Positioning method, welding method, and welding apparatus

Abstract

The present invention provides a positioning method, a welding method, and a welding apparatus that enable high-precision positioning when welding a workpiece and a film in a specific area. [Solution] The positioning method according to this disclosure is performed by a welding device 1 that includes a first roller for feeding a workpiece W0 and a second roller for feeding a film F0, and welds the workpiece and the film in a specific area. First, the welding device 1 corrects the meandering of the workpiece W0 by changing the inclination of the first roller based on the position of the workpiece W0. Then, the welding device 1 determines the supply position of the film F1 to the workpiece W1 based on the position of the workpiece W1 in the corrected state. Then, the welding device 1 corrects the meandering of the film F0 by changing the inclination of the second roller based on the position of the film F0.

Description

Technical Field

[0001] The present disclosure relates to a positioning method, a welding method, and a welding apparatus.

Background Art

[0002] Patent Document 1 describes a technique of joining a web-shaped protective film supplied from a roll to a web-shaped electrolyte membrane supplied from the same roll and thermocompression bonding them with a roller.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, Patent Document 1 only describes the positioning by roll control on the film side among the two materials supplied from the rolls, and there is room for improvement in positioning. In particular, in a welding process of welding a workpiece and a film in a specific region by laser welding or the like, higher-precision positioning is required, but the technique described in Patent Document 1 cannot meet such a requirement.

[0005] Thus, when welding a workpiece and a film in a specific region, the development of a technique for performing positioning with high precision is desired.

Means for Solving the Problems

[0006] The positioning method according to this disclosure is a welding apparatus comprising a first roller for feeding a workpiece and a second roller for feeding a film, which welds the workpiece and the film in a specific area. Based on the position of the workpiece, the welding apparatus corrects the meandering of the workpiece by changing the inclination of the first roller, then determines the supply position of the film to the workpiece based on the position of the workpiece after the meandering has been corrected, and then corrects the meandering of the film by changing the inclination of the second roller based on the position of the film.

[0007] The welding method according to this disclosure involves the welding apparatus overlapping the workpiece and the film, which have been positioned by the positioning method, and welding them together while irradiating a specific area from the film side with laser light.

[0008] The welding apparatus according to this disclosure comprises: a first roller for feeding a workpiece; a second roller for feeding a film; a welding unit for welding the workpiece and the film in a specific area; a position detection unit for detecting the position of the workpiece and the position of the film; and a meandering correction unit that corrects the meandering of the workpiece by changing the inclination of the first roller based on the position of the workpiece, then determines the supply position of the film to the workpiece based on the position of the workpiece in the corrected state, and then corrects the meandering of the film by changing the inclination of the second roller based on the position of the film. [Effects of the Invention]

[0009] According to this disclosure, it is possible to provide a positioning method, a welding method, and a welding apparatus that enable high-precision positioning when welding a workpiece and a film in a specific area. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic perspective view showing an example configuration of a welding apparatus that performs the positioning method according to an embodiment of the present disclosure. [Figure 2]Figure 1 is a schematic cross-sectional view showing an example of the welding process performed by the welding apparatus. [Figure 3] This is a flowchart illustrating an example of a welding method including a positioning method according to an embodiment of the present disclosure. [Figure 4] This is a schematic perspective view showing the workpiece transport method related to the comparative example. [Figure 5] This is a schematic cross-sectional view showing the heat input process related to the comparative example. [Modes for carrying out the invention]

[0011] The present invention will be described below through embodiments of the invention, but the invention as claimed is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means for solving the problem.

[0012] (Embodiment) The positioning method according to this embodiment is a method performed by a welding apparatus. The positioning method will be described below along with a description of the welding apparatus.

[0013] Using Figure 1, an example of the configuration of a welding apparatus that performs the positioning method according to this embodiment will be explained. Figure 1 is a schematic perspective view showing an example of the configuration of this welding apparatus.

