JP2019018304A - Gripping Hand - Google Patents

Abstract

To provide a gripping hand which is hardly influenced by shape and posture of a workpiece when gripping the workpiece.SOLUTION: A gripping hand 30 includes: a movable section 31 which is reciprocated in a first movement direction M1 and a second movement direction M2 by the action of external force; a plurality of arms 32 which have elasticity and extend from the movable section 31; and each support section 33 which limits displacement in the first movement direction M1 of a portion between a base end 321 connected to the movable section 31 and a tip 322 in each arm 32. When the base ends 321 are displaced in the first movement direction M1 together with the movable section 31, the plurality of arms 32 displace from an open position where the tips 322 are separated from each other toward a closed position where the tips 322 approach each other by defining a portion limited in displacement by the support section 33 as a fulcrum.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a gripping hand.

  Patent Document 1 discloses a robot hand that sandwiches an object (workpiece) at an extraction position and conveys the object to a position different from the extraction position. The robot hand includes a first holding unit having a pair of opening and closing units that sandwich and hold the first object, and a pair of opening and closing units that hold a second object different from the first object. 2 clamping parts. In this way, this robot hand can grip different types of objects by using different clamping parts.

JP 2010-23120 A

  However, even if the robot hand as described above can grip the first object and the second object, it may not be able to grip an object having a shape different from that of the first object and the second object. . Further, the robot hand as described above can hold the first object and the second object that do not take a fixed posture even if the first and second objects that take a fixed posture can be gripped. There is a possibility that it cannot be gripped. That is, the robot hand as described above is easily affected by the shape and posture of the workpiece when gripping the workpiece.

  An object of the present invention is to provide a gripping hand that is not easily affected by the shape and posture of a workpiece when the workpiece is gripped.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A gripping hand that solves the above problem includes a movable part that reciprocates in a second movement direction that is opposite to the first movement direction and the first movement direction by the action of an external force, and a plurality of elastic parts that extend from the movable part. And a limiting portion for limiting displacement in the first movement direction of a portion between a base end portion connected to the movable portion and a distal end portion on the opposite side of the arm. When the base end part is displaced in the first movement direction together with the movable part, the tip of the arm from the open position where the tip parts are separated from each other, with a portion where displacement is restricted by the restriction part as a fulcrum. The parts are displaced toward the closed position where they approach each other.

  According to the above configuration, when the gripping hand grips the workpiece, the movable portion is displaced in the first movement direction after the gripping hand is brought close to the workpiece. Then, the plurality of arms of the gripping hand are displaced from the open position to the closed position, and the plurality of arms sandwich the workpiece. Here, since the plurality of arms have elasticity, they are elastically deformed according to the shape and posture of the workpiece. For this reason, it is hard to produce a clearance gap between a some arm and a workpiece | work. Thus, the gripping hand is not easily affected by the shape and posture of the workpiece when gripping the workpiece.

In the gripping hand, when an external force does not act on the movable part, it is preferable that the plurality of arms are arranged at the open position.
According to the above configuration, the plurality of arms are arranged at the open position without applying an external force to the movable part. For this reason, the attitude | position of the several arm arrange | positioned in an open position is stabilized rather than the case where an external force is made to act on a movable part and a several arm is arrange | positioned in an open position. Therefore, it can be suppressed that the gripping hand is difficult to grip the workpiece due to the postures of the plurality of arms arranged at the open position.

In the gripping hand, when an external force does not act on the movable part, it is preferable that the plurality of arms are arranged at the closed position.
According to the above configuration, the plurality of arms are arranged at the closed position without applying an external force to the movable part. For this reason, even if an external force is not applied to the movable part, the gripping hand can maintain a state in which the workpiece is gripped by the elasticity of the plurality of arms. In other words, when the gripping hand grips the workpiece, it is not necessary to continuously apply an external force to the movable part.

  In the gripping hand, the plurality of arms are formed integrally with the movable portion, and a cross-sectional area perpendicular to the extending direction of the arm at the base end portion of the arm gradually increases toward the movable portion. It is preferable to be smaller.

  When the rigidity of the end part (base end part) connected to the movable part in the arm is high, the arm is difficult to displace relative to the movable part, and the external force required to reciprocate the movable part increases. Cheap. In this regard, according to the above configuration, the rigidity of the end portion of the arm connected to the movable portion tends to be low. For this reason, in order to displace the arm from the open position to the closed position, the external force applied to the movable portion can be reduced.

  In the gripping hand, the restricting portion has elasticity and is integrally formed with the arm so as to extend in a direction intersecting the arm, and at the end of the restricting portion connected to the arm, It is preferable that the cross-sectional area perpendicular to the extending direction becomes gradually smaller toward the arm.

  When the end portion connected to the arm in the restricting portion is high in rigidity, the restricting portion and the arm are relatively difficult to displace, and the external force required to reciprocate the movable portion tends to increase. In this regard, according to the above configuration, the rigidity of the end portion connected to the arm in the limiting portion is likely to be low. For this reason, in order to displace the arm from the open position to the closed position, the external force applied to the movable portion can be reduced.

In the gripping hand, it is preferable that a cross-sectional area perpendicular to the extending direction of the arm at the distal end portion of the arm is gradually reduced toward the distal end of the arm.
According to the above configuration, when the gripping hand grips one or more workpieces from a plurality of stacked workpieces, the tip of the arm easily enters a gap formed between the stacked workpieces. For this reason, the gripping hand is easy to grip one or more workpieces from a plurality of stacked workpieces.

In the gripping hand, it is preferable that a space is formed between the movable part and the plurality of arms arranged at the closed position.
According to the above configuration, when the gripping hand grips the workpiece, a part or all of the workpiece can be stored in the space. For this reason, when the gripping hand grips the workpiece, the posture of the workpiece is easily stabilized.

  In the gripping hand, it is preferable that the movable portion has a circular cross section perpendicular to the first movement direction, and the plurality of arms are provided at equal intervals in the circumferential direction of the movable portion.

  According to the above configuration, the gripping device is less susceptible to the influence of the shape and posture of the workpiece when gripping the workpiece.

  According to the gripping hand configured as described above, it is difficult to be affected by the shape and posture of the workpiece when gripping the workpiece.

FIG. 2 is a schematic diagram of a transfer device according to the first embodiment. Sectional drawing of the holding | grip apparatus of 1st Embodiment. It is a figure which shows the holding hand of the holding apparatus of 1st Embodiment, Comprising: (a), (b) is a perspective view, (c) is sectional drawing. The disassembled perspective view of the connection part of the holding | grip apparatus of 1st Embodiment. The schematic diagram explaining operation | movement of the holding | grip hand of 1st Embodiment. Sectional drawing of the holding | grip apparatus of 1st Embodiment. The flowchart which shows the flow of the process which a control part performs when conveying a workpiece | work in 1st Embodiment. (A)-(c) is an end elevation which shows a change of a situation when the holding hand of a 1st embodiment holds a comparatively big work. (A)-(c) is an end elevation which shows a change of a situation when the holding hand of a 1st embodiment holds a comparatively small work. Schematic of the conveying apparatus of 2nd Embodiment. Sectional drawing of the holding | gripping apparatus of 2nd Embodiment. Sectional drawing of the holding | gripping apparatus of 2nd Embodiment. In 2nd Embodiment, the flowchart which shows the flow of the process which a control part performs when conveying a workpiece | work. The perspective view which shows other embodiment of a holding hand. Sectional drawing which shows other embodiment of a holding | grip hand. The perspective view which shows other embodiment of a holding hand. The perspective view which shows other embodiment of a holding hand.

(First embodiment)
Hereinafter, a first embodiment of a transfer device will be described with reference to the drawings. The transport device according to the first embodiment is a device that transports a workpiece using a gripping device having a gripping hand that grips the workpiece.

