Reversible, pyrotechnic contacting device for an onboard high-voltage electrical system of a motor vehicle

Abstract

The invention relates to a contacting device (1) for an onboard high-voltage electrical system of a motor vehicle for providing a reversible electric connection between at least two onboard-electrical-system components of the onboard high-voltage electrical system, comprising: - a switching unit (3) for disconnecting the electric connection in a first switching state and for establishing the electric connection in a second switching state, - an actuation unit (7) for actuating the switching unit (3), and - a pyrotechnic ignition unit (11) for activating the actuation unit (7), with the actuation unit (7) being designed, after having been activated by the pyrotechnic ignition unit (11), to perform a switching cycle of the switching unit (3).

Description

[0001] Reversible, pyrotechnic contact device for a high-voltage electrical system of a motor vehicle

[0002] The invention relates to a contacting device for a high-voltage electrical system of a motor vehicle for providing a reversible electrical connection between at least two electrical system components of the high-voltage electrical system. The contacting device has a switching unit for disconnecting the electrical connection in a first switching state and for establishing the electrical connection in a second switching state. Furthermore, the contacting device has an actuating unit for actuating the switching unit and a pyrotechnic ignition unit for activating the actuating unit. The invention also relates to a high-voltage electrical system and a motor vehicle.

[0003] In this case, the focus is on high-voltage electrical systems for motor vehicles, particularly electric or hybrid vehicles. Such high-voltage electrical systems typically have a high-voltage energy storage device, which can be coupled to other high-voltage components, such as an electric motor, via an intermediate circuit. In the event of a fault, for example, in the event of a motor vehicle accident, it is common practice for safety reasons to disconnect and / or establish electrical connections between the components of the high-voltage electrical system, for example, to connect a discharge circuit for discharging the intermediate circuit to the intermediate circuit. For this purpose, contacting devices are known from the prior art, which establish or break the electrical connection using a pyrotechnic ignition unit or a propellant charge.Such pyrotechnic contact devices are generally irreversible, meaning they can only establish or break the electrical connection.

[0004] DE 102019211725 A1 discloses a pyrotechnic contacting device in the form of a reversible fuse device for electrically connecting and disconnecting power lines. This device comprises an electrically insulating housing and a cavity enclosed by the housing, in which a fuse element and a propellant charge are arranged. The fuse element has an electrically conductive connecting element and an electrically insulating separating element. Ends of the power lines are arranged separately from one another in the housing. A connecting position and a separating position are provided for the fuse element, with the connecting element of the fuse element being arranged between the ends of the power lines in the connecting position.If the propellant charge is detonated in the cavity, the fuse element is pushed from the connected position to the disconnected position, so that the disconnecting element of the fuse element is located between the ends of the power lines in the disconnected position. Furthermore, the fuse element can also be moved back from the disconnected position to the connected position, for example, manually. This manual resetting of the fuse element is complex and can only be performed by qualified personnel. Furthermore, this contacting device described in the prior art is unsuitable for providing rapid resetting if this must be performed, for example, within milliseconds.

[0005] The object of the present invention is to provide a safe and easily and quickly resettable pyrotechnic electrical contact for a high-voltage electrical system of a motor vehicle.

[0006] This object is achieved according to the invention by a contacting device, a high-voltage electrical system, and a motor vehicle having the features according to the respective independent patent claims. Advantageous embodiments of the invention are the subject of the dependent patent claims, the description, and the figures.

