C2排气系统设计流程简介(2)(1).ppt

1、0,排气系统设计流程简介Exhaust System Design Report -以C2项目为例 (C2 Project) 汽车工程研究院乘用车所 Passenger Car Department2006.04.13,1,一、设计输入信息的收集,1、主要技术参数（C2项目匹配DA4G18发动机） 发动机的额定功率和最高转速（73.5kw/6000rpm） 发动机排量，是否是增压发动机（1.584L 非增压） 发动机的排气噪声频谱 一、Collecting input information 1.Main technical parameter of engine (project C2 ma

2、tching engine DA4G18) 1.Engine rating power and top rotation speed (73.5km/6000rpm) 2.The displacement of engine, engine with (or without) supercharger (1.584L engine without supercharger) 3.The frequency- register of engine exhaust- noise,2,一、设计输入信息的收集Collecting input information,2、整车底盘参数 排气管布置、走向及

3、相邻零部件的位置要求 三元催化与消声器安装位置及空间大小 排气管的总长度及悬置点位置 2.Chassis parameters of the whole vehicle 1.Layout of the exhaust gas pipe，direction and position request of near parts 2.Install position and space of the catalytic converter and muffler 3.Whole length of exhaust gas pipe and position of the rubber mount,3

4、,一、设计输入信息的收集Collecting input information,3、其它相关要求 执行的标准和法规要求（满足GB18352.3-2005中第阶段要求 ， 排放达欧标准） 成本及供应商的产品开发、质量控制及品质保证能力 系统设计控制质量 3.Other correlative demand 1.Executive standard and legislation (meeting phase in GB18352.3-2005, emission satisfied to Euro ) 2.Costs, capacity of the support supplier expl

5、oitation , quality- controlled and character guarantee 3. System design to control quality,4,二、排气系统选型方案的确定 Exhaust system electing-model plan,C2项目排气系统参照标杆样车排气系统的主体结构，采用四段式双 催化、双消声器结构. 排气管各段用平面双孔法兰连接，平面密封垫密封, 以利于三元催化器与消声器的更换。 According to the principal part of benchmark, the exhaust-gas system of pro

6、ject C2 is composed of four segments. It contains two catalytic converters and two mufflers. The vent-pipes are connected with flanges and there are gaskets between the flanges, because of this, the replacement is easier between catalytic converter and muffler.,5,二、排气系统选型方案的确定 Exhaust system electin

7、g-model plan,排气悬置方案: 后三元催化器前设置有1对弹性支撑(图1)，前消声器后设置有1只吊销(图2),后消声器上设2只吊销(图3)，共用三只双孔橡胶吊耳悬挂于车底后部。 图1(fig1) 图2(fig2) 图3(fig3) The proposal of exhaust mounts: There is a rubber mount before the rear catalytic converter (fig1) . A mount is located after the front muffler(fig2) and two are located on the rea

8、r muffler(fig3). There are three two-hole mounts hanging on the vehicle floor.,6,三、系统匹配设计与计算System matching design and calculate, 系统性能目标: Design objective: 插入损失 Insert loss 28 dB(A) 系统阻力 System pressure 38 Kpa 定置噪声 Limits of noise emitted by stationary road vehicle85dB(A) 排放达欧标准 Emission satisfied t

9、o Euro III 根据发动机排量，确定排气管采用451.5的不锈钢管 According to the engine displacement, we decided to take the pipes by the dimension of 45mm1.5mm. 根据车身空间、发动机排量及排放要求，确定三元催化剂的选型方案：According to the vehicle body ,engine displacement and emission requirement, the electing-model plan of catalytic converter is decided

10、 前级载体规格front catalytic converter spec: 9358 目数/壁厚number/cliff thickness:400/6mil 贵金属含量noble metal：35g/ft3 后级载体规格rear catalytic converter spec: 101.6152.4 目数/壁厚number/cliff thickness: 400/6mil 贵金属含量noble metal ：20g/ft3,7,三、系统匹配设计及计算System matching design and calculate,根据发动机排量及车身空间大小确定消声器容积： 前消声器采用断面为

11、153100360的椭圆形结构，容量约为4.32L, 后消声器采用断面为200160480的椭圆形结构，容量约为12.06L， 二者的总容积为:16.38L. 下表是关于竞争车型与标杆车型消声器容积的对比： 4.According to the engine displacement and the vehicle body ,we decide muffler dimension: The cross-section of front muffler is ellipse with 153100360(mm3), capacity is about 4.32L The cross-secti

12、on of rear muffler is ellipse with 200160480(mm3), capacity is about 12.06L The total volume of the two mufflers is 16.38L,8,四、排气悬置刚度及位置的设计 Exhaust gas rubber mount stiffness and position design,关于排气悬置目前尚无系统的设计规范，亦缺少经验数据支持。 以往的设计都是在车身地板或车架位置许可的条件下设置悬置点位置， 以保证排气系统的可靠性，通过CAE分析与实车试验进行验证。 参考 CAE分析所提供的C2

13、排气系统频率响应分析报告 通过报告可得出以下结论： 1、软垫刚度对排气系统各点的加速度影响不大。 、调整悬置点的位置，对整个排气系统的振动特性有较大影响。 3、现设计状态悬置需要对实车进行试验验证 At present, we do not have systemic design criterion, what is more, lacking of experiential data. In our former work ,mounts are located according to the room of floor and frame, in which can install m

14、ounts, in order to ensure the durability of exhaust-gas system , then validating through CAE and vehicle test Reference the report the exhaust-gas system frequency analysis Conclusion: 1、The stiffness of rubber mount dont do great influence on the acceleration of the points of the exhaust-gas system

15、. 2. Adjusting the positions of rubber mounts can influence the vibration of exhaust-gas system much. How to arrange is unknown yet. 3. The design of mount need vehicle test,9,五、排放控制Emission controlled,目前尚无明确的设计规范控制。 There is no specific design criterion,10,六、问题汇总Questions,1、排气系统柔性连接的最佳布置方式; How to

16、set the arrangement of flexible joints of exhaust-gas system? 2、排气管走向及直径对排气背压的影响，是否有推荐公式; Is there any recommended formulation to calculate the back pressure influenced by the pipes form and diameter? 3、如何设定排气系统的性能指标; How to design the parameters of exhaust-gas system? 目前对于每个项目的排气系统来说,插入损失及背压值在认证时是控

17、制难点，需要在设计初期予以控制，建议工装件完成后提前进行认证，以保证整改周期 It is difficult to control insert loss and the back pressure for every project at present ,we need to control them in initial design stages 4、排气悬置点的位置及相关性能参数设计选取范围; The position of rubber mounts and correlative capability parameter 5、消声器与发动机的匹配原则 The principle

18、of matching mufflers and engine. 6、排气密封方式的选择原则 The principle of choosing sealing method,11,六、所存在问题汇总Questions,1、排气系统的设计流程应该严格控制的环节有哪些? 1.What are the strictly-controlling points of exhaust gas system? 2、排气系统性能指标如何确定? 2.How to design the parameters of exhaust-gas system? 确定整个系统的还是消声器的? To confirm the systems parameters or the muffles parameters ? 莲花公司是如何确定的?主要考虑因素有哪些? How to design exhaust system in Lotus Company? 是否有相关标准?可否提供一下? Is there some standards? 3、系统物理布置注意要点?周边间隙如何确定?考虑因素有哪些? 3.Whatre the key points of dimensional disposition? How to design clearance? 4、排气管管径如何确定?计算时消声器中的气流速度一般控制在什么范