【作者】 饶志敏；

【导师】 迟关心；

【作者基本信息】 哈尔滨工业大学 ， 航空宇航制造工程， 2011， 硕士

【摘要】 电火花线切割加工技术是一种广泛应用于模具、高级陶瓷与现代复合材料等领域的关键加工技术。随着市场对加工工件质量的要求不断提高,应用于单向走丝电火花线切割加工设备的新技术、新工艺等推陈出新,展现了很高的技术水准。一直以来拐角加工精度技术便是线切割加工中的难题与关键技术。在此背景下,本文研究了一种应用于单向走丝线切割粗加工阶段的拐角轨迹策略,旨在通过在拐角处应用规划的数控轨迹以提高拐角加工形状精度。本文建立了电极丝滞后量与电极丝运动速率的关系。在一定条件下,认为电极丝滞后量与电极丝运动速率满足正比例的关系。应用电极丝滞后量与电极丝运动速率两者的关系,并根据电极丝运动轨迹与数控系统运动轨迹的几何关系模型确定了电极丝运动方向,实现了对拐角处电极丝运动轨迹的仿真并针对不同类型的拐角提出了相应的拐角轨迹策略以提高加工拐角的形状精度。在完成拐角轨迹策略过程中借鉴了优化设计的思想。主要完成了直线与直线拐角与部分直线与圆弧拐角的轨迹策略研究。由仿真结果显示,采用拐角轨迹策略生成的电极丝轨迹与拐角轮廓间的误差减小。设计了正交试验以建立电极丝滞后量与部分主要加工参数之间的关系,并对实验结果进行了回归分析。通过验证实验比较了是否采用拐角轨迹策略所切割的拐角轮廓。由实验结果知,应用拐角轨迹策略后切割的拐角形状精度有一定提升,拐角轮廓外边缘形状精度改善明显,内边缘形状精度改善较外边缘稍差。为了使拐角轨迹策略可视化,开发了应用拐角轨迹策略的软件。该软件的输入输出均为数控代码,拐角处的仿真轨迹与规划轨迹均可在软件中显示。更多还原

【Abstract】 WEDM has been gaining wide acceptance in modern tooling applications and evolved as one of the most promising alternatives for the machining of the advanced ceramics and modern composite materials. As the market demand for improving the quality of the workpiece, new technologies and processes were applied in WEDM, which demonstrated a high level of technology. Improving the corner geometrical accuracy was difficult and important. Path strategies applied in rough cutting were developed to reduce geometrical inaccuracy of corner in this paper.This paper established the relationship between the distance of wire electrode lag and the velocity of the wire electrode. Under certain conditions, supposed that the distance of wire electrode lag and the velocity of wire electrode to meet the direct proportion relationship in this paper. Based on the relationship between the wire lag and the velocity of wire and the geometrical model between the wire electrode path and the NC path, a simulation path of the wire of cutting corner was worked out and the path strategies corresponding to different types of corner were proposed to improve the corner shape precision. In the development of path strategies applied in the optimization design ideas. Path strategies for the corner contained two lines and the corner contains line and circle were developed. The simulation results revealed that the error between the wire path and the corner contour reduced.To establish the relationship between the distance of wire lag and the main influencing factors, a test based on Taguchi method was carried out and the test results were analyzed through regression analysis. The shapes of corner were compared by using path strategies for the corner or not. The experimental results demonstrated that the contour accuracy of the corner improved by using the path strategy for the corner. To visualize the corner path strategy, software about corner path strategy was developed. The input and out of the software both were NC codes. The simulation path and the strategy path were both displayed on the screen.更多还原