JPH06226308A - Edging method with press - Google Patents

Abstract

PURPOSE:To provide an edging method with a press by which preformed parts at the tip and rear end where it is necessary to reduce the crop loss in a rolling stage are edged with small capacity press. CONSTITUTION:When the tip 1a of a slab is situated in the parallel part 11 of a die 10, the slab is stopped and edged into a wide width Wt at several times. In this way, the preformed part 2 at the tip is formed into a wide width Wt by reducing the edging amount St per one time and also the intermediate part 1c and the preformed part 3 at the rear end are formed by small edging amount S, Sb by repeating the feed L of the slab 1 and the edging of edging width W. It is not necessary to increase the capacity of the press in accordance with the preformed parts at the tip and rear end and the slab of a prescribed edged-shape is obtained with the small press.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a width reduction method by a press, and it is possible to reduce the width of the preforming portions at the front and rear ends necessary for reducing the crop loss in the next rolling step with a press having a small capacity. It was done.

[0002]

2. Description of the Related Art Instead of the conventional width forming of a slab by a sizing mill, the width of the slab is reduced by using a press to form the slab into a shape required in the next rolling step.

In the width reduction by pressing such a slab, various width reduction shapes have been studied because it is necessary to minimize the crop loss generated at the leading and trailing ends in the rolling process, for example, as shown in FIG. 3 (a). As described above, the pre-forming portions 2 and 3 that make the front and rear ends 1a and 1b of the slab 1 wider than the intermediate portion 1c are formed so as to prevent a shortage of width that occurs slightly inside from the front and rear ends 1a and 1b, or conversely. Figure 3
As shown in (b), preforming portions 4 and 5 that make the front and rear ends 1a and 1b of the slab 1 narrower than the intermediate portion 1c are formed to prevent fish tails and the like from occurring. .

As a width reduction method for forming the preformed portions at the front and rear ends of such a slab, for example, as shown in FIG. 4 in which the wide preformed portions 2 and 3 are formed, the parallel portion 6 and the taper portion are formed. Using a pair of molds 8, 8 having
While feeding, the width reduction is performed between the molds 8 having a predetermined reduction width.

As a technique related to such width reduction, Japanese Patent Laid-Open No. 61-135402 and Japanese Patent Laid-Open No. 63-135402.
There is an invention described in Japanese Patent No. 140701 and the like (none of the inventions disclosed in these publications is intended to make the width reduction amount of the present application uniform).

[0006]

However, when the preforming portions 2 and 3 of the front and rear ends 1a and 1b of the slab 1 are width-reduced,
Especially when the slab tip 1a is width-reduced, the slab tip 1a
If the slab 1 is pushed back by the taper portion 7 when an attempt is made to reduce the width of the slab while it is positioned on the taper portion 7 of the dies 8, 8, the slab tip 1a cannot be effectively reduced. It is necessary to feed it to the parallel portion 6 over the width and press the parallel portion 6 to perform width reduction.

Therefore, the width reduction amount S1 required for the reduction of the slab tip 1a is the steady width reduction amount S of the intermediate portion 1c.
There is a problem in that the presser having a capacity corresponding to the width reduction amount S1 of the slab tip 1a is required to be considerably larger.

Similarly, the width reduction amount S2 of the preforming portion 3 of the slab rear end 1b also becomes large.

The present invention has been made in view of the problems of the prior art, and the width reduction of the preforming portions at the front and rear ends necessary for reducing the crop loss in the next rolling step is performed by a press having a small capacity. It is intended to provide a width reduction method by a press capable of

[0010]

In order to solve the problems of the above-mentioned prior art, the first method for width reduction by the press of the present invention is a slab using a pair of molds having a parallel portion and a taper portion. When pressing the wide preforming part at the front and rear ends with the press, the slab tip is positioned in the parallel part of the mold and stopped, and the wide wide preforming part wider than the middle part is formed under multiple width reductions. Then, the slab feed and width reduction are repeated by setting the reduction width to a predetermined width narrower than the front and rear ends with respect to the middle part,
The present invention is characterized in that a rear end wide preform portion wider than the middle portion is formed when the length to the rear end of the slab reaches a predetermined length.

