Circuit breaker

Abstract

The invention relates to a circuit breaker (12) which has a busbar (36) to which a fixed contact (42) is attached, and a contact bridge (46) which is mounted movably relative thereto and to which a moving contact (48) is attached. The circuit breaker (12) also comprises an electric drive (84) by means of which the contact bridge (46) is driven, a yoke (124) placed around the busbar (36), and a movably mounted slider (102) to which an armature (120) is attached. The circuit breaker (12) is configured such that, when a first limit value is exceeded by an electric current conducted via the busbar (36), the slider (102) is moved on account of a magnetic interaction between the armature (120) and the yoke (124) and therefore, by means of the slider (102), a switch element (96) connected electrically in series with the electric drive (84) is actuated.

Description

[0001] Description

[0002] Circuit breaker

[0003] The invention relates to a circuit breaker. The circuit breaker comprises a busbar to which a fixed contact is connected, a contact bridge movably mounted thereto, to which a moving contact is connected, and an electric drive by means of which the contact bridge is driven.

[0004] Motor vehicles are increasingly equipped with an electric motor for propulsion. To power the electric motor, an energy storage device is usually used, for example in the form of a so-called high-voltage battery. The energy storage device provides a comparatively high direct voltage, for example greater than 500 V, which feeds an on-board electrical system to which the electric motor is electrically connected. The electrical currents flowing between the on-board electrical system and the energy storage device can amount to several hundred A, particularly if the motor vehicle is comparatively heavy, as is the case with a commercial vehicle. In the event of an emergency, such as an accident, a malfunction of the electric motor and / or a short circuit in the on-board electrical system, it is therefore necessary to disconnect the energy storage device from the on-board electrical system as quickly as possible to avoid injury to helpers or users of the vehicle.The resulting electrical currents, particularly in the case of an overcurrent / short-circuit, can also lead to thermal overload of the on-board electrical system and / or the energy storage device. A circuit breaker, for example, can be used to disconnect them.

[0005] Such a circuit breaker usually has a switching element that is connected between the energy storage device and the on-board electrical system. The switching element is controlled by a control unit that is signal-linked to a current sensor. This measures the electrical current flowing through the switching element during operation. If this current is greater than a limit value, the control unit triggers the switching element to open, interrupting the electrical current flow between the energy storage device and the on-board electrical system. Since a semiconductor switch, by its very nature, has a high internal resistance, even when electrically conductive, a relay is usually used as the switching element. This relay comprises a mechanical switch that is controlled by an electric drive. However, due to the mechanical design, the switching time in this case is longer.This, combined with the necessary evaluation of the measured values ​​provided by the current sensor, results in a comparatively long time lag between exceeding the limit value and the actual interruption of the current flow. Due to the comparatively high currents, damage to the vehicle's electrical system or other components is still possible.

[0006] The invention is based on the object of specifying a particularly suitable circuit breaker, wherein operational reliability is advantageously increased.

[0007] According to the invention, this object is achieved by the features of claim 1. Advantageous further developments and refinements are the subject of the subclaims.

[0008] The circuit breaker serves, for example, to protect a device, and the circuit breaker is, for example, a device circuit breaker. Alternatively or in combination with this, the circuit breaker serves to protect a line and is therefore a line circuit breaker. Alternatively or in combination with this, the circuit breaker is, for example, a battery circuit breaker and is expediently used to protect a battery. Particularly preferably, the circuit breaker, in the assembled state, is part of a motor vehicle, which is, for example, a ship or boat. Preferably, however, the motor vehicle is land-based and, for example, a locomotive. Particularly preferably, however, the motor vehicle is not rail-guided and is, for example, a passenger car (car) or, expediently, a commercial vehicle, such as, in particular, a bus or a lorry (truck).Alternatively, the motor vehicle is, for example, an agricultural machine or a construction vehicle. In the assembled state, the circuit breaker is arranged, in particular, between an energy storage device of the motor vehicle and an on-board electrical system of the motor vehicle, with the energy storage device and the on-board electrical system at least partially forming an electrical circuit. Regardless of the application, the circuit breaker is preferably suitable, in particular intended and configured, for insertion into an electrical circuit and for interrupting the flow of current therein in the event of a fault.

[0009] The circuit breaker comprises, in particular, two terminals, between which a current path is formed and to which, in the assembled state, further components of the circuit are connected. The terminals are suitable, in particular provided and configured, for this purpose. A cable or busbar is expediently connected to the respective terminal for this purpose, with a cross-section of the latter being, for example, between 80 mm2 and 100 mm2. The circuit breaker is suitably provided and configured to switch an electrical voltage, which is, in particular, a direct voltage. The circuit breaker is preferably provided and configured to switch an electrical (nominal or maximum) voltage of more than 200 V. In particular, the electrical voltage is less than or equal to 1,000 V or 1,500 V. The magnitude of the electrical (nominal or maximum) current that can be switched by means of the circuit breaker is suitably greater than 50 A, 100 A, or 200 A.In particular, the electrical current is less than 20,000 A, 10,000 A, or 5,000 A. In particular, the switching capacity of the circuit breaker is one of these values. In particular, the circuit breaker has two different states, namely an electrically conductive (closed) and an electrically non-conductive (open) state. In particular, in the assembled state, the electrical current is conducted between the two terminals when the circuit breaker is in the electrically conductive state. In the electrically non-conductive state, however, the electrical current is interrupted, and in particular, the electrical voltage is present at the terminals.

[0010] The circuit breaker has a busbar to which a fixed contact is connected. The busbar is formed in particular by means of a metal part, such as a metal strip, which is preferably made of aluminum or copper. In particular, the busbar is electrically contacted, in particular rigidly, with one of the possible connections. Suitably, the connection and the fixed contact are assigned to opposite ends of the busbar. The fixed contact is made, for example, of the same material as the busbar and, for example, is flush with it. In other words, the fixed contact is formed in particular by means of a component of the same metal part. Alternatively, the fixed contact is made of a different material in which arc resistance is expediently increased and / or contact resistance / transition resistance is reduced.Preferably, the fixed contact protrudes above the busbar and is thus raised.

[0011] The circuit breaker further comprises a contact bridge that is movably mounted relative to the busbar, and thus also to the fixed contact. A moving contact is connected to the contact bridge. The contact bridge is expediently also formed by a metal part and consists, for example, of the same metal as the busbar, or at least of aluminum or copper. This reduces the number of different materials. In particular, the busbar and the contact bridge are made of the same semi-finished product, which reduces costs. The moving contact is suitably rigidly attached to the contact bridge and, for example, flush with it. However, it is particularly preferred for the moving contact to project beyond the contact bridge and thus be raised.The moving contact is made, for example, from the same material as the contact bridge or preferably from a different material which, in particular, increases resistance to arcing. The circuit breaker suitably has a bearing which, in particular, comprises a bearing by means of which the contact bridge is correspondingly mounted. The contact bridge is expediently mounted in such a way that it is possible to mechanically place the moving contact directly against the fixed contact and also to space it apart from it. When the moving contact is in contact with the fixed contact, an electrical current can flow between the busbar and the contact bridge via the fixed contact and the moving contact. When this is the case, the circuit breaker is, in particular, in an electrically conductive state. It is also possible to space the fixed contact from the moving contact, in particular by means of the bearing, so that they are not mechanically in contact with one another.In this case, the minimum achievable distance is, for example, greater than 2 mm, 3 mm, 5 mm, or 1 cm. If the moving contact is spaced apart from the fixed contact, the contact bridge, in particular, is galvanically isolated from the busbar.

[0012] The contact bridge is suitably electrically connected to any other terminal, for example, directly or via additional components. The busbar, the contact bridge, the moving contact, and the fixed contact are preferably components of any current path formed between the two terminals. When the moving contact is in contact with the fixed contact, the circuit breaker is expediently in the electrically conductive state. When the moving contact is spaced apart from the fixed contact, the circuit breaker is, in particular, in the electrically non-conductive state.

[0013] The circuit breaker further comprises an electrical drive by means of which the contact bridge is driven. In particular, when the electrical drive is operating and / or when the operation of the electrical drive changes, the contact bridge is moved. The electrical drive expediently has a drive coil, which is an electrical coil. Arranged within this coil is a movably mounted coil armature, which is in particular a permanent magnet or at least made of a magnetic material, such as a ferromagnetic or ferrimagnetic. The coil armature is connected to the contact bridge, preferably by means of a coupling rod. When the drive coil is energized, this generates a magnetic field, such that the coil armature moves and, consequently, the contact bridge connected to the coil armature.

[0014] For example, the electric drive, in particular, is designed to be bistable, and the position of the contact bridge is changed, particularly when the electric drive is energized once. If the position is in the desired position, where the moving contact is spaced from the fixed contact or in contact with it, the contact bridge remains in this position, even if the energization of the electric drive is discontinued. Changing the position of the contact bridge requires a new, appropriately adjusted energization of the electric drive.

