Capacitors

Abstract

The invention relates to a capacitor having a capacitor cup, which comprises a cup wall and a cup bottom, wherein the cup bottom deforms when the internal pressure rises above a set value, and this deformation can be detected by a sensor device. For this purpose, the sensor device is operatively connected to the bottom outer side of the cup bottom. The sensor device is designed as a plate-shaped switching device in the form of a hinged tongue formed on a base body, and the conductor path located on the base body is disconnected when the tongue is deflected.

Description

Technical Field

[0001] The present invention relates to a capacitor. Background Art

[0002] A capacitor protection device using an electronically monitored strain gauge is previously known from DE 271 587 A1. The strain gauge is arranged on the housing of the capacitor in order to monitor the electrical and thermal state of the capacitor. The strain gauge can be glued, sewn, welded or similarly fixed during the manufacture of the capacitor.

[0003] In the arrangement for protecting power capacitors according to DE 245 975 A1, it is proposed to provide a solution which allows the capacitor to be protected by means of an optical waveguide while locating the source of the fault without destroying the capacitor. This is achieved in that, when the housing of the capacitor expands, light is switched from the incoming optical waveguide to the outgoing second optical waveguide by means of a suitable optical switch, the optical signal is converted into an electrical signal and then linked via a downstream NOT gate and AND gate in such a way that a signal for shutting down the device is generated only when the device is operating normally, but not when the optical waveguide path is interrupted or when the light source fails.

[0004] In a device including a capacitor module according to DE 10 2008 062 656 A1, it is proposed to provide a housing for accommodating a capacitor unit of the capacitor module, the housing having a capacitor chamber for accommodating the capacitor unit, the capacitor chamber being closed in a pressure-tight manner. The internal pressure of the capacitor chamber is detected by a pressure sensor in order to detect whether the capacitor unit is damaged.

[0005] In a capacitor with a protective device according to DE 10 2015 215 729 A1, in order to identify a fault state, it is proposed that the capacitor has a housing such that, in the event of a fault, the volume of the housing changes, and the change in the housing volume can be detected by the protective device. For this purpose, the variable volume is integrated into the capacitor housing by structural measures. This integration is achieved by shaping. It is also known that the pressure increase in the capacitor is used to activate the overpressure rupture protection in the event of an overload that causes a corresponding pressure increase. Here, when gas is formed inside the capacitor cup, the terminals of the capacitor move, thereby triggering the rupture protection. As a result, the capacitor is separated from its voltage source. Further energy input into the capacitor is avoided and a continuous pressure increase is avoided.

[0006] Another possibility for detecting the occurrence of gas formation is to select the internal pressure of the capacitor by using an overpressure switch inside the capacitor. This selection detects the situation of exceeding the expected internal pressure value and ensures that an error message or shutdown is implemented.

[0007] Overvoltage switches or corresponding sensors within the capacitor, like the internally located burst protection device, involve impedance problems and are labor intensive to manufacture and thus require higher costs.

[0008] In DE 10 2019 105 452 A1, an improved cylindrical capacitor cup and a capacitor having such a capacitor cup are proposed, which are designed so that an overvoltage in the capacitor can be detected particularly easily using an external sensor device or an external switching device and can be used to evaluate a fault state of the capacitor or to shut down the capacitor.

[0009] The capacitor cup is designed in such a way that the position of the capacitor winding in the cup and thus the position of the connectors, terminal parts and the like associated therewith does not change even when the pressure increases. This results in a defined state, in particular with regard to the impedance. In the solution according to DE 10 2019 105 452 A1, the cup bottom deforms when the pressure inside the cup increases, and this deformation can be detected by means of a sensor device arranged outside the capacitor.

[0010] The sensor device is designed, for example, as a switch which is in operative connection with the outer side of the base.

[0011] However, the sensor device can also be an optical scanning device which responds to deformations of the cup bottom. Summary of the invention

[0012] Based on the above, the object of the present invention is to provide an improved capacitor with a particularly cylindrical capacitor cup which, without any disadvantageous changes to the internal structure or the arrangement of the capacitor winding in the cup, ensures reliable signaling of the fault or shutdown of the relevant capacitor in the event of a fault state leading to an increase in pressure in the cup.

