JPH0557665A - Transfer robot - Google Patents

Abstract

PURPOSE:To accommodate a fluid passage, required for action, inside a robot by leading the passage of a fluid for driving a grip means, into a first arm from the inside of a base through a second opening hole, and further leading this fluid passage into a second arm through the sixth hole part formed at a second rotary shaft. CONSTITUTION:An air pipe 72 is piped through inside a robot. An air pipe 70 extended from the floor surface or a frame in the first place enters a base 12 from its lower part and enters a first arm 28 from the upper part of the base 12. A hole part 14b surrounding a first speed reducer 24 is formed at a motor fixing base 14, and the air pipe 70 enters the first arm 28 through this hole part 14b. The air pipe 70 having entered the first arm 28 is connected to a joint member 36 and further connected to an air pipe 74 in a second arm 46 through air passages 36b, 36c, 42b, 42c formed inside the joint member 36 and the output shaft 42a of a second speed reducer 42 in this order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer robot for transferring wafers, reticles and the like.

[0002]

2. Description of the Related Art In a semiconductor or the like manufacturing apparatus, in order to take out a wafer, a reticle or the like stored in a cassette, or conversely, to store a wafer, a reticle or the like in a cassette, a transfer for grasping and transferring them Robots are being used. In such a transfer robot, a linear transfer operation is required to prevent damage to the wafer, reticle and the like. As a conventional example of such a transfer robot, there are JP-A-2-82550 and JP-A-2-831.
A device using a timing belt as disclosed in Japanese Patent Publication No. 82 is known. In addition, Japanese Patent Laid-Open No. 1-1407
It is known that a transfer robot mechanically moves linearly by using a link mechanism as disclosed in Japanese Patent Publication No. 38-38.

[0003]

However, the above-mentioned conventional transfer robot has a problem that the transmission mechanism is complicated and the cost is increased. In order to solve this problem, it is possible to simplify the mechanism by connecting separate rotation drive devices to each arm that constitutes the transfer robot and controlling these drive devices in association with each other by the control device. .. However, in this case, it is possible to use a structure in which a pulley is used as a hollow shaft and a pipe that carries the fluid required for robot operation is passed therethrough, which was possible when using a conventional pulley and timing belt. Can not be. Therefore, the pipe is forced to pass through the outside of the robot, and the robot used in the clean room has a problem in terms of dust generation. Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a transfer robot capable of accommodating therein a fluid passage required for robot operation.

[0004]

In order to solve the above-mentioned problems and to achieve the object, a transfer robot of the present invention comprises a cylindrical main body having at least one open end and the one end of the main body. The base, which is provided so as to be closed and has a first opening hole formed substantially in the center, and the lid,
A second opening hole that is formed so as to be located around the opening hole of the main body portion and allows at least the signal line to be led out from the inside of the main body portion; A first drive means having a first rotating shaft protruding to the outside of the stand as an output shaft, a third opening hole at one end, and a fourth opening hole at the protruding end at the other end. A first arm having a cylindrical protrusion formed on the first rotation shaft, the one end of the first arm being attached to the first rotation shaft in a state where one end of the main body is inserted into the third opening hole. A hollow first arm having a fixed portion, which is rotatable about the first rotation axis, and a first arm that is disposed inside the protrusion and that extends from the fourth opening hole. Drive means having a second rotating shaft projecting to the outside of the vehicle as an output shaft, and a fifth driving means in which the projecting end is inserted into one end. A second arm having an opening hole,
One end of the second arm is fixed to the second rotating shaft,
A second hollow member that is rotatable about the second rotation axis.
Arm, a third arm rotatably supported at the other end of the second arm, fluid-driven gripping means disposed on the third arm, and the base of the base. A sixth member that is brought from inside to the inside of the first arm through the second opening hole and that is formed on the second rotation shaft at least along the extending direction of the second rotation shaft. And a fluid passage which is introduced into the second arm through the hole and through which a fluid for driving the gripping means flows.

