Method of joining sheets

Abstract

The present invention provides a method for joining sheets that ensures joint strength without heating the joint between the preceding sheet and the succeeding sheet when replacing the raw material roll. [Solution] The sheet joining method according to the present disclosure is a sheet joining method for continuously supplying sheets by joining the end of a preceding sheet to the end of a succeeding sheet, comprising the steps of: overlapping the preceding sheet and the succeeding sheet and clamping them with a pair of clamps; cutting the preceding sheet and the succeeding sheet clamped by the pair of clamps along the width direction; winding up the rear side of the cut preceding sheet in the supply direction and winding up the front side of the cut succeeding sheet in the supply direction; and joining the unwinded end of the preceding sheet and the end of the succeeding sheet with tape, wherein in the joining step, tape is applied from both sides in the thickness direction to the ends of the preceding sheet and the succeeding sheet that face each other along the supply direction.

Description

Technical Field

[0001] The present disclosure relates to a method for joining sheets.

Background Art

[0002] There is a sheet supply device that feeds out a sheet from a roll in which a sheet of a predetermined length is wound, that is, a raw roll, and supplies it to the next process. In the sheet supply device, when the sheet of the raw roll being supplied runs out, it is necessary to supply the sheet from another raw roll. If the supply of the sheet is stopped when replacing the raw roll, the working efficiency decreases. Therefore, it is required to join the sheet to another raw roll while continuing the supply of the sheet. For example, Patent Document 1 discloses a method of automatically joining the end of a preceding sheet and the end of a succeeding sheet to each other with a tape in a production line.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regarding the method of joining the end of the preceding sheet and the end of the succeeding sheet disclosed in Patent Document 1 with a tape, the inventors have found the following problems. In Patent Document 1, the end of the preceding sheet and the end of the succeeding sheet that are abutted against each other are joined with a tape, and the joining strength is improved by heating the joined portion. However, in the case of a sheet that cannot be heated, the joining strength cannot be ensured.

[0005] The present disclosure has been made to solve such problems, and provides a sheet joining method capable of ensuring the joining strength without heating the joined portion between the preceding sheet and the succeeding sheet when replacing the raw roll. [Means for solving the problem]

[0006] The sheet joining method according to this disclosure is a sheet joining method for joining the end of a preceding sheet and the end of a succeeding sheet to supply sheets continuously, comprising the steps of: overlapping the preceding sheet and the succeeding sheet and clamping them with a pair of clamps; cutting the preceding sheet and the succeeding sheet clamped by the pair of clamps along the width direction; winding up the rear side of the cut preceding sheet in the supply direction and winding up the front side of the cut succeeding sheet in the supply direction; and joining the unwinded end of the preceding sheet and the end of the succeeding sheet with tape, wherein in the joining step, the tape is applied from both sides in the thickness direction to the ends of the preceding sheet and the succeeding sheet that face each other along the supply direction.

[0007] In the clamping process, if the widthwise displacement of the trailing sheet relative to the preceding sheet exceeds a predetermined value, the displacement may be corrected by moving at least one of the raw material rolls of the preceding sheet and the trailing sheet in the widthwise direction.

[0008] In the clamping step, after clamping the preceding sheet and the succeeding sheet with the pair of clamps, each of the pair of clamps sucks the preceding sheet and the succeeding sheet with a plurality of suction sections provided along the supply direction; in the cutting step, the preceding sheet and the succeeding sheet, which are clamped and overlapping with the pair of clamps, are cut along the width direction between the plurality of suction sections; and in the winding step, the suction of the suction section in contact with the rear side of the cut preceding sheet in the supply direction is stopped, and the suction of the suction section in contact with the front side of the cut succeeding sheet in the supply direction is stopped before winding.

[0009] In the joining process, the ends of the preceding sheet and the succeeding sheet may be held together from one side in the thickness direction by an end-holding mechanism and then faced towards each other along the supply direction, after which the tape may be applied from the other side in the thickness direction, and after the end-holding mechanism is separated from the preceding sheet and the succeeding sheet, the tape may be applied from one side in the thickness direction.

