JPH0653915U - Optical reading type linear scale device - Google Patents

Abstract

(57) [Summary] [Purpose] Expand and contract the scale by following the temperature changes.
The purpose is to enable highly accurate measurement. [Structure] Optical read linear scale is scale 50
Alternatively, the optical reading unit 66 is provided. The scale 50 is provided on either the measuring device main body 52 or the moving body 68, and the optical reading section 66 is provided on the measuring device main body 52 or the moving body 6.
8 is provided on the other side. Then, the scale of the scale 50 is read by the optical reading unit 66, and the moving body 6
The movement amount of 8 is detected. In this case, in the scale 50, the central portion 50A is fixed to either the measuring device main body 52 or the moving body 68, and the left and right side portions of the scale are attached to either the measuring device main body 52 or the moving body 66 by the double-sided adhesive tape 64. Are glued through. Then, with the double-sided adhesive tape 64, the scale 50 and the measuring device main body 52 or the moving body 6
The difference in thermal expansion with any one of No. 8 is absorbed. Therefore, the scale 50 expands and contracts following the temperature change.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical reading linear scale device, and in particular, a scale is provided on one member of a measuring device main body or a moving body and an optical reading unit is provided on the other member, and the scale of the scale is read by the optical reading unit. The present invention also relates to an optical reading type linear scale device that detects the amount of movement of a moving body.

[0002]

[Prior art]

 The optical read linear scale device is provided in the measuring device and is used to detect the amount of movement of the stylus of the measuring device. That is, the scale of the optical read type linear scale device is provided in the main body of the measuring device, and the optical reading unit is provided in the moving body provided with the stylus. The optical reading unit reads the scale scale while the stylus is moving. As a result, the amount of movement of the stylus is detected and the shape of the measured object is measured.

If the scale and the device body are made of different materials, it is difficult to set the thermal expansion and contraction rates of the respective materials to the same value. If the thermal expansion and contraction rates of the scale and the main body of the device cannot be set to be the same, the scale and the main body of the measurement device need to be expanded and contracted independently. As a method, a scale is attached to the main body of the measuring device via an elastic member such as rubber (see FIGS. 5 and 6), and a scale is attached to the main body of the measuring device via a leaf spring (see FIGS. 7 and 8). )It has been known.

As shown in FIG. 5, the scale 10 is attached to the measuring device main body 16 with the screws 14, 14 ... via the spacers 12, 12 ,. Has been. A spacer 18 is sandwiched between the screw 14 and the scale 10 at the center of the scale 10. As a result, the central portion of the scale 10 is fixed to the measuring device body 16. An elastic member 22 such as rubber is sandwiched between the washer 20 and the scale 10 at the other mounting portions. Therefore, when the scale 10 and the measuring device main body 16 are thermally expanded and contracted, the elastic member 22 such as rubber is deformed so that each of them can be thermally expanded and contracted independently. In FIG. 6, 24 is an optical reading unit and 26 is a moving body.

Further, as shown in FIGS. 7 and 8, the method of attaching the scale to the measuring device main body via the leaf spring is as follows. The other parts are attached by pressing the leaf springs 29, 29 ... In this case, the pressing force of the leaf springs 29, 29 ... Is smaller than the pressing force when the scale 10 is directly fixed by the holding plate 28. Therefore, the scale 10 can slide with respect to the leaf springs 29, 29 ... For this reason, the scale 10 and the measuring device main body 16 can independently expand and contract by heat. 7 and 8, 30 is a spacer, and 32 is a screw for fixing the spacer 30 to the measuring device body 16.

[0006]

[Problems to be solved by the device]

 However, since the scale 10 needs to be securely attached to the measuring device body 16, it is necessary to press the scale 10 against the measuring device body 16 with a certain pressing force. Therefore, since the elastic member 22 such as rubber has a large deformation resistance and the leaf spring 29 has a large frictional force, the scale 10 and the measuring device main body 16 cannot independently expand and contract by heat. As a result, thermal stress is generated in the scale 10 and the measuring device body 16, so that the measuring device body 16 may be deformed or the length of the scale 10 may not be able to follow the temperature change. Therefore, there is a problem that the measurement accuracy of the measuring device is reduced.

The present invention has been made in view of such circumstances, and an object thereof is to provide an optical reading type linear scale device capable of highly accurate measurement.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a scale on one member of a measuring device main body or a moving body and an optical reading unit on the other member, and reads the scale of the scale by the optical reading unit. In an optical-reading linear scale that detects the amount of movement of a moving body, the center part of the scale is fixed to the one member, and the left and right side parts of the scale are attached to the one member on both sides to absorb the difference in thermal expansion and contraction. It is characterized by being attached via a member.

[0009]

[Action]

 According to the present invention, an optical read linear scale comprises a scale and an optical read section. The scale is provided on either one of the measuring device main body and the moving body, and the optical reading unit is provided on one of the measuring device main body and the moving body. Then, the scale of the scale is read by the optical reading unit to detect the moving amount of the moving body.

In this case, the central part of the scale is fixed to one of the measuring device main body and the moving body, and the left and right side parts of the scale are attached to both the measuring device main body and the moving body on both sides. It is adhered via a member. Then, the double-sided adhesive member absorbs the difference in thermal expansion and contraction between the scale and one of the measuring device main body and the movable body. Therefore, even if there is a thermal expansion / contraction difference between the scale and one of the measuring device main body and the moving body, the scale can expand and contract following the temperature change, preventing the deformation of the measuring device main body. As a result, high precision measurement is possible.

[0011]

【Example】

 An optical reading linear scale device according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a front view of an optical reading type linear scale device according to the present invention, FIG. 2 is an enlarged view of a main part, and FIGS. 3 and 4 are AA sectional views and BB sectional views of FIG. 1, respectively.

