Dross conveyor, laser machining device, and workpiece machining method

Abstract

This dross conveyor is equipped with a group of conveyor plates that convey dross produced by laser irradiation of a workpiece, said group including a first conveyor plate extending in a first direction and a second conveyor plate disposed adjacent to the first conveyor plate and extending in the first direction. The first conveyor plate comprises: a first front end part; a first back end part; and a first intermediate portion connecting the first front end part and the first back end part, the first intermediate portion having a first recessed part extending in the first direction.

Description

Dross transport conveyor, laser processing device, and workpiece processing method

[0001] The present invention relates to a dross transport conveyor, a laser processing device, and a workpiece processing method.

[0002] A laser processing machine equipped with a chip conveyor is known.

[0003] As a related technique, Patent Document 1 discloses a chip conveyor for a laser processing machine. The chip conveyor described in Patent Document 1 has multiple plates that form a conveyor belt. Each plate is connected to the other plates by a joint so that they can be bent freely.

[0004] Microfilm of Utility Model Application No. 3-19091 (Utility Model Application No. 4-108984)

[0005] An object of the present invention is to provide a dross transport conveyor, a laser processing device, and a workpiece processing method that can suppress thermal deformation of the transport plate.

[0006] In some embodiments, the dross transport conveyor includes a group of transport plates including a first transport plate extending in a first direction and a second transport plate disposed adjacent to the first transport plate and extending in the first direction, the first transport plate having a first front end, a first rear end, and a first intermediate portion having a first recess extending in the first direction and connecting the first front end and the first rear end.

[0007] In some embodiments, the laser processing apparatus includes a laser irradiation device including a laser head that irradiates a laser beam toward a workpiece, a moving device that moves the laser head relative to a workpiece support member that supports the workpiece, a control device that controls the laser irradiation device and the moving device, and a dross transport conveyor. The dross transport conveyor includes a group of transport plates that includes a first transport plate extending in a first direction and a second transport plate disposed adjacent to the first transport plate and extending in the first direction, and transports dross generated by irradiating the workpiece with the laser. The first transport plate has a first front end, a first rear end, and a first intermediate portion that has a first recess extending in the first direction and connects the first front end and the first rear end.

[0008] In some embodiments, a workpiece machining method includes the steps of machining the workpiece by irradiating the workpiece with a laser, and transporting dross generated by the laser irradiation of the workpiece using a group of transport plates including a first transport plate extending in a first direction and a second transport plate disposed adjacent to the first transport plate and extending in the first direction. The first transport plate includes a first front end, a first rear end, and a first intermediate portion having a first recess extending in the first direction and connecting the first front end and the first rear end. The step of machining the workpiece is performed in a state where thermal deflection of the first transport plate is suppressed by the direction in which the first intermediate portion thermally deflects when the first recess is irradiated with the laser being opposite to the direction in which the first front end is thermally deflected when the first front end is irradiated with the laser.

[0009] The present invention provides a dross transport conveyor, a laser processing device, and a workpiece processing method that can suppress thermal deformation of the transport plate.

[0010] FIG. 1 is a schematic cross-sectional view showing a laser processing apparatus according to a first embodiment. FIG. 2 is a schematic cross-sectional view showing a portion of the laser processing apparatus according to the first embodiment. FIG. 3 is a schematic cross-sectional view showing an example of a first transport plate. FIG. 4 is a schematic perspective view showing an example of a first transport plate. FIG. 5 is a schematic perspective view showing a transport plate according to a comparative example. FIG. 6 is a schematic perspective view showing a first recessed portion thermally deflecting in a fourth direction due to laser irradiation of the first recessed portion. FIG. 7 is a schematic perspective view showing a first front end portion thermally deflecting in a third direction due to laser irradiation of the first front end portion. FIG. 8 is a schematic perspective view showing the laser processing apparatus according to the first embodiment. FIG. 9 is a schematic perspective view showing a group of transport plates including a first transport plate and a second transport plate that can move along a circular orbit. FIG. 10 is a schematic perspective view showing a dross transport conveyor according to the first embodiment. FIG. 11 is an exploded perspective view schematically showing a portion of a group of transport plates. FIG. 12 is a diagram schematically showing a state in which a first transport plate is attached to a first endless chain and a second endless chain. FIG. 13 is a schematic cross-sectional view showing an enlarged view of a turning portion of the dross transport conveyor in the first embodiment. FIG. 14 is a schematic cross-sectional view schematically showing a portion of the laser processing apparatus in the first embodiment. FIG. 15 is a schematic perspective view schematically showing an example of the first transport plate and the second transport plate. FIG. 16 is a schematic cross-sectional view schematically showing a portion of the laser processing apparatus in the first embodiment. FIG. 17 is a schematic cross-sectional view schematically showing a portion of the laser processing apparatus in the first embodiment. FIG. 18 is a schematic perspective view schematically showing an example of the first transport plate and the second transport plate. FIG. 19 is a schematic cross-sectional view schematically showing a portion of the laser processing apparatus in the first embodiment. FIG. 20 is a schematic perspective view schematically showing an example of the first transport plate and the second transport plate. Fig. 21 is a schematic cross-sectional view showing a part of the laser processing apparatus in the first embodiment. Fig. 22 is a schematic cross-sectional view showing a part of the laser processing apparatus in the first embodiment.FIG. 23 is a schematic perspective view showing an example of a first transport plate and a second transport plate. FIG. 24 is a schematic plan view showing an example of a first transport plate. FIG. 25 is a schematic cross-sectional view showing a portion of a group of transport plates. FIG. 26 is a schematic cross-sectional view showing a state in which the orbit of a group of transport plates includes an upward slope. FIG. 27 is a schematic side view showing a laser processing apparatus according to the first embodiment. FIG. 28 is a schematic plan view showing a portion of a laser processing apparatus according to the first embodiment. FIG. 29 is a schematic perspective view showing an example of a workpiece support member. FIG. 30 is a schematic perspective view showing a laser processing apparatus according to a first modified example of the first embodiment. FIG. 31 is a schematic plan view showing a state in which a machined workpiece is removed from a workpiece support member. FIG. 32 is a schematic perspective view showing a laser processing apparatus according to a second modified example of the first embodiment. FIG. 33 is a diagram showing a state in which a control device can control multiple control target devices. FIG. 34 is a schematic side view showing a laser processing apparatus according to the first embodiment. FIG. 35 is a schematic cross-sectional view showing a portion of a laser processing apparatus including a cooling device. FIG. 36 is a schematic cross-sectional view showing a portion of a laser processing apparatus according to a second embodiment. FIG. 37 is a schematic cross-sectional view showing a portion of a laser processing apparatus according to the second embodiment. FIG. 38 is an exploded perspective view showing a portion of a group of transport plates. FIG. 39 is a schematic perspective view showing a state in which a group of transport plates including a first transport plate and a second transport plate are movable along an orbit. FIG. 40 is a schematic cross-sectional view showing a portion of a laser processing apparatus according to the second embodiment. FIG. 41 is an exploded perspective view showing a portion of a group of transport plates. FIG. 42 is a schematic cross-sectional view showing a portion of a group of transport plates. FIG. 43 is a flowchart showing an example of a workpiece processing method according to the third embodiment.

[0011] Hereinafter, the dross transport conveyor 2, the laser processing device 1, and the workpiece processing method according to the embodiment will be described with reference to the drawings. In the following description of the embodiment, parts and members having the same functions are given the same reference numerals, and repeated descriptions of parts and members given the same reference numerals will be omitted.

[0012] (Definition of Terms) As illustrated in FIG. 2 , each of the group of transport plates 3 has a transport surface 3u. In this specification, the term "transport surface" refers to a surface that supports dross directly or indirectly via other members during dross transport. More specifically, the transport surface 3u is a surface that faces generally upward during dross transport. For example, the first transport surface 3u-1 of the first transport plate 3-1 supports dross directly or indirectly via other members during dross transport by the first transport plate 3-1. The first transport surface 3u-1 of the first transport plate 3-1 faces generally upward during dross transport by the first transport plate 3-1. Furthermore, the second transport surface 3u-2 of the second transport plate 3-2 supports dross directly or indirectly via other members during dross transport by the second transport plate 3-2. The second transport surface 3u-2 of the second transport plate 3-2 faces generally upward when the second transport plate 3-2 transports dross.

[0013] As illustrated in FIG. 2 , each of the group of transport plates 3 has a back surface 3n. In this specification, the back surface refers to the surface of each transport plate opposite the transport surface 3u. More specifically, the back surface 3n is a surface that faces generally downward when transporting dross. For example, the first back surface 3n-1 of the first transport plate 3-1 is a surface that is located below the first transport surface 3u-1 when transporting dross by the first transport plate 3-1. The first back surface 3n-1 of the first transport plate 3-1 faces generally downward when transporting dross by the first transport plate 3-1. Furthermore, the second back surface 3n-2 of the second transport plate 3-2 is a surface that is located below the second transport surface 3u-2 when transporting dross by the second transport plate 3-2. More specifically, the second back surface 3n-2 of the second transport plate 3-2 faces generally downward when transporting dross by the second transport plate 3-2.

[0014] In this specification, the area that can be reached by the laser emitted from the laser irradiation device 60 is defined as a "processing area RG1" (see FIG. 1). The workpiece W placed in the processing area RG1 is processed by the laser (more specifically, cut or drilled). Dross generated by irradiating the workpiece W with the laser is received by a group of transport plates 3 in the processing area RG1.

[0015] (Definition of Directions) In this specification, the extension direction of the first transport plate 3-1 (or the extension direction of each transport plate 3) is defined as the first direction DR1. In this specification, the movement direction of the first group of transport plates 3 (or the movement direction of each transport plate 3) is defined as the second direction DR2. As illustrated in FIG. 9, in this specification, the direction from the inside of the orbit OB of the first group of transport plates 3 (see the area hatched with dots in FIG. 9) to the outside of the orbit OB is defined as the third direction DR3, and the direction opposite to the third direction DR3 is defined as the fourth direction DR4. As illustrated in FIG. 2, the third direction DR3 is the direction from the first back surface 3n-1 of the first transport plate 3-1 to the first transport surface 3u-1 of the first transport plate 3-1. The third direction DR3 is the direction from the second back surface 3n-2 of the second transport plate 3-2 toward the second transport surface 3u-2 of the second transport plate 3-2. As illustrated in Figure 2, the fourth direction DR4 is the direction from the first transport surface 3u-1 of the first transport plate 3-1 toward the first back surface 3n-1 of the first transport plate 3-1. The fourth direction DR4 is the direction from the second transport surface 3u-2 of the second transport plate 3-2 toward the second back surface 3n-2 of the second transport plate 3-2.

