Research On CNC Machining Technology Of Honeycomb Core Parts Using Ultrasonic Tool

Due to its high specific strength and high specific stiffness,and other excellent properties,honeycomb composite materials have high application value in many fields such as aerospace.Ultrasonic machining,as a very important processing method in the field of composite material processing,has practical application value.Ultrasonic machining of honeycomb composite materials has advantages such as good surface quality and low cutting force.Domestic ultrasonic processing technology is still in the research stage,there is no reliable and standardized process design method in the processing technology part of the ultrasonic tool used for ultrasonic processing of honeycomb core parts especially.According to the structure and cutting characteristics of special ultrasonic tools used in ultrasonic machining,this paper has carried out the research on the numerical control technology of ultrasonic machining of honeycomb core parts:(1)Carry out research on the process planning of ultrasonic machining honeycomb core.A part model reflecting the typical structural characteristics of honeycomb composite parts in the aerospace field was constructed.Analyze the structural characteristics and process characteristics of the special tools for thin-edge ultrasonic cutting—straight-edge cutters and disc cutters.The residual cutting error,overcutting error and bottom edge machining error caused by the use of equivalent tools is analyzed.(2)Carry out the research on the surface topography of the workpiece processed by the ultrasonic disc cutter.Analyze the formation mechanism of the surface topography of the workpiece ultrasonically machined by the disc cutter,and build the residual height model of the machined surface topography.The single-factor and multi-factor interaction analysis of the rake angle,roll angle,and cutting line distance of the software show that the influence law of each process parameter on the residual height is: The residual height increases with the increase of the cutting line spacing;the residual height increases with the rake angle of the tool shaft,the residual height first appears the maximum value,and then decreases rapidly,and will reach the minimum residual height during the reduction process,then the residual height continued to increase slowly;the residual height increased with the increase of the roll angle.(3)Carry out the research of ultrasonic machining tool path planning.Analyze the key parameters in the tool path planning: the tool position points and tool contacts of the ultrasonic tool in the actual machining;according to the V-shaped process requirements,calculate the cutting line spacing for straight-edge cutters processing;according to the chip breaking requirements in the disk cutter processing technology,obtain the calculation model of the maximum cutting line spacing in the disc cutters processing to guide the selection of cutting line spacing;Use the arc to approximate the local path to calculate the path the length of the knife step according to the discrete accuracy required in the actual machining.Carrying out iso parametric tool trajectory planning based on parameter mapping,proposes an interference judgment method for the local interference phenomenon of straight-edge cutters and disc cutters in the machining process,and proposes a correction method for cutter interference.(4)Virtual Simulation of CNC Ultrasonic Machining Based on VERICUT.Create a machining simulation environment,for the ultrasonic tools not in the tool library,combine the tool size and cutting error analysis to set equivalent substitute tools: Verify the correctness of the established residual height model for disc cutter machining;and perform machining simulation on typical honeycomb core parts in the machining simulation,through “automatic comparison” and inspection of undercutting and overcutting,the rationality and feasibility of ultrasonic machining tool path planning are verified.