Drilling tool capable of rotating

Abstract

The invention discloses a drilling tool capable of rotating. The drilling tool capable of rotating comprises a tool body, an outer blade and an inner blade, the outer blade is arranged in a circumferential groove and is used for machining a hole outer ring area, the inner blade is arranged in a center groove and is used for machining a hole center area, and the inner blade consists of a first upper surface, a first lower surface and a first side surface which is surround by the first upper surface and the first lower surface; and the first upper surface and the first side surface intersect toform a plurality of identical inner cutting edges, when in drilling machining, a cutting area of the inner cutting edges serving as a main cutting edge is located between middle inner points and middle outer points on the inner cutting edges, in a feeding direction of the drilling tool capable of rotating, an inner convex cutting part with the largest cutting depth is arranged between the middle outer points and the middle inner points, the distance between the middle inner points and the inner convex cutting part and the distance between the middle outer points and the inner convex cutting part in the axial direction of the drilling tool capable of rotating is H1 and H2 correspondingly, and the H1 and the H2 satisfy the condition that H1 is greater than or equal to 0.9H2 and less than orequal to 1.1H2. The drilling tool capable of rotating has the advantages that cutting vibration is small, radial balance capability is high, machining surface quality is good, and size precision is high.

Description

technical field [0001] The invention relates to the technical field of metal cutting, in particular to an indexable drilling tool. Background technique [0002] The cutting edge of the indexable drilling tool is asymmetrical with respect to the central axis. Its cutting part includes two kinds of blades, the inner blade and the outer blade. In the area of ​​material removal, the outer blade completes the removal of peripheral material, while the linear velocity of the cutting edge of the drilling tool increases with the increase of the radius. Therefore, the linear velocity of the central area of ​​the inner blade is close to zero, and the central area of ​​the drilling tool cuts The edge friction is severe, and the material removal amount of the cutting edge adjacent to the peripheral surface of the cutter body is much larger than that of the center. In order to meet the requirements of different cutting conditions of the inner and outer blades, in the prior art, the inner ...

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Problems solved by technology

[0002] The cutting edge of the indexable drilling tool is asymmetrical with respect to the central axis. Its cutting part includes two kinds of blades, the inner blade and the outer blade. In the area of ​​material removal, the outer blade completes the removal of peripheral material, while the linear velocity of the cutting edge of the drilling tool increases with the increase of the radius. Therefore, the linear velocity of the central area of ​​the inner blade is close to zero, and the central area of ​​the drilling tool cuts The edge friction is severe, and the material removal amount of the cutting edge adjacent to the peripheral surface of the cutter body is much larger than that of the center. In order to meet the requirements of different cutting conditions of the inner and outer blades, in the prior art, the inner and outer blades usually have different structures or It has the same structure but adopts different installation dimensions. Although the combination of wear and impact resistance of the inner blade and outer blade can be improved to a certain extent through the above structure, due to the independence of the inner and outer blades installed on the cutter body, As a result, when the inner and outer blades participate in the cutting, the radial force of the tool is difficult to balance, and the unbalanced cutting force is likely to generate cutting vibration, which not only reduces the quality of the machined surface and the dimensional accuracy of the hole, but also makes the indexable drilling tool greatly reduced lifespan

[0003] In order to achieve a certain balance between the radial cutting forces of the inner and outer blades, in the prior art, by changing the cutting width of the inner and outer blades and distributing the inner and outer blades at an asymmetrical phase angle in the circumferential direction of the cutter body, thereby The cutting force of the inner and outer blades is distributed reasonably in the radial direction. However, in order to ensure the cutting stability of the inner and outer blades when they cut into the workpiece during the drilling process, the main cutting edges of the inner and outer blades do not cut into the workpiece at the same time, but The radial balance of the inner and outer blades is not only affected by the cutting force but also directly related to the degree of inclination of the inner and outer blades; more importantly, because the wear of the inner and outer blades is not synchronized, the wear Asynchronous changes of the blade may also upset the balance between the inner and outer blades

Radial balance refers to the dual radial balance of radial balance in the cutting plane and radial balance in the end plane. Due to the complex structure of the blade, the cutting line speed difference between the inner and outer blades is large, and the radial balance of the cutting plane and the end plane affects each other. It is very difficult to ensure the radial force balance of the cutting and end plane of the drilling tool. Although the above-mentioned technical means can theoretically solve the radial balance problem of the inner and outer blades, due to the shape of the cutting edge and the inclination angle of the inner and outer blades , Installation angle and rake angle are different in structural size. In the actual processing process, it is difficult to realize the radial force balance between the inner blade and the outer blade, so that cutting vibration is easy to occur during cutting, resulting in a large deviation in the diameter of the processed hole. The quality of the machined surface is poor, and the inner and outer blades are prone to chipping

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