【作者】 宋永强；

【导师】 栾贻国；

【作者基本信息】 山东大学 ， 材料加工工程， 2011， 硕士

【摘要】 机械压力机是材料塑性成形中应用广泛的设备,可进行冲压、挤压、锻造等工艺,在汽车、航空、五金等工业领域起着重要的作用。作为现代机械压力机普遍采用的工作机构,多连杆机构是实现拉深、弯曲等各种工艺性能的关键部件,其设计水平的高低直接影响到工作机构性能的好坏,进而影响压力机的性能如工作效率,生产产品的质量等。八连杆机构是其中应用较为广泛的一类,但其优化设计过程复杂,不易得到工艺过程要求的运动曲线,迫切需要进行研究并实现设计和生产的优化。多连杆机构优化设计以最优化方法和计算机程序设计为基础,是解决复杂设计问题的有效工具之一。在产品的设计阶段对机械压力机工作机构进行运动仿真,可以直观地检验工作机构在工作过程中的运动合理与否、工作机构各构件之间是否发生干涉等；通过运动仿真还可以直观的分析、优化设计方案,使设计的工作机构的功能更加完善。因此,机械压力机多连杆机构,特别是八连杆机构的优化设计及运动仿真对合理设计机械压力机的工作机构具有重要的意义。基于对机械压力机工作机构优化设计及运动仿真的研究现状的回顾和综合,以八连杆内、外滑块机构为例,建立起机械压力机工作机构运动过程的通用数学表达式；通过对工作机构优化设计所需要的合理方法进行了探讨研究,确定采用复合形法对多连杆机构内、外滑块的运动情况进行优化设计,并对机械压力机工作机构的运动性能参数进行优化计算。对优化设计的具体技术内容,例如数学模型的建立、目标函数的确定、约束条件的建立、优化方法的选择等进行了阐述。对优化的主要方法进行了对比,确定了八连杆机构的优化设计方法。对工作机构进行了运动分析,建立了工作机构内、外滑块在工作循环内的位移与曲柄转角、速度与曲柄转角、加速度与曲柄转角之间的数学关系表达式,为机械压力机工作机构的优化设计、工作机构的运动仿真提供了数学基础。综合利用复合形法对八连杆内、外滑块机构进行了优化设计,以特定行程内内滑块的速度波动最小和特定行程内外滑块位移波动量最小为目标函数,优化后机构的各项性能比原机构的性能得到了相应提高。基于Visual C++ 6.0平台开发了机械压力机多连杆机构优化设计及运动仿真软件。对机械压力机工作机构的运动特性进行了动态仿真,检验设计方案的合理性的同时,可以检验工作机构各构件在运动过程中是否发生干涉、机构参数设计是否合理,为机械压力机多连杆机构的设计提供了一个合理的工具。更多还原

【Abstract】 Mechanical press, an appliance widely used for material plastic forming, enables several processes such as punching, extrusion, forging, which plays an important role in auto industry, aviation industry, hardware, light industry.As an operating mechanism general used by modern mechanical press, the multi-linkage mechanism is the key part of achieving some technique properties, including drawing, curving, whose level of design can directly affect the function of the operating mechanism. Furthermore, the property of the press such as efficiency, working quality can be influenced in turn. Eight-bar linkage is one of it used successfully hungering for enforcing design and product optimization. Based on the optimization method and the computer progress design, the multi-linkage mechanism optimization design is an effective one of methods to solve the complex design problem. During the period of product designing, the motion simulation of mechanical press can examine the operating mechanism’s working rationality and the collision among its components. Meanwhile, the operating mechanism can be analyzed directly and optimized so as to perfect the function of operating mechanism. Therefore, the optimization design and motion simulation of Mechanical press multi-linkage have become the important contents of press design.Based on reviewing and summarizing the current research situation of the mechanical press optimization design and motion simulation, taking eight-bar linkage as an example, the general mathematical expressions of the whole motion process are made up, and explore and select the reasonable method of optimization on linkage. The optimization design with complex optimization method and the computation of the motion performance parameters of the linkage are carried out.The specific application technologies of optimization, such as the establishment of mathematical model, the ascertainment of objective function, the determination of the constraint conditions, the selection of the optimization method, are elaborated. The optimization methods of eight-bar linkage are determined by comparing main optimization methods. The motion of operating mechanism is analyzed. Inner and outer sliders of the mathematics expressions on displacement, speed, acceleration and the crank angle are established, which can provide mathematics foundation for the optimization design and motion simulation of linkage.The complex optimization method is multipurpose used as optimization method. whose objective function is the forming speed of inner slider keeping a lower, fixed value and the displacement of outer slider keeping a lower value. Performance parameter is proved after optimization.The multi-linkage optimization design and motion simulation software is developed by using Visual C++ 6.0, which provides a useful tool for design multi-linkage, and can examine not rationality of the design but the interference of each bar and the rationality of parameters.更多还原