JPS63281702A - Method for split rolling - Google Patents

Abstract

PURPOSE:To hold sure separation and to obtain plural equal final shape rolled stocks by forming a thin part and preparatory formed parts connecting with the thin part and dividing the preparatory parts into two parts by passing the preparatory parts between stepped rollers facing to each other. CONSTITUTION:One square stock 1, etc. is flattened by preparatory rolling, a thin part 2 along the rolling direction is formed, and then a couple of flat parts F connected with the thin part S are formed by the succeeding rolling. Next, the stock is passed through a split roller stand having a couple of separator rollers SR consisting of a large diameter part D1 and a small diameter part D2. A separating force, caused by a peripheral speed difference between that of the part D1 and that of the part D2 of the roller SR, which separates the plural preparatorily formed parts up and down is applied to the parts so that the parts are separated at the thin part S. Separated square stocks 1 are rolled to be an oval shape and then are rolled to be a round shape.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a split rolling method.

(Prior art and its problems) Conventionally, as a split rolling method, as shown in Fig. 7, after rolling a square cross-sectional material into a peanut shape, two round cross-sectional materials are rolled into a thin section with a thickness of 0.5 to 1 mm. It is rolled into a multi-strip preformed part in the shape of a pair of eyeglasses, and passed between two solo pan bead-shaped rollers (tip angle of about 90 degrees) as shown in Fig. 8 to divide the preformed part in the left and right directions. A method has been proposed, but the cut edges of the preformed part divided in the left and right directions are sharp and the undulations are severe, and the round dimensions are not accurate due to the effect of splitting, so the method shown in the latter part of Fig. 7 is difficult. There is a drawback that the final round size of the steel bar is not constant due to the influence of the shape at the time of splitting during nine-over-round rolling after processing, that is, splitting. Therefore, as shown in Figures 9 and 10, four rollers (A, B, C, D) are lined up facing each other, and rollers (A and B) are arranged with steps in the vertical direction.
A method has been proposed in which the spectacle-shaped rolled material is passed between C and D) and divided into upper and lower parts, but this method requires driving each of the four rollers from the direction shown by the arrow, and the mechanical structure is extremely complicated. There is a problem with becoming. Therefore, in order to implement the method of dividing the upper and lower parts with a simple structure, as shown in FIG. A method has been proposed in which a plurality of rolled materials are manufactured by dividing each preparatory forming section into upper and lower parts at the thin-walled part due to the circumferential speed difference between the upper and lower surfaces. Since it is a circle, it rotates in the direction of the arrow, making it impossible or extremely difficult to separate.

(Objective of the Invention) The present invention aims to provide a split rolling method that uses the difference in circumferential speed between upper and lower divided rollers with a simple mechanical structure, which ensures reliability in parting and provides a constant final shape. purpose.

(Structure of the Invention) The present invention was completed by changing the conventional eyeglass-shaped pass schedule and preventing rotation of the rolled material during separation. In rolling manufacturing, the above-mentioned single material is rolled to form a thin-walled part along the rolling direction, thereby forming a plurality of connected preformed parts and a flat part on the upper and lower surfaces of the plurality of preformed parts. After the flat part is formed, the flat part is passed between a pair of separator rollers, each of which has a large diameter part DI and a small diameter part D2, and which are arranged opposite each other. The split rolling method is characterized in that a plurality of rolled materials are manufactured by dividing the material into upper and lower parts at a thin wall portion. The present invention is applicable not only to split rolling for manufacturing multiple steel bars from one material, but also for split rolling for materials that have flat parts on the upper and lower surfaces, and is applicable to rolling multiple flat bars from one material. It is also applicable to manufacturing.

When manufacturing a round bar according to the present invention, a billet material with a square cross section is used as the single material, so after forming a recessed thin part along the rolling direction by preparatory rolling,
It is preferable to form a flat portion (see Figure 1).

In addition, in order to securely hold the rolled material, the large diameter portion D
A pair of guide rollers having the same diameter are disposed in front of a pair of separator rollers consisting of I and a small diameter portion D2, and flat portions on the upper and lower surfaces of a plurality of strips of preformed portions connected at the thin wall portion between the guide rollers. It is preferable to divide the plurality of preformed parts into upper and lower parts at thin-walled parts by the difference in circumferential speed between the step rollers of a pair of separator rollers while gripping the rollers (see FIG. 3).

(Effects of the Invention) According to the present invention, a pair of separator rollers consisting of a large diameter portion DI and a small diameter portion D2 are passed between step rollers arranged opposite each other, and a plurality of preformed portions are separated by a thin portion. In this process, each preparatory forming part is separated at the thin-walled part by the difference in circumferential speed between the upper and lower surfaces while holding the flat part to produce a plurality of rolled products, which eliminates cutting errors caused by rotation of the rolled material during separation. Split rolling can be realized by vertical division with high dimensional stability using a simple machine configuration that does not cause problems and facilitates maintenance and misroll treatment.

