Gripping device and transport system

Abstract

To provide a gripping device and a conveying system capable of stably gripping even an object having flexibility.SOLUTION: A gripping device AA grips a flexible object C around which a binding wire B is wound. The gripping device AA has one or more gripping units 50A, 50B. The gripping unit 50A includes pressing members 51 that press and dent the surfaces of the object C, claw members 54 that are inserted between the surfaces of the object C pressed by the pressing members 51 and the binding wire B and engage with the binding wire B, and actuators 56 that insert and remove the claw members 54 between the surfaces of the object C and the binding wire B. Since the object C is gripped by locking the claw member 54 to the binding wire B, even the flexible object C can be stably gripped.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a gripping device and a transport system, and more particularly to a gripping device for gripping a flexible object and a transport system for transporting a flexible object. [Background technology]

[0002] Hotels, hospitals, and other facilities use a large amount of fabrics, such as towels and sheets. Used fabrics are washed in a laundry factory and reused in the hotel, hospital, or other facility. Laundries are equipped with linen facilities connected to multiple fabric processing devices. The linen facilities include, for example, a fabric spreading device, a roll ironer, and a fabric folding device. Washed fabrics are spread out in the fabric spreading device, ironed in the roll ironer, and folded in the fabric folding device.

[0003] The fabric folding device stacks a predetermined number of folded fabrics and then discharges them. The stack of fabrics is transported on a collecting conveyor and then bound by a binding machine. After binding, the bound stack of fabrics is collected by workers (see Patent Document 1). The workers then stack the collected stack of fabrics on a rack or the like. This work is hard work for workers, so automation by machinery is desirable. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-60794 Summary of the Invention [Problem to be solved by the invention]

[0005] It is difficult to mechanically grasp flexible objects such as fabric laminates. For example, even if a robotic hand grips the object from both sides, the object deforms and cannot be firmly grasped or lifted. Therefore, conveyors are commonly used to transport flexible objects. However, when stacking objects in a rack, interference between the conveyor and the rack frame makes it difficult to position the objects in the desired position within the rack. Furthermore, since the orientation of the objects cannot be controlled, it is difficult to arrange the objects tightly within the rack or to stack them stably.

[0006] In view of the above circumstances, the present invention aims to provide a gripping device that can stably grip even flexible objects, and a conveying system that can transport even flexible objects while stably gripping them. [Means for solving the problem]

[0007] The gripping device of the first embodiment is a gripping device that grips a flexible object wrapped with a binding wire, and is equipped with one or more gripping units, each of which has a pressing member that presses a portion of the surface of the object near the binding wire to indent the surface, a claw member that is inserted between the surface of the object held by the pressing member and the binding wire and engages with the binding wire, and an actuator that inserts and removes the claw member between the surface of the object and the binding wire. The gripping device of the second aspect is characterized in that, in the first aspect, the gripping unit has a pair of pressing members that press two points on the surface of the object, each of which sandwiches the binding wire. The gripping device of the third aspect is characterized in that, in the first or second aspect, it is provided with a distance sensor that measures the distance to the object or detects that the distance to the object has become suitable for inserting the claw member between the surface of the object and the binding wire. The gripping device of a fourth aspect is the gripping device of any one of the first to third aspects, further comprising an anti-vibration member that comes into contact with the object and suppresses the vibration of the object. A transfer system according to a fifth aspect is characterized by including the gripping device according to any one of the first to fourth aspects, and a transfer robot that moves the gripping device. [Effects of the Invention]

[0008] According to the first aspect, the claw members grip the object by locking onto the binding wire, so that even flexible objects can be stably gripped. According to the second aspect, two recesses are formed on the surface of the object at two locations on either side of the binding wire, so that a gap is easily generated between the surface of the object and the binding wire, making it easy to insert the claw members. According to the third aspect, the claw member can be disposed at an appropriate position relative to the binding wire, making it easy to insert the claw member between the surface of the object and the binding wire. According to the fourth aspect, the anti-sway member comes into contact with the object, thereby preventing the object from swinging around the claw member, and allowing the object to be stably gripped. According to the fifth aspect, the object can be transported to a target position by moving the gripping device gripping the object. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view of the linen facility according to the first embodiment. FIG. [Figure 2] Figure (A) is a perspective view of the fabric stack before bundling, and Figure (B) is a perspective view of the fabric stack after bundling. [Figure 3] FIG. 1 is a plan view of a transport system according to a first embodiment. [Figure 4] FIG. [Figure 5] 1 is a partial front cross-sectional view of a gripping device according to a first embodiment. FIG. [Figure 6] FIG. [Figure 7] 2 is a plan view of the gripping device, in which the base plate is shown in a two-dot chain line in a transparent manner. [Figure 8] FIG. 10 is a front view of a gripping device according to a second embodiment. [Figure 9] FIG. [Figure 10] FIG. 10 is a perspective view of a transport system according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, an embodiment of the present invention will be described with reference to the drawings. [First embodiment] (Linen facilities) The conveyance system according to the first embodiment of the present invention is installed in, for example, a linen facility. First, an overview of the linen facility will be described.

