Method of manufacturing a pcd cutter having internal cooling channels and a pcd cutter

Abstract

The application provides a manufacturing method of a PCD cutter with an internal cooling channel, comprising the following steps: providing a PCD cutter semi-finished product, wherein the PCD cutter semi-finished product comprises a shank part and a head part, the shank part is provided with an internal cooling channel which is axially through, and the head part is a composite structure of PCD and tungsten carbide; machining a first stepped part at one end of the shank part, machining a second stepped part at the tungsten carbide of the head part, and the diameter size of the second stepped part is slightly smaller than the hole diameter of the internal cooling channel of the first stepped part; machining a radial water outlet hole which is communicated with the internal cooling channel at the first stepped part; inserting and sealing the radial water outlet hole by using a plug, inserting the second stepped part into the internal cooling channel, and connecting the head part and the shank part by vacuum welding; removing the plug by laser machining to restore the communication between the radial water outlet hole and the internal cooling channel; machining the PCD of the head part to form a cutting edge, and completing the molding of the cutter.

Description

Technical Field

[0001] This invention belongs to the technical field of cutting tool processing equipment, specifically relating to a manufacturing method of a PCD cutting tool with an internal cooling channel and the PCD cutting tool itself. Background Technology

[0002] Polycrystalline diamond (PCD) cutting tools are widely used in high-precision applications such as machining non-ferrous metals, composite materials, and non-metallic materials due to their extremely high hardness, wear resistance, and cutting performance. To further improve the performance of PCD tools in high-speed or dry cutting environments, some tools are designed with an internal cooling structure. Coolant is directly delivered to the tool tip area through cooling channels inside the tool body to achieve efficient heat dissipation, chip removal, and extended service life.

[0003] However, the manufacturing of such PCD tools, especially the connection between the PCD tool tip and the tool holder, typically employs a brazing (vacuum welding) process. During brazing, due to the minute size of the internal cooling channels, the liquid brazing filler metal is highly susceptible to capillary action, easily seeping into and clogging these delicate internal cooling channels. Once the channels are blocked, the tool's internal cooling function fails, severely impacting its performance and lifespan, and even leading to its scrapping. In existing technologies, the difficulty in effectively controlling the clogging problem during brazing results in a generally low yield rate for PCD tools with internal cooling channels.

[0004] Therefore, how to efficiently and reliably prevent the internal cooling channels from becoming blocked during brazing, and ensure the channels remain unobstructed after brazing, thereby improving the yield of finished products, is a technical problem that urgently needs to be solved in the field of PCD internal cooling tool manufacturing. Summary of the Invention

[0005] In view of a series of technical problems existing in the prior art, the present invention proposes a manufacturing method for a PCD tool with an internal cooling channel and a PCD tool to solve the above problems.

[0006] According to a first aspect of the present invention, a method for manufacturing a PCD cutting tool with an internal cooling channel is provided, comprising:

[0007] S1: Provide a PCD tool semi-finished product, which includes a tool holder and a tool head. The tool holder has an axially through internal cooling channel, and the tool head is a composite structure of PCD and tungsten carbide.

[0008] S2: A first step is formed at one end of the tool holder, and a second step is formed at the tungsten carbide part of the tool head. The diameter of the second step is slightly smaller than the diameter of the internal cooling channel of the first step.

[0009] S3: A radial water outlet hole connected to the internal cooling channel is machined in the first stage section;

[0010] S4: Insert and seal the radial water outlet using a plug, insert the second stage into the inner cooling channel, and connect the tool head and tool holder by vacuum welding;

[0011] S5: Use laser processing to remove blockages to restore the connection between the radial water outlet and the internal cooling channel;

[0012] S6: Machining the PCD of the tool head to form the cutting edge, completing the tool forming.

[0013] This method solves the problem of brazing and plugging holes in internal cooling tools in the prior art, significantly improves the machining yield, and provides a reliable and efficient manufacturing method for the mass production of PCD tools.

[0014] In some specific embodiments, the internal cooling channel includes an outlet channel at the front end of the tool holder and an inlet channel at the rear end. The diameter of the inlet channel is in the range of 0.9-1.1 mm, and the diameter of the outlet channel is in the range of 0.1-0.3 mm. This arrangement helps to ensure a stable flow rate and pressure of the coolant, ensuring that the PCD tool obtains effective cooling during cutting.

[0015] In some specific embodiments, the inlet and outlet channels are connected by a conical transition. This arrangement ensures that the coolant flows smoothly and efficiently from the inlet channel to the outlet channel, optimizing overall cooling efficiency.

