JPH051088B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for pre-driving non-driven rolls between continuous hot strip rolling mills.

(Prior Art) Between the finishing mills of a continuous hot strip rolling line, there is a looper roll 1, as shown in FIG. 4, which adjusts mutual interference between the rolling mills due to slack or excessive tension in the strip. Alternatively, an idle roll 6 or the like is installed to support the slack of the strip. Since these rolls are auxiliary rolls that support the strip between the rolling mills, they are rotated following the reaction force of the strip, and are not driven.

Therefore, since such non-driving of the roll is a common practice, there is no prior art related to the method of providing a rotation drive device to the roll of the present invention to pre-drive the roll.

(Problems to be Solved by the Invention) In recent years, in order to reduce the load on cold rolling mills, there has been an increasing need for the production of ultra-thin strips (1.0 to 0.8 mm thick) by continuous hot rolling. Furthermore, when rolling high-grade and expensive materials such as titanium, it is necessary to take greater measures than ever to prevent strip surface defects such as scratches and seizures. In the above-mentioned situation, with the current non-driven roll, the probability and degree of the tip of the ultra-thin strip bouncing up due to collision with the roll increases, and the threading performance is extremely deteriorated.
Also, when the strip tip passes through the rolling stand and is free tensioned before being bitten by the next rolling mill,
There is a problem in that the slip between the roll and the strip causes scratches and seizures.

(Means for Solving the Problems) The present invention advantageously solves the above-mentioned problems, and its gist is that a pre-drive device is attached to the non-driving rolls between continuous hot strip rolling mills. A method for pre-driving non-driving rolls between continuous hot rolling mills is characterized in that the non-driving rolls are pre-rotated prior to passing the strip.

(Embodiment) That is, in order to solve the above-mentioned problems, it is first necessary to rotate the non-driving roll in advance. The method will be described in detail with reference to an example embodiment shown in the drawings, taking a looper roll as an example. First, a water wheel is used as a preliminary drive device for rotating the looper roll, and due to the nature of the looper, the roll drive device itself must be as lightweight as possible in order not to significantly deteriorate its responsiveness. In addition, it is preferable that the drive source be cut off at or just before the tip of the strip reaches the looper roll, and that the inertia of the roll drive device itself be as small as possible in order to easily make the peripheral speed of the looper roll follow the stripping speed. It is. Under these conditions, it is most suitable for the looper roll to be pre-driven using a water wheel.

As in the embodiment shown in FIGS. 1 and 2, a Pelton type water wheel 2 attached to the shaft end of a looper roll 1 is rotated at a circumferential speed faster than the strip speed by water jetted from a nozzle 3 attached around it. Water is supplied through a header 5 fixed to the looper 4. The timing for driving the roll and cutting off the water source is determined by a timer or a detector such as an HMD (not shown).
This is done by the signal of

(Function) For example, Fig. 3 shows the behavior when the tip of the strip 8 collides with the looper roll 1 while the looper roll 1 is pre-driven prior to the threading of the strip. It's different. In the figure, A shows a jump when the looper roll is not driven or the circumferential speed is less than the strip threading speed, B shows a jump when the strip speed and looper roll circumferential speed are equal, and C shows the strip threading speed. This is the bounce behavior when the circumferential speed of the looper roll is higher. As is clear from this, it is preferable that the circumferential speed is driven faster than the strip passing speed because of the effect of the friction coefficient upon collision, which causes the least jump. In order to achieve this object, the present invention is a method in which non-driven rolls between continuous hot rolling mills are driven in advance so as to satisfy these conditions.

(Effects of the Invention) The present invention pre-drives the non-driving rolls prior to threading the strip, thereby reducing the lift generated on the strip and effectively preventing the tip of the strip from bouncing up, which can hinder threading. In addition, compared to non-driving, the out-of-sync time with the strip threading speed is shortened, and damage such as pressure welding flaws (slipping flaws, etc.) and seizure due to this can be significantly reduced. be.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams showing embodiments of the present invention, showing an embodiment in which a Pelton type water turbine is attached to a looper roll. The figure is a schematic diagram showing the stopping behavior when the strip tip collides with the looper roll.
FIG. 4 is a diagram showing an example of non-driven rolls arranged between finishing mills. 1: Looper roll, 2: Pelton type water wheel,
3: Nozzle, 4: Looper body, 5: Header,
6: Idle roll, 7: Finishing mill, 8: Strip, 9: Looper arm.

Claims (1)

[Claims] 1. A continuous hot strip rolling mill characterized in that a pre-driving device using a water wheel as a drive source is attached to the non-driving rolls between the continuous hot strip rolling mills, and the non-driving rolls are pre-rotated prior to threading the strip. Pre-driving method for non-driving rolls.