[0010] In the joint where the ends of the preceding sheet and the succeeding sheet are joined together by the tape, the gap between the ends of the preceding sheet and the succeeding sheet may be 0.5 mm or less, and the widthwise displacement between the ends of the preceding sheet and the succeeding sheet may be 1.0 mm or less. [Effects of the Invention]

[0011] The present invention provides a method for joining sheets that ensures joint strength without heating the joint between the preceding sheet and the succeeding sheet when replacing the raw material roll. [Brief explanation of the drawing]

[0012] [Figure 1] This is a side view of the sheet supply device according to Embodiment 1. [Figure 2] This figure shows a joint in which the ends of a preceding sheet and a succeeding sheet are joined together with tape, according to Embodiment 1. [Figure 3] This is an explanatory diagram of the first sensor and the second sensor according to Embodiment 1. [Figure 4] This figure shows a sheet supply device in the clamping process according to Embodiment 1. [Figure 5] This figure shows a sheet supply device in the cutting process according to Embodiment 1. [Figure 6] This figure shows a sheet supply device in the winding process according to Embodiment 1. [Figure 7] This figure shows a sheet supply device in the joining process according to Embodiment 1. [Figure 8]This figure shows a sheet supply device in the joining process according to Embodiment 1. [Figure 9] This figure shows a sheet supply device in the joining process according to Embodiment 1. [Modes for carrying out the invention]

[0013] The following describes specific embodiments of this disclosure in detail with reference to the drawings. However, this disclosure is not limited to the following embodiments. Also, for clarity, the following descriptions and drawings have been simplified as appropriate.

[0014] (Embodiment 1) <Configuration of the sheet supply device> First, with reference to Figures 1 to 3, the configuration of the sheet supply device used in the sheet supply method according to this embodiment 1 will be described. Figure 1 is a side view of the sheet supply device according to embodiment 1. Figure 2 is a diagram showing the joint portion in which the ends of the preceding sheet and the following sheet are joined together with tape, according to embodiment 1. Figure 3 is an explanatory diagram of the first sensor and the second sensor according to embodiment 1.

[0015] The sheet supply device 1 shown in Figure 1 is a device that continuously supplies sheets S to the next process. The sheet supply device 1 supplies sheets from the first raw material roll Ra. When the sheets on the first raw material roll Ra run out or are expected to run out, the sheet supply device 1 supplies sheets from the second raw material roll Rb, which is pre-installed in the sheet supply device 1. Here, while continuing to supply sheets S, the sheet supply device 1 changes the raw material roll supplying sheets S from the first raw material roll Ra to the second raw material roll Rb. More specifically, the sheet supply device 1 joins the end of the sheet supplied from the first raw material roll Ra (hereinafter referred to as the preceding sheet Sa) and the end of the sheet supplied from the second raw material roll Rb (hereinafter referred to as the succeeding sheet Sb), and continuously supplies sheets S.

[0016] Before explaining the configuration of the sheet feeding device 1, referring to FIG. 2, a portion (hereinafter, joint portion) where the end of the preceding sheet Sa and the end of the succeeding sheet Sb are joined by a tape T will be described. The upper diagram in FIG. 2 is a cross-sectional view of the joint portion where the end of the preceding sheet Sa and the end of the succeeding sheet Sb are joined. The lower diagram in FIG. 2 is a top view of the joint portion where the end of the preceding sheet Sa and the end of the succeeding sheet Sb are joined.

[0017] The joint portion is required to have a joint strength such that the joint is not released even when tension is applied. For example, in the case of a method of joining the preceding sheet Sa to one side of a tape having adhesiveness on both sides and joining the succeeding sheet Sb to the opposite side of the tape, the joint portion can ensure sufficient joint strength. However, in the joint portion, since the preceding sheet Sa, the succeeding sheet Sb, and the tape are laminated, the thickness of the joint portion increases. Therefore, there is a risk of causing sheet jamming in the apparatus of the next process.

[0018] Therefore, the sheet joining method according to the first embodiment is to attach the tape T from both sides in the thickness direction (x-axis direction) to the preceding sheet Sa and the succeeding sheet Sb whose ends face each other along the supply direction (z-axis direction) as shown in the upper diagram of FIG. 2. Thereby, the thickness of the joint portion is suppressed. Further, since the tape T is attached from both sides in the thickness direction (x-axis direction) of the joint portion, sufficient joint strength can be ensured without heating the joint portion.

