High-voltage vehicle network of a motor vehicle, quick-break switch and method of operating the high-voltage vehicle network

A high-voltage motor vehicle electric system contains a high-voltage battery and a consumer network which are interconnected by an electric cable, and a quick-break switch for disconnecting the high-voltage battery from the consumer network. The quick-break switch receives an airbag signal. The airbag signal is used for actuating the quick-break switch to sever the electric cable supplying power to the consumer network.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates both to a high-voltage vehicle network of a motor vehicle with a high-voltage battery, with a consumer network and a quick-break switch as well as to a quick-break switch.

Motor vehicles are increasingly driven by an electric motor. A distinction is drawn in this case between pure electric vehicles and hybrid vehicles. In hybrid vehicles, in addition to the electric motor, a combustion engine is also present, by which the electrical energy required for operation of the electric motor is generated. The electric motor is usually part of a consumer network that is operated at a comparatively high electrical voltage, e.g. 450 V. An electrical voltage is provided by a high-voltage battery, and is output by an electrical cable to a converter for operation of the electric motor. Usually the electrical cable contains a relay, by which the supply of current can be started or stopped. This relay is, for example, connected to an ignition lock or the like, so that when the motor vehicle is parked, the converter and the electric motor are without electrical power.

In the event of an accident it is necessary to disconnect the high-voltage battery from the consumer network comparatively quickly and safely. Otherwise, as a result of damage in the consumer network and/or the electrical connection, short-circuits may arise which in turn can contribute to the development of a fire. It is also possible for the high-voltage battery itself to be overloaded, and thus to explode. Equally it is possible that parts of the motor vehicle, following an accident, are electrically live, which makes the rescue of occupants located within the motor vehicle more difficult.

Due to the inertia of the relay, fast disconnection of this sort is not possible using the relay that is present. It can also happen that, as a result of excess current already having occurred, the relay contacts of the relay have fused together and thus, even if the relay is appropriately driven, cannot separate from one another and thus interrupt the flow of current.

The high-voltage vehicle network must also be monitored for an accident. This is achieved, for example, by monitoring the consumer network for a short-circuit. As soon as a short circuit of this sort is detected, the high-voltage battery is disconnected from the consumer network. The disadvantage here is that the short-circuit must already have occurred, and that a possible fire may already have started.

SUMMARY OF THE INVENTION

The invention is based on the object of permitting a particularly appropriate disconnection of a high-voltage battery from a consumer network which, in the event of an accident, triggers in particular comparatively quickly and reliably, and which advantageously is galvanic.

The high-voltage vehicle network of a motor vehicle contains a high-voltage battery and a consumer network which are interconnected by an electrical cable. The electrical voltage provided by the high-voltage battery is here preferably greater than 300 V, 350 V, and in particular greater than or equal to 375 V. Expediently the electrical voltage is greater than or equal to 400 V or 450 V. For example the electrical voltage is less than 500 V, 600 V or 700 V. The electrical cable contains at least two conductors, wherein each conductor is contacted electrically by one of the two poles of the high-voltage battery. The high-voltage vehicle network furthermore contains a quick-break switch, by which a disconnection of the high-voltage battery from the consumer network is possible. In particular, the quick-break switch contains a switch, which is included in one of the two conductors of the electrical cable, and which, when opened, interrupts the flow of current in the electrical cable.

The quick-break switch receives an airbag signal of the motor vehicle. In other words, the quick-break switch is triggered as soon as an airbag signal is present. For this purpose the quick-break switch is, in particular, directly coupled in signal terms to an airbag control device. Alternatively, the signal is made available over a bus system, such as CAN bus or FlexRay, in which case the quick-break switch and the airbag control device are preferably part of the bus system. Airbag signal here refers in particular to the signal whose occurrence ignites at least a propellant charge of an airbag present in the motor vehicle, thus causing an airbag to be inflated. The airbag signal is established on the basis of sensors that are already present in the motor vehicle. Due to the use of the airbag signal, therefore, no other components are necessary to detect that the motor vehicle is in an accident. The airbag signal is also one of the first signals in the motor vehicle to indicate an accident. Consequently the high-voltage battery is disconnected comparatively early from the consumer network, even before any possible short-circuits develop within the consumer network.

In the event that the airbag signal is generated incorrectly, and the high-voltage battery is therefore disconnected from the consumer network, then, as a result of the airbag being triggered, it is not possible for the motor vehicle to start operation again immediately. The motor vehicle must, rather, be repaired in a workshop. The high-voltage battery is reconnected to the consumer network in the course of such a repair. As a result of this, the motor vehicle is not out of operation for any additional time even when the quick-break switch has been incorrectly triggered, since it must always be repaired as a result of the triggered airbag.

