JP2008254138A - Articulated robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an articulated robot which has a wide movable range and improves productivity by shortening a takt time. <P>SOLUTION: The articulated robot is equipped with an elevating part 2 composed of a link mechanism and a conveying part 1 which is mounted to the elevating part and conveys a workpiece. The elevating part 2 is composed of at least six arm bodies C1 to C7, and the arm bodies C1 to C7 rotate around respective joint axes J1 to J7. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an articulated robot that handles articles.

Conventional articulated robots have been proposed that reduce the turning radius of the articulated robot when the pedestal is rotated by offsetting the rotational center of the shoulder joint and the rotational center of the pedestal (for example, , See Patent Document 1).
1 to 3, a conventional articulated robot has a fixed base 10, a first main pillar 11 that is pivotally supported by a fixed base 10 with one end passing through a first axis S <b> 1. Is a second main column whose one end is traversed by a second axis S2 parallel to the first axis S1 and is pivotally supported by the other end of the first main column 11, and 13 is the second main column. An arm base 14 is provided in the other end of the shaft 12 so as to pass through a third shaft S3 parallel to the first shaft S1 and pivotally supported via a bearing 13a. The arm is composed of a first arm 14a and a second arm 14b, and is configured to rotate in the horizontal direction. Reference numeral 15 denotes a workpiece placed on the second arm 14b, and 16 is pivotally supported by the second main pillar 12 via a bearing 16a, which is passed through a fourth axis S4 coaxial with the second axis S2. One end of the link base 17 is pivotally supported on the fixed base and the other end is pivotable to one side of the link base 16 so as to form a parallelogram with the first main pillar 11. The first parallel link 18 that is pivotally supported has one end pivotally supported on the other side of the link base 16 and the other end that forms a parallelogram with the second main pillar 12. A second parallel link 19 that is pivotally supported by the shaft, 19 is a drive motor that is attached to the fixed base 10 and rotates the first main column 11 so that the rotation axis coincides with the first axis S1, and 20 is a drive. The motor 19 and the second main pillar 12 are connected to make the second main pillar 12 the first main pillar. 1 is that the coupling means for driving rotation in the opposite direction.
Patent No. 3403942 (2nd page, FIG. 1 and FIG. 2)

Articulated robots that take in and out thin-plate workpieces such as glass substrates for liquid crystals into and out of stockers are becoming larger, the number of substrates to be processed is increased, and processing is required in a short time, further increasing the yield of the substrates. Therefore, it is required to suppress dust generation from the robot as much as possible. For this reason, it is a major challenge for robots to achieve high speed, high accuracy, and low dust generation despite the fact that the equipment itself increases in size until the stocker on which the board is placed reaches the ceiling. ing. On the other hand, large-scale equipment requires a large amount of capital investment in order to keep the cleanliness of the surroundings clean. For this reason, it is desirable to arrange and process more substrates in the stocker. . In addition, handling robots that handle parts of automobiles are required to be able to realize movement from the upper part that accesses parts in the engine room and movement from the lower part that accesses parts such as bumpers with a single robot.
In addition, the articulated robot is not limited to a robot that handles thin plate-like workpieces such as glass substrates for liquid crystals, but an industrial robot that handles automobile parts is a device that has a small footprint and is placed in a factory. It is also desired to reduce the footprint so that there is no interference.
However, in the conventional articulated robot, when the arm is moved to the lowest point, the shape is such that the first main pillar and the second main pillar are folded as shown in FIG. Since it cannot be moved, there is a problem that the movable range is narrowed, and the height of the stocker for taking in and out the liquid crystal substrate is raised. Furthermore, when handling thin plate-like workpieces such as glass substrates for liquid crystals, the height of the stocker is limited to the height of the factory building, so the number of panels and substrates to be arranged is that of the vertical movement mechanism. There is a problem that the productivity is reduced because the movable range is narrowed. Further, when handling automobile parts, the bumper part of the lower part cannot be reached, so that there is a problem that new equipment such as lifting the vehicle body is required.
Moreover, when it is going to apply to the facility which enlarges, in order to reach | attain a high position about a height direction, it is necessary to lengthen a 1st main pillar and a 2nd main pillar. Then, a moment load acts on each joint shaft, and the driving motor is enlarged so as to generate a large torque. However, the motor driving the first main pillar is further enlarged. The problem arises that it is necessary and the footprint cannot be reduced. Further, if the size of the motor is increased, torque for operating at a high speed cannot be generated, resulting in a problem that the tact time is reduced. Furthermore, there has been a problem in that productivity is lowered due to a longer tact time.
The present invention has been made in view of such problems, and an object of the present invention is to provide an articulated robot having a wide movable range, a short tact time, and an improvement in productivity.