[0007] A contacting device according to the invention for a high-voltage electrical system of a motor vehicle serves to provide a reversible electrical connection between at least two electrical system components of the high-voltage electrical system. The contacting device has a switching unit for disconnecting the electrical connection in a first switching state and for establishing the electrical connection in a second switching state. Furthermore, the contacting device has an actuating unit for actuating the switching unit and a pyrotechnic ignition unit for activating the actuating unit. After activation by the pyrotechnic ignition unit, the actuating unit is designed to carry out a switching cycle of the switching unit and, for this purpose, to transfer the switching unit from one switching state to the other switching state for a predetermined period of time.The invention also relates to a high-voltage electrical system for a motor vehicle having at least two electrical system components and at least one contacting device according to the invention. A motor vehicle according to the invention comprises a high-voltage electrical system according to the invention. The motor vehicle is preferably designed as an electric or hybrid vehicle. The high-voltage electrical system comprises, in particular, electrical system components in the form of high-voltage components of an electric drive train of the motor vehicle. For example, a first electrical system component can be designed as a high-voltage intermediate circuit and a second electrical system component as a discharge circuit, wherein the contacting device is designed to electrically connect the intermediate circuit to the discharge circuit for the predetermined period of time in the event of a fault, for example in the event of a crash of the motor vehicle, in order to discharge intermediate circuit capacitances.

[0008] The contacting device is arranged in particular in an electrical connecting line or high-voltage line of the high-voltage vehicle electrical system. For example, the switching unit for this purpose can have a plurality of electrical conductors, for example busbars, wherein end sections of the busbars can be designed as connections of the contacting device, for example plug contacts. This switching unit can assume two switching states: the first, open switching state, in which the electrical connection is separated or interrupted, and the second, closed switching state, in which the electrical connection is established. To provide the switching processes, i.e. to transfer the switching unit from the first to the second switching state and from the second to the first switching state, the actuating unit is provided, which is activated by the pyrotechnic ignition unit.The pyrotechnic ignition unit has at least one ignition element, for example, a squib or primer cap, which can be ignited by at least one ignition process. The actuating unit activated by the ignited ignition unit is designed to perform a complete switching cycle. In other words, the actuating unit performs two switching processes, during which the switching unit is moved from one switching state to the other and, after the expiration of the predetermined period of time, is returned to the original switching state, i.e., reset. The predetermined period of time comprises, in particular, a maximum of a few milliseconds.

[0009] Preferably, after activation by the pyrotechnic ignition unit, the actuating unit is designed to transfer the switching unit from the first, open switching state to the second, closed switching state and, after the predetermined period of time has elapsed, to return it to the first switching state. The contacting device thus establishes the electrical connection, for example, for connecting the discharge circuit to the intermediate circuit, for the predetermined period of time, before subsequently disconnecting the connection again and disconnecting the high-voltage vehicle electrical system.

[0010] The contacting device according to the invention thus has a switching unit that can be switched and reset solely by the ignition unit. This advantageously eliminates the need for manual resetting of the switching unit, and the switching unit is also suitable for providing fast switching operations.

[0011] In one embodiment of the invention, the actuating unit has an actuating element that can be moved by the pyrotechnic ignition unit and is designed to move a movable contact part of the switching unit to provide at least one of the switching states. In particular, the contacting device has a housing in which a partial region of the switching unit, the actuating unit, and the ignition unit are arranged, wherein the housing partially forms a guide cylinder for the actuating element designed as a piston. For example, the connections of the switching unit for connecting the contacting device to the electrical connecting line of the high-voltage vehicle electrical system can protrude from the housing. The actuating element, in particular a piston-like element, is designed to transmit its movement caused by the ignition unit to the movable contact part.The piston can be moved linearly in the guide cylinder and thus move the movable contact part to provide at least one of the switching operations.

[0012] It can be provided that the switching unit has two electrical conductors, for example busbars, wherein the movable contact part is designed as a partial region of one of the conductors that can be bent by the actuating element. In the first switching state, the bendable partial region of one conductor, for example one busbar, is arranged at a distance from the other conductor, which has a fixed contact point. The fixed contact point can, for example, be an end section of the other busbar arranged in the housing. To close the switching unit, i.e. to transfer the switching unit from the first to the second switching state, the actuating element bends the bendable partial region against the spring force in the direction of the fixed contact point of the other busbar, thus electrically connecting the two busbars.