[0016] First Embodiment A dross transport conveyor 2A and a laser processing apparatus 1A according to a first embodiment will be described with reference to FIGS. 1 to 35. FIG. 1 is a schematic cross-sectional view of the laser processing apparatus 1A according to the first embodiment. FIG. 2 is a schematic cross-sectional view of a portion of the laser processing apparatus 1A according to the first embodiment. FIG. 3 is a schematic cross-sectional view of an example of a first transport plate 3-1. FIG. 4 is a schematic perspective view of an example of a first transport plate 3-1. FIG. 5 is a schematic perspective view of a transport plate 3' according to a comparative example. FIG. 6 is a schematic perspective view of the first recess Q1 thermally deflecting in the fourth direction DR4 due to irradiation of the first recess Q1 with a laser beam LB. FIG. 7 is a schematic perspective view of the first front end 3f-1 thermally deflecting in the third direction DR3 due to irradiation of the first front end 3f-1 with a laser beam LB. FIG. 8 is a schematic perspective view showing a laser processing apparatus 1A according to the first embodiment. FIG. 9 is a schematic perspective view showing a group of transport plates 3 including a first transport plate 3-1 and a second transport plate 3-2 moving along a circular orbit OB. FIG. 10 is a schematic perspective view showing a dross transport conveyor 2A according to the first embodiment. FIG. 11 is an exploded perspective view showing a portion of a group of transport plates 3. FIG. 12 is a diagram showing a first transport plate 3-1 attached to a first endless chain 21a and a second endless chain 22a. FIG. 13 is a schematic cross-sectional view showing an enlarged view of a turning portion of the dross transport conveyor 2A according to the first embodiment. FIG. 14 is a schematic cross-sectional view showing a portion of a laser processing apparatus 1A according to the first embodiment. FIG. 15 is a schematic perspective view showing an example of a first transport plate 3-1 and a second transport plate 3-2. Figures 16 and 17 are schematic cross-sectional views showing a portion of the laser processing apparatus 1A in the first embodiment. Figure 18 is a schematic perspective view showing an example of the first transport plate 3-1 and the second transport plate 3-2. Figure 19 is a schematic cross-sectional view showing a portion of the laser processing apparatus 1A in the first embodiment. Figure 20 is a schematic perspective view showing an example of the first transport plate 3-1 and the second transport plate 3-2.21 and 22 are schematic cross-sectional views showing a portion of the laser processing apparatus 1A according to the first embodiment. FIG. 23 is a schematic perspective view showing an example of the first transport plate 3-1 and the second transport plate 3-2. FIG. 24 is a schematic plan view showing an example of the first transport plate 3-1. FIG. 25 is a schematic cross-sectional view showing a portion of the first group of transport plates 3. FIG. 26 is a schematic cross-sectional view showing a state in which the orbit OB of the first group of transport plates 3 includes an ascending slope CL. FIG. 27 is a schematic side view showing a portion of the laser processing apparatus 1A according to the first embodiment. FIG. 28 is a schematic plan view showing a portion of the laser processing apparatus 1A according to the first embodiment. FIG. 29 is a schematic perspective view showing an example of a workpiece support member 90. FIG. 30 is a schematic perspective view showing a laser processing apparatus 1A according to a first modified example of the first embodiment. Fig. 31 is a schematic plan view showing a state in which a machined workpiece Wb is removed from a work support member 90. Fig. 32 is a schematic perspective view showing a laser processing apparatus 1A in a second modified example of the first embodiment. Fig. 33 is a diagram showing a state in which a control device 8 can control a plurality of control target devices. Fig. 34 is a schematic side view showing a laser processing apparatus 1A in the first embodiment. Fig. 35 is a schematic cross-sectional view showing a part of a laser processing apparatus including a cooling device 95.

[0017] As illustrated in FIG. 2, the dross transport conveyor 2A in the first embodiment includes a group of transport plates 3.

[0018] The first group of transport plates 3 transports dross D generated by irradiating the workpiece W with the laser LB. In addition to the dross D, the first group of transport plates 3 may also transport cut-off pieces CF generated by irradiating the workpiece W with the laser LB.

[0019] In this specification, dross refers to an irregularly shaped mass (in other words, a randomly shaped mass) formed by solidification of a material (more specifically, a metal material) melted by laser irradiation.

[0020] The group of transport plates 3 includes a first transport plate 3-1 extending in the first direction DR1 and a second transport plate 3-2 extending in the first direction DR1. Each of the group of transport plates 3 is an elongated plate with the first direction DR1 as its longitudinal direction. In the example shown in FIG. 2, the second transport plate 3-2 is disposed adjacent to the first transport plate 3-1.

[0021] The first transport plate 3-1 has a front end (hereinafter referred to as the "first front end 3f-1"), a rear end (hereinafter referred to as the "first rear end 3e-1"), and an intermediate portion (hereinafter referred to as the "first intermediate portion 3m-1"). In the example shown in Figure 2, the first front end 3f-1 is the end on the front side in the movement direction (in other words, the end on the second direction DR2 side), and the first rear end 3e-1 is the end on the rear side in the movement direction (in other words, the end on the opposite side from the second direction DR2).

[0022] The first intermediate portion 3m-1 connects the first front end portion 3f-1 and the first rear end portion 3e-1. In Fig. 3, the first intermediate portion 3m-1 is hatched with dots to make it easier to understand.

[0023] As illustrated in Fig. 3, the first intermediate portion 3m-1 has a first recess Q1. As illustrated in Fig. 4, the first recess Q1 extends in a first direction DR1.

[0024] 2, the laser beam LB passes through the workpiece W and reaches the dross transport conveyor 2A. Part of the energy of the laser beam LB is converted into thermal energy, which raises the temperature of the first transport plate 3-1. This temperature rise causes the first transport plate 3-1 to thermally deform and bend in the third direction DR3 or the fourth direction DR4.

[0025] In the comparative example, the first intermediate portion 3m-1 of the transport plate 3' (see FIG. 5) is entirely flat. In this case, thermal deformation of the transport plate 3' due to temperature rise is greater than when the first intermediate portion 3m-1 has the first recess Q1. In particular, excessive thermal deformation of the transport plate 3' may occur under the following conditions: (1) the output of the laser LB is high (or the energy density of the laser LB is high); (2) the length of the transport plate 3' in the direction along the first direction DR1 is long; (3) the area of ​​the first intermediate portion 3m-1 (in other words, the area of ​​the flat portion) is large; and (4) the distance between the workpiece and the dross transport conveyor is short. Furthermore, excessive thermal deformation of the transport plate 3' may hinder smooth movement of a group of transport plates, including the transport plate 3'.

[0026] In the dross conveyor 2A according to the first embodiment, the first recess Q1 prevents the first conveying plate 3-1 from excessively bending in the third direction DR3 or the fourth direction DR4 due to laser irradiation, thereby enabling smooth movement of the group of conveying plates 3 including the first conveying plate 3-1.

[0027] 1 , the laser processing apparatus 1A in the first embodiment includes the above-mentioned dross transport conveyor 2A, a laser irradiation device 60 including a laser head 61 that irradiates a laser LB toward a workpiece W, a moving device 7 that moves the laser head 61 relative to a workpiece support member 90 that supports the workpiece W, and a control device 8 that controls the laser irradiation device 60 and the moving device 7. Note that one computer may function as the control device 8, or multiple computers may function in cooperation as the control device 8.

[0028] The laser processing device 1A in the first embodiment has the same effects as the dross transport conveyor 2A in the first embodiment.

[0029] (Optional additional configuration) Next, referring to Figures 1 to 35, optional additional configurations that can be adopted in the dross transport conveyor 2A and laser processing apparatus 1A in the first embodiment (or the dross transport conveyor 2B and laser processing apparatus 1B in the second embodiment described below) will be described.

[0030] (First recess Q1) In the example shown in FIG. 3, the first recess Q1 is a recess recessed in the fourth direction DR4. In other words, the first recess Q1 is a recess recessed in a direction from the first transport surface 3u-1 of the first transport plate 3-1 toward the first back surface 3n-1 of the first transport plate 3-1. In the example shown in FIG. 3, the first recess Q1 is located closer to the fourth direction DR4 than the first front end 3f-1. Furthermore, the first recess Q1 is located closer to the fourth direction DR4 than the first rear end 3e-1. The first recess Q1 has a transport surface that transports the dross and a back surface that is located on the opposite side of the transport surface.

[0031] The conveying surface of the first recess Q1 is a concave conveying surface SD1 that is concave in the fourth direction DR4. In the example shown in Figure 3, the concave conveying surface SD1 has a generally arc shape in a cross section perpendicular to the first direction DR1. Alternatively, the concave conveying surface SD1 may have a generally V-shape, a generally U-shape, or another shape in a cross section perpendicular to the first direction DR1.

[0032] The back surface of the first recess Q1 is a protruding surface SN1 that protrudes in the fourth direction DR4. In the example shown in Fig. 3, the protruding surface SN1 has a generally arcuate shape in a cross section perpendicular to the first direction DR1. Alternatively, the protruding surface SN1 may have a generally V-shape, a generally U-shape, or another shape in a cross section perpendicular to the first direction DR1.

[0033] 6, when the laser beam LB is irradiated onto the first recess Q1 of the first transport plate 3-1, the first intermediate portion 3m-1 (or the first transport plate 3-1) thermally deflects in the fourth direction DR4. Note that in FIG. 6, the amount of deflection of the first transport plate 3-1 is exaggerated compared to the actual amount of deflection.

[0034] 7, when the first front end 3f-1 of the first transport plate 3-1 is irradiated with the laser LB, the first front end 3f-1 (or the first transport plate 3-1) is thermally deflected in the third direction DR3. Note that in FIG. 7, the amount of deflection of the first transport plate 3-1 is exaggerated compared to the actual amount of deflection.

[0035] In the example shown in Figures 6 and 7, the direction in which the first front end 3f-1 of the first transport plate 3-1 is thermally deflected by irradiating the first front end 3f-1 with the laser beam LB is opposite to the direction in which the first intermediate portion 3m-1 is thermally deflected by irradiating the first recess Q1 with the laser beam LB. Therefore, when the first transport plate 3-1 moves in the second direction DR2 across the laser beam LB, at least a portion of the deflection caused by the laser beam irradiating the first front end 3f-1 is canceled out by the deflection caused by the laser beam irradiating the first intermediate portion 3m-1. This reduces the amount of deflection of the first transport plate 3-1 as a whole, suppressing changes in the relative positions of the first rear end 3e-1 of the first transport plate 3-1 and the second front end 3f-2 of the second transport plate 3-2. As a result, the group of transport plates 3 including the first transport plate 3-1 can be moved smoothly.

[0036] 1, a portion of the dross transport conveyor 2A is disposed directly below the laser irradiation device 60. Furthermore, one group of transport plates 3 of the dross transport conveyor 2A is configured to be movable across the processing region RG1 (more specifically, the region directly below the laser irradiation device 60).

[0037] In the example shown in Fig. 1, the first group of transport plates 3 transports dross from the processing region RG1 to the discharge region RG2. In the example shown in Fig. 1, each of the first group of transport plates 3 is reversed in the discharge region RG2 (more specifically, turned 180 degrees around the horizontal axis). As a result, the dross D transported by the first group of transport plates 3 is discharged from the first group of transport plates 3 to the container 13 in the discharge region RG2. Note that when the first group of transport plates 3 transports cut-off pieces CF (see Fig. 2), the cut-off pieces CF are also discharged from the first group of transport plates 3 to the container 13 in the discharge region RG2.

[0038] 8 , the dross transport conveyor 2A includes a first endless member 21, a second endless member 22, and a drive device 29. The first endless member 21 and the second endless member 22 support a group of transport plates 3. More specifically, the group of transport plates 3 is attached to the first endless member 21 and the second endless member 22.

[0039] The first endless member 21 and the second endless member 22 are driven directly or indirectly by a driving device 29. More specifically, the first endless member 21 is driven directly or indirectly by the driving device 29 to move along a first orbital orbit B1 (see FIG. 9 ), and the second endless member 22 is driven directly or indirectly by the driving device 29 to move along a second orbital orbit B2 (see FIG. 9 ) parallel to the first orbital orbit B1. A gap G1 between the first orbital orbit B1 and the second orbital orbit B2 (in other words, the distance between the first orbital orbit B1 and the second orbital orbit B2 in the direction along the first direction DR1) is, for example, not less than 1 m and not more than 3 m.

[0040] 10, the first endless member 21 is a first endless chain 21a, and the second endless member 22 is a second endless chain 22a. In the example shown in Fig. 10, the dross transport conveyor 2 has a plurality of sprockets 28 including a first sprocket 28a, a second sprocket 28b, a third sprocket 28c, and a fourth sprocket 28d. The first endless chain 21a is engaged with at least the first sprocket 28a and the second sprocket 28b (more specifically, the first endless chain 21a is looped around at least the first sprocket 28a and the second sprocket 28b). The second endless chain 22a is engaged with at least the third sprocket 28c and the fourth sprocket 28d (more specifically, the second endless chain 22a is looped around at least the third sprocket 28c and the fourth sprocket 28d).

[0041] In the example shown in Figure 10, the first endless chain 21a is driven by a drive device 29 via at least a first sprocket 28a, and the second endless chain 22a is driven by a drive device 29 via at least a third sprocket 28c.

