High-precision ball-end mill

Abstract

The application discloses a high-precision ball head milling cutter, which comprises a cutting blade, a cutter bar and a locking bolt. The cutting blade comprises an upper surface, a lower surface, a front peripheral surface, a rear peripheral surface, a bolt through hole, a first main cutting edge and a second main cutting edge. The upper surface comprises a first upper plane, a first upper inclined surface and a second upper plane which are sequentially connected. The lower surface comprises a first lower plane, a second lower plane, a first lower inclined surface and a second lower inclined surface. A bolt counterbore is penetrated through a cutter groove of the cutter bar, and two matching surfaces of the cutter groove are respectively provided with boss structures. The locking bolt is used for threadedly fixing the cutting blade and the cutter bar. The cutting blade can improve the assembly precision and stability of the cutting blade and the cutter bar through the limiting between the second upper plane, the second lower plane, the first upper inclined surface and the first lower inclined surface and the cutter groove, and the cutting blade can be installed with the cutter bar in a correct assembly direction through the interference of the first lower plane and the second lower inclined surface.

Description

Technical Field

[0001] The invention belongs to the field of metal cutting and processing, in particular to a high-precision ball-end milling cutter. Background Art

[0002] In the field of metal processing using CNC tools, milling cutters typically use a structural layout with more than two teeth. In theory, metal processing is a process in which each tooth of a milling cutter repeatedly participates in cutting. The machining accuracy of the workpiece is proportional to the overlap of the blade profiles of each tooth. This means that the higher the overlap of the blade profiles, the higher the precision of the workpiece; the lower the overlap of the blade profiles, the more unstable the cutting process of the tool, which can easily cause tool breakage and substandard workpiece precision. Before using the tool, the actual inspection is the overall accuracy of the blade installed on the tool shank. The better the overlap of the two blades, the higher the overall assembly accuracy of the tool. However, most users install the blades rather haphazardly, and the cutting blade cannot be completely and accurately installed in the tool groove, which will have a certain negative impact on the overall accuracy of the tool.

[0003] Patent publication number CN102325620A discloses a cutting tool and a cutting tool including the same. The cutting tool is fixed to the tool holder by the asymmetric first bevel and second bevel on the rear side of the cutting tool respectively contacting the first contact surface and second contact surface in the concave cavity at the front end of the tool holder. The rear side portion of the cutting tool forms an asymmetric "V"-shaped structure to decompose the force applied to the fixing bolt, thereby preventing damage to the fixing bolt and firmly fixing the cutting tool to the tool holder.

[0004] In this solution, the cutting tool is installed by sliding the first bevel until the second bevel contacts the second contact surface while the fixing bolt applies rotational force. This solution can achieve a strong and stable joint structure, but it ignores the impact that the cutting tool's near-radial sliding installation process has on the overall precision of the cutting tool. During assembly, the structure within the tool holder's front end cavity is difficult to detect. If the cutting tool is installed in the tool holder groove in the opposite direction (upper and lower surfaces are opposite), it may be mistakenly forced to install. Even if it is discovered and reinstalled, this will inevitably reduce the tool installation efficiency. Summary of the Invention

[0005] The object of the present invention is to provide a high-precision ball-end milling cutter to solve the problems raised in the above-mentioned prior art.

[0006] A high-precision ball end milling cutter is provided, comprising:

[0007] The cutting blade comprises an upper surface, a lower surface, a front peripheral surface and a rear peripheral surface, the upper surface and the lower surface are connected and transitioned by the front peripheral surface and the rear peripheral surface, a bolt through-hole is passed through the upper surface and the lower surface, a first main cutting edge and a second main cutting edge are formed on both sides of the front peripheral surface, the upper surface comprises a first upper plane, a first upper inclined surface and a second upper plane connected in sequence, the second upper plane is formed by being recessed inwardly relative to the first upper plane and adjacent to the second main cutting edge, the lower surface comprises a first lower plane, a second lower plane, a first lower inclined surface and a second lower inclined surface, the second lower plane is formed by being recessed inwardly relative to the first lower plane and connected and transitioned between the first lower plane and the second lower inclined surface, and the second lower plane is adjacent to the first main cutting edge;

[0008] A tool rod, one end of which has a tool groove for clamping a cutting blade, the tool groove is penetrated by a bolt countersunk hole, and two mating surfaces of the tool groove are respectively provided with a boss structure mating with the second upper plane and the second lower plane;

[0009] A locking bolt is used to be threadedly connected with the bolt through hole and the bolt countersunk hole in sequence to fix the cutting blade and the tool rod.

