The present invention relates to improvement in a rolling mill for wise rolling metal rods particularly steel rods, to produce steel wires.
According to the presen, invention it is possible to produce wires
of various diameters staring from a rod of one diameter without
change rollers.
[Prior Art]
Production of wires of diameters in the range of several, millimeters to ten and several millimeters by wire rolling of steel rods has been usually carried out by using a material round rod having a diameter of 20 mm or so supplied from rough rolling step, rolling the material in a block mill equipped with eight rollers as intermediate rolling mill, and then, finish rolling the wire with a sizing mill equipped with two rollers. Structure of the rolling mill is as shown in Fig. 1.
There is strict requirement to sizes of steel wires depending on use thereof. For example, in the range of diameter
of 5-10 mm, products having the sizes of each 0.5mm increase are required, and in the range of diameter 10-20mm, those having the sizes of each 1.0mm increase are required. . Recently, it is demanded to supply wire products by hot rolling having various sizes which fully fit the needs.
A conventional method for satisfying this demand is the sequence of the following rolling steps, a typical example of which is illustrated in Pig. 2.
In the range of "very fine" (diameters 5.5, 6.0 and 6.5mm) wire rolling starts from a round rod of diameter 16.4mm supplied from rough intermediate line (Fig. 2). The rod material is first rolled by a block mill (F1-F8) having the first roller group to diameter 6.5mm, then the rolled material is passed to the si2ing mill to be rolled by both the front group of the rollers and the rear group of the rollers (5.5mm), or by only the front group of the rollers (6.0mm).
* In the range of "fine" (diameters 7.0, 7.5 and 8.0mm) a
round rod of diameter 20.5mm is used as the material from the
rough intermediate line. m order to switch to this range, it is
necessary to shut down the line to carry out roller change of all
the stands, and form a block mill (F1-F8) having the second roller
group. After rolling the round rod material of diameter 20.5mm
to 8.4mm, the rolled material is passed to the sizing mill so that
it may be rolled by both the front group and the rear group
(7.0mm), by only the front group (7.5mm), or by only the front
group of changed rollers.
* In the range of "intermediate fine" (diameters 8.5, 9.0,
9.5 and 10.0mm), rolling also starts from the same round rod
material of diameter 20.5mm as above (Fig. 3). The round rod
material is rolled by a part (F1-F6) of the blocX mill having the
second group of rollers to diameter 10.5mm. For this purpose it
is also necessary, after shutting down the line, to remove the
rollers of F7 and F8 stands, and to install a dummy guide. The
rolled material coming out of the dummy guide is passed to the
sizing mill so as to use both the front and the rear groups of
rollers (8.5mm), only the front group (9.5mm), or only the rear
group (10.0mm).
in the range of "intermediate bold" (diameters 11.0 and
12.0mm), the rolling also starts from the round rod material of diameter 20.5mm (also Fig. 3). Th© material is rolled by a part (F1-F4) of the block mill having the second group of rollers to diameter 13.5mm. Also in this case the rollers of F5 and F6 stands are removed and replaced with a dummy guide. The rolled material of diameter 13.5mm is passed to th© sizing mill , and rolled by both the front group and the rear group of the rollers (11.0mm), or by only the front group (12.0mm). Production of wires in the thickness range of "bold"
(diameters 13.0, 14.0, 15.0 and 16.0mm) starts also from the round rod of diameter 20.5mm, which is first rolled by a part (F1-F2) of the second group of rollers to diameter 16.4mm. Block mill rollers of F3 and F4 stands are also removed. The rolled material of diameter 16.4mm is passed to the sizing mill and rolled by both the front and the rear group of the rollers
(13-0mra), or by only the rear group (15.0mm). Alternatively, the rolled material is rolled, after changing rollers, by both the front and rear groups (14.0mm) or by only the rear group (16.0mm).
