The invention relates to an arrangement for an electrical switch element, and more particularly, to an electrical switch element for switching high currents.
Known electrical switch elements include a contact switch chamber and two contacts which are arranged in the contact switch chamber. Switch elements which are constructed in this manner are, for example, used in electric and hybrid motor vehicles in order to switch the high currents which occur therein.
The two contacts are electrically connected to each other by means of a movable bridging element. When the connection is separated, due to the high currents and field strengths, an electric arc occurs between a contact and the bridging element. The electric arc can burn combustible plastics materials in the chamber into carbon black. This carbon black accumulates in the chamber and, owing to its electrical conductivity, can lead to short-circuits and creep currents between the two contacts.
An object of the invention, among others, is to provide an electrical switch element in which the risk of short-circuits and the occurrence of creep currents between the contacts are reduced. The disclosed electrical contact switch chamber includes two contacts, a wall having a base and sides surrounding the two contacts; and at least one insulation slot having an opening extending transversely relative to a direction between the contacts. The at least one insulation slot is disposed along a portion of the wall between the two contacts.
The invention will now be described by way of example with reference to the accompanying figures, of which:
The invention is explained in greater detail with reference to embodiments of an electrical switch element. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and still fully convey the scope of the invention to those skilled in the art.
The contact switch chamber 2, as shown in
A base 4 and sides 5 of the contact switch chamber 2 each constitute a wall 27 surrounding the contacts 3. Between the two contacts 3 and along the wall 27, two insulation slots 6 have an opening 7 which extends transversely relative to a direction between the two contacts 3.
The contact switch chamber 2 is sub-divided into two part-chambers 8 by the partition wall 9, which extends away from the base 4 and protrudes into the contact switch chamber 2. The partition wall 9 does not extend as far from the base 4 as the sides 5. The part-chambers 8 each contain a contact 3, are connected to each other, and each have an insulation slot 6.
The insulation slots 6 merge directly into the partition wall 9, that is to say, a wall of the insulation slot 6 also forms a part of the partition wall 9. The insulation slots 6 extend between the two contacts 3 along a direction of the walls 27; along the base 4 and the sides 5 and parallel to a direction between the contacts 3, and are continuous on the base 4, at the sides 5 and therebetween. The insulation slots 6 have in the region of the base 4 a substantially U-shaped cross-section.
The insulation slots 6 have in the sides 5 a different cross-section from that at the base 4. At the sides 5, the insulation slot 6 expands behind the opening 7. In this region there is therefore a hollow space which has a larger cross-section than in the region of the opening 7. The length of the inner wall is thereby increased, particularly in the regions which face away from the opening 7. In the example embodiment shown, the insulation slot 6 extends at the side 5 parallel with an extraction direction E in which the contact switch chamber 2 is extracted from the mould after the injection-moulding operation. Production is thereby simple.
The normal directions N of the openings 7 of the insulation slot 6, shown in
As also shown in
Two collection troughs 18 are each arranged beside an insulation slot 6 and merge via a step 19 directly therein. The collection troughs 18 are each located between a contact 3 and an insulation slot 6. The insulation slots 6 are therefore located when viewed from the contact 3 behind the collection troughs 18 and are shaded by them. The collection troughs 18 each have a chamfer 20 located at a side closer to the contact 3. As shown in
There are arranged laterally beside the contacts 3 blow magnets 23, as shown in
The bridging element 10 is shown in
The operation of the electrical switch element 1 will now be described.
In order to produce an electrical connection between the two contacts 3, the bridging element 10 is moved in the contact direction K, shown in
There may be incorporated in the materials forming the contact switch chamber 2 materials hard gases which are converted into the gaseous state by the heat of the electric arc and thereby increase the pressure in the contact switch chamber 2. A spatial expansion of the electric arc is thereby limited.
The two insulation slots 6 and opening 7 prevent the carbon-containing carbon black from leading to an electrical connection between the two contacts 3. Owing to the narrow opening 7, the pressure wave which is produced when the electric arc separates cannot be introduced into deeper regions of the insulation slot 6. As the neck portion 28 becomes longer, a pressure wave in the hollow space located therebehind can be increasingly damped. Furthermore, the edges of the opening 7 shade the deeper regions so that no carbon black is accumulated in the deeper regions. In the deeper regions of the insulation slot 6, therefore, an electrical connection between the two contacts 3 which is produced by the carbon black is interrupted. Short-circuits and creep currents between the two contacts 3 are thereby prevented.
The partition wall 9 further increases the creep path between the two contacts 3, which further increases the insulation effect. The partition wall 9 is only of half-height in order not to limit movability of the bridging element 10. It also does not protrude from the sides 5 into the contact switch chamber 2, also in order not to limit movability of the bridging element. Furthermore, the carbon black accumulates increasingly on the base, whereby a partition wall 9 is particularly advantageous in this instance.
The insulation slots 6 achieve a peripheral insulation effect since the substantially U-shaped path of the insulation slots 6 separates the two contacts 3 from each other. In an upward direction, no insulation slot 6 is required since there is arranged in this region the bridging element 10 which shades the region located above it. The insulation effect of the insulation slot 6 is again improved due to the cross-section at the sides 5. A shading effect is also thereby improved.
The two collection troughs 18 serve to collect the carbon black in a selective manner and to keep it away in particular from the insulation slots 6. Due to the collection troughs 18, it is thereby possible for the electric arc always to have substantially the same spacing from the contact 3 when it separates.
The camfers 20 reduce the development of carbon black since a chamfer or a rounded portion is more difficult for the electric arc to burn to carbon black than a sharp corner or edge. Furthermore, the contraction 22 makes it more difficult for the electric arc to move from the contact plate 11 onto the base 14.
The blow magnets 23 produce a magnetic field which is applied in the region of the contacts 3 perpendicularly relative to the contact direction K in which the bridging element 10 is applied to the contacts, and extends perpendicularly relative to the connection line between the two contacts 3. The electric arc which occurs when the electrical connection is separated is moved in a selective manner by the magnetic field away from the contact piece 12 in an inward or an outward direction. In this instance, it increases and ultimately separates.
The magnetic field created by the blow magnets 23 forms a magnetic circuit which is directed through the contact switch chamber 2. Owing to the coupling via the flux-conducting metal sheets 24, 25, the magnetic field M within the contact switch chamber 2, in particular in the region of the contacts 3, is particularly strong and the extinguishing effect of the magnetic field M is particularly good.
|10 2013 210 195||May 2013||DE||national|
This application is a continuation of PCT International Application No. PCT/EP2014/061055, filed May 28, 2014, which claims priority to German Application No. 10 2013 210 195.3, filed May 31, 2013.
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|20160071670 A1||Mar 2016||US|