Drill bit

Abstract

The utility model provides a drill bit, and belongs to the technical field of machining tools. The drill bit comprises a body. A plurality of spiral grooves are formed in the periphery of the body at intervals; in the first spiral direction, the spiral groove comprises a first spiral groove section and a second spiral groove section, the groove wall of the first spiral groove section is a first cambered surface, and the groove wall of the second spiral groove section is a second cambered surface. According to the drill bit, the first spiral groove section is smoother relative to the second spiral groove section in the first spiral direction, so that the included angle between the groove contour of the first spiral groove section and the tangent point of the core diameter of the body is larger, namely the inflection point of the spiral groove contour is closer to the rear, displacement resistance along the front cutter face of the spiral groove in the chip forming process is reduced, and the cutting efficiency is improved. And the smoothness of upward discharging of the cuttings along the spiral groove is improved, so that the effects of avoiding accumulation and blockage of the cuttings and reducing the drilling torque are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of machining tools, and particularly relates to a drill bit. Background Art

[0002] In the aerospace field, especially for key components such as aircraft fuselages and aero-engines, a large number of light metals and composite metal laminated components are used to achieve the purpose of weight reduction and enhanced structural reliability. The extensive application of light metals and composite metal laminated components has brought a huge demand for assembly connection hole-making. Currently, there are mainly two types of problems in hole-making: Firstly, excessive cutting force and torque during the cutting process can cause deformation of the workpiece material, affecting the hole-making quality, and even leading to tool breakage and workpiece scrapping. Secondly, the metal chips generated during drilling will scrape the drilled composite material hole wall, causing damage, affecting the hole diameter accuracy and hole quality, and even having the risk of chip blockage. When using conventional hole-making tools to make holes in light metals and composite metal laminated components, defects such as chip blockage, over-tolerance of hole-making dimensional accuracy, and poor hole wall roughness often occur, which will directly affect the assembly accuracy and the physical and mechanical properties of the machined structural parts. Content of the Utility Model

[0003] In view of this, the purpose of the utility model is to overcome the deficiencies in the prior art and provide a drill bit.

[0004] The utility model provides the following technical solution: A drill bit, comprising:

[0005] A body, on the outer periphery of which are provided a plurality of spaced spiral grooves;

[0006] Along a first spiral direction, the spiral groove includes a first spiral groove section and a second spiral groove section. The groove wall of the first spiral groove section is a first arc surface, and the groove wall of the second spiral groove section is a second arc surface.

[0007] In some embodiments, the concave radian of the first arc surface is less than the concave radian of the second arc surface.

[0008] In some embodiments, the value range of the central angle α of the first spiral groove section is 50° ≤ α ≤ 60°.

[0009] In some embodiments, the value range of the central angle β of the second spiral groove section is 45° ≤ β ≤ 55°.

[0010] In some embodiments, the arc radius of the second spiral groove section is R1, and the radius of the body is R;

[0011] Wherein, R1 and R satisfy the relationship 0.5R ≤ R1 ≤ 0.8R.

[0012] In some embodiments, the included angle of the spiral groove is γ; wherein, the value range of γ is 94° ≤ γ ≤ 120°.

[0013] In some embodiments, along the axial direction of the body, one end of the body is provided with a tip cutting part;

[0014] The tip cutting part includes a plurality of inner edges and a plurality of outer edges. One ends of the plurality of inner edges are connected to form a first blade tip. One end of the outer edge is connected to one end of the inner edge, and the other end of the outer edge is connected to the side wall of the body to form a second blade tip.

[0015] In some embodiments, the vertex angle of the inner edge is α1, wherein, the value range of α1 is 55° ≤ α1 ≤ 67.5°.

[0016] In some embodiments, the vertex angle of the outer edge is α2, wherein, the value range of α2 is 75° ≤ α2 ≤ 90°.

[0017] In some embodiments, the outer diameter of the inner edge is D1, and the outer diameter of the body is D;

[0018] Wherein, the relationship between D1 and D satisfies the formula 0.375D ≤ D1 ≤ 0.8D.

[0019] In some embodiments, the vertex angle α1 of the inner edge is 55°, the vertex angle α2 of the outer edge is 75°, and the outer diameter of the inner edge is D1 = 0.375D;

[0020] Or the vertex angle α1 of the inner edge is 67.5°, the vertex angle α2 of the outer edge is 85°, and the outer diameter of the inner edge is D1 = 0.8D.

[0021] The embodiments of the present utility model have the following advantages: For the drill bit provided by the present utility model, along the first spiral direction, the first spiral groove section is smoother than the second spiral groove section, so that the included angle between the tangent point of the groove profile of the first spiral groove section and the core diameter of the body is larger, that is, the inflection point of the spiral groove profile is more backward, which is conducive to reducing the displacement resistance along the rake face of the spiral groove during the chip formation process, improving the smoothness of the chip discharging upward along the spiral groove, thereby achieving the effects of avoiding chip accumulation and blockage and reducing the drilling torque.

