DE102015114894B4 - Two methods for targeted short-circuiting of a secondary battery and two electrical circuits with a secondary battery and a bridging unit - Google Patents

Abstract

Method for the targeted short-circuiting of a secondary battery (200), wherein the electrical connections of the secondary battery (200) are electrically bridged with a bridging unit (202), wherein the bridging unit (202) comprises a short-circuit switch (110, 214) which switches from a disconnected position to a Control position can be transferred, and wherein the bridging unit (202) has a load resistance RLast between the electrical connections of the secondary battery (200) which is below the internal resistance Rider secondary battery (200) when a short-circuit switch (110, 214) is in the control position, wherein the Short-circuit switch (110, 214) has an electrically conductive switching piston (1), an electrically conductive membrane (17, 19) or an electrically conductive contact plate (12, 30) as the switching element, the switching element at the transition from the disconnected to the control position of the Short circuit switch (110, 214) is subjected to a movement, and between ei contacts of the short-circuit switch (110, 214) connects to one another, whereby the electrical connections of the secondary battery (200) are bridged.

Description

The present invention relates to a method for the targeted short-circuiting of a secondary battery using a bridging unit for connecting the terminals or poles of the secondary battery. The invention also relates to an electrical circuit with a secondary battery and a bridging unit, the bridging unit being designed as a short-circuit / disconnector. The method according to the invention and the circuit according to the invention have the advantage that if the secondary battery is discharged via the bridging unit, no ignition of the secondary battery occurs.

In electric and hybrid vehicles, secondary batteries, in particular lithium batteries or lithium-ion batteries, are used as energy sources. A common problem with such secondary batteries is that if they are short-circuited, they have a tendency to overheat, which can ignite and cause the secondary battery to catch fire. The neighboring cells are inevitably ignited, which also results in a battery fire, which can lead to the cell exploding, possibly even with undesirable thrust development.

In order to prevent short circuits in secondary batteries, especially in vehicle accidents, so-called disconnectors are installed in the circuits, which interrupt the circuit in the event of an accident or as required and thus prevent a short circuit in the secondary battery. Since secondary batteries for electric and hybrid vehicles usually have battery terminal voltages between 600V and 1300V, such circuit breakers are not always reliable units for interrupting the circuit, since at such high voltages electric arcs can occur within the circuit breaker, which ultimately lead to the current from the battery cannot be safely interrupted in the event of a short circuit. In extreme cases, the disconnector can even be set on fire or explode.

Furthermore, in the event of an accident in a motor vehicle, for example, damaged areas in the wiring harness can occur which, in the event of multiple arcing in the wiring harness and between the wiring harness and the chassis or ground, can have any possible load resistance for the battery. If the load resistance that is applied to the electrical connections of a battery essentially corresponds to the internal resistance of the battery, it will develop its optimum performance, and it will also heat up to the maximum. The temperature inside the battery can rise to the ignition temperature of the battery materials - i.e. the housing materials and / or the electrolytes - which can ignite the battery and catch fire. Modern secondary batteries, such as lithium batteries or lithium-ion batteries, such as those installed in electric and hybrid vehicles, but also lithium polymer batteries, can be designed in such a way that they are intrinsically safe when the electrical connections of the battery are shorted. This can be achieved in that after a short circuit there is initially a high but only very short current peak and then a lower discharge current until the energy of the battery is exhausted. In conventional secondary batteries for electrically powered cars, the current peak is between about 10kA and 40kA and the discharge current is only in the range of about 1kA to 7kA. This discharge current, which is about an order of magnitude lower, can be maintained for a long time (for example several or many minutes), depending on the energy content of the battery, but the battery cells do not heat up until they ignite during the entire discharge time. A burn-up of the battery cells and thus a burn-up of the entire battery as well as an associated hazard to the environment is thus reliably avoided.

Since the reliability of disconnectors (safety switches) cannot always be guaranteed due to the possible formation of arcs, there is a great need for an additional fuse option that ensures that secondary batteries cannot ignite in the event of a short circuit in the wiring harness or in the current path fed by the battery .

The DE 10 2010 029 806 A1 relates to an electrical system for a vehicle, comprising an electrical power source and a switch, by means of which an electrical connection between the power source and the on-board network of the vehicle can be selectively established or interrupted, and a control device which is designed for one of one connected to the control device Sensor device detectable predetermined state to operate the switch to interrupt the electrical connection between the power source and the vehicle electrical system, characterized in that a short-circuit line is provided with a defined discharge resistor arranged therein for the controlled discharge of the power source, which is connected to the switch and the power source in this way that the power source can be selectively short-circuited by pressing the switch to disconnect the connection between the power queue and the vehicle electrical system.

The DE 10 2010 045 904 A1 relates to an energy storage device for supplying a drive of a motor vehicle with a first pole, a second pole, a fuse connected to the first Pole is connected, and a switch which is connected between the second pole and the fuse, characterized in that by means of the switch, the first pole can be short-circuited with the second pole via the fuse alone.

The DE 10 2011 089 817 A1 relates to a disconnection unit for disconnecting a battery from a network, wherein a fuse is also provided which serves to interrupt a circuit between the battery and the network, characterized in that the fuse is integrated in the disconnection unit. The DE 40 00 721 A1 relates to a medium-voltage switchgear with at least one cable connection panel and consumers connected to it, to which at least one switch panel with at least one earthing switch having a release is assigned, characterized in that the release is connected to fault sensors assigned to the consumers.

The US 2010/0 328 014 A1 relates to an electric circuit breaker device used in a vehicle having a circuit including an electric device and a storage battery for supplying power to the electrical device, the electric circuit breaker device being responsible for supplying the power from the storage battery to the electrical device in the event of a collision interrupts.

The DE 19 749 135 A1 relates to a device for the defined and rapid switching of electrical power circuits, characterized in that a piston plate driven by the exhaust gases or propellant gases of a pyrotechnic charge in the combustion chamber formed thereby pulls a contact tongue out of a contact spring or even tears the conductor in two parts, so that the current flow is reliably interrupted.

The DE 20 2014 003 287 U1 relates to a high-voltage electrical system of a motor vehicle, with a high-voltage battery and with a consumer network that are connected to one another by means of an electrical line, as well as with a quick disconnect switch for separating the high-voltage battery from the consumer network, the quick disconnect switch being acted upon by an airbag signal.

The DE 10 2012 208 470 A1 relates to a device for decoupling and / or bridging connections for a battery cell, the device having a first electrode connection, the first electrode connection being connectable to a first connection via the device, the device having the following features: a switching element, the switching element is designed to establish an electrical connection between the first electrode connection and the first connection in a primary switching state and to interrupt the electrical connection between the first electrode connection and the first connection in another switching state; and a destructible body, the destructible body having a non-linear characteristic curve, the characteristic curve representing a relationship between a physical variable and the strength of the destructible body, the destructible body being designed to close the switching element in the primary switching state in an intact state hold and in a destroyed state to switch the switching element to the other switching state.

The DE 10 2012 213 422 A1 relates to a battery management system for at least one battery cell, wherein the battery management system is designed such that it can provide a current path between poles of the at least one battery cell in response to a trigger signal, characterized in that the current path is designed so that a Arc in a fuse of the at least one battery cell is prevented or terminated after the fuse has been triggered.

The EP 2 851 972 A1 relates to a lithium-ion accumulator comprising a first electrode and a second electrode, which are separated from one another by means of an electrically insulating separating layer which can be penetrated by ions, characterized in that the first electrode is electrically connected to an electrode terminal that is connected to the second electrode by means of a terminal insulation is electrically insulated, with a reduction in the insulating effect of the separating layer also the insulating effect of the terminal insulation can be reduced or destroyed and thereby an electrical connection between the first electrode and the second electrode can be established via the electrode connection, so that the lithium-ion battery via this electrical connection is discharged.

