DE102022001683A1 - Compensating clamping element and method for welding an electrical contact - Google Patents

Abstract

The invention relates to a compensating clamping element (100) for welding an electrical contact (46, 48) with at least two busbars (54, 56) at at least two electrical contact points (50, 52), in particular of battery cells (60), in particular of round battery cells ( 60), with at least one first pressure element (10) with a first clamping area (12) and at least one second pressure element (20) with a second clamping area (22). The second pressure element (20) is connected to the first pressure element (10) in an electrically insulated manner. The second clamping area (22) is arranged offset in an axial direction (L) relative to the first clamping area (12). The invention further relates to a device (200) with at least two compensating clamping elements (100) for joining electrical contacts (46, 48) by welding technology. at at least two electrical contact points (50, 52), in particular of battery cells (60), in particular of round battery cells (60). The invention further relates to a method for welding an electrical contact (46, 48).

Description

The invention relates to a compensating clamping element for welding an electrical contact with at least two busbars at at least two electrical contact points, in particular of battery cells, in particular round battery cells, as well as a method for welding an electrical contact with a compensating clamping element.

When joining electrical contacts, in particular on battery cells, for example by means of welding, for example laser welding, different joining levels can be formed due to the use of different material thicknesses for busbars or cell connectors and/or various height levels of the poles of a battery cell to be connected, in particular a round battery cell. Different hold-down devices or clamping elements are usually used here, which often press down the joining partners one after the other in a complex manner in order to close a prevailing gap.

The CN214921787U discloses a cell casing welding apparatus including a base and a clamping member. The cell casing is placed on the base. The clamping part is arranged on the base. The clamping part includes a clamping piece. The clamping piece can move relative to the base and is arranged on the base. During welding, the clamp clamps at least a portion of the upper surface of the cell housing to fix the cell housing during welding.

One object of the invention is to create a flexible compensating clamping element for welding an electrical contact, which enables short process times.

Another task is to create a device with at least two compensating clamping elements for welding electrical contacts, which enables short process times.

Another task is to specify a method for welding an electrical contact with a compensating clamping element, which enables short process times.

The aforementioned tasks are solved with the features of the independent claims.

Favorable refinements and advantages of the invention result from the further claims, the description and the drawing.

According to one aspect of the invention, a compensating clamping element is proposed for welding an electrical contact with at least two busbars at at least two electrical contact points, in particular of battery cells, in particular of round battery cells, with at least a first pressure element with a first clamping area and at least a second pressure element with a second Clamping range. The second pressure element is connected to the first pressure element in an electrically insulated manner. The second clamping area is arranged offset in an axial direction relative to the first clamping area.

Using the proposed compensating clamping element for welding an electrical contact, differences in height of electrical contact points can be specifically compensated for by dividing the compensating clamping element. For this purpose, at least two pressure elements that are individually acted upon by spring elements are used. The at least two pressure elements are provided for holding down different busbars at different electrical contact points. In this way, poles of battery cells, which have different heights in the axial direction of the battery cell and/or are arranged at different heights of the battery cell, can be reliably electrically contacted with the busbars. The respective printing elements are connected to each other firmly and in the correct position via webs. The pressure elements can be arranged coaxially, for example, for contacting round battery cells. Between the pressure elements relating to the different connection poles there is insulation made of an insulating material, for example ceramic or plastic, so that no short circuit can occur when the compensating clamping element is placed and all pole contacts of a battery cell can be effectively held down, fixed and welded in just one process step.

To carry out the welding joining process, a single compensating clamping element can be mounted individually on the welding tool, for example a laser welding optics with holder, of a battery cell.

Advantageously, unlike in the prior art, no consecutive process steps are necessary, such as holding down the positive pole with a device, welding the positive pole, moving the device away, placing a second device on the negative pole, welding ßen the negative pole, etc. The risk of a short circuit caused by touching the components involved when placing and moving the different devices can also be avoided.

Advantageously, shorter process times can be achieved with the proposed compensating clamping element, since welding is possible with faster repositioning of the beam. In addition, non-productive times can be shortened, for example by simultaneously setting up with a second hold-down device. A single compensating clamping element conveniently covers several welding areas in a short-circuit-proof manner. Additional hold-down devices and complex additional attachment procedures can be omitted.

By using spring elements with different strengths and/or spring characteristics, different pressure forces of the pressure elements can be set between the various welding areas if necessary. This is particularly advantageous if the connection poles are designed with different materials and different heights. This makes it possible to advantageously compensate for the electrical contacting of different height levels and/or material thicknesses.

