JPH04291138A - Marking device for flaw portion on strip - Google Patents

Abstract

PURPOSE:To enable a portion with flaw to be identified easily when inspecting it again. CONSTITUTION:A title item consists of a flaw detection device 6 for detecting a flaw on a strip surface based on an amount of voltage which is obtained by scanning the strip surface with laser beam and then receiving a reflection light with a photoelectric conversion element a tracking device 11 for tracking a travel of any position in length direction of the strip based on a peripheral speed of a strip transport roller, and a marking device 12 for performing marking on the portion with flaw on the strip which is obtained from the flaw data from the flaw detection device and the flaw position traveling data from the tracking device. Since a mark is given to the portion with flaw on the strip, a purchaser of a material can find the portion with flaw easily when uncoiling it.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting flaws on the surface of a steel strip manufactured by cold rolling and marking the flawed areas.

0002

2. Description of the Related Art Steel plate strips produced by cold rolling are inspected for defects over almost the entire surface to ensure quality. This strip surface inspection method involves scanning the strip surface running in a line in the width direction with a laser beam, converting the reflected waves into voltage intensity using a photoelectric conversion element such as a CCD element, and converting this signal data into voltage intensity. A method for determining the presence or absence of flaws has already been established (see Japanese Patent Laid-Open No. 63-62825, etc.).

[0003] On the other hand, the results of such inspection are generally presented to the purchaser in writing, and the nature, size, and location of flaws are also usually indicated on the document.

0004

[Problem to be Solved by the Invention] Therefore, the purchaser of the strip material needs to reconfirm the actual product by comparing it with the data on the document, which is not only troublesome, but may also cause defects. There was also a risk that the information would be processed without being overlooked.

[0005] The present invention was devised to solve the above-mentioned disadvantages of the prior art, and its main purpose is to enable easy identification of defective parts when re-inspecting them. An object of the present invention is to provide a defect marking device for marking a defective part.

[0006]

[Means for solving the problem] This purpose is to scan the strip surface with a laser beam, and detect the flaws on the strip surface based on the voltage intensity obtained by receiving the reflected light with a photoelectric conversion element. A flaw detection device for detecting flaws, a tracking device for tracking the movement of any position in the length direction of the strip based on the circumferential speed of the strip conveyance roller, and flaw data from the flaw detection device and flaw data from the tracking device. This is achieved by a marking device for marking a flawed portion of a strip, which is characterized in that it comprises a marking device for marking a flawed portion on the strip obtained from flaw position movement data.

[0007]

[Operation] According to this device, the flawed area detected by the flaw detection device is tracked by the tracking device, and paint or the like is applied to the flawed area at an appropriate position during the process to clearly identify the flawed area. Markings can be applied.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below based on specific embodiments shown in the accompanying drawings.

FIG. 1 shows the overall configuration of the apparatus of the present invention. This device is a He-Ne laser projector 1 that sweeps a laser spot toward the surface of a strip 2 in the width direction, and the reflected light is received by a light receiver 3 consisting of a photomultiplier or the like. A voltage intensity signal is processed by a processing device 4, and a strip 2 is generated from this voltage waveform or a differential waveform obtained by differentiating this voltage waveform.
A flaw detection device 6 configured to detect flaws on the surface of the strip and display them as a grayscale image on a CRT screen 5 and a pulse generator 8 count the number of revolutions of a hearth roll 7 that conveys the strip 2. , the feeding amount of the strip 2 is calculated from the plate speed calculated by the calculator 9 and the reference position for each coil obtained by detecting the punch hole provided in the welded part of dissimilar materials with the phototube 10. and a marking device 12 for spraying paint or the like onto the flawed portion of the strip 2 obtained from the flaw detection data from the flaw detection device 6 and the strip feed amount data from the tracking device 11. , a centralized control panel 13 that aggregates data from each device and performs integrated control of each device.
It consists of

First, the voltage waveform or differential waveform obtained from the voltage intensity signal emitted by the light receiver 3 is compared with a predetermined tolerance value, and if a signal exceeding the tolerance value is input to the processing device 4, an alarm is issued. At the same time, the still images are sequentially stored in the digital memory and displayed on the CRT screen 5. At the same time, this flaw occurrence signal and the flaw position are output to the central control panel 13.

[0011] On the other hand, the operator should
The image on the screen 5 is visually judged, and if it is determined that there is a harmful defect, a defect determination signal is outputted to the central control panel 13 by pressing buttons 14 or the like.

On the other hand, an arbitrary position on the strip 2 is tracked based on the feed length of the strip 2 obtained from the number of revolutions of the hearth roll 7. Then, the flaw position where the harmful flaw determination signal has been emitted is tracked, and an activation signal is emitted from the central control panel 13 to the marking device 12 in synchronization with the movement of the flaw. Incidentally, since the coils for each customer are sometimes welded at the middle part, a punch hole in the welded part is detected by the phototube 10, and this is used as a position reference for each coil.

[0013]The paint is then sprayed onto the flawed portion in synchronization with the timing at which the flaw determined to be harmful passes the installation position of the marking device 12. At the same time, the flaw data is input to the external storage device 15, printed out and attached to the inspection report, or saved as verification data.

In this way, the material coiled again into the coil 16 has a clear mark at the location of the flaw, so if the purchaser of the material coil uncoils it during processing, it is easy to check the presence or absence of flaws. This means that it can be determined.

[0015] In the above embodiment, the operator's judgment is involved in determining harmful defects, but complete automation is also possible depending on the accuracy of defect detection or the setting of threshold values.

[0016]

As described above, according to the present invention, the position of the flawed part on the strip can be tracked and marked at that position, so that the purchaser of the material can easily track the position of the flawed part on the strip. Defects can be easily discovered. Therefore, when removing defective parts, unnecessary burdens are not imposed on the purchaser, and the effect is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a defect marking device based on the present invention.

[Explanation of symbols]

1 Floodlight 2 Strip 3 Photo receiver 4 Processing equipment 5 CRT screen 6 Flaw detection device 7 Hearth roll 8 Pulse transmitter 9 Arithmetic unit 10 Phototube 11 Tracking device 12 Marking device 13. Centralized control panel 14 Push button 15 External storage device 16 Coil

Claims (1)

[Claims] Claim 1: Scanning the strip surface with a laser beam,
A flaw detection device for detecting flaws on the strip surface based on the voltage intensity obtained by receiving the reflected light with a photoelectric conversion element, and a flaw detection device for detecting flaws in the strip length direction based on the circumferential speed of the strip conveyance roller. a tracking device for tracking movement of the position of the strip; and a marking device for marking a flawed portion on the strip obtained from flaw data from the flaw detection device and flaw position movement data from the tracking device. A device for marking a defective part of a strip, comprising: