Parameters Research Of A New Sharpening Method And Digital Prototype Design

Hole processing is an important process in mechanical processing,which accounts for about a third of the total process.The consumption of twist drill used in the process is about 23% of the world tool consumption every year. Many research have been done on twist drill and drilling at home and abroad. The structure of twist drill is complex, by changing the geometric shape to improve the performance of drilling has hundreds. Each kind of shape twist drill have to establish the corresponding mathematical model and calculate its manufacturing and grinding parameters, research the corresponding grinding method, and even develop a special grinding machine.In order to study the grinding of commonly used standard twist drill, the mathematical model of rake face cross section and thickness of the core changes helical curve was established to meet the three dimensional software requirements of the drawing curve equation. And using the drawing curve set up a cone back surface standard twist drill modle with constantly thickness of core changes. And chisel edge angle, outer corner back angle and vertex angle were measured.The cone sharpening method is the most commonly used grinding method for the standard twist dril. In order to overcome the disadvantages of traditional cone sharpening method, this thesis put forward a new cone sharpening method, analyzed the grinding principle and establish a new type of cone sharpening method of mathematical model. And chisel edge angle,back angle,tail clearance angle mathematical results were derived by Matlab,which is an athematical analysis software.The intersection point coordinate value can be get by a straight line unwrapped from a spiral passing the main cutting edge in theory, in that way to calculate the actual point coordinate value on the main cutting edge and the actual point coordinate value with the grinding allowance. And analyzed the influence of the cone sharpening parameters, zenith distance and eccentricity on the grinding results. According to the twist drill vertex angle, back Angle, chisel edge angle and tail clearance angle required, using mathematical analysis software Matlab has solved the grinding parameters, and acquired the common used standard twist drill grinding parameters and grinding results.The main cutting edges of a standard twist drill with cone flank surface are two straight edges. How to sharpen out straight main cutting edges was discussed in this paper for the new cone grinding method. And the parameters eccentricity on the effects of main straight cutting edge was studied also. After the modeling analysis, additional grinding parameters and grinding movement wre proposed,and set up the corresponding additional grinding parameter table.According to the new cone grinding method, the transmission principle and structure wre designed, various parts were modeled in the three dimensional software and assembled to analysis the grinding movement. The feasibility of the new cone sharpening method have been verified by the outer cone grinding wheel both rotation and revolution forming the envelope entities in the grinding movement. And a point on the grinding wheel’s linear velocity and position change rule were acquired by the movement simulation.