In order to solve the above problems, the present invention is configured as follows.
The invention according to claim 1 is an articulated robot including an elevating part constituted by a link mechanism and a conveying part that is attached to the elevating part and conveys a workpiece, wherein the elevating part has at least six arms. The arm body rotates around each joint axis.
In a second aspect of the present invention, a second joint axis is disposed between the first joint axis and the third joint axis of the arm body, and the second joint axis is the first joint axis. It is comprised so that it may orthogonally cross.
According to a third aspect of the present invention, the first joint shaft of the arm body is disposed so as to be rotatable with respect to the robot installation surface.
According to a fourth aspect of the present invention, a fifth joint axis is disposed between the fourth joint axis and the sixth joint axis of the arm body, and the fifth joint axis is the fourth joint axis. It is comprised so that it may orthogonally cross.
According to a fifth aspect of the present invention, the elevating part includes at least six arm bodies and at least six joint axes, and includes at least one joint axis perpendicular to the joint axis.
According to a sixth aspect of the present invention, the arm body includes seven joint shafts, and a second joint shaft orthogonal to the first joint shaft is provided between the first joint shaft and the third joint shaft. It is provided.
In a seventh aspect of the present invention, when the transport unit is moved to the lowest position by the lift unit, the lift unit is formed in parallel with the robot installation surface.
According to an eighth aspect of the present invention, when the transport unit is moved to the lowest position by the lifting unit, the arm body of the lifting unit is located between the first joint shaft and the third joint shaft. The second joint axis orthogonal to the first joint axis and the fifth joint axis orthogonal to the fourth joint axis rotate between the fourth joint axis and the sixth joint axis. Is formed parallel to the robot installation surface.
In a ninth aspect of the present invention, when the transport unit is moved to the lowest position by the lift unit, the lift unit is formed in a substantially U shape by the arm body.
In a tenth aspect of the present invention, when the transport unit is moved to the lowest position by the elevating unit, the joint shaft of the elevating unit is arranged so that the load center of gravity is located inside the joint shaft. Is.
According to an eleventh aspect of the present invention, the transport unit is a horizontal articulated arm.

According to the invention described in claims 1 to 6, since the load on each arm body can be reduced by having six or more joint shafts, it is possible to drive at high speed even using a small drive source. The tact time is not reduced. Furthermore, it can handle even larger equipment by extending the arm body little by little between each joint axis, so that a large load moment does not occur and it can be handled while maintaining high-speed driving in the height direction. Is possible.
According to the seventh to tenth aspects of the invention, the second joint shaft and the fifth joint shaft are rotated to form the elevating part in parallel with the installation surface, so that the accelerator region to the lowest position can be expanded. And the movable range can be expanded. Further, by positioning the load center of gravity in each arm body, the load moment to each joint axis can be reduced, high speed driving is possible, and productivity can be improved.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings, taking a transfer robot as an example.

FIG. 1 is a side view of a transfer robot according to the present invention. The horizontal conveyance unit 1 and the lifting unit 2 are configured separately.
In the elevating part 2, C1 is a first arm body, C2 is a second arm body, C3 is a third arm body, C4 is a fourth arm body, and C5 is a fifth arm body. This is an arm body, and C6 is a sixth arm body. The first arm C1 rotates about the joint axis J1, the second arm C2 rotates about the joint axis J2, the third arm C3 rotates about the joint axis J3, and the fourth arm C4 Rotates about the joint axis J4, the fifth arm C5 rotates about the joint axis J5, the sixth arm C6 rotates about the joint axis J6, and the seventh arm C7 rotates the joint axis J7. Rotate to center. The seventh arm C7 constitutes the base of the horizontal transport unit 1.
In the elevating unit 2, the joint axis J1 is orthogonal to the robot installation surface, the joint axis J2 is orthogonal to the joint axis J1, and the rotational axis is orthogonal to the joint axis J2. The joint axis J4 is orthogonal to the joint axis J3, the rotational axis is orthogonal to the joint axis J4, the rotational axis is orthogonal to the joint axis J5, and the rotational axis is orthogonal to the joint axis J5. The joint axis J7 is configured such that the respective rotation centers are orthogonal to the joint axis J6.

