PD24J化油器怠速孔试密封设备设计开题报告

欢迎下载本文档参考使用，如果有疑问或者需要CAD图纸的请联系q1484406321编号无锡太湖学院毕业设计（论文）相关资料题目：PD24J化油器怠速孔试密封设备设计 信机 系 机械工程及自动化专业学 号： 0923209学生姓名： 周 亚 芳 指导教师： 冯 鲜 （职称：讲 师 ） （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：PD24J化油器怠速孔试密封设备设计 信机 系 机械工程及自动化专业学 号： 0923209 学生姓名： 周 亚 芳 指导教师： 冯鲜 （职称： 讲 师 ） （职称： ） 2012 年 11 月 25 日 课题来源当今社会人们对汽车的需求越来越普遍，汽车制造业已经成为我国制造业的支柱产业。汽车配件产业也是重要的制造产业，其中汽车的铝合金配件制造是一个技术性很强的行业。摩托车化油器实际上是给摩托车发电机提供可燃混合气的开关,是节制燃油和平衡气压的开关。汽油经过化油器的雾化，送到燃烧室，通过火花塞点火，启动发动机运转是摩托车的主要供油系统,关系到车的动力，所以本课题进行了化油器的研究。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） 课题的科学意义： 化油器作为一种精密的机械装置，它对发动机的重要作用可以称之为发动机的“心脏”。化油器的作用就是将一定数量的汽油与空气混合，以使发动机正常运行。通过本课题的研究，可以把有关化油器壳体的加工工艺与加工设备有机地结合起来；同时，通过采用优化的工艺方法、先进的加工设备，提高产品的质量稳定性，从而可以降低排放，减少对环境的污染。（2） 研究状况及其发展前景： 汽油机在正常工作状态下，在小、中负荷时要求化油器随着负荷增加能供给由较浓逐渐变稀的混合气，在满负荷下又要求混合气由稀变浓，为了满足这些要求，在现代化油器上配备了一系列的混合气浓度补偿装置。如主供油泵、怠速系、省油器、加速系及起动系等，以确保汽油机在不同工作状态下，化油器能供给适当浓度的混合气。 摩托车化油器有严格的密封要求。针对密封性对化油器有着至关重要的地位：提高劳动生产效率,保证加工质量,降低劳动强度。PD24J化油器的试密封夹具装置主要是通过气缸对PD24J化油器怠速孔进行定位与夹紧。 化油器的主要缺点是向气缸充气和混合气的分配并不理想，影响发动机的动力性和经济性的提高，对达到排放要求很不利。 在新型汽车中，开始普遍地采用燃油喷射系统，因为它可以使燃油效率更高而排放更低。但是，几乎所有的旧式汽车以及所有的像割草机和链锯之类的小设备均使用化油器，因为化油器既构造简单又价格便宜。 研究内容1、方案设计，确定实用方案。 2、机械部分设计。此设备的机械部分主要是由焊接机架、工件定位与夹紧部件组成，要进行夹紧力等的计算；并绘制机械部分图。 3、气动部分设计。此设备的气动部分主要是由气源三联件、气缸和气压控制阀组成，需进行气缸的相关计算。 4、部分电气部分设计。 电气部分包括PLC控制,全电脑泄漏检测仪的选用组成 。 拟采取的研究方法、技术路线、实验方案及可行性分析1、 根据“六点定位原理”将化油器进行定位；2、 设计夹紧装置将化油器进行夹紧；3、 采用气缸通过压缩空气产生的力来提供夹紧力；4、 将整体装置放到待检测区域，进行试密封性的检测。研究计划及预期成果研究计划：2012年11月20日2012年12月20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25日2013年2月25日：填写毕业实习报告。2013年2月26日2013年3月3日：按照要求修改毕业设计开题报告。2013年3月4日2013年3月14日：学习并翻译一篇与毕业设计相关的英 文材料。2013年3月15日2013年4月1日：机械部分设计。2013年4月2日2013年4月15日：气动部分设计。2013年4月16日2013年4月26日：部分电气部分设计。2013年4月27日2013年5月21日：毕业论文撰写和修改工作。预期成果：完成设备的机械部分、气动部分、电气部分的设计及相关计算，绘制好机械部分设计的二维图纸。特色或创新之处已具备的条件和尚需解决的问题1、 对化油器有一定的了解，定位准确且夹紧可靠，具备试密封性试验的检测条件，可以进行密封性检测。2、检测装置的能力仍有待提高。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 无锡太湖学院毕业设计（论文）外文资料翻译 信机 系 机械工程及自动化 专业院 （系）： 信 机 系 专 业： 机械工程及自动化 班 级： 机械95班 姓 名： 周 亚 芳 学 号： 0923209 外文出处： 机械专业英语教程 附 件： 1.译文；2.原文；3.评分表 2012 年 5 月 25 日 英文原文1. The carburetorCarburetor is under the effects of the vacuum engine working, will be a percentage of the fuel and air mixing mechanism. It to important function that the engine can be called the heart of the engine. The complete device shall include starting device, idle speed device, medium load, full load device, accelerating device. Carburetor will according to the requirements of different working state of the engine, automatically matching the corresponding concentration, output the corresponding amount of mixture, in order to make the mixture mixed more evenly, carburetor has make fuel atomization effect, for the normal operation of machine.Simple carburetor is made up of 3 three parts, the part with air inlet and the float chamber, the middle section there are pipes, orifice, nozzle, how a portion of the valve, etc. Float chamber is a rectangular container, store of gasoline from the gasoline pump, there is a float container using surface (oil level height controls the input. In the middle of an oil inlet and the amount of float chamber nozzle hole, the other end oil outlet in throat throat.It is throat waist, two big middle small, of which the minimum cross-sectional area of throat. Suction when the engine is started the piston downward, inhalation of maximum speed when the airflow through the throat, static pressure is the lowest, so the throat pressure less than atmospheric pressure, that is to say throat throat and produced the pressure difference between the float chamber, that is the people often say vacuum, the greater the pressure range of vacuum. Under the action of gas in the vacuum from the oil outlet nozzle jet, because of throat throat 25 times that of gas flow rate of air flow, so the nozzle jet flow that is dispersed by high speed air flow, forming fog particles of various sizes, namely atomization. Initial atomizing oil mixed with air into a mixture, through the throttle, air intake pipe and inlet valve into the combustion chamber of cylinder. Here, the throttle opening size and rotational speed of engine, determined the throats of vacuum