DE102011113955A1 - Electrical switch mounted in e.g. motor car, has crank rod that is connected at ends of electric contacts respectively according to actuation of actuator unit such that both electric contacts are electrically interconnected with each other - Google Patents

Abstract

The switch (10) has electric contacts (11,13) that are provided with apertures (12,14) such that electric contact (13) is spaced apart from electric contact (11). A crank rod (15) is connected at ends of electric contacts respectively according to actuation of actuator unit (16) such that both electric contacts are electrically interconnected with each other.

Description

The invention relates to an electrical switch, in particular an electrical switch according to the preamble of claim 1.

This switch can be used, for example, in a motor vehicle with electric drive, in particular in an electric vehicle or hybrid vehicle, as a safety switch to discharge when needed, for example in an accident, the electrical energy source by short circuit. Batteries, fuel cells, generators and capacitors and combinations thereof are usually used as the source of electrical energy. In order to provide the power, the voltage and the current that are required for the electric drive, for example, several fuel cells are connected together to form a fuel cell stack. Such a fuel cell stack can provide for example with 250 fuel cells an operating voltage of 167 V and an operating current of 540 A and, for example, with 286 fuel cells of an operating voltage of 191 V and an operating current of 470 A. The discharge current at short circuit is very high at the beginning, for example, 2 kA to 10 kA, and decreases after a short time to a much lower, but still high value, for example, after 200 ms to about 600 A. The switch must therefore a very high Withstand switching current and then ensure a low-resistance connection permanently.

The publication DE 197 12 387 B4 forms the basis for the preamble of claim 1 and discloses a pyrotechnic switching element that takes over the function of a changeover switch and three current conductor sections, designed as a cylinder pin bridging element of electrically conductive material, a pyrotechnic charge and formed as a bolt shock element of electrically non-conductive material , The pyrotechnic charge closes the opening of a blind hole in a housing made of an electrically non-conductive material and generates when ignited in the blind hole a pressurized gas that drives the seated in the blind hole shock element deeper into the blind hole.

The next adjacent to the charge first conductor section has a lying in the housing first end, which is provided with a first through hole, which is aligned with the blind hole and equal in diameter to the blind hole. Between the first end and the charge is the shock element. The second conductor portion is disposed adjacent the first conductor portion and has a second end immersed in the housing and a second through-bore therein that is aligned with the first through-hole and thus with the blind bore. The third conductor section is arranged on the side of the second conductor section facing away from the first conductor section and has a third end located in the housing with a third through-bore which is aligned with the first and the second through-hole and equal in diameter to the blind hole.

The bridging member is located between the first and second conductor portions, is immersed in the first and second through holes. It thus ensures the electrical connection of the first conductor section with the second conductor section.

Upon ignition of the pyrotechnic charge, a force is exerted on the shock element by the pressure of the resulting combustion gases. As a result, the pushing member moves the lock-up member out of the first through-hole and through the second through-hole until the end of the lock-up member previously in the second through-hole is immersed in the third through-hole. In this situation after ignition of the charge, the second current conductor section is now electrically connected via the bridging element to the third current conductor section. The shock element is located after ignition between the first and the second conductor section, but without being immersed in the second through-hole. In this second through hole is rather that end face of the bridging element, which was immersed before ignition in the first through hole.

This known switching element is constructed very expensive and poorly suited as a short-circuit switch, since the bridging element is electrically connected to the second conductor section prior to ignition. As a result, for example, by corrosion, over time, an unintentional fixed connection of the bridging element with the second conductor section, which delays or even prevents the movement of the bridging element upon ignition.

The output of the invention is to provide an electrical switch according to the preamble of claim 1, which is constructed structurally simpler and better suited as a short-circuit switch.

This object is achieved by an electrical switch according to claim 1. Further embodiments are described in the subclaims.

