外文翻译----CADCAECAM集成系统在压铸模具中的应用.docx

附 录a 外文文献及译文application of an integrated cad/cae/cam system for die casting diesabstract according to the concept of concurrent engineering (ce), a cad/cae/cam integrated system for die casting dies is established and applied in the primary stage. the platform of the pro/engineer cad/cam software, the magmasoft simulation software and a primary expert system for the design of the die casting process are available to establish this integrated system. a primary expert system package including a series of empirical calculation equations and data for the design of technological scheme and dies of die casting has been developed by the authors. this integrated system has been applied successfully in the design and manufacture of die casting dies for aluminum and magnesium die castings, such as the water pump of the santana sedan. the use of this integrated system can shorten the cycle of die design and manufacture, and result in the production of high quality die castings in a shorter time. the lead-time of die castings is shortened greatly.keywords: cad/cae/cam integrated system; die casting dies; numerical simulation of metal flow and solidification1. introductionthe application of die castings is expanding continuously. the construction of die castings is becoming more complex and large-sized, and at the same time a shorter development cycle of new die casting products is required. how to produce high quality die castings in a shorter period with a lower cost has become an important and urgent task of die casting enterprises. recently concurrent engineering (ce) has been introduced into die casting production, and the cad/cae/cam integrated system of die casting dies has been established 1. in the ce process, the first step is to create a 3d part database for use in all aspects of the production process. the next step is to design the die casting process, which includes the design of gating system, overflows and cooling channels and whole set of die casting dies. in order to avoid the defects in the casting, by means of the casting simulation software the numerical simulation of metal flow and solidification in the dies, i.e. the cae, is performed. the database also provides the data which are needed in the generation of the cavity roughing and finishing cnc programs for die manufacturing by cam, and is connected to the coordinate measuring machines (cmms) for measuring 1,2. due to the use of a unitary database of 3d model in the whole period, all these steps can be performed simulta-neously. the lead-time and whole cycle of design and manufacture can be shortened greatly 2. therefore, die casters have paid more and more attention to the cad/cae/cam integrated system of dies, which embodies the ce concepts of modern advanced manufacturing technique.2. establishment of the cad/cae/cam integrated system for die casting dies the general scheme of cad/cae/cam integrated system of die casting dies is shown as fig. 1. a cad/cam software, a cae simulation software and a die casting expert system are included in it. due to the complex shape of die castings, the large-scale cad/cam software is required for the 3d solid modeling and manufacturing. now the widely used cad/cam software are pro/engineer cad/cam software of ptc, unigraphics ii cad/cam software of eds, and ideas cad/cam software of sdrc, usa. the principle of cae simulation of castings is based on the solving of the equations in fluid dynamics and heat transfer (such as the continuity equation, the navierstokes equation and the fourier equation, etc.) by means of finite difference method (fdm) or finite element method (fem). the velocity profile of the metal flow in the die cavity and the temperature distribution of the casting and die during the filling and solidification process can be obtained by calculation. then the metal flow and solidification of die castings are simulated with the use of cae simulation software. the casting simulation software packages now available are cap of ekk, flow-3d of flow science, pro/cast of ues, usa, and magmasoft of magma, germany, etc. 3. in this paper the platform of the pro/engineer cad/cam software, the magmasoft simulation software, and a primary expert system for the design of die casting process are used to establish the cad/cae/cam integrated system of die casting dies, this system is applied for the die castings of a water pump of aluminum alloy and a housing cover of magnesium alloy 4,5.3. application of the cad/cae/cam integrated system for die casting dies3.1. cad modeling and design of technological scheme and dies first the 3d solid modeling of a part is created, then the 3d modeling of the die casting including the information of machining allowance, shrinkage and taper is formed by using the pro/engineer cad/cam software (shown as fig. 2). the data of machining allowance, shrinkage and taper are chosen from database ii in accordance with the accuracy and surface rating of the parts, the structure of the parts and the type of alloy. by means of a primary expert system package for the design of the technological scheme of die casting process, which was developed by the authors, the process parameters of die casting such as the injection pressure, plunger speed, gate velocity and filling time, etc. are selected suitably, and checked by empirical calculation equations in accordance with the type of alloy, and the wall thickness and structure of the casting. the technological scheme of die casting process including the gating system, overflows and cooling channels is also designed, and the projected area of the cavity and the thermal balance of dies are calculated and checked. then the die casting machine is selected. in database i are stored the information of various normalized component parts of dies and some empirical data of die design such as the thickness of inlays, the distance from the cavity to the outer surface of the die, etc. with the use of database i in the expert system, finally the 3d solid modeling of the whole set of die casting dies, including cover and ejector moulds, cores, gating system, overflows and cooling channels, etc. are all completed (shown in fig. 3). then all these modeling data are translated into data files. the shape of the die casting of the water pump is comparatively complex. it includes an involute outline, a groove with varied height, a distorted transition region connecting different transverse sections with a sphere-like arch, etc. all these are difficult for modeling.3.2. cae simulation and analysis the die casting of water pump is produced in an ip 550 horizontal die casting machine. there are two types of defects occurring in this casting: air holes and porosity. the metal flow and solidification in the dies is simulated with the use of magmasoft software. the simulation results of several technological scheme are analyzed. the problems occurring in the metal flow and solidification can be observed directly through the simulation. in the original scheme the gating system of the water pump causes the splash of liquid metal and air entrapment during filling (shown in fig. 4). this results in the occurrence of air holes and oxide inclusions. then the design of the gating system is revised and the process parameters are also regulated, which reduces these defects notably (shown in fig. 5). in addition, the original scheme often leads to porosity at the hot spot of die castings (shown in fig. 6). therefore, in the revised scheme the transition point from the slow shot to plunger acceleration is adjusted suitably, and the pressure build-up time is also shortened, in order that the high pressure can be transferred to the liquid metal at the hot spots in time before the gate solidifies. thus, the defects of porosity are basically eliminated. the complex shape of the water pump casting and its wall unevenness make the defects of porosity and air entrapment easy to occur, but the demand for the sealing of a die casting of a water pump is very high, and the casting has to pass through a hydraulic pressure test without any leakage. the design of the die casting process is optimized with the help of cae simulation and analysis, and the percentage of qualified products of die casting is raised greatly in a shorter time.3.3. the realization of cam on the basis of the data of the 3d solid modeling of the cavities of die casting dies, with the use of the pro/manufacturing module of the pro/engineer cad/cam software, the 3d solid modeling of blank figures of the inlays are created first. then the operation table of the machining including the machining parameters, cutters, cutter path, etc. is listed, and the nc (numerical control) cutting procedures and the cl (cutter locate) data files are also created. furthermore due to the use of the module of an nc-check, the cutter path in machining is checked and the instantaneous machining process can be visualized. the cl data file of each nc cutting procedure is revised until a satisfactory result is reached. the cam is realized as soon as these data files are post-processed and transferred into the nc machine code. the cutter path in the machining of the inlay of die casting dies of housing cover is shown in fig. 7.4. results of the application of integrated system as mentioned above, with the help of the pro/engineer cad/cam software and a primary expert system package, the 3d solid modeling of die casting and the design of technological scheme of die casting process are created. next the simulation and analysis of metal flow and solidification in dies are performed with the use