Abstract: Chip controlling is the pivotal technique in the modern advanced mechanical manufacture system. If the problems of chip controlling are not solved, none of the perfect automation process can realize. The chip space movement contrail is studied systematically, and its initial movement contrail model is acquired. The restriction relation of chip and its barrier (work-piece and cutting tool) surfaces in the course of chip-forming, together with its influence on chip-forming and chip-breading, is researched. The investigation indicates the restriction relation of chip and its barrier surfaces, obtained by chip movement contrail, is effective study approach of forecasting the process of chip-forming and chip-breaking, which builds up the theoretical foundation of designing and optimizing groove.

Key words: Chip breaking, Chip forming, Constraint equation, Movement contrail