JP2721806B2 - Optical surface inspection device for rolling rolls - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CCD (Charge Coupled Device) in which a surface image of a rolling roll rotating while spraying cooling water is used in a rolling process of a steel plate or the like.
Rolling rolls are captured by an imaging device such as a camera to obtain a still image of the surface, and to grasp the roll replacement time to prevent the occurrence of scale flaws and the like caused by roughening of the rolling rolls on the steel plate. The present invention relates to an optical surface inspection device for a rolling roll for observing and inspecting the surface condition of a roll.

[0002]

2. Description of the Related Art A black scale is formed on the surface of a work roll (rolling roll) of a former stand in a hot finishing rolling mill for steel sheets with rolling. In this black scale, fine turtle-shaped cracks are generated. Depending on the rolling conditions, the black scale is peeled off, and a crater-like dent is formed on the roll surface in a belt shape along the circumferential direction, as shown in FIG. A rough skin condition called roll banding occurs. When rolling is performed on a work roll having a rough surface such as roll banding, the portion where the dent on the surface is transferred is pressed by the work roll of the subsequent stand, and the steel plate bites into the steel plate to generate scale flaws.

[0003] For this reason, the hot finish rolling mill is appropriately stopped, the work roll is pulled out from the stand, and a direct visual inspection of the roll surface is performed by an operator, and there is a rough surface which causes scale flaws such as roll banding. At times, or when the skin is rough, which may cause roll banding, the rolls are replaced.
Such an inspection by direct visual inspection of an operator has a disadvantage that a large amount of time and labor is required for removing and installing the work roll each time the inspection is performed, and this leads to a decrease in productivity.

[0004] In order to solve the above-mentioned drawbacks, the present applicant has obtained a still image of the surface of the rolling roll rotating while the cooling water is being sprayed thereon, and obtained the surface condition of the rolling roll from the still image of the rolling roll surface. There has been proposed an optical surface inspection device for a rolling roll capable of observing and inspecting a roll (JP-A-5-10888).

As shown in FIG. 8, the conventional optical surface inspection apparatus has a moving device 4, a housing box 5 having a window on the side facing the periphery of a rolling roll W, and a housing box 5 as shown in FIG. CCD camera 6 as an image pickup device (industrial video camera) disposed therein, annular xenon lamp 7 as a strobe illumination light source also disposed in housing box 5, mounted on the front of housing box 5. It comprises a water column forming nozzle 8, a control device 9, a frame memory 10 as an image storage device, and a CRT display 11 as an image display device. The image printer 12 connected to the control device 9 is used for making a hard copy of a still image of a rolling roll surface.

[0006] More specifically, between the rolling roll (work roll) W of the second finishing stand of the hot finishing rolling mill in the steel sheet hot rolling process and the rolling roll (not shown) of the next finishing stand. The feed screw shaft 1 is provided in parallel with the longitudinal direction (roll axis direction) of the rolling roll W, and is rotated forward and reverse by a motor (not shown). A moving device 4 including a moving block 2 to be moved and an air cylinder 3 mounted on the upper surface of the moving block 2
Is provided. A box-shaped housing box 5 in which a transparent window glass plate 5a as a window is fitted on the front surface facing the peripheral surface of the rolling roll W is attached to the tip of the piston rod 3a of the air cylinder 3 of the moving device 4. Have been. The CCD camera 6 disposed in the housing box 5 uses a two-dimensionally arranged CCD image pickup device, and uses a plurality of lenses to prevent image blur due to vibration of the rolling roll W and the like. The lens system has a small numerical aperture and a long focal length, and a deep focal depth.

The water column forming nozzle 8 is, as shown in FIG.
A surface of a rolling roll W having a water jet port communicating with the window glass plate 5a of the housing box 5 and rotating while the window glass plate 5a and the roll cooling water are sprinkled when pressurized water is supplied. And to form a water column between them. As a result, the window glass plate 5a is prevented from being contaminated by the roll cooling water containing dirt, and the rolling roll surface still image is prevented from being unclear. The cylindrical water column forming nozzle 8 is made of an acrylic resin having transparency, and when attached to the front surface of the housing box 5, water pressurized from a supply source (not shown) through a pressure water supply pipe 8 a is used. It is to be introduced inside.

[0008] The control device 9 receives an external inspection start signal S.
1 to turn on the annular xenon lamp 7 in synchronization with the vertical synchronizing signal of the CCD camera 6,
A device for taking in a roll surface still image signal from the camera 6 into the frame memory 10 and receiving the display command signal S2 to take out the roll surface still image signal stored (stored) in the frame memory 10 to the CRT display 11. is there. Control device 9, frame memory 10, CRT
The display 11 and the image printer 12 are arranged in an inspection room.

In the optical surface inspection apparatus having the above-mentioned structure, the housing box 5 in which the annular xenon lamp 7 and the CCD camera 6 are disposed is provided so that the rolling box W can be inspected in a predetermined direction in the longitudinal direction. When positioned, the control device 9 controls the synchronization signal of the CCD camera 6 and the lighting of the annular xenon lamp 7 synchronously. Illumination light from the xenon lamp 7 passes through the window glass plate 5a and the water column formed by the water column forming nozzle 8, and is applied to the surface of the rolling roll. The CCD camera 6 captures an image of the surface of the rolling roll W rotating while the roll cooling water is being sprayed through the window glass plate 5a and the water column, and outputs a signal of the roll surface still image that has been stationary. CC
The roll surface still image signal from the D camera 6 is stored in the frame memory 10. The above operation is sequentially repeated while moving the housing box 5 along the longitudinal direction of the rolling roll W by the moving device 4.

When the display command signal S2 is input to the control device 9 by the inspector's operation after the imaging of the roll surface is completed, the roll surface still image signal stored in the frame memory 10 corresponds to the imaging position. Then, the images are sequentially taken out for one screen and displayed on the CRT display 11 as still images. The inspector observes the state of the roll surface from the still image displayed on the monitor, and inspects the presence or absence of the surface roughness and the degree of the surface roughness. FIG. 10 is a diagram in which an example of a still image of the surface of the rolling roll is sketched, and a fine crack like a turtle formed on the black scale on the surface of the rolling roll (FIG. 1).
0 (a)) and the state (shown in FIG. 10 (b)) where the black scale has peeled off and roll banding has occurred.

[0011]

In the above-mentioned conventional optical surface inspection apparatus, the roll replacement operation is completed, a new roll W having been subjected to roll surface grinding is set on a rolling stand, and the roll is cooled. When hot rolling is started while water is sprinkled, first, the moving block 2 of the moving device 4 is moved to a position corresponding to the first inspection (observation) in the longitudinal direction of the rolling roll W, and then the air cylinder 3 is moved. The housing box 5 equipped with the water column forming nozzle 6 is advanced toward the roll surface of the rolling roll W by extending the piston rod 3a. At this time, each time the elongation stroke of the piston rod is a fixed and fixed value, and each time a rolling roll having a different surface grinding degree is newly set on the rolling stand by the roll exchange,
Since the roll diameters are different, the distance between the roll surface and the tip end of the water column forming nozzle changes. As described above, when the interval distance deviates from a preset value due to a change in the roll diameter, particularly when the roll diameter becomes small, the water column by the water column forming nozzle is sprayed on the roll surface. Many air bubbles may be generated in the water column by being disturbed by the roll cooling water, and in such a case, a clear still image of the rolling roll rotating while the roll cooling water is sprayed may not be obtained. Was.

Further, as described above, when a roll having a roll diameter different from that of the previous roll is set on the rolling stand by the roll exchange as described above, the position of the rotating shaft of the roll itself moves up and down, thereby reducing the rolling. The imaging position of the imaging device in the roll circumferential direction changes, which causes a shift between the imaging position on the rolling roll surface and the irradiation position of the illumination light, and a clear rolling roll surface still image that is bright and easy to see as a whole cannot be obtained. There was a problem.

Further, when the roll diameter changes due to the roll change, the distance between the imaging device and the roll surface changes,
There was a problem that defocus occurred and a clear still image of the roll surface could not be obtained.

Accordingly, an object of the present invention is to obtain a clear still image of the rolling roll surface of the rolling roll rotating while the cooling water is being sprayed, even when the roll diameter is changed. An object of the present invention is to provide an optical surface inspection device for a roll, which can accurately observe and inspect the surface condition of the roll.

[0015]

According to the first aspect of the present invention, there is provided a housing box movable in the longitudinal direction of a rolling roll, and pressurized water is applied to the surface of the rolling roll mounted on the housing box and rotating. A water column forming nozzle for forming a water column between the window portion of the front surface of the housing and the surface of the rolling roll, and is provided in the housing box, and irradiates illumination light to the surface of the rolling roll through the window portion and the water column. An illumination light source and an imaging device disposed in the housing box and imaging the image of the surface of the rolling roll being irradiated with the illumination light through the water column, while the roll cooling water rotates while being sprinkled. In a rolling roll optical surface inspection apparatus for obtaining a still image of the surface of a rolling roll, a variable for measuring the distance between the water column forming nozzle and the surface of the rolling roll. And a water column formation control means for positioning and controlling the housing box by moving the housing box toward a rolling roll at a position where an appropriate water column is formed based on an output signal of the displacement sensor. is there.

According to a second aspect of the present invention, there is provided a housing box movable in the roll longitudinal direction of a rolling roll, and pressurized water is jetted onto a surface of the rolling roll mounted on the housing box and rotating, thereby forming a front surface of the housing. A water column forming nozzle for forming a water column between a window portion and a rolling roll surface; an illumination light source disposed in the housing box, for irradiating illumination light to the rolling roll surface through the window portion and the water column; and the housing. An image pickup device disposed in the box, for taking an image of the surface of the roll on which the illuminating light is radiated, through the water column, the surface of the roll being rotating while the roll cooling water is being sprayed. In an optical surface inspection device for a rolling roll for obtaining an image, the imaging device is integrated with the illumination light source in a plane orthogonal to the axis of the rolling roll. A swingable camera / illumination light source angle adjusting mechanism, and measuring the brightness level of a plurality of points in the circumferential direction of the rolling roll on a still image of the surface of the rolling roll being irradiated with the irradiation light, and the brightness levels thereof are set in advance. Driving control of the camera / illumination light source angle adjustment mechanism so as to fall within the range, and a camera / illumination light source angle adjustment control means for adjusting and setting the target angle of the imaging device and the illumination light source with respect to the rolling roll. It is a feature.

According to a third aspect of the present invention, there is provided a housing box movable in the longitudinal direction of the rolling roll, and pressurized water is jetted onto the surface of the rotating rolling roll mounted on the housing box to rotate the housing box. A water column forming nozzle for forming a water column between a window portion and a rolling roll surface; an illumination light source disposed in the housing box, for irradiating illumination light to the rolling roll surface through the window portion and the water column; and the housing. An image pickup device disposed in the box, for taking an image of the surface of the roll on which the illuminating light is radiated, through the water column, the surface of the roll being rotating while the roll cooling water is being sprayed. In an optical surface inspection device for a rolling roll for obtaining an image, a camera position in which the imaging device and the illumination light source are integrally moved toward and away from the rolling roll. An adjusting mechanism, a visible laser light emitting device that irradiates a light spot with visible laser light to the roll surface, and irradiating the roll surface based on an image of the light spot illuminated on the roll surface obtained by the imaging device. And a defocus correction control means for driving and controlling the camera position adjusting mechanism so that the image of the light spot formed at the focal point position of the image pickup device is provided.

