Drilling and milling cutter

Abstract

The embodiment of the utility model provides a drilling and milling cutter which comprises a cutter handle, a cutter blade and a cutter head, the circumferential blade is arranged at one end of the cutter handle and spirally extends around the central axis of the cutter handle, a cutting tip is arranged at the end, deviating from the cutter handle, of the circumferential blade, and the orthographic projection of the cutting tip on the projection plane is overlapped with the orthographic projection of the outer periphery of the cutter handle on the projection plane; wherein the projection plane is perpendicular to the central axis of the knife handle. According to the technical scheme, drilling and milling integrated precision machining of the hole can be completed, so that the use of two tools is reduced, the time for switching the tools is saved, the machining efficiency can be improved, the cost can be reduced, burrs can be avoided, and the surface smoothness quality of the hole can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of tool, and in particular to a drilling and milling tool. Background Art

[0002] In the related art, when processing small, high-precision and burr-free deep holes, it is necessary to first drill the deep holes with a drill, then perform fine processing with a milling cutter, and finally use a chamfering cutter to remove burrs. This process requires frequent tool switching, which reduces processing efficiency and increases tool costs. Utility Model Content

[0003] The embodiments of the present application provide a drilling and milling tool to solve or alleviate one or more technical problems in the prior art.

[0004] As one aspect of an embodiment of the present application, an embodiment of the present application provides a drilling and milling tool, comprising: a shank; a circumferential blade, arranged at one end of the shank, the circumferential blade extending spirally around the central axis of the shank, the end of the circumferential blade facing away from the shank having a cutting tip, the orthographic projection of the cutting tip on the projection plane overlaps with the orthographic projection of the outer peripheral edge of the shank on the projection plane; wherein the projection plane is perpendicular to the central axis of the shank.

[0005] In one embodiment, there are two circumferential blades, and each circumferential blade has a cutting tip at one end facing away from the tool handle; and the maximum distance between the two cutting tips is equal to the diameter of the tool handle.

[0006] In one embodiment, the drilling and milling tool further comprises: a bottom edge connected to the circumferential edge, and the cutting tip is formed by a part of the circumferential edge and the bottom edge.

[0007] In one embodiment, the back angle of the bottom edge is 10° to 15°.

[0008] In one embodiment, the width of the bottom edge is 0.2 mm to 0.4 mm.

[0009] In one embodiment, the rake angle of the circumferential cutting edge is 22° to 28°.

[0010] In one embodiment, the clearance angle of the circumferential cutting edge is 30° to 35°.

[0011] In one embodiment, the drilling and milling tool further includes: a center cutting edge, which is arranged at one end of the cutting tip close to the tool holder, and the center cutting edge defines a recess, and the orthographic projection of the recess on the projection plane overlaps with the orthographic projection of the center axis of the tool holder on the projection plane.

[0012] In one embodiment, the diameter of the tool handle is d, the width of the recess in a direction perpendicular to the central axis is 0.1d-0.15d; and the depth of the recess in a direction parallel to the central axis is 0.08d-0.12d.

[0013] In one embodiment, there are two circumferential blades, a cutting surface is provided between the end of each circumferential blade facing away from the tool handle and the central cutting edge, and the angle between the two cutting surfaces is 86° to 96°.

[0014] The embodiment of the present application adopts the above-mentioned technical solution to complete the integrated precision machining of drilling and milling of holes, thereby reducing the use of two tools and saving the time of switching tools, thereby improving machining efficiency, reducing costs, and avoiding the generation of burrs, thereby improving the surface finish quality of the holes.

[0015] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present application will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0017] Figure 1 A schematic diagram showing the three-dimensional structure of a drilling and milling tool according to an embodiment of the present application is shown;

[0018] Figure 2 Show Figure 1 A top view of the drilling and milling tool shown in ;

[0019] Figure 3 Show Figure 2 The enlarged view of the part A shown in the middle circle;

[0020] Figure 4 Show Figure 1 A side view of the drilling and milling tool shown in;

[0021] Figure 5 Show Figure 4 An enlarged view of the circled section B;

[0022] Figure 6 Show Figure 1 A front view of the drilling and milling tool shown in;

[0023] Figure 7 Show Figure 6 An enlarged view of the circled section C.

[0024] Description of reference numerals:

[0025] 10: drilling and milling tool; 100: tool holder; 200: circumferential edge; 210: cutting tip; 211: first surface; 212: second surface; 213: third surface; 214: fourth surface; 215: fifth surface; 300: bottom edge; 400: center cutting edge; 410: recess. DETAILED DESCRIPTION

[0026] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present application. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0027] Figure 1 FIG. 2 shows a schematic diagram of the three-dimensional structure of a drilling and milling tool according to an embodiment of the present application. Figure 1 As shown, the drilling and milling tool 10 includes a tool handle 100 and a circumferential blade 200. The circumferential blade 200 is arranged at one end of the tool handle 100, and the circumferential blade 200 spirally extends around the central axis of the tool handle 100. The end of the circumferential blade 200 away from the tool handle 100 has a cutting tip 210, and the orthographic projection of the cutting tip 210 on the projection plane overlaps with the orthographic projection of the outer peripheral edge of the tool handle 100 on the projection plane; wherein the projection plane is perpendicular to the central axis of the tool handle 100.

[0028] For the convenience of description, the “orthographic projection of the cutting tip 210 on the projection plane” is referred to as the first projection; and the “orthographic projection of the outer periphery of the tool holder 100 on the projection plane” is referred to as the second projection.

[0029] It should be noted that “overlap” in this application should be understood in a broad sense, meaning that a portion of the first projection overlaps with a portion of the second projection, and another portion of the first projection and another portion of the second projection are independent of each other and do not overlap.

[0030] Exemplarily, the shape of the orthographic projection (i.e., the second projection) of the outer periphery of the handle 100 on the projection plane is a circle. The orthographic projection (i.e., the first projection) of the cutting tip 210 on the projection plane can be an irregular shape. The first projection and the second projection can have two overlapping parts, and the two overlapping parts can be arranged opposite to each other in the diameter direction of the circle.

[0031] Figure 2 Show Figure 1 A top view of the drilling and milling tool 10 shown in FIG. Figure 3 Show Figure 2 Schematically, in combination with Figure 1-Figure 3, the cutting tip 210 can be defined by four faces. Take the four faces as the first face 211, the second face 212, the third face 213 and the fourth face 214 as an example for explanation. The first face 211 is adjacent to the second face 212, and the first face 211 is adjacent to the fourth face 214. The second face 212 is adjacent to the third face 213, and the third face 213 is adjacent to the fourth face 214. Among them, the first face 211 and the fourth face 214 can be planes, and the second face 212 and the third face 213 can be curved surfaces. The cutting tip 210 can have a first edge, a second edge, a third edge and a fourth edge, the first edge is the common edge of the first face 211 and the second face 212, the second edge is the common edge of the first face 211 and the fourth face 214, the third edge is the common edge of the second face 212 and the third face 213, and the fourth edge is the common edge of the third face 213 and the fourth face 214. The first edge and the second edge may be straight lines, and the third edge and the fourth edge may be curved lines. For example, the third edge may be at least a portion of the circumferential edge 200 .

[0032] Exemplarily, the drilling and milling tool 10 may further include a fifth surface 215 connected to the first surface 211. The area of ​​the fifth surface 215 is greater than the area of ​​the first surface 211, and the fifth surface 215 is more inclined than the first surface 211. During the hole processing, the first surface 211 contacts the material of the workpiece first, and the fifth surface 215 contacts the material of the workpiece later. By making the fifth surface 215 more inclined, the fifth surface 215 can play an effective avoidance role, reduce the possibility of chip accumulation during cutting, and facilitate the chips to leave the drilling and milling tool 10 more smoothly, while avoiding overheating of the cutting area, thereby improving cutting efficiency.

[0033] For example, in combination Figure 1-Figure 3 During the process of machining the hole, the drilling and milling tool 10 can rotate clockwise and move forward along the central axis of the tool holder 100. During the rotation and movement of the drilling and milling tool 10, the first edge and the third edge can cut off the material of the workpiece to form a hole. The part of the cutting tip 210 that contacts the workpiece at least forms the inner wall of the hole. Since the orthographic projection of the cutting tip 210 on the projection plane overlaps with the orthographic projection of the outer periphery of the tool holder 100 on the projection plane, the cutting tip 210 can be located at the edge, so that the inner wall of the hole can be machined first, and the material finally removed can fall into blocks without generating fine burrs, so that the drilling and milling tool 10 can be used to process small, precision-required and burr-free deep holes on the surface, such as holes on the middle frame structure of a mobile phone. Among them, the drilling and milling tool 10 can also include a chip groove extending spirally around the central axis of the tool holder 100. Optionally, the tool holder 100 can be integrally formed with the circumferential blade 200 to enhance the structural strength of the entire drilling and milling tool 10.