  As shown in FIG. 1, the transport device 10 includes a gripping device 20 that grips a workpiece (hereinafter also referred to as “work W”), a first moving mechanism 11 that moves the gripping device 20, and a gripping device 20. A second moving mechanism 12 that moves together with the first moving mechanism 11, and a control unit 13 that controls the gripping device 20, the first moving mechanism 11, and the second moving mechanism 12 are provided.

  In the first embodiment, the direction in which the second moving mechanism 12 moves the gripping device 20 and the second moving mechanism 12 is the first direction D1, and the direction in which the first moving mechanism 11 moves the gripping device 20 is the third direction D3. And A direction orthogonal to both the first direction D1 and the third direction D3 is defined as a second direction D2. In the first embodiment, the third direction D3 is also the vertical direction.

  As shown in FIG. 2, the gripping device 20 includes a gripping hand 30 that grips the workpiece W, a housing 40 that houses some constituent members of the gripping device 20, an actuator 50 that operates the gripping hand 30, and an actuator 50. And a connecting portion 60 that connects the gripping hand 30 to each other.

  As shown in FIGS. 3A, 3 </ b> B, and 3 </ b> C, the gripping hand 30 includes a movable part 31 that reciprocates by the action of an external force, a plurality of arms 32 that extend from the movable part 31, It has the support part 33 which supports the site | part between the edge part 321 and the front-end | tip part 322 on the opposite side, and the driven rod 34 extended in the direction different from the arm 32 from the movable part 31.

  In the gripping hand 30, the movable portion 31, the plurality of arms 32, and the support portion 33 are integrally formed of rubber or resin that can be elastically deformed larger than a metal material. For example, the gripping hand 30 may be molded by casting (crosslinking) rubber and resin after pouring into a mold. In this case, depending on the material of the gripping hand 30, even if the gripping hand 30 has a shape having an undercut, it can be molded with a normal mold.

  The movable portion 31 has a substantially ellipsoidal shape and has a circular cross-sectional shape orthogonal to the axial direction. The movable portion 31 reciprocates in the second movement direction M2 that is opposite to the first movement direction M1 and the first movement direction M1 by the action of external force via the driven rod 34. The first movement direction M1 and the second movement direction M2 are the axial directions of the movable part 31, and are also the third direction D3.

  As shown in FIGS. 3A and 3B, the plurality of arms 32 are provided at equal intervals in the circumferential direction of the movable portion 31. In other words, the plurality of arms 32 extend radially from the movable portion 31 in a direction intersecting the first movement direction M1. Note that the equal interval here does not mean that the interval between adjacent arms 32 in the circumferential direction of the movable portion 31 is exactly the same, but may include an error in manufacturing. As shown in FIG. 3 (c), the arm 32 bends (bends) toward the second movement direction M2 after moving toward the first movement direction M1 as it moves outward in the radial direction of the movable portion 31. ing.

  As shown in FIG. 3C, the cross-sectional area perpendicular to the extending direction of the arm 32 at the proximal end portion 321 of the arm 32 gradually decreases toward the movable portion 31. In the distal end portion 322 of the arm 32, the cross-sectional area perpendicular to the extending direction of the arm 32 gradually decreases as the arm 32 moves from the proximal end toward the distal end. For this reason, the front-end | tip part 322 of the arm 32 becomes a claw shape to taper. As shown in FIG. 3B, in the first embodiment, the base end portions 321 and the portions near the base end portions 321 of the plurality of arms 32 are integrated in the circumferential direction of the movable portion 31.

  As shown in FIG. 3A, the support portion 33 has a substantially cylindrical shape and extends in a direction crossing the arm 32. As shown in FIG. 3C, the outer diameter of the support portion 33 is constant in the axial direction, and the inner diameter of the support portion 33 increases as it goes from the first end (upper end) to the second end (lower end) in the axial direction. Become. For this reason, the cross-sectional area orthogonal to the extending direction of the support portion 33 at the end portion of the support portion 33 connected to the arm 32 gradually decreases toward the arm 32.

  As shown in FIG. 3C, the driven rod 34 extends from the movable portion 31 in the first movement direction M1. The driven rod 34 includes a rod-shaped shaft portion 341, an engaging portion 342 that engages with the connecting portion 60, and an anchor 343 embedded in the movable portion 31. The engaging portion 342 is fixed to a first end (upper end) in the axial direction of the driven rod 34, and the anchor 343 is fixed to a second end (lower end) in the axial direction of the driven rod 34.

  The engaging portion 342 has a polygonal column shape having a larger outer shape than the shaft portion 341. The anchor 343 has a disk shape having a larger outer diameter than the shaft portion 341. The anchor 343 is preferably integrated with the movable portion 31 together with the second end of the shaft portion 341 when the gripping hand 30 is integrally formed. The engaging portion 342 and the anchor 343 may be fixed to the shaft portion 341 in a manner such as fastening, fitting, adhesion, and welding.

  As shown in FIG. 2, the housing 40 has a cylindrical shape. The housing 40 has a cover 42 that covers an opening 41 that opens to the side of the housing 40. A housing recess 43 for housing the support portion 33 of the gripping hand 30 is provided at the second end (lower end) in the axial direction of the housing 40. The housing recess 43 has an inner diameter corresponding to the outer diameter of the support portion 33 of the gripping hand 30. The cover 42 is detachably attached to the housing 40 by a fastening member such as a bolt. When the cover 42 is removed from the housing 40, the inside of the housing 40 is exposed through the opening 41. The housing 40 accommodates a part of the support rod 33 of the gripping hand 30, the driven rod 34 of the gripping hand 30, the connecting portion 60, and a drive rod 53 of the actuator 50 described later.

  As shown in FIG. 2, the actuator 50 includes a cylinder 52 provided with a cylindrical inner space 51, a drive rod 53 that expands and contracts with respect to the cylinder 52, a compressor 54 and a cylinder as an example of a supply source of compressed air. 52, a solenoid valve 55 that switches a connection state with the internal space 51, and a first detector 56 and a second detector 57 that detect the position of the drive rod 53.

  The cylinder 52 is fixed to a first end (upper end) in the axial direction of the housing 40. The cylinder 52 is provided with a first flow path 521 and a second flow path 522 that connect the outside of the cylinder 52 and the internal space 51 of the cylinder 52. The first flow path 521 opens at a first end (upper end) in the axial direction of the internal space 51 of the cylinder 52, and the second flow path 522 is a second end (lower end) in the axial direction of the internal space 51 of the cylinder 52. Is open.

  The drive rod 53 includes a rod-shaped shaft portion 531 and a piston 532 that slides on the inner peripheral surface of the cylinder 52. A piston 532 is provided at a first end (upper end) in the axial direction of the shaft portion 531. The piston 532 is disposed so as to partition the internal space 51 of the cylinder 52 in the axial direction. In the internal space 51 of the cylinder 52, one space partitioned by the piston 532 is connected to the first flow path 521, and the other space is connected to the second flow path 522. A second end (lower end) in the axial direction of the shaft portion 531 is fixed to the connecting portion 60.

  The solenoid valve 55 connects the atmosphere and the first flow path 521 while connecting the compressor 54 and the second flow path 522, and connects the compressor 54 and the first flow path 521. To switch between the second state in which the atmosphere and the second flow path 522 are connected.

  The first detection unit 56 is disposed at a position near the first end (upper end) in the axial direction of the cylinder 52, and the second detection unit 57 is disposed at a position near the second end (lower end) in the axial direction of the cylinder 52. Is done. The first detection unit 56 detects a state in which the drive rod 53 is most contracted with respect to the cylinder 52, and the second detection unit 57 detects a state in which the drive rod 53 is extended most with respect to the cylinder 52. In other words, the first detection unit 56 detects whether or not the piston 532 is displaced to the first end of the internal space 51 of the cylinder 52, and the second detection unit 57 detects that the piston 532 is the internal space 51 of the cylinder 52. It is detected whether it is displaced to the 2nd end. As an example, when a magnet is provided in the piston 532, the first detection unit 56 and the second detection unit 57 may be magnetic sensors that detect the magnetism of the magnet provided in the piston 532.

  Then, the actuator 50 displaces (contracts) the drive rod 53 in the first movement direction M1 or displaces (extends) the drive rod 53 in the second movement direction M2 by switching the electromagnetic valve 55.

  As shown in FIG. 4, the connecting portion 60 has a substantially cylindrical shape. The connecting portion 60 includes a main body portion 61 to which the drive rod 53 is fixed, a clamping portion 62 that sandwiches the driven rod 34 together with the main body portion 61, and a fixing member 63 that fixes the clamping portion 62 to the main body portion 61.

  As shown in FIG. 4, the second end (lower end) of the drive rod 53 is fixed to the first end (upper end) of the main body 61 in the axial direction of the connecting portion 60. A concave portion 611 is provided in the radial direction of the connecting portion 60 at the second end (lower end) of the main body portion 61 in the axial direction of the connecting portion 60. The recess 611 is provided with a first engagement hole 612 and a second engagement hole 613 that have the radial direction of the connecting portion 60 in the depth direction so as to be adjacent to each other in the axial direction of the connecting portion 60. In the axial direction of the connecting portion 60, the first engagement hole 612 is provided on the first end side (upper side) than the second engagement hole 613. Further, the opening length of the first engagement hole 612 is longer than the opening length of the second engagement hole 613 in the direction (second direction D2) perpendicular to the axial direction of the connecting portion 60. Specifically, the opening length of the first engagement hole 612 is a length according to the outer shape of the engagement portion 342 of the driven rod 34, and the opening length of the second engagement hole 613 is the driven rod 34. This is a length corresponding to the outer diameter of the shaft portion 341. Further, the sandwiching portion 62 has a semi-cylindrical shape corresponding to the concave portion 611 of the main body portion 61. The clamping part 62 is provided with an engagement hole (not shown) corresponding to the first engagement hole 612 of the main body 61 at a portion facing the recess 611 of the main body 61.

  When the connecting portion 60 connects the drive rod 53 and the driven rod 34, the shaft portion 341 and the engaging portion of the driven rod 34 of the first engaging hole 612 and the second engaging hole 613 of the main body portion 61. In a state where the 342 is accommodated, the holding portion 62 is fixed to the main body portion 61 by the fixing member 63. Then, the engaging portion 342 of the driven rod 34 is engaged with the step between the first engaging hole 612 and the second engaging hole 613, and the axial movement of the driven rod 34 with respect to the connecting portion 60 is restricted. . Further, the shaft portion 341 and the engaging portion 342 of the driven rod 34 are sandwiched between the main body portion 61 and the clamping portion 62, and the movement of the driven rod 34 in the radial direction with respect to the connecting portion 60 is restricted. Thus, the connecting portion 60 connects the drive rod 53 and the driven rod 34. When the connecting portion 60 releases the connection between the drive rod 53 and the driven rod 34, the driven rod 34 may be removed from the main body portion 61 after removing the clamping portion 62 from the main body portion 61.

  As shown in FIG. 2, the drive rod 53 of the actuator 50 and the driven rod 34 of the gripping hand 30 are connected to each other through a connecting portion 60 inside the housing 40. As a result, the actuator 50 can apply an external force to the movable portion 31 via the drive rod 53, the connecting portion 60, and the driven rod 34.

  As shown in FIG. 1, the first moving mechanism 11 is a direct acting actuator that can reciprocate the gripping device 20 in the third direction D3 (the first moving direction M1 and the second moving direction M2). Good. The second moving mechanism 12 may be a direct acting actuator that can reciprocate the gripping device 20 and the first moving mechanism 11 in the first direction D1. For example, the first moving mechanism 11 and the second moving mechanism 12 may be composed of an air cylinder, a hydraulic cylinder, an electric actuator, and the like.

Next, operations of the plurality of arms 32 of the gripping hand 30 will be described with reference to FIG. In FIG. 5, hatching of the gripping hand 30 is omitted for ease of explanation.
As shown in FIG. 5, when the driven rod 34 (drive rod 53) is displaced in the first movement direction M1, the movable part 31 moves from the “second position” protruding in the second movement direction M2 to the first movement direction M1. It is displaced to the “first position” where it is retracted. Then, the base end portion 321 of the arm 32 is pulled by the movable portion 31 that is displaced in the first movement direction M1, and the base end portion 321 of the arm 32 is displaced together with the movable portion 31 in the first movement direction M1. At this time, the arm 32 rotates about the connection part P1 with the movable part 31 as the rotation center while being elastically deformed.

  On the other hand, the displacement of the support portion 33 in the first movement direction M <b> 1 is limited by the housing 40. For this reason, the support part 33 restrict | limits the displacement to the 1st movement direction M1 about the site | part (connection site | part P2 with the support part 33) between the front-end | tip part 322 and the base end part 321 of the arm 32. As a result, the arm 32 rotates around a portion where the displacement of the support portion 33 is limited (a connection portion P2 with the support portion 33).

  That is, in the arm 32, the base end portion 321 is displaced in the first movement direction M1, with the support portion 33 being limited in displacement in the first movement direction M1, while the distal end portion 322 is in the second movement direction. Displacement to M2. As a result, the plurality of arms 32 are displaced from an “open position” where the tip portions 322 are separated from each other to a “closed position” where the tip portions 322 are close to each other. In the first embodiment, the support portion 33 corresponds to an example of a “restriction portion” that restricts the displacement of the arm 32 in the first movement direction M1.

  Thus, in the first embodiment, when the driven rod 34 (drive rod 53) is displaced in the second movement direction M2 and the movable portion 31 is located at the second position, the plurality of arms 32 are arranged at the open position. Is done. Further, when the driven rod 34 (drive rod 53) is displaced in the first movement direction M1 and the movable portion 31 is positioned at the first position, the plurality of arms 32 are disposed at the closed position. In FIG. 5, the first position is the position of the movable portion 31 indicated by the two-dot chain line, and the closed position is the position of the plurality of arms 32 indicated by the two-dot chain line. The second position is the position of the movable part 31 indicated by a solid line, and the open position is the position of a plurality of arms 32 indicated by a solid line.

  In the gripping hand 30, the movable part 31, the plurality of arms 32, and the support part 33 are integrally formed elastic bodies. Therefore, as indicated by a two-dot chain line in FIG. 5, when the force that the arm 32 pushes the support portion 33 in the first movement direction M1 increases as the movable portion 31 is displaced in the first movement direction M1, the support is increased. The portion 33 may be elastically deformed. That is, in this case, the position of the rotation center of the arm 32 with respect to the support portion 33 (the connection portion P2 with the support portion 33) moves according to the displacement of the movable portion 31 in the first movement direction M1. Become.

  Further, as shown by a two-dot chain line in FIG. 5, since the plurality of arms 32 of the first embodiment are curved as shown, the plurality of arms 32 arranged in the closed position are in the first position. A space is formed between the movable part 31 to be arranged. The size and shape of this space can be changed by changing the length of the arm 32 or changing the bending mode of the arm 32.

Moreover, in 1st Embodiment, as shown in FIG.3 and FIG.5, when an external force does not act on the movable part 31 of the holding hand 30, the some arm 32 is arrange | positioned in an open position.
Next, the control target and control contents of the control unit 13 will be described.

