Gripping device

Abstract

To provide a gripping device facilitating changing a length from a bottom of a claw to an oscillating rotary shaft even when a height of a workpiece as an object to be gripped in setup change is different.SOLUTION: A gripping device 6 includes: a plurality of claw parts 24 for gripping or releasing a workpiece W; a gripping part 22 for moving the claw parts 24 in an opening / closing direction; and a rotary mechanism 32 for rotating the workpiece W gripped by the claw parts 24 around a rotation axis in parallel to the opening / closing direction. The gripping part 22 has a gripping mechanism 26 attached with the claw parts 24 and moving in the opening / closing direction, and a first driving source 28 for moving the gripping mechanism 26 in the opening / closing direction. The rotary mechanism 32 has a rotary part 34 attached to each of the plurality of claw parts 24 and rotatable around the rotation axis to the claw parts 24, and a second driving source 36 attached to at least one of the claw parts 24 and rotationally driving the rotary part 34 around the rotation axis. The rotary mechanism 32 moves together with the claw parts 24 in the opening / closing direction.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] The present invention relates to a gripping device for gripping a workpiece such as a mechanical part or an electronic part. [Background technology]

[0002] In a hand installed at the tip of an articulated robot or the like, the claws are opened and closed in a linear direction to grasp a workpiece, and the posture of the workpiece can be changed while it is being grasped by the claws (for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5617512 [Patent Document 2] Patent No. 6029561 Summary of the Invention [Problem to be solved by the invention]

[0004] The hand of Patent Document 1 has a rotatable nut attached to a shaft extending in the opening and closing direction of the jaws, and rotation is transmitted to the jaws via this nut, causing the jaws to oscillate while gripping a workpiece. The hand of Patent Document 2 has a nut threadedly engaged with a ball screw extending in the opening and closing direction of the jaws, and rotation is transmitted to the jaws via this nut, causing the jaws to oscillate while gripping a workpiece. As such, the hands of Patent Documents 1 and 2 integrate a mechanism for gripping a workpiece with a mechanism for changing the posture of the gripped workpiece. Therefore, for example, if the height of the workpiece to be gripped changes during a setup change, it is not possible to easily change the length from the base of the jaws to the oscillating rotation axis.

[0005] An object of the present invention is to provide a gripping device that can easily change the length from the base of the jaws to the oscillating rotation axis even when the height of the workpiece to be gripped is different during setup change. [Means for solving the problem]

[0006] The gripping device of the present invention includes a plurality of jaws for gripping or releasing a workpiece, a gripping unit that moves the jaws in a gripping direction to grip the workpiece and a release direction to release the workpiece, and a rotation mechanism that rotates the workpiece gripped by the jaws around a rotation axis parallel to the gripping direction and the release direction. The gripping unit includes a gripping mechanism to which the jaws are attached and which moves in the gripping direction and the release direction, and a first drive source that moves the gripping mechanism in the gripping direction and the release direction. The rotation mechanism includes a rotating unit attached to each of the plurality of jaws and rotatable around the rotation axis relative to the jaws, and a second drive source attached to at least one of the jaws and driving the rotating unit to rotate around the rotation axis. The rotation mechanism moves together with the jaws in the gripping direction and the release direction.

[0007] According to this configuration, a rotating part of the rotation mechanism is separately provided at the tip of the claw attached to the gripping mechanism of the gripping unit, and the rotating part rotates the workpiece around a rotation axis parallel to the gripping and release directions of the claw. The gripping mechanism moves using power from a first drive source, and the rotating part rotates using power from a second drive source. In other words, the gripping mechanism and the rotating part are provided independently. As a result, even if the height of the workpiece to be gripped changes during setup change, it is sufficient to replace the claw and the rotating mechanism supported by it, and there is no need to change the gripping unit. As a result, the length from the base of the claw to the rotation axis can be easily changed.

[0008] In the present invention, the second drive source may be a motor. With this configuration, the orientation of the workpiece can be easily changed to any desired inclination.

