JP2002148201A - Surface-inspecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely detect defects and abnormalities of steel plate surfaces. SOLUTION: In a hot rolling process of manufacturing the steel plate by a hot rolling mill, there are provided a surface detector 5 for optically detecting the steel plate surface, an image signal-extracting part 81 for extracting image data of the steel plate surface, and defects and positions of the defects when the steel plate surface includes defects on the basis of detection signals optically detected by the surface detector, a scroll process part 85 for carrying out a scroll process so as to display image data extracted by the image signal- extracting means at a velocity lower than a flow velocity of the steel plate, a defect mark-generating part 87 for generating marks to be attached to defect positions when the defects of the steel plate surface are detected by the image signal-extracting means 81, and a display process part 88 for executing a necessary process for displaying image data subjected to the scroll process by the scroll process part 85 and marks generated by the defect mark-generating part 87, and outputting the image data and the marks to a display device 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface inspection apparatus capable of displaying an image of a surface of a steel plate optically collected while rolling the steel plate at a speed lower than the actual flow speed of the steel plate in a hot rolling process.

[0002]

BACKGROUND OF THE INVENTION In the hot rolling process, iron, copper,
A metal slab of aluminum or the like is heated, and this is hot-rolled by a roughing mill and a finishing mill having a plurality of rolling rolls to produce a steel sheet having a constant thickness, and the steel sheet is wound into a coil by a winder. taking it.

Meanwhile, various defects appear on the surface of the steel sheet due to segregation of impurities in the material itself, flaws generated during rolling, and the like.

Conventionally, defects such as flaws on the surface of a steel sheet generated in the process of manufacturing a hot-rolled steel sheet are visually inspected while unwinding a hot-rolled coil. The type and degree of the defect are determined.

However, such a visual inspection of the surface of a steel sheet requires a great deal of labor and time. Therefore, recently, for example, as disclosed in Japanese Patent Application Laid-Open No. 6-102195, a light source, a line sensor camera, An application of a surface inspection device including a filter for removing self-emission from a steel plate has been considered.

FIG. 5 shows the structure of the surface inspection apparatus disclosed in the above publication.

In FIG. 5, a steel plate 22 flowing in the direction of arrow A is shown.
A lamp 24, which is turned on by a light source power supply 30, is disposed above the light source. A filter 32 is provided for removing the scattered light scattered by a portion 22a of the steel plate 22 irradiated with light from the lamp 24. The signal is detected by the line sensor camera 26, the detection signal is converted into a digital signal by the A / D converter 34, and the output signal is processed by the signal processor 36 for defect extraction. The image processing required for display is performed on the display device 40.

[0008]

However, in the hot rolling process, the flow speed of the hot-rolled steel sheet is 100 to 180.
Due to the high speed of 0 mpm, even if images of the steel plate surface are collected by the surface inspection device as described above and the collected images are displayed on a display device in real time, defects and abnormalities on the steel plate surface can hardly be found. .

Although an apparatus for cutting out and displaying only a defective portion or a defect candidate has been put to practical use, there are defects that cannot be sufficiently detected by such partial display. The defects include not only point-like defects but also, for example, defects that are thinly generated over the entire width direction of the steel sheet due to vibration of a roll. In order to detect such a defect, it is necessary to perform comparison with a background portion in a wide range, and it is necessary to display an image of the entire steel plate to an operator.

The present invention has been made in view of the above circumstances, and displays an image of the surface of a steel sheet optically collected while rolling the steel sheet at a speed lower than the actual flow speed of the steel sheet. An object of the present invention is to provide a surface inspection device capable of reliably and easily finding a defect or an abnormality on a surface.

[0011]

According to the present invention, in order to achieve the above object, a surface inspection apparatus is constituted by the following means.

In a hot rolling process for producing a steel sheet by a hot rolling mill, a surface detector for optically detecting the surface of the steel sheet, and an optical sensor for optically detecting the surface of the steel sheet. Based on the detected detection signal, image data of the steel sheet surface and an image signal extracting means for extracting a defect and its position when there is a defect on the steel sheet surface, and image data extracted by the image signal extracting means, Scroll processing means for performing scroll processing for display at a speed lower than the flow speed; and defect mark generating means for generating a mark to be attached to a defect position on the image data when a defect on the steel sheet surface is extracted by the image signal extracting means. And performing processing necessary for displaying the image data scrolled by the scroll processing means and the mark generated by the defect mark generation means. And a display processing means for outputting to the shown device.

