碳纤维复合材料陀螺式制孔刀具运动分析

Kinetic analysis and machining quality study of tilted orbital milling process for CFRP hole making

碳纤维复合材料(Carbon Fiber-Reinforced Plastic,CFRP)由于其优良的力学性能而被广泛应用于航空领域,但是在制孔过程中,在孔的出入口部位容易发生撕裂、分层和纤维拉出等缺陷,如何实现CFRP的高质量制孔成为工业生产中急需解决的技术难题。为此,提出了一种陀螺式制孔工艺,将铣刀倾斜一定的角度,使得铣刀在自转的同时围绕孔中心轴线做圆锥摆动式公转,并沿孔中心轴线方向进给。分析了该工艺下刀具在孔入口和出口阶段的运动特性和材料去除速度的变化情况,并通过试验研究了制孔轴向力的变化情况以及制孔质量。结果表明,与螺旋铣孔相比,陀螺式制孔在孔入口和出口阶段材料去除速度和制孔轴向力均呈现平滑变化的趋势,消除了螺旋铣孔时的突变现象,孔加工质量得到了明显改善。

Carbon Fiber-Reinforced Plastic ( CFRP) are widely used in the aerospace industry due to their excellent mechanical properties. However,during the hole-making process,it is easily produce dilacerations,laminations and fiber pullout in the entry and exit positions of hole. Therefore, high quality hole making of CFRP is a technical problem that needs to be solved urgently in industry. A tilted orbital milling method for CFRP hole making is proposed, in which the tool axis is tilted toward the hole axis and moves around it with a conical pendulum motion, meantime feed downward in the direction of hole axis. The kinetic characteristics of tool and the materials removed rate during the hole making process are analyzed firstly. And then the cutting force in the direction of hole-axis are collected and the hole quality is analyzed through experiments. The results show that, compared to helical milling process. The changes of the materials removed rate and axial cutting forces are smoother in the proposed tilted orbital milling process. The sharply changing of axial cutting forces during helical milling process is eliminated and the hole quality is improved significantly in the titled orbital milling process.