Wires in the thickness range of "very bold" (diameters 17.0, 18.0 and 19.0mm) are produced, also starting from the round rod material of diameter 20.5mm, by not using the block mill but directly using the si2ing mill. Both the front and the rear groups of the rollers are used (17.0mm), only the front group is used (19-0mm) or both the front and the rear groups with changed rollers are used (18.0mm). In Fig. 2 to Fig. 4 demarcation with lines indicates that rollers are used in the areas and that no roller is used in the other area. The round forms illustrate that calivers of the rollers (consequently, the sections of tho rolled material coming therefrom) are round, and the spindle form, obal sections of the rolled materials. The numerical figures annexed to the round forms show the diameters of the material coming out of the round caliver rollers. Change of sizing mill rollers is easy, and even the whole rollers can be changed. However, because ratios of rotating speeds of tne rollers are the same in the bloek mills, it is necessary to use continued stands. Also, because the roller axes are set fixedly to the passing line, it is necessary to carry out roller changing after interrupting the rolling operation in which the block mill is involved. in regard to the above described examples, in the thickness ranges of "very fine" and "fine" whole
the rollers of the block mill are changed. Changes between the thickness range of "fine" and "intermediate fine", "intermediate fine" and "medium bold", and "medium bold" and "bold" necessitate mounting and demounting of the rear group rollers.
Thua, attempt to produce steel wires of various sizes by the conventional technology requires troublesome preliminary work for roller change, and this lowers efficiency of production. if, however, largo scale production of one size at once is done for the purpose of avoiding the above problems, then, too much stock of the wire product must be kept. Additional problems such as scratching at handling and transporting and rusting during storage may occur.
[Problems to be solved by the invention]
The object of the present invention is to solve the above discussed problems relating to wire rolling, and to provide a method of rolling which enables production of wire products having various diameters from a round rod of one diameter without change of block mill rollers, which needs long time and much labor. The invention also provides a rolling mill for carrying out the rolling method. [Means for solving the Problems]
The method of rolling according to the present invention which achieves the above object is a method of wire rolling of metal rods supplied from rough rolling step by intermediate rolling with a block mill and finish rolling with a 3izing mill to form wire products. The method uses a rolling mill, which
comprises, as illustrated in Fig. 5, a block mill (BM), a sizing mill (SM) and a mini block mill (MBM) installed between the BM and the SM as a reducer. Rollers of the block mill (BM) are divided into two groups, the front group and the rear group, so as to make it possible either to use both the front and the rear groups, to use only the front group by dummy passing the rear group, or to use no block mill (BM) by by-passing the material to be rolled through another guide. The mini block mill (MBM) is shuntable from the pass line. The sizing mill (SM) consists of plural sets of rollers, and at least one of the sets is shuntable from the pass line. Combinations of use and non-use of the rollers can be chosen so that it may be possible to produce wires of different diameters from a material round rod of one diameter.
The rolling mill for carrying out the above described method of rolling is the rolling mill for wire rolling of metal rods supplied from rough rolling step by intermediate rolling with a block mill and finish rolling with a. sizing mill to form wire products. The rolling mill comprises, as illustrated in Pig. 5, a block mill (BM), a sizing mill (SM) and a mini block mill (MBM) installed between the block mill and the sizing mill as a reducer. Rollers of the block mill (BM) are divided into two groups, the front group and the rear group, so as to make it possible either to use both the front and the rear groups or only the front group by passing the rear group with a dummy pass (DPI); and a guide or guides for by-passing (BP) the material to be rolled. The mill also has another dummy pass (DP2), and thus, the mini block mill is shuntable from the pass line. The sizing mill consists of plural sets of rollers, and at least one of the sets is shuntable
from the pass line. Combinations, of use and noia-use of the rollers can be chosen so as to make it possible to produce wires of different diameters from a material round rod of one diameter.
Accordingly the present invention relates to an appartment for rolling wire rods having selected final diameters from a rod of single diameter supplied from a roughing mill along a pass line wherein the mill includes an intermediate block mill BM for receiving rod from the roughing mill, the block mill BM having rollers arranged in a front group BM1 "and a rear group BM2 characterised in that each of said front and rear groups can be dummied, the mill further including a mini block mill MBM for receiving rod from the block mill BM which is shuntable from the pass line and a sizing mill SM for receiving rod from the mini block mill MBM, the sizing mill having plural sets of rollers SMI,2 at least one of which sets is shuntable from the pass line, said method comprising selecting combinations of the block mill roller groups BM 1,2, mini block mill MBM and sizing roller sets SM 1,2 and rolling rod through the selected combination so as to produce a wire rod havirg a desired final calibre.
[Brief Explanation of the Accompanying Drawings]
[Fig. 1] A schematic diagram showing .roller distribution in a conventional wire rolling mill.
[Pig. 2] Explanation for rollers usod, sections and diameters of the material in the process of rolling when wires of various sizes are produced by using the wire rolling mill-shown in Fig. 1.
[Tig. 3] Explanation like Fig. 2 for the steps subsequent to Pig. 2.
[Fig. 4] Explanation like Fig. 2 for the steps subsequent to Fig. 3.
[Fig. 5] Schematic diagram corresponding to Fig. 1 showing roller distribution in wire rolling mill according to the present invention.
[Fig. 6] Explanation like Fig. 2 for rollers used, sections and diameters oi the material in the process of rolling when wires of various sizes are produced by using the wire rolling mill shown in Fig. 5.
[Fig. 7] Explanation like Fig. 5 for the steps subsequent to Fig. 5.
[Fig. 8] Explanation like Fig. 5 for the steps subsequent to Fig. 7.
[Embodiments of the Invention]
The by-passes for the rollers can be provided by installing guides to pass the rolled wires or the material wiros to be rolled in suitable positions in close vicinity to the center of the rolling line without interference to the rollers or to changing the rollers.
Combinations of paths through which the material rods and the rolled wires run are tabulated below. In the table, "Case A" contains the cases with use of the block mill, and "Case B", Without use. The abbreviations in the table have the following meanings:
BM block mill
BM1 front group of rollers of the block mill BM2 rear group of rollers of the block mill MBM mini block mill SM1, 2 sizing mill3 BP by-pass DP1-3 dummy pass a-t roller pair of the sizing mill
Case A
Case B (Table Removed)
[0018]
[Examples]
Round rods of a carbon steel having diameter 20.5mm were used as the starting material, and rolling was carried out in accordance with the sequences shown in Fig. 6, Fig. 7 and Fig. 8 to obtain wire products having diameters as shown in the Figures, in these Figures the parts demarcated with lines, round circles and spindle shapes, and the numerical figures added thereto have the meanings as explained in regard to Fig. 2 to Fig. 4. [Merits of the Invention]
By wire rolling in accordance with the present invention, which uses reducers and by-passes, it is possible to produce wires having various diameters from one starting material without changing rollers of the block mill. Because changing rollers of the block mill requires, as noted before, considerable time and labor, elimination of the necessity of changing rollers results in not only increased production efficiency but also decreased number of rollers to be used. The fact that the product sizes can be easily changed covers drawback of the conventional technology that it is forced to produce, once the rollers are changed, a considerable quantity of products at once, and realizes "many grades-small quantity" production without undesirable increase of costs. This merit contributes also to lighten the problems of scratching at handling and rusting during storage mentioned before.

WE CLAIM:
1. A method of rolling wire rods having selected final diameters from a rod of single diameter supplied from a roughing mill along a pass line wherein the mill includes an intermediate block mill BM for receiving rod from the roughing mill, the block mill BM having rollers arranged in a front group BM1 and a rear group BM2 characterised in that each of said front and rear groups can be dummied, the mill further including a mini block mill MBM for receiving rod from the block mill BM which is shuntable from the pass line and a sizing mill SM for receiving rod from the mini block mill MBM, the sizing mill having plural sets of rollers SM1,2 at least one of which sets is shuntable from the pass line, said method comprising selecting combinations of the block mill roller groups BM 1,2, mini block mill MBM and sizing roller sets SM 1,2 and rolling rod through the selected combination so as to produce a wire rod havirg a desired final calibre.
2. A rolling mill for rolling wire rod as claimed in claim 1 wherein selected final diameters from a single diameter supplied from a roughing mill along a pass line, said rolling mill comprising an intermediate block mill BM for receiving rod from a roughing mill, the block mill BM having a front group BM1 of fibers and a rear group BM2 wherein each of said front and rear groups can be independently dummied, the mill further including a mini block mill MBM for receiving rod from the block mill BM which can be shunted between an operative position on the pass line and a non-operative position away from the pass line and a sizing mill SM
comprising at least two sets SM1, 2 of rollers, at least one of which sets is capable of being shunted between an operative position on the pass line and a non-operative position away from the pass line, the rollers of the block mill BM, mini block mill MBM and sizing mill SM1, 2 being selectable in various combinations to produce wire rod of desired calibre from a single diameter wire rod supplied by the roughing mill.
3. A method of rolling wire rods substantially as hereinbefore described with reference to the accompanying drawings.
4. A rolling mill for wire rolling of metal rods substantially as hereinbefore described with reference to the accompanying drawings.