JPS60255202A - Indentation cutting method - Google Patents

Abstract

PURPOSE:To prevent the generation of a fish tail and scab at the rolled end of a material to be cut by advancing a pair of V-shaped blades toward said material from both sides in the horizontal direction thereto to form notches to the material then advancing the blades to the material from both sides in the perpendicular direction thereby cutting the material. CONSTITUTION:Horizontal blades 12 are advanced along the line in the advancing direction of the blade edges so as to enter a billet 11 by about 20-30% of the width of the billet 11 toward the transverse center of the billet. The notches 11a are formed to the billet 11 when the blades 12 are retreated from the billet 11. Vertical blades 14 are advanced from this state along the line in the advancing direction of the blade edges, by which the indentation of the blade edges is started. The force in the longitudinal direction acts on the billet 11 as the penetration to the billet 11 progresses until the tensile stress in the uncut part attains the yield stress, when the material is plastically deformed. The blades 14 are stopped prior to collision of the blade edges when the space between the edges of both vertical blades 14 attains an extremely small space on progression of the penetration. Necking arises in the connecting metal part slightly remaining in the extremely small space and the billet 11 is cut.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a push-cutting method for cutting a material such as a continuously cast slab by pushing a V-shaped blade from both sides thereof.

[Prior art]

Conventionally, an effective method for cutting the material to be cut, such as a slab made by continuous casting, is to place a pair of V-shaped blades on both the upper and lower sides of the slab and move them in a direction perpendicular to the slab surface to cut into the slab. A push-cutting method is adopted in which the cutter is cut from the K when pushed in.

According to this cutting method, the slab is cut at the same time as the cutting edge is preformed into a tapered shape, and a cutting burr is generated in the center of the thickness of the slab. There is no possibility that cutting burrs will be generated on the surface of the cut end, unlike when the slab is cut by shearing force by passing the slabs in front of each other.

Therefore, when this cut slab is passed through a rolling mill and rolled, the tapered preforming greatly reduces the width expansion and overlap that occur at the front and rear ends of the rolled product. In addition, cutting burrs are generated in the center of the plate thickness, which reduces the number of flaws that occur at the front and rear ends of the rolled product, which has the excellent advantage of improving the yield of the product. Furthermore, according to the cutting method, since the tapered υ shape is preformed,
There is no need to provide a special preforming process between the cutting process and the rolling process compared to the conventional method, which not only improves work efficiency but also prevents the rollers from being poked during conveyance and biting during rolling. More stable transportation with no defects,
Rolling becomes possible.

As described above, the push-cutting method has many excellent advantages, but the conventional push-cutting method involves cutting by inserting a pair of V-shaped blades into the material to be cut from above and below in the thickness direction. Problems still remained in the following points. In other words, when cutting and rolling continuously cast slabs, the width and thickness of the continuous cast slabs are generally kept constant in order to increase the productivity of the continuous casting machine, and in order to obtain rolled products with a wide range of widths and thicknesses, rolling is required. This is addressed by changing the rate. In this case, the usual method is to roughly roll the cut slab in both the width and thickness directions using a vertical roller rolling mill and a horizontal roller rolling mill, and then finish rolling it in the thickness direction using a horizontal roller rolling mill. In a slab cut by a conventional vertically moving V-shaped blade, when the slab is rolled in the width direction with a vertical roller mill and then rolled in the thickness direction with a horizontal roller mill, as shown in Fig. 1, The unevenness caused by vertical roller rolling, the so-called fishtail 1a, is the slab 1.
Occurs at the rolling end. The part where this fishtail 1a has occurred will not become a product even if it is rolled, and various problems will occur during finishing rolling of a part with a fishtail 1a, so a crop cutter provided at the entrance side of the finishing mill is used. This area is removed by cutting with a shear as shown by the chain line in the figure, which has the disadvantage of significantly lowering the yield of the product. Further, in the case of cutting using a conventional vertically movable V-shaped blade, a satisfactory effect in terms of preventing the occurrence of scratches cannot necessarily be expected.

[Summary of the invention]

The present invention has been made in view of the above points, and after forming a notch by entering a pair of V-shaped blades into the material to be cut from both sides in the horizontal direction, the V-shaped blades are retreated, and the pair of V-shaped blades are By configuring the V-shaped blade to enter and cut the material to be cut from both sides in a vertical direction, the product yield is improved by preventing the occurrence of fishtails and flaws during rolling. A push-cutting method is provided.

Embodiments of the present invention will be described in detail below with reference to the drawings.

〔Example〕

FIG. 2 is a side view of a workpiece to be cut and a cutting blade for explaining the push cutting method according to the present invention, and FIG. 3 is a plan view thereof. This example shows an example in which the present invention was applied to cutting a continuously cast slab steel billet (hereinafter abbreviated as steel billet), and in the figure,
A steel piece 11 as a material to be cut has a flat rectangular cross section, and is held so as to be movable in the horizontal direction at two positions on the left and right away from the cutting location. On both sides of the steel piece 11 in the width direction, a pair of horizontal blades 12 having the same height as the thickness of the steel piece 11 are arranged with their cutting edges facing each other, and the cutting edges have an inclined surface 12a, It is formed in a V-shape consisting of 12b. A chain line 13 is a cutting edge advancing direction line that is perpendicular to the center line in the width direction of the steel piece 11, and the horizontal blade 12 moves the cutting edge 12c along this cutting edge advancing direction line 13 by a drive device such as a hydraulic cylinder (not shown) to move the steel piece 11. It is configured to enter toward the center in the width direction.

On the other hand, on both sides of the steel piece 11 in the thickness direction, there are
A pair of vertical blades 14 having the same width as y are disposed with their cutting edges facing each other, and the tip of the vertical blade 14 is connected to the cutting edge 15 corresponding to the widthwise center of the steel piece 11. and pressing portions 16 corresponding to both ends of the steel piece 11 in the width direction.

The cutting edge portion 15 is formed into a two-stage V-shape with a V-shaped portion consisting of inclined surfaces 15a and 15b and a V-shaped portion consisting of continuous inclined surfaces 15c and 15d. , is formed into a rectangular plate shape with a suppressing surface 16a parallel to the surface of the steel piece 11. The chain line 17 is the steel piece 11
A cutting edge advancing direction line perpendicular to the thickness direction center line,
The vertical blade 14 aligns the cutting edge 15e along the cutting edge advancing direction line 1T using a drive device such as a hydraulic cylinder (not shown) to cut the steel piece 1.
It is configured to enter toward the center in the thickness direction of 1. Then, the pressing part 16 presses the pressing surface 1 slightly before the rain vertical blade 14 enters the steel piece 11 and the blade edges 15e come into contact with each other.
6a presses the surface of the steel piece 11, so that its position is set.

The fourth method of push-cutting using the device configured as described above is as follows.
This will be explained based on FIGS. (a) to (f). In addition, Figures 4 (d) to (C) are plan views and do not show the vertical blades, and Figures 4 (d) to σ) are front views and do not show the horizontal blades. It is. From the state shown in FIG. 4(a), move the horizontal blade 12 forward along the cutting edge advancing direction line 13, and
As shown in Figure (b), it is made to enter about 20 to 30% of the width of the steel piece 11 toward the center of the steel piece 11 in the width direction. and the fourth
As shown in Figure (c), when the horizontal blade 12 is retreated from the steel piece 11, the steel piece 11 has a notch 11. is formed. Fourth
Figure (The ridges indicate the front view of this state. From this state, when the vertical blade 14 is advanced along the cutting edge advancing direction line 17, the cutting edge 15 comes into contact with the steel piece 11 and starts pushing. As the injection into the steel slab 11 progresses, the inclined surface 15
a, 15b wedge action and subsequent inclined surface 15
A force in the longitudinal direction acts on the steel piece 11 due to the wedge action of c and 15d, and the tensile stress in the uncut portion reaches the yield stress, causing plastic deformation. As the injection further progresses, the tensile displacement in the longitudinal direction acting on the uncut portion at the center of the width of the steel billet 11 increases, and the distance between the cutting edges 150 of the rain vertical blades 14 reaches a preset distance. When the pressing surface 16a is pressed against the steel piece 11, the vertical blade 14 is pressed before the cutting edge 15e collides.
When the steel plate 11 stops, a constriction is created inside the connection left in this lessee interval, and the steel piece 11 is cut.

4th figure) is a plan view showing the cut end of the cut steel piece 11, and in this method, a V-shaped horizontal blade 12 is pushed in from the horizontal direction to cut the notch 11. As a result, the cut end is preformed to have a trapezoidal shape in plan view, and further, by pushing the vertical blade 14 from the vertical direction and cutting, the cut end is formed in a V-shape in side view. . Further, since the vertical blade 14 is provided with the suppressing portion 16 to press the notch 11a, no swelling of meat occurs around the notch 11.0, and the surface of the cut end becomes flat.

In this embodiment, an example is shown in which the horizontal blade 12 is a one-stage V-shaped blade and the vertical blade 14 is a two-stage V-shaped blade. The blade 14 may be a single-stage V-shaped blade, or a horizontal blade 12. Both of the vertical blades 14 may be one-stage V-shaped blades or two-stage V-shaped blades. Of course, other shapes may be used as long as the blade is 11'; V-shaped. Further, in this embodiment, an example is shown in which the pressing portions 16 of the vertical blade 14 are provided only on both sides of the steel piece 11 in the width direction, but it will be more effective if they are provided on both sides of the steel piece 11 in the longitudinal direction with respect to the blade 15. It is true. Furthermore, when pressed by this pressing part 16, the steel piece 11 tends to slide sideways, causing the pressing surface 16
Frictional resistance occurs between
It is more effective if only the pressing surface 16a side of the steel piece 11 can be moved in the longitudinal direction of the steel piece 11. Further, in this embodiment, an example was shown in which the vertical blade 14 is integrally formed with the blade 15 and the pressing part 16, but the pressing part 16 is provided separately from the vertical blade 14 and is raised and lowered by a separate drive from the vertical blade 14. You can do it like this.

In that case, when cutting in the vertical direction, the pressing portion 16 is first pressed against the upper and lower surfaces of the steel piece 11, and then the vertical blade 14 is operated to cut the steel piece 11.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a pair of V-shaped blades enters the material to be cut from both sides in the horizontal direction to form a notch, and then the V-shaped blades are retreated to form a notch. By configuring the V-shaped blade to enter the material to be cut from the perpendicular side and cut it, the cut end of the material to be rolled after cutting is formed into a trapezoidal shape in plan view, and further shaped into a V shape in side view.
Since it is formed into a letter shape, even when it is rolled, fishtails and flaws do not occur at the rolled end, and the yield of the product is greatly improved.

FIG. 2 is a side view of a material to be cut and a cutting blade for explaining the push-cutting method according to the present invention, FIG. 3 is a plan view of the same, and FIGS. 4(a) to (f) are Similarly, the operation explanation diagram,
Figure 4) is a plan view of the cut end of the steel piece.

11... Steel piece, 11a... Notch, 12 horizontal blade, 14 -... Vertical blade.

Patent applicant Ube Industries Co., Ltd. Representative Kazuyuki Yamakawa (#1 or 2) 11- Figure 1

Claims (1)

[Claims] A pair of V-shaped blades enter the widthwise center of the material to be cut from both sides in the horizontal direction to create a notch, and after retracting the V-shaped blades, insert the pair of V-shaped blades into the material to be cut. A push cutting method characterized by cutting by entering from both sides in a vertical direction toward the center in the thickness direction.