[0014] As shown in Figure 1, the welding apparatus 1 according to this embodiment may include a roller 11, rollers 12b, 12c, 12d, 12e, and a welding section 20.

[0015] Roller 11 is an example of a first roller that feeds out the workpiece W0. The workpiece W0 can be, for example, a web-shaped workpiece. The workpiece W0 can be, for example, wound on a roll (not shown). In this case, roller 11 will feed the workpiece W0 unwound from this roll to the next stage.

[0016] In addition, the first roller provided in the welding apparatus 1 for feeding out the work W0 may be provided at appropriate positions in addition to the roller 11. The first roller only needs to be arranged so that it can feed out the work W0 toward the confluence point with the film F0, and its arrangement, configuration, and size are not limited. Note that the roller 11 may be a pair of rollers that sandwich the work W0.

[0017] The rollers 12b, 12c, 12d, and 12e are an example of the second roller for feeding out the film F0. Note that the rollers 12b, 12c, 12d, and 12e may each be a pair of rollers that sandwich the film F0.

[0018] In addition, the welding apparatus 1 can include a roll 12a around which the film F0 is wound around its feeding shaft. The film F0 is fed out from the roll 12a, passes through the rollers 12b, 12c, and 12d in sequence, and is fed out toward the roller 12e. The roller 12e is a roller arranged at the confluence point with the work W0. Although not shown, the welding apparatus 1 includes a winder for winding up the work with the film after welding or a tractor for pulling the work with the film after welding, and the film F0 and the work W0 can be fed by the tension from the winder or the tractor.

[0019] The roll 12a and the rollers 12b, 12c, and 12d constitute a film supply unit 12 for supplying the film F0. Although the film supply unit 12 is not shown so as to be located above the work W0 for convenience, all or a part of the downstream side of the film supply unit 12 may be arranged to be located above the work W0 in the same manner as the roller 12e.

[0020] And the welding apparatus 1 includes a welding unit 20 that welds the work W0 and the film F0 in a specific region. The work W0 and the film F0 are welded by the welding unit 20 in a specific region such as one width-direction end region SA of the work W0 after merging at the confluence point. The specific region may be referred to as a processing region.

[0021] Hereinafter, the workpiece W0 after confluence is referred to as workpiece W1, and the film F0 after confluence is referred to as film F1. Also, in the example of FIG. 1, since the film F1 is welded to the workpiece W1, the line for transporting the workpieces W0 and W1 is referred to as the main line, and the line for transporting the films F0 and F1 is referred to as the sub-line for explanation. The meandering of the workpiece can include the case where the width direction of the workpiece is not perpendicular but inclined with respect to the transport direction of the main line. The meandering of the film can include the case where the width direction of the film is not perpendicular but inclined with respect to the transport direction of the sub-line.

[0022] Also, the specific region may be the end regions in the width direction on both sides of the workpiece W1. In that case, it is preferable to provide a film supply unit for supplying the other film F0 not shown and a roller at the confluence point such as the roller 12e. Alternatively, the specific region may be the entire region in the width of the workpiece W1. In that case, the welding device may be configured to supply a film F0 wider than the width of the workpiece W0, merge the film F0 across the width of the workpiece W0, and weld the entire workpiece W1 after confluence and the film F1.

[0023] Hereinafter, an example where the specific region is the end region SA in the width direction on one side of the workpiece W1 will be described. The welding unit 20 can include, for example, a laser irradiator 18 and a pressure roller 19. In this example, the laser irradiator 18 irradiates the film F1 and the workpiece W1 after confluence with a laser, and then presses with the pressure roller 19.

[0024] The welding method in the welding unit 20 is not limited to the laser welding method as exemplified, and various other welding methods may be adopted. The welding unit 20 only needs to be able to weld the workpiece sent out from the first roller, the film sent out from the second roller, and them in a specific region.

