Page 13 - Modular design for machine tools

Preface xi

In the beginning of the twenty-first century, there have been some
symptoms for new modular design concepts with the growing importance
of localized globalization in the production in full consideration of the
compatibility of the production facilities with the natural environment.
More specifically, the modular design is being requested to incorporate
the modules in closer relation to the multiple-function integrated type,
culture- and mindset-harmonized type, and to the environment-harmonized
types, e.g., indigenous available, performance up-to-date, and LCA (life
cycle assessment) modules.
Meanwhile, a tedious work in the modular design is to determine a
group of modules (principles of separation and unification) and a suit-
able combination of modules from it in accordance with the design spec-
ifications (principles of connection and adaptation). Up to the second
phase, the designer managed these works with the trial-and-error
method, especially based on her or his long-standing experience and flair.
A new innovation in the third phase has thus been the machine tool
description to assist the modular design of software aspect by the
computer. In fact, the machine tool can be represented by, e.g., the
directed graph, that is, structural pattern, where each vertex has its own
property. Thus, the combination of modules, e.g., generation of structural
configuration (pattern), can be carried out without any difficulties, with
the aid of graph theory, where the structural pattern is converted to the
adjacency matrix suitable for the computation. In contrast, the static and
dynamic stiffness of the jointed surfaces was vigorously investigated at
the second phase. The joint stiffness is one of the leading factors in the
application of the principle of connection to the practical design, and a
sphere called engineering design for machine tool joints was duly estab-
lished, although there remains something to be seen. As a result, at pres-
ent we can calculate or compute the static and dynamic stiffness and the
thermal deformation of the machine tool as a whole in consideration of
the joint to some extent. In fact, there are significant differences between
both the structures with and without joints. In addition, nearly all
industrial machines are designed on the allowable stress principle
whereas the machine tool is, as widely known, designed on the allow-
able deflection principle, and thus the joint deflection is very dominant
in the hardware aspect of the machine tool design.
In summary, the modular design is very popular now; however, the
machine tool engineer often faces difficulties to get some reference books
for the modular design together with touching on its long-standing his-
tory. This book can systematically provide the reader with necessary and
valuable knowledge about the modular design, ranging from the basic
idea and engineering guides, through the machine tool description, to
the engineering design of the machine tool joint. In addition, the book
touches on a valuable experimental technique, i.e., measurement of the