基于柔性铰链的精镗误差补偿机构研究

发布时间：2018-08-14 10:56

【摘要】：在批量加工的环境下,尤其在汽车制造业,随着加工的进行,刀具的磨损误差是影响加工精度的重要因素。为提高加工精度和效率,工业生产普遍采用具有自动刀具补偿功能的补偿镗头进行孔的半精、精加工。镗削刀具微量进给装置作为执行补偿动作的机构,成为此类批量自动生产线的核心技术。本文基于柔性铰链技术从理论、仿真出发,提出了新型的变形体结构,并通过试验分析应用于工程项目产生了良好的经济效益。论文首先总结了微位移机构的基本形式,分析了多种镗削刀具补偿装置结构方案,最终采用柔性铰链结构的平行四边形变形体方案,利用楔面机构进行驱动实现了刀具的径向微量补偿。分析了变形体四杆机构耦合运动、连杆加工误差对微位移补偿的影响,结果显示所引入的误差只有0.1%,该机构有良好的线性性及导向性。推导了正圆型单铰链、正圆型双铰链转角公式和刚度公式,并利用Matlab对公式采用数值积分求解,获得了柔性铰链的转动刚度和结构设计参数之间的曲线关系图。依据理论公式,论文设计了三种结构方案的变形体,并利用有限元分析软件ANSYS对其进行了刚度、强度分析。为揭示变形体铰链参数变化对镗刀补偿范围、精度的实际影响,论文设计了一台用于检验变形体补偿性能的精加工试验装置,完成了试验平台的机械结构设计、PLC电气控制以及软、硬件调试。利用设计的试验装置,本文对变形体进行了多组螺栓预紧力探究性试验,选取了顶杆最佳初始预紧力。对变形体进行了补偿能力试验、重复定位精度试验、补偿精度试验、抵抗切削力变形试验,结果表明单铰链变形体较双铰链变形体补偿范围提高了367%,更适合于刀具补偿范围大于0.2的场合。双铰链变形体结构补偿精度及刚度指标优于单铰链结构,适合用于调刀范围在0.1~0.2场合。目前研究成果已经应用到三一重工股份有限公司泵车水箱专机、东风康明斯发动机有限公司缸套专机项目,相关性能指标达到国外同类产品水平。
[Abstract]:In the batch machining environment, especially in the automobile manufacturing industry, tool wear error is an important factor affecting the machining accuracy with the development of machining. In order to improve the machining accuracy and efficiency, industrial production generally adopts the compensation boring head with automatic tool compensation function for semi-precision and finishing machining of holes. Based on the theory and Simulation of flexure hinge technology, a new type of deformed body structure is proposed in this paper, and good economic benefits are obtained by applying it to engineering projects. Firstly, the basic form of micro-displacement mechanism is summarized and analyzed. In the end, the parallel quadrilateral deformation of the flexible hinge structure is adopted to realize the radial micro-compensation of the boring cutter. The coupling motion of the four-bar mechanism of the deformed body is analyzed, and the influence of the machining error of the connecting rod on the micro-displacement compensation is analyzed. 0.1%. The mechanism has good linearity and directivity. The rotation angle formula and stiffness formula of circular single hinge and circular double hinge are deduced. The formula is solved by numerical integration in MATLAB. The curves between the rotational stiffness of flexure hinge and the structural design parameters are obtained. According to the theoretical formulas, three kinds of structures are designed. In order to reveal the actual influence of the variation of the hinge parameters on the compensation range and accuracy of the boring cutter, a finishing machining test device is designed to test the compensation performance of the deformed body, and the mechanical structure design of the test platform is completed. PLC electricity is used. Air control, software and hardware debugging. Using the designed test device, this paper has carried out exploratory tests on the pre-tightening force of bolts for deformed bodies, and selected the optimum initial pre-tightening force of the ejector. The compensation range of the double-hinged deformable body is 367% higher than that of the double-hinged deformable body, which is more suitable for the occasion where the tool compensation range is greater than 0.2. The compensation precision and stiffness index of the double-hinged deformable body are better than that of the single-hinged structure, and it is suitable for the occasion where the tool adjustment range is between 0.1 and 0.2. Dongfeng Cummins Engine Co., Ltd. cylinder liner project, the relevant performance indicators to achieve the same level of foreign products.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG53

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