Film cutting device, film adsorption unit used therein, and film recovery method

Abstract

To provide a film cutting device that prevents the film from easily falling off the suction pad after cutting. [Solution] The film cutting device comprises a measuring unit, a cutter unit, a film suction unit moving mechanism, and a film suction unit 30. The film suction unit 30 comprises a suction pad 31, a case 32, a pressing member 33, and a pressing member drive unit 34. The pressing portion 33c of the pressing member 33 is movable between an original position located on the same side as the suction pad 31 with respect to the film, and an operating position in which the film, while being suctioned by the suction pad 31, is separated from the article, allowing it to enter the space formed between the film and the article through the cutting point of the film, and to cooperate with the suction pad 31 to press down on the peripheral edge of the film. The pressing member 33 is driven by the pressing member drive unit 34.

Description

Technical Field

[0001] The present invention relates to a film cutting device, a film suction unit used therein, and a film recovery method.

Background Art

[0002] As a film cutting device, for example, as described in Patent Document 1 below, there is known a device for cutting a film in a workpiece including a pallet, an article placed on the pallet, and a film that wraps around the outer periphery of the pallet and the article to fix the article to the pallet. This film cutting device includes a measurement unit that measures the horizontal position on the side surface of the workpiece corresponding to each position in the vertical direction while moving in the vertical direction, a cutter that cuts the film, and a cutter drive unit that controls the position of the cutter in the horizontal direction according to the measurement result by the measurement unit while moving the cutter in the vertical direction. According to this film cutting device, it is possible to accurately cut only the film that wraps around the outer periphery of the article and the pallet without damaging the article.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the film cutting device described in Patent Document 1 above, the cut film is adsorbed to the suction pad of the suction unit, and the drive unit of the recovery unit is controlled to send it to a predetermined recovery position. However, since the article is packaged with the film having an appropriate tension, the film instantaneously contracts from the cutting portion, and the cutting portion often opens widely. Due to this, the adsorption of the film by the suction pad becomes insufficient, and there is a risk that the film will fall off from the suction pad.

[0005] This invention has been made in view of the above circumstances, and aims to provide a film cutting device that prevents the film from easily falling off the suction pad after the film has been cut. [Means for solving the problem]

[0006] To solve the above problems, the film cutting apparatus according to the present invention is A film cutting device for cutting a film in a workpiece that includes a pallet, an article placed on the pallet, and a film that wraps around the pallet and the outer periphery of the article to fix the article to the pallet, A measuring unit that moves in the vertical direction and measures the horizontal position on the side surface of the workpiece corresponding to each position in the vertical direction, A cutter unit that moves vertically together with the measuring unit and cuts the film by moving horizontally according to the measurement results measured by the measuring unit, A film adsorption unit having an adsorption pad capable of adsorbing the aforementioned film, The film adsorption unit is supported so as to be movable in a direction in which the adsorption pad approaches or moves away from the film, and the film adsorption unit moving mechanism further moves the film adsorption unit to a predetermined recovery position so as to peel the film, which is adsorbed by the adsorption pad, from the article, The aforementioned film adsorption unit is The case to which the aforementioned suction pad is attached, A pressing member having a pressing portion that is rotatably mounted in the case around a vertical axis and is movable between an original position located on the same side as the suction pad with respect to the film and an operating position in which the film, while being held in place by the suction pad, is separated from the article, and enters the space formed between the film and the article through the cut portion of the film, and is capable of pressing down the edges around the cut portion of the film in cooperation with the suction pad, The device is configured to include a pressing member drive unit, which is attached to the case and moves the pressing member between the original position and the operating position.

[0007] In this case, for example, the film adsorption unit moving mechanism is A first drive unit moves the film adsorption unit in a front-to-back direction, which is a direction that moves it closer to or further away from the side surface of the workpiece. A second drive unit moves the film adsorption unit in the left-right direction, which is parallel to the side surface of the workpiece. The system can be configured to include a third drive unit that moves the film adsorption unit in the vertical direction.

[0008] Furthermore, for example, the film adsorption unit is configured as a pair such that the adsorption pads are positioned on the left and right sides of a central surface extending in the vertical direction. The first drive unit, the second drive unit, and the third drive unit can be configured to be arranged symmetrically on the left and right sides, corresponding to the configuration of the pair of film adsorption units.

[0009] Furthermore, in order to solve the above problems, the film adsorption unit used in the film cutting apparatus according to the present invention is A film adsorption unit used in a film cutting device that cuts a film that is wrapped around at least the sides of an article, The aforementioned film adsorption unit is A suction pad capable of adsorbing the aforementioned film, The case to which the aforementioned suction pad is attached, A pressing member is mounted in the case so as to be rotatable about an axis in the vertical direction, and has a pressing portion that is movable between an original position located on the same side as the suction pad with respect to the film, and an operating position in which the pressing portion enters the space formed between the film and the article through the cut portion of the film when the film is adsorbed by the suction pad, and is capable of pressing down the peripheral edge of the cut portion of the film in cooperation with the suction pad. The device can be configured to include a pressing member drive unit, which is attached to the case and moves the pressing member between the original position and the operating position. In this case, for example, the film cutting device preferably moves the cut film to a predetermined collection position while adsorbing it, after the film in the workpiece, which includes a pallet, an article placed on the pallet, and a film that wraps around the pallet and the outer periphery of the article to fix the article to the pallet, has been cut.

[0010] Furthermore, in order to solve the above problems, the film recovery method according to the present invention is A film recovery method comprising a workpiece including a pallet, an article placed on the pallet, and a film that wraps around the pallet and the outer periphery of the article to fix the article to the pallet, wherein after the film is cut, the cut film is moved to a predetermined recovery position while being adsorbed onto the suction pad of a film adsorption unit, Before the film is cut, a film contact step is performed in which the suction pad is brought into contact with the film, A film cutting step in which the film, in contact with the suction pad, is cut by the vertical movement of the cutter of the cutter unit, A film separation step is performed to remove the air from the suction pad that is in contact with the film, thereby separating the film that has been adsorbed by the suction pad from the article. A film pressing step is performed by moving the pressing portion of a pressing member, which is rotatably mounted on the case of the film adsorption unit around a vertical axis, from its original position on the same side as the adsorption pad relative to the film, through the cut portion of the film into the space formed between the film and the article, and pressing down the edges around the cut portion of the film in cooperation with the adsorption pad. The system can be configured to include a film peeling step, in which the cut edges of the film, which are held down between the suction pads by the pressing portion, are peeled off the article and moved to a predetermined collection position.