• – einen ersten elektrischen Kontakt, der eine erste Öffnung aufweist;
• – einen zweiten elektrischen Kontakt, der eine zweite Öffnung aufweist und mit Abstand zu dem ersten Kontakt angeordnet ist;
• – einen Schaltbolzen, der eine Ausgangsposition, in der er mit dem zweiten Kontakt nicht elektrisch leitend verbunden ist, und eine Endposition einnehmen kann, in der er in beiden Öffnungen sitzt und beide Kontakte elektrisch miteinander verbindet;
• – eine ansteuerbare Betätigungseinheit für den Schaltbolzen; wobei
• – der Schaltbolzen vor Ansteuern der Betätigungseinheit die Ausgangsposition und nach Ansteuern der Betätigungseinheit die Endposition einnimmt; wobei
• – der Schaltbolzen in der Ausgangsposition mit dem ersten Kontakt nicht elektrisch leitend verbunden ist.

The invention proposes an electrical switch comprising

• A first electrical contact having a first opening;
• A second electrical contact having a second opening and spaced from the first contact;
• - A switching pin, which can assume a starting position in which it is not electrically conductively connected to the second contact, and an end position in which it sits in both openings and electrically connects both contacts with each other;
• - A controllable actuator unit for the shift pin; in which
• - The switching pin before driving the actuator unit assumes the starting position and after driving the actuator unit, the end position; in which
• - The switching pin is not electrically connected in the initial position with the first contact.

Since the proposed switch can only comprise two contacts, the design effort is very low. In addition, the proposed switch is particularly well suited as a short-circuit switch, for example, for the electrical energy sources in an electric or hybrid vehicle, since the switching pin is not electrically connected in the starting position with both the second and with the first contact. As a result, the emergence of an unintentional fixed connection of the switching pin with the first or second contact, for example by corrosion, is avoided.

The switching pin may be formed as desired in any manner and, for example, an electrically conductive material, such as copper, which surrounds a core of an electrically non-conductive material, such as plastic, and thus forms an electrically conductive surface of the switching pin. Advantageously, the switching pin consists of an electrically conductive material, for example copper.

In a preferred embodiment it is provided that an inhibiting element is attached to the first contact and / or second contact, which makes it difficult to release the switching pin from the end position.

This inhibiting element causes a self-locking of the proposed switch in the end position, since unintentional release of the switching pin is prevented by the first and / or the second contact.

Such self-locking can also be achieved by thin-walled, conductive metal lamellae of a layered first and / or second contact.

In particular, in the case of a layered construction of the first and / or second contact, the bores of the individual layers may have a different diameter, so that at least the layer with the smallest diameter in the weft direction is pierced during a penetration and leads to an additional self-locking.

This retarder is preferably a ring or split ring secured to the first contact and projecting radially inwardly into the first opening.

• – der Schaltbolzen in der Ausgangsposition mit beiden Öffnungen fluchtet. In einer weiteren bevorzugten Ausführungsform ist vorgesehen, dass die beiden Öffnungen kreisrund sind;
• – der Durchmesser der ersten Öffnung größer als der Durchmesser der zweiten Öffnung ist;
• – der Schaltbolzen ein Kegel oder Kegelstumpf ist und sich in Richtung von der ersten Öffnung zur zweiten Öffnung verjüngt.

In another preferred embodiment it is provided that

• - The switching pin in the starting position is aligned with both openings. In a further preferred embodiment it is provided that the two openings are circular;
• - The diameter of the first opening is greater than the diameter of the second opening;
• - The shift pin is a cone or truncated cone and tapers in the direction from the first opening to the second opening.

As a result, a self-centering contact system can be realized. In addition, the shift pin can be well distributed in the two openings, whereby unintentional loosening is difficult.

In a preferred embodiment, it is provided that the actuating unit has an electrically ignitable propellant charge.

This propellant causes a reliable, fast and powerful closing of the switch.

• – der Schaltbolzen in seiner von der zweiten Öffnung abgewandten Stirnseite eine Sackbohrung aufweist;
• – die Treibladung vor Ansteuern der Betätigungseinheit in die Sackbohrung ragt.

It can be advantageously provided that

• - The switching pin has a blind bore in its facing away from the second opening end face;
• - The propellant charge before driving the actuator unit projects into the blind hole.

As a result, to a shock element, as in the case of the document DE 197 12 387 B4 known switching element is required, can be dispensed with, the design complexity of the proposed switch is further reduced.

It is preferably ensured by suitable measures that no unwanted electrically conductive connection between NV (low-voltage range) and HV (high-voltage range) is present.

Exemplary embodiments of the invention will be explained in more detail below with reference to the attached drawings. However, the individual features resulting therefrom are not limited to the individual embodiments, but can be combined with individual features described above and / or with individual features of other embodiments. The details of the drawings are to be interpreted as illustrative, but not restrictive. The reference signs contained in the claims are not intended to limit the scope of the invention in any way, but merely refer to the embodiments shown in the drawings. The drawings show in:

1 a sectional front view of an electrical switch in a first embodiment with a switching pin, which assumes a starting position;

2 the bottom view to 1 ;

3 the switch of 1 in which the shift pin assumes an end position;

4 an enlarged sectional front view of a detail of an electric switch in a second embodiment with a switching pin, which assumes a starting position; and

5 the switch of 4 , in which the shift pin assumes an end position.

In the 1 . 2 and 3 is an electrical switch 10 according to the invention in a first embodiment shown schematically. The desk 10 includes a first electrical contact 11 who has a first opening 12 has a second electrical contact 13 that has a second opening 14 and spaced from the first contact 11 is arranged, a shift pin 15 and a controllable actuator unit 16 for the shift pin 15 , The shift pin 15 can be a starting position in the 1 and 2 is shown, and occupy an end position in the 3 is shown. In the starting position he is with the first contact 11 and the second contact 13 not electrically connected, whereas he in the final position fixed or press-fit in both openings 12 . 14 sits and both contacts 11 . 13 connects electrically with each other. The operating unit 16 is formed such that the shift pin 15 before driving the operating unit 16 the home position and after driving the actuator unit 16 takes the final position.

In this first embodiment, the two openings 12 . 14 circular, is the diameter D1 of the first opening 12 larger than the diameter D2 of the second opening 14 , and is the shift pin 15 a truncated cone and tapers in the direction of the first opening 12 to the second opening 14 , so in the 1 and 3 from top to bottom. This frustoconical shift pin 15 has one in the 1 and 3 upper, from the second opening 14 opposite first end face 17 and one in the 1 and 3 lower, opposite second end face 18 on, both of which are circular. In this case, the truncated cone is dimensioned such that the diameter d1 of the first end face 17 larger than the diameter D1 of the first opening 12 and the diameter d2 of the second end face 18 smaller than the diameter D2 of the second opening 14 is.

In this first embodiment, the shift pin 15 in the first front 17 a blind hole 19 on, assigns the operating unit 16 an electrically ignitable propellant charge 20 on, and sticks out the propellant charge 20 before driving the operating unit 16 So if the shift pin 15 the starting position occupies the blind hole 19 ,

In an embodiment not shown, the electrical switch 10 an electrically insulating element, which is provided for an undesired electrically conductive connection of a spark between the shift pin 15 and propellant charge 20 to prevent. The blind hole 19 is disposed inside the electrically insulating member. Preferably, the electrically insulating element is designed as a plastic sleeve or Kunststoffhütchen.

In the 1 It is good to see that the shift pin 15 in the starting position with both openings 12 . 14 is aligned and arranged coaxially with these and with its other end through the first opening 12 sticks out without touching, leaving the second end face 18 between the two contacts 11 . 13 lies.

