JPS6134019B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a displacement reduction mechanism for reducing and transmitting human displacement, and particularly to a displacement reduction mechanism suitable for use in a precision fine movement table of a positioning device.

As a positioning device, for example, a device for mutually positioning a mask or takele and a wafer in semiconductor manufacturing equipment is known. In particular, when manufacturing such a semi-moving body, precise positioning accuracy is required, and therefore, for example, a precision fine movement table is used for fine movement of the wafer.

FIG. 1 shows an example in which a conventional displacement reduction mechanism is applied to a precision fine movement table.

The shaft of the motor 1 is connected to the feed screw 2 via a coupling ring 7. The feed screw 2 holds a slider 2' that reciprocates as the feed screw 2 rotates. Further, the feed screw 2 has a bearing 8,
Supported by 9. A link 3 is connected to the slider 2' via a pivot 12.
Link 3 is connected to link 4 via pivot 13. The link 4 is supported by a pivot 14 fixed to the support member 11, forming a fulcrum B. The other end of the link 4 is connected to the link 5 by a pivot 15. Link 5 is connected to fine movement table 6 by pivot 16. Further, a spring 10 is provided to eliminate backlash at each joint.

The effect will be explained below. Rotation by the motor 1 is converted into linear motion by the feed screw 2,
A of link 4 via link 3 as input displacement P
Acts on a point. The input displacement P is transmitted to the output point C by the rotation of the link (reducing rod) 4 with point B as the fulcrum, and is reduced to the ratio of the distance between AB and the distance between BC, and is transmitted from point C via link 5. , fine movement table 6
acts as an output displacement Q.

Here, the structures of the conventional fulcrum part and output point part are as shown in FIGS. 2, 3, and 4. 3 is a sectional view taken along line DD in FIG. 2, and FIG. 4 is a sectional view taken along line EE in FIG. The same reference numerals as in FIG. 1 indicate the same parts.

Now, paying attention to the pivots of the fulcrum part B and the output point part C, the structure thereof is particularly as shown in FIG. That is, pivot bearings 14a and 15a are fixed to opposing planes of the link 4, respectively. A pivot set screw 14b is screwed into the fulcrum support member 11.
A pivot 14 is formed by the tip of the pivot 4b pressing against the pivot bearing 14a. Further, a pivot set screw 15b is screwed into the link 5,
The tip of the pivot set screw 15b is the pivot bearing 15
A pivot 15 is formed by pressing a. Here, as is clear from FIG. 3, the fulcrum support member 11 and the link 5 that are adjacent to each other each have a predetermined width. Therefore, as shown in FIG. 2, the distance between the center of the pivot 14 of the fulcrum support member 11 and the center of the pivot 15 of the link 5 is
BC is finite. This distance is the distance between the fulcrum and the output point on the reduction rod, and the fact that this distance is finite means that it is not possible to obtain an infinitely large reduction ratio. Therefore, in order to obtain a large reduction ratio, the distance between A and B must be increased, but it is necessary to combine two or more stages of reduction rods. FIG. 5 shows a conventional example in which reducing rods are combined in two stages. Rotation by the motor 1 is converted into linear motion by the feed screw 2 supported by bearings 8 and 9 via the coupling 7, and acts as an input displacement P on the K point of the link 4' via the link 3. The input displacement P is reduced to the ratio of the distance between LM and the distance between KL by rotating the link (reducing rod) 4' around point L, and acts on the link 18 from point M as an output displacement R. Output displacement R is link 18
The input displacement R acts as an input displacement to the S point of the link (reduction rod) 4'' through the rotation of the link 4'' around the T point, and is reduced to the ratio of the distance of UT and the distance of TS, and becomes U. This acts as an output displacement Q on the fine movement table 6 from the point via the link 5.
Incidentally, each of the reduction rods is provided with a spring 10' for the purpose of eliminating bumps in each part. The rotation pairs of each part are pivots 12, 13', 14',
15, 15', and 16, and in particular, the pivot 14' of the fulcrum part is supported and fixed by the fulcrum support member 11'. However, when reducing rods are used in multiple stages in this way, the device becomes large and has a large number of joints, which leads to problems in that assembly and manufacturing errors become large. Due to the accumulation of such errors, precise positioning of the fine movement table has been impossible. It is also possible to increase the reduction ratio by increasing the distance between AB in one stage, but this poses the problem of increasing the size of the device.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a displacement reduction mechanism that has a compact structure, has high positioning performance, and can obtain a large reduction ratio.

