JPH08201020A - Moving value reader for measuring apparatus - Google Patents

Abstract

PURPOSE: To provide a moving value reader for a measuring apparatus which achieves a lowering of production costs and a stabilization of a temperature characteristic in indication accuracy by preventing a drop in the accuracy of a graduation line due to the deformation and zigzagging of a scale in mounting and in positioning. CONSTITUTION: This apparatus is provided with a support member 1 having a vertical mounting surface 1a, a main scale 2 so arranged on the support member 1 to let a graduation line be mounted thereon vertically, a plurality of energizing means 3 to press the main scale 2 onto the mounting surface 1a and a head part. Two jutted parts 10 are provided to support the undersurface 2a of the main scale 2 on a surface 1b facing the undersurface 2a thereof of the support member 1. The two jutted parts 10 are so positioned to minimize deformation by the gravity of the main scale 2. Five energizing means 3 are arranged along the length of the main scale 2 and the individual energizing means 3 utilize for energizing forces a reaction of thick rubber 30 deformable elastically in the longitudinal direction of the main scale 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving amount reading device for a measuring machine used in a measuring machine such as a three-dimensional coordinate measuring machine.

[0002]

2. Description of the Related Art A general three-dimensional coordinate measuring machine is shown in FIG. This three-dimensional coordinate measuring machine includes a base 61 on which an object to be inspected is placed, and a bridge 62 arranged on the base 61. The bridge 62 includes right and left columns 62a, 62.
b and an X-axis guide 62c that bridges the upper parts of both columns 62a and 62b, and is movable in the Y-axis direction guided by a Y-axis guide 63 provided on the base 61. The movement amount reading device of the bridge 62 (the movement amount reading device in the Y-axis direction) is provided on the side surface of the base 61 on the Y-axis guide 63 side or near the Y-axis guide 63 on the base 61.
It is arranged parallel to the axial direction. A carriage 64 is supported by the X-axis guide 62c so as to be movable in the X-axis direction. The movement amount reading device of the carriage 64 (the movement amount reading device in the X-axis direction) has an X-axis on the side surface of the X-axis guide 62c.
It is arranged parallel to the axial direction. A spindle 65 is supported on the carriage 64 so as to be movable in the Z-axis direction.
The movement amount reading device of the spindle 65 (the movement amount reading device in the Z-axis direction) is the spindle 6 on the carriage 64.
5 is arranged in the vicinity of 5 in parallel with the Z-axis direction. A probe 66 is attached to the lower end of the spindle 65. The tip of the probe 66 is brought into contact with the surface of the test object while moving, and the size and shape of the test object are calculated from the amount of movement.

Next, the basic structure of a general movement amount reading device will be described with reference to FIG. Since the three movement amount reading devices have the same configurations, the movement amount reading device of the carriage 64 (the movement amount reading device in the X-axis direction) will be described here.

The X-axis movement amount reading device is provided with a support member (not shown) fixed to the side surface of the X-axis guide 62c so as to be parallel to the movement direction of the carriage 64 (X-axis direction), and a scale on this support member. The main scale 70 is fixed by being pressed by a biasing means (not shown) so that the lines are oriented in the vertical direction. The main scale 70 is provided on the carriage 64, and the scale lines of the main scale 70 are photoelectrically read to detect the carriage 64 in the X-axis direction. A head unit 80 that outputs an encoder signal that indicates the amount of movement (the amount of movement of the probe 66 in the X-axis direction).
And a counter circuit (not shown) for converting the encoder signal from the head unit 80 into a count signal capable of counting. In the head portion 80, a light source 81 that illuminates the scale lines of the main scale 70, a collimator lens 82 that collects light from the light source 81, and an index that is arranged so as to cause a diffraction phenomenon between the main scale 70. A scale 83 and a light receiving element 84 that receives the diffracted light from both scales 70, 83 are built in.

In the above-mentioned three-dimensional coordinate measuring machine, in order to realize highly accurate measurement, the carriage 64, the bridge 62 and the spindle which are respectively detected by the moving amount of the tracing stylus 66, that is, the above-mentioned three moving amount reading devices. It is necessary to accurately detect the movement amount of 65. To this end, in each movement amount reading device, (1) prepare a main scale 70 having an indication accuracy corresponding to the desired accuracy of the measuring machine, in which the scale lines are engraved in a correct shape and at intervals.
(2) Both scales 70 capable of obtaining a predetermined diffracted light,
Both scales 70, 83 so that the space of 83 can be secured.
And (3) it is necessary to support the main scale 70 so as not to impair the scale line accuracy and the pointing accuracy of both scales 70 and 83. In particular, the main scale 70 is in the shape of an elongated plate, and the scale line surface on which the scale lines are engraved has a shape that easily undulates. Therefore, it is necessary to support the main scale 70 by a method of correcting the undulations.

8 and 10, the main scale 70 is moved in the X-axis direction or the Y-axis direction so that the main scale 70 is attached to the support member so that the longitudinal direction of the main scale 70 is horizontal and the scale lines are vertical. Each of the conventional examples of the quantity reading device is shown.

In the conventional movement amount reading device shown in FIGS. 8 and 9, the lower end surface 70a of the main scale 70 is mounted on the supporting surface 90a of the supporting member 90 which is machined so as to be parallel to the moving direction of the head portion 80. By mounting, the main scale 70 is positioned with respect to the head portion 80, and the scale line surface 70a of the main scale 70 is attached to the vertical mounting surface 9 of the support member 90 by the plurality of biasing means 100.
The swell of the scale line surface 70a is corrected by pressing it against 0b.

The support member 90 is a guide portion or the vicinity of the guide portion (a side surface of the X-axis guide 62c in the X-axis movement amount reading device, and a Y-axis guide 63 side of the base 61 in the Y-axis movement amount reading device). Fixed on the side surface or near the Y-axis guide 63 on the base 61 so as to be parallel to the moving direction of the movable part (carriage 64 in the X-axis movement amount reading device, bridge 62 in the Y-axis direction movement amount reading device). Has been done. The mounting surface 90b of the support member 90 is processed to have a flatness such that the distance between the scales 70 and 83 falls within an allowable range in which a diffraction phenomenon can occur.

Further, each biasing means 100 is a leaf spring,
Each leaf spring 100 is bent in a semicircular shape at the contact portion with the main scale 70 in order to prevent the main scale 70 from being damaged by a concentrated load (see FIG. 9). Support member 90
Since the support surface 90a of the main scale 70 supports the weight of the main scale 70, the urging force of each leaf spring 100 is
The force may be small enough to bring the entire zero scale line surface into close contact with the mounting surface 90b of the support member 90. The biasing force of each leaf spring 100 is determined by its processing accuracy.

In another conventional movement amount reading apparatus shown in FIGS. 10 and 11, the weight of the main scale 70 is attached to the mounting surface of the main scale 70 and the supporting member 90 by the urging force of a plurality of urging means 101 which are leaf springs. It is supported by the frictional force generated between 90b. Therefore,
The plurality of urging means 101 attach the main scale 70 and the support member 90 with a force for bringing the entire scale line surface 70a of the main scale 70 into close contact with the attachment surface 90b of the support member 90 and a frictional force for supporting the weight of the main scale 70. It is designed to generate a large urging force equal to or larger than the sum of the force generated between the surface 90b and the surface 90b.

[0011]

However, in the conventional movement amount reading device shown in FIG. 8, the supporting surface 90a of the supporting member 90 and the lower end surface 70a of the main scale 70 are separated from each other.
There is a problem that the flatness of the surface must be processed with high accuracy, and the manufacturing cost increases.

Further, in the conventional movement amount reading device shown in FIG. 10, the plurality of biasing means 101 are provided in the main scale 7.
A force for bringing the scale line surface 70a of 0 into close contact with the mounting surface 90b of the support member 90 and a frictional force for supporting the weight of the main scale 70 are mounted on the mounting surface 90 of the main scale 70 and the support member 90.
Since a large biasing force equal to or larger than the sum of the force generated between the main scale 70 and
Main scale 7 that reduces the accuracy of the scale line of 0
In addition to the possibility of 0 deformation, the urging force of the urging means 101 causes the scale line surface 70a of the main scale 70.
The main scale 70 is positioned (the vertical direction of the main scale 70 is adjusted so that the longitudinal direction of the main scale 70 is parallel to the moving direction of the head portion 80) while pressing the main scale 70 against the mounting surface 90b of the support member 90. Therefore, the main scale 70 may be meandered in the vertical direction with the vicinity of each biasing means 101 as an inflection point, which may reduce the accuracy of the scale line of the main scale 70.

