Design method and application of fractal tree microstructure chip breaking tool

Abstract

The invention discloses a fractal tree microstructure chip breaking tool design method and application, the tool comprises a tool base body, the tool base body comprises a front tool face and a rear tool face, and a fractal tree microstructure, a chip breaking groove and a chip breaking table are sequentially arranged along the front tool face. The fractal tree microtexture can reduce the cutter-chip contact area and can also serve as a flow guide groove of cutting fluid, the heat dissipation performance of the cutter is improved, meanwhile, the chip breaking performance of the cutter is improved by designing the chip breaking grooves and the chip breaking tables, and chips and abrasive dust are prevented from being retained on the front cutter face of the cutter. Through mutual cooperation of the fractal tree microtexture, the chip breaking grooves and the chip breaking tables, the cutting force and the cutting temperature can be reduced, tool abrasion is relieved, the service life of a tool is prolonged, and the tool is suitable for machining of materials difficult to machine.

Description

Technical Field

[0001] The present invention relates to the technical field of cutting tools, and particularly to a design method and application of a fractal tree micro-textured chip-breaking tool. Background Art

[0002] With the increasing requirements for machining quality and efficiency in modern manufacturing, the cutting performance of traditional tools has been difficult to meet the needs of complex machining conditions. Micro-texture technology has become a hot topic in tool research and development due to its advantages such as improving chip flow, reducing cutting force, and extending tool life.

[0003] Some existing technologies have verified the improvement of tool performance by micro-texture technology. For example, Patent CN117961181A discloses a bionic micro-textured tool for realizing the directional flow of cutting fluid and its manufacturing method. By setting bionic micro-textures on the rake face of the tool, it plays a role in directionally transporting the cutting fluid, making the distribution of the cutting fluid at the cutting edge of the tool denser, forming a cutting fluid film on the tool-chip contact surface, improving the heat dissipation and lubrication performance of the tool, extending the service life of the tool, and also improving the quality of the machined surface. However, the shape design of the micro-texture in this method is relatively simple, and the role of the multi-level structure is not fully considered. In addition, there are also some journal papers, such as "Research on Surface Texture Design and Tribological Properties Based on Fractal Geometry" and "Research on Tooth Surface Micro-Texture Design and Load-Bearing Characteristics Based on Fractal Theory", which show that the fractal structure has excellent anti-friction and anti-adhesion properties, but its application in actual tool design has not been reported in detail.

[0004] It is necessary to design a more scientific tool with micro-textures based on fractal theory, optimize the tool structure, and improve the cutting performance and service life of the tool. Summary of the Invention

[0005] The purpose of the present invention is to optimize the structure of the tool surface, improve the heat dissipation performance through the fractal tree micro-texture, and at the same time design a chip-breaking groove and a chip-breaking platform to improve the chip-breaking performance of the tool, prevent chips and abrasive debris from remaining on the rake face of the tool, achieve the reduction of cutting temperature and cutting force, reduce tool wear, and extend the service life of the tool.

[0006] To achieve the above purpose, the present invention provides a fractal tree micro-textured chip-breaking tool, including a tool substrate, the tool substrate includes a rake face and a flank face, and a fractal tree micro-texture and a chip-breaking groove are sequentially arranged along the rake face; There is an inclination angle on the rake face at the distribution positions of the fractal tree micro-texture and the chip-breaking groove.

[0007] Furthermore, the fractal tree micro-texture is composed of several micro-texture units, and each micro-texture unit is composed of a main trunk, branches, and lateral buds. Among them, the depths of the main trunk, branches, and lateral buds are 10 - 50 μm, and the lengths and widths of the main trunk, branches, and lateral buds gradually decrease; The lateral buds of the micro-texture units are distributed towards the rake face, and the micro-texture units increase gradually along the rake face. The spacing between adjacent levels and adjacent micro-texture units in each level is 100 - 220 μm; in each level, the distance from the branch point at the end of the main trunk of the outermost micro-texture unit to the cutting edge is 100 - 300 μm; The chip breaker is 80 - 120 μm away from the micro-texture units of the last level.

[0008] In the micro-texture units, the main trunk has the largest area, which can reduce the contact area between the tool and the workpiece, store granular chips to reduce the cutting force between the tool and the workpiece, and reduce the friction force. When the side branches and lateral buds are immersed in the cutting fluid, a hydrodynamic lubricating film will be formed on the tool surface to reduce the friction force between the tool and the workpiece and between the tool and the chip, reduce tool wear, and can become micro-channels for the cutting fluid on the tool surface to further reduce tool wear. The two interact with each other to maximize the effect of the fractal tree micro-texture.

[0009] Further, the length, width, and depth of the chip breaker are 600 - 800 μm, 150 - 300 μm, and 20 - 40 μm respectively; The bottom of the chip breaker has an inclined angle of 120 - 150°.

[0010] Further, a chip breaking platform surrounding the tool substrate is provided at the end of the chip breaker.

[0011] Further, the width and height of the chip breaking platform are 100 - 200 μm and 50 - 150 μm respectively.

[0012] The present invention also provides a design method for the above-mentioned fractal tree micro-texture chip breaking tool, including, Obtaining the cutting parameters of the object; Designing the basic structures of the fractal tree micro-texture and the chip breaker based on the cutting parameters and tool parameters; Using a laser to process on the tool surface to obtain the fractal tree micro-texture chip breaking tool.

[0013] Further, the fractal tree micro-texture is designed by using the L-system algorithm.

[0014] Further, the optimization is carried out by using finite element simulation; After optimizing the structure of the fractal tree micro-texture, design the basic structures of the chip breaker and the chip breaking platform, and reconstruct the finite element simulation model again to optimize the chip breaker and the chip breaking platform.

[0015] Further, optimize the basic structures of the chip breaker and the chip breaking platform by simulating chip flow.

[0016] The present invention also provides an application of the above fractal tree micro-textured chip-breaking tool in the field of cutting.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The fractal tree micro-texture of the present invention can reduce the tool-chip contact area and also serve as a diversion channel for the cutting fluid, which is beneficial to improving the heat dissipation performance of the tool. Designing a chip-breaking groove and a chip-breaking platform can enhance the chip-breaking performance of the tool and prevent chips and abrasive debris from staying on the rake face of the tool. Through the mutual cooperation of the fractal tree micro-texture, the chip-breaking groove and the chip-breaking platform, the present invention can reduce the cutting force and cutting temperature, slow down the tool wear, extend the tool service life, and is suitable for the machining of difficult-to-machine materials. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 Shows a schematic structural diagram of the fractal tree micro-textured chip-breaking tool designed in the embodiment; Figure 2 Shows a detailed view of the fractal tree micro-texture; Figure 3 Shows a cross-sectional view of the chip-breaking groove and the chip-breaking platform; Figure 4 Shows a schematic structural diagram of the tool with a fractal tree micro-texture in Comparative Example 1; Figure 5 Shows a schematic structural diagram of the chip-breaking tool in Comparative Example 2; Figure 6 Shows a schematic structural diagram of a common triangular turning tool in Comparative Example 3; Figures 7(a), 7(b), and 7(c) respectively show the cutting simulation cutting force result diagrams of the tools in the embodiment and the comparative examples under the feed rates of 0.12, 0.15, and 0.18 mm / r; Figures 8(a), 8(b), and 8(c) respectively show the simulation diagrams of three stages from chip generation to chip breakage when the tool in the embodiment is cutting; Figures 9(a), 9(b), and 9(c) respectively show the simulation diagrams of three stages from chip generation to chip breakage when the tool in Comparative Example 1 is cutting; Figures 10(a), 10(b), and 10(c) respectively show the simulation diagrams of three stages from chip generation to chip breakage when the tool in Comparative Example 2 is cutting; Figures 11(a), 11(b) and 11(c) respectively show the simulation diagrams of three stages from chip generation to breakage when cutting the tool of Comparative Example 3; Explanation of reference numerals: 1. Tool substrate; 2. Fractal tree micro-texture; 3. Chip breaker groove; 4. Chip breaker platform. Specific embodiments

[0020] In the ranges disclosed in the present invention, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and a single point value, and between single point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in the present invention.

