Study on the analytical model of runout for fillet rolling straightening of large crankshafts
LUO Yuanxin
CAO Feng
YI Liqun
WANG Kaijian
HUANG Jianfei
Abstract：After medium-frequency induction hardening,large crankshafts can experience local bending deformation at the journals due to thermal distortion and uneven cooling.To ensure geometric accuracy and reduce subsequent machining allowance,it is necessary to employ fillet rolling straightening techniques on large crankshafts post-heat treatment.This paper focuses on a 16V-type large crankshaft,exploring the deformation patterns during the combined elastic-plastic forming process of rolling straightening.It derives the mathematical relationship between the crank arm deflection angle and the main journal runout for various rolling angles when rolling different journals.By integrating the Bayesian optimized Support Vector Machine(SVM)method,a prediction model for the deflection angle was established,enabling the calculation of the main journal runout for any rolling angle.Based on the discretization concept,a method for calculating the post-straightening main journal runout within the rolling angle range was proposed.A reliable analytical model for the runout of the main journal after straightening was constructed,and validation experiments were conducted.The analytical results showed good consistency with the experimental results.
Keywords：large crankshaftrolling straighteningrunoutsupport vector machineBayesian optimization
Publication Date：2024-11-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：11( 29-39 )