Item transfer device, suction mechanism, and item transfer method

Abstract

To provide an article transfer device which can transfer an article in a state that the article is securely supported from below, and to provide a suction mechanism and an article transfer method.SOLUTION: An article transfer device suctions and transfers an article W and includes: a suction mechanism 30 having a suction part 32 capable of suctioning the article W; a robot which moves the suction mechanism 30 in a movement direction including a lifting direction; and a receiving mechanism 60. The receiving mechanism 60 has a pair of receiving members 61 configured to open in an open state, in which the pair of receiving members 61 opens to a position where the receiving members 61 do not hinder suction operation in which the suction part 32 suctions the article W, or close in a closed state, in which the receiving members 61 receive the article W suctioned and pulled up by the suction part 32 from below, through a scissors mechanism. The suction part 32 suctions the article W in the open state of the pair of receiving members 61. The robot moves the suction mechanism 30 in a state that the pair of receiving members 61 in the closed state receives the article W.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an article transfer device, a suction mechanism, and an article transfer method for transferring an article. [Background technology]

[0002] For example, Patent Document 1 discloses an article transfer device in which a robot performs transfer work by picking up and transferring articles one by one. This article transfer device is equipped with a suction mechanism having a suction portion such as a suction pad at the tip of the robot's arm. The suction mechanism is configured so that the suction portion is tiltable and slidable. The suction mechanism also includes a receiving mechanism that receives from below the article that has been picked up by the suction portion. Then, by having the robot move the suction mechanism, the article transfer device transfers the article that has been picked up by the suction portion while it is supported from below by the four plates of the receiving mechanism. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-92793 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the article transfer device described in Patent Document 1, the four plates of the receiving mechanism are horizontally arranged flat plates, making it easy for articles to slip during transfer. Therefore, the suction part maintains the suction state by using the suction force generated when the article is picked up during transfer. The pad portion constituting the suction part is made of a rubber material or a synthetic resin material with rubber elasticity. When the suction part is in a suction state, a high negative pressure is applied to the pad portion. As a result, the suction part deteriorates more quickly the more frequently and for longer periods of time. In the article transfer device described in Patent Document 1, since the receiving mechanism is in a state where it receives articles, it is possible to transfer articles with the suction of the suction part released. However, because the four plates of the receiving mechanism only support the articles from below, it is difficult to transfer articles with the suction of the suction part released or weakened. Furthermore, even if the suction part maintains its suction, other factors, such as the shaking of the articles during transfer, may make it difficult to stably hold the articles during transfer. Therefore, there is a demand for an article transfer device that can transfer articles while firmly supporting them from below. [Means for solving the problem]

[0005] The means for solving the above problems and their effects will be described below. An article transfer device that solves the above problem is an article transfer device that adsorbs and transfers an article, and includes a suction mechanism having an adsorption portion capable of adsorbing the article, and a movement mechanism that moves the suction mechanism in a movement direction including a lifting direction. The suction mechanism includes a receiving mechanism having a pair of receiving members that can be opened and closed via a scissors mechanism between an open state in which the adsorption portion opens to a position that does not interfere with the adsorption operation of the adsorption portion to adsorb the article, and a closed state in which the adsorption portion adsorbs and lifts the article from below. The adsorption portion adsorbs the article when the pair of receiving members are in the open state, and the movement mechanism moves the suction mechanism when the pair of receiving members in the closed state receive the article. Note that the closed state does not necessarily mean that the pair of receiving members are closed to a position where they contact each other; the pair of receiving members may be spaced apart from each other and moved relative to each other in the closing direction compared to the open state. In other words, as long as the pair of receiving members can receive an article, they may be spaced apart or in contact with each other in the closed state, as long as the distance between them is small enough to allow the pair of receiving members to receive the article compared to the open state.

[0006] With this configuration, the suction unit suctions the item when the pair of receiving members is in the open position, and the moving mechanism moves the suction unit when the pair of receiving members is in the closed position and receives the item. Therefore, the item can be transported while being firmly supported by the receiving members from below. For example, compared to a configuration in which the item is transported while being adsorbed to the suction unit by the suction force generated when the item is picked up, it is also possible to suppress deterioration of the suction unit.

[0007] In the above-described article transfer device, the receiving mechanism may include a drive unit that opens and closes the pair of receiving members. According to this configuration, the pair of receiving members can be opened and closed by the drive unit at the required timing. For example, the pair of receiving members can be opened while the suction unit is suctioning the article, and closed after the article has been suctioned and lifted up.

[0008] In the above-described article transfer device, the receiving mechanism may close the pair of receiving members after the suction portion has lifted up the article. According to this configuration, the pair of receiving members close after the suction portions have lifted up the article, so that the closed pair of receiving members can receive the article.

[0009] In the above-mentioned item transfer device, the receiving mechanism closes the pair of receiving members, and then places the item on the pair of receiving members by moving the suction portion and the receiving members relative to each other in a direction vertically approaching each other, and then moves the suction portion and the receiving members relative to each other in a direction vertically separating them from each other, with the suction portion and the receiving members having released their suction, and the moving mechanism may move the suction mechanism when the suction portion has released its suction and the pair of receiving members are receiving the item from below.

[0010] According to this configuration, the suction by the suction part is released and the article can be transferred in a state in which the article is received by the receiving member, so deterioration such as wear of the suction part can be suppressed. The article transfer device includes a tilting mechanism that supports the suction portion so that it can be tilted, and a locking mechanism that can switch the tilting mechanism between an unlocked state that allows the suction portion to tilt and a locked state that locks the suction portion in a horizontal position, and after closing the pair of receiving members, with the suction portion locked in a horizontal position, the suction portion and the pair of receiving members may move relative to each other in a direction vertically approaching each other, thereby placing the article on the pair of receiving members in the closed state.

[0011] With this configuration, the tilting mechanism is locked, allowing the article to be placed on the pair of receiving members while being maintained in a horizontal position. For example, compared to a configuration in which the tilting mechanism is unlocked and the article is placed on the pair of receiving members in an inclined position that is inclined from the horizontal, this configuration makes it less likely that the article will shift in position or posture when placed at the destination. In other words, the article can be placed in an appropriate position with minimal shifting and in an appropriate position.

[0012] In the above-mentioned item transfer device, during the suction operation of suctioning the item, the suction section may be lowered from a raised position to a suction position using a first driving force, and when the suction section at the suction position descends until it has adsorbed the item, the suction section may be lowered using a second driving force weaker than the first driving force, and when the item adsorbed and pulled up by the suction section is placed on the pair of receiving members in the closed state, the suction section may be lowered using the second driving force.

[0013] With this configuration, before adsorbing an item, the adsorption part descends to the adsorption position at high speed with a first driving force, and when the adsorption part in the descending position adsorbs an item, the adsorption part applies weak pressure to the item. Furthermore, when placing the item on the receiving member, the adsorption part descends with a second driving force that is smaller than the first driving force, so that the adsorption part only needs to apply a small pressing force to the item when placing it on the receiving member.

[0014] In the above-mentioned item transfer device, the suction section is configured to be able to adsorb the item with a suction airflow using a blower as a negative pressure source, and the suction mechanism may have a flow rate adjustment section that can adjust the negative pressure acting on the item when it is adsorbed to the suction section by the leakage flow rate of the suction airflow.

[0015] This configuration allows the suction airflow, which determines the suction force acting on the article adsorbed to the suction section, to be adjusted according to the strength of the article. Therefore, it is possible to ensure reliable adsorption for multiple types of articles with different strengths while preventing damage to the article. For example, if the article is a bag containing contents, it is possible to prevent the bag from being torn by excessive suction force.

[0016] The above-mentioned item transfer device may be provided with a detection unit capable of detecting excessive negative pressure in which the negative pressure acting on the suction unit exceeds a negative pressure threshold, and when the detection unit detects the excessive negative pressure, the flow rate adjustment unit may adjust the negative pressure acting on the item to a smaller value by increasing the leakage flow rate.

[0017] With this configuration, it is possible to prevent an excessive negative pressure from being exerted on an article for some reason, while the suction airflow is adjusted so that the negative pressure exerted on the suction section is a negative pressure appropriate to the type of article.

[0018] In the above-mentioned item transfer device, the pair of receiving members may have a plurality of hook members arranged at intervals in a first direction at their tip end portions, and may be equipped with a spacing change mechanism configured to change the spacing between the plurality of hook members.

[0019] According to this configuration, the pair of receiving members receive articles using multiple hook members, allowing for more reliable reception of articles than receiving members without hook members. Furthermore, when removing or placing articles on the roller conveyor, the hook members can be inserted into the gaps between the rollers. For example, by changing the spacing of the hook members according to the spacing of the rollers of the roller conveyor, the hook members can be partially inserted into the gaps between the rollers. This allows for placing articles on the roller conveyor while the pair of receiving members is in a closed state, or for removing articles by lifting them up after the pair of receiving members close.

[0020] In the above-mentioned item transfer device, when the item adsorbed by the suction section is placed on a roller conveyor, the moving mechanism may lower the suction mechanism to a loading position where the hook member is partially inserted between the rollers of the roller conveyor, and then perform an suction release operation in which the suction section releases the suction of the item, and an opening operation in which the receiving mechanism opens the pair of receiving members.

[0021] With this configuration, the pair of receiving members can receive the item until it is placed, or can receive the item for as long as possible until just before it is placed. Therefore, even if the item comes off the suction part when it is placed, the impact of the drop on the item can be avoided or reduced.

[0022] In the above-mentioned item transfer device, when the suction section picks up the item on the roller conveyor, the moving mechanism lowers the suction mechanism to a pick-up position where it can suction up the item on the roller conveyor while the pair of receiving members are in an open state, and then performs an suction operation in which the suction section suctions up the item, and a closing operation in which the receiving mechanism closes the pair of receiving members, and during the closing operation, the hook member may be partially inserted between the rollers of the roller conveyor.

[0023] According to this configuration, the article adsorbed by the adsorption portion can be lifted up from the roller conveyor when the pair of receiving members are in the closed state. The suction mechanism that solves the above problem comprises a mounting part that can be attached to an arm of the articulated robot as the moving mechanism, a suction part that can suction an item, and a receiving mechanism having a pair of receiving members that can be opened and closed via a scissors mechanism between an open state in which the suction part opens to a position that does not interfere with the suction action of suctioning the item, and a closed state in which the suction part receives the item from below after suctioning and lifting it up, and the suction part suctions the item when the pair of receiving members are open, and is in the closed state in which the pair of receiving members receive the item from below during the process in which the articulated robot transfers the item.

[0024] This configuration can suppress deterioration of the suction portion compared to a configuration in which the article is transported while being suctioned by the suction portion. An article transfer method that solves the above problem is an article transfer method for adsorbing and transferring an article, comprising: an adsorption mechanism having an adsorption portion capable of adsorbing the article; and a moving mechanism that moves the adsorption mechanism in a moving direction including a lifting and lowering direction; the adsorption mechanism comprises a receiving mechanism having a pair of receiving members that are configured to be openable and closable via a scissors mechanism between an open state in which the adsorption portion opens to a position that does not interfere with the adsorption operation of the adsorption portion to adsorb the article, and a closed state in which the adsorption portion receives the article from below after adsorption and lifting it up; the method comprises an adsorption step in which the adsorption portion adsorbs and lifts up the article when the pair of receiving members are in the open state; a receiving step in which the adsorption portion and the receiving members move relatively in a direction approaching each other in the vertical direction after the pair of receiving members close to each other in the closed state, so that the pair of receiving members in the closed state receive the article; and a transport step in which the moving mechanism moves the adsorption mechanism when the pair of receiving members in the closed state have received the article.

[0025] This method allows the article to be transported while being firmly supported from below. [Effects of the Invention]

[0026] According to the present invention, an article can be transported while being firmly supported from below. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a schematic front view showing an article transfer device according to the first embodiment. [Figure 2] FIG. 2 is a front view showing the suction mechanism. [Figure 3] FIG. 3 is a side view showing the suction mechanism in an open state. [Figure 4] FIG. 4 is a side view showing the suction mechanism in a closed state. [Figure 5] FIG. 5 is a front view showing the slide mechanism in the locked state. [Figure 6] FIG. 6 is a front view showing the slide mechanism in the slide-permitted state. [Figure 7]FIG. 7 is a side view showing the tilting mechanism in the locked state. [Figure 8] FIG. 8 is a side view showing the tilting mechanism in the tilting permitted state. [Figure 9] FIG. 9 is a block diagram showing the electrical configuration of the transfer device. [Figure 10] FIG. 10 is a schematic diagram showing the transfer operation of the transfer device. [Figure 11] FIG. 11 is a schematic diagram showing the transfer operation of the transfer device. [Figure 12] FIG. 12 is a schematic diagram showing the transfer operation of the transfer device. [Figure 13] FIG. 13 is a schematic diagram showing the transfer operation of the transfer device. [Figure 14] FIG. 14 is a schematic diagram showing the transfer operation of the transfer device. [Figure 15] FIG. 15 is a schematic diagram showing the transfer operation of the transfer device. [Figure 16] FIG. 16 is a schematic diagram showing the transfer operation of the transfer device. [Figure 17] FIG. 17 is a schematic diagram showing the transfer operation of the transfer device. [Figure 18] FIG. 18 is a front view showing the suction mechanism in the open state in the second embodiment. [Figure 19] FIG. 19 is a side view showing the suction mechanism in the open state. [Figure 20] FIG. 20 is a front view showing the suction mechanism in a closed state. [Figure 21] FIG. 21 is a side view showing the suction mechanism in a closed state. [Figure 22] FIG. 22 is a side view showing the tilting mechanism and the locking mechanism in the tilting permitted state. [Figure 23] FIG. 23 is a front view showing the receiving portion. [Figure 24] FIG. 24 is a circuit diagram showing a pneumatic circuit in the transfer device. [Figure 25] FIG. 25 is a block diagram showing the electrical configuration of the transfer device. [Figure 26]FIG. 26 is a schematic diagram showing the transfer operation when the transfer device picks up the load. [Figure 27] FIG. 27 is a schematic diagram showing the transfer operation when the transfer device picks up the load. [Figure 28] FIG. 28 is a schematic diagram showing the transfer operation when the transfer device picks up the load. [Figure 29] FIG. 29 is a schematic diagram showing the transfer operation when the transfer device picks up the load. [Figure 30] FIG. 30 is a schematic diagram showing the transfer operation when the transfer device picks up and places a load. [Figure 31] FIG. 31 is a schematic diagram showing the transfer operation when placing a load on the transfer device. [Figure 32] FIG. 32 is a schematic diagram showing the transfer operation when placing a load on the transfer device. [Figure 33] FIG. 33 is a schematic diagram showing the transfer operation when placing a load on the transfer device. [Figure 34] FIG. 34 is a schematic diagram showing the transfer operation of the transfer device in the modified example. [Figure 35] FIG. 35 is a schematic diagram showing the transfer operation of the transfer device. [Figure 36] FIG. 36 is a schematic diagram showing the transfer operation of the transfer device. [Figure 37] FIG. 37 is a schematic diagram showing the transfer operation of the transfer device. DETAILED DESCRIPTION OF THE INVENTION

[0028] (First embodiment) A first embodiment of an article transfer device will be described below with reference to the drawings. In FIG. 1, the two directions defining the placement surface on which an article W (workpiece) to be transferred by the article transfer device 10 is placed are the X direction and the Y direction, respectively, and the direction intersecting the X direction and the Y direction and parallel to the direction of gravity is the height direction Z. In this example, the loading surface (surface of the pallet P) on which the articles W are stacked in multiple layers is referred to as the placement surface Pa. The height direction Z is a direction perpendicular to the placement surface Pa on which the articles W are to be placed. The direction perpendicular to the height direction Z is referred to as the horizontal direction. In this example, the horizontal direction is a direction parallel to the placement surface Pa.

[0029] As shown in FIG. 1 , an article transfer device 10 (hereinafter simply referred to as "transfer device 10") performs a transfer operation (de-stacking operation) in which an article W at a pickup position where the article should be picked up is picked up one by one from a group of articles where multiple articles W are stacked on a pallet P, carries the article W to a conveyor 12, and places the article W at a placement position on the conveyor 12 where the article should be placed by releasing the suction. The transfer device 10 also performs a transfer operation (stacking operation) in which the transfer device 10 picks up the article W at the pickup position conveyed by the conveyor 12 one by one and carries it to the pallet P, and releases the suction to place the article W at a placement position on the pallet P or above other articles W stacked on the pallet P. In both the de-stacking operation and the stacking operation, the transfer device 10 performs a transfer operation in which it picks up and grasps the article W at the pickup position, transports the article W from the pickup position to a placement position, and releases the suction to place the article W at the placement position.

[0030] As shown in FIG. 1, the transfer device 10 includes a robot 20 as an example of a moving mechanism that moves a suction mechanism 30 that suctions an item W, and the suction mechanism 30 attached to the tip of a robot arm 23. A pallet P loaded with a group of items is placed at a predetermined position within the working range of the robot 20 shown in FIG. 1 by a transport conveyor or an electric cargo handling vehicle (neither of which are shown). The item W in this embodiment is, for example, a bag. The bag may contain, for example, powder or granular material (e.g., grains). Specifically, the contents of the bag may be food powder (such as flour) or granular material (such as beans), or industrial powder or granular material (e.g., cement powder). The bag may also contain liquid or gas.

[0031] The transfer device 10 is equipped with an imaging device 90 including a camera 91 capable of capturing images of the object W to be picked up from above in the height direction Z downward. The camera 91 of the imaging device 90 is attached to a predetermined position near the ceiling of a factory or the like, a predetermined position on the robot arm 23, or a predetermined position on the suction mechanism 30. In the example of FIG. 1, the camera 91 is located at a predetermined height near the ceiling. The transfer device 10 performs image analysis processing to analyze images of the group of objects captured by the camera 91 from directly above, thereby acquiring at least one of position information including the XY coordinate position and height position of the suction surface, which is the upper surface to which the object W is picked up at the pick-up position, and position information including the height position of the placement surface on which the object W is placed at the placement position. The transfer device 10 acquires at least one of the pick-up position and the placement position based on the acquired position information. Note that in the example of FIG. 1, the placement position is a predetermined position on the conveyor 12, so pre-entered, fixed position information is used.

[0032] As shown in Fig. 1, the robot 20 is an articulated industrial robot including a base 21 arranged on the upper surface of an installation stand 13 installed on the floor, a rotating base 22 that can rotate about a vertical axis relative to the base 21, and an articulated robot arm 23 supported by the rotating base 22. In other words, the robot 20 is an articulated robot. A suction mechanism 30 is attached to the tip of the robot arm 23. The robot 20 performs a transfer operation (de-stacking operation) in which the suction mechanism 30 picks up and grasps the uppermost article W of a group of articles on a pallet P, and places the grasped article W at a predetermined position (loading position) on the conveyor 12.

[0033] The robot arm 23 rotates about its axis together with the rotating table 22 by the power of a drive source 25 of a drive mechanism 24 disposed on the side of the base 21. The robot arm 23 also has a plurality of arm sections 23A to 23C connected so that the angle can be changed. The drive source 25 is, for example, an electric motor or an electric cylinder. The angles of the plurality of arm sections 23A to 23C are adjusted via a link mechanism (not shown) when the drive mechanism 24 is driven. The suction mechanism 30 is supported in a suspended state at the tip of the robot arm 23 so as to be rotatable about its axis via a rotating section 27 powered by a motor 26.

[0034] As shown in Fig. 1, the suction mechanism 30 has a suction section 32 that can suction an item W. The suction section 32 can suction and release the item W. The suction mechanism 30 is connected to a negative pressure source of an air pressure circuit (both not shown) through piping (not shown). The control section 100 controls an electromagnetic on-off valve (not shown) connected midway through the piping, thereby controlling the suction and release of the item W in the suction section 32.

[0035] 1, the suction mechanism 30 includes a receiving mechanism 60 that receives from below the article W picked up by the suction section 32. The receiving mechanism 60 has a pair of receiving members 61 (only one of the receiving members 61, the front one, is shown in FIG. 1) that receive the article W. The receiving mechanism 60 includes a pair of opening / closing cylinders 62 as an example of a drive unit that opens and closes the pair of receiving members 61, and a pair of link mechanisms 63 that convert the extension and contraction drive of the pair of opening / closing cylinders 62 into the opening and closing movement of the pair of receiving members 61.

[0036] 1, the robot 20 transfers the article W in a state in which the pair of receiving members 61 receives the article W. Therefore, during transfer by the robot 20, the article W is separated from the suction portion 32. Details of the receiving mechanism 60 will be described later.

[0037] <Detailed configuration of the adsorption mechanism 30> Next, the detailed configuration of the suction mechanism 30 will be described with reference to Fig. 2. Note that the orientation of the suction mechanism 30 changes when the suction mechanism 30 rotates about its axis, but in the following description, the direction in which the pair of link mechanisms 63 face each other is referred to as the X direction, and the direction perpendicular to the X and Z directions is referred to as the Y direction.

[0038] 2, as described above, the suction mechanism 30 is attached to the tip of the robot arm 23. The suction mechanism 30 includes a mechanism main body 31 including a skeletal frame and the like. The mechanism main body 31 includes an attachment portion 33 that can be attached to the tip of the robot arm 23, a support portion 34 fixed to the lower end of the attachment portion 33, and an elevating mechanism 35 that supports the suction portion 32 so that it can be raised and lowered relative to the support portion 34.

[0039] The lifting mechanism 35 includes two vertical lifting cylinders 36 (only the front one is shown in FIG. 2 ) whose axes are parallel to the height direction Z. The lifting cylinders 36 are arranged facing downward with the rod side facing downward, and the lower end of the piston rod 36a is fixed to the lifting member 37. When the two lifting cylinders 36 are driven to extend and retract, the suction part 32 supported on the lower side of the lifting member 37 moves up and down.

[0040] Between the lifting member 37 and the suction part 32, there are interposed a tilting mechanism 40 that supports the suction part 32 so that it can tilt, and a slide mechanism 50 that supports the suction part 32 so that it can slide. The tilting mechanism 40 includes a joint mechanism 41 that supports the suction part 32 so that it can tilt. The joint mechanism 41 is formed, for example, by a cross joint.

[0041] 2, the joint mechanism 41 has a first shaft 42 (X-axis) whose axis is parallel to the X-direction, a second shaft 43 (Y-axis) whose axis is parallel to the Y-direction, and a connecting member 44 that holds the first and second shafts 42, 43. The connecting member 44 connects the first and second shafts 42, 43 so that they intersect at an angle of 90° and are independently rotatable about their axes. A block 45 protrudes from the upper end of the connecting member 44.

[0042] 2, a swinging member 48 extending upward from the upper surface of the suction part 32 is connected to the joint mechanism 41 in a state in which it can rotate about a second axis 43. The suction part 32 is supported via the joint mechanism 41 in a state in which it can tilt about two axes, X and Y. That is, the suction part 32 can tilt about the X axis, centered on the first axis 42, and about the Y axis, centered on the second axis 43.

[0043] Here, the connecting member 44 is supported so as to be slidable in the X direction along the first shaft 42. This forms a slide mechanism 50 that slides the suction portion 32 in the X direction. The slide mechanism 50 includes a pair of regulating members 51 that function as stoppers that regulate the range in which the connecting member 44 slides along the first shaft 42. Both ends of the first shaft 42 are fixed to the pair of regulating members 51.

[0044] The connecting member 44 functions as a slider that is slidable in the sliding direction X along the first axis 42. The pair of regulating members 51 define the end positions of the moving range of the connecting member 44 (slider) in the sliding direction X. That is, the connecting member 44 moves along the first axis 42, and when it hits the regulating members 51, further movement is restricted. Therefore, the suction unit 32 is supported in a state in which it can tilt in two directions around the first axis 42 (X axis) and the second axis 43 (Y axis) relative to the lifting member 37, and can slide in the X direction along the first axis 42 within a predetermined range.

[0045] As shown in FIG. 2, the suction section 32 includes a negative pressure generating unit 38 and a suction pad 39. The suction pad 39 is located at the lower end of the suction section 32. The suction pad 39 has a ring-shaped pad section 39a at its lower end. The pad section 39a has, for example, an oval ring shape. The pad section 39a is made of, for example, an airtight elastic material. The pad section 39a may be made of rubber or a synthetic resin made of an airtight and elastic porous material (for example, a foam material). A suction port 39b surrounded by the pad section 39a is opened on the lower surface of the suction pad 39.

[0046] The negative pressure generating unit 38 generates a negative pressure at the suction port 39b of the suction pad 39. The negative pressure generating unit 38 is, for example, an ejector. The negative pressure generating unit 38 is fixed to a regulating plate 49 that is fixed to the lower part of the swinging member 48. The negative pressure generating unit 38 generates and releases a negative pressure at the suction port 39b.

[0047] The adsorption part 32 can be raised and lowered relative to the support part 34 by the lifting mechanism 35, can be tilted relative to the lifting member 37 by the tilting mechanism 40 via the joint mechanism 41, and the tilting fulcrum can be slid in the X direction by the slide mechanism 50.

[0048] <Return mechanism 55> In addition, a return mechanism 55 is provided between the lifting member 37 and the suction part 32. The return mechanism 55 has a tilt return function that returns the suction part 32 tilted by the tilting mechanism 40 from the tilted posture to a horizontal posture, and a slide return function that returns the suction part 32 slid by the slide mechanism 50 to a center position in the slide direction X. The return mechanism 55 in this embodiment includes a lock mechanism 46 that can be switched between an unlocked state that allows the suction part 32 to tilt by the tilting mechanism 40 and a locked state that locks the suction part 32 in the horizontal posture. The return mechanism 55 also includes a center return mechanism 56 that returns the suction part 32 to the center position in the slide direction. In this embodiment, the suction part 32 returned by the return mechanism 55 is locked in the center position, which is the return position in the slide direction X, and is locked in the horizontal posture, which is the return posture within the tilt angle range.

[0049] That is, the center return mechanism 56 switches between a locked state in which the suction part 32 is locked at the center position so that it cannot slide, and an unlocked state in which the suction part 32 is allowed to slide in the sliding direction X. In addition to the return function of returning the suction part 32 to the center position, the center return mechanism 56 also functions as a locking mechanism that locks the suction part 32 at the center position so that it cannot slide. The detailed configurations of the center return mechanism 56 and the locking mechanism 46 will be described later.

[0050] As shown in Fig. 2, the receiving mechanism 60 has the pair of receiving members 61 and a pair of opening / closing cylinders 62 that open and close the pair of receiving members 61. The opening / closing cylinders 62 are arranged with the rod side facing downward. The tip end of the rod 62a of the opening / closing cylinder 62 is connected to the base end of the pair of receiving members 61 via a link mechanism 63 so that power can be transmitted. When the pair of opening / closing cylinders 62 are driven to extend and retract, the pair of receiving members 61 open and close between an open state (open position) shown in Fig. 3 in which the pair of receiving members 61 cannot hold an article W, and a closed state (holding position) shown in Fig. 4 in which the pair of receiving members 61 can hold an article W.

[0051] <Configuration of receiving mechanism 60> Next, the configuration of the receiving mechanism 60 will be described in detail with reference to Figures 2 to 4. Note that some components such as the return mechanism 55 are omitted in Figures 3 and 4.

[0052] 2 to 4, a pair of opening / closing cylinders 62 and a pair of link mechanisms 63 are arranged on both sides of the receiving mechanism 60 in the X direction, at the center position in the Y direction. The link mechanism 63 is configured by a pantograph mechanism having one fixed end fixed to the support part 34 and two movable end parts. A receiving member 61 is fixed to the two movable end parts of the link mechanism 63.

[0053] 3 and 4, the suction mechanism 30 has a support plate 64 extending downward from the center in the Y direction of the support part 34. The support plate 64 has a guide groove 64a extending in the Z direction along the movement path of the rod of the opening / closing cylinder 62.

[0054] As shown in FIGS. 2 to 4, the link mechanism 63 has a pair of first link members 65, a pair of second link members 66, a fixed shaft 67, a connecting shaft 68, and a movable shaft 69. The fixed shaft 67 is fixed to a predetermined position of the lifting member 37. One end of each of the pair of first link members 65 is rotatably supported by the fixed shaft 67. The other end of each of the pair of first link members 65 is rotatably connected to one end of a second link member 66 via the connecting shaft 68. The pair of second link members 66 intersect and are rotatably connected about a movable shaft 69 located at the intersection. The tip end of the rod 62a of the opening / closing cylinder 62 is connected to the movable shaft 69.

[0055] When the opening / closing cylinder 62 is extended in the open state shown in Fig. 3, the movable shaft 69 descends along the guide groove 64a. This causes the link mechanism 63 to move from the folded state shown in Fig. 3 to the unfolded state shown in Fig. 4. As a result, the pair of receiving members 61 close from the open state to the closed state.

[0056] When the opening / closing cylinder 62 is extended in the open state shown in Fig. 3, the movable shaft 69 descends along the guide groove 64a. This causes the link mechanism 63 to move from the folded state shown in Fig. 3 to the unfolded state shown in Fig. 4. As a result, the pair of receiving members 61 close from the open state to the closed state.

[0057] On the other hand, when the opening / closing cylinder 62 is driven to contract in the closed state shown in Fig. 4, the movable shaft 69 rises along the guide groove 64a. Then, the link mechanism 63 operates from the unfolded state shown in Fig. 4 to the folded state shown in Fig. 3. As a result, the pair of receiving members 61 opens from the closed state to the open state.

[0058] In this way, the pair of receiving members 61 are configured to be openable and closable between an open state in which they open to a position that does not interfere with the suction operation of the suction portions 32 to suction the article W, and a closed state in which the suction portions 32 receive the article W from below after suction and lifting it up. The link mechanism 63 is, for example, a scissors mechanism. The pair of receiving members 61 are configured to be openable and closable via the scissors mechanism. The link mechanism 63 may also be a pantograph mechanism including a scissors mechanism.

[0059] The second link member 66 constitutes the base of the receiving member 61, which has a substantially L-shape in side view as shown in FIG. 3. That is, the receiving member 61 has the second link member 66 and a receiving portion 70 fixed to the other end of the second link member 66. The second link member 66 and the receiving portion 70 form a predetermined angle (substantially a right angle in the example of FIG. 3). By forming the predetermined angle, the pair of receiving portions 70 are set to a required distance when the pair of receiving members 61 are opened and closed. That is, when the pair of receiving members 61 are in the open state shown in FIG. 3, the pair of receiving portions 70 are spaced apart by a distance (hereinafter referred to as the "first distance") that ensures a path for lifting the article W. Also, when the pair of receiving members 61 are in the closed state shown in FIG. 4, the pair of receiving portions 70 approach a distance (hereinafter referred to as the "second distance") that allows them to receive the article W lowered by the suction portion 32.

[0060] As shown in Fig. 3, the first interval is wider than the dimension of the short side of the article W. As shown in Fig. 4, the second interval is narrower than the dimension of the short side of the article W. When there are multiple sizes of the article W, the first interval is wider than the dimension of the short side of a large-sized article W. The second interval is narrower than the dimension of the short side of a small-sized article W.

[0061] As shown in Fig. 3, when the pair of receiving members 61 are in an open state, there is no interference between the suction portion 32 and the article W that the suction portion 32 has adsorbed during the suction operation of the suction portion 32. When the pair of receiving members 61 are in an open state, the suction portion 32 descends as the lifting cylinder 36 is extended, and adsorbs the article W. After adsorbing the article W, the suction portion 32 ascends as the lifting cylinder 36 is retracted, and pulls up the article W to the position shown in Fig. 3.

[0062] 4, the receiving mechanism 60 closes the pair of receiving members 61 after the suction unit 32 lifts up the article W. That is, after the suction unit 32 lifts up the article W1 as shown in the figure, the pair of opening / closing cylinders 62 are driven to contract, and the pair of receiving members 61 closes.

[0063] After closing the pair of receiving members 61, the receiving mechanism 60 moves the suction part 32 and the receiving members 61 relative to each other in the vertical direction Z, thereby placing the item W on the upper surfaces of the pair of receiving members 61. In this embodiment, the lifting cylinder 36 is then extended, causing the suction part 32 to descend to the position of item W2 shown in FIG. 4, and placing the item W on the upper surfaces of the pair of receiving members 61. At this time, the item W1 is placed on the pair of receiving parts 70, which are inclined so that they approach each other as they move downward. In particular, if the item W is a bag, the bag will deform due to its own weight and will come into contact with the pair of receiving parts 70 over a wider area than in the state shown in FIG. 4.

[0064] Thereafter, the adsorption part 32, from which adsorption has been released, and the receiving member 61 are relatively moved away from each other in the vertical direction Z. That is, the lifting cylinder 36 is driven to contract, and only the adsorption part 32 is raised to the raised position shown in FIG.

[0065] 1, the robot 20 moves the suction mechanism 30 in a state where the pair of receiving members 61 in the closed state receive the article W. In particular, in this embodiment, the robot 20 moves the suction mechanism 30 in a state where the suction of the suction portion 32 is released and the pair of receiving members 61 receive the article W from below.

[0066] 2, the receiving portion 70 has a plurality of round pipes 70a, including a round pipe 70a that forms the lower end of the generally U-shaped member and another round pipe 70a that is arranged parallel to the first round pipe 70a. The pair of receiving members 61 receives the article W at the portion where the plurality of round pipes 70a are arranged. Therefore, even if the article W is a bag that deforms under its own weight or even if the article W comes in a variety of sizes, the article W can be received by one or more pairs of round pipes 70a.

[0067] 2, a first electromagnetic on-off valve 71, a second electromagnetic on-off valve 72, and a first sensor 73 are attached to predetermined locations on the mechanism body 31 of the suction mechanism 30. The first electromagnetic on-off valve 71 is connected to the lift cylinder 36 through piping (not shown). The second electromagnetic on-off valve 72 is connected to the on-off cylinder 62 through piping (not shown). The first sensor 73 detects the pressure of the lift cylinder 36.

[0068] <Detailed configuration of the center return mechanism 56> Next, the configuration of the center return mechanism 56 will be described in detail with reference to Figures 5 and 6. Figure 5 shows a locked state in which the suction part 32 is locked in the center position, and Figure 6 shows an unlocked state. Note that part of the lock mechanism 46 is omitted in Figures 5 and 6.

[0069] As shown in FIGS. 5 and 6 , the center return mechanism 56 includes a block 45 at the upper end of the connecting member 44, which functions as a slider, and a pair of first cylinders 57 positioned opposite each other in the X direction, sandwiching the block 45. The center return mechanism 56 is driven between a locked position (shown in FIG. 5 ) that does not allow the suction unit 32 to slide, and a slide-permitted position (shown in FIG. 6 ) that allows the suction unit 32 to slide using the slide mechanism 50. When the pair of first cylinders 57 is extended, the tips of the pair of rods 57a sandwich the block 45 from both sides in the X direction, locking the tilting fulcrum of the suction unit 32 at the center position so that it cannot slide. When the first cylinders 57 are retracted, the pair of rods 57a are retracted in directions away from each other, allowing the block 45 to slide freely in the X direction. In other words, the tilting fulcrum of the suction unit 32 is allowed to slide freely in the X direction.

[0070] At this time, if tilting of the suction part 32 is permitted, when the suction part 32 adsorbs the article W, it tilts in a direction corresponding to the inclination of the adsorbed surface of the article W. Therefore, depending on the inclination of the article W, the suction part 32 tilts from a horizontal position in the counterclockwise direction indicated by the solid line in FIG. 6 or in the clockwise direction indicated by the two-dot chain line in the same figure. Therefore, even if the article W is tilted, the suction part 32 can reliably adsorb the article W by pressing the entire surface of the suction pad 39 against the adsorbed surface of the article W. Furthermore, the tilting fulcrum of the suction part 32 slides in the X direction during the tilting process, thereby ensuring a large tilting angle.

[0071] <Detailed configuration of lock mechanism 46> Next, the configuration of the locking mechanism 46 will be described in detail with reference to Figures 7 and 8. Figure 7 shows a locked state in which the suction part 32 is locked in a horizontal position, and Figure 8 shows an unlocked state in which the suction part 32 can tilt.

[0072] As shown in FIGS. 7 and 8, the locking mechanism 46 includes a restricting plate 49 fixed to the upper end of the suction part 32, and a pair of second cylinders 47 arranged facing downward and opposite the restricting plate 49. As shown in FIG. 7, when the second cylinders 47 are extended, pressing parts 47a fixed to the tips of the pair of rods simultaneously press both ends of the restricting plate 49 in the Y direction from above, thereby maintaining the restricting plate 49 in a horizontal position. Therefore, the suction part 32 is maintained in a horizontal position in a locked state in which it cannot tilt around the first axis 42 (X axis). In this embodiment, the suction part 32 is locked in a horizontal position while the robot 20 is transferring the article W.

[0073] 8, when the second cylinder 47 is contracted, the pressing portions 47a fixed to the tip ends of the rods move away from the upper surface of the regulating plate 49, allowing the suction portion 32 to tilt. Therefore, if the article W is tilted, the suction portion 32 is pressed against the tilted suction target surface of the article W, and tilts in the direction of the tilt of the suction target surface of the article W. Therefore, depending on the tilt of the article W, the suction portion 32 tilts from the horizontal position in the counterclockwise direction indicated by the solid line in FIG. 8 or in the clockwise direction indicated by the two-dot chain line in the same figure. Therefore, even with a tilted article W, the suction openings 39b of the suction pad 39 can be pressed entirely against the suction target surface of the article W to suction the article W.

[0074] <Electrical configuration of the article transfer device> Next, the electrical configuration of the transfer device 10 will be described with reference to Fig. 9. As shown in Fig. 9, the transfer device 10 includes a control unit 100 that performs overall control of the transfer device 10. The control unit 100 incorporates a computer 110 (microprocessor) and a memory 120. The memory 120 stores, for example, a program for transfer control. The control unit 100 controls the transfer device 10 by the computer 110 executing the program.

[0075] 9, the control unit 100 is electrically connected to an input system including an input unit 15 operated by an operator, a camera 91, a first sensor 73, a second sensor 96, and a third sensor 97. The first sensor 73 detects that the suction unit 32 has adsorbed an article W. The second sensor 96 detects the lifting and lowering state of the suction unit 32. The third sensor 97 detects the open / closed state of a pair of receiving members 61 that constitute the receiving mechanism 60.

[0076] The input unit 15 is operated by an operator to input cargo handling information necessary for the transfer operation of the transfer device 10 and to instruct the transfer device 10 to start the transfer operation. The input unit 15 is, for example, a control panel or a keyboard and mouse of a personal computer. The cargo handling information includes item-related information such as the product number, size, weight, and contents of the item W, as well as transfer operation-related information such as information on at least one of the loading position and the loading position. The first sensor 73 detects the internal air pressure (negative pressure) through the suction port 39b of the suction pad 39. Before the suction unit 32 suctions the item W, air flows in through the suction port 39b, so the negative pressure in the suction pad 39 does not exceed the threshold. When the suction unit 32 suctions the item W, the suction port 39b is blocked by the item W, preventing air from flowing in, causing the negative pressure in the suction pad 39 to exceed the threshold. The control unit 100 determines that the suction unit 32 has been able to suction the article W when the pressure detected by the first sensor 73 exceeds the threshold and becomes a negative pressure equal to or greater than a predetermined value.

[0077] The control unit 100 is also electrically connected to the robot 20, negative pressure generating unit 38, lifting cylinder 36, first cylinder 57, second cylinder 47, and opening / closing cylinder 62 as an output system. The control unit 100 controls the drive of the robot 20, negative pressure generating unit 38, lifting cylinder 36, first cylinder 57, second cylinder 47, and opening / closing cylinder 62 at predetermined timings according to a program.

[0078] When the control unit 100 detects that the suction unit 32 has adsorbed the article W based on the detection signal from the first sensor 73, it drives the lifting cylinder 36 to contract. As a result, the lifting mechanism 35 lifts the article W adsorbed by the suction unit 32.

[0079] When the second sensor 96 detects that the suction unit 32 has finished rising, the control unit 100 extends the opening / closing cylinder 62 to close the pair of receiving members 61. Next, when the control unit 100 detects that the pair of receiving members 61 has closed based on a detection signal from the third sensor 97, it extends the lifting / lowering cylinder 36 to lower the article W that has been sucked onto the suction unit 32.

[0080] Here, the descent process in which the suction part 32 descends from the raised position to place the article W on the upper surface of the pair of receiving members 61 is controlled by two stages of driving force. The suction position is set midway between the raised position and the lowered position. The suction position is set at a position that is a predetermined margin higher than the height at which the suction part 32 starts to come into contact with the article W when, for example, the article W is tilted at the maximum expected angle.

[0081] The first electromagnetic on-off valve 71 has a structure that allows the lift cylinder 36 to be in a free state (no pressure). Here, the free state refers to a state in which two chambers, defined by the piston in the lift cylinder 36, a piston-side chamber and a rod-side chamber, are connected to each other. The first electromagnetic on-off valve 71 has, for example, a restriction in the middle of the flow path connecting these two chambers. The first electromagnetic on-off valve 71 has a structure that allows it to be switched between a first switching position that drives the lift cylinder 36 to move up and down and a second switching position that allows the lift cylinder 36 to be in a free state. In this free state, the suction unit 32 descends together with the suction unit 32 due to the weight of the liftable member or the like. The first electromagnetic on-off valve 71 is switched to the first switching position during the process in which the suction unit 32 descends from the raised position to the suction position. The first electromagnetic on-off valve 71 is switched to the second switching position during the process in which the suction unit 32 moves from the suction position to suction the article W.

[0082] Therefore, the suction part 32 descends from the raised position to the suction position with the first driving force f1. Further, the suction part 32 descends with a second driving force f2 weaker than the first driving force f1 until it sucks the article W from the suction position. Also, let the descending speed of the suction part 32 due to the first driving force f1 be the first speed V1, and the descending speed of the suction part 32 due to the second driving force f2 be the second speed V2. The second speed V2 is smaller than the first speed V1 (V2 < V1). For this reason, when the suction part 32 at the raised position descends to the suction position, the suction part 32 descends at high speed with the first driving force f1 and the first speed V1. When the suction part 32 places the article W on the upper surfaces of the pair of receiving members 61 in the closed state, the suction part 32 descends slowly with the second driving force f2 and the second speed V2. Note that the control unit 100 may be constituted by a programmable logic controller (hereinafter also referred to as PLC) and a robot controller.

[0083] <Operation of the First Embodiment> Next, the operation of the transfer device 10 will be described with reference to FIGS. 10 to 17 and the like. Each process shown in FIGS. 10 to 17 shows a cycle of transfer work in which the suction mechanism 30 picks up the article W by suction at the picking position, then places the article W at the placing position, and starts the transfer work of the next article W to be transferred again. Hereinafter, as the transfer work, the step-by-step work of transferring the article W one by one from the uppermost stage of the article group on the pallet P to the conveyor 12 by the robot 20 will be described as an example. Note that the transfer work may be a stacking work.

[0084] An operator operates the input unit 15 to provide the necessary loading and unloading information and an instruction to start the transfer operation to the transfer device 10. When the control unit 100 receives the instruction from the input unit 15, it starts controlling the transfer device 10. The control unit 100 determines the route for transporting the item W from the unloading position to the loading position based on the loading and unloading information. The control unit 100 also acquires information such as the product number, shape, and size of the item W based on the loading and unloading information. The control unit 100 then starts the transfer operation of transferring the item W from the unloading position to the loading and unloading position. The transfer control performed by the control unit 100 will be described below with reference to each process in Figures 10 to 17. In detail, the transfer control is performed by the computer 110 in the control unit 100 executing a program. Note that some components such as the locking mechanism 46 and the slide mechanism 50 are omitted from Figures 10 to 17.

