JP2502442B2 - Rolling roll optical surface inspection system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention obtains a still image of the surface of a rolling roll, which is rotating while water is being sprinkled with the cooling water in a rolling process of a steel plate, by capturing an image of the surface (peripheral surface) of the rolling roll. , The surface condition of the rolling roll was observed and inspected for the purpose of grasping the roll replacement timing in order to prevent the occurrence of bite scale flaws etc. due to the roughening of the rolling roll on the steel plate. The present invention relates to an optical surface inspection device.

[0002]

2. Description of the Related Art A black scale is formed on a surface of a work roll (rolling roll) of a front stand in a hot-rolling mill for steel plates during rolling. Turtle-shaped minute cracks are formed on this black skin, and depending on the rolling conditions, this black skin peels off and crater-like depressions are formed on the roll surface in the form of strips along its circumferential direction, as shown in Fig. 3. However, the skin becomes rough, which is called roll banding. When a work roll having rough skin such as roll banding is used for rolling, the portion to which the dents are transferred is pressed by the work roll of the latter stand, and biting scale flaws are generated in the steel plate.

Therefore, the finish rolling machine is appropriately stopped, the work roll is pulled out from the stand, and the operator directly conducts a visual inspection of the roll surface, and when there is rough skin which causes scale defects such as roll banding, Alternatively, when the skin is rough and there is a possibility of roll banding, the rolls are replaced. Such inspection by direct visual inspection by the operator requires a lot of time and labor for removing and assembling the work roll after each inspection, and also requires warming up of the roll when restarting the rolling operation, which results in productivity increase. It had the drawback of causing a drop.

Therefore, in order to solve the above-mentioned drawbacks, the present applicant first obtained a static image of the surface of a rolling roll which was rotating while the cooling water for the roll was being sprayed, and rolled the static image of the surface of the rolling roll. We have proposed an optical surface inspection device for rolling rolls that enables observation and inspection of the surface condition of the rolls (Japanese Patent Application No. 3-165648).

As shown in FIG. 2 of the construction of the conventional optical surface inspection apparatus, the moving apparatus 4, the housing box 5 having a window portion on the side facing the peripheral surface of the rolling roll W, the housing box. A CCD camera 6 as a television camera (industrial video camera) arranged in 5, an annular xenon lamp 7 as a strobe illumination light source in the housing box 5, and a front surface of the housing box 5. It is composed of 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 printer 12 connected to the control device 9 is used for making a hard copy of a rolling roll surface still image.

More specifically, in the hot rolling process of steel sheet, the rolling roll (work roll) of the second stage finishing stand F2 and the rolling roll (not shown) of the next stage finishing stand F3 of the hot finishing rolling mill are used. A feed screw shaft 1 provided in parallel with the longitudinal direction (roll shaft direction) of the rolling roll W and rotated in the forward and reverse directions by a motor (not shown), and the feed screw shaft 1
A moving device 4 including a moving block 2 moved along the longitudinal direction of the rolling roll W in accordance with the rotation of the moving roll W, and an air cylinder 3 provided 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 a front surface facing the peripheral surface of the rolling roll W is attached to a tip end portion of a piston rod of an air cylinder 3 of a moving device 4. ing. The CCD camera 6 arranged in the housing box 5 is a two-dimensional array of CCDs (Charge Coupled Devic).
e) An image pickup device is used, and in order to prevent image blurring due to vibration of the rolling roll W, a lens system with a large numerical aperture and a long focal length and a deep focal depth is provided using a plurality of lenses. ing.

As shown in the figure, the water column forming nozzle 8 has a water ejection port communicating with the window glass plate 5a of the housing box 5, and when the pressurized water is supplied, the window glass plate 5a.
And a surface of the rolling roll W that is rotating while the roll cooling water is being sprinkled. This prevents the window glass plate 5a from being contaminated by the roll cooling water containing dirt, and prevents the rolling roll surface static image from becoming unclear. The cylindrical water column forming nozzle 8 is made of acrylic resin that allows light to pass through and has transparency, and is attached to the front surface of the housing box 5 through a pressure water supply pipe 8a to supply a supply source (not shown). Water pressurized from is introduced inside.

