Page 106 - Modular design for machine tools

70 Modular Design Guide and Machine Tools Description

machining process in consideration of form-generating movement.
Although the proposal is far from being realized and remains a serious
problem to be solved afterward, i.e., guarantee of the one-to-one con-
2
version of functionality to structural configuration, the separation into
the reasonable module becomes easy together with the guaranty of the
greater adaptability of each module at smaller expenditure. In fact, the
proposal of Tönshoff et al. can be characterized by the use of both more
function-oriented modules and the conversion method based on the QFD
of hierarchical type. In other words, the user’s requirement can be con-
verted first to the function to be provided to the machine and then to
the structural configuration module. A key issue is thus how to actually
carry out the QFD. In due course, Höft and Ito [9, 10] proposed a simi-
lar idea in the design of the culture- and mindset-harmonized product
(localized community-oriented product) including the machine tool with
modular design, where the basic necessity is also to convert the uncer-
tain attributes related to the culture and mindset to the quantified engi-
neering specifications in consideration of the superiority order of each
attribute, or by weighing the relative importance of each attribute. In
the proposal of Höft and Ito, this weighing procedure can be displayed
by using the radar chart.
In addition, the proposal of Tönshoff et al. emphasizes both the con-
siderable benefits to the manufacturer, which can respond to users’
requirements in wider scope than ever before, and the higher exchange-
ability of the module at the user’s factory. In fact, the functional module
should be determined in consideration of the manufacturing require-
ments of the user as follows.
1. The future product spectrum, which could be dealt with for the
machine tool being conceptualized
2. Predictive production capacity
3. Organizational and investment limitations
It is worth pointing out that the modular selection procedure is inno-
vative in Tönshoff et al., because of arranging the modules first so as to

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The utmost difficulty lies in the differing properties in the related information between
the functionality and structural configuration, e.g., those of uncertain and qualitative
design attributes versus quantified engineering specifications. This conversion is as same
as that in the CAPP where the part (geometric) information on drawings must be converted
to completely different (machining method) information. The same problem can be
observed in the work of Abele and Wörn, in which a modular design has been proposed
ranging from the functional entity, through the structural body component, to the work
grasping and cutting tool.
Abele, E., and A. Wörn, “Chamäleon im Werkzeugmaschinenbau—Rekonfigurierbare
Mehrtechnologiemaschinen,” ZwF, 2004, 99(4): 152–156.