Device for producing and disconnecting an electrical connection, and vehicle

Abstract

The invention relates to a device (100) for establishing and disconnecting an electrical connection, comprising: - at least one contact element (10) for contacting an electrical conductor (60), - at least one drive unit (20) for driving the at least one contact element (10) from a rest position to a contact position, - at least one locking element (30) for locking the at least one contact element (10) in the contact position, - at least one actuator (40) for actuating the at least one locking element (30), - at least one spring element (50), wherein the at least one spring element (50) is relaxed in the rest position and biased in the contact position, wherein the device (100) is configured to move the at least one contact element (10) from the rest position to the contact position by means of the at least one drive unit (20) in order to establish the electrical connection in the contact position.wherein the device (100) is further configured to release the locking of the at least one contact element (10) by means of the at least one actuator (40), wherein the at least one contact element (10) moves from the contact position back to the rest position due to the preload of the at least one spring element (50) in order to disconnect the electrical connection, and a vehicle (200) with a corresponding device (100).

Description

[0001] The invention relates to a device for making and breaking an electrical connection and a vehicle with a corresponding device.

[0002] In electrically powered vehicles, contactors are typically used to establish and disconnect the electrical connection between, for example, a high-voltage battery and the vehicle's electrical system. For safety reasons and to prevent self-discharge of the high-voltage battery, it is required that the high-voltage battery be disconnected from the vehicle's electrical system when inactive. Furthermore, disconnection of the electrical connection should also be possible during operation – for example, in the event of a fault.

[0003] From CN 2 01 985 046 U a contactor is known which uses an electric motor to establish and disconnect an electrical connection.

[0004] The technical problem is to create a device and a vehicle that improve safety and energy efficiency when making and disconnecting an electrical connection.

[0005] The solution to the technical problem is provided by the articles with the features of the independent claims. Further advantageous embodiments of the invention are described in the dependent claims.

[0006] A device for making and breaking an electrical connection is proposed, comprising: at least one contact element for contacting an electrical conductor, at least one drive device for driving the at least one contact element from a rest position to a contact position, at least one locking element for locking the at least one contact element in the contact position, at least one actuator for actuating the at least one locking element, at least one spring element, wherein the at least one spring element is relaxed in the rest position and is pre-tensioned in the contact position, wherein the device is configured to move the at least one contact element from the rest position to the contact position by means of the at least one drive device in order to establish the electrical connection in the contact position, wherein the device is further configured to release the locking of the at least one contact element by means of the at least one actuator, wherein the at least one contact element moves back from the contact position to the rest position due to the preload of the at least one spring element in order to break the electrical connection.

[0007] A further proposal is a vehicle comprising at least one device according to an embodiment described in this disclosure. The vehicle can be, for example, a passenger car, a truck, or a motorcycle. Alternatively, the vehicle can be a rail vehicle, an aircraft, or a watercraft. In particular, the vehicle is a hybrid or electric vehicle. Naturally, the technical effects and advantages mentioned below for the device also apply to the vehicle.

[0008] The device offers several technical advantages. Firstly, once the contact element is locked, the drive unit does not need to exert any force to hold it in the contact position. This improves energy efficiency, as the drive unit can be de-energized, for example, while the contact element is in the contact position. Secondly, the device enhances safety when disconnecting the electrical connection, as the pre-tensioned spring element allows the contact element to be quickly returned from the contact position to its rest position. The drive unit is not required to release the lock, as the actuator handles this release. Finally, the device offers the advantage of reversible electrical connection and disconnection, and allows for emergency shutdown, even under load.

[0009] The device is, in particular, part of a vehicle's electrical system. The device can be located, for example, between a high-voltage battery and a vehicle component. The component could be, for example, the vehicle's traction motor. The device can also be referred to as a contactor or switch. The device serves, for example, to switch the component on or off. In the contact position, the electrical connection is established, so that, for example, the component can be supplied with current from the high-voltage battery. The contact position can therefore also be referred to as the "on" position. In the rest position, however, the electrical connection is broken, so that, for example, the component cannot be supplied with current from the high-voltage battery, and the high-voltage battery is decoupled from the vehicle's electrical system. The rest position can therefore also be referred to as the "off" position.

