A master-slave multi-edge staggered tooth milling tool structure with enhanced shearing and cutting capabilities

Abstract

A master-slave multi-edge staggered tooth milling cutter structure with enhanced shearing cutting function includes a left-hand main cutting edge, a right-hand main cutting edge, a left-hand main chip flute, a right-hand main chip flute, a left-hand micro-tooth, a left-hand micro-tooth follower edge, a right-hand micro-tooth, a right-hand micro-tooth follower edge, and other micro-tooths. Micro-tooth follower edges are cut into the cutting edge band of a conventional staggered tooth cutter, alternating with the main cutting edge to cut the material. When the cutter rotates, the left-hand and right-hand main cutting edges first shear the material at the upper and lower edges of the workpiece in a strongly constrained direction. The tough thermoplastic composite undergoes extrusion deformation under the cutting action, at which point the back support of the surface fibers is strengthened due to the extrusion deformation. Then, the left-hand and right-hand micro-tooth follower edges shear the remaining material again in a strongly constrained direction, repeating this process to achieve multiple enhanced shearing cuts on the material. This design helps remove material in a weakly constrained state at the surface, suppresses surface damage, and achieves low-damage milling of thermoplastic composites.

Description

Technical Field

[0001] This invention belongs to the field of milling tool technology in machining, and relates to a master-slave multi-bladed staggered tooth milling tool structure with enhanced shearing and cutting function. Background Technology

[0002] Carbon fiber reinforced thermoplastic composites (hereinafter referred to as "thermoplastic composites") have attracted increasing attention in the aerospace field due to their advantages such as lightweight, high strength, and better impact resistance. To meet the assembly and connection requirements of thermoplastic composite components, extensive edge milling is often required. However, thermoplastic composites are microscopically composed of high-strength carbon fibers and adhesive, heat-sensitive resins. The essence of processing thermoplastic composites is a co-cutting and removal process of fibers and resins. Due to the high plasticity and elongation at break of thermoplastic resins, the workpiece deforms more significantly during cutting, making it more difficult to cut the fibers. Uncut thermoplastic resins combine with the fibers, easily producing flaky flash damage on the surface. These irreversible damages result in poor processing quality, severely affecting the assembly accuracy and efficiency, thereby reducing the service performance of components and restricting the application of thermoplastic composites.

[0003] Due to the urgent need for high-performance composite materials in the aerospace field, many scholars at home and abroad have conducted extensive and fruitful research on the processing of thermoplastic composites. However, most of these studies focus on process optimization, and there is still no tool structure specifically designed for milling thermoplastic composites. Thermoplastic composites themselves are composed of fiber-reinforcing phases and resin matrix phases, which makes them anisotropic and heterogeneous. Furthermore, the toughness and thermal sensitivity of thermoplastic resins cause them to easily form unique elongated chips that adhere to the cutting tool during processing, resulting in poorer cutting ability. This makes their processing and damage patterns completely different from those of metals and traditional carbon fiber reinforced thermosetting composites (hereinafter referred to as "thermosetting composites"), and milling tools used for these two types are also unsuitable. For example, in their paper titled "Structural optimization method of multitooth cutter for surface damages suppression in edge trimming of Carbon Fiber Reinforced Plastics" published in Volume 46 of the Journal of Manufacturing Processes, Wang et al. optimized a microtooth cutter. The optimized cutter effectively suppressed milling damage on the surface of thermosetting composites under any machining parameters. However, when milling thermoplastic composites, this cutter exhibited severe chip adhesion, leading to significant machining damage. Similarly, Zhang Feng et al. of Guohong Tool Systems (Wuxi) Co., Ltd. published an invention patent in 2020, patent number "CN202011546388.7," entitled "A High-Efficiency Milling Cutting Tool for Heat-Resistant Alloys," specifically for milling titanium alloy bladed disks in the aero-engine field. However, this type of cutter did not consider the difficulty in cutting high-strength fibers and adhesive resins, and therefore could not effectively suppress flash damage generated on the surface during the milling of thermoplastic composites. Therefore, there is an urgent need to develop new types of cutting tools specifically designed for thermoplastic composites to meet the demand for high-quality and efficient milling of components. Summary of the Invention

