SU1537336A1 - Method of step rolling - Google Patents

Abstract

The invention relates to rolling production and can be used in the preparation of blanks with large draws per pass. The purpose of the invention is to increase productivity by increasing the feed rate and simplifying the roll manufacturing technology. The blank 2 is rolled in a single pass from a square with a side H _o to a circle. There are two sections on the rolls - crimping and calibrating. The compression section leads to the compression of the workpiece on the cone of deformation, and the finished circle is calibrated. Compressing the workpiece on the deformation cone with a smooth barrel allows an increase in the degree of deformation. This in turn allows an increase in feed. 6 Il.

Description

3153

The invention relates to rolling production and can be used in the preparation of blanks with large draws per pass.

The aim of the invention is to increase productivity by increasing the feed and simplifying the manufacturing techniques of the rolls.

FIG. 1 shows the initial position of the rolls; in fig. 2 - the position of the rolls during the rolling of the billet on the deformation cone; in Fig, 3 - the position of the rolls during rolling of the workpiece on the calibrating area; in fig. k is a section A-A in FIG. one; in fig. 5 is a section BB in FIG. 2; in fig. 6 is a sectional view BB in FIG. 3

We consider the implementation of the proposed method of step deformation using the example of rolling round strips in a four-shaft caliber.

Rolling rolls 1 make punitive movement around the 0-axis. The compression of the workpiece 2 is carried out with the formation of a deformation cone on the strip - the transition section from the original workpiece to the finished profile (Fig. 1-3). In the initial position (Fig. 1), the gap between the rolls 1 exceeds the height of the initial band H0. At this time, the workpiece with the cone rolled out in the previous step of deformation is turned over by an angle / n (with

the angle of turnoff is -g- - 5) and

moves by the feed amount t. When rolling a deformation cone in rolls with a smooth barrel, the cross section of the deformation cone has the shape of an irregular octahedron (fig.k and 5), and the distance between the sides of the octahedral deformed in the previous step is less than the distance between the sides of an octahedron G, undeformed in the previous deformation step. This is due to the fact that the profile of the cone on the sides of D is displaced along the rolling axis (Fig. 1) towards the finished profile by the feed amount.

The described deformation cone in the considered deformation step is set into rolls 1, which, turning, produce on the deformation cone its compression & h (Fig. 2), the value of which gradually decreases and reaches the minimum value in the calibrating section. Thanks to the fact that

Q 5

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between the sides D is smaller than between the sides G, the width of the working surface of the rolls with a smooth barrel is greater than the width of the workpiece when it is compressed (figure 5). This makes it possible to increase the feed rate m to a value when the diagonal of a square caliber formed by the working surfaces of the rolls is equal to the distance between the sides D of the octahedron in the corresponding cross sections of the deformation cone (Fig. 5), taking into account the broadening of the strip.

The feed rate m of the workpiece when implementing the proposed method of step rolling may be significantly greater than when rolling in rolls with lancet or round gauges.

In the calibrating area, parts of the working surface come into contact with the workpiece with strands forming round calibers. These calibers define a part of the length of the deformation cone at its end (Fig. 3), the cross section of which also has the shape of an irregular octagon (Fig.6) which is crimped to a finished round profile. Obtaining round burr-free profiles with large strip feeds is also ensured by the fact that the octahedron deformable in a round caliber has an irregular shape.

After the strip has been compressed in the calibrating area, the rolls return to their initial position (Fig. 1), the workpiece is moved by the feed amount and turned over by 5 °.

Experimental testing of the method of step rolling is carried out at the pilot mill of step rolling (rolling-forging mill). From the original blanks H0 55 mm get round profiles f 20 mm with feed m, 5 mm. Similar profiles are rolled on the same mill during the compression of the workpiece in a round caliber both at the end of the deformation and at the calibrating section. At the same time, the maximum possible feed of the strip without the formation of burrs (whiskers) on the deformation cone was m 3 mm.

Thus, the proposed method of step rolling is highly efficient, the productivity of the step rolling process by increasing

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Claims (1)

Formula invent The method of step rolling of round round profiles with several rolls of variable radius with crimp and gauge sections of the working surface, including feeding