Motor vehicle disconnector

Abstract

The invention relates to a motor vehicle disconnector based on a connecting piece that can be magnetized according to the temperature.

Description

[0001] Automotive isolator switch

[0002] The subject matter relates to a motor vehicle isolating switch, in particular for securing a battery cable in a motor vehicle, and to a motor vehicle having such a motor vehicle isolating switch.

[0003] As electrification progresses, increasingly high levels of power must be transferred between energy sources (generators and storage devices) and consumers in motor vehicles, particularly between the battery and the drive. This is usually done via electrical energy conductors such as cables, and high electrical voltages are preferably used. Nevertheless, electrical connections in the drive train and the charging electrical system in particular carry high electrical currents, at least temporarily, so that electrical conductors can heat up locally due to ohmic losses. The temperatures reached in this process can be dangerous for the energy conductor itself, for example for its insulation, and in the worst case scenario, can trigger a cable fire. High cable temperatures can also be dangerous for components located in close proximity to the heated part of the cable. Last but not least, this puts the safety of the driver at risk.

[0004] The temperature of a power conductor can be determined, for example, using suitable sensors, such as temperature-dependent electrical resistors, and subsequently analyzed. This typically requires evaluation electronics, which in turn carries a risk of failure, not least due to the typically highly demanding environment of a motor vehicle and, in particular, the high temperatures that may occur in power conductors. US 2020 / 0 083 513 A1 discloses a battery pack comprising batteries, at least one electronic control system, and at least one electrical switching means, wherein the switching means comprises at least one contact piece, at least one locking plate, and at least one magnetic latch.

[0005] DE 1 523 402 A describes a temperature-controlled control element comprising a permanent magnet, a thermoferrite bridge and a spring, wherein the thermoferrite attraction force or the spring force predominates depending on the temperature.

[0006] WO 2021 / 128859 A1 discloses a temperature controller comprising a temperature-sensitive soft magnet, a hard magnet, a spring arranged between the temperature-sensitive soft magnet and the hard magnet, and a contact piece. When the warm soft magnet and the hard magnet are magnetically attracted, the contact piece overcomes the elastic force of the spring and closes a connection. When the soft magnet loses its magnetism, however, the spring force prevails and the connection is broken.

[0007] Magnetic switches are also disclosed, for example, in CN 22 38481 Y, CN 115938 859 A and CN 2148390 Y.

[0008] Therefore, the object of the invention was to provide temperature monitoring for a power conductor in a motor vehicle, which is simple and fail-safe and provides reliable countermeasures, particularly in the case of critically excessive power conductor temperatures.

[0009] This object is achieved by a motor vehicle circuit breaker according to claim 1 and a motor vehicle according to claim 15. The disclosed motor vehicle circuit breaker comprises a first connection lug and a second connection lug.

[0010] A respective connecting lug is in particular formed from a metal material. For example, a connecting lug can be formed at least partially or entirely from aluminum or an aluminum alloy and / or from copper or a copper alloy.

[0011] A respective connection lug can be formed, for example, as a conductor, preferably as a flat conductor. A flat conductor can have a rectangular cross-section. The rectangular cross-section can have two broad sides that are essentially parallel to one another and two narrow sides that are essentially perpendicular to the broad sides and parallel to one another. The narrow sides are shorter than the broad sides. The cross-section of the respective connection lug can, in particular, be constant along a longitudinal direction of the connection lug, wherein the longitudinal direction runs, in particular, essentially perpendicular to the cross-section of the connection lug and / or perpendicular to the broad sides and narrow sides.

[0012] If two surfaces and / or directions are described as being substantially parallel to one another, they enclose an angle of 0° between one another, for example, with a maximum deviation in amount of 1°, 2°, 3°, 5°, or 10°. If two surfaces and / or directions are described as being substantially perpendicular to one another, they enclose an angle of 90° between one another, for example, with a maximum deviation in amount of 1°, 2°, 3°, 5°, or 10°. If two surfaces and / or directions are described as being substantially antiparallel to one another, they enclose an angle of 180° between one another, for example, with a maximum deviation in amount of 1°, 2°, 3°, 5°, or 10°. For each connecting lug, an end face can be defined which is oriented substantially perpendicular to the longitudinal direction.For example, the shape of the end face can essentially correspond to the cross-sectional area of ​​the connecting lug.

[0013] At least one of the connecting lugs or the connecting lugs can, in particular, be part of a respective flat conductor. The two connecting lugs can, for example, be part of one and the same flat conductor, which is separated into two parts by an interruption.

[0014] For example, the cross-sectional area of ​​the first connecting lug can essentially match the cross-sectional area of ​​the second connecting lug. For example, the two cross-sectional areas can match each other, except for tolerances in the manufacturing process of the respective connecting lug.

[0015] The first connection lug and the second connection lug are spaced apart from each other by a gap. The gap spans in particular between the two end faces of the first and the second connection lug. The gap extends, for example, in the longitudinal direction of at least one and / or both connection lugs. The first connection lug and the second connection lug can, for example, be aligned with each other. In other words, the two connection lugs are arranged, for example, in such a way that a displacement of one of the connection lugs along its longitudinal direction towards the other connection lug would lead to full-surface contact between the two end faces of the two connection lugs. However, such contact is to be avoided. The connection lugs are fixed to each other. For example, at least two respective broad sides of the at least two connection lugs lie in a common spatial plane.The first connecting lug and the second connecting lug can also be arranged offset from one another, for example along a direction parallel to at least one respective broad side and / or narrow side of one of the two connecting lugs.

