A circuit breaker device

Abstract

A circuit breaker device has a main conductor (18) which can be disconnected by a pyrotechnically driven cutting piston and also has a safety conductor (1) which is at least temporarily connected in parallel. In the event of the cutting piston being triggered, the safety conductor (1) is also cut at at least one cutting point (3a-3d) by at least one cutting element (6a-6d). According to the invention, the safety conductor (1) is arranged in a safety module (12) which is completely closed and has at least one predetermined breaking point (17). In this way, penetration of water vapor into the safety conductor (1) is reliably prevented. Preferably, the safety module (12) has a central cavity (24) around which the safety conductor (1) is arranged. The cutting elements (6a-6d) are molded on the safety conductor (1), these elements having inclined surfaces (7a-7d). By applying stress to the predetermined breaking point (17), the element (16) can be broken, which element then acts on the inclined surfaces (7a-7d) of the cutting elements (6a-6d), causing the cutting elements to be displaced outward, in turn causing the safety conductor (1) to tear.

Description

Technical Field

[0001] The present invention relates to a circuit breaker device having a main body that can be disconnected by a pyrotechnically driven cutting piston, and the circuit breaker device having a safety conductor that is connected in parallel at least temporarily, and which can be cut at at least one cutting point by at least one cutting element when the cutting piston is triggered. Background Technology

[0002] Pyrotechnic circuit breakers for electric vehicles are used to reliably interrupt current in the event of an accident or short circuit, which may also occur during charging. The basic principle, as described in WO 2022 / 011410 A1, involves a pyrotechnically driven cutting piston that knocks a central component (the so-called ejector plate) out of a solid conductor (also known as the busbar, hereinafter referred to as the main conductor). Alternatively, the main conductor can be cut off at a single point. The problem is that the resulting electric arc can have a significant impact on the external environment. Especially when charging electric vehicles, the energy that the arc must dissipate is very high due to the high charging current and high line inductance.

[0003] Therefore, it is recommended to connect the safety device in parallel to the main conductor, with the fuse conductor of the main conductor embedded in the sand. AT527248 A1 is an example. However, the energy that a single safety device can absorb is also limited. Furthermore, in this design, multiple fuses connected in series would occupy a significant amount of space.

[0004] Therefore, in AT 527218 A4, it is recommended that the fuse conductor be arranged outside the central cavity of the cut-off piston and around the cavity, such that the fuse conductor bends around the longitudinal axis of the cavity. This allows for the space-saving accommodation of a relatively long fuse conductor with multiple cut-off points (five cut-off points in the embodiment shown herein).

[0005] The fuse conductor interrupts the current by melting at the breaking point. This process, though brief, does take some time, particularly a considerable amount of time for a large enough gap to form between the breaking points to extinguish the arc. Furthermore, for permanently parallel fuse conductors, if a circuit breaker is triggered for preventative purposes during an accident but no short circuit occurs, the circuit will not be broken because the main conductor is disconnected, but the fuse conductor remains intact.

[0006] Therefore, some have suggested mechanically disconnecting the fuse conductor at the cut-off point, as illustrated in Figures 48 and 49 of WO 2020 / 204154 A1. However, this solution requires significant space in the z-direction and allows for a maximum of two cut-off points.

[0007] Therefore, in the earlier Austrian patent application A50936 / 2024, a method was proposed to improve the above-mentioned AT527218 A4 solution, namely, to provide cutting elements that move radially outward when the circuit breaker device is triggered, thereby mechanically disconnecting the fuse conductor at the cutting point.

[0008] One problem that has not yet been satisfactorily resolved is the sealing of the circuit breaker assembly in the conductor area. Water infiltration is harmful because water evaporates when an electric arc occurs, leading to extremely high internal pressure that could cause the casing to burst. Summary of the Invention

[0009] Therefore, according to the present invention, the fuse conductor is disposed within a fuse module, which is fully enclosed and has at least one predetermined break point. Moisture can be prevented from entering the fuse module by sealing the conductor end of the fuse conductor with the connection surface between the lower part of the fuse module and the cover using a sealant (e.g., silicone).

[0010] If the conductor end of the fuse conductor is folded, there is also a seal (e.g., silicone) or connection (ultrasonic welding) between the two folded surfaces of the conductor end of the fuse conductor in the area passing through the cover plate. This is consistent with known methods of manufacturing conventional fuse modules. Conversely, to break the fuse conductor, movement must be guided into the fuse module without compromising its seal during normal operation of the circuit breaker device. This is achieved through a predetermined break point in the fuse module housing.

[0011] If the fuse module's housing is made of plastic or other electrically insulating materials (such as ceramic), the insulation wiring of the fuse conductor will be greatly simplified.

[0012] This invention is particularly applicable to situations where the fuse module has a central cavity in which the fuse conductors are arranged around the central cavity, as described by the applicant Astotec in the aforementioned Austrian patent application A50936 / 2024.

[0013] In this configuration, the conductor end of the fuse conductor located near the main conductor is particularly likely to extend from the fuse module. This allows almost the entire circumference to be used as the fuse conductor. The connection point is at an angle to the end of the main conductor.

[0014] It is highly advantageous if the fuse conductor has a weak point at or near the break point, for example, through a trapezoidal recess. These weak points have two advantages: first, the mechanical stability is reduced, thus requiring less force for the mechanical breaking process; second, in the event of a short circuit, the fuse conductor melts at these weak points, thereby increasing the distance and making it easier to extinguish the arc.

[0015] The housing, fuse conductor, and cover constitute the safety module, which is easy to operate after being filled with sand and the filling port is sealed. Ideally, the fuse conductor should be laid in the sand bed, at least in the weakest areas, because the arc extinguishes more quickly in the sand layer.

[0016] Importantly, the cutting element must be easily movable, meaning there is no sand in the direction of its movement. Therefore, this area must be separated from the sand bed. Furthermore, to minimize installation space, it is preferable that at least a portion of the disconnected fuse conductor is outside the sand bed after the circuit breaker is triggered. At least the portion inside the cutting element is separated and moved to the area defined by the sand bed. This measure saves installation space if the defined area is close to the original position of the fuse conductor, but it results in the disconnection not being fully achieved on the sand bed. Results show that the disconnection efficiency is hardly reduced as a result.

[0017] The predetermined break point is preferably located on the cover of the fuse module, and particularly preferably has a closed profile. This allows at least one element to break by applying stress to the predetermined break point. The element can then be moved into the fuse module, and this movement subsequently causes the fuse conductor to separate at least at one point. An example is shown of a breaking element with a generally cylindrical outer surface that acts on the inclined surface of at least one cutting element, and disconnects the fuse conductor by the resulting movement of the cutting element. In this case, the fuse conductor is indirectly disconnected by the breakable element. However, direct disconnection is also conceivable, for example in arrangements similar to WO 2020 / 204154 A1 described above.

[0018] It is advantageous if at least one cutting element is injection molded onto the fuse conductor, or if the fuse conductor is overmolded by at least one cutting element. This allows the fuse conductor, along with positioning, disconnecting, and insulating elements, to be introduced into the fuse module housing in a single step. This greatly simplifies the assembly process and reduces the possibility of installation errors.

[0019] Since the cutting elements are connected to the fuse conductor via injection molding or overmolding, they do not require separate installation; they automatically move to the correct position when the fuse conductor is inserted. Furthermore, since the cutting elements were already manufactured using injection molding prior to this invention, there is virtually no additional cost.

[0020] If at least one cutting element is fixedly connected to the safety conductor, it can also serve as a tangential positioning element, meaning that the safety conductor cannot move tangentially even during use. This can be achieved, for example, by creating small holes in the safety conductor, which are then filled with the plastic of the cutting element during the overmolding process. If the cutting element has a starting position locking function, it can also serve as a radial positioning element.

[0021] In addition to separating elements or as an alternative to cutting elements, insulating elements can be molded onto the conductor ends of the fuse conductor via injection molding, or the fuse conductor can be overmolded with insulating elements, and / or positioning elements can be molded onto the fuse conductor via injection molding, or the fuse conductor can be overmolded with positioning elements. In the latter case, it is advantageous if the positioning element has at least one recess. Therefore, during injection molding, cuts / recesses can be formed at or through the edge of the positioning element, typically substantially parallel to the fuse conductor in that area. These cuts and recesses prevent separation of adjacent sand chambers on both sides of the positioning element and allow adjacent sand chambers to be filled with arc-extinguishing sand simultaneously. If the fuse conductor has an opening in the positioning element area, the positioning element not only functions radially but also acts as a fixing element, particularly during mechanical disconnection, preventing tangential tension on the fuse conductor. These positioning elements prevent environmental factors from causing unnecessary stress on the fuse conductor. Cutting elements can also serve as additional positioning elements for the fuse conductor.

