JP2024080654A - Article transfer device, suction mechanism, and article transfer method - Google Patents

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

Application for exception to loss of novelty has been filed

The present invention relates to an article transfer device, a suction mechanism, and an article transfer method for transferring articles.

For example, Patent Document 1 discloses an article transfer device in which a robot performs transfer work by suctioning and transferring articles one by one. This article transfer device is equipped with a suction mechanism having a suction part such as a suction pad at the tip of the robot's arm. The suction mechanism is configured so that the suction part can be tilted and slid. The suction mechanism also includes a receiving mechanism that receives the article that has been sucked onto the suction part from below. The article transfer device then transports the article that has been sucked onto the suction part while it is supported from below by the four plates of the receiving mechanism, by the robot moving the suction mechanism.

JP 2022-92793 A

However, in the article transfer device described in Patent Document 1, the four plates of the receiving mechanism are flat plates arranged horizontally, so that the article is easily slippery during transfer. Therefore, even during transfer, the suction part is maintained in a state of adsorption in which the suction force at the time of loading is used to adsorb the article. The pad part constituting the suction part is made of a rubber material or a synthetic resin material having rubber elasticity. In a state in which the suction part is adsorbing an article, a high negative pressure is applied to the pad part. As a result, the suction part deteriorates faster the higher the suction frequency and the longer the suction time. In the article transfer device described in Patent Document 1, since the receiving mechanism is in a state in which it receives an article, it is possible to transfer the article with the suction of the suction part released. However, since the four plates of the receiving mechanism support the article from below as an auxiliary, it is difficult to transfer the article with the suction of the suction part released or weakened. In addition, even if the suction of the suction part is maintained, it may be difficult to stably hold the article during transfer due to other factors such as the shaking of the article during transfer. Therefore, an article transfer device that can transfer the article while firmly supporting it from below is desired.

The means for solving the above problems and their effects will be described below.
The article transfer device that solves the above problem is an article transfer device that adsorbs and transfers an article, and includes an adsorption mechanism having an adsorption part capable of adsorbing the article, and a moving mechanism that moves the adsorption mechanism in a moving direction including a lifting direction, and the adsorption 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 part opens to a position that does not interfere with the adsorption operation of adsorbing the article, and a closed state in which the adsorption part adsorbs and lifts the article from below, and the adsorption part adsorbs the article when the pair of receiving members are in the open state, and the moving mechanism moves the adsorption 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, and the pair of receiving members may be spaced apart from each other at a position where they have moved relatively in the closing direction compared to the open state. In short, the pair of receiving members may be spaced apart from each other or in contact with each other as long as they can receive an article, and the distance between them is small enough to receive an article in the closed state compared to the open state.

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

In the above-mentioned 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 at the required timing by the drive unit. For example, the pair of receiving members can be opened while the suction unit is suctioning the article, and the pair of receiving members can be closed after the article is suctioned and lifted up.

In the above-mentioned article transfer device, the receiving mechanism may close the pair of receiving members after the suction portion lifts up the article.
According to this configuration, the pair of receiving members close after the suction portions lift up the article, so that the article can be received by the closed pair of receiving members.

In the above-mentioned article transfer device, the receiving mechanism closes the pair of receiving members, and then moves the suction part and the receiving member relatively in a direction vertically approaching each other, thereby placing the article on the pair of receiving members, and then moves the suction part and the receiving member, which have released the suction, relatively in a direction vertically separating them, and the moving mechanism may move the suction mechanism when the suction part is released and the pair of receiving members receive the article from below.

According to this configuration, the article can be transferred in a state where the suction by the suction part is released and the article is received by the receiving member, so deterioration such as wear of the suction part can be suppressed.
The article transfer device is equipped with a tilting mechanism that supports the suction part so that it can be tilted, and a locking mechanism that can switch the tilting mechanism between an unlocked state that allows the suction part to tilt and a locked state that locks the suction part in a horizontal position, and after closing the pair of receiving members, with the suction part locked in a horizontal position, the suction part 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.

With this configuration, the tilting mechanism is locked, allowing the item 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 item is placed on the pair of receiving members in an inclined position that is inclined from the horizontal, the article is less likely to shift in position or position when placed at the transfer destination. In other words, the item can be placed in an appropriate position with minimal shifting and in an appropriate position.

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

According to this configuration, before an article is adsorbed, the suction part is quickly lowered to the adsorption position with a first driving force, and when the suction part in the lowered position adsorbs an article, the suction part contacts the article with a weak pressure. In addition, when the article is placed on the receiving member, the suction part is lowered with a second driving force that is smaller than the first driving force, so that the pressing force with which the suction part presses the article when placing the article on the receiving member is small.

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

With this configuration, the suction airflow that determines the suction force acting on the item adsorbed to the suction section can be adjusted according to the strength of the item. This makes it possible to avoid damage to multiple types of items with different strengths while ensuring reliable adsorption. For example, if the item is a bag that contains contents, tearing of the bag due to excessive suction force can be avoided.

The article transfer device may include 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 the flow rate adjustment unit may adjust the negative pressure acting on the article to a smaller value by increasing the leak flow rate when the detection unit detects the excessive negative pressure.

This configuration makes it possible to prevent excessive negative pressure from being applied to the item for some reason while adjusting the suction airflow so that the negative pressure applied to the suction section is a negative pressure appropriate to the type of item.

In the above-mentioned article transfer device, the pair of receiving members may have a plurality of hook members arranged at intervals in a first direction at the tip end portion, and may be provided with a spacing change mechanism configured to change the spacing between the plurality of hook members.

According to this configuration, the pair of receiving members receive the article with multiple hook members, so the article can be received more reliably than with a receiving member without hook members. Furthermore, when removing an article from the roller conveyor or placing an article on the roller conveyor, the hook members can be inserted into the gap 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 gap between the rollers. Therefore, an article can be placed on the roller conveyor while the pair of receiving members are in a closed state, or an article that has been attracted can be removed by lifting it up after the pair of receiving members close.

In the above-mentioned article transfer device, when the article adsorbed to the suction section is placed on the 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 adsorption release operation in which the suction section releases the adsorption of the article, and an opening operation in which the receiving mechanism opens the pair of receiving members.

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 it is placed. Therefore, even if the item comes off the suction part when it is placed, the impact of the item being dropped can be avoided or suppressed.

In the above-mentioned item transfer device, when the suction unit picks up the item on the roller conveyor, the moving mechanism, with the pair of receiving members in an open state, lowers the suction mechanism to a pick-up position where the item on the roller conveyor can be picked up, and then performs a suction operation in which the suction unit picks 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.

According to this configuration, the article adsorbed by the suction 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 an attachment part that can be attached to an arm of a multi-joint robot serving as the moving mechanism, an suction part that can suction an item, and a receiving mechanism having a pair of receiving members that are configured to be opened and closed via a scissors mechanism into 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 adsorbs the item in the open state in which 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 multi-joint robot transports the item.

According to this configuration, deterioration of the suction portion can be suppressed 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-mentioned 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, wherein the adsorption mechanism has a pair of receiving members that are configured to 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 adsorbing the article, and a closed state in which the article adsorbed and pulled up by the adsorption portion is received from below, and the method includes the following steps: an adsorption step in which the adsorption portion adsorbs and pulls 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 are closed to the closed state by the receiving mechanism, 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.

This method allows items to be transported while being firmly supported from below.

The present invention allows items to be transported while being firmly supported from below.

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

First Embodiment
Hereinafter, a first embodiment of the article transfer device will be described with reference to the drawings. In FIG. 1, the two directions that define the placement surface on which the 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 that intersects with the X direction and the Y direction and is 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 stages is the placement surface Pa. The height direction Z is a direction perpendicular to the placement surface Pa on which the articles W are placed. The direction perpendicular to the height direction Z is called the horizontal direction. In this example, the horizontal direction is a direction parallel to the placement surface Pa.

As shown in FIG. 1, the article transfer device 10 (hereinafter, simply referred to as the "transfer device 10") picks up the articles W one by one from a group of articles in which a plurality of articles W are stacked on a pallet P at a loading position where the articles should be picked up, carries them to the conveyor 12, and performs a transfer operation (de-stack operation) by releasing the suction and placing the articles W at a loading position on the conveyor 12 at which the articles should be placed. The transfer device 10 also picks up the articles W at the loading position conveyed by the conveyor 12 one by one and carries them to the pallet P, and releases the suction to place the articles W at a loading position on the pallet P or on other articles W stacked on the pallet P. In both cases of the de-stack operation and the stack operation, the transfer device 10 picks up and holds the articles W at the loading position, transports the articles W from the loading position to the loading position, and releases the suction to place the articles W at the loading position.

As shown in FIG. 1, the transfer device 10 includes a robot 20 as an example of a moving mechanism for moving 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 loading 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 granules (for example, grains). Specifically, the contents of the bag may be food powder (such as flour) or granules (such as seeds of beans), or industrial powder or granules such as cement powder. The bag may also contain liquid or gas.

The transfer device 10 is equipped with an imaging device 90 including a camera 91 capable of imaging 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, or to a predetermined position of the robot arm 23, or to a predetermined position of the suction mechanism 30. In the example of FIG. 1, the camera 91 is disposed at a predetermined height near the ceiling. The transfer device 10 performs image analysis processing to analyze an image captured from directly above the group of objects by the camera 91, thereby acquiring at least one of position information including the XY coordinate position and height position of the attracted surface, which is the upper surface to which the object W is attracted 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 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 that fixed position information input and set in advance is used.

As shown in FIG. 1, the robot 20 is an articulated industrial robot that includes a platform 21 arranged on the top surface of an installation stand 13 installed on the floor, a rotating platform 22 that can rotate about a vertical axis relative to the platform 21, and a multi-jointed robot arm 23 supported by the rotating platform 22. In other words, the robot 20 is an articulated robot. The suction mechanism 30 is attached to the tip of the robot arm 23. The robot 20 uses the suction mechanism 30 to suck and grasp the topmost item W of a group of items on a pallet P, and performs a transfer operation (de-stack operation) in which the grasped item W is placed at a predetermined position (loading position) on the conveyor 12.

The robot arm 23 rotates about an axis together with the rotating table 22 by the power of the drive source 25 of the drive mechanism 24 arranged on the side of the base 21. The robot arm 23 also has multiple arm sections 23A to 23C that are connected so that the angle can be changed. The drive source 25 is, for example, an electric motor or an electric cylinder. The angle of the multiple arm sections 23A to 23C is 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 that it can rotate about an axis via a rotating section 27 powered by a motor 26.

As shown in FIG. 1, the suction mechanism 30 has a suction section 32 capable of suctioning an item W. The suction section 32 is capable of suctioning and releasing the suction of 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 unit 100 controls the suction and release of the item W in the suction section 32 by controlling an electromagnetic opening/closing valve (not shown) connected midway through the piping.

As shown in FIG. 1, the suction mechanism 30 includes a receiving mechanism 60 that receives from below the item W picked up by the suction unit 32. The receiving mechanism 60 has a pair of receiving members 61 (only the front one is shown in FIG. 1) that receive the item 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.

In this embodiment, as shown in FIG. 1, the robot 20 transfers the item W with the pair of receiving members 61 receiving the item W. Therefore, during the transfer by the robot 20, the item W is separated from the suction portion 32. Details of the receiving mechanism 60 will be described later.

<Detailed Configuration of Adsorption Mechanism 30>
Next, a 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 due to axial rotation, but in the following description, the direction in which the pair of link mechanisms 63 face each other is defined as the X direction, and the direction perpendicular to the X direction and the Z direction is defined as the Y direction.

As shown in FIG. 2, the suction mechanism 30 is attached to the tip of the robot arm 23 as described above. The suction mechanism 30 includes a mechanism body 31 including a skeletal frame and the like. The mechanism body 31 includes an attachment part 33 that can be attached to the tip of the robot arm 23, a support part 34 fixed to the lower end of the attachment part 33, and a lifting mechanism 35 that supports the suction part 32 so that it can be raised and lowered relative to the support part 34.

The lifting mechanism 35 has 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. The two lifting cylinders 36 extend and retract to raise and lower the suction part 32 supported on the lower side of the lifting member 37.

Between the lifting member 37 and the suction part 32, there are 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, for example, a cross joint.

As shown in FIG. 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 both shafts 42, 43. The connecting member 44 connects both shafts 42, 43 in a state where they intersect at an angle of 90° and can rotate independently. A block 45 protrudes from the upper end of the connecting member 44.

As shown in FIG. 2, the oscillating member 48 extending upward from the top surface of the suction part 32 is connected to the joint mechanism 41 in a state in which it can rotate around the second axis 43. The suction part 32 is supported via the joint mechanism 41 in a state in which it can tilt around two axes, X and Y. 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.

The connecting member 44 is supported so as to be slidable in the X direction along the first shaft 42. This constitutes 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.

The connecting member 44 functions as a slider that can slide in the sliding direction X along the first axis 42. The pair of regulating members 51 define the end positions of both ends of the movement 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 part 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 within a predetermined range along the first axis 42.

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 pad portion 39a having a ring shape at its lower end. The pad portion 39a has, for example, an oval ring shape. The pad portion 39a is made of, for example, an airtight elastic material. The pad portion 39a may be made of rubber, or may be made of synthetic resin made of a porous material (for example, a foam material) having airtightness and elasticity. The lower surface of the suction pad 39 has a suction port 39b surrounded by the pad portion 39a.

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 oscillating member 48. The negative pressure generating unit 38 generates and releases negative pressure at the suction port 39b.

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 via the joint mechanism 41 by the tilting mechanism 40, and the tilting fulcrum can be slid in the X direction by the sliding mechanism 50.

<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 for returning the suction part 32 tilted by the tilting mechanism 40 from the tilted posture to a horizontal posture, and a slide return function for returning 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 be tilted 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.

That is, the center return mechanism 56 switches between a locked state in which the suction part 32 is locked so that it cannot slide at the center position, 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 so that it cannot slide at the center position. The detailed configurations of the center return mechanism 56 and the locking mechanism 46 will be described later.

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 opens and closes between an open state (open position) shown in FIG. 3 in which the item W cannot be held, and a closed state (holding position) shown in FIG. 4 in which the item W can be held.

<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.

As shown in Figures 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 composed of a pantograph mechanism having one fixed end fixed to the support part 34 and two movable ends. The receiving member 61 is fixed to the two movable ends of the link mechanism 63.

As shown in Figures 3 and 4, the suction mechanism 30 has a support plate 64 that extends downward from the center of the support portion 34 in the Y direction. The support plate 64 has a guide groove 64a that extends in the Z direction along the movement path of the rod of the opening/closing cylinder 62.

As shown in Figures 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 a 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 of the rod 62a of the opening/closing cylinder 62 is connected to the movable shaft 69.

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.

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.

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.

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 portion 32 to suction the article W, and a closed state in which they receive the article W that the suction portion 32 has suctioned and pulled up from below. 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.

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 a predetermined angle, the pair of receiving portions 70 are set to a required interval 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 separated by an interval (hereinafter referred to as the "first interval") that can ensure 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 an interval (hereinafter referred to as the "second interval") that can receive the article W lowered by the suction portion 32.

As shown in FIG. 3, the first interval is wider than the short dimension of the item W. As shown in FIG. 4, the second interval is narrower than the short dimension of the item W. When there are multiple sizes of item W, the first interval is wider than the short dimension of a large-sized item W. The second interval is narrower than the short dimension of a small-sized item W.

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 is adsorbed by the suction portion 32 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 contracted, and pulls up the article W to the position shown in FIG. 3.

As shown in FIG. 4, the receiving mechanism 60 closes the pair of receiving members 61 after the suction unit 32 lifts up the item W. That is, after the suction unit 32 lifts up the item W1 to the position shown in the figure, the pair of opening/closing cylinders 62 are driven to contract, causing the pair of receiving members 61 to close.

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, 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 the 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 toward each other as they move downward. In particular, if the item W is a bag body, the bag body deforms under its own weight and comes into contact with the pair of receiving parts 70 over a wider area than in the state shown in FIG. 4.

Then, the suction part 32, which has released the suction, and the receiving member 61 are moved relative to each other in a direction away from each other in the vertical direction Z. That is, the lift cylinder 36 is driven to contract, and only the suction part 32 is raised to the raised position shown in FIG. 4.

