A high-efficiency chip-splitting milling cutter for deep hole enlargement

Abstract

The present invention discloses an efficient chip-splitting milling cutter that can be used for deep hole expansion processing, and belongs to the technical field of milling cutters. The efficient chip-splitting milling cutter of the present invention comprises a shank and a cutting part, and the cutting part has 4 to 12 circumferentially distributed spiral cutting edges, and the cutting edges have an unequal structure in the circumferential direction, and the difference between the maximum and minimum angles between the end edges of two adjacent cutting edges is 3.5° to 9°; each cutting edge is provided with a plurality of chip-splitting grooves at intervals along the axial direction, and the chip-splitting grooves on each cutting edge are staggered from each other in the axial direction. The efficient chip-splitting milling cutter of the present invention adopts an unequal design combined with a staggered tooth design of the chip-splitting groove, which effectively reduces the vibration during the processing of the chip-splitting milling cutter, is beneficial to the cutting force distribution, improves the processing accuracy and processing efficiency, and can be used for deep hole expansion processing, deep shoulder milling and deep groove milling, etc., and the chip size is controllable, and fine chips can be formed, which is convenient for chip cleaning, and the processing of parts with special requirements for chip formation is more perfect.

Description

Technical Field

[0001] The invention relates to a milling cutter, and more particularly to a high-efficiency chip-splitting milling cutter which can be used for deep hole enlarging processing. Background Art

[0002] A milling cutter is a rotary tool with one or more teeth used for milling. When working, each tooth cuts off the excess of the workpiece intermittently in sequence. Milling cutters are mainly used to process planes, steps, grooves, forming surfaces and cut off workpieces on milling machines. According to different processing characteristics, common types of milling cutters include cylindrical milling cutters, face milling cutters, end milling cutters, three-sided milling cutters, angle milling cutters, saw blade milling cutters and T-type milling cutters.

[0003] A milling cutter that can be used for hole expansion processing can be called a hole expansion milling cutter. Its structure generally includes a tool holder and a hole expansion milling part. The hole expansion milling part is generally used to side mill the workpiece. The chips generated during milling processing are usually long. Long chips are difficult to remove and can easily scratch the surface of the processed product, resulting in poor surface roughness. In addition, long chips are difficult to clean and can easily clog the holes of porous parts, making them usually difficult to use for deep hole processing. Chinese patent application No. 201310567409.7, application publication date is February 12, 2014, invention name: a chip-breaking end mill, the application case relates to a chip-breaking end mill, including a handle and a cutter head, the cutter head is provided with a side cutting edge and a bottom cutting edge, the side cutting edge includes two cutting edges and two corrugated cutting edges, the cutting edge and the corrugated cutting edge are arranged at intervals, a spiral side chip groove is arranged between the cutting edge and the corrugated cutting edge, the helix angle is 40°±2°, the cutting edge and the corrugated cutting edge have a width of 20±1mm, the blade inclination angle is 3°-5°, the bottom cutting edge is provided with four pieces, and a bottom chip groove is arranged between adjacent bottom cutting edges. The patent application adopts a cutting edge and a corrugated cutting edge combination design to realize the chip-breaking effect of the milling cutter, which has a certain chip-breaking effect, but the cutting edge and the corrugated cutting edge combination design also makes it difficult to further improve the milling efficiency and processing accuracy of the milling cutter.

[0004] Milling cutters with corrugated cutting edges are usually called corn milling cutters. Corn milling cutters are generally used for side milling rough processing. For example, the name disclosed in Chinese patent application No. 200810209547.7 is "double-ended wave-edge corn milling cutter". The double-ended wave-edge corn milling cutter has circumferential teeth on the cutter body, and double-ended wave-edge chip-breaking grooves are opened on the cutting edges of the circumferential teeth. This type of corn milling cutter also has a good chip-breaking effect, but cannot be used for deep hole expansion milling processing and can only be used for rough processing. Summary of the invention

[0005] 1. Technical problem to be solved by the invention

[0006] The purpose of the present invention is to overcome the shortcomings of existing chip milling cutters, such as low processing accuracy and processing efficiency, and difficulty in high-precision processing of deep holes or deep grooves, and to provide a high-efficiency chip milling cutter that can be used for deep hole expansion processing. The technical scheme of the present invention is adopted. The high-efficiency chip milling cutter adopts an unequal structure design, and the difference between the maximum and minimum angles between the end edges of two adjacent cutting edges is 3.5°~9°, and a plurality of chip grooves are arranged at intervals along the axial direction on each cutting edge, and the chip grooves on each cutting edge are staggered from each other in the axial direction. The unequal design combined with the staggered tooth design of the chip grooves effectively reduces the vibration of the chip milling cutter during processing, is beneficial to cutting force, improves processing accuracy and processing efficiency, can be used for deep hole expansion processing, deep square shoulder milling and deep groove milling, etc., and the chip size is controllable, can form fine chips, and is convenient for chip cleaning.

[0007] 2. Technical solution

[0008] In order to achieve the above object, the technical solution provided by the present invention is:

[0009] The invention discloses an efficient chip milling cutter which can be used for deep hole expansion processing, comprising a shank and a cutting portion arranged at the front of the shank, wherein the cutting portion has 4 to 12 circumferentially distributed spiral cutting edges, a spiral groove is arranged between two adjacent cutting edges, each cutting edge has an end edge arranged on the end face of the milling cutter and a peripheral edge arranged in the circumference of the milling cutter, the cutting edge of the efficient chip milling cutter has an unequal structure in the circumferential direction, and on the end face of the efficient chip milling cutter, the difference between the maximum value and the minimum value of the angle between the end edges of two adjacent cutting edges is 3.5° to 9°; each of the cutting edges is provided with a plurality of chip grooves spaced apart in the axial direction, and the chip grooves on each cutting edge are staggered in the axial direction.

[0010] Furthermore, at least one pair of values ​​of the angles between the end edges of two adjacent cutting edges are decimals.

[0011] Furthermore, the chip dividing groove is provided on the cutting edge along the circumferential direction of the high-efficiency chip dividing milling cutter.

[0012] Furthermore, the cross-sectional shape of the chip dividing groove is rectangular.

[0013] Furthermore, the blade length L3 between two adjacent chip dividing grooves on each cutting edge is determined according to the chip size.

[0014] Furthermore, the width L4 of the chip dividing groove is 0.5-1.5 mm.

[0015] Furthermore, the ratio of the length L2 of the cutting portion to the diameter D1 of the cutting portion is greater than or equal to 3.

[0016] Furthermore, the number of cutting edges of the cutting portion is determined according to the diameter D1 of the cutting portion. When the diameter D1 of the cutting portion is 6 to 12 mm, the cutting portion has 4 to 5 cutting edges; when the diameter D1 of the cutting portion is greater than 12 mm, the cutting portion has 6 to 12 cutting edges.

[0017] Furthermore, the end of each cutting edge has a front chamfer, and the front chamfer is 45°.

[0018] Furthermore, the peripheral edge of the cutting edge adopts a double clearance angle design, and the double clearance angle is 12° to 24°; the end edge clearance angle of the cutting edge is 10° to 23°.

[0019] 3. Beneficial effects

[0020] Compared with the existing known technologies, the technical solution provided by the present invention has the following significant effects:

[0021] (1) The present invention is a high-efficiency chip-splitting milling cutter that can be used for deep hole expansion processing, wherein the cutting portion has 4 to 12 circumferentially distributed spiral cutting edges, each cutting edge has an end edge arranged on the end face of the milling cutter and a circumferential edge arranged in the circumference of the milling cutter, and the cutting edge has an unequal structure in the circumferential direction, and the difference between the maximum and minimum values ​​of the angle between the end edges of two adjacent cutting edges is 3.5° to 9°. Each cutting edge is provided with a plurality of chip-splitting grooves at intervals along the axial direction, and the chip-splitting grooves on each cutting edge are staggered from each other in the axial direction; the high-efficiency chip-splitting milling cutter combines the unequal design of the cutting edge with the staggered tooth design of the chip-splitting groove, and the unequal design of the cutting edge can effectively reduce the vibration during the processing of the chip-splitting milling cutter, and the staggered tooth design of the chip-splitting groove is conducive to the cutting force, greatly improving the processing accuracy and processing efficiency. Compared with the existing milling cutters, the high-efficiency chip-splitting milling cutter can be used for deep hole expansion processing, deep shoulder milling and deep groove milling, etc., and the chip size is controllable, and fine chips can be formed, which is convenient for chip cleaning;

[0022] (2) The present invention is a high-efficiency chip-dividing milling cutter that can be used for deep hole expansion processing, wherein at least one pair of angle values ​​between the end edges of two adjacent cutting edges is a decimal. The unequal division design of the cutting edges makes the cutting vibration frequencies of the cutting edges different, further reducing the resonance of the cutting edges during the cutting process, ensuring the accuracy of the milling process, and being able to process at a higher cutting speed, thereby improving the processing efficiency;

[0023] (3) The invention provides a high-efficiency chip milling cutter that can be used for deep hole expansion processing, wherein the chip groove is provided on the cutting edge along the circumferential direction of the high-efficiency chip milling cutter, and the cross-sectional shape of the chip groove is rectangular, which is not only convenient for processing the chip groove, but also more convenient for chip breaking, so that the chips are miniaturized, and is particularly convenient for cleaning the chips in deep holes or deep grooves;

[0024] (4) The invention provides an efficient chip-dividing milling cutter for deep hole enlarging processing, wherein the blade length L3 between two adjacent chip-dividing grooves on each cutting edge is determined according to the chip size, and the width L4 of the chip-dividing groove is designed to be 0.5 to 1.5 mm. The blade length of the tool can be flexibly designed according to processing requirements, which is beneficial to improving the service life of the tool;

[0025] (5) The present invention is a high-efficiency chip milling cutter that can be used for deep hole expansion processing, in which the ratio of the length L2 of the cutting portion to the diameter D1 of the cutting portion is greater than or equal to 3, and the number of cutting edges of the cutting portion is determined according to the diameter D1 of the cutting portion, and can be used for deep hole expansion processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a three-dimensional structural schematic diagram of a high-efficiency chip-splitting milling cutter that can be used for deep hole expansion processing according to the present invention;

[0027] Figure 2 for Figure 1 Schematic diagram of the local enlarged structure at K in the middle;

[0028] Figure 3 It is a schematic side view of the structure of a high-efficiency chip-splitting milling cutter that can be used for deep hole expansion processing according to the present invention;

[0029] Figure 4 The present invention is a schematic diagram of an unequally divided design structure of a high-efficiency chip-dividing milling cutter that can be used for deep hole expansion processing.

[0030] Explanation of the symbols in the schematic diagram:

[0031] 1. Tool handle; 2. Cutting part; 2-1. Cutting edge; 2-2. Spiral groove; 2-3. End edge; 2-4. Chip groove; 2-5. Front chamfer. DETAILED DESCRIPTION

[0032] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings.

[0033] Combination Figures 1 to 4As shown, a high-efficiency chip milling cutter that can be used for deep hole expansion processing of the present invention includes a shank 1 and a cutting portion 2 arranged at the front of the shank 1, the cutting portion 2 has 4 to 12 circumferentially distributed spiral cutting edges 2-1, and the number of edges of the cutting portion 2 can be determined according to the diameter D1 of the cutting portion 2. In the present invention, when the diameter D1 of the cutting portion 2 is 6 to 12 mm, the cutting portion 2 has 4 to 5 cutting edges 2-1, that is, a four-edge or five-edge design is adopted; when the diameter D1 of the cutting portion 2 is greater than 12 mm, the cutting portion 2 has 6 to 12 cutting edges 2-1, that is, a six-edge, seven-edge, eight-edge or other design is adopted. There is a spiral groove 2-2 between two adjacent cutting edges 2-1, and the spiral groove 2-2 is used for chip storage and chip removal. Each cutting edge 2-1 has an end edge 2-3 arranged on the end face of the milling cutter and a peripheral edge arranged in the circumference of the milling cutter. The cutting edge 2-1 of the high-efficiency chip milling cutter has an unequal structure in the circumferential direction. On the end face of the high-efficiency chip milling cutter, the difference between the maximum value and the minimum value of the angle between the end edges 2-3 of two adjacent cutting edges 2-1 is 3.5° to 9°, and the angles are not equal. The above-mentioned unequal cutting edge design can effectively Reduce the vibration during the chip milling process; at the same time, each cutting edge 2-1 is provided with a plurality of chip grooves 2-4 at intervals along the axial direction, and the chip grooves 2-4 on each cutting edge 2-1 are staggered from each other in the axial direction, and the chip grooves 2-4 disconnect the peripheral edges of each cutting edge 2-1 to form a concave and convex sawtooth structure on the surface, and the staggered tooth design of the chip groove is beneficial to the cutting force distribution, and can cut off the chips to form fine debris. The unequal design of the cutting edge is combined with the staggered tooth design of the chip groove, which greatly improves the processing accuracy and processing efficiency. The invention discloses an efficient chip milling cutter which can be used for deep hole expansion processing. The appearance of the cutter is similar to that of a corn milling cutter with a corrugated cutting edge. Compared with the corn milling cutter, the efficient chip milling cutter of the invention has an end edge and a peripheral edge, and has an unequally designed cutting edge and a chip groove with a staggered tooth design. The processing application occasions are wider, and the cutter can be used for deep hole expansion processing, deep square shoulder milling and deep groove milling, etc. The chip size is controllable, and fine chips can be formed, which is convenient for chip cleaning. The cutter is suitable for rough processing and fine processing, and the processing surface roughness Ra≤0.8.