[0019] Therefore, the sheet joining method according to the first embodiment can also be adopted for a sheet joining method using a slot paper as the sheet S, which is used for fixing a segment coil inserted into a stator. The tape T is not particularly limited in material as long as it has adhesiveness on one side, and examples thereof include paper tape, resin tape, cloth tape, and the like. The surface of the tape T having adhesiveness contacts the preceding sheet Sa and the succeeding sheet Sb.

[0020] Furthermore, as shown in the lower diagram of Figure 2, by keeping the gap G in the direction of travel (z-axis direction) between the ends of the leading sheet Sa and the trailing sheet Sb, and the displacement D in the width direction (y-axis direction) between the ends of the leading sheet Sa and the trailing sheet Sb below predetermined values, the joint strength can be further ensured. For example, it is preferable that the gap G is 0.5 mm or less and the displacement D is 1.0 mm or less.

[0021] Returning to Figure 1, the configuration of the sheet supply device 1 will be explained. As shown in Figure 1, the sheet supply device 1 comprises a case 10, a first sensor 20, a second sensor 30, a guide 40, a clamp 50, a cutting blade 60, a winding mechanism 70, an end holding mechanism 80, and a tape application mechanism 90.

[0022] In the following explanation, we will use the xyz 3D Cartesian coordinate system as appropriate. In this embodiment 1, the width direction of the sheet S is the y-axis direction. In the following explanation, the z-axis direction is the vertical direction, and the xy-plane is the horizontal plane. Of course, the z-axis direction may be inclined from the vertical direction, and the xy-plane may also be a plane inclined from the horizontal plane.

[0023] Case 10 is a housing in which the raw material rolls are stored. The case 10 shown in Figure 1 includes a first case 10a and a second case 10b. The first raw material roll Ra is stored in the first case 10a. The second raw material roll Rb is stored in the second case 10b. Both the first raw material roll Ra and the second raw material roll Rb are installed so that their axes are in the y-axis direction. Near the point where the first case 10a and the second case 10b are adjacent, the ends of the leading sheet Sa and the trailing sheet Sb are joined together. Therefore, as shown in Figure 1, near the point where the first case 10a and the second case 10b are adjacent, the leading sheet Sa and the trailing sheet Sb are arranged facing each other along the thickness direction (x-axis direction).

[0024] Each of the first case 10a and the second case 10b includes a linear motion mechanism 12, which is composed of, for example, a ball screw or a servo motor, and an LM guide 13. The linear motion mechanism 12 and the LM guide 13 extend in the width direction (y-axis direction) of the sheet S and are positioned at the bottom of each of the first case 10a and the second case 10b. The linear motion mechanism 12 and the LM guide 13 allow the first case 10a and the second case 10b to move independently along the width direction (y-axis direction) of the sheet S. By moving at least one of the first case 10a and the second case 10b along the width direction (y-axis direction), the sheet supply device 1 can correct the widthwise misalignment of the trailing sheet Sb relative to the preceding sheet Sa. This corrects the widthwise misalignment D between the ends of the preceding sheet Sa and the trailing sheet Sb shown in the lower diagram of Figure 2.

[0025] The first sensor 20 and the second sensor 30 are used to correct the widthwise (y-axis direction) displacement D between the edges of the leading sheet Sa and the trailing sheet Sb, as shown in the lower diagram of Figure 2. The first sensor 20 and the second sensor 30 are, for example, image sensors, laser displacement sensors, or photoelectric sensors. Below, we will give an example in which the first sensor 20 is a laser displacement sensor and the second sensor 30 is an image sensor.

[0026] The first sensor 20 and the second sensor 30 will be described with reference to Figure 3. The left side of Figure 3 shows the positional relationship between the preceding sheet Sa and the first sensor 20. The right side of Figure 3 shows the positional relationship between the following sheet Sb and the second sensor 30.

[0027] As shown in the left diagram of Figure 3, the first sensor 20 comprises a light-emitting unit 21 that emits laser light LA ​​and a light-receiving unit 22 that receives the laser light LA. The pair of light-emitting units 21 and light-receiving units 22 are installed such that a portion of the band-shaped laser light LA ​​extending from the light-emitting unit 21 to the light-receiving unit 22 is blocked by the preceding sheet Sa. Two pairs of light-emitting units 21 and light-receiving units 22 are provided along the width direction (y-axis direction) of the preceding sheet Sa. The first sensor 20 acquires the relative distances D_a1 and D_a2 of the edges of the preceding sheet Sa with respect to a reference position RL in the width direction (y-axis direction).

[0028] As shown in the right-hand diagram of Figure 3, the second sensor 30 is installed such that a portion of the imaging area IA is obscured by the trailing sheet Sb. Two second sensors 30 are provided along the width direction (y-axis direction) of the trailing sheet Sb. The second sensors 30 acquire the relative distances D_b1 and D_b2 of the edges of the trailing sheet Sb with respect to the reference block 31 in the width direction (y-axis direction).

[0029] Based on the relative distances D_a1 and D_a2 of the edges of the preceding sheet Sa with respect to the reference position RL, and the relative distances D_b1 and D_b2 of the edges of the following sheet Sb with respect to the reference block 31, the sheet supply device 1 calculates the widthwise (y-axis direction) displacement D of the following sheet Sb relative to the preceding sheet Sa. The sheet supply device 1 then corrects the widthwise displacement D of the following sheet Sb relative to the preceding sheet Sa by moving at least one of the first case 10a and the second case 10b along the widthwise (y-axis direction). As a result, the widthwise (y-axis direction) displacement D between the ends of sheet Sa and the following sheet Sb is corrected, as shown in the lower diagram of Figure 2.

[0030] Returning to the explanation of Figure 1, multiple guides 40 are provided in the first case 10a and the second case 10b, respectively, to change the transport direction of the preceding sheet Sa and the following sheet Sb. For example, pulleys or pins can be used as guides 40.

[0031] One of the pair of clamps 50 is provided on the first case 10a, and the other of the pair of clamps 50 is provided on the second case 10b. The pair of clamps 50 are positioned near the location where the first case 10a and the second case 10b are adjacent, so as to clamp the leading sheet Sa and the trailing sheet Sb in the thickness direction (x-axis direction). When the raw material roll supplying the sheets S is changed from the first raw material roll Ra to the second raw material roll Rb, the pair of clamps 50 move toward each other (x-axis direction). The pair of clamps 50 then overlap the leading sheet Sa and the trailing sheet Sb and clamp the overlapped leading sheet Sa and trailing sheet Sb.

[0032] Each of the pair of clamps 50 is provided with a plurality of suction parts 51 arranged along the supply direction (z-axis direction). After the pair of clamps 50 grips the leading sheet Sa and the trailing sheet Sb, the leading sheet Sa and the trailing sheet Sb are each sucked by the suction parts 51. In this way, the pair of clamps 50 fixes each of the leading sheet Sa and the trailing sheet Sb to the contact surface with the pair of clamps 50. Note that the method of fixing each of the leading sheet Sa and the trailing sheet Sb to the contact surface with the pair of clamps 50 is not limited to the method using the suction parts 51. The pair of clamps 50 may, for example, have an adhesive sheet on the contact surface between the leading sheet Sa and the trailing sheet Sb, and the leading sheet Sa and the trailing sheet Sb may be fixed to the contact surface with the pair of clamps 50 by the adhesive sheet.

[0033] One of the pair of cutting blades 60 shown in Figure 1 is provided in the first case 10a, and the other of the pair of cutting blades 60 is provided in the second case 10b. Note that the cutting blades 60 do not have to be a pair; they may be provided in only one of the first case 10a or the second case 10b. The pair of cutting blades 60 cut the leading sheet Sa and the trailing sheet Sb, which are held by a pair of clamps 50, along the width direction (y-axis direction) near the position where the first case 10a and the second case 10b are adjacent.

[0034] At least one winding mechanism 70 is provided in the second case 10b. The winding mechanism 70 is mounted in the case 10 so as to be rotatable with the width direction (y-axis direction) of the sheet S as its axis of rotation. Before the raw material roll supplying the sheet S is replaced from the first raw material roll Ra to the second raw material roll Rb, the trailing sheet Sb supplied from the second raw material roll Rb is connected to the winding mechanism 70 in the second case 10b. After the leading sheet Sa and the trailing sheet Sb are cut by the pair of cutting blades 60, the winding mechanism 70 winds up the forward side (positive z-axis direction) of the cut trailing sheet Sb in the supply direction.

