Method for producing a cell contacting system for a traction battery of a motor vehicle, and device

Abstract

The invention relates to a method for producing a cell contacting system for a traction battery of a motor vehicle, in which cell connectors (14) cut out from a metal sheet (12) are inserted together and at the same time into an injection-moulding cavity (16) and, while completely separate from one another, are overmoulded with a plastic (18) to produce the cell contacting system, as a result of which the plastic (18) forms a carrier of the cell contacting system after the plastic has cured.

Description

[0001] Method for manufacturing a cell contacting system for a traction battery of a motor vehicle and apparatus

[0002] The invention relates to a method for manufacturing a cell contacting system for a traction battery of a motor vehicle and to a device for manufacturing a cell contacting system for a traction battery of a motor vehicle.

[0003] From WO 2022 / 199981 A1, a method for manufacturing a cell contacting system for a cell array of energy storage cells of an electrical energy storage device is known. In this method, a first part of a conductor pattern for interconnecting the energy storage cells is manufactured by structuring a conductor material, whereby recesses are cut out of the conductor material during structuring. Furthermore, the method provides that the structured conductor material is integrated into an electrically insulating carrier by joining it through the primary forming of an insulating material, wherein the insulating material is arranged at least partially at the recesses for the mechanical connection of conductors of the conductor pattern.The process further provides for the formation of access openings in the insulating material to expose conductor track sections serving as cell contacts and to fabricate at least a second part of the conductor track pattern. Furthermore, the process provides for the fabrication of at least one second part of the conductor track pattern by further structuring the conductor material, specifically by cutting additional recesses through the access openings in the insulating material. The process also provides for the structured conductor material to be overmolded and / or potted with the insulating material during the joining process by primary forming.

[0004] The object of the present invention is to provide a solution by which a cell contacting system can be manufactured particularly easily and quickly. This object is achieved according to the invention by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the dependent claims, the description, and the figures. Features, advantages, and possible embodiments set forth in the description for one of the subject matter of the independent claims are to be regarded, at least analogously, as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as of any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the dependent claims.

[0005] The invention relates to a method for manufacturing a cell contacting system for a traction battery of a motor vehicle. The traction battery of the motor vehicle is specifically designed to provide electrical energy for the vehicle's electric powertrain. Thus, the motor vehicle can be electrically driven by means of electrical energy from the traction battery. Furthermore, it is specifically provided that the traction battery comprises a plurality of battery cells, in particular a plurality of cylindrical cells. These battery cells are contacted within the traction battery by the cell contacting system, whereby the battery cells are connected to one another in series and / or parallel by means of the cell contacting system. The cell contacting system thus ensures the contacting of the battery cells of the traction battery.The process involves inserting cell connectors cut from a sheet of metal simultaneously into an injection molding cavity. The sheet of metal can be, for example, a large, thin sheet, specifically 400 millimeters long and 300 millimeters wide. The sheet is made of a metallic material. The cell connectors can be cut from the sheet using a laser cutting device and / or a punching device. They can be completely cut out of the sheet or only partially, with each connector being held to a residual lattice of the sheet by at least one web, such as a microjoint or a nanojoint.By inserting all cell connectors simultaneously into the injection molding cavity, their arrangement can be both particularly quick and easy. Furthermore, the process involves overmolding the cell connectors, which are arranged in the injection molding cavity while completely separated from one another, with a plastic material. After curing, this plastic forms a carrier for the cell contacting system. Overmolding the cell connectors with the plastic allows for a particularly simple and secure bonding to the carrier.

[0006] In a possible further development of the invention, it is provided that the sheet metal, in which the cell connectors are connected to one another via connecting webs, in particular by each cell connector being connected to a residual grid of the sheet metal via at least one connecting web, is inserted into the injection molding cavity of an injection mold. Furthermore, it is provided that when the injection mold is closed, the connecting webs, in particular all connecting webs, are separated by the injection mold for the complete cutting out of the cell connectors. This means that the sheet metal, as a pre-formed, pre-wound body, is inserted into the injection molding cavity of the injection mold, whereby the cell connectors are completely separated from one another by the injection mold when the mold is closed.After the injection mold closes, the cell connectors, arranged completely separated from one another in the injection cavity, can be back-injected or overmolded with the plastic to produce the carrier. The pre-formed sheet metal is thus placed into the injection mold, and upon closing the mold, the connections between the cell connectors, or the connections between the cell connectors and the remaining grid, are severed. The cell connectors are then overmolded with the plastic. This allows all cell connectors to be placed into the injection cavity simultaneously and with exceptional ease and precision. Furthermore, it ensures that the cell connectors are completely separated from one another within the injection cavity before the injection molding process begins.In this process, the cell connectors are easily separated from the remaining grid by closing the injection mold.

