Film cutting device

Abstract

The present invention provides a film cutting device that can cut a film vertically even when the horizontal position of a workpiece, including a pallet, an article placed on the pallet, and a film wrapping the pallet and the article, changes along the vertical direction. [Solution] The film cutting device 1 includes a measuring unit that moves vertically and measures the horizontal position of the side surface of the workpiece according to each vertical position, a cutter that cuts the film, and a cutter drive unit that moves the cutter vertically and controls the horizontal position of the cutter according to the measurement results from the measuring unit. The measuring unit measures the side surface position of the pallet in addition to the side surface position of the article. The cutter cuts the portion of the film that covers the side surface of the article in addition to the portion that covers the side surface of the pallet.

Description

Technical Field

[0001] The present disclosure relates to a film cutting device for cutting a film that wraps around the outer periphery of an article placed on a pallet.

Background Art

[0002] Regarding the above film cutting device, for example, there is a proposal in Patent Document 1 below. Patent Document 1 describes moving a heat cutter up and down to cut the film.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the device of Patent Document 1, when the position of the workpiece including the pallet, the article, and the film in the horizontal direction changes along the vertical direction, the film cannot be cut in the vertical direction.

[0005] In view of the above circumstances, the present disclosure aims to provide a film cutting device that can cut the film in the vertical direction even when the position of the workpiece in the horizontal direction changes along the vertical direction.

Means for Solving the Problems

[0006] The film cutting device of the present disclosure is a device for cutting the 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 in a state fixed to the pallet, a measuring unit that measures the position of the side surface of the workpiece in the horizontal direction corresponding to each position in the vertical direction while moving in the vertical direction A cutter for cutting the aforementioned film, The system includes a cutter drive unit that moves the cutter vertically and controls the position of the cutter horizontally according to the measurement results from the measuring unit, The measuring unit measures the lateral position of the pallet in addition to the lateral position of the article. The cutter cuts not only the portion of the film that covers the side of the article, but also the portion that covers the side of the pallet.

[0007] According to this, when the cutter is moved vertically to cut the film, the measuring unit controls the horizontal position of the cutter according to the lateral position of the workpiece being measured. Therefore, even if the horizontal position of the workpiece changes along the vertical direction, the film can be cut vertically. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of a film cutting device. [Figure 2] This is a side view of a film cutting device and the workpiece positioned in front of it. [Figure 3] This is a front view of the film cutting device. [Figure 4] This is a side view showing a part of a film cutting apparatus including a suction unit, in which the suction pads are positioned opposite the side of the workpiece with a gap between them. [Figure 5] This is a side view showing a part of a film cutting apparatus including a suction unit, where the suction pad has advanced from the state shown in Figure 4 and is in contact with the side of the workpiece. [Figure 6] This is a side view showing a part of a film cutting device including a suction unit, illustrating the state in which a space is formed between the film and the article or pallet as the suction pad retracts from the state shown in Figure 5. [Figure 7] This is an enlarged view of section A in Figure 4, showing the main parts of the adsorption unit. [Figure 8]This diagram shows the main components of the measuring unit and cutting unit. [Figure 9] This is a flowchart of the film cutting process. [Figure 10] Figure 9 is a flowchart detailing step S2. [Figure 11] Figure 9 is a flowchart detailing step S3. [Figure 12] This diagram shows the simultaneous measurement by the measuring unit and the cutting of the film by the cutting unit. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described below with reference to the drawings. Figures 1 to 3 show the film cutting apparatus 1 (hereinafter sometimes simply referred to as the apparatus) of this embodiment. Note that Figure 2 shows the workpiece 100 placed in front of the apparatus 1. The workpiece 100 is not shown in Figures 1 and 3. First, the workpiece 100 will be described.

[0010] The workpiece 100 includes a pallet 101, an article 102 placed on the pallet 101, and a stretch film 103 (hereinafter sometimes simply referred to as "film") 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 is, for example, a rectangular package containing a product and the cardboard box that packages it, but it may also be of other types or shapes other than a rectangular prism, such as a PET bottle. Figure 2 shows an example in which one article 102 is placed on the pallet 101, but multiple articles of different sizes or the same size may be placed on the pallet 101 stacked on top of each other.

[0011] The film 103 covers the entire circumference of the pallet 101 and the article 102. Furthermore, the film 103 covers the entire area from the top to the bottom of the side surface of the article 102, and covers at least a portion of the side surface of the pallet 101 from the top. The top surface of the article 102 may or may not be covered by the film 103.

[0012] The workpiece 100 is conveyed to the front of the apparatus 1 by a conveying unit 200 configured to include a free roller 201.

[0013] Next, the configuration of the apparatus 1 will be described. The apparatus 1 is disposed laterally with respect to the conveying direction of the workpiece 100 by the conveying unit 200. The apparatus 1 includes a housing 2 that houses each part of the apparatus 1, and a display unit 3a and an operation unit 3b provided on a side surface of the housing 2. The display unit 3a displays the control content of the apparatus 1. The operation unit 3b is a part that is operated by a user to set the control content of the apparatus 1 or to instruct the operation of the apparatus 1.

[0014] The apparatus 1 includes a suction unit 4, a measurement unit 5, a cutting unit 6, a height measurement unit 7, and a recovery unit 8. The suction unit 4 sucks the film 103 to form a space between the article 102 or the pallet 101 and the film 103. Specifically, as shown in FIGS. 1, 3, 4, and 7, the suction unit 4 includes a suction pad 9 as a suction part, a shaft 10 connected to the suction pad 9, a shaft support part 11 that supports the shaft 10, a shaft clamp 12 as a switching part, a first spring fixing part 13, a second spring fixing part 14, and a spring 15 as a suction biasing part. Note that FIGS. 4 and FIGS. 5 and 6 described later omit the illustration of the side plate of the housing 2 and also omit the illustration of some configurations such as the recovery unit 8.