  As shown in FIG. 1, the control unit 13 controls the first moving mechanism 11 to move the gripping device 20 in the third direction D3 (the first moving direction M1 and the second moving direction M2). Thus, the control unit 13 causes the gripping device 20 to approach the workpiece support unit (hereinafter also referred to as “work support unit 14”) that supports the workpiece W, or retracts the gripping device 20 from the workpiece support unit 14. To do. Further, the control unit 13 controls the second moving mechanism 12 to move the gripping device 20 and the first moving mechanism 11 in the first direction D1. In this way, the control unit 13 moves the gripping device 20 and the first moving mechanism 11 between the position that becomes the transfer source of the workpiece W and the position that becomes the transfer destination. Note that the workpiece support unit 14 may be a table on which one or more workpieces W are placed, or a container in which one or more workpieces W are accommodated.

  As shown in FIG. 2, the control unit 13 controls the actuator 50 (electromagnetic valve 55) to reciprocate the drive rod 53. Specifically, as shown in FIG. 6, the control unit 13 switches the electromagnetic valve 55 to the first state and displaces the drive rod 53 in the first movement direction M1, or as shown in FIG. Is switched to the second state, and the drive rod 53 is displaced in the second movement direction M2. Furthermore, the control unit 13 acquires the position of the drive rod 53 with respect to the cylinder 52 based on signals output from the first detection unit 56 and the second detection unit 57.

  When the gripping hand 30 grips the workpiece W, the control unit 13 moves the gripping device 20 in the second movement direction M2 to approach the workpiece support unit 14. Thereafter, the control unit 13 displaces the plurality of arms 32 of the gripping hand 30 from the open position to the closed position. Then, the plurality of arms 32 of the gripping hand 30 sandwich the work W, and the gripping hand 30 grips the work W.

  Here, in order for the gripping hand 30 to grip the workpiece W, when the plurality of arms 32 are displaced from the open position to the closed position, the gripping hand 30 is sufficiently close to the workpiece W or the gripping hand 30 is It is preferably in a state in contact with W. In other words, if the plurality of arms 32 are displaced from the open position to the closed position while the gripping hand 30 is away from the work W, the gripping hand 30 may not be able to grip the work W.

  Therefore, the control unit 13 controls the timing at which the plurality of arms 32 are displaced from the open position to the closed position based on the displacement of the driven rod 34 when the gripping device 20 is moved in the second movement direction M2. Specifically, when the gripping device 20 is continuously moved in the second movement direction M2, the gripping hand 30 comes into contact with the workpiece W. Then, the movable portion 31 of the gripping hand 30 is displaced in the first movement direction M1, so that the driven rod 34, the connecting portion 60, and the drive rod 53 are displaced in the first movement direction M1. That is, when the gripping hand 30 comes into contact with the workpiece W, the piston 532 of the drive rod 53 is displaced outside the detection range of the second detection unit 57. Therefore, after the piston 532 of the drive rod 53 is displaced outside the detection range of the second detection unit 57, the plurality of arms 32 are closed from the open position in a state where the gripping hand 30 is in contact with the workpiece W. Can be displaced.

  Thus, when the control unit 13 moves the gripping device 20 in the second movement direction M2, the driven rod 34 (drive rod 53) is displaced in the first movement direction M1 based on the detection result of the second detection unit 57. Get timing. Then, the control unit 13 stops the movement of the gripping device 20 in the second movement direction M2 based on the timing at which the driven rod 34 (drive rod 53) is displaced in the first movement direction M1, and a plurality of gripping hands 30 are provided. The arm 32 is displaced from the open position to the closed position.

  Here, in the first embodiment, as shown in FIG. 3C, when the plurality of arms 32 of the gripping hand 30 are arranged in the open position, the movable portion 31 of the gripping hand 30 is more than the plurality of arms 32. It slightly protrudes in the second movement direction M2. For this reason, when the gripping device 20 moves in the second movement direction M <b> 2, the movable portion 31 easily comes into contact with the workpiece W before the plurality of arms 32. Therefore, the control unit 13 can more accurately acquire the timing at which the gripping hand 30 contacts the workpiece W based on the detection result of the second detection unit 57.

  Next, a flow of processing executed by the control unit 13 when the transport apparatus 10 grips a medium will be described with reference to a flowchart shown in FIG. In addition, when the control part 13 performs this process, the several arm 32 of the holding | grip hand 30 shall be arrange | positioned in the open position.

  As shown in FIG. 7, the control unit 13 drives the second moving mechanism 12 to move the gripping device 20 so that the gripping device 20 is positioned in the first movement direction M1 of the work support unit 14 (step S11). . Then, the control part 13 drives the 1st moving mechanism 11, and moves the holding | gripping apparatus 20 to the 2nd moving direction M2 (step S12). Subsequently, the control unit 13 determines whether or not the drive rod 53 (the driven rod 34) is displaced in the first movement direction M1 based on the signal output from the second detection unit 57 (step S13). When the drive rod 53 (the driven rod 34) is not displaced in the first movement direction M1 (step S13: NO), that is, when the gripping hand 30 is not in contact with the workpiece W, the control unit 13 performs the step again. The process of S13 is executed. In this case, the movement of the gripping device 20 in the second movement direction M2 is continued.

  In step S13, when the drive rod 53 (driven rod 34) is displaced in the first movement direction M1 (step S13: YES), that is, when the gripping hand 30 is in contact with the workpiece W, the control unit 13 performs the first movement. The driving of the mechanism 11 is stopped, and the movement of the gripping device 20 in the second movement direction M2 is stopped (step S14). Thereafter, the control unit 13 drives the actuator 50 to displace the drive rod 53 in the first movement direction M1 (step S15). That is, the control unit 13 displaces the plurality of arms 32 of the gripping hand 30 from the open position to the closed position, and causes the gripping hand 30 to grip the workpiece W. Subsequently, the control unit 13 drives the first movement mechanism 11 to move the gripping device 20 in the first movement direction M1 (step S16).

  Then, the control part 13 drives the 2nd moving mechanism 12, and moves the holding | gripping apparatus 20 and the 1st moving mechanism 11 to the position used as the conveyance destination of the workpiece | work W (step S17). And the control part 13 drives the actuator 50, and displaces the drive rod 53 to the 2nd movement direction M2 (step S18). That is, the control unit 13 causes the gripping hand 30 to release the workpiece W. In addition, before execution of the process of step S18, the control part 13 may drive the 1st moving mechanism 11, and may move the holding | gripping apparatus 20 to the 2nd movement direction M2. Then, the control part 13 complete | finishes this process.

  Next, with reference to FIGS. 8 and 9, an operation when the gripping device 20 of the transport apparatus 10 grips the workpiece W will be described. In the description of the action, it is assumed that the gripping device 20 has moved in the second movement direction M2 until the gripping hand 30 has already contacted the workpiece W.

First, a case where the gripping device 20 grips a relatively large workpiece W will be described with reference to FIG.
As shown in FIG. 8A, when the movable portion 31 of the gripping hand 30 disposed at the second position contacts the workpiece W, the actuator 50 starts the displacement of the driven rod 34 in the first movement direction M1. That is, the plurality of arms 32 of the gripping hand 30 starts to be displaced from the open position to the closed position.

  Then, as shown in FIG. 8B, the tips 322 of the plurality of arms 32 come into contact with the workpiece W while the plurality of arms 32 are displaced from the open position to the closed position. Here, even after the plurality of arms 32 come into contact with the workpiece W, they tend to continue to be displaced toward the closed position. For this reason, the plurality of arms 32 are elastically deformed while receiving a reaction force from the workpiece W. In other words, the plurality of arms 32 are elastically deformed to match the shape of the workpiece W.

  And as shown in FIG.8 (c), when the driven rod 34 finishes displacement to the 1st movement direction M1, the movable part 31 of the holding | grip hand 30 will be arrange | positioned in a 1st position. That is, the plurality of arms 32 of the gripping hand 30 sandwich the work W, and the gripping hand 30 grips the work W.