The controller 9 controls the inspection start signal S1 from the outside.
In response to this, the annular xenon lamp 7 is turned on in synchronization with the vertical synchronizing signal of the CCD camera 6, and the roll surface still image signal from the CCD camera 6 is stored in the frame memory.
Captured in 10 and receiving display command signal S2, frame memory
This is a device for controlling the roll surface still image signal stored (stored) in the CRT display 11 to the CRT display 11. The control device 9, the frame memory 10, the CRT display 11 and the printer 12 are arranged in the examination room.

In the optical surface inspection apparatus having the above-described structure, the housing box 5 in which the annular xenon lamp 7 and the CCD camera 6 are arranged is arranged at a predetermined inspection position in the longitudinal direction of the rolling roll W. When it is positioned at, the control device 9 synchronously controls the synchronization signal of the CCD camera 6 and the lighting of the annular xenon lamp 7. Illumination light from the annular xenon lamp 7 is applied to the surface of the rolling roll through the window glass plate 5a and the water column by the water column forming nozzle 8. The CCD camera 6 is a window glass plate 5a
Also, an image of the surface of the rolling roll W that is rotating while the roll cooling water is being sprinkled is taken through the water column, and a static image signal of that roll surface is output. The roll surface still image signal from the CCD camera 6 is stored in the frame memory 10
Stored in. 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 operation of the inspector after the image pickup of the surface of the rolling roll is completed, the still image signal of the roll surface stored in the frame memory 10 is changed according to the image pickup position. It is sequentially taken out for each screen and displayed on the CRT display 11 as a still image. The inspector observes the surface state of the rolling roll by the still image displayed on the monitor, and inspects the presence or absence of rough skin and the degree of rough skin. FIG. 4 is a sketch of an example of a static image of the surface of the rolling roll, in which the turtle shell-like fine cracks (shown in (a) of FIG. 4) on the black skin of the surface of the rolling roll are peeled off. The state in which roll banding has occurred (shown in FIG. 4B) can be known.

[0011]

However, in the above-mentioned conventional optical surface inspection apparatus, the light emitted by the inter-electrode discharge of the annular xenon lamp as the strobe illumination light source is applied to the surface of the rolling roll. Therefore, since the position of the discharge point between the electrodes changes with each discharge, there is a drawback that the static image of the surface of the rolling roll obtained by imaging may be difficult to see due to uneven brightness. Further, since the television camera and the xenon lamp are arranged together in the housing box, there is a drawback that image noise such as image flicker due to high voltage discharge of the xenon lamp is likely to occur.

According to the present invention, a stroboscopic illumination light source is provided outside a housing box in which a television camera is provided,
The light emitted from the strobe illumination light source and diffused by the light diffusing plate is guided into the housing box by the optical fiber to illuminate the surface of the rolling roll as illumination light, eliminating the above-mentioned conventional defects and making the light distribution uniform. An optical surface inspection of the rolling roll that enables to obtain a uniformly bright and clear still image of the rolling roll surface without unevenness in brightness and to eliminate image noise due to high voltage discharge of the strobe illumination light source. The purpose is to provide a device.

[0013]

In order to achieve the above object, an optical surface inspection device for a rolling roll according to the present invention has a window and a housing that is movable in the rolling longitudinal direction of the rolling roll. A box, a water column forming nozzle mounted on the housing box to form a water column between the front surface of the window and the surface of the rolling roll by ejecting pressurized water toward the surface of the rolling roll, and the housing box. A stroboscopic illumination light source that irradiates the surface of the rolling roll with illumination light through a window, and a television camera that is disposed in the housing box and that captures an image of the surface of the rolling roll in synchronization with lighting of the stroboscopic illumination light source. Provided, the image of the surface of the rolling roll which is rotating while the roll cooling water is sprinkled, is imaged through the water column by the television camera, In an optical surface inspection device for a rolling roll for obtaining a static image of the surface of the rolling roll, a parabolic reflector is provided outside the housing box, and the strobe is provided at the focal position of the parabolic reflector. An illumination light source is provided, and further in front of the parabolic reflector, a condenser lens for condensing the light emitted from the strobe illumination light source and reflected by the parabolic reflector, and the condenser lens. And a light diffusing plate for imparting light diffusing property to the light from the lens for use, and a plurality of optical fibers for guiding the light from the light diffusing plate into the housing box as illumination light for irradiating the surface of the rolling roll. It is characterized by that.

[0014]

In the optical surface inspection device for a rolling roll according to the present invention, the stroboscopic illumination light source is arranged at the focal position of the parabolic reflector arranged outside the housing box. The light emitted from the strobe illumination light source is reflected by the parabolic reflector to become parallel light rays, most of which pass through the condenser lens, and are then diffused by a diffuser plate made of frosted glass or the like. Distribution is made uniform. In this way, the light emitted from the stroboscopic illumination light source and having the light diffused by the diffuser plate to make the light distribution uniform is guided into the housing box by the optical fiber consisting of a large number of lights, and the illumination light is illuminated on the surface of the rolling roll. Will be irradiated as. This makes it possible to obtain a uniformly bright and clear still image of the surface of the rolling roll without uneven brightness. Also, since the strobe illumination light source is arranged outside the housing box away from the TV camera,
Image noise due to high voltage discharge of the strobe lighting light source can be eliminated.

[0015]

An embodiment of the present invention will be described below. FIG. 1 is a structural explanatory view showing the structure of an optical surface inspection device for a rolling roll according to an embodiment of the present invention. Here, the same or corresponding portions as those of the conventional optical surface inspection device for a rolling roll shown in FIG. 2 described above are denoted by the same reference numerals as those in FIG. 2, and description thereof is omitted, and only different points will be described. .

As shown in FIG. 1, the CCD camera 6 is provided inside.
A parabolic reflecting mirror 13 is arranged outside the housing box 5 in which is arranged, and a xenon lamp 14 as a strobe illumination light source is arranged at the focal position of the parabolic reflecting mirror 13. Reference numeral 15 is a high voltage control unit of the xenon lamp 14.

In front of the parabolic reflector 13, the reflector 13
From the side, a biconvex condenser lens 16 and a diffuser plate 17 made of frosted glass are provided coaxially in this order from the side, and further, a light receiving end of an optical fiber 18 made up of a plurality of optical fibers 18 near the focal point on the front side of the condenser lens 16. Are arranged. The optical output end of the optical fiber 18 in which a large number of fibers are bundled is arranged annularly so as to face the window glass plate 5a so as to surround the camera lens of the CCD camera 6 in the housing box 5, as shown in the figure. ing.

Next, the operation of the optical surface inspection apparatus having the above-mentioned structure will be described. The light emitted from the xenon lamp 14 is
After being reflected by the parabolic reflector 13 to become parallel light rays, most of them pass through the condenser lens 16, and then the diffuser plate 17 imparts a light diffusing property to make the light distribution uniform. In this way, the light emitted from the xenon lamp 14 and having the light diffused by the light diffusing plate 17 to have a uniform light distribution is guided into the housing box 5 by the optical fiber 18, and is rotated while the roll cooling water is being sprayed. Rolling roll W
An image of the surface of the rolling roll W is captured by the CCD camera 6 in a state where the surface of the rolling roll W is illuminated with the illumination light.

As a result, even if the position of the discharge point between the electrodes of the xenon lamp 14 changes with each discharge, it is possible to obtain a uniformly bright and clear still image of the surface of the rolling roll without uneven brightness. Further, since the xenon lamp 14 is arranged outside the housing box 5 in which the CCD camera 6 is arranged, it is possible to eliminate image noise due to high voltage discharge of the xenon lamp 14.

