A fiber-reinforced composite drill bit

Abstract

The present invention relates to the technical field of hole-making processing, and discloses a fiber-reinforced composite material drill bit, including: a shank portion, a cutting portion and a drill tip arranged in sequence. The drill tip is successively provided with a first re-entrant edge and a second re-entrant edge. The first re-entrant edge and the second re-entrant edge are arranged at intervals along the axial direction of the drill tip and are distributed in a vertically staggered manner in the circumferential direction of the drill tip. Through the cutting action of the drill tip and the cutting portion, hole-making processing is performed on the laminated material. Since the first re-entrant edge and the second re-entrant edge are arranged at intervals along the axial direction of the drill tip and are distributed in a vertically staggered manner in the circumferential direction of the drill tip, a fiber-reinforced composite material drill bit is provided, which can achieve hierarchical removal of burrs, improve the processing quality of the composite material, and at the same time ensure the cutting ability of the drill tip and the stability of the processing process, eliminating the phenomena of drill jamming during the drilling process and forward punching when the hole is drilled.

Description

Technical Field

[0001] The present invention relates to the technical field of hole-making processing, and particularly to a drill bit for fiber-reinforced composite materials. Background Art

[0002] New types of reinforced composite materials represented by carbon fiber reinforced composite materials (CFRP) and glass fiber reinforced composite materials (GFRP) have excellent physical and chemical properties such as light weight, high specific strength, high specific stiffness, corrosion resistance, and high temperature resistance. With the continuous development of their production and forming processes, it has accelerated the application of high-performance composite materials in the key technical equipment of China's military, aerospace, shipbuilding, and ocean engineering. The laminated material made of fiber composite and aluminum alloy combines the high strength and high hardness of carbon fiber and the toughness of aluminum alloy, and has been typically applied in components such as the fuselage, wings, flaps, and vertical tails of the latest generation of aircraft.

[0003] In the initial stage of equipment research and development, manual hole-making for drilling has higher flexibility compared to hole-making by machining centers and robotic arms. However, the operational convenience of manual drilling limits the processing efficiency of manual hole-making. In addition, since manual drills cannot ensure stable cutting processing parameters, defects such as hole cracks and hole wall scratches are likely to occur during the processing, which greatly reduces the performance of components and even leads to component scrapping. Therefore, the structural design of high-performance and high-quality manual hole-making drill bits for composite materials and laminated materials is of great significance.

[0004] The development of materials has simultaneously brought challenges to the development of processing technologies and processing tools. Many scholars and experts have carried out relevant development and applications on processing tools for fiber composites and laminated materials. The "manual drill bit with a back-hook edge" proposed by Jia Zhenyuan et al., patent application number 201811199427.3, involves an optimized design of double apex angles to reduce the axial force during drilling, and adopts a back-hook edge structure to suppress delamination, burrs, and tearing damage at the entrance and exit during CFRP processing, which can meet the high-quality and high-efficiency requirements of CFRP manual hole-making. The "Tool and Method for Processing Laminated Materials" proposed by Jeroen Heus, patent application number 201580006976.2, involves a tool for processing laminated materials. The cutting edge is segmented, with small cutting grooves distributed in a spiral pattern on the front cutting edge, and the rear cutting edge has a variable helix angle structure. The two cutting edges can achieve adaptive processing of different materials in the laminated material during processing.

[0005] In the prior art, while improving the physical and chemical properties of materials, it also leads to an increase in the difficulty of cutting processing. Due to the differences in the properties of the microscopic reinforcement phase and the matrix phase of fiber-reinforced composite materials, processing is prone to machining damages such as delamination, tearing, and burrs. For laminated materials, due to the obvious processing interface, it exacerbates the wear of the cutting tools for fiber-reinforced composite materials on this basis. At the same time, during the processing of the material interface, phenomena such as pre-drilling rush and drill jamming are extremely likely to occur, posing challenges to the stability and processing quality of manual hole-making.

[0006] The above structural design of the tool can meet the basic processing requirements of CFRP and laminated materials. However, with the diversification of equipment materials, the original structure has certain limitations when applied to the processing of new fiber composite materials and laminated materials such as CFRP-aluminum alloy laminated materials, and its adaptability to manual hole-making and the stability of the processing process also need to be improved urgently.

[0007] Therefore, how to provide a fiber-reinforced composite material drill bit to eliminate the drill jamming phenomenon during the drilling process and the pre-drilling rush phenomenon when drilling holes has become a technical problem to be solved urgently. Summary of the Invention

[0008] The technical problem to be solved by the present invention is how to provide a fiber-reinforced composite material drill bit to eliminate the drill jamming phenomenon during the drilling process and the pre-drilling rush phenomenon when drilling holes.

