Symmetrical bevel positioning replaceable drill bit

Abstract

The present invention relates to a replaceable drill bit with symmetrical bevel positioning, comprising a drill rod and a replaceable drill tip, wherein a first positioning bevel of the drill tip and a second positioning bevel of the drill tip are arranged at the lower end of the replaceable drill tip, and are centrally symmetrical along a common axis CL, the first positioning bevel of the replaceable drill tip and the second positioning bevel of the drill tip match with two corresponding positioning bevels of a drill rod mounting structure, a first limiting surface and a second limiting surface are arranged below the first mounting surface and the second mounting surface of the replaceable drill tip, and the drill bit presents a dovetail structure which is narrow at the top and wide at the bottom, and a first fastening through hole and a second fastening through hole are arranged in the middle of a first chip removal groove of the drill tip and a second chip removal groove of the drill tip; a mounting structure for mounting the replaceable drill tip is arranged at the upper end of the drill rod, and is a semi-enclosed groove centrally symmetrical with the common axis CL, the groove has a first positioning bevel of the drill rod and a second positioning bevel of the drill rod as positioning surfaces, which match with the first positioning bevel of the drill tip and the second positioning bevel of the drill tip of the replaceable drill tip, and the replaceable drill tip is coaxial with the drill rod; a fastening screw fixes the replaceable drill tip on the drill rod.

Description

Technical Field

[0001] The invention relates to a replaceable drill bit with symmetrical inclined surface positioning, belonging to the technical field of cutting tools. Background Art

[0002] At present, carbide drills have been widely used in hole processing technology, but in large-diameter drilling, the overall carbide drill is expensive; especially in high-speed and high-efficiency drilling, the cost of internally cooled overall carbide drills is even higher, and the replacement drill becomes an inevitable technical path for low-cost processing. The existing disclosed technical solutions have the following shortcomings:

[0003] For example: Patent No. PCT / IL2005 / 000999 discloses "cutting tools, cutting heads and cutting tool assemblies". When used in drilling tools, there is a problem that the receiving part of the shank is too thin, and the clamping force is reduced after multiple replacements of the drill tip, which leads to the failure of the drill bit.

[0004] The Chinese patent with patent application number 201710517688.4 discloses a "high stability self-centering drill tip". The drill tip is installed on the tool bar by rotating and locking with a pin. This installation method is more accurate, but the biggest problem is that the installation part of the tool bar is thin and easily fatigued after multiple clamping. There is a situation where the clamping force is reduced, which leads to the failure of the replaceable drill tip drill.

[0005] The Chinese patent with patent number 201510252190.0 discloses "a drill bit with a replaceable cutter head structure", which is positioned by a pin and fastened by a pin side pressure screw; the problem of a thin structure of the arbor mounting part also exists. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a symmetrical bevel positioning replaceable drill bit.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] The symmetrical bevel positioning replaceable drill bit is characterized by comprising a drill rod, a replaceable drill tip, a first fastening screw, and a second fastening screw, wherein the replaceable drill tip is mounted on the drill rod and has a common common axis CL;

[0009] The replaceable drill tip is a sheet-like structure that is 360° centrally symmetrical about the axis CL, a first drill tip positioning bevel and a second drill tip positioning bevel are provided at the lower end, the first drill tip mounting surface and the second drill tip mounting surface are inclined with the adjacent first drill tip positioning bevel or the adjacent second drill tip positioning bevel, a sheet-like structure of a first limiting surface and a second limiting surface is provided at the lower part of the adjacent first drill tip mounting surface and the second drill tip mounting surface, the first limiting surface and the second limiting surface form a dovetail structure that is narrow at the top and wide at the bottom; a first cutting edge and a second cutting edge are provided that are 360° centrally symmetrically distributed along the axis CL, the first cutting edge and the second cutting edge are extended from the uppermost end of the replaceable drill tip from the central axis CL to both sides The drill tip is provided with a first edge and a second edge on the left and right sides, the first edge and the second edge are parts of the outermost imaginary cylinders of the first cutting edge and the second cutting edge, have a width and are spiral-shaped; adjacent to the first cutting edge and the second cutting edge, with the first edge and the second edge as edges, a first chip groove of the drill tip and a second chip groove of the drill tip are provided, the first chip groove of the drill tip and the second chip groove of the drill tip are the natural extensions of the first cutting edge and the second cutting edge on the replaceable drill tip in a spiral manner with the axis CL as a reference and along the first edge and the second edge; a first fastening through hole and a second fastening through hole are provided in the middle of the first chip groove of the drill tip and the second chip groove of the drill tip respectively;

[0010] The drill rod is a combination of a drill body, a cone guard and a cylindrical straight handle coaxially with a common axis CL, and is provided with a spiral drill rod first chip removal groove and a drill rod second chip removal groove with the axis CL as the symmetry center, and a mounting structure is provided at the upper end, and the mounting structure is a semi-closed groove symmetrical with the common axis CL center, and the lower part of the groove is a drill rod first positioning inclined surface and a drill rod second positioning inclined surface as positioning surfaces; the solid part on both sides of the groove is provided with a first mounting screw hole and a second mounting screw hole above the drill rod first positioning inclined surface and the drill rod second positioning inclined surface, and a first limiting screw hole and a second limiting screw hole are provided below the first mounting screw hole and the second mounting screw hole;

[0011] The first positioning bevel of the drill tip and the second positioning bevel of the drill tip cooperate with the first positioning bevel of the drill rod and the second positioning bevel of the drill rod to make the replaceable drill tip coaxial with the drill rod with a common axis CL; during installation, the limit screw 1 and the limit screw are screwed into the first limiting screw hole and the second limiting screw hole of the drill rod to abut against the first limiting surface and the second limiting surface to prevent the replaceable drill tip from loosening from the drill rod.

[0012] Furthermore, in the above-mentioned symmetrically inclined surface positioning replaceable drill bit, the first positioning inclined surface of the drill tip and the second positioning inclined surface of the drill tip are structurally symmetrical with respect to the center of the common axis CL and are arranged in a spatial V-shape, and the spatial angle is 100° to 140°.

[0013] Furthermore, in the above-mentioned symmetrical bevel positioning replaceable drill bit, the first drill tip mounting surface and the second drill tip mounting surface are inclined with the adjacent first drill tip positioning bevel or the second drill tip positioning bevel, and the included angle is 90° to 100°.

[0014] Furthermore, in the above-mentioned symmetrical bevel positioning replaceable drill bit, the first limiting surface and the second limiting surface form a dovetail structure that is narrow at the top and wide at the bottom, and the dovetail angle is 5° to 20°.

[0015] Furthermore, in the above-mentioned symmetrical bevel positioning replaceable drill bit, the first cutting edge and the second cutting edge are in the shape of a straight line, an arc, or a spatial curve that adapts to the cutting action.

[0016] Furthermore, in the above-mentioned symmetrical bevel positioning replaceable drill bit, the outermost tangent lines of the first edge and the second edge form a helix angle with the axis CL, and the helix angle is 15° to 35°.

[0017] Furthermore, in the above-mentioned symmetrical bevel positioning replaceable drill bit, the width of the first edge and the second edge is 0.05 to 0.1 times the diameter of the replaceable drill tip; the distance between the first edge and the second edge in the direction of the axis CL is the edge length, and the edge length is 0.3 to 1.0 times the diameter of the replaceable drill tip.

[0018] Furthermore, the above-mentioned symmetrical bevel positioning replaceable drill bit, wherein the first chip groove of the drill rod and the second chip groove of the drill rod have a truncation on the cross section perpendicular to the axis CL, and the truncation is composed of four line segments connected in sequence, the starting segment and the ending segment are the first straight line segment and the second straight line segment, and the middle segment is the first circular arc segment and the second circular arc segment.