According to a second aspect of the present invention, in the surface inspection apparatus according to the first aspect of the present invention, the surface of the steel sheet displayed on the display device in association with the image data scrolled by the scroll processing means is provided. Scale generation means for generating a scale indicating an image position is provided.

According to a third aspect of the present invention, in the surface inspection apparatus according to the first aspect of the present invention, the defect mark generating means includes a defect on the surface of the steel plate displayed on the screen of the display device according to the type or degree of the defect. The position, the shape, or the color of the mark attached to the portion is changed.

According to a fourth aspect of the present invention, in the surface inspection apparatus according to the first aspect of the present invention, when a defect on the surface of the steel sheet is extracted by the image signal extracting means, an alarm by sound, light or vibration is output. An alarm output means is provided.

According to a fifth aspect of the present invention, in the surface inspection apparatus of the fourth aspect of the present invention, the alarm output means changes an alarm state depending on the type or degree of the defect.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the surface inspection apparatus according to the present invention.

In FIG. 1, reference numeral 2 denotes a final rolling roll of a finishing rolling mill which hot-rolls a steel sheet 1 from a rough rolling mill (not shown) to a thickness of about 3 to 1 mm using a plurality of rolling rolls. Reference numeral 3 denotes a table roll for feeding the steel sheet 1 rolled to a predetermined thickness by a finishing mill to a winder 4.

In such a hot rolling process, a surface detector 5 for detecting the front side of the steel sheet 1 is disposed at an appropriate position downstream of the final rolling roll 2 of the finishing mill.

The surface detector 5 includes a light source lamp 5a comprising a light source lamp, a light projector for irradiating the steel sheet 1 with light guided from the light source lamp through the bundle fiber, and a line sensor for receiving reflected light from the steel sheet 1 through a filter. The optical system includes a camera 5b.

Further, reference numeral 6 denotes a steel sheet 1 to be wound by the winder 4.
Is a pulse detector provided on the final rolling roll 2 of the finishing mill, for example. A pulse generator 7 is provided in conjunction with the rotation of the final rolling roll 2. For example, steel plate 1 is 1 mm
One pulse is generated for each movement.

On the other hand, a pulse generator 7 receives a detection signal indicating that the leading end of the steel plate 1 has passed from the passing plate detector 6.
Surface detector 5 every time the pulse transmitted from
An image processing device which takes in a detection signal from the device and performs image processing described in detail later, a display device 9 for displaying an image of the steel sheet surface processed by the image processing device 8, and a display device 10 which is also processed by the image processing device 8. This is an alarm that generates an alarm when there is a defect in the image of the steel plate surface.

FIG. 2 is a block diagram showing a configuration example of the image processing device 8.

In FIG. 2, reference numeral 81 denotes a pulse which is transmitted from the pulse generator 7 when a detection signal of the passage of the leading end of the steel sheet is input from the passing sheet detector 6, and optically changes the surface of the steel sheet from the surface detector 5. Is an image signal extracting unit that takes in the detected signal detected in real time.

The image signal extracting section 81 includes the surface detector 5
In the case where there is a defect on the steel sheet surface and a defect on the steel sheet surface based on the detection signal optically detected in the above step, the defect and the defect position specified from the pulse count value are extracted, and the image data is counted as pulses. Each time it is performed, it is stored in the image memory 83 via the writing processing unit 82, and the defect position is stored in the defect position memory 84.

Reference numeral 85 denotes a scroll processing unit for taking in the image data stored in the image memory 83 and performing scroll processing. The scroll processing unit 85 reduces the image data to, for example, about 1/3 of the actual flow speed of the steel plate. It has a function to delay it.

Reference numeral 86 denotes a scale generator for generating a scale for the image data to be scroll-processed by the scroll processor 85.

On the other hand, 87 is a defect mark generation unit for generating a defect mark for marking a defect position stored in the defect position memory 84, and 88 is a scroll processing unit 8
If the image data subjected to the scroll processing in step 5 and the scale and image data generated by the scale generation unit 86 include a defect on the surface of the steel plate, the mark generated by the defect mark generation unit 87 is fetched and displayed. Is a display processing unit that performs necessary processing on the display device 9 and outputs the result to the display device 9.

