JP6858142B2 - Robot hand - Google Patents

Description

The present invention relates to a robot hand.

As a conventional robot hand, the robot hand of Patent Document 1 is known. This robot hand has a pair of gripping claws, and the work is gripped and conveyed by the gripping claws.

Japanese Unexamined Patent Publication No. 2017-080819

For example, the work may be transported to a processing machine and attached to a fixture of the processing machine. In this case, in the robot hand of Patent Document 1, it is conceivable that the work is conveyed to the processing machine by the robot hand, and then the worker tightens the screw of the fitting while holding the work so that it can be attached to the fitting. Be done.

However, in order to improve work efficiency, we would like to attach the work to the processing machine by a robot instead of a worker. In this case, it is necessary to attach the work by another robot equipped with a nut runner while holding the work by the robot equipped with the hand. However, this is not preferable because two robots are required.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a robot hand for transporting, holding, and attaching a work by one robot.

The robot hand according to an aspect of the present invention is a robot hand that can be attached to and detached from a robot arm, and has a base that is detachably attached to the arm and a grip portion that is provided on the base and grips a work. A state in which a support portion that can be expanded and contracted with respect to the base and a drive portion that expands and contracts the support portion are provided, the work is gripped by the grip portion, and the arm is separated from the base. , It is supported by the extended support portion and stands on the floor surface.

According to this configuration, the robot hand is removed from the arm while the work is gripped by the gripping portion, and the robot hand is supported by the supporting portion to stand on its own. While holding the work in this way, another robot hand can be attached to the arm, and the robot hand can be used to perform another work such as attaching the work to the processing machine. Therefore, the work can be transported, held, and attached by one robot.

In this robot hand, the tip of the support portion moves forward and backward between a position farther from the base than the tip of the grip portion and a position closer to the base than the tip of the grip portion. It may expand and contract to move. According to this configuration, the support portion can be reduced from being hindered from the gripping work of the work by the gripping portion due to the contraction. On the other hand, by extending the support portion, the first hand can be supported while the grip portion grips the work.

In this robot hand, the support portion may have a plurality of telescopic portions arranged at intervals in a direction orthogonal to the telescopic direction. According to this configuration, the area surrounded by the stretchable portion of the support portion is increased, and the stability of the support portion supporting the first hand can be improved.

In this robot hand, the plurality of the telescopic portions may be provided in pairs so as to sandwich the grip portion. According to this configuration, the support portion can support the first hand without hindering the gripping portion of the work.

In this robot hand, the grip portion has a pair of claw portions that sandwich the work, and the pair of claw portions may be bent in a direction in which the base end is connected to the base and the tips thereof face each other. According to this configuration, the grip portion can grip even a heavy work without damage by placing the work on the tip portion of the bent claw portion.

The present invention has the configuration described above, and has an effect that a robot hand for transporting, holding, and attaching a work can be provided by one robot.

The above objectives, other objectives, features, and advantages of the present invention will be apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings.

It is a figure which shows typically the robot provided with the robot hand which concerns on embodiment of this invention. It is a functional block diagram which shows the structure of the robot of FIG. FIG. 3A is a view of the first hand with the support portion contracted as viewed from the first direction, and FIG. 3B is a view of the first hand with the support portion extended as viewed from the first direction. is there. FIG. 4A is a view of the first hand with the support portion contracted as viewed from the second direction, and FIG. 4B is a view of the first hand with the support portion extended as viewed from the second direction. is there. It is a perspective view which shows the 1st hand which became independent by the support part.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. In the following, the same or corresponding elements will be designated by the same reference numerals throughout the drawings, and duplicate description thereof will be omitted.

(Embodiment)
<Robot configuration>
As shown in FIG. 1, the robot 100 including the robot hand (hand 10) according to the first embodiment is a mechanical device that conveys a work 40 and attaches it to a processing machine or the like, and is a vertical articulated robot. The work performed by the robot 100 is not limited to the transfer of the work 40 and the attachment to the processing machine, and other work may be performed. Further, the robot 100 is not limited to the vertical articulated robot, and may be another robot such as a horizontal articulated robot.

As shown in FIGS. 1 and 2, the robot 100 has a mounting table 31, an arm 30, hands 10, 20 and a control unit 50. The mounting table 31 is fixed to the floor, and a base shaft (not shown) is provided on the upper surface thereof. The arm 30 is attached to the mounting base 31 so as to be rotatable around this base shaft. The details of the hands 10 and 20 will be described later.

