SU1563872A1 - Method of cutting bread - Google Patents

Abstract

The invention relates to the processing of metals by cutting, in particular to threading on numerical control machines, and can be used when cutting a resistant thread. The aim of the invention is to improve the quality of the thread by increasing the durability of the cutters. To do this, with each radial feed, an additional axial displacement of the cutters is made due to their resulting movement along the bisector of the angle of the thread profile, and the axial displacement is performed in accordance with the dependencies described in the description, and the length of the cutting edge of the cutting tool is also determined by the formula. 8 il.

Description

When cutting threads with an asymmetrical profile, after each pass, along with radial displacements, the axial displacements are also obtained at the same time as the radial displacements. The combination of such joint displacements of the thread cutter in two mutually perpendicular directions makes it possible to evenly distribute the size of the allowance being removed between the two sides of the tool, i.e. provide the last movement in the bisector of the angle of the thread profile

& -V1

(-o) (Fig. 1). After the rough cutter completely removes the allowance allocated to it (ЈQ; 0, the cutters are replaced, i.e., the gauge of the draft 3 is set with a calibrating cutter 4, which likewise removes 2 the remaining part of the feQ allowance) and finalizes the profile thread. Before the initial cutting with a calibrating cutter, it is necessary to carry out an additional adjustment of its2 (position of point T) in the radial L.x. and axial direction DE in relation to the initial reference point AND, chosen as the base for the rough cutter (Fig. 7). The magnitude of these corrections 3 depends on the total allowance taken by the calibrating cutter (ЈQ, K.), On the length difference between the vertex blades of the calibrating and roughing incisors, and on the angles of the cutout profile ft-, R. 3

To ensure that the cutters work along the bisector of the angle, the thread profile with an asymmetric thread profile simultaneously with the radial incision also sets the axial displacement. Since the calculation of 4 feeds is performed in the reverse order of their operation, in order to calculate the axial displacements of the incisors, after each pass, it is necessary to recoding the incisive numbers from index 4 i to j in accordance with the sequence of their work. Then, for roughing passes, the axial displacement values of the incisors are determined by the dependence5

7 -

ZJ (fc- 2

(Ј &

(one)

When the value of the axial displacement of the numerical line is 0-0. Therefore, taking into account the difference in the lengths of the cutters C (Fig. 3), we have

(3-U

ZiK (2% TC),

(2)

By simple trigonometric transformations from FIG. 1 we find

With Јq (K-Sncosy with (3)

Then dependence (2) taking into account the expression (3)

Zji (IQj + 2: QjK-C) tg

(four)

The length of the tip blade of the rough cutter B is calculated from the condition that the distance between the sides of the rough cut and clean cutters at the end of the cut is equal to the inaccuracy of the relative position caused by the clamping, fixing and indexing error of the toolholder. To find the length

HF EE-L-ft ,,

where

EH EN + N L + L n,

Where

EN1 QlKtgR

N L VK; L H ЈQlKtgy;

Ј and о h are the left and right side clearance, respectively, between the left and right cutting edges of the rough and gage cutters in their final positions, respectively.

The limiting distance is 5P at the sides of the incisors with a small value of half of the profile angles, which are selected from the allowable mutual deviation of the two incisors. So, having given the value of Ots, one finds about

"AA1 I costf ° A sin7AEA nsinfl

(five)

This cutter is based on the suggestion that the counting of radial feeds for plunging is carried out in the same way as for the draft from a single initial zero.

cost

(tgB + tgX) ZQiK-3n (+1), (6)

cosfi

where R c is the length of the tip blade of the libber cutter,

BP - axial clearance between the right

and sides

filleting of rough and gage cutters in their final positions.

Claims (1)

Formula of invention The method of threading on CNC machines in several successive passes, with two cutters — rough and finished, having a vertex and side cutting edges and operating in a profile pattern, each of which is reported to have a radial feed and longitudinal movement along the cut 1: thread, characterized in that , in order to improve the quality of the thread by increasing the durability of the cutters, with each radial feed, an additional axial displacement of the cutters is made due to their resulting movement along the profile angle bisector of cutting thread, with axial displacement produced in accordance with z; ZjK (2Qife + ЈQjK- Ots-g- where 2 O is the total radial feed of the calibrating cutter, 3-Q, V C is the total radial feed of the draft, the cutter is the difference in the length of the cross-member ,. and "- the angles of the thread profile, and the length of the vertex cutting edge of the rough cutter is determined from the ratio Bj.B K + UgB + tgR) ЈQlK-un cosj sin B + oh where B is the length of the tip of the cutting edge of the rough cutter, В «is the length of the vertex blade of the Kali buryut of the cutter, Oh is the axial clearance. eight Fm tf W PhagZ 0, Wf) & (J fl fig 2 (0) + z $ zff Grpf “E - h. V z seosi „X„ a1 X RTD / & W / X / & g- 6001 "T / 70Ј0 7 ( % P. XL (Xi Zd / Z v - / -. R & G "& g Z2) npSf And SffflZ . fiyo.7 / 70Ј0p0 / n / fesqotfgflWMiJ