Drill tool with stable radial clamping

Abstract

To provide a drilling tool featuring stable radial clamping, characterized by superior connection strength, high machining precision, convenient assembly / disassembly, long lifespan, and low production cost.SOLUTION: A clamping member comprises a handle part 21 and a clamping part 22. Two chip discharging grooves are formed in the clamping part to form a two-piece clamping structure. A cutting member is matched with the clamping part, and in a direction away from a cutting part along a rotation center axis of a drilling tool, a connecting part is sequentially provided with a first outer circumferential surface and a second outer circumferential surface, and the clamping part is sequentially provided with a first inner circumferential surface and a second inner circumferential surface. The first inner circumferential surface is matched with the first outer circumferential surface to form a first radial clamping structure, and the second inner circumferential surface is matched with the second outer circumferential surface to form a second radial clamping structure. The first radial clamping structure and the second radial clamping structure are capable of independently achieving radial clamping of the cutting member by the clamping member, and an interference amount of the first radial clamping structure is greater than that of the second radial clamping structure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates primarily to the field of metal cutting, and in particular to drill tools with stable radial clamping. [Background technology]

[0002] In drilling, expensive hard materials are often used for the cutting edge to extend the service life of the cutting part. Such materials are hard and wear-resistant, but are very difficult to process. This results in high material and processing costs for the drill tool.

[0003] To address this issue, conventional drilling tools typically employ a separate structure consisting of a cutting part and a clamping part. The cutting part is made of a highly hard, wear-resistant hard alloy, while the clamping part is made of a highly elastic material. This allows only the cutting part to be replaced when it wears out, reducing drilling costs. Such drilling tools typically have a two-piece clamping structure, and the clamping mechanism uses elastic deformation to create a small included angle for clamping and positioning. Due to the small included angle, conventional assembly of the cutting and clamping parts often uses a single clamping unit to connect the cutting and clamping parts. This limits the clamping area and force between the cutting and clamping parts, resulting in low connection accuracy and strength, which does not meet the requirements for high-precision, long-diameter drilling. Another drawback is that the single clamping unit is subject to stress, making the clamping part susceptible to fatigue and damage, resulting in a shortened tool life.

[0004] A drilling tool with stable clamping is proposed, for example, in Chinese Patent Document CN109262027A. The interference between the outer peripheral surface of the cutting element and the inner peripheral surface of the clamping element varies, and the correspondence (assembly, fitting) between the outer peripheral surface and the inner peripheral surface essentially refers to fitting with a certain interference in the gap between the inner hole wall and the outer cylinder. While the prior art can achieve clamping of the cutting element by the clamping element, the cutting element and the clamping element are connected using a single clamping unit, which limits the clamping area, making it difficult to ensure clamping accuracy and strength, and making the clamping element susceptible to fatigue wear. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to solve the shortcomings of the prior art and provide a drilling tool with stable radial clamping, which has good connection strength, high processing precision, convenient assembly and disassembly, long service life, and low manufacturing costs. [Means for solving the problem]

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions.

[0007] Compared with the prior art, the features and advantages of the present invention are as follows:

[0008] The present invention provides a drill tool with stable radial clamping, comprising a cutting member and a clamping member, wherein the cutting member comprises a cutting portion and a connecting portion, the clamping member comprises a gripping portion and a clamping portion, and the clamping portion is provided with two chip discharge grooves to form a two-plate clamp structure, the cutting member and the clamping portion correspond to each other, and the connecting portion has a first outer peripheral surface and a second outer peripheral surface in sequence in a direction away from the cutting portion on the rotational axis of the drill tool, and The clamping portion sequentially comprises a first inner peripheral surface and a second inner peripheral surface, the first inner peripheral surface and the first outer peripheral surface combine to form a first radial clamping structure, and the second inner peripheral surface and the second outer peripheral surface combine to form a second radial clamping structure, the first radial clamping structure and the second radial clamping structure independently realize that the clamping member clamps the cutting member along the radial direction, and the interference of the first radial clamping structure is greater than the interference of the second radial clamping structure.

[0009] Furthermore, the present invention provides further improved technical solutions as follows:

[0010] The first radial clamping structure has an interference λ1, and the second radial clamping structure has an interference λ2, which satisfy the relationship 0.005 mm≦λ1−λ2≦0.02 mm.

