A carbide milling cutter with a composite rake angle, double-cut teeth and variable helix

Abstract

The present invention discloses a carbide milling cutter with a compound rake angle, double cutting teeth and variable helix, which can reduce the residence time of cutting chips on the rake face and improve the edge strength. It includes a tool shank and a tool head arranged at one end of the tool shank. The tool head includes cutting edges, a first chip flute and a second chip flute. The cutting edges include a plurality of non-equally distributed peripheral edges arranged on the outer wall surface of the tool head and an end edge arranged on the front cutting end face of the tool head. Each peripheral edge extends spirally along the tool head and is connected to the corresponding end edge integrally. Each first chip flute extends spirally and is connected to the corresponding second chip flute integrally. There are two compound rake angles at the top of the rake face: a first compound rake angle and a second compound rake angle. The planes where the first compound rake angle and the second compound rake angle are located are inclined planes. A double cutting tooth structure is arranged in the second chip flute. The double cutting tooth structure includes a first cutting tooth and a second cutting tooth connected to the first cutting tooth at a certain angle. A tooth gap strengthening arc is arranged between the first cutting tooth and the second cutting tooth.

Description

Technical Field

[0001] The invention relates to the technical field of milling cutters, in particular to a composite rake angle, double-cutting tooth variable spiral cemented carbide milling cutter. Background Art

[0002] Cemented carbide milling cutter refers to a milling cutter made of cemented carbide. Cemented carbide is a powder metallurgy product made of micron-sized powder of high-hardness refractory metal carbide (WC, TiC) as the main component, cobalt (Co) or nickel (Ni), molybdenum (Mo) as a binder, and sintered in a vacuum furnace or a hydrogen reduction furnace.

[0003] Taking a milling cutter with a blade diameter of D20mm as an example, under the milling parameters of speed S800, feed speed F100mm / min, axial cutting depth Ap3.0mm, and radial cutting depth Ae3.0mm, the tip (blade) of the milling cutter begins to break after about 3 hours of milling, and the cutting life of the tool is short. Analysis of the tool stiffness, chip removal, cutting vibration, etc. during the processing process shows that the reason for the short life of the milling cutter is that in order to improve the milling effect, the prepared tool blade has a single-edge angle structure a, and the second chip groove between the two adjacent end edges is deep, such as Figure 1 The milling cutter structure shown has an end cutting edge that is unequally distributed and has a single-edge angle structure a, namely, a first end cutting edge (i.e., bottom cutting edge), a second end cutting edge, a third end cutting edge, and a fourth end cutting edge. The front cutting edge of the cutting edge is provided with an arc-shaped groove a1. During the milling process using this type of milling cutter, the cutting chips are easily stored in the arc-shaped groove, which increases the residence time of the cutting chips on the front cutting edge. In addition, the strength of the single-edge angle cutting edge is poor, and the cutting chips impact and wear the cutting edge, which can easily cause damage to the cutting tip and result in a short service life. Summary of the invention

[0004] In view of the above technical problems existing in the prior art, the present invention provides a composite rake angle, double-cutting tooth variable spiral carbide milling cutter, which can reduce the residence time of cutting chips on the front cutting edge, improve the strength of the blade, and increase the service life of the milling cutter.

[0005] A composite rake angle, double-cutting-tooth variable spiral cemented carbide milling cutter, comprising a tool handle, a tool head arranged at one end of the tool handle, the tool head comprising a cutting edge, a first chip groove, and a second chip groove, the cutting edge comprising a plurality of unequally distributed peripheral cutting edges arranged on the outer wall surface of the tool head, and an end cutting edge arranged on the front cutting end surface of the tool head, the first chip groove being arranged between two adjacent peripheral cutting edges, the second chip groove being arranged between two adjacent end cutting edges, each of the peripheral cutting edges extending in a spiral shape along the tool head and being connected to the corresponding end cutting edge as a whole, each of the first chip grooves extending in a spiral shape and being connected to the corresponding second chip groove as a whole;

