Positioning method, welding method and welding device

Abstract

This invention provides a positioning method, welding method, and welding apparatus capable of high-precision positioning when welding a workpiece and a film in a specific area. The positioning method is performed by a welding apparatus comprising a first roller for feeding the workpiece and a second roller for feeding the film, and for welding the workpiece and film in a specific area. First, the welding apparatus corrects workpiece serpentine movement by adjusting the inclination of the first roller according to the workpiece's position. Then, the welding apparatus determines the film's supply position relative to the workpiece based on the corrected position of the workpiece. Finally, the welding apparatus corrects film serpentine movement by adjusting the inclination of the second roller according to the film's position.

Description

Technical Field

[0001] This invention relates to a positioning method, a welding method, and a welding apparatus. Background Technology

[0002] Patent Document 1 describes a technique for merging a strip of electrolyte membrane supplied from a roll with a strip of protective membrane also supplied from a roll, and then hot-pressing them together using rollers.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2011-028915 Summary of the Invention

[0004] However, Patent Document 1 only describes the positioning of the two materials supplied from the roll based on the film side of the roll control, leaving room for improvement in positioning. In particular, in welding processes such as laser welding that weld the workpiece and the film in a specific area, higher precision positioning is required, but the technology described in Patent Document 1 cannot meet this requirement.

[0005] Therefore, when welding workpieces and films in specific areas, it is desirable to develop a technology for high-precision positioning.

[0006] The positioning method of the present invention includes 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. The apparatus performs the following processing: The tilt angle of the first roller is changed according to the position of the workpiece to correct the workpiece's serpentine movement; then, the supply position of the film relative to the workpiece is determined based on the position of the workpiece after the serpentine movement has been corrected; then, the tilt angle of the second roller is changed according to the position of the film to correct the film's serpentine movement.

[0007] In the welding method of the present invention, the welding device overlaps the workpiece and the film positioned by the positioning method, and performs welding while irradiating the specific area from the film side with a laser beam.

[0008] The welding apparatus of the present invention comprises: a first roller for feeding a workpiece; a second roller for feeding a film; a welding section for welding the workpiece and the film in a specific area; a position detection section for detecting the position of the workpiece and the position of the film; and a serpentine correction section for correcting the serpentine movement of the workpiece by changing the inclination of the first roller according to the position of the workpiece, then determining the supply position of the film relative to the workpiece based on the position of the workpiece after correcting the serpentine movement, and then correcting the serpentine movement of the film by changing the inclination of the second roller according to the position of the film.

[0009] Invention Effects

[0010] According to the present invention, a positioning method, a welding method, and a welding apparatus are provided that can perform high-precision positioning when welding workpieces and films in a specific area. Attached Figure Description

[0011] Figure 1 This is a schematic perspective view showing a structural example of a welding apparatus for performing the positioning method according to an embodiment of the present invention.

[0012] Figure 2 It means by Figure 1 A schematic cross-sectional view of an example of the state of a welding process performed by a welding device.

[0013] Figure 3 This is a flowchart illustrating an example of a welding method that includes the positioning method according to embodiments of the present invention.

[0014] Figure 4 This is a schematic perspective view showing the method of handling the workpiece involved in the comparative example.

[0015] Figure 5 This is a schematic cross-sectional view showing the state of the heat input process involved in the comparative example. Detailed Implementation

[0016] The present invention will now be described through embodiments thereof, but the invention involved in the technical solution is not limited to the following embodiments. Furthermore, not all the configurations described in the embodiments are necessarily necessary as means to solve the problem.

[0017] (Implementation Method)

[0018] The positioning method described in this embodiment is a method performed by a welding apparatus. Hereinafter, the welding apparatus will be described along with the positioning method.

[0019] use Figure 1 An example of the structure of a welding apparatus for performing the positioning method according to this embodiment will be described. Figure 1 This is a schematic perspective view showing a structural example of the welding device.

