Hand device and workpiece processing system

Abstract

The hand device is mounted on the robot arm and holds a workpiece that twists about a twisting axis. The hand device includes: a base (12) that is mounted on the robot arm; and a holding part (11) that is rotatably supported by the base (12) about a specified rotation axis (A) and holds the workpiece. The holding part (11) holds the workpiece on the specified rotation axis (A) such that the twisting axis substantially follows the specified rotation axis (A), and rotates in the twisting direction of the workpiece along with an external force acting in the tangential direction of the specified rotation axis (A) of the workpiece.

Description

Technical Field

[0001] The present invention relates to a hand device and a workpiece processing system. Background Art

[0002] Conventionally, a robotic hand is known that includes a first hand portion and a second hand portion, the first hand portion and the second hand portion being connected to each other by an elastic member and being displaceable relative to each other by elastic deformation of the elastic member (for example, see Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-150915 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] For example, when taking out and inserting a twisted workpiece such as a turbine blade for an aircraft jet engine from a narrow workpiece accommodation portion, in order to prevent damage to the workpiece due to contact between the workpiece and an object around the workpiece accommodation portion, it is necessary to take out and insert the workpiece from the workpiece accommodation portion while rotating the workpiece according to the twisted shape of the workpiece. In the case of processing various workpieces with different twisted shapes, the rotation operation of the workpiece when taking out and inserting the workpiece from the workpiece accommodation portion varies depending on the workpiece.

[0008] Solutions to the Problems

[0009] One aspect of the present disclosure is a hand device that is mounted on a robotic arm and holds a workpiece that is twisted about a twisting axis. The hand device includes: a base that is mounted on the robotic arm; and a holding portion that is rotatably supported by the base about a predetermined rotation axis and holds the workpiece. The holding portion holds the workpiece on the predetermined rotation axis such that the twisting axis is substantially along the predetermined rotation axis, and rotates in the twisting direction of the workpiece along with an external force acting in the tangential direction of the predetermined rotation axis on the workpiece. Brief Description of the Drawings

[0010] Figure 1 is an overall configuration diagram of a workpiece processing system according to an embodiment.

[0011] Figure 2 is a view showing a blade as an example of a workpiece.

[0012] Figure 3 is a view showing a workpiece accommodated in a container.

[0013] Figure 4 is a partial side view of a hand device according to an embodiment.

[0014] Figure 5 It is a sectional view taken along line I-I of the hand device.

[0015] Figure 6 It is a diagram for explaining the operation of the hand device, and is a diagram showing the origin return state in which the jig is positioned at the origin position by the origin return mechanism.

[0016] Figure 7A It is a diagram for explaining the operation of the hand device, and is a diagram showing an example of the free rotation state in which the jig can rotate freely within a specified angular range restricted by the rotation restriction mechanism.

[0017] Figure 7B It is a diagram showing another example of the free rotation state.

[0018] Figure 7C It is a diagram showing yet another example of the free rotation state.

[0019] Figure 8A It is a diagram for explaining the operation of the hand device, and is a diagram showing an example of the rotation locking state in which the rotation of the jig is locked by the rotation locking mechanism.

[0020] Figure 8B It is a diagram showing another example of the rotation locking state.

[0021] Figure 8C It is a diagram showing yet another example of the rotation locking state.

[0022] Figure 9 It is a diagram for explaining the processing of a workpiece by a workpiece processing system.

[0023] Figure 10 It is a diagram for explaining the processing of a workpiece by a workpiece processing system.

[0024] Figure 11 It is a diagram for explaining the processing of a workpiece by a workpiece processing system.

[0025] Figure 12 It is a diagram for explaining the processing of a workpiece by a workpiece processing system. Detailed Embodiment

[0026] Hereinafter, a hand device and a workpiece processing system according to an embodiment will be described with reference to the drawings.

[0027] As Figure 1As shown, the workpiece processing system 100 is a robot system including two industrial robots 2 and 3, and a control device 4 that controls the robots 2 and 3. A container 20 for accommodating a plurality of workpieces W is disposed near the robots 2 and 3. The first robot 2 takes out and places the plurality of workpieces W one by one from the container 20, and the second robot 3 guides the workpieces W taken out and placed from the container 20.