[0006] The peripheral blade comprises a peripheral blade rake face and a peripheral blade flank face, and the connecting surface between the peripheral blade rake face and the peripheral blade flank face is a peripheral blade cutting edge, characterized in that two compound angles are arranged at the top of the rake face: a first compound angle and a second compound angle, the plane where the first compound angle and the second compound angle are located is a spiral inclined surface, one end of the inclined surface is connected to the peripheral blade cutting edge, and the other end is connected to the second chip groove, and a point q is randomly selected at the rotation center of the milling cutter, and a perpendicular line from point q to the peripheral blade cutting edge is used as a reference line, and a point m is randomly selected at the other end of the inclined surface, and the angle between the perpendicular line from point m to the peripheral blade cutting edge and the reference line is the first compound rake angle; the point where the perpendicular line intersects the peripheral blade cutting edge is the perpendicular point n, and the transverse tangent of the peripheral blade cutting edge passing through the perpendicular point n intersects with the perpendicular line at a point k, and the angle between the connecting line formed by point k connecting point m and the perpendicular line is the second compound rake angle;

[0007] A double cutting tooth structure is arranged in the second chip groove, and the double cutting tooth structure includes a first cutting tooth and a second cutting tooth connected to the first cutting tooth at a certain angle, and the two ends of the first cutting tooth and the second cutting tooth are respectively connected to the bottom ends of the front cutting surface and the rear cutting surface of two adjacent end edges.

[0008] Its further characteristic is that

[0009] The first compound rake angle is -1°, the second compound rake angle is 5°, and the side width of the second compound rake angle is 1.0 mm;

[0010] The circumferential blade is a variable helix angle unequally divided tooth structure, and the circumferential blades include four: a first circumferential blade, a second circumferential blade, a third circumferential blade, and a fourth circumferential blade. The indexing angle of the first circumferential blade starts at 0°, the helix angle of the first circumferential blade is 36°, the angle between the first circumferential blade and the second circumferential blade is 84°, the helix angle of the second circumferential blade is 39°, the angle between the first circumferential blade and the third circumferential blade is 180°, the helix angle of the three circumferential blades is 36°, the angle between the first circumferential blade and the fourth circumferential blade is 264°, and the helix angle of the fourth circumferential blade is 39°;

[0011] The first cutting teeth, the second cutting teeth and the end edge rake face are connected by a tooth gap reinforcement arc, and the radius of the tooth gap reinforcement arc is 0.9 mm;

[0012] The tooth gap angle of the first cutting teeth is 20° to 25°, and the tooth gap angle of the second cutting teeth is 35° to 45°;

[0013] The first chip groove is a U-shaped structure.

[0014] The roughness of the circumferential blade rake face, the circumferential blade flank face, the end blade rake face, and the end blade flank face are all less than Ra0.15;

[0015] The connecting surface between the end edge rake face and the end edge flank face is the end edge cutting edge, the peripheral edge cutting edge extends in a spiral shape and is connected to the end edge cutting edge as a whole, and the passivation arc radius of the peripheral edge cutting edge and the end edge cutting edge is 0.008mm-0.010mm;

[0016] The materials of the knife handle and the knife head are both hard alloy.

[0017] A method for machining a composite rake angle, double-cutting-tooth variable-helix cemented carbide milling cutter, characterized in that the method comprises:

[0018] S1. Cutting the raw material by wire cutting to obtain a cylindrical blade;

[0019] S2, grinding the outer circle of the cutter body by centerless grinding, rough grinding and fine grinding in sequence;

[0020] S3, groove the cylindrical cutter body by grinding with a grinding wheel to obtain a first chip groove;

[0021] S4, using a grinding wheel to grind the first cutting tooth and the second cutting tooth in sequence to obtain a second chip groove;

[0022] S5, sharpening the edges by tool grinding to obtain the peripheral edges and end edges;

[0023] S6, grinding the first compound rake angle and the second compound rake angle in sequence by using a tool grinding method;

[0024] S7. Use sandblasting technology to perform sandblasting blunting on the peripheral edge and end edge;

[0025] S8. Perform PVD coating process on the outer surface of the peripheral edge and end edge.

[0026] Its further characteristic is that

[0027] The first chip groove is ground by a forming grinding wheel to obtain a U-shaped structure groove. The geometric shape of the grinding wheel is that the grinding reference plane angle is 50 degrees and the arc radius of the circumferential grinding point is 1.4 mm.

[0028] The method for processing sheet metal using the above-mentioned compound rake angle, double-cutting tooth variable spiral carbide milling cutter is to install the compound rake angle, double-cutting tooth variable spiral carbide milling cutter on a CNC machining center machine tool, and use the milling cutter blade to mill a cavity on both sides of the sheet metal, characterized in that the end blade of the milling cutter processes the cavity in a center ramp milling 3° feed mode;

[0029] During the machining process, the damage state of the cutting edge of the milling cutter was observed every hour.

[0030] Its further characteristic is that

[0031] During the milling process, the rotation speed of the milling cutter is 800r / min, the feed speed is 100mm / min, the axial cutting depth is 3.0mm, and the radial cutting depth is 3.0mm;

[0032] The sheet material is aviation high-strength steel;

[0033] The length, width and height of the sheet are 200 mm, 200 mm and 40 mm respectively; the length, width and height of the cavity are 180 mm, 87 mm and 30 mm respectively.

[0034] The above structure of the present invention can achieve the following beneficial effects: 1. The front cutting edge of the milling cutter is provided with two compound rake angles: a first compound rake angle and a second compound rake angle. The planes where the first compound rake angle and the second compound rake angle are located are inclined surfaces. Therefore, when the milling cutter blade is used for milling processing, the chips can be quickly discharged along the inclined surface, and the chip discharge direction is controlled, thereby reducing the residence time of the chips on the front cutting edge of the peripheral blade, avoiding the problem of the chips staying at the peripheral blade for a long time and causing impact and wear on the blade, resulting in damage to the blade, thereby improving the service life of the milling cutter.

[0035] 2. A double-tooth structure connecting the first cutting tooth and the second cutting tooth is provided in the second chip groove. The double-tooth structure is supported between the front cutting edge and the back cutting edge of two adjacent end cutting edges, and plays a supporting and strengthening role for the end cutting edges, thereby enhancing the strength of the end cutting edges; the two compound front angles of the front cutting edge of the peripheral cutting edge combined with the double-tooth structure between the two adjacent end cutting edges enhance the overall strength of the milling cutter and improve the service life of the milling cutter.

[0036] 3. In the processing method of the composite rake angle, double-cutting tooth variable spiral carbide milling cutter, the cylindrical cutter body is grooved by a grinding wheel grinding method to obtain the first chip groove. The grinding wheel grinding method is beneficial to increase the rigidity of the peripheral blade. This grinding method combines the two composite rake angles of the front cutting edge of the peripheral blade and the double cutting tooth structure between the two adjacent end blades to enhance the overall strength of the milling cutter. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 It is a schematic diagram of the three-dimensional structure of an existing milling cutter;

[0039] Figure 2 It is a three-dimensional structural schematic diagram of the milling cutter of the present invention;

[0040] Figure 3 It is a schematic diagram of the cross-sectional structure of the end edge of the milling cutter of the present invention when viewed from the front;

[0041] Figure 4 This is a schematic diagram of the enlarged structure of a portion of the peripheral blade of the present invention;

[0042] Figure 5 It is a structural schematic diagram of the peripheral blade indexing angle of the present invention;

[0043] Figure 6 It is a structural schematic diagram of the second peripheral blade helix angle of the present invention;

[0044] Figure 7 for Figure 5 Schematic diagram of the structure with the enlarged part A in the middle. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0047] Figure 1 An existing milling cutter structure is provided, wherein the end blade of the milling cutter structure comprises a first end blade, a second end blade, a third end blade, and a fourth end blade with unequal segmentation angles. Figure 1 It can be seen that the second chip groove between two adjacent end edges is a deep groove structure a2 with a relatively flat bottom. The front cutting edge of the end edge is only provided with a compound front angle (i.e., the single-edge angle structure a), and an arc-shaped groove a1 is opened at the top of the front cutting edge of the blade. When using this milling cutter for milling, the wear resistance of the blade with the single-edge angle structure a is poor, and the chips are easily stored in the arc-shaped groove a1, which increases the residence time of the chips in the arc-shaped groove. The chips impact and wear the end edge, resulting in damage to the tool tip and a short service life.

[0048] Aiming at the technical problems that the blade of the single composite rake angle structure in the prior art has poor wear resistance, the cutting chips are easily stored in the arc groove on the rake face of the blade, which increases the residence time of the cutting chips in the arc groove, and the cutting chips impact and wear the blade, resulting in damage to the blade tip and short service life, the following provides a specific embodiment of a composite rake angle, double cutting tooth variable spiral cemented carbide milling cutter, see Figure 2 to Figure 7 It includes a tool handle 1, a tool head 2 arranged at one end of the tool handle 1, the tool head 2 includes a cutting edge, a first chip groove 21, and a second chip groove 22. The cutting edge includes a plurality of unequally distributed peripheral cutting edges 23 arranged on the outer wall surface of the tool head, and an end cutting edge 24 arranged on the cutting end face of the front end of the tool head. The first chip groove 21 is arranged between two adjacent peripheral cutting edges 23, and the second chip groove 22 is arranged between two adjacent end cutting edges 24. Each peripheral cutting edge 23 extends in a spiral shape along the tool head and is connected to the corresponding end cutting edge 24 as a whole. Each first chip groove 21 extends in a spiral shape and is connected to the corresponding second chip groove 22 as a whole. The first chip groove 21 is a U-shaped structure.

[0049] The peripheral blade 23 includes a peripheral blade rake face and a peripheral blade flank face, and the end blade includes an end blade rake face and an end blade flank face. In order to improve the cutting effect and reduce cutting defects such as burrs and scratches, the roughness of the peripheral blade rake face, the peripheral blade flank face, the end blade rake face and the end blade flank face are all less than Ra0.15; the passivation arc radius of the peripheral blade cutting edge 230 between the peripheral blade rake face and the peripheral blade flank face, and the end blade cutting edge 240 between the end blade rake face and the end blade flank face are both 0.008-0.010mm. The passivation arc radius of the peripheral blade cutting edge 230 and the end blade cutting edge 240 is small, which is beneficial to improving the cutting effect of the blade.

[0050] Two compound rake angles are arranged at the top of the peripheral blade rake face: a first compound rake angle 31 and a second compound rake angle 32. The planes where the first compound angle 31 and the second compound angle 32 are located are spiral inclined surfaces 3. One end of the inclined surface 3 is connected to the peripheral blade cutting edge 230, and the other end is connected to the second chip groove 22. A point q is randomly selected at the rotation center of the milling cutter, and the vertical line from point q to the peripheral blade cutting edge is used as the reference line. A point m is randomly selected at the other end of the inclined surface, and the angle between the vertical line from point m to the peripheral blade cutting edge and the reference line is the first compound rake angle 31; the point where the vertical line intersects the peripheral blade cutting edge is the vertical point n, and the transverse tangent line of the peripheral blade cutting edge passing through the vertical point n intersects the vertical line at point k. The angle between the connecting line formed by point k connecting point m and the vertical line is the second compound rake angle 32. The first compound rake angle 31 is -1 degree, and the second compound rake angle 32 is 5 degrees. The width L of the inclined surface 3 is 1.0 mm. Figure 7 .

[0051] A double cutting tooth structure is arranged in the second chip groove 22, and the double cutting tooth structure comprises a first cutting tooth 41 and a second cutting tooth 42 connected to the first cutting tooth 41 at a certain angle, and the two ends of the first cutting tooth 41 and the second cutting tooth 42 are respectively connected to the end edge front cutting surface and the bottom end of the end edge rear cutting surface of the two adjacent end edges 24, and the tooth gap angle of the first cutting tooth 41 is 20°~25°, which is 20° in the present embodiment, and the tooth gap angle of the second cutting tooth 42 is 35°~45°, which is 35° in the present embodiment; one end of the first cutting tooth 41 and the second cutting tooth 42 is connected to the adjacent end edge front cutting surface through a tooth gap reinforcement arc 5, and the arc radius of the tooth gap reinforcement arc 5 is 0.9 mm. Compared with the existing method in which the second chip groove 22 is connected to the front cutting surface at a right angle or an obtuse angle, the setting of the tooth gap reinforcement arc 5 in the present application further enhances the rigidity of the end edge, which is beneficial to improving the strength of the end edge. The double-tooth structure of the first cutting tooth 41 and the second cutting tooth 42 is supported between the rake faces and flank faces of two adjacent end edges, supporting and reinforcing the end edges 24, thereby enhancing the strength of the end edges and increasing the life of the milling cutter.

[0052] The peripheral blade 23 is a variable helix angle unequally divided tooth structure, and the peripheral blade 23 includes four: a first peripheral blade 231, a second peripheral blade 232, a third peripheral blade 233, and a fourth peripheral blade 234. The indexing angle of the first peripheral blade 231 is a 0° starting angle, the helical angle of the first peripheral blade 231 is 36°, the angle between the first peripheral blade 231 and the second peripheral blade 232 is 84°, the helical angle of the second peripheral blade 232 is 39°, the angle between the first peripheral blade 231 and the second peripheral blade 232 is 180°, the helical angle of the third peripheral blade 233 is 36°, the angle between the first peripheral blade 231 and the fourth peripheral blade 234 is 264 degrees, and the helical angle of the fourth peripheral blade 234 is 39°, see Figure 5 , Figure 6 , where the helix angle is the angle between the radial tangent of each peripheral cutting edge and the center line of rotation.

[0053] The materials of the tool handle 1 and the tool head 2 are both cemented carbide. The use of cemented carbide material is conducive to further improving the overall rigidity and strength of the milling cutter, thereby further improving the service life of the milling cutter.

[0054] The above-mentioned composite rake angle, double-cutting tooth variable spiral cemented carbide milling cutter structure is obtained by processing, and the specific processing steps include:

[0055] S1. Cut the raw material by wire cutting to obtain a cylindrical blade of required length;

[0056] S2. Grind the outer circle of the cutter body by centerless grinding, rough grinding and fine grinding in sequence. Centerless grinding mainly drives the cylindrical cutter body to rotate on the grinding wheel through the guide wheel to grind the outer surface of the cylindrical cutter body. Centerless grinding has high precision and is conducive to quickly obtaining a cylindrical cutter body with a regular shape. After centerless grinding, the outer surface roughness of the cylindrical cutter body is processed by rough grinding and fine grinding in sequence to improve the surface smoothness of the cylindrical surface of the cylindrical cutter body.

[0057] S3. Use a grinding wheel grinding method to groove the cylindrical tool body to obtain the first chip groove. In this embodiment, the circumference of the molded grinding wheel is used for grinding, and the arc radian of the grinding wheel grinding blade is 1.4mm. The arc radian is calculated based on the diameter of the cylindrical tool body to be processed. The arc radian of the grinding wheel grinding surface = 7% * D, where D is the diameter of the cylindrical tool body. In this embodiment, the diameter of the cylindrical tool body is 20mm, and the grinding blade angle of the grinding wheel is 50 degrees. Compared with the processing method of using ordinary grinding wheels, the present application uses a molded grinding wheel with a circular grinding point arc radian of 1.4mm to obtain the first chip groove U-shaped structure molding groove type, which can obtain a larger chip removal space while ensuring strength, which is conducive to accurately controlling the width of the first chip groove, increasing the space of the first chip groove, and has little impact on other peripheral materials during the grinding process, thereby avoiding a reduction in the overall rigidity of the tool.

[0058] S4. Use a grinding wheel to grind the first tooth cutting and the second tooth cutting in sequence; during the tooth cutting process using the grinding wheel, different grinding wheel azimuth angles are input into the CNC machine tool. When processing the first tooth cutting, the grinding wheel azimuth angle is 20°~25°, and is 20° in this embodiment. The tooth gap angle of the first tooth cutting obtained by processing is 20°. When processing the second tooth cutting, the grinding wheel azimuth angle is 35°~45°, and is 35° in this embodiment. The tooth gap angle of the second tooth cutting obtained by processing is 35°.

