RU2115501C1 - Axial head for rerolling small-size cylinders - Google Patents

Abstract

FIELD: machine tool building, namely tools for kinetoplastic shaping of standard surfaces of machine parts in general-purpose metal cutting machine tools. SUBSTANCE: at initial stage of working process axially fed head is moved by means of rotating blank along its axis. Two concave calibrating portions of two-roller set embrace worked cylinder for eliminating its bending and escaping out of working zone. When necessary length is achieved head is opened due to operation of opening mechanism and removed without reverse rotation. Novelty is head construction provided with two-roller set having calibration portion in the form of revolution surface whose generatrix is ellipse or circle approximating ellipse. EFFECT: possibility of working small-diameter cylinders, simplified design of apparatus due to elimination of supporting devices. 4 dwg

Description

 The invention relates to machine tool industry, in particular to tools for kinetoplastic shaping of typical surfaces of machine parts on metal cutting machines of general technological purpose.

 There are various types of heads for shaping by plastic deformation of typical surfaces of machine parts on metal-cutting machines of general technological purpose, including machines of a turning group of any automation level. In particular, axial thread rolling heads are known, equipped with a three-piece set of cylindrical threaded rollers for shaping a screw threaded surface or heads, equipped to minimize the machined diameter with a two-piece set of cylindrical threaded rollers, but with a guide sleeve for rolling small-sized threads [1].

 For rolling a cylinder into a cylinder, a method and a tool for reversing forming of medium-sized cylinders is known (2). In this embodiment, a three-piece centering set of cylindrical rollers is used, and the contact of the cylindrical calibrating surfaces of the rollers and the workpiece cylinder is point.

 A common drawback of the known technical solutions in relation to the shaping of small-sized cylindrical surfaces is the impossibility of processing small, including extremely small, less than 1 mm diameters, on the one hand, because of the impossibility of close mixing of three-piece centering sets of rollers, on the other hand, because of the need in additional devices supporting the workpiece in the heads with two-piece sets of rollers with the disadvantages characteristic of these devices.

 The objective of the invention is the expansion of technological capabilities, improving product quality and simplifying tools.

где
x и y - текущие координаты;
Σ - межосевой угол, град;
r - радиус обработанного цилиндра, мм;
или аппроксимирующей окружностью радиуса R (фиг. 3)

где
b - половина ширины калибрующей части роликов, мм;
h - стрела прогиба дуги, определяемая из
h = r -(r²- b²•sin²Σ)^1/2, мм.
Такое решение, с одной стороны, позволяет схватывать заготовку за счет вогнутой формы поверхности роликов, обеспечивая линейчатый, а не точечный контакт, и не давая такому нежесткому цилиндру заготовки смещаться с центра вследствие деформации, исключая таким образом необходимость в поддерживающих устройствах; с другой стороны, позволяет двухштучный комплект сводить к центру, предельно близко обеспечивая возможность обработки весьма малых, близких к нулю, диаметров.This is achieved by the fact that the axial head for rolling the cylinder into the cylinder, containing two diametrically located and obliquely mounted rollers, eccentric axes, small and central gears and an opening mechanism or without it, is equipped with rollers having a calibrating part in the form of a surface of revolution, forming which is an ellipse described by the equation

Where
x and y are the current coordinates;
Σ - interaxal angle, degrees;
r is the radius of the machined cylinder, mm;
or approximating circle of radius R (Fig. 3)

Where
b - half the width of the calibrating part of the rollers, mm;
h - arrow deflection of the arc, determined from
h = r - (r ² - b ² • sin ² Σ) ^1/2 , mm.
This solution, on the one hand, allows you to grasp the workpiece due to the concave shape of the surface of the rollers, providing a linear rather than point contact, and preventing such a non-rigid cylinder of the workpiece from moving from the center due to deformation, thus eliminating the need for supporting devices; on the other hand, it allows a two-piece set to be reduced to the center, extremely close providing the possibility of processing very small, close to zero, diameters.

 In FIG. 1 schematically shows a head; figure 2 - installation diagram of the rollers relative to the workpiece and the position of the elliptical generatrix of the calibrating part of the roller; in FIG. 3 is a diagram of an approximating circle; in FIG. 4 - the relative position of the rollers and the workpiece, ensuring the fixation of the latter in the center.

 The head works as follows.

 At the initial stage of the processing process, the head is captured by the rotating workpiece due to the axial feed and moves along the axis of the product. Two concave calibrating parts of a two-piece set of rollers at the same time cover the treated cylinder and prevent it from bending and leaving the processing zone. Upon reaching the required length, the head is opened and retracted without reverse rotation, or, without opening, is retracted by reverse rotation as a die.

Sources of information
1. Sultanov T.A. "Thread rolling heads." -M .: Engineering, 1966, p. 68.

 2. Copyright certificate of the USSR N 1790462, cl. B 21 H 3/00, 1993.

Claims (1)

An axial head for rolling small-sized cylinders, comprising a housing, two diametrically located rollers, eccentric axes, gear wheels or ring gears at their ends, a central gear wheel engaged with it, and a roller breeding mechanism, characterized in that each of the rollers has two conical intake parts and a calibrating part made in the form of a surface of revolution, the generatrix of which belongs to the ellipse described by the equation

where x and y are the current coordinates;
Σ is the interaxle angle;
r is the radius of the processed cylinder, mm,
or a circle approximating it with a radius R
R = (b ² + h ² ) 4h, mm,
where b is half the width of the calibrating part, mm;
h - arrow deflection of the arc, determined from
h = r- (r ² -b ² sin ² Σ) ^1/2 , mm

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