Cutter

Abstract

The utility model relates to the technical field of mechanical manufacturing, and discloses a cutter which comprises a handle part and a blade part, a main cutting edge of the blade part comprises at least two sections of cutting edges with different relief angles, the cutting edges are sequentially arranged from inside to outside, and the vertex angle of the cutting edge on the inner side is larger than the vertex angle of the cutting edge on the outer side, so that in the drilling process, under the same feed amount, the cutting edge on the inner side is not prone to falling off. The intervention length of the main cutting edge is larger than the intervention length of the cutting edge of a conventional cutter, so that the actual cutting amount in unit length is smaller, the cutting is more stable, and the damage of an inlet and an outlet can be reduced. And moreover, the cutting amount is small, so that the axial cutting force is smaller, and the cutting resistance is smaller. According to the technical scheme, the change amount of the value of the front angle formed by grinding the front cutter face is reduced, the vibration resistance can be improved in the drilling process, drilling is smoother and more labor-saving, and therefore cutting dynamic optimization of the main cutting edge is achieved, stability is improved, the defects of burrs, layering, tearing and the like can be effectively restrained, and the drilling quality is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical manufacturing, in particular to a cutting tool. Background Art

[0002] Composite materials laminated with metal materials are widely used in the aerospace field. They can overcome the performance defects of single materials and improve strength. Usually, hole making is the main processing method, and they are assembled through bolt connections and other methods to form aviation equipment components. Composite fibers are strong and hard, but the interlayer bonding force is low. During hole making, delamination, burrs and tears are prone to occur at the entrance and exit, and burrs and flanging are prone to occur at the metal material outlet. Traditional metal cutting tools are difficult to meet the hole making quality requirements. In addition, due to the large size and complex spatial shape of parts, manual hole making is currently the most important processing method, especially at the assembly site, where a single part has a large number of holes and a long processing time. When conventional tools are used to cut the laminated structure of composite materials laminated with metal materials, there are sudden changes in cutting force during the cutting process, and it is easy to cause tearing and vibration at the entrance. There are also problems such as tool vibration and jamming, which lead to poor hole making stability, laborious hole making, and difficulty in ensuring the dimensional accuracy and roundness of the overall hole. It also increases the workload and fatigue of the operator. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems in the prior art. To this end, the present invention provides a tool capable of improving cutting stability.

[0004] According to the tool of the embodiment of the present invention, the shank is used for installing and fixing the tool; the blade has a tip at one end along the axial direction, and the end away from the tip is connected to the shank, the tip includes a main cutting edge, and the main cutting edge includes at least two cutting edges with different back angles, the cutting edges are arranged in sequence from the inside to the outside, the inner cutting edge is closer to the axis of the blade than the outer cutting edge, the top angle of the inner cutting edge is greater than the top angle of the cutting edge relatively located on the outside, and the angle value change of the front angle of the front cutting surface of the main cutting edge gradually decreases from the inside to the outside.

[0005] The tool of the embodiment of the present invention has at least the following beneficial effects: on the main cutting edge of the tool of the embodiment of the present invention, the top angle of the inner cutting edge is greater than the top angle of the cutting edge located relatively on the outer side. Therefore, during the drilling process, at the same feed rate, the main cutting edge intervention length is greater than the cutting edge intervention length of a conventional tool. Therefore, the actual cutting amount per unit length is smaller, making the cutting more stable, which is beneficial to reducing entry and exit damage. In addition, the small cutting amount makes the axial cutting force smaller, and thus the cutting resistance is smaller. The numerical change of the front angle of the front cutting edge after grinding is reduced, and the vibration resistance can be improved during the drilling process, and the hole making is smoother and more labor-saving, thereby achieving dynamic optimization of the main cutting edge cutting and improving stability. Therefore, when the tool is used for drilling CFRP / Al (carbon fiber composite material / aluminum alloy) laminated materials, it is easier to drill and control, thereby effectively reducing operator fatigue, and also helps to suppress defects such as burrs, delamination and tearing, and improve the quality of hole making.

[0006] According to the tool of an embodiment of the present invention, the at least two cutting edges with different back angles include a first cutting edge and a second cutting edge, the first cutting edge is closer to the axis than the second cutting edge, the outer diameter of the blade is D, and the maximum diameter range of the first cutting edge is 0.4D to 0.8D.

[0007] According to the tool of the embodiment of the present invention, the maximum diameter of the first section of the cutting edge is 0.6D.

[0008] According to the tool of an embodiment of the present invention, the blade portion includes two main cutting edges, the first cutting edge section of the two main cutting edges presents a first vertex angle, and the second cutting edge section of the two main cutting edges presents a second vertex angle, wherein: the angle range of the first vertex angle is 100° to 120°; and / or the angle range of the second vertex angle is 70° to 100°.

[0009] According to the cutting tool of the embodiment of the present invention, the angle of the first vertex angle is 110°, and / or the angle of the second vertex angle is 80°.

[0010] According to the tool of the embodiment of the present invention, the cutting edge has an axial rake angle of a set angle and a radial rake angle of a positive angle.

[0011] According to the tool of the embodiment of the present invention, the angle range of the axial rake angle is -7° to 7°, and / or the angle range of the radial rake angle is 3° to 15°.

[0012] According to the tool of the embodiment of the present invention, the cutting edge comprises at least three cutting edges spirally extending from the tip toward the shank, and the cutting edges are spaced apart from each other.

[0013] According to the cutting tool of the embodiment of the present invention, the cutting edge comprises the cutting edge and the blade back which spirally extend from the tip toward the shank, and at least one blade back has a cutting edge on both sides.

[0014] According to the tool of an embodiment of the present invention, the tip includes a chisel edge and two main cutting edges, the two main cutting edges are symmetrically arranged relative to the axis of the blade portion, the two main cutting edges are spaced apart from each other, the chisel edge is located between the two main cutting edges, and the spacing between the two main cutting edges is less than the length of the chisel edge.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram comparing the changing trends of the main cutting edge rake angles of the tool according to the embodiment of the utility model and the conventional tool;

[0017] Figure 2 Schematic diagram of several positions on the main cutting edge of a conventional tool;

[0018] Figure 3 for Figure 2 Schematic diagram of the rake angle at several positions on the middle main cutting edge;

[0019] Figure 4 A schematic diagram of the main cutting edge of a tool according to an embodiment of the present application;

[0020] Figure 5 Schematic diagram of several positions on the main cutting edge of the tool according to the embodiment of the utility model;

[0021] Figure 6 for Figure 5 Schematic diagram of the rake angle at several positions on the middle main cutting edge;

[0022] Figure 7 Schematic diagram comparing the cutting amount of the tool of the embodiment of the utility model and a conventional drill bit;

[0023] Figure 8 This is a schematic diagram of the cutting force during tool hole making;

[0024] Figure 9 Schematic diagram of a conventional tool and its axial rake angle;

[0025] Figure 10 Schematic diagram of machining carbon fiber composite materials using conventional tools;

[0026] Figure 11 Schematic diagram of machining aluminum alloy using conventional cutting tools;

[0027] Figure 12 Schematic diagram of a tool and its axial rake angle according to an embodiment of the present application;

[0028] Figure 13 A schematic diagram of processing a carbon fiber composite material using a cutting tool according to an embodiment of the present invention;

[0029] Figure 14 A schematic diagram of machining aluminum alloy using a cutting tool according to an embodiment of the present invention;

[0030] Figure 15 Schematic diagram of the support state of the cutting edge and hole wall of the tool according to the embodiment of the present utility model;

[0031] Figure 16 This is a schematic diagram of the tip of the embodiment of the present invention viewed along the axial direction;

[0032] Figure 17 Schematic diagram of the tearing condition at the hole entrance;

[0033] Figure 18 This is a schematic diagram of the flanging condition of the hole outlet;

[0034] Figure 19 This is the hole morphology comparison record diagram of test one;

[0035] Figure 20 This is a comparison record of the hole morphology of test 2.

[0036] Reference numerals:

[0037] Blade 200, tip 210, main cutting edge 211, first cutting edge 211a, second cutting edge 211b, chisel edge 212, non-cutting area 213, turning circle 214, blade back 220, margin 230;

[0038] hole wall 300;

[0039] Carbon fiber composite material 400, carbon fiber cutting layer 401;

[0040] Aluminum alloy 500, aluminum chips 501. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with the embodiments to fully understand the purpose, features, and effects of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without inventive effort are also within the scope of protection of the present invention.

[0042] In the description of the embodiments of the present invention, if orientation descriptions are involved, the orientations or positional relationships indicated by "up", "down", "front", "back", "left", "right", etc. are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0043] In the description of the embodiments of the present utility model, if a certain feature is referred to as being "set", "fixed", "connected", or "installed" on another feature, it may be directly set, fixed, or connected on the other feature, or it may be indirectly set, fixed, connected, or installed on the other feature. In the description of the embodiments of the present utility model, if "several" is involved, it means more than one; if "multiple" is involved, it means more than two; if "greater than", "less than", or "exceeds" is involved, it should be understood as not including the number itself; if "above", "below", or "within" is involved, it should be understood as including the number itself. If "first" or "second" is involved, it should be understood as being used to distinguish technical features, and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0044] Composite laminated metal materials are widely used in the aerospace field. For example, CFRP (carbon fiber reinforced resin-based composite materials) / Al (aluminum) laminated structures can overcome the performance defects of single materials and improve strength. Usually, hole making is the main processing method, and they are assembled through bolt connections and other methods to form aviation equipment components. Therefore, the hole making quality requirements are very stringent. However, the hole making processing of the laminated structure of composite laminated metal materials has problems such as delamination, tearing, and burrs at the inlet and outlet. Composite laminated metal materials are used in the aerospace field. Due to the large size and complex spatial shape of the parts, manual hole making is currently the main processing method, especially at the assembly site, where a single part has a large number of holes and a long processing time. Reference Figures 1 to 3 The trend of the conventional tool rake angle change is that the closer to the outer circle, the larger it is, and the closer to the center, the smaller it is. For example, the rake angles of positions B, C, D, and E on the main cutting edge from the center position A to the outer circle are 5°, 4°, 14°, and 23°, respectively. The angle value between positions C and D changes greatly, and the outermost rake angle value of the main cutting edge is close to the helix angle. During the drill cutting process, there is a sudden change in cutting force, which is easy to cause entrance tearing and vibration. There are problems such as tool vibration and jamming, which lead to poor hole making stability, laborious hole making, and difficulty in ensuring the dimensional accuracy and roundness of the overall hole. Tool vibration, poor stability and controllability greatly affect the processing efficiency and increase the operator's work intensity and fatigue.

[0045] This utility model optimizes the geometry of the main cutting edge through improvements to the tool structure. The main cutting edge is provided with at least two sections of cutting edges with different back angles and a top angle that increases from the inside outward, which can reduce cutting resistance and thus improve cutting stability. The rake face is ground to optimize the rake angle value, which can improve vibration resistance, making drilling easier and easier to control during operation, and helping to improve hole production quality. The following describes an embodiment of the utility model in conjunction with the accompanying drawings in the specification:

[0046] refer to Figure 1 and Figures 4 to 6 The cutting tool of the present invention comprises a shank and a blade 200. The shank is used for mounting and securing the cutting tool. The blade 200 has a tip 210 at one axial end, and the end facing away from the tip 210 is connected to the shank. The tip 210 of the blade 200 includes a primary cutting edge 211. The primary cutting edge 211 comprises at least two cutting edges with different clearance angles. The cutting edges are arranged sequentially from the inside outward, with the inner cutting edge closer to the axis of the blade 200 than the outer cutting edge.

[0047] Among them, reference Figure 4 The top angle of the inner cutting edge is greater than the top angle of the outer cutting edge. Therefore, during the drilling process, at the same feed rate, the main cutting edge 211 has a longer intervention length than the cutting edge of a conventional tool. As a result, the actual cutting amount per unit length is smaller, making the cutting more stable. The smaller cutting amount results in smaller axial cutting force, thereby reducing cutting resistance and making drilling and control easier during operation. Figure 1 The angle value change of the rake angle of the main cutting edge 211 ground on the front cutting surface gradually decreases from the inside to the outside. Compared with conventional tools, the rake angle value changes more gently, which can effectively solve the problem of sudden change in cutting force. The cutting dynamics are more stable, which can effectively suppress vibration and improve cutting stability. Therefore, the hole making process is smoother and more labor-saving, and it can help reduce the operator's fatigue when used in manual hole making.

[0048] The number of cutting edges with different back angles on the main cutting edge 211 can be greater than two, for example, three, four or more. Figure 4In some embodiments of the tool, at least two cutting edges with different clearance angles on the main cutting edge 211 include a first cutting edge 211a and a second cutting edge 211b, with the first cutting edge 211a being closer to the axis than the second cutting edge 211b. The outer diameter of the blade portion 200 is D, and the maximum diameter of the first cutting edge 211a can range from 0.4D to 0.8D. Thus, within this ratio range, when used to process laminated structures of composite materials and metal materials, the first cutting edge 211a and the second cutting edge 211b have appropriate sharpness and intervention length relative to the workpiece, while balancing sharpness and stability, achieving good operability and smoothness, and helping to reduce entry and exit defects. Specifically, the maximum diameter of the first cutting edge 211a can be 0.4D, 0.5D, 0.6D, 0.7D, 0.8D, or other values within the range of 0.4D to 0.8D.

[0049] refer to Figure 4 In some embodiments of the tool, the blade portion includes two main cutting edges 211, the first cutting edges 211a of the two main cutting edges 211 have a first vertex angle θ1, and the second cutting edges 211b of the two main cutting edges 211 have a second vertex angle θ2, wherein: the angle range of the first vertex angle θ1 can be 100° to 120°, for example, the angle of the first vertex angle θ1 can be 100°, 101°, 102°, 103°, 104°, 105°, 106°, 107°, 108°, 109°, 110°, 111°, 112°, 113°, 114°, 115°, 116°, 117°, 118°, 119°, 120° or other values within the range of 100° to 120°. The second vertex angle θ2 may range from 70° to 100°. For example, the second vertex angle θ2 may be 70°, 71°, 72°, 73°, 74°, 75°, 76°, 77°, 78°, 79°, 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95°, 96°, 97°, 98°, 99°, 100°, or other values within the range of 70° to 100°. For example, in a specific implementation, the first vertex angle θ1 may be 110°, and the second vertex angle θ2 may be 80°.

