Production device for producing battery cells

Abstract

The invention relates to a production device for producing battery cells, comprising a conveying device (1) for conveying a film web (3) along a specified web path, wherein the conveying device (1) has a first conveying portion (24) in which the conveying device (1) is designed to convey the film web (3) at a conveying speed which varies cyclically in particular, the first conveying portion (24) is equipped with at least one deflecting device (5, 6, 7, 8, 9, 10) for deflecting the film web (3), and the deflecting device (5, 6, 7, 8, 9, 10) is in the form of a compressed air bar (12) which is connected or can be connected to a compressed air device and which has an air-permeable circumferential portion (14) for discharging an air flow provided by the compressed air device.

Description

[0001] Manufacturing equipment for the production of battery cells

[0002] The present invention relates to a manufacturing device for the production of battery cells having the features of the preamble of claim 1.

[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, the control of the web tension is fundamentally complex, and web tension changes caused by frictional forces introduced by a deflection at a deflection device after the web tension control cannot be compensated.

[0005] German patent application DE 20 2022 100 081 U1 discloses a manufacturing device for producing battery cells with a Z-folding device in which a film web is continuously fed and then folded around laterally inserted electrode sheets in a timed, 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 deflecting device. The manufacturing device thus includes a conveying unit with a first conveying section in which the conveying unit is designed to transport the film web at a cyclically varying conveying speed due to the movement within the Z-folding device, and in which at least one deflecting device is provided for deflecting the film web.

[0006] A disadvantage is that the cyclically varying conveyor speed introduces additional web tension fluctuations into the film web, which in turn can lead to defects in the stacked battery cells.

[0007] Against this background, the invention is based on the objective of providing a manufacturing device for the production of battery cells in which the film web is conveyed and / or folded with a more uniform web tension.

[0008] To solve the problem, a manufacturing device with the features of claim 1 is proposed. Further preferred embodiments of the invention can be found in the dependent claims, the figures, and the accompanying description.

[0009] According to the basic concept of the invention, claim 1 proposes that the deflection device in the first conveying section be designed as a compressed air beam, connectable to or already connected to a compressed air system, with an air-permeable circumferential section for the exit of an airflow supplied by the compressed air system. The proposed solution allows the film web to be deflected with minimal friction losses and forces, thus reducing the web tension fluctuations in the film web during deflection. As a result, the film web floats on the outer surface of the compressed air beam during deflection, forming an air cushion, with virtually no contact occurring. This minimizes the web tension introduced into the film web during deflection and consequently also reduces its changes.This is particularly advantageous in connection with the cyclically varying conveying speeds of the film web, as this prevents varying frictional forces and associated web tension changes in the film web due to the lack of contact, or at least reduces the friction-related influence.

[0010] It is further proposed that the air-permeable circumferential section be formed by a field of air outlet openings distributed circumferentially and axially around the compressed air beam. This proposed design of the air-permeable circumferential section allows air to flow uniformly over a defined circumferential section of the compressed air beam's surface, forming an air cushion of as constant a thickness as possible between the surface and the film.

[0011] The air cushion or air pillow can be formed particularly well and uniformly by incorporating a porous material structure into the air-permeable circumferential section of the compressed air beam. The air outlet openings are formed by the cross-sectional areas of spaces or pores within this porous material structure on an outer surface of the compressed air beam. This porous material structure can, for example, be sponge-like with a chaotic distribution and connection of individual partial flow channels and pores, making it much more cost-effective to manufacture, as precise flow channel configurations are unnecessary. The porous material structure can be produced, for instance, through a sintering process involving the simple melting of a mass of coarse-grained metal particles.

[0012] It is further proposed that the compressed air beam has continuous compressed air channels in the air-permeable circumferential section, with the air outlet openings formed by the cross-sectional areas of these compressed air channels on an outer surface of the compressed air beam. The compressed air channels enable a controlled and directed flow of air through and out of the air-permeable circumferential section, thus allowing for a controlled build-up of the air cushion to a predetermined thickness.

[0013] To form an air cushion with a thickness that is as constant as possible, it is further proposed that the air outlet openings each have an average cross-sectional area of ​​0.004 to 0.1 mm². 2 preferably from 0.01 to 0.06 mm 2 , particularly preferably from 0.02 to 0.04 mm 2exhibit. The determined cross-sectional area refers to the cross-sectional area of ​​the individual air outlet openings and thus determines the outflow conditions of the air from each air outlet opening.

[0014] Furthermore, to form an air cushion with a constant thickness, it is preferred that the air outlet openings together constitute a total area of ​​20 to 80 percent, preferably 40 to 60 percent, and particularly preferably 45 to 55 percent of the total area of ​​the air-permeable circumferential section.

[0015] It is further proposed that the extension angle of the air-permeable circumferential section in the circumferential direction of the pneumatic beam corresponds at least to the intended wrapping angle of the film web on the pneumatic beam, so that the film web is guided over the air cushion at a distance without contact over its entire wrapping angle relative to the pneumatic beam.

[0016] It is further proposed that the compressed air system be designed and configured to pressurize the compressed air beam, and thus the air-permeable section, with an air pressure of 1.1 to 1.5 bar. The proposed air pressure thus creates a pressure difference of 0.1 to 0.5 bar acting on the film web compared to the ambient pressure assumed to be 1.0 bar, which is sufficient for the formation of the air cushion.

[0017] It is further proposed that the compressed air system be configured and designed to supply the compressed air beam with a volume flow of 40 to 100 l / min, preferably 70 to 100 l / min, and particularly preferably 70 to 80 l / min. The proposed volume flow ranges allow the air cushion to be reliably constructed in relation to the forces acting on the film web during deflection and the web tension acting on the film web.

[0018] It is further proposed that the conveying device includes a dancer with a deflecting device for the film web that is movable transversely to the conveying direction of the film web, wherein the dancer separates the first conveying section from a second conveying section arranged upstream with respect to the conveying direction of the film web. The dancer serves to compensate for the web tension fluctuations induced by the cyclically varying conveying speeds, so that the web tension fluctuations in the film web are at least lower upstream of the first conveying section.

[0019] It is further proposed that the first conveying section include a Z-folding device for folding the film web into a Z-shape on a delivery table using a reciprocating deflection device. The proposed Z-folding device allows the film web to be folded into the Z-shape particularly easily and at high speed, while the electrodes are alternately inserted laterally into the resulting compartments.

[0020] It is further proposed that the dancer be controllable depending on the change in length of the film web caused by the movement of the deflection device of the Z-folding unit. The dancer is thus specifically designed to compensate for the changes in length generated by the Z-folding unit and the associated web tension fluctuations, by performing a periodic movement with the deflection device that corresponds to the movement of the deflection device of the Z-folding unit, which causes a change in the length of the film web in the leading section that is opposite to the change in length of the deflection device of the Z-folding unit.

[0021] It is further proposed that the conveying device includes a deflection device at which the film web is directly deflected to the Z-folding device, and that the change in the length of the film web is formed by the changing length of the film web between the deflection device and the delivery table. The deflection device feeds the film web directly to the Z-folding device, i.e., without any further intermediate deflection device, so that the film web is fed by the deflection device to the Z-folding device in a straight line and is merely moved back and forth for the Z-folding process. The change in length underlying the control is then preferably the length of the film web between the deflection device and the delivery table, which, in relation to the movement of the Z-folding device, is precisely the change in length of the Z-folding device that needs to be compensated for and which also induces the web tension changes.

[0022] It is further proposed that a measuring device detecting the web tension of the film web be provided between the Z-folding device and the dancer, and that the movement of the dancer's deflection device be controllable depending on the web tension detected by the measuring device. The movement of the dancer's deflection device is thus additionally controlled depending on the web tension fluctuations that are still present in the film web between the dancer and the first conveying section, even though the dancer has already compensated for the web tension fluctuations caused by the movement of the Z-folding device through a pre-movement. Through the proposed additional control of the dancer, or rather...With its deflection device, the web tension can be controlled even more precisely and quickly. The measuring device's arrangement detects the web tension in the film after it has passed the dancer, and deviations from a predetermined web tension are then compensated for retrospectively by adjusting the dancer accordingly in the lead-up. This enables particularly fast and accurate control of the web tension before the film is folded in the Z-folding unit.

[0023] It is further proposed that a plurality of deflection devices, all designed as pneumatic guides, be provided between the dancer and the Z-folding unit. By designing all deflection devices between the dancer and the Z-folding unit as pneumatic guides, the web tension, after being controlled by the movement of the dancer's deflection device, is no longer altered or only altered to a minimal extent, since the film web is transported and deflected from the dancer to its folding point practically without contact or with as little contact as possible.