Next, a case where the gripping device 20 grips a relatively small work W will be described with reference to FIG.
As shown in FIG. 9A, when the movable part 31 of the gripping hand 30 arranged at the second position contacts the work W, the actuator 50 follows the same as when gripping a relatively large work W. The rod 34 starts to be displaced in the first movement direction M1. That is, the plurality of arms 32 of the gripping hand 30 starts to be displaced from the open position to the closed position.

  Then, as shown in FIG. 9B, the tips 322 of the plurality of arms 32 come into contact with the workpiece W while the plurality of arms 32 are displaced from the open position to the closed position. However, in this case, the timing at which the tip portions 322 of the plurality of arms 32 come into contact with the workpiece W is later than in the case shown in FIG. That is, the position of the movable part 31 shown in FIG. 9B is closer to the first position than the position of the movable part 31 shown in FIG. That is, as the work W is small, the plurality of arms 32 are displaced to the position closer to the closed position, and then the tips 322 of the plurality of arms 32 come into contact with the work W. However, since the plurality of arms 32 continue to be displaced toward the closed position even after the distal end portion 322 contacts the workpiece W, the plurality of arms 32 are elastically deformed so as to match the shape of the workpiece W.

  Then, as shown in FIG. 9C, when the driven rod 34 has been displaced in the first movement direction M1, the movable portion 31 of the gripping hand 30 is disposed at the first position. That is, the plurality of arms 32 of the gripping hand 30 sandwich the work W, and the gripping hand 30 grips the work W.

  As described above, the gripping device 20 (grip hand 30) can grip the workpiece W regardless of the size of the workpiece W. 8 and 9, the case has been described in which the gripping device 20 (grip hand 30) grips a workpiece W having a different shape. However, the gripping device 20 (grip hand 30) has the same shape of the workpiece W having a different posture. The same applies to the case of gripping.

According to the first embodiment described above, the following effects can be obtained.
(1) When the workpiece W is gripped by the gripping hand 30, the movable portion 31 is displaced in the first movement direction M1 while the gripping hand 30 is in contact with the workpiece W. Then, the plurality of arms 32 of the gripping hand 30 are displaced from the open position to the closed position, and the plurality of arms 32 sandwich the workpiece W. Here, since the plurality of arms 32 have elasticity, they can be elastically deformed according to the shape of the workpiece W. That is, the plurality of arms 32 are elastically deformed according to the workpiece W whose shape and posture are not constant, and the gaps between the plurality of arms 32 and the workpiece W are less likely to occur. Thus, the gripping hand 30 is not easily affected by the shape and posture of the workpiece W when gripping the workpiece W.

  (2) When the rigidity of the end portion (base end portion 321) connected to the movable portion 31 in the arm 32 is high, the movable portion 31 and the arm 32 are relatively difficult to displace, and the movable portion 31 is reciprocated. Because of this, the external force required for this is likely to increase. In this respect, according to the first embodiment, the rigidity of the end portion is likely to be lowered by the amount of the sectional area of the end portion of the arm 32 connected to the movable portion 31 being reduced. For this reason, in order to displace the arm 32 from the open position to the closed position, the external force applied to the movable portion 31 can be reduced.

  (3) When the rigidity of the end portion connected to the arm 32 in the support portion 33 is high, the support portion 33 and the arm 32 are relatively difficult to displace, and the external force that acts on the movable portion 31 tends to increase. In this regard, according to the first embodiment, the rigidity of the end portion is likely to be lowered by the amount of the cross-sectional area of the end portion connected to the arm 32 in the support portion 33 being reduced. For this reason, in order to displace the arm 32 from the open position to the closed position, the external force applied to the movable portion 31 can be reduced.

  (4) At the tip 322 of the arm 32, the cross-sectional area perpendicular to the extending direction of the arm 32 is gradually reduced toward the tip of the arm 32. For this reason, when the gripping hand 30 grips one or more workpieces W from a plurality of stacked workpieces W, the distal end portion 322 of the arm 32 easily enters a gap formed between the stacked workpieces W. For this reason, the gripping hand 30 can easily grip one or more workpieces W from the plurality of stacked workpieces W. Further, when the gripping hand 30 grips the workpiece W having a hole or an uneven shape, the distal end portion 322 of the arm 32 easily enters the hole or the uneven shape of the work W. For this reason, the gripping hand 30 can easily grip the workpiece W having a hole or an uneven shape.

  (5) By curving the arm 32, a space is formed between the movable portion 31 of the gripping hand 30 and the plurality of arms 32 arranged at the closed position. According to this, when the gripping hand 30 grips the workpiece W, a part or all of the workpiece W can be stored in the space. For this reason, when the gripping hand 30 grips the workpiece W, the posture of the workpiece W is easily stabilized.

(6) Since the plurality of arms 32 are provided at equal intervals in the circumferential direction of the movable portion 31, the gripping hand 30 is less susceptible to the shape and posture of the workpiece W when gripping the workpiece W.
(7) The actuator 50 applies an external force to the movable portion 31 via the driven rod 34. For this reason, unlike the case where the actuator 50 directly applies an external force to the movable part 31 of the gripping hand 30, the actuator 50 does not have to be arranged near the movable part 31. For this reason, the freedom degree of design of the holding | grip apparatus 20 can be raised.

  (8) Since the driven rod 34 of the gripping hand 30 has the anchor 343 embedded in the movable portion 31, the movable portion 31 and the driven rod 34 can be firmly integrated. For example, the movable portion 31 and the driven rod 34 are bonded by bonding the driven rod 34 with an adhesive, or by providing the concave and convex shapes corresponding to the movable portion 31 and the driven rod 34. Compared with the case where the rod 34 is integrated, the driven rod 34 is less likely to be detached from the movable portion 31.

  (9) The gripping hand 30 can be easily replaced with another gripping hand 30 by the connecting portion 60 that detachably connects the driven rod 34 and the drive rod 53. For this reason, the gripping device 20 can also use different gripping hands 30 suitable for the workpieces W having different sizes and shapes. When exchanging the gripping hand 30, the opening portion 41 is provided in the housing 40, so that the driven rod 34 can be easily attached to and detached from the connecting portion 60.

  (10) When the gripping device 20 moves in the second movement direction M2, the control unit 13 moves the plurality of arms 32 from the open position to the closed position based on the displacement of the driven rod 34 in the first movement direction M1. Control the timing of displacement. Therefore, the control unit 13 closes the arms 32 from the open position at a timing suitable for the gripping hand 30 to grip the workpiece W without detecting the relative distance between the gripping hand 30 and the workpiece W. It can be displaced to a position.

  (11) When the workpiece W is gripped by the gripping hand 30, the plurality of arms 32 are opened at the movable portion 31 in contact with the workpiece W so that the plurality of arms 32 can sandwich the workpiece W. It is preferable to displace from to the closed position. For example, when the plurality of arms 32 are arranged at the open position, if the tip end portion 322 of the arm 32 protrudes in the second movement direction M2 (to the workpiece W side) from the movable portion 31, the following problem occurs. May occur. That is, when the gripping device 20 is brought close to the workpiece W, the arm 32 comes into contact with the workpiece W or the workpiece support portion 14 before the movable portion 31, and the movable portion 31 may be displaced. In other words, the control unit 13 may cause the plurality of arms 32 to be displaced from the open position to the closed position while the movable unit 31 is not in contact with the workpiece W.

  On the other hand, according to the first embodiment, when the plurality of arms 32 are arranged at the open position, the movable portion 31 protrudes in the second movement direction M2 from the distal end portion 322 of the arm 32. For this reason, when the gripping device 20 is brought close to the work W, the movable portion 31 is likely to come into contact with the work W before the arm 32. Therefore, the gripping device 20 can displace the plurality of arms 32 from the open position to the closed position at an appropriate timing.