[0015] The suction pad 9 contacts the film 103 which is the suction target, and the film 103 is suctioned by reducing the pressure inside the pad 9 while in contact with the film 103. The suction pad 9 faces in the horizontal direction and is provided so as to be movable in the horizontal direction. Here, the direction in which the suction pad 9, the measurement roller 20 or the cutter 36 described later approaches the side surface of the workpiece 100 is defined as the forward direction, and the direction away from the side surface of the workpiece 100 is defined as the backward direction. The direction perpendicular to both the first direction (the direction intersecting the side surface of the workpiece 100) which is the forward or backward direction and the vertical direction (the second direction) perpendicular to the first direction is defined as the left-right direction (the third direction). As shown in FIG. 3, the suction pads 9 are provided in two rows at intervals in the left-right direction. A plurality (specifically, four) of the suction pads 9a in the first row are provided at intervals in the vertical direction. Similarly, a plurality (specifically, four) of the suction pads 9b in the second row are provided at intervals in the vertical direction. The suction pads 9a and the suction pads 9b are provided in the same number. Also, the suction pads 9a and the suction pads 9b are provided at the same height position.

[0016] Also, as shown in FIG. 4, the lowermost suction pad 9 faces the side surface of the pallet 101 in a state where the apparatus 1 and the workpiece 100 face each other. The uppermost suction pad 9 faces near the upper end of the side surface of the article 102. The intermediate suction pad 9 faces the middle part of the side surface of the article 102.

[0017] As shown in Figure 7, the shaft 10 extends horizontally (left-right direction in Figure 7, in the direction of forward or backward movement of the suction pad 9). The suction pad 9 is connected to one end of the shaft 10. The shaft support 11 supports the shaft 10 so that it can move in its axial direction, through which the shaft 10 is inserted. The shaft clamp 12 switches between an permitted state, which allows the horizontal relative movement of the shaft 10 to the shaft clamp 12, and a prohibited state, based on air pressure, when the shaft 10 is inserted. For example, when air is supplied to the shaft clamp 12, it enters the permitted state, and when the air supply is stopped, it enters the prohibited state. In the permitted state, the biasing force of the spring 15 is allowed to act on the suction pad 9. In the prohibited state, the biasing force of the spring 15 is prohibited from acting on the suction pad 9.

[0018] The first spring fixing part 13 is fixed to the shaft support part 11. One end of the plate-shaped spring 15 is connected to the first spring fixing part 13, and that end is wound up. The second spring fixing part 14 is fixed to the end of the shaft 10 opposite to the end to which the suction pad 9 is connected. The second spring fixing part 14 is connected to the end of the spring 15 opposite to the end to which it is connected to the first spring fixing part 13.

[0019] The spring 15 is a constant-load leaf spring. The spring 15 is a suction biasing part that biases the suction pad 9 in a direction that presses it against the side surface (film 103) of the workpiece 100 when the suction pad 9 is in contact with the side surface (film 103). The spring 15 is connected to the shaft 10 and the shaft support part 11 via spring fixing parts 13 and 14. As the spring 15 is pulled out from the first spring fixing part 13, it biases the suction pad 9 via the shaft 10. The load (biasing force) of the spring 15 is constant regardless of the amount it is pulled out from the first spring fixing part 13.

[0020] The suction unit 4 includes a suction drive unit that moves the portion shown in Figure 7 in the forward direction (left direction in Figure 7) or backward direction (right direction in Figure 7) in the horizontal direction. Specifically, as shown in Figure 4, the suction unit 4 includes a cylinder 16 as the suction drive unit and a connecting portion 18 that is connected to the tip of the rod 17 of the cylinder 16 and the shaft support portion 11 described above.

[0021] The cylinder 16 includes a movable rod 17, and the axis of the rod 17 is positioned so as to face left-right in Figure 4 (the forward and backward movement direction of the suction pad 9). The cylinder 16 moves the rod 17 forward or backward in left-right in Figure 4 based on air pressure. The cylinder 16 is a robotic cylinder in which the amount of protrusion of the rod 17 from the cylinder body can be adjusted.

[0022] The cylinder 16 and connecting portion 18 are provided for each of the first row of suction pads 9a and the second row of suction pads 9b shown in Figure 3. That is, the cylinder 16 includes a first cylinder for simultaneously moving all (4) of the first row of suction pads 9a and a second cylinder for simultaneously moving all (4) of the second row of suction pads 9b. The first cylinder 16 is a common cylinder for all of the first row of suction pads 9a. The second cylinder 16 is a common cylinder for all of the second row of suction pads 9b. The first cylinder 16 and the second cylinder 16 are arranged in the same direction as the arrangement direction of the rows of suction pads 9a and rows of suction pads 9b (i.e., the left-right direction in Figure 3).

[0023] The connecting portion 18 includes a first connecting portion connected to the shaft support portion 11 of each suction pad 9a in the first row, and a second connecting portion connected to the shaft support portion 11 of each suction pad 9b in the second row. The first connecting portion 18 is connected to the rod 17 of the first cylinder 16. The second connecting portion 18 is connected to the rod 17 of the second cylinder 16. Note that the cylinder 16 and connecting portion 18 do not necessarily have to be provided for each suction pad 9a, 9b; that is, a common cylinder and connecting portion may be used for all (8) suction pads 9 (the four suction pads 9a in the first row and the four suction pads 9b in the second row). Note that in Figure 4 and the later Figures 5 and 6, the first connecting portion 18 is shown, and the second connecting portion 18 is not shown.