[0010] The electrical conductor can, for example, form an electrical line from the high-voltage battery to the consumer, or be part of such an electrical line. The electrical conductor can be configured as a phase conductor or neutral conductor, particularly if the current being conducted is, for example, alternating current.

[0011] The contact element can be designed as a contact bridge. In the contact position, the contact element can, for example, electrically connect two free ends of the electrical conductor to establish the electrical connection. The contact element can be part of the electrical connection in the contact position. Alternatively, in the contact position, the contact element can arrange a portion of the electrical conductor—for example, by deforming the conductor—in such a way that the electrical connection between the free ends of the conductor is established without the contact element itself being part of the electrical connection. In this case, the contact element can be designed as a so-called hinged armature.

[0012] The drive unit can be designed as an electric motor, in particular as a stepper motor or servo motor. A particularly precise positioning of the contact element can be achieved with the aid of the stepper motor or servo motor. The servo motor, in particular, enables a particularly high switching speed – i.e., a particularly high speed when moving the contact element from the rest position to the contact position. The drive unit can be operated with a low voltage, in particular a 12-volt voltage. The drive unit can, for example, drive the contact element via a gearbox. The gearbox can, for example, convert a rotational movement of the drive unit into a linear movement of the contact element. The gearbox can, for example, have at least one gear and at least one rack. The gear can, for example,The gear is arranged on a shaft of the drive unit, with the rack positioned between the gear and the contact element. The contact element and the rack can also form a single, continuous component. The transmission can, in particular, be designed as a two-stage transmission. This will be explained in more detail below.

[0013] The spring element is designed to be mechanically resilient. For example, the spring element can be or comprise a coil spring. Alternatively, the spring element can be pneumatically or magnetically resilient. Other spring mechanisms are also possible. The spring element can be pre-tensioned by means of the drive unit. The spring element is designed to store potential energy in the form of pre-tension in order to convert this energy into the movement of the contact element from the contact position to the rest position when the locking mechanism is released. The spring element can be arranged, for example, between the contact element or the rack and a support of the device.

[0014] The locking element can be designed as a metal spring with a locking pin. The locking element can be made of or incorporate a ferromagnetic material. In the contact position, the locking element, particularly the locking pin, can engage in a designated detent notch to lock the contact element. The position of the locking element after engagement can also be referred to as the detent position of the locking element. For example, the contact element or the rack can have the detent notch. In the rest position, the contact element or the rack can be, for example, offset relative to the locking element, so that the locking element cannot engage in the detent notch. Other locking mechanisms are also possible.

[0015] The actuator can be designed as an electromagnetic coil. In particular, the electromagnetic coil can interact electromagnetically with the locking element, and further, especially, with the ferromagnetic material described above. The actuator can be operated with a low voltage, in particular a 12-volt voltage. The actuator can actuate the locking element via an actuator force. The actuator force can, in particular, be an electromagnetic actuator force. The actuator has, in particular, a lower power consumption than the drive unit. The actuator force required to actuate the locking element can, for example, be less than the drive force of the drive unit required to move the contact element. The actuator can therefore be smaller.

[0016] In one embodiment, the device is configured such that the at least one actuator establishes and maintains the locking position via an actuator force, whereby the locking position is only released when the at least one actuator no longer actuates the at least one locking element via the actuator force. In this way, the locking position can only be established and maintained if the actuator is capable of applying the actuator force. This increases safety because, in the event of a fault—e.g., a power failure to the actuator—the locking position cannot be established at all, or it is immediately released and the electrical connection is safely severed. The device is thus specifically designed so that the at least one actuator releases the locking position without the actuator force.

[0017] In one embodiment, at least one gearbox is arranged between the at least one drive unit and the at least one contact element, wherein the at least one gearbox has a variable transmission ratio. With the aid of the gearbox, for example, a drive force and a drive speed of the drive unit can be translated into an actuating force and an actuating speed. The variable transmission ratio allows the spring element to be effectively pre-tensioned. Due to the variable transmission ratio, the actuating force and the actuating speed can be varied, for example, along an actuating path. The actuating path can, for example, be the path of the contact element from the rest position to the contact position, or at least a partial path along this path. The variable transmission ratio allows the actuating force to be varied, for example, depending on a restoring force of the spring element.The restoring force of the spring element along the travel path can be non-linear and may be known beforehand, for example, from experiments. To enable the variable transmission ratio, the distance between the teeth can vary, for example, along the rack. This can also be referred to as the tooth pitch – where a large tooth spacing results in a small tooth pitch and a small tooth spacing results in a large tooth pitch. The variable transmission ratio can change continuously, especially along the travel path.

