VVT-i泄漏量检测台结构设计开题报告

编号无锡太湖学院毕业设计（论文）相关资料题目： VVT-i泄漏量检测台结构设计 信机 系 机械工程及自动化专业学 号： 0923123学生姓名： 任晨曦 指导教师： 范圣耀 （职称：副教授 ） （职称： ）2013年5月25日目 录一、毕业设计（论文）开题报告二、毕业设计（论文）外文资料翻译及原文三、学生“毕业论文（论文）计划、进度、检查及落实表”四、实习鉴定表无锡太湖学院毕业设计（论文）开题报告题目： VVT-i泄漏量检测台结构设计 信机 系 机械工程及自动化 专业学 号： 0923123 学生姓名： 任晨曦 指导教师： 范圣耀 （职称：副教授 ） （职称： ）2012年11月25日 课题来源自拟科学依据（包括课题的科学意义；国内外研究概况、水平和发展趋势；应用前景等）（1） 课题科学意义随着我国汽车保有量的持续增加，汽车发动机泄露量检测作为影响发动机性能的一道重要工序，就显得越来越重要。发动机泄漏量检测台的运用减少了发动机故障的发生,为发动机正常工作提供了保障，提高产品的市场美誉度。本课题属工程设计类课题，要求完成VVT-i泄漏量检测台结构的设计。通过本设计，可以帮助学生加深对本专业的相关知识理解、加强学生对科学研究的基本功训练和提高综合运用专业知识独立分析问题、解决问题的能力。（2） 汽车自动清洗机研究概况VVT-i中文全名：可变气门正时系统。英文全名：Variable Valve Timing-Intelligent。VVT-i的前身，是一套名为VVT的配气相位技术，全称是VARIABLE VALVE TIMING：可变气门正时控制系统，虽然到了今时今日已经算不上什么新鲜玩意，或者已经有点跟不上技术潮流了，但在其推出的时候，的确引起过阵阵的轰动，让人们可以知道原来凸轮轴与凸轮轴皮带轮之间可以是活动连接的，并可以根据引擎的转速和工况对气门正时进行调整的！但VVT发动机并不能做到随时适应各种路况，它一般只有两套固定的控制模式，比如车速在70码以下都用模式A，70码以上则用都模式B。丰田的VVT-i则解决了这个问题，能够随路况的变化而不断改变控制模式 VVT-i和VVT的区别就像 无级变速器CVT 和 普通有极变速器一样VVT现在已经不算是先进的技术了，欧洲厂商现在已经很少提到它。奔驰和宝马的发动机都带有VVT，可是从来就没有在宣传资料里提到过。帕萨特也有，上海大众也没宣传过，奥迪也是。日系车和韩系车也只在我们国内宣传VVT技术，因为在国内这项技术依然是“尖端科技”（国内目前还没有自主的VVT技术）。和VVT类似的技术还有本田的VTEC，其实这项技术国外早在80年代就风靡过了。不过本田的i-VTEC和丰田的双VVT-i在世界上依然是先进技术，世界上掌握这类“连续可变”技术的厂家除了日本的“两田”外目前就只有德国大众和宝马了。汽车行业已发展近一百年，至今国内还没有完全拥有自主知识产权的汽车。汽车中最关键的部分是发动机，控制部分的ECU，国内依然空白。虽说国内的某些汽车厂家如：奇瑞。自称已经拥有完全自主知识产权的汽车，其实也是把别人落后几十年的技术弄回来稍微加工加工，完全没有自主知识产权可言。眼睁睁看着国内广大的市场而销售汽车的大部分钱落入外国账户。在这样的背景下，许多从国外留学回来的有志之士，运用国外的先进文化知识，利用国内的广阔空间，从事着汽车行业，为国内汽车行业的腾飞做出贡献。研究内容(1) 了解VVT-i泄漏量检测台的工作原理；(2) 熟练掌握机械设计的基本原则和有关计算机绘图软件，并绘制有关零件图，装配图等； (3) 熟练掌握液压系统的组成，控制部分及辅助元器件的选用；(4) 掌握油箱的构造，组成零件及造型；完成设计说明书的撰写，并翻译外文资料1篇。拟采取的研究方法、技术路线、实验方案及可行性分析通过对泄漏量检测台功能要求和运行过程的分析，确定检测台结构设计的总体设计方案，观察VVT-i的工况，确定实验台架的组成部分。确定各组成部分的元器件。根据台架的组成部分及元器件，给出台架初步构想图。确定台架部分的结构、详细尺寸、材料及加工方式。对液压部分进行重点分析计算，选择元器件。考虑安全问题，通过设计保护措施保护试验人员安全。研究计划及预期成果研究计划：2012年11月12日-2012年12月2日：按照任务书要求查阅论文相关参考资料，填写毕业设计开题报告书2012年12月3日-2013年1月20日：进入工厂实习，了解企业生产流程。2013年2月11日-2月23日：查找一篇关于泄漏量检测的英文资料，并完成翻译。2013年2月25日-3月2日：确定VVT-i泄漏量检测台结构设计的总体方案。2013年3月4日-3月30日：完成零件图的绘制。2013年4月1日-2013年4月13日：完成装配图绘制。2013年4月15日-2013年4月18日：设计计算。2013年4月20日-2013年5月18日：说明书的编写和修改2013年5月20日-2013年5月25日：完成论文，准备答辩。预期成果：按照计划完成本课题的设计，可以基本实现汽车自动清洗机的工作要求。所设计的控制程序，能够基本实现。特色或创新之处（1）主题明确，有针对性。（2）使用简易，功能完善。已具备的条件和尚需解决的问题条件：机械设计的基础知识，与课题相关的资料、期刊、文摘等问题：检测台的性能需在安装在实际设备中进一步的调试与多次记录数据对比之后进行完善。指导教师意见 指导教师签名：年 月 日教研室（学科组、研究所）意见 教研室主任签名： 年 月 日系意见 主管领导签名： 年 月 日英文原文Engine parts leak detection technology and applicationFirst, an overview of the voiceLeak detection techniques, sometimes referred to as the test technology or sealing leakage detection technology. In recent years has been widely used in automobile manufacturing industry, such as the cylinder block water jacket, water set of cylinder head, crankshaft oil holes, etc., in addition, there are clearance volume measurement and engine assembly testing, etc.With the application and development of leak detection technology, also has formed a professional manufacturers, more prestigious manufacturers such as Germany, French ATEQ JWFROEHLICH company, inc., United States of the U - SON company, COSM Intertech corporation, in addition to Japan, Tokyo Microctrol van type strains commune, Italy, etc.Leaking test machine is made up of leak detection instrument, mechanical sealing clamp, up-down material mechanical parts and electric control system composition and so on. Some manufacturers such as Germany, a Florida company, not only can provide all kinds of leak detection equipment, and can provide try leakage or leakage automatic line. In the leak detection technology, the first to point out is leaking and not leak is just a relative concept, is no leakage in theory, only when the leakage quantity does not exceed certain limits, we think that is not leak, or qualified.Second, fundamental knowledge of leakage1.1 the flow of the fluidA leak is content by a limited space to run to the external or other substances by space outside into the inside. Contents can be gas, liquid or solid. Limited space can make all kinds of explanation, such as engine cylinder body was sealed channel is a limited space. Leak, in short, is a kind of fluid flow phenomenon. In general, is fluid flows through the holes on the object or the. Fluid flow, like the flow of the electric, electronic mobile because a potential of high and low, as long as the potential