A Study of Automatic Determination of Cutting Conditions to Minimize Machining Cost

Machining cost is a most important factor for manufacturing a product. The machining cost for each machine tool is often estimated from the total cost of a factory according to the conventional method used for industrial management. The total income and expenditure of a factory can be obtained, however the operation status of machine tools is different. That is to say that an accurate machining cost for each part can’t be estimated and then cutting conditions realizing minimum machining cost cannot be discussed before a real machining operation. Hence, an estimation method of machining cost is proposed with using ABC (activity-based costing). The activities related to electric consumption of a machine tool, coolant, lubricant oil, cutting tool and metal chip are considered for total machining cost in this research. Based on the estimation method, the calculation method of cutting conditions achieving minimum machining cost is introduced and discussed. An adequate cutting condition can be obtained by calculating an approximate equation with using least-square method and exploring a cutting condition achieving the minimum machining cost with using iterative calculation in this paper. The feasibility of the proposed estimation method of machining cost and the calculation method of cutting conditions achieving minimum machining cost is demonstrated through some case studies.