JPS6256443B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for measuring the surface roughness of a rotating body for non-contact and in-process measurement of the surface roughness of a workpiece that is processed while rotating in a spinning process, etc. This is related to the device.

Conventionally, optical cutting methods and methods using optical fibers have been known as methods for measuring the surface roughness of rotating bodies in a non-contact and in-process manner.

In the former light cutting method, as shown in FIG. 1, a band-shaped light is irradiated onto the surface of a rotating body 1 from a light projection unit 2 obliquely from above, and a television camera 3 is placed in the direction of the reflection angle.
This method obtains a light-cut image corresponding to the unevenness of the surface of the rotating body 1, and then analyzes the light-cut image to measure the surface roughness. In this method, the resolution is up to about 1 μm. However, there are also drawbacks such as the need to place the measuring head close to the rotating body 1.

The latter method of using optical fibers involves dividing the optical fiber bundle 4 into a light-emitting fiber 4a and a light-receiving fiber 4b, as shown in FIG. A measuring head 5 configured in the form of The disadvantage is that it is large, measuring only a few ^mm2 , and cannot be analyzed in detail.

On the other hand, regarding the surface roughness of the rotating body, the results of experiments and analyzes conducted by the inventor of the present invention on the surface condition of the spinning workpiece after rough machining show that the surface roughness is as shown in Fig. 3. As shown in the figure, there are roll marks 8 caused by the cutting tool (or spatula marks when a spatula tool is used), streaks 9 caused by the slippage of the cutting tool, and crater-shaped depressions (hereinafter craters 10).
It has been confirmed that it consists of three elements:
In the case of the craters 10, they are scattered with their longitudinal direction perpendicular to the roll mesh 8, and their average dimensions are several hundred micrometers in the longitudinal direction and several tens of micrometers in the width direction.
It was confirmed that the diameter was on the order of μm.

Then, the surface roughness after the rough processing of the spinning process is reduced by the degree of each of the three roughness elements described above through the subsequent finishing process, and the roll lines 8 are eliminated and the lines 9 are only thin. It is considered that the number of craters 10 is reduced and the size is reduced, resulting in a quality product.

Therefore, an object of the present invention is to measure the surface roughness of a workpiece subjected to rotational processing in a non-contact manner by focusing on the fact that the surface roughness of a workpiece subjected to rotational processing such as spinning consists of the above three elements. It is an object of the present invention to provide a method and apparatus for measuring the surface roughness of a rotating body, which can measure the surface roughness of a rotating body with high precision in-process.

An embodiment of the method for measuring the surface roughness of a rotating body according to the present invention is shown in FIGS. 4 and 5. In other words, this method for measuring the surface roughness of a rotating body is based on the above-mentioned roll mesh, which constitutes the surface roughness of a workpiece in rotational processing.
Each of the three elements of streaks and craters is optically measured, and the degree of craters 10 (number, size, etc.) is measured by the process shown in FIG. (number, eye height, etc.)
This is done in the steps shown in the figure.

In the measurement of the crater 10, as shown in FIG. 4, a light beam projector 12 and a diffused light receiver 13 are arranged in a plane perpendicular to the rotation axis 11 of the workpiece 1 to be rotated. , light is emitted and received from the width direction of the crater 10 whose longitudinal direction is perpendicular to the roll eye 8 (therefore parallel to the rotation axis 11), and the amount of diffused light on the processing surface 1a of the workpiece 1 is calculated. It is used to measure

On the other hand, regarding the measurement of roll marks 8 and creases 9, as shown in FIG.
The light beam projector 12' and the light reflection position sensor 14 are disposed above a in a plane that includes the rotation axis 11 (therefore, a plane that extends in the diametrical direction of the workpiece 1), and the light beam Workpiece 1 from light projecting section 12'
A light beam is irradiated obliquely from above toward the processed surface 1a, the magnitude of the deflection displacement of the specularly reflected light by the roll eye 8 is detected by the light reflection position sensor 14, and the detection value of the roll eye 8 is detected by the light reflection position sensor 14. from the processing surface 1a of the workpiece 1 by the diffused light receiving section 13' disposed at an intermediate position between the light beam projecting section 12' and the light reflection position sensor 14. The degree of diffusion of the light beam irradiated from the light beam projector 12' due to the lines 9 on the processing surface 1a of the workpiece 1 is defined as the amount of received diffused light. Measured by
The degree of the streaks 9 is thereby measured.

