Research On A Tool Path Planning Method With Cutting Tool Jumping For Machining Large Size Grid Board

Grid aluminum alloy board is regarded as main structure of carrier rocket,which influences the storeroom weight,and overweight carrier rocket reduces the ability of its launching.Since it is important to decrease carrier rocket weight,and removal rate is 60%-70%.CNC machining method is used to machine aluminum alloy board,but machining efficiency can not meet the requirements of aerospace technology developments.This thesis breaks through the tool path constraint of cavity shape by traditional machining method path planning problem,and the method of jumping machining which crosses cavity shape characteristics and involves inertial factor is studied to provide new thought to improve the machining productivity.Cavities’ loop tool path including offset and spiral path is often used to be path planning method of machining grid board.this paper studied the algorithm of spiral tool-path with the same cavity characteristics.In order to analysis the reason of low machining efficiency,this paper regards machining time as evaluation indicator.S velocity planning are utilized to build feed speed and time calculating formula.This thesis analyses the distributed rules of velocity and acceleration.At the same time,it studied the influence factors to machining efficiency,which includes machine tool’s acceleration and inertial mass.The result is that optimizing acceleration and inertial mass of moving beam is effective method to improve the machining productivity in the process of tool path planning.In consideration of inertial mass of the machine tool’s beam,jumping machining method is proposed for this problem.this method breaks through restraint of cavity shape in the process of tool path planning.In addition,it transforms X-Y axis’ motion and Z axis’ interval into X-Y-Z’s linkage.In order to improve machining productivity,jumping and offset tool path machining methods are used in rough and finish machining respectively.With taking account of acceleration and inertial mass,jumping planning of acceleration and deceleration is designed by S velocity planning method.At last its machining time is calculated.The jumping tool-path algorithm is built.By the analysis system,its efficiency is verified.On the premise of the above work,jumping machining strategy is adopted to experiment and simulation.this thesis complements the experiment at factory machine system platform.The result is that jumping tool path improved 14.27% than offset tool path,4.35% than spiral tool path in the process of simulation which provides new technique for machining board can improve the efficiency.