[0009] To this end, according to the first aspect, an embodiment of the present invention discloses a fiber-reinforced composite material drill bit, including: a shank portion, a cutting portion, and a drill tip arranged in sequence. The drill tip is successively provided with a first re-entrant edge and a second re-entrant edge. The first re-entrant edge and the second re-entrant edge are arranged at intervals along the axial direction of the drill tip and are distributed in a vertically staggered manner in the circumferential direction of the drill tip. Through the cutting action of the first re-entrant edge and the second re-entrant edge, fiber-reinforced composite materials such as CFRP materials can be cut. Since the first re-entrant edge and the second re-entrant edge are arranged at intervals along the axial direction of the drill tip and are distributed in a vertically staggered manner in the circumferential direction of the drill tip, they can cut at different positions respectively, which is different from the prior art where the re-entrant edge is arranged on a plane, and thus can achieve hierarchical removal of burrs, and can also better reduce the wear effect of burrs on the drill bit and improve the cutting effect.

[0010] The present invention is further configured such that the number of the first re-entrant edges is set to two, and the two first re-entrant edges are symmetrically distributed on the drill tip. Since the two first re-entrant edges are symmetrically distributed on the drill tip, it ensures the stability of the radial force during the cutting process of the drill bit.

[0011] The present invention is further configured such that the number of the second re-entrant edges is set to two, and the two second re-entrant edges are symmetrically distributed on the drill tip. Since the two second re-entrant edges are symmetrically distributed on the drill tip, it ensures the stability of the radial force during the cutting process of the drill bit.

[0012] The present invention is further configured such that the first back-hooking edge and the second back-hooking edge can be arranged symmetrically and spaced apart along the axial direction of the drill tip, so that the first back-hooking edge and the second back-hooking edge are in symmetrical positions, enabling uniform step-by-step cutting during cutting, improving the cutting efficiency, and the number of the first back-hooking edge and the second back-hooking edge can also be set to more than one.

[0013] The present invention is further configured such that the first back-hooking edge includes a first reverse edge and a first scraping edge arranged in sequence. Through the cutting action of the first reverse edge and the first scraping edge, it is convenient to remove burrs on fiber-reinforced composite materials such as CFRP materials.

[0014] The present invention is further configured such that the second back-hooking edge includes a second reverse edge and a second scraping edge arranged in sequence. Through the cutting action of the second reverse edge and the second scraping edge, it is convenient to remove burrs on fiber-reinforced composite materials such as CFRP materials.

[0015] The present invention is further configured such that a main cutting edge is provided on the drill tip, and a secondary cutting edge for cutting cooperation with the main cutting edge is provided on the cutting part. Both the main cutting edge and the secondary cutting edge play a cutting role, facilitating the cutting of fiber-reinforced composite materials such as CFRP materials, and thus realizing manual hole making.

[0016] The present invention is further configured such that a chip flute is provided on the drill tip. Through the chip flute, chip removal is achieved, quickly discharging the material cut by the drill bit, facilitating the drilling of fiber-reinforced composite materials such as CFRP materials.

[0017] The present invention is further configured such that the cutting part is arranged in a spiral shape. The cutting part plays a cutting role, and the spiral cutting part facilitates the drill bit to quickly cut fiber-reinforced composite materials such as CFRP materials, and thus realizes manual hole making.

[0018] The present invention has the following beneficial effects: Through the cutting action of the drill tip and the cutting part, drilling is performed on the laminated material. Since the first re-entrant edge and the second re-entrant edge are arranged at intervals along the axial direction of the drill tip and are distributed in a staggered manner up and down in the circumferential direction of the drill tip, through the cutting action of the first re-entrant edge and the second re-entrant edge, fiber-reinforced composite materials such as CFRP materials can be cut. Since the first re-entrant edge and the second re-entrant edge are arranged at intervals along the axial direction of the drill tip and are distributed in a staggered manner up and down in the circumferential direction of the drill tip, cutting can be performed at different positions respectively, which is different from the prior art where the re-entrant edge is arranged on a single plane. Thus, hierarchical removal of burrs can be achieved, and the wear of the burrs on the drill bit can be better reduced, improving the cutting effect. Furthermore, a fiber-reinforced composite material drill bit is provided, which improves the processing quality of the composite material, while ensuring the cutting ability of the drill tip and the stability of the processing process, eliminating the phenomena of drill jamming during drilling and forward punching when drilling holes, and improving the hole-making quality of the metal material in the laminated material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 is a three-dimensional structural schematic diagram of a fiber-reinforced composite material drill bit disclosed in this embodiment;

[0021] Figure 2 is a top view of a fiber-reinforced composite material drill bit disclosed in this embodiment;

[0022] Figure 3 is a parameter schematic diagram of the re-entrant edge in a fiber-reinforced composite material drill bit disclosed in this embodiment;

[0023] Figure 4 is a schematic diagram of hierarchical removal of a fiber-reinforced composite material drill bit disclosed in this embodiment.