As shown in FIG. 1, the robot 20 moves the suction mechanism 30 when 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 when the suction of the suction portion 32 is released and when the pair of receiving members 61 receive the article W from below.

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

As shown in FIG. 2, a first electromagnetic on-off valve 71, a second electromagnetic on-off valve 72, and a first sensor 73 are attached to the mechanism body 31 of the suction mechanism 30 at predetermined locations. 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 open/close cylinder 62 through piping (not shown). The first sensor 73 detects the pressure of the lift cylinder 36.

<Detailed Configuration of 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 at 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.

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 located opposite each other on both sides of the block 45 in the X direction. The center return mechanism 56 is driven to a lock position shown in FIG. 5, which does not allow the suction unit 32 to slide, and a slide allowance position shown in FIG. 6, which allows the suction unit 32 to slide by the slide mechanism 50. When the pair of first cylinders 57 are extended, the tips of the pair of rods 57a clamp the block 45 from both sides in the X direction, locking the tilt fulcrum of the suction unit 32 to the center position so that it cannot slide. When the first cylinder 57 is contracted, the pair of rods 57a retreat in the direction away from each other, and the block 45 is allowed to slide in the X direction and can move freely in the X direction. In other words, the tilt fulcrum of the suction unit 32 is allowed to slide in the X direction and can move freely in the X direction.

At this time, if the suction unit 32 is allowed to tilt, when the suction unit 32 suctions the article W, it tilts in a direction according to the inclination of the suctioned surface of the article W. Therefore, depending on the inclination of the article W, the suction unit 32 tilts from a horizontal position in the counterclockwise direction shown by the solid line in FIG. 6 or in the clockwise direction shown by the two-dot chain line in the same figure. Therefore, even if the article W is tilted, the suction unit 32 can reliably suction the article W by pressing the entire surface of the suction pad 39 against the suctioned surface of the article W. Furthermore, the suction unit 32 can ensure a large tilting angle by sliding the tilting fulcrum in the X direction during the tilting process.

<Detailed Configuration of Lock Mechanism 46>
Next, the configuration of the lock 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.

As shown in Figures 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 Figure 7, when the second cylinders 47 are extended, the 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 holding the restricting plate 49 in a horizontal position. Thus, the suction part 32 is held 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.

Also, as shown in FIG. 8, when the second cylinder 47 is driven to contract, the pressing portion 47a fixed to the tip of each rod moves away from the upper surface of the regulating plate 49, allowing the suction portion 32 to tilt. Therefore, when the article W is tilted, the suction portion 32 is pressed against the tilted suction surface of the article W, and tilts in the direction of the inclination of the suction surface of the article W. Therefore, depending on the inclination of the article W, the suction portion 32 tilts from the horizontal position in the counterclockwise direction shown by the solid line in FIG. 8 or in the clockwise direction shown by the two-dot chain line in the same figure. Therefore, even with a tilted article W, the suction port 39b of the suction pad 39 can be pressed against the entire surface of the suction surface of the article W to suction the article W.

<Electrical Configuration of 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 includes 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.

As shown in FIG. 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 item 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.

The input unit 15 is operated by the worker to input the loading/unloading information required 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, an operation panel or a keyboard and mouse of a personal computer. The loading/unloading information includes item-related information regarding the product number, size, weight, contents, etc. of the item W, and 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) from the suction port 39b of the suction pad 39. Before the suction unit 32 suctions the item W, air flows in from 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 and air does not flow in, so the negative pressure in the suction pad 39 exceeds the threshold. The control unit 100 determines that the suction unit 32 has been able to suction the item 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.

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 a predetermined timing according to a program.

When the control unit 100 detects that the suction unit 32 has adsorbed the item W based on the detection signal from the first sensor 73, it drives the lifting cylinder 36 to contract. This causes the lifting mechanism 35 to lift up the item W that has been adsorbed by the suction unit 32.

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 adsorbed to the suction unit 32.

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.

The first electromagnetic on-off valve 71 has a structure that can put the lift cylinder 36 in a free state (no pressure). Here, the free state is a state in which the piston side chamber and the rod side chamber, which are two chambers divided by the piston in the lift cylinder 36, are connected. The first electromagnetic on-off valve 71 has, for example, a restriction in the middle of the flow path that connects these two chambers. The first electromagnetic on-off valve 71 has a structure that can be switched between a first switching position that drives the lift cylinder 36 to move up and down, and a second switching position that puts the lift cylinder 36 in a free state. In this free state, the suction part 32 descends due to the weight of the member that can be raised and lowered together with the suction part 32. The first electromagnetic on-off valve 71 is switched to the first switching position in the process in which the suction part 32 descends from the raised position to the suction position. The first electromagnetic on-off valve 71 is switched to the second switching position in the process in which the suction part 32 adsorbs the article W from the suction position.

Therefore, the suction unit 32 descends from the raised position to the suction position with the first driving force f1. Furthermore, the suction unit 32 descends with the second driving force f2, which is weaker than the first driving force f1, from the suction position until it adsorbs the article W. The descent speed of the suction unit 32 due to the first driving force f1 is the first speed V1, and the descent speed of the suction unit 32 due to the second driving force f2 is the second speed V2. The second speed V2 is smaller than the first speed V1 (V2<V1). Therefore, when the suction unit 32 in the raised position descends to the suction position, the suction unit 32 descends at high speed with the first driving force f1 and the first speed V1. When the suction unit 32 places the article W on the upper surface of the pair of receiving members 61 in the closed state, the suction unit 32 descends slowly with the second driving force f2 and the second speed V2. The control unit 100 may be composed of a programmable logic controller (hereinafter also referred to as PLC) and a robot controller.

<Operation of First Embodiment>
Next, the operation of the transfer device 10 will be described with reference to Figures 10 to 17. Each process shown in Figures 10 to 17 shows a cycle of transfer work in which the suction mechanism 30 picks up the article W by suction at the pickup position, places the article W at the placement position, and then starts the transfer work of the next article W to be transferred again. In the following, as an example of the transfer work, a disassembly work in which the robot 20 transfers the articles W one by one from the top layer of the group of articles on the pallet P onto the conveyor 12 will be described. The transfer work may be a stacking work.

The worker operates the input unit 15 to provide the transfer device 10 with the necessary loading and unloading information and an instruction to start the transfer operation. 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 moving 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 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 computer 110 in the control unit 100 executes a program to perform the transfer control. Note that some components such as the lock mechanism 46 and the slide mechanism 50 are omitted in Figures 10 to 17.

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.

First, the control unit 100 moves the suction unit 32 toward the loading start position, which is a predetermined height position above the loading position. For example, when the transfer device 10 is in a standby state, the suction unit 32 is moved from the standby position to the loading start position located directly above the item W to be transferred. The suction unit 32 is moved to the loading start position by driving the robot arm 23. Here, the loading 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 adsorb the item W to be loaded.

The control unit 100 puts the suction unit 32 in a state in which it is permitted to tilt and slide. Specifically, the control unit 100 drives the first cylinder 57 from the extended state shown in FIG. 5 to the contracted state shown in FIG. 6, and drives the second cylinder 47 from the extended state shown in FIG. 7 to the contracted 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.

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

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 descent 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 load-taking 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, there are cases in which the suction port 39b of the suction unit 32 is not blocked by the surface to be suctioned, and the item W is not suctioned.

For example, if an item W is tilted and overlaps an adjacent item W, as the suction part 32 descends, the suction part 32 tilts about the tilting fulcrum, but there is still a gap between the tilted item W and the suction part 32, and the item W cannot be adsorbed. When the suction part 32 descends further, the tilting fulcrum of the suction part 32 slides toward the less tilted side of the tilted item W, and the suction part 32 tilts about the tilting fulcrum. The suction part 32 comes into contact with the entire surface of the adsorbed surface of the tilted item W.

In FIG. 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 when the detected pressure (detected negative pressure) of the first sensor 73 exceeds 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 of the article W to be suctioned, the article W is suctioned to the suction unit 32, and the negative pressure inside the suction unit 32 exceeds the threshold value, so that suction is detected.

Next, as shown in FIG. 13, when suction is detected, the control unit 100 raises the suction unit 32 to the load-receiving end position. The item W that has been sucked up to the suction unit 32 is then pulled up. As shown in FIG. 13, when the item W is pulled up, the tilting fulcrum of the suction unit 32 may be shifted from the center position of the sliding range. In this example, the load-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 sucks up and pulls up the item W when the pair of receiving members 61 are in the open state corresponds to an example of the suction process.

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 tilt fulcrum of the suction unit 32 to the center position in the X direction (see FIG. 5). As a result, the tilt 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.

Next, as shown in FIG. 14, the control unit 100 closes the pair of receiving mechanisms 60 from the open state to the closed state. The opening/closing cylinder 62 is extended, so that the pair of receiving mechanisms 60 close from the open state to the closed state.

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. In the process of the suction unit 32 lowering from the raised position to the suction position, the control unit 100 switches the first electromagnetic opening/closing valve 71 to the first switching position. As a result, the suction unit 32 lowers from the raised position to the suction position with the first driving force f1. Furthermore, in the process of the suction unit 32 adsorbing the item W from the suction position, the control unit 100 switches the first electromagnetic opening/closing 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 descends with the second driving force f2, which is weaker than the first driving force f1, from the suction position until it adsorbs the item W. Additionally, while the suction unit 32 is descending, the first sensor 73 detects the pressure inside the lift 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 lift cylinder 36 in a free state, the article W is placed so as to be lightly pressed against the closed receiving members 61 by the second driving force f2.

At this time, the suction portion 32 is locked in a horizontal position, so the item W is placed on the upper surfaces of the pair of receiving members 61 in a substantially horizontal position. For example, if the suction portion 32 is tiltable, the item W may be placed on the upper surfaces of the pair of receiving members 61 in an oblique position if the item W wobbles. However, in this embodiment, the item W can be placed on the upper surfaces of the pair of receiving members 61 in a horizontal position without being wobbled.

Next, as shown in FIG. 16, the control unit 100 raises the suction unit 32. The lift cylinder 36 is driven to contract, so that the suction unit 32 rises from the lowered position to the raised position. At this time, the first electromagnetic opening/closing valve 71 is returned from the second switching position to the first switching position, so that the suction unit 32 rises at a relatively high speed. Note that in this embodiment, after the pair of receiving members 61 are closed by the receiving mechanism 60, the suction unit 32 and the receiving members 61 move relatively in a direction approaching each other in the vertical direction Z, so that the pair of receiving members 61 in the closed state receive the article W. This corresponds to an example of a receiving process.

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

Then, the robot arm 23 drives the suction mechanism 30 to reach the loading position above the conveyor 12 and stop there while remaining 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 are receiving the article W corresponds to an example of a transfer process.

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 low speed, so that the pair of receiving members 61 open at a low speed from the closed state to the open state. As a result, the article W is gradually lowered along the slope of the pair of receiving parts 70 and placed on the conveyor 12. When the pair of receiving members 61 open to an opening angle at which the article W is surely 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 in a stepwise or continuous manner. 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 loading start position where the next article W to be transferred is located.

In this embodiment, the suction unit 32 is driven at a low speed during the process of suctioning the item W and during the process of placing the item 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 item W. This contributes to shortening the cycle time of the transfer work.

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 an adsorption mechanism 30 having an adsorption unit 32 capable of adsorbing an article W, a robot 20 that moves the adsorption mechanism 30 in a moving 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 receives the article W adsorbed and pulled up from below. The adsorption unit 32 adsorbs the article W when the pair of receiving members 61 are in the open state. The robot 20 moves the adsorption mechanism 30 in a state in which the pair of receiving members 61 in the closed state receive 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 contact each other, and the pair of receiving members 61 may be spaced apart from each other at a position where they are relatively moved in the closing direction compared to the open state. In short, the pair of receiving members 61 may be separated from each other or in contact with each other in the closed state as long as the opening degree is small enough to receive the article W compared to the open state. According to this configuration, the suction unit 32 sucks the article W when the pair of receiving members 61 are in the open state, and the robot 20 moves the suction mechanism 30 in a state in which the pair of receiving members 61 in the closed state receive the article W. Since the receiving mechanism 60 has a pair of receiving members 61 configured to be openable and closable via a scissors mechanism, the article W sucked and pulled up by the suction unit 32 can be transported in a state in which it is firmly supported from below by the pair of receiving members 61. For example, it is possible to transport the article W in a state in which it is separated from the suction unit 32 and received by the receiving members 61. In this case, deterioration of the suction unit 32 can be suppressed compared to a configuration in which the article W is transported while being sucked to the suction unit 32 by the suction force when the article W is picked up. In addition, damage and suction marks on the article W caused by the suction force of the suction unit 32 during transportation can be reduced.

Furthermore, in the case of a conventional rotating receiving member having multiple plates, the article W may tilt when it is placed at the destination, but 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 it is placed at the destination. In addition, in the case of a conventional rotating receiving member, when the article W is removed from the suction part 32 and placed on the plate and transported, there is a considerable possibility that the article W may slip on the plate and tilt or fall. Therefore, it is necessary to transport the article W while the article W is being sucked by the suction part 32 and sandwiched between the suction part 32 and the plate. For this reason, the suction part 32 is easily deteriorated. When the suction part 32 deteriorates, it becomes difficult to suck the article W due to air leakage, etc. Therefore, the frequency of replacement of the suction part 32 increases. This leads to inconveniences such as an increase in the parts cost of the suction part 32 and a decrease in production efficiency due to replacement of the suction part 32. In contrast, the suction mechanism 30 of this embodiment can eliminate these inconveniences.

(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. With 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 item W, and the pair of receiving members 61 can be closed after the item W is suctioned and pulled up.

(1-3) The receiving mechanism 60 closes the pair of receiving members 61 after the suction portion 32 has pulled up the item W. With this configuration, the pair of receiving members 61 closes after the suction portion 32 has pulled up the item W, so that the closed pair of receiving members 61 can receive the item W.

(1-4) After closing the pair of receiving members 61, the receiving mechanism 60 moves the suction part 32 and the receiving member 61 relatively in a direction approaching each other in the vertical direction Z, placing the item W on the pair of receiving members 61, and then moves the suction part 32 and the receiving member 61, which have released the suction, relatively in a direction separating them in the vertical direction Z. The robot 20 moves the suction mechanism 30 with the suction part 32 released and the pair of receiving members 61 receiving the item W from below. With this configuration, the item W can be transferred with the suction part 32 released and the receiving member 61 receiving the item W, so that deterioration such as wear of the suction part 32 can be suppressed. This reduces poor suction caused by air leaks from the suction part 32 and the frequency of replacement due to deterioration of the suction part 32.

(1-5) The suction mechanism 30 includes a tilting mechanism 40 that supports the suction part 32 so that it can tilt, and a locking mechanism 46 that can switch the tilting mechanism 40 between an unlocked state that allows the suction part 32 to tilt and a locked state that locks the suction part 32 in a horizontal position. After closing the pair of receiving members 61, with the suction part 32 locked in a horizontal position, the suction part 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 state. With this configuration, the tilting mechanism 40 is locked, so that the item W can be placed on the pair of receiving members 61 while being maintained in 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 tilted from the horizontal, when the item W is placed at the transfer destination, the position or position of the item W is less likely to shift. In other words, the item W can be placed in an appropriate position with an appropriate position and little shifting.

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

(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 in the open state in which the pair of receiving members 61 are open. In the process in which the robot 20 transfers the item W, the pair of receiving members 61 are brought into 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.

(1-8) The article transfer method for adsorbing and transferring the article W includes an adsorption step, a receiving step, and a transport step. In the adsorption step, the adsorption section 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 a closed state, and then the adsorption section 32 and the receiving members 61 move relatively in a direction approaching each other in the vertical direction Z, so that the pair of receiving members 61 in the closed state receive the article W. In the transport step, the robot 20 moves the adsorption mechanism 30 in a state in which 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.

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 in which the blower 28 (see Figure 25) is used 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 the same components as those of the first embodiment, and their description will be omitted, and the following description will focus on the components that are different from those of the first embodiment.