[0013] Such a shut-off device should also be retrofittable and does not have to be connected to the actual capacitor circuit. The solution to be realized should allow use in rail technology, in particular in accordance with IEC 61071 and IEC 61881, of capacitors, in particular in power electronics applications, but also in the field of rail technology. Furthermore, this embodiment is sufficient for mechanical loads in accordance with IEC standard 61373.

[0014] This object is achieved by a capacitor according to the invention having a substantially cylindrical capacitor cup comprising a cup module and a cup bottom which deforms when the pressure rises above a set value.

[0015] Starting from a capacitor according to the prior art with a capacitor cup, which comprises a cup wall and a cup bottom, which cup bottom deforms when the internal pressure rises above a set value, and this deformation can be detected by means of a sensor device and for this purpose the sensor device is operatively connected to the bottom outer side of the cup bottom. According to the invention, the sensor device is designed as a plate-shaped switching device and is arranged at a distance from the bottom outer side and can be connected to the capacitor cup.

[0016] The plate-shaped switching device comprises an electrically insulating base body, for example a conventional printed circuit board base body, on which a plurality of electrical conductor tracks are arranged, which lead to connection points.

[0017] The terminal points may be designed as terminal posts, welding terminal points or the like.

[0018] Furthermore, according to the invention, the base body has a slot-like opening or a slot-like recess for forming at least one hinge-like tongue.

[0019] At least one of the conductor paths runs through the predetermined breaking section of the tongue, so that when the tongue is deflected, the associated conductor path is disconnected and the circuit formed with the connection point is interrupted.

[0020] That is, the deformed outer side of the base or the projection of the base body with the hinged tongue located therein comes into mechanical contact when internal pressure occurs. In this case, the tongue is deflected out of its flat initial position. This deflection destroys the corresponding conductor path or paths and leads to the disconnection of the corresponding circuit, whereby a fault state of the corresponding capacitor can be signaled.

[0021] The corresponding conductor tracks can be formed from the copper-clad material of the printed circuit board.

[0022] In order to establish an operational connection between the bottom outer side of the cup bottom and the at least one hinged tongue, a pin-shaped or nail-shaped protrusion extends from the bottom outer side of the cup bottom in the direction of the tongue of the plate-shaped base, and the protrusion applies an operating force to the tongue when the internal pressure increases.

[0023] The pin-shaped or nail-shaped projection can be designed to be molded onto the cup bottom or connected to the cup bottom, for example, as a rivet.

[0024] Furthermore, in a configuration according to the present invention, the projection is configured as a local protrusion from the cup circumferential wall toward the cup bottom.

[0025] The projection serves, on the one hand, to fix the plate-shaped switching device.

[0026] On the other hand, the protrusion may have a pin-type fixing structure.

[0027] The fastening structure hereby makes it possible to hold the plate-shaped switching device and / or to fasten the capacitor, for example, to a carrier or housing section of a corresponding electrical component.

[0028] The pin-like fixing structure defines a triangle, for example. The base body of the plate-shaped switching device has a triangular shape, for example, and the triangular switching device or the base body formed in this way can be fixed at the corner points of the triangle by means of the pin-like fixing structure.

[0029] In the center of the base body, a slot-shaped opening or recess has, for example, an H-shaped form in order to form two hinge-like tongues.

[0030] In this embodiment, the conductor tracks extend over the connecting sections of the sides of the H-shape.

[0031] The conductor can have a geometrical constriction in the region of the connecting section, ie, can have reduced dimensions relative to the conductor width or conductor thickness.

[0032] The connecting edge of H does not completely form the opening.

[0033] In a preferred embodiment, the base body remains beneath the conductor track in the connecting section.

[0034] This prevents undesired deflection of the tongue when mechanical loads, in particular vibrations, occur when the capacitor is used in relatively harsh environments, which could lead to undesired damage or disconnection of the conductor path.