[0035] The end-holding mechanism 80 is provided in at least one of the first case 10a and the second case 10b. The end-holding mechanism 80 holds the ends of the leading sheet Sa and the trailing sheet Sb facing each other. The operation of the end-holding mechanism 80 will be described in detail later.

[0036] One of the pair of tape application mechanisms 90 is provided in the first case 10a, and the other of the pair of tape application mechanisms 90 is provided in the second case 10b. The pair of tape application mechanisms 90 are positioned near the location where the first case 10a and the second case 10b are adjacent, sandwiching the leading sheet Sa and the trailing sheet Sb in the thickness direction (x-axis direction). The pair of tape application mechanisms 90 are provided with tape T on the surfaces facing the leading sheet Sa and the trailing sheet Sb.

[0037] After the cutting blade 60 cuts the leading sheet Sa and the trailing sheet Sb, the pair of tape application mechanisms 90 move toward each other (in the x-axis direction). Then, as shown in the upper diagram of Figure 2, the pair of tape application mechanisms 90 apply tape T to the leading sheet Sa and the trailing sheet Sb, whose ends face each other along the supply direction (z-axis direction), from both sides in the thickness direction (x-axis direction).

[0038] <How to replace the seat> Next, a method for replacing a sheet using the sheet supply device 1 will be described. The sheet replacement method according to this embodiment 1 comprises a clamping step (step S101), a cutting step (step S102), a winding step (step S103), and a joining step (step S104).

[0039] The operation of the sheet supply device 1 in sheet replacement will be explained below in the order of each process, referring to Figures 4 to 9. Figure 4 is a diagram of the sheet supply device in the clamping process according to Embodiment 1. Figure 5 is a diagram of the sheet supply device in the cutting process according to Embodiment 1. Figure 6 is a diagram of the sheet supply device in the winding process according to Embodiment 1. Figures 7 to 9 are diagrams of the sheet supply device in the joining process according to Embodiment 1. The upper diagrams in Figures 4 to 9 are side views of the sheet supply device 1. The lower diagrams in Figures 4 to 9 are cross-sectional views near the joining section.

[0040] Clamping process (Step S101) First, the pair of clamps 50a and 50b overlap and clamp the leading sheet Sa and the trailing sheet Sb, as shown in Figure 4 (step S101). After the pair of clamps 50a and 50b clamp the leading sheet Sa and the trailing sheet Sb, the suction parts 51a and 51b suck the leading sheet Sa and the trailing sheet Sb, respectively.

[0041] Before the pair of clamps 50a and 50b overlap and clamp the leading sheet Sa and the trailing sheet Sb, the sheet supply device 1 corrects the widthwise displacement D of the trailing sheet Sb relative to the leading sheet Sa. The first sensor 20 and the second sensor 30 calculate the widthwise displacement D of the trailing sheet Sb relative to the leading sheet Sa (in the y-axis direction). If the displacement D is greater than or equal to a predetermined value, the sheet supply device 1 moves at least one of the first case 10a and the second case 10b along the widthwise direction (in the y-axis direction). In this way, the sheet supply device 1 corrects the widthwise displacement D of the trailing sheet Sb relative to the leading sheet Sa. After correcting the displacement D, the pair of clamps 50a and 50b overlap and clamp the leading sheet Sa and the trailing sheet Sb.

[0042] Cutting process (Step S102) Next, as shown in Figure 5, the pair of cutting blades 60 cut the leading sheet Sa and the trailing sheet Sb, which are held in place and overlapped by the pair of clamps 50a and 50b (step S102). More specifically, the pair of cutting blades 60 cut the leading sheet Sa and the trailing sheet Sb along the width direction (y-axis direction) between the multiple suction parts 51a (or between the multiple suction parts 51b). As a result, as shown in the lower part of Figure 5, the cutting line CL formed by the pair of cutting blades 60 is formed between the multiple suction parts 51a (or between the multiple suction parts 51b) on the leading sheet Sa and the trailing sheet Sb.