[0034] In an exemplary embodiment, the circumferential blade 200 may be a common edge of the second surface 212 and the third surface 213, and may be spiral. The front angle β of the circumferential blade 200 is the angle between the second edge and the fourth edge in the fourth surface 214; the back angle θ of the circumferential blade 200 is the angle between the first edge and the second edge in the first surface 211.

[0035] According to the drilling and milling tool 10 of the embodiment of the present application, by making the end of the circumferential blade 200 facing away from the shank 100 have a cutting tip 210, and the orthographic projection of the cutting tip 210 on the projection plane overlaps with the orthographic projection of the outer peripheral edge of the shank 100 on the projection plane, on the one hand, the integrated precision machining of drilling and milling of the hole can be completed, thereby reducing the use of two tools and saving the time for switching tools, thereby improving the machining efficiency, for example: the machining efficiency can be improved by 60%, and the cost can be reduced; on the other hand, the generation of burrs can be avoided, thereby improving the surface finish quality of the hole.

[0036] In one embodiment, Figure 1-Figure 3 As shown, there can be two circumferential blades 200, and each circumferential blade 200 has a cutting tip 210 at one end facing away from the tool holder 100; the maximum distance between the two cutting tips 210 is equal to the diameter of the tool holder 100, that is, the two cutting tips 210 can be arranged opposite to each other in the radial direction of the tool holder 100. Therefore, through the above arrangement, the two cutting tips 210 can disperse the cutting force and reduce the load of each cutting tip 210, thereby slowing down the wear rate of the drilling and milling tool 10. In addition, the two cutting tips 210 can increase the stability of the drilling and milling tool 10, reduce the imbalance and vibration caused by a single cutting tip, and reduce the possibility of deformation of the drilling and milling tool 10, thereby extending the service life of the drilling and milling tool 10.

[0037] Figure 4 Show Figure 1 A side view of the drilling and milling tool 10 shown in FIG. Figure 5 Show Figure 4 In one embodiment, refer to Figure 1 , Figure 4 and Figure 5 The drilling and milling tool 10 may further include a bottom blade 300, wherein the bottom blade 300 is connected to the circumferential blade 200, and the cutting tip 210 is formed by a portion of the circumferential blade 200 and the bottom blade 300. The bottom blade 300 may be understood as a cutting blade located at the bottom of the tool (i.e., the side away from the shank 100), which is used to provide bottom support and cutting functions during processing. The bottom blade is responsible for cutting the surface of the workpiece so that the workpiece obtains the desired shape. During the milling operation, the bottom blade contacts the surface of the workpiece to control the cutting depth and cutting direction, while ensuring the stability and accuracy of the cutting process. The structure of the bottom blade may be adjusted according to different processing requirements to meet the requirements of different materials and processing conditions. Exemplarily, the bottom blade 300 may be the first edge mentioned above.

[0038] In this embodiment, by providing a bottom blade 300 connected to the circumferential blade 200, the stability of the drilling and milling tool 10 can be effectively increased, and the possibility of vibration and deformation of the drilling and milling tool 10 can be reduced, thereby improving the processing accuracy and surface quality. Moreover, the provision of the bottom blade 300 can improve the discharge of chips, reduce cutting resistance, and thus improve cutting efficiency. In addition, the bottom blade 300 can reduce the load of the cutting tip 210 and disperse the cutting force, thereby slowing down the wear rate of the drilling and milling tool 10 and extending the service life of the drilling and milling tool 10.

[0039] In some embodiments, the back angle α of the bottom blade 300 can be 10° to 15° (including the end value). Among them, the back angle of the bottom blade 300 can be understood as the angle between the rear of the bottom blade 300 and the surface of the workpiece. Specifically, for example, when the back angle α of the bottom blade 300 is less than 10°, the back angle of the bottom blade 300 is too small, which may cause difficulty in chip discharge during cutting. Chips accumulate between the drilling and milling tool 10 and the workpiece, increasing the cutting force and may cause overheating in the cutting area. This will reduce cutting efficiency, increase the wear of the drilling and milling tool 10, and may result in poor quality of the machined surface. Moreover, a too small back angle of the bottom blade 300 will increase the contact area between the drilling and milling tool 10 and the workpiece, increase friction during cutting, and lead to the accumulation of cutting heat. For materials that are easy to soften, such as plastics, excessive cutting heat may cause the material to melt, stick to the tool or the workpiece surface, resulting in reduced processing quality or even tool damage. In addition, too small a back angle of the bottom blade 300 will increase the operating temperature and friction of the drilling and milling tool 10, resulting in a shortened life of the drilling and milling tool 10, increasing production costs and the frequency of replacing the drilling and milling tool 10. When the back angle α of the bottom blade 300 is greater than 15°, the friction between the drilling and milling tool 10 and the workpiece will increase, resulting in an increase in cutting force. This will increase energy consumption during the cutting process and may increase the load on the machine tool, affecting processing efficiency. Moreover, an excessively large back angle will adversely affect the cutting edge of the drilling and milling tool 10, which may result in unstable cutting, vibration or jitter, thereby affecting the quality of the machined surface.

