Bag removal device and bag removal method

Abstract

To prevent a bag from being damaged while being taken out.SOLUTION: A bag take-out device 30 for taking out a predetermined number of bags 110 from a bag stacked body 100 including the multiple bags 110 stacked in a vertical direction dv, includes : a holding part 40 that holds the predetermined number of bags 110; and a clearance forming part 60 that is formed in a separate body from the holding part 40 and contacts the bag stacked body 100 to form a clearance 115 between two bags 110 neighboring in the vertical direction dv in the bag stacked body 100.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a bag dispensing device and a bag dispensing method. [Background technology]

[0002] Conventionally, a bag removal device has been used that removes a predetermined number of bags from a bag stack in which a plurality of empty bags are stacked, and supplies the bags to a bag processing machine such as a bag filling and packaging machine. As an example, empty bags are delivered from an empty bag manufacturer in a state in which a plurality of empty bags are stacked and contained in a cardboard box or the like. The bag removal device removes a predetermined number of bags directly from the bag stack inside the cardboard box, or from a bag stack that has been removed from the cardboard box and placed in a predetermined location. Patent Document 1 discloses such a bag removal device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-117310 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional bag removal devices, when removing bags from a bag stack, parts of the bag removal device come into contact with and rub against the bags, which can cause scratches on the outer surface of the bags. Such scratches not only impair the appearance of the bagged product, but also can cause the bags to tear through the scratches and leak their contents if an external force, such as pressure, is applied to the bags. Therefore, bag removal devices are required to remove bags without damaging them.

[0005] The present invention has been made in consideration of the above points, and has an object to provide a bag dispensing device that can prevent damage to bags when the bags are dispensed. [Means for solving the problem]

[0006] The bag removal device according to the present invention comprises: A bag dispensing device that dispenses a predetermined number of bags from a bag stack including a plurality of bags stacked in a vertical direction, a holding section for holding the predetermined number of bags; The bag stack further includes a gap forming portion that is configured separately from the holding portion and that contacts the bag stack to form a gap between two bags that are adjacent in the vertical direction in the bag stack.

[0007] In the bag dispensing device according to the present invention, Further comprising a control unit, The control unit The gap forming portion is moved to position a tip end portion of the gap forming portion at a height that is a predetermined distance lower than the upper surface of the bag stack, The gap forming portion is moved so that the gap forming portion comes into contact with the bag stack, The gap forming unit is moved to form the gap between two of the bags adjacent to each other in the vertical direction in the bag stack. A part of the holding portion is inserted into the gap, The holding portion holds the bag located above the gap, The holding section may be moved to control the movement of the bags held by the holding section from the stack of bags.

[0008] In the bag dispensing device according to the present invention, the holding section has a pair of clamping members that clamp the predetermined number of bags, The control unit may cause one of the pair of clamping members to enter the gap when the gap forming unit has formed the gap and is stopped.

[0009] In the bag dispensing device according to the present invention, The control unit may move the gap forming unit so that the tip portion enters the bag stack and moves upward, thereby forming the gap.

[0010] In the bag dispensing device according to the present invention, The gap forming portion is a contact member that can contact the bag stack; and a biasing member that biases the contact member toward the bag stack.

[0011] In the bag dispensing device according to the present invention, The biasing member may bias the contact member along a horizontal direction.

[0012] The bag removal method according to the present invention comprises the steps of: A bag removal method for removing a predetermined number of bags from a bag stack including a plurality of bags stacked in a vertical direction, using a bag removal device including a holding section that holds a predetermined number of bags and a gap forming section that is configured separately from the holding section, comprising: a step of moving the gap forming portion to position a tip end of the gap forming portion at a height that is lower by a predetermined distance than an upper surface of the bag stack; a step of moving the gap forming portion so that the gap forming portion comes into contact with the bag stack; a step of moving the gap forming unit to form a gap between two adjacent bags in the stack of bags in the vertical direction; inserting a portion of the holding portion into the gap; a step of holding the bag located above the gap with the holding portion; and removing the bag held by the holding portion from the bag stack. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a bag dispensing device that can prevent damage to bags when the bags are dispensed. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram for explaining one embodiment of the present invention, and is a side view showing a bag supplying device to which a bag dispensing device is assembled. [Figure 2] FIG. 2 is a side view showing the bag dispensing device of FIG. [Figure 3] 3 is a front view showing the bag dispensing device of FIG. 1. FIG. [Figure 4] FIG. 4 is a diagram illustrating a bag removal method using the bag removal device. [Figure 5] FIG. 5 is a diagram illustrating a bag removal method using the bag removal device. [Figure 6] FIG. 6 is a diagram illustrating a bag removal method using the bag removal device. [Figure 7] FIG. 7 is a diagram illustrating a bag removal method using the bag removal device. [Figure 8] FIG. 8 is a diagram illustrating a bag removal method using the bag removal device. [Figure 9] FIG. 9 is a diagram illustrating a bag removal method using the bag removal device. [Figure 10] FIG. 10 is a diagram illustrating a bag removal method using the bag removal device. [Figure 11] FIG. 11 is a side view showing a modified example of the bag dispensing device. [Figure 12] FIG. 12 is a diagram illustrating a bag removal method using the bag removal device of FIG. [Figure 13] FIG. 13 is a diagram illustrating a bag removal method using the bag removal device of FIG. [Figure 14] FIG. 14 is a side view showing another modified example of the bag dispensing device. [Figure 15] 15 is an enlarged view of the gap forming portion of the bag dispensing device of FIG. 14. FIG. [Figure 16] 16 is an enlarged view of the gap forming portion of the bag dispensing device of FIG. [Figure 17] FIG. 17 is a diagram illustrating a bag removal method using the bag removal device of FIG. [Figure 18] FIG. 18 is a diagram illustrating a bag removal method using the bag removal device of FIG. [Figure 19] FIG. 19 is a diagram illustrating a bag removal method using the bag removal device of FIG. [Figure 20]FIG. 20 is a diagram illustrating a bag removal method using the bag removal device of FIG. [Figure 21] FIG. 21 is a diagram illustrating a bag removal method using the bag removal device of FIG. [Figure 22] FIG. 22 is a diagram illustrating a bag removal method using the bag removal device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment of the present invention will now be described with reference to the drawings. Fig. 1 is a diagram for explaining this embodiment, and is a side view showing a bag supplying device 10 to which a bag dispensing device 30 is attached.

[0016] The bag supplying device 10 of this embodiment is a device that supplies bags to a bag processing machine such as a bag filling and packaging machine. The bag supplying device 10 includes a movement mechanism 20 and a bag removal device 30. The bag removal device 30 is a device that removes a predetermined number of bags 110 from a bag stack 100. The bag removal device 30 is configured to be movable by the movement mechanism 20, and can move the bags 110 removed from the bag stack 100 to a bag supply section of the bag processing machine. However, the bag removal device 30 is not limited to this, and can be used for various purposes, such as removing a predetermined number of bags 110 from the bag stack 100 and moving them to another location.

