Patent Publication Number: US-2021187727-A1

Title: Robot hand, robot and robot system

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     The present application claims priority to PCT/JP2019/032330 filed Aug. 19, 2019, which claims priority to JP 2018-156231 filed Aug. 23, 2018, the entire contents of each are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a robot hand, a robot, and a robot system. 
     BACKGROUND ART 
     A load handling device is provided with a movable conveyor and a take-out arm. The movable conveyor advances so as to approach a load, and a gripping part provided at an end of the take-out arm grips the load. After the take-out arm places the load on the movable conveyor, it changes its posture to a load-avoiding posture. Then, the movable conveyor descends to the height of a conveying bench, and a belt constituting a transferring surface of the conveyor rotates so as to place the load onto the conveying bench. 
     DESCRIPTION OF THE DISCLOSURE 
     Summary of the Disclosure 
     A robot hand according to one aspect of the present disclosure includes a base attached to an end of a robotic arm, a conveyor fixed to the base, and a holder to hold a workpiece and place the workpiece on a transferring surface of the conveyor. 
     The holder may include a pivot shaft extending along the conveyor in a transferring direction of the conveyor, and reciprocatable or telescopic in the transferring direction, a pivoting structure attached to the pivot shaft so as to be reciprocatable in the transferring direction, and pivotable centering on the pivot shaft in a plane in which a width direction perpendicular to the transferring direction intersects with a height direction perpendicular to the transferring direction and the width direction, and a holding structure upstream of the pivoting structure in the transferring direction to hold the workpiece. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic view illustrating a state in which a robot system according to one embodiment of the present disclosure is used to transfer a cardboard box. 
         FIG. 2  is a block diagram illustrating the entire configuration of the robot system according to the embodiment of the present disclosure. 
         FIGS. 3(A) and 3(B)  are side views of a robot according to the embodiment of the present disclosure, where  FIG. 3(A)  is a view when a pivoting part is advanced, and  FIG. 3(B)  is a view when the pivoting part is retreated. 
         FIGS. 4(A) and 4(B)  are front views of a robot hand according to the embodiment of the present disclosure, where  FIG. 4(A)  is a view when the pivoting part is in a workpiece-holding posture, and  FIG. 4(B)  is a view when the pivoting part is in a workpiece-avoiding posture. 
     
    
    
     MODE FOR CARRYING OUT THE DISCLOSURE 
     Hereinafter, a robot hand, a robot, and a robot system according to one embodiment of the present disclosure are described with reference to the accompanying drawings. Note that the present disclosure is not limited to this embodiment. Moreover, below, the same reference characters are given to the same or corresponding components throughout the drawings to omit redundant description. 
     Robot System  10   
       FIG. 1  is a schematic view illustrating a state in which a robot system according to this embodiment is used to transfer a cardboard box.  FIG. 2  is a block diagram illustrating the entire configuration of the robot system. As illustrated in  FIG. 1 , a robot system  10  according to this embodiment transfers a cardboard box W (a workpiece) which is sealed while packing an object therein. In detail, the robot system  10  transfers a plurality of piled cardboard boxes W one by one to a stationary-type conveyor C. 
     As illustrated in  FIGS. 1 and 2 , the robot system  10  is provided with a robot  20 , and a user interface  110  which remotely operates the robot  20 . The robot system  10  further includes an imaging device  112  which images a working state of the robot  20 , and an output device  114  which outputs the imaged information of the imaging device  112 . The robot system  10  is further provided with an AGV (Automated Guided Vehicle)  120  to which a base end of a robotic arm  30  is fixed. 
     Robot  20   
     As illustrated in  FIGS. 1 and 2 , the robot  20  is provided with the robotic arm  30 , a robot hand  50  attached to an end of the robotic arm  30 , and a robot controller  90  which controls operations of the robotic arm  30  and the robot hand  50 . The robot  20  is a vertically articulated robot. 
     Robotic Arm  30   
       FIGS. 3(A) and 3(B)  are side views of the robot according to this embodiment.  FIG. 3(A)  is a view when a pivoting part is advanced, and  FIG. 3(B)  is a view when the pivoting part is retreated. As illustrated in  FIGS. 3(A) and 3(B) , the robotic arm  30  is an articulated arm having six joint axes (shafts) JT 1 -JT 6 , and six links  33   a - 33   f  serially coupled to each other via the corresponding joint axes. 
