A combined rotary cutting tool

Abstract

The present invention discloses a combined rotary cutting tool. The core cutting component includes a core cutting part and a core boss. The core boss is arranged on the positioning convex surface of the core cutting part. The core boss includes a core positioning surface, a core support surface, and two core side clamping surfaces located between the core positioning surface and the core support surface. Both of the two core side clamping surfaces are V-shaped. A core clamping hole penetrating through the core clamping surface and the core support surface is formed on the core boss. The peripheral cutting component includes a peripheral left cutting part, a peripheral recess, and a peripheral right cutting part arranged in sequence. The peripheral recess includes a peripheral recess support surface and two peripheral recess clamping surfaces respectively located on both sides of the peripheral recess support surface. Both of the two peripheral recess clamping surfaces are V-shaped and can be respectively matched with the two core side clamping surfaces. A peripheral clamping hole is formed on the peripheral recess support surface. During assembly, a fastener forms a threaded fit with the core clamping hole and the peripheral clamping hole to mount the core cutting component and the peripheral cutting component in a positioning groove. The present invention has the advantages of convenient loading and unloading, high positioning strength and accuracy, etc.

Description

Technical Field

[0001] The present invention mainly relates to the field of metal cutting, and particularly relates to a combined rotary cutting 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 technical problems, the commonly used drilling tools are generally 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 have low positioning accuracy, are easy to fall off, and have a short service life.

[0004] For example, Chinese Patent Document CN201511011474.7 discloses a drilling tool that uses interference clamping of threads. Although interference clamping of threads can be achieved, it is difficult to accurately control the interference size of the thread pitch diameter. At the same time, the interference position of the thread occurs on both sides of the thread profile, the contact area is small, the circumferential centering ability of the tool head is poor, and the axial positioning surface is in full contact. When installed in batches, it is difficult to ensure the axial and circumferential runout accuracy of the tool head. Secondly, the thread and torque surface of the tool head form an over-positioning structure during use, and the contact stability of the torque surface is poor during batch interchange. 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 combined rotary cutting tool that is convenient to load and unload, has high positioning strength and accuracy, and good versatility.

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

[0007] A combined rotary cutting tool includes a clamping component, a core cutting component, a peripheral cutting component, and a fastener. The clamping component includes a cutting part and a clamping part. A positioning groove is provided on the cutting part. A plurality of chip flutes penetrating the cutting part are provided on the peripheral surface of the clamping component. The clamping part is symmetric about the rotation center axis. The core cutting component includes a core cutting part and a core boss. The core boss is arranged on the positioning convex surface of the core cutting part. The core boss includes a core positioning surface, a core support surface, and two core side clamping surfaces located between the core positioning surface and the core support surface. Both of the two core side clamping surfaces are V-shaped. A core clamping hole penetrating the core positioning surface and the core support surface is provided on the core boss. The peripheral cutting component includes a peripheral left cutting part, a peripheral recess, and a peripheral right cutting part arranged in sequence. The peripheral recess includes a peripheral recess support surface and two peripheral recess clamping surfaces respectively located on both sides of the peripheral recess support surface. Both of the two peripheral recess clamping surfaces are V-shaped and can be respectively matched with the two core side clamping surfaces. A peripheral clamping hole is provided on the peripheral recess support surface. During assembly, the core side clamping surfaces and the peripheral recess clamping surfaces cooperate to form axial positioning and clamping of the core cutting component. The fastener forms a threaded fit with the core clamping hole and the peripheral clamping hole to mount the core cutting component and the peripheral cutting component in the positioning groove.

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

[0009] The positioning groove includes a groove top positioning surface, a groove bottom positioning surface, and two groove side clamping surfaces. Mounting holes are provided on the groove side clamping surfaces. After the core cutting component and the peripheral cutting component are mounted in place in the positioning groove, the two groove side clamping surfaces clamp the core cutting component and the peripheral cutting component. The groove bottom positioning surface performs axial positioning on the core cutting component and the peripheral cutting component. The fastener is mounted in the mounting hole.

[0010] The core cutting part includes two core front cutting surfaces, two core rear cutting surfaces, two core side surfaces, and one core back surface. Any one of the core front cutting surfaces intersects with the adjacent core rear cutting surface and core side surface to form a core end cutting edge and a core side cutting edge respectively.

[0011] Both the peripheral left cutting part and the peripheral right cutting part include a peripheral front cutting surface, a peripheral rear cutting surface, a peripheral side surface, and a peripheral side positioning surface. The peripheral front cutting surface intersects with the adjacent peripheral rear cutting surface and peripheral side surface to form a peripheral end cutting edge and a peripheral side cutting edge respectively.

[0012] The core side clamping surface includes a core upper clamping surface, a core lower clamping surface, and a core middle clamping surface located between the core upper clamping surface and the core lower clamping surface. The core upper clamping surface and the core lower clamping surface form a V-shaped positioning structure.

[0013] The circumferential recessed clamping surface includes an upper circumferential clamping surface, a lower circumferential clamping surface, and a middle circumferential clamping surface located between the upper circumferential clamping surface and the lower circumferential clamping surface. During assembly, the upper circumferential clamping surface and the lower circumferential clamping surface are respectively matched and positioned with the upper core clamping surface and the lower core clamping surface, the circumferential recessed support surface is matched and positioned with the core support surface, and the positioning convex surface is matched and positioned with the upper circumferential positioning surface of the circumferential recess.

[0014] The mounting hole includes a tapered hole and a threaded hole. The tapered hole is symmetric about the center of the tapered hole. The fastener includes a tapered head, a clamping column, and a threaded portion. The threaded portion sequentially passes through the tapered hole, the core clamping hole, and the circumferential clamping hole and is matched with the threaded hole, and the tapered head is matched with the tapered hole.

[0015] During the process of screwing the fastener into the threaded hole, the gaps between the two groove-side clamping surfaces and the core positioning surface and the circumferential-side positioning surface gradually decrease until they are in full contact, and the gap between the circumferential recessed support surface and the core support surface gradually decreases until they are in full contact.

[0016] The cutting diameter of the core cutting component is D1, the cutting diameter of the circumferential cutting component is D2, and the thickness of the core cutting component in the cutting direction is W, and the following should be satisfied: 0.3D2 ≤ D1 ≤ 0.6D2, 0.4D1 ≤ W ≤ 0.8D1.

[0017] The angle between the upper core clamping surfaces of the two core-side clamping surfaces is α1, and the angle between the upper circumferential clamping surfaces of the two circumferential recessed clamping surfaces is α1'. The following should be satisfied: 20° ≤ α1 ≤ 50°, 20° ≤ α1' ≤ 50°, 0° ≤ α1 - α1' ≤ 0.5°.

[0018] The angle between the lower core clamping surfaces of the two core-side clamping surfaces is α2, and the angle between the lower circumferential clamping surfaces of the two circumferential recessed clamping surfaces is α2'. The following should be satisfied: 20° ≤ α2 ≤ 50°, 20° ≤ α2' ≤ 50°, 0° ≤ α2 - α2' ≤ 0.5°.

[0019] The lower core clamping surfaces of the two core-side clamping surfaces are parallel to each other, and the lower circumferential clamping surfaces of the two circumferential recessed clamping surfaces are parallel to each other.

[0020] The angle between the lower circumferential positioning surfaces of the circumferential left cutting portion and the circumferential right cutting portion is β'. The groove bottom positioning surface includes a groove bottom left positioning surface and a groove bottom right positioning surface corresponding to the lower circumferential positioning surfaces of the circumferential left cutting portion and the circumferential right cutting portion respectively. The angle between the groove bottom left positioning surface and the groove bottom right positioning surface is β, and the following should be satisfied: 120° ≤ β ≤ 160°, 120° ≤ β' ≤ 160°, 0° ≤ β - β' ≤ 0.5°.

[0021] There is an included angle γ between the core positioning surface and the center line of the core clamping hole, and the included angle between the circumferential positioning surface and the center line of the circumferential clamping hole is γ'. It should satisfy: 65° ≤ γ ≤ 85°, 65° ≤ γ' ≤ 85°.

[0022] The gap between the positioning convex surface and the groove top positioning surface is τ1, and the gap between the lower core clamping surface and the corresponding lower circumferential clamping surface is τ2. It should satisfy: 0 ≤ τ1 ≤ 0.2 mm, 0 ≤ τ2 ≤ 0.05 mm.

