Ultrasonic left-right spiral staggered blade milling cutter for milling CFRP (carbon fiber reinforced plastic)
By designing an ultrasonic left-right helical staggered-edge milling cutter and combining it with ultrasonic vibration, the problems of material separation and cutting heat in CFRP milling were solved, achieving efficient cutting and high-quality machining results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-24
- Publication Date
- 2026-03-27
AI Technical Summary
In traditional milling of CFRP, material separation is difficult, the material tends to adhere to the tool surface, the cutting edge becomes dull, chip removal is difficult, burrs and tears easily appear on the upper surface of the material, and the cutting heat can easily cause thermal degradation of the resin, affecting the machining quality and the service performance of the component.
Design an ultrasonic left-right helical staggered-edge end mill, including a peripheral cutting edge unit and an end cutting edge unit. It adopts an upper and lower reverse helical chip removal groove, a biomimetic fish scale tooth structure and multiple chip breaking units, combined with ultrasonic vibration, to form a micro-cutting effect and periodic impact vibration, and optimize the axial force balance.
It significantly improves the chip breaking effect and chip removal efficiency of CFRP, reduces cutting heat accumulation and tool wear, and reduces delamination, tearing and burr defects, thus achieving high-quality CFRP milling.
Smart Images
Figure CN121732873A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of ultrasonic milling tool technology, and particularly relates to an ultrasonic left and right helical staggered cutting end mill for milling CFRP. Background Technology
[0002] Carbon fiber reinforced polymer (CFRP) composites are widely used in aerospace, transportation, and other fields due to their excellent specific strength, stiffness, and designability. The processing of carbon fiber materials has also received considerable attention. However, in traditional milling, because the matrix phase and adhesive layer of CFRP have similar properties and are both soft plastics that are difficult to machine, material separation during cutting is accompanied by significant plastic deformation and is difficult to break. This material easily adheres to the tool surface, leading to cutting edge dulling and chip removal difficulties. It also easily generates localized high temperatures at the material interface, causing resin thermal degradation, fiber pull-out, and other damage, severely affecting machining quality and component performance. Using tools with specific designs and in conjunction with ultrasonic-assisted machining can effectively improve the yield rate of CFRP milling. Ultrasonic vibration-assisted machining can improve surface quality, improve chip removal, reduce tool wear, reduce axial force, and reduce cutting heat accumulation, but there is a lack of tools that can be well integrated with ultrasonic vibration machining. In addition, since ordinary spiral end mills have only one direction of rotation, the upper and lower surfaces of the composite material are subjected to oblique upward cutting forces. The fiber layer on the lower surface of the material has better rigidity and is easy to be completely cut off, while the fiber layer on the upper surface of the material has reduced rigidity due to the lack of support from the material above, and is not easy to be completely cut off, so that burrs and tears are easy to appear on the upper surface of the workpiece.
[0003] Therefore, there is an urgent need for an ultrasonic left-right helical staggered-edge milling cutter for milling CFRP to solve the above problems. Summary of the Invention
[0004] The purpose of this invention is to provide an ultrasonic left-right helical staggered-edge milling cutter for milling CFRP, so as to solve the problems existing in the prior art.
[0005] To achieve the above objectives, the present invention provides the following solution: The present invention provides an ultrasonic left-right helical staggered-edge milling cutter for milling CFRP, comprising a shank portion and a cutting portion.
[0006] The cutting part includes a peripheral cutting edge unit and an end cutting edge unit. The peripheral cutting edge unit includes three first cutting edges arranged circumferentially. A chip removal groove is provided between two adjacent first cutting edges. The upper part and the lower part of the chip removal groove have opposite spiral directions. The end cutting edge unit is connected to the lower part of the chip removal groove.
[0007] The chip breaker structure includes a first chip breaker unit and two second chip breaker units, wherein two second chip breaker units are respectively provided on two first cutting edges, and a first chip breaker unit is provided on another first cutting edge, and the upper and lower helical directions of the second chip breaker units are opposite.