The proposed compensating clamping element is particularly suitable for contacting different connection poles, in particular a round cell, with busbars/cell connectors.

The proposed compensating clamping element can be conveniently used in conjunction with conventional welding system technology. The compensating clamping element is particularly suitable for being used in combination with laser scanner welding optics, which quickly deflect the laser beam one after the other into the individual welding areas of the compensating clamping element.

Advantageously, the size of the compensating clamping element can be optimally adapted to the respective dimension of the battery cell to be welded. Surrounding components can be effectively protected from possible process splashes. When using possible protective gases, a more stable process is possible due to good protective gas coverage and less gas consumption, since less gas can escape due to the improved coverage by the compensating clamping element. This means that the compensating clamping element can be used flexibly either individually or in multiple versions on a corresponding device.

According to an advantageous embodiment of the compensating clamping element, at least one of the pressure elements can have a spring element for pressing the clamping area onto the busbar. This is particularly advantageous if the electrical contact points are made with different materials and different heights. This makes it possible to advantageously compensate for the electrical contacting of different height levels and/or material thicknesses.

According to an advantageous embodiment of the compensating clamping element, at least one of the pressure elements can have a recess on the edge for one of the busbars. In the case of a coaxial arrangement, the outer pressure element can have at least one recess for the passage of the busbar connecting the central connection pole. The compensating clamping element can also be used favorably in round battery cells with a central connection pole to which a busbar is connected.

According to an advantageous embodiment of the compensating clamping element, the pressure elements can be designed as hollow cylinders, with the second pressure element being arranged in an interior region of the first pressure element, in particular coaxially with the first pressure element. The compensating clamping element can also be used favorably in round battery cells with a central connection pole to which a busbar is connected.

According to an advantageous embodiment of the compensating tensioning element, at least one of the pressure elements can have a spring element which is arranged in a wall of the at least one pressure element. In particular, the spring element can be designed as a coil spring. This is particularly advantageous if the electrical contact points are made of different materials and of different heights, as is particularly the case with round battery cells with a central connection pole. This makes it possible to advantageously compensate for the electrical contacting of different height levels and/or material thicknesses.

According to an advantageous embodiment of the compensating clamping element, the second pressure element can be connected to the first pressure element via webs. In particular, the webs can extend radially and/or tangentially from the second pressure element to the first pressure element. In this way, the compensating clamping element can have enough free space to be able to weld with a laser beam even in the interior of the compensating clamping element.

According to an advantageous embodiment of the compensating clamping element, the recess can be arranged in the first pressure element, the recess being designed as a hollow cylinder sector of the wall of the first pressure element and forming a free space for the busbar to the second clamping area. As a result, the busbar can be guided to a central battery pole, whereby short-circuiting of the busbar and/or the battery pole with the compensating clamping element can be avoided.

According to an advantageous embodiment of the compensating clamping element, at least two pressure elements can encompass the electrical contact points in a plane transverse, in particular perpendicular, to the axial direction. In particular, the first pressure element can be adapted to a housing diameter of the battery cell to be contacted, in particular a round battery cell. In this way, two laterally spaced electrical contact points can be contacted with busbars. The first pressure element can in particular distribute the necessary force favorably to the housing of the battery cell.

Furthermore, the outer pressure piece can advantageously be designed in such a way that it is exactly adapted to the housing diameter of the battery cell to be welded, so that the applied pressure forces are distributed homogeneously over the entire housing cross section.

According to a further aspect of the invention, a device with at least two compensating clamping elements for welding electrical contacts of at least two battery cells is proposed, in particular of at least two round battery cells, with busbars at electrical contact points of the at least two battery cells simultaneously held down or can be held down by the at least two compensating clamping elements. In this case, the first and second pressure elements can also be connected to one another via the base plate of the device, so that the previously described connecting webs can be omitted.

Several compensating clamping elements, independent of the welding tool, can be attached to a device for clamping several cells at the same time, so that so-called scanner welding, also known as "welding-on-the-fly", is possible using robot-guided laser scanner welding optics at extremely short process times.

According to a further aspect of the invention, a method for welding an electrical contact with at least two busbars at at least two electrical contact points is proposed, in particular of battery cells, in particular of round battery cells, with a compensating clamping element. The method comprises at least the steps: placing the at least two busbars on the at least two electrical contact points, in particular a round battery cell; Placing a compensating clamping element on the at least two busbars; Holding down the at least two busbars with a first and a second pressure element of the compensating tensioning element; Welding the at least two busbars to the at least two electrical contact points; and removing the compensating tension element from the at least two busbars.

