TECHNICAL FIELD
The present invention relates, in general, to cylinder rings which prevent end marks from being generated on rolled sheets and, more particularly, to a cylinder rings which have a plurality of elongated protrusions or embossments arranged around an outer surface of the cylinder ring to prevent the formation of an end mark that is a stepped mark generated on the rolled sheet in a latitudinal direction while the rolled sheet, produced by either a hot or cold rolling process, is wound around a mandrel.
BACKGROUND ART
FIG. 1 is a view showing a conventional cylinder ring 40 around which a rolled sheet 50 is wound. FIG. 2 is a partially enlarged view of the conventional cylinder ring 40 of FIG. 1 around which the rolled sheet 50 is wound. FIG. 3 is a plan view of the rolled sheet 50 with end marks M after being wound around the conventional cylinder ring 40 of FIG. 2.
As shown in FIGS. 1 through 3, generally, the rolled sheet 50 produced by a rolling mill 10 is transferred to a mandrel 30 of a down coiler. Thereafter, a sheet end 51 of the rolled sheet 50 is guided by a guider unit 20, thus the rolled sheet 50 is wound around an outer surface of the mandrel 30. At this time, to prevent the rolled sheet 50 wound around the mandrel 30 from being deformed by a collision, and to prevent a slip between the rolled sheet 50 and the outer surface of the mandrel 30 from being caused, the cylinder ring 40 is provided on the outer surface of the mandrel 30.
The rolled sheet 50 is tightly wound around the conventional cylinder ring 40 to prevent the rolled sheet 50 wound around the cylinder ring 40 from being undesirably unwound or loosened from the cylinder ring 40. Therefore, the rolled sheet 50 wound around the cylinder ring 40 is tightened to apply a compression force toward a central portion of the mandrel 30. As shown in FIG. 2, a space is defined around the sheet end 51 of the rolled sheet 50 at a position between the cylinder ring 40 and the rolled sheet 50. The rolled sheet 50 wound around the cylinder ring 40 applies a pressure on each of portions of the rolled sheet 50 which are aligned with the sheet end 51. Thus, a plastic deformation is generated on each of the portions of the rolled sheet 50 which are aligned with the sheet end 51, so that an end mark M is generated on each of the portions of the rolled sheet 50 which are aligned with the sheet end 51, as shown in FIG. 3. The rolled sheet 50 with the end marks M causes a deformation or stripping of a coated or painted layer thereof, thus reducing its production quality.
To solve the problems experienced in the conventional cylinder ring 40, a variety of techniques for preventing the end mark M of the rolled sheet 50, controlling a speed winding the rolled sheet, grinding the sheet end of the rolled sheet to be not stepped, or mounting a separate absorbing unit on the sheet end, were proposed in Japanese Patent Nos. 3042381-B2, 3152286-B2, Japanese Patent Laid-Open Publication Nos. Heisei 10-005860-A, Heisei 10-128439-A and 2000-5917-A. However, to prevent the end marks M from being generated on the rolled sheet, the conventional techniques according to the above-mentioned force users to mount a separate unit on the rolled sheet for each rolling process or to execute an additional process. Thus, the conventional techniques impose additional expenses on users.
Furthermore, a cylinder ring with protrusions and depressions to prevent the end marks M from being generated on the rolled sheet wound around the cylinder ring was proposed in Korean Patent Laid-Open Publication NO. 2003-0020468.
FIG. 4 is a perspective view showing another conventional cylinder ring 100 for preventing formation of an end mark of a rolled sheet 50. FIG. 5 is a plan view of the conventional cylinder ring 100 of FIG. 4 in which the rolled sheet 50 is wound around the cylinder ring 100. FIG. 6 is a partially enlarged sectional view showing states of the rolled sheet 50 and the conventional cylinder ring 100 of FIG. 5 being varied according to a position of a sheet end 51 of the rolled sheet 50 relative to the cylinder ring 100 when the rolled sheet 50 is wound around the cylinder ring 100.
