Emergency electrical switching device with a connecting element for producing an electrically conductive connection

Abstract

The invention relates to an electrical emergency switching device with a connecting element for establishing an electrically conductive connection between two contact arrangements. The device includes an electrically controlled, pyrotechnic trigger for moving the connecting element from a standby position to an operating position. In the standby position, the contact arrangements are electrically isolated from one another. In the operating position, the contact arrangements are electrically connected to one another by the connecting element, such that the connecting element makes contact with the contact arrangements. The trigger, the connecting element, and the contact arrangements are arranged in a housing, preferably one that is dust- and liquid-tight.The connecting element comprises a mandrel aligned in one direction of movement, and the contact arrangements are formed on a busbar extending through the housing. Each contact arrangement includes a hole extending through the busbar, the holes being coaxial with each other and aligned with the mandrel of the connecting element.

Description

[0001] The invention relates to an electrical emergency switching device according to the preamble of claim 1.

[0002] The increasing prevalence of large-capacity electric batteries, such as those used as energy storage in stationary photovoltaic systems or in batteries for electric vehicles, is accompanied by a correspondingly greater potential for danger in the event of short circuits caused by accidents. For example, firefighting efforts following a fire triggered by a traffic accident involving an electric vehicle can be hampered because firefighters could be injured by electric shocks. Even accident-related damage to the vehicle's electrical system itself can result in short-circuit currents of several thousand amperes. The resulting arcing can, in extreme cases, even lead to an explosion of the battery system. Therefore, devices have already been proposed to discharge the residual energy stored in the battery or fuel cell within a very short period.These have a short-circuit switching device that can be activated by the application of a pyrotechnic charge.

[0003] The object of the present invention was to provide an electrical emergency switching device with which an even shorter reaction time is achieved and the material usage required to create particularly well-protected electrical systems is reduced.

[0004] This problem is solved by a device and a method according to the claims.

[0005] The electrical emergency switching device according to the invention, comprising a connecting element for establishing an electrically conductive connection between at least two contact arrangements, includes an electrically controllable, pyrotechnic trigger for moving the connecting element from a standby position to an operating position, wherein in the standby position the contact arrangements are electrically isolated from each other, and wherein in the operating position the contact arrangements are electrically conductively connected to each other by the connecting element, such that a contact surface of each of the contact arrangements is touched by the connecting element.

[0006] The trigger, the connecting element, and the contact surfaces are arranged in a housing. The connecting element comprises a pin aligned in one direction of movement of the connecting element, and the contact arrangements are each formed on a busbar extending through the housing. The contact arrangements each comprise a hole extending through the busbar, the holes being coaxial with each other and aligned with the pin of the connecting element.

[0007] According to an advantageous further development of the switching device, at least three contact arrangements, each comprising a busbar, are provided.

[0008] A design in which the busbars are arranged parallel to each other is also advantageous, as this allows for a space-saving design of the switching device.

[0009] An advantageous embodiment of the switching device provides that the housing is designed with a tunnel extending through the housing, with the busbars being fixed in the tunnel.

[0010] It is also advantageous if the housing comprises a lower and an upper part, with the tunnel located between the lower and upper parts. This simplifies assembly during the manufacture of the switching device.

[0011] The design of the switching device, in which the busbars are formed with a rectangular cross-section with a width and a height, also contributes to a very compact design.

[0012] In particular, the further development of the switching device, in which an insulator is arranged between adjacent busbars, with the busbars and the insulators being arranged in a stack on top of each other, proves to be advantageous.

[0013] A design of the switching device in which the longitudinal axes of the busbars are aligned perpendicularly to the direction of movement of the connecting element has the advantage that the highest relative speed between the connecting element and the busbars is achieved when the pyrotechnic trigger is ignited.

[0014] It is also advantageous if the contact surfaces of the contacting arrangements are each formed by an inner side of the holes extending through the busbars.

[0015] The further development of the switching device is also advantageous, in which the pyrotechnic trigger is formed in the upper part of the housing and includes at least one propellant charge.

[0016] It is also advantageous if the pyrotechnic trigger includes a plug for electrically contacting the propellant charge.

[0017] According to a further development of the switching device, a piston is formed in the upper part of the housing, with the connecting element attached to the piston for moving it from the ready position to the operating position. When the propellant charge is ignited, the piston absorbs the pressure of the combustion gases and, through its precise, straight guidance, ensures the short-circuiting of the busbars within the shortest possible time.

[0018] The design of the switching device is also advantageous in which the connecting element comprises a truncated cone, wherein a value of an angle between a generatrix and a cone axis is selected from a range between 0° and 45°.

[0019] The further development, in which the shell of the truncated cone of the connecting element is formed with a ribbing, has the advantage that any oxide layers possibly present in the holes of the busbars are sheared off better when the mandrel penetrates the holes.

[0020] The design of the switching device, in which the knurling includes cutting edges that extend parallel to the generatrix of the truncated cone, exposes particularly effective, bare, metallic contact surfaces.

[0021] To better understand the invention, it is explained in more detail with reference to the following figures.

[0022] They each show, in a highly simplified, schematic representation: Fig. 1 shows an electrical emergency switching device in its assembled state in perspective; Fig. 2 shows a cross-section of the emergency switching device according to Fig. 1 Perspective view shown; Fig. 3 a second cross-section of the emergency switching device according to Fig. 1 Perspective view; Fig. 4 the emergency switching device according to Fig. 1 in exploded view; Fig. 5 a detail of the interior of the housing of the emergency switching device with a perspective view of the connecting element; Fig. 6 a bottom view of the connecting element according to Fig. 5 .

[0023] It should be noted at the outset that in the differently described embodiments, identical parts are provided with the same reference numerals or component designations, and the disclosures contained in the entire description can be applied analogously to identical parts with the same reference numerals or component designations. Furthermore, the positional designations chosen in the description, such as top, bottom, side, etc., refer to the figure directly described and illustrated, and these positional designations must be applied analogously to the new position if the position changes.

[0024] The Fig. 1Figure 1 shows an electrical emergency switching device 1 in its assembled or mounted state, shown in perspective. In this switching device 1, three busbars 2 are mounted in a housing 3. The busbars 2 are aligned parallel to each other and extend through the housing 3. That is, one end of each busbar 2 protrudes from the housing 3 on both sides. Each busbar 2 can serve as a conductor section for a phase of a power circuit. The busbars 2 preferably have a rectangular cross-section with a width 4 and a height 5. An insulator 6 is arranged between each adjacent busbar 2. The busbars 2 and the insulators 6 are thus stacked on top of each other in alternating sequence and are held together by the housing 3.

[0025] The housing 3 has a tunnel 7 extending through it, through which the arrangement of the three busbars 2 with the intermediate insulators 6 extends. The busbars 2 are thus secured in the housing 3. The tunnel 7 of the housing 3 is located between a lower housing part 8 and an upper housing part 9. It has a rectangular cross-section, dimensioned to correspond to the cross-section of the arrangement or stack of busbars 2 and insulators 6. The tunnel 7 is otherwise designed and dimensioned such that the housing 3 is connected to the busbars 2 in a dust- and liquid-tight manner. Preferably, screws 10 are provided to close the housing 3, allowing the upper housing part 9 to be fastened to the lower housing part 8.

[0026] The Fig. 2 shows a cross-section of the emergency switching device 1 according to Fig. 1The diagram shows a perspective view. Above the three superimposed busbars 2 is a connecting element 11, the position shown being a ready position of the connecting element 11. In this ready position, the connecting element 11 is located at a sufficiently large distance from the busbars 2 so that they are electrically insulated from the connecting element 11. According to this embodiment of the switching device 1, the connecting element 11 comprises a pin that is aligned in a direction of movement 12 of the connecting element 11. The upper end of the pin of the connecting element 11 is attached to a piston 13, which in turn is adjustable in the direction of movement 12 inside the upper housing 9. Above the piston 13 with the connecting element 11, a propellant charge 14 is arranged – also inside the upper housing 9.This propellant charge 14 is part of an electrically controlled pyrotechnic trigger for moving the connecting element 11 from the ready position to an operational position. The propellant charge 14 is electrically connected to a plug 15 on the outside for ignition.

[0027] Sections of the busbars 2 located inside the housing 3 are provided with contact arrangements 16. According to the embodiment of the described switching device 1, the contact arrangements 16 of the busbars 2 are each formed by a hole extending through the busbars 2. The holes of the contact arrangements 16 of the three busbars 2 are aligned coaxially with each other. The holes of the contact arrangements 16 are also aligned and arranged in a manner relative to the pin of the connecting element 11. The inner surfaces 17 of the holes of the contact arrangements 16 thus each form a contact surface of the contact arrangements 16 that can be contacted by the connecting element 11.