[0011] As shown in Figure 1, the linen facility X has a fabric conveying device 11, a fabric spreading device 12, a roll ironer 13, a fabric inspection device 14, and a fabric folding device 15. These devices are connected in series in this order to form a single finishing line.

[0012] The washed cloth is transported by a cloth transport device 11 and fed into a cloth spreading device 12. The cloth fed into the cloth spreading device 12 is spread out in a neat state and ironed by a roll ironer 13. The ironed cloth is inspected by a cloth inspection device 14 and then folded by a cloth folding device 15.

[0013] The fabric folding device 15 stacks a predetermined number of folded fabrics and then discharges them. Hereinafter, a stack of multiple folded fabrics will be referred to as a "fabric stack." The fabric folding device 15 stacks the folded fabrics to form a fabric stack C, which is then discharged.

[0014] A collecting conveyor 16 is provided behind the cloth folding device 15. The cloth stack C discharged from the cloth folding device 15 is placed on the collecting conveyor 16 and transported.

[0015] The finishing line is not limited to a combination of the fabric conveying device 11, fabric unfolding device 12, roll ironer 13, fabric inspection device 14, and fabric folding device 15. Other devices may be added as needed, or some devices may be omitted. The number of finishing lines may be one or multiple. The rear ends of multiple finishing lines may be connected to a common collecting conveyor 16.

[0016] An attitude correcting device 17 is connected to the downstream end of the collecting conveyor 16. The fabric pile C placed on the collecting conveyor 16 may be oriented at an angle to the conveying direction or may be misaligned to the left or right. The attitude correcting device 17 corrects the attitude of the fabric pile C so that it is aligned with the conveying direction.

[0017] A binding machine 18 is connected to the downstream end of the posture correction device 17. The binding machine 18 binds the fabric laminate C. The binding may be with a band such as a PP (polypropylene) band, or with a string. Hereinafter, wire materials such as bands and strings used for binding will be referred to as binding wires. Binding is performed by wrapping the binding wire around the fabric laminate C at least once. The number of times a single fabric laminate C is bound is not particularly limited. A short fabric laminate C may be bound in one place. A long fabric laminate C may be bound in multiple places along the longitudinal direction.

[0018] A recovery conveyor 19 is connected to the downstream end of the bundling machine 18. The bundling pile C of fabrics is transported by the recovery conveyor 19.

[0019] The transport system SS of this embodiment is installed near the downstream side of the recovery conveyor 19. The transport system SS recovers the fabric pile C placed on the recovery conveyor 19 and stacks it on a rack 20.

[0020] Examples of fabrics processed in the linen facility X include rectangular fabrics such as towels, sheets, wrapping cloths, duvet covers, pillowcases, and tablecloths. The fabrics are folded into a rectangular shape in plan view by a fabric folding device 15. There are no particular restrictions on how the fabrics are folded. As shown in FIG. 2(A), a fabric stack C is made by stacking multiple sheets of the same type of fabric folded in the same way, and its shape is roughly a rectangular parallelepiped. There are no particular restrictions on the number of fabrics stacked, and it can be set to a desired number, such as 10, 15, or 20 sheets.

[0021] As shown in FIG. 2(B), since the fabric laminate C is flexible, when it is bound with the binding wire B, the bound portion is squeezed and the front and rear portions thereof become bulged.

[0022] (Transportation system) When the conveying system SS of this embodiment is installed in a linen facility X, it is used to convey a fabric stack C. However, the object conveyed by the conveying system SS is not limited to the fabric stack C, but may be any flexible object wrapped with a binding wire. The fabric stack C is one example of an object conveyed by the conveying system SS. Therefore, in the following description, the object conveyed by the conveying system SS will be referred to as the object C.

