JP2023053825A - Rolling roll surface defect detection device, and surface defect detection method - Google Patents

Abstract

To make it possible to detect surface defects of a rolling roll with good accuracy.SOLUTION: A surface defect detection device for detecting surface defects of a rolling roll 1 comprises: a rotating mechanism which axially rotates the rolling roll 1; a displacement sensor 7 in which a detection part faces a surface of the rolling roll 1 and which measures a distance to a roll surface of the rolling roll 1; and a reciprocation carriage 6 which supports the displacement sensor 7, and is movable in a reciprocation direction parallel to a direction along an axial direction of the rolling roll 1.SELECTED DRAWING: Figure 1

Description

The present invention relates to a rolling roll surface defect detection apparatus and surface defect detection method for detecting defects existing on the roll surface of a rolling roll such as a hot rolling roll.

In the conventional surface inspection of rolling rolls, an ultrasonic probe is held at a certain distance from the surface of the roll to be inspected, ultrasonic waves are propagated from the ultrasonic probe to the cylindrical body through an acoustic coupling medium, and the A method called ultrasonic flaw detection for detecting defects existing on the surface of a roll or just below the surface has been performed (see, for example, Patent Document 1).

In addition, the roll surface defect detection apparatus irradiates a single light source, has a linear sensor or an area sensor that detects the reflected or diffused light, and outputs the sensor output to detect surface defects of the roll to be inspected. There is also a method (see Patent Document 2, for example).

JP 2012-103033 A JP 2010-14515 A

The roll to be inspected has been used in hot rolling for a long period of time, and the surface of the base is very rough and difficult to see. For this reason, there has been a problem that the conventional visual inspection misses surface defects that have a detrimental effect on the steel sheet.
In addition, in the method of receiving light optically reflected or diffused from the surface with a camera, the reflected light from the surface is attenuated, making it difficult to capture defects existing therein.

On the other hand, in order to facilitate the determination of defects in the roll to be inspected after rolling, the inspection is performed after grinding the first layer of the extreme surface of the roll surface with a grinder, so that the visibility is improved. method is also implemented. However, in this method, for example, every 1/6 rotation of the entire circumference, the inspection is performed while the workpiece is stopped.
Also, visual inspection after grinding is an effective inspection method for defects with relatively deep dents. However, since the surface layer is ground, there is a problem that convex defects and extremely shallow dent defects are eliminated.

Furthermore, it is difficult to record detailed inspection results of the entire circumference and width of the roll to be inspected, and when it is found that surface defects have occurred in the roll period in the steel plate product, it is not possible to determine whether the roll has defects at the corresponding position. There was a problem that it was not possible to check later.

SUMMARY OF THE INVENTION It is an object of the present invention to detect surface defects of rolling rolls with high precision.

To solve the problem, one aspect of the present invention is a surface defect detection device for detecting surface defects of a rolling roll, wherein a rotating mechanism for axially rotating the rolling roll and a detection unit face the surface of the rolling roll. and a carriage that supports the displacement sensor and is movable in a reciprocating direction that is parallel to the axial direction of the rolling roll. The gist of it is to be prepared.

Further, an aspect of the present invention is a surface defect detection method for detecting surface defects of a rolling roll, wherein a displacement sensor is arranged opposite to the roll surface of the rolling roll, and the displacement sensor is detected while rotating the rolling roll. By moving the in a direction parallel to the axial direction of the rolling roll, the displacement sensor continuously measures the surface displacement data up to the roll surface, and from the continuously measured surface displacement data, the surface The gist is to detect defects.

According to the aspect of the present invention, since the surface defect is determined from the surface displacement amount of the rolling roll, it becomes a rough surface after hot rolling, which was not good at conventional optical surface inspection devices and ultrasonic flaw detection. It has become possible to detect surface defects with higher accuracy even on the roll surface of a rolling roll that has been exposed to the surface.

In addition, in the aspect of the present invention, for example, it is possible to replace the static visual inspection after the first skin grinding, which was conventionally performed for 30 minutes per piece, and it is possible to shorten the work time related to the inspection. .

FIG. 4 is a side view showing the relationship between rolling rolls and displacement sensors; It is a top view explaining the apparatus structure of a surface defect detection apparatus. It is a figure explaining the structure of a control part. It is a figure explaining the change of the position of a displacement sensor. It is a figure which shows the scanning outline|summary of a roll surface. It is a figure explaining concatenation of data. FIG. 10 is a diagram showing connected defects; FIG. 4 is a diagram showing an example of two-dimensional mapping of a roll surface; It is a figure which shows an example of the three-dimensional shape display result of a roll surface defect.

Next, embodiments of the present invention will be described with reference to the drawings.
The surface defect detection apparatus of this embodiment includes a rotating mechanism, a carriage 6, a displacement sensor 7, laser rangefinders 9A and 9B, and a controller 10, as shown in FIGS.
As shown in FIG. 3, the control unit 10 includes an advance/retreat control unit 10A, a defect position calculation unit 10B, a defect selection unit 10D, a visualization processing unit 10E, a counting unit 10F, and a shape display unit 10G.

<Rotating Mechanism>
The rotating mechanism is a mechanism for rotating the rolling roll 1 about its axis.
Rolling rolls 1 are installed in the apparatus with chocks 2 (bearings). The rolling roll 1 has one shaft connected to a tailstock 3 and the other shaft connected to a headstock 4 . A motor 4A such as a single-axis servomotor is arranged on the headstock to rotate the other shaft. By driving the motor 4A, the rolling roll 1 can be axially rotated.
Reference numeral 5 is a rotation detector that detects rotation of the motor 4A.

<Rocket 6>
A roll grinder carriage 6 is arranged beside the rolling rolls 1 .
The carriage 6 is movable in a reciprocating direction parallel to the axial direction of the rolling rolls 1 . The reason why the direction parallel to the direction along the axis is defined is to show that the direction may not be completely parallel to the axis.

<Displacement sensor 7>
The displacement sensor 7 is supported by the carriage 6 and arranged so as to directly face (oppose) the rolling rolls 1 . A displacement sensor 7 measures the distance of the rolling roll 1 to the roll surface. A known displacement sensor may be adopted as the displacement sensor 7 .
An advancing/retreating mechanism 8 is provided for advancing/retreating the displacement sensor 7 with respect to the carriage 6 toward the roll surface.
The advancing/retreating mechanism 8 is composed of a linear guide device and other servo mechanisms.

<Laser rangefinders 9A and 9B>
Two-dimensional laser rangefinders 9A and 9B are installed on the carriage 6 on both the left and right sides of the displacement sensor 7 in the advancing/retreating direction.
Specifically, laser rangefinders 9A and 9B are provided at upstream and downstream positions in the movement direction of the displacement sensor 7 in the reciprocating direction with respect to the installation position of the displacement sensor 7 . It is sufficient if at least the laser rangefinder 9A on the upstream side is provided.
The laser rangefinders 9A and 9B constitute a distance detection sensor and detect the distance to the roll surface.

Here, since the displacement sensor 7 and the laser rangefinders 9A and 9B are both installed on the carriage 6, they are configured to move together in the reciprocating direction.
The measurement resolution of the displacement sensor 7 may be superior to that of the laser rangefinders 9A and 9B.

<advance/retreat control unit 10A>,
The control unit 10 includes an advance/retreat control unit 10A.
The advance/retreat control unit 10A advances/retreats the displacement sensor 7 toward the roll surface via the advance/retreat mechanism 8 according to the distances detected by the laser rangefinders 9A and 9B. For example, when the advance/retreat control unit 10A determines that the displacement sensor 7 faces the roll surface based on the detection values of the laser rangefinders 9A and 9B, while avoiding interference between the displacement sensor 7 and the roll surface, the displacement sensor 7 is brought close to the roll surface. By bringing it closer, the accuracy of the measured value is improved.

Here, information such as the roll diameter of the rolling rolls 1 and the roll barrel length is inputted in advance from the control personal computer to the control unit 10 and set, thereby setting the displacement sensor 7 to the appropriate distance standard with respect to the roll surface. come close to.
At this time, the rolling rolls 1 are attached with the chocks 2 , and the displacement sensor 7 may interfere with the chocks 2 depending on the combination of the roll diameter and the chocks 2 . For example, as shown in FIG. 2, the chock 2 may protrude toward the carriage 6 beyond the diameter of the rolling roll 1 . At this time, if the displacement sensor 7 is brought close to the predetermined distance reference relative to the rolling roll 1 , the displacement sensor 7 interferes with the chock 2 .

On the other hand, the advance/retreat control unit 10A enables detection of the roll trunk end of the rolling roll 1 by at least the distance detected by the laser rangefinder 9A on the upstream side of the displacement sensor 7, and the displacement sensor 7 detects the roll trunk end. The displacement sensor 7 is retracted until it reaches the position. Then, when it is determined that the displacement sensor 7 has reached the roll trunk end portion, proximity/retreat control is performed to bring the displacement sensor 7 closer to the roll surface.
Here, during inspection, the carriage 6 is moved in one of the forward and backward directions at a constant moving speed corresponding to the rotation speed (constant speed) of the roll based on detection by the rotation detector.

For example, the position where the distance detected by the laser rangefinder 9A suddenly increases can be detected as the roll trunk end. That is, as shown in FIG. 4, in the state (1)→(2), the displacement sensor 7 is gradually moved toward the chock 2 based on the signals from the laser rangefinders 9A and 9B, and from (2) to ( 3), and when it is determined that the distance detected by the laser rangefinders 9A and 9B has increased, the displacement sensor 7 is brought closer to the roll surface. Then, the roll surface is continuously measured by the displacement sensor 7 up to the position of (5). Further, when it is determined that the distance detected by the laser rangefinders 9A and 9B has suddenly decreased after moving to the right from (5), the displacement sensor 7 is retracted to the carriage side. This prevents the displacement sensor 7 from interfering with the chock 2 .
Further, even when the displacement sensor 7 approaches the roll surface and is in the process of measuring the distance to the roll surface, the information detected by the laser rangefinders 9A and 9B can more reliably prevent the displacement sensor 7 from interfering with the roll surface. becomes.

<Surface measurement>
In the above configuration, continuous measurement is performed by the displacement sensor 7 while the rolling roll 1 is operated at a constant number of revolutions and the carriage 6 is operated at a constant speed. Measure the shape. Although the scanning direction is not tilted with respect to the roll rotation direction in FIG. 5, actually, the scanning is performed in a direction slightly tilted with respect to the roll rotation direction. Displacement data (distance data) measured by the displacement sensor 7 becomes surface displacement data.

In the above description, the roll surface was scanned and inspected on the grinder, but the present embodiment is not limited to this. The surface defect detector may be installed in the rolling mill and the roll surface may be measured while the rolls are rotated. In this case, the rolling mill constitutes the rotating mechanism.
Further, a plurality of displacement sensors 7 may be arranged in the axial direction of the roll, and each displacement sensor 7 may be used for measurement for each region.

This measurement provides surface displacement data for the entire roll surface. Note that the inspection area may not be the entire surface of the roll.

<Defect position calculator 10B>
The controller 10 includes a defect position calculator 10B. The defect position calculation unit 10B performs a process of obtaining a defect position on the roll surface from the set of acquired surface displacement data.

For example, the defect position calculation unit 10B uses the moving average value of the surface displacement data measured by the displacement sensor 7 as the roll surface reference value, and determines the position of the surface displacement data whose difference from the roll surface reference value exceeds a preset threshold value. Defect position. That is, the surface displacement amount is obtained from the difference between the moving average value of the measured values before and after and the measured value. That is, the surface displacement amount is adjusted to a value based on the roll surface reference value.

For example, the moving average value of the surface displacement data for one rotation of the roll is used as the roll surface reference value, and the value obtained by subtracting the roll surface reference value from each surface displacement data for one rotation of the roll is used as the surface displacement amount at each measurement position. . Then, when the surface displacement amount exceeds the threshold value, the measured position is determined as the defect position.
A simple roll profile measurement value may be used as the moving average value.

Further, the defect position calculation unit 10B obtains two-dimensional displacement information obtained by planarizing the detection area of the roll surface from the surface displacement data measured by the displacement sensor 7 . That is, the surface displacement amount at each measurement position on the roll surface is obtained as two-dimensional displacement information.

At this time, the roll surface reference plane determined from the moving average value of the surface displacement data is obtained, and the deviation from the roll surface reference plane in the two-dimensional displacement information is obtained from the two-dimensional displacement information and the roll surface reference plane. A portion exceeding a preset threshold value may be set as the defect position. For example, by superimposing a layer of two-dimensional displacement information and a layer of the roll surface reference plane, the surface displacement amount and the defect position are obtained from the unevenness.

<Defect shape calculator 10C>
The controller 10 includes a defect shape calculator 10C.
The defect shape calculation unit 10C connects the surface displacement data (surface displacement amount data) of the defect position and its vicinity in the two-dimensional displacement information as shown in FIG. Detect as shape. As a result, one surface defect can be represented by three-dimensional feature amounts of maximum width, maximum length, and maximum depth (see FIG. 7). For example, one surface defect can be three-dimensionally extracted by a continuous change (gradient) of the amount of displacement. The width direction is the roll axial direction, and the length is the roll circumferential direction (roll rotation direction).
In FIG. 9, in the two-dimensional map, ◯ indicates the detected defect position 20A, and Δ indicates the portion of measurement abnormality (defect position below the threshold value) having a smaller unevenness amount than the defect position. In the example of FIG. 9, the defect position 20A and the data of the area where the data of the measurement abnormality are continuous are connected and regarded as one surface defect 20. In the example of FIG.

<Defect Sorting Unit 10D>
The control unit 10 includes a defect screening unit 10D.
The defect selection unit 10D selects whether or not each surface defect obtained by the defect shape calculation unit 10C is a surface defect to be detected based on the three-dimensional feature amount specifying the three-dimensional shape.

For example, the defect should be detected when the depth is greater than or equal to a predetermined value and the maximum width and maximum length are greater than or equal to preset values.
For example, even if the depth is deep, if the width and length are small, it may be ignored as a defect.

<Visualization processing unit 10E>
The control unit 10 includes a visualization processing unit 10E.
The visualization processing unit 10E performs processing for visualizing two-dimensional displacement information as a two-dimensional map.
The visualization processing unit 10E performs processing for visualizing and displaying surface defects by displaying the positions of the surface defects 20 on a two-dimensional map as shown in FIG.

Moreover, the visualization processing unit 10E preferably divides the two-dimensional map into a plurality of areas as shown in FIG. 8, and visualizes and displays the areas where the positions of the surface defects 20 are present. That is, since the surface defect is small, it is preferable to visualize and display the area 30 where the position of the surface defect 20 exists in order to make the presence easier to understand.

<Aggregation unit 10F>
The control unit 10 includes a counting unit 10F.
The tallying unit 10F tallies the number of surface defects present in each area. That is, a process of aggregating statistical values of the number of surface defects 20 existing in each sectioned area and the amount of displacement is performed.

<Shape display unit 10G>
The control section 10 includes a shape display section 10G.
The shape display unit 10G displays the detected surface defect in a three-dimensional shape, as shown in FIG. 9, based on the calculation of the defect shape calculation unit 10C.

(Other operations)
Based on the detected value from the rotation detector 5, with the position to be detected as a reference of 0°, based on the set roll rotation speed and the movement speed of the carriage 6, the two-dimensional roll surface is obtained from the measurement data of the displacement sensor 7. is created and displayed as two-dimensional mapping.
For example, in mapping, the amount of displacement is visualized by displaying 256 black and white gradations.

The amount of displacement is determined by upper and lower threshold values (upper limit and lower limit), and deviations from the upper limit of the displacement are displayed in yellow, and deviations from the lower limit of the displacement are displayed in red, for example. This yellow or red position is the position of the surface defect.
As shown in FIG. 6, continuous data of threshold outliers are combined as the same defect candidate. The combined data is calculated as a three-dimensional feature amount consisting of maximum data in the width direction (axial direction), the circumferential direction, and the depth direction.

Then, it is compared with the threshold value of the three-dimensional feature amount consisting of the width, circumference, and depth set in advance, and for example, for the surface defect exceeding the threshold value in two or more feature amounts, the roll surface defect portion to be detected Sort out. The conditions for selection as roll surface defects are not limited to AND conditions. Selection may be performed using an OR condition or multiple levels of thresholds.

In this embodiment, in order to display the detection positions of the roll surface defects, the roll surface mapping divides the meshes in the width direction, and visually displays the meshes in which the surface defects are detected with a red frame or the like. This makes it easier to visually recognize the defect position.
The mesh is, for example, a width of 50 mm and a mesh every 45° in the circumferential direction. The multiple divisions may be finer meshes.

Further, the number of detected defects may be aggregated and displayed for each mesh. Instead of tallying the number of defects, an average displacement amount or surface roughness may be calculated and displayed for each mesh.
Further, an enlarged image of mapping or a three-dimensional shape of the selected defect portion may be displayed. In this case, the state of the defect can be displayed in plane, side, and slope views.

Then, based on the display result of the two-dimensional mapping in which the roll surface is two-dimensionally developed, it is possible to inspect the actual roll at the defect position and judge the quality of the rolling roll 1 . That is, the actual rolling roll 1 is inspected based on the two-dimensional mapping of the roll surface. This makes it possible to determine the quality of the rolling rolls 1 with higher accuracy.

Here, FIG. 8 shows an example of two-dimensional mapping of the roll surface, showing the result of verifying the roll having artificial defects created by electric discharge machining as the rolling roll 1 . After measurement with the threshold set to 0.8 × 0.8 × 0.3 mm, the mesh in which artificial defects exceeding the threshold exist is displayed in a red frame, and the enlarged image and surface defects 20 as shown in FIG. Dimensional shape can be confirmed.

As described above, in the present embodiment, after the rolling roll 1 used for hot rolling having a rough roll surface base is inspected by the surface displacement sensor 7 over the entire circumference and width, the measurement data that deviate from the threshold value are linked and integrated. The maximum width, maximum length, and maximum depth of the surface defect are calculated. Further, since the three-dimensional threshold determination is performed, the defect portion and background noise can be distinguished more accurately, and the visibility can be improved.
(others)

The present invention can also take the following configurations.
(1) A surface defect detection device for detecting surface defects of a rolling roll,
a rotating mechanism for axially rotating the rolling roll;
a displacement sensor having a detection unit facing the surface of the rolling roll and measuring the distance of the rolling roll to the roll surface;
a carriage that supports the displacement sensor and is movable in a reciprocating direction that is parallel to the direction along the axial direction of the rolling roll;
Prepare.
(2) An advance/retreat mechanism is provided for advancing/retreating the displacement sensor toward the roll surface.
(3) a distance detection sensor that is supported by the carriage and detects the distance to the roll surface at a position on the upstream side in the moving direction of the displacement sensor in the reciprocating direction with respect to the installation position of the displacement sensor;
an advance/retreat control unit that advances/retreats the displacement sensor via an advance/retreat mechanism according to the distance detected by the distance detection sensor;
with
The advance/retreat control unit causes the displacement sensor to approach the roll surface when determining that the displacement sensor is at a position facing the roll surface based on the detection value of the distance detection sensor.
(4) A defect position calculator for determining the defect position of the roll surface based on the surface displacement data measured by the displacement sensor.
(5) The defect position calculation unit uses the moving average value of the surface displacement data measured by the displacement sensor as a roll surface reference value, and the position of the surface displacement data whose difference from the roll surface reference value exceeds a preset threshold value. is the defect position.
(6) The defect position calculation unit obtains two-dimensional displacement information obtained by planarizing the detection area of the roll surface from the surface displacement data measured by the displacement sensor.
(7) The defect position calculation unit obtains a roll surface reference plane determined from the moving average value of the surface displacement data, and obtains the two-dimensional displacement information from the two-dimensional displacement information and the roll surface reference plane. , the portion where the deviation from the roll surface reference plane exceeds a preset threshold value is defined as the defect position.
(8) A defect shape calculator that expresses one surface defect with three-dimensional feature amounts of maximum width, maximum length, and maximum depth by performing connection processing on the surface displacement data.
(9) A defect selection unit for selecting whether or not the surface defect is a surface defect to be detected from the three-dimensional feature amount.
(10) A visualization processing unit for visualizing the two-dimensional displacement information as a two-dimensional map.
(11) The visualization processing unit visualizes surface defects by displaying defect positions on the two-dimensional map.
(12) The visualization processing unit divides the two-dimensional map into a plurality of areas and visualizes the areas where the defect positions are present.
(13) A tallying unit for tallying the number of surface defects existing in each area.
(14) A shape display unit for displaying the detected surface defect in a three-dimensional shape.
(15) A surface defect detection method for detecting surface defects of a rolling roll,
A displacement sensor is arranged opposite to the roll surface of the rolling roll, and while the rolling roll is axially rotated, the displacement sensor is moved in a reciprocating direction parallel to the direction along the axial direction of the rolling roll. , surface displacement data up to the roll surface is continuously measured by the displacement sensor, and surface defects are detected from the continuously measured surface displacement data.
(16) configuring the displacement sensor so as to be able to advance and retreat toward the roll surface;
A distance detection sensor for detecting a distance to the roll surface is provided upstream in the moving direction of the displacement sensor in the reciprocating direction, and the distance of the displacement sensor from the roll surface is adjusted based on the detection value of the distance detection sensor. , to avoid interference between the displacement sensor and the roll surface.
(17) The moving average value of the surface displacement data continuously measured by the displacement sensor is used as the roll surface reference value, and the position of the surface displacement data where the difference from the roll surface reference value exceeds a preset threshold value is the defect position. and
(18) From the surface displacement data continuously measured by the displacement sensor, obtain two-dimensional displacement information obtained by planarizing the detection area of the roll surface.
(19) A predetermined threshold value for deviation from the roll surface reference plane in the two-dimensional displacement information, based on the roll surface reference plane determined from the moving average value of the surface displacement data and the two-dimensional displacement information. is defined as the defect position.
(20) By concatenating the surface displacement data, one surface defect is represented by three-dimensional feature amounts of maximum width, maximum length, and maximum depth.
(21) Select whether or not the surface defect should be detected based on the three-dimensional feature amount.
(22) Visualize and display the two-dimensional displacement information as a two-dimensional map.
(23) Display defect positions on the two-dimensional map.
(24) dividing the two-dimensional map into a plurality of areas, and visualizing and displaying the areas where the defect positions are present;
(25) Aggregate the number of surface defects present in the displayed area.
(26) Display the detected surface defects in a three-dimensional shape.

