Anti-seismic five-edge integral hard alloy drill bit
By designing a five-bladed integral carbide drill bit, employing a spiral cutting edge, a double-beveled drill tip structure, and a specific coating, the problems of large vibration and short lifespan of traditional drill bits in the machining of high-hardness materials are solved, achieving high-precision and high-efficiency deep hole machining.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-10
- Publication Date
- 2026-03-20
AI Technical Summary
Traditional drill bits are prone to vibration when machining high-hardness materials, resulting in high hole wall roughness, large fluctuations in vibration amplitude, short service life, and difficulty in achieving high-precision machining.
A five-flute integral carbide drill bit is designed, which adopts five helical cutting edges and a double-beveled drill tip structure, combined with a fine-grained Al2O3 coating and a nano-columnar MT-TiCN coating to enhance rigidity and suppress vibration.
It effectively reduces cutting vibration, improves machining accuracy and lifespan, enhances hole surface accuracy to Ra14, and hole bottom accuracy to H7, saving reamer and labor costs and increasing machining efficiency.
Smart Images
Figure CN224011293U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to drill bit technical field, specifically, relates to a five-blade integral hard alloy drill bit of shock resistance. BACKGROUND
[0002] In the field of mechanical processing, the vibration suppression capability of a drilling tool is a key factor affecting the quality of deep hole processing. The traditional two-blade drill bit is prone to cutting vibration when processing high-hardness materials above HRC50 due to the small number of cutting edges and the thin core thickness, resulting in a generally higher Ra value of the hole wall surface roughness than 2.0 μm. In particular, when processing short chip materials such as ductile cast iron, the existing two-blade drill bit is prone to chip jamming due to the narrow chip removal channel, further exacerbating the vibration phenomenon, and even leading to tool collapse failure in severe cases.
[0003] In the existing improvement scheme, although a four-blade structure is used to improve the rigidity of the tool, the rigidity improvement brought by the multi-blade structure is offset by the unreasonable core thickness parameter, and low-frequency vibration with an amplitude of 0.15 mm still occurs when processing HRC55 quenched and tempered steel. The stress on each cutting edge is uneven, the vibration amplitude fluctuates greatly under intermittent cutting conditions, the service life is short, and the precision requirement of drilling instead of reaming cannot be met.
[0004] In summary, the five-blade integral hard alloy drill bit of shock resistance is provided to solve the above problems. SUMMARY
[0005] The utility model provides a five-blade integral hard alloy drill bit of shock resistance, which solves the problems of large vibration amplitude fluctuation of the drill bit and short service life.
[0006] The technical scheme of the utility model is as follows: a drill bit body is provided, characterized in that: the drill bit body is in a cylindrical straight shank structure, five spiral cutting edges are arranged in an array around the front end of the drill bit body, the core thickness of the spiral cutting edges is 52%-58% of the diameter of the drill bit body, the rake angle of the spiral cutting edges is 8-12°, the spiral angle of the spiral cutting edges is 18-22°, a chip removal groove is formed between adjacent spiral cutting edges, the spiral cutting edges and the chip removal groove are connected through a transition arc, any spiral cutting edge is in a double-inverted-edge drill tip structure, and a plurality of double-inverted-edge drill tip structures are connected at one end to form a cutting tip.
[0007] As a preferred technical scheme of the utility model, the groove depth of the chip removal groove is 18%-22% of the diameter of the drill bit body, and the groove width of the chip removal groove is 0.28-0.35 times the diameter of the drill bit body.
[0008] As a preferred embodiment of this utility model, the double-beveled drill tip structure includes a first beveled surface and a second beveled surface, wherein the angle between the first beveled surface and the axis of the drill bit body is 25°-35°, and the angle between the second beveled surface and the axis of the drill bit body is 45°-55°.
[0009] As a preferred embodiment of this invention, the included angle of the cutting tip is 120°.
[0010] As a preferred embodiment of this utility model, the radius of the transition arc is 0.8-1.2mm.
[0011] As a preferred technical solution of this utility model, the spiral cutting edge is provided with a coating, which is a fine-grained Al2O3 coating and a nano-columnar structure MT-TiCN.