[0023] During the process of inserting the fastener into the core cutting component, the center line of the fastener completely coincides with the center line of the core clamping hole. There is an offset d between the center line of the tapered hole and the core clamping hole in the direction pointing to the upper core cutting part. It should satisfy: 0.05 mm ≤ d ≤ 0.2 mm.

[0024] Compared with the prior art, the advantages of the present invention are as follows:

[0025] The combined rotary cutting tool of the present invention adopts a core cutting component and a circumferential cutting component with independent structures. The core cutting part can adopt a geometric structure with strong centering ability and the same cemented carbide substrate and coating structure with good toughness, or can be designed into a specific and independent cemented carbide substrate and coating structure according to different cutting conditions. The circumferential cutting component can adopt a geometric structure with good strength and a cemented carbide substrate and coating structure with high wear resistance. When used in combination, it takes into account the impact resistance of the core cutting part and the wear resistance of the circumferential cutting component, solves the technical problem that it is difficult to balance the hardness and toughness of the drilling tool, meets the processing requirements of various different working conditions, further reduces the use cost of the drilling tool. The core side clamping surface of the core boss is V-shaped and cooperates with the circumferential recessed clamping surface which is also V-shaped, realizing the mutual cooperation between the core cutting component and the circumferential cutting component. Then, the fastener forms a threaded fit with the core clamping hole and the circumferential clamping hole to install the core cutting component and the circumferential cutting component in the positioning groove, realizing the positioning and clamping of the core cutting component and the circumferential cutting component. It is not only convenient for loading and unloading, but also has high positioning strength and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is an exploded perspective view of the first embodiment of the combined rotary cutting tool of the present invention.

[0027] Figure 2 is the front view of the first embodiment of the combined rotary cutting tool of the present invention.

[0028] Figure 3 is the left view of the first embodiment of the combined rotary cutting tool of the present invention.

[0029] Figure 4 is Figure 2 the A-A view of

[0030] Figure 5 It is a schematic assembly diagram of the cutting component and the fastener of the first embodiment of the combined rotary cutting tool of the present invention.

[0031] Figure 6 It is a three-dimensional structure diagram of the core cutting component of the first embodiment of the combined rotary cutting tool of the present invention.

[0032] Figure 7 It is the front view of the core cutting component of the first embodiment of the combined rotary cutting tool of the present invention.

[0033] Figure 8 It is Figure 7 the B-B view of

[0034] Figure 9 It is a three-dimensional structure diagram of the peripheral cutting component of the first embodiment of the combined rotary cutting tool of the present invention.

[0035] Figure 10 It is the front view of the peripheral cutting component of the first embodiment of the combined rotary cutting tool of the present invention.

[0036] Figure 11 It is the top view of the peripheral cutting component of the first embodiment of the combined rotary cutting tool of the present invention.

[0037] Figure 12 It is a three-dimensional structure diagram of the fastener of the first embodiment of the combined rotary cutting tool of the present invention.

[0038] Figure 13 It is a three-dimensional structure diagram of the core cutting component of the second embodiment of the combined rotary cutting tool of the present invention.

[0039] Figure 14 It is the front view of the peripheral cutting component of the second embodiment of the combined rotary cutting tool of the present invention.

[0040] Figure 15 It is a schematic assembly diagram of the cutting component and the fastener of the second embodiment of the combined rotary cutting tool of the present invention.

[0041] Each reference numeral in the figure represents:

[0042] 1. Clamping component; 11. Cutting part; 12. Clamping part; 13. Positioning groove; 131. Top positioning surface of the groove; 132. Bottom positioning surface of the groove; 133. Side clamping surface of the groove; 135. Mounting hole; 1351. Taper hole; 1352. Threaded hole; 1353. Center of the taper hole; 14. Rotation center axis; 15. Chip groove; 2. Core cutting component; 21. Core cutting part; 211. Front core cutting surface; 212. Rear core cutting surface; 213. Side surface of the core; 214. Back surface of the core; 215. Core end cutting edge; 216. Core side cutting edge; 22. Core boss; 221. Core positioning surface; 222. Core support surface; 223. Side clamping surface of the core; 2231. Upper clamping surface of the core; 2232. Lower clamping surface of the core; 2233. Middle clamping surface of the core; 24. Core clamping hole; 25. Positioning convex surface; 3. Peripheral cutting component; 31. Left peripheral cutting part; 32. Right peripheral cutting part; 33. Peripheral recess; 331. Peripheral recess clamping surface; 3311. Upper clamping surface of the peripheral recess; 3312. Lower clamping surface of the peripheral recess; 3313. Middle clamping surface of the peripheral recess; 332. Peripheral recess support surface; 34. Peripheral clamping hole; 301. Front peripheral cutting surface; 302. Rear peripheral cutting surface; 303. Side surface of the periphery; 304. Upper positioning surface of the periphery; 35. Lower positioning surface of the periphery; 36. Side positioning surface of the periphery; 37. Peripheral end cutting edge; 38. Peripheral side cutting edge; 4. Fastener; 41. Tapered head; 42. Clamping column; 43. Threaded part. Detailed implementation manner