[0085] When the transfer device 10 is waiting for an instruction to perform the transfer operation, the lifting cylinder 36 of the lifting mechanism 35 is in a contracted state, and the opening / closing cylinder 62 of the receiving mechanism 60 is in a contracted state. In other words, the lifting mechanism 35 places the suction part 32 in a raised position, and the pair of receiving members 61 is in an open state. The first cylinder 57 and the second cylinder 47 are in an extended state. In other words, the suction part 32 is locked at the center position in the sliding direction X, and is locked in a horizontal position.

[0086] First, the control unit 100 moves the suction unit 32 toward the pickup start position, which is a predetermined height position above the pickup position. For example, when the transfer device 10 is in a standby state, the control unit 100 moves the suction unit 32 from the standby position to the pickup start position located directly above the item W to be transferred. This movement of the suction unit 32 to the pickup start position is performed by driving the robot arm 23. Here, the pickup start position in this example is a position where, for example, if the suction unit 32 is lowered from that position, the suction unit 32 can be positioned at a height position where it can pick up the item W to be picked up.

[0087] The control unit 100 puts the suction unit 32 into a state in which tilting and sliding are permitted. Specifically, the control unit 100 drives the first cylinder 57 from the extended state shown in Fig. 5 to the retracted state shown in Fig. 6, and drives the second cylinder 47 from the extended state shown in Fig. 7 to the retracted state shown in Fig. 8. As a result, the suction unit 32 is permitted to slide in the X direction as shown in Fig. 6, and is permitted to tilt about both the first axis 42 (X axis) and the second axis (Y axis) that intersect with each other as shown in Figs. 6 and 8.

[0088] The control unit 100 determines whether the robot 20 has reached the pickup start position. The control unit 100 analyzes the image of the group of articles captured by the camera 91 to determine the position coordinates of the article W to be transferred this time. The control unit 100 then determines whether the suction unit 32 has reached the pickup start position calculated from the position coordinates of the target article W. For example, when the suction unit 32 reaches the pickup start position shown in FIG. 10, the robot 20 stops the movement of the suction mechanism 30.

[0089] The control unit 100 lowers the suction unit 32. That is, the control unit 100 lowers the suction unit 32 by extending the lifting cylinder 36. During this lowering process, the control unit 100 generates negative pressure in the suction port 39b of the suction unit 32 by driving the negative pressure generating unit 38. The suction unit 32, which has been lowered from the pickup start position shown in FIG. 10, comes into contact with the item W as shown in FIG. 11. The suction unit 32 reaches the surface to be suctioned of the item W. Note that even if the suction unit 32 reaches the surface to be suctioned of the item W, the suction port 39b of the suction unit 32 may not be blocked by the surface to be suctioned, and the item W may not be suctioned.

[0090] For example, if an article W is tilted and overlaps an adjacent article W, the suction part 32 tilts around the tilting fulcrum as it descends, but there is still a gap between it and the tilted article W, making it unable to adsorb the article W. As the suction part 32 descends further, the tilting fulcrum of the suction part 32 slides toward the less tilted side of the tilted article W, causing the suction part 32 to tilt around the tilting fulcrum. The suction part 32 comes into contact with the entire surface of the tilted article W to be adsorbed.

[0091] 12, the control unit 100 determines whether or not suction has been detected. The control unit 100 determines whether or not suction has been detected based on the detected pressure (detected negative pressure) of the first sensor 73 exceeding a threshold value. The control unit 100 waits until suction is detected. When the suction port 39b of the suction unit 32 abuts its entire surface against the surface to be suctioned of the article W, the article W is suctioned to the suction unit 32, and the negative pressure inside the suction unit 32 exceeds the threshold value, so suction is detected.

[0092] Next, as shown in FIG. 13, when suction is detected, the control unit 100 raises the suction unit 32 to the article-receiving end position. The article W adsorbed to the suction unit 32 is lifted up. As shown in FIG. 13, when the article W is lifted up, the tilting fulcrum of the suction unit 32 may be shifted from the center position of the sliding range. In this example, the article-receiving end position is the position when the suction unit 32 reaches the raised position. In this embodiment, the process in which the suction unit 32 adsorbs and lifts the article W when the pair of receiving members 61 are in the open state corresponds to an example of the suction process.

[0093] Next, the control unit 100 returns the suction unit 32 to the center position in the sliding direction. The pair of first cylinders 57 are extended, thereby returning the tilting fulcrum of the suction unit 32 to the center position in the X direction (see FIG. 5). As a result, the tilting fulcrum of the suction unit 32 is locked at the center position. The control unit 100 also extends the pair of second cylinders 47, thereby locking the suction unit 32 in a horizontal position.

[0094] 14, the control unit 100 closes the pair of receiving mechanisms 60 from the open state to the closed state. As the opening / closing cylinder 62 is driven to extend, the pair of receiving mechanisms 60 close from the open state to the closed state.

[0095] Next, as shown in FIG. 15 , the control unit 100 lowers the suction unit 32. The lifting cylinder 36 is extended, causing the suction unit 32 to lower from the raised position. During the process of the suction unit 32 lowering from the raised position to the suction position, the control unit 100 switches the first electromagnetic on-off valve 71 to the first switching position. As a result, the suction unit 32 lowers from the raised position to the suction position with a first driving force f1. Furthermore, during the process of the suction unit 32 adsorbing the article W from the suction position, the control unit 100 switches the first electromagnetic on-off valve 71 to the second switching position, causing the lifting cylinder 36 to be in a free state (no pressure). As a result, the suction unit 32 lowers with a second driving force f2, which is weaker than the first driving force f1, from the suction position until it adsorbs the article W. Furthermore, while the suction unit 32 is descending, the first sensor 73 detects the pressure inside the lifting cylinder 36, and suction is detected when the detected pressure (detected negative pressure) exceeds a second threshold. Here, exceeding the second threshold may also mean falling below the second threshold. In short, it is sufficient to detect that the article W has been placed on the pair of receiving members 61. In this way, by lowering the suction unit 32 with the lifting cylinder 36 in a free state, the article W is placed so as to be lightly pressed against the receiving members 61 in the closed state by the second driving force f2.

[0096] At this time, the suction portion 32 is locked in a horizontal position, so the article W is placed in a substantially horizontal position on the upper surfaces of the pair of receiving members 61. For example, if the suction portion 32 is tiltable, the article W may be placed in an oblique position on the upper surfaces of the pair of receiving members 61 if it shakes. However, in this embodiment, the article W can be placed in a horizontal position on the upper surfaces of the pair of receiving members 61 without shaking.

[0097] Next, as shown in Fig. 16, the control unit 100 raises the suction unit 32. The lifting cylinder 36 is driven to contract, causing the suction unit 32 to rise from the lowered position to the raised position. At this time, the first electromagnetic on-off valve 71 is returned from the second switching position to the first switching position, causing the suction unit 32 to rise at a relatively high speed. In this embodiment, after the receiving mechanism 60 closes the pair of receiving members 61 to the closed state, the suction unit 32 and the receiving members 61 move relatively toward each other in the vertical direction Z, causing the pair of receiving members 61 in the closed state to receive the article W, which corresponds to an example of a receiving process.

[0098] Next, the control unit 100 moves the suction mechanism 30 toward the placement start position (transfer destination). This movement of the suction mechanism 30 is performed by driving the robot arm 23 of the robot 20. During this movement, the tilting fulcrum of the suction part 32 is locked at the center position, and the suction part 32 is locked in a horizontal position. This suppresses rattles in the sliding direction of the suction part 32 and shaking of the suction part 32 around the tilting fulcrum while the article W is moving.

[0099] Then, by driving the robot arm 23, the suction mechanism 30 reaches the loading position above the conveyor 12 and stops in the state shown in Fig. 16. Note that in this embodiment, the process in which the robot 20 moves the suction mechanism 30 while the pair of receiving members 61 in the closed state have received the article W corresponds to an example of a transfer process.

[0100] Next, as shown in FIG. 17 , the control unit 100 extends the opening / closing cylinder 62 to open the pair of receiving members 61 from the closed state to the open state. At this time, the opening / closing cylinder 62 is extended at a slow speed, so that the pair of receiving members 61 open slowly from the closed state to the open state. As a result, the article W gradually descends along the slopes of the pair of receiving sections 70 and is placed on the conveyor 12. Once the pair of receiving members 61 open to an opening angle that ensures that the article W has been placed on the conveyor 12, the opening speed of the pair of receiving members 61 may be switched to a high speed. In this case, the opening speed of the pair of receiving members 61 may be increased stepwise or continuously. When the article W is placed on the conveyor 12, the control unit 100 drives the robot arm 23 of the robot 20 to move the suction mechanism 30 to the pickup start position where the next article W to be transferred is located.

[0101] In this embodiment, the suction unit 32 is driven at a low speed during the process of suctioning the article W and during the process of placing the article W on the upper surface of the pair of receiving members 61, but is driven at a high speed during the process of rising after placing the article W. This contributes to shortening the cycle time of the transfer operation.

[0102] <Effects of the first embodiment> As described above in detail, according to this embodiment, the following effects can be obtained. (1-1) An article transfer device 10 that adsorbs and transfers an article W includes a suction mechanism 30 having an adsorption unit 32 capable of adsorbing the article W, a robot 20 that moves the suction mechanism 30 in a movement direction including the lifting direction, and a receiving mechanism 60. The receiving mechanism 60 has a pair of receiving members 61 that can be opened and closed via a scissors mechanism between an open state in which the adsorption unit 32 opens to a position that does not interfere with the adsorption operation of adsorbing the article W, and a closed state in which the adsorption unit 32 adsorbs and lifts the article W from below. The suction unit 32 adsorbs the article W when the pair of receiving members 61 are in the open state. The robot 20 moves the suction mechanism 30 with the pair of receiving members 61 in the closed state receiving the article W. Note that the closed state does not necessarily mean that the pair of receiving members 61 are closed to a position where they come into contact with each other; the pair of receiving members 61 may be spaced apart and moved relative to each other in the closing direction compared to the open state. In other words, as long as the pair of receiving members 61 can receive the item W, they may be spaced apart or in contact with each other in the closed state, provided that the opening angle is small enough to receive the item W compared to the open state. With this configuration, the suction unit 32 picks up the item W when the pair of receiving members 61 are open, and the robot 20 moves the suction mechanism 30 with the pair of receiving members 61 in the closed state receiving the item W. Because the receiving mechanism 60 has a pair of receiving members 61 configured to be openable and closable via a scissors mechanism, the item W picked up by the suction unit 32 can be transported while being firmly supported from below by the pair of receiving members 61. For example, the item W can be transported while separated from the suction unit 32 and received by the receiving members 61. This configuration can suppress deterioration of the suction unit 32 compared to a configuration in which the item W is transported while still attached to the suction unit 32 by the suction force used when picking up the item. Furthermore, damage and suction marks on the item W due to the suction force of the suction unit 32 can be reduced during transport.

[0103] Furthermore, with a conventional rotating receiving member having multiple plates, the article W may tilt when placed at the destination. However, with the receiving mechanism 60 in which a pair of receiving members 61 open and close, the article W is less likely to tilt when placed at the destination. Furthermore, with a conventional rotating receiving member, when the article W is removed from the suction portion 32 and placed on the plate for transportation, there is a significant possibility that the article W may slip on the plate, tilt, or fall. Therefore, the article W must be transported while being held by the suction portion 32 and sandwiched between the suction portion 32 and the plate. This makes the suction portion 32 prone to deterioration. Deterioration of the suction portion 32 makes it difficult to suction the article W due to air leaks, etc. This increases the frequency of replacement of the suction portion 32. This leads to inconveniences such as increased component costs for the suction portion 32 and reduced production efficiency due to replacement of the suction portion 32. In contrast, the suction mechanism 30 of this embodiment can eliminate these inconveniences.

[0104] (1-2) The receiving mechanism 60 includes an opening / closing cylinder 62 as an example of a drive unit that opens and closes the pair of receiving members 61. According to this configuration, the pair of receiving members 61 can be opened and closed at the required timing by the opening / closing cylinder 62. For example, the pair of receiving members 61 can be opened while the suction unit 32 is suctioning the article W, and can be closed after the article W has been suctioned and lifted up.

[0105] (1-3) The receiving mechanism 60 closes the pair of receiving members 61 after the suction portion 32 lifts up the article W. According to this configuration, the pair of receiving members 61 closes after the suction portion 32 lifts up the article W, so that the closed pair of receiving members 61 can receive the article W.

[0106] (1-4) After closing the pair of receiving members 61, the receiving mechanism 60 places the article W on the pair of receiving members 61 by relatively moving the suction parts 32 and the receiving members 61 in a direction toward each other in the vertical direction Z, and then relatively moving the suction parts 32 and the receiving members 61, which have released their suction, in a direction away from each other in the vertical direction Z. The robot 20 moves the suction mechanism 30 in a state where the suction of the suction parts 32 is released and the pair of receiving members 61 receives the article W from below. With this configuration, the article W can be transported in a state where the suction of the suction parts 32 is released and the article W is received by the receiving members 61, thereby suppressing deterioration such as wear of the suction parts 32. This reduces suction failures due to air leaks from the suction parts 32 and the frequency of replacement due to deterioration of the suction parts 32.

[0107] (1-5) The suction mechanism 30 includes a tilting mechanism 40 that tiltably supports the suction portion 32, and a locking mechanism 46 that can switch the tilting mechanism 40 between an unlocked state that allows the suction portion 32 to tilt and a locked state that locks the suction portion 32 in a horizontal position. After closing the pair of receiving members 61, with the suction portion 32 locked in a horizontal position, the suction portion 32 and the pair of receiving members 61 move relatively toward each other in the vertical direction Z, thereby placing the item W on the pair of receiving members 61 in the closed position. With this configuration, the tilting mechanism 40 is locked, allowing the item W to be placed on the pair of receiving members 61 while maintaining a horizontal position. For example, compared to a configuration in which the tilting mechanism 40 is unlocked and the item W is placed on the pair of receiving members 61 in an inclined position inclined from the horizontal, misalignment of the item W at the transfer destination is less likely to occur in the placement position or placement position of the item W. In other words, the item W can be placed in an appropriate position with an appropriate posture and minimal misalignment.