[0059] S5. Use CNC tool grinding to obtain peripheral edge and end edge, that is, use CNC tool grinding to grind the blade surface.

[0060] S6. Use a CNC tool grinder to grind the first compound rake angle and the second compound rake angle in sequence; during the grinding process, input different grinding peripheral edge rake angles into the tool grinder to obtain a first compound rake angle of -1 degree and a second compound rake angle of 5 degrees.

[0061] S7, using a sandblasting process to perform sandblasting blunting treatment on the peripheral edge and the end edge. In this embodiment, the radius of the obtained cutting edge passivation arc is 0.008-0.010 mm, and in this embodiment, it is 0.008 mm;

[0062] S8. Perform PVD coating process on the outer surface of the blade.

[0063] In the above-mentioned processing technology S3, the grinding wheel grooving method is beneficial to increase the rigidity of the peripheral blade. In step S4, the first cutting tooth and the second cutting tooth are processed in sequence by the grinding wheel cutting method to obtain a double cutting tooth structure. In step S6, the double compound front angle structure of the first compound angle and the second compound angle obtained by the tool grinding method is beneficial to enhance the strength of the end blade. The enhancement of the strength of the peripheral blade and the end blade strengthens the overall strength of the milling cutter, which is beneficial to improve the life of the milling cutter.

[0064] The above-mentioned composite rake angle, double-cutting tooth variable spiral carbide milling cutter is used to process sheet materials, and the sheet materials are aviation high-strength steel; the length, width, and height of the sheet materials are 200mm, 200mm, and 40mm, respectively, and the length, width, and height of the cavity are 180mm, 87mm, and 30mm, respectively. When processing the sheet material cavity, first install the composite rake angle, double-cutting tooth variable spiral carbide milling cutter on the CNC machining center machine tool, and use the milling cutter blade to mill a cavity on both sides of the sheet material. The end edge of the milling cutter processes the cavity by center ramp milling 3° feed mode; during the milling process, the milling cutter speed is 800r / min, the feed speed is 100mm / min, the axial cutting depth is 3.0mm, and the radial cutting depth is 3.0mm. During the processing, the damage state of the milling cutter tip is observed every hour.

[0065] Under the conditions of a milling cutter rotation speed of 800r / min, a feed speed of 100mm / min, an axial cutting depth of 3.0mm, and a radial cutting depth of 3.0mm, the cutting life of the milling cutter in the prior art is basically maintained at about 3 hours before it starts to break. However, under the same milling parameter conditions, the cutting life of the milling cutter of the present application can be maintained for more than 5 hours without being broken, and the service life is significantly improved.

[0066] The above are only preferred embodiments of the present application, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the invention should be considered to be included in the scope of protection of the invention.

Claims

1. A composite rake angle, double-cutting-tooth variable spiral cemented carbide milling cutter, comprising a tool handle, a tool head arranged at one end of the tool handle, the tool head comprising a blade, a first chip groove, and a second chip groove, the blade comprising a plurality of unequally distributed peripheral blades arranged on the outer wall surface of the tool head, and an end blade arranged on the cutting end face of the front end of the tool head, the first chip groove is arranged between two adjacent peripheral blades, the second chip groove is arranged between two adjacent end blades, each of the peripheral blades extends helically along the tool head and is connected to the corresponding end blade as a whole, and each of the first chip grooves extends helically and is connected to the corresponding second chip groove as a whole; The peripheral blade comprises a peripheral blade rake face and a peripheral blade flank face, and the connecting surface between the peripheral blade rake face and the peripheral blade flank face is a peripheral blade cutting edge. It is characterized in that The top of the front cutting edge is provided with two compound rake angles: a first compound angle and a second compound angle. The planes where the first compound angle and the second compound angle are located are spiral inclined surfaces. One end of the inclined surface is connected to the peripheral cutting edge, and the other end is connected to the second chip groove. A point q is randomly selected at the rotation center of the milling cutter, and a vertical line from point q to the peripheral cutting edge is used as a reference line. A point m is randomly selected at the other end of the inclined surface, and an angle between a vertical line from point m to the peripheral cutting edge and the reference line is the first compound rake angle. The point where the vertical line intersects the peripheral cutting edge is the vertical point n. The transverse tangent of the peripheral cutting edge passing through the vertical point n intersects the vertical line at a point k. The angle between a connecting line formed by connecting point k and point m and the vertical line is the second compound rake angle. A double cutting tooth structure is arranged in the second chip groove, and the double cutting tooth structure includes a first cutting tooth and a second cutting tooth connected to the first cutting tooth at a certain angle, and the two ends of the first cutting tooth and the second cutting tooth are respectively connected to the bottom ends of the front cutting surface and the rear cutting surface of two adjacent end edges.

