CN112372372B - Efficient milling cutter accumulated friction wear boundary identification and verification method - Google Patents

Abstract

The invention relates to a high-efficiency milling cutter cumulative friction and wear boundary identification and verification method, which belongs to the technical field of milling cutters, and is aimed at the existing milling experimental method to study the variation of the maximum wear width of the cutter tooth flank with the milling stroke, and cannot reveal the milling vibration and cutter The defects in the formation process of the flank friction and wear boundary of the cutter tooth under the action of tooth error are proposed, which include the measurement and characterization method of the friction and wear boundary of the cutter tooth flank of the high-efficiency milling cutter, the simulation model and boundary conditions of the high-efficiency milling cutter axial layered milling The construction method, the identification method of the instantaneous friction and wear boundary of the tooth flank, the calculation and verification method of the cumulative friction and wear boundary of the tooth flank. The present invention proposes a method for measuring and characterizing the boundary of friction and wear on the flank of a high-efficiency milling cutter, establishes a simulation and identification method for the boundary of instantaneous friction and wear on the flank of a cutter, and proposes a method for calculating the boundary of cumulative friction and wear on the flank of a cutter. The formation process of cumulative friction and wear boundary on flank flank provides an effective model.

Description

A high-efficiency milling cutter cumulative friction and wear boundary identification and verification method

Technical field:

The invention belongs to the technical field of milling cutters, and in particular relates to a method for identifying and verifying the accumulated friction and wear boundary of an efficient milling cutter.

Background technique:

High-efficiency milling cutters are widely used in the machining of large-scale titanium alloy structural parts in the aerospace field due to their efficient cutting performance. During the milling process, affected by milling vibration and cutter tooth errors, the cumulative friction and wear boundary of the flank of milling cutter teeth is limited. There is uncertainty in the formation and evolution, which makes it difficult to accurately evaluate and predict the overall service life of high-efficiency milling cutters, resulting in unstable workpiece processing quality and increased production costs.

Affected by milling vibration and tooth error, the uncertainty of the formation process of the friction and wear boundary of the flank of the milling cutter is the key to predicting the service life of the tool. At present, although there have been researches on the friction and wear of the flank of milling cutter teeth, they mainly focus on revealing the variation characteristics of the friction and wear width of the tooth flank with the milling stroke through milling experiments. However, due to the limitations of the experiment, the instantaneous friction and wear boundary of the flank of the cutter teeth cannot be obtained through the milling experiment, which leads to the inability to pass the milling process. The experimental method revealed the relationship between the instantaneous flank face and the cumulative friction and wear boundary curve and the formation process of the cumulative friction and wear boundary curve.

Invention content:

The invention provides a high-efficiency milling cutter cumulative friction and wear boundary in order to overcome the defect that it is difficult to accurately evaluate and predict the overall service life of the high-efficiency milling cutter in the formation and evolution process of the existing milling cutter tooth flank cumulative friction and wear boundary. Identification and verification method. This method uses the measurement and characterization method of the friction and wear boundary of the flank of the milling cutter tooth, the identification method of the instantaneous friction and wear simulation boundary of the cutter tooth flank, and the calculation of the cumulative friction and wear simulation boundary of the milling cutter tooth flank. method to verify the correctness of the calculation method of the cumulative friction and wear boundary of the flank of the milling cutter.

The technical scheme adopted in the present invention is: a high-efficiency milling cutter cumulative friction and wear boundary identification and verification method, which specifically includes the following steps:

Step A: Propose a method for measuring and characterizing the friction and wear boundary of the flank flank of a high-efficiency milling cutter, construct a boundary measurement coordinate system for the friction and wear of the flank of the milling cutter, and characterize the friction and wear of the flank of the milling cutter in the measurement coordinate system the shape and position of the curve of the boundary;

Step B: Consider the milling method, milling vibration, cutter tooth error and the difference of the surface to be machined in different layers as simulation boundary conditions, and propose a high-efficiency milling cutter axial layer milling simulation model and boundary condition construction method;

Step C: Use the high-efficiency milling cutter axial layered milling simulation model to simulate the thermal coupling field of high-efficiency milling cutter axial layered milling, and extract the instantaneous temperature, equivalent stress, and equivalent strain distribution field of the milling cutter tooth flank, According to the formation process of the instantaneous friction and wear boundary of the flank of the milling cutter tooth, a method for identifying the boundary of the instantaneous friction and wear simulation of the flank of the cutter tooth is proposed.

Step D: According to step C, the instantaneous friction and wear boundary of the flank face of the cutter tooth at different times is obtained, the formation process of the cumulative friction and wear boundary of the flank face of the cutter tooth is analyzed, and the calculation method of the cumulative friction and wear simulation boundary of the flank face of the milling cutter is proposed. The grey correlation degree and average relative error of the cumulative friction and wear boundary curve of the milling cutter tooth flank obtained through simulation and experiment are calculated to verify the correctness of the calculation method of the milling cutter tooth flank cumulative friction and wear boundary.

Preferably, the step A further comprises the following steps:

Step A1: The milling method of the high-efficiency milling cutter under the action of vibration: in the workpiece coordinate system, the cutting state of the milling cutter under the action of the offset and vibration of the milling cutter coordinate system is used to reflect the impact of milling vibration on the cutting process of the high-efficiency milling cutter;

Step A2: According to the structural characteristics of the high-efficiency milling cutter, determine the cutter tooth error of the milling cutter and the measurement method for the friction and wear of the flank;

Step A3: Use the relationship matrix between the workpiece coordinate system, the milling cutter coordinate system, the cutter coordinate system and the flank friction and wear boundary measurement coordinate system under the influence of the milling vibration and the cutter tooth error to reflect the relationship between the milling vibration and the cutter tooth error. The influence of the instantaneous contact relationship between the tooth flank and the workpiece;

Step A4: Construct the upper and lower boundary curves of the friction and wear of the flank of the milling cutter by measuring the end points and inflection points of the friction and wear boundary of the flank of the cutter in turn in the measurement coordinate system of the tooth flank, and determine the flank of the cutter Surface friction and wear boundary.

Preferably, the step B further comprises the following steps:

Step B1: Consider the milling method, cutter tooth error, milling vibration and the difference of the surface to be machined in different layers as simulation boundary conditions, design the overall structure of the high-efficiency milling cutter axial layered milling simulation model, and determine and solve the simulation model design variables;

Step B2: Build a milling unit of simulation model, solve the motion trajectory and instantaneous cutting attitude angle of the milling cutter under the action of vibration, determine the cross-sectional model of the milling unit, and construct the milling unit considering the milling vibration and cutter tooth error;

Step B3: In the simulation process, according to the movement trajectory of the milling cutter under the action of vibration in the axial layered milling experiment, the discrete time interval of the movement trajectory points of the milling cutter is determined, and the movement trajectory points of the milling cutter under the action of vibration in the simulation process are carried out. Solve.

