高速冷冲击精密成形大模数花键质量控制研究

发布时间：2018-02-27 18:08

本文关键词： 冷冲击成形大模数花键机床振动金属流动规律成形成性一体化调控　出处：《太原科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：大模数花键连续冷冲击精密成形是一种新型冷体积成形技术,基本原理是在室温下利用一对滚打轮对工件进行快速击打,迫使工件表面金属发生塑性变形,形成花键齿槽。与传统的切削加工相比,通过连续冷冲击成形的花键轴具有力学性能好,成形精度高,材料利用率高等显著优点。为提高花键成形质量,改善机床受力,本文对高速冷冲击精密成形大模数花键制造过程中打击力的影响因素进行理论分析和仿真分析,确定出机床结构参数和生产工艺参数等因素对成形过程打击力影响的特点和程度。研究了制造过程中的振动,分析机床本身运行时的振动特征,应用ABAQUS有限元软件分析模拟了冲击成形过程,获得打击瞬间的载荷特征,从而给出减振建议,减小机床振动对加工质量的影响。对高速冷冲击精密成形的花键零件表面硬度进行测试,通过对成形零件金相组织分析,探索花键轴宏观性能与微观组织特征之间的关系。利用不同的加工工艺参数加工花键试样,分析成形工艺参数对冷冲击成形花键表面硬度的影响,获得控制表面硬度的方法。控制冷冲击成形过程中的金属流动是保证零件精度和性能的关键,本文通过ABAQUS软件仿真连续冷冲击成形过程,对典型位置的节点进行追踪,输出节点的位移,结合实验从宏观角度分析变形,总结成形过程的金属流动规律。通过研究得出了机床结构参数(滚打轮尺寸,滚打轮回转半径),成形工艺参数(主轴转速,进给速度),花键轴几何参数(花键模数)等对成形过程打击力的影响。高速冷冲击精密成形过程中,机床所受载荷为脉冲式,在制造过程中会引起的机床振动,对花键成形质量的影响显著,针对高速冷冲击成形的载荷特点设计减振结构,提高零件成形精度。成形工艺参数的变化使得冷冲击变形速率变化,从而影响成形零件的微观组织和宏观性能,对不同主轴转速和进给速度等工艺参数下成形的花键表面质量进行了分析,得到高速冷冲击成形花键轮轴齿部的硬度分布,给出提高成形质量的工艺优化方案。应用仿真与实验结合的方法研究了成形过程的金属流动规律,通过仿真分析对节点追踪,并经过高速冷冲击成形试验得出了花键齿典型位置的流动特点,发现高速冷冲击成形的花键齿顶位置突出,齿侧位置被压向工件内部,齿根压下量最大,轴向位置金属向打轮打出方向流动,形成端面突出,使得靠近端面处的齿顶成形不饱满。
[Abstract]:Large modulus spline continuous cold impact precision forming is a new cold volume forming technology. The basic principle is to use a pair of rolling wheels to beat the workpiece quickly at room temperature, forcing the metal on the surface of the workpiece to produce plastic deformation. Compared with the traditional machining, the spline shaft formed by continuous cold impact has the advantages of good mechanical properties, high forming precision and high material utilization ratio, etc. In order to improve the quality of spline forming and improve the force of machine tool, In this paper, the factors influencing the impact force in the manufacturing process of high speed cold impact precision forming large modulus spline are analyzed theoretically and simulated. The characteristics and extent of the influence of structural parameters and production process parameters on the impact force of the forming process are determined. The vibration in the manufacturing process is studied, and the vibration characteristics of the machine tool when it is running are analyzed. The impact forming process is analyzed and simulated by using ABAQUS finite element software, and the load characteristics of the impact moment are obtained, and the vibration reduction suggestion is given. To reduce the influence of machine tool vibration on machining quality, the surface hardness of spline parts formed by high speed cold impact precision forming was tested, and the metallographic structure of formed parts was analyzed. The relationship between the macroscopic properties of spline shaft and the microstructure of spline shaft was explored. The effect of forming parameters on the surface hardness of cold impact forming spline was analyzed by using different processing process parameters. The method of controlling surface hardness is obtained. Controlling the metal flow during cold impact forming is the key to ensure the precision and performance of parts. In this paper, the continuous cold impact forming process is simulated by ABAQUS software, and the nodes in typical position are tracked. The displacement of the output node is analyzed from the macroscopic angle of the experiment, and the metal flow law in the forming process is summarized. Through the research, the structure parameters of the machine tool (the size of the roller, the radius of rotation of the rolling wheel, the technological parameters of the forming process (spindle rotation speed), and the parameters of the forming process are obtained. The influence of feed speed, spline shaft geometry parameters (spline module) on the impact force in the forming process. In the process of high speed cold impact precision forming, the load on the machine tool is pulse type, and the vibration of the machine tool will be caused during the manufacturing process. According to the load characteristics of high speed cold impact forming, the vibration absorption structure is designed to improve the forming accuracy of parts. The change of forming process parameters makes the change of cold impact deformation rate. Thus, the microstructure and macroscopic properties of the forming parts are affected. The surface quality of the spline formed under different spindle speed and feed speed is analyzed, and the hardness distribution of the gear teeth of the spline is obtained by high speed cold impact forming. The process optimization scheme to improve the forming quality is given. The metal flow law of the forming process is studied by the method of simulation and experiment, and the node is tracked by simulation analysis. The flow characteristics of the typical position of spline teeth are obtained by high speed cold impact forming test. It is found that the top position of spline teeth in high speed cold impact forming is prominent, the side position of tooth is pressed to the inner part of the workpiece, and the reduction of tooth root is the largest. In axial position, the metal flows in the direction of striking wheel, forming the end face protruding, which makes the tooth top near the end face not full.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG386.3

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