JPH0663756B2 - Surface shape measuring device for dull roll - Google Patents

Description

Detailed Description of the Invention

<Field of Industrial Application> The present invention relates to an apparatus for measuring the shape of a crater or the like that forms a rough surface on a roll that has been dull processed by a laser pulse beam. <Prior Art> Generally, work rolls used for rolling mills such as steel plates, stainless steel plates, and aluminum plates are roughly classified into bright rolls and dull rolls according to their peripheral surface configurations. The former is polished and finished, and the metal plate rolled by this roll has a gloss finish. On the other hand, the latter dull roll has irregularities on the surface by shot blasting or electric discharge machining, and the metal plate rolled by this has a satin finished surface. By the way, recently, a method of using a laser beam to manufacture a dull roll is drawing attention. This method, for example, as described in JP-A-55-94790, while rotating the roll to be processed, pulse the laser beam by a mechanical chopper, or generate a pulse beam electrically, By irradiating the roll surface with this pulse beam one after another, the roll surface is partially melted to provide unevenness. FIG. 4 and FIG. 5 schematically show the roll surface obtained by processing in this way. In the figure, 1
Is a crater formed by one pulse of a laser pulse beam, and 2 is a ring portion formed by rising of the base metal melted at this time. Incidentally, 4 is a flat portion where the surface of the roll 3 is left unprocessed. Further, in this case, the ring portion 2 can be eliminated by adjusting the processing conditions. The concavo-convex pattern on the surface formed in this way is characterized by being very regular, whereas that obtained by shot blasting or electrical discharge machining is random. The formed dull metal plate has various excellent properties. <Problems to be Solved by the Invention> Normally, when a roll is dull-processed by a laser pulse beam, the size of the craters and the distance between the craters are changed according to the type and application of the metal plate to be rolled. That is, the concavo-convex pattern on the surface is changed by adjusting the output of the laser beam and the irradiation time, or by controlling the rotation speed of the mechanical chopper, the rotation speed of the roll to be processed, and the like. However, there is no effective method for inspecting whether the concavo-convex pattern after processing has a predetermined shape, and it is particularly difficult to grasp the size of the crater. That is, the size of the crater is usually about 10 to 400 μm, and the pickup cannot be measured by the conventional mechanical surface roughness meter because the pickup is large. There is also an optical roughness meter,
Since the device is large and the surface of the roll cannot be observed directly, a replica is usually taken for measurement. Furthermore, while using an optical microscope to directly observe the roll surface, the rotation of the roll must be stopped during that time,
This is inefficient, and has a drawback that the load on the operator is large. The present invention has been made to solve the above problems, and an object of the present invention is to provide a surface shape measuring device that can directly and easily measure the surface shape of a dull roll processed by a laser beam. To do. <Means for Solving the Problems> The present invention is an apparatus for measuring the surface shape of a roll dull-processed by a laser pulse beam, the laser oscillator generating a laser pulse beam for measurement, A photoreceiver that receives the pulse beam that is irradiated on the roll surface and reflected, and outputs an electrical signal of a magnitude that corresponds to the amount of received light, and passes only the signals that are above a certain value among the signals output from this photoreceiver. A limiter, a waveform processing circuit for converting the passing signal into an analog signal, and a counter for counting the number of pulses of the laser pulse oscillator or the number of pulses generated from a separately provided pulse oscillator based on the output signal from the waveform processing circuit. And a calculation device that calculates the surface shape of the roll based on the number of pulses counted by this counter. It is dull for the surface shape measuring apparatus according to claim. <Operation> The present invention irradiates the roll surface with a laser pulse beam, converts the intensity of this reflected light into an electric signal, and considers that a small electric signal is a signal corresponding to the crater portion and cuts it. Therefore, it is possible to automatically and easily measure the size of the crater and further the size of the flat portion. <Examples> Examples of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an explanatory view schematically showing an embodiment of the device of the present invention. In the figure, reference numeral 5 denotes a laser pulse oscillator, and the pulse beam a is applied to the surface of the roll 3 at an incident angle θ. During this time, since the roll 3 is rotating in the F direction indicated by the arrow, the laser beam a is directed in the circumferential direction of the roll 3 (for example, the A direction in FIG. 4).
Will be scanned. Reference numeral 6 denotes a photodetector for detecting the reflected pulse beam c reflected on the roll surface, and outputs an electric signal d having a magnitude proportional to the amount of received light. The light receiver 6 is provided so as to have the same light receiving angle θ as the incident angle θ of the pulse beam a. A limiter 7 cuts a small pulse signal of the signals output from the light receiver 6 and passes only a large pulse signal as e.
Reference numeral 8 denotes a waveform processing circuit, the output signal f of which is input to the up counter 10. The pulse signal b from the laser pulse oscillator 5 is input to the up counter 10. And this up counter 10
Is input to the calculator 9, the size of the crater is calculated based on the signal g, and the result is output as the signal h. In the above configuration, the output pattern of the laser beam emitted from the laser pulse oscillator 5 is as shown in FIG. 2 (a), and the signal b obtained by extracting the control signal for electrically generating the pulse beam has the same waveform. Becomes The laser beam a applied to the surface of the roll 3 is reflected by the surface of the roll 3, and the reflected pulse beam c is detected by the light receiver 6. The roll 3 is polished and then irradiated with a laser beam to form the crater 1. Therefore, the reflectance of the flat portion 4 is very high, whereas the surface of the crater 1 is oxidized. Also, because it is not flat,
The amount of light received by the light receiver 6 decreases, and the signal pattern becomes as shown in FIG. This received signal is converted into an electric signal d, and this pattern is also the same as in FIG. 2 (b). The low output signal of this electric signal d is cut by the limiter 7, and becomes a signal e having the pattern shown in FIG. 2 (c). Next, the signal e is converted by the waveform processing circuit 8 into the signal f having the pattern shown in FIG. The signal f is input to the up counter 10, and the up counter 10 starts counting the number of pulses of the pulse signal b output from the oscillator 5 when the signal f becomes zero. Next, when the output from the waveform processing circuit 8 is reached, the counting is finished, and the result is output to the calculator 9 as a count signal g, and at the same time, the up counter 10 is reset to prepare for the next count. In the computing unit 9, the count signal g from the up counter 10
Calculate the size of the crater based on
It can be output to a CRT, a printer or the like, or can be output to a laser dull processing machine and used as a feedback signal. Now, assuming that the peripheral speed of the roll 3 is v (mm / sec), the time per pulse is T (sec), and the number counted by the up counter 10 is n (pulse), the diameter of the crater 1 is D (m
m) is calculated by the following formula. The size of the ring portion 2 is also included in the crater here. D = T · n · v (1) Further, if the width of the ring portion 2 is B (mm) (see FIG. 5), there is a relation of B ≈ 0.15 D ...... (2) and the crater When the depth of 1 is H (mm) (see FIG. 5), it is known that the depth H and the diameter D have a relationship as shown in FIG. Therefore, if the diameter D of the crater is known from the equation (1), the shape of the crater can be grasped. Although the counting pulse signal b is taken out from the control signal of the laser pulse oscillator 5 in the above-mentioned embodiment, the present invention is not limited to this, and a pulse oscillator may be provided independently. It is effective for pulsing with a mechanical chopper. Further, in the above embodiment, the case where the diameter of the crater is measured has been described, but it is also possible to measure the size of the flat portion. However, in this case, it is necessary to reversely use the pattern shown in FIG. 2D as the trigger signal for starting the pulse count. That is, the count is started when the output is output, and the count is ended when the output becomes zero. Further, as the measurement laser beam, a part of the laser beam for dull processing may be extracted and used. <Effects of the Invention> As described above, according to the present invention, it is possible to easily measure the surface shape of a dull-processed roll by using a laser pulse beam, and it is also possible to achieve automation of measurement. It can greatly contribute to product quality assurance.

