DRILL BIT WITH STEGRELIEF

Abstract

A drill bit comprises a body with a multitude of flutes extending along the body and a tip at one cutting end of the body. The tip has a web positioned between the flutes and a transverse cutting edge on the web. The tip has a cutting lip and a flank surface that defines one of the flutes. The cutting lip extends from the transverse cutting edge, and the flank surface extends from a side of the transverse cutting edge opposite the cutting lip. The web has a relief that extends into the flank surface.

Description

AREA OF INVENTION

[0001] The present disclosure relates to a cutting tool and in particular a drill bit with a relief in the web. BACKGROUND

[0002] When drilling holes, drill bits typically have a centrally located shank with a chisel edge at one end. As the drill bit rotates, its cutting lips remove material to create the hole. The surfaces of the shank also engage with the material during rotation, but instead of cutting, they push the material and restrict chip removal, generating high pressure and friction in a central area of ​​the drill bit. This high pressure and friction increase wear on the drill bit, reducing its durability and lifespan.

[0003] In some well-known drill bits, the shank is thinned to avoid the aforementioned problems of increased pressure and friction. However, thinning only the shank to address these problems compromises the drill bit's centering and stability, thereby reducing its cutting accuracy and overall performance. SUMMARY

[0004] A drill bit comprises a body with a multitude of flutes extending along the body and a tip at one cutting end of the body. The tip has a web positioned between the flutes and a transverse cutting edge on the web. The tip has a cutting lip and a flank surface that defines one of the flutes. The cutting lip extends from the transverse cutting edge, and the flank surface extends from a side of the transverse cutting edge opposite the cutting lip. The web has a relief that extends into the flank surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The invention will now be described by way of example with reference to the accompanying figures: Fig. 1 is a side view of an end section of a drill according to one embodiment; Fig. Figure 2 is a front view of a cutting end of the drill bit; Fig. Figure 3 is a detailed front view of section D of Fig. 2; Fig. Figure 4 is a perspective detail section view of section D of Fig. 2 along line 4-4 from Fig. 2; and Fig. Figure 5 is a front view of a cutting end of a drill bit according to another embodiment. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0006] Exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings, where identical reference numerals refer to identical elements. However, the present disclosure can be embodied in many different forms and should not be understood as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure fully conveys the concept of the disclosure to the person skilled in the art. Furthermore, numerous specific details are set forth in the following detailed description for explanatory purposes, in order to enable a comprehensive understanding of the disclosed embodiments. It is evident, however, that one or more embodiments can also be realized without these specific details.

[0007] In the drawings, only one of several identical elements in a figure may be labelled to improve clarity, but the detailed description of the element applies equally to each of the seemingly identical elements in the figure. Throughout the description, directional terms such as "axis of rotation," "circumferential direction," and "radial direction" are used. These terms serve only to clarify the description and distinguish the different directions. These directional terms do not imply or require any particular orientation of the disclosed elements.

[0008] A drill bit 10 according to one embodiment is in the Fig. Figures 1-3 show the drill bit 10 having a body 100 and a tip 200 at a cutting end 150 of the body 100. Fig. For the sake of clarity in the drawings and the corresponding description, only an end section 12 of the drill bit 10 is shown. However, it is understood that the body 100, with the elements described below, extends along a rotation axis A of the drill bit 10 from the end section 12 in a direction away from the tip 200 to a neck and / or shank of the drill bit 10.

[0009] As in Fig. As shown in Figure 1, the body 100 has a plurality of flutes 110 extending along the body 100 and along a rotation axis A of the drill 10. In the embodiment shown, the flutes 110 comprise a first flute 112 and a second flute 114, which extend helically along the body 100 about the rotation axis A. Each of the flutes 112, 114 has, as shown in Figure 1, a Fig. 1 and Fig. Figure 2 shows a first flute surface 116 extending from the cutting end 150, and a second flute surface 118 extending from the first flute surface 116 along the axis of rotation A. In the illustrated embodiment, the first flute surface 116 extends at a larger angle with respect to the axis of rotation A than the second flute surface 118.

[0010] Body 100 shows, as in Fig. 1 and Fig. Figure 2 shows a pair of channels 120 extending helically around the axis of rotation A through the body 100. The channels 120 are spaced apart from each other in a radial direction R of the body 100. Each of the channels 120 terminates at an end opening 122 at the 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 circular or other different cross-sectional shapes. In an exemplary embodiment, a cooling fluid can be supplied through the channels 120 during cutting to cool the drill 10.