[0007] In this context, it is specifically intended that at least one of the cell connectors is reshaped by the injection mold during the closing process, before the connecting webs are separated. The injection mold is thus designed not only to completely separate the respective cell connectors by separating their connecting webs, but also to reshape at least one of the cell connectors. This allows the at least one cell connector to be bent and / or deep-drawn by the injection mold, particularly during the closing process. Consequently, a particularly large number of manufacturing steps for the cell contacting system can be implemented using the injection mold. This enables the cell contacting system to be manufactured very quickly using a significantly smaller number of tools.

[0008] In an alternative embodiment of the invention, the sheet metal, in which the cell connectors are connected to one another via respective webs, is placed into a forming cavity. Within this cavity, the cell connectors are completely separated from one another by cutting the webs. Furthermore, the cell connectors are transferred together from the forming cavity to the injection molding cavity. Thus, the pre-formed sheet metal is placed into the forming cavity, the connecting webs of the sheet metal are then cut to separate the cell connectors, and subsequently, the cell connectors are placed simultaneously and together into the injection molding cavity. The cell connectors are then back-injected or overmolded with the plastic within the injection molding cavity. Therefore, separate cavities are used for separating the cell connectors and for overmolding them with the plastic.This allows each cavity to be particularly well adapted to the process, for example with regard to its geometry, which is to be carried out with the cell connectors in a respective cavity.

[0009] In this context, it may be particularly useful to use a rotating cube to transfer the completely separated cell connectors from the forming cavity to the injection molding cavity. The rotating cube is a cube mold that can be used within a multi-stage turning process, specifically a 90-degree or 180-degree multi-stage turning process. The rotating cube is the cube mold of a cube molding machine in which the cube mold rotates on a turning unit between two spaced-apart columns or plates. For example, the forming cavity, in which the cell connectors are completely separated, can be located on one side of the rotating cube.By rotating the rotary cube, the forming cavity can be aligned with the injection molding cavity, allowing all cell connectors to be transferred simultaneously and with exceptional ease from the forming cavity to the injection molding cavity. The injection molding cavity can be positioned, for example, on one of the plates or columns of the cube machine. This enables a large number of manufacturing steps for the cell contacting system to be performed using the cube machine, with the rotary cube facilitating the particularly easy transfer of cell connectors from the forming cavity to the injection molding cavity.

[0010] In a further alternative embodiment of the invention, the sheet metal, in which the cell connectors are connected to one another via connecting webs, is placed into the injection molding cavity. Subsequently, the connecting webs are separated using a forming tool, and then the cell connectors are overmolded with the plastic in the injection molding cavity using an injection mold. This means that the separation of the cell connectors from one another by cutting the connecting webs and the overmolding or back-injection of the completely separated cell connectors are carried out using different tools, with the cell connectors being arranged in the injection molding cavity during both process steps.Because the cell connectors are still connected to each other via the connecting webs over the residual grid while being inserted into the injection molding cavity, they can be inserted together particularly easily. Furthermore, the forming tool and the mold itself can be optimally adapted to the respective action to be performed by the tool, especially the separation of the connecting webs and the overmolding or back-injection of the cell connectors with the plastic. This allows for particularly effective optimization of the respective processes of separating the cell connectors and overmolding them with the plastic.Furthermore, the cell contacting system can be manufactured particularly quickly because the cell connectors require very little movement, as they are positioned in the injection molding cavity both during the separation of the connecting bridges and during overmolding with the plastic.

[0011] In this context, a further development of the invention may provide that the injection molding cavity is moved first to the forming tool and then to the injection mold by means of a rotating cube. This means that a cube-type machine can be used, with the injection molding cavity arranged on the rotating cube. The forming tool can be arranged on a first column or on a first plate, and the injection mold can be arranged on a second column or on a second plate. By rotating the rotating cube, the injection molding cavity can be oriented towards either the forming tool or the injection mold, depending on the process step to be performed. The rotating cube makes it possible to implement the respective process steps to be carried out by the tools particularly easily at the cell connectors arranged in the injection molding cavity.