Preferably, described step C, also comprises the following steps:

Step C1: perform thermal coupling field simulation through the high-efficiency milling cutter axial layered milling simulation model, and extract the equivalent stress field, equivalent strain field and temperature field distribution of any instantaneous cutting of the milling cutter tooth flank;

Step C2: Extract the equivalent stress, equivalent strain and temperature values of nodes at different positions on the flank of the milling cutter tooth, and construct the equivalent stress, equivalent strain, and temperature distribution surfaces of the flank of the milling cutter, which are parallel to the flank of the tooth. The normal vector direction of the midpoint of the cutting edge on the projection surface of the cutting edge is taken as the section plane perpendicular to the distribution surface in turn through the nodes on the cutting edge, and the equivalent stress, equivalent strain, temperature of the nodes on the section plane at different positions on the flank of all teeth are constructed. distribution curve;

Step C3: Use a univariate high-order polynomial to fit the equivalent stress, equivalent strain and temperature distribution curves at each section plane of the flank face of the cutter in turn, and obtain the node change rate distribution curve by derivation;

Step C4: Using the yield strength of the tooth material as the criterion, identify the critical feature nodes whose equivalent stress is greater than and closest to yield on all section planes. In the tool tooth flank friction and wear measurement coordinate system, the section planes at different positions The upper feature points together constitute the upper boundary of the instantaneous friction and wear simulation of the tooth flank;

Step C5: Identify the nodes where the temperature, equivalent stress, and equivalent strain rate of change at each section plane of the tooth flank have abrupt changes in turn, take the sudden change node as the feature point, and measure the coordinates on the friction and wear boundary of the tooth flank In the system, the node temperature, equivalent stress, and equivalent strain mutation characteristic curves on the flank of the tooth flank are constructed. Lower boundary of friction and wear simulation.

Preferably, the step D further comprises the following steps:

Step D1: According to the instantaneous friction and wear boundary curve of the flank of the cutter teeth at different milling times, and taking the lower boundary curve of the cumulative friction and wear as an example, a method for calculating the boundary of the cumulative friction and wear of the flank of the milling cutter tooth is proposed;

Step D2: Design the simulation and experimental comparison scheme of the upper and lower boundary of the cumulative friction and wear of the flank of the cutter tooth, and use the calculation method of the boundary curve of the cumulative friction and wear of the cutter tooth flank to construct the upper and lower simulation of the cumulative friction and wear of the milling cutter tooth flank. Boundary curve, compare the upper and lower boundary curves of experimental friction and wear with the upper and lower boundary curves of simulation;

Step D3: Calculate the grey correlation value and the average relative error between the simulation and the experimental cumulative friction and wear boundary curve, analyze the shape similarity and position coincidence between the simulation and the experimental cumulative friction and wear boundary curve, and verify the cumulative friction and wear boundary solution correctness of the method.

The beneficial effects of the present invention are:

1. The present invention fully considers the characteristic information of the entire wear boundary of the flank face of the milling cutter, by establishing a coordinate system for measuring the friction and wear boundary of the flank of the cutter tooth, and taking the endpoints and inflection points on the left and right sides of the friction and wear boundary as feature points, Constructing the upper and lower boundary characteristic point curves of the friction and wear of the flank face of the milling cutter can more completely characterize the shape and position information of the boundary curve of the friction and wear of the flank of the cutter tooth. , the relationship matrix between the cutter coordinate system, the cutter tooth coordinate system, and the flank friction and wear boundary measurement coordinate system, which is beneficial to reveal the cutter-worker contact relationship and the formation process of the friction and wear boundary during the milling process.

2. The present invention fully considers the influence of milling method, milling vibration, cutter tooth error, and the difference of surfaces to be machined in different layers on the structure of the simulation model, and considers the milling method, milling vibration, cutter tooth error and surfaces to be machined in different layers as By simulating the boundary conditions, a new simulation model design method for high-efficiency milling cutter axial layered milling is proposed. The simulation model designed by this method is used to simulate the thermal coupling field of high-efficiency milling cutter axial layered milling, and the simulation results are more accurate.

3. Based on the simulation boundary formation process of the instantaneous friction and wear of the flank of the milling cutter, the present invention proposes a flank of the milling cutter according to the instantaneous cutting node temperature field, equivalent stress and equivalent strain distribution characteristics of the flank of the milling cutter. The upper and lower boundary identification method of instantaneous friction and wear simulation of face, and the calculation method of cumulative friction and wear simulation boundary of milling cutter tooth flank, revealing the formation process of milling cutter tooth flank cumulative friction and wear boundary, and putting forward the milling cutter tooth flank Verification method of surface cumulative friction and wear boundary solution method.

Description of drawings:

Fig. 1 is a flow chart of a method for calculating the boundary of cumulative friction and wear on the flank of a high-efficiency milling cutter;

Figure 2 is a state diagram of high-efficiency milling cutter milling under the action of vibration;

Fig. 3 is the state diagram of the instantaneous cutting of the milling cutter under the action of vibration;

Fig. 4 is a high-efficiency milling cutter structure and a cutter tooth error measurement method, wherein Fig. 4(a) is a schematic diagram of the overall structure of a high-efficiency milling cutter, and Fig. 4(b) is a schematic diagram of the milling cutter cutter tooth structure;

Figure 5 is a schematic diagram of the method for measuring the friction and wear boundary of the tooth flank and characterizing the wear depth, in which Figure 5(a) is the measurement method of the friction and wear boundary of the tooth flank, and Figure 5(b) is the wear depth of the tooth flank. ;

Figure 6 is a graph of the upper and lower boundaries of friction and wear of the flank of the milling cutter tooth;

Fig. 7 is a schematic diagram of the vibration acceleration time domain signal of the fourth layer of effective milling in layered milling;

Figure 8 is a diagram of the wear state of the flank of the bottom edge of a high-efficiency milling cutter with a milling stroke of 5m, in which Figure 8(a) is a diagram of the wear state of the first tooth flank, and Figure 8(b) is the second tooth flank. The wear state diagram, Figure 8(c) is the wear state diagram of the third flank of the cutter teeth;