It was therefore the object of the present invention to provide a method for targeted short-circuiting of a secondary battery and a circuit with a bridging unit, especially in the event of an undesired short circuit in the external current path fed by the secondary battery, for example in the event of an accident in an electric or hybrid vehicle , the secondary battery can be specifically short-circuited without heating it to an impermissibly high temperature, so that the associated risk of the secondary batteries igniting and burning is largely reduced or completely avoided.

The invention solves this problem by means of a method for the targeted short-circuiting of a secondary battery and an electrical circuit having the features of claims 1 or 7 and 10 or 12.

According to the inventive method for targeted short-circuiting of a secondary battery, the electrical connections of the secondary battery are electrically bridged with a bridging unit, the bridging unit having a load resistance R _load which is below the internal resistance R _{i of} the secondary battery. The load resistance R _{load of} the bridging unit preferably approaches 0, but is preferably in the range of 0 <R _load <R _i , the short-circuit switch having an electrically conductive switching piston, an electrically conductive membrane or an electrically conductive contact plate as the switching element, the switching element is subjected to a movement during the transition from the disconnected to the control position of the short-circuit switch, and thereby connects two contacts of the short-circuit switch to one another, whereby the electrical connections of the secondary battery are bridged.

If the load resistance R _{load is} less than the internal resistance R _{i of} the secondary battery, the secondary battery cannot deliver the maximum possible power and the heating of the battery cells is therefore limited. In this way, the risk of the secondary batteries igniting is greatly reduced, since operation with power adjustment, ie when R _load = R _i , is avoided.

The term “targeted short-circuiting” is understood to mean a deliberate short-circuit of the secondary battery, which is carried out by bridging the two connections of the secondary battery with the bridging unit. The targeted short-circuiting is preferably carried out when a short-circuit has already occurred in the external current path fed by the secondary battery.

A secondary battery is a rechargeable store for electrical energy on an electrochemical basis, which is also called an accumulator.

The external current path fed by the secondary battery is understood to be the current path that the battery feeds independently of the current path of the bridging unit.

The load resistance R _load is generally understood to mean the electrical resistance with which the secondary battery is loaded. The load resistance R _{load of} the bridging unit is understood to mean the resistance that the current path of the bridging unit has between the two terminals of the secondary battery. The bridging unit is defined in such a way that it begins at the first connection of the secondary battery and ends at the second connection of the secondary battery, in other words the bridging unit connects the two connections of the secondary battery and the load resistance R _{load of} the bridging unit is thus the entire resistance of this unit (without a further external load resistance) between the connections of the battery, ie in particular not just the resistance of an individual component of the bridging unit.

According to the invention, the internal resistance R _i is understood to be the design-related loss factor inside the battery. When the battery is loaded with an external electrical load, a voltage U _i drops across this and the terminal voltage of the battery decreases accordingly, although the source voltage Uo itself remains constant inside the battery.

The size of the internal resistance is not constant in real batteries, but depends on the load current, on the charge or discharge status of the battery, i.e. on the respective state of the chemistry of each individual battery cell, on the temperature of the individual battery cells, on the age of the battery cells, ie the general condition of the battery cell chemistry, the materials and electrolytes used as well as their purity and preparation, and the structure of the battery cells and their internal interconnection.

According to the invention, the load resistance R _{load of} the bridging unit is preferably at least 10%, most preferably at least 90%, below the internal resistance R _{i of} the secondary battery. In addition, the load resistance R _{load is} preferably greater than zero.

In a further embodiment of the method according to the invention, it is preferred that the total _{load resistance R total load} , which results from the load resistance of the bridging unit and the external load resistance R _L of the external current path fed by the secondary battery, is less than the internal resistance of the secondary battery. The current path fed by the secondary battery is defined in such a way that it begins at the first connection of the secondary battery and ends at the second connection of the secondary battery; in other words, the current path fed by the secondary battery connects the both terminals of the secondary battery. The load resistance of the bridging unit is again defined as described above.

In the case of secondary batteries for cars driven purely electrically or by means of a hybrid drive, the internal resistance R _i of suitable secondary batteries can be, for example, in the range of 3 mΩ. If the external load resistance R _L , i.e. the load resistance of all consumers connected to the battery (or the bridging unit) (including the line resistances), is also in this area in the event of accidents with damage to the wiring harness, i.e. in an area in which there is power adjustment, it occurs excessive heating and possibly ignition of the secondary battery. The load resistance R _{load of} the bridging unit is therefore selected according to the invention for a secondary battery with an internal resistance in the range of 3 mΩ, less than 3 mΩ, preferably less than 2 mΩ and most preferably in the range of greater than 0 mΩ and less than or equal to 2 mΩ. A correspondingly low load resistance is usually made possible by all materials with good electrical conductivity.

The short-circuit switch can be transferred from an isolated position to a control position. In the disconnected position, the electrical connections of the secondary battery have no electrical contact via the bridging unit. In the control position, however, the electrical connections of the secondary battery have an electrical contact via the bridging unit. In the method according to the invention, it is preferred that the short-circuit switch is transferred from a disconnected position to a control position in the event of the short-circuit mentioned above.

The short-circuit switch can also contain a sensor, for example a wire or glass fiber or PVDF sensor, which is preferably arranged so that the sensor is destroyed or crushed or cut when the short-circuit switch changes from the disconnected to the switch position, without this would interfere with the short-circuit process or the bridging of the connections of the secondary battery. Such a sensor offers the possibility of detecting whether the bridging has actually taken place.

The short-circuit switch preferably contains a first and a second contact, one of the contacts being connected to one of the terminals of the secondary battery.

In the case of the electrically conductive switching piston as a switching element, it is preferred that, in the disconnected position, the switching piston is connected to a first contact of the short-circuit switch and, when the switching piston moves along its axis, it encounters a second contact of the connecting switch and thus a connection between the first and the second contact of the short-circuit switch establishes. The switching piston can be made solid in its material, but it can also be hollow on the inside, so that its mass is significantly smaller and can thus be accelerated faster than without a hollow, with a short circuit being reached more quickly. The cavity in the piston can be filled with a lighter material, for example polyethylene or polyoxymethylene, or styrofoam, in order to keep the empty volume for the activatable drive as small as possible. This saves propellant powder and at the same time the switching piston can be accelerated faster and to higher speeds due to the higher combustion chamber pressure. This leads to a short circuit that is reached more quickly.

In the case of an electrically conductive membrane as the switching element, it is preferred that, in the disconnected position, the electrically conductive membrane is connected to a first contact of the short-circuit switch. To transfer the short-circuit switch into the switching position, the membrane is preferably moved or stretched in a direction in which there is a second contact of the short-circuit switch. Once the membrane has stretched or moved a certain amount, it is connected to the second contact of the short-circuit switch. This allows current to flow through the short circuit switch.

In the case of an electrically conductive contact plate as the switching element of the short-circuit switch, the contact plate itself is preferably not connected to either of the two contacts of the short-circuit switch in the disconnected position. To transfer the short-circuit switch to the control position, the contact plate is simultaneously moved onto the electrical contacts and connected to them. This allows current to flow between the two contacts.

If a contact plate is used as a switching element, the contact plate can, for example, have two contact pins, and the two contacts can be designed as multi-contacts (multi-contact sockets) so that in the switching position the contact pins of the contact plate are inserted into the contact-side multi-contacts. Conversely, the contact plate can also have multi-contacts, and the contacts themselves can be configured as contact pins, which are then introduced or retracted into the multi-contacts on the plate in the switching position.

