JP3110241B2 - Roll flaw detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting roll flaws in a rolling mill online.

[0002]

2. Description of the Related Art In the rolling of a metal material, if any defect such as chipping or sticking of foreign matter occurs on a roll during a rolling operation for some reason, the defect on the surface of the roll is transferred to the rolled material and defective rolling is performed. Will generate material. Conventionally, roll flaws are found by a method in which an operator visually monitors the rolled material, stops the line by finding flaws in the rolled material, and inspects the roll.

[0003]

In the conventional method of detecting roll flaws, it is inevitable that a considerable defective rolled material is generated until a flaw in the rolled material is found and the line is stopped. In addition, it took time to inspect the rolls of each rolling stand after the line was stopped and to find a roll with a flaw, and thus the line stop time was long. The present invention has been made in view of the above circumstances, and provides a roll flaw detection method capable of finding flaws generated in a roll of a rolling mill online in a short time, thereby reducing defective rolled material and reducing the number of lines. The purpose is to reduce the stop time.

[0004]

According to the present invention, there is provided a method for detecting roll flaws in a rolling mill provided with a detection sensor for detecting a profile of a roll. The roll surface wave echo is continuously detected by scanning continuously in the axial direction, and the roll surface shape is determined based on the continuously detected roll surface wave echo .
Determine the height of the virtual surface based on the surface height of the area, and
Compare the height of the surface with the detected height to determine the magnitude of the detected value.
It is characterized in that the roll surface flaw is detected by the judgment .

[0005]

[Action] The tendency of defects such as chipping of the roll surface and burn-in of foreign matter to appear on the roll surface shape is verified in advance, and the amount of change in the roll surface shape that requires a roll change is determined as a reference value. A roll surface flaw is detected stepwise by detecting a sudden change from a linear approximation of the front and rear roll surface shapes or a change beyond a reference value at a shape change point.

[0006]

FIG. 1 is a plan view of a main part of a rolling mill for implementing a method for detecting a roll flaw according to an embodiment of the present invention.

In the drawing, reference numeral 1 denotes a work roll, and a rolling machine is provided with a support frame 2 along the work roll 1. A sensor mounting base (base) 5 is mounted on the support frame 2 via a guide rail 3 and a guide piece 4.
Are reciprocally supported, and the gantry 5 is reciprocated along the work roll 1 by the driving device 6. Six sensors 7a to 7f for roll profile detection are attached to the gantry 5 along the work roll 1, and the sensors 7a to 7f
Are arranged at regular intervals so as to face the surface of the work roll 1. Further, the gantry 5 is reciprocated by the driving device 6 by the distance between the sensors 7a to 7f. Sensor 7a
7f are connected to a measuring device 8, and the measuring device 8 detects a flaw on the surface of the work roll 1 based on signals from the sensors 7a to 7f.

The principle of the method for detecting roll flaws according to one embodiment of the present invention will be described with reference to FIGS. FIG. 2 shows the principle of detecting roll flaws, and FIG. 3 shows criteria for determining roll flaws.

In this embodiment, the sensor 7a shown in FIG.
, The surface of the work roll 1 is continuously scanned by the sensors 7a to 7f while the gantry 5 is reciprocated by the driving device 6 by the distance between the sensors 7a to 7f. The echo is taken into the measuring device 8.

In FIG. 2, R is the surface shape of the work roll 1 determined by the surface wave echo of the work roll 1 taken into the measuring device 8. On the surface shape R of the work roll 1, flaws of the surface projections appear as R1 portions, and on the surface shape R of the work roll 1, flaws due to surface chipping appear as R2 portions. The tendency of the flaw appearing on the surface shape R of the work roll 1 is verified and grasped in advance. In FIG. 2, ΔR is a reference value of the size (height or depth) of the flaw requiring replacement of the work roll 1 by this verification.

Next, the determination of the size of the flaw will be described by taking the R1 part which is a flaw of the surface projection as an example. When a flaw R1 (variable portion R1) of the surface protrusion is detected on the surface shape R of the work roll 1 (detection portion) , it is continuous to an area δ including the variation portion R1 separated by a set fixed small distance. From the approximate value of the height of the surface shape R of the plurality of other sections δ, the height of the virtual surface r of the work roll 1 in the section δ including the change portion R1 is obtained,
The size of the flaw is determined by comparing the absolute value | Δy | of the difference between the height of the virtual surface r and the detected height of the changing portion R1 with the reference value ΔR.

The work roll 1 is detected by the sensors 7a to 7f.
Are detected as the detected value ya of the changing portion R1 and the detected values ya1 and ya2 of the two sections δ adjacent thereto, and the height of the virtual surface r of the section δ including the changing portion R1. ya3 is obtained by the following equation. ya3 = (ya1 + ya2) / 2

Further, the height ± Δy of the changing portion R1 from the virtual surface r is obtained by the following equation. ± Δy = ya−ya3

The height ± Δy obtained here is the height of the change portion R1 (flaw) to be determined, and the height ± Δy is hereinafter referred to as a determination value. In addition, the code | symbol 10 in FIG.
Reference numeral 7f denotes a measurement reference point, 11 denotes a moving direction of the sensors 7a to 7f, 12 denotes a measurement signal wave of the sensors 7a to 7f, and 13 denotes a measurement point for each section δ.

