【作者】 张瑞；

【导师】 赵婷婷；

【作者基本信息】 山东理工大学 ， 材料加工工程， 2016， 硕士

【摘要】 自由锻是金属坯料体积成形的一种基础工艺。目前自由锻工艺是在锤和液压机上实施的,压制工艺重复精度较低,锻件一致性低、余量大、公差大,造成了后续切削加工的浪费。开关磁阻伺服电机新技术的发展,使开关磁阻伺服螺旋压力机实现了数控功能,为螺旋压力机上自由锻带来了发展机遇。本文围绕伺服螺旋压力机上自由锻与机器人的控制技术进行研究,主要研究内容如下:(1)对自由锻用伺服螺旋压力机的最佳机型进行分析。以效率最高为目标函数,建立了伺服螺旋压力机机型优化的数学模型,对各种伺服螺旋压力机的传动结构及其综合刚度进行了比较分析,揭示了伺服螺旋压力机打击效率与综合刚度的关系;并对伺服直驱和花键直驱螺旋压力机的综合刚度进行了有限元分析,揭示了螺旋压力机的最优结构,阐明了直驱螺旋压力机具有高效率的机理。(2)提出了伺服直驱螺旋压力机上自由锻的数控成形方法,借助于直驱螺旋压力机主运动高速数控技术,通过引入当量刚度的概念,阐明了打击能量与打击力的关系;通过吨位仪的实时监测,实现了不同的打击速度、打击能量、打击力的数控。并使用DEFORM软件对自由锻工件进行了伺服成形不同参数的数值模拟,对工艺参数进行了分析,获得了圆柱Φ38mm自由锻镦粗工艺的最优参数。(3)对伺服直驱螺旋压力机上自由锻与机器人协调控制进行了研究,使用SolidWorks建立了伺服螺旋压力机和机器人的三维样机,对机器人进给运动的轨迹进行了规划,利用ADAMS确定了机器人夹持端位移与速度的变化情况,以连续工作循环时间最短为优化目标函数,确定了机器运动的最佳轨迹,确保了螺旋压力机主运动与机器人进给运动以最高效率动作的同时,机器人与螺旋压力机的关联运动不发生干涉。(4)利用高效率的伺服直驱螺旋压力机,采用优化后的工艺参数,进行了自由锻的实验,验证了仿真模拟的有效性和三段工艺参数的优势。对打击力的重复精度进行了数据分析,对不同自由锻件的尺寸一致性进行了分析,实际打击力与仿真模拟的结果误差在10%以内。论文研究结果表明,所进行的伺服直驱螺旋压力机上圆柱Φ38mm自由锻镦粗工艺,达到了打击效率0.8398,打击力重复误差小于2%,自由锻件尺寸偏差小于0.2mm的目标。本论文成果对自由锻工艺的变革有引导作用。更多还原

【Abstract】 Free forging is a basic process of metal forming. Free forging process is currently carried out on the hammers and the hydraulic presses. The press processes are in low precision and the forge pieces are in low uniformity, large allowance and tolerance, which result in the waste of subsequent cutting machining. With the development of the new technology of switched reluctance servo motor(SRSM), the screw presses driven by SRSM have realized the function of numerical control(NC) that leads to the development opportunity of free forging on screw presses.In this paper, the control technology of the robot and the free forging on the servo screw press was studied. The main research contents are as follows:(1) The best types of the servo screw press applied in free forging were analyzed. With the highest efficiency as the objective function, the mathematical model of the optimization of the model of the servo screw presses was established. The transmission structure and the stiffness of various servo screw presses were analyzed. The relationship of striking efficiency and whole stiffness of the servo screw presses were revealed. The whole stiffness of the screw presses with direct drive and spline direct drive were analyzed. The optimal structure of the screw presses was revealed. The mechanism of the high efficiency of the direct drive screw press was expounded.(2) The NC forming method of free forging on servo direct drive screw presses was put forward. With the application of the NC technology of the high main movement speed of the direct drive screw press and by introducing the concept of equivalent stiffness, the relationship between the striking energy and the striking force was clarified. Through the real-time monitoring of tonnage instrument, the NC of different speed, energy and force were realized. The different parameters of workpieces by free forging were simulated by DEFORM software. The process parameters were analyzed. The optimal parameters of cylinder Φ38mm for upsetting process of free forging were obtained.(3) Research on the coordinated control of the robot and the free forging on servo direct drive screw press. The 3D prototype of the servo screw press and the robot were built by using SolidWorks. The trajectory of the feed motion of the robot was planned. The running states of displacement and velocity of the robot’s clamping end were determined by ADAMS, the optimal trajectory of the motion of the two machines were determined by optimizing the objective function with the shortest cycle time of continuous work. With the highest efficiency, it was ensured that the synthetic motion between the main movement of screw press and feed movement of robot didn’t interfere.(4) The free forging experiments were carried out by the high efficient servo direct drive screw press, adopted the optimal process parameters. The effectiveness of the simulation and the advantages of the parameters of three stages are verified. The data of the repeat precision of the strike force and the uniformity of different size of forge pieces were analyzed. The error of the actual striking force and the simulation result was less than 10%.The results of the study in this paper showed that: the free forging process of upsetting cylinder Φ38mm on the direct drive servo screw press, reached the targets that the striking efficiency of 0.8398, the repeated error less than 2% of striking force, the size deviation less than 0.2mm of forge pieces. The results of this paper has a guiding effect in the change of free forging process.更多还原