In a further embodiment, it is preferred that, in the method according to the invention, the bridging unit or the external current path fed by the secondary battery has a circuit breaker as a fuse element in the event of a short circuit in the external current path. It is preferred here that the electrical connections of the secondary battery are electrically bridged with the bridging unit when the isolating switch does not switch off the current in the current path. The tripping of the short-circuit switch from the disconnected position to the control position can be carried out, for example, by a control unit. The control unit can be any conceivable control unit, for example it can be a control unit such as is used when airbags are triggered. The control unit preferably also triggers a transition of the disconnector from the master position to the disconnected position.

The short-circuit switch of the bridging unit can also be used to support a disconnector by short-circuiting the short-circuit path of the bridging unit and thus briefly allowing the discharge current of the battery to flow as far as possible via the short-circuit path. This allows the contacts of the circuit breaker to be opened without creating an arc. Shortly after the disconnector has been opened, the short circuit of the battery connections achieved by the bridging unit can then be completely or partially canceled again in order, for example, to protect the battery and not heat it up any further. It is also sufficient to close the short-circuit path at the same time or within a short time span of a maximum of approx. 1 to 1.5 ms after opening the disconnector, since an arc cannot develop in a stable manner in this short time span and would be extinguished again immediately.

By choosing a suitable piston or contact plate material with a higher specific electrical resistance, you can only accept so much current that the residual current is not drawn through the circuit breaker at the moment its contacts are opened, or the arc that is still formed is only weak forms and can be extinguished sufficiently well in the disconnector.

The movement of the switching element is preferably carried out by an activatable drive.

The activatable drive can be an inductive drive, an eddy current drive, a pin-puller drive or a gas pressure drive, whereby in the case of a gas pressure drive the gas pressure is generated by means of a gas-generating material, in particular by the combustion or oxidation of a liquid and / or solid gas-generating material, in particular an activatable pyrotechnic gas-generating material. Such actuators that can be activated have the advantage that bridging with the specified load resistance below the internal resistance can take place within a very short time, thus preventing the secondary battery from overheating or increasing heat.

In the case of an inductive drive, an induction coil can be provided for this purpose at a suitable distance from the switch housing. The switching element can be designed magnetically in a suitable manner. However, the switching element can also be equipped with an induction coil. It would also be conceivable to equip the switching element with an induction coil and to provide an electromagnetic reference point, for example a permanent magnet, at a suitable distance from the switching element. In this way, the switching element can therefore alternatively or additionally be moved inductively.

If the activatable drive is designed as an eddy current drive, it preferably has a power coil through which a surge current flows from the outside for the desired switching. For this purpose, the switching element is preferably made of a material with good electrical conductivity, whereby the surge current in the power coil induces a current which, according to Lenz's rule, is opposite to the excitation current in the power coil, whereby the switching element is repelled from the power coil extremely quickly and with high force and thereby tear off the sections of the connecting elements connected in the housing.

If the movement of the switching element is carried out by gas pressure, this is preferably transmitted to the switching element and moved in the process. Such a gas pressure can be generated pyrotechnically or built up through suitable gas lines. If the gas pressure is generated pyrotechnically, it is expedient to provide a combustion chamber located in the interior of the drive housing with propellant powder introduced, which can be activated by means of an igniter or igniter. In addition to propellant charge powders, however, liquid or gaseous fuels and oxidizers are also used as propellant charges, which can for example be injected into the combustion chamber, which is preferably integrated into the switch. Such fuels and oxidizers are referred to below as gas-generating materials. The pyrotechnic gas-generating materials, regardless of whether they react deflagrantly or detonatively, should also be included. After the activation of the combustion or oxidation process, these gas-generating materials generate a gas pressure (or in the case of already gaseous fuels and / or oxidizers, a gas pressure that is significantly higher than the initial state), which acts on the drive piston and the associated release element and moves the switch from the control position to Separated position moved. A spark plug, a glow wire or a Serve lighter. Alternatively or additionally, the combustion chamber could already contain either fuel or oxidizers (in liquid, solid or gaseous form). In order to provide a pyrotechnic generation of gas pressure and thus the pyrotechnic triggering of the switch, only a pyrotechnic mixture has to be inserted into a combustion chamber. At the desired point in time, this can then be ignited by an ignition or ignition means.

Alternatively or additionally, the combustion chamber can also be equipped with an igniter or igniter piece. With a suitably selected igniter or igniter, sufficient gas and / or exhaust gas products can be generated when it is ignited, so that sufficient pressure builds up in the combustion chamber. This can then move the switching element a sufficiently large piece via an end plate, which is also referred to as a release plate, which acts as a sabot, in order to be connected to the contact or the contacts of the short-circuit switch. If the pyrotechnic triggering of the switch is provided via a combustion chamber, the effect of the combustion chamber can be increased by introducing fillers into the combustion chamber. Such fillers can reduce the unneeded empty volume in the combustion chamber, so that an already much smaller amount of gas applies the pressure required to move the sabot and thus the switching element.

A pin-puller drive is understood to mean a drive that does not push the switching element into the control position of the connection switch, but rather by pulling it.

An electrical circuit according to the invention has a secondary battery and a bridging unit, which is connected to an external current path with an electrical consumer, the bridging unit having a current path for bridging the electrical connections of the secondary battery, in which a selectively triggerable short-circuit switch is provided can be transferred from a disconnected position to a control position, and wherein the current path of the bridging unit in the control position of the short-circuit _{switch has a load resistance R load} which is lower than the internal resistance R _{i of} the secondary battery, the short-circuit switch as a switching element having an electrically conductive switching piston, an electrically conductive one Has membrane or an electrically conductive contact plate, the switching element being subjected to a movement during the transition from the disconnected to the control position of the short-circuit switch, and two contacts of the short-circuit switch connects to each other, whereby the electrical connections of the secondary battery are bridged.

The electrical consumer can be any electrical or electronic device or unit that can be operated by the or another secondary battery.

The bridging unit can additionally have an isolating switch that can be transferred from a control position to an isolating position for disconnecting the external current path, the isolating switch and the short-circuit switch preferably being designed as a single structural unit in the form of a short-circuit / isolating switch, and the isolating switch and the short-circuit switch preferably are designed or controllable in such a way that the method according to one of claims 3 to 5 is carried out.

The bridging unit or the electrical circuit according to the invention can additionally comprise a control unit for moving the short-circuit switch from the disconnected position to the control position and / or for moving the disconnector from the control position to the disconnected position. The control unit can be any conceivable control unit, for example it can be a control unit such as is used when airbags are triggered.

1. (a) welcher aus einer ersten Stellung in eine zweite Stellung überführt werden kann,
2. (b) welcher ein Gehäuse, einen ersten Kontakt, einen zweiten Kontakt, einen dritten Kontakt, ein im Gehäuse bewegbares Ausrückelement und mindestens ein Verbindungselement aufweist, das in der ersten Stellung des Schalters eine elektrische Verbindung zwischen dem dritten Kontakt und dem zweiten Kontakt herstellt,
3. (c) wobei das Gehäuse einen das mindestens eine Verbindungselement umgebenden Innenraum aufweist,
4. (d) wobei das mindestens eine Verbindungselement an einem Ende an der Grundseite des Gehäuses und an dem anderen Ende an dem Ausrückelement im Inneren des Gehäuses befestigt ist, und
5. (e) welcher so ausgebildet ist, dass eine mechanische Bewegung des Ausrückelements den Schalter von der ersten Stellung in die zweite Stellung überführen kann, wobei das Ausrückelement mechanisch so auf das im Innenraum verlaufende mindestens eine Verbindungselement wirkt, dass die elektrische Verbindung zwischen dem dritten Kontakt und dem zweiten Kontakt an mindestens einer Trennstelle des Verbindungselements unterbrochen wird, und dabei eine Verbindung zwischen dem ersten und dem zweiten Kontakt entsteht, vorzugsweise dadurch, dass die Ausrückplatte elektrisch leitend ist und den ersten und den zweiten Kontakt verbindet.

