汽车活塞环行业的冷静思考与前景展望

活塞环行业是一个技术密集和劳动密集相结合的需要大投资的产业,活塞环与现代内燃机和汽车工业的发展息息相关,汽车活塞环行业随着我国整机行业的发展一样,赢来了快速增长,但是回顾发展历程,不得不让我们静下心来深深地思考。     

活塞环金相培训班试题

活塞环行业组最近在江苏溧水举办了一期金相培训班。学员来自全国活塞环主要生产厂,教员由行业组中具有丰富实践经验的工程师和专家担任。培训班时间短、投资少、见效快、结合实践为生产服务,为内燃机配件行业培养人才创出了一条新路。为了普及职工教育,本刊特将活塞环金相培训班结业试题选登出来,供同行业广大职工和科技人员学习,讨论。试题正确答案见下期。     

活塞环行业年会在甘肃定西召开

全国活塞环行业八六年年会,在机械工业部农机局领导下,在洛阳拖拉机研究所的大力帮助下,十二月十五日至十九日在甘肃定西召开,参加这次会议的代表来自全国活塞环行业成员厂、以及有关院校和活塞环专用设备制造厂家,四十二个单位七十三名代表,东道主地方公司领导到会指导。 会议主要内容:学术经验交流,改选行业组长厂和制定八七年行业活动计划。 会上石家庄内燃机配件总厂等单位的代表就他们在西德格茨;英国威尔沃西;日本理研等活塞环公司考察情况向与会代表作了介绍。 针对当前活塞环行业生产中出现的铸件质量、挠曲、漏光、制造工艺及机床改造等方面     

活塞环加工中的知识生产要素分析

文章对活塞环加工中的技术、信息和管理等知识生产要素进行了分析,提出了活塞环加工中基于知识生产要素的建议,列举了活塞环加工中重视知识生产要素的实例。文章认为,随着活塞环行业竞争格局的变化,知识生产要素在活塞环加工中的作用趋于增强。因此,国内活塞环企业必须更加重视知识生产要素,努力提升创新能力与企业竞争力,并在国际分工中得到可持续发展。     

全国活塞环行业电炉炉长培训班在南京市举办

全国活塞环行业电炉炉长培训班于一九八八年十月九日至十月三十一日在南京市举办。来自全国十五个省的近三十个工厂的电炉炉长、金相化验员、电炉技术管理工作者参加了学习。这期培训班聘请了上海内燃机研究所、江苏省仪征活塞环厂、上海内燃机配件总厂等在全国活塞环行业工作多年的专家和高级工程师任教。培训班开设了《活塞环的基础知识及熔炼用炉》、《金属学及合金铸铁活塞环的熔炼》、《活塞环的机械性能及金相和标准》等课程。学习期间,并组织学员先后到江苏省仪征活塞环厂、南京活塞环厂和金陵汽车制配厂参观学习。经过教师和学员们的辛勤努力,达到了预期的目的。学员们对江苏金陵汽车制配厂为培训班的举办给予的大力支持,以及提供学习参观创造条件表示衷心的感谢。     

发动机第一道环不同结构的设计应用

正0引言随着国内发动机行业的发展,整体零部件设计水平经过引进消化有大幅提高,国内主机厂家对新开发产品活塞环委托有设计能力的供方设计制造,在活塞环行业中形成了国内相应设计规范,提升了活塞环设计水平,国内资料对活塞环设计阐述较完善,现对发动机第一道环不同结构在设计中的应用     

活塞环热时效消除内应力工艺安排的质疑

本文简单介绍了采用电阻应变仪法测量活塞环残余应力的原理、方法及结果.从理论上分析了单体铸造活塞环极小的铸造应力与切削应力,对活塞环行业内铸坯经粗磨端面后时效的现行工艺安排提出了质疑,指出在活塞环工艺上作适当调整取消时效工序的可能性.     

活塞环自由形状曲线的确定

当前在活塞环制造行业中对活塞环自由形状确定,主要有热定型工艺及靠模凸轮加工,前者虽然工艺比较简单但其径向压力难以控制,难以满足进口发动机配件国产化中活塞环制造方面的要求,后者能根据不同条件设计成不同径向压力以满足不同发动机的要求。 本文根据多年实践体会提出:进口发动机活塞环配件国产化中、利用靠模凸轮、加工活塞环自由状态型线的步骤、与计算方法。     

镀铬活塞环宏观磨削裂纹浅析

本文从电镀、机加工以及活塞环的设计等方面系统分析了活塞环镀铬后磨削裂纹产生的机理与影响因素以及对工艺改善方面也提出相应技术途径,对活塞环实际生产过程中的质量控制有一定的借鉴与指导意义。     