[0005]

Since the transfer robot according to the present invention is constructed as described above, it becomes possible to form a fluid passage through the second opening hole and the sixth hole portion, and the operation of the robot is performed. It is possible to provide a transfer robot in which a fluid passage necessary for the above is housed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. First, based on FIG. 1 which is a side sectional view of a robot of one embodiment, a robot 10
The configuration of will be described. In FIG. 1, a substantially cylindrical robot base 12 has a flange portion 1 at the lower end of the outer peripheral surface thereof.
2a, and the flange portion 12a is fixed to the floor surface of a factory or a pedestal arranged on the floor surface by bolts or the like, and is held on the floor surface or the pedestal. On the upper end surface of the robot base 12, a motor fixing board 14 is fixed by bolts 16 so that the upper end of the robot base 12 is sealed. The first arm drive device 18 is fixed to the lower surface of the central portion of the motor fixing board 14. The first arm drive device 18 includes a first arm 2 which will be described later.
A first motor 20 for generating a driving force for rotationally driving the motor 8, and a first motor 20 connected to a lower end of the first motor 20.
Fixed to the rotary encoder 22 of the first motor 20 and the reduction gear train inside the rotary motor 22 of the first motor 20.
The first reduction gear 24 is connected to the zero output shaft. The upper end surface of the first speed reducer 24 is fixed to the lower surface of the motor fixing board 14, and the first speed reducer 2
The output shaft 24a of No. 4 projects above the motor fixing board 14 through a hole 14a formed in the center of the motor fixing board 14.

On the other hand, a flange portion 12b is formed on the upper end portion of the outer peripheral surface of the robot base 12, and the rotation center axis of the flange portion 12b is formed further on the outer peripheral portion of the first reducer 24. The 1st bearing 26 is attached in the state where it matched with the axis of rotation. The outer ring 26a of the first bearing 26 has a first arm 28 extending horizontally.
Is a fitting portion 28a formed at one end of the first arm 28.
Is attached to the outer ring 26a.
That is, the first arm 28 is provided with respect to the robot base 12.
The first bearing 26 is rotatably supported in the horizontal plane around the rotation center axis of the first bearing 26, that is, around the output shaft 24a of the first speed reducer 24. In addition, the output shaft 24 of the first speed reducer 24
A first transmission lever 30 for transmitting the power of the first motor 20 to the first arm 28 is fixed to a, and the tip end portion of the first transmission lever 30 is a disc-shaped connection. Member 3
It is fixed to the first arm 28 via 2. Therefore, the first arm 28 is rotationally driven in the horizontal plane around the output shaft 24a of the first speed reducer 24 by the rotation of the first motor 20.

Next, a second arm driving device 34 having the same structure as the first arm driving device 18 is fixed to the other end of the first arm 28 via a joint member 36. Specifically, the first arm 28
A substantially cylindrical joint member 36 having a sealed upper end is attached to the upper surface of the other end of the joint member 36. A second motor 38 for driving a second arm 46, which will be described later, and a second rotary encoder 40 connected to the lower end of the second motor 38 are provided on the lower surface of the ceiling of the joint member 36. A second arm drive device 34 including a second speed reducer 42 connected to the upper portion of the second motor 38 is fixed. The output shaft 42 a of the second speed reducer 42, which constitutes the upper part of the second arm drive device 34, has a hole 36 formed in the ceiling of the joint member 36.
It projects above the joint member 36 via a.

On the other hand, in the upper part of the outer peripheral surface of the joint member 36,
The second bearing 44 is attached such that its rotation center axis is aligned with the output shaft 42a of the second speed reducer 42. A second arm 46 extending horizontally is attached to the outer ring 44a of the second bearing 44 with a fitting portion 46a formed at one end of the second arm 46 fitted to the outer ring 44a. Has been. That is, the second arm 46
Is rotatably supported by the first arm 28 around the rotation center axis of the second bearing 44, that is, the output shaft 42a of the second speed reducer 42. In addition, the second speed reducer 4
The second output shaft 42a includes a second arm 46 and a second motor 38.
The second transmission lever 48 for transmitting the power of the second transmission lever 48 is fixed, and the tip end portion 48a of the second transmission lever 48 is fixed.
Are fixed to the second arm 46 via a disc-shaped connecting member 49. Therefore, the second arm 46 is rotationally driven in the horizontal plane around the output shaft 42a of the second speed reducer 42 by the rotation of the second motor 38.

A small pulley 50 is fixed to the upper end surface of the joint member 36, and a large pulley 60 and a steel belt 62 fixed to a rotary shaft 56 of a third arm 54, which will be described later.
Are connected by. Next, the rotating shaft 56 of the third arm 54 is rotatably supported at the other end of the second arm 46 via the third bearing 52. One end of a third arm 54 extending along a direction perpendicular to the plane of the drawing is fixed to the upper end of the rotary shaft 56. That is, the third arm 54 is rotatably supported in the horizontal plane with respect to the second arm 46. A hand 58 (see FIG. 7) for holding a wafer, a reticle, etc. is attached to the other end of the third arm 54. The hand 58 sucks a wafer, a reticle, and the like by vacuum.

On the other hand, a large pulley 60 is fixed to the lower side of the rotary shaft 56 of the third arm 54, and the rotation of the large pulley 60 drives the third arm 54 to rotate with respect to the second arm 46. It Then, as described above, the steel belt 62 is stretched over the large pulley 60 and the small pulley 50 fixed to the joint member 36. Also, these small pulleys 50
An idler 64, which is rotatably supported by the second arm 46, is arranged substantially in the middle of the large pulley 60, and the slack of the steel belt 62 is removed. Here, the small pulley 50, the large pulley 60, and the steel belt 6 described above.
The rotation mechanism of the third arm composed of 2 and the idler 64 will be described in detail with reference to FIGS. 2 to 6.

First of all, the steel belt 62 among the above-mentioned components is made of a known stainless steel strip material. The steel belt 62 may be formed in a loop shape or may be open at both ends, but here, the open end is used. As shown in FIG. 2, the steel belt 62 having both ends opened has two holes 62a, 62b, and 62c at both ends and at one place near the center.

This steel belt 62 is used for the small pulley 5
0, the large pulley 60, and the idler 64 are stretched in the state as shown in FIG. Here, the steel belt 62 is a plate-shaped belt retainer 66,
It is fixed to each pulley by 67 and a set screw 68.
More specifically, on the small pulley 50 side, as shown in FIG. 4A, a hole 66a (see FIG. 5) formed in the belt retainer 66 and a hole formed substantially in the center of the steel belt 62. The set screw 68 is passed through the portion 62c, and in this state, the set screw 68 is screwed into the screw hole formed in the small pulley 50, so that the steel belt 62 is pressed down. Further, on the large pulley 60 side, as shown in FIG. 4B, in a state where both ends of the steel belt 62 are overlapped,
Hole 67a of belt retainer 67 and steel belt 62
The steel belt 62 is pressed down by passing the setscrews 68 through the hole portions 62a and 62b at both ends of the above and screwing the setscrews 68 into the screw holes formed in the large pulley 60.

Further, the shape of the belt retainers 66 and 67 will be further described. The belt retainers 66 and 67 are shown in FIG.
(A), as shown in FIG. 5 (b), each inner surface 66a,
67a has a shape along the outer shape of the small pulley 50 and the large pulley 60, respectively. This allows the steel belt 6
No. 2 is pressed by the surface, and stress concentration is less likely to occur as compared with the case of pressing only with the set screw 68, which is advantageous in strength. Further, the chamfered portion 6 having a round shape is provided at both ends of the inner surfaces 66b and 67b of the belt retainers 66 and 67, respectively.
6c and 67c are formed respectively. As a result, even if the respective pulleys are excessively rotated and the steel belt 62 is bent by the belt retainers 66 or 67 as shown in FIG. 6, the steel belt 62 is not damaged.