[0010] As a further embodiment of the present invention: the intersection lines between the first lower inclined surface and the second lower inclined surface and the second lower plane respectively form an angle of 120° to 150°, the intersection lines between the first lower inclined surface and the second lower inclined surface and the first lower plane respectively form an angle of 120° to 150°, and the intersection line between the first upper inclined surface and the first upper plane and the intersection line between the first upper inclined surface and the second upper plane are both right angles.

[0011] As a further embodiment of the present invention: an included angle of α degrees is formed between the first upper inclined surface and the second upper plane, and the angle α is 105° to 150°.

[0012] As a further embodiment of the present invention: an angle of γ degrees is formed between the first lower inclined surface and the second lower plane, and the γ angle is 105°~150°; an angle of θ degrees is formed between the second lower inclined surface and the second lower plane, and the θ angle is 105°~150°.

[0013] As a further embodiment of the present invention: the angle formed between the first upper inclined surface and the second upper plane, the angle formed between the first lower inclined surface and the second lower plane, and the angle formed between the second lower inclined surface and the second lower plane are all the same.

[0014] As a further embodiment of the present invention: the first main cutting edge and the second main cutting edge extend to an end different from the rear peripheral surface and intersect to form a cutting tip, the extension line of the cutting blade passing through the cutting tip and parallel to the central axis of the shank is the central axis of the cutting blade, the central axis of the bolt through hole is perpendicular to the central axis of the cutting blade, a first intersection line is formed between the first upper inclined surface and the first upper plane, the first intersection line and the central axis of the cutting blade form two projection lines on the radial plane of the central axis of the bolt through hole, an angle of β degrees is formed between the two projection lines, and the β angle is 15°~45°.

[0015] As a further embodiment of the present invention: a second intersection line is formed between the first lower inclined surface and the first lower plane, and projection lines formed by the second intersection line and the first intersection line on the radial plane of the central axis of the bolt through hole are parallel to each other.

[0016] As a further embodiment of the present invention: a third intersection line is formed between the second lower inclined surface and the first lower plane, and the third intersection line is rotationally symmetrical with the first intersection line around the central axis of the cutting insert.

[0017] As a further embodiment of the present invention: the knife groove includes an upper clamping surface, a lower clamping surface and an end clamping surface, the upper clamping surface is provided with an upper boss that fits with the groove structure formed by the second upper plane and the first upper inclined surface, and the lower clamping surface is provided with a lower boss that fits with the groove structure formed by the second lower plane, the first lower inclined surface and the second lower inclined surface.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The clamping accuracy of the cutting blade will directly affect the overall accuracy of the ball end mill. The clamping process of the cutting blade is divided into two steps: pre-installation and locking. Since the second upper plane and the second lower plane, as well as the first upper bevel and the first lower bevel are arranged left and right and upside down on the cutting blade, during the pre-installation process, the first upper bevel and the first lower bevel are respectively limited by the groove, which can guide the cutting blade to a relatively correct installation position, prompting the center of rotation of the cutting blade to approach the center of rotation of the tool shank, eliminating the early impact on the pre-positioning accuracy of the cutting blade. During the locking process, the cutting blade approaches the bottom surface of the groove and is subject to the friction of the locking bolt, which tends to cause relative rotation. However, the resistance provided by the first upper bevel and the first lower bevel can offset the tendency of relative rotation.