[0016] In some specific embodiments, the diameter of the first step portion is in the range of 0.9-1.1 mm, the length is in the range of 1-4 mm, and the first step portion and the tool holder portion are connected by a tapered transition.

[0017] In some specific embodiments, the diameter of the second segment is in the range of 0.15-0.25 mm, and the length is in the range of 0.1-0.3 mm.

[0018] In some specific embodiments, the diameter of the radial water outlet is taken in the range of 0.15-0.25 mm, and the distance from the axis of the radial water outlet to the end face of the first segment is taken in the range of 0.1-0.4 mm. This setting ensures effective discharge of coolant and optimizes the cooling effect.

[0019] In some specific embodiments, the plug is a short tungsten carbide rod. The short rod shape facilitates insertion and fixation within narrow channels, and also allows for precise removal by subsequent laser.

[0020] In some specific embodiments, radial water outlets extend through the first step to form at least two water outlets in the first step. This arrangement helps to provide a more uniform or sufficient coolant flow, improving the overall cooling efficiency and chip removal capacity of the tool, thereby further optimizing cutting performance and tool life.

[0021] In some specific embodiments, the distance between the axis of the radial water outlet and the cutting edge is taken within the range of 1.0-1.5 mm. Defining the precise distance between the axis of the radial water outlet and the cutting edge allows the coolant to be accurately sprayed onto the cutting area, maximizing cooling efficiency, effectively reducing cutting heat, preventing tool wear and workpiece burning, thereby significantly improving machining quality and tool life.

[0022] According to a second aspect of the present invention, a PCD cutting tool is provided, which is manufactured using the manufacturing method of a PCD cutting tool having an internal cooling channel as described above.

[0023] Compared with the prior art, the beneficial results of the present invention are as follows:

[0024] The present invention relates to a manufacturing method and a PCD tool with an internal cooling channel. During vacuum brazing, a high-melting-point, high-hardness tungsten carbide short rod or similar material is used to precisely and temporarily seal the radial cooling outlet holes inside the tool. The second stage of the tungsten carbide at the tool tip is inserted into the internal cooling channel to further seal the axial passage. This fundamentally solves the industry problem of brazing filler metal being drawn into the tiny cooling channels by capillary action, causing blockage. After brazing, high-precision laser processing technology is used to precisely remove the blockage, restoring the internal cooling channel to its unobstructed state. This method not only effectively prevents blockage of the internal cooling channel and significantly improves the manufacturing yield of PCD internally cooled tools, but also ensures the efficient operation of the internal cooling system and the precise spraying of coolant, thereby greatly improving the tool's cutting performance, extending its service life, and ultimately enhancing machining accuracy and efficiency. Attached Figure Description

[0025] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of the invention. Other embodiments and many anticipated advantages of the embodiments will be readily recognized as they become better understood through reference to the following detailed description. Elements in the drawings are not necessarily to scale. The same reference numerals refer to corresponding similar parts.

[0026] Figure 1 This is a flowchart of a manufacturing method for a PCD cutting tool with an internal cooling channel according to an embodiment of the present invention.

[0027] Figure 2This is a schematic diagram of the structure of the handle and head of a semi-finished cutting tool according to a specific embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram of the structure of forming the first step portion by machining the tool holder portion according to a specific embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of forming the second step portion by machining the cutting head according to a specific embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of a radial water outlet hole that is machined in the first step and connected to the internal cooling channel according to a specific embodiment of the present invention.

[0031] Figure 6 This is a schematic diagram of a blockage being inserted into and sealing a radial water outlet hole according to a specific embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of a structure in which the second step portion of the tool head and the tool holder portion are connected by vacuum welding through an internal cooling channel according to a specific embodiment of the present invention.

[0033] Figure 8 This is a schematic diagram of the tool structure after removing blockages using laser processing according to a specific embodiment of the present invention.

[0034] The meanings of the numbers in the figure are as follows: 1. Handle, 11. Liquid inlet channel, 12. Liquid outlet channel, 13. First stage, 14. Radial water outlet, 15. Tungsten steel short rod, 2. Cutting head, 21. PCD, 22. Tungsten carbide, 22. Second stage, 221. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0036] Figure 1 A flowchart illustrating a manufacturing method for a PCD tool with an internal cooling channel according to an embodiment of the present invention is shown, as follows. Figure 1 As shown, the method includes the following steps:

[0037] S1: Provide a PCD tool semi-finished product, which includes a tool holder and a tool head. The tool holder has an axially through internal cooling channel, and the tool head is a composite structure of PCD and tungsten carbide.

