A split-type drilling tool

Abstract

The present invention discloses a split-type drilling tool, which comprises a cutting component and a clamping component. The cutting component includes a cutting part and a connecting boss, and the clamping component includes a shank part and a clamping groove. The connecting boss cooperates with the clamping groove to realize the connection between the cutting component and the clamping component. The outer peripheral surface of the connecting boss includes a large circumferential surface and a small circumferential surface arranged circumferentially. The large circumferential surface and the small circumferential surface have the same rotation central axis, and the rotation radius of the large circumferential surface is greater than that of the small circumferential surface. The inner wall of the clamping groove includes an inner large circumferential surface that cooperates with the large circumferential surface and an inner small circumferential surface that cooperates with the small circumferential surface. The present invention has the advantages of high positioning accuracy, convenient loading and unloading, long service life and low manufacturing cost, etc.

Description

Technical Field

[0001] The present invention mainly relates to the field of metal cutting, and particularly relates to a split drilling tool. Background Art

[0002] In drilling, in order to extend the service life of the cutting part, relatively expensive cemented carbide or similar materials are usually used as the tool material. Since such materials have the characteristics of high hardness and good wear resistance, the processing is extremely difficult, which makes the material cost and processing cost of the drilling tool relatively high.

[0003] To solve the above problems, the drilling tools in the prior art generally adopt a split structure, that is, they are assembled by a cutting part and a clamping part. Among them, the cutting part is made of cemented carbide or similar materials with high hardness and strong wear resistance, while the clamping part is made of materials with large elasticity. When the cutting part is worn, the cutting part can be replaced separately, thereby reducing the cost of drilling. However, such tools generally adopt a two-piece clamping structure, and use the elastic deformation of the clamping mechanism to open a small angle to achieve clamping and positioning. The positioning strength is not high, the cutting part is easy to fall off, and the service life of the clamping part is short.

[0004] Chinese Patent Document CN113953564A discloses a split drilling tool. When the cutting part and the clamping part are assembled, the positioning outer peripheral surface is inserted into the closed positioning groove along the axial direction through the clearance inner peripheral surface. After the cutting part rotates a certain angle circumferentially, the positioning outer peripheral surface and the positioning inner peripheral surface are in interference fit, and there is a changing interference amount between the positioning outer peripheral surface and the positioning inner peripheral surface during the circumferential rotation of the cutting part. Although it solves the problems that the two-piece elastic structure is prone to deformation during use, resulting in poor positioning accuracy and short service life of the clamping part, etc., the connecting part of this scheme has concave clamping grooves opened circumferentially and the connecting part is rotationally symmetric, resulting in low structural strength of the connecting part. Under harsh working conditions such as large feed and large torsion, the connecting part is easy to break. On the other hand, this scheme cannot limit the one-way assembly of the cutting part and the connecting part, and the assembly accuracy is poor. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a split drilling tool with high positioning accuracy, convenient loading and unloading, long service life and low manufacturing cost.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A split-type drilling tool includes a cutting component and a clamping component. The cutting component includes a cutting part and a connecting boss. The clamping component includes a shank and a clamping groove. The connecting boss cooperates with the clamping groove to connect the cutting component and the clamping component. The outer peripheral surface of the connecting boss includes a large circumferential surface and a small circumferential surface arranged circumferentially. The large circumferential surface and the small circumferential surface have the same rotation center axis. The rotation radius of the large circumferential surface is greater than the rotation radius of the small circumferential surface. The inner wall of the clamping groove includes an inner large circumferential surface that cooperates with the large circumferential surface and an inner small circumferential surface that cooperates with the small circumferential surface.

[0008] As a further improvement of the above technical solution:

[0009] The rotation radius of the large circumferential surface is R2, and the rotation radius of the small circumferential surface is R1, and it should satisfy: 0.6R2 < R1 < R2.

[0010] The rotation radius of the inner small circumferential surface is R3, and it should satisfy: R3 = R1.

[0011] The rotation radius of the inner large circumferential surface is R4, and it should satisfy: 0 < R4 - R2 < 0.5 mm.

[0012] On any cross-section perpendicular to the rotation center axis, the included angle formed by the connection lines between the two end points of the small circumferential surface and the rotation center axis is A, and the included angle formed by the connection lines between the two end points of the inner small circumferential surface and the rotation center axis is B, and it should satisfy: 120° ≤ A ≤ 180°, 120° ≤ B < 180°, 0° ≤ A - B ≤ 15°.

[0013] An outer connecting circumferential surface is provided between the large circumferential surface and the small circumferential surface. The outer connecting circumferential surface is tangent to the small circumferential surface. An inner connecting circumferential surface is provided between the inner large circumferential surface and the inner small circumferential surface. The inner connecting circumferential surface is tangent to the inner small circumferential surface.