[0022] Importantly, no electric arc can occur elsewhere. Therefore, the other dependent claims explained at the end of the description of the drawings relate to the cross-section of the fuse conductor or the material thickness of certain areas. Attached Figure Description

[0023] The present invention will now be described in more detail with reference to the accompanying drawings.

[0024] Figure 1 A front view of an exemplary fuse conductor is shown before the molding and cutting element is produced; Figure 2 An oblique view of a fuse conductor with a molded cut-off element is shown; Figure 3 A perspective view of this safety conductor is shown, on which positioning and insulating elements are also molded. Figure 4 A top view of the fuse conductor in a bent state is shown; Figure 5 A top view of the fuse conductor at the bottom of the fuse module is shown, with its cover removed; Figure 6 An enlarged cross-sectional view of the lid is shown; Figure 7 It shows Figure 5 A perspective view of the lower part, showing the cover already installed; Figure 8 The case with an additional dominant element is shown; Figure 9 This illustrates the electrical contact at the conductor ends of the fuse conductor.

[0025] List of reference numerals in the attached diagram: 1. Fuse Conductor 2a, 2b Conductor ends 3a-3d Cutting points of the fuse conductor 4a-4c Support Area 5a-5h Weak points in the fuse conductor 5a' conductor 6a-6d Cut-off elements 7a-7d Inclined surfaces on the cutting element 8a-8c Positioning elements 9a, 9b Insulating elements 10a-10c Recesses on insulating elements 11. Lower part of the insurance module 12 Insurance Module 13. Cover of the safety module Holes on the 14a-14d fuse module 15a-15h Capping 16. Components on the lid 17. Predetermined fracture point 18 Dominant Entity 19. Holes on the main body 20. Pins on the cover of the safety module 21. Reduced transverse cross-section of the main body 22 film developed 23. Break through the notch on the film. 24. Central cavity. Detailed Implementation

[0026] Figure 1 The fuse conductor 1 has two conductor ends 2a and 2b, which serve as contact portions, four cutting points 3a-3d, and three support regions 4a-4c. In this example, the cross-sections of the conductor ends 2a and 2b can be doubled by extending the dotted line of the bent metal plate. Between the aforementioned cutting points 3a-3d and the support regions 4a-4c, in this example, there are weak portions 5a-5h of the fuse conductor 1. In the embodiment shown in the figure, the weak portions 5a-5h are trapezoidal, with the thinnest cross-section facing the cutting points 3a-3d.

[0027] Figure 2 A perspective view of a fuse conductor with molded cutting elements 6a-6d is shown. These cutting elements 6a-6d are partially located at the front and partially at the rear of the fuse conductor 1. Both portions of the cutting elements 6a-6d shown here are connected by holes in the fuse conductor 1, located in the area of ​​cutting points 3a-3d. It can be seen that the inclined surfaces 7a-7d are used to drive the cutting elements 6a-6d in the circuit breaker assembly, a point that will be explained further below.

[0028] like Figure 3 As shown, the safety conductor 1 is shown in a perspective view, on which three positioning elements 8a-8c and two insulating elements 9a, 9b are additionally molded. Recesses 10a-10c in the positioning elements 8a-8c can also be seen; these recesses ensure connection between adjacent sand chambers during subsequent construction.

[0029] Figure 4 A fuse conductor 1 in a bent state is shown, which has molded cutting elements 6a-6d, positioning elements 8a-8c, and insulating elements 9a, 9b. The fuse conductor 1 is basically bent into a circle, and the conductor ends 2a, 2b are bent into directions that facilitate further installation.

[0030] Figure 5 The safety conductor 1 is shown, which has molded cutting elements 6a-6d, positioning elements 8a-8c, and insulating elements 9a, 9b, and is in a bent state in the lower part 11 of the safety module 12 (see Figure 7-). Figure 9 Fuse conductor 1 (see) Figure 5 The cutting elements 6a-6d and positioning elements 8a-8c are positioned in the lower part 11. The central cavity 24 of the lower part 11 is clearly visible, and the inclined surfaces 7a-7d of the cutting elements 6a-6d extend into the central cavity 24.

[0031] Figure 6 The lower part 11 of the insurance module 12 is shown (see Figure 7-9 A cross-sectional view of the lid 13. In the middle of the lid 13 (see...) Figure 6 There is a central element 16 that is connected to the rest of the cover 13 via a predetermined circumferential break point 17. When the central element 16 is subjected to pressure, it separates from the rest of the cover 13 and enters the central cavity 24 of the lower part 11 (see...). Figure 5 ).

