Gripping mechanism, gripping device, and method for manufacturing boxed products

Abstract

The present invention provides a gripping mechanism, a gripping device, and a method for manufacturing boxed products that enable the rapid and efficient gripping and boxing of workpieces. [Solution] A gripping mechanism for gripping a workpiece W from the side, comprising a gripping portion 10 having a contact member that grips the workpiece W by opening and closing, and a control unit 30 that controls the operation of the gripping portion 10, wherein the contact member is a rod-shaped member extending in the horizontal direction and has a pair of first contact members 11 that contact opposing sides of the workpiece W in a first direction D1.

Description

Technical Field

[0001] The present invention relates to a gripping mechanism for gripping a workpiece and packing it into a box such as cardboard, a gripping device including the same, and a method for manufacturing a boxed product. In particular, the present invention relates to a gripping mechanism capable of packing a plurality of stacked workpieces into a box at one time, a gripping device, and a method for manufacturing a boxed product manufactured by the gripping device.

Background Art

[0002] Conventionally, a gripping device has been provided for automatically packing packaged workpieces such as frozen foods into cardboard boxes. For example, in Patent Document 1, a gripping device is disclosed in which the upper surface of a workpiece is adsorbed by a bellows-shaped pad, the workpiece is moved to the position of the box, and then the adsorption of the bellows-shaped pad is released to release the workpiece into the box, thereby automatically packing the workpiece into the box.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, the configuration involves adsorbing the top surface of the workpiece to hold it in place. Therefore, when workpieces are stacked, only the top layer of workpieces that can be adsorbed by the bellows-shaped pad can be packed, resulting in a problem of increased packing time. Furthermore, in Patent Document 1, it is assumed that the adsorbed workpieces will be moved at high speed in order to pack them in a short time. However, if the workpieces are packaged products such as frozen foods contained in trays, moving the workpieces at high speed may cause the contents to fly out of the trays and disrupt their arrangement. In addition, in Patent Document 1, it is assumed that two robots will be used to adsorb and transport the workpieces in order to pack them in a short time, but this would result in increased costs.

[0005] The object of this invention is to provide a gripping mechanism, a gripping device, and a method for manufacturing boxed products that can quickly and efficiently grip and box a workpiece. [Means for solving the problem]

[0006] The present invention is essentially based on one of the following gripping mechanisms (1) to (7). (1) A gripping mechanism for gripping a workpiece from the side, comprising: a gripping portion having a contact member that grips the workpiece by opening and closing operation; and a control unit that controls the operation of the gripping portion, wherein the contact member is a rod-shaped member extending in the horizontal direction and has a pair of first contact members that contact opposing sides of the workpiece in a first direction. (2) The gripping mechanism for packing workpieces into a box, wherein the contact member further comprises a plurality of second contact members that contact opposing sides of the workpiece in a second direction substantially perpendicular to the first direction, as described in (1). (3) The gripping mechanism according to (2) above, wherein the rod-shaped member abuts against the side surface of at least one of the stacked workpieces in the first direction when the first contact member grips the workpiece in the first direction, and the second contact member abuts against the stacked workpieces simultaneously and against the side surfaces of the stacked workpieces in the second direction when gripping the workpiece in the second direction. (4) The gripping mechanism according to (1) above, wherein the gripping portion has a first drive device that opens and closes the first contact member in the first direction, and the first drive device is installed above the first contact member. (5) The gripping mechanism according to (2) above, wherein the gripping portion has a second drive device that opens and closes the second contact member in the second direction, and the second drive device is installed above the second contact member. (6) The gripping mechanism according to (1) above, having a pressing member that is movable in the vertical direction, wherein the control unit, after packing the workpiece into a box, moves the first contact member upward while lowering the pressing member when pulling the first contact member out of the box. (7) The gripping mechanism according to (2) above, wherein the control unit, when gripping the workpiece with the gripping portion, changes the pair of second contact members that are opposite each other in the first direction from a V-shape, where the distance between the second contact members is longer towards the bottom, to an inverted V-shape, where the distance between the second contact members is shorter towards the bottom, when viewed from the second direction. Furthermore, the present invention is essentially based on the gripping device described in (8) below. (8) A gripping device comprising a gripping mechanism as described in any of (1) to (7) above, and a drive robot that moves the gripping portion between a first position for gripping the workpiece and a second position for releasing the gripped workpiece. Furthermore, the present invention is essentially a method for manufacturing the boxed product described in (9) below. (9) A method for manufacturing a boxed product using the gripping device described in (8) above, wherein the workpiece is substantially rectangular in top view, the misalignment in the first direction is corrected by gripping the stacked workpieces with the plurality of first contact members, the misalignment in the second direction is corrected by gripping the stacked workpieces with the plurality of second contact members, and the workpieces gripped by the gripping part are transported from the first position to the second position by the drive robot and boxed in a rectangular box. [Effects of the Invention]

[0007] According to the present invention, the gripping portion has a first contact member that faces in a first direction and a second contact member that faces in a second direction substantially perpendicular to the first direction. The first contact member contacts the opposing sides of the workpiece in the first direction, and the second contact member contacts the opposing sides of the workpiece in the second direction. As a result, multiple stacked workpieces can be gripped at once, allowing for quick and efficient boxing of the workpieces. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view illustrating the workpiece according to this embodiment. [Figure 2] This is a perspective view of the boxing apparatus according to this embodiment. [Figure 3] This figure shows the gripping part before gripping the workpiece. [Figure 4] This diagram shows the gripping part in a state where it is gripping a workpiece. [Figure 5] This diagram illustrates the state in which the first contact member is in contact with the workpiece. [Figure 6] This diagram illustrates the action of the gripping part in gripping the workpiece. [Figure 7] This is a diagram illustrating the operation of the pressing mechanism during boxing. [Figure 8] This is a flowchart showing the boxing process according to this embodiment. [Figure 9]This is a diagram illustrating the operation of the gripping part according to another embodiment. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the figures. The present invention relates to a gripping mechanism and gripping device for gripping workpieces, and more specifically, to a gripping mechanism and gripping device for gripping multiple stacked workpieces at once. In the following description, a packing device that grips and packs workpieces W will be used as an example of a gripping device according to the present invention.