Figure 9 is the distribution curve of the upper and lower boundary feature points of the friction and wear of the flank of the high-efficiency milling cutter tooth, of which Figure 9(a) is the distribution curve of the upper boundary characteristic points of the friction and wear of the flank of the milling cutter tooth, and Figure 9(b) is the distribution curve of the lower boundary feature points of the friction and wear of the flank of the milling cutter tooth;

Figure 10 shows the overall structure of the high-efficiency milling cutter axial layered milling simulation workpiece overall structure and unit cross-sectional model diagram, in which Figure 10(a) is the overall structure of the high-efficiency milling cutter axial layered milling simulation workpiece model, and Figure 10(b) is the first part. Model diagram of the cross-sectional model of the milling unit at layer i (i≥2);

Fig. 11 is the identification diagram of the cutting in and out of the i-th (i≥2) layer of the milling cutter;

Figure 12 is a schematic diagram of the trajectory of the milling cutter movement under the action of vibration;

Fig. 13 is the signal diagram of the instantaneous cutting attitude angle of the i-th layer milling cutter, wherein Fig. 13(a) is the deflection angle of the milling cutter along the feeding direction, and Fig. 13(b) is the deflection angle of the milling cutter along the cutting width direction;

Fig. 14 is a solid view of the formation of the i-th layer milling unit, wherein Fig. 14(a) is a schematic surface view of the i-th layer milling unit, Fig. 14(b) is a cross-sectional view at A-A in Fig. 14(a), Fig. 14 ( c) is a sectional view at B-B in Figure 14(a);

Figure 15 is the simulation diagram of the high-efficiency milling cutter axial layered milling process, in which Figure 15(a) is the simulation diagram of the milling cutter cutting stage, Figure 15(b) is the simulation diagram of the middle cutting section of the milling cutter, and Figure 15(c) is the milling cutter Cut-out stage simulation diagram;

Figure 16 is the distribution diagram of instantaneous equivalent stress, equivalent strain field and temperature field on the flank of the milling cutter tooth, in which Figure 16(a) is the equivalent stress distribution diagram, and Figure 16(b) is the equivalent strain field distribution diagram , Figure 16(c) is the temperature field distribution map;

Figure 17 is a section plane parallel to the normal vector direction of the midpoint of the cutting edge of the tooth and perpendicular to the equivalent stress, equivalent strain and temperature distribution surface of the tooth flank at equal intervals, of which Figure 17(a1) is the tooth flank surface Equivalent stress distribution diagram, Fig. 17(a2) is parallel to the cutting edge normal vector direction on the projection surface of the flank face of the cutter, and the upper node of the cutting edge is in turn taken as a cross-sectional plane perpendicular to the surface of Fig. 17(a1), Fig. 17 (b1) The equivalent strain distribution diagram of the tooth flank, Figure 17 (b2) is parallel to the projection plane of the tooth flank and the normal vector direction of the midpoint of the cutting edge is equally spaced through the upper node of the cutting edge. (b1) The section plane of the curved surface, Fig. 17(c1) is the temperature distribution of the tooth flank, and Fig. 17(c2) is the normal vector direction of the midpoint of the cutting edge parallel to the projection of the tooth flank over the upper node of the cutting edge Make a section plane perpendicular to the curved surface of Figure 17(c1) in turn;

Figure 18 is a graph of the equivalent stress distribution of nodes at different positions on the flank of the cutter teeth, of which Figure 18(a) is a graph of the stress distribution of nodes at section A, and Figure 18(b) is a graph of the stress distribution of nodes at section B. Figure 18(c) is a graph showing the stress distribution curve of the node at section C;

Figure 19 is a graph of the equivalent strain and temperature distribution at the node of the tooth flank section B, in which Figure 19(a) is the equivalent strain distribution curve at the section B, and Figure 19(b) is the temperature distribution curve at the section B. picture;

Figure 20 is the distribution curve diagram of equivalent stress, equivalent strain and temperature change rate at the section B of the flank face of the cutter tooth, in which Figure 20(a) is the distribution curve diagram of the equivalent stress change rate, and Figure 20(b) is the equivalent effect Change rate distribution curve, Figure 20(c) is the temperature change rate distribution curve;

Figure 21 is the upper boundary curve graph of the instantaneous friction and wear simulation of the flank of the milling cutter tooth;

Fig. 22 is a graph showing the lower boundary identification curve of the instantaneous friction and wear simulation of the flank of the milling cutter tooth;

Figure 23 is a graph showing the evolution process of the cumulative friction and wear boundary formation on the flank of the milling cutter tooth;

Figure 24 is the upper and lower boundary curves of the instantaneous friction and wear between the cutter tooth and the flank of the milling cutter, in which Figure 24(a) is the upper boundary curve of the instantaneous friction and wear of the cutter tooth flank, and Figure 24(b) is the cutter tooth flank surface. The lower boundary curve of instantaneous friction and wear;

Fig. 25 is a graph comparing the upper and lower boundary curves of cumulative friction and wear of milling cutter teeth-simulation and experiment.

Detailed ways:

As shown in Figure 1, a high-efficiency milling cutter cumulative friction and wear boundary identification and verification method of the present invention is to utilize the workpiece coordinate system, milling cutter coordinate system, cutter tooth coordinate system and flank under the influence of milling vibration and cutter tooth error. The relationship matrix between the friction and wear boundary measurement coordinate systems reflects the influence of milling vibration and cutter tooth error on the instantaneous contact relationship between the cutter tooth flank and the workpiece, and establishes the cutter tooth flank friction and wear boundary measurement coordinate system. The endpoints and inflection points on the upper left and right sides are the characteristic points, and a method for measuring and characterizing the friction and wear boundary of the flank of the milling cutter tooth is proposed, and the shape and position of the friction and wear boundary curve of the flank face of the milling cutter tooth are completely characterized in the measurement coordinate system. ; Considering the milling vibration, cutter tooth error, milling method, and the difference of the surface to be machined in different layers as simulation boundary conditions, a simulation model and boundary condition construction method for high-efficiency milling cutter axial layered milling are proposed; based on the instantaneous friction of the cutter tooth flank The formation process of the wear boundary and the instantaneous node temperature field, equivalent stress and equivalent strain distribution characteristics of the flank of the cutter tooth, and the simulation criteria of the upper and lower boundaries of the instantaneous friction and wear of the flank of the milling cutter are proposed. Based on the simulation criterion of instantaneous friction and wear, A method for calculating the cumulative friction and wear boundary of the flank of milling cutter teeth is proposed. By calculating the gray correlation value and the average relative error between the simulation and experimental cumulative friction and wear boundary curves, the shape between the simulation and experimental cumulative friction and wear boundary curves is analyzed. The degree of similarity with the position verifies the correctness of the calculation method of the cumulative friction and wear boundary on the flank of the milling cutter tooth.