[0043] The present invention will be further described in detail below with reference to the accompanying drawings of the specification and specific embodiments.

[0044] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "horizontal", "inner", "outer", "top", "bottom", etc. indicating the orientation or position relationship are based on the orientation or position 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 cannot be understood as a limitation to the present invention.

[0045] Figures 1 to 12The first embodiment of the combined rotary cutting tool of the present invention is shown. The combined rotary cutting tool of this embodiment includes a clamping component 1, a core cutting component 2, a peripheral cutting component 3, and a fastener 4. The clamping component 1 includes a cutting portion 11 and a clamping portion 12. A positioning groove 13 is provided on the cutting portion 11. A plurality of chip flutes 15 penetrating the cutting portion 11 are provided on the circumferential surface of the clamping component 1. The clamping portion 12 is symmetric about the rotation center axis 14. The core cutting component 2 includes a core cutting portion 21 and a core boss 22. The core boss 22 is provided on the positioning convex surface 25 of the core cutting portion 21. The core boss 22 includes a core positioning surface 221, a core support surface 222, and two core side clamping surfaces 223 located between the core positioning surface 221 and the core support surface 222. Both of the two core side clamping surfaces 223 are V-shaped. A core clamping hole 24 penetrating the core positioning surface 221 and the core support surface 222 is provided on the core boss 22. The peripheral cutting component 3 includes a peripheral left cutting portion 31, a peripheral recess 33, and a peripheral right cutting portion 32 arranged in sequence. The peripheral recess 33 includes a peripheral recess support surface 332 and two peripheral recess clamping surfaces 331 respectively located on both sides of the peripheral recess support surface 332. Both of the two peripheral recess clamping surfaces 331 are V-shaped and can be respectively matched with the two core side clamping surfaces 223. A peripheral clamping hole 34 is provided on the peripheral recess support surface 332. During assembly, the core side clamping surface 223 and the peripheral recess clamping surface 331 cooperate to form axial positioning clamping of the core cutting component 2. The fastener 4 forms a threaded fit with the core clamping hole 24 and the peripheral clamping hole 34 to mount the core cutting component 2 and the peripheral cutting component 3 in the positioning groove 13. By using the structurally independent core cutting component 2 and peripheral cutting component 3, the core cutting portion 21 can adopt a geometric structure with strong centering ability and the same carbide substrate and coating structure with good toughness, or can be designed into a specific and independent carbide substrate and coating structure according to different cutting conditions. The peripheral cutting component 3 can adopt a geometric structure with good strength and a carbide substrate and coating structure with high wear resistance. When used in combination, the impact resistance of the core cutting component 2 and the wear resistance of the peripheral cutting component 3 are taken into account, solving the technical problem that it is difficult to balance the hardness and toughness of the drilling tool, meeting the processing requirements of various different working conditions, further reducing the use cost of the drilling tool. The core side clamping surface 223 of the core boss 22 is V-shaped and is matched with the peripheral recess clamping surface 331 of the equally V-shaped peripheral recess 33 to realize the mutual cooperation between the core cutting component 2 and the peripheral cutting component 3. Then, the fastener 4 forms a threaded fit with the core clamping hole 24 and the peripheral clamping hole 25 to mount the core cutting component 2 and the peripheral cutting component 3 in the positioning groove 14, realizing the positioning clamping of the core cutting component 2 and the peripheral cutting component 3, which is not only convenient for loading and unloading, but also has high positioning strength and accuracy.

