DE202004018936U1 - Capacitor and capacitor module - Google Patents

Abstract

Capacitor, with a connection element (3) which is laser-welded to the capacitor (1, 2; 21) is attached.

Description

The The invention relates to a capacitor with a connection element and a capacitor module with multiple capacitors.

From the publication DE 102 18 295 A1 and from the publication DE 35 18 236 C2 Capacitor modules are known in which connection elements are provided which are screwed to a capacitor.

It The object of the present invention is to specify a capacitor which allows a low-resistance contact. It is also a task the present invention to provide a capacitor module, the characterized by a low ohmic resistance.

These Tasks are solved by a capacitor according to protection claim 1 and 17 respectively by a capacitor module according to protection claim 16 and a capacitor arrangement according to Protection claim 30. Advantageous embodiments of the capacitor are the dependent claims refer to.

According to one embodiment of the capacitor, it is provided that a capacitor is a connection element having. The connection element preferably serves for further contacting the condenser, for example, the supply of lines in which electrical currents flow can. These electric currents can be used to charge the capacitor. To the capacitor externally led lines but can also be used to discharge the capacitor, that is, the Capacitor stored therein electrical energy in the form of to remove electrical power.

According to one embodiment of the capacitor, it is provided that a connection element by means of laser welding attached to the condenser.

Preferably becomes the laser welding so performed that both a part of the connecting element and a part of the Capacitor is melted. This can be a particularly intimate Connection between the two elements can be achieved.

With Help such an intimate connection can be advantageous low contact resistance between the terminal and the capacitor be achieved.

Of Another is an intimate connection between the two elements therefore advantageous, because of it In addition, a good mechanical connection can be achieved. This means that by a suitable implementation of the laser welding a mechanically stable connection of the connection element with the capacitor can be achieved. Such a compound is particularly advantageous in capacitors, the outer mechanical Loads, for example vibrations in a motor vehicle, are exposed.

Of the indicated capacitor makes use of the idea, with the help of a Laser welding one particularly advantageous connection of a connection element to the To achieve a capacitor. The specified way of contacting is particularly suitable for electrochemical double-layer capacitors. Such capacitors are preferably in motor vehicles as an energetic cache used. By using laser welding, a connection between the connection element and the capacitor are generated, both in terms of electrical contact resistance as well as in terms the mechanical stability is advantageous.

According to one another embodiment of the capacitor, it is provided that the connection element on casing of the capacitor is attached. For example, a connection element on the lid of a cup-shaped housing be attached.

Around To achieve particularly good laser welding properties, it is advantageous if the materials of the connection element on the one hand and the capacitor or the part of the capacitor to be welded, on the other hand, are alike In particular, they can be the same Materials are used. Advantageously, aluminum used.

In many cases If the capacitor or its housing made of aluminum. In this Case, it is advantageous, even the element to be welded aluminum to choose, because the attachment of other metals or materials to aluminum difficult is.

In other cases a capacitor has a stainless steel housing. In this case is it is advantageous to weld a Stainless steel element to choose.

According to another embodiment of the capacitor, it is provided that the connection element has a thread. Such a thread can preferably be used to connect further electrical contact elements with the capacitor by screws. For example, an electrically conductive sheet or a busbar by means of a screw on a so fixed capacitor can be attached.

According to one another embodiment of the capacitor, it may be provided that the connection elements on an external connection of the capacitor is secured by laser welding. At this embodiment Thus, the capacitor has an external connection, which is used to attach another Connection elements is suitable. Such a connection element can in particular also advantageously be used for several Capacitors, each for an outside connection have, electrically conductive and also mechanically stable with each other connect to.

For laser welding between the connection element and the external connection of the capacitor is essentially that for laser welding between the connection element and capacitor itself said.

According to one another embodiment of the capacitor can be used as external connection an element can be used, which in turn is laser welded to the capacitor is attached. Such an embodiment has the advantage that the electricity transport, starting from the outside at Terminal element and ending at the capacitor itself, respectively laser welded Connections running, resulting in a particularly low electrical resistance of the capacitor guaranteed can be.

