SU1355355A1 - Method of machining surfaces of rotation - Google Patents

Description

gjue.J

The invention relates to methods for treating materials by cutting with combined tools in the kinematic crushing of chips and can be used in mechanical engineering.

The purpose of the invention is to increase productivity while ensuring the required degree of chip shavings.

FIG. 1 shows the relative position of the workpiece and the combined tool and the movements it communicates, a plan view; in fig. 2 - the same, side view.

The workpiece 1 is machined with a combination tool in the form of a turning tool 2 and a cutting head Z. In the course of machining, the workpiece and the cutting head are informed by rotational movements around parallel axes. At the same time, the combined tool is informed of the feed movement S along the workpiece.

The ratio of the frequencies of rotational movements of the cutting head and the workpiece is determined based on the condition of equality of the lengths of the chips cut by the lathe cutter and the head cutters, and ensuring a given degree of chip reduction by the ratio

1 7 /

TiDs K

1-z

where is x

 P2

P

3

Pl p,

one

the ratio of the frequency of rotation of the cutting head and the workpiece;

rotational speed of the cutting head;

rotational speed of the workpiece; billet diameter;

- chip shortening coefficient, which is determined experimentally

- the number of incisors in the head;

- the length of the chip cut, cut off by the combined tool.

The relationship for determining gear ratio 1 is obtained as follows.

When the workpiece 1 and the cutter head 3 rotate, the cutters of the head move relative to the workpiece along cycloidal curves that intersect the cross-section of the workpiece and form it into a polygon with curvilinear sides (Fig. 2). Thus, crushing

chips, cut off by the head 3, and conditions are created for reliable crushing of the chips with a turning cutter 2 forming a predetermined surface with a diameter D.

Each of the head heads during cutting with the workpiece cuts off chips from it, the maximum length of which (Fig. 2) is expressed by the equality

one -

where DJ is the diameter of the workpiece.

Consequently, with given D ,, Z and K, the degree of chip shavings by the head is achieved if

i il n.

The separation of chips, cut by a turning tool, into separate segments occurs at moments corresponding to the minimum depth of cut. The maximum length of each of these segments (Fig. 2) is equal to

one "

where D is the diameter of the treated surface.

The required degree of grinding chips with a turning cutter is achieved at

35

one /

77D K-1Z

Since the diameters of the workpiece Da and the machined surface D are different

40 is insignificant, the chips cut by the head and the lathe tool are almost the same length, and the ratio of the rotational frequencies of the tool head and the workpiece is expressed by the dependence

one

P1

7D K 1Z

The cutting speed V for the cutting head is equal to the sum of the peripheral speeds of the workpiece and the cutters, i.e.

V, JT dn +. 7Г Dn ,,,

or

55

V, irdn, (d i + D).

one

Therefore, the frequency of rotation of the workpiece when machining the cutting head is expressed by the dependence

Vi

T / (d i + D)

Cutting speed for turning tool Vj TTDnj. Therefore, n, V DV. When setting, set the smaller of the values of pi n. The values of the speeds V. and V and. feed S take nor 7

mativam cutting modes.

Example. Initial data: diameter of the workpiece DJ 312 mm; diameter of the processed surface is D 300 mm; workpiece material - stainless steel 1X18H10T; equipment - a lathe equipped with a combination tool - a prism turning lathe and a cutting head with a diameter d of 160 mm, with eight incisors (Z 8). The axis of rotation of the head is set parallel to the axis of the workpiece. According to the standards of cutting modes, the following are accepted: the material of the cutting part of the incisors is the hardened alloy VK8; cutting speed with a cutting head V 81 m / min with a turning tool - V 52 m / min; feed S 1.0 mm / rev blanks.

The ratio of the rotational frequencies of the cutting head and the workpiece is determined.

one .

JT-312. 0.75 100-8

Accepted.

The calculated value of the frequencies of rotation of the workpiece during machining cutting

dexterous

81

 Y (0.16. 14-0.3l2-f ° Rated value of the frequency of rotation of the workpiece for the turning tool

52

P, .

I -0,312

53 rpm

Of the two calculated values, the smaller is assumed, i.e. p 53 rpm The closest to it value of the rotation frequency of the machine's spindle is 50 rpm, therefore, adjust n, 50 rpm. Since i 1, the frequency of rotation of the head HU 50 rpm is adjusted.

The profile of the surface machined with the cutting head with i 1 HZ 8 is limited by eight circular arcs whose radius is equal to the sum of the radii of the cutting head and the given surface, i.e. 230 mm. Turning tool

0

5 0 5

0

Q

g

The target surface is 300 mm in diameter.

The thickness of the metal layer cut by the head incisors varies smoothly from 0.5 to 5.5 mm, and the turning cutter varies from 0.5 to 5.0 mm over a length of 120 mm, thereby ensuring reliable crushing of the chips cut by the combination tool. Taking shrinkage into account, the length of individual chip elements does not exceed 90 mm.

A smooth change in the thickness of the metal layer being cut by the turning tool and the head cutters is ensured by the parallel arrangement of the axes of the head and the clamping. With this arrangement of the axes, the cutting head removes about half of the metal layer being cut off by the combination tool during processing, which is not the case in the known method. Due to this, with the same load on the cutter, it is possible to approximately double the feed, and, consequently, technological performance.

Claims (1)

Invention Formula The method of processing the surfaces of rotation with a combination tool in the form of a turning cutter —and continuously rotating around its axis of the cutting head when the workpiece is communicating rotation, and the combined tool — feeding movement, characterized in that, in order to increase the grinding rate, the rotary movements of the cutting head and the workpiece are carried out around parallel axes, and the ratio of their frequencies is adjusted on the condition of equality of the lengths of the chips, cut off current molecular cutter and cutter head from the ratio 1 g TruK 1-Z Pl de 1 - - is the ratio of the frequencies of rotation of the cutting head and the workpiece; n, j, is the frequency of rotation of the cutting head; n is the frequency of rotation of the workpiece; DI is the diameter of the workpiece; K - chip shortening factor; 1355355 Z - the number of incisors in the head; 1 - the length of the chips, 6 shear combined tool. fl3 (picture 2 Editor and. Casarda Compiled by V. Semenov Tehred M. Khodanich Proof-reader V. But ha Order 5742 / t1 Circulation 970 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