JP4545996B2 - Robot hand drive - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a robot hand drive device, and more particularly to a robot hand drive device that is movable while holding a thin substrate such as a semiconductor wafer, a liquid crystal display, or a glass substrate for a plasma display.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a robot having a movable hand holding a thin substrate, such as a SCARA robot, a vertical rotation mechanism unit 32 that rotates the hand 6 about a horizontal axis 31 that coincides with the longitudinal direction of the hand as shown in FIG. There are known types of robots with
[0003]
Then, the robot equipped with the conventional vertical rotation mechanism unit 32 inverts the hand 6 with the arms 4 and 5 extended forward as shown in FIG. 18, or the hand 6 as shown in FIG. Is set at a high position sufficiently away from the first arm 5, so that the thin substrate 8 does not interfere with the arms 4 and 5 when the hand 6 is turned upside down.
[0004]
[Problems to be solved by the invention]
However, in the former case, there is a problem that the footprint (nominal turning range of the robot) is expanded, and in the latter case, there is a problem that the substrate pass line is raised. Moreover, both of them are difficult to apply to a double arm type robot.
[0005]
The present invention solves the problems of the conventional robot as described above, reduces the footprint, prevents the substrate pass line from rising, and can be easily applied to a double-arm robot. With the goal.
[0006]
[Means for solving the problems]
A robot hand drive device according to the present invention is a robot hand drive device that is movable while holding a thin substrate,
A vertical rotation mechanism that rotates the robot hand around a horizontal axis perpendicular to the longitudinal direction of the hand, and a horizontal rotation mechanism that rotates the robot hand around the vertical axis ,
While the robot hand holding the thin substrate is rotated by the vertical rotation mechanism unit, the position of the robot hand in the hand longitudinal direction is controlled so that the center position of the thin substrate is maintained at a fixed position in the hand longitudinal direction. It is characterized by that.
[0008]
The horizontal rotation mechanism unit rotates the robot hand in the horizontal direction by rotating the vertical rotation mechanism unit in the horizontal direction.
[0009]
The robot hand in a horizontal state holding the thin substrate is rotated 90 ° in the vertical direction by the vertical rotation mechanism unit to change to a vertical state, and then the robot hand in the vertical state is changed to the horizontal rotation mechanism. The thin substrate is rotated by 180 ° in the horizontal direction to change the state into the reverse state, and then the robot hand in the reverse direction is turned 90 ° in the vertical direction to change into the reverse state. The robot hand in the horizontal state that is being held is changed to a state where it is turned upside down.
[0010]
A gear backlash suppression mechanism is disposed on the horizontal axis.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 is a side view of a SCARA robot incorporating a robot hand drive device according to an embodiment, and FIG. 2 is a schematic perspective view of a main part of the SCARA robot.
[0013]
1 and 2, the SCARA robot 1 includes a machine base 2, a body 3, a second arm 4, a first arm 5, and a hand 6. Known pulleys, timing belts, and the like are arranged inside the first arm 5 and the second arm 4, and the hand 6 basically moves up and down the body unit 3 in the same manner as a known SCARA robot hand. The second arm 4 and the first arm 5 are configured to move up and down and turn on the basis of the turning operation, and to move on a straight orbit on the horizontal plane. Further, in the case of the present embodiment, the hand 6 is a vacuum suction type hand, and sucks and holds the glass substrate 8 on the upper surface 6a side in a normal state, that is, a state where the hand 6 is not turned upside down.
[0014]
The driving device 7 is disposed in the base portion 6 b of the hand 6, and includes a vertical rotation mechanism unit 100 and a horizontal rotation mechanism unit 200.
[0015]
The vertical rotation mechanism unit 100 has a mechanism for rotating the hand 6 about a horizontal axis 9 orthogonal to the longitudinal direction of the hand, and the hand 6 has a maximum of 180 ° + α (α is a correction angle in consideration of bending of the hand 6). .) Can be rotated.
