Conveying system

Abstract

To solve the problem that an article to be conveyed cannot be smoothly installed on an installation surface by pushing out the article to be conveyed and smoothly sliding the bottom surface of the article to be conveyed on the installation surface due to uneven frictional force between the article to be conveyed and the installation surface.SOLUTION: The conveyance system 1 includes a carriage 2 and a picking apparatus 3. The picking device 3 includes a placement table 20 on which the conveyance object P is placed, a suction mechanism 50 having a pad 52 that the surface of the conveyance object P by air suction, and a moving mechanism 40 having a pad lifting mechanism 41 and a pad linear motion mechanism 42, wherein the suction mechanism 50 is a mechanism that causes the pad 52 to be sucked to a side surface Ps of the conveyance object P at a conveyance start point and causes the pad 52 to be sucked to a top surface Pc of the conveyance object P placed on the placement table 20 at a conveyance destination.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a transport system for transporting an article. [Background technology]

[0002] For example, one such technology is a robot hand (transport system) that transports an item. In this technology, the transport system includes an adsorption unit that adheres to the side of the item and moves in a first direction, and a drive belt that moves a transport surface on which the item is placed. The adsorption unit moves in the first direction to place the adsorbed item on the transport surface, and the adsorption unit is fixed to the drive belt so as to move together with the transport surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7289916 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conveyance system of Patent Document 1, when the transported product reaches its destination and is to be placed, an adsorption unit that sucks the side of the transported product pushes the transported product out and delivers the transported product from the robot hand to the placement surface. However, due to uneven friction between the transported product and the placement surface, it may not be possible to smoothly slide the bottom surface of the transported product onto the placement surface by pushing out the transported product, and to smoothly place the transported product on the placement surface.

[0005] The present invention has been made in consideration of the above points, and aims to provide a transport system that can smoothly place a transported item on a placement surface from a cart that has reached its destination. [Means for solving the problem]

[0006] In view of the above problem, the transport system of the present invention is a transport system for transported items, comprising: a cart that travels independently along a route from the transport start point to the transport destination point of the transported item; and a picking device that is attached to the cart, pulls in the transported item at the transport start point, and delivers the transported item at the transport destination point, wherein the picking device comprises a loading platform on which the transported item is placed, a suction mechanism having a pad that adsorbs the surface of the transported item by air suction, a pad lifting mechanism that raises and lowers the pad, and a pad linear motion mechanism that moves the pad horizontally in the retracting direction and the delivering direction, and is characterized in that the suction mechanism is a mechanism that adsorbs the pad to the side of the transported item at the transport start point, and adsorbs the pad to the top surface of the transported item placed on the loading platform at the transport destination point.

[0007] According to the present invention, at the start point of transport, the pad is moved horizontally using the pad linear motion mechanism, thereby contacting the pad with the side of the transported product. Next, the suction mechanism is used to adsorb the pad to the side of the transported product by air suction. The pad, with the side of the transported product adsorbed, is moved horizontally to the mounting table using the pad linear motion mechanism, thereby enabling the transported product to be quickly placed on the mounting table. Furthermore, at the destination point of transport, the pad is brought into contact with the top surface of the transported product placed on the mounting table using the pad lifting mechanism and the pad linear motion mechanism, and the suction mechanism is used to adsorb the pad to the top surface of the transported product by air suction. Next, the pad is moved by the pad lifting mechanism so as to lift the transported product with the pad adsorbed to the top surface, and the pad linear motion mechanism is used to move the pad horizontally to the placement surface of the transported product so as to remove the lifted transported product from the placement table. Finally, the pad lifting mechanism can lower the pad until the transported product contacts the placement surface. This allows the transported product to be smoothly placed on the placement surface without sliding relative to the placement surface. In particular, when the pad is an elastically deformable material such as a bellows, variations in the frictional force between the bottom surface of the transported product and the placement surface can easily cause the pad to elastically deform locally, resulting in misalignment. However, according to the present invention, the transported product can be placed on the placement surface without sliding, so that the transported product can be placed on the placement surface with high accuracy from the cart that has reached its destination.

[0008] Here, when the height of the placement surface on which the transported item is placed and the height of the installation surface on which the transported item is placed are approximately the same height, the height of the placement table is the same, so the placement table may be fixed to the picking device without being raised or lowered. However, in a more preferred embodiment, the moving mechanism further has a table raising and lowering mechanism for raising and lowering the placement table.

[0009] According to this aspect, by using the platform lifting mechanism, even if the height of the placement surface for the transported product and the height of the installation surface are different, the platform can be raised and lowered according to the height of the placement surface for the transported product at the transport start point and the height of the installation surface for the transported product at the transport destination point. This allows the transported product to be smoothly drawn onto the platform, and then ejected from the platform, and quickly installed on the installation surface.

[0010] Here, the structures of the pad and suction mechanism are not particularly limited as long as the pad can selectively suction the side and top surface of the transported product. In a more preferred first aspect, the pad has a side pad that suctions the side surface of the transported product, and a top pad that suctions the top surface of the transported product placed on the stage at the transport destination point.

