Study On The Automatic Programming Technology Of Four-axis NC Belt Grinding For Marine Propeller Blade

Marine propeller is an important factor to determine the performance of a ship, its manufacturing accuracy affect the quality of the propulsion system directly. Marine propeller blade is composition of complex rational space surface, most of its processing method is that milling is carried out first, and then uses a large number of artificial grinding to complete. These result in the processing take too much time and effect, and its processing precision is difficult to guarantee. Meanwhile The working conditions of workers is also extremely poor .According to the actuality and the problem of processing for marine propeller blade, In this paper, based on the background of the engineering application of NC belt grinding machine in the processing of marine propeller blade, Using ACIS geometry engine, the automatic programming technology of marine propeller blade for four-axis belt grinding machine is studied deeply in this paper, Its main contents of the paper are as follows:Firstly, analyzed deeply the standard file formats IGES and ACIS SAT format, established the conversion interface of SAT and IGES file, based on the above, imported the blade model into ACIS and extracted the surface that will be processed from the blade model,then Generated offset surface. the cutting line trajectory of belt grinding is generated on the offset surface use parameter line method according to the surface properties of marine propeller blades, studied the scatter algorithm of cutting line trajectory and node acquired algorithm, computed the tracking point on the cutting line trajectory using Parametric differential algorithm, Reduced the points information while ensured the accuracy of information, accelerated greatly the calculation speed. studied the control algorithm of cutter axis vector according to the movement characteristics of four-axis belt grinding for marine propeller blade, analyzed the mismachining tolerance generated in the belt grinding process, discussed deeply its cause and Error Compensation, researched cutting width, cutting step length and the choice of tool radius, and generated cutter location file. At the same time, studied the post-processing techniques of four-axis NC belt grinding machine, established its structure model and a relative coordinate system relative to the workpiece and the tool coordinate by way of analyzing its kinematic link, established the motion transformation equation of four-axis NC belt grinding machine according to the kinematic link, obtained the coordinates of motion for four-axis NC belt grinding machine. Then studied The axis feed speed control mode.On the basis of the above research results, designed the gross structure of automatic programming system for four-axis belt grinding of marine propeller blade, developed the system by Object-oriented method.