JPS60210303A - Rolling method - Google Patents

Abstract

PURPOSE:To maintain an excellent sheet shape throughout the whole length of a coil by adjusting a ratio of different speeds so that a rolling force is constant even when the speed of a rolling sheet is changed during the time till the tail end of the sheet fed to a mill runs out therefrom. CONSTITUTION:During the time till the tail end of a rolling material unwound from a coil runs out of a mill after passing through the mill, the rolling is performed in a state of enhancing the ratio of different speeds of rolling mill so that a rolling force is constant at the initial and final stages of rolling. Thus, an excellent sheet shape is maintained throughout the whole length of coil.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rolling method that allows a good plate shape to be obtained over the entire length of a coil.

[Prior art]

In general, the speed pattern from threading through to tail-off when unwinding and rolling one metal sheet coil is as shown in FIG. On the other hand, as shown in FIG. 2, there is a relationship in which the rolling friction coefficient and the rolling force change depending on the rolling speed. In other words, during normal rolling work ('), from the initial stage of rolling near the starting end of the coil to steady rolling, the rolling speed is
2, and from the time of steady rolling to the final stage of rolling near the end of the coil, the rolling speed is decelerated from v2 to ■, so this acceleration and deceleration n-q hs rolling friction coefficient and rolling force Therefore, there is a problem that the deflection curve of the rolling roll changes between acceleration and deceleration and steady rolling, and the shape of the sheet JI6 also changes.

Therefore, in the past, operations such as detecting the shape of the plate and changing the pending force based on it were carried out, but these operations were extremely difficult (two-sided example) and caused problems such as response delays, etc. There was a problem.

[Purpose of the invention]

The present invention aims at (1) keeping the rolling force constant even when the speed changes, and eliminating changes in the shape of the plate during the process from passing through the plate to finishing the plate.

[Structure of the invention]

The rolling method of the present invention involves rolling one sheet coil in a rolling machine (during the period of rolling two sheets until the end of the sheet rolls out) (2. By appropriately adjusting the different speed ratio, the rolling force is rolled at a substantially constant state. It is characterized by:

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

As shown in FIG. 3, in the rolling method of the present invention, the speed between speeds (1) and (2) in FIG. During acceleration and during deceleration between speed ■2 and V, that is,
At the initial stage of rolling and at the final stage of rolling, rolling is performed with the true speed ratio of the rolls being increased so that the rolling force remains constant.

Generally, as shown in FIG. 4, a variable speed rolling mill has a characteristic that the higher the true speed ratio, the lower the rolling force. Therefore, in the present invention, the true speed ratio is increased during acceleration and deceleration, as shown by the solid line in FIG.

In this way, as shown by the solid line in Figure 3 (b),
The rolling load during acceleration and deceleration can be made the same as during steady rolling, that is, constant (including approximately constant) (see conventional dashed-dotted line).

As mentioned above, when the rolling force is kept constant, as is clear from FIG. 2, there is no change in the deflection of the rolling rolls due to changes in speed, and the plate shape is well maintained over the entire length of the coil.

It should be noted that the present invention is not limited only to the above-mentioned embodiments, and for example, the present invention also includes a case where the steady rolling time is the true speed, as shown by the two-dot chain line in FIG. Of course, various changes other than 7C can be made without departing from the gist of the present invention.

[Effects of the Invention] As explained above, according to the rolling method of the present invention, (11) the true speed ratio is adjusted so that the rolling force is constant, so that the plate shape is well maintained over the entire length of the coil. be done.

(ii) It is not necessary to adjust a shape modification device such as a bending device for shape modification, and the range of use of the shape modification device can be expanded. That is, it is possible to omit the amount of the shape correction device that should be maintained for the variation of the rolling force.

(iii) The amount of variation in edge drops can be reduced.

It can produce excellent effects such as

[Brief explanation of the drawing]

Figure 1 is a diagram showing the speed pattern from passing through to end of strip when rolling one plate coil, Figure 2 is a diagram showing the relationship between rolling speed, rolling friction coefficient, and rolling force, and Figure 3 is a diagram showing the relationship between rolling speed, rolling friction coefficient, and rolling force. A process diagram showing the rolling method of the present invention, in which A) shows the relationship between the true speed ratio and time, and (B) shows the relationship between rollability single layer and time,
FIG. 4 is a diagram showing the relationship between true speed ratio and rolling force. Patent applicant's agent Makoto Otsuka Zomaki

Claims (1)

[Claims] 1) A rolling method characterized by rolling a plate coil at a substantially constant rolling force by adjusting an appropriate speed ratio between the time the plate coil is passed through a rolling mill and the time when the coil is rolled.