[0016] The gap between the two connecting lugs can have a substantially constant width across the end face of at least one of the two connecting lugs. The width of the gap can be defined, in particular, as the distance between the end faces of the connecting lugs in the longitudinal direction of at least one of the connecting lugs.

[0017] The gap can be filled, for example, with a non-conductive material. For example, the gap can contain air, another gas, such as an inert gas or a protective gas, such as sulfur hexafluoride (SF6). The gap can also essentially contain a vacuum. An electrically insulating solid, such as a plastic, glass, ceramic, and / or combinations thereof, can also be arranged in the gap.

[0018] The disclosed automotive circuit breaker further comprises a connector. The connector electrically connects the first terminal lug and the second terminal lug in a closed position of the automotive circuit breaker.

[0019] The connecting piece can, for example, be formed at least partially from a metal material. The connecting piece can, for example, comprise aluminum or an aluminum alloy and / or copper or a copper alloy. For example, the connecting piece can be formed at least partially from the same material as at least one of the or both of the connecting lugs. The connecting piece can thus be at least partially magnetically neutral, in particular non-ferromagnetic or paramagnetic, for example in the case of aluminum, and / or partially diamagnetic, for example in the case of copper.

[0020] The connecting piece is at least partially ferromagnetic. In particular, a portion of the connecting piece is ferromagnetic, which is referred to as the magnetic part.

[0021] Due to its ferromagnetic properties, the connecting piece is magnetized in spatial proximity to a magnetic field, for example triggered by a magnetic element, such as an electromagnet and / or a permanent magnet.

[0022] The connecting piece can, for example, at least partially comprise a ferromagnetic material. In other words, a part (in particular the magnetic part) of the connecting piece can comprise a ferromagnetic material. Ferromagnetic materials include, for example, cobalt, iron, nickel, steel, cobalt-iron, silicon-iron, and nickel-iron.

[0023] The connecting piece may in particular comprise a ferrite. The connecting piece may, for example, comprise a soft magnetic ferrite. A soft magnetic ferrite may, for example, be a manganese-zinc ferrite (MnZn), for example in the composition Mn a Zn(i- a jFe2O4 or Mn a Zno.4Cao.6-2 a Fe2+a 04 and / or a nickel-zinc ferrite (NiZn), for example in the composition Ni a Zn(i- a jFe2O4. The connecting piece may alternatively or additionally comprise a hard magnetic ferrite. Examples of hard magnetic ferrites include strontium ferrites, for example, in the composition SrFe2O9, barium ferrites in the composition BaFe2O9, and cobalt ferrites in the composition CoFe2O4.

[0024] The connecting piece can be constructed from at least two parts, in particular two layers. A first part, in particular a first layer, can be a ferromagnetic magnetic part or magnetic layer, for example a ferrite. A second part, in particular a second layer, can be formed as a conductive layer from a metal material such as aluminum or an aluminum alloy and / or copper or a copper alloy.

[0025] The conductive layer can face the connecting tabs and, for example, contact them in the closed position. The conductive layer can be connected to the magnetic layer, for example, by a material fit, a form fit, and / or a force fit. For example, an insulator and / or a thermally conductive element such as a thermal paste can be arranged between the magnetic layer and the conductive layer. The at least two-layer design of the connector allows for a high current-carrying capacity through the conductive layer while simultaneously maintaining malleable magnetic properties thanks to the magnetic layer.

[0026] The connecting piece is arranged on a first side of the connecting lugs. For example, the connecting piece can be arranged on the side of two broad sides of the two connecting lugs. In the closed position, the connecting piece can rest on the broad side of at least one or both connecting lugs. For example, the connecting piece can touch the connecting lugs at a respective contact surface. The respective contact surface can in particular be arranged on a respective broad side of the connecting lugs.

[0027] The contact surfaces of the respective connection lugs can be substantially flat. In particular, the contact surfaces on the side of the connecting piece and / or on the side of the respective connection lug can be substantially flat, such that the contact surfaces do not deviate from a flat surface beyond the usual manufacturing tolerances. For example, at least one of the connection lugs can comprise a contact surface that deviates from a flat surface. In particular, the contact surface of at least one of the connection lugs can be structured congruently with the contact surface of the connecting piece that is in contact with it. For example, the contact surface can have at least one elevation and / or one depression into which the connecting piece engages in the closed position. The contact surfaces on the connecting piece and connection lug can also each be convexly curved towards one another.

[0028] If the contact surfaces can also be designed in a planar manner, the connecting piece in the closed position rests essentially over its entire surface on one of the connection tabs on a contact surface.

[0029] In the area of ​​a respective contact surface, at least one of the terminal lugs and / or the connecting piece can be coated. In particular, the respective coating can be formed from a metal material, for example, zinc, nickel, and / or combinations thereof. The coating materials of a terminal lug and the connecting piece contacting it can be identical.

[0030] The disclosed motor vehicle disconnect switch further comprises a spring element. The spring element exerts a spring force on the connecting piece. For example, the spring force is exerted between at least one of the terminal lugs and the connecting piece. The spring force is directed in particular in the direction of a displacement of the connecting piece from the closed position to an open position. The spring element, in particular, exerts a permanent spring force on the connecting piece. The connecting piece can be moved along the displacement direction. In particular, the connecting piece can be moved along the displacement direction, but not perpendicular to the displacement direction. The connecting piece can thus be blocked perpendicular to the displacement direction. The displacement direction can be predetermined, for example, by a guide.The displacement direction can, for example, be oriented substantially parallel to at least one of the broad sides of at least one of the connecting lugs. The displacement direction can, for example, be oriented substantially perpendicular to at least one of the broad sides of at least one of the connecting lugs.