[0010] Furthermore, in this embodiment, as shown in Figure 1, a packaged product in which frozen food is placed on a tray that is roughly rectangular in shape when viewed from above, such as frozen dumplings or frozen shumai, will be used as an example workpiece for explanation. Here, Figure 1 is a cross-sectional view showing the workpiece W according to this embodiment. As shown in Figure 1, in the workpiece W according to this embodiment, the frozen food 101 is contained in the tray 102. The tray 102 has a peripheral edge portion 103 that widens outward. The packaging 104 packages the frozen food 101 together with the tray 102, and is heat-sealed in one direction (left and right direction in Figure 1), so has joint portions 105 at both ends (both left and right ends in Figure 1).

[0011] The present invention also relates to a method for manufacturing boxed products, in which such workpieces W are packed into boxes, using a gripping mechanism or gripping device according to the present invention. In this embodiment, the workpieces W are transported by a belt conveyor or the like before being packed into boxes by the boxing device according to this embodiment, and placed in a stacked state at the boxing start position (hereinafter also referred to as the first position P1). The gripping mechanism or boxing device according to this embodiment is characterized by gripping multiple workpieces W in a stacked state at once and automatically packing them into boxes such as cardboard boxes.

[0012] Figure 2 is a configuration diagram of the boxing device 1 according to the present embodiment. As shown in Figure 2, the boxing device 1 according to the present embodiment includes a gripping part 10, a robot arm part 20, and a control part 30. In the present embodiment, as the gripping device according to the present invention, the boxing device 1 having the gripping part 10, the robot arm part 20, and the control part 30 is exemplified, and as the gripping mechanism according to the present invention, a mechanism including the gripping part 10 and the control part 30 is exemplified. Further, in the present embodiment, as shown in Figure 2, the control part 30 is configured to be built in the robot arm part 20, but the present invention is not limited to this configuration, and an external computer or the like functioning as the control part 30 may be connected to the robot arm part 20 to give instructions to the robot arm part 20.

[0013] The gripping part 10 grips the workpiece W by sandwiching it from the side surface direction of the workpiece W. Here, Figure 3 is a diagram showing the gripping part 10 before gripping the workpiece W, and Figure 4 is a diagram showing the gripping part 10 in a state of gripping the workpiece W. The gripping part 10 has four first abutting members 11 and four second abutting members 12. Note that Figure 3(A) is a perspective view showing the gripping part 10 before gripping the workpiece, Figure 3(B) is a side view showing the gripping part 10 before gripping the workpiece, and Figure 3(C) is a front view showing the gripping part 10 before gripping the workpiece. Also, Figure 4(A) is a perspective view showing the gripping part 10 in a state of gripping the workpiece, Figure 4(B) is a side view showing the gripping part 10 in a state of gripping the workpiece, and Figure 4(C) is a front view showing the gripping part 10 in a state of gripping the workpiece.

[0014] As shown in FIGS. 3(A) to 3(C) and FIGS. 4(A) to 4(C), the first contact member 11 is a member having a columnar rod-shaped portion. The rod-shaped portion extends in the second direction D2 and the horizontal direction. In the present embodiment, when the gripping portion 10 grips the workpiece W, of the four first contact members 11, a pair of first contact members 11 corresponding in the first direction D1 move toward the workpiece W in the first direction D1, respectively. Thus, the pair of first contact members 11 in the first direction D1 contact the side surfaces of the workpiece W in the first direction D1, respectively, and the workpiece W can be clamped. In particular, in the present embodiment, since the columnar rod-shaped portion of the first contact member 11 extends in the second direction D2 and the horizontal direction, the portion of the rod-shaped portion that contacts the workpiece W has a round shape, and it is possible to prevent damage to the packaging of the workpiece W. The rod-shaped portion of the first contact member 11 may be a triangular prism, a quadrangular prism, or a polygonal prism instead of a columnar shape. However, as described above, in order to prevent damage to the packaging of the workpiece W when contacting, it is preferable that the portion contacting the workpiece W is at least a curved surface.

[0015] Furthermore, as shown in FIGS. 3(A) to 3(C) and FIGS. 4(A) to 4(C), the first contact member 11 extends from the lower part of the second contact member 12 in the second direction D2. Thereby, when the pair of first contact members 11 clamp the workpiece W, as shown in FIG. 5(A), it is possible to contact and clamp the side surface of the lowermost workpiece W among the plurality of stacked workpieces W. Specifically, as shown in FIG. 5(A), in a state where the workpieces W are stacked, as shown in FIG. 5(B), the first contact member 11 contacts the lower part of the side surface of the lowermost workpiece W, thereby clamping the lowermost workpiece W. Then, in this state, by moving the gripping portion 10 upward, as shown in FIG. 5(C), it is possible to lift the stacked workpieces W at once. FIG. 5 is a diagram showing a state where the first contact member 11 contacts the workpiece W. (A) shows a plurality of stacked workpieces W, (B) shows a state before lifting the workpiece W, and (C) shows a state where the workpiece W is being lifted.

