SU1252075A1 - Rotary-bit face milling cutter - Google Patents

Description

The invention relates to cutting tool designs.

The purpose of the invention is to increase the drainage of the tool by aligning the cutting paths that pass through the material being machined with blades of self-rotating rotary cutters, which perform roughing and finishing of the surface.

FIG. 1 shows a milling cutter; in fig. 2 - cutting element; in fig. 3, section A-A in FIG. 2,

The milling cutter consists of the body 1, the rough 2 and the finishing 3 cutting elements located in the sockets of the body 1 at a different distance from the milling machine axis and at a different height along its axis, and the balancing device 4.

The cutter works as follows.

The workpiece is fed to the mill. When approaching the rough cutting element 2 installed with a large angle d, it begins to be processed by it. Rough cutting element 2 cuts off thick chips and leaves behind a relatively deep kinematic wave. Moving further, the workpiece falls into the zone of action of the finishing cutting element 3, installed at a small angle d, which cuts off fine chips, cleansing the traces of the rough cutting element 3.

The blunting of the cutting elements is determined, other things being equal (the material of the cutting elements, their geometry, the material being processed, the cutting speed) by the parameters of the cutting chips and the length of the cutting path that the cutting elements pass through during the processing of the material. The parameters of the cutting chips on the intensity of cutting elements when cutting wood are affected relatively little and this effect is taken into account by the empirical coefficient k,. The cutting path that the rotating cutting elements go through depends on their geometrical parameters and on the parameters of their installation relative to the material being processed and its influence on the cutter blunting process can be taken into account by the kinematic coefficients 1, and P, where, is the utilization ratio of the useful blade length; Blade length margin stock.

hj is the coefficient;

pf 1

where Fe.6p is the surface area;

Pppj - conditional value, called the area of cutting,

..

the width of the treated surface; feed to cutting element

,

where ft and where

L

cutting path;

t is the length of the active (in contact with the material being processed) parts of the blade.

For a round cutting element, the useful value of the blade length 1 is determined by equation (1):

1 - ° SP.

and"

In 90

re 5

(H,)

Where

R

cutter radius;

g is the radius of the cutting element;

H - the angle of contact of the cutting element with the material being processed within the surface to be treated;

H - the contact angle of the cutting element within the treated material outside the machined surface;

40

, --2arcs "n

H z

; QrCCOS

-0.5,

where A is the angle of the blade;

d is the back angle of the cutting element;

t is the cutting depth of the cutting element.

Hh, 5

The overall relative resistance of the cutting element is determined by the coefficient of relative kinematic resistance.

one - ,

It is possible to provide the same durability of the cutting elements that cut chips of different sections, provided that the rough and finish cutting elements have the same coefficients and 1. For this, it is sufficient that they contact the material being processed on an arc that is defined by the same angles.

H g h h. The angles of inclination of the blade of the cutting elements D can be made the same, which is easy to implement. In this case, the equality of the angles

and determined from the equation.

SinoC,

de t and t.

o.and

cutting depth for roughing and finishing cutting elements, respectively; rear corners roughing and finishing cutting elements, respectively.

Moreover, tj is equal to the value of the excess of the finishing cutting element above the rough one –dC, and t is LC, where t is the depth of cut of the cutter, then

respectfully

Sin oL

SinoL

t - ah

Fig 2

Editor N. Bobkova

Compiled by V. Zoletev

Tehred I. Bonkloh Corrector T. Kolb

- Order 4568/14 Circulation 1001 Subscription

VNIIPI USSR State Committee

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

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

Claims (1)

A face rotary cutter, comprising a body, a rough and fine cutting elements mounted on it at different distances from the axis and at different heights with a slope that provides rear angles, characterized in that, in order to increase tool life, the inclination angles of the cutting elements are made different proceeding from the values of the rear angles determined from the ^relation Sind, t - AB Sin d _g 'Ah where ¢ 4 ,, d ^ are the rear angles of the rough and fine cutting elements, respectively; Ak - the excess of the finishing cutting element over the draft; I - the depth of cutter. SU ... 1252075 FIG. 1 from the axis of its axis, 4. ob1252075