In the numerical control machine tool processing parts, the original data that the craft personnel gets is the parts diagram. According to the parts diagram, you can analyze the shape of the parts, dimensional accuracy, surface roughness, workpiece materials, blank types and heat treatment conditions, and then choose the machine tools, cutting tools, determine the positioning clamping device, processing methods, processing sequence and the size of the cutting amount. In the process of determining the process, we should fully consider the instruction function of the CNC machine tool used, give full play to the efficiency of the machine tool, so that the processing route is reasonable, the number of knife and the processing time is short. In addition, should also fill in the relevant technical documents, such as CNC machining process card, CNC tool card, knife road map, etc.
2. Calculate the coordinate value of the tool path
According to the geometrical size of the part drawing and the programmed coordinate system, the trajectory of the tool center is calculated, and all the data of the tool location are obtained. General CNC system has the function of linear interpolation and circular interpolation, for relatively simple planar shape parts, such as parts of line and arc contour machining, only need to calculate the geometric elements of starting point and end point, the circular arc of circle (or the circular arc radius), two geometrical element intersection point or tangent point coordinate values. If the NC system has no tool compensation function, the motion path coordinate value of the tool center should be calculated. For the parts with complex shapes (such as the parts composed of non-circular curves and surfaces), it is necessary to approximate the actual curves or surfaces with straight lines (or arcs), and calculate the coordinate values of their nodes according to the required machining accuracy.
3. Write part machining program
According to the processing route to calculate the tool movement trajectory data and the determined process parameters and auxiliary movements, programmers can be used in accordance with the numerical control system provisions of the functional instructions and program segment format, segment by segment to write the parts of the processing program. Attention should be paid to: First, the writing of the program should be standardized, and it should be easy to express and communicate; Second, on the basis of fully familiar with the performance of the CNC machine tools and instructions, the use of the instructions of the skills, programming skills.