JPS6263207A - Gripper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a gripping device, for example, a gripper suitable for gripping a semiconductor wafer basket in a clean room.
It is related to.

In order for ICs (integrated circuits) that make full use of conventional semiconductor technology to meet the demands for higher performance and higher integration, it is necessary to minimize the contamination of impurities such as dirt and dust during the manufacturing process of semiconductor devices. semiconductors must be processed in a manner that protects them and maintains their high purity. For this reason, the idea of having robots, rather than humans, process semiconductors in clean rooms has attracted attention, and has actually been implemented.

FIG. 7 shows an example of such a robot. According to this robot, one end side of the first arm part 1 which can rotate once is attached to the support shaft part 2 so as to be able to move up and down, and the other end side is attached to the support shaft part 2 so as to be able to move up and down. A second arm portion 3 is also rotatably attached, and an arm portion (output shaft) 4 for gripping semiconductors is provided on the second arm portion 3 so as to be movable up and down. Note that in this robot, harmonic drives 5 are provided at necessary locations as coaxial reduction gears that are small and have a simple structure.

In this robot, the arm section 4 is provided with a gripper 6 for gripping an article (work) such as a semiconductor wafer basket. This gripper 6 can be configured to grip a workpiece between a pair of fingers. however,
When gripping, it is necessary to align the center with the workpiece clipper 6 (centering), but determining the position of the workpiece for this purpose is troublesome and takes a considerable amount of time.

If the position of the workpiece is misaligned or the gripper stops accurately, the finger closest to the object may drag the workpiece after contacting the workpiece, causing extra force or shock to the workpiece. be. especially,
When the workpiece is a wafer basket, undesirable situations occur such as the semiconductor wafer being rubbed against the basket wall surface, generating dust, or being displaced within the basket. However, in reality, the above-mentioned center alignment is impossible, and the above-mentioned extra force and shock are applied in response to the inevitable positional deviation.

An object of the present invention is to be able to grip the object reliably even if the positioning between the object to be gripped and the gripping device is insufficient, and to avoid applying excessive force or shock to the object. The objective is to provide a gripping device that does not require

D0 Structure of the Invention That is, the present invention comprises: a pair of gripping members that grip a predetermined object; a moving means for moving these gripping members in a gripping direction; one of the pair of gripping members making contact with the object. The present invention relates to a gripping device having a moving mechanism that moves the other gripping member to a position where it contacts the object while maintaining this contact state.

E. EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to FIGS. 1 to 6.

Regarding FIGS. 1 and 2, the gripper 16 of this embodiment
The configuration of is explained.

This gripper 16 is fixed via a base plate 10 onto the arm portion 4 of a robot as shown in FIG. A centering block 11 and a centering unit 12 are provided on the fixed base plate 10, and a worm wheel 14 is further provided concentrically with the rotating shaft 13 of this unit 12. This worm wheel (A) 14 is coaxially rotated at the same time as the centering unit 12, and its rotating shaft 15 is inserted into a cylindrical shaft portion 16 via a bearing, and a movable base plate 17 is attached to this cylindrical shaft portion 16. Fixed.

A sliding block 19 is fixed below the movable base plate 17 and is slidably fitted to a guide block 18 fixed to the fixed base plate 10, and these two blocks constitute a slide unit 20. The slide units are arranged at four locations below the movable base plate 17.

Further, a link 21 is fixed to the worm wheel 14 so as to be coaxial and rotatable at the same time, and separate links 22 and 23 are rotatably connected to both ends of this link 21. A finger 24.25 is also rotatably connected to the end of 22.23. Although only one link 23 side is shown in FIG. 2, the other link 22 side is also not shown, but the link 23 side (
q) Are similarly configured.

Spring 26.27 is connected to pin 28.29.30.3 between link 22.23 and worm wheel 14, respectively.
It is fixed via 1. Reference numerals 32 and 33 in FIG. 1 are stopper pins that regulate the position of the lever 21. The side surface of the worm wheel 14 is provided with teeth that mesh with a worm 37 that is rotationally driven via a pinion 35 and a gear 36 connected to the rotation shaft of the motor 34, so that the worm wheel 14 is rotated in a predetermined direction (i.e., clockwise). (or counterclockwise).

Additionally, four slide units 40 each consisting of a guide block 38 and a sliding block 39 are arranged at predetermined positions of the fingers 24 and 25. This slide unit 40 is similar to the slide unit 20 described above, with the sliding block 39 fixed to the lower surface of the finger 24.25 and the guide block 38 fixed on the movable plate 17.

Next, the operation of the gripper 16 of this embodiment will be explained in FIGS. 3 to 6.
The explanation will also include figures.

First, as shown in FIG. 1, a workpiece (for example, a wafer basket containing semiconductor wafers) 41 is positioned between a pair of fingers 24 and 25. However, in this case, generally the play between the workpiece 41 and its positioning guide (42 in Fig. 6) must be kept at around ±1 to 2N.
As shown in the figure, the center of the workpiece 41 and the center of the gripper 16 are misaligned.

During operation, the rotation of the worm wheel 14 (first
counterclockwise in the figure), each finger 24.25
are simultaneously moved in the gripping direction via links 22.23 by springs 26.27. At this time, when the fingers 24 and 25 are open, the centering unit 12 on the base plate 10 is in contact with the block 11 as shown in FIG. 3, and there is no gap between them, so both fingers 24 and 25 are They will be moved equally and simultaneously by the slide unit 40 (ie, the movable base plate 17 is fixed in position at that point).

