A method for predicting the cutting performance of a flocked broach

Abstract

The application discloses a kind of cutting performance prediction methods of flocking broach.The method includes the following steps: one, the effective contact length of the tested broach in cutting process is obtained.Two, the transduction coefficient for evaluating the heat dissipation capacity of the tested broach is obtained.Three, the broaching performance of the tested broach is judged.The application considers the various parameters of broach rake face flocking and the factor parameters of lubricating fluid, constructs the temperature field mathematical model of flocking broach, and realizes the accurate evaluation of temperature field in the cutting process of flocking broach through transduction coefficient.The application can accurately obtain the effective contact length and transduction coefficient of flocking broach by constructing two mathematical models, and evaluate the cutting performance of flocking broach and provide corresponding optimization scheme for flocking broach.The broaching tool designed for the size of horizontal broaching machine integrated broach realizes the effects of optimizing and reforming traditional broach, convenient disassembly and assembly and replacing single-tooth broach.

Description

Technical Field

[0001] This invention relates to the field of scientific calculation of cutting performance of cutting tools, and in particular to a method for predicting the cutting performance of a flocking broach. Technical Background

[0002] Currently, many scholars only focus on basic parameters such as cutting force and cutting temperature when modeling the cutting performance of various optimized cutting tools. This approach lacks reliability, considers too few factors, and lacks universality, making it difficult to uncover the sources of new functionalities in optimized tools. Therefore, in existing tool optimization, modeling cutting performance has become a breakthrough point for studying deeper mechanisms. However, tool optimization techniques involving flocking on the tool surface have been rarely discussed, and no scholars have addressed the calculation methods for modeling the cutting performance of flocked broaches. Consequently, the performance modeling and calculation problem of flocked broaches becomes exceptionally difficult under conditions of multi-factor coupling.

[0003] For example, patent application number CN201910183998.6 discloses a method for modeling the temperature field of cryogenic turning tools using liquid nitrogen. This method can obtain the gas-liquid phase ratio of the cryogenic liquid nitrogen cooling fluid, determine the convective heat transfer coefficient, and thus model the temperature field of cryogenic turning tools using liquid nitrogen. However, this invention only satisfies the modeling of the temperature field of cryogenic turning tools using liquid nitrogen, and the environment is quite harsh, greatly limiting its application scope. Another example is patent application number CN202110682769.6, which discloses a method for modeling the cutting force of micro PCD milling tools without side rake angle. This model can predict the cutting force of milling tools under different spindle speeds, feed rates, and radial depths of cut. However, this invention can only effectively calculate the cutting force under different working conditions; the optimization of tools and machining parameters cannot achieve comprehensiveness and breadth, making it difficult to be reliable.

[0004] When evaluating the cutting performance of flocked broaches, the influence of factors such as the area, spacing, length, and density of fibers implanted on the tool's rake face makes it difficult for conventional machining theories to adequately assess their cutting performance. Therefore, modeling the cutting performance of functional cutting tools has consistently perplexed many researchers, making it difficult for conventional manufacturing theories to meet future manufacturing needs, and consequently hindering the tools from achieving their maximum effectiveness in factory use. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by providing a method for predicting the cutting performance of a flocking broach. This method proposes several approaches to model the cutting performance of flocked tools under multi-factor coupling. One approach considers external parameters such as the length, diameter, flocking area, and flocking interval of the broach rake face, as well as the thickness of the lubricant, and combines these with tool parameters such as the rake angle, clearance angle, and cutting load. This establishes a mathematical model to calculate core parameters like the cutter-chip contact length and transduction coefficient of flocked broaches under multi-factor coupling, thereby accurately predicting tool cutting performance. Another approach addresses broaching tools designed for the dimensions of integrated broaches on horizontal broaching machines, enabling the optimization and modification of traditional broaches, and facilitating the disassembly and replacement of single-tooth broaches. A third approach involves embedding fibers into the tool rake face, considering external factors such as the length, diameter, flocking area, and flocking interval of the broach rake face, as well as the thickness of the lubricant, based on a traditional broach model to construct a mathematical model of the cutting performance of flocked broaches. A fourth approach considers flock parameters to construct a mathematical model of the temperature field of flocked broaches. Finally, a fifth approach integrates mathematical models of single-tooth broaches, flocked broach temperature fields, and flocked broach mathematical models.