[0024] It is further proposed that the deflection device of the Z-folding unit comprises a folding bracket pivoting about a pivot axis, with two retaining arms, and two deflection devices arranged parallel to each other at the ends of the retaining arms between the retaining arms of the folding bracket. The film web is guided between these deflection devices. The folding bracket can be driven by a drive unit to fold the film web into a stack in a periodic pivoting motion about a pivot axis from a first reversal point to a second reversal point and vice versa. The Z-folding unit guides the movement of the film web during the folding process by guiding the film web between the deflection devices and, during the pivoting motion of the folding bracket, alternately deflecting it at each of the deflection devices depending on the position of the folding bracket, thereby carrying the film web along with the pivoting device during the movement.The folding bracket performs a periodically repeating pivoting movement between two reversal points with a changing direction, the reversal points being the extreme deflection points of the film web at one of the deflection devices with a maximum wrap around the respective deflection device.

[0025] It is further proposed that the film web in the conveying device is deflected by a deflecting device in the immediate conveying process to the Z-folding device. The deflecting device is arranged such that, starting from the deflecting device, the film web, in the center position of the folding bracket, is aligned with the pivot axis of the folding bracket in such a way that its imaginary extension runs through the pivot axis of the folding bracket. During folding, the folding bracket performs a periodically reversing pivoting motion through a defined pivot angle between two reversal points. The center position of the folding bracket corresponds to the position in which it has traversed exactly half the pivot angle from one reversal point to the other.In other words, the center position of the folding bracket is the position in which the folding bracket has an identical angle or distance to both reversal points, i.e., it is positioned midway between the reversal points. The pivoting movement is aligned such that the center position of the folding bracket simultaneously corresponds to its vertical orientation.

[0026] It is further proposed that the folding bracket be pivotable from the first turning point to the second turning point at an angle of at least 120 degrees, preferably at least 140 degrees, and particularly preferably at an angle of at least 160 degrees.

[0027] It is further proposed that the retaining arms of the folding bracket have a length, extending from its pivot axis to the deflection devices, which corresponds to 55 to 75 percent of the width of the stack to be folded.

[0028] It is further proposed that the folding bracket be pivotable about a pivot axis which has a distance to a folding plane of the stack that is less than half the length of the folding bracket.

[0029] Furthermore, to solve the problem, an arrangement with a manufacturing device according to one of claims 1 to 20 with a film web arranged therein is proposed, wherein the film web is preferably designed as a separator web of a battery cell.

[0030] Furthermore, to solve the problem, a method for controlling a manufacturing device with the features of one of claims 1 to 9 is proposed, in which a dancer with a deflecting device for the film web movable transversely to the conveying direction of the film web is provided in the conveying device, wherein the dancer is controlled and / or regulated in its movement by means of the deflecting device for controlling the web tension in the film web.

[0031] It is further proposed that in the first conveying section a Z-folding device for Z-folding the film web on a storage table with a deflecting device that can be moved back and forth is provided, and that the dancer is controlled and / or regulated depending on the change in length of the web path of the film web caused by the movement of the Z-folding device in the Z-folding device or in the conveying device.

[0032] It is further proposed that the conveyor system include a deflection device where the film web is directly deflected to the Z-folding unit, and that the change in the web length underlying the control system is determined by the changing length of the film web between the deflection device and the delivery table. The deflection device, from which the film web is directly deflected to the Z-folding unit, forms the last fixed point in the film web guide before the folding movement of the film web begins on the delivery table. Thus, the length of the film web between the deflection device and the delivery table corresponds exactly to the section of the film web that changes periodically in length during the folding process, corresponding to the folding process itself.

[0033] It is further proposed that a measuring device detecting the web tension of the film web be provided between the Z-folding device and the dancer and / or on the dancer, and that the movement of the dancer's deflection device be controlled in its orientation depending on the web tension detected by the measuring device. This allows the web tension to be additionally controlled, to compensate for further influences, depending on the web tension measured in the film web after the dancer has passed or on the dancer, and its deviations. This compensates for the length change caused by the length change in the Z-folding device and the resulting web tension fluctuations, thereby further reducing web tension fluctuations.

[0034] It is further proposed that the film web is deflected at a deflection section of a deflection device, which is supported at two ends enclosing the deflection section. The measuring device consists of two load cells, one assigned to each end of the deflection device. The load cells measure the compressive force exerted by the film web on the deflection section, which is directly related to the web tension acting in the film web and thus represents a quantity representative of the web tension. Since the compressive force is measured at both ends, any unevenly distributed web tension in the film web or a lateral displacement of the film web from the center of the deflection section is also measured.

[0035] It is further proposed that the web tension in the film web be controlled to a value of 10 + / - 2 N.

[0036] Furthermore, to solve the problem according to claim 29, a compressed air beam for use as a deflection device in a manufacturing device according to the preamble of claim 1 is proposed, wherein the compressed air beam has an air-permeable circumferential section.