difference between the conductors, there will be a flow of electric charge. Movement of material must have motive power, the electric potential difference is the driving force. Leakage, leakage amount depends on the size of the prime mover, available under type said: Q = f (delta), where Q said leakage, delta said impulsion, f is the function. F is a complex function normally, it is very difficult to determine the size of the, if we see it only as a kind of extremely pure proportional relationship, and also only to a pressure difference - delta, type on the Q = C (P1, P2), the proportionality constant C type, P1, P2, said the space both inside and outside pressure, leakage of the prime mover is like current electromotive force, C is like conductance, so can be C said as conduction. A leakage is refers to the fluid through the holes through the phenomenon, through the quantity is related to pressure difference on both sides of the hole, also with the ease of flow through, namely, conduction.1.2 fluid motionAccording to fluid mechanics theory, the flow of the fluid are two kinds of state, the laminar flow and turbulent flow. When laminar viscous force plays a leading role, the particle is governed by viscous fluid, not voluntary movement, the inertial force plays a leading role when turbulent flow, fluid particle in high-speed motion viscosity no longer bind it. In the vacuum technology, can be divided into laminar (viscous flow) and molecular flow. According to the theory of gas molecular motion, for through the gas cylinder, when the gas when the mean free path is larger than the diameter of the cylinder, as molecular flow. On the other hand, the mean free path of gas hours, than the diameter of the cylinder is viscous flow.1. 3 the pipeline resistance and conductionWith the conduction of electricity needs a conductor, the conductor is the pipeline. For the leak itself, whether it is a small hole or crack, can be regarded as a kind of pipe. In the type, Q = C (P1, P2), conduction C as the reciprocal of resistance. Therefore, can be calculated in the pipeline transmission pipeline resistance. Fluid flow is far more complicated than the electric conduction, when calculating the C value, should be according to the size, shape, pressure pipe, fluid characteristics, such as specific conditions to calculate. If a container under a certain pressure leak, but it does not leak. Could get, from we have talked about the formulas of gas and liquid in the same pipeline transmission is not the same.2.1 leakage of formContainer leak phenomenon, such as water leakage of the engine cylinder, usually is mainly due to the local tissue loose on the blank casting quality, casting or machining error cause the hole wall is too thin and process caused by unequal sealant plugging place daub reason.In fact, for leakage technology, there is no need for accurate understanding of the leakage of various forms, but it is also impossible. Leak detection belongs to a kind of non-destructive testing, metallographic analysis of it is different from the material. Therefore, we can do is determine leakage.In order to better understand the leakage phenomenon, it is necessary to know some similar diffusion and through the phenomenon to leak phenomenon. These phenomena in the gas flow through solid this point, and the leakage of the result is the same.Diffusion phenomenon refers to both sides of the gas in a vehicle with a differential pressure, or pressure difference. Gas from high pressure or high pressure to low in the direction of the flow direction. This phenomenon is similar to leak. When the vehicle is solid, gas from medium flows through the holes, or spread to the vehicle (vehicle no leak hole) flow after the past. In both cases is belong to which kind of, sometimes it is difficult to judge.Through refers to gas from a solid passed dissolved the material first, increasing concentration, finally in the wee hours.2.2 the leakageThere are three kinds of leakage of representation:(1) in size, such as round and straight shape, inner diameter and length is how much for each please indicate as said. Actually this size measurement is very difficult to do it, even cant do. So, this method is not practical.