The method for identifying and verifying the cumulative friction and wear boundary of a high-efficiency milling cutter specifically includes the following steps:

Step A: Measurement and characterization method of friction and wear boundary of high-efficiency milling cutter tooth flank

Step A1 Milling method of high-efficiency milling cutter under the action of vibration

In the workpiece coordinate system, the influence of milling vibration on the cutting process of the high-efficiency milling cutter is reflected by the offset of the milling cutter coordinate system and the cutting state of the milling cutter under the action, as shown in Figure 2 and Figure 3, the variable parameters in Figure 2 and Figure 3 The explanation is shown in Table 1-1.

Table 1-1 High-efficiency milling cutter milling mode and instantaneous cutting state variable explanation under the action of vibration

Step A2 Milling cutter tooth error and flank friction and wear measurement

In order to study the influence characteristics of the cutter tooth error on the friction and wear boundary of the cutter tooth flank, in the milling cutter coordinate system, the maximum outer radius of the cutter tooth is used as the benchmark to measure the cutter tooth radial error. The lowest point is the benchmark to measure the axial error of the cutter teeth. As shown in Figure 4, the explanation of the variable parameters in Figure 4 is shown in Table 1-2.

Table 1-2 The structure of the advanced milling cutter and the variable explanation of the measurement method of the cutter tooth error

Make the installation reference plane of the cutter tooth perpendicular to the measuring horizontal plane, and on the projection of the flank face of the cutter tooth on the measuring horizontal plane, take the normal vector of the outer tip of the cutter tooth parallel to the midpoint of the cutting edge and the normal vector along the midpoint of the cutting edge. The reverse intersection point O _j of the tangent vector is the origin, and the measurement coordinate system O _j -UVS of the friction and wear boundary of the flank face of the milling cutter tooth is established. In the direction of the normal vector of the midpoint of the cutting edge on the projection plane, the axis S is perpendicular to the measurement horizontal plane. And measure the upper and lower boundaries of the friction and wear of the flank on the parallel plane of the measurement coordinate system parallel to the tangent plane of the midpoint of the cutting edge of the cutter teeth, as shown in Figure 5(a). Figure 5(b) shows the characterization method of the friction and wear depth on the flank of the cutter teeth.

The interpretation of the variable parameters in Figure 5 is shown in Table 1-3.

Table 1-3 Explanation of variables for measuring the boundary of friction and wear on the flank of the cutter tooth

Step A3 Influence of milling vibration and cutter tooth error on the instantaneous contact relationship between cutter tooth flank and workpiece

Using the relationship matrix between the workpiece coordinate system, the milling cutter coordinate system, the cutter coordinate system and the flank friction and wear measurement coordinate system under the influence of milling vibration and cutter tooth error, it reflects the impact of milling vibration and cutter tooth error on the cutter tooth flank. The influence of the instantaneous contact relationship between the surface and the workpiece. The relationship matrix between the milling cutter coordinate system and the workpiece coordinate system under the action of no vibration is shown in formula (1-1), and the relationship matrix between the milling cutter coordinate system under the action of vibration and no vibration is shown in formula (1-3) The relationship matrix between the cutter tooth coordinate system and the milling cutter coordinate system is shown in formula (1-5), and the relationship matrix between the cutter tooth coordinate system and the flank friction and wear measurement coordinate system is shown in formula (1-7) ).

[x _g y _g z _g 1] ^T =M ₁ [abc 1] ^T (1-1)

[abc 1] ^T = M ₂ T ₁ [a _v b _v c _v 1] ^T (1-3)

[abc 1] ^T = M ₃ T ₂ [a _q b _q c _q 1] ^T (1-5)

[a _q b _q c _q 1] ^T = M ₄ T ₄ T ₃ [UVS 1] ^T (1-7)

为刀齿定位面与铣刀刀槽安装面之间的夹角，

为π/2。Among them, M ₁ , M ₂ , M ₃ , and M ₄ are translation matrices; T ₁ , T ₂ , T ₃ , and T ₄ are rotation matrices; in M ₁ , x(t), y(t), and z(t) is the position of the milling cutter center in workpiece coordinates at time t, in T ₄ ,

is the angle between the positioning surface of the cutter teeth and the mounting surface of the milling cutter groove,

is π/2.

Step A4 Determination of the friction and wear boundary of the tooth flank

In order to fully characterize the shape and position information of the upper and lower boundaries of the friction and wear of the milling cutter tooth flank, the projection of the milling cutter tooth flank on the wear boundary measurement coordinate system O _j -UV plane measured under a super-depth microscope The end points and inflection points on the left and right sides of the upper and lower boundaries of the friction and wear of the flank flank of the cutter teeth and the inflection points are sequentially identified along the cutting edge direction, and the coordinates of the endpoints and the inflection points along the V-axis are measured in turn in the measurement coordinate system of the flank flank wear boundary of the cutter teeth. value, and the upper and lower boundary curves of friction and wear on the flank of the milling cutter tooth are constructed with the endpoints and inflection points on the left and right sides as feature points. As shown in Figure 6, where V=V ₀ (U) is the original cutting edge profile curve of the flank face of the milling cutter tooth V=V _rq (U, L) (1≤q≤3) is the milling stroke L The upper boundary characteristic point curve of the friction and wear of the flank face of the milling cutter tooth q, V=V _hq (U, L) is the lower boundary characteristic point curve of the friction and wear of the milling cutter tooth q of the flank face with the milling stroke L.

The implementation steps of the method are as follows. An experiment of high-efficiency milling cutter axial layer milling of titanium alloy is carried out, and the friction and wear results of the flank face of the high-efficiency milling cutter are obtained. The milling scheme is shown in Table 1-4.

Table 1-4 Experimental scheme for milling titanium alloy with high-efficiency milling cutter

In Table 1-4, L is the total effective milling stroke of 5m, Δc _zi is the axial error of cutter ⁱ , and Δc _ji is the radial error of cutter ⁱ . The axial and radial errors of each cutter tooth of the milling cutter are calculated based on the lowest point of the milling cutter tooth and the maximum radius of the milling cutter tooth tip point.

After the tool tooth error measurement is completed, the titanium alloy milling experiment is carried out on the three-axis milling machining center. The length, width and height of the workpiece are 250 × 100 × 10 mm. The acceleration sensor detects the vibration signal generated by the cutting force at the workpiece surface close to the cutting area, and uses the DH5922 transient signal test and analysis system to analyze the collected vibration signal. As shown in Figure 7.

