Production apparatus for producing battery cells, and method for controlling the production apparatus

Abstract

The invention relates to a production apparatus for producing battery cells, comprising a conveyor apparatus (1) for conveying a film web (3) along a specified web path, wherein a zigzag folding apparatus (2) for zigzag folding the film web (3) on a delivery table is provided, with a folder bar that can be moved back and forth, and the folder bar of the zigzag folding apparatus (2) comprises two support arms (11, 12) with two parallel deflector arrangements (9, 10) which are mounted on the support arms (11, 12) and are parallel to one another and between which the film web (3) is guided, the support arms (11, 12) for the folder bar being designed to carry out different movement sequences during at least one phase of their movements.

Description

[0001] Manufacturing equipment for the production of battery cells and method for controlling the manufacturing equipment

[0002] The present invention relates to a manufacturing device for producing battery cells with the features of the preamble of claim 1 and a method for controlling a manufacturing device with the features of the preamble of claim 12.

[0003] Manufacturing equipment for producing battery cells comprises at least one conveying device that transports a film web, e.g., in the form of a separator web, which is then fitted with electrodes in further processing. The film web is deflected at one or more deflection devices, whereby the film web should be transported with the most uniform web tension possible. To achieve this uniform web tension, it is known to provide web tension control devices, such as controllable dancers, in the guide of the film web. These dancers have a deflection device at which the film web is deflected, and whose deflection can be controlled to increase or decrease the web tension.

[0004] Since the film web is subject to increased frictional forces at the deflection devices due to surface contact, web tension control is inherently complex. Furthermore, web tension changes caused by frictional forces introduced by a deflection device after the web tension control cannot be compensated for. German patent DE 20 2022 100 081 U1 discloses a manufacturing device for battery cells with a Z-folding device. In this device, a film web is continuously fed and then folded around laterally inserted electrode sheets in a pulsed reciprocating motion. The film web is tensioned over a dancer in the feed to the Z-folding device and deflected within the device by a deflection device.The manufacturing device thus has a conveying device with a first conveying section in which the conveying device is designed to convey the film web with a cyclically varying conveying speed due to the movement in the Z-folding device, wherein at least one deflection device is provided in the first conveying section for deflecting the film web.

[0005] Furthermore, the lateral alignment of the film web in the feed to the Z-folding unit can change slightly, for example, due to minor changes in web tension in the edge zones. To compensate for this effect, an additional web edge control system is provided, which includes a web edge sensor directed at the edge of the film web to determine the exact position of the web edge. Depending on this determined position, a controllable deflection device is then activated to laterally shift the film web by changing the angle of the guide within the deflection mechanism, thus realigning the film web to its target position in the feed to the Z-folding unit.

[0006] Against this background, the invention is based on the objective of providing a manufacturing device for the production of battery cells with a Z-folding device, which enables the production of the battery cells with a further improved alignment of a foil web in the battery cells in relation to a predetermined target position.

[0007] To solve the problem, a manufacturing device with the features of claim 1 and a method for controlling such a manufacturing device with the features of claim 12 are proposed. Further preferred developments can be found in the dependent claims, the figures, and the accompanying description.

[0008] To solve the problem, a manufacturing device for producing battery cells is proposed, comprising a conveying device for conveying a film web along a predetermined web path, wherein a Z-folding device for Z-folding the film web on a storage table with a folding bracket movable back and forth is provided, wherein the folding bracket of the Z-folding device comprises two holding arms with two deflection devices held between the holding arms arranged parallel to each other, between which the film web is guided, wherein the holding arms of the folding bracket are arranged in at least one section of their movements to realize different movement sequences.

[0009] The advantage of the proposed solution lies in the fact that the position of the film web relative to its lateral orientation can be actively controlled during the folding process. The film web is aligned immediately before folding, or rather, before the layers of the film web are stacked to form the battery cell, without any further deflection that could adversely alter the film web's position. This allows the film web to be folded within the battery cell with maximum accuracy. The accuracy of the alignment of the folded film layers within the battery cell depends solely on the accuracy of the control process for aligning the holding arms during the folding process and the resulting correction of the film web's lateral position. The holding arms are connected to each other via two deflection devices, between which the film web is guided and deflected.These deflection devices are interlocked by controlling the movement of the holding arms relative to the film web guided between them, and are thereby inclined relative to the fed film web. This causes the film web to be deflected, or shifted, to one side depending on the relative position of the holding arms and the resulting angle of inclination of the deflection devices. Thus, the lateral position of the film web can be changed by controlling the angle of the holding arms relative to each other and the resulting inclination of the deflection devices, and accordingly controlled to a predetermined target value. The different movement sequences of the holding arms are reflected in their different movements relative to the fed film web, thereby changing the orientation of the deflection devices between the holding arms.