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 the suction mechanism 30 that suctions the item W, and the suction mechanism 30 attached to the tip of the 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 section 32 that can suction the item W. The suction section 32 can suction the item W and release the suction. In this embodiment, the suction method of the suction section 32 is different from that of the first embodiment, and the item W is suctioned by utilizing the suction airflow that flows into the suction section 32. In Figs. 18 to 21, the item W that is suctioned by the suction section 32 and separated from the conveyor 12 is indicated as item W1, and the item W placed on the conveyor 12 is indicated as item W2.

The suction mechanism 30 is connected to a blower 28 (see FIG. 25), which is a negative pressure source for the pneumatic circuit, through a hose 75. Note that the blower 28 is disposed, for example, on the installation table 13 or at a position adjacent to the installation table 13 in FIG. 1.

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

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 each connected to the suction unit 32, ensuring a flow rate that can generate a suction airflow of the strength required for the suction unit 32.

The control unit 100 (see FIG. 1) of the robot 20 controls the suction and release of the article W in the suction unit 32 by controlling the electromagnetic opening/closing valve 85 (see FIG. 25) connected midway through the hose 75. As shown in FIG. 18, the suction mechanism 30 includes a flexible cable 79 including tubes, cables, etc. that transmit air pressure, power, and control signals to the lifting section including the suction unit 32 that is lifted and lowered by the lifting mechanism 35.

In the first embodiment, the suction unit 32 uses a suction method in which the suction unit 32 suctions the item W using the negative pressure generated by the ejector constituting the negative pressure generating unit 38. Therefore, if there is an air leak between the suction unit 32 and the item W, the negative pressure becomes small, and the suction force is likely to decrease. In contrast, in the present embodiment, the suction unit 32 uses a suction airflow generated by the blower 28 as a negative pressure source to suction the item W. In other words, the suction unit 32 suctions the item W using the suction airflow that flows into the suction pad 39 by the suction force of the blower 28. Therefore, even if there is some air leak between the suction unit 32 and the item W, the suction unit 32 can maintain the suction force to suction the item W. Details of the pneumatic circuit using the blower 28 as a negative pressure source will be described later.

As in the first embodiment, the suction mechanism 30 includes a lifting mechanism 35 for raising and lowering the suction portion 32, a tilting mechanism 40 for tilting the suction portion 32, a sliding mechanism 50 for sliding the suction portion 32, and a return mechanism 55 for returning the tilt and sliding displacement of the suction portion 32. In addition, the suction mechanism 30 of this embodiment includes a receiving mechanism 60 like in the first embodiment, but the configuration of the receiving member 61, which is the part of the receiving mechanism 60 that receives the article W, is different from that of the first embodiment.

The lifting mechanism 35, tilting mechanism 40, slide mechanism 50, and return mechanism 55 will be briefly described below with reference to Figures 19 to 22. These configurations are basically the same as those in the first embodiment, so they will only be briefly described. The suction mechanism 30 has a mechanism 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 the support part 34 that constitutes the mechanism body 31. The lifting mechanism 35 has one vertical lifting cylinder 36. The lifting cylinder 36 is 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. The lifting cylinder 36 is driven to extend and retract, thereby lifting and lowering the suction part 32 that is supported in a suspended state by the lifting member 37.

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 be tilted. The tilting mechanism 40 includes a joint mechanism 41 that supports the suction part 32 so that it can be tilted. The joint mechanism 41 is, for example, 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.

The suction part 32 has a swinging member 48 that is connected to the joint mechanism 41 in a state in which it can rotate around the second axis 43. The suction part 32 is supported in a state in which it can tilt around two axes, X and Y, via the swinging member 48 and the joint mechanism 41. In other words, 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.

The slide mechanism 50 is provided between the lifting member 37 and the suction part 32, and supports the suction part 32 so that it can slide horizontally. 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 part 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.

The suction part 32 is therefore supported in a state in which it can tilt around 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 via the joint mechanism 41 by the tilting mechanism 40, and the tilting fulcrum can be slid in the X direction by the sliding mechanism 50.

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. The lower surface of the suction pad 39 has an opening for a suction port 39b surrounded by the pad portion 39a.

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 can be switched between an unlocked state that allows the suction part 32 to be tilted by the tilt mechanism 40, and a locked state that locks the suction part 32 in a horizontal position. The lock mechanism 46 includes a tilt return function that returns the suction part 32 tilted by the tilt mechanism 40 from the tilted position to a horizontal position.

The center return mechanism 56 switches between a locked state in which the suction part 32 is locked in 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. 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 sliding direction X, and a lock function that locks the suction part 32 in the center position so that it cannot slide. In this embodiment, the suction part 32 returned by the return mechanism 55 is locked in the center position in the sliding direction X and in a horizontal position.

<Detailed Configuration of 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 located opposite to each other on both sides in the X direction sandwiching the block 45. The center return mechanism 56 is driven to a lock position shown in FIG. 5, which does not allow the suction unit 32 to slide, and a slide allowable position shown in FIG. 6, which allows the suction unit 32 to slide by the slide mechanism 50. When the pair of first cylinders 57 are driven to extend, the tips of the pair of rods 57a sandwich the block 45 from both sides in the X direction, thereby locking the tilt fulcrum of the suction unit 32 to be unable to slide at the center position. When the first cylinders 57 are driven to contract, the pair of rods 57a are retracted in the direction away from each other, and the block 45 is allowed to slide in the X direction and can move freely in the X direction. In other words, the tilt fulcrum of the suction unit 32 is allowed to slide in the X direction and can move freely in the X direction.

At this time, if the suction unit 32 is allowed to tilt, when the suction unit 32 suctions the article W, it tilts in a direction according to the inclination of the suctioned surface of the article W. Therefore, depending on the inclination of the article W, the suction unit 32 tilts from a horizontal position in the counterclockwise direction shown by the solid line in FIG. 6 or in the clockwise direction shown by the two-dot chain line in the same figure. Therefore, even if the article W is tilted, the suction unit 32 can reliably suction the article W by pressing the entire surface of the suction pad 39 against the suctioned surface of the article W. Furthermore, the suction unit 32 can ensure a large tilting angle by sliding the tilting fulcrum in the X direction during the tilting process.

<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 opposite the restricting plate 49. When the second cylinders 47 are extended, the pressing parts 47a fixed to the tip parts of the respective rods simultaneously press both ends of the restricting plate 49 from above, thereby holding the restricting plate 49 in a horizontal state. Thus, the suction part 32 is held in a horizontal position in a locked state that prevents it from tilting. During the process in which the robot 20 transfers the article W, the suction part 32 is locked in a horizontal position.

When the second cylinder 47 is contracted, 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 object W, it tilts from the horizontal position in accordance with the tilt of the object W. This allows the entire suction port 39b of the suction pad 39 to be pressed against the suction target surface of the tilted object W, thereby adsorbing the object W.

<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 a pair of receiving portions 80 of a pair of receiving members 61 is different from that of the receiving portions 70 of the first embodiment.

The receiving mechanism 60 has a pair of receiving members 61 (only one of the receiving members on the front side is shown in FIG. 18) that receives an 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 operation 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 consisting of a scissors mechanism. The link mechanism 63 may 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 receives from below.

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 the intersection. The second link member 66 forms 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.

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 the article W that has been adsorbed by the suction portion 32 or the article W that has been released from the suction portion 32.

As shown in FIG. 19, the first interval is wider than the short dimension of the item W. As shown in FIG. 21, the second interval is narrower than the short dimension of the item W. When there are multiple sizes of item W, the first interval is wider than the short dimension of a large-sized item W. The second interval is narrower than the short dimension of a small-sized item W.

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

<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 plurality of hook members 81 are arranged at regular intervals in the first direction (X direction) which is the rotation axis direction of the link mechanism 63. The plurality of hook members 81 are attached to a cross member 83 made of a long plate member connected in a state of being stretched between 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 of screw holes 84 each of which is provided at regular intervals in the cross member 83. The hook member 81 is fixed to the cross member 83 by screwing a bolt B inserted through the screw hole of the attachment portion 81A into the set of screw holes 84.

