Internal and external double-microgroove cooperative type drilling tool and design method

Abstract

The invention relates to the technical field of drilling tools, and discloses an inner and outer double-microgroove cooperative type drilling tool and a design method.The microgroove structure comprises an outer microgroove, an inner microgroove and a plurality of sets of microchannels, the outer microgroove and the microchannels are connected with the inner microgroove, the depth of the outer microgroove is smaller than that of the inner microgroove, and the inner microgroove is communicated with the outer microgroove. The junction of the outer microgroove and the inner microgroove is in smooth transition; the outer microgrooves can reduce the contact length between the cutter and the interior of cuttings and reduce thermal load, and the inner microgrooves can transfer thermal load of part of a cutting area, so that frictional wear of a near-cutting-edge area is reduced, the curling radius of the cuttings is reduced, and the chip curling capacity is improved; the micro-channel improves the permeability of external cutting fluid to a contact area of a cutter and cuttings in a non-dry cutting state. According to the design method of the inner microgroove, accurate construction of the geometrical shape of a real abrasion area is achieved, the matching degree of the inner microgroove and the actual cutting condition is improved, and the design reliability is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of drilling tools, in particular to an inner and outer double micro-groove cooperative drilling tool and a design method thereof. Background Art

[0002] As a common hole processing method, indexable insert drilling can achieve smooth drilling of the drill into the workpiece and maintain an excellent cutting force balance, effectively improving the feed rate of the processing process. In addition, the indexable insert can be directly replaced without regrinding after wear, which not only reduces material costs, but also makes it easier to control the consistency of the insert.

[0003] The processing diameter of indexable inserts is higher than that of ordinary drills, and can reach a maximum of D50~60mm, which well meets the needs of large-diameter drilling. The existing indexable inserts used in drilling mainly include quadrilaterals, convex triangles, rhombuses, hexagons, etc., which are subjected to severe drilling thermal loads and torque during use, which can easily cause tool wear and even chipping, seriously affecting the service life of the tool.

[0004] Traditionally, there is a way to reduce cutting temperature and improve blade durability by setting microgrooves near the cutting edge, but its structure still has certain shortcomings. The improvement effect on reducing thermal load is general. For the cutting process lubricated by cutting fluid, how the cutting fluid enters the tool-chip contact area is not considered. The microgrooves are only suitable for improving thermal loads under dry cutting conditions. Moreover, the design of the microgroove structure relies on the temperature field distribution near the cutting edge obtained by simulation, and accurate matching with the actual cutting situation cannot be guaranteed. In view of the above problems, the present application is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide an inner and outer double micro-groove collaborative drilling tool and a design method, to improve the thermal load of the tool through the inner and outer double micro-groove structure, and to optimize the tool structure through a scientific design method to improve the matching degree between the micro-groove structure and the actual cutting situation.

[0006] The present invention is achieved through the following technical solutions.

[0007] The inner and outer double microgrooves cooperative drilling tool of the present invention comprises a rake face, a tool tip, a main cutting edge, a secondary cutting edge and a microgroove structure, wherein the two sides of the tool tip are respectively connected to the main cutting edge and the secondary cutting edge, the microgroove structure is arranged on the rake face, the microgroove structure comprises an outer microgroove, an inner microgroove and a microchannel, the microchannel is arranged in a plurality of groups, the outer microgroove and the microchannel are both connected to the inner microgroove, the depth of the outer microgroove is less than the depth of the inner microgroove, and the junction between the outer microgroove and the inner microgroove is a smooth transition, thereby reducing the contact length between the tool and the chip and reducing the thermal load.

[0008] Furthermore, the inner microgroove is in an irregular elliptical spherical shape, and the specific shape is determined according to a drilling tool design method.

[0009] Furthermore, one side of the outer microgroove is the inner microgroove, and the other side is the tool tip and the main cutting edge, that is, the outer microgroove is wrapped around the outer edge of the inner microgroove, and the outer microgroove is placed between the inner microgroove and the tool tip and the main cutting edge.

[0010] Optionally, the transverse cross-section of the outer microgroove is arc-shaped or triangular.

[0011] Optionally, the transverse cross-section of the microchannel is rectangular or arc-shaped.

[0012] Furthermore, the microchannels are arranged radially, with the radial center on one side of the inner microgroove, thereby forming microchannels arranged in a trumpet shape, and the large mouth is placed on the inner side of the tool. This arrangement helps to "gather" the cutting fluid, promotes more liquid penetration, makes it easier for the cutting fluid to enter the microchannel, and improves the lubrication efficiency.