[0013] It can also be provided that the movable contact part and the actuating element are designed as a single component. The movable contact part can, for example, be fastened to the actuating element and thus moved or displaced together with the actuating element. The movement of the actuating element thus corresponds to the movement of the movable contact part. The movable contact part thus forms an electrically conductive connecting piece which, for example, in the first switching state is arranged at a distance from two stationary contact points of the two conductors of the switching unit and which, in the second switching state, is arranged in contact with the two stationary contact points. For example, the actuating element can be designed as a piston and the movable contact part as a slip ring surrounding the piston.

[0014] According to a first variant of the invention, the ignition unit for carrying out the switching cycle has two ignition elements that can be fired at different times and are designed to move the actuating element and thus the movable contact part in opposite directions at different times to provide the switching cycle. The ignition elements are arranged, for example, on opposite sides of the actuating element in the guide cylinder. To close the switching unit, a first ignition element is initially fired by means of a first ignition signal, which moves the actuating element in a first direction and thereby brings the movable contact part into contact with the stationary contact part of the switching unit.To reopen the switching unit, after the predetermined period of time, the second ignition element is ignited by means of a second ignition signal, which moves the actuating element in a second direction opposite to the first direction and in the process releases the movable contact part again at least partially from the stationary contact part.

[0015] According to a second variant of the invention, the ignition unit has two ignition elements that can be fired at different times to carry out the switching cycle, and the actuating unit has a separating element, wherein a first ignition element is designed to move the actuating element and thus the movable contact part to provide the second switching state, and a second ignition element is designed to move the separating element to provide the first switching state, which separates at least one conductor of the switching unit, in particular away from the movable contact part. The actuating unit thus has the actuating element for closing the switching unit and the electrically insulating separating element for opening the switching unit. Here, it is therefore provided that the separating element opens the switching unit not by moving the movable contact part, but by separating at least one of the conductors of the switching unit.The separating element can also be designed as a piston movable in a guide cylinder. For example, an ignition element can be arranged in each of the opposing guide cylinders, so that the actuating element is moved along the first direction and the separating element is moved along the second direction.

[0016] According to a third variant of the invention, the pyrotechnic ignition unit for carrying out the switching cycle has an ignition element designed to move the actuating element and thereby the movable contact part in one direction. The movable contact part thereby establishes a sliding contact with a stationary contact part of the switching unit for the predetermined period of time, establishing the closed switching state. According to this variant, the movable contact part is pushed past the stationary contact part, so that the contact is only temporarily established as a sliding contact or sliding contact. The predetermined period of time in which the electrical connection is established can be adjusted, for example, by the sliding speed of the actuating element and / or the geometric dimensions of the movable contact part.

[0017] The variants of the invention in which two ignition elements and thus two ignition processes are required to carry out a switching cycle have the advantage that the second ignition process can be freely selected by applying the second ignition signal, thus allowing the predetermined period to be flexibly adjusted. The variant of the invention in which only one ignition element and thus only one ignition process is required to carry out a switching cycle has the advantage that the contacting device is particularly simple and cost-effective.

[0018] It proves advantageous if the contacting device has at least one discharge element, for example a discharge resistor, which is arranged together with the actuating unit, the ignition unit, and the switching unit in a housing. The contacting device is thus designed as a highly integrated component. The discharge element is electrically connected to the switching unit. By briefly closing the switching unit using the pyrotechnically activated actuating unit, the intermediate circuit is connected to the integrated discharge resistor of the contacting device for discharging and is disconnected again after discharging.

[0019] The embodiments presented with reference to the contacting device according to the invention and their advantages apply accordingly to the high-voltage vehicle electrical system according to the invention and to the motor vehicle according to the invention.

[0020] Further features of the invention emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combination, but also in other combinations or on their own.

