Split type drilling tool

Abstract

This invention discloses a split-type drilling tool, comprising a tool body circumferential surface, a shank, a cutting tool section, and a tool body circumferential surface. The cutting tool section, at its end away from the shank, has a tool body end face, a peripheral groove, and a central groove. The peripheral groove includes a peripheral insert positioning groove and a peripheral chip-receiving groove, and the central groove includes a central insert positioning groove and a central chip-receiving groove. The tool body circumferential surface has a peripheral chip-removing groove and a central chip-removing groove, connected to the central chip-receiving groove. The peripheral chip-receiving groove includes a peripheral chip-removing groove sidewall and a peripheral chip-removing groove bottom surface. The peripheral chip-removing groove sidewall has a groove, which is arc-shaped with a radius of R1. The maximum cutting width of the peripheral insert is L, satisfying: 0.6L ≥ R1 ≥ 0.3L. The maximum distance between the groove and the peripheral insert on the side adjacent to the tool body circumferential surface is L1, satisfying: 1.8L ≥ L1 ≥ 1.2L. This split-type drilling tool improves chip removal performance and versatility, meeting the processing requirements of different processing parameters and materials, and extending its service life.

Description

Technical Field

[0001] This invention relates to the field of metal cutting technology, and specifically to a split-type drilling tool. Background Technology

[0002] When drilling tools cut, the cutting force is mainly borne by the cutting tip. The spiral groove and the machined surface form a closed area, and the chips can only be discharged from the cutting tip through the spiral groove. Chip discharge is difficult. When the chips cannot be discharged from the workpiece in time, the accumulated chips and the spiral groove and machined surface will cause severe scraping and compression. The tool body will vibrate due to the imbalance of circumferential forces. This not only reduces the quality of the machined surface, but also significantly reduces the life of the drilling tool. Therefore, the chip removal performance of drilling tools is an important factor affecting tool performance, which places high demands on the chip curling performance of the tools.

[0003] In the prior art, to reduce the cost of tool use, drilling tools are usually designed as replaceable split structures, which can save costs by replacing the inserts. That is, the drilling tool consists of two parts: the insert and the tool body. The insert includes a central insert and peripheral inserts. The central insert is used for central material removal, and the peripheral insert is used for peripheral material removal. For example, Chinese patent document with application number 202210560807.5 discloses a drilling tool, in which the central groove is set near the rotation center axis, and the circumferential groove is set near the circumferential surface of the tool body. The circumferential surface of the tool body has a central chip removal groove and a circumferential chip removal groove, both of which are helical structures. The circumferential chip removal groove is directly connected to the circumferential chip removal groove. The central chip removal groove and the central chip removal groove are connected by a central transition groove, which extends from the rotation center axis in the direction of the circumferential surface of the tool body. Existing drilling tools typically feature circumferential chip flutes designed in a planar or near-planar shape to ensure ease of machining and strength. However, drilling tools using these circumferential chip flutes suffer from several drawbacks. First, due to the relatively high linear velocity of the peripheral inserts, when cutting with low parameters to achieve high surface quality, the chip thickness is small, making it difficult to curl and break properly, resulting in numerous long chips, easy scraping of the sidewalls, and poor machining performance. Second, fine chips tend to accumulate at the junction of the circumferential chip evacuation groove and the circumferential chip flute, hindering high-parameter machining of short-chip materials. Third, when machining soft materials and difficult-to-machine materials such as stainless steel, the large plastic deformation of the material makes it difficult for the chips from the peripheral inserts to curl properly, posing a risk to chip removal and leading to problems such as tool sidewall scraping, out-of-tolerance hole dimensions, and even tool failure. Fourth, the continuous impact of chips on the sidewalls of the circumferential chip flute causes rapid wear, resulting in a short tool life. In summary, existing drilling tools have poor chip removal performance, poor versatility, cannot meet the processing requirements of different processing parameters and materials, and have a short service life. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a split-type drilling tool that not only improves chip removal performance and versatility, but also has good strength, can meet the processing requirements of different processing parameters and different materials, and extends service life.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A split-type drilling tool includes a cutting insert and a cutting tool body. The cutting insert includes a peripheral insert and a center insert. The cutting tool body includes a shank and a cutting tool portion. The outer periphery of the cutting tool portion is provided with a tool body circumferential surface. The shank, cutting tool portion, and tool body circumferential surfaces are all symmetrical about the rotation axis of the cutting tool body. The end of the cutting tool portion away from the shank is provided with a tool body end face, a peripheral groove for adapting to the peripheral insert, and a center groove for adapting to the center insert. The peripheral groove includes a peripheral insert positioning groove and a peripheral chip groove. The center groove includes a center insert positioning groove and a center chip groove. The tool body circumferential surface is provided with peripheral chip removal grooves that extend helically around the rotation axis. The peripheral chip-removing groove includes a central chip-removing groove connected to a central chip-collecting groove. The peripheral chip-collecting groove comprises a peripheral chip-collecting groove sidewall connected to the circumferential surface of the tool body and a peripheral chip-collecting groove bottom surface connected to a peripheral blade positioning groove. The peripheral chip-collecting groove sidewall has a groove extending from the peripheral chip-removing groove to the end face of the tool body. This groove is arc-shaped on a normal plane B, which is a plane perpendicular to the extension direction of the groove. The radius of the arc of the groove is R1. The maximum cutting width of the peripheral blade is L, satisfying: 0.6L ≥ R1 ≥ 0.3L. The maximum distance between the groove and the peripheral blade on the side adjacent to the circumferential surface of the tool body is L1, satisfying: 1.8L ≥ L1 ≥ 1.2L.

[0007] As a further improvement to the above technical solution:

[0008] The width of the groove gradually decreases from the peripheral chip removal groove to the end face of the cutter body.

[0009] The minimum distance between the groove and the circumference of the blade body is L3, which satisfies: 6mm≥L3≥0mm.

[0010] L3 = 1.8 mm.

[0011] L=8.4mm, R1=5.0mm, L1=13.5mm.

[0012] The groove is symmetrically arranged about the symmetry plane C, and the symmetry plane C is perpendicular to the normal plane B.

[0013] The symmetrical plane C intersects with the plane perpendicular to the bottom surface of the peripheral chip groove to form an intersection line J1. The angle between the intersection line J1 and the rotation center axis is a, which satisfies: 20°≥a≥0°.

[0014] The intersection of the groove and the symmetry plane C forms an intersection line J2, which is a curve.

[0015] The radius of curvature of the intersection line J2 is R2, which satisfies: 2.5L≥R2≥1.5L.

[0016] The intersection line J2 includes a first line segment J21 and a second line segment J22. The first line segment J21 is connected to the end face of the tool body, and the second line segment J22 is connected to the peripheral chip removal groove. The first line segment J21 is an arc with a radius of R3; the second line segment J22 is an arc with a radius of R4 and is tangent to the first line segment J21, satisfying: 2.5L≥R3≥1.5L, R4>R3; or, the second line segment J22 is straight and is tangent to the first line segment J21.

[0017] Compared with the prior art, the advantages of the present invention are as follows:

[0018] The split-type drilling tool of this invention features a specially designed groove. When chips generated by the peripheral inserts flow towards the sidewall of the peripheral chip groove, the groove changes the direction of the chip flow, assisting in the inward curling and breaking of the chips. This effectively reduces the generation of long chips and sidewall scraping, improving machining performance when cutting with low parameters and machining soft materials. The groove on the sidewall of the peripheral chip groove is designed so that one end communicates with the peripheral chip removal groove, and the other end extends to the end face of the tool body, effectively preventing the accumulation of fine chips at the junction of the peripheral chip removal groove and the peripheral chip groove, enabling high-parameter machining of short-chip materials. The groove effectively improves the chip curling and removal performance of the peripheral inserts, thus meeting the machining requirements of different parameters and materials, and improving the tool's versatility. Simultaneously, the groove changes the direction of chip flow, helping to avoid continuous impact from chips on the sidewall of the peripheral chip groove, reducing impact wear and extending tool life. In summary, the groove design with a special structure not only improves the overall chip removal performance and versatility of drilling tools, but also provides excellent strength, meets the processing requirements of different processing parameters and materials, and extends service life. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural schematic diagram of an embodiment of the split-type drilling tool of the present invention.

[0020] Figure 2 This is a three-dimensional structural diagram of the peripheral groove in Embodiment 1 of the split-type drilling tool of the present invention.

[0021] Figure 3 This is a three-dimensional structural diagram of the central groove in Embodiment 1 of the split-type drilling tool of the present invention.

[0022] Figure 4This is a left-side view of the structure of an embodiment of the split-type drilling tool of the present invention.

[0023] Figure 5 This is a three-dimensional structural diagram of the normal plane B of the groove in Embodiment 1 of the split-type drilling tool of the present invention.

[0024] Figure 6 This is a schematic diagram of the cross-sectional structure of the split-type drilling tool of the present invention at the plane of symmetry C.

[0025] Figure 7 This is a three-dimensional structural diagram of the symmetrical plane C of the groove in Embodiment 1 of the split-type drilling tool of the present invention.

[0026] Figure 8 This is a front view structural diagram of the cutting tool section in Embodiment 1 of the split-type drilling tool of the present invention.

[0027] Figure 9 This is a schematic diagram of the longitudinal section structure of the split-type drilling tool of the present invention at the plane of symmetry C.

[0028] Figure 10 This is a three-dimensional structural schematic diagram of a second embodiment of the split-type drilling tool of the present invention.

[0029] Figure 11 This is a schematic diagram of the longitudinal section structure at the plane of symmetry C of Embodiment 2 of the split drilling tool of the present invention.

[0030] Figure 12 This is a schematic diagram of the longitudinal section structure at the plane of symmetry C in Embodiment 3 of the present invention.

[0031] The labels in the diagram represent:

[0032] 1. Cutting insert; 11. Peripheral insert; 12. Center insert; 2. Cutting tool body; 21. Shank; 22. Cutting tool section; 23. Peripheral surface of the tool body; 24. End face of the tool body; 25. Peripheral groove; 26. Center groove; 27. Rotation center axis; 31. Peripheral insert positioning groove; 32. Peripheral chip groove; 33. Peripheral chip removal groove; 41. Center insert positioning groove; 42. Center chip groove; 43. Center chip removal groove; 51. Side wall of peripheral chip groove; 52. Bottom surface of peripheral chip groove; 61. Groove. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0036] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] Example 1:

[0038] Figures 1 to 9This invention illustrates a first embodiment of a split-type drilling tool. The split-type drilling tool of this embodiment includes a cutting insert 1 and a cutting tool body 2. The cutting insert 1 includes a peripheral insert 11 and a center insert 12. The cutting tool body 2 includes a shank 21 and a cutting tool portion 22. The outer periphery of the cutting tool portion 22 is provided with a tool body peripheral surface 23. The shank 21, the cutting tool portion 22, and the tool body peripheral surface 23 are all symmetrical about the rotation center axis 27 of the cutting tool body 2. The end of the cutting tool portion 22 away from the shank 21 is provided with a tool body end face 24, a peripheral groove 25 adapted to the peripheral insert 11, and a center groove 26 adapted to the center insert 12. The peripheral groove 25 includes a peripheral insert positioning groove 31 and a peripheral chip-receiving groove 32. The center groove 26 includes a center insert positioning groove 41 and a center chip-receiving groove 42. The tool body peripheral surface 23... The device is provided with a peripheral chip removal groove 33 and a central chip removal groove 43 that extend spirally around the central axis 27. The central chip removal groove 43 is connected to the central chip receiving groove 42. The peripheral chip receiving groove 32 includes a peripheral chip receiving groove sidewall 51 connected to the peripheral surface 23 of the tool body and a peripheral chip receiving groove bottom surface 52 connected to the peripheral blade positioning groove 31. The peripheral chip receiving groove sidewall 51 is provided with a groove 61 extending from the peripheral chip removal groove 33 to the end face 24 of the tool body. The groove 61 is arc-shaped on the normal plane B, which is a plane perpendicular to the extension direction of the groove 61. The radius of the arc of the groove 61 is R1. The maximum cutting width of the peripheral blade 11 is L, which satisfies: 0.6L≥R1≥0.3L. The maximum distance between the groove 61 and the peripheral blade 11 on the side near the peripheral surface 23 of the tool body is L1, which satisfies: 1.8L≥L1≥1.2L.