[0013] Optionally, the minimum distance between the outer microgroove and the main cutting edge is 0.08-0.18 mm.

[0014] Optionally, the maximum depth of the outer microgrooves is 0.04-0.10 mm, and the width is 0.06-0.14 mm.

[0015] A drilling tool design method is used to design the inner microgroove in the above-mentioned inner and outer double microgroove cooperative drilling tool, comprising the following steps:

[0016] S1: Obtaining the boundary curve of the inner microgroove: Carry out the cutting experiment until the tool reaches the end of its service life. After removing the tool, draw a curve along the edge of the wear area to obtain the boundary curve of the inner microgroove;

[0017] S2: constructing a cross-sectional curve of the inner microgroove: setting a plurality of cross sections along the transverse direction of the wear area in step S1, and taking the intersection curve of the cross section and the wear area as the cross-sectional curve of the inner microgroove;

[0018] S3: forming an inner micro-groove curved surface: constructing a curved surface through a curve group using the cross-section curve in step S2 and the boundary curve in step S1, and each curved surface adopts tangent continuity between different parts to ensure a smooth transition of the curved surface;

[0019] S4: Obtaining inner microgrooves: Optimizing the smoothness and boundary conditions of the surface generated in step S3, and then obtaining inner microgrooves by shearing the surface with a tool.

[0020] Furthermore, the following steps are included: in step S2, the cross sections are arranged more densely in the mutation area of ​​the boundary curve. The reason is that the curve changes greatly in the area where the curvature changes greatly in the mutation area, and more dense interfaces are required for interception to obtain a cross-sectional shape that is closer to the wear area, and the modeling accuracy is higher.

[0021] Beneficial effects of the present invention:

[0022] The contact state between the tool and the chip is adjusted by setting the internal and external microgrooves. The role of the external microgrooves is to reduce the internal contact length between the tool and the chip, thereby reducing the thermal load and ensuring the tool strength requirements. On the one hand, the internal microgrooves can transfer the thermal load of part of the cutting area, thereby reducing the friction and wear of the area near the cutting edge and increasing the tool life. On the other hand, it can reduce the chip curling radius and improve the chip curling ability. The role of the microchannel is to improve the penetration performance of the external cutting fluid into the contact area between the tool and the chip under non-dry cutting conditions.

[0023] In summary, the tool of this scheme has the advantages of simple structure and reliable use, and is suitable for the use of indexable drilling tools in non-dry cutting conditions.

[0024] This scheme also achieves accurate construction of the geometry of the actual wear area through the design method of the internal microgroove, improves the matching degree between the internal microgroove and the actual cutting situation, effectively improves the reliability of the design, and enables the microgroove structure to better assist in improving the performance of the tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0027] Figure 1 It is a schematic diagram of the overall structure of the inner and outer double micro-groove cooperative drilling tool;

[0028] Figure 2 It is a schematic diagram of the structure at the microgroove structure;

[0029] Figure 3 for Figure 2 Sectional view at AA in the middle;

[0030] Figure 4 It is a diagram of the use state of the tool of the present invention;

[0031] Figure 5 for Figure 4 A partial enlarged view of the middle Ⅰ area;

[0032] Figure 6 It is the process of forming the boundary curve of the inner microgroove;

[0033] Figure 7 It is the process of forming the cross-section curve of the inner microgroove;

[0034] Figure 8 This is the formation process of the inner microgrooves;

[0035] In the figure:

[0036] 1-front cutting edge; 2-mounting hole; 3-secondary cutting edge; 4-tool tip; 5-inner microgroove; 6-outer microgroove; 7-microchannel; 8-main cutting edge; 9-workpiece; 10-chip; 11-boundary curve; 12-cross section; 13-section curve. DETAILED DESCRIPTION

[0037] Combine the following Figure 1-8 The present invention is described in detail.

[0038] Embodiment 1:

[0039] The inner and outer double micro-groove cooperative drilling tool of the present invention is as follows: Figure 1 , including a front cutting face 1 and a cutting edge 4. The cutting edges 4 can be arranged in several groups according to the shape of the tool. In this embodiment, three cutting edges 4 are arranged. The two sides of the cutting edges 4 are respectively connected to the main cutting edge 8 and the secondary cutting edge 3. A mounting hole 2 is arranged in the middle of the tool. A micro-groove structure is arranged on the front cutting face 1. The number of the micro-groove structure is preferably the same as that of the cutting edges 4.