[0011] According to this first aspect, when adsorbing the side pads and the top pad, it is only necessary to switch the air suction using a valve, solenoid valve, etc., so that adsorption of the side pads and adsorption of the top pads can be switched easily and quickly.

[0012] In a more preferred second aspect, the suction mechanism further includes a swinging mechanism that swings the pad so as to change the suction direction of the pad between a direction facing the side surface of the transported product and a direction facing the top surface of the transported product. According to this second aspect, swinging the pad by the swinging mechanism allows one pad to perform the functions of suctioning both the side surface of the transported product and the top surface of the transported product.

[0013] The above-described series of operations may be performed manually by an operator, but more preferably, the conveying system further includes a control device that controls the movement of the pad by the moving mechanism, and the control device controls the pad linear motion mechanism so that, at the start of the conveying, the conveyed item is pulled horizontally up to the placement table with the pad adsorbed to the side, and at the destination of the conveying, the control device controls the pad lifting mechanism so that the conveyed item placed on the placement table is lifted with the pad adsorbed to the top surface, and then controls the pad linear motion mechanism so that the conveyed item is horizontally ejected from the placement table to above the placement surface of the conveyed item, and controls the pad lifting mechanism so that the pad descends until the conveyed item contacts the placement surface.

[0014] According to this aspect, through a series of controls, at the start of the transfer, with the pads attached to the sides of the transported item, the bottom of the transported item can be quickly retracted onto the loading surface while sliding from the placement surface of a shelf, pallet, or the like to the loading surface of the loading table. Furthermore, at the destination of the transfer, the transported item placed on the loading table can be lifted and then horizontally removed from the loading table to above the loading surface of the transported item. This allows the transported item to be placed on the loading surface without sliding relative to the loading surface, thereby avoiding positional deviation due to friction between the transported item and the loading surface, and the transported item can be accurately placed on the loading surface from the loading table of the transport system that has arrived at the destination of the transfer.

[0015] Furthermore, in a preferred embodiment, the moving mechanism further includes a platform lifting mechanism for raising and lowering the platform, and the control device further controls the raising and lowering of the platform by the platform lifting mechanism, and the control device controls the platform lifting mechanism so that, at the start of the transport, before the transported item is pulled in, the height of the loading surface of the platform is the same as the height of the placement surface of the transported item, and controls the platform lifting mechanism so that, at the destination of the transport, before the transported item is unloaded, the height of the loading surface of the platform is the same as the height of the installation surface of the transported item.

[0016] According to this aspect, the height of the loading surface of the loading platform is adjusted to the same height as the placement surface of the transported item before the transported item is drawn in, allowing the transported item to be drawn in smoothly and quickly.Furthermore, the height of the loading surface of the loading platform is adjusted to the same height as the placement surface of the transported item before the transported item is delivered, allowing the transported item to be delivered smoothly and quickly with a small range of movement. [Effects of the Invention]

[0017] According to the present invention, the transported item can be placed on the placement surface with high accuracy from the carriage that has reached the transport destination. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic perspective view of a transport system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram of the transport system shown in FIG. [Figure 3] FIG. 3 is a block diagram of the control device shown in FIG. 2. [Figure 4] 4 is a control flow diagram of the control device shown in FIG. 3 for pulling in the transported article. [Figure 5] 10(a) to 10(d) are diagrams for explaining the operation of pulling in the transported article. [Figure 6] 4 is a control flow diagram of delivery of the transported item by the control device shown in FIG. 3. [Figure 7] 10(a) to 10(d) are diagrams for explaining the operation of dispensing the transported item. [Figure 8] 7(a) to 7(c) are diagrams illustrating the operation of dispensing the transported item, following FIG. 7(d). [Figure 9] 10(a) and 10(b) are side views of a transport system according to a modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] A transport system 1 according to an embodiment of the present invention will be described below with reference to FIGS.

[0020] 1. About Transport System 1 The conveying system 1 of this embodiment is a system that pulls in (takes in) a transported item P placed on a placement surface TA of a shelf C, pallet D, or lower-level item (transported item) at the start point of the transport, transports the taken-in transported item P, and at the destination point of the transport, removes the transported item P and places it on a setting surface TB of a frame-shaped shelf C, pallet D, or lower-level item (transported item) (see Figures 5, 8, etc.).

[0021] In the following description, the surface on which the transported product P is placed at the transport placement point will be referred to as the placement surface TA, and the surface on which the transported product P is placed at the transport destination point will be referred to as the placement surface TB. The placement surface TA and the placement surface TB are planes with which the bottom surface of the transported product P comes into contact, and are not limited to continuous planes but also include intermittent planes such as the surface of a pallet.

[0022] Furthermore, the transported item P is a rectangular packing box (e.g., a cardboard box) containing parts such as mechanical components, but the shape of the transported item P is not particularly limited as long as the side surface Ps and top surface Pc of the transported item P, which will be described later, can be adsorbed by the pad 52, which will be described later.