After the experiment, the super-depth-of-field microscope was used to detect the friction and wear boundary of each tooth flank of the milling cutter in turn, as shown in Figure 8.

The upper and lower boundary curve feature points identification method of friction and wear is used to extract the characteristic points of the upper and lower boundary curves of wear and wear on the flank of the milling cutter tooth in Figure 8 in turn, as shown in Figure 9.

It can be seen from Figure 9 that this measurement method can completely characterize the shape and position of the upper and lower boundaries of the flank wear of the milling cutter teeth; affected by the cutter tooth error and milling vibration, the upper and lower boundary distributions of the flank wear of different teeth of the milling cutter show obvious differences.

Step B: High-efficiency milling cutter axial layer milling simulation model and boundary condition construction method

Step B1 Overall structure design of high-efficiency milling cutter axial layered milling simulation model

Considering the milling method, cutter tooth error, milling vibration and the difference of the surface to be machined in different layers as simulation boundary conditions, design the overall structure of the simulation model of high-efficiency milling cutter axial layered milling, and determine and solve the design variables of the simulation model, as shown in Figure 10 shown.

In Figure 10(a), the simulated workpiece is composed of several milling units. Each layer of milling units corresponds to a workpiece shape in an axial layered milling process. The milling units have a rectangular groove structure, and different layers are to be processed. The surface profiles are different but at the same level, _Li ⁽ⁱ⁺¹⁾ is the distance between the i-1th layer milling unit and the i-th layer milling unit, and H' is the height of the rectangular groove.

In Figure 10(b), O _i is the center of the circle where the cutting edge of the milling cutter tooth bottom edge is located, r ₀ is the radius of the circle where the milling cutter tooth cutting edge is located, and d _m is the milling cutter axis C ₁ C ₂ along the cutting width direction to The distance between the workpieces, J _d is the lowest point on the cutting edge of the milling cutter tooth that participates in cutting, J _h is the highest contact point between the side edge of the cutter tooth and the surface to be machined, Δr _z ^max and Δr _j ^max are the milling cutter teeth, respectively Maximum axial and radial errors; H _i represents the height of the i-th (i≥2) layer of milling units, where the cross-section of the first layer of milling units is the same as the initial cross-sectional dimension of the workpiece.

The control parameters of the simulated workpiece are: L _i ⁽ⁱ⁺¹⁾ , H', L _i-1 ⁱ , H _i , W, L ₀ , d _m , a _p , Δr _z ^max , Δr _j ^max , r ₀ , r, a, _Jd , _Jh . The solution method of L _i ⁽ⁱ⁺¹⁾ is as follows:

Among them, T _i ⁱ⁺¹ is the time from P _3i to P _2(i+1) of the milling cutter in the actual machining process.

H _i =H+(i-1)a _p (i≥2) (2-3)

Step B2 Simulation Model Milling Unit Construction

(1) According to Fig. 2 and Fig. 3 in step A, solve the instantaneous deflection angles δ ₁ (t) and δ ₂ (t) of the milling cutter along the feed speed direction and the cutting width direction at time t during the milling process, as shown in the formula (2-4), (2-5).

Solve the trajectory equation f ^v = (x _gv , y _gv , z _gv , t) of the milling cutter center point in the workpiece coordinate system under the action of vibration, as shown in formula (2-6).

In formula (2-6), A _x (t), A _y (t), and A _z (t) are obtained by quadratic integration of the vibration acceleration signal measured during the experiment, and then using the 8th Sun of Matlab obtained by fitting the sin Function function. t _e is the time it takes for the milling cutter to move from P _4i to P _1(i+1) , as shown in formula (2-7), T _i is the milling cutter moving from P _1(i+1) to P _{1(i+ 1)} , as shown in formula (2-8).

T _i =[T _si ,T _ei ]=[(i-1)(T _c +t _e ),iT _c +(i-1)t _e ] (2-8)

Among them, T _si is the starting point of the tool path of the i-th feed of the milling cutter along the x _g -axis direction, T _ei is the tool-lifting time of the i-th feed of the milling cutter along the x _g -axis direction; T _c milling cutter starts from P _1i The time it takes to move to P _4i is shown in formula (2-9).

(2) Identify the cut-in and cut-out time in the milling vibration signal of the i-th layer (i≥2), as shown in Figure 11, and solve the milling cutter motion trajectory equation of the cutting section T _m of the i-th layer according to equation (2-6). f ^v = (x _gv , y _gv , z _gv , t), as shown in FIG. 12 .

(3) According to equations (2-4) and (2-5), use matlab to solve the instantaneous cutting attitude angle of the i-layer milling cutter, and the results are shown in Figure 13.

(4) As shown in Figure 14, according to the cross-sectional model of the milling unit in Figure 10(b), the cross-section of the i-th layer of milling unit is constructed, and the NJ _h segment is swept along the milling cutter trajectory curve to form the surface to be machined by the milling unit, In the sweeping process, the instantaneous cutting attitude angle of the i-th layer milling cutter is introduced, and finally other surfaces of the milling unit are constructed in turn to form entities. The parameter explanations of the variables in Figure 14 are shown in Table 2-1.

Table 2-1 Calculation of variables for the i-th layer milling and milling unit

Step B3 Simulation motion trajectory calculation of high-efficiency milling cutter axial layered milling under the action of vibration

In the simulation process, in order to introduce the vibration displacement of the milling cutter during the milling process, according to the movement trajectory of the milling cutter under the action of vibration in the axial layered milling experiment, and based on the premise of not changing the feed rate, the discrete points of the movement trajectory of the milling cutter are determined. The time interval is used to calculate the movement trajectory points of the milling cutter under the action of vibration during the simulation process. The steps are as follows:

(1) Determine the discrete time interval of the trajectory points. In order to make the simulation results more accurate, 1/3 of the minimum unit size L _min of the minimum grid unit of the workpiece is used as the simulation step, and t _d is as formula (2-10).

(2) Recalculate the coordinate values from the cut-in to the cut-out at any i-th layer (i≥2) of the milling cutter, as shown in formula (2-11).

(3) Fill up the coordinates of the milling cutter trajectory point between the cut-out point of any i-th layer and the cut-in point of the i+1-th layer, and solve the time steps between the cut-out point of the i-th layer and the cut-in point of the i+1-th layer as follows: Formula (2-12), the step distance of adjacent trajectory points between the cut-out point of the i-th layer and the cut-in point of the i+1-th layer is as shown in formula (2-13), and the coordinate solution method between the adjacent two-layer track points is as formula (2-14).

