RU2306203C1 - Method for planetary working with use of needle milling cutter - Google Patents

Abstract

FIELD: manufacturing processes in machine engineering, working large planar surfaces.

SUBSTANCE: method comprises steps of imparting blank cross and longitudinal feed motions and imparting rotation to tool. In order to enlarge manufacturing possibilities, to enhance working efficiency due to combining finish and rough working processes, to improve roughness of worked surface and to increase useful life period of needle milling cutters, to simplify their mounting-dismounting along periphery of drive disc in diametrically opposite places, at least four needle milling cutter with individual drives are used. Speed of longitudinal motion feed of blank is determined according to given formula depending upon diameter of needle milling cutter, their number and revolution number of drive disc.

EFFECT: enlarged manufacturing possibilities, enhanced efficiency of method, improved roughness of worked surface, increased useful life period of needle milling cutters, their simplified mounting-dismounting operations.

2 dwg

Description

The invention relates to mechanical engineering technology, namely to the machining of large planes in order to remove slag from the surface of metals, corrosion products, mill scale, burrs, metal cutting by needle milling, and is intended to mechanize deburring, rounding edges and processing planes on milling, multi-position and multioperational machines.

A known method of cleaning surfaces from corrosion products, scale, etc., and a device for its implementation, comprising a drive disk with tufts of pile alternately arranged around its circumference and installed in through holes of the disk with abrasive cylinders [1].

The disadvantages of the known method and device is the inability to intensify the process of processing and removal of metal due to the fact that the abrasive cylinders rotate only due to friction forces, in addition, as the abrasive wears, the cylinders will be pressed against the work surface with less force due to the properties of the clamping springs, the method and device do not allow the full use of the cutting properties of the abrasive, which requires a very high rotation speed (of the order of several thousand revolutions with such small diameters wood) disc, which is difficult to implement on dynamic considerations thus will decrease the performance and quality of processing. In addition, with an increase in the clamping force of the device to the surface to be treated, the tufts of the pile will bend as much as possible without cutting the metal.

The objective of the invention is the expansion of technological capabilities to intensify the process of needle milling, the ability to remove the allowance of metal left under the rough and finish needle milling in order to improve the roughness of the machined surface, as well as increase productivity and durability of the tool, simplifying its installation and dismantling.

The problem is solved using the proposed method of planetary needle-milling processing of flat surfaces, in which the workpiece is informed of a longitudinal and transverse feed, and a tool containing a drive disk is rotated, moreover, along the periphery of the drive disk in diametrically opposite places, there are evenly installed needle cutters with individual drives in quantity at least four, while the longitudinal feed rate of the workpiece is determined by the formula:

S _CR = d · z · V _D / π · D,

where S _CR - the speed of the longitudinal feed of the workpiece, mm / min;

d is the outer diameter of the needle, mm;

z - the number of needle cutters on the disk, simultaneously working, pcs .;

V _d - the speed of rotation of the disk with needle cutters, mm / min;

D is the diameter of the disk on which the needle cutters are located, mm.

The essence of the method is illustrated by drawings.

Figure 1 shows a diagram of a planetary needle-milling processing of a flat surface according to the proposed method, side view; figure 2 is a processing diagram, a top view of figure 1.

The proposed method is intended for acupuncture processing of flat surfaces of great length on milling, multi-position and multi-operation machines. The workpiece is informed of the longitudinal feed S _pr and the lateral feed S _pop to the double stroke of the table, and the tool - the rotational movement V _d and the needles - V _and .

Since the tool contains a drive disk 1 with a tapered shank 2 for mounting the disk in the machine spindle (not shown), rotating with a circular feed speed V _d , on which, along the periphery in diametrically opposite places, needle cutters 3 with individual drives 4 are installed uniformly around the circumference with diameter D in an amount of at least four, then each cutting wire bundle of the needle cutter 3 makes a complex planetary movement. The angle between adjacent needle cutters is denoted by α.

