A drill bit
By designing a multi-dimensional drill bit, the problems of drill bit breakage and poor chip removal in the machining of waist-shaped countersunk holes were solved, thereby improving cutting performance and service life, and ensuring machining stability and accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUIZHOU YUDINGHONG TECH CO LTD
- Filing Date
- 2025-08-01
- Publication Date
- 2026-07-14
AI Technical Summary
In the machining of waist-shaped countersinks, the drill bit is prone to breakage due to the concentration of radial and axial forces, and the problem of poor chip removal is particularly prominent.
Design a multi-dimensional structure drill bit, including a groove at the top axis of the drill bit body, four main cutting surfaces surrounding the groove, and a spiral chip removal groove. Combined with the secondary chip removal groove and auxiliary cutting surfaces, a multi-level chip removal channel is constructed to disperse stress and optimize the cutting path.
It significantly improves the cutting performance and service life of the drill bit, reduces the risk of breakage, enhances machining stability and chip removal efficiency, and ensures the machining accuracy of the waist-shaped countersunk hole.
Smart Images
Figure CN224487749U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of drill bit technology, and more particularly to a drill bit. Background Technology
[0002] In mechanical manufacturing, the oblong countersunk hole is a common connection or assembly structure, widely used in scenarios such as part positioning, fastening, and weight reduction.
[0003] During the machining of waist-shaped countersunk holes, the drill tip bears a large radial and axial force. Excessive stress concentration makes small waist-shaped hole drills more prone to breakage. In addition, due to the enclosed space characteristics of waist-shaped countersunk holes, chip removal is a common problem, which places high demands on the chip removal capability of the drill bit. Utility Model Content
[0004] The purpose of this application is to provide a drill bit to solve at least one of the above-mentioned technical problems.
[0005] To solve the above-mentioned technical problems, this application provides a drill bit, including a drill bit body and a drill shank. A groove is formed at the top axis of the drill bit body. Four main cutting surfaces are formed at equal angles around the groove on the end face of the drill bit body. Four main chip removal grooves are spirally formed around the drill bit body in the direction of the drill bit body toward the drill shank. Each main chip removal groove is connected to a main cutting surface. A secondary chip removal groove and an auxiliary cutting surface are formed sequentially on the main chip removal grooves toward the outer diameter of the drill bit body. The auxiliary cutting surface is connected to the main cutting surface. Both the secondary chip removal groove and the main chip removal groove are connected to the connecting surface.
[0006] In the aforementioned implementation process, the drill bit provided in this application achieves a significant improvement in cutting performance and service life through multi-dimensional structural design, making it particularly suitable for machining complex structures such as waist-shaped countersunk holes. Firstly, the groove at the top axis of the drill bit body effectively disperses stress in the central area of the drill tip, avoiding the breakage problem caused by stress concentration at the axis in traditional drill bits. In machining small waist-shaped holes, it significantly reduces the superposition of radial and axial forces. Secondly, the four main cutting edges are evenly distributed around the groove, ensuring that the cutting force is evenly distributed on the drill bit end face, reducing the load on a single cutting edge, decreasing vibration caused by uneven force distribution, and improving machining stability and hole wall smoothness. Furthermore, in this solution, the four main chip removal grooves are arranged along a spiral direction, combined with secondary chip removal grooves and auxiliary cutting edges distributed sequentially towards the outer diameter, constructing a multi-stage chip removal channel: the main chip removal grooves are responsible for removing chips from the central area, while the secondary chip removal grooves and auxiliary cutting edges divert chips near the hole wall, solving the problem of poor chip removal in the enclosed space of waist-shaped countersunk holes and preventing drill bit overheating and wear caused by chip accumulation. Furthermore, the design of the connection surface between the main chip removal groove and the main cutting edge, as well as the connection between the secondary chip removal groove and the main chip removal groove, ensures smooth transitions between various structures, reducing resistance during the cutting process and further lowering energy consumption and cutting edge wear. The overall structure, through stress dispersion, force balance, and the synergistic effect of multi-stage chip removal, significantly improves the drill bit's fracture resistance and chip removal efficiency, extending its service life while ensuring the machining accuracy of the waist-shaped countersunk hole.