[0009] In the present invention, the rotation mechanism may further include a power transmission mechanism that transmits power from the second drive source to the rotating unit, and the rotation axis of the second drive source may be perpendicular to the rotation axis of the rotating unit. In this case, the power transmission mechanism may be, for example, a bevel gear. This configuration can reduce the amount of protrusion of the second drive source in the gripping direction or the release direction.

[0010] In the present invention, the rotation mechanism may further include a power transmission mechanism that transmits power from the second drive source to the rotating unit, and the rotation axis of the second drive source may be offset parallel to the rotation axis of the rotating unit. With this configuration, the second drive source can be disposed on the inside in the gripping direction or the release direction, thereby reducing the amount by which the second drive source protrudes in the gripping direction or the release direction.

[0011] In this case, the power transmission mechanism may be a belt-shaped endless power transmission member, such as a timing belt. This configuration allows the second drive source to be located away from the rotating part, increasing the degree of freedom in the location of the second drive source. [Effects of the Invention]

[0012] According to the gripping device of the present invention, even if the height of the workpiece to be gripped changes during setup change, the length from the base of the claw portion to the rotation axis can be easily changed. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view showing a picking system including a gripping device according to a first embodiment of the present invention. [Figure 2A] FIG. [Figure 2B] 2B is a side view of the gripping device of FIG. 2A as viewed from a direction IIB. [Figure 3] FIG. 2 is a vertical cross-sectional view showing the gripping device. [Figure 4A] FIG. 10 is a front view showing a first modified example of the gripping device. [Figure 4B] 4B is a side view of the gripping device as seen from the direction IVB of FIG. 4A. [Figure 5] FIG. 10 is a front view showing a second modified example of the gripping device. [Figure 6] FIG. 10 is a front view showing a third modified example of the gripping device. [Figure 7]FIG. 10 is a front view showing a fourth modified example of the gripping device. [Figure 8] FIG. 10 is a perspective view showing a gripping device according to a second embodiment of the present invention. [Figure 9] FIG. 1 is a perspective view showing a picking system equipped with a conventional gripping device. [Figure 10] FIG. 10 is a perspective view showing a reversing process of reversing the workpiece upside down in the picking system. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a perspective view showing a picking system SY equipped with a gripping device according to a first embodiment of the present invention;

[0015] [First embodiment] [System Wide] As shown in FIG. 1, the picking system SY uses a robot 4 and a hand 6, which is a type of gripping device, to pick up the workpieces W transported by a first conveyor 2 and supply them to a second conveyor 3 for the next process. In detail, the picking system SY includes a first conveyor 2 that transports the workpieces W, a robot 4 that transports the workpieces W from the first conveyor 2 to the second conveyor 3, and a hand 6 attached to the tip of an arm 10 of the robot 4. The hand 6 of the present invention aligns the orientation of the workpieces W when placing them on the second conveyor 3.

[0016] In this embodiment, the workpiece W is a rectangular plate-shaped member. However, the workpiece W is not limited to this and may be, for example, a mechanical part, an electronic part, a plastic part, a drug, a medical product, a food product, a miscellaneous item, etc. In the following description, "F" on the workpiece W represents the front side, and "B" represents the back side.

[0017] The first conveyor 2, second conveyor 3, robot 4, and hand 6 are synchronously controlled by a control device 12. Specifically, the position and posture of the workpiece W on the first conveyor 2 is detected by a workpiece detection means (not shown), the arm 10 of the robot 4 moves to the detected position, and the hand 6 grips the workpiece W at an angle corresponding to the detected posture. Furthermore, after aligning the orientation of the workpiece W, the arm 10 of the robot 4 moves to the second conveyor 3, and the hand 6 releases the workpiece W. This operation is then repeated.

[0018] [robot] The robot 4 of this embodiment is an articulated robot having multiple arms 10 that rotate around multiple rotation axes. The robot 4 moves back and forth between a first conveyor 2 and a second conveyor 3. The robot 4 of this embodiment has a base 20 fixed to the floor surface and three arms, first to third, 10A, 10B, and 10C.