[0011] Body 100 exhibits a pair of 130-degree facets, as in Fig. 1 and Fig. Figure 2 shows chamfers on a circumferential section of the body 100, extending in a circumferential direction C between the first chamfer groove 112 and the second chamfer groove 114. Each of the chamfers 130 can have one edge 132 or a plurality of edges 132 where the chamfer 130 is thicker or extends further from the axis of rotation A.

[0012] The tip 200 at the cutting end 150 of the body 100, as in Fig. 1 and Fig. Figure 2 shows a web 210 which is arranged between the clamping grooves 110 and is centrally aligned along the axis of rotation A. As shown in Fig. As shown in Figure 3, the web 210 has a first side surface 212 facing the first clamping groove 112 and a second side surface 214 opposite the first side surface 212, which faces the second clamping groove 114. The web 210 has a top surface 216 that points along the axis of rotation A and forms a section of the cutting end 150. The web 210 has a thickness 218 that extends radially R between the first side surface 212 and the second side surface 214. The web 210 has a length 219 that extends radially R perpendicular to the thickness 218. In the illustrated embodiment, the length 219 is greater than the thickness 218.

[0013] As in Fig. As shown in Figures 1-3, the tip 200 has a chisel edge 220 on the web 210. The chisel edge 220 is the leading end of the drill 10 at the cutting end 150, which is the first point of contact with the material to be cut. The chisel edge 220 is arranged centrally along the axis of rotation A, and the web 210 is angled relative to the chisel edge 220 in a direction extending along the axis of rotation A, as shown in Figure 1-3. Fig. 1 shown. The cross-section 220 has, as in Fig. Figure 3 shows a transverse cutting edge length of 222 in the radial direction R. In the illustrated embodiment, the web length 219 is greater than the transverse cutting edge length 222.

[0014] The top 200, as in Fig. Figure 2 shows a pair of flanks 230, which are surfaces extending between the chamfers 130 and the web 210. The flanks 230 are surfaces angled with respect to the axis of rotation A. Each flank 230 has a flank surface 232 that adjoins and defines one of the flutes 110. In the illustrated embodiment, each flank surface 232 has a straight section 234 extending from the cross-cutting edge 220 and a curved section 236 extending from the straight section 234 to one of the chamfers 130. The web 210 forms the straight section 234 of each of the flank surfaces 232. In another embodiment, the flank surfaces 232 may not have the straight section 234 and the curved section 236 may extend from the transverse cutting edge 220 to one of the chamfers 130; in this embodiment, the web 210 is formed in the curved section 236 of each of the flank surfaces 232.

[0015] As in Fig. As shown in Figure 2, the channels 120 are spaced radially R from the web 210. In the illustrated embodiment, the end opening 122 of each of the channels 120 extends through one of the flanks 230, the curved section 236 of one of the flank surfaces 232, and the first flute surface 116 of one of the flutes 110.

[0016] The tip 200 has a pair of cutting lips 240, as shown in Fig. Figure 2 shows a first cutting lip 242 and a second cutting lip 244. The cutting lips 240 are the main edges of the drill 10, which remove the material to be cut during the rotation of the drill 10 about the axis of rotation A. The first cutting lip 242 faces the first chip groove 112 and extends from the chisel edge 220 to one of the chamfers 130. The second cutting lip 244 faces the second chip groove 114 and extends from the chisel edge 220 to the other of the chamfers 130. The chisel edge 220 connects the first cutting lip 242 to the second cutting lip 244.

[0017] As in Fig. As shown in Figure 2, the first flute 112 is defined by one of the flank surfaces 232 and the first cutting lip 242; the flank surface 232 extends from one side of the cross-cutting edge 220 along the first side surface 212 of the web 210, and the first cutting lip 242 extends from an opposite side of the cross-cutting edge 220 along the first side surface 212. The second flute 114 is defined by one of the flank surfaces 232 and the second cutting lip 244; the flank surface 232 extends from one side of the cross-cutting edge 220 along the second side surface 214 of the web 210, and the second cutting lip 244 extends from an opposite side of the cross-cutting edge 220 along the second side surface 214.