[0040] The microgroove structure includes an outer microgroove 6, an inner microgroove 5 and a microfluidic channel 7. The outer microgroove 6 is arranged on the inner side of the knife tip 4, the inner microgroove 5 is arranged on the inner side of the outer microgroove 6, and several microfluidic channels 7 are arranged on the inner side of the inner microgroove 5. The two sides of the inner microgroove 5 are respectively connected with the outer microgroove 6 and the microfluidic channel 7.

[0041] The inner micro groove 5 is in an irregular elliptical spherical shape, and its shape is measured by the wear area of ​​the tool rake face 1 in the cutting experiment and is obtained by spline curve interpolation drawing.

[0042] The outer microgroove 6 is wrapped around the outer edge of the inner microgroove 5, and the outer microgroove 6 is placed between the inner microgroove 5 and the tool tip 4 and the main cutting edge 8. The depth of the outer microgroove 6 is less than the depth of the inner microgroove 5, and the junction between the outer microgroove 6 and the inner microgroove 5 is a smooth transition with a shape change, such as Figure 5 Middle M position.

[0043] like Figure 3 In this embodiment, the transverse cross-section of the outer microgroove 6 is preferably an arc shape, and the transverse cross-section of the microchannel 7 is preferably a rectangle.

[0044] like Figure 2 The microchannel 7 is arranged in a trumpet shape, and the large opening is placed on the inside, which is convenient for obtaining cutting fluid, helps to "gather" the cutting fluid, promotes more liquid penetration, makes it easier for the cutting fluid to enter the microchannel 7, and improves the lubrication efficiency.

[0045] The minimum distance between the outer micro groove 6 and the main cutting edge 8 is 0.08-0.18 mm. The maximum depth of the outer micro groove 6 is 0.04-0.10 mm, and the width is 0.06-0.14 mm.

[0046] When using, see Figures 4 to 5 First, the wear area of ​​the tool rake face is obtained through the cutting experiment of the drilling tool, and the irregular elliptical spherical inner microgroove 5 is obtained by spline curve interpolation. The appropriate outer microgroove 6 and inner microgroove 5, during the drilling process of the workpiece 9, the contact state between the tool and the chip 10 is as follows Figure 5 As shown, the chips are in a non-complete contact state in the outer microgroove 6 and the inner microgroove 5, thereby reducing the tool-chip contact length and weakening the thermal load. The contact areas, such as M, N, O, etc., are used to reduce the curling radius of the chips, improve the chip curling ability, and thus improve the overall performance of the drilling tool.

[0047] The setting of internal and external microgrooves adjusts the contact state between the tool and the chip. The function of the external microgrooves is to reduce the internal contact length between the tool and the chip 10, thereby reducing the thermal load and ensuring the tool strength requirements. On the one hand, the internal microgrooves can transfer the thermal load of part of the cutting area, thereby reducing the friction and wear of the area near the cutting edge and increasing the tool life. On the other hand, it reduces the chip curling radius and improves the chip curling ability. The function of the microchannel is to improve the penetration performance of the external cutting fluid into the contact area between the tool and the chip under non-dry cutting conditions.

[0048] Embodiment 2:

[0049] Based on Example 1, the minimum distance between the outer microgroove 6 and the main cutting edge 8 is 0.08 mm. The maximum depth of the outer microgroove 6 is 0.04 mm, and the width is 0.06 mm.

[0050] Embodiment 3:

[0051] Based on Example 1, the minimum distance between the outer microgroove 6 and the main cutting edge 8 is 0.13 mm. The maximum depth of the outer microgroove 6 is 0.07 mm, and the width is 0.10 mm.

[0052] Embodiment 4:

[0053] Based on Example 1, the minimum distance between the outer microgroove 6 and the main cutting edge 8 is 0.18 mm. The maximum depth of the outer microgroove 6 is 0.10 mm, and the width is 0.14 mm.

[0054] Embodiment 5:

[0055] On the basis of Example 1, in this example, the transverse cross-section of the outer microgroove 6 is triangular, and the transverse cross-section of the microchannel 7 is arc-shaped.

[0056] A drilling tool design method is used to design an inner microgroove in an inner and outer double microgroove cooperative drilling tool according to any of the above embodiments, comprising the following steps:

[0057] First, obtain the boundary curve 11 of the inner microgroove 5: Figure 6 , a cutting experiment is carried out until the tool reaches the end of its service life, and after removing the tool, the wear area of ​​the front cutting edge 1 is observed and obtained, and a curve is drawn along the edge of the wear area using a spline curve to obtain a boundary curve 11 of the inner microgroove 5;

[0058] Second, construct the cross-sectional curve 13 of the inner microgroove 5: Figure 7 , 6-10 cross sections 12 are arranged along the transverse direction of the wear area in step 1, and the intersection curve of the cross section 12 and the wear area is intercepted as the cross section curve 13 of the inner micro groove 5, wherein the cross section 12 is arranged more densely in the mutation area of ​​the boundary curve 11;

[0059] The reason why the mutation area is set more densely is that the curve of the area with large curvature changes in the mutation area changes greatly, and a denser interface is needed for interception to obtain a cross-sectional shape that is closer to the wear area, and the modeling accuracy is higher.