[0023] In this embodiment, as shown in FIG. 1, the conveying system 1 includes at least a cart 2 that travels autonomously along a route from the start point of conveyance of the item P to the destination point of conveyance, and a picking device 3 that is attached to the cart 2 and pulls in the item P at the start point of conveyance and delivers the item P at the destination point of conveyance.

[0024] 2. About Cart 2 The cart 2 is equipped with a picking device 3 and is a device that transports the transported item P together with the picking device 3. As shown in FIG. 1, the cart 2 is capable of moving not only in two orthogonal directions LA and LB on the floor surface but also in all directions, and is even capable of rotating in a rotational direction T without substantially moving on the floor surface. Such a cart 2 is a so-called self-supporting transport cart, and its drive mechanism and the like are of a general structure, so detailed description thereof will be omitted.

[0025] Although not shown in Fig. 1, the conveyance system 1 is equipped with a control device 70 (see Fig. 2). The control device 70 stores a map of areas within a factory or warehouse where the cart 2 can travel, and receives, for example, wireless signals from an external management computer to input the start point, destination point, and information about the product P (size, placement position, installation position, etc.), and the cart 2 sets an optimal travel route from the start point to the destination point, and travels under automatic travel control. By controlling the cart 2 to rotate, the orientation of the cart 2 is also controlled to match the placement position and installation position of the product P.

[0026] In this embodiment, the start point and the destination point of the transfer may be different points, or they may coincide. For example, when the carriage 2 is not driven and the transfer item P is transferred in the vertical direction of the same shelf C, or when the carriage 2 of the transfer system 1 is turned and placed on a shelf C in a different direction, the start point of the transfer and the destination point of the transfer coincide.

[0027] 3. About picking device 3 The picking device 3 is mounted on the cart 2 and includes at least a platform 20 on which the transported item P is placed, a suction mechanism 50 that adsorbs the transported item P by air suction, and a movement mechanism 40 that moves a part (a pad 52 described later) of the suction mechanism 50. Although not shown in Fig. 1, the picking device 3 further includes an imaging device 8 that images the transported item P (see Fig. 2).

[0028] 3-1. About the mounting table 20 The mounting table 20 is a flat member, and its leading edge is tapered. The mounting table 20 has a flat mounting surface on which the transported product P is placed. The mounting table 20 is cantilevered by a carriage 45d of a platform lifting mechanism 45 (described later), and is movable in the vertical direction (Z-axis direction).

[0029] 3-2. About the suction mechanism 50 The suction mechanism 50 has a pad 52 that suctions the surface (specifically, the side surface Ps and the top surface Pc) of the transported product P by air suction. The pad 52 has a bellows-like shape that can be expanded and contracted, and its tip end surface, which has an opening formed therein, serves as the suction surface. While the pad 52 is bellows-like in this embodiment, the pad 52 is not limited to this shape and may be, for example, sponge-like, as long as stable suction can be achieved by the pad 52. Furthermore, a force sensor 59 that detects contact of the tip end surface of the pad 52 is provided on the base end side of the pad 52 (see, for example, FIG. 2). The force sensor 59 detects the force (or contact pressure) of the pad 52 contacting the surface of the transported product P, and can determine that the pad 52 has contacted the transported product P when the detected force (or pressure) exceeds a preset value. The force sensor 59 can be, for example, a general sensor using a piezoelectric element, a strain gauge, or the like.

[0030] The suction mechanism 50 is a mechanism that suctions the pad 52 to the side surface Ps of the transported product P at the transport start point (see, for example, FIG. 5(d) described later), and suctions the pad 52 to the top surface Pc of the transported product P placed on the mounting table 20 at the transport destination point (see, for example, FIG. 7(c) described later). In this embodiment, the pad 52 has a side pad 52A that suctions the side surface Ps of the transported product P, and a top surface pad 52B that suctions the top surface Pc of the transported product P placed on the mounting table 20 at the transport destination point, and these are attached to the arm 51.

[0031] Specifically, in this embodiment, a plurality of (e.g., three) side surface pads 52A are arranged at intervals along the horizontal direction on the tip surface of arm 51, and each side surface pad 52A is arranged so that the suction direction is horizontal. A plurality of (e.g., six in 3 x 2 rows) top surface pads 52B are arranged at intervals on the underside of the tip side of arm 51, and each top surface pad 52B is arranged so that the suction direction is vertically downward. There is no limit to the number of side surface pads 52A and top surface pads 52B as long as they can adsorb and move the transported item.

[0032] The side pads 52A and the top pads 52B are connected to a suction pump 54 via a pressure adjustment valve 55 and a switching valve (electromagnetic three-way valve) 56. This allows the air sucked by the suction pump 54 to selectively generate negative pressure inside the side pads 52A and the top pads 52B that are in contact with the transported item P by switching the switching valve 56, thereby allowing the side pads 52A and the top pads 52B to be adsorbed to the transported item P.