1 rolling roll 2 chock 4A motor (rotating mechanism)
6 carriage 7 displacement sensor 8 advancing/retreating mechanism 9A, 9B laser rangefinder (distance detection sensor)
10 control unit 10A advance/retreat control unit 10B defect position calculation unit 10C defect shape calculation unit 10D defect selection unit 10E visualization processing unit 10F totalization unit 10G shape display unit 20 surface defect 20A defect position 30 area

Claims (26)

A surface defect detection device for detecting surface defects of a rolling roll,
a rotating mechanism for axially rotating the rolling roll;
a displacement sensor having a detection unit facing the surface of the rolling roll and measuring the distance of the rolling roll to the roll surface;
a carriage that supports the displacement sensor and is movable in a reciprocating direction that is parallel to the direction along the axial direction of the rolling roll;
A surface defect detection device comprising: An advance/retreat mechanism for advancing/retreating the displacement sensor toward the roll surface,
2. The surface defect detection apparatus according to claim 1, wherein: a distance detection sensor that is supported by the carriage and detects the distance to the roll surface at a position on the upstream side in the moving direction of the displacement sensor in the reciprocating direction with respect to the installation position of the displacement sensor;
an advance/retreat control unit that advances/retreats the displacement sensor via an advance/retreat mechanism according to the distance detected by the distance detection sensor;
with
When the movement control unit determines that the displacement sensor faces the roll surface based on the detection value of the distance detection sensor, the movement control unit causes the displacement sensor to approach the roll surface.
3. The surface defect detection apparatus according to claim 2, wherein: Based on the surface displacement data measured by the displacement sensor, a defect position calculation unit for determining the defect position of the roll surface,
The surface defect detection apparatus according to any one of claims 1 to 3, characterized in that: The defect position calculation unit uses the moving average value of the surface displacement data measured by the displacement sensor as a roll surface reference value, and determines the position of the surface displacement data whose difference from the roll surface reference value exceeds a preset threshold as the defect position. to be
5. The surface defect detection apparatus according to claim 4, characterized in that: The defect position calculation unit obtains two-dimensional displacement information obtained by planarizing the detection area of the roll surface from the surface displacement data measured by the displacement sensor.
6. The surface defect detection device according to claim 4 or 5, characterized in that: The defect position calculation unit obtains a roll surface reference plane determined from the moving average value of the surface displacement data, and from the two-dimensional displacement information and the roll surface reference plane, the above-mentioned The defect position is defined as a portion where the deviation from the roll surface reference plane exceeds a preset threshold value,
7. The surface defect detection apparatus according to claim 6, characterized in that: A defect shape calculation unit that expresses one surface defect with three-dimensional feature amounts such as maximum width, maximum length, and maximum depth by performing connection processing on the surface displacement data.
8. The surface defect detection apparatus according to claim 7, characterized in that: A defect selection unit that selects whether or not the surface defect is a surface defect to be detected from the three-dimensional feature amount,
9. The surface defect detection apparatus according to claim 8, characterized in that: A visualization processing unit that visualizes the two-dimensional displacement information as a two-dimensional map,
10. The surface defect detection apparatus according to any one of claims 6 to 9, characterized in that: The visualization processing unit visualizes surface defects by displaying defect positions on the two-dimensional map.
11. The surface defect detection apparatus according to claim 10, characterized in that: The visualization processing unit divides the two-dimensional map into a plurality of areas and visualizes the area where the defect position exists.
12. The surface defect detection apparatus according to claim 11, wherein: A counting unit that counts the number of surface defects present in each area,
13. The surface defect detection apparatus according to claim 12, characterized in that: A shape display unit that displays the detected surface defects in a three-dimensional shape,
14. The surface defect detection apparatus according to any one of claims 8 to 13, characterized in that: A surface defect detection method for detecting surface defects of a rolling roll,
A displacement sensor is arranged opposite to the roll surface of the rolling roll, and while the rolling roll is axially rotated, the displacement sensor is moved in a reciprocating direction parallel to the direction along the axial direction of the rolling roll. , continuously measuring surface displacement data up to the roll surface with the displacement sensor, and detecting surface defects from the continuously measured surface displacement data;
A surface defect detection method characterized by: The displacement sensor is configured to be movable toward and away from the roll surface,
A distance detection sensor for detecting a distance to the roll surface is provided upstream in the moving direction of the displacement sensor in the reciprocating direction, and the distance of the displacement sensor from the roll surface is adjusted based on the detection value of the distance detection sensor. to avoid interference between the displacement sensor and the roll surface,
16. The surface defect detection method according to claim 15, wherein: The moving average value of the surface displacement data continuously measured by the displacement sensor is taken as the roll surface reference value, and the position of the surface displacement data where the difference from the roll surface reference value exceeds a preset threshold is taken as the defect position.
17. The surface defect detection method according to claim 15 or 16, characterized in that: From the surface displacement data continuously measured by the displacement sensor, two-dimensional displacement information obtained by planarly developing the detection area of the roll surface is obtained.
18. The surface defect detection method according to claim 17, wherein: Based on the roll surface reference plane determined from the moving average value of the surface displacement data and the two-dimensional displacement information, a portion of the two-dimensional displacement information in which the deviation from the roll surface reference plane exceeds a preset threshold value. Let be the defect position,
19. The method of detecting surface defects according to claim 18, wherein: By concatenating the surface displacement data, one surface defect is represented by three-dimensional feature amounts of maximum width, maximum length, and maximum depth.
20. The method of detecting surface defects according to claim 19, wherein: Selecting whether or not the surface defect is a surface defect to be detected from the three-dimensional feature amount,
21. The surface defect detection method according to claim 20, wherein: Visualizing and displaying the two-dimensional displacement information as a two-dimensional map,
The surface defect detection method according to any one of claims 18 to 21, characterized in that: Displaying the defect position on the two-dimensional map,
23. The surface defect detection method according to claim 22, wherein: dividing the two-dimensional map into a plurality of areas and visually displaying the areas where the defect positions exist;
24. The method of detecting surface defects according to claim 23, wherein: Aggregate the number of surface defects present in the area displayed above,
25. The surface defect detection method according to claim 24, characterized in that: display the detected surface defects in 3D shape,
The surface defect detection method according to any one of claims 18 to 25, characterized in that:

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