In the robot 10 of the embodiment, the axial distance cannot be changed due to its structure. Therefore, the idler 64 is arranged to remove the slack of the steel belt 62 as described above. 64 also has a function of increasing the rotatable angle of the third arm 54. That is, when the steel belt is wound around the respective pulleys as shown in FIG. 3B, the winding angle of the steel belt 62 becomes small, so that each pulley has a small rotation amount and two points in the figure. The steel belt 62 is bent as shown by the chain line. On the other hand, if the idler 64 is arranged as shown in FIG. 3A, the wrap angle of the steel belt 62 becomes large, and the third arm 54
The rotatable angle of can be increased.

Next, the robot 10 configured as described above.
The principle of the operation will be described with reference to FIGS. 7 to 9. The operation pattern of a robot that conveys wafers, reticles, and the like is usually two patterns, the linear movement shown in FIG. 7 and the rotational movement shown in FIG. First, regarding the case where the hand 58 moves from the initial position shown in FIG. 7A along a straight line h orthogonal to the reference straight line i as shown in FIGS. 7B and 7C. explain. Here, as a prerequisite, as shown in FIG. 7C, the arm length of the first arm 28 and the second arm 4 are
It is assumed that the arm lengths of 6 are equal and the lengths are both L. The rotation angles of the first arm 28, the second arm 46, and the third arm 54 are represented by θ1, θ2, and θ3, respectively. At this time, θ1, θ2, and θ3 hold the relationship represented by θ2 = 180 ° -2θ1 θ3 = θ2 / 2, where θ1 = 0 to 90 ° θ2 = 180 ° to 0 ° θ3 = 90 ° to 0 ° 1st arm to 3rd arm 2
When 8, 46, 54 are operated, the tip portion of the third arm 54, that is, the hand 58, moves linearly along the straight line h as shown in FIGS. 7 (a) to 7 (c).

In order to realize this, in the robot of one embodiment, two motors having the same characteristics are connected to the first motor 20.
And the second motor 38, and the first speed reducer 24
And the ratio of the speed reduction ratio of the second speed reducer 42 is 2: 1. Incidentally, in one embodiment, the speed reduction ratio of the first speed reducer 24 is 1/100, and the speed reduction ratio of the second speed reducer 42 is 1.
/ 50. That is, the first and second motors 20,
When 38 is rotated at the same rotation speed in the opposite direction,
When the first arm 28 rotates in the counterclockwise direction about the origin O by θ1 as shown in FIG. 7C, the second arm 46 moves to the first position.
2 around the point P1, which is the tip of the arm 28, in the clockwise direction.
It will rotate by θ1. As a result, the point P2 that is the rotation center of the third arm 54, that is, the rotation shaft 56, moves linearly along the straight line h.

As for the third arm 54, the small pulley 5
By setting the diameter of 0 to ½ of the diameter of the large pulley 60, the third arm 54 can be moved along the straight line h while satisfying the relationship of θ3 = θ2 / 2.
That is, the hand 58 can be moved along the straight line h. These relationships will be described in a more understandable manner based on FIG. First, from the position shown in FIG. 9A, which is the same initial state as in FIG.
It is assumed that the first arm 28 is rotated by θ in the counterclockwise direction by rotating only the first arm 28. After performing such an operation, the state of the robot 10 is as shown in FIG. 9 (b). From this state, by rotating only the second motor 38 and rotating the second arm 46 with respect to the first arm 28 in the clockwise direction by 2θ, the arm length of the first arm 28 and the second arm 46
Since the arm lengths of the arms 46 are the same, the point P2, which is the tip of the second arm 46, moves on the straight line h as shown in FIG. 9C. Therefore, as you can see from this, the second
In order to move the point P2, which is the tip of the arm 46, along the straight line h, the rotation direction of the second arm 46 is opposite to the rotation direction of the first arm 28, and the rotation angle of the second arm 46 is It may be set so that it is always twice the rotation angle of the first arm 28.
This means that the speed reduction ratio of the first speed reducer 24 and the speed reduction ratio of the second speed reducer 42 are 2: 1 as described above, and the first motor 20 and the second motor 38 rotate at exactly the same speed. At speed,
This means that the first arm 28 and the second arm 46 may be rotated so that the rotation directions thereof are opposite to each other.

Next, consider a case where the second arm 46 is rotated clockwise by 2θ from the state shown in FIG. 9B. At this time, assuming that the third arm 54 is fixed to the second arm 46, the third arm 54 is indicated by B in FIG. 9C after the second arm 46 rotates by 2θ. Have come to the position. That is, the third arm 54 is located at a position that has rotated too much clockwise in the clockwise direction from the position on the straight line h indicated by A, which is the target position. However, in reality, the third
Since the arm 54 is connected to the joint member 36 by the steel belt 62 that is stretched between the large pulley 60 and the small pulley 50, the third arm 54 is rotated by the clockwise rotation of the second arm 46. And rotates counterclockwise around the point P2. The rotation angle at this time is θ. This is because the second arm 46 rotates about the point P1 in the clockwise direction by 2θ, which means that the joint member 36 at the position of the point P1 is relative to the second arm 46 as indicated by the white arrow. It also means rotating in the counterclockwise direction by 2θ. Therefore, the third arm 54 connected to the joint member 36 via the small pulley 50, the large pulley 60 and the steel belt 62 multiplies the relative rotation angle 2θ of the joint member by the diameter ratio of the two pulleys 1/2. It is rotated in the counterclockwise direction by the angle θ. Thereby, the third arm 54
Moves to the position on the straight line h shown by A in the figure, and the hand 58 also moves accurately along the straight line h.

Although the hand 58 is moved along the straight line h as described above, a pulley may not be used to drive the rotation of the third arm 54. For example, the first arm 28
Similarly to the driving of the second arm 46 and the third arm 54, a rotation driving device is provided to rotate the third arm 54 in the same direction at the same rotation speed as the first arm 28. It is possible to operate in exactly the same way as when using a pulley. It is needless to say that only the first motor 20 needs to be rotated when the rotational movement as shown in FIG. 8 is performed.

Next, the piping of the air pipe to the hand 58 attached to the third arm 54 and the wiring to each motor will be described with reference to FIGS. 1 and 10. Since the robot 10 of one embodiment is normally used in a clean room, the air pipe 70 and the signal line 72 are not used in the robot 1.
Piping and wiring will be performed through the inside of 0. First, the air pipe 70 and the signal line 72 extending from the floor surface or the pedestal enter the base 12 from the lower portion of the base 12, and a part 72a of the signal line 72 is the first motor 20 and the first motor 20. It is connected to the rotary encoder 22. The remaining signal line 72b and the air pipe 70 pass through the inside of the base 12 and enter the inside of the first arm 28 from the upper portion of the base 12. Here, the connecting portion between the base 12 and the first arm 28 is configured as shown in FIG. On the motor fixing board 14 attached to the upper end of the base 12,
Crescent shaped hole 14b surrounding the first speed reducer 24
Are formed. Then, the air pipe 70 and the signal line 72b enter into the first arm 28 through the hole 14b. Signal line 72b that has entered the inside of the first arm 28
Is connected to the second motor 38 and the second rotary encoder 40.

On the other hand, the air pipe 70 that has entered the inside of the first arm 28 is connected to the joint member 36, and the air passages 36b, 36c formed in the joint member 36 and the output shaft 42a of the second reduction gear 42, 42b, 42c in order,
It is connected to the air pipe 74 in the second arm 46. Specifically, the joint member 36 has a tunnel-shaped air passage 36b extending upward from the lower surface of the joint member 36. The tip of the air passage 36b is connected to an air passage 36c extending from the side of the joint member 36 toward the center. The air passage 36c is connected to a center hole 36d formed in the center of the joint member 36b. The output shaft 42a of the second speed reducer 42 is provided in the center hole 36d.
Is inserted into the output shaft 42a.
Is formed with a hole 42b that opens to the side. The hole 42b is connected to a tunnel-shaped air passage 42c extending upward along the central axis of the output shaft 42a. Therefore, the air supplied from the air pipe 70 is
Air passages 36b, 36c, hole 42b, air passage 42c
Is sequentially guided to the air pipe 74 connected to the tip of the output shaft 42a. The central hole 3 of the joint member 36
Oil seals 75 are provided at the upper and lower ends of 6d to prevent air leakage from the output shaft 42a.

The air pipe 74 is connected to an air passage 60a passing through the inside of the second arm 46 and opening to the lower surface of the large pulley 60. Since the upper end of the air passage 60a is connected to the air passage 56a formed on the rotating shaft 56, the air supplied from the air pipe 74 is guided to the third arm 54 via the air passages 60a and 56a in sequence. Get burned. Since the robot 10 is used in the clean room as described above, the magnetic seal 7 is attached to each rotating portion.
6, 78, 80 are arranged, and O-rings 82, 84, 86 are attached to the respective fixing parts. Further, a seal member 88 for preventing air leakage is arranged at the opening of the air passage 36c to the side surface of the joint member 36.

Next, a control circuit for controlling the robot 10 will be described. The control unit 100 includes the CPU 10
2, memory 104, operation unit 106, first control circuit 11
2 and a second control circuit 114. Then, the first motor 20 is connected to the first control circuit 112, and the first control circuit 112 has the position data output from the first rotary encoder 22 and the first rotary encoder 22. The rotation of the first motor 20 is controlled based on the speed data output from the F / V converter (not shown). Similarly, the second motor 38
Is connected to the second control circuit 114,
Of the second rotary encoder 40.
The rotation of the second motor 38 is controlled based on the position data output from the second rotary encoder 40 and the speed data output from the second rotary encoder 40 via an F / V converter (not shown). When the third motor is used to drive the rotation of the third arm 54, a third control circuit having the same configuration as the first and second control circuits is used as shown by the broken line in the figure. It should be provided. The first and second motors 20, 38
The rotation control is performed by known numerical control.

Next, the control operation of the rotation angles of the first arm 28 and the second arm 46 of the robot 10 configured as described above will be described with reference to FIGS. 12 to 16. First, when the target object is rotated in a certain direction by a certain rotation angle in the shortest time, the pattern of change in angular velocity with respect to time is as shown in FIG. This pattern is
The target object is accelerated at a constant angular acceleration, and when the maximum angular velocity is reached, the target object is moved at this maximum angular velocity, then decelerated at the same angular acceleration as during acceleration, and stopped at the target position. Usually, the drive source for moving a certain target,
When the maximum angular acceleration and the maximum angular velocity that can be generated are limited, the movement time T2 and the start-up time T1 at the maximum angular velocity θ _vm in the pattern for moving the moving object in the shortest time are limited. The fall time T3 is determined. Also in the robot 10 of the embodiment, the angular velocity pattern as described above is used for the rotational movement of the first arm 28 and the second arm 46.

FIG. 1 shows an ideal value of the relationship between the time T and the rotation angle θ when moving in the angular velocity pattern as described above.
It is 3. With the point on the ideal curve as a target, the rotation angle θ is detected at every predetermined time interval ΔT, and the difference between the actual rotation angle and the target value is feedback-controlled, so that the moving object is moved only by the target rotation angle. It can be rotated. Here, as described above, in order to linearly move the hand 58, the first arm 28 is rotated, for example, by θ1 in the counterclockwise direction, and the second arm 46 is rotated in the clockwise direction with respect to the first arm 28. It is necessary to rotate θ2 = 2θ1 and rotate the third arm counterclockwise with respect to the second arm by θ3 = θ1. When the above control method is applied to this operation, the relationship between the rotational angular velocity θ _v and the time T and the relationship between the rotational angle θ and the time T at that time are as shown in FIGS. 14 and 15, respectively. As shown in FIG. 14, the rotational angular velocity θ1 _v of the first arm 28
And the rotation angular velocity θ2 _v of the second arm are always set to 1: 2, the rotation angle θ of the first arm 28 as shown in FIG.
The ratio of 1 to the rotation angle θ2 of the second arm 46 is always 1: 2. Further, the third arm 54 includes the small pulley 50 and the large pulley 6
Since the first arm 28 and the second arm 46 are driven so that the rotation angle θ1 of the first arm 28 and the rotation angle θ2 of the second arm 46 become 1: 2, the third arm 54 inevitably moves. Since the hand 58 is rotated in the same direction by the same rotation angle, the hand 58 is accurately moved linearly.