[0016]
The horizontal rotation mechanism unit 200 has a mechanism for rotating the hand 6 around the vertical axis 51, and the hand 6 can rotate at a maximum of 180 ° + α (α is a correction angle considering the bending of the hand 6). .
[0017]
3 is a cross-sectional view of the vertical rotation mechanism unit 100 and the horizontal rotation mechanism unit 200 as viewed from the front, FIG. 4 is a plan view showing a configuration inside the housing of the vertical rotation mechanism unit 100, and FIG. Sectional drawing which looked at 200 from the side, FIG. 6: each shows explanatory drawing of a gear backlash suppression mechanism.
[0018]
In FIG. 3, the horizontal rotation mechanism 200 includes a bracket 52 that is fixed to a pulley (not shown) inside the first arm 5, and a motor 53 is held by the bracket 52. A small diameter gear 54 is fixed to the output shaft of the motor 53, and a large diameter gear 55 is engaged with the small diameter gear 54. The large-diameter gear 55 is rotatably held on the outer periphery of the cylindrical portion 57 of the bracket 52 via a bearing 56. The upper portion of the large-diameter gear 55 is fixed to the flange portion 60, and the flange portion 60 is fixed to the lower end portion of the housing 10 of the vertical rotation mechanism portion 100.
[0019]
When the motor 53 is stopped, the horizontal rotation mechanism unit 200 keeps the rotation position of the housing 10 of the vertical rotation mechanism unit 100 having the vertical shaft 51 as the rotation axis constant by the meshing of the small diameter gear 54 and the large diameter gear 55. When the motor 53 rotates, the large-diameter gear 55 rotates through the small-diameter gear 54 and rotates the housing 10 around the vertical shaft 51. The horizontal rotation mechanism 200 of the present embodiment is a combination of a small diameter gear 54 and a large diameter gear 55. Alternatively, a combination of a pulley and a belt, a combination of a worm shaft and a worm wheel, or a direct drive. It can also be realized by a motor.
[0020]
3 to 6, the vertical rotation mechanism unit 100 includes a horizontal axis (reversal axis) 9 that is fixed to the base portion 6 b of the hand 6 and that is orthogonal to the linear trajectory (longitudinal direction) of the hand 6.
The horizontal shaft 9 is rotatably held by bearings 11 and 12 disposed in the housing 10, and a worm wheel 13 is fixed to one end of the horizontal shaft 9. The worm wheel 13 meshes with a worm shaft 14 arranged in parallel with the straight track of the hand 6, and the worm shaft 14 is fixed to a pulley 15. A motor 16 is disposed inside the housing 10. A pulley 17 is fixed to the output shaft of the motor 16, and a timing belt 18 is stretched between the pulley 17 and the pulley 15.