Further, in the conventional movement amount reading device shown in FIG. 8, although the friction force is small between the main scale 70 and the support member 90, there are two friction surfaces (contact portions between the opposing surfaces), and In the conventional movement amount reading device shown in FIG. 10, since there is one friction surface having a large frictional force between the main scale 70 and the supporting member 90, the main scale 70 and the supporting member 90 are present in any movement amount reading device. If there is a difference in the coefficient of thermal expansion between the main scale 70 and the temperature of the main scale 70, internal stress is generated in the main scale 70 due to a change in the environmental temperature, and the accuracy of the graduation line is reduced. As a result, there is a problem in that the linearity and reproducibility of the temperature characteristics of the pointing accuracy cannot be obtained.

The present invention has been made in view of the above circumstances, and its object is to reduce the manufacturing cost, prevent the scale from being deformed during mounting and positioning, and prevent the scale line accuracy from being lowered due to meandering. It is an object of the present invention to provide a movement amount reading device of a measuring machine, which is intended to stabilize the temperature characteristic of accuracy.

[0015]

In order to solve the above-mentioned problems, a moving amount reading device for a measuring machine according to a first aspect of the present invention is a guide part for guiding a movable part in a horizontal direction, the movable part and the guide. A support member that is provided on one of the parts and that has a vertical mounting surface, a scale that is mounted on the supporting member so that the scale lines are in the vertical direction, and a biasing means that presses the scale against the mounting surface. A movable part and a guide part, which is provided on the other side of the guide part and photoelectrically reads the graduation line to generate a signal indicating the amount of movement of the movable part. In the movement amount reading device of the measuring machine that measures the movement amount of the scale, the support member has at least two support portions that support the lower surface of the scale.

According to a second aspect of the present invention, there is provided a moving amount reading device for a measuring machine, wherein the urging means has an elastic body which is elastically deformable in a direction perpendicular to the mounting surface and in a longitudinal direction of the scale. The scale is pressed against the mounting surface by an urging force generated by elastic deformation in the vertical direction.

According to a third aspect of the present invention, there is provided a moving amount reading device for a measuring machine, wherein one of the supporting portions is a pin, and the other supporting portion can adjust a height position for supporting the lower surface of the scale. It has become.

According to a fourth aspect of the present invention, in the movement amount reading device for a measuring machine, the urging means are arranged at a plurality of positions along the longitudinal direction of the scale, and one of the plurality of urging means is arranged. Has a stronger urging force than other urging means.

[0019]

In the movement amount reading device for a measuring machine according to the first aspect of the invention, since the lower surface of the scale is supported by at least two supporting portions of the supporting member, the plane of the surface of the supporting member facing the lower surface of the scale is flat. It is not necessary to process the degree of precision with high accuracy and the flatness of the lower surface of the scale with high precision.

Further, since the weight of the scale is supported by at least two supporting portions of the supporting member, the urging force of the urging means may be a force small enough to bring the entire surface of the scale into close contact with the mounting surface of the supporting member.

Further, since the scale is positioned only by placing the lower surface of the scale on at least two supporting portions of the supporting member, the meandering in the vertical direction with the vicinity of the biasing means as the inflection point is made on the scale during this positioning. Does not occur.

According to a second aspect of the present invention, there is provided a movement amount reading device for a measuring machine, wherein the urging means has an elastic body which is elastically deformable in a direction perpendicular to the mounting surface and in a longitudinal direction of the scale. Due to the configuration in which the scale is pressed against the mounting surface by the urging force generated by elastic deformation in the vertical direction, there is a difference in thermal expansion coefficient between the scale and the support member, and when the scale expands or contracts due to a change in environmental temperature. Since the elastic body of the biasing means elastically deforms in the longitudinal direction according to the expansion and contraction of the scale, expansion and contraction due to heat of the scale is not hindered, and linearity and reproducibility are obtained in the temperature characteristic of the scale indicating accuracy.