[0031] In the open position, the first terminal lug and the second terminal lug are electrically insulated from each other. The electrical insulation is achieved, in particular, by the gap between the terminal lugs. At least one of the two terminal lugs is electrically insulated from the connector in the open position. For example, a further gap may be present between the connector and at least one and / or both terminal lugs in the open position.

[0032] Because the spring element exerts a spring force on the connecting piece, which is directed in the direction of displacement, the spring element acts as an opener for the automotive circuit breaker. In other words, the spring element is designed to open the automotive circuit breaker. Without counterforce, the spring element ensures a permanent electrical separation of the two connecting lugs.

[0033] The spring element can be formed as a separate component from the terminal lugs and the connecting piece. Alternatively or additionally, the spring element can be formed as part of one of the terminal lugs and / or the connecting element. The automotive disconnect switch further comprises a magnetic element. The magnetic element is arranged on a second side of the terminal lugs, opposite the first side.

[0034] For example, the connecting piece can be arranged on the side of a respective first broad side of the connecting tabs, while the magnetic element is arranged on the respective other broad side of the connecting tabs.

[0035] The magnetic element exerts a holding force on the connecting element. This holding force acts opposite to the direction of displacement. The holding force is specifically the component of the force exerted by the magnetic element on the connecting element that acts opposite to the direction of displacement.

[0036] The holding force can be achieved, in particular, by a magnetic attraction between the magnetic element and the connecting piece. Because the connecting piece is at least partially ferromagnetic (in particular the magnetic part), it is attracted by the magnetic field of the magnetic element. In particular, the connecting piece is at least partially magnetized, at least temporarily, by the magnetic element. The magnetized connecting piece is attracted by the magnetic element.

[0037] The holding force can in particular be a component of a magnetic force which is caused by the magnetic element and acts on the connecting piece. The holding force is in particular the component of the magnetic force which acts antiparallel to the direction of displacement. The holding force can for example be caused by a contact pressure of the connecting piece on at least one of the connecting lugs which is exerted by the magnetic element. For example, the direction of displacement can be oriented substantially perpendicular to at least one of the and / or the broad sides of at least one and / or the connecting lugs. In this case, the holding force can press and / or pull the connecting element onto the at least one broad side or sides counter to the direction of displacement. The direction of displacement can also be oriented substantially parallel to at least one of the and / or the broad sides of at least one and / or the connecting lugs.In this case, the holding force also acts parallel to the broad side and is opposite to the direction of displacement.

[0038] The holding force acts in particular on the connecting piece from at least one of the and / or both connecting lugs.

[0039] The magnetic element can be attached to at least one of the connecting lugs, in particular in a force-fitting, form-fitting and / or material-fitting manner.

[0040] The magnetic element is, in particular, electrically insulated from the two connecting lugs. For example, at least one or more insulators can be arranged between the magnetic element and the respective connecting lugs. The magnetic element can, for example, be indirectly attached to at least one of the two connecting lugs via at least one insulator.

[0041] In the closed position, the holding force outweighs the spring force. The spring cannot thus disconnect the automotive circuit breaker against the holding force. This force ratio between the spring force and the holding force is at least partially due to the ferromagnetic properties of the connecting piece (particularly the magnetic part). It was recognized that a temperature dependence of the magnetic properties of the connecting piece can be used to provide an automotive circuit breaker that opens automatically at high temperatures. In particular, it was recognized that the electrical currents achieved in today's electric vehicles can lead to power conductor temperatures at which the magnetic material properties of certain ferromagnetic materials change fundamentally.Furthermore, it was recognized that critical temperatures of today's energy conductors in motor vehicles are in the range of Curie temperatures of some ferromagnetic materials.

[0042] The connecting piece of the motor vehicle circuit breaker in question is at least partially ferromagnetic up to a first limit temperature of the connecting piece, in particular the magnetic part, for example its magnetic layer in the case of a multi-layer connecting piece. From a second limit temperature of the connecting piece, the connecting piece is at least substantially non-ferromagnetic, but may, for example, (continue to be) paramagnetic or diamagnetic. For example, from a second limit temperature, the magnetic part is essentially no longer ferromagnetic. Thus, in particular, only a part of the connecting piece can lose its ferromagnetic properties, in particular the magnetic part, for example the magnetic layer. Other parts, for example the conductive part, in particular the conductive layer, should not have any ferromagnetic properties.Such a change in magnetic material properties occurs particularly at the so-called Curie temperature.

[0043] Ferromagnetic, paramagnetic and diamagnetic materials can be distinguished by their susceptibility X. Diamagnetic materials have a negative value of magnetic susceptibility (X < 0) and accordingly a relative permeability p r less than 1. In the extreme case of a superconductor as a perfect diamagnet, the susceptibility reaches the value X = -1. For paramagnetic materials, the susceptibility has a small (<1) positive value; for ferromagnetic materials, it is very large (> 1, e.g., 500 - 10000 for iron).

[0044] When a material is described as (essentially) non-ferromagnetic, this means in particular that its susceptibility is at most 50, 40, 30, 20, 10, 5, 4, 3, 2 or 1. Conversely, a material can be described as (essentially) ferromagnetic if its susceptibility is more than 1, 2, 3, 4, 5, 10, 20, 30, 40 or 50.

[0045] The first and / or the second limit temperatures can be particularly dependent on the Curie temperature of at least one of the components of the connecting piece.