[0046] In this embodiment, the positioning groove 13 includes a groove top positioning surface 131, a groove bottom positioning surface 132, and two groove side clamping surfaces 133. An installation hole 135 is formed in each groove side clamping surface 133. After the core cutting component 2 and the circumferential cutting component 3 are installed in place in the positioning groove 13, the two groove side clamping surfaces 133 clamp the core cutting component 2 and the circumferential cutting component 3, and the groove bottom positioning surface 132 axially positions the core cutting component 2 and the circumferential cutting component 3. The fastener 4 is installed in the installation hole 135.

[0047] In this embodiment, the core cutting portion 21 includes two core front cutting surfaces 211, two core rear cutting surfaces 212, two core side surfaces 213, and one core back surface 214. Any core front cutting surface 211 intersects with the adjacent core rear cutting surface 212 and core side surface 213 to form a core end cutting edge 215 and a core side cutting edge 216 respectively.

[0048] In this embodiment, both the circumferential left cutting portion 31 and the circumferential right cutting portion 32 include a circumferential front cutting surface 301, a circumferential rear cutting surface 302, a circumferential side surface 303, and a circumferential side positioning surface 36. The circumferential front cutting surface 301 intersects with the adjacent circumferential rear cutting surface 302 and circumferential side surface 303 to form a circumferential end cutting edge 37 and a circumferential side cutting edge 38 respectively.

[0049] In this embodiment, the core side clamping surface 223 includes an upper core clamping surface 2231, a lower core clamping surface 2232, and a middle core clamping surface 2233 located between the upper core clamping surface 2231 and the lower core clamping surface 2232. The upper core clamping surface 2231 and the lower core clamping surface 2232 form a V-shaped positioning structure. The circumferential recessed clamping surface 331 includes an upper circumferential clamping surface 3311, a lower circumferential clamping surface 3312, and a middle circumferential clamping surface 3313 located between the upper circumferential clamping surface 3311 and the lower circumferential clamping surface 3312. During assembly, the upper circumferential clamping surface 3311 and the lower circumferential clamping surface 3312 are respectively matched and positioned with the upper core clamping surface 2231 and the lower core clamping surface 2232, the circumferential recessed support surface 332 is matched and positioned with the core support surface 222, and the positioning convex surface 25 is matched and positioned with the upper positioning surface 304 of the circumferential recess 33, effectively improving the installation dimension accuracy and positioning stability of the core cutting component 2 and the circumferential cutting component 3, and enabling the core cutting component 2 and the circumferential cutting component 3 to have high cutting efficiency and long service life.

[0050] In this embodiment, the mounting hole 135 includes a tapered hole 1351 and a threaded hole 1352. The tapered hole 1351 is symmetric about the tapered hole center 1353. The fastener 4 includes a tapered head 41, a clamping column 42, and a threaded portion 43. The threaded portion 43 sequentially passes through the tapered hole 1351, the core clamping hole 24, and the peripheral clamping hole 34 and cooperates with the threaded hole 1352. The tapered head 41 cooperates with the tapered hole 1351. During the process of screwing the fastener 4 into the threaded hole 1352, the gaps between the two groove side clamping surfaces 133 and the core positioning surface 221 and the peripheral side positioning surface 36 gradually decrease until they are in full contact, and the gap between the peripheral recessed support surface 332 and the core support surface 222 gradually decreases until they are in full contact. During the process of tightening the fastener 4, the positioning groove 13 realizes the elastic positioning and clamping of the core cutting member 2 and the peripheral cutting member 3, improving the positioning strength and stability.

[0051] In this embodiment, the cutting diameter of the core cutting member 2 is D1, and the cutting diameter of the peripheral cutting member 3 is D2. The thickness of the core cutting member 2 in the cutting direction is W. To ensure the strength and cutting stability of the core cutting member 2 and the peripheral cutting member 3, it should satisfy: 0.3D2 ≤ D1 ≤ 0.6D2, 0.4D1 ≤ W ≤ 0.8D1. In this embodiment, D1 = 45D2 and W = 0.6D1.

[0052] In this embodiment, the angle between the core upper clamping surfaces 2231 of the two core side clamping surfaces 223 is α1, and the angle between the peripheral upper clamping surfaces 3311 of the two peripheral recessed clamping surfaces 331 is α1'. To ensure the positioning stability of the core cutting member 2 and the peripheral cutting member 3 and improve the drilling processing dimension accuracy and surface quality, it should satisfy: 20° ≤ α1 ≤ 50°, 20° ≤ α1' ≤ 50°, 0° ≤ α1 - α1' ≤ 0.5°. In this embodiment, α1 = α2 = 35°.

