element according to any one of Claims 9 to 11,
    characterized in that
    the connecting element (14) surrounds the contact stud (10) in a U-shaped manner.
13. The spatial element according to any one of Claims 9 to 12,
    characterized in that
    in the first position the connecting element (14) forms at least one contact surface (34) with the first contact member (30) and at least one contact surface (40) with the second contact member (32) and at least one contact surface (36) and one second contact surface (38) with the contact stud (10).
14. The surge protection element according to Claim 13,
    characterized in that
    a thermally separable connection is arranged on the at least four contact surfaces (34), (36), (38) and (40).

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