[0006] A method for predicting the cutting performance of flocked broaches is used to test the broaching performance of flocked broaches. The rake face of the flocked broach is provided with multiple flocking sections arranged sequentially along the cutting edge direction. Each flocking section is flocked with fiber fluff.

[0007] The method for testing the cutting performance of this flocked broach includes the following steps:

[0008] Step 1: Obtain the effective contact length l of the broach under test during the cutting process. c .

[0009] 1-1. Construct the shear stress τ of the broach under test s The expression is as follows:

[0010]

[0011] in, d is the average length of the fiber fibers; d is the diameter of the fiber fibers. τ represents the average spacing between fiber fibers; o, p, and q are three preset power function coefficients, and k is the adsorption coefficient. s0 The shear stress of the broach under test is assuming the front face is not flocked.

[0012] 1-2. Constructing the effective contact length l c The expression is as follows:

[0013]

[0014] Where μ is the coefficient of friction; F Cdenoted as σx, where σx is the normal force applied by the broach during the cutting process; n is the number of flocked sections. i y is the width of the i-th flocked section; i ρ is the distance between the i-th flocking section and the (i+1)-th flocking section; ρ and ε are two correction coefficients, where ρ < ε.

[0015] Step 2: Obtain the transducer ε, which is used to evaluate the heat dissipation capability of the tested broach.

[0016] 2-1. The heat exchange correction coefficient f(u) is constructed as follows:

[0017]

[0018] Where x, y, and z are three preset power function coefficients; β is the correction adhesion coefficient.

[0019] 2-2. The expression for the transduction coefficient ε is constructed as follows:

[0020]

[0021] Where c is the specific heat capacity of the broach under test; Q1 is the heat absorbed by the broach under test in one broaching operation; ΔT is the temperature change of the broach under test before and after one broaching operation; ΔQ is the heat increment of the broach under test in one broaching operation; m2 is the mass of cutting fluid; Q1 is the heat generated by cutting; and m1 is the mass of the broach under test.

[0022] The expression for the mass of cutting fluid m2 is as follows:

[0023]

[0024] Where ρ is the density of the cutting fluid; L is the length of the fluid per unit time; v0 is the diffusion velocity of the cutting fluid on the unflocked broach face; λ is the diffusion gain coefficient between the fibers; Q V This represents the cutting fluid flow rate.

[0025] Cutting fluid flow rate Q V The expression is as follows:

[0026] Q V =S·λv0

[0027] Where S is the cross-sectional area.

[0028] Step 3: Determine the broaching performance of the broach being tested.

[0029] If the effective contact length l of the broach under test during the cutting process cIf the value of the transducer is within the range of 0.2mm to 1.8mm and the value of the transducer ε is within the range of 0.5 to 0.95, then the broaching performance of the broach under test meets the requirements. Otherwise, the broaching performance of the broach under test does not meet the requirements.

[0030] Preferably, in step three, if the broaching performance of the broach being tested does not meet the requirements, the size of the fiber pile on the broach being tested and / or the size of each flocking section shall be adjusted.

[0031] If the effective contact length l of the broach under test during the cutting process c If the fiber length is greater than 1.8 mm and the transduction coefficient ε is greater than 0.2 and less than 0.5, then the length of the fiber fluff should be increased by 15% to 25%.

[0032] If the effective contact length l of the broach under test during the cutting process c If the length of the fiber fluff is less than 0.2 mm, or the transduction coefficient ε ≤ 0.2, the length of the fiber fluff will be reduced by 7% to 18%.

[0033] Preferably, in step three, if the effective contact length l of the broach being tested during the cutting process is... c If the fiber length is greater than 1.8 mm and the transduction coefficient ε is greater than 0.2 and less than 0.5, then while increasing the length of the fiber fluff, the width of the flocking section should be reduced by 5% to 15%.

[0034] If the effective contact length l of the broach under test during the cutting process c If the length of the fiber fluff is less than 0.2 mm, or the transduction coefficient ε ≤ 0.2, then while reducing the length of the fiber fluff, the width of the flocking section should be increased by 10% to 20%.

