Method for calculating instantaneous cutting depth of left-handed and right-handed cutting edges of multi-edge micro-tooth milling cutter

Abstract

The invention provides a method for calculating the instantaneous cutting depth of left and right rotating cutting edges of a multi-edge micro-tooth milling cutter, and relates to the technical field of machining. According to the method, geometric characteristics of the multi-edge micro-tooth milling cutter are fully considered, and gaps between different positions of a left-hand cutting edge of the multi-edge micro-tooth milling cutter and the circumference of the cutter are calculated by setting circumferential milling machining parameters and geometric parameters of the cutter; and calculating the instantaneous cutting depths of different positions of the left-handed and right-handed cutting edges of the multi-edge micro-tooth milling cutter according to the processing amount in the milling process and the position relation of the adjacent micro-teeth. According to the method, the influence of the gap between the left-handed cutting edge and the circumference of the multi-edge micro-tooth milling cutter on the cutting depth of the multi-edge micro-tooth milling cutter and the influence of the position relation of the left-handed cutting edge and the right-handed cutting edge of the adjacent micro-teeth on the milling process are considered, so that accurate calculation of the instantaneous cutting depth of the left-handed cutting edge and the right-handed cutting edge of the multi-edge micro-tooth milling cutter is realized; and an accurate instantaneous cutting depth change range is provided when the CFRP is milled by the multi-blade micro-tooth milling cutter, so that a parameter optimization basis is provided for inhibiting the CFRP milling damage.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, in particular to a method for calculating the instantaneous cutting depth of left-handed and right-handed cutting edges of a multi-edge micro-tooth milling cutter. Background Art

[0002] Carbon fiber reinforced resin matrix composites (CFRP) have strong designability and can be directly designed and integrally manufactured according to the size and performance requirements of the expected structure. However, the formed CFRP parts must be assembled and connected with other CFRP parts or metal parts. Therefore, peripheral milling of edges and windows is an essential process in the application of CFRP. However, during the peripheral milling of CFRP, the fibers are not easily cut due to the weak constraint of the surface material, which causes burr damage and reduces the quality of CFRP peripheral milling. Therefore, the effective cutting of the surface fibers by the cutting edge is the key to inhibiting burr damage, and whether the surface fibers can be effectively cut is related to the constraint state of the fibers and cutting parameters during the cutting process. The multi-blade micro-tooth milling cutter is formed by interlacing and grinding different numbers of right-handed spiral grooves and left-handed spiral grooves to form discrete micro-tooth units, each of which has a left-handed cutting edge and a right-handed cutting edge. When the left-handed and right-handed cutting edges cut the surface materials, both the upper and lower surfaces can be in a strong constraint state, which is conducive to the breakage of the surface fibers. However, when a multi-blade micro-tooth milling cutter is milling CFRP, the left-handed and right-handed cutting edges will affect their actual cutting depth due to the presence of the back cutter surface, and the positional relationship between the left-handed and right-handed cutting edges of adjacent micro-teeth will also affect the micro-teeth cutting depth during peripheral milling. These factors will cause the instantaneous cutting depths of the left-handed and right-handed cutting edges of the multi-blade micro-tooth milling cutter to be different at different positions, thereby affecting the cutting removal of the surface material. If the instantaneous cutting depth range of each cutting edge cannot be reasonably controlled, serious burr damage will still occur during the milling of CFRP by a multi-blade micro-tooth milling cutter. Therefore, for a multi-blade micro-tooth milling cutter with left-handed and right-handed cutting edges and a certain arrangement rule, it is necessary to develop a method for calculating the instantaneous cutting depth of the left-handed and right-handed cutting edges of a multi-blade micro-tooth milling cutter, obtain the instantaneous cutting depth variation range of the cutting edge of the multi-blade micro-tooth milling cutter under certain cutting parameters, and then select a suitable cutting parameter range to achieve effective suppression of burr damage by a multi-blade micro-tooth milling cutter.