Next, the specific rotation operation of the first arm 28 and the second arm 46 will be described based on the flow chart shown in FIG. First, before activating the robot 10 according to this flowchart, the worker preliminarily calculates the rotation angles θ1 and θ2 of the first arm 28 and the second arm 46 and the rotation start-up time T1 from the coordinates of the target movement position of the hand 58. The fall time T3, the maximum rotational angular velocities θ1 _vm and θ2 _{vm of} the first arm 28 and the second arm 46, and the moving time T2 at these maximum rotational angular velocities are calculated. After this preliminary work, the operation of the flowchart is started.

First, in step S20, the operator operates the operating unit 106 to set the start-up time T1 in FIG.
And input the set value of the fall time T3. This value is stored in the memory 104. Next, in step S22, the operator determines the rotation angle θ1, between the first arm 28 and the second arm 46.
Input θ2 from the operation unit 106. This value is also stored in the memory 104. Similarly, in step S24, the operator inputs the maximum rotational angular velocities θ1 _vm and θ2 _vm of the first arm 28 and the second arm 46 from the operation unit 106. Then, these values are also stored in the memory 104. When these inputs are completed, the robot 10 moves the hand 58
Is in a standby state to move.

Next, in step 26, when the operator inputs a start signal from the operation unit 106, the CPU 102
Is the second arm 2 having a large rotation angle in step S28.
The target rotation angle θ2 ′ of the second motor 38 for driving 8 is calculated, and the process proceeds to step S30. In step S30, C
The PU 102 calculates the rotation angle Δθ2 of the second motor 38 per unit time ΔT (for example, per 5 msec). At the same time, the rotation angle Δ of the second motor 38
By multiplying θ2 by k, the rotation angle Δθ1 (Δθ1 = kΔθ2) of the first motor 20 per unit time is calculated. Here, k is the first motor 20 and the second motor 38.
Is the ratio of the rotation angle of. In one embodiment, the speed reduction ratio of the second speed reducer 42 is 1/2 the speed ratio of the first speed reducer 24.
By doing so, if the first and second motors 20 and 38 are rotated at exactly the same angular velocity, the hand 58 moves straight. Therefore, k = 1 here. However, the speed reduction ratio of the second speed reducer 42 is not necessarily the first
It is not necessary to reduce the speed reduction ratio of the speed reducer 24 to 1/2, and this can be dealt with by changing the value of k according to the speed reduction ratio of these speed reducers. For example, the first reducer 24
When the speed reduction ratio of 1 and the speed reduction ratio of the second speed reducer 42 are the same, k may be set to 1/2.

Next, in step S32, the CPU
The accelerations for rotating the first and second motors 20 and 38 by these rotation angles Δθ1 and Δθ2 within a unit time are calculated, and the accelerations of the first and second motors 2 and 2 are calculated.
Rotate 0,38. Then, the first and second motors 20 and 38 are rotated while detecting the rotation angle for each unit time ΔT by the first and second rotary encoders 22 and 40. Then, in step S34, it is determined whether or not the first and second motors 20, 38 have rotated up to the target rotation angle. If the target rotation angle has not been reached, step S34 is executed.
30 and step S32 are repeated. In step S34, the first and second motors 20 and 38 are set to the target rotation angle θ.
If it is determined that the values have reached 1 ', θ2', step S36.
To stop each motor and end the operation.

When the robot 10 is caused to perform the rotational movement as shown in FIG. 8, the operator inputs a command for the rotational movement from the operation unit 106. CPU 106
This command is stored in the memory 104, and a command is sent to the first control circuit 112 to rotate the first motor 20 at a predetermined rotation speed by a predetermined rotation speed to position the hand 58 at a desired position. The present invention can be applied to the modified or modified embodiment described above without departing from the spirit of the invention.

For example, although the robot for wafer and reticle transfer has been described, the present invention is not limited to this and can be widely used as a general industrial robot. Further, although it has been described that the vacuum air such as the wafer is guided through the air passage formed inside the joint member and the rotary shaft, a through hole is formed in the joint member, and the air pipe is directly passed through the through hole. Good. Also, the steel belt is described as being stretched over the small pulley and the large pulley, but the small pulley and the large pulley may be toothed pulleys and the timing belt may be stretched.