[0037] Further preferred embodiments of the pneumatic spar can be found in claims 30 to 34.

[0038] The invention is explained below with reference to preferred embodiments and the accompanying figures. Figure 1 shows a manufacturing device according to the invention in a first representation, and

[0039] Fig. 2 shows a manufacturing device according to the invention in a second representation, and

[0040] Fig. 3 shows a schematic representation of the manufacturing facility with a measuring device for detecting the web tension, and

[0041] Fig. 4 shows an enlarged view of a pneumatic beam with a distance sensor, and

[0042] Fig. 5 shows an enlarged view of the path of the film web in the Z-folding device.

[0043] Figures 1 and 2 show a manufacturing device according to the invention with a conveying device 1 with a clamping device 4, a Z-folding device 2 and a film web 3 fed in the conveying device 1 to the Z-folding device 2.

[0044] 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 4110N, available from RYCOBEL GROUP. Examples of film webs 3 are available on the market from companies such as Celgard or Entek. The clamping 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 via a pivot arm 21 to a drive unit 22, wherein the deflection device 5 can be pivoted via the pivot arms 21 when the drive unit 22 is activated.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-apart, fixed deflection devices 6 and 7, and is deflected twice in opposite directions to form an S-shaped path. If the deflection devices 6 and 7 are to be used as a web edge control device, they can also be made pivotally movable by means of a suitable drive device.

[0045] The film web 3 is then fed to the Z-folding device 2, in which the film web 3 is folded into a Z-fold in a back-and-forth folding motion, while anodes and cathodes are alternately inserted into the folds of the film web 3 from different sides.

[0046] The Z-folding device 2 has a folding bracket 11 with two holding arms and two parallel deflection devices 9 and 10 arranged between the holding arms at the ends of the holding arms, which are positioned a short distance apart. Each holding arm of the folding bracket 11 is connected to a servo motor 16, which, when activated, drives the folding bracket 11 into a reciprocating pivoting motion. In the feed to the Z-folding device 2, the film web 3 is deflected at a final deflection device 7 and folded between the deflection devices 9 and 10 of the folding bracket 11 into a stack 25 on a delivery table, with the folding bracket 11 pivoting around the delivery table, as can also be seen in Fig. 5.The film web 3 is periodically folded into the Z-fold in a back-and-forth folding motion, whereby the film web 3 is deflected at the deflecting device 9 or at the deflecting device 10 depending on the position of the folding bracket 11.

[0047] 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 perpendicular S, passes through the pivot axis SA of the folding bracket 11 of the Z-folding device 2. The folding bracket 11 performs a symmetrical pivoting movement about the pivot axis SA, i.e., the pivot angles of the folding bracket 11, starting from the perpendicular S to the right and left sides, i.e., to the two edge sides of the insertion compartments in the film web 3 for inserting the electrodes, are identical. 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.

[0048] At least one of the deflection devices 5, 6, 7, 8, 9, 10 is designed as a compressed air beam 12, which is shown by way of example in Fig. 4. The compressed air beam 12 is connected to a compressed air device (not shown) and can be pressurized with an overpressure of 1.1 to 1.5 bar. The compressed air beam 12 has an air-permeable circumferential section 14, which extends over an angle of extension A in the circumferential direction of the compressed air beam 12. The air-permeable circumferential section 14 has a plurality of air outlet openings distributed in the axial and circumferential directions, each with an average opening diameter of 0.02 to 0.1 mm. The air outlet openings are axially and radially offset from one another, arranged in a uniform field distribution of 100 to 300 air outlet openings per cm² in the circumferential section 14 on the compressed air beam 12. The circumferential section 14 can, for example,be manufactured using a laser sintering process.

[0049] The film web 3 is deflected at the outer surface 18 of the pneumatic tube 12. In one embodiment, the pneumatic tube 12 has a cavity 17 which radially defines the inner boundary of the air-permeable circumferential section 14 and is thus fluidically connected to it. When compressed air is applied to the cavity 17 of the pneumatic tube 12, the air flows out of the air-permeable circumferential section 14 and forms an air cushion 15 between the film web 3 and the outer surface 18 of the pneumatic tube 12. This causes the film web 3 to lose contact with the outer surface 18 and be deflected without contact at the pneumatic tube 12. This significantly reduces the frictional forces acting on the film web 3 during deflection at the pneumatic tube 12, which in turn reduces the influence of these frictional forces on the web tension in the film web 3.

