JPS5930006A - Long scale device - 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 The present invention relates to a spliced scale for a length measuring instrument, and particularly to a spliced long scale device for an optical length measuring instrument.

When the moving distance of the moving table is large, such as in large machine tools, and the measuring length is 1 meter or more, a single glass scale is no longer long enough. A jointed long scale is used in which scales are joined in the longitudinal direction.For example, as described in Japanese Patent Publication No. 53-33071, a plurality of glass scales may be used as a jointed long scale. A long transparent glass plate is pasted and fixed on top of the glass plate to form a single transparent joined long scale, and according to Japanese Patent Laid-Open No. 54-161-3 "54" As disclosed, there is a known structure in which a number of glass scales are joined together and their edges in the width direction are sandwiched between reinforcing plates and fixed with adhesive to form a single joined long scale.

In each of the above-mentioned jointed long scales, another relatively short reference scale is placed over the joint part, and
The spacing between the joints is adjusted, and in the former known example, the spacing is adjusted by observing the discrepancy in moiré fringes that occur in the overlapping parts of the scales, and in the case of scales with a fine pitch, As the intervals between moiré fringes become narrower or the width of the fringes becomes wider, it is difficult to perform accurate reading and positioning by visual inspection. In addition, in the latter known example, the interval is adjusted by overlapping the bright and dark parts of the scale, but the electrical signal from the photoelectric converter used to detect the overlapping state does not detect the pitch deviation of the scale or the moiré pattern. This is the result of electrolytic corrosion of all changes in the gap between the jointed scales, and even if the school spacing is adjusted based on the electrical signal, it does not necessarily mean that the scale positioning is accurate, and it is not reliable. A highly sensitive long scale cannot be obtained.

Furthermore, in order to adjust the distance between the two known examples mentioned above, both require a large fine adjustment table with a length approximately equal to the length of the two scales joined together. Furthermore, it is extremely difficult to carry out splicing work at a site where machine tools are installed.

On the other hand, a length measuring device as shown in Fig. 1A, which fixes the scale directly to the bed of a machine tool and performs splicing without using a long fine adjustment table as described above, is available from Japanese Patent Application Publication No. It has been published in the published patent publication No. 1983-9962. This jointed elongated scale consists of intermediate support members 2.2 and 2.2 which respectively support glass scales 1.1' and 1.1'.
' is glued to a hollow profile 4.4' via a particularly elastic intermediate layer 3.3', such as rubber in FIG. 1B, and this hollow profile 4.4' is fixed, for example, to the bed of a machine tool. It is configured to In addition, each intermediate support member 2.2'
are each provided with an adjusting screw 5.5' on both end faces, and the head of the adjusting screw 5.5' is adjusted by a pressure spring 7 supported by an end piece 6 provided at both ends of the jointed long scale. The intermediate support member 2.2' is biased into abutment. By adjusting one or both of its adjusting screws 5.5', the spacing of the glass scale 1.1' is adjusted, so that this jointed elongated scale can be used for both the two known methods mentioned above when adjusting the opposite distance. There is an advantage that it is not necessary to specifically install a fine adjustment table as in the example. However, this jointed long scale is provided with a means to correct the difference in the direction perpendicular to the longitudinal direction of each scale on the scale surface, that is, the linearity (curvature) of each scale interval in the length measurement direction. Therefore, when the pitch of the scale band is fine, non-linearity between the joined scales causes the detection signal to become inaccurate at the joint.

The present invention solves the drawbacks of the known long scales as described above, and provides an accurate and reliable scale that allows adjustment of the spacing between the seams between each splicing school, as well as the linearity of each scale. The purpose of this invention is to obtain a long scale device by splicing.

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

FIG. 2 is a plan view of a jointed long scale showing an embodiment of the present invention, FIG. 3 is an elevational view of the embodiment of FIG. FIG. 9 is a sectional view taken along line A-A of FIG. In FIG. 2, two graduation scales 11, 11' are joined by a pair of connectors 12 having approximately the same expansion coefficient as the graduation scales, and a substrate 13 having a length corresponding to approximately two graduation scales. Mounting on top is supported. This coupler 12 includes a scale support 14.14' mounted on the bottom surface 13b of a notch 13a formed in a part of the substrate 13 as shown in FIG.
It is composed of coupling metal fittings 15, 15' fixedly installed on the top, and three adjustment screws 16a, 16b, 16C that connect the coupling metal fittings 15, 15' to each other.