23, the pitch HP of the 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 portion 80 is provided with a spacing change mechanism 82 configured to change the spacing of the hook members 81 in the first direction (X direction). The spacing change mechanism 82 is provided with the above-mentioned mounting portion 81A and multiple sets of screw holes 84 that are provided so that the pitch HP of the hook members 81 can be matched to the pitch RP of the assumed roller 16. By selecting the screw hole 84 to be screwed when fixing the mounting portion 81A of the hook member 81 with the bolt B from among the multiple sets of screw holes 84 arranged in the first direction (X direction), 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 intervals that allow them to be inserted into the gap G between the rollers 16, as shown in FIG. 23.

In addition, the receiving portion 80 having multiple hook members 81 can more reliably receive an item W made of a smaller bag body than the receiving portion 70 having multiple round pipes 70a arranged horizontally to extend in the X direction in the first embodiment.

20, even when the pair of receiving members 61 is in a closed state, the hook members 81 constituting the pair of receiving parts 80 can be inserted below the upper surface of the roller 16 through the gap between the rollers 16 without interfering with the roller 16 of the roller conveyor 12. Therefore, the suction part 32 can close the pair of receiving parts 80 before suctioning and lifting the article W placed on the roller 16. The pair of receiving parts 80 can receive the article W from below while it is still on the roller 16 by the hook members 81. Then, the article W suctioned by the suction part 32 can be lifted after the pair of receiving parts 80 receives it from below. Therefore, even if the article W comes off the suction part 32 due to an air leak or the like while the suction part 32 is lifting the article W, the article W is still in a state of being received from below by the pair of receiving parts 80, so the article W will not fall, or even if it falls, it will only fall a few centimeters before it is received by the pair of receiving parts 80, so the impact of the fall is quite small.

When placing an item W on the roller conveyor 12, the pair of receiving parts 80 in the closed state can receive the item W from below and place the item W on the roller conveyor 12. That is, the multiple hook members 81 constituting the receiving parts 80 are inserted into the gaps between the rollers 16, so that the item 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 item W becomes detached from the suction part 32 during the loading process due to an air leak or the like, the item 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.

<Configuration of pneumatic circuit>
Next, with reference to Fig. 24, a 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 a drive source for a blower 28 that is a negative pressure source. The vacuum pump 29 exhausts air with a fan to generate a suction airflow in the upstream piping. The suction unit 32 is configured to be able to suction the article W with the suction airflow generated by the blower 28 as a negative pressure source.

The vacuum pump 29 is connected to the suction unit 32 by a pipe consisting of a hose 75 (75A, 75B) and the like. An electromagnetic on-off valve 85 and a filter 89 are provided in series in the pipe between the vacuum pump 29 and the suction unit 32. The electromagnetic on-off valve 85 is switched and controlled by the control unit 100 (Fig. 1). When the electromagnetic on-off valve 85 is in the open position shown in Fig. 24 while the vacuum pump 29 is in operation, a suction airflow is generated in the suction unit 32, which flows into the suction port 39b of the suction pad 39. When the electromagnetic on-off valve 85 is in the closed position, no suction airflow is generated in the pipe located upstream of the electromagnetic on-off valve 85 in the flow direction of the suction airflow. Therefore, when the electromagnetic on-off valve 85 is in the closed position, the suction force of the suction unit 32 disappears. The electromagnetic on-off valve 85 may be configured to be switched by an electromagnetic force and an auxiliary force by a pilot pressure as shown in Fig. 24.

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 has 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 by the control unit 100 (FIG. 1). The flow rate adjustment valve 86 adjusts the flow rate of the suction air 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 adsorbed to the suction unit 32 by increasing or decreasing the leak flow rate of air passing through the flow rate adjustment valve 86.

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 opening of the flow rate adjustment valve 86. In detail, the vacuum pump 29 of the blower 28 is driven at a predetermined rotation speed, and this suction force generates a suction airflow toward the blower 28 in the piping consisting of the hoses 75, 75A, and 75B. If the air intake port for this suction airflow is only the suction port 39b of the suction unit 32, a large suction force is generated in the suction unit 32. The suction force of the suction unit 32 decreases due to air leakage, in which air at a flow rate according to the opening of the flow rate adjustment valve 86 is also taken in from the piping via the flow rate adjustment valve 86. In this way, the control unit 100 adjusts the opening of the flow rate adjustment valve 86 to adjust the suction force of the suction unit 32.

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 in which the negative pressure in the suction unit 32 exceeds the negative pressure threshold. When the negative pressure in the suction unit 32 exceeds the negative pressure threshold, the pressure switch 98 switches from off to on. 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 body, which is the article W, to break depending on the strength of the bag body. When the pressure switch 98 is on, the control unit 100 adjusts the opening of the flow rate control valve 86 to a larger side. The opening of the flow rate control valve 86 is adjusted to a larger value to increase the leak flow rate, and the negative pressure acting on the article W adsorbed 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 the suction by the suction unit 32 by switching the electromagnetic opening/closing valve 85 from an open position to a closed position. In addition, silencers 87, 88 (silencers) with sound-absorbing functions 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.

<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 the transfer device 10 is a suction type that uses the blower 28 shown in the pneumatic circuit of Fig. 24 as a negative pressure source.

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 the input unit 15, the camera 91, the first sensor 73, the second sensor 96, the third sensor 97, and the pressure switch 98 as an input system. The first sensor 73 detects that the suction unit 32 has adsorbed the item 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 the pair of receiving members 61 that constitute the receiving mechanism 60, that is, 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 the respective functions.

The pressure switch 98 is turned on and off by the air pressure (negative pressure) in the suction port 39b of the suction pad 39. Before the suction unit 32 suctions the item W, the suction airflow flows in from 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 and no air flows in, so the negative pressure in the suction pad 39 rises. This negative pressure is a value according to the suction force acting on the item W. Therefore, the negative pressure in the suction unit 32 reflects the suction force acting on the item W. The pressure switch 98 is turned off when the detected negative pressure is a small value below the threshold, and is turned on when the detected negative pressure is a large value exceeding 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 from the suction unit 32. The threshold at which the pressure switch 98 is turned on may be changed according to the strength of the item W. For example, if the item W is a second item that is more easily broken than the first item, the second threshold is set to a value smaller than the first threshold set in the pressure switch 98 when the item W is the first item.

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 a predetermined timing according to a program.

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 that uses 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, and so the control content is partially different due to the different configuration from that of the first embodiment. The detailed control content of the control unit 100 will be described later.

<Operation of the Second Embodiment>
Next, the operation of the transfer device 10 will be described with reference to Figs. 26 to 33. Each step shown in Figs. 26 to 33 shows a 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 a 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 position and the roller conveyor 12 at the placement position may be different. In an example of a disassembly operation in which the robot 20 transfers the articles W one by one from the topmost tier of the group of articles on the pallet P onto the roller conveyor 12 as the transfer operation, the placement operation shown below can be adopted. In an example of a stacking operation in which the articles W are loaded onto the pallet P as the transfer operation, the loading operation shown below can be adopted in which the robot 20 loads the articles W on the roller conveyor 12 one by one.

The basic control contents, such as speed control of the lifting cylinder 36, are the same as those in the first embodiment. Below, the loading operation of loading an item W on the roller conveyor 12 using the suction mechanism 30 of this embodiment and the loading operation of loading the attracted item W onto the roller conveyor 12 will be explained. First, the loading operation will be explained with reference to Figures 26 to 30.

First, the control unit 100 drives the robot arm 23 to move the suction unit 32 to the load-taking start position (FIG. 26), which is a predetermined height position above the load-taking position. When the control unit 100 determines that the suction mechanism 30 has reached the load-taking start position, the robot 20 stops the movement of the suction mechanism 30. At this load-taking start position, the pair of receiving parts 80 are in an open state, and the suction force of the suction unit 32 is in a stopped state. The control unit 100 puts the suction unit 32 in a state in which it is permitted to tilt and slide. In detail, 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 permitted to slide in the X direction, and is permitted to tilt about both the first axis 42 (X axis) and the second axis (Y axis).

As shown in FIG. 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.

For example, if an item W is tilted due to overlapping with an adjacent item W, the suction unit 32 that comes into contact with the item W during the descent process tilts while sliding toward the less tilted side of the item W. The suction unit 32 adheres to the item W by abutting the entire surface of the suction target surface of the tilted item W. The control unit 100 detects that the suction unit 32 has adhered to the item W when the detection pressure (detected negative pressure) of the first sensor 73 exceeds a threshold value.

Next, when the control unit 100 detects the suction, it drives the opening and closing cylinder 62 from the contracted state to the extended state while the article W is positioned on the roller conveyor 12. As a result, as shown in FIG. 29, the receiving mechanism 60 is closed from the open state to the closed state, so that the article W can be received from below by the pair of receiving parts 80 while it is placed on the roller conveyor 12. At this time, if the receiving mechanism 60 is closed with the suction parts 32 lowered as shown in FIG. 27, the pair of receiving parts 80 may interfere with the article W. Therefore, while the article W is held in the position on the roller conveyor 12, the suction mechanism 30 may be lowered and the suction parts 32 may be raised at the same speed at the same time to obtain the state shown in FIG. 28. In the state shown in FIG. 28, the suction parts 32 are in a position drawn toward the rotation center side (upper side) of the receiving mechanism 60. When the receiving mechanism 60 is closed from this state, the pair of receiving parts 80 are unlikely to interfere with the article W. At this time, the multiple hook members 81 constituting the pair of receiving parts 80 are inserted into the gap between the rollers 16 as shown in FIG. 20. However, if the receiving mechanism 60 is closed completely in this state, there is a risk that part of the link mechanism 63 will interfere with the roller 16. For this reason, the ascent of the suction mechanism 30, the descent of the suction part 32, and the closing operation of the receiving mechanism 60 may be simultaneously controlled while keeping the insertion depth of the hook member 81 into the roller 16 within a predetermined range, thereby transitioning to the state shown in FIG. 29 while the article W is still on the roller conveyor 12. By appropriately including the above operations, the article W can be received from below while still on the roller conveyor 12, as shown in FIG. 21 and FIG. 29.

Then, as shown in FIG. 30, the article W adsorbed by the suction portion 32 can be lifted up from the roller conveyor 12 with a pair of receiving members 61 receiving the article W from below.
In this way, when the suction unit 32 picks up the 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 the 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.

Next, the loading operation of placing an item W on the roller conveyor 12 will be described with reference to Figures 30 to 33. As shown in Figure 30, the item 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 that cannot be tilted.

After the item W is transferred, the suction mechanism 30 is placed at the loading start position shown in FIG. 30. When starting the loading operation, the control unit 100 may set the suction unit 32 in a state in which it can slide and tilt.

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.

For example, in the first embodiment, in the loading process, the pair of receiving members 61 must be opened before placing the item W on the roller conveyor 12. For this reason, while the pair of receiving members 61 is open, the item W must be slid down onto the placement surface Pa (FIGS. 16 and 17), or the item W adsorbed to the suction portion 32 must be lowered and placed on the roller conveyor 12 while the pair of receiving members 61 is open. In this case, there is a concern that the item W may be subjected to an impact when it slides down, or a drop impact may be applied to the item W when it comes off the suction portion 32 during the descent. In contrast, in this embodiment, the item W can be placed on the roller conveyor 12 while being supported from below by the pair of receiving portions 80, so there is no need to worry about the item W being subjected to an impact.

As shown in FIG. 32, after placing the item 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 portion 80 in the closed state does not interfere with the rollers 16, and the item W can be placed on the roller conveyor 12.

Furthermore, as shown in FIG. 33, the suction part 32 is raised with the suction force stopped. Thus, the loading operation is completed. The receiving mechanism 60 may be opened from the state shown in FIG. 31, but the suction part 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 parts 80 is opened from the position shown in FIG. 31, the end of the article W is resting on the hook member 81, so there is a concern that the article W may be dragged and shifted. Therefore, the pair of receiving parts 80 may be lowered once from the position shown in FIG. 31 before being opened. In this way, the pair of receiving parts 80 opens after the hook member 81 moves downward away from the article W, so there is no concern that the article W will shift due to the opening action of the hook member 81.

In this way, 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 loading position where the hook member 81 is partially inserted between the rollers 16 of the roller conveyor 12. After the suction mechanism 30 is lowered, 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 portions 80. Therefore, the pair of receiving portions 80 can receive the item W from below until the item W is placed at the loading position on the roller conveyor 12.

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

When the transfer device 10 picks up an item W placed on a placement surface Pa other than the roller conveyor 12, and when it places an item W on a placement surface Pa other than the roller conveyor 12, the picking and placing are performed by the same operation and control as in the first embodiment.

Effects of the Second Embodiment
As described above in detail, according to this embodiment, in addition to obtaining the effects (1-1) to (1-8) of the first embodiment, the following effects are also obtained.

(2-1) The suction unit 32 is configured to be able to suction the item W with the 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 item W when it is suctioned by the suction unit 32 by the amount of leakage of the suction airflow. With this configuration, the suction airflow that determines the suction force acting on the item W suctioned by the suction unit 32 can be adjusted according to the strength of the item W. Therefore, it is possible to ensure reliable suction for multiple types of items W with different strengths while avoiding damage to the item W. If the item W is, for example, a bag containing contents, it is possible to avoid the bag from breaking due to excessive suction force.

(2-2) A pressure switch 98 is provided as an example of a detection unit 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 adjusts the negative pressure acting on the item W to a smaller value by increasing the leak flow rate. With this configuration, it is possible to prevent excessive negative pressure from acting on the item W for any reason in a state in which the suction airflow is adjusted so that the negative pressure acting on the suction unit 32 becomes a negative pressure appropriate to the type of item W.

(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 side portion. The spacing change mechanism 82 is configured to be able to change the spacing between the plurality of hook members 81. According to this configuration, the pair of receiving members 61 receive the article W with the plurality of hook members 81, so that the article W can be received more reliably than a receiving member 61 without a hook member 81. In addition, when an article W is loaded on the roller conveyor 12 or when an article W is loaded on the roller conveyor 12, the hook member 81 can be inserted into the gap G between the rollers 16. For example, if the spacing (or pitch HP) of the hook members 81 is changed according to the spacing (or pitch RP) of the rollers 16 of the roller conveyor 12, the hook member 81 can be partially inserted into the gap G between the rollers 16. Therefore, an item W can be placed on the roller conveyor 12 while the pair of receiving members 61 is in a closed state, and the adsorbed item W can be picked up after the pair of receiving members 61 is closed.

(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 it is placed. Therefore, even if the item W comes off the suction portion 32 when it is placed, the impact of a fall on the item W can be avoided or suppressed.

(2-5) When the suction unit 32 picks up an item 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 item 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 item 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. With this configuration, the item 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.

The embodiment is not limited to the above and may be modified as follows.
In the above embodiment, the driving unit for opening and closing the pair of receiving members 61 may be omitted. Even without the opening and closing cylinder 62, which is an example of a driving unit, the pair of receiving members 61 can be opened and closed by utilizing their own weight or the reaction force received from the article W. For example, the suction mechanism 30 shown in Figs. 34 to 37 does not include the opening and closing cylinder 62, which is an example of a driving unit. In this case, as shown in Fig. 34, when the lower ends of the pair of receiving members 61 hit 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 the lower ends of each of them sandwich the article W (two-dot chain line in Fig. 35). From this state, the lifting cylinder 36 is extended, and the suction part 32 is lowered to suction the article W. Next, as shown in Fig. 36, the robot arm 23 raises the suction mechanism 30 to a predetermined height, and the pair of receiving members 61 close due to their own weight. Furthermore, the suction unit 32 descends at the second speed V2 (low speed), so that the article W is placed on the upper surface of the pair of receiving members 61. Then, the load of the article W is also applied to the pair of receiving members 61, so that the force acting in the closing direction on the pair of receiving members 61 becomes large. Therefore, in the process in which the robot arm 23 transfers 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, in the loading position, the robot arm 23 descends the suction mechanism 30 at a low speed, so that the pair of receiving members 61 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 slope of the pair of receiving parts 70 and is placed on the conveyor 12. After that, 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 is not provided with a driving unit such as the opening/closing cylinder 62, the pair of receiving members 61 can be opened and closed by using their own weight and reaction force. Therefore, according to this transfer device, by eliminating drive parts such as the opening/closing cylinder 62, it is possible to reduce the number of drive system parts and reduce the control load of the control unit 100.