[0032] Figure 7 An exemplary structure of a safety module 12 is shown, comprising a lower portion 11 and a connected cover 13. Conductor ends 2a and 2b extend from the cover 13 of the safety module 12. Holes 14a-14d are used to secure the safety module 12 to the drive unit by screws, as described below. The positions of holes 14a-14d are understood as illustrative only; those skilled in the art will clearly be able to further increase the distance between holes 14a-14d and conductor ends 2a and 2b, and to provide additional insulating elements. Additionally, caps 15a-15g are shown for sealing openings into the safety module 12 for filling with sand. They function similarly to plugs, for example, by ultrasonic welding to the cover 13 of the safety module 12.

[0033] Figure 8A safety module 12 with a main body 18 is shown. The main body 18 passes through a hole 19 via a pin 20 (see also). Figure 6 It is positioned and fixed on the cover 13 of the safety module 12, and other fixing elements may be located in, for example, the area of ​​the reduced cross section 21 of the main body 18.

[0034] Figure 9 A safety module 12 is shown, having a main body 18 and bent conductor ends 2a, 2b of a safety conductor 1. These conductor ends 2a, 2b are electrically connected to the main body 18 in overlapping areas, for example by ultrasonic welding or by additional connecting elements (screws). As previously described, the sand-filled safety module 12 serves as a fuse, and in this example, it is permanently connected in parallel with the main body 18. The safety module 12 can interact with a drive unit that is essentially identical to the housing top 8 and cover plate 12 of WO 2022 / 011410 A1 (reference numerals 8 and 12 refer to this document); that is, conversely, the housing bottom 10 in this document is replaced by the safety module 12, as shown. The drive unit has a central cavity that is aligned with the central cavity 24 of the safety module 12 (see Figure 5) (see Figure 9). Within the central cavity of the drive unit is a cut-off piston that can be driven by an igniter. During ignition, the piston is cut off along notch 23, separating the ejector plate 22 from the main body 18, similar to the situation described in WO 2022 / 011410 A1, and then the element 16 (see Figure 6 Remove it from cover 13 and move it into safety module 12 (see Figures 7-9 The central cavity 24 (see) Figure 5 )middle.

[0035] The sand-filled safety module 12 serves as a safety device. Component 16 (see...) Figure 6 The motion of ) is through inclined surfaces 7a-7d (see Figure 2 , Figure 3 and Figure 5 ) is transmitted to the cutting elements 6a-6d (see Figure 5 This causes the cutting elements 6a-6d to move radially outward and disconnect the fuse conductor 1. The arc that occurs here is extinguished by stretching (due to the further movement of the cutting elements 6a-6d) and cooling (the arc comes into contact with the arc-quenching sand). Under high current, the fuse conductor 1 burns out in the weak section 5a-5h region (see...). Figures 1-3 This causes the arc to be further elongated in the sand layer. The broken parts of the fuse conductor 1 move outward with the cutting elements 6a-6d, so depending on the structure, they may also move outside the sand bed, so the arc can only run partially in the sand.

[0036] In this example, the fuse conductor 1 is initially located in a sand bed that supports its fracture. The effect can be further improved by connecting the conductor bundle at the point where the cross-section of the weak points 5a-5h is reduced. This connection can be achieved by welding the wire 5a', for example, as... Figure 1 As shown, in the region of the weak point 5a, such a conductor 5a' hardly changes the resistance, but significantly increases the mechanical resistance, thereby pushing the fuse conductor 1 radially outward into the sand.

[0037] Importantly, any arcing occurs only in the weak section 5a-5h initially located on the sand bed. Therefore, it is crucial that the reduction in the cross-section of the fuse conductor 1 caused by the holes in the cutting points 3a-3d and the support regions 4a-4c is less than the reduction in the cross-section of the fuse conductor 1 caused by the cut in the weak section 5a-5h; or in other words, the cross-sectional area of ​​the fuse conductor 1 at the cutting points 3a-3d and the support regions 4a-4c should be greater than the cross-sectional area at the weak section 5a-5h.

