JPH03111190A - Robot hand - Google Patents

Abstract

PURPOSE:To use plural tools with the selection without performing the exchanging work by a single motor and sliding mechanism, by making the end part of each ball spline as a tool fitting part. CONSTITUTION:When a motor 3 is rotated, all of 2nd gears 121, 122 and 3rd gears 131, 132 are rotated via a speed reducing device 6, driving shaft 4 and 1st gear 7, all of cylindrical parts 101, 102 are therefore rotated and all of ball splines 171, 172 are rotated therefore. The tools fitted to the tool fitting parts 211, 212 which are the lower end parts of the ball splines 171, 172 are thus rotated and the postures thereof are controlled. The air cylinder 23 where the ball spline 17 fitted with a using tool is connected is then driven, the ball spline 17 is descended and the tool fitted to the ball spline 17 arrives at a work position.

Description

DETAILED DESCRIPTION OF THE INVENTION The robot hand of the present invention will be described in detail according to the following items.

A Industrial field of application B4 Summary of the invention C Prior art and its problems One means for solving the problem E Examples [Figures 1 to 3] a6 Structure Effect F Effect of the invention (A, INDUSTRIAL APPLICATION FIELD The present invention relates to a novel robot hand. Specifically, it is possible to select and use multiple tools as needed without having to replace them, and moreover, it can be realized with a single drive source, and the space for selecting tools is small. The aim is to provide a new robot hand that can be used easily.

(B. Summary of the Invention) The robot hand of the present invention is a robot hand that has a plurality of tool attachment parts and is attached to the processing tip of the robot, and has a plurality of tools attached to a first gear rotated by a single motor. The second gear meshes with the second gear, has a rotation axis coaxial with the rotation axis of each second gear, is slidably inserted into the cylindrical part rotated together with the second gear, and is integral with the cylindrical part. A sliding mechanism is provided for sliding each ball spline individually in its axial direction, and the end of each ball spline is used as a tool attachment part, whereby the tool attachment for each ball spline is provided. By attaching tools to each section separately, you can use a single motor and sliding mechanism to selectively use multiple tools without having to change them. Since it is not necessary, the space for tool selection can be small.

(C. Conventional technology and its problems) In recent years, there has been an increasing demand for various electrical equipment to be lighter and smaller, and the production equipment has also been forced to be smaller.
For this reason, even higher processing precision is required. Furthermore, consumer electronic equipment is becoming increasingly individualized, which requires high-mix, low-volume production, and flexibility in production equipment.

Due to this situation, production equipment lines using robots are often set up as production equipment, and for high-precision machining, horizontal articulated robots are used as relatively compact robots in the same way as vertical articulated robots. It became so.

On the other hand, although the structure of horizontal articulated robots is designed to be similar to the structure of a human arm and is easy to use,
The accuracy with which the tool is positioned at a desired position in the horizontal plane is not determined only by the accuracy of the joint axis, but also varies depending on the position in the horizontal plane. This is due to the fact that even if the two joints have -like accuracy, the uniformity in the Cartesian coordinate system cannot be maintained when converted to the Cartesian coordinate system on the horizontal plane, and this causes the retraction of the two joints. Horizontal articulated robots cannot always be used for parts that require high assembly processing accuracy and are not highly accurate due to the quality of the wood, just because they are easy to use.

Therefore, in recent years, orthogonal coordinate system robots have been used for precision machining processes, and it has become possible to ensure considerable accuracy. However, Cartesian robots cannot move at the same speed as horizontal articulated robots, and the part that connects the tool has a single head (a head that can be attached to a single tool) like in horizontal articulated robots. When using a robot, tools must be replaced frequently when one robot performs multiple tasks, and replacement tools are usually placed at the edge of the work area, resulting in low costs. Combined with the moving speed, a long time is consumed just for tool exchange, making the takt time extremely long.