A feature of the present invention is that the fulcrum portion pivot and the output point portion pivot of the reduction rod are formed on different planes.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 6 shows a displacement reduction mechanism according to an embodiment of the present invention applied to a precision fine movement table. The same reference numerals as in FIG. 1 represent the same parts. Rotation by the motor 1 is converted into linear motion by the feed screw 2, and acts as an input displacement P on point F of the link 21 via the link 3. A block 22 is fixed to the other end of the link 21. The block 22 and the fulcrum member 23 are connected by a pivot 14 to form a fulcrum G. Also, block 22
and an output point member 25 are connected by a pivot 15 to form an output point H. The input displacement P is reduced to the ratio of the distance between GH and the distance between FG by the rotation of the link (reduction rod) 21 around point G, and is transmitted from point H through the output point member 25 and the roller bearing 24. is transmitted to the fine movement table 6 via. In addition, a spring 27 is provided in the spring 21 on the reduction rod 21 for the purpose of eliminating buckling of each part, and a spring 26 is provided on the fine movement table 6 in order to eliminate the deflection of the roller bearing 24. . In such a displacement reduction mechanism, the configuration of the rotating pairs G and H points is as shown in FIGS. 7, 8, and 9. Figure 8 is I- of Figure 7.
9 is a sectional view taken along JJ line in FIG. 8. In particular, the configuration of the fulcrum G and the output point H will be explained using FIG. Block 22
is E-shaped as shown. Block 2
Pivot bearings 14a are fixed to the upper and lower tiers of 2. A pivot set screw 14b is screwed into the fulcrum member 23, and the tip of the pivot set screw 14b presses the pivot bearing 14a to form the pivot 14. This pivot 14
acts as a fulcrum G. Also, block 22
A pivot bearing 15a is fixed to the middle stage. The output point member 25 has a pivot set screw 15b.
is screwed in, and the tip of the pivot set screw 15b presses the pivot bearing 15a to release the pivot 15.
is formed. This pivot 15 acts as the output point H.

The pivot 15 is assembled as follows. That is, holes are formed in advance at positions corresponding to the upper and lower pivot setscrews 15b of the block 22. Through this hole,
The pivot set screw 15b is screwed into the pivot bearing 15a. After the pivot 15 is assembled, a press-fitting member 28 is press-fitted into the hole of the block 22. The pivot bearing 14a is fixed between this pressure member 28 and the original block 22, and the pivot 1
4 is assembled.

Here, unlike the conventional example shown in FIG. 3, in FIG. 8, the fulcrum pivot and the output point pivot are formed on different planes of the block 22. Therefore, when considering the case where the output point H rotates around the fulcrum G, the fulcrum member 23 and the output point member 25 do not come into contact with each other. Therefore, the distance GH between the fulcrum G and the output point H can be made infinitely close to zero. The distance GH affects the reduction ratio, and an infinitely large reduction ratio can be obtained.

In the above explanation, it is assumed that input points and output points are formed at both ends of the fulcrum.
An output point may be provided between the input point and the fulcrum, or the block 22 may be made integrally with the link 21.

According to one embodiment of the present invention, the displacement reduction mechanism includes:
Since it can be formed with a one-stage structure, it is extremely compact, has high positioning properties, and can obtain a large reduction ratio.

Other embodiments of the present invention FIGS. 10 and 11
This will be explained using FIGS. FIG. 11 is a NN cross-sectional view of FIG. 10, and FIG. 12 is a cross-sectional view of the first
FIG. 1 is a cross-sectional view taken along line V-V in FIG. Also, Figures 7 and 8
The same reference numerals as in FIG. 1 and FIG. 9 represent the same parts. As shown in FIG. 11, the block 29 has a U-shaped cross section. And screws 32, 33, 34, 35
It is fixed to the link 21 by. A pivot bearing 15a is fixed to the output point member 31. A pivot set screw 15b is screwed into the block 29, and the pivot 15 is formed by the pivot set screw 15b and the bearing 15a. This pivot 15 acts as an output point H. Pivot set screw 15 of block 29 and link 21
A press-fitting member 30 is press-fitted into the hole at the position corresponding to b, and the pivot bearing 14a is further fixed. A pivot 14b screwed into a fulcrum member 23 is pressed against the pivot bearing 14a to form a pivot 14. This pivot 14 acts as a fulcrum G. Therefore, similarly to the above embodiment, the distance GH between the fulcrum G and the output point H
can approach zero infinitely.

