Boring machining

Boring machining requirements boring machining center is the main part of it can precisely guarantee the dimensional accuracy, form and position precision of hole system, and correct the error of process. Through the processing of cylindrical hole boring, most is the main machine parts with hole or bearing hole, so have high dimensional accuracy requirements. Generally with the size of the hole accuracy control in IT7 ~ IT8, machine tool spindle box the size of the hole for IT6 precision, low accuracy of hole general control in IT11. For higher accuracy requirement of bracket holes, sets of parts and the important of parts of the hole, its shape should be controlled in pore size tolerance of precision 1/2 ~ 1/3. Bore hole is apart from the error between the general control in the plus or minus 0. 025-0. 6 mm, two hole axis parallelism error control in 0. 03 ~ 0. 10 mm。 Surface roughness, boring is usually Ra1. 6 ~ 0. 4 μm。 Boring machining method of hole boring boring, often passes half essence boring, boring process. Rough boring, boring, fine boring process of choice, is decided by the accuracy of the boring, the material of workpiece, and the concrete structure of workpiece. (1) thick rough boring boring is an important process of cylindrical hole boring machining, it is mainly the blank hole on the workpiece ( Casting, forging, hole) Or for drilling, enlarge the hole after preprocessing, for the next half fine boring, laying a foundation for fine boring machining requirements, and timely find blank defects ( Crack, sand inclusion, sand holes, etc. ) 。 After rough boring leave unilateral commonly 2 ~ 3 mm allowance as half essence boring and boring. General rough boring for box workpiece precision, also should be arranged after tempering or aging treatment, in order to eliminate the internal stress produced during the rough boring, and then to carry on the fine boring. Due to larger cutting dosage, are used in rough boring reason in rough boring produce big cutting force, cutting temperature, tool wear is serious. In order to ensure that the productivity of rough boring and boring accuracy, therefore requires rough boring cutter should have enough strength, can bear larger cutting force, and has a good impact resistance; Rough boring boring cutter has suitable geometry Angle, to reduce the cutting force, and help the heat dissipation of boring cutter. 2 fine boring half essence is boring boring and preparation process, mainly to solve uneven allowance part of rough boring when left. Hole with relatively high accuracy, fine boring generally divided into two: mainly remove rough boring for the first time leave allowance is not uniform; Second is boring the rest of the surplus, in order to improve the dimensional accuracy and shape of the hole precision and reduce the surface roughness. After half fine boring and generally stay fine boring surplus is zero. 3 to 0. 4 mm( Unilateral) , the accuracy is not high, can be directly after rough boring boring, don't have to set a fine boring process. (3) essence boring boring is on the basis of rough boring and half fine boring, with high cutting speed, smaller feeding, cut to rough boring or half fine boring with less margin, inner hole surface accurately meet requirements in the drawings. After rough boring clamp plate should be loose, clamping, again in order to reduce clamping deformation effects on machining accuracy. Usually fine boring and turning quantity is greater than or equal to 0. 01 mm, feeding is greater than or equal to 0. 05 mm/r。