In addition, a method has been proposed (Japanese Patent Laid-Open No. 100391/1983) in which the tool is installed on a horizontal articulated robot and rotated to exchange the tool. In such a device, a large volume is required to rotate the tool group especially when changing tools, and in the case of an orthogonal type robot with a narrow working space, the operating range is further narrowed, which makes it difficult for nearby assistants. Furthermore, this structure is dangerous when an operator is working with his/her head close to the head for debugging, teaching, etc., and also causes fear to the operator.

However, in a production line where a single long tool like the one mentioned above is used on a Cartesian robot and the robot performs only a single work process, it may have a significant impact on the throughput. As a result, there is a problem that even if you invest in robots, you will not be able to get the full effect of your investment.

(D. Means for Solving the Problems) In order to solve the above-mentioned problems, the robot hand of the present invention is a robot hand that has a plurality of tool attachment parts and is attached to the processing tip of the robot. A plurality of second gears are meshed with a first gear rotated by one motor, and a cylindrical part having a rotation axis coaxial with the rotation axis of each second gear and rotated together with the second gear has a shaft. A ball spline is provided that is slidably inserted in the axial direction and is rotated integrally with the cylindrical portion, and a sliding mechanism that slides each ball spline individually in its axial direction is provided, and an end portion of each ball spline is provided. is used as the tool mounting part.

Therefore, according to the robot hand of the present invention, by attaching each tool to the tool attachment part of each ball spline, it is possible to replace multiple tools using a single motor and sliding mechanism. It can be used selectively, and can be used with orthogonal robots to significantly shorten tight times. Further, since there is no need to rotate the tool group for tool selection, the space for tool selection is small, which is convenient for the operator.

(Embodiment E) [FIGS. 1 to 3] The details of the robot hand of the present invention will be described below according to the illustrated embodiment 1.

(A Configuration) 2 is a housing, and a mounting mechanism (not shown) is used to attach the machining tip of a robot (not shown), for example, the X of a Cartesian robot.
It is designed to be attached to Y13 moving parts.

Reference numeral 3 denotes a motor, which is fixed at the center of the upper part of the housing 2. As this motor 3, for example, a DC servo motor is used.

4 is a drive shaft, and bearings 5.5, .
It is rotatably supported by...

Reference numeral 6 denotes a speed reduction device, and the output lll113a of the motor is connected to the drive 1jl4 via the speed reduction device 6.

7 is a first gear fixed slightly below the center of the drive shaft 4.

Reference numeral 8 denotes a thorn (agricultural tool) having a substantially semicircular plate shape, the radius of which is slightly larger than the radius of the first gear 7, and its center is located on the upper surface of the first gear 7. It is fixed in the same state. Therefore, the outer peripheral edge of the dog 8 is projected from the outer peripheral edge of the first gear 7.

Reference numeral 9 denotes a photo-interrupter type sensor provided at a position closer to the side within the housing 2, and its detection portion 9a is placed on the movement locus of the thorn 8, and the position of the thorn 8 is determined by this sensor 9. It is now detected.

10H, 102, 103, and 104 are bearings 11 and 11 located at the bottom of the housing 2 at positions surrounding the drive shaft 4 when viewed from above.
,... is a cylindrical part rotatably supported.

Note that the four cylindrical parts 10. ．． 102.103,jO4
and the configurations related to these are all the same, so in the drawings, "x1", "x2", "x3J, rx," respectively.
They are distinguished by adding a subscript, ``J'', but in the following description of the configuration, they will be representatively explained using numbers without a subscript.

A second gear 12 is fixed to the upper end of the cylindrical portion 10, and its rotation axis is coaxial with the rotation axis of the cylindrical portion 10, and is meshed with the first gear 7.

13 is a cylindrical portion 1 which is overlapped directly below the second gear 12.
0, its rotation axis is the same as the rotation axis of the second gear 12 and the cylindrical part 10, and its number of teeth and pitch are the same as the second gear 12. Therefore, the position of the teeth is slightly shifted from that of the second gear 12. And, such a third gear 13 also has the above-mentioned first gear.
It is meshed with gear 7 of.