According to one another embodiment a capacitor is provided that at the connection between a connection element and the capacitor several laser welding points are formed. laser welding is a method that is particularly good for pointwise joining of two objects suitable. Usually becomes during laser welding by melting the nearby the weld located materials produced a weld point from a melt. Several such welds can spatial closely adjacent or at a slightly greater distance from each other in a contact area between the two elements to be welded be generated.

It is particularly advantageous in this context, when the area to be welded from the outside easily accessible is, so that's for the laser welding needed Thermal energy by means of a laser beam easily supplied from the outside can.

By the use of multiple laser welding points can be achieved that the electrical resistance for the transport of electricity over one Connection element into the condenser or vice versa may be low. Several adjacent laser welding points can namely as a parallel circuit of electrical resistors or as a parallel connected Rungs are considered.

According to one another embodiment a capacitor, it is provided that on a connection element another capacitor is attached.

A Such an embodiment has the advantage that several capacitors be connected together in a battery or in a module can. This connection can be made particularly low impedance, because the benefits of laser welding both in the contact of the connection element to the first as also to the second capacitor each for a low contact resistance to care.

According to one another embodiment a capacitor, it is provided that an external connection with a housing a capacitor is connected by laser welding. External connections can be, for example on lid of cup-shaped casing be attached. Such attachment is preferably by means of laser welding due to the already described above advantages in terms of contact resistance and mechanical strength of such a compound.

there conveys the external connection the connection of the usual in the capacitor capacitor winding outwards and an optionally still used connection element provides for this, that electrical currents from the outside connection of the capacitor can flow into further electrical components.

The Connection element thus also serves, for example, to a capacitor to connect with other electrical components.

According to one another embodiment a capacitor, it is provided that an external connection Part of a housing a capacitor. Such an embodiment provides an alternative to the embodiment just described that is, that in this case the external connection does not have to be connected to the housing as a separate part, but that the outside connection one piece in a part of the case can be integrated. For example, the lid of a cup-shaped housing through corresponding projections, beads or other shapes designed be that the lid itself as part of the case at the same time as an external connection to connect further electrical contact elements is suitable.

According to one another embodiment of the capacitor, it is provided that an external terminal has a projection has, which engages in a recess of a connection element. By using such a fitting of the outer terminal in a connection element can be an additional improvement of the mechanical stability be achieved.

Furthermore has such an embodiment the advantage of having a battery of several juxtaposed Capacitors each having connection elements on the upper side, by simply laying a hole having produced connecting element and subsequent laser welding becomes.

According to one another embodiment a capacitor, it is provided that a recess of the connecting element a hole is. Such a hole has the advantage of being one of Side of the connection element ago an external connection are performed can and laser welding done from the other side can.

This means that when using a hole as a recess in particular the advantage results that an external connection arranged in the hole of the. opposite Side of the connection element is accessible forth.

According to one another embodiment of the capacitor, it is provided that laser welding points are arranged along a line. This has the advantage that the laser welding can be done in an area where different elements are joined together bump, so that by purposeful positioning of a laser beam Material of both the one and material of the other element can be melted, resulting in a laser welding connection or for positioning a laser welding point with good electrical and mechanical properties. The Melt formed from the two elements can mix and thus for an intimate connection of the two elements, for example, the connection element and the capacitor or an external connection.

According to one another embodiment it is envisaged that the number of spot welds is chosen that it is adapted to a given current carrying capacity. This means that for a given current and in about prior known current carrying capacity a single spot weld the Number of spot welds so chosen that can be the desired one ampacity is achieved. For particularly large Stream, For example, here capacitor banks are given, which several Amperes can pick up or dissipate electricity, the number of spot welds 100, 200 or even 1000.

The ampacity a single spot weld adds up to the current carrying capacity of the other welding points due to the electrical parallel connection of the through the welding points flowing Streams.

The Number of spot welds depends on the required Total conductor cross section, which is the sum of single conductor cross sections individual laser welding points given is. This in turn depends on the laser power and the cross-sectional area the laser focus.

According to one another embodiment a capacitor, it is provided that an external connection a extruded part is. Have flow molded parts the advantage that they are particularly good laser weldable.

Accordingly it is particularly advantageous if a connection element a Extruded part is.

Furthermore It is advantageous if external connection and connecting element each containing aluminum.

Preferably an aluminum of purity 99.5 is used.

It but can also be another suitable material, such as stainless steel be used.

Furthermore a capacitor module is specified which contains a plurality of capacitors. The Capacitors are at least partially interconnected by a connection element, wherein the connection of the connection element to each of the capacitors connected by means of laser welding is.

A Such a procedure is particularly in capacitor modules of Advantage where multiple capacitors are connected in series. In This case adds up the contact resistance also in row. Are the contact resistance also in series with each other and add up accordingly. In such a Case it is particularly important that the contact resistance between a connection or connection element and the involved Capacitors is particularly low.

In a capacitor module, however, the capacitors can just as well be used in a parallel circuit or in a mixed series / Pa Rallelschaltung present.

Furthermore a capacitor is proposed which has at least one external connection having at least one fixing element, wherein at least one attached to the external connection Connection element is provided which has a circular recess has, in which engages the fixing element.

According to one embodiment According to the invention, the at least one fixing element engages in such a way in the connection element that, with held external connection a rotation of the capacitor is allowed around its longitudinal axis.

One Such a capacitor has the advantage of being in any orientation around its longitudinal axis can be rotated without causing the position of the connection element changed must become.

The Fixing element is preferably a projection, which at least is designed partially elastic. This can be a very safe Locking the connection element with the external connection of the capacitor be achieved.

Of the external connection can with several fixation elements in the form of protrusions of the mentioned Be kind of trained. These are preferably around concentrically a central axis arranged.

Of the Capacitor may preferably after determining one for its Application suitable orientation firmly connected to the connection element become. This is preferably done by welding and / or Soldering.

Of Furthermore, a capacitor arrangement is proposed in which a first and a second capacitor are present, wherein the first capacitor at least one formed with at least one fixing element external connection having. The connection element is at the external connection of the first capacitor and attached to the second capacitor and has at least one circular Recess, in which the fixing element of the first capacitor intervenes. Preferably, the fixing element engages in the Terminal element that a rotation of the first capacitor according to the type mentioned allows is.

Also the second capacitor may have an external connection as in the first Have capacitor, in which case the connection element two circular Having recesses, wherein in each recess, the fixing element one of the two capacitors engages. It is also preferred that a rotation of said type of second capacitor is made possible.

Together with the rotation of the capacitors around their own longitudinal axes if they are attached to the connection element, the positioning of a second capacitor to be connected to the first be freely selected along a specific arc. This is possible because the connection element can be freely rotated around both capacitors can.

in the The following will be a capacitor or a capacitor module based on embodiments and its associated Drawings closer explained.

1 shows a capacitor in a schematic cross section.

2 shows a section through the condenser 1 along the line II-II.

3 shows a capacitor module in a schematic cross section.

4 shows a section through the module 3 along the line IV-IV.

5 shows two capacitors with a position-independent connection element.

6 shows the engagement of arranged on the capacitors fixing elements in the recesses of a connection element.

elements that are the same or have the same function are with each other the same reference numerals. The figures are not to scale, but distorted due to the better representation.

1 shows a capacitor 1 , which on its outside is a housing 41 having. On top of the case 41 a recess is arranged. In the recess is a connection element 3 arranged. The connection element 3 is with a thread 5 provided, which is arranged on a pin. At the top of the case 41 , at the point where the connection element 3 and the case 41 touching each other are welding points at the transition point 6 appropriate. These welds 6 are produced by laser welding. They allow a low electrical contact resistance between the connection element 3 and the housing 41 ,

2 shows the arrangement of multiple welds 6 in a plane. It is recognizable, that the welding points are arranged along a line, wherein the distance between the welding points 6 can vary quite a bit.

The welding points can produce a low-resistance and mechanically stable connection with a sufficiently large cross-section. At the same time, a connection can be made that causes only a low heat input, so that the capacitor 1 not damaged or even destroyed. In particular, the method of laser welding can be applied to single double-layer capacitors or even to modules containing any number of interconnected single capacitors. Here an interconnection with extremely low internal resistance can be realized.

