Gripping device

Abstract

The gripping device (2) according to the present invention is provided with: a pair of gripping claws (4) that grip or release a workpiece (W) by performing an opening / closing operation; an opening / closing mechanism (6) that moves the gripping claws (4) in an opening / closing direction; and a rotation mechanism (14) that rotates the gripping claws (4) about an axis (AX1) of an oscillating rotation shaft (8) parallel to the opening / closing direction. The opening / closing mechanism (6) has a linear motion element (10) to which the gripping claws (4) are connected and which moves in the opening / closing direction. The rotation mechanism (14) has: an oscillating rotation drive source (16) that rotationally drives the gripping claws (4) about the axis (AX1) of the oscillating rotation shaft (8); and a link part (18) that is connected to at least one gripping claw (4) and transmits the power of the oscillating rotation drive source (16) to the gripping claw (4).

Description

gripping device Related Applications

[0001] This application claims priority from Japanese Patent Application No. 2024-147609, filed August 29, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a gripping device for gripping a workpiece such as a mechanical part or an electronic part.

[0003] For example, Patent Documents 1 and 2 describe a gripping device that is installed at the tip of an articulated robot or the like, grips a workpiece by opening and closing in a linear direction, and changes the posture of the workpiece while still gripping it. With such a gripping device, the posture of the workpiece can be changed while still gripping it, which allows the robot's operating space to be increased and the time required for operation to be reduced.

[0004] Patent No. 5408186 Patent No. 5617512

[0005] However, in gripping devices such as those disclosed in Patent Documents 1 and 2, the power for changing the position of the workpiece is transmitted via pulleys and a belt. Using a belt as a power transmission member can lead to slippage, requiring measures to prevent this. Furthermore, there is concern that wear and deterioration of the belt can shorten the life of the device.

[0006] An object of the present invention is to provide a gripping device that can achieve a long life for the device.

[0007] The gripping device of the present invention includes a pair of gripping jaws that grip or release a workpiece by opening and closing them, an opening / closing mechanism that moves the gripping jaws in an opening / closing direction, and a rotation mechanism that rotates the gripping jaws around the axis of a swinging rotation shaft that is parallel to the opening / closing direction. The opening / closing mechanism has a linear motion element to which the gripping jaws are connected and which moves in the opening / closing direction. The rotation mechanism includes an swinging rotation drive source that rotates the gripping jaws around the axis of the swinging rotation shaft, and a link unit that is connected to at least one of the gripping jaws and transmits the power of the swinging rotation drive source to the gripping jaws. The link unit is made up of a link mechanism in which multiple members are rotatably connected by multiple joints.

[0008] With this configuration, the rotation of the swing rotation drive source is transmitted to the gripping jaws via a link mechanism. This eliminates the need to consider belt slippage and related design factors. Furthermore, the absence of belt wear and deterioration extends the life of the device.

[0009] In the present invention, the link unit includes a first link mechanism, the first link mechanism including a first input crank member connected at one end to the output shaft of the rotation mechanism and rotatable about the output shaft, a first link member connected at one end to the other end of the first input crank member, and a first output crank member connected at one end to the other end of the first link member and at the other end to the swing rotation shaft and rotatable about the swing rotation shaft, the first input crank member and the first output crank member being parallel and of equal length. This configuration allows the parallel link to transmit rotation of the swing rotation drive source to the gripping jaws with a simple configuration. Furthermore, by making the first output crank member small, the radius of rotation of the end of the device, i.e., the tip, can be made compact. The compact radius of rotation of the tip allows for gripping of small workpieces.

[0010] In the present invention, the link section may further include a second link mechanism, the second link mechanism having a second input shaft different from the output shaft of the rotation mechanism constituting the first input shaft, and a second output shaft different from the oscillating rotation shaft constituting the first output shaft, configured to transmit rotation of the second input shaft to the second output shaft, the first input shaft and the second input shaft being connected via a first gear pair, and the first output shaft and the second output shaft being connected via a second gear pair. Instead of gears, power transmission elements such as magnetic gears, pulleys, etc. may be used.

[0011] In this case, the first gear pair may have a first input gear and a second input gear that mesh with each other, the second gear pair may have a first output gear and a second output gear that mesh with each other, the first input gear may be non-rotatably mounted on the first input shaft, the second input gear may be non-rotatably mounted on the second input shaft, the first output gear may be non-rotatably mounted on the first output shaft, and the second output gear may be non-rotatably mounted on the second output shaft. Furthermore, the second link mechanism may have a second input crank member connected at one end to the second input shaft and rotatable about the second input shaft, a second link member connected at one end to the other end of the second input crank member, and a second output crank member connected at one end to the other end of the second link member and the other end to the second output shaft and rotatable about the second output shaft, and the second input crank member and the second output crank member may be parallel and have the same length.

[0012] According to this configuration, a second link mechanism is provided with an input shaft and an output shaft different from those of the first link mechanism, and the input shafts and output shafts of the first link mechanism and the second link mechanism are rotated via gear pairs. This offsets the rotational cycles of the two link mechanisms, making it less likely that an unstable state will occur at the same time. As a result, system redundancy is improved and power is transmitted stably to the gripping jaws.

[0013] When two link mechanisms are provided, the gear ratio of the first gear pair and the gear ratio of the second gear pair may each be 1:1. According to this configuration, the two link mechanisms are connected at a gear ratio of 1:1. This allows the entire link unit to be configured compactly, for example, by using two small-diameter gears. Furthermore, for example, by connecting the two link mechanisms with a phase shift, the two link mechanisms rotate with a gear ratio of 1:1, preventing the two link mechanisms from becoming unstable at the same time.

[0014] In the present invention, the device may further include an extendable rotation mechanism that is extendable in the opening and closing direction and that transmits rotation of the oscillating rotation drive source to the link portion. In this case, the extendable rotation mechanism may include a first rotation shaft connected to the output shaft of the oscillating rotation drive source, a second rotation shaft that constitutes a first input shaft connected to an input-side crank member of the link portion, and an extendable rotation structure that transmits rotation of the first rotation shaft to the second rotation shaft and supports the second rotation shaft so that it can move relative to the first rotation shaft in the gripping direction and the releasing direction.

[0015] Furthermore, the telescopic rotating structure may have a long gear provided on one of the first rotating shaft and the second rotating shaft, the long gear having an axial dimension longer than the opening / closing width of the opening / closing mechanism, and a short gear provided on the other of the first rotating shaft and the second rotating shaft, meshing with the long gear to transmit the rotation of the long gear and movable relative to the long gear in the opening / closing direction.

[0016] With this configuration, the oscillating rotation drive source and the link part are connected via the telescopic rotation mechanism, so only the gripping claws and the link part move in the opening and closing direction together with the linear motion element, and the oscillating rotation drive source does not move. As a result, the load in the opening and closing direction is reduced, enabling high-speed operation of the rotation mechanism.

[0017] In the case where the telescopic rotation mechanism is provided, the output shaft of the telescopic rotation mechanism may be supported by the linear motion element by a plain bearing. With this configuration, the plain bearing reduces resistance to the extension and contraction and rotation of the output shaft of the telescopic rotation mechanism.

[0018] In the present invention, the opening / closing mechanism and the rotation mechanism may be detachably fixed via a connecting member. With this configuration, the opening / closing mechanism can be detached from the rotation mechanism, making it easy to replace the opening / closing mechanism. This makes it possible to handle workpieces of various shapes, increasing the versatility of the device.

[0019] In the present invention, the opening / closing mechanism may have an opening / closing drive source that moves the linear motion element in the opening / closing direction. In this case, the opening / closing drive source may be a pneumatic parallel chuck, and the swinging / rotating drive source may be a motor. With this configuration, the swinging / rotating drive source and the opening / closing drive source can operate independently. This allows for separate control of the opening / closing operation of the linear motion element and the swinging operation of the gripping jaws.

[0020] In the present invention, one of the pair of gripping claws may be moved in the opening / closing direction by the opening / closing mechanism, and the other of the pair of gripping claws may be fixed so as not to move in the opening / closing direction. With this configuration, the gripping claw on the link part side does not move in the opening / closing direction but only performs a swinging motion, and only the gripping claw on the passive side (non-link part side) moves in the opening / closing direction. This eliminates the need for an extension / retraction rotation mechanism, allowing the number of parts to be reduced.

[0021] Any combination of at least two features disclosed in the claims and / or the specification and / or the drawings is included in the present invention. In particular, any combination of two or more of the claims is included in the present invention.

[0022] The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are merely for illustration and explanation purposes and should not be used to define the scope of the present invention. The scope of the present invention is defined by the accompanying claims. In the accompanying drawings, the same part numbers in multiple drawings indicate the same or corresponding parts.

[0023] Fig. 1 is a perspective view showing a gripping device according to a first embodiment of the present invention. Fig. 2 is a plan view showing the gripping device. Fig. 3 is a side view showing the gripping device. Fig. 4 is a side view showing a link section of the gripping device. Fig. 5 is a front view showing an extension and contraction rotation mechanism of the gripping device. Fig. 6 is a perspective view showing a gripping device according to a second embodiment of the present invention. Fig. 7 is a plan view showing the gripping device. Fig. 8 is a side view showing a link section of the gripping device. Fig. 9 is a perspective view showing a gripping device according to a third embodiment of the present invention. Fig. 10 is a plan view showing the gripping device.

[0023]

[0023] Preferred embodiments of the present invention will now be described with reference to the drawings. Fig. 1 is a perspective view of a gripping device 2 according to a first embodiment of the present invention, Fig. 2 is a plan view of the gripping device 2, and Fig. 3 is a side view of the gripping device 2.

[0024] [Basic Configuration of Grip Device] The grip device 2 shown in Fig. 1 is attached to the tip of a robot as an end effector, for example. Specifically, the grip device 2 is rotated by the robot to grip (pick up) the workpiece W. The robot is, for example, a horizontal articulated robot with multiple arms that move horizontally. However, the robot is not limited to a horizontal articulated robot, and any working robot can be applied.

[0025] The workpieces W (FIG. 2) are, for example, mechanical parts, electronic parts, plastic parts, medicines, medical supplies, food, miscellaneous goods, etc. Each workpiece W has a different position, posture, and opening / closing amount suitable for gripping.

[0026] The gripping device 2 has a pair of gripping jaws 4 that grip or release the workpiece W by opening and closing, and an opening and closing mechanism 6 that moves the gripping jaws 4 in the opening and closing direction. In other words, the gripping device 2 is provided with a pair of gripping jaws 4 and an opening and closing mechanism 6 that have a shape suitable for gripping the workpiece W.

[0027] 2, in this embodiment, the workpiece W is gripped by the gripping jaws 4 by closing the opening / closing mechanism 6 (by moving in the closing direction). That is, in this embodiment, the gripping direction DR1 for gripping the workpiece W is the closing direction, and the release direction DR2 for releasing the workpiece W is the opening direction. In the following description, the gripping direction DR1 is referred to as the closing direction DR1, the release direction DR2 is referred to as the opening direction DR2, and the "gripping direction and release direction" are referred to as the "opening / closing direction D1."

[0028] The gripping device 2 changes the posture of the gripped workpiece W by oscillating and rotating the gripping jaws 4 while gripping the workpiece W. The gripping jaws 4 rotate about an axis AX1 of an oscillating rotation shaft 8 that is parallel to the opening / closing direction D1. More specifically, the gripping device 2 is equipped with a rotation mechanism 14 that rotates the gripping jaws 4 about the axis AX1 of the oscillating rotation shaft 8. In this way, by providing the rotation mechanism 14 on the end effector and providing a function for changing the posture of the workpiece W, it is possible to rotate (change the posture) the workpiece W without moving the robot.

[0029] [Opening / Closing Mechanism] The opening / closing mechanism 6 has a pair of linearly moving elements 10 that move in the opening / closing direction D1, and an opening / closing drive source 12 that moves the linearly moving elements 10. The opening / closing mechanism 6 of this embodiment linearly moves the two linearly moving elements 10 symmetrically in two directions. In other words, with respect to the opening / closing direction D1, the closing direction DR1 and the opening direction DR2 of one linearly moving element 10 and the other linearly moving element 10 are opposite to each other.

[0030] The opening / closing drive source 12 is housed inside the housing 6a of the opening / closing mechanism 6. The opening / closing drive source 12 is, for example, an air cylinder driven by compressed air, i.e., a pneumatic parallel chuck. However, the opening / closing drive source 12 is not limited to this and may be a hydraulic actuator, an electric motor, or the like. In this embodiment, one opening / closing drive source 12 drives two linear motion elements 10. However, each linear motion element 10 may be provided with an opening / closing drive source 12.

[0031] The linear motion element 10 of this embodiment is a long, thin plate-like member, and is supported at its base end 10a so as to be movable in the opening and closing direction D1 relative to the housing 6a of the opening and closing mechanism 6. The gripping claws 4 are connected to the tip end 10b of the linear motion element 10.

