Spiral end mill for machining carbon fiber holes and its preparation method

Abstract

This invention provides a spiral end mill for machining carbon fiber holes and its manufacturing method. The spiral end mill has a reduced-diameter shank, with a top cutting edge, a reverse cutting edge, a forward progressive cutting edge, and a bottom cutting edge connected sequentially below the shank. The invention also provides a method for machining the spiral end mill for carbon fiber holes, including grinding the reduced-diameter shank, cycloidal two-step grinding of the spiral grooves of the bottom cutting edge and the forward progressive cutting edge, a three-step transverse and longitudinal cycloidal grinding process for machining the spiral grooves of the reverse cutting edge and the rake angle of the top cutting edge, a three-stage grinding process for machining the double clearance angle structure of the tool, and final fine grinding and fine adjustment. This method addresses the problems of severe tool wear, hole defects, poor versatility in hole enlargement, and difficulty in ensuring tool manufacturing precision during carbon fiber hole machining. It enables hole making, finishing, deep hole and hole enlargement machining to be completed in a single cut, and the tool grinding method ensures smooth grinding and good cutting performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of carbon fiber composite material hole machining, in particular to a spiral milling cutter for machining carbon fiber composite material hole and a preparation method thereof. BACKGROUND

[0002] Carbon fiber reinforced polymer (CFRP) is widely used in the field of aerospace due to its lightweight and high-quality equipment. However, due to the characteristics of CFRP, such as inhomogeneity, anisotropy, low interlaminar strength, and high hardness of carbon fiber, machining defects such as delamination, tearing, and burr are easily generated during hole machining, which makes it difficult to guarantee the machining quality and seriously affects the fatigue life and connection strength of CFRP load-bearing and connection structure. Although traditional drilling machining can effectively complete hole machining, burrs and tears are easily generated, resulting in poor surface quality of the hole, and the roundness needs to be polished and ground in the subsequent processing sequence, which greatly reduces the processing efficiency and product quality. The reason is that the applicability of the tool structure and the degree of wear and grinding often have a great impact. At the same time, the grinding quality of the cutting edge of the tool directly affects the performance of the tool and the quality of the hole, so it is imperative to develop a carbon fiber hole machining tool suitable for different working conditions, and the grinding technology of high-precision tools also needs to be solved. SUMMARY

[0003] The purpose of the present application is to provide a spiral milling cutter for machining carbon fiber composite material hole and a preparation method thereof, to solve the problems existing in the prior art, to realize one-time cutting for hole machining and finishing, to change the direction of chips, to reduce cutting heat, to reduce damage to the hole caused by thermal plastic deformation, to realize hole expansion machining, to realize deep hole machining, and to propose a grinding method for the tool to ensure smooth grinding of the tool and ensure the cutting performance of the tool.

[0004] To achieve the above purpose, the present application provides the following scheme:

[0005] A spiral milling cutter for machining carbon fiber hole, comprising a tool shank, the tool shank is a reduced diameter tool shank, the tool shank is connected in sequence from bottom to top with a top edge cutting part, a reverse cutting edge part, a positive progressive cutting edge part and a bottom cutting edge part; the top edge cutting part is concave arc-shaped; the reverse cutting edge part is convex arc-shaped and adopts a left-hand cutting edge structure; the positive progressive cutting edge part is conical or convex arc-shaped and adopts a right-hand cutting edge structure; the bottom cutting edge part is a straight edge or a circular arc edge.

[0006] The bottom cutting edge part and the positive progressive cutting edge part adopt arc tangent transition or straight line tangent transition and adopt smooth design processing. The top cutting edge part and the reverse cutting edge part adopt arc tangent transition or straight line tangent transition and adopt smooth design processing. The smooth design processing not only has smooth transition in structure design, but also ensures the smoothness of the transition area through the control of the grinding wheel swing angle during grinding processing. Thus, the tool can reduce the friction between the tool and the material and the chip can be more easily removed from the rake face of the tool.

