JP2003232616A - Optical displacement sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical displacement sensor capable of detecting three- dimensional displacement without limiting the attached position. <P>SOLUTION: The laser beams L emitted from a light emitting part 11 for emitting light beams are received at a light receiving part 12, and made to come in a CCD camera 16 through an optical fiber strand 13 to produce image data. When the image data are produced, the three-dimensional displacement of the light receiving part 12 is detected based on the image data corresponding to the peripheral edge part with relatively small intensity of light in the produced image data, and data for machining the work W by a machine tool 3 is corrected according to the displacement. Accordingly, an NC device 2 outputs the corrected data to the machine tool 3 to machine the work W. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical displacement sensor that optically detects displacement.

[0002]

2. Description of the Related Art In the case of an NC machine tool, for example, the base mold itself, which is the structure of the machine tool, may expand or contract depending on weather conditions such as temperature, humidity, and atmospheric pressure. However, if the base die itself of the NC machine tool for precision machining expands or contracts even a slight amount, the finish accuracy of the work (workpiece) is deteriorated. Therefore, conventionally, as shown in FIG. 4, by mounting the contact type distance sensor 54 so as to directly contact the machining tool mounting portion 52 of the NC machine tool 51 and the workpiece mounting table 53, the machining tool mounting portion 52 and the workpiece are mounted. The work W is machined after measuring the distance between the mounting tables 53 and artificially correcting the NC data (machining data) based on the measured distance. This suppresses the deterioration of the finish accuracy of the work W due to the expansion or contraction of the base die 51a of the NC machine tool 51.

[0003]

As described above, the contact type distance sensor 54 is used for the work tool mounting portion 52 of the NC machine tool 51.
The vertical distance between the workpiece mounting table 53 and the workpiece mounting table 53 is measured, and the NC data (processing data) is artificially corrected based on the measured distance, and then the workpiece W is machined. The reduction in the finishing accuracy of the work W due to the expansion or contraction of the base die 51a is suppressed. However, when the base mold itself, which is the structure of the machine tool, expands or contracts due to weather conditions such as temperature, humidity, and atmospheric pressure, the processing tool mounting portion 52 and the work mounting table 5
Not only does the vertical distance between 3 change, but so does the horizontal distance. That is, it has been confirmed that the workpiece mounting table 53 is displaced three-dimensionally with respect to the processing tool mounting portion 52. Therefore, the processing tool mounting portion 52 and the work placement table 53
It is not possible to sufficiently suppress the deterioration of the finishing accuracy of the work W only by detecting the vertical distance between the two. Further, since it is necessary to mount the contact type distance sensor 54 so as to make contact with the work tool mounting portion 52 and the work mounting table 53, the contact type distance sensor 54 occupies a part of the work mounting table 53, and the work mounting table 53 is mounted. The usable area of the table 53 is reduced. As a result, the shape and placement of the work W are limited, and the workability of the NC machine tool 51 is reduced.

Therefore, it is an object of the present invention to provide an optical displacement sensor capable of detecting displacement three-dimensionally and having a degree of freedom in mounting position.

[0005]

The above-mentioned problems can be solved by the optical displacement sensor described in the section of the claims.

According to the optical displacement sensor of the first aspect, when the light emitted from the light emitting portion that emits a beam of light is collected by the light collecting portion, the image data generating means is collected by the light collecting portion. Generates and stores the image data of the light. Then, the displacement detecting means three-dimensionally detects the displacement of the daylighting section based on the image data corresponding to the peripheral portion of the light that is collected by the daylighting section and has a relatively low light intensity. In this case, since the displacement of the daylighting part is detected based on the image data corresponding to the peripheral part of the light that is relatively light intensity of the daylighting part, it is possible to detect this even if the displacement is minute. I can. Also, since it is possible to install the light emitting part and the daylighting part separately, there is flexibility in the mounting position,
The mounting position is not limited.

According to the optical displacement sensor of the second aspect, the displacement of the lighting part is three-dimensionally detected by mounting the light emitting part and the lighting part in the vicinity of the work tool mounting part and the work disposing part of the machine tool. In addition, since the machining data for machining a workpiece by the machine tool can be corrected according to this detected displacement, the structure of the machine tool expands or contracts due to weather conditions such as temperature, humidity, and atmospheric pressure. The machining data can be automatically corrected even if the tool mounting portion and the work placement portion are relatively three-dimensionally displaced.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described. FIG. 1 shows the optical displacement sensor 1 of the present invention
It is a control block diagram showing the whole optical displacement sensor 1 composition when applied to machine tool 3 controlled by C device 2. Generally, in the machine tool 3, the base die 3a, which is a structure, may expand or contract depending on weather conditions such as temperature, humidity, and atmospheric pressure. In this way, the base mold 3a
When is expanded or contracted, the work placement table 3c is relatively displaced with respect to the work tool mounting portion 3b of the machine tool 3, so that the finish accuracy of the work (workpiece) W is deteriorated. Therefore, the optical displacement sensor 1 shown in FIG. 1 detects the displacement of the work placement table 3c of the machine tool 3 and corrects the machining data output from the NC device 2 in accordance with the detected displacement. It is used to prevent the finish accuracy of the workpiece W from being lowered due to the base mold 3a expanding or contracting due to weather conditions such as temperature, humidity, and atmospheric pressure.