[0010] It is further proposed that the holding arms are configured to perform identical movements in the middle section of their movements and to execute different movements in the two opposing end sections. The control of the holding arms' movement is thus deliberately limited to the end sections of their folding movements, i.e., shortly before and after passing the reversal points, while the previously set path difference of the holding arms remains unchanged during the movement in the middle section. By controlling the relative position of the holding arms to each other and thus the alignment of the deflection devices, the film web is only pulled into the desired orientation in an end phase of the folding movement and folded back into this desired orientation in an initial phase of the subsequent folding process, before the same process is repeated after passing through the middle section.

[0011] It is further proposed that the retaining arms of the folding bracket be configured in at least one section of their movement to perform a pivoting motion around a pivot axis. The folding of the film web is thus effected by a pivoting movement of the retaining arms, which has the advantage that the drive of the retaining arms can be achieved very simply, without an intermediate gearbox, via a servo motor that is easy and very precisely controllable. The relative position of the retaining arms thus corresponds to a difference in the angle of rotation between the retaining arms.

[0012] It has proven particularly advantageous if the retaining arms of the folding bracket are configured in their different movement sequences to achieve a rotation angle difference of up to + / - 10 degrees, preferably + / - 3 degrees, and most preferably + / - 1.5 degrees relative to each other. The proposed rotation angle difference allows the deflection devices to be inclined by an angle of preferably + / - 3 degrees, and most preferably + / - 1.5 degrees, which in turn enables a lateral deflection of the film web during a folding process in the range of + / - 5 mm.It is further proposed that the holding arms are set up to achieve a swivel angle of 140 degrees during the swivel movement, and in a central section of the swivel angle of 80 degrees are set up to achieve identical movement sequences, and in the opposite end sections adjacent to the central section of 30 degrees each are set up to achieve different movement sequences.

[0013] It is further proposed that two independently controllable drive units be provided, with each drive unit motionally coupled to a holding arm. The holding arms can thus be driven independently of each other, without an intermediate gearbox, clutch, or any other mechanical coupling.

[0014] It is further proposed that the deflection devices are each formed by a deflection bar. The deflection bars are formed by a rod-shaped structure with at least one curved deflection section, against which the film web rests and is deflected depending on the position of the support arms. In the simplest form, the deflection bars are formed as cylindrical rods with a circular cross-section, around which the film web can be deflected at any section of the surface. The deflection bars of the two deflection devices are preferably arranged parallel to each other, thus forming a gap with a constant width between the surfaces of the deflection bars along their longitudinal extent, in which the film web is guided.It is further proposed that the deflection arms are each coupled at one end to one of the support arms in a manner that prevents displacement along their longitudinal directions, and at the other end in a manner that allows displacement. The fixed coupling forms a fixed bearing and the displacement coupling a sliding bearing in the connections between the deflection arms and the support arms. These connections allow the deflection arms to move relative to each other when the support arms move relative to one of the support arms, while remaining fixed relative to the other support arm.

[0015] It is further proposed that the first deflection link is coupled at its first end to the first support arm in a manner that prevents displacement along its longitudinal direction, and at its second end is coupled to the second support arm in a manner that allows displacement. Similarly, the second deflection link is coupled at its first end to the second support arm in a manner that prevents displacement along its longitudinal direction, and at its second end is coupled to the first support arm in a manner that allows displacement. Thus, the two deflection links are coupled to different support arms in a manner that prevents displacement and allows displacement, ensuring that when the deflection device or the deflection links are articulated, one of the deflection links is always coupled in a displacement-resistant connection to one of the support arms, while the other support arm is coupled in a displacement-resistant connection to the other deflection link. The same applies to the sliding connection between the deflection links and the support arms.

[0016] It is further proposed that the retaining arms be designed to be torsionally flexible with respect to an axis perpendicular to the movement of the deflection devices. Due to this torsionally flexible design, the retaining arms can easily rotate about their longitudinal axes when moving relative to each other. This reduces the bending moments exerted on the deflection devices during adjustment and the associated potential deformation of the deflection directions, ideally eliminating them entirely. Since the shape and orientation of the deflection devices are crucial for the precise folding of the film web within the stack, this can indirectly reduce the influence of errors on the folding process.

[0017] It is particularly preferred that the torsional stiffness of the support arms is lower than the sum of the bending stiffnesses of the deflection devices. The lower torsional stiffness of the support arms ensures that torsional forces acting on the support arms during pivoting first lead to deformation of the support arms and not to deformation of the deflection devices. This lower torsional stiffness effectively creates a kind of deformation hierarchy, in which the support arms are subordinate to the deflection devices and therefore deform first.