[0016] As shown in Figures 4(A) to (C), the second contact member 12 has a member that extends in a substantially vertical direction D3 (the direction in which the workpieces W are stacked) when gripping the workpiece W. Specifically, the second contact member 12 has a first main surface 12a that contacts the side surface of the workpiece W in the second direction D2, and a second main surface 12b that contacts the side surface of the workpiece W in the first direction D1. As shown in Figures 4(A) to (C), the first main surface 12a and the second main surface 12b have a height equal to or greater than the height of the stacked workpieces W in the vertical direction D3, and can contact the sides of the stacked workpieces W. As a result, when the gripping part 10 lifts and moves the stacked workpieces, the first main surface 12a and the second main surface 12b can fix the position of the uppermost workpiece W in the first direction D1 and the second direction D2, and effectively prevent the workpiece W from falling in the first direction D1 or the second direction D2.

[0017] Furthermore, in this embodiment, the joint portion 105 of the workpiece W can be folded so as to press it against the side surface of the workpiece W using the first main surface 12a or the second main surface 12b of the second contact member 12, enabling smooth boxing. That is, as shown in Figure 1, when the workpiece W has a joint portion 105, during boxing, this joint portion 105 may get caught on the edge of the box opening or the like, hindering the boxing of the workpiece W or damaging the packaging 104. However, in this embodiment, as shown in Figures 4(A) to (C) and Figures 5(B) and (C), when the workpiece W is gripped by the gripping portion 10, the second main surface 12b of the second contact member 12 comes into contact with the joint portion 105 of the workpiece W, and the joint portion 105 of the workpiece W can be folded so as to press it against the side surface of the workpiece W. As a result, when packing the workpiece W into a box, it is possible to prevent the joint portion 105 of the workpiece W from getting caught on the edge of the box opening, and the workpiece W can be packed into the box smoothly without damaging the packaging 104.

[0018] Furthermore, in this embodiment, when viewed from the second direction D2, the second contact member 12 is tilted in a V-shape before gripping the workpiece W, as shown in Figure 3(B), and when gripping the workpiece W, it becomes an inverted V-shape, with the lower part narrower than the upper part, as shown in Figure 4(B). In this way, when the second contact member 12 grips the workpiece W, it changes from the V-shape tilted state shown in Figure 3(B) to the inverted V-shape tilted state shown in Figures 4(A) to (C). This allows the second main surface 12b facing the first direction D1 to come into contact with the side surface of the workpiece W in the first direction, even if the stacked workpieces W are misaligned in the first direction D1, or if the bottom layer of workpiece W is placed misaligned in the first direction D1 from the first position P1 which is the boxing start position. The misalignment of the workpiece W in the first direction D1 can be corrected by the second contact member 12 (second main surface 12b). Furthermore, the first contact member 11 is connected to the lower part of the second contact member 12, and as shown in Figure 4(B), by tilting the second contact member 12 in an inverted V shape when viewed from the second direction D2, the first contact member 11 can more securely grip the workpiece W at the bottom.

[0019] Furthermore, in this embodiment, the second contact member 12 is also movable in the second direction D2, and after moving the pair of second contact members 12 facing the first direction D1 to the first direction D1, the pair of second contact members 12 corresponding to the second direction D2 can be moved to the second direction D2. As a result, even if the stacked workpieces W are stacked with a misalignment in the second direction D2, or if the bottom layer of workpiece W is placed at a position shifted in the second direction D2 from the first position P1, which is the boxing start position, the first main surface 12a facing the second direction D2 and the side surface of the workpiece W in the second direction D2 can come into contact, and the misalignment of the workpiece W in the second direction D2 can be corrected.

[0020] As shown in Figure 3, the gripping section 10 has a first actuator 13 and a second actuator 14. The first actuator 13 and the second actuator 14 operate based on the control of the control unit 30 and open and close the gripping section 10 by driving the first contact member 11 and the second contact member. Specifically, the first actuator 13 drives a pair of opposing first contact members 11 and a pair of opposing second contact members 12 (second main surface 12b) toward the workpiece W in the first direction D1, and drives a pair of opposing first contact members 11 and a pair of opposing second contact members 12 (second main surface 12b) toward the workpiece W in the first direction D1, thereby causing the gripping section 10 to open and close in the first direction D1.

[0021] More specifically, in this embodiment, the first actuator 13 has a rotation mechanism that rotates the second contact member 12 in the direction D4 or the opposite direction of D4, as shown in Figure 3(B). By moving the pair of second contact members 12 facing each other in the first direction D1 in the direction D4 using this rotation mechanism, the arrangement can be changed from a V-shape where the distance between the second contact members 12 is longer towards the bottom, as shown in Figure 3(B), to an inverted V-shape where the distance between the second contact members 12 is shorter towards the bottom, as shown in Figure 4(B), when viewed from the second direction D2. As a result, the first actuator 13 can bring the first contact member 11 into contact with the side surface of the workpiece W, and grip the workpiece W with the first contact member 11, as will be explained below. Furthermore, in this embodiment, the rotation center of the second contact member 12 is set above the center of the second contact member 12. As a result, when the second contact member 12 is rotated, even with a small amount of drive from the first actuator 13, the first contact member 11 connected to the lower part of the second contact member 12 can be moved significantly in the D4 direction.