[0021]
In the vertical rotation mechanism 100, when the motor 16 is rotated for a predetermined period while the hand 6 is maintained in the normal state shown by the solid line in FIG. 2, a power transmission mechanism (pulley 17, timing belt 18, pulley 15, worm) The horizontal shaft 9 rotates via the shaft 14 and the worm wheel 13), and the hand 6 can be changed to a vertical state shown by a two-dot chain line in FIG. Thereafter, after the hand 6 is rotated about the vertical axis 51 by 180 ° in the vertical state, when the motor 16 is rotated in the same direction as the rotation direction for a predetermined period, the power transmission mechanisms 17, 18, 15, 14, 13 are interposed. Thus, the horizontal shaft 9 rotates and the hand 6 can return to the normal state. Incidentally, the hand 6 may be rattled by the backlash of the gear devices 14 and 13 in the vicinity of the vertical state as shown in FIG. For this reason, it is preferable to provide a gear backlash suppression mechanism. The coil spring 41 shown in FIG. 3 constitutes a first gear backlash suppressing mechanism. The coil spring 41 is externally fitted to the horizontal shaft 9, and is configured to apply a force in the opposite direction to the horizontal shaft 9 when the horizontal shaft 9 rotates in the vertical direction, thereby preventing backlash. . 6B and 6C conceptually show the configuration of the second gear backlash suppression mechanism. This gear backlash suppression mechanism is configured by arranging a rotor portion 21 that rotates integrally with the horizontal shaft 9 between a pair of leaf springs 19 and 20 arranged to face each other. The rotor unit 21 includes rollers 22 and 23 that can come into contact with the leaf springs 19 and 20 at both ends. When the hand 6 is in the normal state, the rotor portion 21 is in a state where the two rollers 22 and 23 are separated from the pair of leaf springs 19 and 20 as shown in FIG. Before the hand 6 is rotated by 90 ° from the normal state, contact with the pair of leaf springs 19 and 20 is started to elastically deform the leaf springs 19 and 20, and when the hand 6 is rotated by 90 °, FIG. As shown, it operates to receive a sufficiently large elastic restoring force (pressing force) from the pair of leaf springs 19 and 20. As a result, backlash can be prevented and the hand 6 does not rattle. Only one or both of the first and second gear backlash suppression mechanisms described above may be provided.
[0022]
When the hand 6 rotates around the horizontal axis 9, the hand 6 is rotated while the horizontal axis 9 maintains a fixed position on the linear track, in other words, the hand without moving the first arm 5 and the second arm 4 at all. Although it is not intended to positively exclude rotating only 6, considering the wind pressure received by the glass substrate 8 when the hand 6 is rotated, the hand 6 is rotated while changing the position of the horizontal axis 9 on the straight track. In other words, it is preferable to rotate the hand 6 while moving the first arm 5 and the second arm 4. In this case, as shown in FIG. 7, the operations of the first arm 5 and the second arm 4 are controlled so as to maintain the center position of the glass substrate 8 at a fixed position in the linear trajectory direction. The position in the orbit direction is controlled. Such control is performed based on arithmetic processing by a control circuit (not shown).
[0023]
Next, a series of operation examples of the SCARA robot 1 configured as described above will be described with reference to FIGS.
[0024]
First, as shown in FIGS. 8A and 8B, the SCARA robot 1 is directly opposed to the cassette 24 in order to take out the glass substrate 8 from the cassette 24. Next, as shown in FIGS. 9A and 9B, the hand 6 is advanced to just below the glass substrate 8 to be taken out, the hand 6 is raised, and the glass substrate 8 is placed on the upper surface 6a of the hand 6 and sucked. To do. Next, as shown in FIGS. 10A and 10B, the hand 6 is retracted to the same position as in FIGS. 8A and 8B. Next, the hand 6 is rotated about the horizontal axis 9 by 90 ° by the vertical rotation mechanism unit 100. During this rotation, as described above, the operations of the first arm 5 and the second arm 4 are controlled so as to maintain the center position of the glass substrate 8 at a fixed position in the linear trajectory direction. The position in the linear trajectory direction is controlled. FIGS. 11A and 11B show the configuration of the SCARA robot 1 when the glass substrate 8 is in a vertical state during this rotation. Next, the hand 6 is rotated around the vertical axis 51 by the horizontal rotation mechanism unit 200, and the SCARA robot 1 is in the state shown in FIGS. 12A and 12B, that is, the front and back of the hand 6 are reversed. To do. Next, the hand 6 is rotated by 90 ° around the horizontal axis 9 so as to return to the horizontal state substantially the same as that shown in FIGS. During this rotation, the first arm 5 and the second arm are maintained so that the center position of the glass substrate 8 is maintained at a fixed position in the linear trajectory direction, similar to the case where the hand 6 is rotated around the horizontal axis 9 as described above. 4 is controlled. FIGS. 13A and 13B show the configuration of the SCARA robot 1 when the hand 6 returns to the horizontal state. The hand 6 is turned upside down from the state shown in FIG. The holding surface which becomes the upper surface 6a is located on the lower side, and the glass substrate 8 is sucked and held from below by this holding surface. Next, after the body 3 is turned 180 ° to make the SCARA robot 1 as shown in FIGS. 14A and 14B, the hand 6 is moved forward as shown in FIG. A glass substrate 8 is placed on the substrate.