  (12) When the plurality of arms 32 of the gripping hand 30 are displaced from the open position to the closed position, the distal end portions 322 of the arms 32 gather toward the axis of the movable portion 31. For this reason, the gripping hand 30 can scrape the workpiece W toward the axis of the movable portion 31 in a situation where relatively small workpieces W are scattered on the workpiece support portion 14.

  (13) Since the tip portions 322 of the plurality of arms 32 of the gripping hand 30 are tapered, a gap is created between the tip portions 322 of the adjacent arms 32 when the plurality of arms 32 are disposed at the closed position. Hateful. For this reason, when the workpiece W is accommodated in the space between the movable portion 31 and the plurality of arms 32, the workpiece W is not easily dropped from the gripping hand 30.

  (14) Since the gripping hand 30 has a plurality of arms 32 that can be elastically deformed independently, when gripping the workpiece W, the plurality of arms 32 can be elastically deformed in different modes. That is, since the plurality of arms 32 are independently elastically deformed so as to match the shape of the workpiece W, the arms 32 that do not contact the workpiece W are unlikely to occur. Thus, the posture of the workpiece W is stabilized when the gripping device 20 (grip hand 30) grips the workpiece W in that all of the plurality of arms 32 easily come into contact with the workpiece W.

(Second Embodiment)
Hereinafter, a second embodiment of the transfer device will be described. The second embodiment is mainly different from the first embodiment in the structure of an actuator 50 that reciprocates the movable portion 31 of the gripping hand 30. For this reason, in 2nd Embodiment, a different part from 1st Embodiment is demonstrated, the code | symbol same about the structure which is common in 1st Embodiment is attached | subjected, and description about a structure, an effect | action, and an effect is abbreviate | omitted.

  As illustrated in FIG. 10, the transport device 10A includes a gripping device 20A, a first moving mechanism 11, a second moving mechanism 12, and a control unit 13A. As shown in FIG. 11, the gripping device 20A includes a gripping hand 30A that grips the workpiece W, a holder 70 that holds the gripping hand 30A, and an actuator 80 that operates the gripping hand 30A.

  As shown in FIG. 11, the gripping hand 30 </ b> A includes a movable portion 31 that reciprocates by the action of an external force, a plurality of arms 32 extending from the movable portion 31, and a base end portion 321 and a distal end portion 322 of the arm 32. And a support portion 35 that supports the part.

  The support part 35 has a substantially cylindrical shape. The support part 35 extends in a direction intersecting with the arm 32. The outer diameter of the support portion 35 is constant in the axial direction of the support portion 35, and the inner diameter of the support portion 35 increases from the first end (upper end) to the second end (lower end) in the axial direction of the support portion 35. For this reason, the cross-sectional area perpendicular to the extending direction of the support portion 35 at the end of the support portion 35 connected to the arm 32 gradually decreases toward the arm 32. A small-diameter portion 351 having an inner diameter narrower than that of the second end side is provided on the first end side of the support portion 35.

  The holder 70 includes a cylindrical portion 71 having a cylindrical shape and a cylindrical portion 72 having a cylindrical shape. A flow path 711 through which air flows is provided inside the cylindrical portion 71. One end of the flow path 711 opens to the outer peripheral surface of the cylindrical portion 71, and the other end of the flow path 711 opens to a region surrounded by the cylindrical portion 72 in the cylindrical portion 71. As shown in FIG. 10, the first moving mechanism 11 is connected to a first end (upper end) in the axial direction of the cylindrical portion 71. As shown in FIG. 11, the cylindrical portion 72 has an inner diameter that increases from the proximal end connected to the cylindrical portion 71 toward the distal end. On the other hand, an engagement groove 721 having a smaller outer diameter than the outer peripheral surface on the distal end side is provided on the outer peripheral surface on the proximal end side of the cylindrical portion 72.

  Then, the gripping hand 30 </ b> A is attached to the holder 70 by covering the cylindrical portion 72 of the holder 70 with the support portion 35 of the gripping hand 30 </ b> A. At this time, the small diameter portion 351 of the gripping hand 30A is engaged with the engaging groove 721 of the holder 70, and the gap between the gripping hand 30A and the holder 70 is filled. As a result, a closed space CS is formed between the end surface (upper surface) of the movable portion 31 of the gripping hand 30 </ b> A in the first movement direction M <b> 1 and the holder 70. The closed space CS is connected to one end of the flow path 711. In this respect, in the second embodiment, the holder 70 corresponds to an example of a “closed space forming member”.

  The actuator 80 includes a decompression unit 81 that decompresses the closed space CS, an electromagnetic valve 82 that switches a connection state between the decompression unit 81 and the flow path 711, and a pressure detection unit 83 that detects the pressure in the closed space CS. The decompression unit 81 is, for example, a suction pump. The decompression unit 81 sucks air from the closed space CS and decompresses the closed space CS. The electromagnetic valve 82 includes a suction state in which the decompression unit 81 and the flow path 711 are connected, an open state in which the flow path 711 and the atmosphere are connected, and a sealed state in which the flow path 711 is not connected to either the decompression unit 81 or the atmosphere. And switch.

  The electromagnetic valve 82 may be configured by combining a plurality of electromagnetic valves 82. Further, the pressure detection unit 83 may be provided in the closed space CS, may be provided in the flow path 711, or may be provided between the electromagnetic valve 82 and the flow path 711.

Next, the control target and control contents of the control unit 13A will be described.
As shown in FIG. 11, the control unit 13 </ b> A controls the actuator 80 to reciprocate the movable unit 31. Specifically, the control unit 13A switches the electromagnetic valve 82 to the suction state, and causes the decompression unit 81 to decompress the closed space CS. Then, the pressure in the closed space CS decreases, and as shown in FIG. 12, the movable portion 31 is displaced in the direction in which the volume of the closed space CS decreases (first movement direction M1). As a result, the plurality of arms 32 of the gripping hand 30A are displaced from the open position to the closed position.

  On the other hand, the control unit 13A switches the electromagnetic valve 82 to the open state to connect the closed space CS to the atmosphere. Then, the pressure in the closed space CS becomes atmospheric pressure, and the movable portion 31 is displaced in a direction (second movement direction M2) in which the volume of the closed space CS increases as shown in FIG. As a result, the plurality of arms 32 of the gripping hand 30A are displaced from the closed position to the open position.

  Thus, in the second embodiment, the control unit 13A places the plurality of arms 32 of the gripping hand 30A in the open position or in the closed position. The decompression unit 81 and the electromagnetic valve 82 constitute an example of a “pressure adjustment unit” that adjusts the pressure in the closed space CS. Note that the control unit 13A acquires the pressure in the closed space CS based on the output signal from the pressure detection unit 83.

  And 13 A of control parts control the timing which displaces the several arm 32 from an open position to a closed position based on the pressure change of closed space CS when moving the holding | gripping apparatus 20A to the 2nd movement direction M2. That is, also in the second embodiment, by continuing to move the gripping device 20A in the second movement direction M2, the gripping hand 30A comes into contact with the workpiece W, and the movable portion 31 is displaced in the first movement direction M1. At this time, if the electromagnetic valve 82 is switched to the sealed state, the pressure of the closed space CS increases as the volume of the closed space CS decreases. For this reason, after the pressure in the closed space CS increases, the plurality of arms 32 can be displaced from the open position to the closed position while the gripping hand 30A is in contact with the workpiece W.

  Thus, when the control unit 13A moves the gripping device 20A in the second movement direction M2, the control unit 13A acquires the timing at which the movable unit 31 is displaced in the first movement direction M1 based on the detection result of the pressure detection unit 83. Then, the control unit 13A stops the movement of the gripping device 20A in the second movement direction M2 based on the timing when the movable unit 31 is displaced in the first movement direction M1, and opens the plurality of arms 32 of the gripping hand 30A. Displace from position to closed position.