[0022] To make the above objects, features and advantages of the present utility model more obvious and understandable, the following specific preferred embodiments are given below and are described in detail in conjunction with the accompanying drawings. Description of the Drawings

[0023] To more clearly illustrate the technical solutions of the embodiments of the present utility model, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present utility model and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0024] Figure 1 The structural schematic diagram of a perspective view of a drill bit provided by some embodiments of the present utility model is shown;

[0025] Figure 2 The structural schematic diagram of another perspective view of a drill bit provided by some embodiments of the present utility model is shown;

[0026] Figure 3 The structural schematic diagram of a perspective view of a partially enlarged drill bit provided by some embodiments of the present utility model is shown.

[0027] Main element symbol description:

[0028] 100 - Body; 110 - Helical groove; 111 - First helical groove section; 112 - Second helical groove section; 120 - Tip cutting part; 121 - Inner edge; 122 - Outer edge; 300 - First cutting edge tip; 400 - Second cutting edge tip; 500 - Drill shank. Specific embodiments

[0029] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present utility model and should not be construed as limiting the present utility model.

[0030] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. On the contrary, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration.

[0031] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "linkage", "fixation" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0032] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, the meaning of "a plurality" is two or more, unless otherwise clearly and specifically defined.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of the template herein are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0034] As Figures 1 to 3 shown, some embodiments of the present utility model provide a drill bit, which is mainly applied to the hole machining of parts such as aircraft skins, wing beams, floor beams, and fuselage structural members, used to reduce the displacement resistance of the drill bit along the rake face of the groove during chip formation, improve the smoothness of chip discharge, avoid chip accumulation and blockage, so as to improve the drilling quality.

[0035] The drill bit includes a body 100.

[0036] Wherein, a plurality of spaced spiral grooves 110 are formed on the outer periphery of the body 100. The number of the spiral grooves 110 can be any value of two or more, and can be specifically set according to actual situations.

[0037] In this embodiment, the edges of the spiral grooves 110 are connected to the side wall of the body 100 to form back edges and cutting edges. The cutting edges can play a role in cutting the hole wall of the workpiece, so as to avoid the occurrence of burrs on the hole wall during the process of drilling the workpiece. At the same time, the back edges play a role in blocking and finishing the waste chips, avoiding the scattering of chips everywhere, so as to improve the processing quality of the workpiece.

[0038] Along the first helical direction, the helical groove 110 includes a first helical groove section 111 and a second helical groove section 112. The groove wall of the first helical groove section 111 is a smooth first arc surface, and the groove wall of the second helical groove section 112 is a smooth second arc surface. It should be noted that the first arc surface and the second arc surface are asymmetrically arranged.

[0039] In this embodiment, the groove surface of the first helical groove section 111 is smoother than that of the second helical groove section 112, that is, the first arc surface is smoother than the second arc surface, so that the angle between the groove profile of the helical groove 110 and the tangent point of the core diameter is smaller, that is, the groove profile of the second helical groove section 112 is farther back from the inflection point of the first helical groove section 111, which is more conducive to reducing the displacement resistance along the first helical direction during the chip formation process, improving the smoothness of the chip discharging upward along the helical groove 110, achieving the effect of avoiding chip accumulation and blockage and reducing the drilling torque, which can not only improve the cutting quality but also extend the service life of the drill bit.

[0040] Specifically, the concave radian of the first arc surface is smaller than that of the second arc surface, so that the second helical groove section 112 has a large concave radian and a large groove opening angle, which promotes the inward curling and convergence of the chip, has strong wrapping at the groove tail, and avoids the chip rubbing against the hole wall.

[0041] The drill bit provided by the present application, through the design of matching the smaller core diameter of the body 100 and the larger groove depth of the helical groove 110, makes the chip discharge groove of the helical groove 110 have a larger chip accommodation space, which is conducive to avoiding chip accumulation and blockage and achieving the purpose of improving the hole diameter stability.

[0042] It should be noted that the first helical direction refers to the rotational cutting direction when the drill bit drills a hole.

[0043] In some embodiments of the present invention, the central angle of the first helical groove section 111 is α, and the value range of α is 50° ≤ α ≤ 60°.

[0044] It can be understood that the value range of the central angle α of the first helical groove section 111 can be any range among 50° ≤ α ≤ 60°, 51° ≤ α ≤ 60°, 52° ≤ α ≤ 60°, 53° ≤ α ≤ 60°, 54° ≤ α ≤ 60°, 55° ≤ α ≤ 60°, 56° ≤ α ≤ 60°, 57° ≤ α ≤ 60°, 58° ≤ α ≤ 60° and 59° ≤ α ≤ 60°.

[0045] In some embodiments of the present invention, the arc radius of the second helical groove section 112 is R1, and the radius of the body 100 is R. Among them, the relationship between R1 and R satisfies the formula 0.5R ≤ R1 ≤ 0.8R.

[0046] It can be understood that the relationship satisfied between R1 and R can be any one of 0.5R ≤ R1 ≤ 0.8R, 0.6R ≤ R1 ≤ 0.8R, and 0.7R ≤ R1 ≤ 0.8R, which can be specifically set according to the actual situation.

[0047] In some embodiments of the present utility model, the included angle of the spiral groove 110 is γ, wherein the value range of γ is 94° ≤ γ ≤ 120°.

[0048] It can be understood that the value range of γ can be any one of 94° ≤ γ ≤ 120°, 100° ≤ γ ≤ 120°, 105° ≤ γ ≤ 120°, 110° ≤ γ ≤ 120°, 115° ≤ γ ≤ 120°.

[0049] Such as Figure 2 and Figure 3 As shown, in some embodiments of the present utility model, along the axial direction of the body 100, one end of the body 100 is provided with a tip cutting portion 120.

[0050] Wherein, the tip cutting portion 120 includes a plurality of inner cutting edges 121 and a plurality of outer cutting edges 122. One ends of the plurality of inner cutting edges 121 are connected to form a first cutting tip 300. The other ends of the plurality of inner cutting edges 121 are arranged at intervals. And one end of the outer cutting edge 122 is connected to the end of the inner cutting edge 121 far from the first cutting tip 300, and the other end of the outer cutting edge 122 is connected to the side wall of the body 100 to form a second cutting tip 400.

[0051] It should be noted that the distances between the ends of two adjacent inner cutting edges 121 far from the first cutting tip 300 are equal. In this way, during the process of the first cutting portion drilling the workpiece, the uniformity of the inner cutting edge 121 drilling the workpiece can be ensured, so as to ensure the consistency of the size of the waste chips generated during the drilling process. At the same time, the uniformity of the force on each inner cutting edge 121 can be ensured, thereby ensuring the service life of the first cutting edge and the processing quality of the workpiece.

[0052] In some embodiments of the present utility model, the apex angle of the inner cutting edge 121 is α1, wherein the value range of α1 is 55° ≤ α1 ≤ 67.5°.

[0053] It can be understood that the value range of α1 can be any one of 55° ≤ α1 ≤ 67.5°, 60° ≤ α1 ≤ 67.5°, 65° ≤ α1 ≤ 67.5°, which can be specifically set according to the actual situation.

[0054] In addition, in some embodiments of the present utility model, the apex angle of the outer cutting edge 122 is α2, where the value range of α2 is 75° ≤ α2 ≤ 90°. Among them, the value range of α2 can be any one of 75° ≤ α2 ≤ 90°, 80° ≤ α2 ≤ 90°, 85° ≤ α2 ≤ 90°, and can be specifically set according to the actual situation.

[0055] In some embodiments of the present utility model, the outer diameter of the inner cutting edge 121 is D1, and the outer diameter of the body 100 is D. Among them, D1 and D satisfy the relational expression: 0.375D ≤ D1 ≤ 0.8D. It can be understood that the relational expression satisfied between D1 and D includes any one of 0.375D ≤ D1 ≤ 0.8D, 0.4D ≤ D1 ≤ 0.8D, 0.5D ≤ D1 ≤ 0.8D, 0.6D ≤ D1 ≤ 0.8D, 0.7D ≤ D1 ≤ 0.8D.

[0056] Specifically, in some embodiments of the present utility model, a drill bit is provided and marked as drill type 1. The apex angle α1 of the inner cutting edge 121 of the drill type 1 is 55°, the apex angle α2 of the outer cutting edge 122 is 75°, and the outer diameter D1 of the inner cutting edge 121 is 37.5% D.

[0057] In addition, another drill bit is provided in this embodiment and marked as drill type 2. The apex angle α1 of the inner cutting edge 121 of the drill type 2 is 67.5°, the apex angle α2 of the outer cutting edge 122 is 85°, and the outer diameter D1 of the inner cutting edge 121 is 80% D.

[0058] Table 1 Comparison of hole diameters in Example 1

[0059]

[0060]

[0061] Table 2 Comparison of cutting forces and torques in Example 1

[0062]

[0063] By drilling carbon plates with the conventional drill type and the drill type 1 and drill type 2 provided in this application respectively, it can be seen from Table 2 that the drill type 1 provided in this application weakens the axial force, has higher quality at the entrance and exit, and can break chips automatically. The scraping damage to the hole wall is reduced, the difference between the carbon plate exit hole diameter and the edge diameter is reduced, the cutting force is significantly reduced, and the torque reduction is small.