[0019] The base 20 is a cylindrical member with an axis AX1 extending in the vertical direction. The base 20 is connected to the floor surface so as to be rotatable about a first axis of rotation AX1. In this embodiment, the first axis of rotation AX1 coincides with the axis AX1 of the base 20.

[0020] The first arm 10A is a rod-shaped member extending linearly, with a base end 10Aa connected to the upper part of the base unit 20 so as to be rotatable about a second horizontal axis of rotation AX2. The second arm 10B is a rod-shaped member extending linearly, with a base end 10Ba connected to a tip end 10Ab of the first arm 10A so as to be rotatable about a third horizontal axis of rotation AX3. The second arm 10B is rotatable about a fourth horizontal axis of rotation AX4 relative to the tip end 10Ab of the first arm 10A.

[0021] The third arm 10C is a rod-like member extending linearly, and is connected to the tip 10Bb of the second arm 10B so as to be rotatable about a fifth rotation axis AX5 in the horizontal direction. The third arm 10C is rotatable about a sixth rotation axis AX6 in the vertical direction relative to the tip 10Bb of the second arm 10B. The hand 6 is attached to the lower end 10Ca of the third arm 10C.

[0022] The base 20 and the arms 10A, 10B, and 10C are driven by actuators (not shown). The actuators are, for example, electric motors, but are not limited to this. In this embodiment, the robot 4 is fixed to the floor, but it does not have to be fixed. Furthermore, the robot 4 is not limited to the structure of this embodiment, and any working robot can be applied.

[0023] [hand] The configuration of the hand 6 will be described using Figures 2A and 2B. As described above, the hand 6 is a type of gripping device that grips the workpiece W. The hand 6 picks up the workpiece W on the first conveyor 2 (Figure 1) and places the workpiece W on the second conveyor 3 (Figure 1). As shown in Figure 2A, the hand 6 has multiple claws 24 that grip or release the workpiece W, and a gripping unit 22 that moves the claws 24 in a gripping direction D1 to grip the workpiece W and in a release direction to release the workpiece W.

[0024] The gripping unit 22 has a gripping mechanism 26 to which the claws 24 are attached and which moves in a gripping direction D1 and a release direction D2, and a first drive source 28 that moves the gripping mechanism 26 in the gripping direction D1 and the release direction D2. In detail, the gripping unit 22 has a box-shaped gripping unit main body 30, and the first drive source 28 is housed inside the gripping unit main body 30.

[0025] The gripping mechanism 26 is provided to protrude from the gripping body 30, and moves relative to the gripping body 30 in the gripping direction D1 and the releasing direction D2 by the power of the first drive source 28. In this embodiment, two gripping mechanisms 26 are provided. The number of gripping mechanisms 26 is not limited to this, and may be, for example, three or more.

[0026] In this embodiment, the gripping mechanism 26 closes (moves in the closing direction) to grip the workpiece W with the claws 24. That is, in this embodiment, the gripping direction D1 for gripping the workpiece W is the closing direction, and the release direction D2 for releasing the workpiece W is the opening direction. In the following description, the gripping direction D1 is referred to as the closing direction D1, the release direction D2 is referred to as the opening direction, and the "gripping direction and release direction" are referred to as the "opening / closing direction."

[0027] The first drive source 28 is, for example, an air cylinder driven by compressed air. However, the first drive source 28 is not limited to this and may be a hydraulic motor, an electric motor, or the like. In this embodiment, one first drive source 28 drives two gripping mechanisms 26. However, each gripping mechanism 26 may be provided with its own first drive source 28.

[0028] The hand 6 further includes a rotation mechanism 32 that rotates the workpiece W. The rotation mechanism 32 rotates the workpiece W gripped by the claws 24 around a rotation axis X1 that is parallel to the opening and closing direction. The rotation mechanism 32 includes a rotation unit 34 that can rotate around the rotation axis X1 relative to the claws 24, and a second drive source 36 that drives and rotates the rotation unit 34 around the rotation axis X1.

