JPH079020A - Centering method of hot slab - Google Patents

Abstract

PURPOSE:To prevent bending of a hot slab by centering a hot slab without disturbing its transfer and adequately centering during working by hot press. CONSTITUTION:When a hot slab 1 is subjected to centering by a side guide 4 placed at the inlet side of the hot slab 1 in a width press 2, the centering press force applied to the hot slab 1 by the side guide 4 is increased at working of the width press 2 and reduced at not working.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for centering a hot slab, in other words, a method for using a side guide which is disposed on the entrance side of a width press and is used for centering a hot slab. It is applied to hot rolling including sizing process by width press to prevent bending and bending in the longitudinal direction of the slab due to off-center at the slab entry side, which occurs during the sizing process. This effectively avoids the occurrence of troubles in the equipment on the downstream side of the width press due to the bending and the like.

[0002]

2. Description of the Related Art A side guide having an advancing / retreating drive means such as an electric motor or a cylinder has a slightly wider opening than the width of a hot slab passing therethrough, or is in contact with the hot slab. In this case, it is usually used while the hot slab is at rest or on the roller table. It is premised that a centering pressing force is applied to the slab while it is being transported. Therefore, in the conventional side guide, the centering pressing force and the structural strength of the side guide are all set to be commensurate with the weight of the hot slab.

[0003]

By the way, in the sizing process of the hot slab by the width press, the initial posture of the slab, in other words, the initial contact start state between the hot slab and the width press, the deformation resistance of the hot slab During the sizing process, off-centering occurs around the rear end position of the hot slab due to asymmetry in the widthwise position.

In order to sufficiently prevent the off-center and prevent the slab from bending, a large centering pushing force far exceeding the economical and general centering pushing force and structural strength of the side guide. It is necessary to respond to off-center forces with pressure. However, since the centering pressing force and structural strength of the conventional side guides are set to a level commensurate with the weight of the slab, this conventional technology eliminates the off-center that occurs during the sizing process of the hot slab. It is impossible to prevent it, and seriously, there is a problem that the side guide device itself is damaged.

On the other hand, if the centering pressing force of the side guide is sufficiently increased to cope with a large off-center, it is difficult to convey the hot slab sandwiched by the side guide with a large force by pinch rolls or the like. There was another problem with becoming.

The present invention has been made as a result of studies to solve such problems of the prior art, and an object of the present invention is to convey a hot slab not only while it is stationary but also when it is conveyed. In addition, the centering can be performed sufficiently without hindering the transfer work, and the large off-center force generated in the slab due to the sizing process by the width press is sufficiently supported by the side guide with general structural strength. Then, the centering method of the hot slab that can effectively prevent the hot slab from bending and curving.

[0007]

SUMMARY OF THE INVENTION A hot slab centering method of the present invention is characterized in that, for example, when a hot press slab is centered by a side guide of a width press disposed on the inlet side of the hot slab. The centering pressure on the hot slab of the side guides actuated by the fluid or under the combination of it and the electric motor is determined, for example, on the basis of the setting of the fluid pressure in several stages during the action of the width press. This is a method of increasing the timing while matching it, while reducing it when the width press is inoperative, in other words, when the hot slab is being conveyed or stopped.

[0008]

The feature of this centering method is that the hot slab is always subjected to the centering pressing force by the side guide regardless of whether the hot slab is stationary or during the sizing process. That is, in the case where the side guides act in this way, for example, during the sizing process during the action of the width press, the centering pressing force of the side guides is set to the maximum value so that the hot slab is generated by the sizing process. It becomes possible to sufficiently support a large off-center force with the side guides and effectively prevent the hot slab from bending and bending.

On the other hand, when the width press is inactive, the centering pressing force of the side guides is reduced to a level commensurate with the weight of the hot slab, so that the slab weight and the slab acceleration / deceleration conditions are normally set. The slab transportation by the transportation means whose capability is determined in consideration of the above can be sufficiently smoothed.

Therefore, here, the hot slab can be subjected to centering during transportation without causing any trouble in the transportation thereof, and the off-center generated by the sizing thereof can be generally structured. The strong side guides can reliably support the device without damaging the device, and effectively prevent the hot slab from bending or bending.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic side view illustrating an embodiment of the present invention. In the figure, 1 denotes a hot slab, 2 denotes a width press, and this width press 2 is used for a hot slab 1. Sizing is performed to reduce the width. Here, on the inlet side of the hot slab 1 of the width press 2, an inlet side pinch roll 3 as a slab conveying means and a side guide 4 which exerts a centering pressing force on the hot slab 1 are sequentially arranged. Further, on the output side, an output side pinch roll 5 also serving as a slab transfer means is arranged. Under such a device configuration, the side guide 4 functions to regulate the side edge position of the hot slab 1 under a predetermined opening degree, and the pinch rolls 3 and 5 on the inlet side and the outlet side, respectively. Is a hot slab 1
Sandwiching it in its thickness direction, feeding it into the width press 2, and then pulling it out of the width press 2.

As shown in FIG. 2, the side guide 4 is provided with a pair of two side guide beams 11 facing each other, and each beam frame supporting each side guide beam 11. 12, and the rack gears 13 provided at the ends of both beam frames 12 and opposed to each other are meshed with one pinion gear 14, and one of the bead frames 12 is connected to the hydraulic cylinder 15. It can be configured by According to such a configuration,
One bead frame 12 is activated by the operation of the hydraulic cylinder 15.
By advancing and retracting, by the action of both rack gears 13 and pinion gears 14, both bead frames 12, and by extension,
Both side guide beams 11 can be operated synchronously in the direction of approaching and separating from each other. The amount of movement of the side guide beam 11 in this case and the amount of separation displacement of the side guide beam 11 when the side guide beam 11 is pushed away by the hot slab 1 are set, for example, on the cylinder side of the hydraulic cylinder 15. Position sensor
Can be detected by 16.

In carrying out the sizing process of the hot slab by using the apparatus as described above, according to the present invention, the width press 2, the pinch rolls 3, 5 are applied to one hot slab 1.
And each of the sides 4 is actuated, for example as shown in FIG. Note that, here, the centering pressing force of the side guide 4 is changed only in two steps, high and low.

First, the hot slab 1 conveyed on a roller table (not shown) is centered by the side guides 4 at a necessary and sufficiently low centering pressing force under its rest state, and then the hot slab 1 is centered. The hot slab 1 is heated by the roller table and the entry-side pinch roll 3 while the low centering pressing force is applied.
, The operation of the entrance side pinch roll 3 is stopped, the width press 2 is operated in conjunction therewith, and the centering pressing force of the side guide 4 is increased by, for example, a pressure control valve or the like.

After completion of one sizing process by the width press 2, the centering pressing force of the side guide 4 is reduced and the pinch roll 3 conveys a predetermined amount of the hot slab 1 to heat it. The next processing portion of the hot slab 1 is brought to the working position of the width press 1, and thereafter, the same sizing processing is sequentially performed over the entire length of the hot slab 1. In this case, when the slab portion that has been subjected to the sizing process reaches the exit-side pinch roll 5, the hot slab 1 is conveyed under the cooperation of both pinch rolls 3 and 5, and after the slab 1. The end is the entrance side pinch roll 3
After passing through, the slab is conveyed only by the exit side pinch roll 5.

When the centering pressing force of the side guide 4 is controlled in this way, for example, 2000-
The side guide 4 generates an off-center force of several hundred tons that may be generated in the hot slab 1 by the 3000t width press working.
With a high centering pressing force, the hot slab 1 can be effectively prevented from being bent or curved.

On the other hand, the slab conveying force of the pinch roll is, as described above, sufficient to withstand the slab weight and slab acceleration / deceleration conditions, and is generally about 20 to 30 tons in general economical specifications. Therefore, the hot slab 1
When the side guide 4 presses with a large force of several hundred tons, the hot slab 1 cannot be conveyed by the pinch rolls 3 and 5 at all. Therefore, when the hot slab 1 is conveyed after the sizing process by the width press 2 is finished, the centering pressing force of the side guide 4 can be centered on the hot slab 1 and still be conveyed. Reduce it to the extent that it does not cause any problems.

Therefore, according to such a configuration, the off-center force generated by the sizing process of the width press 1 is performed without excessively increasing the structural strength of the side guides 4, in other words, without damaging the side guides. Can be sufficiently supported by the side guides 4, and the hot slab 1 can be smoothly conveyed by the economical pinch rolls 3 and 5 of general specifications.

When the apparatus shown in FIG. 1 is incorporated into the hot rolling process and the centering pressing force of the side guide is controlled according to the above-mentioned point, the No. 3 mil (sizing press) of the rough rolling mill row that follows is controlled. The straightness of the hot slab on the outlet side of the third mill on the further downstream side is shown in FIG. 4 (a) according to the prior art in which the centering pressing force is controlled at a constant low pressure so that the slab can be conveyed by a pinch roll. When it was on the street, it was improved as shown in Fig. 4 (b).

Further, the bending occurrence rate of the hot slab on the outlet side of No. 3 mil was determined, and it was about 5% under the conventional technique, but almost 0% for the method of the present invention. It was solved by. The bending rate is No. 3
It was defined as the ratio of the number of slabs having a bending of 5 mm or more to the total number of hot slabs that passed through the mill.

[0021]

As is apparent from the above description, according to the present invention, in particular, by controlling the centering pressing force of the side guides in a plurality of steps, the off-center force generated by the sizing process by the width press is performed. Can be sufficiently supported without the risk of damage to the side guides to prevent the hot slab from being bent or curved, and the hot transfer of the hot slab can be smoothly performed by an economical general transfer means. Can be secured.

[Brief description of drawings]

FIG. 1 is a schematic line side view illustrating an embodiment of the present invention.

FIG. 2 is a front view illustrating the configuration of a side guide.

FIG. 3 is a graph illustrating a control mode of a centering pressing force of a side guide.

FIG. 4 is a comparative graph of straightness of hot slabs on the exit side of No. 1 mil.

[Explanation of symbols]

 1 Hot slab 2 Width press 3 Input side pinch roll 4 Side guide 5 Output side pinch roll

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuro Shima, 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Prefecture Technical Research Division, Kawasaki Steel Co., Ltd. (72) Sumihiko Ito 1 Kawasaki-cho, Chuo-ku, Chiba Kawasaki Steel Corporation Technical Research Division

Claims (1)

[Claims] 1. When centering a hot slab of a width press by means of side guides arranged on the inlet side of the hot slab, the centering pressing force of the side guide against the hot slab is increased when the width press acts. A method for centering a hot slab, which is characterized by: