【作者】 姜永成；

【导师】 任福君；

【作者基本信息】 哈尔滨理工大学 ， 机械制造及其自动化， 2008， 博士

【摘要】 在许多制造电子、仪表、电机、飞机以及火箭等所用的模具中,多数部件要求有落料斜度或上下截面具有不同的形状,而往复走丝电火花线切割加工技术已成为加工这类部件的重要手段之一。由于,目前国内加工空间曲面零件通过采用锥度切割装置使电极丝倾斜一定角度来实现锥度切割,这种加工方法容易产生较大的加工误差。同时,由于加工过程的自动化程度低而严重影响了空间曲面零件的加工质量。因此,本文提出了空间曲面往复走丝线切割智能制造系统关键技术的研究。论文的主要研究内容如下所述。空间曲面电火花线切割加工技术包括空间曲面往复走丝线切割CAD/CAM技术以及空间曲面往复走丝线切割数控技术。论文首先概括国内外空间曲面电火花线切割加工技术发展现状,并给出课题研究的背景与意义。随后,基于本智能制造系统的主要研究问题提出了应用多轴联动运动控制技术进行空间曲面往复走丝线切割智能制造系统关键技术研究的主要内容及技术路线。对于空间曲面数学模型而言,应用数学建模方法及数据库技术建立了基于极坐标方程和直角坐标方程的通用数学模型及综合数据库。通过对常用基于ISO标准的G代码图形合成程序的分析,建立了G代码程序解释模型,形成了空间曲面的两种高效合成方法。扩大了空间曲面零件的加工工艺范围。在空间曲面线切割CAD/CAM集成方面,根据系统的功能与数据结构,采用多种计算机技术建立了具有空间曲面建模、仿真及加工实时跟踪的图形化仿真平台。针对数控系统的软硬件设计问题,将开放式体系结构思想引入到五轴联动电火花线切割加工中,设计并实现了基于可编程多轴运动控制器(Programmble Multi-Axis Controller,PMAC)的开放式体系结构电火花线切割加工数控系统的硬件体系。为了确保电火花线切割数控加工软件的实时性能,采用电火花线切割加工轨迹堆栈和运动轨迹分割等处理方法,开发了多轴联动电火花线切割加工数控软件的内核模块和用户空间程序。创建了用于电火花线切割加工运动控制的PMAC运动程序,以及加工进给率控制PLC程序。实现了电火花线切割加工间隙电压检测任务、间隙调整任务及运动轨迹自动回退任务等。在五轴联动电火花线切割机床机构设计方面,首先通过分析空间曲面机构运动学及其结构特点,提出五轴联动往复走丝线切割机床的总体设计方案。基于Pro/E三维设计环境进行转摆摆工作台的参数化三维建模,并在Adamas下建立其虚拟样机。通过对转摆摆工作台动态特性的分析,验证了机构设计的正确性。随后,研制了数控转摆摆工作台原理样机,并与标准二维往复走丝线切割机床共同构成了五轴联动往复走丝线切割机床,为高精度空间曲面零件加工奠定了基础。针对往复走丝线切割加工中电极丝张力变化影响加工精度的问题,基于伺服控制技术,提出基于多轴运动控制器(PMAC)的电极丝恒张力控制方法,消除了电极丝张力变化对加工精度的影响。最后,本文对研制空间曲面电火花线切割智能制造系统加工空间曲面零件的过程进行了实验研究。实验结果证明,工件加工精度较高,验证了空间曲面往复走丝线切割智能制造系统的合理性和稳定性。更多还原

【Abstract】 Nowadays, so many moulds in machining Electronic device, Instrument, Motor, Airplane and Missile should have blanking taper or different shapes between up and down section view. The technique that processes spatial curved surface (SCS) in Wire Electronic Discharge Machining with High Speed (WEDM-HS) is one of the most important processing methods. The wire tool can incline at an angle by a special taper device to get SCS parts in WEDM-HS, but this processing method can generate error easily and the low automation degree of its CNC system also reduces the SCS processing quality. Therefore, the research on the key technique of intelligent CNC system in WEDM-HS is proposed in this paper. The main content is given as follows.The processing technique includes its CAD/CAM technique and its Numerical Control (NC) technique. From these two aspects, the actual condition of SCS processing technique in WEDM-HS is resumed, the background and significance of this research are proposed at the beginning. Then, on the base of the main research works, the main content and the technique route of SCS intelligent CNC system are proposed by the application of Multi-axis motion control technique.As for the SCS mathematical module, on the base of machining means of swaying motions of parts, respectively in the Polar coordinates and Descartes coordinates, the general mathematical model and the universal database are established by the application of mathematical method and database technique. On the base of the analysis on normal ISO G code program, the G code interpretive system is established, and a high efficiency SCS composition method is proposed. All these works expand the SCS parts processing range.For the integration process of SCS CAD/CAM system, the graphic simulation platform is established which can model SCS, and simulate machining process, also can follow machining track in real time with several computer techniques.For the software and hardware architecture designing of CNC system, on the base of open architecture of Programmable Multi-axis Controller (PMAC) and opened architecture idea of five axes linkage machining in WEDM-HS, the NC system hardware architecture is developed.In order to realize real time characteristic of NC software, on the base of machining track stack and motion track dissection, the kernel module and user space program of multi-axis SCS NC software are developed. The PMAC motion program and PLC program of feed rate adjustment are established and the gap adjustment and motion track auto back functions are realized.For the mechanism designing of five axes linkage WEDM-HS machine, the structure characteristic and kinematics are analyzed. The whole mechanism design plan of SCS machining in WEDM-HS is proposed. The parameterized three dimensional model of the NC Rotary Table with Two Sways (RTTS) in Pro/E is established and the virtual prototype of RTTS is also established in Adams. On the base of analysis on dynamic property in Adams, the RTTS design plan is well validated. The RTTS prototype and the five axes linkage WEDM-HS which composed of the RTTS and normal WEDM-HS are established, and this entire works pay the foundation for the study on the high precision SCS machining.For improving machining precision of SCS, on the base of the analysis on bad influence of precision by the changed wire tool tension and the servo control technique, the constant tension control module of wire tool is proposed with the PMAC. The test results show that the bad influence of precision is well eliminated and the machining precision of SCS is improved.At last, the SCS machining tests are done and the machining test results show that the samples have a sound precision and the intelligent CNC system has a good rationality and stability.更多还原