[0029] The rotating unit 34 is attached to each of the plurality of claws 24 and moves in the opening and closing direction together with the claws 24. The second driving source 36 is attached to at least one of the claws 24 and moves in the opening and closing direction together with the claws 24. In this way, the rotating mechanism 32 moves in the opening and closing direction together with the claws 24.

[0030] The second drive source 36 may be, for example, a structure that uses a spring to rotate mechanically, a structure that uses air pressure such as an air cylinder, a structure that uses hydraulic pressure such as a hydraulic actuator, or a structure that uses electricity such as a motor. Furthermore, the first drive source 28 and the second drive source 36 may have different structures, such as the first drive source 28 being a structure that uses air pressure and the second drive source 36 being a structure that uses electricity. In this embodiment, the second drive source 36 is attached to only one of the two claws 24, but it may also be attached to both.

[0031] In this embodiment, the rotating part 34 is provided at the tip of the claw part 24. As shown in Fig. 3, the rotating part 34 has a disk-shaped rotating part main body 38 and a shaft body 40 extending in the opening direction from the end face of the rotating part main body 38. The center line of the rotating part main body 38 and the central axis of the shaft body 40 coincide with each other. Furthermore, the central axes of the pair of rotating parts 34, 34 in this embodiment coincide with each other.

[0032] The rotating part 34 in this embodiment is made of metal. However, the material of the rotating part 34 is not limited to this and may be made of resin, for example. Furthermore, a rubber sheet, rubber bumps, or the like may be provided on the gripping surface 34a of the rotating part 34 that faces the closing direction of the rotating part main body 38. This makes it possible to prevent the workpiece W from slipping when gripping the workpiece W or when rotating the gripped workpiece W.

[0033] A through hole 24a facing the opening / closing direction is provided at the tip of the claw portion 24. In this embodiment, the shaft 40 of the rotating portion 34 is inserted into this through hole 24a via a rolling bearing 42. This allows the rotating portion 34 to be rotatably supported by the claw portion 24. The axis of the through hole 24a coincides with the central axis of the rotating portion 34. In other words, the axis of the through hole 24a coincides with the rotation axis X1 of the rotating portion 34. In this embodiment, a rolling bearing 42 is used, but a bearing other than a rolling bearing may be used, and a sliding bearing may also be used.

[0034] A second driving source 36 is connected to the tip of the shaft 40 of one of the rotating parts 34. In this embodiment, the rotation axis RA of the second driving source 36 and the rotation axis X1 of the rotating part 34 are aligned. A retaining member 45 is attached to the tip of the shaft 40 of the other rotating part 34 to which the second driving source 36 is not connected. The retaining member 45 is, for example, a nut.

[0035] When the second drive source 36 is driven while the hand 6 is gripping the workpiece W, one of the rotating parts 34 rotates, and this rotation is transmitted to the other rotating part 34 via the workpiece W, causing the other rotating part 34 to also rotate. In other words, the workpiece W rotates around the rotation axis X1.

[0036] Generally, a gripping device 6 having two claws 24 needs to change the size of the gripping portion 22 itself, the opening / closing stroke, the length of the claws 24, etc. depending on the size of the workpiece W to be gripped. Fig. 9 shows a conventional picking system SY1. The gripping device 100 of this picking system SY1 has a structure in which the rotation mechanism 32 is omitted from the gripping device (hand) 6 of this embodiment.

[0037] In the conventional gripping device 100, in order to change the posture of the gripped workpiece W, it is necessary to operate each of the arms 10A, 10B, and 10C of the robot 4. In particular, when turning the workpiece W upside down, it is necessary to prepare a temporary table 102, place the workpiece W on the temporary table 102, and then change the gripping process. Figure 9 shows the process of turning the workpiece W upside down.

[0038] In the first step of FIG. 10(a), the workpiece W is conveyed in a random orientation on the first conveyor 2. The orientation and front and back of the workpiece W are determined using a camera or the like, and the workpiece W is grasped by a gripping device 100 installed on the robot 4 (FIG. 9). Next, in the second step of FIG. 10(b), the grasped workpiece W is temporarily placed on a temporary table 102. Next, in the third step of FIG. 10(c), the orientation of the gripping device 100 is changed, and the gripping device 100 re-grabs the workpiece W from the opposite direction. Finally, in the fourth step of FIG. 10(d), the re-gripped workpiece W is placed on the second conveyor 3 with its orientation aligned.

