Laminating system and laminating method

Abstract

A stacking system (10) for stacking a plurality of workpieces (30) to a predetermined placement location, the plurality of workpieces (30) being placed in acquisition locations separated from each other, the stacking system (10) being provided with: a robot arm (20) to which a robot hand (40) for gripping the workpieces is attached at the tip; and a control device (50) that controls the operation of the robot arm. The manipulator is configured so as to be capable of simultaneously gripping all of the workpieces in a state in which a plurality of workpieces are stacked in multiple layers. The control device executes: a gripping process in which the tip of the robot arm is moved to the vicinity of an acquisition location and each of a plurality of workpieces is gripped one by one by a robot hand (40); and a placement process in which, after all of the plurality of workpieces are gripped by the robot hand by repeatedly executing the gripping process, the tip of the robot arm is moved to the vicinity of the placement location, and all of the plurality of workpieces are placed in the placement location while being stacked in multiple layers.

Description

Technical Field

[0001] Embodiments of the present invention relate to a lamination system and a lamination method using a robot arm. Background Art

[0002] In a production line of a product, there is a process of stacking a plurality of workpieces in a plate shape that are dispersedly placed in separate places to a predetermined arrangement place. Stacking means stacking in multiple layers in the longitudinal direction. Patent document 1 discloses a stacking device for performing such stacking. The stacking device disclosed in patent document 1 is a complex structure fixed at a position for stacking. In the past, a system for stacking using a robot arm has been studied for the purpose of increasing the freedom of movement and simplifying the structure.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-081741 Summary of the invention

[0006] Technical Problems to be Solved by the Invention

[0007] Usually, when a robot arm is used for stacking, the following action flow is adopted. First, the top end of the robot arm is moved to the vicinity of the acquisition location where the workpiece is placed, and the workpiece is grasped by a manipulator installed on the top end of the robot arm. Then, the top end of the robot arm is moved to the vicinity of the configuration location, and the workpiece is temporarily placed at the configuration location. By performing these grasping and temporary placement actions on all the workpieces, multiple workpieces are stacked at the configuration location. In this stacking based on the usual action flow, since the workpieces are temporarily placed one by one at the configuration location for stacking, the movement distance of the robot arm becomes longer, and as a result, the cycle time for stacking may be prolonged.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lamination system and a lamination method capable of shortening the cycle time related to lamination.

[0009] Technical solutions for solving technical problems

[0010] The stacking system of the embodiment is a system that uses a robot arm to stack a plurality of workpieces placed at mutually separated acquisition locations at a predetermined configuration location. The stacking system comprises: the robot arm having a manipulator for gripping the workpiece mounted at the top; and a control device that controls the movement of the robot arm. The manipulator is configured to grip all of the plurality of workpieces at the same time in a state where the plurality of workpieces are overlapped into multiple layers. The control device performs: a gripping process in which the top of the robot arm is moved to the vicinity of the acquisition location and the manipulator grips each of the plurality of workpieces one by one; and a configuration process in which, after the manipulator grips all of the plurality of workpieces by repeatedly performing the gripping process, the top of the robot arm is moved to the vicinity of the configuration location and the plurality of workpieces are maintained in a state where they are overlapped into multiple layers and are placed at the configuration location. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The diagram schematically shows the configuration of a stacking system according to one embodiment, and is a diagram showing a state in which a plurality of workpieces are located at different acquisition locations.

[0012] Figure 2 The diagram schematically shows the configuration of a stacking system according to one embodiment, and is a diagram showing a state in which a plurality of workpieces are stacked in an arrangement location.

[0013] Figure 3 It is a diagram showing a specific first configuration example of a manipulator according to an embodiment.

[0014] Figure 4 It is a diagram showing a specific second configuration example of the manipulator according to one embodiment.

[0015] Figure 5 It is a diagram showing a specific third configuration example of the manipulator according to one embodiment.

[0016] Figure 6 It is a diagram showing a specific fourth configuration example of the manipulator according to one embodiment.

[0017] Figure 7 A fourth specific configuration example of the robot according to one embodiment is shown, which is a diagram showing a state in which the placing unit is tilted upward.

[0018] Figure 8 A fifth specific configuration example of the robot hand according to one embodiment is shown, which is a diagram showing a state where a workpiece is not gripped.

[0019] Fig. 9 A fifth specific configuration example of the robot hand according to one embodiment is shown, which is a diagram showing a state of gripping one workpiece.

[0020] Fig.10This is a diagram showing an example of the content of the first process executed by the control device according to one embodiment.

[0021] Fig.11 This is a diagram for explaining a flow of a series of operations when the first process is executed by a control device according to one embodiment.

