JP2007283436A - Robot, robot system, and attitude control method of hand device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a rigidity of a hand device and to suppress an enlargement in size of a robot and steep rise of the cost. <P>SOLUTION: A robot system 100 is equipped with a plurality of hands 51, 52, a vertical movement mechanism 53 which vertically moves one end of each hand and changes an inclination angle relative to a horizontal surface of a holding surface of a workpiece 12 in the hand, a storage means which stores the holding surface of the workpiece in the hand for each loading state of the workpiece on the hand or moving state of the hand by associating the rotation angle of a rotary shaft 61 when matching to the horizontal surface, a detection means for detecting the rotation angle of the rotary shaft, and a control means which performs the control for rotating the rotary shaft by a drive means 62 so that the rotation angle of the rotary shaft detected by the detection means becomes to be the loading state of the workpiece to the hand when being detected, the loading state of the workpiece to the hand stored in the storage means matching to the operating state of the hand, or the rotation angle corresponding to the operating state of the hand. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a robot for transporting a glass substrate for a flat display panel, a robot system having the robot, and a posture control method for a hand device using the robot system.

In a production process of a liquid crystal display panel or a plasma display panel, a conveyance facility using a robot is often used to convey the material within the production process. In general, a robot takes out a glass substrate stored in a cassette and supplies it to a process apparatus, stores a glass substrate that has been processed in a process step in a cassette, or uses a conveyor between conveyors with different heights. It is often used for
Many robots used in such applications have a vertical articulated type or cylindrical coordinate type structure, and are equipped with a hand device with a hand at the tip, often scooping up a glass substrate from below with a hand. Transport. Further, in order to increase the production efficiency of the line, it is required to increase the operation speed of the robot. On the other hand, due to the widespread use of large-sized televisions and the like, the tendency for glass substrates to increase in size has become stronger.

However, in order to insert and remove the hand without interfering with the narrow gap of the glass substrate stored horizontally in the cassette, the robot can operate with or without the glass substrate placed on the hand. It is necessary to maintain the posture so that the hand is as horizontal as possible regardless of the movement position of the robot, and it is also necessary to reduce the vibration of the hand due to the movement of the robot.
For this reason, a method of increasing the rigidity of the robot by adopting a large reduction gear or bearing for each joint portion of the robot can be considered, but there is a problem that the robot becomes larger and the cost becomes higher. Although a method of forming the hand with a special material having high rigidity is also conceivable, there is a problem that the cost increases because the material cost increases.

Therefore, a structure in which the entire hand is tilted so as to keep the hand horizontal is disclosed (for example, see Patent Documents 1 and 2).
JP 11-25550 A JP 2001-71291 A

  However, in the inventions described in Patent Documents 1 and 2, since the tilt axis performs the tilt of the hand in a state where the full load of the hand device is applied, a large moment of inertia is applied to the output axis of the tilt axis. There is a problem that the hand becomes smaller and the hand is likely to vibrate. Therefore, in order to solve this problem, a larger reduction gear and a bearing have to be used, and as described above, it has not been possible to solve problems such as an increase in the size of the robot and an increase in cost.

  Accordingly, the present invention has been made to solve the above-described problems, and can improve the rigidity of the hand device, and can control the posture of the robot, the robot system, and the hand device that suppresses the increase in size and cost of the robot. It aims to provide a method.

  The invention according to claim 1 is a robot including a hand device that moves in a vertical direction and a horizontal direction to grip a workpiece placed at a predetermined place and conveys the workpiece to another place. And a vertical movement mechanism that moves one end of each hand up and down to change the inclination angle of the gripping surface of the workpiece with respect to the horizontal plane.

  According to a second aspect of the present invention, in the robot according to the first aspect, the vertical movement mechanism includes a bracket to which the hand is rotatably fixed, and a rotary shaft that is rotatably fixed to the bracket around an axis. Driving means for rotating the rotating shaft, an eccentric shaft pivotally supported at a position eccentric to the axis of the rotating shaft, one end rotatably connected to one end of the hand, and the other end And a link that is rotatably supported by the eccentric shaft and connected so that one end of the hand moves up and down by the rotation of the eccentric shaft.