[0039] Here, if the workpiece W on the first conveyor 2 is approached horizontally instead of from above, it may not be necessary to re-grasp the workpiece W as in the second and third processes. However, in this case, a large space is required between the robot 4 and the first conveyor 2. Also, depending on the orientation of the workpiece W, it may not be possible to grasp it if approached from the horizontal direction.

[0040] [Action and effect] 2A, the configuration of this embodiment allows the rotation unit 34 and second drive source 36 for rotating the workpiece W to be separated from the first drive source 28 of the gripping mechanism 26, making it possible to easily replace them during setup changes. As a result, even if the height of the workpiece W to be gripped is different, this can be easily accommodated by replacing the rotation mechanism 32 along with the claw unit 24.

[0041] Specifically, after gripping the workpiece W shown in Fig. 1, the workpiece W can be turned over by rotating it with the rotating unit 34 without having to be gripped again. This makes it possible to omit the second step (b) and the third step (c) shown in Fig. 10, thereby shortening the transport time. In addition, the temporary placement table 102 for changing the orientation of the workpiece W is no longer necessary, thereby realizing space savings.

[0042] Furthermore, in the case of the conventional structure shown in FIG. 9, when re-gripping the workpiece W to turn it over, each arm 10A, 10B, 10C of the articulated robot 4 must move significantly. This increases the time required for the robot 4 to operate, and interference with surrounding objects must be considered. According to this embodiment, the workpiece W can be turned over without re-gripping, thereby solving these problems. In addition, because the workpiece W is rotated by the rotating unit 34 installed at the tip of the jaws 24 shown in FIG. 2A, the moment of inertia is smaller than when the entire jaws 24 including the gripping mechanism 26 are rotated. This allows the workpiece W to be rotated at a higher speed.

[0043] 4A and 4B show a gripping device (hand) 6A according to a first modification of this embodiment. In the first modification, the second drive source 36A that rotates the rotating unit 34 is configured as an electric motor. In this example, the electric motor 36A is directly connected to the rotating unit 34. Specifically, the rotation axis RA of the electric motor 36A coincides with the rotation axis X1 of the rotating unit 34. In the example shown, the electric motor 36A is installed on one of the two claws 24, 24, and the other rotating unit 34 is configured to follow it, but the electric motor 36A may be installed on both of the two claws 24, 24.

[0044] By configuring the second drive source 36A as an electric motor, the posture of the workpiece W can be easily changed to any inclination. Not only can the workpiece W be turned over, but the inclination of the workpiece W can also be freely changed, so it can be used in cases where it is better for the angle of the claw portion 24 to be inclined at a predetermined angle relative to the workpiece W, such as when the workpiece W is transported at an angle rather than flat, or when there is a notch for gripping. Furthermore, it is easy to deal with cases where the workpiece W must be placed at a predetermined angle after being gripped.

[0045] FIG. 5 shows a gripping device (hand) 6B according to a second modification of this embodiment. In the second modification, the rotation mechanism 32 has a power transmission mechanism 50 that transmits the power of the second drive source 36A to the rotation unit 34, and the rotation axis RA of the second drive source 36A is perpendicular to the rotation axis X1 of the rotation unit 34. In the example of FIG. 5, a bevel gear 50A is used as the power transmission mechanism 50. The bevel gear 50A may be a "straight gear" or a "helical gear." Furthermore, the power transmission mechanism 50 may be a gear other than a bevel gear.

[0046] 5, an electric motor is used as the second drive source 36A. However, the second drive source 36A is not limited to an electric motor. The second drive source 36A is attached to a surface of the claw portion 24 facing outward in the opening and closing direction via a motor holder 52.

