【正文】 and of the machine tool. 5 CONCLUSIONS This study has shown that the machining time dominates energy demand for high tare machine tools. Additionally, it has provided a method for characterizing the specific energy of a machine tool as a function of process rate, which can be extended to other types of manufacturing processes. The specific energy model allows a product designer to estimate the manufacturing energy consumption of their part’s production without needing to measure power demand directly at the machine tool during their part’s production. Since the specific energy as a function of . for the micromachining center presented herein varied by as much as an order of magnitude, it is important to use process parameters and machine toolspecific data to determine accurate electrical energy consumption. This model could therefore be used in place of aggregate embodied energy values for manufacturing processes as provided by [9] or to replace process estimates with great uncertainty when conducting hybrid life cycle assessments.6 ACKNOWLEDGMENTS This work was supported in part by Mori Seiki, the Digital Technology Laboratory (DTL), the Machine Tool Technologies Research Foundation (MTTRF), Kennametal, and other industrial partners of the Laboratory for Manufacturing and Sustainability (LMAS). The authors would like to thank the UC Berkeley Mechanical Engineering Department’s Student Machine Shop for providing valuable insight and advice . For more information, please visit . 7 REFERENCES [1] Diaz, N.。 Energy Consumption Reduction。 Energy Consumption Reduction。 廣西科技大學（籌）畢業(yè)設計（論文）外文翻譯課題名稱 汽車上油殼加工工藝及夾具設計 系 別 職業(yè)技術教育學院 專 業(yè) 機械工程及自動化 班 級 機自Z081 學 號 200802201022 姓 名 何 仕 指導教師 鄧 麗 萍 Laboratory for Manufacturing andSustainabilityUC BerkeleyTitle:Energy Consumption Characterization and Reduction Strategies for Milling Machine Tool UseAuthor:Diaz, Nancy, University of California, BerkeleyDornfeld, David, UC BerkeleyPublication Date:05042011Series:Green Manufacturing and Sustainable Manufacturing PartnershipPublication Info:Green Manufacturing and Sustainable Manufacturing Partnership, Laboratory for Manufacturingand Sustainability, UC BerkeleyPermalink:Keywords:Green Machine Tools。 Specific Energy CharacterizationAbstract:Since machine tools are used extensively throughout their functional life and consequently consuming valuable natural resources and emitting harmful pollutants during this time, this study reviews strategies for characterizing and reducing the energy consumption of milling machine tools during their use. The power demanded by a micromachining center while cutting low carbon steel under varied material removal rates was measured to model the specific energy of the machine tool. Thereafter the power demanded was studied for cutting aluminum and polycarbonate work pieces for the purpose of paring the difference in cutting power demand relative to that of steel. eScholarship provides open access, scholarly publishing services to the University of California and delivers a dynamic research platform to scholars worldwide.Energy Consumption Characterization and Reduction Strategies for Milling Machine Tool Use Nancy Diaz，Elena Redelsheimer，David Dornfeld，Laboratory for Manufacturing and Sustainability，University of California at Berkeley, USAAbstract Since machine tools are used extensively throughout their functional life and consequently consuming valuable natural resources and emitting harmful pollutants during this time, this study reviews strategies for characterizing and reducing the energy consumption of milling machine tools during t heir use. The power demanded by a micromachining center while cutting low carbon steel under varied material removal rates was measured to model the specific energy of the machine tool. Thereafter the power demanded was studied for cutting aluminum and polycarb onate work pieces for the purpose of paring the difference in cutting power demand relative to that of steel. Keywords: Green Machine Tools。Specific Energy Characterization1 INTRODUCTION A product undergoes three lifecycle stages: manufacturing, use and endoflife. Consumer products whose environmental impact is dominated by the use phase include light fixtures, puters, refrigerators, and vehicles, in general products that are used extensively during their functional life. All the while these products consume resources, in particular energy in the form of electricity or fuel. The machine tool is one such product. The use phase of milling machine tools has been found to prise between 60 and 90% of CO2equivalent emissions during its life cycle [1]. This study presents a method for predicting the electrical energy consumed in manufacturing a product for the purpose of reducing its environmental impact. In conducting a life cycle assessment, product designers may choose to opt for a process, economic inputoutput (EIO), or hybrid approach. The drawback of the process LCA, though, is that because this method entails acquiring processspecific data it is time consuming and therefore resource intensive. An alternative to measuring the machine tool’s electrical energy consumption directly, for example, is to use aggregate data as is done with EIOLCA [2]. An EIOLCA, therefore, is not specific to the design of a particular product. The strategies presented herein provide a method for more quickly generating manufacturing energy consumption estimates for a particular product. Cutting load profile As described by Diaz et al