[0018]

In the optical surface inspection apparatus for a rolling roll according to the first aspect of the present invention, a water column is formed between a window in the front of the housing box and the surface of the rolling roll by a water column forming nozzle, and the roll cooling water rotates while being sprinkled. Irradiation light is radiated from the illumination light source in the housing box through the window and the water column on the surface of the rolling roll that is being lit, and an image of the surface of the rolling roll being irradiated with the radiated light is projected on the water column by an imaging device in the housing box. Observation / inspection of the surface condition of the rolling roll is performed by using the obtained still image of the rolling roll surface that is imaged through. In forming the water column by the water column forming nozzle, the distance between the water column forming nozzle and the surface of the rolling roll is measured by the displacement sensor, and the water column forming control unit forms an appropriate water column based on the output signal of the displacement sensor. At this position, the housing box provided with the water column forming nozzle is moved forward and backward toward the rolling roll and positioned. Thereby, even if the roll diameter of the rolling roll changes due to roll exchange or the like, the distance between the tip end of the water column forming nozzle and the surface of the rolling roll is kept at a preset value. Nothing.

In the optical roll surface inspection apparatus according to the second aspect of the present invention, a water column is formed between the window on the front surface of the housing box and the surface of the roll by the water column forming nozzle, and the roll cooling water is sprinkled. Irradiation light is radiated from the illumination light source in the housing box through the window and the water column to the surface of the rolling roll that is rotating, and an image of the roll surface irradiated with the irradiation light is imaged by an imaging device in the housing box. Observation / inspection of the surface condition of the rolling roll is performed using the obtained still image of the rolling roll surface imaged through the water column. Then, when an image of the surface of the rolling roll irradiated with the irradiation light is taken by the imaging device, the camera / illumination light source angle which can swing the imaging device together with the illumination light source in an orthogonal plane orthogonal to the axis of the rolling roll. An adjustment mechanism is provided for the camera
The illumination light source angle adjustment control unit measures the brightness levels of a plurality of points in the circumferential direction of the rolling roll on a still image of the surface of the rolling roll to which the irradiation light is applied, so that the brightness levels are within a preset range. Then, the camera / illumination light source angle adjusting mechanism is drive-controlled to adjust and set the target angles of the imaging device and the illumination light source with respect to the rolling roll in the circumferential direction of the rolling roll. Thus, even if the roll diameter of the rolling roll changes due to roll replacement or the like, the intersection between the optical axis of the imaging device and the optical axis of the illumination light source that performs oblique illumination is located almost on the surface of the rolling roll. Thus, a clear still image of the rolling roll surface which is bright and easy to see can be obtained.

Further, in the optical surface inspection apparatus for a rolling roll according to the third aspect of the present invention, a water column is formed between the window on the front surface of the housing box and the surface of the rolling roll by the water column forming nozzle, and the roll cooling water is sprinkled. Irradiation light is radiated from the illumination light source in the housing box through the window and the water column to the surface of the rolling roll that is rotating, and an image of the roll surface irradiated with the irradiation light is imaged by an imaging device in the housing box. Observation / inspection of the surface condition of the rolling roll is performed using the obtained still image of the rolling roll surface imaged through the water column. When an image of the surface of the rolling roll irradiated with the irradiation light is captured by the imaging device, a camera position adjustment mechanism that integrally moves the imaging device and the illumination light source toward the rolling roll is provided. When the light spot by the visible laser light is irradiated on the rolling roll surface by the light emitting device, the defocus correction control means, based on the image of the light spot irradiated on the rolling roll surface obtained by the imaging device,
The camera position adjusting mechanism is driven and controlled such that an image of the light spot irradiated on the surface of the rolling roll (reflected light of the light spot) forms an image at a focal point of an imaging device. Thereby, even if the roll diameter of the rolling roll changes due to roll replacement or the like, the defocus of the imaging device is corrected, and a clear rolling roll surface still image can be obtained.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
FIG. 1 is a schematic diagram illustrating the configuration of an optical surface inspection device for a rolling roll according to the present invention, and FIG. 2 is a schematic diagram illustrating the configuration of the optical surface inspection device when viewed from the side. The same or corresponding portions as those of the conventional rolling roll optical surface inspection apparatus shown in FIG. 8 are denoted by the same reference numerals as those in FIG. 8 and will not be described.

As shown in FIGS. 1 and 2, a support shaft 22 of a support bracket 21 is centered on a plate-like support base 20 provided in a housing box 5 arranged opposite to a roll W. A CCD camera 6 as an imaging device is provided so as to swing freely. As shown in FIG. 1, a visible laser light emitting device 24 and a xenon lamp 25 with a condenser lens 25a as a strobe-type illumination light source are mounted on the left and right sides near the tip of the CCD camera 6 by a mounting bracket 23, as shown in FIG. Each optical axis is arranged so as to intersect with the optical axis of the CCD camera 6. The xenon lamp 25 is attached to the CCD camera 6 by the attachment bracket 23 in a state where its optical axis crosses the optical axis of the CCD camera 6 at an angle θ in plan view. That is, the oblique illumination that illuminates the optical axis of the CCD camera 6 from an oblique direction can prevent the occurrence of halation due to the adverse effect of the regular reflection, and the angle θ is, for example, about 27 °. It is set to the degree. Condensing lens 2
The visible laser light-emitting device 24 having 4a is used to correct a later-described defocus of the CCD camera 6, and irradiates a circular light spot by a visible laser to the surface of the rolling roll W. is there.