The configuration for relatively moving the suction part 32 and the receiving member 61 in a direction toward or away from each other in the vertical direction Z may be a configuration in which the receiving member 61 rises and falls, instead of a configuration in which the suction part 32 rises and falls. Furthermore, the configuration may be such that both the suction part 32 and the receiving member 61 move in a direction toward each other or in a direction away from each other.

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

In the second embodiment, a spacing change mechanism 82 may be provided that can change the spacing (or pitch HP) between the multiple hook members 81 using the power of a drive source. Examples of the power source include a pneumatic cylinder or a motor.

- The suction unit 32 may suction the item W while the moving mechanism such as the robot 20 is transporting the item W. For example, if the suction force is weaker than that at the time of picking up or placing the item, damage or suction marks caused by the suction force on the item W can be reduced. For example, the item W may be sandwiched between the suction unit 32 and a pair of receiving members 61. When the item W is sandwiched between the suction unit 32 and a pair of receiving members 61, the suction of the suction unit 32 may be released. Also, 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 at the time of picking up or placing the item.

- 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, it may be performed after the lifting mechanism 35 starts to pull up the adsorbed article W from above the roller conveyor 12, when the suction mechanism 30 is in the loading position, or after the suction mechanism 30 starts to rise from the loading position. Note that the closing operation is preferably performed when the article W is on the roller conveyor 12, or while the article W is within 5 cm from above the roller conveyor 12.

- 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 pumps gas by the rotational motion of an impeller or rotor or the reciprocating motion of a piston, and has an effective discharge pressure of 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, a screw pump, etc. Also, the blower 28 in this specification may be a fan (air blower). Note that 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.

- 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 capable of opening and closing 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 pivot axis are fixed to the tip of each rod in a double-rod type cylinder.

- In the above embodiment, the sliding mechanism 50 allows the suction portion 32 to slide only in the longitudinal direction (X direction) of the article W, but the sliding mechanism 50 may allow the suction portion 32 to slide only in the lateral direction (Y direction) of the article W. The sliding mechanism 50 may also allow the suction portion 32 to slide in two directions, the X direction and the Y direction. In these cases, a center return mechanism may also be provided in the Y direction.

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 portion 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 portion 32. The suction portion 32 can tilt against the biasing force of the springs, and can return to the horizontal position by the biasing force of the springs.

A return spring may be provided instead of the center return mechanism 56. The biasing force of the return spring returns the tilt fulcrum of the attraction portion 32 to a reference position (for example, a center position) in the sliding direction.
The slide mechanism 50 slides in the horizontal direction. However, if the suction portion 32 is tilted, the slide mechanism 50 may slide the suction portion 32 along the tilt direction.

The slide shaft that constitutes 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.

The drive unit may be a motor instead of the opening/closing cylinder 62 .
The slide mechanism 50 need not be provided.
The lock mechanism 46 may not be provided.

The tilt mechanism 40 need 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 in this configuration, it is possible to suppress a decrease in the durability of the suction plate caused by suctioning the object W during the transfer process, and to suppress damage to the object W and the leaving of suction marks due to the suction force.

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

The object W is not limited to a bag, but may be a case such as a box. The shape of the object other than the bag is not limited to a rectangular parallelepiped, but may be another polygonal prism (for example, a triangular prism or a hexagonal prism) or a cylindrical shape.
The suction mechanism 30 may be configured to have multiple suction pads 39 and to adsorb multiple articles W at a time, or multiple suction pads 39 may adsorb one article W.

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

The moving mechanism is not limited to the robot 20. For example, it may be a moving mechanism having an X-moving mechanism, a Y-moving mechanism, and a Z-moving mechanism, which moves the suction mechanism 30 in the X-, Y-, and Z-directions. The moving mechanism may be a Z-moving mechanism that moves only in the height direction Z (lifting direction). Furthermore, if the suction mechanism 30 is configured to include a lifting mechanism 35, the moving mechanism may be an X-moving mechanism that moves only in the X-direction, or a Y-moving mechanism that moves only in the Y-direction. It may also be a moving mechanism that moves in only two of the XYZ directions. Note that if the configuration includes only an X-moving mechanism or a Y-moving mechanism, the lifting mechanism 35 forms part of the moving mechanism.

- In the first and second embodiments, the operation of lowering the suction part 32 to load the item W may be performed by the robot arm 23 lowering the suction mechanism 30, rather than by the extension drive of 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 item W may be performed by the robot arm 23 lowering the suction mechanism 30, rather than by the extension drive of the lifting cylinder 36 that constitutes the lifting mechanism 35.

- The suction mechanism 30 may be configured without the lifting mechanism 35. In this case, a movement mechanism such as the robot 20 may move the suction part 32 in the lifting and lowering direction.

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-23C...arm section, 24...driving mechanism, 25...power source, 26...motor, 27...rotating section, 28...blower, 29...vacuum pump, 30...suction mechanism, 31...mechanism 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, 8 9...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) which is an example of the first direction, Y...Y direction, Z...height direction (vertical direction).

Claims (13)

An article transfer device that adsorbs and transfers an article,
A suction mechanism having a suction portion capable of suctioning the article;
a moving mechanism that moves the suction mechanism in a moving direction including a lifting direction;
Equipped with
the suction mechanism includes a receiving mechanism having a pair of receiving members configured to be openable and closable via a scissors mechanism between an open state in which the suction portion opens to a position that does not interfere with a suction operation of suctioning the article, and a closed state in which the suction portion receives the article that has been sucked up by the suction portion from below,
The suction portion suctions the article when the pair of receiving members are in an open state,
The article transfer device, wherein the moving mechanism moves the suction mechanism when the pair of receiving members in the closed state receive the articles. The article transfer device according to claim 1, characterized in that the receiving mechanism includes a drive unit that opens and closes the pair of receiving members. The article transfer device according to claim 1, characterized in that the receiving mechanism closes the pair of receiving members after the suction part lifts up the article. The receiving mechanism closes the pair of receiving members, and then moves the suction portion and the receiving member relatively in a direction approaching each other in a vertical direction to place the article on the pair of receiving members, and then moves the suction portion and the receiving member, which have released the suction, relatively 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 in a state in which the suction of the suction portion is released and the pair of receiving members receive the article from below. 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 the suction unit to tilt 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 relatively toward 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. In the process of a suction operation for 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 to be placed on the pair of receiving members in the closed state, the suction portion is lowered by the second driving force. 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 adjustment section capable of adjusting a negative pressure acting on the article when it is sucked by the suction section by a leakage flow rate of the suction airflow. a detection unit capable of detecting an excessive negative pressure in which the negative pressure acting on the adsorption 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 detection unit detects the excessive negative pressure. The pair of receiving members each have a plurality of hook members arranged at intervals in a first direction at a tip end portion,
2. The article transfer device according to claim 1, further comprising a distance changing mechanism configured to change the distance between the plurality of hook members. 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 the 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, further comprising: 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;
Do the following:
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. The adsorption mechanism according to any one of claims 1 to 11,
a mounting portion that can be mounted on an arm of a multi-joint robot serving as the moving mechanism;
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 that has been sucked up by the suction portion from below,
The suction portion suctions the article when the pair of receiving members are in an open state,
A suction mechanism characterized in that, during the process of the articulated robot transferring the article, the pair of receiving members are put into the closed state in which they receive the article from below. An article transfer method for adsorbing and transferring an article, comprising the steps of:
A suction mechanism having a suction portion capable of suctioning the article;
a moving mechanism that moves the suction mechanism in a moving direction including a lifting direction;
Equipped with
the suction mechanism includes a receiving mechanism having a pair of receiving members configured to be openable and closable via a scissors mechanism between an open state in which the suction portion opens to a position that does not interfere with a suction operation of suctioning the article, and a closed state in which the suction portion receives the article that has been sucked up by the suction portion from below,
a suction step in which the suction portion suctions and lifts the article while the pair of receiving members are in an open state;
a receiving step in which, after the pair of receiving members are closed to the closed state by the receiving mechanism, the suction portion and the receiving members move relatively in a direction approaching each other in a vertical direction, so that the pair of receiving members in the closed state receive the article;
a transport step in which the moving mechanism moves the suction mechanism while the pair of receiving members in the closed state receive the articles.

Images