[0022] Fig.12 This is a diagram showing an example of the content of the second process executed by the control device according to one embodiment.

[0023] Fig.13 This is a diagram for explaining the flow of a series of operations when the second process is executed by the control device according to one embodiment.

[0024] Fig.14 This is a diagram showing an example of the content of the third process executed by the control device according to one embodiment.

[0025] Fig.15 This is a diagram for explaining a flow of a series of operations when the third process is executed by the control device according to one embodiment.

[0026] Figure 1 6 is a diagram for explaining the moving distance of the arm tip during lamination in the comparative example (conventional technology).

[0027] Figure 1 7 is a diagram for explaining the moving distance of the arm tip during stacking according to one embodiment.

[0028] Fig.18 It is a diagram for explaining the operation when the robot hand of the second configuration example according to one embodiment is used and grasps the second and subsequent workpieces.

[0029] Fig.19 It is a diagram for explaining the operation when the robot hand of the first structural example of one embodiment is used and grasps the second and subsequent workpieces.

[0030] Fig. 20 It is a perspective view showing the structure of a modified example of the robot hand according to one embodiment, and is a view showing a state in which a workpiece is not gripped.

[0031] Fig.21 It is a perspective view showing the structure of a modified example of the robot hand according to one embodiment, and is a view showing a state of gripping a workpiece.

[0032] Fig. 22 The diagrams show a state in which a plurality of stacked workpieces are slightly offset from each other and a state in which the plurality of stacked workpieces are aligned according to one embodiment.

[0033] Description of Reference Numerals

[0034] 10: Cascading system

[0035] 20: Robotic Arm

[0036] 30, 30a, 30b, 30c: Workpiece

[0037] 31, 32: Main side

[0038] 33: Side

[0039] 40, 40A, 40B, 40C, 40D, 40E, 40F: Robot

[0040] 41A, 41B, 41C, 41D, 41E, 42A, 42B, 42C, 42D: claw

[0041] 43A, 43B, 43C, 43D, 43E, 44A, 44B, 44C, 44D, 44E, 45E: Loading section

[0042] 46, 47, 48, 49: Support part

[0043] 50: Control device DETAILED DESCRIPTION

[0044] Hereinafter, a stacking system according to an embodiment will be described with reference to the accompanying drawings. Figure 1 as well as Figure 2 As shown, the stacking system 10 is a system that stacks a plurality of workpieces 30a, 30b, and 30c using a robot arm 20. Specifically, the stacking system 10 uses the robot arm 20 to stack the workpieces 30a, 30b, and 30c. Figure 1 As shown in FIG. 1 , a plurality of workpieces 30a to 30c are dispersedly placed, that is, a plurality of workpieces 30a to 30c are placed in separate acquisition locations. Figure 2 The system is stacked to a predetermined configuration location as shown. The acquisition location and the configuration location are set at any location such as a pedestal or container with a plane. Stacking means stacking in multiple layers in a direction perpendicular to the plane of the configuration location. In addition, in the following description, when there is no need to distinguish between workpieces 30a to 30c, they are collectively referred to as workpieces 30.

[0045] In the present embodiment, the case of stacking three workpieces 30a to 30c is illustrated, but the number of workpieces 30 to be stacked is not limited to three, and may be two or more than four. However, the number of workpieces to be stacked is not limited to the number that the robot arm 20 can grasp. The robot arm 20 is configured as a horizontal multi-jointed robot with a four-axis arm, for example. The workpiece 30 is, for example, a food and has a so-called flat shape. Specifically, the workpiece 30 is in the shape of a flat plate having two main surfaces 31 and 32 facing each other. The workpieces 30a to 30c in the shape of a flat plate are, for example, smaller boxes for storing items such as candy. In the present specification, one of the two directions orthogonal to each other along the main surfaces 31 and 32 of the workpiece 30 is referred to as the left-right direction RL, and the direction orthogonal to the main surfaces 31 and 32 is referred to as the up-down direction UD.

[0046] A robot arm 40 for gripping the workpiece 30 is mounted at the top end of the robot arm 20. The robot arm 40 is configured to grip all of the workpieces 30 stacked in multiple layers at the same time. Figure 1 as well as Figure 2 , a structural example of the robot 40 having such a structure is shown, but the structure of the robot 40 is not limited to this, and various structures including various structures as will be described later can be adopted.