Next, the flow of processing executed by the control unit 13A when the transfer device 10A transfers the workpiece W will be described with reference to the flowchart shown in FIG.
As illustrated in FIG. 13, the control unit 13A drives the second moving mechanism 12 to move the gripping device 20A so that the gripping device 20A is positioned in the first movement direction M1 of the workpiece support unit 14 (step S21). . Thereafter, the controller 13 drives the first movement mechanism 11 to move the gripping device 20A in the second movement direction M2 (step S22). Subsequently, the control unit 13A determines whether or not the pressure in the closed space CS has changed based on the signal output from the pressure detection unit 83 (step S23). Specifically, the control unit 13A determines whether or not the pressure in the closed space CS has increased. For this reason, in step S23, a predetermined determination value is set in advance, and the control unit 13A may determine that the pressure in the closed space CS has changed when the pressure in the closed space CS becomes equal to or higher than the determination value.

  When the pressure in the closed space CS does not change (step S23: NO), that is, when the gripping hand 30A is not in contact with the workpiece W, the control unit 13A executes the process of step S23 again. In this case, the gripping device 20A continues to move in the second movement direction M2.

  In step S23, when the pressure of the closed space CS changes (step S23: YES), that is, when the gripping hand 30A comes into contact with the workpiece W, the control unit 13A stops driving the first moving mechanism 11 and grips it. The movement of the device 20A in the second movement direction M2 is stopped (step S24). Thereafter, the control unit 13A drives the actuator 80 to depressurize the closed space CS (step S25). That is, the control unit 13A displaces the plurality of arms 32 of the gripping hand 30A from the open position to the closed position, and causes the gripping hand 30A to grip the workpiece W. Subsequently, the control unit 13A drives the first moving mechanism 11 to move the gripping device 20 in the first moving direction M1 (step S26).

  Thereafter, the control unit 13A drives the second moving mechanism 12 to move the gripping device 20A and the first moving mechanism 11 to a position that is a transfer destination of the workpiece W (step S27). Then, the controller 13 drives the actuator 80 to release the closed space CS to the atmosphere (Step S28). That is, the control unit 13A displaces the plurality of arms 32 of the gripping hand 30A to the open position, and causes the gripping hand 30A to release the workpiece W. Thereafter, the control unit 13A ends this process.

  In the second embodiment, “raising / lowering the gripping device 20 </ b> A” means raising / lowering at least the constituent members that need to be lifted / lowered among the constituent members of the gripping device 20 </ b> A. That is, the decompression unit 81 and the electromagnetic valve 82 of the actuator 80, which are constituent members that do not need to be raised or lowered among the constituent members of the gripping device 20A, may or may not be raised or lowered.

According to the second embodiment described above, in addition to the effects (1) to (6) and (11) to (14) of the first embodiment, the following effects can be obtained.
(1) When the gripping device 20A is brought close to the workpiece support unit 14, the plurality of arms 32 are arranged in the open position without applying an external force to the movable unit 31. Specifically, the plurality of arms 32 are arranged in the open position without adjusting the pressure in the closed space CS. For this reason, the attitude | position of the some arm 32 arrange | positioned in an open position is stabilized rather than the case where an external force is made to act on the movable part 31, and the some arm 32 is arrange | positioned in an open position. Therefore, it is possible to suppress the gripping hand 30 from becoming difficult to grip the workpiece W due to the postures of the plurality of arms 32 arranged at the open position.

  (2) The decompression unit 81 displaces the movable unit 31 in the direction in which the volume of the closed space CS increases, that is, in the second movement direction M2, by increasing the pressure in the closed space CS. In addition, the decompression unit 81 displaces the movable unit 31 in the direction in which the volume of the closed space CS is reduced, that is, in the first movement direction M1, by reducing the pressure in the closed space CS. For this reason, compared with the case where the actuator 80 is a linear actuator that reciprocates the movable portion 31, the gripping device 20A can be easily downsized in the first movement direction M1.

  (3) When moving the gripping device 20A in the second movement direction M2 to bring the gripping hand 30A closer to the workpiece W, the movable unit 31 moves in the first movement direction at the timing when the gripping hand 30A contacts the workpiece W. Displacement to M1. And the timing which displaces the some arm 32 from an open position to a closed position based on the pressure change of the closed space CS accompanying the displacement of the movable part 31 is controlled. For this reason, even if the relative distance between the gripping hand 30A and the workpiece W is not detected, the plurality of arms 32 are displaced from the open position to the closed position at a timing suitable for gripping the workpiece W by the gripping hand 30A. Can do.

In addition, you may change the said embodiment as shown below.
As shown in FIGS. 14 and 15, the gripping hand 30 </ b> B includes a movable part 31 </ b> B having a disk shape, a plurality of arms 32 </ b> B extending from the movable part 31 </ b> B, a base end part 321 </ b> B and a distal end part 322 </ b> B. And a support portion 33B that supports a portion between the two. The plurality of arms 32B extend linearly from the movable portion 31B. The tip portions 322B of the plurality of arms 32B are formed in a spherical shape. Further, when the arm 32 is disposed at the open position, the tip of the arm 32 is located in the second movement direction M2 relative to the movable portion 31.

  As indicated by a two-dot chain line in FIG. 15, when the driven rod 34 is displaced in the first movement direction M1, the plurality of arms 32B are displaced from the open position to the closed position. At this time, the gripping hand 30B is in a state in which the distal end portion 322B of the arm 32B protrudes in the second movement direction M2. In addition, since the tip portion 322B of the arm 32B is formed in a spherical shape, the gripping hand 30C is easily crushed by the reaction force from the workpiece W when the workpiece W is gripped. For this reason, the contact area between the tip portion 322B of the arm 32 and the work W is likely to be large, and the gripping hand 30C is particularly easy to grip the work W with few irregularities and holes.

  As shown in FIG. 16, the gripping hand 30 </ b> C may be formed so that the plurality of arms 32 are disposed at the closed position when no external force acts on the movable portion 31. In this case, in the gripping hand 30 </ b> C, when an external force is applied to the movable portion 31, the plurality of arms 32 are arranged at the open position. Specifically, the plurality of arms 32 are displaced from the closed position to the open position by displacing the driven rod 34 in the second movement direction M2.

  According to this, even if an external force is not applied to the movable part 31, the plurality of arms 32 are arranged at the closed position. For this reason, the gripping hand 30 </ b> C can maintain the state of gripping the workpiece W by the elasticity of the plurality of arms 32 without applying an external force to the movable portion 31. In other words, when the gripping hand 30 </ b> C grips the workpiece W, it is not necessary to continue to apply an external force to the movable portion 31.

  As shown in FIG. 17, the gripping hand 30D has a movable portion 31D having a substantially plate shape, a pair of arms 32D extending from the movable portion 31D, and a portion between the base end portion 321D and the distal end portion 322D of the arm 32D. And a pair of support portions 33D to support. The movable portion 31D has a rectangular cross-sectional area perpendicular to the first movement direction M1. The pair of arms 32D are provided so as to extend from both end portions in the short direction (first direction D1) of the movable portion 31D. Further, the pair of arms 32D is provided across the longitudinal direction (second direction D2) of the movable portion 31D. According to this, the gripping hand 30D can easily grip a long workpiece having the longitudinal direction of the movable portion 31D as the longitudinal direction.

  The conveyance devices 10 and 10A may include a detection unit that detects the relative distance between the gripping devices 20 and 20A (the gripping hands 30 and 30A) and the workpiece W. In this case, the control units 13 and 13A may control the timing at which the gripping hands 30 and 30A are displaced from the open position to the closed position based on the detection result of the detection unit.