[0039] The groove 61 extends from the peripheral chip removal groove 33 to the end face 24 of the tool body. That is, the groove 61 connects the peripheral chip removal groove 33 and the end face 24 of the tool body. Specifically, one end of the groove 61 communicates with the peripheral chip removal groove 33, and the other end extends through to the end face 24 of the tool body. This prevents the accumulation of fine iron chips at the junction of the peripheral chip removal groove 33 and the peripheral chip receiving groove 32 when machining short cutting materials, enabling high-parameter machining of short-chip materials. The groove 61 is arc-shaped on the normal plane B, which helps to change the flow direction of long iron chips when cutting with small machining parameters and machining soft materials. This assists in the inward curling and breaking of the iron chips. Simultaneously, the groove changes the flow direction of the iron chips, which helps to avoid continuous impact of iron chips on the side wall 51 of the peripheral chip receiving groove, improving service life and machining performance. 0.6L≥R1≥0.3L, 1.8L≥L1≥1.2L, which improves the chip rolling and chip removal performance of the peripheral blade 11, further reduces the scraping of the side wall 51 of the peripheral chip groove, further improves the processing performance and extends the service life, and can meet the processing and processing strength requirements of different processing parameters and materials, thus improving versatility.

[0040] This split-type drilling tool, due to the specially designed groove 61, can change the direction of chip flow when the chips generated by the peripheral inserts 11 flow towards the sidewall 51 of the peripheral chip groove, assisting the chips to curl inward and break. This effectively reduces the generation of long chips and sidewall scraping, improving machining performance when cutting with low parameters and machining soft materials. The groove 61 on the sidewall 51 of the peripheral chip groove is designed so that one end communicates with the peripheral chip removal groove 33, and the other end extends to the end face 24 of the tool body, effectively preventing the accumulation of fine chips at the junction of the peripheral chip removal groove 33 and the peripheral chip groove 32, enabling high-parameter machining of short-chip materials. The groove 61 effectively improves the chip curling and removal performance of the peripheral inserts 11, thus meeting the machining needs of different parameters and materials, and improving the tool's versatility. At the same time, the groove 61 changes the direction of chip flow, helping to avoid continuous impact of chips on the sidewall 51 of the peripheral chip groove, reducing impact wear and extending tool life. In summary, the groove 61 with its special structure not only improves the overall chip removal performance and versatility of drilling tools, but also provides excellent strength, meets the processing requirements of different processing parameters and materials, and extends their service life.

[0041] Furthermore, such as Figure 2 As shown, in this embodiment, the width of the groove 61 gradually decreases from the peripheral chip removal groove 33 to the end face 24 of the cutter body, further reducing the curling radius of the iron chips and making the iron chips curl more tightly, thereby further improving the chip removal performance.

[0042] Furthermore, such as Figure 4 As shown, in this embodiment, the minimum distance between the groove 61 and the peripheral surface 23 of the cutter body is L3, which satisfies: 6mm ≥ L3 ≥ 0mm, further reducing the scraping of the surrounding chip groove sidewall 51 by the iron filings curled by the groove 61. Preferably, L3 = 1.8mm.

[0043] Preferably, L=8.4mm, R1=5.0mm, and L1=13.5mm.

[0044] Furthermore, in this embodiment, the grooves 61 are symmetrically arranged about the plane of symmetry C, which is perpendicular to the normal plane B. The symmetrical arrangement of the grooves 61 about the plane of symmetry C facilitates processing and helps improve chip removal performance.

[0045] Furthermore, such as Figure 8 As shown, in this embodiment, the plane of symmetry C intersects with the plane perpendicular to the bottom surface 52 of the peripheral chip groove to form an intersection line J1. The angle between the intersection line J1 and the rotation center axis 27 is α, which satisfies: 20° ≥ α ≥ 0°. This allows for better control of the curling direction of the iron chips from the peripheral blade 11, thereby helping to improve the chip removal performance. Preferably, α = 13°.

[0046] Furthermore, such as Figure 7 As shown, in this embodiment, the intersection of the groove 61 and the symmetrical plane C forms an intersection line J2. The intersection line J2 is a curve, which can strengthen the tendency of the iron filings to curl inward, and at the same time help to ensure the unobstructed flow of the groove 61.

[0047] Furthermore, in this embodiment, the radius of curvature of the intersection line J2 is R2, which satisfies: 2.5L ≥ R2 ≥ 1.5L, resulting in a very good tendency for the iron filings to curl inward, and the unobstructed flow of the groove 61 is also very good. Preferably, R2 = 16mm.

[0048] Example 2:

[0049] Figure 10 and Figure 11 This paper illustrates a second embodiment of the split-type drilling tool of the present invention. The split-type drilling tool of this embodiment is basically the same as that of Embodiment 1, except that the intersection line J2 includes a first segment J21 and a second segment J22. The first segment J21 is connected to the end face 24 of the tool body, and the second segment J22 is connected to the peripheral chip removal groove 33. The first segment J21 is an arc with a radius of R3; the second segment J22 is an arc with a radius of R4 and is tangent to the first segment J21, satisfying: 2.5L ≥ R3 ≥ 1.5L, R4 > R3. Preferably, R3 = 16mm, R4 = 40mm.

