Page 136 - Mechatronics for Safety, Security and Dependability in a New Era

Ch25-I044963.fm Page 120 Tuesday, August 1, 2006 3:36 PM
Ch25-I044963.fm
120
120 Page 120 Tuesday, August 1, 2006 3:36 PM
new manufacturing technologies with considering the environmental impact. In this paper, a
conceptual architecture and a system design of the environmental burden calculation system are
introduced first. Then, calculation algorithm of the environmental burden due to the machine tool
operation is proposed and the feasibility of it is shown through a case study. Furthermore, using the
cost data, NC programs are evaluated from the view points of the global warming and the production
costs, and low environmental burden and low cost machining operations are discussed

SYSTEM OVERVIEW

Figure 1 shows an overview of the proposed evaluation system of environmental burden for machining
operation. A work piece information, some cutting tools information and an NC program are input to
the analysis model, the activities related to the machine tool operation and the machining process are
estimated. Then, the electric consumption of a machine tool, the cutting tool status (tool wear), the
coolant quantity, the lubricant quantity, the metal chip quantity and other factors are evaluated. Here,
other factors correspond to the electric consumption of light, the air conditioning and so on. Using
these estimated information and the emission intensities data and the resource data, the environmental
burden is calculated, when a product is manufactured. The emission intensities data means the
parameters required for the calculation of environmental burden. These emission intensities are
prepared according to impact category such as the global warming, the ozone layer depilation and so
on. The resource data also means the machine tool specification data, cutting tool parameter, etc. for
the estimation of machining process. This system can calculate the environmental burden in various
cutting conditions, because the machining process is evaluated properly. This is a novel feature of the
system.

Machine tool Machining proces
• )
Quantity olcooUml and lubric
NC program OuaiiLlvofmolaldiips
Database
Envin nmental burd inoak. lator

Figure 1: Processing flow of the prediction system developed in this research

CALCULATION ALOGORITHM
The total environmental burden is calculated by equation (1). The calculation algorithm of
environmental burden is the following.

Pe = Ee + Ce + We + ]T (7e,.)+ CHe + OTe (1)
i=\
Pe: EB of machining operation [kg-GAS] Ee: EB of machine tool component [kg-GAS]
Ce: EB of coolant [kg-GAS] We: EB of lubricant oil [kg-GAS]
Te: EB of cutting tool [kg-GAS] CHe: EB of metal chip [kg- GAS]
OTe: EB of other factors [kg- GAS] N: Number of tool used in an NC program
EB: Environmental burden