[0012] The working principle and beneficial effects of this utility model are as follows:
[0013] This drill bit features a five-helix cutting edge design with a double-beveled tip structure, which reduces vibration during cutting. It is suitable for deep hole machining of hard and short-chip materials. The core thickness of this five-flute drill bit can reach 55% of the drill bit body diameter, which is much greater than that of a two-flute drill bit, resulting in better rigidity and faster cutting speed. The surface finish of the machined hole is improved from Ra2.0 of a two-flute drill bit to Ra14, and the bottom finish can reach H7. It realizes drilling instead of reaming, resulting in longer tool life in the machining of high-hardness materials, saving the cost of a set of reamers and manual tool changing, and making the machining more efficient and stable. Attached Figure Description
[0014] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0015] Fig. 1 This is a schematic diagram of the structure of this utility model;
[0016] Fig. 2 This is a schematic diagram of the structure of the spiral cutting edge of this utility model;
[0017] In the figure: 1. Drill bit body; 2. Helical cutting edge; 3. Chip removal groove; 4. Transition arc; 5. Double chamfered drill tip structure; 51. First chamfered surface; 52. Second chamfered surface; 6. Cutting tip. Detailed Implementation
[0018] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this utility model. Example
[0019] like Figs. 1-2 As shown, this embodiment proposes a shock-resistant five-flute integral carbide drill bit, including a drill bit body 1. The drill bit body 1 is made of K40 carbide, with a hardness of 92HRA and a bending strength of 2250N / mm2. The drill bit body 1 has a cylindrical straight shank structure. Five helical cutting edges 2 are distributed in a circumferential array at the front end of the drill bit body 1. The core thickness of the helical cutting edges 2 is 52%-58% of the diameter of the drill bit body 1, preferably 55%. The rake angle of the helical cutting edges 2 is 8-12°, preferably 10°, and the helix angle of the helical cutting edges 2 is 18-22°, preferably 20°. Chip removal grooves 3 are formed between adjacent helical cutting edges 2, and the groove depth of the chip removal grooves 3 is equal to the diameter of the drill bit body. The diameter of the drill body 1 is 18%-22%, preferably 20%. The width of the chip removal groove 3 is 0.28-0.35, preferably 0.32, to the diameter of the drill body 1. The helical cutting edge 2 is connected to the chip removal groove 3 by a transition arc 4 with a radius of 0.8-1.2 mm. Each helical cutting edge 2 has a double-beveled drill tip structure 5. One end of multiple double-beveled drill tip structures 5 is connected to form a cutting tip 6. The double-beveled drill tip structure 5 includes a first beveled surface 51 and a second beveled surface 52. The angle between the first beveled surface 51 and the axis of the drill body 1 is 25°-35°, and the angle between the second beveled surface 52 and the axis of the drill body 1 is 45°-55°. The cutting tip 6 has an angle of 120° for accurate positioning.
[0020] After multiple cutting tests with rake angles of 10°, 15°, and 20°, helix angles of 20°, 30°, and 40°, and core thickness ratios of 45%, 50%, and 55%, the cutting edge wear was minimized when machining HRC55 quenched and tempered steel with a helix angle of 20°, a rake angle of 10°, and a core thickness ratio of 55%, while maintaining the same number of machined holes.
[0021] The spiral cutting edge 3 is coated with a fine-grained Al2O3 coating and a nano-columnar structure MT-TiCN. This effectively reduces cutting resistance, inhibits the formation of built-up edge, and ensures stability during machining.
[0022] The drill bit is combined by five spiral cutting edges 2, and the spiral cutting edges 2 are also provided with double chamfered drill tip structures 5, so that the vibration during cutting is reduced, the drill bit is suitable for deep hole machining of hard materials and short chip materials, the core thickness of the five-blade drill bit can reach 55% of the diameter of the drill bit body 1, greatly exceeding the two-blade drill bit, the rigidity is better, the cutting speed is faster, the hole surface precision after machining is improved from Ra2.0 of the two-blade drill bit to Ra14, the hole bottom precision can reach H7, the drill bit is used instead of the reamer, the tool life is longer in high-hardness material machining, a set of reamer and the cost of manual tool changing are saved, and the machining efficiency is higher and more stable.
[0023] The above is only a preferred embodiment of the utility model, and is not used to limit the utility model, and any modification, equivalent replacement, improvement and the like within the spirit and principle of the utility model should be included in the protection scope of the utility model.
Claims
1. A shock-resistant five-flute solid carbide drill bit, comprising a drill bit body (1), characterized in that: The drill bit body (1) has a cylindrical straight shank structure. Five helical cutting edges (2) are distributed in a circular array at the front end of the drill bit body (1). The core thickness of the helical cutting edges (2) is 52%-58% of the diameter of the drill bit body (1). The rake angle of the helical cutting edges (2) is 8-12° and the helix angle of the helical cutting edges (2) is 18-22°. Chip removal grooves (3) are formed between adjacent helical cutting edges (2). The helical cutting edges (2) and the chip removal grooves (3) are connected by a transition arc (4). Any one of the helical cutting edges (2) has a double chamfered drill tip structure (5). One end of multiple double chamfered drill tip structures (5) is connected to form a cutting tip (6).
2. The shock-resistant five-flute solid carbide drill bit according to claim 1, characterized in that, The depth of the chip removal groove (3) is 18%-22% of the diameter of the drill bit body (1), and the ratio of the width of the chip removal groove (3) to the diameter of the drill bit body (1) is 0.28-0.
35.
3. The shock-resistant five-flute solid carbide drill bit according to claim 1, characterized in that, The double chamfered drill tip structure (5) includes a first chamfered surface (51) and a second chamfered surface (52). The angle between the first chamfered surface (51) and the axis of the drill body (1) is 25°-35°, and the angle between the second chamfered surface (52) and the axis of the drill body (1) is 45°-55°.
4. The shock-resistant five-flute solid carbide drill bit according to claim 1, characterized in that, The included angle of the cutting tip (6) is 120°.
5. The shock-resistant five-flute solid carbide drill bit according to claim 1, characterized in that, The radius of the transition arc (4) is 0.8-1.2 mm.