[0024] When the first cylinder 16 is driven, all the suction pads 9a in the first row move simultaneously horizontally via the first connecting portion 18 and portions 10-15 shown in Figure 7. When the second cylinder 16 is driven, all the suction pads 9b in the second row move simultaneously horizontally via the second connecting portion 18 and portions 10-15 shown in Figure 7. The suction unit 4 corresponds to the space forming unit of this disclosure.

[0025] The measuring unit 5 moves vertically and measures the horizontal position of one side of the workpiece 100 (specifically, the side facing the measuring unit 5 and the cutting unit 6) corresponding to each vertical position. The measuring unit 5 (excluding the vertical drive unit 45 (see Figure 4) described later) is located below the cutting unit 6 (excluding the vertical drive unit 45). As shown in Figure 8, the measuring unit 5 includes a measuring roller 20, a roller support unit 21, a shaft 22, a shaft support unit 23, a first spring fixing unit 24, a second spring fixing unit 25, a spring 26, a drive unit 27, and a position detection unit 30.

[0026] As shown in Figure 3, the measuring roller 20 is positioned midway between the first row of suction pads 9a and the second row of suction pads 9b in the left-right direction. The measuring roller 20 is positioned in the same location as the cutter 36, which will be described later, in the left-right direction of Figure 3. The measuring roller 20 is also positioned below the cutter 36. The measuring roller 20 has an axis oriented in the left-right direction of Figure 3 and is a roller that can rotate around that axis. The measuring roller 20 is supported by the roller support section 21.

[0027] The shaft 22 extends horizontally (left-right direction in Figure 8, and in the forward or backward direction of the measuring roller 20). A roller support portion 21 is connected to one end of the shaft 22. The shaft support portion 23 supports the shaft 22 so that it can move in its axial direction, through which the shaft 22 is inserted.

[0028] The first spring fixing part 24 is fixed to the shaft support part 23. One end of the plate-shaped spring 26 is connected to the first spring fixing part 24, and that end is wound up. The second spring fixing part 25 is fixed to the end of the shaft 22 opposite to the end to which the roller support part 21 is connected. The second spring fixing part 25 is connected to the end of the spring 26 opposite to the end to which the first spring fixing part 24 is connected.

[0029] The spring 26 is a constant-load leaf spring. The spring 26 is a measuring biasing part that biases the measuring roller 20 in a direction that presses it against the side surface (film 103) of the workpiece 100 when the measuring roller 20 is in contact with the side surface. The spring 26 is connected to the shaft 22 and the shaft support part 23 via spring fixing parts 24 and 25. As the spring 26 is pulled out from the first spring fixing part 24, it biases the measuring roller 20 via the shaft 22 and the roller support part 21. The load (biasing force) of the spring 26 is constant regardless of the amount the spring 26 is pulled out from the first spring fixing part 24.

[0030] The drive unit 27 comprises a guide 28 and a movable part 29 that is provided to move linearly along the guide 28. The drive unit 27 is, for example, a rodless air cylinder. The guide 28 is fixed to the lower surface of a support plate 34 provided between the measuring unit 5 and the cutting unit 6, and guides the movable part 29 in the left-right direction in Figure 8. The movable part 29 moves based on the air supplied to the drive unit 27. The movable part 29 is connected to the shaft support part 23 via a plate member 33. As the movable part 29 moves in the left-right direction in Figure 8, the parts 20-26, 30, and 33 below the movable part 29 also move in the left-right direction in Figure 8. Note that the drive unit 27 corresponds to the roller drive unit of this disclosure.

[0031] The position detection unit 30 detects the horizontal position of the measuring roller 20 when it is in contact with the side surface of the workpiece 100. The position detection unit 30 is, for example, a magnetic scale. That is, the position detection unit 30 includes an elongated scale 31 and a sensor head 32. The scale 31 is provided so that its longitudinal direction is oriented in the left-right direction in Figure 8. One end of the scale 31 in the longitudinal direction is fixed to the roller support 21. The other end of the scale 31 in the longitudinal direction is fixed to the shaft 22 or the second spring fixing part 25. Position information corresponding to each position is recorded magnetically at each position along the longitudinal direction of the scale 31.

[0032] The sensor head 32 is fixed to the plate member 33 and is positioned facing the scale 31, so as to be able to move horizontally relative to the scale 31. The sensor head 32 detects the position information recorded on the scale 31 and outputs a signal of that position information.

[0033] The measuring unit 5 is equipped with an up-and-down drive unit 45 (see Figure 4) that moves each of the parts 20 to 33 shown in Figure 8 in the vertical direction. The up-and-down drive unit 45 is a common drive unit between the measuring unit 5 and the cutting unit 6 described later. That is, the up-and-down drive unit 45 moves the measuring unit 5 and the cutting unit 6 simultaneously, in the same direction, and at the same speed.

[0034] As shown in Figure 4, the vertical drive unit 45 comprises a drive motor 46, a vertically movable part 47, a rotating body 48 (e.g., a gear), a transmission member 49, a guide 50, and a cam follower 51. The drive motor 46 is located above the guide 50. The rotating body 48 includes an upper rotating body located near the drive motor 46 and a lower rotating body (not shown) located near the lower end of the device 1.