In summary, the airbag signal refers in particular to the signal by which the airbag is caused to ignite. The airbag signal appropriately also refers to any signal of a sensor for monitoring the state of the motor vehicle that indicates a crash or an accident. In particular, the airbag signal corresponds to any crash signal of the motor vehicle. For example, such a crash signal is transmitted over a special cable or over the bus system, if one is present, to the quick-break switch.

In one suitable form of embodiment of the invention, the electrical cable that connects the high-voltage battery to the consumer network contains the quick-break switch. The quick-break switch contains a relay with relay contacts and with a magnetic drive, wherein, when the relay is operating, the relay contacts are moved relative to one another by the magnetic drive. The relay serves in particular for starting operation of the motor vehicle. In other words, a supply of current to the electric motor, if one is present, or to a converter is started by the relay and stopped when the motor vehicle is halted. The magnetic drive contains a control cable connected to a relay drive, wherein the relay drive is connected in particular to an ignition lock and/or a gas pedal of the motor vehicle.

The relay is expediently open when not electrically powered. Consequently in the event of an interruption of a flow of current by the control cable, a flow of current through the electrical cable from the high-voltage battery to the consumer network is interrupted. In this way, in the event of a technical fault of the motor vehicle, in particular of the control cable, the motor vehicle is placed in a safe state. A fault of this sort occurs, for example, during an accident.

The quick-break switch further contains an auxiliary drive with an activation cable that receives the airbag signal. In other words, the auxiliary drive is triggered as soon as the airbag signal is present. By use of the auxiliary drive, an opening of the relay contacts in the event of the presence of the airbag signal is accelerated. In other words, the relay contacts open more quickly when the auxiliary drive is activated than they would do if operated only by the magnetic drive. In particular, the auxiliary drive is non-reversible. For example, the auxiliary drive is operated by stored mechanical force, such as by a spring. Alternatively, the auxiliary drive is magnetic, wherein a magnetic field is generated by the auxiliary drive that is opposed to the magnetic field for closing the relay contacts that is generated by the magnetic drive. It follows that an opposing field is provided by the auxiliary drive in the activated state. It is particularly preferred for the auxiliary drive to be pyrotechnic, and expediently to comprise an explosive or propellant charge. A comparatively fast actuation of the auxiliary drive is enabled in this way.

The magnetic drive appropriately comprises a movable impact armature which is in particular in operative connection with the relay contacts. The position of the relay contacts with respect to one another is thus determined by the position of the impact armature, and a flow of current from the high-voltage battery to the consumer network is thus enabled or interrupted. In particular, the impact armature is shaped in the form of a cylinder and/or arranged inside an electric coil. The impact armature is here in particular implemented as a permanent magnet, so that the position of the impact armature is changed when current is made to flow through the electric coil.

Expediently the auxiliary drive acts on the impact armature. In other words, in the event of the auxiliary drive being actuated, the auxiliary drive is in operative connection with the impact armature. For example, in the event of the auxiliary drive being actuated, the impact armature moves at least partially out of the coil of the magnetic drive. In particular, the auxiliary drive is a further electric coil, which, in the event of the auxiliary drive being actuated, is subjected to a comparatively high current flowing through it, so that the impact armature is, even when the magnetic drive is activated, moved into such a position that the relay contacts are opened. Alternatively, or in combination with this, a mechanical spring, which is under tension when the auxiliary drive is not activated, acts on the impact armature when the auxiliary drive is activated.

It is particularly preferable for the impact armature to be conveyed by an explosive charge of the auxiliary drive out of the coil which may be present, or at least for its position to be changed such that the relay contacts are opened. The auxiliary drive is consequently of pyrotechnic design. Expediently the auxiliary drive contains for this purpose a punch that is arranged between the pyrotechnic charge and the impact armature. In particular, the guide of the punch is flush with the guide of the impact armature and expediently the punch is guided at least partially by the guide of the impact armature in the event of the auxiliary drive being triggered. Due to the use of the punch, a comparatively strong pyrotechnic propellant charge can be used. The punch here is configured for the comparatively high active pressures of the propellant charge. The impact armature, on the other hand, can be optimized for its magnetic properties, without having to be concerned about particular resistance to heat.

In particular, the auxiliary drive contains a separating element for severing the control cable. In other words, in the event that the auxiliary drive is activated, the control cable of the magnetic drive is severed, and the relay is thus without electrical power. For example, the control cable is cut by a cutting element, or is entirely destroyed in one region. Expediently, the relay is open when without electrical power, so that even in the event of a damaged relay drive, the relay is transferred by the separating element into an open state, and the consumer network is thus without electrical power. In particular, the separating element contains a punch that is mounted in a guide. In the event of an activation of the auxiliary drive, the punch is moved along the guide, whereby a pyrotechnic element, which preferably is positioned at one end of the punch in the direction of the guide, is preferably ignited when the auxiliary drive is activated. The punch has a hole that runs perpendicularly to the guide of the punch. The control cable, or at least an electrical conductor of the control cable of the magnetic drive, is arranged inside the hole. When the punch moves along the guide, the control cable is consequently stretched out until it breaks, and thus a flow of current through the control cable is interrupted.

Expediently the punch here also acts on the impact armature, if this is present. As a result of this, power is switched off from the magnetic drive and the impact armature, which is in operative connection with the relay contacts, is also moved. In summary, the quick-break switch particularly contains the magnetic drive and the impact armature, which is in operative connection with the relay contacts. The impact armature is arranged here inside an electric coil. The quick drive furthermore contains the punch with the hole, through which the control cable of the magnetic drive passes. The guide of the punch is here flush with the guide of the impact armature of the magnetic drive. As a consequence, if the auxiliary drive is triggered, the control cable of the relay is first severed, and then the impact armature is moved at least partially out of the electric coil by the punch, so that the relay contacts are opened. In this way, a comparatively fast opening of the relay contacts is enabled.

In an alternative form of embodiment of the invention, the auxiliary drive is in operative connection with an insulating bulkhead for mechanically disconnecting the relay contacts. In particular the insulating bulkhead is driven by the auxiliary drive between the two relay contacts. For example, the insulating bulkhead is here shaped in the manner of a wedge and consists of an electrically insulating material. In the un-triggered state of the auxiliary drive, the wedge is displaced perpendicularly in respect of the closing direction of the relay contacts, and advantageously already lies at the side of the relay contacts. If the auxiliary drive is activated, the wedge is moved between the relay contacts, and thus the relay contacts are mechanically disconnected from one another. In this way the development of an arc between the relay contacts is prevented, and electrical power is comparatively quickly switched off from the consumer network. An unwanted reactivation of the relay is also prevented, since the insulating bulkhead between the relay contacts prevents the relay from carrying current.

In a further form of embodiment of the invention, the electrical cable contains an over current protection, implemented for example as a circuit breaker or, particularly preferably, as a fusible link. The over current protection is configured such that it is triggered by a short-circuit current of the high-voltage battery. The electrical cable further contains a short-circuit bridge, connected in parallel to the consumer network. The over current protection is here arranged on the battery side of the short-circuit bridge. In particular the electrical cable contains two electrical conductors, each of which is connected to one of the two poles of the high-voltage battery. One of the electrical conductors here contains the overcurrent protection. The two electrical conductors are connected together by the short-circuit bridge, wherein the over current protection is integrated into the circuit formed in this way.

The short circuit bridge contains the quick-break switch. If an air bag signal occurs, the short-circuit bridge is switched into a conductive state, so that a comparatively low electrical resistance is present in the electric circuit formed by the short-circuit bridge and the high-voltage battery. As a result, the short-circuit current of the high-voltage battery flows through the short-circuit bridge and the over current protection, which triggers as a result. In this way a flow of current through the electrical cable is interrupted and, as a consequence, the consumer network is also without electrical power. In this way, when the short-circuit bridge is short-circuited, the electrical energy flowing through the consumer network is already reduced even before the over current protection is triggered, which reduces the occurrence of fires or damage to other components of the motor vehicle. As a result of the overcurrent protection, a galvanic disconnection is implemented between the high-voltage battery and the consumer network. Expediently, in normal operation of the high-voltage vehicle network, the short-circuit bridge is open. In other words, the short-circuit bridge does not carry current when the quick-break switch is not activated.