[0003] In the existing literature, Sheikh-Ahmad et al. published the article "Cutting force prediction in milling CFRPs with complex cutter geometries" in the Journal of Manufacturing Processes, Vol. 45, 2019, pp. 720-731, which proposed a method for predicting the milling force of CFRP with a multi-edge micro-tooth milling cutter, and then studied the influence of the milling cutter geometry on the milling force. However, in this study, the cutting depth of the multi-edge micro-tooth milling cutter is only related to the feed per tooth and the cutting angle. The research content does not involve the influence of the back angle, the different positions of the cutting edges with different rotation directions, and the position relationship of the left-handed and right-handed cutting edges of the adjacent micro-teeth on the instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-edge micro-tooth milling cutter. The research results cannot provide a reference for the optimization of the processing parameters of the multi-edge micro-tooth milling cutter. Summary of the invention

[0004] In view of the deficiencies of the above-mentioned prior art, the present invention proposes a method for calculating the instantaneous cutting depth of the left-handed and right-handed cutting edges of a multi-blade micro-tooth milling cutter based on the geometric characteristics of the multi-blade micro-tooth milling cutter and the movement characteristics of the tool during peripheral milling. The method accurately realizes the calculation of the instantaneous cutting depth of the multi-blade micro-tooth milling cutter, has a simple form, is easy to use, and has good engineering application prospects.

[0005] The present invention proposes a method for calculating the instantaneous cutting depth of left-handed and right-handed cutting edges of a multi-edge micro-tooth milling cutter, the method comprising the following steps:

[0006] Step 1: Set the geometric parameters and milling parameters of the multi-edge micro-tooth milling cutter;

[0007] Step 2: Calculate the clearance between the left-handed cutting edge at different positions and the tool circumference according to the geometric structure parameters of the multi-edge micro-tooth milling cutter;

[0008] Step 3: Calculate the instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-edge micro-tooth milling cutter according to the milling processing parameters and the clearance between the left-handed cutting edge at different positions and the tool circumference;

[0009] The geometric parameters of the multi-edge micro-tooth milling cutter in step 1 include: tool radius R, tool back angle α, right-handed cutting edge length L R , Left-handed cutting edge length L L , right-hand helix angle β R and the left-hand helix angle β L ;

[0010] The milling parameters described in step 1 include: feed per tooth f Z and radial depth of cut a e ;

[0011] The calculation method of the gap between the left-handed cutting edge at different positions and the tool circumference in step 2 is as follows: for any micro-tooth of the multi-edge micro-tooth milling cutter, the point where the left-handed cutting edge and the right-handed cutting edge intersect is marked as B, the milling cutter is cut radially, and the intersection line of the section and the back tool surface is marked as BB'; observe the micro-tooth in the direction perpendicular to the back tool surface, mark any point on the left-handed cutting edge as point D, and the distance between point D and point B is marked as d BD ; Draw an auxiliary line that coincides with point D and is parallel to the right-handed cutting edge. The intersection of the auxiliary line and BB' is recorded as point C. The gap between point C and the tool circumference is the same as the gap between point D and the tool circumference. The distance between point B and point C is recorded as d BC , and there are:

[0012] d BC =d BD sin(β R +β L ) / sin(90°-β R ) (1)

[0013] Draw an auxiliary line connecting the tool center and point C, and record the intersection of the auxiliary line and the tool circumference as E; establish the origin of the coordinate system with the tool center O, the direction of the straight line where OB is located as the vertical axis of the coordinate system, and the direction perpendicular to the straight line where OB is located as the horizontal axis of the coordinate system, and then establish the coordinate system, and then obtain the circumference equation of the tool circumference and the equation of the straight line BC:

[0014]

[0015] Where x and y both represent unknown variables;

[0016] The horizontal and vertical coordinates of point C are expressed as:

[0017]

[0018] where x C is the horizontal coordinate of point C; C is the ordinate of point C;

[0019] At this time, the linear equation of the line where OC is located is:

[0020]

[0021] Combine the linear equation of the line where OC is located and the circular equation of the tool circumference to calculate the horizontal and vertical coordinates of point E:

[0022]

[0023] where x E is the horizontal coordinate of point E; y E is the ordinate of point E;

[0024] Then the gap d between point C and the tool circumference is CE for:

[0025]

[0026] According to the distance d between any point D and point B on the left-hand cutting edge BD , calculate the gap F(d BD ), where F(·) represents the gap between point D and the tool circumference and d BD The previous functional relationship;