[0018] Furthermore, to solve the problem, a method for controlling a manufacturing device for producing battery cells, with a conveying device for conveying a film web along a predetermined web path, is proposed, wherein a Z-folding device for Z-folding the film web on a storage table with a folding bracket movable back and forth is provided, wherein the folding bracket of the Z-folding device comprises two holding arms with two deflection devices arranged parallel to each other between the holding arms, between which the film web is guided, in which the holding arms of the folding bracket are driven to different movement sequences in at least one section of their movements.

[0019] The proposed method, with its different movement sequences of the holding arms and their individual control, can be implemented particularly easily by providing two independently controllable drive units, with each drive unit driving one of the holding arms.

[0020] It is further proposed that, with regard to the transport movement of the film web upstream to the Z-folding device, a web edge sensor be provided to determine the actual position of the film edge, and that the drive devices be controlled depending on the signal from the web edge sensor. The position of the film edge is thus determined in relation to the transport movement of the film web in a section upstream of the folding bracket, so that the determined deviations of the actual position of the film edge from the specified target position can subsequently be corrected by appropriately controlling the position of the holding arms relative to each other.

[0021] It is further proposed that the holding arms be driven into a pivoting motion at least during one section of their movement, and that the angular velocities of the holding arms be controlled during these pivoting movements. The pivoting movements and their control allow for a particularly simple implementation of the folding motion and, in particular, the movement for correcting the lateral alignment of the film web. It is further proposed that the holding arms be driven into an identical movement during a central section of their pivoting movements and into individual pivoting movements during the opposite end sections. The control of the holding arm movements is thus limited to the end sections just before and after the reversal points, while the movement in the central section remains unchanged.

[0022] It is further proposed that the central section extend over a swivel angle of the support arms of 80 degrees and the end sections each extend over a swivel angle of the support arms of 30 degrees.

[0023] It is further proposed that a sensor device be provided to determine the position of the edge of the film web as it is deflected at one of the deflection devices, and that the pivoting movement of the retaining arms be controlled depending on the signal from the sensor device. This additional control of the film web's edge position can further increase the accuracy of the position and alignment of the film web's edges within the battery cell. The edge position of the film web is controlled based on the determined actual position of the edge at the folding bracket itself or at its deflection devices, i.e., in the deflected and thus "flattened" orientation.

[0024] It is further proposed that the sensor device determines the position of the film web's edge in a reversed position of the folding bracket. In this reversed position, the folding bracket remains stationary for a very brief moment in its reversal movement; that is, it does not perform any pivoting movement for a very short moment between the change in direction of the pivoting movements, so that determining the edge position at this point provides a particularly reliable and accurate signal of the edge position.

[0025] The invention is explained below with reference to preferred embodiments and the accompanying figures.

[0026] Fig. 1 shows a manufacturing device according to the invention in a first representation, and

[0027] Fig. 2 shows a manufacturing device according to the invention with a web edge sensor in a second representation, and

[0028] Fig. 3 shows an enlarged view of a section of the manufacturing equipment with a Z-folding device, and

[0029] Fig. 4 shows an enlarged view of the Z-folding device with a folding bracket with two holding arms in a reversed position, and

[0030] Fig. 5 shows an enlarged view of the Z-folding device with a folding bracket and a swivel angle with different sections, and

[0031] Fig. 6 shows a schematic representation of the path of the film web in the Z-folding device.

[0032] Figures 1 and 2 show a manufacturing device according to the invention with a conveying device 1 with a traction roller 28 and a tensioning device 4, a Z-folding device 2 and a film web 3 fed in the conveying device 1 to the Z-folding device 2.

[0033] The film web 3 is deflected multiple times in the conveyor 1 via a plurality of deflection devices 5, 8, 6, 7 arranged one after the other in the direction of the film web 3's travel, before being fed to the Z-folding device 2. The film web 3 can, for example, have a thickness of 10 to 25 µm and an air permeability of 100 to 300 Gurley seconds. The air permeability can be measured, for example, with a Gurley™ Densometer 40N, available from RYCOBEL GROUP. Exemplary film webs 3 are known on the market, for example, from the companies Celgard or Entek.

[0034] The tensioning device 4 comprises a stationary deflection device 8 and a dancer 19 with a deflection device 5. The deflection device 5 of the dancer 19 is connected at its ends to a drive unit 22 via pivot arms 21 and 23, respectively. When the drive unit 22 is activated, the deflection device 5 can be pivoted via the pivot arms 21 and 23. By pivoting the deflection device 5, the web tension in the film web 3 can be decreased or increased. Subsequently, the film web 3 is guided by two spaced, stationary deflection devices 6 and 7 and is deflected twice in opposite directions to form an S-shaped path.