[0047] A bevel gear 50A is provided between the second drive source 36A and the rotating unit 34. The bevel gear 50A has a primary gear 50Aa and a secondary gear 50Ab, and the two gears 50Aa, 50Ab mesh with each other. The primary gear 50Aa is arranged coaxially with the rotation axis RA of the second drive source 36A and is connected to the second drive source 36A. The secondary gear 50Ab is arranged coaxially with the rotation axis X1 of the rotating unit 34 and is connected to the rotating unit 34. As a result, the power of the second drive source 36A is transmitted to the rotating unit 34 via the bevel gear 50A.

[0048] In the second modified example, by using the bevel gear 50A as the power transmission mechanism 50, it is not necessary to install the electric motor 36A so that the rotation axis RA of the electric motor 36A and the rotation axis X1 of the rotating part 34 are parallel to each other. This makes it possible to prevent the electric motor 36A from protruding from the claw part 24 in the opening / closing direction.

[0049] Fig. 6 shows a gripping device (hand) 6C according to a third modification of this embodiment. In the third modification, similar to the second modification, the rotation mechanism 32 has a power transmission mechanism 50 that transmits power from a second drive source 36A to the rotating unit 34, and the rotation axis RA of the second drive source 36A is offset parallel to the rotation axis X1 of the rotating unit 34. In the example of Fig. 6, a belt-shaped endless power transmission member 50B, specifically a timing belt, is used as the power transmission mechanism 50. The endless power transmission member 50B may also be a drive chain.

[0050] 6, an electric motor is used as the second drive source 36A. However, the second drive source 36A is not limited to an electric motor. The second drive source 36A is attached to a surface of the claw 24 facing inward in the opening and closing direction via a motor holder 52. In other words, the second drive source 36A is disposed inside the claw 24 and does not protrude outward from the claw 24 in the opening and closing direction.

[0051] A timing belt 50B is provided between the second drive source 36A and the rotating unit 34. A primary pulley 54a and a secondary pulley 54b are arranged on the surface of the claw 24 facing inward in the opening and closing direction. The primary pulley 54a is arranged coaxially with the rotation axis RA of the second drive source 36A and is connected to the second drive source 36A. The secondary pulley 54b is arranged coaxially with the rotation axis X1 of the rotating unit 34 and is connected to the rotating unit 34. The timing belt 50B is stretched between the primary pulley 54a and the secondary pulley 54b. As a result, the power of the second drive source 36A is transmitted to the rotating unit 34 via the timing belt 50B.

[0052] In the third modified example, the degree of freedom in arranging the second driving source 36A is increased by using a timing belt 50B as the power transmission mechanism 50. This allows the second driving source 36A to be arranged so as not to protrude outward from the claw portion 24 in the opening and closing direction, as shown in FIG.

[0053] 7 shows a gripping device (hand) 6D according to a fourth modification of this embodiment. In this fourth modification, each gripping mechanism 26A is made up of a parallel link mechanism. That is, the gripping body 30 including the first drive source 28 and the claws 24 are connected via the parallel link mechanism 26A, and the claws 24 open and close by the power of the first drive source 28.

[0054] In the example of Fig. 7, an electric motor is used as the second driving source 36A. However, the second driving source 36A is not limited to an electric motor. Furthermore, the power of the second driving source 36A is transmitted to the rotating unit 34 via a bevel gear 50A. In other words, the rotation axis RA of the second driving source 36A is perpendicular to the rotation axis X1 of the rotating unit 34. However, the power of the second driving source 36A may be transmitted to the rotating unit 34 by a power transmission mechanism other than a bevel gear.

[0055] The second drive source 36A is attached via a motor holder 52 to a surface facing outward in the opening and closing direction of the claw portion 24. A bevel gear 50A is provided between the second drive source 36A and the rotating portion 34. The arrangement of the bevel gear 50A is the same as in the second modified example shown in Fig. 5, so a detailed description will be omitted.

[0056] According to the fourth modification, the parallel link mechanism 26A is used as the gripping mechanism, so that the tip of the claw 24 moves not only in the opening and closing direction but also in a direction perpendicular to the opening and closing direction. Therefore, as in the above embodiment, by providing the rotating unit 34 and the second driving source 36A with a structure separate from the gripping unit 22, a simple mechanism can be realized.