[0033]

As described above, according to the transfer robot of the present invention, a fluid passage can be formed through the second opening hole and the sixth hole portion, so that the robot can be operated. There is an effect that it is possible to provide a transfer robot having a necessary fluid passage accommodated therein.

[Brief description of drawings]

FIG. 1 is a side sectional view of a transfer robot according to an embodiment.

FIG. 2 is a diagram showing a shape of a steel belt.

FIG. 3 is a diagram showing a state in which a steel belt is wound around each pulley.

FIG. 4 is a diagram showing a method of fixing a steel belt to each pulley.

FIG. 5 is a diagram showing a shape of a belt retainer.

FIG. 6 is a view showing a state where the belt is bent.

FIG. 7 is a diagram showing a linear transfer operation of a transfer robot.

FIG. 8 is a diagram showing a rotating operation of the transfer robot.

FIG. 9 is a diagram for explaining the linear transfer operation of the transfer robot in an easy-to-understand manner.

FIG. 10 is a diagram showing a structure of a connecting portion between the base and the first arm.

FIG. 11 is a diagram showing a configuration of a control unit of the transfer robot.

FIG. 12 is a diagram showing a relationship between rotational angular velocity and time.

FIG. 13 is a diagram showing a relationship between a rotation angle and time.

FIG. 14 is a diagram showing the relationship between the rotational angular velocities of the first and second arms and time.

FIG. 15 is a diagram showing the relationship between the rotation angles of the first and second arms and time.

FIG. 16 is a view showing a flowchart for making the hand go straight ahead.

[Explanation of symbols]

 10 Transfer Robot 12 Robot Base 14 Motor Fixed Substrate 16 Bolt 18 First Arm Drive Device 20 First Motor 22 First Rotary Encoder 24 First Reducer 26 First Bearing 28 First Arm 30 First Transmission Lever 32 Connecting member 34 Second arm drive device 36 Joint member 38 Second motor 40 Second rotary encoder 42 Second reducer 44 Second bearing 46 Second arm 48 Second transmission lever 50 Small pulley 52 Third bearing 54 Third arm 56 Rotating shaft 58 Hand 60 Large pulley 62 Steel belt 64 Idler 66,67 Belt retainer 68 Set screw 70,74 Air pipe 72 Signal line 75 Oil seal 76,78,80 Magnetic seal 82,84, 86 O-ring 88 Seal material 100 Control unit 102 CP 104 memory 106 operation unit 112 first control circuit 114 the second control circuit

Claims (1)

[Claims] 1. A cylindrical main body having at least one end opened, and a main body provided so as to close the one end.
A base having a first opening hole formed in a substantially central portion, and a lead portion formed in the lid portion so as to be positioned around the first opening hole, and at least a signal line extending from the inside of the main body portion. A second opening hole that permits the first opening, and a first driving unit that is provided in the main body portion and has a first rotation shaft protruding from the first opening hole to the outside of the base as an output shaft, A first arm having a third projecting hole at one end and a cylindrical projecting part having a projecting end formed at the fourth opening hole at the other end. One end of the first arm is fixed to the first rotation shaft in a state of being inserted into the third opening hole, and the hollow first hollow arm is rotatable around the first rotation shaft. 1 arm and a second rotating shaft that is disposed inside the protrusion and that protrudes from the fourth opening hole to the outside of the first arm. A second driving means having an output shaft, and a second arm having a fifth opening hole into which the projecting end portion is inserted at one end portion, wherein the second rotating shaft has a second opening A hollow second arm having one end fixed and rotatable about the second rotation axis, and a third arm rotatably supported on the other end of the second arm. Fluid-driven gripping means disposed on the third arm, the first opening from the inside of the base via the second opening hole,
Inside the second arm through a sixth hole formed in the second rotary shaft along at least the extending direction of the second rotary shaft. And a fluid passage through which a fluid for driving the gripping means flows.