[0017] Referring to FIG. 4, the bag stack 100 of this embodiment will be described. In this embodiment, a plurality of bags 110 are stacked in the vertical direction dv to form the bag stack 100. The bags 110 may be empty bags. The bag 110 has, for example, a first sheet constituting one side and a second sheet constituting the other side joined together at their edges, and has a generally planar shape. The specific shape of the bag 110 is not particularly limited. For example, the bag 110 may have a folded portion or the like constituting a bottom or additional side between the edge of the first sheet and the edge of the second sheet. Furthermore, a spout or the like may be attached to the opening of the bag 110 for filling or pouring contents into or from the bag 110. The bags 110 are stacked such that the extension direction of their planar shapes is generally aligned with the horizontal direction. The bags 110 are stacked such that at least a portion of each bag 110 overlaps with each other. The bags 110 may also be stacked such that their entirety overlaps with each other. The bag stack 100 may also be formed by stacking bag bundles, each of which is a bundle of a predetermined number of bags 110. That is, the bag stack 100 may include a plurality of bag bundles stacked in the vertical direction dv. The bag stack 100 is held by a stack holder 120. The stack holder 120 has a bottom 122 and a wall 124. The bag stack 100 is placed on the bottom 122. In the illustrated example, one edge of the bag 110 included in the bag stack 100 is in contact with the wall 124.

[0018] The movement mechanism 20 is a mechanism for moving the bag dispensing device 30. In the example shown in FIG. 1 , the movement mechanism 20 is configured as an articulated robot and includes multiple arms 22 and multiple joints 24 that swingably connect adjacent arms 22 to each other. An orientation adjustment mechanism 26 is attached to the arm 22 located at the distal end. The arm 22 located at the proximal end is supported by a base 15. Each joint 24 and the base 15 are provided with a drive device such as a servo motor. The drive device provided at each joint 24 can adjust the angle between adjacent arms 22. The drive device provided at the base 15 can rotate the movement mechanism 20 around a pivot axis Ax1 that is parallel to the vertical direction dv. These drive devices are driven under the control of a movement control unit, causing the movement mechanism 20 to move the holder 40. Note that the configuration of the movement mechanism 20 is not limited to the example shown in the figure. For example, the whole or part of the moving mechanism 20 may be configured by another articulated robot (for example, another horizontal articulated robot (SCARA robot)), a parallel link robot, or an orthogonal robot.

[0019] Bag takeout device 30 is attached to orientation adjustment mechanism 26, and the orientation of bag takeout device 30 can be changed under the control of control unit 80. The illustrated orientation adjustment mechanism 26 includes a rotating body. This rotating body is fixedly attached to bag takeout device 30 and rotates integrally with bag takeout device 30. On the other hand, this rotating body is attached to movement mechanism 20 (particularly arm 22 located at the tip side) so that it can rotate about pivot axis Ax2. By rotating the rotating body of orientation adjustment mechanism 26 under the control of control unit 80, bag takeout device 30 can be rotated without rotating movement mechanism 20, and the orientation of bag takeout device 30 can be changed.

[0020] Fig. 2 is a side view showing bag removal device 30, and Fig. 3 is a front view showing bag removal device 30. In particular, Fig. 3 is a view seen along the arrow marked III in Fig. 2.

[0021] The bag takeout device 30 includes a holding unit 40, a gap forming unit 60, a detection unit 70, and a control unit 80. In the illustrated example, the bag takeout device 30 further includes a mounting bracket 32 ​​for mounting the bag takeout device 30 to the movement mechanism 20, a holding unit support bracket 34 for supporting the holding unit 40, a gap forming unit support bracket 36 for supporting the gap forming unit 60, and a detection unit support bracket 38 for supporting the detection unit 70. The mounting bracket 32 ​​is fixedly attached to the tip of the movement mechanism 20, particularly to the orientation adjustment mechanism 26. That is, when the rotating body of the orientation adjustment mechanism 26 rotates, the mounting bracket 32 ​​also rotates together with the rotating body. The holding unit support bracket 34 and the gap forming unit support bracket 36 are attached to the mounting bracket 32 ​​on the side opposite the movement mechanism 20. Furthermore, a detection unit support bracket 38 is attached to the mounting bracket 32 ​​on the side facing the movement mechanism 20.

[0022] The holding unit 40 includes a pair of clamping members 50, an opening / closing drive unit 56 that drives the pair of clamping members 50 to open and close, and an advancing / retreating drive unit 42 that drives the clamping members 50 to move forward and backward. The holding unit 40 holds a predetermined number of bags 110 included in the bag stack 100 using the pair of clamping members 50. Specifically, the predetermined number of bags 110 are sandwiched between the pair of clamping members 50, and the tips of the pair of clamping members 50 are brought close to each other to close the pair of clamping members 50, thereby holding the predetermined number of bags 110.

[0023] The pair of clamping members 50 includes a first clamping member 50a located relatively above and a second clamping member 50b located relatively below. The advance / retract drive unit 42 is attached to the holder support bracket 34. The advance / retract drive unit 42 is configured, for example, by an air cylinder and has an advance / retract shaft 44 that can advance / retract in an advance / retract direction (left / right direction in FIG. 2). A connecting plate 46 is attached to the tip of the advance / retract shaft 44, i.e., the end opposite the main body of the advance / retract drive unit 42. The connecting plate 46 is intended to connect the advance / retract shaft 44 and the clamping members 50. The first clamping member 50a is fixedly attached to the connecting plate 46 on the side opposite the advance / retract drive unit 42. Furthermore, a clamping member support bracket 48 is fixedly attached to the connecting plate 46 on the side opposite the advance / retract drive unit 42. As shown in FIG. 3, two clamping member support brackets 48 are provided on the connecting plate 46, sandwiching the pair of clamping members 50 therebetween.

[0024] A second clamping member 50b is attached to the clamping member support bracket 48 via a support shaft 52. The second clamping member 50b is disposed rotatably about the support shaft 52 relative to the clamping member support bracket 48. The second clamping member 50b includes an attachment portion 50b2 extending downward from a base end portion of the main body portion 50b1, and a lever portion 50b3 extending upward from the base end portion of the main body portion 50b1. The support shaft 52 is located at the attachment portion 50b2. Therefore, the support shaft 52 is positioned downwardly offset from the main body portion 50b1.

[0025] The opening / closing drive unit 56 is formed, for example, by an air cylinder and has a drive shaft 57 that can move forward and backward relative to the main body of the opening / closing drive unit 56. A lever portion 50b3 of the second clamping member 50b is attached via a driven shaft 54 ​​to the tip of the drive shaft 57, i.e., the end opposite the main body of the opening / closing drive unit 56. The driven shaft 54 ​​is positioned above the main body portion 50b1 of the second clamping member 50b. The second clamping member 50b is rotatable around the driven shaft 54 ​​relative to the drive shaft 57. The opening / closing drive unit 56 is attached to the clamping member support bracket 48 via a support shaft 58.

[0026] In this embodiment, the advancing / retracting shaft 44 of the advancing / retracting drive unit 42 moves forward and backward, causing the pair of clamping members 50 to move forward and backward relative to the gap forming unit 60. Specifically, the advancing / retracting shaft 44 of the advancing / retracting drive unit 42 moves so as to protrude from the main body of the advancing / retracting drive unit 42, causing the pair of clamping members 50 to advance relative to the gap forming unit 60 (moving to the left in FIG. 2). Furthermore, the advancing / retracting shaft 44 of the advancing / retracting drive unit 42 moves so as to retract into the main body of the advancing / retracting drive unit 42, causing the pair of clamping members 50 to retreat relative to the gap forming unit 60 (moving to the right in FIG. 2).

[0027] In this embodiment, the pair of clamping members 50 is opened and closed by the advance and retreat of the drive shaft 57 of the opening and closing drive unit 56. Specifically, when the drive shaft 57 of the opening and closing drive unit 56 moves so as to protrude from the main body of the opening and closing drive unit 56, the tip of the second clamping member 50b moves away from the tip of the first clamping member 50a, and the pair of clamping members 50 enters an open state. When the drive shaft 57 of the opening and closing drive unit 56 moves so as to retract into the main body of the opening and closing drive unit 56, the tip of the second clamping member 50b moves closer to the tip of the first clamping member 50a, and the pair of clamping members 50 enters a closed state.

[0028] The gap forming portion 60 has the function of contacting the bag stack 100 and forming a gap 115 between two bags 110 adjacent to each other in the vertical direction dv in the bag stack 100. In particular, in the example shown, the tip portion 62 of the gap forming portion 60 contacts the bag stack 100 and forms a gap 115 between two adjacent bags 110. An intermediate portion of the gap forming portion 60 is attached to the gap forming portion support bracket 36 via a support shaft 64. The gap forming portion 60 is attached to the gap forming portion support bracket 36 so as to be rotatable about the support shaft 64.

[0029] A first spring locking portion 66 is provided at the rear end of the gap forming portion 60, i.e., the end opposite the tip end 62 with respect to the support shaft 64. The bag takeout device 30 has a second spring locking portion 68, and a spring (not shown) is hung between the first spring locking portion 66 and the second spring locking portion 68. In this embodiment, the spring is hung between the first spring locking portion 66 and the second spring locking portion 68 in a lightly stretched state. Therefore, the spring biases the first spring locking portion 66 in a direction approaching the second spring locking portion 68. The bag takeout device 30 has an abutting portion (not shown) against which the rear end of the gap forming portion 60 can abut. When the gap forming portion 60 rotates around the support shaft 64 (clockwise in FIG. 2 ) so that the first spring locking portion 66 approaches the second spring locking portion 68, the rear end of the gap forming portion 60 abuts against the abutment portion, thereby preventing further rotation of the gap forming portion 60. When no external force is acting on the gap forming portion 60, the rear end of the gap forming portion 60 abuts against the abutment portion. When an external force is acting on the gap forming portion 60, particularly when an external force that presses the tip end portion 62 downward acts on the gap forming portion 60, the gap forming portion 60 may rotate around the support shaft 64 (counterclockwise in FIG. 2 ) against the biasing force of the spring. When the action of such an external force is released, the biasing force of the spring causes the gap forming portion 60 to rotate clockwise in FIG. 2 , and the rear end of the gap forming portion 60 abuts against the abutment portion. This makes it possible to alleviate the pressing force acting on the bag stack 100 (bags 110) from the tip 62 when the tip 62 of the gap forming portion 60 comes into contact with the bag stack 100 (bags 110). Therefore, it is possible to effectively prevent damage to the bags 110 caused by contact of the gap forming portion 60.

[0030] In the example shown in FIGS. 2 and 3, the main body portion 50a1 of the first clamping member 50a and the main body portion 50b1 of the second clamping member 50b of the holding unit 40 are formed with through-holes 51a and 51b penetrating the main body portions 50a1 and 50b1 in the up-down direction (thickness direction). In the example shown, the through-holes 51a and 51b are provided in the central portions of the main body portions 50a1 and 50b1 in the width direction, from the middle portion to the base end portion of the main body portions 50a1 and 50b1. The dimensions (length and width) of the through-holes 51a and 51b are set so that the gap forming portion 60 can pass through the through-holes 51a and 51b. When the pair of clamping members 50 is in the open state, as shown in FIGS. 2 and 3, the gap forming portion 60 passes through the through-hole 51a of the first clamping member 50a but does not pass through the through-hole 51b of the second clamping member 50b. In contrast, when the pair of clamping members 50 advances in accordance with the operation of the forward / backward driving unit 42 and the pair of clamping members 50 enters a closed state, the gap forming unit 60 penetrates both the through hole 51a of the first clamping member 50a and the through hole 51b of the second clamping member 50b (see Figure 9).

[0031] In the example shown in FIG. 2, the tip 62 of the gap forming part 60 extends in a direction bent relative to the extension direction of the main body of the gap forming part 60. Furthermore, the tip 62 of the gap forming part 60 extends in a direction approximately parallel to the pair of clamping members 50. When the pair of clamping members 50 are in an open state as shown in FIG. 2, the tip 62 of the gap forming part 60 is positioned between the pair of clamping members 50 in the up-down direction. Furthermore, the most distal end of the tip 62 protrudes further forward than the tips of the pair of clamping members 50. Note that "forward" refers to the direction from the base end of the clamping member 50 to the tip.

[0032] In this embodiment, the tip 62 of the gap forming portion 60 has a tapered shape that becomes thinner toward the tip. In particular, in the example shown in Fig. 2, the lower surface of the tip 62 of the gap forming portion 60 extends horizontally, and the upper surface of the tip 62 extends in a direction inclined with respect to both the horizontal direction and the vertical direction dv. With a gap forming portion 60 having such a tip 62, when the tip 62 comes into contact with the bag stack 100, the tip 62 is properly inserted between two bags 110 adjacent in the vertical direction dv.

[0033] In this embodiment, the gap forming portion 60 is formed separately from the holding portion 40. The gap forming portion 60 being separate from the holding portion 40 means that the gap forming portion 60 and the holding portion 40 are not integrated. In other words, the gap forming portion 60 being separate from the holding portion 40 means that the holding portion 40 does not also serve as the gap forming portion 60. However, as long as the gap forming portion 60 and the holding portion 40 are formed separately, the gap forming portion 60 and the holding portion 40 may be attached to the same member and be movable integrally. In this embodiment, because the gap forming portion 60 is formed separately from the holding portion 40, the gap forming portion 60 and the holding portion 40 can perform different operations. For example, while one of the gap forming portion 60 and the holding portion 40 is stopped, the other can be operated. 8 and 9, in the present embodiment, while the gap forming unit 60 is stopped, the holding unit 40 can be moved toward the bag stack 100, or the pair of clamping members 50 of the holding unit 40 can be closed to clamp a predetermined number of bags 110 with the pair of clamping members 50. Because the gap forming unit 60 is formed separately from the holding unit 40, in the present embodiment, the formation of gaps 115 in the bag stack 100 by the gap forming unit 60 and the insertion of the holding unit 40 (second clamping member 50b) into the gaps 115 can be performed in separate steps, i.e., at different times.

[0034] When the gap forming portion and the retaining portion are integrally formed, i.e., when the retaining portion also functions as the gap forming portion, the formation of a gap in the bag stack and the insertion of the retaining portion into the gap are performed simultaneously. In other words, the retaining portion is inserted into a portion of the bag stack where no gap is formed between two adjacent bags. In this case, the bag and the retaining portion may rub against each other, potentially damaging the bag. In particular, when the bags included in the bag stack are stacked in the vertical direction dv, when the retaining portion is inserted between two adjacent bags, the bag located above the retaining portion is pressed against the retaining portion due to its own weight. This results in greater friction between the bag and the retaining portion. It is possible to reduce friction between the bag and the retaining portion by providing a roller or the like at the portion of the retaining portion that contacts the bag, but this would complicate the structure of the retaining portion and increase costs.

[0035] In contrast to this, in this embodiment, after forming a gap 115 between two adjacent bags 110 in the bag stack 100 using the gap forming unit 60, the holding unit 40 (second clamping member 50b) can be inserted into the gap 115, which effectively prevents the holding unit 40 and the bags 110 from rubbing against each other. This makes it possible to prevent scratches on the bags 110. This effect is particularly pronounced when the bags 110 included in the bag stack 100 are stacked in the vertical direction dv.

[0036] The detection unit 70 has a function of detecting the height of the upper surface 100a of the bag stack 100. In the example shown in FIG. 3, the detection unit 70 has a swing lever 72 and a detection sensor 76. The swing lever 72 is attached to the detection unit support bracket 38 via a support shaft 74. The swing lever 72 is disposed rotatably about the support shaft 74 with respect to the detection unit support bracket 38. The end of the swing lever 72 closest to the detection sensor 76 is referred to as a base end 72b, and the end opposite the base end 72b is referred to as a tip end 72a. The detection sensor 76 is fixedly attached to the detection unit support bracket 38. The detection unit 70 can detect that the swing lever 72 has come into contact with the upper surface 100a of the bag stack 100, for example, depending on the on / off state of the detection sensor 76.

[0037] The distance between the detection sensor 76 and the base end 72b of the swing lever 72 changes depending on the swing state of the swing lever 72. In this embodiment, the detection sensor 76 is switched on and off depending on the distance between the detection sensor 76 and the base end 72b. That is, the detection sensor 76 is turned on when the distance between the base end 72b and the detection sensor 76 is equal to or greater than a predetermined distance, and is turned off when the distance is smaller than the predetermined distance. Therefore, the swing state of the swing lever 72 can be detected from the on / off state of the detection sensor 76. When the detection sensor 76 is in the off state, it is determined that the swing lever 72 is not in contact with the upper surface 100a of the bag stack 100. When the detection sensor 76 is in the on state, it is determined that the swing lever 72 is in contact with the upper surface 100a of the bag stack 100. The height of the bag dispenser 30 at this time is set as the reference height corresponding to the height of the upper surface 100a of the bag stack 100. This allows the detection unit 70 to directly detect the height of the upper surface 100a of the bag stack 100. By having the detection unit 70 directly detect the height of the upper surface 100a of the bag stack 100, the height of the upper surface 100a of the bag stack 100 can be detected more accurately. Information regarding the on / off state of the detection sensor 76 is sent from the detection sensor 76 to the control unit 80.

[0038] Without being limited to this, the detection sensor 76 may measure the distance between the swing lever 72 (base end 72b) and the detection sensor 76, and calculate the relative height between the detection sensor 76 and the upper surface 100a of the bag stack 100 based on this distance. In this case, it becomes possible to detect the height of the upper surface 100a of the bag stack 100 more accurately.

[0039] In this embodiment, the detection unit 70 is attached to the mounting bracket 32 ​​and is configured to be movable integrally with the holding unit 40 and the gap forming unit 60. In this case, when the detection unit 70 detects the height of the upper surface 100a of the bag stack 100, that height is used as a reference height. In a subsequent process, the detection unit 70 can position the tip 62 of the gap forming unit 60 at a height that is a predetermined distance lower than the upper surface 100a. Therefore, the tip 62 can be positioned at a height that is a predetermined distance lower than the upper surface 100a with minimal movement. However, this is not limited to this, and the holding unit 40 and the gap forming unit 60 may move independently of the detection unit 70. For example, the detection unit 70 may include an imaging device such as a camera whose position is fixed. In this case, the height of the upper surface 100a of the bag stack 100 may be detected by processing an image captured by the imaging device.

[0040] The control unit 80 controls the operation of each part of the bag supplying device 10. In this embodiment, the control unit 80 controls the operation of each joint 24 and orientation adjustment mechanism 26 of the movement mechanism 20, and the operation of the advance / retract drive unit 42 and open / close drive unit 56 of the holder 40. In particular, the control unit 80 receives a signal related to the height of the upper surface 100a of the bag stack 10 from the detection unit 70 (detection sensor 76), and controls the operation of each part of the bag supplying device 10 based on this signal. The control unit 80 may also control the operation of other parts of the bag supplying device 10. The control unit 80 may also control devices other than the bag supplying device 10. Furthermore, the control unit 80 may receive signals from sensors or devices other than the detection sensor 76, and control the operation of each part of the bag supplying device 10 based on this signal. The control unit 80 may include a calculation unit such as a CPU and a storage unit such as a hard disk or SSD.

[0041] Next, a bag dispensing method using the bag dispensing device 30 of this embodiment will be described with reference to FIGS.

[0042] First, the bag stack 100 is placed on the stack holding part 120. Specifically, a plurality of bags 110 are stacked in the vertical direction dv and placed on the bottom 122 of the stack holding part 120. The plurality of bags 110 placed on the bottom 122 constitute the bag stack 100. In the illustrated example, one edge of the bag 110 included in the bag stack 100 is in contact with the wall part 124 of the stack holding part 120.

[0043] The height of the upper surface 100a of the bag stack 100 is detected (see FIG. 4). The control unit 80 controls the joints 24 and orientation adjustment mechanism 26 of the movement mechanism 20 to position the tip 72a of the swing lever 72 of the detection unit 70 above the bag stack 100. At this time, the base end 72b of the swing lever 72 is close to the detection sensor 76, which is in an OFF state. With the tip 72a positioned above the bag stack 100, the control unit 80 controls the joints 24 of the movement mechanism 20, etc., to move the bag removal device 30 downward. When the tip 72a of the swing lever 72 abuts against the upper surface 100a of the bag stack 100, the swing lever 72 rotates around the support shaft 74 (clockwise in FIG. 4), and the tip 72a is lifted. Accordingly, the base end 72b moves away from the detection sensor 76. When the distance between the base end 72b and the detection sensor 76 reaches a predetermined distance or greater, the detection sensor 76 turns on. This allows the detection unit 70 to directly detect the height of the upper surface 100a of the bag stack 100. The detection sensor 76 sends a signal indicating that it has turned on to the control unit 80. When the control unit 80 receives the signal indicating that the detection sensor 76 has turned on, it stores the height of the bag removal device 30 at that time as a reference height and stops the downward movement of the bag removal device 30.

[0044] The gap forming unit 60 is moved to position the tip 62 of the gap forming unit 60 at a height that is a predetermined distance lower than the upper surface 100a of the bag stack 100 (see FIG. 5). The control unit 80 controls the joints 24 and the direction adjustment mechanism 26 of the movement mechanism 20 to point the tip 62 of the gap forming unit 60 toward the bag stack 100. At this time, the control unit 80 controls the joints 24 and the direction adjustment mechanism 26 so that the tip 62 and the main bodies 50a1, 50b1 of the clamping members 50a, 50b extend in a substantially horizontal direction. Furthermore, based on the detection result of the detection unit 70, the control unit 80 positions the tip 62 at a height that is a predetermined distance lower than the upper surface 100a of the bag stack 100. Specifically, the height of the upper surface 100a is set as a reference height, and the tip 62 is positioned at a height that is a predetermined distance lower than the reference height. This predetermined distance corresponds to the number of bags 110 to be held by the holding unit 40 in the process described below. Specifically, the predetermined distance is a distance calculated based on the total thickness of the predetermined number of bags 110 to be held by the holding unit 40. By positioning the tip 62 of the gap forming unit 60 at a height that is a predetermined distance lower than the upper surface 100a based on the detection result of the detection unit 70, it is possible to appropriately position the tip 62 of the gap forming unit 60 below the predetermined number of bags 110 that are positioned below the upper surface 100a of the bag stack 100 based on the height of the upper surface 100a of the bag stack 100 detected by the detection unit 70. This enables the holding unit 40 to stably hold the predetermined number of bags 110. Note that this predetermined distance may be stored in advance in the memory unit of the control unit 80, or may be input by an operator via an input unit (not shown) when starting to remove bags 110 from the bag stack 100.