[0020] like Figure 1 As shown, the welding apparatus 1 according to this embodiment can include rollers 11, rollers 12b, 12c, 12d, 12e and welding section 20.

[0021] Roller 11 is an example of the first roller for feeding workpiece W0. Workpiece W0 can be, for example, a strip-shaped workpiece. Workpiece W0 can be, for example, a workpiece wound on a drum (not shown). In this case, roller 11 will feed the workpiece W0 from the drum to the next section.

[0022] Furthermore, the first roller provided in the welding apparatus 1 for feeding out the workpiece W0 can be provided at any other suitable location besides roller 11. The first roller is only required to be configured to feed the workpiece W0 toward the point of convergence with the film F0; its configuration, structure, and size are not limited. Alternatively, roller 11 can also be a pair of rollers that clamp the workpiece W0.

[0023] Rollers 12b, 12c, 12d, and 12e are examples of the second rollers that deliver the film F0. Alternatively, rollers 12b, 12c, 12d, and 12e can also be configured as a pair of rollers that hold the film F0.

[0024] Furthermore, the welding apparatus 1 can include a roll 12a with a film F0 wound around the feed shaft. The film F0 is fed out from the roll 12a, passing sequentially through rollers 12b, 12c, and 12d towards roller 12e. Roller 12e is a roller disposed at the confluence point with the workpiece W0. Although not shown, the welding apparatus 1 includes a winding machine for winding the welded workpiece with the film or a traction machine for pulling the welded workpiece with the film, and the film F0 and workpiece W0 can be fed out by the tension of the winding machine or the traction machine.

[0025] The roll 12a and rollers 12b, 12c, and 12d constitute the film supply section 12 for supplying the film F0. Although for convenience, the film supply section 12 is not shown as being located above the workpiece W0, all or part of the downstream side of the film supply section 12 may be configured to be located above the workpiece W0, as with roller 12e.

[0026] Furthermore, the welding apparatus 1 includes a welding section 20 for welding workpiece W0 and film F0 in a specific area. After workpiece W0 and film F0 merge at the merging point, they are welded together in a specific area, such as the end region SA of workpiece W0 in one width direction, through the welding section 20. This specific area may also be referred to as the processing area.

[0027] Hereinafter, the workpiece W0 after merging will be referred to as workpiece W1, and the thin film F0 after merging will be referred to as thin film F1. Furthermore, in Figure 1 In the example, since the film F1 is fused to the workpiece W1, the line conveying workpieces W0 and W1 is referred to as the main conveyor line, and the line conveying films F0 and F1 is referred to as the sub-conveyor line. Workpiece serpentination can include cases where the workpiece's width direction is not perpendicular to the conveying direction of the main conveyor line but is conveyed at an angle. Film serpentination can also include cases where the film's width direction is not perpendicular to the conveying direction of the sub-conveyor line but is conveyed at an angle.

[0028] Furthermore, the specific area can be the two width-direction end regions of the workpiece W1. In this case, a film supply section for supplying another film F0 (not shown) and a merging point roller such as roller 12e can be provided. Alternatively, the specific area can be the entire width region of the workpiece W1. In this case, the welding device only needs to be configured as follows: supplying a film F0 wider than the width of the workpiece W0, causing the film F0 to merge with the entire width of the workpiece W0, and fusing the merged workpiece W1 and the film F1.

[0029] The following description focuses on an example of a specific region, namely, the end region SA of the workpiece W1 in the width direction. The welding section 20 may include, for example, a laser irradiator 18 and a pressure roller 19.

[0030] In this example, the laser irradiator 18 irradiates the combined film F1 and the workpiece W1 with a laser, and then pressure is applied by the pressure roller 19.

[0031] The welding method in the welding section 20 is not limited to laser welding as exemplified, but can also be various other welding methods. The welding section 20 only needs to be able to weld the workpiece fed from the first roller and the film fed from the second roller in a specific area.

