JPH04258309A - Operation method of brush-type plate surface cleaning equipment for steel strips - Google Patents

Abstract

PURPOSE:To prolong the life of a brush of a brush type plate surface washer for a steel strip equipped on the inlet side of a cold rolling mill and to efficiently remove a hard foreign matter stuck on the surface of the steel strip. CONSTITUTION:In the operating method of brush type plate surface washer 3 for the steel strip 1 equipped on the inlet side of a cold rolling mill 2, only a prescribed area before and behind a welded point of the steel strip 1 is washed as number of rotation of brushes 5a, 5b and/or the rolling down force of the brush are increased.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of operating a brush type plate surface cleaning device for steel strips installed at the entrance of a cold rolling mill.

0002

[Prior Art] In general, surface defects of steel strips that occur during cold rolling include roll marks (caused by hard foreign objects such as metal pieces) caused by foreign objects attached to the surface of the steel strip being rolled together with the steel strip, and biting. Examples include scratches (caused by soft foreign substances such as rubber powder). As a countermeasure for this, a line is installed on the entrance side of the cold rolling mill with a plate surface cleaning device that sprays fluid onto the surface of the steel strip and polishes it with rotating brushes to remove foreign matter adhering to the surface of the steel strip. It has increased.

FIG. 1 shows an example of a line in which a brush type plate surface cleaning device is installed on the entrance side of a tandem cold rolling mill 2 for steel strip 1. In FIG. 1, the plate surface cleaning device 3 rotates a pair of upper and lower brush rolls 5a, 5b with brush drive motors 6a, 6b while spraying cleaning liquid from a cleaning liquid spray header 4, and rotates a pair of upper and lower brush rolls 5a, 5b with brush drive motors 6a, 6b. By pressing against the front and back surfaces of the steel strip 1, the front and back surfaces of the steel strip 1 are polished, and foreign matter adhering to the plate surface is removed.

[0004] The polishing conditions of the brush rotation speed and brush rolling force are set for each coil depending on the plate thickness, plate width, etc. of the rolled material. When the welding point where the steel strip of the leading coil and the steel strip of the trailing coil are welded passes the brush rolls 5a and 5b, a command is sent from the process computer 8 to the brush control device 9 to change the polishing conditions. It will be done. Note that 10 in the figure is a bridle roll on the entrance side of the rolling mill.

FIG. 3 is a diagram specifically showing a modification of conventional polishing conditions. In this example, after the welding point passes the brush rolls 5a, 5b, the brush rolls 5a, 5b
The rolling force is reduced in accordance with the reduction in the width of the rolled material.

[0006]

[Problems to be Solved by the Invention] The above-mentioned hard foreign matter adheres firmly to the surface of the steel strip in a certain range before and after the welding point, and in order to remove these hard foreign matter with a plate surface cleaning device, it is necessary to
It is necessary to take measures such as increasing the number of rotations of the brush or increasing the pressing force of the brush. On the other hand, in the longitudinal center of the coil, there are almost no hard foreign objects, and foreign objects with weak adhesion such as abrasion powder from resin rolls are mainly present, so the brush rotation necessary to remove the hard foreign objects is difficult. A sufficient cleaning effect can be obtained even if the number and brush pressure are not sufficient. Also,
From the point of view of the life of the brush, there is a problem that the life of the brush will be significantly shortened if the entire length of the coil is polished at the brush rotation speed and brush pressure required to remove hard foreign matter before and after the welding point.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, extend the life of the brush, and provide a method for operating a brush-type plate surface cleaning device that can effectively remove hard foreign matter adhering to a steel strip. shall be.

[0008]

[Means for Solving the Problems] The present invention provides a method for operating a brush type plate surface cleaning device for steel strips installed at the entrance side of a cold rolling mill, in which a leading steel strip and a trailing steel strip are connected by welding. This is a method of operating a brush-type plate surface cleaning apparatus for steel strips, which is characterized in that cleaning a predetermined range before and after a welding point is performed by increasing the number of rotations of the brush and/or the brush pressing force.

[0009]

[Function] As a result of investigation and study, the present inventors found that foreign matter adhering to the hard plate surface, such as metal pieces, which causes roll marks, is mainly due to inner diameter scratches during coil winding at the pickling line exit side, We have discovered that these are welding spatter residue, gouge flaws when the coil is taken out at the pickling line entrance side and the cold rolling machine entrance side, and these are concentrated in the vicinity of the welding point, and have arrived at the present invention.

According to the present invention, by increasing the number of rotations of the brush of the plate surface cleaning device and/or the pressing force of the brush only in a predetermined range before and after the welding point of the steel strip, adhesion to the plate surface near the welding point is removed. This method effectively prevents the occurrence of roll marks on the surface of the steel strip by removing hard foreign matter, and also reduces the brush lifespan by reducing the number of rotations of the brush and/or the rolling force of the brush except in a predetermined range before and after the welding point. can be extended.

[0011]

Embodiment FIG. 2 shows an embodiment of a method of operating a board cleaning apparatus according to the present invention. In this example, the rotational speed of the brush rolls 5a, 5b and the rolling force of the brush rolls 5a, 5b are increased from xm before the welding point passes the brush roll,
Remove hard foreign matter attached before and after the welding point.

[0012]The welding points are the brush rolls 5a and 5b.
After passing ym, the brush rolls 5a and 5b
The number of rotations of the brush rolls 5a and 5b are reduced to minimize wear of the brushes. The range xm, ym in which the polishing conditions are changed before and after the welding point may be determined by considering the margin for the length of the part to which the hard foreign matter is attached.

[0013] In this example, the brush rolls 5a and 5b
Although the number of rotations and the rolling force of the brush rolls 5a and 5b are increased, the present invention is not limited to this, and either the number of revolutions or the rolling force of the brush rolls 5a, 5b may be increased. In addition, the timing for changing the polishing conditions such as the number of rotations of the brush rolls 5a and 5b and the rolling force is determined by the process computer 8 that tracks the welding points in the line, and the polishing conditions are also determined by the process computer 8 to determine the thickness of the rolled material. , board width, etc. to be determined.

[0014]

[Effects of the Invention] As explained above, the present invention makes it possible to remove hard foreign matter adhering to the welding point of the steel strip on the entry side of a cold rolling mill, reducing the frequency of roll marks by 70%.
It has decreased by more than 20%. In addition, in other areas, the brush life is extended three times compared to the previous model, as the brush is operated at the minimum number of rotations and brush pressure required to remove foreign matter adhering to the board surface. .

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a line in which a brush type plate surface cleaning device is installed on the entrance side of a cold rolling mill.

FIG. 2 is a diagram showing an embodiment of the present invention.

FIG. 3 is a diagram illustrating an operating method of a conventional brush-type plate surface cleaning device.

[Explanation of symbols]

1 Steel strip 2 Tandem cold rolling mill 3
Brush type board cleaning device 4
Cleaning liquid spray header 5a, 5b Upper and lower brush rolls

Claims (1)

[Claims] Claim 1: A method of operating a brush-type plate surface cleaning device for steel strips installed at the entry side of a cold rolling mill, wherein A method for operating a brush-type plate surface cleaning device for steel strips, characterized in that cleaning is performed by increasing the number of rotations of the brush and/or the brush pressing force.