  According to a third aspect of the present invention, in the robot according to the second aspect, the driving means is a servo motor.

  According to a fourth aspect of the present invention, there is provided the robot according to the second or third aspect, wherein the eccentric shaft is associated with a difference in deflection amount of each hand depending on a load state of a work on the hand or an operation state of the robot. An amount of eccentricity with respect to the rotating shaft is set.

  According to a fifth aspect of the present invention, there is provided a robot system comprising: the robot according to any one of the second to fourth aspects; a workpiece loaded on the hand; A storage unit that associates and stores a rotation angle of the rotation shaft when the gripping surface is made to coincide with a horizontal plane, a detection unit that detects a rotation angle of the rotation shaft, and a rotation unit that is detected by the detection unit. Corresponding to the loading status of the workpiece on the hand and the operating status of the robot stored in the storage means that coincides with the loading status of the workpiece on the hand and the operating status of the robot when the rotation angle is detected Control means for performing control to rotate the rotating shaft by the driving means so as to achieve a rotation angle.

  According to a sixth aspect of the present invention, in the posture control method for a hand device that controls the posture of the hand device by the robot system according to the fifth aspect, a detection step of detecting a rotation angle of the rotary shaft by the detection means; The rotation angle of the rotary shaft detected by the detection step matches the loading state of the work on the hand and the operating state of the robot when the rotation is detected. And a control step of performing control to rotate the rotating shaft by the driving means so as to have a rotation angle corresponding to a workpiece loading state and a robot operation state.

According to the first aspect of the present invention, one end of each hand can be moved up and down by the vertical movement mechanism, and the inclination angle of the gripping surface of the workpiece in the hand with respect to the horizontal plane can be changed.
As a result, a motor having a small driving force can be adopted as a driving source for correcting the deflection / tilt of the hand, and the weight of the hand can be reduced and the cost can be reduced.
Further, since only the hand is moved up and down, the rigidity of the entire hand device is increased, and vibration during operation can be reduced.
In addition, since the vertical movement mechanism can change the tilt angle of the gripping surface of the workpiece with respect to the horizontal plane, the hand can be leveled, so that the hand can be inserted into a narrower range and removed without interfering with the surroundings. Can do. For this reason, the cassette pitch on which the workpiece is placed can be narrowed, and the equipment can be made compact. Further, even if the equipment is not compact, it is possible to load a large number of workpieces in the same size cassette, and the productivity can be improved.

According to the second aspect of the present invention, the rotation shaft that is fixed to the bracket so as to be rotatable about the shaft is rotated by the driving means, thereby being eccentrically supported at a position eccentric with respect to the axis of the rotation shaft. The shaft also rotates as the rotating shaft rotates. The rotational drive of the eccentric shaft is transmitted to the hand through the link, and one end of the hand moves up and down.
Thus, the hand can be moved up and down with a simple transmission mechanism.

  According to the invention described in claim 3, high responsiveness can be realized by using a servo motor as the driving means.

  According to the fourth aspect of the present invention, since the amount of rotation angle correction can be changed for each hand having a different deflection state depending on the load state and structure, fine adjustment for improving the level is performed. be able to.

According to the fifth aspect of the present invention, the rotation angle of the rotation shaft is detected by the detection means, and the control means detects the workpiece to the hand when the rotation angle of the rotation shaft detected by the detection means is detected. Control is performed to rotate the rotating shaft by the driving means so that the rotation angle corresponding to the work loading condition and the hand operating condition on the hand stored in the storage means coincident with the loading condition and the hand operating condition.
As a result, the rotating shaft can be rotated in accordance with the load state of the work on the hand and the operation state of the hand, so that the work load surface of the hand can be easily leveled.

