RU58959U1 - SPACE-CLOSED CALIBER LATHES OF LONGITUDINAL ROLLING - Google Patents

Abstract

The utility model relates to the processing of metals by pressure, namely, rolling equipment and can be used in rolling pipes and sections, mainly with an increased degree of single crimping - up to 40 ÷ 60%, with a drawing ratio of more than two.

The spatially closed gauge of a longitudinal rolling mill includes its rolls with a working surface and flanges. The gauge is formed by the working surfaces of two rolls and the flat surfaces of the flanges of one of the rolls, while the flanges are elongated, the radius of which is selected from the expression:

,

Where ,

L _p - the amount of overlap caliber, mm;

R _i is the radius of the roll at large reductions, selected from the condition α <22-24 °, mm; α is the angle of capture of the workpiece rolls, deg .;

H - the height of the workpiece, mm; H≥1.75 ÷ 2.5 d ₁ ;

d ₁ is the diameter of the caliber, mm.

The utility model is aimed at simplifying the manufacture and installation of the tool to ensure complete closure of the caliber. 2 ill.

Description

The utility model relates to the processing of metals by pressure, namely, rolling equipment and can be used in rolling pipes and sections, mainly with an increased degree of single crimping - up to 40 ÷ 60%, with a drawing ratio of more than two.

Known working stand of the longitudinal rolling mill, in which the closed gauge is formed by two rolls and rulers installed in the connectors between the rolls (AS USSR No. 835539, 21 V 17/04, publ. 07.06.19981).

The stand drawback is that the deformable sleeve slides along the working surfaces of the fixed rulers, as a result of which the rulers quickly wear out, the surface quality of the pipes deteriorates, and additional friction power is expended.

Known roller tool for metal forming, in which the contact surfaces are made in the form of conjugated concave and convex spherical surfaces, the centers of which are located on the axis of rotation of the rollers, and the axis of rotation of each of them passes through the center of the convex contact surface of the adjacent roller with which this roller is mated its concave surface (AS USSR No. 499913, 21 C 3/08, publ. 01.25.1976).

The disadvantage of this device is that the rollers are difficult to manufacture and complicated their assembly in the cage.

Known closed gauge formed by rolls with convex and concave adjoining surfaces (Kostogryzov I.D., Filatova I.A. Kleti for metal forming. Ed. UPI, Sverdlovsk, 1980, p.10).

The disadvantage of this caliber is that it has a complex contour geometry in the output section formed by rolls with unequal “ideal” diameters.

The closest technical solution adopted for the prototype is a multi-roll caliber rolling mill, formed by two rolls with intersecting axes, in the connectors between which are mounted profile disks in contact with the rolls on spherical surfaces (RF patent No. 919217, 21 V 13/10, publ. . 05.20.1996).

The disadvantage of this caliber is the complexity of manufacturing the contacting spherical surfaces of the rolls, as well as the complexity of their assembly.

The technical problem solved by the utility model is to simplify the manufacture and installation of the tool to ensure complete closure of the caliber.

The problem is solved due to the fact that in a spatially closed caliber of a longitudinal rolling mill, including the rolls forming it with a working surface and flanges, according to a utility model, the caliber is formed by the working surfaces of two rolls and flat surfaces of the flanges of one of the rolls, while the flanges are made elongated whose radius is selected from the expression:

,

Where ,

L _p - the amount of overlap caliber, mm;

R _i is the radius of the roll at large reductions, selected from the condition α <22-24 °, mm; α is the angle of capture of the workpiece rolls, deg .;

H - the height of the workpiece, mm; H≥1.75 ÷ 2.5 d ₁ ;

d ₁ is the diameter of the caliber, mm.

The utility model is illustrated by drawings, where figure 1 schematically shows the proposed space-closed caliber, figure 2 shows the deformation zone of the space-closed two-roll caliber.

Space-closed caliber (figure 1) is formed by the working surfaces of the rolls 1 and the flat surfaces of the flanges 2 of one of the rolls, while the flanges are made elongated.

The work of the caliber is as follows. The dependence for determining the radius of the flange of the roll is established from the following premises. The gauge will be spatially closed if the workpiece with a height H touches the working surface of the caliber at a distance less than the overlap of the caliber L _p (figure 2). The size of the overlap of the caliber L _p can be determined with a known final rental size d ₁ and the height of the workpiece N. From the geometric relationships it follows that

Knowing the value of L _p , we find the value of the radius on the flange

Full closure of the caliber, i.e. closing the deformation zone from the moment the workpiece is captured by the rolls until it is completely rolled is achieved when one of the rolls is flanged with elongated ones, the radius of which is selected from expression (2).

To ensure the natural capture of the workpiece by the rolls at large reductions, it is necessary to choose the radius of the rolls R _i so that the capture angle at a certain value of H does not exceed 22 ÷ 24 °. The determination of the value of R _b according to the formula (2) guarantees the absence of gaps between the rolls when rolling a rectangular billet with the original

height H at the time of capture of the workpiece by rolls of caliber, which ensures intensive metal flow in the longitudinal direction and the achievement of high deformation indicators.

The proposed caliber is easy to manufacture and install the tool and, in addition, has an increased energy capability, which is ensured by a larger contact area of the workpiece metal with the rolls.

Example. At mill 10-76, rolling and flashing of pipes of size 15.0 × 0.5 mm from a rectangular lead blank of size 36.0 × 14.0 mm was carried out. To ensure the rolling process in a spatially closed gauge, the radius of the roll was calculated according to the flanges R _b , which closed the deformation zone. Initial data: caliber size d ₁ = 15 mm, workpiece size at the apex N = 36 mm, roll radius at large reductions R _i = 150 mm, selected from the condition α <22-24 °.

Based on the formula , the angle of capture of the workpiece rolls is 22 °, which provides a natural grip. Using the formula (2), we determine the value of R _b . For the adopted source data (d ₁ , H, R _i ) received R _b = 182 mm The firmware-rolling process was performed at a roll speed of 82 rpm.

Rectangular lead blanks with a cross-sectional size of 36.0 × 14.0 mm were installed in guides on the input side of the deformation zone. A mandrel with a diameter of 14.0 mm was mounted on the rod. The workpiece along the guides was set into rolls with the proposed spatially closed gauge, which excluded the flow of metal into the outlets from the moment it was captured by the rolls to the exit from the deformation zone. The firmware-rolling process proceeded stably and was carried out with an extraction coefficient λ = 20. Self-centering of the mandrel in the deformation zone was noted. When longitudinal rolling using existing gauges, it is impossible to obtain a workpiece hood in

2–3 times, since with large reductions in the workpiece, the metal flows intensively into the outlets, and in the proposed caliber, the outlets are closed with elongated flanges.

Using the proposed caliber will simplify its manufacture and installation, increase one-time deformation of the workpiece during rolling and during firmware-rolling. And it will also allow you to get the finished pipe in one pass from a cast or hollow steel billet, which will lead to a reduction in metal consumption by about 10-15% and increase productivity.

Claims (1)

A spatially closed gauge of a longitudinal rolling mill, including the rolls forming it with a working surface and flanges, characterized in that the caliber is formed by the working surfaces of two rolls and the flat surfaces of the flanges of one of the rolls, the flanges being elongated, the radius of which is selected from the expression

Where

L _p - the amount of overlap caliber, mm; R _i is the radius of the roll at large reductions, selected from the condition α <22-24 °, mm; α is the angle of capture of the workpiece rolls, deg; H - the height of the workpiece, mm; H≥1.75 ÷ 2.5d ₁ ; d ₁ is the diameter of the caliber.