[0025] Furthermore, the shapes of the workpiece W0 and film F0 are acceptable as long as they can be fed out by the rollers. The materials of the workpiece W0 and film F0 are acceptable as long as they can be welded to each other. The welding method at the welding section 20 should be an appropriate method depending on the materials of the workpiece W0 and film F0.

[0026] The welding apparatus 1 includes a position detection unit that detects the position of the workpiece and the position of the film, and a meandering correction unit that corrects the meandering of the workpiece W0 and the meandering of the film F0. The position detection unit detects the position that will be used as the basis for meandering correction in the meandering correction unit and passes position information indicating that position to the meandering correction unit. Hereinafter, the position information passed will also be simply referred to as position. Based on the positions of the workpiece and film input from the position detection unit, the meandering correction unit corrects the meandering of the workpiece W0 and the film F0 by changing the inclination of the first roller and the second roller. The position detection unit and the meandering correction unit will be described in detail below.

[0027] The position detection unit detects the position of one or both widthwise edges of the workpiece W0 and the position of one or both widthwise edges of the film F0. The position detection unit also detects the position of one or both widthwise edges of the workpiece W1. The position detection unit may also detect the position of one or both widthwise edges of the film F1. The position detection unit is exemplified by the first position detection unit 13, the second position detection unit 14, and the third position detection unit 15, which are described below. The first position detection unit 13, the second position detection unit 14, and the third position detection unit 15 can all be composed of optical sensors or the like.

[0028] The first position detection unit 13 detects the position of the outermost edge on the widthwise end region SA side of the workpiece W0. Therefore, the first position detection unit 13 is configured and arranged to detect the edge SEa on the widthwise end region SA side of the workpiece W0 by measuring the distance of an area such as the detection region 13A shown in Figure 1. Since the width of the workpiece W0 is known at the time of manufacturing, the first position detection unit 13 may also be configured and arranged to detect the other edge SEb of the workpiece W0. Of course, the first position detection unit 13 may also be configured and arranged to detect both edges SEa and SEb of the workpiece W0. For convenience, in Figure 1, both edges SEa and SEb are represented by extensions of the actual edges of the workpiece W0.

[0029] The second position detection unit 14 detects the position of the outermost edge on the widthwise end region SA side of the workpiece W1 after meandering correction has been applied to the workpiece W0. Therefore, the second position detection unit 14 is configured and arranged to detect the edge SEa on the widthwise end region SA side of the workpiece W1 by measuring the distance of an area such as the detection region 14A shown in Figure 1. Since the width of the workpiece W1 is known at the time of manufacturing, the second position detection unit 14 may also be configured and arranged to detect the other edge SEb of the workpiece W1. Of course, the second position detection unit 14 may also be configured and arranged to detect both edges SEa and SEb of the workpiece W1. The positions before and after meandering correction of the workpiece may be detected at different positions as described above, but the workpiece W0 before correction may be detected at a position where the position of the corrected workpiece W1 can be detected.

[0030] The third position detection unit 15 detects the position of one or both widthwise edges of the film F0. Therefore, the third position detection unit 15 is configured and positioned to detect one or both edges of the film F0 by measuring the distance of an area such as the detection area 15A shown in Figure 1. Furthermore, for verification of meandering correction, the third position detection unit 15 may also detect the position of one or both widthwise edges of the film F1 after meandering correction has been applied. The positions before and after meandering correction of the film may be detected at the same position, or at different positions. Also, since the width of the film F0 is known during manufacturing, when detecting one edge of the film F0, the supply position of the film F1 to the workpiece W1 can be determined as described later, regardless of which side's edge is detected.

[0031] The meandering correction unit corrects the meandering of the workpiece W0 and the meandering of the film F1 before they merge at the roller 12e. The corrected workpiece W1 and the corrected film F1 then merge at the roller 12e.

[0032] The meandering correction unit may include, for example, a first correction control unit 16 and a main line meandering correction mechanism controlled by it, and a second correction control unit 17 and a sub-line meandering correction mechanism controlled by it. Of course, the first correction control unit 16 and the second correction control unit 17 can be mounted on the welding apparatus 1 as a single correction control unit.