According to the invention described in claim 6, in the detection step, the rotation angle of the rotation shaft is detected by the detection means. In the control process, the rotation angle of the rotary shaft detected in the detection process matches the workpiece to the hand stored in the storage means that matches the loading status of the workpiece on the hand and the operation status of the hand at the time of the detection. Control is performed to rotate the rotating shaft by the driving means so as to obtain a rotation angle corresponding to the loading state and the hand movement state.
As a result, the rotating shaft can be rotated in accordance with the load state of the work on the hand and the operation state of the hand, so that the work load surface of the hand can be easily leveled.

Hereinafter, the best mode of a posture control method for a robot, a robot system, and a hand device will be described in detail with reference to the drawings.
<Robot and robot system configuration>
FIG. 1 is a diagram showing an outline of the robot system 100.
The robot system 100 is used when producing a liquid crystal display panel or a plasma display panel used for a large-sized thin television or the like. The production of display panels is performed in the clean room 1 in order to avoid product quality defects due to the adhesion of dust. In order to transport these display panels and their materials in the production process, a robot is installed in the clean room 1. 2 is arranged. The robot 2 takes out the glass substrates 12 stored in the cassettes 11 stacked in multiple stages and supplies the glass substrates 12 to the process apparatus, and stores the glass substrates 12 that have been processed in the process steps in the cassette 11. It is used for applications such as conveying between conveyors with differences.

The robot system 100 includes a robot 2 used in the clean room 1 and a control device 4 that controls the operation of the robot 2.
(Clean room)
The clean room 1 has an environment in which contact with the outside air is blocked by the partition 1a, and laminar clean air is supplied from one or more air supply devices 13 provided on the ceiling toward the floor surface. Yes. The air supply device 13 is a general-purpose fan filter unit that passes air sucked from outside through a filter to remove dust and the like, and sends clean air that satisfies a predetermined standard from above to below in the clean room 1. I care.
On the floor surface of the clean room 1, there is provided a dust storage unit 14 that draws the dust generated in the clean room 1 and discharges it to the outside of the clean room 1. Above the dust storage unit 14, a dust storage unit is provided. A grating 15 that guides the dust to the dust storage unit 14 is provided.

A plurality of cassettes 11 are stacked in multiple stages on the floor surface of the clean room 1, and each cassette 11 stores a glass substrate 12 as a work used for production of a display panel.
In the clean room 1, a conveyor device 16 is provided at a position facing the cassette 11 with the robot 2 interposed therebetween. The conveyor apparatus 16 conveys the glass substrate 12 taken out from the cassette 11 by the robot 2 to the process apparatus. The conveyor device 16 may play a role of transporting the glass substrate 12 that has been processed in the process step toward the robot 2 in order to store the glass substrate 12 in the cassette 11.
Note that the cassette 11 and the conveyor device 16 are disposed within the operation range of the robot 2.

(robot)
The robot 2 is fixed to the floor of the clean room 1.
The robot 2 includes a base frame 21 fixed to the floor, and one end of an upper and lower arm 22 is connected to the base frame 21. One end of the upper and lower arms 22 is rotatably connected to the base frame 21, and the upper and lower arms 22 are rotated about one end by a vertical movement motor 23 provided on the base frame 21, and the other end is an arc-shaped locus. Works to draw.
One end of an upper and lower arm 24 is connected to the other end of the upper and lower arm 22. One end of the upper and lower arms 24 is rotatably connected to the other end of the upper and lower arms 22, and the upper and lower arms 24 are rotated about one end by a vertical movement motor 25 provided at the other end of the upper and lower arms 22. The other end operates so as to draw an arc-shaped trajectory.

At the other end of the upper and lower arms 24, a turning base 26 is provided so as to be rotatable with respect to the upper and lower arms 24. The turning base 26 can maintain its posture in a constant state by the operation of the link 27 and the link 28.
A turning frame 29 is provided on the turning base 26 so as to be rotatable with respect to the turning base 26. The turning frame 29 is turned on the turning base 26 by a turning motor 30 provided on the turning base 26. It has become.
One end of a horizontal arm 31 is provided on the upper surface of the revolving frame 29 so as to be rotatable. At the other end of the horizontal arm 31, one end of a horizontal arm 32 is pivotably provided on the upper surface of the horizontal arm 31. At the other end of the horizontal arm 32, a wrist frame 33 is pivotably provided on the upper surface of the horizontal arm 32.
The horizontal arms 31 and 32 and the wrist frame 33 are configured to be interlocked by a horizontal movement motor 34 provided on the upper surface of the horizontal frame 31.
The wrist frame 33 is moved in the vertical direction and the horizontal direction by the operations of the upper and lower arms 22 and 24 and the horizontal arms 31 and 32 to hold the glass substrate 12 stored in the cassette 11 and convey it to the conveyor device 16. A hand device 5 is provided.

(Hand device)
FIG. 2 is a perspective view showing the appearance of the hand device 5.
As shown in FIG. 2, the hand device 5 includes a plurality of forks 51, 52 as hands that hold the glass substrate 12 from below, and one end of the forks 51, 52 moved up and down, and the glass in the forks 51, 52 is moved. And a vertical movement mechanism 53 that changes an inclination angle of the holding surface of the substrate 12 with respect to the horizontal plane.
(fork)
The forks 51 and 52 are formed in a thin plate shape extending in a substantially horizontal direction, and a plurality of suction pads 51a and 52a are provided on the upper surfaces of the forks 51 and 52 at predetermined intervals. That is, the hand device 5 moves so as to scoop up from the lower surface side of the glass substrate 12 accommodated in the cassette 11, and holds the glass substrate 12 by adsorbing the glass substrate 12 with vacuum pads 51a, 52a. Be able to.

(Vertical movement mechanism)
The vertical movement mechanism 53 includes a bracket 54 having one end connected to the wrist frame 33. The bracket 54 is a long plate-like member. A fork 51 is rotatably fixed to the upper surface of the bracket 54 via a bearing 55 and a shaft 56, and the fork 51 is connected to the fork 51 via a bearing 57 and a shaft 58. 52 is rotatably fixed.
The forks 51 and 52 are fixed so that the longitudinal direction thereof is orthogonal to the longitudinal direction of the bracket 54, and are rotatably fixed to the bracket 54 in the vicinity of one end of the forks 51 and 52. The fork 51 is fixed to the bracket 54 so that the fork 51 can be rotated with the shaft 56 as a rotation axis and the longitudinal direction of the fork 51 as a rotation radius. The fork 52 is fixed to the bracket 54 so that the fork 52 can be rotated with the shaft 58 as a rotation shaft and the longitudinal direction of the fork 52 as a rotation radius.

On the side surface of the bracket 54, bearings 59, 60 are provided in the vicinity of both ends of the bracket 54, and a rotary shaft 61 is pivotally supported by the bearings 59, 60 so as to be rotatable around the axis. The rotary shaft 61 is arranged such that its axis is along the longitudinal direction of the bracket 54, and in the vicinity of the center in the longitudinal direction of the rotary shaft 61, hand tilt correction as a driving means for rotating the rotary shaft 61 about the axis is provided. A motor 62 is provided via a speed reducer 63. The hand tilt correction motor 62 has a built-in position detector as a detecting means for detecting the rotation angle of the rotation shaft 61 with respect to the initial position, and is connected to the hand tilt correction motor 62 by detecting the rotation angle of the rotation shaft 61. Is output to the control device 4. Here, as the hand inclination correction motor 62, a servo motor or the like is used.
In the vicinity of both ends of the rotating shaft 61, eccentric shafts 64 and 65 that are supported by the rotating shaft 61 are fixed at positions that are eccentric with respect to the axis of the rotating shaft 61. The eccentric shafts 64 and 65 are provided with links 66 and 67 for transmitting the drive of the eccentric shafts 64 and 65 to the forks 51 and 52, respectively.

One end of the link 66 is rotatably connected to one end of the fork 51 via a pin or the like, and an eccentric shaft 64 is inserted into the other end and is rotatably supported with respect to the eccentric shaft 64. ing. Here, the link 66 is connected so that one end of the fork 51 moves up and down by the rotation of the eccentric shaft 64.
One end of the link 67 is rotatably connected to one end of the fork 52 via a pin or the like, and an eccentric shaft 65 is inserted into the other end and is rotatably supported with respect to the eccentric shaft 65. ing. Here, the link 67 is connected such that one end of the fork 52 moves up and down by the rotation of the eccentric shaft 65.

(Fork movement by vertical movement mechanism)
Here, the operation of the forks 51 and 52 by the vertical movement mechanism 53 will be described.
When a driving force is applied to the rotating shaft 61 via the speed reducer 63 by the hand inclination correcting motor 62, the rotating shaft 61 rotates around the axis, and the eccentric shafts 64 and 65 fixed to the rotating shaft 61 also rotate. As the eccentric shafts 64 and 65 rotate, the other ends of the links 66 and 67 that are rotatably supported by the eccentric shafts 64 and 65 reciprocate in the vertical direction, so that one ends of the links 66 and 67 are connected. One end of the forks 51 and 52 is moved up and down. By moving one end of the forks 51 and 52 up and down, the forks 51 and 52 rotate about the shafts 56 and 58, and the inclination angle of the grip surface of the glass substrate 12 in the forks 51 and 52 with respect to the horizontal plane is changed.

(Control device)
As shown in FIG. 1, the control device 4 is connected to the robot 2 by a cable 40 and is provided outside the clean room 1. That is, the operator can carry the glass substrate 12 by the robot 2 by operating the control device 4 from outside the clean room 1 without entering the clean room 1.
FIG. 3 is a block diagram showing a configuration of the robot system 100 having the control device 4.
The control device 4 includes a CPU 41 that executes each process in accordance with a process program related to operation control of the robot 2, and a memory 42 that stores a process program, process data, and the like for executing each process.
The memory 42 includes a program area 43 in which a program necessary for controlling the operation of the robot 2 is stored, a data area 44 in which data necessary for performing the operation control of the robot 2 is stored, various work memories, A counter and the like are provided, and a work area 45 in which each process is performed is formed.

  In the program area 43, the rotation angle of the rotating shaft 61 detected by the position detector coincides with the loading state of the glass substrate 12 on the forks 51 and 52 and the operation state of the forks 51 and 52 when the position is detected. The hand inclination correction motor 62 is adjusted so that the rotation angle corresponds to the loading state of the glass substrate 12 on the forks 51 and 52 and the operation state of the forks 51 and 52 in the rotation angle data 44d (described later) stored in the data area 44. The control program 43p for realizing the function of performing the control for rotating the rotary shaft 61 is stored. That is, when the CPU 41 executes the control program 43p, the control device 4 functions as a control unit.

In the data area 44, the rotating shaft 61 when the holding surface of the glass substrate 12 on the forks 51, 52 is made to coincide with the horizontal plane for each loading state of the glass substrate 12 on the forks 51, 52 and the operating state of the forks 51, 52. The rotation angle data 44d in which the rotation angle from the initial position is associated is stored. Therefore, the data area 44 functions as a storage unit.
Specifically, the rotation angle data 44d indicates whether or not the glass substrate 12 is loaded on the forks 51 and 52, the size and weight of the glass substrate 12 placed on the forks 51 and 52, and the operation position of the robot 2 ( The angle of the upper and lower arms 22, 24, the angle of the horizontal arms 31, 32, the moment acting on the tips of the forks 51, 52), the movement direction of the robot 2 (the direction of movement of the tips of the forks 51, 52 in the vertical direction or horizontal direction) ), The operating speed of the robot 2 (the operating speed of the upper and lower arms 22 and 24, the operating speed of the horizontal arms 31 and 32), and the like. It is associated with the necessary rotation angle as to whether it becomes horizontal.
In addition, the control device 4 is connected to the vertical movement motors 23 and 25, the turning motor 30, and the horizontal movement motor 34, all of which are controlled by the control device 4. The control device 4 controls ON / OFF of suction to the glass substrate 12 of the suction pads 51a and 52a of the hand device 5.