[0028] The robots 2 and 3 are, for example, 6-axis vertical multi-joint robots, and each has a robot arm 2a, 3a, and mounting surfaces 2b, 3b provided at the front ends of the robot arms 2a, 3a. The robots 2 and 3 may also be vertical multi-joint robots with an axis number other than 6 or other types of robots.

[0029] As Figure 2 shown, the workpiece W has a twisted portion Wa with a twisted and bent shape. Figure 2 The workpiece W shown is an example of a blade of an aircraft engine, and has a wing portion Wa on the front end side and a base portion Wb on the base end side. The wing portion Wa is a twisted portion that is twisted about a twisting axis B extending from the base end side to the front end side of the blade W. The base portion Wb is a portion connected to a disk-shaped disk of the engine, and is fitted into a groove formed in the outer peripheral portion of the disk. A plurality of blades W having different dimensions and twisting shapes are used for one engine.

[0030] For example, when the engine is overhauled, the plurality of removed blades W are accommodated in the container 20. A plurality of wires 21 are provided in parallel at the opening above the container 20, and the opening of the container 20 is divided into a plurality of entrances and exits 22 by the plurality of wires 21. As Figure 3 shown, each blade W is accommodated in a workpiece accommodation portion 23 below the entrance and exit 22, and the blade W is suspended in the workpiece accommodation portion 23 by hooking the base portion Wb on a pair of wires 21. Since the blade W has a twisted shape, when the blade W is translated vertically upward, the blade W will interfere with the wires 21.

[0031] The workpiece processing system 100 includes: a hand device 1 mounted on the mounting surface 2b of the robot arm 2a, a guiding device 5 mounted on the mounting surface 3b of the robot arm 3a, and a vision sensor 6. The hand device 1, the guiding device 5, and the vision sensor 6 are three-dimensionally moved by the movements of the robot arms 2a, 3a respectively. The hand device 1, the guiding device 5, and the vision sensor 6 can rotate about an axis orthogonal to the mounting surfaces 2b, 3b by the rotation of the mounting surfaces 2b, 3b. The hand device 1, the vision sensor 6, and the guiding device 5 are controlled by the control device 4.

[0032] As Figure 1 , Figure 4 and Figure 5As shown in the figure, the hand device 1 includes: a jig (holding part) 11 for holding the workpiece W; a base 12 mounted on the mounting surface 2b and supporting the jig 11 so as to be rotatable about a specified rotation axis A; and a weight sensor 13 for measuring the weight of the workpiece W held by the jig 11.

[0033] The jig 11 has: a jig body 11a; a cylindrical shaft 11b fixed to the jig body 11a and protruding from the base end surface of the jig body 11a; and a plurality of finger parts 11c arranged on the front end side of the jig body 11a and capable of opening and closing with each other. The central axis of the shaft 11b is the specified rotation axis A.

[0034] The hand device 1 is a two-handed device having two jigs 11 that share one shaft 11b and face in opposite directions. Only one of the two jigs 11 is shown in the figure. The hand device 1 may also be a single-handed device having only one jig 11. Figure 4 Only one of the two jigs 11 is shown in the figure. The hand device 1 may also be a single-handed device having only one jig 11.

[0035] The plurality of finger parts 11c are arranged at intervals in the circumferential direction around the rotation axis A. The jig 11 shown in the reference drawing has two finger parts 11c, but the jig 11 may also have three or more finger parts 11c. By bringing the plurality of finger parts 11c closer to the rotation axis A, the plurality of finger parts 11c are closed, and by moving the plurality of finger parts 11c away from the rotation axis A, the plurality of finger parts 11c are opened. The workpiece W is held on the rotation axis A by the closed plurality of finger parts 11c and rotates around the rotation axis A on the rotation axis A by the rotation of the jig 11.

