Large-size drilling tool based on CVD diamond compact and manufacturing method of large-size drilling tool

Abstract

The invention discloses a large-size hole forming cutter based on a CVD diamond compact and a manufacturing method of the large-size hole forming cutter, and belongs to the field of diamond cutters. The large-size hole forming cutter based on the CVD diamond compact comprises a cutter body, and a first CVD diamond is arranged at the top end of the cutter body; a plurality of sets of second CVD diamonds and third CVD diamonds which are located on the two sides of the cutter body in pairs are arranged below the first CVD diamonds, the first CVD diamonds, the second CVD diamonds and the third CVD diamonds are all welded to the cutter body through hard alloy transition layers, and the cutter body is provided with an anti-chip groove. According to the large-size drilling tool based on the CVD diamond and the manufacturing method of the large-size drilling tool, the problems that an existing tool provided in the background technology is insufficient in abrasion resistance and low in interface bonding strength, and a large-size cutting edge is prone to layering are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of diamond tools, and in particular to a large-size hole-making tool based on a CVD diamond composite sheet and a manufacturing method thereof. Background Art

[0002] Currently, large-scale hole making (such as holes in aircraft skins made of composite aerospace materials, shaft holes for wind turbine turbines, and drilling tools for oil and gas pipelines) places stringent demands on cutting tools. These tools are subject to higher torque and radial forces during large-diameter machining, making them susceptible to edge chipping. Traditional carbide cutting tools offer insufficient wear resistance and a short lifespan. PCD (polycrystalline diamond) cutting tools have low interfacial bonding strength, making large cutting edges prone to delamination.

[0003] CVD diamond (Chemical Vapor Deposited Diamond) maintains stable performance at temperatures up to 800°C. Using it on cutting tools effectively prevents edge softening and chemical corrosion caused by cutting heat. CVD diamond grains exhibit isotropic orientation, allowing for greater designability of cutting directions and making it suitable for large-scale continuous cutting. Therefore, the development of a large-scale hole-making tool based on CVD diamond composite sheets and its fabrication method are of great significance. Summary of the Invention

[0004] The purpose of the present invention is to provide a large-size hole-making tool based on CVD diamond composite sheet and its manufacturing method, so as to solve the problems of insufficient wear resistance, low interface bonding strength and easy delamination of large-size cutting edges of existing tools raised in the above background technology.

[0005] To achieve the above-mentioned objectives, the present invention provides a large-size hole-making tool based on a CVD diamond composite sheet, comprising a tool body, a CVD diamond 1 being provided at the top of the tool body, a plurality of groups of CVD diamond 2 and CVD diamond 3 being arranged in pairs on both sides of the tool body below the CVD diamond 1, CVD diamond 1, CVD diamond 2 and CVD diamond 3 being welded to the tool body through a cemented carbide transition layer, and an anti-chip groove being provided on the tool body.

[0006] Preferably, the CVD diamond is provided with an extrusion end edge, an extrusion edge, an extrusion auxiliary edge at the top, and a cutting edge and a radial cutting edge at both sides;

[0007] The extruded end blade, extruded edge and extruded auxiliary edge enter the interior of the processed material (the workpiece to be processed) through extrusion. The tip angle of the extruded end blade, extruded edge and extruded auxiliary edge ranges from 60° to 150°, and the back angle of the cutting edge ranges from 3° to 15°.

[0008] Preferably, the second CVD diamond and the third CVD diamond are both provided with a second cutting edge and a gauge edge;

[0009] The included angle range of the gauge blade is 0°-5°, the back angle range of the gauge blade is 7°-20°, the cutting edge of the gauge blade includes a milling cutter cutting edge and a continuously changing reamer blade band, and the reamer blade width is 0 to 0.2 mm.

[0010] Preferably, a buffer structure is provided at the lower end of the blade body, and the buffer structure includes a buffer body. The buffer body is provided at the bottom end of the blade body, and the buffer body is slidably provided inside the buffer seat.

[0011] Preferably, the bottom end of the buffer body is provided with a buffer column 1 and several buffer columns 2 arranged in an array around the buffer column 1, and a buffer column 3 is provided in the middle of the bottom end of the buffer column 1. The buffer column 3 is connected to the inner bottom end of the buffer seat through several evenly arranged shock absorber 1s.

