Study On New Drilling Force Model Of Vibration Drilling And Vibration Drilling With Invariable Parameter And Variable Parameter

With the development of science and technology, more and more high-technology products have been turned out. Holes have been widely used in aerospace and astronautics, automobile, mechanical engineering, and other manufacturing industry. There are many unconventional machining technologies to make holes, such as Electronic Discharge Machining (EDM), Ion Beam Machining (IBM), Laser Beam Machining (LBM), etc., which are different in the mechanics. But the application of those methods is limited by the workpiece material, required precision, productivity, production cost, and can't be widespread availability.At the present time, the method, which is extensive used and have the powerful practicability, still is drilling. But the conventional drilling can't meet the new requirements because of the bad hole quality, the low efficiency. Furthermore, more and more investigations on vibration drilling have indicated that as a new drilling technology, vibration drilling not only can decrease the cutting force but also improve the machine performance. The vibration drilling presents its predominance and arouse the interest of scholars. Vibration drilling as an unconventional machining technology is based on the vibration cutting theory. In vibration drilling, vibration unit will produce a controllable relative vibration between the drill and the workpiece. The vibration drilling mechanics is different from conventional drilling. According to the properties of workpiece material, some variation parameters vibration drilling methods are appeared, which is first proposed by Professor Wang Li-jiang and became a new subject of vibration drilling research field. The variation parameter vibration drilling include the following method: varying parameters vibration drilling in three-segment for one kind material, the multiple variation parameter vibration drilling for laminated materials, the hybrid variation parameters vibration drilling for fiber reinforced composite materials.The project had been supported by National Natural Science Foundation of China. In the paper, the dynamics axial cutting thickness, cutting graphics, the number of intersect curve are introduced, a concept of cutting time ratio is presented, which is the ratio of cutting time to the vibration cycle. Two new parameters ?f and E are used in the analysis, which reflect the relationship between A and f, F and n. By the analysis and calculate of the computer program, it is found that the relation curve between K and ?f is periodic, symmetrical and having many peak values. The cycle is 2 and the symmetry axis is odd number in one cycle. In on cycle, the number of peak increasing with the E. In the analysis of dynamics cutting angle, the following phenomenon is discovered first time: the minimize of dynamics clearance angle is not monotone decreasing with the vibration frequency (or ?f ) , and appear peak value periodically, which exist is the disseparation region and approach the separation region. The phenomenon is caused by the variation velocity property of vibration drilling. The regularities of cutting time ratio can be used to adopt appropriate parameters in vibration drilling to get good drilling results. Because vibration drilling include low frequency and high frequency vibration, the range of the vibration frequency can be used in drilling is wide, by adopting appropriate rotate speed of the drill at a frequency, the zones that K is smaller can be easily found. Chip evacuation is a distinguishing characteristic of drilling that separates if from other metal cutting processes because the chips are confined by the hole wall. In the paper, the drilling force is decomposed as the cutting force and the chip-evacuation force. The cutting force reflects that is required for chip formation, it is considered to be constant. The chip-evacuation force means that is required for move the increasing amount of chips that fill the flute out of hole, it increase with the drilling depth, and make the drill broken. The drilling force models had been made before...