2. The composite rake angle, double-cutting tooth variable spiral carbide milling cutter according to claim 1, It is characterized in that The first compound rake angle is -1°, the second compound rake angle is 5°, and the width of the inclined surface is 1.0 mm.

3. The composite rake angle, double-cutting tooth variable spiral carbide milling cutter according to claim 2, It is characterized in that The circumferential blade is a variable helix angle unequally divided tooth structure, and the circumferential blade includes four: a first circumferential blade, a second circumferential blade, a third circumferential blade, and a fourth circumferential blade. The pitch angle of the first circumferential blade starts at 0°, the helix angle of the first circumferential blade is 36°, the angle between the first circumferential blade and the second circumferential blade is 84°, the helix angle of the second circumferential blade is 39°, the angle between the first circumferential blade and the third circumferential blade is 180°, the helix angle of the third circumferential blade is 36°, the angle between the first circumferential blade and the fourth circumferential blade is 264 degrees, and the helix angle of the fourth circumferential blade is 39°.

4. The composite rake angle, double-cutting tooth variable spiral cemented carbide milling cutter according to claim 1 or 3, It is characterized in that The first cutting teeth, the second cutting teeth and the end edge rake face are connected via a tooth gap reinforcement arc, and the radius of the tooth gap reinforcement arc is 0.9 mm.

5. The composite rake angle, double-cutting tooth variable spiral cemented carbide milling cutter according to claim 4, It is characterized in that The tooth gap angle of the first cutting teeth is 20° to 25°, and the tooth gap angle of the second cutting teeth is 35° to 45°.

6. The composite rake angle, double-cutting tooth variable spiral cemented carbide milling cutter according to claim 1, It is characterized in that The first chip groove is a U-shaped structure.

7. The composite rake angle, double-cutting tooth variable spiral cemented carbide milling cutter according to claim 1, It is characterized in that The connecting surface between the end edge rake face and the end edge flank face is the end edge cutting edge. The peripheral edge cutting edge extends spirally and is connected to the end edge cutting edge as a whole. The passivation arc radius of the peripheral edge cutting edge and the end edge cutting edge is 0.008mm to 0.010mm.

8. The composite rake angle, double-cutting tooth variable spiral cemented carbide milling cutter according to claim 1, It is characterized in that The materials of the knife handle and the knife head are both hard alloy.

9. A processing method for processing the composite rake angle, double-cutting tooth variable spiral cemented carbide milling cutter according to claim 1, It is characterized in that The method includes: S1. Cutting the raw material by wire cutting to obtain a cylindrical blade; S2, grinding the outer circle of the cutter body by centerless grinding, rough grinding and fine grinding in sequence; S3, groove the cylindrical cutter body by grinding with a grinding wheel to obtain a first chip groove; S4, using a grinding wheel to grind the first cutting tooth and the second cutting tooth in sequence to obtain a second chip groove; S5, sharpening the blade by CNC tool grinding to obtain the peripheral blade and end blade; S6, grinding the first compound rake angle and the second compound rake angle in sequence by using a CNC tool grinding method; S7. Use sandblasting technology to perform sandblasting blunting on the peripheral edge and end edge; S8. Perform PVD coating process on the outer surface of the peripheral edge and end edge.

10. The processing method according to claim 9, It is characterized in that The first chip groove is obtained by grinding with a profiled grinding wheel, and the geometric shape of the grinding wheel is that the grinding reference plane angle is 50 degrees and the arc of the circumferential grinding point is 1.4 mm.

Images