[0012] Preferably, the second buffer column is connected to the inner bottom end of the buffer seat through the second shock absorber.

[0013] Preferably, a sliding column is arranged in an array around the buffer column 2, and a spring is provided on the sliding column. The spring is arranged between the bottom end of the buffer column 1 and the inner bottom end of the buffer seat. A sliding hole adapted to the sliding column is provided on the buffer column 1. The top end of the sliding column is inserted into the sliding hole and is slidably connected to the sliding hole. The bottom end of the sliding column is connected to the inner bottom end of the buffer seat.

[0014] Preferably, the inner diameter of the spring is larger than the diameter of the sliding hole.

[0015] Preferably, the bottom surfaces and side surfaces of CVD diamond one, CVD diamond two, and CVD diamond three are all welded to the blade body.

[0016] The present invention also provides a method for manufacturing a large-size hole-making tool based on a CVD diamond composite sheet, comprising the following steps:

[0017] Step 1: Diamond sheet production:

[0018] Select high-quality triangular polycrystalline CVD diamond sheets and high-quality rhombus polycrystalline CVD diamond sheets, and cut them into diamond sheets with a set contour shape using a YAG laser; grind and polish the bottom surface and welding side of the diamond sheets using a diamond flat grinder, and round the edges of the diamond sheet where the welding side contacts the bottom surface of the diamond sheet; remove surface dirt, scrub clean and set aside;

[0019] Step 2: Making the blade:

[0020] The prepared metal powder is fed into a press for compaction, and then compacted according to the different requirements of the cutter body, and then subjected to high-temperature hardening treatment. After the cutter body is manufactured, the welding grooves and chip return grooves for the CVD diamond parts are cut on the front and side of the cutter body by wire cutting. The width and depth of the welding grooves match the composite sheet.

[0021] Step 3, CVD diamond welding:

[0022] The cemented carbide transition layer is first vacuum welded to the CVD diamond sheet. The welding furnace is evacuated to high vacuum, and then heating is started and the temperature is controlled.

[0023] Step 4: Use high-frequency heating to weld the CVD diamond of the carbide transition layer completed in step 3 to the cutter body. Weld a layer of solder on the inner surface of the welding groove of the cutter body at high temperature, and achieve welding at a set temperature. During the welding process, the two diamond gauge edges are evenly and symmetrically positioned to expose the cutter head.

[0024] Therefore, the present invention adopts the above-mentioned large-size hole-making tool based on CVD diamond composite sheet and its manufacturing method, which has the following beneficial effects:

[0025] (1) The present invention uses ultra-hard and wear-resistant CVD diamond to make the blade tip, and the intersection angle of each blade surface of the blade tip is large, which has stronger anti-extrusion and impact resistance;

[0026] (2) The present invention has a simple structure and uses a simple-shaped diamond tip on a complex tool, thereby simplifying the complex tool;

[0027] (3) In the field of precision machining, the CVD diamond drilling tool of the present invention shows significant advantages, with high drilling efficiency and long service life;

[0028] (4) When the diamond tool of the present invention is making a hole, the sliding column slides in the sliding hole, and the combined structure of the two groups of buffers and the springs between the two groups of buffers achieves a buffering effect, thereby improving the quality of the hole making.

[0029] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a large-size hole-making tool based on a CVD diamond composite sheet according to the present invention;

[0031] Figure 2 This is a schematic diagram of a multi-tool head structure of an embodiment of a large-size hole-making tool based on a CVD diamond composite sheet according to the present invention;

[0032] Figure 3 This is a schematic diagram of the top CVD diamond structure of an embodiment of a large-size hole-making tool based on a CVD diamond compact according to the present invention;

[0033] Figure 4 This is a schematic diagram of a paired CVD diamond structure on both sides of an embodiment of a large-size hole-making tool based on a CVD diamond compact of the present invention;

[0034] Figure 5 A bottom view of a buffer structure of an embodiment of a large-size hole-making tool based on a CVD diamond composite sheet according to the present invention;

[0035] Figure 6 This is a schematic diagram of the internal structure of a buffer structure of an embodiment of a large-size hole-making tool based on a CVD diamond composite sheet of the present invention.

