JPS62279021A - Winding method for sheet bar - Google Patents

Abstract

PURPOSE:To contrive prevention, etc. of causing flaws of products by disposing upper bending rolls capable of moving parallelly while keeping a prescribed distance against a lower bending roll, further, by setting an interval of both rolls based on the thickness of sheet bar. CONSTITUTION:On the line passing through the center of the fixed lower bending roll 21 and the contact point of the sheet bar 10, the upper bending rolls 23 capable of moving parallelly keeping the prescribed distance L are disposed on the downstream side. If the prescribed distance L, radii of the rolls R, R are known, when the sheet thickness (t) of a sheet bar 10 is decided, the bending radius is obtained unequivocally as a function of the interval (l). In this way, the interval (l) is decided based on the bending radius (r) and the thickness (t), and the upper binding rolls is positioned to perform the winding. Therefore, the bending radius (r) is always settled, the winding of the coil is performed steadily only by controlling the rotation of one-sided roll, the causing of the slip scratch of the product is prevented.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] This invention is particularly applicable to the hot rolling process of sheet bars.
This is necessary to give the desired bending radius once the sheet bar is rolled up in front of the finishing mill.

This invention relates to a sheet bar winding method that mathematically sets the gap between the lower bending rolls and prevents the sheet bar from being scratched by slipping caused by the upper and lower bending rolls.

[Conventional technology and problems]

Generally, in hot rolling of sheet bars such as copper strips, the second
As shown in the figure, the sheet bar 10 that has passed through the rough rolling mill 12 is transported by conveying table rollers 14, divided by a crop shear 16, and then enters a finishing rolling mill group 18. At this time, the sheet bar 10 waiting for finish rolling
As the waiting time elapses, heat dissipates more at the rear end than at the front end, and the temperature drops significantly. Therefore,
As a method of delaying this temperature drop, for example,
-30028. Tokuko Showa 51-26317゜ Tokuko Showa 514
5304. In Special Publication No. 53-16380, etc.,
It is disclosed that a winding and unwinding device 20 is provided, which winds the sheet bar 10 into a coil shape to obtain a heat-retaining effect before entering the finish rolling process, and unwinds the sheet bar 10 as the preceding process progresses. There is.

In this winding and rewinding device 20, the sheet bar 10
The mutual positional relationship between 21 and 23 of the bending rolls 21, 22, and 23 that provides the curvature for winding it, that is, the relationship between the distance l between the bending rolls 21 and 23 and the bending radius r of the sheet bar 10. is seat bar 10
It was determined based on sensory experience, taking into account the thickness of the surface. Further, appropriate speed correction has not been made for the rotational speed difference (therefore, the circumferential edge speed difference) between the rolls that contact both sides of the sheet bar 10 that occurs when the bending rolls 21 and 23 impart curvature.

As a result, the formation of the innermost diameter of the coil, which is most important when winding the sheet bar 10 into a coil shape stably, becomes uncertain, and the feeding speed of the sheet bar 10 and the
There has been a problem in that slip scratches occur on the sheet bar 10 due to a synchronicity difference between the peripheral speeds of the bending rolls 21 and 23 that are in contact with both surfaces of the sheet bar 10.

This invention has been made in view of these conventional problems, and it solves the above problems by giving a curvature to the sheet bar and by using a method to determine the mutual positional relationship of the lower bending rolls using a mathematical formula. It aims to solve the problem.

[Means for solving problems]

This invention provides a method for winding a sheet bar into a coil while giving a predetermined curvature to the sheet bar using an upper bending roll and a lower bending roll in front of a finishing mill. An upper bending roll that can be moved in parallel at a predetermined distance along a straight line passing through the contact point of the lower bending roll and the lower bending roll is disposed downstream of the lower bending roll, and the upper bending roll and the lower bending roll are arranged based on the thickness of the sheet bar. The specific invention is to set the distance between the rolls, and further based on the curvature of the sheet bar and the thickness of the sheet bar obtained by setting the distance.

Rotational speed difference (or peripheral speed difference) on the lower bending roll
This is a merged invention.

[Effect]

The upper bending roll is arranged so that its center is on a parallel line with a predetermined distance to a straight line passing through the contact point between the center of the lower bending roll whose position is fixed and the sheet bar that approaches at a fixed approach angle. Therefore, the desired bending radius of the sheet bar is determined by keeping the above predetermined distance and the upper and lower bending roll diameters constant.

It can be set as a function using the interval between the lower bending rolls and the sheet bar thickness as variables.

Furthermore, by setting the set bending radius and sheet bar plate thickness as constants, if the rotational speed of either the upper or lower bending roll, and therefore the peripheral speed, is determined, the rotational speed of the other one that does not cause slip (peripheral speed ) can be obtained.

〔Example〕

The present invention will be explained below based on the drawings. FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a hot rolling process common to the conventional example.

In the figure, 21 is a lower bending roll whose position is fixed, and 23 is an upper bending roll. The lower bending roll 21 is disposed downstream in the direction in which the sheet par 10 enters the lower bending roll 21 so that its center is maintained on the parallel line vAm.

22 is a fixed roll that suppresses reaction force when the sheet bar 10 is bent.

Now, let the radii of the upper and lower bending rolls 21 and 23 be R+ and Rz, respectively, and the thickness of the sheet bar 10 be t. and seat bar 1
A = PQ - t subtracting t from the distance below the contact point P with 0
When is the distance between the upper and lower bending rolls, the following relationships hold between the above quantities and the bending radius r.

(Rz + t + r)" = L" + (1+t
+ r)" This is solved for r (and becomes .Here, the predetermined distance R,, Rz are known values, and once the plate thickness t is determined, the bending radius r of this sheet bar is as shown above ( From equation 1), it can be obtained as a function of the interval p.In other words, find the value of l using the desired bending radius r, draw a perpendicular line to the straight line k at the 0 point determined by this l, and connect this perpendicular line to the straight line m. The intersection point is the center position of the upper bending roll 23 where the bending radius γ is obtained.

Also, at this time, the upper and lower bending rolls 21.23
Let the peripheral speeds of the two surfaces of the seat bar 10 be V, Vg, respectively, and the upper surface rotating in contact with both surfaces of the seat bar 10.

It is clear that the condition for not causing slip between the lower bending rolls 21 and 23 can be obtained by satisfying the following relationship. That is, the feeding speed of both sides of the sheet bar 10 given the curvature, and the upper and lower bending rolls 21 and 23.
By synchronizing each of the peripheral speeds vI+ and Z, it is possible to prevent slip damage from occurring.

〔Effect of the invention〕

As explained above, according to the present invention, the sheet bar is wound into a coil shape while being given a predetermined curvature to the sheet bar by an upper bending roll and a lower bending roll in front of a finishing rolling mill. An upper bending roll that can be moved in parallel at a predetermined distance is arranged downstream of the lower bending roll in a straight line passing through the center of the fixed lower bending roll and the point of contact between the sheet bar and the lower bending roll, and The specified invention is to set the interval between the upper bending roll and the lower bending roll based on the thickness of the bar, and furthermore, the interval between the upper and lower bending rolls is determined based on the curvature of the sheet bar obtained by setting the interval and the thickness of the sheet bar. Since the sheet bar winding method is combined with the invention of providing a peripheral speed difference, it is possible to reliably form a coil for winding the sheet bar and to prevent slip damage to the sheet bar.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of an embodiment according to the present invention, FIG. 2 is a schematic diagram of a hot rolling process to which this embodiment is applied, and FIG. 3 is a conceptual diagram of a conventional example. 10... Sheet bar, 18... Finishing rolling machine, 21... Lower bending roll, 23...
...Upper bending roll, P...Contact, k, m...Straight line, L...Predetermined distance,
l... Spacing, t... Seat bar thickness,
vl, v2...peripheral velocity.

Claims (2)

[Claims] (1) In a method of winding a sheet bar into a coil while giving a predetermined curvature to the sheet bar by an upper bending roll and a lower bending roll before a finishing mill, the center of the lower bending roll whose position is fixed and the sheet bar A straight line passing through the contact point between the bar and the lower bending roll,
An upper bending roll that can be moved in parallel while maintaining a predetermined distance is disposed downstream of the lower bending roll, and an interval between the upper bending roll and the lower bending roll is set based on the thickness of the sheet bar. How to wind the seat bar. (2) In a method of winding a sheet bar into a coil while giving a predetermined curvature to the sheet bar by an upper bending roll and a lower bending roll before a finishing mill, the center of the lower bending roll whose position is fixed and the sheet An upper bending roll that can be moved in parallel at a predetermined distance along a straight line passing through the contact point between the bar and the lower bending roll is disposed downstream of the lower bending roll, and the upper bending roll The sheet bar is characterized in that an interval with the lower bending roll is set, and a peripheral speed difference is given to the upper and lower bending rolls based on the curvature of the sheet bar and the thickness of the sheet bar obtained by determining this interval. Winding method.