Presser plate and edge folding device

Abstract

To provide a presser plate and an edge folding device capable of suppressing an occurrence of tears and wrinkles in packaging paper.SOLUTION: There is provided a presser plate for pressing an end surface covering portion against an axial end surface of a metal strip coil, the presser plate being attached to an arm tip of a multi-joint robot provided in an edge folding device for folding an edge of the end surface covering portion which is a part of a packaging material for packaging the metal strip coil and covers the axial end surface of the metal strip coil. An outer edge serving as a leading side in a travel direction in which the presser plate is moved when forming a valley fold in the packaging material is chamfered on a pressing surface side that contacts the packaging material. This is suitable, when forming valley folds, for smoothly forming folds near an outermost periphery of the metal strip coil without damaging the packaging material. In plan view, it has an asymmetric convex shape in a direction of travel, and all of its apexes including its tip are rounded so that no part other than its tip in the direction of travel extends to the outermost periphery of the metal strip coil.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a pressing plate attached to the end of an arm of a multi-joint robot equipped in an edge folding device, and to an edge folding device equipped with a multi-joint robot. [Background technology]

[0002] The metal strip rolled by the rolling mill is wound by a winding machine and transported in the form of a coil, and this metal strip coil is usually packed in a packaging material to prevent damage, etc. The packaging material used is wider than the width of the metal strip coil. The packaging material covers the side (curved surface) of the cylindrical metal strip coil, and is placed over the metal strip coil so that the end surface covering portion, which is the portion covering the axial end surface of the metal strip coil, protrudes from the metal strip coil in the coil axial direction. Then, a number of folds (folded portions) are formed in this end surface covering portion by a folding operation, and the end surface covering portion covers the axial end surface of the metal strip coil in a manner that it is in close contact with the metal strip coil.

[0003] Patent Document 1 discloses a device for folding edges of packing paper used in packaging a metal strip coil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-156610 Summary of the Invention [Problem to be solved by the invention]

[0005] The folding operation of the edges of packaging materials for coils (metal strip coils) is one of the most delicate operations in coil packaging, as it must be free of tears that impair the functionality of the packaging itself, wrinkles that impair the appearance quality, and other defects that may impede the folding operation. However, the device in Patent Document 1 does not take into consideration tears and wrinkles in the packaging material that may occur during the folding operation.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a pressure plate and edge folding device that can form good folds throughout the entire radial direction of a metal strip coil while suppressing tears and wrinkles in the packaging material. [Means for solving the problem]

[0007] The present application includes a number of means for solving the above-mentioned problems, and one example thereof is a pressure plate that is attached to the end of an arm of a multi-joint robot provided in an edge folding device that folds the edge of an end covering portion, which is a part of a packaging material for packaging a metal strip coil and covers the axial end face of the metal strip coil, and is used to press the end covering portion against the axial end face of the metal strip coil. The outer edge of the part that is the leading side in the traveling direction, which is the direction in which the pressure plate is moved when forming a valley fold in the packaging material, is chamfered on the side of the pressing surface that contacts the packaging material, and is suitable for smoothly forming the fold up to the vicinity of the outermost periphery of the metal strip coil without damaging the packaging material when forming the valley fold. The pressure plate has a convex shape that is asymmetrical with respect to the traveling direction in a plan view, so that no part other than the tip in the traveling direction reaches the outermost periphery of the metal strip coil, and the tip is rounded. Effect of the Invention