Step C: Recognition method of instantaneous friction and wear boundary of tooth flank

Step C1 High-efficiency milling cutter axial layer milling thermal coupling field simulation

In order to obtain the simulation boundary of instantaneous friction and wear on the flank of the milling cutter tooth, using the milling experimental parameters in step A, according to the high-efficiency milling cutter axial layered milling simulation model designed in step B, the thermal coupling field simulation was carried out. The Johnson-Cook constitutive model is shown in formula (3-1), and the simulated milling processing parameters use the high-efficiency milling cutter milling titanium alloy experimental processing parameters in Table 1-4.

—材料等效应变，等效应变率/s^-1,参考应变率取值1s^-1；其中，高效铣刀基体材料为硬质合金WC,刀具涂层材料为TiN，厚度为5μm，屈服强度σ_s为5.9GPa,TC4钛合金材料J-C本构参数如表3-1所示。铣削仿真过程如图15所示。In the formula: σ—equivalent flow stress; A, B, n, c, m—yield stress intensity, strain hardening constant, strain hardening index, strain rate hardening parameter, temperature strain rate sensitivity; T, T _r , T _m — Real-time temperature, room temperature, value 25℃, material melting temperature/℃; ε,

—Material equivalent strain, equivalent strain rate/s ^-1 , the reference strain rate is 1s ^-1 ; among them, the base material of the high-efficiency milling cutter is cemented carbide WC, the tool coating material is TiN, the thickness is 5 μm, and the yield strength σ _s is 5.9GPa, and the JC constitutive parameters of TC4 titanium alloy material are shown in Table 3-1. The milling simulation process is shown in Figure 15.

Table 3-1 TC4 titanium alloy J-C constitutive parameter table

After the simulation, the equivalent stress field, equivalent strain field and temperature field of any instantaneous cutting on the flank of the milling cutter tooth are extracted, as shown in Figure 16.

Step C2 Instantaneous node equivalent stress, equivalent strain and temperature change curve at different positions on the flank of the tooth

Extract the equivalent stress, equivalent strain and temperature values of nodes at different positions on the flank of the milling cutter, and construct the equivalent stress, equivalent strain, and temperature distribution surfaces of the flank, which are parallel to the projection surface of the flank. The normal vector direction of the midpoint of the upper cutting edge passes through the upper node of the cutting edge to make several section planes perpendicular to the distribution surface in turn, as shown in Figure 17, to construct the equivalent stress distribution curves of the nodes on the section plane at different positions of the flank face, and identify them. The equivalent stress on the section plane is greater than and closest to the critical node of the yield strength σ _s , as shown in Figure 18, the equivalent strain and temperature distribution curves of the section plane on the section plane at different positions of the flank are constructed, taking section plane B as an example , as shown in Figure 19.

Step C3 Curves of stress, strain and temperature change rate at different positions on the flank of the tooth

In the cutting process of high-efficiency milling cutters, there is shear and friction between the flank of the cutter teeth and the transition surface of the workpiece, so that the stress concentration is formed inside the cutter teeth in the contact area and spreads to the non-contact area. At the boundary node, the stress value drops sharply; at the same time, the heat generated in the process of shear friction causes the temperature of the contact surface of the tooth flank to rise sharply, and the generated heat is transferred to the non-contact area at the flank of the tooth, and the contact At the non-contact boundary node, the temperature value drops sharply, resulting in a very large temperature gradient on the flank of the tooth; during the milling process, the interaction between the flank of the tooth and the transition surface of the workpiece produces extrusion deformation, making the Strain concentration occurs at the contact boundary node between the tooth flank and the transition surface of the workpiece, and a small strain occurs at the non-contact boundary; Therefore, the node temperature, equivalent stress, and equivalent strain distribution curves at each section are fitted sequentially by a high-order polynomial of one variable, and the derivation is obtained by using formula (3-2), formula (3-3), and formula (3-4). The node change rate distribution curve, taking section B as an example, identifies the node inflection points where the change rate of temperature, stress and strain changes abruptly at each section position of the flank face, as shown in Figure 20.

Step C4 Recognition of upper boundary of instantaneous friction and wear simulation of tooth flank

Based on the mechanical properties of the material, when the equivalent stress on the cutting edge of the tooth is greater than the yield strength, the material on the cutting edge will peel off and be taken away by the chips, resulting in the change of the blade shape and the upper boundary of instantaneous friction and wear on the flank of the tooth. Based on the above analysis, the yield strength σ _s of the cutter tooth material is used as the upper boundary of the instantaneous friction and wear simulation of the cutter tooth flank to identify and judge the drama. And the critical feature node closest to the yield strength, in the flank friction and wear measurement coordinate system, the boundary surrounded by the feature nodes on the section plane is the upper boundary of the instantaneous friction and wear of the tooth flank, as shown in Figure 21.

σ≥σ _s (3-5)

Step C5 Identification of the lower boundary of the instantaneous friction and wear simulation of the flank of the cutter tooth

During the instantaneous cutting process, the flank of the milling cutter tooth and the transition surface of the workpiece are sheared, squeezed and rubbed to form the lower boundary of instantaneous friction and wear of the flank of the milling cutter tooth, and the flank of the cutter tooth is in contact with the transition surface of the workpiece. There will be obvious differences in temperature, equivalent stress, and equivalent strain between the non-contact area and the non-contact area. Based on the above analysis, a method for identifying the lower boundary of the instantaneous friction and wear simulation of the flank of the milling cutter tooth flank is proposed. The above method is used to identify the cutter in turn. The nodes where the temperature, equivalent stress, and equivalent strain of each section plane of the tooth flank have abrupt changes are shown in Figure 22. The calculation method of the lower boundary curve of the instantaneous friction and wear simulation of the flank flank is shown in equations (3-6) and (3-7).

V _m (U _i ,t)=max{V _T (U _i ,t),V _σ (U _i ,t),V _ε (U _i ,t)}(0≤i≤10.7) (3-6)

V _m (U,t)={V _m (U ₁ ,t),V _m (U ₂ ,t)...V _m (U _i ,t)} (3-7)

As shown in Figure 22, V=V ₀ (U) is the original contour boundary of the milling cutter, V=V _T (U, t), V=V _σ (U, t), V _ε (U, t) are the time t respectively Temperature, stress, strain sudden change node curve of milling cutter tooth flank, in formula (3-6), V _T (U _i ,t), V _σ (U _i ,t), V _ε (U _i ,t) are the V-coordinate values of the tooth flank temperature, stress and strain mutation node curve U _i at time t, respectively. In Equation (3-7), V _m (U _i ,t) is the coordinate value in the V direction at the lower boundary curve U _i of the instantaneous friction and wear of the milling cutter tooth flank at time t, and V _m (U, t) is the time t The lower boundary curve of instantaneous friction and wear on the flank of milling cutter teeth.

