碳纤维复合材料吸气式自排屑钻削方法工作原理及基础研究

The powder chip generated during CFRP drilling, which is bad to enticement and meanwhile harm to the operator. Nowadays, the powder chip is collected by industrial vacuum cleaner manually. Due to the entrance of the hole is the only way from which the chip passes, the chip is not collected at the beginning of generation, which causes the friction between cutting tool, chip and surface machined. Targeting the problem, a new machining method is presented, named inhaling automatic chip drilling. It can collect the chip immediately after chip generation, and passes inhaling hole, tool handle, spindle, and chip channel, and enter the container, however, there are many important scientific problem, so this proposal is to solve those issues. First, the powder chip generation mechanism well be studied, and the relationship between it and cutting tool parameters, which can provide a way to control the chip flow. And then the constraint condition will be researched to build the flow field of cutting area, which can provide a theory method to cutting parameter decision. Secondly, the boundary conditions of fracturing hole exit bar will be studied, which can demonstrate the function that the inhaling reduce the exit bar. And then, the project research the friction mechanism between cutting tool, chips and surface machined, which can make decision of inhaling parameters. Finally, inhale drill will be designed, as well as the whole inhale drilling system, which provide a platform for the application of this method.

碳纤维复合材料钻削过程会产生粉末状切屑，污染环境，同时影响工人的身体健康。而目前，采用人工方式利用吸尘器将切屑吸走，由于只能从孔入口区域吸取，而不能在产生时直接吸取，会产生刀具、切屑和工件的摩擦。针对这一主要问题，本项目提出全新的加工方法--吸气式自排屑钻削，使切屑在产生的瞬间，便可通过刀具的吸气孔，经过刀柄、主轴等进入储存装置，但是有许多理论、技术问题没有被解决，因此本项目采用理论与试验相结合的手段，首先，开展CFRP粉末状切屑形成机理，确定与刀具参数的关系，进而实现对切屑流向的控制；确立的钻削约束条件进而建立切削区域流场，为刀具气孔参数设计与优化提供理论指导。然后，研究毛刺折断临界条件，进而揭示吸气式加工对毛刺的抑制作用；研究刀具-切屑-工件研磨机理，进而分析吸气条件下的刀具磨损特征，为吸气参数的确定提供理论指导；最后，设计并研制吸气式刀具，优化吸气式实验系统为其应用提供技术平台。

钻削加工碳纤维复合材料（Carbon Fiber Reinforced Polymer CFRP）时会产生粉末状切屑，能否及时排屑会影响刀具的使用寿命，并且扩散的切屑对环境、加工设备及操作者有较大的危害。本项目针对碳纤维复合材料制孔加工中切屑有效实现实时回收的问题：首先，提出并设计了一种新型钻削加工工艺系统--吸气式内排屑系统，能够及时有效的排出CFRP制孔加工中产生的切屑，实现绿色加工；其次，研究了切屑的形成机理及切屑类型分类，并分析了切屑类型对排屑效果的影响；第三，以气固两相流体力学中颗粒悬浮速度的计算为理论依据，给出吸气式内排屑系统排屑所需负压值的求解方法；第四，通过分析钻削过程中吸气式内排屑系统切屑的排出过程，建立切屑流场区域，给出专用内排屑钻头内流道设计的基本依据，并采用仿真分析的方法，分析了排屑流道结构对排屑性能的影响，以完成吸气式内排屑系统用内排屑刀具内流道结构的设计及优化；第五，实验研究了CFRP制孔加工时PCD双峰角刀片结构参数对钻削力的影响规律，并根据该规律设计了吸气式内排屑系统用PCD双峰角刀片；最后，搭建吸气式内排屑系统，制造内排屑刀具及外转内排屑刀柄，进行内、外两种排屑系统排屑效果和制孔缺陷的对比实验分析，以及内排屑系统排屑效果影响因素分析和刀具磨损机理的研究。