  A detection unit that detects contact with the workpiece W may be provided at the distal end 322 of the arm 32. In this case, the control unit 13 may control the timing at which the gripping hands 30 and 30A are displaced from the open position to the closed position based on the detection result of the detection unit.

  In the first embodiment, the gripping device 20 may include a detection unit that directly detects the displacement of the movable unit 31 or the driven rod 34. In this case, the control part 13 may control the timing which displaces the holding | grip hand 30 from an open position to a closed position based on the detection result of the said detection part.

  The conveyance devices 10 and 10A may include an imaging device that images the workpiece support unit 14. In this case, the control units 13 and 13A may acquire the posture of the workpiece W based on the image captured by the imaging device. Then, the control units 13 and 13A may adjust the position of the gripping device 20, the angle around the axis extending in the first movement direction M1, and the like according to the posture of the workpiece W.

  The gripping hands 30 and 30A may be appropriately changed in shape or the like according to the workpiece W to be gripped. For example, the gripping hands 30, 30 </ b> A may change the length and number of the arms 32, or may provide a difference in elastic modulus in the extending direction of the arms 32.

  In the proximal end portion 321 of the arm 32 of the gripping hands 30, 30 </ b> A, the cross-sectional area perpendicular to the extending direction of the arm 32 may be constant toward the movable portion 31. Further, the cross-sectional area perpendicular to the extending direction of the support portions 33 and 35 at the end portion of the support portion 33 of the gripping hand 30 that is connected to the arm 32 may be constant toward the arm 32.

  The support portions 33 and 35 of the gripping hands 30 and 30A may not be cylindrical. For example, the support portions 33 and 35 may be provided in the same number as the arms 32 so as to extend individually from the plurality of arms 32.

  The arms 32 of the gripping hands 30 and 30 </ b> A may have a fine concavo-convex shape in a portion that can contact the workpiece W. According to this, the workpiece W is easily caught on the uneven shape of the arm 32 of the gripping hand 30. As a result, when the gripping hand 30 grips the workpiece W, the posture of the workpiece W is easily stabilized.

  In the gripping hands 30, 30 </ b> A, the movable part 31 may be formed separately from the arm 32, and the support parts 33, 35 may be formed separately from the arm 32. In this case, it is preferable that the arm 32 is rotatably connected to the movable portion 31 and the support portions 33 and 35.

  In the gripping hands 30, 30 </ b> A, when the support portions 33, 35 and the arm 32 are separated, the support portions 33, 35 are the first part between the distal end portion 322 and the proximal end portion 321 of the arm 32. Any configuration that limits the displacement in the movement direction M1 may be used. For example, in the gripping hand 30 shown in FIG. 2, if the support portion 33 is omitted, the housing 40 functions as an example of the “restriction portion”. That is, when the base end portion 321 of the arm 32 is displaced together with the movable portion 31 in the first movement direction M1, the first movement direction M1 of the portion of the housing 40 between the base end portion 321 and the tip end portion 322 of the arm 32 is detected. Limit displacement to. As a result, the plurality of arms 32 can be displaced from the open position to the closed position with a portion of the housing 40 where displacement in the first movement direction M1 is restricted as a fulcrum.

  -The connection part 60 should just be the structure which can connect the driven rod 34 and the drive rod 53 so that attachment or detachment is possible. For example, the connecting portion 60 may removably connect the driven rod 34 and the drive rod 53 using magnetism, or a structure corresponding to a so-called snap fit is provided on at least one of the driven rod 34 and the drive rod 53. By providing, both may be detachably connected.

  The first moving mechanism 11 may reciprocate the gripping devices 20 and 20A in a direction intersecting the vertical direction. For example, the first moving mechanism 11 may reciprocate the gripping devices 20 and 20 </ b> A in the horizontal direction to bring the gripping devices 20 and 20 </ b> A closer to the workpiece support portion 14 and retreat from the workpiece support portion 14. . In this case, the first movement direction M1 and the second movement direction M2 are also directions that intersect the vertical direction.

  -The material of the workpiece W may be a resin, a metal, or another material. Further, the workpiece W may be a component member of a product or a finished product.

  DESCRIPTION OF SYMBOLS 10,10A ... Conveying device, 11 ... 1st moving mechanism, 12 ... 2nd moving mechanism, 13, 13A ... Control part, 14 ... Work support part, 20, 20A ... Grasping device, 30, 30A, 30B, 30C, 30D ... gripping hand, 31, 31B, 31D ... movable part, 32, 32B, 32D ... arm, 321, 321B, 321D ... base end part, 322, 322B, 322D ... tip part, 33, 33B, 33D ... support part (restriction) ,..., Small diameter portion, 34, driven rod, 341, shaft portion, 342, engagement portion, 343, anchor, 35, support portion (an example of a limiting portion), 351, small diameter portion, 40, housing, DESCRIPTION OF SYMBOLS 41 ... Opening part, 42 ... Cover, 43 ... Housing recessed part, 50 ... Actuator, 51 ... Internal space, 52 ... Cylinder, 521 ... 1st flow path, 522 ... 2nd flow path, 53 ... Drive rod, 531 ... Shaft 532 ... Piston, 54 ... Compressor, 55 ... Solenoid valve, 56 ... First detection part, 57 ... Second detection part, 60 ... Connection part, 61 ... Body part, 611 ... Recess, 612 ... First engagement Hole 613 ... 2nd engagement hole 62 ... clamping part 63 ... fixing member 70 ... holder (an example of a closed space forming member) 71 ... cylindrical part 711 ... flow path 721 ... engagement groove 72 ... Cylindrical part, 80 ... Actuator, 81 ... Pressure reducing part (an example of pressure adjusting part), 82 ... Solenoid valve (an example of pressure adjusting part), 83 ... Pressure detecting part, CS ... Closed space, D1 ... First direction, D2 ... 2nd direction, D3 ... 3rd direction, M1 ... 1st moving direction, M2 ... 2nd moving direction, P1, P2 ... Connection part, W ... Workpiece | work.

Claims (8)

A movable part that reciprocates in a second movement direction that is opposite to the first movement direction and the first movement direction by the action of an external force;
A plurality of arms having elasticity and extending from the movable part;
In the arm, a limiting portion that restricts displacement in the first movement direction of a portion between a proximal end portion connected to the movable portion and a distal end portion on the opposite side thereof, and
When the base end portion is displaced in the first movement direction together with the movable portion, the plurality of arms have the portion where the displacement is restricted by the restriction portion as a fulcrum, and the distal ends are separated from the open position. A gripping hand whose tips move toward the closed position where they approach each other. The gripping hand according to claim 1, wherein when an external force does not act on the movable portion, the plurality of arms are arranged at the open position. The gripping hand according to claim 1, wherein when an external force does not act on the movable portion, the plurality of arms are arranged at the closed position. The plurality of arms are formed integrally with the movable part,
The gripping hand according to any one of claims 1 to 3, wherein a cross-sectional area perpendicular to a direction in which the arm extends at the base end portion of the arm gradually decreases toward the movable portion. The limiting portion has elasticity and is formed integrally with the arm so as to extend in a direction intersecting the arm,
5. The cross-sectional area perpendicular to the extending direction of the restricting portion at the end portion of the restricting portion connected to the arm gradually decreases toward the arm. 5. Gripping hand. The gripping hand according to any one of claims 1 to 5, wherein a cross-sectional area perpendicular to the extending direction of the arm gradually decreases toward the tip of the arm at the tip of the arm. The grasping hand according to any one of claims 1 to 6, wherein a space is formed between the movable portion and the plurality of arms arranged at the closed position. The movable portion has a circular cross-sectional shape orthogonal to the first movement direction,
The gripping hand according to any one of claims 1 to 7, wherein the plurality of arms are provided at equal intervals in a circumferential direction of the movable part.