[0033] The pressure at this time is adjusted by pressure adjustment valve 55, and the generated suction pressure (negative pressure) is detected by pressure gauge 58. The pressure signal detected by pressure gauge 58 is sent to control device 70. A relief valve 57 that connects the inside of pad 52 to the atmosphere is provided in a pipe branching off from the pipe upstream of suction pump 54 from switching valve 56. When releasing the suction of side pad 52A and top pad 52B, a control signal from control device 70 stops suction pump 54 and opens relief valve 57. As a result, air flows into pad 52 through relief valve 57, and the negative pressure inside pad 52 is released to atmospheric pressure.

[0034] 3-3. About the moving mechanism 40 The moving mechanism 40 is a mechanism that moves the pad 52 and the transported item P (described later) along the X-axis, Y-axis, and Z-axis. As shown in FIG. 1 and other figures, the X-axis, Y-axis, and Z-axis are mutually orthogonal. The X-axis is an axis along the direction in which the transported item P is drawn in and discharged from the carriage 2. The Y-axis is an axis along the horizontal direction orthogonal to the X-axis. The Z-axis is an axis along the up-down direction, i.e., the direction in which the transported item P is raised and lowered. The moving mechanism 40 will be described below with reference to FIGS. 1 and 2.

[0035] Specifically, the moving mechanism 40 has a pad lifting mechanism 41 that raises and lowers the pad 52 in the vertical direction (i.e., the Z-axis direction), and a pad linear motion mechanism 42 that moves the pad 52 horizontally in the retracting direction and the dispensing direction (i.e., the X-axis direction).

[0036] The pad lifting mechanism 41 is a mechanism that drives a pad lifting motor 41a to lift and lower the pad 52 in the Z-axis direction. The pad lifting mechanism 41 is a linear guide mechanism that includes a shaft 41b connected to the pad lifting motor 41a and having a threaded circumferential surface, and a pair of guide rails 41c arranged in parallel with the shaft 41b. The shaft 41b and the guide rails 41c extend in the Z-axis direction, and the shaft 41b rotates around the Z-axis. These components are attached while being accommodated in a housing 48. The pad lifting mechanism 41 further includes a carriage 41d, which is screwed onto the shaft 41b and moves along the guide rails 41c. The pad 52 is indirectly attached to the carriage 41d via an arm 51 or the like.

[0037] When raising and lowering the pad 52, the pad lifting motor 41a is driven by a control signal from the control device 70 to rotate the shaft 41b around the Z axis. This allows the carriage 41d, which is threadedly attached to the shaft 41b, to move together with the pad 52 in the vertical direction (Z axis direction) along the guide rail 41c.

[0038] The pad linear motion mechanism 42 is a mechanism that drives a pad linear motion motor 42a to move the pad 52 horizontally along the X-axis direction. The pad linear motion mechanism 42 is a linear guide mechanism similar to the pad lifting mechanism 41. The pad linear motion mechanism 42 includes a shaft 42b extending along the X-axis direction and a pair of guide rails 42c within a casing 42f. The shaft 42b is connected to the pad linear motion motor 42a via a power transmission belt or the like. The pad linear motion mechanism 42 further includes a carriage 42d, which is screwed onto the shaft 42b and slidably connected to the pair of guide rails 42c. The casing 42f is fixed to the carriage 41d of the pad lifting mechanism 41.

[0039] When the pad 52 is moved linearly along the X-axis direction, the pad linear motor 42a is driven by a control signal from the control device 70 to rotate the shaft 42b around the X-axis. This allows the carriage 42d, which is threadedly attached to the shaft 42b, to move together with the pad 52 in the horizontal direction (X-axis direction) along the guide rail 42c.

[0040] The movement mechanism 40 further includes a pad linear motion mechanism 43 that moves the pad 52 in the Y-axis direction, a rotation mechanism 44 that rotates the pad 52 around the Z-axis, and a platform lifting mechanism 45 that raises and lowers the mounting table 20. The rotation mechanism 44 is fixed to the carriage 42d and includes a rotation motor 44a that rotates the arm 51 together with the pad 52 around the Z-axis. The pad linear motion mechanism 43 is connected to the output shaft of the rotation motor 44a and linearly moves the arm 51 together with the pad 52 in the Y-axis direction. The pad linear motion mechanism 43 is a linear guide mechanism similar to the pad linear motion mechanism 42 and includes a shaft 43b, etc., and the arm 51 is fixed to the carriage 43d. In this way, the pad 52 is movable in the X-axis, Y-axis, and Z-axis directions and is also rotatable around the Z-axis.

[0041] The platform lifting mechanism 45 is a mechanism that drives a platform lifting motor 45a to raise and lower the mounting platform 20 in the Z-axis direction. The platform lifting mechanism 45 is a linear guide mechanism that is arranged alongside the pad lifting mechanism 41 in the Y-axis direction within a housing 48. The platform lifting mechanism 45 includes a shaft 45b that extends along the Z-axis direction and a pair of guide rails 45c. The platform lifting mechanism 45 further includes a carriage 45d that is screwed onto the shaft 45b and slidably connected to the pair of guide rails 45c. The mounting platform 20 is fixed to the carriage 45d of the platform lifting mechanism 45.

[0042] When the pad 52 is moved linearly along the X-axis direction, the pad linear motor 42a is driven by a control signal from the control device 70 to rotate the shaft 42b around the X-axis. This allows the carriage 42d threadedly attached to the shaft 42b to move horizontally (in the X-axis direction) along the guide rail 42c.

[0043] When raising or lowering the mounting table 20, the control device 70 drives the mounting table lifting motor 45a to rotate the shaft 45b around the Z axis. This allows the carriage 45d, which is threadedly attached to the shaft 45b, to move up and down (in the Z axis direction) along the guide rail 45c together with the mounting table 20. In this way, the pad 52 and the mounting table 20 can be raised and lowered independently by the pad lifting mechanism 41 and the mounting table lifting mechanism 45.

[0044] 4. Control Device 70 The control device 70 will be described below with reference to FIGS. 3 to 8. The control device 70 controls the movement of the pad 52 and the mounting table 20 by the moving mechanism 40, and in this embodiment, also controls the automatic travel of the cart 2. The control device 70 includes, as hardware, a storage device and a calculation device, both of which are not shown. The storage device stores a travel map of the warehouse or factory where the cart will travel, an operation program for operating the moving mechanism 40 and the suction mechanism 50, and the like, and the calculation device calculates a travel route from the travel map and makes calculations such as determining whether to run the operation program.

[0045] Specifically, as shown in FIG. 3, the control device 70 includes, as software, a cart driving control unit 71, a transported product detection unit 72, a pad lifting / lowering control unit 73, a pad movement control unit 74, a platform lifting / lowering control unit 75, and a suction control unit 76, which will be described together with the control flow below.

[0046] 4-1. Control flow for retracting transported item P 1 to 3, and further with reference to FIGS. 4 and 5, the retraction control by the control device 70 will be described below. As shown in FIG. 4, in step S401, travel control of the carriage 2 of the conveyance system 1 is performed, and the carriage 2 is moved to the conveyance start point where the transported product P is placed (see FIG. 5(a)). At the conveyance start position, the conveyance product P is placed on a pallet D arranged on a shelf C. Specifically, as shown in FIG. 3, the carriage travel control unit 71 sets a conveyance route of the carriage 2 to the conveyance start point based on the conveyance start point and information on the conveyance product P (specifically, the size of the conveyance product P, the height H1 of the placement surface, etc.) input from the input device 7, and the position information of the carriage 2, etc., and controls the drive device (not shown) of the carriage 2, etc.

[0047] Next, in step S402, upon receiving a detection signal from the carriage travel control unit 71 indicating that the carriage has reached the transfer start point, the transfer item detection unit 72 uses the imaging device 8 to detect the position of the transfer item P at the transfer start point.

[0048] Next, in step S403, as shown in FIG. 5B, the control device 70 raises and lowers the side pad 52A and the mounting table 20 according to the height of the placement surface TA of the transported item P. In this example, the placement surface TA corresponds to the upper surface of the lower stacked item. Specifically, the pad lift control unit 73 controls the pad lift motor 41a of the pad lift mechanism 41 so that the Z-axis position of the side pad 52A is at the center height of the side surface Ps of the transported item P, in accordance with the detected height H1 of the placement surface TA of the transported item P. Furthermore, the pad movement control unit 74 controls the pad linear motion motor 43a of the pad linear motion mechanism 43 so that the Y-axis position of the side pad 52A is at a position where it contacts the side surface Ps of the transported item P, as viewed from the X-axis direction. Furthermore, the platform lift control unit 75 controls the platform lift motor 45a of the platform lift mechanism 45 so that the height H2 of the placement surface 21 of the mounting table 20 is the same height as the height H1 of the placement surface TA of the transported item P. These motors are controlled based on detection signals from encoders attached to the respective motors 41a, 43a, and 45a so that the top surface pad 52B and the mounting table 20 are positioned at target positions.

[0049] Next, in step S405, as shown in FIG. 5(c), the pad movement control unit 74 controls the pad linear motor 42a of the pad linear movement mechanism 42 so as to move (advance) the side pad 52A together with the arm 51 toward the transported product P. Next, the process proceeds to step S406, where the force sensor 59 determines whether the side pad 52A has come into contact with the transported product P. If the pad movement control unit 74 determines that the side pad 52A has not come into contact with the transported product P (No), the process returns to step S405, where the side pad 52A continues to move (advance) toward the transported product P. On the other hand, if the pad movement control unit 74 determines that the side pad 52A has come into contact with the side surface Ps of the transported product P (Yes), the process stops driving the pad linear movement motor 42a, and the process proceeds to step S407.