FIG. 4 is a block diagram illustrating functions of the robot system 100.
The robot system 100 includes a vertical movement unit 71 that moves the hand device 5 provided in the robot 2 in the vertical direction. The vertical movement units 71 and 25 and the vertical movement motors 23 and 25 perform the function of the vertical movement unit 71. .
The robot system 100 includes a turning unit 72 that turns the hand device 5 provided in the robot 2, and the turning frame 29 and the turning motor 30 take on the function of the turning unit 72.
The robot system 100 includes a horizontal moving unit 73 that moves the hand device 5 provided in the robot 2 in the horizontal direction, and the functions of the horizontal moving unit 73 are handled by the horizontal arms 31 and 32 and the horizontal moving motor 34.

The robot system 100 includes a holding unit 74 that holds the glass substrate 12 when the glass substrate 12 is transported, and the hand device 5 assumes the function of the holding unit 74.
The robot system 100 controls the operation of each of the above parts, and in particular, the loading state of the glass substrate 12 on the forks 51 and 52 and the fork when the rotation angle of the rotation shaft 61 detected by the position detector is detected. The rotation angle corresponding to the loading state of the glass substrate 12 on the forks 51 and 52 and the operation state of the forks 51 and 52 in the rotation angle data 44d (described later) stored in the data area 44 corresponding to the operation state of 51 and 52. The control unit 4 that realizes the function of performing the control of rotating the rotary shaft 61 by the hand inclination correction motor 62 is performed by the control device 4 that is a control unit.
The robot system 100 includes an inclination correction unit 76 that corrects the inclinations of the forks 51 and 52, and the hand inclination correction motor 62 and the control device 4 perform the function of the inclination correction unit 76.

<Deflection correction method>
(Deflection correction when a glass substrate is placed on a fork)
As shown in FIG. 5, when the glass substrate 12 is placed on the forks 51, 52, the glass substrate 12 moves toward the tip of the forks 51, 52 while the entire hand device 5 is displaced vertically downward by the load of the glass substrate 12. With a load of 12, it bends more downward.
In such a case, with respect to the vertical downward displacement of the entire hand device 5, the control device 4 measures the amount of deflection of the hand device 5 with a measuring device or the like previously installed outside, and based on this measured value. Then, the drive of the vertical movement motors 23 and 25 is controlled so as to raise the hand device 5 by the detected amount of deflection.

Further, the downward deflection of the tips of the forks 51 and 52 is placed on the forks 51 and 52 based on the rotation angle data 44d stored in the data area 44 when the control device 4 executes the control program 43p. The rotation of the rotating shaft 61 is controlled by controlling the driving of the hand tilt correction motor 62 so that the gripping surface of the glass substrate 12 is horizontal, and the forks 51, 52 are moved so that the tips of the forks 51, 52 move upward. Rotate.
By these two correction methods, the deflection when the glass substrate 12 is placed on the forks 51 and 52 can be corrected.

(Correction of deflection due to movement of fork)
As shown in FIG. 6, when the forks 51 and 52 are advanced, the forks 51 and 52 are displaced downward in the vertical direction as they move forward, and bend downward as they approach the tips of the forks 51 and 52.
In such a case, the downward deflection of the tips of the forks 51, 52 is caused by the control device 4 executing the control program 43p, so that the forks 51, 52 are based on the rotation angle data 44d stored in the data area 44. The rotation of the rotating shaft 61 is controlled by controlling the driving of the hand tilt correction motor 62 so that the grip surface of the glass substrate 12 placed on the fork is horizontal, and the forks 51 and 52 are moved upward so that the forks 51 and 52 move upward. 51 and 52 are rotated.