  The horizontal transport unit 1 includes an arm mechanism unit 4 configured by a horizontal link and performing a horizontal operation. In this embodiment, the horizontal transport unit 1 includes two arm mechanism units 4 in two upper and lower stages. In this embodiment, a turning drive unit is configured in the base unit of the horizontal conveyance unit 1. In applying the present invention, the arm is required to have at least one arm, but the turning drive unit may not be provided.

  The transport posture in FIG. 2 is the lowest transport posture of the elevating unit 2. When transporting the liquid crystal substrate, since the transport robot transports the glass substrate between the cassettes, it is required to transport the glass substrate at a low height at the bottom of the cassette due to restrictions on the size of the apparatus. Therefore, also in the robot, it is important that the horizontal conveyance unit 1 is installed as low as possible so that the pass line from the floor surface of the cassette apparatus is low and the posture 3 is low. In this embodiment, a bending shaft joint axis J2 is disposed between the joint axis J1 and the joint axis J3, so that the lifting unit 2 is positioned horizontally on the installation surface in the case of the horizontal transfer unit 1 minimum posture 3. Therefore, conveyance with a low pass line is possible.

  The conveying posture in FIG. 1 is the uppermost conveying posture of the elevating unit 2. In the liquid crystal manufacturing process, a glass substrate between processes is conveyed by a cassette, and therefore a tall cassette is used to store a large number of glass substrates in the cassette in terms of manufacturing efficiency. Therefore, it is important for the robot to be able to take a posture 4 that can be transported at a high position from the floor surface of the cassette apparatus. In the present embodiment, the second axis of the bending axis is disposed between the joint axis J1 and the joint axis J3, so that the elevating unit 2 is placed in a posture perpendicular to the installation surface in the case of the horizontal transfer unit 1 having the maximum upper limit posture. Therefore, it is possible to carry a long stroke even with a low pass line.

  Moreover, when the conveyance posture at the lowest limit shown in FIGS. 2 and 3 is taken, it is desirable that there is no drive source above the conveyance surface. In the manufacturing process, the inside of the clean room is down-flowed to prevent adhesion of particles to the glass substrate. If there is no drive source above the transfer surface, there is no problem, but if there is a drive source above the transfer surface, particle adhesion prevention measures have been installed in conventional transfer devices, so there are many cases where the structure is complicated. It was. In the present embodiment, since the elevating unit 2 is below the horizontal transport unit 1, no complicated measures for preventing particle adhesion are required, so that a simple transport device can be provided.

  The joint axes J1 to J4 that produce the vertical movement in the lifting / lowering unit 2 are basically based on the fact that the rotation center of the shaft is horizontal or vertical with respect to the robot installation surface in the transport posture 3, but even if they are inclined. good. In the embodiment, the joint axis J1 is installed inclined with respect to the robot installation surface. Compared with the case where it is installed horizontally, the normal distance from the axis of the joint axis J1 rotation center to the load is reduced, so the load inertia acting on the joint axis J1 is reduced. Further, the load torque acting on the joint axis J1 is reduced as compared with the case where the robot is installed horizontally with respect to the robot installation surface. Therefore, the drive motor and the speed reduction mechanism can be reduced in size and weight.

  In the top view in the transport position at the lowest limit posture of the elevating unit 2 shown in FIG. 3, the load gravity center position G is located inside the rotation center of the joint axis J1, the joint axis J3, the joint axis J4, and the joint axis J6 projected on the robot installation surface. Therefore, the joint axis J1 to the joint axis J4 that create the vertical movement can be arranged at positions close to the load gravity center position G. Therefore, since the moment arm length can be shortened, the load torque and load inertia acting on each joint shaft are reduced, and the drive motor and the speed reduction mechanism can be reduced in size and weight. In particular, in the transport posture of the lowest limit posture, only the load moments of the joint shaft J3, the joint shaft J4, and the joint shaft J6 act and the load torque does not act, and the current supplied to the drive motor can be reduced. Further, by increasing the joints, the load gravity center position G can be arranged at a position close to each joint, and the drive motor and the speed reduction mechanism portion of each joint can be reduced in size and weight.