[0042] The group of transport plates 3 moves along an orbital path OB. As illustrated in Fig. 9, the orbital path OB of the group of transport plates 3 is parallel to the first orbital path B1 of the first endless chain 21a and parallel to the second orbital path B2 of the second endless chain 22a.

[0043] (First group of transport plates 3) As illustrated in Fig. 2, each of the first group of transport plates 3 transports a portion of the multiple pieces of dross D generated by irradiating the workpiece W with the laser LB, and is heated by the laser LB. For example, each of the first transport plate 3-1 and the second transport plate 3-2 transports a portion of the multiple pieces of dross D generated by irradiating the workpiece W with the laser LB, and is heated by the laser LB. Each of the first group of transport plates 3 may be composed of a single part, or may be composed of an assembly of multiple parts.

[0044] In the example shown in FIG. 2 , the dross transport conveyor 2A has a group of transport plates 3 including a first transport plate 3-1, a second transport plate 3-2, and a third transport plate 3-3. Each of the group of transport plates 3 extends along a first direction DR1. The number of transport plates 3 included in one group of transport plates 3 is, for example, 20 or more, 50 or more, or 80 or more. In this specification, the number of transport plates 3 included in one group of transport plates 3 is defined as "N." "N" is, for example, a natural number greater than or equal to 20.

[0045] When "K" is defined as any natural number between 1 and "N-1," the K+1th transport plate is arranged adjacent to the Kth transport plate. Also, the first transport plate 3-1 is arranged adjacent to the Nth transport plate. In this way, the group of transport plates 3 is arranged in a ring shape as a whole. For example, the second transport plate 3-2 is arranged adjacent to the first transport plate 3-1 and also adjacent to the third transport plate 3-3.

[0046] Each of the group of transport plates 3 has a front end 3 f, a rear end 3 e, and an intermediate portion 3 m connecting the front end 3 f and the rear end 3 e. In the example shown in Fig. 2, the front end 3 f of each transport plate 3 is the end on the front side in the movement direction (in other words, the end on the side of the second direction DR2), and the rear end 3 e of each transport plate 3 is the end on the rear side in the movement direction (in other words, the end on the opposite side from the second direction DR2).

[0047] In the example shown in Figure 2, the front end 3f of each transport plate 3 is arranged so as to overlap with the rear end 3e of another adjacent transport plate 3 when viewed in a plan view (in other words, when viewed in a direction along the fourth direction DR4), and the rear end 3e of each transport plate 3 is arranged so as to overlap with the front end 3f of another adjacent transport plate when viewed in a plan view (in other words, when viewed in a direction along the fourth direction DR4).

[0048] For example, the first front end 3f-1 of the first transport plate 3-1 is arranged to overlap the rear end 3e-N of the other transport plate 3-N in a plan view (in other words, when viewed in the direction along the fourth direction DR4). More specifically, the rear end 3e-N of the other transport plate 3-N is covered by the first front end 3f-1 of the first transport plate 3-1.

[0049] For example, the first rear end 3e-1 of the first transport plate 3-1 is arranged to overlap the second front end 3f-2 of the second transport plate 3-2 in a plan view (in other words, when viewed in the direction along the fourth direction DR4). More specifically, the first rear end 3e-1 of the first transport plate 3-1 is covered by the second front end 3f-2 of the second transport plate 3-2.

[0050] For example, the second rear end 3e-2 of the second transport plate 3-2 is arranged to overlap the third front end 3f-3 of the third transport plate 3-3 in a plan view (in other words, when viewed in the direction along the fourth direction DR4). More specifically, the second rear end 3e-2 of the second transport plate 3-2 is covered by the third front end 3f-3 of the third transport plate 3-3.

[0051] 11 , each of the group of transport plates 3 has a left end 3 a and a right end 3 b. In the example shown in Fig. 11 , the left end 3 a of each transport plate 3 is the left end when viewing the transport surface 3 u of the transport plate 3 in the direction from the rear end 3 e to the front end 3 f, and the right end 3 b of each transport plate 3 is the right end when viewing the transport surface 3 u of the transport plate 3 in the direction from the rear end 3 e to the front end 3 f.

[0052] The first transport plate 3-1 has a first front end 3f-1, a first rear end 3e-1, a first intermediate portion 3m-1 connecting the first front end 3f-1 and the first rear end 3e-1, a left end 3a-1, and a right end 3b-1.

[0053] The second transport plate 3-2 has a second front end 3f-2, a second rear end 3e-2, a second intermediate portion 3m-2 connecting the second front end 3f-2 and the second rear end 3e-2, a left end 3a-2, and a right end 3b-2.

[0054] The third transport plate 3-3 has a third front end 3f-3, a third rear end 3e-3, a third intermediate portion 3m-3 connecting the third front end 3f-3 and the third rear end 3e-3, a left end 3a-3, and a right end 3b-3.

[0055] The length of each of the group of transport plates 3 (more specifically, the length in the direction along the first direction DR1) is, for example, 1 m or more and 3 m or less. The length L1 of the first transport plate 3-1 is, for example, 1 m or more and 3 m or less, and the length of the second transport plate 3-2 is, for example, 1 m or more and 3 m or less.

[0056] The width of each of the first group of transport plates 3 (more specifically, the width of each of the first group of transport plates 3 in the direction along the second direction DR2) is, for example, 40 mm or more and 200 mm or less. The width W1 of the first transport plate 3-1 is, for example, 40 mm or more and 200 mm or less, and the width W2 of the second transport plate 3-2 is, for example, 40 mm or more and 200 mm or less.

[0057] The plate thickness of each of the first group of transport plates 3 is, for example, 5 mm or less or 3 mm or less. In the example shown in Figure 3, the plate thickness of the first front end 3f-1 of the first transport plate 3-1 is approximately constant, and the plate thickness of the first rear end 3e-1 of the first transport plate 3-1 is approximately constant. In addition, the plate thickness of the first intermediate portion 3m-1 of the first transport plate 3-1 is approximately constant. In the example shown in Figure 3, the plate thickness of the first transport plate 3-1 as a whole is approximately constant.

[0058] Each of the group of transport plates 3 is made of metal, for example, steel, more specifically, hot-rolled mild steel plate, cold-rolled steel plate, or cold-rolled stainless steel plate.

[0059] The left end 3a of each of the first group of transport plates 3 is attached to a first endless member 21 (more specifically, a first endless chain 21a), and the right end 3b of each of the first group of transport plates 3 is attached to a second endless member 22 (more specifically, a second endless chain 22a).

[0060] In the example shown in FIG. 11, the left end 3a-1 of the first transport plate 3-1 has a hole h1 through which a bolt can be inserted, and the right end 3b-1 of the first transport plate 3-1 has a hole h2 through which a bolt can be inserted. In the example shown in FIG. 12, the left end 3a-1 of the first transport plate 3-1 is attached to the first endless chain 21a via a bolt BT, and the right end 3b-1 of the first transport plate 3-1 is attached to the second endless chain 22a via a bolt BT. As can be seen from FIG. 2, the first transport plate 3-1 is not connected to any adjacent transport plates. Therefore, if the first transport plate 3-1 is damaged, it can be easily replaced with a new first transport plate.

[0061] In the example shown in FIG. 11 , the front end 3 f of each of the first group of transport plates 3 has a convex curved portion CP extending in the first direction DR1. In the example shown in FIG. 11 , the front end 3 f of each of the first group of transport plates 3 has a generally arcuate shape in a cross section perpendicular to the first direction DR1. Alternatively, the front end 3 f of each of the first group of transport plates 3 may have a generally V-shape, a generally U-shape, or some other shape in a cross section perpendicular to the first direction DR1. Note that, because an inverted V-shape becomes a V-shape when viewed from a different direction, the generally inverted V-shape is considered to be included in the generally V-shape in this specification. Similarly, because an inverted U-shape becomes a U-shape when viewed from a different direction, the generally inverted U-shape is considered to be included in the generally U-shape in this specification.

[0062] In the example shown in FIG. 11 , the rear end 3e of each of the first group of transport plates 3 has a standing portion TP protruding in the third direction DR3. As shown in FIG. 13 , the standing portion TP scrapes out dross D below the convexly curved portion CP of the subsequent transport plate when each transport plate 3 turns. For example, the standing portion TP of the first transport plate 3-1 scrapes out dross D below the convexly curved portion CP2 of the second transport plate 3-2 when the first transport plate 3-1 turns. Note that in the first embodiment, the shape of the rear end 3e of each of the first group of transport plates 3 is not limited to the example shown in FIG. 13 . For example, the shape of the rear end 3e of each of the first group of transport plates 3 may be a substantially arc-shaped or substantially circular shape when viewed in the first direction DR1.

[0063] Below, several examples of the transport plate 3 are described, but the transport plate 3 is not limited to the several examples described below. Furthermore, of the multiple transport plates 3, the first transport plate 3-1 and the second transport plate 3-2 are described as representatives, but it goes without saying that a configuration similar to that of the first transport plate 3-1 can be applied to the other transport plates.

[0064] 14 and 15, the first front end 3f-1 of the first transport plate 3-1 has a convex curved portion CP1 that is convex in the third direction DR3 and extends in the first direction DR1. When the first front end 3f-1 has the convex curved portion CP1, the section modulus in the third direction DR3 is increased, and therefore, deflection of the first transport plate 3-1 caused by laser irradiation is suppressed compared to when the entire first front end 3f-1 is flat.

[0065] 14, the first conveying plate 3-1 has a convex curved portion CP1 (more specifically, a convex curved portion CP1 that is convex in the third direction DR3) and a first recess Q1 (more specifically, a concave curved portion QP1 that is concave in the fourth direction DR4). The convex curved portion CP1 has, for example, a substantially arc shape when viewed in the first direction DR1. Furthermore, the concave curved portion QP1 has, for example, a substantially arc shape when viewed in the first direction DR1.

[0066] In the example shown in FIG. 14, the boundary C1 between the convexly curved portion CP1 and the first recess Q1 (more specifically, the concavely curved portion QP1) is the boundary between the first front end portion 3f-1 and the first intermediate portion 3m-1. In the example shown in FIG. 14, the convexly curved portion CP1 and the first recess Q1 (more specifically, the concavely curved portion QP1) are directly connected. Alternatively, as shown in FIG. 16, a first flat portion FP1-1 may be interposed between the convexly curved portion CP1 and the first recess Q1 (more specifically, the concavely curved portion QP1). In the example shown in FIG. 16, the front edge of the first flat portion FP1-1 is connected to the convexly curved portion CP1, and the rear edge of the first flat portion FP1-1 is connected to the first recess Q1 via a bend BC1.

[0067] 14 and 15, the first rear end 3e-1 of the first transport plate 3-1 has a first upright portion TP1 that protrudes in the third direction DR3. The first upright portion TP1 extends in the first direction DR1. When the first rear end 3e-1 has the first upright portion TP1, the section modulus in the third direction DR3 increases, and thus the first upright portion TP1 suppresses deflection of the first transport plate 3-1 caused by laser irradiation. Alternatively, the shape of the first rear end 3e-1 of the first transport plate 3-1 may be a substantially arc-shaped or substantially circular shape when viewed in the first direction DR1.

[0068] 14 and 15, the first intermediate portion 3m-1 of the first transport plate 3-1 and the first rear end portion 3e-1 (more specifically, the first upright portion TP1) of the first transport plate 3-1 are connected via a first bent portion BA1. The first bent portion BA1 extends in the first direction DR1. In the example shown in FIG. 14, the first bent portion BA1 is the boundary between the first intermediate portion 3m-1 and the first rear end portion 3e-1.

[0069] 15, the first front end 3f-1 of the first transport plate 3-1 has a convex transport surface SU1 that is convex in the third direction DR3. The convex transport surface SU1 constitutes a part of the first transport surface 3u-1 of the first transport plate 3-1. The convex transport surface SU1 extends in the first direction DR1.

[0070] In the example shown in Figure 15, the convex conveying surface SU1 has a substantially arc-shaped configuration when viewed in the first direction DR1. Alternatively, the convex conveying surface SU1 may have a substantially V-shaped configuration, a substantially U-shaped configuration, or another shape when viewed in the first direction DR1. Furthermore, the convex conveying surface SU1 has a substantially arc-shaped configuration in a cross section perpendicular to the first direction DR1. Alternatively, the convex conveying surface SU1 may have a substantially V-shaped configuration, a substantially U-shaped configuration, or another shape when viewed in the cross section perpendicular to the first direction DR1.

[0071] As illustrated in Figure 7, when a laser LB is irradiated onto the convex curved portion CP1 (or the convex conveying surface SU1) of the first conveying plate 3-1, the first front end portion 3f-1 (or the first conveying plate 3-1) thermally bends in the third direction DR3.

[0072] 15, the first intermediate portion 3m-1 (more specifically, the first recess Q1) of the first transport plate 3-1 has a concave transport surface SD1 that is concave in the fourth direction DR4. The concave transport surface SD1 constitutes a part of the first transport surface 3u-1 of the first transport plate 3-1. The concave transport surface SD1 extends in the first direction DR1.

[0073] In the example shown in Figure 15, the concave conveying surface SD1 has a generally arcuate shape when viewed in the first direction DR1. Alternatively, the concave conveying surface SD1 may have a generally V-shape, a generally U-shape, or some other shape when viewed in the first direction DR1. Furthermore, the concave conveying surface SD1 has a generally arcuate shape in a cross section perpendicular to the first direction DR1. Alternatively, the concave conveying surface SD1 may have a generally V-shape, a generally U-shape, or some other shape when viewed in the first direction DR1.

[0074] As illustrated in Figure 6, when a laser LB is irradiated onto the first recess Q1 (or the recessed transport surface SD1) of the first transport plate 3-1, the first intermediate portion 3m-1 (or the first transport plate 3-1) thermally bends in the fourth direction DR4.

[0075] The direction in which the first front end 3f-1 thermally bends when the laser LB is irradiated onto the convex curved portion CP1 (or convex conveying surface SU1) of the first conveying plate 3-1 is opposite to the direction in which the first intermediate portion 3m-1 thermally bends when the laser LB is irradiated onto the first recess Q1 (or concave conveying surface SD1). In the first conveying plate 3-1, the thermal deformation of the first front end 3f-1 and the thermal deformation of the first intermediate portion 3m-1 are relatively canceled out, thereby suppressing deformation of the first conveying plate 3-1 as a whole.

[0076] 14, in a plan view (in other words, when viewed in the direction along the fourth direction DR4), the entire first recess Q1 (or the entire recessed transport surface SD1) is disposed between the rear end 3e-N of the other transport plate 3-N arranged adjacent to the first transport plate 3-1 and the first rear end 3e-1 of the first transport plate 3-1. As illustrated in FIG. 14, in a plan view (in other words, when viewed in the direction along the fourth direction DR4), the entire first recess Q1 (or the entire recessed transport surface SD1) may be disposed between the rear end edge E1 of the other transport plate 3-N arranged adjacent to the first transport plate 3-1 and the front leading edge E2 of the second transport plate 3-2.

[0077] In the example shown in FIG. 14, when viewed in the first direction DR1, the first front end portion 3f-1 of the first transport plate 3-1 and the first recess Q1 of the first transport plate 3-1 form a roughly S-shape.

[0078] The direction in which the S-shaped portion thermally bends when a laser beam LB is irradiated onto one part of the S-shaped portion is opposite to the direction in which the S-shaped portion thermally bends when a laser beam LB is irradiated onto another part of the S-shaped portion. The thermal deformation of one part of the S-shaped portion of the first transport plate 3-1 and the thermal deformation of the other part of the S-shaped portion are relatively canceled out, thereby suppressing deformation of the first transport plate 3-1 as a whole.

[0079] 14, the first intermediate portion 3m-1 of the first transport plate 3-1 has a first recess Q1. The first intermediate portion 3m-1 also has a flat portion FP1 separate from the first recess Q1. As illustrated in FIG. 15, the flat portion FP1 extends in the first direction DR1.

[0080] When the first intermediate portion 3m-1 has the first recess Q1 in addition to the flat portion FP1, the area of ​​the flat portion FP1 can be made smaller than when the entire first intermediate portion 3m-1 is flat. Therefore, the thermal deformation caused by the irradiation of the laser LB onto the flat portion FP1 can be made relatively small.

[0081] 14 and 15, the first recess Q1 and the flat plate portion FP1 are connected via a bent portion BB1. The bent portion BB1 extends in the first direction DR1. When the bent portion BB1 is disposed between the first recess Q1 and the flat plate portion FP1, the bent portion BB1 suppresses bending of the first conveying plate 3-1 caused by laser irradiation.

[0082] In the example shown in Fig. 14, the front leading edge E2 of the second transport plate 3-2 is disposed opposite the flat plate portion FP1. In the example shown in Fig. 14, a labyrinth passage is formed that includes the gap between the front leading edge E2 of the second transport plate 3-2 and the flat plate portion FP1 of the first transport plate 3-1, and the gap between the second front end portion 3f-2 of the second transport plate 3-2 and the first rear end portion 3e-1 of the first transport plate 3-1, thereby preventing dross from falling off the first transport plate 3-1 and the second transport plate 3-2.

[0083] In the example shown in FIG. 15, the second front end 3f-2 of the second transport plate 3-2 has a convex curved portion CP2 that is convex in the third direction DR3 and extends in the first direction DR1.

[0084] 15, the second transport plate 3-2 has a second recess Q2 recessed in the fourth direction DR4 in addition to the convex curved portion CP2. More specifically, the second front end 3f-2 of the second transport plate 3-2 has the convex curved portion CP2 that is convex in the third direction DR3 and extends in the first direction DR1, and the second intermediate portion 3m-2 of the second transport plate 3-2 has the second recess Q2 (more specifically, the concave curved portion QP2) that is recessed in the fourth direction DR4 and extends in the first direction DR1.

[0085] In the example shown in FIG. 15, the second rear end 3e-2 of the second transport plate 3-2 has a second standing portion TP2 that protrudes in the third direction DR3 and extends in the first direction DR1.

[0086] In the example shown in Figure 15, the second intermediate portion 3m-2 of the second transport plate 3-2 and the second rear end portion 3e-2 of the second transport plate 3-2 are connected via a second bend BA2 extending in the first direction DR1.

[0087] 15, the second front end 3f-2 of the second transport plate 3-2 has a convex transport surface SU2 that is convex in the third direction DR3 and extends in the first direction DR1. The convex transport surface SU2 constitutes a part of the second transport surface 3u-2 of the second transport plate 3-2.

[0088] 15, the second intermediate portion 3m-2 (more specifically, the second recess Q2) of the second transport plate 3-2 has a recessed transport surface SD2 that is recessed in the fourth direction DR4 and extends in the first direction DR1. The recessed transport surface SD2 constitutes a part of the second transport surface 3u-2 of the second transport plate 3-2.

[0089] As illustrated in Figure 14, when viewed in a plan view (in other words, when viewed in a direction along the fourth direction DR4), the entire second recess Q2 (or the entire recessed conveying surface SD2) may be positioned between the rear edge E3 of the first conveying plate 3-1 and the front tip edge E4 of the third conveying plate 3-3.

[0090] In the example shown in FIG. 14, when viewed in the first direction DR1, the second front end 3f-2 of the second transport plate 3-2 and the second recess Q2 of the second transport plate 3-2 form a substantially S-shape.

[0091] In the example shown in Fig. 14, the second intermediate portion 3m-2 of the second transport plate 3-2 has a flat portion FP2 separate from the second recess Q2. The flat portion FP2 extends in the first direction DR1. In the example shown in Fig. 15, the second recess Q2 and the flat portion FP2 are connected via a bent portion BB2 extending in the first direction DR1.

[0092] 17 and 18, the shape of the recess in the middle portion of each of the first group of transport plates 3 is different from the example shown in FIGS. 14 and 15. In the second example of the transport plate 3, the shapes of the front end and rear end of each of the first group of transport plates 3 are similar to the shapes of the front end and rear end of each of the first group of transport plates 3 in the first example of the transport plate 3. Therefore, repeated explanations of the shapes of the front end and rear end of each of the first group of transport plates 3 will be omitted.

[0093] 17, the first intermediate portion 3m-1 of the first transport plate 3-1 has a first recess Q1. The first recess Q1 is recessed in the fourth direction DR4 and extends in the first direction DR1.

[0094] In the example shown in Fig. 14, the first recess Q1 has a substantially arc shape in a cross section perpendicular to the first direction DR1. In contrast, in the example shown in Fig. 17, the first recess Q1 has a substantially V-shape in a cross section perpendicular to the first direction DR1. Furthermore, the first recess Q1 has a substantially V-shape when viewed in a direction along the first direction DR1.

[0095] In the example shown in Figure 18, the first intermediate portion 3m-1 (more specifically, the first recess Q1) of the first transport plate 3-1 has a concave transport surface SD1 that is concave in the fourth direction DR4. The concave transport surface SD1 extends in the first direction DR1. The concave transport surface SD1 constitutes a part of the first transport surface 3u-1 of the first transport plate 3-1. In the example shown in Figure 18, the concave transport surface SD1 has a substantially V-arc shape when viewed in the direction along the first direction DR1. Furthermore, the concave transport surface SD1 has a substantially V-shape in a cross section perpendicular to the first direction DR1.

[0096] 18, the first intermediate portion 3m-1 of the first transport plate 3-1 has a flat portion FP1 separate from the first recess Q1. The flat portion FP1 extends in the first direction DR1. The first intermediate portion 3m-1 may have a first flat portion FP1-1 and a second flat portion FP1-2.

[0097] 18, the flat portion FP1 (more specifically, the first flat portion FP1-1) and the front edge of the first recess Q1 are connected via a bent portion BC1. Also, in the example shown in FIG. 18, the rear edge of the first recess Q1 and the flat portion FP1 (more specifically, the second flat portion FP1-2) are connected via a bent portion BB1.

[0098] 18, the second front end 3f-2 of the second transport plate 3-2 has a convex curved portion CP2 (more specifically, a convex curved portion CP2 that is convex in the third direction DR3). The second intermediate portion 3m-2 of the second transport plate 3-2 has a second recess Q2. The second recess Q2 is recessed in the fourth direction DR4 and extends in the first direction DR1.

[0099] The shape of the second recess Q2 is the same as the shape of the first recess Q1, so a repeated description of the shape of the second recess Q2 will be omitted.

[0100] 19 and 20, the shape of the recess in the middle portion of each of the first group of transport plates 3 is different from the example shown in FIGS. 14 and 15. In the third example of the transport plate 3, the shapes of the front end and rear end of each of the first group of transport plates 3 are similar to the shapes of the front end and rear end of each of the first group of transport plates 3 in the first example of the transport plate 3. Therefore, repeated explanations of the shapes of the front end and rear end of each of the first group of transport plates 3 will be omitted.

[0101] 19, the first intermediate portion 3m-1 of the first transport plate 3-1 has a first recess Q1. The first recess Q1 is recessed in the fourth direction DR4 and extends in the first direction DR1.

[0102] 19, the first recess Q1 has a substantially U-shape in a cross section perpendicular to the first direction DR1. Also, the first recess Q1 has a substantially U-shape when viewed in a direction along the first direction DR1.

[0103] In the example shown in Figure 20, the first intermediate portion 3m-1 (more specifically, the first recess Q1) of the first transport plate 3-1 has a concave transport surface SD1 that is concave in the fourth direction DR4. The concave transport surface SD1 extends in the first direction DR1. The concave transport surface SD1 constitutes a part of the first transport surface 3u-1 of the first transport plate 3-1. In the example shown in Figure 20, the concave transport surface SD1 has a substantially U-shaped arc shape when viewed in the direction along the first direction DR1. Furthermore, the concave transport surface SD1 has a substantially U-shaped shape in a cross section perpendicular to the first direction DR1.

