JPH0899120A - Coiling method for band steel - Google Patents

Abstract

PURPOSE: To reduce a top mark by an easy operation and remarkably improve the yield of a band steel by making the tip of the band steel, which becomes the beginning of the coiling of a coil into a saw-tooth shape. CONSTITUTION: The tip of a band steel 1, which becomes the beginning of coiling on a mandrel 4, is made in a saw-tooth shape 12. When coiling the band steel 1, a second wind is first placed upon the only tip of the saw-tooth shape 12. In this part, a sheet bend caused by a difference in level occurs but it is very small, and in the other parts, since placing one upon another does not occur, coiling is performed without causing the sheet bend. Therefore, a top mark is remarkably reduced. After coiling the band steel once, the occurrence states of the top mark and other sheet bends have been investigated by uncoiling a coil. As a result of the investigation, a flaw is observed in the position of πD of a first wind but the outside of it is not much influenced when the diameter of the mandrel 4 including a rubber sleeve 5 is expressed as D.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of winding a cold rolled steel strip by winding it around a mandrel of a tension reel.

[0002]

2. Description of the Related Art A cold rolled steel strip rolled by a cold rolling mill such as a cold strip mill is wound around a mandrel of a tension reel and wound into a coil. An example of the layout near the tension reel is shown in FIG. Reference numeral 1 is a steel strip, 3 is a deflector roll, 4 is a tension reel mandrel, and 5 is a rubber sleeve fitted to the mandrel.

Although the degree varies depending on the plate thickness of the steel strip 1,
As shown in FIG. 6, plate bending due to a step called a top mark occurs on the second and subsequent steel strips 1 overlapping the tip 11 of the steel strip 1 wound around the mandrel 4. Therefore, it is generally practiced to fit the rubber sleeve 5 on the mandrel 4 of the tension reel and wind the steel strip 1 on the mandrel 4, but the difference in plate thickness at the tip 11 of the steel strip 1 cannot be eliminated. , The top mark is somewhat relaxed but not a complete solution.

According to Japanese Unexamined Patent Publication No. 2-263515, a step 51 corresponding to the plate thickness of the steel strip 1 is provided on the outer peripheral surface of the rubber sleeve 5 as shown in FIG. 5 is synchronized with the peripheral speed of 5, and the tip 11 of the steel strip 1 is replaced by the rubber sleeve 5.
It has been proposed to wind the step portion 51 in contact with the step portion 51. However, this method requires an extremely advanced operation technique for aligning the tip portion 11 of the steel strip 1 with the stepped portion 51 of the rubber sleeve 5, and normally the feeding of the steel strip 1 is temporarily stopped. Since positioning is performed by inching operation, it took a long time to start winding, and the work efficiency was reduced.

Further, the present applicant has previously provided a strip-shaped soft layer 52 having a rubber hardness lower than that of the rubber sleeve main body in the outer peripheral body length direction of the rubber sleeve 5, as shown in FIG.
There is proposed a winding method in which the tip portion 11 of the above is stopped and wound in the strip-shaped soft layer 52 (see Japanese Patent Laid-Open No. 5-285540). This method is easier to align than the rubber sleeve 5 provided with the step portion 51, but due to the difference in the physical property values between the strip-shaped soft layer and the normal portion, a discontinuous surface is generated at the boundary portion and a small plate is formed. There is a problem that breakage occurs.

Further, it is also possible to use an ordinary cylindrical rubber sleeve and insert a soft strip 53 such as corrugated cardboard into the tip portion 11 of the steel strip 1 as shown in FIG. It is being appreciated. This method is simple and has some effects, but it is not preferable because it takes time to insert the soft strip 53 and is a dangerous work.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems in the conventional method and to provide a steel strip winding method capable of reducing the top mark by an easy operation. To do.

[0008]

SUMMARY OF THE INVENTION The present invention is a method of winding a steel strip which winds a steel strip around a mandrel and winds it around a coil, characterized in that the tip of the steel strip at the beginning of winding the coil has a sawtooth shape. It is a method of winding a steel strip.

[0009]

[Operation] According to the present invention, by making the tip of the steel strip at the beginning of coil winding into a sawtooth shape, the second winding overlapping the tip of the steel strip wound around the mandrel is minimal,
The plate break due to this step is also local, and the plate break does not occur over the entire width, so that the top mark is reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the tip of the steel strip, which is the beginning of winding on the mandrel 4, is formed into a sawtooth shape 12. When the steel strip 1 is wound up as shown in Fig. 2, the second roll first overlaps with a sawtooth shape.
It is only the tip of 12, and plate breaks due to steps occur at this part, but this is extremely small, and since the other parts do not overlap, winding is done without plate breaks. The top mark is greatly reduced. In addition, 6 is a shear.

Incidentally, by using a rubber sleeve having an inner diameter of 430 mm and an outer diameter of 508 mm, a saw-tooth shape 12 at the tip of an extremely low carbon steel cold-rolled steel strip having a sheet thickness of 0.8 mm and a sheet width of 1200 mm is shown in FIG. 3 (a). It wound up in. Saw tooth height H is 50 mm, saw tooth slant width L
₁ for 15 mm, saw tooth tip width L ₂ for 15 mm, saw tooth bottom width L ₃ for 15
I chose mm. Winding tension is 1.5kg / mm ² , rubber sleeve 5
Has a rubber hardness of 60 degrees (H _S 60 °), and a serrated shape 12 is formed on the tip of the steel plate by a guillotine shear 6. Here, the shear structure is such that the blade burr at the time of shear cutting occurs on the inner winding side.

FIG. 3B shows the result of investigating the occurrence of the top mark and other plate breaks after the coil is once wound and then the coil is rewound. According to this, it was found that the position of πD of the first winding was flawed, but the outside thereof was not affected so much. Incidentally. D is the diameter of the mandrel including the rubber sleeve. FIG. 4 shows the position where the top mark farthest from the tip is found by the distance from the tip of the steel strip. In the case of a normal rubber sleeve without a countermeasure against the top mark (comparative example) and the above embodiment, The results are shown.

The present invention has a remarkable effect of reducing the top mark, and has a good result that the position where the top mark is generated is reduced to about 1/5 as compared with the case where the tip of the steel strip is straight cut using a normal rubber sleeve. Has been obtained.

[0014]

According to the present invention, the top mark is reduced by a simple operation and the yield of steel strips is greatly improved.
It has an excellent effect.

[Brief description of drawings]

FIG. 1 is a plan view showing a sawtooth shape at the tip of a steel strip according to the present invention.

FIG. 2 is a cross-sectional view showing a winding state in the present invention.

FIG. 3 shows an embodiment of the present invention, (a) is a partial plan view showing the saw-tooth shape of the front end of the steel strip, and (b) is a portion showing the transfer state of the top mark at the time of rewinding the steel strip. It is a top view.

FIG. 4 is a graph showing the generation positions of top marks in Examples and Comparative Examples.

FIG. 5 is an explanatory diagram showing a layout near a tension reel according to a conventional technique.

FIG. 6 is a cross-sectional view illustrating a problem of the conventional technique.

FIG. 7 is a cross-sectional view showing a winding state in the conventional technique.

FIG. 8 is a cross-sectional view showing a winding state in the conventional technique.

FIG. 9 is a cross-sectional view showing a winding state in the conventional technique.

[Explanation of symbols]

1 Steel strip 3 Deflector roll 4 Mandrel 5 Rubber sleeve 6 Shear 11 Tip 12 Saw-tooth shape of tip 51 Step 52 Soft band 53 Soft band D Diameter of mandrel including rubber sleeve H Saw tooth height L ₁ Saw tooth inclination Width L ₂ Sawtooth tip width L ₃ Sawtooth bottom width

Claims (1)

[Claims] 1. A method for winding a steel strip, which comprises winding a steel strip around a mandrel and winding the coil around a coil, wherein the tip of the steel strip at the beginning of winding the coil has a sawtooth shape. .