In addition to the structure of the first aspect of the invention, the width reduction method by the second press of the present invention is such that, after forming the tip wide preform of the slab, the slab is fed to make the width narrower than the front and rear ends. When the intermediate portion is molded, after the width is reduced once by the reduction width of the front end preforming portion, the width reduction of the width narrower than the front and rear ends with respect to the intermediate portion is repeated.

Further, according to the third press width reduction method of the present invention, a narrow preforming portion is press-pressed at the slab front and rear ends by using a pair of molds having a parallel portion and a taper portion. At this time, the slab tip is positioned at the parallel part of the mold and stopped, and a narrow narrow tip preform part is formed from the middle part under multiple width reductions, then the reduction width is wider than the front and rear ends to the middle part. The slab feed and width reduction are repeated as the predetermined width of, and the slab is stopped when the length to the rear end of the slab reaches the predetermined length and the width is reduced once or when it reaches the predetermined length. It is characterized in that the rear end narrow preform portion having a width narrower than that of the intermediate portion is formed under a plurality of width pressures.

In addition to the structure of the third aspect of the invention, in the width reducing method by the fourth press of the present invention, the slab is fed after the narrow narrow preforming part of the slab is formed and the middle part is moved to the front and rear end parts. When forming a wider intermediate portion, the width is reduced once by the reduction width of the tip preforming portion, and then the width reduction wider than the tip with respect to the intermediate portion is repeated. .

[0014]

According to the first press width reduction method of the present invention, the slab tip is positioned at the parallel portion of the mold and stopped,
Wide width reduction is performed in multiple steps, so that even if the slab tip is positioned in the parallel part of the mold, the width reduction amount per operation can be made small so that the tip preform part can be formed wide. In addition, the middle part and the rear end preforming part can be formed with a small width reduction amount by repeating the feeding of the slab and the width reduction.

Further, according to the width reduction method by the second press of the present invention, the tip preforming portion is divided into a plurality of times to be widened, and then the width of the intermediate portion is reduced once by the reduction width. The reduction is repeated so that the transition from the tip preforming portion to the intermediate portion can be smoothly performed.

Further, according to the third press width reduction method of the present invention, the slab tip is positioned at the parallel portion of the die and stopped, and the width reduction is performed in a plurality of times to narrow the width. , Even when the slab tip is located in the parallel part of the mold, the width reduction amount per operation is made small so that the tip preforming part can be formed to a narrow width, and the middle part also feeds the slab and reduces the width. Can be molded with a small width reduction by repeating
The rear end preforming portion is also divided once or plural times so that the width is reduced to a narrow width so that molding can be performed with a small width reduction amount.

Further, according to the fourth press width reduction method of the present invention, the tip preforming portion is divided into a plurality of times into a narrow width, and then the reduction width is reduced once, and then the intermediate portion. The width reduction is repeated so that the transition from the tip preforming portion to the intermediate portion can be smoothly performed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic process diagram according to an embodiment of a width reduction method using a press according to the present invention.

In the width reduction method by this press, as shown in FIG.
As shown in (a), the front and rear ends 1a and 1b of the slab 1 have wide widths Wt and Wb and lengths Lt and Lb.
3, a pair of molds 10 is used for width reduction, as shown in FIG. These molds 1
0 has a taper portion 1 on the upstream side of the parallel portion 11 having a length L1.
2 is formed, and the tapered portion 13 is also formed on the downstream side.

First, in forming the tip preforming section 2,
The tip 1a of the slab 1 is stopped at the position L2 from the end of the parallel portion 11 on the upstream side of the mold 10, and the width reduction amount St per stroke is the middle portion as shown by the broken line in FIG. 1 (a). The width is reduced to a predetermined tip preforming width Wt by changing the reduction width once or a plurality of times so as not to exceed the steady width reduction amount S.