[0108] (1-6) During the suction operation to suction the item W, the suction unit 32 is lowered from the raised position to the suction position with a first driving force f1. When the suction unit 32 at the suction position descends until it has adsorbed the item W, the suction unit 32 is lowered with a second driving force f2 that is weaker than the first driving force f1. When the item W that the suction unit 32 has adsorbed and pulled up is placed on the pair of receiving members 61 in the closed state, the suction unit 32 is lowered with the second driving force f2. According to this configuration, before adsorbing the item W, the suction unit 32 descends to the suction position at high speed with the first driving force f1, and when the suction unit 32 at the lowered position adsorbs the item W, the suction unit 32 contacts the item W with a weak pressure. Furthermore, when placing the item W on the receiving member 61, the suction portion 32 descends with a second driving force f2 that is smaller than the first driving force f1, so that when placing the item W on the receiving member 61, the pressing force with which the suction portion 32 presses the item W can be small.

[0109] (1-7) The suction mechanism 30 attached to the arm 23 of the robot 20 includes a suction unit 32 capable of suctioning an item W, and a receiving mechanism 60. The receiving mechanism 60 has a pair of receiving members 61 configured to be openable and closable via a scissors mechanism between an open state in which the suction unit 32 opens to a position that does not interfere with the suction operation of suctioning the item W, and a closed state in which the suction unit 32 receives the item W from below after suctioning and lifting it up. The suction unit 32 suctions the item W when the pair of receiving members 61 are in the open state. During the process in which the robot 20 transfers the item W, the pair of receiving members 61 are set to a closed state in which they receive the item W from below. With this configuration, the item W can be transferred while being firmly supported from below.

[0110] (1-8) The article transfer method for adsorbing and transferring the article W includes an adsorption step, a receiving step, and a transporting step. In the adsorption step, the adsorption unit 32 adsorbs and lifts the article W when the pair of receiving members 61 are in the open state. In the receiving step, the receiving mechanism 60 closes the pair of receiving members 61 to the closed state, and then the adsorption unit 32 and the receiving members 61 move relatively in the vertical direction Z toward each other, so that the pair of receiving members 61 in the closed state receive the article W. In the transporting step, the robot 20 moves the adsorption mechanism 30 in a state where the pair of receiving members 61 in the closed state receive the article W. According to this article transfer method, the article W can be transported while being firmly supported from below.

[0111] (Second embodiment) Next, a second embodiment will be described with reference to Figures 18 to 33. The transfer device 10 of the second embodiment differs from the first embodiment in that the suction method of the suction unit 32 is a method that uses a blower 28 (see Figure 25) as a negative pressure supply source, and the configuration of the receiving unit 70 has been changed to a receiving unit 80 (see Figures 18 to 22). The basic configuration of the suction mechanism 30 is the same as that of the first embodiment. Therefore, in the following, the same reference numerals will be used to designate components and the like that are common to the first embodiment, and a description thereof will be omitted, and the following description will focus on components that are different from the first embodiment.

[0112] As shown in FIGS. 18 to 21, the transfer device 10 includes a robot 20 (see also FIG. 1) as an example of a moving mechanism that moves a suction mechanism 30 that suctions an item W, and the suction mechanism 30 attached to the tip of a robot arm 23. The suction mechanism 30 is detachably attached to the tip of the robot arm 23. The suction mechanism 30 has a suction unit 32 that can suction the item W. The suction unit 32 is capable of suctioning and releasing the suction of the item W. In this embodiment, the suction method of the suction unit 32 differs from that of the first embodiment, and the item W is suctioned by utilizing a suction airflow that flows into the suction unit 32. In FIGS. 18 to 21, the item W that has been suctioned by the suction unit 32 and is separated from the conveyor 12 is indicated as item W1, and the item W placed on the conveyor 12 is indicated as item W2.

[0113] The suction mechanism 30 is connected to a blower 28 (see FIG. 25), which is a negative pressure source of the air pressure circuit, through a hose 75. The blower 28 is disposed, for example, on the installation stand 13 or at a position adjacent to the installation stand 13 in FIG.

[0114] One end of hose 75 is connected to blower 28 via a duct (not shown). Hose 75 extending from blower 28 is piped along robot arm 23 and extends to suction mechanism 30 via a path that does not interfere with the movement of robot arm 23. Suction mechanism 30 includes a coupling member 76 to which one end of hose 75 and its upper end are connected. The lower end of coupling member 76 is connected to first piping member 77 provided in suction mechanism 30 via first hose 75A. Two second hoses 75B extending from first piping member 77 are each connected to suction section 32 via a predetermined curved path.

[0115] The suction unit 32 includes a suction pad 39 and a second piping member 78. The other ends of the two second hoses 75B are connected to the second piping member 78. One hose 75 is branched into two via the first piping member 77, and the two second hoses 75B are connected to the suction unit 32, respectively, thereby ensuring a flow rate sufficient to generate a suction airflow of the strength required for the suction unit 32.

[0116] A control unit 100 (see FIG. 1) of the robot 20 controls an electromagnetic on-off valve 85 (see FIG. 25) connected midway through the hose 75, thereby controlling the suction and release of the article W at the suction unit 32. As shown in FIG. 18, the suction mechanism 30 is provided with a flexible cable 79 including tubes, cables, etc. that transmit air pressure, power, and control signals to a lifting section including the suction unit 32 that is lifted and lowered by the lifting mechanism 35.

[0117] In the first embodiment, the suction section 32 employs a suction method in which it suctions the article W using negative pressure generated by an ejector constituting the negative pressure generating unit 38. Therefore, if there is an air leak between the suction section 32 and the article W, the negative pressure decreases, and the suction force is likely to decrease. In contrast, in the present embodiment, the suction section 32 employs a suction method in which it suctions the article W using a suction airflow generated by the blower 28 as a negative pressure source. That is, the suction section 32 suctions the article W using a suction airflow that flows into the suction pad 39 due to the suction force of the blower 28. Therefore, even if there is some air leak between the suction section 32 and the article W, the suction section 32 can maintain its suction force to suction the article W. Details of the pneumatic circuit that uses the blower 28 as a negative pressure source will be described later.

[0118] As in the first embodiment, the suction mechanism 30 includes a lifting mechanism 35 that lifts and lowers the suction portion 32, a tilting mechanism 40 that tilts the suction portion 32, a sliding mechanism 50 that slides the suction portion 32, and a return mechanism 55 that returns the tilt and sliding displacement of the suction portion 32. Also, as in the first embodiment, the suction mechanism 30 of this embodiment includes a receiving mechanism 60, but the configuration of a receiving member 61 that is the part of the receiving mechanism 60 that receives the article W is different from that of the first embodiment.

[0119] The lifting mechanism 35, tilting mechanism 40, slide mechanism 50, and return mechanism 55 will be briefly described below with reference to FIGS. 19 to 22. These configurations are basically the same as those of the first embodiment, and will only be briefly described. The suction mechanism 30 includes a mechanism main body 31 including a skeleton frame and the like. The lifting mechanism 35 supports the suction part 32 so that it can be raised and lowered relative to a support part 34 that constitutes the mechanism main body 31. The lifting mechanism 35 includes one vertical lifting cylinder 36. The lifting cylinder 36 is disposed downward with the rod side facing downward, and the lower end of its piston rod 36a is fixed to a lifting member 37. When the lifting cylinder 36 is driven to extend and retract, the suction part 32, which is supported in a suspended state by the lifting member 37, rises and falls.

[0120] The tilting mechanism 40 shown in Fig. 20 is provided between the lifting member 37 and the suction part 32, and supports the suction part 32 so that it can tilt. The tilting mechanism 40 includes a joint mechanism 41 that supports the suction part 32 so that it can tilt. The joint mechanism 41 is configured, for example, by a cross joint. The joint mechanism 41 has a first shaft 42 (X-axis), a second shaft 43 (Y-axis), and a connecting member 44 that holds both shafts 42, 43. The connecting member 44 has a block 45 that protrudes upward.

[0121] The suction part 32 has a swinging member 48 that is connected to the joint mechanism 41 in a state where it can rotate around the second axis 43. The suction part 32 is supported in a state where it can tilt around two axes, X and Y, via the swinging member 48 and the joint mechanism 41. That is, the suction part 32 can tilt around the X axis, centered on the first axis 42, and around the Y axis, centered on the second axis 43.

[0122] The slide mechanism 50 is provided between the lifting member 37 and the suction unit 32, and supports the suction unit 32 so that it can slide in the horizontal direction. The connecting member 44 is supported so that it can slide in the X direction along the first shaft 42. In other words, the connecting member 44 functions as a slider that can move in the X direction along the first shaft 42. This forms the slide mechanism 50 that slides the suction unit 32 in the X direction. The slide mechanism 50 includes a pair of regulating members 51 that regulate the range in which the connecting member 44 slides along the first shaft 42. The pair of regulating members 51 are fixed to both ends of the first shaft 42.

[0123] Therefore, the suction part 32 is supported in a state in which it can tilt about two axes, X and Y, relative to the lifting member 37 and can slide in the X direction within a predetermined range. In this way, the suction part 32 can be raised and lowered relative to the support part 34 by the lifting mechanism 35, can be tilted relative to the lifting member 37 by the tilting mechanism 40 via the joint mechanism 41, and the tilting fulcrum can be slid in the X direction by the slide mechanism 50.

[0124] The suction portion 32 includes a suction pad 39. The suction pad 39 has the same configuration as in the first embodiment, and has a ring-shaped pad portion 39a at its lower end. A suction port 39b surrounded by the pad portion 39a is opened on the lower surface of the suction pad 39.

[0125] The suction mechanism 30 also includes a return mechanism 55 similar to that of the first embodiment. The return mechanism 55 includes a lock mechanism 46 and a center return mechanism 56 between the lifting member 37 and the suction part 32. The lock mechanism 46 is switchable between an unlocked state, which allows the suction part 32 to be tilted by the tilting mechanism 40, and a locked state, which locks the suction part 32 in a horizontal position. The lock mechanism 46 has a tilt return function that returns the suction part 32, which has been tilted by the tilting mechanism 40, from the tilted position to the horizontal position.

[0126] The center return mechanism 56 switches between a locked state in which the suction part 32 is locked at the center position so that it cannot slide, and an unlocked state in which the suction part 32 is allowed to slide in the slide direction X. The center return mechanism 56 has a slide return function that returns the suction part 32 slid by the slide mechanism 50 to the center position in the slide direction X, and a lock function that locks the suction part 32 at the center position so that it cannot slide. In this embodiment, the suction part 32 returned by the return mechanism 55 is locked at the center position in the slide direction X and is locked in a horizontal position.

[0127] <Detailed configuration of the center return mechanism 56> As shown in FIG. 20 , the center return mechanism 56 includes a block 45 at the upper end of the connecting member 44, which functions as a slider, and a pair of first cylinders 57 positioned opposite each other on either side of the block 45 in the X direction. The center return mechanism 56 is driven between a locked position (shown in FIG. 5 ) that does not allow the suction unit 32 to slide, and a slide-permitted position (shown in FIG. 6 ) that allows the suction unit 32 to slide using the slide mechanism 50. When the pair of first cylinders 57 is extended, the tips of the pair of rods 57a sandwich the block 45 from both sides in the X direction, locking the tilt fulcrum of the suction unit 32 in the center position so that it cannot slide. When the first cylinders 57 are retracted, the pair of rods 57a are retracted in directions away from each other, allowing the block 45 to slide freely in the X direction. In other words, the tilt fulcrum of the suction unit 32 is allowed to slide freely in the X direction.

[0128] At this time, if tilting of the suction part 32 is permitted, when the suction part 32 adsorbs the article W, it tilts in a direction corresponding to the inclination of the adsorbed surface of the article W. Therefore, depending on the inclination of the article W, the suction part 32 tilts from a horizontal position in the counterclockwise direction indicated by the solid line in FIG. 6 or in the clockwise direction indicated by the two-dot chain line in the same figure. Therefore, even if the article W is tilted, the suction part 32 can reliably adsorb the article W by pressing the entire surface of the suction pad 39 against the adsorbed surface of the article W. Furthermore, the tilting fulcrum of the suction part 32 slides in the X direction during the tilting process, thereby ensuring a large tilting angle.

[0129] <Detailed configuration of lock mechanism 46> 22, the locking mechanism 46 includes a restricting plate 49 fixed to the upper end of the suction part 32, and a pair of second cylinders 47 arranged facing downward and facing the restricting plate 49. When the second cylinders 47 are extended, pressing parts 47a fixed to the tip of each rod simultaneously press both ends of the restricting plate 49 from above, thereby holding the restricting plate 49 in a horizontal position. Thus, the suction part 32 is held in a horizontal position in a locked state where it cannot tilt. During the process in which the robot 20 transfers the article W, the suction part 32 is locked in the horizontal position.

[0130] Furthermore, when the second cylinder 47 is driven to contract, the pressing portion 47a moves away from the upper surface of the regulating plate 49, allowing the suction portion 32 to tilt. Therefore, when the suction portion 32 comes into contact with a tilted article W, it tilts from the horizontal position in accordance with the tilt of the article W. This allows the entire suction opening 39b of the suction pad 39 to be pressed against the surface to be suctioned of the tilted article W, thereby suctioning the article W.

[0131] <Configuration of receiving mechanism 60> 18 to 21, the suction mechanism 30 includes a receiving mechanism 60 that receives from below the article W picked up by the suction portion 32. The receiving mechanism 60 has the same basic configuration as that of the first embodiment, but the configuration of the pair of receiving portions 80 of the pair of receiving members 61 is different from the receiving portions 70 of the first embodiment.

[0132] The receiving mechanism 60 has a pair of receiving members 61 (only one of the receiving members 61, the front one, is shown in FIG. 18 ) that receive the article W. As in the first embodiment, the receiving mechanism 60 includes a pair of opening / closing cylinders 62 as an example of a drive unit that opens and closes the pair of receiving members 61, and a pair of link mechanisms 63 that convert the extension and contraction drive of the pair of opening / closing cylinders 62 into an opening and closing movement of the pair of receiving members 61. The link mechanism 63 is, for example, a scissors mechanism. The pair of receiving members 61 are configured to be openable and closable via the link mechanism 63, which is also a scissors mechanism. Note that the link mechanism 63 may also be a pantograph mechanism including a scissors mechanism. When the link mechanism 63 is a scissors mechanism or a pantograph mechanism, a force in the closing direction acts on the pair of receiving members 61 due to the weight of the article W that the pair of receiving members 61 are receiving from below.

[0133] The link mechanism 63 includes a pair of first link members 65 and a pair of second link members 66. One end of each of the pair of first link members 65 is a rotatable fixed end, and the other end of each is rotatably connected to one end of each of the pair of second link members 66 via a connecting shaft 68. The pair of second link members 66 are rotatably connected at their intersection. The second link members 66 form the base of a receiving member 61 that has a substantially L-shape in side view as shown in FIG. 19. That is, the receiving member 61 has the second link member 66 and a receiving portion 80 fixed to the other end (tip portion) of the second link member 66. The detailed configuration of the receiving portion 80 will be described later.