In the above description, the input point and the output point are formed at both ends of the fulcrum, but the output point may be provided between the input point and the fulcrum. Further, the block 29 and the link 21 may be made integrally.

In this embodiment, the gap between the pair of pivots 15 constituting the output point H, that is, the thickness of the output point member 31 in FIG. 11 is configured to be large. That is, block 22 in FIG.
In contrast to the E-shape shown in FIG. 11, the block 29 is made into a U-shape, and by holding the output point member 31 with a pivot screw on the block 29 side, it is possible to increase the distance between the pivots 15. There is. In this way, by increasing the distance between the pivots 15, even if a misalignment of the axes between a pair of pivots 15 occurs due to machining accuracy,
The inclination of the output point member 31 can be reduced. By making the inclination small, deterioration of the linearity of displacement when the output point member 31 is displaced about the fulcrum G can be prevented.

Further, when the pivot set screw 15b of the pivot 15 is screwed in, the upper and lower parts of the U-shaped block 29 are subjected to a force that bends outward. On the other hand,
By screwing in the pivot screw 14b of the fulcrum member 23, the U-shaped block 29 receives an inward force. Therefore, the two are offset and the deformation of the block 29 is reduced.
Therefore, deterioration of the linearity of displacement can be prevented.

According to other embodiments of the present invention, the displacement reduction mechanism can be configured to be extremely compact and capable of high-level positioning, and moreover, it is possible to obtain a large reduction ratio.

Furthermore, a displacement reduction mechanism with good linearity can be obtained.

Furthermore, as is clear from the above explanation, the distance between the fulcrum and the output point can be made infinitely small, and therefore,
An infinite reduction ratio can be obtained. However, if a reduction ratio of several orders of magnitude is to be obtained, an overload will be applied to the fulcrum, which is impractical. In order to obtain such a reduction ratio of several orders of magnitude, it is possible to use a plurality of stages of the displacement reduction mechanism according to the present invention. Even in this case, the number of stages is small and accurate positioning is possible, compared to the case where a conventional displacement reduction mechanism is used in multiple stages.

According to the present invention, the displacement reduction mechanism can be configured to be extremely compact and capable of high-level positioning, and moreover, it is possible to obtain a large reduction ratio.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a precision fine movement table using a conventional displacement reduction mechanism, FIG. 2 is a partial plan view of the conventional displacement reduction mechanism, and FIG.
-D sectional view, FIG. 4 is a sectional view taken along EE in FIG. 2, and FIG.
Fig. 6 is an explanatory diagram of the precision fine movement table used in the stage.
FIG. 8 is an explanatory diagram of a precision fine movement table using a displacement reduction mechanism according to an embodiment of the present invention, FIG. ―
9 is a sectional view taken along line JJ in FIG. 8, FIG. 10 is a partial plan view of another embodiment of the present invention, and FIG. N-N
12 is a sectional view taken along the line V-V in FIG. 11. FIG. 14,15...Pivot, 21...Link, 2
5, 31... Output point member.

Claims (1)

[Claims] 1. A reduction rod whose center of rotation is a fulcrum and whose reduction ratio is the ratio of the distance between the input point and the fulcrum to the distance between the fulcrum and the output point, a pivot that supports the fulcrum of this reduction rod, and the reduction rod described above. an output transmission rod that transmits the output displacement from the output point of the rod; and an output transmission rod that supports the output transmission rod at the output point of the reduction rod, and that supports the pivot of the fulcrum part on a plane parallel to the plane in which the reduction rod rotates. A displacement reduction mechanism comprising a plane and a pivot formed on a different plane.