[0050] Next, in step S407, upon receiving a drive stop signal for the pad linear motor 42a from the pad movement control unit 74, the suction control unit 76 starts the suction pump 54. As a result, negative pressure is generated inside the side pad 52A selected by the switching valve 56 while the side pad 52A is in contact with the side surface Ps of the transported product P. The suction control unit 76 transmits control signals to the suction pump 54, the switching valve 56, and the relief valve 57 shown in FIG. 2 based on at least one signal from the pad lift control unit 73, the pad movement control unit 74, or the detection signal from the pressure gauge 58, to control their operations.

[0051] Next, in step S408, the suction control unit 76 determines whether the suction pressure (negative pressure) measured by the pressure gauge 58 has become equal to or less than a predetermined pressure. If the suction control unit 76 determines that the suction pressure has not become equal to or less than the predetermined pressure (No), the process returns to step S407 and continues suction by the suction pump 54. If the suction pressure has become equal to or less than the predetermined pressure (Yes), the process proceeds to step S409.

[0052] 5(d), the pad movement control unit 74 controls the pad linear motor 42a of the pad linear mechanism 42 to draw the transported article P horizontally up to the mounting table 20 while the side pad 52A is adsorbed to the side surface Ps of the transported article P. Specifically, the pad movement control unit 74 causes the side pad 52A to retreat (move) in the horizontal direction (X-axis direction) based on the detection signal of the encoder attached to the pad linear motor 42a until at least the entire bottom surface of the transported article P comes into contact with the mounting surface 21 of the mounting table 20.

[0053] Finally, the process proceeds to step S410, where the suction control unit 76 stops the suction pump 54 and then opens the relief valve 57. This releases the suction pressure of the side pad 52A to atmospheric pressure (pressure relief), and the suction of the side surface Ps of the transported product P by the side pad 52A is released.

[0054] Through this series of steps, the pad linear motion mechanism 42 is used to move the side pad 52A in the horizontal direction (X-axis direction) at the start of transport, thereby allowing the side pad 52A to abut against the side surface Ps of the transported item P. Next, the suction mechanism 50 is used to suck the side pad 52A onto the side surface Ps of the transported item P by air suction. Thereafter, the pad linear motion mechanism 42 is used to move the side pad 52A in the horizontal direction (X-axis direction) so as to pull the side pad 52A, with the side surface Ps of the transported item P now adsorbed, onto the mounting table 20. This allows the bottom surface of the transported item P to slide from the placement surface TA of the shelf C to the mounting surface 21 of the mounting table 20, allowing the transported item P to be quickly placed on the mounting table 20.

[0055] 4-2. Control flow for delivery of transported item P 1 to 3, and further with reference to FIGS. 6 to 8, the dispensing control by the control device 70 will be described below. First, as shown in FIG. 6, in step S601, travel control of the carriage 2 of the conveyance system 1 is performed, and the conveyance system 1 on which the transported item P is placed is moved to the transport destination point. Specifically, as shown in FIG. 3, the carriage travel control unit 71 sets a transport route for the carriage 2 from the transport start point to the transport destination point based on the transport start point, the transport destination point, and information on the transported item P (specifically, the size of the transported item P, the height H3 of the installation surface, etc.) input from the input device 7, and controls the drive device (not shown) of the carriage 2, etc.

[0056] Next, in step S602, upon receiving a detection signal from the carriage travel control unit 71 indicating that the carriage has reached the transport destination, the control device 70 raises and lowers the top surface pad 52B and the mounting table 20 according to the height of the transported product P and the height of the installation surface TB, as shown in FIG. 7(a). Specifically, the pad lift control unit 73 controls the pad lift motor 41a of the pad lift mechanism 41 so that the Z-axis position of (the tip surface of) the top surface pad 52B is the same height as the height of the transported product P placed on the mounting table 20 (the height of the top surface Pc). In addition, the platform lift control unit 75 controls the platform lift motor 45a of the platform lift mechanism 45 so that the height H4 of the mounting surface 21 of the mounting table 20 is the same height as the height H3 of the installation surface TB of the transported product P. These motor controls are performed based on detection signals from encoders attached to the various motors 41a and 45a so that the top surface pad 52B and the mounting table 20 are at target heights in the Z axis. Furthermore, in order to perform axis adjustment in the X-axis direction, the carriage travel control unit 71 may rotate the carriage 2 as necessary. In addition, although not directly shown in FIG. 2, the pad movement control unit 74 may control the rotation motor 44a of the rotation mechanism 44 to rotate the top surface pad 52B.

[0057] 7(b), the transported product detection unit 72 uses the imaging device 8 to detect the position of the top surface Pc of the transported product P placed on the mounting table 20. In step S604, the control device 70 controls the movement mechanism 40 to adjust the position of the top surface pads 52B on the top surface Pc of the transported product P. Specifically, the pad movement control unit 74 controls the pad linear motors 42a, 43a of the pad linear movement mechanisms 42, 43 so that the X-axis and Y-axis positions of the top surface pads 52B are located at the center of the top surface Pc of the transported product P when viewed from the Z-axis direction, and all of the top surface pads 52B are in contact with the top surface Pc.

[0058] Next, in step S605, the suction control unit 76 controls the switching of the switching valve 56 so that the suction of the suction pump 54 is switched from the side pad 52A to the top pad 52B, and then starts the suction pump 54. As a result, a negative pressure is generated inside the top pad 52B while the top pad 52B is in contact with the top surface Pc of the transported product P.

[0059] Next, in step S606, the suction control unit 76 determines whether the suction pressure (negative pressure) measured by the pressure gauge 58 is equal to or less than a predetermined pressure. If the suction control unit 76 determines that the suction pressure is not equal to or less than the predetermined pressure (No), the process returns to step S605 and continues suction by the suction pump 54. If the suction pressure is equal to or less than the predetermined pressure (Yes), the process proceeds to step S607.

[0060] 5(c), the pad lifting / lowering control unit 73 controls the pad lifting / lowering mechanism 41 so that the transported item P placed on the mounting table 20 is lifted while all of the top surface pads 52B are attached to the top surface Pc of the transported item P. Specifically, the pad lifting / lowering control unit 73 controls the pad lifting / lowering motor 41a of the pad lifting / lowering mechanism 41 so that the height of the bottom surface Pb of the lifted transported item P is higher than the height H4 of the mounting surface 21 and the height H3 of the installation surface TB. In this way, the pad lifting / lowering control unit 73 lifts the top surface pads 52B, and the transported item P can be suspended.

[0061] 5(d), in step S608, the pad movement control unit 74 controls the pad linear movement mechanism 42 to horizontally discharge the transported article P from the mounting table 20 to above the installation surface TB of the transported article P. The pad movement control unit 74 controls the pad linear movement motor 42a of the pad linear movement mechanism 42 to move (advance) the top surface pad 52B together with the arm 51 toward the transported article P. In this way, the pad movement control unit 74 moves the top surface pad 52B in the X-axis direction, and can move the suspended transported article P above the installation surface TB.

[0062] Next, in step S609, the pad movement control unit 74 adjusts the position of the top surface pad 52B in the horizontal direction (X-axis direction and Y-axis direction). Specifically, the pad movement control unit 74 controls the pad linear movement motors 42a, 43a of the pad linear movement mechanisms 42, 43 so that the bottom surface Pb of the transported product P coincides with the installation surface TB when viewed from the vertical direction (Z-axis direction).

[0063] Next, in step S610, as shown in FIG. 8(a), the pad movement control unit 74 controls the pad lift motor 41a of the pad lift mechanism 41 so as to move (lower) the top surface pad 52B together with the arm 51 toward the top surface of the transported product P. Next, the process proceeds to step S611, where the force sensor 59 determines whether the top surface pad 52B has come into contact with the transported product P. If the pad movement control unit 74 determines that the top surface pad 52B has not come into contact with the transported product P (No), the process returns to step S610, where the top surface pad 52B continues to move (lower) toward the transported product P. On the other hand, if the pad movement control unit 74 determines that the top surface pad 52B has come into contact with the side surface Ps of the transported product P (Yes), the process stops driving the pad lift motor 41a and proceeds to step S612.

[0064] Proceeding to step S612, the suction control unit 76 stops the suction pump 54 and then opens the relief valve 57. As a result, the suction pressure of the side pad 52A is released to atmospheric pressure (pressure release), and the suction of the top surface Pc of the transported item P by the side pad 52A is released.

[0065] This series of steps allows the transported item P to be placed on the placement surface TB without sliding relative to the placement surface TB, thereby avoiding snagging or misalignment due to friction between the bottom surface Pb of the transported item P and the placement surface TB. This allows the transported item P to be accurately and smoothly placed on the placement surface TB from the transport system 1 that has reached its destination. The height H4 of the placement surface 21 of the placement table 20 is adjusted before the transported item is retracted and before the transported item is delivered, allowing the transported item P to be retracted and delivered smoothly and quickly. In particular, the height H2 of the placement surface 21 of the placement table 20 is adjusted to the same height as the height H1 of the placement surface TA of the transported item P before the transported item is retracted, allowing the transported item P to be retracted smoothly and quickly. Furthermore, the height H4 of the placement surface 21 of the placement table 20 is adjusted to the same height as the height H3 of the placement surface TB of the transported item P before the transported item P is delivered, allowing the transported item P to be delivered smoothly and quickly with a small range of movement.