Advantageously, shorter process times can be achieved with the proposed method, since faster welding is possible with the compensating clamping element. In addition, non-productive times can be shortened, for example by simultaneously setting up with a second hold-down device. A single compensating clamping element conveniently covers several welding areas in a short-circuit-proof manner. Additional hold-down devices and complex additional attachment procedures can be omitted.

The proposed method can be used particularly favorably for contacting different connection poles, in particular a round cell, with busbars/cell connectors.

The process can conveniently be used in conjunction with conventional welding system technology. The method is particularly suitable for use in combination with laser scanner welding optics, which quickly deflect the laser beam one after the other into the individual welding areas of the compensating clamping element.

Further advantages result from the following drawing description. An exemplary embodiment of the invention is shown in the drawings. The drawings, description and claims contain numerous features in combination. The person skilled in the art will also expediently consider the features individually and combine them into further sensible combinations.

• 1 eine Übersicht über mehrere Prozessschritte eines Verfahrens nach einem Ausführungsbeispiel der Erfindung zum schweißtechnischen Fügen einer elektrischen Kontaktierung mit wenigstens zwei Stromschienen an wenigstens zwei elektrische Kontaktstellen, insbesondere von Batteriezellen, insbesondere von Batterierundzellen, mit einem Ausgleichsspannelement;
• 2 eine Draufsicht auf eine Unterseite des Ausgleichsspannelements nach einem Ausführungsbeispiel der Erfindung;
• 3 einen Längsschnitt durch das Ausgleichsspannelement nach 2; und
• 4 eine Vorrichtung mit einer Mehrzahl von Ausgleichsspannelementen zum schweißtechnischen Fügen elektrischer Kontaktierungen von Batteriezellen, insbesondere von Batterierundzellen.

Show:

• 1 an overview of several process steps of a method according to an exemplary embodiment of the invention for welding an electrical contact with at least two busbars to at least two electrical contact points, in particular of battery cells, in particular of bat terrier round cells, with a compensating clamping element;
• 2 a top view of an underside of the compensating clamping element according to an embodiment of the invention;
• 3 a longitudinal section through the compensating clamping element 2 ; and
• 4 a device with a plurality of compensating clamping elements for welding electrical contacts of battery cells, in particular round battery cells.

In the figures, identical or similar components are numbered with the same reference numerals. The figures only show examples and are not to be understood as limiting.

1 shows an overview of several process steps of a method according to an exemplary embodiment of the invention for welding an electrical contact 46, 48 with at least two busbars 54, 56 on at least two electrical contact points 50, 52, in particular of battery cells 60, in particular of round battery cells 60, with one Compensating clamping element 100. The procedure is carried out in 1 shown as an example on a round battery cell 60.

In a first process step S100, a busbar 56 is placed on an electrical contact point 52 of a round battery cell 60. The contact point 52 represents a central round battery pole of the round cell 60, which can be designed, for example, as a positive pole, while the further contact point 50 represents the flat upper end face of the cell cup of the round cell 60, for example designed as a negative pole.

In a second process step S102, the busbar 54, which can be designed in two parts, is placed on the electrical contact point 50.

Thereafter, in a third process step S104, a compensating clamping element 100 is placed on the first and second busbars 54, 56, which presses the busbars 54, 56 simultaneously with a predetermined force F in the axial direction L onto the contact points 50, 52.

Since the two contact points 50, 52 are offset in height in the axial direction L, the attached busbars 54, 56 have a height offset Δh, as marked in step S104.

The compensating clamping element 100 has at least a first pressure element 10 with a first clamping area 12 for holding down the busbar 54 arranged at the central contact point 52 and at least one second pressure element 20 with a second clamping area 22 for holding down the other busbars 54. The two pressure elements 10, 20 are preferably arranged coaxially to one another.

The second pressure element 20 is connected to the first pressure element 10 in an electrically insulated manner. The second clamping area 22 is arranged offset in the axial direction L relative to the first clamping area 12 by the same height offset Δh.

In 2 is a top view of the compensating clamping element 100 according to an embodiment of the invention, while in 3 a longitudinal section through the compensating clamping element 100 is shown.

The two pressure elements 10, 20 are designed as hollow cylinders 18, 28, the walls 16, 26 of which can be seen in the top view. The pressure elements 10, 20 are shown from one side, which is used to hold down the busbars 54, 56 when used as intended. Therefore, the clamping areas 12, 22 of the two pressure elements 10, 20 in 2 recognizable.

The second pressure element 20 of the compensating clamping element 100 is connected to the first pressure element 10 via webs 34, 36, 38. One of the webs 34 leads radially from the first pressure element 10 to the second pressure element 20, which is arranged coaxially to the first pressure element 10 in the interior region 32 of the first pressure element 10. The two further webs 36, 38 lead tangentially from the first pressure element 10 to the second pressure element 20.