[0011] According to the present invention, the pressing portion of the pressing member is moved by the pressing member driving portion from the original position where it is located on the same side as the suction pad with respect to the film to a working position where it enters through the cutting portion of the film into the space formed between the film and the article when the film adsorbed by the suction pad is separated from the article, and cooperates with the suction pad to press the peripheral edge portion of the film to be cut. Thereby, the film is adsorbed by the suction pad, and the peripheral edge portion of the film to be cut is pressed by the pressing portion and the suction pad, so that it is possible to favorably prevent the film from falling off the suction pad after the film is cut.

Brief Description of the Drawings

[0012] [Figure 1] Perspective view of a depalletizing device including an articulated robot having a film cutting function in one embodiment of the present invention, viewed from obliquely above and behind. [Figure 2] Perspective view of the depalletizing device of FIG. 1, viewed from obliquely above and in front. [Figure 3] Front view of the article suction unit moving mechanism, viewed from behind. [Figure 4] Rear view of the article suction unit moving mechanism, viewed from the front. [Figure 5] Perspective view of the film suction unit when the pressing portion is in the original position, viewed from obliquely above and in front. [Figure 6] Front view of FIG. 5. [Figure 7] Side view of FIG. 5. [Figure 8] Perspective view of the suction unit when the pressing portion is in the operating position, viewed from obliquely above and in front. [Figure 9] Front view of FIG. 8. [Figure 10] Side view of FIG. 8. [Figure 11] Perspective view of a container housing the measurement unit and the cutter unit, viewed from obliquely above and in front. [Figure 12] Perspective view of a container housing the measurement unit and the cutter unit, viewed from obliquely below and in front. [Figure 13] Left side view of Figure 11. [Figure 14] Right side view of Figure 11. [Figure 15] A flowchart showing the sequence of processes performed by the depalletizing device in Figure 1. [Figure 16] A flowchart showing the subroutines executed in the item suction unit movement process shown in Figure 15. [Figure 17] Figure 15 shows a flowchart illustrating the subroutines performed during workpiece side measurement and film cutting processes. [Figure 18] A flowchart showing the subroutines executed in the film recovery process, as shown in Figure 15. [Figure 19] A flowchart showing the subroutines executed during the depalletizing process, as shown in Figure 15. [Figure 20] Figure 15 is an explanatory diagram corresponding to the item suction unit movement process. [Figure 21] Figure 15 is an explanatory diagram corresponding to the workpiece side measurement and film cutting process shown. [Figure 22] Figure 15 is an explanatory diagram corresponding to the film recovery process shown. [Figure 23] Figure 15 is an explanatory diagram corresponding to the film recovery process shown. [Figure 24] Figure 15 is an explanatory diagram corresponding to the depalletizing process. [Figure 25] Figure 15 is an explanatory diagram corresponding to the depalletizing process. [Figure 26] Figure 15 is an explanatory diagram corresponding to the depalletizing process. [Modes for carrying out the invention]

[0013] (Embodiment) Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Figures 1 and 2 show a depalletizing apparatus 1 (hereinafter sometimes simply referred to as apparatus 1) to which the articulated robot having a film cutting function according to the present invention is applied. Apparatus 1 has the function of cutting a film 103 (for example, stretch film) on a workpiece 100, the function of collecting the cut film 103, and the function of transferring (depalletizing) the article 102 on the workpiece 100 from which the film 103 has been removed. Of apparatus 1, the components that perform the function of cutting the film 103 and the function of collecting the cut film 103 correspond to the film cutting apparatus. Note that in Figure 2, the workpiece 100, controller 60, etc. are omitted from the illustration. First, the workpiece 100 will be described.

[0014] The workpiece 100 includes a pallet 101, an article 102 placed on the pallet 101, and a film 103 that wraps around the outer perimeter of the pallet 101 and the article 102, securing the article 102 to the pallet 101. The article 102 consists of multiple packages, such as cardboard boxes used to package products, stacked on the pallet 101 to form a rectangular parallelepiped, but it may also be an article that has a shape other than a rectangular parallelepiped, such as a dozen PET bottles stacked on top of each other. In Figure 1, the workpiece 100 is exemplified as multiple articles 102 of the same size stacked on the pallet 101, but the workpiece is not limited to this, and may be multiple articles of different sizes stacked on the pallet 101, or a single article placed on the pallet 101.

[0015] The film 103 covers the entire circumference of the pallet 101 and the article 102. The film 103 also covers the entire area from the upper end to the lower end of the side surface of the article 102, and at least a portion of the upper end of the side surface of the pallet 101. The upper surface of the article 102 may or may not be covered by the film 103. The workpiece 100 is transported into the apparatus 1 by a transport mechanism 200 including transport rollers. In this embodiment, a transport mechanism 300 is provided in addition to the transport mechanism 200. The transport mechanism 200 is used for loading the workpiece 100, and the transport mechanism 300 is used for unloading the article 102.

[0016] Next, the apparatus 1 will be described. The apparatus 1 comprises a fixed frame 10, a film suction unit moving mechanism 20, a film suction unit 30, an articulated robot 40, and an end effector 50. The fixed frame 10 functions as a base that supports the film suction unit moving mechanism 20 and the articulated robot 40. The fixed frame 10 comprises a first frame 11 located downstream in the direction of transport of the workpiece 100 by the transport mechanism 200, a second frame 12 that supports the film suction unit moving mechanism 20, and a third frame 13 that supports the articulated robot 40.

[0017] The first frame 11 is positioned perpendicular to the direction in which the workpiece 100 is transported by the transport mechanism 200. A work table 14 is installed in the first frame 11 at the destination of the workpiece 100 transported by the transport mechanism 200. The work table 14 is disc-shaped and is sized to adequately accommodate the pallet 101 of the workpiece 100. With the workpiece 100 placed on the work table 14, the film 103 cutting operation is performed on the workpiece 100.

[0018] Two sets of the second frame 12 are provided, with each set positioned at a predetermined distance from the direction in which the first frame 11 extends. Each set of the second frame 12 comprises a pair of vertical frame sections 12a and horizontal frame sections 12b. Each vertical frame section 12a is erected so as to sandwich the first frame 11 between them. The horizontal frame section 12b is connected to the upper end of each vertical frame section 12a in a manner that is twisted relative to the first frame 11. The third frame 13 is positioned on the opposite side from the direction in which the conveying mechanism 200 extends, with the first frame 11 in between.

[0019] In the following explanation, directions will be defined based on the articulated robot 40 supported by the third frame 13. Specifically, in Figure 1, the side where the first frame 11 is located (the side where the workpiece 100 is placed on the work table 14) as seen from the articulated robot 40 will be the forward direction, the side opposite to the first frame 11 will be the rear direction, the left side as seen from the articulated robot 40 (the side where the work table 14 is located) will be the left direction, the right side as seen from the articulated robot 40 (the side opposite to where the work table 14 is located) will be the right direction, the upper side (towards the ceiling) as seen from the articulated robot 40 will be the upward direction, and the lower side (towards the ground) as seen from the articulated robot 40 will be the downward direction. The forward / backward direction can be rephrased as the first direction, the left / right direction as the second direction, and the up / down direction as the third direction.

[0020] As shown in Figures 3 and 4, the film adsorption unit moving mechanism 20 is provided for each set of second frame bodies 12 and is symmetrically arranged with respect to a central plane F that bisects the space between the second frame bodies 12. The film adsorption unit moving mechanism 20 moves the film adsorption unit 30 in the forward / backward, left / right, and up / down directions. Specifically, the film adsorption unit moving mechanism 20 includes an electric actuator 21 for moving the film adsorption unit 30 in the forward / backward direction, an electric actuator 22 for moving it in the up / down direction, and an electric actuator 23 for moving it in the left / right direction.

[0021] The electric actuator 21 comprises a linear guide 21a and a slider 21b. The slider 21b is slidably supported on the linear guide 21a and is driven by a drive source including a servo motor and a ball screw (not shown). The electric actuator 22 comprises a linear guide 22a, a slider 22b, and an arm 22c. The slider 22b is slidably supported on the linear guide 22a and is driven by a drive source including a servo motor and a ball screw (not shown). The arm 22c is in the shape of a substantially trapezoidal plate and is fixed to the slider 22b at its height side portion 22c1. The arm 22c is cantilevered to the slider 22b with the height side portion 22c1 as its base end. The electric actuator 23 comprises a linear guide 23a and a slider 23b. The linear guide 23a is fixed to the lower base portion 22c2 of the arm 22c of the electric actuator 22. The slider 23b is slidably supported on the linear guide 23a and driven by a drive source including a servo motor and a ball screw (not shown). The electric actuator 21 corresponds to the first drive unit of the present invention, the electric actuator 23 corresponds to the second drive unit of the present invention, and the electric actuator 22 corresponds to the third drive unit of the present invention.

[0022] The linear guide 22a of electric actuator 22 is fixed to the slider 21b of electric actuator 21. The linear guide 23a of electric actuator 23 is fixed to the arm 22c of electric actuator 22. As a result, when the slider 21b of electric actuator 21 moves in the forward and backward direction, electric actuator 23 moves in the forward and backward direction together with electric actuator 22.

[0023] The film suction unit 30 is mounted on the slider 23b of the electric actuator 23. As a result, the film suction unit 30 moves left and right in accordance with the left-right movement of the slider 23b of the electric actuator 23. The film suction unit 30 also moves up and down in accordance with the up-down movement of the slider 22b of the electric actuator 22. Furthermore, the film suction unit 30 moves back and forth in accordance with the front-back movement of the slider 21b of the electric actuator 21. When the film suction unit 30 moves forward, it approaches the side of the workpiece 100, and when it moves backward, it moves away from the side of the workpiece 100.

[0024] The film adsorption unit 30 is set to remain in the original position shown in Figures 1 to 4 before each of the processes described later is performed. Specifically, the original position of the film adsorption unit 30 is defined as the state in which the slider 21b of the electric actuator 21 is located at the rearmost end of the linear guide 21a, the slider 23b of the electric actuator 23 is located at the frontmost (freest) end of the linear guide 23a, and the slider 22b of the electric actuator 22 is located at the uppermost end of the linear guide 22a.

[0025] Since the film suction unit moving mechanism 20 is symmetrically arranged with respect to the central plane F, the film suction unit 30 is also symmetrically arranged with respect to the central plane F. As shown in Figures 5 to 7, the film suction unit 30 comprises a suction pad 31, a case 32, a pressing member 33, and a pressing member drive unit 34.

[0026] The suction pad 31 is shaped like a suction cup, including an elastically contractible bellows, and is attached to the case 32 so as to face the side of the workpiece 100. The suction pad 31 is in contact with the film 103, which is the object to be adsorbed, that is, it is pressed against the film 103 while elastically contracted by a very small amount. The suction pad 31 is able to adsorb the film 103 by reducing the pressure inside the suction pad 31 while it is in contact with the film 103.

[0027] The case 32 is a rectangular parallelepiped enclosed on six sides, and upper and lower plates 32a and 32b are attached to its top and bottom surfaces, respectively, so as to protrude from each surface toward the central surface F. A bracket 35 is attached to the upper plate 32a, and the case 32 is fixed to the slider 23b of the electric actuator 23 via the bracket 35 (see Figures 3 and 4). A vacuum hose 36 is attached to the side of the case 32 toward the central surface F. The case 32 is connected to a vacuum source (not shown) via the vacuum hose 36, and the inside of the case 32 is depressurized when the vacuum source is driven. A distance sensor 37 is also attached to the case 32 so as to face the side surface of the workpiece 100. Based on the value detected by the distance sensor 37, the contact position of the suction pad 31 with respect to the side surface of the workpiece 100 is set.