A first motor 26 is fixed on the support base 20, and an eccentric cam 27 is provided on a drive shaft of the first motor 26, while a lever 28 is fixed on a rear end of the CCD camera 6. The eccentric cam 27 is provided with the coil spring 2
The lever 2 which is constantly pushed down by the lever 9
8 is in contact with the lower surface. Thereby, the first motor 26
When the eccentric cam 27 is rotated by the drive of, the CCD camera 6 swings around the support shaft 22 together with the xenon lamp 25 and the visible laser light emitting device 24 fixed to the mounting bracket 23, and is orthogonal to the axis of the rolling roll W. Swingable in a perpendicular plane.

The support bracket 21, the support shaft 22, the first motor 26, the eccentric cam 27, the lever 28 and the coil spring 29 make the CCD camera 6 integral with the xenon lamp 25 in an orthogonal plane perpendicular to the axis of the rolling roll W. This constitutes a camera / illumination light source angle adjustment mechanism that can swing.

The support base 20 is slidably provided on a linear slider 30 fixed in the housing box 5 so as to advance and retreat in the direction of the rolling roll W. A transfer screw 32 is screwed into a screw bracket 31 fixed to the lower rear surface of the support base 20, and the transfer screw 32 is rotated by a second motor 33, so that the support base 20 is rolled into a roll W
The apparatus such as the CCD camera 6 on the support base 20 can move forward and backward in the rolling roll W direction.

The support 20, the linear slider 30, the screw bracket 31, the transfer screw 32 and the second motor 33
Constitutes a camera position adjusting mechanism for integrally moving the CCD camera 6, the xenon lamp 25 and the visible laser light emitting device 24 toward the rolling roll W.

A window glass plate 5a, which is a window, is provided at a portion of the housing box 5 facing the rolling roll W.
A water column forming nozzle 8 is mounted on the front surface thereof. A pressure water supply pipe 8a is provided at the upper part of the water column forming nozzle 8,
In order to prevent the nozzle tip from colliding with the surface of the rolling roll and being damaged when the water column forming nozzle 8 is moved, a rubber elastic cylindrical body is fitted to the tip of the water column forming nozzle 8 so as to be fitted on the peripheral edge thereof. 34 are attached. The high-pressure water introduced from the pressurized water supply pipe 8a enters the water column forming nozzle 8, is guided by the elastic cylinder 34 from the water column forming nozzle tip port 8b, and jets out on the surface of the rolling roll W to form a water column.
As shown in FIG. 2, the elastic cylindrical body 34 can contact the rolling roll surface in a circumferential direction of the rolling roll in such a manner that the tip thereof flexibly responds to a change in the rolling roll surface having an arc shape. This helps to form the water column more reliably.

The housing box 5 is supported on a table 35 fixed to the end of the piston rod 3a of the air cylinder 3 constituting the moving device 4 by a guide rail and guide rollers (not shown) so as to be movable in the front-rear direction. I have. Then, on the front side of the housing box 5,
An eddy current type displacement sensor 36 as a non-contact type displacement sensor is provided with its sensor section facing the surface of the rolling roll W. A rack 37 protrudes from the rear end surface of the housing box 5, and a pinion 39 fixed to a drive shaft of a third motor 38 fixed to the table 35 meshes with the rack 37. . Thereby, the distance between the tip end 8b of the water column forming nozzle 8 and the surface of the rolling roll is measured by the eddy current type displacement sensor 36, and the third motor 38 based on the output signal of the eddy current type displacement sensor 36 indicating the measured value. To drive the water column forming nozzle tip port 8b
And the distance between the roll and the surface of the rolling roll can be maintained at a preset value.

The table 35, the rack 37, the third motor 38, the pinion 39, and the nozzle position control circuit 52, which will be described later, are provided at a position where a proper water column is formed based on the output signal of the eddy current displacement sensor 36. 5
Is formed toward the rolling roll W to form a water column forming control means for performing positioning control.

FIG. 3 is a block diagram showing an electric control system of the optical surface inspection apparatus shown in FIG. In FIG.
0 is control of the entire apparatus based on an external operation command signal,
This is a control device that performs a process of determining a luminance level in the camera / illumination light source angle adjustment control, a process of determining the presence or absence of defocus in the defocus correction control, and the like. The control device 50 includes a CPU (central processing unit), a ROM (read-only memory) storing and storing a control program, a RAM (randomly reading and writing memory) storing and storing control data and the like, and an input / output interface. And the like.

Reference numeral 51 denotes a signal processing device which receives an image pickup command signal and the like from the control device 50 and takes in and reads out an image signal of the CCD camera 6. 52 receives a positioning command signal from the control device 50, and drives and controls the third motor 38 for moving the housing box 5 on which the water column forming nozzle 8 is mounted to advance and retreat based on the output signal of the eddy current displacement sensor 36. This is a nozzle position control circuit.
The nozzle position control circuit 52 includes an interval distance setting device, an eddy current displacement sensor output amplifier, a comparator, a motor drive circuit, and the like.

Reference numeral 53 denotes a drive circuit for the first motor 26, and reference numeral 54 denotes a drive circuit for the second motor 33. 55 is the control device 5
The light source control device controls the lighting of the xenon lamp 25 in response to a flash command signal given in synchronization with the imaging command signal from 0. The light source control device 55 includes a light emitting power supply, a light emitting voltage adjusting circuit, a lighting (flash) trigger circuit, and the like. The visible laser light emitting device 24
Is configured to receive a light emission command signal from the control device 50.

The control device 50 and the first motor drive circuit 53 drive and control the above-described camera / illumination light source angle adjustment mechanism to adjust and set the target angles of the imaging device and the illumination light source with respect to the rolling roll. It constitutes a light source angle adjustment control means. Further, the control device 50 and the second motor drive circuit 54 constitute a defocus correction control unit that drives and controls the above-described camera position adjustment mechanism for correcting defocus.

Next, the operation of the thus configured apparatus will be described. When the roll exchange operation is completed, a new roll having been subjected to roll surface grinding is set as a rolling roll W on a rolling stand, and hot rolling is started while spraying roll cooling water. The feed screw shaft 1 is rotated by a motor (not shown) to move the moving block 2 to a position corresponding to the first inspection (observation) in the longitudinal direction of the rolling roll W. Next, the piston rod 3a of the air cylinder 3 is extended, and the housing box 5 equipped with the water column forming nozzle 8 is advanced toward the roll surface of the rolling roll W.

Here, the elongation stroke of the piston rod 3a is a predetermined constant value, and the roll diameter is different each time a new roll having a different degree of surface grinding is newly set on the rolling stand by replacing the roll. Next, the distance between the tip 8b of the water column forming nozzle and the roll surface changes. If the interval distance becomes larger than a preset value due to the change in the diameter of the rolling roll, the water column formed by the water column forming nozzle 8 is disturbed, and many bubbles are generated in the water column. Due to such turbulence of the water column, a clear still image of the rolling roll cannot be obtained, and the surface condition of the rolling roll cannot be accurately observed and inspected.

Therefore, upon receiving the positioning command signal given from the control device 50 after the operation of the air cylinder 3 is completed, the nozzle position control circuit 52
6, the distance between the water column forming nozzle tip port 8b and the roll surface is compared with a predetermined distance setting value for forming an appropriate water column, and the distance is determined by the distance distance setting. The third motor 38
Is driven to move the housing box 5 forward and backward by the engagement of the pinion 39 and the rack 37 for positioning.

Thus, even if a roll having a different diameter from the previous roll is set on the rolling stand by the roll change, the water column forming nozzle tip 8 can be used.
Since the distance between b and the roll surface is automatically adjusted so as to be a preset value capable of forming an appropriate water column, a stable water column free from disturbance such as generation of bubbles is formed by the water column forming nozzle 8. can do.

On the other hand, when a roll having a roll diameter different from that of the previous roll is set on the rolling stand by the roll exchange, as shown in FIG. As a result, the intersection between the optical axis of the CCD camera 6 and the optical axis of the xenon lamp 25 is no longer located on the surface of the rolling roll, and the imaging position of the CCD camera 6 on the surface of the rolling roll and the illumination light from the xenon lamp 25 are changed. , And a still image of the roll surface that is bright and easy to see cannot be obtained.

Therefore, after the water column forming nozzle 8 is positioned so as to form an appropriate water column as described above, the CCD camera for the roll W is then moved to obtain a still image of the entire roll surface which is bright and easy to see. The camera / illumination light source angle adjustment control for adjusting and setting the target angle of the xenon lamp 6 and the xenon lamp 25 is performed.

First, the control device 50 includes a light source control device 55
, The xenon lamp 25 is turned on for a short time (about 1 to 10 μs), and an imaging command signal is given to the signal processing device 51. Upon receiving the imaging command signal, the signal processing device 51 fetches a still image signal of the surface of the rolling roll from the CCD camera 6 in synchronization with the turning on of the xenon lamp 25. Then, the control device 50 includes a signal processing device 51
The still image signal is taken in.

FIG. 4 shows a CCD image pickup element (a plurality of light receiving elements arranged two-dimensionally) of a CCD camera 6 for measuring the brightness level of a still image of a rolling roll surface in camera / illumination light source angle adjustment control. FIG. 4 is a diagram for explaining a luminance level measurement point. In FIG. 4, three measurement points K _{1 to} K ₃ are set to measure the luminance level of a point along the rolling roll circumferential direction on a still image of the rolling roll surface irradiated with the irradiation light. is there. Measurement point K ₂ represents a part comprising a plurality of pixels at the center of the CCD image sensor of the CCD camera 6, the measurement points K ₁ is CCD
On the vertical center line CL passing through the center of the image sensor, a portion composed of a plurality of pixels at a position separated by a distance L above the measurement point K ₂ is shown. The measurement point K ₃ is a vertical center line of the CCD image sensor. It is on CL, the distance L from the measurement point K ₂ downward
3 shows a portion composed of a plurality of pixels at positions separated by only a distance.

Now, based on the still image signal fetched from the signal processing device 51, the control device 50 adjusts the luminance levels at the _three points K _{1 to} K ₃ on the still image in a predetermined range. Is determined. That, Q ₁ a (output corresponding to the brightness level of the pixel) luminance level of the measurement points K ₁ in the CCD image pickup device described above, the luminance level Q ₂ measurement points K _2, the luminance level of the measurement point K ₃ and Q _3, determines the luminance level lower limit value Q _MIN, when the luminance level upper limit and Q _MAX, based on the captured still image signal, whether the following relational expression is satisfied.

Q _MIN ≤ Q ₁ , Q ₂ , Q ₃ ≤ Q _MAX ...