[0050] Example 3:

[0051] Figure 12 This paper presents a third embodiment of the split-type drilling tool of the present invention. The split-type drilling tool in this embodiment is basically the same as that in the first embodiment, except that the second line segment J22 is straight and tangent to the first line segment J21. Preferably, R3 = 16mm.

[0052] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A split-type drilling tool, comprising a cutting insert (1) and a cutting tool body (2), wherein the cutting insert (1) comprises a peripheral insert (11) and a center insert (12), and the cutting tool body (2) comprises a shank (21) and a cutting tool portion (22), wherein the outer periphery of the cutting tool portion (22) is provided with a tool body peripheral surface (23), wherein the shank (21), the cutting tool portion (22) and the tool body peripheral surface (23) are all symmetrical about the rotation center axis (27) of the cutting tool body (2), and the end of the cutting tool portion (22) away from the shank (21) is provided with a tool body end face (24), a peripheral groove (25) adapted to the peripheral insert (11) and an adapted center insert. (12) The central groove (26), the peripheral groove (25) includes a peripheral blade positioning groove (31) and a peripheral chip collection groove (32), the central groove (26) includes a central blade positioning groove (41) and a central chip collection groove (42), the peripheral surface (23) of the cutter body is provided with a peripheral chip removal groove (33) and a central chip removal groove (43) that extend spirally around the rotation central axis (27), the central chip removal groove (43) is connected to the central chip collection groove (42), the peripheral chip collection groove (32) includes a peripheral chip collection groove sidewall (51) connected to the peripheral surface (23) of the cutter body and a peripheral chip collection groove bottom surface (52) connected to the peripheral blade positioning groove (31), characterized in that: The peripheral chip groove sidewall (51) is provided with a groove (61) extending from the peripheral chip removal groove (33) to the end face (24) of the cutter body. The groove (61) is arc-shaped on the normal plane B, which is a plane perpendicular to the extension direction of the groove (61). The radius of the arc of the groove (61) is R1. The maximum cutting width of the peripheral blade (11) is L, which satisfies: 0.6L≥R1≥0.3L. The maximum distance between the groove (61) and the peripheral blade (11) on the side near the circumferential surface (23) of the cutter body is L1, which satisfies: 1.8L≥L1≥1.2L.

2. The split-type drilling tool according to claim 1, characterized in that: The width of the groove (61) gradually decreases from the peripheral chip removal groove (33) to the end face (24) of the cutter body.

3. The split-type drilling tool according to claim 1, characterized in that: The minimum distance between the groove (61) and the circumferential surface (23) of the blade body is L3, which satisfies: 6mm≥L3≥0mm.

4. The split-type drilling tool according to claim 3, characterized in that: L3 = 1.8 mm.

5. The split-type drilling tool according to claim 1, characterized in that: L=8.4mm, R1=5.0mm, L1=13.5mm.

6. The split-type drilling tool according to any one of claims 1 to 5, characterized in that: The groove (61) is symmetrically arranged about the symmetry plane C, which is perpendicular to the normal plane B.

7. The split-type drilling tool according to claim 6, characterized in that: The symmetrical plane C intersects with the plane of the bottom surface (52) of the vertical peripheral chip groove to form an intersection line J1. The angle between the intersection line J1 and the rotation center axis (27) is a, which satisfies: 20°≥a≥0°.

8. The split-type drilling tool according to claim 7, characterized in that: The intersection of the groove (61) and the plane of symmetry C forms an intersection line J2, which is a curve.

9. The split-type drilling tool according to claim 8, characterized in that: The radius of curvature of the intersection line J2 is R2, which satisfies: 2.5L≥R2≥1.5L.

10. The split-type drilling tool according to claim 9, characterized in that: The intersection line J2 includes a first line segment J21 and a second line segment J22. The first line segment J21 is connected to the end face (24) of the cutter body, and the second line segment J22 is connected to the peripheral chip removal groove (33). The first line segment J21 is an arc with a radius of R3; the second line segment J22 is an arc with a radius of R4 and is tangent to the first line segment J21, satisfying: 2.5L≥R3≥1.5L, R4>R3; or, the second line segment J22 is straight and is tangent to the first line segment J21.

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