[0035] Preferably, the average length of the fiber fluff and average spacing The average length of the fiber fibers is determined based on the length and spacing of the fibers in a selected area on the broach being tested. The expression is:

[0036]

[0037] Among them, h i is the length of the i-th fiber in the selected region; m is the number of fibers in the selected region.

[0038] Average spacing of fiber fibers The expression is:

[0039]

[0040] Among them, e iThe distance between the i-th fiber and the (i+1)-th fiber within the selected region.

[0041] Preferably, the length of the flocked section is 2mm to 6mm and the width is 0.1mm to 5.26mm; the distance between two adjacent flocked sections is 0.1mm to 5.26mm.

[0042] Preferably, the material of the fibers on the broach being tested is nylon, polyester, carbon fiber, or acrylic.

[0043] Preferably, the fiber fibers are implanted onto the front cutting surface of the broach being tested using electrostatic flocking technology.

[0044] Preferably, the broach being tested is a single-tooth broach.

[0045] Preferably, the broach under test is provided with a cutting edge, a positioning hole, and a flocking section. The rake angle γ of the broach under test is 10° to 15°; the clearance angle α of the broach under test is 5° to 8°. The diameter of the positioning hole is 3.5mm to 4.5mm; the effective length of the cutting edge is 0.2mm to 0.6mm.

[0046] Preferably, a limiting structure is provided on the bottom side of the broach near the cutting edge. The limiting structure is in the shape of a concave wedge.

[0047] The beneficial effects of this invention are as follows:

[0048] 1. This invention considers various parameters of the flocking on the rake face of the broach and the factors of the lubricant to construct a mathematical model of the temperature field of the flocked broach. Through the transduction coefficient, it realizes the accurate evaluation of the temperature field during the cutting process of the flocked broach.

[0049] 2. This invention constructs a cutting performance model for flocked broaches by coupling multiple factors, obtains tool-chip contact length parameters based on this model, and optimizes the tool and improves its performance during flocked broach machining based on these parameters.

[0050] 3. By constructing two mathematical models, this invention can accurately obtain the effective contact length and transduction coefficient of the flocked broach, and evaluate the cutting performance of the flocked broach accordingly, and provide corresponding optimization solutions for the flocked broach.

[0051] 4. The broaching tool designed for the dimensions of an integrated broaching tool for a horizontal broaching machine achieves the effects of optimizing and transforming traditional broaches, facilitating easy disassembly and assembly, and replacing single-tooth broaches.

[0052] Explanation of the attached diagram

[0053] Figure 1 This is a schematic diagram of the broach being tested in this invention;

[0054] Figure 2 This is a side view of the broach being tested in this invention;

[0055] Figure 3 This is a partial top view of the broach being tested in this invention;

[0056] Figure 4 This is a diagram illustrating the cutting mechanism of the broach tested in this invention. Detailed Implementation

[0057] The present invention will be further described below with reference to the accompanying drawings.

[0058] A method for predicting the cutting performance of a flocked broach is used to obtain the shear force F of the broach 1 under test during the cutting process. s The coefficient of friction, u, is used to accurately evaluate and predict the cutting performance of the broach, providing theoretical guidance for correcting and optimizing the relevant geometric parameters of the broach. The broach 1 under test is specifically a single-tooth broach with fiber fibers implanted on the rake face of the tooth.

[0059] like Figure 1-3 As shown, the broach 1 under test is provided with a cutting edge 1-1, a positioning hole 1-2, a flocked area 1-3, and a limiting structure 1-4. The rake angle γ of the broach 1 under test is 10° to 15°, preferably 12°; the clearance angle α of the broach 1 under test is 5° to 8°, preferably 7°. The diameter of the positioning hole 1-2 is 3.5mm to 4.5mm, preferably 4mm; the effective length of the cutting edge 1-1 is 0.2mm to 0.6mm, preferably 0.25mm.