     A coupled structure of the links and the joint axes, comprised of the first joint axis JT 1 , the first link  33   a , the second joint axis JT 2 , the second link  33   b , the third joint axis JT 3 , and the third link  33   c , constitutes a first arm part  31 . In detail, the first joint axis JT 1  couples an upper surface of the AGV  120  to a base-end part of the first link  33   a  so as to be rotatable about a vertical axis. The second joint axis JT 2  couples an end part of the first link  33   a  to a base-end part of the second link  33   b  so as to be rotatable about a horizontal axis. The third joint axis JT 3  couples an end part of the second link  33   b  to a base-end part of the third link  33   c  so as to be rotatable about a horizontal axis. 
     A coupled structure of the links and the joint axes, comprised of the fourth joint axis JT 4 , the fourth link  33   d , the fifth joint axis JT 5 , the fifth link  33   e , the sixth joint axis JT 6 , and the sixth link  33   f , constitutes a second arm part  32 . In detail, the fourth joint axis JT 4  couples an end part of the third link  33   c  to a base-end part of the fourth link  33   d  so as to be rotatable about an axis extending in a longitudinal direction of the third link  33   c . The fifth joint axis JT 5  couples an end part of the fourth link  33   d  to a base-end part of the fifth link  33   e  so as to be rotatable about an axis extending perpendicularly to a longitudinal direction of the fourth link  33   d . The sixth joint axis JT 6  couples an end part of the fifth link  33   e  to a base-end part of the sixth link  33   f  so as to be rotatable in a twisted manner. Then, the robot hand  50  is attached to an end part of the sixth link  33   f.    
     Robot Hand  50   
       FIGS. 4(A) and 4(B)  are front views of the robot hand according to this embodiment.  FIG. 4(A)  is a view when the pivoting part is in a workpiece-holding posture, and  FIG. 4(B)  is a view when the pivoting part is in a workpiece-avoiding posture. As illustrated in  FIGS. 3(A), 3(B), 4(A) and 4(B) , the robot hand  50  is provided with a base  52  attached to the end of the robotic arm  30 , a conveyor  60  fixed to the base  52 , and a holding mechanism  70  which holds the cardboard box W and places it on a transferring surface  68  of the conveyor  60 . 
     Base  52   
     As illustrated in  FIGS. 3(A), 3(B), 4(A) and 4(B) , the base  52  has a bottom plate  54  in a rectangular shape when seen in its thickness direction, a side plate  56   a  standing from one end edge of the bottom plate  54  in its width direction, and a side plate  56   b  standing from the other end edge of the bottom plate  54 . Each of the side plates  56   a  and  56   b  has a rectangular shape when seen in its thickness direction, and has the same shape as each other. 
     Conveyor  60   
     As illustrated in  FIGS. 3(A) and 3(B) , the conveyor  60  is a belt conveyor. The conveyor  60  includes a plurality of rollers  62  disposed in parallel to each other in a transferring direction, a pair of shafts  64   a  and  64   b  which support rotational shafts of the plurality of rollers  62 , a ring-shaped transferring belt  66  wound around the plurality of rollers  62 , and an electric motor which rotary drives at least one of the plurality of rollers  62 . 
     Holding Mechanism  70   
     As illustrated in  FIGS. 3(A), 3(B), 4(A) and 4(B) , the holding mechanism or holder  70  has a pivot shaft  72  extending in the transferring direction of the conveyor  60  along the conveyor  60 , a pivoting part  80  attached to the pivot shaft  72 , and four suction parts  86  (a holding part) provided upstream of the pivoting part  80  in the transferring direction (i.e., the transferring direction of the conveyor  60 ) so as to suck and hold the cardboard box W. 
     As illustrated in  FIGS. 3(A) and 3(B) , the pivot shaft  72  is provided along an edge part of the conveyor  60  in the width direction, and is expandable and contractible in the transferring direction. In detail, the pivot shaft  72  is configured as a piston which projects toward upstream in the transferring direction from inside a cylinder  74  in a rectangular-parallelepiped shape. The cylinder  74  is provided along the edge part of the conveyor  60  in the width direction. That is, although, in appearance of the robot  20 , a part of the pivot shaft  72  projecting from the cylinder  74  toward upstream in the transferring direction (i.e., a visible part from outside) is telescopic in the transferring direction, the pivot shaft  72  is actually reciprocatable in the transferring direction. 