[0015] However, it is particularly preferred that the electric drive be configured to be merely monostable. In this case, the contact bridge is held in one of the two positions, in particular by operation of the electric drive. When operation, in particular the energization, of the electric drive is terminated, the contact bridge is moved to the other position. For this purpose, the contact bridge is expediently additionally subjected to a further force, which is provided in particular by a spring of the electric drive. By means of this force, the contact bridge is transferred, in particular, to the stable position, whereas during operation of the electric drive, a greater, opposing force is applied to it.In particular, the electric drive or at least the circuit breaker is designed in such a way that, when the electric drive is not in operation, the fixed contact is / will be spaced apart from the moving contact, which increases safety.

[0016] The circuit breaker further comprises a yoke that is placed around the busbar. The yoke at least partially surrounds the busbar and is preferably spaced apart from it. Suitably, the yoke is galvanically isolated from the busbar so that they can, in particular, have different electrical potentials. Preferably, the yoke is substantially ring-, O-, or U-shaped and expediently has a recess so that the yoke is not completely closed. Preferably, the yoke does not completely surround the busbar. The yoke is made in particular from a magnetic material, in particular a soft magnetic material, such as a ferro- or ferrmagnetic material. In particular, however, the yoke itself is not a permanent magnet. Suitably, the yoke is made from soft iron or transformer sheet.In particular, the yoke is designed and arranged in such a way that a magnetic field is induced therein when an electric current is conducted across the busbar. At least a magnetic field surrounding the busbar, which results from an electric current flowing through the busbar, is expediently concentrated by the yoke. In this case, an air gap is present, in particular, due to the recess.

[0017] The circuit breaker further comprises a slide which is movably mounted. The slide is expediently designed to be electrically non-conductive and / or non-magnetic. In particular, the slide is made from a paramagnetic or diamagnetic material and expediently from a plastic. This reduces manufacturing costs. An armature, which is, for example, a permanent magnet or made from a soft magnetic material, is attached to the slide. In other words, the armature is made from a ferrimagnetic or ferromagnetic material, such as ferrite. Alternatively, the armature is made from steel, for example. In particular, the armature is attached to the slide. For example, they are glued together, or the slide has a pocket within which the armature is arranged. In one alternative, the slide comprises, for example, locking elements by means of which the armature is secured.At least when the slider is moved, the armature is also moved, preferably in the same direction and by the same amount, and conveniently also vice versa.

[0018] The circuit breaker is designed such that when a first limit value is exceeded by the electrical current conducted via the busbar, which is equal to the current conducted by means of the circuit breaker or at least the current path, the slide is moved due to a magnetic interaction between the armature and the yoke. In other words, the yoke in particular is arranged such that the electrical current conducted via the busbar induces or at least causes a magnetic field in the yoke that interacts with the armature, expediently by means of a magnetic field provided by the armature. For this purpose, the armature is magnetized and / or positioned accordingly so that a magnetic field is also induced there. Alternatively or in combination with this, magnetic field lines are bundled by means of the armature, which are provided in particular by the yoke.The slide is only moved when the electrical current exceeds the first limit value, at least to the extent that this is the case once the first limit value has been exceeded. If the electrical current is below the first limit value, the magnetic interaction, i.e. in particular the magnetic force acting between the yoke and the armature, is not sufficient to move the slide. The circuit breaker is designed accordingly for this purpose. For example, the friction of the slider's bearing is too great and / or there is another mechanism that includes a spring, for example. In other words, the slide is expediently spring-loaded. Alternatively or in combination with this, the yoke is designed, for example, in such a way that only a comparatively small number of magnetic field lines are bundled by it, provided the electrical current remains below the first limit value.

[0019] It is advisable for the armature and the yoke, in particular any recess, to be adapted accordingly.

[0020] If the slide is moved due to the magnetic interaction when the first limit value is exceeded, a switching element which is electrically connected in series with the electric drive is actuated by means of this. Due to the actuation of the switching element, the current supply to the electric drive is changed. In this case, for example, current supply to the electric drive is started or, particularly preferably, interrupted. Due to the changed current supply to the electric drive, at least the position of the contact bridge is changed and the circuit breaker is thus transferred to a different state, in particular to the electrically non-conductive state. The circuit breaker is adapted accordingly for this purpose. Advantageously, at least when the switching element is not actuated by means of the slide, the armature is spaced apart from the yoke or at least from any recess.In contrast, when the switching element is actuated, or at least when the slide moves toward the switching element to actuate it, the distance between the armature and the yoke, in particular to any recess, is reduced. The slide is suitably mounted accordingly for this purpose.

[0021] In summary, it is therefore preferable that when the first limit value is exceeded by the conducted electrical current, the circuit breaker be placed in an electrically non-conductive state. This makes it possible to design the slide and the armature connected to it comparatively lightly. In particular, the mass of the slide to be moved is less than, for example, the mass of the contact bridge. Thus, when the first limit value is exceeded, the magnetic forces then prevailing and the low mass of the slide cause the latter to move comparatively quickly. Thus, the switching element is actuated comparatively quickly after the first limit value is exceeded, and thus, in particular, the flowing electrical current is interrupted.

[0022] Furthermore, essentially no processing of measurement data relating to the electrical current or the like is required, which also shortens the time until the current supply to the electric drive is changed. Furthermore, the number of required electrical / electronic components is reduced, which reduces manufacturing costs and reduces the susceptibility to errors. Furthermore, since the slider, yoke, and armature are preferably galvanically isolated from the busbar, special insulation is not required, which simplifies the design. Furthermore, artifacts in the conducted electrical current do not impair the function of the slider, thus increasing robustness.Due to the shortened switching time and the robust design, it is therefore always ensured that the electric drive is actuated, i.e. operated in a modified manner, when the first limit value is exceeded, which increases operational reliability. For example, the electric drive is electrically connected to the busbar and / or the contact bridge, so that the electric drive is supplied with current via the circuit that is protected by the circuit breaker. In other words, in particular the electrical current conducted via the busbar is also used to operate the electric drive, and these are expediently interconnected accordingly. However, the circuit breaker particularly preferably has a further connection for connecting a secondary circuit, by means of which the electric drive is supplied with current.In particular, a reduced electrical voltage is provided by the secondary circuit, which is particularly between 5 V and 30 V and in particular equal to 12 V, 24 V, or 48 V. This reduces the safety / insulation requirements of the electric drive. Comparatively low-performance and / or cost-effective components can also be used. Furthermore, this ensures that the electric drive will still operate correctly in the event of a malfunction in the circuit protected by the circuit breaker.

[0023] Alternatively or in combination therewith, the circuit breaker expediently comprises an arcing chamber with an arcing element. In this case, the arcing element is arranged substantially adjacent to the fixed contact and / or the moving contact, and these are expediently located in the arcing chamber, which in particular comprises a further magnetic yoke. For example, the arcing chamber has a driving element, in particular a permanent magnet. If the moving contact is spaced apart from the fixed contact, it is possible for an arc to form between them. The arcing chamber is designed such that the arc is driven into the arcing element, preferably by means of the driving element, if any, and / or the further magnetic yoke. By means of the extinguishing element, which for example comprises a stack of arc splitters, the arc is in particular cooled and / or elongated.At the very least, the arc-quenching element is designed in such a way that the electrical voltage required to maintain the arc is increased, in particular above the electrical voltage present between any terminals. As a result, the arc collapses, and the current flow through the circuit breaker is interrupted, even if the arc initially formed between the fixed contact and the moving contact, which initially caused a current flow through the circuit breaker to continue.

[0024] The circuit breaker suitably comprises a housing within which all other components of the circuit breaker are expediently arranged. This ensures contact safety and facilitates assembly / use. The housing is made in particular from a plastic. Preferably, the terminals are incorporated into the housing, enabling electrical contact between the components of the circuit breaker arranged in the housing and through the housing. Preferably, the busbar is rigidly connected to the housing, for example, fastened or held there by means of an at least partially positive-locking system. This facilitates design and manufacture.

[0025] In particular, the electric drive comprises a spring that is advantageously tensioned when the moving contact is in contact with the fixed contact. By applying current to the electric drive, a force applied by the spring is advantageously overcompensated. When the current to the electric drive is removed, essentially only the spring force acts, which advantageously leads to a separation of the moving contact from the fixed contact.

[0026] For example, actuating the switching element operates the electric drive, so that it is energized. However, actuating the switching element by means of the slider particularly preferably interrupts the supply of current to the electric drive. As a result, the circuit breaker is placed in an electrically non-conductive state, preferably by means of the spring, if any. This increases safety.

[0027] For example, the contact bridge is rigidly attached to the electrical drive, in particular to any coupling rod. However, the contact bridge is particularly preferably held on a contact bridge carrier and supported relative to it by a spring. The contact bridge carrier is preferably made of plastic. When the electrical drive is operated, the contact bridge carrier and consequently the contact bridge are moved. When the circuit breaker is switched to the electrically conductive state, the contact bridge carrier with the contact bridge held thereon is moved until the moving contact is in mechanical contact with the fixed contact. Subsequently, further movement of the contact bridge is inhibited, and due to further operation of the electrical drive, the contact bridge carrier is moved further and the spring present between the contact bridge and the contact bridge carrier is compressed.This ensures that the moving contact rests firmly against the fixed contact. This ensures that even if the circuit breaker vibrates, the mechanical contact between them is not interrupted, and manufacturing tolerances are compensated for. When the circuit breaker is opened, i.e., when it is switched to the electrically non-conductive state, the electric drive first moves the contact bridge carrier, thereby releasing the spring. Only when the spring is completely released, or, for example, when the contact bridge strikes a stop on the contact bridge carrier, is the spring also moved, thus separating the moving contact from the fixed contact.