[0024] Reference numerals: 1, shank; 2, cutting part; 21, secondary cutting edge; 3, drill tip; 31, first re-entrant edge; 311, first reverse edge; 312, first scraping edge; 32, second re-entrant edge; 321, second reverse edge; 322, second scraping edge; 33, main cutting edge. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can also be the communication inside two components. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0027] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0028] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] An embodiment of the present invention discloses a fiber-reinforced composite material drill bit, as Figures 1-4 shown, including: a shank 1, a cutting portion 2, and a drill tip 3 arranged in sequence. The drill tip 3 is successively provided with a first re-entrant edge 31 and a second re-entrant edge 32. The first re-entrant edge 31 and the second re-entrant edge 32 are arranged at intervals along the axial direction of the drill tip 3 and are distributed in a vertically staggered manner in the circumferential direction of the drill tip 3.

[0030] It should be noted that through the cutting action of the drill tip 3 and the cutting part 2, the laminated material is drilled. Since the first re-entrant edge 31 and the second re-entrant edge 32 are arranged at intervals along the axial direction of the drill tip 3 and are distributed in a staggered manner up and down in the circumferential direction of the drill tip 3, a fiber-reinforced composite material drill bit is provided. Through the cutting action of the first re-entrant edge and the second re-entrant edge, fiber-reinforced composite materials such as CFRP materials can be cut. Since the first re-entrant edge and the second re-entrant edge are arranged at intervals along the axial direction of the drill tip and are distributed in a staggered manner up and down in the circumferential direction of the drill tip, they can cut at different positions respectively, which is different from the prior art where the re-entrant edge is arranged on a plane. Thus, the hierarchical removal of burrs can be realized, and the wear of the burrs on the drill bit can be better reduced, improving the cutting effect. At the same time, the cutting ability of the drill tip and the stability of the machining process are ensured, the phenomenon of drill jamming during drilling and the phenomenon of forward impact when drilling out the hole are eliminated, and the hole-making quality of the metal material in the laminated material is improved.

[0031] As Figure 1 and Figure 2 shown, the number of the first re-entrant edges 31 is set to two, and the two first re-entrant edges 31 are symmetrically distributed on the drill tip 3. Since the two first re-entrant edges 31 are symmetrically distributed on the drill tip, the stability of the radial force during the cutting process of the drill bit is ensured.

[0032] As Figure 1 and Figure 2 shown, the number of the second re-entrant edges 32 is set to two, and the two second re-entrant edges 32 are symmetrically distributed on the drill tip 3. Since the two second re-entrant edges 32 are symmetrically distributed on the drill tip, the stability of the radial force during the cutting process of the drill bit is ensured.

[0033] As Figure 1 and Figure 2 shown, the first re-entrant edge 31 includes a first reverse edge 311 and a first scraping edge 312 arranged in sequence. Through the cutting action of the first reverse edge 311 and the first scraping edge 312, it is convenient to remove the burrs of fiber-reinforced composite materials such as CFRP materials.

[0034] As Figure 1 and Figure 2 shown, the second re-entrant edge 32 includes a second reverse edge 321 and a second scraping edge 322 arranged in sequence. Through the cutting action of the second reverse edge 321 and the second scraping edge 322, it is convenient to remove the burrs of fiber-reinforced composite materials such as CFRP materials.

[0035] As Figure 1 and Figure 2As shown, the drill tip 3 is provided with a main cutting edge 33, and the cutting part 2 is provided with a secondary cutting edge 21 that cooperates with the main cutting edge 33 for cutting. In the specific implementation process, the working section of the secondary cutting edge 21 is a reverse taper structure. The secondary cutting edge 21 is used to achieve reaming and chip removal functions, improving the machining quality of the hole wall while ensuring the machining accuracy of the hole diameter. Both the main cutting edge 33 and the secondary cutting edge 21 play a cutting role, facilitating the cutting of fiber-reinforced composite materials such as CFRP materials, and thus realizing manual hole making.

[0036] As Figure 1 and Figure 2 shown, the drill tip 3 is provided with a chip groove. The chip groove serves to discharge chips, quickly discharging the materials cut by the drill bit, facilitating the drilling of fiber-reinforced composite materials such as CFRP materials.

[0037] As Figure 1 and Figure 2 shown, the cutting part 2 is arranged in a spiral shape. The cutting part 2 plays a cutting role, and the spiral arrangement of the cutting part 2 facilitates the drill bit to quickly cut fiber-reinforced composite materials such as CFRP materials, and thus realizes manual hole making.

[0038] In the specific implementation process, as Figure 3 shown, the back-hook edge is composed of a reverse edge and a scraping edge, including the reverse edge angle α h1 , the scraping edge angle α h2 , the overall size l of the back-hook edge h1 , the length l of the reverse edge h2 . The structural parameters of each level of the back-hook edge are as Figure 3 shown. The size of the first back-hook edge 31 can be appropriately reduced in proportion according to the size of the second back-hook edge 32 to achieve the function of removing burrs of different scales.

[0039] As Figure 4 shown, for fiber-reinforced composite materials such as CFRP materials, the design of two-level back-hook edges can achieve hierarchical removal of burrs. For laminated materials such as CFRP laminated with CFRP materials, CFRP laminated with aluminum alloy, etc., due to certain differences in physical properties such as hardness and elastic modulus of the materials, during the drilling process, when the back-hook edge passes through the material junction, the length of the cutting edge participating in cutting changes, resulting in a change in the force on the drill bit. The original single-level back-hook edge design is prone to causing drill jamming during the drilling process and is likely to cause downward punching at the end of drilling, resulting in quality defects such as aluminum alloy outlet flanging and internal scratching of the hole wall. The symmetric staggered design improves the stability of the machining of the transition section at the material junction while ensuring the burr removal effect of the back-hook edge, and improves the operation experience of manual drilling.

[0040] Working principle: Through the cutting action of the drill tip 3 and the cutting part 2, drilling is performed on the laminated material. Since the first re-entrant edge 31 and the second re-entrant edge 32 are arranged at intervals along the axial direction of the drill tip 3 and are distributed in a staggered manner in the circumferential direction of the drill tip 3, a fiber-reinforced composite material drill bit is provided, which can achieve the hierarchical removal of burrs, while ensuring the cutting ability of the drill tip and the stability of the machining process, eliminating the phenomenon of drill jamming during drilling and the forward impact phenomenon when drilling out holes, and improving the hole-forming quality of the metal material in the laminated material.

[0041] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A fiber-reinforced composite material drill bit, characterized in that, Comprising: A shank portion (1), a cutting portion (2) and a drill tip (3) arranged in sequence, wherein a first back-hooking edge (31) and a second back-hooking edge (32) are successively provided on the drill tip (3), and the first back-hooking edge (31) and the second back-hooking edge (32) are arranged at intervals along the axial direction of the drill tip (3) and are distributed in a vertically staggered manner in the circumferential direction of the drill tip (3); The first back-hooking edge (31) comprises a first reverse edge (311) and a first scraping edge (312) arranged in sequence; the second back-hooking edge (32) comprises a second reverse edge (321) and a second scraping edge (322) arranged in sequence; a chip flute is provided on the drill tip (3); The first reverse edge (311) and the first scraping edge (312) are connected and arranged in a concave shape, and the second reverse edge (321) and the second scraping edge (322) are connected and arranged in a concave shape.

2. The fiber-reinforced composite material drill bit according to claim 1, wherein The number of the first back-hooking edges (31) is set to two, and the two first back-hooking edges (31) are symmetrically distributed on the drill tip (3).

3. The fiber-reinforced composite material drill bit according to claim 1 or 2, characterized in that The number of the second back-hooking edges (32) is set to two, and the two second back-hooking edges (32) are symmetrically distributed on the drill tip (3).

4. The fiber-reinforced composite material drill bit according to claim 1, wherein, The first back-hooking edge (31) and the second back-hooking edge (32) are symmetrically arranged at intervals along the axial direction of the drill tip (3).

5. The fiber-reinforced composite material drill bit according to claim 1, wherein A main cutting edge (33) is provided on the drill tip (3), and a secondary cutting edge (21) for cutting cooperation with the main cutting edge (33) is provided on the cutting portion (2).

6. The fiber-reinforced composite drill bit according to claim 1 or 5, characterized in that, The cutting portion (2) is arranged in a spiral shape.

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