The quick-break switch advantageously contains a semiconductor switch for this purpose, and, in particular, appropriate electronics, with which the air bag signal is processed. Due to the semiconductor switch, a comparatively fast switching to a conductive state of the short-circuit bridge is enabled. In particular, the semiconductor switch is closed when an electrical voltage is not present. In this way, in the event of a failure of the electronics, it is ensured that the electrical supply to the consumer network is switched off. A TRIAC or a thyristor is preferably used as the semiconductor switch. Preferably the quick-break switch consists of the semiconductor switch and of whatever electronics may be necessary to drive the semiconductor switch, wherein the semiconductor switch is connected into the current path of the short-circuit bridge. Alternatively, the quick-break switch contains a relay which is, for example, operated magnetically or pyrotechnically. By use of the relay, a flow of current through the short-circuit bridge is enabled or interrupted.

In a further form of embodiment of the invention, the quick-break switch is part of the electrical cable that connects the high-voltage battery to a consumer network, and contains a relay and a semiconductor switch that are connected in series. The relay for example receives, in addition to the air bag signal, also control signals which are generated in particular by a gas pedal. When the airbag signal occurs, both the semiconductor and the relay are transferred into an open state. The semiconductor switch here exhibits a comparatively fast switching characteristic, so that electrical power is comparatively quickly removed from the consumer network. By means of opening the comparatively slow relay, in addition, a galvanic disconnection between the consumer network and the high-voltage battery is realized. Consequently the quick-break switch enables a disconnection of consumer network from the high-voltage battery that is both fast and secure.

The quick-break switch is preferably part of a motor vehicle, and contains a relay with a magnetic drive and an auxiliary drive. The auxiliary drive is, expediently, mechanical, magnetic or, particularly preferably, pyrotechnic, and contains an activation cable, via which a control signal for activating the auxiliary drive is output. The magnetic drive contains a control cable that is connected to a relay drive, wherein the supply of current to the magnetic drive is made by the relay drive. Expediently, the auxiliary drive contains a separating element, by which, when the auxiliary drive is activated, the control cable of the relay is severed. In this way, an activation of the magnetic drive is interrupted, in particular irreversibly. Alternatively, or in combination with this, the effect of the magnetic drive is reinforced by the auxiliary drive, in particular the drive in a single, particular direction. The auxiliary drive appropriately acts on an impact armature of the magnetic drive, if this is present.

Expediently the disconnecting element is a punch with a hole perpendicular to a guide of the punch, and the control cable of the relay is passed through the hole. In this way, a change in the position of the control cable with respect to the punch is prevented, and a severing of the control cable when the auxiliary drive is triggered is always ensured. Expediently, the punch acts on an impact armature, if present, of the magnetic drive, so that this is moved by means of the punch when the auxiliary drive is activated. In this way an activation of the magnetic drive is cancelled when the auxiliary drive is triggered, and the magnetic drive is transferred into a defined state.

The electrical connection between a high-voltage battery of a high-voltage vehicle network of a motor vehicle and a consumer network is interrupted as soon as an airbag signal occurs. In other words, the airbag signal is employed as the trigger condition for interrupting the electrical connection between the high-voltage battery and the consumer network. In this way, further sensors for monitoring the motor vehicle as to whether an accident is present are not necessary. The airbag signal is also of comparatively assured quality, so that false triggering is only comparatively rare. In particular, the airbag signal is detected first, and after detection, the electrical connection is interrupted in a further working step.

DETAILED DESCRIPTION OF THE INVENTION

Parts and magnitudes that correspond to one another are always given the same reference signs in the figures.

Referring now to the figures of the drawings in detail and first, particularly toFIG. 1thereof, there is shown a high-voltage vehicle network2of a motor vehicle. The high-voltage vehicle network2contains a high-voltage battery4and a consumer network6. An electrical DC voltage of 450 V is made available by the high-voltage battery4, and is fed over an electrical cable8with two electrical conductors8a,8binto the consumer network6. One of the electrical conductors8amakes electrical contact with the positive pole of the high-voltage battery4, and the remaining electrical conductor8bmakes electrical contact with the negative pole of the high-voltage battery4. The consumer network6contains a converter, not illustrated, by which the DC voltage is transformed. An electric motor, which drives the motor vehicle that contains the high-voltage vehicle network2, is driven by the transformed voltage.

The conductor8bwhich makes electrical contact with the negative pole of a high-voltage battery4contains a relay10which is actuated, in a manner not indicated more precisely, by means of an ignition (ignition lock) or a gas pedal of the motor vehicle. The electrical conductor8athat makes electrical contact with the positive pole contains an overcurrent protection12, which is implemented as a fusible link, and a quick-break switch14. The quick-break switch14contains a relay16with a magnetic drive18which acts on two relay contacts20. The magnetic drive18is controlled by a relay drive22that is connected to the magnetic drive18by a control cable24. Control signals26that are created by the ignition of the motor vehicle2, in particular by an ignition key or the like, are detected for this purpose by the relay drive22. If the control signals26are absent, the relay contacts20are open. In other words, the relay16is open when not electrically powered.

