A twist drill having a special grooved structure and chisel edge thinning structure

Abstract

The invention discloses a twist drill with a special groove structure and a grinding chisel edge structure, which includes a shank and a cutting part that rotates around an axis. The parallel lines of the two main cutting edges are located within the inscribed circle of the drill core. The cutting part is provided with two grooves extending spirally from the front end of the cutting part to the shank for chip discharge, and the cutting part is also provided with grooves respectively connecting the outer peripheral edges of the two grooves. The back of the blade is characterized in that the line between the turning points of the two outer edges of the groove forms a small angle with the line connecting the lowest point of the groove. In a view where the center of the core is the origin, and the line parallel to the profile and passing through the origin is the coordinate axis, the profile is above the coordinate axis. The present invention designs a twist drill with a special groove structure and a grinding chisel edge structure to improve the cutting edge structure and groove profile to increase the processing efficiency and service life of the twist drill.

Description

technical field [0001] The invention relates to the technical field of under-core drills, in particular to a twist drill with a special groove structure and a grinding chisel edge structure. Background technique [0002] At present, there are still some problems in the structure of twist drills. The main cutting edge is long, and the chips formed by drilling are wide. Due to the different chip outflow speeds at each point, the chips are usually in the shape of a wider spiral, and the volume is too large, resulting in poor chip discharge. And the cooling is not enough; the chisel edge is long, which causes a large load during the drilling process of the twist drill, resulting in excessive axial force, resulting in a decrease in drilling efficiency and a decrease in the service life of the twist drill; the rake angle at the outer edge turning point is large, The cutting amount is the largest, resulting in heavy load and fast wear; the design of the groove section is not perfec...

AI Technical Summary

Problems solved by technology

[0002] At present, there are still some problems in the structure of twist drills. The main cutting edge is long, and the chips formed by drilling are wide. Due to the different chip outflow speeds at each point, the chips are usually in the shape of a wider spiral, and the volume is too large, resulting in poor chip discharge. And the cooling is not enough; the chisel edge is long, which causes a large load during the drilling process of the twist drill, resulting in excessive axial force, resulting in a decrease in drilling efficiency and a decrease in the service life of the twist drill; the rake angle at the outer edge turning point is large, The cutting amount is the largest, resulting in heavy load and fast wear; the design of the groove cut-off is not perfect, which makes it difficult to repair certain shapes of cutting edges, and the chips are irregularly formed in the chip flute and not discharged smoothly

[0003] When drilling some materials with good toughness such as stainless steel, the phenomenon of incomplete chip curling and continuous chips often occurs, causing the chips to hit the hole wall and the chip removal in the groove is not smooth, which increases the friction and temperature, which greatly affects the performance of the drill. Service life, processing efficiency and hole wall quality

[0004] The existing groove combined with the existing chisel edge grinding method will cause the twist drill chisel edge and center edge to generate a great cutting force during the drilling process, which will not only affect the processing efficiency, but will also affect some difficult-to-machine materials. It will greatly shorten the life of the twist drill

Images