[0036] The base 12 has: a fixing part 12a fixed to the mounting surface 2b of the robot arm 2a; and at least one supporting part 12b for supporting the shaft 11b. The supporting part 12b has a hole through which the shaft 11b passes, and supports the jig 11 so as to be rotatable about the rotation axis A by a bearing (not shown) disposed between the outer peripheral surface 11f of the shaft 11b and the inner peripheral surface of the hole. Therefore, the plurality of finger parts 11c and the workpiece W held by the plurality of finger parts 11c can freely rotate relative to the base 12 about the rotation axis A, but cannot be displaced relative to the base 12 in the direction along the rotation axis A and in the direction orthogonal to the rotation axis A.

[0037] In one example, the base 12 is a U-shaped bracket having two flat plate-like supporting parts 12b parallel to each other and a flat plate-like fixing part 12a connecting one end of the two supporting parts 12b to each other, and supports the two jigs 11 in such a manner that the rotation axis A is parallel to the mounting surface 2b.

[0038] Further, the hand device 1 includes: a movable member 14 disposed radially outside the shaft 11b; a pair of stoppers (home return mechanism, rotation restriction mechanism) 15a, 15b provided on the movable member 14, and a braking portion (rotation locking mechanism) 16; and a cylinder (drive portion) 17 that moves the movable member 14 relative to the jig 11 and the base 12 in a predetermined moving direction P orthogonal to the rotation axis A. In the attached drawings for reference, the moving direction P is a direction parallel to the mounting surface 2b of the robot arm 2a.

[0039] As Figure 5 shown, the movable member 14 has a first portion 14a and a second portion 14b that face each other in the moving direction P with the shaft 11b interposed therebetween. A pair of stoppers 15a, 15b are provided on the first portion 14a, and a braking portion 16 is provided on the second portion 14b. The distance between the first portion 14a and the second portion 14b is greater than the diameter of the shaft 11b, and the movable member 14 can be arranged in a state where the pair of stoppers 15a, 15b and the braking portion 16 are all separated from the shaft 11b.

[0040] The pair of stoppers 15a, 15b are arranged at intervals in the circumferential direction around the rotation axis A and project from the inner side surface of the first portion 14a toward the shaft 11b in the moving direction P. As will be described later, the pair of stoppers 15a, 15b function as a rotation restriction mechanism that restricts the rotation of the jig 11 within a predetermined angular range and a home return mechanism that returns the rotation position of the jig 11 around the rotation axis A to a predetermined home position, depending on the position of the movable member 14.

[0041] On the outer peripheral surface 11f of the shaft 11b, a pair of protrusions 11d, 11e are provided that function as a home return mechanism and a rotation restriction mechanism together with the pair of stoppers 15a, 15b. The pair of protrusions 11d, 11e are provided on the same side with respect to the rotation axis A and project from the outer peripheral surface 11f in opposite directions in the tangential direction of the circumference around the rotation axis A. As Figure 5 shown, the shaft 11b is arranged in an attitude where the pair of protrusions 11d, 11e are disposed on the side of the first portion 14a, and the pair of protrusions 11d, 11e are opposed to the pair of stoppers 15a, 15b in the moving direction P. The front ends of the pair of protrusions 11d, 11e are arranged at positions outside the front ends of the pair of stoppers 15a, 15b in the circumferential direction.

[0042] It is also possible to configure as follows: the position of each stopper 15a, 15b relative to the movable member 14 can be adjusted in the moving direction P. For example, the pair of stoppers 15a, 15b can be a pair of screws inserted into a pair of threaded holes formed in the first portion 14a toward the shaft 11b along the moving direction P. By rotating each screw 15a, 15b, the position of the front end of each screw 15a, 15b in the moving direction P can be finely adjusted.

[0043] The brake portion 16 is provided on the inner side surface of the second portion 14b and is opposed to the outer peripheral surface 11f of the shaft 11b in the moving direction P. The brake portion 16 can move between the locking position and the unlocking position by the movement of the movable member 14. In the locking position, the brake portion 16 is pressed against the outer peripheral surface 11f, and the rotation of the clamp 11 relative to the base 12 is locked by the friction between the brake portion 16 and the outer peripheral surface 11f. In the unlocking position, the brake portion 16 is separated from the outer peripheral surface 11f, and the locking of the rotation of the clamp 11 is released.

