Drill bit with core relief
By designing a gap structure on the drill bit core, the wear problem caused by high pressure and high friction during drilling is solved, extending the service life of the drill bit and maintaining cutting accuracy and stability.
Patent Information
- Application Number
- CN202511173643.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-08-27
- Filing Date
- 2025-08-21
- Publication Date
- 2026-03-06
AI Technical Summary
Existing drill bits experience increased wear due to the high pressure and friction generated during drilling, which affects durability and service life. At the same time, thinning the drill core to solve this problem would compromise centering and cutting accuracy.
Design a clearance structure on the drill core. By introducing clearance in the flank face, the contact pressure and friction between the drill core and the material are reduced, chip removal is improved, and the drill core is prevented from becoming thinner.
It effectively reduces drill bit wear and extends service life, while maintaining drill bit centering and cutting accuracy without affecting drill bit stability and performance.
Smart Images
Figure CN121607685A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a cutting tool, and more specifically to a drill bit having relief in the web. Background Technology
[0002] In drilling, a drill bit typically has a centrally located core with a chisel edge at the cutting end. During rotation, the cutting edge of the drill bit chips or removes material to create a hole. The surface of the core also engages with the material during rotation, but pushes the material rather than cutting it and restricts chip removal, which generates high pressure and high friction in the central region of the drill bit. This high pressure and friction increase wear on the drill bit, thereby reducing its durability and service life.
[0003] In some existing drill bits, the core is thinned to avoid the aforementioned problems of increased pressure and friction. However, specifically thinning the core to address these issues can compromise the drill bit's centering and stability, thereby reducing its cutting accuracy and performance. Summary of the Invention
[0004] The drill bit comprises a body having a plurality of grooves extending along the body and a tip located at the cutting end of the body. The tip has a core positioned between the grooves and a chisel edge on the core. The tip has a cutting edge defining one of the grooves and a flank face surface. The cutting edge extends from the chisel edge, and the flank face surface extends from the side of the chisel edge opposite to the cutting edge. The core has a clearance extending into the flank face surface. Attached Figure Description
[0005] The invention will now be described by way of example with reference to the accompanying drawings, in which:
[0006] Figure 1 This is a side view of the end section of the drill bit according to an embodiment;
[0007] Figure 2 This is a front view of the cutting end of the drill bit;
[0008] Figure 3 for Figure 2 Partial front detail view of D;
[0009] Figure 4 for Figure 2 Part D along Figure 2 The perspective detail view of the section cut by line 4-4; and
[0010] Figure 5 This is a front view of the cutting end of a drill bit according to another embodiment. Detailed Implementation
[0011] Exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings, wherein like reference numerals denote like elements. However, the present disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the concepts of the present disclosure will be conveyed to those skilled in the art. Furthermore, in the following detailed description, numerous specific details are set forth for purposes of explanation in order to provide a thorough understanding of embodiments of the present disclosure. However, it will be apparent, however, that one or more embodiments may be practiced without these specific details.
[0012] Throughout the drawings, for clarity, only one of several identical elements may be labeled, but the detailed descriptions of the elements herein also apply to each of the same presented elements in the drawings. Throughout the specification, directional descriptive terms such as "rotation axis," "circumferential direction," and "radial direction" are used. These descriptive terms are used solely for clarity and to distinguish between various directions. These directional descriptive terms do not imply or require any particular orientation of the disclosed elements.
[0013] exist Figures 1 to 3 The image shows a drill bit 10 according to an embodiment. The drill bit 10 has a body 100 and a tip 200 located at a cutting end 150 of the body 100. Figure 1 For clarity of illustration and corresponding description, only the end section 12 of the drill bit 10 is shown. However, it should be understood that the body 100 having the elements described below continues along the axis of rotation A of the drill bit 10 from the end section 12 in a direction away from the tip 200 to the neck and / or shank of the drill bit 10.
[0014] like Figure 1 As shown, the body 100 has a plurality of grooves 110 extending along the body 100 and along the rotation axis A of the drill bit 10. In the illustrated embodiment, the grooves 110 include a first groove 112 and a second groove 114 extending helically along the body 100 about the rotation axis A. Figure 1 and Figure 2 Each of the grooves 112 and 114 shown has a first groove surface 116 extending from the cutting end 150 and a second groove surface 118 extending from the first groove surface 116 along the rotation axis A. In the illustrated embodiment, the first groove surface 116 extends relative to the rotation axis A at a larger angle than the second groove surface 118.