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the specific embodiments of the present invention and the drawings of the specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] Embodiment A design method for a fractal tree micro-textured chip-breaking tool includes the following steps: Step 1. Obtain the cutting parameters of the material.

[0023] The cutting performance of the tool in the machining material can be obtained through historical data or by constructing finite element simulation data. The material can be a difficult-to-machine metal or other materials.

[0024] Step 2. Design the basic structure of the fractal tree micro-texture.

[0025] Based on the basic parameters of the tool substrate, such as the material and structure of the tool, combined with the cutting parameters obtained in Step 1, use the L-system algorithm to recursively generate a two-dimensional geometric model containing one or more fractal tree micro-textures, and then use computer-aided design software to construct the basic model of the tool with fractal tree micro-textures.

[0026] As an implementation, assume that the width of the rake face of the tool is W_tool, the length of the rake face of the tool is L_tool, the width of the main cutting edge is W_cutting_edge, and the distance from the position of the main cutting edge to the margin of the rake face of the tool is B_edge. The recursive iteration process of the L-system algorithm is as follows: 1. L-system initial string and rule setting: Initial String (Axiom): 'X' (X represents the starting structure of the fractal tree).

[0027] Production Rules: rules = containers.Map({'X', 'F'}, {'F+[[X]-X]-F[-X]+X', 'FF'}); Among them, X represents the main trunk of the fractal tree, and F represents drawing a branch.

[0028] 2. Fractal Tree Parameter Design: The length of the main trunk L1 = W_tool / 5, and the width W1 = W_tool / 15.

[0029] The length of the side branch L2 = L1*0.5, and the width W2 = W1*0.6.

[0030] The length of the side bud L3 = L2*0.5, and the width W3 = W2*0.5.

[0031] The angle of the branch angle_increment = 20°.

[0032] The branch spacing D = 200μm.

[0033] The depth of the micro-texture H = 50μm.

[0034] The number of iterations of the fractal tree iterations = 3 (can be adjusted according to the tool design).

[0035] 3. Generating the Fractal Tree through L-system: Use the L-system rules to recursively generate a string and map the string to a graphic operation.

[0036] Update the string at each iteration. The number of iterations is determined by the size and performance requirements of the tool. The number of iterations and the branch angle can be adjusted according to the experimental results.

[0037] 4. Combining L-system with the Tool Substrate: Combining the fractal tree structure with the tool substrate: In the generated fractal tree structure, by adjusting the relative position of the tree shape, ensure that the fractal tree micro-texture is distributed in the rake face area of the tool substrate.

[0038] Step 3: Optimize the layout and parameters of the fractal tree micro-texture.

[0039] Two finite element simulation models are constructed for the cutting tools with and without the fractal tree micro-texture. According to the finite element simulation models, the equivalent stress and cutting force of the workpiece during cutting with the two types of cutting tools are obtained, and based on the equivalent stress and cutting force of the workpiece, the distribution of the fractal tree micro-texture is continuously optimized. According to the simulation results, the geometric parameters and distribution positions of the preliminarily optimized fractal tree micro-texture are obtained.

[0040] The distribution position of the fractal tree micro-texture includes the number of layers of the fractal tree micro-texture and the number of the fractal tree micro-texture in each layer. The geometric parameters of the fractal tree micro-texture include the lengths of the main trunk, side branches, and lateral buds, as well as the angles of inclination of the side branches relative to the main trunk and the angles of inclination of the lateral buds relative to the side branches.

[0041] Step 4: Design and optimize the chip breaker groove and chip breaker platform.

[0042] 1. According to the simulated cutting process of the cutting tool with the fractal tree micro-texture in Step 3, the length and thickness of the chip are obtained, and the distribution positions and geometric parameters of the chip breaker groove and chip breaker platform are preliminarily designed. Among them, the distribution position of the chip breaker groove is the distance between the chip breaker groove and the fractal tree micro-texture, the distribution position of the chip breaker platform is the distance between the chip breaker platform and the chip breaker groove, the geometric parameters of the chip breaker groove are the groove width and groove depth of the chip breaker groove, and the geometric parameters of the chip breaker platform are the platform height and platform width of the chip breaker platform.

[0043] 2. Input the distribution positions and geometric parameters of the preliminarily designed chip breaker groove and chip breaker platform into the finite element model to simulate the chip flow. According to the chip flow effect, adjust the distribution positions and geometric parameters of the chip breaker groove and chip breaker platform until the chip control effect reaches a certain level, and the optimized parameters of the chip breaker groove and chip breaker platform are obtained.

[0044] Step 5: Laser processing and structure optimization.

[0045] The femtosecond laser ablation technology is used to process the fractal tree micro-texture, chip breaker groove, and chip breaker platform on the rake face of the tool substrate, and the processing accuracy and surface quality of the fractal tree micro-texture, chip breaker groove, and chip breaker platform are secondarily optimized through the micro-nano etching technology.

[0046] After the above steps, the fractal tree micro-texture chip-breaking tool as shown in Figure 1 is obtained, which includes a tool substrate 1. The tool substrate 1 includes a rake face and a flank face. Along the rake face, a fractal tree micro-texture 2, a chip breaker groove 3, and a chip breaker platform 4 surrounding the tool substrate 1 are sequentially arranged. As shown in Figure 2As shown, the fractal tree micro-texture 2 is composed of 10 micro-texture units. Each micro-texture unit is composed of a main trunk, branches, and lateral buds. The lateral buds of the micro-texture unit are distributed towards the rake face, and the micro-texture units increase gradually along the rake face, with a total of 4 levels. The spacing between adjacent micro-texture units in each level is 220 μm; in each level, the distance from the branch point at the end of the main trunk of the outermost micro-texture unit to the cutting edge is 150 μm. The depths of the main trunk, branches, and lateral buds in each micro-texture unit are 50 μm; the lengths of the main trunk, branches, and lateral buds are 200 μm, 100 μm, and 50 μm in sequence; the widths of the main trunk, branches, and lateral buds are 60 μm, 30 μm, and 15 μm in sequence; the angle of the branches is 30°.

[0047] As Figure 3 shown, the depth of the bottom of the chip breaker groove 3 is 26 μm and it has an inclination angle of 138°. The chip breaker platform 4 is arranged at the end of the chip breaker groove 3 and there is no spacing from the chip breaker groove 3.

[0048] Comparative Example 1 As Figure 4 shown, for the tool with the fractal tree micro-texture, compared with the embodiment, the difference is that no chip breaker groove and chip breaker platform are designed after the fractal tree micro-texture.

[0049] Comparative Example 2 As Figure 5 shown, for the chip breaking tool, compared with the embodiment, no fractal tree micro-texture is machined on the rake face.

[0050] Comparative Example 3 As Figure 6 shown, for the ordinary triangular turning tool, compared with the embodiment, no fractal tree micro-texture, chip breaker groove, and chip breaker platform surrounding the tool substrate are machined on the rake face.