[0066] In this state, the pad movement control unit 74 may terminate the movement control of the pad 52 and move the carriage 2 (backward) to separate the pad 52 from the transported item P. However, in this embodiment, the controls shown in FIGS. 8(b) and 8(c) may also be performed. Specifically, as shown in FIG. 8(b), the pad lifting control unit 73 controls the pad lifting mechanism 41 to lift the top surface pad 52B to the same height as the height in steps S607 to S609 so as to separate the pad 52B from the top surface Pc of the transported item P. Next, as shown in FIG. 8(c), the pad movement control unit 74 controls the pad linear motion motor 42a of the pad linear motion mechanism 42 to retract the pad 52A together with the arm 51 in the horizontal direction. In this way, the pad 52A is moved along the same route as the delivery route of the transported item P, thereby avoiding mechanical interference with surrounding objects and the like during movement.

[0067] Furthermore, in this embodiment, the pads 52 include side pads 52A that suck the side surfaces Ps of the transported item P and top surface pads 52B that suck the top surface Pc of the transported item P, and the switching valve 56 can easily and quickly switch between suction by the side surface pads 52A and suction by the top surface pads 52B. However, for example, as in a modified example shown in Figures 9(a) and (b), the suction mechanism 50 may further include a swinging mechanism 53 that swings the pads 52 so as to change the suction direction of the pads 52 between a direction facing the side surfaces Ps of the transported item P and a direction facing the top surface Pc of the transported item P.

[0068] Specifically, in the swing mechanism, the tip portion 51a of the arm 51 is hingedly attached to the arm body 51b so as to be rotatable (around the Y axis), and the tip portion 51a of the arm 51 and the arm body 51b are connected by a power transmission belt 53b. The power transmission belt 53b is engaged with (the output shaft of) a motor 53a attached to the arm body 51b and engaged with a pulley 53c attached to the tip portion 51a. By rotating the motor 53a through a rotation angle range of 0° to 90°, the tip portion 51a can be rotated via the power transmission belt 53b. The suction direction of the pad 52 can be changed to either a direction facing the side surface Ps of the transported item P or a direction facing the top surface Pc of the transported item P. In this way, by swinging the pad 52 by the swing mechanism 53, one pad 52 can perform the functions of adsorbing both the side surface Ps of the transported item P and the top surface Pc of the transported item P.

[0069] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as set forth in the claims.

[0070] In this embodiment, the control device controls the movement of the pad of the suction mechanism, the pad suction, and the mounting table, but for example, these may be operated manually by an operator without using the control device. [Explanation of symbols]

[0071] 1: conveying system, 2: cart, 3: picking device, 20: placing table, 40: moving mechanism, 41: pad lifting mechanism, 42: pad linear motion mechanism, 45: table lifting mechanism, 50: suction mechanism, 52: pad, 52A: side pad, 52B: top pad, 53: swinging mechanism, P: conveyed product, Ps: side, Pc: top

Claims

1. A cart that travels independently along a route from the transport start point to the transport destination point of the transported goods; a picking device attached to the carriage, which pulls in the transported item at the transport start point and delivers the transported item at the transport destination point, The picking device is a platform on which the transported item is placed; a suction mechanism having a pad that suctions the surface of the transported product by air suction; a moving mechanism including a pad lifting mechanism that lifts and lowers the pad, and a pad linear motion mechanism that horizontally moves the pad in a retracting direction and a dispensing direction, A conveying system characterized in that the suction mechanism is a mechanism that adsorbs the pad to the side of the transported item at the starting point of the conveyance, and adsorbs the pad to the top surface of the transported item placed on the mounting table at the destination point of the conveyance.

2. 2. The transfer system according to claim 1, wherein the moving mechanism further comprises a table lifting mechanism for lifting and lowering the stage.

3. 2. The transport system according to claim 1, wherein the pads include a side pad that sucks the side of the transported item, and a top pad that sucks the top of the transported item placed on the platform at the transport destination point.

4. The conveying system according to claim 1, characterized in that the suction mechanism further includes a swinging mechanism that swings the pad so as to change the suction direction of the pad to either a direction facing the side of the transported item or a direction facing the top surface of the transported item.

5. the transport system further includes a control device that controls the movement of the pad by the movement mechanism; the control device controls the pad linear motion mechanism so as to pull the transported product horizontally to the mounting table at the transport start point with the pad attached to the side surface; The transport system described in claim 1, characterized in that at the destination point of the transport, the pad lifting mechanism is controlled so that the transported item placed on the placement table is lifted while the pad is adsorbed to the top surface, and then the pad linear motion mechanism is controlled so that the transported item is horizontally ejected from the placement table to above the installation surface of the transported item, and the pad lifting mechanism is controlled so that the pad is lowered until the transported item contacts the installation surface.

6. the moving mechanism further includes a platform lifting mechanism that lifts and lowers the mounting platform; the control device further controls the lifting and lowering of the mounting table by the table lifting mechanism, the control device controls the platform lifting mechanism at the transfer start point before the transported product is drawn in so that the height of the loading surface of the placement table is the same as the height of the placement surface of the transported product; The transport system according to claim 5, characterized in that, before the transported item is removed at the destination point of the transport, the platform lifting mechanism is controlled so that the height of the loading surface of the platform is the same as the height of the installation surface of the transported item.

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