JP2526809B2 - Transfer device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier device, and more particularly to a carrier device used in a semiconductor manufacturing process and required to have a straight advance accuracy.

[0002]

2. Description of the Related Art A transfer device used in a semiconductor manufacturing process (for example, a device called a clean robot)
Has a mechanism for converting rotational movement of a motor or the like into linear movement. As a conventional device, as shown in FIGS. 3 and 4, a first arm 114, a second arm 116, and two sets of belts and pulleys for transmitting the rotation of the motor at a ratio of 1: 2. Are known (U.S. Pat. No. 4897).
No. 015). The motor 120 rotates the arm 116. The shaft 122 and the pulley 124 are rotatable with respect to the arm 116. The arm 116 and the arm 114 are rotatably coupled, the pulley 134 is fixed to the lower side of the arm 114, and the pulley 132 is attached to the arm 116 by the shaft 130. The radius of the pulley 134 is half that of the pulley 124, and a belt 136 is hung between the both pulleys. The hand 112 is the shaft 1
Mounted on the armature 44, the hand 112 is rotatable with respect to the arm 114. The pulley 148 is the hand unit 112.
It is attached to the underside of. The radius of the pulley 132 is 1/2 of that of the pulley 148, and the belt 150 is hung between the both pulleys. When the arm 116 is rotated by the motor 120, the hand unit 112 makes a linear motion indicated by an arrow 160 in FIG. 4 by the action of the arm, the pulley, and the belt described above.

[0003]

In the above-mentioned carrier, since the element for transmitting the power between the arms is not a rigid body, there is a problem that the linear accuracy of the arm itself cannot be guaranteed when the arm length becomes long. there were. The present invention has been made in view of the above points, and an object of the present invention is to provide a transport device with high accuracy of straight traveling.

[0004]

In order to solve the above problems, in the present invention, an internal gear and an internal circumference of the internal gear having a pitch circle diameter of 1/2 of the pitch circle diameter of the internal gear. A pinion meshing with each other, a drive shaft arranged at the center of the internal gear, and a transmission means for transmitting the rotation of the drive shaft to the pinion, and a linear trajectory is drawn on the pitch circle of the pinion as the pinion rotates. The pulley was installed. An expansion / contraction mechanism (for example, a pantograph mechanism) that converts the linear motion of the pulley into another linear motion is provided, the hand part is attached to the tip of the mechanism, and a posture maintaining mechanism is provided to keep the posture of the hand part constant. did.

[0005]

The pulley located on the pitch circle of the pinion in the internal gear draws a straight line path, and the movement of the pulley is converted into another linear movement by the expansion mechanism. Therefore, the hand unit attached to the tip of the expansion / contraction mechanism makes a rectilinear motion.

[0006]

The present invention will be described below with reference to the drawings. FIG. 1 is a schematic plan view of a carrier device according to an embodiment of the present invention. The transport device is functionally divided into two blocks. One is a block having a function of converting a rotary motion into a linear motion, and the other is a block (expansion mechanism) having a function of converting the linear motion into another linear motion.

First, a block for converting a rotary motion into a linear motion will be described. The conveying apparatus of FIG. 1 includes an internal gear 1 and a pinion 2 inside thereof. The ratio of the pitch circle diameters of the internal gear 1 and the pinion 2 is 2: 1. When the pinion 2 revolves the internal gear 1 for one revolution, the pinion 2 rotates for one revolution. Focusing on a point B (a pulley 4 which will be described later) on the pitch circumference of the pinion 2, the locus reciprocates on the diameter of the internal gear 1 by the rotation of the pinion 2. Utilizing this, the motion of the robot is converted from rotational motion to linear motion.