[0011] The length of the first outer surface along the central axis of rotation of the drill tool is L1, and the length of the second outer surface along the central axis of rotation of the drill tool is L2, which satisfy the relationship 0.2 mm≦L1-L2≦1.5 mm.

[0012] In an axial cross section of the drill tool, the angle between the first outer peripheral surface and the rotation axis of the drill tool is α1, and the angle between the first inner peripheral surface and the rotation axis of the drill tool is α2, which satisfy the relationship 0°<α1-α2<1°.

[0013] α2 is 0.

[0014] In any axial cross-section of the drill tool, the second outer peripheral surface is parallel to the rotation center axis, and the second inner peripheral surface is parallel to the rotation center axis.

[0015] A circumferential surface recess is provided between the first outer peripheral surface and the second outer peripheral surface, a circumferential surface protrusion is provided between the first inner peripheral surface and the second inner peripheral surface, and the circumferential surface recess and the circumferential surface protrusion correspond to each other.

[0016] The circumferential surface recess includes a recess upper side surface, a recess bottom surface, and a recess lower side surface that are sequentially arranged. The circumferential surface protrusion includes a protrusion upper side surface, a protrusion top surface, and a protrusion lower side surface that are sequentially arranged. The recess bottom surface and the protrusion top surface are combined to form a third radial clamping structure.

[0017] In the axial cross-section of the drill tool, the angle formed between the recess upper side surface and the recess lower side surface is β1, and the angle formed between the protrusion upper side surface and the protrusion lower side surface is β2, satisfying the relationship of 45° ≤ β1 ≤ 60° and 45° ≤ β2 ≤ 60°.

[0018] A cutting part end surface is provided on the cutting part, a clamping part end surface is provided on the clamping part. When the cutting member and the clamping member are assembled at a predetermined position, there is a gap T1 between the cutting part end surface and the clamping part end surface, and there is a gap T2 between the recess lower side surface and the protrusion lower side surface, satisfying the relationship of 0 < T2 - T1 < 0.2 mm.

[0019] A retreat outer peripheral surface is provided on the connection part. The retreat outer peripheral surface is closer to the rotation center axis than the second outer peripheral surface. A retreat inner peripheral surface is provided on the clamping part. The retreat inner peripheral surface is farther from the rotation center axis than the second inner peripheral surface.

Advantages of the Invention

[0020] The drill tool with stable radial clamping (stable radial clamp drill tool) of the present invention includes two radial clamping structures. The two radial clamping structures are arranged along the axial direction, gradually moving away from the cutting portion. The clamping interference of the first radial clamping structure is greater than that of the second radial clamping structure. That is, the first clamping structure has a stronger clamping force than the second clamping structure, and the second clamping structure has a larger clamping area than the first clamping structure. By combining the two radial clamping structures, the clamping area and clamping force after assembly between the clamping member and the cutting member can be increased, improving the connection strength of the drill tool. This allows for maintaining good drilling accuracy even under machining conditions such as long diameters and high feed rates. Furthermore, the two radial clamping structures have different clamping interferences, and the clamping interference of the first clamping structure is greater than that of the second clamping structure, making assembly easier and effectively reducing the difficulty of manufacturing the drill tool. Furthermore, by installing a double clamping structure (two clamping structures), deflection of the cutting member due to unstable clamping can be suppressed, fatigue damage to the clamping member can be significantly reduced, and the tool life can be extended. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a three-dimensional structural view of a drill tool according to the present invention, which has stable radial clamping. [Figure 2] 1 is a three-dimensional structural view of a cutting member of a drill tool according to the present invention, which has stable radial clamping. [Figure 3] 1 is a front view of a cutting element of a drill tool with stable radial clamping of the present invention; FIG. [Figure 4] FIG. 4 is an enlarged view of a portion A in FIG. 3. [Figure 5] 1 is a three-dimensional structural view of a drill tool connecting member according to the present invention, which is stable in radial clamping. [Figure 6] 1 is a front view of a drill tool connection member with stable radial clamping of the present invention; FIG. [Figure 7] FIG. 7 is a cross-sectional view of FIG. 6 taken along line B-B. [Figure 8] FIG. 8 is an enlarged view of a portion C in FIG. 7. [Figure 9] 1 is a front view of a radially stable clamping drill tool of the present invention; FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along the line DD in FIG. 9. [Figure 11] FIG. 11 is an enlarged view of a portion E in FIG. [Figure 12] FIG. 10 is a cross-sectional view of FIG. [Explanation of symbols]

[0022] 1: cutting member; 11: cutting portion; 111: cutting portion end surface; 12: connecting portion; 121: first outer peripheral surface; 122: second outer peripheral surface; 123: peripheral recess; 1231: recess upper surface; 1232: recess bottom surface; 1233: recess lower surface; 124: retracted outer peripheral surface; 2: clamping member; 21: gripping portion; 22: clamping portion; 221: first inner peripheral surface; 222: second inner peripheral surface; 223: peripheral convex portion; 2231: convex upper surface; 2232: convex top surface; 2233: convex lower surface; 224: clamping portion end surface; 225: retracted inner peripheral surface; 4: chip discharge groove; 5: rotation center axis DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0024] Terms indicating orientation or position, such as "center," "upper," "lower," "horizontal," "inner," "outer," "top," and "bottom," used in the detailed description of the present invention, can be understood based on the orientation or positional relationship shown in the drawings. Note that these descriptions are descriptions that explain a simplified structure for understanding the structure of the present invention, and related structures or parts are not necessarily limited to being disposed in their specific positions or to performing specific orientations, structures, and specific operations. In other words, these descriptions are not intended to limit the present invention.

[0025] 1 to 12 show an embodiment of a drill tool of the present invention that provides stable radial clamping. The drill tool includes a cutting member 1 and a clamping member 2. The cutting member 1 includes a cutting portion 11 and a connecting portion 12. The clamping member 2 includes a gripping portion 21 and a clamping portion 22. The clamping portion 22 is provided with two chip discharge grooves 4, forming a two-plate clamp structure. The cutting member 1 and the clamping portion 22 are arranged in correspondence with each other (they have corresponding shapes and fit together). The connecting portion 12 includes a first outer peripheral surface 121 and a second outer peripheral surface 122, facing away from the cutting portion 11 along the rotation axis 5 of the drill tool. The clamping portion 22 includes a first inner peripheral surface 221 and a second inner peripheral surface 222, facing away from the cutting portion 11 along the rotation axis 5 of the drill tool. The first inner peripheral surface 221 and the first outer peripheral surface 121 combine to form a first radial clamping structure, and the second inner peripheral surface 222 and the second outer peripheral surface 122 combine to form a second radial clamping structure. The first radial clamping structure and the second radial clamping structure enable the clamping member 2 to clamp the cutting member 1 in the radial direction, and the interference of the first radial clamping structure is greater than the interference of the second radial clamping structure. Two sets of radial clamping structures are provided, and the two sets of radial clamping structures are arranged along the axial direction so as to gradually move away from the cutting portion 11, and the interference of the first radial clamping structure is greater than the second radial clamping structure. As a result, the clamping force of the first clamping structure is greater than that of the second clamping structure, and the second clamping structure has a larger clamping area than the first clamping structure. The combination of two sets of radial clamping structures increases the clamping area and clamping force when the clamping member 2 and cutting member 1 are assembled, improving the connection strength of the drill tool and achieving good drilling accuracy even under long diameter and high feed operating conditions. Furthermore, the two sets of radial clamping structures have different interferences, and the interference of the first clamping structure is larger than that of the second clamping structure, making installation and assembly easier and reducing the difficulty of manufacturing the drill tool. Furthermore, the installation of a double clamping structure effectively prevents deflection of the cutting member 1 due to unstable clamping, significantly reducing fatigue damage to the clamping member 2 and improving the tool's lifespan.

[0026] In this embodiment, the first radial clamping structure has an interference λ1, and the second radial clamping structure has an interference λ2. When assembled in a predetermined position, the clamping member 2 opens (has) a slight included angle. Because the first inner circumferential surface 221 is farther from the support point than the second inner circumferential surface 222, the opening amount of the first inner circumferential surface 221 is greater than the opening amount of the second inner circumferential surface 222. To ensure clamping between the first radial clamping structure and the second clamping structure, the relationship between λ1 and λ2 is 0.005 mm≦λ1-λ2≦0.02 mm. In this embodiment, λ1=0.015 mm, and λ2=0.01 mm.