As shown in FIGS. 4 and 5, the conventional cylinder ring 100 includes a plurality of elongated protrusions 110 and a plurality of elongated depressions 120 which are alternately arranged around an outer surface of the cylinder ring 100 defining a ring-shaped cross-section. In the conventional cylinder ring 100, the rolled sheet 50 may be wound around the cylinder ring 100 in one of the three states shown in (a), (b) and (c) of FIG. 6.
That is, as shown in (a) of FIG. 6, the sheet end 51 of the rolled sheet 50 may be in contact with a sidewall of a second elongated protrusion 110b which is one of the plurality of elongated protrusions 110. The rolled sheet 50 of the above-mentioned state allows the sheet end 51 thereof to be bent inward by a pressure applied from an upper portion of the rolled sheet 50 wound around the cylinder ring 100, with the second elongated protrusion 110b acting as a support. Due to the pressure generated from the upper portion of the rolled sheet 50 wound around the cylinder ring 100, a third elongated protrusion 110c, placed in back of the second elongated protrusion 110b, is more compressed radially toward a rotating axis of the cylinder ring 100 than the second elongated protrusion 110b. Thus, the sheet end 51 of the rolled sheet 50 in the above-mentioned state almost does not have a repulsive force against the pressure applied from the upper portion of the rolled sheet 50 wound around the cylinder ring 100. Therefore, the end marks M are rarely generated on the rolled sheet 50.
As shown in (b) of FIG. 6, the sheet end 51 of the rolled sheet 50 is placed above an elongated depression 120 between a first elongated protrusion 110a and the second elongated protrusion 110b after passing over the second elongated protrusion 110b. In the rolled sheet 50 of the state of (b) of FIG. 6, the sheet end 51 of the rolled sheet 50 is bent inward by the pressure applied from the upper portion of the rolled sheet 50 wound around the cylinder ring 100. Thus, the second elongated protrusion 110b is elastically compressed radially toward the rotating axis of the cylinder ring 100. At this time, the second elongated protrusion 110b is more compressed by a thickness of the rolled sheet 50 than the first elongated protrusion 110a which is placed in front of the second elongated protrusion 110b. Therefore, the sheet end 51 of the rolled sheet 50 in the above-mentioned state almost does not have a repulsive force against the pressure applied from the upper portion of the rolled sheet 50 wound around the cylinder ring 100, so that the end marks M are rarely generated on the rolled sheet 50 wound around the cylinder ring 100.
As shown in (c) of FIG. 6, the sheet end 51 of the rolled sheet 50 may be placed along a linear ridge of the second elongated protrusion 110b. An area of the linear ridge of each of the elongated protrusions 110 is very small in comparison with the remaining port of the outer surface of the cylinder ring 100. Thus, the possibility of occurrence of the state of (c) of FIG. 6 is very low compared to the possibility of the states of (a) and (b) of FIG. 6. However, in case that the sheet end 51 of the rolled sheet 50 is placed along the linear ridge of the second elongated protrusion 110b, even though the second elongated protrusion 110b is more or less elastically compressed, the sheet end 51 of the rolled sheet 50 may have a repulsive force in the same manner as that described for the cylinder ring 40 of FIG. 1. Therefore, the conventional cylinder ring 50 is problematic in that the end marks M may be generated on the rolled sheet 50.an ineffective treatment of the sludge.
DISCLOSURE OF THE INVENTION
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a cylinder ring which prevents an end mark from being generated on a rolled sheet wound around the cylinder ring even when a sheet end of the rolled sheet is placed on a peak of any protrusion, and which has a plurality of elongated protrusions and a plurality of elongated depressions which are alternately arranged around the outer surface of the cylinder ring to be inclined relative to a rotating axis of the cylinder ring at a predetermined angle, or has a plurality of embossments arranged around the outer surface of the cylinder ring to be spaced apart from each other at regular intervals, thus preventing the end mark from being generated on the rolled sheet wound around the cylinder ring.
In order to accomplish the above object, the present invention provides a cylinder ring which receives a mandrel therein and is made of an elastic material to wind a rolled sheet around an outer surface of the cylinder ring in a coiled pattern, the cylinder ring comprising: a plurality of elongated protrusions and a plurality of elongated depressions which are alternately arranged around the outer surface of the cylinder ring, wherein the elongated protrusions and the elongated depressions are inclined relative to a rotating axis of the cylinder ring at a predetermined angle to prevent end marks from being generated on the rolled sheet wound around the cylinder ring.
DESCRIPTION OF DRAWINGS
The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a view showing a conventional cylinder ring around which a rolled sheet is wound;
FIG. 2 is a partially enlarged view of the conventional cylinder ring of FIG. 1 around which the rolled sheet is wound;
FIG. 3 is a plan view of the rolled sheet with end marks after being wound around the conventional cylinder ring of FIG. 2;
FIG. 4 is a perspective view showing another conventional cylinder ring for preventing formation of an end mark of a rolled sheet;
FIG. 5 is a plan view of the conventional cylinder ring of FIG. 4 around which the rolled sheet is wound;
FIG. 6 is a partially enlarged sectional view showing states of the rolled sheet and the conventional cylinder ring of FIG. 5 being varied according a position of a sheet end of the rolled sheet relative to the cylinder ring when the rolled sheet is wound around the cylinder ring;
FIG. 7 is a perspective view of a cylinder ring for preventing formation of an end mark of a rolled sheet, according to a first embodiment of the present invention;
FIGS. 8 and 9 are respectively a sectional view and a plan view of the cylinder ring of FIG. 7 around which the rolled sheet is wound;
FIGS. 10, 11 and 12 are perspective views of cylinder rings, according to second, third and fourth embodiments of the present invention, respectively; and
FIG. 13 is a sectional view showing a variety of shapes of an embossment of the cylinder ring of FIG. 11.
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Reference should now be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.
FIG. 7 is a perspective view of a cylinder ring 200 for preventing formation of an end mark of a rolled sheet 50, according to a first embodiment of the present invention. FIGS. 8 and 9 are respectively a sectional view and a plan view of the cylinder ring 200 of FIG. 7 around which the rolled sheet 50 is wound.
As shown in FIGS. 7 through 9, the cylinder ring 200 according to the first embodiment of the present invention is made of an elastic material and defines a space to receive a mandrel therein. The cylinder ring 200 includes a plurality of elongated protrusions 210 and a plurality of elongated depressions 220 which are alternately arranged around the outer surface of the cylinder ring 200. Particularly, the plurality of elongated protrusions 210 and the plurality of elongated depressions 220 are arranged around the outer surface of the cylinder ring 200 to be inclined relative to a rotating axis of the cylinder ring 200 at a predetermined angle θ.
The rolled sheet 50, which passed through a rolling mill, is wound around linear ridges of the plurality of elongated protrusions 210 of the cylinder ring 200 having the mandrel therein. At this time, a sheet end 51 of the rolled sheet 50 is in contact with the elongated protrusions 210 at portions A and B of FIG. 9 while being not in parallel with any elongated protrusion 210.
Therefore, the rolled sheet 50, wound around the cylinder ring 200, applies a repulsive force causing the end mark to only the portions A and B of FIG. 9 in which the sheet end 51 is in contact with the linear ridges of the elongated protrusions 210. However, the portions A and B of FIG. 9 are very small-sized parts in comparison with a length of the sheet end 51 of the rolled sheet 50. Thus, the end mark generated by a concentrated stress is not generated on the rolled sheet 50 wound around the cylinder ring 200.
As shown in FIG. 9, in the cylinder ring 200 according to the first embodiment of the present invention, the angle θ of inclination of the plurality of elongated protrusions 210 and elongated depressions 220 relative to the rotating axis of the cylinder ring 200 is set to a range of 20° to 70°. The range of the inclination angle θ resulted when the inventor of the present invention executed several experiments that wound the rolled sheet 50 around the cylinder ring 200.
