JP2000117629A - Measuring method and device for inner and outer diameter of circular workpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring method and a device for an inner and outer diameter of a three-point type circular workpiece, being supplied by simple constitution and inexpensively and moreover having durability to perform stable and accurate inner and outer diameter measuring. SOLUTION: This device has a means for coaxially moving measuring piece fitting blocks 13 and 15 equipped with two measuring pieces 11 and 12 and one measuring piece 14 respectively, a means for stopping or fixing the block 13 at a reference position, means 6 and 7 for moving the pieces 11, 12, and 14 so as to abut on the inner or outer peripheral surfaces of a circular workpiece 20, a means for detecting the moving distance of the piece 14, a means for calculating a correction value about the enlargement ratios of the inner and outer diameters of the workpiece from the moving distance of the piece 14, and a means for calculating the inner and outer diameters of the workpiece 20 by multiplying the correction value to the actually measured value of the workpiece 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the inner and outer diameters of a circular work, and more particularly, to a method for installing a circular or donut-shaped work such as a glass hard disk. Also, the present invention relates to an inner and outer diameter measuring method and apparatus for measuring the outer and / or inner diameter of a grinding work in order to determine whether or not the grinding state is correct and to correct the machining work.

[0002]

2. Description of the Related Art Methods for measuring the outer or inner diameter of a work having the above-mentioned shape include a two-point measuring method and a three-point measuring method. The two-point method uses two tracing styluses and has a simple configuration, but lacks centripetality. That is, in the case of a two-point system, 2
Correct measurement cannot be performed unless one of the tracing styluses is located at a position corresponding to the diameter of the work. However, it is often the case that the measurement is performed at a position slightly deviated, and the measurement accuracy varies, which is not practical.

[0003] When measuring the inner diameter by the two-point measuring method, as a countermeasure against the above-mentioned problem, it is also possible to first measure the inner diameter by chucking the outer circumference, and then measure the inner diameter. However, there is a problem that it is not satisfied when the cores of the inner diameter and the outer diameter are shifted. As another method, it is conceivable to perform measurement after accurately aligning the core of the work with the core of the measuring device by some operation. Absent.

On the other hand, a three-point measuring method using three tracing styluses is excellent in the centripetality and can perform a stable and accurate measurement. And a mechanism for moving it to a new location is required, which is complicated and expensive. In addition, there is an unstable factor that each of the three tracing styluses has a sliding surface, so that it becomes large and is easily affected by dust and the like.

[0005]

As described above, the conventional method for measuring the inner and outer diameters of a circular work has many problems. Therefore, the present invention does not have such problems, that is, it is a three-point method. However, an object of the present invention is to provide a method and an apparatus for measuring the inner and outer diameters of a circular work which can be supplied at a lower cost with a simpler structure than the conventional one, and which is durable and capable of measuring the inner and outer diameters with high accuracy and stability. Make it an issue.

[0006]

According to the present invention, a third tracing stylus is moved from a predetermined position while two tracing styluses are located at a reference position. The inner diameter or the outer diameter of the circular work is calculated by multiplying an actual measured value by a correction value obtained from a moving distance of the third tracing stylus until the circular work comes into contact with the peripheral surface or the outer peripheral surface. The above problem was solved by a method for measuring the inner and outer diameters of a circular work.

[0007] The present invention also provides a means for allowing a probe mounting block having two probes and a probe mounting block having one probe to move coaxially,
Means for stopping or fixing the probe attachment block provided with the two probes at a reference position, and contacting the two probes and the one probe with the inner or outer peripheral surface of a circular work. Means for moving the contact element, means for detecting the moving distance of the one tracing stylus, and calculating a correction value relating to the enlargement ratio of the inner and outer diameters of the circular work from the moving distance of the one tracing stylus. And a means for calculating the inner or outer diameter of the circular work by multiplying the measured value of the circular work by the correction value to calculate the inner or outer diameter of the circular work. Settled.

[0008]

Embodiments of the present invention will be described with reference to the accompanying drawings. 1 and 2 show a case where the present invention is configured for measuring the inner diameter of a work. In the drawings, reference numeral 1 denotes a horizontally long support wall, and an LM guide 2 extending in the length direction is laid on one side surface thereof. Is done. On the LM guide 2, a pair of left and right slide tables 4, 5 having an LM block 3 that moves across the LM guide 2 is installed.