[0028] In particular, the yoke and the armature are designed in such a way that a comparatively high force acts on the slide essentially immediately after the first limit value is exceeded. In particular, this force is greater than in the position of the slide in which the switching element is actuated. At least the maximum of the acting force is expediently present in a position of the slide which is between the original position of the slide and halfway until the switching element is actuated. Thus, as soon as the first limit value is exceeded, a comparatively high acceleration of the slide occurs, so that the time period until the switching element is actuated is shortened. The force exerted on the switching element by the slide is also reduced, so that it is not damaged.In summary, the circuit breaker is designed in particular such that, at least before the switching element is actuated, a maximum of the magnetic force acting between the yoke and the armature is reached, wherein the magnitude of the force is particularly dependent on the position of the slide.

[0029] In particular, the slide or at least the circuit breaker is designed such that, as long as the electrical current is greater than the first limit value, the switching element remains actuated. For example, the circuit breaker is designed such that the slide initially remains in the position in which the switching element is actuated. Alternatively, a reset mechanism is provided, which in particular comprises a spring, and the slide is preferably spring-loaded by means of the spring. By means of the reset mechanism, the slide is returned to its original position after actuation of the switching element. Thus, the slide is always in the same position, and the circuit breaker always exhibits the same behavior.

[0030] The first limit value corresponds in particular to a multiple of the rated current of the circuit breaker, so that the corresponding actuation of the switching element only occurs in the event of a malfunction of the circuit protected by the circuit breaker. In particular, the first limit value is between three and four times the rated current. Thus, in particular in the event of an overcurrent, a corresponding change in the current supply to the electric drive occurs. In contrast, in the case of comparatively small fluctuations around the rated current, the slide is not moved, or at least the switching element is not actuated. The first limit value is in particular greater than 500 A and suitably less than 1,000 A. In particular, the first limit value is 650 A, 700 A, 750 A or 800 A.

[0031] For example, the busbar is essentially straight, which facilitates manufacturing. However, the busbar is particularly preferably essentially L- or C-shaped, with the fixed contact being connected to one leg, by means of which a free end is formed. The fixed contact is expediently located on the outward-facing side of the leg, i.e., not on the side facing the other leg. The leg of the busbar to which the fixed contact is connected is expediently parallel to the contact bridge, which is expediently designed to be straight. Such a configuration simplifies construction.

[0032] For example, the switching element is a semiconductor switch or a relay. Particularly preferably, the switching element is a mechanical switching contact, for example a microswitch. As a result, on the one hand, space requirements and manufacturing costs are reduced. On the other hand, the mechanical switching contact is comparatively resistant to an arc formed therein when the mechanical switching contact is actuated, in particular opened. This enables reliable actuation of the switching element and, consequently, corresponding operation of the electric drive. Actuation is also facilitated in this way. For example, the mechanical switching contact comprises a lever, which is spring-loaded, for example, and on which the slide acts. In particular, when the mechanical switching contact is actuated by means of the switching element, the current supply to the electric drive is ended / interrupted.Due to any arc forming in the mechanical switching contact, any inductance of the electrical drive, in particular any drive coil, is de-energized comparatively quickly, so that essentially no more force is exerted on the contact bridge by the electrical drive, at least none that would hold the moving contact to the fixed contact. In summary, the electrical drive is de-energized, in particular, via the mechanical switching contact, namely by means of any arc formed therein.

[0033] For example, the switching element is designed to be bistable, so that after actuation using the slide it remains in this (switching) state. Only when a further corresponding actuation occurs is the switching element returned to its original state, expediently closed. Alternatively, the switching element is designed to be monostable, for example. For example, the mechanical switching contact is monostable open. However, it is particularly preferred that the mechanical switching contact is monostable closed. Thus, unless actuation using the slide occurs, the mechanical switching contact is in the electrically conductive state. If the actuation of the switching element using the slide is therefore ended, the switching element is returned to the electrically conductive state. The reset mechanism for the slide is expediently present.Thus, after the switching element has been actuated by means of the slider, both the slider and the switching element are returned to their original state, for example due to a respective spring load.

[0034] Due to the actuation of the switching element and the corresponding change in the current supply to the electrical drive, in particular the termination of the current supply, the contact bridge is preferably moved such that the moving contact is spaced apart from the fixed contact. Expediently, the switching element and the slide are then also returned to their original state. For example, the electrical drive is then supplied with current again, and the contact bridge is moved such that the moving contact is once again in contact with the fixed contact. This makes it possible for an electrical current to form again via the busbar. If this current rises above the first limit value again, the switching element is actuated again by means of the slide. If the electrical current remains below the first limit value, however, the circuit breaker remains in the electrically conductive state.In an alternative embodiment, it is particularly possible to operate the electric drive differently, for which purpose in particular a different electrical voltage is applied to it.

[0035] For example, the circuit breaker is designed without any control unit and thus without a control unit. In other words, the circuit breaker is expediently designed electromechanically and, in particular, does not have a microcontroller and / or electronics. This increases robustness while reducing manufacturing costs. The circuit breaker expediently has an auxiliary connection via which current is supplied to the electric drive. Thus, it is possible to put the circuit breaker into the electrically conductive state by applying an electrical voltage to the auxiliary connection. The auxiliary connection expediently offers the possibility of applying two different electrical voltages to the electric drive.When using one electrical voltage, for example, the resulting current is only sufficient to compensate for the force provided by any springs, so that it is only possible to leave the circuit breaker in its current (switching) state. In contrast, using the other electrical voltage causes the spring to compress, so that the circuit breaker is placed in the electrically conductive state.

[0036] Alternatively, the circuit breaker has a control unit. This actuates a second switching element, and the second switching element and the control unit are suitably interconnected for this purpose. The second switching element is, for example, a relay or, particularly preferably, a semiconductor switch. The second switching element is electrically connected in series with the switching element. It is possible, for example, for the electric drive to be arranged between the two switching elements, or for one of the two switching elements to be arranged between the other switching element and the electric drive.

[0037] The control unit is designed in such a way that the second switching element is actuated by means of it when the electrical current conducted via the busbar exceeds a second limit value. The circuit breaker expediently comprises a sensor by means of which the electrical current conducted via the busbar can be detected. The sensor is in particular a current sensor, which for example comprises a Hall sensor. Alternatively, the sensor comprises a shunt. The control unit is, for example, discretely constructed, in particular from electrical components such as capacitors, inductors and / or resistors. Alternatively, the control unit comprises, for example, an electronic component, in particular a microcontroller. In this way, in particular, adaptability of the circuit breaker to current conditions is enabled.

[0038] The second limit value is less than or equal to the first limit value, and the mechanical switching contact is designed to be monostable and closed. For example, the second limit value is between 1.5 times and 2.5 times, in particular twice, the rated current. Alternatively, the second limit value is equal to the first limit value. If the electrical current therefore exceeds the second limit value, which is selected to be lower than the first limit value, the control unit actuates the second switching element, thereby changing the current supply to the electrical drive. This is expediently done in such a way that the moving contact is spaced apart from the fixed contact. The slide, on the other hand, remains in its original position.Since an evaluation of the measurement data generated by the sensor is necessary, the time span between the second limit value being exceeded and the change in the current supply to the electric drive is comparatively long. However, since this only occurs when the electric current is slightly increased, damage to the circuit for which the circuit breaker is used to protect is essentially ruled out. However, since there is no comparatively high acceleration of the slide, mechanical stress on the circuit breaker is reduced. If, on the other hand, the electric current increases comparatively quickly and exceeds the first limit value before the second switching element is actuated, the switching element is actuated by means of the slide, which in particular interrupts the current supply to the electric drive.Subsequently, the control unit actuates the second switching element, by means of which, in particular, no electrical current is then carried out any longer, so that switching takes place essentially without a load.

[0039] Since the switching element is actuated relatively quickly by the slider in the event of an increased electrical current flow, which can lead to a hazard if it persists for a longer period of time, namely when the first limit value is exceeded, it is possible to use a second switching element with a reduced switching speed. This reduces manufacturing costs without compromising safety.

[0040] The switching element is expediently designed to be monostable and closed, and the return mechanism for the slide is present, so that after actuation of the switching element, the slide is returned to its original position, which leads to the closing of the switching element. However, since the second switching element was opened by the control unit, there is no change in the current supply to the electric drive. Thus, the contact bridge is nevertheless held / moved in the position where the fixed contact is spaced from the moving contact. If the second limit value is selected to be equal to the first limit value, the circuit breaker also remains in the open state when this limit value is exceeded.

[0041] Preferably, one or more additional sensors are present, depending on their measurement data or detected states, the second switching element is actuated by the control unit. For example, if high-frequency interference occurs in the electrical current and / or if the applied electrical voltage changes, the second switching element is actuated, so that, in particular, the current supply to the circuit into which the circuit breaker is incorporated is interrupted.