[0007] Preferably, the main cutting surface includes a straight cutting edge and a curved cutting edge, with the straight cutting edge disposed on the side closest to the groove;
[0008] In the above implementation process, the main cutting edge adopts a combination design of straight and curved cutting edges, achieving precise adaptation for different cutting areas in the machining of waist-shaped countersunk holes, significantly improving cutting performance. The straight cutting edge is located near the groove side, which can form a stable cutting trajectory in the center area of the drill bit, ensuring precise cutting of the center part of the countersunk hole and reducing hole position deviation caused by unstable cutting in the center. Due to the high material density and high cutting resistance in the center area of the waist-shaped countersunk hole, the linear structure of the straight cutting edge can provide stronger cutting rigidity, preventing the cutting edge from deforming or cracking under high pressure; the curved cutting edge located on the outer edge provides more cutting strength, which, together with the straight cutting edge, can stably increase the cutting force while ensuring structural strength.
[0009] Preferably, the endpoint of the curved blade is located on the extension line of the straight blade;
[0010] In the above implementation process, the endpoint of the curved cutting edge is located on the extension line of the straight cutting edge. This design achieves the continuity of the main cutting surface cutting trajectory and significantly optimizes the transmission path of cutting force. In the machining of waist-shaped countersinks, the cutting trajectory of the drill bit needs to smoothly transition between the central straight area and the outer curved surface area. If there is a misalignment between the straight and curved cutting edges, a sudden change point in cutting force is easily formed at the connection, leading to stress concentration and accelerated wear of the cutting edge. The design of the endpoint being located on the extension line allows the cutting force of the straight cutting edge to be naturally transmitted to the curved cutting edge in a straight direction, avoiding sudden changes in force and reducing chipping or cracking of the cutting edge due to excessive local stress.
[0011] Preferably, the outer diameter of the groove is 20%-25% of the maximum outer diameter of the drill bit body;
[0012] In the above implementation process, the outer diameter of the groove is set to 20%-25% of the maximum outer diameter of the drill bit body. This proportion precisely balances the structural strength and chip removal efficiency of the drill bit, making it particularly suitable for machining small, waist-shaped countersunk holes. If the outer diameter of the groove is too small, the stress concentration problem in the central area is difficult to alleviate, and the drill bit is still prone to breakage under high loads. If the outer diameter is too large, it will weaken the overall rigidity of the drill bit body, leading to significant vibration during cutting and affecting machining accuracy. The 20%-25% proportion range provides sufficient space in the central area to disperse stress and reduce the risk of drill tip breakage, while ensuring the structural strength of the drill bit body and meeting the rigidity requirements in waist-shaped countersunk hole machining. At the same time, the groove at this proportion can work synergistically with the main chip removal groove to provide an initial channel for chips in the central area, preventing chips from accumulating at the axis. For drill bits of different diameters, this proportion can adaptively adjust the groove size to ensure stable cutting performance even in miniaturized designs.
[0013] Preferably, the outer diameter of the groove is 0.05-0.10 mm;
[0014] In the above implementation process, the outer diameter of the groove is limited to 0.05-0.10mm, achieving precise dimensional optimization for the machining of small drill bits and effectively solving the core pain point in the machining of micro-sized oblong countersunk holes. In micro-machining, the drill bit size is extremely small. In traditional designs, if the outer diameter of the groove is too large, the drill bit body will lack sufficient strength and will not be able to withstand the high cutting stress in the small area; if the outer diameter is too small, it will be difficult to disperse the stress at the axis, which can easily lead to drill tip breakage.