[0020] 2. Before the cutting blade is replaced, the general practice is to change the tool outside the machine, that is, to remove the ball end mill from the machine tool, reinstall the new blade, and reinstall it on the machine tool spindle after it is tested and qualified on the instrument. Repeated installation will not only cause a loss in the overall accuracy of the ball end mill, but the machine tool also needs to be re-calibrated, which adds additional time costs. In the technical solution of the present invention, tool change is realized in the machine, and the cutting blade will tend to move vertically downward under the action of gravity. At this time, the first upper bevel and the first lower bevel will decompose the gravity exerted on the cutting blade, and the decomposed force perpendicular to the two bevels will press the cutting blade into the tool groove. With the cooperation of the pre-installation accuracy, the risk of the cutting blade falling during the disassembly and clamping process is reduced, the reuse rate of the blade is improved, and it is more conducive to realizing rapid tool change in the machine.

[0021] 3. A single-piece mounted ball-end milling cutter has two cutting edges, a first main cutting edge and a second main cutting edge. In order to achieve higher outer diameter accuracy, the manufacturing of the cutting blade edge shape is more economical and the common practice is to use the tool bar as a machine tool fixture for integrated peripheral grinding. During actual clamping, when the orientation of the cutting blade mounting surface and the tool bar during installation is consistent with the orientation of the cutting blade and the tool bar during on-machine grinding, the rotational overlap of the two edges is good and the blade accuracy can generally be maintained; when the orientation of the cutting blade mounting surface is opposite to the orientation during on-machine grinding (the upper and lower surfaces are reversed), the possibility of deviation in the rotational overlap of the two edges will increase. In this technical solution, when the cutting blade is installed in the opposite direction, the second lower plane and the second lower bevel will interfere with the boss structure on the tool groove, preventing the cutting blade from being installed in the opposite direction, and restricting the installation of the cutting blade to be completed in accordance with the original grinding assembly rules, so that the loss of rotational overlap accuracy of the two edges can be small. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present drawings or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present drawings. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0023] Figure 1 FIG. A is a perspective view of a ball-end insert provided by the present invention;

[0024] Figure 2 FIG. B is a perspective view of a ball-end insert provided by the present invention;

[0025] Figure 3 FIG. A is a top view of a ball-end insert provided by the present invention;

[0026] Figure 4 FIG. B is a top view of the ball-end insert provided by the present invention;

[0027] Figure 5 is a side view of the ball-end blade provided by the present invention;

[0028] Figure 6 This is a front view of the ball-end blade provided by the present invention;

[0029] Figure 7 yes Figure 3 A cross-sectional view of the middle blade at position E;

[0030] Figure 8 yes Figure 4 A cross-sectional view of the middle blade G position;

[0031] Figure 9 yes Figure 4 A cross-sectional view of the middle blade F position;

[0032] Figure 10 This is an exploded view of the structure of the ball end mill provided by the present invention;

[0033] Figure 11 is a side view of the knife bar provided by the present invention;

[0034] Figure 12 This is a structural perspective view of the knife bar provided by the present invention;

[0035] Figure 13 This is a perspective view of the forward installation of the ball end mill provided by the present invention;

[0036] Figure 14 It is a perspective view of the reverse installation of the ball end mill provided by the present invention.

[0037] In the figure: 1. cutting blade; 2. locking bolt; 3. tool holder; 4. upper surface; 5. lower surface; 6. rear peripheral surface; 7. first main cutting edge; 8. second main cutting edge; 9. bolt through hole; 10. tool tip; 11. front peripheral surface; 12. first upper plane; 13. first upper inclined surface; 14. second upper plane; 16. upper depression; 17. first intersection line; 18. second intersection line; 19. third intersection line; 22. first lower plane; 23. first lower inclined surface; 24. second lower plane; 25. second lower inclined surface; 26. lower depression; 30. tool groove; 31. upper clamping surface; 32. lower clamping surface; 33. end clamping surface; 34. bolt countersunk hole; 41. upper boss; 42. lower boss; 51. first upper clamping inclined surface; 52. first lower clamping inclined surface; 53. second lower clamping inclined surface. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0039] Obviously, the drawings described below are merely examples or embodiments of the present invention. Those skilled in the art can apply the present invention to other similar scenarios based on these drawings without inventive effort. Furthermore, it is understood that while the effort involved in such a development process may be complex and lengthy, for those skilled in the art related to the disclosure of the present invention, any design, manufacturing, or production changes based on the technical content disclosed in the present invention are merely conventional technical means and should not be construed as an inadequacy of the disclosure of the present invention.