At both ends of the support wall 1, an air cylinder-6,
7 is provided, and the rod of one air cylinder 6 is fixed to the one slide table 4 adjacent thereto via a cylinder block 8. The rod of the other air cylinder-7 is
The tip of the tip comes into contact with a stopper 9 fixed on the other slide table 5. However, the tip of the rod and the stopper 9 are not fixed. A spring 10 that acts to move the slide table 4 and the slide table 5 away from each other is provided.

At the lower inner end of the slide base 4, a probe mounting block 1 having two probes 11 and 12 facing downward.
3 is provided, and a tracing stylus mounting block 15 having one tracing stylus 14 facing downward is installed at the lower inner end of the slide base 5. The measuring elements 11, 1 of the measuring element mounting block 13
2 is arranged so as to be located on a line orthogonal to the moving direction of the tracing stylus mounting block 13, and the tracing stylus 14 of the tracing stylus mounting block 15 is arranged on a line equidistant from each of the tracing styluses 11 and 12. (See FIG. 2). Therefore, an isosceles triangle is always formed by the three tracing styluses 11, 12, and 14. It is preferable that the interval between the probes 11 and 12 can be changed.

A recess 16 is formed on the side surface of the slide base 4 on the side of the support wall 1, and a reference stopper 17 that fits in the recess 16 is protruded from the support wall 1. The recess 16 has a sufficient space for the reference stopper 17 to be accommodated therein, and the slide table 4 can be moved within the margin space. In other words, the range of movement of the slide table 4 is regulated by the reference stopper 17.

The upper part of the slide table 5 constitutes a linear scale moving part 18, on which a linear scale fixing part 19 fixed to the support wall 1 is arranged. This moving part 18
In the linear scale composed of the fixed portion 19 and the fixed portion 19, the moving amount of the moving portion 18 with respect to the fixed portion 19 is measured. A linear gauge can be used instead of the linear scale.

In the above configuration, the donut type work 20
When measuring the inner diameter of the air cylinders, the air cylinders 6 and 7 are respectively extended in advance to bring the tracing styluses 11, 12 and 14 close to each other. Then, the work 20 supported vertically movably and freely movably in the horizontal direction is raised so that the three tracing styluses 11, 12, and 14 enter the holes (FIGS. 1 and 2). State).

When the air cylinders 6 and 7 are simultaneously contracted, the tracing stylus mounting block 13 moves backward until the side wall of the recess 16 hits the reference stopper 17. When the tracing stylus mounting block 13 retreats to the home position as described above,
There are a case where the two tracing styluses 11 and 12 just hit the inner peripheral surface of the circular hole of the work 20 and a case where they do not hit yet.

On the other hand, with the retraction operation of the air cylinder 7, the tip of the rod tends to move away from the stopper 9, but since the spring pressure is constantly applied to the slide table 5 by the spring 10 in the retraction direction. Actually, the stopper 9 follows its movement without leaving the tip of the rod, and retreats together with the slide base 5.

The measuring element 1 of the measuring element mounting block 15 will be used soon.
4 comes into contact with the inner peripheral surface of the circular hole of the work 20, and already,
When the tracing styluses 11 and 12 are in contact with the inner peripheral surface of the circular hole of the work 20, the work 20 can no longer be slipped, and the stopper 9 does not follow the rod that extends further. Move away from the rod end. In addition, measuring element 1
If the workpieces 1 and 12 are not in contact with the inner peripheral surface of the circular hole of the work 20, the work 20 is pulled and moved by the tracing stylus 14 until it comes into contact.

The retreat distance of the slide table 5 is detected from a linear scale, that is, a relationship between the moving section 18 and the fixed section 19 installed on the slide table 5, and a work calculated based on the numerical value. The inside diameter of the work 20 is determined by multiplying the inside diameter of 20 (actual measured value) by the correction value.

Next, a method of calculating the correction value will be described with reference to FIG. First, looking at the movement of each of the tracing styluses 11, 12, and 14 in FIG.
1 and 12 move from the initial position to the fixed position regulated by the stopper 17 (from the fixed position to the measuring element 14).
(The distance X to the initial position of the workpiece 20 is known), and the tracing stylus 14 contacts the inner peripheral surface of the circular hole of the work 20 and moves until it stops (moving distance Y). The moving distance Y is measured by a linear scale or a linear gauge. In the present invention, using the sum Z of X and Y, a work 2 is performed as follows.
Calculate the inner diameter of 0. These calculations are performed by computer
Depends on