[0040] Therefore, by setting the back angle α of the bottom blade 300 to 10° to 15°, the bottom blade 300 can more easily discharge the chips from the cutting area during cutting, thereby reducing the possibility of chip accumulation during cutting. Especially for materials such as plastics, the chips generated during cutting tend to adhere to the tool, affecting the cutting efficiency and tool life. A reasonable back angle can help the chips leave the drilling and milling tool 10 more smoothly. Moreover, it helps to reduce the friction area when the drilling and milling tool 10 contacts the workpiece and reduce the friction heat during the cutting process. In addition, the heat during the cutting process can also be reduced, thereby helping to slow down the wear and damage of the drilling and milling tool 10.

[0041] In one embodiment, the width w1 of the bottom blade 300 can be 0.2 mm to 0.4 mm (including the end values). Specifically, for example, when w1 is less than 0.2 mm, the width of the bottom blade 300 is too small, which may cause the drilling and milling tool 10 to be insufficiently strong, easily break or deform during the cutting process, and fail to provide sufficient support, causing the drilling and milling tool 10 to vibrate excessively during the cutting process, affecting the processing quality, and failing to effectively disperse the heat generated during the cutting process, which may easily lead to local heat concentration and affect the life of the drilling and milling tool 10. When w1 is greater than 0.4 mm, the width of the bottom blade 300 is too large, which will increase the surface area of ​​the drilling and milling tool 10 in contact with the workpiece, exacerbating the wear of the drilling and milling tool 10.

[0042] Therefore, by making the width w1 of the bottom blade 300 0.2 mm to 0.4 mm, the width w1 of the bottom blade 300 is reasonable, which can increase the strength and stability of the drilling and milling tool 10, reduce the vibration and deformation of the drilling and milling tool 10 during the cutting process, and thus extend the service life of the drilling and milling tool 10. Moreover, the bottom blade 300 set in this way can disperse the heat generated during cutting, thereby reducing the concentration of local heat and reducing the wear rate of the drilling and milling tool 10. In addition, the width of the bottom blade 300 is relatively large, so that the drilling and milling tool 10 can be ground multiple times during use, thereby extending the service life of the drilling and milling tool 10 and reducing production costs. In addition, the contact pressure and friction between the drilling and milling tool 10 and the workpiece during the cutting process can also be reduced, thereby reducing the cutting force and reducing the wear of the drilling and milling tool 10.

[0043] In one embodiment, referring to Figure 2 and Figure 3 , the front angle β of the circumferential blade 200 can be 22°~28° (including the end point values). Among them, the front angle of the circumferential blade 200 refers to the angle between the front part of the circumferential blade 200 and the surface of the workpiece. Therefore, by making the front angle β of the circumferential blade 200 22°~28°, when the drilling and milling tool 10 cuts into the workpiece, the setting of β can reduce the contact area between the drilling and milling tool 10 and the workpiece, reduce the friction and resistance during cutting, make it easier for the drilling and milling tool 10 to enter the workpiece, reduce the cutting force during the machining process, and help to reduce the feed force of the circumferential cutting edge, so that the drilling and milling tool 10 can cut into the workpiece more smoothly, prevent the tool from jumping or vibrating, improve the machining efficiency and the quality of the machined surface, and reduce the cutting vibration during the machining process, thereby improving the machining accuracy and surface finish.

[0044] In one embodiment, in combination Figure 1-Figure 3, the clearance angle θ of the circumferential blade 200 can be 30° to 35° (including the end value). The clearance angle of the circumferential blade 200 refers to the angle between the rear of the circumferential blade 200 and the surface of the workpiece. Therefore, by making the clearance angle θ of the circumferential blade 200 30° to 35°, the chips can be made larger, which helps to improve the chip discharge efficiency and reduce the blockage phenomenon during cutting, thereby improving the processing speed and efficiency.