[0018] In one embodiment, the transmission ratio of the at least one gear unit varies from low to high, particularly when establishing an electrical connection. This reduces the time required to establish the electrical connection—this time can also be referred to as the switching time. Due to the low transmission ratio at the beginning of the travel range, a high switching speed can be achieved with a correspondingly low actuating force. Towards the end of the travel range, however, the restoring force of the spring element can increase, so that in this region of the travel range, the actuating force increases due to the high transmission ratio, and the switching speed decreases accordingly. The low transmission ratio can be achieved, for example, by a small tooth pitch. The high transmission ratio can be achieved, for example, by a large tooth pitch.Naturally, the transmission ratio can vary from high to low when disconnecting the electrical connection.

[0019] In one embodiment, at least one contact spring is arranged between the at least one drive unit and the at least one contact element. The contact spring is pre-tensioned in the contact position such that the contact element makes contact with the electrical conductor with a contact force. The contact spring allows for the generation of a defined contact force, enabling the electrical connection to be established with a particularly low contact resistance. This reduces electrical losses in the conductor and thus improves energy efficiency. The contact spring can, for example, be designed as a coil spring. The contact spring can be arranged, for example, between the drive unit or the rack and the contact element. The contact spring can be pre-tensioned by means of the drive unit. The contact force can, for example, have a value of 10 to 20 newtons.For example, in the contact position, the contact spring can exert the contact force on the contact element, whereby the contact element is pressed with the contact force, e.g., against the free ends of the electrical conductor.

[0020] In one embodiment, the device is configured to move the at least one contact element from the contact position to the rest position using the at least one drive unit, in order to disconnect the electrical connection. This provides a fallback option for disconnecting the electrical connection, for example, in the event of a spring element breaking. Furthermore, the drive unit can assist in disconnecting the electrical connection, for example, by providing an additional disconnecting force to the restoring force of the spring element. This is particularly advantageous if micro-welds occur between the electrical conductor and the contact element, which can be broken by the additional disconnecting force. The drive unit can move the contact element from the contact position to the rest position in a direction opposite to the movement from the rest position to the contact position.

[0021] In one embodiment, the device comprises at least one laminated core and / or at least one arc-extinguishing magnet. This allows an arc, which can occur when the electrical connection is broken (e.g., between the electrical conductor and the contact element), to be extinguished safely and efficiently. The laminated core and / or the arc-extinguishing magnet can be arranged adjacent to the at least one contact element. The laminated core can comprise multiple sheets. This allows the arc generated during current separation to be split into several partial arcs. The laminated core can be made of an electrically conductive and / or thermally conductive material, particularly with a melting point above 1400°C. This allows as much energy as possible to be extracted from the arc. By splitting the arc within the laminated core, it can be extinguished and thus lose its harmful effects.The arc-extinguishing magnet can be designed as an electromagnetic coil or as a permanent magnet. A magnetic field can be generated using the arc-extinguishing magnet. The magnet is specifically arranged such that the generated magnetic field acts perpendicular to an electric arc that forms between the electrical conductor and the contact element. In particular, the arc-extinguishing magnet can be arranged relative to the laminated core such that the magnetic field drives the arc into the core. This extinguishes the arc particularly efficiently.

[0022] In one embodiment, the device comprises at least one further contact element for contacting another electrical conductor, wherein the device is configured such that the at least one contact element and the at least one further contact element are driven by means of the at least one drive unit. In this way, an electrical connection can be established between two separate electrical conductors by means of the drive unit. In particular, the electrical connection can be established or broken simultaneously between both conductors by means of the drive unit. In this case, the at least one contact element can also be referred to as the at least one first contact element. For example, the drive unit can have a gear that drives the first contact element via a first rack and the further contact element via a further rack.The electrical conductor may have a higher electrical potential than the other electrical conductor during operation. The device may further include: . at least one further locking element for locking the at least one further contact element in a further contact position, at least one further actuator for actuating the at least one further locking element, at least one further spring element, wherein the at least one further spring element is relaxed in a further rest position and is pre-tensioned in the further contact position.

[0023] The device is specifically designed to move the at least one further contact element from the further rest position to the further contact position by means of the at least one drive unit in order to establish the electrical connection. Furthermore, the device can be designed to release the locking mechanism of the at least one further contact element by means of the at least one further actuator, whereby the at least one further contact element moves from the further contact position back to the further rest position due to the preload of the at least one further spring element in order to break the electrical connection.

[0024] In one embodiment, the device is configured such that the at least one locking element locks the at least one contact element and the at least one further contact element. This ensures that both contact elements can be locked and unlocked simultaneously. In particular, the device can be configured such that the at least one actuator unlocks the at least one contact element and the at least one further contact element. The locking element can, for example, extend over both contact elements or the racks used in the transmission to lock both contact elements simultaneously. In this case, the locking element can be configured as a locking bridge.

[0025] The invention is explained in more detail using exemplary embodiments. The figures show: Fig. 1 is a schematic representation of an embodiment of a vehicle with a device in a contact position, Fig. 2 is a schematic representation of an embodiment of a vehicle with a device in a rest position, and Fig. 3 is a schematic representation of an embodiment of a two-stage transmission of the device.

[0026] Fig. 1 Figure 1 shows a schematic representation of an embodiment of a vehicle 200 designed as a passenger car with a device 100 for establishing and disconnecting an electrical connection between a high-voltage battery 210 of the vehicle 200 and a traction motor 220 of the vehicle 200.

[0027] The in Fig. 1 The device 100 shown is in a contact position, i.e. the electrical connection between the high-voltage battery 210 and the traction motor 220 is established.

[0028] The device 100 comprises a contact element 10 designed as a contact bridge for contacting an electrical conductor 60. The electrical conductor 60 connects, for example, a negative terminal (indicated by a minus sign) of the high-voltage battery 210 to a terminal (not shown) of the traction motor 220. The electrical conductor 60 has two free ends 61, 62, which are contacted by means of the contact element 10 to establish the electrical connection.

[0029] The device 100 further comprises another contact element 11 for contacting another electrical conductor 70. The electrical conductor 70 connects, for example, a positive terminal (indicated by a plus sign) of the high-voltage battery 210 to a terminal (not shown) of the traction motor 220.

[0030] With the aid of a drive unit 20 designed as a stepper motor, the contact elements 10, 11 can be moved from a rest position to the contact position in order to establish the electrical connection.

[0031] A gearbox is arranged between the drive unit 20 and the contact elements 10, 11. The gearbox comprises a gear 90 and two racks 91, 93. The gear 90 is, for example, arranged on a shaft of the drive unit 20. The racks 91, 93 are arranged between the gear 90 and the contact elements 10, 11. By means of the gearbox, a rotational movement of the drive unit 20 can thus be converted into a linear movement of the contact elements 10, 11.

[0032] The linear movement of the contact elements 10, 11 from the rest position to the contact position pre-tensions two spring elements 50, 51 of the device 100, which are designed as coil springs. The spring elements 50, 51 are arranged between the respective racks 91, 93 and associated supports 105, 106. The function of the spring elements 50, 51 will be explained in more detail below.

[0033] The gearbox has in particular a variable transmission ratio (not shown) in order to vary, for example, the actuating force of the contact elements 10, 11 depending on a restoring force of the spring elements 50, 51.

[0034] In the contact position, the contact elements 10, 11 are each locked by a locking element 30, 31 of the device 100, designed as a metal spring, so that the contact elements 10, 11 remain positioned in the contact position and the drive unit 20 can be de-energized. For this purpose, the locking elements 30, 31 each engage, for example, with a locking pin (in Fig. 1 The respective free ends of the locking elements 30, 31 engage in a designated detent notch 92, 94. This position of the locking elements 30, 31 can also be referred to as the detent position of the locking elements 30, 31. The detent notches 92, 94 can be provided in the respective racks 91, 93.

[0035] To the in Fig. 1 To actuate the locking elements 30, 31 shown, the device 100 comprises two actuators 40, 41 designed as coils. The locking elements 30, 31 can be engaged in the detent position by actuation (this is shown in Fig. 1(as shown). The actuators 40, 41 can thus actuate the respective locking mechanism of the contact elements 10, 11 via an electromagnetic actuator force, thereby establishing and maintaining the locking position. In particular, the actuator force holds the locking elements 30, 31 in the detent position as long as the high-voltage battery 210 is to be electrically connected to the traction motor 220. The locking elements 30, 31, designed as metal springs, are thus pre-tensioned with a restoring force during the locking action. The locking action can be released by disconnecting the actuators 40, 41, thus preventing the locking pins of the locking elements 30, 31 from being pressed into the detent notch. The restoring force of the locking elements 30, 31, designed as metal springs, then disengages the locking pins from the detent notches 92, 94.The locking of the contact elements 10, 11 is thus achieved by means of the actuators 40, 41 and released by means of the restoring force of the locking elements 30, 31. A reverse operation is also possible, in which the locking of the contact elements 10, 11 is achieved by means of the restoring force of the locking elements 30, 31 and released by means of the actuators 40, 41.

[0036] The previously explained preload of the spring elements 50, 51 is used to quickly move the contact elements 10, 11 from the contact position back to the rest position after the locking mechanism is released. For the in Fig. 1In the illustrated embodiment, where the actuators 40, 41 remain energized to maintain the locking mechanism, neither the actuators 40, 41 nor the drive unit 20 need to be energized to disconnect the electrical connection. This increases the safety of the device 100, since disconnecting the electrical connection also works, for example, in the event of a power failure, e.g., due to a broken cable.

[0037] Furthermore, a contact spring 80, 81, designed as a spiral spring, is arranged between the drive unit 20 and the contact elements 10, 11. In the contact position, the contact springs 80, 81 are pre-tensioned between the racks 91, 93 and the contact elements 10, 11 such that the contact elements 10, 11 contact the free ends 61, 62, 71, 72 of the electrical conductors 60, 70 with a defined contact force of, for example, 15 Newtons. This reduces the electrical contact resistance between the electrical conductors 60, 70 and the respective contact elements 10, 11 to such an extent that electrical losses during energy transmission can be kept low.

[0038] The contact elements 10, 11 can also be moved from the contact position to the rest position using the drive unit 20 if the electrical connection is to be broken, for example, with an additional separating force. It may happen, for instance, that micro-welds form between the contact elements 10, 11 and the free ends 61, 62, 71, 72 of the electrical conductors 60, 70. These can be broken up with the additional separating force of the drive unit 20.

[0039] The device 100 can include a laminated core (not shown) and / or a blow-out magnet (not shown) which can extinguish any arcs between the free ends 61, 62, 71, 72 of the electrical conductors 60, 70 and the contact elements 10, 11 when the electrical connection is broken. This protects the device 100 from damage.

[0040] The in Fig. 1The device 100 shown also includes a housing 110, which encloses the aforementioned components of the device 100. The free ends 61, 62, 71, 72 of the electrical conductors 60, 70, which can be contacted by means of the contact elements 10, 11, are arranged in the housing 110. The housing 110 has four electrical terminals 111, 112, 113, 114 to allow the device 100 to be installed in the vehicle 200 in a pre-assembled state and to connect the sections of the two electrical conductors 60, 70 located outside the device to the terminals 111, 112, 113, 114. This simplifies the installation of the device 100 in the vehicle 200 and avoids unnecessary electrical wiring inside the vehicle 200.

[0041] Fig. 2 serves to better understand the invention and, in contrast to Fig. 1a schematic representation of an embodiment of a vehicle 200 with a device 100 for establishing and disconnecting an electrical connection between a high-voltage battery 210 of the vehicle 200 and a traction motor 220, wherein the device 100 is in a rest position - i.e. the electrical connection between the high-voltage battery 210 and the traction motor 220 is disconnected.

[0042] Fig. 3 shows a schematic representation of an embodiment of a two-stage transmission 95 of the device 100.

[0043] The two-stage gearbox 95 allows for the creation of a variable gear ratio. The two-stage gearbox 95 features the following: a gear 90, which is driven by the drive unit 20, two gears 96, 97 of different sizes that are fixedly connected to each other, and a rack 91.

[0044] Gear 96 has a larger diameter than gear 97. Due to their fixed connection, gears 96 and 97 rotate at the same speed. Gear 90 drives the smaller gear 97 via the larger gear 96. Furthermore, the diameter of gear 90 is larger than that of gear 97.

