JPH0540031A - Noncontact measuring instrument - Google Patents

Abstract

PURPOSE:To obtain a noncontact measuring instrument which can measure the dimension of an object to be cut during the cutting operation of the object. CONSTITUTION:The distance DELTAx to the outer periphery of an object 1 to be cut is measured by means of an eddy-current sensor 3 and the distance l to a mirror 5 is measured by means of an optical length measuring instrument 4. A control unit 8 calculates the diameter of the object 1 on the basis of the distances DELTAx and l, the distance C between the mirror 5 having a fixed length and front end of the sensor 3, and the distance L to the center of the object 1 measured in advance by means of the instrument 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact measuring device for measuring the size of an object being cut by a cutting machine in a non-contact manner.

[0002]

2. Description of the Related Art FIG. 2 conceptually shows a conventional method for measuring the dimensions of an object to be cut.
1 is an object to be cut, 2 is a grindstone or cutting tool for a cutting machine, 20
Is a non-contact measuring device using a laser for dimension measurement.

In such a measuring system, for example, the distance to the object to be cut 1 is measured by the laser reflected light from the object to be cut 1, and the distance and the distance to the object to be cut 1 before cutting are measured. The cutting amount was calculated based on the difference.

[0004]

Since the conventional measuring system is configured as described above, the laser reflected light is affected by the cutting oil during cutting, and as a result, measurement cannot be performed during processing. However, there has been a problem that the workpiece 1 has to be removed from the cutting device after the machining to measure the dimensions.

The present invention has been made to solve the above problems, and an object thereof is to obtain a non-contact measuring device which is not affected by cutting oil and which can measure the size of a workpiece during machining. .

[0006]

A non-contact measuring device according to the present invention is an eddy current sensor for measuring a distance to an object to be cut, a mirror fixed to the eddy current sensor, and an object to be cut. Equipped with an optical length measuring device that measures the distance to the center and the distance to the mirror, and a calculation unit that calculates the dimensions of the workpiece based on the measured values of the eddy current sensor and the measured values of the optical length measuring device. It is a thing.

[0007]

The calculation unit in the present invention is such that the distance between the eddy current sensor and the object to be cut, the distance between the optical length measuring device and the mirror, and the distance between the optical length measuring device and the center of the cutting object. Calculate the dimensions of the work piece from the distance and the required constants.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is an object to be cut, 2 is a grindstone or cutting tool of a cutting machine, 3 is an eddy current sensor for measuring a distance Δx to the object 1, and 4 is a light for measuring a position of the eddy current sensor 3. The length measuring device, 5 is a mirror fixed to the eddy current sensor 3, 6 is a control unit (arithmetic unit) for controlling the movement of the microactuator 8 and the linear actuator 12, and calculating the size of the workpiece 1. It is a CRT that displays the calculation result of the control unit 6.

Reference numeral 8 is a microactuator for moving the eddy current type sensor 3 and the mirror 5 installed on the moving stage 9, and 10 is a microactuator mounting member. Further, 11 is a mounting base to which the moving stage 9 is mounted, and 12 is a linear actuator for moving the mounting base 11 via the slider 13.

Next, the operation will be described. First, before processing, etc., the eddy current sensor 3 and the mirror 5 are removed, and the distance L to the center of the workpiece 1 is measured by the optical length measuring device 4.
Is measured. The method of measuring the distance to the center of the workpiece 1 by the optical length measuring device 4 is a known technique. Then, the measured distance L is given to the control unit 6.

Next, the eddy current sensor 3 and the mirror 5
Is installed. Then, the control unit 6 drives the linear actuator 12 so that the moving stage 9 approaches the workpiece 1 according to the outer diameter of the workpiece 1 before processing. Next, the control unit 6 controls the microactuator 8 until the output voltage value of the eddy current sensor 3 reaches a value corresponding to the distance Δx = 0.5 mm from the eddy current sensor 3 to the outer circumference of the workpiece 1. To move the moving stage 9.

Further, the control unit 6 drives the microactuator 8 to move the moving stage 9,
Move away from the work piece 1 within the range of 0.1 to 0.3 mm. The control unit 6 samples the output voltage of the eddy current sensor 3 while the moving stage 9 is moving within that range. Then, the relationship between the distance and the voltage in the range, that is, the slope of the voltage change with respect to the distance change is calculated.

At this time, the object to be cut 1 is rotated and the output voltage for a certain distance is input a plurality of times, and the average value of the values of each output voltage is taken as the output voltage at that distance.
In this way, the error due to the deviation of the work 1 from the perfect circle can be eliminated. Then, the control unit 6 again moves the moving stage 9 to a position where Δx = 0.5 mm.

When the cutting process is started, the value of Δx becomes 0.
Since it increases from 5 mm, the output voltage value of the eddy current sensor 3 changes according to the increase. Therefore, the control unit 6 can obtain Δx at that time from the change in the output voltage value and the slope of the voltage change obtained in advance. Also, the tip of the eddy current sensor 3 and the mirror 5
The distance C between and is a fixed value. The control unit 6 causes the optical length measuring device 4 to measure the distance l to the mirror 5,
Introduce measurements. From each value obtained as above,
The control unit 6 calculates the size of the workpiece 1 by performing the following calculation.

D = 2X X = L- (C + 1 + Δx)

Then, the obtained dimensions are displayed on the CRT 7. Further, as the processing progresses, Δx becomes 0.5 mm + 0.
When it becomes larger than 3 mm and the slope of the voltage change obtained in advance cannot be used, the control unit 6 appropriately moves the moving stage 9. Also,
In response to this, the optical length measuring device 4 is caused to measure a new distance 1 to the mirror 5.

As described above, if the slope of the voltage change is obtained immediately before processing, the slope adapted to the ambient temperature can be obtained, and the error in the output voltage of the eddy current sensor 3 due to the ambient temperature can be removed. be able to.

[0018]

As described above, according to the present invention, the non-contact measuring device measures the distance to the object to be cut by the eddy current sensor and fixes the distance to the center of the object to be cut and the eddy current sensor. Since the distance to the position is configured to be measured by the optical length measuring device, there is an effect that the dimension of the workpiece can be measured during processing without being affected by the cutting oil.

[Brief description of drawings]

FIG. 1 is a block diagram showing a non-contact measuring device according to an embodiment of the present invention together with an object to be cut and the like.

FIG. 2 is a conceptual diagram showing a conventional workpiece measuring system.

[Explanation of symbols]

 1 Object to be cut 3 Eddy current sensor 4 Optical length measuring device 5 Mirror 8 Control unit (arithmetic unit)

Claims (1)

[Claims] 1. A non-contact measuring device for measuring the dimension of a work to be cut by a cutting machine in a non-contact manner, and an eddy current sensor for measuring a distance to the work, and an eddy current sensor Based on a fixed mirror, an optical length measuring device for measuring the distance to the center of the object to be cut and the distance to the mirror, and a measured value of the eddy current type sensor and a measured value of the optical length measuring device. A non-contact measuring device, comprising: an arithmetic unit that calculates the dimensions of the object to be cut.