[0043] Winding process (Step S103) Next, as shown in Figure 6, the first raw material roll Ra winds up the rear side (negative z-axis direction) of the cut preceding sheet Sa in the supply direction, while the winding mechanism 70 winds up the front side (positive z-axis direction) of the cut succeeding sheet Sb in the supply direction (positive z-axis direction) (step S103). More specifically, as shown in the lower part of Figure 6, the first raw material roll Ra winds up the preceding sheet Sa on the rear side (negative z-axis direction) of the supply direction relative to the cutting line CL, while the winding mechanism 70 winds up the succeeding sheet Sb on the front side (positive z-axis direction) of the supply direction relative to the cutting line CL. The preceding sheet Sa on the rear side (negative z-axis direction) of the supply direction relative to the cutting line CL and the succeeding sheet Sb on the front side (positive z-axis direction) of the supply direction relative to the cutting line CL, which were not wound up, are joined in the next joining step (step S104).

[0044] In the winding process (step S103), clamp 50a stops suction from the suction section 51a that contacts the preceding sheet Sa on the rear side (negative z-axis side) in the supply direction relative to the cutting line CL. Then, the first raw material roll Ra starts winding. Also, clamp 50b stops suction from the suction section 51b that contacts the following sheet Sb on the front side (positive z-axis side) in the supply direction relative to the cutting line CL. Then, the winding mechanism 70 starts winding.

[0045] By selectively stopping the suction of the multiple suction units 51 in this manner, the sheet supply device 1 can wind up the leading sheet Sa and trailing sheet Sb that are not needed for the joining process (step S104) while maintaining the fixed positions of the leading sheet Sa and trailing sheet Sb that are needed for the joining process (step S104). This prevents the leading sheet Sa and trailing sheet Sb that are needed from shifting positions when winding up the unnecessary leading sheet Sa and trailing sheet Sb. Therefore, it is possible to suppress the expansion of the gap G in the direction of travel (z-axis direction) between the ends of the leading sheet Sa and trailing sheet Sb.

[0046] Joining process (Step S104) Finally, as shown in Figure 9, the pair of tape application mechanisms 90 join the end of the preceding sheet Sa that was not wound up in the winding process (step S103) with the end of the following sheet Sb using tape T (step S104).

[0047] In the joining process (step S104), first, as shown in Figure 7, the end-holding mechanism 80 holds the ends of the leading sheet Sa and the trailing sheet Sb facing each other. The operation of the end-holding mechanism 80 will now be explained in detail.

[0048] In the winding process (step S103), after the leading sheet Sa and trailing sheet Sb on the side not required for joining are wound up, the end holding mechanism 80 contacts the leading sheet Sa and trailing sheet Sb from one side in the thickness direction (positive x-axis direction side). The end holding mechanism 80 then uses a suction means provided on the end holding mechanism 80 to suck the ends of the leading sheet Sa and the trailing sheet Sb together. As a result, the end holding mechanism 80 aligns the ends of the leading sheet Sa and the trailing sheet Sb with the surface of the end holding mechanism 80.

[0049] Furthermore, to ensure that the edges of the leading sheet Sa and the trailing sheet Sb conform more easily to the surface of the edge holding mechanism 80, gas may be blown towards the edges of the leading sheet Sa and the trailing sheet Sb from the other side in the thickness direction (negative x-axis direction) using an air blower 81, as shown in the lower diagram of Figure 7. In summary, the edges of the leading sheet Sa and the trailing sheet Sb are held facing each other on the surface of the end holding mechanism 80 by the end holding mechanism 80 and the air blower 81.

[0050] Due to being wound on the raw material roll, the leading sheet Sa and the trailing sheet Sb have a curl. Therefore, after cutting, the ends of the leading sheet Sa and the trailing sheet Sb will be warped due to the curl. If joining with tape T is performed while they are still warped, the gap G in the direction of travel (z-axis direction) between the ends of the leading sheet Sa and the trailing sheet Sb may become larger than desired. Therefore, the end holding mechanism 80 corrects the warping of the ends of the leading sheet Sa and the trailing sheet Sb after cutting using the method described above, and holds the ends of the leading sheet Sa and the trailing sheet Sb facing each other.

[0051] The method for holding the ends of the leading sheet Sa and the trailing sheet Sb facing each other on the surface of the end-holding mechanism 80 is not limited to a method using suction means provided on the end-holding mechanism 80. For example, the end-holding mechanism 80 may have an adhesive sheet on its surface, and the ends of the leading sheet Sa and the trailing sheet Sb may be held facing each other on the surface of the end-holding mechanism 80 by the adhesive sheet.