[0047] The movement of the robot arm 20 including the manipulator 40 is controlled by the control device 50. The control device 50 is a control unit including a computer CP having a CPU 50A, a ROM 50B, and a RAM 50C. In the control device 50, the CPU 50A calls a computer program for controlling the robot pre-stored in the ROM 50B or an external memory functioning as a program storage medium in its work area and executes it, thereby controlling the movement of the robot arm 20. The control device 50 is constructed with functional blocks such as a gripping processing unit 51 and a configuration processing unit 52 according to relevant control functions. That is, the gripping processing unit 51 and the configuration processing unit 52 are functionally implemented by software. In addition, it can also be configured so that at least a part of each functional block is implemented by hardware.

[0048] The gripping processing unit 51 (i.e., the CPU 50A) performs a gripping process for moving the arm tip 21, which is the tip of the robot arm 20, to the vicinity of the acquisition location and for gripping each of the plurality of workpieces 30 one by one by the manipulator 40. The vicinity of the acquisition location refers to a range from a position directly above or obliquely above the workpiece 30 to be acquired, to a minimum position that can ensure preparations such as opening and closing of the manipulator for gripping during the period when the arm tip 21 is moved from the position to the workpiece 30, which also depends on the moving speed.

[0049] The placement processing unit 52 (i.e., the CPU 50A) performs placement processing, which moves the arm tip 21 to the vicinity of the placement location and places all the multiple workpieces 30 in a stacked state at the placement location after the robot 40 has grasped all the multiple workpieces 30 by repeatedly performing the grasping processing by the grasping processing unit 51. The vicinity of the placement location refers to a position directly above or obliquely above the location where the stacked workpieces are to be placed, and is the shortest position sufficient for the stacked workpieces to land safely.

[0050] <Specific structural example of the robot>

[0051] As a specific structure of the manipulator 40 attached to the arm tip 21 of the robot arm 20 , the five structure examples described below and the like can be adopted.

[0052] [1] First Configuration Example

[0053] like Figure 3 As shown, the robot 40A of the first structural example has two claws 41A and 42A that move in parallel in the left-right direction to open and close. The top ends of the two claws 41A and 42A are provided with a loading portion (or loading sheet) 43A and 44A that extends along the left-right direction RL. The loading portion 43A is formed from a Figure 3 The base end of the left end is as Figure 3 The top end of the right end in the middle has a uniform thickness in the up-down direction UD. Figure 3 The base end of the right end of the Figure 3 The thickness of the top end of the left side of the mounting portion 43A and the mounting portion 44A is uniform.

[0054] [2] Second Configuration Example

[0055] like Figure 4 As shown, the robot 40B of the second structural example has two claws 41B and 42B that move parallel to each other in the left-right direction RL to open and close. The top ends of the two claws 41B and 42B are provided with carriers 43B and 44B that extend along the left-right direction RL. The carrier 43B is formed from Figure 4 The base end of the left end is as Figure 3 The thickness of the top end portion of the right end portion of the middle part gradually decreases, that is, the shape of the top end portion is inclined downward from the base end portion to the top end portion. Figure 4 The base end of the right end of the Figure 4 The thickness of the top end of the left end of the mounting portion 43B and 44B gradually decreases, that is, the shape of the bottom end tilting downward from the base end to the top end. In addition, the thickness of the base end of the mounting portion 43B and 44B is roughly the same as the thickness of the workpiece 30 or greater than the thickness of the workpiece 30.

[0056] [3] Third structural example

[0057] like Figure 5 As shown, the robot 40C of the third structural example has two claws 41C and 42C that move in parallel in the left-right direction RL to open and close. The top ends of the two claws 41C and 42C are provided with carriers 43C and 44C that extend along the left-right direction RL. The carrier 43C is formed from a Figure 5 The base end of the left end is as Figure 5 The top end of the right end in the middle has a uniform thickness in the up-down direction UD. Figure 5 The base end of the right end of the Figure 5 The thickness of the top end of the left end portion of the mounting portion 43C and 44C is uniform. In addition, the thickness of the mounting portion 43C and 44C is substantially the same as the thickness of the workpiece 30 or is greater than the thickness of the workpiece 30.

[0058] [4] Fourth structural example

[0059] like Figure 6 As shown, the robot 40D of the fourth structural example has two claws 41D and 42D that move parallel to each other in the left-right direction RL to open and close. The top ends of the two claws 41D and 42D are provided with carriers 43D and 44D that extend along the left-right direction RL. The carrier 43D is formed from a Figure 6 The base end of the left end is as Figure 6 The top end of the right end in the middle has a uniform thickness in the vertical direction UD. Figure 6 The base end of the right end of the Figure 6 The thickness of the top end of the left side of the mounting portion 43D and 44D is uniform. In addition, the thickness of the mounting portion 43D and 44D is smaller than the thickness of the workpiece 30.

