Research Of Cutting Force And Cutting Parameters Optimization For Spiral Bevel Gear Using CNC Machine Tool

Researches on cutting force and cutting parameter optimizations are meaningful forimproving machining efficiency and processing quality of the CNC spiral bevel gearmachine-tool, and are fundamental for the spiral bevel gear machine tool design. Based on thenewest CNC tooth surfaces cutting mechanism, mesh simulation technology and optimizationalgorithm, using the methods of dynamic cutting force simulation, cutting parametersoptimization, and the simulation of the tooth flank average scallop height, the spiral bevelgear CNC machining is simulated and experimented, in order to improving rough machiningefficiency and finish machining precision.In the thesis, the research achievements and creative include：Based on the geometrical theory of the form milling the spiral bevel gear, the computationalmethod of the instantaneous undeformed chap thickness and width was deduced. The millingforce model for form milling the spiral bevel gear is presented, the milling force factors werecalibrated using orthogonal experiments and the form milling force simulation programs wereprepared. Experimental installations were designed to validate the availability of the millingforce model. Comparison between the computational results and experimental observationsconfirms the validity of the proposed model within±15%deviation.Based on the modified-roll method geometry theory and4-axis CNC machine-tool kinematicsprinciple, the instantaneous undeformed chip area formulas of the spiral bevel pinion roughmilled were deduced. According to the traditional milling force model, the spiral bevel pinionrough milling force model based on the modified-roll method were presented, the millingforce simulation programs were composed and the experiment schemes were designed. Theexperiment results showed that the amplitude of the main motor input power and thetransducer output power are almost in the same interval.According to the milling force models were founded in Chapter2, a new control meanssubject to the approximatively constant instantaneous cutting force in variable feed-rate werepresented. By changing the value of the feed-rate keywords of the NC cord, the variably feedrate during the milling process is achieved. This means bring on less fluctuate of theinstantaneous tangential cutting force, smaller vibration and noise, higher quality andefficiency, longer machining tool life. Experiments were carried out to verify the usability of the means.`A new scheme based on the harmony search algorithm (HSA) was proposed. The objectivefunction is the minimum machining time (or highest productivity) and the lowest processingcost, the constraint conditions include the maximum cutting speed, cutting power and the toollife of the blades. The optimization variables include cutting speed, generating speed and thesingle-step interpolation angle. The optimum programs are prepared using MatLab. Anexperiment case is performed to verify the effectiveness of the optimization model.Based on the finish machining theory of the spiral bevel gear using CNC rolling method,functional relationship between the tooth surfaces average scallop height and cuttingparameters(cutting speed, multi-axis traveling speed and single-step interpolation angle) werefounded, and analysis were made to make clear how the cutting parameters work on theaverage scallop height. Results shows: cutting speed or generating speed has smaller effect onaverage scallop height while the single-step interpolation angle seriously. Tooth flank averagescallop height can be used as a pro-forma criterion of the tooth flank roughness. These kindsof law are verified by experiments.