Holding device and transport device

Abstract

To provide a holding device capable of suppressing interference between a holding unit and an obstacle and of widening a movable range.SOLUTION: A holding device includes a support member, a first holding unit, a second holding unit, and a control part. The first holding unit is rotatably supported by the support member and has a first holding part. The second holding unit is rotatably supported by the support member independently of the first holding unit and has a second holding part. The control part controls operation of the first holding unit and the second holding unit. The control part switches between the first holding unit and the second holding unit to use for holding an object to hold in the state that the first holding part and the second holding part face mutually different directions by rotating the first holding part and the second holding part, and performs control so as to change postures to the support member by rotating at least either the first holding unit or the second holding unit with respect to the support member.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present invention relates to a holding device and a transport device. [Background technology]

[0002] A picking robot equipped with a robot hand having a plurality of holding units for holding an item has been known. This type of picking robot can handle a variety of items by using the plurality of holding units appropriately. However, there is a problem that such holding units are prone to interference with surrounding obstacles, and the movable range of the robot hand is narrow. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-685 A [Patent Document 2] JP 2002-66861 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a holding device and a transport device that are capable of suppressing interference between the holding unit and surrounding obstacles and increasing the range of motion. [Means for solving the problem]

[0005] The holding device of the embodiment has a support member, a first holding unit, a second holding unit, and a control unit. The first holding unit is rotatably supported by the support member. The first holding unit has a first holding part that holds a holding object. The second holding unit is rotatably supported by the support member independently of the first holding unit. The second holding unit has a second holding part that holds a holding object. The control unit controls the operation of the first holding unit and the second holding unit. The control unit controls the first holding unit and the second holding unit to switch which of the first holding unit and the second holding unit is used to hold the holding object by rotating the first holding unit and the second holding unit while the first holding unit and the second holding unit are facing in different directions, and controls at least one of the first holding unit and the second holding unit to change its attitude relative to the support member by rotating the first holding unit and the second holding unit relative to the support member. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic diagram of a picking robot according to an embodiment. [Diagram 2] FIG. 2 is a side view of a robot hand according to an embodiment. [Diagram 3] FIG. 2 is a front view of the robot hand according to the embodiment. [Figure 4] FIG. 2 is a perspective view for explaining the positions of multiple motors in the robot hand. [Diagram 5] FIG. 4 is a perspective view showing the interrelationships between gears constituting a plurality of rotation drive mechanisms. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. 4 is a diagram for explaining the arrangement of negative pressure supply piping. [Figure 10] FIG. 4 is a diagram for explaining the arrangement of relay pipes. [Figure 11] 11A and 11B are diagrams for explaining the operation of the robot hand when switching units. [Figure 12] 11A to 11C are diagrams for explaining the operation of the robot hand when the posture of the clamping unit is changed. [Figure 13] 11A and 11B are diagrams for explaining the operation of the robot hand when changing the posture of the suction unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, a holding device and a transport device according to an embodiment will be described with reference to the drawings. The holding device and the conveying device of the embodiment are described using an XYZ Cartesian coordinate system. The Z-axis direction corresponds to the vertical direction, the +Z direction is defined as the upward direction, and the -Z direction is defined as the downward direction. The X-axis direction and the Y-axis direction are perpendicular to each other in a horizontal plane. In the horizontal plane, the direction in which the clamping claws of the clamping unit described later open and close is defined as the X-axis direction. In the horizontal plane, the direction perpendicular to the direction in which the clamping claws open and close is defined as the Y-axis direction.

[0008] FIG. 1 is a schematic diagram showing a schematic configuration of a picking robot 10 of the present embodiment. As shown in FIG. 1, the picking robot 10 includes a robot hand 11, an arm 12, and a control unit 13. The robot hand 11 holds a holding target P to be transported. The arm 12 moves the robot hand 11 to a predetermined location. The control unit 13 controls the robot hand 11 and the arm 12. More specifically, the control unit 13 of the picking robot 10 has a controller that controls the entire system. The controller is composed of a planning controller that plans the actions of the arm 12 and the robot hand 11, and an image processing controller that performs recognition processing of camera information, etc. The configuration of the robot hand 11 will be described in detail later. The picking robot 10 of this embodiment corresponds to a transport device in the claims, and the robot hand 11 of this embodiment corresponds to a holding device in the claims.

[0009] The configuration and operation of the picking robot 10 will be outlined below. The picking robot 10 is used, for example, as a picking robot for logistics. The picking robot 10 holds various objects P placed in various situations at the source S1 and moves them to the destination S2. The use of the picking robot 10 is not limited to logistics, but can also be widely applied to industrial and other uses. The picking robot 10 of this embodiment is not limited to a device whose main purpose is to transport the objects P, but also includes a device that transports or moves an item as part of another purpose, such as product assembly.

[0010] The transfer source S1 is, for example, various conveyors, pallets, containers, etc., but is not limited to these. At the transfer source S1, a plurality of types of objects to be held P with different dimensions and weights are placed in random positions in arbitrary postures. In this embodiment, the dimensions of the objects to be held P to be transferred vary from, for example, several centimeters square to several tens of centimeters square. The weights of the objects to be held P vary from, for example, several tens of grams to several kilograms. Note that the dimensions and weights of the objects to be held P are not limited to the above examples.

[0011] The destination S2 is, like the source S1, for example, various conveyors, pallets, containers, etc., but is not limited to these. Note that the source S1 and the container of the destination S2 broadly mean a member capable of accommodating the holding object P, for example, a box-shaped member.

[0012] The arm 12 is composed of, for example, a six-axis vertical articulated arm. The arm 12 includes a plurality of arm members 15 and a plurality of joints 16. The joints 16 rotatably connect the arm members 15 connected to the joints 16 to each other. The arm 12 may be composed of, for example, a four-axis vertical articulated arm, or a three-axis orthogonal arm. The arm 12 may have a mechanism for moving the robot hand 11 to a desired position by a configuration other than a vertical articulated arm and an orthogonal arm. Although not shown, the arm 12 includes a sensor or the like for detecting the angle formed by the arm member 15 at each joint 16.

[0013] Although not shown in the figure, the picking robot 10 further includes sensors installed near the source S1 and the destination S2. The sensors are composed of, for example, an RGB-D sensor, a camera, a contact sensor, a distance sensor, etc. The sensors acquire, for example, information about the holding target P placed at the source S1, information about the status of the source S1 or the destination S2, etc.

