SU995971A1 - Method of restoring geometry of upper roll of finishing stand - Google Patents

Description

(5) METHOD OF RESTORING GEOMETRY OF UPPER PURPOSE CLEAN ROLL

one

The invention relates to the production of curved rolled sections.

There is a known method of restoring the geometry of the upper rolls of the finishing rolls of the bending mills by removing the machining of a part of the metal from the horizontal portion of the upper roll 1.

The disadvantage of this method is the labor costs for handling rolls and mill downtime. . .

The purpose of the invention is to reduce labor costs and reduce downtime of the mill.

This goal is achieved by the fact that according to the method of restoring the geometry of the upper roll of the finishing stand of a roll forming mill for forming profiles from hot rolled non-etched blanks, mainly of the channel type, by removing part of the metal from the horizontal portion of the upper roll,

In the course of forming the profiles, the circumferential speed of the roller being restored relative to the moldable profile is reduced.

At the same time, the reduction in the peripheral speed of the upper roll relative to the moldable profile is 10-15% lower,

FIG. 1 shows the character of the nose of the upper roll in the process of forming the profiles in FIG. 2 - restoration of the roll geometry.

For example, mm bent channel made of steel 3 kp receive a bending profile element from 6 to 90. The crushing is carried out on a continuous profile of a bending mill with a common drive according to the mode of bending of the shelves in 8 cells x:

.90

20

In all the cells, except the last one, the speeds of the rolls are equal along the bottom of the gauge with the speed of movement of the forming strip.

With pilot rolling on mill 1 50-300, the rolling diameter of the upper rolls of 1-7 stands equals, and the lower rolls of all stands are 185 mm, the gear ratio of the gear stand of the mill is 2.515. The circumferential speed determined by the rotation of the rolls and their diameters, the upper rolls 1-7 of the stands, all the lower rolls and the speed of movement of the strip is 1.95 m / s. The rolling diameter of the upper roll 8 (the last) of the mill stand is 405 mm and its circumferential speed is 1.75 m / s, i.e. this speed is less than the speed of movement of the profiled strip by 12-13%.

After the pilot rolling of 1200 t of the channel, the radii of curvature rnpactically remain equal to the original radii of mm, which makes it possible to continue rolling on these rolls without degrading the quality of the profiles produced.

A decrease in the peripheral speed of the roll relative to the moldable billet by 5–8% does not give the desired effect, and increasing this difference to leads to the heating of the roll and injury to the surface of the workpiece.

The economic effect is obtained by increasing the duration of the contact of the rolls and reducing the downtime of the mill due to transshipments.

Claims (2)

1. A method for restoring the geometry of the upper roll of the finishing stand of a roll forming mill for forming profiles from hot rolled non-pickled blanks, mainly of the channel type, by removing a part of the metal from the horizontal portion of this roll, characterized in that In order to reduce labor costs and reduce mill downtime by reducing the number of transshipments, removal of part. the metal from the horizontal portion of the upper roll is carried out in the process of forming profiles by reducing the circumferential speed of the roll to be restored relative to the moldable profile. 2. The method according to claim 1, excluding the fact that the reduction in the peripheral speed of the upper roll is relatively formable. the profile is performed by 10-15%. Sources of information taken into account in the examination 1. Kaluzhsky VB, Chekmarev A.P. Bent rolling profiles. M., Metallurgists, 197, p. (prototype).