[0051] Figures 7(a)-7(c) respectively show the variation of the cutting force of the tool with time for the example, Comparative Example 1, Comparative Example 2, and Comparative Example 3 when the feed rate is 0.12 mm / r, 0.15 mm / r, and 0.18 mm / r, and other conditions such as the cutting material are the same. In these figures, T1, T2, T3, and T4 respectively represent the tools of the example, Comparative Example 1, Comparative Example 2, and Comparative Example 3. It can be seen that the main cutting force of the tool in the example is significantly lower than that of the comparative examples at different feed rates. However, due to the effect of the chip breaker groove, the main cutting force fluctuates greatly when the chip breaks in the tool of the example and then returns to stability. The dry cutting processes of the example and the comparative examples were also simulated. Figures 8 to 11 show the dynamic chip generation process when each tool cuts at a feed rate of 0.12 mm / r, which shows three stages from chip generation to breakage, indicating that the chip breaker groove and the chip breaker platform of the tool in the example have good chip breaking ability. The tool in the example can not only reduce the cutting force under dry cutting but also achieve the chip breaking function, indicating that the fractal tree micro-texture and the chip breaker groove have good coupling effects. Even though the instantaneous cutting force will increase during the chip breaking process, it still does not affect the good coupling effects of the fractal tree micro-texture, the chip breaker groove, and the chip breaker platform.

[0052] These results show that the fractal tree micro-texture chip breaking tool constructed in the example can not only improve the cutting performance of the tool but also couple the chip breaker platform and the chip breaker groove to improve its chip breaking performance.

[0053] The components and methods not described in detail in the present invention are all prior arts and will not be elaborated here.

[0054] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fractal tree micro-texture chip breaking tool, characterized in that: The tool comprises a tool base body, wherein the tool base body comprises a front cutting surface and a rear cutting surface, and a fractal tree micro-texture and a chip breaker groove are sequentially arranged along the front cutting surface.

2. The fractal tree micro-textured chip breaker tool according to claim 1, characterized in that: The fractal tree microtexture is composed of a plurality of microtexture units, and the microtexture units are composed of a trunk, branches and side buds, wherein the depth of the trunk, branches and side buds is 10-50 μm, and the length and width of the trunk, branches and side buds gradually decrease; The side buds of the micro-texture units are distributed toward the rake face, and the micro-texture units are increased step by step along the rake face, and the spacing between adjacent levels and adjacent micro-texture units in each level is 100-220 μm; in each level, the branch point at the end of the trunk of the outermost micro-texture unit is 100-300 μm away from the cutting edge; The distance between the chip breaker and the micro-texture unit at the end level is 80-120 μm.

3. The fractal tree micro-textured chip breaking tool according to claim 1, characterized in that: The length, width and depth of the chip breaker groove are 600-800 μm, 150-300 μm and 20-40 μm respectively; The bottom of the chip breaker groove has an inclination angle of 120-150°.

4. The fractal tree micro-textured chip breaking tool according to claims 1-3, characterized in that: A chip breaking platform surrounding the tool base is also arranged at the end of the chip breaking groove.

5. The fractal tree micro-textured chip breaking tool according to claim 1, characterized in that: The width and height of the chip breaker are 100-200 μm and 50-150 μm respectively.

6. A method for designing a fractal tree micro-texture chip breaker tool as claimed in any one of claims 1 to 5, characterized in that: include, Get the cutting parameters of the material; Design and optimize the basic structure of fractal tree microtexture based on cutting parameters and tool parameters; The tool surface is processed by laser to obtain a fractal tree micro-textured chip breaking tool.

7. The design method of the fractal tree micro-texture chip breaker tool according to claim 6, characterized in that: The fractal tree micro-texture is designed by using an L-system algorithm.

8. The design method of the fractal tree micro-texture chip breaker tool according to claim 6, characterized in that: The optimization is performed using finite element simulation; After the structure of the fractal tree microtexture is optimized, the basic structure of the chip breaker groove and chip breaker table is designed, and the finite element simulation model is constructed again to optimize the chip breaker groove and chip breaker table.

9. The design method of the fractal tree micro-texture chip breaker tool according to claim 8, characterized in that: The basic structure of the chip breaker and chip breaker table is optimized by simulating the chip flow.

10. Application of the fractal tree micro-texture chip breaking tool as claimed in any one of claims 1 to 6 in the field of cutting.

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