Takao Yoneda

Study on the Development of Grinding Systems with Learning Function.

In recent years, the form of production desired in mechanical manufacturing plants is shifting from mass production of a small number of products to small lot production of a variety of different products. Therefore, the realization of effective manufacturing systems suitable for this form of production has become an important desideratum. In this context, attention has been directed toward the solution of these requirement by using “autonomous machines”, i.e., equipment incorporating intelligent functions with a view to decentralized autonomous systems. However, in many cases, the systems so formed are ill-structured and the realization of highly complete “autonomous mechanical systems” at the very commencement of operation is difficult. That is, the machine must be a “mechanical systems with learning function”, possessing the capability of independently learning the pattern of dynamical changes in the operating environment, and updating or refining its own knowledge or operational characteristics accordingly. In the present article, an “autonomous mechanical systems with learning function”, capable of rapid and flexible event-driven or request-driven response to an instantaneously changing environment, is proposed. The basic structure of this type of machine is clarified, and, focussing the discussion upon grinding processes, the methodology of organizing grinding systems with learning function is described.

Development of High-Accuracy Crankpin Grinder Using a Servo Synchro-Drive Work Spindles.

Crankpin grinding differs from ordinary cylindrical grinding processes. Because, the center of pin portion has extreme offset from the center of journal portion. So, the left and right work spindles are required to have a mechanism for clamping and driving the journals by means of eccentric chucks on both sides of the crankshaft. With such an eccentric work spindle drive system, synchronization accuracy of the work spindles has influence on the roundness, phase accuracy, and several other characteristics of the crankpin grinding accuracy. To cope with these problems, it was developed a servo synhro-drive system, which drives the work spindles independently with AC servo motor, compensating for the phase difference between the two work spindles with the NC system. This paper first discusses several factors which prevent the achievement of high-speed high-accuracy crankpin grinding when the conventional work spindles is used. Secondly, it proposes the newly developed work spindles using a servo synchro-drive system for the purpose of achieving high synchronization accuracy. Finally, it describes the grinding results obtained by crankpin grinder equipped with the newly developed work spindles.