[0032] Furthermore, the shapes of the workpiece W0 and the film F0 only need to be shapes that can be fed out by rollers. The materials of the workpiece W0 and the film F0 only need to be materials that can be welded together. The welding method in the welding section 20 only needs to be an appropriate method corresponding to the materials of the workpiece W0 and the film F0.

[0033] Furthermore, the welding apparatus 1 includes a position detection unit that detects the position of the workpiece and the film, and a snake correction unit that corrects the snake movement of the workpiece W0 and the film F0. The position detection unit detects the position of the element that becomes the snake correction element in the snake correction unit and transmits position information indicating that position to the snake correction unit. Hereinafter, the transmitted position information will also be referred to as position. The snake correction unit corrects the snake movement of the workpiece W0 and the film F0 by changing the inclination of the first roller and the second roller based on the positions of the workpiece and the film input from the position detection unit. The position detection unit and the snake correction unit will be described in detail below.

[0034] The position detection unit detects the positions of one or two ends of workpiece W0 in the width direction and the positions of one or two ends of thin film F0 in the width direction. Furthermore, the position detection unit also detects the positions of one or two ends of workpiece W1 in the width direction. The position detection units are exemplified by the first position detection unit 13, the second position detection unit 14, and the third position detection unit 15, as described below. The first position detection unit 13, the second position detection unit 14, and the third position detection unit 15 can all be constructed from optical sensors or the like.

[0035] The first position detection unit 13 detects the position of the outermost end of the width direction end region SA side of the workpiece W0. Therefore, the first position detection unit 13 is configured and arranged as follows: by measuring... Figure 1 The area shown in the diagram as detection area 13A is used to detect the edge SEa on the side of the width-direction end region SA of the workpiece W0. Since the width of the workpiece W0 is known during manufacturing, the first position detection unit 13 can be configured to detect the other edge SEb of the workpiece W0. In any case, the first position detection unit 13 can be configured to detect both edges SEa and SEb of the workpiece W0. Furthermore, for convenience, in... Figure 1 In the diagram, edges SEa and SEb are both represented by the extensions of the actual workpiece W0's edges.

[0036] The second position detection unit 14 detects the position of the outermost end of the width-direction end region SA side of the workpiece W1 after the workpiece W0 has undergone serpentine correction. Therefore, the second position detection unit 14 is configured as follows: by measuring... Figure 1 The area shown in the diagram as detection area 14A is used to detect the edge SEa on the side of the width-direction end region SA of the workpiece W1. Since the width of the workpiece W1 is known during manufacturing, the second position detection unit 14 can be configured to detect the other edge SEb of the workpiece W1. In any case, the second position detection unit 14 can be configured to detect both edges SEa and SEb of the workpiece W1. The positions of the workpiece before and after the serpentine correction can be detected at different positions in this way, but the workpiece W0 before correction can also be detected at a position where the position of the corrected workpiece W1 can be detected.

[0037] The third position detection unit 15 detects the position of one or both ends of the film F0 in the width direction. Therefore, the third position detection unit 15 is configured and arranged as follows: by measuring... Figure 1The detection area 15A shown in the diagram is used to detect the edges of one or both sides of the film F0. Furthermore, the third position detection unit 15 detects the position of the ends of one or both sides of the film F1 in the width direction after the snake-like correction has been performed to verify the snake-like correction. The positions of the film before and after the snake-like correction can be detected at the same position or at different positions. Since the width of the film F0 is known during manufacturing, when detecting the edge of one end of the film F0, the supply position of the film F1 relative to the workpiece W1 can be determined regardless of which side's edge is being detected, as described later.

[0038] The serpentine correction section corrects the serpentine behavior of workpiece W0 and film F1 at the flow correction point, i.e., before roller 12e. The serpentine-corrected workpiece W1 and the serpentine-corrected film F1 then merge through roller 12e.