[0014] The control unit 13 manages and controls each part of the picking robot 10. The control unit 13 acquires various information detected by sensors, and controls the position and operation of the robot hand 11 based on the acquired information. The control unit 13 is composed of a microcomputer equipped with a processor such as a CPU (Central Processing Unit). The control unit 13 is realized, for example, by a processor such as a CPU executing a program stored in a memory or an auxiliary storage device. At least a part of the control unit 13 may be realized by hardware such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array), or may be realized by cooperation between software and hardware. As described above, the controller of the control unit 13 has an image processing controller that processes recognition results, etc., and a recognition system device such as a camera is linked under the image processing controller. In addition, the planning controller is composed of a controller that controls the arm 12 and a controller that controls the robot hand 11.

[0015] The robot hand 11 will be described below. Fig. 2 is a side view of the robot hand 11 as viewed from the +X direction. Fig. 3 is a front view of the robot hand 11 as viewed from the +Y direction. In this specification, a view of each device as viewed from the +X direction is referred to as a side view, and a view of each device as viewed from the +Y direction is referred to as a front view.

[0016] As shown in Fig. 2, the robot hand 11 has a base plate 20, a clamping unit 21, and a suction unit 22. Here, the robot hand 11 also includes a first rotation drive mechanism 23, a second rotation drive mechanism 24, a third rotation drive mechanism 25, and a fourth rotation drive mechanism 26, which are illustrated in Figs. 3 to 5 and other drawings described below. Each of the rotation drive mechanisms 23, 24, 25, and 26 will be described in detail later with reference to other drawings such as Figs. 3 to 5. The base plate 20 of this embodiment corresponds to a support member in the claims. The clamping unit 21 of this embodiment corresponds to a first holding unit in the claims. The suction unit 22 of this embodiment corresponds to a second holding unit in the claims.

[0017] The base plate 20 is composed of a plate-shaped member. The base plate 20 has a first surface 20a and a second surface 20b opposite to the first surface 20a. The base plate 20 supports a clamping unit 21 and a suction unit 22. The clamping unit 21 and the suction unit 22 face the first surface 20a of the base plate 20 and are arranged side by side in the Y-axis direction. The base plate 20 is arranged only on one side of the clamping unit 21 and the suction unit 22, and is not arranged on the other side. In other words, the clamping unit 21 and the suction unit 22 are not sandwiched from both sides by the base plate 20, but are supported by the base plate 20 in a cantilever structure.

[0018] The suction unit 22 is disposed facing the first surface 20a of the base plate 20. The clamping unit 21 is disposed on the opposite side of the suction unit 22 from the side on which the base plate 20 is located. That is, these two units 21, 22 are disposed in the order of the suction unit 22 and the clamping unit 21 from the first surface 20a side of the base plate 20. At least a part of the base plate 20, at least a part of the suction unit 22, and at least a part of the clamping unit 21 are disposed at positions that overlap each other when viewed from a normal direction (Y-axis direction) of the first surface 20a that intersects with the first surface 20a. In the following description, the direction in which the base plate 20, the suction unit 22, and the clamping unit 21 overlap each other (the Y-axis direction) will be referred to as the thickness direction of the robot hand 11.

[0019] The clamping unit 21 has a clamping portion 28, and holds the object to be held P by clamping it from the side using clamping claws 29 described later. The clamping unit 21 is supported on the base plate 20 so as to be rotatable within a plane parallel to the first surface 20a (within the XZ plane). The clamping portion 28 of this embodiment corresponds to a first holding portion in the claims.

[0020] The suction unit 22 has a suction portion 31, and holds the object to be held P by negative pressure suction using a suction pad 32 described later. The suction unit 22 is supported on the base plate 20 so as to be rotatable within a plane parallel to the first surface 20a (within the XZ plane). The suction portion 31 of this embodiment corresponds to a second holding portion in the claims.

[0021] As shown in Fig. 2, an ejector 48 and a pipe guide 49 are disposed on the second surface 20b of the base plate 20. The ejector 48 uses compressed air to generate negative pressure that serves as the suction force of the suction pad 32. The pipe guide 49 guides the position of a negative pressure supply pipe 50 (described later) on one surface 44a of the base plate cover 44. The negative pressure supply pipe 50 is not shown in Fig. 2.

[0022] The rotation drive mechanism of the robot hand 11 will be briefly described below. The robot hand 11 has a function of switching which of the clamping unit 21 and the suction unit 22 is used to hold the object P to be held depending on the object P to be held, a function of changing the attitude of the clamping unit 21, a function of changing the attitude of the suction portion 31, and a function of opening and closing the clamping claws 29. To achieve these functions, the robot hand 11 is equipped with a first rotation drive mechanism 23, a second rotation drive mechanism 24, a third rotation drive mechanism 25, and a fourth rotation drive mechanism 26 as rotation drive mechanisms.

[0023] The first rotation drive mechanism 23 shown in Figures 3 and 4 is used both when switching between the clamping unit 21 and the suction unit 22 to be used, and when changing the attitude of the clamping unit 21. The second rotation drive mechanism 24 shown in Figure 4 is used when correcting a change in the attitude of the suction unit 22 accompanying a change in the attitude of the clamping unit 21. The third rotation drive mechanism 25 shown in Figure 4 is used when changing the attitude of the suction section 31. The fourth rotation drive mechanism 26 is used when opening and closing the clamping claws 29 that constitute the clamping section 28.

[0024] In the following, for ease of understanding, the first rotation drive mechanism 23 will be referred to as the unit switching and clamping posture change mechanism 23, the second rotation drive mechanism 24 will be referred to as the suction unit posture correction mechanism 24, the third rotation drive mechanism 25 will be referred to as the suction posture change mechanism 25, and the fourth rotation drive mechanism 26 will be referred to as the clamping claw opening and closing mechanism 26.

[0025] The installation positions of the motors constituting each of the rotary drive mechanisms will be described first. FIG. 4 is a perspective view for explaining the positions of a plurality of motors. 4, a first motor 35 constituting the unit switching and clamping position change mechanism 23 is installed on the base plate 20. A second motor 36 constituting the suction unit position correction mechanism 24 is installed on the clamping unit 21. A third motor 37 constituting the suction position change mechanism 25 is installed on the suction unit 22. A fourth motor 38 constituting the clamping jaw opening / closing mechanism 26 is installed on the clamping unit 21. Each of the first motor 35, the second motor 36, the third motor 37, and the fourth motor 38 is formed of, for example, a servo motor.