     The pivoting part  80  is formed in a plate-like shape, and is attached to the pivot shaft  72  so that a thickness direction of the pivoting part  80  corresponds to the transferring direction. In detail, the pivoting part  80  is attached to the end of the pivot shaft  72  at a base-end part of a principal surface of the pivoting part  80  located downstream in the transferring direction. Both principal surfaces of the pivoting part  80  have longitudinal dimensions. 
     As illustrated in  FIGS. 3(A) and 3(B) , the pivoting part  80  is reciprocatable in the transferring direction by being attached to the pivot shaft  72 . In detail, the pivoting part  80  is reciprocatable in the transferring direction between a position further upstream of an upstream end of the conveyor  60  and an intermediate part of the conveyor  60  in the transferring direction. 
     As illustrated in  FIGS. 4(A) and 4(B) , by the pivoting part  80  being attached to the pivot shaft  72 , it is pivotable in a plane in which the width direction perpendicular to the transferring direction intersects with a height direction perpendicular to the transferring direction and the width direction. In detail, the pivoting part  80  is pivotable centering on the pivot shaft  72  within a range from a workpiece-transferring posture where the pivoting part  80  extends in the width direction of the conveyor  60 , to the workpiece-avoiding posture where it extends in the height direction of the conveyor  60  (i.e., within the rotational angle of 90°). 
     As illustrated in  FIGS. 3(A), 3(B), 4(A) and 4(B) , each of the four suction parts  86  is formed in a hollow tapered shape, and the tapered end is attached to the pivoting part  80 . In detail, as illustrated in  FIGS. 4(A) and 4(B) , the four suction parts  86  are arranged to be 2×2 in row and column, and attached to the upstream principal surface of the pivoting part  80  in the transferring direction. The four suction parts  86  are each connected to a vacuum generator, and thus, the pressure inside the suction part  86  becomes negative. The four suction parts  86  suck a side surface of the cardboard box W by the negative pressure so as to cooperatively hold one cardboard box W. 
     Robot Controller  90   
     As illustrated in  FIG. 2 , the robot controller  90  controls the operations of the robotic arm  30 , the conveyor  60 , and the holding mechanism  70  according to operational information from the user interface  110  based on a program stored in advance in a storage device. A concrete configuration of the robot controller  90  is not particularly limited, and it may be implemented, for example, by a known processor (e.g., a CPU) operating based on the program stored in the storage device (e.g., a memory). 
     User Interface  110   
     As illustrated in  FIG. 1 , the user interface  110  is disposed to be separated from the robot  20  and the AGV  120  by given distances in order to remotely operate the robot  20  and the AGV  120  based on a command value manually inputted by an operator P. 
     A concrete configuration of the user interface  110  is not particularly limited, and it may accept a displacement of a control handle or pressing of a button as the command value, or the user interface  110  may be configured as a touch-panel screen which accepts pressing or touching of a screen display as the command value. Alternatively, the user interface  110  may accept voice as the command value using a microphone, or may have other configurations. 
     The user interface  110  generates the operational information by accepting the command value manually inputted by the operator P, and transmits the operational information to the robot controller  90  and an AGV controller  128 . 
     Imaging Device  112   
     The imaging device  112  is provided in order to image the working state of the robot  20  and the AGV  120  so as to acquire video information. A concrete configuration of the imaging device  112  is not particularly limited, and it may be configured as any type of known or desired video camera. 
     Output Device  114   
     The output device  114  is a displaying device which outputs the video information captured by the imaging device  112 . A concrete configuration of the output device  114  is not particularly limited, and it may be a Liquid Crystal Display, an Organic Electro-Luminescence Display, or other devices. 
     AGV  120   
     The AGV (Automated Guided Vehicle)  120  has a vehicle body  122  formed in a plate-like shape and to which the base end of the robotic arm  30  is fixed on its upper surface, a plurality of wheels  124  attached to a bottom surface of the vehicle body  122 , and the AGV controller  128  which controls the operation of the AGV  120 . 