[0036] Reference numerals

[0037] 1. CVD diamond one; 2. Cutter body; 3. CVD diamond two; 4. CVD diamond three; 5. Chip return groove; 6. Extruded end edge; 7. Extruded edge; 8. Extruded auxiliary edge; 9. Cutting edge one; 10. Radial cutting edge; 11. Tip angle; 12. Cutting edge two; 13. Gauge edge; 14. Buffer body; 15. Buffer seat; 16. Buffer column one; 17. Buffer column two; 18. Buffer column three; 19. Shock absorber one; 20. Shock absorber two; 21. Sliding column; 22. Spring; 23. Sliding hole. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the embodiments of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar numbers throughout represent the same or similar elements or elements with the same or similar functions.

[0039] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or devices.

[0040] Like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0041] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0042] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0043] Example

[0044] like Figure 1 As shown, the large-scale hole-making tool based on CVD diamond compacts according to the present invention includes a cutter body 2, with a CVD diamond core 1 disposed at its top. Below CVD diamond core 1 are several pairs of CVD diamond cores 3 and 4 positioned on either side of the cutter body 2. Each of these CVD diamond cores 1, 3, and 4 is welded to the cutter body 2 via a cemented carbide transition layer. The cutter body 2 is provided with a chip countersink.

[0045] CVD diamond cutting tools use pure diamond generated by chemical vapor deposition technology as the cutting head material, without metal binders. They are cut into the required shape by laser and then fixed to the carbide or high-speed steel cutting body 2 by vacuum welding and high-frequency welding composite process technology, avoiding delamination failure and ensuring the integrity and high wear resistance of the cutting tool.

[0046] like Figure 3 As shown, the CVD diamond 1 is provided with an extruded end edge 6, an extruded edge 7, an extruded auxiliary edge 8 at the top and a cutting edge 9 and a radial cutting edge 10 at both sides; the extruded end edge 6, the extruded edge 7, and the extruded auxiliary edge 8 enter the interior of the processed material through extrusion, and the tip angle 11 at the extruded end edge 6, the extruded edge 7, and the extruded auxiliary edge 8 ranges from 60° to 150°, and the back angle of the cutting edge 9 ranges from 3° to 15°.

[0047] like Figure 4As shown, CVD diamond 2 3 and CVD diamond 3 4 are both provided with a cutting edge 2 12 and a gauge edge 13; the included angle range of the gauge edge 13 is 0°-5°, the back angle range of the gauge edge 13 is 7°-20°, and the cutting edge of the gauge edge 13 includes a milling cutter cutting edge and a continuously changing reamer blade band, and the reamer blade width is 0 to 0.2 mm.

[0048] like Figure 5 、 Figure 6 As shown, a buffer structure is provided at the lower end of the blade body 2. The buffer structure includes a buffer body 14. The buffer body 14 is provided at the bottom end of the blade body 2 and is slidably provided inside a buffer seat 15. A buffer column 16 and a plurality of buffer columns 2 17 arranged in an array around the buffer column 16 are provided at the bottom end of the buffer body 14. A buffer column 3 18 is provided in the middle of the bottom end of the buffer column 16. The buffer column 3 18 is connected to the inner bottom end of the buffer seat 15 via a plurality of evenly arranged shock absorbers 19. The buffer column 2 17 is connected to the inner bottom end of the buffer seat 15 via shock absorbers 20. Sliding columns 21 are arranged in an array around the buffer column 2 17, and a spring 22 is sleeved on the sliding column 21. The spring 22 is provided between the bottom end of the buffer column 16 and the inner bottom end of the buffer seat 15. The buffer column 16 is provided with a sliding hole 23 adapted for the sliding column 21. The top end of the sliding column 21 is inserted into the sliding hole 23 and slidably connected therewith. The bottom end of the sliding column 21 is connected to the inner bottom end of the buffer seat 15. The inner diameter of the spring 22 is larger than the diameter of the sliding hole 23.

[0049] The diamond processing size can be in the millimeter level. The processed diamond refers to pure diamond, which can be CVD polycrystalline diamond, single crystal diamond or natural diamond. In the following examples, the diamond raw material is processed by high-quality triangular polycrystalline CVD diamond slices with a thickness of 2.2 mm.