[0023] As shown in Figures 3 and 4, the transport system SS has a robot arm 30. The robot arm 30 is an example of a "transport robot" as defined in the claims. The robot arm 30 is provided with a gripping device AA as an end effector. The robot arm 30 has a multi-joint structure and can move the gripping device AA to any position in three-dimensional space. It is also preferable that the robot arm 30 can control the attitude of the gripping device AA by, for example, rotating the gripping device AA.

[0024] For example, the transport system SS uses the gripping device AA to grip the object C placed on the collection conveyor 19. The robot arm 30 moves the object C from the collection conveyor 19 to the rack 20. Preferably, the robot arm 30 adjusts the orientation of the object C according to the shape of the rack 20 and the available space. The gripping device AA releases the object C, and the object C is placed on the rack 20. By repeating this process, multiple objects C can be lined up and stacked within the rack 20. In this way, the transport system SS transports the object C to the desired position by moving the gripping device AA that is gripping the object C.

[0025] The operation of the transport system SS is controlled by a control device (not shown). A computer comprising a CPU, memory, etc. can be used as the control device. Detection results from various sensors may be input to the control device. The control device controls the robot arm 30 and the gripping device AA to perform the desired operation.

[0026] (gripping device) Next, a gripping device AA according to a first embodiment of the present invention will be described. 5, 6, and 7, the gripping device AA has a base plate 40. The base plate 40 is a member that connects to the robot arm 30. The base plate 40 is a plate material that is approximately rectangular in plan view. Hereinafter, a plane that is perpendicular to the base plate 40 and extends along the longitudinal direction at the center in the short side direction is referred to as a center plane O.

[0027] One main surface (upper surface) of the base plate 40 is connected to the robot arm 30. A pair of frame plates 41, 41 is provided in a hanging state on the other main surface (lower surface) of the base plate 40. The pair of frame plates 41, 41 are arranged parallel to the center plane O with a predetermined gap between them.

[0028] The gripping device AA of this embodiment has two gripping units 50A and 50B. The two gripping units 50A and 50B have the same configuration. Therefore, the configuration of the gripping unit 50A will be described below as an example.

[0029] The gripping unit 50A has a pair of pressing members 51, 51. The pressing members 51 are members for pressing the surface of the object C to create a depression. Each pressing member 51 is a rod bent into an approximately V-shape, and is suspended across a pair of frame plates 41, 41, with its upper portion fixed. Each pressing member 51 is arranged so that the apex 51v of the V-shape faces downward. The apex 51v is the part that presses against the surface of the object C. The pair of pressing members 51, 51 are arranged with a predetermined distance between them. The apexes 51v of each pressing member 51 are both located within the central plane O. The distances from the base plate 40 to the apexes 51v of the pair of pressing members 51, 51 are substantially the same (within the range of manufacturing tolerance).

[0030] A first shaft 52 is provided between the pair of frame plates 41, 41. The first shaft 52 is perpendicular to the center plane O. A rotating arm 53 is rotatably supported on the first shaft 52. The rotating arm 53 has a lower arm portion 53b and upper arm portions 53t, 53t that branch off from the lower arm portion 53b. The two upper arm portions 53t, 53t are supported on the first shaft 52.

[0031] A claw member 54 is provided at the lower end of the lower arm portion 53b. The claw member 54 is a member that engages with the binding wire B wound around the object C. The claw member 54 is disposed within the central plane O. Therefore, when the pivot arm 53 is rotated, the claw member 54 rotates within the central plane O around the first shaft 52. By rotating the pivot arm 53 in the forward direction, the claw member 54 can be inserted between the surface of the object C and the binding wire B (solid line in FIG. 5). Furthermore, by rotating the pivot arm 53 in the reverse direction, the claw member 54 can be removed from between the surface of the object C and the binding wire B (double-dashed line in FIG. 5).

[0032] 5, when the claw member 54 is rotated to the lowest point (when the claw member 54 is inserted between the surface of the object C and the binding wire B), the claw member 54 is located between the pair of pressing members 51, 51. The shapes and positions of the claw member 54 and the pressing member 51 are adjusted so that the claw member 54 does not interfere with the pressing member 51 when it rotates.