[0035] The film web 3 is then fed to the Z-folding device 2, where it is folded into a Z-fold in a reciprocating folding motion. At the same time, anodes and cathodes are alternately inserted into the folds of the film web 3 from opposite sides. The Z-folding device 2 has a folding bracket with two holding arms.

[0036] The support arms 11 and 12 and two parallel deflection devices 9 and 10, held between the support arms 11 and 12, are arranged at a small distance from each other with a gap of constant width along the longitudinal extent of the deflection devices 9 and 10. The support arms 11 and 12 are each connected or coupled to a drive unit 16 and 17 in the form of a servo motor, which moves the support arms 11 and 12.

[0037] 12 is driven into a reciprocating pivoting motion upon activation. In the feed to the Z-folding device 2, the film web 3 is deflected at a final deflection device 7 and guided between the deflection devices 9 and 10 of the holding arms 11 and 12 to a stack 25 on a storage table. The folding frame with the holding arms 11 and 12 and the deflection devices 9 and 10 pivots around this stack, as can also be seen in Fig. 6. During this process, the film web 3 is periodically folded into the Z-fold in a reciprocating folding motion, with the film web 3 being deflected at the deflection device 9 or at the deflection device 10 depending on the position of the holding arms 11 and 12.

[0038] The last deflection device 7, at which the film web 3 is deflected before entering the Z-folding device 2, is arranged such that the deflected film web 3, in its vertical extension corresponding to the vertical S, passes through the pivot axes SA of the holding arms 11 and 12 of the Z-folding device 2. In their basic movement, the holding arms 11 and 12 perform a pivoting movement about the pivot axis SA that is symmetrically aligned with the vertical S; that is, the pivot angles of the holding arms 11 and 12 are identical from the vertical S to the right and left sides, i.e., to the two edge sides of the insertion compartments of the film web 3. Thus, during the folding movement, the film web 3 is folded by the same length to the left and to the right, resulting in identical changes in web tension in the film web 3, the maximum value of which is, however, limited to the lowest possible value.

[0039] At least one of the deflection devices 5, 6, 7, 8, 9, 10 is designed as a compressed air beam, which is connected to an air pressure device not shown and can be pressurized with an overpressure of 1.1 to 1.5 bar.

[0040] In the feed device 1, a measuring device is provided at the first deflection device 8 located downstream of the dancer 19. The deflection device 8 is formed by a deflection section supported at both ends. In this case, the measuring device consists of two load cells assigned to the supports of the deflection section, which determine the pressure exerted by the film web 3 on the deflection device 8 and thus the web tension in the film web 3. The load cells are deliberately designed with a high measuring capacity to generate a measurement signal that is as linear as possible within a measuring range of a few Newtons and a deviation of 10 ± 2 N from the required web tension.

[0041] The film web 3 is folded in the Z-folding device 2 in a reciprocating motion, whereby the dancer 19, depending on the design, is controlled in the deflection of the deflecting device 5 via the pivot arms 21 and 23 in relation to the change in length of the film web 3 caused by the movement of the Z-folding device 2, either in the Z-folding device 2 or in the conveyor 1. The film web 3 is folded into a Z-shape by the Z-folding device 2 in a reciprocating, timed folding motion, whereby the movement of the Z-folding motion introduces additional changes in length and thus fluctuations in web tension into the film web 3 in the Z-folding device 2 itself or in the feed to the Z-folding device 2. These changes in length or web tension fluctuations are then compensated by the control of the dancer 19 in the feed of the foil web 3 to the Z-folding device 2, i.e. before they arise, and ideally reduced to zero.

[0042] The feeding device 1 thus has a first conveying section 24 in which the film web 3 is transported at a cyclically varying conveying speed. In the present embodiment, the first conveying section 24 is the section between the dancer 19 and the discharge table, on which the Z-folding device 2 folds the film web 3 into a stack 25, as will be described in more detail below.

[0043] Between the dancer 19 and the Z-folding device 2, a plurality of deflection devices 8, 6, 7 are provided in the first conveying section 24, preferably all of which are designed as pneumatic guide bars. This ensures that the film web 3 is deflected downstream to the dancer 19 in the feed to the Z-folding device 2 exclusively without contact via air cushions, i.e., with minimal friction against the pneumatic guide bars. This minimizes any further changes in web tension introduced into the film web 3 after it has exited the dancer 19 during subsequent deflections. The deflection devices 5, 6, 7, 8, 9, and 10 can be designed as deflection bars in the form of cylindrical bolts or rods, against whose outer surfaces the film web 3 rests and is deflected accordingly.If one or more of the deflection devices 5, 6, 7, 8, 9 or 10 are designed as pneumatic beams, the film web 3 is deflected without contact or almost without contact with the least possible friction on the outer surface of the respective pneumatic beam, forming an air cushion.

[0044] In the conveyor 1 leading to the Z-folding device 2, a deflecting device 7 is provided, at which the film web 3 is deflected directly to the Z-folding device 2. The change in length of the film web 3 between the deflecting device 7 and the delivery table can be seen in more detail in Fig. 6, whereby, for the sake of simplicity, the sequence of movements is described only with reference to the front holding arm 11.

[0045] The holding arm 11 is shown in four different positions 11, 11', 11'' and 11'' to illustrate the movement of the film web 3 with the deflecting devices 9 and 10. The last deflecting device 7, at which the film web 3 is deflected to the Z-folding device 2, is arranged such that, in a vertical central position of the holding arm 11, the film web 3, in its imaginary extension after deflection at the deflecting device 7, runs through the pivot axis SA of the holding arm 11.

[0046] The vertical center position of the holding arm 11 is designated here as 11", while the extreme positions of the holding arm 11 are designated 11 and 11'", and a second center position is designated 11'. The same applies to the deflection devices 9 and 10 between the holding arms 11 and 12. The film web 3 is folded into the stack 25 by the movement of the holding arms 11 and 12 on the delivery table, with the film web 3 being fixed at the left end of the stack 25 and at the right end of the stack 25 by a hold-down device 26 after the end of each folding operation and before the start of the next. Simultaneously, the electrodes (not shown) are inserted into the laterally open folds thus formed.

[0047] The holding arms 11 and 12 are driven into the pivoting motion by the drive units 16 and 17, the movement and dimensions of the holding arms 11 and 12 being described below only with reference to the front holding arm 11. The holding arm 11 is preferably dimensioned with a length FB such that it has a length of 55 to 75 percent of the width B of the stack 25 to be folded on the storage table. Furthermore, it is arranged such that its pivot axis SA is located at a distance X from the surface of the stack 25, which is less than half the length FB of the holding arm 11. The holding arm 11 is pivoted by a pivot angle of at least 120 degrees, preferably at least 140 degrees, and particularly preferably at an angle of at least 160 degrees between the reversal points, the pivoting motion being symmetrical to the perpendicular S passing through the pivot axis SA.

[0048] In the recognizable left-hand inverted position of the holding arm 11, the hold-down device 26 has just been placed on the left end of the stack 25, so that the folded film web 3 is fixed at the left end of the stack 25 above the electrode that has just been inserted from the left. The holding arm 11 is pivoted to such an extent that the film web 3 is deflected maximally at the deflection device 9 facing the vertical S and, starting from the deflection device 9, runs upwards in a short section over the length L2 to the stack 25 or to the hold-down device 26 that fixes the film web 3. Furthermore, in the path of the Z-folding device 2, the film web 3 has a section L1 extending from the last deflection device 7 before the Z-folding device 2 to the deflection device 9 of the holding arm 11, where the film web 3 is deflected.Thus, the film web 3 in the Z-folding device 2 has a web length from the last deflection device 7 to the end of the film web 3 fixed via the hold-down device 26, which corresponds to the sum of L1 plus L2.

[0049] If the holding arm 11 is moved clockwise to the center position marked 11' in the subsequent movement, the length segments L1 and L2 change until the film web 3 is no longer deflected in position 11' of the holding arm 11 and runs in a straight section L3 from the last deflection device 7 to the end fixed by the hold-down device 26. In this position, the film web 3 is not deflected at any of the deflection devices 9 and 10, so that the path of the film web 3 between the deflection device 7 and the hold-down device 26, with length L3, has the shortest length during the folding movement, since firstly, the length segment L2 is no longer present, and secondly, the length segment L3 is shorter than the length segment L1, which is easily recognizable from the geometry of the web path in Fig. 6.During the further movement of the holding arm 11 during the pivoting movement clockwise to the central position shown with 11”, the film web 3 is applied to the deflecting device 10 further away from the vertical S and deflected until, in a central position 11” of the holding arm 11, it runs in a vertical section with a length L5 from the last deflecting device 7 to the deflecting device 10 in position 10” of the holding arm 11 and from the deflecting device 10 in position 10” in a section with a length L4 to the end of the film web 3 fixed to the hold-down device 26 on the stack 25. The path of the film web 3 thus has a length L4 plus L5 from the deflecting device 7 to the hold-down device 26 in this position of the holding arm 11, which in turn is longer than the shortest length L3 of the path of the film web 3 described above in position 11' of the holding arm 11.

[0050] This shows that the length of the film web 3 in the Z-folding device 2 initially decreases from a length L1 plus L2 to a length L3 during the pivoting movement of the holding arm 11, and then steadily increases again until the opposite reversal point is reached. Since the holding arm 11 is periodically pivoted from one reversal point to the other and back again to fold the film web 3, this results in a cyclically varying conveying speed of the film web 3 in the first conveying section 24 between the dancer 19 and the stack 25 in which the Z-folding device 2 is located.