活塞环行业年会在韶关召开

活塞环行业年会于11月25日至29日在广东韶关举行。出席这次大会的有全国活塞环行业成员厂和大学、研究所等37个单位55名代表。 大会主要内容: 一、交流经验:会上就活塞环加工工艺,检测设备,企业管理等发表了十二篇论     

二冲程分层扫气技术中美专利分析

本文分别从专利申请数量、涉及主要技术领域及主要专利申请人三个角度比对分析了二冲程分层扫气技术中美专利申请情况,并根据分析结果选取了典型专利进行分析。最终总结出二冲程分层扫气技术领域的中美研发现状,并对我国该领域的研发工作提出了合理化建议。     

Performance of a novel mechanical ventilation heat recovery heat pump system

The ventilation, heating and cooling of a building can be provided by advanced mechanical ventilation heat recovery systems (MVHR) which incorporate heat pumps. This paper covers the testing and performance of a novel MVHR heat pump system developed for the domestic market [S.B. Riffat, The University of Nottingham: Patent no. GB9522882.1, 1995; Patent no. GB9522882.1, 1996; Patent no. GB9507035.5, 1995]. The novel system uses revolving heat exchangers which both impel air and transfer heat. Low grade heat recovered from the exhaust air is upgraded by a heat pump and used for heating the fresh supply air. The system typically provides 2 kW of heating for air supplied at 250 m³/h. The prototype system has a heating coefficient of performance (COP) of up to 5 and an average system of COP 2.5 over a range of conditions. The system can also be used for cooling by switching the air flows over the evaporator and condenser. The prototype system requires very little maintenance and is compact and energy efficient.     

Study on the computation method of temperature field of RCC dam

According to the construction characteristic of RCC dam cast by layers, three-dimensional finite element relocating mesh method is developed to simulate construction process and compute temperature field. The computation model of relocating mesh method is expatiated in detail; based on the thermodynamic properties of RCC materials, the feasibility and error of relocating mesh method are analyzed and demonstrated; The computation results in this article are verified by means of the temperature observation data of certain RCC gravity dam. The results show that the temperature field computed by three-dimensional finite element relocating mesh method can not only ensure the computation precision, but also improve the calculation efficiency greatly. This provides an effective method for simulating construction process and computing temperature field of RCC dam.     

Pressure drop of the film-enlarged tube bundles in air-water two-phase cross flow in evaporative air cooler

An experiment was carried out to investigate the relation of the maximum velocity of air passing through narrowest passage, mass flux of spray water in one square meter in one hour and the pressure drop of tube bundles. Twelve equations were obtained for the relation. The results show that the pressure drop of the tube bundles increases with increase of the maximum velocity of air and the mass flux of spray water. Comparing the pressure drop of the bare tube bundles with that of the film-enhanced tube bundles, it is found that the pressure drop of the film-enhanced tube bundles is lower about 11% and the surface roughness of the film-enhanced plates is a main factor that influences the pressure drop. The data and method obtained in the paper can be used to compute the pressure drop of the film-enhanced tube bundles and is helpful for selection of fan.     

Simulation analysis of temperature control calculation of RCC gravity dam in the cold region

In this paper, regarding the actual conditions of a roller compacted concrete dam, three-dimensional finite element relocating mesh method is utilized to simulate and calculate the temperature field of the RCC dam during the construction stage and operating period. The calculation is well consistent with the actual construction process, the thin-layer pouring process the pouring temperature and all kinds of external loads involved being taken into account, By comparing and analyzing of the impact of the cold wave on the dam stress, important references are provided for the RCCD design and the temperature control during construction.     

Nonlinear parity space applied to an electric autonomous vehicle

The autonomous navigation of an electric vehicle requires the implementation of a number of sensors and actuators intended to inform it about his environment or his position and velocity and deliver necessary inputs. That＇s why it is important to detect and locate sensor and actuator faults as soon as possible to enable the operator to run the vehicle in degraded mode or use the fault tolerant control system if it exists. The main purpose of this paper deals with sensors or actuators faults diagnosis of autonomous vehicle. A diagnosis method using a nonlinear model of the vehicle is developed. Nonlinear state space model of the autonomous electric vehicle is used with the method of nonlinear analytical redundancy to detect and to isolate faults occurred on sensors or actuators. Computer simulations are carried out to verify the effectiveness of the method.     

