Seii Miyakawa

Automatic assembly line for VTR mechanisms

An automatic assembly line for VTR mechanisms was developed. The line, 88% of the stations on which are automated, consists of 56 dedicated automatic assembly machine stations, 11 robot stations, and 9 manual assembly stations. Prior to development of the line, the product design was reviewed by using the Hitachi Assemblability Evaluation Method. System design was carried out effectively with the help of computer simulation. The installation of robots and modularized, standardized stations provided line flexibility. The robots are used for delicate and precise subassemblies of complicated shape. Development of this line reduced assembly labor to 1/6th, the necessary assembly shop area to 1/3rd, and the readjustment rate of the final assemblies to 1/5th upon line completion. Performance has subsequently been doubled.

Assembly reliability evaluation method (AREM)

This paper introduces an effective new design-for-quality tool called AREM that visualizes assembly fault potential. Its evaluation formula is constructed on a fault occurrence model and enables quantitative evaluation of the fault generation potential of both product and assembly shop. The distinctive features of AREM are:(1) visualization of parts and operations having a high fault probability detection capability; (2) easy input by symbol selection as well as simultaneous assemblability evaluation; and (3) shop reliability, as well as product reliability, can be evaluated quantitatively. The method can be integrated with other DFX tools such as the assemblability evaluation method (AEM), and the recyclability/disassemblability evaluation method (REM/DEM) to realize a comprehensive production design evaluation system.