SU1380877A1 - Method of working shaped surfaces - Google Patents

Abstract

The invention relates to the field of mechanical engineering and can be used when machining three-dimensional parts with shaped surfaces. The purpose of the invention is to increase the shaping accuracy due to a more complete coincidence of the curvature of the cross section with the curvature of the elliptical shaping cylinder. Processing lead cutter, which is moved along the surface to be treated with lines. When machining, the milling cutter is cloned to the longitudinal axis of the part by an angle to form an elliptical shaping cylinder with an axis parallel to the tangent to the longitudinal section of the surface to be machined. The angle of inclination is chosen from the condition of intersection of the machined arc of the cross section of the part by the arc of the elliptical shaping cylinder while simultaneously touching it along the axis of the machining line. The angle between the plane of rotation of the milling cutter and the longitudinal section arc arc at the point of contact of the machined surface with an elliptical shaping distance is chosen from the condition of intersection of the arcs of the cross sections of the machined surface and the shaping cylinder at the boundaries of the machining line and determined by the formula /; arcsin 2 cf-: (d-Vd-Cd) where the arc deflection of the machined cross-section of the part and the arc of the shaping cylinder correspond to the chord of the C-arc, d is the diameter of the cutter, Cj is the length of the chord resting on the cross-section of the arc of the cross-section of the workpiece and a cross section of an elliptical shaping cylinder. 1 hp f-ly, 5 ill. (L 00 00 about 00

Description

The invention relates to mechanical engineering and can be used in the processing of volumetric parts with facial surfaces.

The purpose of the invention is to improve the shaping accuracy due to a more complete coincidence of the curvature of the cross section with the curvature of the elliptical shaping cylinder,

FIG. Figure 1 shows the arrangement of the arc of the cross section of the south section of the shaping surface, the result is obtained from the condition that the radius of curvature of the developed cross section coincides with the radius of curvature of the elliptical shaping cylinder, relative to the specified arc of the cross section of the part; in fig. 2 - location of the arc of the cross section of the shape-forming surface obtained from the condition of intersection of the arcs when they are simultaneously touched along the axis of the machining line relative to the specified arc of the cross section of the part; in fig. 3, the combined nodes I in FIG. 1 and II in FIG. 2; Fig. 4 is a schematic of the mutual arrangement of the milling cutter and part, a longitudinal section; in fig. 5 is a view A of FIG. four.

The method is carried out in the following way.

Within the width of the processing line, for each given cross section, the chord length is chosen, which is based on the intersection points of the cross section arc of the elliptical shaping cylinder.

The arc deflection is measured at the base of the selected chord. Calculate the angle of inclination of the cutter 1 to the tangent to the longitudinal section of the part for each specified cross section. Considering the location of the workpiece i2 during processing and the curvature of the arc of the longitudinal section, determine the law of change of the angle of inclination of the cutter 1 relative to the machine coordinates. A control program is calculated and line processing is performed on it.

The part is machined with a curvature in cross section. The part width is set much smaller than the radius of curvature. Therefore, the width of the processing line is taken to be the same as the width of the part. The angle of inclination of the cutter to the surface of the part is calculated.

The arc To the cross section of the part according to a known method is

the circle of curvature for the arc L of the cross section of the elliptical shaping cylinder (Fig. 1). At the width of the processing line AB and the equal to it base of the arc of the cross section of the elliptical forming cylinder A, B, the processing error is obtained

G,. The value of f is equal to the distance between the arc K and its equidistant with a radius (R-tOe conducted through point A.

The arc K of the cross section of the part according to the proposed method touches at one and intersects at two points with the arc of the cross section of the elliptical shaping cylinder (Fig. 2). The distortion of the surface shape consists in introducing errors and,. These are relative forming errors.