A Hybrid Aluminum/Hydrogen/Air CellmCommon Cathode

Metal/Air batteries are considered to be promising electricity storage devices given their compactness, environmental benignity and affordability. As a commonly available metal, aluminum has received great attention since its first use as an anode in a battery. Its high specific energy （even better volumetric energy density than lithium） makes it ideal for many primary battery applications. However, the development of A1/Air cell with alkaline electrolyte has been lagged behind mainly due to the unfavorable parasitic hydrogen generation. Herein, we designed and constructed a novel A1/H_2/Air tandem fuel cell to turn the adverse parasitic reaction into a useful process. The system consists of two anodes, namely, aluminum and hydrogen, and one common air-breathing cathode. The aluminum acts as both the anode for the A1/Air sub-cell and the source to generate hydrogen for the hydrogen/air sub-cell. The aluminum/air sub-cell has an open circuit voltage of 1.45 V and the H_2/Air sub-cell of 0.95 V. We demonstrated that the maximum power output of aluminum as a fuel was largely enhanced by 31% after incorporating the H_2/Air sub-cell with the tandem concept. In addition, a passive design was utilized in our tandem system to eliminate the dependence on auxiliary pumping sub-systems so that the whole system remained neat and eliminated the dependence of energy consuming pumps or heaters which were typically applied in micro fuel cells.     

Measurement of the Energy Spectrum of the Neutrons inside the Neutron Flux Trap Assembled in the Center of the Reactor Core IPEN/MB-01

This paper presents the neutron energy spectrum in the central position of a neutron flux trap assembled in the core center of the research nuclear reactor IPEN/MB-01, obtained by an unfolding method. To this end, we have used several different types of activation foils （Au, Sc, Ti, Ni, and plates） which have been irradiated in the central position of the reactor core （setting number 203） at a reactor power level （64.57±2.91 watts）. The activation foils were counted by solid-state detector HPGe （high pure germanium detector） （gamma spectrometry）. The experimental data of nuclear reaction rates （saturated activity per target nucleus） and a neutron spectrum estimated by a reactor physics computer code are the main input data to get the most suitable neutron spectrum in the irradiation position obtained through SANDBP （spectrum analysis neutron detection code-version Budapest University） code： a neutron spectra unfolding code that uses an iterative adjustment method. the integral neutron flux, （2.41 ± 0.01） × 10^9 n·cm^-2·s^-1 for the thermal The adjustment resulted in （3.85 ± 0.14） × 10^9 n·cm^-2·s^-1 for neutron flux, （1.09 ±0.02） × 10^9n·cm^-2·s^-1 for intermediate neutron flux and （3.41 ± 0.02） × 10^8 n·cm^-2·s^-1 for the fast neutrons flux. These results can be used to verify and validate the nuclear reactor codes and its associated nuclear data libraries, besides, show how much effective it can be that the use of a neutron flux trap in the nuclear reactor core to increase the thermal neutron flux without increase the operation reactor power level. The thermal neutral flux increased 4.04 ± 0.21 times compared with the standard configuration of the reactor core.     

Optimal Simulation of Distributed Generation System for CO_2-Reduction in Supermarket and Restaurant

After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust heat is an important task to be solved. The purpose of this study is to build a simulation model to harness waste heat of commercial buildings. We obtained two types of data： distributed power system in 1/15 scale model of supermarket, restaurant and real world energy consumption of the two buildings. Results showed cold cabinets, whose electricity was affected by temperatures outside and inside, consumed most in supermarket. While air conditioning, affected by air enthalpy of outside and inside, consumed most in restaurant. According to our simulation with gas engine, PV （photovoltaic） panel, PCM （phase change material）, thermal storage, FCU （fan coil unit） and refrigerated cabinets in scale model, we could reduce 27% of CO_2 emission and 25% of running cost by selecting optimal size.     

Calculation of Steady SF_6 Gas Flow through a 420 kV Circuit Breaker Nozzle and Electric Field Distribution

Special interest in current interruptions is dedicated to the processes close to the current zero instant, the so-called interaction region, which determines the circuit breakers＇ performance. The quantities of interest in this region are the distribution of temperature, density and pressure, velocity and gas mass flow along the electric arc axis, as well as the distribution of electric stress between contacts Calculation of steady SF_6 gas flow through the nozzle of a 420 kV circuit breaker at the current zero instant, for different arcing durations, was carried out using a commercial CFD （computational fluid dynamics） simulation tool. The calculation results were used to get insight into improvement possibilities of the SF_6 gas flow model used in the software for computer simulation of HV （high-voltage） circuit breakers. Electric field calculation results were performed for the same 420 kV circuit breaker, in order to estimate the breakdown voltage at the current zero instant.