Full helicoidal surface Micro-drill web thinning method

Abstract

The process of grinding the chisel edge of small spiral bit includes the following steps: regulating the relative locations of grinding wheel and bit based on the chisel edge grinding coefficient to make the tail gap of the back face in the bit aligned to the grinding wheel, fixing one of the bit and the grinding wheel and making the other move linearly along the axis of the spiral back face until the grinding wheel grinds to the center of the bit to form the second back plane in the tail gap; and turning the bit around its axis by 180 deg to grind one other symmetrical back plane. The process can decrease the sharp chisel edge angle in the bit center, raise the centering capacity of the bit, improve the drilling capacity and drilling performance of the bit.

Description

technical field [0001] The invention relates to a method for grinding the chisel edge of a micro drill bit with a full helical surface, which is a chisel edge grinding method proposed for a micro drill bit with a full helical surface drill tip, and is also suitable for grinding the chisel edge of an ordinary full helical surface drill bit. Background technique [0002] The chisel edge is formed during the sharpening process, and it has a considerable impact on the cutting performance of the drill bit. First of all, when the drill is working, the chisel edge first touches the workpiece, which plays a role of centering, thus affecting the shape, position and dimensional accuracy of the hole; secondly, the axial force generated by the chisel edge accounts for about 50-60% of the drilling axial force. %, thus, affects the life of the drill. In order to improve the cutting performance of the chisel edge, various chisel edge grinding methods are usually used. To sharpen the chis...

AI Technical Summary

Problems solved by technology

However, due to the small size of the micro-drill itself, it is impossible to use the method of grinding the chisel edge of ordinary twist drills and group drills to solve the problem of grinding the chisel edge, and a new method of grinding the chisel edge must be studied

[0003] Full helical drill point flank F 1 and F 2 After sharpening, the chisel edge of the drill tip has a sharp angle of 180° at the drill core tip, which is not conducive to the drilling of the drill bit, and the drill bit is prone to slippage on the surface of the workpiece

In addition, the chisel edge has a large negative rake angle, so there will be strong extrusion with the workpiece during the cutting process

In other words, the centering performance and cutting performance of the chisel edge are not good

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