Reference numeral 14 denotes a boss body that is fitted and fixed within a large diameter portion formed in the lower half of the cylindrical portion 10. A hole 15 is provided through the center of the boss body 14, and a hole 15 is provided through the center of the boss body 14. A plurality of key grooves 16, 16, . . . extending in the axial direction are formed on the inner circumferential surface of.

Reference numeral 17 denotes a ball spline, which is disposed so as to pass through the cylindrical portion 10, and has a key groove 18 formed on its outer peripheral surface.
18, . . . are key grooves 16 formed in the boss body 14.
．． 16, . . . in a slidable manner. As a result, the ball spline 17 can freely slide in the axial direction relative to the cylindrical portion 10, but rotates integrally with the cylindrical portion 10. The rotational axis of the ball spline 17 is coaxial with the rotational axis of the cylindrical portion 10 and the second and third gears 12.13.

An air passage hole 19 is provided through the center of the ball spline 17.

An air hose 20 is connected to the upper end of the ball spline 17 via a port joint 21 that is rotatable with respect to the ball spline 17, and its end communicates with the air passage hole 19 of the ball spline 17, and the other end communicates with the air passage hole 19 (not shown). Connected to the control unit.

The lower end portion 22 of such a ball spline 17 is
or tool attachment part. And this tool mounting part 2
The tools taken in 2 are driven by air sent through the air hose 20 and air hole 19 as necessary. Further, this air hole can also be used for chucking (vacuum chuck) the tool to the tool mounting portion 22 by suctioning the air under reduced pressure.

Reference numeral 23 denotes an air cylinder fixed at a position near the periphery in the vertical center of the housing 2, the axial direction of which extends in the vertical direction, and the piston 24 thereof protruding downward.

Reference numeral 25 denotes a connecting portion provided at the lower end of the piston 24, and an annular engagement groove 25a is formed on the outer peripheral surface of the connecting portion.

26 is a connecting plate, and the upper end of the ball spline 17 is rotatably supported in a support hole 27a formed in the boss portion 27 and provided with a bearing 28.

The upper end of the ball spline 17 has a smaller diameter than the other parts, has an upward step 29 formed therein, and the upper half of the upper end is a helical shaft part 30 in which a threaded groove is formed. A portion 31 between the step portion 29 and the step portion 29 is supported by the bearing 28 . A locking nut 32 is screwed onto the threaded shaft portion 30 of the ball spline 17, and the lower end of the locking nut 32 is in contact with the inner race of the bearing 28. In this way, the upper end of the ball spline 17 is rotatably supported by the connecting plate 26.

A U-shaped engagement notch 33 is formed on the side edge of the connection plate 26, and the engagement notch 33 is engaged with the engagement groove 25a of the connection portion 25. In this way, the ball spline 17
The upper end of the air cylinder 23 is connected to the piston 24 of the air cylinder 23 via a connecting plate 26 .

Note that 34 is a tool attachment portion provided at the bottom of the housing 2 where the cylindrical portion 10 is not provided, and a tool that does not require rotation is attached here.

(b. Effect) In the robot hand 1, when the motor 3 rotates, the rotation is transmitted to all the second gears 12+, +22, +2
3.124 and 3rd gear +31.132.133.1
34 is rotated, therefore all cylindrical parts +01.102
．． 103, 104 are rotated, and thus all ball splines 171, 172, 173, 174 are rotated. As a result, Hall's Flyne 171, +7. , +
73.174's lower end part 21+,
A tool (not shown) attached to 222.223.22a is rotated and its attitude is controlled.

Then, the air cylinder 23 connected to the ball spline 17 to which the tool to be used is attached is driven, the ball spline 17 is lowered, and the tool attached to the ball spline 17 reaches the working position.