[0004] This invention addresses the problem of burrs, flash, and other damage caused by the difficulty in effectively cutting the surface material under weak constraint during the milling of thermoplastic composites. It proposes a master-slave multi-tooth staggered-tooth milling tool structure with enhanced shearing capabilities. Specifically, by using left-hand and right-hand cutting edges arranged alternately, both the upper and lower surface layers of the composite can be sheared inwards simultaneously, ensuring the removal of material under strong constraint. Simultaneously, micro-toothed trailing edges with the same helix direction but different helix angles are formed on the master cutting edges (left and right helixes). When the tool rotates, the master cutting edge first shears the surface material in the direction of strong constraint. The tough thermoplastic composite undergoes extrusion deformation under the cutting action, strengthening the back support of the surface fibers. Then, the micro-toothed trailing edges with larger helix angles perform a second enhanced shearing cut in the direction of strong constraint, achieving multiple shearing cuts in the direction of strong constraint to effectively suppress surface milling damage.

[0005] The technical solution of the present invention:

[0006] A master-slave multi-edge staggered tooth tool structure with enhanced shearing and cutting function includes a main body and an improved part. The main body is a staggered tooth tool structure, including a left-hand main cutting edge 1, a right-hand main cutting edge 2, a left-hand main chip removal groove 3, and a right-hand main chip removal groove 4. The improved part consists of a left-hand micro-tooth 5, a left-hand micro-tooth follower edge 8, a right-hand micro-tooth 6, and a right-hand micro-tooth follower edge 7. The left-hand micro-tooth 5 is cut out in the cutting edge band of the left-hand main cutting edge 1, and the upper edge of the micro-tooth is modified to be a left-hand micro-tooth follower edge 8. The right-hand micro-tooth 6 is cut out in the cutting edge band of the right-hand main cutting edge 2, and the lower edge of the micro-tooth is modified to be a right-hand micro-tooth follower edge 7. The angle between the left-hand main cutting edge 1 and the milling cutter axis is P1, the angle between the right-hand main cutting edge 2 and the milling cutter axis is P2, the angle between the left-hand micro-tooth follower edge 8 and the milling cutter axis is P3, and the angle between the right-hand micro-tooth follower edge 7 and the milling cutter axis is P4. Figure 1 As shown, when the tool rotates, the left-hand micro-tooth follower edge 8 and the left-hand main cutting edge 1 cut alternately, while the right-hand micro-tooth follower edge 7 and the right-hand main cutting edge 2 cut alternately, producing a strengthened shearing effect.

[0007] Left-hand and right-hand micro-tooth trailing edges are respectively ground from the two main cutting edges of the milling cutter. Therefore, for the workpiece being machined, the main cutting edges and the micro-tooth trailing edges cannot function simultaneously, but rather cut the workpiece sequentially. To ensure that the tool can effectively perform its enhanced shearing cutting function, the shape and arrangement of the micro-tooth trailing edges need to be designed.

[0008] To ensure that no area of ​​the workpiece remains uncut during milling, the shape of the micro-tooth needs to be designed to prevent situations such as... Figure 2 The bladeless region shown. The shapes of its left-hand and right-hand micro-tooth trailing edges should satisfy the following formula:

[0009]

[0010] Wherein, s1 represents the length of the left-hand micro-tooth follow-cutting edge, s2 represents the length of the right-hand micro-tooth follow-cutting edge, j represents the width of the left-hand micro-tooth, l represents the width of the right-hand micro-tooth, e1 represents the width of the bladeless zone that may exist when the left-hand micro-tooth follow-cutting edge 8 and the left-hand main cutting edge 1 are arranged in combination, and e2 represents the width of the bladeless zone that may exist when the right-hand micro-tooth follow-cutting edge 7 and the right-hand main cutting edge 2 are arranged in combination.