[0032] [Gripping Claws] The gripping claws 4 of this embodiment have a power-side gripping claw 4a that rotates around the axis AX1 of the oscillating rotation shaft 8 and a driven-side gripping claw 4b that does not rotate relative to the linear motion element 10. In other words, the driven-side gripping claw 4b is fixed so as not to be able to rotate relative to the linear motion element 10. In this embodiment, the gripping surface 4ba of the driven-side gripping claw 4b is a flat surface that is perpendicular to the axis AX1 of the oscillating rotation shaft 8.

[0033] The power side gripping jaws 4a not only move linearly in the opening / closing direction D1 by the linear motion element 10, but also rotate about an axis AX1 by the oscillating rotation shaft 8. The oscillating rotation shaft 8 penetrates the linear motion element 10 in the opening / closing direction D1 and is rotatably supported by the linear motion element 10 via, for example, a rolling bearing. The oscillating rotation shaft 8 may be supported by a bearing other than a rolling bearing, or may be a sliding bearing. The gripping surface 4aa of the power side gripping jaws 4a has a shape that follows the shape of the workpiece W.

[0034] When the linear motion element 10 of the opening / closing mechanism 6 operates in the closing direction DR1 and the gripping jaws 4 are pressed against the workpiece W, the workpiece W is gripped by the gripping jaws 4. At this time, the workpiece W fits into the gripping surface 4aa of the power-side gripping jaws 4a. In this state, when the power-side gripping jaws 4a rotate, the workpiece W rotates on the gripping surface 4ba of the driven-side gripping jaws 4b.

[0035] [Rotation Mechanism] The gripping device 2 further includes a rotation mechanism 14 that rotates the gripping jaws 4 around the axis AX1 of the oscillating rotation shaft 8. The rotation mechanism 14 has an oscillating rotation drive source 16 that drives the gripping jaws 4 to rotate, and a link unit 18 that transmits the power of the oscillating rotation drive source 16 to the gripping jaws 4. Details of the link unit 18 will be described later.

[0036] The swing rotation drive source 16 is, for example, a motor. The swing rotation drive source 16 is not limited to a motor, and may be, for example, a structure that uses a spring to rotate mechanically, a structure that uses air pressure such as an air cylinder, or a structure that uses hydraulic pressure such as a hydraulic actuator. When a motor is used as the swing rotation drive source 16, the posture of the workpiece W can be easily changed to any inclination compared to air pressure or hydraulic pressure.

[0037] The opening / closing drive source 12 of the opening / closing mechanism 6 and the swinging rotation drive source 16 of the rotation mechanism 14 are provided separately and operate independently. For example, the opening / closing drive source 12 and the swinging rotation drive source 16 may have different structures, such as a structure in which the opening / closing drive source 12 uses air pressure and a structure in which the swinging rotation drive source 16 uses electricity, or they may have the same structure.

[0038] The oscillating rotation drive source 16 is housed in the housing 14a of the rotation mechanism 14, and the housing 14a of the rotation mechanism 14 is fixed to the housing 6a of the opening / closing mechanism 6. In other words, the oscillating rotation drive source 16 of the rotation mechanism 14 does not move in the opening / closing direction D1 together with the linear motion element 10 of the opening / closing mechanism 6. This reduces the load in the opening / closing direction D1, allowing the opening / closing mechanism 6 to operate at high speed. Furthermore, because the only objects rotated by the power of the oscillating rotation drive source 16 via the link portion 18 and (described later) are the workpiece W and the gripping jaws 4, the moment of inertia is small, allowing for high-speed rotation.

[0039] [Extendable Rotation Mechanism] The gripping device 2 of this embodiment further includes an extendable rotation mechanism 20 that is extendable in the opening / closing direction D1 and transmits the rotation of the swing rotation drive source 16 to the link portion 18.

[0040] The telescopic rotation mechanism 20 has a first rotation shaft 22 connected to the output shaft 16a of the swing rotation drive source 16, a second rotation shaft 24 connected to the input shaft 18a (described later) of the link portion 18, and an telescopic rotation structure 26 connecting the first rotation shaft 22 and the second rotation shaft 24. The telescopic rotation structure 26 transmits the rotation of the first rotation shaft 22 to the second rotation shaft 24, and supports the second rotation shaft 24 relative to the first rotation shaft 22 so that the second rotation shaft 24 can move in the opening / closing direction D1.

[0041] The first rotating shaft 22 and the second rotating shaft 24 are configured to be capable of translating relative to each other in the opening / closing direction D1 and to be able to transmit rotation at any position during the translation. In other words, the first rotating shaft 22 and the second rotating shaft 24 are capable of extending and contracting in the operating direction of the opening / closing mechanism 6 (opening / closing direction D1) and are rotatable about a rotation axis parallel to the opening / closing direction D1.

[0042] As described above, the rotation mechanism 14 of this embodiment comprises a fixed side that is fixed to the opening / closing mechanism 6 by the telescopic rotation mechanism 20, and a movable side that is movable in the operating direction (opening / closing direction D1) of the opening / closing mechanism 6. The fixed side of the rotation mechanism 14 is fixed to the housing 6a of the opening / closing mechanism 6, and includes the swing rotation drive source 16, the housing 14a, the telescopic rotation mechanism 20, etc. The movable side of the rotation mechanism 14 is fixed to the linear motion element 10 of the opening / closing mechanism 6, and includes the link portion 18.

[0043] [Telescopic Rotation Structure] The telescopic rotation structure 26 of this embodiment will be described in detail with reference to Fig. 5. The telescopic rotation structure 26 of this embodiment has a short gear 28 provided on the first rotation shaft 22 and a long gear 30 provided on the second rotation shaft 24.

[0044] The axial dimension of the long gear 30 is set longer than the opening / closing width of the opening / closing mechanism 6 (FIG. 2), i.e., the amount of movement in the opening / closing direction D1. The short gear 28 meshes with the long gear 30 to transmit the rotation of the long gear 30 and is movable relative to the long gear 30 in the opening / closing direction D1.

[0045] The first rotation shaft 22 and the short gear 28 of the telescopic rotation structure 26 are rotatable around the rotation axis AX2 of the oscillating rotation drive source 16 relative to the housing 14a of the rotation mechanism 14. Furthermore, the first rotation shaft 22 and the short gear 28 do not move in the opening / closing direction D1.

[0046] When the long gear 30 meshes with the short gear 28, the rotation of the short gear 28 is transmitted to the long gear 30 and the second rotating shaft 24, and the long gear 30 and the second rotating shaft 24 can move in the opening / closing direction D1 (axial direction).

[0047] The short gear 28 and the long gear 30 are housed inside a gear case 32 shown in Fig. 2. The gear case 32 is fixed to a housing 6a of the opening / closing mechanism 6. In addition, a housing 14a of the rotation mechanism 14 is fixed to the gear case 32. In other words, the rotation mechanism 14 is fixed to the opening / closing mechanism 6 via the gear case 32.

[0048] The second rotation shaft 24, which is the output shaft of the telescopic rotation mechanism 20, is connected to the input shaft 18a of the link unit 18. The input shaft 18a of the link unit 18 rotates integrally with the second rotation shaft 24 of the telescopic rotation mechanism 20. The input shaft 18a of the link unit 18 is supported by the linear motion element 10 so as to be rotatable and movable in the axial direction (opening / closing direction D1). In other words, the output shaft (second rotation shaft 24) of the telescopic rotation mechanism 20 is supported by the linear motion element 10 via the input shaft 18a of the link unit 18.

[0049] According to the configuration of Fig. 5, rotation of the oscillating rotation drive source 16 causes the first rotating shaft 22 and the short gear 28 to rotate around the rotation axis AX2, and meshing of the gears 28, 30 causes the long gear 30 and the second rotating shaft 24 to rotate. Furthermore, meshing of the short gear 28 and the long gear 30 causes the long gear 30 and the second rotating shaft 24 to move in a direction parallel to the opening / closing direction D1 in accordance with the opening and closing operation of the opening / closing mechanism 6 of Fig. 2. Therefore, even when the opening / closing mechanism 6 is opened or closed, rotational power can be transmitted to the gripping jaws 4. Thus, according to the example of Fig. 5, with a small number of parts, rotational torque can be reliably transmitted in the rotational direction, and linear movement in the extension / contraction direction (opening / closing direction D1) is possible.

[0050] 5, the second rotating shaft 24 is provided with a long gear 30 having a long axial dimension, and the first rotating shaft 22 is provided with a short gear 28, but the first rotating shaft 22 may be provided with a long gear 30 having a long axial dimension, and the second rotating shaft 24 may be provided with a short gear 28. Furthermore, the telescopic rotation mechanism 20 is not limited to the structure of the embodiment as long as it is configured to be able to transmit the rotation of the swing rotation drive source 16 to the gripping jaws 4 and to allow the gripping jaws 4 to move in the opening / closing direction D1.

[0051] [Link Section] The link section 18 of this embodiment will be described in detail with reference to Figures 2 to 4. In this embodiment, the link section 18 transmits power from the drive source and realizes the functions of opening, closing, and rotating at a distance. Specifically, the rotation of the swing rotation drive source 16 is transmitted to the swing rotation shaft 8. The link section 18 is made up of a link mechanism that forms a closed circuit in which multiple members are rotatably connected by multiple joints. In this embodiment, a parallel link mechanism is used as the link section 18. A link mechanism does not require a belt, and there is no need to consider slippage or wear. Furthermore, the link mechanism makes it easier to adjust the distance than gears, and there is no need to consider backlash.

[0052] The link unit 18 of this embodiment has one parallel link mechanism (first link mechanism 36). As shown in Fig. 2, the first link mechanism 36 has a first input crank member 38, a first link member 40, and a first output crank member 42. The first input crank member 38 and the first output crank member 42 are parallel to each other and have the same length.

[0053] As shown in Fig. 4, the first input crank member 38 is made of a long, thin plate material, and is connected at one end 38a to the input shaft 18a of the link unit 18 and rotates around the input shaft 18a. In other words, as shown in Fig. 2, the first input crank member 38 is connected at one end 38a to the output shaft (second rotation shaft 24) of the telescopic rotation mechanism 20 via the input shaft 18a of the link unit 18 and rotates around the output shaft (second rotation shaft 24).

[0054] 4, the first link member 40 is made of a long, thin plate, and one end 40a is rotatably connected to the other end 38b of the first input crank member 38. More specifically, the other end 38b of the first input crank member 38 and one end 40a of the first link member 40 are connected by a first link shaft 44 shown in FIG.

[0055] 4, the first output crank member 42 is made of a long, thin plate, and has one end 42a rotatably connected to the other end 40b of the first link member 40, and the other end 42b connected to the oscillating rotation shaft 8, so as to rotate around the oscillating rotation shaft 8. More specifically, the other end 40b of the first link member 40 and one end 42a of the first output crank member 42 are connected by a second link shaft 46 shown in FIG.

[0056] As described above, the linear motion element 10 and the first input crank member 38 are rotatably connected at a joint portion via the input shaft 18a of the link portion 18, the first input crank member 38 and the first link member 40 are rotatably connected at a joint portion via the first link shaft 44, the first link member 40 and the first output crank member 42 are rotatably connected at a joint portion via the second link shaft 46, and the first output crank member 42 and the linear motion element 10 are rotatably connected at a joint portion via the oscillating rotation shaft 8. In other words, the link portion 18 constitutes a closed circuit in which a plurality of members 10, 38, 40, 42 are rotatably connected at a joint portion.

[0057] A reducing member that reduces rotational resistance may be provided at the connection between the first link member 40 and each link shaft 44, 46. The reducing member is, for example, a rolling bearing. However, the reducing member is not limited to this and may be a bearing other than a rolling bearing or a member other than a bearing. By providing the reducing member, the life of the first link member 40 and the link shafts 44, 46 and the transmission efficiency of the link portion 18 are improved.

[0058] In this embodiment, the power of the oscillating rotation drive source 16 is supplied to only one of the two gripping claws 4, specifically the power side gripping claw 4a, via the link portion 18, but it may also be supplied to both gripping claws 4.

[0059] [Operation] Next, the operation of the gripping device 2 of this embodiment will be described. When the gripping device 2 grips the workpiece W, the opening and closing drive source 12 is driven to move the linear motion element 10, the link portion 18 fixed thereto, and the gripping jaws 4 in the gripping direction DR1. At this time, the swinging rotation drive source 16 fixed to the housing 6a of the opening and closing mechanism 6 and the first rotation shaft 22 of the extension and contraction rotation mechanism 20 connected to the swinging rotation drive source 16 do not move in the gripping direction DR1.

[0060] On the other hand, in the telescopic rotation mechanism 20, the second rotation shaft 24, which is connected to the first rotation shaft 22 via the telescopic rotation structure 26 so as to be freely movable in the opening / closing direction D1, moves in the gripping direction DR1 by the input shaft 18a of the link portion 18.

[0061] When the oscillating rotation drive source 16 is driven while the gripping jaws 4 are gripping the workpiece W, the first rotating shaft 22 and the short gear 28 shown in Fig. 5 rotate. When the short gear 28 rotates, the long gear 30 and the second rotating shaft 24 that mesh with it rotate.

[0062] When the second rotating shaft 24 rotates, the link unit 18 connected thereto rotates. Specifically, the first input side crank member 38 in FIG. 4 rotates around the second rotating shaft 24, and the first output side crank member 42 connected thereto via the first link member 40 rotates around the oscillating rotating shaft 8. When the link unit 18 rotates, the oscillating rotating shaft 8 connected to the first output side crank member 42 also rotates. When the oscillating rotating shaft 8 rotates, the power side gripping jaws 4a connected thereto rotate, and the workpiece W rotates around the rotation axis AX1. This allows the posture of the workpiece W to be changed.

[0063] When the gripping device 2 releases the workpiece W, the opening / closing drive source 12 is driven to move the linear motion element 10 and the gripping jaws 4 fixed thereto in the release direction DR2. At this time, similar to when gripping the workpiece W, the swinging rotation drive source 16 and the first rotation shaft 22 of the telescopic rotation mechanism 20 do not move in the release direction DR2, and the second rotation shaft 24 of the telescopic rotation mechanism 20 and the link portion 18 move in the release direction DR2.

[0064] [Effects] According to the above configuration, the rotation of the swing rotation drive source 16 is transmitted to the gripping jaws 4 via the link portion 18, which is made up of a link mechanism. The link mechanism does not transmit rotation through deformation or friction like a belt, so there is no slippage and less wear. Therefore, there is no need to consider design factors related to belt slippage. Furthermore, since there is no wear or deterioration of the belt, the life of the device can be extended. Furthermore, the link mechanism makes it easier to adjust the distance than gears, and there is no need to consider backlash.

[0065] In order to grip small workpieces, the gripping jaws 4 must also be small. However, the belt and pulley system has a fixed pulley size, and the gear system has a fixed gear size, so there is a limit to how small the size can be. By adopting a link mechanism as in this embodiment, it is easy to make the gripping jaws 4 small.

[0066] In this embodiment, a parallel link mechanism is used as the link portion 18. This configuration allows the rotation of the oscillating rotation drive source 16 to be transmitted to the gripping jaws 4 with a simple configuration. Furthermore, by making the first output crank member 42 small, the radius of rotation of the end of the device, i.e., the tip, can be made compact. By making the radius of rotation of the tip compact, small workpieces W can be gripped.

[0067] In this embodiment, after gripping the workpiece W, the gripping jaws 4 rotate the workpiece W, thereby changing the posture of the workpiece W without having to grip it again. This shortens the work time. In addition, there is no longer a need to rotate the robot arm to change the posture of the workpiece W, which also saves space.

[0068] According to the configuration of this embodiment, the gripping claws 4 are provided at the tip of the linear motion element 10 of the opening / closing mechanism 6, and the gripping claws 4 rotate the workpiece W around the rotation axis AX1. Therefore, by replacing the gripping claws 4, it is possible to accommodate workpieces W of various shapes. In addition, by replacing the linear motion element 10 and the first link member 40, it is possible to accommodate workpieces W of various sizes.

[0069] In this embodiment, the swinging and rotating drive source 16 and the link portion 18 are connected via an extension and contraction rotation mechanism 20. Therefore, only the gripping jaws 4 and the link portion 18 move in the opening and closing direction D1 together with the linear motion element 10, and the swinging and rotating drive source 16 does not move. Therefore, the load in the opening and closing direction D1 is reduced, and the opening and closing mechanism 6 can operate at high speed.

[0070] Furthermore, because only the gripping jaws 4 are rotated, rather than the entire linear motion element 10, the only objects that rotate are the workpiece W and the gripping jaws 4, reducing the weight and moment of inertia of the objects that rotate. As a result, high-speed rotation of the gripping jaws 4 and low torque of the oscillating rotation drive source 16 are possible, allowing for a reduction in the size and weight of the oscillating rotation drive source 16.

[0071] Next, a gripping device according to another embodiment will be described. In the following description, the same components as those in the preceding embodiment will be assigned the same reference numerals, and detailed description thereof will be omitted. Unless otherwise specified, the components of any embodiment can be applied to other embodiments.

[0072] Second Embodiment Figures 6 and 7 are a perspective view and a plan view of a gripping device 2A according to a second embodiment of the present invention. Figures 8 and 9 are a side view and a perspective view of a link portion 18A of the gripping device 2A. In the second embodiment shown in Figure 7, the link portion 18A is provided with a second link mechanism 48 as a countermeasure against an unstable state of the parallel link. Also, in the second embodiment, the opening / closing mechanism 6A has only one linear motion element 10. Details are described below.

[0073] [Opening and Closing Mechanism] In the second embodiment, the opening and closing mechanism 6A has only one linear motion element 10, and the driven-side gripping claw 4b is fixed to the tip of the linear motion element 10. The power-side gripping claw 4a is fixed to the housing 6Aa of the opening and closing mechanism 6A via a base member 50. The base member 50 is made of an elongated plate material, and is fixed at an intermediate portion in the longitudinal direction to the housing 6Aa of the opening and closing mechanism 6A, with the power-side gripping claw 4a operably supported at one end 50a in the longitudinal direction.

[0074] That is, one of the pair of gripping claws 4 (driven-side gripping claw 4b) is moved in the opening / closing direction D1 by the opening / closing mechanism 6A, while the other (power-side gripping claw 4a) is fixed so as not to move in the opening / closing direction D1. In addition, a link portion 18A (described later) is also fixed to the housing 6Aa of the opening / closing mechanism 6A via a base member 50, so that the power-side gripping claw 4a only oscillates and rotates, and only the driven-side gripping claw 4b moves linearly. This eliminates the need for the telescopic rotation mechanism 20 as in the first embodiment, reducing the number of components.

[0075] [Link Section] As described above, in the second embodiment, the link section 18A includes a second link mechanism 48 in addition to the first link mechanism 36. The second link mechanism 48 has an input shaft and an output shaft different from those of the first link mechanism 36, and rotation is transmitted between the input shafts and the output shafts of the first link mechanism 36 via transmission elements. In the illustrated example, gears of different sizes are used as the transmission elements. By setting a gear ratio between the gears, the rotation periods of the two link mechanisms 36, 48 are shifted, making it less likely that an unstable state will occur at the same time. This is described in detail below.

[0076] The second link mechanism 48 has a second input shaft 52 different from the first input shaft 18a of the first link mechanism 36, and a second output shaft 54 ​​different from the first output shaft (oscillating rotation shaft 8) of the first link mechanism 36. In this embodiment, the output shaft 16a of the oscillating rotation drive source 16 of the rotation mechanism 14 constitutes the first input shaft 18a of the first link mechanism 36. The second link mechanism 48 is configured to transmit rotation of the second input shaft 52 to the second output shaft 54.