In the moving amount reading device for a measuring machine according to the third aspect of the present invention, the head portion for moving the longitudinal direction of the scale together with the movable portion in the horizontal direction by adjusting the height of the adjustable supporting portion. Can be easily adapted to the moving direction of.

In the movement amount reading device for a measuring machine according to the fourth aspect of the present invention, one of the plurality of biasing means arranged along the longitudinal direction of the scale has a stronger biasing force than the other biasing means. The position of the scale in the longitudinal direction can be regulated by this one urging means having a strong urging force.
This one biasing means makes it possible to create a neutral point of expansion and contraction due to the heat of the scale.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. In the description of each embodiment, the same portions are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 shows a movement amount reading device of a measuring machine according to a first embodiment of the present invention. This movement amount reading device is used as a movement amount reading device in the X-axis direction or the Y-axis direction of the three-dimensional coordinate measuring machine shown in FIG.

The moving amount reading device of the measuring machine shown in FIG. 1 is a movable part which moves together with a tracing stylus 66 (see FIG. 6) (in the moving amount reading device in the X-axis direction, the carriage 64 and the Y-axis shown in FIG. 6). In the direction movement amount reading device, a guide portion for guiding the bridge 62 shown in FIG. 6 in the horizontal direction (in the X-axis direction movement amount reading device, the X-axis guide 6 shown in FIG. 6).
2c, in the Y-axis movement amount reading device, Y shown in FIG.
The axis guide 63) and the guide portion or its vicinity (the side surface of the X-axis guide 62c in the X-axis movement amount reading device, the Y of the base 61 in the Y-axis movement amount reading device).
The support member 1 is fixed to a side surface on the side of the shaft guide 63 or in the vicinity of the Y-axis guide 63 on the base 61) and has a vertical mounting surface 1a. Further, the movement amount reading device of the measuring machine includes a main scale 2 attached to the support member 1 so that the scale lines are in the vertical direction, and a plurality of biasing means 3 for pressing the main scale 2 against the attachment surface 1a of the support member 1. And a head unit 80 provided on the movable unit and photoelectrically reading the scale line of the main scale 2 to generate a signal indicating the horizontal movement amount (movement amount in the X-axis direction or the Y-axis direction) of the tracing stylus 66 (Fig. 7)) and.

Lower surface 2a of main scale 2 of support member 1
Two protrusions (supporting portions) 10 and 10 for supporting the lower surface 2a of the main scale 2 are provided on the surface 1b opposed to. The two protrusions 10 and 10 are provided at positions where the deformation of the main scale 2 due to gravity is minimum (positions of minimum bending points used when supporting the linear instrument). Specifically, the two protrusions 10 and 10 are provided at positions separated by a distance d of 55.36% of the total length L of the main scale 2 (see FIG. 1).

The two protrusions 10 and 10 are the two protrusions 1.
The height is so set that the longitudinal direction of the main scale 2 is parallel to the moving direction of the head portion 80 when the main scale 2 is placed on the 0, 10. The support member 9
The zero mounting surface 90b is processed to have a flatness so that the distance between the scales 70 and 83 falls within an allowable range in which a diffraction phenomenon can occur.

Five urging means 3 are arranged at substantially equal intervals along the longitudinal direction of the main scale 2. Each urging means 3 has a repulsive force of the thick rubber 30 which is an elastic body elastically deformable in the direction perpendicular to the mounting surface 90b and in the longitudinal direction of the main scale 2 (the elastic force generated by the elastic deformation in the perpendicular direction). Power) of the structure. That is, each urging means 3 is composed of a thick rubber 30 and a plate (for example, a metal plate) 31 to which the rubber 30 is fixed at one end side, and the other end side of the plate 31 is on the side surface 1c of the support member 1. It is fixed with screws (see Fig. 2). The biasing force of each biasing means 3 is determined by the amount of deformation of the thick rubber 30 due to the thick rubber 30 being pressed by the plate 31 toward the main scale 2.