In the 3 It is good to see that the shift pin 15 in the end position through both openings 12 . 14 sticks out and the two contacts 11 . 13 at the edges of their respective openings 12 . 14 touched, leaving the first end face 17 still above the first contact 11 lies, but the second end face 18 now below the second contact 13 ,

By activating the actuating unit 16 What, for example, in an accident with the help of a vibration sensor can be triggered, the propellant charge 20 ignited electrically, so that the resulting combustion gases in the blind hole 19 expand and the shift pin 15 from the starting position of the 1 and 2 in the final position of 3 float.

In the 4 and 5 is an electrical switch 10 according to the invention in a second embodiment shown schematically. This second embodiment is similar to the first embodiment, so that only the differences will be described in more detail below.

In this second embodiment is an inhibiting element 21 at the first contact 11 attached, which is a release of the shift pin 15 made difficult from the final position. The inhibitor 21 Here is a metallic part ring, preferably made of spring steel, at the bottom of the first contact 11 , For example, by welding or stapling, and radially inwardly into the first opening 12 stands out how good in the 4 can be seen.

When the shift pin 15 after activation of the actuating unit 16 from the ignited propellant charge 20 continue down through the first opening 12 is driven, it first touches with its lateral surface, the radially inner end of the Hemmelements 21 and take it further down with it, so that the inhibitor 21 with its radially inner portion opposite its at the first contact 11 attached radially outer portion angled down or kinked. This will cause unintentional release of the shift pin from the first contact 11 effectively prevented.

LIST OF REFERENCE NUMBERS

10

electrical switch

11

first contact

12

first opening

13

second contact

14

second opening

15

switching pin

16

operating unit

17

first end face

18

second end face

19

blind hole

20

propellant

21

Inhibiting element (optional)

D1, D2

diameter

d1, d2

diameter

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19712387 B4 [0003, 0023]

Claims (7)

Electric switch ( 10 ), comprising - a first electrical contact ( 11 ), which has a first opening ( 12 ) having; A second electrical contact ( 13 ), which has a second opening ( 14 ) and spaced from the first contact ( 11 ) is arranged; - a switching pin ( 15 ), which has a starting position in which it contacts the second contact ( 13 ) is not electrically conductively connected, and can assume an end position in which it is in both openings ( 12 . 14 ) and both contacts ( 11 . 13 ) electrically interconnects; - a controllable actuator unit ( 16 ) for the shift pin ( 15 ); where - the switching pin ( 15 ) before activating the actuating unit ( 16 ) the starting position and after activation of the actuating unit ( 16 ) occupies the final position; characterized in that - the switching pin ( 15 ) in the starting position with the first contact ( 11 ) is not electrically connected. Switch ( 10 ) according to claim 1, wherein - an inhibiting element ( 21 ) at the first contact ( 11 ) and / or second contact ( 13 ), which is a release of the shift pin ( 15 ) from the final position. Switch ( 10 ) according to claim 2, wherein - the inhibiting element ( 21 ) is a ring or partial ring that is attached to the first contact ( 11 ) and radially inwardly into the first opening ( 12 protrudes. Switch ( 10 ) according to one of the preceding claims, wherein - the switching pin ( 15 ) in the starting position with both openings ( 12 . 14 ) flees. Switch ( 10 ) according to one of the preceding claims, wherein - the two openings ( 12 . 14 ) are circular; The diameter (D1) of the first opening ( 12 ) greater than the diameter (D2) of the second opening ( 14 ); - the switching pin ( 15 ) is a cone or truncated cone and extends in the direction of the first opening ( 12 ) to the second opening ( 14 ) rejuvenated. Switch ( 10 ) according to one of the preceding claims, wherein - the actuating unit ( 16 ) an electrically ignitable propellant charge ( 20 ) having. Switch ( 10 ) according to claim 6, wherein - the switching pin ( 15 ) in its from the second opening ( 14 ) facing away from the front side ( 17 ) a blind bore ( 19 ) having; - the propellant charge ( 20 ) before activating the actuating unit ( 16 ) in the blind bore ( 19 protrudes.

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