[0050] refer to Figure 7 and Figure 8 The tool 1 of the embodiment of the present invention is compared with a conventional drill bit 2, and is used to process a workpiece of composite material and metal material with a bottom hole 3. The cutting amount and cutting force of the tool are introduced through comparison.

[0051] refer to Figure 7Analysis of the cutting volume of each tool: At the same feed rate (constant Fr), the actual cutting volume (aq) and the cutting edge's cutting length (l) are affected by the cutting edge's vertex angle (θ). The relationship is expressed as: actual cutting depth aq = fr * sin (θ / 2), and intervention length l = fr * cos (θ / 2). Tool 1's cutting depth aq1 is smaller than the conventional drill's cutting depth aq2, with a ratio of approximately aq1:aq2 = 0.7:1. Tool 1's intervention length l1 is larger than the conventional drill's intervention length l2, with a ratio of approximately l1:l2 = 1.3:1. Therefore, Tool 1's main cutting edge 211 has a longer intervention length l1 than the conventional drill's intervention length l2, resulting in a smaller actual cutting volume per unit length and more stable cutting.

[0052] refer to Figure 7 and Figure 8 Analyzing the cutting forces of each tool, the actual cutting amount per unit length is directly proportional to the axial force (Fz). From the above analysis, it can be seen that the actual cutting amount per unit length of the main cutting edge 211 of tool 1 is smaller than that of conventional drill bits. Therefore, the axial force (Fz) of tool 1 is smaller than that of conventional drill bit 2. The radial force (Fk) is affected by the cutting edge top angle (θ), and the relationship expression is Fk = F*cos(θ / 2). Therefore, the radial force (Fk) of tool 1 is greater than that of conventional drill bits. The smaller the axial force (Fz), the smaller the cutting resistance, and the greater the radial force (Fk), the stronger the radial constraint effect on the drill bit. In summary, tool 1 is easier to drill and control during drilling, and the vibration is small.

[0053] Figure 5 Schematic diagram of several positions on the main cutting edge of the tool according to the embodiment of the utility model. Figure 6 Schematic diagram of the rake angle at several positions on the main cutting edge, refer to Figure 5 and Figure 6 In some embodiments of the tool, the rake face of the main cutting edge 211 is ground, and the rake angle of the main cutting edge 211 is ground to meet the following requirements: the numerical change of the rake angle gradually decreases from the axis of the blade portion 200 to the direction of increasing radial distance. This can effectively solve the problem of sudden changes in cutting force, and the cutting dynamics are more stable, which can effectively suppress vibration and improve cutting stability. Therefore, the hole making process is smoother and more labor-saving, which can help reduce operator fatigue when used in manual hole making. On this basis, combined with the aforementioned optimization of the axial rake angle and radial rake angle of the main cutting edge 211, the chip breaking performance is improved, while the cutting edge drilling peeling is weakened, which can effectively reduce burrs, delamination, splitting and other damages during hole making. The hole making process has good entrance quality and little damage, and the metal exit is free of flanging burrs, which is conducive to ensuring the accuracy and roundness of the hole diameter.

[0054] In some embodiments of the cutting tool, the radius of the blade 200 is R, and the rake angle of the main cutting edge 211 is ground to meet the following requirements: the rake angle varies from 0.4R to 0.9R from the axis of the blade 200, ranging from 0° to 4°. Compared to conventional cutting tools, this rake angle has a narrower range of variation and a smoother change, optimizing the cutting dynamics of the main cutting edge 211, improving the smoothness and stability of hole making, and providing good vibration resistance, which helps ensure dimensional accuracy and roundness. For manual hole making, reducing vibration can optimize operational feedback, thereby reducing effort, helping to reduce fatigue, and ensuring hole making efficiency and quality.