[0040] However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of substantially identical structures may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Furthermore, the drawings and the following description are provided to facilitate a thorough understanding of the present invention by those skilled in the art and are not intended to limit the subject matter recited in the claims.

[0041] See also Figures 1-14As shown, the high-precision ball-end mill in the embodiment of the application comprises a cutting blade 1, a cutter bar 3 and a locking bolt 2. The cutting blade 1 comprises an upper surface 4, a lower surface 5, a front peripheral surface 11 and a rear peripheral surface 6, the upper surface 4 and the lower surface 5 are connected and transitioned through the front peripheral surface 11 and the rear peripheral surface 6, the screw hole 9 is through the upper surface 4 and the lower surface 5, the first main cutting edge 7 and the second main cutting edge 8 are respectively formed on the two sides of the front peripheral surface 11, the upper surface 4 comprises a first upper plane 12, a first upper inclined surface 13 and a second upper plane 14 connected in sequence, the second upper plane 14 is recessed inward relative to the first upper plane 12 and is adjacent to the second main cutting edge 8, the lower surface 5 comprises a first lower plane 22, a second lower plane 24, a first lower inclined surface 23 and a second lower inclined surface 25, the second lower plane 24 is recessed inward relative to the first lower plane 22 and is connected and transitioned through the first lower inclined surface 23 and the second lower inclined surface 25 between the first lower plane 22, and the second lower plane 24 is adjacent to the first main cutting edge 7. The cutter bar 3 has a cutter groove 30 at one end for clamping the cutting blade 1, the screw counterbore 34 is through the cutter groove 30, and the two matching surfaces of the cutter groove 30 are respectively provided with the boss structure matched with the second upper plane 14 and the second lower plane 24. The locking bolt 2 is used for threadedly connecting the screw hole 9 and the screw counterbore 34 in sequence to fix the cutting blade 1 and the cutter bar 3.

[0042] The cutting blade 1 is a hard alloy product, which is made into a blank through a powder metallurgy process and is obtained as a finished product through a deep processing procedure. The deep processing procedure is specifically that the blade in the form of a blank is clamped by the cutter bar 3 as a machine tool clamp and is ground on a grinding machine to process each part structure on the cutting blade 1, including the second upper plane 14 and the second lower plane 24 arranged in opposite directions in the up-down and two-side directions respectively. The second upper plane 14 is limited between the first upper inclined surface 13 and the second main cutting edge 8, and the second lower plane 24 is limited between the first lower inclined surface 23, the second lower inclined surface 25 and the first main cutting edge 7.

[0043] Specifically, refer to Figure 3 、 Figure 4 、 Figure 10 、 Figure 13 、 Figure 14As shown, the intersection lines of the first lower bevel 23 and the second lower bevel 25 with the second lower plane 24 form an angle of 120° to 150°, and the intersection lines of the first lower bevel 23 and the second lower bevel 25 with the first lower plane 22 form an angle of 120° to 150°. The intersection lines of the first upper bevel 13 and the first upper plane 12 and the intersection lines of the first upper bevel 13 and the second upper plane 14 are both straight angles. The second upper plane 14 and the second lower plane 24 have different groove structures to ensure that the assembly direction between the cutting blade 1 and the tool holder 3 when the ball end mill is in use is the same as the assembly direction when the cutting blade 1 is assembled on the tool holder 3 for grinding (due to the influence of processing accuracy, reverse installation may cause a large offset between the rotation axis of the cutting blade 1 and the rotation axis of the tool holder 3). This avoids the situation where the rotation overlap accuracy of the first main cutting edge 7 and the second main cutting edge 8 is reduced due to reverse installation.