Here, as shown in FIG. 7, a mechanism for horizontally correcting the grip surface of the glass substrate 12 in the fork 51 will be described. The state in which the glass substrate 12 is not placed on the fork 51 is shown in FIG. ). At this time, the eccentric shaft 64 is in a state in which the rotation shaft 61 is positioned below.
As shown in FIG. 7B, when the glass substrate 12 is placed on the fork 51, the fork 51 bends due to the weight of the glass substrate 12, and the eccentric shaft 64 rotates so as to correct this deflection. When the eccentric shaft 64 is rotated, the rotation shaft 61 is rotated upward. As a result, the positions of the upper ends of the link and 66 are lowered, and the fork 51 has its proximal end connected to the link 66 lowered with 56 as a fulcrum, and the distal end moves upward. By this action, the deflection of the fork 51 can be corrected and the holding surface of the glass substrate 12 in the fork 51 can be made horizontal.

  Further, as shown in FIG. 7C, when the hand device 5 moves forward, the tip of the fork 51 bends downward. Even in this case, the eccentric shaft 64 rotates so as to correct this deflection. When the eccentric shaft 64 is rotated, the rotation shaft 61 is rotated upward. As a result, the positions of the upper ends of the link and 66 are lowered, and the fork 51 has its proximal end connected to the link 66 lowered with 56 as a fulcrum, and the distal end moves upward. By this action, the deflection of the fork 51 can be corrected and the holding surface of the glass substrate 12 in the fork 51 can be made horizontal.

Each of the corrections described above corrects the deflection of the forks 51 and 52. For example, as shown in FIG. 2, the bracket 54 is also a piece having one end attached to the revolving frame 29. Due to the weight of the glass substrate 12, the fork 51 and the fork 52 have different amounts of deflection because the tip of the bracket 54 bends more than the base end.
Even in such a case, the amount of eccentricity of the eccentric shaft 64 that drives the fork 51 is made larger than the amount of eccentricity of the eccentric shaft 65 that drives the fork 52, and the deflection is achieved by the drive control of the hand inclination correction motor 62 by the control device 4. The larger fork 51 may be rotated more than the fork 52.

<Effect>
According to the above-described embodiment, one end of each fork 51, 52 is moved up and down by the vertical movement mechanism 53, and the inclination angle of the grip surface of the glass substrate 12 in the fork 51, 52 with respect to the horizontal plane can be changed.
As a result, a motor having a small driving force can be adopted as a driving source for correcting the deflection / tilt of each fork 51, 52, and the weight of each fork 51, 52 can be reduced and the cost can be reduced.
Further, since only the forks 51 and 52 are moved up and down, the rigidity of the entire hand device 5 is increased, and vibration during operation can be reduced.
Further, the vertical movement mechanism 53 can change the inclination angle of the gripping surface of the glass substrate 12 in the forks 51, 52 with respect to the horizontal plane so that the forks 51, 52 can be leveled. 52 can be inserted and the glass substrate 12 can be taken out without interfering with the surroundings. For this reason, the pitch of the cassette on which the glass substrate 12 is placed can be reduced, and the equipment can be made compact. In addition, a large number of glass substrates 12 can be loaded on the same size cassette without downsizing the equipment, and productivity can be improved.
In addition, since the amount of correction can be changed for each of the forks 51 and 52 having different deflection states depending on the load state of the glass substrate 12 and the attachment positions of the forks 51 and 52, etc., the amount of correction can be improved. Adjustments can be made.