When the image data scroll-processed by the scroll processing unit 85 has a defect, the alarm unit 10 detects the defect position stored in the defect position memory 84 in synchronization with the defect of the image data. This is an alarm output unit that outputs an alarm.

Next, the operation of the surface inspection apparatus configured as described above will be described.

Now, in the hot rolling process, when the production of the steel sheet is started, the steel sheet 1 which has exited the final roll 2 of the finishing mill is sent to the winder 4 by the table roll 3.

At this time, a detection signal of the passage of the leading end of the steel plate 1 from the passing plate detecting device 6 is transmitted to the image signal extracting section 8 of the image processing device 8.
1, the image signal extraction unit 81 takes in a detection signal from the surface detector 5 every time the pulse transmitted from the pulse generator 7 is counted, and when there is image data and a defect on the steel plate surface, Extracts the defect position specified from the defect and the pulse count value.

The image data extracted by the image signal extracting section 81 is written into the image memory 83 by the writing processing section 82 every time a pulse is counted, and the defect position is stored in the defect position memory 84.

The image data written in the image memory 83 is processed by the scroll processing unit 85 to determine the actual flow speed of the steel sheet.
The scroll processing is performed so as to be about / 3, and the result is input to the display processing unit 88. At this time, the scale generation unit 86 generates a display scale for the scrolled image data, and the scale is input to the display processing unit 88.

Here, the scroll processing of the image data is performed as follows.
For example, as shown in FIG. 3A, the coil rolling is performed at an interval of one minute with respect to the image data of 30 seconds, and the image processing is performed by flowing the image data at 1 minute and 30 seconds. The scrolling of the image data is performed at a speed that is 1/3 to slightly higher than the flow speed. Since this scroll pattern can inspect all images from the beginning to the end of the steel plate, it can cope with sudden flaws. Also, as shown in FIG. 3B, scrolling can be performed even if 1/3 image data is flowed at 1/3 speed with respect to image data of coil rolling for a predetermined time. This scroll pattern can cope with defects that occur continuously in the steel sheet, for example, abnormalities such as periodic flaws due to rolls and waving of the steel sheet.

If the image data includes a defect on the surface of the steel sheet, the mark generated by the defect mark generation unit 87 is input to the display processing unit 88. In this case, the defect mark generation unit 87 can change the position, shape, or color of the mark according to the type and degree of the defect. For example, a light flaw is surrounded by a thin line, and a heavy flaw is surrounded by a thick line or a red line.

In the display processing unit 88, when the scrolled image data, its scale, and the image data include a defect on the steel sheet surface, the defect mark generation unit 87
The processings necessary for display are performed by taking in the marks generated in step (1), and these are scroll-displayed on the display device 9.

FIG. 4 shows a display example of scroll display on the screen of the display device 9.

In this display example, it can be seen that scales are attached to the upper end and the right end of the screen, and that roll flaws (portions shown by white lines) are displayed at fixed intervals at two places on the left and right of the center of the screen.

On the other hand, when a defect on the surface of the steel sheet is extracted by the image signal extracting section 81, an alarm is output from the alarm output section 89 to the alarm device 10 based on the defect position stored in the defect position memory 84. In this case, a sound, light, or vibration is emitted from the alarm 10 as an alarm. Therefore, even if the operator is away from the display device 9 side, it can be recognized that a defect has appeared on the steel plate surface.

As described above, in this embodiment, the detection signal optically detected by the surface detector 5 is
The image data extraction unit 81 extracts the image data of the steel sheet surface and, if there is a defect on the steel sheet surface, extracts the defect and its position. Scroll processing is performed to display the image at a low speed, and for a defect, a mark to be added to the defect position is generated by a defect mark generation unit 87, and these are subjected to processing necessary for display by a display processing unit 88. The image is displayed on the screen.

Therefore, the surface image data of the steel sheet can be collected at a constant resolution without depending on the flow velocity of the steel sheet, and can be displayed in slow motion from the head of the steel sheet or from an arbitrary set location, so that defects and abnormalities in the properties of the steel sheet surface can be obtained. Can be easily and reliably detected at an early stage, and the product yield is improved.

