Mold Surface Injection Grinding Theory and Practice

• Main Authors: HUANG, CHENG-HO, 黃正河
• Other Authors: Lai Hsin-Yi, Chen Cha''o-Knang
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/78227918557829858170

碩士 === 國立成功大學 === 機械工程學系 === 86 === This paper presents a new mold grinding methodology using theabrasives jet grinding technique.The method is a cold workingprocess that possesses some distinct features including theremoval of abrasive cutting heat directly by mixing jet flowand the enhancement of mold surface fatigue strength by theeffect of particles impact on grindng surface.The abrasivejet grinding technique utilezes the kinetics embeddedin thepressured mixing jet and the generated material removal pursiveforces on the mold surface to improve surface quality.The grinding particles in the mixing jet impose relatively higher pressure on the surface surrounding the peak andrelatively lower pressure difference tends to remove unevenrough surface and thus enhance the surface quality gradually.By adjusting the jet velocity,flow pressure,and the inclinationangle of the jet,the quality of the mold surface can be welloptimized and controlled.The proposed method possessesmany advantages that are shared by other grindingmethods.These include the independence of the shapecomplexity of the mold surface,the wide range of grindingzone,and the possibility of automation for the process. The paper establishes analytical basis for both the simulationof the jet grinding mechanics and the planning ofregenerative trajectory in grinding kinematics.The bestworking range of key grinding parameters and associatedflow dynamics are estimated based on the analytical-numericalresults.A corresponding abrasive jet grinding system,includingthe pressured mixing subsystem,the jet propulsive system,thegrinding trajectory generation platform and the CNC feed andspin control subsystem, is thus designed and constructedaccordingly.The system is then employed for grindingillustrations using two predesigned mold surfaces.The results are measured,processed and presentedfor various possible conditions including operationtime,particle sizes,and other operationvariables.The resulting quality of the moldsurface obtained directly from experimentalstudy agrees well with that of analyticalsimulations.The proposed abrasive jet grinding techniqueproposed in this paper shows great potential and cao beused for precision grinding in various industries.