[0015] Preferably, the helix angle of the main chip removal groove is 35°-40°;
[0016] In the above implementation process, the helix angle of the main chip evacuation flute is set to 35°-40°. This angle range achieves an optimal balance between chip evacuation efficiency and cutting resistance, significantly improving the drill bit's continuous machining capability. A helix angle that is too small will result in a steep chip evacuation path, increasing the resistance to chip movement within the flute and making it prone to accumulation and blockage. A helix angle that is too large will increase the contact area between the drill bit and the workpiece, leading to increased cutting torque, accelerated edge wear, and increased energy consumption. A helix angle of 35°-40° creates a smooth and efficient flow channel in the chip evacuation flute, allowing chips to be quickly discharged under the combined action of rotational centrifugal force and helical thrust. This is particularly suitable for the enclosed space environment of oblong countersunk holes, reducing overheating problems caused by poor chip evacuation. Simultaneously, this angle provides better matching between the main chip evacuation flute and the drill bit's rotational speed, maintaining a stable chip evacuation rhythm during high-speed cutting and preventing chips from entangled in the drill bit. Furthermore, a moderate helix angle can reduce radial force during cutting, decrease drill bit vibration amplitude, improve the dimensional accuracy and surface quality of oblong countersunk holes, extend drill bit life, and reduce machining costs.
[0017] Preferably, the length of the main chip removal groove is 4.0mm-6.0mm;
[0018] In the above implementation process, the main chip evacuation groove length is set to 4.0mm-6.0mm. This length design achieves a synergistic optimization of chip evacuation capability and structural strength for machining shallow to medium depth oblong countersunk holes. If the groove length is too short, chips tend to accumulate in the groove during the evacuation process, especially in the enclosed environment of the oblong countersunk hole, leading to poor drill heat dissipation and increased cutting resistance. If the groove length is too long, it will excessively weaken the structural strength of the drill body, making the drill prone to bending or breakage during cutting. The length range of 4.0mm-6.0mm provides sufficient guiding path for chips, ensuring that chips generated in shallow to medium depth countersunk hole machining can be completely discharged, avoiding machining failures caused by accumulation. At the same time, the main chip evacuation groove at this length does not excessively sacrifice the rigidity of the drill, maintaining a stable cutting posture and ensuring the depth and shape accuracy of the countersunk hole. For batch machining scenarios, this design can reduce the number of downtime cleanings caused by chip evacuation problems, improving machining efficiency. In addition, the reasonable groove length can also reduce the friction time between the cutting edge and the chips, reduce wear, extend the drill replacement cycle, and further reduce production costs.
[0019] Compared with existing technologies, the beneficial effects of this application are as follows: The drill bit provided by this application achieves a significant improvement in cutting performance and service life through multi-dimensional structural design, and is especially suitable for machining complex structures such as waist-shaped countersunk holes. First, the groove at the top axis of the drill bit body can effectively disperse the stress in the central area of the drill tip, avoiding the breakage problem caused by stress concentration at the axis of traditional drill bits. In the machining of small waist-shaped holes, it can significantly reduce the superposition effect of radial and axial forces. Second, the four main cutting surfaces are distributed at equal angles around the groove, so that the cutting force is evenly distributed on the end face of the drill bit, reducing the load on a single cutting surface, reducing vibration caused by uneven force, and improving machining stability and hole wall smoothness. In addition, the four main chip removal grooves in this solution are set along the spiral direction, and together with the secondary chip removal grooves and auxiliary cutting surfaces distributed sequentially towards the outer diameter, a multi-level chip removal channel is constructed: the main chip removal grooves are responsible for removing chips from the central area, while the secondary chip removal grooves and auxiliary cutting surfaces divert chips near the hole wall, solving the problem of poor chip removal in the closed space of waist-shaped countersunk holes, and avoiding overheating and wear of the drill bit caused by chip accumulation. Furthermore, the design of the connection surface between the main chip removal groove and the main cutting edge, as well as the connection between the secondary chip removal groove and the main chip removal groove, ensures smooth transitions between various structures, reducing resistance during the cutting process and further lowering energy consumption and cutting edge wear. The overall structure, through stress dispersion, force balance, and the synergistic effect of multi-stage chip removal, significantly improves the drill bit's fracture resistance and chip removal efficiency, extending its service life while ensuring the machining accuracy of the waist-shaped countersunk hole. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the overall structure of a drill bit according to one embodiment of this application;
[0022] Figure 2 This is a schematic diagram of the end face structure of a drill bit according to one embodiment of this application.