[0104] 20, the first intermediate portion 3m-1 of the first transport plate 3-1 has a flat portion FP1 separate from the first recess Q1. The flat portion FP1 extends in the first direction DR1. The first intermediate portion 3m-1 may have a first flat portion FP1-1 and a second flat portion FP1-2.

[0105] 20, the flat portion FP1 (more specifically, the first flat portion FP1-1) and the front edge of the first recess Q1 are connected via a bent portion BC1. Also, in the example shown in FIG. 20, the rear edge of the first recess Q1 and the flat portion FP1 (more specifically, the second flat portion FP1-2) are connected via a bent portion BB1.

[0106] In the example shown in Figure 20, the second front end 3f-2 of the second transport plate 3-2 has a convex curved portion CP2 (more specifically, a convex curved portion CP2 that is convex in the third direction DR3). The convex curved portion CP2 extends in the first direction DR1. Furthermore, the second intermediate portion 3m-2 of the second transport plate 3-2 has a second recess Q2. The second recess Q2 is recessed in the fourth direction DR4 and extends in the first direction DR1.

[0107] The shape of the second recess Q2 is the same as the shape of the first recess Q1, so a repeated description of the shape of the second recess Q2 will be omitted.

[0108] (Fourth Example of Transport Plate 3) In the examples shown in Figures 14, 16, 17, and 19, the first intermediate portion 3m-1 of the first transport plate 3-1 has one first recess Q1. Alternatively, as shown in Figure 21, the first intermediate portion 3m-1 may have two or more first recesses Q1. In the example shown in Figure 21, the first intermediate portion 3m-1 has a first recess Q1-1 and another first recess Q1-2 located on the second direction DR2 side of the first recess Q1. The first recess Q1-1 is recessed in the fourth direction DR4 and extends in the first direction DR1. The other first recess Q1-2 is recessed in the fourth direction DR4 and extends in the first direction DR1.

[0109] 21, each of the first recesses Q1 has a generally arcuate shape when viewed in the first direction DR1. Alternatively, each of the first recesses Q1 may have a generally V-shape or a generally U-shape when viewed in the first direction DR1.

[0110] The configuration in which the first intermediate portion 3m-1 of the first conveying plate 3-1 has another first recess Q1-2 in addition to the first recess Q1-1 can be adopted in any of the first, second, and third examples of the conveying plate 3 described above, or the fifth example of the conveying plate 3 described below.

[0111] (Fifth Example of Transport Plate 3) In the example shown in Figure 22, at least a portion of the first transport surface 3u-1 of the first transport plate 3-1 is formed by the surface of a laser reflecting layer 4-1. In the example shown in Figure 22, the first transport plate 3-1 has a first base member 35-1 and a laser reflecting layer 4-1 that covers at least a portion of the first base member 35-1. The laser reflecting layer 4-1 is formed of a material with high laser reflectivity (e.g., copper). The first base member 35-1 is formed, for example, from steel, more specifically, from a hot-rolled mild steel plate, a cold-rolled steel plate, or a cold-rolled stainless steel plate.

[0112] The laser reflectivity of the laser reflecting layer 4-1 is higher than the laser reflectivity of the first base member 35-1 of the first conveying plate 3-1. In the first embodiment (or the second embodiment described below), the wavelength of the laser LB emitted from the laser irradiation device 60 is, for example, 1060 nm or more and 1080 nm or less. The laser reflectivity of the laser reflecting layer 4-1 for a laser having a wavelength of 1060 nm or more and 1080 nm or less is, for example, 70% or more, 80% or more, or 90% or more.

[0113] 22, a portion of the first transport surface 3u-1 of the first transport plate 3-1 (for example, the transport surface of the flat plate portion FP1) is made up of the surface of the laser reflecting layer 4-1. Also, another portion of the first transport surface 3u-1 of the first transport plate 3-1 (for example, the convex transport surface SU1 and / or the concave transport surface SD1) is made up of a surface (for example, the surface 35u of the first base member 35-1) with a lower laser reflectivity than the laser reflectivity of the laser reflecting layer 4-1.

[0114] Alternatively, as illustrated in Fig. 23, the entire first transport surface 3u-1 of the first transport plate 3-1 may be formed by the surface of the laser reflecting layer 4-1. In Fig. 23, the laser reflecting layers (4-1, 4-2) are hatched with dots to make them easier to understand.

[0115] 22, the laser reflecting layer 4-1 (for example, a copper layer that forms at least a part of the first transport surface 3u-1) that forms at least a part of the first transport surface 3u-1 effectively reflects the laser LB emitted from the laser irradiation device 60. In this way, heat input to the first transport plate 3-1 is suppressed, and thermal deformation and bending of the first transport plate 3-1 are suppressed.

[0116] In the example shown in Figure 22, at least a portion of the second transport surface 3u-2 of the second transport plate 3-2 is formed by the surface of a laser reflecting layer 4-2. In the example shown in Figure 22, the second transport plate 3-2 has a second base member 35-2 and a laser reflecting layer 4-2 that covers at least a portion of the second base member 35-2. The laser reflecting layer 4-2 is formed of a material with high laser reflectivity (e.g., copper). The second base member 35-2 is formed, for example, from steel, more specifically, from a hot-rolled mild steel plate, a cold-rolled steel plate, or a cold-rolled stainless steel plate.

[0117] The aspect in which at least a portion of the transport surface 3u of each transport plate 3 is formed by the surface of the laser reflecting layer 4 can be adopted in any of the first, second, third and fourth examples of the transport plate 3.

[0118] (Size of first recess Q1) When the first conveying plate 3-1 moves in the second direction DR2 across the laser LB emitted from the laser irradiation device 60, it is preferable that the length of the first recess Q1 in the second direction DR2 relative to the length of the first front end 3f-1 in the second direction DR2 is set so that the deflection caused by the laser irradiation to the first front end 3f-1 and the deflection caused by the laser irradiation to the first intermediate portion 3m-1 substantially cancel each other out.

[0119] 24 , in a plan view (in other words, when viewed in the direction along the fourth direction DR4), the size of the first recess Q1 of the first transport plate 3-1 (in other words, the length of the first recess Q1 in the second direction DR2) is, for example, 1 / 3 to 3 times, or 1 / 2 to 2 times, the size of the convex curved portion CP1 of the first transport plate 3-1 (in other words, the length of the convex curved portion CP1 in the second direction DR2). Also, in a plan view (in other words, when viewed in the direction along the fourth direction DR4), the size of the concave transport surface SD1 of the first transport plate 3-1 (in other words, the length of the concave transport surface SD1 in the second direction DR2) is, for example, 1 / 3 to 3 times, or 1 / 2 to 2 times, the size of the convex transport surface SU1 of the first transport plate 3-1 (in other words, the length of the convex transport surface SU1 in the second direction DR2). 24, the concave conveying surface SD1 is hatched with diagonal lines to make it easier to understand, and the convex conveying surface SU1 is hatched with dots to make it easier to understand.

[0120] 25, the depth L2 of the concave conveying surface SD1 (more specifically, the distance in the direction along the third direction DR3 between the point E5 of the concave conveying surface SD1 located closest to the third direction DR3 and the deepest part E6 of the concave conveying surface SD1) is greater than the plate thickness T1 of the first recess Q1. The depth L2 of the concave conveying surface SD1 is, for example, 2 mm or more, 4 mm or more, or 6 mm or more.

[0121] 25, the dross transport conveyor 2A has another transport plate 3-N disposed adjacent to the first front end 3f-1 of the first transport plate 3-1. The first transport plate 3-1 can tilt relative to the other transport plate 3-N about a first axis (hereinafter referred to as the "forward tilt axis AX1"). The first transport plate 3-1 can also tilt relative to the second transport plate 3-2 about a second axis (hereinafter referred to as the "rear tilt axis AX2").

[0122] 25, a plane including both the forward tilt axis AX1 of the first transport plate 3-1 and the rearward tilt axis AX2 of the first transport plate 3-1 is defined as a first plane PL1. In the example shown in FIG. 25, the deepest part E6 of the concave transport surface SD1 is located on the fourth direction DR4 side of the first plane PL1.

[0123] The distance L3 between the deepest part E6 of the concave transfer surface SD1 and the first plane PL1 is, for example, 2 mm or more, 4 mm or more, or 6 mm or more.

[0124] In the example shown in FIG. 25, the end E7 of the first recess Q1 on the fourth direction DR4 side is located closest to the fourth direction DR4 side of the entire first transport plate 3-1.

[0125] 26, the orbit OB of the group of transport plates 3 may include an upward slope CL that increases in height from the processing region RG1 toward the discharge region RG2. When the orbit OB includes an upward slope CL, it is easy to arrange, in the discharge region RG2, a container 13 that receives the dross D from the dross transport conveyor 2A, or a second transport conveyor 15 (see FIG. 32, if necessary) that receives the dross D from the dross transport conveyor 2A.

[0126] 1 , the laser processing apparatus 1A includes a dross transport conveyor 2A, a laser irradiation device 60, a moving device 7, and a control device 8. Additionally, the laser processing apparatus 1A may include a workpiece support member 90.

[0127] The dross transport conveyor 2A has already been explained, so a repeated explanation of the dross transport conveyor 2A will be omitted.

[0128] 27 , the laser irradiation device 60 has a laser head 61, and the laser head 61 has an emission port OP for emitting a laser. The laser irradiation device 60 may include a laser light source 63 and an optical component 65 (e.g., an optical fiber) that transmits a laser from the laser light source 63 to the laser head 61.

[0129] The moving device 7 moves the laser head 61 relative to the workpiece support member 90. The moving device 7 also moves the laser head 61 relative to the workpiece W supported by the workpiece support member 90. The workpiece W supported by the workpiece support member 90 is, for example, a plate material.

[0130] In the example shown in FIG. 27, the moving device 7 has a moving body (71a; 73a) that supports the laser head 61, and a driving device (71b; 73b) that moves the moving body (71a; 73a).

[0131] 27 , the moving device 7 includes a first moving device 71. The first moving device 71 includes a first moving body 71 a that supports the laser head 61, and a first driving device 71 b (e.g., a first motor) that moves the first moving body 71 a.

[0132] 27 , the first moving body 71a functions as a Z saddle, and the first driving device 71b functions as a Z-axis driving unit. The first driving device 71b moves the first moving body 71a in a direction parallel to the vertical direction (in other words, the Z-axis direction). More specifically, the first driving device 71b can move the first moving body 71a downward so that the first moving body 71a approaches the workpiece support member 90. The first driving device 71b can also move the first moving body 71a upward so that the first moving body 71a moves away from the workpiece support member 90.

[0133] 27 , the moving device 7 includes a second moving device 73. The second moving device 73 includes a second moving body 73 a and a second driving device 73 b (e.g., a second motor) that moves the second moving body 73 a. The second moving body 73 a supports the first moving body 71 a so that the first moving body 71 a can move in a direction parallel to the vertical direction.

[0134] 27, the second moving body 73a functions as a Y saddle, and the second driving device 73b functions as a Y-axis driving unit. The second driving device 73b moves the second moving body 73a in a direction parallel to the horizontal plane (more specifically, in the Y-axis direction).

[0135] 28 , the moving device 7 includes a third moving device 75. The third moving device 75 includes a third moving body 75a and a third driving device 75b (e.g., a third motor) that moves the third moving body 75a. The third moving body 75a supports the second moving body 73a so that the second moving body 73a can move in a direction parallel to the Y-axis direction.

[0136] 28, the third movable body 75a functions as an X saddle, and the third driving device 75b functions as an X-axis driving unit. The third driving device 75b moves the third movable body 75a in a direction parallel to the horizontal plane (more specifically, in the X-axis direction perpendicular to the Z-axis and Y-axis).

[0137] As illustrated in Fig. 27, the third movable body 75a may be configured as a gate-shaped structure. In the example illustrated in Fig. 28, the third movable body 75a is movable across the processing region RG1 in a plan view. The third movable body 75a is supported by the base 70 so as to be movable in a direction parallel to the X-axis direction.

[0138] 29, the workpiece support member 90 includes a pin holder for supporting a workpiece W, which is a plate material. The pin holder has a plurality of tops 92 for supporting the workpiece W, which is a plate material.

[0139] 29, the workpiece support member 90 has a plurality of plate members 91 arranged in an upright position relative to a horizontal plane (for example, the XY plane in FIG. 29). Each of the plurality of plate members 91 has a sawtooth edge portion EG.

[0140] The workpiece support member 90 may have 10 or more plate members 91 arranged to stand on a horizontal plane, or may have 20 or more plate members 91 arranged to stand on a horizontal plane. Each plate member 91 is made of, for example, metal.

[0141] 29 , the workpiece support member 90 is a movable pallet PT. The pallet PT has a plurality of plate members 91 and a frame 93 to which the plate members 91 are attached. The bottom of the frame 93 defines a bottom opening. Dross D generated by irradiating the workpiece W with the laser LB falls toward the dross transport conveyor 2A through the space between two adjacent plate members 91 and the bottom opening defined by the frame 93.

[0142] As illustrated in FIG. 30 , the laser processing apparatus 1A may include a transfer device 11 that transfers the workpiece support member 90. The transfer device 11 transfers the workpiece support member 90 from the processing region RG1 to the removal region RG3. Thereafter, the machined workpiece Wb (more specifically, the machined plate material) is removed from the workpiece support member 90 arranged in the removal region RG3. As illustrated in FIG. 31 , the removal may be performed using a suction cup 121 that can suction the machined workpiece Wb, or may be performed using a fork that can scoop up the machined workpiece Wb. Alternatively, the removal may be performed by a robot or an operator.

[0143] 31 , the laser processing apparatus 1A has a workpiece transfer device 12 (e.g., a robot hand) that transfers a workpiece before processing and a processed workpiece Wb. The workpiece transfer device 12 may be a plate material transfer device 12a that transfers a workpiece that is a plate material. The plate material transfer device 12a may have a plurality of suction cups 121 that adsorb the workpiece that is a plate material, or forks that support the workpiece that is a plate material from below.

[0144] 1, the laser processing apparatus 1A has a container 13 that receives the dross D from the dross transport conveyor 2A. The container 13 is disposed directly below the dross transport conveyor 2A in the discharge region RG2.

[0145] The laser processing apparatus 1A may have a second transfer conveyor 15 that receives the dross D from the dross transport conveyor 2A. In the example shown in Fig. 32, the dross transport surface of the second transfer conveyor 15 is disposed directly below the dross transport conveyor 2A in the discharge area RG2. In the example shown in Fig. 32, the second transfer conveyor 15 transports the dross received from the dross transport conveyor 2A to the container 13.

[0146] 33, the control device 8 controls the laser irradiation device 60 and the moving device 7 (e.g., the first driving device 71b, the second driving device 73b, and the third driving device 75b). The control device 8 may also control the transfer device 11 (see FIG. 30) that transfers the work support member 90 and / or the work transfer device 12 (see FIG. 31) that transfers the work W. The control device 8 may also control the drive device 29 of the dross transport conveyor 2A.

[0147] 34 , the control device 8 transmits an emission command R1 to the laser irradiation device 60 (e.g., the laser light source 63), thereby causing the laser head 61 to emit the laser beam LB. More specifically, the control device 8 transmits the emission command R1 to the laser irradiation device 60 (e.g., the laser light source 63), and the laser irradiation device 60 that receives the emission command R1 emits the laser beam LB from the laser head 61 (more specifically, from the emission port of the laser head 61).

[0148] 34 , the control device 8 moves the laser head 61 by transmitting a movement command S to the moving device 7. More specifically, the control device 8 transmits the movement command S to the moving device 7, and the moving device 7 that receives the movement command S moves the laser head 61.

[0149] As illustrated in FIG. 34 , the control device 8 includes a hardware processor 80 (hereinafter simply referred to as the "processor 80"), a memory 82, a communication circuit 84, and an input device 86 (e.g., a touch-panel display 862). The processor 80, the memory 82, the communication circuit 84, and the input device 86 are connected to one another via a bus 88. Data necessary for machining the workpiece W (e.g., workpiece data 826 including shape data of the workpiece W and machining position data of the workpiece W) may be input to the control device 8 via the input device 86, or may be input to the control device 8 from another computer via the communication circuit 84. Note that the input device 86 is not limited to the touch-panel display 862. For example, the control device 8 may include an input device 86 such as a button, a switch, a lever, a pointing device, or a keyboard, and a display that displays the data input to the input device 86 or other information.

[0150] The memory 82 stores data such as workpiece data 826 and programs such as a machining program 822. The memory 82 is a storage medium readable by the processor 80 of the control device 8. The memory 82 may be, for example, a non-volatile or volatile semiconductor memory such as a RAM, a ROM, or a flash memory, a magnetic disk, or any other type of memory.

[0151] The processor 80 of the control device 8 executes the machining program 822 stored in the memory 82, causing the control device 8 to generate control commands. Furthermore, the communication circuit 84 transmits the control commands to the devices to be controlled (more specifically, the laser irradiation device 60, the moving device 7, the transport device 11, the workpiece transport device 12, the driving device 29, etc.). In this way, the processor 80 executes the machining program 822, allowing the control device 8 to control the laser irradiation device 60, the moving device 7, the transport device 11, the workpiece transport device 12, the driving device 29, etc.

[0152] The control device 8 may control the moving speed of the first group of transport plates 3 in conjunction with the control of at least one of the laser irradiation device 60 and the moving device 7 .

[0153] For example, the control device 8 may control the drive device 29 so that the first group of transport plates 3 moves at a first speed (a speed other than zero) when the laser irradiation device 60 stops emitting the laser LB, and may control the drive device 29 so that the first group of transport plates 3 moves at a second speed faster than the first speed when the laser irradiation device 60 emits the laser LB.

[0154] For example, the control device 8 may control the drive device 29 so that the movement speed of the first group of conveying plates 3 is changed depending on the magnitude of the output of the laser LB emitted by the laser irradiation device 60 or the type of processing performed by the laser irradiation device 60 (for example, whether it is drilling, cutting, etc.).

[0155] (Cooling Device 95) As illustrated in FIG. 35, the laser processing apparatus 1A may have a cooling device 95 that forcibly cools the group of transport plates 3.

[0156] For example, the laser processing apparatus 1A may include an air-cooling type cooling device 95a that blows air onto the group of transport plates 3. In the example shown in Fig. 35, the cooling device 95a has an air injection device 96 that blows air onto the back surface 3n of each of the group of transport plates 3. Alternatively, or additionally, the cooling device 95a may have an air injection device that blows air onto the transport surface 3u of each of the group of transport plates 3.

[0157] Alternatively, or additionally, the laser processing apparatus 1A may include a liquid-cooling type cooling device 95b that cools the group of transport plates 3 with liquid. In the example shown in Fig. 35, the cooling device 95b has a liquid tank 97 (e.g., a water tank) that is arranged so that the orbit of the group of transport plates 3 crosses it. The group of transport plates 3 is cooled by passing through the liquid (e.g., water) in the liquid tank 97. Furthermore, the liquid adhering to the surfaces of the group of transport plates 3 is vaporized by laser irradiation (heat of vaporization), thereby suppressing a rise in temperature of the transport plates 3.

[0158] Second Embodiment A dross transport conveyor 2B and a laser processing apparatus 1B according to a second embodiment will be described with reference to FIGS. 36 to 42. FIG. 36 is a schematic cross-sectional view showing a laser processing apparatus 1B according to the second embodiment. FIG. 37 is a schematic cross-sectional view showing a portion of the laser processing apparatus 1B according to the second embodiment. FIG. 38 is an exploded perspective view showing a portion of a group of transport plates 3. FIG. 39 is a schematic perspective view showing a state in which a group of transport plates 3 including a first transport plate 3-1 and a second transport plate 3-2 can move along an orbit OB. FIG. 40 is a schematic cross-sectional view showing a portion of a laser processing apparatus 1B according to the second embodiment. FIG. 41 is an exploded perspective view showing a portion of a group of transport plates 3. FIG. 42 is a schematic cross-sectional view showing a portion of a group of transport plates 3.

[0159] The dross transport conveyor 2B of the second embodiment differs from the dross transport conveyor 2A of the first embodiment in that each of the group of transport plates 3 is hingedly connected to the other transport plates.

[0160] In the second embodiment, differences from the first embodiment will be mainly described. On the other hand, in the second embodiment, repeated descriptions of matters already described in the first embodiment will be omitted. Therefore, it goes without saying that matters already described in the first embodiment can be applied to the second embodiment even if they are not explicitly described in the second embodiment. Conversely, all matters described in the second embodiment can be applied to the first embodiment.

[0161] In the examples shown in Figures 36 and 37, the dross conveying conveyor 2B of the second embodiment includes a group of conveying plates 3 for conveying dross generated by irradiating a workpiece with a laser. The group of conveying plates 3 includes a first conveying plate 3-1 extending in a first direction DR1 and a second conveying plate 3-2 adjacent to the first conveying plate 3-1 and extending in the first direction DR1. As illustrated in Figure 38, the first conveying plate 3-1 includes a first front end 3f-1, a first rear end 3e-1, and a first intermediate portion 3m-1 connecting the first front end 3f-1 and the first rear end 3e-1. The first intermediate portion 3m-1 has a first recess Q1 extending in the first direction DR1.

[0162] In the example shown in Figure 36, the laser processing apparatus 1B in the second embodiment includes the above-mentioned dross transport conveyor 2B, a laser irradiation device 60 including a laser head 61 that irradiates a laser toward the workpiece W, a moving device 7 that moves the laser head 61 relative to a workpiece support member 90 that supports the workpiece W, and a control device 8 that controls the laser irradiation device 60 and the moving device 7.

[0163] Therefore, the dross transport conveyor 2B and the laser processing device 1B in the second embodiment have the same effects as the dross transport conveyor 2A and the laser processing device 1A in the first embodiment.

[0164] As illustrated in Figure 38, the first rear end 3e-1 of the first transport plate 3-1 and the second front end 3f-2 of the second transport plate 3-2 are hingedly connected. In the example shown in Figure 38, a rod (hereinafter referred to as the "second rod RD2") is arranged so that it passes through both the first rear end 3e-1 of the first transport plate 3-1 and the second front end 3f-2 of the second transport plate 3-2, thereby hinge-connecting the first rear end 3e-1 of the first transport plate 3-1 and the second front end 3f-2 of the second transport plate 3-2. Furthermore, a rod (hereinafter referred to as the "third rod RD3") is arranged so that it passes through both the second rear end 3e-2 of the second transport plate 3-2 and the third front end 3f-3 of the third transport plate 3-3, thereby hinge-connecting the second rear end 3e-2 of the second transport plate 3-2 and the third front end 3f-3 of the third transport plate 3-3.

[0165] (Optional Additional Configuration) Next, optional additional configurations that can be employed in the dross transport conveyor 2B and the laser processing apparatus 1B in the second embodiment will be described with reference to FIGS.

[0166] 37, the first recess Q1 is a recess recessed in the fourth direction DR4. The first recess Q1 has a conveying surface that conveys the dross and a back surface that is disposed on the opposite side of the conveying surface.

[0167] The conveying surface of the first recess Q1 is a concave conveying surface SD1 that is concave in the fourth direction DR4. In the example shown in Figure 37, the concave conveying surface SD1 has a generally arc shape in a cross section perpendicular to the first direction DR1. Alternatively, the concave conveying surface SD1 may have a generally V-shape, a generally U-shape, or another shape in a cross section perpendicular to the first direction DR1.