[0027] The calculation method of the instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-blade micro-tooth milling cutter in step 3 is as follows: for any micro-tooth of the multi-blade micro-tooth milling cutter, along the circumference of the milling cutter, according to the geometric position relationship between the micro-tooth and the previous micro-tooth, the left-handed and right-handed cutting edges of the micro-tooth in the multi-blade micro-tooth milling cutter are divided into the following five parts:

[0028] Part 1: The overlapping part of the right-handed cutting edge in the micro-tooth and the right-handed cutting edge in the previous micro-tooth is recorded as segment A1B1. During cutting, there is no accumulation of uncut material on the cutting edge of segment A1B1. For this micro-tooth, the instantaneous cutting depth a of segment A1B1 in the right-handed cutting edge is c1 (x1) is:

[0029]

[0030] Where x1 is the distance between any point X and point A1 in the right-handed cutting edge, and in the first part, 0≤x1≤L A1B1 ; L A1B1 is the length of segment A1B1; is the cutting edge angle, and The value range is

[0031] The second part: The overlapping part of the right-handed cutting edge in the micro-tooth and the left-handed cutting edge in the previous micro-tooth is recorded as the B1C1 segment. During cutting, there is an accumulation of uncut materials from the left-handed cutting edge in the previous micro-tooth in the cutting edge of the B1C1 segment, and the depth of the uncut materials from the left-handed cutting edge is related to the gap between the left-handed cutting edge position and the tool circumference. For this micro-tooth, the instantaneous cutting depth a of the B1C1 segment in the right-handed cutting edge is c2 (x1) is:

[0032]

[0033] Where x1 is the distance between any point X and point A1 in the right-hand cutting edge, and in the second part, L A1B1 <x1≤L R; d is the distance between any position on the left-handed cutting edge in the previous micro-tooth and point B, and:

[0034] d=(x1-L A1B1 )cosβ R / cosβ L (9)

[0035] Part 3: The overlapping part of the left-handed cutting edge in the micro-tooth and the left-handed cutting edge in the previous micro-tooth is recorded as the C1D1 segment. During cutting, the cutting edge of the C1D1 segment contains the accumulation of uncut materials of the left-handed cutting edge in the previous micro-tooth and the uncut materials of the C1D1 segment. The gap between the left-handed cutting edge at different positions and the circumference is defined as F(y1), where y1 is the distance between any point Y and point B in the left-handed cutting edge. For this micro-tooth, the instantaneous cutting depth a of the C1D1 segment in the left-handed cutting edge is c3 (y1) is:

[0036]

[0037] Where L C1D1 is the length of the C1D1 segment, and:

[0038] L C1D1 =L L -(L R -L A1B1 )cosβ R / cosβ L (11)

[0039] At this time, the distance d between any position on the left-handed cutting edge in the previous micro-tooth and point B is:

[0040] d=(L R -L A1B1 )cosβ R / cosβ L +y1 (12)

[0041] Part 4: The part of the left-handed cutting edge in the micro-tooth that does not overlap with the previous micro-tooth is recorded as the D1E1 segment. During cutting, there is an accumulation of uncut materials in the cutting edge of the D1E1 segment and the uncut materials of the D1E1 segment. For this micro-tooth, the instantaneous cutting depth a of the D1E1 segment in the left-handed cutting edge is c4 (y1) is:

[0042]

[0043] Where L D1E1 is the length of the D1E1 segment, and:

[0044] L D1E1 =(Scosβ R-L L cosβ L ) / cosβ L (14)

[0045] Where S is the distance between adjacent micro-teeth along the right-handed spiral groove;

[0046] Part 5: The overlapping part of the left-handed cutting edge in the micro-tooth and the right-handed cutting edge in the previous micro-tooth is recorded as the E1F1 segment. During cutting, there is only uncut material of the E1F1 segment in the cutting edge of the E1F1 segment. For this micro-tooth, the instantaneous cutting depth a of the E1F1 segment in the left-handed cutting edge is c5 (y1) is:

[0047]

[0048] The beneficial effects of adopting the above technical solution are:

[0049] For a multi-blade micro-tooth milling cutter with left-handed and right-handed cutting edges and a certain arrangement rule, the method of the present invention takes into account the geometric characteristics of the multi-blade micro-tooth milling cutter, and first calculates the clearance between the left-handed cutting edge of the multi-blade micro-tooth milling cutter and the circumference at different positions by setting the peripheral milling processing parameters and the tool geometric parameters, and then calculates the instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-blade micro-tooth milling cutter at different positions. By considering the influence of the clearance between the left-handed cutting edge of the multi-blade micro-tooth milling cutter and the circumference on its actual cutting depth, and the influence of the positional relationship of the left-handed and right-handed cutting edges of adjacent micro-teeth on the actual milling process, the method of the present invention can improve the calculation accuracy and realize the accurate calculation of the instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-blade micro-tooth milling cutter, and has a good prospect for engineering application.