The arm 30 is a moving portion capable of moving the hands 10 and 20, and has a plurality of links 32 and one or more joints 33. The joint 33 is a rotary joint or a linear motion joint. The links 32 are connected to each other via joints 33. Further, the joint 33 is provided with an actuator such as a servomotor (not shown) that relatively rotates or linearly moves two links 32 connected to each other. Thereby, the arm 30 can move the hands 10 and 20 in the vertical direction, the horizontal direction, and the front-rear direction which are orthogonal to each other, for example.

Further, the joint 33 is provided with, for example, a position sensor (not shown) such as an encoder that detects the drive position of the actuator, and a current sensor (not shown) that detects the current that controls the drive of the actuator. ing. The detection signals of these sensors are output to the control unit 50.

The control unit 50 is a control device such as a robot controller including a calculation unit 51 such as a CPU, a storage unit 52 such as a ROM and RAM, and a servo control unit 53, and for example, a computer such as a microcontroller. The control unit 50 may be composed of a single control unit for centralized control, or may be composed of a plurality of control units for distributed control in cooperation with each other. Further, the storage unit 52 adopts a form arranged in the control unit 50, but the present invention is not limited to this, and a form provided separately from the control unit 50 may be adopted.

The storage unit 52 stores information such as a basic program as a robot controller and various fixed data. The calculation unit 51 reads software such as a basic program stored in the storage unit 52 and executes the software based on the detection signals of the various sensors of the arm 30 and the hands 10 and 20, thereby performing various operations of the robot 100. To control. That is, the calculation unit 51 generates a control command for the robot 100 and outputs the control command to the servo control unit 53. The servo control unit 53 is configured to control the drive of the arm 30 of the robot 100 and the actuators of the hands 10 and 20 based on the control command generated by the calculation unit 51.

<Hand composition>
As shown in FIGS. 1 to 5, the hands 10 and 20 are detachably attached to the tip of the arm 30, for example, via an auto tool changer 60. The hand has one or more (two in this embodiment) robot hands (first hand 10, second hand 20).

The auto tool changer 60 includes an arm adapter 61 and hand adapters 62 and 63. The arm adapter 61 is an adapter attached to the tip of the arm 30, and the hand adapters 62 and 63 are adapters that can be attached to and detached from the arm adapter 61. In this embodiment, the hand adapter has a first hand adapter 62 attached to the first hand 10 and a second hand adapter 63 attached to the second hand 20.

A hand suitable for the work is selected from the first hand 10 and the second hand 20. The hand adapters 62 and 63 of the selected hands 10 and 20 are connected to the arm adapter 61, and the hand adapters 62 and 63 of the other hands 10 and 20 are removed from the arm adapter 61. As a result, the first hand 10 and the second hand 20 are interchangeably attached to the tip of the arm 30.

The first hand 10 has a first base 11, grip portions 12, 13, support portions 14, and drive portions 15, 16. Drive units 15 and 16 are provided on the first base 11, a first hand adapter 62 is arranged on one surface of the first base 11, and grip portions 12, 13 and grip portions 12 and 13 are arranged on the other surface side opposite to one surface. The support portion 14 is arranged. The drive unit includes a first drive unit 15 that drives the grip portions 12 and 13, and a second drive unit 16 that drives the support unit 14.

The grip portions 12 and 13 have one or more (two in this embodiment) grip portions (first grip portion 12 and second grip portion 13). The first grip portion 12 and the second grip portion 13 are members that grip the work 40 in cooperation with each other, and are arranged side by side in the first direction on the first base 11.

The first grip portion 12 has a pair of first claw portions 12a, and the pair of first claw portions 12a are arranged so as to face each other in a second direction orthogonal to the first direction. The second grip portion 13 has a pair of second claw portions 13a, and the pair of second claw portions 13a are arranged so as to face each other in the second direction.

The first drive unit 15 is a linear actuator such as an electric drive actuator and a fluid drive actuator, and drives the first claw portion 12a and the second claw portion 13a. The fluid drive actuator is operated by the pressure of the fluid, and for example, a pneumatic drive device in which air is used as the fluid, a hydraulic drive device in which oil is used as the fluid, and the like are used. The first driving unit 15 moves the first claw portion 12a and the second claw portion 13a in the second direction, so that the distance between the pair of first claw portions 12a and the distance between the pair of second claw portions 13a in the second direction are increased. fluctuate.

The base ends of the first claw portion 12a and the second claw portion 13a are connected to the first base 11, and project from the first base 11 in the third direction orthogonal to the first direction and the second direction. The tip of the first claw portion 12a opposite to the base end side (first tip portion 12b) is bent and has an L shape when viewed from the first direction. The tip of the second claw portion 13a opposite to the base end side (second tip portion 13b) is bent and has an L shape when viewed from the first direction.

The pair of first claw portions 12a extend in a direction in which the first tip portions 12b face each other in the second direction. The pair of second claw portions 13a extend in a direction in which the second tip portions 13b face each other in the second direction. In the third direction, the first tip portion 12b and the second tip portion 13b are provided so as to be at the same position as each other. As a result, the work 40 is stably arranged on the first tip portion 12b and the second tip portion 13b.

The support portion 14 is a member that can be expanded and contracted with respect to the first base 11 and supports the first hand 10. The support portion 14 has one or more stretchable portions 17, and in this embodiment, the support portion 14 has two sets of a pair of stretchable portions 17. This expansion / contraction direction is parallel to the third direction, and the expansion / contraction portion 17 extends along the first claw portion 12a and the second claw portion 13a. The plurality of telescopic portions 17 are parallel to each other, and are provided so that the dimensions between the tip end and the first base 11 when extended are equal to each other.

In the second direction, the pair of telescopic portions 17 are arranged so as to sandwich the first claw portion 12a and the second claw portion 13a between each other. Therefore, the telescopic portion 17 can support the first hand 10 without hindering the gripping of the work 40 by the first claw portion 12a and the second claw portion 13a. Further, the center of gravity can be brought closer to the center of the first hand 10, and the stability of the support can be improved by the support portion 14.

Further, the pair of expansion / contraction portions 17 arranged in the second direction are arranged at intervals from each other, and the two expansion / contraction portions 17 arranged in the first direction are arranged at intervals from each other. In this way, a plurality of (four in this embodiment) expansion / contraction portions 17 are arranged so as to be separated from each other in a direction orthogonal to the expansion / contraction direction (in this embodiment, the first direction and the second direction). There is. Therefore, the area surrounded by the plurality of telescopic portions 17 is expanded, and the first hand 10 can be stably supported.

The telescopic portion 17 has, for example, a tubular member 17a and a rod-shaped member 17b. The tubular member 17a extends in the third direction, its base end is connected to the first base 11, and its tip is open. The rod-shaped member 17b has a smaller diameter than the tubular member 17a, its base end side portion is inserted into the tubular member 17a through an opening, and the tip end side portion extends from the tubular member 17a in the third direction. There is. The tip of the rod-shaped member 17b may have an enlarged diameter.

The second drive unit 16 moves the rod-shaped member 17b with respect to the tubular member 17a. As a result, the relative positions of the tubular member 17a and the rod-shaped member 17b change, and the expansion / contraction portion 17 expands and contracts in the third direction. The telescopic portion 17 is a stretchable portion between a position farther from the first base 11 than the tips of the claws 12a and 13a and a position closer to the first base 11 than the tips of the claws 12a and 13a. The tip of 17 expands and contracts so as to move forward and backward.

The second drive unit 16 is a linear actuator such as an electric actuator and a fluid actuator. As the fluid actuator, a pneumatic drive device in which air is used as the fluid, a hydraulic drive device in which oil is used as the fluid, and the like are used. By using a fluid actuator for the second drive unit 16, the cost of the second drive unit 16 can be reduced as compared with the case where a drive source such as a servomotor is used. By using the hydraulic drive device for the second drive unit 16 among the fluid actuators, the telescopic portion 17 is supported even by the first hand 10 holding the heavy work 40 without increasing the size of the second drive unit 16. can do.

The second drive unit 16 of the fluid actuator has a pump (not shown), a cylinder (not shown), and a piston (not shown), and the pump supplies fluid to the cylinder to provide a fluid in the cylinder. The piston reciprocates. As a result, the second drive unit 16 moves the rod-shaped member 17b in the direction of being inserted into the tubular member 17a and the direction of protruding from the tubular member 17a, and expands and contracts the telescopic portion 17. This expansion and contraction is performed between both ends in the reciprocating stroke of the piston.