Step D: Boundary solution and verification method of cumulative friction and wear on the flank of the cutter tooth

Step D1 Calculate the boundary of cumulative friction and wear on the flank of milling cutter teeth

During the milling process, affected by the milling vibration and cutter tooth error, the instantaneous contact boundary between the milling cutter tooth flank and the transition surface of the workpiece changes dynamically with time, and the cumulative friction and wear boundary of the milling cutter tooth flank is determined by several The instantaneous friction and wear boundary is cumulatively formed. Based on the above analysis, taking the lower boundary of the simulation of the cumulative friction and wear of the flank of the milling cutter as an example, the lower boundary curve of the instantaneous friction and wear of the flank of the cutter tooth at different milling times is extracted, as shown in Figure 23. The calculation method of the cumulative friction and wear boundary of the flank of the milling cutter tooth flank is proposed, as shown in equations (4-1) and (4-2).

V _a (U _i ,Δt)=max{V _m (U _i ,t ₁ ),V _m (U _i ,t ₂ )...V _m (U _i ,t _n )}Δt=t _n -t ₁ (4-1)

V _a (U,Δt)={V _a (U ₁ ,Δt),V _a (U ₂ ,Δt)...V _a (U _i ,Δt)} (4-2)

In formula (4-1), V _a (U _i ,Δt) is the V coordinate value of the cumulative friction and wear boundary curve of the flank of the milling cutter tooth flank at the position U _i in the Δt time period, in formula (4-2) , V _a (U, Δt) is the cumulative friction and wear boundary curve of the flank of the milling cutter tooth in the Δt time period.

Step D2 The lower boundary simulation and experiment comparison scheme of the cumulative friction and wear of the flank of the cutter tooth

In order to verify the correctness of the calculation method of the cumulative friction and wear boundary of the high-efficiency milling cutter, the upper and lower boundary simulation and identification criteria of the instantaneous friction and wear of the milling cutter tooth flank in steps C4 and C5 are firstly used, and the thermal coupling field simulation in step C1 is extracted. At 0.5m, 1m, 1.5m, 2m, 2.5m, 3m, 3.5m, 4m, 4.5m, and 5m, the upper and lower boundaries of instantaneous friction and wear of each cutter face of the milling cutter are simulated. Take cutter 1 as an example, as shown in Figure 24 shown.

Using the calculation method of the cumulative friction and wear boundary curve of the flank of the milling cutter tooth in step D1, the upper and lower boundary curves of the cumulative friction and wear simulation of the flank face of the milling cutter tooth are constructed, and the milling cutter tooth with a milling stroke of 5m in step A4 The upper and lower boundary curves of the friction and wear of the flank face experiment are compared, taking the first tooth as an example, as shown in Figure 25.

Step D3 Simulation and Experiment Cumulative Friction and Wear Boundary Shape and Position Similarity Analysis

Calculate the grey correlation value and average relative error between the simulation and experimental cumulative friction and wear boundary curves, analyze the shape similarity and position coincidence between the simulation and experimental wear boundary curves, and verify the correctness of the cumulative friction and wear boundary solution method. The steps of the grey relational analysis method are as follows:

First, the V-axis coordinate values of the experimental and simulated tool tooth flank wear boundary feature points are used as the reference sequence and the comparison sequence, such as formulas (4-3) and (4-4).

_Vq =( _Vq (1), _Vq (2),..., _Vq (m),..., _Vq (n)) (4-3)

_Vq *=( _Vq (1)*, _Vq (2)*,..., _Vq (m)*,..., _Vq (n)*) (4-4)

In formulas (4-3) and (4-4), V _q (m) and V _q (m)* are the upper edge of the flank wear boundary curve of the qth (0≤q≤3) tooth in the experiment and simulation, respectively. The coordinate value V _m of the m-th feature point in the cutting edge direction in the V direction.

The calculation method of the average relative error of the flank wear curve of the simulated and experimental tool teeth is shown in formula (4-5).

In formula (4-5), δ _q is the relative error of the flank wear boundary curve of the qth tooth in the simulation and experiment.

Using the above correlation degree and average relative error calculation method, the correlation degree and relative error of the upper and lower boundary curves of simulated and experimental tool tooth flank wear are shown in Table 4-1, where γ(V _q ,V _q *)(1≤q ≤3) represents the grey correlation degree between the tool tooth q simulation and the experimental cumulative friction and wear boundary curve, and δ _q represents the average relative error between the tool tooth q simulation and the experimental cumulative wear boundary curve.

Table 4-1 Correlation degree and relative error of upper and lower boundary curves of flank wear between simulation and experiment

From Table 4-1, the correlation degree between the simulation of the flank of each tooth of the milling cutter and the upper and lower boundary curves of the cumulative friction and wear of the milling cutter are all above 0.75, and the average relative error is less than 20%. The results show that the flank of each tooth of the milling cutter The surface simulation and the experimental cumulative friction and wear boundary curve shape and position have high similarity, the effectiveness of the high-efficiency milling cutter axial layer milling simulation model design method, and also verifies the milling cutter tooth flank cumulative friction and wear boundary The correctness of the solution method.

The above are only preferred specific embodiments of the present invention, and these specific embodiments are based on different implementations under the overall concept of the present invention, and the protection scope of the present invention is not limited to this. Anyone familiar with the technical field Changes or substitutions that can be easily conceived by a skilled person within the technical scope disclosed by the present invention shall be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (4)