However, when one finger 24 contacts the workpiece 41 first, further rotation of the worm wheel 14 causes the centering unit 12 to come off the block 11 as shown in FIG. The maximum gap a occurs in (however, in Figure 4, finger 2
4.25 shows the state when the workpiece 41 is gripped).

Therefore, after one finger 24 comes into contact with the workpiece 41, the gap between the unit 12 and the block 11 gradually expands, but the finger 24 that came into contact with the workpiece 41 no longer It cannot move and remains pressed against the workpiece 41 by the force of the spring 26. Therefore, along with the other finger 25, the movable base plate 17 is also -74
is moved in the direction of the finger 24. That is, after the finger 24 comes into contact with the workpiece 41, the combined force of the weight of the workpiece 41 and the frictional force on the mounting surface is applied to the finger 24.
Since the gripper 16 exceeds the pressing force caused by the finger 24, the entire gripper 16, including the finger 25 and the movable base plate 17, is forced to move toward the finger 24 due to the reaction force. This movement is performed easily and smoothly because the movable plate 17 is guided by the slide unit 20 described above.

Then, when the finger 25 comes into contact with the workpiece 41 (
In the state shown in FIG. 4), the workpiece 41 is held between the fingers 24 and 25.

Next, as shown in FIG. 6, when the workpiece 41 held between the fingers 24 and 25 is lifted above its positioning guide 42 and the worm wheel 14 (i.e., the centering unit 12) is further rotated by 45 degrees, the fingers 24 and 25 are 25 holds the workpiece 41 in its position, while the gripping force is exerted by the spring 26.2.
It increases by the amount that 7 increases. At this time, since the fingers 24 and 25 are connected by the links 21, 22, and 23, the workpiece 41 and the fingers 24 and 25 will not be misaligned. When the centering unit 12 rotates 45° as described above and reaches the state shown in FIG. 5, the movable base plate 17, which has been misaligned due to the above-mentioned movement, is forcibly aligned with the fixed base plate 10. It turns out. That is, unit 12
While rotating until it reaches the state shown in FIG. 5, the unit 12 rotates while being moved by the fixed block 11 so that the center of rotation of the unit 12 itself coincides with the center between the blocks 11-11.As a result, A movable base plate 17 (and thus gripper 16) coaxial with the unit 12 is centered on the fixed base plate 10. In other words, the workpiece 41 moves to the upper position 24 while being held by the fingers 24 and 25, so that the workpiece 41 and the
/ The centers of the par 16 will be perfectly aligned.

As explained above, the gripper 16 according to this embodiment
Because of the presence of the slide units 20 and 40, after one finger 24 comes into contact with the workpiece 41, the entire body is moved toward the same finger via the movable base plate 17, so that the workpiece 41 is not dragged or shocked. It can be gripped securely without any need for grip. However, in addition to the presence of the movable base plate 17, due to the combination of the centering unit 12 and the centering block 11, the gripped workpiece 41 can be moved by the gripper 1.
6 can always be centered. Therefore,
Even if the positioning accuracy of the workpiece 41 and the stopping accuracy of the gripper 16 are poor, both can always be set at the desired position.

Although the present invention has been illustrated above, the embodiments described above can be further modified based on the technical idea of the present invention.

For example, the finger moving means, movable base plate moving mechanism, and centering mechanism described above may be modified in various ways. In this case, the connection and movement of the fingers is not limited to the link described above, and the structure of the slide unit and its guide direction may also be varied. Further, the gripping force by the fingers is not limited to the above-mentioned spring C11) force, and other pressing force applying methods may be used. Although the present invention is suitable for use in a clean room when applied to gripping a semiconductor wafer basket, it is of course applicable to gripping other workpieces (articles).

Effects of the Invention As described above, in the present invention, after one gripping member is brought into contact, the other gripping member is moved while maintaining this state.
−−・ →Huhe Folin Rate Since the object is moved to the contact position, even if the object is misaligned, it can be reliably gripped without dragging the object or applying shock.

[Brief explanation of the drawing]

1 to 6 show embodiments of the present invention, in which FIG. 1 is a plan view of the gripper, FIG. 2 is a partially sectional rear view of the gripper, and FIGS.
5 are plan views showing the operation of the centering mechanism, and FIG. 6 is a front view showing the situation in which a work is lifted. FIG. 7 is a schematic diagram of a conventional robot. In addition, in the symbols shown in the drawings, 10...Fixed base plate 11...
...Center alignment block 12...
...Center alignment unit 14...
Worm wheel 17...Movable base plate 18.38...Guide block 1
9.39・・・・・・Sliding block 20.40・
......Slide unit 21.22.23.
・・・・・・・・・Link 24.25・・・・・・・・・
Finger 26.27・・・・・・Spring 4
1... Work (article) 42...
...It is a positioning guide.

Claims (1)

[Claims] 1. A pair of gripping members for gripping a predetermined object; A moving means for moving these gripping members in a gripping direction; After one of the pair of gripping members contacts the object, this contact state is maintained. and a moving mechanism that moves the other gripping member to a position where it contacts the object.