1. The long hole boring represented by the coaxial hole system of the box part is one of the most important contents in metal cutting processing. Although there are still examples of long hole boring by means of boring dies, guide bushes, bench-type milling boring machines, post-supporting long boring bars, or manually correcting workpiece rotation by 180°, in recent years, due to CNC boring and boring machines and machining on the one hand. The use of a large number of centers has greatly improved the coordinate positioning accuracy of various types of horizontal milling and boring machines and the accuracy of table rotation indexing. The long hole boring has been gradually turned by a highly efficient table and turned 180°. The general layout of the machine bed or the mass production and application of the CNC planer-type milling and boring machine, from the machine tool structure, makes the worktable rotate 180° and self-positioning the boring hole, which is almost the only method of boring the long hole on the machine tool.
2. The concentricity error of the vertical feed boring and the influence of the compensation on the concentricity of the boring and boring of the milling boring machine are the same as those of the desktop milling boring machine. It is also the grading error of the table turning 180° and the turning head. The axis d1 of the half long hole that has been twisted before is again coincident with the axis of the boring axis after turning the head and boring the other half hole d2 of the long hole, and the required table movement (x) shifts the positioning error dx2 of Lx=2lx. And before and after the table is turned 180°, the inclination error df generated in the xy coordinate plane of the table, the inclination error dy generated in the yz plane, and the translation error dy generated in the y direction, are also the same as the planer milling bed. Shaft degree is an important factor. However, the influence of the spatial position of the axis of the boring axis on the concentricity of the boring hole of the tuner head is usually different from that of the desktop boring and milling boring machine, which is usually used for vertically moving the table.
3. Reasonable determination of the vertical position of the column when the stern shaft is fed
When confronted with a specific situation, the milling and boring machine must fix the column at a suitable position on the longitudinal bed, and when the boring axis is used to extend the tool as the feeding mode of the boring, the axis of the boring axis and the nominal axis of the boring hole are at xz. The intersection angle error db in the plane, the intersection angle error dg in the yz plane, as well as the desktop milling and boring machine, has an important influence on the concentricity of the boring hole of the tune head, and with the increase of the feed length of the boring axis, the reciprocating axis weight Caused by the lower deflection of the mast, it also has a greater impact on the coaxiality of the boring hole. Unlike table-type milling and boring machines, when the boring axis of the boring mill is extended out of the boring hole, the longitudinally movable column must be fixed on the longitudinal bed to a certain position, and it is important that this position can and should be select.
4, the reasonable position of the tool on the boring
When the boring machine is used to feed the boring head in the boring machine, the boring tool mounted on the arbor of the boring shaft has a reasonable position along the Z direction. On the one hand, the distance from the slewing center of the tool nose to the front end surface of the spindle box is slightly greater than Half of the full length of the hole (the youngest will not be able to open the long hole, if it is too large, the rigidity of the 镗 axis will decrease); on the other hand, the rotation center of the tool tip should be satisfied at the intersection of the axis of the 镗 axis and the vertical movement line of the column. O and so on.