Next, as shown in FIG. 1B, the slab 1
By L3 so that the length from the downstream end of the parallel portion 11 of the die 10 to the tip 1a of the slab 1 becomes the length Lt of the tip preforming portion 2, and the reduction width by the die 10 is The width reduction is performed by changing the width to a predetermined width W of the intermediate portion 1c.

As a result, a tip preforming portion 2 having a wide width Wt and a length Lt is formed on the tip 1a of the slab 1.

When forming this tip preforming portion 2,
When the elongation of the slab 1 by the press is ΔL, there is the following relationship.

L2 + L3 + ΔL = Lt + L1 L3 = Lt + L1− (L2 + ΔL) After that, in order to perform the width reduction of the intermediate portion 1c of the slab 1, the slab 1 is fed by L and the reduction width by the die 10 is W. The width reduction amount is set to S, and the width reduction is repeated.

After the width reduction of the slab 1 is performed in this way,
The width reduction of the rear end preforming portion 3 is performed. As shown in FIG. 1 (c), first, the rear end 1b of the slab 1 is pressed down from the upstream end of the parallel part 11 of the mold 10 to the position L4. Detected press points. This L4
Is the normal feed amount L of the slab 1 and the length L of the rear end preforming part 3
The point is equal to or smaller than the value obtained by adding b, that is, the point satisfying the relation of the following equation.

L4≤L + Lb When the width is reduced to the pressing point of L4, the feed amount of the next slab 1 is set to L7, and the reduction width of the die 10 is changed to a wide Wb to perform width reduction.

Thereafter, as shown in FIG. 1 (d), the slab 1 is further fed and the rear end 1b is pressed by the parallel portion 11 of the die 10 while keeping the reduction width Wb, and the rear end preforming portion 3 is formed. Formation is complete.

As a result, the rear end 1b of the slab 1 is formed with the rear end preforming portion 3 having a wide width Wb and a length Lb. The width reduction amount of the trailing edge preforming portion 3 is Sb.

When the trailing edge preforming portion 3 is formed,
Elongation of slab 1 by press is ΔL, constant is C (= 25〜
50 mm), as shown in FIGS. 1 (c) and 1 (d), the following relationship is established.

L5 = L4- (Lb + .DELTA.L) .ltoreq.L L4 .ltoreq.L + Lb + .DELTA.L L7 = Lb + .DELTA.L + C When the molding of the tip preforming section 2 is shifted to the steady molding of the intermediate section 1c, as shown in FIG. 1 (b1), As shown in (b2),
The slab 1 is fed by L3 from the state in which the tip of the slab 1 is stopped, and the width is reduced once with the reduction width kept wide Wt. After that, the reduction width is reduced to the middle part 1 with the slab 1 stopped.
Width reduction is performed with W being a predetermined width of c.

After that, in order to perform the width reduction of the intermediate portion 1c of the slab 1, the slab 1 is fed by L and the width reduction by the die 10 is set to W and the width reduction is repeated.

By performing the width reduction once with such a wide width Wt and then performing the width reduction of the intermediate portion 1c, the width reduction amounts S1 and S2 are made smaller than the steady width reduction amount S. You can press smoothly.

In this way, the width reduction of the front end preforming portion 2 and the rear end preforming portion 3 is performed by the press, so that the width reduction amount St, Sb, S1, S2 per one time is constantly reduced. It can be pressed with a size equal to or smaller than S,
It is not necessary to make the press capacity large corresponding to the front and rear end preforming portions 2 and 3, and it is possible to obtain the slab 1 having a predetermined width reduction shape with a small press.

Next, with reference to the schematic process diagram shown in FIG. 2, description will be given of a case where a narrow preforming portion is formed at the front and rear ends of the slab according to another embodiment of the width reduction method by the press of the present invention.

In the case where the preforming portions 2 and 3 having the narrow widths Wt and Wb (<W) are width-reduced at the front and rear ends 1a and 1b of the slab 1 as shown in FIG. Although the reduction width is different, the process itself is almost the same as that of the embodiment of the invention.