[0045] The gap forming unit 60 is moved so that it comes into contact with the bag stack 100 (see FIG. 6 ). In this embodiment, the control unit 80 controls each joint 24 of the movement mechanism 20 to move the gap forming unit 60 horizontally and bring the tip end 62 into contact with the bag stack 100. In the illustrated example, at least a portion of the tip end 62 is inserted between two bags 110 adjacent to each other in the vertical direction dv in the bag stack 100. This positions a predetermined number of bags 110 above the tip end 62 to be held by the holding unit 40 in a process described below. Note that if the number of bags 110 taken out in one bag 110 takeout operation does not need to be strictly controlled, the number of bags 110 positioned above the tip end 62 may vary slightly. For example, if it is intended that 30 bags 110 be removed in one operation, when the leading end 62 is inserted into the bag stack 100, 30 bags 110, 28 bags 110, or 31 bags 110 may be located above the leading end 62. Note that if the bag stack 100 is configured by stacking bag bundles in which a predetermined number of bags 110 are bundled together, the leading end 62 is inserted between two bag bundles adjacent to each other in the vertical direction dv. At this time, one bag bundle or multiple bag bundles may be located above the leading end 62.

[0046] The gap forming unit 60 is moved to form a gap 115 between two adjacent bags 110 in the bag stack 100 (see FIG. 7). In this embodiment, the control unit 80 controls each joint 24 of the movement mechanism 20 to move the gap forming unit 60 so that the tip end 62 of the gap forming unit 60 enters the bag stack 100 and moves upward, thereby forming a gap 115 between two bags 110 that are adjacent in the vertical direction dv with the tip end 62 sandwiched between them. This makes it possible to prevent bags 110 located above the tip end 62 from bending and sliding down from the tip end 62.

[0047] Next, a portion of the holding unit 40 is inserted into the gap 115 (see FIG. 8 ). In particular, with the gap forming unit 60 forming the gap 115 and stopped, the control unit 80 controls the advancing / retracting drive unit 42 to insert the tip of the main body 50b1 of the second clamping member 50b into the gap 115. In the illustrated example, under the control of the control unit 80, the advancing / retracting shaft 44 of the advancing / retracting drive unit 42 is moved so as to protrude from the main body of the advancing / retracting drive unit 42. As a result, the first clamping member 50a and the second clamping member 50b attached to the tip of the advancing / retracting shaft 44 via the connecting plate 46 move toward the bag stack 100. As the first clamping member 50a and the second clamping member 50b move, the tip of the main body 50a1 of the first clamping member 50a is positioned above the uppermost bag 110 in the bag stack 100 (the bag 110 forming the upper surface 100a). In this embodiment, after forming a gap 115 between two adjacent bags 110 in the bag stack 100 using the gap forming unit 60, the holding unit 40 (second clamping member 50b) can be inserted into the gap 115, which effectively prevents the holding unit 40 and the bags 110 from rubbing against each other. This makes it possible to prevent scratches on the bags 110.

[0048] Thereafter, the holding unit 40 holds the bag 110 located above the gap 115 (see FIG. 9). The control unit 80 controls the open / close drive unit 56 to close the pair of clamping members 50. In the illustrated example, under the control of the control unit 80, the drive shaft 57 of the open / close drive unit 56 is moved so as to retract into the main body of the open / close drive unit 56. As a result, the tip of the second clamping member 50b approaches the tip of the first clamping member 50a, and the pair of clamping members 50 enters the closed state. As the pair of clamping members 50 enters the closed state, the bag 110 located above the gap 115 is clamped between the pair of clamping members 50.

[0049] The holding unit 40 is moved to move the bags 110 held by the holding unit 40 from the bag stack 100 (see FIG. 10 ). The control unit 80 controls each joint 24 and orientation adjustment mechanism 26 of the movement mechanism 20 to move the bags 110 held by the holding unit 40. The bags 110 held by the holding unit 40 are moved, for example, to a bag supply unit of a bag processing machine. However, this is not limiting, and the bags 110 held by the holding unit 40 may also be moved to another location.

[0050] When repeatedly moving bags 110 from the bag stack 100, after the bags 110 held by the holding unit 40 have been moved, the control unit 80 controls each joint 24 and orientation adjustment mechanism 26 of the movement mechanism 20 to move the bag removal device 30, and the process returns to the step of detecting the height of the upper surface 100a of the bag stack 100 described with reference to Figure 4. If the step of detecting the height of the upper surface 100a of the bag stack 100 is performed each time the bags 110 are moved, even if the height of the bag stack 100 changes due to, for example, a portion of the bag stack 100 collapsing during the previous movement of the bags 110, the height of the upper surface 100a can be detected again, allowing the bags 110 to be moved more appropriately from the bag stack 100. However, without being limited to this, the height of the upper surface 100a may be detected only when the bag 110 is moved for the first time, and the height at which the tip 62 of the gap forming portion 60 is positioned may be determined using the height of the upper surface 100a detected at this time as a reference when the bag 110 is moved for the second or subsequent times.

[0051] The bag removal device 30 of this embodiment is a bag removal device 30 that removes a predetermined number of bags 110 from a bag stack 100 that includes a plurality of bags 110 stacked in the vertical direction dv, and is equipped with a holding section 40 that holds the predetermined number of bags 110, and a gap forming section 60 that is configured separately from the holding section 40 and contacts the bag stack 100 to form a gap 115 between two bags 110 adjacent to each other in the vertical direction dv in the bag stack 100.

[0052] The bag removal device 30 of this embodiment further includes a control unit 80, which controls the following: moving the gap forming unit 60 to position the tip 62 of the gap forming unit 60 at a height a predetermined distance lower than the upper surface 100a of the bag stack 100; moving the gap forming unit 60 to bring the gap forming unit 60 into contact with the bag stack 100; moving the gap forming unit 60 to form a gap 115 between two bags 110 adjacent in the vertical direction dv in the bag stack 100; inserting a portion of the holding unit 40 into the gap 115; using the holding unit 40 to hold the bag 110 located above the gap 115; and moving the holding unit 40 to move the bag 110 held by the holding unit 40 from the bag stack 100.

[0053] The bag removal method of this embodiment is a bag removal method for removing a predetermined number of bags 110 from a bag stack 100 including a plurality of bags 110 stacked in a vertical direction dv, using a bag removal device 30 equipped with a holding unit 40 that holds a predetermined number of bags 110 and a gap forming unit 60 configured separately from the holding unit 40, and includes the steps of: moving the gap forming unit 60 to position a tip end 62 of the gap forming unit 60 at a height that is a predetermined distance lower than an upper surface 100a of the bag stack 100; The process includes the steps of: moving the gap forming portion 60 to bring the gap forming portion 60 into contact with the bag stack 100; moving the gap forming portion 60 to form a gap 115 between two bags 110 adjacent in the vertical direction dv in the bag stack 100; inserting a portion of the holding portion 40 into the gap 115; holding the bag 110 located above the gap 115 with the holding portion 40; and moving the bag 110 held by the holding portion 40 from the bag stack 100.

[0054] According to this bag removal device 30 and bag removal method, after forming a gap 115 between two adjacent bags 110 in the bag stack 100 using the gap forming unit 60, the holding unit 40 (second clamping member 50b) is inserted into the gap 115, thereby effectively preventing the holding unit 40 and the bags 110 from rubbing against each other. This makes it possible to prevent scratches on the bags 110. This effect is particularly pronounced when the bags 110 included in the bag stack 100 are stacked in the vertical direction dv.

[0055] In the bag removal device 30 of this embodiment, the holding section 40 has a pair of clamping members 50 that clamp a predetermined number of bags 110, and the control section 80 causes one of the pair of clamping members 50 to enter the gap 115 when the gap forming section 60 has formed the gap 115 and is stopped.

[0056] According to this bag removal device 30, the gap forming part 60 is stopped when one of the pair of clamping members 50 is inserted into the gap 115, so that the gap forming part 60 and the bag 110 are prevented from rubbing against each other. This further prevents the bag 110 from being damaged.

