PROCEDURE OF DIAGNOSTICS OF ELEMENTS OF CLOSED DYNAMIC SYSTEM OF LATHE Russian patent published in 2000 - IPC

FIELD: solution of problem of evaluation of dynamic state of elements of lathe. SUBSTANCE: procedure includes measurement of static gives, inherent frequencies and vibration decrements of key elements of dynamic system of lathe and determination of their transfer function in the form of vibration elements. Transfer function of equivalent elastic system is formed by obtained characteristics: W_o= W_xx•cosα•cosβ•sinϕ+W_zz sinα•cosϕ,, , , where W_xx, W_xx1, W_xx2 are transfer functions in cutting zone between cutting tool and billet stipulated by dynamic give of carriage and spindle groups in lateral direction along axis OX, W_zz is transfer function of carriage group in longitudinal direction along axis OZ, α is angle of cutting direction with plane OXY, β is angle of projection of force P on to plane OXY with axis OX, ϕ is main plan angle of cutting tool, k₁, k₂, k are corresponding static gives, T₂₁, T₂₂, T₂ are constants of inertia, T₁₁, T₁₂, T₁ are constants of damping, p is parameter of Laplace transform. Then maximum negative value of real component - -Re_maxW_o(ω_o) is determined and adopted as parameter characterizing relative vibrations between cutting tool and billet, frequency ω_o at which -Re_maxW_o(ω_o) is found. Later real components ReW_xx1(ω_o) cosα•cosβ•sinϕ,, ReW_xx2(ω_o)cosα cosβ sinϕ,, ReW_zz(ω_o) sinα cosϕ are determined and used to find out predominating element which is cause of instability. EFFECT: reduced labor input, simplified diagnostics of closed dynamic system of lathe by characteristics of individual elements taken for open system. 6 dwg