[0046] The Curie temperature can be specifically influenced by choosing the material composition. Especially with ferrites, such as those mentioned above, the composition can be varied so that the Curie temperature can be adjusted within a range of, for example, 100–300 °C. Curie temperatures below 100 °C are also possible.

[0047] The Curie temperature of a material is advantageously constant. This ensures the correct functioning of the automotive circuit breaker in question over long periods of time. There is no degradation of the response times or sensitivity to temperature changes of the proposed automotive circuit breaker over time.

[0048] The motor vehicle disconnect switch can, in particular, be a motor vehicle battery disconnect switch. In this case, the motor vehicle disconnect switch protects, in particular, a power conductor that leads to an energy storage device and / or supplies other vehicle components, such as the drive train, from an energy storage device.

[0049] According to one embodiment, the first limit temperature is equal to the second limit temperature. Alternatively, the first limit temperature can be lower than the second limit temperature. The second and / or the first limit temperature can be and / or depend on a Curie temperature, in particular a Curie temperature of at least parts of the connecting piece, in particular of at least one ferromagnetic part of the connecting piece, in particular of the magnetic part, for example of the magnetic layer.

[0050] The first and / or second limit temperature depends, for example, on a material composition of at least a part of the connecting piece, in particular a ferromagnetic magnetic part of the connecting piece.

[0051] The first and / or second limit temperature may in particular be below 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C or 150 °C.

[0052] For example, the first and / or second limit temperature may be between 50°C and 150°C, between 60°C and 140°C, between 90°C and 110°C.

[0053] According to one embodiment, the holding force is greater than the spring force by at least a factor of 1.5, 2, 2.5, 3, 4, 5, 10, 15, 20, 30, 40, or 50, as long as the connecting piece (in particular the magnetic part) is ferromagnetic, in particular in the direction of displacement, in particular in the closed position and / or the open position. This ensures that the motor vehicle circuit breaker does not open unintentionally, for example due to shocks and / or vibrations, which can occur in particular in the motor vehicle. When the spring force is compared with the holding force, this comparison can relate in particular to the respective force components that are directed parallel (or antiparallel) to the direction of displacement.

[0054] The motor vehicle circuit breaker can be designed so that the connecting piece does not automatically return to the closed state after transitioning from a ferromagnetic state (e.g. closed position) to the non-ferromagnetic state (e.g. open position). For this purpose, the spring travel and / or the range of movement of the connecting piece along the direction of displacement can be dimensioned such that the attractive force between the magnetic element and the connecting piece in the open position is too small for the switch to close again. This results in permanent separation. For example, a mechanical and / or electromagnetic force can be exerted on the connecting piece to return the motor vehicle circuit breaker to the closed position. An electromagnet can also be used to deliberately weaken the magnetic circuit so that the switch opens even without excess temperature.Strengthening the magnetic field of the open switch then leads to targeted re-switching after the isolating piece has cooled below the Curie temperature.

[0055] The motor vehicle circuit breaker can also be configured such that the magnetic force exerted by the magnetic element on the connector is sufficiently large to transfer the motor vehicle circuit breaker to the closed position when the connector transitions from the non-ferromagnetic state, i.e., in the open position, to the ferromagnetic state. In this configuration, the motor vehicle circuit breaker automatically becomes conductive again as soon as the temperature of the connector drops again.

[0056] According to one embodiment, the spring force is at least

[0057] A factor between 1.5 and 50, in particular 1.5, 2, 2.5, 3, 4, 5, 10, 15, 20, 30, 40, or 50, greater than the holding force when the connecting piece (in particular the magnetic part) is not ferromagnetic, in particular in the direction of displacement, in particular in the closed position and / or the open position. This ensures that the motor vehicle circuit breaker does not accidentally move from the open position to the closed position.

[0058] According to one embodiment, the first and / or second connecting lugs are at least partially enclosed by a housing. In particular, a housing can enclose the first and / or second connecting lugs in the region of the gap. The gap can, in particular, be completely enclosed by a housing. For example, the housing can be fluid-tight and / or gas-tight. The housing can, for example, be filled with a protective gas, such as SF6.

[0059] For example, at least one or both of the connecting lugs can be attached to the housing, for example, by force-fitting, material-fitting, and / or form-fitting. Alternatively or additionally, the magnetic element can be attached to the housing, in particular by material-fitting, form-fitting, and / or force-fitting. The connecting piece can also be guided on the housing, for example. For example, the housing can provide a channel for the connecting piece, in which the connecting piece can move along the direction of displacement. The housing can thus define the direction of displacement of the connecting piece.

[0060] The spring element can be attached to the housing, for example in a force-fitting, form-fitting and / or material-fitting manner. For example, the spring element can also be formed at least partially and / or completely by the housing. The housing can, for example, comprise an elastically deformable wall which forms the spring element. The housing is, for example, injection-molded, for example injection-molded around the encased components. The housing can also, for example, be composed of at least two sub-elements, wherein the at least two sub-elements are connected to one another in a material-fitting, form-fitting and / or force-fitting manner, for example by screwing. At least one seal can be provided between the at least two parts, in particular at the seams which are in contact with the other parts.

[0061] The housing can be mechanically reinforced, for example, with a reinforcement of the housing material, for example with a reinforcement comprising at least one metal strut or a grid and / or mesh of metal struts. By reinforcing the housing, the disclosed motor vehicle circuit breaker can be provided in a flat cable without constituting a mechanical weak point in the flat cable.