[0021] The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings. They show:

[0022] Fig. 1a-1c a schematic representation of a first embodiment of a contacting device in different switching states;

[0023] Fig. 2a-2c a schematic representation of a second embodiment of a contacting device in different switching states;

[0024] Fig. 3a-3c a schematic representation of a third embodiment of a contacting device in different switching states; and

[0025] Fig. 4a-4c a schematic representation of a fourth embodiment of a contacting device in different switching states.

[0026] In the figures, identical and functionally identical elements are provided with the same reference numerals.

[0027] Fig. 1a, 1b and 1c, Fig. 2a, 2b and 2c, Fig. 3a, 3b and 3c as well as Fig. 4a, 4b and 4c each show a switching cycle for different embodiments of a contacting device 1 for a high-voltage on-board electrical system of a motor vehicle. Within a switching cycle, on-board electrical system components of the high-voltage on-board electrical system are temporarily electrically connected for a specific period of time via the contacting device 1. Such on-board electrical system components can be, for example, an intermediate circuit and a discharge circuit, which are temporarily connected to one another in the event of a vehicle crash before the high-voltage on-board electrical system is de-energized. For this purpose, the contacting device 1 has connections 2a, 2b, for example plug contacts, via which the contacting device 1 can be arranged in a high-voltage line of the high-voltage on-board electrical system connecting the on-board electrical system components.

[0028] The contacting device 1 comprises a switching unit 3 with a stationary contact part 3a and a movable contact part 3b. The switching unit 3 is arranged in sections in a housing 4 of the contacting device 1. The switching unit 3 has electrical conductors 5, 6, here busbars, whose first end sections 5a, 6a protrude from the housing 4 and form the connections 2a, 2b of the contacting device 1. The contacting device 1 has an actuating unit 7 for actuating, i.e., for switching, the switching unit 3. The actuating unit 7 here comprises an actuating element 8. The actuating element 8 is designed, for example, as a piston 9, which is mounted for linear displacement in a guide cylinder 10 of the housing 4. In addition, the contacting device 1 has a pyrotechnic ignition unit 11, which has at least one ignition element 12 and is designed to activate the actuating unit 7 by an ignition process of the ignition element 12.By activating the actuating unit 7, the actuating element 8 is moved, which transmits its movement to the movable contact part 3b and thus switches the switching unit 3.

[0029] According to Fig. 1a, 2a, 3a and 4a, the switching unit 3 has a first, open switching state in which the on-board power supply components are electrically isolated. In the event of a fault, for example in the event of an accident, the switching unit 3 is transferred from the first, open state to a second, closed state for the predetermined period of time, which is shown in Fig. 1b, 2b, 3b and 4b. As a result, for example, the intermediate circuit is temporarily electrically connected to the discharge circuit and discharged. Subsequently, after the predetermined period of time has elapsed, the switching unit 3 is transferred from the second, closed switching state back to the first, open switching state, which is shown in Fig. 1c, 2c, 3c and 4c. As a result, the on-board power supply components are again galvanically isolated from one another and the high-voltage on-board power supply is activated to ensure a safe state of the motor vehicle.

[0030] In a first embodiment of the contacting device 1 according to Fig. 1a, 1b and 1c, the stationary contact part 3a is formed by a stationary contact point 13 of a second end section 5b of the busbar 5 and the movable contact part 3b is formed by a bendable partial region 14 of a second end section 6b of the busbar 6. The ignition unit 11 has one ignition element 12. In the open switching state of the switching unit 3 according to Fig. 1a, the ignition element 12 is not ignited, the actuating element 8 is in a first position and the movable contact part 3b is in a first position in which the movable contact part 3b is arranged at least partially spaced from the stationary contact part 3a. Here, the bendable partial region 14 is bent upwards and thus does not touch the stationary contact point 13.