[0026] FIG. 6 is a front view showing the configuration of the base plate 20. As shown in FIG. As shown in FIG. 3 and FIG. 6, the first motor 35, the first shaft 41, the first gear 42, and the second gear 43, which are components of the unit switching and clamping position changing mechanism 23, are arranged on the second surface 20b of the base plate 20. The first shaft 41 is connected to the first motor 35. The first shaft 41 extends downward (in the Z-axis direction) from the first motor 35. The first gear 42 is connected to the lower end of the first shaft 41. The first gear 42 is rotatable about the axis of the first shaft 41. The second gear 43 is arranged in a state of meshing with the first gear 42. The second gear 43 converts the rotation of the first gear 42, which rotates around the Z-axis, into rotation around the Y-axis. In this embodiment, the first gear 42 and the second gear 43 are configured as helical gears, but the type of gear is not particularly limited. The first shaft 41, the first gear 42, and the second gear 43 are covered by a base plate cover 44 (see FIG. 2).

[0027] Fig. 5 is a perspective view showing the interrelationships between various gears constituting a plurality of rotation drive mechanisms. In Fig. 5, in order to make the positional relationship between the plurality of gears easier to see, illustration of members other than the gears is appropriately omitted. As shown in FIG. 5, the second gear 43 is connected to a second shaft 46 fixed to the clamping unit 21. As a result, when the first motor 35 rotates, the clamping unit 21 rotates in the XZ plane via the first shaft 41, the first gear 42, the second gear 43, and the second shaft 46. The axis of the second shaft 46 is the first rotation axis AX1 when the clamping unit 21 and the suction unit 22 rotate together when the units are switched, and is the second rotation axis AX2 when the clamping unit 21 changes its posture. That is, the first rotation axis AX1 when the clamping unit 21 and the suction unit 22 are switched and the second rotation axis AX2 when the clamping unit 21 changes its posture are arranged on a common axis.

[0028] 6, a top plate 52 is provided on the top of the base plate 20. A force sensor 53 is disposed on the upper surface of the top plate 52. The force sensor 53 detects the force that each unit 21, 22 receives when the clamping unit 21 or the suction unit 22 comes into contact with an object. The detection value of the force sensor 53 is output to the control unit 13 and used to control each part of the clamping unit 21 or the suction unit 22.

[0029] A bearing 55 is disposed on the first surface 20a of the base plate 20 at a position corresponding to the second gear 43 disposed on the second surface 20b. The bearing 55 allows the suction unit 22 to rotate smoothly relative to the base plate 20.

[0030] FIG. 7 is a front view showing the configuration of the clamping unit 21. As shown in FIG. 7, the clamping unit 21 includes a clamping unit base material 57, a clamping section 28, a clamping claw opening / closing mechanism 26, and a second motor 36. The clamping section 28 includes a link section 58 and a plurality of clamping claws 29. The clamping unit 21 holds the object P to be held in a clamped state by the plurality of clamping claws 29. The second motor 36 is a component of the suction unit attitude correction mechanism 24.

[0031] The clamping unit base material 57 supports each member such as the link section 58, the clamping claw opening / closing mechanism 26, and the second motor 36. The clamping section 28 of the present embodiment includes two clamping claws 29 connected to the link section 58. Note that the clamping section 28 may include three or more clamping claws, and the number of clamping claws is not particularly limited.

[0032] The link portion 58 is composed of two parallel links 59. Each of the two clamping claws 29 is connected to each of the two parallel links 59. The two clamping claws 29 open and close by movement of the link portion 58, moving upward in the +Z direction while moving in the X-axis direction in a direction that increases the distance between them, and moving downward in the -Z direction while moving in the X-axis direction in a direction that decreases the distance between them.

[0033] The clamping claw opening / closing mechanism 26 includes a fourth motor 38, a third gear 61, a fourth gear 62, and a fifth gear 63. The third gear 61 is connected to the fourth motor 38. The fourth gear 62 meshes with the third gear 61. The fifth gear 63 meshes with the fourth gear 62. When the third gear 61 rotates by the drive of the fourth motor 38, the fourth gear 62 and the fifth gear 63 rotate in opposite directions to each other in the XZ plane. The two clamping claws 29 perform either an opening operation or a closing operation depending on the direction in which the fourth gear 62 and the fifth gear 63 rotate. The clamping claw opening / closing mechanism 26 is covered by a clamping unit cover 64 (see FIG. 2).

[0034] A displacement sensor 65 is disposed above the clamping claw 29. The displacement sensor 65 detects the force that the clamping claw 29 receives when the clamping claw 29 comes into contact with an object. The detection value of the clamping claw 29 is output to the control unit 13 and used to control the clamping unit 21. In this way, in addition to a configuration in which the value of the displacement sensor 65 is directly read by the control unit 13, a configuration in which a controller dedicated to hand control monitors the value of the displacement sensor 65 and performs contact determination with an item, etc. may also be used.

[0035] The second motor 36 is disposed on the clamping unit base material 57 in the -X direction relative to the fourth motor 38. As shown in Fig. 5, the sixth gear 66 is disposed in the +Y direction relative to the second motor 36. The sixth gear 66 is connected to the second motor 36. The sixth gear 66 meshes with a seventh gear 67 (described later) of the suction unit 22. The sixth gear 66 constitutes the suction unit attitude correction mechanism 24 together with the second motor 36.

[0036] FIG. 8 is a front view showing the configuration of the suction unit 22. As shown in FIG. 8, the suction unit 22 includes a suction link part 69, a suction part 31, a suction attitude change mechanism 25, and a seventh gear 67. The suction part 31 includes a base 71 and a plurality of suction pads 32. The suction unit 22 holds the holding target P in a state of negative pressure suction by the plurality of suction pads 32.

[0037] The suction link part 69 has a first surface 69a and a second surface 69b opposite to the first surface 69a. The second surface 69b of the suction link part 69 faces the first surface 20a of the base plate 20. The suction link part 69 has an opening 69h. The opening 69h is provided with pipe joints 73 in a number corresponding to the number of the suction pads 32. The pipe joints 73 communicate with a negative pressure supply pipe 50 described later. A relay pipe 74 is disposed in a space between the plurality of pipe joints 73 and the suction part 31. The second surface 69b of the suction link part 69 is provided with a plurality of inlets 79 described later. A negative pressure flow path (not shown) that communicates between the pipe joints 73 and the inlets 79 is formed inside the suction link part 69.

[0038] The suction unit 31 includes four suction pads 32 arranged on a rectangular base 71. The suction pads 32 come into contact with one side of the object to be held P and adsorb the object to be held P by negative pressure. The four suction pads 32 are arranged near the four corners of the base 71. Therefore, the four suction pads 32 are arranged in a rectangular shape. The number of suction pads 32 does not have to be four and is not particularly limited. The arrangement of the suction pads 32 does not have to be rectangular and is not particularly limited.

[0039] The suction posture change mechanism 25 has a fourth motor 38 disposed on the suction link part 69. The suction part 31 rotates in the XZ plane relative to the suction link part 69 as the fourth motor 38 rotates. The rotation axis of the fourth motor 38 is the third rotation axis AX3 when the posture of the suction part 31 is changed.