[0008] According to the present invention, there is provided a pressure plate and edge folding device that can form good folds over the entire radial direction of a metal strip coil while suppressing tears and wrinkles in the packaging material. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a diagram showing one embodiment of a edge folding device. [Diagram 2] 4A to 4C are diagrams illustrating an example of a configuration of a first end effector. [Diagram 3] 11 is a diagram showing an example of the configuration of a second end effector. FIG. [Figure 4] 1A and 1B are diagrams showing an embodiment of a pressing plate of the present invention. [Diagram 5] FIG. 2 is a diagram showing the state of the metal strip coil up to the coil packaging stage. [Figure 6] 4A to 4C are diagrams illustrating first operations of the first articulated robot and the second articulated robot. [Figure 7] 13A and 13B are diagrams illustrating second operations of the first articulated robot and the second articulated robot. [Figure 8] 13A to 13C are diagrams illustrating third operations of the first articulated robot and the second articulated robot. [Figure 9] FIG. 11 is a diagram showing a fourth operation of the first articulated robot and the second articulated robot. [Figure 10] FIG. 13 is a diagram showing an example of a comparative example in which the shape of the pleats is defective. [Figure 11] 13A and 13B are diagrams illustrating an example of a procedure for stabilizing the pleat shape. [Figure 12] 13A and 13B are diagrams illustrating an example of a procedure for stabilizing the pleat shape. [Figure 13] 13A and 13B are diagrams illustrating an example of a procedure for stabilizing the pleat shape. [Figure 14] 13A and 13B are diagrams illustrating an example of a procedure for stabilizing the pleat shape. [Figure 15] 6A and 6B are diagrams illustrating an example of a pleat shape formed by a pressing plate according to the present embodiment. [Figure 16] FIG. 11 is a diagram showing a fifth operation of the first articulated robot and the second articulated robot. [Figure 17] 13 is a diagram showing an example of a comparative example in which tearing of packaging paper occurs. FIG. [Figure 18] 13 is a diagram showing an example of a comparative example in which tearing of packaging paper occurs. FIG. [Figure 19] 11A and 11B are diagrams illustrating an example of the formation of a valley fold line by a pressing plate according to the present embodiment. [Figure 20] 13 is a diagram showing an example of a case where a collision occurs with wrinkles in packaging paper as a comparative example. FIG. [Figure 21] 11A and 11B are diagrams illustrating an example of a state in which the pressing plate of the present embodiment is moving. [Figure 22] FIG. 13 is a diagram showing an example of a winding misalignment at the outermost periphery of a coil. [Diagram 23]13 is a diagram showing an example of a comparative example in which a rectangular pressing plate collides with the outermost periphery of a coil. FIG. [Figure 24] 11A and 11B are diagrams illustrating an example of how the pressing plate of the present embodiment prevents collision with a miswinding of the outermost periphery of the coil. [Diagram 25] FIG. 13 is a diagram showing a sixth operation of the first articulated robot and the second articulated robot. [Figure 26] FIG. 11 is a diagram showing an example of wrinkle flow as a comparative example. [Figure 27] FIG. 11 is a diagram showing an example of wrinkle flow as a comparative example. [Figure 28] 11A and 11B are diagrams illustrating an example of the flow of wrinkles caused by the pressing plate of the present embodiment. [Figure 29] FIG. 13 is a diagram showing a seventh operation of the first articulated robot and the second articulated robot. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an embodiment of an edge folding device 100 of the present invention. The edge folding device 100 is a device that automatically performs an edge folding operation of an end surface covering part, which is a part of a packaging material for packaging a cylindrical metal strip coil (see FIG. 5 described later) and covers an axial end surface of the metal strip coil (also called a "coil"). As the packaging material, it is preferable to use a paper sheet (packaging paper) as in this embodiment, but the packaging material is not limited to this, and a sheet material generally used for packaging metal strip coils, such as a resin sheet, can also be used. The details of the edge folding operation will be described later. As shown in FIG. 1, the edge folding device 100 includes a relative position detection unit 10, a control unit 20, and a robot unit 90. The relative position detection unit 10, the control unit 20, and the robot unit 90 can transmit and receive information to each other using wired communication or wireless communication.

[0011] The relative position detection unit 10 can detect relative position information regarding the relative position between the robot unit 90 and the metal strip coil. The robot unit 90 can perform edge folding of the end surface covering part of the packing paper that covers the side surface (curved surface) of the metal strip coil. The control unit 20 can control the robot unit 90 based on the relative position information detected by the relative position detection unit 10. With this configuration, even if the metal strip coil to be edge folded (packaged) is not placed in a predetermined position, the relative position detection unit 10 can detect relative position information regarding the relative position between the robot unit 90 and the metal strip coil and control the robot unit 90 based on the detected relative position information. Therefore, it is not necessary to place the metal strip coil in a fixed position, and the position can be changed, so that the degree of freedom of the equipment layout can be increased. Details of each unit will be described below.

[0012] The relative position detection unit 10 includes a LiDAR (Light Detection And Ranging) sensor 11 that functions as a three-dimensional measuring device, a calculation unit 12, and an output unit 13. The LiDAR sensor 11 irradiates laser light and detects reflected light and scattered light, which can be used to measure the distance to the metal strip coil and calculate the shape. The LiDAR sensor 11 can also generate a high-resolution 3D image of the metal strip coil by including a camera. The LiDAR sensor 11 can detect three-dimensional position information of the metal strip coil.

[0013] The calculation unit 12 can calculate relative position information regarding the relative positions of the robot unit 90 and the metal strip coil based on the position information of the robot unit 90 and three-dimensional information of the metal strip coil detected by the LiDAR sensor 11. The position information of the robot unit 90 may be stored in the memory unit 24 of the control unit 20, for example, and may be acquired from the memory unit 24.

[0014] The output unit 13 outputs the relative position information calculated (detected) by the calculation unit 12 to the control unit 20. This allows the control unit 20 to obtain relative position information between the robot unit 90 and the metal strip coil according to the position of the metal strip coil, regardless of the arrangement position of the metal strip coil.

[0015] The robot section 90 includes a first articulated robot 70, a second articulated robot 80, and a moving section 60. The first articulated robot 70 and the second articulated robot 80 are attached to the moving section 60, and the moving section 60 enables the first articulated robot 70 and the second articulated robot 80 to move in parallel and rotate. In this embodiment, a collaborative robot that can cooperate with humans is used as the first articulated robot 70 and the second articulated robot 80. The control section 20 can control the moving section 60 to move the edge folding robot to a position where the metal strip coil and the edge folding robot are arranged in a predetermined manner based on the relative position information. This eliminates the need to arrange the metal strip coil in a fixed position, and the arrangement can be changed, thereby increasing the freedom of facility layout.