degree, and the throttle opening change directly affects the mixture ratio of ingredients, these are the important reason for affecting the operation of the engine.Changes due to the concentration of the mixture with engine under various operating conditions of load change is closely related, simple carburetor far cannot satisfy the change request at any time, so people on the simple carburetor constantly add new device used for adjusting the working state of the carburetor. Development today, has formed the carburetor has a variety of auxiliary equipment, mainly are idle, tangy, acceleration and initiating device. Now 4 cylinder engine common dynamic carburetor carburetor is double cavity, it has two pipes, and according to the different engine operating conditions or work at the same time, respectively. 6 cylinder engine common carburetor is double cavity and carburetor, it is actually two single cavity carburetor and together, each cavity is responsible for half of the number of mixture gas cylinder. And multi-cavity carburetor, usually assembled on large power engine.Carburetor of the multiple functions of device, the main oil supply unit is in addition to the idle speed, engine working condition of various other needs of oil supply device, is the basic fuel supply carburetor structure. The idle device is in idle speed runtime provides few but strong mixture device, with the lowest stable engine speed. Add device is big engine load extra oil supply device, in order to make up for the inadequacy of the main oil supply. Accelerating device is increased when the car suddenly accelerated time of valve opening extra oil supply device, when the engine speed and power can be increased rapidly. Starter is to provide extremely rich mixture when the engine cold start device, the common way is in the front hose to a choke valve to control the volume.The speed of particular mention here. Working condition of engine idle speed is the most commonly used for engine thermal process and no parking stall and so on. For the car performance has very important significance, especially in city driving, idle speed condition often determine the cars fuel consumption and emission level.Engine idle speed running speed is typically 600 800 RPM, throttle close to shut down, the speed of pipes, vacuum degree cant float chamber gasoline it sucked out smoothly, but the throttle at the back of the vacuum degree is high. So just on the basis of simple carburetor of setting up a idle oil duct, the nozzle is located in the throttle, the problem is solved.Due to idle need less thick mixture, the engine operation condition is more sensitive, stable and should be the minimum speed of the idle state, to control the oil amount of the adjustment and the opening of throttle. Now the carburetor of idle speed device has two adjusting screw, adjust the oil and the throttle opening respectively. At the same time, in order to prevent the phenomenon of close auto ignition switch and the engine is still running, the oil in the carburetor idle way will also include a idle speed solenoid valve, specifically responsible for opening and closing the idle oil duct, guarantee engine can quickly shut down.2. The working principle of the carburetorCarburetor is actually a pipe, tube middle there is a called the throttle adjustable plate door plank, is used to control the flow of air through the tube. Tube has a section called venturi contraction, the shrinkage will form a vacuum. The contraction section orifice, the use of vacuum can be hole inhale fuel from now on.Motorcycle carburetor looks very complex, but as long as grasp some principle, can adjust the motorcycle to the best state. All carburetors are working under the basic principle of atmospheric pressure. Atmospheric pressure is a power to put pressure on everything. It will have slight variations, but usually fifteen pounds of pressure per square inch (PSI). This means that the atmospheric pressure in anything is fifteen pounds per square inch pressure. By changing atmospheric pressure within the engine and carburetor, you can change the pressure and make the fuel and air flow through the carburetor.The