[0008] Preferably, the second chip breaking unit includes two sawtooth chip breaking grooves, which are respectively disposed on two of the first cutting edges. The upper part of the sawtooth chip breaking groove is a V-shaped left-hand helical sawtooth chip breaking groove, and the lower part of the sawtooth chip breaking groove is a V-shaped right-hand helical sawtooth chip breaking groove.
[0009] Preferably, the first chip-breaking unit includes a biomimetic fish-scale tooth structure and is disposed on another first cutting edge.
[0010] Preferably, the upper part of the chip removal groove is a right-handed chip removal groove, and the lower part of the chip removal groove is a left-handed chip removal groove.
[0011] Preferably, the end-cutting unit includes three second cutting edges distributed at equal intervals along the circumference, and a chip-receiving groove is provided between two adjacent second cutting edges. The chip-receiving groove is connected to the chip-removing groove, wherein one of the second cutting edges passes through the center of the tool, and the other two second cutting edges do not pass through the center of the tool.
[0012] Preferably, the cutting length of the upper part of the peripheral cutting unit is 27.5 mm, and the cutting length of the lower part of the peripheral cutting unit is 10 mm.
[0013] Preferably, the helix angle of the chip removal groove is 25°.
[0014] Preferably, the depth of the sawtooth chip breaker groove is 0.5 mm, the width is 1.5 mm, and the radius of the bottom arc is 0.3 mm. The V-shaped left-hand sawtooth spiral chip breaker groove is 55° left-handed, and the V-shaped right-hand sawtooth spiral chip breaker groove is 55° right-handed.
[0015] Preferably, the width of a single tooth in the biomimetic fish scale tooth structure is 5mm, and the radius of the bottom arc surface is 0.3mm.
[0016] Preferably, the axial rake angle of the chip groove is 5°, and the cutting edge width of the second cutting edge is 1mm, wherein one of the second cutting edges passes through the center of the tool by 0.4mm.
[0017] Compared with the prior art, the present invention has the following advantages and technical effects:
[0018] This invention provides an ultrasonic end mill with alternating left and right helical cutting edges for milling CFRP. Through a three-flute end mill structure design with chip-breaking grooves and biomimetic fish-scale teeth on the end and peripheral cutting surfaces, optimized tip rounding for wear reduction, and axial force balance configuration of the alternating upper and lower helical cutting edges, combined with the micro-cutting effect and periodic impact vibration generated during ultrasonic vibration-assisted machining, it further enhances chip breaking effect, accelerates chip removal efficiency, effectively reduces cutting heat accumulation and tool wear rate. Simultaneously, it utilizes the energy penetration characteristics of ultrasonic vibration to suppress internal stress concentration in the material, reducing defects such as delamination, tearing, and burrs, thereby achieving high-efficiency milling of carbon fiber reinforced composite materials. This invention, combining ultrasonic vibration, effectively enhances chip breaking effect, accelerates chip removal, reduces cutting heat accumulation and tool wear rate, suppresses internal stress concentration in the material, and significantly reduces delamination, tearing, and burr defects, achieving high-quality milling of CFRP. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;
[0021] Figure 2 This is a schematic diagram of the radial cross-section of the structure of the present invention;
[0022] Figure 3 This is a schematic diagram of the sawtooth chip breaking groove structure of the present invention;
[0023] Figure 4 This is a schematic diagram of the biomimetic fish scale tooth structure of the present invention;
[0024] The components are: 1. Tool holder; 2. First cutting edge; 3. Upper part of chip removal groove; 4. Lower part of chip removal groove; 5. Serrated chip breaking groove; 6. Bionic fish scale tooth structure; 7. Second cutting edge. Detailed Implementation
[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0026] 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.
[0027] Reference Figures 1-4 This invention provides an ultrasonic left-right helical staggered-edge milling cutter for milling CFRP, comprising a shank portion 1 and a cutting portion.
[0028] The cutting part includes a peripheral cutting edge unit and an end cutting edge unit. The peripheral cutting edge unit includes three first cutting edges 2 arranged circumferentially. A chip removal groove is provided between two adjacent first cutting edges 2. The upper part 3 and the lower part 4 of the chip removal groove have opposite spiral directions. The end cutting edge unit and the lower part 4 of the chip removal groove are connected.
[0029] The chip breaking structure includes a first chip breaking unit and two second chip breaking units. Two second chip breaking units are respectively provided on two first cutting edges 2, and a first chip breaking unit is provided on another first cutting edge 2. The upper and lower helical directions of the second chip breaking units are opposite.
[0030] In one embodiment of the invention, the chip removal groove adopts an upward and downward reverse spiral design. This structure can generate axial cutting forces in opposite directions during milling, thereby significantly reducing the overall axial resultant force and mitigating burrs and tearing caused by insufficient rigidity on the workpiece surface. Simultaneously, the connection design between the end-edge unit and the lower part of the chip removal groove ensures smooth chip discharge and avoids blockage. By configuring different types of chip-breaking units on different cutting edges, differentiated and synergistic chip-breaking functions are achieved. The second chip-breaking unit has opposite spiral directions at the top and bottom, further enhancing chip separation and chip-breaking effects. Especially under ultrasonic vibration assistance, it can more effectively break CFRP chips, reduce long fiber entanglement, and decrease cutting heat accumulation.
[0031] In one embodiment of the present invention, reference is made to Figure 2 The groove curve consists of two circular arcs. The radius of arc R1 is 1.5 mm, and the radius of arc R2 is 3 mm. The milling cutter has 3 teeth, an inter-tooth angle θ of 120°, a core thickness Wt of 6 mm, and a machining diameter D of 8 mm.
[0032] Reference Figure 3The spiral grooves, after unfolding along the helix, have a groove width Lr of 1.5mm, a bottom arc radius R3 of 0.3mm, a V-groove bevel angle θr of 25°, and a chip groove helix angle θp of 55°. The spiral chip groove not only improves upon the shortcomings of the overlapping groove cutting method, which requires multiple cutting edges for milling, allowing a single cutting edge to complete material removal, but also allows for recutting of the material by the remaining cutting edges, improving the surface quality of the workpiece. Furthermore, it can be set with a helix direction opposite to the chip removal groove, enabling each small chip removal groove to function as an alternating-edge milling cutter. With ultrasonic assistance, the serrated spiral groove can achieve better fiber cutting, reducing cutting force, improving the surface quality of the machined workpiece, and reducing tool wear.
[0033] Reference Figure 3 The cutting unit is composed of symmetrically staggered left and right helical grooves with a 25° left and right helix, and each cutting unit has a cutting width L4 of 5 mm. Composed of many cutting units, the cutting edge is sharp, which greatly reduces cutting resistance. Moreover, it can be combined with ultrasonic machining to achieve high-speed cutting, achieving the effect of milling instead of grinding. This improves the processing efficiency and surface quality of composite materials and extends the service life of the milling cutter.
[0034] As an optional implementation, the second chip breaking unit includes two sawtooth chip breaking grooves 5, which are respectively disposed on two first cutting edges 2. The upper part of the sawtooth chip breaking groove 5 is a V-shaped left-handed sawtooth spiral chip breaking groove, and the lower part of the sawtooth chip breaking groove 5 is a V-shaped right-handed sawtooth spiral chip breaking groove.
[0035] In one embodiment of the present invention, the second chip-breaking unit is specifically defined as a serrated chip-breaking groove, and its upper and lower parts are defined as left-handed and right-handed V-shaped helical structures, respectively. This design not only enhances the chip-breaking capability, but also forms an interlaced shearing action during the cutting process, further dispersing the cutting force and reducing local stress concentration. It is particularly suitable for high-frequency intermittent cutting under ultrasonic vibration, thereby improving the surface finish.
[0036] As an optional implementation, the first chip-breaking unit includes a biomimetic fish-scale tooth structure 6, disposed on another first cutting edge 2.
[0037] In one embodiment of the present invention, the first chip-breaking unit is a biomimetic fish-scale tooth structure. This structure has multiple micro-cutting edges, enabling a smoother cutting process and significantly reducing cutting resistance. With the assistance of ultrasonic vibration, the biomimetic fish-scale tooth structure can exert a "micro-ploughing" effect, which helps to obtain a smoother machined surface and is suitable for machining CFRP parts with high surface quality requirements.
[0038] As an optional implementation, the upper part 3 of the chip removal groove is a right-handed chip removal groove, and the lower part 4 of the chip removal groove is a left-handed chip removal groove.
[0039] In one embodiment of the present invention, the combination of the right-hand upper part and the left-hand lower part creates a vortex-like chip removal effect when the tool rotates, which is conducive to the smooth upward discharge of chips, while reducing the residence time of chips in the groove, reducing the risk of secondary cutting, and improving machining stability.
[0040] As an optional implementation, the end-cutting unit includes three second cutting edges 7 distributed at equal intervals along the circumference. A chip-receiving groove is provided between two adjacent second cutting edges 7, and the chip-receiving groove is connected to the chip-removing groove. One of the second cutting edges 7 passes through the center of the tool, while the other two second cutting edges 7 do not pass through the center of the tool.
[0041] In one embodiment of the invention, the use of a center cutting edge ensures that the tool has a certain drilling capability, enabling small-diameter or beveling machining; the absence of a center cutting edge enhances the strength of the tool tip and improves impact resistance. The chip groove and the chip removal groove are connected to form a continuous chip removal path, which is beneficial for the timely removal of chips during end milling.
[0042] As an optional implementation, the cutting length of the upper part of the peripheral cutting unit is 27.5 mm, and the cutting length of the lower part of the peripheral cutting unit is 10 mm.
[0043] In one embodiment of the present invention, the length configuration not only ensures sufficient effective cutting depth, but also optimizes the tool rigidity distribution through a shorter underload length, which is beneficial for maintaining good vibration suppression and machining accuracy in deep cavity or sidewall milling.
[0044] As an optional implementation, the helix angle of the chip removal groove is 25°.
[0045] In one embodiment of the present invention, 25° balances cutting sharpness and chip removal capability, which is beneficial to chip curling and removal while maintaining sufficient cutting edge strength. It is suitable for difficult-to-machine materials such as CFRP that require both sharp cutting and good chip removal.
[0046] As an optional implementation, the serrated chip breaker groove 5 has a depth of 0.5 mm, a width of 1.5 mm, and a bottom arc radius of 0.3 mm. The V-shaped left-hand serrated spiral chip breaker groove has a 55° left-hand rotation, and the V-shaped right-hand serrated spiral chip breaker groove has a 55° right-hand rotation.
[0047] In one embodiment of the present invention, the reasonable groove depth, groove width, and arc transition design can effectively break chips while avoiding chipping of the cutting edge caused by stress concentration. The 55° left-hand and right-hand helical design enhances the cutting guidance and chip removal smoothness of the groove shape, further improving chip breaking efficiency and tool life.
[0048] As an optional implementation, the biomimetic fish scale tooth structure 6 has a single tooth width of 5mm and a bottom arc radius of 0.3mm.
[0049] In one embodiment of the present invention, the microscopic geometric parameters of the biomimetic fish scale teeth are defined. The appropriate tooth width and arc radius design enable the structure to have good wear resistance and impact resistance while ensuring cutting sharpness. It is especially suitable for composite cutting of fiber and resin in CFRP and can effectively reduce burrs and tearing.
[0050] As an optional implementation, the axial rake angle of the chip groove is 5°, and the cutting edge width of the second cutting edge 7 is 1mm, wherein one of the second cutting edges 7 passes through the center of the tool by 0.4mm.
[0051] In one embodiment of the present invention, the rake angle and end-edge geometry of the chip groove are defined. The axial rake angle of 5° provides moderate cutting sharpness and edge strength. The 1mm cutting width ensures sufficient tool tip load-bearing capacity. The 0.4mm over-center design realizes the center cutting function and avoids the decrease in tool rigidity and increased vibration caused by excessive over-center amount, thereby improving the stability of the milling process.
[0052] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.
[0053] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. An ultrasonic left-right helical staggered-edge milling cutter for milling CFRP, comprising a shank (1) portion and a cutting portion, characterized in that: The cutting part includes a peripheral cutting edge unit and an end cutting edge unit. The peripheral cutting edge unit includes three first cutting edges (2) arranged in the circumferential direction. A chip removal groove is provided between two adjacent first cutting edges (2). The upper part (3) and the lower part (4) of the chip removal groove have opposite spiral directions. The end cutting edge unit and the lower part (4) of the chip removal groove are connected. The chip breaking structure includes a first chip breaking unit and two second chip breaking units, wherein two second chip breaking units are respectively provided on two first cutting edges (2), and a first chip breaking unit is provided on another first cutting edge (2), and the upper and lower helical directions of the second chip breaking units are opposite.
2. The ultrasonic left-right helical staggered-edge milling cutter for milling CFRP according to claim 1, characterized in that: The second chip breaking unit includes two sawtooth chip breaking grooves (5), and the two sawtooth chip breaking grooves (5) are respectively disposed on the two first cutting edges (2). The upper part of the sawtooth chip breaking groove (5) is a V-shaped left-hand sawtooth spiral chip breaking groove, and the lower part of the sawtooth chip breaking groove (5) is a V-shaped right-hand sawtooth spiral chip breaking groove.
3. The ultrasonic left-right helical staggered-edge milling cutter for milling CFRP according to claim 1, characterized in that: The first chip-breaking unit includes a biomimetic fish-scale tooth structure (6) disposed on another first cutting edge (2).
4. The ultrasonic left-right helical staggered cutting end mill for milling CFRP according to claim 1, characterized in that: The upper part (3) of the chip removal groove is a right-handed chip removal groove, and the lower part (4) of the chip removal groove is a left-handed chip removal groove.
5. An ultrasonic left-right helical staggered-edge milling cutter for milling CFRP according to claim 1, characterized in that: The end-cutting unit includes three second cutting edges (7) evenly spaced along the circumference. A chip-collecting groove is provided between two adjacent second cutting edges (7). The chip-collecting groove is connected to the chip-removing groove. One of the second cutting edges (7) passes through the center of the tool, while the other two second cutting edges (7) do not pass through the center of the tool.
6. The ultrasonic left-right helical staggered-edge milling cutter for milling CFRP according to claim 1, characterized in that: The cutting length of the upper part of the peripheral cutting edge unit is 27.5 mm, and the cutting length of the lower part of the peripheral cutting edge unit is 10 mm.
7. An ultrasonic left-right helical staggered-edge milling cutter for milling CFRP according to claim 1, characterized in that: The helix angle of the chip removal groove is 25°.
8. An ultrasonic left-right helical staggered-edge milling cutter for milling CFRP according to claim 2, characterized in that: The sawtooth chip breaker groove (5) has a depth of 0.5 mm, a width of 1.5 mm, and a bottom arc radius of 0.3 mm. The V-shaped left-hand sawtooth spiral chip breaker groove is 55° left-handed, and the V-shaped right-hand sawtooth spiral chip breaker groove is 55° right-handed.
9. An ultrasonic left-right helical staggered-edge milling cutter for milling CFRP according to claim 3, characterized in that: The biomimetic fish scale tooth structure (6) has a single tooth width of 5 mm and a bottom arc radius of 0.3 mm.
10. An ultrasonic left-right helical staggered-edge milling cutter for milling CFRP according to claim 5, characterized in that: The axial rake angle of the chip groove is 5°, and the cutting edge width of the second cutting edge (7) is 1mm, wherein the second cutting edge (7) passes through the center of the tool by 0.4mm.