[0038] In a specific embodiment, Figure 2A schematic diagram of the handle and head of a semi-finished cutting tool according to a specific embodiment of the present invention is shown, as follows: Figure 2 As shown, the PCD cutting tool semi-finished product includes a tool holder 1 and a tool head 2. The tool holder 1 has an axially penetrating internal cooling channel, including a liquid inlet channel 11 at the rear end of the tool holder and a liquid outlet channel 12 at the front end. The tool head 2 is a composite structure of PCD 21 and tungsten carbide 22.

[0039] In a specific embodiment, the diameter of the inlet channel 11 is within the range of 0.9-1.1 mm, adaptable to coolant connectors or pipe connections, ensuring stable inlet pressure; the diameter of the outlet channel 12 is within the range of 0.1-0.3 mm, facilitating the formation of a high-pressure fine jet of coolant. The inlet channel 11 and outlet channel 12 are connected by a conical transition surface, which is beneficial for stable fluid flow and avoids dead zones in the fluid flow. The length of the handle portion 1 is within the range of 39.9-40.1 mm, and the depth of the inlet channel 11 is within the range of 19-21 mm. The diameter of the cutter head 2 is 1.5 mm, and its length is within the range of 0.95-1.05 mm.

[0040] S2: A first step is formed at one end of the tool holder, and a second step is formed at the tungsten carbide part of the tool head. The diameter of the second step is slightly smaller than the diameter of the internal cooling channel of the first step.

[0041] In a specific embodiment, Figure 3 A schematic diagram of the structure for forming the first step portion in the tool holder portion according to a specific embodiment of the present invention is shown, as follows: Figure 3 As shown, the diameter of the first step portion 13 is in the range of 0.9-1.1 mm, the length is in the range of 1-4 mm, and the first step portion 13 and the tool holder portion 1 are connected by a tapered transition. Figure 4 A schematic diagram of the structure for forming the second step portion by machining the cutting head according to a specific embodiment of the present invention is shown, as follows: Figure 4 As shown, the diameter of the second segment 221 is in the range of 0.15-0.25mm, and the length is in the range of 0.1-0.3mm. The size of the second segment 221 is slightly smaller than the diameter of the outlet channel 12, which facilitates the insertion-type mating connection.

[0042] S3: A radial water outlet hole that connects to the internal cooling channel is machined in the first stage.

[0043] In a specific embodiment, Figure 5 A schematic diagram of a radial water outlet hole communicating with an internal cooling channel in the first step section according to a specific embodiment of the present invention is shown, as follows: Figure 5As shown, the diameter of the radial water outlet 14 is within the range of 0.15-0.25 mm, and the distance from the axis of the radial water outlet 14 to the end face of the first stepped portion 13 is within the range of 0.1-0.4 mm. The radial water outlet 14 penetrates the first stepped portion 13 to form at least two water outlets in the first stepped portion 13. The design of multiple radial water outlets helps to form a multi-directional jet distribution, improves cooling uniformity, and adapts to complex cutting conditions.

[0044] S4: Insert and seal the radial water outlet using a plug, insert the second stage into the inner cooling channel, and connect the tool head and tool holder by vacuum welding.

[0045] In a specific embodiment, Figure 6 A schematic diagram illustrating the insertion and sealing of a radial water outlet hole according to a specific embodiment of the present invention is shown, as follows. Figure 6 As shown, the blockage is a short tungsten carbide rod 15. Figure 7 A schematic diagram of a structure according to a specific embodiment of the present invention is shown, in which the second step portion is inserted into the internal cooling channel and the tool head and tool holder portion are connected by vacuum welding. Figure 7 As shown, the second stage 221 of the cutter head 2 is inserted and mates with the axial inner cooling channel of the first stage 13. The cutter head and the cutter shank are connected by vacuum welding. During welding, the solder is blocked by the tungsten steel short rod 15, so the solder will not enter the liquid outlet channel 12 after the radial water outlet hole 14, thus avoiding blockage of the liquid outlet channel 12.

[0046] S5: Use laser processing to remove blockages to restore the connection between the radial water outlet and the internal cooling channel.

[0047] In a specific embodiment, Figure 8 A schematic diagram of a tool structure after removing blockages using laser processing according to a specific embodiment of the present invention is shown, such as... Figure 8 As shown, after welding and cooling, the blockage 15 is removed by laser ablation to restore the flow function of the radial water outlet 14. High-precision laser processing is usually used to ensure that the hole wall or internal cooling channel of the radial water outlet 14 is not damaged while removing the tungsten steel short rod 15, thereby restoring the connectivity between the radial water outlet 14 and the internal cooling channel.