The present invention also relates to a method for targeted short-circuiting of a secondary battery, the electrical connections of the secondary battery being electrically bridged with a bridging unit, the bridging unit comprising a short-circuit switch that can be transferred from a disconnected position to a control position, and the bridging unit in a The short-circuit switch located in the control position has a load resistance R _load between the electrical connections of the secondary battery, which is below the internal resistance R _{i of} the secondary battery, the bridging unit being designed as a short-circuit / disconnector

1. (a) which can be transferred from a first position to a second position,
2. (b) which has a housing, a first contact, a second contact, a third contact, a release element movable in the housing and at least one connecting element which, in the first position of the switch, establishes an electrical connection between the third contact and the second contact,
3. (c) wherein the housing has an interior space surrounding the at least one connecting element,
4. (d) wherein the at least one connecting element is fastened at one end to the base side of the housing and at the other end to the release element in the interior of the housing, and
5. (e) which is designed so that a mechanical movement of the release element can transfer the switch from the first position to the second position, the release element mechanically acting on the at least one connecting element running in the interior in such a way that the electrical connection between the third contact and the second contact is interrupted at at least one separation point of the connecting element, and a connection is created between the first and the second contact, preferably in that the release plate is electrically conductive and connects the first and second contacts.

• (a) welcher aus einer ersten Stellung in eine zweite Stellung überführt werden kann,
• (a) welcher ein Gehäuse, einen ersten Kontakt, einen zweiten Kontakt, einen dritten Kontakt, ein im Gehäuse bewegbares Ausrückelement und mindestens ein Verbindungselement aufweist, das in der ersten Stellung des Schalters eine elektrische Verbindung zwischen dem dritten Kontakt und dem zweiten Kontakt herstellt,
• (b) wobei das Gehäuse einen das mindestens eine Verbindungselement umgebenden Innenraum aufweist und
• (c) wobei das mindestens eine Verbindungselement an einem Ende an der Grundseite des Gehäuses und an dem anderen Ende an dem Ausrückelement im Inneren des Gehäuses befestigt ist, und
• (d) welcher so ausgebildet ist, dass eine mechanische Bewegung des Ausrückelements den Schalter von der ersten Stellung in die zweite Stellung überführen kann, wobei das Ausrückelement mechanisch so auf das im Innenraum verlaufende mindestens eine Verbindungselement wirkt, dass die elektrische Verbindung zwischen dem dritten Kontakt und dem zweiten Kontakt an mindestens einer Trennstelle des Verbindungselements unterbrochen wird, und dabei eine Verbindung zwischen dem ersten und dem zweiten Kontakt entsteht.

The present invention also relates to an electrical circuit with a secondary battery and a bridging unit, which is connected to an external current path which has an electrical load, the bridging unit having a current path for bridging the electrical connections of the secondary battery, in which a short-circuit switch that can be triggered in a targeted manner is provided which can be transferred from a disconnected position to a control position, and wherein the current path of the bridging unit in the control position of the short- _{circuit switch has a load resistance R load} that is lower than the internal resistance R _{i of} the secondary battery, the bridging unit being designed as a short-circuit / disconnector ,

• (a) which can be transferred from a first position to a second position,
• (a) which has a housing, a first contact, a second contact, a third contact, a release element movable in the housing and at least one connecting element which, in the first position of the switch, establishes an electrical connection between the third contact and the second contact,
• (b) wherein the housing has an interior space surrounding the at least one connecting element, and
• (c) wherein the at least one connecting element is fastened at one end to the base side of the housing and at the other end to the release element in the interior of the housing, and
• (d) which is designed so that a mechanical movement of the release element can transfer the switch from the first position to the second position, the release element mechanically acting on the at least one connecting element running in the interior in such a way that the electrical connection between the third contact and the second contact is interrupted at at least one separation point of the connecting element, and a connection is thereby created between the first and the second contact.

According to the invention, the short-circuit / disconnector switch can be designed such that it first short-circuits the battery connections in whole or in part by a mechanical movement of the release element and shortly thereafter begins to disconnect the external circuit.

Furthermore, the short-circuit / isolating switch can also be designed in such a way that, after the external circuit has been opened, the full or partial short-circuit path of the battery is completely or partially opened again.

The bridging unit with a short-circuit / isolating switch made in this way can have a certain electrical (non-zero) resistance in the short-circuit path that is small enough to allow the current flowing in the short-circuit path when the switch is closed to become so large that the current in the external circuit is so low that when the external circuit is opened, an arc formation is prevented or weakened sufficiently, and yet is so high that it can continue to bridge the battery connections without the battery cells being heated too much by the short-circuit current.

The short-circuit / isolating switch that can be used according to the invention can also have two or more connecting elements between the base side and the release plate, which connect the second and third contacts either electrically in parallel or electrically in series.

The short-circuit / isolating switch (switch) that can be used according to the invention is preferably used to interrupt a first current path fed by a secondary battery and to bridge the two connections of the secondary battery in a second current path. The first connection of the secondary battery is preferably connected to the first and the third contact of the switch and the second connection of the secondary battery is preferably connected to the second contact of the switch.

The switch according to the invention can also have a unit that can be activated, as described above.

• 1a: zeigt einen Kurzschlussschalter mit einem Schaltkolben als Schaltelement in der Trennstellung;
• 1b: zeigt den Kurzschlussschalter der 1a in der Leitstellung;
• 2a: zeigt einen Kurzschlussschalter mit einer elektrisch leitenden Membran in der Trennstellung;
• 2b: zeigt den Kurzschlussschalter der 2a in der Leitstellung;
• 3a: zeigt einen Kurzschlussschalter mit einer Kontaktplatte als Schaltelement in der Trennstellung;
• 3b: zeigt den Kurzschlussschalter der 3a in der Leitstellung;
• 4a: zeigt einen Kurzschlussschalter mit einer Kontaktplatte als Schaltelement mit einem Pin-Puller-Antrieb in der Trennstellung;
• 4b: zeigt den Kurzschlussschalter der 4a in der Leitstellung;
• 5a: zeigt einen Kurzschlussschalter mit einer Kontaktplatte als Schaltelement mit Kontaktstift in der Trennstellung;
• 5b: zeigt den Kurzschlussschalter der 5a in der Leitstellung.;
• 6a: zeigt einen Kurzschlussschalter mit einer Verbindungsplatte mit kontaktplattenseitigen Multikontakten in der Trennstellung;
• 6b: zeigt den Kurzschlussschalter der 6a in der Leitstellung;
• 7a: zeigt einen erfindungsgemäß verwendbaren Kurzschluss-/Trennschalter in einer ersten Stellung, der die gleichzeitige Unterbrechung eines ersten Strompfads mit der Verbindung eines zweiten Strompfads ermöglicht, wobei die Trennung des ersten Strompfads durch die Unterbrechung von zwei seriell verbundenen Verbindungselementen ermöglicht wird;
• 7b: zeigt den Schalter aus 7a in einer zweiten Stellung;
• 8a: zeigt einen erfindungsgemäß verwendbaren Kurzschluss-/Trennschalter in einer ersten Stellung, der die gleichzeitige Unterbrechung eines ersten Strompfads mit der Verbindung eines zweiten Strompfads ermöglicht, wobei die Trennung des ersten Strompfads durch die Unterbrechung von vier seriell verbundenen Verbindungselementen ermöglicht wird;
• 8b: zeigt den Schalter aus 8a in einer zweiten Stellung;
• 9a: zeigt einen erfindungsgemäß verwendbaren Kurzschluss-/Trennschalter in einer ersten Stellung, der die gleichzeitige Unterbrechung eines ersten Strompfads mit der Verbindung eines zweiten Strompfads ermöglicht, wobei die Trennung des ersten Strompfads durch die Unterbrechung von zwei parallel geschalteten Verbindungselementen ermöglicht wird;
• 9b: zeigt den Schalter aus 9a in einer zweiten Stellung; und
• 10 zeigt ein Prinzipschaltbild für eine Vorrichtung zum Vermeiden des Entzündens einer Sekundärbatterie mit einem erfindungsgemäß verwendbaren Kurzschluss-/Trennschalter.