[0060] Third, forming the inner microgroove 5 curved surface: Figure 8 , using the cross-section curve 13 in step 2 and the boundary curve 11 in step 1 to construct a surface through a curve group, and each surface adopts tangent continuity between different parts to ensure a smooth transition of the surface;

[0061] Fourth, obtaining the inner microgroove 5: optimizing the smoothness and boundary conditions of the curved surface generated in step 3, and then obtaining the inner microgroove 5 by shearing the curved surface with a tool, and setting the outer microgroove 6 and the microchannel 7 on the basis of the inner microgroove 5.

[0062] The above design method can realize the accurate construction of the geometric shape of the real wear area, improve the matching degree between the internal micro-groove and the actual cutting situation, effectively improve the reliability of the design, and make the micro-groove structure better assist in improving the tool performance.

[0063] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology in this field to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. Internal and external double micro groove collaborative drilling tool, characterized by: The invention comprises a rake face (1), a blade tip (4), a main cutting edge (8), a secondary cutting edge (3) and a microgroove structure, wherein the two sides of the blade tip (4) are respectively connected to the main cutting edge (8) and the secondary cutting edge (3), the microgroove structure is arranged on the rake face (1), the microgroove structure comprises an outer microgroove (6), an inner microgroove (5) and a microfluidic channel (7), the microfluidic channel (7) is arranged in a plurality of groups, the outer microgroove (6) and the microfluidic channel (7) are both connected to the inner microgroove (5), the depth of the outer microgroove (6) is less than the depth of the inner microgroove (5), and the junction between the outer microgroove (6) and the inner microgroove (5) is a smooth transition.

2. The inner and outer double micro groove cooperative drilling tool according to claim 1, characterized in that: The inner microgroove (5) is in the shape of an irregular elliptical sphere.

3. The inner and outer double micro groove cooperative drilling tool according to claim 1, characterized in that: One side of the outer microgroove (6) is the inner microgroove (5), and the other side is the tool tip (4) and the main cutting edge (8).

4. The inner and outer double micro groove cooperative drilling tool according to claim 1 or 2, characterized in that: The transverse cross section of the outer microgroove (6) is arc-shaped or triangular.

5. The inner and outer double micro groove cooperative drilling tool according to claim 1 or 2, characterized in that: The transverse cross section of the microchannel (7) is rectangular or arc-shaped.

6. The inner and outer double micro groove cooperative drilling tool according to claim 5, characterized in that: The microchannels (7) are arranged radially, with the center of the radiation being located on one side of the inner microgroove (5).

7. The inner and outer double micro groove cooperative drilling tool according to claim 4, characterized in that: The minimum distance between the outer micro groove (6) and the main cutting edge (8) is 0.08-0.18 mm.

8. The inner and outer double micro groove cooperative drilling tool according to claim 7, characterized in that: The maximum depth of the outer microgrooves (6) is 0.04-0.10 mm, and the width is 0.06-0.14 mm.

9. A drilling tool design method for designing an inner microgroove in an inner and outer double microgroove cooperative drilling tool according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Obtaining the boundary curve (11) of the inner microgroove (5): Carrying out a cutting experiment on the tool, when the tool reaches the end of its service life, removing the tool and drawing a curve along the edge of the wear area to obtain the boundary curve (11) of the inner microgroove (5); S2: constructing a cross-sectional curve (13) of the inner microgroove (5): setting a plurality of cross sections (12) along the transverse direction of the wear region in step S1, and taking the intersection curve of the cross section (12) and the wear region as the cross-sectional curve (13) of the inner microgroove (5); S3: forming the inner microgroove (5) surface: constructing a surface through a curve group using the cross-sectional curve (13) in step S2 and the boundary curve (11) in step S1, the surface has a smooth transition, and the inner microgroove (5) is obtained by shearing the tool according to the surface.

10. The drilling tool design method according to claim 9, characterized in that: The following steps are also included: In step S2, the cross sections (12) are arranged more densely in the mutation area of ​​the boundary curve (11) than in other areas, so as to obtain a cross-sectional shape closer to the wear area.

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