Page 128 - Modular design for machine tools

Engineering Guides and Future Perspectives of Modular Design 89

1. Extended MC capable of turning and broaching
2. Core machine for NC TL (numerically controlled transfer line) and
FMS by attaching the cluster head
3. Five-axis controlled NC machine with the NC rotary tilting table
In the beginning of the 1980s, the system machine was promptly
launched to its practical application in accordance with the second-
stage development of flexible manufacturing, where the system design
of top-down type became dominant. As can be readily seen, the system
machine grew in importance with the thriving trend of the system design
of top-down type. In retrospect, there were, as shown in Fig. 2-14, mul-
tifarious trials to develop the system machine from the late 1970s,
paying special attention to the dominant design attributes to be pro-
vided. It is surprising that very few trials were, as shown together by
framing in Fig. 2-14, as successful as those for practical use [25].
Figure 2-15 delineates a longstanding developing map of system
machines by both clarifying the weighing functions to be compatible with
the system and identifying the basic machines mentioned above, from
which the system machines were contrived. From Fig. 2-15, it can be
observed that the system machines in the early 1980s were designed so
as to reinforce the accessibility to work and tooling flexibility. The former
is represented by the column or outer column traveling type, and the
latter aims at the leverage between the productivity and the tooling flex-
ibility. In short, with the increasing number of tools, the necessity is to
provide, e.g., the auxiliary tool conveyor, additional magazine, and tool
magazine of carrying type. From this, the head changer was realized.
Obviously, a crucial issue has been whether the modular design is a
must for the system machine, when we considered the compatibility
enhancement of the machine tool with the system. For example, we can
suggest the following two machines as predecessors of the system
machine, i.e., “ that of machining method-integrated type.”
1. Type FT 600 of Ikegai make in 1981 (maximum allowable work diam-
eter 590 mm), which is an MC of extended type by facilitating the
turning function, i.e., turret column with two octangular turrets for
stationary tools and rotating tools
2. Type LM70-AT of Okuma make in 1978 (swing over bed: 700 mm, main
motor 15 kW), which is a TC of extended type with the turret column
to facilitate milling and drilling functions, as shown in Fig. 2-16

In addition, we can recognize that there were, as shown in Fig. 2-15,
some representative system machines in the mid-1980s, i.e., those for
FTL and FMC. The former and latter can be regarded as the machining
method-integrated and system function-integrated machines, respectively.