[0035] The vertically movable part 47 is a belt or chain wrapped around the upper and lower rotating bodies 48. The vertically movable part 47 has two parts 47a and 47b that extend linearly in the vertical direction between the upper and lower rotating bodies 48. One part 47a is fixed via a bracket 54 to a support plate 34 (see Figure 8) that supports the parts of the measuring unit 5 and the cutting unit 6 other than the vertical drive part 45.

[0036] The transmission member 49 is a component that transmits the rotation of the drive motor 46 to the upper rotating body 48, causing the upper rotating body 48 to rotate. The transmission member 49 is a belt or chain that is wrapped around the rotating body connected to the rotation shaft of the drive motor 46 and the upper rotating body 48.

[0037] Guide 50 is an elongated member extending in the vertical direction, and is a member that guides the vertical movement of the measuring unit 5 and the cutting unit 6. Multiple guides 50 are provided; specifically, a total of four guides are provided: two rows spaced apart in the left-right direction in Figure 4, and two rows spaced apart in the direction perpendicular to the plane of the paper in Figure 4.

[0038] The cam follower 51 is provided to be movable vertically along the guide 50. Specifically, the cam follower 51 includes a rotatable roller, which is positioned to contact the side of the guide 50. A cam follower 51 is provided for each guide 50. The cam follower 51 has a first cam follower 52 and a second cam follower 53, as shown in Figure 8. The first cam follower 52 includes a roller that contacts one side of the guide 50 (specifically, the side facing left and right in Figure 4). The second cam follower 53 includes a roller that contacts the other side of the guide 50 (specifically, the side facing perpendicular to the plane of the paper in Figure 4). Each cam follower 51 is fixed to a support plate 34 as shown in Figure 8.

[0039] When the rotation shaft of the drive motor 46 rotates in the first rotational direction, one portion 47a of the vertically movable part 47 moves downward via the transmission member 49 and the upper rotating body 48. Consequently, the support plate 34 (see Figure 8) fixed to portion 47a and the measuring unit 5 and cutting unit 6 supported by it move downward. When the rotation shaft of the drive motor 46 rotates in the second rotational direction, opposite to the first rotational direction, one portion 47a of the vertically movable part 47 moves upward via the transmission member 49 and the upper rotating body 48. Consequently, the measuring unit 5 and cutting unit 6 move upward.

[0040] The cutting unit 6 is a unit that cuts the film 103 in the vertical direction. Specifically, as shown in Figure 8, the cutting unit 6 comprises a movable part 35 that is movable in the left-right direction in Figure 8, a cutter 36 provided at the tip of the movable part 35, a support part 37 that supports the movable part 35 so that it can move in the left-right direction in Figure 8, a drive motor 38, and a transmission member 39. The cutter 36 is the part that cuts the film 103 and can be a hot air cutter, an ultrasonic cutter, a heat cutter, etc. As shown in Figure 3, the cutter 36 is provided at an intermediate position between the first row of suction pads 9a and the second row of suction pads 9b in the left-right direction.

[0041] The support unit 37 receives driving force from the drive motor 38 and moves the movable unit 35. Specifically, the support unit 37 is composed of, for example, a ball screw that converts the rotational motion of the drive motor 38 into linear motion. The support unit 37 is fixed to the upper surface of a support plate 34 provided between the measuring unit 5 and the cutting unit 6. The drive motor 38 supplies the driving force to move the movable unit 35. The transmission member 39 is connected to the rotation shaft of the drive motor 38 and the screw shaft of the movable unit 35, and transmits the rotation of the drive motor 38 to the screw shaft.

[0042] When the rotation axis of the drive motor 38 rotates in the first rotational direction, the movable part 35 and the cutter 36 move to the left in Figure 8 (towards the side of the workpiece 100) via the transmission member 39 and the support part 37. When the rotation axis of the drive motor 38 rotates in the second rotational direction, which is opposite to the first rotational direction, the movable part 35 and the cutter 36 move to the right in Figure 8 (away from the side of the workpiece 100).

[0043] Furthermore, the cutting unit 6 includes the aforementioned vertical drive unit 45 (see Figure 4) which moves each of the parts 34 to 39 shown in Figure 8 in the vertical direction. Note that the drive motor 38 and the vertical drive unit 45 correspond to the cutter drive unit of this disclosure.

[0044] The height measuring unit 7 shown in Figure 2 measures the height of the workpiece 100 placed in front of the device 1. The height measuring unit 7 is a non-contact sensor (e.g., an ultrasonic sensor) that outputs a signal corresponding to the vertical position of the upper surface of the workpiece 100 without making contact with the upper surface of the workpiece 100. The height measuring unit 7 is supported by a projection 55 that protrudes laterally from the housing 2 and is positioned opposite the upper surface of the workpiece 100.

[0045] The recovery unit 8 peels the film 103 cut by the cutting unit 6 from the pallet 101 and the article 102 and sends it to a predetermined recovery location. Specifically, as shown in Figures 1 and 3, the recovery unit 8 includes a suction pad 60, a pad support unit 61, a horizontal drive unit 62, a vertical drive unit 63, a drive support unit 64, a guide 65, a front-rear drive unit 66, and a position detection unit 67.