[0044] See also Figures 10-12 As shown, the tool groove 30 includes an upper clamping surface 31, a lower clamping surface 32 and an end clamping surface 33. The upper clamping surface 31 is provided with an upper boss 41 that fits with the groove structure formed by the second upper plane 14 and the first upper inclined surface 13. The lower clamping surface 32 is provided with a lower boss 42 that fits with the groove structure formed by the second lower plane 24, the first lower inclined surface 23 and the second lower inclined surface 25. The upper boss 41 and the lower boss 42 can limit the axial displacement, radial displacement and circumferential displacement of the cutting blade 1, which can improve the cutting stability of the ball end mill and the surface processing quality of the workpiece. The end clamping surface 33 is perpendicular to the rotation center B of the tool arbor 3 and is used to receive the rear circumference 6 of the cutting blade 1 to provide support for the rear circumference 6. The bolt countersunk hole 34 is used to place the locking bolt 2. The bolt countersunk hole 34 passes through the tool arbor 3 and is perpendicular to the upper clamping surface 31 and the lower clamping surface 32.

[0045] See also Figure 5 and Figure 6As shown, the first upper plane 12 and the first lower plane 22 are surface-ground using a double-end surface grinding machine. They are used to cooperate with the upper clamping surface 31 and the lower clamping surface 32 of the tool slot 30, respectively, to improve the normal positioning accuracy of the cutting insert 1 within the tool slot 30. The front peripheral surface 11 includes a first main cutting edge 7, a second main cutting edge 8, and a cutting tip 10 formed by the two main cutting edges extending to an end different from the rear peripheral surface 6 and intersecting. The central axis A of the cutting insert 1 is defined as the extension line of the cutting insert 1 through the cutting tip 10 and parallel to the central axis of the tool shank 3. The first main cutting edge 7 and the second main cutting edge 8 are semicircular in structure and rotationally symmetrical about the central axis A of the cutting insert 1, ensuring high rotational alignment accuracy of the two main cutting edges. The rear peripheral surface 6 is a plane and perpendicular to the first upper plane 12, the first lower plane 22, and the central axis A of the cutting insert 1. The rear peripheral surface 6 is an axial positioning surface used to mate with the end clamping surface 33. The bolt through hole 9 is a straight hole disposed inside the cutting insert 1 , passing through and perpendicular to the first upper plane 12 and the first lower plane 22 .

[0046] See also Figure 3 and Figure 7 As shown, the first upper plane 12 and the second upper plane 14 are transitioned through the first upper bevel 13. In order to make the installation guiding role of the cutting insert 1 in the tool groove 30 more obvious and provide sufficient friction component for the cutting insert 1, the angle α formed by the first upper bevel 13 and the second upper plane 14 is selected to be 105°≤α≤150°, and this solution preferably has α=135°. The first upper plane 12 and the second upper plane 14 are parallel to each other, and the second upper plane 14 is lower in elevation than the first upper plane 12. The second upper plane 14 is limited by the first upper bevel 13 and extends to the rear peripheral surface 6 and the front peripheral surface 11. The second upper plane 14 and the first upper bevel 13 form an upper recess 16 relative to the first upper plane 12. The upper boss 41 and the upper recess 16 are complementary in structure. Preferably, the depth of the upper recess 16 is 1 / 4 of the maximum thickness H of the cutting insert 1. A first intersection line 17 is formed between the first upper inclined surface 13 and the first upper plane 12. The first intersection line 17 and the center axis of the cutting blade 1 form two projection lines on the radial plane of the center axis of the bolt through hole 9. An angle of β degrees is formed between the two projection lines, and 15°≤β≤45° is selected. In this scheme, β=20° is preferred, and the first intersection line 17 cannot pass through the bolt through hole 9.