A drive shaft (not shown) rotated by a motor or the like is arranged at the center of the internal gear 1, and a drive pulley 3 is attached to the drive shaft. Pulley 3 and pinion 2
In order to associate with each other, the driven pulley 6 is fixedly arranged on the pinion 2 at a position that coincides with the rotation center of the pinion 2, and the drive pulley 3 and the driven pulley 6 are connected by a timing belt 7 (or chain, gear engagement). At this time, each pulley and a rigid body having a rotational degree of freedom are attached so that the spans of the drive pulley 3 and the driven pulley 6 are constant. In case of gear transmission only, the sum of radiuses of pitch circles should be the span. As a result, the rotational movement of the motor or the like is converted into the revolution movement of the pinion 2 with respect to the internal gear 1. Next, the pulley 4 having a rotational degree of freedom is attached from the pinion 2 using a bracket or the like so that the rotation center is located at a certain point on the pitch circle of the pinion 2. According to the above description, the pulley 4 reciprocates on the pitch circle diameter of the internal gear 1.

Next, a block having a function of converting a linear movement of the pulley 4 into another linear movement will be described. FIG.
The link mechanism (pantograph mechanism) is configured as follows.
In the figure, the links are shown only by solid lines for simplification. Pulleys 5, 15, 1 of the same diameter are attached to each end of the link.
6, 17, 14 are arranged. Only the pulley 5 is constrained from rotating and its position is fixed, the others have a rotational degree of freedom, and the position is movable while being constrained by the link mechanism. The link AE and the link CE are links having the same length. The pulley 15 (position of D) is on the link AE, the pulley 17 (position of F) is on the link CE, and the square BD.
The EFs are arranged so as to form a parallelogram.

If AD: DE = m: n, then AB: BC
Becomes m: n. If the pulley 5 is fixed so that it is on the straight line on which the pulley 4 operates, AB will expand and contract on a certain straight line due to the operation of the pulley 4 (pulley B), and as a result, the pulley 14 will move along the line AB. Linearly move at a position away from A by (m + n) / m times.

A robot hand unit 18 is arranged at the tip of the pulley 14, but in order to keep the direction of the hand unit 18 constant in the linear movement direction, between the pulleys 5 and 16, the pulley 16,
The timing belts 8 and 9 are stretched between 14 parts. Of course, a chain or a steel belt may be used instead of the timing belt.

FIG. 2 is a view showing the expansion and contraction operation of the above-mentioned device, in which the solid line shows the contracted state and the chain line shows the fully extended state. In the case of the expansion and contraction mechanism shown in the figure, the movement of the pulley 4 is enlarged, but the present invention is not limited to this, and by appropriately setting the length of each link, it is possible to perform equal magnification or reduction movement. Good. Further, the expansion / contraction mechanism is not limited to the pantograph mechanism, and another mechanism may be used.

[0013]

As described above, according to the present invention, since the rotary motion is converted into the linear motion by using the internal gear and the pinion, the linear motion accuracy of the robot arm itself is impaired due to the power transmission between the rigid bodies. Can realize linear motion without.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 is a diagram explaining the operation of the apparatus of FIG.

FIG. 3 is a perspective view of a conventional device.

FIG. 4 is a side view of a conventional device.

[Explanation of symbols]

 1 Internal gear 2 Pinion 3 Drive pulley 4 Pulley 5 Fixed pulley 6 Driven pulley 10, 11, 12, 13 Link 14, 15, 16, 17 Pulley 18 Hand part

Claims (3)

(57) [Claims] 1. An internal gear, a pinion having a pitch circle diameter that is ½ of a pitch circle diameter of the internal gear and meshing at an inner circumference of the internal gear, and the pinion is arranged at the center of the internal gear. A drive shaft, a transmission means for transmitting the rotation of the drive shaft to the pinion, a pulley that is on a pitch circle of the pinion and moves on a linear locus with the rotation of the pinion, and a linear motion of the pulley. A telescopic mechanism that converts into another linear motion, and a hand unit attached to the tip of the telescopic mechanism,
A carrier device, comprising: a posture maintaining mechanism for keeping the posture of the hand unit constant. 2. The transfer device according to claim 1, wherein the expansion / contraction mechanism is a pantograph mechanism. 3. The posture maintaining mechanism according to claim 1 or 2, further comprising: a fixed pulley arranged at one end of the telescopic mechanism; and a pulley connected to the fixed pulley by a timing belt and fixed to the hand portion. The transport device described.