[0052] Next, as shown in Figure 8, the end-holding mechanism 80 holds the ends of the preceding sheet Sa and the following sheet Sb facing each other, while the tape application mechanism 90a applies the tape T from the other side in the thickness direction (negative x-axis direction). Then, after the end holding mechanism 80 separates from the preceding sheet Sa and the following sheet Sb, the tape application mechanism 90b applies the tape T from one side in the thickness direction (the positive x-axis direction side), as shown in Figure 9.

[0053] As described above, the sheet connection method according to this embodiment 1 involves applying tape T from both sides in the thickness direction (x-axis direction) to a leading sheet Sa and a trailing sheet Sb whose ends face each other along the supply direction (z-axis direction). This reduces the thickness of the joint between the leading sheet Sa and the trailing sheet Sb. Furthermore, the sheet connection method according to this embodiment 1 ensures that the gap G in the direction of travel (z-axis direction) between the ends of the leading sheet Sa and the trailing sheet Sb, and the displacement D in the width direction (y-axis direction) between the ends of the leading sheet Sa and the trailing sheet Sb are kept below a predetermined value. This ensures that the joint strength between the leading sheet Sa and the trailing sheet Sb can be secured without heating the joint.

[0054] 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. [Explanation of Symbols]

[0055] 1. Sheet feeding device 10 cases 10a Case 1 10b Case 2 12 Linear motion mechanism 13 LM Guide 20 First Sensor 21 Light-emitting part 22 Light receiving part 30. Second sensor 31 Reference Blocks 40 Guide 50, 50a, 50b clamps 51, 51a, 51b Suction part 60 cutting blade 70 Winding mechanism 80 End retention mechanism 81 Air blow 90, 90a, 90b Tape application mechanism CL cutting line D deviation D_a1, D_a2, D_b1, D_b2 relative distance G Gap IA imaging area LA laser light Ra 1st Roll Rb 2nd Roll of Raw Material RL reference position S Seat Sa Priority Seat Sb Rear seat T Tape

Claims

1. A method for joining sheets, which involves joining the end of a preceding sheet to the end of a following sheet to supply sheets continuously, The process involves overlapping the preceding sheet and the succeeding sheet and clamping them together with a pair of clamps, A step of cutting the preceding sheet and the succeeding sheet, which are held by the pair of clamps, along the width direction, A step of winding up the rear side of the cut preceding sheet in the supply direction, and winding up the front side of the cut succeeding sheet in the supply direction, The process includes joining the end of the preceding sheet that was not wound up with the end of the following sheet using tape, In the joining process, the tape is applied to the ends of the preceding sheet and the succeeding sheet, which face each other along the supply direction, from both sides in the thickness direction. Method of joining sheets.

2. In the clamping process, if the widthwise displacement of the trailing sheet relative to the preceding sheet exceeds a predetermined value, the displacement is corrected by moving at least one of the raw material rolls of the preceding sheet and the trailing sheet in the widthwise direction. The method for joining sheets according to claim 1.

3. In the clamping process, after the pair of clamps clamp the preceding sheet and the succeeding sheet, each of the pair of clamps then sucks the preceding sheet and the succeeding sheet, respectively, with a plurality of suction sections provided along the supply direction. In the cutting process, the preceding sheet and the succeeding sheet, which are held together and overlapping by the pair of clamps, are cut along the width direction between the plurality of suction sections. In the winding process, the suction of the suction unit in contact with the rear side in the supply direction of the cut preceding sheet is stopped, and the suction of the suction unit in contact with the front side in the supply direction of the cut succeeding sheet is stopped, and then winding is performed. A method for joining sheets according to claim 1 or 2.

4. In the joining process, After the ends of the preceding sheet and the succeeding sheet are held together from one side in the thickness direction by the end-holding mechanism and facing each other along the supply direction, the tape is applied from the other side in the thickness direction. Furthermore, after separating the end-holding mechanism from the preceding sheet and the succeeding sheet, the tape is attached from one side in the thickness direction. A method for joining sheets according to claim 1 or 2.

5. In the joint where the ends of the preceding sheet and the succeeding sheet are joined together by the tape, The gap between the ends of the preceding sheet and the following sheet is 0.5 mm or less. The widthwise displacement between the edges of the preceding sheet and the succeeding sheet is 1.0 mm or less. A method for joining sheets according to claim 1 or 2.

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