In case of the inclination angle θ less than 20°, the contact areas of the portions of the sheet end 51 of the rolled sheet 50, which are in contact with the linear ridges of the elongated protrusions 210, are increased. Thus, the end mark may be generated on the rolled sheet 50 wound around the cylinder ring 200. In case that the inclination angle θ ranges from 70° to than 90°, each of the elongated protrusions 210, which is in contact with the rolled sheet 50, is provided around the outer surface of the cylinder ring 200 in a circumferential direction in place of the axial direction. Thus, it is very difficult to tightly wind the rolled sheet 50 around the cylinder ring 200.
FIGS. 10, 11 and 12 are perspective views of cylinder rings 300 and 400, according to second, third and fourth embodiments of the present invention, respectively. FIG. 13 is a sectional view showing a variety of shapes of an embossment of the cylinder ring 400 of FIG. 11.
As shown in FIG. 10, the cylinder ring 300 according to the second embodiment of the present invention includes a plurality of elongated protrusions 310 and a plurality of elongated depressions which are alternately arranged around the outer surface of the cylinder ring 300 to be inclined relative to a rotating axis of the cylinder ring 300 at a predetermined angle, in the same manner as that described for the construction of the cylinder ring 200 according to the first embodiment of FIG. 7. However, each of the elongated protrusions 310 of the cylinder ring 300 includes a plurality of notches which are provided along the elongated protrusion 310 while being spaced apart from each other at regular intervals, different from the elongated protrusion 210 of the cylinder ring 200 according to the first embodiment. Due to the above-mentioned construction of the cylinder ring 300, the contact areas of the elongated protrusions 310, which are in contact with the sheet end of the rolled sheet, become smaller than the contact areas of the elongated protrusions 210 of the cylinder ring 200 according to the first embodiment of FIG. 7. Therefore, the cylinder ring 300 more efficiently prevents the end mark from being generated on the rolled sheet wound around the cylinder ring 300.
As shown in FIGS. 11 through 13, the cylinder ring 400 according to each of the third and fourth embodiments of the present invention includes a plurality of embossments 410 which have hemispherical shapes and are arranged around the outer surface of the cylinder ring 400 to be axially and circumferentially spaced apart from each other at regular intervals. Each of the embossments 410 of the cylinder ring 400 has an internal pressure which allows the embossments 410 to be slightly deformed, so that the rolled sheet can be evenly wound around the cylinder ring 400 in the same manner as that described for the elongated protrusions 210 and 310 according to the first and second embodiments.
Particularly, in the cylinder ring 400 according to the fourth embodiment of the present invention, as shown in FIG. 12, the plurality of embossments 410 are arranged on the outer surface of the cylinder ring 400 along a plurality of lines inclined at a predetermined angle relative to a rotating axis of the cylinder ring 400. Therefore, when the rolled sheet is wound around the cylinder ring 400 according to the fourth embodiment, a contact area of the sheet end of the rolled sheet, which is in contact with the embossments 410, is reduced in comparison with the conventional cylinder ring. Thus, the cylinder ring 400 according to the fourth embodiment efficiently prevents the end mark from being generated on the rolled sheet wound around the cylinder ring 400.
At this time, to reduce the contact area between the rolled sheet and the embossments 410 of the cylinder ring 400, as shown in FIGS. 11 and 13, each of the embossments 410 has a shape of the hemispherical shape, a circular conical shape or an elliptic conical shape. Furthermore, in the cylinder ring 400 according to each of the third and fourth embodiments, each of the embossments 410 may have a cylindrical shape, a rectangular shape or another shape to stably support the rolled sheet being wound around the cylinder ring 400.
INDUSTRIAL APPLICABILITY
As described As described above, the present invention provides a cylinder ring which has a plurality of protrusions which are arranged around an outer surface of the cylinder ring to be inclined relative to a rotating axis of the cylinder ring at a predetermined angle. Thus, the cylinder ring according to the present invention reduces a contact area between a sheet end of a rolled sheet and the protrusions in comparison with a conventional cylinder ring, thus efficiently preventing an end mark from being generated on the rolled sheet wound around the cylinder ring.
Although the cylinder rings for preventing formation of the end mark of the rolled sheet according to the preferred embodiments of the present invention have been disclosed for illustrative purposes with reference to the accompanying drawings, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
Patent Application
20060169016
