Simulation And Experimental Research On Aspiration Self-chip Drilling CFRP

Nowadays,the chip output of CFRP drilling is still based on the workers hand-held vacuum cleaner which is low efficient,environmental polluted and the CFRP hole it produced is of bad-quality.But suction type internal chip removal drilling tools as an important part of the suction-type self-chip system can effectively solve the problem that the CFRP chip can not be discharged in time.Now,it has become the prioritiy of research on chip removal technology of CFRP drilling at home and abroad,and the reasonable selection of drilling parameters and the negative pressure of chip evacuation have significance on practical value and practice.Firstly,the structure and working principle of the suction-type inner chip removal system were elaborated,and the factors which influence the efficiency of chip removal in CFRP drilling were analyzed.Research and experiment were done based on self-developed CFRP drilling tool for polycrystalline diamonds,and the flow control equation of chip evacuation simulation,the turbulence model in the flow path of the inner chip removal tool and the near wall region model were established for research and experiment.Secondly,the chip flow velocity in the chip flow channel was calculated based on the study of the properties of CFRP chips.And by using Fluent and 3D modeling software,three-dimensional flow path model of inner cutting tool was established.Gambit meshing method was also used to simulate the inner chip cutting tool in fluid mechanics.In the process of simulation,SIMPLEC was used to solve the calculation equation,and the numerical simulation of airflow inside the tool was realized.Thus,the pressure,velocity and turbulent kinetic energy distribution were obtained,and the chip removal characteristic was analyzed.Thirdly,as the speed of the inner chip cutting tool and the change of thenegative pressure of the outlet would influence the effect of the chip removal of the inner chip removing tool,thus the occurrence of clogging or chip could not be discharged,chip removal performance of the toll was needed to be prodicted.It was done by a chip removal estimation model establised by Fluent according to the instantaneous stress analysis of the chip removal process of CFRP chip,it helped us understand The relationship between the negative pressure value,the rotation speed of the chip and the chip removal performance of the inner chip cutting tool of polycrystalline diamond for self-developed CFRP drilling.Finally,CFRP aspirated inner chip drilling test system was built due to the transformation of the drilling machine which was led by the transformation of the suction pump through vacuum generator.Under the design condition,The time of chip removal and the effect of chip discharge were compared based on the experiment results.Thus,the chip removal performance was evaluated and the simulation results were validated.