[0012] In a further possible embodiment of the invention, the cell connectors are cut from an aluminum sheet. This allows the cell connectors to be both highly electrically conductive and exceptionally lightweight. This results in a particularly lightweight traction battery incorporating the cell contacting system. Furthermore, the cell contacting system ensures a particularly reliable electrical connection between the traction battery cells.

[0013] The invention further relates to a device for manufacturing a cell contacting system for a traction battery of a motor vehicle. The device comprises an injection molding cavity into which cell connectors for the cell contacting system can be inserted and in which the cell connectors can be overmolded with a plastic. The device is configured to carry out a method as already described in connection with the inventive method for manufacturing a cell contacting system for a traction battery of a motor vehicle. In particular, it is provided that the device comprises a cube machine with a rotating cube as a cube tool, arranged between two columns or between two plates and rotatable relative to the plates or columns.

[0014] Further features of the invention may become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures themselves, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0015] The drawing shows in the single figure (Fig. 1) a process diagram for a method for manufacturing a cell contacting system for a traction battery of a motor vehicle. Fig. 1 shows a process diagram for a method for manufacturing a cell contacting system. In the process shown in Fig. 1, a carrier board-cell connector complex 10 is manufactured. The cell contacting system can be manufactured from this carrier board-cell connector complex 10 by connecting the cell connectors 14 to at least one ribbon cable, which can also be referred to as a flexible printed circuit.

[0016] In this process, cell connectors 14, cut from a sheet 12, are placed together and simultaneously into an injection molding cavity 16 and overmolded with a plastic 18 to produce the cell contacting system, in particular the carrier board-cell connector complex 10 for the cell contacting system. After curing, the plastic 18 forms a carrier for the carrier board-cell connector complex 10. In this case, the cell connectors 14 are cut from an aluminum sheet 12. In the process shown in Fig. 1, a cube machine 20 is used to produce the carrier board-cell connector complex 10. This cube machine 20 comprises two spaced-apart columns 22, between which a cube die 24 is arranged. The cube die 24 can be rotated relative to the columns 22 by means of a turning unit. The cube die 24 can also be referred to as a rotary die.In the present case, it is provided that the cube machine 20 comprises a first tool, which in this case is a forming tool 26, and a second tool, which in this case is an injection molding tool 28.

[0017] The process scheme according to Fig. 1 is explained below. In a first process step V1, the sheet metal 12 is placed in the cube machine 20, specifically in a forming cavity 30 of the cube tool 24. In a second process step V2, the forming tool 26 is brought into contact with the cube tool 24, thereby forming the sheet metal 12 arranged in the forming cavity 30, whereby the cell connectors 14 are punched out from a residual grid 32 of the sheet metal 12. Subsequently, the forming tool 26 is removed from the cube tool 24, thus opening the cube machine 20. The residual grid 32 is removed from the cube machine 20 in the third process step V3. The cell connectors 14 remain in the forming cavity 30 of the cube tool 24.In a fourth process step V4 of the process, the cube tool 24 is rotated 180 degrees by means of the turning unit and thus reoriented from its orientation facing the forming tool 26 to an orientation facing the injection mold 28. The cell connectors 14 remain in their completely separated state in the forming cavity 30. In a fifth process step V5, the cube tool 24 with the forming cavity 30 is brought into contact with the injection mold 28, in particular by closing the cube machine 20. There are now two alternative possibilities: Either the fifth process step V5 is followed by a sixth process step V6a, in which the cell connectors 14 arranged in the forming cavity 30 are overmolded with the plastic 18. The forming cavity 30 thus simultaneously serves as the injection molding cavity 16, or the injection molding cavity 16 was previously used as the forming cavity 30.Subsequently, in a final process step Vs, the carrier board cell connector complex 10 can be demolded and thus removed from the cube machine 20.

[0018] As an alternative to the sixth process step V6a, a sixth process step V6b can be carried out within the process after the fifth process step V5, in which, with the cube tool 24 in the position against the injection mold 28, the completely separated cell connectors 14 are transferred together and simultaneously from the forming cavity 30 to the injection mold cavity 16. Subsequently, in a seventh process step V7, the cube tool 24, in particular the forming cavity 30, is removed from the injection mold 28 and rotated relative to the injection mold 28 by means of the turning unit, thereby rotating the forming cavity 30 from its orientation facing the injection mold 28 back to an orientation facing the forming tool 26.In a subsequent eighth process step V8, the cube tool 24, with a surface not having the forming cavity 30, in particular with a side opposite the forming cavity 30, can be placed against the injection mold 28, and then the cell connectors 14 arranged in the injection mold cavity 16 can be overmolded with the plastic 18. The cube tool 24 thus serves as a cover for the injection mold cavity 16 during the injection molding process. Following the eighth process step V8, the final process step Vs can be carried out, in which the carrier board-cell connector complex 10 is demolded from the cube machine 20 and removed.