[0044] In order to increase the contact area between the braking portion 16 and the outer peripheral surface 11f and increase the friction force, the braking portion 16 may have a concave surface having a shape complementary to the cylindrical outer peripheral surface 11f and in close contact with the outer peripheral surface 11f. In addition, in order to increase the friction force, the braking portion 16 may have a high friction component at the portion in contact with the outer peripheral surface 11f.

[0045] The cylinder 17 has a piston rod 17a that is telescopic in the moving direction P, and can position the piston rod 17a at the rearward end, the forward end, and the middle position between the rearward end and the forward end. The movable member 14 is fixed to the front end of the piston rod 17a. Figure 6 , Figures 7A to 7C as well as Figures 8A to 8C As shown, the cylinder 17 moves the movable member 14 along the moving direction P between the origin reset position, the free rotation position and the locked position by extending and retracting the piston rod 17a, thereby being able to Figure 6 , Figures 7A to 7C ,as well as Figures 8A to 8C Switches between the three states shown.

[0046] Figure 6 The piston rod 17a is arranged at the forward end, and the movable part 14 is arranged at the origin reset position. In the origin reset state, the brake part 16 is arranged at the lock release position, and the pair of limit members 15a and 15b function as an origin reset mechanism. That is, the front ends of the pair of limit members 15a and 15b are in contact with the pair of protrusions 11d and 11e at the same time, and the rotation position of the clamp 11 around the rotation axis A is positioned at a predetermined origin position. Figure 6In the example, the specified origin position is a position where the tangential direction in which a pair of protrusions 11d and 11e protrude is parallel to the straight line connecting the front ends of a pair of stoppers 15a and 15b to each other. When the pair of stoppers 15a and 15b are screws, the specified origin position can be changed by adjusting the position of the front ends of the screws in the moving direction P.

[0047] Figures 7A to 7C The free rotation state in which the piston rod 17a is disposed at the intermediate position and the movable member 14 is disposed at the free rotation position between the origin reset position and the locked position is shown. In the free rotation state, the braking portion 16 is disposed at the unlocking position, and the pair of stoppers 15a and 15b function as a rotation restricting mechanism. That is, the front ends of the pair of stoppers 15a and 15b are disposed at positions separated from the pair of protrusions 11d and 11e at the origin position in the moving direction P, and the jig 11 is rotatable between the rotation position where one protrusion 11d abuts against one stopper 15a in the circumferential direction and the rotation position where the other protrusion 11e abuts against the other stopper 15b. When the pair of stoppers 15a and 15b are screws, the specified angular range can be changed by adjusting the position of the front ends of the screws in the moving direction P.

[0048] Figures 8A to 8C The rotation locked state in which the piston rod 17a is disposed at the retracted end and the movable member 14 is disposed at the locked position is shown. In the rotation locked state, the braking portion 16 is disposed at the rotation locked position, and the rotation of the jig 11 about the rotation axis A is locked. As Figures 8A to 8C shown, the braking portion 16 abuts against a part of the circumferential direction of the outer peripheral surface 11f of the jig 11, and the rotation of the jig 11 at an arbitrary rotation position within the specified angular range can be locked.

[0049] As Figure 1 shown, the guiding device 5 includes: a base 5a fixed to the mounting surface 3b of the robot arm 3a; a pair of guiding members 5b and 5c supported by the base 5a; and a driving portion 5d for relatively moving the pair of guiding members 5b and 5c.

[0050] The pair of guiding members 5b and 5c are cylindrical members parallel to each other. The pair of guiding members 5b and 5c are disposed on both sides of the entrance and exit 22 parallel to the longitudinal direction of the entrance and exit 22, and guide the workpiece W in such a manner that the workpiece W is taken out from and put into the workpiece accommodating portion 23 while rotating in the torsional direction (see Figures 9 to 12 .). That is, when the torsional portion Wa of the workpiece W moves up and down along the rotation axis A and contacts the guiding member 5b or 5c, an external force in the tangential direction about the rotation axis A is applied to the workpiece W and the jig 11 from the guiding members 5b and 5c, and the jig 11 rotates in the torsional direction of the workpiece W along with the external force.