[0033] The first correction control unit 16 controls the meandering of the workpiece W0 being transported on the main line based on the position detected by the first position detection unit 13. The first correction control unit 16 may also be called the main line meandering correction control unit. The main line meandering correction mechanism to be controlled by it can be a mechanism that changes the inclination of the roller 11 included in the transport mechanism that transports the workpiece W0. The inclination of the roller 11 can be defined as the difference in height of the rotation axis at both ends of the roller 11 in Figure 1. In other words, the main line meandering correction mechanism can be a mechanism that changes the height of one or both end faces of the roller 11. Due to the correction by the first correction control unit 16, the workpiece W1 is transported on the main line in a state that is centered in the width direction.

[0034] The second correction control unit 17 performs control to correct the meandering of the film F0 being transported on the sub-line based on the position of the workpiece W1 detected by the second position detection unit 14 and the position of the film F0 detected by the third position detection unit 15. The second correction control unit 17 may also be called the sub-line meandering correction control unit.

[0035] The subline meandering correction mechanism controlled by the second correction control unit 17 can be a mechanism that changes the inclination of one or more of the rollers 12b, 12c, and 12d included in the transport mechanism that transports the film F0. Taking roller 12b as an example, the inclination of roller 12b can be defined as the difference in height of the rotation axis at both ends of roller 12b in Figure 1. In other words, the subline meandering correction mechanism can be a mechanism that changes the height of one or both end faces of roller 12b.

[0036] Let me explain in more detail. The second correction control unit 17 determines the supply position of the film F1 to the workpiece W1 based on the edge position of the workpiece W1 in the state where meandering has been corrected. The determined supply position is the position of the film F1 relative to the workpiece W1 in the width direction, and is the position of the edge of the film F1 relative to the edge of the workpiece W1. The edge position of the workpiece W1 is detected by the second position detection unit 14.

[0037] Next, the second correction control unit 17 corrects the meandering of the film F0 by changing the inclination of the second rollers, exemplified by rollers 12b, 12c, 12d, etc., based on the edge position of the film F0 detected by the third position detection unit 15. This correction means moving the supply position to match the determined supply position. This correction enables the film F1 to be supplied to the workpiece W1 at the aforementioned supply position.

[0038] Alternatively, the second correction control unit 17 may first calculate the supply position of the film F1 to the workpiece W1 based on the edge position of the workpiece W0 before meandering correction, and then correct that supply position based on the edge position of the workpiece W1 after meandering correction. In this case, the second correction control unit 17 may correct the meandering of the film F0 by changing the inclination of the second roller to match the corrected supply position based on the edge position of the film F0 detected by the third position detection unit 15.

[0039] After this meandering correction, the welding section 20 performs welding. In other words, the welding section 20 overlaps the workpiece W1, which is the workpiece W0 after meandering correction, with the film F1, which is the film F0 after meandering correction, and welds a specific area, such as the widthwise end region SA of one side of the workpiece W1.

[0040] Figure 2 illustrates an example of the welding process performed by a welding device. Figure 2 is a schematic cross-sectional view showing an example of this welding process.

[0041] The workpiece W1 and film F1, positioned according to the positioning method described above, are overlapped at the roller 12e which serves as the merging point, and the laser irradiator 18 irradiates a specific area of ​​the film F1 from the film F1 side while the pressure roller 19 welds them together.

[0042] Specifically, as illustrated in state 21, when laser light LA ​​is irradiated from the film F1 side, the laser light LA ​​passes through the transparent material, film F1, and is absorbed by the absorbent workpiece W1. Due to this absorption, as illustrated in state 22, the area of ​​workpiece W1 irradiated by the laser light LA ​​generates heat, becoming a heated area HE. In this way, the laser irradiator 18 irradiates the film F1, which is supplied from the subline, with laser light of a wavelength that does not penetrate and heat the film, thereby heating the absorbent and heat being applied only to the interface to be welded.