The second hand 20 has a second base 21, a nut runner 22, and a drive unit (third drive unit 23). The second base 21 is provided with a third drive unit 23, a second hand adapter 63 is arranged on one side of the second base 21, and a nut runner 22 is arranged on the other side opposite to one side. There is. The third drive unit 23 is a rotary actuator such as an electric actuator and a fluid drive actuator, and rotationally drives the nut runner 22.

<Robot operation method>
In the robot 100, as shown in FIGS. 1 to 5, the operation of transporting the work 40 to the processing machine 41 by the first hand 10 and attaching the work 40 to the fitting 42 by the second hand 20 in the processing machine 41 will be described. .. This operation is controlled by the control unit 50.

Information such as the shape and dimensions of the work 40 is stored in advance in the control unit 50 based on the design data and the like. Further, the second hand 20 is arranged on the work table 43, and the positions of the work table 43 with respect to the robot 100 and the second hand 20 on the work table 43 are stored in advance in the control unit 50.

Further, the processing machine 41 is provided with a plurality of attachments 42 for attaching the work 40 on the pedestal 44. Each position of the processing machine 41 and the fixture 42 with respect to the robot 100 is stored in advance in the control unit 50.

These positions are defined as coordinate positions with the position of the robot 100 (for example, the position of the mounting table 31) as the origin in the Cartesian coordinate system. The control unit 50 controls the positions of the arms 30 and the hands 10 and 20 based on the position information and the information of the work 40.

First, the first hand 10 previously attached to the tip of the arm 30 is moved to the work 40 by the arm 30. Then, in the first hand 10, the distance between the pair of first claws 12a of the first grip 12 is widened, and the distance between the pair of second claws 13a of the second grip 13 is widened. To drive.

Further, the expansion / contraction portion 17 of the support portion 14 is contracted to its shortest dimension by the second drive portion 16. As a result, the tips of the grips 12 and 13 project in the third direction from the tips of the support 14, so that when the first hand 10 is lowered, the support 14 is placed on the floor before the grips 12 and 13. There is no such thing as hitting. Therefore, the first hand 10 is placed on the arm 30 so that the first tip portion 12b of the first claw portion 12a and the second tip portion 13b of the second claw portion 13a of the grip portions 12 and 13 are arranged below the work 40. Move by.

Here, the first drive unit 15 is driven so as to narrow the distance between the pair of first claw portions 12a and the distance between the pair of second claw portions 13a. As a result, the work 40 is sandwiched between the pair of first claw portions 12a and between the pair of second claw portions 13a, and rests on the first tip portion 12b and the second tip portion 13b. When the first hand 10 is raised by the arm 30 in this state, the work 40 is gripped by the gripping portions 12 and 13 of the first hand 10.

In this way, the work 40 is placed on the pair of first tip portions 12b and on the pair of second tip portions 13b. As a result, it is not necessary to pinch the work 40, and even a heavy work 40 of several hundred kg can be gripped without damage.

Then, the work 40 is conveyed to the processing machine 41. Here, the work 40 is directed to a predetermined posture that can be machined by the processing machine 41, and is positioned at the mounting position by the fixture 42.

The position and dimensions of the telescopic portion 17 in the first hand 10 are preset so that the tip of the telescopic portion 17 extended to the longest dimension at this mounting position reaches the pedestal 44. Therefore, when the second drive unit 16 is driven so that the expansion / contraction portion 17 extends, the expansion / contraction portion 17 extends beyond the claw portions 12a and 13a, and the tip thereof reaches the floor surface of the pedestal 44. Then, the auto tool changer 60 is driven so as to remove the first hand 10 from the arm 30. As a result, the first hand 10 grips the work 40 and stands on the floor surface of the pedestal 44 while being supported by the extended telescopic portion 17 in a state where the arm 30 is separated from the first base 11. Therefore, the work 40 in a predetermined posture is held at the mounting position.

Subsequently, the second hand 20 is attached to the tip of the arm 30 by the auto tool changer 60. Then, the nut runner 22 of the second hand 20 is driven by the third drive unit 23, and the screw 45 of the fixture 42 is tightened. As a result, the work 40 is fixed to the processing machine 41 by the attachment 42.