[0047] See also Figure 4 、 Figure 8 and Figure 9As shown, the first lower plane 22 and the second lower plane 24 transition through the first lower bevel 23 and the second lower bevel 25. Similarly, in order to more effectively guide the cutting insert 1 in the slot 30 and provide sufficient frictional force for the cutting insert 1, the angle γ formed by the first lower bevel 23 and the second lower plane 24 is selected to be 105°≤γ≤150°, and preferably γ=135°; the angle θ formed by the second lower bevel 25 and the second lower plane 24 is selected to be 105°≤θ≤150°, and preferably θ=135°.

[0048] Preferably, the angle α formed between the first upper inclined surface 13 and the second upper plane 14, the angle γ formed between the first lower inclined surface 23 and the second lower plane 24, and the angle θ formed between the second lower inclined surface 25 and the second lower plane 24 are all the same to ensure balanced forces in all directions.

[0049] See also Figure 1 、 Figure 5 、 Figure 12 、 Figure 13 As shown, the first lower plane 22 and the second lower plane 24 are parallel to each other, and the second lower plane 24 is at a lower elevation than the first lower plane 22. The second lower plane 24 is jointly limited by the first lower bevel 23 and the second lower bevel 25, and extends to the rear circumferential surface 6 and the front circumferential surface 11. The second lower plane 24, the first lower bevel 23, and the second lower bevel 25 form a lower recess 26 relative to the first lower plane 22. The lower boss 42 and the lower recess 26 are complementary in structure. Preferably, the depth of the lower recess 26 is 1 / 4 of the maximum thickness H of the cutting insert 1. The first lower plane 22 and the first lower bevel 23 form a second intersection line 18. The projection lines formed by the second intersection line 18 and the first intersection line 17 on the radial plane of the central axis of the bolt through hole 9 are parallel to each other, and the second intersection line 18 cannot pass through the bolt through hole 9, so as to achieve precise limiting and guiding functions during the pre-installation of the cutting insert 1. The first lower plane 22 and the second lower inclined surface 25 form a third intersection line 19, and the third intersection line 19 and the first intersection line 17 are partially rotationally symmetrical around the central axis A of the cutting insert 1, thereby avoiding local stress between the tool groove 30 and the cutting insert 1 when a single main cutting edge of the cutting insert 1 is subjected to force, thereby achieving force balance.

[0050] Specifically, see Figure 2 、 Figure 10 、 Figures 12-13As shown, the upper boss 41 includes a first upper clamping bevel 51, and the lower boss 42 includes a first lower clamping bevel 52 and a second lower clamping bevel 53. The cutting insert 1 is installed by gradually pushing the cutting insert 1 into the tool slot 30 along the direction of the first intersection line 17, using the first upper bevel 13 as a guide. The first upper bevel 13 first and continuously slides in contact with the first upper clamping bevel 51. Subsequently, the first lower bevel 23 contacts and slides relative to the first lower clamping bevel 52 until the second lower bevel 25 is fully aligned with the second lower clamping bevel 53. The pre-installation is considered to be correctly completed. The locking bolt 2 secures the cutting insert 1 in the tool slot 30 through the bolt countersunk hole 34, forming a ball end mill. Once the ball end mill is mounted on the machine tool spindle, cutting can begin.

[0051] It should be noted that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the technical solution of the present invention are all included in the technical scope of the present invention. In addition, without departing from the scope of the present invention, other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A high-precision ball end milling cutter, characterized in that: include: A cutting blade (1) comprises an upper surface (4), a lower surface (5), a front peripheral surface (11) and a rear peripheral surface (6); the upper surface (4) and the lower surface (5) are connected and transitioned via the front peripheral surface (11) and the rear peripheral surface (6); a bolt through hole (9) passes through the upper surface (4) and the lower surface (5); a first main cutting edge (7) and a second main cutting edge (8) are formed on both sides of the front peripheral surface (11); the upper surface (4) comprises a first upper plane (12), a first upper inclined surface (13) and a second upper plane (14) connected in sequence The second upper plane (14) is formed by being recessed inward relative to the first upper plane (12) and is adjacent to the second main cutting edge (8); the lower surface (5) comprises a first lower plane (22), a second lower plane (24), a first lower inclined surface (23) and a second lower inclined surface (25); the second lower plane (24) is formed by being recessed inward relative to the first lower plane (22) and is connected to the first lower plane (22) via the first lower inclined surface (23) and the second lower inclined surface (25); the second lower plane (24) is adjacent to the first main cutting edge (7); A tool rod (3), one end of the tool rod (3) having a tool groove (30) for clamping a cutting blade (1), a bolt countersunk hole (34) passing through the tool groove (30), and two mating surfaces of the tool groove (30) are respectively provided with a boss structure mating with a second upper plane (14) and a second lower plane (24); A locking bolt (2) is used to be threadedly connected to a bolt through hole (9) and a bolt countersunk hole (34) in sequence to fix the cutting blade (1) and the shank (3).

