SU1414487A1 - Method of setting up the passes of tube cold rolling mill - Google Patents

Abstract

This invention relates to pipe production. The aim of the invention is to improve the accuracy and simplify the settings. The adjustment of the gauges of the rolls 1 and 2 of the cold rolling mill tube is carried out as follows. Set the working cage to its original position. Accelerated movement of the cartridge billet 4 serves in the gauges of the rolls on the amount of feed or slightly more. The plastic element 3 is stirred motionless between the flanges of 5 gauge rolls. It is a tube with a ratio of the outer diameter to the nominal technological gap equal to 2.5 ... 4.5 and the outer diameter to wall thickness equal to (2.4 ... 4,5): (0.25 ... 0.45). The end of the tube in the short section is pre-deformed to a height slightly less than or equal to the minimum possible gap between the roll gauges. With this end, it is inserted into the gap between the flanges. Then the rollers are moved to the extreme position, and after they are stopped, a tube is removed, which is deformed between the flanges of the rolls and has a thickness of the actual technological gap between the flanges of the rolls along the length of the stand. Having determined these values in the necessary sections outside the cage with an exact measuring tool, they adjust the technological gap between the flanges of the roll gauges by the nominal size in a known manner. 2 hp f-ly, 1 ill., 1 tab. Q b (L 4 Ji 00

Description

The invention relates to pipe production, more precisely to cold rolling mills for pipes, preferably with a moving stand.

The purpose and enrichment is to improve accuracy and simplify customization.

The drawing shows the arrangement of the roll calibers in close to extreme positions.

The method of adjusting the gauges of the rolls 1 and 2 of the cold rolling mill tube is carried out in the following way.

A cylindrical plastic element 3 is preliminarily prepared, for example, a tube with a diameter of 0.5–4.5 of the nominal value of the technological gap, with a ratio of the diameter to the wall thickness (2.3, 4.5) :( 0.25 ... 0.45) and a length slightly longer than the course of the cage.

Set the working cage to its original position. With the accelerated movement of the cartridge, the blank 4 is fed into the gauges of the rolls by the amount of feed or a few bolts then. Then place the plastic element 3 fixedly between the flanges of 5 calibres, while its rear end is inserted into the gap

to

1А144ЬУ2

This type of tube, equal to (2.5 ... 4.5):: (and, 25 ... 0.43) is caused by the following. When choosing the lower limit of the ratio of the diameter of the plastic element and the size of the technological gap, the minimum compression of the plastic element and its task in calibers does not require sharpening the rear end. With a further decrease in this ratio, the plastic element may not be compressed in certain parts of its length due to the excess of the actual gap between the gauges of the rolls of the initial height of the plastic element. With an increase in the ratio to 4.5, an increase in crimping of the ductile element is achieved, but it is necessary to sharpen its rear end in order to be gripped with gauges during subsequent rolling. An increase in the Bbmie ratio of the maximum value worsens the conditions for the gripping of the plastic element with roll gauges and, with an increase in the clamping force against the gauges, may lead to the loss of stability of its straight line shape. In addition, an increase in compression of the plastic element when it is rolled between flanges

20

25

between the flanges, for which the short rolls leads to a sharp

The section is pre-deformed to a height whose value is slightly less than or equal to the minimum possible gap between the roll gauges.

The rollers are moved to the extreme position and, after they are stopped, the plastic element is removed, which is deformed between the roll flanges and, therefore, has a thickness along the length corresponding to the distance between the flanges of the roll gauges along the length of the stand.

Outside the cage to the exact measure-

telnoe tool, such as micro-45 form. When choosing the ratio by meter, the deformed plastic element is measured in the corresponding sections.

Having thus obtained information on the actual technological gap between the flanges of the roll gauges, it is adjusted to nominally the size by known methods.

The choice of the limits of the relationship between the diameter of the gshastic element and the nominal value of the technological gap equal to 2.5 ... 4.5, and the diameter and thickness of the plastic element wall

0

deterioration of its linearity, and when there is significant sickle-shapedness to its reforming in the center of the deformation of the pipe or between the details of the workstations of the cage and the bed under the working cage.

The use of a plastic element in the form of a tube improves the proposed method, since, with further reductions, the choice of the ratio of the diameter of the tube to the nominal technological gap equal to the maximum value of 4.5 reduces its deviation from the right angle.

five

The diameter of the pipe to the bottom of the wall is equal to (2.5.. .4,5) :( 0.45), an increase in the wall thickness leads to an increase in the stability of the tube shape in the task of roll gauges. A further increase in the wall thickness of the tube does not affect the proposed method of adjusting the caliber, but leads to a decrease in its internal diameter and to a deterioration in the conditions of its manufacture. Reducing the last ratio to (2.5 ... 4.5) :( 0.25) provides a decrease in metal consumption, but with a further decrease in the ratio pe: iKO, the longitudinal deviation of the tube deteriorates.

The optimum are the ratios of the outer diameter of the tube and the nominal value of a total clearance of 3.5, and the outer diameter and wall thickness of 3.5-0.35, which are average values

selected limits of ratios and 10 what, in order to increase the accuracy and

baking the best implementation of the method of setting the gauges of the rolls of the cold rolling mill tube.

Example. For the conditions of the cold rolling mill tube XJIT 90, the technological gap between the roll gauges is set to 1.0 mm. According to a known method, determining the actual gap between the flanges of calibers is produced in three positions of rolls, corresponding to the deviation of the calibers' base from the vertical plane in the front and rear positions of the working stand at an angle ui equal to AZ and 13.S and in the middle position cage - at an angle of 90. According to the proposed method, the technological gap between the gauges of the rolls is determined by measuring the thickness of the micrometer in the corresponding sections along the entire path of the rolls of the cylindrical plastic element deformed between the flanges of the gauges of the rolls. outer diameter of 3.5 mm and a wall thickness of 0.35 mm.

Testing of the known and proposed methods for determining the gap between the gauges is carried out when two calibers are installed on HPT mills intended for rolling bearing tubes of steel ShKh-15 along the route 83'9-b2, 9 mm.

The duration of determining the gap between the roll gauges is determined by a stopwatch, and the quality of the adjustment of calibers using the known and proposed methods for determining the gap is determined by the results of subsequent pipe rolling.

The results of the test are given in the table,

Claims (3)

1. The method of setting the gauges of the rolls of the cold rolling mill tube. Keying the sweeping of alcoves from the original spindle and KjiafiHee with deformation of the workpiece and them, determining the distance between the flanges of the roll gauges along the entire path of movement of the rolls and adjusting the TLC to: nominal | h and y c and and so. simplify adjustment, place a cylindrical plastic element stationary between the flanges of calibers, eject it from the rolls after the rolls stop in the extreme position, and determine the distance between the flanges of the roll gauges by measuring the thickness of the element in the corresponding ix sections, 2. A method according to claim 1, 1, O TL and H of the R - W and I with the fact that between the flanges of the rolls gauges a lumento in the form of a rod with a diameter is 2.5-1.5 times the nominal Noah of the technological gap. 3. The method according to claim 1, about tlnchu - y and, so that the element is installed in the form of a tube with a diameter of 2.3 ... i, 5 of the nominal value of the technological registry key,., and with the ratio of the diameter to the wall thickness (2.5, ..4.5): (0.25, .0.3). 35 Duration of determining the gap between calibers, min4 30 The average value of the linear displacement of the metal for rolling cycle, m 38.6 32.8 Machine time rolling one pipes, min J 3,46 4,07 Maximum deviation ng. outer diameter of the pipe, mm + 0.4 +0.5 Maximum deviation of pipe wall thickness,% +10 +12