[0022] In this embodiment, when the gripping portion 10 is not gripping the workpiece W, the control unit 30 positions the second contact member 12 in a V-shape when viewed from the second direction D2, as shown in Figures 3(A) and (B), and the distance between the pair of first contact members 11 facing each other in the first direction D1 with the workpiece W in between is increased. Then, when the gripping portion 10 grips the workpiece W, the control unit 30 controls the operation of the first actuator 13 to rotate the pair of second contact members 12, which are tilted in a V-shape, in the D4 direction, so that they form an inverted V-shape, as shown in Figure 4(B). As a result, as shown in Figure 4(B), the distance between the pair of first contact members 11 facing each other in the first direction D1 with the workpiece W in between is reduced, and the first contact members 11 facing each other in the first direction D1 can grip the workpiece W in the first direction D1. Furthermore, by moving the pair of second contact members 12, which are inclined in a V-shape, in the D4 direction, the second main surfaces 12b of the pair of second contact members 12 that are opposite each other in the first direction D1 simultaneously come into contact with the side surfaces of the stacked workpieces W in the second direction D2, and the stacked workpieces W can be gripped (or supported) by the second main surfaces 12b.

[0023] The operation of the first contact member 11 described above will be explained with reference to Figure 6. Figure 6 is a diagram illustrating the operation of the gripping part 10 in gripping the workpiece W, and shows the first contact member 11 and the second contact member 12 of the gripping part 10 in a top view. As shown in Figure 6(A), in this embodiment, when the gripping part 10 grips the workpiece W, first, the first actuator 13 is operated to move the second contact member 12 in the D4 direction, so that the pair of first contact members 11 that are facing each other in the first direction D1 with the workpiece W in between, which are connected to the second contact member 12, move toward the workpiece W in the first direction D1, and as a result, as shown in Figure 6(B), the distance between the pair of first contact members 11 that are facing each other in the first direction D1 is shortened, and the workpiece W can be gripped in the first direction D1. Furthermore, as shown in Figure 5(A), the first contact member 11 fits under the periphery of the bottommost workpiece W, thereby enabling the stacked workpieces W to be lifted all at once when the gripping part 10 is moved upward. Also, by moving the second contact member 12 in the D4 direction, the second main surfaces 12b (especially the lower part of the second main surfaces 12b) of the pair of second contact members 12 facing each other in the second direction D2 also move toward the workpiece W in the first direction D1. As a result, as shown in Figure 6(B), the second main surfaces 12b of the pair of second contact members 12 facing each other in the first direction D1 come into contact with the workpiece W in the first direction D1, correcting the displacement of the workpiece W in the first direction D1 and fixing the workpiece W in the first direction D1.

[0024] The second actuator 14 causes the gripping portion 10 to perform an opening and closing operation in the second direction D2 by driving a pair of opposing second contact members 12 toward the workpiece W in the second direction D2, and by driving a pair of opposing second contact members 12 toward the workpiece W in the second direction D2. In this embodiment, as shown in Figures 6(A) and (B), the first actuator 13 drives the first contact member 11 and the second contact member 12, which are opposite each other in the first direction D1, in the first direction D1, thereby gripping the workpiece W between the second main surfaces 12b of the first contact member 11 and the second contact member 12 in the first direction D1. Then, as shown in Figures 6(B) and (C), the second actuator 14 moves the pair of second contact members 12, which are opposite each other in the second direction D2, toward the workpiece W in the second direction D2, thereby bringing the first main surfaces 12a of the second contact members 12, which are opposite each other in the second direction D2, into contact with the side surfaces of the workpiece W in the second direction D2, and thus gripping the workpiece W from the second direction D2 as well.

[0025] In this embodiment, as described above, the first contact member 11 and the second contact member 12 move in the first direction D1 and the second direction D2. Therefore, as shown in Figure 6(A), even if the stacks of workpieces W are separated in the second direction D2 and offset in the first direction D1, the gripping part 10 can simultaneously grip two stacks of workpieces W. Specifically, as shown in Figure 6(B), by moving the pair of first contact members 11 and second contact members 12, which are opposite to each other in the first direction D1, toward the workpieces W in the first direction D1, the offset of the stacks of workpieces W in the first direction D1 can be corrected. Also, as shown in Figure 6(C), by moving the pair of second contact members 12, which are opposite to each other in the second direction D2, toward the workpieces W in the second direction D2, the gap between the two stacks of workpieces W in the second direction D2 can be eliminated. Then, in the state shown in Figure 6(C), the gripping part 10 is moved upward, and the two piles of workpieces W are lifted simultaneously, allowing the two piles of workpieces W to be transported at the same time.

[0026] Furthermore, the gripping portion 10 has a pressing portion 15, as shown in Figures 3(B) and 4(B). The pressing portion 15 can move vertically. Specifically, as shown in Figures 3 and 4, the gripping portion 10 has a third actuator 16 for moving the pressing portion 15 vertically, and by driving the third actuator 16, the pressing portion 15 can be moved up and down with a constant force.

[0027] In this embodiment, the control unit 30 controls the drive of the third actuator 16, changing the relative height position of the pressing portion 15 within the gripping portion 10. Specifically, before gripping the workpiece W, as shown in Figure 3(B), the third actuator 16 moves the pressing portion 15 to an upper height position PH1, close to the first actuator 13. Then, in this state, the control unit 30 causes the gripping portion 10 to grip the workpiece W. In this embodiment, when the gripping portion 10 grips the workpiece W, the height position PH1 becomes higher than the uppermost layer of the workpiece W, and the pressing portion 15 does not press against the workpiece W. As a result, the first contact member 11 and the second contact member 12 can correct the misalignment of the workpiece W in the first direction D1 and the second direction D2 without being obstructed by the pressing portion 15.

[0028] Figure 7 is a diagram illustrating the operation of the pressing part 15 during boxing. After the workpieces W are packed into the box, the control unit 30 first moves the pressing part 15 to a height position PH2 within the gripping part 10 that is relatively lower than the height position PH1. This allows the pressing part 15 to press down on the top surface of the top layer of stacked workpieces W, as shown in Figure 7(A). Next, as shown in Figure 7(B), the control unit 30 causes the gripping part 10 to move upward in order to pull out the first contact member 11 and the second contact member 12 from the box. At this time, the pressing part 15 remains in a state of pressing down on the top surface of the top layer of workpieces W. Specifically, as shown in Figure 7(B), if the pressing part 15 is not operated when the gripping part 10 is moved upward, the pressing part 15 will move upward along with the upward movement of the gripping part 10, and will no longer be able to continue to press down on the top surface of the top layer of stacked workpieces W. Therefore, in this embodiment, the control unit 30 instructs the third actuator 16 to move the pressing portion 15 below the height position PH2 in accordance with the speed at which the gripping portion 10 is moved upward (the relative height position within the gripping portion 10 is changed over time to a height position PH3, which is lower than the height position PH2). This allows the pressing portion 15 to continue pressing down on the top surface of the uppermost stacked workpiece W when the first contact member 11 and the second contact member 12 are lifted out of the box after the workpiece W has been packed into the box, effectively preventing the first contact member 11 and the second contact member 12 from getting caught on the workpiece W and causing the workpiece W to fall out of the box. After the first contact member 11 and the second contact member 12 have been lifted out of the box, the control unit 30 instructs the third actuator 16 to move the pressing portion 15 to the upper height position PH1. This allows the workpiece W to be gripped and moved again.

[0029] Furthermore, when the workpiece W is placed in the box, the control unit 30 keeps the second contact member 12 in an inverted V-shape when viewed from the second direction D2, as shown in Figure 5(C). When the second contact member 12 is withdrawn from the box, as shown in Figures 7(A) and (B), the second contact member 12 is straightened vertically when viewed from the second direction D2 before being withdrawn from the box. This effectively prevents the second contact member 12 from hitting the edge of the box opening when the workpiece W is placed in the box, allowing the workpiece W to be packed smoothly. It also prevents the second contact member 12 from hitting the workpiece W and causing the workpiece W to fly out of the box when it is withdrawn from the box. However, when pulling the second contact member 12 out of the box, even if the second contact member 12 is straight in the vertical direction when viewed from the second direction D2, the second contact member 12 may still cause the workpiece W to lift up. In this embodiment, however, the pressing part 15 presses down on the workpiece W from above, which firmly prevents the workpiece W from flying out of the box.

[0030] Next, the robot arm 20 will be described. The robot arm 20 is a drive robot that can move the position of the gripping unit 10 by being connected to the gripping unit 10, for example, a SCARA robot or a drive unit that combines actuators for the three axes of X, Y, and Z. Specifically, the robot arm 20 can repeatedly move the gripping unit 10 back and forth between a first position P1 in which gripping of a workpiece is started and a second position P2 in which the gripped workpiece is released and the workpiece is packed into a box. In this embodiment, the robot arm 20 also has an arm actuator 21 that moves in the vertical direction, as shown in Figure 2. The arm actuator 21 has a rod 211 that connects to the gripping unit 10 and a motor 212, and the gripping unit 10 can be raised and lowered by moving the rod 211 in the vertical direction with the motor 212. In this embodiment, the operation of the robot arm 20 is controlled by the control unit 30. At the first position P1, the gripping unit 10 grips a plurality of stacked workpieces W, and then moves the gripped workpieces W to the second position P2.

[0031] The control unit 30 controls the operation of the gripping unit 10 and the robot arm unit 20. Here, Figure 8 is a flowchart of the boxing process according to this embodiment. The boxing process based on the control of the control unit 30 according to this embodiment will be described below with reference to Figure 8.

[0032] In step S101, the control unit 30 operates the first actuator 13, tilting the second contact member 12 so that it forms a V-shape when viewed from the second direction D2. This causes the gripping portion 10 to open in the first direction D1. Also in step S101, the control unit 30 operates the second actuator 14, driving the pair of opposing second contact members 12 in the second direction D2 away from the workpiece W, thereby causing the gripping portion 10 to open in the second direction D2.

[0033] In step S102, the control unit 30 moves the gripping unit 10 to the first position P1 on which the workpiece W is placed. Specifically, the control unit 30 controls the movement of the robot arm 20 and moves the gripping unit 10 to the first position P1 using the robot arm 20.

[0034] In step S103, the control unit 30 moves the gripping unit 10 downward to a height where it can grip the workpiece W. Specifically, the control unit 30 moves the gripping unit 10 downward by driving the arm actuator 21 of the robot arm unit 20, bringing it to a height where it can grip the workpiece W. It is preferable to provide a sensor to detect the transport of the workpiece W, and to configure the control unit 30 to automatically execute the steps from step S103 onwards when the sensor detects the transport of the workpiece W. In other words, the control unit 30 completes the processing up to step S102 and waits until the workpiece W is transported to the first position P1, and then executes the processing from step S103 onwards when the workpiece W is transported to the first position P1.

[0035] In step S104, the control unit 30 moves the pair of first contact members 11, which are facing each other in the first direction D1, toward the workpiece W in the first direction D1. Specifically, the control unit 30 drives the first actuator 13 to move the second contact member 12 in the D4 direction so that, when viewed from the second direction D2 side, it changes from a V-shape as shown in Figure 3(B) to an inverted V-shape as shown in Figure 4(B), thereby changing the inclination of the second contact member 12. As a result, the first contact member 11 moves toward the workpiece W in the first direction D1, as shown in Figure 6(A), and comes into contact with the side surface of the workpiece W in the first direction D1, as shown in Figure 6(B). In this embodiment, since the first contact member 11 is installed below the second contact member 12, when it comes into contact with the workpiece W, it comes into contact with the side surface of the bottommost workpiece W among the stacked workpieces W, as shown in Figure 5(A).

[0036] Furthermore, in this embodiment, the first contact member 11 is connected to the second contact member 12, and as the pair of first contact members 11 facing the first direction D1 move in the first direction D1, the pair of second contact members 12 facing the first direction D1 also move in the first direction D1. As a result, as shown in Figures 4(A) to (C), the second main surface 12b of the second contact member 12 simultaneously contacts multiple stacked workpieces W, and as shown in Figure 6(B), the displacement of the workpieces W in the first direction D1 can also be corrected.

[0037] In step S105, the control unit 30 moves the second contact member 12 in the second direction D2. Specifically, the control unit 30 drives the second actuator 14 to move the pair of opposing second contact members 12 in the second direction D2 horizontally in the second direction D2. As a result, the second contact members 12 move from the state shown in Figure 6(B) to the state shown in Figure 6(C), so that the opposing first main surfaces 12a in the second direction D2 come into contact with the sides of the workpiece W in the second direction D2. This corrects the misalignment of the workpiece W in the second direction D2, and even when two stacks of workpiece W are separated, as shown in Figure 6(A), it becomes possible to combine the two stacks of workpiece W into one and grip them simultaneously, as shown in Figure 6(C).

[0038] In step S106, the control unit 30 moves the gripping unit 10 upward. In this case, as shown in Figures 5(B) and (C), the gripping unit 10 lifts the bottommost workpiece W with the first contact member 11, thereby simultaneously lifting other workpieces W stacked on top of the bottommost workpiece W. Furthermore, the gripping unit 10 holds the lifted workpiece W in the first direction D1 and the second direction D2 with the second contact member 12, effectively preventing the workpiece W from falling.

[0039] In step S107, the control unit 30 moves the gripping unit 10 from the first position P1 to the second position P2. Specifically, the control unit 30 instructs the robot arm 20 to operate the robot arm 20, which is connected to the gripping unit 10, so that the gripping unit 10 moves horizontally from the first position P1 to the second position P2. In order to shorten the time it takes to move the workpiece W from the first position P1 to the second position P2, the control unit 30 can also control the operation of the gripping unit 10 so that as soon as the gripping unit 10 lifts the workpiece W at the first position P1, it moves horizontally while moving upward (in other words, it moves diagonally upward toward the second position P2).

[0040] Then, in step S108, the control unit 30 moves the gripping unit 10 downward to the second position P2. Specifically, the control unit 30 operates the arm actuator 21 to lower the gripping unit 10 toward the inside of the box. As a result, the workpiece W can be packed into the box, as shown in Figure 7(A).

[0041] In step S109, the control unit 30 lowers the pressing unit 15. Specifically, the control unit 30 drives the third actuator 16 to move the pressing unit 15 downward. As a result, as shown in Figure 7(A), the pressing unit 15 presses down on the uppermost workpiece W of the stacked workpieces W.

[0042] Then, in step S110, the control unit 30 performs an operation to pull out the first contact member 11 and the second contact member 12 from the box while the upper surface of the workpiece W is being pressed down by the pressing part 15 that was lowered in step S109. Specifically, the control unit 30 operates the arm actuator 21 of the robot arm 20 to move the gripping part 10 upward. At this time, the pressing part 15 of the gripping part 10 also moves upward, so the control unit 30 drives the third actuator 16 while moving the gripping part 10 upward, moving only the pressing part 15 downward. This makes it possible to pull out the first contact member 11 and the second contact member 12 from the box while the workpiece W is being pressed down with a constant pressure by the pressing part 15. Then, in step S111, since the first contact member 11 and the second contact member 12 have been pulled out from the box, the control unit 30 performs an operation to move the pressing part 15 upward.

[0043] In step S112, the control unit 30 determines whether or not to terminate the boxing process. For example, the boxing apparatus 1 according to this embodiment has an input unit (not shown), through which the user can instruct the start / end of the boxing process. If the control unit 30 is instructed to terminate the boxing process, it determines in step S112 to terminate the boxing process (step S112 = Yes) and terminates the boxing process shown in Figure 8. On the other hand, if the control unit 30 is not instructed to terminate the boxing process, it returns to step S101 and repeats the process from steps S101 to S111. If the number of times the boxing process is to be executed is fixed, the control unit 30 may be given a function to register the number of executions and automatically terminate the boxing process when the registered number of executions are completed.

[0044] As described above, the box packing device 1 according to this embodiment has a gripping mechanism for gripping and packing a plurality of stacked workpieces W by their sides. The gripping mechanism includes a gripping section 10 having a contact member that grips the workpieces W by opening and closing, and a control unit 30 that controls the operation of the gripping section 10. The contact member is a rod-shaped member extending in the horizontal direction and has a pair of first contact members 11 that contact opposing sides of the workpieces W in a first direction D1. As a result, the box packing device 1 having the gripping mechanism according to this embodiment can grip the side of the workpieces W on which the tray 102 is located and lift the workpieces W. Therefore, compared to, for example, the case where the workpieces W are lifted by adsorption to the upper surface of the workpieces W on which the tray 102 is not located, it is possible to effectively prevent deformation of the contents of the workpieces W. Furthermore, in this embodiment, the joint portion 105 of the workpiece W can be folded so that it is pressed against the side surface of the workpiece W by the first main surface 12a or the second main surface 12b of the second contact member 12. This effectively prevents the joint portion 105 of the workpiece W from getting caught on the edge of the box opening when packing the workpiece W into a box, and allows the workpiece W to be packed into a box smoothly without damaging the packaging 104.