Further features, but also advantages of the invention, emerge from the following drawings and the associated description. In the figures and in the associated descriptions, features of the invention are in Combination described. Some of the figures are slightly simplified and shown schematically.

• 1a : shows a short-circuit switch with a switching piston as a switching element in the disconnected position;
• 1b : shows the short-circuit switch of the 1a in the control center;
• 2a : shows a short-circuit switch with an electrically conductive membrane in the disconnected position;
• 2 B : shows the short-circuit switch of the 2a in the control center;
• 3a : shows a short-circuit switch with a contact plate as a switching element in the disconnected position;
• 3b : shows the short-circuit switch of the 3a in the control center;
• 4a : shows a short-circuit switch with a contact plate as a switching element with a pin-puller drive in the disconnected position;
• 4b : shows the short-circuit switch of the 4a in the control center;
• 5a : shows a short-circuit switch with a contact plate as a switching element with a contact pin in the disconnected position;
• 5b : shows the short-circuit switch of the 5a in the control center .;
• 6a : shows a short-circuit switch with a connection plate with multi-contacts on the contact plate side in the disconnected position;
• 6b : shows the short-circuit switch of the 6a in the control center;
• 7a : shows a short-circuit / disconnection switch that can be used according to the invention in a first position, which enables the simultaneous interruption of a first current path with the connection of a second current path, the separation of the first current path being made possible by the interruption of two serially connected connecting elements;
• 7b : shows the switch off 7a in a second position;
• 8a : shows a short-circuit / isolating switch which can be used according to the invention in a first position, which enables the simultaneous interruption of a first current path with the connection of a second current path, the separation of the first current path being made possible by the interruption of four serially connected connecting elements;
• 8b : shows the switch off 8a in a second position;
• 9a : shows a short-circuit / isolating switch which can be used according to the invention in a first position, which enables the simultaneous interruption of a first current path with the connection of a second current path, the separation of the first current path being made possible by the interruption of two connecting elements connected in parallel;
• 9b : shows the switch off 9a in a second position; and
• 10 shows a basic circuit diagram for a device for avoiding the ignition of a secondary battery with a short-circuit / disconnector that can be used according to the invention.

To make the invention easier to understand, the principle on which it is based is first used below 10 explained.

The block diagram in 10 shows a secondary battery 200 , a bridging unit at the battery terminals 202 each with a first input port 204 and a second input port 206 connected. A first and a second output port 208 , 210 the bridging unit 202 are connected to an external circuit, which is shown as the external load resistance R _L. Of course, the external load resistance R _{L can be formed} by any electrical consumer or also by any interconnection of several electrical consumers.

At the secondary battery 200 it can be, for example, a drive battery of an electrically operated vehicle, in particular a car. For this purpose, short-circuit-proof lithium batteries, for example lithium-ion batteries, are preferably used, which have an internal resistance in the range of a few milliohms.

The bridging unit 202 has in the illustrated embodiment both a circuit breaker connected in series _{with the external load resistor R L} 212 on, which is closed in the initial state shown, as well as a short-circuit switch 214 . The short circuit switch 214 lies in a short-circuit path, which the first and second input port 204 , 206 the bridging unit 202 connects. _{A load resistor R Load} is also provided in this short-circuit path, which when the short-circuit switch, which is open in its initial state, is closed 214 with the battery poles of the secondary battery 200 is connected. In practical embodiments, the load resistor R _{L will} preferably be integrated into a corresponding device or unit, which the switch 214 realized.

As described below, the short circuit switch 214 and the circuit breaker 212 can also be designed as a unit, with the opening of the circuit breaker 212 and closing the short-circuit switch 214 can take place essentially simultaneously or at very short time intervals.

The switches 212 , 214 can be designed so that they are transferred from their initial state to the respective other switching position when the external load resistance R _L falls below a certain value or the _{load current flowing through the external load resistance R L} exceeds a predetermined value. For this purpose, a control unit 216 can also be provided which controls the switches 212 , 214 controls in a suitable manner, also with regard to a timing of the switching operations. The control unit 216 can also have one or more sensors that detect triggering events that lead to switching operations of the switches 212 , 214 should lead. For example, a sensor can be designed in such a way that it detects the current intensity in the external current path, so that the control unit 216 can trigger the necessary switching operations when a predetermined value is exceeded.

Of course, the control unit 216 can also be outside the bridging unit 202 be provided. Likewise, the sensors can also be implemented outside of the control unit, in particular also inside switch units that form the isolating switch 212 or the short circuit switch 214 realize. The control unit 216 is not absolutely necessary if the switches 212 , 214 are designed so that they each react independently to a certain event that makes a switching process necessary.

According to the principle on which the invention is based, a bridging unit has at least the in 10 short-circuit switch shown 214 on. If the current in the external circuit through the external load resistor R _{L exceeds} a predetermined value, the short-circuit switch is activated 214 transferred to its closed position. This makes the load resistance R _{load of} the bridging unit 202 connected to the battery poles or connected in parallel to the external load resistor R _L.

The resistance value of the load resistor R _L is selected to be smaller than the internal resistance R _{i of} the secondary battery 200 . This ensures that the parallel connection of the two resistors R _load and R _{L also has} a total resistance R _{total load} that is smaller than the internal resistance R _{i of} the secondary battery 200 . This places a load on the secondary battery 200 avoided with a load that corresponds essentially or with only impermissibly small deviations to the internal resistance. Operation with power adjustment is therefore avoided, causing the battery cells to ignite and the battery cells or the entire battery to be burned off 202 is avoided.

Assigns the bridging unit 202 , as in 10 shown, also a circuit breaker 212 on, so can in addition to bridging the battery poles of the secondary battery 200 by means of the load resistance R _load, a disconnection of the external circuit with the external load resistance R _L from the secondary battery 200 can be achieved.

If the short-circuit switch is actuated 214 and the circuit breaker 212 essentially simultaneously or at short intervals, an arc can arise between the contacts of the disconnector 212 be prevented. If the contacts of the disconnector are opened 212 after the short-circuiting of the battery poles by means of the short-circuit switch 214 , this prevents the occurrence of an electric arc from the outset. The disconnector is actuated 212 shortly after pressing the short-circuit switch 214 , an arc is created between the contacts of the circuit breaker 212 deleted immediately. For this purpose, the short-circuiting must take place within a period of approx. 1 to 1.5 ms in order to prevent the arc from developing in a stable manner.

Assigns the bridging unit 202 both a circuit breaker 212 as well as a short circuit switch 214 on, the short-circuit switch can after the external current path has been disconnected by means of the isolating switch 212 can also be opened again. In this way, the secondary battery can be saved and is not continuously discharged. In particular, a deep discharge that is harmful to the battery is avoided.