[0035] On the other hand, the matrix material remaining below the conductor tracks is less stable, so that the force components occurring as a result of the bulging of the capacitor cup bottom are sufficient to move the corresponding tongues in the desired manner and ensure reliable separation of the conductor tracks.

[0036] In the area of ​​the base body on both sides of the connecting section of the H and substantially within the base body surface enclosed by the H shape, further openings are provided in order to form a defined hinge axis of the respective hinge-like tongue.

[0037] According to one embodiment of the invention, the further opening is designed such that it has a substantially, but not necessarily, U-shaped or V-shaped shape, the opening of which is oriented toward the connecting section. With regard to the shape and design of the opening, for example also as a linear slot, it is important that a defined hinge is formed for realizing the desired movement of the associated tongue. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be described in detail below with reference to the embodiments and the accompanying drawings.

[0039] here:

[0040] Figure 1 A perspective view of the underside of a cylindrical capacitor fastened to a carrier, with a view of the underside of the plate-shaped switching device with the connection points; and

[0041] Figure 2 The detail view of the bottom side of a plate-shaped switching device shows details of the slot-shaped openings or recesses formed in the base body together with an exemplary distribution of electrical conductor paths which can be disconnected by hinge-like tongues when the internal pressure in the capacitor increases. DETAILED DESCRIPTION

[0042] exist Figure 1 The capacitor shown in the middle part includes a cup peripheral wall 1 and a cup bottom 2.

[0043] Inside the cup wall, that is to say inside the capacitor cup, an arrangement is provided which includes one or more capacitor windings which are electrically interconnected and connected to terminal fittings (not shown) located on the upper side of the capacitor cup.

[0044] The cup bottom 2 of the capacitor deforms when the internal pressure rises above a set value. This deformation can be detected by a sensor device.

[0045] For this purpose, the sensor device is operatively connected to the bottom outer side of the cup bottom 2 .

[0046] The sensor device is designed as a plate-shaped switching device and is arranged at a distance from the bottom outer side or cup bottom 2 and can be connected to the capacitor cup via a bolt-like fastening 3 .

[0047] The plate-shaped switching device comprises an electrically insulating base body 4 , on which a plurality of electrical conductor tracks 5 are arranged, which lead to electrical connection points 6 .

[0048] The base body 4 has a slot-like opening or recess 7 for forming at least one hinge-like tongue 8 .

[0049] At least one of the conductor paths 5 runs over a predetermined breaking section 9 of the tongue 8. This has the effect that, when the tongue 8 is deflected, the associated conductor path 10 is disconnected and the circuit formed with the connection point 6 is interrupted.

[0050] A pin-shaped or nail-shaped protrusion 11 extends from the bottom outer side of the cup bottom 3 toward the tongue 8 of the plate-shaped base body 4, and the protrusion is directed toward the inner surface when the internal pressure increases. Figure 2 The operating force is exerted on the two tongues 8 shown in FIG.

[0051] The entire arrangement can be fixed to the carrier 12 by means of the already mentioned pin-like fixing structure 3 .

[0052] The pin-like fastening structure 3 defines, for example, a triangle. According to the embodiment shown, the plate-shaped switching device or the base body has a triangular shape.

[0053] The slot-shaped opening or recess 7 is located in the center of the base body 4 .

[0054] The through hole or the gap is formed into an H-shape, for example, so as to form the two hinge-like tongues 8 .

[0055] The conductor line 10 extends through the connecting section 71 of the side of the H shape. Figure 2 As shown, the connecting section 71 is not completely designed as a through-opening, but rather a part of the base body 4 remains below the conductor path in the connecting section 71 .

[0056] On the other hand, however, the base body 4 has a weakened region 72 beneath the conductor track 7 in the connecting section 71 and / or directly in the vicinity of the connecting section. This can be realized, for example, in the form of a groove.

[0057] On both sides of the connecting section 71 on the base body 4 and substantially in the region above the base body surface enclosed by H, further openings or recesses 14 are provided in order to form a defined hinge axis for the respective hinge tongue 8 .