[0023] Among them: 10, drill shank; 20, drill bit body; 21, groove; 22, main cutting face; 221, straight cutting edge; 222, curved cutting edge; 23, main chip removal groove; 24, connecting surface; 25, secondary chip removal groove; 26, auxiliary cutting face. Detailed Implementation
[0024] The following drawings disclose several embodiments of this application. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this application. That is, in some embodiments of this application, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.
[0025] It should be noted that all directional indications in the embodiments of this application, such as up, down, left, right, front, back, etc., are only used to explain the relative positional relationship and movement of the components in a specific posture as shown in the attached figure. If the specific posture changes, the directional indication will also change accordingly.
[0026] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit this application. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.
[0027] To further understand the utility model content, features, and effects of this application, the following embodiments are provided, and detailed descriptions are given below in conjunction with the accompanying drawings: Example
[0028] During the machining of oblong countersunk holes, the drill tip bears significant radial and axial forces. Excessive stress concentration makes small oblong hole drills prone to breakage. Furthermore, the enclosed space characteristic of oblong countersunk holes makes chip removal a common problem, placing high demands on the drill bit's chip removal capabilities. To address these technical problems, this embodiment provides the following technical solution:
[0029] For details, please see Figure 1-2 This embodiment provides a drill bit, including a drill bit body 20 and a drill shank 10;
[0030] Specifically, a groove 21 is formed at the top axis of the drill bit body 20, and four main cutting surfaces 22 are formed at equal angles around the groove 21 on the end face of the drill bit body 20.
[0031] Furthermore, four main chip removal grooves 23 are spirally formed around the drill bit body 20 in the direction of the drill bit body 20 toward the drill shank 10. Each main chip removal groove 23 is provided with a connecting surface 24 between itself and the main cutting surface 22. A secondary chip removal groove 25 and an auxiliary cutting surface 26 are sequentially formed on the main chip removal grooves 23 toward the outer diameter of the drill bit body 20. The auxiliary cutting surface is connected to the main cutting surface 22, and both the secondary chip removal grooves and the main chip removal grooves 23 are connected to the connecting surface 24.
[0032] In the above-mentioned solution, the drill bit provided by this application achieves a significant improvement in cutting performance and service life through multi-dimensional structural design, and is especially suitable for machining complex structures such as waist-shaped countersunk holes. First, the groove 21 at the top axis of the drill bit body 20 can effectively disperse the stress in the central area of the drill tip, avoiding the fracture problem caused by the stress concentration at the axis of traditional drill bits, and can significantly reduce the superposition effect of radial and axial forces in the machining of small waist-shaped holes. Secondly, the four main cutting surfaces 22 are evenly distributed around the groove 21, ensuring that the cutting force is evenly distributed on the drill bit end face, reducing the load on a single cutting surface, lowering vibrations caused by uneven force distribution, and improving machining stability and hole wall finish. Furthermore, in this design, the four main chip removal grooves 23 are arranged in a spiral direction, working in conjunction with the secondary chip removal grooves 25 and auxiliary cutting surfaces 26 distributed sequentially towards the outer diameter to construct a multi-stage chip removal channel: the main chip removal grooves 23 are responsible for removing chips from the central area, while the secondary chip removal grooves 25 and auxiliary cutting surfaces 26 divert chips near the hole wall, solving the problem of poor chip removal in the enclosed space of the countersunk hole and preventing drill bit overheating and wear caused by chip accumulation. In addition, the connection surface 24 between the main chip removal grooves 23 and the main cutting surfaces 22, and the connection design between the secondary chip removal grooves and the main chip removal grooves 23, ensure smooth transitions between the various structures, reducing resistance during the cutting process and further reducing energy consumption and cutting surface wear. The overall structure significantly improves the drill bit's fracture resistance and chip removal efficiency through the synergistic effects of stress dispersion, force balance, and multi-stage chip removal, extending its service life while ensuring the machining accuracy of the waist-shaped countersunk hole.