In FIG. 3B, the reference inner diameter D of the work 20 is set to 20 mm, and the diameter d of the probes 11, 12, and 14 is set.
Is 4 mm, the difference R between the reference radius D / 2 of the work 20 and the radius d / 2 of the tracing styluses 11 and 12 is 8 mm in FIG.
Becomes Since the distance between the tracing styluses 11 and 12 is √2 R, the distance between the center of the tracing styluses 11 and 12 and their midpoint G
The distance E from the intermediate point G to the center of the work 20 is 5.65685 from the square root of (R2 -E2). The distance B from the center of the work 20 to the center of the tracing stylus 14 has the same value as R, and the distance C from the midpoint G to the center of the tracing stylus 14 is obtained as 13.65685 from the formula of A + B. This value of C is equal to the value of Z in FIG.

In the same manner as described above, the inner diameter of the work 20 is set to 2
The value of C when changed to 0.010 mm, 20.003 mm, ... is 13.66892, 13.660.
48, and the difference from the reference diameter is 0.01
207, 0.00363,...
The value of C when changed by 1 mm is 0.01207 times, and the value of C when the inner diameter changes by 0.003 mm is 0.0036.
Since the error appears three times as large, the magnification of the error is 1.
It can be considered 21 times. In other words, conversely, the value of C is obtained, and this is calculated as the reciprocal of this magnification, that is, 1 /.
The inner diameter of the work 20 can be determined by multiplying 1.21 = 0.8264 (correction value).

The error between the determined value and the reference value can be displayed by appropriate means. When the apparatus is mounted on an inner / outer diameter grinding machine, the measured data (error) is immediately fed back. Thus, it is possible to automatically correct the processing dimensions of the work by correcting the position of the grindstone during the inner diameter (or outer diameter) processing of the work. It should be noted that the measurement is carried out in advance by using a master gauge and zero setting is performed in a usual manner.

FIGS. 4 and 5 show the case where the present invention is configured for measuring the outer diameter of the work 20. FIG. In this case, reference numeral 21 denotes a cylinder installed on a gantry 22, the rod of which is fixed to a slide base 23 which is guided and guided by an LM guide. On the slide base 23, a linear gage mounting member 24 for supporting a linear gage 25 is provided.

The protruding head 26 of the linear gauge 25
, A pressing spring 27 having holder cases 28 and 29 at both ends is wound. Rear end holder case 2
9 is fixed to the linear gage mounting member 24 and does not move, but the holder case 28 on the distal end side is not fixed anywhere, and moves as the pressing spring 27 expands and contracts. In this case, the tip of the head of the head portion 26 becomes the tracing stylus 30 corresponding to the third tracing stylus 14, and the tracing stylus 30 holds the holder case 28 when no load is applied to the holder case 28. When the holder case 28 is pressed against the spring pressure of the pressing spring 27, the holder case 28 appears at the tip end opening of the holder case 28.

Reference numeral 31 denotes a work mounting table provided on the gantry 22. Support walls 32 are erected on both sides, thereby preventing the mounted work 20 from being largely displaced. . At the end of the work mounting table 31, a pair of tracing stylus 33,
34 is erected. The measuring elements 33 and 34 may be fixed to the work table 31 or may be movable in the moving direction of the measuring element 14.

In the above configuration, when the work 20 is mounted on the work mounting table 31, the linear gauge 25, in other words, the tracing stylus 30 is moved to the most retracted position by the action of the cylinder 21. Located in. At this time, since no load is applied to the holder case 28, the tracing stylus 30 is immersed in the holder case 28. After the work 20 is mounted, when the tracing stylus 30 advances to a predetermined position, first, the holder case 2
8 presses against the outer peripheral surface of the work 20, and presses the work 20 by the spring pressure of the pressing spring 27, so that the work 20 acts to surely hit the measuring elements 33 and 34.

When the work 20 hits the tracing styluses 33 and 34, the holder case 28 receives a reaction from the work 20 and the pressing spring 27 shrinks. As a result, only the tracing stylus 30 further advances. Will do. Eventually, the slide base 23 hits the stopper and stops at a fixed position (the stop position is set in advance by using a master gauge).
There is a case where it does not hit 0 (when it is smaller than the reference), a case where it hits the work 20 but is not pushed in (when it is equal to the reference diameter), and a case where it hits the work 20 and is pushed in (when it is larger than the reference diameter). . The moving distance of the tracing stylus 30 from the predetermined position is measured by the linear gauge 25, and the outer diameter of the work 20 is calculated based on the measured distance.

