Abstract
This paper deals with a new production system model, proposed and developed by the authors, for manufacture of products at lower cost and higher quality by introduction of small production machines. In such a system, only the assembled products are totally inspected directly for their functions and quality , while the quality of individual parts that compose the final products are assured, not by measuring themselves but by monitoring the their production parameters, based on theory that if only the production machine works normally, the part or final product produced with it must be of required quality. There are two critical factors that dominate such production system function, which are process or quality evaluation and effective process monitoring. To determine whether the machine works normally or not, we applied MT （Mahalanobis-Taguchi）system. This production system needs a single molding and measurement of the production process with low noise. To meet these requirements, the authors have developed a small injection molding machine and a small press machine. Each machine has a precise force sensor embedded in its mold for measuring the machine motion during the machining process. The small mold has a size of 80mm x 130mm x 80mm. It allows low noise measurements of the processes, and one-to-one correspondence of the product data and process data. Using the small production machines, we carried out experiments to produce micro parts. The experiments showed that the new production system could determine the quality of the products from the measurement data of the machine motion. The result indicates it is possible to increase the quality of the products and to decrease the cost of the quality management.
