SU812447A1 - Method of choosing tangential feed of work at milling spherical surfaces - Google Patents

Description

(54) METHOD FOR EXTERNAL TANGENTIAL FEEDING OF THE DETAILS AT MILLING SPHERICAL SURFACES

view A in FIG. 1 for surface treatment when in FIG. 3 - the same when

- / 2;

The degree or coefficient of displacement of adjacent cuts, and for milling, is the fraction of the displacement of adjacent cuts (during turning, the proportion of the displacement of the tool) from the length of the additional cutting edge of the tool. Since when milling spherical surfaces according to the method of "tubular inst. If a single-tooth cutter with a cutting tooth has an additional cutting edge, the overlap of adjacent cuts differs radially in different parts of the surface, then the degree of displacement of the cuts, and this type of processing refers to the place where the amount of cutting cuts is maximum. For surfaces, the radius of the outer dimension of which is more than / 2 from the radius of the circle of the cutting path of the cutting part of the cutter Gu, this place is a circle with radius V2ii |; for surfaces whose radius of the external contour is equal to or less than%, such a surface area will be its periphery.

When machining parts 1 single-toothed cutter 2 with a tooth-cutter 3 reported rotation. The main movement, the cutting movement, is performed with the milling cutter 2; the feed movement is carried out by rotating part 1. Manufacturing the cutting, the cutter 3 leaves the cuts on the surface to be fabricated (Fig. 2 and 3). The amount of tangential feed of the part So is selected taking into account the length of the additional cutting edge of the cutting tooth, the degree of displacement of adjacent cuts a, the outer envelope of the spherical surface made (radius r) and the size of the cutting path of the milling cutter tooth (radius Hz). In this case, the tangential feed, chosen in a known way and taken equal to the product a.1, is adjusted depending on the circumference of the outer contour of the surface to be made and the size of the circumference of the cutting path of the milling cutter tooth, for which the dimensions of these two processing parameters are taken, the ratio of their radii (or diameters) and compares its obtained value with the value of 1Г27. When processing, when the ratio of the radii of these parameters is less than V (or when, because r-y2g2), the feed increases and BE1 mask f / r 2 (Figure 2). when con-VTjr;

their ratio is equal to or exceeds / 2 (or when rm m), the tangential feed is increased by the value of the obtained ratio of the radii (Fig. 3).

When selecting a feed in this way, when it is determined already taking into account the external dimension of the spherical surface being made and the size of the circle of movement of the cutting part of the cutter-cutter tooth, it is corrected depending on the sizes of the circles of these parameters and by certain ratios of their radii increase by The higher the number of times, in most cases, the increased feed of the part 1.2-1.95 times against the feed, when it is chosen only from the length of the additional cutting edge of the cutting tooth and the degree of displacement of its adjacent x incisors.

Making surfaces with higher feed rates shortens the machining time and increases the productivity of the milling process. In this case, in a number of cases, the treatment time is almost halved.

Example. In the manufacture of spherical surfaces on parts made of bronze (in the manufacture of a reflector, metal optics parts) with a diameter (d 2r) of an outer contour of 1000 mm with a single teeth freya with a diamond cutter having an additional cutting edge of a length of 5 mm and a diameter of a trajectory of movement of the cutting part cutter (), equal to 520 mm finishing of this surface, carried out in three passes (i) with the desired degree of displacement of the cuts a 0.5 (i.e., when the cutter is at the maximum, the displacement of the cuts passes through the same area of the surface and twice) and at a cutting speed of Mind. 800 m / min, produced:

a) when selecting innings, when it is carried out in accordance with the existing concepts, i.e. when the tangential feed of the part is set on the basis of the length of the additional cutting edge L and the degree of displacement of the cuts a, over the next time:

. : N: ZG-d .. ar.d. t t

Aet. So

1000-VM gr-iOOO ZG .520

O 7 Cumin i

OjS-O.S 1000-800

6) in determining the supply when it is conducted by the proposed method, i.e. when the tangential feed is already established also taking into account the outer dimension of the surface to be made and the size of the circumference of the cutting path of the cutter and is adjusted depending on the dimensions of these parameters, the required time is (feed So is increased by the ratio as -% 0 -V 1.92, i.e. greater than 2, equal to about 1.41)

-l - 3rd.: EG d FGD. SM So-itn ttE-- 1000-V "

  NT IOOOVH 1000. Comparison of the processing time produced with the feeds selected by both

By the ways, it can be seen that in absolute value when milling one surface, the proposed method of determining feeds gives a reduction in time of 37 minutes or in relative values a reduction in time is 1.92 times.

Claims (1)

Invention Formula The method of selecting the tangent part feed when milling spherical surfaces with the end of a tubular tool with a cutting tooth having an additional cutting edge with an auxiliary angle in the plan equal to zero, in which the feed of the part per revolution of the cutting tooth is chosen based on the length of the additional cutting edge of the cutting tooth and the degree of displacement of its adjacent cuts and is taken equal to the product of the specified processing parameters, characterized in that, in order to increase productivity, the feed is adjusted depending on the size of the circumference of the outer contour of the spherical surface being machined and the trajectory of the cutting part of the cutter tooth, the ratio of the radii of the specified parameters is determined and if the ratio / 3 is equal or exceeded, the feed is reduced to this ratio, and it is increased by an amount equal to 1 VH, -f, d is the radius of the circumference of the outer congde of the spherical surface being machined; Hz-radius of the trajectory of the cutting part of the tooth-cutter cutter. Sources of information received during examination 1. Petrushin V.K. Mill for fine milling. Sat “Exchange of experience in radio industry. M., NIIEIR, 1977, № 7.