Drilling tool featuring 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 generally 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 part in order to extend the service life of the cutting part. Such materials are hard and have good wear resistance, but are very difficult to process. This causes problems such as high material costs and processing costs for the drill tool.

[0003] To solve this problem, conventional drill tools (hole drilling tools) generally adopt a divided structure consisting of a cutting part and a clamping part. The cutting part is made of a hard alloy or the like that is highly hard and resistant to wear, and the clamping part is made of a highly elastic material. When the cutting part is worn out, only the cutting part is replaced, which reduces the cost of drilling. Such drill tools generally consist of a two-piece clamp structure, and the clamping operation and positioning are realized by opening a small included angle using the elastic deformation of the clamping mechanism. Because of the small included angle, in the assembly of conventional cutting members and clamping members, a single clamping unit is often used to connect the cutting member and the clamping member. In this case, the clamping area and clamping force between the cutting member and the clamping member are limited, and the connection accuracy and strength are low, which is a problem that does not meet the work requirements for high-precision, long-diameter drilling. In addition, there is also a disadvantage that the single clamping unit is stressed, the clamping member is easily fatigued and damaged, and the tool life is shortened.

[0004] A drill tool with stable clamping is proposed, for example, in the Chinese patent document CN109262027A. The interference between the outer peripheral surface of the cutting member and the inner peripheral surface of the clamping member 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. The prior art can realize the clamping member clamping the cutting member, but the connection between the cutting member and the clamping member uses a single clamp unit, which limits the clamping area, making it difficult to ensure the clamping accuracy and strength, and the clamping member is prone 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 drill tool with stable radial clamping, which has good connection strength, high processing precision, convenient assembly and disassembly, long service life and low manufacturing cost. [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, the cutting member comprising a cutting portion and a connecting portion, the clamping member comprising a gripping portion and a clamping portion, and the clamping portion is provided with two chip discharge grooves to form a two-piece clamp structure, the cutting member and the clamping portion correspond to each other, and the connecting portion comprises a first outer circumferential surface and a second outer circumferential surface in the direction away from the cutting portion on the rotation axis of the drill tool, The clamping portion sequentially includes a first inner circumferential surface and a second inner circumferential surface, the first inner circumferential surface and the first outer circumferential surface combine to form a first radial clamping structure, and the second inner circumferential surface and the second outer circumferential 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 clamping margin of the first radial clamping structure is larger than the clamping margin of the second radial clamping structure.

[0009] In addition, 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, satisfying the relationship 0.005 mm≦λ1−λ2≦0.02 mm.

[0011] The length of the first outer peripheral surface along the central axis of rotation of the drill tool is L1, and the length of the second outer peripheral 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 central axis of rotation of the drill tool is α1, and the angle between the first inner peripheral surface and the central axis of rotation 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, the angle formed between the protrusion upper side surface and the protrusion lower side surface is β2, and the relationship 45° ≤ β1 ≤ 60°, 45° ≤ β2 ≤ 60° is satisfied.

[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, and the relationship 0 < T2 - T1 < 0.2 mm is satisfied.

[0019] A retracted outer peripheral surface is provided on the connecting part. The retracted outer peripheral surface is closer to the rotation center axis than the second outer peripheral surface. A retracted inner peripheral surface is provided on the clamping part. The retracted 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 has two sets of radial clamping structures, the two sets of radial clamping structures are arranged along the axial direction gradually moving away from the cutting part, and the clamping margin of the first radial clamping structure is larger 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 sets of radial clamping structures, the clamping area and clamping force after assembly of the clamping member and the cutting member can be increased, and the connection strength of the drill tool can be improved. This makes it possible to maintain good drilling accuracy even under machining conditions such as long diameter and high feed. In addition, the two sets of radial clamping structures have different clamping margins, and the clamping margin of the first clamping structure is larger than that of the second clamping structure, so that assembly is easy and the difficulty of manufacturing the drill tool can be effectively reduced. Furthermore, by installing a double clamp structure (two clamping structures), deflection of the cutting member caused by unstable clamping can be suppressed, fatigue damage to the clamping member can be significantly reduced, and the tool life can be extended. [Brief description 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. [Diagram 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. [Diagram 3] FIG. 2 is a front view of the cutting member of the radially stable clamping drill tool of the present invention; [Figure 4] FIG. 4 is an enlarged view of a portion A in FIG. [Diagram 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] FIG. 2 is a front view of the drill tool connection member with stable radial clamping of the present invention; [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. [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. [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: connection 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 protrusion; 2231: protrusion upper surface; 2232: protrusion top surface; 2233: protrusion lower surface; 224: clamping portion end surface; 225: retracted inner peripheral surface; 4: chip discharge groove; 5: rotation center axis DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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" described 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 for explaining 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, that is, these descriptions are not intended to limit the present invention.