[0043] Subsequently, as illustrated in state 23, when the film F1 and workpiece W1 are transported to the position of the pressure roller 19, the pressure roller 19 applies pressure from above the film F1 toward the workpiece W1, and heat conduction occurs in the direction indicated by the upward arrow, transferring heat to the film F1. As a result, as illustrated in state 24, the heat-generating region HE reaches the film F1 side, and the film F1 melts. Finally, as illustrated in state 25, due to the pressure of the pressure roller 19 and the passage of time, the heat-generating region HE cools and compacts to become the welded region SE, and the film F1 and workpiece W1 are welded together.

[0044] Next, an example of a welding method including the positioning method according to this embodiment will be explained using Figure 3. Figure 3 is a flowchart illustrating this example of a welding method.

[0045] First, the first position detection unit 13 detects the position of the workpiece W0 (step S1). Next, the first correction control unit 16 corrects the meandering of the workpiece W0 by changing the inclination of the first roller, exemplified by the roller 11, based on the position of the workpiece W0 (step S2). Then, the second position detection unit 14 detects the position of the workpiece W1, which is the workpiece W0 after meandering correction (step S3).

[0046] Based on the position of the workpiece W1 after the meandering has been corrected, the second correction control unit 17 determines the supply position of the film F1 relative to the workpiece W1 (step S4). Then, the third position detection unit 15 detects the position of the film F0 (step S5). Based on the detected position of the film F0, the second correction control unit 17 changes the inclination of the second roller, exemplified by roller 12b, etc., to correct the meandering of the film F0 to match the determined supply position (step S6). Correcting the meandering of the film F0 means moving the supply position to the determined supply position.

[0047] Then, the roller 12e brings together the workpiece W1 after meandering correction and the film F1 after meandering correction, and the welding section 20 welds the workpiece W1 after meandering correction and the film F1 after meandering correction together (step S7), thus ending the process.

[0048] Furthermore, in this embodiment, when merging the workpiece and film and welding them only in a specific area, the web-shaped workpiece and film are fed continuously, so it is preferable to constantly detect the positions of the widthwise edges of the workpiece and the widthwise edges of the film while the welding process is in progress. In this embodiment, first the meandering of the workpiece is corrected using the position of the workpiece, and then the meandering of the film is corrected using the corrected positions of the workpiece and the film, and then they are merged. Therefore, according to this embodiment, when welding the workpiece and film in a specific area, high-precision positioning can be achieved.

[0049] To explain the above-mentioned effects and further effects of this embodiment, a welding method according to a comparative example will be described using Figures 4 and 5. Figure 4 is a schematic perspective view showing the workpiece transport method according to the comparative example. Figure 5 is a schematic cross-sectional view showing the heat input process according to the comparative example.

[0050] In the welding method according to the comparative example, as shown in Figure 4, a rectangular sheet of workpiece W4 is chucked and transported by a robot 40, its position is corrected by cameras 45 and 46, and the films F4a and F4b are welded together one side at a time using a contact-type hot iron. The robot 40 comprises a main body 41 including a control unit, an arm base 42 installed on the main body 41, an arm 43 installed on the arm base 42, and a chuck unit 44 that chucks the workpiece W4 by suction. In this welding process, as shown in Figure 5, the film F4a or F4b and the workpiece W4 are sandwiched between the upper part 51u of the hot iron equipped with a heating unit 52 and the lower part 51d of the hot iron, and heat is applied from the film F4a or F4b side by the heating unit 52 to perform welding. Note that heat may also be applied from the workpiece W4 side.

[0051] In the welding method described in the comparative example, if the workpiece W4 is large and thin rectangular, it takes time for the robot 40 to chuck it using air suction. In contrast, in this embodiment, processing is performed on the web transport, so there is no need to pick up the workpiece.