[0050] Alternatively, the compressed air beam 12 can also be designed, at least in the area of ​​the air-permeable circumferential section 14, completely, i.e., up to the core, as a porous material structure in the manner of a sponge or a closely meshed grid structure, whereby the air then flows in from the compressed air device at a point in the porous material structure and flows out again over the outer surface of the compressed air beam 12 to form the air cushion.

[0051] Furthermore, the pneumatic beam 12 can very easily also be provided as a deflection device 5 of the dancer 19 or another tensioning device 4, which can be arranged at any point on the conveying device 1 or the Z-folding device 2. In this case, the web tension in the film web 3 can be controlled very simply by controlling and changing the air pressure in a cavity 17 or the porous material structure of the pneumatic beam 12. The web tension is increased by increasing the air pressure in the cavity 17, as this increases the thickness of the air cushion 15 and thus the unwound length of the deflected section of the film web 3. In other words, this increases the pressure force exerted on the film web 3, which displaces the film web 3 radially outwards and increases the web tension in the film web 3.A reduction in web tension is then achieved in reverse by reducing the air pressure in the cavity 17. Furthermore, the use of the pneumatic beam 12 as a dancer 19 offers the advantage that the previously required drive unit 22 and the pivot arms 21 on the existing dancer 19 can be omitted.

[0052] Furthermore, the pneumatic beam 12, in conjunction with a distance sensor 13 directed from the outside onto the film web 3 deflected by the pneumatic beam 12, can also be used as a web tension sensor device, in that the distance sensor 13 detects the distance to the film web 3. For a defined air pressure in the cavity 17 or in the porous material structure, the distance between the distance sensor 13 and the film web 3 is directly dependent on the web tension in the film web 3, since an increase in web tension causes the film web 3 to be forced towards the outer surface 18 of the pneumatic beam 12, thereby increasing the distance to the distance sensor 13 and decreasing the thickness of the air cushion 15. Conversely, a decrease in web tension reduces the distance between the film web 3 and the distance sensor 13. The web tension in the film web 3 is preferably 10 ± 2 N.

[0053] Since the air outlet openings in the air-permeable circumferential section 14 have very small opening diameters, the circumferential section 14 is difficult to discern with the naked eye. For this reason, the circumferential section 14 is preferably marked by an optical marking at its center or its edges, so that the compressed air beam 12 can be aligned more easily during assembly, and the film web 3 is then deliberately deflected along the aligned air-permeable circumferential section 14 of the compressed air beam 12.

[0054] 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 23 assigned to the supports of the deflection section, which detect 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 23 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.

[0055] The film web 3 is folded in the Z-folding device 2 in a reciprocating motion, whereby the dancer 19 is controlled, depending on the design, either by the deflection of the deflecting device 5 via the swivel arms 21 or by the air pressure applied to the pneumatic beam 4, in response to the change in length of the film web 3 in the Z-folding device 2 or in the conveyor 1 caused by the movement of the Z-folding device 2. 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, orWeb 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.

[0056] 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. 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, which are preferably all designed as pneumatic guides 12.This means that the film web 3 in the feed to the Z-folding device 2 is deflected downstream to the dancer 19 exclusively without contact via air cushions, i.e. with minimal friction, so that the further change in web tension introduced into the film web 3 after the dancer 19 has run through it during the further deflections can be reduced to a minimum.

[0057] The deflection devices 5, 6, 7, 8, 9 and 10 can be designed as deflection arms in the form of cylindrical bolts, 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 arms 12, the film web 3 is deflected without contact or almost without contact with minimal friction against the outer surface of the respective pneumatic arm 12, forming an air cushion.

[0058] 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 discharge table can be seen in more detail in Fig. 5.

[0059] The folding bracket 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 fed to the Z-folding device 2, is arranged such that, in a vertical central position of the folding bracket 11, the film web 3 deflected by it, in its imaginary extension after deflection at the deflecting device 7, runs through the pivot axis SA of the folding bracket 11.

[0060] The vertical center position of the folding bracket 11 is marked here as 11”, while the extreme positions of the folding bracket 11 are marked 11”’ and a center position is marked 11’. The same applies to the deflection device 9 and 10 at the end of the folding bracket 11.

[0061] The film web 3 is folded into a stack 25 by the movement of the folding bracket 11 on the storage table, the film web 3 being fixed at the left end of the stack 25 and at the right end of the stack 25 after the end of each folding operation and before the start of the next folding operation by a hold-down device 26.

[0062] The folding bracket 11 is driven into a pivoting motion by the servomotors 16. The length FB of the retaining arms of the folding bracket 11 is preferably dimensioned such that they have 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 retaining arms of the folding bracket 11. The folding bracket 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 about the perpendicular axis of symmetry S and the central axis of the storage table.In the recognizable left-hand inversion position of the folding bracket 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. The folding bracket 11 is pivoted to such an extent that the film web 3 is deflected maximally at the deflection device 9 facing the axis of symmetry 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 folding bracket 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.