[0053] In this embodiment, the angle between the core lower clamping surfaces 2232 of the two core side clamping surfaces 223 is α2, and the angle between the peripheral lower clamping surfaces 3312 of the two peripheral recessed clamping surfaces 331 is α2'. It should satisfy: 20° ≤ α2 ≤ 50°, 20° ≤ α2' ≤ 50°, 0° ≤ α2 - α2' ≤ 0.5°. In this embodiment, α1' = α2' = 34.7°.

[0054] In this embodiment, the included angle between the lower peripheral positioning surfaces 35 of the left peripheral cutting part 31 and the right peripheral cutting part 32 is β'. The bottom positioning surface 132 includes a left bottom positioning surface and a right bottom positioning surface corresponding to the lower peripheral positioning surfaces 35 of the left peripheral cutting part 31 and the right peripheral cutting part 32 respectively. The included angle between the left bottom positioning surface and the right bottom positioning surface is β. To ensure the positioning stability and strength of the core peripheral cutting component 3 and improve the dimensional accuracy and surface quality of drilling, it should satisfy: 120° ≤ β ≤ 160°, 120° ≤ β' ≤ 160°, 0° ≤ β - β' ≤ 0.5°. In this embodiment, β = 142° and β' = 141.85°.

[0055] In this embodiment, there is an included angle γ between the core positioning surface 221 and the center line of the core clamping hole 24, and the included angle between the peripheral positioning surface 36 and the center line of the peripheral clamping hole 34 is γ'. To ensure the clamping and positioning stability of the clamping component 1 for the core cutting component 2 and the peripheral cutting component 3 and ensure the strength of the core cutting component 2, it should satisfy: 65° ≤ γ ≤ 85°, 65° ≤ γ' ≤ 85°. In this embodiment, γ = γ' = 73°.

[0056] In this embodiment, the gap between the positioning convex surface 25 and the top positioning surface 131 is τ1, and the gap between the lower core clamping surface 2232 and the corresponding lower peripheral clamping surface 3312 is τ2. To ensure the positioning stability and impact resistance of the core cutting component 2, reduce the load of the fastener 4 and avoid axial loosening of the core cutting component 2, it should satisfy: 0 ≤ τ1 ≤ 0.2 mm, 0 ≤ τ2 ≤ 0.05 mm. In this embodiment, τ1 = 0.02 mm and τ2 = 0.03 mm.

[0057] In this embodiment, during the process of installing the fastener 4 into the core cutting component 2, the center line of the fastener 4 coincides completely with the center line of the core clamping hole 24. There is an offset d between the center line of the tapered hole 1351 and the core clamping hole 24 in the direction pointing to the upper core cutting part 21. To ensure that when the assembly is in place, all positioning surfaces can be in full contact and improve the positioning stability of the core cutting component 2 and the peripheral cutting component 3, it should satisfy: 0.05 mm ≤ d ≤ 0.2 mm. In this embodiment, d = 0.12 mm.

[0058] Figures 13 to 15 The second embodiment of the combined rotary cutting tool of the present invention is shown. The combined rotary cutting tool of this embodiment is basically the same as the first embodiment, with the only difference being that: in this embodiment, the lower core clamping surfaces 2232 of the two core side clamping surfaces 223 are parallel to each other, and the lower peripheral clamping surfaces 3312 of the two peripheral concave clamping surfaces 331 are parallel to each other. Thus, without affecting the positioning strength, accuracy, and cutting performance, the manufacturing difficulty and processing cost of the core cutting component 2 and the peripheral cutting component 3 are reduced.

[0059] In the above embodiments, the application of the present invention is on drilling tools. The present invention is not limited to this. According to different cutting application conditions, the present invention application can also be applied to other machining tools such as milling cutters.