[0060] like Figure 7 As shown in FIG. 1 , the loading portion 43D is configured such that its top end can be rotated upwards by means of a built-in rotation mechanism RT with its base end as the center. Although not shown in the figure, the loading portion 44D is also configured such that its top end can be rotated upwards with its base end as the center, similarly to the loading portion 43D. In other words, the loading portions 43D and 44D are configured such that their top ends can only be tilted upwards ( Figure 7 , refer to arrow).

[0061] [5] Fifth structural example

[0062] like Figure 8 as well as Fig. 9As shown, the robot 40E of the fifth structural example has a claw portion 41E. Three carrier portions 43E, 44E, and 45E extending along the left-right direction RL are provided at the top of the claw portion 41E in an overlapping manner along the up-down direction UD. The number of carrier portions is not limited to three, as long as the number is greater than the number of workpieces 30 to be stacked. The carrier portions 43E to 45E are configured to be able to move independently along the up-down direction UD through the built-in upper and lower mechanism portions EL. In addition, the carrier portions 43E to 45E are configured to be able to move independently or uniformly along the left-right direction RL toward the outside of the robot 40E. In other words, the carrier portions 43E to 45E are configured to be able to be pulled out from the robot 40E.

[0063] <Specific Examples of Grasping Processing and Arrangement Processing>

[0064] As specific contents of the extraction process and the placement process executed by the control device 50 (ie, the computer CP (ie, the CPU 50A)), the following contents can be adopted. Figure 10 to Figure 15 An example of specific processing contents corresponding to the first to fifth configuration examples of the robot 40 will be described.

[0065] [1] Contents of the first processing corresponding to the first to third configuration examples

[0066] When the robot 40 is the robot 40A of the first structural example, the robot 40B of the second structural example, or the robot 40C of the third structural example, the control device 50 can execute the following operations: Fig.10 The first process is a process for realizing a method of adding a workpiece 30 grasped by the robot 40 by opening and closing the robot 40. In this case, steps S102, S103, S104, and S105 are processes corresponding to the grasping process, and steps S107, S108, and S109 are processes corresponding to the placement process.

[0067] In step S101, any one of the three workpieces 30 that has not been gripped by the robot 40 is set as a gripping target workpiece, i.e., a target workpiece. In step S102, a process of moving the robot 40 to a position above the target workpiece, i.e., a position above the target workpiece, is executed. In step S103, a process of opening the two claws 41A, 42A, etc., i.e., opening the robot 40, is executed along the left-right direction RL. Steps S102 and S103 can be executed in reverse order or simultaneously.

[0068] In step S104, the robot 40 is moved downward, that is, the robot 40 is lowered toward the target workpiece. In step S105, the two claws 41A, 42A, etc. are closed along the left-right direction RL, that is, the target workpiece is loaded on the loading portion 43A, 44A, etc. by closing the robot 40. In step S106, it is determined whether all three workpieces 30 are gripped by the robot 40. Here, if all three workpieces 30 are not gripped by the robot 40, the result is "No" in step S106, and the process returns to step S101. On the other hand, if all three workpieces 30 are gripped by the robot 40, the result is "Yes" in step S106, and the process proceeds to step S107.

[0069] In step S107, the robot 40 is moved to a position above the placement location. In step S108, the robot 40 is moved downward, that is, the robot 40 is lowered toward the placement location to reach the placement location. In step S109, the two claws 41A, 42A are opened along the left-right direction RL, that is, the robot 40 is opened to place the target workpiece at the placement location. After step S109 is executed, this process ends.

[0070] In the case where the first processing is performed by the control device 50, Fig.11 The series of actions shown in the figure are used to stack the workpieces 30. Fig.11 In the example, the robot 40A of the first structure example is used as the robot 40, but the robot 40B of the second structure example or the robot 40C of the third structure example is used as the robot 40 to stack the workpieces 30 through the same series of actions. Fig.11 As shown in the first layer, the action of grasping the first workpiece 30a is performed. As the action of grasping the workpiece 30, from Fig.11 From the left side, the following are “(1) Move the robot 40A to above the target workpiece” → “(2) Open the robot 40A” → “(3) Lower the robot 40A toward the target workpiece” → “(4) Load the target workpiece on the loading parts 43A, 44A by closing the robot 40A”.

[0071] Next, if Fig.11 As shown in the second layer of FIG. 3 , the second workpiece 30 b is grasped. Fig.11As shown in the third layer of the robot, the third workpiece 30c is grasped, and finally, the three workpieces 30 are placed in the arrangement place. Although not shown in the figure, the action of placing the three workpieces 30 in the arrangement place is as follows: "Move the robot 40A to a position above the arrangement place" → "Descend the robot 40A toward the arrangement place" → "Open the robot 40A". As a result, the three workpieces 30 are arranged in the arrangement place in a stacked state.

