Programming and processing of shaft parts

According to the shown below for turning parts, materials for 45 # steel, which Ф 85 cylinder is not processed. On the nc lathe to process as follows: cutting Ф 80 mm and 62 mm cylindrical Ф; R70mm cambered surface, cone, relief groove, thread and chamfering. Requirement analysis process and craft route, writing process. 1. Part drawing process analysis by cylinder, cone, the workpiece surface along the arc, reverse, double thread surface composition, etc. Where multiple diameter size has a strictly the dimensional precision of surface roughness requirements; The size of the spherical S phi 50 ㎜ tolerance also have control of the spherical shape ( Contour of) The effect of error. Dimensioning and complete outline description clearly. Parts material for 45 steel, no heat treatment and hardness requirements. Through the above analysis, can use the following process measures. (1) the pattern on the given several points of high dimension accuracy requirement, because of its less tolerance value. So don't have to average at programming, and all take its basic size. The essay on the outline curve, there are three place for quadrant circular arc, two of them in both a quadrant and change the direction of feed contour curve, so should be mechanical clearance compensation when processing, to ensure the accuracy of the contour curve. (3) to facilitate the clamping, the left should be ware car out of the clamping part (in advance A double dotted line part) , the rough turning out right end should be first and good center hole drilling. Blank choose phi 60 ㎜ bar. Parts of the locating datum and the clamping way sure axis and the left end face (ware Design basis) For the locating datum. Left with three jaw self centering chuck centering clamp, the right end using activity top bearing way of clamping. Select equipment according to the machining parts shape and material conditions, choose TND360 numerical control lathe. Determine the machining sequence and feed line sequence from coarse to fine, from far to near ( From right to left) The principle of certain. Which made rough car (first from right to left Leave a 0. 25 ㎜ fine car allowance) Fine cars, and then from right to left, the last thread cutting. TND360 numerical control lathe with functions of coarse car circulation and thread loop, as long as the proper use of programming instructions, machine tool numerical control system can automatically determine the feed line, as a result, the parts of coarse car circulation and thread loop does not need artificially determine its feed line ( But finish turning feed line for sure) 。 The choice of cutting tools (1) choose phi 5 ㎜ center drill hole drilling center. (2) rough turning and flat end selects 90 ° starboard carbide knives, to prevent the deputy cutter surface and the workpiece contour after intervention ( Can examine graphic method) , deputy Angle shoulds not be too small, choose '= 35 k r & ordm; 。 (3) car select 90 ° starboard carbide knives, threading choose carbide threading tool outside 60 °, outline point arc radius should be less than the minimum radius, r = 0. 15 ~ 0. 2㎜。 Fill out the tool parameters of the selected into the nc machining tool card ( As shown in table 1 1) The selection of cutting parameter (1) the amount of turning: outline coarse car circulation when choose the ap = 3 ㎜, fine car ap = 0. 25㎜； Thread rough turning loop selected ap = 0. 4 ㎜, fine ap = 0. 1㎜。 2 spindle speed choice: car diameter and circular arc, look-up table to choose rough turning cutting speed vc = 90 m/min fine car the cutting speed vc = 120 m/min and then using the formula of vc = PI dn / 1000 technology spindle speed n ( Rough turning diameter D = 60 ㎜, precision lathe pieces of average diameter) ; Coarse car 500 r/min jing 1200 r/min. When threading, reference type spindle speed n = 320 r/min (3) the selection of feed speed look-up table per turn feeding coarse and fine models, then according to the actual situation of processing rough turning each feeding to 0. 4 ㎜ / r, fine car turn each feeding to 0. 15 ㎜ / r, according to the formula Vf = nf rough turning, the feed speed, respectively is 200 m/min and 180 m/min. Front, comprehensive analysis of the content, and fill in the table 1 2 the nc machining process card shown in this table is the main basis of processing program and operators cooperate with CNC program in nc machining of guidance documents. Main content includes: steps work order, work content, the step of cutting tool and cutting parameter, etc.