Helical Point Micro Drill Manufacture And Its Drilling Experimental Research

With the development of technology and market demand, the application of micro-components and micro-machine are increasing. The micro-hole which diameter is smaller than 1mm has been widely used in modern industry in various aspects, such as nozzle, mold, circuit board and other key components. Micro-hole machining process is one of the most difficult processing technologies. The size of micro-components is getting more and more smaller which cause many new problems in manufacturing of micro-components. In order to solve these problems, micro-cutting technology develops in recent years. Micro-drill mechanism, manufacture, micro-drilling performance and processing quality control in the micro-drilling technology are all the important issues in micro-drilling technology research. This research takes cemented carbide helical point micro drilling tool mechanism, micro-hole processing technology and nozzle spray hole drilling application as research object. Micro-drilling fundamental theories, micro-drill mathematical models, tool grinding, micro-drilling processing and nozzle spray hole drilling technology are extensively studied in this article. The main research contents are listed as follows:1. Based on single-edge oblique cutting model and the minimum cutting energy, cutting lip force model and chisel edge force model are established. By the simulation of chip’s forming using deform3 D, the tool wear and the distribution of cutting temperature are easily analyzed; Characteristics and influencing factors of the tool wear and the mechanism of micro-burr formation are studied by drilling experiments.2. The mathematical models of helical point and flute of the drill are advanced by grinding method and the engagement principle between grinding wheel and micro-drill. Micro-drilling grinding based on mathematical model of drilling bit coordinate system, drill flank can be discrete into a series of contact lines getting through the twist axes and the drilling bit outer edge points, then the flank grinding model is build based on the contact lines of grinding wheels and drilling bit. Micro-drill grinding method and every stage of the micro drill manufacture of grinding control processes are systematically studied. Micro drill manufacture is achieved by the motion of grinding machine and bar stock in grinding process which is based on grinding method.3. The effect of process parameters and structure of micro-drill on drilling thrust, the entry burrs and exit burrs size and quality of hole wall surface has been studied. The effect of feed on burr size was bigger than spindle speed on drilling thrust and entry burrs and exit burrs size. The point angle is the main influence factor on drilling thrust, the entry burrs and exit burrs size and quality of hole wall surface.4. From the aspects of micro drilling and cutting process parameters principles, part locating feature and inclined-hole processing method, the realization of the spray nozzle hole machining method is studied. On the basis of the processing equipment to make process plan, based on micro drilling experimental data, reciprocating vibration cutting method which is used for chip removal and heat dissipation can improve machining efficiency. Through drilling experiment the feasibility of this method of processing is verified.