RU1810278C - Combination working method - Google Patents

Abstract

Usage: turning, planing, boring and milling of workpieces from structural and difficult to process materials. SUMMARY OF THE INVENTION: Combined processing is carried out by cutting with an N-facet cutter, receiving additional rotations, for example, periodic in the direction of increasing the main angle in the plan, and surface-plastic deformation, for example, with a roller mounted in relation to the cutter with an arched angle relative to the axis of the surface to be machined and with one side of the longitudinal plane of symmetry of the part. During processing, the projection of the deformation force on the direction of the radial cutting force is increased, for example, by an increase in the deformation force during the rotation of the cutter with maintaining the ratio C Ru + Pgcosa C + (5P, where Ru is the current radial cutting force; Rd is the current deformation force applied to deforming element: a is the current central angle of the deforming element and the cutter relative to the axis of the surface being treated; C is a constant value; 5P is the allowable tolerance for changing the deformation force. iju deforming force in the direction of the radial cutting forces also increase the decreasing angle relative to the roller installation tool. 2 ZP f ly-3-yl. w J

Description

The invention relates to mechanical engineering and can be used in factories for turning, planing, boring and milling workpieces from structural and difficult to process materials.

The aim of the invention is to improve the quality of processing with an N-facet cutter, which receives additional turns.

In the method of combined processing by cutting and surface plastic deformation by a roller mounted at an angle relative to the cutting element on one side with it relative to the longitudinal plane of symmetry of the workpiece, providing for a change in the deformation force during processing, according to the invention, a change in the deformation force is carried out by increasing its projection by the direction of the radial component of the cutting force during the rotation of the cutter, maintaining the following ratio:

C Py + Pgcosa C + dp, where Py is the current radial cutting force:

Rd is the current deformation force;

a is the current central angle of the deformation element and the cutter relative to the axis of the workpiece;

C is a constant value; 5p is the tolerance for a change in the deformation force.

The increase in the projection of the deformation force on the direction of the radial co00

about

N5

Xi s

stevile cutting forces are achieved either by decreasing the angle of the roller relative to the cutter, or by increasing the deformation force.

. In FIG. 1 shows a schematic diagram of the processing of the proposed method; in FIG. 2 is a side view of FIG. 1; in FIG. 3 is a fundamental change in the radial force of the cutter Ru and the deformation force Rd from the angle p of rotation of the blade of the cutter.

The combined processing method is carried out as follows.

Turn on the rotation of part 1 and the longitudinal feed of cutter 2 and roller 3 mounted on one side of the axis 4 of part 1. Cutter 2 has an initial angle in terms of pho - MIND 90 ° and removes an allowance of depth t. A force Rd Rdo is applied to the roller 3, which has a minimum value, for example, close to zero. The roller 3 is installed in relation to the cutter 2 at an angle a (a 90 °). When machining with a cutter with a principal angle in the plane p, a cutting force arises, the radial component of which RU Ru0 has the greatest effect on the spin of the elastic system of the machine and the workpiece. The Py value is considered to be a known value, which is determined either by a similar calculation using known experimental equations or by registering it by elastic displacements, for example, cutter 2 during processing. When processing, cutter 2 receives, for example, periodic turns (may have constant, continuous rotation) in the direction of increasing the main angle in terms of p. It means; that after a certain period of time, the cutter is rotated through an angle p P2 (Fig. 1). Over the course of the rotation time of the cutter, the radial component Ru will decrease in accordance with the rate of change of the angle p (see, for example, V. Bobrov, Fundamentals of the theory of metal cutting. - M.: Mechanical Engineering. 1975, p. 210. Fig. 163 ) So, if at we have Ru Rice, then at ip / E1 we have Ru Pyi Ruo (Fig. 3). Decrease. the increase in the force Ru will lead to mutual reciprocal movement of the cutter 2 and part 1, which will lead to a change in the diametrical size of part 1. (The rigidity of the front and rear headstock of the machine under these considerations is, for example, infinitely large). In order to prevent this from happening, we apply a deformation force RD11m to the deforming roller 3 during the rotation of the cutter 2 by an angle of - - „(Fig. 1) and throughout this rotation. which of

is changing, i.e., URRLICHIR.

 m

0

the intensity with which Py is reduced. That is, the current changes in the forces Rd and Py during the time Lt of rotation of the cutter through the angle Dp are mirror-opposite. In this case, the sum of the current forces Py + Pgcosa in the direction of the radial cutting force Py will be constant or will vary in the permissible limit (5P, i.e.:

С РУ + Рд С + etc. (1).

Where do we find the magnitude of the change in the deformation force:

1

cos a

(C-Ru) Rd (€ -Ru-rcSp). (2)

fifteen

0

5

0

5

0

5

0

where C is a constant value, C Cmin Ru + Pgcos a ;. . ;

Rouault is the radial component of the re- force. Zani at:

The minimum deformation force of the roller at p p0

RU - current radial cutting force;

Rd is the current deformation force; its angle of location of the roller relative to the cutter;

(5P is the allowable tolerance for measuring the deformation force, for example, 3P 2F, where F is the total friction force in the machine support;

Rdmax Ropt, where ROPT is the optimum deformation force.