[0077] The first input shaft 18a of the first link mechanism 36 and the second input shaft 52 of the second link mechanism 48 are rotatably supported on the other end 50b of the base member 50. In the illustrated example, the first input shaft 18a is disposed on the other end side (outside), and the second input shaft 52 is disposed on the housing 6Aa side (inside) of the opening / closing mechanism 6A.

[0078] The first output shaft 8 of the first link mechanism 36 and the second output shaft 54 ​​of the second link mechanism 48 are rotatably supported on one end 50a of the base member 50. In the illustrated example, the first output shaft (swinging rotation shaft) 8 is disposed on the one end side (outside), and the second output shaft 54 ​​is disposed on the housing 6Aa side (inside) of the opening / closing mechanism 6A.

[0079] The first input shaft 18a of the first link mechanism 36 and the second input shaft 52 of the second link mechanism 48 are connected via a first gear pair 56. The first output shaft 8 of the first link mechanism 36 and the second output shaft 8 of the second link mechanism 48 are connected via a second gear pair 58.

[0080] The first gear pair 56 includes a first input gear 56a and a second input gear 56b that mesh with each other. The second gear pair 58 includes a first output gear 58a and a second output gear 58b that mesh with each other. The gear ratio between the first input gear 56a and the second input gear 56b and the gear ratio between the first output gear 58a and the second output gear 58b are set to predetermined values. The gear ratios may be, for example, a combination that ultimately cancels out the gear ratios. Specifically, the gear ratios may be 1:1 or an inverse ratio between the two gear pairs. Furthermore, from the perspective of compactness at the end, the gear ratio may be set so that the first output gear 58a is small.

[0081] The first input gear 56a is non-rotatably mounted on the first input shaft 18a of the first link mechanism 36. The second input gear 56b is non-rotatably mounted on the second input shaft 52 of the second link mechanism 48. The first output gear 58a is non-rotatably mounted on the first output shaft 8 of the first link mechanism 36. The second output gear 58b is non-rotatably mounted on the second output shaft 54 ​​of the second link mechanism 48.

[0082] The second link mechanism 48 further includes a second input crank member 60, a second link member 62, and a second output crank member 64. In this embodiment, the second input crank member 60 and the second output crank member 64 are set to be parallel and have the same length. In other words, the second link mechanism 48 is also a parallel link mechanism.

[0083] The second input crank member 60 is made of a long, thin plate material, and is connected at one end 60a to the second input shaft 52 to rotate around the second input shaft 52. The second input shaft 52 is provided with a second input gear 56b and is a shaft rotatably supported by the base member 50.

[0084] 8, the second link member 62 is made of a long, thin plate, and one end 62a is connected to the other end 60b of the second input crank member 60. More specifically, the other end 60b of the second input crank member 60 and one end 62a of the second link member 62 are rotatably connected by a third link shaft 66 shown in FIG.

[0085] 9, the second output crank member 64 is made of a long, thin plate, and has one end 64a rotatably connected to the other end 62b of the second link member 62, and the other end 64b connected to the second output shaft 54 ​​so as to rotate around the second output shaft 54. More specifically, the other end 62b of the second link member 62 and one end 64a of the second output crank member 64 are connected by a fourth link shaft 68 shown in FIG.

[0086] [Operation of Link Portion] When the oscillating rotation drive source 16 rotates, causing the input shaft 18a of the first link mechanism 36 to rotate, the input shaft 52 of the second link mechanism 48 also rotates due to the meshing of the first gear pair 56. As a result, the rotation of the input shaft 18a of the first link mechanism 36 is transmitted to the first output shaft 54 ​​of the first link mechanism 36 via the first input crank member 38, the first link member 40, and the first output crank member 42. At the same time, the rotation of the input shaft 52 of the second link mechanism 48 is transmitted to the second output shaft 54 ​​of the second link mechanism 48 via the second input crank member 60, the second link member 62, and the second output crank member 64.

[0087] The first output shaft 8 of the first link mechanism 36 and the second output shaft 54 ​​of the second link mechanism 48 are engaged with a second gear pair 58, and rotation is also transmitted between the output shafts 8, 54 via the second gear pair 58. Therefore, even if the first link mechanism 36 becomes unstable, the second link mechanism 48 transmits the rotation, and the first output shaft 8 of the first link mechanism 36 also rotates. As a result, the gripping jaws 4 oscillate and rotate, allowing the posture of the workpiece W to be changed.

[0088] In this embodiment, gears are used as transmission elements that transmit rotation between the input shafts of the two link mechanisms and between the output shafts of the two link mechanisms. However, the transmission elements are not limited to gears and may be, for example, pulleys / belts, magnetic couplings, etc. Furthermore, if a transmission element with a small diameter is selected at the end, the tip becomes smaller, allowing for gripping of smaller workpieces.

[0089] [Effects] In the second embodiment, as in the first embodiment, the power of the oscillating rotation drive source 16 is transmitted to the gripping jaws 4 via the link mechanisms 36, 48, eliminating wear and deterioration of the belt and achieving a long life for the device.

[0090] Furthermore, according to the second embodiment, a second link mechanism 48 having an input shaft and an output shaft different from those of the first link mechanism 36 is provided, and the input shafts 16a and 52 of the first link mechanism 36 and the second link mechanism 48 and the output shafts 8a and 54 of the first link mechanism 36 and the second link mechanism 48 are rotated via gear pairs 56 and 58. This offsets the rotational cycles of the two link mechanisms 36 and 48, making it less likely that an unstable state will occur at the same time. As a result, the redundancy of the system is improved, and power is transmitted stably to the gripping jaws 4.

[0091] Furthermore, one of the gripping claws 4 (driven-side gripping claw 4b) is moved in the opening / closing direction D1 by the opening / closing mechanism 6A, while the other of the gripping claws 4 (power-side gripping claw 4a) is fixed so as not to move in the opening / closing direction D1. In other words, the power-side gripping claw 4a connected to the link portion 18A does not move in the opening / closing direction D1 but only performs a swinging motion, and only the driven-side gripping claw 4b moves in the opening / closing direction D1. This eliminates the need for an extension / retraction rotation mechanism as in the first embodiment, reducing the number of parts and simplifying the device.

[0092] In the first embodiment, too, only one of the gripping claws 4 (the driven-side gripping claw 4b) can be made movable in the opening / closing direction D1 by the opening / closing mechanism 6, and the other of the gripping claws 4 (the power-side gripping claw 4a) can be made immovable in the opening / closing direction D1. This allows the telescopic rotation mechanism 20 to be omitted.

