Bearing set of the mathematical processing part drawing

Programming the origin and in the choice of the cutting point in theory, programming the origin in any position can be chosen. But in fact, the origin of choice inappropriate can make the coordinates of the next computing becomes very troublesome. So, make sure programming coordinate system origin principle has the following points: ( 1) The choice of the origin to facilitate programming coordinate calculation. Try to choose basis points coordinates can directly determine the parts of some special points as the origin of coordinates, can simplify the computing workload, also facilitate inspection program. ( 2) The choice of programming the origin to facilitate the processing of the knife. Because of cutter's purpose is to determine the position of the origin on the blank workpiece programming, finding out that point coordinate values in the machine tool coordinate system, the pattern on the coordinate system is transformed into the machining of the workpiece coordinate system. ( 3) Programming the origin should try to choose on the design basis and design reference for locating datum. This can avoid of benchmark misalignment error, to help ensure machining accuracy. ( 4) Symmetrical parts programming origin should choose in the center of symmetry. Which principle concrete application, depending on the specific situation, on the premise of guarantee quality, according to the convenient operation and high efficiency. About for the parts, the benchmark for their design, the programming origin in parts of the left end face or the right end face and the spindle axis of the intersection point. In cutting point is the point at which the tool post transposition in knife position. Point should be located in the workpiece or external to the fixture, tool changer to rest transposition don't touch the workpiece or other parts, and had certain safety zone. The parts of tool change point in point ( 150200). Place. Feeding trajectory point pattern parameter value calculated according to the processing of parts, according to the set of programming coordinate system, established processing route, and allows the programming error, when calculating the programming data you need. ( 1) The pattern on the size of the tolerance, each size should be by the of which the value of tolerance. Such as phi phi 49. 50 97, 52 take phi phi is 51. 96, 35 in phi phi is 35. 04 ( 2) 15 ° starting point of the cone on the extension cord Z = 2 mm, according to the value of X 15 ° slope is obtained. X = 12 tan15°= 12×0。 268 = 3. 216. Therefore, in the Z = 2 mm on the extension of breakthrough point X = 32 + 2 X 3 X. 216 = 38. 432mm。 ( 3) D: (calculation Kong Xiaoduan cone diameter D - d） / L = 1:20, d = ( 20 d - L） / 20 = ( 20×32- 78). / 20 = 28. 1 mm。 Boring cone hole, the cutting point in its extension, namely the Z = 2 mm, that point X = 32. 1 mm。 ( 4) Processing outside straight thread M45, the size of the columns should be the actual turning to the outside for: D1 = D - 0. 13 p = 45 - 0. 13×1. 5 = 44. 805 mm； Thread the thread bottom diameter should be turning to size is: d1 = D - 1. 25 p = 45 - 1. 25×1. 5 = 43. 125 mm。 ( 5) Other trajectory point coordinates can be directly calculated according to the pattern size.