Twist drill with rake angle correction and its processing method

Abstract

The invention discloses a twist drill with rake angle correction and a processing method. The twist drill comprises a cutting part and a shank part, the front end of the cutting part is provided with a drill tip, and the cutting part is provided with two spirals extending from the drill tip to the shank part Chip flute, the part of the cutting part between the two spiral flutes forms a blade, the front end of the blade is provided with a main land, and the spiral flute is connected with the main land through a rake angle correction surface, and is perpendicular to the main land. In the section of the cutting part, the line connecting the front end point M of the main land and the center O of the blade is the line N, the rake angle correction surface is concave relative to the line N, the rake angle of the rake angle correction surface is γ, and γ is a positive acute angle . The processing method includes the steps of rough grinding, fine grinding with brushes, and grinding the rake angle correction surface. The invention is beneficial to improve the sharpness of the twist drill, reduce the cutting torque of the twist drill, reduce the risk of built-up edge in the drilling process, greatly improve the drilling accuracy and service life, and the brush polishing process can greatly improve the Save the manufacturing cost and production efficiency of twist drills.

Description

technical field [0001] The invention relates to cutting processing, in particular to a twist drill with rake angle correction and a processing method of the twist drill. Background technique [0002] Deep hole machining generally refers to hole machining with an aperture ratio greater than 5. Deep hole machining is a difficult point in drilling. During the drilling process of soft materials (such as aluminum alloys, etc.), machining vibrations are easily generated, resulting in poor straightness and roundness of the machined holes, and even built-up edge. The cutting force increases sharply, the torque increases, and finally the tool is broken and the parts are scrapped. Therefore, chip evacuation and safety are key concerns in deep hole drilling. [0003] like Figure 1 to Figure 4 As shown in the figure, in the process of polishing the spiral groove, the main land 6 on the outer periphery is easily polished by the polishing brush, so that the fillet K (circle K (circle) ...

AI Technical Summary

Problems solved by technology

However, due to the multiple times of grinding with the formed grinding wheel, it takes a very long time to achieve the precision grinding effect of the Ra0.1 mirror surface. One specification product requires two grinding wheels with different particle sizes, and the processing cost is too high. It is not conducive to the mass production of twist drills of different specifications; at the same time, the difference in the profile of two grinding wheels with different grain sizes should not be too large, otherwise the groove shape of the drill bit will change, resulting in a mismatch between the drill tip structure and the groove shape, and the twist drill cannot be used.

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