[0015] like Figure 1 and Figure 2As shown, the body 100 has a pair of channels 120 extending helically through the body 100 about a rotation axis A. The channels 120 are spaced apart from each other in the radial direction R of the body 100. Each of the channels 120 terminates at an end opening 122 at a tip 200. In the illustrated embodiment, each of the channels 120 is a circular opening extending through the body 100; in other embodiments, the body 100 may have one, three, or more channels 120, which may have a circular shape or other different cross-sectional shapes. In an exemplary embodiment, cooling fluid may be supplied through the channels 120 during cutting to cool the drill bit 10.
[0016] like Figure 1 and Figure 2 As shown, the body 100 has a pair of cutting edges 130 on its peripheral portion and extends in the circumferential direction C between a first groove 112 and a second groove 114. Each of the cutting edges 130 may have a margin 132 or more margins 132, wherein the cutting edge 130 is thicker or extends further away from the axis of rotation A at the margin.
[0017] like Figure 1 and Figure 2 As shown, the tip 200 at the cutting end 150 of the body 100 has a drill core 210 positioned between the grooves 110 and centered along the axis of rotation A. Figure 3 As shown, the drill core 210 has a first side surface 212 facing the first groove 112 and a second side surface 214 facing the second groove 114 opposite to the first side surface 212. The drill core 210 has an upper surface 216 facing the portion along the rotation axis A and forming the cutting end 150. The drill core 210 has a drill core thickness 218 extending in the radial direction R between the first side surface 212 and the second side surface 214. The drill core 210 has a drill core length 219 extending in the radial direction R perpendicular to the drill core thickness 218. In the illustrated embodiment, the drill core length 219 is greater than the drill core thickness 218.
[0018] like Figures 1 to 3 As shown, the tip 200 has a chisel edge 220 on the drill core 210. The chisel edge 220 is the tip of the drill bit 10 that first contacts the material to be cut at the cutting end 150. The chisel edge 220 is centrally positioned along the rotation axis A, and the drill core 210 is angled to the chisel edge 220 in the direction extending along the rotation axis A, as shown. Figure 1 As shown. Figure 3 As shown, the chisel edge 220 has a chisel edge length 222 in the radial direction R. In the illustrated embodiment, the drill core length 219 is greater than the chisel edge length 222.
[0019] like Figure 2As shown, the tip 200 has a pair of flank faces 230 extending face-to-face between the cutting edge 130 and the drill core 210. The flank faces 230 are angled relative to the axis of rotation A. Each of the flank faces 230 has a flank face surface 232 that defines and demarcates one of the grooves 110. In the illustrated embodiment, each flank face surface 232 has a straight section 234 extending from the chisel edge 220 and a curved section 236 extending from the straight section 234 to one of the cutting edges 130. The drill core 210 forms the straight section 234 of each of the flank face surfaces 232. In another embodiment, the flank face surface 232 may not have the straight section 234, and the curved section 236 may extend from the chisel edge 220 to one of the cutting edges 130; in this embodiment, the drill core 210 is formed in the curved section 236 of each of the flank face surfaces 232.
[0020] like Figure 2 As shown, the channel 120 is spaced apart from the drill core 210 in the radial direction R. In the illustrated embodiment, the end opening 122 of each of the channels 120 extends through a curved section 236 of one of the flank faces 230, one of the flank face surfaces 232, and a first groove surface 116 of one of the grooves 110.
[0021] like Figure 2 As shown, the tip 200 has a pair of cutting edges 240, including a first cutting edge 242 and a second cutting edge 244. The cutting edges 240 are the primary edges of the drill bit 10, which remove the material to be cut during rotation of the drill bit 10 about the axis of rotation A. The first cutting edge 242 faces the first groove 112 and extends from the chisel edge 220 to one of the cutting edges 130. The second cutting edge 244 faces the second groove 114 and extends from the chisel edge 220 to the other of the cutting edges 130. The chisel edge 220 connects the first cutting edge 242 to the second cutting edge 244.
[0022] like Figure 2 As shown, the first groove 112 is defined by one of the flank surfaces 232 and a first cutting edge 242; the flank surface 232 extends from one side of the chisel edge 220 along the first side surface 212 of the drill core 210, and the first cutting edge 242 extends from the opposite side of the chisel edge 220 along the first side surface 212. The second groove 114 is defined by one of the flank surfaces 232 and a second cutting edge 244; the flank surface 232 extends from one side of the chisel edge 220 along the second side surface 214 of the drill core 210, and the second cutting edge 244 extends from the opposite side of the chisel edge 220 along the second side surface 214.