[0045] Furthermore, in the box packing device 1 according to this embodiment, when packing the workpiece W into a box, by keeping the second contact member 12 in an inverted V shape when viewed from the second direction D2, it is possible to more effectively prevent the second contact member 12 from hitting the periphery of the box entrance, and the workpiece W can be packed more smoothly. Moreover, in this embodiment, when pulling out the second contact member 12 from the box, as shown in Figures 7(A) and (B), by straightening the second contact member 12 vertically when viewed from the second direction D2 before pulling out the second contact member 12 from the box, it is possible to suppress the second contact member 12 from hitting the workpiece W and causing the workpiece W to fly out of the box.

[0046] Furthermore, the box packing device 1 according to this embodiment includes a gripping unit 10 having contact members that grip the workpiece W through an opening and closing operation, and a control unit 30 that controls the operation of the gripping unit 10. The contact members include a plurality of first contact members 11 that clamp opposing sides of the workpiece in a first direction D1, and a plurality of second contact members 12 that contact opposing sides of the workpiece W in a second direction D2 which is substantially perpendicular to the first direction D1. By gripping the workpiece W in the first direction D1 with the first contact members 11 and contacting the workpiece W in the second direction D2 with the second contact members 12, a plurality of stacked workpieces W can be lifted at once and packed into boxes. As a result, the box packing device 1 according to this embodiment can pack workpieces W efficiently and stably into boxes. Furthermore, while conventional methods (such as those described in Patent Document 1) could only pack one or two workpieces W into a box using a single robot arm 20, the box packing apparatus 1 according to this embodiment, as shown in Figure 1, can pack three or more workpieces W (10 workpieces W in this embodiment) into a box at once using a single robot arm 20.

[0047] Furthermore, in the box packing apparatus 1 according to this embodiment, the first actuator 13 that operates the first contact member 11 and the second actuator 14 that operates the second contact member 12 are installed above the first contact member 11 and the second contact member 12. Generally, it is preferable to install actuators near the object to be operated, and normally, it is preferable to install the first actuator 13 that moves the first contact member 11 horizontally on the side of the first contact member 11, and the second actuator 14 that moves the second contact member 12 horizontally on the side of the second contact member 12. However, when the first actuator 13 is installed on the side of the first contact member 11 and the second actuator 14 is installed on the side of the second contact member 12, the first contact member 11 and the second contact member 12 may get in the way when packing the workpiece W into a box, such as hitting the periphery of the box opening, making it impossible to pack the workpiece W into the box. In contrast, in this embodiment, since the first actuator 13 and the second actuator 14 are installed above the first contact member 11 and the second contact member 12, it is possible to effectively prevent the first contact member 11 and the second contact member 12 from getting in the way and preventing the workpiece W from being packed into the box.

[0048] On the other hand, as described above, if the first actuator 13 and the second actuator 14 are installed above the first contact member 11 and the second contact member 12, the distance between the first actuator 13 and the first contact member 11 increases, making it difficult to transmit the force required to bring the first contact member 11 into contact with the side surface of the workpiece W. In particular, in this embodiment, the first contact member 11 is connected to the lower part of the second contact member 12, and the structure is such that the first actuator 13 moves the second contact member 12, thereby moving the first contact member 11 which is connected to the second contact member 12. Therefore, when attempting to apply force to the first contact member 11 to properly contact the side surface of the workpiece W, excessive force may be transmitted to the second contact member 12, potentially causing damage to the workpiece W. However, in this embodiment, when gripping the workpiece W, the pair of second contact members 12 facing each other in the first direction D1 are changed from a V-shape where the distance between the second contact members 12 is longer towards the bottom, to an inverted V-shape where the distance between the second contact members 12 is shorter towards the bottom, when viewed from the second direction D2. This allows the workpiece W to be brought into contact with the first contact member 11 with an appropriate force without applying excessive force to the second contact member 12.

[0049] Although preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the embodiments described above. Various modifications and improvements can be made to the above embodiments, and such modified or improved forms are also included in the technical scope of the present invention.

[0050] For example, in the embodiment described above, a configuration in which a robot arm 20 is provided as a device for moving the position of the gripping unit 10 of the box packing device 1 was illustrated. However, the configuration is not limited to this, and for example, the gripping unit 10 can be connected to a slider to move a stack of workpieces W gripped by the gripping unit 10 to the box packing position. By connecting it to a six-axis robot, the stack of workpieces W can be tilted and the workpieces can be packed into a box placed at an angle. In other words, the gripping mechanism having the gripping unit 10 and the control unit 30 can be applied to various transport-type drive robots for moving the gripping unit 10, thereby providing a box packing device 1 suited to the application.

[0051] Furthermore, in the above-described embodiment, as shown in Figure 6 in a top view, the gripping portion 10 has four first contact members 11 and four second contact members 12, and each first contact member 11 and each second contact member 12 is connected to each other. However, the configuration is not limited to this, and for example, as shown in Figure 9, it can have a configuration with first contact members 11 and second contact members 12. Figure 9 is a diagram illustrating the gripping operation of the gripping portion 10 according to another embodiment.

[0052] In other words, as shown in Figure 9(A), the gripping portion 10 can be configured to have two first contact members 11 and four second contact members 12. In this case, since the second contact members 12 are connected to both ends of the first contact member 11, the second contact members 12 cannot be moved in the second direction D2. However, by moving the first contact member 11 in the first direction D1 to grip the workpiece W from the first direction D1, the second contact members 12 can prevent the workpiece W from falling in the second direction, thus allowing multiple stacked workpieces W to be gripped at once.