[0034] For the above-mentioned unequally divided design of the cutting edge, preferably, at least one pair of the angle values ​​between the end edges 2-3 of two adjacent cutting edges 2-1 are decimals, such as at least one pair of the angles are "half a degree" angles. Experiments have shown that the use of this unequally divided design makes the cutting vibration frequencies of each cutting edge different, further reducing the resonance of each cutting edge during the cutting process, ensuring the accuracy of the milling process, and being able to perform processing at a higher cutting speed, thereby improving processing efficiency.

[0035] In addition, if Figure 3As shown, in the present invention, the above-mentioned chip groove 2-4 is opened on the cutting edge 2-1 along the circumferential direction of the high-efficiency chip milling cutter, that is, the chip groove 2-4 on the cutting edge 2-1 is arc-shaped, and the chip groove 2-4 is perpendicular to the axial direction of the high-efficiency chip milling cutter, and the cross-sectional shape of the chip groove 2-4 is preferably rectangular, which is not only convenient for the processing of the chip groove 2-4, but also more convenient for chip breaking, so that the chips are miniaturized, especially convenient for cleaning chips in deep holes or deep grooves. The blade length dimension L3 between two adjacent chip grooves 2-4 on each cutting edge 2-1 can be determined according to the chip size, and the smaller the blade length dimension L3, the shorter the chip length. The width L4 of the chip groove 2-4 can be designed to be 0.5~1.5mm, and the chip groove 2-4 can be formed by relief grinding.

[0036] In the present invention, the ratio of the length L2 of the cutting portion 2 to the diameter D1 of the cutting portion 2 is greater than or equal to 3, which is particularly suitable for deep hole or deep groove processing with a diameter greater than 3 times. Generally, the ratio of the length L2 of the cutting portion 2 to the diameter D1 of the cutting portion 2 is preferably designed to be 5 to 8 times. Figure 2 As shown, the end of each cutting edge 2-1 has a front chamfer 2-5, and the front chamfer 2-5 is 45 degrees. The peripheral edge of the cutting edge 2-1 adopts a double back angle design, and the double back angle is 12 degrees to 24 degrees; the back angle of the end edge 2-3 of the cutting edge 2-1 is 10 degrees to 23 degrees.

[0037] The present invention will be further described below in conjunction with the embodiments.

[0038] Example

[0039] This embodiment uses Figures 1 to 4 Taking the four-edge high-efficiency chip milling cutter shown as an example, the design principle of a high-efficiency chip milling cutter that can be used for deep hole expansion processing of the present invention is further explained. In this embodiment, the high-efficiency chip milling cutter includes a handle 1 and a cutting portion 2 integrally arranged at the front of the handle 1, the cutting portion 2 has four circumferentially distributed spiral cutting edges 2-1, and a spiral groove 2-2 for chip removal is provided between two adjacent cutting edges 2-1, each cutting edge 2-1 has an end edge 2-3 arranged on the end face of the milling cutter and a peripheral edge arranged around the milling cutter, and both the end edge 2-3 and the peripheral edge have a back angle. Unlike the existing milling cutters, the cutting edge 2-1 of the high-efficiency chip milling cutter has an unequal structure in the circumferential direction, and the unequal structure of the cutting edge 2-1 is designed as follows: on the end face of the high-efficiency chip milling cutter, the difference between the maximum and minimum values ​​of the angle between the end edges 2-3 of two adjacent cutting edges 2-1 is 3.5° to 9°, and each angle is not equal. Furthermore, at least one pair of the angle values ​​between the end edges 2-3 of two adjacent cutting edges 2-1 are decimals, such as at least one pair of the angles are angles of "half a degree", such as Figure 4As shown, among the four cutting edges 2-1, the angles between two adjacent cutting edges 2-1 are 91°, 93°, 88.5° and 87.5° respectively, two of which have an angle of 0.5°, and the difference between the maximum and minimum angles is 5.5°. Experiments show that the unequal design makes the cutting vibration frequencies of each cutting edge 2-1 different, further reducing the resonance of each cutting edge during the cutting process, ensuring the accuracy of milling processing, and being able to perform processing at a higher cutting speed, thereby improving processing efficiency. On the basis of the unequal design of the cutting edge 2-1, each cutting edge 2-1 also has a chip groove 2-4 with a staggered tooth design. The chip grooves 2-4 on each cutting edge 2-1 are staggered from each other in the axial direction. The chip grooves 2-4 break the peripheral edges of each cutting edge 2-1. During processing, the chip grooves 2-4 break the chips by milling the peripheral edge length to form fine debris. In addition, the staggered tooth design of the chip grooves 2-4 is conducive to cutting force distribution, reducing cutting resistance, facilitating the improvement of processing efficiency, and enabling one-time hole forming of deep holes. In addition, in the above-mentioned unequal design, the helix angles corresponding to the cutting edge 2-1 can also be designed to be inconsistent. In this embodiment, the helix angles of the two spaced cutting edges 2-1 are equal, and the helix angles can be 35° and 36° respectively, that is, the helix angles of the four cutting edges 2-1 are 35°, 36°, 35° and 36° respectively.

[0040] See also Figure 1 , Figure 2 and Figure 3 As shown, in this embodiment, the above-mentioned chip groove 2-4 is opened on the cutting edge 2-1 along the circumferential direction of the high-efficiency chip milling cutter, that is, the chip groove 2-4 on the cutting edge 2-1 is arc-shaped, and the chip groove 2-4 is perpendicular to the axial direction of the high-efficiency chip milling cutter, and the cross-sectional shape of the chip groove 2-4 is preferably rectangular, which is not only convenient for the processing of the chip groove 2-4, but also more convenient for chip breaking, so that the chips are miniaturized, especially convenient for cleaning chips in deep holes or deep grooves. The blade length dimension L3 between two adjacent chip grooves 2-4 on each cutting edge 2-1 can be determined according to the chip size. The smaller the blade length dimension L3, the shorter the chip length. For example, the blade length dimension L3 between two adjacent chip grooves 2-4 can be designed to be 3.5mm, and the width L4 of the chip groove 2-4 can be designed to be 1mm, forming a concave-convex sawtooth structure on the circumferential edge of the cutting edge 2-1. The four-edge high-efficiency chip milling cutter of this embodiment is particularly suitable for deep hole or deep groove processing, so the ratio of the length L2 of the cutting portion 2 to the diameter D1 of the cutting portion 2 is generally designed to be greater than or equal to 3, and preferably the ratio of the length L2 of the cutting portion 2 to the diameter D1 of the cutting portion 2 is designed to be 5 to 8 times. In order to improve the strength of the cutting portion 2, the core thickness diameter D2 of the cutting portion 2 is preferably designed to be 0.6 times the diameter D1 of the cutting portion 2. Figure 2As shown, the end of each cutting edge 2-1 has a front chamfer 2-5, and the front chamfer 2-5 is preferably 0.1mm×45°. The peripheral edge of the cutting edge 2-1 adopts a double clearance angle design, and the double clearance angle is preferably 12° to 24°, and the angle of the second peripheral edge clearance angle is greater than the angle of the first peripheral edge clearance angle; the clearance angle of the end edge 2-3 of the cutting edge 2-1 is preferably 10° to 23°.