[0052] Furthermore, in the welding method of the comparative example, heat is applied from outside the film using a hot iron, so it takes time for the heat to transfer to the welding surface, resulting in a long welding time. Also, in the welding method of the comparative example, if the hot iron is removed while still hot, the film will fuse to the hot iron, so it is necessary to cool and solidify it, and this cooling time also contributes to the long welding time. In contrast, in this embodiment, heat is applied instantaneously by a laser and cooled instantly, so welding does not take time and processing can be performed continuously on the web transport. In addition, in this embodiment, since heat is applied only to the welding interface, there is no risk of the film fusing to the compacting roller, and the workpiece can be fed at high speed.

[0053] Furthermore, in the welding method of the comparative example, positional correction is performed by looking at a representative point, so the positional accuracy is not high throughout the entire area. More specifically, in the welding method of the comparative example, the positions of both ends of one side are detected and the position is aligned with the long side, so the positional accuracy other than the ends is affected by the tolerances caused by the product, and it cannot be said that the positional accuracy is high throughout the entire area. In contrast, in this embodiment, the edge position of the main line is constantly detected throughout the entire area, and furthermore, the edge position of the sub-line is also constantly detected, so the film can be supplied and processed with high accuracy throughout the entire area.

[0054] As described above, in this embodiment, a web-shaped workpiece is continuously fed on the main line, and a film is joined from the sub-line with high precision alignment, and welding is performed continuously. In this embodiment, the position of the main line is detected in advance, and the supply position of the sub-line is also known, so the joining position is controlled to supply the film, and heat is applied to it in a short time using a laser to perform welding. As a result, in this embodiment, high-precision position control is achieved compared to the comparative example, continuous processing is possible, and the film can be welded at high speed.

[0055] Furthermore, the positioning and welding methods described above may be used in the manufacture of electrode sheets for lithium-ion batteries. In this case, the manufactured electrode sheet will consist of a film as exemplified by film F1 and a workpiece as exemplified by workpiece W1. While a detailed explanation of the film and workpiece included in this electrode sheet is omitted, their shapes and materials are acceptable as long as they can function as an electrode sheet and can be welded to one another.

[0056] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. For example, the positioning method and welding method according to the above embodiments can be applied to various fields other than the manufacture of electrode sheets for lithium-ion batteries. [Explanation of Symbols]

[0057] 1 Welding device, 11 Roller, 12 Film supply unit, 12a Roll, 12b, 12c, 12d, 12e Rollers, 13 First position detection unit, 13A, 14A, 15A Detection area, 14 Second position detection unit, 15 Third position detection unit, 16 First correction control unit, 17 Second correction control unit, 18 Laser irradiator, 19 Pressure roller, 20 Welding unit, F0, F1 Film, SA Width direction edge area, SEa, SEb Edge, W0, W1 Workpiece

Claims

1. A welding apparatus comprising a first roller for feeding a workpiece and a second roller for feeding a film, which welds the workpiece and the film in a specific area, Based on the position of the workpiece, the inclination of the first roller is changed to correct the meandering of the workpiece. Subsequently, based on the position of the workpiece after the meandering has been corrected, the supply position of the film to the workpiece is determined. Subsequently, the inclination of the second roller is changed based on the position of the film to correct the meandering of the film. Positioning method.

2. A positioning method according to claim 1, used in the manufacture of electrode sheets for lithium-ion batteries.

3. The welding apparatus welds the workpiece and the film, which have been positioned by the positioning method described in claim 1 or 2, while irradiating the specific region with laser light from the film side. Welding method.

4. The first roller that sends out the work, The second roller that feeds the film, A welding section that welds the workpiece and the film in a specific area, A position detection unit for detecting the position of the workpiece and the position of the film, A meandering correction unit that corrects the meandering of the workpiece by changing the inclination of the first roller based on the position of the workpiece, then determines the supply position of the film to the workpiece based on the position of the workpiece in the corrected state, and then corrects the meandering of the film by changing the inclination of the second roller based on the position of the film, A welding device equipped with the following features.

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