[0019] Furthermore, in the above-mentioned symmetrically inclined surface positioning replaceable drill bit, the first positioning inclined surface of the drill rod and the second positioning inclined surface of the drill rod are structurally symmetrical with the center of the common axis CL and are arranged in a spatial V-shape, and the V-shaped angle is 100°~140°. When installing the replaceable drill tip, the first positioning inclined surface of the drill tip and the second positioning inclined surface of the drill tip of the replaceable drill tip can be matched to make the replaceable drill tip and the drill rod coaxial with the common axis CL.

[0020] Furthermore, the above-mentioned symmetrical bevel positioning replaceable drill bit, wherein the drill rod is distributed 360° centrally symmetrically along the axis CL, and has at least a first cooling channel and a second cooling channel, the first cooling channel and the second cooling channel are connected to the main cooling channel; the cylindrical straight handle is provided with an internal pipe thread for connecting the cooling liquid circuit, and a side pressure surface is provided on the cylindrical straight handle.

[0021] Compared with the prior art, the present invention has significant advantages and beneficial effects, which are specifically embodied in the following aspects:

[0022] ① The present invention has a unique design and novel structure. The replaceable drill head includes a replaceable drill tip and a drill rod. The lower part of the replaceable drill tip has a symmetrical inclined positioning surface. The upper part of the drill rod is provided with a mounting structure. The groove of the mounting structure has a drill rod positioning inclined surface with the same angle. The positioning structures of the replaceable drill tip and the drill rod have the same spatial angle and can cooperate. After installation, the replaceable drill tip and the drill rod have a common common axis CL, and the replaceable drill tip is stably fixed on the drill rod.

[0023] ② The first chip groove of the replaceable drill tip and the middle of the second chip groove of the drill tip are respectively provided with a first fastening through hole and a second fastening through hole; when installing, the replaceable drill tip is locked by two fastening screws and then abutted by two limit screws to stably fix the replaceable drill tip on the drill rod, and the connection is firm and forms a whole;

[0024] ③ The drill rod and the replaceable drill tip can be installed together through two fastening screws to form a symmetrical bevel positioning replaceable drill head for drilling processing, so that the replaceable drill tip can be easily replaced without disassembling the tool rod during use;

[0025] ④ When working, it is carried out in CCW rotation direction, and the cutting is smooth; the material grade and geometric characteristics of different replaceable drill tips can be selected according to the workpiece material; it has the characteristics of simple structure, accurate positioning, high mechanical strength, reliable installation, and can significantly improve the service life of the replaceable drill tip, with low cost and good economy.

[0026] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by practicing the specific embodiments of the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 : A schematic diagram of the assembly of the present invention;

[0029] Figure 2 : Front view of the replaceable drill tip;

[0030] Figure 3 : Side view of the replaceable drill tip;

[0031] Figure 4 : A three-dimensional schematic diagram of the drill pipe;

[0032] Figure 5 : Partial view of the front assembly of the replaceable drill tip and the drill rod;

[0033] Figure 6 : Partial view of the side assembly of the replaceable drill tip and the drill rod;

[0034] Figure 7 : Figure 5 XX cross-sectional view;

[0035] Figure 8 : Figure 6 TT cross-sectional view;

[0036] Fig. 9 : Schematic diagram of drill pipe with cooling channels;

[0037] Fig.10 : Partial schematic diagram of the drill pipe;

[0038] Fig.11 : Schematic diagram of the installation and application of replaceable drill tips and drill rods. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0040] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, directional terms and order terms are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0041] like Figures 1 to 3 As shown, the symmetrical bevel positioning replaceable drill bit includes a drill rod 100, a replaceable drill tip 200, and a fastening screw 1 400A and a fastening screw 2 400B. The replaceable drill tip 200 is installed on the drill rod 100 and has a common common axis CL;

[0042] The replaceable drill tip 200 is a sheet-like structure that is 360° centrally symmetrical about the axis CL, and is provided with a first drill tip positioning bevel 205A and a second drill tip positioning bevel 205B at the lower end. The first drill tip positioning bevel 205A and the second drill tip positioning bevel 205B are structurally centrally symmetrical about the common axis CL and are arranged in a spatial V-shape, with a spatial angle of 100° to 140°. The first drill tip mounting surface 207A and the second drill tip mounting surface 207B are inclined with the adjacent first drill tip positioning bevel 205A or the second drill tip positioning bevel 205B, with an angle of 90° to 100°.