[0046] The suction pad 60 contacts the cut film 103, and the film 103 is adsorbed by the reduction of pressure inside the pad 60 while it is in contact with the film 103. Here, in Figure 3, the center line is defined as a virtual line L extending vertically, passing through the positions of the measuring roller 20 and cutter 36 in the left-right direction. Two suction pads 60 are provided. The two suction pads 60 are provided at the same height and symmetrical with respect to the center line L. That is, one suction pad 60 is provided to the left of the center line L. The other suction pad 60 is provided to the right of the center line L. In addition, the suction pads 60 are provided at a position further outward in the left-right direction of Figure 3 than the suction pad 9 of the suction unit 4.

[0047] A pad support section 61 is provided for each suction pad 60 and supports each suction pad 60.

[0048] Each pad support 61 is provided with a horizontal drive unit 62, which moves each pad support 61 in the left-right direction as shown in Figure 3. For example, it may be an air cylinder. Note that Figure 3 shows the state in which each suction pad 60 is closest to the center line L. Each horizontal drive unit 62 moves each pad support 61 in the left-right direction as shown in Figure 3 so as to change the spacing between each suction pad 60 between a predetermined minimum spacing (spacing shown in Figure 3) and a predetermined maximum spacing (not shown). Specifically, the horizontal drive unit 62 on the left side of Figure 3 moves the left suction pad 60 in the left-right direction between a first position shown in Figure 3 and a second position that is further to the left (away from the center line L) than the first position. The horizontal drive unit 62 on the right side of Figure 3 moves the right suction pad 60 in the left-right direction between a first position shown in Figure 3 and a second position that is further to the right (away from the center line L) than the first position. The minimum spacing is set to be the spacing between each suction pad 60 facing the side of the workpiece 100, in other words, a spacing smaller than the left-right width of the workpiece 100. The maximum spacing is set to be the spacing between each suction pad 60 that does not face the side of the workpiece 100, in other words, a spacing larger than the left-right width of the workpiece 100.

[0049] Each vertical drive unit 63 is provided for each horizontal drive unit 62 and moves each horizontal drive unit 62 in the vertical direction; for example, it is an air cylinder. The drive support unit 64 is provided so as to protrude to the left and right from the center line L shown in Figure 3 and supports each vertical drive unit 63. The guide 65 supports the drive support unit 64 and guides the movement of the drive support unit 64 and the parts 60-63 supported by it in the front-rear direction perpendicular to the plane of the paper in Figure 3. The guide 65 is composed of, for example, a ball screw that converts rotational motion into linear motion in the front-rear direction. The front-rear drive unit 66 is provided inside the housing 2 and supplies driving force to move the drive support unit 64 and the parts 60-63 supported by it in the front-rear direction along the guide 65. The front-rear drive unit 66 is, for example, a motor that rotates the screw shaft of the guide 65, which is composed of a ball screw.

[0050] The position detection unit 67 is positioned at the same height as the suction pad 60 and detects the horizontal position of the side surface of the workpiece 100 that the suction pad 60 is about to contact. The position detection unit 67 is a non-contact sensor (e.g., an ultrasonic sensor) that detects the distance between the position detection unit 67 and the side surface of the workpiece 100 without contacting the side surface of the workpiece 100.

[0051] As shown in Figure 2, the device 1 comprises a control unit 70 that controls each of the above-mentioned parts (each unit 4, 5, 6, 8, etc.) that constitute the device 1, and a storage unit 71 that stores various information. Furthermore, the device 1 includes a pump (not shown) that reduces the pressure inside the above-mentioned suction pads 9 and 60, an air control unit (not shown) that controls the supply of air to each air cylinder, and the like.

[0052] Next, the operation of the device 1 will be explained. Figure 9 shows an example flowchart of the film cutting process performed by the control unit 70. As a prerequisite for the process in Figure 9 to be performed, the workpiece 100 is transported to the front of the device 1 and positioned in front of the device 1 by the positioning unit 202 (see Figure 2).

[0053] When the process shown in Figure 9 begins, the control unit 70 instructs the height measuring unit 7 to measure the height position of the upper surface of the workpiece 100 (S1).

[0054] Next, the suction unit 4 is used to adsorb the film 103 on one side of the workpiece 100 facing the device 1 (S2). Specifically, the process shown in Figure 10 is performed. When the process in Figure 10 is initiated, first, as shown in Figure 5, each cylinder 16 is controlled to advance each suction pad 9 so that it contacts the side of the workpiece 100 (S11). In this case, the amount the rod 17 advances is greater than the distance between the suction pad 9 and the side of the workpiece 100 in its original position as shown in Figure 4. Also, when the rod 17 advances, the lock (prohibited state) of the shaft 10 by the shaft clamp 12 is released. That is, relative movement between the shaft 10 and the shaft support 11 and shaft clamp 12 is permitted.

[0055] As the rod 17 moves forward, the shaft support 11 connected to the rod 17, the shaft clamp 12, the first spring fixing part 13, the second spring fixing part 14, the spring 15, the shaft 10, and the suction pad 9, which are directly or indirectly connected to the shaft support 11 via the spring 15, also move forward. When the suction pad 9 contacts the side surface of the workpiece 100, the suction pad 9, the shaft 10, and the second spring fixing part 14 stop. Even after the suction pad 9, the shaft 10, and the second spring fixing part 14 have stopped, the rod 17 continues to move forward, and consequently, the shaft support 11, the shaft clamp 12, and the first spring fixing part 13 also continue to move forward. At this time, the first spring fixing part 13 moves forward relative to the stopped second spring fixing part 14, causing the spring 15 to stretch. As the spring 15 stretches, the suction pad 9 presses against the side surface of the workpiece 100 via the second spring fixing part 14 and the shaft 10. In other words, when the suction pad 9 is in contact with the side surface of the workpiece 100, the spring 15 biases the suction pad 9 in a direction that presses it against the side surface of the workpiece 100 as the shaft support portion 11 moves relative to the shaft 10.