[0058] The further passage 14 has a rectilinear or substantially U-shaped or V-shaped shape, the opening of which is oriented toward the connecting section 71 .

[0059] The conductor paths 5 or 10 are formed on the base body 4 between the connection points 6 so that different sensor devices can be connected in different ways in series or in parallel in order to detect fault states. The sensor device formed as a switching device can thus be used more widely.

[0060] For the base body, a circuit board material commonly found on the market can be used. The openings or recesses 7 can be realized by milling or punching. The conductor tracks are structured or formed using known etching techniques.

[0061] The pin-shaped or nail-shaped protrusion 11 extending from the bottom outer side of the cup bottom 3 toward the tongue 8 of the plate-shaped base 4 is arranged according to Figure 1 and 2 In the exemplary embodiment shown, the connecting section 71 is contacted approximately centrally in order to deflect the two tongues 8 accordingly, so that a secure closing can be achieved or an indication signal can be provided.

Claims

1. A capacitor, comprising a capacitor cup, the capacitor cup comprising a cup peripheral wall (1) and a cup bottom (2), the cup bottom (2) deforming when the internal pressure rises above a set value, the deformation being detectable by a sensor device and for this purpose the sensor device being operatively connected to the bottom outer side of the cup bottom (2), characterized in that: The sensor device is configured as a plate-shaped switching device and is arranged to be spaced apart from the outside of the bottom and to be connectable to a capacitor cup. The plate-shaped switching device comprises an electrically insulating base body (4) on which a plurality of electrical conductor lines (5; 10) are arranged, which lead to electrical connection points (6). Furthermore, the base body (4) has a slot-shaped opening or gap (7) for forming at least one hinged tongue (8), at least one of the conductor lines (5; 10) being distributed on a predetermined breaking section (9) of the tongue (8), so that when the tongue (8) is deflected, the relevant conductor line (10) is disconnected and the circuit formed by the connection point (6) is interrupted.

2. The capacitor according to claim 1, characterized in that A pin-shaped or nail-shaped protrusion (11) extends from the bottom outer side of the cup bottom (2) toward the tongue (8) of the plate-shaped base body (4), and the protrusion exerts an operating force on the tongue when the internal pressure increases.

3. The capacitor according to claim 1, characterized in that The projection for fixing the plate-shaped switching device extends from the cup circumferential wall (1) in the direction of the cup bottom (2).

4. The capacitor according to claim 3, characterized in that The projection has a pin-like fixing structure (3) which is used to hold the plate-shaped switching device and / or to fix the capacitor on a carrier (12).

5. The capacitor according to claim 4, characterized in that The pin-like fixing structure (3) defines a surface, and the base body (4) of the plate-shaped switching device is adapted to this surface.

6. The capacitor according to any one of claims 1 to 5, characterized in that: In the center of the base body (4), a slot-shaped opening or recess (7) has an H-shaped form to form two hinge-like tongues (8), and the conductor tracks (10) are distributed on the connecting sections (71) of the sides of the H-shape.

7. The capacitor according to claim 6, characterized in that The connecting section (71) is not designed completely as a through-opening, but rather the base body beneath the conductor path (10) remains in the connecting section.

8. The capacitor according to claim 7, characterized in that In the connecting section (71) and / or directly in the vicinity of the connecting section, the base body (4) below the conductor track (10) has a weakened section (72).

9. The capacitor according to claim 6, characterized in that Further openings (14) are provided on the base body (4) in areas on both sides of the connecting section (71) and substantially within the base body surface enclosed by the H-shape in order to form a defined hinge axis of the corresponding hinge-like tongue (8).

10. The capacitor according to claim 9, characterized in that The further passage (14) has a substantially U-shaped or V-shaped shape, the opening of the U or V being oriented toward the connecting section (71).

11. The capacitor according to any one of claims 1 to 5, characterized in that: In the center of the base body (4), the slot-like opening or recess has a cross-shaped or triangular shape to form at least one hinge-like tongue (8).

Images