【作者】 王晓军；

【导师】 王三武；

【作者基本信息】 武汉理工大学 ， 机械制造及自动化， 2010， 硕士

【摘要】 曲轴是车用及船用发动机的重要部件,它负责将活塞产生上下往复运动变成发动机输出轴的旋转运动。在曲轴的机加工这一环节中,连杆轴颈的加工是一个难点,这是因为连杆颈的轴线相对于主轴颈的轴线是偏心的。目前国内曲轴生产线主要是由普通机床和专用机床组成,生产效率和自动化程度相对较低。国内曲轴加工的设备主要还是依赖于国外昂贵的进口设备,这就大大增加了曲轴加工的成本。针对这个问题,研究设计出了一种新型的曲轴加工机床。由于这种新型车床特殊的加工方式,因此对头架箱主轴旋转运动与刀架旋转运动的同步性要求很高。本文就是以头架箱主轴端至刀架系统输入端之间的传动链为对象,对传动链的同步精度以及补偿控制进行研究。本文的主要内容如下：1.根据主轴—刀架传动链的三维模型建立了传动链的对象模型。对转角误差的来源进行了分析。特别地,对于轮齿啮合综合误差,给出了一种概率统计的计算方法,并利用该方法对主轴—刀架传动链的转角误差进行了初步计算。2.研究主轴—刀架传动链动力学模型。以齿轮副扭转模型和齿轮—转子系统模型为基础,建立主轴—刀架传动链的刚度—阻尼模型。以轮齿啮合综合误差为理论依据,建立轮齿啮合综合误差分析模型。根据分析模型,运用理论力学的相关知识,建立微分方程组。运用拉普拉斯变换法对微分方程组进行求解,得出对应模型的转角传递函数,最后得到总传递函数。运用MATLAB软件对总传递函数进行响应分析,并比较不同负载下的转角传递函数的响应。3.研究电机输出端至刀架输入端的补偿传动链的动力学模型。通过建立分析模型和数学模型,得到了头架箱主轴与刀架的转角之差与电机输出转角的传递函数。4.建立机床主轴与刀架的同步精度补偿控制模型。运用MATLAB软件对该控制模型的静态特性和动态特性进行了相关分析。对补偿控制模型的控制精度进行核算。更多还原

【Abstract】 Crankshaft is an important component of automotive and marine engines, which is responsible for turning the up-down motion of the piston into the rotation of the output shaft of the engine. In the part of the crankshaft machining, the processing of the Crankshaft connecting rod neck is a difficult, because the axis of the connecting rod neck has a eccentric relative to the spindle axis of the crankshaft.Currently, the crankshaft production line is mainly made up of common machine tools and special machine tools, with relatively low production efficiency and automation. In China, the crankshaft machining equipment mainly rely on being imported from foreign countries, which greatly increase the costs of the crankshaft machining. To address this issue, a new kind of the crankshaft machining tool has been designed.The processing method of this new type of lathe is special, which has a high demand for the rotary movement synchronization of the headstock mainshaft and tool holder. This article makes the transmission chain from the headstock mainshaft to tool holder input as an object and studies the synchronization accuracy and the compensation control of the transmission chain. The main contents of this article are as follows:1. According to three-dimensional model of headstock-tool holder transmission chain, the object model of the transmission chain is established. We have analyzed the sources of rotation error. In particular, for the composite error of the meshing teeth, we give a calculation method based on probability statistics, and with which the rotation error of the transmission chain has been calculated initially.2. Studying the dynamic model of the transmission chain of headstock-tool holder. The stiffness-damping model of the transmission chain has been established, based on the gear pair torsion model and gear-rotor system model. The analysis model of the composite error of the meshing teeth also has been built, which is based on the theory of the composite error of the meshing teeth. We have used the corresponding knowledge of theoretical mechanics to establish the simultaneous differential equation, according to the analysis model. Using the Laplace to solve the simultaneous differential equation, we get the corresponding rotation transfer functions, and finally obtain the total rotation transfer function. With the help of MATLAB, we can analyze the response of the total rotation transfer function. What’s more, the response of rotation transfer function of the model with different load torques can be compared.3. Studying the dynamic model of the transmission chain between the output of the servo motor and the input of the tool holder. Though building the analysis model and mathematical model, we can obtain the total rotation transfer function between the output rotation of the servo motor and the rotation error of the headstock mainshaft and the tool holder.4. We have established the control model of the synchronization precision compensation for the mainshaft and tool holder of the machine. Using MATLAB software, we make a correlation analysis on the static characteristics and dynamic characteristics of the control model. The control precision of compensation control has been verified.更多还原