According to the first embodiment described above, the support member 1 has two
Since the lower surface 2a of the main scale 2 is supported by the two protrusions 10 and 10, it is not necessary to process the flatness of the surface 1b of the supporting member 1 that faces the lower surface 2a of the main scale 2 with high accuracy, and It is not necessary to process the flatness of the lower surface 2a of 2 with high precision. Therefore, manufacturing is facilitated and cost can be reduced.

Further, according to the first embodiment described above, since the weight of the main scale 2 is supported by the two protrusions 10 and 10 of the support member 1, each biasing force of the five biasing means 3 is applied to the main scale. The force may be small enough to bring the entire second scale line surface 2b into close contact with the mounting surface 1a of the support member 1. Therefore,
It is possible to prevent the main scale 2 from being deformed by the urging force of each urging means 3, and it is possible to prevent the scale line accuracy from being deteriorated due to the deformation of the main scale 2 during mounting and use.

Further, according to the first embodiment, since the two protrusions 10 and 10 are provided at the positions where the deformation of the main scale 2 due to gravity is minimized, the scale lines due to the deformation of the main scale 2 are provided. The deterioration of accuracy can be suppressed to a minimum.

Further, according to the first embodiment described above, the lower surface 2a of the main scale 2 is provided with the two protrusions 10 and 1 of the supporting member 1.
The scale is positioned only by placing it on the 0 support part, and after this positioning, the thick rubber 30 of each biasing means 3 is applied to the main scale 2 and the plate 31 of each biasing means 3 is placed.
Is fixed to the side surface 1c of the support member 1 with a screw,
Since the mounting of the main scale 2 is completed, the main scale 2 does not meander in the vertical direction with the vicinity of the biasing means 3 as an inflection point when positioning the main scale 2, and the main scale 2 is easily mounted. be able to.

Further, according to the first embodiment, each urging means 3 has the thick rubber 30 which is an elastic body elastically deformable in the direction perpendicular to the mounting surface 90b and in the longitudinal direction of the main scale 2. Due to the structure in which the main scale 2 is pressed against the mounting surface 1a of the support member 1 by the biasing force generated by the elastic deformation in the vertical direction, the difference in thermal expansion coefficient between the main scale 2 and the support member 1 is increased. When the main scale 2 expands or contracts due to a change in environmental temperature, the thick rubber 30 of each urging means 3 elastically deforms in the longitudinal direction in accordance with the expansion and contraction of the main scale 2, so that the expansion and contraction of the main scale 2 due to heat occurs. I can't be disturbed. That is, since the expansion and contraction due to the heat of the main scale 2 is absorbed by utilizing the internal deformation (elastic deformation) of the thick rubber 30 proportional to the load and the displacement, the expansion and contraction due to the heat of the main scale 2 is naturally generated. Therefore, linearity and reproducibility can be obtained in the temperature characteristics of the indication accuracy of the main scale 2. Therefore, it is possible to stabilize the temperature characteristics of the pointing accuracy of the main scale 2.

Further, according to the first embodiment, the biasing force of each biasing means 3 determined by the deformation amount of the thick rubber 30 may be a small force as described above, and the thick rubber 30 Since the change in the repulsive force with respect to the amount of deformation is small, the variation in biasing force due to the variation in the size and shape of the thick rubber 30 is small. Therefore, stable control of each urging means 3 becomes possible.

FIG. 3 shows a movement amount reading device of a measuring machine according to a second embodiment of the present invention.

In this embodiment, the two protrusions 10, 10 are
Instead, the lower surface 2a of the main scale 2 is supported by the two pins 10A and 10A. The two pins 10A and 10A project from the mounting surface 1a of the support member 1 substantially vertically. Also, the two pins 10A and 10
A is provided at a height position such that the longitudinal direction of the main scale 2 is parallel to the moving direction of the head portion 80 when the main scale 2 is placed on these pins.

According to this second embodiment, the two pins 10
Since it is only necessary to provide A and 10A on the mounting surface 1a of the support member 1, it is possible to process the two projections 10 and 10 on the surface 1b of the support member 1 by machining as in the first embodiment. Will be easier. Also, the two pins 10A and 10
Since the frictional force between A and the lower surface 2a of the main scale 2 is small, the expansion and contraction of the main scale 2 due to heat occurs more naturally.

