JPS5858688B2 - Ultra-fine displacement setting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is useful for aligning a workpiece to the center of a rotation axis that draws a reference arc in roundness measurement, or for slightly displacing a workpiece in electron beam processing, or for optical measurement. This device relates to an ultra-fine displacement setting device used when changing the direction of light beam irradiation by a minute angle, etc., and uses two stages of elastic deformation in an integrated scaling mechanism to adjust the input and output displacements. Its feature is that it has excellent linearity.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

The first embodiment shown in FIGS. 1 and 2 is a setting device for positioning minute displacements in one plane. A connecting thin cylindrical part 4 is interposed, and a cylindrical part 5 is provided vertically from the upper pedestal 3 within this thin cylindrical part 4, and these are integrally constructed by facing each other. 6 is screwed so as to be adjustable back and forth, and its tip is brought into contact with the side surface of the columnar part 5 via a steel ball 7.

Thus, when the bolt 6 is rotated in the device 1,
The cylindrical portion 5 is pressed by the bolt 6 via the steel ball 7 and is elastically deformed in the direction of movement thereof, and at the same time, the upper pedestal 3 is also displaced in the same direction.

This deformation of the upper pedestal 3 is caused by the thin cylindrical portion 4 that supports it.
Therefore, the amount of displacement due to the pressure of the bolt 6 is equal to the elastic deformation of the cylindrical part 5, which forms a cantilever beam with one end fixed to the upper pedestal 3 and the other end subjected to a load by the bolt. , elastic deformation of the thin-walled cylindrical part 4, which also forms a cantilever beam, is supported by the lower pedestal 2 at one end and deformed by the upper pedestal 3 at the other end. It will be extracted as an output displacement, so its scale ratio will be large.

The above-mentioned device can be processed extremely easily by simply boring a cylindrical metal material to leave the cylindrical portion 5 and the thin-walled cylindrical portion 4, and the scale ratio is determined by the outer diameter of the cylindrical portion 5 and the It can be set arbitrarily by simply changing the wall thickness of part 4.
Further, although a part of the device is formed thin, it has a cylindrical shape and is connected to the lower pedestal 2, so that it has sufficient rigidity.

In addition, although this device has a two-stage scaling mechanism, it is an integral structure, so the proportional relationship between the input displacement, that is, the amount of displacement of the bolt, and the output displacement, that is, the amount of displacement of the upper pedestal 3 is extremely high. good.

If a larger scale ratio is desired using the same configuration as the first embodiment, as shown in FIG. 3 as a second embodiment,
A thrust bearing 8 and a compression spring 9 are inserted between the bolt 6 and the steel ball 7.

This thrust bearing 8 does not transmit the rotational component of the bolt 6 to the compression spring 9, but only transmits the linear component.
With the above configuration, linearity can exist between the straight movement distance of the bolt 6 and the movement distance of the upper pedestal 3 within a range in which the load characteristics of the compression spring 9 have linearity.

In addition, in order to make the upper pedestal 3 move in parallel as much as possible without tilting, it is possible to push the cylindrical part 5 at a position half the length of the thin cylindrical part 4, as shown in Fig. 3. In this case, this is often achieved by providing a flange portion 10 on the lower pedestal 2 to support the bolt 6, and configuring the cylindrical portion 5 to be pressed through the hole 4a provided in the thin cylindrical portion 4. Can be done.

The third embodiment shown in FIG. 4 is an application of the same mechanism as the first embodiment as a device 11 for minute rotational angle setting by rotational displacement. Round bars 18, 18 are fixed on both sides, and one side of each round bar 18, 18 is pressed in the same rotational direction via steel balls 17, 17 by bolts 16, 16 supported by the lower pedestal 12. They differ in how they are configured.

In this third embodiment, the cylindrical portion 15 is twisted by the advancement of the bolt 16, and at the same time, the thin cylindrical portion 14 is further twisted via the upper pedestal 13. Since it includes two elastic deformations, it has a large scale ratio.

Therefore, this third embodiment is also easy to process,
An arbitrary scale ratio can be obtained by changing the outer diameter of the cylindrical part 15 and the wall thickness of the thin cylindrical part 14, and since it is an integral structure made from a single round bar, the lower part of the cylindrical part 15 can be moved by the advancement of the bolt 16. It is characterized by a good proportional relationship between the rotation angle and the rotation angle of the scaled upper pedestal 13.

In the fourth embodiment shown in FIG. 5, the positioning device 1 by linear displacement of the first embodiment is installed at the bottom, and a third
The device 11 for setting minute rotational angles of the embodiment is mounted, and with this, minute positioning by linear displacement and minute angle setting by rotational displacement can be performed simultaneously.

The scale ratios of linear displacement and rotation angle in each of the above embodiments are as follows.

That is, first, the scale ratio R8 of the displacement of the cylindrical part 5 and the displacement of the upper pedestal 3 at the position where the steel ball 7 abuts is as follows: E: * Coefficient of elasticity G: Modulus of transverse elasticity πd4 I+(-'/64) : Moment of inertia of section of cylindrical part ■2 (-7'(d34-d24)/64): Moment of inertia of section of thin-walled cylindrical part A1 (-7rd12/4): Area of cylindrical part A2 (-7c
(dN-d22)/4): Cross-sectional area of thin-walled cylindrical part, 4 αI (-, -/3): Ratio of maximum shear stress to average shear stress in case of circular cross-section α2 (==2): Doughnut-shaped cross-section Same as above ratio in case 4: Length b of the cylindrical portion to the steel ball contact position: Length dl of the thin cylindrical portion: Diameter d2 of the cylindrical portion: Inner diameter d3 of the thin cylindrical portion: Outer diameter of the thin cylindrical portion.

Next, the scale ratio of the rotation angle in the third embodiment shown in FIG. Polar moment of section p2 (= "(d34-d24)/3°: Moment of cross-sectional area of thin cylindrical portion 4.4: Same as in the above case.

As described above, according to the present invention, two stages of elastic deformation are utilized in the scaling mechanism, and they are integrated into an integrated structure, so that the scale of the displacement of the cylindrical part due to the bolt and the displacement of the scaled upper pedestal is reduced. Not only is the ratio extremely large, but the proportional relationship between the two is also extremely good.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1 and 2 are longitudinal cross-sectional views and bottom views showing the first embodiment of the present invention, and FIGS. 2 to 5 show the second to fourth embodiments of the present invention, respectively. FIG. 3 is a cross-sectional view and a partial cross-sectional view showing an example. 2.12...Lower pedestal, 3,13...
Upper pedestal, 4.14...Thin cylindrical part, 5,15
・・・・・・Cylindrical part, 6.16・・・・Bolt.

Claims (1)

[Claims] 1. A thin cylindrical part is formed between the lower pedestal and the upper pedestal to connect them, and a cylindrical part is suspended from the upper pedestal within the thin cylindrical part to form an integral structure, and the cylindrical part is connected to the lower pedestal. An ultra-fine displacement setting device characterized in that an input displacement of pressing the upper pedestal in the diametrical direction or circumferential direction is extracted as an output displacement of the upper pedestal.