Next, a work 20 based on the moving distance is described.
The method of calculating the outer diameter will be described with reference to FIG. FIG.
Looking at the movement of the tracing styluses 30, 33 and 34 in (A), the tracing styluses 33 and 34 are fixed and do not move. The distance X between the midpoint G of the line connecting the centers of the tracing styluses 33 and 34 and the center of the tracing stylus 30 at the initial position is known. Is measured with the linear gauge 25 or the linear scale, the value of the difference Z between X and Y can be known. In the present invention, the difference Z between X and Y
Is used to calculate the outer diameter of the work 20 as follows.

In FIG. 6B, the reference outer diameter D of the work is shown.
Is 65 mm and the diameter d of the measuring elements 33 and 34 is 5 mm, the sum R of the reference radius B of the work and the reference radius d / 2 of the measuring elements 33 and 34 is 35 mm. In addition, probe 3
Since the distance between 3 and 34 is √2R,
The distance E from the center of G.4 to their midpoint G is √2 R
/ 2, that is, 612.5.
The distance A to the center of 0 is 24.74874 from the square root of (R2 -E2). Then, the distance C from the intermediate point G to the tracing stylus 30 is 57.24874 from the formula of A + B.
Is required.

In the same manner as described above, the outer diameter of the work 20 is set to 6
The value of C when changing to 5.01 mm, 65.04 mm,... Is 57.26081, 57.2970
1, and the difference from the reference diameter is 0.012.
07, 0.04827,..., And the error becomes 0.01207 times with the change of 0.01 mm and 0.04827 times with the change of 0.04 mm. .207 times. This means that the value of C is obtained by multiplying the value of C by the reciprocal of this magnification, that is, 1 / 1.207 = 0.8285 (correction value). The diameter can be determined.

[0030]

The present invention is as described above, and according to the method and apparatus according to the present invention, a measuring element obtained by measuring the movement amount of one measuring element with respect to two pairs of measuring elements. The inner or outer diameter of the work can be calculated with high accuracy from the distance error, and unlike the conventional three-point system, it has a simple configuration, is inexpensive, has high durability, and has stable and accurate internal / external measurement. There is a possible effect.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of the device according to the present invention.

FIG. 2 is a bottom view of an embodiment of the device according to the invention.

FIG. 3 is a diagram for explaining a method according to the present invention.

FIG. 4 is a plan view of another embodiment of the device according to the present invention.

FIG. 5 is a front view of another embodiment of the device according to the present invention.

FIG. 6 is a diagram for explaining a method according to the present invention.

[Explanation of symbols]

 6 Air cylinder-7 Air cylinder-9 Stopper-10 Spring 11 Contact element 12 Contact element 13 Contact element mounting block 14 Contact element 15 Contact element mounting block 16 Recessed part 17 Reference stopper-18 Linear scale moving part 19 Linear scale fixed Part 20 Work 22 Stand 23 Slide base 24 Linear gage mounting member 25 Linear gage 26 Head 27 Press spring 28 Holder case 29 Holder case 30 Contact point 33 Contact point 34 Contact point

[Procedure amendment]

[Submission date] December 15, 1999 (1999.12.
15)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 2

[Correction method] Change

[Correction contents]

Claims (4)

[Claims] In a state where two tracing styluses are located at a reference position, a third tracing stylus is brought into contact with an inner or outer peripheral surface of the work from a predetermined position. And calculating the inner or outer diameter of the circular work by multiplying the measured value by a correction value obtained from the moving distance of the third tracing stylus. Measuring method. 2. A means for allowing a probe attaching block having two probes and a probe attaching block having one probe to move on the same axis, and comprising the two probes. Means for stopping or fixing the tracing stylus mounting block at the reference position, and means for moving the two tracing styluses and the one tracing stylus so as to contact the inner or outer peripheral surface of the circular work. Means for detecting the moving distance of the one tracing stylus; means for calculating a correction value relating to the enlargement ratio of the inner and outer diameters of the circular work from the moving distance of the one tracing stylus; Means for calculating the inner or outer diameter of the circular work by multiplying the actually measured value by the correction value. 3. The inner and outer diameter measuring device for a circular work according to claim 2, wherein the two measuring elements and the one measuring element are installed downward. 4. The apparatus for measuring the inner and outer diameters of a circular work according to claim 2, wherein an interval between the two tracing styluses can be changed.