Е - artificially introduced compensating error; j is the remainder of the error E, after the introduction of the error compensation Ej. The value of EI is equal to the distance of the arc path K and its equidistant with a radius (R + + tangential to the cross section of the elliptical shaping cylinder. The absolute error when processing by the proposed method is equal to the distance between the equidistant with radii (R + f) and (H-fj) )

f "(R + f,) - (R-,) f + f, (1)

As can be seen from the ratio of the segments FA and EA

Her.

(2)

Since the values of 6 ,, Е,, Е, and В | As a rule, they are set to less than 0.3 mm, then compared to the radius of curvature of the parts being machined, these values are very small.

, 1-A, (3) fi-C, D, (A)

 , (five)

Е „ГЕ - C, D. (6)

If the arc L rotates around the point O in one of the positions, this arc intersects the arc K at the point F. With

this point A is located near point A ,; point E is near point point C near point C,. Due to the small movement made on the basis of (3) and (2) FE AF 0.3mm, i.e. with sufficient accuracy, we can assume that the point F coincides with the point A ,; point Е - with point Aj; point C - with point C ,. Since the arcs JQ AE and C, C belong to equidistant circles with the center at the point O and have the same angles of the arcs,

; m, jq

1380877

those.

0 f

(nineteen)

Consequently, when crossing the arc of a longitudinal section of an elliptical forming cylinder at the border of the processing line, i.e. at point F, the value of E is the smallest of all possible

Where

E; E, - A, F o

(21)

A

- i

g

or

E,

s, s

Means

I

DC e, - (, -fj) c, G, (10)

n, (E, -GE

), where p 1. (11)

From here

Е, п. Р Е, + Е, Е, 4 Е, (п-1). one

(12)

Because

that

„E, -E / p. - one)

45 of FIG. 5 shows that for the cutter

diameter d 2 - PV with the length of the chord (16) of the arc of the cross section of the part C; Jn

or

, , HER,

(17)

Any additional movement from point E to point F by rotation, the arc L around point O increases the length of the arc C, D by the value

p-e-7T

(18)

(8) 5

f; , + EF - fi + (E, -. E

g,

-D.i-i. . year

(22)

Means

; , -7

(23)

Ea-EL, -E, - (E, -fj)

or

7, (1 -r) -b.

(2A)

thirty

those.

   ABOUT

(25)

or

ea

(26)

From FIG. 4 that when NQ is equal to the deflection of the arc of the cross section of the part on the chord C JN, the angle of inclination of the cutter is equal to

arcsin

BUT

Rq

(27)

RQ RV - RP g - RV2 g

(28)

55

Then

arcsin

SU,. -1773:

 g 4

arcsin

five

2 j,

(29)

Moreover, the length of the working stroke for details of length I

equal to 1o 1 + (g,

rm

h% - -

Cos.

(thirty)

Claims (2)

1. A method of treating shaped surfaces with a rotating milling cutter, which is reported to spatially move along the surface to be stitched, while the milling machine is rotated relative to the longitudinal axis of the part by an angle to form an elliptical shaping cylinder with an axis parallel to the longitudinal section tangent to the surface to be treated. - y and i with the fact that, in order to achieve the accuracy of shaping, the angle of inclination of the cutter is chosen from the condition of intersection of the arc of the cross section being machined and details of the arc cross section of an elliptical cy- ) 3808776 lindra shaping while simultaneously touching them along the axis of the processing line. 2. A method according to claim 1, characterized in that the angle between the plane of rotation of the cutter and the tangent to the arc of the longitudinal section at the point of contact of the surface to be machined with the elliptical shaping cylinder is chosen based on the conditions of intersection of the arcs of the cross-sections of the machined surface and the elliptical shaping cylinder at the edges of the processing line and determined by the formula i arcsin -17 Where five 0 cf, is the arc deflection of the processed cross section of the part and the arc of the forming cylinder corresponding to the chord of the arc; d is the diameter of the cutter; WITH . - the length of the chord resting on the points of intersection of the arc of the processed cross section of the part and the cross section of the elliptical shaping cylinder. ue.f iS 5g ur TO FIG. 2 FIG. Type A FIG. ft