[0016] The moving unit 60 includes a rotating platform 30, a lifting unit 40, and a moving cart 50. The rotating platform 30 is fixed to the lifting unit 40 and includes a driving unit 31 and a robot table 32. The lifting unit 40 is installed on the moving cart 50 and includes a driving unit 41. The moving cart 50 includes a driving unit 51. The first articulated robot 70 and the second articulated robot 80 are attached to the robot table 32 (rotating platform 30). The driving unit 31 is composed of, for example, a servo motor, and when it receives a control signal from the control unit 20, it can rotate the robot table 32 (rotating platform 30) around a rotation axis based on the received control signal. The central axis of rotation of the robot table 32 is oriented in the horizontal direction. Note that the central axis of rotation of the robot table 32 is not limited to the horizontal direction, and may be oriented in a direction tilted by a predetermined angle from the horizontal direction according to the installation state of the metal strip coil. By setting the central axis of rotation of the robot table 32 in a predetermined direction, a reference direction can be set for the manipulation of packaging paper by the first articulated robot 70 and the second articulated robot 80. The relative position detection unit 10 may be provided at a predetermined position on the turntable 30 (for example, a portion other than the robot table 32). The positional relationship between the attachment position of the relative position detection unit 10, a predetermined position on the central axis of rotation of the robot table 32, and the direction of the central axis can be determined in advance.

[0017] The driving unit 51 is, for example, a combination of a servo motor and a transmission mechanism, and when it receives a control signal from the control unit 20, it can move the moving cart 50 in a two-dimensional horizontal direction on the floor surface based on the received control signal. The driving unit 41 is, for example, a combination of a servo motor and a transmission mechanism, and when it receives a control signal from the control unit 20, it can raise and lower the rotating table 30 based on the received control signal. In this way, the control unit 20 can move the lifting unit 40 horizontally by sending a control signal to the driving unit 51 to move the moving cart 50 in the horizontal direction. Also, the control unit 20 can raise and lower the rotating table 30 by sending a control signal to the driving unit 41 to move the lifting unit 40 in the vertical direction. Also, the control unit 20 can rotate the robot table 32 by sending a control signal to the driving unit 31.

[0018] The first articulated robot 70 may be, for example, a six-axis robot. The six-axis robot has six degrees of freedom in total in the X-axis direction, the Y-axis direction, the Z-axis direction, around the X-axis, around the Y-axis, and around the Z-axis in a three-dimensional space (XYZ-axis coordinate system). The first articulated robot 70 includes a plurality of joints having rotation axes, a plurality of links connecting the joints, and includes a first end effector 71 at the tip. The second articulated robot 80 is also similarly configured as a six-axis robot, and includes a second end effector 81 at the tip. Note that an operation program is created for the first articulated robot 70 and the second articulated robot 80 so that the robots can perform a predetermined task in a predetermined procedure, and the operation program can be stored in, for example, the storage unit 24.

[0019] When the first articulated robot 70 and the second articulated robot 80 receive a control signal from the control unit 20, they can perform a predetermined task in a predetermined procedure based on the received control signal. In this case, the control signal may be a signal for starting or stopping the operation of the first articulated robot 70 and the second articulated robot 80, and a device for storing specific procedures and operations may be built into the first articulated robot 70 and the second articulated robot 80.

[0020] By using a multi-joint robot, the position and posture of the first end effector 71 and the second end effector 81 can be controlled, making it possible to work in three-dimensional space, thereby reproducing the packaging work (edge ​​folding work) performed manually by humans.

[0021] The control unit 20 comprises a CPU (Central Processing Unit) 21, a RAM (Random Access Memory) 22, a ROM (Read Only Memory) 23, a storage unit 24, and an interface unit 25. The control unit 20 may be configured, for example, as an information processing device such as a personal computer. The storage unit 24 may be configured as a semiconductor memory or a hard disk, and can store the operation program of the edge folding device 100, processing results, and other required information. The interface unit 25 comprises a communication module and can transmit and receive information between the relative position detection unit 10 and the robot unit 90.

[0022] FIG. 2 is a diagram showing an example of the configuration of the first end effector 71. The first end effector 71 includes a pressing plate 72, a roll portion 714 on which the adhesive tape is wound in a roll shape, and an attaching portion 713 for cutting the adhesive tape wound on the roll portion 714 to a required size and attaching the cut adhesive tape. The pressing plate 72 is for pressing the end surface covering portion of the packing paper to the axial end surface of the metal strip coil. The pressing plate 72 will be described in detail later. The attaching portion 713 is for fixing the edge folded portion of the packing paper by attaching the adhesive tape cut to a required size to the packing paper. The first end effector 71 can be rotated along the direction indicated by the symbol A in FIG. 2 and can be moved along the direction indicated by the symbol B. The attaching portion 713 can be moved along the direction indicated by the symbol B while maintaining the position of the pressing plate 72.

[0023] FIG. 3 is a diagram showing an example of the configuration of the second end effector 81. The second end effector 81 includes grippers 811 and 812. The grippers 811 and 812 are collectively referred to as the gripper 81. The grippers 811 and 812 can be formed of flat plates of a required shape. The grippers 811 and 812 can be rotated around a specified axis. The gripper 81 can grip the end of the end surface covering part of the packing paper. Specifically, the grippers 811 and 812 can pinch and grip the end of the end surface covering part of the packing paper from both sides. The second end effector 81 can rotate along the direction indicated by the symbol A in FIG. 3 and can move along the direction indicated by the symbol B. The gripper 81 has a gripping detection function that applies force control.

[0024] This makes it possible to grip the end of the end surface covering portion of the packing paper, move or rotate the end in a required direction, and maintain the position of the end in a gripped state.

[0025] Fig. 4 is a diagram showing one embodiment of the pressing plate 72 of the present invention. Fig. 4A shows the front shape of the pressing plate 72, Fig. 4B shows the side shape as seen from the reference character BB in Fig. 4A, and Fig. 4C shows the cross-sectional shape at the reference character CC in Fig. 4A. The pressing plate 72 is attached to the tip of an arm of an articulated robot 70 provided in an edge folding device 100 which folds edges of an end face covering portion 301, which is a part of a packing paper 300 for packing the metal strip coil 200 and covers an axial end face 201 of the metal strip coil 200, and is for pressing the end face covering portion 301 against the axial end face 201 of the metal strip coil 200.

[0026] The outer edge of the pressing plate 72 is chamfered on the side of the pressing surface 728 that contacts the packing paper 300. In this embodiment, as described later, it has a tapered surface 730 formed in a tapered shape. In addition, the outer edge of the outer edge of the pressing plate 72, which is the leading side in the traveling direction in which the pressing plate 72 is moved when forming a valley fold in the packing paper 300, is suitable for smoothly forming a fold up to the vicinity of the outermost periphery of the metal strip coil without damaging the packing paper 300 when forming a valley fold, and has a convex shape that is asymmetrical with respect to the traveling direction in a plan view so that there is no part that reaches the outermost periphery of the metal strip coil other than the tip 723 in the traveling direction, and all apexes including the tip 723 (in this embodiment, the tip 723, the connection part between the first inclined edge 722 and the first edge 721, and the connection part between the second inclined edge 724 and the second edge 725) are rounded.

[0027] Therefore, when forming the valley fold, one of the left and right sides of the outer edge of the leading part (the part close to the valley fold line) reaches the vicinity of the outermost periphery of the metal strip coil and protrudes to form the fold up to that position, and in order to prevent the pressing plate 72 from colliding with the winding slippage of the outermost periphery, which will be described later, when this protruding part reaches the vicinity of the outermost periphery, the other of the left and right sides of the outer edge of the leading part of the pressing plate 72 is recessed rearward in the traveling direction from the one of the left and right sides so as not to reach the outermost periphery of the metal strip coil at this point, and has an asymmetrical shape. In addition, all the apexes, including the tip 723, are rounded. Therefore, the one of the left and right sides smoothly forms the fold up to the vicinity of the outermost periphery of the metal strip coil without damaging the packing paper 300, and the recession of the other of the left and right sides prevents the pressing plate 72 from colliding with the winding slippage of the outermost periphery of the coil 200, thereby realizing good packing quality.

[0028] In this embodiment, the pressing plate 72 has a first inclined edge 722 and a second inclined edge 724 with a tip 723 therebetween. As described below, the first inclined edge 722 extends from a first edge 721 that is disposed along the valley fold line when the pressing plate 72 is moved along the valley fold line of the packing paper 300 to form a crease, and is inclined away from the valley fold line (i.e., an extension line of the first edge 721). The second inclined edge 724 connects the tip 723 to a second edge 725 that faces the first edge 721. The tip 723 is rounded.

[0029] The pressing plate 72 has a third edge 726 connected to the first edge 721 and the second edge 725 on the side opposite to the leading side in the traveling direction. The third edge 726 has a convex shape that is symmetrical in the direction opposite to the traveling direction, and is rounded at the center and both ends.

[0030] The radius of curvature R1 of the tip 723 is within a range of 2 to 15 mm. More preferably, the radius of curvature R1 of the tip 723 may be within a range of 3 to 10 mm. The angle θ between the first edge 721 and the first inclined edge 722 may be within a range of 3 to 20°. More preferably, the angle θ between the first edge 721 and the first inclined edge 722 may be within a range of 5 to 15°. The dimension L between the extension line of the first edge 721 and the tip 723 may be within a range of 5 to 20 mm. More preferably, the dimension L between the extension line of the first edge 721 and the tip 723 may be within a range of 10 to 15 mm.

[0031] The radius of curvature R2 of the central portion of the third edge 726 is within a range of 5 to 30 mm. More preferably, the radius of curvature R2 of the central portion of the third edge 726 may be within a range of 10 to 20 mm. The inclination angle α of the third edge 726 may be within a range of 110 to 170°. More preferably, the inclination angle α of the third edge 726 may be within a range of 120 to 160°.

[0032] As shown in FIG. 4B, the pressing plate 72 has a mounting surface 729 for mounting the first articulated robot 70 and a pressing surface 728 for pressing the packing paper 300. Also, as shown in FIG. 4C, the end portions of the first inclined edge portion 722, the tip portion 723, and the second inclined edge portion 724 each have a tapered surface 730 formed in a tapered shape so that the pressing surface 728 is separated from the packing paper 300. That is, the tapered surface 730 is formed so that the plate thickness of the pressing plate 72 is gradually thinner toward the end portions at the end portions of the first inclined edge portion 722, the tip portion 723, and the second inclined edge portion 724. The chamfer on the side of the pressing surface 728 that contacts the packing paper 300 may be a simple chamfer instead of forming the tapered surface 730 in this way, and in this case, the chamfer dimension may be about 2 to 5 mm. Also, the plate thickness of the pressing plate 72 may be appropriately set in consideration of the weight and strength, but is preferably about 3 to 10 mm, for example.

[0033] The pressing plate 72 has suction pads 727 for adsorbing the packing paper to the pressing surface 728. In the example of Fig. 4, the pressing plate 72 has two suction pads 727 on the side opposite to the tip end 723 in the traveling direction (the side closer to the third edge 726), but the number of suction pads 727 is not limited to two, and the positions at which they are provided are not limited to the same positions.