[0043] The first positioning bevel 205A and the second positioning bevel 205B of the drill tip cooperate with the first positioning bevel 110A and the second positioning bevel 110B of the drill rod, so that the replaceable drill tip 200 is coaxial with the drill rod 100 with the common axis CL; the lower part of the adjacent first mounting surface 207A and the second mounting surface 207B of the drill tip is provided with a sheet structure of a first limiting surface 204A and a second limiting surface 204B, and the first limiting surface 204A and the second limiting surface 204B form a dovetail structure that is narrow at the top and wide at the bottom; the angle of the dovetail structure is designed to be 5° to 20°; during installation, the first limiting screw hole 104A and the second limiting screw hole 104B of the drill rod 100 are screwed into the limiting screw 500A and the limiting screw 500B to abut against the first limiting surface 204B and the second limiting surface 204A to prevent the replaceable drill tip from loosening from the drill rod;

[0044] The first cutting edge 202A and the second cutting edge 202B are arranged symmetrically with respect to the axis CL at 360°, and the first cutting edge 202A and the second cutting edge 202B are in the shape of a straight line, an arc or a space curve adapted to the cutting action, and the first cutting edge 202A and the second cutting edge 202B extend from the center axis CL to the maximum diameters on both sides at the uppermost end of the replaceable drill tip 200; the first edge 201A and the second edge 201B are arranged on the left and right sides, and the first edge 201A and the second edge 201B are part of the outermost imaginary cylinder of the first cutting edge 202A and the second cutting edge 202B, have a width and are spiral-shaped;

[0045] The outermost tangent lines of the first edge 201A and the second edge 201B form a helix angle 220 with the axis CL, and the helix angle 220 is 15° to 35°. The width of the first edge 201A and the second edge 201B is 0.05 to 0.1 times the diameter of the replaceable drill tip 200. The distance between the first edge 201A and the second edge 201B in the direction of the axis CL is the edge length, and the edge length is 0.3 to 1.0 times the diameter of the replaceable drill tip 200.

[0046] Adjacent to the first cutting edge 202A and the second cutting edge 202B, with the first edge 201A and the second edge 201B as edges, a first drill tip chip groove 203A and a second drill tip chip groove 203B are provided, the first drill tip chip groove 203A and the second drill tip chip groove 203B are natural extensions of the first cutting edge 202A and the second cutting edge 202B on the replaceable drill tip 200 in a spiral manner and along the first edge 201A and the second edge 201B with the axis CL as a reference; a first fastening through hole 206A and a second fastening through hole 206B are provided in the middle of the first drill tip chip groove 203A and the second drill tip chip groove 203B, respectively;

[0047] The first fastening through hole 206A and the second fastening through hole 206B are respectively perpendicular to the first mounting surface 207A and the second mounting surface 207B of the drill tip; during installation, the replaceable drill tip 200 is stably fixed on the drill rod 100 by the first fastening screw 400A and the second fastening screw 400B, and then the first limiting screw 500A and the second limiting screw 500B are screwed into the first limiting screw hole 104A and the second limiting screw hole 104B of the drill rod 100 to abut against the first limiting surface 204B and the second limiting surface 204A, and the connection is firm and forms a whole;

[0048] The lower part of the replaceable drill tip 200 has a positioning structure, namely, a first positioning bevel 205A and a second positioning bevel 205B of the drill tip. The first positioning bevel 205A and the second positioning bevel 205B of the drill tip have the same spatial angle as the first positioning bevel 110A and the second positioning bevel 110B of the mounting structure 102 of the drill rod 100 and can be matched; after installation, the replaceable drill tip 200 and the drill rod 100 have a common common axis CL, ensuring that the replaceable drill tip 200 and the drill rod 100 rotate as a whole in the CCW direction about the common axis CL during operation, such as Fig.11 .

[0049] The first mounting surface 207A and the second mounting surface 207B of the replaceable drill tip are inclined at 90° to 100° with the adjacent first positioning inclined surface 205A and the second positioning inclined surface 205B of the drill tip.

[0050] like Figures 4 to 8As shown, the drill rod 100 is a combination of a drill body 109, a cone guard 107 and a cylindrical straight handle 106 coaxially with a common axis CL, and is provided with a spiral drill rod first chip groove 101A and a drill rod second chip groove 101B with the axis CL as the symmetry center, which are used to discharge the chips formed by drilling. The drill rod first chip groove 101A and the drill rod second chip groove 101B have a truncation shape on a TT section perpendicular to the axis CL, and the truncation shape is composed of four line segments connected in sequence, with the starting segment and the end segment being connected in sequence. The stop segments are the first straight line segment Z1 and the second straight line segment Z2, the middle segments are the first arc segment R1 and the second arc segment R2, and the truncated shape can select different arc radii and splicing angles according to the different sizes of the drill rod 100; the first chip groove 101A and the second chip groove 101B can be regarded as the extension of the first chip groove 203A and the second chip groove 203B of the replaceable drill tip 200 on the drill rod 100 along the axis CL after installation, and the length can be adjusted according to the drilling depth;

[0051] The upper end is provided with a mounting structure 102 for mounting a replaceable drill tip 200. The mounting structure 102 is a semi-enclosed groove 115 which is symmetrical about the common axis CL. The lower part of the groove 115 is a first positioning bevel 110A and a second positioning bevel 110B of the drill rod which serve as positioning surfaces. The first positioning bevel 110A and the second positioning bevel 110B of the drill rod are structurally symmetrical about the common axis CL and are arranged in a spatial V-shape. The V-shaped angle is 100° to 140°. When the replaceable drill tip 200 is installed, they are matched with the first positioning bevel 205A and the second positioning bevel 205B of the drill tip of the replaceable drill tip 200, respectively, so that the replaceable drill tip 200 is coaxial with the drill rod 100 about the common axis CL.

[0052] The solid parts on both sides of the groove 115 are provided with a first mounting screw hole 103A and a second mounting screw hole 103B above the first positioning inclined surface 110A and the second positioning inclined surface 110B of the drill rod, and a first limiting screw hole 104A and a second limiting screw hole 104B are provided below the first mounting screw hole 103A and the second mounting screw hole 103B; during installation, the drill rod 100 and the replaceable drill tip 200 are firmly combined into a whole by locking with the first fastening screw 400A and the second fastening screw 400B;

[0053] The drill rod 100 is used to install a replaceable drill tip 200. After installation, it is combined into a symmetrical bevel positioning replaceable drill bit for performing drilling processing.

[0054] like Fig. 9As shown, it is distributed 360° centrally symmetrically along the axis CL, and has at least a first cooling channel 120A and a second cooling channel 120B, and the first cooling channel 120A and the second cooling channel 120B are connected to the main cooling channel 105; during processing, it is used to provide coolant to the replaceable drill tip 200. When setting the cooling channel, the spatial arrangement of the first cooling channel 120A and the second cooling channel 120B is fully considered, and there is no interference with the first mounting screw hole 103A and the second mounting screw hole 103B, and there is no leakage of coolant.

[0055] like Fig.10 As shown, the cylindrical straight shank 106 at the lower end of the drill rod 100 is provided with an internal thread 107 for connecting a coolant line to provide coolant to the replaceable drill bit during drilling; a side pressure surface 108 is provided on the cylindrical straight shank 106 to facilitate the installation of the replaceable drill bit on a lathe by symmetrically positioning the inclined surface.

[0056] To sum up, the present invention has a unique design and a novel structure. The replaceable drill head includes a replaceable drill tip and a drill rod. The lower part of the replaceable drill tip has a symmetrical inclined positioning surface, and the upper part of the drill rod is provided with a mounting structure. The groove of the mounting structure has a drill rod positioning inclined surface with the same angle; the positioning structure spatial angles of the replaceable drill tip and the drill rod are the same and can cooperate. After installation, the replaceable drill tip and the drill rod have a common common axis CL, and the replaceable drill tip is stably fixed on the drill rod.