[0033] A second shaft 55 is provided between the upper ends of the two upper arm portions 53t, 53t. The tip of the rod of an air cylinder 56 is journaled on the second shaft 55. A third shaft 57 is provided between the pair of frame plates 41, 41. The cylinder tube of the air cylinder 56 is journaled on the third shaft 57. The extension and contraction of the air cylinder 56 causes the rotating arm 53 and the claw member 54 to rotate.

[0034] The air cylinder 56 is an example of an "actuator" as set forth in the claims. Other devices, such as a servo motor, may also be used as the actuator. Furthermore, the mechanism is not particularly limited as long as it can insert and remove the claw member 54 between the surface of the object C and the binding wire B. In addition to a mechanism that rotates the claw member 54 using the rotating arm 53, a mechanism that moves the claw member 54 in a reciprocating linear motion may also be used.

[0035] Grip unit 50B has the same configuration as gripping unit 50A. Vertex 51v of pressing member 51 provided in gripping unit 50B is also located within central plane O. Claw member 54 provided in gripping unit 50B also rotates within central plane O. Claw member 54 of gripping unit 50A and claw member 54 of gripping unit 50B are arranged with a predetermined gap between them.

[0036] A distance sensor 60 is attached to the frame plate 41 via a bracket. A non-contact sensor such as a photoelectric sensor or an ultrasonic sensor is preferably used as the distance sensor 60. The distance sensor 60 may be any sensor that can measure the distance between the distance sensor 60 and the surface of the object C. Alternatively, the distance sensor 60 may be a sensor that detects when the distance to the detected object reaches a set distance. In this case, the set distance is set as the distance between the distance sensor 60 and the surface of the object C that is appropriate for inserting the claw member 54 between the surface of the object C and the binding wire B.

[0037] The detection axis of the distance sensor 60 (the optical axis in the case of a photoelectric sensor) is not particularly limited, but it is preferable to set it at the position where the binding wire B is present. In this way, the distance to the object C can be accurately measured without being affected by depressions or bulges in the object C.

[0038] Next, the operation of the gripping device AA will be described. First, the robot arm 30 moves the gripping device AA above the object C. Next, the robot arm 30 lowers the gripping device AA and presses it against the object C. Then, as shown in FIG. 5, the vertex 51v of the pressing member 51 presses the surface of the object C downward. This causes a depression in the surface of the object C. Note that in FIG. 5, the surface of the object C when not pressed by the pressing member 51 is shown by a two-dot chain line, and the surface of the object C when pressed by the pressing member 51 is shown by a solid line.

[0039] The positional relationship between the gripping device AA and the object C is adjusted in advance so that one gripping unit 50A is positioned on one binding wire B and the other gripping unit 50B is positioned on the other binding wire B. The positional relationship between the gripping device AA and the object C is also adjusted so that the binding wire B is positioned between a pair of pressing members 51, 51. Therefore, the pair of pressing members 51, 51 press two locations on either side of the binding wire B, which are in the vicinity of the binding wire B on the surface of the object C, and recess those areas.

[0040] The degree to which the gripping device AA is pressed against the object C is adjusted to an appropriate degree based on the detection result of the distance sensor 60. In other words, the gripping device AA is pressed against the object C so as to be in a state suitable for inserting the claw members 54 between the surface of the object C and the binding wire B.

[0041] Next, the gripping device AA rotates the pivoting arms 53 of the gripping units 50A and 50B in the forward direction to insert the claw members 54 between the surface of the object C and the binding wire B. This causes the claw members 54 to engage with the binding wire B. Here, the surface of the object C is depressed near the binding wire B by the pressing members 51, creating a depression. This makes it easy to insert the claw members 54 between the surface of the object C and the binding wire B. In particular, in this embodiment, the gripping units 50A and 50B each have a pair of pressing members 51, 51, which depression the surface of the object C at two locations on either side of the binding wire B. This makes it easy to create a gap between the surface of the object C and the binding wire B, making it easier to insert the claw members 54. Note that as long as the claw members 54 can be inserted between the surface of the object C and the binding wire B, each of the gripping units 50A and 50B may have only one pressing member 51.

[0042] The degree to which the gripping device AA is pressed against the object C is adjusted based on the detection results of the distance sensor 60, so that the claw member 54 can be positioned appropriately with respect to the binding wire B. This also makes it easier to insert the claw member 54 between the surface of the object C and the binding wire B.

[0043] As described above, the gripping device AA grips the object C by locking the claw members 54 of the gripping units 50A and 50B to the binding wire B. Rather than gripping the object C itself, the claw members 54 grip the object C by locking them to the binding wire B, so even flexible object C can be gripped stably.

[0044] After the gripping device AA has gripped the object C, the robot arm 30 raises the gripping device AA, so that the object C is suspended from the gripping device AA. In this state, the robot arm 30 moves the object C together with the gripping device AA to the desired position. The gripping device AA then rotates the pivot arms 53 of the gripping units 50A and 50B in opposite directions, and removes the claw members 54 from between the surface of the object C and the binding wire B. This releases the object C, allowing it to be placed in the desired position.

[0045] Second Embodiment Next, a gripping device BB according to a second embodiment will be described. The gripping device AA of the first embodiment is configured to suspend the object C by engaging the claw members 54 with the binding wire B wrapped around the object C. Therefore, there is a risk that the object C may swing around the claw members 54 during transport, causing instability. The gripping device BB of the second embodiment has a function to suppress such swinging of the object C.

[0046] As shown in Figures 8 and 9, the gripping device BB of this embodiment has a configuration in which an anti-vibration member 70 is added to the gripping device AA of the first embodiment. For example, the anti-vibration member 70 is a rod arranged parallel to the base plate 40 and the central plane O. The anti-vibration member 70 is fixed to the frame plate 41 via an L-shaped support member. The gripping device BB of this embodiment has two anti-vibration members 70, 70 arranged at a predetermined distance on either side of the central plane O.

[0047] When the claw members 54 of the gripping units 50A, 50B are engaged with the binding wire B, the anti-vibration member 70 comes into contact with the object C. Here, there may be a slight gap between the anti-vibration member 70 and the surface of the object C, so that the anti-vibration member 70 comes into contact with the object C when the object C vibrates. Alternatively, the anti-vibration member 70 may be pressed against the surface of the object C so that it is in constant contact with the surface.

[0048] As described above, when the gripping device BB grips the object C, the anti-sway member 70 comes into contact with the object C, thereby preventing the object C from swinging around the claw member 54. Therefore, the gripping device BB can grip the object C more stably.

[0049] Other Embodiments The transport robot that moves the gripping device AA is not limited to the robot arm 30. For example, as shown in FIG. 10, a palletizer 31 may be used as the transport robot. The illustrated palletizer 31 is operable on three axes, the X-axis, the Y-axis, and the Z-axis, and can move the gripping device AA to any position in three-dimensional space. The palletizer 31 can also rotate the gripping device AA around the Z-axis (vertical line). In addition, the transport robot may be one that moves the gripping device AA three-dimensionally, two-dimensionally, or one-dimensionally.

[0050] The gripping device may have one or more gripping units. The gripping device may have three or more gripping units. The gripping device is not limited to a configuration that grips the object C from the top. The gripping device may grip the object C from the side or the bottom. [Explanation of symbols]

[0051] SS Conveyor System 30 Robot Arm AA gripping device 40 base plate 41 Frame Plate 50A, 50B gripping unit 51 Holding member 53 Swivel arm 54 Claw member 56 Air cylinder 60 Distance Sensor 70 Anti-vibration member

Claims

1. A gripping device for gripping a flexible object around which a binding wire is wound, one or more gripping units; The gripping unit includes: a pressing member that presses a portion of the surface of the object near the binding wire to indent the surface; a claw member that is inserted between the surface of the object pressed by the pressing member and the binding wire and that engages with the binding wire; an actuator for inserting and removing the claw member between the surface of the object and the binding wire; A gripping device characterized by:

2. The gripping unit has a pair of pressing members that press two points on the surface of the object, the two points sandwiching the binding wire.

2. The gripping device according to claim 1.

3. a distance sensor that measures the distance to the object or detects that the distance to the object has reached a distance suitable for inserting the claw member between the surface of the object and the binding wire; 2. The gripping device according to claim 1.

4. and a vibration-preventing member that contacts the object and suppresses vibration of the object.

2. The gripping device according to claim 1.

5. A gripping device according to any one of claims 1 to 4, a transport robot that moves the gripping device. A transport system characterized by:

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