[0055] Specifically, as an example, reference positions A, B, C, D, and E can be taken on the main cutting edge 211 in the direction of increasing radial distance from the axis of the blade 200, where position A is the center of the tip 210 and corresponds to the position of the axis of the blade 200. Figure 5 、 Figure 6 The specific reference positions A, B, C, D, and E are selected according to the following table:

[0056] Position of the main cutting edge A B C D E The ratio of the radial distance from the blade axis to the blade radius 0 0.15 0.4 0.65 0.9

[0057] The values of the rake angles at the above reference positions are as follows: Figure 1 and Figure 6 As shown in FIG, the rake angle value at position B is 0°, the rake angle value at position C is 0.5°, the rake angle value at position D is 2.8°, and the rake angle value at position E is 4°. It can be seen that the rake angle value of the main cutting edge 211 has a gentle change trend, especially between reference positions C and E (i.e., from 0.4R to 0.9R from the axis of the cutting edge 200). The rake angle value change of the main cutting edge 211 in this section is between 0° and 4°, which is much smaller than the rake angle change between the corresponding positions C and E of the conventional tool (e.g., Figures 1 to 3 , from 4° to 23°, a change of 19°). This example is compared with the trend of the change of the main cutting edge 211 rake angle of the conventional tool. Figure 1 As shown, Figure 1 The horizontal axis represents the position on the main cutting edge 211 in the direction of increasing radial distance from the axis of the blade portion 200, and the vertical axis represents the rake angle value of the main cutting edge 211. Using the aforementioned reference positions A, B, C, D, and E on the main cutting edge 211 as reference points, Curve I and Curve II are respectively formed to represent the rake angle value variation trend curve for the conventional tool's main cutting edge 211 and the rake angle value variation trend curve for the main cutting edge 211 of the present embodiment. Curves I and II clearly demonstrate that the rake angle value variation resulting from rake face grinding of the main cutting edge 211 of the present embodiment is more gradual than that of conventional tools, thereby improving vibration resistance, optimizing operational feedback, and helping to reduce operator fatigue.

[0058] It should be noted that among the composite materials laminated with metal materials, the CFRP carbon fiber composite material 400 is a multi-directional laminated material with anisotropy. Figures 9 to 11 , the axial rake angle of ordinary drill bits varies greatly, refer to Figure 9 The axial rake angle of the inner edge grinding position of the conventional tool is 5° (such as Figure 9 Position B in the figure), the axial rake angle of the outer edge position rake face grinding position is 25° (as Figure 9 Position A) in the figure is used for processing composite materials. The specific positions A and B can be referred to Figure 2 When cutting with conventional tools, refer to Figure 10 , the composite material carbon fiber cutting layer 401 is prone to serious damage such as delamination, burrs and tearing, and the cutting temperature is high. There are also some difficulties in cutting metal materials. For example, aluminum alloy 500 has low hardness and strength, good plasticity, and although it has high thermal conductivity and good heat dissipation, and good cutting processability, aluminum chips 501 are not easy to break. Figure 11 When conventional cutting tools are used, aluminum alloy 500 is not easy to break when cutting and is easy to stick; stainless steel has severe work hardening, large cutting force, high temperature, and the chips are not easy to break and are easy to stick, so there are difficulties in chip breaking and processing problems, which can easily cause burrs and flanging at the exit. Difficult chip breaking can also easily lead to tool wrapping, requiring the tool to be stopped for cleaning. The chips will also scratch the processed surface, causing damage to the hole wall and easy sticking.

[0059] Based on the above embodiments, the embodiment of the present invention can also optimize the axial rake angle and radial rake angle of the main cutting edge to weaken the cutting edge drilling peeling, enhance the chip breaking performance, and reduce the burrs, delamination, splitting and other damages during hole making. Figure 12 In some embodiments of the present invention, the cutting edge has a set axial rake angle and a positive radial rake angle. Compared to conventional drill bits with a large axial rake angle variation, the cutting edge 200 of the present invention can press down on the surface material during drilling, weakening the cutting edge's peeling during drilling, effectively reducing entry burrs, delamination, and tearing. The cutting process can enhance chip breaking performance, reduce tool wrapping, effectively prevent chips from scratching the machined surface, and ensure drilling quality. Therefore, the structural improvement of the tip 210 of the cutting edge 200 can effectively suppress defects such as burrs, delamination, and tearing when drilling holes in laminated structures, meet hole quality requirements, and help improve the connection stability and strength of laminated material structures.

[0060] For example, Figure 12 An optional example is shown, wherein the position B diagram illustrates an example in which the axial rake angle of the inner edge grinding position (close to the axis position) of the embodiment of the present application is 0°, and the position A diagram illustrates an example in which the axial rake angle of the outer edge position (front cutting edge grinding position) is 4°, wherein position A corresponds to the axis position and position B corresponds to the position close to the axis. Figure 13 This is a schematic diagram of using a cutting tool according to an embodiment of the present invention to process a carbon fiber composite material. Figure 14 This is a schematic diagram of using a cutting tool according to an embodiment of the present invention to process aluminum alloy. Figure 13 and Figure 14 When the tool of the embodiment of the present invention is used for drilling CFRP / Al laminated materials, the radial rake angle of the main cutting edge 211 has an effect on the carbon fiber cutting layer 401 of the carbon fiber composite material 400, which causes the carbon fiber cutting layer 401 to break by peeling, everting, bending, and fracture (such as Figure 10 as shown) into downward extrusion cutting fracture (as shown) Figure 13 As shown), there is no burr, delamination, splitting or other damage at the entrance of the carbon fiber composite material layer; Figure 14 When cutting aluminum alloy 500, it causes aluminum chips 501 to deform and break, with better chip breaking performance, effectively suppressing outlet burrs and outward turning, reducing scratches on the machined surface, and thus improving hole making quality.

[0061] In some embodiments of the tool, unlike the variable axial rake angle of an ordinary drill bit, the axial rake angle of the cutting edge 200 of the tool can be an angle value in the range of -7° to 7°, and the radial rake angle can range from 3° to 15°, thereby optimizing the axial rake angle and the radial rake angle. The axial rake angle and the radial rake angle within this angle range are more conducive to the hole making processing of the above-mentioned carbon fiber composite material laminated metal material. The corresponding axial rake angle and radial rake angle of the main cutting edge 211 can be reasonably configured according to factors such as the required hole diameter and depth to reduce import and export damage. For example, the axial rake angle of the main cutting edge 211 can be -7°, -6°, -5°, -4°, -3°, -2°, -1°, 0°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, or other angle values within the range of -7° to 7°, and the radial rake angle can be 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, or other angle values within the range of 3° to 15°. In a specific implementation, the axial rake angle of the main cutting edge 211 is preferably 0°, and the radial rake angle is preferably 9°. When hole making is performed at this angle, the laminated structure composite material has less peeling and strong chip breaking performance. The processed hole has better entrance and exit morphology, which is conducive to stable and reliable assembly of the structural parts.

[0062] Figure 15 This is a schematic diagram of the support state of the cutting edge and the hole wall of the tool according to the embodiment of the present invention, referring to Figure 15In some embodiments of the tool, the blade 200 includes at least three blades 230 spirally extending from the tip 210 to the shank 100. The blades 230 are spaced apart from each other, so that when drilling, during the drilling stage between the main cutting edge 211 drilling into the hole and before drilling out, each blade 230 can form a contact support for the hole wall 300, forming at least three support points. The multi-point support structure formed during the machining process can improve the cutting stability, which is beneficial to improving the hole diameter accuracy and hole roundness, as well as improving the stability during drilling, and helping to reduce the exit flange. Specifically, refer to Figure 12 and Figure 15 In some embodiments of the cutting tool, the blade 200 includes a land 230 and a blade back 220 that spirally extend from the tip 210 toward the shank 100. At least one blade back 220 may have a land 230 on each side, thereby forming a multi-land 230 structure. For example, the blade 200 may include two spaced-apart blade backs 220, one of which has a single land 230 and the other has two spaced-apart lands 230. This creates three spaced-apart lands 230, thereby providing three support points for the hole wall 300. This three-point support structure can enhance support and improve hole diameter accuracy and roundness.

[0063] On the basis of the above embodiments, combined with the multi-edge belt structure of this embodiment, it can help improve the smoothness and stability of hole making, thereby playing a positive effect on optimizing operation feedback and helping to reduce fatigue.

[0064] Figure 16 This is a schematic diagram of the tip of the present invention observed along the axial direction, referring to Figure 16 In some embodiments, the tip 210 of the blade portion 200 includes a chisel edge 212 and two main cutting edges 211. The two main cutting edges 211 are symmetrically arranged relative to the axis of the blade portion 200. The two main cutting edges 211 are spaced apart from each other, and the chisel edge 212 is located between the two main cutting edges 211. During drilling, the rotation of the chisel edge 212 can achieve effective centering, ensuring the smooth entry of the subsequent main cutting edge 211.

[0065] It is understood that the area between the chisel edge 212 and the two main cutting edges 211 has no cutting ability and can be referred to as a non-cutting zone 213. Generally speaking, the larger the non-cutting zone 213 on the tip 210, the greater the resistance during drilling, the weaker the sharpness, and the more laborious the drilling. The size of the non-cutting zone 213 can be reflected by the size of the tangent circle between the two main cutting edges. In a further embodiment of the present invention, the spacing between the two main cutting edges 211 on the tip 210 is less than the length of the chisel edge 212, that is, the diameter of the tangent circle between the two main cutting edges 211 is less than the diameter of the circle of revolution 214 of the chisel edge 212 (the diameter of the circle of revolution 214 of the chisel edge 212 is equal to the length of the chisel edge 212), and the tangent circle and the circle of revolution 214 are concentric. Thus, for a given length of the chisel edge 212, the non-cutting zone 213 between the two main cutting edges 211 and the chisel edge 212 is reduced, thereby reducing the drilling resistance and making drilling more labor-saving. Building on the above-mentioned embodiment, the distribution structure of the main cutting edge 211 and the chisel edge 212 in this embodiment improves drilling sharpness and centering capability, thereby facilitating improved hole placement accuracy. The reduced drilling resistance also helps improve hole-making fluidity and stability, thereby optimizing operational feedback and reducing fatigue.

[0066] It should be noted that, in addition to the above-mentioned vibration and laborious conditions, operational feedback during hole-making processing also affects the operation and hole-making quality, including jamming and forward thrust. Part of the jamming during operation is caused by chip breaking during the processing. The embodiment of the present invention optimizes the chip breaking performance and can improve the jamming situation; forward thrust mainly occurs in the drilling stage of the hole-making process. Poor cutting stability will cause the blade 200 to rush outward before cutting into place during the drilling stage, which will cause flanging at the outlet. The optimization of hole-making stability and chip breaking performance can improve the forward thrust situation.

[0067] The following is an example of a machining test of the tool of the embodiment of the utility model using a conventional twist drill as a comparative example:

[0068] Material of component to be processed: 3.8mm T700 CFRP laminated with 4mm 7050-T6 aluminum plate.

[0069] Commonly used processing equipment: 3000rpm pneumatic drill gun.

[0070] There are two common hole making methods: horizontal hole making with D2.55 bottom hole and horizontal hole making without bottom hole.

[0071] Common damage description: Common damage includes entrance tearing and exit flange; among them, refer to Figure 17 The entrance tear condition is characterized by the difference L between the hole radius R0 and the maximum hole tear radius R1, that is, L = R1-R0, in mm. Figure 18The outlet flange is characterized by the flange height H, the unit is mm.

[0072] Operational Feedback: Multiple operators manually drilled holes using the aforementioned equipment and rated the operational feedback on each drilling tool's cutting operation based on the following criteria: Chatter, Jam, and Throttle: 1-3 points, with higher values indicating severity. Effort: 1-5 points, with higher values indicating severity, with 1 indicating no effort and 5 indicating no hole being produced.

[0073] Test 1:

[0074] The hole making process was carried out on 3.8mm T700 CFRP laminated with 4mm aluminum plate 7050-T6. Under the condition of D2.55 bottom hole, the horizontal hole making test was carried out. The operation feedback was recorded in Table 1, the hole damage was recorded in Table 2, and the hole morphology was recorded in Table 3. Figure 19 shown.

[0075] Table 1: D2.55 bottom hole test record

[0076] Serial number Knives Shocking Sword laborious Stuck and stopped Charge 1 The utility model tool 2 1 2 1 2 Conventional twist drill 3 4 3 2

[0077] Table 2: D2.55 bottom hole test hole damage record

[0078] Serial number Knives Entrance tear L(mm) Outlet flange H(mm) Remark 1 The utility model tool 0.24 0.11 2 Conventional twist drill 3.2 0.19 Poor roundness

[0079] The results of Test 1 above show that when the tool of the embodiment of the present invention is used for the above processing test, compared with the conventional twist drill, as shown in Table 1 above, the vibration, effort, jamming and forward thrust during the operation are all reduced, and the operation feedback is optimized. As shown in Table 2 above, the tear L at the entrance of the hole formed by the processing is significantly reduced, and the flange H at the exit is also reduced, thereby optimizing the hole quality. Figure 19 ,in Figure 19 a and b are the entrance and exit morphologies of the hole obtained by the above-mentioned processing using the tool of the utility model, respectively. Figure 19 Figures c and d are the entrance and exit morphologies of the hole obtained by the above processing using a conventional twist drill. Figure 19 Compared with a and c in Figure 1, and combined with Table 2, it can be seen that the hole entrance tear L formed by the tool processing of the utility model is 0.37mm, and the hole entrance tear L formed by the tool processing of the utility model is 0.37mm. Figure 19 There is no obvious entrance tear in a, while the hole entrance tear L formed by conventional twist drill is 3.2mm. Figure 16 C in the figure has a clear entrance tear. Figure 19 Compared with b and d in the figure, and combined with the comparison in Table 2, it can be seen that the hole formed by the tool of the utility model has an outlet flange H of 0.12mm. Figure 19There is no obvious outlet flange in a, and the outlet flange formed by conventional twist drill is 0.19mm. Figure 19 The "d" in the letter has a distinct flanging.

[0080] Test 2:

[0081] The hole making process was carried out on 3.8mm T700 CFRP laminated with 4mm aluminum plate 7050-T6. In the absence of bottom hole, horizontal hole making test was carried out. The operation feedback was recorded in Table 3, the hole damage was recorded in Table 4, and the hole morphology was recorded in Table 5. Figure 20 shown.