[0039] The serpentine correction unit may include, for example, a first correction control unit 16 and a main conveyor serpentine correction mechanism that is controlled thereunder, and a second correction control unit 17 and a sub-conveyor serpentine correction mechanism that is controlled thereunder. In any case, the first correction control unit 16 and the second correction control unit 17 can be mounted on the welding device 1 as a single correction control unit.

[0040] The first correction control unit 16 performs control as follows: it corrects the serpentine movement of the workpiece W0 conveyed in the main conveyor line based on the position detected by the first position detection unit 13. The first correction control unit 16 may also be referred to as the first main conveyor line serpentine correction control unit. The main conveyor line serpentine correction mechanism, which is the object of this control, can be configured to change the inclination of the roller 11 included in the conveying mechanism that conveys the workpiece W0. The inclination of the roller 11 can be set to... Figure 1 The difference in height between the two ends of the rotating shaft of the roller 11. That is, the main conveyor line serpentine correction mechanism can be configured to change the height of one or both end faces of the roller 11. Through the correction of the first correction control unit 16, the workpiece W1 is conveyed in a centered state in the width direction in the main conveyor line.

[0041] The second correction control unit 17 performs the following control: it corrects the serpentine movement of the film F0 conveyed in the sub-conveyor 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 referred to as the second sub-conveyor line serpentine correction control unit.

[0042] The sub-conveyor line serpentine correction mechanism, which is the control object of the second correction control unit 17, can be configured to change the inclination of any one or more of the rollers 12b, 12c, and 12d included in the conveying mechanism of the conveying film F0. Taking roller 12b as an example, the inclination of roller 12b can be set to... Figure 1The difference in height between the two ends of the rotating shaft of the roller 12b. That is, the sub-conveyor line serpentine correction mechanism can be configured to change the height of one or both end faces of the roller 12b.

[0043] To explain in more detail, the second correction control unit 17 determines the supply position of the film F1 relative to the workpiece W1 based on the edge position of the workpiece W1 after correcting its serpentine state. The determined supply position is the position of the film F1 relative to the workpiece W1 in the width direction, and is set as 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.

[0044] Next, the second correction control unit 17 corrects the serpentine movement of the film F0 by changing the inclination of the second rollers, exemplified by rollers 12b, 12c, and 12d, 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 the determined supply position. With this correction, the film F1 can be supplied to the workpiece W1 at the aforementioned supply position.

[0045] Alternatively, the second correction control unit 17 may first calculate the supply position of the film F1 relative to the workpiece W1 based on the edge position of the workpiece W0 before the serpentine correction, and then correct the supply position based on the edge position of the workpiece W1 after the serpentine correction. In this case, the second correction control unit 17 can correct the serpentine movement of the film F0 by changing the inclination of the second roller based on the edge position of the film F0 detected by the third position detection unit 15, so that it is consistent with the corrected supply position.

[0046] After performing this serpentine correction, the welding section 20 performs welding. That is, the welding section 20 overlaps the workpiece W1, which is the serpentine corrected workpiece W0, with the film F1, which is the serpentine corrected film F0, and performs welding in a specific area such as the end region SA in one width direction of the workpiece W1.

[0047] use Figure 2 An example of the state of the welding process performed by the welding device will be explained. Figure 2 This is a schematic cross-sectional view showing an example of the state of the welding process.

[0048] The workpiece W1 and the film F1, positioned by the above positioning method, are overlapped on the roller 12e, which becomes the confluence point, and the laser beam LA is irradiated on a specific area from the side of the film F1 by the laser irradiator 18 while the pressure roller 19 performs the welding.

[0049] Specifically, firstly, as illustrated in state 21, if a laser beam LA is irradiated from the thin film F1 side, the laser beam LA is transmitted through the thin film F1, which is the transmitting material, and absorbed by the workpiece W1, which is the absorber. Through this absorption, as illustrated in state 22, the irradiated area of ​​the workpiece W1 by the laser beam LA heats up, becoming the heated area HE. Thus, the laser irradiator 18 irradiates the thin film F1, which is a supply from the sub-conveyor line, with a laser beam of a wavelength that is transmitted but does not allow heat to enter, thereby allowing heat to enter the absorber and only reaching the interface to be welded.

[0050] Then, as illustrated in state 23, if the film F1 and the workpiece W1 are conveyed to the position of the pressure roller 19, pressure is applied from the film F1 toward the workpiece W1 by the pressure roller 19, and heat conduction occurs in the direction indicated by the upward arrow, with heat being conducted to the film F1. As a result, as illustrated in state 24, the heating area HE also reaches the side of the film F1, and the film F1 melts. Finally, as illustrated in state 25, through the pressing of the pressure roller 19 and the passage of time, the heating area HE is cooled and pressed into a welding area SE, thereby welding the film F1 and the workpiece W1 together.

[0051] Next, use Figure 3 An example of a welding method including the positioning method described in this embodiment will be explained. Figure 3 This is a flowchart illustrating an example of the welding method.

[0052] First, the first position detection unit 13 detects the position of workpiece W0 (step S1). Next, the first correction control unit 16 corrects the serpentine movement of workpiece W0 by changing the inclination of the first roller (exemplified by roller 11) according to the position of workpiece W0 (step S2). Next, the second position detection unit 14 detects the position of workpiece W1, which is the workpiece W0 after serpentine correction (step S3).

[0053] The second correction control unit 17 determines the supply position of the film F1 relative to the workpiece W1 based on the position of the workpiece W1 after correcting its serpentine state (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 (e.g., roller 12b) to correct the serpentine movement of the film F0 so that it matches the determined supply position (step S6). Correcting the serpentine movement of the film F0 means moving the supply position to the determined supply position.

[0054] Then, roller 12e merges the serpentine-corrected workpiece W1 with the serpentine-corrected film F1, and welding section 20 welds the serpentine-corrected workpiece W1 and the serpentine-corrected film F1 (step S7), and the process ends.

[0055] Furthermore, in this embodiment, when the workpiece and film are merged and welded only in a specific area, in order to continuously transport the strip-shaped workpiece and film, the position detection of the edge of the workpiece in the width direction and the edge of the film in the width direction can be continuously performed while the welding process continues. Then, in this embodiment, the workpiece's serpentine movement is first corrected using the workpiece's position, and then the serpentine-corrected workpiece position and the film's position are used to correct the film's serpentine movement and merge it. Therefore, according to this embodiment, high-precision positioning can be achieved when welding the workpiece and film in a specific area.

[0056] To illustrate the above-mentioned and further effects based on this embodiment, the following methods are used: Figure 4 and Figure 5 The welding method involved in the comparative example will be explained. Figure 4 This is a schematic perspective view showing the method of handling the workpiece involved in the comparative example. Figure 5 This is a schematic cross-sectional view showing the state of the heat input process involved in the comparative example.

[0057] In the welding methods involved in the comparative examples, such as Figure 4 As shown, a robot 40 grips and transports a rectangular, single-piece workpiece W4, using cameras 45 and 46 for position correction, and a contact-type hot soldering iron to weld thin films F4a and F4b onto each edge. The robot 40 comprises: a main body 41 including a control unit; an arm base 42 disposed on the main body 41; an arm 43 disposed on the arm base 42; and a gripping unit 44 that grips the workpiece W4 by adsorption. In this welding process, as... Figure 5 As shown, a thin film F4a or F4b and a workpiece W4 are sandwiched between the upper part 51u and the lower part 51d of a hot soldering iron equipped with a heating section 52. Heat is introduced from the side of the thin film F4a or F4b by the heating section 52, and welding is performed. Alternatively, heat can be introduced from the side of the workpiece W4.

[0058] In the welding method described in the comparative example, if the workpiece W4 is a large and thin rectangular workpiece, it takes time to achieve adsorption by air when gripped by the robot 40. In contrast, in this embodiment, since the processing is performed on a belt conveyor, there is no need to pick up the workpiece.