The coupling fittings 15 and 15' are formed into a symmetrical L-shape with protrusions 15a and 15'a, respectively, as shown in FIG. 3, and on the back side thereof, as shown in FIG. Step portions 15b and 15'b are formed. Also, a scale support 14.14' is attached to the bottom surface 13b of the groove of the substrate 13 by a port 17, and coupling fittings 15.15' are fixed to the scale support 14.14' by bolts 18, respectively. Stepped portions 15b, 15
The ends of the graduation scales 11 and 11' are respectively inserted between the 'b' and 'b'. The school support 14 facing the stepped portions 15b, 15'b,] 4' scale adhesive surface 14
Adhesive is applied to a and 14'a, and the inserted scale 11.11' is attached to the adhesive surface 14 by the adhesive.
a and 14'a, respectively.

Note that when the scale scroll 11.11' is fixed with adhesive, the stepped portion 15b115 of the coupling fitting 15.15'
'b is pressed through the holding plate 20 until the adhesive hardens by the set screw 19 screwed into the scale 1.
1.11' is firmly adhesively fixed to the scale support 14.14'.

On the other hand, the protrusions 15a and 15'a of the coupling fittings 15 and 15'
As shown in FIG. Another adjustment screw 16c, which abuts on the other end, is screwed into the central part of the protrusion 1.5'a of the other coupling fitting 15'. With these three adjusting screws 16a, 16b, 16c, the scale 1
1.11' is configured to be relatively movable in the left-right direction of the arrow X shown in FIG.

Further, the depth h of the groove 13a of the substrate 13 is formed to be equal to the thickness of the scale support 14.14' as shown in FIG. The scale 11.11' is configured to be in contact with the upper surface 13c of the substrate 13. Further, on the upper surface of the substrate 13, there is a graduation scale joint part 13d formed with a slight step.
The graduation scale 11.11' is connected to the graduation scale connection part 13d via an intermediate #22 having elasticity like rubber.
is combined with In addition, the graduation scale is 11.11',
After adjustment of both graduation scales, the coupler 12 is protected by an upper cover 24 and a lower cover 25, which have a sealing lip 23 on one edge.

FIG. 5 shows another embodiment of the coupler which forms the main part of the present invention.
This coupler 112 is the same as in FIGS. 2 to 4 except for the substrate 113 and the scale support 114 that supports the graduation scale 11 on the right side, so a description of the same parts will be omitted. In FIG. 5, the left scale support 14'
is fixed on a protrusion 114b extending leftward from the right scale support 114, and a coupler 112 including coupling fittings 15, 15' is integrally formed. Therefore, in this case, the scale support 114, 14' and the substrate 113'
There is the advantage that the graduation scales 11, 11' can be kept in a pre-seamed state without having to be attached to -. Note that in FIG. 5, the intermediate layer 22 is a scale support 114.
It may extend between 114' and the substrate 113.

Now, in the state shown in FIG. 2 with the top cover 24 removed,
After the base plate 13 to which the graduation scale 11.11' is attached together with the coupler 12 is attached to, for example, the bed of a machine tool, a photoelectric detection device for length measurement is attached as shown in FIG. This photoelectric detection device is installed, for example, on a moving table of a machine tool, and includes a detection pace 26 movable along the longitudinal direction of scales 1 and 11', and a seal lip 23.
The photoelectric detection section 28 is connected to the detection base 26 via a connection section 27 that is in contact with the detection base 26 . The photoelectric detection unit 28 is composed of a lamp house 28a equipped with a light source and a condenser lens, and a detection unit 28b facing the lamp house 28a with a graduation scale in between and equipped with a detection index scale and a light receiving element. ing.

The detection index scale is a graduation band 11 ab 11 formed by alternately arranging opaque lines and transparent slits on the back side of the graduation scale 11.11' to be joined.
It has the same scale graduation as a' (see Figure 2).

Next, the operation and assembly adjustment operation of the above embodiment will be explained.

First, before attaching the graduation scale 11.11' to the coupler 12, remove the two adjustment screws at both ends connecting the left and right coupling fittings 15, 15' of the coupler 12], 6a, 16b.
Remove the scale support 14. with the bolts 18.
The coupling fittings 15 and 15' fixed to 14' are separated into left and right sides. Next, adhesive is applied to the scale adhesive surfaces 14a, 14a' of the scale support 14, 14', respectively. Then, these surfaces 14a, 14a' and the coupling fitting 15.1
A graduation scale 11 is placed between the stepped portions 15b and 15'b of 5'.
．． 11' are inserted into the graduation scales 11 and 11' respectively.
．． 11' and coupling fittings 15 and 15' are arranged. Furthermore, the edge of the scale 11.11' is the connecting metal fitting 15.15.
Scale supports 14.14' are installed relative to the graduation scales 11.11', respectively, so as to slightly protrude from the end faces of the protruding portions 15a, 15a', as shown in FIG.

Scale support 14.14' is graduated scale 11.1
After determining the IU to be installed at the end of the scale ]], a holding plate 20 is inserted between the graduation scale ]], 11' and the stepped portions 15b, 15b', and the bolts 18 are tightened.

Further, through this presser plate 20 and with three cent machine screws 19, the scale adhesive surfaces 14a, 14a are attached.
Press down on the graduation scale 11.11' until the adhesive at 11.11' is cured.

Graduation scale 1. L11' is scale support 14.14
′, then the substrate] 3
The intermediate N22 is formed by applying an adhesive, such as a rubber-based adhesive, which remains elastic even after hardening to the scale joint 13d, or by applying a pre-formed plate-like member having elasticity, such as a rubber-based adhesive. An adhesive is applied onto the intermediate layer 22.

Then, before the adhesive dries, scale 1
1.11' All scales are placed on the substrates 1 and 3.The scale support 14.14' provided at the end of the scale scale 11.11' is placed on the entire substrate 1 and 3. Determine the position of scale 11.11'. Furthermore, the longitudinal direction of the scale 11, 11' and the substrate 13
Graduation scale 11 so that h is almost parallel to the longitudinal direction of
．． After determining the direction of 11', each three bolts 1
At step 7, the scale supports 14 and 14' are fixed onto the substrate 13.

Now, once you have finished marking the scales 11 and 11' on the board 13, attach the coupling fittings 15 and 15' to the adjusting screw 1.
6a, 16b, and 16c, the three poles 17' fixing the scale support 14' on the left side in FIG. 2 are slightly loosened. And adjustment screw 16
a, 16b, 16c'e are rotated to attach the coupling fitting 15', scale support 14' and graduation scale 11' to the substrate 13.
1. Adjust the seam spacing and scale band J by slightly moving it. a,
The parallelism (linearity) of 11a' is lI! l Adjust. In this case, the adjustment screw 16C functions to define the seam spacing, and the adjustment screws 16a and 16b on both sides serve as the graduation scale 11'.
The adjustment screw 168 and the receiver function to swing in the y direction as shown in FIG. 2 within a plane including the scale band 11a111a'u-, centering on the point of contact with the metal 21. For this reason, adjustment screw i6
a and 16b are provided so that when tightened, the fitting 15' is drawn toward the fitting 15, and the adjustment screw 16c is provided so that when tightened, the fitting 15' is pushed away from the fitting 15.

As described above, by slightly moving the graduation scale 11', the continuity of the graduation band at the seam, that is, the adjustment to make the seam interval an integral multiple of the scale pinch, and the linearity in the length measurement direction of the graduation scale 11a and 11a' are achieved. Adjustments will be made. At this time, the graduation scale 11' moves slightly with respect to the substrate 13, but since the elastically deformable intermediate layer 22 is provided, the graduation scale 11' curves within the plane including the graduation band 11a'. Never.

After completing this adjustment, scale support 1 on the left
4' to the board 13 with three bolts 17, and then attach the cover 2.
By attaching 4.25, the long scale device is completed.

In this way, according to this embodiment, the three adjustment screws 16a,
Since the screws 16b and 16Qk are used as push screws and pull screws, respectively, the connection between the scales 11 and 11' is extremely strong.

In addition, in the above embodiment, the scale support 14.
14', 114 and the coupling fittings 15 and 15' are all constructed separately, but they may be formed integrally.

Also, among the three adjustment screws used as adjustment means, the adjustment screw 16c in the center is a push screw that widens the interval, and the adjustment screws 16a116X) at both ends are used as pull screws to narrow the interval and bend the scale. Although 75 is configured to function, the same function and effect can be obtained even if the central part is a pull screw and both ends are push L7 screws (41).

Next, other embodiments of the adjustment means in the present invention will be described in the sixth embodiment.
This will be explained based on the diagram. In FIG. 6, the same members as in each of the above embodiments are given the same reference numerals. In this embodiment, among the three adjustment screws described above, adjustment screw 1 is
A tension spring 30 is provided at the position where the connecting fitting 15 is provided.
and pull 15' J: Let it go. Other adjustment screws 1
6a and 16C are provided in the same manner as in the previous embodiment. In this configuration, when the adjusting screw 16a is adjusted, the two scales 11 and 11' are adjusted by adjusting the adjusting screw 16e and the protrusion 1.
5a, the scale bands 11a, Ila"
It is bent in a plane containing e. Furthermore, the adjustment screw 16a
and 16C together, the graduation scales 11 and 11'
The seam spacing changes. That is, the adjusting screw 16c has the function of regulating the joint interval, and the adjusting screw 16a has the function of adjusting the parallelism (linearity in the length measurement direction) of the scale bands 11a and 11a' within the regulated interval. .
'According to this embodiment, since one of the three adjusting screws is replaced with a spring member, there is an advantage that adjustment can be performed extremely easily with only two adjusting screws.

