Minimizing manufacturing costs for thin injection molded plastic components

Minimizing the cost of manufacturing a plastic component is very important in the highly competitive plastic injection molding industry. The current approach of R&D work focuses on optimizing the dimensions of the plastic component, particularly in reducing the thickness of the component during product design, the first phase of manufacturing, in order to minimize the manufacturing cost. This approach treats the component dimensions established in the product design phase as the given input, and uses optimization techniques to reduce the manufacturing cost of mold design and molding for producing the component. In most cases, the current approach provides the correct solution for minimizing the manufacturing cost. However, when the approach is applied to a thin component, typically when miniaturizing products, it has problems finding the true minimum manufacturing cost. This paper analyses the shortcomings of the current approach for handling thin plastic components and proposes a method to overcome them. A worked example is used to illustrate the problems and compare the differences when using the current approach and the new method proposed in the paper.     

三基色原理在火工品温度场测试中的应用

随着微纳米结构含能药剂在火工品中的广泛应用,微尺度火工品逐渐朝着微型化方向发展。这对小尺寸条件下温度的测试提出了新的挑战。燃烧温度作为微尺度火工品输出性能的重要参数之一,对火工品输出能力评价具有重要意义。为了测量微尺度火工品燃烧温度场,根据三基色原理和普朗克定律建立三基色测温公式,搭建了一套由光学镜头、彩色相机、软件系统和计算机组成的测温系统。利用黑体炉对系统进行标定,建立温度与三基色值的关系,并对测量误差进行了分析与讨论。通过与红外热像仪测量结果对比,三基色测温法的准确性较高,两者测得的最高温度相差不超过1%,为微尺度火工品燃烧温度场的测量提供了思路。     

Micro electrical discharge machining using high electric resistance electrodes

In micro electrical discharge machining (EDM), because the material removal per single pulse discharge mainly determines the minimum machinable size of a micro EDM, decreasing the material removal per single pulse discharge is important. In this study, in order to decrease the material removal per single pulse discharge, high electric resistance materials such as single-crystal silicon are used for electrodes. Analytical results show that when the electrode resistance increases, the peak value of the discharge current decreases, whereas the pulse duration increases. In addition, the discharge energy decreases when increasing the resistance. Silicon is used as a tool electrode, and the effect of resistivity of the silicon tool electrode on the diameter of discharge craters generated on the stainless steel workpiece is examined. Experimental results reveal that with increasing silicon electrode resistivity, the diameter of discharge craters decreases. Because the diameter of discharge craters can be decreased to 0.5 μm, improved finished surfaces of R_z 0.03 μm are obtained.     

一种小型智能光纤温控仪系统

介绍一种以微控制器、可编程外围芯片为核心构成的数字化、小型化光纤传感智能温控仪系统。该系统配置灵活且实现非接触式测温;具有通信接口,可与过程控制网络连接,支持流行的现场总线协议。     

On the ultra-miniaturization of concentrator solar cells

The trend of cell miniaturization in concentrator photovoltaics (CPV) - currently in mm-scale and motivated by efficiency improvements linked to reduced series resistance - begs the question whether fundamental energetic considerations limit ultra-miniaturization. Mitigating factors subsume the busbars and metallization grid, the contributions of which embody subtle tradeoffs and vary non-trivially as cell size is reduced - evaluated via a distributed circuit simulation model, with some supporting experimental evidence. Concurrently, the influence of cell size on how metal grid design can lower series resistance is assessed, prompted by micro-concentrators that completely eliminate grid shadowing and allow far greater metallization coverage.     

变压吸附制氧机微型化研究

探讨了变压吸附制氧机微型化的一般途径:使用分离性能好的分子筛,以减小制氧机的体积与重量;在工艺流程中增加均压步骤,以降低能耗,减小体积;优化吸附塔结构,以降低其高度;将双塔结构改为多塔结构,可以很大程度地降低制氧机的高度;把制氧机做成分体式,将其从室内移到室外,以达到室内“零”体积。降低产品气纯度标准,使其仅用于氧保健领域,也是微型化研究的方向。     

天线控制子系统小型化浅淡

小型化武器具有重量轻、体积小、造价低、不易被发现和摧毁等特点 ,在未来战场上有着强劲的发展前景和潜力。重点介绍了飞机天线控制子系统的小型化做法 ,并结合实际工程应用 ,进行简介和论述     

Micro technology in heat pumping systems

Micro heat pumps, with dimensions in the order of centimetres, may in the future be utilised for the heating and/or cooling of buildings, vehicles, clothing, and other products or applications. A number of issues have yet to be solved, including the construction of a microscale compressor, and determination of micro heat exchanger heat transfer capacities. Test samples of micro heat exchangers and a corresponding test apparatus have been built. Some two-phase experiments with propane (R-290) as refrigerant have been conducted. Preliminary results for a micro condenser with 0.5 mm wide trapezoidal channels of 25 mm length showed that a heat flux of up to 135 kW/m², based on the refrigerant-side area, was attainable. The corresponding overall heat transfer coefficient was 10 kW/(m² K), with a refrigerant mass flux of 165 kg/(m² s) and a refrigerant-side pressure drop of 180 kPa/m.     

一种新型铠装式空气绝缘金属封闭开关柜

介绍一种新型的高可靠性小型化开关柜,包括主要技术参数、设计、试验情况等。根据其结构特点,对主要应用场合进行说明。     

铷原子频标物理系统小型化设计

介绍了一种用于铷原子频标的小型化物理系统。该物理系统采用了开槽管式微波腔和分离滤光设计方案,体积为30 cm³。对该物理系统进行了初步测试,短期频率稳定度为3.8×10^-12/τ^1/2,表明该物理系统同时具备了小型化和高信噪比特点,可以应用于高性能小型化铷原子频标。