[0057] In the bag take-out device 30 of this embodiment, the control unit 80 moves the gap forming unit 60 so that the tip end 62 enters the bag stack 100 and moves upward, thereby forming the gap 115.

[0058] According to this bag take-out device 30, it is possible to prevent bags 110 located above the tip end 62 of the gap forming portion 60 from bending and sliding off the tip end 62.

[0059] It should be noted that various modifications can be made to the above-described embodiment. Modifications of the above-described embodiment will be described below with reference to the drawings as appropriate. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-described embodiment will be designated by the same reference numerals as those used for the corresponding parts in the above-described embodiment, and duplicated descriptions will be omitted.

[0060] FIG. 11 is a side view showing a modified bag takeout device 30, and FIGS. 12 and 13 are diagrams illustrating a bag takeout method using the modified bag takeout device 30.

[0061] The tip of the gap forming section 60 in this modified example (the edge of the tip portion 62) has a tip surface 62a that faces the side surface of the bag stack 100 (the edge of the bags 110). The tip surface 62a may include a flat surface. In the example shown in FIGS. 11 to 13, the tip surface 62a includes a flat surface extending in the vertical direction dv. In the example shown, the tip portion 62 has a substantially constant thickness toward its edge. A friction member 63 is attached to the tip surface 62a. The friction member 63 is made of a material such as an elastomer, for example, rubber. The other parts of the bag dispensing device 30 in this modified example are configured in the same way as the bag dispensing device 30 in the above-described embodiment, and therefore detailed description thereof will be omitted.

[0062] A bag removal method using bag removal device 30 of this modified example will be described with reference to FIGS.

[0063] Figure 11 is a view corresponding to Figure 5 of the embodiment described above. As shown in the figure, a step is performed in which the gap forming section 60 is moved to position the tip end 62 of the gap forming section 60 at a height that is a predetermined distance lower than the upper surface 100a of the bag stack 100. At this time, the friction member 63 provided at the tip end of the gap forming section 60 faces the side surface of the bag stack 100 (the edge of the bags 110).

[0064] Next, the gap forming portion 60 is moved to contact the bag stack 100 (see FIG. 12). In this embodiment, the tip of the gap forming portion 60 has a tip surface 62a, and therefore, unlike the above-described embodiment, the tip portion 62 abuts against the side of the bag stack 100 (the edge of the bags 110), but is not inserted between two adjacent bags 110 in the bag stack 100.

[0065] Next, the gap forming unit 60 is moved to form a gap 115 between two adjacent bags 110 in the bag stack 100 (see FIG. 13 ). In this modification, the control unit 80 controls each joint 24 of the movement mechanism 20 to move the gap forming unit 60 so that the tip 62 of the gap forming unit 60 moves toward the bag stack 100 and also moves upward. At this time, the edge of the bag 110 in contact with the friction member 63 moves upward together with the gap forming unit 60 due to the friction force acting between the friction member 63 and the edge of the bag 110. As a result, a gap 115 is formed between the bag 110 whose edge has moved upward together with the gap forming unit 60 and the bag 110 located below it. Thereafter, a portion of the holding unit 40 is inserted into this gap 115. The other steps are the same as those of the bag removal method of the above-described embodiment, and therefore detailed description thereof will be omitted.

[0066] In this modification, after forming a gap 115 between two adjacent bags 110 in the bag stack 100 using the gap forming portion 60 having the tip surface 62a (friction member 63), the holding portion 40 (second clamping member 50b) is inserted into the gap 115, so that it is possible to effectively prevent the holding portion 40 and the bags 110 from rubbing against each other. This makes it possible to prevent scratches on the bags 110.

[0067] 11 to 13, the friction member 63 is attached to the tip surface 62a of the gap forming portion 60, but the present invention is not limited to this, and the friction member 63 may be omitted and the tip surface 62a of the gap forming portion 60 may be roughened to increase the friction force acting between the tip surface 62a and the edge of the bag 110. Furthermore, the tip surface 62a may be provided with irregularities so that the edge of the bag 110 is caught on the irregularities and lifted up.

[0068] Another modified example of the bag removal device will be described with reference to Figures 14 to 22. Figure 14 is a side view showing another modified example of the bag removal device 30, Figures 15 and 16 are enlarged views of the gap forming section 60 of the bag removal device 30, and Figures 17 to 22 are diagrams explaining a bag removal method using the bag removal device 30.

[0069] In the example shown in FIG. 14 , the bag takeout device 30 includes a mounting bracket 32 ​​for mounting the bag takeout device 30 to the movement mechanism 20, a holder support bracket 34 for supporting the holder 40, and a gap forming unit support arm 37 for supporting the gap forming unit 60. The bag takeout device 30 of this modified example further includes a detection unit 70. The detection unit 70 of this modified example may be configured similarly to the detection unit 70 described with reference to FIG. 3 , and therefore a detailed description thereof will be omitted. The mounting bracket 32 ​​is fixedly attached to the tip of the movement mechanism 20, particularly to the orientation adjustment mechanism 26. In other words, when the rotating body of the orientation adjustment mechanism 26 rotates, the mounting bracket 32 ​​also rotates together with the rotating body. A holder support bracket 34 is attached to the mounting bracket 32 ​​on the side opposite the movement mechanism 20. A gap forming unit support arm 37 is attached to the holder support bracket 34.

[0070] The holding unit 40 includes a pair of clamping members 50, an opening / closing drive unit 56 that drives the pair of clamping members 50 to open and close, and an advancing / retreating drive unit 42 that drives the clamping members 50 to move forward and backward. The holding unit 40 holds a predetermined number of bags 110 included in the bag stack 100 using the pair of clamping members 50. Specifically, the predetermined number of bags 110 are sandwiched between the pair of clamping members 50, and the tips of the pair of clamping members 50 are brought close to each other to close the pair of clamping members 50, thereby holding the predetermined number of bags 110.

[0071] The pair of clamping members 50 includes a first clamping member 50a located relatively above and a second clamping member 50b located relatively below. The advance / retract drive unit 42 is attached to the holder support bracket 34. The advance / retract drive unit 42 is configured, for example, by an air cylinder and has an advance / retract shaft 44 that can advance / retract in an advance / retract direction (left / right direction in FIG. 14 ). A connecting plate 46 is attached to the tip of the advance / retract shaft 44, i.e., the end opposite the main body of the advance / retract drive unit 42. The connecting plate 46 is intended to connect the advance / retract shaft 44 and the clamping member 50. A clamping member support bracket 48 is fixedly attached to the connecting plate 46 on the side opposite the advance / retract drive unit 42. A second clamping member 50b is fixedly attached to the clamping member support bracket 48 on the side opposite the connecting plate 46. An opening / closing drive unit support bracket 49 is fixedly attached to the clamping member support bracket 48.

[0072] A first clamping member 50a is attached to the clamping member support bracket 48 via a support shaft 52. The first clamping member 50a is disposed rotatably about the support shaft 52 relative to the clamping member support bracket 48. The first clamping member 50a includes an attachment portion 50a2 extending downward from a base end portion of the main body portion 50a1, and a lever portion 50a3 extending downward from the base end portion of the main body portion 50a1. The support shaft 52 is located at the attachment portion 50a2. Therefore, the support shaft 52 is positioned downwardly offset from the main body portion 50a1.

