SU1191191A1 - Method of loading lathes in testing - Google Patents

Description

The invention relates to machine tools and can be used

when testing lathes.

The purpose of the invention is to expand the range of modeling cutting force in the working field of the machine by adjusting the point of application of oriented forces in the radial direction and improving the accuracy of testing machines.

Figure 1 presents the scheme of loading the caliper when cutting; Fig.2 g scheme of the method.

When machining a part 1 of radius K. with a center of rotation 0 ^ at a distance K from the center Od, a cutting force P arises with a radial P _o and a circumferential P ₁ component (Fig. 1). From the circumferential force R., on the support 2, a reactive force and a torque of 1C arise, leading to its displacement relative to the center Od.

Ъ, = Р ,, М ₁ = Р / В-К), (1)

where B is the distance from the center Od to the middle of the guides of the slide 2.

When simulating the loading of the machine, oriented orthogonal forces P _o and P ₂ are applied to the mandrel 3 fixed in the machine spindle by means of the force mechanisms 4 and 5 (figure 2). At the same time, an additional force P _{3 is} applied to the caliper 2 by means of the force mechanism 6, which is positioned with eccentricity A relative to the center Od and is directed to the oppositely oriented force P ₂ . From the oriented force P ₂ and additional P ₃ force on the caliper, total reactions arise and

0 ₂ = P _g -P ₃ , M _g = P ₂ . B-P ₃ (A + B). (2)

The condition of adequacy of force effects on the caliper during cutting and modeling is the equality of the reactive forces and moments on the caliper

= m ₂ . (3)

From this condition by the formulas (1) and (2) determine the values of oriented P ₂ and additional P ^ forces

Р ₂ = Р _п (1 + “), Р ₃ = Р,“ · (4)

Given the component of the cutting force, the coordinate K of its application relative to the center Au, i.e. the radius of the part and the eccentricity A of the point of application of the additional force P ₃ , / three tests of the machine apply oriented P ₂ and additional P ₃ according to the relations (4).

The method allows you to more accurately simulate the actual power effects on the machine when turning cylindrical and shaped surfaces of different radii and trimming the ends with a continuously varying radius of processing.

Example. When testing, it is necessary to load the machine with a force whose effect on the caliper is equivalent to the action of the cutting force

= 2000H arising when machining a part with a radius of K = 0.05 m.

To simulate the force Ρ _ή , two force mechanisms were used, one to load the machine with an oriented force, and the other with an additional force P $ acting with eccentricity A = 0.2 m relative to the force P ₂ . The additional force P ^ is selected as part of the cutting force P ₁ , proportional to the ratio of the coordinates of the point of application of the cutting force I (radius of the workpiece) to the eccentricity A: P _E = P, ~ = 2000 §φ · ^{= 500 N} *

At the same time, the oriented force is increased compared to the force P ₄ by the amount of the additional force P,: P_ =

= Р ₁ (1 + χ) = 2000 (1 + ^ -> 2500 N.

The reactive force and the overturning moment M _and on the machine support from the cutting force P ^ when the distance between the center of the guide supports and the axis of the part B = 0.3 m is O, = P. = 2000 N, M ₁ = P _l (VK) =

= 500 Nm.

The reactive force and the moment on the support when loading by the proposed method are: 0 ₂ - Pr- ^P 3 ~

- 2500-500-2000 N, M ₂ = R _g B-P ₃ (A + B) - 500 Nm. Forceful effects on the caliper during cutting and loading by the proposed method are adequate: P ^ = 0 ₂ , M ^ M ^ ,. while at loading by oriented forces, according to a known method, reactive

3

the moment is Μ = P, · B = 2000, 3 =

= 600 Nm, which is inadequate to the loading of the machine when cutting.

1191191 4

Accuracy of power simulation

effects on the support of the proposed method increased by 20.

Claims (2)

THE METHOD OF LOADING TURNING MACHINES IN TESTING, which consists in applying to the support forces oriented relative to the spindle, which simulate the components of the cutting vortex, which is based on that, in order to improve the accuracy of modeling by adjusting the point of application of the components of the cutting force in the radial direction and increasing the accuracy of testing, an additional force is applied to the caliper with an eccentricity relative to one of the oriented forces and opposite to it, the specified oriented force is increased by the amount of additional force, and The latter is chosen as a part of the cutting force, which is proportional to the ratio of the coordinate of its point of application to the eccentricity. 1611611 ^oh Ω5 Φι / ί.ί one 1191191 2