[0060] like Figure 1 and Figure 3 As shown, the limiting structure 1-4 is located on the bottom side of the broach 1 under test, near the cutting edge, and is in the shape of a concave wedge. This facilitates the installation of the broach 1 under test on the shank of a traditional one-piece broach and shares some of the broaching force. The flocking area 1-3 is located on the front cutting face of the broach 1 under test, including two flocking sections located on both sides of the positioning hole 1-2. Both flocking sections are flocked with fiber fibers. The material of the fiber fibers is nylon, polyester, carbon fiber, or acrylic, preferably carbon fiber. The fiber fibers are implanted into a preset range on the front cutting face of the broach under test using electrostatic flocking technology. The length x2 of the two flocking sections is 6mm, the width y2 is 1mm-15.8mm, and the distance z2 between the two flocking sections is 5mm.

[0061] The method for testing the cutting performance of this flocked broach includes the following steps:

[0062] Step 1, such as Figure 4As shown, by establishing a mathematical model of the cutting performance of flocked broaches, we can better understand the changes in broach loads during broaching, such as the friction coefficient and shear force, and thus more accurately assess the tool's service life. Therefore, a mathematical model of flocked broaches was established based on the traditional mathematical model. However, during the machining process, the cutting force F... C and positive pressure F t This can be collected using a three-dimensional force gauge. Therefore, other forces can be compared with the cutting force F. C and positive pressure F t By relating them, we obtain equation (1):

[0063]

[0064] Among them, F z For positive pressure F t and cutting force F C The resultant force; β is the friction angle of the tool-chip contact surface; γ is the rake angle of the tool.

[0065] Step 2: Because the chip moves at a constant speed when the cutting state is stable, the resultant force (F) between the tool and the workpiece... z The resultant force (F) at the tool-chip interface R These are a pair of balanced forces. According to the principle of force, we can obtain F... R as follows:

[0066] F R =F z Equation (2)

[0067] Step 3: Relate the forces at the tool-chip interface to the forces between the tool and the workpiece. This will give you the normal force F between the rake face and the chip. n as follows:

[0068] F n =F R cosβ (3)

[0069] Step 4: Apply frictional force F f It is the product of the chip shear stress and the shear surface area, that is:

[0070] F f =A s ·τ S Equation (4)

[0071] Among them, F f A is the frictional force between the rake face and the chip. s τ is the contact area of ​​the shear surface. S This is shear stress.

[0072] Step 5: When fiber fluff is added to the front face of the broach, the shearing contact area is affected by the fluff. Therefore, the factor of fiber fluff needs to be taken into account to obtain the contact area A of the shearing surface. s The expression is as follows:

[0073]

[0074] Where, x i y is the width of the flocking section; i The distance between two adjacent flocked sections; ρ and ε are two correction coefficients, ρ < ε; l c is the effective contact length between the chip and the cutting edge, and n is the number of flocked areas.

[0075] Step 6: The effective contact length between the chip and the cutting edge is affected by the chip curling angle and the chip radius, therefore the effective contact length l c for:

[0076] l c =l·θ·R Equation (6)

[0077] Where l is the length of the fluff, θ is the chip curl angle, and R is the chip curl radius.

[0078] Step 7: When adding fluff to the rake face of the broach under test, the shear stress τ s It is also affected by the downy fibers, and its value is as follows (7):

[0079] τ s =ξτ s0 Equation (7)

[0080] Where ξ is the oil film thickness; τ s0 This represents the original shear stress without flocking.

[0081] Step 8: During broaching, lubricants are typically used to improve broaching performance. When broach teeth are fluffed, the lubricant can remain on the broach surface for a longer time, and the oil film thickness ξ is:

[0082] ξ=kh o d p e q Equation (8)

[0083] Where ξ is the oil film thickness; h is the villous length; d is the villous diameter (taken as 8 μm in this embodiment); e is the distance between two adjacent villous strands; o, p, and q are the coefficients of the power function; and k is the adsorption coefficient, which is a material-related coefficient.

[0084] Step 10: The length of the downy hairs is an average value. By selecting a certain area, the length of the downy hairs within the selected area is calculated using image recognition software in MATLAB.

[0085]

[0086] Among them, h i is the length of the selected region; m is the number of fibers within the selected region. The image of the selected region was obtained using a high-speed microscope.

[0087] Step 11: The value of the pile spacing e is an average value, which is calculated by cropping the pile image within a certain area.

[0088]

[0089] Among them, e i The distance between adjacent fibers in the i-th group within the selected area.

[0090] Step 12: Construct the expression for shear stress as follows:

[0091]

[0092] Step 13: The friction coefficient μ is a commonly used evaluation parameter in the processing process, and its expression is:

[0093]

[0094] Step 14: Based on the two-dimensional cutting model of the flocking broach, and combining formulas (1) and (3), we can see that:

[0095]

[0096] Step 15: When orthogonal cutting is used, the rake angle γ of the tool is 0, from which we obtain:

[0097] F n =F c Equation (14)

[0098] Step 16: When a stable oil film exists between the chip and the rake face, the chip slides on the rake face, effectively reducing the coefficient of friction and frictional resistance. Combining equations (5), (11), (12), and (14), the effective contact length l is obtained. c Its expression is:

[0099]

[0100] Step 17: After studying the relationship between fiber fluff and cutting performance, the influence of heat generated during broaching is modeled. Specifically, this starts from the basic equation of temperature change:

[0101] c=Q / (M·ΔT) Equation (16)

[0102] Where c is the specific heat capacity of the material; Q is the heat absorbed; M is the mass of the object; and ΔT is the temperature change after heat absorption.

[0103] Step 18: During broaching, the broaching temperature T at the broach cutting edge increases to a certain extent compared to before broaching, that is:

[0104] T = T0 + ΔT Equation (17)

[0105] Where T0 is the initial temperature of the tool, which is generally considered to be the ambient temperature.

[0106] Step 19: Temperature changes can also be understood as heat changes. Broaching involves both heat generation and heat dissipation; therefore, we can obtain:

[0107] ΔQ=Q1-Q2 Equation (18)

[0108] Where ΔQ is the heat increment of the broach under test during the cutting process; Q1 is the heat generated during cutting; and Q2 is the heat carried away.

[0109] Step 20: During broaching, the heat exchange between the cutting fluid and the broach is affected by the textured coating. Therefore, the concept of a heat exchange correction factor is introduced, and the heat Q2 carried away by the cutting fluid is expressed as:

[0110] Q2=εf(u)cm2ΔT Equation (19)

[0111] Where m2 is the mass of the cutting fluid; f(u) is the heat exchange correction coefficient; and ε is the energy transfer coefficient.

[0112] Step 21: The heat exchange correction coefficient is a variable related to the relevant dimensional parameters of flocking; therefore, the expression is as follows:

[0113]

[0114] Where f(u) is the heat exchange correction coefficient, h is the fiber length, d is the fiber diameter, e is the fiber spacing, x, y and z are preset power function coefficients, and β is the correction adhesion coefficient.

[0115] Step 22: Besides affecting the heat transfer efficiency between the cutting fluid and the broach, the fiber-textured coating also affects the diffusion rate of the cutting fluid on the broach surface, i.e., the mass m2 of cutting fluid flowing through the broach surface per unit time.

[0116] m2=ρV Equation (21)

[0117] Where ρ is the density of the cutting fluid and V is the volume of the cutting fluid.

[0118] Step 23, Cutting fluid flow rate Q V It can be as follows:

[0119] Q V =S·v (22)

[0120] In the formula, S is the cross-sectional area and v is the flow velocity.

[0121] Step 24: From this, we can deduce the relationship between the cutting fluid mass m2 and the cutting fluid flow rate Q. V The relationship between them:

[0122]

[0123] Where L is the length of the liquid per unit time.

[0124] Step 25: Adding fiber fluff to the surface of the broach teeth can increase the diffusion rate of the lubricating fluid on the broach teeth surface. The increased cutting fluid diffusion rate can be:

[0125] v=λv0 Equation (24)

[0126] Where v0 is the initial diffusion velocity of the cutting fluid, and λ is the diffusion gain coefficient between the fiber fibers.