For this purpose, the short-circuit current path between the two input ports of the bridging unit 202 be separated again. This can either be done by means of a short circuit switch 214 take place, which can be transferred again from its closed working position to its open position or by means of a second, in 10 further disconnector, not shown, which is connected to the short-circuit switch 214 or the load resistor R _{load is connected} in series, ie is in the short-circuit path. This further isolating switch can also be controlled via the control unit 216 in such a way that the desired time sequence results, that is to say first the isolating switch 212 and the short circuit switch 214 actuated essentially at the same time (or initially the short-circuit switch 214 and the disconnector is delayed 212 actuated) and then the further disconnector in the short-circuit path can be actuated.

The following are a number of embodiments for short circuit switches 214 or disconnector 212 or combinations thereof based on the 1 to 9 explained in more detail. The 1 to 9 the connection contacts for the relevant switches, as well as in 10 , denoted by the reference characters A to D, the relevant contacts A, B and C, D in the embodiment in FIG 10 with the input ports 204 , 206 or the output ports 210 , 208 the bridging unit 202 are identical.

1a shows a short-circuit switch (hereinafter the short-circuit switch 214 in 10 also known as a short-circuit switch) with a switching piston 1 , which can be designed, for example, as a stable contact finger. The short-circuit switch has an electrical contact 2 which is connected to a first terminal of the secondary battery. Furthermore, the short-circuit switch also has an electrical contact 11 connected to the second terminal of the secondary battery. The electrical contacts 2 and 11 are at a fixed distance from the housing 3rd kept that the electrical contacts 2 and 11 firmly connects. The electrical contact 11 is in the short-circuit switch with the electric switching piston 1 electrically connected. The shift piston 1 can be moved in the direction of its axis of extension and is thereby made of the electrical contact 11 that this surrounds the shift piston 1 leads. The shift piston 1 is preferably conically shaped at its tip, so that it is in a preferably also narrowing area section of the electrical contact 2 can retract precisely. This puts the switching piston directly into electrical contact 2 shot in. Alternatively, however, it can also enter a commercially available multi-contact there. The contact 2 can also be designed so that the switching piston 1 digs in here during its flight and thus a good contact with the electrical contact 2 manufactures. Due to the precise design of the electrical contact 2 and electrical contact 11 can be a direct welding of the piston to the two contacts 2 and 11 can be achieved. The shift piston 1 has electrical contact on his 2 remote end preferably a piston-side latching / travel limitation, which is preferably designed in the form of a thickening of the piston. The electrical contact is exactly the same 11 at the end of its leadership for the switching piston 1 a piston-side locking / travel limitation 6th on, preferably as a narrowing of the electrical contact 11 limited piston shaft is formed. 1b shows the short-circuit switch of the 1a in its master position, in which the piston-side locking 7th of the piston 1 at the latch 6th arrived and here in electrical contact 11 is firmly pressed in, as with reference number 9 shown. Reference number 10 shows how the shift piston 1 is firmly pressed into the receiving bore for the accelerated piston, preferably tapering. The short circuit switch after 1a and 1b has an activatable drive 4th , preferably in the form of a gas generator, which is able to bring the switching piston from the separating into the switching position when activated. If the short-circuit switch is in the switch position ( 1b) , so is between the activatable drive 4th and the piston 1 a gas-filled room 8th after the activatable drive has been triggered 4th arises.

Instead of the in 1a and 1b drawn gas generator as an activatable drive 4th a finished force element can also occur, with in front of the switching piston 1 no gas cushion would be built up. In this case the piston could 1 or the membrane of the force element then the switching piston 1 push and thus accelerate. The force element can also be closed off by a membrane folded like an accordion. The acceleration of the switching piston would also be conceivable here 1 by impulse transmission, for example if there is a distance greater than 0 mm between the piston compensation surface of a force element and the underside of the piston. In this case, the smaller switching piston or the membrane of a force element would first be accelerated to almost or up to the final speed and then onto the switching piston 1 impinge and so its previously achieved impulse on the switching piston 1 transfer. With an optimal design of the power element piston and switching piston 1 this would further shorten the switching time. The free distance between a force element and the switching piston 1 is preferably at a distance of between 1 mm and 10 mm with regard to the desired short switching time.

The short-circuit switch, as it is for example in the 1a and 1b is shown, can also contain a sensor, for example a wire or glass fiber or PVDF sensor, which is preferably arranged so that the sensor is destroyed or crushed or cut when the short-circuit switch changes from the disconnected to the switch position, without this interfering with the short-circuit process or the bridging of the connections of the secondary battery. With a fastener according to the 1a and 1b Such a sensor would, for example, be in the mounting hole 5 are located. Such a sensor could also be made through a transverse hole in the electrical contact 2 be guided and by the retracting piston 1 be destroyed. About the cutting effect of the moving piston 1 to can reinforce the front of the shift piston 1 be ring-shaped like a cutting edge. About the welding or pressing of the switching piston 1 in electrical contact 11 and about the transition resistance after the piston has been retracted or pressed on 1 the shift piston can improve 1 be designed at this point with webs parallel to the flight direction, so that when contact is made with the contact-side latching 6th with the electrical contact 11 bring about a higher surface pressure. The same effect can be achieved if the inner surface of the electrical contact 11 at or near the braking point 6th or locking on the contact side 6th is provided with these webs, in which case the switching piston 1 preferably these webs are not required themselves. In addition, the contact-side locking 6th in electrical contact 11 and / or the switching piston 1 be made slightly conical at this point in order to facilitate the pressing through the wedge surfaces. The webs on the shift piston 1 on the contact-side latching used as the press point 6th or in electrical contact 11 are also useful to prevent a double fit through the press point and the mounting hole. In order to further improve the pressure or the contacting, the mounting hole 5 inside also with webs / millings parallel to the flight direction of the switching piston 1 be equipped, or vice versa there again only the switching piston 1 be equipped with these webs parallel to the flight direction.

2a and 2 B show a short circuit switch with a membrane 17th in the separated position of the 2a and the membrane 19th in the control center of 2 B . The short-circuit switch contains an activatable drive 18th , for example a lighter, a gas generator or a detonator, in one of the electrical contact 22nd and the membrane 17th closed to the outside. This enclosed space contains a fluid or gel filling 21 to reduce the void volume in the combustion chamber of the activatable drive 18th to reduce and / or the shock wave propagation between activatable drive 18th and membrane 17th to offer the smallest possible shock wave resistance. On the electrical contact 22nd opposite side of the membrane 17th there is another electrical contact at a certain distance 20th . The contact 20th is connected according to the invention to a first electrical connection of the secondary battery, the electrical connection 22nd is electrically connected to a second electrical terminal of the secondary battery. When activating the activatable drive 18th there is an expansion of the propellant contained therein, for example, so that the of the membrane 17th and the electrical contact 22nd surrounding space expands and the membrane 17th against electrical contact 20th is pressed. Because the membrane 17th or the stretched membrane 19th is electrically conductive, the electrical contacts are 20th and 22nd connected with each other.

3a shows the schematic representation of a short-circuit switch with a contact plate 12th and the electrical contacts 23 and 24 . The electrical contact 23 is according to the invention connected to the first electrical connection of the secondary battery, the electrical contact 24 is connected to the second electrical terminal of the secondary battery. In 3a is the electrically conductive contact plate 12th not in contact with the electrical contacts 23 and 24 so that the short-circuit switch is in the disconnected position. The short-circuit switch also has an activatable drive 13th on, which can be a force element, for example, and when a plunger / piston of the activatable drive is activated 13th , with the plunger / piston 14th with the contact plate 12th is connected, the contact plate 12th against the electrical contacts 23 and 24 presses. As the contact plate 12th is electrically conductive, there is a connection between the electrical contacts 23 and 24 produced, whereby according to the invention a bridging of the first and the second terminal of the secondary battery takes place.