[0057] The first chip groove of the replaceable drill tip and the middle of the second chip groove of the drill tip are respectively provided with a first fastening through hole and a second fastening through hole; during installation, the replaceable drill tip is stably fixed on the drill rod by locking with two fastening screws, and the connection is firm and forms a whole;

[0058] The drill rod and the replaceable drill tip can be mounted together by two fastening screws to form a symmetrically inclined surface positioned replaceable drill head for performing drilling processing, so that the replaceable drill tip can be conveniently replaced without disassembling the tool rod during use.

[0059] It works in CCW direction and cuts smoothly. Different material grades and geometric features of replaceable drill tips can be selected according to the workpiece material. It has the characteristics of simple structure, accurate positioning, high mechanical strength, reliable installation, and can significantly improve the service life of the replaceable drill tip with low cost and good economy.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention. It should be noted that similar numbers and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0061] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope described in the claims.

[0062] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. Symmetrical bevel positioning replaceable drill bit, characterized by: It comprises a drill rod (100), a replaceable drill tip (200), a fastening screw 1 (400A), a fastening screw 2 (400B), a limit screw 1 (500A) and a limit screw (500B), wherein the replaceable drill tip (200) is installed on the drill rod (100) and has a common common axis CL; The replaceable drill tip (200) is a sheet-like structure that is 360° centrally symmetrical about the axis CL, and is provided with a first drill tip positioning inclined surface (205A) and a second drill tip positioning inclined surface (205B) at the lower end, and the first drill tip mounting surface (207A) and the second drill tip mounting surface (207B) are inclined with the adjacent first drill tip positioning inclined surface (205A) or the adjacent second drill tip positioning inclined surface (205B), and the lower part of the adjacent first drill tip mounting surface (207A) and the adjacent second drill tip mounting surface (207B) is provided with a second drill tip mounting surface (207A). The present invention relates to a sheet structure of a first limiting surface (204A) and a second limiting surface (204B), wherein the first limiting surface (204A) and the second limiting surface (204B) form a dovetail structure that is narrow at the top and wide at the bottom; a first cutting edge (202A) and a second cutting edge (202B) are arranged symmetrically along the axis CL at 360°, and the first cutting edge (202A) and the second cutting edge (202B) extend from the center axis CL to the maximum diameter on both sides with the upper end of the replaceable drill tip (200); and two cutting edges are arranged on the left and right sides. The first edge (201A) and the second edge (201B) are parts of the outermost imaginary cylinder of the first cutting edge (202A) and the second cutting edge (202B), have a width and are spiral-shaped; adjacent to the first cutting edge (202A) and the second cutting edge (202B), with the first edge (201A) and the second edge (201B) as edges, a first drill tip chip groove (203A) and a second drill tip chip groove (203B) are provided ), the first chip groove (203A) and the second chip groove (203B) of the drill tip are the natural extensions of the first cutting edge (202A) and the second cutting edge (202B) on the replaceable drill tip (200) in a spiral manner and along the first edge (201A) and the second edge (201B) with the axis CL as the reference; the first fastening through hole (206A) and the second fastening through hole (206B) are respectively arranged in the middle of the first chip groove (203A) and the second chip groove (203B) of the drill tip; The drill rod (100) is a combination of a drill body (109), a cone guard (107) and a cylindrical straight handle (106) coaxially with a common axis CL, and is provided with a spiral drill rod first chip removal groove (101A) and a drill rod second chip removal groove (101B) with the axis CL as the symmetry center. The upper end is provided with a mounting structure (102), and the mounting structure (102) is a semi-enclosed groove (115) symmetrically with the common axis CL. The lower part of the groove (115) is a drill locating surface. The first positioning inclined surface (110A) of the drill rod and the second positioning inclined surface (110B) of the drill rod; the solid parts on both sides of the groove (115), the first mounting screw hole (103A) and the second mounting screw hole (103B) are arranged above the first positioning inclined surface (110A) of the drill rod and the second positioning inclined surface (110B) of the drill rod, and the first limiting screw hole (104A) and the second limiting screw hole (104B) are arranged below the first mounting screw hole (103A) and the second mounting screw hole (103B); The first positioning bevel (205A) and the second positioning bevel (205B) of the drill tip cooperate with the first positioning bevel (110A) and the second positioning bevel (110B) of the drill rod, so that the replaceable drill tip (200) and the drill rod (100) are coaxial with the common axis CL; during installation, the first limiting screw hole (104A) and the second limiting screw hole (104B) of the drill rod (100) are screwed into the first limiting screw hole (104A) and the second limiting screw hole (104B) of the drill rod (100) by the limiting screw 1 (500A) and the limiting screw (500B) to abut against the first limiting surface (204A) and the second limiting surface (204B), so as to prevent the replaceable drill tip from being loosened from the drill rod.