Here, the telescopic portion 17 is provided in the first hand 10 so that the attachment 42 is arranged between the telescopic portions 17 arranged in the first direction. Therefore, the telescopic portion 17 can support the work 40 without hindering the fastening of the screw 45 by the first hand 10.

Then, the second hand 20 is removed from the arm 30 and placed on the workbench 43, and the first hand 10 is attached to the arm 30. Then, the distance between the pair of first claw portions 12a and the pair of second claw portions 13a is widened to release the grip of the work 40, and then the first hand 10 is moved. As a result, the work 40 is ready to be machined in the processing machine 41.

In this way, one robot 100 having one arm 30 uses the first hand 10 and the second hand 20 to convey and hold the work 40 to the processing machine 41, and attach the processing machine 41. It can be attached to the tool 42. Further, by providing the telescopic portion 17 for supporting the work 40 in the first hand 10, the equipment and control can be simplified as compared with the case where the support portion 14 of the work 40 is provided in the processing machine 41.

<Other embodiments>
In the above embodiment, the telescopic portion 17 extends to the longest dimension to support the first hand 10, but the dimension of the telescopic portion 17 is not limited to this. For example, when the expanding / contracting portion 17 comes into contact with the pedestal 44 of the processing machine 41, a load of a predetermined value or more acts on the second driving unit 16, and when this state continues for a predetermined time, the second driving unit 16 moves. The expansion of the expansion / contraction portion 17 may be stopped and the dimensions of the expansion / contraction portion 17 may be determined. Then, the first hand 10 may be supported by the expansion / contraction portion 17 having the determined dimensions.

In the above embodiment, the first grip portion 12 and the second grip portion 13 place the work 40 on the first tip portion 12b of the first claw portion 12a and on the second tip portion 13b of the second claw portion 13a. The work 40 was gripped. However, the method of gripping the work 40 is not limited to this.

For example, the first grip portion 12 and the second grip portion 13 may grip the work 40 by sandwiching the work 40 between the pair of first claw portions 12a and the pair of second claw portions 13a. Alternatively, the first grip portion 12 and the second grip portion 13 have a suction member, and the work 40 may be gripped by sucking the work 40 with the suction member.

In the above embodiment, the information of the work 40 is stored in the control unit 50 in advance based on the design data and the like, but the method of acquiring the information of the work 40 is not limited to this. For example, the robot 100 may have an image acquisition unit (not shown) such as a camera. In this case, an identifier such as a barcode containing the information may be added to the work 40. As a result, the robot 100 can acquire the information of the work 40 from the identifier by the image acquisition unit.

In addition, all the above-described embodiments may be combined with each other as long as the other party is not excluded from each other. Also, the above description should be construed as an example only and the present invention has been provided for the purpose of teaching those skilled in the art the best mode to carry out. The details of its structure and / or function can be substantially changed without departing from the spirit of the present invention.

The robot hand of the present invention is useful as a robot hand or the like for transporting, holding, and attaching a work by one robot.

10: First hand (robot hand)
11: 1st base (base)
12: First grip portion (grip portion)
12a: First claw part (claw part)
12b: First tip portion (tip)
13: Second grip portion (grip portion)
13a: Second claw part (claw part)
13b: Second tip (tip)
14: Support unit 16: Second drive unit (drive unit)
17: Telescopic part 30: Arm 40: Work

Claims (5)

A robot hand that can be attached to and detached from the robot arm
A base that is detachably attached to the arm and
A grip portion provided on the base and gripping the work,
A support that can be expanded and contracted with respect to the base
A drive unit that expands and contracts the support portion is provided.
A robot hand that grips a work by the gripping portion and stands on the floor surface by being supported by the extended support portion in a state where the arm is separated from the base. The support portion expands and contracts so that the tip of the support portion moves back and forth between a position farther from the base than the tip of the grip portion and a position closer to the base than the tip of the grip portion. , The robot hand according to claim 1. The robot hand according to claim 1 or 2, wherein the support portion has a plurality of telescopic portions arranged at intervals in a direction orthogonal to the telescopic direction. The plurality of elastic portions are provided in pairs so as to sandwich the grip portion.
The robot hand according to claim 3. The grip portion has a pair of claw portions that sandwich the work.
The robot hand according to any one of claims 1 to 4, wherein the pair of the claw portions has a base end connected to the base base and the tips are bent in a direction facing each other.

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