The quick-break switch14further contains an auxiliary drive28, which is mechanically coupled to the magnetic drive18by a coupling30. The auxiliary drive28contains an activation cable32that is connected to a controller34. The controller34is connected to a bus system, and monitors this for an airbag signal36. The auxiliary drive28is either an electric coil, a spring under tension, or a pyrotechnic explosive charge.

In normal operation of the motor vehicle, the relays10,16are controlled by the control signal26created by the gas pedal or the ignition lock of the motor vehicle. In the event of an accident to the motor vehicle, the airbag signal36is generated, as a result of which an airbag of the motor vehicle is ignited. In addition, the airbag signal36is detected by the controller34, and passed on via the activation cable32to the auxiliary drive28, which triggers as a result. The auxiliary drive28acts, by means of the coupling30, on the relay contacts20, causing them to open. As a result, the consumer network is galvanically disconnected from the high-voltage battery4, and damage to or ignition of components of the consumer network6is prevented.

FIG. 2illustrates a further embodiment of the high-voltage vehicle network2. In comparison to the variant of the high-voltage vehicle network2illustrated inFIG. 1, the relay10that is fitted into the conductor8bthat makes contact with the negative pole of the high-voltage battery4is replaced by the quick-break switch14. Thus in normal operation of the high-voltage vehicle network2, no differences result, since the relay16of the second quick-break switch14performs the functions of the replaced relay10. In the event of an accident to the motor vehicle, and to the presence of the airbag signal36, and to a triggering of the two auxiliary drives28that are present, however, the conductor8bthat is connected to the negative pole of the high-voltage battery4is also, in addition to the conductor8athat is connected to the positive pole of the high-voltage battery4, disconnected by the relay contacts20, and thus the high-voltage battery4is securely disconnected from the consumer network6even in the event of an unwanted bridging of the electrical conductor8athat is connected to the positive pole.

A form of embodiment of the quick-break switch14is shown in perspective inFIG. 3Aand in a perspective sectional view inFIG. 3B. The magnetic drive18contains an electric coil38, whose electric terminals end in the control cable24. An impact armature40made of a magnetic material with a preferred magnetic direction is positioned inside the coil38. At one free end, the essentially cylindrical impact armature40has a hole42, which is in operative connection through a linkage, not illustrated, with the relay contacts20. Depending on the position of the hole42with respect to the coil38, the relay contacts20are open or closed. A guide46of a punch48of the auxiliary drive28is flush with a guide44of the impact armature40. The punch48consists of a comparatively tough material such as steel. By means of the punch48, a movement of the impact armature40in the direction opposite to that of the hole42, is limited. A pyrotechnic propelling charge50is positioned inside a housing52which contains the guide46, on the side of the punch48that lies opposite to the impact armature40. The propellant charge50is thus fully enclosed by the housing52and the punch48, and the activation cable32of the auxiliary drive28ends inside the propellant charge50.

The punch48has a hole54which runs perpendicularly to the guide46of the punch48. One of the conductors of the control cable24of the magnetic drive18, which is tightly connected, in the region that surrounds the punch48, to the housing52of the auxiliary drive28, runs through the hole54. The punch48, in connection both with holding the conductor of the activation cable24, as well as with the relatively sharp-edged transitions, constitutes a disconnecting element56for severing the control cable24.

When the airbag signal36appears, a spark occurs between the ends of the activation cable32, which triggers the pyrotechnic propellant charge50. Due to the chamber-like design of the space within which the propellant charge50is located, the punch48is accelerated along the guide46in the direction of the impact armature40. As a result, by the punch48acting as a disconnecting element46, the control cable24is sheared in the region between the punch48and the housing52, and thereby severed, which occurs due to the movement of the region of the control cable24that is located inside the hole54in the direction of the impact armature40and of a stable position of the other region of the control cable24, in connection with the comparatively sharp edges of the punch48and of the housing52. As a result of this, a supply of current to the coil38is interrupted, and the impact armature40is moved by a spring, not illustrated here, in the direction of the hole42, and the relay contacts20are then opened. The spring is the component of the relay16which, when current is switched off from the relay16, transfers the relay contacts20into an open state. In addition, the impact armature40is accelerated by the punch48in the direction of the hole42when the airbag signal36occurs, which accelerates an opening movement of the relay contacts20, preventing any melting between these that could arise as a result of an overcurrent.