If the deformation force of the roller increases from Prom Рдо by the amount Д Р of the reduction of the cutting force Ru and thus Рдо + + Д Ру РОПТ, then the roller must be installed from the top of the cutter in the feed direction S. This prevents metal over-machining of the surface of the part. . .

The stabilization of the action of radial forces in the direction of the Y axis can also be carried out by the second method, namely, by changing the angle of austening of the roller relative to the cutter, the force PQ where ROPT is the optimal deformation force remains constant. The angle a of the change at the moment of rotation of the blade of the cutter by the angle D (/ 7 - p-o.ro and during the time D t of its entire rotation by this angle.

From (1) we can determine the magnitude of the change in the current angle ":

(with RU - (С - РУ + other)

........-..- „/ ..... ft. --- ......- -... 1

 rd

C - Pv Rl

arccos (--- to -.

 arc: From about :; (

(C Ru f rt (1 j

R)

where C is a constant value, C RUo + ROPT cos Ru0 + Pgcos a:

RR GROVE.

Rouault - radical cutting force at (:

(.to is the angle of the roller when

Example. Shafts with a diameter of 100 - 0.05 mm, length I 150 mm are processed. Material - steel 40X. Processing modes: cutting depth t 3 mm, feed S 0.6 mm / rev; cutting speed V 200 m / min. Processing is carried out with a combined tool consisting of a stepping cutter with an initial angle in the plan (p fo, - 45 ° and a radius of the cutting edge g of 15 mm and a roller with the largest radius P of 20 mm. The installation angle of the roller is 10 °. At p 45 ° we have components of the cutting force; Rouault 124 kg; Rho 220 kg; Rho 90 kg. The initial pressure applied through the roller to the part is equal to Rdo Yukg. After a certain period of time, the stepping cutter is rotated through the angle Duz 2 ° to f) - / Emax 90 ° i.e., 22 turns are made. The power of Ru. as the most affecting the accuracy of processing, it changes according to the law: Ru --- 201 - 1.711 p, where f) - (DT, a) is the angular velocity of the cutter turning through the angle D | / e; g is the time of rotation.

At the first turn of the cutter through the angle D (/) 2 °, we have p (/) „+ 2 47 ° and RU1 - 201 - 1.711 47 120.6 kg. After 22 turns of the incisor we have p 90 °, Pymln 201 - 1.711-90 47 kg.

We accept the initial pressure of the roller Rdo 10 kg. When you first turn the cutter at an angle of 2 °, we have p 47 ° and Pyi - 120.6 kg. During the first turn and during the first turn of 4 s (IF- 0.087 s 1, the pressure on the roller will increase (out of 2) at 3 p 0 we have:

Py1 coG "(C

v) V cos 10 °

(R

1

+ Pyocos10 ° - Pyi) --I-- (124 + 10cos10 °

. cos 10 °

-120.6) 13.45kg

After 22 turns, the pressure on the roller is: 90 °; - 1.711 90 ° 47.1 kg.

- (Rouault PejCOS «0 - En22)

cos 10 °

(124 + 10cos10 ° - 47.1) 88.1 kg. cos 10 °

As a result of maintaining ratio (2), a constant force Py acts on the part during the rotation of the cutter by an increased angle in the plane p and during the processing. The variation in the diametrical dimensions of the shafts without changing the pressure on the roller was

it is 0.1 mm. and when the pressure of the roller changes while maintaining ratio (2), the spread in the diametric dimensions of the soybean is 0.03 mm. That is, the processing accuracy improved by 3.3 times.

The processing accuracy can also be improved by changing the angle a using relation (3) at Pg Ropt 66 kg. For the above example, we have: at 45 °, Py 124 kg. Example r2o 85 ° and 5P 0..

fifteen

25

thirty

35

40

45

fifty

5 20

COS "22

Rouault-R

-.,

r omin

+ cos85 ° 0.9825.

, 73 °.

Reducing the angle of installation of the roller during rotation of the cutter to a new angle p DB; We also strive to maintain a constant value of the total force acting on the part.

The proposed processing method is simple to implement and expands the possibilities of using combined processing. Tests of the proposed method showed its effectiveness in the processing of shafts. The method in comparison with known methods provides an increase of 3 to 4 times the accuracy of processing.

Claims (3)

1. A method of combined processing by cutting and surface plastic deformation by a roller, installed at an angle relative to the cutting element on one side with it relative to the longitudinal plane of symmetry of the workpiece, comprising changing the deformation force during processing, characterized in that that, in order to improve the quality of processing with an N-facet cutter receiving additional rotations, a change in the deformation force is carried out by increasing its projection on the direction of the radial component of the cutting force during the rotation of the cutter, maintaining the ratio C Ru + PgCOStt C + d (), Ru is the current radial cutting force: Rd is the current deformation force; ft is the current central angle of the deformation element and the cutter relative to the axis of the workpiece; C-constant; dp is the tolerance for a change in the deformation force. . 2. The method according to claim 1, wherein the projection of the deformation force on the direction of the radial component of the cutting force is increased by reducing the angle of the roller relative to the cutter. 3. The method according to claim 1, characterized in that the projection of the deformation force onto the direction of the radial component of the cutting force is increased by increasing the deformation force. Phi. G & Fie. 6