[0028] The retaining member 33 comprises an upper arm 33a, a lower arm 33b, and a retaining portion 33c. Both the upper arm 33a and the lower arm 33b are formed in a substantially L-shape, with the tip of the vertical bar of the L-shape serving as the base end attached to the case 32, and the horizontal bar of the L-shape serving as the free end, and are arranged opposite each other vertically. A shaft portion 33d is integrally attached to the base end of the lower arm 33b perpendicular to the upper surface of the lower arm 33b. A lower through-hole (not shown) through which the shaft portion 33d can be inserted is formed in the lower plate material 32b, which is attached to the lower surface of the case 32b, and a bearing portion 32c is attached to the upper surface of the lower plate material 32b corresponding to the lower through-hole. The shaft portion 33d of the lower arm 33b is assembled to the bearing portion 32c from the lower side of the lower plate material 32b, passing through the lower plate material 32b, and is rotatably supported by the bearing portion 32c.

[0029] On the other hand, the upper plate material 32a, which is attached to the upper surface of the case 32, has an upper through hole (not shown) through which the drive shaft (not shown) of the retaining member drive unit 34 can be inserted. The upper arm 33a is positioned below the upper plate material 32a and is integrated with the drive shaft of the retaining member drive unit 34 which penetrates the upper plate material 32a. When the retaining member drive unit 34 is attached to the upper plate material 32a, the drive shaft of the retaining member drive unit 34 is configured to be located on the same axis L1 as the shaft portion 33d of the lower arm 33b.

[0030] The retaining portion 33c includes a strip-shaped plate portion in the middle and is formed in an overall shape that is roughly U-shaped. It is attached at both ends to the upper arm 33a and the lower arm 33b by mounting members 33e, which include mounting screws. As a result, the retaining portion 33c moves integrally with the upper arm 33a and the lower arm 33b when driven by the retaining member drive unit 34.

[0031] The presser member drive unit 34 is composed of an electric actuator such as a servo motor having a drive shaft, and its main body is attached to the upper plate material 32a of the case 32. The presser member drive unit 34 moves the presser member 33 from the original position shown in Figures 3 to 7 to the operating position shown in Figures 8 to 10, and also moves it from the operating position back to the original position. In both film suction units 30, the presser member drive units 34 are driven synchronously. As a result, when the presser member 33 is in the original position shown in Figures 3 to 7, the upper arm 33a and lower arm 33b of each presser member 33 both extend toward the center plane F, and each presser portion 33c is positioned away from the suction pad 31. On the other hand, when the presser member 33 is in the operating position shown in Figures 8 to 10, the distance D from the axis L1 of the shaft portion 33d of the lower arm 33b to the inner surface of the presser portion 33c is set such that the inner surface of the presser portion 33c is in contact with the tip of the suction pad 31, which is in a free state (see Figure 10).

[0032] Returning to Figures 1 and 2, the articulated robot 40 is an industrial robot with a serial link mechanism, and in this embodiment, a 6-axis vertical articulated robot is used. The articulated robot 40 is supported by a base 41 on the third frame 13 of the fixed frame 10. The articulated robot 40 consists of a head 42, a first arm 43, a second arm 44, and a wrist section 45 as robot arms, and a rotation mechanism that connects them to each other. An end effector 50 is connected to the wrist section 45 as the tip of the robot arm.

[0033] As shown in Figures 11 to 14, the end effector 50 comprises a housing 51, a measuring unit 52, a cutter unit 53, and an article suction unit 54. The housing 51 is rectangular in shape and comprises a frame member 51a, a partition plate 51b, an upper connecting part 51c, and a lower connecting part 51d. The frame member 51a comprises vertical frame parts 51a1 arranged corresponding to the longitudinal sides of the rectangular parallelepiped, horizontal frame parts 51a2 arranged corresponding to the short sides, and height frame parts 51a3 arranged corresponding to the height sides, with the ends of adjacent frame parts 51a1, 51a2, and 51a3 connected at the vertices of the rectangular parallelepiped. The partition plate 51b is connected to the height frame part 51a3, and the interior of the housing 51 is divided into an upper space S1 and a lower space S2 by the partition plate 51b.

[0034] The connecting section 51c integrally comprises large and small circular mounting plates 51c1 and 51c2, each having a through hole in the center, and a cylindrical column 51c3 that is coaxially connected to the mounting plates 51c1 and 51c2. Mounting plate 51c1 is attached to a vertical frame 51a1 located on the ceiling side. Mounting plate 51c2 is attached to the wrist 45 of the articulated robot 40. The connecting section 51d integrally comprises a circular mounting plate 51d1 and a cylindrical column 51d2 that is coaxially connected to the mounting plate 51d1. Mounting plate 51d1 is attached to a vertical frame 51a1 located on the ground side. The column 51d2 is attached to the upper part of the object suction unit 54.

[0035] The measuring unit 52 has the function of measuring the horizontal position on the side surface of the workpiece 100 according to each vertical position as the wrist portion 45 of the articulated robot 40 moves vertically. The measuring unit 52 is housed in the upper space S1 of the housing 51. The measuring unit 52 comprises a measuring roller 52a, a roller support portion 52b, a base portion 52c, an electric actuator 52d, a first spring fixing portion 52e, a second spring fixing portion 52f, a spring 52g, and a position detection portion 52h.

[0036] The measuring roller 52a is supported by the roller support portion 52b so as to be rotatable about its axis by a shaft portion 52b1 that extends parallel to the horizontal frame portion 51a2 of the frame material 51a. The roller support portion 52b includes two longitudinal plate members that extend parallel to the vertical frame portion 51a1 of the frame material 51a, and is supported by the base portion 52c so as to be movable in a direction parallel to the vertical frame portion 51a1. The base portion 52c has a vertical wall portion 52c1 and a bottom wall portion 52c2, the vertical wall portion 52c1 supports the roller support portion 52b, and the bottom wall portion 52c2 is attached to the slider 52d2 of the electric actuator 52d.

[0037] The electric actuator 52d comprises a linear guide 52d1 and a slider 52d2. The linear guide 52d1 is mounted on the upper surface of the partition plate 51b. The slider 52d2 is slidably supported on the linear guide 52d1 and is driven by a drive source including a rodless cylinder (not shown).

[0038] The first spring fixing part 52e is attached to the bottom wall part 52c2 of the base part 52c. The first spring fixing part 52e includes a spring mounting shaft 52e1. One end of the spring 52g is connected to the spring mounting shaft 52e1, so that the spring 52g can be pulled out or wound up around the axis of the spring mounting shaft 52e1. The second spring fixing part 52f is attached to the rear end of the roller support part 52b, opposite to the front end where the measuring roller 52a is provided. The other end of the spring 52g (the opposite end from the one end on the mounting shaft 52e1 side) is connected to the second spring fixing part 52e.

[0039] The spring 52g is a constant-load spring, and its spring load (biasing force) is constant regardless of the amount it is pulled out from the first spring fixing part 52e. When the measuring roller 52a measures the horizontal position on the side surface (film 103) of the workpiece 100, the spring 52g is pulled out by a predetermined amount from the first spring fixing part 52e, and the biasing force caused by the elastic return of the spring 52g presses the measuring roller 52a against the side surface of the workpiece 100. Therefore, even if the side surface of the workpiece 100 has an uneven shape in the horizontal direction, the biasing force of the spring 52g causes the measuring roller 52a to follow the side surface of the workpiece 100, so that the horizontal position on the side surface of the workpiece 100 can be measured with almost certainty.

[0040] The position detection unit 52h detects the horizontal position of the measuring roller 52a while it is in contact with the side surface of the workpiece 100. The position detection unit 52h is composed of, for example, a magnetic scale 52h1 and a magnetic scale sensor 52h2. The magnetic scale 52h1 is in the shape of an elongated strip and is attached to the side surface of the roller support 52b. The magnetic scale sensor 52h2 is attached to the bottom wall 52c2 of the base 52c, facing the magnetic scale 52h1. The magnetic scale sensor 52h2 detects the position information recorded on the magnetic scale 52h1 and outputs a signal of that position information.

[0041] The cutter unit 53 has the function of cutting the film 103 of the workpiece 100 vertically according to the measurement results from the measuring unit 52 as the wrist portion 45 of the articulated robot 40 moves vertically. The cutter unit 53 comprises a cutter 53a, a base portion 53b, and an electric actuator 53c. The cutter 53a is a component for cutting the film 103, and is, for example, a hot air heater. Alternatively, an ultrasonic cutter or a heat cutter may be used instead of a hot air heater. The cutter 53a is attached to the base portion 53b via a bracket 53d.

[0042] The base portion 53b is a longitudinal plate shape extending parallel to the vertical frame portion 51a1 of the frame material 51a, and is attached to the slider 53c2 of the electric actuator 53c. The electric actuator 53c comprises a linear guide 53c1 and a slider 53c2. The linear guide 52c1 is attached to the lower surface of the partition plate 51b. The slider 53c2 is slidably supported by the linear guide 53c1 and is driven by a drive source including a servo motor 53c3 and a ball screw 53c4. During the cutting of the film 103, the electric actuator 53c is constantly driven and controlled so that the cutter unit 53 follows the travel trajectory of the measuring roller 52a while maintaining a state in which the cutter 53a is at a predetermined distance from the surface of the workpiece 100 according to the measurement results from the measuring unit 52.

[0043] The article suction unit 54 has the function of picking up the article 102 from the workpiece 100 after the film 103 has been cut and transferring it from one pallet 101 to another pallet as the wrist portion 45 of the articulated robot 40 moves. The article suction unit 54 is, for example, a well-known vacuum unit and comprises a unit body 54a and a sponge portion 54b. The unit body 54a has a unitized mechanism for forming a vacuum, such as an ejector, various valves, and a pressure detection switch built into it, and an air piping connection portion 54c communicating with the sponge portion 54b is provided on the outside. The sponge portion 54b is a porous material that can contact and adsorb the article to be suctioned and is attached to the unit body 54a via a plate 54d.

[0044] The articulated robot 40 is initially in the state shown in Figures 1 and 2. In this initial state, the measuring roller 52a of the measuring unit 52 and the cutter 53a of the cutter unit 53 are positioned between the left and right film suction units 30, and do not come into contact with the film 103 on the workpiece 100. This state is considered the original position of the housing 51.

[0045] Returning to Figure 1, the apparatus 1 includes a controller 60 that controls the film suction unit moving mechanism 20, the film suction unit 30, the articulated robot 40, and the end effector 50. The controller 60's main components are a microcomputer including a CPU 61, memory 62, and input / output interface circuits (not shown). For example, the memory 62 stores and stores the article suction unit moving program, the workpiece side measurement and film cutting program, the film retrieval program, and the depalletizing (article transfer) program, which will be described later. Based on detection signals from various sensors 71 provided in the system 1, the controller 60 controls the film suction unit moving mechanism 20, the film suction unit 30, the articulated robot 40, and the end effector 50 in a predetermined order. The controller 60 is also electrically connected to an input unit 72 that receives input from the user and a display unit 73 that displays the input content of the input unit 72.

[0046] Next, using the apparatus 1 configured as described above, the processes of cutting the film 103 on the workpiece 100, collecting the cut film 103, and transferring the article 102 from the workpiece 100 from which the film 103 has been removed will be explained with reference to the explanatory diagrams in Figures 20 to 26. When these processes are executed, the controller 60 executes the program as the main routine shown in the flowchart of Figure 15. As a prerequisite for the execution of the program in Figure 15, the workpiece 100 is transported and positioned on the work table 14 of the first frame 11 by the transport mechanism 200. In addition, the front-to-back, left-to-right, and up-and-down dimensions of the workpiece 100, as well as the height of the pallet, etc., are pre-input by operations at the input unit 72.

[0047] First, the controller 60 moves the film suction unit 30 (S1). In the process of S1, a program as a subroutine shown in the flowchart of Figure 16 is executed. In the program of Figure 16, first, the film suction unit 30 is moved up and down and left and right from its original position according to the shape of the workpiece 100 (S11). Specifically, as shown in Figure 20, the drive of the electric actuator 22 is controlled to move the suction unit 30 up and down, and the drive of the electric actuator 23 is controlled to move it left and right, so that the suction pad 31 of the film suction unit 30 faces one of the upper half of the workpiece 100.

[0048] Next, based on the value detected by the distance sensor 37, the film suction unit 30 is advanced to a position where it contacts the workpiece 100 (film 103) (S12). Specifically, as shown in Figure 22(a), the drive of the electric actuator 21 is controlled to move the film suction unit 30 forward until the suction pad 31 contacts the film 103. Since the article 102 is packaged with the film 103 having appropriate tension, the film 103 instantly contracts from the cut point, making it easy for the cut point to open wide. If the cut point opens wide, it may hinder the subsequent retrieval of the film 103. Therefore, by performing the process in S1 of Figure 15 and the processes in S11 to S12 of Figure 16, the film 103 is pressed appropriately by the film suction pad 31 when the film 103 is cut, the cutting process is stabilized, and a wide opening of the cut point can be effectively prevented. The execution of the process S1 in Figure 15 and the processes S11 to S12 in Figure 16 by the controller 60 corresponds to the film contact process of the present invention.

[0049] After executing the program in Figure 16, the program returns to the program in Figure 15, causing the measuring unit 52 to measure the side of the workpiece 100 and the cutter unit 53 to cut the film 103 (S2). In process S2, a program as a subroutine shown in the flowchart of Figure 17 is executed. In this program, as shown in Figure 20, the drive of the articulated robot 40 is controlled to lower the housing 51 until the measuring roller 52a of the measuring unit 52 is at approximately the same height as the lower end of the film 103 on the workpiece 100 (S21).

[0050] Next, the drive of the electric actuator 52d in the measuring unit 52 is controlled to advance the slider 52d2 along the linear guide 52d1, and the base portion 52c and roller support portion 52b are advanced until the measuring roller 52a is pressed against the side of the workpiece 100 by the biasing force of the spring 52g (S22) (see Figures 13 and 14). Also, the drive of the electric actuator 53c in the cutter unit 53 is controlled to advance the slider 53c2 along the linear guide 53c1, and the base portion 53b and cutter 53a are advanced (S23). The advanced position of the cutter 53a is a suitable position for the cutter 53a to cut the film 103 on the workpiece 100, and is calculated in correspondence with the position of the measuring roller 52a.

[0051] After the execution of process S23, the drive of the articulated robot 40 is controlled to raise the housing 51, as shown in Figure 21 (S24). During this raising process of the housing 51, the horizontal position of the side surface of the workpiece 100 is measured by the measuring unit 52. Specifically, while the measuring unit 52 is rising, the magnetic scale sensor 52h2 (see Figure 13) is made to sequentially read the position information recorded on the magnetic scale 52h1, and this position information is associated with the vertical position of the housing 51 and stored in the memory 62 of the controller 60 (see Figure 1). This position information indicates the horizontal position of the side surface of the workpiece 100 that the measuring roller 52a contacts.

[0052] As the measuring roller 52a rises, it moves horizontally to follow the horizontal position of the side surface of the workpiece 100 based on the biasing force of the spring 52g. That is, if the horizontal position of the side surface of the workpiece 100 changes to the front of the workpiece 100, the measuring roller 52a also moves forward due to the biasing force of the spring 52g. On the other hand, if the position of the side surface of the workpiece 100 changes to the rear of the workpiece 100, the measuring roller 52a also moves backward against the biasing force of the spring 52g.

[0053] While the measuring roller 52a is rising (while measuring the lateral position of the workpiece 100), the cutter 53a of the cutter unit 53 is made to cut the film 103. Specifically, while the cutter 53a is rising, the horizontal position of the cutter 53a is controlled according to the horizontal position of the workpiece 100 corresponding to the vertical position of the measuring roller 52a stored in the memory 62. That is, if the horizontal position of the workpiece 100 changes to the front of the workpiece 100, the drive of the electric actuator 53c in the cutter unit 53 is controlled to move the cutter 53a forward. On the other hand, if the horizontal position of the workpiece 100 changes to the rear of the workpiece 100, the drive of the electric actuator 53c is controlled to move the cutter 53a backward.

[0054] Next, it is determined whether the cutter 53a has reached the upper end of the workpiece 100 (S25). If the cutter 53a has not reached the upper end of the workpiece 100 (S25: No), the raising of the housing 50 (measurement by the measuring unit 52 and cutting by the cutter unit 53) continues (S24). If the cutter 53a has reached the upper end (S25: Yes), the execution of the program in Figure 17 ends and the program in Figure 15 returns.

[0055] Next, the controller 60 causes the film 103, after cutting, to be collected by the film suction unit 30 (S3). In the S3 process, a program as a subroutine, as shown in the flowchart of Figure 18, is executed. In this program, as shown in Figure 22(a), the air inside the suction pad 31, which is in contact with the film 103, is removed, and the film 103 is adsorbed onto the suction pad 31 (S31). With the film 103 adsorbed by the suction pad 31, as shown in Figure 22(b), the drive of the electric actuator 21 (see Figures 3 and 4) is controlled to separate the film 103 from the article 102, and the film suction unit 30 is retracted until a space S is created between the film 103 and the side of the article 102 (S32). The space S is set to be large enough for the pressing part 33c to sufficiently enter between the tip of the suction pad 31, i.e., between the adsorbed film 103 and the side of the article 102.

[0056] After the execution of process S32, the drive of the pressing member drive unit 34 is controlled to move the pressing member 33 from the original position shown in Figure 22(b) to the operating position shown in Figure 22(c) (S33). As a result, the pressing portion 33c of the pressing member 33 enters the space S formed between the film 103 and the side surface of the article 102 through the cut portion 103a of the film 103, and works in cooperation with the suction pad 31 to press down on the cut edge 103b of the film 103.

[0057] After the execution of process S33, as shown in Figures 22(d), 23, and 24, the drive of the electric actuator 23 is controlled to move both film suction units 30 to the left and right end positions of the linear guide 23a opposite to the center plane F (see Figures 3 and 4). Subsequently, the drive of the electric actuator 21 is controlled to move both film suction units 30 to the foremost position of the linear guide 21a (S34). The foremost position of the linear guide 21a is designated as the film retrieval position. During the process of the film suction units 30 moving to the film retrieval position, the film 103 is peeled off from the article 102.

[0058] When the film suction unit 30 reaches the foremost position of the linear guide 21a, the film 103 is held by a film holding mechanism (not shown). When the film 103 is held by the film holding mechanism, the film suction unit 30 stops the operation of removing air from the suction pad 31 and controls the drive of the pressing member drive unit 34 to move the pressing member 33 from the operating position to the original position (S35, see Figure 24). This allows the film 103 to be smoothly transferred from the film suction unit 30 to the film holding mechanism. The film 103 is sent to a predetermined disposal position by the film holding mechanism. The execution of the process in S3 in Figure 15 and the processes in S31 and S32 in Figure 18 by the controller 60 corresponds to the film separation process of the present invention, the execution of the process in S33 in Figure 18 corresponds to the film pressing process of the present invention, and the execution of the process in S34 in Figure 18 corresponds to the film peeling process of the present invention.

[0059] After executing the program in Figure 18, the program returns to the program in Figure 15, causing the articulated robot 40 to perform depalletizing (S4). In process S4, a program as a subroutine shown in the flowchart of Figure 19 is executed. In this program, as shown in Figures 24 to 26, the drive of the articulated robot 40 (head 42, first arm 43, second arm 44, wrist section 45) (see Figure 1) is controlled to move the container 51 onto the item 102 to be depalletized (S41). The item suction unit 54 is made into a vacuum state to pick up the item 102 (S42). With the item 102 held in place, the drive of the articulated robot 40 is controlled to transfer the picked-up item 102 onto the pallet 301 (S43).

[0060] Next, it is determined whether there are any items 102 to be depalled remaining (S44). If there are items 102 remaining (S44: Yes), the processes in S41 to S43 are repeated. If there are no more items 102 to be depalled (S44: No), the execution of the program in Figure 19 is terminated. After that, the execution of the program in Figure 15 is terminated.

[0061] As is clear from the above description, in the above embodiment, the pressing portion 33c of the pressing member 33 in the film adsorption unit 30 is configured such that, by the pressing member drive unit 34, the pressing portion 33c of the pressing member 33 moves from its original position on the same side as the adsorption pad 31 relative to the film 103, away from the article 102 as the film 103 adsorbed by the adsorption pad 31 moves into the space S formed between the film 103 and the article 102, through the cut portion 103a of the film 103, and works in cooperation with the adsorption pad 31 to press down on the cut peripheral edge 103b of the film 103. As a result, the film 103 is adsorbed by the adsorption pad 31, and the cut peripheral edge 103b of the film 103 is pressed down by the pressing portion 33c and the adsorption pad 31, so that the film 103 does not fall off the adsorption pad 31 after the film 103 has been cut.

[0062] Furthermore, in the above embodiment, the film adsorption unit moving mechanism 20 is configured to include an electric actuator 21 as a first drive unit that moves the film adsorption unit 30 in the front-rear direction, which is a direction toward or toward the side surface of the workpiece 100; an electric actuator 22 as a second drive unit that moves the film adsorption unit 30 in the left-right direction, which is a direction parallel to the side surface of the workpiece 100; and an electric actuator 23 as a third drive unit that moves the film adsorption unit 30 in the up-down direction. This allows the film adsorption unit moving mechanism 20 to smoothly carry out a series of operations from before cutting the film 103 to after cutting the film 103 and to the collection of the film 103, depending on the shape of the workpiece 100.

[0063] Furthermore, in the above embodiment, the film adsorption unit 20 is configured as a pair such that the adsorption pads 31 are positioned on the left and right sides with respect to a central plane F that extends in the vertical direction. Corresponding to the pair configuration of the film adsorption unit 20, the electric actuator 21 as the first drive unit, the electric actuator 22 as the second drive unit, and the electric actuator 23 as the third drive unit are configured to be positioned symmetrically on the left and right sides. As a result, after the film 103 is cut, the left and right edges around the cut point of the film 103 are pressed down, and the film 103 is peeled off simultaneously on both sides, allowing the film 103 to be recovered quickly.

[0064] Furthermore, in the above embodiment, the film 103, in contact with the suction pad 31, is cut by the vertical movement of the cutter 53a of the cutter unit 53. This effectively prevents the cut area from opening up when the film 103 is cut.

[0065] Furthermore, in the above embodiment, the air inside the suction pad 31 in contact with the film 103 is removed, the film 103 which is being held by the suction pad 31 is separated from the article 102, and the pressing portion 33c of the pressing member 33 is moved into the space S formed between the film 103 and the article 102 through the cut portion of the film 103. This ensures that the pressing portion 33c is almost certainly moved into the space S.

[0066] Furthermore, in the above embodiment, a multi-joint robot 40 having a film cutting function was used as the film cutting device, but the film cutting device is not limited to this, and may be of a type in which a measuring unit, cutter unit, etc. are housed in a housing, such as the one described in Patent Document 1 above.

[0067] In the above embodiment, the film adsorption unit 20 is configured as a pair such that the adsorption pads 31 are arranged on the left and right sides with respect to a central plane F extending in the vertical direction, and the electric actuator 21 as the first drive unit, the electric actuator 22 as the second drive unit, and the electric actuator 23 as the third drive unit are arranged symmetrically on the left and right sides to correspond to the pair configuration of the film adsorption unit 20. However, the invention is not limited to this configuration, and for example, the film adsorption unit 20 and the electric actuator 21 as the first drive unit, the electric actuator 22 as the second drive unit, and the electric actuator 23 as the third drive unit may be provided on only one side, either the left or the right.

[0068] Furthermore, in the above embodiment, the film adsorption unit 30 was configured to adsorb the film 103 in a workpiece 100 which included a pallet 101, an article 102 placed on the pallet 101, and a film 103 that wrapped around the outer periphery of the pallet 101 and the article 102, fixing the article 102 to the pallet 101. However, the invention is not limited to this, and can also be applied to films in workpieces where, for example, the pallet is omitted and at least the sides of the article are wrapped in film.

[0069] Furthermore, although the above embodiment employs a multi-joint robot 40 as a component of the film cutting apparatus according to the present invention, the invention is not limited to this and can also be applied to devices in which a measuring unit, a cutter unit, and an object suction unit are provided on a fixed frame, for example.

[0070] Furthermore, the present invention is not limited to the embodiments described above and their variations, but can be implemented in any form that integrates, omits, or modifies as appropriate without departing from the spirit of the invention. [Explanation of Symbols]

[0071] 1. Depalletizing device 10 Fixed frame (film cutting device) 14 Work Table 20. Film adsorption unit moving mechanism (film cutting device) 21, 22, 23 Electric Actuators 30. Film adsorption unit (film cutting device) 31 Suction pads 40. Articulated robot (film cutting device) 41 Base 42 Heads (Robot Arms) 43. First Arm (Robot Arm) 44. Second Arm (Robot Arm) 45. Wrist section (robot arm) 50 End Effectors 51 containment units 52. Measuring Unit (Film Cutting Device) 52a Measuring roller 53 Cutter Unit (Film Cutting Device) 53a Cutter 54. Object Suction Unit 100 Work 101 Palette 102 Goods 103 film 200, 300 Conveying Mechanism

Claims

1. A film cutting device for cutting a film in a workpiece that includes a pallet, an article placed on the pallet, and a film that wraps around the pallet and the outer periphery of the article to fix the article to the pallet, A measuring unit that moves in the vertical direction and measures the horizontal position on the side surface of the workpiece corresponding to each position in the vertical direction, A cutter unit that moves vertically together with the measuring unit and cuts the film by moving horizontally according to the measurement results measured by the measuring unit, A film adsorption unit having an adsorption pad capable of adsorbing the aforementioned film, The film adsorption unit is supported so as to be movable in a direction in which the adsorption pad approaches or moves away from the film, and the film adsorption unit moving mechanism further moves the film adsorption unit to a predetermined recovery position so as to peel the film, which is adsorbed by the adsorption pad, from the article, The aforementioned film adsorption unit is The case to which the aforementioned suction pad is attached, A pressing member having a pressing portion that is rotatably mounted in the case around a vertical axis and is movable between an original position located on the same side as the suction pad with respect to the film and an operating position in which the film, while being held in place by the suction pad, is separated from the article, and enters the space formed between the film and the article through the cut portion of the film, and is capable of pressing down the edges around the cut portion of the film in cooperation with the suction pad, A film cutting device comprising a pressing member drive unit attached to the case, which moves the pressing member between the original position and the operating position.

2. The aforementioned film adsorption unit moving mechanism is A first drive unit moves the film adsorption unit in a front-to-back direction, which is a direction that moves it closer to or further away from the side surface of the workpiece. A second drive unit moves the film adsorption unit in the left-right direction, which is parallel to the side surface of the workpiece. A third drive unit that moves the film adsorption unit in the vertical direction, A film cutting apparatus according to claim 1, comprising:

3. The film adsorption unit is configured as a pair such that the adsorption pads are positioned on the left and right sides of a central surface extending in the vertical direction. The film cutting apparatus according to claim 2, wherein the first drive unit, the second drive unit, and the third drive unit are each arranged symmetrically to correspond to the configuration of the pair of film adsorption units.

4. A film adsorption unit used in a film cutting device that cuts a film that is wrapped around at least the sides of an article, The aforementioned film adsorption unit is A suction pad capable of adsorbing the aforementioned film, The case to which the aforementioned suction pad is attached, A pressing member is mounted in the case so as to be rotatable about a vertical axis, and has a pressing portion that is movable between an original position located on the same side as the suction pad with respect to the film, and an operating position in which the film, while being held in place by the suction pad, is separated from the article, and enters the space formed between the film and the article through the cut portion of the film, and is capable of pressing down the peripheral edge of the cut portion of the film in cooperation with the suction pad. A film adsorption unit used in a film cutting device, comprising a pressing member drive unit attached to the case and for moving the pressing member between the original position and the operating position.

5. A film recovery method comprising a workpiece including a pallet, an article placed on the pallet, and a film that wraps around the pallet and the outer periphery of the article to fix the article to the pallet, wherein after the film is cut, the cut film is moved to a predetermined recovery position while being adsorbed onto the suction pad of a film adsorption unit, Before the film is cut, a film contact step is performed in which the suction pad is brought into contact with the film, A film cutting step in which the film, in contact with the suction pad, is cut by the vertical movement of the cutter of the cutter unit, A film separation step is performed to remove the air from the suction pad that is in contact with the film, thereby separating the film that is adsorbed by the suction pad from the article. A film pressing step is performed by moving the pressing portion of a pressing member, which is rotatably mounted on the case of the film adsorption unit around a vertical axis, from its original position on the same side as the adsorption pad relative to the film, through the cut portion of the film into the space formed between the film and the article, and pressing down the edges around the cut portion of the film in cooperation with the adsorption pad. A film recovery method comprising a film peeling step of peeling the cut edge of the film, which is pressed between the suction pads by the pressing portion, from the article and moving it to a predetermined recovery position.

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