DE202018100802U1 - Bistable switch - Google Patents

Abstract

A bistable switch (100) for disconnecting a high voltage power supply for a vehicle, comprising - a first contact element (102) having a first contact portion (106) for connection to a first current conductor (108), - a second contact element (104) second contact section (112) for connecting to a second current conductor (114), wherein in a first rest position of the contact elements (102, 104) a second end section (116) of the second contact element (104) is connected to a first end section (110) of the first contact element (10). 102) is arranged overlapping, so that the first contact element (102) the second contact element (104) electrically conductively contacted, - an insulating means (120), the first end face (124) on the first contact element (102) is applied or arranged at a maximum distance thereto is and is adapted, in a translational movement, the electrical contact (118) between the first contact element (102) and the second Kontaktelem ent (104), and - an actuator (122) mechanically coupled to the isolation means (120) and configured to translate the isolation means (120) to separate the electrical contact (118).

Description

Technical area

The present invention relates to a bistable switch for disconnecting a high voltage power supply for a vehicle and a method for operating the bistable switch.

State of the art

In particular, electric and hybrid vehicles have battery systems with high system voltages and a high storage density in order to provide the required drive power can. In the case of accidents and other disturbances, these systems and the electrical systems that distribute the corresponding electrical energy can pose a risk to vehicle occupants as well as to extinguishing and rescue forces, since these are the source of high DC voltages and the risk of short circuits and thus fires or dangerous contact Voltage may be exposed by exposed live parts. Therefore, in such vehicles fuses, relays or so-called contactors are used to safely disconnect the battery systems from the electrical system in the event of an accident or other technical problem. Among other things, fuses and pyrotechnic switches are used. After a certain period of time, fuses disconnect the correspondingly protected electrical conductor in case of short-circuit currents above a limit value. The pyrotechnic switches mentioned can be separated from a central control unit, for example coupled with the triggering of the airbags, the thus protected electrical conductor.

For example, in the DE102013209835A1 a release means (pyrotechnic switch) for non-reversible interruption of the conductive connection between the battery modules in an accident event described. The release agent may be formed as a pyrotechnic separation devices. The separation elements can be triggered by a separate control unit, the battery control unit or the airbag control unit. The supply of the control unit can be provided via the car battery and additionally or alternatively, an energy storage in the control unit, for example, by suitable capacitors.

The German patent application DE 10 2015 224 658 The applicant describes an electromechanical circuit breaker with two pairs of contacts, wherein in each case a contact of the contact pairs is arranged spatially separated from each other on a contact bridge.

The illustrated solutions for separating the HV traction battery have the disadvantage that they are either not reversible or that, for example, switching under load should be avoided, since otherwise the life of the contactors is significantly reduced. This is due to the formation of arcs during the switching process. A deletion of the arc takes place, for example, by deletion magnets. The ability to segregate hard shorts is limited to typically less than 5 kA, and would be desirable up to 16 kA. Furthermore, conventional contactors are heavy because they need to move heavy contacts over a solenoid actuator against a spring for opening (normaly off). The entire kinematics is so complex and leads to large dimensions and high weight.

Description of the invention

An object of the invention is therefore to provide a reversible release agent for applications from 40 V or high-voltage applications, especially for vehicles, using the simplest possible design means, which solves the above challenges or at least reduces the existing problems.

The object is solved by the subject matters of the independent claims. Advantageous developments of the invention are specified in the dependent claims, the description and the accompanying figures.

A bistable switch according to the invention is suitable for disconnecting a (high-voltage) power supply for a vehicle. In this case, the bistable switch comprises two contact elements, an insulating means and an actuator. The two contact elements each have a contact portion for connecting to a respective current conductor. Thus, the bistable switch can be arranged within a conductor to separate it. Furthermore, the contact elements in each case on the side facing away from the contact portion or an opposite end portion, wherein the two contact elements are arranged such that the first end portion of the first contact element and the second end portion of the second contact element overlap and establish electrical contact in a first rest position because they contact electrically conductive. The insulating means is operatively connected to the actuator, so that a translational movement is executable. In the first rest position of the insulation means, the first end face abuts against the first contact element or is arranged at a maximum distance therefrom. Upon actuation of the actuator and a resulting translational movement of the insulating means between the two contact means in the region of the electrical contact, ie in the overlapping region the end portions, the isolation means is arranged to separate the two contact means. As a result, the electrical line is interrupted and at the same time a plasma channel abgeschnürt or prevented an arc. The bistable design of the actuator and thus the bistable switch has advantages in the field of functional safety, as well as a safe state "a" can be kept simple. By means of an appropriately selected insulation means, voltages of more than 40 V, in particular high-voltage voltages of more than 60 V, in particular more than 400 V, in particular advantageously more than 900 V, can be switched even with high flowing currents, and possible arcs can be canceled or eliminated.

The idea of high-voltage applications is described below. The idea also solves the problem with 48V applications and erases reliably occurring arcs or prevents their formation. Thus, the application is not limited to high-voltage applications, but can also be used, for example, in 48 V applications.

On the actuator usually corresponding control terminals are provided, can be routed via the control signals to the actuator.

Preferably, the insulating means comprises a ceramic material. This provides a suitable electrical insulation. Furthermore, the first end side of the insulation means may have a wedge shape. Thus, the insulation means can be moved very easily between the two contact elements.

Further, a spring is optionally arranged on the first contact element, which is arranged to press or pull the first contact element in the direction of the second contact element.

Optionally, a lever couples the first contact element to the actuator. In other words, it is optionally provided that the first contact element and the actuator are mechanically coupled via a lever. When the insulating means is moved by the actuator in the first rest position to restore the electrical contact between the first contact element and the second contact element, the first contact element is actively moved to the rest position. Thus, advantageously, the contact can be actively secured or accelerated.

Advantageously, the actuator is bistable, with a first rest position and a second rest position. In the first rest position of the actuator, the electrical contact between the first contact element and the second contact element is made, in the second rest position this is interrupted by the insulating means. Especially in view of functional safety, this is an advantage.

In a preferred embodiment, the actuator comprises a coil and a magnetic core mechanically coupled to the insulation means. The coil is addressed via a control signal (coil voltage), whereby a translational movement of the magnetic core is caused. In this case, a direction of movement can be controlled by a corresponding polarity of the control signal.

In a particular embodiment, a propellant charge is optionally arranged on a side facing away from the insulating means of the actuator, which is adapted to move the insulating means between the two contact elements and thus to separate the electrical contact between them. The propellant may be a squib, as used in airbags. Although such a propellant charge is not reversible, the insulating means can be moved back into the first rest position via the actuator, even after a triggering of the propellant charge. Such a propellant can help to separate large currents in a short time. For example, the propellant could be coupled to a crash signal, such as a signal to deploy an airbag.

A method according to the invention for operating a bistable switch for disconnecting a high-voltage power supply for a vehicle comprises the steps of conducting, separating, holding and connecting. In this case, the bistable switch is set up to couple and / or to interrupt a first current conductor of the high-voltage power supply with a second current conductor of the high-voltage power supply.

In the step of conducting electrical energy is passed through a first contact element and a second contact element of the bistable switch. In this case, a first contact section of the first contact element is electrically coupled to a first current conductor of the high-voltage power supply and a second contact section of the second contact element is electrically coupled to a second current conductor of the high-voltage power supply. In the first rest position of the bistable switch, the first contact element and the second contact element are electrically coupled to one another via an electrical contact that is established in an overlapping region of the two contact elements. The overlapping regions of the contact elements are referred to as end sections.

A first control signal initiates the step of disconnecting. An isolation means is translationally moved via an actuator responsive to the control signal in a first direction, whereby the two Contact elements of the bistable switch are electrically disconnected. Since the insulating means is arranged between the two contact elements, any arc is deleted immediately. The insulating means is thereby moved from the first rest position, in which a first end face of the insulating means on the first contact element or is arranged at a maximum distance thereto, in an activated position in which the insulating means the electrical contact between the first contact element and the second Contact element separates.

In the step of holding the insulating means is held in the activated position, so that the two contact elements are separated. Since it is a bistable switch, the activated position can also be referred to as a second rest position.

In the step of connecting the two contact elements are electrically connected. So it is a transition from the step of holding to the step of guiding. In response to a second control signal, the actuator moves the isolation means back to the first rest position and thus the electrical contact between the two contact elements is restored.

Short description of the figures

Hereinafter, an advantageous embodiment of the invention will be explained with reference to the accompanying figures. Show it:

1 a schematic representation of a bistable switch according to an embodiment of the present invention;

2 a further schematic representation of a bistable switch according to the in 1 embodiment shown;

3 a schematic representation of a bistable switch according to another embodiment of the present invention; and

4 a flowchart of a method for operating a bistable switch according to an embodiment of the present invention.

The figures are merely schematic representations and serve only to illustrate the invention. Identical or equivalent elements are consistently provided with the same reference numerals.

1 shows a bistable switch 100 with a first contact element 102 and a second contact element 104 , At a first end relative to a longitudinal extension, the first contact element 102 a first contact section 106 on which is set up, with a first conductor 108 to be electrically connected. The connection between the first contact section 106 and the first conductor 108 , So the connection between the first contact element 102 and the first conductor 108 is via a flexible connection 109 produced. Under the flexible connection 109 can be a contact bridge 109 be understood that is electrically conductive, but mechanically flexible. This is in one embodiment, a wire mesh 109 , In another embodiment, the flexible connection 109 designed as a flex element. In 2 the necessary functionality is clarified that a high current carrying capacity of the flexible connection 109 must be given at the same time a mechanically movable connection to the first contact element 102 in relation to the second contact element 104 to arrange in the room movable. Based on the longitudinal extent on the first contact section 106 opposite side has the first contact element 102 a first end portion 110 on. At a first end relative to a longitudinal extent, the second contact element 104 a second contact section 112 on which is set up, with a second conductor 114 to be electrically connected. Based on the longitudinal extent on the second contact section 112 opposite side has the second contact element 104 a second end portion 116 on. The first end section 110 and the second end portion 116 are arranged overlapping and form an electrical contact in a first rest position 118 , Furthermore, the bistable switch 100 an isolation agent 120 as well as an actor 122 on. A front page 124 of the insulating agent 120 lies in the in 1 illustrated embodiment on the first contact element. In an alternative embodiment, not shown, the isolation means 120 at a maximum distance from the first contact element 102 arranged. The actor 122 is with the insulation 120 mechanically coupled and set up, the isolation means 120 from a first resting position - as in 1 shown - in a second rest position - as in 2 shown - translational move.

The present example shows an exemplary embodiment with a high-voltage application of, for example, 480 V or more than 900 V. However, the application example can also be used efficiently in 48 V applications.

In a preferred embodiment, the isolation means 120 , also as insulator 120 designated made of a ceramic material. As in 3 executed, it can be the front side 124 have a wedge shape, so that a separation of the electrical contact 118 is mechanically easier to reach.

The actor 122 is via a control line 126 with a control device 128 connected. The control device 128 is set up, a first control signal 130 and a second control signal 132 provide. This can happen, for example, with the control signals 130 . 132 to act on voltage signals having, for example, a different polarity, once in response to the first control signal 130 the isolation agent 120 move from the first rest position to the second rest position and another time in response to the second control signal 132 the isolation agent 120 to move from the second rest position to the first rest position. So can the control signals 130 . 132 also as a control signal 130 . 132 be designated.

At the in 1 illustrated embodiment, the actuator includes 122 a coil 134 and one with the insulating agent 120 mechanically coupled magnetic core 136 , The sink 134 is set up, a drive signal 130 . 132 to receive and responsive to the drive signal 130 . 132 to move the magnetic core and thus to move the insulation means. Not shown stops may be provided to stop the movement upon reaching one of the rest positions. Furthermore, at least one locking device may be provided to the insulating means 120 to keep in the respective resting positions.

2 shows that in 1 illustrated embodiment of a bistable switch 100 with the difference that the isolation agent 120 is arranged in the second rest position and thus no electrical contact between the first contact element 102 and the second contact element 104 is made. For the sake of clarity, a complete representation of all reference symbols is dispensed with, if this can be seen from the preceding figure. The first contact element 102 is about the flexible connection 109 electrically with the first conductor 108 coupled. In this case, the first contact element 102 around a pivot 238 movable.

Instead of turning around the pivot 238 would also be a mechanically flexible design of the first contact element 102 conceivable that this is made of a resilient material, through the insulation 120 in the illustration upwards, ie away from the second contact element 104 press, and if the isolation means 120 back to the starting position accordingly 1 goes, spring back to the starting position. However, this is a secondary favored solution in many applications in terms of current carrying capacity.

3 shows a further embodiment of a bistable switch 100 , In addition to the in 1 or 2 Components described is a spring 340 , a lever 342 as well as a full bridge 344 as part of the trigger electronics 128 intended.

The at the first contact element 102 arranged spring 340 is set up, the first contact element 102 in the direction of the second contact element 106 to press. In an alternative, not shown variant is the spring 340 instead of a compression spring (as shown here) designed as a tension spring and on the opposite side, ie on the side on which also the second contact element 104 is arranged.

The lever 342 is with the first contact element 102 as well as with the actor 122 mechanically coupled. The lever 342 is set up, the first contact element 102 to move to the first rest position when the actor 122 the isolation agent 120 moved to its original position.

This in 3 illustrated embodiment has an actuator 122 on top of that the isolation means 120 - also as an insulator 120 or ceramic wedge 120 designated - acts. This represents a decisive difference and advantage compared to pyrotechnic fuses, in which an actuator acts on a contact bridge and thus leads to an irreversible tripping. The isolation agent 120 opens the electrical contact 118 between the first contact element 102 and the second contact element 104 and at the same time extinguishes an arc which occurs when the contact elements are disconnected 102 . 104 occurs. Because the isolation agent 120 is electrically insulating and between the contact elements 102 . 104 is arranged after the operation.

Thus, a significantly increased capillary arc extinction capability is advantageously achieved while having a lower weight compared to conventional pyrotechnic fuses. The bistable design is additionally advantageous in terms of functional safety (FUSI). If the drive voltage (12V) breaks down due to a short circuit in the 12 V electrical system, the contactor remains 100 closed. For a hybrid construction is an electronics 344 Can be integrated for intelligent protection. The components of the bistable switch 100 are in a housing 348 arranged from the at least the end portions 110 . 116 stand out.

In other words shows 3 a bistable switch 100 with a top contact in the illustration 102 as the first contact element 102 , a lower contact in the illustration 104 as a second contact element 104 , a ceramic wedge 346 . 120 (Insulator 120 ) connected to an electromagnetic actuator 122 (actuator 122 ), a spring 340 to close the contact 118 (Pressure upper contact 102 at lower contact 104 ), a magnetic core 136 with coil 134 for two-way operation of the actuator 122 (just out). The lever 342 leads to an increase in the contact force when the actuator is energized 122 , The full bridge 344 Commutes the power for in / out (control signal 130 . 132 ).

In 3 is the bistable switch 100 shown in a closed rest position. The contact force is due to the spring 340 applied. She can over the lever 342 when tightening the actuator 122 increase. To open the contact 118 becomes the actor 122 so energized that the ceramic wedge 346 between the contacts 102 . 104 is pushed and thus separates them. At the same time deletes the wedge 346 the (emerging) arc by dividing the volume between the two contacts 102 . 104 fills and stops the plasma. If the circuit is interrupted, the wedge remains 120 . 346 between the contacts 102 . 104 (bistable off). For switching through the actuator 122 so energized that he has the wedge 120 . 346 between the contacts 102 . 104 moves away and thus the contacts 102 . 104 due to the spring force (the spring 340 ) and levers 342 closes.

The lever 342 In a particular embodiment, has a freewheel or dog to provide a force to make the electrical contact 118 by means of the backward movement of the insulating means 120 to effect, wherein in a direction of movement opposite thereto, a main part of the disconnecting the electrical contact 118 necessary force directly from the insulation 120 on the first contact element 102 is exercised.

As already stated, it is the task of the isolation means 120 the two contact elements 102 . 104 mechanically and thus electrically separate from each other and at the same time to extinguish an emerging arc. Because of that the isolation means 120 is formed electrically non-conductive, a maximum arc beyond the front page 124 from the first contact element 102 to the second contact element 104 to build up. That's why it's the insulating agent 120 set up in such a way that it is this way over the front 124 extended so far that the arc leaves. Furthermore, the path can also be replaced by an additional on an upper side of the second contact element 104 arranged electrically insulating wedge 350 be designed so that an arc already shortly after the release of the electrical contact 118 is deleted. This is a wedge 350 , which also serves as an electrically non-conductive insulation element 350 can be referred to and even if the wedge shape is preferred may have a different shape, as described on a surface of the second contact element, on which also the electrical contact 118 located, arranged such that the insulating means 120 on a side facing away from the second contact element on the insulating element 350 is moved past or is past vorbeegewegbar. Preferably, an adjacent to the with the second contact element 102 connected side of the isolation element 350 another side of the insulation element 350 with the housing 348 connected.

Due to the additional insulation element 350 An arc can already occur with a shorter movement of the insulation 120 be effectively prevented compared to an insert without the additional insulation element 350 ,

In a specific embodiment, the isolation element 350 designed as a blowing magnet. This blowing element 350 "blows" the arc in the direction of the actuated insulation means 120 , Since the plasma channel is cooled when approached, the arc breaks down. With this combination of activated insulation 120 and blowing magnet 350 a particularly fast extinguishing of the arc can be achieved.