  In the transfer posture of the maximum upper limit posture shown in FIG. 1, since the three-dimensional posture is constructed by the four axes of the joint axis J1, the joint axis J2, the joint axis J3, and the joint axis J4, the vertical position is not changed. The posture can be changed. Normally, when using a reducer, the rotational spring constant in the torque direction and the bending spring constant in the moment direction have a higher spring constant in the moment direction. It is possible to stabilize the work by changing the posture in the direction in which the moment acts. Therefore, it is not necessary to employ a speed reducer having a large rotational spring constant, and the speed reduction mechanism portion can be reduced in size and weight.

  In addition, when the stroke is not long and the load is not large in the joint axis J1, the joint axis J2, the joint axis J3, and the joint axis J4 that generate the vertical movement in the elevating unit 2, the simple transportation can be achieved by omitting the joint axis J3. A device can be constructed.

  The lifting / lowering unit 2 according to the present invention can be applied to a liquid crystal transfer robot together with the horizontal transfer unit 1. However, if the lifting / lowering unit 2 is used, it can be used as a heavy material transfer device. As an example, since the elevating unit 2 can be configured with a low posture, it is also suitable for inter-process conveyance of an automobile body that conveys while suppressing the height of equipment. This can be applied by setting and clamping the automobile body instead of the horizontal conveyance unit 1.

The side view of the conveyance robot which shows 1st Example of this invention The side view of the conveyance robot which shows 1st Example of this invention 1 is a top view of a transfer robot showing a first embodiment of the present invention. Side view of a conventional transfer robot Side view of a conventional transfer robot

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Horizontal conveyance part 2 Lifting part 3 Robot installation surface 4 Arm mechanism part G Load gravity center-of-gravity position C1 1st arm body C2 2nd arm body C3 3rd arm body C4 4th arm body C5 5th arm body C6 Sixth arm body C7 Seventh arm body J1 Joint axis J2 Joint axis J3 Joint axis J4 Joint axis J5 Joint axis J6 Joint axis J7 Joint axis

Claims (11)

In an articulated robot comprising an elevating part constituted by a link mechanism, and a conveying part attached to the elevating part and conveying a workpiece,
The elevating part is composed of at least six arm bodies, and the arm bodies rotate around respective joint axes.   A second joint axis is disposed between the first joint axis and the third joint axis of the arm body, and the second joint axis is configured to be orthogonal to the first joint axis. The articulated robot according to claim 1.   The articulated robot according to claim 1, wherein the first joint axis of the arm body is disposed so as to be rotatable with respect to the robot installation surface.   A fifth joint axis is disposed between the fourth joint axis and the sixth joint axis of the arm body, and the fifth joint axis is configured to be orthogonal to the fourth joint axis. The articulated robot according to claim 1.   The articulated robot according to claim 1, wherein the elevating unit includes at least six arm bodies and at least six joint axes, and includes at least one joint axis orthogonal to the joint axis.   The arm body includes seven joint axes, and includes a second joint axis perpendicular to the first joint axis between the first joint axis and the third joint axis. The articulated robot according to 1.   The articulated robot according to claim 1, wherein when the transport unit is moved to the lowest position by the elevating unit, the elevating unit is formed in parallel with the robot installation surface.   When the transport unit is moved to the lowest position by the elevating unit, the arm body of the elevating unit is a first orthogonal to the first joint axis between the first joint axis and the third joint axis. A second joint axis and a fifth joint axis orthogonal to the fourth joint axis between the fourth joint axis and the sixth joint axis are formed in parallel with the robot installation surface by rotating. The articulated robot according to claim 7, wherein:   2. The articulated robot according to claim 1, wherein when the transport unit is moved to the lowest position by the elevating unit, the elevating unit is formed in a substantially U shape by the arm body.   The joint shaft of the lifting part is arranged so that a load center of gravity is located inside the joint axis when the transport part is moved to the lowest position by the lifting part. The articulated robot described.   The articulated robot according to claim 1, wherein the transport unit is a horizontal articulated arm.

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