(2) using leak, said to the difficulty of the transmission box. This way is not said leakage shape itself, but said the size of the gas pathway.(3) expressed in gas flow. This method has been widely used, because it is easy to use instrument to measure the flow of gas, or gas flow measurement with a collection of bubbles method.3.1 the classification of test methodTo one device to know the leaks, and will know how much its leakage, must exert a prime mover, i.e. let the device produces a pressure difference between inside and outside, so can the device compression or decompression two ways. In addition, can also be classified according to the leak detection process, one kind is placed, another for dynamic method. Also have according to the determination of object classification, can be divided into the amount of gas or liquid quantity measurement and pressure measurement directly or partial pressure measurement.In the above detection method, pressure method is used for the detection of commonly used methods. Pressure method is used for the detection of commonly used methods. Place pressure method and pressure method and pressure dynamic method. Decompression method is commonly referred to as vacuum method, this method is no compression method used widely, but it has high detection accuracy, and easy in the workpiece to be measured have to seal. Vacuum process, like pressure, vacuum and vacuum dynamic placement. Such as vacuum differential pressure method, liquid coating method, etc. And methods used in the vacuum conditions than the kinds of pressure under the condition of the kinds of detection methods.3.2 selection of leak testIn numerous detection methods, each method has its different features. Choices should consider who is suitable for, those who dont fit. According to the different features of various detection methods to choose from the following aspects into consideration:Principle: (1) irrespective of the approach, dont fully understand the principle of the method, will not get good result.(2) the sensitivity (the minimum leakage can be measured) should consider which method is used to measure of the level to which the leakage.(3) detection time irrespective of the detection method, it takes a certain time. For placement testing, from Richard will extend the placed time will improve the sensitivity and the detection of an artifact of the leakage takes a long time, obviously cannot be used for on-line detection of engine parts.(4) test environment of various test methods is different to the requirement of test environment. If adopt the method of measuring pressure value, it is follow the ideal gas equation of state, so the temperature, humidity and other factors on the measuring results is larger, the influence of the choice is must be taken into account.(5) leakage position judgment in all kinds of detection methods, some can only give to the leakage, leakage can determine whether artifacts, but it cant leak, some can reflect the workpiece is leaking, and determine leak, but the specific leakage it is difficult to get, and can give leakage, can determine the specific leak again. If want to repair the leakage of the workpiece, the leak of the judgment is necessary.6 reliability leak detection belongs to a measuring technique, the measurement must be credible and reliable. All kinds of method is usually accompanied by human eye detection, due to the factors that, its consistency is poor, but is stable and reliable. And various instrument method, although better consistency, but its stability and reliability of the instrument, and many other factors influence.All landowners economy detection efficiency when choosing method of measurement is also a factor to consider. The above items is our starting point of how to choose what kind of test method. In specific choices, they should be and other factors, such as tests, the influence of work piece to seal the ease of combination of consideration, and choose the best method for leak detection.4 several major leak detector and the detection methodIn the leak detection technology, at present the main leakage detector and the detection method has a) absolute pressure type leakage detector b) differential pressure type leakage detector c) mass flow leak detector4.1 the absolute pressure