[0038] By increasing the thickness of the fuse conductor 1, the cross-sectional area of ​​the cutting points 3a-3d, the support areas 4a-4c, and the conductor ends 2a and 2b can be increased. This can be achieved by initially having the fuse conductor 1 with corresponding strips (such as...). Figure 1 (As shown by the dotted line in the image) protrudes outwards and then folds into the corresponding area to achieve this. Here, firstly, a good electrical connection is not required between the folded strip and the folded area, because if a short circuit occurs, any existing gaps will form an electric arc, leading to automatic welding or contact. However, metal reinforcements can also be welded, for example, using ultrasonic welding to increase thickness.

Claims

1. A circuit breaker device having a main body (18) capable of being disconnected by a pyrotechnically driven cut-off piston, and having a safety conductor (1) at least temporarily connected in parallel with the main body, the safety conductor being capable of being disconnected by at least one cut-off element (6a-6d) upon release of the cut-off piston, characterized in that, The safety conductor (1) is disposed inside the safety module (12), which is fully enclosed and has at least one predetermined break point (17).

2. The circuit breaker device according to claim 1, characterized in that, The housing of the fuse module (12) is made of plastic or other electrically insulating materials, such as ceramic.

3. The circuit breaker device according to claim 1 or 2, characterized in that, The insurance module (12) has a central cavity (24).

4. The circuit breaker device according to claim 3, characterized in that, The safety conductor (1) is arranged around the central cavity (24).

5. The circuit breaker device according to any one of claims 1 to 4, characterized in that, The conductor ends (2a, 2b) of the fuse conductor near the main body (18) protrude from the fuse module (12).

6. The circuit breaker device according to any one of claims 1 to 5, characterized in that, The safety conductor (1) has a weak section (5a-5h) at or adjacent to the cut point (3a-3d), for example, through a trapezoidal recess.

7. The circuit breaker device according to claim 6, characterized in that, The safety conductor (1) extends into the sand bed at least in the area of ​​the weak part (5a-5h).

8. The circuit breaker device according to claim 7, characterized in that, After the circuit breaker device is triggered, at least one disconnected portion of the fuse conductor (1) is located outside the sand bed.

9. The circuit breaker device according to any one of claims 1 to 8, characterized in that, At least one fractured element (16) is capable of fracture by applying stress to a predetermined fracture point (17).

10. The circuit breaker device according to claim 9, characterized in that, The fractured element (16) has a generally cylindrical outer surface.

11. The circuit breaker device according to claim 9 or 10, characterized in that, The insulated conductor (1) can be directly cut by the breakable element (16).

12. The circuit breaker device according to claim 9 or 10, characterized in that, The safety conductor (1) can be indirectly cut via at least one cutting element (6a-6d) through a breakable element (16).

13. The circuit breaker device according to any one of claims 1 to 12, characterized in that, The at least one cutting element (6a-6d) is formed onto the fuse conductor (1) by injection molding, or the fuse conductor (1) is covered by the at least one cutting element (6a-6d).

14. The circuit breaker device according to any one of claims 1 to 13, characterized in that, At least one cutting element (6a-6d) is fixedly connected to the fuse conductor (1).

15. The circuit breaker device according to any one of claims 1 to 14, characterized in that, The insulating elements (9a, 9b) are respectively molded onto the conductor ends (2a, 2b) of the fuse conductor (1) by injection molding, or the fuse conductor (1) is covered by the insulating elements (9a, 9b).

16. The circuit breaker device according to any one of claims 1 to 15, characterized in that, At least one positioning element (8a-8c) is molded onto the fuse conductor (1) by injection molding, or the fuse conductor (1) is overmolded by the positioning element (8a-8c).

17. The circuit breaker device according to claim 16, characterized in that, The positioning element (8a-8c) has at least one recess (10a-10c).

18. The circuit breaker device according to claim 6 and 16 or 17, characterized in that, The cross-section of the safety conductor (1) in the region of one or more positioning elements (8a-8c) and / or the region of one or more cutting elements (6a-6d) is greater than the cross-section of the safety conductor (1) in the region of the weak part (5a-6h).

19. The circuit breaker device according to claim 6 and any one of claims 16 to 18, characterized in that, The material thickness of the safety conductor (1) in the positioning element (8a-8c) region is greater than the material thickness in the weak part (5a-5d) region.

20. The circuit breaker device according to any one of claims 6 and 7 to 19, characterized in that, The material thickness of the safety conductor (1) in the conductor end (2a, 2b) region and / or the cutting element (6a-6d) region is greater than the material thickness in the weak part (5a-5d) region.

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