First, in forming the tip preforming section 2,
The tip 1a of the slab 1 is stopped at the parallel part 11 on the upstream side of the mold 10, and as shown by the broken line in FIG. 2 (a), the width reduction amount St per operation is the steady width reduction amount S of the middle part. The reduction width is changed once or a plurality of times so as not to become larger, and the width is reduced to a predetermined tip preforming width Wt (<W).

Next, as shown in FIG. 2B, the slab 1
Is fed to the tip 1a of the slab 1 so as to form the tip preforming section 2 having a predetermined length Lt, and the reduction width by the die 10 is changed to a wide width so as to have the predetermined reduction width W of the intermediate section 1c and the width reduction is performed. I do.

As a result, at the tip 1a of the slab 1, a tip preforming portion 2 having a narrow width Wt and a length Lt is formed.

After that, in order to perform the width reduction of the intermediate portion 1c of the slab 1, the slab 1 is fed by L and the width reduction by the mold 10 is set to W and the width reduction amount is set to S, and the width reduction is repeated.

After the width reduction of the slab 1 is performed in this way,
The width reduction of the rear end preforming portion 3 is performed. As shown in Fig. 2 (c), first, the width reduction of the rear end preforming portion 3 is performed by reducing the width of the rear end 1b of the slab 1 from the downstream end of the parallel portion 11 of the mold 10 to a predetermined position. The pressed position, that is, the elongation ΔL due to the press is added to the rear end to obtain the length L of the rear end preforming portion 3.
Stop the slab 1 at the press position where b is formed, and
As shown by the broken line in (c), the width reduction amount S per operation
The width is reduced to a predetermined tip preforming width Wb (<W) by changing the reduction width once or a plurality of times so that b does not become larger than the steady width reduction amount S of the intermediate portion.

Thereafter, as shown in FIG. 2 (d), the slab 1 is further fed and the rear end 1b is pressed by the parallel portion 11 of the mold 10 while keeping the reduction width Wb and the rear end preforming portion 3 is formed. Formation is complete.

As a result, the rear end 1b of the slab 1 is formed with the rear end preforming portion 3 having a narrow width Wb and a length Lb.

From the molding of the tip preforming section 2 to the intermediate section 1
When shifting to the steady forming of c, as shown in FIGS. 2 (b1) and (b2), the slab 1 is fed from the state in which the tip of the slab 1 is stopped, and the rolling width is set to a narrow width Wt 1 Rolling width reduction is performed, and thereafter, with the slab 1 stopped, the reduction width is set to W which is a predetermined width of the intermediate portion 1c.

Thereafter, as shown in FIG. 2C, the slab 1 is fed by L in order to reduce the width of the intermediate portion 1c of the slab 1, and the reduction width by the die 10 is set to W and the width reduction is repeated. To do so.

By performing the width reduction once with such a narrow width Wt and then performing the width reduction of the intermediate portion 1c, the width reduction amounts S1 and S2 are less than the steady width reduction amount S. It can be made small and press can be done smoothly.

In this way, the widths of the front end preforming portion 2 and the rear end preforming portion 3 are reduced by the press, so that the width reduction amounts St, Sb, S1, S2 per one time are constantly reduced. It can be pressed with a size equal to or smaller than S,
It is not necessary to make the press capacity large corresponding to the front and rear end preforming portions 2 and 3, and it is possible to obtain the slab 1 having a predetermined width reduction shape with a small press.

The present invention is not limited to the above embodiment,
It goes without saying that each constituent element may be changed without departing from the scope of the present invention.

[0048]

As described above in detail with reference to the embodiment, according to the width reduction method by the first press of the present invention, the slab tip is positioned at the parallel part of the die and stopped.
Since the width is widely reduced in multiple steps, the width of each slab tip should be reduced even when the tip of the slab is positioned in the parallel part of the mold, and the tip preforming part should be formed wide. In addition, the intermediate portion and the rear end preforming portion can be formed with a small width reduction amount by repeating the feeding of the slab and the width reduction.

Further, according to the width reduction method by the second press of the present invention, the tip preforming portion is divided into a plurality of times to be widened, and then the width of the intermediate portion is reduced once by the reduction width. Since the reduction is repeated, the width reduction amount at the time of the transition from the front end preforming portion to the intermediate portion can be further reduced and the transition can be smoothly performed.