[0014] The included angle C formed by the intersection of the vertical bisecting plane P of the connecting boss passing through the rotation center axis and the torque transmission surface of the cutting part should satisfy: 0° < C < 30°.

[0015] The circumradius of the circumcircle of the cutting edge tip of the cutting part is R5, and it should satisfy: 0.1R5 < R1 < 0.3R5.

[0016] A pin hole is provided on the side wall of the clamping groove. A fastener is installed in the pin hole. A recessed bayonet is provided on the large circumferential surface. When the cutting component and the clamping component are assembled in place, the end of the fastener cooperates with the recessed bayonet to lock the cutting component and the clamping component.

[0017] The recessed bayonet includes an upper bayonet surface, a bottom bayonet surface, and a lower bayonet surface. When the cutting component and the clamping component are assembled in place, the clearances between the fastener and the upper bayonet surface, the bottom bayonet surface, and the lower bayonet surface are t1, t2, and t3 respectively, and should satisfy: 0 < t1 < 0.5 mm, t2 = t3 = 0.

[0018] Compared with the prior art, the advantages of the present invention are as follows:

[0019] The split-type drilling tool of the present invention includes a cutting component and a clamping component. The cutting component includes a cutting part and a connecting boss, and the clamping component includes a shank and a clamping groove. The connecting boss cooperates with the clamping groove to realize the connection between the cutting component and the clamping component. The outer peripheral surface of the connecting boss includes a large circumferential surface and a small circumferential surface arranged circumferentially. The large circumferential surface and the small circumferential surface have the same rotation center axis, and the rotation radius of the large circumferential surface is greater than that of the small circumferential surface. The inner wall of the clamping groove includes an inner large circumferential surface that cooperates with the large circumferential surface and an inner small circumferential surface that cooperates with the small circumferential surface. The circumferential and radial positioning of the cutting component and the clamping component is realized through the cooperation of the small circumferential surface and the inner small circumferential surface, and the large circumferential surface and the inner large circumferential surface. Moreover, both the small circumferential surface and the inner small circumferential surface, and the large circumferential surface and the inner large circumferential surface can achieve a semi-circular positioning close to 180°. The contact area of the positioning surface is large, and there is no weak positioning area, thereby improving the positioning strength and accuracy, enabling the tool to still perform stable cutting under working conditions such as large feed and large torque, and greatly enhancing the versatility and service life of the tool. Description of the Drawings

[0020] Figure 1 is a three-dimensional structure diagram of the split-type drilling tool of the present invention.

[0021] Figure 2 is a three-dimensional structure diagram of the cutting component of the split-type drilling tool of the present invention.

[0022] Figure 3 is a three-dimensional structure diagram of the clamping component of the split-type drilling tool of the present invention.

[0023] Figure 4 is the front view of the split-type drilling tool of the present invention.

[0024] Figure 5 is Figure 4 the A-A view of

[0025] Figure 6 is Figure 5 the enlarged view at B in

[0026] Figure 7 is the side view of the split-type drilling tool of the present invention.

[0027] Figure 8 is Figure 4C-C view.

[0028] Figure 9 is Figure 8 Enlarged view of part D.

[0029] Each label in the figure represents:

[0030] 1. Cutting component; 11. Cutting part; 111. Torque transmission surface; 12. Connecting boss; 121. Small circumferential surface; 122. Large circumferential surface; 123. Outer connecting circumferential surface; 124. Recessed bayonet; 1241. Upper side surface of the bayonet; 1242. Bottom surface of the bayonet; 1243. Lower side surface of the bayonet; 2. Clamping component; 21. Handle; 22. Clamping groove; 221. Inner small circumferential surface; 222. Inner large circumferential surface; 223. Inner connecting circumferential surface; 23. Pin hole; 24. Chip removal groove; 3. Fastener; 4. Rotation center axis. Detailed implementation mode

