The Modification Of Drill Machine Tool And Reaseach Of Process Technics To Gun Drilling And Gun Reaming

In the thesis,for improving the cutting quality of the connecting rod bolt holes in 6200 diesel engines, the factors influencing it,such as gun drilling-reamed machine tools,clamping fixtures,tools,cutting dosage, cutting solution, have been analyzed .The gun drilling-reamed machine tools and cutting process technique of the gun drilling-reamed holes have been improved .The gun drill bit and gun reamer has been designed .The cutting dosage and cutting solution have been chosen .The cutting quality of the connecting rod bolt holes has been guaranteed .The key technics have been solved in the factory production.The reasons have been found that the surface roughness of the connecting rod bolt holes wasn't the certificate of quality and the perpendicularity between the bolt holes and the connecting face in the connecting rod was out of the tolerance according to quality analysis.On the basis of the cutting theory ,the geometric parameters of the gun drill bit have been designed. The design of the two guiders in the gun drill bit should assure that the cutting radial composite force acts to the guiders and the pressure per unit area of two guiders is equal. The material of the gun reamer blade should meet the good abradability , the high cutting speed and the precision retentivity. The geometric parameters of the gun reamer have been designed and optimized according to gun reamed cutting character and cutting accuracy. The cutting speed and feed amount have been determined according to combining computing, look-up table and practical experience. To choose the cutting solution, not only cooling, lubrication, chip removal, and prevention of corrosion should be considered also the roughness of the drilled hole should be considered for the reamed hole process. By analyzing the guide sleeve stress during the cutting , coaxiality between the gyration center of the main arbor and the center of the guide sleeve in the machine tool,gap between the guiders of drill bit and guide sleeve,the method of improving the guide accuracy of guide device have been obtained.