[0168] The back surface of the first recess Q1 is a protruding surface SN1 that protrudes in the fourth direction DR4. In the example shown in Figure 37, the protruding surface SN1 has a generally arc-shaped cross section perpendicular to the first direction DR1. Alternatively, the protruding surface SN1 may have a generally V-shaped cross section perpendicular to the first direction DR1, a generally U-shaped cross section, or another shape.

[0169] 36, a portion of the dross transport conveyor 2B is disposed directly below the laser irradiation device 60. Furthermore, one group of transport plates 3 of the dross transport conveyor 2B is configured to be movable across the processing region RG1 (more specifically, the region directly below the laser irradiation device 60).

[0170] In the example shown in Fig. 36, the first group of transport plates 3 transports dross from the processing region RG1 to the discharge region RG2. In the example shown in Fig. 36, each of the first group of transport plates 3 is reversed in the discharge region RG2 (more specifically, turned 180 degrees around the horizontal axis). As a result, the dross D transported by the first group of transport plates 3 is discharged from the first group of transport plates 3 in the discharge region RG2. Note that when cut-off pieces CF (see Fig. 37) are transported by the first group of transport plates 3, the cut-off pieces CF are also discharged from the first group of transport plates 3 in the discharge region RG2.

[0171] 39 , the dross transport conveyor 2B includes a first endless member 21 (more specifically, a first endless chain 21a), a second endless member 22 (more specifically, a second endless chain 22a), and a drive device 29. The first endless member 21 and the second endless member 22 support a group of transport plates 3. More specifically, the group of transport plates 3 is attached to the first endless member 21 and the second endless member 22.

[0172] The first endless member 21 and the second endless member 22 are driven directly or indirectly by a driving device 29. The first endless member 21, the second endless member 22, and the driving device 29 have already been described in the first embodiment, so a repeated description of these configurations will be omitted.

[0173] (First group of transport plates 3) The first group of transport plates 3 moves along an orbital path OB. As illustrated in Fig. 39, the orbital path OB of the first group of transport plates 3 is parallel to the first orbital path B1 of the first endless chain 21a and parallel to the second orbital path B2 of the second endless chain 22a. In the example shown in Fig. 36, the first group of transport plates 3 are arranged in a continuous manner to form a circular transport body.

[0174] The length of each of the group of transport plates 3 is, for example, 1 m or more and 3 m or less. The width of each of the group of transport plates 3 is, for example, 40 mm or more and 200 mm or less. The plate thickness of each of the group of transport plates 3 (more specifically, the plate thickness of the middle portion 3 m of each of the group of transport plates 3) is, for example, 5 mm or less or 3 mm or less. Each of the group of transport plates 3 is made of metal. Each of the group of transport plates 3 is made of, for example, steel, more specifically, hot-rolled mild steel plate, cold-rolled steel plate, or cold-rolled stainless steel plate.

[0175] 38, the first transport plate 3-1 has a first front end 3f-1, a first rear end 3e-1, and a first intermediate portion 3m-1 connecting the first front end 3f-1 and the first rear end 3e-1. The first front end 3f-1 of the first transport plate 3-1 is formed with a plurality of first front receiving portions 30f-1 (more specifically, a plurality of through-holes into which the first rod RD1 is inserted) for receiving the first rod RD1. Furthermore, the first rear end 3e-1 of the first transport plate 3-1 is formed with a plurality of first rear receiving portions 30e-1 (more specifically, a plurality of through-holes into which the second rod RD2 is inserted).

[0176] 38, the second transport plate 3-2 has a second front end 3f-2, a second rear end 3e-2, and a second intermediate portion 3m-2 connecting the second front end 3f-2 and the second rear end 3e-2. The second front end 3f-2 of the second transport plate 3-2 is formed with a plurality of second front receiving portions 30f-2 (more specifically, a plurality of through-holes into which the second rod RD2 is inserted) for receiving the second rod RD2. The second rear end 3e-2 of the second transport plate 3-2 is formed with a plurality of second rear receiving portions 30e-2 (more specifically, a plurality of through-holes into which the third rod RD3 is inserted) for receiving the third rod RD3.

[0177] (First transport plate 3-1) In the example shown in Figure 37, the first front end 3f-1 of the first transport plate 3-1 has a convex transport surface SU1 that is convex in the third direction DR3. The convex transport surface SU1 constitutes part of the first transport surface 3u-1 of the first transport plate 3-1. In the example shown in Figure 37, the convex transport surface SU1 is the upper surface of the first front receiving section 30f-1. The convex transport surface SU1 extends in the first direction DR1. In the example shown in Figure 37, the convex transport surface SU1 has a substantially arc-shaped configuration when viewed in the direction along the first direction DR1. Furthermore, the convex transport surface SU1 has a substantially arc-shaped configuration in a cross section perpendicular to the first direction DR1.

[0178] When the laser beam LB is irradiated onto the convex transport surface SU1 of the first transport plate 3-1, the first front end portion 3f-1 (or the first transport plate 3-1) thermally bends in the third direction DR3.

[0179] 37, the first intermediate portion 3m-1 (more specifically, the first recess Q1) of the first transport plate 3-1 has a recessed transport surface SD1 that is recessed in the fourth direction DR4. The recessed transport surface SD1 extends in the first direction DR1.

[0180] When the laser beam LB is irradiated onto the concave transport surface SD1 of the first transport plate 3-1, the first intermediate portion 3m-1 (or the first transport plate 3-1) thermally bends in the fourth direction DR4.

[0181] Since the direction in which the first front end 3f-1 thermally bends when laser LB is irradiated onto the convex conveying surface SU1 of the first conveying plate 3-1 is opposite to the direction in which the first intermediate portion 3m-1 thermally bends when laser LB is irradiated onto the first recess Q1 (or the concave conveying surface SD1), thermal deformation of the first conveying plate 3-1 as a whole is suppressed.

[0182] 37 and 38, the first recess Q1, the recessed conveying surface SD1, and the protruding surface SN1 each have a substantially arc shape in a cross section perpendicular to the first direction DR1. Also, when viewed in a direction along the first direction DR1, the first recess Q1, the recessed conveying surface SD1, and the protruding surface SN1 each have a substantially arc shape.

[0183] 40 and 41 , in a cross section perpendicular to the first direction DR1, the first recess Q1, the recessed conveying surface SD1, and the protruding surface SN1 may each have a substantially U-shape. Also, when viewed in the direction along the first direction DR1, the first recess Q1, the recessed conveying surface SD1, and the protruding surface SN1 may each have a substantially U-shape. Furthermore, when viewed in the direction along the first direction DR1, the first recess Q1, the recessed conveying surface SD1, and the protruding surface SN1 may each have a substantially V-shape.

[0184] In the example shown in Figure 40, the first intermediate portion 3m-1 of the first transport plate 3-1 has a first recess Q1. The first intermediate portion 3m-1 also has a flat portion FP1 separate from the first recess Q1. The first recess Q1 and the flat portion FP1 are connected via a bent portion BC1. As shown in Figure 41, the first recess Q1, the flat portion FP1, and the bent portion BC1 each extend in the first direction DR1.

[0185] 41, the first intermediate portion 3m-1 may have a first flat plate portion FP1-1, a second flat plate portion FP1-2, and a first recess Q1 disposed between the first flat plate portion FP1-1 and the second flat plate portion FP1-2. In the example shown in FIG. 41, the first flat plate portion FP1-1 is connected to the first front end portion 3f-1, and the second flat plate portion FP1-2 is connected to the first rear end portion 3e-1.

[0186] In the example shown in FIG. 41, the second transport plate 3-2 and the third transport plate 3-3 each have the same shape as the first transport plate 3-1.

[0187] 42, the depth L2 of the concave conveying surface SD1 (more specifically, the distance in the direction along the third direction DR3 between the point E5 of the concave conveying surface SD1 located closest to the third direction DR3 and the deepest part E6 of the concave conveying surface SD1) is greater than the plate thickness T1 of the first concave recess Q1. The depth L2 of the concave conveying surface SD1 is, for example, 2 mm or more, 4 mm or more, or 6 mm or more.

[0188] 42, the dross transport conveyor 2B has another transport plate 3-N disposed adjacent to the first front end 3f-1 of the first transport plate 3-1. The first transport plate 3-1 can tilt relative to the other transport plate 3-N about a forward tilting axis AX1. The first transport plate 3-1 can also tilt relative to the second transport plate 3-2 about a rearward tilting axis AX2.

[0189] 42, a plane including both the forward tilting axis AX1 of the first transport plate 3-1 and the rearward tilting axis AX2 of the first transport plate 3-1 is defined as a first plane PL1. In the example shown in FIG. 25, the deepest part E6 of the concave transport surface SD1 is located on the fourth direction DR4 side of the first plane PL1.

[0190] The distance L3 between the deepest part E6 of the concave transfer surface SD1 and the first plane PL1 is, for example, 2 mm or more, 4 mm or more, or 6 mm or more.

[0191] In the example shown in FIG. 42, the end E7 of the first recess Q1 on the fourth direction DR4 side is located closest to the fourth direction DR4 side of the entire first transport plate 3-1.

[0192] 36, the laser processing apparatus 1B includes a dross transport conveyor 2B, a laser irradiation device 60, a moving device 7, and a control device 8. Additionally, the laser processing apparatus 1B may include a workpiece support member 90. The laser irradiation device 60, the moving device 7, the control device 8, and the workpiece support member 90 have already been described in the first embodiment, and therefore, repeated description of these configurations will be omitted.

[0193] Third Embodiment A workpiece machining method according to a third embodiment will be described with reference to Figures 1 to 43. Figure 43 is a flowchart showing an example of the workpiece machining method according to the third embodiment.

[0194] The workpiece processing method in the third embodiment may be performed using the laser processing apparatus 1A in the first embodiment, the laser processing apparatus 1B in the second embodiment, or any other laser processing apparatus.

[0195] In the first step ST1, the workpiece W is machined. The first step ST1 is a workpiece machining process. In the workpiece machining process, the workpiece W is machined by irradiating the workpiece W with a laser LB. More specifically, the workpiece W is machined by irradiating the workpiece W with the laser LB from the laser head 61 of the laser irradiation device 60. The wavelength of the laser LB emitted from the laser head 61 of the laser irradiation device 60 is, for example, not less than 1060 nm and not more than 1080 nm.

[0196] The workpiece W to be machined in the workpiece machining process (first step ST1) is, for example, a plate material. The workpiece machining process may include laser cutting the workpiece W by moving a laser head 61 that emits a laser beam LB. The workpiece machining process may also include laser perforating the workpiece W by emitting a laser beam LB from a laser head 61 that is temporarily stationary. A product (for example, a plate product) is formed from the workpiece W by machining the workpiece W with the laser beam LB.

[0197] In the workpiece machining process (first step ST1), dross D is generated from the workpiece W by irradiating the workpiece W with a laser LB. Additionally, cutting pieces CF may be generated from the workpiece W by irradiating the workpiece W with the laser LB. The generated dross D and / or cutting pieces CF fall downward in the machining region RG1. The dross D and / or cutting pieces CF that fall downward are received by the dross transport conveyor 2.

[0198] In the workpiece machining process (first step ST1), the laser LB passing through the workpiece W reaches the dross transport conveyor 2. The laser LB reaching the dross transport conveyor 2 raises the temperature of a group of transport plates 3 including the first transport plate 3-1 and the second transport plate 3-2. The first transport plate 3-1, the second transport plate 3-2, etc. are deformed due to thermal expansion.

[0199] In the second step ST2, the dross D is transported. The second step ST2 is a dross transport process. In the dross transport process, the dross D generated by irradiating the workpiece W with the laser LB is transported using a group of transport plates 3 including a first transport plate 3-1 extending in the first direction DR1 and a second transport plate 3-2 arranged adjacent to the first transport plate 3-1 and extending in the first direction DR1. More specifically, the group of transport plates 3 transports the dross D from the processing region RG1 to the discharge region RG2.