The 4a and 4b also show the schematic representation of a short-circuit switch with a contact plate 12th and the electrical contacts 23 and 24 . The short circuit switch of the 4a and 4b is essentially no different from the short-circuit switch from the 3a and 3b , however, has the difference that the contact plate 12th not at the transition from the disconnected to the control position against the electrical contacts 23 and 24 pressed, but by the actuatable drive designed as a pin-puller drive 15th is pulled. Here, too, is the contact plate 12th with the pin puller drive 15th preferably via a pull rod 16 of the activatable drive 15th connected.

The 5a and 5b basically show a similar short-circuit switch as the 3a and 3b , in each case in the disconnected position and in the master position, but with the difference that the contact plate 30th Contains two contact pins that fit precisely to the multi-contacts on the contact side 26th and 27 are shaped. The multi-contacts on the contact side 26th and 27 are on the multi-contact carriers 32 and 33 appropriate. The multi-contact on the contact side 26th is according to the invention with the first connection of the secondary battery and the contact-side multi-contact 27 electrically connected to the second terminal of the secondary battery.

The 6a and 6b show a similar connecting element as the 5a and 5b , each in control and disconnected position, but here are the electrical contacts 34 and 35 designed as contact pins that fit precisely on the contact plate 31 located multi-contacts (plate side) are formed.

7a and 7b show a first embodiment of a short-circuit / disconnector that can be used according to the invention 110 (hereinafter referred to only as switches). This switch 110 has a housing 112 on, which can be made substantially cylindrical. The case 112 has a base side 114 (left side) on which also the third contact 128 and the second contact 130 , preferably isolated from one another. In the interior 118 of the housing 112 are each from the third contact 128 and the second contact 130 Sections of fasteners 122 running parallel to each other up to the release element 124 present, the one at the base 114 with the third and second contact 128 , 130 and on the other side with the release element 124 are connected. The two parallel sections of the connecting elements 122 are also located along the release element 124 electrically in contact with each other so that the two sections of the connecting elements 122 from the third contact 128 up to the second contact 130 are connected in series. The second contact is led from the base side to the side opposite the base side. The side opposite the base side is composed of at least two electrically conductive parts, which are each insulated from one another. The first part is the part that has the second contact 130 connected is. The second part is the first contact 131 . The sections of the fasteners 122 preferably have mechanical cross-sectional weakenings 123 on, so that when the release element moves 124 in the direction of the side opposite the base side, the sections of the connecting elements 122 tear at these points. This way the connection between the third contact is made 128 and the second contact interrupted. The release plate is preferably itself electrically conductive and is preferably moved so far that it touches the first and the second part of the side of the housing opposite the base side. In this way, an electrical contact is established between the first and the second contact. Between the release element 124 and the base 114 inside the case 112 there is an activatable drive 126 with a drive housing 136 and a drive piston 138 , the one with the release element 124 communicates. In 7th is the activatable drive 126 designed as a gas pressure drive inside the drive housing 136 has a combustion chamber which, when ignited, the drive piston 138 against the release element 124 presses. Thus, the sections of the connecting elements tear 122 at the cross-sectional weaknesses 123 and on each of the sections of the connecting elements 122 separation points are brought about, which the electrical current flow between the third contact 128 and the second contact 130 break through.

8a and 8b show a further embodiment of a switch which can be used according to the invention 110 . This switch is essentially like the one in 7a and 7b The switch shown is constructed, with the difference that it has four sections of connecting elements 122 as well as a collector 132 having. The one with the third contact 128 and the second contact 130 connected sections of the connecting elements 122 are at the bottom 114 as well as on the release element 124 attached. These sections of the connecting elements connected to the contacts 122 stand over two more sections of fasteners 122 in contact with each other, as well as with the release element 123 on one side and on the other side (base side) with a collector 132 are connected, which also these two sections of the connecting elements 122 electrically connects to each other. Becomes the release element 124 towards that of the base side 114 opposite side through the activatable drive 126 Moved in the middle of the case, so do not just tear, as in the embodiment of the 7th , two fasteners 122 at the cross-sectional weaknesses 123 but all four sections of the fasteners 122 . Such an embodiment thus increases the security of the switch that can be used according to the invention.

9a and 9b show a first embodiment of a short-circuit / disconnector that can be used according to the invention 110 (hereinafter referred to only as switches). This switch 110 has a housing 112 on, which can be made substantially cylindrical. The case 112 has a base side 114 (left side) where the third contact 128 is present. In the interior 118 of the housing 112 are from the third contact 128 two sections of fasteners 122 running parallel to each other up to the opposite side where they make the second contact 130 are connected. Furthermore, the connecting elements 122 with the release element 124 firmly connected, which is also electrically conductive. The side opposite the base side is composed of at least two electrically conductive parts, which are each insulated from one another. The first part is the second contact 130 . The second part is the first contact 131 , which is preferably in the middle of the second contact 130 is located. The sections of the fasteners 122 preferably have mechanical cross-sectional weakenings 123 on, so that when the release element moves 124 in the direction of the side opposite the base side, the sections of the connecting elements 122 tear at these points. This way the connection between the third contact is made 128 and the second contact interrupted. The release plate is preferably itself electrically conductive and is preferably moved so far that it touches the first and the second part of the side of the housing opposite the base side. In this way there is electrical contact between the first and the second contact 130 , 131 produced. Between the release element 124 and the base 114 inside the case 112 there is an activatable drive 126 with a drive housing 136 and a drive piston 138 , the one with the release element 124 communicates. In 9 is the activatable drive 126 designed as a gas pressure drive inside the drive housing 136 has a combustion chamber which, when ignited, the drive piston 138 against the release element 124 presses. Thus, the sections of the connecting elements tear 122 at the cross-sectional weaknesses 123 and on each of the sections of the connecting elements 122 separation points are brought about, which the electrical current flow between the third contact 128 and the second contact 130 break through.

All switches after 7th to 9 can also be designed in such a way that their connecting elements melt at the predetermined points with a weakened cross-section due to an increased current flow through the connecting elements in the event of an external short circuit and thus cause a (passive) separation of the connecting elements. Switches designed in this way can thus be triggered both actively, ie controllably, and passively, ie by exceeding a nominal current. In addition, the switches can also be designed in such a way that active triggering is dispensed with and only passive triggering is possible.

This passive switch-off can be homogenized by surrounding the separation points with an ignition mixture which ignites at these points of the connecting elements at a certain temperature, which is increased due to the increased current flow. This means that the separation points are additionally or further heated and the material is melted there faster than by the triggering current flow alone.

Of course, a secondary battery that is to be short-circuited in a targeted manner using the method according to the invention must be suitable for this. As a rule, however, this is the case with all secondary batteries known as intrinsically safe that are available today.

