SU715155A1 - Roll for cold tube-rolling - Google Patents

Description

one

The invention relates to pipe production and relates to the use of a working tool, in particular work rolls for cold periodic shyukatha pipes.

A work roll for periodically cold rolling of tubes is known, having a barrel with an outer surface and located there along a helix stream of variable cross section along a length of 1J.

In these, the radius of curvature of the outer surface of the barrel is constant, while Yrem as the depth of the creek is tribal. As a consequence, the roll radius, i.e. the distance from the axis of rotation of the roll in relative motion to its instantaneous center of rolling; in rolls with the cylindrical outer surface of the barrel, the value is variable, equal to the constant radius of the drive gear of the roll drive;

NI drive rolls, leads to the appearance of a significant axial force acting on the workpiece and directed along the pipe. Axial forces can lead to loss of stability of the workpiece and the rod, breakdown of the pipe from the mandrel during the production process, which worsens the quality of the finished pipe, reduces the service life of gauges, and causes breaks in the working stand.

The closest technical design to the vacuum is a cold-rolling roll containing a barrel with a conical surface open below the surface.

S on it along a spiral line of a stream of variable cross-section along the length and with a large cross-section of a stream at a large base of the cone

AND.

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In the process of your work, your unit accomplishes with the cage a non-continuous u) expansion relative to the axis of the next. In this case, the taper of the roll barrel is determined

the gear ratio of the corner speeds of the stand of the cage and the roll, and is chosen such that the tops of the rolling cones representing the locus of the points of the centers of rotation of the caliber are on the axis of rotation of the cage and the axis of the stream on its development is linear. Such an embodiment of the taper and location in a known roll does not make it possible to increase the reduction of the diameter of the workpiece when it is deformed by the reciprocally movable and rotating rollers, since there is no correspondence of the rolling radius to the radius of the drive pin driver, which increases the axial forces acting on the workpiece.

The purpose of the invention is an increase in the degree of reduction of the workpiece during the reciprocating shifting of the rolls,

To achieve this goal, in the work roll for cold pro-psi, which contains a barrel with a conical outer surface and a stream of variable cross section along a helix along the length with placement at the larger base of the cone with the largest cross section, the stream is the smallest the base of the cone of the barrel, the angle at which the top is equal to

.- (a -0y-5.sh1,, (O-, d 4S.

where (7.) 2,) ep is the mean difference of the diameter of the roses of the billet and the finished pipe;

n is the number of turns of the stream; t - helix pitch. These differences allow the forced rolling radius to be closer to the ideal, as a result of which the axial forces on the workpiece will be as low as 1 J, the length of the rolls, which will allow you to reduce the diameter of the pipe billet during deformation.

Fig 1 is a roll, general view; in fig. 2 - the position of the stream roll relative to the workpiece.

The work roll contains a barrel 1 and a neck 2. The barrel has a tapered outer surface on which a stream 3 of variable cross section along the length is located along a screw line.

When rolling the work roll, rolling over a stream 3 of variable cross section along the work cone 4 of the workpiece, makes a complex movement: translational with speed V in the direction of movement of the working stand and rotational around the axis of the roll with an angular

speed (A5g,

Due to the conical outer surface of the roll barrel and SHHTcsoro pSci. the position of the brook on it, the radius R a of the curvature of the outer surface of the roll barrel in the area of contact of the working cone with the brook and the depth m of the barrel are reduced when the gauge moves from the billet to the finished tr. 5, , 8) varies little along the length of the arc of the stand, approaching the constant radius of the initial circumference of the drive gear drive of the work roll rolling along the stationary toothed rack (not shown).

The use of calibers of the proposed construction allows reducing the axial force acting during rolling along the rolled pipe and increasing the diameter of the workpiece during rolling. In addition, in the mills with the rolls offered, there is no need to install curvilinear gear-shaped gears that are very difficult to manufacture and insensitive to manufacturing and assembly.

Claims (2)

1. Author's testimony of the USSR No. 366900, cl. B 21 B 21/02, 1971. 2. USSR author's certificate No. 293400, cl. B 21 B 21/00, 1969.