[0042] The slide is expediently spring-loaded, for which purpose a spring is supported on it in particular. The spring is expediently a component of any return mechanism. The spring is compressed in particular when the slide is moved to actuate the switching element. The spring is designed in particular as a helical spring. Alternatively, the return mechanism is implemented in particular by means of the switching element itself, which is designed in particular to be monostable. The force applied to the slide by the switching element is then expediently at least partially compensated by means of the spring. The spring thus reduces the mechanical force that must be applied by the slide to the switching element in order to actuate it.

[0043] For example, the force applied by the spring is fixed. However, it is particularly preferred that the acting force is adjusted using an adjusting screw, also known as an adjusting screw. In this case, the acting force is expediently functionally related to the first limit value, so that the first limit value is adjusted using the adjusting screw. To reduce the first limit value, the acting force is reduced if the spring is compressed towards the switching element when the slide is moved. Otherwise, the force is increased. The adjusting screw therefore makes it possible to adjust and / or calibrate the circuit breaker for the desired application after production. It is also possible to do this while the circuit breaker is still in its assembled state and / or to compensate for any aging effects.In particular, no other modifications to the mechanics and / or electronics of the circuit breaker are required. Ideally, the adjustment screw protrudes through the housing, if present, and / or the housing has an opening through which the adjustment screw can be accessed. This allows the first limit value to be set without opening the housing.

[0044] For example, it is possible for the switching element to be moved essentially freely after it has been actuated by the slide. The circuit breaker expediently comprises the reset mechanism so that after the switching element has been actuated, the slide is returned to its original position. However, the circuit breaker particularly preferably has a reclosing lock which has a first locking element provided by the slide and a second locking element that is fixed with respect to the switching element. In other words, the first locking element is in particular a component of the slide, whereas the second locking element is held stationary with respect to the switching element and is provided, for example, by means of the housing. In particular, at least one of the two locking elements is designed as an undercut and the other as a spring.Alternatively or in combination with this, one of the locking elements is designed as a locking hook and the other as a locking lug.

[0045] The reclosing lock is designed in such a way that after a movement of the slide due to an electric current conducted via the busbar which is greater than a third limit value, the two locking elements are locked. In this case, the movement occurs in particular due to the magnetic interaction between the armature and the yoke. In this case, for example, the movement has already been completed, so that actuation takes place first and then rusting occurs. Alternatively, the slide is moved further due to the magnetic interaction after rusting, so that locking occurs before the switching element is actuated. In this case, the rusting is in particular such that further movement of the slide in the direction of the switching element is possible, so that the switching element can be actuated. However, a complete return of the slide to its original position is prevented.Conveniently, if the two locking elements become rusted, the switching element is actuated by means of the slide. This way, the switching element is held in the actuated position by the reclosing lock.

[0046] For example, the third limit value is equal to the first limit value, so that the reclosing lock is activated essentially every time the switching element is actuated by means of the slide. However, the third limit value is particularly preferably greater than the first limit value and corresponds, for example, to between eight and ten times the rated current of the circuit breaker. Thus, the reclosing lock is only activated in the event of a serious circuit fault. The reclosing lock reliably prevents the circuit breaker from being accidentally switched into the conductive state. The third limit value is preferably between 1,500 A and 2,000 A.

[0047] In particular, the reclosing lock is designed in such a way that it can only be deactivated when the housing is open. This requires, in particular, the circuit breaker to be replaced or removed first. This ensures that a user only uses the faulty circuit again after troubleshooting. The open housing also allows for checking whether the circuit breaker has been damaged due to the increased electrical current.

[0048] The yoke preferably has the recess. In this case, the yoke is U-shaped, for example, and by means of this, the busbar is partially encompassed. For example, when the slide is moved, the armature comes into direct mechanical contact with the yoke. Preferably, however, the armature remains spaced from the yoke essentially in every position of the slide. The shape of the armature expediently corresponds to the shape of the recess. In particular, these are congruent or at least have the same geometric shape. In this case, the armature and the recess are, for example, rectangular. However, the recess and the armature are particularly preferably wedge-shaped or triangular, with their sizes corresponding in particular to one another. Expediently, the yoke has the size of the recess.Due to the wedge shape, it is possible to adjust the magnetic interaction, especially the force acting between the armature and the yoke, relatively precisely. In particular, it is possible to influence the reluctance and thus the magnitude of the acting force. Consequently, it is possible to select the speed at which the slide is moved by the applied electric current after the first limit value is exceeded.

[0049] For example, the contact bridge is mounted in a rotational manner so that it is rotated to space the moving contact from the fixed contact. However, the contact bridge is particularly preferably mounted in a longitudinally displaceable manner. This simplifies construction. In particular, the bearing used for this purpose comprises a plain bearing. For example, the slide is mounted in a rotational manner. However, it is particularly preferably mounted in a longitudinally displaceable manner, which simplifies bearing construction. For example, the slide is mounted essentially perpendicular to the contact bridge, which is also longitudinally displaceable. This enables, in particular, comparatively efficient use of the installation space. The slide is expediently designed such that it is moved between the moving contact and the fixed contact, for example after the switching element has been actuated.The slider thus ensures the mechanical separation of the two contacts, and if an arc is present between them, the slider increases the electrical voltage required to maintain it. In addition, subsequent electrical flashover between the moving contact and the fixed contact is prevented. This improves its insulating effect. Alternatively, or in combination with this, the slider serves as a reclosing lock, and in particular to prevent the moving contact from accidentally coming into contact with the fixed contact. However, it is particularly preferred that the contact bridge and the slider are mounted parallel to one another. This makes it possible, in particular, to coordinate their two bearings and, for example, to use part of the contact bridge bearing for the slider bearing, which increases compactness and, in particular, reduces manufacturing costs.Particularly preferably, the bearing arrangement is such that, upon movement of the slider due to an electric current conducted via the busbar that exceeds a fourth limit value, the slider mechanically strikes a coupling rod connected to the contact bridge. This movement occurs, in particular, due to the magnetic interaction between the armature and the yoke. For example, the slider strikes the coupling rod indirectly or, expediently, directly. The contact bridge is, for example, attached directly to the coupling rod, or, expediently, any contact bridge support is rigidly attached to the coupling rod.

[0050] Due to the impact on the coupling rod, a force is exerted on the contact bridge which is directed away from the fixed contact. In particular, the force is parallel to the direction in which the contact bridge is mounted and in which it is moved to distance the moving contact from the fixed contact. In other words, the force is directed in particular parallel to an opening direction of the contact bridge. In other words, in particular by means of the slider, a force is exerted on the contact bridge in such a way that the moving contact is distanced from the fixed contact. Thus, in particular the slider acts like a strike anchor. Due to the slider, the force is therefore additionally exerted on the contact bridge, resulting in an accelerated separation of the moving contact from the fixed contact.In summary, the circuit breaker is designed in such a way that when the electrical current carried is greater than the fourth limit value, the force is exerted on the contact bridge by means of the slide.

[0051] The fourth limit value, for example, is equal to the first limit value or expediently higher. In particular, the fourth limit value is equal to any third limit value and / or between five and ten times the rated current of the circuit breaker. In particular, the fourth limit value is between 2,000 A and 7,000 A, and preferably between 3,000 A and 4,000 A. Thus, the coupling rod is only struck at a comparatively high electrical current, whereas at lower electrical currents, this is not the case, and the contact bridge is expediently moved solely by the electric drive. This reduces the load on the slide.

[0052] For example, the force is applied when the movement of the slide has ended, or the movement is ended by means of the application. For example, the force is applied at the same time as the switching element is actuated. The circuit breaker is expediently designed accordingly for this purpose. However, it is particularly preferred if the contact bridge and the slide are mounted parallel to one another and / or the circuit breaker is designed such that the slide only mechanically strikes the coupling rod after the switching element has been actuated. In this way, the actuation of the switching element is not delayed due to the force being exerted on the coupling rod. In other words, the time-delayed impact on the coupling rod ensures that the actuation of the switching element is not delayed, so that the electric drive is actuated comparatively quickly and operated accordingly.The modified operation of the electric drive is supported by impacts on the coupling rod. This also dissipates the kinetic energy of the slide valve without causing damage.

[0053] For example, a stranded wire or other movable / flexible electrically conductive component is connected to the contact bridge and is electrically contacted with any remaining connection. However, the circuit breaker particularly preferably comprises a further busbar to which a further fixed contact is connected. The further busbar is in particular electrically contacted with the remaining connection, so that in particular one of the two busbars is electrically contacted with each of the two connections, expediently rigidly and / or directly. In particular, a further moving contact is connected to the contact bridge. When the contact bridge is moved, in particular the moving contact is moved towards the fixed contact and the further moving contact is moved towards the further fixed contact or is separated from them. When spaced apart, these are expediently separated from one another essentially at the same time.In this way, when the contact bridge is separated, the electrical current flow is doubled, making it possible to switch even comparatively high electrical voltages using the circuit breaker. This doubles the electrical voltage required to maintain an electrical current flow due to arcs that develop.

[0054] In particular, an additional arcing chamber is assigned to the additional fixed contact and the additional moving contact. This is expediently of identical construction to any arcing chamber. The busbars and the contacts are suitably of identical construction so that identical parts can be used. The busbars are expediently arranged mirror-inverted to one another, and the busbar and the additional busbar are C-shaped, allowing comparatively efficient use of the installation space. In particular, the legs carrying the fixed contacts are directed away from one another and are suitably located on a common straight line. The contact bridge is expediently essentially straight, which simplifies construction.

[0055] For example, only the yoke is present. Preferably, however, a further yoke is placed around the further busbar, which is expediently structurally identical to the yoke. A further armature is expediently connected to the slide, which is in particular structurally identical to the armature, which is why identical parts can be used. In this case, the further yoke and the further armature are in particular designed such that the slide is moved due to a magnetic interaction between them. In other words, if the electrical current exceeds the first limit value or another of the possible limit values, the slide is also moved due to the magnetic interaction between the further yoke and the further armatures. Due to the further yoke and the further armature, the force acting on the slide is thus increased, which is why its acceleration is increased.It is also possible to make the two yokes and the two armatures smaller, while still ensuring that the slider moves safely when the respective limit value is exceeded.

[0056] The circuit breaker expediently has a switch unit that includes the busbar, the fixed contact, the contact bridge, and the moving contact. If the additional busbar, the additional fixed contact, and the additional moving contact are present, these are also assigned to the switch unit. In particular, the switch unit includes the two connections, if any, and any current path formed between them. Suitably, the circuit breaker has a second busbar, to which a second fixed contact is connected. The circuit breaker also includes a second contact bridge, to which a second moving contact is connected. Suitably, the second busbar, the second contact bridge, the second fixed contact, and the second moving contact are identical in construction to the busbar, the contact bridge, the fixed contact, and the moving contact, respectively.In particular, the second busbar and the second contact bridge are part of a second switch unit, which is expediently identical in construction to the switch unit.

[0057] The two contact bridges are conveniently connected to the contact bridge carrier, if present, which is preferably made of plastic. The electric drive drives the contact bridge carrier, and via this, the two contact bridges. In other words, the (same) electric drive is assigned to both contact bridges. Thus, the electrical current flow in the two switch units is essentially established or interrupted synchronously.

[0058] Suitably, a second yoke is placed around the second busbar. This is designed / arranged, for example, in such a way that it also has a magnetic interaction with the armature, on the basis of which in particular a corresponding movement of the slide occurs. However, a second armature is particularly preferably connected to the slide, which is expediently structurally identical to the armature. Due to such a design, it is thus possible to interrupt the current flow in two separate circuits simultaneously if the electrical current in one of the circuits is greater than the respective limit value. In summary, if the electrical current carried in one of the two busbars is greater than the (respective) first limit value, the slide is moved, in particular due to the respective magnetic interaction, so that the switching element is actuated.It is also possible, for example, to integrate the circuit breaker into both a forward and return conductor to a load, thus increasing safety. In this case, the required force acting between the respective yoke and the respective armature, which causes the slide to move, is reduced, simplifying the design.

[0059] The circuit breaker is particularly preferably used to interrupt DC voltage and / or DC current. The circuit breaker is expediently used in a motor vehicle or an industrial plant. The invention also relates to the corresponding use of the circuit breaker. The invention also relates to an electrical circuit having such a circuit breaker. The circuit expediently comprises a DC voltage source and a load. In particular, the circuit is a component of a motor vehicle. The DC voltage source is, for example, an energy storage device, such as a high-voltage battery, and the load is, for example, an electric motor or at least a drive comprising the electric motor.

[0060] The further developments and advantages explained in connection with the circuit breaker can also be transferred to the use / circuit as well as to each other and vice versa.

[0061] In the following, exemplary embodiments of the invention are explained in more detail with reference to a drawing. In the drawing: Fig. 1 schematically shows a DC circuit with a circuit breaker having two switch units,

[0062] Fig. 2 perspective view of the circuit breaker,

[0063] Fig. 3 shows the circuit breaker in perspective, with one housing omitted,

[0064] Fig. 4, 5 each show a section of one of the switch units from different perspectives,

[0065] Fig. 6 shows a perspective view of a slider of the circuit breaker,

[0066] Fig. 7 perspective view of the switch unit,

[0067] Fig. 8 - 10 show the circuit breaker in a vertical and horizontal sectional view,

[0068] Fig. 11 shows a sectional view of a section of the circuit breaker with a reclosing lock,

[0069] Fig. 12 shows a perspective view of a further embodiment of the circuit breaker, Fig. 13 shows a perspective view of the circuit breaker according to Fig. 12, with the housing omitted,

[0070] Fig. 14, 15 each show a section of one of the switch units of the circuit breaker according to Fig. 12 from different perspectives,

[0071] Fig. 16 shows in perspective a slide of the circuit breaker according to Fig. 12, and

[0072] Fig. 17, 18 show in perspective and in a rear view one of the switch units of the circuit breaker according to Fig. 12.

[0073] Corresponding parts are provided with the same reference numerals in all figures.

[0074] Figure 1 schematically shows a motor vehicle 2 in the form of a truck. The motor vehicle 2 has an energy storage device 4 with two poles 6. A direct current of 1,000 V is applied between the two poles 6. The energy storage device 64 supplies an on-board electrical system 8 of the motor vehicle 2, which is thus a high-voltage on-board electrical system. Connected to the on-board electrical system 8 is a drive 10 of the motor vehicle 2, which represents the main drive of the motor vehicle 2. In other words, wheels of the motor vehicle 2 (not shown in detail) are driven by the drive 10, so that the motor vehicle 2 moves. For this purpose, the drive 10 has an electric motor (not shown in detail) and a converter.

[0075] To protect the on-board electrical system 8 and the drive 10, a circuit breaker 12 is provided, shown in perspective in Figure 2. The circuit breaker 12 is electrically connected between the energy storage device 4 and the on-board electrical system 8. It is possible to change the switching state of the circuit breaker 12 so that it is either conductive (closed) or electrically non-conductive (open). During normal operation, an electrical current of up to 500 A is conducted through the circuit breaker 12. In other words, the rated current of the circuit breaker 12 is 500 A.

[0076] The circuit breaker 12 has a terminal 14 connected to one pole 6 of the energy storage device 4. A further terminal 16, which, provided the circuit breaker 12 is in the electrically conductive state, has the same electrical potential as terminal 14, is connected to the vehicle electrical system 8. A second terminal 18 of the circuit breaker 12 is also in contact with the vehicle electrical system 8, and a second further terminal 20 is electrically contacted with the remaining pole 6 of the energy storage device 4. The second terminal 18 and the second further terminal 20 also have the same electrical potential, provided the circuit breaker 12 is in the electrically conductive state. The direction of the electrical current between the terminal 14 and the further terminal 16 also corresponds to the direction of the electrical current between the second terminal 18 and the second further terminal 20.The terminals 14, 16, 18, and 20 protrude through a housing 22 made of plastic. The housing 22 is constructed in several parts, which facilitates the manufacture of the circuit breaker 12.

[0077] The remaining components of the circuit breaker 12 are arranged within the housing 22. The circuit breaker 12 comprises a switch unit 24 and a second switch unit 26, which are essentially structurally similar, namely, in particular, mirror-imaged. The switch unit 24 has a housing shell 28 and a further housing shell 30, which are arranged adjacent to one another, as shown in Figure 3. The second switch unit has a second housing shell 32 and a second further housing shell 34, which are constructed and arranged in a mirror-image manner to the housing shells 28, 30 of the switch unit 24. The second further housing shell 34 rests against the further housing shell 30, and the outer sides of the housing shells 28, 30, 32, 34 are arranged flush with one another.

[0078] Figure 4 shows a perspective view of the switch unit 24 from one side and Figure 5 shows it from the opposite side, with the housing shell 28 not being shown. The switch unit 24 has a busbar 36, which is a C-shaped bent copper part. The connection 14 is formed by one of the two parallel legs of the busbar 36. The switch unit 24 has a further busbar 38, which is a mirror image of the busbar 36 and by means of which the further connection 16 is formed. The two inner legs of the C-shaped busbars 36, 38 are arranged parallel to one another and offset from one another. To prevent an electrical short circuit, an insulating plate 40 made of a plastic is arranged between them and is formed parallel to the other legs.

[0079] The legs of the two busbars 36, 38 that have the respective terminals 14, 16 are also arranged parallel to each other, but point away from each other. A fixed contact is connected to the remaining leg of the busbar 36, and another fixed contact 44 is connected to the remaining leg of the other busbar 38. The fixed contacts 42, 44 are located on the side of the respective busbar 36, 38 facing away from the respective terminals 14, 16.

[0080] The switch unit 24 further includes a movably mounted contact bridge 46. The contact bridge 46 can be positioned parallel to the central limbs of the respective C-shaped busbars 36, 38. The contact bridge 46 is a copper strip and is arranged parallel to the end limbs of the busbars 36, 38. A moving contact 48 and another moving contact 50 are connected to the contact bridge 46. The moving contacts 48, 50 are located on the sides of the contact bridge 46 facing the busbars 36, 38.

[0081] The fixed contacts 42, 44 limit the mobility of the contact bridge 46, namely when the moving contact 48 is in contact with the fixed contact 42 and the further moving contact 50 is in contact with the further fixed contact 44. In this position of the contact bridge 46, the two terminals 14, 46 are electrically connected to one another with low resistance. When the contact bridge 46 is moved parallel to the course of the respective middle leg of the two busbars 36, 38, the moving contacts 48, 50 are spaced apart from the associated fixed contacts 42, 44, so that the electrical connection between the two terminals 14, 16 is eliminated. The two terminals 14, 16 are then also galvanically isolated from one another.