[0040] A seventh gear 67 is fixed to a first surface 69a of the suction link part 69. The seventh gear 67 is disposed at an end of the first surface 69a of the suction link part 69 on the opposite side (-Z direction) to the side where the suction part 31 is provided. As described above, the seventh gear 67 meshes with the sixth gear 66 connected to the second motor 36 on the clamping unit 21, and constitutes the suction unit attitude correction mechanism 24.

[0041] 5, the second shaft 46 fixed to the clamping unit 21 is inserted into the inside of the seventh gear 67. A bearing 55 (see FIG. 6) is disposed between the second shaft 46 and the suction unit 22.

[0042] 2, the base plate 20, the suction unit 22, and the clamping unit 21 are overlapped in the thickness direction of the robot hand 11. Therefore, the position of the suction link part 69 and the position of the clamping unit base material 57 in the thickness direction (Y-axis direction) of the robot hand 11 are different from each other. That is, the suction link part 69 is located in the +Y direction from the clamping unit base material 57. Also, the suction part 31 is disposed in the -Y direction with respect to the suction link part 69.

[0043] With the above configuration, when the clamping portion 28 and the suction portion 31 face in directions different from each other by 180° in a plane (XZ plane) parallel to the first surface 20a of the base plate 20, the first holding center line H1 of the clamping unit 21 and the second holding center line H2 of the suction unit 22 are arranged on the same straight line parallel to the Z axis direction. The first holding center line H1 is defined as a straight line parallel to the Z axis and passing through the center of the opening and closing direction (X axis direction) of the two clamping jaws 29 of the clamping unit 21 and the center of the width direction (Y axis direction) of one clamping jaw 29. The second holding center line H2 is defined as a straight line parallel to the Z axis and passing through the center of the rectangle in which the four suction pads 32 of the suction unit 22 are arranged as viewed from the Z axis direction. Hereinafter, the length L of the robot hand 11 is defined as the distance between the tip of the clamping claw 29 and the suction surface of the suction pad 32 when the clamping portion 28 and the suction portion 31 are facing in directions that are 180° apart from each other.

[0044] The path for supplying negative pressure to the suction pad 32 will now be described. FIG. 9 is a diagram for explaining the arrangement of the negative pressure supply pipe 50. As shown in FIG. 9, a plurality of compressed air introduction pipes 76 and a plurality of negative pressure supply pipes 50 are connected to the ejector 48. The compressed air introduction pipes 76 are arranged along the arm member 15 and the joint portion 16, and branch into a plurality of pipes with their positions regulated by guide rollers 77, each of which is connected to the ejector 48. The number of compressed air introduction pipes 76 and negative pressure supply pipes 50 corresponds to the number of suction pads 32. In the case of this embodiment, the number of compressed air introduction pipes 76 and negative pressure supply pipes 50 is four each.

[0045] The negative pressure supply pipes 50 extend downward (-Z direction) along one surface 44a of the base plate cover 44 by the pipe guide 49, and then curve and extend upward (+Z direction). The lower ends of the curved parts of the negative pressure supply pipes 50 are disposed at a position equivalent to the lower end of the base plate cover 44 or at a position higher than the lower end of the base plate cover 44. The compressed air introduction pipe 76 and the negative pressure supply pipe 50 are formed, for example, of a spiral tube made of resin wound in a helical shape. This allows the compressed air introduction pipe 76 and the negative pressure supply pipe 50 to expand and contract in response to the operation of each part. The compressed air introduction pipe 76 and the negative pressure supply pipe 50 may be formed of a tube of another shape.

[0046] As shown in FIG. 6, a cutout portion 20k is formed by cutting out a corner in a rectangular shape on the lower part of the base plate 20 on the side opposite to the side where the first gear 42 is provided in the X-axis direction. Therefore, the width of the lower part of the base plate 20 is narrower than the width of the upper part of the base plate 20. On the other hand, as shown in FIG. 8, the suction link portion 69 is formed to have the same width in the vertical direction. As a result, as shown in FIG. 9, when the suction unit 22 and the base plate 20 are overlapped as viewed from the +Y direction, a part of the suction link portion 69 is exposed from the base plate 20. A plurality of inlets 79 are provided in the area of ​​the suction link portion 69 exposed to the outside from the cutout portion 20k of the base plate 20. The negative pressure supply pipe 50 is connected to the inlet 79.

[0047] 9 shows a state in which the clamping unit 21 is used and the suction unit 22 is not used, and the suction unit 22 is in a position in which the suction part 31 faces vertically upward (+Z side). In this position, the negative pressure supply pipe 50 is wound counterclockwise from the pipe guide 49 side toward the inlet 79 side and connected to the inlet 79. Therefore, when switching the units, the suction unit 22 needs to be rotated clockwise. This allows the negative pressure supply pipe 50 to be deformed from a bent state to an extended state without any problems. That is, the negative pressure supply pipe 50 is arranged so as to be wound from the inlet 79 side to the suction pad 32 side in a direction opposite to the direction in which the suction unit 22 rotates.

[0048] In the above configuration, the compressed air introduced through the compressed air inlet pipe 76 is converted into negative pressure air by the ejector 48. The negative pressure air is supplied to the intake port 79 through the negative pressure supply pipe 50, and is supplied to the pipe joint 73 through a negative pressure flow path formed inside the suction link part 69.

[0049] Although not shown in Figure 9, in addition to the negative pressure supply piping 50, electrical wiring for transmitting signals to each motor is also configured to be routed around the second surface 20b side of the base plate 20, similar to the negative pressure supply piping 50.

[0050] Fig. 10 is a schematic diagram for explaining the arrangement of the relay pipes 74. In Fig. 10, in order to make the arrangement of the relay pipes 74 easier to see, only the relay pipes 74, the suction pads 32, and the pipe joints 73 are shown. 10, a plurality of relay pipes 74 are provided in the space between the plurality of suction pads 32 and the plurality of pipe joints 73. The relay pipes 74 connect the suction pads 32 and the pipe joints 73. The relay pipes 74 transport negative pressure air supplied from the negative pressure flow path of the suction link unit 69 to the suction pads 32. The relay pipes 74 are arranged in a spiral shape in the space between the suction pads 32 and the pipe joints 73. In this embodiment, the entire relay pipes 74 are arranged in a spiral shape, but a part of the relay pipes may extend linearly.

[0051] 10, among the suction pads 32 arranged on the XY plane, the suction pads 32 located on the +X and -Y sides are referred to as the first suction pads 32A, the suction pads 32 located on the +X and +Y sides are referred to as the second suction pads 32B, the suction pads 32 located on the -X and +Y sides are referred to as the third suction pads 32C, and the suction pads 32 located on the -X and -Y sides are referred to as the fourth suction pads 32D. The pipe joints 73 arranged in the X-axis direction are referred to as the first pipe joint 73A, the second pipe joint 73B, the third pipe joint 73C, and the fourth pipe joint 73D, in that order from the -X side to the +X side. The row in which the pipe joints 73 are arranged is closer to the row in which the second suction pad 32B and the third suction pad 32C are arranged than to the row in which the first suction pad 32A and the fourth suction pad 32D are arranged.

[0052] Of the first suction pad 32A and the second suction pad 32B located on the +X side, the first suction pad 32A, which is located at a relatively long distance to the row of the multiple pipe fittings 73, is connected to the first pipe fitting 73A via the first relay pipe 74A. The second suction pad 32B, which is located at a relatively short distance to the row of the multiple pipe fittings 73, is connected to the second pipe fitting 73B via the second relay pipe 74B. When viewed from the +Z direction, the first relay pipe 74A is wound clockwise with a large diameter. The second relay pipe 74B is wound clockwise with a smaller diameter than the first relay pipe 74A.

[0053] Of the third suction pad 32C and the fourth suction pad 32D located on the -X side, the third suction pad 32C, which is relatively close to the row of the multiple pipe fittings 73, is connected to the third pipe fitting 73C via the third relay pipe 74C. The fourth suction pad 32D, which is relatively close to the row of the multiple pipe fittings 73, is connected to the fourth pipe fitting 73D via the fourth relay pipe 74D. When viewed from the +Z direction, the fourth relay pipe 74D is wound counterclockwise with a large diameter. The third relay pipe 74C is wound counterclockwise with a smaller diameter than the fourth relay pipe 74D.

[0054] That is, of two suction pads 32 at the same position in the X-axis direction, the relay pipe 74 connected to the suction pad 32 located relatively far from the row in which the multiple pipe fittings 73 are lined up is wound in a large turn. The relay pipe 74 connected to the suction pad 32 located relatively close to the row in which the multiple pipe fittings 73 are lined up is wound in a small turn. In addition, the relay pipe 74 connected to the two suction pads 32 located on the +X side and the relay pipe 74 connected to the two suction pads 32 located on the -X side are wound in opposite directions.

[0055] The operation of the robot hand 11 will now be described. First, the operation when switching between the clamping unit 21 and the suction unit 22 to be used will be described. FIG. 11 is a diagram for explaining the operation of the robot hand 11 when switching units. 11, during unit switching, the clamping unit 21 and the suction unit 22 rotate together within a plane (within the XZ plane) parallel to the first surface 20a of the base plate 20, while maintaining the postures of the clamping part 28 and the suction part 31 facing in directions different from each other by 180°. At this time, the first holding center line H1 of the clamping unit 21 and the second holding center line H2 of the suction unit 22 are arranged on the same straight line.

[0056] During unit switching, the control unit 13 controls the first motor 35 to a position control state, the second motor 36 to a servo lock state, the third motor 37 to a servo lock state, and the fourth motor 38 to a servo lock state. The position control state is a state in which the rotation of each motor is controlled so as to position a moving object such as the clamping unit 21 at a predetermined position by a position command signal. The servo lock state is a state in which the stopped position is maintained even if a force acts in the direction in which the motor rotates due to, for example, an external force.

[0057] When the first motor 35 rotates, the clamping unit 21 rotates in a plane (XZ plane) parallel to the first surface 20a of the base plate 20 via the first shaft 41, the first gear 42, the second gear 43, and the second shaft 46, as shown in FIG. 5. At this time, the second motor 36 is in a servo-locked state and is held in a stopped state. Therefore, the sixth gear 66 connected to the second motor 36 on the clamping unit 21 is stationary in a state of meshing with the seventh gear 67 of the suction unit 22. Therefore, the positional relationship between the sixth gear 66 and the seventh gear 67, that is, the positional relationship between the clamping unit 21 and the suction unit 22, does not change. As a result, the suction unit 22 rotates together with the clamping unit 21 in a plane (XZ plane) parallel to the first surface 20a of the base plate 20 while maintaining a posture facing in a direction different from that of the clamping unit 21 by 180°.

[0058] Since the first motor 35 is in the position control state, for example, when the clamping unit 21 is used, the control unit 13 stops the rotation of the first motor 35 at a position where the first holding center line H1 of the clamping unit 21 faces vertically downward and the second holding center line H2 of the suction unit 22 faces vertically upward. Next, when the suction unit 22 is used, the control unit 13 may stop the rotation of the first motor 35 at a position where the clamping unit 21 and the suction unit 22 are rotated together by 180° until the second holding center line H2 of the suction unit 22 faces vertically downward and the first holding center line H1 of the clamping unit 21 faces vertically upward.

[0059] When the clamping unit 21 and the suction unit 22 are rotated together during unit switching, the third motor 37 is in a servo-locked state, so that the attitude of the suction part 31 is maintained in a state where it is not tilted with respect to the suction link part 69, as shown in Fig. 11. In addition, the fourth motor 38 is in a servo-locked state, so that the two clamping claws 29 are maintained in a closed state.

[0060] Next, an operation for changing the attitude of the clamping unit 21 will be described. FIG. 12 is a diagram for explaining the operation of the robot hand 11 when the posture of the clamping unit 21 is changed. When the posture of the clamping unit 21 is changed, the control unit 13 controls the first motor 35 to a position control state, the second motor 36 to a position control state, the third motor 37 to a servo lock state, and the fourth motor 38 to a servo lock state or a position control state.

[0061] As described above, the clamping unit 21 is rotated by the first motor 35. Therefore, assuming that the attitude in which the first holding center line H1 faces vertically downward is 0°, the attitude of the clamping unit 21 can be changed by rotating the clamping unit 21 by the first motor 35 so that the first holding center line H1 faces, for example, in the range of -90° to +90°. However, as in the above-mentioned unit switching, if the second motor 36 is controlled to be in a servo-locked state, the attitude of the suction unit 22 also changes with the change in the attitude of the clamping unit 21.

[0062] Therefore, in this embodiment, the control unit 13 performs control to correct the posture of the suction unit 22 as follows so that the posture of the suction unit 22 does not change with the posture change of the clamping unit 21. Specifically, assuming that the clockwise direction in FIG. 12 is a positive angle and the counterclockwise direction is a negative angle, the clamping unit 21 is rotated so that the first holding center line H1 faces in the direction of -θ, and the suction unit 22 is rotated by +θ. As a result, the posture of the suction unit 22 does not change and the suction part 31 is maintained in a state facing vertically upward. That is, the suction unit 22 is rotated with respect to the base plate 20 in a direction that offsets the posture change of the suction unit 22 caused by the posture change of the clamping unit 21.

