C6132A1机床再制造实践

针对我国量大面广的中小型传统机床报废后的资源化处理问题,提出了基于废旧机床再利用的机床再制造模式。以典型传统机床C6132A1为例,从再制造工艺流程、再制造方案设计及再制造性能对比分析3个方面展开再制造研究。研究结果表明:再制造一台C6132A1机床平均消耗的钢材为100kg,仅为新品制造的1/22,可减少CO2排放2.52 t,大大节约了资源和能源,减少了环境排放。此外,再制造后机床的信息化程度大幅提升,不仅达到新品的性能水平,部分精度指标甚至超过新品。研究成果可为机床制造厂实施中小型传统机床的再制造提供理论基础和技术支持。     

LNG重型商用车和柴油重型商用车全生命周期环境排放差异评价

基于生命周期评价理论建立了液化天然气(liquified natural gas, LNG)重型商用车与柴油重型商用车的生命周期环境排放差异评价模型。通过实证分析,LNG搅拌车和柴油搅拌车相比,NOx排放量减少了32.83%,SOx排放量减少了83.68%,PM排放量减少了100%;而CO排放量却增加了21.39%,HC排放量增加了7.83倍。在CO2排放方面,使用阶段LNG搅拌车的排放量比柴油搅拌车减少了6.82%,全生命周期LNG搅拌车的排放量比柴油搅拌车减少了8.88%。     

喷射参数对点燃式重油直喷发动机小负荷性能的影响

在一台采用低压空气辅助喷射技术的二冲程点燃式重油直喷发动机上,进行了燃油喷射参数对发动机性能影响的试验研究,研究了中等转速小负荷工况下,喷气结束时刻及过量空气系数对发动机动力性、燃油经济性及排放性能的影响。试验结果表明:节气门开度为10%时,随着喷气结束时刻提前,功率先增大后减小,油耗先减小后增加,HC及CO排放有小幅度减少;混合气由浓变稀时,功率增加,油耗降低,HC及CO排放大幅度减少。节气门开度为20%时,随着喷气结束时刻提前,功率增大,油耗减小,HC排放有小幅度减少,CO排放有小幅度增加;混合气由浓变稀时,油耗降低,HC及CO排放大幅度减少,最大功率出现在理论空燃比附近。     

生命周期评价中的时间折扣研究

生命周期评价(Life Cycle Assessment,LCA)是评价产品生命周期环境影响和资源消耗的有效工具。但是现行的LCA并没有考虑清单数据的时间差异,导致了生命周期影响评价结果的不准确性。研究了LCA中的时间差异和生命周期排放模式,引入生命周期平均排放速率函数,以连续排放的模式代替现有研究的脉冲排放模式。在此基础上运用一级衰减模型建立了LCA中的时间折扣计算方法。最后,以国内某企业生产的洗碗机产品进行实例研究,说明LCA时间折扣的应用,表明应用时间折扣方法后CO2排放的变化。     

考虑回收利用过程的汽车产品全生命周期评价

构建了汽车产品全生命周期材料、能耗、排放评价模型,该模型涵盖汽车产品从材料获取、材料加工、零部件加工制造、整车装配、运行使用直至回收利用的生命周期闭环全过程。运用该评价模型,对某公司生产的传统汽油车和在该同一平台上开发的纯电动汽车进行实证分析,结果表明：纯电动汽车的全生命周期能耗及全生命周期CO2、CH4、N2O、NMVOC排放低于传统汽油车,但CO、SOx、NOx和PM排放均高于传统汽油车。采用CML 2001模型进行了两款车的全生命周期影响评价,结果显示：使用稀缺金属铜、锂较多的纯电动汽车在不可再生资源消耗（ADP）方面显著高于传统汽油车;纯电动汽车产生的温室效应（GWP）优于传统汽油车,但在人体健康损害影响、光化学烟雾影响及酸化影响方面,纯电动汽车均劣于传统汽油车。     

汽车发动机可再制造性评价

在产品可装配性评估方法和模型的基础上发展了产品可再制造性评价模型，在收集大量数据和试验的基础上，利用产品可再制造性评价模型模型对某型发动机可再制造性进行了系统的研究和评价。模型包括技术性和经济性两大模块。技术性模块用来评价产品可再制造在技术上的可行性和可行度，经济性用来评价再制造在经济上是否可行，两者相乘得到可再制造性指数。评价结果表明，汽车发动机具有良好的可再制造性。     

柴油机:降耗、减排都不能少

二氧化碳(CO2)排放对全球变暖的影响正日益引起各国政府的重视,为此,整个汽车工程技术界正在竭力寻找和尝试满足未来汽车排放要求的方法和技术。幸运的是,除了单纯依靠降低油耗以外,降低CO2排放的要求还可以依靠其他技术来进行,如降低气态污染物和颗粒排放,提高发动机耐久性和可靠性等。作为交通运输能源的主要消耗者之一,减少商用车的CO2排放对于减少对环境污染的目标实施具有重要意义。     