[0073] The opening / closing drive unit 56 is formed, for example, by an air cylinder and has a drive shaft 57 that can move forward and backward relative to the main body of the opening / closing drive unit 56. A lever portion 50a3 of the first clamping member 50a is attached via a driven shaft 54 ​​to the tip of the drive shaft 57, i.e., the end opposite the main body of the opening / closing drive unit 56. The driven shaft 54 ​​is positioned downwardly from the main body portion 50a1 of the first clamping member 50a. The first clamping member 50a is rotatable around the driven shaft 54 ​​relative to the drive shaft 57. The opening / closing drive unit 56 is attached to the opening / closing drive unit support bracket 49 via a support shaft 58.

[0074] In this embodiment, the advancing / retracting shaft 44 of the advancing / retracting drive unit 42 moves forward and backward, causing the pair of clamping members 50 to move forward and backward relative to the gap forming unit 60. Specifically, the advancing / retracting shaft 44 of the advancing / retracting drive unit 42 moves so as to protrude from the main body of the advancing / retracting drive unit 42, causing the pair of clamping members 50 to advance relative to the gap forming unit 60 (moving to the left in FIG. 14). Furthermore, the advancing / retracting shaft 44 of the advancing / retracting drive unit 42 moves so as to retract into the main body of the advancing / retracting drive unit 42, causing the pair of clamping members 50 to retreat relative to the gap forming unit 60 (moving to the right in FIG. 14).

[0075] In this embodiment, the pair of clamping members 50 are opened and closed by the advance and retreat of the drive shaft 57 of the opening and closing drive unit 56. Specifically, when the drive shaft 57 of the opening and closing drive unit 56 moves so as to protrude from the main body of the opening and closing drive unit 56, the tip of the first clamping member 50a moves away from the tip of the second clamping member 50b, and the pair of clamping members 50 enters an open state. When the drive shaft 57 of the opening and closing drive unit 56 moves so as to retract into the main body of the opening and closing drive unit 56, the tip of the first clamping member 50a moves closer to the tip of the second clamping member 50b, and the pair of clamping members 50 enters a closed state.

[0076] The gap forming portion 60 of this modified example will be described with reference to Figures 15 and 16. A housing recess 37a that houses at least a part of the gap forming portion 60 is formed at the tip of the gap forming portion support arm 37. In this modified example, the gap forming portion 60 includes a contact member 65 and a biasing member 67. The contact member 65 is a member configured to be able to contact the bag stack 100. The contact member 65 has a main body portion 65a and a friction member 63. The friction member 63 is attached to the front end of the main body portion 65a. Here, the ends of the contact member 65 and the main body portion 65a that are close to the bag stack 100 are referred to as the front ends, and the ends that are away from the bag stack 100 are referred to as the rear ends. The main body portion 65a can be made of a metal material, a resin material, or the like. The friction member 63 is a member intended to come into contact with the bag stack 100 (bags 110) when forming a gap 115 between two bags 110 adjacent in the vertical direction dv in the bag stack 100. The friction member 63 is made of a member such as an elastomer, for example, rubber.

[0077] In this modified example, a support member 69 that supports the contact member 65 is disposed within the accommodating recess 37a. The support member 69 is disposed between the accommodating recess 37a and the contact member 65 and is fixed to the accommodating recess 37a. The support member 69 supports a main body portion 65a of the contact member 65. The contact member 65 is supported by the support member 69 so as to be movable along its axial direction. In this modified example, a flange portion 65b is provided at the rear end of the main body portion 65a of the contact member 65. The flange portion 65b has a large dimension (width) in a direction perpendicular to the axis of the main body portion 65a. In other words, the width of the flange portion 65b is larger than the width of the rest of the main body portion 65a. The flange portion 65b has a shape and dimensions that prevent it from slipping out of the support member 69. This prevents the contact member 65 from slipping out of the accommodating recess 37a.

[0078] The biasing member 67 is a member for biasing the contact member 65 toward the bag stack 100. The biasing member 67 is disposed between the rear end of the contact member 65 (main body portion 65a) and the accommodating recess 37a. The biasing member 67 may be, for example, an elastic member such as a coil spring. When no pressing force is applied to the contact member 65, the contact member 65 protrudes relatively far from the accommodating recess 37a, as shown in FIG. 15. When the contact member 65 comes into contact with the bag stack 100 and presses against the bag stack 100, the contact member 65 receives a pressing force (reaction force) from the bag stack 100. As a result, as shown in FIG. 16, the contact member 65 moves toward the accommodating recess 37a against the biasing force of the biasing member 67, and the amount of protrusion of the contact member 65 from the accommodating recess 37a decreases. At this time, the biasing member 67 is compressed between the rear end of the contact member 65 (main body portion 65a) and the accommodating recess 37a. As a result, the compressed biasing member 67 applies a biasing force to the rear end of the contact member 65 (main body portion 65a). When the contact member 65 moves away from the bag stack 100 and the pressing force acting on the contact member 65 is released, the biasing force of the biasing member 67 causes the contact member 65 to move so as to protrude from the accommodating recess 37a and return to the state shown in FIG. 15. In this modified example, when the contact member 65 comes into contact with the bag stack 100, the biasing member 67 is configured to bias the contact member 65 in the horizontal direction.

[0079] Next, a bag removal method using bag removal device 30 of this modified example will be described with reference to FIGS.

[0080] First, the bag stack 100 is placed on the stack holding unit 120. Next, the height of the upper surface 100a of the bag stack 100 is detected. The detection of the height of the upper surface 100a can be performed in the same manner as in the example described with reference to Fig. 4, and therefore a detailed description thereof will be omitted.

[0081] 17, a step is performed in which the gap forming unit 60 is moved to position the tip of the contact member 65 of the gap forming unit 60 at a height that is a predetermined distance lower than the upper surface 100a of the bag stack 100. At this time, the friction member 63 provided at the tip of the contact member 65 faces the side surface of the bag stack 100 (the edge of the bags 110). This step can be performed in the same way as the example described with reference to FIG. 5, so a detailed description will be omitted.

[0082] The gap forming unit 60 is moved to bring the tip of the contact member 65 (friction member 63) into contact with the side of the bag stack 100 (the edge of the bag 110) (see FIG. 18). In this modification, the control unit 80 controls each joint 24 of the movement mechanism 20 to move the gap forming unit 60 so that the tip of the contact member 65 moves toward the bag stack 100.

[0083] The gap forming unit 60 is moved to form a gap 115 between two adjacent bags 110 in the bag stack 100 (see FIG. 19 ). In this modification, the control unit 80 controls each joint 24 of the movement mechanism 20 to move the gap forming unit 60 so that the tip 62 of the gap forming unit 60 moves toward the bag stack 100 and also moves upward. At this time, the edge of the bag 110 in contact with the friction member 63 moves upward together with the gap forming unit 60 due to the friction force acting between the friction member 63 and the edge of the bag 110. As a result, a gap 115 is formed between the bag 110 whose edge has moved upward together with the gap forming unit 60 and the bag 110 located below it.

[0084] At this time, if the contact member 65 is pressed strongly against the bag stack 100, the bags 110 included in the bag stack 100 may bend significantly, causing the bags 110 to become misaligned or to collapse from the bag stack 100. Furthermore, if the contact member 65 is pressed strongly against the bag stack 100, the portion of the bag 110 that comes into contact with the contact member 65 may be deformed or damaged. In this modified example, the contact member 65 is configured to be able to advance and retreat relative to the gap forming unit support arm 37 (accommodation recess 37a). Furthermore, the gap forming unit 60 of this modified example has a biasing member 67 that biases the contact member 65 toward the bag stack 100. Therefore, when the contact member 65 is pressed strongly against the bag stack 100, the biasing force of the biasing member 67 can ensure an appropriate pressing force while moving the contact member 65 in a direction away from the bag stack 100, thereby reducing the pressing force of the contact member 65 against the bag stack 100. This makes it possible to prevent the bags 110 from being displaced or collapsing from the bag stack 100 due to a large bending of the bags 110. It is also possible to prevent the portions of the bags 110 that come into contact with the contact members 65 from being deformed or scratched due to the contact members 65 being pressed strongly against the bag stack 100.