<Others>
The present invention is not limited to the above embodiment. For example, as shown in FIG. 8, an air cylinder 8 may be used in place of the servo motor used as the hand tilt correction motor 62. In the robot 20 shown in FIG. 8, when the air cylinder 8 is used, a support member 103 that supports the air cylinder 8 by the hinge 102 is provided on the bracket 101, and the air cylinder 8 is supported by the support member 103. Then, a knuckle 104 is attached to the tip of the piston rod 8 a of the air cylinder 8, and this knuckle 104 is connected to one end of the crank 105. The other end of the crank 105 is fixed to the rotating shaft 106, and one end of the crank 105 is pushed by the air cylinder 8, whereby the crank 105 rotates with the other end of the crank 105 as a fulcrum, so the rotating shaft 106 also rotates and rotates. The eccentric shafts 107 and 108 fixed to the shaft 106 rotate to move the links 109 and 110 up and down, and as a result, move one end of the forks 111 and 112 up and down.
Thus, by changing the amount of movement of the piston rod 8a of the air cylinder 8 according to the angle at which the forks 111, 112 are rotated, the forks 111, 112 can be moved up and down according to the amount of deflection, and a servo motor is used. Cost can be reduced as compared with the case of doing so.
Further, the present invention is not limited to a robot with two forks, but can be applied to a robot with three or more.
In addition, substitution and change are possible freely within the scope of the invention.

The figure which shows the outline | summary of a robot system. The perspective view which shows the structure of a robot. The block diagram which shows the structure of a robot system. The block diagram which shows the function of a robot system. The figure which shows the state which the fork bent below by the weight of the glass substrate. The figure which shows the state which the fork bent by the fork moving forward. (A) is a hand device without a glass substrate placed on the fork, (b) is a hand device with a glass substrate placed on the fork, and (c) is a glass substrate placed on the fork. Hand device when the fork is advanced. The perspective view which shows the robot in other embodiment.

Explanation of symbols

2 Robot 4 Control device (control means)
5 Hand device 12 Glass substrate (workpiece)
44 Data area (storage means)
51 fork (hand)
52 Fork (Hand)
53 Vertical movement mechanism 54 Bracket 61 Rotating shaft 62 Hand tilt correction motor (drive means)
64 Eccentric shaft 65 Eccentric shaft 66 Link 67 Link 100 Robot system

Claims (6)

In a robot including a hand device that moves in a vertical direction and a horizontal direction to grip a workpiece placed in a predetermined place and convey it to another place,
The hand device is
A plurality of hands holding the workpiece from below;
A vertical movement mechanism that moves up and down one end of each hand to change the inclination angle of the gripping surface of the workpiece in the hand with respect to the horizontal plane;
A robot characterized by comprising: The vertical movement mechanism is
A bracket on which the hand is rotatably fixed;
A rotating shaft fixed to the bracket so as to be rotatable about an axis;
Drive means for rotating the rotating shaft;
An eccentric shaft that is pivotally supported at a position eccentric with respect to the axis of the rotating shaft;
One end is rotatably connected to one end of the hand, the other end is rotatably supported by the eccentric shaft, and the link is connected so that one end of the hand moves up and down by the rotation of the eccentric shaft. ,
The robot according to claim 1, further comprising:   The robot according to claim 2, wherein the driving unit is a servo motor.   The eccentric amount of the eccentric shaft with respect to the rotation axis is set in association with a difference in deflection amount of each hand depending on a loading state of a work on the hand and an operation state of the robot. The robot described. The robot according to any one of claims 2 to 4,
Storage means for storing the rotation angle of the rotation axis in association with the horizontal surface of the workpiece gripping surface in the hand for each loading state of the workpiece on the hand and the operation state of the robot;
Detecting means for detecting a rotation angle of the rotation shaft;
The work to the hand stored in the storage means coincides with the loading state of the work on the hand or the operation state of the robot when the rotation angle of the rotating shaft detected by the detecting means is detected. Control means for performing control to rotate the rotating shaft by the driving means so as to have a rotation angle corresponding to the loading situation of the robot and the operating situation of the robot;
A robot system comprising: In the posture control method of the hand device for controlling the posture of the hand device by the robot system according to claim 5,
A detecting step of detecting a rotation angle of the rotating shaft by the detecting means;
The workpiece to the hand stored in the storage means coincident with the loading status of the workpiece on the hand or the operation status of the robot when the rotation angle of the rotating shaft detected by the detection step is detected. A control step of performing control to rotate the rotation shaft by the driving means so as to have a rotation angle corresponding to the loading state of the robot and the operation state of the robot;
A posture control method for a hand device, comprising:

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