The Theoretical And Experimental Study For Workpiece Spindle Speed Of CNC Camshaft High Speed Grinding

With the implementation of energy conservation and green manufacturing industry policy,camshaft is the key components of the engine for automobile, ships in new high technology fields, the comprehensive performance of the engine is directly affected by its processing quality, so its contour machining accuracy requirements of processing are increasing. Camshaft processing methods has been raised from the mechanical cam grinding to CNC machining, greatly improving the contour accuracy and surface quality. When grinding non-circular contour of the cam lift, the grinding speed change dramatically, C axis and X axis grinding with great acceleration, the machine tool servo system cause greater mechanical shock, grinding servo system may not meet the requirements of high speed machining due to the possibility of producing a response lag. So it is necessary to optimize and adjust the workpiece spindle speed based on the grinding machines processing feed capacity constraints.In this paper, high speed CNC camshaft grinding workpiece spindle speed as the research object, the camshaft CNC grinding motion mathematical model is built, derived cam workpiece spindle speed equation under constant linear velocity conditions. Analyze the constant linear speed of the workpiece spindle speed which is affecting the processing quality. Set the maximum acceleration limitation value of wheelheed based on the processing capacity of the camshaft grinding machine. For the part acceleration of wheelheed feeding process which exceeds limit value, by integrating to solve the workpiece spindle reverse permitted maximum speed, and use the speed replace the constant linear theoretical speed on corresponding corner range. The optimized workpiece speed fitting by cubic spline curve is applied in CNC8325 B CNC camshaft grinding machine for grinding experiment, the experimental results show that the quality and efficiency are improved in the processing of the camshaft. Research work include the following:(1) Analyze the camshaft CNC grinding characteristics and process methods, studied the spindle feed servo system performance and structural characteristics of the camshaft high speed CNC grinding. Compare the processing characteristics of constant angle grinding and the constant linear speed processing characteristics of camshaft CNC grinding, study the influence of workpiece spindle speed to camshaft CNC grinding processing quality.(2) Derived camshafts X-C two axis CNC grinding mathematical model, study the wheelhead linkage feed process kinematic analysis, simulated the displacement, velocity and acceleration values of the wheelheed in the feeding process, the cam lift data were optimized to fit through using the least squares polynomial. The wheelhead feed allowed maximum acceleration value is derived based on contour interpolation geometric constraints, wheel frame feeding capacity constraints.(3) According the grinding machine feed acceleration capability set the acceleration limits, the camshaft workpiece spindle speed is calculate for the wheelheed feeding process its acceleration curve by integrating reverse. The optimized workpiece speed and constant linear speed are applied to the camshaft high speed grinder for comparative experiment. The results show that processing through the use of workpiece speed which is optimized for lowering the wheelheed feed acceleration, the processing quality and efficiency are improved in the efficiency and precision grinding of camshaft.