[0059] Furthermore, in the welding method described in the comparative example, since heat is applied from the outside of the film using a hot soldering iron, time is required for heat transfer to the welding surface, thus welding takes time. Also, in the welding method described in the comparative example, if the film is removed from the hot soldering iron while heated, it will weld to the iron, requiring cooling and solidification; from the viewpoint that this cooling time is necessary, welding also takes time. In contrast, in this embodiment, heat is applied and cooled instantaneously by laser, therefore welding takes no time, allowing for continuous processing on a conveyor belt. Furthermore, in this embodiment, since heat can only be applied to the welding interface, the film does not weld to the pressure roller, enabling high-speed workpiece delivery.

[0060] Furthermore, in the welding method described in the comparative example, since the position is corrected based on a representative point, the positional accuracy across the entire area is not high. More specifically, in the welding method described in the comparative example, the positions of the two ends of one side are detected, and the long side is aligned. Therefore, the positional accuracy outside the two ends is directly affected by the product's tolerances, which become deviation factors, and the positional accuracy across the entire area cannot be considered high. In contrast, in this embodiment, the edge position of the main conveyor line is continuously detected across the entire area, and further, the edge position of the sub-conveyor line is continuously detected, thereby enabling high-precision film supply and processing across the entire area.

[0061] As described above, this embodiment continuously conveys a strip-shaped workpiece in the main conveyor line and simultaneously merges the film from the sub-conveyor line with high precision, performing continuous welding processing. Furthermore, in this embodiment, the position of the main conveyor line is detected in advance, and the supply position of the sub-conveyor line is also determined. The merging position is then controlled to supply the film, and a laser is used to heat and weld it in a short time. Therefore, compared to the comparative example, this embodiment achieves high-precision position control, enables continuous processing, and allows for high-speed film welding.

[0062] Furthermore, the positioning or welding methods described above can be used to manufacture electrode sheets for lithium-ion batteries. In this case, the manufactured electrode sheet is configured to include a thin film exemplified by thin film F1 and a workpiece exemplified by workpiece W1. Although examples of the thin film and workpiece included in the electrode sheet are omitted, their shape or material is sufficient as long as they can function as electrode sheets and can be welded together.

[0063] Furthermore, the present invention is not limited to the embodiments described above, and appropriate modifications can be made without departing from the spirit of the invention. For example, the positioning or welding methods described above can be applied in various fields besides the manufacture of electrode sheets for lithium-ion batteries.

[0064] Symbol Explanation

[0065] 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 end area, SEa, SEb-Edge, W0, W1-Workpiece.

Claims

1. A positioning method, characterized in that, A welding apparatus equipped with a first roller for feeding a workpiece and a second roller for feeding a film, and which welds the workpiece and the film in a specific area, performs the following processing: The serpentine movement of the workpiece is corrected by changing the inclination of the first roller according to the position of the workpiece. Then, based on the position of the workpiece after correcting its serpentine state, the supply position of the film relative to the workpiece is determined; Then, the tilt of the second roller is changed according to the position of the film to correct the serpentine motion of the film.

2. The positioning method according to claim 1, characterized in that, The positioning method is used to manufacture electrode sheets for lithium-ion batteries.

3. A welding method, characterized in that, The welding device overlaps the workpiece and the film, which are positioned by the positioning method of claim 1 or 2, and performs welding while irradiating the specific area from the side of the film with a laser beam.

4. A welding device, characterized in that, have: The first roller that feeds out the workpiece; The second roller that delivers the film; A welding section that welds the workpiece and the film together in a specific area; A position detection unit that detects the position of the workpiece and the position of the film; and The serpentine correction unit corrects the serpentine movement of the workpiece by changing the inclination of the first roller according to the position of the workpiece. Then, based on the position of the workpiece after the serpentine movement has been corrected, it determines the supply position of the film relative to the workpiece. Then, based on the position of the film, it corrects the serpentine movement of the film by changing the inclination of the second roller.

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