[0200] As illustrated in Figures 15, 18, 20, 23, 38, and 41, the first transport plate 3-1 has a first front end 3f-1, a first rear end 3e-1, and a first intermediate portion 3m-1 connecting the first front end 3f-1 and the first rear end 3e-1. The first intermediate portion 3m-1 has a first recess Q1 extending in the first direction DR1. The second transport plate 3-2 has a second front end 3f-2, a second rear end 3e-2, and a second intermediate portion 3m-2 connecting the second front end 3f-2 and the second rear end 3e-2. The second intermediate portion 3m-2 has a second recess Q2 extending in the first direction DR1.

[0201] The second step ST2 (dross transport step) is performed in parallel with the first step ST1 (workpiece machining step). More specifically, while the dross transport conveyor 2 is being driven (in other words, while a group of transport plates 3 is moving along the circular orbit OB), the laser irradiator 60 irradiates the workpiece W with a laser LB. By irradiating the workpiece W with the laser LB, dross D and / or cut-off pieces CF are intermittently or continuously generated, and the generated dross D and / or cut-off pieces CF are sequentially transported by the dross transport conveyor 2.

[0202] 14, 16, 17, 19, 21, 22, 37, or 40, the workpiece machining process (the process of machining the workpiece W) is performed in a state in which thermal bending of the first transport plate 3-1 is suppressed because the direction in which the first intermediate portion 3m-1 thermally bends when the first recess Q1 is irradiated with the laser LB is opposite to the direction in which the first front end 3f-1 thermally bends when the first front end 3f-1 is irradiated with the laser LB (see the direction of thermal bending shown in FIGS. 6 and 7 if necessary). Therefore, although the first transport plate 3-1 thermally deforms due to the laser irradiation, large thermal deformation that would result in thermoplastic deformation is suppressed.

[0203] 14, 16, 17, 19, 21, 22, 37, or 40, the workpiece machining process (the process of machining the workpiece W) is performed in a state in which thermal bending of the second transport plate 3-2 is suppressed because the direction in which the second intermediate portion 3m-2 thermally bends as a result of the laser LB being irradiated onto the second recess Q2 is opposite to the direction in which the second front end 3f-2 thermally bends as a result of the laser LB being irradiated onto the second front end 3f-2. Thus, although the second transport plate 3-2 thermally deforms due to the laser irradiation, large thermal deformation that would result in thermoplastic deformation is suppressed.

[0204] In the third step ST3, the first group of transport plates 3 is cooled. The third step ST3 is a cooling step. The cooling step (third step ST3) is performed by, for example, natural cooling. More specifically, the cooling step is performed by leaving the first group of transport plates 3 at room temperature after the processing of the workpieces W is completed.

[0205] Additionally, the cooling step may include forcibly cooling the group of transport plates 3 using at least one of an air-cooling type cooling device 95a and a liquid-cooling type cooling device 95b. For example, as illustrated in Fig. 35, the cooling step may include an air-cooling type cooling device 95a blowing air onto the group of transport plates 3. Alternatively, or additionally, the cooling step may include passing the group of transport plates 3 through a liquid (e.g., water) in a liquid bath 97. Furthermore, the cooling step may include a liquid-cooling type cooling device 95b spraying liquid (e.g., water) onto the group of transport plates 3.

[0206] Forced cooling of a group of transport plates 3 using at least one of an air-cooled cooling device 95a and a liquid-cooled cooling device 95b may be carried out in parallel with the workpiece processing process (first step ST1) and the dross transport process (second step ST2).

[0207] In the workpiece processing method of the third embodiment, the thermoplastic deformation of the first transport plate 3-1 is suppressed, so that the first transport plate 3-1 returns to its original shape before thermal deformation after being cooled in the cooling process. Furthermore, in the workpiece processing method of the third embodiment, the thermoplastic deformation of the second transport plate 3-2 is suppressed, so that the second transport plate 3-2 returns to its original shape before thermal deformation after being cooled in the cooling process. By repeatedly performing the first step ST1 to the third step ST3 described above, some plastic deformation may occur in each of the group of transport plates 3, but plastic deformation to the extent that it would interfere with the operation of the dross transport conveyor 2 is avoided.

[0208] The present invention is not limited to the above-described embodiments or modifications, and it is clear that each embodiment or modification can be appropriately modified or changed within the scope of the technical concept of the present invention. Furthermore, various techniques used in each embodiment or modification can be applied to other embodiments or modifications as long as no technical contradiction occurs. Furthermore, optional additional configurations in each embodiment or modification can be omitted as appropriate.

[0209] 1, 1A, 1B... laser processing device, 2, 2A, 2B... dross transport conveyor, 3... transport plate, 3'... transport plate, 3-1... first transport plate, 3-2... second transport plate, 3-3... third transport plate, 3-N... transport plate, 3a, 3a-1, 3a-2, 3a-3... left end, 3b, 3b-1, 3b-2, 3b-3... right end, 3e... rear end, 3e-1... first rear end, 3e-2... second rear end, 3e-3... third rear end, 3e-N... rear end of transport plate 3-N, 3f... front end, 3f-1... first front end, 3f-2... second front end, 3f-3... third front end, 3m... Intermediate portion, 3m-1...first intermediate portion, 3m-2...second intermediate portion, 3m-3...third intermediate portion, 3n...reverse surface, 3n-1...first reverse surface, 3n-2...second reverse surface, 3u...transport surface, 3u-1...first transport surface, 3u-2...second transport surface, 4, 4-1, 4-2...laser reflecting layer, 7...moving device, 8...control device, 11...transport device, 12...workpiece transport device, 12a...plate material transport device, 13...container, 15...second transport conveyor, 21...first endless member, 21a...first endless chain, 22...second endless member, 22a...second endless chain, 28...sprocket, 28a...first sprocket, 28b...second Sprocket, 28c...third sprocket, 28d...fourth sprocket, 29...drive device, 30e-1...first rear receiving section, 30e-2...second rear receiving section, 30f-1...first front receiving section, 30f-2...second front receiving section, 35-1...first base member, 35-2...second base member, 35u...surface of first base member, 60...laser irradiation device, 61...laser head, 63...laser light source, 65...optical component, 70...base, 71...first moving device, 71a...first moving body, 71b...first driving device, 73...second moving device, 73a...second moving body, 73b...second driving device, 75...second 3 moving device, 75a...third moving body, 75b...third driving device, 80...hardware processor, 82...memory, 84...communication circuit, 86...input device, 88...bus, 90...workpiece support member, 91...plate member, 92...top, 93...frame, 95, 95a, 95b...cooling device, 96...air injection device, 97...liquid tank, 121...suction cup, 822...machining program, 826...workpiece data, 862...touch panel display, AX1...forward tilt axis, AX2...backward tilt axis, B1...first orbit, B2...second orbit, BA1...first bending portion, BA2...second bending portion, BB1, BB2,BC1...bent portion, BT...bolt, C1...boundary portion, CF...cut-off piece, CL...upward slope, CP, CP1, CP2...convex curved portion, D...dross, DR1...first direction, DR2...second direction, DR3...third direction, DR4...fourth direction, E1...rear end edge of transport plate 3-N, E2...front leading edge of second transport plate, E3...rear end edge of first transport plate, E4...third Front tip edge of the transport plate, E5...point located furthest on the third direction side of the concave transport surface, E6...deepest part of the concave transport surface, E7...end of the first recess on the fourth direction side, EG...edge portion, FP1...flat plate portion, FP1-1...first flat plate portion, FP1-2...second flat plate portion, FP2...flat plate portion, G1...distance between the first and second orbits, L1...length of the first transport plate, L2... Depth of concave conveying surface, L3...distance between the deepest part of the concave conveying surface and the first plane, LB...laser, OB...circular orbit, OP...injection port, PL1...first plane, PT...pallet, Q1, Q1-1, Q1-2...first recess, Q2...second recess, QP1, QP2...concave curved portion, R1...injection command, RD1...first rod, RD2...second rod, RD3...third rod, RG1...processing Area, RG2...discharge area, RG3...removal area, S...movement command, SD1, SD2...concave transport surface, SN1...protruding surface, SU1, SU2...convex transport surface, T1...plate thickness of first recess, TP...standing portion, TP1...first standing portion, TP2...second standing portion, W...work, Wb...machined work, W1...width of first transport plate, W2...width of second transport plate, h1, h2...hole portion,

Claims

1. A dross conveyor comprising a first conveying plate extending in a first direction and a second conveying plate adjacent to the first conveying plate and extending in the first direction, the dross conveyor being configured to convey dross generated by irradiating a workpiece with a laser, wherein the first conveying plate includes a first front end, a first rear end, and a first recess extending in the first direction, and a first intermediate portion connecting the first front end and the first rear end.

2. The dross conveyor according to claim 1, wherein the direction in which the first front end is thermally bent by irradiating the first front end with the laser is opposite to the direction in which the first intermediate portion is thermally bent by irradiating the first recess with the laser.

3. The dross conveyor according to claim 1 or 2, wherein in a cross-section perpendicular to the first direction, the first recess has a substantially arc shape, a substantially V shape, or a substantially U shape.

4. The dross conveyor according to any one of claims 1 to 3, wherein the first rear end of the first conveying plate is arranged to overlap with the second front end of the second conveying plate.

5. The dross conveyor according to any one of claims 1 to 3, wherein the first rear end of the first conveying plate and the second front end of the second conveying plate are hinged.

6. When a direction from the back surface of the first conveying plate toward the conveying surface of the first conveying plate is defined as a third direction and a direction opposite to the third direction is defined as a fourth direction, the first recess is recessed in the fourth direction, the first front end has a convex conveying surface convex in the third direction, and the first intermediate portion has a concave conveying surface recessed in the fourth direction. The dross conveyor according to any one of claims 1 to 5.

7. The dross conveyor according to claim 6, wherein the depth of the concave conveying surface is greater than the plate thickness of the first recess.

8. The dross conveyor according to any one of claims 1 to 4, wherein the first front end has a convex curved portion extending in the first direction.

9. The dross conveyor according to any one of claims 1 to 4, wherein a substantially S shape is formed by the first front end and the first recess when viewed in the direction along the first direction.

10. The dross conveying conveyor according to any one of claims 1 to 9, wherein the first intermediate portion has a flat plate portion separately from the first concave portion.

11. The dross conveying conveyor according to claim 10, wherein the first concave portion and the flat plate portion are connected via a bent portion extending in the first direction.

12. The dross conveying conveyor according to any one of claims 1 to 11, wherein at least a part of the conveying surface of the first conveying plate is constituted by the surface of the laser reflection layer.

13. A laser processing apparatus comprising: a laser irradiation device including a laser head that irradiates a laser toward a workpiece; a moving device that relatively moves the laser head with respect to a workpiece support member that supports the workpiece; a control device that controls the laser irradiation device and the moving device; and a dross conveying conveyor, wherein the dross conveying conveyor includes a first conveying plate extending in a first direction and a second conveying plate arranged adjacent to the first conveying plate and extending in the first direction, and includes a group of conveying plates that convey dross generated by irradiating the workpiece with the laser, and the first conveying plate includes a first front end portion, a first rear end portion, and a first concave portion extending in the first direction, and a first intermediate portion that connects the first front end portion and the first rear end portion.

14. The laser processing apparatus according to claim 13, further comprising a cooling device that forcibly cools the group of conveying plates.

15. A step of processing the workpiece by irradiating the workpiece with a laser; and a step of conveying dross generated by irradiating the workpiece with the laser, using a group of conveying plates including a first conveying plate extending in a first direction and a second conveying plate extending in the first direction and disposed adjacent to the first conveying plate, wherein the first conveying plate has a first front end portion, a first rear end portion, and a first recess extending in the first direction, and a first intermediate portion connecting the first front end portion and the first rear end portion, and the step of processing the workpiece is performed in a state where thermal bending of the first conveying plate is suppressed because a direction in which the first intermediate portion is thermally bent by irradiating the first recess with the laser is opposite to a direction in which the first front end portion is thermally bent by irradiating the first front end portion with the laser.

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