The invention discloses a
processing method of a fuel valve hole of a marine
diesel engine cylinder cover, comprising the following steps: a right-angle bent plate on a work bench is corrected, a marine
diesel engine cylinder cover is fixed on the right-angle bent plate, and then the preset position of a fuel valve hole is drawn; the work bench alpha is vertically rotated, an upward hole is processed by three drills, and then heavy boring and finish boring are carried out; a model drilling body is put into the upward hole, the distance between the model drilling body and the upward hole is h, and a downward hole is processed by a common lengthening
drill; the model drilling body is taken out to be put into a bush, parts of middle holes with the distance of d are axially milled by an expanding
milling cutter, then a cutter is retreated to take the bush out, and a depth measuring tool is put in to measure residual depth; the depth measuring tool is retreated, then the bush and the expanding
milling cutter are put in to mill residual depth so as to mill the middle hole; the cylinder cover on the right-angle bent plate is loosened, and is fixed after rotating; the above steps are repeated to process the residual two fuel valve holes. The above
processing method has low
processing cost, high quality of processing finished products, short processing time and low processing difficulty.