[0031] The present invention will be further described in detail below with reference to the accompanying drawings of the specification and specific embodiments.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "horizontal", "inner", "outer", "top", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0033] Figures 1 to 9An embodiment of the split drilling tool of the present invention is shown. The split drilling tool includes a cutting component 1 and a clamping component 2. The cutting component 1 includes a cutting part 11 and a connecting boss 12. The clamping component 2 includes a shank part 21 and a clamping groove 22. The connecting boss 12 cooperates with the clamping groove 22 to realize the connection between the cutting component 1 and the clamping component 2. The outer peripheral surface of the connecting boss 12 includes a large circumferential surface 122 and a small circumferential surface 121 arranged circumferentially. The large circumferential surface 122 and the small circumferential surface 121 have the same rotation center axis 4. The rotation radius of the large circumferential surface 122 is greater than that of the small circumferential surface 121. The inner wall of the clamping groove 22 includes an inner large circumferential surface 222 that cooperates with the large circumferential surface 122 and an inner small circumferential surface 221 that cooperates with the small circumferential surface 121. The circumferential and radial positioning of the cutting component 1 and the clamping component 2 is realized through the cooperation of the small circumferential surface 121 and the inner small circumferential surface 221, and the large circumferential surface 122 and the inner large circumferential surface 222. Moreover, both the small circumferential surface 121 and the inner small circumferential surface 221, and the large circumferential surface 122 and the inner large circumferential surface 222 can achieve a semi-circular positioning close to 180°. The contact area of the positioning surface is large, and there is no weak positioning area, thereby improving the positioning strength and accuracy, enabling the tool to still cut stably under working conditions such as large feed and large torque, greatly enhancing the versatility and service life of the tool. The small circumferential surface 121, the inner small circumferential surface 221, the large circumferential surface 122, and the inner large circumferential surface 222 are all arc surfaces, and the large circumferential surface 122 and the small circumferential surface 121 have the same rotation center axis 4, reducing the processing difficulty of the connecting boss 12 and the clamping groove 22 and reducing the tool manufacturing cost.

[0034] The rotation radius of the large circumferential surface 122 is R2, and the rotation radius of the small circumferential surface 121 is R1. To ensure the positioning area of the connecting boss 12 and increase the cross-sectional area of the connecting boss 12 at the same time, it should satisfy: 0.6R2 < R1 < R2. In this embodiment, R1 = 1.4 mm and R2 = 1.6 mm.

[0035] In this embodiment, the rotation radius of the inner small circumferential surface 221 is R3. To ensure the cooperation accuracy between the connecting boss 12 and the clamping groove 22, it should satisfy: R3 = R1. In this embodiment, R3 = 1.4 mm.

[0036] The rotation radius of the inner large circumferential surface 222 is R4. To facilitate the loading and unloading of the cutting component 1 and the clamping component 2, it should satisfy: 0 < R4 - R2 < 0.5 mm. In this embodiment, R4 = 1.7 mm.

[0037] In this embodiment, on any cross-section perpendicular to the rotation center axis 4, the included angle formed by the connection lines between the two end points of the small circumferential surface 121 and the rotation center axis 4 is A, and the included angle formed by the connection lines between the two end points of the inner small circumferential surface 221 and the rotation center axis 4 is B. To ensure that the connecting boss 12 and the clamping groove 22 have sufficient positioning arc and ensure the positioning accuracy, it should satisfy: 120°≤A≤180°, 120°≤B<180°, 0°≤A - B≤15°. In this embodiment, A = 175° and B = 170°.

[0038] In this embodiment, an outer connecting circumferential surface 123 is provided between the large circumferential surface 122 and the small circumferential surface 121. The outer connecting circumferential surface 123 is tangent to the small circumferential surface 121. An inner connecting circumferential surface 223 is provided between the inner large circumferential surface 222 and the inner small circumferential surface 221. The inner connecting circumferential surface 223 is tangent to the inner small circumferential surface 221, which reduces the processing difficulty of the connecting boss 12 and the clamping groove 22. At the same time, it also avoids the generation of sharp points, reduces stress concentration, and improves the tool life.

[0039] The included angle C formed by the intersection of the vertical bisecting plane P of the connecting boss 12 passing through the rotation center axis 4 and the torque transmission surface 111 of the cutting part 11. To ensure that there is sufficient distance between the pin hole 23 and the chip removal groove 24 outside the clamping groove 22, it should satisfy: 0°<C<30°. In this embodiment, C = 5°.

[0040] The radius of the circumscribed circle of the cutting edge tip of the cutting part 11 is R5, and it should satisfy: 0.1R5<R1<0.3R5. In this embodiment, R5 = 9.5mm.

[0041] In this embodiment, a pin hole 23 is provided on the side wall of the clamping groove 22, and a fastener 3 is installed in the pin hole 23. A recessed bayonet 124 is provided on the large circumferential surface 122. When the cutting part 1 and the clamping part 2 are assembled in place, the end of the fastener 3 cooperates with the recessed bayonet 124 to realize the locking of the cutting part 1 and the clamping part 2.

[0042] In this embodiment, the recessed bayonet 124 includes a bayonet upper side surface 1241, a bayonet bottom surface 1242, and a bayonet lower side surface 1243. When the cutting part 1 and the clamping part 2 are assembled in place, the clearances between the fastener 3 and the bayonet upper side surface 1241, the bayonet bottom surface 1242, and the bayonet lower side surface 1243 are t1, t2, and t3 respectively. To ensure that there is no clearance between the axial force transmission surfaces of the cutting part 1 and the clamping part 2, it should satisfy: 0<t1<0.5mm, t2 = t3 = 0. In this embodiment, t1 = 0.2mm.