[0050] Compared with the existing methods, the method of the present invention proposes a calculation method for the instantaneous cutting depth of the left-handed and right-handed cutting edges of a multi-blade micro-tooth milling cutter, which can accurately calculate the instantaneous cutting depth of the left-handed and right-handed cutting edges under different tool geometric parameters and milling processing parameters. The method of the present invention can take into account the influence of the gap between the left-handed cutting edge and the circumference, and the cutting edge position relationship of adjacent micro-teeth on the actual instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-blade micro-tooth milling cutter, and provides a calculation method for the instantaneous cutting depth of the left-handed and right-handed cutting edges, which can provide an accurate instantaneous cutting depth variation range for the multi-blade micro-tooth milling cutter when milling CFRP, thereby providing a basis for optimizing parameters for suppressing CFRP milling damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a flow chart of a method for calculating the instantaneous cutting depth of left-handed and right-handed cutting edges of a multi-edge micro-tooth milling cutter in this embodiment;

[0052] Figure 2 Schematic diagram of the position relationship of the cutting edges of the multi-edge micro-tooth milling cutter in this embodiment;

[0053] Figure 3 It is a schematic diagram of the instantaneous cutting depth change at different positions of the left-hand and right-hand cutting edges of the multi-blade micro-tooth milling cutter in this embodiment; Figure (a) is a schematic diagram of the instantaneous cutting depth change at different positions of the right-hand cutting edge of the multi-blade micro-tooth milling cutter in this embodiment; Figure (b) is a schematic diagram of the instantaneous cutting depth change at different positions of the left-hand cutting edge of the multi-blade micro-tooth milling cutter in this embodiment. DETAILED DESCRIPTION

[0054] In order to facilitate the understanding of the present application, the specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly understood.

[0055] In this embodiment, first, based on the geometric structure parameters of the multi-blade micro-tooth milling cutter, the gap between the left-handed cutting edge of the multi-blade micro-tooth milling cutter and the tool circumference at different positions is calculated, and then based on the various processing quantities and the positional relationship between adjacent micro-teeth during the milling process, the instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-blade micro-tooth milling cutter at different positions is calculated, thereby accurately realizing the calculation of the instantaneous cutting depth of this type of tool.

[0056] A method for calculating the instantaneous cutting depth of a left-handed or right-handed cutting edge of a multi-edge micro-tooth milling cutter according to the present embodiment is as follows: Figure 1 As shown, the method comprises the following steps:

[0057] Step 1: Set the geometric parameters and milling parameters of the multi-edge micro-tooth milling cutter.

[0058] The geometric parameters of the multi-edge micro-tooth milling cutter include: tool radius R, tool back angle α, right-handed cutting edge length L R , Left-handed cutting edge length L L , right-hand helix angle β R and the left-hand helix angle β L .

[0059] In this embodiment, the geometric parameters of the multi-edge micro-tooth milling cutter are: tool radius R = 5 mm, tool back angle α = 5°, right-handed cutting edge length L R =1mm, left-hand cutting edge length L L =0.5mm, right-hand helix angle β R =30°, left-hand helix angle β L =48.99°.

[0060] The milling parameters include: feed per tooth f Z and radial depth of cut a e .

[0061] In this embodiment, the milling parameters selected are: feed per tooth f Z =0.05mm / tooth, radial cutting depth is a e =2.5mm.

[0062] Step 2: Calculate the gap between the left-handed cutting edge at different positions and the tool circumference based on the geometric structure parameters of the multi-edge micro-tooth milling cutter.