[0051] In order to enable the workpiece W to smoothly move up and down while in contact with the guide members 5b and 5c, the guide members 5b and 5c may have cylindrical rollers that rotate about the long axes of the guide members 5b and 5c. Alternatively, in order to reduce the friction between the workpiece W and the guide members 5b and 5c, a low-friction material such as polytetrafluoroethylene may be used on the outer peripheral surfaces of the guide members 5b and 5c.

[0052] For example, the drive unit 5d is an electric actuator connected to the pair of guide members 5b and 5c respectively. The drive unit 5d adjusts the interval between the pair of guide members 5b and 5c by moving the pair of guide members 5b and 5c in directions approaching or separating from each other.

[0053] The vision sensor 6 is, for example, a two-dimensional camera. The vision sensor 6 acquires an image of the workpiece W in the container 20 and sends the image to the control device 4.

[0054] The control device 4 is connected to the two robots 2 and 3, the hand device 1, the guide device 5, the vision sensor 6, and the weight sensor 13. The control device 4 controls the robots 2 and 3, the hand device 1, and the guide device 5 based on the image acquired by the vision sensor 6, so that the robots 2 and 3, the hand device 1, and the guide device 5 perform a take-out operation of taking out the workpiece W from the container 20 and an insertion operation of inserting the workpiece W into the container 20. For example, the control device 4 includes a processor and a storage device that stores an operation program, and the processor executes processing according to the operation program, thereby implementing the take-out operation and the insertion operation of the workpiece W.

[0055] Next, the operation of the workpiece processing system 100 will be described.

[0056] Figures 9 to 12 The operation of measuring the weights of the plurality of workpieces W accommodated in the container 20 one by one has been described. In Figures 9 to 12 the illustration of the wire 21 and the entrance / exit 22 is omitted.

[0057] First, as Figure 9 shown, the control device 4 moves the vision sensor 6 to a position where the field of view of the vision sensor 6 includes one entrance / exit 22 by operating the robot arm 3a. Next, the control device 4 causes the vision sensor 6 to execute image acquisition. The bottom surface of the base portion Wb of the workpiece W is included in the acquired image.

[0058] Next, the control device 4 detects the presence or absence of the workpiece W and the position of the workpiece W based on the image. For example, the control device 4 detects the workpiece W by recognizing the bottom surface of the base portion Wb within the image. Next, the control device 4 recognizes the four side surfaces adjacent to the bottom surface of the base portion Wb within the image, calculates the centerlines between a pair of opposing side surfaces and the centerlines between the other pair of opposing side surfaces, and detects the intersection point of the two centerlines, i.e., the center position of the bottom surface, as the position of the workpiece W.

[0059] Next, as Figure 10 shown, the control device 4 operates the robot arms 2a and 3a based on the detected position of the workpiece W, and moves the hand device 1 and the guide device 5 near the workpiece W. At this time, the control device 4 operates the air cylinder 17 to move the movable member 14 to the origin reset position, thereby resetting the jig 11 to the origin position. And the control device 4 configures the hand device 1 in such a manner that the rotation axis A coincides with the detected position of the workpiece W, i.e., the center position of the bottom surface, and arranges the plurality of finger portions 11c on both sides in the width direction of the workpiece W.

[0060] And the control device 4 controls the hand device 1 to cause the jig 11 to hold the base portion Wb of the workpiece W. The workpiece W is held by the jig 11 in such a manner that the torsion axis B of the torsion portion Wa is along the rotation axis A. In addition, the control device 4 arranges a pair of guide members 5b and 5c on both sides of the entrance / exit 22, thereby sandwiching the base end portion of the torsion portion Wa between the pair of guide members 5b and 5c, and adjusts the interval between the pair of guide members 5b and 5c to be equal to the width of the entrance / exit 22. At this time, the base end portion of the torsion portion Wa can be pulled out to a position above the wire 21 by slightly raising the hand device 1.