[0060] Although the present invention has been disclosed above with 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 by using the technical content disclosed above, or modify it into an equivalent embodiment with equivalent changes. 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 technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A combined rotary cutting tool, comprising a clamping member (1), a core cutting member (2), a peripheral cutting member (3) and a fastener (4), wherein the clamping member (1) includes a cutting portion (11) and a clamping portion (12), a positioning groove (13) is provided on the cutting portion (11), a plurality of chip flutes (15) penetrating through the cutting portion (11) are provided on the circumferential surface of the clamping member (1), the clamping portion (12) is symmetric about the rotation central axis (14), and it is characterized in that: The core cutting component (2) includes a core cutting part (21) and a core boss (22). The core boss (22) is arranged on the positioning convex surface (25) of the core cutting part (21). The core boss (22) includes a core positioning surface (221), a core supporting surface (222), and two core side clamping surfaces (223) located between the core positioning surface (221) and the core supporting surface (222). Both of the two core side clamping surfaces (223) are V-shaped. A core clamping hole (24) penetrating through the core positioning surface (221) and the core supporting surface (222) is formed on the core boss (22). The peripheral cutting component (3) includes a peripheral left cutting part (31), a peripheral recess (33), and a peripheral right cutting part (32) arranged in sequence. The peripheral recess (33) includes a peripheral recess supporting surface (332) and two peripheral recess clamping surfaces (331) respectively located on both sides of the peripheral recess supporting surface (332). Both of the two peripheral recess clamping surfaces (331) are V-shaped and can cooperate with the two core side clamping surfaces (223) respectively. A peripheral clamping hole (34) is formed on the peripheral recess supporting surface (332). During assembly, the core side clamping surfaces (223) and the peripheral recess clamping surfaces (331) cooperate to form axial positioning and clamping of the core cutting component (2). The fastener (4) forms a threaded fit with the core clamping hole (24) and the peripheral clamping hole (34) to install the core cutting component (2) and the peripheral cutting component (3) in the positioning groove (13).

2. The combined rotary cutting tool according to claim 1, wherein: The positioning groove (13) includes a groove top positioning surface (131), a groove bottom positioning surface (132), and two groove side clamping surfaces (133). An installation hole (135) is formed on the groove side clamping surface (133). After the core cutting component (2) and the peripheral cutting component (3) are installed in place in the positioning groove (13), the two groove side clamping surfaces (133) clamp the core cutting component (2) and the peripheral cutting component (3), and the groove bottom positioning surface (132) performs axial positioning on the core cutting component (2) and the peripheral cutting component (3). The fastener (4) is installed in the installation hole (135).

3. The combined rotary cutting tool according to claim 2, characterized in that: The core cutting part (21) includes two core front tool faces (211), two core rear tool faces (212), two core side faces (213), and one core back face (214). Any one of the core front tool faces (211) intersects with the adjacent core rear tool face (212) and core side face (213) to form a core end cutting edge (215) and a core side cutting edge (216) respectively.

4. The combined rotary cutting tool according to claim 3, characterized in that: The peripheral left cutting part (31) and the peripheral right cutting part (32) both include a peripheral front tool face (301), a peripheral rear tool face (302), a peripheral side face (303), and a peripheral side positioning surface (36). The peripheral front tool face (301) intersects with the adjacent peripheral rear tool face (302) and peripheral side face (303) to form a peripheral end cutting edge (37) and a peripheral side cutting edge (38) respectively.

5. The combined rotary cutting tool according to claim 4, wherein: The core-side clamping surface (223) includes an upper core clamping surface (2231), a lower core clamping surface (2232), and a middle core clamping surface (2233) located between the upper core clamping surface (2231) and the lower core clamping surface (2232). The upper core clamping surface (2231) and the lower core clamping surface (2232) form a V-shaped positioning structure.

6. The combined rotary cutting tool according to claim 5, wherein: The circumferential recessed clamping surface (331) includes an upper circumferential clamping surface (3311), a lower circumferential clamping surface (3312), and a middle circumferential clamping surface (3313) located between the upper circumferential clamping surface (3311) and the lower circumferential clamping surface (3312). During assembly, the upper circumferential clamping surface (3311) and the lower circumferential clamping surface (3312) are respectively engaged with the upper core clamping surface (2231) and the lower core clamping surface (2232) for positioning. The circumferential recessed support surface (332) is engaged with the core support surface (222) for positioning. The positioning protrusion surface (25) is engaged with the upper circumferential positioning surface (304) of the circumferential recess (33) for positioning.