1. A high-efficiency milling cutter accumulated friction and wear boundary identification and verification method is characterized by comprising the following steps:

step A: providing a method for measuring and characterizing the frictional wear boundary of the rear cutter face of the cutter tooth of the efficient milling cutter, constructing a measuring coordinate system of the frictional wear boundary of the rear cutter face of the cutter tooth of the milling cutter, and characterizing the shape and the position of the frictional wear boundary of the rear cutter face of the cutter tooth on a plane parallel to a measuring coordinate system parallel to a mid-point tangent plane of the cutting edge of the cutter tooth;

the step A further comprises the following steps:

step A1: the milling mode of the efficient milling cutter under the vibration action is as follows: in a workpiece coordinate system, reflecting the influence of milling vibration on the cutting process of the efficient milling cutter by using the cutting state of the milling cutter under the biasing and vibration effects of the milling cutter coordinate system;

step A2: determining a milling cutter tooth error and a method for measuring a frictional wear boundary of a rear cutter face of the milling cutter according to the structural characteristics of the efficient milling cutter;

step A3: measuring a relation matrix between a coordinate system by utilizing a workpiece coordinate system, a milling cutter coordinate system, a cutter tooth coordinate system and a rear cutter face friction and wear boundary under the influence of milling vibration and cutter tooth error, and reflecting the influence of the milling vibration and the cutter tooth error on the instantaneous contact relation between the rear cutter face of the cutter tooth and the workpiece;

step A4: sequentially measuring frictional wear boundary end points and inflection points of the rear cutter face of the cutter tooth in a cutter tooth rear cutter face wear boundary measurement coordinate system, constructing an upper boundary curve and a lower boundary curve of frictional wear of the rear cutter face of the cutter tooth of the milling cutter, and determining a frictional wear boundary of the rear cutter face of the cutter tooth;

and B: considering a milling mode, milling vibration, cutter tooth errors and differences of surfaces to be machined of different layers as simulation boundary conditions, and providing an axial layered milling simulation model of the efficient milling cutter and a boundary condition construction method;

and C: carrying out axial layered milling thermal coupling field simulation on the efficient milling cutter by using an axial layered milling simulation model of the efficient milling cutter, extracting an instantaneous temperature, an equivalent stress and an equivalent strain distribution field of a rear cutter face of a cutter tooth of the milling cutter, and providing a method for identifying an instantaneous frictional wear simulation boundary of the rear cutter face of the cutter tooth according to the process of forming the instantaneous frictional wear boundary of the rear cutter face of the cutter tooth of the milling cutter;

step D: and C, acquiring instantaneous frictional wear boundaries of the rear cutter face of the cutter tooth at different moments, analyzing the formation process of the accumulated frictional wear boundaries of the rear cutter face of the cutter tooth, providing a simulation boundary calculation method for the accumulated frictional wear boundaries of the rear cutter face of the cutter tooth of the milling cutter, calculating the gray correlation degree and average relative error of the curve of the accumulated frictional wear boundaries of the rear cutter face of the cutter tooth of the milling cutter obtained through simulation and experiments, and verifying the correctness of the calculation method for the accumulated frictional wear boundaries of the rear cutter face of the cutter tooth of the milling cutter.

2. A high efficiency milling cutter cumulative frictional wear boundary identification and verification method as claimed in claim 1, wherein: the step B further comprises the following steps:

step B1: considering a milling mode, a cutter tooth error, milling vibration and differences of surfaces to be machined of different layers as simulation boundary conditions, designing an integral structure of an axial layered milling simulation model of the efficient milling cutter, and determining and resolving design variables of the simulation model;

step B2: constructing a simulation model milling unit, solving a milling cutter motion track and an instantaneous cutting attitude angle under the action of vibration, determining a milling unit cross section model, and constructing the milling unit by considering milling vibration and cutter tooth errors;

step B3: in the simulation process, according to the milling cutter motion trail under the vibration action in the axial layered milling experiment, determining the discrete time interval of the milling cutter motion trail points, and resolving the milling cutter motion trail points under the vibration action in the simulation process.

3. A high efficiency milling cutter cumulative frictional wear boundary identification and verification method as claimed in claim 2, wherein: the step C further comprises the following steps:

step C1: carrying out thermal coupling field simulation through an efficient milling cutter axial layered milling simulation model, and extracting the distribution conditions of an equivalent stress field, an equivalent strain field and a temperature field of the free instantaneous cutting of the rear cutter face of the cutter tooth of the milling cutter;

step C2: extracting node equivalent stress, equivalent strain and temperature values at different positions of a rear cutter face of the cutter tooth of the milling cutter, constructing a cutter face equivalent stress, equivalent strain and temperature distribution curved surface of the cutter tooth, sequentially making section planes which are perpendicular to the distribution curved surface through nodes on cutting edges in the direction of a midpoint normal vector of the cutting edges on a projection plane of the rear cutter face of the cutter tooth in parallel, and constructing section plane equivalent stress, equivalent strain and temperature distribution curves of the nodes on the section planes at different positions of the rear cutter face of the cutter tooth;

step C3: sequentially fitting equivalent stress, equivalent strain and temperature distribution curves of each section plane of the rear cutter face of the cutter tooth by adopting a unary high-order polynomial, and obtaining a node change rate distribution curve by derivation;

step C4: identifying critical characteristic nodes with equivalent stress larger than and closest to yield on all section planes by taking the yield strength of the cutter tooth material as a criterion, wherein characteristic points on the section planes at different positions in a friction and wear measurement coordinate system of the cutter tooth rear cutter face jointly form an instantaneous friction and wear simulation upper boundary of the cutter tooth rear cutter face;

step C5: and sequentially identifying nodes with obvious abrupt changes in temperature, equivalent stress and equivalent strain change rate at each section plane of the rear cutter face of the cutter tooth, constructing a node temperature, equivalent stress and equivalent strain abrupt change characteristic curve on the rear cutter face of the cutter tooth in a frictional wear boundary measurement coordinate system by taking the abrupt change nodes as characteristic points, and forming an outermost profile jointly formed by the node temperature, the equivalent strain and the equivalent strain abrupt change characteristic curve to form an instantaneous frictional wear simulation lower boundary of the rear cutter face of the cutter tooth.

4. A high efficiency milling cutter cumulative frictional wear boundary identification and verification method as claimed in claim 1, wherein: the step D further comprises the following steps:

step D1: by means of the instant frictional wear boundary curve of the rear cutter face of the cutter tooth at different milling moments, taking the accumulated frictional wear lower boundary curve as an example, a method for calculating the accumulated frictional wear boundary of the rear cutter face of the cutter tooth of the milling cutter is provided;

step D2: designing a simulation and experiment comparison scheme of upper and lower boundaries of accumulated friction wear of the rear cutter face of the cutter tooth, constructing a simulation upper and lower boundary curve of the accumulated friction wear of the rear cutter face of the cutter tooth of the milling cutter by adopting a calculation method of the curve of the accumulated friction wear boundary of the rear cutter face of the cutter tooth of the milling cutter, and comparing the experiment upper and lower boundary curve of the accumulated friction wear with the simulation upper and lower boundary curve;

step D3: and calculating a grey correlation value and a mean relative error between simulation and experiment accumulated friction and wear boundary curves, analyzing shape similarity and position contact ratio between the simulation and experiment accumulated friction and wear boundary curves, and verifying the correctness of the accumulated friction and wear boundary calculation method.

Images