[0093] [Third Embodiment] Next, a gripping device 2B according to a third embodiment of the present invention will be described. Fig. 10 is a perspective view of the gripping device 2B, and Fig. 11 is a plan view of the gripping device 2B. Like the second embodiment, the third embodiment also includes two link mechanisms 36, 48. However, unlike the second embodiment, the opening / closing mechanism 6 in the third embodiment includes two linearly moving elements 10 that move in the opening and closing directions. Below, the configurations that differ from the first and second embodiments will be described in detail.

[0094] 11 is a pneumatic parallel chuck, and the swinging rotation drive source 16 is a motor. If the motor 16 is directly connected to the telescopic rotation mechanism 20, it will protrude significantly in the opening / closing direction D1 from the air chuck 12. Therefore, in the third embodiment, the rotation of the output shaft 16a of the motor 16 is transmitted to the input shaft 22 of the telescopic rotation mechanism 20 by a gear pair 69.

[0095] In detail, the gear pair 69 has an input gear 69a and an output gear 69b, the input gear 69a is provided on the output shaft 16a of the motor 16, the output gear 69b is provided on the input shaft 22 of the telescopic rotation mechanism 20, and the input gear 69a and the output gear 69b mesh with each other. The output shaft 16a of the motor 16 and the input shaft 22 of the telescopic rotation mechanism 20 extend from the gear pair 69 in the opening / closing direction D1 in the same direction (to the left in FIG. 11 ).

[0096] In the third embodiment, the opening / closing mechanism 6 and the rotation mechanism 14 are detachably fixed via a connecting member 70. In detail, the opening / closing mechanism 6 and the rotation mechanism 14 are each detachably fixed to the connecting member 70. This allows the opening / closing mechanism 6 or the rotation mechanism 14 to be easily removed alone.

[0097] In this embodiment, the gear case 70 of the telescopic rotation mechanism 20 constitutes the connecting member 70. The gear case 70 houses the short gear 28 and the long gear 30 that constitute the telescopic rotation structure 26.

[0098] [Gripping Claws] In the third embodiment, the driven-side gripping claws 4b are rotatably connected to the linear motion element 10. More specifically, a rotation shaft 72 extending in the opening / closing direction D1 is connected to the driven-side gripping claws 4b. The rotation shaft 72 passes through the linear motion element 10 and is rotatably supported by the linear motion element 10. In other words, the driven-side gripping claws 4b are rotatable around the rotation shaft 72. This reduces rotational resistance when rotating the workpiece W gripped by the gripping claws 4, enabling high-speed rotation. A bearing member such as a rolling bearing may be provided between the linear motion element 10 and the rotation shaft 72.

[0099] [Telescopic Rotation Mechanism] In the third embodiment, the first rotating shaft 22, which is the input shaft of the telescopic rotation mechanism 20, is supported by the linear motion element 10 via a plain bearing 75, and the second rotating shaft 24, which is the output shaft, is supported by the gear case 70 via a plain bearing 74. By supporting the first rotating shaft 22 with the plain bearing 75, the rotation and sliding in the axial direction (opening / closing direction D1) of the first rotating shaft 22 can be simply maintained.

[0100] Similarly, by supporting the second rotating shaft 24 with the sliding bearing 74, the rotation and sliding in the axial direction (opening / closing direction D1) of the second rotating shaft 24 can be easily maintained. In other words, the output shaft (second rotating shaft 24) of the telescopic rotation mechanism 20 is supported by the sliding bearing 74 so as to be rotatable relative to the swing rotation drive source 16 and movable in the axial direction (opening / closing direction D1). Supported by the sliding bearings 74, 75, the first rotating shaft 22 and the second rotating shaft 24 are kept parallel to each other, which reduces wear on the short gear 28 and the long gear 30 that make up the telescopic rotating structure 26 and improves their lifespan.

[0101] [Link Section] In the link section 18B of the third embodiment, the gear ratio of the first gear pair 56 and the gear ratio of the second gear pair 58 are each set to 1:1. By using two of the same smallest gears, the gear ratio is fixed to 1:1, allowing the link section 18B to be configured compactly. In addition, the two parallel link mechanisms 36, 48 are connected with a phase shift.

[0102] A characteristic of parallel link mechanisms is that power transmission becomes unstable when the link members and crank members are aligned in a line. If the mechanism is stopped in this state, the starting torque may become large.

[0103] In the third embodiment, the two parallel link mechanisms 36, 48 have a gear ratio of 1:1 and rotate with a phase shift. Therefore, it is unlikely that both link mechanisms 36, 48 will simultaneously become unstable. In other words, as in the third embodiment, when two parallel link mechanisms 36, 48 are present and the links are out of phase with each other, even if one link becomes unstable, the other link can operate without problem, improving system redundancy and enabling stable power transmission to the gripping jaws 4a.

[0104] [Effects] In the third embodiment, as in the first and second embodiments, the power of the oscillating rotation drive source 16 is transmitted to the gripping jaws 4 via the link mechanisms 36, 48, eliminating wear and deterioration of the belt and achieving a long life for the device.

[0105] Furthermore, according to the third embodiment, the gear ratio of the first gear pair 56 and the gear ratio of the second gear pair 58 are each 1:1, so that the entire link unit 18 can be configured compactly by using, for example, two small-diameter gears. Also, the two link mechanisms 36, 48 are connected with a phase shift. As a result, they rotate with a gear ratio of 1:1 while maintaining a phase shift, so the two link mechanisms 36, 48 do not simultaneously enter an unstable state.

[0106] In the third embodiment, the output shaft 24 of the telescopic rotation mechanism 20 is supported on the gear case 70 by a plain bearing 74. According to this configuration, the plain bearing 74 reduces resistance to the extension and contraction and rotation of the output shaft 24 of the telescopic rotation mechanism 20.

[0107] In the third embodiment, the opening / closing mechanism 6 and the rotation mechanism 14 are detachably fixed via a connecting member 70. With this configuration, only the opening / closing mechanism 6 or the rotation mechanism 14 can be removed, making it easy to replace the opening / closing mechanism 6 and the rotation mechanism 14. This makes it possible to handle workpieces of various shapes, increasing the versatility of the device.