     The AGV controller  128  controls the operation of the AGV  120  according to, for example, the operational information from the user interface  110  based on a program stored in advance in a storage device. A concrete configuration of the AGV controller  128  is not particularly limited, and it may be implemented by a known processor (e.g., a CPU) operating based on the program stored in the storage device (e.g., a memory). 
     Note that the AGV controller  128  may detect weak induced current from electric wiring buried underground of a work site, and control the operation of the AGV  120  based on the detected value. In this case, the operational information may be received from the user interface  110  as needed. 
     EXAMPLE OF TRANSFERRING WORK 
     One example of the transferring work executed by the robot system  10  according to this embodiment is described. Here, the robot system  10  is used to transfer the plurality of piled cardboard boxes W one by one to the stationary-type conveyor C. Note that, in the following example of the transferring work, the operator P may input the command value to the user interface  110  while grasping the working state of the robot  20  and the AGV  120  based on the video information outputted through the output device  114 . Here, the video information outputted from the output device  114  is images of the working state of the robot  20  and the AGV  120  captured by the imaging device  112 . 
     First, the operator P operates the user interface  110  to stop the transferring belt  66  of the conveyor  60 . Moreover, as illustrated in  FIG. 3(A) , the pivot shaft  72  is extended so that the pivoting part  80  is located further upstream of the upstream end of the conveyor  60 . Moreover, as illustrated in  FIG. 4(A) , the operator P operates the user interface  110  to rotate the pivot shaft  72  so that the pivoting part  80  is pivoted to take the workpiece-holding posture. 
     Next, the operator P operates the user interface  110  to manipulate the AGV  120  so that the robot  20  (and the AGV  120 ) approaches the plurality of piled cardboard boxes W to be transferred. 
     Moreover, the operator P operates the user interface  110  to change the posture of the robotic arm  30  so that the four suction parts  86  provided on the upstream principal surface of the pivoting part  80  contact a side surface of one of the cardboard boxes W, which is located at the top of the plurality of cardboard boxes W (hereinafter, simply referred to as a “top cardboard box W”). At this time, the operator P operates the user interface  110  to adjust the posture of the robotic arm  30  so that an upstream end of the transferring surface of the conveyor  60  extends in parallel to a lower end edge of the side surface of the top cardboard box W, near and below the lower end edge. 
     Then, the operator P operates the user interface  110  to drive the vacuum generator so as to make inside the four suction parts  86  negative pressure. Therefore, the suction parts  86  suck the side surface of the top cardboard box W to hold it. 
     Next, as illustrated in  FIG. 3(B) , the operator P operates the user interface  110  to contract the pivot shaft  72  so that the pivoting part  80  pivots to the intermediate position of the conveyor  60  in the transferring direction. Therefore, the cardboard box W held by the suction parts  86  is pulled and placed on the transferring surface  68 . 
     Moreover, the operator P operates the user interface  110  to change the posture of the robotic arm  30  so that the transferring surface  68  of the conveyor  60  continues to upstream of a transferring surface of the stationary-type conveyor C. At this time, the posture of the robotic arm  30  is adjusted so that a downstream end edge of the transferring surface of the conveyor  60  approaches above an upstream-end part of the transferring surface of the stationary-type conveyor C, and width directions of both transferring surfaces become parallel to each other. 
     When the distance between the plurality of piled cardboard boxes W and the stationary-type conveyor C is larger than a movable range of the end of the robotic arm  30 , the operator P may operate the user interface  110  to move the AGV  120  in addition to changing the posture of the robotic arm  30 . 
     Moreover, the operator P operates the user interface  110  to stop the vacuum generator so as to release the top cardboard box W from the state sucked by the suction parts  86 . 
     Then, as illustrated in  FIG. 4(B) , the operator P operates the user interface  110  to rotate the pivot shaft  72  so that the pivoting part  80  is pivoted to take the workpiece-avoiding posture. 
     Finally, the operator P operates the user interface  110  to drive the transferring belt  66  of the conveyor  60 . Accordingly, the cardboard box W placed on the transferring surface  68  of the conveyor  60  is moved downstream on the transferring surface  68 , and is transferred from a downstream end of the transferring surface  68  to the upstream-end part of the transferring surface of the stationary-type conveyor C. 