[0007] Preferably, when the bottom cutting edge part adopts a straight edge structure and the positive progressive cutting edge part adopts a conical shape, both adopt smooth design processing.

[0008] Preferably, when the bottom cutting edge part adopts a circular arc edge structure and the positive progressive cutting edge part adopts a conical shape, both adopt smooth design processing.

[0009] Preferably, when the bottom cutting edge part adopts a straight edge structure and the positive progressive cutting edge part adopts a convex arc shape, both adopt smooth design processing.

[0010] Preferably, when the bottom cutting edge part adopts a circular arc edge structure and the positive progressive cutting edge part adopts a convex arc shape, both adopt smooth design processing.

[0011] Preferably, when the positive progressive cutting edge part adopts a conical shape, the angle α between the conical cutting edge and the axis is 15°-25°, which is used for deep hole machining. Through the shearing action of the sharp conical cutting edge on the material, the friction between the single position cutting edge and the material can be reduced, and the chip can be effectively guided to leave the rake face of the tool. At the same time, the diameter of the bottom cutting edge part connected thereto is smaller than that of the positive progressive cutting edge part, and when the bottom cutting edge part adopts a straight edge structure, the contact length of the cutting position can be effectively increased, the cutting volume can be increased, and the machining efficiency can be improved. Therefore, the bottom cutting edge can improve the cutting efficiency of the hole, the positive progressive cutting edge part can ensure the machining precision of removing material layer by layer and disperse the tool wear rate. As the tool axially feeds downward to machine the hole, the reverse cutting edge part participates in the hole machining, and the left-hand cutting edge can change the constraint and cutting direction of the fiber, effectively improving the surface quality and roundness of the hole.

[0012] Preferably, when the positive progressive cutting edge part adopts a conical shape, the angle α between the conical cutting edge and the axis is 25°-45°, which is used for progressive milling of holes. At the same time, the left-hand cutting edge of the reverse cutting edge part can change the constraint direction of the carbon fiber, effectively remove burrs, ensure the hole quality, and reduce the cycle machining time. Once the tool feeds, the fine machining is completed, and the cost is reduced.

[0013] Preferably, when the positive progressive cutting edge part adopts a conical shape, the angle a between the conical cutting edge and the axis is 45-60°, which is used for expanding hole processing, the hole depth is less than the height of the positive progressive cutting edge part, the processing mode of spiral hole milling is adopted, the conical positive progressive cutting edge is used for conical expanding hole processing, with the tool axially feeding downward, after the highest point of the positive progressive cutting edge part cuts through the whole hole depth, the hole diameter meets the requirement, the tool can be withdrawn to the center of the hole and withdrawn from the processing process along the axial direction upward, the processing efficiency is high and the versatility is strong.

[0014] Meanwhile, the application also provides a spiral milling cutter for processing carbon fiber hole parts and a preparation method thereof, comprising the following steps:

[0015] S1, grinding the reduced diameter tool handle, selecting a flat grinding wheel, keeping the wheel core coaxial with the tool bar stock, applying the outer cylindrical surface of the flat grinding wheel to the tool handle, so that the diameter of the tool handle is reduced to the design position, i.e. completing the grinding reduction;

[0016] S2, adopting the cycloid two-step grinding method to process the spiral groove of the bottom cutting edge part and the positive progressive cutting edge part, i.e. first adjusting the cycloid angle of the grinding wheel (equal to the rake angle of the bottom cutting edge part) to determine the processing contact line, calculating the grinding trajectory line according to the parameters of the grinding wheel, processing the spiral groove of the bottom cutting edge part, then adjusting the cycloid angle of the grinding wheel (equal to the rake angle of the positive progressive cutting edge part) to process the spiral groove of the positive progressive cutting edge part, after meeting the smooth design of the connecting position, withdrawing to the safe position along the radial direction;

[0017] S3, adopting the horizontal movement and vertical swing three-step method to process the spiral groove of the reverse cutting edge part and the rake angle of the top cutting edge part, i.e. first horizontally (radially) moving the flat grinding wheel, so that the cutting distance of the grinding wheel is 1 / 4r from the distance of the spiral groove of the positive progressive cutting edge part, r is the tool radius; vertically swinging the grinding wheel to grind the angle (equal to the rake angle of the reverse cutting edge part) to process the spiral groove of the reverse cutting edge part; finally, vertically swinging the grinding wheel to grind the angle (equal to the rake angle of the top cutting edge part) to meet the smooth design of the transition connecting position, process the top cutting edge part, and gradually reduce the cutting depth and exit along the reduced position;

[0018] S4, the double clearance structure of the tool is processed by adopting a three-stage grinding process method, the tool has a double clearance structure, has very high impact resistance and vibration resistance, and can improve the chip removal performance. Firstly, the V grinding wheel swing angle is adjusted to meet the requirements of the first clearance angle of the bottom cutting edge, the first clearance angle of the bottom cutting edge is processed using the side surface, and the posture is adjusted to meet the first clearance angle parameters of the forward progressive cutting edge, meet the smooth design processing of the transition connection position, and the first clearance angle of the forward progressive cutting edge is processed, which is the first stage of grinding; secondly, the grinding wheel is moved transversely to determine the cutting contact line of the first clearance angle of the reverse cutting edge, and the first clearance angle is processed to the smooth design area of the top cutting edge, which is the second stage of grinding; finally, the grinding wheel is withdrawn to the top of the reverse cutting edge, the posture of the grinding wheel is adjusted, the smooth design processing of the transition connection position is met, the grinding path passes through the above-mentioned smooth design area again, and the first clearance angle of the top cutting edge is ground, which is the third stage of grinding. After three stages of grinding, part of the grinding track overlaps, the grinding positioning accuracy is high, the tool can have good size accuracy, good machining accuracy and surface roughness can be obtained; according to the above method, the second clearance angle of the tool is also processed, the double clearance angle design ensures that the tool has sufficient edge strength while can be strong cutting with large feed;

[0019] S5, finally, fine grinding is performed, the V grinding wheel swing angle is adjusted according to the rake angle requirements of the bottom cutting edge, fine grinding is performed, and the spiral groove of the forward progressive cutting edge is sequentially extended to the safety exit; according to the design requirements of the cutting rake angle of the top cutting edge, the V grinding wheel posture is adjusted, the cutting edge rake angle is transitionally ground from the reduced diameter to the top cutting edge, and is sequentially extended to the spiral groove of the reverse cutting edge, and is withdrawn along the radial direction, which can effectively remove the tool marks that may exist during initial processing, and reduce the surface roughness of the tool;

[0020] S6, in the above processing steps, when the grinding wheel participates in grinding, the cutting fluid is turned on, the axial position and radial spacing of the cutting fluid, as well as the height and angle of the cutting fluid are adjusted, which is suitable for the position of the grinding wheel grinding, the cutting color of the tool bar is observed, the speed and flow of the cutting fluid are adjusted, the cutting speed and flow should be increased when the cutting is black, and the grinding feed speed should be reduced, the cutting is brown or blue, the speed and flow of the cutting fluid should be appropriately reduced or maintained; in the fine grinding step, the cutting fluid is turned off.

[0021] The present application has the following technical effects compared with the prior art:

[0022] The present application can be applied in deep hole machining, the bottom cutting edge can improve the cutting efficiency of the hole, the forward progressive cutting edge can ensure the machining accuracy of removing material layer by layer, reduce the friction between the single position cutting edge and the material, disperse the tool wear rate, efficiently guide the cutting chip to leave from the rake face of the blade, and the reverse cutting edge can change the constraint and cutting direction of the fiber, effectively improve the hole surface quality and roundness.