atmospheric pressure will spread from high pressure to low pressure. When two stroke engine piston at top dead center (or four stroke engines piston at the check point), under in the crankcase piston (four-stroke engine piston above) will form a low pressure. At the same time, the low pressure can also cause low pressure in the carburetor. Because of the high pressure compared to the outside of the engine and carburetor, will burst into the carburetor and air into the engine until the pressure is balanced. Air flowing through the carburetor will drive the fuel, and fuel will be mixed with air.Inside the carburetor is a throat. Throat is inside the carburetor forced air speed through the contraction section. Can all of a sudden narrowing river to illustrate the situation of occurred in the carburetor. Narrow the river near the Banks of the river will speed up, if Banks continuous narrow will be faster. If the same thing happen in the carburetor, accelerate the flow of air will lead to the inside of the carburetor air pressure is reduced.Gasoline is the fuel tank through the fuel filter again into the carburetor, fuel filter the impurities can be mixed with gasoline and the scale filter inside the tank. If the filter quality defective, there are still some impurities through the filter into the carburetor. Other gasoline contained can form gel ingredients after long time deposit will condense out of the colloid, attached to the carburetor parts (such as orifice), oil and float on the surface.Air is through air filter into the carburetor, based on the air intake resistance cannot be too big and other factors to consider, filtering device cannot too tight, so part of the tiny impurities in the air will enter the carburetor through air filter. If the filter quality defective, can cause more serious influence.Composition in the airways of the carburetor oil duct, more spare parts, such as the main measure holes, idle hole orifice, primary air, idle air hole, the foam pipe, and so on all have inside a small hole (diameter between 0.3 1.5 mm), into the carburetor petrol impurity, colloid and impurities in the air, tend to the aperture change or jams, cause carburetor airway, poor oil duct, make the carburetor fuel supply characteristics change, even cause the carburetor performance failure.3. The pneumatic systemPneumatic technology is one of the ways in which industrial production mechanization and automation. Pneumatic system the use of safe, reliable, can be in high temperature, vibration, corrosion, inflammable, explosive, more dust, strong magnetic, radiation, etc. Work under the bad environment, which application is increasingly wide. Pneumatic system and hydraulic system, are made by one or more of the most simple of basic circuits. Pneumatic circuit and common basic circuit is in order to achieve the specific functions and pneumatic components and pipes in a certain way of combined structure, analysis, design and use of the pneumatic system is.Pneumatic transmission and control is one of the most effective way in the production process automation and mechanization, but its working medium (compressed air) manufacturing cost is high, the energy utilization rate is quite low. Pneumatic actuators is mainly used to make linear reciprocating motion. Engineering practice, this kind of movement form used most, such as many machines or devices transmitting device, product processing workpiece feeding, positioning and clamping workpiece, workpiece assembly and material forming are linear motion form. But some pneumatic actuators can make rotation movement, such as the oscillating cylinder (swing Angle is 360 ). Pneumatic technology application range, in addition to the individual circumstances, to do linear motion form, from the technology from a cost point of view, all mechanical SheBi cannot compared with pneumatic equipment. (from the technical and cost point of view, cylinder as actuator is the best form of complete linear motion, like motor to complete rotation movement.) Pneumatic technology, the interaction between actuators and control element is based on the simple element. Mission requirements, these components can be assembled into a variety of system solutions. Pneumatic control agencies or equipment greatly improve the mechanization degree, and can realize fully automated, pneumatic technology has made a significant contribution to the cheap automation. In fact, a single pneumatic components, such as various types of cylinder and control valve) can be as modular components, this is pneumatic components must be combined, to form a control loop used to complete a specific assignments. Broadly speaking, pneumatic equipment can be applied to any engineering field. Pneumatic equipment is often by a small amount of pneumatic components and several basic loop combination. Pneumatic control system composition is reproducible, it laid the foundation for combination and pneumatic components and applications. In general, the combination of pneumatic components with many reservations within functions. Batch feeder is also often used as a component to provide the whole machine. Thus greatly simplify the pneumatic system design, reduce the workload of design and installation debugging personnel, make the pneumatic system cost is reduced greatly.Pneumatic system basic composition: composition of the pneumatic circuit to drive mechanism for various purposes, its content is: the three most important control force, the size of the force direction and speed of movement. Connected to production devices of various types of cylinder, by pressure control valves, directional control valves and flow control valve, the contents of the three control is implemented, i.e., the pressure control valve, pneumatic control the size of the output force, direction control valves, control the movement direction of the cylinder, the speed control valve - control the movement of the cylinder. A pneumatic systems typically include air equipment (air compressor, gas), gas source treatment components, after cooler, filter, dryer and drainage), a pressure control valve (pressure valve, pressure reducing valve, relief valve, sequence valve, etc.), lubrication components (oil mist, centralized lubrication components), direction control valves, solenoid directional control valve, pneumatic directional control valve, control reversing valve, mechanical control reversing valve, check valve, etc.), various types of sensors (magnetic switch, limit switches, pressure switches, pneumatic sensor), flow control valve (speed control valve, cushion valve, quick discharge valve), cylinder actuators (cylinder, gas motors, vacuum suction cup, etc), other auxiliary components (muffler, connection and trachea, hydraulic buffers, converter gas and liquid, etc.). A typical pneumatic system consists of direction control valves, pneumatic actuators, pneumatic auxiliary components and air purification device.4.The PLCPLC is a specialized in industrial environment application and design of the electronic device digital computing operations. It can adopt program memory, used in its internal storage implementation logic operation, sequence operation, timing, counting and arithmetic operation instruction, and can through digital or analog input and output, control various types of machinery or production process. PLC and related peripheral equipment should be in accordance with the easily and industrial control system to form a whole, easy to expand its function design principles. Early Programmable Controller called Programmable Logic Controller (Programmable Logic Controller, PLC), it mainly used instead of relay realize Logic control. With the development of technology, which USES a microcomputer technology of industrial control device functionality is considerably more than the scope of logic control, therefore, today the device called the programmable controller, hereinafter referred to as PC. But in order to avoid and Personal Computer (Personal Computer) abbreviation confusion, it will be referred to as PLC programmable controller. PLC data since 1969, when the American equipment corporation (DEC) is developed, the United States, Japan, Germany, the programmable controller of high quality, powerful function. PLC is a specialized in industrial control computer,