The webs 36, 38 are guided tangentially to the second pressure element 20, since the first pressure element 10 has a recess 30 on the edge for the busbar 56, which contacts the central contact point 52.

The recess 30 is formed in the first pressure element 10 as a hollow cylinder sector of the wall 16 of the first pressure element 10 and thereby forms a free space for the busbar 56 to the second clamping area 22. The area of the wall 16 of the first pressure element 10 in the area of the recess 30 is opposite the clamping area 12 is offset backwards in the image plane. In 3 the recess 30 is shown in dashed lines. The recess 30 has a height in the axial direction L at least the size of the height offset Δh between the two busbars 54, 56.

The recess 30 thus ensures that the second busbar 56 can be brought to the second contact point 52 of the battery cell 60 without colliding with the compensating clamping element 100. In this case, the second busbar 56 is expediently first placed on the second contact point 52 and then the compensating clamping element 100 is placed on the busbar 56 in order to hold it down for welding.

The two pressure elements 10, 20 are arranged electrically insulated from one another so that the two busbars 54, 56 can be welded to the contact points 50, 52 of the battery cell 60 in one process step and a short circuit between the two contact points 50, 52 of the battery cell 60 is excluded. In the 2 and 3 For this purpose, an electrical insulation 58 is shown schematically, which encloses the second pressure element 20 and laterally covers the recess 30 on the webs 36, 38 between the first and second pressure elements 10, 20.

The insulation 58 can be designed, for example, as an electrically insulating film or coating. Alternatively, it is also possible for the second pressure element 20 to be made of an electrically insulating material, preferably plastic or ceramic. It is also possible that only a part of the second pressure element 20 is designed to be electrically insulating, for example the part below the in 3 shown spring element 24.

The webs 34, 36, 38 can also be designed to be electrically insulating, wherein the webs 34, 36, 38 can be made entirely or only partially from electrically insulating material.

As in 3 can also be seen, the pressure elements 10, 20 have spring elements 14, 24 for pressing the clamping areas 12, 22 of the pressure elements 10, 20 onto the busbar 54, 56. The spring elements 18, 28 can each be arranged in the wall 16, 26 of the pressure elements 10, 20 and can be designed, for example, as a coil spring. This is particularly advantageous if the electrical contact points 50, 52 are designed with different materials and different heights, as is the case in particular with round battery cells 60 with a central connection pole. This makes it possible to advantageously compensate for the electrical contacting of different height levels and/or material thicknesses. With the spring elements 18, 28, the hold-down force F can be favorably adapted to specifications for the material and/or design of the busbars 54, 56.

The pressure elements 10, 20 can include the electrical contact points 50, 52 in a plane transverse, in particular perpendicular, to the axial direction L. In particular, the first pressure element 10 can be adapted to a housing diameter of the battery cell 60 to be contacted, in particular a round battery cell 60. In this way, two laterally spaced electrical contact points 50 can be contacted with busbars 54. The first pressure element 10 can in particular distribute the necessary force favorably to the housing of the battery cell 60. Furthermore, the outer pressure piece 10 can advantageously be designed in such a way that it is exactly adapted to the housing diameter of the battery cell 60 to be welded, so that the applied pressure forces are distributed homogeneously over the entire housing cross section.

With the first and second pressure elements 10, 20 of the compensating clamping element 100, the first and second busbars 54, 56 can be held down for the welding process of the electrical contacts 46, 48 of the battery cell 60. This means that all pole contacts of a battery cell 60 can be effectively held down, fixed and welded in just one process step.

In the next process step, the first busbar 54 can then be welded to the first electrical contact point 50 and the second busbar 56 can be welded to the second electrical contact point 52. For this purpose, the compensating clamping element 100 offers the necessary space so that a laser beam 70, as in 3 shown, can impact on the busbars 54, 56.

In the last process step, the compensating clamping element 100 can be removed again from the busbars 54, 56.

4 shows a device 200 with compensating clamping elements 100 for welding electrical contacts 46, 48 of battery cells 60, in particular round battery cells 60.

The device 200 includes, for example, a base plate 80, which accommodates a plurality of compensating clamping elements 100. This means that busbars 54, 56 at electrical contact points 50, 52 of the at least two battery cells 60 can be held down simultaneously by the plurality of compensating clamping elements (100). The plurality of battery cells 60 can thus be electrically contacted and connected to the busbars 54, 56 at the same time.