     By repeating the transferring work described above, the robot system  10  can transfer all of the plurality of piled cardboard boxes W to the transferring surface of the stationary-type conveyor C. Note that the stationary-type conveyor C may be a belt conveyor similarly to the conveyor  60 . The belt conveyor may have a known structure. When the stationary-type conveyor C receives the cardboard box W from the conveyor  60  at its upstream part, it further transfers the cardboard box W to a desired destination. 
     The functionality of the elements including CPUs disclosed herein may be implemented using circuitry or processing circuitry which includes general purpose processors, special purpose processors, integrated circuits, ASICs (“Application Specific Integrated Circuits”), conventional circuitry and/or combinations thereof which are configured or programmed to perform the disclosed functionality. Processors are considered processing circuitry or circuitry as they include transistors and other circuitry therein. The processor may be a programmed processor which executes a program stored in a memory. In the disclosure, the circuitry, units, or means are hardware that carry out or are programmed to perform the recited functionality. The hardware may be any hardware disclosed herein or otherwise known which is programmed or configured to carry out the recited functionality. When the hardware is a processor which may be considered a type of circuitry, the circuitry, means, or units are a combination of hardware and software, the software being used to configure the hardware and/or processor. 
     Effects 
     According to the robot hand  50  of this embodiment, since the conveyor  60  is fixed to the end of the robotic arm  30 , the conveyor  60  can be moved within the movable range of the end of the robotic arm  30 . As a result, the robot hand  50  capable of transferring the cardboard box W (the workpiece) by the movable conveyor  60  while the installing location will not be limited, can be provided. 
     According to the robot hand  50  of this embodiment, since the pivoting part  80  is reciprocatable in the transferring direction of the conveyor  60 , the suction parts  86  provided to the pivoting part  80  can pull and place the cardboard box W onto the transferring surface  68  of the conveyor  69  while holding the cardboard box W. Moreover, since the pivoting part  80  is pivotable centering on the pivot shaft  72  in the plane in which the width direction of the conveyor  60  intersects with the height direction, the pivoting part  80  can pivot to take the workpiece-avoiding posture after the cardboard box W is placed on the transferring surface  68  of the conveyor  60  (i.e., the pivoting part  80  can pivot to the position where it does not hinder the transference of the cardboard box W on the conveyor  60 ). Therefore, the holding mechanism  70  with a simple configuration can hold the cardboard box W and place it on the transferring surface  68  of the conveyor  60 . 
     In this embodiment, the pivoting part  80  has a plate-like shape and is attached to the pivot shaft  72  so that the thickness direction of the pivoting part  80  corresponds to the transferring direction of the conveyor  60 . Moreover, the suction parts  86  are attached to the upstream principal surface of the pivoting part  80  in the transferring direction. Therefore, the configuration of the holding mechanism  70  can be further simplified. 
     In this embodiment, the pivot shaft  72  is provided along the edge part of the conveyor  60  in the width direction. Therefore, the entire structure of the robot hand  50  can be downsized. Moreover, the pivoting part  80  can easily take the workpiece-avoiding posture by pivoting after the cardboard box W is placed on the transferring surface  68  of the conveyor  60 . 
     In this embodiment, the holding part is configured as the suction parts  86 . Therefore, for example, even when holding one cardboard box W from the plurality of cardboard boxes W piled up without gaps therebetween, a side surface of the one cardboard box W can be sucked so that the one cardboard box W is easily held without interference of the other cardboard boxes W. 
     Since the robot  20  according to this embodiment has the robot hand  50  as described above, effects similar to the robot hand  50  can be achieved. 
     Since the robot  20  according to this embodiment is the vertically articulated robot, the robotic arm  30  can easily take a desired posture. As a result, the effects achieved by the present disclosure can be remarkable. 
     Since the robot  20  according to this embodiment has the six joint axes, the robotic arm  30  can easily take a desired posture. As a result, the effects achieved by the present disclosure can be remarkable. 
     The robot system  10  according to this embodiment uses the user interface  110  to remotely operate the robot  20  having the robot hand  50  and the robotic arm  30 . 