[0108] In the third embodiment, the opening / closing drive source 12 is a pneumatic parallel chuck, and the oscillating / rotating drive source 16 is a motor. The drive sources 16 for the opening / closing mechanism 6 and the rotation mechanism 14 are provided independently. As a result, even if the height or shape of the workpiece W to be gripped is different, it is sufficient to replace the gripping jaws 4, the link portion 18, and the opening / closing mechanism 6, and there is no need to change the oscillating / rotating drive source 16. As a result, the length from the base of the gripping jaws 4 to the rotation axis 16a of the oscillating / rotating drive source 16 can be easily changed. Furthermore, by configuring the oscillating / rotating drive source 16 as a motor, the posture of the workpiece W can be easily changed to any inclination.

[0109] In the third embodiment, the output shaft 24 of the telescopic rotation mechanism 20 is supported on the gear case 70 by a plain bearing 74, but the output shaft 24 of the telescopic rotation mechanism 20 in the first embodiment may also be supported on the gear case 32 by a plain bearing 74. Furthermore, in the third embodiment, the opening / closing mechanism 6 and the rotation mechanism 14 are detachably fixed via the connecting member 70, but in the first and second embodiments, the opening / closing mechanism 6 and the rotation mechanism 14 may also be detachably fixed via the connecting member 70.

[0110] The present invention is not limited to the above-described embodiments, and various additions, modifications, and omissions are possible without departing from the spirit of the present invention. Therefore, such additions, modifications, and omissions are also included in the scope of the present invention.

[0111] 2, 2A, 2B: Grip device 4: Grip jaws 6, 6A: Opening / closing mechanism 8: Swinging rotation shaft (first output shaft) 10: Linear motion element 12: Opening / closing drive source 14: Rotation mechanism 16: Swinging rotation drive source 18, 18A, 18B: Link portion 20: Telescopic rotation mechanism 22: First rotation shaft 24: Second rotation shaft 26: Telescopic rotation structure 28: Short gear 30: Long gear 32: Gear case 36: First link mechanism 38: First input crank member 40: First link member 42: First output crank member 48: Second link mechanism 52: Second input shaft 54: Second output shaft 56: First gear pair 56a: First input gear 56b: Second input gear 58: Second gear pair 58a: First output gear 58b: Second output gear 60: Second input crank member 62: Second link member 64: Second output crank member 70: Connecting member (gear case) 74: Slide bearing, W: Work

Claims

1. A gripping device comprising: a pair of gripping claws that grip or release a workpiece by opening and closing; an opening and closing mechanism that moves the gripping claws in the opening and closing direction; and a rotation mechanism that rotates the gripping claws around the axis of an oscillating rotation shaft that is parallel to the opening and closing direction, wherein the opening and closing mechanism has a linear motion element to which the gripping claws are connected and which moves in the opening and closing direction, and the rotation mechanism has: an oscillating rotation drive source that drives the gripping claws to rotate around the axis of the oscillating rotation shaft; and a link section consisting of a link mechanism that is connected to at least one of the gripping claws and transmits the power of the oscillating rotation drive source to the gripping claws.

2. A gripping device according to claim 1, wherein the link section is a gripping device in which a plurality of members are rotatably connected by a plurality of joint sections.

3. A gripping device as described in claim 2, wherein the link section has a first link mechanism, the first link mechanism having: a first input crank member connected at one end to the output shaft of the rotation mechanism and rotating around the output shaft; a first link member connected at one end to the other end of the first input crank member; and a first output crank member connected at one end to the other end of the first link member and at the other end to the swing rotation shaft and rotating around the swing rotation shaft, wherein the first input crank member and the first output crank member are parallel and of equal length.

4. A gripping device according to claim 3, wherein the link section further comprises a second link mechanism, the second link mechanism comprising a second input shaft different from the output shaft of the rotation mechanism constituting the first input shaft, and a second output shaft different from the oscillating rotation shaft constituting the first output shaft, configured to transmit the rotation of the second input shaft to the second output shaft, the first input shaft and the second input shaft being connected via a first gear pair, and the first output shaft and the second output shaft being connected via a second gear pair.

5. In the gripping device described in claim 4, the first gear pair has a first input gear and a second input gear that mesh with each other, and the second gear pair has a first output gear and a second output gear that mesh with each other, the first input gear is non-rotatably mounted on the first input shaft, the second input gear is non-rotatably mounted on the second input shaft, the first output gear is non-rotatably mounted on the first output shaft, and the second output gear is non-rotatably mounted on the second output shaft, and the second link mechanism has: a second input crank member connected at one end to the second input shaft and rotating around the second input shaft; a second link member connected at one end to the other end of the second input crank member; and a second output crank member connected at one end to the other end of the second link member and connected at the other end to the second output shaft and rotating around the second output shaft, A gripping device in which the second input crank member and the second output crank member are parallel and have the same length.

6. A gripping device according to claim 5, wherein the gear ratio of said first gear pair and the gear ratio of said second gear pair are each 1:

1.

7. A gripping device according to any one of claims 1 to 6, further comprising an extension and retraction rotation mechanism that is extendable in the opening and closing direction and transmits the rotation of the swing rotation drive source to the link portion.

8. A gripping device as described in claim 7, wherein the telescopic rotation mechanism comprises: a first rotating shaft connected to the output shaft of the oscillating rotation drive source; a second rotating shaft constituting a first input shaft connected to the input side crank member of the link section; and a telescopic rotation structure which transmits the rotation of the first rotating shaft to the second rotating shaft and supports the second rotating shaft so that it can move relative to the first rotating shaft in the gripping direction and release direction.

9. A gripping device as described in claim 8, wherein the telescopic rotation structure has: a long gear provided on one of the first and second rotation shafts, the long gear having an axial dimension longer than the opening / closing width of the opening / closing mechanism; and a short gear provided on the other of the first and second rotation shafts, meshing with the long gear to transmit the rotation of the long gear and movable relative to the long gear in the opening / closing direction.

10. A gripping device according to claim 7, wherein the output shaft of the telescopic rotation mechanism is supported by the linear motion element through a sliding bearing.

11. A gripping device according to any one of claims 1 to 6, wherein the opening / closing mechanism and the rotation mechanism are detachably fixed via a connecting member.

12. A gripping device according to any one of claims 1 to 6, wherein the opening and closing mechanism has an opening and closing drive source that moves the linearly moving element in the opening and closing direction.

13. A gripping device according to claim 12, wherein the opening and closing drive source is a pneumatic parallel chuck.

14. A gripping device according to any one of claims 1 to 6, wherein the swinging and rotating drive source is a motor.

15. A gripping device as claimed in any one of claims 1 to 6, wherein one of the pair of gripping claws is moved in the opening and closing direction by the opening and closing mechanism, and the other of the pair of gripping claws is fixed so as not to be able to move in the opening and closing direction.

Images