[0025]
As described above, the driving device 7 of the robot hand 6 according to the present embodiment is a driving device of the robot hand that can move while holding the thin substrate (glass substrate) 8 and is horizontal that is orthogonal to the longitudinal direction of the hand. A vertical rotation mechanism unit 100 that rotates the robot hand 6 around the axis 9 and a horizontal rotation mechanism unit 200 that rotates the robot hand 6 around the vertical axis 51 are provided. According to the present embodiment, with the arms 4 and 5 of the robot 1 in a bent state, the hand 6 in the horizontal state is rotated 90 ° in the vertical direction by the vertical rotation mechanism unit 100 to change to the vertical state. Next, the hand 6 in the vertical state is rotated 180 ° in the horizontal direction by the horizontal rotation mechanism unit 200 to change into the front-rear inverted state, and then the hand 6 in the front-rear inverted state is rotated 90 ° in the vertical direction. Thus, the horizontal hand 6 holding the thin substrate 8 can be turned upside down by changing the state to the upside down state. During this time, the interference between the thin substrate 8 and the arms 4 and 5 can be changed. Does not occur, the footprint is reduced. Further, even if the hand 6 is set at a height position close to the arms 4 and 5, the hand 6 can be reversed without causing interference between the thin substrate 8 and the arms 4 and 5. Can be prevented from rising.
[0026]
Further, in the present embodiment, while the robot hand 6 holding the thin substrate 8 is rotated by the vertical rotation mechanism unit 100, the center position of the thin substrate 8 is maintained at a fixed position in the linear trajectory direction (hand longitudinal direction). The position of the robot hand 6 in the linear trajectory direction (hand longitudinal direction) is controlled. For this reason, the wind pressure which the thin board | substrate 8 receives at the time of rotation of the hand 6 can be decreased, and the increase in the rotational speed of the hand 6 can be aimed at.
[0027]
Further, by providing a gear backlash suppression mechanism (a pair of leaf springs 19 and 20, rotor portion 21, rollers 22 and 23, coil spring 41), the gear devices 14 and 13 when the hand 6 passes near the vertical state. The backlash of the hand 6 due to backlash can be prevented.
[0028]
In the above embodiment, the robot for transporting the glass substrate 8 has been described. Needless to say, the robot can be easily applied to a robot for transporting other thin substrates such as a semiconductor wafer instead of the glass substrate 8. It can also be applied to articulated robots.
[0029]
16 (A) and 16 (B) show another embodiment of the present invention. In this embodiment, a vertical rotation mechanism unit 100 and a horizontal rotation are provided on an upper hand 27 of a conventionally known double-arm type SCARA robot 26. A mechanism unit 200 is provided. The vertical rotation mechanism unit 100 and the horizontal rotation mechanism unit 200 are configured and operate in the same manner as in the above-described embodiment.
[0030]
17 (A) and 17 (B) show still another embodiment. In this embodiment, the vertical rotation mechanism unit 100 and the hand 29 on the upper side of a conventionally known double arm type direct acting robot 28 are shown. A horizontal rotation mechanism unit 200 is provided. The vertical rotation mechanism unit 100 and the horizontal rotation mechanism unit 200 are configured and operate in the same manner as in the above-described embodiment.
[0031]
As is apparent from FIGS. 16 and 17, the present invention can be easily applied to the double arm type robots 26 and 28.
[0032]
【The invention's effect】
According to the present invention, when the hand is finally reversed, the footprint can be reduced and the rise of the substrate pass line can be prevented. Further, it can be easily applied to a double arm type robot.
[Brief description of the drawings]
FIG. 1 is a side view of a single-arm SCARA robot incorporating a robot hand drive device according to an embodiment of the present invention.
FIG. 2 is a schematic perspective view of a main part of the SCARA robot.
FIG. 3 is a cross-sectional view of the driving device (vertical rotation mechanism and horizontal rotation mechanism) as viewed from the front.
FIG. 4 is a plan view showing a configuration inside a housing of a vertical rotation mechanism.
FIG. 5 is a cross-sectional view seen from the side of the vertical rotation mechanism.
FIG. 6 is an explanatory diagram of a gear backlash suppressing mechanism.
FIG. 7 is a state displacement diagram of the glass substrate when the hand rotates around the horizontal axis.
FIG. 8 is a perspective view and a side view showing a series of operation examples of the SCARA robot.
FIG. 9 is a perspective view and a side view showing a series of operation examples of the SCARA robot.
FIG. 10 is a perspective view and a side view showing a series of operation examples of the SCARA robot.
FIG. 11 is a perspective view and a side view showing a series of operation examples of the SCARA robot.
FIG. 12 is a perspective view and a side view showing a series of operation examples of the SCARA robot.
FIG. 13 is a perspective view and a side view showing a series of operation examples of the SCARA robot.
FIG. 14 is a perspective view showing a series of operation examples of the SCARA robot.
FIG. 15 is a perspective view showing a series of operation examples of the SCARA robot.
FIGS. 16A and 16B are a perspective view and a front view of a SCARA robot of a double arm specification according to another embodiment of the present invention. FIGS.
FIGS. 17A and 17B are a perspective view and a front view of a double-armed direct acting robot according to still another embodiment of the present invention. FIGS.
FIG. 18 is a perspective view showing a problem of a vertical rotation mechanism unit of a conventional SCARA robot.
FIG. 19 is a side view showing a problem in the vertical rotation mechanism of the conventional SCARA robot.
[Explanation of symbols]
4, 5 arm 6 hand (robot hand)
7 Driving device 8 Glass substrate (thin substrate)
9 Horizontal shafts 19, 20 A pair of leaf springs (gear backlash suppression mechanism)
21 Rotor (gear backlash suppression mechanism)
22, 23 Roller (Gear backlash suppression mechanism)
41 Coil spring 51 Vertical axis 100 Vertical rotation mechanism 200 Horizontal rotation mechanism

Claims (4)

A robot hand drive device that can move while holding a thin substrate,
A vertical rotation mechanism that rotates the robot hand around a horizontal axis perpendicular to the longitudinal direction of the hand, and a horizontal rotation mechanism that rotates the robot hand around the vertical axis ,
While the robot hand holding the thin substrate is rotated by the vertical rotation mechanism unit, the position of the robot hand in the hand longitudinal direction is controlled so that the center position of the thin substrate is maintained at a fixed position in the hand longitudinal direction. A robot hand drive device characterized by that. 2. The robot hand driving apparatus according to claim 1, wherein the horizontal rotation mechanism unit rotates the robot hand in the horizontal direction by rotating the vertical rotation mechanism unit in the horizontal direction . The robot hand in a horizontal state holding the thin substrate is rotated 90 ° in the vertical direction by the vertical rotation mechanism unit to change to a vertical state, and then the robot hand in the vertical state is changed to the horizontal rotation mechanism. The thin substrate is rotated by 180 ° in the horizontal direction to change the state into the reverse state, and then the robot hand in the reverse direction is turned 90 ° in the vertical direction to change into the reverse state. 3. The robot hand driving device according to claim 1 , wherein the robot hand in a horizontal state being held is changed to a state where the robot hand is turned upside down . 4. The robot hand drive device according to claim 1, wherein a gear backlash suppressing mechanism is disposed on the horizontal axis .

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