2. The symmetrical bevel positioning replaceable drill bit according to claim 1, characterized in that: The first drill tip positioning inclined surface (205A) and the second drill tip positioning inclined surface (205B) are structurally symmetrical with respect to the common axis CL and are arranged in a spatial V-shape, with a spatial angle of 100° to 140°.

3. The symmetrical bevel positioning replaceable drill bit according to claim 1, characterized in that: The drill tip first mounting surface (207A) and the drill tip second mounting surface (207B) are inclined with the adjacent drill tip first positioning inclined surface (205A) or the drill tip second positioning inclined surface (205B), and the included angle is 90° to 100°.

4. The symmetrical bevel positioning replaceable drill bit according to claim 1, characterized in that: The first limiting surface (204A) and the second limiting surface (204B) of the drill tip form a dovetail structure that is narrow at the top and wide at the bottom, and the dovetail angle is 5° to 20°.

5. The symmetrical bevel positioning replaceable drill bit according to claim 1, characterized in that: The first cutting edge (202A) and the second cutting edge (202B) are in the shape of a straight line, an arc, or a spatial curve adapted to the cutting action.

6. The symmetrical bevel positioning replaceable drill bit according to claim 1, characterized in that: The outermost tangent lines of the first edge (201A) and the second edge (201B) form a helix angle (220) with the axis CL, and the helix angle (220) is 15° to 35°.

7. The symmetrical bevel positioning replaceable drill bit according to claim 1, characterized in that: The width of the first edge (201A) and the second edge (201B) is 0.05 to 0.1 times the diameter of the replaceable drill tip (200); the distance between the first edge (201A) and the second edge (201B) in the direction of the axis CL is the edge length, and the edge length is 0.3 to 1.0 times the diameter of the replaceable drill tip (200).

8. The symmetrical bevel positioning replaceable drill bit according to claim 1, characterized in that: The first chip removal groove (101A) and the second chip removal groove (101B) of the drill rod have a truncation shape on a cross section perpendicular to the axis CL, and the truncation shape is composed of four line segments connected in sequence, the starting segment and the ending segment are the first straight line segment (Z1) and the second straight line segment (Z2), and the middle segment is the first circular arc segment (R1) and the second circular arc segment (R2).

9. The symmetrical bevel positioning replaceable drill bit according to claim 1, characterized in that: The first positioning inclined surface (110A) and the second positioning inclined surface (110B) of the drill rod are structurally symmetrical with respect to the common axis CL and are arranged in a spatial V-shape, with a V-shaped angle of 100° to 140°. When the replaceable drill tip (200) is installed, the first positioning inclined surface (205A) and the second positioning inclined surface (205B) of the replaceable drill tip (200) can be matched to make the replaceable drill tip (200) and the drill rod (100) coaxial with the common axis CL.

10. The symmetrical bevel positioning replaceable drill bit according to claim 1, characterized in that: The drill rod is symmetrically distributed in 360 degrees about the axis CL, and has at least a first cooling channel (120A) and a second cooling channel (120B), wherein the first cooling channel (120A) and the second cooling channel (120B) are connected to the main cooling channel (105); the cylindrical straight handle (106) is provided with an internal pipe thread (117) for connecting to a cooling liquid path, and a side pressure surface (108) is provided on the cylindrical straight handle (106).

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