[0025] 1 to 12 show an embodiment of the drill tool of the present invention with stable radial clamping. The drill tool with stable radial clamping 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 to form a two-piece clamp structure. The cutting member 1 and the clamping portion 22 are arranged corresponding to each other (they have corresponding shapes and fit together), and the connecting portion 12 includes a first outer peripheral surface 121 and a second outer peripheral surface 122, which face in a direction away from the cutting portion 11 along the rotation center axis 5 of the drill tool, and the clamping portion 22 includes a first inner peripheral surface 221 and a second inner peripheral surface 222, which face in a direction away from the cutting portion 11 along the rotation center axis 5 of the drill tool. The first inner peripheral surface 221 and the first outer peripheral surface 121 are combined to form a first radial clamping structure, and the second inner peripheral surface 222 and the second outer peripheral surface 122 are combined to form a second radial clamping structure. The first radial clamping structure and the second radial clamping structure realize that the clamping member 2 clamps the cutting member 1 in the radial direction, and the clamping margin of the first radial clamping structure is larger than that 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 clamping margin of the first radial clamping structure is larger than that of the second radial clamping structure. As a result, the clamping force of the first clamping structure is larger 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 the cutting member 1 are assembled, improves the connection strength of the drill tool, and provides good drilling accuracy even under long diameter and high feed working conditions. In addition, the two sets of radial clamping structures have different clamping margins, and the clamping margin of the first clamping structure is larger than that of the second clamping structure, making it easier to install and assemble, and reducing the difficulty of manufacturing the drill tool. Furthermore, the installation of the double clamping structure effectively suppresses the deflection of the cutting member 1 caused by unstable clamping, greatly reducing fatigue damage of the clamping member 2, and improving the life of the tool.

[0026] In this embodiment, the first radial clamping structure has a clamping margin λ1, and the second radial clamping structure has a clamping margin λ2. When assembled in a predetermined position, the clamping member 2 opens (has) a slight included angle. Since 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 larger than the opening amount of the second inner circumferential surface 222. In order to ensure the clamping of the first radial clamping structure and the second clamping structure, the relationship between λ1 and λ2 is set to 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 circumferential surface 121 along the rotation axis 5 of the drill tool is L1, and the length of the second outer circumferential surface 122 along the rotation axis 5 of the drill tool is L2. Since the clamping area (area) can 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 the axial cross section of the drill tool, the angle between the first outer peripheral surface 121 and the rotation central axis 5 of the drill tool is α1, and the angle between the first inner peripheral surface 221 and the rotation central axis 5 of the drill tool is α2. In order 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 in order to offset the small included angle when the clamping member 2 opens, α1 and α2 need to satisfy the relationship of 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 central axis 5 of the drill tool are arranged to be parallel to each other. This reduces the difficulty of manufacturing the tool.

[0030] In this embodiment, in any axial cross section of the drill tool, the second outer circumferential surface 122 is parallel to the rotation central axis 5, and the second inner circumferential 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 surface 111 is provided on the cutting part 11, a clamping part end surface 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 surface 111 and the clamping part end surface 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 surface 111 and the clamping part end surface 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 central axis 5 than the second outer peripheral surface 122. The clamping portion 22 is provided with a retracted inner peripheral surface 225, which is disposed so as to be farther away from the rotation central axis 5 than the second inner peripheral surface 222. This allows the cutting member 1 to be smoothly and accurately inserted into the clamping member 2 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 solution 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 solution 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 be included in the protection scope of the technical solution 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), forming a two-piece 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, in sequence in a direction away from the cutting portion (11), a first outer peripheral surface (121) and a second outer peripheral surface (122); 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 drill tool with stable radial clamping, characterized in that the first inner circumferential surface (221) and the first outer circumferential surface (121) combine to form a first radial clamping structure, the second inner circumferential surface (222) and the second outer circumferential surface (122) combine to form a second radial clamping structure, the first radial clamping structure and the second radial clamping structure independently realize the clamping member (2) to clamp along the radial direction of the cutting member (1), and the clamping margin of the first radial clamping structure is larger than the clamping margin of the second radial clamping structure.

2. The drill tool with stable radial clamping as described in claim 1, characterized in that the first radial clamping structure has a clamping margin λ1, the second radial clamping structure has a clamping margin λ2, and the relationship of 0.005 mm≦λ1-λ2≦0.02 mm is satisfied.

3. The drill tool according to claim 1, characterized in that the length of the first outer peripheral surface (121) along the central axis (5) of rotation of the drill tool is L1, and the length of the second outer peripheral surface (122) along the central axis (5) of rotation of the drill tool is L2, satisfying the relationship: 0.2 mm≦L1-L2≦1.5 mm.

4. The drill tool according to any one of claims 1 to 3, characterized in that, in an axial cross section of the drill tool, an angle between the first outer peripheral surface (121) and a central axis of rotation (5) of the drill tool is α1, an angle between the first inner peripheral surface (221) and a central axis of rotation (5) of the drill tool is α2, and the relationship of 0°<α1-α2<1° is satisfied.

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

6. The drill tool according to claim 4, 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, and the second inner peripheral surface (222) and the rotation central axis (5) are parallel.

7. A drill tool with stable radial clamping as described in any one of claims 1 to 3, characterized in that a circumferential recess (123) is provided between the first outer peripheral surface (121) and the second outer peripheral surface (122), a circumferential protrusion (223) is provided between the first inner peripheral surface (221) and the second inner peripheral surface (222), and the circumferential recess (123) and the circumferential protrusion (223) correspond to each other.

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

9. A drill tool with stable radial clamping as described in claim 8, 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, satisfying the relationships 45°≦β1≦60° and 45°≦β2≦60°.

10. A drill tool with stable radial clamping as described in claim 8, characterized in that the cutting portion (11) is provided with a cutting portion end surface (111), the clamping portion (22) is provided with 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 of the recess (1233) and the lower surface of the convex portion (2233), and the relationship 0 < T2 - T1 < 0.2 mm is satisfied.

11. 4. The drill tool with stable radial clamping as described in claim 3, characterized in that the connection portion (12) is provided with a retracted outer peripheral surface (124) that is closer to the rotation central 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 central axis (5) than the second inner peripheral surface (222).

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