Tool digital thread and closed-loop lifecycle control method for bearing-hole finishing of new-energy vehicle housings

Abstract

Dual-material bearing holes in new-energy vehicle housings, typically realized by thermal embedding a medium-hard steel sleeve into an aluminum alloy body, exhibit interface-induced excitation and non-stationary wear. These effects complicate quality assurance of D80 H6 bearing-hole finishing, where the tolerance band is only 19 μm and surface roughness must satisfy Ra ≤ 0.8 μm, while an industrial target tool life exceeds 3000 holes per reamer. This paper presents a closed-loop tool lifecycle control method oriented to smart production lines for indexable high-speed reaming. A digital-thread model is constructed to unify tool presetting data (off-machine presetter), production events, and hole-level vibration streams acquired from a tri-axial fixture-mounted sensor at 10 kHz. A hole-level segmentation strategy is proposed for dual-material structures, extracting stable aluminum, interface, and stable steel windows using rotation-synchronized timing. An interpretable anomaly score is then derived for interface bursts, while a drift/risk indicator tracks diameter evolution under full inspection. Based on quality constraints (D80 H6 and Ra) and risk thresholds, a decision policy is defined to trigger checks, insert changes, and preset updates before out-of-tolerance occurs. A case study for a Makino horizontal machining center is provided.