[0034] Fig. 5 is a diagram showing the state of the metal strip coil 200 up to coil packaging. Fig. 5A shows the state in which the metal strip coil 200 is not wrapped in packing paper. Reference numeral 201 denotes an axial end face. In this specification, "coil packaging" means packaging a metal strip coil such as a steel sheet coil in packing paper (putting the coil into a packaged metal strip coil state) in order to maintain quality in a factory or warehouse, prevent damage during transportation, etc., before the product is shipped.

[0035] Fig. 5B shows a state in which a strip-shaped packing paper is wound around the outer circumference of the metal strip coil 200. Reference numeral 301 denotes an end surface covering portion of the packing paper 300. In the state of Fig. 5B, (1) while folding the mountain folds ("pleats") of the end surface covering portion 301 along the circumferential direction of the metal strip coil 200, the mountain folds are fixed with adhesive tape each time, and the same operation is performed for the entire end surface covering portion of the packing paper 300. The edge folding device of this embodiment automatically performs the operation of (1). Then, (2) the mountain folds protruding from the inner diameter side of the metal strip coil 200 are pushed into the inside of the coil hole and fixed, resulting in a "coil packaging" state as shown in Fig. 5C.

[0036] As shown in Figure 5C, in the packed metal strip coil state, the metal strip coil is wrapped in strip-shaped packing paper (packaging material) and the leading and trailing ends are fixed. The axial end face of the metal strip coil has multiple pleats woven into it to form a "chrysanthemum fold" shape, and the "pleats" protruding from the inner diameter side of the metal strip coil are stored inside the metal strip coil hole.

[0037] Next, an edge folding operation by the edge folding device 100 of this embodiment will be described. The control unit 20 executes a predetermined operation program to control the operation of each of the first articulated robot 70 and the second articulated robot 80, thereby performing an edge folding operation on the packing paper 300.

[0038] FIG. 6 is a diagram showing the first operation of the first articulated robot 70 and the second articulated robot 80. The control unit 20 controls the first articulated robot 70 so that the folding portion of the end surface covering portion 301 of the packing paper is pressed against the axial end surface 201 of the metal strip coil by the pressing plate 72. In this case, the pressing plate 72 moves along the direction indicated by the symbol C1 in FIG. 6. In this embodiment, the pressing operation against the packing paper is performed by force control in order to prevent overloading of the first articulated robot 70 and the second articulated robot 80, damage to the packing paper, and scratches on the side surface of the metal strip coil. For example, the torque value at a predetermined joint of the robot is controlled so as not to exceed an upper limit value. The first operation allows the folding portion to be pressed against the side surface of the metal strip coil.

[0039] 7 is a diagram showing the second operation of the first articulated robot 70 and the second articulated robot 80. The control unit 20 controls the second articulated robot 80 so as to grip the end of the folded portion of the packing paper with the grippers 811, 812 (81). In this case, the folded portion is pressed against the axial end surface 201 of the metal strip coil by the pressing plate 72. The end of the packing paper is gripped by the second operation.

[0040] Fig. 8 is a diagram showing a third operation of the first articulated robot 70 and the second articulated robot 80. The control unit 20 controls the first articulated robot 70 to move the pressure plate 72 to the position of the valley fold line of the folded portion of the packing paper (moving along the direction indicated by symbol C2 in Fig. 8) and to press the packing paper against the axial end face 201 of the metal strip coil at the position of the valley fold line by the pressure plate 72 so that the first edge portion 721 of the pressure plate 72 is aligned with the valley fold line. By the third operation, the valley fold line of the packing paper can be positioned and the position of the valley fold line can be maintained.

[0041] 9 is a diagram showing a fourth operation of the first articulated robot 70 and the second articulated robot 80. The control unit 20 controls the first articulated robot 70 and the second articulated robot 80 to move the gripper 81 to a position on the opposite side of the valley fold line (moving along the direction indicated by symbol C3 in FIG. 9) while the end of the folded portion of the packing paper is gripped by the gripper 81, and fold the packing paper. In this embodiment, the folding operation is performed by grippers 811 and 812 equipped with force control and a spring mechanism to perform a paper folding operation with a constant tension regardless of the packing paper material and to prevent overloading of the robot. The fourth operation allows a mountain fold line to be formed in the folded portion as the folded portion gripped by the gripper 81 is folded.

[0042] Here, stabilization of the pleat shape will be described.

[0043] Fig. 10 is a diagram showing an example of a comparative example in which the pleats are poorly shaped. As shown in Fig. 10, the inner cylindrical surface of the coil is hollow, so the packing paper inside the coil inner diameter (closer to the center) can move freely in and out of the coil. For this reason, the pleats on the inside of the coil cannot be pressed down during the edge folding operation, and poorly shaped pleats are formed.

[0044] A method for stabilizing the pleat shape according to this embodiment will be described below. Figures 11, 12, 13, and 14 are diagrams showing an example of a procedure for stabilizing the pleat shape. First, as shown in Figure 11, the packing paper is sucked by the suction pad 727, the packing paper is pressed by the presser plate 72, and the packing paper is gripped by the gripper 81. Next, as shown in Figure 12, while the packing paper is still sucked by the suction pad 727, the gripper 81 is moved to above the valley fold line while gripping the packing paper. Next, as shown in Figure 13, the suction by the suction pad 727 is released, and the presser plate 72 is moved in the direction of the arrow along the valley fold line to a position where it does not interfere with the gripper 81. Finally, while the gripper 81 is gripping the packing paper, the gripper 81 is moved in the direction of the arrow to the mountain fold line position.

[0045] 15 is a diagram showing an example of the pleat shape formed by the presser plate 72 of this embodiment. As described above, according to this embodiment, when the folded portion gripped by the gripper 81 is folded to form a mountain fold line of the folded portion, the presser plate 72 having the suction pad 727 sucks and holds the packing paper with the suction pad 727, so that the packing paper can be prevented from moving freely in the hollow portion inside the inner diameter of the coil, and therefore a good pleat shape can be formed.

[0046] Fig. 16 is a diagram showing a fifth operation of the first articulated robot 70 and the second articulated robot 80. The control unit 20 controls the first articulated robot 70 to move the pressure plate 72 in alignment with the valley fold line of the packing paper (moving along the direction indicated by symbol C4 in Fig. 16). At this time, the fold portion gripped by the gripper 81 is held in a state slightly away from the axial end face and axially outward from the pressure plate 72. By the fifth operation, the valley fold line can be formed and the fold portion can be folded along the valley fold line.

[0047] Here, the prevention of tearing of the packaging paper will be described.

[0048] 17 and 18 are diagrams showing an example of a comparative example in which tearing of the packing paper occurs. As shown in FIG. 17, the presser plate of the comparative example is rectangular (oblong), and the four corners of the presser plate are processed to be slightly rounded. Assume that the presser plate as shown in FIG. 17 is moved in the direction of the arrow along the valley fold line. In such a case, as shown in FIG. 18, the corners of the presser plate may get caught on the packing paper, causing a tear when the valley fold line is formed.

[0049] 19 is a diagram showing an example of the formation of a valley fold line by the pressing plate 72 of this embodiment. The pressing plate 72 of this embodiment has a first inclined edge 722, which eliminates the corners of the pressing plate 72, thereby preventing the corners from getting caught on the packing paper as in the comparative example. This makes it possible to form a valley fold line without tearing the packing paper.

[0050] The angle θ between the first edge 721 and the first inclined edge 722 may be 3 to 20°. If the angle θ is less than 3°, there is a possibility that the packing paper may get caught. If the angle θ is more than 20°, there is a possibility that the packing paper may not be sufficiently pressed down until it reaches the outermost periphery of the coil 200.

[0051] The tip 723 is curved in a convex shape with a radius of curvature in the range of 2 to 15 mm. If it is less than 2 mm or more than 15 mm, it may get caught on the packing paper. The dimension between the extension line of the first edge 721 and the tip 723 may be 5 to 20 mm. If this dimension is less than 5 mm, it may get caught on the packing paper. If this dimension exceeds 20 mm, it may not be possible to sufficiently press the packing paper down to the outermost periphery of the coil 200.

[0052] Next, a method for preventing collision with wrinkles in the packaging paper will be described.

[0053] Fig. 20 is a diagram showing an example of a case where a collision occurs with wrinkles in packing paper as a comparative example. There are wrinkles of various sizes on end surface covering portion 301 of packing paper 300. As shown in Fig. 20, when the pressing surface of the pressing plate and the leading end surface in the moving direction are at a right angle, if the pressing plate is moved in the direction of the arrow while pressing the packing paper with the pressing plate, the leading end surface of the pressing plate will get caught on wrinkles or small protrusions that have occurred in the packing paper, causing the wrapping paper to tear or causing the work to stop.

[0054] 21 is a diagram showing an example of a state in which the pressing plate 72 of this embodiment is moving. When the pressing plate 72 is moved while pressing the packing paper to form valley folds and mountain folds in the edge folding operation, smooth out wrinkles, etc., the pressing plate 72 of this embodiment has a tapered surface 730 (the side of the pressing surface 728 that contacts the packing paper 300 is chamfered), so it does not get caught on wrinkles or small protrusions that have occurred in the packing paper. This prevents collisions with wrinkles, and prevents the packing paper from tearing and work from being stopped.

[0055] Next, a method for preventing collision with the miswinding of the outermost periphery of the coil (metal strip coil) 200 will be described.

[0056] Fig. 22 is a diagram showing an example of a winding deviation at the outermost periphery of coil 200. When a metal strip is wound around a coil, a winding deviation is likely to occur at the outermost periphery of the coil, and as shown in Fig. 22, a part of coil 200 may protrude outward in a convex shape from the end face of coil 200.

[0057] Fig. 23 is a diagram showing an example of a case where a rectangular pressure plate as a comparative example collides with the outermost periphery of coil 200. As shown in Fig. 23, when a rectangular pressure plate is moved along a valley fold line, the leading portion of the pressure plate on the opposite side to the valley fold line collides with the miswinding of the outermost periphery before the leading portion of the pressure plate on the valley fold line side reaches the outermost periphery. For this reason, with a rectangular pressure plate, the valley fold line cannot be formed sufficiently up to the outermost periphery of coil 200.

[0058] 24 is a diagram showing an example of preventing collision with the miswinding of the outermost periphery of the coil 200 by the pressing plate 72 of this embodiment. In the pressing plate 72 of this embodiment, the second inclined edge 724 connects the second edge 725 facing the first edge 721 and the tip 723, and the connection part 731 between the second edge 725 and the second inclined edge 724 is set to be in a position away from the outermost periphery when the pressing plate is moved along the valley fold line until the tip 723 abuts on the outermost periphery of the coil 200 to form the fold. As a result, when the pressing plate 72 is moved, even if the tip 723 of the pressing plate 72 reaches the outermost periphery of the coil 200, the connection part 731 is in a position away from the outermost periphery, so that the second inclined edge 724 does not collide with the miswinding of the outermost periphery, and the pressing plate 72 does not collide with the miswinding of the outermost periphery. This makes it possible to prevent work stoppages and to sufficiently form valley fold lines up to the outermost periphery of coil 200. The position of connection portion 731 between second edge portion 725 and second inclined edge portion 724 may be set according to the outer diameter of coil 200 to be packed. When the outer diameter of coil 200 is small, connection portion 731 needs to be recessed farther rearward in the traveling direction with respect to the position of tip portion 723. On the other hand, when the outer diameter of coil 200 is large, connection portion 731 may be recessed less rearward.

[0059] FIG. 25 is a diagram showing the sixth operation of the first articulated robot 70 and the second articulated robot 80. The control unit 20 controls the first articulated robot 70 to move (in the direction indicated by symbol C5 in FIG. 25) along the mountain fold (mountain fold line) while pressing the pressing plate 72 against the mountain fold of the folding part. At this time, while the gripper 81 is gripping the end of the folding part of the packing paper, the pressing plate 72 is once released from the axial end surface 201 of the metal strip coil, and the folding part is pressed again from above the mountain fold line of the folding part gripped by the gripper 81 against the axial end surface by the pressing plate 72, while the pressing plate 72 moves along the mountain fold line in the direction indicated by symbol C5. The sixth operation makes it possible to fold the mountain fold along the mountain fold line. In addition, the crease of the folding part can be emphasized.

[0060] Here, a method for preventing wrinkles that occur when folding the packaging paper will be described.

[0061] 26 and 27 are diagrams showing an example of the flow of wrinkles as a comparative example. In the case of the pressure plate as a comparative example shown in Fig. 26, when the pressure plate is moved, the wrinkles in the packing paper flow in a direction perpendicular (perpendicular) to the moving direction (advancement direction) of the pressure plate, so the wrinkles collide with the pressure plate. For this reason, as shown in Fig. 27, large wrinkles may occur.

[0062] Fig. 28 is a diagram showing an example of the flow of wrinkles caused by the pressing plate 72 of this embodiment. In the pressing plate 72 of this embodiment, the third edge 726 has a convex shape that is symmetrical in the direction opposite to the moving direction, and is rounded at the center and both ends. As shown in Fig. 28, when the pressing plate 72 is moved in the direction of the arrow, the angle between the direction of the wrinkle flow and the moving direction (moving direction) is smaller than 90°, so that the third edge 726 smooths out the wrinkles as the pressing plate 72 moves. This makes it possible to prevent large wrinkles from occurring and to effectively smooth out the wrinkles.

[0063] 29 is a diagram showing the seventh operation of the first articulated robot 70 and the second articulated robot 80. The control unit 20 controls the second articulated robot 80 to apply adhesive tape (tape) across the edge of the mountain fold to fix the folded-in portion. In this case, the pressing plate 72 holds down the folded mountain fold, while the application unit 713 applies adhesive tape cut to the required size. Also, by applying the adhesive tape under tension while gripping, it is possible to suppress the overall bulge of the packaging paper. The mountain fold ("pleat") can be fixed by the seventh operation.

[0064] The control unit 20 repeats a series of operations (edge ​​folding operations) from the above-mentioned first operation to the seventh operation a predetermined number of times along the circumferential direction of the metal strip coil. As a result, when the edge folding work for half the circumference of the metal strip coil is completed, the robot table 32 is rotated 180 degrees, the positional relationship between the first articulated robot 70 and the second articulated robot 80 and the metal strip coil is reversed, and the edge folding operations from the first operation to the seventh operation are performed for the remaining half circumference, thereby performing the edge folding operation over the entire circumference of the metal strip coil. Note that instead of a configuration in which the robot table 32 is rotated 180 degrees, the metal strip coil itself may be rotated by a cradle roll.

[0065] The above-disclosed embodiments should be considered as illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above-disclosed embodiments, and is intended to include all modifications and variations within the meaning and scope of the claims.

[0066] For example, the convex shape that is asymmetric with respect to the traveling direction of the outer edge does not have to be formed by having a first inclined edge portion and a second inclined edge portion, and may have an asymmetric shape that is curved as a whole, or a portion of the portion extending from the tip portion to the first edge portion and the second edge portion may have a concave shape.

[0067] (Additional Note 1) The pressure plate is attached to the end of an arm of a multi-joint robot provided in an edge folding device that folds the edge of an end covering portion, which is a part of the packaging material for packaging a metal strip coil and covers the axial end face of the metal strip coil, and is a pressure plate for pressing the end covering portion against the axial end face of the metal strip coil. The outer edge of the part that is the leading side in the traveling direction, which is the direction in which the pressure plate is moved when forming a valley fold in the packaging material, is chamfered on the side of the pressing surface that contacts the packaging material, and is suitable for smoothly forming the fold up to the vicinity of the outermost circumference of the metal strip coil without damaging the packaging material when forming the valley fold. The pressure plate has a convex shape that is asymmetrical with respect to the traveling direction in a plan view so that no part other than the tip in the traveling direction reaches the outermost circumference of the metal strip coil, and all apexes including the tip are rounded.

[0068] (Appendix 2) In appendix 1, the pressure plate has a first inclined edge and a second inclined edge with the tip portion between them, the first inclined edge extends from a first edge that is positioned along the valley fold line when the pressure plate is moved in line with the valley fold line of the packaging material to form the fold, and is inclined away from the valley fold line, the second inclined edge connects the tip portion to a second edge portion opposite the first edge, and the connection portion between the second edge portion and the second inclined edge is set to be in a position away from the outermost portion when the pressure plate is moved in line with the valley fold line until the tip portion abuts the outermost portion of the metal strip coil to form the fold.

[0069] (Appendix 3) In appendix 2, the presser plate has a third edge portion connected to the first edge portion and the second edge portion on an opposite side to the leading end in the traveling direction, The third edge portion has a convex shape that is symmetrical in the direction opposite to the traveling direction, and is rounded at the center and both ends.

[0070] (Supplementary Note 4) In any one of Supplementary Notes 1 to 3, the pressing plate has a suction pad for adsorbing the packaging material to the pressing surface.

[0071] (Additional Note 5) In the pressing plate according to any one of Additional Notes 1 to 4, the radius of curvature of the rounded tip portion is within a range of 2 to 15 mm.

[0072] (Additional Note 6) In the pressing plate according to any one of Additional Notes 1 to 5, the angle between the first edge portion and the first inclined edge portion is within a range of 3 to 20°.

[0073] (Supplementary Note 7) In the pressing plate according to any one of Supplementary Notes 1 to 6, the dimension between the extension line of the first edge portion and the apex of the tip portion is within a range of 5 to 20 mm.

[0074] (Appendix 8) The edge folding device is an edge folding device that folds the edge of an end surface covering portion, which is part of the packaging material for packaging a metal strip coil and covers the axial end surface of the metal strip coil, and is equipped with a multi-joint robot having the aforementioned pressure plate attached to the tip of its arm.

[0075] The features described in each embodiment can be combined with each other. In addition, the independent claims and the dependent claims described in the claims can be combined with each other in any and all combinations regardless of the reference form, unless mutually exclusive requirements are included. [Explanation of symbols]

[0076] 10 Relative position detection unit 20 Control section 70 First Articulated Robot 71 First end effector 72 Presser plate 721 First edge 722 First inclined edge 723 Tip 724 Second inclined edge 725 Second edge 726 Third edge 727 Suction Pad 728 Pressing surface 729 Mounting surface 730 Tapered surface 713 Attachment part 714 Roll section 80 2nd Articulated Robot 81 Second end effector (gripper) 811, 812 Gripper (Gripper) 90 Robot Club 200 Metal strip coil 201 Axial end face 300 Packing Paper 301 End covering part

Claims

1. A pressing plate is attached to the arm tip of a multi-joint robot included in an edge folding device that folds edges of an end surface covering portion, which is a part of a packaging material for packaging a metal strip coil and covers an axial end surface of the metal strip coil, and is used to press the end surface covering portion against the axial end surface of the metal strip coil, the outer edge of the leading portion in the traveling direction, which is the direction in which the pressure plate is moved when forming a valley fold in the packaging material, is chamfered on the pressing surface side that contacts the packaging material, and is suitable for smoothly forming the fold up to the vicinity of the outermost periphery of the metal strip coil without damaging the packaging material when forming the valley fold, and has a convex shape that is asymmetrical with respect to the traveling direction in a plan view, so that no portion other than the tip in the traveling direction reaches the outermost periphery of the metal strip coil, and all apexes including the tip are rounded. Presser plate.

2. The pressing plate has a first inclined edge portion and a second inclined edge portion with the tip portion therebetween, The first inclined edge portion is The crease is formed by moving the pressing plate along the valley fold line of the packaging material, the pressing plate being extended from a first edge portion that is disposed along the valley fold line and being inclined away from the valley fold line, The second inclined edge portion is a second edge portion opposed to the first edge portion and the tip portion are connected to each other; The connection portion between the second edge portion and the second inclined edge portion is set to be located away from the outermost peripheral portion when the pressing plate is moved along the valley fold line until the tip portion abuts against the outermost peripheral portion of the metal strip coil to form the fold. The pressure plate according to claim 1 .

3. a third edge portion connected to the first edge portion and the second edge portion on an opposite side to the leading end side in the traveling direction; The third edge portion has a convex shape that is symmetrical in the direction opposite to the traveling direction, and a central portion and both end portions are rounded. The pressure plate according to claim 2.

4. The pressing surface has a suction pad for adsorbing the packaging material. The pressure plate according to any one of claims 1 to 3.

5. The radius of curvature of the tip portion is within a range of 2 to 15 mm. The pressure plate according to any one of claims 1 to 3.

6. The angle between the first edge and the first inclined edge is within a range of 3 to 20 degrees. The pressure plate according to claim 2 or 3.

7. The dimension between the extension line of the first edge and the apex of the tip portion is within a range of 5 to 20 mm. The pressure plate according to claim 2 or 3.

8. A folding device for folding an edge of an end surface covering portion, which is a part of a packaging material for packaging a metal strip coil and covers an axial end surface of the metal strip coil, An edge folding device comprising a multi-joint robot having an arm tip portion provided with the pressing plate according to any one of claims 1 to 3.

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