[0051] This cyclically varying conveying speed and the associated change in web tension in the film web 3 are compensated for by appropriately controlling the movement of the dancer 19 with its deflection device 5 in the leading path of the film web 3, so that the web tension change is ideally reduced to zero. To minimize the web tension changes caused by the change in the length ratios described above in the web path of the film web 3 in the Z-folding device 2, the holding arm 11 has the shortest possible length FB of 55 to 75 percent of the width B of the stack 25. This allows the additional length L2 of the web path of the film web 3 from the hold-down device 26 to the deflection device 9 of the holding arm 11 in the reverse position to be reduced to the shortest possible length, which in turn reduces the length reduction to the shortest possible length L3.Furthermore, the pivot axis SA is arranged at a distance X from the folding plane of the stack 25, which is less than half the length FB of the retaining arm 11, so that the retaining arm 11 pivots with the deflection devices 9 and 10 as close as possible to the folding plane. Furthermore, the pivot angle of the retaining arm 11 is at least 120 degrees, preferably at least 140 degrees, and particularly preferably at least 160 degrees. All of these dimensions contribute individually to a reduction in web tension fluctuations, whereby the reduction of web tension fluctuations can be achieved by a combination of the proposed dimensions, and a maximum reduction of web tension fluctuations can be achieved by a combination of all dimensions and design parameters.It is particularly important that the section between the deflection device 9 and the hold-down device 26 in the reverse position of the holding arm 11 is as short as possible according to the length L2, since this is crucial for the reduction in the length of the web path from the position of the holding arm 11 in the reverse position until the holding arm 11 reaches the position 11.

[0052] By controlling the dancer 19 based on the change in length of the web path of the film web 3 in the Z-folding device 2, the described change in length during the lead-in is already compensated, so that ideally no change in web tension occurs. Since the change in length of the web path is defined solely by the geometry of the web path of the film web 3 in the different positions of the holding arm 11, the control can be carried out according to a predefined program based on knowledge of the position of the holding arm 11; a separate measuring device for determining the change in length is not required.

[0053] Furthermore, the web tension of the film web 3 is additionally determined by the measuring device associated with the deflection device 8, formed by the load cells, immediately after the dancer 19 has exited, so that any remaining web tension fluctuations in the film web 3 are detected in isolation. The dancer 19 is then additionally controlled depending on the web tension determined by the measuring device, so that the control of the dancer 19 is a combination of control depending on the change in length of the web travel in the Z-folding device 2 and control depending on the actual remaining web tension. This allows the web tension fluctuations to be further reduced.

[0054] The holding arms 11 and 12 are coupled to independently controllable drive units 16 and 17, allowing them to pivot independently. Furthermore, the deflection devices 9 and 10 are each fixedly coupled at a first end 13, 18 to one of the holding arms 11, 12 and slidably coupled at a second end 14, 15 to the other holding arm 11, 12, so that they are fixedly clamped at one end relative to one of the holding arms 11, 12, while at the other end they can move relative to the other holding arm 11, 12 by means of a floating bearing, as can be seen in Figure 3.This allows the retaining arms 11 and 12 to perform different pivoting movements up to a certain rotation angle difference D of up to + / - 10 degrees, preferably + / - 3 degrees, particularly preferably + / - 1.5 degrees to each other, without introducing additional bending stresses into the retaining arms 11 and 12 and the deflection devices 9 and 10, as can be seen in Figure 4.

[0055] It is particularly advantageous if the deflection device 10 formed by a first deflection beam with a first end 18 is coupled to the first support arm 11 in a manner fixed against displacement with respect to its longitudinal direction and to the second support arm 12 in a manner slidable with respect to its second end 14, and the other deflection device 9 formed by a second deflection beam with its first end 13 is coupled to the second support arm 12 in a manner fixed against displacement with respect to its longitudinal direction and to the first support arm 11 in a manner slidable with respect to its second end 15. Thus, the retaining arms 11 and 12 are coupled to one of the deflection devices 9 or 10 in a displacement-resistant manner and coupled to the other deflection device 9 or 10 in a displacement-resistant manner, so that one retaining arm 11, 12 forms a fixed spatial relationship to one of the deflection devices 9 and 10 for a deflection device 9, 10, i.e., a fixed bearing, while the other retaining arm 11, 12 forms a floating bearing for the same deflection device.

[0056] This allows the deflection devices 9 and 10 to perform a slight displacement movement relative to each other when the holding arms 11 and 12 are rotated relative to one another, resulting in an inclined position relative to the fed film web 3. While the gap between the deflection devices 9 and 10 decreases slightly in the longitudinal direction, it remains constant along the entire length of the deflection devices 9 and 10. Therefore, the guidance of the film web 3 is not impaired even when the holding arms 11 and 12 and the deflection devices 9 and 10 are in an angular position.

[0057] With regard to the transport direction of the film web 3, a web edge sensor 27, as shown in Figure 2, is provided upstream of the deflection devices 6 and 7. This sensor determines the actual position of the web edge of the film web 3, i.e., the lateral orientation of the film web 3 in the feed to the Z-folding device 2. If the actual position of the film web 3 deviates from the target position within a predetermined tolerance range, either the drive unit 16 or the drive unit 17 is activated. This causes either the holding arm 11 or the holding arm 12 to rotate at an increased or decreased angular velocity relative to the other holding arm 11 or 12, thus changing the angular position of the deflection devices 9 and 10 relative to the film web 3.The altered angular position of the deflection devices 9 and 10 deflects the film web 3 at a different angle and shifts it laterally. This altered deflection angle and the resulting lateral shift of the film web 3 are dimensioned such that, ideally, the film web 3 is shifted laterally by exactly the difference between the actual position determined by the web edge sensor 27 and the target position, and the film web 3 is then folded with the edge aligned in the target position.

[0058] The retaining arms 11 and 12 are preferably pivoted symmetrically by a pivot angle of 140 degrees to a perpendicular S passing through the pivot axis SA, as can be seen in Figure 5.

[0059] The holding arms 11 and 12 are pivoted identically, i.e., with the same angular velocity, in a central section M arranged symmetrically to the vertical S, through an 80-degree pivot angle. Thus, the relative orientation of the deflection devices 9 and 10 to each other does not change in the central section M, and the film web 3 is deflected at a constant angle with respect to a vertical line running through the film web 3. The correction of the film web 3's orientation then only occurs in the end sections E of the pivoting movement at a pivot angle of 30 degrees, shortly before and after passing the reversal point of the pivoting movement, i.e., the formation of the fold in the film web 3.

[0060] The correction of the orientation of the film web 3 thus takes place immediately before or during the folding process itself, so that the orientation of the film web 3 can no longer be negatively affected by further influences. This allows for the highest possible accuracy in the alignment of the layers of the film web 3 within the battery cell.

[0061] Furthermore, a sensor device 29, as shown in Figure 1, can be provided. Its sensor field is directed towards the deflection devices 9 and 10 passing through a reversal point, thus determining the position of the edges of the film web 3 in the deflection between the deflection devices 9 and 10. This provides an additional signal that determines the actual position of the edge during folding of the film web 3 immediately upon forming the fold on one side of the stack 25, or, with two sensor devices 29 on opposite sides, the positions of the edges on both sides of the stack 25. If this determined actual position deviates from a predetermined target position, the position of the edge can be additionally controlled and / or regulated, allowing for even more precise control of the edge position within the stack 25.

[0062] 1 funding facility

[0063] 2 Z-folding device 3 Film web

[0064] 4 Clamping device

[0065] 5 Deflection device

[0066] 6 Deflection device

[0067] 7 Deflection device 8 Deflection device

[0068] 9 Deflection device

[0069] 10 Deflection device

[0070] 11 Support arm

[0071] 12 Support arm 13 First end

[0072] 14 Second Ending

[0073] 15 Second Ending

[0074] 16 Drive unit

[0075] 17 Drive unit 18 First end

[0076] 19 dancers

[0077] 20 lateral surface area

[0078] 21 Swivel arm

[0079] 22 Drive unit 23 Swivel arm

[0080] 24 First funding phase

[0081] 25 stacks

[0082] 26 hold-down devices

[0083] 27 Web edge sensor 28 Traction roller

[0084] 29 Sensor device A Extension angle

[0085] B width

[0086] D Rotation angle difference E End section

[0087] FB length

[0088] L1 length

[0089] L2 length

[0090] L3 length L4 length

[0091] L5 length

[0092] M Middle section

[0093] S Perpendicular

[0094] SA Swivel axis X distance

Claims

Claims:

1. Manufacturing apparatus for the production of battery cells, comprising a conveying device (1) for conveying a film web (3) along a predetermined web path, wherein -a Z-folding device (2) for Z-folding the film web (3) on a storage table with a folding bracket that can be moved back and forth is provided, wherein -the folding bracket of the Z-folding device (2) two retaining arms (11, 12) comprising two deflection devices (9, 10) held between the retaining arms (11, 12), preferably arranged parallel to each other, between which the film web (3) is guided, characterized in that -the retaining arms (11 ,12) of the folding bracket are arranged in at least one section of their movements to realize different movement sequences.

2. Manufacturing device according to claim 1, characterized in that -the holding arms (11 ,12) are arranged in a central section (M) of their movements to realize identical movement sequences and in the two opposite end sections (E) of their movements to realize different movement sequences.

3. Manufacturing apparatus according to one of claims 1 or 2, characterized in that -the retaining arms (11, 12) of the folding bracket are arranged in at least one section of their movement sequences to realize a pivoting movement about a pivot axis (SA). are.

4. Manufacturing device according to claim 3, characterized in that -the retaining arms (11 ,12) of the folding bracket are arranged in their different movement sequences to achieve a rotation angle difference (D) of up to + / - 10, preferably up to + / - 3 degrees, particularly preferably of + / - 1.5 degrees to each other.

5. Manufacturing apparatus according to claim 2 and according to one of claims 3 or 4, characterized in that -the holding arms (11, 12) are arranged during the swiveling movement to achieve a swivel angle of 140 degrees, and -are set up in a central section (M) of the swivel angle of 80 degrees to achieve identical movement sequences, and -are set up in the opposite end sections (E) adjacent to the central section (M) at 30 degrees each to realize different movement sequences.

6. Manufacturing device according to one of claims 1 to 5, characterized in that -two independently controllable drive units (16, 17) are provided, and -each a drive unit (16,17) is coupled to a holding arm (11 , 12) in terms of motion.

7. Manufacturing device according to one of claims 1 to 6, characterized in that -the deflection devices (9, 10) are each formed by a deflection bar.

8. Manufacturing device according to claim 7, characterized in that -the deflection arms are coupled with a first end (13,18) to one of the retaining arms (11 , 12) in a manner that prevents displacement with respect to their longitudinal directions, and with a second end (14, 15) to the other retaining arm (11 , 12) in a manner that allows displacement.

9. Manufacturing device according to claim 8, characterized in that -the first deflection beam is coupled with its first end (18) in a manner that prevents displacement with respect to its longitudinal direction to the first support arm (11) and with its second end (14) in a manner that allows displacement with the second support arm (12), and -the second deflection arm is coupled with its first end (13) in a manner that prevents displacement with respect to its longitudinal direction to the second support arm (12) and with its second end (15) in a manner that allows displacement with the first support arm (11).

10. Manufacturing device according to one of claims 1 to 9, characterized in that -the retaining arms (11, 12) are designed to be torsionally flexible with respect to an axis perpendicular to the movement of the deflection devices (9, 10).

11. Manufacturing device according to claim 10, characterized in that -the torsional stiffness of the retaining arms (11 , 12) is less than the sum of the bending stiffnesses of the deflection devices (9,10).

12. Method for controlling a manufacturing plant for the production of battery cells, with -a conveying device (1) for conveying a film web (3) along a predetermined web path, wherein -a Z-folding device (2) for Z-folding the film web (3) on a storage table with a folding bracket that can be moved back and forth is provided, wherein -the folding bracket of the Z-folding device (2) comprises two retaining arms (11, 12) with two deflecting devices (9, 10) arranged parallel to each other and held between the retaining arms (11, 12), between which the film web (3) is guided, characterized in that -the retaining arms (11 ,12) of the folding bracket are driven to different movement sequences in at least one section of their movements.

13. Method according to claim 12, characterized in that two independently controllable drive devices (16, 17) are provided, wherein each drive device (16, 17) drives a holding arm (11, 12).

14. Method according to claim 12, characterized in that, with respect to the transport movement of the film web (3) upstream to the Z-folding device (2), a web edge sensor (27) detecting the actual position of the edge of the film web (3) is provided, and -the drive devices (16, 17) depending on the The signal from the web edge sensor (27) is controlled.

15. Method according to one of claims 12 to 14, characterized in that -the holding arms (11, 12) are each driven to a pivoting movement, and -the rotational angular velocities of the holding arms (11 , 12) are controlled during the swivel movements.

16. Method according to claim 15, characterized in that the holding arms (11, 12) are driven to an identical movement in a central section (M) of their pivoting movements and are driven to an individual pivoting movement in the opposite end sections (E) of the pivoting movements.

17. Method according to claim 16, characterized in that the central section (M) extends over a pivot angle of the retaining arms (11 ,12) of 80 degrees and the end sections (E) each extend over a pivot angle of the retaining arms (11 ,12) of 30 degrees.

18. Method according to one of claims 15 to 17, characterized in that -a sensor device (29) is provided which determines the position of the edge of the foil web (3) deflected at one of the deflection devices (9, 10), and the pivoting movement of the holding arms (11, 12) is controlled depending on the signal of the sensor device (29).

19. Method according to claim 18, characterized in that -the sensor device (29) determines the position of the edge of the film web (3) in a reversed position of the folding bracket.

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