JPS5964116A - Coiling method of hot strip - Google Patents

Abstract

PURPOSE:To form a loop at the biting side of pinch rolls and to prevent the slip flaw of pinch rolls generating at the time of slip by decreasing a wrap angle of strip around the pinch roll after the tail end of the strip runs out from a final finish stand. CONSTITUTION:When the tail end of a hot strip 2 runs out from a final finish stand, a driving device 12 of a cylinder 10 is driven by the signal A of a load cell to extend the cylinder 10. And the hot strip 2 at the biting side of upper and lower pinch rolls 5, 4 is raised to form a loop 2' by raising an idle roll 9 to the position where its top end comes into contact with a tangent which touches the lower pinch roll 4 and a deflector roll 6. Thus a wrap angle of the strip 2 around the lower pinch roll 4 is made to approximately zero. Further, the loop 2' is also formed by the deflection due to the bending of strip 2 produced by decelerating the peripheral speed of a table roll 3 though a tension is given to the rear side of the strip 2, to synchronize the strip 2 with the peripheral speed of the roll 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for winding hot strip.

Conventionally, the line arrangement and bamboo after finish rolling in a hot strip mill are as shown in FIG. It is fed out onto a roller 3, bent downward by a lower bending pinch rule 4 and an upper bending pinch roll b of a winder, guided by a deflector roller 6, and wound around a mandrel 7.

In such a hot strip mill, while the trailing portion of the hot strip is being rolled in the finishing mill 1, the winding speed of the hot strip is consistent with the rolling speed. Also,
The tension acting on the hot strip is determined by the winding rotation output of the mandrel 7 since the trailing portion is restrained by the finishing mill 1. After the tail end of the hot strip leaves the final stand of finishing rolling @1, the winding speed is slowed down and finally stopped, but at this time, the tension opposing the winding output of the mandrel 7 As a result, a braking force is applied due to the friction between the hot strip 2, the hot run table reeler 8, and the upper and lower pinch rolls 5, 4. Therefore, if the winding output of the mandrel 7 when the tail end of the hot strip 2 is pulled out of the finishing mill 1 is greater than the braking force due to the above-mentioned friction, there will be a gap between the hot strip 2, the roller 8, and the rolls 4 and 5. If slip occurs and there are protrusions or deposits on the roll, the surface of the hot strip will suffer from scratches due to slip.

This σ (scratch) is influenced by the wrapping angle θ of the hot strip 2 on the lower bending pinch roll 4, and the upper pinch roll 5 and the hot run table roller 3 are in almost point contact with the hot strip as shown in FIG. This prevents scratches from slipping on the hot strip.

As shown in Figure 2, the lower pinch roll 4 is
The IJ knob 2 contacts at a winding angle θ, and this winding angle θ is not affected by the diameter of the lower pinch roll 4, and the common tangent between the lower pinch roll 4 and the deflector roller 6 is the coil 8.
After the point when the tangent line is shared with the outer diameter of , it is determined by the relationship between the lower pinch roll 4 and the deflector roller 60 position f6,
In terms of bending function, the angle is generally around 10° to 200°, and a certain amount is always required.

Regarding the scratches caused by the above-mentioned slip, the slip section length l is determined by the difference in distance traveled by the lower pinch roll and the hot strip per unit time, and this is expressed by the following equation.

l-θd(vp-v8) vS In the above formula, d is the diameter of the lower pinch roll, Vp is the circumferential speed of the lower pinch roll, and vS is the speed of the hot strip.

Therefore, in order to prevent flaws, it is sufficient to set Vp-vs-〇 or θ-0. However, the state of vp-v8-0 is a state without slip, and the lower pinch roll 4
The braking force F including the inertial force is F〈μP, where μ is the friction coefficient between the lower pinch roll 4 and the hot strip 2, and P is the pressing force between the lower pinch roll 4 and the upper hinch roll 5. , μ is not stable, and
When P is increased, the movement of the IJ knob 2 in the width direction is restricted, and the tM of the wound coil is
Since i+ becomes worse, the size of P is limited by a111.

Therefore, setting θ-0 is a reliable means for setting /-==0.

The present invention has been made based on the above-mentioned recognition, and therefore, according to the present invention, as shown in FIG. A loop 2' is formed on the engagement side of the upper and lower vinyl rolls 5 and 4 so that the hot strip 2 and the lower vinyl roll 4 are substantially in point contact.

An embodiment P is shown in FIG. 4 in which a loop 2' is formed in front of the biting part of the upper and lower pinch rolls 5 and 4 of the winding machine. For example, a small inertia with small inertia (for example, straight ("f-
An idle roller 9 of 100 to 200 mm is rotatably supported on the upper end of the piston rod 1 of a vertical cylinder device 10, and normally the cylinder device 10 is reduced and the idle roller 9 is connected to the table roller 3 and the lower pinch roll 4. Move it back to the position shown by the imaginary line so that the top end is lower than the top end.

Appropriate load for the final stand of finishing rolling mill 1.

When the cell is installed and the tail end of the hot strip 2 is pulled out of the finishing rolling machine, the driving device 12E of the hydraulic cylinder device 1o is driven +ff+ by the signal A from the load cell to extend the cylinder device 1o. The idle roller 9 is raised to a position where its upper end is in contact with the tangent line between the lower vinyl roll 4 and the deflector roller 6 (as shown by the solid line), and the idle roller 9 is raised to the position where the upper end is in contact with the tangent line between the lower vinyl roller 4 and the deflector roller 6, and the upper and lower vinyl rollers 5 are placed on the biting side of the upper and lower vinyl rollers 5.
Whelk 2. is lifted to form a loop 2'E, thereby making the wrapping angle of the hot strip 2 around the lower pinch roll 4 approximately zero.

The method of forming the loop 2' is not limited to the above-mentioned method, but can be performed in any other way, for example, usually by slowing down the circumferential speed of the table roller 3 with respect to the hot strip. However, by synchronizing the hot strip lip and the circumferential speed of the hot running table roller, a loop can also be formed by the bending of the hot strip.

According to the present invention, after the tail end of the hot strip exits the final stand for finish rolling, the loop plane 1 of the hot strip is placed on the pinch roll biting side so that the wrapping angle of the hot strip with respect to the pinch roll becomes small. This method can prevent pinch roll slip flaws that occur when slipping with a pinch roll hot strip, and can be particularly advantageously applied to rolling stainless steel, which requires a beautiful surface that is free from surface flaws.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing the line arrangement after the finish rolling machine of a hot mill. Figure 2 is a schematic diagram showing how the hot mill is wound around the lower pinch roll in a conventional hot mill winder. A loop is formed in the cut strip. It is a schematic diagram showing the state. 1... Finishing rolling mill, 2... Hot strip, 3...
...Hot run table roller, 4... Winding machine bending upper pinch roll, 5... Winding machine bending lower pinch roll, 6... Winding machine deflector roller, 7
... Winding machine mandrel, 8... Coil, 9... Idle roller, 10... Hydraulic cylinder equipment Jff, it
...Piston rod. Patent applicant: Kawasaki Steel Corporation No. 2 [τ1 No. 3 f'4

Claims (1)

[Claims] L In the method of winding the hot strip fed from the finishing mill of a hot strip mill onto the table roller through the bending pinch roll and deflector roller of the winding machine and onto the winding machine mandrel, the tail end of the hot strip is finished. After the final stand of the rolling mill is unloaded, a loop of the hot strip is formed on the biting side of the pinch rule to reduce the wrapping angle of the hot strip with respect to the pinch roll. How to take it.