FIG. 4 shows a movement amount reading device of a measuring machine according to a third embodiment of the present invention.

This embodiment is the same as the second embodiment.
Instead of one of the two pins 10A and 10A, a set screw 10B that supports the lower surface 2a of the main scale 2 and whose height position can be adjusted is used. This set screw 10B penetrates the bottom wall portion 1d of the support member 1,
Since it is provided on the bottom wall portion 1d, it is screwed into the screw.

According to the third embodiment, the set screw 10
By adjusting B, it is possible to adjust the height position of the main scale 2 supported at the upper end thereof, and thus it is easy to position the main scale 2 so that the longitudinal direction of the main scale 2 matches the moving direction of the head portion 80. Can be done.

FIG. 5 shows a movement amount reading device for a measuring machine according to a fourth embodiment of the present invention.

In this embodiment, the lower surface 2a of the main scale 2 is replaced with the set screw 10B in the third embodiment.
An eccentric cam 10C whose height position is adjustable is used, and instead of the central biasing means of the five biasing means 3, a biasing means having a stronger biasing force than the other biasing means 3. (For example, a leaf spring) 3A is used. In this biasing means 3A, the contact portion with the main scale 2 is bent into a semi-circular shape in order to prevent the main scale 2 from being damaged by a concentrated load.

The eccentric shaft of the eccentric cam 10C that supports the lower surface 2a of the main scale 2 is rotatably supported by the support member 1 so as to project substantially vertically from the mounting surface 1a of the support member 1. An escape groove 1e is formed on the surface 1b of the support member 1 at a portion facing the eccentric cam 10C.

According to this fourth embodiment, the height position of the main scale 2 can be adjusted by rotating the eccentric shaft and rotating the eccentric cam 10C.

Further, according to the fourth embodiment, since the central biasing means 3A has a stronger biasing force than the other biasing means 3, one biasing means 3A having a strong biasing force causes the main scale 2 to move. The position in the longitudinal direction can be regulated. As a result, it is possible to prevent the main scale 2 from moving when a shock is applied to the three-dimensional coordinate measuring machine.

Further, since the neutral point of expansion and contraction due to heat of the main scale 2 can be created by one urging means 3A having a strong urging force, parts of the same shape can be formed by a motor-driven CNC type three-dimensional coordinate measuring machine. When the automatic measurement is performed by the replay operation, there is no change in the coordinate system caused by expansion and contraction of the main scale 2 due to a change in environmental temperature, and the coordinate system of the measuring machine itself can always be reproduced.

In the above first and second embodiments,
The lower surface 2a of the main scale 2 may be supported at two or more places.

In each of the above embodiments, a coil spring may be used as the elastic body elastically deformable in the longitudinal direction of the main scale 2 instead of the thick rubber 30.

[0051]

As described above, according to the movement amount reading device of the measuring instrument of the invention described in claim 1, since the lower surface of the scale is supported by at least two supporting portions of the supporting member, The flatness of the surface of the member facing the lower surface of the scale does not need to be processed with high precision, and the flatness of the lower surface of the scale does not need to be processed with high precision. Therefore, the manufacturing cost can be reduced.

Further, since the weight of the scale is supported by at least two supporting portions of the supporting member, the urging force of the urging means may be a force small enough to bring the entire surface of the scale into close contact with the mounting surface of the supporting member. Therefore, it is possible to prevent the scale line accuracy from being deteriorated due to the deformation of the scale during mounting.

Further, since the scale is positioned only by placing the lower surface of the scale on at least two supporting portions of the supporting member, during this positioning, the meandering in the vertical direction with the vicinity of the biasing means as the inflection point is made on the scale. Does not occur. Therefore, it is possible to prevent the scale line accuracy from deteriorating due to the meandering of the scale during positioning.