Further, since the defect position appearing in the surface image of the steel plate is displayed with a mark, it is possible to carefully observe the defect portion, and the defect is not overlooked.

Further, the image of the surface of the steel sheet processed by the display processing unit 88 and displayed on the display device 9 is provided with the scale generated by the scale generation unit 86. The position in the direction can be easily specified.

On the other hand, even if the operator cannot monitor the display device for other operations, the occurrence of the defect can be notified from the alarm output unit 89 by sound or a rotating lamp when the defect position is extracted. In this case, by changing the state of the alarm from the alarm output unit 89 according to the type and degree of the defect, the severity of the defect can be recognized.

In the above embodiment, the case where the image data is scrolled and displayed at about 1/3 of the actual flow speed of the steel plate has been described. However, the scroll speed may be set to a lower speed. May be displayed as a still image.

The display processing unit 88 has a function of enlarging a portion designated by the operator at an arbitrary magnification. The displayed image is usually 1/2 to 1/1 of the actual size
Although it is compressed to about 0, by using the enlargement function,
The defect image can be observed at its actual size or further enlarged, and the accuracy of the inspection can be further improved.

Many of the device configurations shown in FIG. 2 can be realized as software of a computer.

[0050]

As described above, according to the present invention, a defect on the surface of a steel sheet is displayed by displaying an image of the surface of the steel sheet optically collected while rolling the steel sheet at a speed lower than the actual flow speed of the steel sheet. And a surface inspection apparatus capable of reliably and easily finding abnormalities.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a surface inspection apparatus according to the present invention.

FIG. 2 is a block diagram showing a configuration example of an image processing apparatus according to the embodiment;

FIG. 3 is a diagram showing an example of a scroll pattern processed by a scroll processing unit of the image processing apparatus.

FIG. 4 is a halftone image in which a steel sheet surface processed by the image processing apparatus according to the embodiment is displayed on a monitor.

FIG. 5 is a block diagram showing a schematic configuration of an example of a conventional surface defect inspection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Steel plate 2 ... Rolling roll of finishing mill 3 ... Table roll 4 ... Winding machine 5 ... Surface detector 6 ... Passing detector 7 ... Pulse generator 8 ... Image processing device 9 ... Display device 10 ... Alarm 81 Image signal extraction unit 82 Write processing unit 83 Image memory 84 Defect position memory 85 Scroll processing unit 86 Scale processing unit 87 Defect mark generation unit 88 Display processing unit 89 Alarm processing unit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasuo Kushida 1-2-1 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 2G051 AA37 AB07 BB17 CA03 CC07 DA06 DA15 EA11 EA14 EA30 EB09 EC01 FA02 FA04 FA10

Claims (5)

[Claims] In a hot rolling process for producing a steel sheet by a hot rolling mill, a surface detector for optically detecting the surface of the steel sheet and a detection signal based on a detection signal optically detected by the surface detector. Image data of the steel sheet surface and image signal extraction means for extracting the defect and its position when there is a defect on the steel sheet surface, and the image data extracted by the image signal extraction means at a speed lower than the flow speed of the steel sheet. Scroll processing means for performing scroll processing for display; defect mark generating means for generating a mark attached to a defect position on the image data when a defect on the surface of the steel sheet is extracted by the image signal extracting means; Display processing for performing processing necessary for displaying the scrolled image data and the mark generated by the defect mark generating means and outputting the processed data to a display device A surface inspection apparatus comprising: 2. The surface inspection apparatus according to claim 1, wherein
A surface inspection apparatus, further comprising scale generation means for generating a scale indicating an image position of a steel sheet surface displayed on the display device in correspondence with image data scrolled by the scroll processing means. 3. The surface inspection apparatus according to claim 1, wherein
The defect mark generating means changes a position, a shape, or a color of a mark attached to a defective portion on the surface of the steel plate displayed on the screen of the display device according to the type or degree of the defect. apparatus. 4. The surface inspection apparatus according to claim 1, wherein
A surface inspection apparatus comprising: an alarm output unit that outputs an alarm by sound, light, or vibration when a defect on a steel sheet surface is extracted by the image signal extraction unit. 5. The surface inspection apparatus according to claim 4, wherein
A surface inspection apparatus, wherein the alarm output means changes an alarm state depending on the type or degree of the defect.