[0018] As in Fig. As shown in Figures 1-3, the apex 200 has a pair of reliefs 250 extending into the flank surfaces 232. The reliefs 250 each represent an area where part of the bridge 210 has been removed.

[0019] At the in Fig. In the embodiment shown in Figure 3, the reliefs 250 comprise a first relief 252 and a second relief 254. The first relief 252 extends in the straight section 234 of one of the flank surfaces 232 into the first side surface 212 of the web 210. The second relief 254 extends in the straight section 234 of the other flank surface 232 into the second side surface 214 of the web 210. The first relief 252 and the second relief 254 are arranged on opposite sides of the cross-cutting edge 220. In other embodiments, the tip 200 may have a relief 250 extending into one of the flank surfaces 232.

[0020] Each of the 250 reliefs extends, as in Fig. Figure 3 shows the reliefs extending into one of the side surfaces 212, 214 of the web 210 and into the top surface 216 of the web 210. In the illustrated embodiment, the reliefs 250 do not extend into the transverse cutting edge 220, into either of the two cutting lips 240, or into the curved sections 236 of the flank surfaces 232; the reliefs 250 are limited to the straight sections 234 of the flank surfaces 232. In another embodiment, the reliefs 250 could extend into the curved sections 236, but do not extend beyond them.

[0021] Each of the 250 reliefs extends, as in Fig. Figure 3 shows a first end 256 extending to a second end 258 along the radial direction R on one of the side surfaces 212, 214 of the web 210. The first end 256 is located adjacent to and spaced apart from the cross-cutting 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 relief 250. The reliefs 250 each have a lateral side 260 connecting the first end 256 and the second end 258. In the illustrated embodiment, the lateral side 260 is parallel to the side surfaces 212, 214 of the web 210.In other embodiments, the lateral side 260 may have other shapes and is not necessarily flat, as shown, or parallel to the side surfaces 212, 214.

[0022] As in Fig. As shown in Figure 3, each of the reliefs 250 has a first relief depth 262 extending radially in the direction R into the web 210. The lateral side 260 is located radially in the first relief depth 262 in the side surface 212, 214 of the web 210. In one embodiment, the first relief depth 262 is up to 75% of the web thickness 218 in the radial direction R. In the embodiment shown, the first relief depth 262 is less than half the web thickness 218 in the radial direction R. As shown in Fig. As shown in Figure 1, each of the reliefs 250 has a second relief depth 264 that extends into the upper surface 216 of the web 210 in a direction along the axis of rotation A. In the illustrated embodiment, the second relief depth 264 is approximately equal to the first relief depth 262.

[0023] Each of the 250 reliefs shows, as in Fig. Figure 3 shows a relief length 266 along the side surface 212, 214 of the web 210 in the radial direction R between the first end 256 and the second end 258. In the illustrated embodiment, the relief length 266 is greater than the cross-cutting edge length 222. The first end 256 of each of the reliefs 250 is spaced from the cross-cutting edge 220 by a distance 268 that is smaller than the relief length 266 and smaller than the cross-cutting edge length 222. The relief length 266 is 5% to 50% of a drill radius 160 of the drill 10, which extends from the cross-cutting edge 220 in the radial direction R to one of the chamfers 130, as shown in Figure 3. Fig. 2 shown.

[0024] As in Fig. As shown in Figure 4, each of the reliefs 250 has a relief angle 270 between the lateral side 260 of the relief 250 and the cross-cutting edge 220. In one embodiment, the relief angle 270 can be up to 60°. In another embodiment, the relief angle 270 can be up to 45°. The cross-cutting edge 220 has a cross-cutting angle 224, as shown in Figure 4. Fig. Figure 4 shows the following: the cross-cutting angle 224 can be 10° to 25° in one embodiment. In another embodiment, the relief angle 270 can be 5° to 25° greater than the cross-cutting angle 224.

[0025] A drill bit 10' according to another embodiment is in Fig. 5 shown. The drill 10' is identical to the drill 10 shown in Fig. as shown in Figures 1-4 and described in detail above, except that the channels 120 are omitted in the drill 10'; the flanks 230 of the drill 10' have solid surfaces and the surfaces of the tip 200 of the drill 10' are not interrupted by the end openings 122 of the channels 120. Otherwise, the web 210, the chisel edge 220, the flanks 230, the cutting lips 240 and the reliefs 250 of the drill 10' are as shown above with reference to Fig. 1-4 described.