     As a result, the robot system  10  capable of transferring the cardboard box W by the movable conveyor while the installing location will further be unlimited, can be provided. 
     The robot system  10  according to this embodiment is further provided with the imaging device  112  which images the working state of the robot  20 , and the output device  114  which outputs the video information captured by the imaging device  112 . Therefore, the operator P can input the command value to the user interface  110  while accurately grasping the working state of the robot  20  based on the video information outputted from the output device  114 . 
     The robot system  10  according to this embodiment is further provided with the AGV (Automated Guided Vehicle)  120  to which the base end of the robotic arm  30  is fixed. Therefore, even when the distance between the plurality of piled cardboard boxes W and the stationary-type conveyor C is larger than the movable range of the end of the robotic arm  30 , the transferring work can be smoothly performed. That is, since the installing location will further be unlimited, the effects achieved by the present disclosure can be remarkable. 
     MODIFICATIONS 
     It is apparent for a person skilled in the art that many improvements and other embodiments of the present disclosure are possible from the above description. Therefore, the above description is to be interpreted only as illustration, and it is provided in order to teach a person skilled in the art the best mode for implementing the present disclosure. The details of the structures and/or the functions may be substantially changed, without departing from the spirit of the present disclosure. 
     Although in the embodiment described above the transferred workpiece is the cardboard box W, it is not limited to this. The workpiece may be another object having a given shape (e.g., a member used for assembling machinery, and packed food), or an object not having a fixed shape, such as a rock and a fried chicken. 
     In the embodiment described above, the transferring belt  66  of the conveyor  60  is started to drive after the cardboard box W is placed on the transferring surface  68  of the conveyor  60 , the posture of the robotic arm  30  is changed so that the transferring surface  68  of the conveyor  60  continues to upstream of the transferring surface of the stationary-type conveyor C, and the pivoting part  80  is changed to the workpiece-avoiding posture. However, it is not limited to this configuration, and the transferring work may be performed while the transferring belt  66  of the conveyor  60  is always driven. Accordingly, the plurality of cardboard boxes W can be transferred one by one in a shorter period of time. 
     In the embodiment described above, as illustrated in the block diagram of  FIG. 2 , the robot system  10  is provided with the robot  20 , the user interface  110 , the imaging device  112 , the output device  114  and the AGV  120 . However, it is not limited to this, and the robot system  10  may further include other configurations. For example, the robot system  10  may further include the stationary-type conveyor C, which is the transferring destination of the cardboard box W in the embodiment described above. In this case, for example, the operator P may operate the user interface  110  to control the operation of the stationary-type conveyor C. 
     Although in the embodiment described above the position of the conveyor  60  is changed only by changing the posture of the robotic arm  30  and moving the AGV  120 , it is not limited to this. For example, the conveyor  60  may be attached to the base  52  so as to be rotatable with respect to the base  52  in a plane in which the transferring direction intersects with the height direction of the conveyor  60 . Alternatively, the base  52  may be provided with a pair of rails, and the conveyor  60  may be attached to the base  52  so as to be movable along the rails. Note that in this case the robot controller  90  may further control the operation of the base  52 . 
     Although in the embodiment described above the holding part is comprised of the four suction parts  86  which suck and hold the cardboard box W (the workpiece), it is not limited to this. For example, the number of the suction parts  86  may be one or more and three or less, or five or more. Moreover, the shape of each of the four suction parts  86  is not limited to the hollow tapered shape, but may be a hollow rectangular parallelepiped shape or a hollow cylindrical shape, or other shapes. Furthermore, the holding part may be a gripping part which grips the workpiece to hold it, a placing part which places the workpiece thereon to hold it, or other configurations. 
     Although in the embodiment described above the conveyor  60  is the belt conveyor, it is not limited to this. For example, the conveyor  60  may be a roller conveyor, or other types of conveyor. 
     In the embodiment described above, the pivot shaft  72  is telescopic in appearance of the robot  20  in the transferring direction of the conveyor  60  while it is actually reciprocatable in the transferring direction using the cylinder  74 . However, it is not limited to this configuration. For example, the pivot shaft  72  may be comprised of a hollow cylindrical member and a cylindrical member coaxially inserted into the hollow cylindrical member so as to be reciprocatable in the axial direction, thus being telescopic in the transferring direction of the conveyor  60 . In this case, a part of the cylindrical member may project from an end of the hollow cylindrical member when the axial shaft  72  contracts to the most, and the pivoting part  80  may be attached to the projecting part. Alternatively, the pivot shaft  72  may be reciprocatable also in appearance of the robot  20  in the transferring direction of the conveyor  60  without using the cylinder  74  (e.g., by being coupled to another member reciprocatable in the transferring direction of the conveyor  60 ). 
     Although in the embodiment described above the pivot shaft  72  is provided along the edge part of the conveyor  60  in the width direction, it is not limited to this. For example, the pivot shaft  72  may be disposed above the conveyor  60  so as to extend in parallel to the transferring surface  68  of the conveyor  60  when seen in the width direction of the conveyor  60 , and extend in the transferring direction along the centerline of the conveyor  60  in the width direction when seen in the height direction from above the conveyor  60 . In this case, the pivoting part  80  may be attached at its base-end part to the pivot shaft  72  so as to be pivotable centering on the pivot shaft  72  in the plane in which the width direction intersects with the height direction. For example, the pivoting part  80  may be pivotable within a range from a workpiece-avoiding posture in which the pivoting part  80  extends toward one side of the conveyor  60  in the width direction, to a workpiece-transferring posture in which it extends in the height direction of the conveyor  60 , and then, to a workpiece-avoiding posture in which it extends toward the other side of the conveyor  60  in the width direction (i.e., within the rotational angle of 180° in the plane). 
     Although in the embodiment described above the robot  20  is the vertically articulated robot, it is not limited to this. For example, the robot  20  may be a polar robot, a cylindrical robot, a Cartesian coordinate robot, a horizontally articulated robot, or other types of robot. 
     Although in the embodiment described above the robotic arm  30  has the six joint axes, it is not limited to this. For example, the robotic arm  30  may have seven or more joint axes. Alternatively, the robotic arm  30  may have one or more and five or less joint axes. 
     Although in the embodiment described above the robot system  10  is provided with the imaging device  112  and the output device  114 , it is not limited to this. For example, the robot system  10  may not be provided with the imaging device  112  and the output device  114 , but the operator P may visually confirm the working state of the robot  20  and the AGV  120 . Accordingly, the configuration of the robot system  10  can be further simplified. 
     Although in the embodiment described above the pivoting part  80  is formed to be a plate-like shape having a rectangular shape when seen in the thickness direction and is attached to the pivot shaft  72  so that the thickness direction corresponds to the transferring direction of the conveyor  60 , and the suction parts  86  are attached to the upstream principal surface of the pivoting part  80  in the transferring direction, it is not limited to this. For example, the pivoting part  80  may have any shape as long as it can pivot while being attached to the pivot shaft  72  so as to take the workpiece-holding posture and the workpiece-avoiding posture, and the suction parts  86  (the holding part) can be attached upstream of the pivoting part  80  in the transferring direction. For example, the pivoting part  80  may be formed in a plate-like shape having a triangular shape, a polygonal shape with more than five sides, or a square shape when seen in the thickness direction. Alternatively, the pivoting part  80  may be formed in a cylindrical shape, a pyramid shape, a cone shape, or other shapes. 
     Although in the embodiment described above the robot system  10  allows the operator P to input the command value using the user interface  110  so as to operate the robot  20  and the AGV  120  based on the command value, it is not limited to this. For example, the robot system  10  may be a fully automatic system without the user interface  110 . 
     In order to implement the robot system  10  as the fully automatic system, the robotic arm  30  may be provided with a proximity sensor at its end, and the robot controller  90  may control the operations of the robotic arm  30  and the robot hand  50  based on a detection value of the proximity sensor, etc. Alternatively, the robotic arm  30  may be provided with a camera at its end, and the robot controller  90  may control the operations of the robotic arm  30  and the robot hand  50  based on an analytical value of the imaged information of the camera, etc. Moreover, weak induced current may be detected from electric wiring buried underground of the work site, and the AGV controller  128  may control the operation of the AGV  120  based on this detection value. 