[0072] [2] Contents of the second process corresponding to the fourth configuration example

[0073] When the robot 40D of the fourth configuration example is used as the robot 40, the control device 50 can execute the following operations: Fig.12 The second process is a process for realizing a method of adding a workpiece 30 grasped by the robot 40D by utilizing the structure that the top ends of the placement parts 43D and 44D are tilted only in the upward direction. Fig.10 The first process shown is different in that steps S103 and S105 are omitted. In this case, steps S102 and S104 are processes corresponding to the grasping process, and steps S107, S108, and S109 are processes corresponding to the placement process.

[0074] In the second process, step S104 is executed after step S102 is executed. In this case, by executing step S104, when the top of the robot 40D descends to the plane reaching the acquisition location, the target workpiece is tilted upward into the inner side of the robot 40D by the placement parts 43D and 44D at the top of the robot 40D. After that, the placement parts 43D and 44D at the top of the robot 40D return to the original state and the target workpiece is loaded on the placement parts 43D and 44D. In this case, step S104 is equivalent to the process of loading the target workpiece on the placement parts 43D and 44D by moving the robot 40D downward.

[0075] When the robot 40D of the fourth configuration example is used as the robot 40 and the second process is executed by the control device 50, Fig.13 The series of actions shown in the figure are used to stack the workpiece 30. First, Figure 1 As shown in the first layer of FIG. 3, the first workpiece 30a is grasped. As the workpiece 30 is grasped, Figure 1 3, the following are in order: "(1) Move the robot 40D to above the target workpiece" → "(2) Lower the robot 40D toward the target workpiece and place the target workpiece inside the robot 40D" → "(3) Return the loading parts 43D and 44D to their original state and load the target workpiece on the loading parts 43D and 44D".

[0076] Next, if Fig.13 As shown in the second layer of FIG. 3 , the second workpiece 30 b is grasped. Fig.13 As shown in the third layer of the figure, the action of grasping the third workpiece 30c is performed, and finally, the action of placing the three workpieces 30 in the arrangement place is performed. As the action of placing the workpiece 30 in the arrangement place, although it is omitted in the figure, it is "moving the robot 40D to a position above the arrangement place" → "lowering the robot 40D toward the arrangement place" → "opening the robot 40D". As a result, the three workpieces 30 are arranged in the arrangement place in a stacked state.

[0077] [3] Contents of the third processing corresponding to the fifth configuration example

[0078] When the robot 40E of the fifth configuration example is used as the robot 40, the control device 50 can execute the following operations: Fig.14 The third process is a process for realizing a method of adding the workpiece 30 gripped by the robot 40E by placing the workpiece on the placement sections 43E to 45E and raising the placement sections 43E to 45E.

[0079] The third treatment is relative to Fig.10 The first process shown is different in that step S103 is omitted, steps S201 and S202 are provided instead of step S105, step S203 is provided instead of step S109, etc. In this case, steps S102, S104, S201, and S202 are processes corresponding to the grasping process, and steps S107, S108, and S203 are processes corresponding to the configuring process.

[0080] After step S104, step S201 is executed. In step S201, by executing the process of moving the robot 40E to the right direction as the direction to the target workpiece in the left-right direction RL, the placement section 43E etc. enters the lower side of the target workpiece, that is, the target workpiece is loaded on the placement section 43E etc. In this case, steps S104 and S201 are equivalent to the process of loading the target workpiece on any of the placement sections 43E to 45E by moving the robot 40E downward and in the left-right direction RL.

[0081] In the next step S202, a process is executed to move any of the loading parts 43E to 45E loaded with the target workpiece upward, that is, to raise any of the loading parts 43E to 45E loaded with the target workpiece. After the execution of step S202, step S106 is executed. After step S108, step S203 is executed. In step S203, a process for placing the target workpiece at the arrangement location, specifically, a process for tilting the robot 40E with respect to the up-down direction UD, or a process for pulling the loading parts 43E to 45E out of the robot 40E by moving them in the left-right direction RL is executed. After the execution of step S203, this process ends.

[0082] When the robot 40E of the fifth configuration example is used as the robot 40 and the third process is executed by the control device 50, Fig.15 The series of actions shown in the figure are used to stack the workpiece 30. First, Figure 1 5, the first workpiece 30a is grasped. As the workpiece 30 is grasped, Figure 1 5, in order, “(1) Move the robot 40E to above the target workpiece” → “(2) Lower the robot 40E toward the target workpiece” → “(3) Move the robot 40E to the right and move any of the loading sections 43E to 45E under the target workpiece” → “Raise any of the loading sections 43E to 45E loaded with the target workpiece”.

[0083] Next, if Fig.15 As shown in the second layer of FIG. 3 , the second workpiece 30 b is grasped. Fig.15 As shown in the third layer of the figure, the action of grasping the third workpiece 30c is performed, and finally, the action of placing the three workpieces 30 in the configuration place is performed. As the action of placing the workpiece 30 in the configuration place, although part of the figure is omitted, it is "moving the robot 40E to a position above the configuration place" → "lowering the robot 40E toward the configuration place" → "(X) tilting the robot 40E" or "(Y) pulling out the loading parts 43E~45E". As a result, the three workpieces 30 are arranged in the configuration place in a stacked state.

[0084] According to the present embodiment described above, the following effects can be obtained.

[0085] The stacking system 10 of the present embodiment is a system that uses a robot arm 20 to stack a plurality of workpieces 30 placed at mutually separated acquisition locations at a predetermined configuration location. The stacking system 10 comprises: a robot arm 20 having a manipulator 40 mounted at the top end for gripping the workpiece 20; and a control device 50 that controls the movement of the robot arm 20. The manipulator 40 is configured to grip all of the plurality of workpieces 30 at the same time in a state where the plurality of workpieces 30 are stacked in multiple layers. The control device 50 performs: a gripping process in which the top end of the robot arm 20 is moved to the vicinity of the acquisition location and the manipulator 40 grips each of the plurality of workpieces 30 one by one; and a configuration process in which the top end of the robot arm 20 is moved to the vicinity of the configuration location and the plurality of workpieces 30 are maintained in a state where all of the plurality of workpieces 30 are stacked in multiple layers and are placed in a temporary configuration location (temporary configuration location).

[0086] Thus, compared with the stacking of the usual operation flow of temporarily placing the workpieces 30 one by one, the moving distance of the arm tip 21 of the robot arm 20 is suppressed to be short, so the cycle time related to the stacking can be greatly shortened. Fig.16 as well as Fig.17 , the effects obtained by this embodiment are described in detail. In addition, in the following, there is a case where the stacking of the usual action flow of temporarily placing the workpieces 30 one by one is referred to as the stacking based on the comparative example (conventional technology). Fig.16 as well as Fig.17 In FIG. 1 , the initial position of the arm tip 21 of the robot arm 20 is indicated by a white circle P, and the rough movement trajectory of the arm tip 21 is indicated by an arrow.

[0087] In the stacking based on the comparative example (prior art), as Figure 1 6, the arm tip 21 of the robot arm 20 moves in the order of "initial position P" → "acquisition location P1 of the first workpiece 30a" → "temporary placement location PP" → "acquisition location P2 of the second workpiece 30b" → "temporary placement location PP" → "placement location P3 of the third workpiece 30c" → "temporary placement location PP". In contrast, in the stacking of the present embodiment, as shown in FIG. Fig.17 As shown, the arm tip 21 of the robot arm 20 moves in the order of "initial position P" → "acquisition location P1 for the first workpiece 30a" → "acquisition location P2 for the second workpiece 30b" → "acquisition location P3 for the third workpiece 30c" → "temporary placement location PP". The acquisition location is, for example, a location on the conveyor BC where the gap S2 or S1 is adjacent to each other when the workpiece 30 is conveyed by the belt conveyor BC (at this time, the conveyor BC may be temporarily stopped or may be operated at a low speed).

[0088] In addition, whether in the comparative example or in the embodiment, the multiple workpieces 30 (30a, 30b, 30c) temporarily stacked in the temporary configuration place PP can be placed as is and handled later, such as when transporting to other places, or can be packed in a box HK as shown in the figure (boxing).

[0089] In the latter case, the temporary placement place PP may be the interior of the box HK, and the plurality of workpieces 30 sequentially taken away and held by the robot may be stored in the box HK as they are.

[0090] like Figure 1 6 and Fig.17 As shown, according to the stacking of the present embodiment, the moving distance of the arm tip 21 of the robot arm 20 is suppressed to be shorter than that of the stacking based on the comparative example. Specifically, according to the stacking of the present embodiment, the moving distance of the arm tip 21 is suppressed to be shorter mainly by a distance corresponding to the moving distance for returning from the configuration location to the acquisition location, compared with the stacking based on the comparative example, and as a result, the cycle time can be shortened by the time related to such movement.

[0091] If any of the first to third structural examples is used as the manipulator 40 and the first processing is performed through the control device 50, the manipulator 40 only needs to be configured to be able to perform opening and closing actions, so its structure only needs to be simple. A relatively cheap manipulator can be used as the manipulator 40, thereby achieving the effect of reducing costs.

[0092] If the fourth configuration example is adopted as the robot 40 and the second process is executed by the control device 50, the robot 40 does not need to open or close when gripping the workpiece 30, so the cycle time for stacking can be further shortened.

[0093] Compared with the case where the robot 40B of the second structure example or the robot 40C of the third structure example is used as the robot 40, the case where the robot 40A of the first structure example or the robot 40D of the fourth structure example is used as the robot 40 has the following advantages. Figure 1 As shown in FIG8 , the thickness of the placing parts 43B and 44B of the robot 40B is substantially the same as or greater than the thickness of the workpiece 30. Although not shown in the figure, the robot 40C is the same as the robot 40B.

[0094] In contrast, Fig.19 As shown in FIG. 1 , the thickness of the placing parts 43A and 44A of the robot 40A is smaller than the thickness of the workpiece 30. Although not shown in the figure, the same is true for the robot 40D as for the robot 40A. Thus, the thickness of the placing parts 43A and 44A of the robot 40A is thinner than the thickness of the placing parts 43B and 44B of the robot 40B.

[0095] According to the manipulator 40B having relatively thick mounting portions 43B and 44B, as shown in FIG. Fig.18 As shown, when the robot 40B is opened to grasp the second or subsequent workpieces 30, the grasped workpiece 30 falls from a relatively high position and an impact is applied to the workpiece 30 because the lower main surface 32 of the workpiece 30b, which is the lowest among the held workpieces 30, is separated from the upper main surface 31 of the workpiece 30c to be grasped.

[0096] In contrast, according to the robot 40A in which the thickness of the placing parts 43A and 44A are relatively thin, Fig.19 As shown, when the robot 40A is opened to grasp the second and subsequent workpieces 30, the grasped workpiece 30 will not fall from a relatively high position and will not be impacted because the lower main surface 32 of the workpiece 30b, which is the lowest among the held workpieces 30, is close to the upper main surface 31 of the workpiece 30c to be grasped. In this way, if the robot 40A of the first structural example or the robot 40D of the fourth structural example is used as the robot 40, the grasped workpiece 30 will not fall and impact the workpiece 30 when grasping the second and subsequent workpieces 30.

[0097] <Variations of the structure of the robot>

[0098] The structure of the robot arm 40 may be modified as follows: for example, a mechanism for preventing the workpiece 30 from falling when the top end of the robot arm 20 is moved while gripping the workpiece 30, that is, when the workpiece 30 is being transported. Figure 20 to Figure 22 For explanation. Fig. 20 as well as Fig.21 As shown, the robot 40F of this modification example has four additional support parts 46, 47, 48, and 49 compared to the robot 40A of the first structural example.

[0099] The support parts 46 to 49 each include a rectangular plate-shaped component. Fig.21 As shown, the support parts 46 to 49 are provided to support two of the four side surfaces 33 of the workpiece 30, which are surfaces other than the main surface, in the state of gripping the workpiece 30. In addition, the claws 41A and 42A of the robot 40F support the remaining two of the side surfaces 33. According to the robot 40F of this modified example, the four sides of the workpiece 30 are covered by the structural components of the robot 40F including the support parts 46 to 49 in the state of gripping the workpiece 30, so that the workpiece 30 is prevented from falling during the conveyance of the workpiece 30.

[0100] In addition, according to the robot 40F of this modification, since the structure of the robot 40F is disabled, the workpiece 30 can be pressed from all sides by grasping the workpiece 30, so that the three workpieces 30 can be evenly arranged, and as a result, the three workpieces 30 can be stacked in a state of being aligned. Further, according to the robot 40F of this modification, when all the workpieces 30 are grasped, even if Fig. 22 As shown on the left side of the figure, the workpieces 30 are slightly offset from each other. In this state, when the top end of the robot arm 20 is moved to a position above the configuration site, the robot arm 20 is stopped urgently at a position above the configuration site, and the inertial force acts on the workpiece 30, so that Fig. 22 As shown on the right side of FIG. , three workpieces 30 can be stacked in a state where they are reliably aligned.

[0101] (Other Embodiments)

[0102] In addition, the present invention is not limited to the embodiments described above and in the drawings, and can be arbitrarily modified, combined, or expanded within a scope not departing from the gist of the present invention.

[0103] The numerical values ​​and the like shown in the above-mentioned embodiments are merely examples and are not limiting.