3 shows a capacitor module with a first capacitor 1 and a second capacitor 2 , On top of each capacitor 1 . 2 is an external contact 7 arranged. In the left capacitor 1 forms the external contact 7 the positive pole while in the right capacitor 2 the external contact 7 forms the negative pole. In the left capacitor 1 forms the housing 41 the negative pole of the capacitor. In the right capacitor forms the housing 42 the positive pole. Through the connection element 3 becomes the negative terminal of the right capacitor with the positive terminal of the left capacitor 1 connected. Schematically is on the left side of 3 yet another capacitor 21 shown, the negative pole is arranged on the top and its positive terminal on the housing. The housing of the capacitor 21 is with the housing of the capacitor 1 welded, so that a total of a series connection of the three capacitors 1 . 2 . 21 results. The arrangement of the poles in a capacitor can be adjusted in the case of double-layer electrolytic capacitors by a corresponding applied poling voltage.

The from the case electrically insulated first external connections are usually used to in the case located capacitors, for example in the form of capacitor films to be contacted. Capacitors are usually made two electrode layers, between which a porous separator is arranged. Both the separator and the electrode layers are in Contact with an electrolyte solution. The layer arrangements of the electrode layers and the separators can rolled up to capacitor windings.

The capacitors 1 . 2 have external connections 7 on, either by laser welding using welds 6 (See in particular the right side of the capacitor 2 ) or by other methods of attachment to the casings of the capacitors 1 respectively 2 are connected. An external connection 7 but can also be part of the housing of the capacitor itself.

The connection element has the form of a busbar, which can carry currents of a few amperes or even 10 A. The busbar points at the locations of the external connections 7 recesses 8th on in the example of 3 are executed as holes. The external connections 7 have protrusions 71 on that in the recesses 8th of the connection element 3 intervention. At the contact point between the connection element 3 and the respective lead 71 are welds 6 placed, which are made by laser welding. By means of these welds 6 is the connection element 3 with the capacitors 1 and 2 connected. The welds 6 lie on the top of the capacitor array, so that they are easily accessible from the outside and can be made by simply applying a laser beam.

4 shows the arrangement of the welding points 6 for the left capacitor 1 and for the right capacitor 2 , In the area of the left capacitor 1 are the welding points, which are the connecting element 3 with the lead 71 connect at a relatively large distance from each other, but regularly arranged. The currents passing through the welds 6 flow add up to a total current coming from the connection element 3 is transported into the condenser.

On the right side of 4 is the arrangement of the welds 6 for the second capacitor 2 to recognize. Here are the welds 6 very dense, which can be transported in this area a very high current with low resistance.

5 shows a first capacitor 1 , which by means of a connection element 3 with another, second capacitor 2 connected is. The capacitors 1 . 2 each have external connections 7 with circular cross-sections, and are designed as connecting pins. They also have one or more, partially elastic fixing elements in the form of protrusions 71 on, which are formed with flare, steps or flanges. It is advantageous if the projections have radially outwardly directed hooks at the free end, which may be sharp or abyssal.

It is possible, too, that only one fixing element is provided, which preferably at the free end a radially outwardly directed, elastic and hooks serving as hooks having. The fixing element can be used as a protruding. ring be educated.

The connecting element connecting the capacitors 3 consists of an electrically conductive metal or sheet, from the recesses 8th in the form of holes are punched out so that the outer terminals 7 the capacitors can engage in the recesses. However, it is not inevitable that holes are removed. Instead, the recesses may also be realized as circular depressions of a metal or sheet metal connector.

The intervention of the external connections 7 takes place by means of the elastic projections 71 in the manner of a snap connection. In this case, the connection element 3 or the recesses 8th in the form of holes of the connecting element on the.

Fixing element or pushed onto the projections that they yield radially inward. The connection element is pressed further until it has passed the hooks of the projections, the projections snap back into the original position and the connection element rests on a flange, a step or a flange of the projections. This is the connection element 3 Locked securely with the external connection.

