DE202015106793U1 - fuse - Google Patents

Abstract

Protective device (1), preferably for safely disconnecting an electrical connection assembly (12) in a high current and / or high voltage application, comprising: a. a fuse (10) having a fusible conductor (11) between a first terminal (13) and a second terminal (14); b. a releasable (mechanical) separator (20) arranged and adapted to disconnect the electrical connection assembly (12) via the separator (20) between the terminals (13, 14) in response to a trip signal from the fuse (10).

Description

The invention relates to a protective device and a protective circuit with a fuse according to the features of claim 1.

The invention relates in particular to a protective circuit for an electrical supply network of a motor vehicle and an electrical supply network for a motor vehicle or the protection of a current path, preferably the protection of a busbar in a Krfatfahrzeug.

Motor vehicles today have a complex electrical network in terms of power supply and control. The electrical components are typically connected via a wired power supply or for transmission of high currents to line assemblies and / or bus bars. Vehicles therefore have an increasing number of electrically operated components, which include both driving-related components, as well as more comfort-oriented components that must, however, be protected from an overcurrent.

For this purpose, so-called fuse types are used regularly. A fuse is an overcurrent protection device that intentionally interrupts the circuit by melting a fused conductor when the current exceeds a predetermined current value for a sufficient time.

Fuses typically consist of an insulating body which receives two electrical contacts connected by a fusible link. The melt conductor is heated by the current flowing through it and melts when the rated current of the fuse is exceeded for a certain period of time. This protection function is called "triggering the fuse". Triggered fuses are unusable and must be replaced.

Depending on which vehicle components are to be secured, these sometimes have considerably different requirements with regard to the electrical power that has to be made available to them in order to enable their safe operation. Thus, corresponding motor vehicles often have both low-current consumers and high-current consumers, which include, for example, electric motors.

In the case of a working on the basis of an internal combustion engine motor vehicle, such a high-current consumer, for example, an electric motor, so for example, be a starter motor of the internal combustion engine. In the case of an electric vehicle or a hybrid drive concept, such an electric motor may also be a drive motor. Other high-current applications in the vehicle must also be sufficiently secured.

On the one hand, it may be advisable not least with regard to the safety of the passengers of the motor vehicle or its cargo to maintain at least partially the aforementioned systems in case of an accident or a malfunction in terms of their ability to function. On the other hand, however, depending on the nature of the accident or the serious malfunction, a considerable risk potential for the passengers or the charge of the motor vehicle can also emanate from the electrical supply network itself. It may therefore be advisable to safely and reliably deactivate individual components in terms of their functionality after an accident or other serious malfunction.

Various protection principles are already known from the prior art. The publication DE 10 2008 064 393 A1 discloses an apparatus and method for securing an electrical line assembly that includes an electrical fuse and a controllable switching element.

From the DE 197 57 026 A1 An electrical fuse is known which comprises a fusible element and a switch connected in parallel to it in the form of a bimetallic switch.

Furthermore, pyrotechnic fuses are known, which must be controlled via an external control. In addition to the control effort, these systems are complex and expensive. Another disadvantage of the solutions mentioned in the prior art is that the tripping characteristic is sometimes not satisfactorily resolved, especially at high electrical powers.

Fuses are limited in terms of their tripping characteristics and not suitable for various high-voltage applications as the only means of protection. A combination with a high-current relay is complex and sometimes unsatisfactory in the tripping characteristic.

The aforementioned pyrotechnic fuses are not intrinsically safe due to the external control. At high currents and appropriately sized fuse elements and correspondingly high-sized propellant charges are required, which should be avoided.

The invention is therefore an object of the invention overcome above-mentioned disadvantages and an improved protection device and a Provide protection circuit, in which in particular a reliable shutdown is guaranteed and an optimum between design effort, vehicle safety and space can be achieved.

This object is achieved by the feature combination according to claim 1 and claim 10.

The basic idea of the present invention is to provide a structural and functional synergetic combination of a conventional, but preferably inert, fuse with a mechanical isolator, the mechanical isolator being characterized by a characteristic fuse size, more preferably melting the fuse to initiate or activate the fuse mechanical separating element is used.