As a result of the judgment, if the above relational expression is not satisfied, the control device 50 compares the luminance level Q ₁ with the luminance level Q _3, and if Q ₁ > Q ₃ , the first motor drive circuit A drive command signal is given to 53 to drive the first motor 26 to rotate the eccentric cam 27 by a predetermined rotation angle,
The intersection between the optical axis of the CCD camera 6 and the optical axis of the xenon lamp 25 is positioned higher than before the CCD camera 6. Next, the xenon lamp 25
Is turned on, a still image signal is read from the signal processing device 51, and it is determined whether or not the relational expression is satisfied based on the still image signal. Such an operation is repeated until the above relational expression is satisfied. Conversely, if the brightness level Q ₁ <the brightness level Q ₃ , the eccentric cam 27 is rotated by a predetermined rotation angle, and the optical axis of the CCD camera 6 and the optical axis of the xenon lamp 25 are shifted. The intersection of
What is necessary is just to position it below the CCD camera 6 before it. Specifically, the camera / illumination light source angle adjustment control by the first motor 26 adjusts the optical axis of the CCD camera 6 from horizontal to ± 3 ° with an accuracy of about ± 0.01 °.
The adjustment is made within the range of.

Even if a roll having a roll diameter different from that of the previous roll is set on the rolling stand by the roll exchange, the surface of the roll which is irradiated with the irradiation light by the xenon lamp 25 is thus kept stationary. The luminance levels of a plurality of points in the circumferential direction of the rolling roll on the image are measured, and C with respect to the rolling direction of the rolling roll W in the circumferential direction of the rolling roll is set so that the luminance levels fall within a preset range.
The aiming angles of the CD camera 6 and the xenon lamp 25 are adjusted and set so that the intersection of the optical axis of the CCD camera 6 and the optical axis of the xenon lamp 25 for oblique illumination is located almost on the surface of the rolling roll. Thus, a clear rolling roll surface still image that is bright and easy to see as a whole can be obtained.

Next, defocus correction control using the visible laser light emitting device 24 is performed. When a roll having a roll diameter different from that of the previous roll is set on the rolling stand by the roll exchange, the distance between the CCD camera 6 and the roll surface changes, that is, the CCD which is the focal point position of the CCD camera 6 is changed. The distance between the light receiving surface of the image sensor and the surface of the rolling roll changes, which causes a defocus.

Therefore, in order to eliminate the defocus, the control device 50 gives a light emission command signal to the visible laser light emitting device 24 to irradiate the surface of the rolling roll W with a circular light spot by the visible laser. Is given an imaging command signal. Signal processing device 51 upon receiving an imaging command signal
Captures, from the CCD camera 6, the image signal of the circular light spot irradiated (projected) on the surface of the rolling roll. Then, the control device 50 takes in the image signal of the circular light spot from the signal processing device 51. In the standard condition in which the distance between the surface of the roll and the tip 8b of the water column forming nozzle is maintained at a preset value for the roll having the standard roll diameter, the visible laser light emitting device 2 is set in advance.
Reference numeral 4 denotes a CCD which is adjusted in position so that the light condensing point of the light condensing lens 24a is positioned on the surface of the rolling roll.
The position of the camera 6 is adjusted so that the image formed by the light condensing point on the surface of the rolling roll forms an image on the light receiving surface of the CCD image sensor. As described above, the CCD camera 6, the xenon lamp 25, and the visible laser light emitting device 24 are provided such that their optical axes intersect at the same point.

FIG. 5 is a diagram for explaining the defocus correction control, and FIG. 6 is a diagram for explaining the defocus correction control. When a circular light spot is projected on the surface of the rolling roll, the focus is corrected. Light receiving area (number of light receiving pixels of the CCD image sensor) S _M received by the CCD image sensor when a shift occurs S _M
FIG. 4 is a diagram schematically illustrating a light receiving area (the number of light receiving pixels of the CCD image sensor) S _C received by the CCD image sensor when there is no defocus.

The control device 50 determines the presence or absence of defocus based on the circular light spot image signal received from the signal processing device 51. That is, the number of light receiving pixels by a circular light spot determined based on the circular light spot image signal is S, the number of light receiving pixels by a circular light spot when there is no defocus is S _C , and the degree of defocus is determined. Is set as ΔS, it is determined whether or not the following relational expression is satisfied.

| S−S _C | ≦ ΔS...

As a result of the determination, if the above relational expression is not satisfied, the control device 50 supplies a drive command signal to the second motor drive circuit 54 to drive the second motor 33 to drive the support base 20 by a predetermined distance. Is moved forward, for example. Next, the imaging command signal is again given to the signal processing device 51, and the circular light spot image signal is read from the signal processing device 51,
Based on the read circular light spot image signal,
It is determined whether or not the relational expression is satisfied. Note that |
If the value of S−S _C | is larger than the last time,
Next time, the CCD camera 6 is moved in the opposite direction to the previous time.

By performing such an operation until the above-mentioned relational expression is satisfied, even if the roll diameter of the rolling roll changes due to the roll change, the image of the rolling roll surface is changed to the in-focus position of the CCD camera 6. An image can be formed on the light receiving surface of the imaging element, and the occurrence of defocus can be eliminated. When the defocus correction control ends, the control device 50 gives a light emission stop signal to the visible laser light emitting device 25. Specifically, the support 20 can be moved within a range of about ± 5 mm with an accuracy of ± 0.01 mm.

When each control is completed in this way, at the first inspection position, the surface image of the rolling roll rotating while the roll cooling water is being sprayed is used as the xenon lamp 2.
An image is taken by the CCD camera 6 in synchronism with the lighting of 5, and a still image of the surface of the rolling roll is obtained. Thereafter, in the same manner as in the prior art, a still image of the roll surface is obtained at predetermined intervals in the longitudinal direction of the roll. Note that each of the above-described controls may be performed prior to imaging for each inspection position in the longitudinal direction of the rolling roll.