[0011] Further derivation yields:

[0012] jcosP3=s1 cosP1 (3)

[0013] lcosP2=s2 cosP4 (4)

[0014] To ensure that every point on the workpiece can be cut by the main cutting edge and the micro-tooth follower edge during milling, the arrangement of the micro-tooths needs to be designed, such as... Figure 3 As shown. The positions of the micro-tooth and the main cutting edge should satisfy the following formula:

[0015] j i =m1=s (5)

[0016]

[0017] l i =n1=q (8)

[0018]

[0019] In the formula, i represents the i-th cutting edge, n represents the total number of cutting edges, g and f are constants, m represents the distance from the first left-hand micro-tooth follower edge to the tip of the left-hand main cutting edge, j represents the width of the left-hand micro-tooth, r represents the spacing between the left-hand micro-tooths, n represents the distance from the first right-hand micro-tooth follower edge to the tip of the right-hand main cutting edge, l represents the width of the right-hand micro-tooth, and k represents the spacing between the right-hand micro-tooths.

[0020] The main cutting edge and the micro-toothed trailing edge are distributed alternately, and the micro-toothed trailing edges on different cutting edges are also distributed alternately in the horizontal direction. This ensures that the material is cut by both the main cutting edge and the micro-toothed trailing edge in one revolution of the tool, guaranteeing the realization of enhanced shearing cutting function. However, when g > n-1, it can be observed that there will be areas covered only by the main cutting edge, and when... At this point, there will be a situation where only the micro-tooths are covered by the cutting edge; these are two extreme cases of micro-tooth arrangement. Therefore, as long as the spacing between the micro-tooths is not less than... A micro-tooth width of n times, not exceeding n-1 times the micro-tooth width, can ensure that every part of the material on the workpiece is subjected to enhanced shearing and cutting.

[0021] The selection of the helix angle P1 of the left-hand main cutting edge and the helix angle P2 of the right-hand main cutting edge is related to the chip removal effect of the tool, and should be reasonably selected between 15° and 45°; the selection of the helix angle P3 of the left-hand micro-tooth trailing edge and the helix angle P4 of the right-hand micro-tooth trailing edge is related to the shearing and cutting effect of the tool, and should be reasonably selected between 30° and 90°.

[0022] The widths of left-hand and right-hand micro-tooths directly affect their chip removal efficiency. If the width is too small, insufficient chip removal space will lead to chip adhesion and blockage, causing a rapid decline in tool cutting performance. Therefore, the width j of the left-hand micro-tooth should be appropriately selected between 0.2 and 4.2 mm, and the width l of the right-hand micro-tooth should also be appropriately selected between 0.2 and 4.2 mm.

[0023] As the tool rotates, the left-hand and right-hand main cutting edges successively shear and cut the material at the upper and lower edges of the workpiece in the direction of strong constraint. However, for material in a weakly constrained state at the surface, some material may not be effectively removed, and this unremoved material may be compressed and deformed towards the workpiece centerline under the action of the main cutting edges. The back support of the surface material is strengthened due to this compression deformation. Then, the left-hand and right-hand micro-tooth trailing edges further shear and remove the remaining material in the direction of strong constraint, achieving a secondary strengthening shear removal of the material. Furthermore, due to the different helix angles of the main cutting edges and the micro-tooth trailing edges, the unremoved material oscillates back and forth, which is conducive to the propagation of fatigue cracks in high-toughness thermoplastic resins, thus effectively removing them and facilitating low-damage milling of thermoplastic composites.

[0024] The beneficial effects of this invention are as follows: This invention proposes a master-slave multi-edge staggered tooth tool structure with enhanced shear cutting function. This tool achieves enhanced shear cutting function by creating micro-toothed trailing edges with the same helical direction but different helical angles on the master cutting edge. Under this function, material in a weakly constrained state on the surface is effectively removed by the shear cutting action of the master cutting edge and the micro-toothed trailing edges in the direction of strong constraint, thereby effectively suppressing surface damage. The structure involved in this invention is simple and easy to manufacture. Its application helps to achieve high-quality and high-efficiency milling of thermoplastic composites and promotes the application of thermoplastic composites. Attached Figure Description

[0025] Figure 1 It is a master-slave multi-bladed staggered tooth cutting tool structure.

[0026] Figure 2 The diagram shows the specific shape of the micro-tooth on the cutting tool, where (a) is a left-handed micro-tooth cutting edge and (b) is a right-handed micro-tooth cutting edge.

[0027] Figure 3The diagram shows the arrangement of the micro-teeth on the cutting tool, where (a) is a schematic diagram of the overall cutting tool and (b) is a planar unfolded diagram of the cutting tool.