type leak detector and the detection methodCommonly used is the step-down method, also can use booster and the vacuum is measured. The test procedure can be roughly divided into: pre inflatable, inflatable, voltage regulator, measurement - exhaust five stages; 1 open the valve, air inflated to the pressure P, filling stage and can be broken down into pre aeration and aeration step or two. Stable stage: 1 valve closed, this phase is to provide the stable gas and heat exchange of time, it is necessary for precise measurement, the stable phase over the instantaneous pressure value as a reference pressure storage.Phases: measurement system for measuring. To monitor the final pressure, and comparing with reference value, measure the P values, P values in excess of the prescribed threshold for unqualified, leak rate can be obtained by P value V; Exhaust phase: the artifacts in the gas from the atmosphere, usually adopts loose blocking artifacts to exhaust.4.2 the differential pressure type leak detector and the detection methodIn the absolute pressure type testing instrument, sensitive element USES the pressure sensor, differential pressure type leakage detector is used in the differential pressure sensor. Differential pressure type of leak detector measurement process basically is divided into five stages. The difference is inflatable stage 1, 2 valve are opened. By gas phase into the stable (balance), 1 off valve, the valve open 2, so the balance at the end of the stage, back pressure chamber H and L pressure equal to the pressure room, P = 0.When entered the measurement phase, valve shut off. If leaks artifacts have L cavity pressure is reduced, producing pressure differential P, in the same way, and can be determined from P V leak rate. Absolute pressure and differential pressure type leak detector detector is measured by using the pressure value to indirectly measure the change of the leak rate of V.4.3 the mass flow type leak detector and the detection methodMass flow type leak detector is directly measured workpiece leak flow instrument, the sensitive element is the flow sensor (usually using the module component). In flow sensor with a constant temperature heating system, when the air flow (flow) change, take away the heat change make temperature t, so that the temperature of the closed-loop system heating current (or voltage) changes, which can measure the flow changes, due to the zero method is used to measure, so it can obtain higher precision. This kind of flow sensor can detect very small flow not only, also can measure the larger flow leakage rate, but also can measure the direction of airflow.Due to flow was measured under constant temperature, so the measured mass flow rate is, the relatively small effect on the temperature, can be used for leak detection of large flow, large volume.In order to improve the accuracy of measurement, the mass flow type testing, also often use standard artifacts and gas circuit composed of workpiece to be measured. When the workpiece to be tested for leaks, the pressure is reduced, while the standard artifacts the pressure inside the container remains constant. Sensors pick up between the two artifacts, compressed air pressure is P from the standard workpiece to be measured by sensor artifacts.Despite the above three kinds of measurement methods can meet the requirements of the vast majority of leak detection, but from practice situation and price level, first recommended the use of leak detector is absolute pressure type, because it is simple, reliable, does not need to balance the reference artifacts. Under the condition of the high accuracy requirement, it is recommended to use differential pressure type leak detector. Under the big leakage flow, is recommended to use mass flow type leak detector, such as leak detection of inlet and exhaust valve seat.5 engine parts, leakage try leakage process analysis and commonly used methodSealing is a relative concept, based on the theory of leakage of theory and practice, the flat parts dont leak, how to determine the leakage of engine parts and do not leak? Common practice is to give the maximum allowable leakage, and time needed for testing should be regulations, working temperature and working pressure, etc.In engine p