[0063] If the folding bracket 11 is moved clockwise to the intermediate 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 folding bracket 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 has the shortest length L3, 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. 5.During the further movement of the folding bracket 11 in a clockwise direction as it pivots to the central position shown at 11”, the film web 3 is applied to and deflected by the deflecting device 10 located furthest from the pivot axis S. In this central position of the folding bracket 11, the film web 3 runs in a vertical section of length L5 from the last deflecting device 7 to the deflecting device 10” of the folding bracket 11, and from the deflecting device 10” in a section of length L4 to the end of the film web 3 fixed to the hold-down device 26 on the stack 25. Thus, in this position of the folding bracket 11, the path of the film web 3 has a length L4 plus L5 from the deflecting device 7 to the hold-down device 26, which is longer than the shortest length L3 of the path of the film web 3 described above in position 11’ of the folding bracket 11.

[0064] 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 folding bracket 11, and then continuously increases again until the opposite reversal point is reached. Since the folding bracket 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.

[0065] This cyclically varying conveying speed and the associated change in web tension in the film web 3 is now compensated by a corresponding control of the movement of the dancer 19 with its deflection device 5 in the advance of the film web 3, so that the web tension change is ideally reduced to zero.

[0066] To minimize web tension changes caused by alterations in the length ratios described above during the web path of the film web 3 in the Z-folding device 2, the retaining arms of the folding bracket 11 have a length FB of 55 to 75 percent of the width B of the stack 25. This allows the additional length L2 of the film web path from the hold-down device 26 to the deflection device 9 of the folding bracket 11 in the reversed position to be reduced to the shortest possible length, which in turn reduces the overall length reduction to the shortest possible length L3. Furthermore, the pivot axis SA is positioned at a distance X from the folding plane of the stack 25, which is less than half the length FB of the retaining arms of the folding bracket 11, so that the folding bracket 11 with the deflection devices 9 and 10 pivots as close as possible to the folding plane.Furthermore, the swivel angle of the folding bracket 11 is at least 120 degrees, preferably at least 140 degrees, and particularly preferably at least 160 degrees. All of these dimensions contribute 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 reversed position of the folding bracket 11 is as short as possible, corresponding to the length L2, since this is crucial for the reduction in web path length from the position of the folding bracket 11 in the reversed position to reaching the position 11' of the folding bracket 11.

[0067] The proposed method of 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 compensates for the described change in length during the lead-in, 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 folding bracket 11, the control can be carried out according to a predefined program based on knowledge of the position of the folding bracket 11; a separate measuring device for determining the change in length is not required.

[0068] Furthermore, the web tension of the film web 3 is additionally detected by the measuring device shown in Fig. 3, formed by the load cells 23, immediately after it has exited the dancer 19, so that any remaining web tension fluctuations in the film web 3 are determined 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 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. 1 Conveyor device

[0069] 2 Z-folding device

[0070] 3 foil strips

[0071] 4 Clamping device

[0072] 5 Deflection device

[0073] 6 Deflection device

[0074] 7 Deflection device

[0075] 8 Deflection device

[0076] 9 Deflection device

[0077] 10 Deflection device

[0078] 11 folding bars

[0079] 12 pneumatic beams

[0080] 13 Distance sensor

[0081] 14 Scope section

[0082] 15 air cushions

[0083] 16 servo motor

[0084] 17 Cavity

[0085] 18 lateral surface area

[0086] 19 dancers

[0087] 20 lateral surface area

[0088] 21 Swivel arm

[0089] 22 Drive unit

[0090] 23 Load cell

[0091] 24 First funding phase

[0092] 25 stacks

[0093] 26 hold-down devices

[0094] A Extension angle

[0095] B width

[0096] FB Length L1 Length

[0097] L2 length

[0098] L3 length

[0099] L4 length L5 length

[0100] SA swivel axis

[0101] 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 -the conveying device (1) has a first conveying section (24) in which the conveying device (1) is designed to convey the film web (3) with a conveying speed that varies particularly cyclically, wherein -in the first conveying section (24) at least one deflection device (5,6,7,8,9,10) is provided for deflecting the film web (3), characterized in that -the deflection device (5,6,7,8,9,10) is designed as a compressed air beam (12) that can be connected to or is connected to a compressed air device, with an air-permeable circumferential section (14) for the exit of an airflow provided by the compressed air device.

