The Pressure Straightening Technology of Linear Guide Rails Using Dual Indenter-Dual Clamp System

To improve the compressive capacity and straightening efficiency of straightening process, the stroke-deflection model (SDM) using dual indenter and dual clamp system (DIDCS) for linear guide rails is developed in this paper. The DIDCS is actually simplified as a symmetrically supported beam with two symmetrical concentrated forces on the top surface of workpiece, so the straightening process is regarded as pure bending process. To explore the deflection variation during the whole process with DIDCS, the curvature-deflection model (CDM) considering the span control of dual indenter and dual clamp is firstly analyzed based on elastic-plastic deformation theory and small deformation principle. The geometrical features and material properties of linear guide rails, which are the main factors influencing bending characteristics, are then mathematically modeled for the further analysis of stress and strain distributions in straightening process. Besides, to obtain the actual bending moment model (BMM) of different model parameters, the distribution regulations of elastic and plastic regions are analyzed followed by pure bending assumptions. The bending rebound model (BRM) is established with bending moment, geometrical features and material properties, and the SDM is finally calculated by initial deflection, rebound deflection and span parameters of the DIDCS. On basis of the DIDCS, the straightening process is simulated with the established finite element analysis model (FEM) to demonstrate the longitudinal stress distribution and the reflection of different straightening stages. The proposed SDM is also experimentally validated on the ROSE-JZ50 straightening machine with different materials.