[0028] In the event of activation of the emergency switching device 1, the connecting element 11 is moved downwards in the direction of movement 12 into its operating position under the influence of the ignited propellant charge 14. The connecting element 11, formed by the mandrel, then comes into contact with the inner surfaces 17 of the contact arrangements 16 of all three busbars 2. The busbars 2 are thus electrically connected to each other by the connecting element 11 and therefore short-circuited. The diameter of the mandrel of the connecting element 11 and the diameter of the holes of the contact arrangements 16 are advantageously dimensioned such that any oxide layers that may be present on the contact surfaces or on the inner surfaces 17 are sheared off during the movement of the connecting element 11 into its operating position. Such shearing of oxide layers or...The remaining insulation exposes bare, metallic surfaces as effective contact surfaces, thus creating a good electrically conductive connection.

[0029] As in the Fig. 2 As shown, the insulators 6 can also span the area of ​​the contact arrangements 16 or the area of ​​the holes in the busbars 2 without interruption. Opposing side surfaces of two adjacent busbars 2 are preferably completely covered by an insulator 6. As a condition, when the connecting element 11 moves from the ready position to the operating position, the insulators 6 are pierced by the mandrel of the connecting element 11, and any remnants thereof are pushed away from the area of ​​the contact arrangements 16. Thus, the parts of the insulators 6 spanning the area of ​​the contact arrangements 16 do not constitute a significant obstruction.

[0030] The Fig. 3shows a cross-section of the emergency switching device 1 according to Fig. 1 The piston 13 with the connecting element 11 is shown in perspective. It is in its operating position. Under the influence of the pressure of the combustion gases generated after ignition of the propellant charge 14, the piston 13 moves the connecting element 11 towards the busbars 2, which are attached between the lower housing part 8 and the upper housing part 9. In doing so, the pin forming the connecting element 11 penetrates the holes of the contact arrangements 16 and comes into contact with their inner surfaces 17 ( Fig. 2) to the system. An advantage of this is that the surface pressure or contact area is increased compared to round contact pieces. This increases the switching device's performance. The emergency switching device 1 thus allows several busbars or multiple bus rails 2 to be short-circuited simultaneously. The switching device 1 can therefore be used, for example, to short-circuit the three phases of an electric vehicle motor with a very short reaction time of just a few milliseconds. For the sake of completeness, it should also be noted that alternative versions of the switching device 1 can also have only two or more bus rails 2 instead of three.

[0031] The Fig. 4Figure 1 shows an exploded view of the emergency switching device 1. To form the tunnel 7 between the lower housing part 8 and the upper housing part 9, the lower housing part 8 has a U-shaped frame section. The rectangular cross-section of the tunnel 7 is bounded at the top by the underside of the upper housing part 9. The three busbars 2 each have a hole for the contact arrangements 16. One of the flat insulators 6 is arranged between each busbar 2. The propellant charge 14 and the piston 13 with the connecting element 11 are shown below the upper housing part 9. The longitudinal axes 18 of the three busbars 2 are aligned parallel to each other in the assembled state. The direction 12 of the movement of the connecting element 11 from the ready position to the operating position and the longitudinal axes 18 of the busbars 2 are perpendicular to each other.

[0032] The Fig. 5 Figure 1 shows a detail of the interior of the housing 3 of the emergency switching device 1, with a perspective view of the connecting element 11. The piston 13 with the connecting element 11 is in its ready position. The mandrel forming the connecting element 11 has the shape of a truncated cone tapering downwards. The angle 19 of a generatrix relative to the cone axis (corresponding to the direction of movement 12) is approximately 2°. Preferably, the surface of the truncated cone of the connecting element 11 also has a knurled surface. In the event of the switching device 1 being triggered by the ignition of the propellant charge 14, the connecting element 11 is propelled at high speed into the holes of the contact arrangements 16, thereby creating an electrically conductive connection between the busbars 2.

[0033] The Fig. 6shows a view of connecting element 11 from below according to Fig. 5The knurling formed on the surface of the truncated cone of the connecting element 11 includes cutting edges 20 that extend parallel to the generatrix of the truncated cone of the connecting element 11. After the emergency switching device 1 is triggered, the connecting element 11 moves into the holes of the contact arrangements 16, whereby the cutting edges 20 of the connecting element 11 are pressed into the inner surfaces 17 of the holes of the contact arrangements 16. Any oxide layers that may be present on the inner surfaces 17 of the contact arrangements 16 can be broken up particularly effectively by the action of the cutting edges 20. The resulting plastic deformation of the material of the busbars 2 on the inner surfaces 17 leads to the formation of bare, metallic surfaces with a correspondingly large, effective contact area.In this way, a good electrical connection is ensured between the connecting element 11 and the contact arrangements 16 of the busbars 2.

[0034] The exemplary embodiments show possible embodiment variants, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiment variants, but rather various combinations of the individual embodiment variants are also possible and this possibility of variation lies within the skill of the person skilled in this technical field due to the teaching on technical action by the present invention.

[0035] The scope of protection is defined by the claims. However, the description and drawings must be consulted for the interpretation of the claims. Individual features or combinations of features from the different embodiments shown and described can, in themselves, represent independent inventive solutions. The problem underlying these independent inventive solutions can be found in the description.

[0036] All references to value ranges in this description are to be understood as encompassing any and all sub-ranges thereof, e.g., the reference 1 to 10 is to be understood as including all sub-ranges, starting from the lower limit 1 and the upper limit 10, i.e., all sub-ranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g., 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

[0037] Finally, for the sake of clarity, it should be noted that, for a better understanding of the structure, some elements have been shown not to scale and / or enlarged and / or reduced in size. Reference numeral list

[0038] 1 Switching device 2 Busbar 3 Housing 4 Width 5 Height 6 Insulator 7 Tunnel 8 Housing lower part 9 Housing upper part 10 Screw 11 Connecting element 12 Direction of movement 13 Piston 14 Propellant charge 15 Plug 16 Contact arrangement 17 Inside 18 Longitudinal side 19 Angle 20 Cutting edge

Claims

1. An electrical emergency switching device (1) comprising a connecting element (11) for establishing an electrically conductive connection between at least two contacting arrangements (16) and comprising an electrically controllable, pyrotechnic trigger for moving the connecting element (11) from a standby position to an operational position, wherein in the standby position the contacting arrangements (16) are electrically insulated from one another, and wherein in the operational position the contacting arrangements (16) are electrically conductively connected to one another by the connecting element (11) such that one contact surface of each of the contacting arrangements (16) is touched by the connecting element (11), and wherein the trigger, the connecting element (11) and the contact surfaces are arranged in a housing (3), characterized in thatthe connecting element (11) comprises a mandrel aligned in a direction of movement (12) of the connecting element (11), and in that the contacting arrangements (16) are each formed on a busbar (2) extending through the housing (3) and each comprise a hole extending through the busbar (2), wherein the holes are aligned coaxially relative to one another and in alignment relative to the mandrel of the connecting element (11).

2. Switching device (1) according to claim 1, characterized in that at least three contacting arrangements (16) each comprising a busbar (2) are formed.

3. Switching device (1) according to claim 1, characterized in that the busbars (2) are arranged parallel to each other.

4. Switching device (1) according to claim 1, characterized in thatthe housing (3) is formed with a tunnel (7) extending through the housing (3), wherein the busbars (2) are fastened in the tunnel (7).

5. Switching device (1) according to claim 1, characterized in that the housing (3) comprises a lower housing part (8) and a higher housing part (9), wherein the tunnel (7) is formed lying between the lower housing part (8) and the higher housing part (9).

6. Switching device (1) according to claim 1, characterized in that the busbars (2) are designed with a rectangular cross-section with a width (4) and a height (5).

7. Switching device (1) according to claim 1, characterized in that an insulator (6) is arranged between each adjacent busbar (2), wherein the busbars (2) and the insulators (6) are arranged one on top of the other to form a stack.

8. Switching device (1) according to claim 1, characterized in thatLongitudinal axes (18) of the busbars (2) are aligned perpendicularly relative to the direction of movement (12) of the connecting element (11).

9. Switching device (1) according to claim 1, characterized in that the contact surfaces of the contacting arrangements (16) are each formed by an inner side (17) of the holes extending through the busbars (2).

10. Switching device (1) according to claim 1, characterized in that the pyrotechnic trigger is formed in the upper housing part (17) and comprises at least one propellant charge (14).

11. Switching device (1) according to claim 1, characterized in that the pyrotechnic trigger comprises a plug (15) for electrically contacting the propellant charge (14).

12. Switching device (1) according to claim 1, characterized in that a piston (13) is formed in the upper housing part (7), wherein the connecting element (11) is fastened to the piston (13) for movement from the standby position to the use position.

13. Switching device (1) according to claim 1, characterized in that the connecting element (11) comprises a truncated cone, wherein a value of an angle (19) between a generatrix and a cone axis is selected from a range between 0° and 45°.

14. Switching device (1) according to claim 1, characterized in that a shell of the truncated cone of the connecting element (11) is formed with a corrugation.

15. Switching device (1) according to claim 1, characterized in that the serration comprises cutting edges (20) which extend parallel to the surface lines of the truncated cone.

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