[0028] Figure 4 For the experimental verification of the effect of the present invention, (a) is the surface and (b) is the surface layer.

[0029] In the diagram: 1. Left-hand main cutting edge, 2. Right-hand main cutting edge, 3. Left-hand main chip flute, 4. Right-hand main chip flute, 5. Left-hand micro tooth, 8. Left-hand micro tooth follower edge, 6. Right-hand micro tooth, 7. Right-hand micro tooth follower edge, P1. Helix angle of left-hand main cutting edge, P2. Helix angle of right-hand main cutting edge, P3. Helix angle of left-hand micro tooth follower edge, P4. Helix angle of right-hand micro tooth follower edge, m. Distance of left-hand micro tooth from the tip of left-hand main cutting edge, j. Width of left-hand micro tooth, r. Spacing of left-hand micro teeth, n. Distance of right-hand micro tooth from the tip of right-hand main cutting edge, l. Width of right-hand micro tooth, k. Spacing of right-hand micro teeth. Detailed Implementation

[0030] The following description, in conjunction with the accompanying drawings and technical solutions, details the specific implementation of the master-slave multi-bladed interlaced tooth structure with enhanced shearing and cutting function involved in this solution.

[0031] like Figure 1 As shown, this invention is a master-slave multi-tooth staggered tooth tool structure with enhanced shearing and cutting function. Its main features include a left-handed main cutting edge 1, a right-handed main cutting edge 2, a left-handed main chip removal groove 3, and a right-handed main chip removal groove 4. The improved parts consist of left-handed micro-tooths 5, right-handed micro-tooths 6, right-handed micro-tooth trailing edges 7, and left-handed micro-tooth trailing edges 8. The left-handed main cutting edge 1 and the right-handed main cutting edge 2 first shear and cut the material at the upper and lower edges of the workpiece in a strongly constrained direction. Then, the left-handed micro-tooth trailing edges 8 and the right-handed micro-tooth trailing edges 7 further shear and cut the remaining material in a strongly constrained direction, achieving multiple enhanced shearing and removal of the material. Furthermore, due to the different helix angles of the main cutting edge and the micro-tooth trailing edges, the remaining material oscillates up and down, which is beneficial for the propagation of fatigue cracks in the material and helps remove tough thermoplastic resin materials, effectively suppressing processing damage.

[0032] Thermoplastic composites possess strong resin plasticity and high elongation at break, leading to greater workpiece deformation during machining and making fiber cutting more difficult. Uncut thermoplastic resin and fibers combine, easily causing flaky flash-like damage on the surface. These irreversible damages result in poor processing quality, severely impacting the assembly accuracy and efficiency of components. Since engineering applications demand extremely high processing precision for thermoplastic composites, a verification experiment was conducted using carbon fiber reinforced polyetheretherketone (PEEK) composites as an example to verify the milling effect of this invention.

[0033] A 10mm nominal diameter three-flute master-slave multi-flute staggered-tooth end mill was used, with a left-hand main cutting edge helix angle of 25° and a right-hand main cutting edge helix angle of 35°. Both the left-hand and right-hand micro-tooth helix angles were 25° each. The left-hand micro-tooth width was 1.8mm, and the right-hand micro-tooth width was 1.6mm. The cutter was uncoated. The selected material was an 8mm multi-directional layered carbon fiber reinforced polyetheretherketone (PEEK) composite material sheet manufactured by Jiangsu Junhua Engineering Plastics Products Co., Ltd. The machining parameters were a spindle speed of 4000 rpm and a feed rate of 300mm / min.

[0034] Using the aforementioned cutting tools, workpieces, and milling parameters, dry milling experiments can effectively suppress milling damage, such as... Figure 4 The surface burr length is ≤0.2mm, the surface roughness is ≤3.2μm, and the milling distance is about 2.2m. Compared with ordinary milling cutters for composite materials, this tool has a longer service life when milling thermoplastic composite materials.

Claims

1. A master-slave multi-edge staggered tooth milling tool structure with enhanced shearing and cutting function, characterized in that, The master-slave multi-edge staggered tooth milling tool structure includes a main body and an improved part; the main body is a staggered tooth tool structure, including a left-hand main cutting edge (1), a right-hand main cutting edge (2), a left-hand main chip evacuation groove (3), and a right-hand main chip evacuation groove (4); the improved part includes a left-hand micro tooth (5), a right-hand micro tooth (6), a right-hand micro tooth follower edge (7), and a left-hand micro tooth follower edge (8); the left-hand micro tooth (5) is cut out in the cutting edge of the left-hand main cutting edge (1), and the upper edge of the micro tooth is modified to be a left-hand micro tooth follower edge (8); the right-hand micro tooth (6) is cut out in the cutting edge of the right-hand main cutting edge (1); 2) The cutting edge is opened from the middle, and the lower edge of the micro tooth is modified to be a right-hand micro tooth follower edge (7). The angle between the left-hand main cutting edge (1) and the milling cutter axis is P1, the angle between the right-hand main cutting edge (2) and the milling cutter axis is P2, the angle between the left-hand micro tooth follower edge (8) and the milling cutter axis is P3, and the angle between the right-hand micro tooth follower edge (7) and the milling cutter axis is P4. When the tool rotates, the left-hand micro tooth follower edge (8) and the left-hand main cutting edge (1) cut alternately, and the right-hand micro tooth follower edge (7) and the right-hand main cutting edge (2) cut alternately, producing a strengthened shearing cutting effect. The shapes of the left-handed micro-tooth trailing edge (8) and the right-handed micro-tooth trailing edge (7) should satisfy the following formula: ； ； Wherein, s1 represents the length of the left-hand micro-tooth trailing edge (8), s2 represents the length of the right-hand micro-tooth trailing edge (7), j represents the width of the left-hand micro-tooth (5), l represents the width of the right-hand micro-tooth (6), e1 represents the width of the bladeless area that may exist when the left-hand micro-tooth trailing edge (8) and the left-hand main cutting edge (1) are arranged in combination, and e2 represents the width of the bladeless area that may exist when the right-hand micro-tooth trailing edge (7) and the right-hand main cutting edge (2) are arranged in combination; Further derivation yields: ； ； To ensure that every point on the workpiece can be cut by the main cutting edge and the micro-tooth follower edge during milling, the arrangement of the micro-tooths needs to be designed; the positions of the micro-tooths and the main cutting edge should satisfy the following formula: ； ； ； ； ； ； In the formula, i represents the i-th cutting edge, n represents the total number of cutting edges, g and f are constants, and j i Let m1 be the width of the left-handed micro-tooth on the i-th left-handed main cutting edge; m1 represents the distance from the cutting edge of the first left-handed micro-tooth on the first left-handed main cutting edge to the tip of the left-handed main cutting edge; m i represents the distance from the tip of the first left-hand micro-tooth on the i-th left-hand main cutting edge to the tip of the left-hand main cutting edge; s represents a constant; r i The spacing of the left-handed micro-teeth on the i-th left-handed main cutting edge; l i v1 represents the width of the right-hand micro-tooth on the i-th right-hand main cutting edge; v1 represents the distance from the tip of the first right-hand micro-tooth cluster on the first right-hand main cutting edge; v i q represents the distance from the tip of the first right-handed micro-tooth cluster on the i-th right-handed primary cutting edge; k represents a constant; k represents the distance from the tip of the right-handed cutting edge. i This represents the spacing between the right-handed micro-teeth on the i-th right-handed main cutting edge; At the same time, ensure that the spacing between the micro-teeth is not less than The width of the micro-tooth is twice that of the micro-tooth.

2. The master-slave multi-edge staggered tooth milling tool structure with enhanced shearing and cutting function according to claim 1, characterized in that, The helix angle P1 of the left-hand main cutting edge (1) and the helix angle P2 of the right-hand main cutting edge (2) are selected between 15° and 45°; the helix angle P3 of the left-hand micro-tooth follower edge (8) and the helix angle P4 of the right-hand micro-tooth follower edge (7) are selected between 30° and 90°.

3. The master-slave multi-bladed staggered tooth milling tool structure with enhanced shearing and cutting function according to claim 1, characterized in that, The width j of the left-handed micro-tooth (5) is selected between 0.2 and 4.2 mm, and the width l of the right-handed micro-tooth (6) is selected between 0.2 and 4.2 mm.

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