High-precision coaxial hole machining method

Abstract

The invention discloses a high-precision coaxial hole machining method and relates to the field of machining, in particular to a high-precision coaxial hole machining method. The method comprises thefollowing steps that 1, the distance between a machine tool tailstock and a main shaft is adjusted as 3400 mm; 2, a workpiece is arranged in the middle of a workbench and installed and pressed, wherein the longitudinal stroke is 1600 mm; and 3, a boring bar is manufactured, one end of the boring bar is connected with the main shaft, the other end of the boring bar is connected with the machine tool tailstock, the boring bar is provided with a knife installing position, one end of the boring bar is fixedly connected with the main shaft, and the other end of the boring bar is installed in a bearing bush of the tailstock. According to the high-precision coaxial hole machining method, the size precision of a cam shaft hole with the pattern requirement is achieved, and also the coaxiality of the shape-position tolerance requirement is guaranteed, the machining risk of an oil supply unit shell is avoided, the machining cost is reduced, and the processing efficiency is improved. The method issuitable for machining products with high-coaxiality requirements of other similar alignment holes.

Description

technical field [0001] The invention relates to the field of mechanical processing, in particular to a processing method for high-precision coaxial holes. Background technique [0002] The camshaft hole of the housing of the oil supply unit, an important part of the electronically controlled intelligent diesel engine injection system, has a tolerance grade of six; the shape and position tolerance requires a maximum coaxiality of 0.05mm, and the coaxiality between two adjacent holes is 0.025mm . The external dimensions of the shell are 2084mm in length, 1210.5mm in width, and 540mm in height. The axial distance of the six holes to be processed is about 1947 mm. To process the shell, a large CNC machining center is required, and The precision of the machine tool is very high, so it is very difficult to process. [0003] In the traditional machining of the camshaft hole of the housing of the oil supply unit of the diesel engine, due to the long axial distance of the hole, the...

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Problems solved by technology

[0003] In the traditional machining of the camshaft hole of the housing of the oil supply unit of the diesel engine, due to the long axial distance of the hole, the spindle of the machine tool needs to be extended almost to the limit size, and an extended boring bar needs to be designed to process the first three holes, and then the table is rotated 180 degrees, re-align and then process the last 3 holes. In this way, two important factors will affect the size and coaxiality error of the holes: 1) Because the main shaft is too long, the rigidity is weakened, and the lengthening The self-weight of the boring bar will cause the ellipticity error of the hole, and the size is easy to be out of tolerance; 2) If the worktable of the machine tool is tilted, then after rotating 180 degrees, a double error will occur, resulting in the axis of the hole being processed twice. Angle error is formed, it is difficult to guarantee the coaxiality

In summary, there are great risks in the processing methods mentioned above, and a slight negligence may cause the shell to be scrapped, resulting in a great loss