FIGS. 6 and 7 are explanatory diagrams showing the principle of measuring the roll marks. When a light beam enters from the light beam projector 12' at an incident angle α with respect to the radial direction of the workpiece 1, If the processing surface 1a is flat, the light is reflected at a reflection angle α and enters the center of the light reflection position sensor 14. On the other hand, on the other hand, the machined surface 1
a is not flat and has a small angle θ with respect to the rotation axis direction
, the reflected ray is displaced by an angle 2θ. The light reflection position sensor 14 detects this displacement amount, and the displacement amount of the bright spot on the light reflection position sensor 14 is x, and the light reflection position sensor 1
4 and the light reflection point on the processed surface 1a is l
Then, as long as the angle θ is sufficiently small, the output x of the light reflection position sensor 14 is given by the following equation.

x=l·tan2θ≒2lθ By the way, when the uneven shape of the processed surface 1a in the radial direction is represented by the y coordinate as shown in FIG. 7, it becomes y=∫dy=∫θ·ds. Here, if the moving speed of the axial moving means that moves the tool in the direction of the rotation axis is v, then ds=
Since it can be expressed as v・dt, y=∫θ・ds=∫x/2l・vdt=v/2l∫x・dt. Therefore, if the distance l between the light reflection position sensor 14 and the light reflection point is constant, the variable y representing the radial position of the processing surface 1a is calculated by integrating the output x of the light reflection position sensor 14. , can be easily obtained by multiplying by the moving speed v of the axial moving means.

As the light beam, either a laser beam or white light may be used, but a laser beam is preferable in order to narrow down the beam diameter and improve measurement accuracy.

In this way, the surface roughness of the workpiece 1 to be rotationally machined is determined by three points: the roll stitches 8, the creases 9, and the craters 10.
Since it is divided into elements and each element is measured independently, the surface roughness can be quantitatively analyzed and highly accurate surface roughness measurement can be performed.

Measurement of streaks 9 and craters 10 can be carried out by measuring the amount of light in the same way as in conventional measurement systems, by simply adding conditions regarding the arrangement of the light emitting and receiving parts.
It is possible to use a general spot sensor,
The measurement system can be constructed easily and inexpensively.

In particular, when measuring the crater 10, the workpiece 1
The light is emitted and received in a direction perpendicular to the rotation axis 11 of the crater 10, that is, in a direction perpendicular to the longitudinal direction of the crater 10, and the extent of the crater 10 is measured from the intensity of the diffused light, which allows for greater detection. In addition, in the case of measuring the streaks 9, in which light is emitted and received in the direction of the rotation axis 11, and the directions of the light beam projection and reception are orthogonal to each other, the diffused light for the streak measurement is used for crater measurement. It is possible to effectively prevent the diffused light from entering the diffused light receiving section 13, and it is possible to perform measurements with even higher accuracy.

Further, the light emitting parts 12, 12', the light receiving parts 13, 13' for measuring the crater 10, the streaks 9, and the light reflection position sensor 14 for measuring the roll marks are all provided on the processing surface 1a of the workpiece 1. They can be placed approximately 100mm apart, allowing safe and accurate measurements without the inconvenience of shavings, oil, etc. scattering or getting caught in the measurement system.

Next, FIGS. 8 and 9 show an embodiment of a device for measuring the surface roughness of a rotating body, which has a simple structure and can efficiently carry out the method for measuring the surface roughness of a rotating body. In other words, this surface roughness measuring device for a rotating body measures the rotational axis 1 of the workpiece 1' to be rotatably machined.
1' (X-axis), a direction perpendicular to the rotation axis 11' (direction of advancing and retreating toward the workpiece 1', Y-axis), and a plane parallel to the plane formed by the X-axis and Y-axis. The rotation direction θ′ of rotation around the workpiece is
A measuring head mounting table 15 having three degrees of freedom and arranged near the machining surface 1'a of the workpiece 1', and a measuring head mounting table 15 provided on the measuring head mounting table 15 and oriented in the direction of the rotation axis 11'. a light beam projecting section 12'' that irradiates the processing surface 1'a with a light beam; It is installed on the measuring head mounting table 15 facing toward the direction ``a'', and receives the specularly reflected light from the processed surface 1'a of the light beam irradiated from the light beam projector 12'', and processes the specularly reflected light. A first light-receiving section 13''a that measures the height of the roll pattern on the processing surface 1'a from the deflection displacement, and a position located at an intermediate portion between the light beam projecting section 12'' and the light-receiving section 13''a. The light beam is provided on the measuring head mounting table 15 facing the processing surface 1'a, and is emitted from the light beam projecting section 12'', and the light beam is diffused by the streaks on the processing surface 1'a. a second light receiving section 13''b that receives light and measures the degree of the streaks (for example, the number of streaks) from the amount of received light; the light beam projecting section 12'' and the second light receiving section 13''b; The light beam projecting section 12'' is provided on the measurement head mounting table 15 facing the processing surface 1'a so as to be located in a plane substantially perpendicular to the plane containing the light beam.
a third light-receiving section 13''c that receives diffused light due to craters on the processed surface 1'a of the light beam irradiated from the processing surface 1'a and measures the extent of the craters (for example, the number of craters) from the amount of received light; The light beam projecting section 12'' includes an optical fiber 16.
The laser beam is connected to the laser generator 17 via the light beam projector 12'', and a laser beam is used as the light beam emitted from the light beam projector 12''.

The detection outputs of the light receiving sections 13''a, 13''b, and 13''c are processed as follows by the processing circuit shown in FIG.

In the light receiving section 13''a which receives the specularly reflected light from the processing surface 1'a, a detection output a proportional to the intensity of the specularly reflected light is obtained by photoelectric conversion, and this detection output a is sent to the next stage integrating circuit 18. The height of the roll grain is detected by performing the same integration process as in the case of measuring the roll grain in the direction of measuring the surface roughness of the rotating body.

The light receiving section 13''b that receives the diffused light caused by the streaks on the processed surface 1'a obtains a detection output b corresponding to the intensity of the diffused light, and this detection output b is used in the next stage division circuit 19 to calculate the received light. By dividing by the detection output a of the section 13''a, the amount of streaks on the processed surface 1'a is detected.

The light receiving section 13''c that receives the diffused light caused by the crater on the processed surface 1'a obtains a detection output c corresponding to the intensity of the diffused light, and this detection output c is divided by the dividing circuit 20 in the next stage as described above. Similarly, by dividing by the detection output a of the light receiving section 13''a, the amount of craters on the processed surface 1'a is detected.

As described above, the detection outputs b and c of the light receiving sections 13''b and 13''c are divided by the detection output a corresponding to the specularly reflected light intensity of the light receiving section 13''a. This is to make the detected values of a, 13''b, and 13''c dimensionless to avoid influences of changes in the amount of light from the light source and the reflectance of the processed surface from affecting the detection results.

Further, the detection output a of the light receiving section 13''a is separately received by an LP filter circuit 21, and is sent to the light receiving section 13''.
It is checked whether the measuring head mounting table 15 is positioned at an angle at which the specularly reflected light is correctly received by the measuring head mounting table 15, and based on this confirmation signal d, the processing surface of the measuring head mounting table 15 is The configuration is such that the angle relative to 1'a can be automatically corrected.

On the other hand, the light receiving section 13''b detects a light spot image projected on the processing surface 1'a by the light beam of the light beam projecting section 12'', and detects the light spot image projected on the processing surface 1'a and the measuring head mounting table 15 and the processing surface 1'a. The detection output b' corresponding to the light spot image is processed in another arithmetic circuit 22 to detect the distance, and this detection value e Based on the measurement head mounting table 1
5 is configured to automatically correct the distance to the processing surface 1'a to a predetermined value.

The measurement head mounting table 15 moves from one end of the workpiece 1' to the other end by three-axis NC drive of X, Y, and θ' while the workpiece 1' is rotating. The roll marks, streaks, and craters are measured.

Note that the NC of the measuring head mounting table 15 is
The driving trajectory can also be determined by teaching using the distance and angle measurement functions of the measurement head, and the distance and angle deviations from the basic trajectory can also be measured and fed back. It is also possible to adjust the distance and angle for each sample of processed material.

With this configuration, the following effects can be obtained.

(1) Three elements of surface roughness are combined into one light beam projector 1
2'' can be used in combination, the configuration can be simplified, and three measurements can be performed simultaneously and accurately without mutual interference, greatly improving measurement efficiency.

(2) The diameter of the light spot can be narrowed down to 0.1 to 0.5 mmφ, making it possible to perform precise surface roughness measurements.

(3) It is possible to measure the distance and angle of the measuring head to the machined surface by using each light receiving part separately from the original purpose.
There is no need to add a separate sensor for angle measurement, the measurement distance, angle deviation, etc. can be monitored with a simple configuration, and a teaching function can be easily added.

As described above, the method for measuring the surface roughness of a rotating body according to the present invention is such that the light beam projector and the light reflection position sensor are placed within a plane including the rotation axis of the workpiece to be rotatably processed. The light reflection position sensor receives the specularly reflected light of the light beam irradiated from the light beam projection unit toward the surface, and detects the deflection displacement of the specularly reflected light due to the roll of the processed surface. a roll eye measurement step of detecting the height of the roll eye with the light reflection position sensor, and directing a light beam projector and a diffused light receiver toward the processing surface within a plane including the rotation axis. a streak measuring step in which the diffused light from the streaks on the processed surface of the light beam irradiated from the light beam projector is received by the diffused light receiver and the degree of the streaks is measured based on the amount of received light; , a light beam projector and a diffused light receiver are disposed in a plane perpendicular to the rotation axis to face the processing surface, and the light beam irradiated from the light beam projector is caused by a crater on the processing surface. and a crater measuring step of receiving diffused light with the diffused light receiving section and measuring the extent of the crater based on the amount of received light,
The surface roughness of a workpiece to be rotatably machined can be measured with high accuracy in a non-contact and in-process manner. a light beam projecting section that irradiates a light beam onto the processing surface of the workpiece in the direction of the rotation axis of the workpiece; and a plane including the rotation axis and the light beam projecting section toward the processing surface. a first light receiving device disposed within the light beam projecting unit, which receives specularly reflected light from the light beam projecting section on the processing surface, and measures the height of the roll pattern on the processing surface from the deflection displacement of the specularly reflected light; and disposed toward the processing surface at an intermediate position between the light beam projecting section and the first light receiving section, and diffusing the light beam from the light beam projecting section by streaks on the processing surface. a second light receiving section that receives light and measures the degree of streaks on the processed surface from the amount of light received; and a plane that is substantially orthogonal to the plane that includes the light beam projecting section and the second light receiving section toward the processed surface. a third light receiving unit disposed in a plane where the light beam from the light beam projecting unit receives diffused light due to craters on the processed surface, and measures the degree of cratering on the processed surface from the amount of received light; a measurement head position adjustment table in which the measurement head including the light beam projector, first, second, and third light receivers is fixed and the position is freely adjustable at a position close to the processing surface of the workpiece; Therefore, it has the effect that the surface roughness of a workpiece can be efficiently measured by the above measurement method with a simple and compact configuration.

[Brief explanation of the drawing]

Figures 1 and 2 are perspective views showing a conventional example, Figure 3 is a partially enlarged perspective view showing the machined surface of a rotary machined workpiece, and Figures 4 and 5 are measurements of the present invention, respectively. FIGS. 6 and 7 are diagrams explaining the principle of the method, and FIGS. 8 and 9 are perspective views and processing circuit blocks showing an embodiment of the measuring device of the present invention, respectively. It is a diagram. 1, 1'... Work material, 1a, 1'a... Machining surface, 8... Roll stitch, 9... Line, 10... Crater, 11, 11'... Rotating shaft, 12, 12', 1
2''...Light beam projector, 13, 13'...Diffused light receiver, 13''a...Light receiver (light reflection position sensor), 13''b, 13''c...Light receiver, 14... Light reflection position sensor, 15... Measuring head mounting table, 16... Optical fiber, 17... Laser generator, 19, 20... Dividing circuit, 21... LP filter circuit, 22... Arithmetic circuit.

Claims (1)

[Scope of Claims] 1. A light beam projector and a light reflection position sensor are disposed in a plane including a rotation axis of a workpiece to be rotatably processed, and the light beam projector and a light reflection position sensor are arranged to face the processing surface of the workpiece, and The light reflection position sensor receives the specularly reflected light of the light beam irradiated from the processing surface on the processing surface, and the light reflection position sensor detects the deflection displacement of the specularly reflected light due to the roll of the processing surface. a roll grain measurement step of measuring the height of the roll grain, and arranging a light beam projector and a diffused light receiver facing the processing surface in a plane including the rotation axis;
a streak measuring step of receiving diffused light due to streaks on the processed surface of the light beam irradiated from the light beam projecting unit in the diffused light receiving unit and measuring the degree of the streaks based on the amount of received light; and the rotation. A light beam projecting section and a diffused light receiving section are arranged in a plane perpendicular to the axis to face the processing surface, and diffused light due to a crater on the processing surface of the light beam irradiated from the light beam projecting section is disposed. A method for measuring surface roughness of a rotating body, comprising a crater measuring step of receiving light at the diffused light receiving section and measuring the extent of the crater based on the amount of the received light. 2. A light beam projection unit that irradiates a light beam onto the processing surface of the workpiece in the direction of the rotation axis of the workpiece to be rotationally processed; The light beam is arranged in a plane including the light section, and receives the specularly reflected light of the light beam from the light beam projecting section on the processing surface, and from the deflection displacement of the specularly reflected light, the height of the roll eye of the processing surface is determined. a first light receiving section for measuring the processing surface; a second light receiving section that receives diffused light due to the streaks on the surface and measures the extent of the streaks on the processed surface from the amount of received light; the light beam projecting section and the second light receiving section that project the light beam toward the processed surface; is arranged in a plane substantially orthogonal to a plane containing the light beam, and receives diffused light from the light beam from the light beam projection unit due to craters on the processed surface, and measures the degree of cratering on the processed surface from the amount of received light. a third light receiving section;
a measurement head position adjustment table in which the measurement head including the light beam projector, first, second, and third light receivers is fixed and the position is freely adjustable at a position close to the processing surface of the workpiece; A surface roughness measurement device for rotating bodies. 3. The measurement head position adjustment table detects the position where the first light receiving section receives the specularly reflected light as an angular position where specular reflection occurs between the light beam projecting section and the first light receiving section, and determines the position. Correction control is performed to determine the position where the second light receiving section receives the light spot image projected on the processing surface by the light beam from the light beam projecting section, so that the distance between the processing surface and the measurement head is correct. The surface roughness measuring device for a rotating body according to claim 2, wherein the surface roughness measuring device for a rotating body is configured to detect the position and perform position correction control.