对15工况法中汽车排放特性的研究

根据15工况法对汽车的排放特性进行试验研究．给出了CO、HC、NOx的排放特性曲线，对工况法中发动机输出扭矩、功率和有害气体排放成分的关系进行了探讨，为改善发动机的排放特性提供了依据。     

配合工业需要的冲压新材料、新技术

在汽车行业，75％的能耗直接与车重有关。汽车自重每减少1130kg，百公里油耗就可减少0．7L；每有两磅铁合金披一磅铝合金替代，汽车终身CO2类排放就会减少9．07kg（20磅）。因此，以高强钢、铝合金、镁合金及多种复合材料为代表的轻质、高强度难成形材料在汽车、航空航天器等先进制造领域的应用日益增加，结构轻量化和材料轻量化业已成为科学技术研究的热点。     

再制造产品服务系统生命周期评价建模及应用

基于再制造和产品服务系统的特征提出了再制造产品服务系统(RPSS)的概念,根据生命周期评价(LCA)方法框架建立了RPSS LCA模型,并以柴油发动机RPSS为案例对模型开展应用研究。研究发现,确保再制造产品质量和性能不低于新品,避免产品使用过程消耗大于新品是企业通过实施RPSS获得环境效益的关键;企业开展面向再制造的产品设计,提高产品再制造率,可以降低RPSS生命周期环境影响;RPSS可以为企业提供稳定的旧件来源,提高企业市场竞争力。     

[产品服务系统]再制造产品服务系统生命周期评价建模及应用

基于再制造和产品服务系统的特征提出了再制造产品服务系统（RPSS）的概念,根据生命周期评价（LCA）方法框架建立了RPSS LCA模型,并以柴油发动机RPSS为案例对模型开展应用研究。研究发现,确保再制造产品质量和性能不低于新品,避免产品使用过程消耗大于新品是企业通过实施RPSS获得环境效益的关键;企业开展面向再制造的产品设计,提高产品再制造率,可以降低RPSS生命周期环境影响;RPSS可以为企业提供稳定的旧件来源,提高企业市场竞争力。     

New approach for robust multi-objective optimization of turning parameters using probabilistic genetic algorithm

Limited by techniques, the process of remanufacturing exists masses of uncertainties which have a great impact on the remanufactured parts quality, how to achieve a higher quality of mechanical products by using limited remanufactured parts precision, has become one of the key issues of remanufacturing industry. Firstly, with a target to reduce uncertainties and improve the quality of automatic products, a method of tolerance grading allocation for remanufactured parts is proposed based on the uncertainty analysis of the remanufacturing assembly. The dimensional tolerances of the mechanical parts are divided into positive and negative two groups. We use selective assembly method to reduce assembling deviation. Then, the method is proven by mathematical formulas that the remanufactured parts variance can be expanded to two times, and the tolerances can be liberalized 40 % through tolerance grading allocation method. It is also the theoretical basis for improving the reuse radio and quantitatively describing the tolerance liberalization in this paper. Finally, feasibility research on this method is studied from the angle of cost–benefit. Furthermore, a tolerance grading allocation example of remanufactured engine piston assembly in a power corporation shows the validity and practicality of the proposed method.     

中国特色的再制造零件质量保证技术体系现状及展望

再制造在实现资源能源节约的条件下生产出经济发展所需要的产品,是建设资源节约型、环境友好型社会的有效途径针对中国特色的再制造模式,结合再制造产品及其生产环节,分析影响再制造零件质量的主要因素,指出为保证再制造零件质量应把控的几个环节,即再制造毛坯质量评价、再制造生产过程监测、再制造零件/涂层质量检验,并提出再制造零件质量保证技术体系,介绍我国近几年在再制造标准方面的主要成绩,并指出为适应我国再制造产业快速发展需要,急需加强再制造成形技术方法和再制造质量检测评价方法等方法标准的研究。阐述再制造毛坯和再制造涂层质量无损监/检测评价方法,并结合车辆发动机典型零件再制造实践,介绍无损检测评价技术在再制造质量保证中的应用。展望中国特色再制造零件质量保证技术的未来发展。     

A proposed mathematical model for closed-loop network configuration based on product life cycle

Products may be returned over their life cycle. Industrial experiences show that there are three main return–recovery pairs. Commercial returns are repaired. End-of-use returns often are remanufactured. In addition, end-of-life returns are recycled. However, up to now, no optimization model is proposed for closed-loop configuration based on three return–recovery pairs. The repaired and remanufactured products can be sold in the same or secondary market. In this paper, we design and configure a general closed-loop supply chain network based on product life cycle. The network includes a manufacturer, collection, repair, disassembly, recycling, and disposal sites. The returned products are collected in a collection site. Commercial returns go to a repair site. End-of-use and end-of-life returns are disassembled. Then, end-of-life returns are recycled. The manufacturer uses recycled and end-of-use parts and new parts to manufacture new products. The new parts are purchased from external suppliers. A mixed-integer linear programming model is proposed to configure the network. The objective is to maximize profit by determining quantity of parts and products in the network. We also extend the model for the condition that the remanufactured products are sent to the secondary market. The mathematical models are validated through computational testing and sensitivity analysis.     

FATIGUE LIFE PREDICTION OF CRANKSHAFT MADE OF MATERIAL 48MnV BASED ON FATIGUE TESTS,DYNAMIC SIMULATION AND FEA

S-N curve and fatigue parameters of 48MnV are obtained using small sample tests and staircase or up and down method, which paves the way for predicting fatigue life of crankshaft made of 48MnV. The fatigue life of the crankshaft of a six-cylinder engine is calculated using different damage models such as S-N method, normal strain approach, Smoth-Watson-Topper (SWT)-Bannantine approach, shear strain approach, and Fatemi-Socie method based on dynamic simulation and finite element analysis (FEA) of crankshaft. The results indicate that the traditional calculation is conservative and the residual fatigue life of crankshaft is sufficient to maintain next life cycle if the crankshaft is remanufactured after its end of life.     

[绿色设计]面向2020年的质子交换膜燃料电池汽车生命周期评价及预测

运用GaBi软件建模，以我国燃料电池技术2020年发展目标为基础，结合美国能源部2020年燃料电池汽车技术计划，对2020年我国燃料电池汽车的全生命周期节能减排绩效进行定量评价计算和预测分析。结果表明：2020年我国每台燃料电池汽车全生命周期平均矿产资源消耗量EADP(e)、化石能源消耗量FADP(f)和温室气体排放量QGWP分别为0.609 kg（锑当量）、3.99×105 MJ以及2.99×104 kg（CO2当量）。从其全生命周期来看，EADP(e)、FADP(f)与原材料获取阶段贵金属铂的生产、制氢技术以及燃料电池的效率有关，QGWP则主要来源于制氢过程中消耗的化石燃料和电能。降低燃料电池汽车对资源环境影响的有效措施有：加快研发关键材料及金属铂的高效回收策略，从而不断降低贵金属的消耗量；改进制氢技术，由化石能源主导变为可再生清洁能源主导；逐步优化电力结构，有效降低氢气压缩过程中的煤电消耗量等。     

不同技术路线Warp Air Clean材料对机动车尾气减排效果研究

传统机动车尾气减排技术经过长期发展,取得了较好效果,但在短期难以获得更大的突破.Warp Air Clean(WAC)技术通过对发动机的进气进行净化,提高发动机内燃烧效率,从而减少尾气排放,是解决机动车尾气排放的新途径.本研究对比了四种不同合成方案WAC材料的减排效果,为该技术的进一步完善优化提供了基础.研究发现:采用...     

COMPOSITIVE EMISSION CONTROL SYSTEM OF GASOLINE VEHICLE

The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation (EGR), thermal reactor and catalytic converter, etc. The purification effect of CO, HC and NOx emission of the gasoline spark ignite (S.I.) engine is studied. The entire vehicle driving cycle tests based on the national emission standard and a series of the gasoline engine-testing bench tests including full load characteristic experiment, load characteristic experiment and idle speed experiment are done. The results show that the system has a very good emission control effect to CO, HC and NOx of gasoline engine. The construction of the system is very simple and can be mounted on the exhaust pipe conveniently without any alteration of the vehicle-use gasoline engine.     

面向再制造复杂机械产品装配过程的质量控制点公差带在线优化方法

为提高再制造零部件利用率并提升再制造复杂机械产品的装配精度,提出了一种面向再制造复杂机械产品装配过程的质量控制点公差带在线优化方法。在分析再制造复杂机械产品装配特点的基础上,对关键工序的质量控制点公差带进行细粒度划分;从装配精度角度出发,综合考虑装配过程中的质量损失和成本差异,以尺寸链为约束,构建了公差带优化模型,并研究了基于遗传算法的模型求解过程;在此基础上,提出了基于历史数据的正向推理模式,以及基于装配实时信息的逆向推理模式,推导出装配优化方案集并对车间异常情况作出及时响应;最后,开发出再制造发动机装配过程在线质量控制系统原型,验证了该方法的可行性和有效性。     

The online quality control methods for the assembling of remanufactured engines’ cylinder block and cover under uncertainty

The assembling of cylinder block and cover is one of the keys for the quality controlling of remanufactured engines. First, we analyze the critical factors which influence the assembly quality and study the uncertainty connotation of the flatness and roughness of cylinder block and cover, as well as bolts. Then, an uncertainty quantitative measure model for each factor has been structured, and according to that, we proposed a back propagation (BP) neural network-based quality control method which can achieve self-learning, updating, and online dynamic quality controlling. It can reduce the negative effects caused by the uncertainty and improve the assembly accuracy. Finally, the quality data of remanufactured engine in 2012 proves that the method can improve the qualification rate of 0.63 % and reduce the cost of after-sales claims by 35.2 %; the living examples verify its feasibility and validity.