[0082] Table 3: Bottomless hole test record

[0083] Serial number Knives Shocking Sword laborious Stuck and stopped Charge 1 The utility model tool 1 1 2 1 2 Conventional twist drill 1 4 3 2

[0084] Table 4: Damage record of bottomless hole test hole

[0085] Serial number Knives Entrance tear L(mm) Outlet flange H(mm) Remark 1 The utility model tool 0.44 0.12 2 Conventional twist drill 0.72 0.2 Export burrs

[0086] The results of the second test show that the tool of the embodiment of the present invention is used for the above processing test. Compared with the conventional twist drill, as shown in Table 3, the effort, jamming and forward thrust during the operation are reduced, and the operation feedback is optimized. As shown in Table 4, the hole entrance tear L is significantly reduced, and the exit flange H is also reduced, thereby optimizing the hole quality. Figure 20 ,in Figure 20 a and b are the entrance and exit morphologies of the hole obtained by the above-mentioned processing using the tool of the utility model, respectively. Figure 20 Figures c and d are the entrance and exit morphologies of the hole obtained by the above processing using a conventional twist drill. Figure 20 Compared with a and c in Figure 4, and combined with Table 4, it can be seen that the hole entrance tear L formed by the tool processing of the utility model is 0.13mm, and the hole entrance tear L formed by the tool processing of the utility model is 0.13mm. Figure 20 There is no obvious entrance tear in a, while the hole entrance tear L formed by conventional twist drill is 0.72mm. Figure 20 C in the figure has a clear entrance tear. Figure 20 Compared with b and d in the figure, and combined with Table 4, it can be seen that the hole formed by the tool of the utility model has an outlet flange H of 0.08mm. Figure 20 There is no obvious outlet flange in a, and the hole outlet flange H formed by conventional twist drill processing is 0.2mm. Figure 20 The d in the figure has obvious flange and exit burr.

[0087] The cutting tool of this embodiment, through the aforementioned structural improvements to the cutting edge 200, can enhance cutting stability and controllability when drilling holes in laminated structures, while suppressing defects such as burrs, delamination, tearing, and flanging, thereby improving hole quality. The cutting tool is suitable for drilling holes in laminated structures composed of carbon fiber composites and metals, and thus has broad application in the aerospace field.

[0088] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various modifications can be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. In addition, the embodiments of the present invention and the features of the embodiments can be combined with each other unless there is a conflict.

Claims

1. A cutting tool, characterized in that: include: The handle is used to install and fix the tool; The blade portion has a tip at one end along the axial direction, and the end away from the tip is connected to the shank portion, the tip includes a main cutting edge, and the main cutting edge includes at least two cutting edges with different back angles. The cutting edges are arranged in sequence from the inside to the outside, and the inner cutting edge is closer to the axis of the blade portion than the outer cutting edge. The top angle of the inner cutting edge is greater than the top angle of the cutting edge relatively located on the outside. The angle value of the front angle of the main cutting edge rake face ground from 0.4R to 0.9R from the axis of the blade portion varies between 0° and 4° and gradually decreases from the inside to the outside.

2. The tool according to claim 1, characterized in that The at least two cutting edges with different back angles include a first cutting edge and a second cutting edge. The first cutting edge is closer to the axis than the second cutting edge. The outer diameter of the blade is D, and the maximum diameter range of the first cutting edge is 0.4D to 0.8D.

3. The tool according to claim 2, characterized in that The maximum diameter of the first section cutting edge is 0.6D.

4. The tool according to claim 2, characterized in that The blade portion includes two main cutting edges, the first cutting edge segments of the two main cutting edges are at a first vertex angle, and the second cutting edges of the two main cutting edges are at a second vertex angle, wherein: The first vertex angle ranges from 100° to 120°; And / or, the second vertex angle ranges from 70° to 100°.

5. The tool according to claim 4, characterized in that The angle of the first vertex angle is 110°, and / or the angle of the second vertex angle is 80°.

6. The tool according to any one of claims 1 to 5, characterized in that The cutting edge has an axial rake angle of a set angle and a radial rake angle of a positive angle.

7. The tool according to claim 6, characterized in that The axial rake angle ranges from -7° to 7°, and / or the radial rake angle ranges from 3° to 15°.

8. The tool according to any one of claims 1 to 5, characterized in that The blade portion includes at least three lands spirally extending from the tip toward the shank, and the lands are spaced apart from each other.

9. The tool according to claim 8, characterized in that The blade portion includes a land and a blade back spirally extending from the tip toward the shank, and at least one blade back is provided with a land on each of its two sides.

10. The tool according to any one of claims 1 to 5, characterized in that The tip includes a chisel edge and two main cutting edges, the two main cutting edges are symmetrically arranged relative to the axis of the blade portion, the two main cutting edges are spaced apart from each other, the chisel edge is located between the two main cutting edges, and the spacing between the two main cutting edges is less than the length of the chisel edge.

Images