[0085] Furthermore, in this modification, the biasing member 67 is configured to bias the contact member 65 in the horizontal direction when the contact member 65 contacts the bag stack 100. This makes it possible to more effectively prevent the bags 110 from shifting position or collapsing from the bag stack 100.

[0086] Next, a part of the holding unit 40 is inserted into the gap 115 (see FIG. 20). In particular, with the gap forming unit 60 forming the gap 115 and stopped, the control unit 80 controls the advance / retreat drive unit 42 to insert the tip of the main body 50b1 of the second clamping member 50b into the gap 115. This step can be performed in the same manner as in the example described with reference to FIG. 8, and therefore a detailed description thereof will be omitted.

[0087] Next, the gap forming unit 60 is moved in a direction away from the bag stack 100, and the contact member 65 is moved away from the bag stack 100 (see FIG. 21). This releases the pressing force acting on the bag stack 100 from the contact member 65, and the bags 110 positioned above the second clamping member 50b fall onto the second clamping member 50b.

[0088] Thereafter, the holding unit 40 holds the bag 110 located on the second clamping member 50b (see FIG. 22). The control unit 80 controls the open / close drive unit 56 to close the pair of clamping members 50. In the illustrated example, under the control of the control unit 80, the drive shaft 57 of the open / close drive unit 56 is moved so as to retract into the main body of the open / close drive unit 56. As a result, the tip of the first clamping member 50a approaches the tip of the second clamping member 50b, and the pair of clamping members 50 enters the closed state. As the pair of clamping members 50 enters the closed state, the bag 110 located on the second clamping member 50b is clamped between the pair of clamping members 50.

[0089] Here, if the bags 110 are clamped between the pair of clamping members 50 while the contact members 65 are in contact with the bag stack 100, the movement of the clamping members 50 may move the bags 110 to be clamped, causing the contact members 65 and the bag stack 100 to rub against each other. In this case, the portions of the bags 110 that come into contact with the contact members 65 may be deformed or damaged. In this modified example, the bags 110 are clamped after the contact members 65 are separated from the bag stack 100, so that deformation or damage to the bags 110 due to rubbing between the contact members 65 and the bag stack 100 can be suppressed.

[0090] Furthermore, if the second clamping member 50b is moved significantly while the contact member 65 is separated from the bag stack 100, the bags 110 located on the second clamping member 50b may become displaced or fall off the bag stack 100. In this modified example, by moving the first clamping member 50a located above the bag 110 to be clamped to clamp the bag 110, it is possible to prevent the bags 110 located on the second clamping member 50b from becoming displaced or falling off the bag stack 100.

[0091] The other steps are the same as those in the bag removal method of the above-described embodiment, and therefore detailed description thereof will be omitted.

[0092] In the bag removal device 30 of this modified example, the gap forming section 60 includes a contact member 65 that can come into contact with the bag stack 100 , and a biasing member 67 that biases the contact member 65 toward the bag stack 100 .

[0093] According to this bag takeout device 30, when the contact member 65 is pressed strongly against the bag stack 100, the biasing force of the biasing member 67 ensures an appropriate pressing force while moving the contact member 65 in a direction away from the bag stack 100, thereby reducing the pressing force of the contact member 65 against the bag stack 100. This makes it possible to prevent the bags 110 from shifting position or collapsing from the bag stack 100 due to the contact member 65 being pressed strongly against the bag stack 100 and causing the bags 110 to bend significantly. It is also possible to prevent the portions of the bags 110 that come into contact with the contact member 65 from being deformed or scratched due to the contact member 65 being pressed strongly against the bag stack 100.

[0094] In the bag dispensing device 30 of this modified example, the biasing member 67 biases the contact member 65 in the horizontal direction.

[0095] According to this bag removal device 30, the bags 110 can be more effectively prevented from shifting position or from collapsing from the bag stack 100. [Explanation of symbols]

[0096] 10 Bag feeding device 20 Moving mechanism 22 Arm 24 joints 26 Orientation adjustment mechanism 30 Bag removal device 40 Holding part 42 Advance / retreat drive unit 44 Advance / retreat axis 50 Clamping member 50a First clamping member 50b Second clamping member 52 Support shaft 54 Driven shaft 56 Opening and closing drive unit 57 Drive shaft 58 Support shaft 60 Gap forming part 62 Tip 62a Tip surface 63 Friction materials 64 Support shaft 65 Contact member 66 First spring locking part 67 biasing member 68 Second spring locking part 70 Detector 72 Swing lever 72a Tip 72b Proximal end 74 Support shaft 76 Detection sensor 80 Control Unit 100 bags laminate 100a top surface 110 bags 115 Gap 120 laminated body holding portion

Claims

1. A bag dispensing device that dispenses a predetermined number of bags from a bag stack including a plurality of bags stacked in a vertical direction, a holding section for holding the predetermined number of bags; a gap forming portion that is configured separately from the holding portion and contacts the bag stack to form a gap between two adjacent bags in the bag stack in the vertical direction, The gap forming portion includes a contact member that contacts the bag stack, and a biasing member that is formed separately from the contact member and biases the contact member toward the bag stack.

2. Further comprising a control unit, The control unit The gap forming portion is moved to position the tip of the contact member of the gap forming portion at a height that is lower by a predetermined distance than the upper surface of the bag stack, The gap forming portion is moved to bring the tip of the contact member of the gap forming portion into contact with the bag stack, The gap forming unit is moved to form the gap between two of the bags adjacent to each other in the vertical direction in the bag stack. A part of the holding portion is inserted into the gap, The holding portion holds the bag located above the gap, The bag dispensing device according to claim 1 , wherein the holding section is moved to control the movement of the bag held by the holding section from the stack of bags.

3. the holding section has a pair of clamping members that clamp the predetermined number of bags, The bag dispensing device according to claim 2 , wherein the control unit causes the pair of clamping members to clamp the predetermined number of bags after moving the contact member away from the stack of bags.

4. The bag removal device according to claim 3, wherein the control unit causes the pair of clamping members to clamp the predetermined number of bags by moving only one of the pair of clamping members that is positioned above the predetermined number of bags.

5. A bag removal device as described in any one of claims 1 to 4, wherein the contact member has a main body portion and a friction member, and the biasing member is an elastic member.

6. The bag dispensing device according to claim 5 , wherein the biasing member biases the contact member in a horizontal direction.

7. A bag removal method for removing a predetermined number of bags from a bag stack including a plurality of bags stacked in a vertical direction, using a bag removal device including a holding section that holds a predetermined number of bags and a gap forming section that is configured separately from the holding section, comprising: a step of moving the gap forming portion to position a tip end of the gap forming portion at a height that is lower by a predetermined distance than an upper surface of the bag stack; a step of moving the gap forming portion so that the gap forming portion comes into contact with the bag stack; a step of moving the gap forming unit to form a gap between two of the bags adjacent in the vertical direction in the bag stack; inserting a portion of the holding portion into the gap; a step of holding the bag located above the gap with the holding portion; and moving the bag held by the holding portion from the bag stack, The gap forming portion has a contact member that contacts the bag stack and a biasing member that is configured as a separate member from the contact member, The bag removal method, wherein in the step of bringing the gap forming portion into contact with the bag stack, the biasing member biases the contact member toward the bag stack.

Images