According to the movement amount reading device of the measuring machine of the second aspect of the invention, the urging means has an elastic body which is elastically deformable in a direction perpendicular to the mounting surface and in the longitudinal direction of the scale. However, due to the structure in which the scale is pressed against the mounting surface by the biasing force generated by the elastic deformation in the vertical direction, there is a difference in the coefficient of thermal expansion between the scale and the supporting member, and the scale changes due to a change in the ambient temperature. As the elastic body of the biasing means elastically deforms in the longitudinal direction according to the expansion and contraction of the scale, the expansion and contraction by the heat of the scale is not hindered, and the linearity and reproducibility of the temperature characteristic of the scale indication accuracy can be obtained. . Therefore, the temperature characteristics of the pointing accuracy can be stabilized.

According to the movement amount reading device for a measuring machine of the third aspect of the present invention, the longitudinal direction of the scale is moved horizontally along with the movable portion by adjusting the height of the adjustable supporting portion. It is possible to easily match the moving direction of the moving head. Therefore, the scale can be easily positioned.

According to the movement amount reading device of the measuring machine of the fourth aspect of the invention, one of the plurality of biasing means arranged along the longitudinal direction of the scale has a biasing force higher than that of the other biasing means. Therefore, the position of the scale in the longitudinal direction can be regulated by the one biasing means having a strong biasing force, and the neutral point of expansion and contraction by the heat of the scale can be created by the one biasing means. Therefore, it is possible to prevent the scale from moving when a shock is applied to the measuring machine, and the coordinate system does not change due to expansion and contraction of the scale due to a change in environmental temperature.

[Brief description of drawings]

FIG. 1 is a front view showing a main part of a movement amount reading device for a measuring machine according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a part of FIG. 1 in an enlarged manner.

FIG. 3 is a front view showing a main part of a movement amount reading device of a measuring machine according to a second embodiment of the present invention.

FIG. 4 is a front view showing a main part of a movement amount reading device for a measuring machine according to a third embodiment of the present invention.

FIG. 5 is a front view showing a main part of a movement amount reading device of a measuring machine according to a fourth embodiment of the present invention.

FIG. 6 is a perspective view showing a general three-dimensional coordinate measuring machine.

FIG. 7 is a perspective view showing a basic configuration of a general movement amount reading device.

FIG. 8 is a front view showing a main part of a movement amount reading device of a conventional measuring machine.

FIG. 9 is a perspective view showing a part of FIG. 8 in an enlarged manner.

FIG. 10 is a front view showing a main part of another conventional moving amount reading device of a measuring machine.

11 is a perspective view showing a part of FIG. 10 in an enlarged manner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support member 1a Mounting surface 2 Main scale (scale) 2a Lower surface 3, 3A Energizing means 10 Projection part (support part) 10A Pin (support part) 10B Set screw (support part) 10C Eccentric cam (support part) 62 Bridge ( Movable part) 62c X-axis guide 63 Y-axis guide 64 Carriage (movable part) 66 Measuring element 80 Head part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G01D 5/36 S

Claims (4)

[Claims] 1. A guide part for guiding a movable part in a horizontal direction, a support member provided on one of the movable part and the guide part and having a vertical mounting surface, and a scale line on the support member in the vertical direction. A scale that can be attached to
A biasing unit that presses the scale against the mounting surface, a head unit that is provided on the other of the movable unit and the guide unit, and photoelectrically reads the scale line to generate a signal that indicates the amount of movement of the movable unit. In the movement amount reading device of the measuring machine, which measures the size and shape of the object to be inspected by the movement amount of the movable portion, the support member has at least two support portions that support the lower surface of the scale. Characteristic measuring device movement amount reading device. 2. The urging means has an elastic body which is elastically deformable in a direction perpendicular to the mounting surface and in a longitudinal direction of the scale, and the urging force is generated by elastic deformation in the vertical direction. 2. The movement amount reading device for a measuring machine according to claim 1, wherein is pressed against the mounting surface. 3. The support according to claim 1, wherein one of the supports is a pin, and the other support is capable of adjusting a height position for supporting a lower surface of the scale. The movement amount reading device of the measuring machine described. 4. The biasing means are arranged at a plurality of locations along the longitudinal direction of the scale, and one of the plurality of biasing means has a stronger biasing force than the other biasing means. The movement amount reading device for a measuring machine according to any one of claims 1 to 3.