[0127] Step 26: The flow quality of cutting fluid on the broach surface is improved:

[0128]

[0129] Step 27: Using the above heat calculation method, combined with formulas (19), (20), and (25), the heat carried away by the cutting fluid during broaching can be obtained as follows:

[0130]

[0131] Step 28: Since the specific heat capacity m1 of the metallic material can be obtained from existing material properties, and the temperature change ΔT1 after heat release can also be detected by temperature detection equipment such as a thermal imager, the heat generated by the tool during the cutting process can be calculated by combining formula (16), that is:

[0132] Q1=cm1ΔT1 Equation (27)

[0133] Where m1 is the mass of the broach, and ΔT1 is the temperature change after heat release.

[0134] Step 29: Combining formulas (18), (26), and (27), the transduction coefficient ε can be calculated, i.e.:

[0135]

[0136] Step 30: Based on the obtained tool-chip contact length l c The transduction coefficient ε is used to evaluate the tested tool: when cutting high-hardness materials, such as nickel-based alloys, the tool-chip contact length l c The smaller the value, the better; the larger the transduction coefficient ε, the better. This is beneficial for chip curling and reduces the formation of built-up edge, thereby suppressing the coupled vibration of the tool-workpiece-chip system during machining, reducing tool wear, and improving the surface quality of the workpiece. When cutting viscous materials, such as 6062 aluminum alloy, the tool-chip contact length l... c The larger the better, the higher the transduction coefficient ε is, because viscous materials are prone to producing pagoda-shaped chips during the cutting process, and in severe cases, chip entanglement occurs. Therefore, it is necessary to suppress chip curling. In addition, the reduction of heat also helps to improve the working condition of the tool during machining, thereby improving the machining quality of the workpiece.

[0137] The testing criteria for cutting tool performance are as follows:

[0138] 1) When the contact length l between the tool and the chip c When the thickness is greater than 0.8 mm or the transduction coefficient ε is less than 0.2, it indicates that the flocking parameters do not meet the requirements, resulting in excessive cutting load and seriously affecting the cutting performance of the tool.

[0139] 2) When the contact length l between the tool and the chip c When the thickness is less than 0.2 mm or the transduction coefficient is 0.2 < ε < 0.5, it indicates that the area of ​​contact between the chip and the fibrous material is small. At this time, the fibrous material on the surface of the tool cannot play its due role, such as chip storage, vibration damping, lubrication, and cooling.

[0140] 3) When the contact length between the tool and the chip is 0.2mm <l c When the thickness is <0.8mm or the transduction coefficient is 0.5 < ε < 0.95, it indicates that the chip-cutting performance of the flocked broach is relatively stable, which can effectively improve the problems existing in traditional machining and extend the service life of the tool.

[0141] The correction coefficients in the above calculation formula need to be verified by experimental data and actual parameters such as friction coefficient and shear force.

Claims

1. A method for predicting the cutting performance of a flocking broach, characterized in that: The broach under test has multiple flocked sections arranged sequentially along the cutting edge direction on its rake face; each flocked section is covered with fiber fluff; the cutting performance test method for this flocked broach includes the following steps: Step 1: Obtain the effective contact length l of the broach under test during the cutting process. c ; 1-1. Construct the shear stress τ of the broach under test s The expression is as follows: in, d is the average length of the fiber fibers; d is the diameter of the fiber fibers. τ represents the average spacing between fiber fibers; o, p, and q are three preset power function coefficients, and k is the adsorption coefficient; τ s0 The shear stress of the broach under test when the front face is not flocked; 1-2. Constructing the effective contact length l c The expression is as follows: Where μ is the coefficient of friction; F C The normal force applied by the broach during the cutting process; n is the number of flocked sections; x i y is the width of the i-th flocked section; i ρ is the distance between the i-th flocking section and the (i+1)-th flocking section; ρ and ε are two correction coefficients, where ρ < ε; Step 2: Obtain the transducer ε, which is used to evaluate the heat dissipation capability of the broach under test; 2-1. The heat exchange correction coefficient f(u) is constructed as follows: Where x, y, and z are three preset power function coefficients; β is the correction adhesion coefficient; 2-2. The expression for the transduction coefficient ε is constructed as follows: Where c is the specific heat capacity of the broach under test; Q1 is the heat absorbed by the broach under test in one broaching operation; ΔT is the temperature change of the broach under test before and after one broaching operation; ΔQ is the heat increment of the broach under test in one broaching operation; m2 is the mass of cutting fluid; Q1 is the heat generated by cutting; m1 is the mass of the broach under test. The expression for the mass of cutting fluid m2 is as follows: Where ρ is the density of the cutting fluid; L is the length of the fluid per unit time; v0 is the diffusion velocity of the cutting fluid on the unflocked broach face; λ is the diffusion gain coefficient between the fibers; Q V This refers to the cutting fluid flow rate; Cutting fluid flow rate Q V The expression is as follows: Q V =S·λv0 Where S is the cross-sectional area; Step 3: Determine the broaching performance of the broach being tested; If the effective contact length l of the broach under test during the cutting process c If the value of the transducer is within the range of 0.2mm to 1.8mm and the value of the transducer coefficient ε is within the range of 0.5 to 0.95, then the broaching performance of the broach being tested meets the requirements; otherwise, the broaching performance of the broach being tested does not meet the requirements.