As shown in FIG. 1, the optical displacement sensor 1 is mounted in the vicinity of the processing tool mounting portion 3b of the machine tool 3 and emits a laser beam L.
Mounted near the workpiece mounting table 3c of the light emitting unit 11
A light collecting section 12 for collecting the laser light L emitted from
The optical fiber bundle 13 for transmitting the laser light L collected by the light collecting unit 12 and the laser light L transmitted by the optical fiber bundle 13 are made incident to generate image data of the laser light L, and the image data is added to the image data. Based on the three-dimensional detection of the relative displacement of the lighting unit 12 with respect to the light emitting unit 11, correction data for correcting the machining data output from the NC device 2 to the machine tool 3 corresponding to the detected displacement. And a control unit 14 for outputting.
The configuration of the control unit 14 will be described later.

When it is assumed that the emission intensity of the laser beam L emitted from the light emitting section 11 is constant, when the workpiece mounting table 3c is relatively displaced with respect to the processing tool mounting section 3b, it corresponds to the displacement. As a result, the light intensity distribution in the daylighting section 12 also changes.

The emission intensity of the laser light L emitted from the light emitting section 11 is controlled by a control signal output from the laser output control interface 15 of the control unit 14. Further, in the daylighting section 12, the end faces of the above-described optical fiber bundle 13, that is, the light-collecting ports of the respective optical fibers are closely arranged in a horizontal plane.

FIG. 2 schematically shows the light intensity distribution of the laser light L collected by the daylighting section 12 in a three-dimensional shape, and FIG. 3 shows the light intensity distribution of the laser light L in the daylighting section 12. It is shown in a plan view, and represents that the light intensity at the center is the highest and becomes smaller toward the periphery.

The laser light L collected at the light-collecting port of each optical fiber of the optical fiber bundle 13 passes through the optical fiber bundle 13 and enters the CCD camera 16 provided in the control unit 14 from each light-emitting port to receive the light. To be done. Since the light output ports of the respective optical fibers of the optical fiber bundle 13 are arranged in a plane parallel to the light receiving surface of the CCD camera 16, the light emitted from the light output ports of the respective optical fibers is the light receiving surface of the CCD camera 16. Is incident at a right angle to. The CCD camera 16 functions as an image sensor, and generates image data of the laser light L incident on the light receiving surface of the CCD camera 16 at a right angle and stores the image data in the video RAM 17. The image data of the laser light L stored in the video RAM 17 corresponds to the light intensity distribution as shown in FIG. In addition, in FIG.
A block composed of the CCD camera 16 and the video RAM 17 is described as an image data generation unit 18.

A computer 19 is built in the control unit 14. This computer 19 has a video RAM 1
A displacement calculation software program for calculating the displacement of the daylighting section 12 based on the image data of the laser light L stored in FIG. When the computer 19 executes the displacement calculation software program, the three-dimensional displacement of the daylighting unit 12 is detected based on the peripheral edge image data corresponding to the peripheral edge ID of the light intensity distribution as shown in FIG. The reason for this is that since the central portion of the image data has large light intensity, there is little change in the image data corresponding to the displacement, whereas the peripheral portion I
This is because the image data of D has a small light intensity, and thus the change of the image data corresponding to the displacement is clear even if the displacement is minute. Before starting the machining of the workpiece W, the lighting unit 12 is set in a state in which the machining tool mounting portion 3b and the workpiece mounting table 3c of the machine tool 3 are set at predetermined positions.
When the computer 19 executes the displacement calculation software program, the image data of the laser light L that has been lit in step S1 is stored in the video RAM 17 as reference image data in advance, and when the computer 19 executes the displacement calculation software program, the video RAM 1
7, the displacement of the daylighting section 12 is calculated based on the comparison between the image data stored and the reference image data. The displacement calculation software program is a software program 20a for converting a change in each image data with respect to the reference image data into a "lateral deviation" of the lighting unit 12, and this "lateral deviation" is a "deviation angle".
The software program 20b for converting into "the shift angle", the software program 20c for calculating the "horizontal shift" from the "shift angle", and the software program 20d for calculating the "vertical shift" from the "shift angle". Have.