[0057] [Second embodiment] Fig. 8 shows a gripping device (hand) 6E according to a second embodiment of the present invention. The hand 6E of the second embodiment has three claws 24, and a rotating part 34 is provided at the tip of each claw 24. In Fig. 8, the three claws 24 are arranged at 120° intervals in the circumferential direction, i.e., at equal intervals, but they do not have to be arranged at equal intervals.

[0058] In Fig. 8, an electric motor is used as the second drive source 36A. However, the second drive source 36A is not limited to an electric motor. In the example of Fig. 8, the second drive source 36A is installed in one of the three claws 24, but not in the other two claws 24. However, the second drive source 36A may be installed in all of the claws 24, or may be installed in two of the three claws 24.

[0059] Furthermore, the power of the second driving source 36A is transmitted to the rotating unit 34 via a bevel gear 50A. In other words, the rotation axis RA of the second driving source 36A is perpendicular to the rotation axis X1 of the rotating unit 34. However, the power of the second driving source 36A may be transmitted to the rotating unit 34 by a power transmission mechanism other than a bevel gear. In the second embodiment, the rotating unit main body 38A of the rotating unit 34 is not disk-shaped as in the first embodiment, but is a smooth sphere that sandwiches the workpiece W on three sides.

[0060] The second drive source 36A is attached via a motor holder 52 to a surface facing outward in the opening and closing direction of the claw portion 24. A bevel gear 50A is provided between the second drive source 36A and the rotating portion 34. The arrangement of the bevel gear 50A is the same as in the second modified example shown in FIG. 5, so a detailed description will be omitted. The other configurations are the same as those of the first embodiment.

[0061] In the second embodiment, as in the second embodiment, even if the height of the workpiece W to be gripped during setup change is different, the length from the base of the claw portion 24 to the rotation axis X1 can be easily changed.

[0062] 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. [Explanation of symbols]

[0063] 6, 6A, 6B, 6C, 6D, 6E Hand (grasping device) 22 Gripping part 24 Claw 26,26A gripping mechanism 28 First drive source 32 Rotation mechanism 34 Rotating part 36 Second driving source 36A motor (second drive source) 50, 50A, 50B Power transmission mechanism 50A bevel gear 50B Timing belt (endless power transmission member) double work

Claims

1. A plurality of jaws for gripping or releasing a workpiece; a gripping unit that moves the claws in a gripping direction to grip the workpiece and in a release direction to release the workpiece; a rotation mechanism that rotates the workpiece gripped by the claw portion around a rotation axis that is parallel to a gripping direction and a release direction; Equipped with the gripping unit includes a gripping mechanism to which the claw portion is attached and which moves in a gripping direction and a release direction, and a first drive source which moves the gripping mechanism in the gripping direction and the release direction; The rotation mechanism includes: a rotating part attached to each of the plurality of claw parts, moving together with the claw part in the gripping direction and the releasing direction, and rotatable about the rotation axis relative to the claw part; a second drive source attached to at least one of the claws and moving together with the claws in the gripping direction and the releasing direction to rotate the rotating portion around the rotation axis; A gripping device having:

2. 2. The gripping device according to claim 1, wherein the second drive source is a motor.

3. 3. The gripping device according to claim 1, wherein the rotation mechanism further includes a power transmission mechanism that transmits power from the second drive source to the rotation unit, A gripping device in which the rotation axis of the second drive source is perpendicular to the rotation axis of the rotating part.

4. 4. The gripping device according to claim 3, wherein the power transmission mechanism is a bevel gear.

5. 3. The gripping device according to claim 1, wherein the rotation mechanism further includes a power transmission mechanism that transmits power from the second drive source to the rotation unit, A gripping device in which the rotation axis of the second drive source is offset parallel to the rotation axis of the rotating unit.

6. 6. The gripping device according to claim 5, wherein the power transmission mechanism is a belt-shaped endless power transmission member.

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