[0019] As an alternative to the method described in connection with Fig. 1, it can be provided that the sheet metal 12, in which the cell connectors 14 are connected to each other via connecting webs, is placed in the injection molding cavity 16 of an injection mold 28 and, when the injection mold 28 is closed, the connecting webs are separated by the injection mold 28 for the complete cutting out of the cell connectors 14. In this case, at least one of the cell connectors 14 can be reshaped by the injection mold 28 before the connecting webs are separated when the injection mold 28 is closed.

[0020] The process enables the cell contacting system, and in particular at least the carrier board-cell connector complex 10 for the cell contacting system, to be manufactured particularly easily and with a high degree of automation. Furthermore, instead of being removed, for example by etching, any burr present on the cell connectors 14 can simply be overmolded with the plastic 18 during the injection molding process. The process thus enables highly integrated manufacturing of the carrier board-cell connector complex 10 in a one-shot injection molding process. For this purpose, an injection molding machine with at least one rotary die, in particular a double die, is used as the system equipment.

[0021] Overall, the invention demonstrates how a highly integrated cell contacting system can be manufactured in a particularly simple way.

[0022] Reference symbol list

[0023] 10 T carrier board cell connector complex

[0024] 12 sheets

[0025] 14 cell connectors

[0026] 16 injection molding cavity

[0027] 18 plastic

[0028] 20 dice machine

[0029] 22nd pillar

[0030] 24 dice tools

[0031] 26 Forming tool

[0032] 28 Injection molds

[0033] 30 Forming cavity

[0034] 32 remaining grids

[0035] V1 to V8 and Vs respective process steps

Claims

1. Patent claims 1. Method for manufacturing a cell contacting system for a traction battery of a motor vehicle, in which cell connectors (14) cut from a sheet (12) are inserted together and simultaneously into an injection molding cavity (16) and are overmolded with a plastic (18) in a completely separate state for the manufacture of the cell contacting system, whereby the plastic (18) forms a carrier of the cell contacting system after it has hardened.

2. Method according to claim 1, characterized in that the sheet (12) in which the cell connectors (14) are connected to each other via respective connecting webs is inserted into the injection molding cavity (16) of an injection molding tool (28) and when the injection molding tool (28) is closed, the connecting webs are separated for the complete cutting out of the cell connectors (14) by means of the injection molding tool (28).

3. Method according to claim 2, characterized in that at least one of the cell connectors (14) is reshaped by means of the injection molding tool (28) when closing the injection molding tool (28) before separating the connecting webs.

4. Method according to claim 1, characterized in that the sheet (12) in which the cell connectors (14) are connected to each other via respective connecting webs is placed in a forming cavity (30) in which the cell connectors (14) are completely separated from each other by separating the connecting webs, and the cell connectors (14) are transferred together from the forming cavity (30) to the injection molding cavity (16).

5. Method according to claim 4, characterized in that a rotating cube (24) is used to transfer the completely separated cell connectors (14) from the forming cavity (30) to the injection molding cavity (16).

6. Method according to claim 1, characterized in that the sheet (12) in which the cell connectors (14) are connected to each other via respective connecting webs is placed in the injection molding cavity (16), the connecting webs are then separated by means of a forming tool (26) and the cell connectors (14) are then overmolded with the plastic (18) in the injection molding cavity by means of an injection molding tool (28).

7. Method according to claim 6, characterized in that the injection molding cavity (16) is moved first to the forming tool (26) and then to the injection molding tool (28) by means of a rotating cube (24).

8. Method according to one of the preceding claims, characterized in that the cell connectors (14) are cut from an aluminum sheet.

9. Device for manufacturing a cell contacting system for a traction battery of a motor vehicle, comprising an injection molding cavity (16) into which cell connectors (14) for the cell contacting system can be inserted and in which the cell connectors (14) can be overmolded with a plastic (18), wherein the device is configured to carry out a method according to one of the preceding claims.

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