[0064] The drill type 2 provided in this application weakens the axial force and improves the quality at the entrance and exit. The chip shape becomes longer, and the proportion of long chips increases significantly. The chip removal process is smooth, the scraping damage to the hole wall is reduced, the difference between the carbon plate exit hole diameter and the edge diameter is reduced, and the cutting force and torque are significantly reduced.

[0065] In addition, some other embodiments of the present application provide a drill bit, which is marked as Drill Type 3. The central angle α of the first spiral groove section 111 of the drill type 2 is 55°, the arc radius of the second spiral groove section 112 is R1 = 0.7R, and the included angle of the spiral groove 110 is γ = 106°. When comparing this Drill Type 3 with a conventional drill bit, specific comparison data can be found in Tables 3 and 4.

[0066] Table 3 Comparison of Bore Diameters in Example 2

[0067]

[0068] Table 4 Comparison of Cutting Forces and Torques in Example 2

[0069]

[0070] As can be seen from Tables 3 and 4, when comparing Drill Type 3 with a conventional drill bit, the chip shape of the groove type of Drill Type 3 is still folded, but the extrusion degree is reduced, the chips become longer, the debris and short chips are reduced, the bore diameter at the carbon plate outlet tends to be stable, and the torque reduction is relatively large, about 40%.

[0071] It can be seen therefrom that through the groove type design of the spiral groove 110 in the present application, in cooperation with the core diameter of the body 100, the chip-containing space of the chip evacuation groove is larger, which is beneficial to avoiding chip accumulation and blockage, and achieving the purpose of improving the stability of the bore diameter.

[0072] As Figure 1 shown, in some embodiments of the present utility model, the drill bit includes a drill shank 500, and the drill shank 500 is disposed at one end of the body 100 away from the tip cutting portion 120.

[0073] In all the examples shown and described here, any specific value should be construed as merely exemplary, not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0074] It should be noted that: like reference numerals and letters denote like 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 subsequent drawings.

[0075] The above-described embodiments merely represent several implementation manners of the present utility model, and their descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the present utility model. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model.

Claims

1. A drill bit, characterized in that, Comprising: A body, on the outer periphery of which a plurality of spaced-apart spiral grooves are provided; Along a first spiral direction, the spiral groove includes a first spiral groove section and a second spiral groove section. The groove wall of the first spiral groove section is a first arc surface, and the groove wall of the second spiral groove section is a second arc surface.

2. The drill bit according to claim 1, characterized in that, The concave radian of the first arc surface is smaller than that of the second arc surface.

3. The drill bit according to claim 1, wherein The central angle of the first spiral groove section is α, where the value range of α is 50° ≤ α ≤ 60°.

4. The drill bit according to claim 1, characterized in that, The circular arc radius of the second spiral groove section is R1, and the radius of the body is R; Wherein, the relationship between R1 and R satisfies the formula 0.5R ≤ R1 ≤ 0.8R.

5. The drill bit according to claim 1, characterized in that, The included angle of the spiral groove is γ; where the value range of γ is 94° ≤ γ ≤ 120°.

6. The drill bit according to any one of claims 1 to 5, characterized in that, Along the axial direction of the body, a tip cutting part is provided at one end of the body; The tip cutting part includes a plurality of inner cutting edges and a plurality of outer cutting edges. One ends of the plurality of inner cutting edges are connected to form a first cutting tip. One end of the outer cutting edge is connected to one end of the inner cutting edge, and the other end of the outer cutting edge is connected to the side wall of the body to form a second cutting tip.

7. The drill bit according to claim 6, characterized in that, The vertex angle of the inner cutting edge is α1, where the value range of α1 is 55° ≤ α1 ≤ 67.5°.

8. The drill bit according to claim 7, characterized in that, The vertex angle of the outer cutting edge is α2, where the value range of α2 is 75° ≤ α2 ≤ 90°.

9. The drill bit according to claim 8, characterized in that, The outer diameter of the inner cutting edge is D1, and the outer diameter of the body is D; Wherein, the relationship between D1 and D satisfies the formula 0.375D ≤ D1 ≤ 0.8D.

10. The drill bit according to claim 9, characterized in that, The vertex angle α1 of the inner cutting edge is 55°, the vertex angle α2 of the outer cutting edge is 75°, and the outer diameter of the inner cutting edge is D1 = 0.375D; Or the vertex angle α1 of the inner cutting edge is 67.5°, the vertex angle α2 of the outer cutting edge is 85°, and the outer diameter of the inner cutting edge is D1 = 0.8D.

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