As a result, even if the diameter of the roll changes due to a roll change or the like, a stable water column can be formed without generating many bubbles inside, and the roll cooling water is rotating while being sprayed. A clear image of the surface of the rolling roll can be obtained clearly. Further, even if the diameter of the roll changes, the intersection of the optical axis of the CCD camera 6 and the optical axis of the xenon lamp 25 for oblique illumination can be located almost on the surface of the rolling roll, so that the whole is bright and easy to see. A still image of the roll surface can be obtained. Furthermore, even if the diameter of the roll changes, the defocus is corrected and an image of the surface of the rolling roll irradiated with the illumination light is formed on the light receiving surface of the CCD image pickup device, which is the focal point of the CCD camera 6. And a clear still image of the roll surface can be obtained.

In the above embodiment, in order to eliminate the defocus, the image of the surface of the rolling roll irradiated with the illuminating light (the reflected light from the surface of the rolling roll) is taken by the CCD camera 6.
In this case, the entire CCD camera 6 is moved forward and backward with respect to the rolling roll so as to form an image at the focal point of
FIG. 7 is a diagram illustrating another example of focusing by a CCD camera that is an imaging device.

As shown in FIG. 7, the visible laser light emitting device 6
High-brightness slit light irradiated from 0 through the cylindrical lens 60a is reflected on the surface of the rolling roll W, passes through the electric lens device 61, and is branched in two directions by the half mirror 62. The slit light passing through the half mirror 62 is guided to the CCD camera 63, while the slit light reflected by the half mirror 62 is transmitted to the focus detector 6.
The focus control device 65 analyzes the image and detects a defocus of the CCD camera 63. Based on the detection result, the driving device 66 is driven to drive the electric lens device 6.
The first inner cylinder 61a is moved so that the light reflected by the surface of the rolling roll and passing through the half mirror 62 forms an image on the light receiving surface of the image sensor of the CCD camera 63. After the focusing is completed in this way, the visible laser light emitting device 60
Is turned off, and then the xenon lamp 67 is turned on, and an image signal is taken in from the CCD camera 63 to the camera controller 68 in synchronization with the turning on.
In FIG. 7, reference numeral 61b denotes an outer cylinder of the electric lens device 61;
9 is a mounting bracket, 70 is a housing box, 7
1 is a water column forming nozzle, and 72 is a CRT display.

The apparatus shown in FIG. 7 performs focusing by an automatic focusing method based on the image of the surface of the rolling roll by the emission of the visible laser light emitting device.
Regarding focusing, when a xenon lamp as a normal illumination light source emits light, it may be possible to perform an automatic focus adjustment operation based on the imaging result. However, in such a system, the light emission of the xenon lamp is extremely short as 1 to 10 μs, and it is uncertain even if a focus shift is detected in the imaging result at the time of this illumination, and the same is observed at the next light emission. Since it is necessary to determine the suitability by performing the adjustment operation, it takes time to focus. In addition, the surface of the rolling roll is almost mirror-like, and the surface image does not have much light and dark, and a normal focus detector used in a camera or the like performs focus detection using the light and dark of the image. , It is difficult to apply to rolling rolls. For this reason,
In the above-described example, the surface of the rolling roll is illuminated (projected) with a slit light or a spot light having a high brightness and a clear brightness by a visible laser light emitting device.

[0058]

As described above, according to the rolling roll optical surface inspection apparatus of the present invention, an image of the surface of the rolling roll irradiated with the illumination light is imaged through the water column, and the roll cooling water is discharged. In an optical surface inspection apparatus that obtains a still image of the surface of a rotating rolling roll while being sprayed with water, even if the roll diameter is changed due to roll replacement or the like, the distance between the water column forming nozzle and the rolling roll surface is appropriate. Since it is configured to be a preset set value that can form a water column, a stable water column can be formed without generating a large number of bubbles inside, and the roll cooling water rotates while being sprinkled. It is possible to obtain a clear image of the rolling roll surface still image of the existing rolling roll. This makes it possible to accurately observe and inspect the surface condition of the rolling roll during rolling,
It is possible to accurately grasp the roll replacement time for preventing the occurrence of scale flaws or the like biting into the steel sheet.

According to the rolling roll optical surface inspection apparatus, even when the roll diameter changes due to a roll change or the like, the intersection between the optical axis of the image pickup device and the optical axis of the illumination light source is almost equal to the rolling roll surface. It is configured to be located in
It is possible to obtain a clear rolling roll surface still image that is bright and easy to see as a whole. This makes it possible to accurately observe and inspect the surface condition of the rolling roll during rolling, and to accurately grasp the roll replacement time for preventing the occurrence of scale flaws and the like being stuck in the steel sheet.

According to a third aspect of the present invention, the image of the surface of the roll to which the illumination light is irradiated is focused on the image pickup device even if the roll diameter is changed due to the roll change or the like. Therefore, a clear still image of the roll surface can be obtained. This makes it possible to accurately observe and inspect the surface condition of the rolling roll during rolling, and to accurately grasp the roll replacement time for preventing the occurrence of scale flaws and the like being stuck in the steel sheet.

[Brief description of the drawings]

FIG. 1 is a schematic configuration explanatory view showing the configuration of an optical surface inspection device for a rolling roll according to the present invention.

FIG. 2 is a schematic configuration explanatory view showing the configuration of the optical surface inspection apparatus shown in FIG. 1 as viewed from the side thereof.

FIG. 3 is a block diagram showing an electric control system of the optical surface inspection device shown in FIG.

FIG. 4 is a CCD image pickup device of a CCD camera (in which a large number of light receiving elements are two-dimensionally arranged) for measuring the luminance level of a still image of a rolling roll surface in the camera / illumination light source angle adjustment control according to the present invention. FIG. 6 is a diagram for explaining a luminance level measurement point in FIG.

FIG. 5 is a diagram for explaining defocus correction control according to the present invention.