[0104] The robot arm 20 is not limited to a horizontal articulated robot, and various robot arms may be used, such as a vertical articulated robot having a six-axis or seven-axis arm.

[0105] The present disclosure is described based on the embodiments, but it can also be understood that the present disclosure is not limited to the embodiments and configurations. The present disclosure also includes various modifications and variations within the scope of equality. In addition, various combinations and methods, further including only one element and other combinations and methods above or below it on this basis, also belong to the scope and scope of thought of the present disclosure.

Claims

1. A stacking system for stacking a plurality of workpieces placed at mutually separated acquisition locations at a predetermined placement location using a robot arm, the stacking system comprising: The robot arm has a manipulator mounted on the top thereof for grasping the workpiece; and a control device for controlling the movement of the robot arm, The robot arm is configured to simultaneously grasp all of the plurality of workpieces in a state where the plurality of workpieces are overlapped in multiple layers. The control device performs: A gripping process in which the tip of the robot arm moves to the vicinity of the acquisition location and the robot hand grips each of the plurality of workpieces one by one; and Arrangement processing, after the robot grips all the multiple workpieces by repeatedly executing the gripping processing, the top end of the robot arm is moved to the vicinity of the arrangement location and all the multiple workpieces are placed in the arrangement location while being kept overlapped into multiple layers.

2. The stacking system according to claim 1, wherein: The workpiece is in the shape of a flat plate having two main surfaces facing each other, Let one of the two directions perpendicular to each other along the main surface be the left-right direction, and the direction perpendicular to the main surface be the up-down direction, The robot arm has two claws that move in parallel in the left-right direction to open and close. A placing portion extending in the left-right direction is provided at the top ends of the two claws. During the grasping process, the control device executes: A process of moving the robot hand to a position above the workpiece to be grasped, that is, the target workpiece; The process of opening the two claws in the left-right direction and moving the robot arm downward; as well as A process of placing the target workpiece on the placement portion by closing the two claws in the left-right direction.

3. The stacking system according to claim 1, wherein: The workpiece is in the shape of a flat plate having two main surfaces facing each other, Let one of the two directions perpendicular to each other along the main surface be the left-right direction, and the direction perpendicular to the main surface be the up-down direction, The robot arm has two claws that move in parallel in the left-right direction to open and close. A placing portion extending in the left-right direction is provided at the top ends of the two claws. The placing portion is configured such that its top end portion can rotate upward with its base end portion as the center. During the grasping process, the control device executes: A process of moving the robot hand to a position above the workpiece to be grasped, that is, the target workpiece; as well as A process of placing the target workpiece on the placement unit by moving the robot downward.

4. The stacking system according to claim 2, wherein: A dimension of the mounting portion in a vertical direction is smaller than a dimension of the workpiece in the vertical direction.

5. The stacking system according to claim 1, wherein: The workpiece is in the shape of a flat plate having two main surfaces facing each other, Let one of the two directions perpendicular to each other along the main surface be the left-right direction, and the direction perpendicular to the main surface be the up-down direction, The robot arm has a claw. A plurality of placement portions extending in the left-right direction are provided at the top end of the claw portion in a manner overlapping in the up-down direction. The plurality of loading portions are configured to be movable in the vertical direction and the horizontal direction. During the grasping process, the control device executes: A process of moving the robot hand to a position above the workpiece to be grasped, that is, the target workpiece; A process of loading the target workpiece on the mounting portion by moving the robot arm downward and in the left-right direction; as well as The loading portion on which the target workpiece is loaded moves upward, The arrangement process includes performing a process of tilting the robot arm with respect to a vertical direction or a process of pulling the plurality of placement portions out from the robot arm by moving the plurality of placement portions in a horizontal direction.

6. The stacking system according to any one of claims 2 to 5, wherein: The robot arm includes a support portion that supports a side surface of the workpiece other than the main surface while gripping the workpiece.

7. A stacking method, using a robot arm to stack a plurality of workpieces placed at separate acquisition locations at a predetermined placement location, wherein: The robot arm is provided with a manipulator for grasping the workpiece at its top end. The robot arm is configured to simultaneously grasp all of the plurality of workpieces in a state where the plurality of workpieces are overlapped in multiple layers. The stacking method performs: A gripping process in which the tip of the robot arm moves to the vicinity of the acquisition location and the robot hand grips each of the plurality of workpieces one by one; and Arrangement processing, after the robot grips all the multiple workpieces by repeatedly executing the gripping processing, the top end of the robot arm is moved to the vicinity of the arrangement location and all the multiple workpieces are placed in the arrangement location while being kept overlapped into multiple layers.

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