[0082] The switch unit 24 further comprises a quenching chamber 52 with a quenching element 54 formed from a plurality of stacked quenching plates. The quenching element 54 is arranged within a magnetic yoke 56 formed by a plurality of soft iron plates, some of which are shown. To direct any arc that may arise between the fixed contact 42 and the moving contact 48, a guide plate 58 is attached to the contact bridge 46 and is inclined relative to the path of the contact bridge 46. A further quenching chamber 60 is assigned to the further fixed contact 44 and the further moving contact 50. This further quenching chamber 60 is structurally identical to the quenching chamber 52 and thus also comprises the quenching element 54, the magnetic yoke 56, and the guide plate 58. The two quenching chambers 52, 60 are arranged on the respective open side of the associated C-shaped busbar 36, 38.

[0083] The second switch unit 26 is constructed in the same way as the first switch unit 24 and has a second busbar 62, which is designed to correspond to the busbars 36. The switch unit 26 also has a second further busbar 64 and a second contact bridge 66. A second moving contact 68 and a second further moving contact 70 are connected to the second contact bridge 66, which can be brought into mechanical contact with a second fixed contact 72 and a second further fixed contact 74, respectively, which are fastened to the second busbar 62 and the second further busbar 64, respectively.

[0084] The two contact bridges 46, 66 are connected to a common contact bridge support 76 and are mounted thereon for limited movement. For this purpose, the contact bridge support 76 has corresponding stops between which the contact bridges 46, 66 can be moved, and each contact bridge 46, 66 is supported on the contact bridge support 76 by means of a spring 78. The springs 78 are tensioned when the moving contacts 48, 50, 68, 70 rest against the respectively associated fixed contacts 42, 44, 72, 74. In this variant, the contact bridge support 76 is made of plastic and composed of several parts, namely three parts. In a variant not shown in detail, the contact bridge support 76 is made of one piece. In another further development, regardless of the specific design of the contact bridge carrier 76, the insulating plate 40 is connected to it, in particular molded onto it, and not to the further housing shell 30.

[0085] The contact bridge carrier 76 is rigidly attached to a longitudinally movable coupling rod 80. The coupling rod 80 is attached at its end to a coil armature 82 of an electric drive 84. This has a drive coil 86, which is an electrical coil, and the coupling rod 82 lies on the axis of the drive coil 86. The end face of the drive coil 86 facing the contact bridge carrier 76 is covered by a magnetic short-circuit plate 88 through which the coupling rod 80 protrudes. The coil armature 82 is supported on the short-circuit plate 88 by a spring 90 of the electric drive 84, wherein the spring 90 is compressed and thus tensioned when the coil armature 82 is located substantially within the drive coil 86. In this case, the contact bridge carrier 76 is in such a position that the two contact bridges 46, 66 connected to it are electrically conductively connected to the respective terminals 14, 16, 18, 20.In contrast, the spring 90 is relaxed when the coil armature 82 is at least partially outside the drive coil 86. In this case, the contact bridges 46, 66 are spaced from the respective associated busbars 36, 38, 62, 64, and the circuit breaker 12 is in the electrically non-conductive state. Thus, the electric drive 84 is associated with the two switch units 24, 26, and these are actuated by it.

[0086] The electric drive 84 is energized by a control unit 92, which comprises a circuit board and electrical and / or electronic components connected thereto (not shown in detail). The control unit 92 is connected to the electric drive 84, namely the drive coil 86, via a second switching element 94, which is actuated by the control unit 92, and a switching element 96, which are electrically connected in series. In summary, the switching element 96 and the second switching element 94 are electrically connected in series with each other and with the electric drive 84.

[0087] The second switching element 94 is a semiconductor switch, such as a MOSFET, and the switching element 96 is a mechanical switching contact, i.e., a mechanical switch. The mechanical switching contact is designed to be monostable, meaning it is either open or closed. If the mechanical switching contact is in the non-stable state and no other restrictions and / or forces are present, the mechanical switching contact is transferred to the stable state, i.e., open or closed, based on its design.

[0088] The control unit 92 is powered via an auxiliary connection 98, to which a low-voltage on-board power supply is connected in the assembled state, by means of which a direct current of 24 V is supplied. The electric drive 84 is thus operated with 24 V. A signal connection to an on-board computer (not shown in detail) of the motor vehicle 2 is also established via the auxiliary connection 98, by means of which the control unit 92 can be operated or instructed to behave in a specific way. It is also possible to query a switching state of the circuit breaker 12 via the auxiliary connection 98. The circuit breaker 12 further comprises a sensor 100, by means of which the electrical current conducted via the busbar 36 can be detected. For this purpose, the sensor 100 is designed, for example, as a Hall sensor or as a shunt.

[0089] The circuit breaker 12 further includes a slide 102, shown in perspective in Figure 6. The slide 102 is made of a single piece and is made of plastic. The slide 102 has a body 106 to which a bearing rod 108 is connected. The bearing rod 108 is guided in a guide (not shown in detail) of the housing shells 28, 30, so that the slide 102 is movably mounted. The bearing direction is parallel to the coupling rod 80, so that the coupling rod 80, the two contact bridges 46, 66, and the slide 102 are movably mounted in the same direction, i.e., parallel to one another.

[0090] Furthermore, an actuating element 110 arranged perpendicular to the bearing rod 108 is connected to the body 106. The body 106 has a blind-hole-like receiving opening 112 running parallel to the bearing rod 108, within which the coupling rod 80 is located. The slide 102 is supported on a circumferential, bead-like thickening of the coupling rod 80 via a spring 114. In a variant not shown in detail, the spring 114 is supported on one of the housing shells 28, 30 instead of the slide 102.

[0091] A second anchor 116 and a second anchor 118 are attached to the body 106 by means of adhesive or a clip connection. Attached to the opposite side of the body 106 are an anchor 120 and a further anchor 122, which are arranged congruently with the second anchor 116 and the second further anchor 118, respectively.

[0092] Figure 7 shows the switch unit 24 according to Figure 5, although the slide 102 and the second armature 116, as well as the second additional armature 118, which are arranged congruently with the armature 120 and the additional armature 122, are not shown. All armatures 116, 118, 120, 122 are structurally identical to one another and are each made of soft iron. They are also essentially wedge-shaped, arranged parallel to the coupling rod 80, and with the respective tip pointing in the direction of the electric drive 84. The armature 120 is assigned to a yoke 124 having a wedge-shaped recess 126. The size of the recess 126 corresponds to the size of the armature 120. The yoke 124 is made of soft iron and placed around the busbar 36. The yoke 124 is essentially annular and is opened only by means of the recess 126.Another yoke 128 is placed around the further busbar 38, which is identical in construction to the yoke 124 and thus has the recess 126.

[0093] As shown in Figure 8 in a sectional view parallel to the contact bridges 46, 66, a second yoke 130, which is assigned to the second armature 116, is placed around the second busbar 82. A second yoke 132, which is assigned to the second armature 118, is placed around the second busbar 64. All yokes 124, 128, 130, 132 are structurally identical to one another and each have the corresponding recess 126, which is wedge-shaped and configured to correspond to the respectively assigned armature 116, 118, 120, 122, which are also structurally identical to one another.

[0094] When an electrical current is to be conducted via the circuit breaker 12, i.e. in particular when the on-board electrical system 8 is to be operated, the second switching element 94 is closed by the control unit 92. Because the slide 102 is supported on the coupling rod 80 by the spring 114, the latter is located at a stop of its possible adjustment travel. In this position, the actuating element 110 rests against the switching element 96, which is in the electrically conductive state. The switching element 96 is designed to be monostable and open. As a result, the electric drive 84 is energized, and a magnetic field is formed in the drive coil 86, which is why the coil armature 82 is moved into the drive coils 86 against the force applied by the spring 90. As a result, the coupling rod 80 is also moved. Since the slide 102 is already at the stop of its adjustment travel, it no longer moves.However, spring 114 is further tensioned. If spring 114 is supported on one of the housing shells 28, 30, it is tensioned like spring 90. In this case, spring 114 is shortened compared to spring 90, for example, so that spring 114 is only tensioned during the final part of the movement of coupling rod 80.

[0095] Furthermore, due to the movement of the coupling rod 80, the contact bridge carrier 76 is also moved. Therefore, the moving contacts 48, 50, 68, 70 are brought against the respectively assigned fixed contacts 42, 50, 72, 74. Thus, the terminal 14 is connected with a low resistance to the further terminal 16, and the second terminal 18 is connected with a low resistance to the second further terminal 20. As a result, the electrical current flows via the circuit breaker 12, namely via each busbar 36, 38, 62, 64. Due to the respective shape of these and their arrangement, a magnetic field is induced in each yoke 124, 128, 130, 132, or the magnetic field surrounding the respective busbar 36, 38, 62, 74 is concentrated in them.

[0096] In this case, a comparatively high magnetic resistance is present due to the respective recess 126, and the magnetic field lines partially run through the associated armature 116, 118, 120, 122. As a result, a force is exerted on them in the direction of the respective recess 126. As a result, a force is also exerted on the slide 102 in the direction of the electric drive 84. However, at rated current, this force is not sufficient to counteract the counterforce provided by the spring 114, so that movement of the slide 102 does not occur. Thus, the slide 102 remains in its original position, and the switching element 96 is held in the electrically conductive state by means of the actuating element 110.

[0097] When the power supply to the vehicle electrical system 8 is to be terminated, the second switching element 94 is opened by the control unit 92. As a result, the power supply to the electric drive 84 is terminated. If the control unit 90 (see rudimentary design or omitted), no electrical voltage is applied to the terminal 98, for example, and thus the power supply to the electric drive 84 is also terminated. Thus, only the force provided by the spring 90 and by the spring 114, provided the latter is supported on one of the housing shells 28, 30, acts on the coil armature 82, so that the coil armature 82 is moved out of the drive coil 86. As a result, the contact bridges 46, 66 are moved and thus the moving contacts 48, 50, 68, 70 are spaced apart from the respectively associated fixed contacts 42, 50, 72, 74, which leads to a double interruption of the electrical current carried by each of the contact bridges 46, 66.If an arc is formed, it is extinguished by the respective arcing chamber 52, 60.

[0098] If the electrical current flowing increases during the desired energization of the on-board electrical system 8, for example due to a fault, this is detected by sensor 100. If the electrical current exceeds a second limit value, which corresponds to twice the rated current, i.e. 400 A, the second switching element 94 is actuated by the control unit 92, thus ending the energization of the electric drive 84. The circuit breaker 12 is thus also transferred to the electrically non-conductive state. The existing magnetic forces between each yoke 124, 128, 130, 132 and the respectively associated armature 116, 118, 120, 122 are not yet sufficient in this case to move the slide 102. In summary, if the electrical current flowing via the busbar 36 exceeds the second limit value, the second switching element 94 is actuated by the control unit 92.

[0099] However, if the conducted electrical current increases comparatively quickly, it is possible that it may exceed a first limit value, which is greater than the second limit value, before this has been correctly detected and / or processed by the control unit 92. The first limit value in this case is 700 A. If the first limit value is exceeded, the magnetic force acting between each yoke 124, 128, 130, 132 and associated armature 116, 118, 120, 122 is sufficient to overcompensate for the counterforce provided by the spring 114, so that the slide 102 is accelerated in the direction of the electrical drive 84. As a result, the actuating element 110 is released from the switching element 96, so that the current supply to the electrical drive 84 is interrupted. As a result, the moving contacts 48, 50, 68, 70 are again released from the respective associated fixed contacts 42, 50, 72, 74.Because the electrical current is no longer present or at least reduced, the magnetic interaction also decreases, so that the slide 102 is moved back to its original position by the spring 114, thus actuating and closing the switching element 96. However, the time until then is sufficient for the second switching element 94 to be actuated by the control unit 92, so that the electric drive 84 is not energized again despite the switching element 96 being closed.

[0100] If the control unit 92 and / or the second switching element 94 are not present, the actuation of the switching element 96 results in the electric drive 84 being energized again. In this case, the electric current used is expediently not sufficient to move the coupling rod 80 again, in particular against the spring force of the spring 90 and possibly the spring 114. For this purpose, in particular, the application of an additional electrical voltage is required, in particular via the auxiliary connection 98. In other words, in particular the electric drive thus has two states, wherein in one state it is possible to move the coupling rod 80 against the spring force, and wherein in the other state only the coupling rod 80 can be held in the current position.In particular, the state is predetermined by energizing the auxiliary terminal 98, and the state in which movement of the coupling rod 80 against the spring force is possible is only realized briefly when the circuit breaker 12 is started up. To realize the two different states, the drive coil 86 is split in two, for example, and thus has two separate electrical coils. In this case, the number of turns of one of the electrical coils is reduced, and by energizing this, it is only possible to hold the coupling rod 80 in the current position. By energizing the other electrical coil of the drive coil 86, however, it is possible to move the coupling rod 80 against the force applied by the spring 90.

[0101] The circuit breaker 12 also has a leg spring 134 by means of which the

[0102] Slider 102 is loaded against the force of spring 114, as shown in Figure 9 in a vertical sectional view through the circuit breaker 12. In other words, a force is applied to the slider 102 in the direction of the electrical drive 84 by means of the leg spring 134. The force applied in this case, i.e. the acting force, can be adjusted by means of an adjusting screw 136 which protrudes through the housing 22. It is thus possible to adjust the acting force from outside the housing 22 by means of the adjusting screw 136. By means of this force, the force provided by the spring 114 is at least partially compensated, so that by actuating the adjusting screw 136 the first limit value can be changed and adapted to the respective application.If the spring 114 is supported on one of the housing shells 28, 30, however, a force is applied by the leg spring 134 that is directed away from the electric drive 84. This force thus corresponds to the force by which the slide 102 is held in its original position and thus to the first limit value. In summary, the slide 102 is spring-loaded, and the acting force is adjusted by the adjustment screw 136.

[0103] If, during operation of the circuit breaker 12, the electrical current carried by the busbar 36 exceeds a fourth limit value that is greater than the first limit value, the spring 114 is compressed comparatively strongly, and the bottom of the blind-hole-like receiving opening 112, shown in Figure 10 in a sectional view of the circuit breaker 12, strikes the end of the coupling rod 80, so that an additional force is exerted on it by the slide 102. Thus, after the current supply to the drive coil 86 is interrupted, the coupling rod 80 is subjected to a force not only by the spring 90, but also by the slide 102, which leads to an accelerated movement of the two contact bridges 46, 66. The depth of the receiving opening 112 is sufficiently large that the impact only occurs after the switching element 96 has been actuated.

[0104] In summary, the contact bridge 46 and the slide 102 are mounted parallel to one another in such a way that when the slide 102 moves, the current carried via the busbar 36, which is greater than the fourth limit value, causes the slide 102 to mechanically strike the coupling rod 80 to which the contact bridge 46 is connected. The fourth limit value is greater than the first limit value and, in this example, is 4,000 A. Due to the impact, a force is exerted on the coupling rod 80 and thus also on the contact bridge 46, which force is directed away from the fixed contact 42. The slide 102 only mechanically strikes the coupling rod 80 after the switching element 96 has been actuated by the slide 102.

[0105] The circuit breaker 12 further comprises a reclosing lockout 138, which is shown in Figure 11 in an enlarged detail in a sectional view. The reclosing lockout 138 has a first locking element 140, which is provided by the slide 102. This is an undercut of the body 106, i.e., in particular, a step. Furthermore, the reclosing lockout 138 has a second locking element 142, which is designed as a leaf spring, which is attached to one of the housing shells 28, 30 at the end, wherein the remaining free end is bent by substantially 90° so that it rests against the slide 102 but protrudes beyond the undercut at the end. The free end points in the direction of the electric drive 84. Thus, the second locking element 142 is fixed with respect to each of the two housing shells 28, 30 and consequently also with respect to the switching element 96 attached to them.

[0106] When the slide 102 is moved comparatively far in the direction of the electric drive 84 due to a comparatively strong magnetic force acting when the electric current exceeds a third limit value, the undercut is guided over the free end of the leaf spring, which engages it. The two locking elements 140, 142 are thus locked. In other words, the restart lock 138 is designed such that after a movement of the slide 102 due to the electric current conducted via the busbar 36, which is greater than the third limit value, the two locking elements 140, 142 are locked. This prevents the slide 102 from moving back to its original position, and the switching element 96 remains in the open state, i.e., actuated. Until the restart lock 138 is reset, it is therefore not possible to supply power to the vehicle electrical system 8 again.The third limit value is higher than the first limit value, so that locking only occurs at an increased electrical current. In the illustrated variant, the third limit value is equal to or lower than the fourth limit value. In this case, the third limit value is 3,500 A.

[0107] Figure 12 shows an alternative embodiment of the circuit breaker 12, which also includes the housing 22. Terminals 14, 16, 18, 20 are also incorporated into the housing. The auxiliary terminal 98, not shown in detail, is also present.

[0108] Within the housing 22, as shown in perspective in Figure 13, the two switch units 24, 26 with the housing shells 28, 30, 32, 34 are still arranged. Their geometric dimensions are slightly different compared to the previous embodiment. However, they are still flush with each other on the outside, and their arrangement is unchanged.

[0109] Figure 14 shows a perspective view of the switch unit 24 from one side, and Figure 15 shows a perspective view of the opposite side, with the housing shell 28 not shown. The design of the busbars 36, 38, the contact bridge 46, the fixed contacts 42, 44, and the moving contacts 48, 50 is essentially unchanged. The two arcing chambers 52, 60 are also still present. The contact bridge support 76 is also not modified, and the contact bridge 46 is still supported on it by means of the spring 78. The contact bridge support 76 is rigidly attached to the coupling rod 80, which is attached to the electric drive 84. Its construction has been slightly modified, but the essential components are also present, and their function and arrangement have essentially remained unchanged. The control unit 92, the second switching element 94 (not shown in detail), and the sensor 100 are also still present.