[0045] Figure 6 Show Figure 1 A front view of the drilling and milling tool 10 shown in FIG. Figure 7 Show Figure 6 In one embodiment, as Figure 6 and Figure 7 As shown, the drilling and milling tool 10 may further include a central cutting edge 400, which is disposed at one end of the cutting tip 210 close to the tool handle 100, and the central cutting edge 400 defines a recess 410, and the orthographic projection of the recess 410 on the projection plane overlaps with the orthographic projection of the central axis of the tool handle 100 on the projection plane. For example, the orthographic projection of the central axis of the tool handle 100 on the projection plane may be located within the orthographic projection of the recess 410 on the projection plane. In other words, the central axis of the tool handle 100 passes through the recess 410.

[0046] In this embodiment, the recess 410 can act as a chip groove for accommodating and discharging the chips generated during the cutting process, preventing the chips from accumulating on the drilling and milling tool 10 or the workpiece surface, keeping the processing area clean, reducing friction and wear during the cutting process, and improving processing efficiency and quality.

[0047] In one embodiment, the diameter of the tool handle 100 is d, and the width w2 of the recess 410 in the direction perpendicular to the central axis is 0.1d to 0.15d (including the endpoint value); the depth h of the recess 410 in the direction parallel to the central axis is 0.08d to 0.12d (including the endpoint value). With such a configuration, on the one hand, the width w2 of the recess 410 is of a reasonable size, which can ensure that the central cutting edge 400 has sufficient cutting ability, and can effectively remove chips from the workpiece, reduce blockage and vibration during the cutting process, thereby reducing the wear and damage of the drilling and milling tool 10 and extending the service life of the drilling and milling tool 10; on the other hand, the depth h of the recess 410 is of a reasonable size, which can ensure that the central cutting edge 400 can correctly position and cut the workpiece during the processing process, thereby avoiding the occurrence of the tool stepping on the tool.

[0048] In one embodiment, there are two circumferential blades 200, and a cutting surface is provided between the end of each circumferential blade 200 that faces away from the tool holder 100 and the central cutting edge 400, and the angle γ between the two cutting surfaces is 86° to 96° (including the end value). In this way, the angle γ between the two cutting surfaces is reasonable, which can effectively improve the cutting ability and cutting stability of the central cutting edge 400, thereby improving the cutting efficiency and cutting quality.

[0049] In the description of this specification, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0051] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0052] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0053] The disclosure above provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described above. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numerals and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0054] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A drilling and milling tool, characterized in that: include: Handle; A circumferential blade is provided at one end of the tool handle, the circumferential blade spirally extends around the central axis of the tool handle, the end of the circumferential blade facing away from the tool handle has a cutting tip, and the orthographic projection of the cutting tip on the projection plane overlaps with the orthographic projection of the outer peripheral edge of the tool handle on the projection plane; wherein the projection plane is perpendicular to the central axis of the tool handle; A bottom blade is connected to the circumferential blade, and the cutting tip is formed by a part of the circumferential blade and the bottom blade.

2. The drilling and milling tool according to claim 1, characterized in that: There are two circumferential blades, and each circumferential blade has a cutting tip at one end facing away from the tool handle; the maximum distance between the two cutting tips is equal to the diameter of the tool handle.

3. The drilling and milling tool according to claim 1, characterized in that: The back angle of the bottom blade is 10° to 15°.

4. The drilling and milling tool according to claim 1, characterized in that: The width of the bottom blade is 0.2 mm to 0.4 mm.

5. The drilling and milling tool according to claim 1, characterized in that: The front angle of the circumferential blade is 22° to 28°.

6. The drilling and milling tool according to claim 1, characterized in that: The back angle of the circumferential blade is 30° to 35°.

7. The drilling and milling tool according to claim 1, characterized in that: Also includes: A central cutting edge is arranged at one end of the cutting tip close to the tool handle, wherein the central cutting edge defines a recessed portion, and an orthographic projection of the recessed portion on the projection plane overlaps with an orthographic projection of a central axis of the tool handle on the projection plane.

8. The drilling and milling tool according to claim 7, characterized in that: The diameter of the tool handle is d, the width of the recess in a direction perpendicular to the central axis is 0.1d to 0.15d; the depth of the recess in a direction parallel to the central axis is 0.08d to 0.12d.

9. The drilling and milling tool according to claim 7, characterized in that: There are two circumferential blades, and a cutting surface is arranged between the end of each circumferential blade facing away from the tool handle and the central cutting edge, and the angle between the two cutting surfaces is 86° to 96°.

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