[0033] For details, please see Figure 2 In one embodiment, the main cutting surface 22 includes a straight cutting edge 221 and a curved cutting edge 222, with the straight cutting edge disposed on the side near the groove 21;
[0034] In the above design, the main cutting edge 22 adopts a combination design of straight cutting edge 221 and curved cutting edge 222, which achieves precise adaptation for different cutting areas in the machining of waist-shaped countersunk holes, significantly improving cutting performance. The straight cutting edge 221 is located near the groove 21, which can form a stable cutting trajectory in the central area of the drill bit, ensuring precise cutting of the central part of the countersunk hole and reducing hole position deviation caused by unstable central cutting. Due to the high material density and high cutting resistance in the central area of the waist-shaped countersunk hole, the linear structure of the straight cutting edge 221 can provide stronger cutting rigidity and prevent the cutting edge from deforming or cracking under high pressure; the curved cutting edge 222 located on the outer edge provides more cutting strength, which, together with the straight cutting edge 221, can stably increase the cutting force while ensuring structural strength.
[0035] Specifically, the end point of the curved blade 222 is located on the extension line of the straight blade 221;
[0036] In the above design, the endpoint of the curved cutting edge 222 is located on the extension line of the straight cutting edge 221. This design achieves continuity of the cutting trajectory of the main cutting surface 22 and significantly optimizes the transmission path of cutting force. In the machining of waist-shaped countersinks, the cutting trajectory of the drill bit needs to smoothly transition between the central straight area and the outer curved surface area. If there is a misalignment between the straight cutting edge 221 and the curved cutting edge 222, a sudden change point in cutting force is easily formed at the connection, leading to stress concentration and accelerated wear of the cutting edge. The design of the endpoint being located on the extension line allows the cutting force of the straight cutting edge 221 to be naturally transmitted to the curved cutting edge 222 along the straight direction, avoiding sudden changes in force and reducing chipping or cracking of the cutting edge due to excessive local stress.
[0037] Specifically, the outer diameter of the groove 21 is 20%-25% of the maximum outer diameter of the drill bit body 20;
[0038] In the above design, the outer diameter of the groove 21 is set to 20%-25% of the maximum outer diameter of the drill body 20. This proportion precisely balances the structural strength and chip removal efficiency of the drill, making it particularly suitable for machining small, waist-shaped countersunk holes. If the outer diameter of the groove 21 is too small, the stress concentration problem in the central area will be difficult to alleviate, and the drill will still be prone to breakage under high loads. If the outer diameter is too large, it will weaken the overall rigidity of the drill body 20, leading to significant vibration during cutting and affecting machining accuracy. The 20%-25% proportion range provides sufficient space in the central area to disperse stress and reduce the risk of drill tip breakage, while ensuring the structural strength of the drill body 20 and meeting the rigidity requirements in the machining of waist-shaped countersunk holes. At the same time, the groove 21 at this proportion can work synergistically with the main chip removal groove 23 to provide an initial guide channel for chips in the central area, preventing chips from accumulating at the axis. For drills of different diameters, this proportion can adaptively adjust the size of the groove 21 to ensure stable cutting performance even in miniaturized designs.
[0039] Furthermore, in one embodiment, the outer diameter of the groove 21 is 0.05-0.10 mm;
[0040] In the above solution, the outer diameter of the groove 21 is limited to 0.05-0.10mm, achieving precise dimensional optimization for the machining of small drill bits and effectively solving the core pain point in the machining of micro-sized oblong countersunk holes. In micro-machining, the drill bit size is extremely small. In traditional designs, if the outer diameter of the groove 21 is too large, the drill bit body 20 will lack sufficient strength and cannot withstand the high cutting stress in the small area; if the outer diameter is too small, it will be difficult to disperse the stress at the axis, which can easily lead to drill tip breakage.