[0020]

As described above, according to the optical surface inspection device for a rolling roll according to the present invention, the television camera is arranged inside the housing box having the window portion and the front surface of the window portion is provided in the housing box. A water column forming nozzle for forming a water column between the surface of the rolling roll and the surface of the rolling roll that is rotating while the cooling water is being sprinkled, and the illumination light is rolled through the window of the housing box. In an optical surface inspection apparatus, which captures an image of the surface of a rolling roll by a television camera in synchronism with lighting of a strobe illumination light source for irradiating the surface, and obtains a static image of the surface of the rolling roll, the strobe illumination light source is provided outside the housing box. Is placed away from the TV camera, and the light is emitted from the strobe illumination light source and diffused by the diffuser plate. The light in uniform, guided by an optical fiber comprising a large number into the box,
Since the surface of the rolling roll is irradiated with illumination light, even if the discharge point position between the electrodes of the strobe illumination light source changes with each discharge, there is a uniform bright and clear rolling with no uneven brightness. It is possible to obtain a static image of the roll surface and eliminate image noise due to high voltage discharge of the strobe illumination light source. As a result, it is possible to accurately know the presence or absence of rough skin and the degree of rough skin of the rolling roll that is rotating online while the roll cooling water is sprinkled.
It is possible to accurately grasp the roll replacement timing to prevent the occurrence of bite scale flaws etc. on the steel sheet due to the roughening of the rolling roll, and to contribute to the prevention of bite scale flaws of the steel sheet in the hot rolling process of the steel sheet. You can Ma
In addition, this optical surface inspection device can be brought online during rolling.
-Line rolling that corrects and grinds the surface of rolling rolls
By installing in a hot rolling mill equipped with a liner device
Accurately observe the surface grinding state of the rolling roll.
And can be corrected by the online roll grinder device
It can contribute to the improvement of grinding accuracy.

[Brief description of drawings]

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

FIG. 2 is a configuration explanatory view showing a configuration of a conventional optical surface inspection device for a rolling roll.

FIG. 3 is a diagram for explaining how roll banding occurs on the surface of a rolling roll.

FIG. 4 is a diagram sketching an example of a still image obtained by capturing an image of the surface of a rolling roll, in which (a) shows fine hexagonal cracks formed on the black skin of the surface of the rolling roll. (B) shows roll banding in which the black skin is peeled off.

[Explanation of symbols]

1 ... Feed screw shaft 2 ... Movement block 3 ... Air cylinder 4 ... Movement device 5 ... Housing box 5a ... Window glass plate 6 ... CCD camera 8 ... Water column forming nozzle 9 ... Control device 10 ... Frame memory 11 ... CRT display 12 ... Printer 13 ... Parabolic reflector 14 ... Xenon lamp 15 ... High-voltage control unit 16 ... Focusing lens 17 ... Diffusing plate (frosted glass plate) 18 ... Optical fiber W ...
Rolling roll

Claims (1)

(57) [Claims] 1. A housing box having a window part, which is movable in a roll longitudinal direction of a rolling roll, and a housing box which is mounted on the housing box and jets pressurized water toward the surface of the rolling roll. A water column forming nozzle for forming a water column between the front surface and the surface of the rolling roll,
A stroboscopic illumination light source that irradiates the surface of the rolling roll with illumination light through the window of the housing box, and an image of the surface of the rolling roll, which is disposed in the housing box, is imaged in synchronization with lighting of the stroboscopic illumination light source. A television camera is provided, and an image of the surface of the rolling roll that is rotating while the roll cooling water is being sprinkled is imaged through the water column by the television camera, so that the rolling roll surface still image is obtained. In the optical surface inspection apparatus, a parabolic reflector is provided outside the housing box, and the strobe illumination light source is provided at the focal position of the parabolic reflector. In front of the mirror, a condenser lens for condensing the light emitted from the strobe illumination light source and reflected by the parabolic reflector, and this condenser lens And a light diffusing plate for imparting a light diffusing property to the light from the light diffusing plate, and a plurality of optical fibers that guide the light from the light diffusing plate into the housing box as illumination light that is applied to the surface of the rolling roll. An optical surface inspection device for a rolling roll, which is characterized in that