Hereinafter, the present invention will be described in detail based on specific examples shown in the accompanying drawings.

(Example) Figure 1 shows split rolling of a steel bar according to the present invention □
FIG. 2 is a perspective view showing a split roller stand ST for performing split rolling according to the present invention, and FIG. 3 is a cross-sectional view along the I[l-I[[ line;
FIGS. 4 and 5 are explanatory diagrams showing the state of the rolled material passing between the guide roller and the separator roller.

In rolling and manufacturing multiple steel bars from one material, according to the pass schedule shown in Figure 1, a square bar l with a substantially square cross section is pressed diagonally to flatten it by preparatory rolling, and then rolled in the rolling direction. After forming the concave thin-walled portion 2 along the same, a pair of flat portions F connected by the thin-walled portion S are formed in the next stage of rolling.

Then, it is passed through a split roller stand ST shown in FIG. The stand includes a pair of guide rollers G having the same diameter arranged in front of a pair of separator rollers SR consisting of a large diameter portion D1 and a small diameter portion D2. Note that the guide roller is not a flat roller as shown in the drawings, but a roller having a guide tab in the center or a roller having guide tabs on both sides may be used. In addition, although the guide roller G and separator roller SR are basically driven only from one direction, the guide roller and separator roller are made smaller, and instead of being driven, the rolled material is moved by the force of the roll stand pushing the rolled material. It may also be configured to split the.

According to the above structure, since the plurality of preformed parts connected by the thin part have a hexagonal shape, the flat parts of the upper and lower surfaces are gripped between the guide rollers GG (see Fig. 4), and a stable posture is maintained. It is maintained. Between the step rollers of the pair of separator rollers S and S, a force is applied to vertically separate the preformed part of the plural strips due to the circumferential speed difference between the large diameter part Di and the small diameter part D2. However, at the time of such separation, the flat part F maintains a stable posture and prevents rotation, so that a smooth split occurs.
It will be divided into symmetrical shapes.

Next, as shown in the lower part of FIG. 1, the square material is rolled into an oval shape and then into a round shape.

When split rolling a flat bar instead of the round bar split rolling described above, rolling is performed as shown in FIG. 6 after splitting.

[Brief explanation of drawings]

FIG. 1 shows a pass schedule for split rolling of steel bars according to the present invention, FIG. 2 is a perspective view showing a split roller stand for carrying out the method of the present invention, and FIG.
4 and 5 are explanatory diagrams showing the state of the rolled material passing between the guide roller and the separator roller, and FIG. 6 shows the pass schedule for split rolling of the flat bar according to the present invention. . Fig. 7 shows a pass schedule for conventional split rolling of steel bars, Fig. 8 is a schematic diagram showing an example of split rolling in the left and right directions, and Fig. 9 and Fig. 1O show examples of conventional split rolling in the vertical direction. FIG. 11 is an explanatory diagram showing problems in split rolling according to the conventional pass schedule shown in FIG. 7 using the separator roller used in the present invention. F...Flat part, S...Thin wall part, G...Guide roller, sn...Separator roller. Patent applicant: Kobe Steel, Ltd. Representative: Patent attorney: Mr. Maeda and 2 others Figure 1
Figure 6 Figure 2G Figure 3 Figure '7

Claims (3)

[Claims] (1) When manufacturing multiple steel bars or flat bars from a single material by rolling, the single material is rolled to form a thin walled portion along the rolling direction, thereby preforming multiple connected strips. After forming flat portions on the upper and lower surfaces of the preformed portion, the flat portions are passed between step rollers formed by a pair of separator rollers each having a large diameter portion D1 and a small diameter portion D2 that are arranged facing each other. A split rolling method characterized in that a plurality of rolled materials are produced by separating each preparatory forming section at the thin wall section due to a circumferential speed difference between the upper and lower surfaces. (2) The split rolling method according to item 1, wherein the single material is a square cross-sectional material, and a thin portion is formed along the rolling direction by preparatory rolling, and then a flat portion is formed. (3) A pair of guide rollers having the same diameter is disposed in front of a pair of separator rollers consisting of the large diameter portion D1 and the small diameter portion D2, and preforming of multiple strips connected by the thin wall portion between the guide rollers. 2. The split rolling method according to item 1, wherein the preformed part of the plurality of strips is divided into upper and lower parts at the thin wall part by a peripheral speed difference between the step rollers of a pair of separator rollers while gripping the flat parts on the upper and lower surfaces of the part.