[0134] The second link member 66 and the receiving portion 80 form a predetermined angle (approximately a right angle in the examples of Figures 19 and 21). The pair of receiving portions 80 open and close as the pair of receiving members 61 open and close. When the pair of receiving members 61 are in the open state shown in Figure 19, the pair of receiving portions 80 are spaced apart by a distance (hereinafter referred to as the "first distance") that ensures a path for the suction portion 32 to reach the article W. When the pair of receiving members 61 are in the closed state shown in Figure 21, the pair of receiving portions 80 approach a distance (hereinafter referred to as the "second distance") that allows them to receive an article W that has been adsorbed by the suction portion 32 or an article W that has been released from adsorption by the suction portion 32.

[0135] As shown in Fig. 19, the first interval is wider than the dimension of the short side of the article W. As shown in Fig. 21, the second interval is narrower than the dimension of the short side of the article W. When there are multiple sizes of the article W, the first interval is wider than the dimension of the short side of a large-sized article W. The second interval is narrower than the dimension of the short side of a small-sized article W.

[0136] As shown in Figures 18 and 20, the suction mechanism 30 of this embodiment picks up or places an article W on a conveyor 12. The conveyor 12 is a roller conveyor in which a plurality of rollers 16 are arranged at regular intervals in a first direction (X direction). For this reason, hereinafter, the conveyor 12 will also be referred to as a roller conveyor 12. The receiving portion 80 has a plurality of hook members 81 arranged at intervals in the first direction (X direction). The hook members 81 are shaped like long rods or long plates, and are shaped so as to bend inward at an obtuse angle midway along their longitudinal direction.

[0137] <Configuration of receiving portion 80> Next, the configuration of the receiving portion 80 will be described with reference to FIG. 23 . The receiving portion 80 includes a plurality of hook members 81. The hook members 81 are arranged at regular intervals in a first direction (X direction), which is the rotation axis direction of the link mechanism 63. The hook members 81 are attached to a cross member 83, which is a long plate member connected and spanning the tip ends of a pair of second link members 66 in the X direction. The cross member 83 has a plurality of screw holes 84 formed at intervals in the X direction, which is its longitudinal direction. The hook member 81 has an attachment portion 81A at its base end. The attachment portion 81A has two screw holes (not shown) formed therein, which correspond to one set of screw holes 84 out of a plurality of sets (two each) of screw holes 84 formed in the cross member 83 at regular intervals. The hook member 81 is fixed to the cross member 83 by threading a bolt B inserted through the screw hole of the attachment portion 81A into one set of screw holes 84.

[0138] As shown in FIG. 23, the pitch HP of the multiple hook members 81 is equal to the pitch RP of the rollers 16. The pitch RP of the rollers 16 may differ depending on the roller conveyor 12 to which the article W is to be transferred. For this reason, the receiving unit 80 is provided with a spacing change mechanism 82 configured to change the spacing of the multiple hook members 81 in the first direction (X direction). The spacing change mechanism 82 is provided with the above-mentioned mounting portions 81A and multiple sets of screw holes 84 that are provided so that the pitch HP of the multiple hook members 81 can be matched to the expected pitch RP of the rollers 16. By selecting, from the multiple sets of screw holes 84 aligned in the first direction (X direction), the screw hole 84 to be screwed into when fixing the mounting portion 81A of the hook member 81 with the bolt B, it is possible to match the pitch HP of the hook members 81 to the pitch RP of the rollers 16. By adjusting the pitch HP of the multiple hook members 81 using the spacing change mechanism 82, the user can arrange the multiple hook members 81 at a spacing that allows them to be inserted into the gap G between the rollers 16, as shown in Figure 23.

[0139] Furthermore, the receiving portion 80 having a plurality of hook members 81 can more reliably receive an item W made of a smaller bag body than the receiving portion 70 having a plurality of round pipes 70a arranged horizontally so as to extend in the X direction in the first embodiment.

[0140] As shown in FIG. 20 , even when the pair of receiving members 61 is in a closed state, the multiple hook members 81 constituting the pair of receiving sections 80 can be inserted through the gap between the rollers 16 below the top surfaces of the rollers 16 without interfering with the rollers 16 of the roller conveyor 12. Therefore, the suction section 32 can close the pair of receiving sections 80 after adsorbing the article W placed on the rollers 16 and before lifting it up. The pair of receiving sections 80 can receive the article W from below while it is still positioned on the rollers 16 using the multiple hook members 81. The article W adsorbed by the suction section 32 can then be lifted up after being received by the pair of receiving sections 80 from below. Therefore, even if the article W becomes detached from the suction section 32 due to an air leak or the like while the suction section 32 is lifting up the article W, the article W will not fall because the pair of receiving sections 80 is receiving the article W from below. Even if the article W falls, it will only fall a few centimeters before being received by the pair of receiving sections 80, and the impact of the fall will be quite small.

[0141] Furthermore, when placing an article W on the roller conveyor 12, the article W can be placed on the roller conveyor 12 while the pair of receiving parts 80 in the closed state are receiving the article W from below. That is, by inserting the multiple hook members 81 constituting the receiving parts 80 into the gaps between the rollers 16, the article W can be placed on the rollers 16 while being received from below by the pair of receiving parts 80 in the closed state. Therefore, even if the article W becomes detached from the suction parts 32 due to an air leak or the like during the placing process, the article W will not fall, or even if it does fall, it will only fall a few centimeters before being received by the pair of receiving parts 80.

[0142] <Configuration of pneumatic circuit> Next, with reference to Fig. 24, the pneumatic circuit that applies suction force from a negative pressure source to the suction unit 32 will be described. As shown in Fig. 24, the pneumatic circuit includes a vacuum pump 29 that is the drive source for a blower 28 that is the negative pressure source. The vacuum pump 29 exhausts air using a fan, thereby generating a suction airflow in the piping upstream of the vacuum pump 29. The suction unit 32 is configured to be able to suction the article W with the suction airflow generated by the blower 28 as the negative pressure source.

[0143] The vacuum pump 29 is connected to the suction unit 32 via a pipe including hoses 75 (75A, 75B) and the like. A solenoid valve 85 and a filter 89 are provided in series in the pipe between the vacuum pump 29 and the suction unit 32. The solenoid valve 85 is controlled by the control unit 100 (FIG. 1). When the solenoid valve 85 is in the open position shown in FIG. 24 while the vacuum pump 29 is operating, a suction airflow is generated in the suction unit 32, flowing into the suction port 39b of the suction pad 39. When the solenoid valve 85 is in the closed position, no suction airflow is generated in the piping located upstream of the solenoid valve 85 in the flow direction of the suction airflow. Therefore, when the solenoid valve 85 is in the closed position, the suction force of the suction unit 32 is lost. Alternatively, the solenoid valve 85 may be configured to be switched by an electromagnetic force and an auxiliary force generated by a pilot pressure, as shown in FIG. 24.

[0144] The piping branches between the electromagnetic on-off valve 85 and the suction unit 32. A flow rate adjustment valve 86, which is an example of a flow rate adjustment unit, is provided on the branched piping. The flow rate adjustment valve 86 is equipped with a motor 86M as a power source. The opening degree of the flow rate adjustment valve 86 is adjusted by controlling the rotation position of the motor 86M with the control unit 100 (FIG. 1). The flow rate adjustment valve 86 adjusts the flow rate of the suction airflow flowing through the piping connecting the electromagnetic on-off valve 85 and the suction unit 32 by increasing or decreasing the leak flow rate of air passing through the flow rate adjustment valve 86 by adjusting the opening degree. In other words, the flow rate adjustment valve 86 is configured to be able to adjust the suction force acting on the article W sucked by the suction unit 32 by increasing or decreasing the leak flow rate of air passing through the flow rate adjustment valve 86.

[0145] When the vacuum pump 29 is operating and the electromagnetic on-off valve 85 is in the open position, the flow rate of the suction airflow flowing into the suction port 39b of the suction unit 32 is adjusted according to the aperture of the flow rate adjustment valve 86. Specifically, the vacuum pump 29 of the blower 28 is driven at a predetermined rotational speed, and the resulting suction force generates a suction airflow toward the blower 28 through the piping consisting of the hoses 75, 75A, and 75B. If the suction airflow has only one air intake port, the suction port 39b of the suction unit 32, a large suction force is generated at the suction unit 32. Air leakage occurs, in which air at a flow rate corresponding to the aperture of the flow rate adjustment valve 86 is also drawn into the piping via the flow rate adjustment valve 86, reducing the suction force of the suction unit 32. In this way, the control unit 100 adjusts the aperture of the flow rate adjustment valve 86 to adjust the suction force of the suction unit 32.

[0146] The suction unit 32 is provided with a pressure switch 98 as an example of a detection unit. The pressure switch 98 is configured to detect excessive negative pressure, which occurs when the negative pressure within the suction unit 32 exceeds a negative pressure threshold. The pressure switch 98 switches from off to on when the negative pressure within the suction unit 32 exceeds the negative pressure threshold. The negative pressure threshold of the pressure switch 98 is set to a value that is weaker by a predetermined margin than the excessive negative pressure that may cause the bag, which is the article W, to rupture, depending on the strength of the bag. When the pressure switch 98 is on, the control unit 100 adjusts the opening of the flow rate control valve 86 to a larger value. By increasing the opening of the flow rate control valve 86 and increasing the leakage flow rate, the negative pressure acting on the article W suctioned to the suction unit 32 is adjusted to a smaller value. Note that when the pressure switch 98 is on, the control unit 100 may stop suction by the suction unit 32 by switching the electromagnetic on-off valve 85 from an open position to a closed position. Silencers 87 and 88 (silencers) having a noise reduction function are provided on the exhaust port side of the vacuum pump 29 and the air intake port side of the flow rate adjustment valve 86, respectively.

[0147] <Electrical configuration of the transfer device 10 in the second embodiment> Next, the electrical configuration of the transfer device 10 will be described with reference to Fig. 25. The electrical configuration of the transfer device 10 differs from that of the first embodiment in that it is a suction type that uses the blower 28 shown in the pneumatic circuit of Fig. 24 as a negative pressure source.

[0148] As shown in FIG. 25, the control unit 100 of the transfer device 10 controls the transfer device 10 by executing a program read by the computer 110 from the memory 120. The control unit 100 is electrically connected to an input system including the input unit 15, the camera 91, the first sensor 73, the second sensor 96, the third sensor 97, and the pressure switch 98. The first sensor 73 detects that the suction unit 32 has adsorbed the article W. The second sensor 96 detects the elevation state of the suction unit 32. The third sensor 97 detects the open / closed state of the pair of receiving members 61 that constitute the receiving mechanism 60, i.e., the open / closed state of the pair of receiving units 80. The pressure switch 98 and the first sensor 73 may be configured as a single pressure sensor that performs both functions.

[0149] The pressure switch 98 is turned on and off by the air pressure (negative pressure) within the suction port 39b of the suction pad 39. Before the suction unit 32 suctions the item W, suction airflow flows in through the suction port 39b, so the negative pressure within the suction pad 39 does not exceed a threshold. When the suction unit 32 suctions the item W, the suction port 39b is blocked by the item W, preventing air from flowing in, and the negative pressure within the suction pad 39 increases. This negative pressure has a value corresponding to the suction force acting on the item W. Therefore, the negative pressure within the suction unit 32 reflects the suction force acting on the item W. The pressure switch 98 turns off when the detected negative pressure is a small value below the threshold, and turns on when the detected negative pressure is a large value above the threshold. When the pressure switch 98 switches from off to on, the control unit 100 determines that excessive suction force has been applied to the item W by the suction unit 32. The threshold at which the pressure switch 98 turns on may be changed depending on the strength of the item W. For example, if the article W is a second article that is more easily broken than the first article, the second threshold value is set to a value smaller than the first threshold value set in the pressure switch 98 when the article W is the first article.

[0150] The control unit 100 is also electrically connected to the robot 20, blower 28, electromagnetic on-off valve 85, flow rate adjustment valve 86, lifting cylinder 36, first cylinder 57, second cylinder 47, and opening / closing cylinder 62 as an output system. The control unit 100 controls the drive of the robot 20, blower 28, electromagnetic on-off valve 85, flow rate adjustment valve 86, lifting cylinder 36, first cylinder 57, second cylinder 47, and opening / closing cylinder 62, etc., at predetermined timing according to a program.

[0151] The control of the transfer device 10 performed by the control unit 100 is basically the same as in the first embodiment, but the control content differs from that of the first embodiment in the following respects. That is, in this embodiment, the suction unit 32 is of a suction type using the blower 28 as a negative pressure source, and the pair of receiving units 80 can be opened and closed without interfering with the rollers 16 of the conveyor 12. These differences result in some control content differences due to configurations different from those of the first embodiment. The detailed control content of the control unit 100 will be described later.

[0152] <Operation of the Second Embodiment> Next, the operation of the transfer device 10 will be described with reference to Figures 26 to 33, etc. Note that the steps shown in Figures 26 to 33 show the process in which the suction mechanism 30 picks up the article W on the roller conveyor 12 by suction at the pick-up position, and the process in which the article W is placed on the roller conveyor 12 at the placement position. Here, the roller conveyor 12 at the pick-up location and the roller conveyor 12 at the placement location may be different. Note that in an example of a de-stack operation in which the robot 20 transfers articles W one by one from the top layer of a group of articles on a pallet P onto the roller conveyor 12 as the transfer operation, the placement operation described below can be used. Furthermore, in an example of a stacking operation in which articles W are loaded onto a pallet P as the transfer operation, the robot 20 can be made to pick up the articles W one by one from the roller conveyor 12.

[0153] The basic control details, such as speed control of the lifting cylinder 36, are the same as those in the first embodiment. Below, a description will be given of a loading operation for loading an article W on the roller conveyor 12 using the suction mechanism 30 of this embodiment, and a loading operation for loading the attracted article W onto the roller conveyor 12. First, the loading operation will be described with reference to Figures 26 to 30.

[0154] First, the control unit 100 drives the robot arm 23 to move the suction unit 32 to the pickup start position ( FIG. 26 ), which is a predetermined height position above the pickup position. When the control unit 100 determines that the suction mechanism 30 has reached the pickup start position, the robot 20 stops the movement of the suction mechanism 30. At this pickup start position, the pair of receiving parts 80 are in an open state, and the suction force of the suction unit 32 is stopped. The control unit 100 puts the suction unit 32 in a tiltable and slidable state. Specifically, the control unit 100 drives the first cylinder 57 from a contracted state ( FIG. 20 ) to an extended state, and drives the second cylinder 47 from an extended state to a contracted state ( FIG. 22 ). As a result, the suction unit 32 is allowed to slide in the X direction and to slide about both the first axis 42 (X axis) and the second axis (Y axis).

[0155] 27, the control unit 100 lowers the suction unit 32. That is, the control unit 100 extends the lifting cylinder 36 to lower the suction unit 32. During this lowering process, the control unit 100 drives the blower 28 to generate a suction airflow at the suction port 39b of the suction unit 32. When the suction unit 32 comes into contact with the item W, it adsorbs the item W.

[0156] For example, if an item W is tilted because it overlaps with an adjacent item W, the suction unit 32 that comes into contact with the item W during the descent process tilts, sliding toward the less tilted side of the item W. The suction unit 32 adsorbs the item W by abutting the entire surface of the tilted item W to be adsorbed. The control unit 100 detects that the suction unit 32 has adsorbed the item W when the detected pressure (detected negative pressure) of the first sensor 73 exceeds a threshold value.

[0157] Next, when the control unit 100 detects suction, it drives the opening / closing cylinder 62 from the contracted state to the extended state while the article W remains on the roller conveyor 12. As a result, as shown in FIG. 29, the receiving mechanism 60 closes from the open state to the closed state, allowing the pair of receiving portions 80 to receive the article W from below while it remains on the roller conveyor 12. At this time, if the receiving mechanism 60 is closed with the suction portions 32 lowered as shown in FIG. 27, the pair of receiving portions 80 may interfere with the article W. Therefore, while the article W remains on the roller conveyor 12, the suction mechanism 30 may be lowered and the suction portions 32 may be raised simultaneously at the same speed, resulting in the state shown in FIG. 28. In the state shown in FIG. 28, the suction portions 32 are pulled toward the rotation center (upper side) of the receiving mechanism 60. If the receiving mechanism 60 is closed from this state, the pair of receiving portions 80 are less likely to interfere with the article W. At this time, the multiple hook members 81 constituting the pair of receiving portions 80 are inserted into the gap between the rollers 16, as shown in Figure 20. However, if the receiving mechanism 60 is completely closed in this state, there is a risk that part of the link mechanism 63 will interfere with the rollers 16. For this reason, the ascent of the suction mechanism 30, the descent of the suction portion 32, and the closing operation of the receiving mechanism 60 may be simultaneously controlled while keeping the insertion depth of the hook members 81 relative to the rollers 16 within a predetermined range, thereby transitioning to the state shown in Figure 29 while the article W remains on the roller conveyor 12. By appropriately combining the above operations, the article W can be received from below while remaining on the roller conveyor 12, as shown in Figures 21 and 29.

[0158] Then, as shown in FIG. 30, the article W adsorbed by the adsorption portion 32 can be lifted up from the roller conveyor 12 with the pair of receiving members 61 receiving the article W from below. In this way, when the suction unit 32 picks up an article W on the roller conveyor 12, the robot 20 lowers the suction mechanism 30 to a pick-up position where the article W on the roller conveyor 12 can be picked up with the pair of receiving members 61 in an open state. After the suction mechanism 30 is lowered, the suction unit 32 performs a suction operation to pick up the article W, and the receiving mechanism 60 performs a closing operation to close the pair of receiving members 61. During this closing operation, the hook member 81 is partially inserted between the rollers 16 of the roller conveyor 12. Therefore, the article W on the roller conveyor 12 can be lifted up from the pick-up position with the article W received from below by the pair of receiving units 80.

[0159] Next, with reference to Figures 30 to 33, the loading operation of placing an article W on the roller conveyor 12 will be described. As shown in Figure 30, the article W is transferred while being sandwiched between a pair of receiving members 61 and the suction part 32. During transfer, the suction part 32 is returned to the center position in the sliding direction and is locked in a horizontal position where it cannot tilt.

[0160] After transferring the article W, it is assumed that the suction mechanism 30 is placed at the placement start position shown in Figure 30. At the start of the placement operation, the control unit 100 may set the suction unit 32 in a state in which it can slide and tilt.

[0161] As shown in Fig. 31, the control unit 100 controls the arm 23 of the robot 20 to lower the suction mechanism 30. The suction mechanism 30 is lowered until the article W is placed on the roller conveyor 12. As shown in Fig. 31, the article W is placed on the roller conveyor 12 while being received from below by the pair of receiving parts 80. At this time, the pair of receiving parts 80 can receive the article W on the roller conveyor 12 from below at a position below the rollers 16 by inserting the multiple hook members 81 into the gaps between the rollers 16 as shown in Fig. 20.

[0162] For example, in the first embodiment, in the loading process, it is necessary to first open the pair of receiving members 61 before placing the article W on the roller conveyor 12. For this reason, it is necessary to either slide the article W onto the placement surface Pa while opening the pair of receiving members 61 (FIGS. 16 and 17), or to lower the article W adsorbed to the suction portions 32 while the pair of receiving members 61 is open and place it on the roller conveyor 12. In this case, there is a risk of impact being applied to the article W when it slides down, or of impact being applied to the article W when it comes off the suction portions 32 during the descent. In contrast, in this embodiment, the article W can be placed on the roller conveyor 12 while it is supported from below by the pair of receiving portions 80, so there is no need to worry about impact being applied to the article W.

[0163] As shown in Figure 32, after placing the article W on the roller conveyor 12, the receiving mechanism 60 is opened. At this time, the hook member 81 of the receiving mechanism 60 is partially inserted into the gap between the rollers 16. Therefore, the hook member 81 of the receiving part 80 in the closed state does not interfere with the rollers 16, and the article W can be placed on the roller conveyor 12.

[0164] Furthermore, as shown in FIG. 33, the suction portion 32 is raised with the suction force stopped. This completes the load placement operation. The receiving mechanism 60 may be opened from the position shown in FIG. 31, but the suction portion 32 may be raised first with the suction force stopped, and then the receiving mechanism 60 may be opened. In this case, if the pair of receiving portions 80 are opened from the position shown in FIG. 31, the end of the article W will be resting on the hook members 81, which may cause the article W to be dragged and shifted. Therefore, the pair of receiving portions 80 may be lowered from the position shown in FIG. 31 before being opened. By doing so, the pair of receiving portions 80 open after the hook members 81 move downward away from the article W, eliminating the risk of the article W being shifted by the opening movement of the hook members 81.

[0165] In this way, when placing the article W adsorbed by the suction portion 32 on the roller conveyor 12, the robot 20 lowers the suction mechanism 30 to a placement position where the hook member 81 is partially inserted between the rollers 16 of the roller conveyor 12. After this descent of the suction mechanism 30, the suction portion 32 performs a suction release operation to release the suction of the article W, and the receiving mechanism 60 performs an opening operation to open the pair of receiving portions 80. Therefore, the article W can be received from below by the pair of receiving portions 80 until it is placed at the placement position on the roller conveyor 12.

[0166] When the pressure switch 98 is turned on during the loading or unloading operation, the control unit 100 increases the opening of the flow rate adjustment valve 86 to increase the amount of leakage. As a result, the negative pressure acting on the item W being adsorbed by the adsorption unit 32 is weakened. Therefore, even if an excessive negative pressure (suction force) acts on the item W being adsorbed by the adsorption unit 32 for some reason, the negative pressure is immediately weakened, making it less likely that the item W will be damaged. For example, if the item W is a bag, tearing of the bag can be avoided.

[0167] In addition, when the transfer device 10 picks up an item W placed on a loading surface Pa other than the roller conveyor 12, and when it places an item W on a loading surface Pa other than the roller conveyor 12, the picking up and placing of the item is performed using the same operations and controls as in the first embodiment.

[0168] <Effects of the second embodiment> As described above in detail, according to this embodiment, in addition to the effects (1-1) to (1-8) of the first embodiment, the following effects are also obtained.

[0169] (2-1) The suction unit 32 is configured to be able to suction the article W with suction airflow generated by the blower 28 as a negative pressure source. The suction mechanism 30 has a flow rate adjustment valve 86 as an example of a flow rate adjustment unit that can adjust the negative pressure acting on the article W when it is suctioned by the suction unit 32 by the amount of leakage of the suction airflow. This configuration makes it possible to adjust the suction airflow, which determines the suction force acting on the article W suctioned by the suction unit 32, depending on the strength of the article W. This makes it possible to ensure reliable suction for multiple types of articles W with different strengths while avoiding damage to the article W. If the article W is, for example, a bag containing contents, it is possible to prevent the bag from breaking due to excessive suction force.

[0170] (2-2) A pressure switch 98 is provided as an example of a detector capable of detecting excessive negative pressure, in which the negative pressure acting on the suction unit 32 exceeds a negative pressure threshold. When the pressure switch 98 detects excessive negative pressure, the flow rate adjustment valve 86 increases the leakage flow rate to adjust the negative pressure acting on the article W to a smaller value. With this configuration, it is possible to prevent excessive negative pressure from acting on the article W for some reason, while the suction airflow is adjusted so that the negative pressure acting on the suction unit 32 becomes a negative pressure appropriate for the type of article W.

[0171] (2-3) The pair of receiving members 61 includes a plurality of hook members 81 and a spacing change mechanism 82. More specifically, the pair of receiving members 61 includes a receiving portion 80. The receiving portion 80 includes a plurality of hook members 81 and a spacing change mechanism 82. The plurality of hook members 81 are arranged at intervals in the first direction (X direction) at the tip end portion. The spacing change mechanism 82 is configured to change the spacing between the plurality of hook members 81. With this configuration, the pair of receiving members 61 receive the article W with the plurality of hook members 81, and therefore can receive the article W more reliably than a receiving member 61 without hook members 81. Furthermore, when removing an article W from the roller conveyor 12 or placing an article W on the roller conveyor 12, the hook members 81 can be inserted into the gap G between the rollers 16. For example, by changing the spacing (or pitch HP) of the hook members 81 according to the spacing (or pitch RP) of the rollers 16 of the roller conveyor 12, the hook members 81 can be partially inserted into the gap G between the rollers 16. Therefore, an article W can be placed on the roller conveyor 12 while the pair of receiving members 61 is in a closed state, or the adsorbed article W can be lifted up after the pair of receiving members 61 is closed.

[0172] (2-4) When placing the item W adsorbed by the suction portion 32 on the roller conveyor 12, the robot 20 lowers the suction mechanism 30 to a placement position where the hook member 81 is partially inserted between the rollers 16 of the roller conveyor 12. After this descent, the suction portion 32 performs a suction release operation to release the suction of the item W, and the receiving mechanism 60 performs an opening operation to open the pair of receiving members 61. With this configuration, the pair of receiving members 61 can receive the item W until it is placed, or can receive the item W for as long as possible until just before it is placed. Therefore, even if the item W comes off the suction portion 32 during placement, the impact of a fall on the item W can be avoided or reduced.

[0173] (2-5) When the suction unit 32 picks up an article W on the roller conveyor 12, the robot 20, which is an example of a moving mechanism, lowers the suction mechanism 30 to a pick-up position where the article W on the roller conveyor 12 can be picked up with the pair of receiving members 61 in an open state, and then performs a suction operation in which the suction unit 32 picks up the article W, and a closing operation in which the receiving mechanism 60 closes the pair of receiving members 61. During the closing operation, the hook member 81 is partially inserted between the rollers 16 of the roller conveyor 12. According to this configuration, the article W picked up by the suction unit 32 can be lifted up from the roller conveyor 12 with the pair of receiving members 61 in a closed state.

[0174] The embodiment is not limited to the above and may be modified as follows. In the above-described embodiment, the drive unit for opening and closing the pair of receiving members 61 may be omitted. Even without the opening / closing cylinder 62, which is an example of a drive unit, the pair of receiving members 61 can be opened and closed by utilizing their own weight or the reaction force they receive from the article W. For example, the suction mechanism 30 shown in FIGS. 34 to 37 does not include the opening / closing cylinder 62, which is an example of a drive unit. In this case, as shown in FIG. 34, when the lower ends of the pair of receiving members 61 come into contact with the article W, they receive a reaction force from the surface of the article W to be attracted. Furthermore, as shown in FIG. 35, when the suction mechanism 30 is lowered, the pair of receiving members 61 open due to the reaction force, and their lower ends sandwich the article W (indicated by the two-dot chain line in FIG. 35). From this state, the lifting cylinder 36 is extended, causing the suction unit 32 to descend and attract the article W. Next, as shown in FIG. 36, the robot arm 23 raises the suction mechanism 30 to a predetermined height, causing the pair of receiving members 61 to close under their own weight. Furthermore, as the suction unit 32 descends at the second speed V2 (low speed), the article W is placed on the upper surfaces of the pair of receiving members 61. Then, the weight of the article W is also applied to the pair of receiving members 61, increasing the force acting in the closing direction on the pair of receiving members 61. Therefore, while the robot arm 23 is transporting the suction mechanism 30 to the loading position, the pair of receiving members 61 are kept in the closed state by a relatively strong force due to their own weight. Then, as shown in FIG. 37 , at the loading position, the robot arm 23 lowers the suction mechanism 30 at a low speed, causing the pair of receiving members 61 to gradually open from the closed state due to the reaction force received from the conveyor 12. At this time, the article W slides down the slopes of the pair of receiving units 70 and is placed on the conveyor 12. Then, when the robot arm 23 raises the suction mechanism 30, the pair of receiving members 61 close due to their own weight. In this way, even if a configuration does not include a drive unit such as an opening / closing cylinder 62, the pair of receiving members 61 can be opened and closed by using their own weight and the reaction force. Therefore, according to this transfer device, by eliminating drive parts such as the open / close cylinder 62, it is possible to reduce the number of drive system parts and reduce the control load of the control unit 100.

[0175] The configuration in which the suction unit 32 and the receiving member 61 move relatively toward or away from each other in the vertical direction Z may be such that the receiving member 61 moves up and down instead of the suction unit 32 moving up and down. Furthermore, the suction unit 32 and the receiving member 61 may both move toward each other or move away from each other.

[0176] In the above embodiment, the suction unit 32 is lowered to place the article W on the upper surface of the pair of receiving members 61 in the closed state, but the suction of the suction unit 32 may be released at the raised position to drop the article W onto the upper surface of the pair of receiving members 61 in the closed state. Alternatively, the article W may be lowered to a position halfway between the raised position and the lowered position, and then the suction of the suction unit 32 may be released to drop the article W a shorter distance from a position lower than the raised position toward the upper surfaces of the pair of receiving members 61.

[0177] The second embodiment may have a distance changing mechanism 82 that can change the distance (or pitch HP) between the plurality of hook members 81 using the power of a drive source. Examples of the power source include a pneumatic cylinder or a motor.