[0050] The present invention also provides a method for manufacturing a large-size hole-making tool based on a CVD diamond composite sheet, comprising the following steps:

[0051] Step 1: Diamond sheet production:

[0052] Select one 2.2mm thick high-quality triangular polycrystalline CVD diamond sheet and two 2.2mm thick high-quality rhombus polycrystalline CVD diamond sheets, and use YAG laser to cut them into the following shapes: Figure 1 The diamond sheet is of a contour shape; the lower bottom surface and the welding side of the diamond sheet obtained above are ground and polished by a diamond flat grinder to a thickness of 2.00 mm, and the diamond surface roughness reaches the mirror level. The edge of the diamond sheet welding side and the diamond bottom surface contact edge is rounded by R0.2 mm; remove surface dirt, scrub clean and set aside;

[0053] Step 2, production of the blade body 2: The prepared metal powder (such as tungsten carbide powder and cobalt powder, etc.) is sent into the press for pressing, and the pressing is carried out according to the different needs of the blade body 2. The maximum pressure can reach 12 tons to ensure the firmness of the blade body 2. Although the inside of the pressed blade body 2 is tight, it is very fragile, so it needs to be hardened at high temperature to make the particles inside the blade more tightly bonded, thereby improving the hardness and wear resistance. During the high-temperature hardening process, the organic binder will be consumed. After completion, the products need to be inspected one by one to ensure that the size and precision are qualified. After the blade body 2 is produced, the welding groove and chip return groove 5 for the CVD diamond part are opened at the front and side of the blade body 2 by wire cutting. The width and depth of the welding groove match the composite sheet;

[0054] Step 3. Large-size CVD diamond welding: vacuum weld the carbide transition layer to the CVD diamond sheet first. Pump the welding furnace to high vacuum, with a vacuum degree of 2*10-3Pa. Start heating until the heating chamber temperature reaches 880℃, keep warm for 0.5h, and then slowly cool down to below 200℃.

[0055] Step 4: Use high-frequency heating to weld the CVD diamond of the carbide transition layer completed in step 3 to the blade body 2. Use BAG612 welding sheet as solder. Weld a layer of solder on the inner surface of the welding groove of the blade body 2 at high temperature and realize welding at a temperature of 650℃-680℃. During the welding process, ensure that the two diamond gauge edges 13 are evenly and symmetrically exposed on the blade head.

[0056] The cutting edge is sharpened using a special diamond tool grinder. The cutting edge tip angle range can be 60°-150°, adjusted according to the hardness of the drilling material. For harder materials, the tip angle should be appropriately increased. The cutting edge clearance angle range can be 5°-10°. The gauge edge 13 is mainly used to ensure that the hole size meets the requirements.

[0057] like Figure 2 As shown, a structural diagram of a large-size hole-making tool based on CVD diamond provided by an embodiment of the present invention includes: 5 CVD diamond sheets; the large-size hole-making tool can adopt a combined cutter head made of large-size diamond at the end and multiple pairs of blades, multiple diamonds, and through the reasonable design of the extruded end blade 6, extruded edge 7, extruded auxiliary edge 8 and cutting edge, the integrity and high wear resistance of the tool are ensured and the cost can be reduced.

[0058] The embodiments of the present invention utilize ultra-hard, wear-resistant CVD diamond to create the cutting edge. The cutting edge features a large intersecting angle, resulting in strong resistance to compression and impact. When welding large diamonds to cemented carbide sheets, residual stress accumulates as the area increases after cooling to room temperature due to different thermal expansion coefficients. This significant residual stress can cause cracks in the diamond sheet, leading to weld failure. By pre-fabricating a cemented carbide transition layer, high-strength welding of the diamond and carbide sheets is achieved, resulting in a process-sustainable, fully functional drilling tool.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A large-size hole-making tool based on CVD diamond composite sheet, characterized by: It includes a cutter body, the top of which is provided with CVD diamond 1, and below which are provided several groups of CVD diamond 2 and CVD diamond 3 arranged in pairs on both sides of the cutter body. CVD diamond 1, CVD diamond 2 and CVD diamond 3 are all welded to the cutter body through a cemented carbide transition layer, and an anti-chip groove is provided on the cutter body.

2. The large-size hole-making tool based on CVD diamond composite sheet according to claim 1, characterized in that: The CVD diamond is provided with an extrusion end edge, an extrusion edge, an extrusion auxiliary edge at the top, and cutting edges and radial cutting edges at both sides; The tool tip angles at the extruded end edge, the extruded edge, and the extruded auxiliary edge range from 60° to 150°, and the back angle of the cutting edge ranges from 3° to 15°.

3. The large-size hole-making tool based on CVD diamond compact according to claim 1, characterized in that: CVD diamond No. 2 and CVD diamond No. 3 are both provided with cutting edge No. 2 and gauge edge; The included angle range of the gauge blade is 0°-5°, the back angle range of the gauge blade is 7°-20°, the cutting edge of the gauge blade includes a milling cutter cutting edge and a continuously changing reamer blade band, and the reamer blade width is 0 to 0.2 mm.

4. The large-size hole-making tool based on CVD diamond compact according to claim 1, characterized in that: The lower end of the knife body is provided with a buffer structure, which includes a buffer body. The buffer body is provided at the bottom end of the knife body, and the buffer body is slidably provided inside the buffer seat.

5. The large-size hole-making tool based on CVD diamond compact according to claim 4, characterized in that: The bottom end of the buffer body is provided with a buffer column 1 and several buffer columns 2 arranged in an array around the buffer column 1. A buffer column 3 is provided in the middle of the bottom end of the buffer column 1. The buffer column 3 is connected to the inner bottom end of the buffer seat through several evenly arranged shock absorber 1s.

6. The large-size hole-making tool based on CVD diamond compact according to claim 5, characterized in that: The second buffer column is connected to the inner bottom end of the buffer seat through the second shock absorber.

7. The large-size hole-making tool based on CVD diamond compact according to claim 5, characterized in that: Sliding columns are arranged in an array around the buffer column 2, and a spring is provided on the sliding column. The spring is arranged between the bottom end of the buffer column 1 and the inner bottom end of the buffer seat. A sliding hole adapted to the sliding column is provided on the buffer column 1. The top end of the sliding column is inserted into the sliding hole and is slidably connected to the sliding hole. The bottom end of the sliding column is connected to the inner bottom end of the buffer seat.

8. The large-size hole-making tool based on CVD diamond compact according to claim 7, characterized in that: The inner diameter of the spring is larger than the diameter of the sliding hole.

9. The large-size hole-making tool based on CVD diamond compact according to claim 1, characterized in that: The bottom surfaces and side surfaces of CVD diamond one, CVD diamond two and CVD diamond three are all welded to the cutter body.

10. A method for manufacturing a large-size hole-making tool based on a CVD diamond composite sheet, characterized by: The large-size hole-making tool based on a CVD diamond composite sheet according to any one of claims 1 to 9 is used, comprising the following steps: Step 1: Diamond sheet production: Select high-quality triangular polycrystalline CVD diamond sheets and high-quality rhombus polycrystalline CVD diamond sheets, and cut them into diamond sheets with a set contour shape using a YAG laser; grind and polish the bottom surface and welding side of the diamond sheets using a diamond flat grinder, and round the edges of the diamond sheet where the welding side contacts the bottom surface of the diamond sheet; remove surface dirt, scrub clean and set aside; Step 2: Making the blade: The prepared metal powder is fed into a press for compaction, and then compacted according to the different requirements of the cutter body, and then subjected to high-temperature hardening treatment. After the cutter body is manufactured, the welding grooves and chip return grooves for the CVD diamond parts are cut on the front and side of the cutter body by wire cutting. The width and depth of the welding grooves match the composite sheet. Step 3, CVD diamond welding: The cemented carbide transition layer is first vacuum welded to the CVD diamond sheet. The welding furnace is evacuated to high vacuum, and then heating is started and the temperature is controlled. Step 4: Use high-frequency heating to weld the CVD diamond of the carbide transition layer completed in step 3 to the cutter body. Weld a layer of solder on the inner surface of the welding groove of the cutter body at high temperature, and achieve welding at a set temperature. During the welding process, the two diamond gauge edges are evenly and symmetrically positioned to expose the cutter head.

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