FIG. 4Aillustrates a further form of embodiment of the high-voltage vehicle network2with the consumer network6, the high-voltage battery4and the electrical cable8, which also contains the over current protection12. In comparison to the variant of the high-voltage vehicle network2shown inFIG. 1, the quick-break switch14with the relay16containing the relay contacts20is replaced by a further relay10. Consequently, the electrical cable8contains a relay10in each of the two conductors8a,8b, which receive the control signal26that is created by the gas pedal or the ignition lock of the motor vehicle. The electrical cable8further contains a short-circuit bridge58, by which the two conductors8a,8bof the electrical cable8make contact with one another, and which consequently is connected in parallel with the consumer network6. The two relays10are here arranged between the short-circuit bridge58and the consumer network6, whereas the overcurrent protection12is located on the battery side of the short-circuit bridge58. The short-circuit bridge58contains the quick-break switch14, which contains a semiconductor switch60in the form of a TRIAC and a controller62. The controller62receives the airbag signal36.

In normal operation of a high-voltage vehicle network2, the semiconductor switch60is open, and consequently the short-circuit bridge58is not conductive. When the airbag signal36occurs, the semiconductor switch60is changed into a conductive state by the controller62. Consequently, in this case, an electrical current is carried by the short-circuit bridge58. The electrical resistance of the short-circuit bridge58is here less than the electrical resistance of the consumer network6, so that the electrical energy made available by the battery4flows primarily only through the short-circuit bridge58, and not in the consumer network6. As a consequence of the short-circuit current flowing through the circuit comprised of the battery4, in each case a part of the two conductors8a,8b, the over current protection12and the short-circuit bridge58, the over current protection12is triggered, as a result of which a flow of current through the electrical cable8is prevented. As a result of this, the consumer network6is galvanically disconnected from the high-voltage battery4.

In comparison to the previously illustrated variant of the high-voltage vehicle network2, inFIG. 4Bthe semiconductor switch60is replaced by a relay64, and the controller62is modified for activation of the relay64instead of the semiconductor switch60. Otherwise, the mode of operation of the quick-break switch14and of the over current protection12in connection with the short-circuit bridge58and the airbag signal36is as described inFIG. 4A.

In a further form of embodiment of the high-voltage vehicle network2shown inFIG. 4Cthe quick-break switch14is replaced in comparison with the variant shown inFIG. 4B. The quick-break switch14again contains the controller62which receives the airbag signal36. By means of this, however, a drive68that acts on two switch contacts66is operated. The drive68is, for example, implemented pyrotechnically, so that when the airbag signal36occurs, an explosive charge is ignited and the two switching contacts66are brought into contact with one another, which results in a conductive state of the short-circuit bridge58.

A final form of embodiment of the high-voltage vehicle network2is illustrated inFIG. 5, which, with the exception of the quick-break switch14, corresponds to the form of embodiment illustrated inFIG. 1. The quick-break switch14shown here again contains the relay16with the magnetic drive18and the relay contacts20, which are in operative connection with the magnetic drive18. The quick-break switch14further contains a semiconductor switch70which is connected in series with the relay contacts20and the over current protection12, and is arranged between these two. The quick-break switch14further contains a controller72, which receives the control signals26and the airbag signal36. During normal operation of the high-voltage vehicle network2, the semiconductor switch70is always in a closed state, and consequently carries current. Due to the presence of control signals26, the magnetic drive18is supplied with current by the controller72, and the relay contacts20are consequently operated. When the airbag signal36occurs, the semiconductor switch70is switched by the controller72, and consequently a flow of current through it is interrupted. In addition, the magnetic drive18is actuated, and the relay contacts20are separated from one another. Due to the actuation of the semiconductor switch70, a comparatively fast interruption of a flow of current through the electrical cable8is enabled, whereas, as a result of the opening of the relay contacts20, which is slow in comparison, a galvanic disconnection of the consumer network6from the high-voltage battery4is achieved. As a result, by the semiconductor switch14, a comparatively fast current interruption followed by a galvanic disconnection is enabled.

The invention is not restricted to the exemplary embodiments described above. Rather, other variants of the invention can also be derived by the expert, without leaving the object of the invention. In particular, furthermore, all the individual features described in connection with the exemplary embodiments can also be combined with one another in other ways without leaving the object of the invention.