快递物流车车架轻量化设计开发

发布时间：2018-09-01 16:20

【摘要】：电子商务的发展带动了快递物流行业的飞速发展,但物流行业的运输成本却一直居高不下。同时,随着经济的快速发展,环境污染和能源短缺问题越来越明显,而汽车数量的增加更使这些问题日益严重。因此,节能环保、安全舒适、自重轻、成本低成为了各汽车制造企业追求的目标。根据国外的研究数据表明,汽车整车质量每降低100公斤,百公里油耗可降低0.3~0.6升;汽车整车质量每减少10%,油耗可降低5%~8%。同时,轻量化可减少原材料消耗,降低零件成本,增加企业的收益。为开发出结构合理,重量最轻的车架,本课题先是通过对标国类外成熟的轻量化车架结构,按照商用车车架的设计开发思路,选择合适规格的纵梁及横梁,并根据现有产品的特点及常见失效模式与解决措施,结合给定的整车使用工况及设计目标,应用高强度板,提出初步的优化方案。根据有限元分析结果找出车架最大应力位置,基础车及快递物流车车架纵梁上的最大应力均出现在板簧支座、驾驶室悬置支座附近,主要是这些位置需要将大总成或货物的载荷往下一级传递,局部容易出现集中载荷。这些位置在零件的设计时要特别注意孔位的布置,要避免出现三孔一线和孔距过小的情况出现。在完成了理论分析之后,通过电测试验及道路试验来验证分析结果的正确性及结构的合理性。并对试验过程中的问题进行原因分析,提出解决措施,进一步保证了产品结构的合理性及使用过程中的可靠性。基于疲劳分析理论,通过采用雨流法对动态测试数据进行分析找出最大应力和最小应力,并在简化的极限应力云图进行标记。结果显示所有测点应力数据均在所用材料的极限应力曲线范围内,说明该车架上各零件的疲劳寿命可以满足使用要求。本文运用并结合了有限元分析、电测试验及道路试验等手段,通过对比分析,设计出最优的车架结构,并通过试验检验车架的可靠性。通过将先进的理论设计方法应用到车架的设计中,升华了以前仅依靠经验进行设计的方法,避免了设计结构过于保守,以实现车架重量更轻,结构更合理。同时,通过电测和有限元分析相结合的方式,进一步验证了方案的合理性,保证了产品的可靠性,缩短了产品开发验证时间,提高了产品开发效率。
[Abstract]:The development of electronic commerce has driven the rapid development of express logistics industry, but the transportation cost of logistics industry has been high. At the same time, with the rapid development of economy, the problems of environmental pollution and energy shortage become more and more obvious, and the increasing number of cars make these problems more and more serious. Therefore, energy-saving, environmental protection, safety and comfort, light weight, low cost has become the goal pursued by automobile manufacturing enterprises. According to foreign research data, for every 100 kg reduction of vehicle mass, the fuel consumption of 100 km can be reduced by 0.3% 0.6 liters, and the fuel consumption can be reduced by 5% for every 10 kg reduction in vehicle mass. At the same time, lightweight can reduce the consumption of raw materials, reduce the cost of parts, and increase the income of enterprises. In order to develop the frame with reasonable structure and the lightest weight, this subject firstly selects the longitudinal beam and the crossbeam of suitable specification through the mature lightweight frame structure outside the standard country and according to the design and development idea of commercial vehicle frame. According to the characteristics of the existing products, common failure modes and solutions, combined with the given vehicle operating conditions and design objectives, the application of high strength plate, put forward a preliminary optimization scheme. According to the results of finite element analysis, the maximum stress position of the frame is found. The maximum stress on the longitudinal beam of the base vehicle and the express logistics vehicle frame appears near the leaf spring support and the cab suspension support. Mainly, these positions need to transfer the load of the assembly or cargo to the next stage. Special attention should be paid to the location of the holes in the design of the parts so as to avoid the occurrence of the three hole line and the hole spacing too small. After the theoretical analysis is completed, the correctness of the analysis results and the rationality of the structure are verified by electrical test and road test. The causes of the problems in the test are analyzed, and the solutions are put forward to ensure the rationality of the product structure and the reliability in the process of application. Based on the theory of fatigue analysis, the maximum and minimum stresses are found by using rain flow method to analyze the dynamic test data, and the simplified limit stress cloud diagram is marked. The results show that the stress data of all the measured points are within the limit stress curve of the material used, which indicates that the fatigue life of the parts on the frame can meet the requirements of application. In this paper, the optimal frame structure is designed by means of finite element analysis, electric test and road test, and the reliability of the frame is verified by test. By applying the advanced theoretical design method to the design of the frame, this paper sublimates the previous design method which only relies on experience, and avoids the design structure being too conservative, so that the weight of the frame is lighter and the structure is more reasonable. At the same time, the rationality of the scheme is further verified by the combination of electric measurement and finite element analysis, which ensures the reliability of the product, shortens the verification time of product development and improves the efficiency of product development.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.32

【参考文献】