In each of the embodiments described above, the connecting fittings 15, 15' are separate and fixed to the joint ends of the graduation scale ILII'. However, as shown in FIG. 7, similar functions and effects can be obtained by using a metal fitting 115 in which the left and right connecting metal fittings are integrally formed in a U-shape. This metal fitting 115 has a U-shaped open side, that is, a scale 11.11.
Three slots 115a are provided on the closing side of the U-shape so that the adhesive fixed side with
, ' 115b and 115c are provided differently from each other. The protrusions 115d and 115e are extended substantially parallel to the joint direction of the graduation scale. This protrusion 1
5d and 115e are provided with adjusting screws 16a and 16c which operate in the same manner as in the example h7!1 shown in FIG. In this embodiment, the slotted portion of the metal fitting 115 corresponds to the function of the tension spring 30 shown in FIG.

Now, also in this embodiment, the adjusting screws 16a and 16c
When adjusted together, the distance between the protrusions 115d and 115e,
In other words, the seam interval of the scale changes, and the adjustment screw 1
The graduation scale is bent by adjusting 6ai.

This embodiment also has the advantage that adjustment is extremely easy as there are only two adjustment screws, knee/z, and L. Furthermore, since the metal fittings 115 connecting the two scales are integrally formed, The installation of the graduation scale has the advantage that the work is extremely simple and easy.

Since the fitting 115 itself has a biasing force due to the slot, in addition to the two adjustment screws II: l2 (
There is also the advantage that it does not require iTJ or other parts and has an inexpensive configuration.

In each of the above embodiments, the coupling fittings 15.15' and the fittings 115 are not adhesively fixed to the graduation scale 11.11', but are attached to the scale support 14.1 by bolts 18.
4', 114. Therefore, once the above-mentioned adjustments have been completed and the adhesive has dried, the bolts 18 can be loosened and the coupling fittings 15, 15' and the fittings 115 can be removed. This has the advantage that the cross-sectional area of the joint portion becomes small, and an extremely compact length measuring device can be obtained.

As described above, according to the present invention, when joining the graduation scales, a coupler is provided that can adjust the scale interval and the bending of the scales, so that the parallelism and pitch deviation between the graduation scales can be easily adjusted. This can be done reliably by operation. Therefore, when the photoelectric detection device passes through the seam, extremely precise length measurement is possible without any amplitude fluctuation or phase change of the detection signal. Furthermore, since the coupler is also provided with adjustment means for adjustment work, there is an advantage that the device can be made smaller.

[Brief explanation of the drawing]

Figure 1A is a plan view of a conventionally known jointed long scale;
Figure B is a sectional view taken along line B-B in Figure 1A, Figure 2 is a plan view of an embodiment of the present invention, Figure 3 is an elevational view of the embodiment shown in Figure 2, viewed from the graduation scale side, and Figure 4 is a cross-sectional view taken along line B-B in Figure 1A. The figure is a sectional view taken along the line A-A in FIG. 2 in which a photoelectric detection device is added to the embodiment shown in FIG. 2, FIG. FIG. 7 is a plan view showing another embodiment of the adjusting means, and FIG. 7 is a plan view showing another embodiment of the connector in the present invention. 11.11'...Graduation scale 11a,
lla'・・・・・・Graduation band 12.112...
・・・・・・Coupler 13.113・・・・・・・・・Board 28・・・・・・Photoelectric detection device Applicant: Nippon Kogaku Kogyo Co., Ltd. Agent Takashi Watanabe, t16 diagram / Spear 4 Figure 48, f-5 Figure O 6 Figure 0 Off Figure 11 Ro (r II ◇ Jin

Claims (2)

[Claims] (1) A coupler that joins two optical graduation scales together in the length measurement direction; A coupler that is provided on the coupler and connects the two optical graduation scales in the direction of expanding and contracting the seam interval of the two graduation scales; and an adjusting means that can be adjusted in a direction of 7ff1 bending in a plane substantially parallel to the 7ff1 curve, and when the two graduation scales are mounted on the board, the adjusting means adjusts the interval and parallelism of the graduation bands at the joint. A long scale device characterized by being adjustable. (2) The coupler includes first and second coupling members (15) fixed to the joint end sides of the two graduation scales, respectively.
, (15'), and the adjusting means is provided at at least three locations in the extending direction of the joint of the graduation scale, and includes three adjustment screws connecting the first and second connecting members. (16a, 16b・]6C) 17 Among the three adjustment screws, the center adjustment screw adjusts the seam spacing, and the other two adjustment screws adjust the bending of the two graduation scales. The elongated scale device according to claim 4, characterized in that: