Drill tip and drill bit

Abstract

The invention relates to a drill tip and a drill bit wherein the drill tip comprises a body having a central positioning tip at the top end thereof and at least three cutting structures wherein each cutting structure comprises: a main cutting edge abutting the central positioning tip and extending outwardly from the bottom of the central positioning tip, the main cutting edge is located at the intersection of the front tool face and the rear tool face. A cutting edge portion disposed at an outer edge of the flank surface; a chip containing groove and a chip discharging groove are formed between every two adjacent cutting structures, and the chip containing grooves and the chip discharging grooves communicate with each other and extend into the center positioning tip. The vertex of the central positioning tip is higher than that of the cutting edge part, and the vertex of the cutting edge part is higher than the main cutting edge. The drill tip and the drill bit have the advantages of being low in drilling resistance, high in drilling efficiency and long in service life of the drill tip.

Description

Technical Field

[0001] This invention relates to the field of cutting tool technology, and in particular to a drill tip and drill bit. Background Technology

[0002] Existing drilling tools, depending on the material being drilled, mainly include metalworking drill bits and woodworking drill bits. These two types of drill bits differ significantly in their structural design due to the different materials they process. Woodworking drill bits, as tools specifically designed for drilling holes in various types of wood, typically have multiple main cutting edges, a center locating tip, and a scribing edge (marking edge) on the outer periphery. During drilling, the center locating tip is used for positioning, and the scribing edge cuts wood fibers circumferentially to form the drilling area. Finally, the main cutting edges remove material within the outline area, thus forming the desired hole.

[0003] While current woodworking drill bits are capable of effectively drilling various types of wood, higher drilling efficiency and longer lifespan remain design goals for woodworking drill bits. Existing woodworking drill bits still suffer from shortcomings such as insufficient chip removal, excessive drilling resistance, and easy wear, which limit their drilling efficiency, machining accuracy, and lifespan. Summary of the Invention

[0004] To at least partially solve the above problems, the present invention provides a drill tip and drill bit to reduce drilling resistance, improve drilling efficiency and service life.

[0005] A drill tip according to the present invention includes a body, the top of the body having a central positioning tip, and at least three cutting structures, wherein each cutting structure includes: The main cutting edge is adjacent to the center locating tip and extends outward from the bottom of the center locating tip, and the main cutting edge is located at the intersection of the rake face and the flank face; The cutting edge is located at the outer edge of the back face; A chip-collecting groove and a chip-removing groove are formed between two adjacent cutting structures. The chip-collecting groove and the chip-removing groove are connected and extend into the central positioning tip. The apex of the central positioning tip is higher than the apex of the cutting edge, and the apex of the cutting edge is higher than the main cutting edge.

[0006] As a preferred embodiment, the central positioning tip is a pyramidal structure, the chip groove extends into the conical surface of the central positioning tip, and an inner edge is formed at the intersection of the chip groove and the conical surface.

[0007] As a preferred, the main cutting edge includes an inner edge portion and an outer edge portion, the outer edge portion is an arc-shaped edge and is adjacent to the inner edge portion, the inner edge portion is a straight line edge and is adjacent to the center positioning tip, the inner edge portion is located at the intersection of the rake face of the rear cutting structure and the chip pocket of the front cutting structure.

[0008] As a preferred, the height of the main cutting edge gradually decreases from the side adjacent to the center positioning tip outwardly and forms an inclination angle of 1-3°.

[0009] As a preferred, the cutting edge portion includes a first cutting edge portion and a second cutting edge portion arranged in front and back, the first cutting edge portion is located between the main cutting edge and the second cutting edge portion, and the vertex of the second cutting edge portion is higher than that of the first cutting edge portion.

[0010] As a preferred, the rake face includes a first rake face and a second rake face, the first rake face is higher than the second rake face; the first cutting edge portion is arranged on the first rake face, and the second cutting edge portion is arranged on the second rake face.

[0011] As a preferred, the first cutting edge portion and the second cutting edge portion are both formed with an arc-shaped cutting edge.

[0012] As a preferred, the height difference between the vertex of the first cutting edge portion and the main cutting edge is 0.2mm-0.4mm, the height difference between the vertex of the second cutting edge portion and the main cutting edge is 0.5mm-0.6mm, and the height difference between the center positioning tip and the main cutting edge is 1mm-1.5mm.

[0013] A drill bit, comprising a drill rod and the drill tip as described above mounted on the drill rod.

[0014] As a further preferred, the bottom end of the main body of the drill tip is formed with a protruding welding portion, the drill rod has a welding surface, a groove matching the welding portion is formed on the welding surface, and the bottom end of the drill tip is welded with the welding surface of the drill rod.

[0015] The beneficial effects of the present application are at least embodied in: The drill tip and the drill bit provided by the present application can greatly improve the design freedom of the center positioning tip, the main cutting edge and the chip pocket space, and improve the drilling performance of the drill tip, thanks to the improved cutting structure design. The drilling resistance can be significantly reduced without reducing the overall strength of the drill tip, and the chip removal is easier, which can effectively improve the drilling efficiency and the service life of the drill tip. Based on some embodiments, the durability of the cutting edge of the drill tip can also be improved, thereby further improving the service life of the drill tip. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The drill tip structure of an embodiment of the present application is shown in the figure. Figure 2 For Figure 1 a top view of the drill tip; Figure 3 a schematic view of a drill tip structure according to another embodiment of the present application; Figure 4 For Figure 3 a top view of the drill tip; Figure 5 a schematic view of a drill bit structure according to an embodiment of the present application; Figure 6 a schematic view of a drill tip structure according to another embodiment of the present application; Figure 7 For Figure 6 a top view of the drill tip; Figure 8 For Figure 7 another view of the drill tip; Figure 9 a schematic view of a drill bit structure according to another embodiment of the present application; Figure 10 For Figure 9 a schematic view of a drill bit shank portion structure.

[0017] Reference numerals: 1 - drill tip, 2 - centering tip, 201 - pyramidal face, 3 - main cutting edge, 301 - inner edge portion, 302 - outer edge portion, 4 - cutting edge portion, 5 - first cutting edge portion, 501 - first cutting edge, 502 - first inner side face, 6 - second cutting edge portion, 601 - second cutting edge, 602 - second inner side face, 7 - relief face, 8 - first relief face, 9 - second relief face, 10 - chip pocket, 11 - first pocket face, 12 - second pocket face, 13 - chip flutes, 14 - inner land, 15 - outer peripheral wall face, 16 - rake face, 17 - back wall face, 18 - connecting face, 19 - welding portion, 20 - shank, 21 - welding face, 22 - recess, 23 - shank chip flutes. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0019] With reference to Figures 1-10 , the present application provides the following embodiments.

[0020] A drill tip 1 comprising a body having a centering tip 2 at a top end thereof, and at least three cutting structures, wherein each cutting structure comprises: The main cutting edge 3 is adjacent to the center positioning tip 2 and extends outward from the bottom of the center positioning tip 2 to an outer peripheral wall surface 15. The main cutting edge 3 is located at the intersection of the rake face 16 and the flank face 7. The cutting edge 4 is located at the outer edge of the back face 7; A chip-collecting groove 10 and a chip-removing groove 13 are formed between two adjacent cutting structures. The chip-collecting groove 10 and the chip-removing groove 13 are connected and extend into the center positioning tip 2. The vertex of the central positioning tip 2 is higher than the vertex of the cutting edge 4, and the vertex of the cutting edge 4 is higher than the main cutting edge 3.

[0021] It should be noted that the at least three cutting structures described in this embodiment have the same configuration, and each cutting structure is rotationally symmetrical about the central axis of the central positioning tip. For ease of explanation, the embodiments of the present invention all use the case of a drill tip with three cutting structures as examples. It should also be noted that the term "outer side" in this embodiment refers to the central positioning tip as the "inner side," that is, the side away from the central positioning tip is the "outer side."

[0022] It is understood that the drill tip of the present invention is particularly suitable for drilling wood. When the drill tip 1 is drilling, the center positioning tip 2 first contacts the wood surface to locate and pre-drill the center of the hole. Then the cutting edge 4 cuts the wood fibers along the circumference to form the drilling range. Finally, the main cutting edge 3 cuts away the material in the circumference to form the required hole.

[0023] Furthermore, it can be understood that in the specific design of the drill tip described above, the chip removal groove 13 formed between two adjacent cutting structures serves to remove the wood chips generated after the main cutting edge cuts the wood. The chip removal groove 13 is typically formed by connecting the rear wall surface 17 of the front cutting structure and the rake face 16 of the rear cutting structure. The rear wall surface 17 of the cutting structure is adjacent to the rake face 7. The chip removal groove 13 can be configured as follows: Figure 1 and Figure 6 The spiral groove shown, formed by the connection of the arc-shaped rake face 16 and the arc-shaped rear wall face 17, can also be configured, for example... Figure 3 The V-shaped groove shown is formed by the connection of the arc-shaped rake face 16 and the beveled rear wall face 17. It should be noted that the terms "front side" and "rear side" refer to the direction of rotation of the drill tip.

[0024] It is worth noting that when the drill tip is drilling, the center positioning tip will extrude and crush wood fibers, and the generated wood chips are easy to accumulate at the junction of the rear flank surface and the bottom of the center positioning tip and are not easy to discharge, resulting in increased drilling friction resistance of the center positioning tip, which makes the center positioning tip prone to heating and reduces durability. In the present embodiment, by opening the chip groove 10 extending into the center positioning tip 2, it provides a discharge space and path for the wood chips generated at the center positioning tip, so that the wood chips are more easily and smoothly discharged from the center positioning tip area to the chip discharge groove 13, more cleverly avoiding the wood chips being blocked at the junction of the rear flank surface and the bottom of the center positioning tip, thereby greatly reducing the friction resistance.

[0025] In some embodiments, the center positioning tip 2 is configured as a pyramid structure, and the chip groove 10 extends into the pyramid surface 201 of the center positioning tip, and an inner edge 14 is formed at the intersection of the chip groove 10 and the pyramid surface 201. As a specific embodiment, corresponding to the design of the drill tip having three cutting structures, the center positioning tip can be configured as a triangular pyramid structure.

[0026] It is worth noting that the center positioning tip removes material mainly through the extrusion effect of the pyramid surface during drilling, and this method has the problem of poor material removal effect. In the present embodiment, the inner edge 14 formed by the intersection of the chip groove 10 and the pyramid surface 201 can cut the material that has not been completely separated to some extent, thereby converting the pure extrusion effect of the center positioning tip into a combination of extrusion and cutting effect, significantly improving the material removal efficiency, and thereby reducing the drilling resistance and improving the drilling efficiency.

[0027] In some embodiments, the main cutting edge 3 includes an inner edge portion 301 and an outer edge portion 302, the outer edge portion 302 is an arc-shaped edge and is adjacent to the inner edge portion 301, the inner edge portion 301 is a straight line edge and is adjacent to the bottom of the center positioning tip 2, and the inner edge portion 301 is located at the intersection of the rear flank surface 7 of the rear cutting structure and the chip groove 10 of the front cutting structure.

[0028] It can be understood that in the drill tip design, the smaller the "core thickness" of the center positioning tip, the more conducive to the center positioning tip being configured in a sharp and thin shape, thereby making the drilling resistance smaller. The size of the "core thickness" of the center positioning tip can be measured by the diameter of the circumscribed circle C2 of the bottom section of the center positioning tip, and the smaller the diameter of the circumscribed circle C2, the smaller the "core thickness" of the center positioning tip. In the existing woodworking drill bit design with three or more cutting structures, the main cutting edge is usually configured by an arc edge, and in order to achieve the purpose of reducing the drilling resistance of the drill tip, the arc edge is usually extended as far as possible to the center to compress the core thickness of the center positioning tip. However, based on this way, as the arc edge extends from the outside to the center, the core thickness of the drill tip becomes thinner, thereby reducing the strength of the drill tip. Based on the configuration of the main cutting edge in the above embodiments of the present application, the arc edge (outer edge portion) is not directly extended to the bottom of the center positioning tip, but the straight edge (inner edge portion) formed by intersecting with the chip flute is extended to the bottom of the center positioning tip. The core thickness of the center positioning tip can be reduced without reducing the core thickness of the drill tip. Referring to Figure 2 and 7 Fig. shows the circumscribed circle C2 of the bottom section of the center positioning tip, and the size of the core thickness of the drill tip can be measured by the diameter of the inscribed circle C1.

[0029] It can be further understood that in some embodiments, the main cutting edge of the drill tip can also be directly configured by an arc edge, and in these embodiments, thanks to the design of the chip flute, the purpose of reducing the drilling resistance can be achieved, so that the arc edge does not need to be excessively extended to the center to reduce the core thickness of the center positioning tip, thereby avoiding the problem of reduced strength caused by the thinning of the core thickness of the drill tip.

[0030] As a specific embodiment, as shown in Figure 1 , the chip flute 10 is configured to be formed by the intersection of at least the first flute surface 11 and the second flute surface 12. Further, the inner edge portion 301 is formed by the intersection of the first flute surface 11 and the relief surface 7 of the rear cutting structure, at this time, the first flute surface 11 simultaneously becomes the rake surface of the inner edge portion 301; the second flute surface 12 is respectively adjacent to the flute surface of the chip flute 13 and the relief surface 7.

[0031] Referring to Figures 6-8 , in some embodiments, the cutting edge part of the drill tip is configured to include a first cutting edge part 5 and a second cutting edge part 6 arranged in front and back, the first cutting edge part 5 is located between the main cutting edge 3 and the second cutting edge part 6, and the vertex of the second cutting edge part 6 is higher than that of the first cutting edge part 5.

[0032] It can be understood that in the woodworking drill bit, the function of the cutting edge part is to cut wood along the circumference to form a drilling range, and the cutting edge of the cutting edge part needs to bear a large friction effect with the wood, and because the cutting edge has a long stroke, the cutting edge is prone to wear after long-term use, which in turn causes the subsequent scribing to fail or the scribing quality to be poor, thereby affecting the overall service life of the drill bit. In the above embodiments, by providing two cutting edge parts of different heights, the wood is cut in turn, which can achieve the effect of prolonging the service life of the cutting edge.

[0033] Referring to Figure 6 and Figure 7 In some embodiments, the rear face includes a first rear face 8 and a second rear face 9, the first rear face 8 is higher than the second rear face 9, the first rear face 8 and the second rear face 9 are connected by a connecting face 18 to form a stepped face, the first cutting edge part 5 is arranged on the first rear face 8, and the second cutting edge part 6 is arranged on the second rear face 9.

[0034] It can be understood that in the above embodiments, by arranging two cutting edge parts (the first cutting edge part 5 and the second cutting edge part 6) on two rear faces of different heights, the heat dissipation space of the cutting edge part can be increased, and the heat dissipation problem caused by arranging two cutting edge parts on the rear face at the same time can be better solved.

[0035] In some embodiments, the first cutting edge part 5 and the second cutting edge part 6 are both formed with an arc-shaped cutting edge. As a specific, referring to Figure 6 The first cutting edge part 5 has an arc-shaped first cutting edge 501, the first cutting edge 501 is formed at the intersection of the first inner side face 501 and the outer peripheral arm face 15, and the first cutting edge 501 extends from front to back to a vertex. The second cutting edge part 6 has a second cutting edge 601, the second cutting edge 601 is formed at the intersection of the second inner side face 602 and the outer peripheral arm face 15, and the vertex of the second cutting edge 601 is located at the front part of the second cutting edge. It should be pointed out that for different processing needs, the first cutting edge and the second cutting edge can also be configured in the same form, for example, when the drill tip is mainly used for softwood processing, the first cutting edge and the second cutting edge can be configured in the form of extending from front to back to a vertex; and when the drill tip is mainly used for hardwood processing, the first cutting edge and the second cutting edge can be configured in the form of configuring the vertex of the cutting edge to the front part of the cutting edge.

[0036] It can be understood that when the drill point is used for drilling, the center positioning point drill 2 first contacts and cuts the wood after being inserted to a certain depth, and then the first cutting edge 501 cuts. It should be pointed out that the existing design of marking by a sharp point is not a true sense of blade cutting, and it is easy to wear and collapse. Based on the above embodiments, the design of the arc-shaped cutting edge can significantly reduce the wear of the cutting edge, and the cutting edge has higher strength and is not easy to collapse. Further, by forming two arc-shaped cutting edges with different heights, the wear of each cutting edge can be further reduced, thereby improving the overall service life of the cutting edge. Further, by configuring the first cutting edge and the second cutting edge in different forms, the drill point can be applied to more different types of wood drilling.

[0037] In some embodiments, referring to Figure 8 As shown, the height difference H1 between the vertex of the first cutting edge part and the main cutting edge is 0.2mm-0.4mm, the height difference H2 between the vertex of the second cutting edge part and the main cutting edge is 0.5mm-0.6mm, and the height difference H3 between the vertex of the center positioning point and the main cutting edge is 1mm-1.5mm. It can be understood that the above height differences are all based on the highest point of the main cutting edge as the reference point. Through the test comparison of the inventor, the configuration of the above height differences is more conducive to obtaining better cutting performance and cutting effect. It should be pointed out that within the above setting range, the height difference between the vertex of the second cutting edge part and the vertex of the first cutting edge can be configured to different values as needed to realize the distribution of the cutting stroke participated by the second cutting edge part and the second cutting edge part. Specifically, if the second cutting edge part needs to participate more in cutting, the height difference between the vertex of the second cutting edge part and the vertex of the first cutting edge part can be configured to be larger, and vice versa, if the first cutting edge part needs to participate more in cutting, the height difference can be configured to be smaller.

[0038] In some embodiments, the height of the main cutting edge 3 gradually decreases from the side adjacent to the center positioning point to the outside, and forms an inclination angle of 1-3°. Specifically, taking the drill point shown in Figure 8 As an example, the inclination angle A formed by the line connecting the innermost end point of the main cutting edge and the outermost end point and the horizontal line is 1-3°.

[0039] It can be understood that based on the present embodiment, the drilling guiding property is improved, the radial runout is reduced, the drilling stability is improved, and the drilling process is smoother, and the overall resistance borne by the main cutting edge is reduced.

[0040] The embodiment of the present application also provides a drill bit, which comprises a drill rod and the drill point described in the above embodiments mounted on the drill rod.

[0041] In some embodiments, referring to Figure 5The drill bit shown comprises a drill rod 20 and a drill tip 1 mounted on the drill rod 20 Figure 3 The drill tip 1 shown. In other embodiments, refer to Figure 9 The drill bit shown comprises a drill rod 20 and a drill tip 1 mounted on the drill rod 20 Figure 6 The drill tip 1 shown. In other embodiments, refer to

[0042] As a preferred embodiment, the bottom end of the main body of the drill tip is formed with a protruding welding portion 19, the end face of the first end of the drill rod 20 is configured as a welding face 21, the welding face 21 is formed with a groove 22 matched with the welding portion 19, and the bottom end of the drill tip is welded with the welding face 21 of the drill rod.

[0043] It can be understood that in the existing woodworking drill bit that combines the drill tip and the drill rod by welding, the bottom end of the drill tip is generally configured as a conical surface, and the welding face of the drill rod is configured as a concave surface matched with the conical surface. Based on the design structure, a certain degree of misalignment (i.e. the chip flutes 13 of the drill tip and the drill rod chip flutes deviate) is prone to occur in the welding process of the drill tip and the drill rod, and then the rake face of the cutting structure needs to be ground after the welding of the drill tip and the drill rod is completed. Based on the above setting mode of the present application, the welding positioning accuracy and stability can be greatly improved, the problem of welding misalignment is better avoided, and then the rake face of the cutting structure does not need to be ground after the welding is completed, thereby greatly improving the drilling manufacturing efficiency and significantly reducing the manufacturing cost.

[0044] In the description of the embodiments of the present application, it should be understood that the terms "front", "back", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the components referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0045] In the description of the embodiments of the present application, the terms "first", "second", "third" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

[0046] In the description of the embodiments of the present application, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0047] Reference throughout this application to "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrases "in some embodiments," "in other embodiments," or similar phrases in various places in the specification are not necessarily all referring to the same embodiment, but can refer to one or more, but not all, embodiments, unless otherwise indicated. The terms "including," "has," "having," and variants thereof, are meant to be broad and encompass the terms "consisting of" and "consisting essentially of," unless otherwise indicated.

[0048] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since the scope of the application is defined with respect to the appended claims.

Claims

1. A drill tip, comprising a body, characterized in that, The top of the main body has a central positioning tip and at least three cutting structures, each of which includes: The main cutting edge is adjacent to the center locating tip and extends outward from the bottom of the center locating tip, and the main cutting edge is located at the intersection of the rake face and the flank face; The cutting edge is located at the outer edge of the back face; A chip-collecting groove and a chip-removing groove are formed between two adjacent cutting structures. The chip-collecting groove and the chip-removing groove are connected and extend into the central positioning tip. The apex of the central positioning tip is higher than the apex of the cutting edge, and the apex of the cutting edge is higher than the main cutting edge.

2. The drill bit according to claim 1, characterized in that: The central positioning tip has a pyramidal structure, and the chip groove extends into the conical surface of the central positioning tip. An inner edge is formed at the intersection of the chip groove and the conical surface.

3. The drill bit according to claim 2, characterized in that: The main cutting edge includes an inner cutting edge and an outer cutting edge. The outer cutting edge is an arc-shaped cutting edge and is adjacent to the inner cutting edge. The inner cutting edge is a straight cutting edge and is adjacent to the bottom of the center positioning tip. The inner cutting edge is located at the intersection of the back face of the rear cutting structure and the chip groove of the front cutting structure.

4. The drill bit according to claim 3, characterized in that: The height of the main cutting edge gradually decreases outward from the side adjacent to the center positioning tip, forming an inclination angle of 1-3°.

5. The drill bit according to claim 1, characterized in that: The cutting edge includes a first cutting edge and a second cutting edge arranged at a distance from each other. The first cutting edge is located between the main cutting edge and the second cutting edge, and the apex of the second cutting edge is higher than the apex of the first cutting edge.

6. The drill bit according to claim 5, characterized in that: The flank face includes a first flank face and a second flank face, the first flank face being higher than the second flank face; the first cutting edge is disposed on the first flank face, and the second cutting edge is disposed on the second flank face.

7. The drill bit according to claim 5, characterized in that: Both the first and second cutting edges are formed with arc-shaped cutting edges.

8. The drill bit according to claim 5, characterized in that: The height difference between the vertex of the first cutting edge and the main cutting edge is 0.2mm-0.4mm, the height difference between the vertex of the second cutting edge and the main cutting edge is 0.5mm-0.6mm, and the height difference between the center positioning tip and the main cutting edge is 1mm-1.5mm.

9. A drill bit, characterized in that, It includes a drill pipe and a drill tip according to any one of claims 1-8 mounted on the drill pipe.

10. The drill bit according to claim 9, characterized in that, The bottom end of the main body of the drill tip has a protruding welded part, the drill rod has a welded surface, and a groove matching the welded part is formed on the welded surface. The bottom end of the drill tip is welded to the welded surface of the drill rod.

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