JPH0675727B2 - Continuous rolling mill using non-driving roll - Google Patents

Description

TECHNICAL FIELD The present invention relates to a continuous rolling mill for hot rolling a bloom made of steel or non-ferrous metal into a billet as a raw material for various products or from the billet to various products. It is a thing.

(B) Conventional technology For example, continuous rolling bloom is usually used in rolling of bar steel. The continuous casting bloom is slab-rolled to a billet at a slab, and after reheating, the billet is rolled into various products at a steel bar factory or a wire rod factory.

A conventional rolling mill in a slab is generally a continuous rolling mill in which horizontal rolling mills and vertical rolling mills are alternately arranged. In this case, both horizontal and vertical rolling mills are being driven. The same applies to steel bars and wire rod factories.

Here, the horizontal rolling mill has a structure in which a pair of work rolls are arranged in parallel to the width direction of the rolled material, and the front and back surfaces of the rolled material are pinched, and a reduction is applied in the thickness direction of the rolled material. I mean what you have. A vertical rolling mill has a structure in which a pair of work rolls are arranged vertically on the surface of the rolled material, and the side surface in the longitudinal direction of the rolled material is sandwiched between the work rolls to apply reduction in the width direction of the rolled material. Say. Here, the driving of the rolling mill means that the work roll is rotationally driven.

Since a vertical rolling mill must have a work roll driving device installed on the upper or lower part of the rolling mill housing, its equipment cost is 3 times that of a horizontal rolling mill of the same power.
More than double. Therefore, the height of the rolling ridge building is increased, each rolling mill is required to be 5 m or more, and the rolling mill length is increased. Not only rolling mill-related costs, but also building-related construction costs will increase.

In order to solve the above-mentioned drawbacks, the applicant of the present invention has disclosed in Japanese Patent Laid-Open No.
Japanese Patent Application No. 7203 (Japanese Patent Application No. 57-70208) proposes that a vertical rolling mill is not driven in a continuous rolling mill in which horizontal rolling mills and vertical rolling mills are alternately arranged. However, simply by not driving the vertical rolling mill, the rolled material buckles between the driven horizontal rolling mill and the downstream non-driving vertical rolling mill, which makes it difficult to continue rolling. Therefore, the surface reduction rate of the non-driven vertical rolling mill is set to 66% or less of that of the upstream driven horizontal rolling mill. In this case, the total rolling reduction in the thickness direction by the horizontal rolling mill becomes nearly twice the total rolling reduction in the width direction by the vertical rolling mill, and when a square billet or product is to be obtained, the material has a square cross section. It is impossible to do so, and it is unavoidable to use a rectangular cross section with a large flatness.

On the other hand, quality requirements for raw materials for bar steel are strict, and reduction of non-metallic inclusions and center segregation is a particular issue. Making the continuous casting bloom of the material into a flat rectangular shape like a slab is unacceptable because it leads to an increase in center segregation. Currently, the general cross-sectional dimension of a bloom is a thickness of 300 mm ×
From width 300 mm to thickness 300 mm x width 400 mm. When such a bloom close to a square is used, it is difficult for the technology of the above-mentioned patent application to be applied to the current rolling.

Therefore, in order to solve the above-mentioned problems, the present applicant discloses in Japanese Patent Laid-Open No. 61-279301 (Japanese Patent Application No. 60-121081):
2n + 1 (n with horizontal and vertical rolling mills alternately arranged
Is a whole number of 1 or more) in a continuous rolling mill having one stand and an odd numbered stand including a first stand and a final stand, and a horizontal rolling mill having a pair of driving horizontal work rolls is arranged, and a second stand is included. A vertical rolling mill equipped with a pair of non-driving vertical work rolls is arranged on even-numbered stands, and the rolled material thickness di between adjacent stands and the axial distance Li between work rolls satisfy the following conditions. Propose to configure.

The conditions are the following expressions (1) and (2).

0.1 <di / Di <0.4 (1) 1.0 <Li / Di <4.0 (2) However, i = 1,2,3, ... n-1 Di = work roll outer diameter However, the above rolling The machine has not been specifically examined how to make the entire structure small and inexpensive.