[Brief description of drawings]

FIG. 1 is an explanatory view schematically showing an embodiment of the device of the present invention,
FIG. 2 is a characteristic diagram showing each signal pattern, FIG. 3 is a characteristic diagram showing the relationship between the diameter and depth of the crater, FIG. 4 is a plan view schematically showing the roll surface, and FIG. FIG. 3 is a cross-sectional view schematically showing the roll surface. 1 ... Crater, 2 ... Ring part, 3 ... Roll, 4 ... Flat part, 5 ... Laser pulse oscillator, 6 ... Photoreceiver, 7 ... Limiter, 8 ... Waveform processing circuit, 9 ... Calculator, 10 ... Up counter.

Claims (1)

[Claims] 1. An apparatus for measuring a surface shape of a roll dull-processed by a laser pulse beam, comprising: a laser oscillator for generating a laser pulse beam for measurement; and a pulse emitted from the oscillator and reflected by the roll surface. An optical receiver that receives the beam and outputs an electrical signal of a magnitude corresponding to the amount of received light, a limiter that allows only signals above a certain value among the signals output from this optical receiver to pass, and an analog signal that passes this signal. A waveform processing circuit for converting to a pulse processing circuit, a counter for counting the number of pulses of the laser pulse oscillator or the number of pulses generated by a pulse oscillator provided separately based on the output signal from the waveform processing circuit, and the pulse counted by this counter. A dull roll characterized by comprising an arithmetic unit for calculating the surface shape of the roll based on the number. Profilometer.