Further, according to the third press width reduction method of the present invention, the slab tip is positioned at the parallel portion of the mold and stopped, and the width reduction is performed in a plurality of times in a narrow width. Even when the slab tip is positioned in the parallel part of the mold, the width reduction per operation can be reduced to form the tip preforming part with a narrow width, and the middle part can also feed the slab and reduce the width. Can be molded with a small width reduction by repeating
The trailing end preforming portion can also be formed once or a plurality of times so as to be narrowed in a narrow width, and can be molded with a small width reduction amount.

According to the fourth width reduction method by the press of the present invention, the tip preforming portion is divided into a plurality of times to be narrowed, and then the reduction width is reduced once, and then the intermediate portion is reduced. Since the width reduction is repeated, the width reduction amount at the time of the transition from the front end preforming portion to the intermediate portion can be further reduced and the transition can be performed smoothly.

According to any of the first to fourth inventions, when the front end preforming portion and the rear end preforming portion are width-reduced by a press, the width reduction amount per operation is defined as a steady width reduction amount. The slabs can be pressed with the same or smaller size, and the capacity of the press does not have to be large corresponding to the front and rear end preforming parts, and a slab having a predetermined width reduction can be obtained with a small press.

[Brief description of drawings]

FIG. 1 is a schematic process drawing according to an embodiment of a width reduction method by a press according to the present invention.

FIG. 2 is a schematic process drawing according to another embodiment of the width reduction method by the press of the present invention.

FIG. 3 is an explanatory view of a slab shape subjected to width reduction by a width reduction method using a press according to the present invention.

FIG. 4 is a schematic explanatory view of a width reduction method by a conventional press.

[Explanation of symbols]

 1 Slab 1a Slab tip 1b Slab rear end 2 Tip preforming part 3 Rear end preforming part 10 Mold 11 Parallel part 12,13 Tapered part Wt Tip reduction width Wb Rear end reduction width W Intermediate reduction width Lt Tip Pre-forming part length of Lb Pre-forming part length of rear end L Normal feed amount of slab S Normal width reduction amount of slab St One width reduction amount of tip Sb One width reduction amount of rear end S1, S2 Slab width reduction

Claims (4)

[Claims] 1. A pair of molds having a parallel portion and a taper portion is used to press down a wide preforming portion at the front and rear ends of a slab with a press to position the tip of the slab at the parallel portion of the mold. Stop to form a wide front end preform that is wider than the middle part under multiple width reductions, and then repeat the slab feed and width reduction by setting the reduction width to a predetermined width that is narrower than the front and rear ends of the middle part. A width reduction method by a press, characterized in that a wide width preforming portion of a rear end, which is wider than an intermediate portion, is formed when a length to an end reaches a predetermined length. 2. After the forming of the wide tip preforming portion of the slab,
When the slab is sent to form an intermediate portion having a width narrower than the front and rear ends, the width is reduced once by the reduction width of the front end preforming portion, and then the width reduction is narrower than the front and rear ends with respect to the intermediate portion. The width reduction method by a press according to claim 1, wherein 3. A pair of molds having a parallel portion and a taper portion is used to press down a narrow preforming portion at the front and rear ends of the slab with a press so that the tip of the slab is positioned at the parallel portion of the mold. Then stop and form a narrow narrow tip preforming part that is narrower than the middle part under multiple width reductions, then repeat the slab feed and width reduction with the reduction width set to a predetermined width wider than the front and rear ends for the middle part, After the width to the rear end of the slab reaches the specified length, perform one width reduction or stop the slab when the length reaches the specified length, and after narrowing the width several times, narrower than the middle part A width reduction method by a press, characterized in that a narrow end width preforming portion is formed. 4. After molding of the narrow preform for the tip of the slab,
When the slab is sent to form the middle part that is wider than the front and rear end parts, the width is reduced once by the reduction width of the tip preforming part, and then the width reduction wider than the tip to the middle part is repeated. The width reduction method by a press according to claim 3, wherein