2. Manufacturing device according to claim 1, characterized in that -the air-permeable circumferential section (14) is formed by a field of air outlet openings distributed in the circumferential and axial directions of the compressed air beam (12), limited in the circumferential and axial directions.

3. Manufacturing device according to claim 2, characterized in that -the compressed air beam (12) in the air-permeable circumferential section (14) has a porous material structure, wherein the air outlet openings are formed by the cross-sectional areas of spaces or pores of this porous material structure are formed on an outer surface of the compressed air beam (12).

4. Manufacturing apparatus according to one of claims 2 or 3, characterized in that -the compressed air beam (12) has continuous compressed air channels in the air-permeable circumferential section (14), wherein -the air outlet openings are formed by the cross-sectional areas of these compressed air channels on an outer surface of the compressed air beam (12).

5. Manufacturing apparatus according to one of claims 2 to 4, characterized in that -the air outlet openings each have an average cross-sectional area of ​​0.004 to 0.1 mm² 2 preferably from 0.01 to 0.06 mm 2 , particularly preferably from 0.02 to 0.04 mm 2 exhibit.

6. Manufacturing apparatus according to one of claims 2 to 5, characterized in that -the air outlet openings together constitute an area share of 20 to 80 percent, preferably 40 to 60 percent, particularly preferably 45 to 55 percent of the total area of ​​the air-permeable circumferential section (14).

7. Manufacturing device according to one of claims 1 to 6, characterized in that -the extension angle (A) of the air-permeable circumferential section (14) in the circumferential direction of the pneumatic tube (12) corresponds at least to the intended wrapping angle of the film web (3) on the pneumatic tube (12).

8. Manufacturing device according to one of claims 1 to 7, characterized in that -the compressed air device is set up and designed to apply an air pressure of 1.1 to 1.5 bar to the compressed air shaft (12).

9. Manufacturing device according to one of claims 1 to 8, characterized in that -the compressed air device is set up and designed to supply the compressed air shaft (12) with a volume flow of 40 to 100 l / min, preferably 70 to 100 l / min, particularly preferably 70 to 80 l / min.

10. Manufacturing device according to one of claims 1 to 9, characterized in that -the conveying device (1) has a dancer (19) with a deflecting device (5) for the film web (3) movable transversely to the conveying direction of the film web (3), wherein the dancer (19) separates the first conveying section (24) from a second conveying section arranged upstream in relation to the conveying direction of the film web (3).

11. Manufacturing device according to one of claims 1 to 10, characterized in that -in the first conveying section (24) a Z-folding device (2) for Z-folding the film web (3) on a storage table with a deflecting device that can be moved back and forth is provided.

12. Manufacturing apparatus according to claims 10 and 11, characterized in that -the dancer (19) can be controlled depending on the change in length of the foil web (3) caused by the movement of the deflection device of the Z-folding device (2).

13. Manufacturing device according to claim 12, characterized in that -the conveying device (1) has a deflecting device (7) at which the film web (3) is deflected directly to the Z-folding device (2), and -the change in length of the web path of the film web (3) is formed by the changing length (L1 ,L2,L3,L4,L5) of the web path of the film web (3) between the deflecting device (7) and the delivery table.

14. Manufacturing apparatus according to one of claims 10 to 13, characterized in that -a measuring device for detecting the web tension of the film web (3) is provided between the Z-folding device (2) and the dancer (19) or on the dancer (19), and -the movement of the dancer's deflection device (19) is controllable and / or adjustable depending on the web tension detected by the measuring device.

15. Manufacturing apparatus according to one of claims 11 to 14, characterized in that -between the dancer (19) and the Z-folding device (2) a plurality of deflection devices (6,7,8) are provided, all of which are designed as pneumatic beams (12).

16. Manufacturing apparatus according to one of claims 11 to 15, characterized in that -the deflection device of the Z-folding device (2) comprises a folding bracket (11) pivoting about a pivot axis (SA) with two retaining arms and two deflection devices (9, 10) arranged parallel to each other at the ends of the retaining arms between the retaining arms of the folding bracket (11), between which the film web (3) is guided, wherein -the folding bracket (11) can be driven by means of a drive device to fold the film web (3) into a stack (25) in a periodic pivoting movement about a pivoting axis (SA) from a first reversal point to a second reversal point and vice versa.

17. Manufacturing device according to claim 16, characterized in that -the film web (3) in the conveying device (1) is deflected at a deflecting device (7) in the direct conveying to the Z-folding device (2), wherein -the deflection device (7) is arranged such that the film web (3) starting from the deflection device (7) in a central position of the folding bracket (11) is aligned from the deflection device (7) to the folding bracket (11) so that it runs in its imaginary extension through the pivot axis (SA) of the folding bracket (11).