[0062] The housing can, for example, be thermally insulated. For this purpose, the housing can, for example, be made at least partially from a material that has low thermal conductivity. For example, the housing can be formed at least partially from a thermal insulator, such as insulating foam, Styrofoam, Styrodur. By making the housing thermally insulated, it can be ensured that the temperature of the connector is not lower than the temperature of the connection lugs in an area outside the housing. Because the heat cannot escape freely from the thermally insulated housing, the connector is warmer than parts of the connection lugs that are not surrounded by thermally insulating material. This can ensure that the motor vehicle circuit breaker electrically disconnects the connection lugs early enough.The first and / or second limit temperature of the connecting piece can also be selected higher than a desired shutdown temperature of the power conductor protected by the motor vehicle circuit breaker. This can be advantageous, for example, to enable a higher Curie temperature for the ferromagnetic material of the connecting piece (in particular the magnetic part). Cooling of the connecting piece delayed by the thermally insulating housing also has the advantage of ensuring that re-contacting of the motor vehicle circuit breaker only occurs once the unenclosed elements, in particular the protected power conductor, have already cooled down again.

[0063] The housing can also be at least partially thermally conductive. This can, for example, ensure thermal monitoring of the immediate vicinity of the motor vehicle circuit breaker.

[0064] According to one embodiment, the connecting piece is arranged in front of at least one of the connecting lugs or both connecting lugs in the direction of gravity. The connecting piece can also be arranged behind at least one of the connecting lugs or both connecting lugs in the direction of gravity.

[0065] According to one embodiment, the spring element comprises a spring. The spring can be, for example, a tension spring, a coil spring, and / or a compression spring. The spring can be formed, for example, from a metal material or from a plastic, in particular a high-temperature plastic.

[0066] The spring element may also comprise a bracket, a rubber element, a braid, a foam and / or combinations thereof.

[0067] The spring element can be electrically conductive. The spring element can be electrically insulating.

[0068] The spring element can be formed as part of the housing. Alternatively or additionally, the spring element can be formed as part of at least one of the terminal lugs and / or the connecting piece. The spring element can, in particular, be electrically insulated from at least one of the terminal lugs or both terminal lugs and / or from the connecting piece, particularly if the spring element is at least partially made of an electrically conductive material.

[0069] According to one embodiment, the magnetic element comprises a permanent magnet. The magnetic element can, for example, be at least partially hard magnetic. The design of the magnetic element comprising a permanent magnet has the advantage that the disclosed motor vehicle circuit breaker can be operated without a power supply. The functioning of the switch is thus independent of an external power supply.

[0070] In particular, the magnetic element exerts, at least in part, a magnetic force on the connecting piece that is substantially parallel to the surface normal to a broad side of at least one or both connecting lugs. For this purpose, for example, a magnetic dipole formed at least locally by the magnetic element can be aligned substantially parallel to the surface normal to a broad side of at least one or both connecting lugs.

[0071] The magnetic element is, for example, at least partially or completely electrically insulated from at least one of the connecting lugs and / or both connecting lugs. At least one insulator can be provided for this purpose. The insulator can, for example, be formed as an electrically insulating layer, such as a film, which is arranged on at least one of the connecting lugs and / or the magnetic element. The insulator can, for example, be formed from a plastic material, a ceramic, glass, and / or combinations thereof.

[0072] The insulator can, for example, be arranged between the magnetic element and the respective connecting lugs. For example, the insulator can electrically insulate at least two parts of the magnetic element from each other. In this case, for example, there can be direct electrical contact between the connecting lugs and the respective parts of the magnetic element.

[0073] The magnetic element does not electrically connect the terminal lugs.

[0074] According to one embodiment, the magnetic element can comprise at least and / or exactly two separate magnets. The magnets can, for example, be magnetized in a direction substantially antiparallel to one another. Alternatively or additionally, one magnet can be provided per connection tab. In particular, for example, a south pole of a first of the magnets can face a first connection tab. A north pole of a second of the magnets can face a second connection tab.

[0075] For example, a connecting element can be arranged between the two magnets. The connecting element can be made of iron and / or a soft magnetic material, for example. By using two magnets and a connecting element between the magnets, a magnetic element can be advantageously formed, which locally exerts a force between the connecting piece and the connecting lugs in the area of ​​the respective connecting lugs. The connecting element can, for example, be electrically insulated from at least one or both magnets, in particular by means of an insulator.

[0076] The magnetic element therefore preferably comprises at least one connecting element, at least two magnets and optionally an insulator.

[0077] The magnetic element, the connecting lugs, and the connecting piece can form a magnetic circuit, particularly in the closed position. The magnetic flux through this magnetic circuit, particularly through the connecting piece, is higher when the connecting piece is at least partially ferromagnetic (particularly the magnetic part of the connecting piece) than when the connecting piece (particularly the magnetic part of the connecting piece) is not ferromagnetic. As a result, the holding force is higher as long as the connecting piece is at least partially ferromagnetic.

[0078] For example, at least one of the two magnets or both magnets can be located in the region of the broad side of a respective connection tab. In other words, in projection parallel to the surface normal to a broad side of at least one of the connection tabs, a respective magnet can lie within the broad side of the connection tab. Alternatively or additionally, the magnet can also lie within a surface of the connecting piece in the direction parallel to the surface normal to the broad side of the connection tab. In particular, the magnet can be dimensioned such that, when projected in this direction, it protrudes neither beyond the surface of the connecting piece nor the surface of the connection tab. In particular, the magnet can be arranged within a contact surface between the connecting piece and the connection tab when projected in this direction. This achieves a particularly high local magnetic flux density in the region of the contact surfaces.

[0079] The magnetic element can also comprise an electromagnet. In this case, assuming the closed position can be dependent on a power supply to the electromagnet. For example, the motor vehicle circuit breaker can thus be used as a security mechanism for theft protection, which only closes when the vehicle is properly unlocked. The magnetic force exerted by the magnetic element on the connecting piece can also be varied with an electromagnet. This can, for example, make it possible to set the first and / or second limit temperature. After a disconnection, the motor vehicle circuit breaker can also be actively moved from the open position to the closed position by a temporarily increased magnetic force. The magnetic element is, for example, fixed to at least one of the two connection lugs, in particular by force-fitting, form-fitting and / or material-fitting.

[0080] For example, the magnetic element can be indirectly connected to at least one of the two connecting lugs via at least one further element, such as an insulator, and in particular fixed to it. Direct attachment of the magnetic element to at least one of the two connecting lugs is also possible.

[0081] According to all embodiments, the displacement direction is aligned substantially perpendicular or substantially parallel to at least one contact surface between the connecting element and at least one of the connecting tabs.

[0082] According to one embodiment, the displacement direction is oriented substantially perpendicular to the direction of gravity. In particular, it was recognized that vibrations in motor vehicles predominantly act substantially parallel to the direction of gravity. By orienting the displacement direction substantially perpendicular to the direction of gravity, vibration-induced openings and closings of the disclosed motor vehicle circuit breaker are counteracted. In particular, the displacement direction can be oriented in this manner when the motor vehicle circuit breaker is installed.

[0083] According to one embodiment, the connecting piece is movably mounted on at least one of the connecting lugs of the conductors. For this purpose, a guide can be provided, for example, in particular at least one rail, at least one hinge, and / or at least one joint. The guide can, for example, specify the direction of displacement. In the case of a movement of the connecting piece on the guide that deviates from a linear movement, for example, in the case of a hinge, the direction of displacement can be defined as the initial displacement direction of the connecting piece from the closed to the open position.

[0084] According to one embodiment, the connecting piece has a minimum cross-section which is smaller than a conductor cross-section of at least one of the connecting lugs. In other words, a narrowing of the cross-section can be present in the region of the connecting piece. For example, in addition to or as an alternative to a difference in the cross-section, the connecting piece can have a lower specific conductance than at least one of the connecting lugs. This can increase the electrical resistance in the region of the connecting piece, relative to the electrical resistance in other parts of the connecting lugs. A current-induced temperature increase will therefore be higher in the region of the connecting piece than in the connecting lugs. This can ensure that an increased temperature is detected early enough by the magnetic effects in the connecting piece, i.e.before other components such as the connection tabs exceed a critical temperature.

[0085] According to one embodiment, the motor vehicle circuit breaker is configured to detect and / or report the open position.

[0086] For example, the connecting element can interact with an electrical and / or electronic component in the open position. For example, the connecting element can open or close a switch, open or close a button, activate or deactivate a touch sensor, activate or deactivate a proximity sensor, and / or activate or deactivate a photodetector in the open position. This can be used, in particular, for signal isolation. The disclosed automotive isolating switch can output a signal when the connecting element interacts with one of the aforementioned components. For example, the automotive isolating switch can apply a signal to a signal line.For example, the motor vehicle circuit breaker can comprise and / or be connected to a signal generator such as a light source, for example, an LED, and / or an acoustic signal generator, for example, a loudspeaker. In the open position, in particular when changing from the closed position to the open position, the aforementioned signal generator can emit a respective signal.

[0087] According to one embodiment, the motor vehicle circuit breaker is not dependent on a power supply. Naturally, when closed, the motor vehicle circuit breaker allows a current to flow through the terminal lugs and the connector. However, according to this embodiment, no further power supply is provided, in particular no power supply that would enable the disconnecting and / or closing function.

[0088] As a further aspect, a motor vehicle is disclosed in which a motor vehicle circuit breaker according to one of the preceding claims is installed. The motor vehicle circuit breaker can secure a power conductor in the motor vehicle. In particular, the motor vehicle circuit breaker could secure a power conductor that leads to an energy storage device of the motor vehicle and / or, from the energy storage device, to other components of the motor vehicle. The motor vehicle circuit breaker can also be arranged, for example, in the area of ​​charging electronics, for example, in a charging cable.

[0089] The subject matter will be explained in more detail below with reference to a drawing showing an exemplary embodiment. The drawing shows: Fig. 1 an exemplary embodiment of a motor vehicle circuit breaker;

[0090] Fig. 2a, b an embodiment of a subject motor vehicle circuit breaker;

[0091] Fig. 3 shows an exemplary diagram of susceptibility depending on temperature;

[0092] Fig. 4a, b a flowchart of the state sequence of the disclosed motor vehicle circuit breaker according to an embodiment;

[0093] Fig. 5 is an isometric view of the disclosed automotive circuit breaker according to one embodiment;

[0094] Fig. 6 is a plan view of a portion of the disclosed motor vehicle circuit breaker according to an embodiment.

[0095] Figure 1 shows a motor vehicle circuit breaker 1. This comprises a first connection lug 102 and a second connection lug 104. In the exemplary embodiment shown, the two connection lugs are guided into a housing 112. Two magnets 122, for example permanent magnets 122, are located in the housing 112. The magnetic polarity of the two magnets 122 is aligned essentially antiparallel to one another. A soft magnetic connecting element 106 is arranged between the magnets 122, which promotes a magnetic flux between the two magnets 122. The connecting element 106 is electrically insulated from the two magnets 122 by an insulator 114. The insulator 114 can alternatively or cumulatively also be arranged between the magnets 122 and the lugs 102, 104.The combination of magnets 122, connecting element 106, and insulator 114 forms the magnetic element 130, which, in the embodiment shown, approximates a horseshoe magnet. The magnets 122 are positioned in such a way that they lie within the surface of the connecting lugs 102, 104 and the surface of the connecting piece 108 in a direction parallel to the surface normal to the broad side of the connecting lugs 102, 104. This maximizes the magnetic flux and thus the attraction between the connecting piece 108 and the connecting lugs 102, 104 for a given dimension of the magnets 122. The magnetic element 130 is arranged on one side of the connecting lugs 102, 104. Furthermore, a spring element 110 is arranged in the housing 112, which exerts a spring force on the connecting piece 108. The motor vehicle circuit breaker is shown in the closed position. The connecting piece 108 contacts the connecting lugs 102, 104 at contact surfaces 120.The connecting piece 108 is constructed in two layers and includes a conductive layer 108b and a magnetic layer 108a. The magnetic layer 108a is formed, for example, from a ferrite.

[0096] Figure 2a shows another embodiment of a motor vehicle circuit breaker. The motor vehicle circuit breaker is in the open position. Unlike the embodiment in Figure 1, the housing 112 is divided into two mutually movable shells, which move with the connecting piece 108 during the transition from the open position to the closed position. Furthermore, the insulator 114 is not arranged between the connecting element 106 and the magnets 122, but rather between the magnets 122 and the respective connecting lugs 102, 104.

[0097] Figure 2b shows the same embodiment of the subject motor vehicle circuit breaker in the closed position.

[0098] Figure 3 shows, by way of example, the effect of temperature on the susceptibility X of a material with a Curie temperature Tc. The exemplary susceptibility X of 1000 below the Curie temperature drops abruptly from the ferromagnetic regime (X » 1, 1000 in the example) upon reaching the Curie temperature Tc to below 1, thus entering the diamagnetic range. For the automotive circuit breaker in question, the temperature Tc can, for example, be in a range of approximately 100 °C. When this temperature is reached by the connecting piece 108, the magnetization generated by the magnetic element 130 drops abruptly. As a result, the holding force decreases significantly (or its direction of action is even reversed, as in the example with a susceptibility X below one), so that the spring force is stronger than the holding force, and the automotive circuit breaker in question switches from the closed position to the open position.After cooling below the Curie temperature, the susceptibility X and thus the magnetic force return to the values ​​before heating.

[0099] The schematic representation of the magnetization of the connecting piece 108 and the magnet 122 of the magnetic element 130 illustrates the microscopic effects within the two materials. A magnet 122 does not lose its magnetic properties with increasing temperature within the temperature range shown. At temperatures below the Curie temperature Tc, the connecting piece 108 is still magnetized by the magnet 122, creating a magnetic force of attraction between the connecting piece 108 and the magnet 122. Above the Curie temperature Tc, however, there is no longer any order within the connecting piece 108 that could cause macroscopic magnetization of the connecting piece 108. Thus, the connecting piece 108 is no longer magnetized by the magnet 122, so the force of attraction is also greatly reduced or zero.

[0100] Figure 4a shows an exemplary flow diagram illustrating the state sequence of the subject motor vehicle circuit breaker 1. In the initial state, the motor vehicle circuit breaker 1 can be in the closed position. Typically, the initial temperatures inside the motor vehicle are lower than the set first and / or second limit temperature Tth. If the temperature T of the connecting piece exceeds the first or second limit temperature Tth, the motor vehicle circuit breaker 1 transitions from the closed position to the open position. Otherwise, it remains in the closed position. In the exemplary embodiment in Figure 4a, the motor vehicle circuit breaker 1 remains in the open position in any case.This can be achieved, for example, by selecting the distance between the magnetic element 130 and the connecting piece 108 in the open position to be so large that the magnetic force is no longer sufficient to overcome the spring force and move the connecting piece 108 back into the closed position, even when the connecting piece 108 cools down.

[0101] In the embodiment shown in Figure 4b, the motor vehicle circuit breaker 1 can automatically return from the open position to the closed position after cooling below the first or second limit temperature Tth. For example, the distance between the magnetic element 130 and the connecting piece 108 in the open position is selected to be small enough so that the magnetic force in the open position, at a temperature of the connecting piece 108 below the first and / or second limit temperature, is strong enough to overcome the spring force.

[0102] Fig. 5 shows an isometric view of a motor vehicle circuit breaker 1. The connecting lugs 102, 104 are inserted laterally into the housing 112. The motor vehicle circuit breaker 1 can, for example, be arranged along a flat conductor that encompasses the two connecting lugs 102, 104.

[0103] Fig. 6 illustrates an exemplary design of the subject

[0104] Motor vehicle circuit breaker 1, which in a plan view in the direction of

[0105] Surface normal to the broad side of the terminal tab 102. The magnet 122 lies within the broad side of the terminal tab 102 and within the surface of the connector 108. In the configuration shown, the magnet also lies within the contact surface 120 between the terminal tab 102 and the connector 108.

[0106] Reference symbol

[0107] 1 vehicle isolating switch

[0108] 102 first connection tab

[0109] 104 second connection tab

[0110] 106 connecting element

[0111] 108 connecting piece

[0112] 108a Magnetic layer, magnetic part

[0113] 108b Conductive layer

[0114] 110 spring element

[0115] 112 housings

[0116] 114 Insulator

[0117] 120 contact surfaces

[0118] 122 magnets

[0119] 130 Magnetic element comprising 106, 122 and optionally 114

Claims

P a t e n t a n s p r ü c h e 1. Motor vehicle circuit breaker (1) comprising: a first terminal lug (102), a second terminal lug (104), wherein the terminal lugs (102, 104) are spaced apart from one another by a gap, a connecting piece (108) electrically connecting the first terminal lug (102) and the second terminal lug (104) in a closed position, wherein the connecting piece (108) is arranged on a first side of the terminal lugs (102, 104), a spring element (110), wherein the spring element (110) exerts a spring force on the connecting piece (108), wherein the spring force is directed in the direction of a displacement direction of the connecting piece (108) from the closed position to an open position, wherein in the open position the first terminal lug (102) and the second terminal lug (104) are electrically insulated from one another, a arranged on a second side of the terminal lugs (102, 104) opposite the first side Magnetic element (130),wherein the magnetic element (130) exerts a holding force on the connecting piece (108), wherein the holding force acts counter to the direction of displacement, characterized in that up to a first limit temperature of the connecting piece (108) at least one magnetic part (108a) of the connecting piece (108) is ferromagnetic and from a second limit temperature at least the magnetic part (108a) of the connecting piece (108) is not ferromagnetic and the spring element (110) and the magnetic element (130) are arranged such that the holding force is greater in magnitude than the spring force, as long as at least the magnetic part (108a) of the connecting piece (108) is ferromagnetic and the, Holding force is smaller in magnitude than the spring force as soon as at least the magnetic part (108a) of the connecting piece (108) is not ferromagnetic.

2. Motor vehicle circuit breaker (1) according to one of the preceding claims, characterized in that the first limit temperature is less than or equal to the second limit temperature, the first and / or second limit temperature is a Curie temperature and / or depends on a Curie temperature, in particular on a Curie temperature of at least parts of the connecting piece (108), in particular a Curie temperature of the magnetic part (108a) of the connecting piece (108), and / or the first and / or second limit temperature depends on a material composition of the connecting piece (108), in particular of the magnetic part (108a) of the connecting piece (108).

3. Motor vehicle circuit breaker (1) according to one of the preceding claims, characterized in that the holding force is greater than the spring force by a factor of at least 1.5, 2, 2.5, 3, 4, 5, 10, 15, 20, 30, 40, or 50, as long as at least the magnetic part (108a) of the connecting piece (108) is ferromagnetic, in particular in the direction of displacement, in particular in the closed position and / or the open position and / or the spring force is greater than the holding force by a factor of at least 1.5, 2, 2.5, 3, 4, 5, 10, 15, 20, 30, 40, or 50, as long as at least the magnetic part (108a) of the connecting piece (108) is not ferromagnetic, in particular in the direction of displacement, in particular in the closed position and / or the open position Position.

4. Motor vehicle circuit breaker (1) according to one of the preceding claims, characterized in that the connecting piece (108) comprises a ferrite, in particular the magnetic part (108a).

5. Motor vehicle circuit breaker (1) according to one of the preceding claims, characterized in that the first and / or the second connection lug (102, 104) is at least partially housed by a housing (112), in particular in the region of the gap and / or that the housing (112) is mechanically reinforced, in particular with a reinforcement, in particular comprising at least one metal strut and / or that the housing is thermally insulating and / or the housing is at least partially thermally conductive.

6. Motor vehicle isolating switch (1) according to one of the preceding claims, characterized in that the connecting piece (108) is arranged in the direction of gravity in front of or behind at least one of the connecting lugs or both connecting lugs (102, 104).

7. Motor vehicle circuit breaker (1) according to one of the preceding claims, characterized in that the spring element (110) comprises a spring, in particular a tension spring, spiral spring and / or compression spring, in particular a spring made of a metal material and / or plastic, in particular a high-temperature plastic and / or the spring element comprises a bracket and / or the spring element comprises a rubber element.

8. Motor vehicle circuit breaker (1) according to one of the preceding claims, characterized in that the magnetic element (130) has a magnet (122), preferably a permanent magnet and / or an electromagnet and / or the magnetic element (130) is fixed to at least one of the two connecting lugs (102, 104), in particular in a force-fitting, form-fitting and / or material-fitting manner, in particular indirectly via at least one further element, for example an insulator, or directly.

9. Motor vehicle circuit breaker (1) according to one of the preceding claims, characterized in that the displacement direction is oriented substantially perpendicular or substantially parallel to at least one contact surface (120) between the connecting piece (108) and at least one of the connecting lugs (102, 104).

10. Motor vehicle circuit breaker (1) according to one of the preceding claims, characterized in that the direction of displacement is oriented substantially perpendicular to the direction of gravity.

11. Motor vehicle circuit breaker (1) according to one of the preceding claims, characterized in that the connecting piece (108) is movably mounted on at least one of the connecting lugs (102, 104), in particular on a guide, in particular on at least one rail, at least one hinge and / or at least one joint.

12. Motor vehicle circuit breaker (1) according to one of the preceding claims, characterized in that the connecting piece (108) has a minimum cross-section which is smaller than a conductor cross-section of at least one of the connecting lugs (102, 104).

13. Motor vehicle isolating switch (1) according to one of the preceding claims, characterized in that the connecting piece (108) in the open position or the closed position interacts with an electrical and / or electronic component, in particular opens or closes a switch, opens or closes a button, activates or deactivates a touch sensor, activates or deactivates a proximity sensor and / or activates or deactivates a photodetector.

14. Motor vehicle isolating switch (1) according to one of the preceding claims, characterized in that the motor vehicle isolating switch (1) is free from its own power supply.

15. Motor vehicle with a motor vehicle circuit breaker (1) according to one of the preceding claims.

Images