[0110] The slider 102 is still present, but unlike the previous embodiment, it is not movably mounted parallel to the coupling rod 80, but perpendicular to it and to the stacking direction of the housing shells 28, 30, 32, 34. The slider 102, shown in perspective in Figure 16, is also made of plastic and further comprises the body 106, to which the armatures 116, 118, 120, 122 are attached. In one variant, the second armature 116 and the armature 120 are combined into a common component. Likewise, the second further armature 118 and the further armature 122 are combined into a common component.

[0111] The actuating element 110 is tapered and extends in the direction in which the slide 102 is movably mounted. The actuating element 110 is supported on the monostable closed switching element 96, which is also designed as a mechanical switching contact. When the switching element 96 is closed, a force is applied to the actuating element 110 that counteracts the mobility of the slide 102. In other words, the slide 102 is supported on a lever of the mechanical switching contact 96, which is spring-loaded and, when actuated, opens the switching element 96.

[0112] On the side of the body 106 opposite the actuating element 110, an adjustment spring 144 is arranged, which is supported on a spring bearing 146. The adjustment spring 144 is a helical spring, and by means of this, a force is exerted on the switching element 96, which, however, does not yet lead to actuation, i.e., opening. The position of the spring bearing 146 is predetermined by the adjustment screw 136. In other words, when the adjustment screw 136 is rotated, the spring bearing 146 is displaced toward the slide 102 or spaced from it, so that compression of the adjustment screw 144 is changed. In other words, the force that holds the slide 102 back from actuating the switching element 96 is adjusted, and thus the first limit value.

[0113] The corresponding yoke 124, 128, 130, 132 is in turn placed around each busbar 36, 38, 62, 64. In this variant, as shown in Figure 17, where the slider 102 is not shown, the recess 126 is rectangular, so that each yoke 124, 128, 130, 132 is essentially U-shaped. The armatures 116, 118, 120, 122 are also rectangular. Here, too, only when the electrical current carried by the busbar 36 exceeds the first limit value is the force acting between the yokes 124, 128, 130, 132 and the associated armatures 116, 118, 120, 122 sufficient to press the slide 102 against the switching element 96 in such a way that the latter is actuated. When there is no longer any magnetic interaction or if it is reduced, the slide 102 is moved to its original position due to the design of the switching element 96, counter to the force applied by the adjustment spring 144, and the switching element 96 is opened.

[0114] Connected to the body 106 is the first locking element 140, which is designed as a locking hook, as shown in Figure 18 in a sectional view through the circuit breaker 12. When the slide 102 has been moved sufficiently toward the switching element 96, which occurs when the electrical current carried by the busbars 36 is greater than the third limit value, the first locking element 140 engages over the second locking element 142, which is designed as a locking lug and is integrally formed on one of the housing shells 28, 30. Thus, the restart lock 138 is also present here, and this can only be released by mechanically releasing the two locking elements 140, 142, which requires opening the housing 22.

[0115] In another embodiment of the circuit breaker 12, the slide 102 is pressed against the switching element 96 by means of the adjustment spring 144, which is thus held in the closed state. Only when the electrical current carried by the busbar 36 exceeds the first limit value is the force acting between the yokes 124, 128, 130, 132 and the associated armatures 116, 118, 120, 122 sufficient to space the slide 102 from the switching element 96 against the force applied by the adjustment spring 144. In this case, the switching element 96 is designed to be monostable open, so that the switching element 96 is opened due to the lack of load from the slide of a second switch. This leads to a termination of the current supply to the electric drive 84. In this case, for example, the control unit 92 is present or it is omitted, so that the current supply to the electric drive 84 is adjusted by means of the auxiliary connection 98.In this case, the electric drive 84 expediently also has the two different states. The invention is not limited to the exemplary embodiments described above. Rather, other variants of the invention can also be derived therefrom by those skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the individual exemplary embodiments can also be combined with one another in other ways without departing from the subject matter of the invention.

[0116] List of reference symbols

[0117] 2 motor vehicles

[0118] 4 energy storage

[0119] 6 pole

[0120] 8 On-board network

[0121] 10 Drive

[0122] 12 circuit breakers

[0123] 14 Connection

[0124] 16 additional connections

[0125] 18 second connection

[0126] 20 second additional connection

[0127] 22 housings

[0128] 24 switch unit

[0129] 26 second switch unit

[0130] 28 Housing shell

[0131] 30 additional housing shells

[0132] 32 second housing shell

[0133] 34 second additional housing shell

[0134] 36 Busbar

[0135] 38 additional busbars

[0136] 40 insulating plates

[0137] 42 fixed contact

[0138] 44 additional fixed contacts

[0139] 46 Contact bridge

[0140] 48 moving contact

[0141] 50 additional moving contacts

[0142] 52 Extinguishing chamber

[0143] 54 extinguishing element

[0144] 56 magnetic yoke

[0145] 58 guide plate

[0146] 60 additional fire chambers

[0147] 62 second busbar 64 second additional busbar

[0148] 66 second contact bridge

[0149] 68 second moving contact

[0150] 70 second further moving contact

[0151] 72 second fixed contact

[0152] 74 second further fixed contact

[0153] 76 contact bridge carriers

[0154] 78 spring

[0155] 80 coupling rod

[0156] 82 coil armature

[0157] 84 electric drive

[0158] 86 drive coil

[0159] 88 short-circuit plate

[0160] 90 spring

[0161] 92 Control unit

[0162] 94 second switching element

[0163] 96 switching element

[0164] 98 Auxiliary connection

[0165] 100 sensors

[0166] 102 sliders

[0167] 106 bodies

[0168] 108 bearing rod

[0169] 110 Actuating element

[0170] 112 Receiving opening

[0171] 114 spring

[0172] 116 second anchor

[0173] 118 second additional anchor

[0174] 120 anchors

[0175] 122 additional anchors

[0176] 124 yoke

[0177] 126 recess

[0178] 128 additional yoke

[0179] 130 second yoke 132 second additional yoke

[0180] 134 torsion spring

[0181] 136 Adjustment screw

[0182] 138 Restart lock 140 First locking element

[0183] 142 second locking element

[0184] 144 Adjustment spring

[0185] 146 spring bearing

Claims

Claims 1. Circuit breaker (12), the - a busbar (36) to which a fixed contact (42) is connected, - a contact bridge (46) which is movably mounted for this purpose and to which a moving contact (48) is connected, - an electric drive (84) by means of which the contact bridge (46) is driven, - a yoke (124) placed around the busbar (36) and - a movably mounted slide (102) to which an armature (120) is connected, and which is designed such that when a first limit value is exceeded by an electrical current conducted via the busbar (36), the slide (102) is moved due to a magnetic interaction between the armature (120) and the yoke (124), so that a switching element (96) electrically connected in series with the electrical drive (84) is actuated by means of the slide (102).

2. Circuit breaker (12) according to claim 1, characterized in that the switching element (96) is a mechanical switching contact.

3. Circuit breaker (12) according to claim 2, characterized by a control unit (92) by means of which a second switching element (94), which is electrically connected in series with the switching element (96), is actuated when a second limit value is exceeded by the electrical current conducted via the busbar (36), wherein the second limit value is less than or equal to the first limit value, and wherein the mechanical switching contact is designed to be monostable closed.

4. Circuit breaker (12) according to one of claims 1 to 3, characterized in that the slide (102) is spring-loaded, an acting force being adjusted by means of an adjusting screw (136).

5. Circuit breaker (12) according to one of claims 1 to 4, characterized by a reclosing lock (138) which has a first latching element (140) provided by the slide (102) and a second latching element (142) which is fixed with respect to the switching element (96), and which is designed such that after a movement of the slide (102) due to an electrical current carried via the busbar (36) which is greater than a third limit value which is greater than or equal to the first limit value, the two latching elements (140, 142) are moved, the switching element (96) being actuated.

6. Circuit breaker (12) according to one of claims 1 to 5, characterized in that the yoke (124) has a recess (126), the recess (126) and the armature (120) being wedge-shaped.

7. Circuit breaker (12) according to one of claims 1 to 6, characterized in that the contact bridge (46) and the slide (102) are mounted parallel to one another in such a way that when the slide (102) moves due to an electrical current carried via the busbar (36) which is greater than a fourth limit value which is greater than the first limit value, the slide (102) mechanically strikes a coupling rod (80) connected to the contact bridge (46), so that a force is exerted on the contact bridge (46) which is directed away from the fixed contact (42).

8. Circuit breaker (12) according to claim 7, characterized in that the contact bridge (46) and the slide (102) are mounted parallel to each other in such a way that the slide (102) only strikes the coupling rod (80) mechanically after the switching element (96) has been actuated.

9. Circuit breaker (12) according to one of claims 1 to 8, characterized by a further busbar (38) to which a further fixed contact (44) is connected, wherein a further moving contact (50) is connected to the contact bridge (46), wherein a further yoke (128) is placed around the further busbar (38), and wherein a further armature (122) is connected to the slide (102).

10. Circuit breaker (12) according to one of claims 1 to 9, characterized by a second busbar (62) to which a second fixed contact (72) is connected, wherein a second moving contact (68) is connected to a second contact bridge (66), wherein a second yoke (130) is placed around the second busbar (62), wherein a second armature (116) is connected to the slide (102), and wherein the two contact bridges (46, 66) are connected to a common, movably mounted contact bridge carrier (76).

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