List of reference symbols

1

Switching piston, preferably slightly tapered at the front and over the entire length, with or without webs on the outside

2

electrical contact, with a connector 1 connected to the secondary battery

3

Housing, connects the electrical contacts of the short-circuit switch

4th

activatable drive, for example gas generator or power element

5

Location hole for accelerated piston, possibly tapered, pressing point

6th

Latching on the contact side / travel limiter for pistons

7th

piston-side locking / travel limiter

8th

Gas-filled space after the activatable drive has been triggered 4

9

locking on the piston side 7th of the piston 1 on contact-side latching 6th arrived and here in contact 11 firmly pressed in

10

Piston cone in a tapered bore 5 firmly pressed in

11

electrical contact, with a connector 2 connected to the secondary battery

12th

Contact plate

13th

activatable drive or force element

14th

Plunger / piston of the activatable drive 13th

15th

activatable drive, e.g. pin-puller drive

16

Pull rod of the activatable drive 15th

17th

Membrane, electrically conductive

18th

Activatable drive, e.g. igniter, gas generator or detonator

19th

membrane 17th , deformed after activation of the activatable drive 18

20th

electrical contact, with a connector 1 connected to the secondary battery

21

Fluid or gel filling

22nd

electrical contact, with a connector 2 connected to the secondary battery

23

electrical contact, with a connector 1 connected to the secondary battery

24

electrical contact, with a connector 2 connected to the secondary battery

25th

Fluid / gel filling after triggering or passage of the shock wave generated by the activatable drive 18

26th

multi-contact on the contact side 1

27

multi-contact on the contact side 2

28

plate-side multi-contact 1

29

plate-side multi-contact 2

30th

Contact plate with contact pins

31

Contact plate with multi-contact inserts

32

Multi-contact carrier for contact 1

33

Multi-contact carrier for contact 2

34

Contact pin for contact 1

35

Contact pin for contact 2

110

Short circuit / disconnector

112

casing

114

Base side of the housing

118

Interior of the case

120

Isolator medium

122

Fasteners

123

Cross-sectional weakening

124

Release element

126

activatable drive

128

third contact

130

second contact

131

first contact

132

collector

136

Drive housing

138

Drive piston

200

Secondary battery

202

Bridging unit

204

first input port

206

second input port

208

first output port

210

second output port

212

Disconnector

214

Short circuit switch

Claims (12)

Method for targeted short-circuiting of a secondary battery (200), wherein the electrical connections of the secondary battery (200) are electrically bridged with a bridging unit (202), wherein the bridging unit (202) comprises a short-circuit switch (110, 214) which is switched from a disconnected position to a Control position can be transferred, and wherein the bridging unit (202) has a load resistance R _load between the electrical connections of the secondary battery (200 _{) in a short-circuit switch (110, 214) located in the control position, which is below the internal resistance R i of} the secondary battery (200) the short-circuit switch (110, 214) has an electrically conductive switching piston (1), an electrically conductive membrane (17, 19) or an electrically conductive contact plate (12, 30) as the switching element, the switching element at the transition from the separating is subjected to a movement in the control position of the short-circuit switch (110, 214), and thereby i connects two contacts of the short-circuit switch (110, 214) to one another, whereby the electrical connections of the secondary battery (200) are bridged. Procedure according to Claim 1 , wherein the load resistance R _{load is} at least 10% below the internal resistance R _{i of} the secondary battery (200). Method according to one of the preceding claims, wherein the bridging unit (202) or the external current path have a disconnector (110, 212) which is transferred from a closed position to an open position in the event of a short circuit in the external current path. Procedure according to Claim 3 , the electrical connections of the secondary battery (200) being electrically bridged in the event of a short circuit in the external current path by closing the short-circuit switch (110, 214) if the isolating switch (110, 212) does not switch off the current in the external current path. Procedure according to Claim 3 In the event of a short circuit in the external current path, the short circuit switch (110, 214) is closed and the Isolating switch (110, 212) is opened, or in the event of a short circuit in the external current path, first the short-circuit switch (110, 214) is closed and then the isolating switch (110, 212) is opened. Method according to one of the preceding claims, wherein the secondary battery (200) is a Li battery or Li-ion battery. Method for targeted short-circuiting of a secondary battery (200), wherein the electrical connections of the secondary battery (200) are electrically bridged with a bridging unit (202), wherein the bridging unit (202) comprises a short-circuit switch (110, 214) which is switched from a disconnected position to a Control position can be transferred, and wherein the bridging unit (202) has a load resistance R _load between the electrical connections of the secondary battery (200 _{) in a short-circuit switch (110, 214) located in the control position, which is below the internal resistance R i of} the secondary battery (200) The bridging unit (202) is designed as a short-circuit / disconnector (110), (a) which can be transferred from a first position to a second position, (b) which has a housing (112), a first contact (131 ), a second contact (130), a third contact (128), a release element (124) movable in the housing and at least one Having connecting element (122) which, in the first position of the switch (110), establishes an electrical connection between the third contact (128) and the second contact (130), (c) wherein the housing (112) has the at least one connecting element ( 122) surrounding interior space (118) and (d) wherein the at least one connecting element (122) at one end on the base side (114) of the housing (112) and at the other end on the release element (124) inside the housing ( 122) is attached, and (e) which is designed so that a mechanical movement of the release element (124) can transfer the switch (110) from the first position to the second position, the release element (124) mechanically so on the im At least one connecting element (122) running inside the interior has the effect that the electrical connection between the third contact (128) and the second contact (130) is interrupted at at least one separation point of the connecting element (122), and d abei a connection between the first (131) and the second contact (130) is created. Method according to one of the Claims 1 to 7th , wherein the movement of the switching element is carried out by an activatable drive (126). Procedure according to Claim 8 , wherein the activatable drive (126) is designed as an inductive drive, as an eddy current drive, as a pin-puller drive or as a gas pressure drive, in which the gas pressure is generated by means of a gas-generating material. Electrical circuit with a secondary battery (200) and a bridging unit (202) which is connected to an external current path which has an electrical consumer, the bridging unit (202) having a current path for bridging the electrical connections of the secondary battery (202), in which a selectively triggerable short-circuit switch (110, 214) is provided, which can be transferred from a disconnected position to a control position, and wherein the current path of the bridging unit (202) in the control position of the short-circuit switch (110, 214) has a load resistance R _load that is lower is as the internal resistance R _{i of} the secondary battery (200), the short-circuit switch (110, 214) having an electrically conductive switching piston (1), an electrically conductive membrane (17, 19) or an electrically conductive contact plate (12, 30) as a switching element , the switching element during the transition from the disconnected to the switching position of the short-circuit scarf ters (110, 214) is subjected to a movement, and thereby connects two contacts of the short-circuit switch (110, 214) to one another, whereby the electrical connections of the secondary battery (200) are bridged. Electrical circuit according to Claim 10 wherein the bridging unit (202) has an isolating switch (110, 212) that can be transferred from a control position to a disconnected position for disconnecting the external current path. Electrical circuit with a secondary battery (200) and a bridging unit (202) which is connected to an external current path which has an electrical consumer, the bridging unit (202) having a current path for bridging the electrical connections of the secondary battery (200), in which a selectively triggerable short-circuit switch (110, 214) is provided, which can be transferred from a disconnected position to a control position, and wherein the current path of the bridging unit (202) in the control position of the short-circuit switch (110, 214) has a load resistance R _load that is lower is as the internal resistance R _{i of} the secondary battery (200), the bridging unit (202) being designed as a short-circuit / isolating switch (110), (a) which can be transferred from a first position to a second position, (b) which is a Housing (112), a first contact (131), a second contact (130), a third contact (128), an in Gehä Use movable release element (124) and at least one connecting element (122) which, in the first position of the switch (110), establishes an electrical connection between the third contact (128) and the second contact (130), (c) wherein the housing (112) has an interior (118) surrounding the at least one connecting element (122) and (d) wherein the at least one connecting element (122) is attached at one end to the base side (114) of the housing (112) and at the other end to the release element (124) inside the housing (112), and (e) which is designed so that a mechanical movement of the release element (124) can transfer the switch (110) from the first position to the second position, the release element (124) mechanically acting on the at least one connecting element (122) running in the interior that the electrical connection between the third contact (128) and the second contact (130) is interrupted at at least one separation point of the connecting element (122), and a connection between the first (131) and the second contact (130) is created.

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