2. A high-precision ball end milling cutter according to claim 1, characterized in that: The intersection lines between the first lower inclined surface (23) and the second lower inclined surface (25) and the second lower plane (24) respectively form an angle of 120° to 150°, the intersection lines between the first lower inclined surface (23) and the second lower inclined surface (25) and the first lower plane (22) respectively form an angle of 120° to 150°, and the intersection line between the first upper inclined surface (13) and the first upper plane (12) and the intersection line between the first upper inclined surface (13) and the second upper plane (14) are both straight angles.

3. The high-precision ball end milling cutter according to claim 1, characterized in that: An included angle of α degrees is formed between the first upper inclined surface (13) and the second upper plane (14), and the angle α is 105° to 150°.

4. The high-precision ball end milling cutter according to claim 1, characterized in that: An included angle of γ degrees is formed between the first lower inclined surface (23) and the second lower plane (24), and the γ angle is 105° to 150°; an included angle of θ degrees is formed between the second lower inclined surface (25) and the second lower plane (24), and the θ angle is 105° to 150°.

5. A high-precision ball end milling cutter according to claim 3 or 4, characterized in that: The angle formed between the first upper inclined surface (13) and the second upper plane (14), the angle formed between the first lower inclined surface (23) and the second lower plane (24), and the angle formed between the second lower inclined surface (25) and the second lower plane (24) are all the same.

6. The high-precision ball end milling cutter according to claim 1, characterized in that: The first main cutting edge (7) and the second main cutting edge (8) extend to an end different from the rear peripheral surface (6) and intersect to form a cutting tip (10), and the extension line of the cutting blade (1) passing through the cutting tip (10) and parallel to the central axis of the shank (3) is the central axis of the cutting blade (1), the central axis of the bolt through hole (9) is perpendicular to the central axis of the cutting blade (1), and a first intersection line (17) is formed between the first upper inclined surface (13) and the first upper plane (12), and the first intersection line (17) and the central axis of the cutting blade (1) form two projection lines on the radial plane of the central axis of the bolt through hole (9), and an angle of β degrees is formed between the two projection lines, and the β angle is 15° to 45°.

7. The high-precision ball end milling cutter according to claim 6, characterized in that: A second intersection line (18) is formed between the first lower inclined surface (23) and the first lower plane (22), and projection lines formed by the second intersection line (18) and the first intersection line (17) on a radial plane of the central axis of the bolt through hole (9) are parallel to each other.

8. The high-precision ball end milling cutter according to claim 6, characterized in that: A third intersection line (19) is formed between the second lower inclined surface (25) and the first lower plane (22), and the third intersection line (19) and the first intersection line (17) are rotationally symmetrical around the central axis of the cutting blade (1).

9. The high-precision ball end milling cutter according to claim 1, characterized in that: The knife groove (30) includes an upper clamping surface (31), a lower clamping surface (32) and an end clamping surface (33); the upper clamping surface (31) is provided with an upper boss (41) that fits with the groove structure formed by the second upper plane (14) and the first upper inclined surface (13); the lower clamping surface (32) is provided with a lower boss (42) that fits with the groove structure formed by the second lower plane (24), the first lower inclined surface (23) and the second lower inclined surface (25).

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