[0027] In this embodiment, the length of the first outer peripheral surface 121 along the rotation axis 5 of the drill tool is L1, and the length of the second outer peripheral surface 122 along the rotation axis 5 of the drill tool is L2. To allow the clamping area (area) to be concentrated in the first clamping structure, the relationship between L1 and L2 is set to 0.2 mm≦L1-L2≦1.5 mm. In this embodiment, L1=3.5 mm, and L2=3 mm.

[0028] In this embodiment, in an axial cross section of the drill tool, the angle between the first outer peripheral surface 121 and the rotation axis 5 of the drill tool is α1, and the angle between the first inner peripheral surface 221 and the rotation axis 5 of the drill tool is α2. To increase the clamping area of ​​the first clamping structure, there is a slight angle difference between the first inner peripheral surface 221 and the first outer peripheral surface 121, and to offset the small included angle when the clamping members 2 are open, α1 and α2 must satisfy the relationship 0°<α1-α2<1°. In this embodiment, α1=0.5°, and α2=0°.

[0029] In this embodiment, α2=0, that is, in the axial cross section of the drill tool, the first inner circumferential surface 221 and the rotation center axis 5 of the drill tool are arranged parallel to each other, which reduces the difficulty of manufacturing the tool.

[0030] In this embodiment, in any axial cross section of the drill tool, the second outer peripheral surface 122 is parallel to the rotation central axis 5, and the second inner peripheral surface 222 is parallel to the rotation central axis 5. This reduces the difficulty of manufacturing the tool.

[0031] In this embodiment, a circumferential surface recess 123 is provided between the first outer circumferential surface 121 and the second outer circumferential surface 122, a circumferential surface protrusion 223 is provided between the first inner circumferential surface 221 and the second inner circumferential surface 222, and the circumferential surface recess 123 and the circumferential surface protrusion 223 correspond to each other (the shapes correspond and they fit together).

[0032] In this embodiment, the circumferential surface recess 123 includes a recess upper side surface 1231, a recess bottom surface 1232, and a recess lower side surface 1233 arranged in sequence, and the circumferential surface protrusion 223 includes a protrusion upper side surface 2231, a protrusion top surface 2232, and a protrusion lower side surface 2233 arranged in sequence. The recess bottom surface 1232 and the protrusion top surface 2232 are combined to form a third radial clamping structure. Thereby, the connection strength and positioning accuracy of the tool can be further improved.

[0033] In this embodiment, in the axial cross-section of the drill tool, the angle between the recess upper side surface 1231 and the recess lower side surface 1233 is β1, and the angle between the protrusion upper side surface 2231 and the protrusion lower side surface 2233 is β2. In order to facilitate manufacturing and assembly, β1 and β2 are set to 45° ≤ β1 ≤ 60°, 45° ≤ β2 ≤ 60°. In this embodiment, β1 = β2 = 45°.

[0034] In this embodiment, a cutting part end face 111 is provided on the cutting part 11, a clamping part end face 224 is provided on the clamping part 22. When the cutting member 1 and the clamping member 2 are assembled, there is a gap T1 between the cutting part end face 111 and the clamping part end face 224, and there is a gap T2 between the recess lower side surface 1233 and the protrusion lower side surface 2233. In order to reduce the difficulty of tool manufacturing and make the gap between the cutting part end face 111 and the clamping part end face 215 of the drill tool zero, T1 and T2 are set to 0 < T2 - T1 < 0.2 mm. In this embodiment, T2 = 0.3 mm and T1 = 0.1 mm are exemplified.

[0035] In this embodiment, the connecting portion 12 is provided with a retracted outer peripheral surface 124, which is closer to the rotation axis 5 than the second outer peripheral surface 122. The clamping portion 22 is provided with a retracted inner peripheral surface 225, which is positioned farther from the rotation axis 5 than the second inner peripheral surface 222. This allows the cutting member 1 to be inserted into the clamping member 2 smoothly and accurately during assembly.