7. The combined rotary cutting tool according to claim 5 or 6, characterized in that: The mounting hole (135) includes a tapered hole (1351) and a threaded hole (1352). The tapered hole (1351) is symmetric about the tapered hole center (1353). The fastener (4) includes a tapered head (41), a clamping column (42), and a threaded portion (43). The threaded portion (43) sequentially passes through the tapered hole (1351), the core clamping hole (24), and the circumferential clamping hole (34) and is engaged with the threaded hole (1352). The tapered head (41) is engaged with the tapered hole (1351).

8. The combined rotary cutting tool according to claim 7, characterized in that: During the process of screwing the fastener (4) into the threaded hole (1352), the gaps between the two groove-side clamping surfaces (133) and the core positioning surface (221) and the circumferential side positioning surface (36) gradually decrease until complete contact, and the gap between the circumferential recessed support surface (332) and the core support surface (222) gradually decreases until complete contact.

9. The combined rotary cutting tool according to claim 5 or 6, characterized in that: The cutting diameter of the core cutting member (2) is D1, and the cutting diameter of the circumferential cutting member (3) is D2. The thickness of the core cutting member (2) in the cutting direction is W, and the following should be satisfied: 0.3D2 ≤ D1 ≤ 0.6D2, 0.4D1 ≤ W ≤ 0.8D1.

10. The combined rotary cutting tool according to claim 5 or 6, characterized in that: The angle between the upper core clamping surfaces (2231) of the two core-side clamping surfaces (223) is α1, and the angle between the upper circumferential clamping surfaces (3311) of the two circumferential recessed clamping surfaces (331) is α1'. The following should be satisfied: 20° ≤ α1 ≤ 50°, 20° ≤ α1' ≤ 50°, 0° ≤ α1 - α1' ≤ 0.5°.

11. The combined rotary cutting tool according to claim 10, characterized in that: The angle between the lower core clamping surfaces (2232) of the two core-side clamping surfaces (223) is α2, and the angle between the lower circumferential clamping surfaces (3312) of the two circumferential recessed clamping surfaces (331) is α2'. The following should be satisfied: 20° ≤ α2 ≤ 50°, 20° ≤ α2' ≤ 50°, 0° ≤ α2 - α2' ≤ 0.5°.

12. The combined rotary cutting tool according to claim 10, characterized in that: The lower core clamping surfaces (2232) of the two core-side clamping surfaces (223) are parallel to each other, and the lower circumferential clamping surfaces (3312) of the two circumferential recessed clamping surfaces (331) are parallel to each other.

13. The combined rotary cutting tool according to claim 5 or 6, characterized in that: The included angle between the circumferential lower positioning surfaces (35) of the circumferential left cutting part (31) and the circumferential right cutting part (32) is β'. The groove bottom positioning surface (132) includes a groove bottom left positioning surface and a groove bottom right positioning surface respectively corresponding to the circumferential lower positioning surfaces (35) of the circumferential left cutting part (31) and the circumferential right cutting part (32). The included angle between the groove bottom left positioning surface and the groove bottom right positioning surface is β, and it should satisfy: 120° ≤ β ≤ 160°, 120° ≤ β' ≤ 160°, 0° ≤ β - β' ≤ 0.5°.

14. The combined rotary cutting tool according to claim 7, characterized in that: There is an included angle γ between the core positioning surface (221) and the center line of the core clamping hole (24), and the included angle between the circumferential side positioning surface (36) and the center line of the circumferential clamping hole (34) is γ'. It should satisfy: 65° ≤ γ ≤ 85°, 65° ≤ γ' ≤ 85°.

15. The combined rotary cutting tool according to claim 14, characterized in that: The gap between the positioning convex surface (25) and the groove top positioning surface (131) is τ1, and the gap between the core lower clamping surface (2232) and the corresponding circumferential lower clamping surface (3312) is τ2. It should satisfy: 0 ≤ τ1 ≤ 0.2 mm, 0 ≤ τ2 ≤ 0.05 mm.

16. The combined rotary cutting tool according to claim 14, wherein: During the process of loading the fastener (4) into the core cutting component (2), the center line of the fastener (4) completely coincides with the center line of the core clamping hole (24). There is an offset d between the center line of the tapered hole (1351) and the core clamping hole (24) in the direction pointing to the core cutting part (21). It should satisfy: 0.05 mm ≤ d ≤ 0.2 mm.

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