[0178] The suction unit 32 may suction the item W while a moving mechanism such as the robot 20 is transporting the item W. For example, if the suction force is weaker than that during pick-up or placement, damage or suction marks on the item W caused by the suction force can be reduced. For example, the item W may be sandwiched between the suction unit 32 and a pair of receiving members 61. Furthermore, when the item W is sandwiched between the suction unit 32 and the pair of receiving members 61, the suction of the suction unit 32 may be released. Furthermore, whether or not the suction of the suction unit 32 is released during transportation may be switched depending on the type of the item W. Furthermore, the suction force of the suction unit 32 during transportation may be maintained at the same suction force as that during pick-up or placement.

[0179] The timing of the closing operation in the second embodiment may be any time as long as the hook member 81 is partially inserted between the rollers 16 during the closing operation. The closing operation may be performed before, simultaneously with, or after suction. After suction, the closing operation may be performed after the lifting mechanism 35 starts to lift the suctioned article W from above the roller conveyor 12, when the suction mechanism 30 is in the unloading position, or after the suction mechanism 30 starts to rise from the unloading position. Note that the closing operation is preferably performed while the article W is on the roller conveyor 12 or while the article W is within 5 cm of the roller conveyor 12.

[0180] In the second embodiment, the driving source of the blower 28 is not limited to the vacuum pump 29. The blower 28 may be any compressor, which is a machine that compresses and feeds gas by the rotational motion of an impeller or rotor or the reciprocating motion of a piston, as long as the effective discharge pressure is 200 kPa or less. The vacuum pump 29, which is the driving source of the blower 28, may be, for example, a claw pump, a vane pump, a multi-stage roots pump, a scroll pump, or a screw pump. The blower 28 in this specification may also be a fan (air blower). A fan is a machine that imparts energy to gas by the rotational motion of an impeller, and has an energy per unit mass of less than 25 kNm / kg.

[0181] The link mechanism 63 is not limited to a scissors mechanism. Furthermore, the link mechanism 63 is not limited to a pantograph mechanism including a scissors mechanism. In short, the link mechanism 63 may be any mechanism that can open and close the pair of receiving members 61. In this respect, a power transmission mechanism other than the link mechanism 63 may be used. Furthermore, the pair of receiving members 61 may be fixed to the output shaft of the drive unit without using a power transmission mechanism. For example, a configuration may be used in which the bases of the pair of receiving members 61 that intersect at a rotation axis are fixed to the tip ends of the rods of a double-rod cylinder.

[0182] In the above embodiment, the slide mechanism 50 is configured so that the suction portion 32 can slide only in the longitudinal direction (X direction) of the article W, but the slide mechanism 50 may also be configured so that the suction portion 32 can slide only in the lateral direction (Y direction) of the article W. Also, the slide mechanism 50 may be configured so that the suction portion 32 can slide in both the X direction and the Y direction. In these cases, a center return mechanism may also be provided in the Y direction.

[0183] The joint mechanism 41 in the tilt mechanism 40 may be a universal joint. Also, the joint mechanism 41 may be a single-shaft joint instead of a cross joint. In the locking mechanism 46, the suction part 32 may be biased by a spring in a direction to return to the horizontal position. For example, the locking mechanism 46 includes four springs arranged at the four corners of the restricting plate 49. The springs are compression springs, and are displaced and compressed or expanded in response to the tilting of the suction part 32. The suction part 32 can tilt against the biasing force of the springs, and can be returned to the horizontal position by the biasing force of the springs.

[0184] A return spring may be provided instead of the center return mechanism 56. The biasing force of the return spring returns the tilting fulcrum of the suction part 32 to a reference position (for example, a center position) in the sliding direction. The slide mechanism 50 slides horizontally, but if the adsorption part 32 is tilted, the slide mechanism 50 may slide the adsorption part 32 along the tilt direction.

[0185] The slide shaft constituting the slide mechanism 50 is not limited to a configuration in which it also serves as the shaft of the joint mechanism 41 that supports the suction part 32 so that it can tilt, but may be a slide shaft dedicated to sliding that is separate from the joint mechanism.

[0186] The drive unit may be a motor instead of the opening / closing cylinder 62. The slide mechanism 50 may not be provided. The locking mechanism 46 may not be provided.

[0187] The tilting mechanism 40 may not be provided. The suction portion 32 is not limited to the suction pad 39. The suction portion 32 may be a suction plate without the pad portion 39a. Even with this configuration, it is possible to prevent a decrease in the durability of the suction plate due to suction of the article W during transportation, and to prevent damage to the article W or the leaving of suction marks due to the suction force.

[0188] Instead of detecting the position of the article W by analyzing the image captured by the camera 91, the position of the article W may be detected by a distance sensor or the like provided on the robot arm 23 or the suction mechanism 30.

[0189] The article W is not limited to a bag, but may be a case such as a box. The shape of the article other than the bag is not limited to a rectangular parallelepiped, but may be other polygonal prisms (for example, triangular prisms or hexagonal prisms) or cylindrical. The suction mechanism 30 may be configured to include a plurality of suction pads 39 so as to suck up a plurality of articles W at a time, or a plurality of suction pads 39 may suck up one article W.

[0190] The transfer operation of the item transfer device can be conveyor-to-conveyor transfer, or pallet-to-pallet transfer. It can also be transfer between a pallet and a cart, or between a cart and a conveyor. In this way, when the item transfer device performs a transfer operation, the items can be placed anywhere.

[0191] The movement mechanism is not limited to the robot 20. For example, it may have an X movement mechanism, a Y movement mechanism, and a Z movement mechanism, and move the suction mechanism 30 in the X, Y, and Z directions. The movement mechanism may be a Z movement mechanism that moves only in the height direction Z (lifting direction). Furthermore, if the suction mechanism 30 is configured to include the lifting mechanism 35, the movement mechanism may be an X movement mechanism that moves only in the X direction, or a Y movement mechanism that moves only in the Y direction. Furthermore, it may be a movement mechanism that moves in only two of the X, Y, and Z directions. Note that if the suction mechanism 30 is configured to include only the X movement mechanism or the Y movement mechanism, the lifting mechanism 35 forms part of the movement mechanism.

[0192] In the first and second embodiments, the operation of lowering the suction part 32 to pick up the article W may be performed by the robot arm 23 lowering the suction mechanism 30, rather than by extending the lifting cylinder 36 that constitutes the lifting mechanism 35. In this case, the lifting cylinder 36 may be in the extended state during the previous loading operation. Also, the operation of lowering the suction part 32 to load the article W may be performed by the robot arm 23 lowering the suction mechanism 30, rather than by extending the lifting cylinder 36 that constitutes the lifting mechanism 35.

[0193] The suction mechanism 30 may not have the lifting mechanism 35. In this case, a movement mechanism such as the robot 20 may move the suction part 32 in the lifting direction. [Explanation of symbols]

[0194] 10...article transfer device (transfer device), 12...conveyor (roller conveyor), 15...input section, 20...robot (articulated robot) as an example of a moving mechanism, 23...robot arm as an example of an arm, 23A to 23C...arm section, 24...drive mechanism, 25...power source, 26...motor, 27...rotating section, 28...blower, 29...vacuum pump, 30...suction mechanism, 31...mechanism main body, 32...suction section, 33...mounted section, 34...support section, 35...lifting mechanism, 36...lifting cylinder, 37...lifting member, 38...negative pressure generating unit, 39...suction pad, 39a...pad portion, 39b...suction port, 40...tilting mechanism, 41...joint mechanism, 42...first shaft, 43...second shaft, 44...connecting member, 45...block, 46...locking mechanism, 47...second cylinder, 48...oscillating member, 49...regulating plate, 50...slide mechanism, 51...regulating member, 55...return mechanism, 56...center return mechanism, 57...first cylinder, 57a...rod, 60...receiving mechanism, 61...receiving member, 62...opening / closing cylinder as an example of a drive unit, 63...link mechanism, 64...support plate, 64a...guide groove, 65 ...First link member, 66...Second link member, 67...Fixed shaft, 68...Connecting shaft, 69...Movable shaft, 70...Receiving portion, 70a...Round pipe, 73...First sensor, 75...Hose, 75A...First hose, 75B...Second hose, 76...Joint member, 77...First piping member, 78...Second piping member, 79...Flexible cable, 80...Receiving portion, 81...Hook member, 82...Spacing change mechanism, 83...Horizontal member, 84...Threaded hole, 85...Electromagnetic opening / closing valve, 86...Flow rate adjustment valve as an example of a flow rate adjustment portion, 86M...Motor, 87, 88...Silencer, 89...filter, 90...imaging device, 91...camera, 96...second sensor, 97...second sensor, 98...pressure switch as an example of a detection unit, 100...control unit, 110...computer, 120...memory, B...bolt, W, W1, W2...item, P...pallet, Pa...loading surface, f1...first driving force, f2...second driving force, V1...first speed, V2...second speed, HP...pitch of hook member, RP...pitch of roller, G...gap, X...X direction (slide direction) as an example of the first direction, Y...Y direction, Z...height direction (vertical direction).

Claims

1. An article transfer device that adsorbs and transfers an article, a suction mechanism having a suction portion capable of suctioning the article; a movement mechanism that moves the suction mechanism in a movement direction including a lifting direction; Equipped with The adsorption mechanism is a receiving mechanism having a pair of receiving members that can be opened and closed via a scissors mechanism between an open state in which the suction section opens to a position that does not interfere with the suction operation of suctioning the article, and a closed state in which the suction section receives the article from below after suctioning and lifting it up; The adsorption portion and the pair of receiving members are configured to move relative to each other in a vertical direction, the suction portion suctions the article when the pair of receiving members are in an open state, the receiving mechanism receives the article by the pair of receiving members in the closed state after the pair of receiving members are closed, by the suction portion and the receiving members moving relatively in a direction approaching each other in a vertical direction; The article transfer device is characterized in that the movement mechanism moves the suction mechanism when the pair of receiving members in the closed state receive the article.

2. 2. The article transfer device according to claim 1, wherein the receiving mechanism includes a drive unit that opens and closes the pair of receiving members.

3. 2. The article transfer device according to claim 1, wherein the receiving mechanism closes the pair of receiving members after the suction portion has lifted up the article.

4. the receiving mechanism closes the pair of receiving members, and then moves the suction portion and the receiving member relative to each other in a direction approaching each other in a vertical direction, thereby placing the article on the pair of receiving members, and then moves the suction portion and the receiving member, which have released suction, relative to each other in a direction separating them in the vertical direction; The article transfer device according to claim 3, wherein the moving mechanism moves the suction mechanism when the suction of the suction portion is released and the pair of receiving members receive the article from below.

5. a tilting mechanism that supports the adsorption unit so that the adsorption unit can tilt; a locking mechanism that can switch the tilting mechanism between an unlocked state that allows tilting of the suction unit and a locked state that locks the suction unit in a horizontal position; The article transfer device described in claim 1, characterized in that after the pair of receiving members are closed, the suction portion and the pair of receiving members move relative to each other in a vertical direction while the suction portion is locked in a horizontal position, thereby placing the article on the pair of receiving members in the closed state.

6. In the process of the suction operation of suctioning the article, the suction unit is lowered from a raised position to a suction position by a first driving force; When the suction unit at the suction position is lowered until it adsorbs the article, the suction unit is lowered by a second driving force that is weaker than the first driving force; 2. The article transfer device according to claim 1, wherein when the article that has been sucked up by the suction portion is placed on the pair of receiving members that are in the closed state, the suction portion is lowered by the second driving force.

7. the suction unit is configured to be able to suction the article with a suction airflow generated by a blower as a negative pressure source, 2. The article transfer device according to claim 1, wherein the suction mechanism has a flow rate adjusting section that can adjust the negative pressure acting on the article when it is sucked by the suction section by changing the leakage flow rate of the suction airflow.

8. a detection unit capable of detecting an excessive negative pressure in which the negative pressure acting on the suction unit exceeds a negative pressure threshold; 8. The article transfer device according to claim 7, wherein the flow rate adjusting unit adjusts the negative pressure acting on the article to a smaller value by increasing the leakage flow rate when the detecting unit detects the excessive negative pressure.

9. The pair of receiving members have a plurality of hook members arranged at intervals in the first direction at their distal end portions, 2. The article transfer device according to claim 1, further comprising a spacing change mechanism configured to change the spacing between the plurality of hook members.

10. When the article attracted to the suction portion is to be placed on the roller conveyor, the moving mechanism lowers the suction mechanism to a placement position where the hook member is partially inserted between the rollers of the roller conveyor, and then a suction release operation in which the suction unit releases suction of the article; an opening operation in which the receiving mechanism opens the pair of receiving members; The article transfer device according to claim 9, wherein the article transfer device performs the following steps.

11. When the suction unit picks up the article on the roller conveyor, The moving mechanism lowers the suction mechanism to a pickup position where the suction mechanism can suction the article on the roller conveyor while the pair of receiving members are in an open state, and then a suction operation in which the suction unit suctions the article; a closing operation in which the receiving mechanism closes the pair of receiving members; and 10. The article transfer device according to claim 9, wherein the hook member is partially inserted between the rollers of the roller conveyor during the closing operation.

12. An adsorption mechanism that can be attached to an arm of an articulated robot and that moves in a movement direction including a vertical movement direction by the articulated robot, a mounting portion that can be mounted on the arm; an adsorption portion capable of adsorbing an article; a receiving mechanism having a pair of receiving members that can be opened and closed via a scissors mechanism between an open state in which the suction portion opens to a position that does not interfere with the suction operation of suctioning the article, and a closed state in which the suction portion receives the article from below after suction and lifting it up; Equipped with the suction mechanism is configured so that the suction portion and the pair of receiving members move relative to each other in a vertical direction; the suction portion suctions the article when the pair of receiving members are in an open state, The receiving mechanism is characterized in that after the pair of receiving members are closed, the suction portion and the receiving members move relative to each other in a direction vertically approaching each other, thereby receiving the item with the pair of receiving members in the closed state.

13. A suction mechanism having a suction portion capable of suctioning an article; a movement mechanism that moves the suction mechanism in a movement direction including a lifting direction; An article transfer method for adsorbing and transferring an article by controlling an article transfer device including: The adsorption mechanism is a receiving mechanism having a pair of receiving members that can be opened and closed via a scissors mechanism between an open state in which the suction section opens to a position that does not interfere with the suction operation of suctioning the article, and a closed state in which the suction section receives the article from below after suctioning and lifting it up; The adsorption portion and the pair of receiving members are configured to move relative to each other in a vertical direction, The computer a suction step of suctioning and lifting the article by the suction portion while the pair of receiving members are in an open state; a receiving step of receiving the article by the pair of receiving members in the closed state by relatively moving the suction portion and the receiving members in a direction approaching each other in a vertical direction after the pair of receiving members are closed; a transport step of moving the suction mechanism by the moving mechanism while the pair of receiving members in the closed state receive the articles.

Images