18. Manufacturing apparatus according to one of claims 16 or 17, characterized in that -the folding bracket (11) extending from the first turning point to the second turning point at an angle of at least 120 degrees, preferably at least 140 degrees, particularly preferably at an angle of at least 160 degrees It is swivel-mounted.

19. Manufacturing apparatus according to one of claims 16 to 18, characterized in that -the retaining arms of the folding bracket (11) have a length (FB) extending from the pivot axis (SA) to the deflection devices (9,10) which corresponds to 55 to 75 percent of the width (B) of the stack (25) to be folded.

20. Manufacturing apparatus according to one of claims 16 to 19, characterized in that -the folding bracket (11) can be pivoted about a pivot axis (SA) which has a distance (X) to a folding plane of the stack (25) that is less than half the length (FB) of the folding bracket (11).

21. Arrangement comprising a manufacturing device according to one of claims 1 to 20 comprising a film web (3) arranged therein.

22. Arrangement according to claim 21, characterized in that the foil web (3) is designed as a separator web of a battery cell.

23. Method for controlling a manufacturing device with the features of any one of claims 1 to 9, characterized in that -in the conveying device (1) a dancer (19) is provided with a deflecting device (5) for the film web (3) which is movable transversely to the conveying direction of the film web, wherein the dancer (19) is controlled in its movement by the deflecting device (5) for controlling the web tension in the film web (3). is controlled and / or regulated.

24. Method according to claim 23, characterized in that - in the first conveying section (24) a Z-folding device (2) for Z-folding the film web (3) on a delivery table with a deflecting device movable back and forth is provided, and -the dancer (19) is controlled depending on the change in length of the web path of the film web (3) in the Z-folding device (2) or in the conveying device (1) caused by the movement of the Z-folding device (2).

25. Method according to claim 24, characterized in that a deflecting device (7) is provided in the conveying device (1) at which the film web (3) is deflected directly to the Z-folding device (2), and -the underlying change in length of the web path of the film web (3) is formed by the changing length (L1 ,L2,L3,L4,L5) of the web path of the film web (3) between the deflecting device (7) and the delivery table.

26. Method according to one of claims 24 or 25, characterized in that -a measuring device detecting the web tension of the film web (3) is provided between the first conveying section (24) and the dancer (19) or on the dancer (19), and -the movement of the deflecting device (5) of the dancer (19) is controlled and / or regulated in its orientation depending on the web tension detected by the measuring device.

27. Method according to claim 26, characterized in that the film web (3) is deflected at a deflection section of a deflection device (8), which is mounted at two ends enclosing the deflection section, and the measuring device is formed by two load cells (23), wherein one load cell (23) is assigned to each end of the deflection device (8).

28. Method according to one of claims 23 to 27, characterized in that -the web tension in the film web (3) is controlled and / or regulated to a value of 10 + / - 2 N.

29. Pneumatic beam (12) for use as a deflection device in a manufacturing device according to the preamble of claim 1, characterized in that the pneumatic beam (12) has an air-permeable circumferential section (14).

30. Compressed air beam (12) according to claim 29, characterized in that -the air-permeable circumferential section (14) is formed by a field of air outlet openings distributed in the circumferential and axial directions of the compressed air beam (12), limited in the circumferential and axial directions.

31. Compressed air beam (12) according to claim 30, characterized in that -the air outlet openings each have an average cross-sectional area of ​​0.004 to 0.1 mm² 2 preferably from 0.01 to 0.06 mm 2 , particularly preferably from 0.02 to 0.04 mm 2 exhibit.

32. Compressed air beam (12) according to one of claims 30 or 31, characterized in that -the air outlet openings together constitute an area share of 20 to 80 percent, preferably 40 to 60 percent, particularly preferably 45 to 55 percent of the total area of ​​the air-permeable circumferential section (14).

33. Compressed air beam (12) according to one of claims 30 to 32, characterized in that -the compressed air beam (12) has a porous material structure in the air-permeable circumferential section (14), wherein -the air outlet openings are formed by the cross-sectional areas of spaces or pores of this porous material structure on an outer surface of the compressed air beam (12).

34. Compressed air beam (12) according to one of claims 30 to 32, characterized in that -the compressed air beam (12) has continuous air pressure channels in the air-permeable circumferential section (14), and -the air outlet openings are formed by the cross-sectional areas of these air pressure channels on an outer surface of the compressed air beam (12).

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