[0031] To temporarily close the switching unit 3, an ignition process Z of the ignition element 12 is initiated, for example signal-controlled, as shown in Fig. 1b, whereby the actuating element 8 moves along a first direction R1 into a second position and in the process moves the movable contact part 3b into a second position in which the movable contact part 3b contacts the stationary contact part 3a. Here, the bendable partial area 14 is bent by the actuating element 8 in the direction of the stationary contact point 13 until the bendable partial area 14 and the contact point 13 touch and the busbars 5, 6 are thus electrically connected. After the period of time has elapsed, the switching unit 3 is opened again, as shown in Fig. 1c. For this purpose, the contact element 12, which is caused by the ignition process Z from Fig.1b, the actuating element 8 moves further along the first direction R1 into a third position, thereby transferring the movable contact part 3b into a third position, in which the movable contact part 3b is again arranged at a distance from the stationary contact part 3a. Here, the flexible partial area 14 is bent downward by the actuating element 8, thus breaking the electrical connection between the busbars 5, 6. Therefore, as shown in Figs. 1a to 1c, only one firing process Z is required to provide the switching cycle, by which the flexible partial area 14 is moved past the stationary contact point 13 and temporarily touches it.

[0032] Fig. 2a to 2c show the switching cycle of a second embodiment of the contacting device 1. This differs from the first embodiment in that the ignition unit 11 has a further ignition element 12' in addition to the ignition element 12 and that the actuating unit 7 has a separating element 15 in addition to the actuating element 8. The switching unit 3 has the first, open switching state according to Fig. 2a. Both ignition elements 12, 12' are not ignited, the actuating element 8 and the separating element 15 are each in a first position and the movable contact part 3b is in the first position in which the movable contact part 3b is arranged at a distance from the stationary contact part 3a, at least in some areas. To provide the second switching state (see Fig. 2b), as already explained in connection with Fig.1b, the first ignition element 12 is ignited, whereby the actuating element 8 moves along the first direction R1 into the second position and in the process moves the movable contact part 3b into a second position in which the movable contact part 3b contacts the stationary contact part 3a. The second ignition element 12' remains untriggered and the isolating element 15 is still in the first position. After the period of time has elapsed, as shown in Fig. 2c, a further ignition process Z' of the second ignition element 12' is initiated to open the switching unit 3, so that the isolating element 15 moves from the first position along a second direction R2 opposite to the first direction R1 into a second position in which the isolating element 15 interrupts the electrical connection established via the busbars 5, 6. Here, the isolating element 15 severs the busbars 5, 6. To provide the switching cycle, as shown in Fig.2a to 2c, two ignition processes Z, Z' are required.

[0033] Fig. 3a to 3c show the switching cycle of a third embodiment of the contacting device 1. This differs from the first embodiment in that the movable contact part 3b and the actuating element 8 are designed as a single component 16. The movable contact part 3b is formed here by a slip ring 17 which surrounds the piston 9. The stationary contact part 3a is formed here by two stationary contact points 13, 13' of the second end sections 5b, 6b of the busbars 5, 6. When the component 16 is moved, the actuating element 8 and the movable contact part 3b move. During the switching cycle, the slip ring 17 is moved past the contact points 13, 13' along the first direction R1 by the one ignition process Z of the ignition element 12 and in the process contacts them temporarily, as shown in Fig. 3b.

[0034] 4a to 4c show the switching cycle of a fourth embodiment of the contacting device 1. This differs from the third embodiment in that the ignition unit 11 again has two ignition elements 12, 12', which are fired at different times to switch and reset the switching unit 3. During the first firing process Z of the ignition element 12 according to Fig. 4b, the actuating element 8 and thereby the stationary contact element 3b are moved from the first position along the first direction R1 into a second position in which the slip ring 17 touches the stationary contact points 13, 13'. During the second firing process Z' of the second ignition element 12' according to Fig. 4c, the actuating element 8 and thereby the stationary contact element 3b are moved from the second position along the second direction R2 back to the first position and the switching unit 3 is thus opened again.

Claims

Patent claims 1. Contacting device (1) for a high-voltage electrical system of a motor vehicle for providing a reversible electrical connection between at least two electrical system components of the high-voltage electrical system, comprising: - a switching unit (3) for disconnecting the electrical connection in a first switching state and for establishing the electrical connection in a second switching state, - an actuating unit (7) for actuating the switching unit (3), - a pyrotechnic ignition unit (11) for activating the actuating unit (7), characterized in that the actuating unit (7) is designed, after activation by the pyrotechnic ignition unit (11), to carry out a switching cycle of the switching unit (3).

2. Contacting device (1) according to claim 1, characterized in that the actuating unit (7) after activation by the pyrotechnic ignition unit (11) is designed to transfer the switching unit (3) from the first switching state to the second switching state and to return it to the first switching state after a predetermined period of time has elapsed.

3. Contacting device (1) according to claim 1 or 2, characterized in that the actuating unit (7) has an actuating element (8) which is movable by the pyrotechnic ignition unit (11) and which is designed to move a movable contact part (3b) of the switching unit to provide at least one of the switching states.

4. Contacting device (1) according to claim 3, characterized in that the contacting device (1) has a housing (4) in which a partial area of ​​the switching unit (3), the actuating unit (7) and the ignition unit (11) are arranged, wherein the housing (4) partially forms a guide cylinder (10) for the actuating element (8) designed as a piston (9).

5. Contacting device (1) according to claim 3 or 4, characterized in that the ignition unit (11) for carrying out the switching cycle has two ignition elements (12, 12') which can be ignited at a time offset and which are designed to move the actuating element (8) and thus the movable contact part (3b) in a time-delayed manner along opposite directions (R1, R2) to provide the switching cycle.

6. Contacting device (1) according to claim 3 or 4, characterized in that the ignition unit (11) for carrying out the switching cycle has two ignition elements (12, 12') which can be ignited at different times and the actuating unit (7) has a separating element (15), wherein a first ignition element (12) is designed to move the actuating element (8) and thus the movable contact part (3b) to transfer the switching unit (3) from the first to the second switching state, and a second ignition element (12') is designed to move the separating element (15) to return the switching unit (3) to the first switching state, which second ignition element (12') mechanically severs at least one conductor section of the switching unit (3), in particular away from the movable contact part (3b).

7. Contacting device (1) according to claim 3 or 4, characterized in that the pyrotechnic ignition unit (11) for carrying out the switching cycle has an ignition element (12) which is designed to move the actuating element (8) and thereby the movable contact part (3b) along a direction (R1), wherein the movable contact part (3b) temporarily makes a sliding contact with a stationary contact part (3b) of the switching unit (3) which establishes the closed switching state.

8. Contacting device (1) according to one of claims 3 to 7, characterized in that the switching unit (3) has two electrical conductors (5, 6), wherein the movable contact part (3b) is designed as a partial region (14) of one of the conductors (6) which can be bent by the actuating element (8).

9. Contacting device (1) according to one of claims 3 to 7, characterized in that the movable contact part (3b) and the actuating element (8) are formed by a component (16).

10. Contacting device (1) according to claim 9, characterized in that the actuating element (8) is designed as a piston (9) and the movable contact part is designed as a slip ring (17) surrounding the piston (9).

11. Contacting device (1) according to one of the preceding claims, characterized in that the contacting device (1) has at least one discharge element electrically connected to the switching unit, wherein the at least one discharge element, the actuating unit (7), the ignition unit (11) and the switching unit (3) are arranged in a common housing (4).

12. High-voltage electrical system for a motor vehicle with at least two electrical system components and at least one contacting device (1) according to one of the preceding claims.

13. High-voltage vehicle electrical system according to claim 12, characterized in that a first vehicle electrical system component is designed as a high-voltage intermediate circuit and a second vehicle electrical system component is designed as a discharge circuit, wherein the contacting device (1) is designed to temporarily electrically connect the high-voltage intermediate circuit to the discharge circuit for discharging in the event of a fault.

14. Motor vehicle with a high-voltage electrical system according to claim 12 or 13.

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