[0023] like Figures 1 to 3 As shown, the tip 200 has a pair of gaps 250 extending into the flank face surface 232. Each gap 250 is a region in which a portion of the drill core 210 has been removed.
[0024] exist Figure 3 In the illustrated embodiment, the clearance 250 includes a first clearance 252 and a second clearance 254. The first clearance 252 extends in a straight segment 234 of one of the flank face surfaces 232 into a first side surface 212 of the drill core 210. The second clearance 254 extends in a straight segment 234 of the other of the flank face surfaces 232 into a second side surface 214 of the drill core 210. The first clearance 252 and the second clearance 254 are positioned on opposite sides of the chisel edge 220. In other embodiments, the tip 200 may have one clearance 250 extending into one of the flank face surfaces 232.
[0025] like Figure 3 As shown, each of the gaps 250 extends into one of the side surfaces 212, 214 of the drill core 210 and into the upper surface 216 of the drill core 210. In the illustrated embodiment, the gap 250 does not extend into the chisel edge 220, into any of the cutting edges 240, or into the curved section 236 of the flank face surface 232; the gap 250 is contained within the straight section 234 of the flank face surface 232. In another embodiment, the gap 250 may extend into the curved section 236, but does not extend beyond the curved section 236.
[0026] like Figure 3 As shown, each of the gaps 250 extends radially R from a first end 256 to a second end 258 on one of the side surfaces 212, 214 of the drill core 210. The first end 256 is positioned adjacent to and spaced apart from the chisel edge 220. In the illustrated embodiment, the first end 256 has an angled shape and the second end 258 has a curved shape. In other embodiments, the shapes of the first end 256 and the second end 258 may differ from those in the illustrated embodiment depending on the process used to create the gaps 250. Each gap 250 has a transverse side 260 connecting the first end 256 and the second end 258. In the illustrated embodiment, the transverse side 260 is parallel to the side surfaces 212, 214 of the drill core 210. In other embodiments, the transverse side 260 may have other shapes and need not be flat or parallel to the side surfaces 212, 214 as shown.
[0027] like Figure 3 As shown, each of the gaps 250 has a first gap depth 262 extending radially into the drill core 210. The lateral sides 260 are positioned radially into the side surfaces 212, 214 of the drill core 210 at the first gap depth 262. In one embodiment, the first gap depth 262 is up to 75% of the drill core thickness 218 in the radial direction R. In the illustrated embodiment, the first gap depth 262 is less than half the drill core thickness 218 in the radial direction R. Figure 1As shown, each of the gaps 250 has a second gap depth 264 extending in the direction along the rotation axis A into the upper surface 216 of the drill core 210. In the illustrated embodiment, the second gap depth 264 is approximately equal to the first gap depth 262.
[0028] like Figure 3 As shown, each of the gaps 250 has a gap length 266 in the radial direction R along the side surfaces 212, 214 of the drill core 210 between a first end 256 and a second end 258. In the illustrated embodiment, the gap length 266 is greater than the chisel edge length 222. The first end 256 of each of the gaps 250 is spaced from the chisel edge 220 by a distance 268 smaller than the gap length 266 and smaller than the chisel edge length 222. Figure 2 As shown, the clearance length 266 is 5% to 50% of the drill radius 160 of the drill bit 10 extending from the chisel edge 220 to one of the cutting edges 130 in the radial direction R.
[0029] like Figure 4 As shown, each of the gaps 250 has a rear angle 270 between its lateral side 260 and the transverse blade 220. In one embodiment, the rear angle 270 can be up to 60°. In another embodiment, the rear angle 270 can be up to 45°. The transverse blade 220 has as shown... Figure 4 The transverse cutting angle 224 is shown in the figure; in an embodiment, the transverse cutting angle 224 may be 10° to 25°. In an embodiment, the back angle 270 may be 5° to 25° larger than the transverse cutting angle 224.
