SU1251988A1 - Method of cross-rolling and mill for effecting same - Google Patents

Abstract

1, The method of cross-helical rolling, including from one heating a firmware into a sleeve of a solid billet by three drive rolls on a short mandrel and rolling of a sleeve on a pilindrical mandrel connected to a short mandrel with a common rod, about a liter. due to the fact that, in order to obtain profiled products with sharp transitions and large diameter differences in transitions, the liner begins rolling after its exit from the rollers performing the piercing, on the mandrel moved along the rolling, which is driven by a drive with a speed equal to 1 , 0 - .1,2 speeds of the product, with the profiling of the outer surface by moving rollers and with the application of axial tension. 2. A helical rolling mill containing a working stand with three drive forming rolls, a mechanism for moving the rolls during the rolling process, a tension device for the product and a mandrel, so as to enhance the technological capabilities by ensuring the production of profiled products with abrupt transitions and large differences in diameters at the transition sites, it is equipped with three additional piercing rollers rigidly mounted at intervals from the main rollers on the same shafts, and stubborn fur a rod carrying the mandrel with a drive for its axial movement located on the tension device for the product. YO 01 from 00 oo

Description

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The invention relates to the processing of metals by pressure, in particular to hot-rolled rolling, and can be used for the production of hollow round shaped articles such as crankcase housings of automobiles, drill pipe nipples and other mechanical components.

The purpose of the invention is to obtain specialized products with sharp transitions and large differences in diameters at the points of transition, as well as expansion of technological capabilities by ensuring the production of specialized products with sharp transitions and large differences in diameters at the points of transition.

The method of cross-helical rolling consists in piercing a heated solid billet with three drive rolls on a short mandrel and rolling out the outgoing sleeve on a cylindrical mandrel connected to a short common rod and moved along the drive with a speed equal to 1.0-1.2 speeds product, with the profiling of the outer surface of the moving rollers and with the application of axial tension.

FIG. 1 shows a helical rolling mill, plan view; in fig. 2 shows section A-A in FIG. 1, an operation for flashing a sleeve, FIG. 3 the same 5 profile rolling operations.

The helical rolling mill contains a working stand 1 with profiling rollers 2 mounted on 3 with their 4 rotational drive and movement mechanism in the process of rolling in the form of hydraulic cylinders 5 with a copying device, with piercing rollers 6 fixed on the same shafts with an interval from the profiling; a thrust mechanism 7 carrying an arbor rod 8 with a short mandrel 9 and a cylindrical mandrel 10, a tensioning device 11 for. a product with a chuck 12, inside which a cylindrical mandrel is missed, with its hydraulic actuator 13, mounted on a tension device, a axial displacement drive of a thrust mechanism in the form of hydraulic cylinders 14, located in front of the cage receiving trough 15, wiring 16 and pusher 17 with a hollow bushing 18.

The helical rolling mill to produce hollow section products works as follows.

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The prepared and machined workpiece is transferred to the receiving chute 13 and the pusher 17 through the centering wiring 16 is set into piercing shafts 6, turned at the feed angle and rotated by the drive 4. The piercer rolls grip the workpiece and pierce it on a short mandrel 9 mounted on a mandrel bar eight.

10 During piercing, the workpiece is centered with wiring 16. After flashing, the pusher 17 stops and the mandrel rod 8 with a short guide 9 and a cylindrical mandrel 10

15 are displaced by moving the cylinders 14 of the thrust mechanism 7 towards the entrance of the workpiece to the piercing rolls 6 and the cylindrical reference 10 centners (; is threaded by a hollow sleeve 18. Then the sleeve

20, the pusher 17 is driven into rolls for profile rolling. Profiles rolls 2 are made with a taper angle of 25 - 35 °. Rolling the front end of the product in the profiling rollers 2 is carried out with the compressive force created by the pusher 17. At the exit of the rollers, the front end is gripped by the chuck 12 of the tensioning device 11, which by the hydraulic actuator 13 begins to move from the working stand, and tension.

At the same time, an additional axial force is created by the mandrel bar 8, displacing it with the cylindrical mandrel 10 by moving the hydraulic cylinders 14 of the thrust mechanism 7 relative to the product towards the exit of the metal from the rolls with a speed equal to 1.0 - 1.2 speeds of the product.

 Dependence V, (1,0 - 1,2) CSD is established from the following considerations.

During profile rolling, due to the lag of the mandrel, as a result of the frictional forces between the mandrel and the metal, axial flow of the metal is contained. Additional axial tension at a ratio is achieved by eliminating the lag of the mandrel and the desaturation of the directional flow of the metal towards the exit of the metal from the rolls.

When V, V, the mandrel at the expense of friction forces carries the contact shots

55 metal.pa and additional axial tension increases, with an increase in the speed of the mandrel V 1, due to a decrease in the coefficient of friction

45

50

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between the metal and the mandrel additional axial force does not increase.

The rolls are moved during rolling by hydraulic cylinders 5.5.

Performing the operations of piercing and profile rolling discretely in two groups of rolls makes it possible to carry out profile rolling with rolls with a taper angle of 1-25-35 ° and thereby obtain products with sharp transitions and large differences in diameters at the points of transitions, which expands the technological - logical possibilities of the process. Independence in time of performing 5 operations of the firmware and profile rolling is achieved by installing piercing rolls with an interval of several pains 884.

Haim length of the liner or its profiled part of the profiling rolls on the same shafts. When rolling with abrupt transitions and significant thinning of the wall of the hollow product, an increase in the axial tension can be obtained due to the additional axial force that creates, and a stop mechanism with a mandrel specially installed by the drive located on the tension device. product, with a speed equal to 1.00-1.2, the product speed, while additional axial force occurs in the deformation zone due to friction forces, is transmitted to the metal through the mandrel and does not affect the compressed areas are rolled woo product.

FIG. one

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Composition and el LL-1 and t urine Editor E. Papp Tehred E, Chshar Proofreader A. Tsko

Order 4562/9 Circulation 518 Subscription VNIIPI Gosudarstvennogo ko chiyeta USSR

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, Projecto st., 4

Claims (2)

1, Method of cross-helical rolling, including from one heating the firmware into the sleeve of a solid billet by three drive rolls on a short mandrel and rolling of the sleeve on a cylindrical mandrel connected to a short mandrel with a common rod, characterized in that transitions and large differences in diameters at the transitions, begin rolling the liner after it leaves the rollers performing the piercing, on the mandrel moved during the rolling, which is driven by a drive speed equal to 1.0-1.2 of the product speed, with the outer surface being profiled by the rollers being moved and with the application of axial tension. 2. A helical rolling mill containing a working stand with three drive forming rolls, a mechanism for moving the rolls during the rolling process, a tensioning device for the product and a mandrel, characterized in that, in order to expand technological capabilities by ensuring the production of shaped products with sharp transitions and large differences in diameters at the points of transition, it is equipped with three additional piercing rolls, fixed with an interval from the profiling rolls on the same shafts, and a stop mechanism with rod bearing the mandrel, with a drive of its axial movement, located on the tension device for the product. SC "1251988 eleven