(C) Problems to be Solved by the Invention A problem to be solved by the present invention is that when a vertical rolling mill is not driven in a continuous rolling mill in which horizontal rolling mills and vertical rolling mills are alternately arranged. In addition, it is to make both rolling mills compact and inexpensive overall, to ensure the material indentation by the driving horizontal rolling mill, and to obtain rolling performance equivalent to that of the conventional all-driving continuous rolling mill.

(D) Means for Solving Problems The present invention relates to a continuous rolling mill using non-driving rolls, which is composed of 2n + 1 (n is an integer of 1 or more) stands in which horizontal rolling mills and vertical rolling mills are alternately arranged. In a continuous rolling mill, horizontal rolling mills with a pair of driving horizontal work rolls are arranged at odd-numbered stands including the first stand and the last stand, and one pair of non-horizontal stands at the even-numbered stand including the second stand. A vertical rolling mill equipped with a driving vertical work roll is arranged, and a pair of horizontal rolls supported by roll chocks and a vertical rolling held by a housing abutting the roll chocks are disposed in a housing of the horizontal rolling mill. By installing a machine, the above problems are solved.

(E) Operation The present invention does not drive the vertical rolling mill, and in order to enable the same reduction as in the case of driving, the rolling mill is supported by rolls and chocks in the housing of the driving horizontal rolling mill. A pair of horizontal rolls and a vertical rolling mill held by a housing abutting the roll chock. In this way, the distance between the roll axes of the rolling mills is shortened, and the non-drive vertical rolling mill can achieve the same area reduction rate as the driven horizontal rolling mill without causing buckling of the material. .

As an example, horizontal / vertical work / roll diameter Di = 300mm,
Horizontal rolling mill Delivery side rolling material thickness di = 80mm (di / Di = 0.267),
Horizontal / vertical work / roll center distance Li = 1300mm, 430m
m (Li / Di = 4.33,1.403) Rolling temperature of 1100 ℃, Rolling of low carbon killed steel rolled material, the relationship between the reduction rate of the driven rolling mill and that of the non-driven rolling mill Are shown in FIGS. 3 and 4, respectively. FIG. 3 shows the case of a continuous rolling mill in which the vertical rolling mill is not driven and is provided outside the housing of the horizontal rolling mill, and FIG. 4 shows the case of the continuous rolling mill of the present invention.

In the case of a Li = 1300 mm (Li / Di = 4.33) rolling mill, the reduction rate of vertical rolling mill is about 70% of that of horizontal rolling mill (3rd
Figure). On the other hand, in the case of the rolling mill of the present invention with Li = 715 mm (Li / Di = 2.38), it is possible to reach 100% (Fig. 4).

After the rolled material is released from the driven horizontal rolling mill into which the rolled material has been pushed, the rolled material is pulled out from the non-driven vertical rolling mill by the driven horizontal rolling mill installed downstream of the non-driven vertical rolling mill. In this case, a tensile force acts on the material, and whether or not the material can be rolled is determined by whether or not slippage occurs in the drive horizontal rolling mill.

The prevention of slippage can be easily solved by increasing the contact area between the work roll and the rolled material, roughening the surface of the roll, and increasing the friction coefficient between the roll and the rolled material. In particular, even if the box hole type is used and only the side surface of the rolled material is restrained, the slip prevention effect is enhanced.

In the present invention, another reason why the axial distance between the horizontal roll and the vertical roll is shortened is as follows.

The rolling force pushes into the vertical rolls due to the driving force of the horizontal rolls, and only repulsive forces are generated between the horizontal rolls and the vertical rolls. Therefore, a member for supporting the horizontal force on the vertical roll side of the roll chock of the horizontal roll is unnecessary, and only the elevating guide of the roll chock of the horizontal roll is required. Therefore, as shown in FIG. 5, it is sufficient that the member for connecting the upper and lower chocks of the vertical roll is thin. Therefore, the distance between the horizontal rolls and the vertical rolls is very small, and the buckling of the material between the rolls during rolling can be prevented.

Further, since the distance between the roll shaft centers becomes small, buckling can be prevented, and a high area reduction rate can be obtained. The reason will be described below. Usually, the relationship between the roll gap and the buckling of the material when the roll is pushed into the vertical roll by a horizontal roll, the buckling limit stress becomes very small as the roll gap becomes longer, and falls below the deformation resistance of the rolled material. Therefore, although the rolled material itself has a sufficient compressive strength, it cannot be rolled at a low pressure reduction rate. On the contrary, by making the roll interval small, the buckling limit stress becomes large, and indentation rolling can be performed up to the limit of compressive strength. The non-driving vertical rolling mill of the present invention can obtain an area reduction rate substantially equal to that of the driving horizontal rolling mill.

(F) Embodiment FIG. 1 shows a minimum unit continuous rolling mill 10 in which a driving horizontal rolling mill 1 and a non-driving vertical rolling mill 2 are incorporated in the same housing 3 according to the present invention. A horizontal rolling mill 1 and a vertical rolling mill 2 are arranged from the upstream side with respect to the pass line P of the rolled material.

For comparison, the minimum unit continuous rolling mill 10 'in which the non-driving vertical rolling mill 2 is installed outside the horizontal rolling mill housing 3 is shown in FIG.
Indicates. The housing 3a of the driving horizontal pressure rolling mill 1 and the housing 3b of the non-driving vertical rolling mill 2 are made separately and are connected to each other.

5 to 7, the minimum unit continuous rolling mill 10 of the present invention is shown.
The detailed structure of is shown. FIG. 5 is a side view, FIG. 6 is a front view, and FIG. 7 is a plan view.

The driving horizontal rolling mill 1 is arranged on the rolled material entrance side of the housing 3, and the non-driven vertical rolling mill 2 is arranged on the exit side thereof.
The horizontal roll 12 is supported by the roll chock 11. The housing 21 of the non-driving vertical rolling mill 2 is fixed to the housing 3 on the exit side of the rolling material pass line P by abutting on the roll chock 11.

In the housing 21, a roll chock 22 supports a non-driven vertical roll 23.

The screw roll adjustment device installed between the upper roll chock 11a and the housing 3 adjusts the reduction of the horizontal roll 12.
Adjusted by 13. The non-driven vertical roll 23 is similarly adjusted by the screw edge device 24 installed between the left and right vertical rolls 23 and the housing 21.

The continuous rolling mill according to the present invention was installed in a rough rolling mill train of continuous rolling mills for rolling a 115 mm square billet to a steel bar having a diameter of 10 mm, and production was carried out. As a result, it was confirmed that the same area reduction rate as that of the driven horizontal and vertical rolling mill can be stably obtained.

(G) Effect According to the present invention, since the vertical rolling mill is not driven, the entire equipment can be downsized, the cost can be reduced, and a rolling pattern substantially equivalent to that in the case of driving can be realized. Applicable to Further, when the rolls are replaced for maintenance, the horizontal and vertical rolls can be easily attached to and detached from the housing as a unit.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of a minimum unit continuous rolling mill of the present invention. FIG. 2 is a side view of the minimum unit continuous rolling mill. FIG. 3 is a graph showing the relationship between the reduction ratios of the driving and non-driving rolling mills in the continuous rolling mill in which the non-driving vertical rolling mill is installed outside the horizontal rolling mill housing. FIG. 4 is a graph showing the relationship between the reduction ratios of the driven and non-driven rolling mills in the continuous rolling mill of the present invention. FIG. 5 is a side view of the minimum unit continuous rolling mill of the present invention. FIG. 6 is a front view seen from the line VI-VI in FIG. FIG. 7 shows the fifth
The top view seen from the VII-VII line of a figure. 1: driven horizontal rolling mill 2: non-driven vertical rolling mill 3: housing 11: roll chock, 22: housing

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Muraguchi 5-2 Sokai-cho, Niihama-shi, Ehime Sumitomo Heavy Industries Machinery Co., Ltd. Niihama Works (56) Reference JP-A-61-279301 (JP, A) Japanese Patent Publication No. 49-8787 (JP, B1) Actual application No. 59-37250 (Actual application No. 60-151603) Micro film (JP, U) taken from the specification and drawings attached to the application

Claims (1)

[Claims] 1. A continuous rolling mill comprising 2n + 1 (n is an integer of 1 or more) stands in which horizontal rolling mills and vertical rolling mills are alternately arranged, and a pair of odd numbered stands including a first stand and a final stand. Horizontal rolling mill with driven horizontal work rolls, and vertical rolling mill with a pair of non-driving vertical work rolls on even numbered stands including the second stand, horizontal rolling mill housing Within
A continuous rolling mill using a non-driving roll, comprising a pair of horizontal rolls supported by roll chocks and a vertical rolling mill held by a housing that abuts on the roll chocks.