[0063] When the clamping unit 21 is rotated to change its posture, the third motor 37 is in a servo-locked state, so that the posture of the suction part 31 is maintained in a state where it is not tilted with respect to the suction link part 69. When the fourth motor 38 is in a servo-locked state, the clamping unit 21 changes its posture while maintaining the two clamping jaws 29 in a closed state. When the fourth motor 38 is in a position control state, the clamping unit 21 changes its posture while the two clamping jaws 29 are opened to a predetermined position.

[0064] Next, the operation of changing the attitude of the suction unit 22 will be described. FIG. 13 is a diagram for explaining the operation of the robot hand 11 when the posture of the suction unit 22 is changed. When the posture of the suction unit 22 is changed, the control unit 13 controls the first motor 35 to a servo-locked state, the second motor 36 to a servo-locked state, the third motor 37 to a position control state, and the fourth motor 38 to a servo-locked state.

[0065] The suction part 31 is rotated by the third motor 37. Therefore, assuming that an attitude in which the second holding center line H2 of the suction unit 22 faces vertically downward is 0°, the attitude of the suction part 31 can be changed by rotating the suction part 31 relative to the suction link part 69 by the third motor 37 so that the second holding center line H2 faces in the range of -90° to +90°, for example.

[0066] When the suction part 31 is rotated to change its position, the first motor 35 is in a servo-locked state, so that the position of the clamping unit 21 is maintained unchanged with the first holding center line H1 facing vertically upward. At this time, the second motor 36 is in a servo-locked state, so that the position of the suction link part 69 relative to the base plate 20 is maintained unchanged. The second motor 36 may be in a position control state to adjust the position of the suction link part 69 relative to the base plate 20. In addition, the fourth motor 38 is in a servo-locked state, so that the clamping unit 21 maintains a state in which the two clamping jaws 29 are closed.

[0067] The effects of the robot hand 11 and the picking robot 10 of this embodiment will be described below. First, as a comparative example of a robot hand, a robot hand is assumed that includes a clamping unit and a suction unit, each of which has a posture changing function. In the robot hand of the comparative example, a first rotation axis for rotating the clamping unit and the suction unit together when switching units, a second rotation axis for rotating the clamping unit when changing the posture of the clamping unit, and a third rotation axis for rotating the suction unit when changing the posture of the suction unit are arranged at different positions along the length of the robot hand. The first rotation axis is located between the second rotation axis and the third rotation axis.

[0068] In the case of the robot hand of the comparative example, the length of the robot hand is the sum of the distance from the first rotation axis to the second rotation axis, the distance from the first rotation axis to the third rotation axis, the distance from the second rotation axis to the tip of the clamping unit, and the distance from the third rotation axis to the tip of the suction unit. In the case of the robot hand of the comparative example, the length of the robot hand is likely to be long. If the length of the robot hand is long, a problem occurs in that the robot hand is likely to interfere with other obstacles when moving.

[0069] In response to this problem, the robot hand 11 of this embodiment is provided with a unit switching and clamping position changing mechanism 23 that switches between units by rotating the clamping unit 21 and the suction unit 22 integrally with respect to the base plate 20, and changes the position of the clamping unit 21 by rotating the clamping unit 21 with respect to the base plate 20. The control unit 13 switches between the clamping unit 21 and the suction unit 22 to be used to hold the object to be held by rotating the clamping unit 21 and the suction unit 22 with the clamping section 28 and the suction section 31 facing in different directions, and controls at least one of the clamping unit 21 and the suction unit 22 to change its position with respect to the base plate 20 by rotating the clamping unit 21 and the suction unit 22 with respect to the base plate 20.

[0070] According to this configuration, interference between the clamping unit 21 and the suction unit 22 and surrounding obstacles is suppressed, so that it is possible to realize a robot hand 11 that is capable of achieving a wider range of motion.

[0071] Furthermore, as shown in FIG. 5, the first rotation axis AX1 when the units are switched and the second rotation axis AX2 when the posture of the clamping unit 21 is changed are disposed on a common axis in the longitudinal direction of the robot hand 11.

[0072] That is, in the robot hand of the comparative example, three rotation axes for realizing the three operations of unit switching, changing the posture of the clamping unit, and changing the posture of the suction unit are arranged at three locations in the length direction of the robot hand. In contrast, in the robot hand 11 of this embodiment, three rotation axes AX1, AX2, and AX3 for realizing the three operations of unit switching, changing the posture of the clamping unit, and changing the posture of the suction unit are arranged at two locations in the length direction of the robot hand 11, as shown in FIG.

[0073] As a result, in the case of this embodiment, the length of the robot hand 11 is the sum of the distance from the first rotation axis AX1 and the second rotation axis AX2 to the third rotation axis AX3, the distance from the first rotation axis AX1 and the second rotation axis AX2 to the tip of the clamping unit 21, and the distance from the third rotation axis AX3 to the tip of the suction unit 22. In this way, the length of the robot hand 11 of this embodiment can be made shorter than the length of the robot hand of the comparative example.

[0074] According to the configuration of this embodiment, the length of the robot hand 11 can be shortened, thereby reducing the risk of interference with obstacles when the robot hand 11 is moved. Furthermore, according to the configuration of this embodiment, the movable range of the robot hand 11 can be made wider than the movable range of the robot hand of the comparative example. Furthermore, according to the configuration of this embodiment, there is no need to simplify the configuration of each unit when miniaturizing the robot hand 11, so the functions of the clamping unit 21 and the suction unit 22 can be fully exerted.

[0075] In addition, the robot hand 11 of this embodiment rotates the clamping portion 28 and the suction portion 31 integrally with respect to the base plate 20 while facing in different directions, and holds the object to be held with either the clamping unit 21 or the suction unit 22. According to this configuration, it is possible to smoothly switch between the clamping unit 21 and the suction unit 22 to hold the object to be held.

[0076] When the rotation axis when switching units and the rotation axis when changing the posture of one of the two units are arranged on a common axis, instead of the configuration of this embodiment, it is also possible to arrange the first rotation axis when switching units and the third rotation axis when changing the posture of the suction portion on a common axis.

[0077] The robot hand 11 of this embodiment employs an opening / closing structure of the clamping claws 29 using a parallel link 59 as the clamping unit 21. Therefore, the distance from the second rotation axis AX2 to the tip of the clamping unit 21 when the posture of the clamping unit 21 is changed is longer than the distance from the third rotation axis AX3 to the tip of the suction unit 31 when the posture of the suction unit 31 is changed. As a result, when the first rotation axis AX1 and the second rotation axis AX2 are arranged on a common axis as in this embodiment, the effect of being able to shorten the length of the robot hand 11 is greater than when the first rotation axis AX1 and the third rotation axis AX3 are arranged on a common axis.

[0078] The robot hand 11 of this embodiment is equipped with an suction unit posture correction mechanism 24 that rotates the suction unit 22 in a direction that offsets the posture change of the suction unit 22 that accompanies the posture change of the clamping unit 21 when the posture of the clamping unit 21 is changed, thereby correcting the posture of the suction unit 22. According to this configuration, when changing the attitude of the clamping unit 21, it is possible to suppress a change in the attitude of the suction unit 22 in conjunction with the change in the attitude of the clamping unit 21. As a result, when the clamping unit 21 is used with its attitude tilted, it is possible to suppress the attitude of the suction unit 22 from changing and interfering with an obstacle.

[0079] In the robot hand 11 of this embodiment, the clamping unit 21 and the suction unit 22 are arranged on the first surface 20a of the base plate 20 so as to overlap each other. In this way, the configuration in which the clamping unit 21 and the suction unit 22 are supported by the base plate 20 with a cantilever structure allows the thickness of the robot hand 11 to be thin. Also, the projected area of ​​the robot hand 11 as viewed from the longitudinal direction (Z-axis direction) of the robot hand 11 can be reduced. This reduces the interference of the robot hand 11 with obstacles and increases the range of movement. Another advantage of the cantilever structure is that, for example, when the robot hand 11 goes to pick up an item placed in the corner of a box, the robot hand 11 can be moved with the side opposite to the side where the base plate 20 is provided, that is, the clamping unit 21 side, facing the inner surface of the box. This makes it difficult for the base plate 20 to interfere with the inner surface of the box, and allows the object P to be held to be held efficiently.

[0080] In the robot hand 11 of this embodiment, when the clamping portion 28 and the suction portion 31 are in a position facing in directions that are 180 degrees different from each other, the first holding center line H1 of the clamping unit 21 and the second holding center line H2 of the suction unit 22 are arranged on the same straight line. According to this configuration, regardless of whether the clamping unit 21 or the suction unit 22 is used, a common coordinate system can be used for controlling the position of the clamping claws 29 or the suction pad 32. This reduces the burden on the control unit 13 involved in controlling the position of the clamping claws 29 or the suction pad 32.

[0081] Furthermore, the clamping unit 28 and the suction unit 31 are arranged on the same straight line, and even if the clamping unit 28 and the suction unit 31 are rotated 180 degrees to switch functions, the tip position of one hand (e.g., the clamping unit 28) located before the rotation and the tip position of the other hand (e.g., the suction unit 31) located after the rotation are the same. That is, the clamping unit 28 and the suction unit 31 are positioned point-symmetrically to each other. For example, if the total length of the hand is 500 mm and the first rotation axis AX1 at the time of unit switching is located 250 mm from the tip of one hand, even if the clamping unit 28 and the suction unit 31 are rotated 180 degrees, the tip position of the clamping claw 29 or the tip position of the suction pad 32 is always located 500 mm ahead as viewed from the connection position between the arm 12 and the robot hand 11. With this configuration, the position of the tip of the robot hand 11 seen from the arm 12 is the same whether it is clamping or suction, so the system can perform calculations for position control without being aware of which function it is currently using. This reduces the load on the control unit 13.

[0082] The robot hand 11 of the present embodiment further includes a suction position changing mechanism 25 that changes the position of the suction part 31 in the suction unit 22 by rotating the suction part 31. According to this configuration, when using the suction unit 22, the suction pad 32 can be placed directly opposite one side of the object to be held P placed in various postures and positions, and the object to be held P can be securely held.

[0083] In the robot hand 11 of this embodiment, the suction unit 22 is disposed facing the first surface 20a of the base plate 20. The negative pressure supply pipe 50 for supplying negative pressure to the suction pad 32 is disposed facing the second surface 20b of the base plate 20, and is connected to an inlet 79 provided in a region of the suction unit 22 that is exposed to the outside through the cutout portion 20k of the base plate 20. Furthermore, the negative pressure supply pipe 50 is disposed so as to wind from the inlet 79 side to the suction pad 32 side in a direction opposite to the direction in which the suction unit 22 rotates. According to this configuration, when the suction unit 22 rotates along the first surface 20a of the base plate 20, the negative pressure supply piping 50 is less likely to be pinched between the suction unit 22 and the base plate 20 or to be damaged by being pulled with excessive force as the suction unit 22 rotates, thereby improving the reliability of the negative pressure supply piping 50.

[0084] In the robot hand 11 of this embodiment, the relay pipe 74 for transferring negative pressure to the suction pad 32 is arranged in a spiral shape in the space between the pipe joint 73 and the suction pad 32 . Suppose that the relay pipe 74 is arranged linearly in the space between the pipe joint 73 and the suction pad 32. In this case, there is a risk that the relay pipe 74 will buckle when the posture of the suction part 31 changes. In contrast, in the case of this embodiment, the relay pipe 74 is wound in a spiral shape, so that when the posture of the suction part 31 changes, the relay pipe 74 will deform within its deformable range in accordance with the posture change of the suction part 31. This makes it possible to suppress buckling of the relay pipe 74.

[0085] The picking robot 10 of this embodiment is equipped with a robot hand 11 that provides the above-mentioned effects. According to this configuration, the picking robot 10 can hold a variety of holding objects P placed in various postures and situations, for example, in a box at the transfer source S1, and efficiently transport them to the transfer destination S2.

[0086] The robot hand 11 of the above embodiment includes a parallel link type clamping unit 21 having a pair of parallel links 59, and two clamping jaws 29 each moving up and down to open and close. Instead of this configuration, the robot hand of the embodiment may include a parallel gripper type clamping unit in which two clamping jaws move only in the horizontal direction. In this case, contrary to the above embodiment, the distance from the third rotation axis to the tip of the suction unit when the posture of the suction unit is changed may be longer than the distance from the second rotation axis to the tip of the clamping unit when the posture of the clamping unit is changed. In this case, a configuration may be adopted in which the first rotation axis when the unit is switched and the third rotation axis when the posture of the suction unit is changed are arranged on a common axis.

[0087] In the above embodiment, an example of a robot hand that combines two holding functions, namely, clamping and suction, a so-called hybrid hand type robot hand is given. Instead of this configuration, the present invention may be applied to a robot hand that includes multiple holding units with the same function, such as clamping only or suction only.