[0041] Furthermore, in one embodiment, the helix angle of the main chip removal groove 23 is 35°-40°;
[0042] In the above design, the helix angle of the main chip evacuation groove 23 is set to 35°-40°. This angle range achieves an optimal balance between chip removal efficiency and cutting resistance, significantly improving the drill bit's continuous machining capability. A helix angle that is too small will result in a steep chip removal path, increasing the resistance to chip movement within the groove and making it prone to accumulation and blockage. A helix angle that is too large will increase the contact area between the drill bit and the workpiece, leading to increased cutting torque, exacerbating edge wear, and increasing energy consumption. A helix angle of 35°-40° creates a smooth and efficient flow channel in the chip evacuation groove, allowing chips to be quickly discharged under the combined action of centrifugal force and helical thrust. This is particularly suitable for the enclosed space environment of oblong countersunk holes, reducing overheating problems caused by poor chip removal. Simultaneously, this angle provides better matching between the main chip evacuation groove 23 and the drill bit's rotational speed, maintaining a stable chip removal rhythm during high-speed cutting and preventing chips from entangled in the drill bit. In addition, a suitable helix angle can reduce radial force during the cutting process, reduce the vibration amplitude of the drill bit, improve the dimensional accuracy and surface quality of the waist-shaped countersunk hole, extend the service life of the drill bit, and reduce processing costs.
[0043] Furthermore, in one embodiment, the groove length of the main chip removal groove 23 is 4.0mm-6.0mm;
[0044] In the above design, the length of the main chip evacuation groove 23 is set to 4.0mm-6.0mm. This length design achieves a synergistic optimization of chip removal capability and structural strength for machining shallow to medium depth oblong countersunk holes. If the groove length is too short, chips are prone to accumulate in the groove during the removal process, especially in the closed environment of the oblong countersunk hole, which will lead to poor heat dissipation of the drill bit and increased cutting resistance. If the groove length is too long, it will excessively weaken the structural strength of the drill bit body 20, making the drill bit prone to bending or breakage during cutting. The length range of 4.0mm-6.0mm provides sufficient guiding path for the chips, ensuring that the chips generated in the machining of shallow to medium depth countersunk holes can be completely removed, avoiding machining failures caused by accumulation. At the same time, the main chip evacuation groove 23 at this length will not excessively sacrifice the rigidity of the drill bit, can maintain a stable cutting posture, and ensure the depth and shape accuracy of the countersunk hole. For batch processing scenarios, this design can reduce the number of downtime cleanings caused by chip removal issues and improve processing efficiency. At the same time, the reasonable groove length can also reduce the friction time between the cutting edge and the chips, reduce wear, extend the drill bit replacement cycle, and further reduce production costs.
[0045] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application shall fall within the scope of the technical solution of this application.
Claims
1. A drill bit, characterized in that: The drill bit includes a drill bit body and a drill shank. A groove is formed at the top axis of the drill bit body. Four main cutting surfaces are formed at equal angles around the groove on the end face of the drill bit body. Four main chip removal grooves are spirally formed around the drill bit body in the direction from the drill bit body toward the drill shank. Each main chip removal groove is connected to a main cutting surface. A secondary chip removal groove and an auxiliary cutting surface are formed sequentially from the main chip removal groove toward the outer diameter of the drill bit body. The auxiliary cutting surface is connected to the main cutting surface. Both the secondary chip removal groove and the main chip removal groove are connected to the connecting surface.
2. The drill bit according to claim 1, characterized in that: The main cutting surface includes a straight cutting edge and a curved cutting edge, with the straight cutting edge positioned near the groove.
3. The drill bit according to claim 2, characterized in that: The endpoint of the curved blade is located on the extension line of the straight blade.
4. The drill bit according to claim 1, characterized in that: The outer diameter of the groove is 20%-25% of the maximum outer diameter of the drill bit body.
5. The drill bit according to claim 4, characterized in that: The outer diameter of the groove is 0.05-0.10 mm.
6. The drill bit according to any one of claims 1-5, characterized in that: The helix angle of the main chip removal groove is 35°-40°.
7. The drill bit according to claim 6, characterized in that: The length of the main chip removal groove is 4.0mm-6.0mm.