[0045] The rack 91 has a first tooth section 98 and a second tooth section 99. At the beginning of a travel path, the gear 90 engages simultaneously with the large gear 96 and with the first tooth section 98 of the rack 91. In the first tooth section 98 of the rack 91, the teeth are widely spaced to achieve a low gear ratio. This allows the travel path along the first tooth section 98 to be traversed with low actuating force but high actuating speed. As the travel path continues, the gear 90 disengages from the first tooth section 98 and drives the small gear 97 via the large gear 96. The small gear 97, in turn, engages with the second tooth section 99 of the rack 91. In the second tooth section 99, the teeth are closer together to achieve a high gear ratio.This allows the travel distance along the first tooth section 98 to be covered with a lower actuating speed, but with a higher actuating force. Reference symbol list

[0046] 10 Contact element 11 Further contact element 20 Drive unit 30 Locking element 31 Further locking element 40 Actuator 41 Further actuator 50 Spring element 51 Further spring element 60 Electrical conductor 61, 62 Free end of electrical conductor 70 Further electrical conductor 71, 72 Free end of further electrical conductor 80 Contact spring 81 Further contact spring 90 Gear 91 Rack 92 Detent notch 93 Further rack 94 Further detent notch 95 Two-stage gearbox 96 Large gear 97 Small gear 98 First tooth section 99 Second tooth section 100 Device 105, 106 Support 110 Housing 111, ..., 114 Electrical connection 200 Vehicle 210 High-voltage battery 220 Traction motor

Claims

1. Device (100) for establishing and disconnecting an electrical connection, comprising: - at least one contact element (10) for contacting an electrical conductor (60), - at least one drive unit (20) for driving the at least one contact element (10) from a rest position to a contact position, - at least one locking element (30) for locking the at least one contact element (10) in the contact position, - at least one actuator (40) for actuating the at least one locking element (30), - at least one spring element (50), wherein the at least one spring element (50) is relaxed in the rest position and biased in the contact position, wherein the device (100) is configured to move the at least one contact element (10) from the rest position to the contact position by means of the at least one drive unit (20) in order to establish the electrical connection in the contact position,wherein the device (100) is further configured to release the locking of the at least one contact element (10) by means of the at least one actuator (40), wherein the at least one contact element (10) moves from the contact position back to the rest position due to the preload of the at least one spring element (50) in order to disconnect the electrical connection.

2. Device (100) according to claim 1, characterized by the fact that the device (100) is designed such that the at least one actuator (40) establishes and maintains the locking via an actuator force, wherein the locking is only released when the at least one actuator (40) no longer actuates the at least one locking element (30) via the actuator force.

3. Device (100) according to one of the preceding claims, characterized by the fact thatat least one gear unit (95) is arranged between the at least one drive unit (20) and the at least one contact element (10), wherein the at least one gear unit (95) has a variable transmission ratio.

4. Device (100) according to claim 3, characterized by the fact that the gear ratio of the at least one gearbox (95) varies from low to high.

5. Device (100) according to any one of the preceding claims, characterized by the fact that between the at least one drive device (20) and the at least one contact element (10) at least one contact spring (80) is arranged, wherein the at least one contact spring (80) is pre-tensioned in the contact position such that the at least one contact element (10) contacts the electrical conductor (60) with a contact force.

6. Device (100) according to one of the preceding claims, characterized by the fact thatthe device (100) is designed to move the at least one contact element (10) from the contact position to the rest position by means of the at least one drive device (20) in order to disconnect the electrical connection.

7. Device (100) according to one of the preceding claims, characterized by the fact that the device (100) comprises at least one laminated core and / or at least one blowing magnet for arc quenching.

8. Device (100) according to one of the preceding claims, characterized by the fact that the device (100) comprises at least one further contact element (11) for contacting a further electrical conductor (70), wherein the device (100) is designed such that the at least one contact element (10) and the at least one further contact element (11) are driven by means of the at least one drive device (20).

9. Device (100) according to claim 8, characterized by the fact thatthe device (100) is designed to lock the at least one contact element (10) and the at least one further contact element (11) with the aid of the at least one locking element (30).

10. Vehicle (200) comprising at least one device (100) according to any one of claims 1 to 9.

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