Optimization Design Method Of Dry Double-clutch Module

The automatization of transmission system speed change has always been the goal people pursue constantly. As the need of market to automobile equipped with automatic transmission increases rapidly, the application of automatic transmission of automobile has much more important practical significance. Nowadays, the automatic transmission of automobile in the market mainly are AT, CVT and AMT which has been being researched with great efforts at home and abroad in recent years.Although AMT has retained high transmission efficiency, low price, easy to manufacture and other advantages of MT, its working principle decides the production of power transmission interruption in the process of gear change, which will definitely produce the impact of power transmission system. Compared with AT, the interruption of AMT power transmission makes the shift quality of automobile relatively bad, which will have certain influence to automobile's smoothness, power, comfort, economical efficiency and release of fuel oil and acceleration performance. AT can make automobile start placidly and make acceleration equably and softly, but traditional AT structure is comparatively complex and the manufacture cost is relatively high. Therefore, pursuing the automatic transmission which can not only sufficiently use the advantages of high transmission efficiency and good production inheritance of MT, but also realize not to interrupt power shift and have comparatively good smoothness become the topic concerned by automobile industry in the globe. Hence, a kind of automatic transmission adopting double-clutch structure (DCT) come into existence as the situation requires.It is generally recognized that DCT is an upgrading product of AMT. It integrates the advantages of MT, AMT, AT and other transmissions and improves the vehicle performance greatly; in addition, it has a low cost and broad application. However, as one of important parts of DCT system, double-clutch module is a kind of new clutch form, so there are still some technical problems which need to be improved. To China, which is the third big production country of automobile in the world, the deep research and product of it will definitely have positive significance to improve our independent development ability of automatic transmission and the position of big automobile country.There are two kinds of double-clutch used in DCT, dry and wet. Taking dry double-clutch as the research object, on the basis of double-clutch design module made by former researchers and taking theory analysis as the foundation, the thesis checks the basic parameters of dry double clutch again and makes the research of simulated finite element analysis through leading the physical model of flywheel, middle flywheel, clutch cover I and plate I into ANSYS by Pro/E software with seamless link technology. The thesis analyses the calculated result carefully, evaluates the reasonability of initial design of structure, finally proposes the improvement plan and makes optimization design to the parts using Topological Optimization module of ANSYS software and combining with actual situations. The main works of the thesis are as follows:(1) Introduce production, development and advantages of double-clutch automatic transmission, analyze the research and development significance of double-clutch automatic transmission and the problems of structure that will be met during the development process, and then introduce the main research contents of this thesis.(2) According to parameter information of engine and basic parameters of whole transmission system and combining with expected performance requirements of DCT, the thesis makes analysis of work characteristics to the designed dry double-clutch module and checks the basic parameters of frictional plate, pressure plate, diaphragm spring and other components and parts of dry diaphragm spring double-clutch. The result shows that the designed module can meet the work requirements of double-clutch automatic transmission.(3) On the basis of work characteristics and basic parameters meeting the requirements, the thesis establishes finite element model to the partial structure of flywheel, middle flywheel and clutch I of developed and designed dry double-clutch module using the basic theory of finite unit method and relying on ANSYS software, respectively stimulates each work situation to make statics and energetics analysis on the basis of former researches and then researches on the reasonability of its structure design.The finite element calculation shows that the analyzed structure design is accordance with design requirements. However, it is also found in the research that although the intension, rigidity, thermal stress and transfiguration of designed structure meet the design requirements, there are also situations of material waste and uneven stress distribution, so it is necessary to make weight reduction optimization design in the case of meeting structure requirements.(4) Respectively carry out topological optimization analysis and improvement to flywheel, middle flywheel, clutch cover I and plate I basing on finite element method emulative analysis result, using topological optimization method of continuous body structure and taking the least strain energy of structure as the goal. It is proved that the structure material distribution after optimization is much more reasonable through comparing and analyzing the finite element calculation results of structure before and after optimization under the same condition, and at the same time of lightening structure quality, the structure stress is also reduced and homogenized, which proves the feasibility of topological optimization design method of continuous body in the structure weight reduction aspect.The thesis makes finite emulation to module through analyzing work characteristics of dry double-clutch module and using ANSYS software. After making the detailed analysis to emulative result of structure, the thesis evaluates the reasonability of initial design of structure and finally exploringly proposes structure improvement plan using topological optimization module of ANSYS software. The work content provides significant reference value to the improvement of dry double-clutch module and development and design of DCT system.