In the exemplary embodiment shown in 4 Two cell connectors 62 for the electrical serial connection of battery cells 60 are shown as examples.

A plurality of compensating clamping elements can be attached to the device 200 for clamping several cells at the same time, regardless of the welding tool, so that so-called scanner welding, also known as "welding-on-the-fly", is made possible using robot-guided laser scanner welding optics at extremely short process times , since all pole contacts of a battery cell 60 can be effectively held down, fixed and welded in just one process step.

The device 200 may conveniently have an interface to a laser welding tool. The base plate 80 can be expanded as desired, so that a run of welded battery cells 60 can also be expanded.

Reference symbol list

10

Printing element

12

Clamping range

14

Spring element

16

Wall

18

Hollow cylinder

20

Printing element

22

Clamping range

24

Spring element

26

Wall

28

Hollow cylinder

30

recess

32

Interior

34

web

36

web

38

web

46

electrical contacting

48

electrical contacting

50

electrical contact point

52

electrical contact point

54

busbar

56

busbar

58

electrical insulation

60

Battery cell

62

Cell connector

70

laser beam

80

base plate

100

Compensating clamping element

200

contraption

L

axial direction

F

Hold-down power

Δh

Height offset

S100

Put on the power rail

S102

Put on another busbar

S104

Put on the compensating clamping element

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• CN 214921787 U [0003]

Claims (10)

Compensating clamping element (100) for welding an electrical contact (46, 48) with at least two busbars (54, 56) at at least two electrical contact points (50, 52), in particular of battery cells (60), in particular of round battery cells (60). at least one first pressure element (10) with a first clamping area (12) and at least one second pressure element (20) with a second clamping area (22), wherein the second pressure element (20) is connected to the first pressure element (10) in an electrically insulated manner, wherein the second clamping area (22) is arranged offset in an axial direction (L) relative to the first clamping area (12). Compensating clamping element Claim 1 , wherein at least one of the pressure elements (10, 20) has a spring element (14, 24) for pressing the clamping area (12, 22) onto the busbar (54, 56). Compensating clamping element Claim 1 or 2 , wherein at least one of the pressure elements (10, 20) has a recess (30) on the edge for one of the busbars (54, 56). Compensating clamping element according to one of the preceding claims, wherein the pressure elements (10, 20) are designed as hollow cylinders (18, 28), the second pressure element (20) in an inner region (32) of the first pressure element (10), in particular coaxial to the first Pressure element (10) is arranged. Compensating clamping element Claim 4 , wherein at least one of the pressure elements (10, 20) has a spring element (18, 28) which is arranged in a wall (16, 26) of the at least one pressure element (10, 20), in particular which is designed as a coil spring. Compensating clamping element Claim 4 or 5 , wherein the second pressure element (20) is connected to the first pressure element (10) via webs (34, 36, 38), in particular wherein the webs (34, 36, 38) extend radially and/or tangentially from the second pressure element (20). to the first pressure element (10). Compensating clamping element according to one of the Claims 4 until 6 , wherein the recess (30) is arranged in the first pressure element (10), the recess (30) being designed as a hollow cylindrical sector of the wall (16) of the first pressure element (10) and a free space for the busbar (56) to the second Clamping area (22) forms. Compensating clamping element according to one of the Claims 4 until 7 , wherein at least two pressure elements (10, 20) comprise the electrical contact points (50, 52) in a plane transverse, in particular perpendicular, to the axial direction (L), in particular wherein the first pressure element (10) has a housing diameter of the battery cell to be contacted ( 60), in particular round battery cell (60), is adapted. Device (200) with at least two compensating clamping elements (100) according to one of the preceding claims for welding electrical contacts (46, 48) of at least two battery cells (60), in particular of at least two round battery cells (60), wherein busbars (54, 56) at electrical contact points (50, 52) of the at least two battery cells (60) are simultaneously held down or can be held down by the at least two compensating clamping elements (100). Method for welding an electrical contact (46, 48) with at least two busbars (54, 56) at at least two electrical contact points (50, 52), in particular of battery cells (60), in particular of round battery cells (60), with a compensating clamping element ( 100) after one of the Claims 1 until 8th , at least comprising the steps - placing the at least two busbars (54, 56) on the at least two electrical contact points (50, 52), in particular a round battery cell (60); - Placing a compensating clamping element (100) on the at least two busbars (54, 56); - Holding down the at least two busbars (54, 56) with a first and a second pressure element (10, 20) of the compensating clamping element (100); - Welding the at least two busbars (54, 56) to the electrical contact points (50, 52); - Removing the compensating clamping element (100) from the at least two busbars (54, 56).

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