It is preferred that the connection element 3 after mounting on the external connection 7 a capacitor 1 . 2 has a rotation game. Based on the rotation game, the connection element 3 be rotated in an already mounted on an external connection state, so that the position of a second capacitor 2 which is to be attached to the connection element, along a circular arc A, B can be arbitrarily selected with a certain radius. The radius is the distance between the centers of the two recesses 8th of the connection element or alternatively, if the connection element is provided with only one recess, the distance between the center of this recess and the point of contacting the connection element with a second capacitor 2 ,

Not only is a free positioning (due to the dimensions of the connection element) the capacitors relative to each other possible, but also the orientation of the capacitors themselves. A rotation of the capacitors is too then possible if the capacitors already connected to each other by means of the connecting element connected, but not yet soldered / welded. You can So each rotated in an orientation in which they, for example optimally contacted with a power rail or another connection can be.

It can be favorable as needed, the connection element 3 with only one recess 8th train in which an outside connection 7 only one capacitor 1 intervenes. Thus, the external connection of a second or further capacitor 2 be formed arbitrarily and the connection between the connection element 3 and the second capacitor 2 done in any way, for example by means of a screw or clamp connection. Thus, further capacitors with different external connection types compared to the first capacitor can advantageously be connected to the first capacitor. The possibility of free positioning of the second capacitor along. a circular arc relative to the first capacitor still exists.

The mechanical connection between the external connection 7 and the connection element 3 is preferably supplemented or strengthened by means of a compound in which the materials of the outer terminal and the connecting element merge into one another. In this case, soldering and / or welding connections are particularly favorable, in particular laser welding connections.

The mechanical connection of the connection element to the external connection by means of welding or soldering technology is preferably carried out after the desired orientations and positioning of the rotatable capacitors has taken place. Such compounds have the advantage that they are low impedance. The brazing or welding is preferably at one or more contact points between the connection element 3 and the projections 71 the external connections 7 make the capacitors.

It is preferred that at least one of the capacitors is a housing 41 having a top and a bottom or bottom side. The external connection 7 is preferably at the top of the capacitor 41 fastened, wherein on the bottom side of the housing a contactable preferably with a further capacitor busbar 3 ' can be arranged. However, it is also possible to have an external connection 7 of the type mentioned form both on the top and on the bottom side of the housing. This allows one or more capacitors also on the bottom side of a connection element 3 be attached.

6 shows how a connection element 3 with two round recesses 8th on two capacitors 1 . 2 a capacitor assembly is mounted. The outer terminals are arranged with a plurality of concentric about a central axis or a central point, protruding fixing elements 71 formed, which engage in the recesses of the connection element. At the bottom side of the capacitors are each busbars 3 ' arranged. The arrows A and B respectively show the rota tion possibility of a first capacitor 1 about its axis and the arc, along which the second capacitor 2 can be positioned.

The present invention limited not on individual capacitors and not on double-layer capacitors. It is applicable to all possible ones Capacitors and on series circuits, parallel connection and mixed interconnections of several capacitors with each other.

1, 2, 21

capacitor

3

connecting element

41 42

casing

5

thread

6

WeldingSpot

7

external connection

71

head Start

8th

recess

A, B

arc

Claims (36)

Capacitor, with a connecting element ( 3 ), which is laser-welded to the capacitor ( 1 . 2 ; 21 ) is attached. Capacitor according to Claim 1, in which the connection element ( 3 ) on the housing ( 41 . 42 ) of a capacitor ( 1 . 2 . 21 ) is attached. Capacitor according to one of Claims 1 or 2, in which the connecting element ( 3 ) a thread ( 5 ) having. Capacitor according to Claim 1, in which the connection element ( 3 ) on an external connection ( 7 ) of a capacitor ( 1 . 2 . 21 ) is secured by laser welding. Capacitor according to one of claims 1 to 4, wherein at the connection between a connecting element ( 3 ) and the capacitor ( 1 . 2 . 21 ) several laser welding points ( 6 ) are formed, which form parallel-connected current paths. Capacitor according to one of Claims 1 to 5, in which on the connection element ( 3 ) another capacitor ( 1 . 2 . 21 ) is attached. Capacitor according to one of Claims 4 to 6, in which an external connection ( 7 ) by means of laser welding with a housing ( 41 . 42 ) of a capacitor ( 1 . 2 . 21 ) connected is. Capacitor according to one of Claims 4 to 6, in which an external connection ( 7 ) Part of a housing ( 41 . 42 ) of a capacitor ( 1 . 2 . 21 ). Capacitor according to one of Claims 4 to 8, in which an external connection ( 7 ) a lead ( 71 ), which in a recess ( 8th ) of a connection element ( 3 ) intervenes. A capacitor according to claim 9, wherein the recess ( 8th ) of a connection element ( 3 ) is a hole. Capacitor according to one of Claims 5 to 10, in which the laser welding points ( 6 ) are arranged along a line. Capacitor according to one of Claims 5 to 11, in which the number of spot welds ( 6 ) is adapted to a given current carrying capacity. Capacitor according to one of Claims 4 to 12, in which an external connection ( 7 ) is a Fließpressteil. Capacitor according to one of Claims 1 to 13, in which a connection element ( 3 ) is a Fließpressteil. Capacitor according to one of Claims 1 to 14, in which an external connection ( 7 ) and a connection element ( 3 ) Aluminum. Capacitor module comprising a plurality of capacitors ( 1 . 2 . 21 ) according to one of claims 1 to 15, characterized by one or more connection elements ( 3 ) are interconnected in a series or parallel connection. Capacitor, comprising: - at least one with at least one fixing element ( 71 ) external connection ( 7 ), - at least one connecting element ( 3 ), which - is attached to the outer terminal, and - a circular recess ( 8th ), in which engages the fixing element. Capacitor according to Claim 17, in which the connecting element ( 3 ) by means of a welding, soldering or laser welding connection on the external connection ( 7 ) is attached. A capacitor according to claim 17, wherein the fixing element of the external connection engages in the connection element such that when held external connection a rotation of the capacitor is allowed around its longitudinal axis. Capacitor according to one of Claims 17 to 19, in which the connecting element ( 3 ) with the external connection ( 7 ) is locked. Capacitor according to one of Claims 17 to 20, in which at least a part of the fixing element ( 71 ) is elastic. Capacitor according to Claim 21, in which the elastic part of the fixing elements ( 71 ) with the connection element ( 3 ) connected is. Capacitor according to one of Claims 17 to 22, in which the fixing element ( 71 ) is a lead. Capacitor according to one of Claims 17 to 23, in which the fixing element ( 71 ) has an outwardly directed hook. Capacitor according to one of Claims 17 to 24, in which the external connection comprises a plurality of fixing elements ( 71 ) having. Capacitor according to Claim 25, in which the fixing elements ( 71 ) are arranged concentrically about a central longitudinal axis of the capacitor. Capacitor according to one of Claims 17 to 26, in which the external connection ( 7 ) on an upper side of a housing ( 41 ) of the capacitor is arranged. Capacitor according to one of Claims 17 to 27, in which a further external connection ( 7 ) on a bottom side of a housing ( 41 ) of the capacitor is arranged. Capacitor according to one of Claims 17 to 28, in which a bus bar ( 3 ' ) on the bottom side of the housing ( 41 ) is attached. Capacitor arrangement comprising: - a first and a second capacitor ( 1 . 2 ), wherein the first capacitor ( 1 ) at least one with at least one fixing element ( 71 ) external connection ( 7 ), - at least one connecting element ( 3 ), which - at the outer terminal of the first capacitor and the second capacitor ( 2 ), and - at least one circular recess ( 8th ), in which engages the fixing element of the first capacitor. A capacitor arrangement according to claim 30, wherein the Fixing element of the first capacitor in the recess engages that with the connection element held a rotation of the capacitor around its longitudinal axis allows is. Capacitor arrangement according to one of claims 30 or 31, in which - the second capacitor ( 2 ) at least one with at least one fixing element ( 71 ) external connection ( 7 ), - the connecting element ( 3 ) a second circular recess ( 8th ), in which engages the fixing element of the second capacitor. Capacitor arrangement according to Claim 32, in which the fixing element ( 71 ) in such a way in the recess ( 8th ) engages that when the connection element ( 3 ) a rotation of the second capacitor ( 2 ) is allowed around its longitudinal axis. Capacitor arrangement according to one of Claims 30 to 33, in which the fixing element ( 71 ) is a lead. Capacitor arrangement according to one of Claims 30 to 34, in which the external connection ( 7 ) a plurality of fixing elements ( 71 ) having. Capacitor arrangement according to Claim 35, in which the fixing elements ( 71 ) are arranged concentrically about a central axis.