[0088] According to at least one embodiment described above, the robot hand 11 has a clamping unit 21, a suction unit 22, and a control unit 13. The clamping unit 21 is rotatably supported on the base plate 20. The clamping unit 21 has a clamping portion 28 that holds the object to be held P. The suction unit 22 is rotatably supported on the base plate 20 independently of the clamping unit 21. The suction unit 22 has a suction portion 31 that holds the object to be held P. The controller controls the operation of the clamping unit 21 and the suction unit 22. The control unit 13 switches which of the clamping unit 21 and the suction unit 22 is used to hold the object to be held P by rotating the clamping unit 21 and the suction unit 22 with the clamping portion 28 and the suction portion 31 facing in different directions, and controls at least one of the clamping unit 21 and the suction unit 22 to change its attitude relative to the base plate 20 by rotating the clamping unit 21 and the suction unit 22 relative to the base plate 20. This makes it possible to realize a robot hand 11 that can suppress interference between the clamping unit 21 and the suction unit 22 and surrounding obstacles and has a wider range of motion.

[0089] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and gist of the invention. [Explanation of symbols]

[0090] 10...picking robot (transport device), 11...robot hand (holding device), 12...arm, 13...control unit, 20...base plate (support member), 20a...first surface, 20b...second surface, 21...clamping unit (first holding unit), 22...suction unit (second holding unit), 23...unit switching and clamping posture change mechanism (first rotation drive mechanism), 24...suction unit posture correction mechanism (second rotation drive mechanism), 25...suction posture change mechanism (third rotation drive mechanism), 28...clamping section (first holding section), 29...clamping claws, 31...suction section (second holding section), 32...suction pad, 50...negative pressure supply piping, 73...piping joint, 74...relay piping, 79...inlet, AX1...first rotation axis, AX2...second rotation axis, H1...first holding center line, H2...second holding center line, P...held object.

Claims

1. A support member; A first holding unit is rotatably supported by the support member and has a first holding part that holds a holding object; a second holding unit supported by the support member so as to be able to rotate independently of the rotation of the first holding unit, the second holding unit having a second holding part that holds a holding object; A control unit that controls operations of the first holding unit and the second holding unit; Equipped with The control unit rotates the first holding unit and the second holding unit integrally around a rotation axis that passes between the first holding unit and the second holding unit, within a plane that includes the first holding unit and the second holding unit and intersects with the rotation axis, while the first holding unit and the second holding unit are facing in a direction away from each other, thereby switching which of the first holding unit and the second holding unit is used to hold the object to be held, and controls at least one of the first holding unit and the second holding unit to change their posture relative to the support member by rotating relative to the support member.

2. The first holding unit is adapted to rotate in one direction relative to the support member, The holding device according to claim 1 , wherein the second holding unit operates to rotate in a direction opposite to the one direction, independently of an operation of the first holding unit.

3. A support member; A first holding unit is rotatably supported by the support member and has a first holding part that holds a holding object; a second holding unit supported by the support member so as to be rotatable independently of the first holding unit and having a second holding portion for holding an object to be held; A control unit that controls operations of the first holding unit and the second holding unit; Equipped with the control unit controls the first holding unit and the second holding unit to be rotated while the first holding unit and the second holding unit are facing in different directions, thereby switching between the first holding unit and the second holding unit to be used to hold the object to be held, and controls the first holding unit and the second holding unit to be rotated relative to the support member to change their attitude relative to the support member; The holding device further includes a second rotation drive mechanism that corrects the posture of the second holding unit by rotating the second holding unit relative to the support member in a direction that offsets a posture change of the second holding unit accompanying the posture change of the first holding unit when rotating the first holding unit to change the posture of the first holding unit.

4. 4. The holding device according to claim 1, wherein the first holding unit and the second holding unit are switched by a first rotation drive mechanism so that either one holds the object to be held, and a first rotation axis of the first rotation drive mechanism and a second rotation axis when the posture of the first holding unit is changed are arranged on a common axis.

5. 5. The holding device according to claim 1, wherein the first holding portion and the second holding portion are rotated integrally relative to the support member while facing in different directions from each other, and an object to be held is held by either the first holding unit or the second holding unit.

6. A holding device as described in claim 1, claim 2, claim 4 citing claim 1 or claim 2, claim 5 citing claim 1 or claim 2, or claim 4 citing claim 1 or claim 2, further comprising a second rotation drive mechanism that corrects the posture of the second holding unit by rotating the second holding unit relative to the support member in a direction that offsets the posture change of the second holding unit accompanying the posture change of the first holding unit when rotating the first holding unit to change the posture of the first holding unit.

7. The holding device according to claim 4 , wherein a distance from the first axis of rotation to a tip of the first holding portion is longer than a distance from the second axis of rotation to a tip of the second holding portion.

8. The support member has a first surface and a second surface opposite to the first surface, the first holding unit and the second holding unit are disposed opposite to the first surface of the support member, A holding device according to any one of claims 1 to 7, wherein at least a portion of the support member, at least a portion of the first holding unit, and at least a portion of the second holding unit are arranged to overlap each other when viewed from a normal direction of the first surface.

9. The holding device described in claim 8, wherein when the first holding portion and the second holding portion are oriented in directions that differ by 180° from each other in a plane parallel to the first surface, a first holding center line of the first holding unit and a second holding center line of the second holding unit are arranged within a range that is on the same straight line.

10. The holding device according to claim 9 , wherein the first holding portion and the second holding portion are positioned point-symmetrically to each other.

11. The holding device according to claim 1 , further comprising a third rotation drive mechanism configured to change a posture of the second holding portion in the second holding unit by rotating the second holding portion.

12. the first holding unit is a clamping unit having a plurality of clamping claws and configured to hold an article in a clamped state by the plurality of clamping claws, The holding device according to claim 1 , wherein the second holding unit is a suction unit having a suction pad and holding an article by suction with the suction pad under negative pressure.

13. The support member has a first surface and a second surface opposite to the first surface, The suction unit is disposed opposite the first surface of the support member, the clamping unit is disposed on an opposite side to a side on which the support member is located with respect to the suction unit, 13. The holding device according to claim 12, wherein a negative pressure supply pipe that transports negative pressure to the suction pad is arranged opposite the second surface of the support member and is connected to an opening provided in a region of the suction unit that is exposed from the support member.

14. The holding device according to claim 13 , wherein the negative pressure supply pipe is arranged to be wound around from the opening to the suction pad in a direction opposite to a direction in which the suction unit rotates.

15. the suction unit includes a suction unit base material, a pipe joint provided on the suction unit base material and communicating with the negative pressure supply pipe, and a relay pipe connecting the pipe joint and the suction pad, The holding device according to claim 14 , wherein at least a portion of the relay pipe is arranged in a spiral shape in the space between the pipe joint and the suction pad.

16. A holding device according to any one of claims 1 to 15, An arm configured to be controlled by a control unit and moving the holding device; A conveying device comprising:

Images