Then, among the four ball splines 17, the ball spline 17 to which the tool that needs to be used is attached is positioned on the xY axis, the motor 3 is rotated to adjust the attitude of the tool, and the air cylinder 23 is driven. A desired tool can be selected and used by lowering the Hall spline 17. It is of course possible to use multiple tools at the same time.

Therefore, tools can be selected quickly and takt time can be shortened.

Moreover, there is no need to rotate the attached tools for tool selection, which not only requires a small space for tool selection, but also poses no danger to the operator.

Furthermore, since only one motor 3 is required, the device can be manufactured at low cost.

Also, a second gear 7 fixed to the drive shaft 4 and a cylindrical portion 10
The connection is made with two gears 12 with slightly smoothed teeth.
．． 13, backlash can be eliminated and the attitude of the tool can be controlled accurately.

(F. Effect of the invention) As is clear from the above description, the robot hand of the present invention has a plurality of tool-picking parts, and has a robot hand that can be picked up (taken) from the processing tip of the robot. , a motor, and a first motor rotated by the drive shaft of the motor.
, a plurality of second gears arranged to mesh with the first gear, and a rotation shaft that is coaxial with the rotation 61+ of the gear of each group 2, and the rotation of the second gear. a plurality of cylindrical parts that are rotated in accordance with the cylindrical parts; a plurality of ball splines that are individually inserted into the center of each of the cylindrical parts so as to be slidable in the axial direction and rotated integrally with the cylindrical parts; It is characterized by comprising a sliding mechanism for sliding each ball spline in its axial direction, and that the end of each ball spline is a tool-receiving part.

Therefore, according to the robot hand of the present invention, by storing a separate tool in the tool mounting portion of each ball spline, a plurality of tools can be replaced by a single motor and sliding mechanism. It can be used in a Cartesian 6-type robot to significantly shorten takt time. Further, since there is no need to rotate the tool group for tool selection, the space for tool selection is small, and there is little danger to the operator, and there is no fear to the operator.

It should be noted that the specific structures shown in the above embodiments are merely examples for embodying the present invention, and the technical scope of the present invention should not be construed as limited by these.

[Brief explanation of drawings]

The drawings show an example of the implementation of the robot hand of the present invention, in which FIG. 1 is a perspective view, FIG. 2 is a longitudinal sectional view, and FIG. 3 is a sectional view taken along the line III--III in FIG. 2. Explanation of symbols 1...Ropop] Hunt, 3...Motor, 4...
・・Drive shaft, 6 ・・Reduction gear, 7 ・ 12 ・ 13 ・ 7 2 23 ・・First gear, 10 ・Second gear, ・Third gear, ・Ball spline, ・Tool installation part, ・Air cylinder cylindrical part,

Claims (4)

[Claims] (1) A robot hand having a plurality of tool attachment parts and attached to the processing tip of the robot, the robot hand meshing with a motor, a first gear rotated by a drive shaft of the motor, and the first gear. a plurality of second gears arranged as shown in FIG. and a plurality of ball splines that are individually inserted into the center of each of the cylindrical parts so as to be slidable in the axial direction and rotated integrally with the cylindrical part, and each of the ball splines that can be individually slid in the axial direction. A robot hand comprising a sliding mechanism that allows the robot to move, and an end of each of the ball splines described above is used as a tool attachment part. (2) The robot hand according to claim 1, characterized in that the driving force of the motor is transmitted to the first gear via a reduction gear. (3) A state in which the rotation axis is provided parallel to the second gear so that it is coaxial with the rotation axis of the second gear, and the gear teeth are shifted around the rotation axis with respect to the gear teeth of the second gear. Claim 1, characterized in that a third gear disposed in the cylindrical portion is provided to prevent backlash from occurring in meshing between the first gear and the second gear.
Robot hand described in paragraph or paragraph 2 (4) The robot hand according to claim 1, 2, or 3, characterized in that an air cylinder is used for the sliding mechanism.