Further, the computer 19 uses the above-described displacement calculation software program to obtain the daylighting section 1 obtained.
The three-dimensional displacement of 2, that is, the above-mentioned NC device 2 corresponding to the “horizontal displacement” and “vertical displacement” of the daylighting unit 12.
Laser light for adjusting the intensity of the laser light emitted from the light emitting unit 11 while having a correction value calculation software program 21 for calculating and outputting the correction data for correcting the machining data output from the machine tool 3 from It has a laser light adjustment software program 22 for outputting the emission intensity adjustment signal to the above-mentioned laser output control interface 15.

Correction value calculation software program 2
1 outputs the calculated correction data to the NC device interface 23. Since the NC device interface 23 outputs the correction data to the NC device 2 described above, the NC device 2 corrects the machining data output to the machine tool 3. As a result, even if the work placement table 3c is three-dimensionally displaced due to the base mold 3a of the machine tool 3 expanding or contracting due to weather conditions such as temperature, humidity, and atmospheric pressure, the displacement can be dealt with. Since the processing data can be corrected, the work W can be processed as designed.

Next, the operation of the optical displacement sensor 1 incorporated in the machine tool 3 will be described. For convenience of explanation, it is assumed that the processing tool for processing the work W is attached to the processing tool attachment portion 3b of the machine tool 3 and the above-mentioned "initial setting" is completed.

Before the processing of the work W is started, the laser light L emitted from the light emitting portion 11 is collected by the light collecting portion 12 and is incident on the light receiving surface of the CCD camera 16 through the optical fiber bundle 13. Image data of the laser light L is generated, and the image data is stored in the video RAM 17. When the image data is stored in the video RAM 17 in this way, the computer 19 executes the above-described displacement calculation software program to detect the displacement of the daylighting unit 12, and then based on the detected displacement data, the correction value calculation software. The wear program 21 is executed.

When the correction value calculation software program 21 is executed and the above-mentioned processed data is corrected based on the data corresponding to the displacement of the daylighting section 12, the corrected processed data is passed through the above-mentioned NC device interface 23. N
C device 2 transmits.

The NC device 2 corrects the initially set machining data and outputs the corrected machining data to the machine tool 3. As a result, the base mold 3a of the machine tool 3 expands or contracts, so that the finish accuracy of the work W is compensated even if the work placement table 3c is displaced three-dimensionally.

As described above, the optical displacement sensor 1
Attaches the light emitting part 11 to the vicinity of the processing tool attachment part 3b of the machine tool 3 and attaches the lighting part 12 to the work table 3 of the machine tool 3.
By installing in the vicinity of c, the control unit 14
Since the displacement of the work mounting table 3c can be detected, the mounting position has a degree of freedom, and the workability of the machine tool 3 is not deteriorated. The light emitting unit 11 and the daylighting unit 12 may be attached at opposite positions.

Although the optical displacement sensor 1 incorporated in the machine tool 3 has been described in the above embodiment, the sensor is not limited to the machine tool 3 shown in FIG. 1 and may be used in other types of machine tools. Alternatively, it can be applied to the case of detecting the displacement of equipment other than the machine tool.

[0023]

According to the present invention, the displacement can be detected three-dimensionally, and the mounting position has a degree of freedom.

[Brief description of drawings]

FIG. 1 is a control block diagram showing an overall configuration of an optical displacement sensor.

FIG. 2 is a diagram illustrating the operation of the optical displacement sensor.

FIG. 3 is a diagram illustrating the operation of the optical displacement sensor.

FIG. 4 is an explanatory diagram for explaining a conventional technique.

[Explanation of symbols]

1 Optical displacement sensor 2 NC device 3 machine tools 11 Light emitting part 12 Daylight 13 Optical fiber bundle 14 Control unit 16 CCD camera 17 Video Ram 18 Image data generator 19 computers

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasumasa Okamoto             4-15 Kita-cho, Minami-ku, Nagoya-shi, Aichi             Union Electronics Co., Ltd. F term (reference) 2F065 AA01 AA06 AA07 AA19 AA20                       BB05 CC10 DD02 EE02 FF04                       FF23 FF61 GG04 HH02 HH04                       HH13 JJ03 JJ09 JJ26 LL01                       NN01 NN17 PP03 PP12 QQ24                       QQ25 QQ28 QQ31 RR09 TT08                 3C029 EE02 EE20

Claims (2)

[Claims] 1. A light emitting unit that emits light in the form of a beam, a light collecting unit that collects the light emitted from the light emitting unit, and image data of the light that is collected by the light collecting unit is generated and stored. An optical displacement sensor, comprising: an image data generation unit; and a displacement detection unit that detects a displacement of the daylighting unit based on image data corresponding to a peripheral portion of the light that is illuminated by the daylighting unit. . 2. The displacement of the lighting part is detected by mounting the light emitting part and the lighting part in the vicinity of the work tool mounting part and the work disposing part of the machine tool, and the machine tool corresponding to the detected displacement. The optical displacement sensor according to claim 1, further comprising a unit that corrects machining data for machining a workpiece according to.