As shown in FIG. 1, the scale 50 of the optical reading type linear scale device has a central portion 50 A fixed to a main body 52 of the device. That is, as shown in FIG. 4, the holding plate 54 has a leg portion and a pushing portion and is pressed downward through the screws 56, 56, respectively. Therefore, the leg portion of the pressing plate 54 presses the fixed spacer 58, and the pressing portion presses the central portion 50A of the scale 50. As a result, the central portion 50A of the scale 50 is fixed to the fixed spacer 58 via the pressing plates 54, 54. Since the fixed spacer 58 is fixed to the apparatus body 52 via the screws 60, 60, the central portion 50A of the scale 50 is fixed to the apparatus body 52.

Spacers 62, 62, ... Are fixed to the apparatus main body 52 via screws 63, 63, ... (See FIG. 3) at regular intervals in the longitudinal direction of the scale 50 from the central portion 50A of the scale 50. . The lower surfaces of the double-sided adhesive tapes 64, 64 ... Are adhered to the spacers 62, 62, ..., And the upper surfaces of the double-sided adhesive tapes 64, 64 ... Are adhered to the scale 50.

As shown in FIG. 2, the double-sided adhesive tape 64 has an elastic member 64A such as a sponge in the center, and adhesive portions 64B and 64C are provided on both surfaces of the elastic member 64A. The elastic member 64A is set to have a sufficiently low shear resistance (that is, the deformation resistance of the elastic member 64A is so small as to be negligible) and has excellent heat resistance. Further, the adhesive strength of the adhesive parts 64B and 64C is set so as to support the mass of the scale 50, and is excellent in heat resistance.

Therefore, the scale 50 is adhered to and supported by the device main body 52 at regular intervals in the longitudinal direction, and further, when the scale 50 and the measuring device main body 52 are thermally expanded and contracted, the elastic member 64A is deformed to be independent from each other. And expand and contract with heat. In FIG. 1, 66 is an optical reading unit and 68 is a moving body. The operation of the optical read linear scale device according to the present invention constructed as above will be described.

A case where the thermal expansion / contraction amount of the scale 50 is larger than the thermal expansion / contraction amount of the measuring device main body 52 will be described. Since the central portion 50A of the scale 50 is fixed to the apparatus main body 52, the scale 50 is distributed to both sides from the central portion 50A and thermally expands and contracts. In this case, since the scale 50 has a larger amount of thermal expansion and contraction than the measuring device main body 52, a deviation occurs between the scale 50 and the measuring device main body 52. However, since the scale 50 is adhered to the device main body 52 at regular intervals with the double-sided adhesive tape 64, 64, ..., The deviation between the scale 50 and the measuring device main body 52 is due to the elasticity of the double-sided adhesive tapes 64, 64. It is absorbed by the deformation of the member 64A. Therefore, the scale 50 extends without being constrained by the measuring device main body 52.

The case where the thermal expansion / contraction amount of the scale 50 is larger than the thermal expansion / contraction amount of the measuring device main body 52 has been described above. The same applies to the case where the thermal expansion / contraction amount of the scale 50 is smaller than the thermal expansion / contraction amount of the measuring device main body 52. The effect of can be produced. That is, when the thermal expansion / contraction amount of the scale 50 is smaller than the thermal expansion / contraction amount of the measuring device main body 52, the scale 50 contracts without being restricted by the measuring device main body 52.

[0018]

[Effect of device]

 As described above, according to the optical-reading linear scale device of the present invention, the center portion of the scale is fixed to one of the measuring device body and the movable body, and the left and right side parts of the scale are the measuring device body. Alternatively, it is adhered to either one of the members of the moving body via the two-sided attachment member. Then, the double-sided adhesive member absorbs the difference in thermal expansion and contraction between the scale and one of the measuring device main body and the moving body.

Accordingly, even if there is a thermal expansion / contraction difference between the scale and the measuring device body, the scale can expand and contract following the temperature change, so that the temperature of the scale can be accurately corrected and the measuring device body or It is possible to prevent the deformation of one of the members of the moving body. Therefore, highly accurate measurement is possible. In the embodiment, since the scale is attached to either one of the main body of the measuring device or the movable body via the spacer, the inclination of the scale can be adjusted to adjust the reading value of the scale. Further, the scale can be easily replaced, but the scale can be directly attached to either one of the measuring device main body and the moving body without a spacer.

[Brief description of drawings]

FIG. 1 is a side view of an optical reading linear scale device according to the present invention.

FIG. 2 is an enlarged view of a main part of an optical reading linear scale device according to the present invention.

3 is a sectional view taken along the line AA of FIG.

4 is a sectional view taken along line BB of FIG.

FIG. 5 is a side view of a conventional optical reading type linear scale device.

6 is a sectional view taken along line AA of FIG.

FIG. 7 is a sectional view of a central portion of another embodiment of a conventional optical reading type linear scale device.

FIG. 8 is a left and right side sectional view of another embodiment of the conventional optical reading type linear scale device.

[Explanation of symbols]

 50 ... Scale 50A ... Central part of scale 52 ... Measuring device main body 64 ... Double-sided adhesive tape (double-sided adhesive member) 66 ... Optical reading unit 68 ... Moving body

Claims (1)

[Scope of utility model registration request] 1. A scale is provided on one of the measuring device main body and the moving body, and an optical reading unit is provided on the other member, and the scale of the scale is read by the optical reading unit to detect the moving amount of the moving body. In the optical reading linear scale, the central portion of the scale is fixed to the one member, and the left and right side portions of the scale are bonded to the one member via double-sided adhesive members that absorb thermal expansion difference. Optical reading type linear scale device.