[0061] Next, the control device 4 operates the air cylinder 17 to move the movable member 14 to the free rotation position, thereby making the jig 11 in a rotatable state. And as Figure 11 shown, the control device 4 moves the mounting surface 2b upward in the vertical direction by the operation of the robot arm 2a, thereby raising the hand device 1 holding the workpiece W in the vertical direction. During the upward movement of the workpiece W, the jig 11 and the workpiece W rotate smoothly integrally through the contact between the torsion portion Wa and the guide member 5b or 5c. Therefore, the workpiece W is rotated in the torsion direction while being taken out from the workpiece accommodating portion 23.

[0062] Next, the control device 4 operates the air cylinder 17 to move the movable member 14 to the locking position, thereby locking the rotation of the jig 11 holding the workpiece W. And the control device 4 causes the weight sensor 13 to measure the weight of the workpiece W and stores the measured value of the weight.

[0063] Next, the control device 4 moves the movable member 14 to the freely rotatable position by the operation of the air cylinder 17, so that the jig 11 is in a rotatable state. Further, the control device 4 moves the mounting surface 2b downward in the vertical direction by the operation of the robot arm 2a, so that the hand device 1 holding the workpiece W descends in the vertical direction. During the descent of the workpiece W, the jig 11 and the workpiece W rotate smoothly integrally by the contact between the torsion portion Wa and the guide members 5b or 5c. Therefore, the workpiece W is inserted into the workpiece accommodating portion 23 through the entrance / exit 22 while rotating in the torsion direction. At this time, the rotation directions of the workpiece W and the jig 11 are opposite to those at the time of taking out.

[0064] Here, conventionally, in order to take in and out a torsion workpiece W while rotating it from a narrow workpiece accommodating portion 23, an operation program having a plurality of teaching positions corresponding to the torsion shape of the workpiece W is used. If the workpiece W to be processed is only one type having the same torsion shape, only one type of operation program needs to be created. If the workpiece W to be processed is a plurality of types having different torsion shapes, a plurality of operation programs with different teaching positions need to be created. In this case, the teaching work requires a large amount of man-hours, and it is difficult to manage a plurality of programs.

[0065] According to the present embodiment, the workpiece W held by the jig 11 is rotatable integrally with the jig 11 about the rotation axis A along the direction of the torsion axis B, and is lifted and lowered while rotating according to the torsion shape by contact with the guide members 5b and 5c. Therefore, by a common and simple operation of the translation of the mounting surface 2b at the front end of the robot arm 2a in the vertical direction, various workpieces W having different torsion shapes can be taken in and out from the narrow workpiece accommodating portion 23. That is, since a common operation program can be used for taking in and out various workpieces W from the workpiece accommodating portion 23, the man-hours of the teaching work can be reduced, and the management of the operation program can be facilitated.

[0066] In addition, the visual sensor 6 is used to acquire the presence or absence of the workpiece W and the position information of the workpiece W. Therefore, in the case where a plurality of entrances / exits 22 are arranged at a predetermined interval, after one workpiece W whose weight has been measured is returned to the workpiece accommodating portion 23, the hand device 1 and the guide device 5 are moved by a predetermined interval, and then by repeating Figures 9 to 12 the operation, the weight measurement of another workpiece W can be performed. That is, only by one basic operation mode, the taking in and out of a plurality of workpieces W accommodated in the container 20 can be performed.

[0067] In addition, the support mechanism that supports the jig 11 to be rotatable is realized by a simple mechanical structure. Therefore, the appropriate rotation of the workpiece W corresponding to the torsion shape can be realized with high reliability and at low cost.

[0068] In the above-described embodiment, the entrance / exit 22 can be further detected using the vision sensor 6.

[0069] For example, when inserting the workpiece W into the empty workpiece accommodating portion 23, the control device 4 detects the position of the entrance / exit 22 of the empty workpiece accommodating portion 23 based on the image acquired by the vision sensor 6, and controls the robot arms 2a and 3a based on the detected position of the entrance / exit 22, thereby arranging the hand device 1 and the guiding device 5 near the entrance / exit 22 of the empty workpiece accommodating portion 23. Thereby, the insertion of the workpiece W into the empty workpiece accommodating portion 23 can be automatically performed.

[0070] In the above-described embodiment, the cylinder 17 is used as the drive unit for moving the movable member 14, but alternatively, other devices capable of positioning the movable member 14 at three positions can also be used. For example, the drive unit can also be an electric cylinder.

[0071] In the above-described embodiment, the guiding device 5 may further include a non-contact sensor that senses the workpiece W between the pair of guiding members 5b and 5c in a non-contact manner. For example, the non-contact sensor has: a light source that is provided on one of the guiding members 5b and emits laser light from the one guiding member 5b toward the other guiding member 5c; and a light detector that is provided on the other guiding member 5c and detects the laser light.

[0072] In the operation of taking out the workpiece W, during the period when at least a part of the workpiece W is accommodated in the workpiece accommodating portion 23, the workpiece W is sensed by the non-contact sensor, and when the workpiece W is completely taken out from the workpiece accommodating portion 23, the workpiece W is not sensed by the non-contact sensor. Based on this change of the workpiece W from "sensed" to "not sensed", the control device 4 senses that the workpiece W is completely taken out from the workpiece accommodating portion 23 and stops the hand device 1 from rising.

[0073] For example, various lengths of blades W are used in the engine of an aircraft. By providing the non-contact sensor, even when the lengths of the workpieces W are different, the hand device 1 can be stopped from rising at an appropriate position for each workpiece W.

[0074] In the above-described embodiment, the home position reset mechanism, the rotation restricting mechanism, and the rotation locking mechanism selectively function by the movement of the common movable member 14, but alternatively, they can also be configured to operate independently of each other. In this case, the specific structures of the home position reset mechanism, the rotation restricting mechanism, and the rotation locking mechanism are not limited to the above structures, and any structure can be adopted.

[0075] For example, it can also be configured such that a pair of stoppers 15a and 15b and the braking portion 16 are provided on different movable members and are moved by different drive units.

[0076] In addition, the limit members of the origin reset mechanism and the limit members of the rotation limit mechanism may also be provided separately. In this case, the structures of the limit members and the protrusions of the rotation limit mechanism can be changed. For example, it can be configured such that one protrusion moves circumferentially between a pair of limit members, or it can also be configured such that one limit member is disposed between a pair of protrusions protruding radially outward from the outer peripheral surface 11f.

[0077] In the above-described embodiment, the workpiece processing system 100 includes two robots 2 and 3 and the guiding device 5, but it is not necessary to include the second robot 3 and the guiding device 5.

[0078] For example, the vision sensor 6 may also be installed at the front end of the robot arm 2a of the first robot 2. In this case, the workpiece W rotates not by contacting the guiding members 5b and 5c, but by contacting an object around the entrance / exit 22 or the workpiece accommodating portion 23. For example, when there is an edge surrounding the entrance / exit 22 or a wall surrounding the workpiece accommodating portion 23, the edge or the wall can be used instead of the guiding members 5b and 5c.

[0079] In the above-described embodiment, the holding portion is the jig 11 that holds the workpiece W by a plurality of finger portions, but the holding portion may also hold the workpiece W in other ways. For example, the holding portion may be an adsorption type that adsorbs the workpiece W by vacuum pressure or magnetic force.

[0080] In the above-described embodiment, the direction in which the workpiece W is taken in and out of the workpiece accommodating portion 23 is the vertical direction, and the mounting surface 2b at the front end of the robot arm 2a is translated along the vertical direction. Alternatively, however, the take-in and out direction may be other directions. For example, the workpiece W may also be taken in and out of the workpiece accommodating portion along the horizontal direction. In this case, the workpiece W is taken in and out of the workpiece accommodating portion by translating the mounting surface 2b in the horizontal direction.