[0056] Furthermore, in the example shown in Figure 5, there is a horizontal step between the side of the pallet 101 and the side of the item 102. Due to this step, the suction pad 9 that contacts the side of the pallet 101 via the film 103 and the suction pad 9 that contacts the side of the item 102 via the film 103 are in different horizontal positions.

[0057] Next, a pump (not shown) is activated to remove the air from each suction pad 9, thereby causing the film 103 to adhere to each suction pad 9 (S12).

[0058] Next, the shaft clamp 12 is activated to prevent relative movement of the shaft 10 with respect to the shaft clamp 12 and the shaft support 11 (S13).

[0059] Next, as shown in Figure 6, the rods 17 of each cylinder 16 are retracted to retract the suction pads 9 by a predetermined amount, thereby creating a space between the film 103 and the article 102 or pallet 101 (S14). At this time, since the shaft 10 is in a restricted state, it is possible to prevent the shaft 10 and the suction pads 9 from moving forward due to the force of the spring 15. In addition, the lowest suction pad 9 creates a space between the pallet 101 and the film 103. The remaining suction pads 9 create a space between the article 102 and the film 103. Furthermore, the first row of suction pads 9a and the second row of suction pads 9b also create the same space between them.

[0060] Returning to Figure 9, next, with a space formed between the film 103 and the article 102 or pallet 101, the measuring unit 5 is instructed to measure the horizontal position of one side of the workpiece 100 (the side of the workpiece 100 facing the device 1) at each vertical position (S3). Furthermore, the cutting unit 6 is instructed to start cutting the film 103 while the measuring unit 5 is operating, and to cut the film 103 vertically in accordance with the operation of the measuring unit 5 (S3). Specifically, the process shown in Figure 11 is performed. When moving to the process shown in Figure 11, first, the drive motor 46 of the vertical drive unit 45 (see Figure 4) is controlled to raise the measuring unit 5 and the cutting unit 6 (S21). At this time, the measuring unit 5 and the cutting unit 6 are raised so that the height position of the measuring roller 20 is the same as the height position of the workpiece 100 measured in step S1.

[0061] Next, the drive unit 27 of the measuring unit 5 shown in Figure 8 is controlled to advance the measuring roller 20 so that it contacts the side surface of the workpiece 100 (S22). At this time, the movable part 29 of the drive unit 27 is advanced to a predetermined maximum position. In this case, the amount of advancement of the movable part 29 is greater than the distance between the measuring roller 20 and the side surface of the workpiece 100 at its original position.

[0062] As the movable part 29 moves forward, the plate member 33, shaft support part 23, first spring fixing part 24, and sensor head 32 shown in Figure 8, which are directly or indirectly connected to the movable part 29, also move forward. The second spring fixing part 25, shaft 22, roller support part 21, measuring roller 20, and scale 31 are indirectly connected to the second spring fixing part 24 via the spring 26, and therefore move forward as the second spring fixing part 24 moves forward.

[0063] When the measuring roller 20 contacts the side surface of the workpiece 100, the measuring roller 20, roller support 21, shaft 22, second spring fixing part 25, and scale 31 stop. Even after these stop, the movable part 29 continues to move forward, and consequently, the plate member 33, shaft support 23, first spring fixing part 24, and sensor head 32 also continue to move forward. At this time, the first spring fixing part 24 moves forward relative to the stopped second spring fixing part 25, causing the spring 26 to stretch. As the spring 26 stretches, the measuring roller 20 is pressed against the side surface of the workpiece 100 via the second spring fixing part 25, shaft 22, and roller support 21. In other words, with the measuring roller 20 in contact with the side surface of the workpiece 100, the spring 26 biases the measuring roller 20 in a direction that presses it against the side surface of the workpiece 100 as the shaft support 23 moves relative to the shaft 22. In addition, in the portion of the side of the workpiece 100 that the measuring roller 20 is in contact with, the film 103 temporarily comes into contact with the side of the article 102 or pallet 101. However, in the portion of the side of the workpiece 100 that the measuring roller 20 is not in contact with, the suction unit 4 holds the film 103 in a state where a space is formed between the film 103 and the article 102 or pallet 101. Figure 12 shows the state in which the measuring roller 20 is in contact with the side of the workpiece 100 and is pressing the side of the workpiece 100 against it by the biasing force of the spring 26.

[0064] Next, the drive motor 46 of the vertical drive unit 45 (see Figure 4) is controlled to lower the measuring unit 5 and the cutting unit 6 while the measuring roller 20 is in contact with the side surface of the workpiece 100 (S23). During this lowering, the drive unit 27 of the measuring unit 5 is not operated, and the movable part 29 is held in its maximum forward position.

[0065] While the measuring unit 5 and the cutting unit 6 are descending, the sensor head 32 is made to sequentially read the position information recorded on the scale 31, and this position information is stored in the memory unit 71 (see Figure 2) in association with the vertical position (S24). This position information indicates the horizontal position of the measuring roller 20 and the side surface of the workpiece 100 that it contacts.

[0066] As the measuring roller 20 descends, it moves horizontally to follow the horizontal position of the side surface of the workpiece 100 based on the biasing force of the spring 26. That is, if the position of the side surface of the workpiece 100 changes in the direction of the measuring roller 20's advance, the measuring roller 20 also moves forward due to the biasing force of the spring 26. If the position of the side surface of the workpiece 100 changes in the direction of the measuring roller 20's retraction, the measuring roller 20 also moves backward against the biasing force of the spring 26.