[0041] The present invention discloses an efficient chip milling cutter which can be used for deep hole expansion processing. The invention adopts an unequal structural design, and the difference between the maximum and minimum angles between the end edges of two adjacent cutting edges is 3.5° to 9°, and a plurality of chip grooves are arranged at intervals along the axial direction on each cutting edge, and the chip grooves on each cutting edge are staggered from each other in the axial direction. The unequal design combined with the staggered tooth design of the chip grooves effectively reduces the vibration during the processing of the chip milling cutter, is beneficial to the cutting force, and improves the processing accuracy and efficiency. The milling cutter can be used for deep hole expansion processing, deep square shoulder milling and deep groove milling, etc., and the chip size is controllable, and fine chips can be formed, which is convenient for chip cleaning, and the processing of parts with special requirements for chip formation is more perfect.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0043] The present invention and its embodiments are described schematically above, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and creatively designs a structure and an embodiment similar to the technical solution without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A high-efficiency chip-splitting milling cutter for deep hole enlarging processing, comprising a shank (1) and a cutting portion (2) arranged at the front of the shank (1), the cutting portion (2) having 4 to 12 spiral cutting edges (2-1) distributed in the circumferential direction, a spiral groove (2-2) being provided between two adjacent cutting edges (2-1), each cutting edge (2-1) having an end edge (2-3) arranged on the end face of the milling cutter and a peripheral edge arranged in the circumferential direction of the milling cutter, characterized in that: The cutting edge (2-1) of the high-efficiency chip-splitting milling cutter has an unequally divided structure in the circumferential direction; on the end face of the high-efficiency chip-splitting milling cutter, the difference between the maximum and minimum values ​​of the angle between the end edges (2-3) of two adjacent cutting edges (2-1) is 3.5° to 9°; each cutting edge (2-1) is provided with a plurality of chip-splitting grooves (2-4) at intervals along the axial direction, and the chip-splitting grooves (2-4) on each cutting edge (2-1) are mutually staggered in the axial direction; the ratio of the length L2 of the cutting portion (2) to the diameter D1 of the cutting portion (2) is greater than or equal to 3, and the circumferential edge of the cutting edge (2-1) adopts a double back angle design.

2. The high-efficiency chip-splitting milling cutter for deep hole expansion processing according to claim 1, characterized in that: At least one pair of values ​​of the angles between the end edges (2-3) of two adjacent cutting edges (2-1) is a decimal.

3. A high-efficiency chip-splitting milling cutter for deep hole expansion processing according to claim 1 or 2, characterized in that: The chip dividing groove (2-4) is opened on the cutting edge (2-1) along the circumferential direction of the high-efficiency chip dividing milling cutter.

4. The high-efficiency chip-splitting milling cutter for deep hole expansion processing according to claim 3, characterized in that: The cross-sectional shape of the chip dividing groove (2-4) is rectangular.

5. The high-efficiency chip-splitting milling cutter for deep hole expansion processing according to claim 4, characterized in that: The blade length L3 between two adjacent chip grooves (2-4) on each cutting edge (2-1) is determined according to the chip size.

6. The high-efficiency chip-splitting milling cutter for deep hole expansion processing according to claim 5, characterized in that: The width L4 of the chip dividing groove (2-4) is 0.5-1.5 mm.

7. The high-efficiency chip-splitting milling cutter for deep hole expansion processing according to claim 6, characterized in that: The number of cutting edges of the cutting portion (2) is determined according to the diameter D1 of the cutting portion (2); when the diameter D1 of the cutting portion (2) is 6 to 12 mm, the cutting portion (2) has 4 to 5 cutting edges (2-1); when the diameter D1 of the cutting portion (2) is greater than 12 mm, the cutting portion (2) has 6 to 12 cutting edges (2-1).

8. The high-efficiency chip-splitting milling cutter for deep hole expansion processing according to claim 7, characterized in that: The end of each cutting edge (2-1) has a front chamfer (2-5), and the front chamfer (2-5) is 45°.

9. The high-efficiency chip-splitting milling cutter for deep hole expansion processing according to claim 8, characterized in that: The double clearance angle of the peripheral edge of the cutting edge (2-1) is 12° to 24°; the clearance angle of the end edge (2-3) of the cutting edge (2-1) is 10° to 23°.

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