[0026] The drills 10, 10' according to the embodiments described above can be made of any material commonly used for drilling, such as a hard metal. In one embodiment, the body 100 and the tip 200 are formed monolithically in a single piece. In another embodiment, the tip 200 can be formed separately and attached to the body 100. The reliefs 250 can be formed in each embodiment by grinding the ridge 210 to remove material according to the specifications of the reliefs 250 described in detail above, for example, using a grinding wheel.

[0027] During drilling, the drill 10, 10' is rotated about the axis of rotation A, and the cutting end 150 is brought into contact with the material to be cut. As the drill 10, 10' penetrates the material, the cutting lips 240 remove the material as chips. The rib 210 also remains in contact with the material during rotation about the axis of rotation A. The presence of the reliefs 250 in the rib 210 reduces the pressure and friction generated by the engagement of the rib 210 with the material. The reliefs 250 also allow for smoother chip evacuation, further reducing the generated pressure and friction. The presence of the reliefs 250 thus reduces pressure and temperature without requiring further thinning of the rib 210, resulting in less wear and an improved service life without compromising the centering or stability of the drill 10, 10'.

Claims

[1] Drill, including: a body with a multitude of span grooves extending along the body; and a point at a cutting end of the body, wherein the point has a ridge arranged between the flutes and a transverse edge on the ridge, wherein the point has a cutting lip and a flank surface defining one of the flutes, wherein the cutting lip extends from the transverse edge and the flank surface extends from one side of the transverse edge opposite the cutting lip, wherein the ridge has a relief extending into the flank surface. [2] Drill bit according to claim 1, wherein the relief does not extend into the transverse cutting edge or the cutting lip. [3] Drill according to claim 1, wherein the relief extends into a side surface of the web which faces one of the flutes and into a top surface of the web. [4] Drill according to claim 1, wherein the relief extends from a first end to a second end along a side surface of the web, wherein the first end is arranged adjacent to the transverse cutting edge and is spaced apart from the transverse cutting edge. [5] Drill according to claim 4, wherein the relief has a relief length along the side surface of the web between the first end and the second end, wherein the relief length is greater than a cross-cutting edge length of the cross-cutting edge. [6] Drill according to claim 5, wherein the relief length is 5% to 50% of a drill radius of the drill. [7] Drill according to claim 5, wherein the first end is spaced away from the transverse cutting edge by a distance which is smaller than the relief length and smaller than the transverse cutting edge length. [8] Drill according to claim 4, wherein the relief has a lateral side connecting the first end and the second end, wherein the lateral side is arranged in the side surface of the web at a first relief depth in a radial direction, wherein the first relief depth is up to 75% of a web thickness of the web in the radial direction. [9] Drill according to claim 8, wherein the lateral side is flat and parallel to the side surface of the bridge. [10] Drill according to claim 8, wherein the relief has a second relief depth extending into a top surface of the web along an axis of rotation of the drill, wherein the second relief depth is approximately equal to the first relief depth. [11] Drill according to claim 8, wherein the relief has a relief angle between the lateral side and the transverse cutting edge of up to 60°. [12] Drill according to claim 1, wherein the flank surface has a straight section and a curved section, the web forms the straight section of the flank surface and the relief is limited to the straight section of the flank surface. [13] Drill according to claim 1, wherein the web has a web length along a radial direction which is greater than a transverse cutting edge length along the radial direction. [14] Drill according to claim 1, wherein the plurality of flutes comprises a first flute and a second flute extending helically along the body. [15] Drill according to claim 14, wherein the web has a first side surface facing the first flute and a second side surface facing the second flute, wherein the relief is a first relief extending into the first side surface and the web has a second relief extending into the second side surface. [16] Drill according to claim 15, wherein the first relief and the second relief are arranged on opposite sides of the transverse cutting edge. [17] Drill according to claim 15, wherein the cutting lip is a first cutting lip defining the first chip groove with the flank surface, the tip has a second cutting lip and a further flank surface defining the second groove, the first relief extends into the flank surface and the second relief extends into the other flank surface. [18] Drill according to claim 1, wherein the body has a pair of channels extending helically through the body around an axis of rotation of the drill. [19] Drill according to claim 18, wherein the channels are spaced apart from the web and one of the channels has an end opening extending through the flank surface. [20] Drill bit according to claim 1, wherein the body and the tip are formed monolithically in a single piece from a hard metal material.

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