The circular feed speed V _{d of the} disk and the longitudinal feed S _{pr of the} workpiece are interconnected by the following condition: when the disk 1 with the needle cutters 3 is turned through an angle α, the workpiece must move a distance S _i , no more than the needle cutter diameter d (shown in Fig. 2 by a thin line), t .e. for one revolution of the disk, the workpiece moves a distance d · z, mm, therefore

S _ol = d · z, mm / rev., Or S _ol = d · z · n _d , mm / rev .;

where S _CR - the speed of the longitudinal feed of the workpiece, mm / min;

d is the outer diameter of the needle, mm;

z - the number of needle cutters on the disk, simultaneously working, pcs .;

n _d - the frequency of rotation of the disk with needle cutters, which is determined by the formula:

n _d = V _d / π · D, min ^-1 ,

where V _d - the speed of rotation of the disk with needle cutters, mm / min;

D is the diameter of the disk on which the needle cutters are located, mm.

Substituting the value of the disk rotation frequency in the first expression, we obtain the formula for the longitudinal feed rate of the workpiece:

S _CR = d · z · V _d / π · D.

Before starting work, the working surface of the wire pile is edited. As a pile, a steel spring wire with a diameter of 0.5 ... 1.0 mm from 65G steel is used. The working surface of the bundles of wire pile of all mills is corrected by grinding them in assembled form.

In the process of processing the surface of a longitudinally moving workpiece, the tool is pressed against it with interference N.

To carry out the processing, it is necessary that the hardness and tensile strength of the material of the wire elements of the pile needle bead are 1.5 ... 2 times higher than these parameters of the material of the workpiece, the ratio l / i, where l is the cantilever departure of the wire elements of the pile from the needle body ; i is the smallest radius of inertia of the cross section of the wire elements, was in the range of 50 ... 100, and the coefficient K _{p of the} density of the wire pile was in the range of 0.7 ... 0.9; while the tightness should be H = 0.7 ... 1.5 mm. The peripheral speed V _and processing 2 ... 5 m / s.

Tests of the tool during the processing of billets from a hot-rolled strip of steel 20 according to the proposed method showed that the tool cuts off the scale from the surface to be treated together with the hardened layer, while in the process of needle-milling the treated surface is not hardened, the pressure of the device against the workpiece surface is 200 ... 600 N per 10 mm of the width of the working surface of the device, and the tangential component of the cutting force is 150 ... 550 N. With the diameter of the needle cutter d = 100 mm and the diameter of the disk D = 1000 mm, the processing time ki of the present method a tool of four iglofrez 1.4 times less time processing audio iglofrezoy under identical cutting conditions.

The choice of the appropriate pressure depends on the physicomechanical properties of the material of the wire pile, on the rigidity and density of the latter, as well as on the interference fit [2].

When processing metals by the proposed method, the hardness of the treated surface does not increase. Thanks to multi-tool adjustment, the quality of processing improves, the roughness of the surface being machined, as well as the processing productivity and durability of the tool are increased, technological capabilities for intensifying the needle-milling process, the ability to remove metal allowance left under rough and fine needle-milling in order to improve the roughness of the processed surface are expanded.

Information sources

1. A.S. USSR 1493248, MKI A46B 7/08 // B24B 45/00. Device for surface treatment. Perepichka E.V. and Skalko N.S. Application No. 3984461 / 31-12, application. 12/04/85, publ. 07/15/89. Bull. No. 26 is a prototype.

2. Gavrilenko I.G. A method of combining preliminary and final needle-milling stripping of cylindrical parts // Automation and modern technology. - 1992. - No. 9. - S.27-30.

Claims (1)

A method of needle-milling processing of flat surfaces, in which the workpiece is informed of a longitudinal and transverse feed, and the tool containing the drive disk is rotated, characterized in that at least four needle-cutters with individual drives are uniformly installed on the periphery of the drive disk in diametrically opposite places, the speed of the longitudinal feed of the workpiece is determined by the formula S _CR = d · z · V _d / π · D, where S _CR - the speed of the longitudinal feed of the workpiece, mm / min; d is the outer diameter of the needle, mm; z - the number of needle cutters on the disk, simultaneously working, pcs; V _d - the speed of rotation of the disk with needle cutters, mm / min; D is the diameter of the disk on which the needle cutters are located, mm.

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