1、PDF外文：http:/ Laboratory for Manufacturing and Sustainability UC Berkeley Title: Energy Consumption Characterization and Reduction Strategies for Milling Machine Tool Use Author: Diaz, Nancy, University of California, Berkeley Dornfeld, David, UC Berkeley Publication Date: 05-04-2011 Ser
2、ies: Green Manufacturing and Sustainable Manufacturing Partnership Publication Info: Green Manufacturing and Sustainable Manufacturing Partnership, Laboratory for Manufacturing and Sustainability, UC Berkeley Permalink: http:/escholarship.org/uc/item/40g995w6 Keywords: Green Machine Tools； Energy Co
3、nsumption Reduction； Specific Energy Characterization Abstract: 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 reduc
4、ing the energy consumption of milling machine tools during their use. The power demanded by a micro-machining 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
5、 aluminum and polycarbonate work pieces for the purpose of comparing the difference in cutting power demand relative to that of steel. &nbs
6、p; - 1 - eScholarship provides open access, scholarly publishing services to the University of California and delivers a dynamic research platform to sch
7、olars 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, USA Abstract Since machine
8、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 pow
9、er 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 comparing th
10、e difference in cutting power demand relative to that of steel. Keywords: Green Machine Tools； Energy Consumption Reduction；Specific Energy Characterization 1 INTRODUCTION A product undergoes three life-cycle stages: manufacturing, use and end-of-life. Consume
11、r products whose environmental impact is dominated by the use phase include light fixtures, computers, 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
12、 of electricity or fuel. The machine tool is one such product. The use phase of milling machine tools has been found to comprise between 60 and 90% of CO2-equivalent emissions during its life cycle 1. This study presents a method for predicting the electrical energy consumed in manufacturing a produ
13、ct for the purpose of reducing its environmental impact. In conducting a life cycle assessment, product designers may choose to opt for a process, economic input-output (EIO), or hybrid approach. The drawback of the process LCA, though, is that because this method entails acquiri
14、ng process-specific 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 EIO-LCA 2. An EIO-LCA, therefore, is not specific to the design of
15、a particular product. The strategies presented herein provide a method for more quickly generating manufacturing energy consumption estimates for a particular product. 1.1 Cutting load profile As described by Diaz et al. in 3 the power demand of a machine tool is comprised
16、of cutting, variable, and constant power components. The cutting power is the additional power drawn for the removal of material. The machine tool used in this analysis, the - 2 - Mori Seiki NV1500 DCG, is a micro-machining center with a relatively low standby power demand when com
17、pared to large machining centers. Therefore, the cutting power can comprise a large portion of the machine tool s total power demand. Energy consumption for high tare machine tools was found to be primarily dependent on the processing time of the part, which is dictated by the pa
18、rt geometry, tool path, and material removal rate. One such method for optimizing the tool path for minimum cycle time was presented in 4. This paper is concerned with the effect of the material removal rate on energy consumption. The material removal rate for a 3-axis machining
19、center can be varied by changing the feed rate, width of cut, or depth of cut. Since increasing the feed rate was found to have dire consequences on the cutting tool life 5, the experiments conducted herein varied material removal rate through width of cut and depth of cut experiments for the purpos
20、e of analyzing the material removal rate s effect on cutting power and more importantly, energy consumption. Although increases in the material removal rate translate to faster machining times, the loads on the spindle motor and axis drives increase as well, resulting in higher power demand. Since o
21、ur main interest is energy consumed in product manufacture, the trade-off between power demand and machining time was analyzed to confirm that the increased loads due to faster material removal was not increasing the total energy consumed. 2 POWER DEMAND FOR VARIED M.R.R. S
22、 Since machine tool programmers and operators have an array of options when defining the process plan for part production, this analysis strives to reduce energy consumption by process parameter selection of a machine tool. Specifically, the parameters concerning material removal rate (M.R.R.)
23、 were varied on a Mori Seiki NV1500 DCG while selecting appropriate tooling. The power demand was measured with a Wattnode MODBUS wattmeter. In previous work, experiments we re conducted in which spindle speed, feed rate, feed per tooth, and cutter type were varied to analyze the
24、 change in energy consumption while milling a low carbon steel, AISI 1018 steel 5. Also, 6 conducted experiments on face milling, end milling, and drilling operations in which the energy consumption, machining cost, and tool wear were compared for increased cutting speeds. Tool wear and, consequentl
25、y, cutting tool cost increased significantly when the process parameters veered away from the recommended cutting conditions. So in the following experiments the cutting tool type was changed to maintain the recommended process parameters, but reduce energy consumption while machining, nonetheless.
26、2.1 Width of Cut Experiments Given the energy savings from changing the cutter type this project focused on varying material removal rate. First the width of cut was increased while machining with a: 1. 2 flute uncoated carbide end mill, 2. 2 flute T
27、iN coated carbide end mill, and 3. 4 flute TiN coated carbide end mill. Peripheral cuts were made along the y-axis at a depth of cut of 2 mm with an 8 mm diameter end mill over a length of 101 mm in a 1018 steel work piece. The width of cut was varied by 1 mm increments between 1 mm and 7 mm, in addition to a 7.5 mm width of cut. Table 1 summarizes the cutting conditions used. The chip load was maintained at approximately 0.03 mm/tooth to avoid excessive tool wear and breakage.