[0063] The calculation method of the gap between the left-handed cutting edge at different positions and the tool circumference is as follows: for any micro-tooth of the multi-edge micro-tooth milling cutter, the point where the left-handed cutting edge and the right-handed cutting edge intersect is marked as B, the milling cutter is cut in the radial direction, and the intersection line of the section and the back tool surface is marked as BB'; the micro-tooth is observed in the direction perpendicular to the back tool surface, and any point on the left-handed cutting edge is marked as point D, and the distance between point D and point B is marked as d BD ; Draw an auxiliary line that coincides with point D and is parallel to the right-handed cutting edge. The intersection of the auxiliary line and BB' is recorded as point C. The gap between point C and the tool circumference is the same as the gap between point D and the tool circumference. The distance between point B and point C is recorded as d BC , and there are:

[0064] d BC =d BD sin(β R +β L ) / sin(90°-β R ) (1)

[0065] Draw an auxiliary line connecting the tool center and point C, and record the intersection of the auxiliary line and the tool circumference as E; establish the origin of the coordinate system with the tool center O, the direction of the straight line where OB is located as the vertical axis of the coordinate system, and the direction perpendicular to the straight line where OB is located as the horizontal axis of the coordinate system, and then establish the coordinate system, and then obtain the circumference equation of the tool circumference and the equation of the straight line BC:

[0066]

[0067] Where x and y are unknown variables.

[0068] The horizontal and vertical coordinates of point C are expressed as:

[0069]

[0070] where x C is the horizontal coordinate of point C; C is the ordinate of point C.

[0071] At this time, the linear equation of the line where OC is located is:

[0072]

[0073] Combine the linear equation of the line where OC is located and the circular equation of the tool circumference to calculate the horizontal and vertical coordinates of point E:

[0074]

[0075] where x E is the horizontal coordinate of point E; y E is the ordinate of point E.

[0076] Then the gap d between point C and the tool circumference is CE for:

[0077]

[0078] According to the distance d between any point D and point B on the left-hand cutting edge BD , calculate the gap F(d BD ), where F(·) represents the gap between point D and the tool circumference and d BD The previous functional relationship.

[0079] In this embodiment, formulas (1) to (6) are combined to determine the basic geometric parameters of the multi-edge micro-tooth milling cutter. Since the gap between any point D on the left-handed cutting edge and the tool circumference is the same as the gap between point C and the tool circumference, the gap between any point D on the left-handed cutting edge and the circumference and d BD To facilitate subsequent calculations, the clearance between any point on the left-handed cutting edge and the circumference is expressed as BD The function F(d BD ), calculate the clearance between the left-hand cutting edge and the circumference as shown in Table 1.

[0080] Table 1 Clearance between left-handed cutting edge at different positions and the circumference

[0081]

[0082] Step 3: Calculate the instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-edge micro-tooth milling cutter based on the milling processing parameters and the clearance between the left-handed cutting edge at different positions and the tool circumference.

[0083] The calculation method of the instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-blade micro-tooth milling cutter is as follows: for any micro-tooth of the multi-blade micro-tooth milling cutter, along the circumference of the milling cutter, according to the geometric position relationship between the micro-tooth and the previous micro-tooth, the left-handed and right-handed cutting edges of the micro-tooth in the multi-blade micro-tooth milling cutter are divided into the following five parts:

[0084] Part 1: The overlapping part of the right-handed cutting edge in the micro-tooth and the right-handed cutting edge in the previous micro-tooth is recorded as segment A1B1. During cutting, there is no accumulation of uncut material on the cutting edge of segment A1B1. For this micro-tooth, the instantaneous cutting depth a of segment A1B1 in the right-handed cutting edge is c1 (x1) is:

[0085]

[0086] Where x1 is the distance between any point X and point A1 in the right-handed cutting edge, and in the first part, 0≤x1≤L A1B1 ; L A1B1 is the length of segment A1B1; is the cutting edge angle, and The value range is

[0087] The second part: The overlapping part of the right-handed cutting edge in the micro-tooth and the left-handed cutting edge in the previous micro-tooth is recorded as the B1C1 segment. During cutting, there is an accumulation of uncut materials from the left-handed cutting edge in the previous micro-tooth in the cutting edge of the B1C1 segment, and the depth of the uncut materials from the left-handed cutting edge is related to the gap between the left-handed cutting edge position and the tool circumference. For this micro-tooth, the instantaneous cutting depth a of the B1C1 segment in the right-handed cutting edge is c2 (x1) is:

[0088]

[0089] Where x1 is the distance between any point X and point A1 in the right-hand cutting edge, and in the second part, L A1B1 <x1≤L R ; d is the distance between any position on the left-handed cutting edge in the previous micro-tooth and point B, and:

[0090] d=(x1-L A1B1 )cosβ R / cosβ L (9)

[0091] In this embodiment, the depth of the uncut material by the left-handed cutting edge is related to the gap between the position of the left-handed cutting edge and the circumference of the tool. The gap between the left-handed cutting edge of the previous micro-tooth and the circumference at different positions is defined as a function F(d), where d is the distance between any position of the left-handed cutting edge of the previous micro-tooth and its starting point, which is the same as d in the first step. BD The parameters have the same meaning.

[0092] Part 3: The overlapping part of the left-handed cutting edge in the micro-tooth and the left-handed cutting edge in the previous micro-tooth is recorded as the C1D1 segment. During cutting, the cutting edge of the C1D1 segment contains the accumulation of uncut materials of the left-handed cutting edge in the previous micro-tooth and the uncut materials of the C1D1 segment. The gap between the left-handed cutting edge at different positions and the circumference is defined as F(y1), where y1 is the distance between any point Y and point B in the left-handed cutting edge. For this micro-tooth, the instantaneous cutting depth a of the C1D1 segment in the left-handed cutting edge is c3 (y1) is:

[0093]

[0094] In the third part, 0≤y1≤L C1D1 ; L C1D1 is the length of the C1D1 segment, and:

[0095] L C1D1 =L L -(L R -L A1B1 )cosβ R / cosβ L (11)

[0096] At this time, the distance d between any position on the left-handed cutting edge in the previous micro-tooth and point B is:

[0097] d=(L R -L A1B1 )cosβ R / cosβ L +y1 (12)

[0098] In this embodiment, the gap between the left-handed cutting edge and the circumference at different positions is defined as a function F(y1), where y1 is the distance between any position of the left-handed cutting edge and its starting point, which is the same as d in the first step. BD The fourth part: The part of the left-handed cutting edge in the micro-tooth that does not overlap with the previous micro-tooth is recorded as the D1E1 segment. During cutting, there is an accumulation of uncut materials in the cutting edge of the D1E1 segment and the uncut materials of the D1E1 segment. For this micro-tooth, the instantaneous cutting depth a of the D1E1 segment in the left-handed cutting edge is c4 (y1) is:

[0099]

[0100] In the fourth part, L C1D1 <y1≤L C1D1 +L D1E1 ; L D1E1 is the length of the D1E1 segment, and:

[0101] L D1E1=(Scosβ R -L L cosβ L ) / cosβ L (14)

[0102] Where S is the distance between adjacent micro-teeth along the right-handed spiral groove.

[0103] Part 5: The overlapping part of the left-handed cutting edge in the micro-tooth and the right-handed cutting edge in the previous micro-tooth is recorded as the E1F1 segment. During cutting, there is only uncut material of the E1F1 segment in the cutting edge of the E1F1 segment. For this micro-tooth, the instantaneous cutting depth a of the E1F1 segment in the left-handed cutting edge is c5 (y1) is:

[0104]

[0105] In this embodiment, the cutting edge position relationship of adjacent micro-teeth of the multi-edge micro-tooth milling cutter is as follows: Figure 2 As shown, the cutting edge of each micro-tooth is divided into five parts, wherein A1B1 is the part where the right-handed cutting edge overlaps with the right-handed cutting edge of the previous micro-tooth, B1C1 is the part where the right-handed cutting edge overlaps with the left-handed cutting edge of the previous micro-tooth, C1D1 is the part where the left-handed cutting edge overlaps with the left-handed cutting edge of the previous micro-tooth, D1E1 is the part where the left-handed cutting edge does not overlap with the previous micro-tooth, E1F1 is the part where the left-handed cutting edge overlaps with the right-handed cutting edge of the previous micro-tooth, and S is the spacing between adjacent micro-tooths along the right-handed spiral groove direction. Specifically, set L A1B1 =0.75mm, L B1C1 =0.25mm, L C1D1 =0.17mm, L D1E1 =0.16mm, L E1F1 =0.17mm, S =0.5mm, and the instantaneous cutting depth changes at different positions of the right-handed cutting edge and the left-handed cutting edge are calculated according to formulas (7) to (15), respectively. Figure 3 (a) and Figure 3 As shown in (b), it can be seen that the instantaneous cutting depths of different parts of the cutting edge have significant differences. The instantaneous cutting depth calculation method for the left-hand and right-hand cutting edges of the multi-edge micro-tooth milling cutter provided in this embodiment can provide an accurate cutting depth variation range for the multi-edge micro-tooth milling cutter to mill CFRP, thereby providing a basis for suppressing CFRP processing damage and optimizing parameters.

[0106] To summarize, this embodiment first calculates the gap between the left-handed cutting edge of the multi-blade micro-tooth milling cutter and the tool circumference at different positions based on the geometric structure parameters of the multi-blade micro-tooth milling cutter, and then calculates the instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-blade micro-tooth milling cutter at different positions based on the various processing quantities and the positional relationship between adjacent micro-teeth during the milling process, thereby accurately realizing the calculation of the instantaneous cutting depth of this type of tool.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of the present invention.

Claims

1. A method for calculating the instantaneous cutting depth of left-handed and right-handed cutting edges of a multi-edge micro-tooth milling cutter, characterized in that: The method comprises the following steps: Step 1: Set the geometric parameters and milling parameters of the multi-edge micro-tooth milling cutter; Step 2: Calculate the clearance between the left-handed cutting edge at different positions and the tool circumference according to the geometric structure parameters of the multi-edge micro-tooth milling cutter; Step 3: Calculate the instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-edge micro-tooth milling cutter based on the milling processing parameters and the clearance between the left-handed cutting edge at different positions and the tool circumference.

2. The method for calculating the instantaneous cutting depth of the left-handed and right-handed cutting edges of a multi-edge micro-tooth milling cutter according to claim 1, characterized in that: The geometric parameters of the multi-edge micro-tooth milling cutter in step 1 include: tool radius R, tool back angle α, right-handed cutting edge length L R , Left-handed cutting edge length L L , right-hand helix angle β R and the left-hand helix angle β L .

3. The method for calculating the instantaneous cutting depth of the left-handed and right-handed cutting edges of a multi-edge micro-tooth milling cutter according to claim 2, characterized in that: The milling parameters described in step 1 include: feed per tooth f Z and radial depth of cut a e .

4. A method for calculating the instantaneous cutting depth of left-handed and right-handed cutting edges of a multi-edge micro-tooth milling cutter according to claim 3, characterized in that: The calculation method of the gap between the left-handed cutting edge at different positions and the tool circumference in step 2 is as follows: for any micro-tooth of the multi-edge micro-tooth milling cutter, the point where the left-handed cutting edge and the right-handed cutting edge intersect is marked as B, the milling cutter is cut radially, and the intersection line of the section and the back tool surface is marked as BB'; observe the micro-tooth in the direction perpendicular to the back tool surface, mark any point on the left-handed cutting edge as point D, and the distance between point D and point B is marked as d BD ; Draw an auxiliary line that coincides with point D and is parallel to the right-handed cutting edge. The intersection of the auxiliary line and BB' is recorded as point C. The gap between point C and the tool circumference is the same as the gap between point D and the tool circumference. The distance between point B and point C is recorded as d BC , and there are: d BC =d BD sin(β R +b L ) / sin(90°-β R ) (1) Draw an auxiliary line connecting the tool center and point C, and record the intersection of the auxiliary line and the tool circumference as E; establish the origin of the coordinate system with the tool center O, the direction of the straight line where OB is located as the vertical axis of the coordinate system, and the direction perpendicular to the straight line where OB is located as the horizontal axis of the coordinate system, and then establish the coordinate system, and then obtain the circumference equation of the tool circumference and the equation of the straight line BC: Where x and y both represent unknown variables; The horizontal and vertical coordinates of point C are expressed as: where x C is the horizontal coordinate of point C; C is the ordinate of point C; At this time, the linear equation of the line where OC is located is: Combine the linear equation of the line where OC is located and the circular equation of the tool circumference to calculate the horizontal and vertical coordinates of point E: where x E is the horizontal coordinate of point E; E is the ordinate of point E; Then the gap d between point C and the tool circumference is CE for: According to the distance d between any point D and point B on the left-hand cutting edge BD , calculate the gap F(d BD ), where F(·) represents the gap between point D and the tool circumference and d BD The previous functional relationship.

5. A method for calculating the instantaneous cutting depth of left-handed and right-handed cutting edges of a multi-edge micro-tooth milling cutter according to claim 4, characterized in that: The calculation method of the instantaneous cutting depth of the left-handed and right-handed cutting edges of the multi-blade micro-tooth milling cutter in step 3 is as follows: for any micro-tooth of the multi-blade micro-tooth milling cutter, along the circumference of the milling cutter, according to the geometric position relationship between the micro-tooth and the previous micro-tooth, the left-handed and right-handed cutting edges of the micro-tooth in the multi-blade micro-tooth milling cutter are divided into the following five parts: Part 1: The overlapping part of the right-handed cutting edge in the micro-tooth and the right-handed cutting edge in the previous micro-tooth is recorded as segment A1B1. During cutting, there is no accumulation of uncut material on the cutting edge of segment A1B1. For this micro-tooth, the instantaneous cutting depth a of segment A1B1 in the right-handed cutting edge is c1 (x1) is: Where x1 is the distance between any point X and point A1 in the right-handed cutting edge, and in the first part, 0≤x1≤L A1B1 ; L A1B1 is the length of segment A1B1; is the cutting edge angle, and The value range is The second part: The overlapping part of the right-handed cutting edge in the micro-tooth and the left-handed cutting edge in the previous micro-tooth is recorded as the B1C1 segment. During cutting, there is an accumulation of uncut materials from the left-handed cutting edge in the previous micro-tooth in the cutting edge of the B1C1 segment, and the depth of the uncut materials from the left-handed cutting edge is related to the gap between the left-handed cutting edge position and the tool circumference. For this micro-tooth, the instantaneous cutting depth a of the B1C1 segment in the right-handed cutting edge is c2 (x1) is: Where x1 is the distance between any point X and point A1 in the right-hand cutting edge, and in the second part, L A1B1 <x1≤L R ; d is the distance between any position on the left-handed cutting edge in the previous micro-tooth and point B, and: d=(x1-L A1B1 )cosβ R / cosβ L (9) Part 3: The overlapping part of the left-handed cutting edge in the micro-tooth and the left-handed cutting edge in the previous micro-tooth is recorded as the C1D1 segment. During cutting, the cutting edge of the C1D1 segment contains the accumulation of uncut materials of the left-handed cutting edge in the previous micro-tooth and the uncut materials of the C1D1 segment. The gap between the left-handed cutting edge at different positions and the circumference is defined as F(y1), where y1 is the distance between any point Y and point B in the left-handed cutting edge. For this micro-tooth, the instantaneous cutting depth a of the C1D1 segment in the left-handed cutting edge is c3 (y1) is: Where L C1D1 is the length of the C1D1 segment, and: L C1D1 =L L -(L R -L A1B1 )cosβ R / cosβ L (11) At this time, the distance d between any position on the left-handed cutting edge in the previous micro-tooth and point B is: d=(L R -L A1B1 )cosβ R / cosβ L +y1 (12) Part 4: The part of the left-handed cutting edge in the micro-tooth that does not overlap with the previous micro-tooth is recorded as the D1E1 segment. During cutting, there is an accumulation of uncut materials in the cutting edge of the D1E1 segment and the uncut materials of the D1E1 segment. For this micro-tooth, the instantaneous cutting depth a of the D1E1 segment in the left-handed cutting edge is c4 (y1) is: Where L D1E1 is the length of the D1E1 segment, and: THE D1E1 =(Scosβ R -THE L what is it? L ) / cosβ L (14) Where S is the distance between adjacent micro-teeth along the right-handed spiral groove; Part 5: The overlapping part of the left-handed cutting edge in the micro-tooth and the right-handed cutting edge in the previous micro-tooth is recorded as the E1F1 segment. During cutting, there is only uncut material of the E1F1 segment in the cutting edge of the E1F1 segment. For this micro-tooth, the instantaneous cutting depth a of the E1F1 segment in the left-handed cutting edge is c5 (y1) is:

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