     According to the disclosure, since the conveyor is fixed to the end of the robotic arm, the conveyor can be moved within a range where the end of the robotic arm is movable. Thus, the robot hand is capable of transferring the workpiece by the movable conveyor while not limiting an installing location. 
     According to the disclosure, since the pivoting part can reciprocate in the transferring direction of the conveyor, the holding part provided to the pivoting part can pull the workpiece to place it on the transferring surface of the conveyor while holding the workpiece. Moreover, since the pivoting part is pivotable centering on the pivot shaft in the plane in which the width direction of the conveyor intersects with the height direction, after the workpiece is placed on the transferring surface of the conveyor, the pivoting part can be pivoted to a position not interfering the transferring of the workpiece on the conveyor. As described above, the holding mechanism with a simple structure can hold the workpiece and place it on the transferring surface of the conveyor. 
     The pivoting part may be formed in a plate-like shape and attached to the pivot shaft so that a thickness direction of the pivoting part corresponds to the transferring direction. The holding part may be attached to a principal surface of the pivoting part located upstream in the transferring direction. 
     According to this structure, the holding mechanism can be further simplified. 
     The pivot shaft may be provided along an edge part of the conveyor in the width direction. 
     According to this structure, the entire structure of the robot hand can be reduced in size. Moreover, after the workpiece is placed on the transferring surface of the conveyor, the pivoting part can be easily pivoted to the position not interfering the transferring of the workpiece on the conveyor. 
     The holding part may be a suction part configured to suck and hold the workpiece. 
     According to this structure, even when, for example, holding one workpiece from a plurality of workpieces piled up without gaps therebetween, a side surface of the one workpiece can be sucked so that the one workpiece is easily held without interference of the other workpieces. 
     For example, the conveyor may be a belt conveyor. 
     According to this structure, by being provided with the robot hand, the conveyor can be moved within the range where the end of the robotic arm is movable. As a result, the robot capable of transferring the workpiece by the movable conveyor while the installing location will not be limited, can be provided. 
     The robot may be a vertically articulated robot. 
     According to this structure, the robotic arm can easily take a desired posture, and as a result, the effects achieved by the present disclosure can be remarkable. 
     The robotic arm may have six or more joint axes. 
     According to this structure, the robotic arm can easily take a desired posture, and as a result, the effects achieved by the present disclosure can be remarkable. 
     According to this structure, by being provided with the robot hand, the conveyor can be moved within the range where the end of the robotic arm is movable. As a result, the robot system capable of transferring the workpiece by the movable conveyor while the installing location will not be limited, can be provided. 
     The robot system may further include a user interface configured to remotely operate the robot. 
     According to this structure, the robot including the robot hand and the robotic arm can be remotely operated by using the user interface. As a result, the robot system capable of transferring the workpiece by the movable conveyor while the installing location will further be unlimited, can be provided. 
     The robot system may further include an imaging device configured to image a working state of the robot, and an output device configured to output the imaged information of the imaging device. 
     According to this structure, the operator can input a command value to the user interface while accurately grasping the working state of the robot based on the information outputted from the output device. 
     The robot system may further include an automated guided vehicle to which a base end of the robotic arm is fixed. 
     According to the present disclosure, a robot hand, a robot, and a robot system capable of transferring a workpiece by a movable conveyor while the installing location will not be limited, can be provided. 
     DESCRIPTION OF REFERENCE CHARACTERS 
       10  Robot System 
       20  Robot 
       30  Robotic Arm 
       31  First Arm Part 
       32  Second Arm Part 
       33  Link 
       50  Robot Hand 
       52  Base 
       54  Bottom Plate 
       56  Side Plate 
       60  Conveyor 
       62  Roller 
       64  Shaft 
       66  Transferring Belt 
       68  Transferring Surface 
       70  Holding Mechanism or Holder 
       72  Pivot Shaft 
       74  Cylinder 
       80  Pivoting Part 
       86  Suction Part 
       90  Robot Controller 
       110  User interface 
       112  Imaging Device 
       114  Output Device 
       120  AGV 
       122  Vehicle Body 
       124  Wheel 
       128  AGV Controller 
     JT Joint Axis 
     C Stationary-type Conveyor 
     P Operator 
     W Cardboard Box