In this way, on the one hand, an external control for triggering the separating element can be saved and on the other hand, the dimensioning of the separating element can be reduced with respect to the separation force or the necessary energy for separating the fusible conductor, since the separation process is activated only when the fusible conductor has started to melt or melt ,

• a. eine Schmelzsicherung mit einem Schmelzleiter zwischen einem ersten Anschluss und einem zweiten Anschluss;
• b. ein auslösbares vorzugsweise mechanisches Trennelement, das angeordnet und ausgebildet ist, um auf ein Auslösesignal der Schmelzsicherung hin die elektrische Verbindungsanordnung über das Trennelement zwischen den Anschlüssen zu trennen.

The invention therefore proposes a protective device, preferably for safely disconnecting an electrical connection arrangement in a high-current and / or high-voltage application, comprising:

• a. a fuse with a fuse element between a first terminal and a second terminal;
• b. a releasable, preferably mechanical separating element, which is arranged and designed to separate the electrical connection arrangement via the separating element between the terminals in response to a triggering signal of the fuse.

In a particularly preferred embodiment of the invention, the separation of the electrical connection arrangement takes place in the region of the fusible conductor, which is specifically predamaged or weakened, in particular after the fusing, so that a reliable separation of the circuit can be achieved with a comparatively low mechanical separation force.

It is also advantageous if the separating element is a mechanical separating element which is formed on the front side with a separating section and can be actuated from a non-activated position (rest position) into a position separating the melting conductor (separating position).

In a further advantageous embodiment of the invention it is provided that the separating element activatable by means of an activatable pyrotechnic ignition unit, such as a detonator, an explosive charge or a pyroelement, preferably in its separating position d. H. Disconnect position is actuated.

Likewise, it is advantageous if the pyrotechnic ignition unit has igniter connections, which are each electrically connected to one of the terminals (for receiving or for applying an ignition signal), d. H. for detecting an ignition signal ZS from the fuse.

In this way, a characteristic size of the fuse (eg the voltage or the voltage drop across the fusible conductor), which changes when the fuse is triggered, can be used as a triggering signal for the pyrotechnic ignition unit.

In a preferred embodiment of the invention, the ignition signal (ZS) for activating the pyrotechnic ignition unit is therefore generated or used as a voltage signal, preferably via the voltage drop U _S during the melting of the fuse.

The pyrotechnic ignition unit possessing a characteristic trigger voltage U _L in a preferred embodiment, and the activation of the pyrotechnic ignition unit takes place on exceeding the voltage drop U _S via the trigger voltage U _L of the pyrotechnic ignition unit. For this purpose, the voltage tap on the fuse is connected directly to the ignition contacts of the ignition unit, so that the voltage drop also without the aid of a control circuit is applied directly to the ignition unit, as soon as the resistance increases due to the melting of the fuse conductor.

It is also advantageous if the exceeding of the voltage drop U _S when a maximum current value I _{max is} exceeded by the fusible conductor is used directly as a triggering signal for activating the pyrotechnic ignition unit.

It is also advantageous if the fuse has a sluggish characteristic in the tripping behavior, so that tripping is given up to a defined peak current resistance.

In a preferred embodiment of the invention, the separating element is designed as a plastic cutting element which cuts through the melt conductor, preferably a plastic wedge, or has it.

Another aspect of the present invention relates to a vehicle electrical system having at least one electrical connection arrangement which is protected by a protective device as described above.

Other advantageous developments of the invention are characterized in the subclaims or are shown in more detail below together with the description of the preferred embodiment of the invention with reference to FIGS.

Show it:

1 a schematic view of an embodiment of the present invention in normal operation and

2 a schematic view of the embodiment according to 1 in tripping mode with overload.

In the following the invention will be described with reference to an embodiment with reference to FIGS 1 and 2 explained in more detail, wherein like reference numerals refer to the same functional and / or structural features.

In the 1 is a schematic view of an embodiment of the present invention shown in normal operation. Shown is a protective device 1 for safely disconnecting an electrical connection assembly 12 in a high current and / or high voltage application, such as a vehicle electrical system (which is not shown here in detail). The protection device 1 includes a fuse 10 with a fusible link 11 between a first connection 13 and a second port 14 a busbar.

Further, a mechanical separator 20 shown so above the fusible link 11 is arranged and adapted to a trigger signal of the fuse 10 towards the fusible link as in 2 indicated to be able to cut through the dividing element 20 with its frontal separating section 21 from the in 1 shown not activated position (rest position) in one as in the 2 shown separating position has been actuated.

The actuation of the separating element 20 takes place by means of an activatable pyrotechnic ignition unit 30 , in the present case a pyrotechnic detonator with an explosive charge 32 represents. The pyrotechnic ignition unit 30 has this fuze connections 31 . 32 , each with one of the connections 13 . 14 are electrically connected via control wires, for detecting an ignition signal ZS from the fuse 20 ,

In normal operation, a current I <I _max , ie a current smaller than a permissible maximum current, flows through the fusible conductor. Since the fusible link 11 low impedance, is the voltage drop between the terminals 13 . 14 almost at zero or the voltage drop U _{S is} low. As long as the voltage drop but below the ignition voltage U _{Z of} the ignition unit 30 the pyrotechnic detonator lies, remains the separator 20 in its non-activated rest position.

As soon as the normal operation is exited and a current I> I _max , ie a current above a permissible maximum current, flows through the fusible conductor, the fusible conductor becomes 11 high impedance. The voltage drop then rises to a value above the ignition voltage U _{Z of} the ignition unit 30 the pyrotechnical detonator and the separator 20 is actuated by the energy in its release position on the pyoteschnische propellant, which is then ignited.

It can also be provided that the propellant gases targeted by a release in the release position opening in the ignition unit 30 be directed. It can further be provided that the separating element 20 has a locking geometry or cooperates with such a, to the separating element 20 to lock or fix in its release position.

It can also be provided that upon actuation of the separating element 20 the drive wires to the terminals 13 . 14 to be disconnected.

The invention is not limited in its execution to the above-mentioned preferred embodiments. Rather, a number of variants is conceivable, which makes use of the illustrated solution even with fundamentally different types of use.

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 102008064393 A1 [0009]
• DE 19757026A1 [0010]

Claims (10)

Protection device ( 1 ), preferably for safely disconnecting an electrical connection arrangement ( 12 ) in a high current and / or high voltage application comprising: a. a fuse ( 10 ) with a fusible conductor ( 11 ) between a first port ( 13 ) and a second connection ( 14 ); b. a releasable (mechanical) separating element ( 20 ), which is arranged and adapted to a trigger signal of the fuse ( 10 ) the electrical connection arrangement ( 12 ) via the separating element ( 20 ) between the terminals ( 13 . 14 ) to separate. Protection device ( 1 ) according to claim 1, characterized in that the separating element ( 20 ) is a mechanical separating element, which with a separating section ( 21 ) is formed and from a non-activated position in one of the Schmelleiter ( 11 ) separating position can be actuated. Protection device ( 1 ) according to claim 1 or 2, characterized in that the separating element ( 20 ) by means of an activatable pyrotechnic ignition unit ( 30 ) Activatable as a detonator, an explosive charge or a pyroelement, preferably in its separating position is actuated. Protection device ( 1 ) according to claim 3, characterized in that the pyrotechnic ignition unit ( 30 ) via igniter connections ( 31 . 32 ), each with one of the connections ( 13 . 14 ) are electrically connected, for detecting an ignition signal (ZS) from the fuse ( 20 ). Protection device ( 1 ) according to claim 4, characterized in that the ignition signal (ZS) for activating the pyrotechnic ignition unit (ZS) 30 ) is generated as a voltage signal, preferably via the voltage drop U _S during melting of the fuse. Protection device ( 1 ) according to claim 5, characterized in that the pyrotechnic ignition unit ( 30 ) has a characteristic tripping voltage U _L and the activation of the pyrotechnic ignition unit ( 30 ) when exceeding the voltage drop U _S on the trigger voltage U _{L of} the pyrotechnic ignition unit ( 30 ). Protection device ( 1 ) according to one of the preceding claims, characterized in that the exceeding of the voltage drop U _S when exceeding a maximum current value I _max by the fusible conductor ( 11 ) directly as a trigger signal for activating the pyrotechnic ignition unit ( 30 ) is used. Protection device ( 1 ) according to one of the preceding claims, characterized in that the fuse ( 10 ) has a sluggish characteristic in the tripping behavior, so that tripping is given up to a defined peak current resistance. Protection device ( 1 ) according to one of the preceding claims, characterized in that the separating element ( 20 ) as a the fusible conductor ( 11 ) durchrennendes plastic cutting element, preferably a plastic wedge is formed or has this. On-board network with at least one electrical connection arrangement ( 12 ), which have a protective device ( 1 ) is secured according to one of claims 1 to 9.

Images