[0043] Although the present invention has been disclosed above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention, or modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present invention. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A split-type drilling tool, comprising a cutting component (1) and a clamping component (2). The cutting component (1) includes a cutting portion (11) and a connecting boss (12). The clamping component (2) includes a shank portion (21) and a clamping groove (22). The connecting boss (12) cooperates with the clamping groove (22) to realize the connection between the cutting component (1) and the clamping component (2). Characterized in that: The outer peripheral surface of the connecting boss (12) includes a large circumferential surface (122) and a small circumferential surface (121) arranged circumferentially. The large circumferential surface (122) and the small circumferential surface (121) have the same rotation central axis (4). The rotation radius of the large circumferential surface (122) is greater than that of the small circumferential surface (121). The inner wall of the clamping groove (22) includes an inner large circumferential surface (222) that cooperates with the large circumferential surface (122) and an inner small circumferential surface (221) that cooperates with the small circumferential surface (121). The small circumferential surface (121) and the inner small circumferential surface (221) have the same rotation central axis (4). On any cross-section perpendicular to the rotation central axis (4), the included angle formed by the connection lines between the two end points of the small circumferential surface (121) and the rotation central axis (4) is A, and it should satisfy: 120° ≤ A ≤ 180°. The cooperation between the large circumferential surface (122) and the inner large circumferential surface (222) and the cooperation between the small circumferential surface (121) and the inner small circumferential surface (221) can both achieve a semi-circular positioning close to 180°.

2. The split-type drilling tool according to claim 1, Characterized in that: The rotation radius of the large circumferential surface (122) is R2, and the rotation radius of the small circumferential surface (121) is R1, and it should satisfy: 0.6R2 < R1 < R2.

3. The split-type drilling tool according to claim 2, Characterized in that: The rotation radius of the inner small circumferential surface (221) is R3, and it should satisfy: R3 = R1.

4. The split-type drilling tool according to claim 3, Characterized in that: The rotation radius of the inner large circumferential surface (222) is R4, and it should satisfy: 0 < R4 - R2 < 0.5 mm.

5. The split-type drilling tool according to any one of claims 1 to 4, Characterized in that: On any cross-section perpendicular to the rotation central axis (4), the included angle formed by the connection lines between the two end points of the inner small circumferential surface (221) and the rotation central axis (4) is B, and it should satisfy: 120° ≤ B < 180°, 0° ≤ A - B ≤ 15°.

6. The split-type drilling tool according to any one of claims 1 to 4, Characterized in that: An outer connecting circumferential surface (123) is provided between the large circumferential surface (122) and the small circumferential surface (121). The outer connecting circumferential surface (123) is tangent to the small circumferential surface (121). An inner connecting circumferential surface (223) is provided between the inner large circumferential surface (222) and the inner small circumferential surface (221). The inner connecting circumferential surface (223) is tangent to the inner small circumferential surface (221).

7. The split-type drilling tool according to any one of claims 1 to 4, Characterized in that: The included angle C formed by the intersection of the vertical bisecting plane P of the connecting boss (12) passing through the rotation center axis (4) and the torque transmission surface (111) of the cutting part (11) should satisfy: 0° < C < 30°.

8. The split drilling tool according to any one of claims 2 to 4, characterized in that: The radius of the circumscribed circle of the cutting edge tip of the cutting part (11) is R5, and it should satisfy: 0.1R5 < R1 < 0.3R5.

9. The split drilling tool according to any one of claims 1 to 4, characterized in that: A pin hole (23) is provided on the side wall of the clamping groove (22), a fastener (3) is installed in the pin hole (23), a recessed bayonet (124) is provided on the large circumferential surface (122), and when the cutting component (1) and the clamping component (2) are assembled in place, the end of the fastener (3) cooperates with the recessed bayonet (124) to realize the locking of the cutting component (1) and the clamping component (2).

10. The split drilling tool according to claim 9, characterized in that: The recessed bayonet (124) includes a bayonet upper side surface (1241), a bayonet bottom surface (1242) and a bayonet lower side surface (1243). When the cutting component (1) and the clamping component (2) are assembled in place, the clearances between the fastener (3) and the bayonet upper side surface (1241), the bayonet bottom surface (1242) and the bayonet lower side surface (1243) are t1, t2 and t3 respectively, and it should satisfy: 0 < t1 < 0.5 mm, t2 = t3 = 0.

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