JP3223935B2 - Width reduction press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a width reduction press device, and more particularly to a width reduction press device for reducing the width of a slab material using a press.

[0002]

2. Description of the Related Art In order to improve the yield reduction due to the spread of continuous casting of slabs and the accompanying subdivision of slab width types, it is necessary to strongly reduce the slab width. became. In this reverse width rolling, a crop portion such as a fish tail is formed at the rear end of the slab at the rear end of the slab as the number of reverse passes increases, which often causes a reduction in yield.

[0003] Therefore, it has been proposed to perform slab width forming by using a press device instead of a sizing mill. The slab is intermittently fed to a press die portion, and the slab is stopped during pressing. In addition, there has been developed a start-stop type width reduction press apparatus in which the press die is pressed while moving the slab in accordance with the slab speed while continuously feeding the slab.

[0004] Such a sizing mill or a width reduction press device contributes to improvement of quality by compressing internal defects such as sacks (voids) generated in the slab in continuous casting because the slab is strongly reduced in the width direction. It was thought that. Japanese Patent Publication No. 58-215205 and Japanese Patent Publication No. 58-3442 describe sizing mills.
No. 0-121001 describes a width reduction press device.

[0005]

However, under the width pressure of the sizing roller of the sizing mill, no compressive stress is generated in the slab feed direction at the center of the slab in the width direction.
Rather, a tensile stress was generated, and it was impossible to compress the Zaku. Also, in the case of the width reduction press, the width reduction amount is larger than that of the sizing mill, so the tensile stress generated in the slab feed direction at the center of the slab width direction is significantly reduced. And Zaku could not be completely pressed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and improves the quality by compressing a zig or the like inside a slab by applying a width reduction press while applying a compressive stress in the slab feed direction. In addition, it is an object of the present invention to provide a width-reduction press device in which the amount of backward movement at the time of pressing is reduced, whereby the material flow to the front (outside of the mold) is promoted and molding with high elongation efficiency is possible. I do.

[0007]

According to the present invention, a slab pushing device comprising a hydraulic cylinder device is provided at the rear end of the slab on the entry side of the width reducing press die, and the slab pushing device is used at the time of the width reducing press. The present invention provides a width reduction press apparatus characterized in that the slab is pressed while generating a compression force in the longitudinal direction of the slab.

[0008]

[0009]

[0010]

When a slab is pressed in the longitudinal direction of the slab by a slab pushing device while the slab is pressed in the longitudinal direction of the slab by a press die for width reduction, the slab is extended in the longitudinal direction of the slab by the pressing action. The compressive stress is applied to the material in the longitudinal direction, the slab width direction ends are better bite into the width reduction press die, and the upper and lower surfaces of both sides of the slab are suppressed from generating dog bones that swell in the width direction. Internal crimping at the center is effectively performed, and the internal quality is improved.

As a slab pushing device, a hydraulic cylinder device is used at the rear end of the slab on the entry side of the width reduction press die, and the hydraulic cylinder device presses the rear end of the slab.
A compressive force is generated in the slab longitudinal direction. Note that a pair of vertical or horizontal pinch rolls may be used together with the hydraulic cylinder device.

[0012]

[0013]

Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of a width reduction press device according to the present invention, in which (a) shows a plan view and (b) shows a side view. At both ends of the slab 1, press dies 4 for width reduction are provided to reduce the width of the slab. A pair of upper and lower main pressing rolls 10 are provided at the center of the slab width between the width reducing press dies 4 to prevent buckling due to width reduction. The main holding roll 10 is pressed by a cylinder 11. A plurality of (two in the present example) upper auxiliary rolls 12 movable in the width direction are provided between the width reduction press dies 4 on the entrance side.
And a cylinder 13 for pressurizing the same. Also,
A plurality of lower auxiliary rolls 14 that can move in a plurality of width directions and a cylinder 15 that presses the lower auxiliary rolls 14 are also provided at the lower portion on the entry side.
The upper and lower auxiliary rolls 12 and 14 are both provided to prevent buckling due to width reduction, but are configured to be able to move independently in the width direction.

A horizontal pinch roll 16 is provided on the entry side of the width reduction press die 4 and is usually used for conveying the slab 1. A hydraulic cylinder device 17 is provided at the rear end of the slab, and the cylinder 18 generates a compressive force in the longitudinal direction of the slab. The rear end position of the slab moves at a predetermined pitch in the slab conveyance direction indicated by the arrow as the width reduction press operation progresses, and the hydraulic cylinder device 17 is also configured to be able to move accordingly. It is also possible to stop the hydraulic cylinder device 17 and generate a longitudinal compressive stress in the material in the mold gap only by the horizontal pinch roll 16.

Next, the operation will be described. The slab 1 is moved by a predetermined pitch in the longitudinal direction by the horizontal pinch roll 16 to the width reduction position, the pressing die 4 for width reduction is pressed in the slab width direction, and the hydraulic cylinder device 17 generates a compressive force in the slab longitudinal direction. Let it. As a result, the end of the slab in the width direction at the end portion in the width reduction press die 4 is improved, and the generation of dog bone is suppressed. At this time, the main holding roll 10 suppresses buckling occurring at the center of the slab width, and the upper auxiliary roll 12 and the lower auxiliary roll 14 are set in advance to optimal positions for preventing buckling in the slab width direction. ,
Reduce buckling. Also, if necessary, use a horizontal pinch roll 1
6 may be driven to generate a frictional force with the slab, thereby generating a compressive force in the slab longitudinal direction. By generating a compressive force in the longitudinal direction of the slab as described above, the Zaku generated mainly at the center in the slab width direction is pressed.

Next, the stress state of the slab according to the present embodiment will be described. FIG. 2 shows a slab internal stress when a width reduction force Pv and a slab pushing force Ph are applied to the slab, σx indicates a slab longitudinal compressive stress, and σy indicates a slab width compressive stress. FIG. 3 is a diagram showing the relationship between the slab pushing force Ph when the width reduction amount is 300 mm and the slab longitudinal compressive stress σx generated at the center of the slab width. Slab width 10
Although the cases of 00 mm and 2000 mm are shown, when the slab pushing force Ph is 0, σx is a tensile stress, and σx changes from a tensile stress to a compressive stress as Ph is increased. The slab pushing force Ph is controlled so that this compressive stress becomes a value for pressing the zigzag.

FIG. 3 shows σx at the center of the slab in the width direction. When the slab pushing force Ph is 0, the distribution of σx in the width direction becomes a tensile stress at the center and a compressive stress as approaching the end. Zack is generated at the time of casting and is concentrated at the center of the slab. Therefore, the slab pushing force Ph may be controlled so that σx at the center presses the zac. Note that σy is a compressive stress over the entire width direction.

[0018]

As is apparent from the above description, according to the present invention, the pressing die for width reduction is pressed in the width direction of the slab, and a compression force is generated in the longitudinal direction of the slab by the slab pushing device to form the dog bone. Generation can be suppressed. In addition, the compression force compresses the backpack mainly generated in the center portion in the slab width direction, so that the internal quality can be remarkably improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a width reduction press device according to an embodiment of the present invention, where (a) is a plan view and (b) is a side view.

FIG. 2 is an explanatory diagram of a force applied to a slab and an internal stress.

FIG. 3 is an explanatory diagram of a slab pushing force and a longitudinal internal stress at a central portion in a slab width direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Slab 4 Press die for width reduction 10 Main press roll 11, 13, 15, 18 Cylinder 12 Upper auxiliary press roll 14 Lower auxiliary press roll 16 Pinch roll 17 Hydraulic cylinder device

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Setuma Matsunuma 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Pref. Ishikawajima-Harima Heavy Industries Co., Ltd. Yokohama No. 2 Factory (56) References JP-A-2-255212 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B21B 15/00 B21B 1/02

Claims (1)

(57) [Claims] 1. The rear end of a slab on the entry side of a width reduction press die.
A slab pushing device comprising a hydraulic cylinder device , wherein the slab pushing device performs the pressing while generating a compressive force in the longitudinal direction of the slab during the width reducing press.