[0048] S6: Machining the PCD of the tool head to form the cutting edge, completing the tool forming.

[0049] In a specific embodiment, the PCD 21 on the tool head is machined using precision grinding or laser dressing to form a cutting edge that meets the usage requirements. After this step, a high-performance PCD tool with an internal cooling channel is obtained, suitable for high-load, high-precision machining scenarios. After machining, the distance from the axis of the radial water outlet 14 to the cutting edge is within the range of 1.0-1.5mm, allowing the coolant to be precisely sprayed onto the cutting edge, effectively reducing heat accumulation during cutting.

[0050] The above manufacturing method yields a PCD cutting tool with stable structure and high cooling efficiency. This tool achieves a combination of controllable coolant spray, robust tool head connection, and efficient heat dissipation through precisely machined internal cooling channels, a tool head-holder mating structure, and vacuum welding and plugging processes. In particular, the tool head, composed of a PCD and tungsten carbide composite structure, possesses excellent cutting performance while forming an integral structure with the inserted and welded tool head. This not only ensures effective cooling of the cutting area but also significantly improves the tool's structural strength and service life. Therefore, this PCD cutting tool has broad industrial application prospects and is particularly suitable for precision machining scenarios in high-speed, high-precision, and high-temperature environments.

[0051] The specific embodiments of the present invention have been described above, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0052] In the description of this invention, it should be understood that the terms "upper," "lower," "inner," "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The simple fact that certain measures are recited in mutually different dependent claims does not indicate that combinations of these measures cannot be used for improvement. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A method for manufacturing a PCD cutting tool with an internal cooling channel, characterized in that, include: S1: Provide a PCD cutting tool semi-finished product, the PCD cutting tool semi-finished product includes a tool holder and a tool head, the tool holder has an axially penetrating internal cooling channel, the tool head is a composite structure of PCD and tungsten carbide, the internal cooling channel includes a liquid outlet channel at the front end and a liquid inlet channel at the rear end of the tool holder, the diameter of the liquid inlet channel is in the range of 0.9-1.1mm, and the diameter of the liquid outlet channel is in the range of 0.1-0.3mm; S2: A first step portion is formed at one end of the tool holder, and a second step portion is formed at the tungsten carbide part of the tool head. The diameter of the second step portion is slightly smaller than the aperture of the internal cooling channel of the first step portion. S3: A radial water outlet hole communicating with the internal cooling channel is machined in the first segment; S4: Insert and seal the radial water outlet hole with a plug, insert the second section into the inner cooling channel, and connect the cutter head and the cutter shank by vacuum welding. The plug is a short tungsten steel rod. S5: Use laser processing to remove the blockage to restore the connection between the radial water outlet and the internal cooling channel; S6: The PCD of the cutter head is machined to form a cutting edge, thus completing the tool forming.

2. The method for manufacturing a PCD cutting tool with an internal cooling channel according to claim 1, characterized in that, The inlet channel and the outlet channel are connected by a conical transition.

3. The method for manufacturing a PCD cutting tool with an internal cooling channel according to claim 1, characterized in that, The diameter of the first step portion is in the range of 0.9-1.1 mm, the length is in the range of 1-4 mm, and the first step portion and the tool holder portion are connected by a tapered transition.

4. The method for manufacturing a PCD cutting tool with an internal cooling channel according to claim 1, characterized in that, The diameter of the second segment is taken in the range of 0.15-0.25mm, and the length is taken in the range of 0.1-0.3mm.

5. The method for manufacturing a PCD cutting tool with an internal cooling channel according to claim 1, characterized in that, The diameter of the radial water outlet is taken in the range of 0.15-0.25mm, and the distance from the axis of the radial water outlet to the end face of the first segment is taken in the range of 0.1-0.4mm.

6. The method for manufacturing a PCD cutting tool with an internal cooling channel according to claim 1 or 5, characterized in that, The radial water outlet hole penetrates the first step section to form at least two water outlet holes in the first step section.

7. The method for manufacturing a PCD cutting tool with an internal cooling channel according to claim 1 or 5, characterized in that, The distance between the axis of the radial water outlet and the cutting edge is taken from 1.0-1.5mm.

8. A PCD cutting tool, characterized in that, It is manufactured using the manufacturing method of a PCD tool with an internal cooling channel as described in any one of claims 1 to 7.

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