Of the 3 is still another embodiment of the flexible connection 109 refer to. Thus, a wire mesh via a respective connecting pin with the first contact element 102 as well as with the first conductor 108 connected.

This in 4 The illustrated method of operating a bistable switch to disconnect a high voltage power supply for a vehicle includes the four steps of conducting S1, disconnecting S2, holding S3, and connecting S4:
In step S1 of conduction, electrical energy is conducted via a first contact element, which is electrically coupled to the first conductor via a first contact section, and a second contact element, which is electrically coupled to the second conductor via a second contact section, wherein in one first rest position of the contact elements, a second end portion of the second contact element are arranged overlapping with a first end portion of the first contact element, so that the first contact element, the second contact element electrically conductively contacted.

In step S2 of separation, in response to a first control signal, the two contact elements are separated by a translational movement by means of an insulating means mechanically coupled to an actuator, wherein the insulation means from a rest position, in which a first end face of the insulating means is applied to the first contact element or in a maximum Spaced thereto is moved to an activated position in which the insulating means separates the electrical contact between the first contact element and the second contact element, so that the insulating means between the first contact element and the second contact element is arranged.

In step S3 of holding, the insulating means is kept in the activated position, in which the two contact elements are separated, and thus a current flow is prevented.

In step S4 of the connection, the two contact elements are connected in response to a second control signal, in which the actuator moves the isolation means back into the first rest position and thus the electrical contact between the two contact elements is restored.

LIST OF REFERENCE NUMBERS

100

bistable switch

102

first contact element

104

second contact element

106

first contact section

108

first conductor

109

flexible connection, contact bridge, wire mesh

110

first end section

112

second contact section

114

second conductor

116

second end section

118

electric contact

120

Isolation agent, insulator

122

actuator

124

front

126

control line

128

Control device, tripping electronics

130

first control signal, drive signal

132

second control signal, drive signal

134

Kitchen sink

136

magnetic core

238

axis of rotation

340

feather

342

lever

344

full bridge

346

ceramic wedge

348

casing

350

Wedge, isolation element, blowing magnet

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 102013209835 A1 [0003]
• DE 102015224658 [0004]

Claims (7)

Bistable switch ( 100 ) for disconnecting a high-voltage power supply for a vehicle with - a first contact element ( 102 ), with a first contact section ( 106 ) for connecting to a first conductor ( 108 ), - a second contact element ( 104 ), with a second contact section ( 112 ) for connecting to a second conductor ( 114 ), wherein in a first rest position of the contact elements ( 102 . 104 ) a second end portion ( 116 ) of the second contact element ( 104 ) with a first end section ( 110 ) of the first contact element ( 102 ) is arranged overlapping so that the first contact element ( 102 ) the second contact element ( 104 ) electrically conductively contacted, - an insulating agent ( 120 ) whose first end face ( 124 ) at the first contact element ( 102 ) or is arranged at a maximum distance therefrom and is adapted, in the case of a translational movement, to make the electrical contact ( 118 ) between the first contact element ( 102 ) and the second contact element ( 104 ), and - an actuator ( 122 ), which with the isolation agent ( 120 ) is mechanically coupled and set up, the isolation means ( 120 ) translationally to the electrical contact ( 118 ) to separate. Bistable switch ( 100 ) according to one of the preceding claims, in which the insulating means ( 120 ) comprises a ceramic material. Bistable switch ( 100 ) according to one of the preceding claims, in which the end face ( 124 ) of the insulating agent ( 120 ) has a wedge shape. Bistable switch ( 100 ) according to one of the preceding claims, with one on the first contact element ( 102 ) arranged spring ( 340 ), which is set up, the first contact element ( 102 ) in the direction of the second contact element ( 104 ) to push or pull. Bistable switch ( 100 ) according to one of the preceding claims, with a lever ( 342 ) connected both to the first contact element ( 102 ) as well as with the actuator ( 122 ) is mechanically coupled, wherein the lever ( 342 ), the first contact element ( 102 ) to move to the rest position when the actuator ( 122 ) the isolation agent ( 120 ) moved to its starting position. Bistable switch ( 100 ) according to one of the preceding claims, in which the actuator ( 122 ) is formed bistable, with a first rest position and a second rest position. Bistable switch ( 100 ) according to one of the preceding claims, in which the actuator ( 122 ) a coil ( 134 ) and one with the insulating agent ( 120 ) mechanically coupled magnetic core ( 136 ).

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