[0030] exist Figure 5 The image shows a drill bit 10' according to another embodiment. The drill bit 10' and... Figures 1 to 4 The drill bit 10 shown and described in detail above is the same as that described above, except that the channel 120 is omitted in the drill bit 10'; the flank face 230 of the drill bit 10' has a solid surface, and the surface of the tip 200 of the drill bit 10' is not interrupted by the end opening 122 of the channel 120. In addition, the core 210, chisel edge 220, flank face 230, cutting edge 240, and clearance 250 of the drill bit 10' are the same as those described above. Figures 1 to 4 The description is the same.
[0031] Drill bits 10, 10' according to the embodiments described above can be formed of any material commonly used for drilling, such as carbide materials. In one embodiment, the body 100 and the tip 200 are integrally formed as a single piece. In another embodiment, the tip 200 can be formed separately and attached to the body 100. In any embodiment, the gap 250 can be formed by grinding the drill core 210 to remove material to the specifications of the gap 250 described in detail above, for example with a grinding wheel.
[0032] During hole cutting, drill bits 10, 10' rotate about axis A, and the cutting edge 150 moves to contact the material to be cut. As drill bits 10, 10' penetrate the material, the cutting edge 240 removes the material into chips. Drill core 210 also contacts the material during rotation about axis A. Due to the presence of clearance 250 in drill core 210, the pressure and friction generated by the engagement of drill core 210 with the material are reduced. Clearance 250 also allows for smoother chip removal, further reducing the generated pressure and friction. The presence of clearance 250 thus reduces pressure and temperature without requiring further thinning of drill core 210, resulting in less wear and longer life without compromising the centering or stability of drill bits 10, 10'.
Claims
1. A drill bit comprising: a body having a plurality of flutes extending along the body; and a tip at a cutting end of the body, the tip having a core positioned between the flutes and a land on the core, the tip having a cutting edge and a relief surface defining one of the flutes, the cutting edge extending from the land and the relief surface extending from a side of the land opposite the cutting edge, the core having a relief extending into the relief surface.
2. The drill bit of claim 1, wherein the relief does not extend into the land or the cutting edge.
3. The drill bit of claim 1, wherein the relief extends into a side surface of the core facing the one of the flutes and into an upper surface of the core.
4. The drill bit of claim 1, wherein the relief extends along a side surface of the core from a first end positioned adjacent to and spaced apart from the land to a second end.
5. The drill bit of claim 4, wherein the relief has a relief length along the side surface of the core between the first end and the second end, the relief length being greater than a land length of the land.
6. The drill bit of claim 5, wherein the relief length is 5% to 50% of a bit radius of the drill bit.
7. The drill bit of claim 5, wherein the first end is spaced apart from the land by a spacing distance that is less than the relief length and less than the land length.
8. The drill bit of claim 4, wherein the relief has a lateral side connecting the first end and the second end, the lateral side positioned into the side surface of the core in a radial direction by a first relief depth, the first relief depth being up to 75% of a core thickness of the core in the radial direction.
9. The drill bit of claim 8, wherein the lateral side is flat and parallel to the side surface of the core.
10. The drill bit of claim 8, wherein the relief has a second relief depth extending into an upper surface of the core along an axis of rotation of the drill bit, the second relief depth being substantially equal to the first relief depth.
11. The drill bit of claim 8, wherein the relief has a relief angle of up to 60° between the lateral side and the land.
12. The drill bit of claim 1, wherein the relief surface has a straight section and a curved section, the core forming the straight section of the relief surface, the relief being contained within the straight section of the relief surface.
13. The drill bit of claim 1, wherein a core length of the core along a radial direction is greater than a land length of the land along the radial direction.
14. The drill bit of claim 1, wherein the plurality of flutes includes a first flute and a second flute extending helically along the body.
15. The drill bit of claim 14, wherein the drill core has a first side surface facing the first flute and a second side surface facing the second flute, the relief being a first relief extending into the first side surface and the drill core having a second relief extending into the second side surface.
16. The drill bit of claim 15, wherein the first relief and the second relief are positioned on opposite sides of the chisel edge.
17. The drill bit of claim 15, wherein the cutting edge is a first cutting edge that bounds the first flute with the flank surface, the tip having a second cutting edge that bounds the second flute and another flank surface, the first relief extending into the flank surface and the second relief extending into the other flank surface.
18. The drill bit of claim 1, wherein the body has a pair of channels extending helically through the body about an axis of rotation of the drill bit.
19. The drill bit of claim 18, wherein the channels are spaced apart from the drill core, and one of the channels has an end opening extending through the flank surface.
20. The drill bit of claim 1, wherein the body and the tip are integrally formed as a single piece from a carbide material.