[0023] The application can realize progressive hole milling by using forward progressive cutting edges, realize fine machining by using reverse cutting edges, effectively remove burrs and other machining defects, ensure hole machining quality, reduce cycle machining time, complete fine machining by one feeding, and reduce cost.

[0024] The application can realize reaming machining, and is efficient and versatile.

[0025] The application solves the problem of smooth grinding of the rake angle of the left-hand reverse cutting edge part and the rake angle of the top cutting part.

[0026] The application processes the double-rake-angle structure of the tool by using a three-step grinding process, solves the technical difficulty of the smooth design of the rake angle from the bottom cutting edge part to the forward progressive cutting edge part, and solves the technical bottleneck of the smooth design of the grinding process of the reverse cutting edge part to the top cutting part, so that the machining precision is high and the edge strength is sufficient.

[0027] The application adopts fine grinding and fine adjustment grinding method, which can effectively remove the tool marks possibly existing in the primary machining, reduce the surface roughness of the tool, and stabilize the tool machining quality. DETAILED DESCRIPTION

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0029] Figure 1 It is a whole schematic view of the spiral milling cutter for machining carbon fiber hole parts of the application;

[0030] Figure 2 It is a structural schematic view of the spiral milling cutter for machining carbon fiber hole parts of the application when used for deep hole machining;

[0031] Figure 3 It is a structural schematic view of the spiral milling cutter for machining carbon fiber hole parts of the application when used for progressive hole milling;

[0032] Figure 4 It is a structural schematic view of the spiral milling cutter for machining carbon fiber hole parts of the application when used for reaming machining;

[0033] Figure 5 It is a cycloid two-step grinding method schematic view of the spiral milling cutter for machining carbon fiber hole parts of the application;

[0034] Figure 6This is a schematic diagram of the three-step grinding method of the spiral end mill for machining carbon fiber hole parts according to the present invention;

[0035] Figure 7 This is a schematic diagram of the three-stage grinding method for the spiral end mill used in the present invention to process carbon fiber hole parts;

[0036] Figure 8 This is a schematic diagram of the fine grinding method for the spiral end mill used in machining carbon fiber hole parts according to the present invention.

[0037] Wherein, 1 is the top cutting edge, 2 is the reverse cutting edge, 3 is the forward progressive cutting edge, 4 is the bottom cutting edge, r is half the diameter of the tool cutting edge, i.e., the radius; α is the angle between the generatrix of the forward progressive cutting edge 3 and the axis. Detailed Implementation

[0038] The purpose of this invention is to provide a spiral milling cutter for machining carbon fiber holes and its manufacturing method, thereby solving the problems existing in the prior art. This addresses the severe tool wear issue in deep hole machining of carbon fiber, altering fiber constraints and cutting direction to effectively improve hole surface quality and roundness. Simultaneously, it enables progressive milling and finishing, effectively removing burrs and other machining defects, ensuring hole quality, and reducing cycle time, completing finishing in a single feed. It also provides efficient and versatile hole reaming. Furthermore, this invention proposes a three-step transverse and longitudinal oscillation method and a three-stage grinding process, solving the problem of smoothing the cutting edge during grinding. It also introduces a fine-tuning grinding method to effectively remove tool marks that may exist in the initial machining, reduce tool surface roughness, and maintain stable machining quality.

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Implementation Case 1: For example Figure 2 As shown, when the forward progressive cutting edge 3 is conical, the angle α between the conical cutting edge and the axis is 15°-25°. It is used for deep hole machining. Through the shearing action of the sharp conical cutting edge on the material, the friction between the cutting edge and the material at a single position can be reduced, and the chips can be efficiently guided to leave from the rake face of the insert. At the same time, the bottom cutting edge 4 connected to it has a smaller diameter than the forward progressive cutting edge 3 and adopts a straight edge structure, which can effectively increase the contact length at the cutting position, increase the cutting volume, and improve the cutting efficiency. Therefore, the bottom cutting edge can improve the cutting efficiency of entering the hole, and the forward progressive cutting edge 3 can ensure the machining accuracy of removing material layer by layer and disperse the tool wear rate. As the tool feeds downward along the axial direction to machine the hole, the reverse cutting edge 2 participates in the hole machining. The left-hand cutting edge can change the constraint of the fibers and the cutting direction, effectively improving the surface quality and roundness of the hole.

[0041] Implementation Case 2: For example Figure 3 As shown, when the positive progressive cutting edge 3 is conical, the angle α between the conical cutting edge and the axis is 25°-45°, which is used for progressive milling. The conical positive progressive cutting edge 3 can make holes layer by layer. As the tool helically mills the hole and moves downward axially, a conical hole is formed until the maximum diameter of the positive progressive cutting edge 3 participates in the machining. The hole shape is gradually machined from conical to cylindrical straight hole. At the same time, the left-hand cutting edge of the reverse cutting edge 2 can change the constraint direction of the carbon fiber, improve the machining, effectively remove burrs, ensure the quality of hole making, and reduce the cycle machining time. The finishing machining is completed in one feed, reducing costs.

[0042] Implementation Case 3: For example Figure 4 As shown, when the positive progressive cutting edge 3 is conical, the angle α between the conical cutting edge and the axis is 45°-60°, which is suitable for hole reaming because the taper is large and the maximum diameter of the tool is large, resulting in a wide range of reamed shaft diameters. When the hole depth is less than the height of the positive progressive cutting edge 3, a spiral milling method is used. The conical positive progressive cutting edge is used for conical reaming. As the tool feeds downward along the axial direction, the highest point of the positive progressive cutting edge 3 cuts through the entire hole depth. Once the hole diameter meets the requirements, it can return to the center of the hole and exit the machining process upward along the axial direction. This process is efficient and versatile. When the hole depth is greater than the height of the positive progressive cutting edge 3, the reverse cutting edge 2 helps to complete the finishing process, ensuring the roundness and quality of the workpiece surface.

[0043] Implementation Case 4: For example Figure 5 As shown, this invention employs a cycloidal two-step grinding method to machine the helical grooves of the bottom cutting edge 4 and the forward progressive cutting edge 3. First, the cycloidal angle of the grinding wheel is adjusted (equal to the rake angle of the bottom cutting edge) to determine the machining contact line. Based on the parameters of the grinding wheel, the grinding trajectory line is calculated to machine the helical groove of the bottom cutting edge. Then, the cycloidal angle of the grinding wheel is adjusted (equal to the rake angle of the forward progressive cutting edge 3) to machine the helical groove of the forward progressive cutting edge 3. After satisfying the smoothing design at the connection point, the machine exits to a safe position in the radial direction.

[0044] Implementation Case 5: For example Figure 6 As shown, this invention employs a three-step method of horizontal movement and vertical swing to process the helical groove of the reverse cutting edge 2 and the rake angle of the top cutting edge 1. First, the flat grinding wheel is moved horizontally (radially) so that the cutting distance of the grinding wheel and the distance between the helical groove of the forward progressive cutting edge 3 are 1 / 4r, where r is the tool radius. Then, the grinding wheel is swung longitudinally at a grinding angle (equal to the rake angle of the reverse cutting edge 2) to process the helical groove of the reverse cutting edge 2. Finally, the grinding wheel is swung longitudinally at a grinding angle (equal to the rake angle of the top cutting edge 1) to meet the smoothing design of the transition connection position, and the top cutting edge 1 is processed. The cutting depth is gradually reduced and the cutting wheel exits along the reduced diameter.

[0045] Implementation Case Six: Figure 7 As shown, this invention employs a three-stage grinding process to machine the double back angle structure of the cutting tool. The overall tool design features a double back angle structure, exhibiting extremely high impact and vibration resistance while also improving chip removal performance. First, the V-wheel tilt angle is adjusted to meet the requirements of the first back angle of the bottom cutting edge 4. The first back angle of the bottom cutting edge 4 is machined using the side profile, and the posture is adjusted to meet the parameters of the first back angle of the forward progressive cutting edge 3, satisfying the smoothing design of the transition connection position. This constitutes the first stage of grinding. Second, the grinding wheel is moved laterally to determine the cutting contact line of the first back angle of the reverse cutting edge 2, machining it to the smoothing design area with the top cutting edge 1, which constitutes the second stage of grinding. Finally, the grinding wheel is withdrawn to the reverse cutting edge 2. At the top, adjust the grinding wheel posture to meet the smoothing design of the transition connection position. After the grinding path passes through the smoothing design area again, grind to the first rear angle of the top cutting edge 1, which is a 3-stage grinding. After three stages of grinding, some grinding trajectories overlap, the grinding positioning accuracy is high, and the tool can be guaranteed to have good dimensional accuracy, resulting in good machining accuracy and surface roughness. Following the above method, adjust the parameters and process the second rear angle of the tool in the same way. The double rear angle design ensures that the tool has sufficient cutting edge strength while being able to perform high-feed, heavy-duty cutting.

[0046] Implementation Case Seven: Figure 8 As shown, this invention introduces a fine grinding and fine-tuning method, which consists of two stages: a smoothed connection point at the junction of the bottom cutting edge 4 and the forward progressive cutting edge 3, and a smoothed connection point at the junction of the cutting edge and the reverse cutting edge 2. According to the rake angle requirement of the bottom cutting edge 4, the V-wheel tilt angle is adjusted for fine grinding, extending into the helical groove of the forward progressive cutting edge 3. This is the first stage of fine grinding and fine-tuning, where the grinding wheel position is adjusted and the wheel is safely withdrawn radially. According to the design requirements of the rake angle of the top cutting edge 1, the V-wheel position is adjusted, transitioning from the reduced diameter area to the top cutting edge 1, where the rake angle is finely ground, extending into the helical groove of the reverse cutting edge 2. This is the second stage of fine grinding and fine-tuning, where the wheel is withdrawn radially. This effectively removes tool marks that may exist during initial machining and reduces the surface roughness of the tool.

[0047] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method of making a helical milling tool for machining a carbon fiber bore, the method comprising: The helical milling cutter comprises a shank, the shank is a reduced diameter shank, the shank is sequentially connected with a top cutting part (1), a reverse cutting part (2), a positive progressive cutting part (3) and a bottom cutting part (4) from bottom to top; the top cutting part (1) is concave arc-shaped; the reverse cutting part (2) is convex arc-shaped and adopts a left-hand cutting edge structure; the positive progressive cutting part (3) is conical or convex arc-shaped and adopts a right-hand cutting edge structure; the bottom cutting part (4) is a straight edge or a circular arc edge; and the preparation method of the helical milling cutter comprises the following steps: ​ S1, grinding the reduced diameter shank, selecting a flat grinding wheel, keeping the wheel center coaxial with the shank, and grinding the shank with the outer cylindrical surface of the flat grinding wheel, so that the diameter of the shank is reduced to the designed position, that is, the grinding of the reduced diameter is completed; S2, adopting a trochoid two-step grinding method to process the helical grooves of the bottom cutting part (4) and the positive progressive cutting part (3), that is, first adjusting the trochoid included angle of the grinding wheel to be equal to the rake angle of the bottom cutting part, determining the processing contact line, calculating the grinding track line according to the parameters of the grinding wheel, processing the helical groove of the bottom cutting part (4), then adjusting the trochoid included angle of the grinding wheel to be equal to the rake angle of the positive progressive cutting part, processing the helical groove of the positive progressive cutting part (3), and withdrawing to a safe position along the radial direction; S3, adopting a horizontal moving and vertical swinging three-step method to process the helical groove of the reverse cutting part (2) and the rake angle of the top cutting part (1), that is, first horizontally moving the flat grinding wheel, so that the cutting distance of the grinding wheel is 1 / 4r from the distance of the helical groove of the positive progressive cutting part (3), r is the tool radius; vertically swinging the grinding wheel to grind the angle equal to the rake angle of the reverse cutting part, processing the helical groove of the reverse cutting part (2); finally, vertically swinging the grinding wheel to grind the angle equal to the rake angle of the top cutting part, processing the top cutting part (1), and gradually reducing the cutting depth and withdrawing along the reduced diameter; S4, adopting a three-step grinding process to process the double clearance angle structure of the tool, first, adjusting the V-grinding wheel swing angle to meet the requirement of the first clearance angle of the bottom cutting part (4), using the side surface to process the first clearance angle of the bottom cutting part (4), and adjusting the posture to meet the parameter of the first clearance angle of the positive progressive cutting part (3), processing the first clearance angle of the positive progressive cutting part (3); second, horizontally moving the grinding wheel to determine the cutting contact line of the first clearance angle of the reverse cutting part (2), and processing to the smooth design area of the top cutting part (1); finally, withdrawing the grinding wheel to the top end of the reverse cutting part (2), adjusting the posture of the grinding wheel, and grinding the first clearance angle of the top cutting part (1) after the grinding path passes through the above-mentioned smooth design area again; according to the above-mentioned method, the second clearance angle of the tool is processed; S5, finally, fine grinding and fine adjustment are performed, the V-grinding wheel swing angle is adjusted for fine grinding according to the requirement of the rake angle of the bottom cutting part (4), the grinding wheel is adjusted to be in the helical groove of the positive progressive cutting part (3), the posture of the grinding wheel is adjusted, and the grinding wheel is safely withdrawn; the V-grinding wheel posture is adjusted according to the design requirement of the cutting rake angle of the top cutting part (1), the cutting edge rake angle is transitionally fine ground from the reduced diameter to the top cutting part (1), the grinding wheel is adjusted to be in the helical groove of the reverse cutting part (2), and the grinding wheel is withdrawn along the radial direction; S6. In the above processing steps, when the grinding wheel is involved in grinding, turn on the cutting fluid setting and adjust the axial position and radial spacing of the cutting fluid, as well as the cutting fluid height and angle, to the position suitable for grinding wheel. Observe the cutting color of the tool bar and adjust the cutting fluid speed and flow rate. If the chips turn black, increase the cutting speed and flow rate and decrease the grinding feed rate. If the chips are brown or blue, appropriately reduce or maintain the cutting fluid speed and flow rate settings.

2. The method of claim 1, wherein the helical milling tool is formed by: The reverse cutting edge (2) adopts a left-handed cutting edge, and the radial distance between it and the forward progressive cutting edge is 1 / 2r.

3. The method for preparing a spiral end mill for machining carbon fiber holes according to claim 1, characterized in that: The top cutting edge (1) and the reverse cutting edge (2) are tangentially transitioned by an arc or by a straight line, and are designed to be smooth.

4. The method for preparing a spiral end mill for machining carbon fiber holes according to claim 1, characterized in that: When the bottom cutting edge (4) adopts a straight edge structure or a circular arc edge structure, and when the forward progressive cutting edge (3) adopts a conical shape or a convex arc shape, a circular arc tangent transition or a straight line tangent transition is adopted, and both adopt a smoothing design treatment.

5. A method for preparing a spiral end mill for machining carbon fiber holes according to claim 1 or 4, characterized in that: When the positive progressive cutting edge (3) is conical, the angle between the conical cutting edge and the axis is 15°-25°, which is used for deep hole machining; or the angle between the conical cutting edge and the axis is 25°-45°, which is used for progressive milling; or the angle between the conical cutting edge and the axis is 45°-60°, which is used for hole reaming.

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