[0053] Furthermore, in the example shown in Figure 9(B), the gripping portion 10 has two first contact members 11 and two second contact members 12, and the first contact members 11 and the second contact members 12 are not connected to each other. In this case, similar to the example shown in Figure 6, the first contact member 11 can be moved in the first direction D1 to grip the workpiece W in the first direction D1, and the second contact member 12 can be moved in the second direction D2 to grip the workpiece W from the second direction as well, allowing multiple stacked workpieces W to be gripped at once. In the example shown in Figure 9(B), in order to prevent the multiple stacked workpieces W from falling in the first direction D1, it is desirable that the first contact member 11 be configured to have a portion with a height corresponding to the height of the multiple stacked workpieces W.

[0054] Furthermore, in the example shown in Figure 9(C), the gripping portion 10 has a configuration that includes two first contact members 11 and six second contact members 12. In the example shown in Figure 9(C), the workpiece W can be gripped from the second direction as well by moving the second contact members 12 in the second direction D2. However, since the second contact members 12 are connected to both ends of the first contact members 11, it is preferable to first move the second contact members 12 in the second direction D2 to grip the workpiece W from the second direction D2, and then move the first contact members 11 in the first direction D1 to grip the workpiece W from the first direction D1.

[0055] In addition, in the example shown in Figure 9(D), similar to the configuration shown in Figure 9(B), the gripping portion 10 has two first contact members 11 and two second contact members 12, but the first contact members 11 and the second contact members 12 are connected to each other. By moving the connected first contact members 11 and second contact members 12 in an oblique direction (for example, the D5 direction shown in Figure 9), the gripping portion 10 can grip the workpiece W from a first direction D1 and also from a second direction D2.

[0056] Furthermore, in the above-described embodiment, when the second contact member 12 grips the workpiece W, as shown in Figure 4(B), it is exemplified as having an inverted V-shape where the lower part is narrower than the upper part when viewed from the second direction D2. However, the configuration is not limited to this, and for example, it can be configured to be approximately perpendicular to the horizontal plane (extending in the vertical direction D3).

[0057] Furthermore, in the embodiment described above, the first contact member 11 is shown as being installed at the bottom of the second contact member 12 so as to contact the side surface of the bottommost workpiece W among the stacked workpieces W. However, the configuration is not limited to this, and the first contact member 11 can also be installed on any part of the second contact member 12 so as to contact the side surface of any one of the stacked workpieces W (for example, so as to contact the side surface of the third workpiece W from the top of a stack of five workpieces W).

[0058] In addition, in the embodiments described above, a boxing device for boxing workpieces W was used as an example of a gripping device having the gripping mechanism according to the present invention. However, the gripping device according to the present invention is not limited to boxing devices and can also be applied to, for example, a transport device that grips a workpiece W at a predetermined first position P1, moves it to a second position P2, and then releases it at the second position P2. [Explanation of Symbols]

[0059] 1... Packing machine 10...Gripping part 11…First contact member 12...Second contact member 12a...First main surface 12b...Second main surface 13…First actuator 14…Second actuator 15...Pressing part 16…Third actuator 20…Robot arm section (driven robot) 21... Arm actuator 211... Rod 212...motor 30…Control Unit W...work 101...Frozen food 102...Tray 103... Peripheral area 104...Packaging 105…Joint part

Claims

1. A gripping mechanism that grips a workpiece from the side, A gripping portion having a contact member that grips the workpiece through an opening and closing operation, It includes a control unit that controls the operation of the gripping part, The gripping mechanism comprises a pair of first contact members, each a rod-shaped member extending horizontally, which contact opposing sides of the workpiece in a first direction.

2. The gripping mechanism according to claim 1, wherein the contact member further comprises a plurality of second contact members that contact opposing sides of the workpiece in a second direction substantially perpendicular to the first direction.

3. The rod-shaped member abuts against the opposing side surfaces in the first direction of at least one of the stacked workpieces when the first contact member grips the workpiece in the first direction. The gripping mechanism according to claim 2, wherein the second contact member simultaneously contacts the stacked workpieces when gripping the workpiece in the second direction, and also contacts the opposing side surfaces of the stacked workpieces in the second direction.

4. The gripping portion has a first drive device that opens and closes the first contact member in a first direction. The gripping mechanism according to claim 1, wherein the first drive device is installed above the first contact member.

5. The gripping portion has a second drive device that opens and closes the second contact member in the second direction. The gripping mechanism according to claim 2, wherein the second drive device is installed above the second contact member.

6. It further includes a pressing member that can move in the vertical direction, The gripping mechanism according to claim 1, wherein the control unit, after packing the workpiece into a box, lowers the pressing portion while moving the first contact member upward when pulling the first contact member out of the box.

7. The gripping mechanism according to claim 2, wherein the control unit, when gripping the workpiece with the gripping portion, changes the pair of second contact members that are opposite each other in the first direction from a V-shape, where the distance between the second contact members is longer towards the bottom, to an inverted V-shape, where the distance between the second contact members is shorter towards the bottom, when viewed from the second direction.

8. A gripping mechanism according to any one of claims 1 to 7, A gripping device comprising a drive robot that moves the gripping portion between a first position for gripping the workpiece and a second position for releasing the gripped workpiece.

9. A method for manufacturing a boxed product using the gripping device described in claim 8, The aforementioned workpiece is roughly rectangular when viewed from above. The stacked workpieces are clamped between the plurality of first contact members to correct the misalignment in the first direction. A method for manufacturing boxed products, comprising transporting the workpiece gripped by the gripping part by the drive robot from a first position to a second position and packing it into a rectangular box.

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