[0081] Description of reference numerals:

[0082] 1: Hand device

[0083] 2, 3: Robots

[0084] 2a, 3a: Robot arms

[0085] 2b, 3b: Mounting surfaces

[0086] 4: Control device

[0087] 5: Guiding device

[0088] 5b, 5c: Guiding members

[0089] 6: Vision sensor

[0090] 11: Fixture (Gripping Part)

[0091] 11d, 11e: Protrusions (Home Return Mechanism, Rotation Limiting Mechanism)

[0092] 12: Base

[0093] 14: Movable Part

[0094] 15a, 15b: Limit Parts (Home Return Mechanism, Rotation Limiting Mechanism)

[0095] 16: Braking Part (Rotation Locking Mechanism)

[0096] 17: Cylinder (Drive Part)

[0097] 22: Inlet / Outlet

[0098] 23: Workpiece Accommodation Part

[0099] 100: Workpiece Handling System

[0100] A: Axis of Rotation

[0101] B: Axis of Torsion

[0102] P: Direction of Movement

[0103] W: Workpiece, Vane

Claims

1. A hand device is mounted on a robotic arm and holds a workpiece that twists about a twisting axis. The hand device is characterized by comprising: a base mounted on the robotic arm; and a holding part rotatably supported on the base about a specified rotation axis and holding the workpiece, the holding part holds the workpiece on the specified rotation axis such that the twisting axis substantially aligns with the specified rotation axis, and rotates in the twisting direction of the workpiece along with an external force acting in the tangential direction of the specified rotation axis of the workpiece. The hand device further comprises: a movable part disposed radially outside the holding part in a direction orthogonal to the specified rotation axis; a driving part that moves the movable part relative to the holding part in a specified moving direction orthogonal to the specified rotation axis; and a pair of limit members and a braking part, the pair of limit members and the braking part are provided on the movable part, and the pair of limit members and the braking part are disposed at positions facing each other across the holding part in the moving direction. A pair of protrusions are provided on the outer surface of the holding part, and the pair of protrusions protrude from the outer surface in opposite directions in the tangential direction of the circumference about the specified rotation axis. By moving the movable part by the driving part, the origin reset state, the free rotation state, and the rotation lock state are switched. The origin reset state is a state in which the rotation position of the holding part about the specified rotation axis is reset to a specified origin position by the pair of limit members simultaneously contacting the pair of protrusions. The free rotation state is a state in which the rotation of the holding part is restricted within a specified angular range by the pair of limit members respectively abutting against the pair of protrusions in the circumferential direction. The rotation lock state is a state in which the rotation of the holding part is locked by the braking part pressing against the outer surface of the holding part.

2. The hand device according to claim 1, wherein the hand device comprises a rotation restricting mechanism that restricts the rotation of the holding part relative to the base within a specified angular range.

3. The hand device according to claim 1 or 2, wherein the hand device comprises a rotation locking mechanism that locks the rotation of the holding part disposed at any rotation position about the specified rotation axis.

4. The hand device according to claim 1 or 2, wherein the hand device comprises an origin reset mechanism that resets the rotation position of the holding part about the specified rotation axis to a specified origin position.

5. A workpiece processing system, characterized in that, Comprising: the hand device according to any one of claims 1 to 4; and a guiding device disposed near the entrance and exit of a workpiece accommodating part and guiding the workpiece taken out from and put into the workpiece accommodating part, the guiding device comprises: a base mounted on a robotic arm; and a pair of guiding members supported on the base and disposed on both sides of the entrance and exit.

6. The workpiece processing system according to claim 5, wherein The workpiece processing system includes a control device that controls the movement of the robotic arm on which the hand device is mounted. When taking out and placing the workpiece held by the holding part from the workpiece accommodating part, the control device moves the front end of the robotic arm on which the hand device is mounted in translation along the taking-out and placing direction of the workpiece.

7. The workpiece processing system according to claim 6, wherein: The workpiece processing system includes a vision sensor for detecting the entrance / exit of the workpiece accommodating part and the workpiece accommodated in the workpiece accommodating part. The control device controls the robotic arm based on the positions of the entrance / exit and the workpiece detected by the vision sensor.

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