Method of machining of cam shaft holes of rack of marine diesel engine

Abstract

The invention discloses a method for machining cam shaft holes of a rack of a marine diesel engine. The cam shaft holes comprise the cam shaft hole which is difficult to bore smoothly, a normal gap exists between one side of the cam shaft hole which is difficult to bore smoothly and the adjacent cam shaft hole, a narrow gap exists between the other side of the cam shaft hole which is difficult to bore smoothly and the adjacent cam shaft hole, and a boring tool can not enter the narrow gap. The method for machining the cam shaft holes of the rack of the marine diesel engine is characterized in that a pre-bored hole with a diameter small than a design diameter is firstly bored in the adjacent cam shaft hole separated from the cam shaft hole difficult to bore smoothly by the normal interval, a step hole with a diameter slight larger than that of the pre-bored hole and still small than the design diameter is bored reversely, then the center deviation between the pre-bored hole and the step hole is measured through a dial indicator, centre zero position correction of the boring tool used for reverse boring is conducted, and finally the rest of the cam shaft holes are bored reversely so that the shaft holes can be in the design size. According to the method for machining the cam shaft holes of the rack of the marine diesel engine, the coaxiality between smoothly-bored holes and the reversely-bored holes is guaranteed, and the cam shaft hole machining accuracy is improved; the machining time is shortened, and machining efficiency is improved.

Description

technical field [0001] The invention relates to the processing of marine diesel engines, in particular to a method for processing a camshaft hole of a marine diesel engine frame, and belongs to the technical field of diesel engines. Background technique [0002] The frame of the in-line medium-speed marine diesel engine is structurally different from the V-type medium-speed frame. In the processing of this in-line medium-speed machine, the processing of the camshaft hole is undoubtedly one of the most difficult points. The total length of the frame is 5730mm (take a 9-cylinder engine as an example), and there are 11 gear camshaft holes on both sides. The coaxiality between the bearing hole and the camshaft holes on both sides is required to be within 0.10mm, the gear opening in the camshaft hole is small, and the length of the first gear camshaft hole at the fuel cam is longer, about 220mm. [0003] Since the camshaft holes of this model are close to both ends, please refe...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, and to provide a machining method for the camshaft hole of the frame of a marine diesel engine, by back-boring a shoulder grid on a camshaft hole that has not been bored to size, Afterwards, use the dial indicator to correct, and then finish boring the remaining camshaft holes, so as to solve the problem that the coaxiality cannot be guaranteed, improve the machining accuracy, and reduce the repeated labor of the operator

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