FIG. 6 is a diagram for explaining the defocus correction control according to the present invention, in which when a circular light spot is projected on the surface of a rolling roll, the CCD is defocused;
FIG. 4 is a diagram schematically showing a light receiving area (number of light receiving pixels of a CCD image sensor) S _M received by the image sensor and a light receiving area S _C received by the CCD image sensor when there is no defocus.

FIG. 7 is a diagram illustrating another example of focusing by a CCD camera that is an imaging device.

FIG. 8 is a configuration explanatory view showing a configuration of a conventional rolling roll optical surface inspection apparatus.

FIG. 9 is a diagram for explaining a state of roll banding generated on a surface of a work roll (rolling roll).

FIG. 10 is a diagram in which an example of a surface still image of a rolling roll is sketched.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Feed screw shaft 2 ... Moving block 3 ... Air cylinder 4 ... Moving device 5 ... Housing box 6 ... CCD
Camera 8: Water column forming nozzle 8a: Pressure water supply pipe 8
b: water column forming nozzle tip opening 10: frame memory 1
1 CRT display 12 Image printer 2
0: support base 21: support bracket 22: support shaft 2
3. Mounting bracket 24. Visible laser light emitting device 2.
4a: Condensing lens 25: Xenon lamp 25a: Condensing lens 26: First motor 27: Eccentric cam 28:
Lever 29: Coil spring 30: Linear slider 3
DESCRIPTION OF SYMBOLS 1 ... Screw bracket 32 ... Transfer screw 33 ... 2nd motor 34 ... Elastic cylinder 35 ... Table 36 ... Eddy current displacement sensor 37 ... Rack 38 ... 3rd motor 39 ...
Pinion 50 ... Control device 51 ... Signal processing device 52
... Nozzle position control circuit 53 ... First motor drive circuit 5
4: Second motor drive circuit 55: Light source control device W: Rolling roll

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Seiichi Hutsuki 1 Kanazawacho, Kakogawa City, Hyogo Prefecture Kobe Steel Works Kakogawa Works (72) Inventor Shuzo Tsutsumi 1 Kanazawacho, Kakogawa City, Hyogo Co., Ltd. Kobe Steel Kakogawa Works (72) Inventor Politics Inoue Politics 1 Kanazawacho, Kakogawa City, Hyogo Prefecture Kobe Steel Works Kakogawa Works (56) References JP-A-5-10888 (JP, A) JP-A-6- 186005 (JP, A) JP-A-6-138044 (JP, A) JP-A-59-174204 (JP, A) JP-A-5-265559 (JP, A)

Claims (3)

(57) [Claims] 1. A housing box movable in the longitudinal direction of a rolling roll, and pressurized water is jetted onto the surface of the rotating rolling roll mounted on the housing box to rotate the rolling roll. A water column forming nozzle for forming a water column between surfaces; an illumination light source disposed in the housing box; and an illumination light source for irradiating illumination light through the window and the water column to a rolling roll surface; and an illumination light source disposed in the housing box. And an imaging device for capturing an image of the surface of the rolling roll irradiated with the illumination light through the water column, and obtaining a surface still image of the rolling roll rotating while the roll cooling water is sprayed. An optical surface inspection apparatus according to claim 1, wherein a displacement sensor for measuring a distance between the water column forming nozzle and the surface of the rolling roll, and an output of the displacement sensor Water column forming control means and the optical surface inspection device of the rolling rolls, characterized in that a the advanced and retracted positions controlled toward the housing box rolling rolls positioned to form a proper water column on the basis of the issue. 2. A housing box which is movable in the longitudinal direction of the rolling roll, and pressurized water is jetted onto the surface of the rotating rolling roll which is mounted on the housing box and is rotated. A water column forming nozzle for forming a water column between surfaces; an illumination light source disposed in the housing box; and an illumination light source for irradiating illumination light through the window and the water column to a rolling roll surface; and an illumination light source disposed in the housing box. And an imaging device for capturing an image of the surface of the rolling roll irradiated with the illumination light through the water column, and obtaining a surface still image of the rolling roll rotating while the roll cooling water is sprayed. The optical surface inspection apparatus according to claim 1, wherein the imaging device is integrated with the illumination light source so as to swing in a plane orthogonal to the axis of the rolling roll. An illumination light source angle adjusting mechanism, and measuring the brightness levels of a plurality of points in the circumferential direction of the rolling roll on a still image of the surface of the rolling roll being irradiated with the irradiation light, so that the brightness levels are within a preset range. Rolling roll provided with a camera / illumination light source angle adjustment control means for driving and controlling the camera / illumination light source angle adjusting mechanism to adjust and set an image pickup device and an aim angle of the illumination light source with respect to the rolling roll. Optical surface inspection equipment. 3. A housing box movable in the roll longitudinal direction of the rolling roll, and pressurized water is jetted onto the surface of the rotating rolling roll mounted on the housing box, and a window on the front surface of the housing and the rolling roll. A water column forming nozzle for forming a water column between surfaces; an illumination light source disposed in the housing box; and an illumination light source for irradiating illumination light through the window and the water column to a rolling roll surface; and an illumination light source disposed in the housing box. And an imaging device for capturing an image of the surface of the rolling roll irradiated with the illumination light through the water column, and obtaining a surface still image of the rolling roll rotating while the roll cooling water is sprayed. In the optical surface inspection apparatus of the above, a camera position adjustment mechanism for integrally moving the imaging device and the illumination light source toward a rolling roll, A visible laser light emitting device that irradiates a light spot with visible laser light on the roll surface, and the light spot illuminated on the roll surface based on an image of the light spot illuminated on the roll surface obtained by an imaging device An optical surface inspection device for a rolling roll, further comprising: a defocus correction control unit that drives and controls the camera position adjustment mechanism so that the image of (i) is formed at a focal point of the imaging device.