[0036] The above describes the preferred embodiments of the present invention, but this is not intended to limit the present invention. Those skilled in the art can make various changes and improvements to the technical means of the present invention with reference to the above embodiments without departing from the scope of the technical solutions of the present invention, and all such changes and improvements are equivalent to the embodiments of the present invention. Therefore, without departing from the content of the technical solutions of the present invention, any simple changes, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A drill tool with stable radial clamping, comprising a cutting member (1) and a clamping member (2), The cutting member (1) comprises a cutting portion (11) and a connecting portion (12), The clamping member (2) includes a gripping portion (21) and a clamping portion (22), The clamping portion (22) is provided with two chip discharge grooves (4), thereby forming a two-plate clamp structure, and the cutting member (1) and the clamping portion (22) correspond to each other; Along the rotational center axis (5) of the drill tool, the connecting portion (12) has a first outer peripheral surface (121) and a second outer peripheral surface (122) in that order in a direction away from the cutting portion (11); Along the rotational center axis (5) of the drill tool, the clamping portion (22) has a first inner peripheral surface (221) and a second inner peripheral surface (222) in that order in a direction away from the cutting portion (11), a first inner peripheral surface (221) and a first outer peripheral surface (121) combined together to form a first radial clamping structure, and a second inner peripheral surface (222) and a second outer peripheral surface (122) combined together to form a second radial clamping structure, the first radial clamping structure and the second radial clamping structure independently realize that the clamping member (2) clamps the cutting member (1) along the radial direction, and the interference of the first radial clamping structure is larger than the interference of the second radial clamping structure, the first radial clamping structure has an interference λ1, and the second radial clamping structure has an interference λ2, satisfying the relationship 0.005 mm≦λ1−λ2≦0.02 mm.

2. 2. The drill tool according to claim 1, wherein the length of the first outer peripheral surface (121) along the central axis of rotation (5) of the drill tool is L1, and the length of the second outer peripheral surface (122) along the central axis of rotation (5) of the drill tool is L2, and the relationship of 0.2 mm≦L1−L2≦1.5 mm is satisfied.

3. 3. The drill tool according to claim 1, wherein, in an axial cross section of the drill tool, an angle formed between the first outer peripheral surface (121) and a rotation center axis (5) of the drill tool is α1, an angle formed between the first inner peripheral surface (221) and a rotation center axis (5) of the drill tool is α2, and the relationship of 0°<α1-α2<1° is satisfied.

4. 4. The drill tool according to claim 3, wherein α2=0.

5. 4. The drill tool according to claim 3, characterized in that, in any cross section of the drill tool, the second outer peripheral surface (122) and the rotation central axis (5) are parallel to each other, and the second inner peripheral surface (222) and the rotation central axis (5) are parallel to each other.

6. 3. The drill tool according to claim 1, wherein a peripheral recess (123) is provided between the first outer peripheral surface (121) and the second outer peripheral surface (122), a peripheral protrusion (223) is provided between the first inner peripheral surface (221) and the second inner peripheral surface (222), and the peripheral recess (123) and the peripheral protrusion (223) correspond to each other.

7. 7. A drill tool with stable radial clamping as described in claim 6, characterized in that the peripheral recess (123) has a recess upper surface (1231), a recess bottom surface (1232), and a recess lower surface (1233) arranged in sequence, the peripheral convex portion (223) has a convex upper surface (2231), a convex top surface (2232), and a convex lower surface (2233) arranged in sequence, and the recess bottom surface (1232) and the convex top surface (2232) combine to form a third radial clamping structure.

8. A drill tool with stable radial clamping as described in claim 7, characterized in that, in an axial cross section of the drill tool, the angle between the upper surface (1231) of the recess and the lower surface (1233) of the recess is β1, and the angle between the upper surface (2231) of the convex portion and the lower surface (2233) of the convex portion is β2, and the relationships 45°≦β1≦60° and 45°≦β2≦60° are satisfied.

9. The drill tool with stable radial clamping described in claim 7, characterized in that the cutting portion (11) has a cutting portion end surface (111), the clamping portion (22) has a clamping portion end surface (224), and when the cutting member (1) and the clamping member (2) are assembled in a predetermined position, there is a gap T1 between the cutting portion end surface (111) and the clamping portion end surface (224), there is a gap T2 between the lower surface (1233) of the recess and the lower surface (2233) of the protrusion, and the relationship 0 < T2 - T1 < 0.2 mm is satisfied.

10. 3. The drill tool with stable radial clamping according to claim 2, characterized in that the connecting portion (12) is provided with a retracted outer peripheral surface (124) that is closer to the rotation center axis (5) than the second outer peripheral surface (122), and the clamping portion (22) is provided with a retracted inner peripheral surface (225) that is farther from the rotation center axis (5) than the second inner peripheral surface (222).

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