of the magmasoft software; the technological scheme and process parameters of die casting are also revised and optimized. then the 3d solid modeling of whole set of dies is completed. finally the cam machining data of the complex surface of moulds and cores are created, and the cam of whole set of dies are completed on the cnc machines. due to the use of a unitary database of the 3d model over the whole period, some steps may be performed simultaneously, and the design and manufacturing cycle of the dies can be shortened obviously. the technological scheme and process parameters of die casting process are revised and further optimized by using the cae simulation, and the quality of the die castings improved greatly in a shorter time. for example, due to the use of cae simulation, the percentage of qualified products of die castings of the above-mentioned water pump is raised from 60 to 90% in a shorter time. another example is a magnesium die casting of a gearbox housing of a sedan. the cae simulation results show the unevenness of the temperature distribution in the die cavity. the thermal balance and temperature distribution of the dies are improved with the regulation of process parameters such as gate velocity, flow rates of cooling media, etc. and the occurrence of cracks is reduced greatly. because the percentage of qualified products of die castings can be raised greatly in a shorter time, the whole lead-time of die castings is also shortened greatly.5. conclusions the established cad/cae/cam integrated system of die casting dies has been used successfully in the design and manufacture of die casting dies of sedan parts such as a water pump, a gearbox housing, etc. the cycle of design and manufacture of die casting dies are shortened obviously. the process parameters and technological scheme of die castings can be optimized with the help of cae simulation. this results in the production of die castings of consistently high quality in a shorter time, and the lead-time is shortened greatly. however, further research and development has to be undertaken for this integrated system, especially for the part of the expert system. more cases of die castings that are produced successfully in production have to be analyzed, and their information will be also included in the expert system. this will help to perfect the expert system.references1 k. chipley, s. viswanathan, r.h. cooper, die cast. eng. 40 (2) (1996) 1826.2 p.m. bralower, die cast. eng. 42 (5) (1998) 1620.3 s.p. midson, die cast. eng. 38 (5) (1994) 4246.4 s. yue, g. dai, foundry eng.-molding mater. 22 (12) (1998) 813.5 shuhua, yue, j. yu, h. sun, et al., foundry 46 (1) (1997) 1418. cad/cae/cam集成系统在压铸模具中的应用摘 要 根据并行工程（ce认证）的概念，cad/cae/cam集成系统目前已在压铸模具设计中得到建立和初级阶段的应用。pro/engineer中的cad/cam软件， magmasoft仿真软件，和一个可以为压铸设计建立压铸模具cad/cae/cam集成系统的专业系统。软件公司已开发出一种重要的压铸模具专业软件系统包，它提供了模具和方案设计中的一系列经验计算公式和数据。这种集成系统已成功应用于铝、镁压铸件的模具设计和制造，如桑塔纳汽车的油泵。使用这个集成系统，可以缩短模具设计和制造周期，并在较短的时间里，生产出高质量的压铸件。压铸件的交货时间也大大缩短。关键词：cad/cae/cam集成系统、压铸模具、金属流动和凝固的数值模拟1、介绍 压铸件的应用正在不断扩大。压铸件的结构正变得越来越复杂化和大型化，同时，一个新的压铸产品的开发周期要求更短。如何在较短的时期里用较低的成本生产出高质量的压铸件已成为压铸企业一项重要而紧迫的任务。最近并行工程（ ce ）已引入压铸生产工艺，并且已经建立了压铸模具cad/cae/cam集成系统1。在并行工艺过程中，第一步是创建零件生产过程中所用到的所有方面3d数据库。第二步是设计压铸工艺中的浇注系统，溢出和冷却通道，以及压铸模具的整体框架。为了避免铸造中的一些缺陷，可以应用铸造模拟软件里的cae技术对铸造过程模具中的金属的流动和凝固进行数值模拟。该数据库还提供了cam模具制造过程中cnc程序对腔的粗加工和精加工所需的数据，还连接了坐标测量机（cmm）应用于测量 1,2。由于在整个过程中使用的是同一三维模型的数据库，以上这些步骤可以同时进行。交货的时间和整体的设计与制造周期可以大大缩短2。因此，模具设计者对模具的cad/cae/cam集成系统的越来越多的关注，体现了现代先进制造技术的ce技术的重要性越来越大。2、cad/cae/cam集成系统在压铸模具中的建立 cad/cae/cam集成系统压铸模具的总体方案如图1所示。它包括一个cad/cam软件,一个cae仿真软件和一个压铸专业软件系统包。 由于压铸件形状复杂，需要大型的cad/cam软件的三维实体造型和制造。现在广泛使用的cad/cam软件是ptc公司的pro/engineer的cad/cam，eds公司的unigraphics ii的cad/cam，和美国ideas的cad/cam的软件。 铸件cae模拟技术原理的解决方法有：有限差分法（fdm）的流体动力学和传热方程（如连续性方程，navier-stokes方程和傅立叶方程等）或有限元法（fem）。金属液在模具型腔里的流动速度和铸件的温度分布以及金属液在模具中的填充和凝固过程可以通过计算得出。然后用cae模拟软件模拟压铸过程中金属液在模具中的流动和凝固过程。铸造模拟软件包现在可用的有ekk的cap，流体科学的flow-3d，美国ues的pro/cast，以及德国的magmasoft等3 。 本论文使用的是pro/engineer的cad/cam软件，magmasoft仿真软件，和一个可以为压铸工艺设计建立压铸模具cad/cae/cam集成系统的专业系统，这个系统应用于铝合金油泵压铸件和镁合金的外壳盖4,5。3、cad/cae/cam集成系统在压铸模具中的应用3.1、模具的cad建模和设计的技术方案首先新建零件的三维实体造型，然后通过使用pro/engineer的cad/cam软件进行压铸件的三维建模，建模的内容有铸件的加工余量，收缩率和锥度的形成（如图2所示）。铸件的加工余量，收缩率和锥度大小的数据是根据零件的表面精度等级、零件的结构和合金类型从数据库ii中选择。通过由软件商开发的一款重要的专业软件系统包进行压铸工艺技术方案的设计，可以对压铸模的工艺参数，如注射压力、柱塞速度、注射速度和充填时间进行适当的选择，根据合金类型的经验计算公式，可以对压铸件的壁厚和结构进行校核。该设计方案还包括浇注系统，溢出和冷却通道的工艺设计，以及型腔的内表面积和模具的热平衡的计算和校核。然后选择压铸机。在数据库i中存储了各种标准零部件的数据和模具设计的经验数据，如镶嵌的厚度，型腔内表面到模具外表面的距离等一些经验数据，随着该专业软件系统数据库i的使用，该压铸模完整的三维实体造型终于全部完成，包括外表面和喷射机构，型芯，浇注系统，溢出和冷却通道等（如图3所示） 。然后把所有模拟数据转换成数据文件。 压铸件油泵的形状是比较复杂的。它包括一个渐开线轮廓，具有不同高度的槽，弯曲的过渡区域连接着不同横截面的球体状拱，所有这些都给建模造成很大麻烦。3.2、cae模拟及分析压铸件油泵的生产使用的是ip 550卧式压铸机。在这个铸件生产中常出现的缺陷有两种类型：气孔和缩孔。该模具中金属的流动和凝固的模拟使用的是magmasoft软件。然后对几种技术方案的模拟结果进行分析。通过模拟可以清楚地看出金属流动和凝固过程中出现的问题。在充填金属液的过程中使用传统的浇注系统进行浇注将会导致金属液的飞溅和空气不能及时排出。这将会出现气孔和氧化夹杂物等缺陷（如图4所示）。为了减轻这种缺陷