2. The method for predicting the cutting performance of a flocking broach according to claim 1, characterized in that: In step three, if the broaching performance of the broach under test does not meet the requirements, the size of the fiber fluff on the broach under test and / or the size of each flocking section shall be adjusted. If the effective contact length l of the broach under test during the cutting process c If the fiber length is greater than 1.8 mm and the transduction coefficient ε is greater than 0.2 and less than 0.5, then the length of the fiber fluff should be increased by 15% to 25%. If the effective contact length l of the broach under test during the cutting process c If the length of the fiber fluff is less than 0.2 mm, or the transduction coefficient ε ≤ 0.2, the length of the fiber fluff will be reduced by 7% to 18%.

3. The method for predicting the cutting performance of a flocking broach according to claim 2, characterized in that: In step three, if the effective contact length l of the broach being tested during the cutting process... c If the fiber length is greater than 1.8 mm and the transduction coefficient ε is greater than 0.2 and less than 0.5, then while increasing the length of the fiber fluff, the width of the flocking section should be reduced by 5% to 15%. If the effective contact length l of the broach under test during the cutting process c If the length of the fiber fluff is less than 0.2 mm, or the transduction coefficient ε ≤ 0.2, then while reducing the length of the fiber fluff, the width of the flocking section should be increased by 10% to 20%.

4. The method for predicting the cutting performance of a flocking broach according to claim 1, characterized in that: Average length of fiber fibers and average spacing The average length of the fiber fibers is determined based on the length and spacing of the fibers in a selected area on the tested broach. The expression is: Among them, h i is the length of the i-th fiber in the selected region; m is the number of fibers in the selected region; Average spacing of fiber fibers The expression is: Among them, e i The distance between the i-th fiber and the (i+1)-th fiber within the selected region.

5. The method for predicting the cutting performance of a flocking broach according to claim 1, characterized in that: The length of each flocked section is 2mm to 6mm, and the width is 0.1mm to 5.26mm; the distance between two adjacent flocked sections is 0.1mm to 5.26mm.

6. The method for predicting the cutting performance of a flocking broach according to claim 1, characterized in that: The fiber fibers on the tested broach were made of nylon, polyester, carbon fiber, or acrylic.

7. The method for predicting the cutting performance of a flocking broach according to claim 1, characterized in that: The fiber fluff is implanted onto the front cutting surface of the broach under test using electrostatic flocking technology.

8. The method for predicting the cutting performance of a flocking broach according to claim 1, characterized in that: The broach being tested is a single-tooth broach.

9. The method for predicting the cutting performance of a flocking broach according to claim 1, characterized in that: The broach (1) under test is provided with a cutting edge (1-1), a positioning hole (1-2), and a flocking section; the rake angle γ of the broach (1) under test is 10° to 15°; the clearance angle α of the broach (1) under test is 5° to 8°; the diameter of the positioning hole (1-2) is 3.5mm to 4.5mm; and the effective length of the cutting edge (1-1) is 0.2mm to 0.6mm.

10. The method for predicting the cutting performance of a flocking broach according to claim 1, characterized in that: A limiting structure (1-4) is provided on the bottom side of the broach (1) near the cutting edge; the limiting structure (1-4) is a concave wedge shape.

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