Page 137 - Modular design for machine tools

Engineering Guides and Future Perspectives of Modular Design 97

For the ease of further understanding, some characteristic features
of a Variocenter, shown already in Fig. 1-6, are depicted here.
1. To be applicable for the small and medium batch size production, the
modular design has been realized by the combination of the follow-
ing functionality and performance.
a. Stationary or movement function of machining unit along X axis
b. Traveling function of machining unit along Z axis
c. Stationary or movement function of table along Z axis
d. Machining unit with quick changing tool cassette of triangle,
square, hexagonal, or octagonal type
e. Steel welded table unit with swiveling base and tool driving DC
motor of 20, 30, or 50 kW
2. Each Variocenter is, in general, available for facing, milling, angle
milling, single and gang head drilling, threading and fine turning,
and furthermore for five-face processing with angle cassette, broach-
ing, assembly, and inspection with special cartridge.
3. It is worth pointing out that the table unit of Variocenter was already
a twin-ball screw driving type in 1984 so as to carry smoothly the
work up to 4000 kg in weight. Such a driving method became popu-
lar in the late 1990s.
4. The tool monitoring and work changing can be carried out at the out-
side of the machining space while machining.
5. In due course, the Variocenter aims at utilization within the FTL and
also the stand-alone FMC.

System function-integrated machine. The system function-integrated
machine may be defined as a compact “cubiclike FMC” having the con-
figuration similar to that of a machine as a whole. Consequently, the
system function-integrated MC and TC can be considered as the utmost
representatives of the system machine. In other words, these machine
tools have multiple and various functions with higher- density inte-
gration, showing a preferable configuration as a machine for SME and
as a basic module for the production system. Obviously, such machine
tools have been developed on the basis of the flatlike FMC, in which all
the system components, e.g., machine tool, robot, automatic warehouse
and cleaning station, are allocated in the two-dimensional space (see
Fig. 1-17).
Marwin Production Machines developed, as shown in Fig. 2-21, a
system machine through joint work under the subject of the British
Aerospace patent. In fact, the machine was designed to operate both in
a stand-alone mode and for use in the FMS by dealing a random mix of