SU1258531A1 - Composite hump roll for three-high rolling mill - Google Patents

Description

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The invention relates to the production of hot-rolled pipes on helical rolling mills, and more specifically to the design of the rolls of a three-roll roll mill.

The purpose of the invention is to reduce the fleet of working tools.

FIG. 1 shows the proposed roll, a general view; in fig. 2 - the same, with a gap in the melody parts of the barrel.

The roller contains a drive axle 1 and a barrel, E (from part 2 of a smaller cross section with a ridge 3, the top of which is separated from the rear end 4. At a distance of 0.01-0.0144 of the barrel diameter at the apex of rpei6i; n (Dv), and which is rigidly fixed on the axis, and part 5 of a larger cross-section, which is biased; it is fixed with a pin 6, located in an annular groove, and has an axial movement mechanism in the form of a sleeve 7, through a bearing 8 acting on the movable part barrels, two shoulders lever 9 and 3 idrocylinder 10, mounted on the frame.

The process of rolling thin-walled tubes on a three-roll mill using composite rolls is carried out in the following manner.

The floor of the sleeve is rolled into a tube on a cylindrical mandrel. When the main part of the pipe is crushed, parts 2 and 5 of the composite roll are in the initial polission, i.e. in contact with the SURFACE 1-1 subzerphals, forming a single contact surface with the pipe (Fig. 1). At the same time, the movable part 5 of the roll barrel is prevented from moving along the drive axle 1 by means of a cylindrical sleeve 7 mounted on the drive axle and connected via two shoulders lever 9 to the hydraulic cylinder 10 mounted on the frame of a three-roll mill. Prukhsin 6 is in a compressed state. At the moment of the beginning of the contact of the back end of the pipe with the rollers, i.e. when rolling the rear end of the pipe, the cylinder rod rotates, turning the double-arm lever, moves the sleeve along the rollers along the drive axis (Fig. 2). The movable part of the roll barrel by the action of trenp forces acting on the contact surface of the roll with the tube.

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and the springs move along the drive axis in the direction of the rolling course. At the same time, between the parts of the head there is a gap equal to 0.010–0.015 di

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The roll meter and the end of the rolling process are carried out with the roll parts displaced relative to each other. After the pipe deformation process is completed, the hydraulic cylinder, turning the lever, moves the sleeve along the drive axis and, compressing the spring, returns the movable part of the roll barrel to its initial position, i.e. until it touches the other end of the barrel. The next pipe is rolled in the same sequence, similar to the proposed method.

The process of rolling thick-walled pipes on a three-roll mill takes place without displacement of parts of the roll barrel of the designed structure (Fig. 1). In this case, during the entire process of deformation of the pipe, parts of the roll barrel contact the face surfaces with each other.

The design of the composite roll of a three-roll mill makes it possible to create a continuous or discrete along the length of the deformation center during rolling, respectively, of thick or thin-walled tubes. The displacement of one part of the roll relative to the other allows to divide the deformation zone along the length into two deformation zones, which helps to reduce the ovalization of the profile of the rolled-up tubes. In connection with this, conditions are created for the deformation of thin-walled pipes () without formation of defects in the form of masts on their end sections. Dilution of the roll barrel portions may be accomplished by rolling the back end of a thin-walled tube, where the socket is most likely to form, or alternatively, by rolling the entire tube from beginning to end.

The rolling of thick-walled pipes (D / S 8) is carried out with the barrel parts connected to one another. In this case, a continuous deflection core is created, which contributes to the increase in the ovalization profile of the pipe and the improvement of the conditions for the extraction of the mandrel.

The selection of the amount of displacement of one roll portion 604Kii relative to another and the location of their connector is based on the following.

On the roll section of the rolls, following the ridge in the course of rolling. the pipe is maximally compressed in wall thickness and diameter. In this area, the socket is most likely to form a socket at the ends of thin-walled pipes. Therefore the dismemberment

The contact surface at this location allows to reduce the size of the ovalization profile of the pipe to the maximum extent. Moreover, the plane of the clock connector of the roll barrel should be 5 at a rn shnimnally possible distance from the top of the ridge, since at the beginning of the ascate section the value of private pipe collapses reaches a maximum. When rolling lead pipes of size 25.2x2.4 mm on a laboratory three-roll mill using composite rolls, it was determined that the optimum distance between the parts of the roll barrel and the t5 base of the ridge is 1.0 -1.4 mm.

Reducing this value leads to the formation of cuts on the outer surface of the pipes, and an increase of more than 1.4 mm results, due to the displacement of the plane of the connector of parts of the roll barrel to small values of partial reductions, to a decrease in the rolling speed by 12-18% due to a decrease in the maximum possible under the conditions of the formation of the 25 sockets of the angle of feed of the rolls by 0.5-1.0%. Since the diameter of the pilot rolls on the top of the ridge is 100 mm, the distance of the plane of the connector of the barrel parts from the top of the ridge is equal to 0.010-0.0144 of the roll diameter.

The optimum value of the displacement of one part of the roll barrel relative to the other according to experimental data is 1.0-1.5 mm. When reducing the amount of displacement of a roll barrel less than 1.0 mm when rolling thin-walled tubes, the maximum possible feed angle Q of rolls decreases by 1-1.5 and the rolling speed decreases accordingly (up to 30%), since the contact surface of the metal with rolls remains virtually uninterrupted (without free-form pipe profile zones). An increase in the displacement of the movable part of the roll barrel of more than 1.5 mm leads to the leakage of the metal of the pipe into the gap between the parts of the roll barrel, cuts on the outer surface of the pipes and a decrease in the rolling speed by 20-25%. Thus, the optimum amount of displacement of the movable part of the barrel of a composite roll with a diameter of 100 mm is 0.010-0.015 of its diameter along the top of the ridge.

The principle of moving the movable part of the barrel rolls of the developed design relatively stationary is based on the following. - When rolling the rear end of a thick-walled tube, the movable part of the roll barrel, under the influence of friction forces on the contact surface of the deformable metal with the roll, moves along the axis of the roll by a predetermined amount. For a guaranteed value and speed of movement of the movable part of the barrel, the design of the roll provides for a helical spring mounted on the drive axis and installed in an annular groove made on the inner surface of the movable part from the plane of the connector. The width of the annular groove should be sufficient to place the spring in it in a compressed state and to effect a specified movement of the movable part of the roll barrel when the spring is opened. One end of the spring rests in a collar on the drive axis of the roll, fixing the position of the fixed part of the barrel in the axial direction, and the other in the end of the annular groove of the movable part.

The composite rolls of the proposed design can be used for stitching workpieces, rolling or rolling a wide assortment of pipes on three- and two-roll mills and reduce tool fleet by half.

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Editor O. Golovach

Compiled by L. Maturin

Tehred A. Kravchuk Proofreader S. Shekmar

Order 5061/10 Circulation 518 Subscription

VNIISHI State Committee of the USSR

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d. A / 5

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Production and Printing Enterprise, Uzhgorod, st. Project 1, 4

FIG. 2

Claims (1)

COMPOSITE CREWING SHAFT OF A THREE-SWAG MILL, comprising a drive axle and a barrel, consisting of a part with a larger cross section arranged with an ridge and arranged behind it with an annular gap, and one part is rigidly fixed on the axis and the other is mounted with the possibility of axial movement, characterized in that, with In order to reduce the tool fleet, it is equipped with an axial movement mechanism for a part of a larger cross section, which is spring loaded relative to a part of a barrel of a smaller cross section fixed with a rigid axis with a comb -being vertices from the rear end of the barrel portion of the barrel diameter 0,0100,014 on top greb- § FIG. I I