[0067] While the measuring roller 20 is descending (in other words, while the lateral position of the workpiece 100 is being measured), the cutter 36 of the cutting unit 6 is made to cut the film 103 (S25). Figure 12 shows how the film 103 is being cut by the cutter 36 while the measuring roller 20 is measuring. Specifically, as the measuring roller 20 descends, the cutter 36 also descends, but while the cutter 36 is descending, the position of the cutter 36 in the horizontal direction is controlled according to the measurement results of step S24, specifically the lateral position of the workpiece 100 for each vertical position stored in the storage unit 71. For example, if the lateral position of the workpiece 100 changes to the left in Figure 12, the drive motor 38 of the cutting unit 6 is controlled to move the cutter 36 to the left in Figure 12. If the lateral position of the workpiece 100 changes to the right in Figure 12, the drive motor 38 is controlled to move the cutter 36 to the right in Figure 12. Furthermore, the position of the cutter 36 is controlled so that it does not come into contact with the side of the item 102 or the pallet 101.

[0068] Next, it is determined whether the measuring roller 20 or cutter 36 has moved to the lower end position preset by the operating unit 3b (see Figure 1) (S26). If it has not reached the lower end position (S26: No), the lowering, measuring, and cutting described above are continued (S23, S24, S25). If it has reached the lower end position (S26: Yes), the process shown in Figure 11 is terminated.

[0069] In the process shown in Figure 11, the measuring unit 5 measures the side position of the pallet 101 in addition to the side position of the article 102. The cutter 36 cuts the portion of the film 103 that covers the side of the article 102 in addition to the portion that covers the side of the pallet 101.

[0070] Returning to Figure 9, the next step is to have the recovery unit 8 recover the cut film 103 (S4). Specifically, first, the drive units 62, 63, and 66 of the recovery unit 8 are controlled to position each suction pad 60 of the recovery unit 8 against one side of the workpiece 100 (the side facing the device 1), and then advance by an amount according to the detection result of the position detection unit 67 to bring it into contact with the cut film 103. At this time, one suction pad 60 is brought into contact with one part of the film 103 that has been separated into two parts by cutting. The other suction pad 60 is brought into contact with the other part of the film 103. Next, the air inside each suction pad 60 is removed to cause the film 103 to adhere to each suction pad 60. Next, the drive units 62, 63, and 66 of the recovery unit 8 are controlled to peel the film 103 from the article 102 and pallet 101 and send it to a predetermined recovery location. After that, the process shown in Figure 9 is completed.

[0071] The effects of this embodiment will now be explained. Since the measuring roller 20 and cutter 36 are moved horizontally to follow the horizontal position of the side surface of the workpiece 100, the film 103 can be cut vertically even if the horizontal position of the side surface of the workpiece 100 changes along the vertical direction. In addition, the portion of the film 103 that covers the pallet 101 is also cut, making it easier to recover the film 103 afterward.

[0072] Furthermore, since the suction pad 9 creates a space between the film 103 and the article 102 or pallet 101, the film 103 is cut in this state, thus preventing damage to the article 102 or pallet 101 from the cutter 36. Also, since the film 103 is cut while the measurement unit 5 is measuring, the time required to complete the cutting of the film 103 can be shortened.

[0073] Furthermore, in the suction unit 4, multiple (4) suction pads 9 are connected to one cylinder 16. In other words, since one cylinder is not provided for each suction pad 9, the configuration of the suction unit 4 can be simplified. Also, by utilizing the biasing force of the spring 15, the amount of forward movement of the rod 17 of the cylinder 16 can be kept constant, while the amount of forward movement of each suction pad 9 can be changed according to the side position of the workpiece 100. In addition, the biasing force of the spring 15 allows the suction pads 9 to adhere tightly to the side of the workpiece 100.

[0074] In the measuring unit 5, when the measuring roller 20 is moved vertically while in contact with the side surface of the workpiece 100, the measuring roller 20 is made to follow the side surface position of the workpiece 100 based on the biasing force of the spring 26, thus simplifying the control required for this tracking.

[0075] This disclosure is not limited to the above embodiments, and various modifications are possible. For example, in the above embodiment, an example is shown in which the cutting of the film 103 is started while the measuring unit 5 is measuring, but the cutting of the film 103 may be started after the measurement by the measuring unit 5 is completed. In this case, for example, the measurement by the measuring unit 5 is started from the lower end of the side surface of the workpiece 100, and the measurement is performed while moving the measuring roller 20 upward. After moving the measuring roller 20 to the upper end of the workpiece 100, the cutter 36 is lowered to cut the film 103.

[0076] Furthermore, the lateral position of the workpiece 100 along the vertical direction may be measured using a non-contact sensor such as an ultrasonic sensor.

[0077] Furthermore, multiple measuring units 5 and cutting units 6 may be provided along the cutting direction (i.e., vertical direction) of the film 103. In this case, multiple measuring units share the task of measuring the position of the workpiece side along the vertical direction. Also, multiple cutting units share the task of cutting the film in the vertical direction.

[0078] Furthermore, although the above embodiment shows an example in which the film 103 covering the side surface of the workpiece 100 is cut in the vertical direction, the cutting direction of the film 103 may be in a direction other than vertical, and if the film 103 also covers the top surface of the workpiece 100, the film 103 covering that top surface may be cut. In other words, the film cutting apparatus of this disclosure may be configured as follows.

[0079] (1) A device for cutting a film in a workpiece which includes an article and a film that encloses the outer periphery of the article, The direction in which the workpiece surface (for example, the upper surface of the workpiece) is approached or moved away from (in other words, the direction intersecting the workpiece surface) is called the first direction (for example, the vertical direction), and the direction perpendicular to the first direction is called the second direction (for example, the horizontal direction). A measuring unit that moves in the second direction and measures the position of the surface in the first direction corresponding to each position in the second direction, A cutter for cutting the aforementioned film, A film cutting apparatus comprising: a cutter drive unit that moves the cutter in the second direction and controls the position of the cutter in the first direction according to the measurement result from the measuring unit.

[0080] In (1) above, the measuring unit is Measuring roller and A first drive unit that brings the measuring roller into contact with the surface (e.g., top surface) of the workpiece, A measuring biasing unit that biases the measuring roller in a direction that presses it against the surface while it is in contact with the surface, A second drive unit moves the measuring roller in the second direction while it is in contact with the surface, The system includes a position detection unit that outputs a signal corresponding to the position of the measuring roller in the first direction, As the measuring roller moves in the second direction, it may move in the first direction, following the position of the surface in the first direction based on the biasing force of the measuring biasing unit.

[0081] Furthermore, in (1) or (2) above, the film cutting device includes an adsorption unit that adsorbs the film and forms a space between the film and the article, The cutter cuts the film while the space is formed, The adsorption unit is A suction portion is provided so as to be movable in the first direction and contacts the film to adsorb the film, A shaft extending in the first direction is connected to the adsorption part, A shaft support portion that supports the shaft so as to be movable in the first direction, A shaft drive unit that drives the shaft support in the first direction, A suction biasing unit is connected to the shaft and the shaft support, and generates a biasing force in the first direction as the shaft support and the shaft move relative to each other in the first direction. The system includes a shaft clamp (switching unit) that switches between an permitted state in which relative movement between the shaft and the shaft support is allowed and a prohibited state in which the relative movement is prohibited. In the permitted state, the shaft drive unit moves the shaft support unit forward so that the biasing force of the suction biasing unit acts on the suction unit while the suction unit is in contact with the film. The suction biasing portion, while in contact with the film, biases the suction portion in a direction that presses it against the film as the shaft support portion moves relative to the shaft. The shaft clamp is switched to the prohibited state after the forward movement. The shaft drive unit may retract the shaft support unit after the forward movement, when the suction unit is in a state where it has attached the film and the prohibition state is in place, in order to form the space.

[0082] Furthermore, the film cutting method of this disclosure may be configured as follows. A method for cutting a film in a workpiece that includes an article and a film that encloses the outer periphery of the article, The direction in which the workpiece approaches or moves away from its surface is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction. A space-forming step of forming a space between the film and the article, With the space formed, the measurement step involves sequentially measuring the position of the workpiece surface in the first direction along the second direction, A cutting step in which, with the space formed, the cutter is moved along the second direction in accordance with the measurement of the measurement step, and the cutter is moved in the first direction according to the measurement result of the measurement step, and the film is cut with the cutter, A film cutting method comprising the following features. [Explanation of Symbols]

[0083] 1. Film cutting device 4 Adsorption Units 5. Measurement Unit 6 Cutting Units 36 Cutter 38. Horizontal drive motor for cutter 45 Up / Down Drive Unit 100 Work 101 Palette 102 Goods 103 Stretch film

Claims

1. A 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 of the side surface of the workpiece corresponding to each position in the vertical direction, A cutter for cutting the aforementioned film, The system includes a cutter drive unit that moves the cutter vertically and controls the position of the cutter horizontally according to the measurement results from the measuring unit, The measuring unit measures the lateral position of the pallet in addition to the lateral position of the article. The cutter cuts not only the portion of the film that covers the side of the article, but also the portion that covers the side of the pallet. Film cutting device.

2. The aforementioned measuring unit is Measuring roller and A roller drive unit that moves the measuring roller to contact the side surface of the workpiece, A measuring biasing unit that biases the measuring roller in a direction that presses it against the side surface while it is in contact with the side surface, A vertical drive unit that moves the measuring roller in the vertical direction while in contact with the side surface, The system includes a position detection unit that outputs a signal corresponding to the horizontal position of the measuring roller, The film cutting apparatus according to claim 1, wherein the measuring roller moves horizontally in accordance with the horizontal position of the side surface based on the biasing force of the measuring biasing unit as it moves vertically.

3. The unit comprises a space-forming unit that forms a space between the film and the article or the pallet, The measuring unit measures the position of the side surface while the space is formed, The film cutting apparatus according to claim 1 or 2, wherein the cutter starts cutting the film while the measuring unit is operating with the space formed, and cuts the film in accordance with the operation of the measuring unit.

4. The unit comprises an adsorption unit that adsorbs the film to form a space between the film and the article or the pallet, The cutter cuts the film while the space is formed, The adsorption unit is Adhesive pads and A suction drive unit for moving the aforementioned suction pad, The suction pad is biased in a direction that presses it against the side surface while in contact with the side surface, The system includes a switching unit that switches between an permitted state, which allows the biasing force from the suction biasing unit to act on the suction pad, and a prohibited state, which prohibits the biasing force from acting on the suction pad. The switching unit switches from the permitted state to the prohibited state after the suction pad has adsorbed the film. The film cutting apparatus according to claim 1 or 2, wherein the suction drive unit advances the suction pad so that it contacts the side surface, and then retracts the suction pad to form the space when the suction pad is adsorbing the film and in the prohibited state.

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