The determination of the change portion R1 captured on the surface shape R of the work roll 1 can be performed based on a table shown in FIG. 3 as an example. FIG. 3 shows the determination values ± Δy obtained by the calculation unit of the measuring device 8 in the horizontal column, Δy =
(−), Δy = (+), Δy = 0, and |
Δy | ≧ ΔR, | Δy | <ΔR, and the respective situations and necessary treatments are displayed.

That is, in FIG. 3, under the condition of | Δy | ≧ ΔR, when Δy = (−), foreign matter seizure occurs, the work roll needs to be rearranged, and when Δy = (+), the surface rolls. There is chipped flaws, large degree, and work roll replacement is required. Under the condition of | Δy | <ΔR, Δy =
In the case of (-), foreign matter seizure occurs and the work roll needs to be ground, and when Δy = (+), the surface has a chipped surface and the work roll needs to be ground. Also, Δy
If = 0, it is normal.

The configuration of the measuring device 8 will be described with reference to FIG. FIG. 4 shows a configuration block of the measuring apparatus. The measuring device 8 is a work roll 1 by sensors 7a to 7f.
Roll 1 detected by continuous scanning of surface
A calculation unit 21 that obtains a judgment target value Δy for each change part R1 (change part R2) based on the surface shape R of the above, and a judgment target value Δy sent from the calculation unit 21 is evaluated based on the criteria shown in FIG. It is composed of a judgment calculation unit 22 and a display output unit 23 of the judgment result by the judgment calculation unit 22. Then, the determination result is transmitted from the display output unit 23 to the related equipment such as the rolling mill control system 24, and a necessary corresponding operation is performed.

An operation procedure for detecting a roll flaw will be described with reference to FIG. FIG. 5 shows a control flowchart of the roll flaw detection method. During the rolling or non-rolling of the rolling mill, continuous scanning of the surface of the work roll 1 by the sensors 7a to 7f is started, and the surface wave echo of the continuous work roll 1, that is, the surface shape R of the work roll 1 is detected. . Next, the changing portion R1 (R
When 2) is detected, the determination value ± Δy is calculated by the calculation unit 21.
Is determined by the determination calculation unit 22, and a comparison determination calculation of the type of the determination value ± Δy, the absolute value | Δy | and the reference value ΔR is performed, and the result is displayed on the display output unit 23 as a situation and a necessary action. You. At the same time, an instruction signal is transmitted to the related equipment such as the rolling mill control system 24, so that the online roll grinding,
Alternatively, necessary measures such as stopping the line and changing the work roll are performed.

Therefore, by performing the above-described roll flaw detection method, flaws generated on the surface of the work roll 1 during rolling or non-rolling of the rolling mill can be found online for each rolling mill in a short time. Can reduce the time to stop the line, reduce the occurrence of defective rolling products, and at the same time, reduce the time for identifying the location of the occurrence of roll flaws and the necessary roll processing, and reduce the line stop time. Can be reduced.

[0020]

According to the roll flaw detection method of the present invention, a roll flaw detection method for a rolling mill provided with a detection sensor for detecting the profile of a roll is a method for detecting a roll flaw by continuously scanning the detection sensor in the axial direction of the roll. Wave echo is continuously detected, the roll surface shape is determined based on the continuously detected roll surface wave echo, and the area including the detection unit is
Virtual surface height based on the surface height of several consecutive areas
Height and compare the height of the virtual surface with the detected height.
Since the flaws on the roll surface are detected by judging the magnitude of the output value , flaws occurring on the rolls of the rolling mill can be found online in a short time, reducing the number of defective rolled materials and reducing the line. It is possible to reduce the stop time.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a rolling mill that implements a method for detecting a roll flaw according to one embodiment of the present invention.

FIG. 2 is a diagram illustrating the principle of detecting roll flaws.

FIG. 3 is a table showing criteria for determining roll flaws.

FIG. 4 is a configuration block diagram of a measuring device.

FIG. 5 is a control flowchart of a roll flaw detection method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Work roll 2 Support frame 3 Guide rail 4 Guide piece 5 Sensor mounting stand (stand) 6 Driving device 7a-7f Sensor 8 Measuring device 10 Measurement reference point 11 Moving direction 12 Measurement signal wave 13 Measurement point 21 Calculation unit 22 Judgment calculation unit 23 Display output unit 24 Rolling mill control system ΔR reference value R1, R1 changing part δ area r Virtual surface ya, ya1, ya2 Detected value ± Δy Judgment value

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor: Tamotsu Kawakami 1 Fujimachi, Hirohata-ku, Himeji-shi, Hyogo Nippon Steel Corporation Hirohata Works (56) References JP-A-63-261157 (JP, A ) JS60-118956 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 29/00-29/28

Claims (1)

(57) [Claims] In a method for detecting a roll flaw in a rolling mill provided with a detection sensor for detecting a profile of a roll, the detection sensor is continuously scanned in the axial direction of the roll to continuously detect a roll surface wave echo and continuously detect the echo. The roll surface shape is determined based on the roll surface wave echo, and the surface heights of multiple areas that are continuous with the area containing the detection unit
The height of the virtual surface is determined based on the
To determine the magnitude of the detected value by comparing the heights issued
A method for detecting roll flaws, which comprises detecting flaws on the roll surface.