Cutting tool

Abstract

The utility model discloses a cutting tool, cutting tool includes: blade, the blade includes intermediate layer and two cubic boron nitride layers, the intermediate layer is located between two cubic boron nitride layers, the body of knife, the intermediate layer is welded on the body of knife, one of the welding surface of body of knife and the welding surface of blade is equipped with tenon and is equipped with mortise on the other, the tenon is fitted in the mortise. Cutting tool according to the utility model embodiment has the advantages of facilitating to improve the bending strength and the anti -breakage ability, facilitating to reduce the cost, facilitating to reduce the welding stress, facilitating to improve the welding strength, facilitating to improve the service life and reliability of blade and the like.

Description

Technical Field

[0001] This utility model relates to the field of machining technology, and more specifically, to a cutting tool. Background Technology

[0002] When machining workpieces with high hardness and high precision, cemented carbide inserts cannot meet the precision requirements, and superhard inserts, such as cubic boron nitride (CBN) inserts, are required.

[0003] For semi-finishing and finishing, welded cubic boron nitride inserts are required.

[0004] The welded cubic boron nitride inserts in related technologies involve welding cubic boron nitride inserts onto a cemented carbide insert body. Due to the significant difference in the coefficients of thermal expansion between cubic boron nitride and cemented carbide, the welding stress is high, resulting in insufficient welding strength. During use, the inserts are easily subjected to high temperatures and high cutting forces, which can lead to breakage, detachment, and other situations that render them unusable. This results in short insert life, low utilization rate, and even scrapping of the workpiece. Utility Model Content

[0005] This utility model aims to solve at least one of the technical problems existing in the prior art. To this end, this utility model proposes a cutting tool that has the advantages of facilitating improved bending strength and chipping resistance, facilitating cost reduction, facilitating reduced welding stress, facilitating improved welding strength, and facilitating improved tool life and reliability.

[0006] To achieve the above objectives, a cutting tool is proposed according to an embodiment of the present invention. The cutting tool includes: an insert, the insert including an intermediate layer and two cubic boron nitride layers, the intermediate layer being located between the two cubic boron nitride layers; and a tool body, the intermediate layer being welded to the tool body, one of the welding surfaces of the tool body and the insert having a tenon and the other having a mortise, the tenon fitting into the mortise.

[0007] The cutting tool according to the embodiments of this utility model has the advantages of facilitating the improvement of bending strength and chipping resistance, facilitating the reduction of cost, facilitating the reduction of welding stress, facilitating the improvement of welding strength, and facilitating the improvement of tool life and reliability.

[0008] In addition, the cutting tool according to the above embodiments of the present invention may also have the following additional technical features: According to one embodiment of the present invention, the mortise includes at least two mating planes, and the included angle between the two mating planes is 50-130 degrees.

[0009] According to one embodiment of the present invention, the mortise further includes a rounded corner surface connecting the two mating planes, the radius of the rounded corner surface being greater than or equal to 0.2 mm.

[0010] According to one embodiment of the present invention, the blade is cut from a composite sheet material, the composite sheet material comprising an intermediate layer and two cubic boron nitride layers, the intermediate layer being located between the two cubic boron nitride layers.

[0011] According to one embodiment of the present invention, the blade is formed by laser cutting or wire cutting of the composite sheet material.

[0012] According to one embodiment of the present invention, the cubic boron nitride layer is sintered on the intermediate layer.

[0013] According to one embodiment of the present invention, the thickness of the cubic boron nitride layer is 0.5-1.5 mm. According to one embodiment of the present invention, there are multiple tenons and multiple mortises, and the multiple tenons are respectively fitted into the multiple mortises.

[0014] According to one embodiment of the present invention, the welding temperature between the blade and the blade body is 750-850℃.

[0015] According to one embodiment of the present invention, the particle size of the cubic boron nitride layer is 1-50 micrometers, and both the intermediate layer and the blade body are made of cemented carbide.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of a cutting tool according to some specific embodiments of the present invention.

[0018] Figure 2 This is an exploded view of a cutting tool according to some specific embodiments of the present invention.

[0019] Figure 3 This is a schematic diagram of the structure of a cutting tool according to some specific embodiments of the present invention.

[0020] Figure 4 This is a schematic diagram of the structure of a cutting tool according to some specific embodiments of the present invention.

[0021] Figure 5 This is a structural schematic diagram of a cutting tool according to some other specific embodiments of the present invention.

[0022] Figure 6 This is a structural schematic diagram of a cutting tool according to some other specific embodiments of the present invention.

[0023] Figure 7 This is a structural schematic diagram of a cutting tool according to some other specific embodiments of the present invention.

[0024] Figure 8 This is a schematic diagram of the cutting process of a cutting tool according to an embodiment of the present utility model.

[0025] Reference numerals: Cutting tool 1, Blade 10, Intermediate layer 11, Cubic boron nitride layer 12, Tool body 20, Mounting hole 21, Tenon 30, Mortise 40, Mating plane 41, Rounded corner 42, Composite sheet material 2, Material intermediate layer 3, Material cubic boron nitride layer 4. Detailed Implementation

[0026] This application is based on the findings and understanding of the following facts and issues: The welded cubic boron nitride inserts in related technologies are made by welding cubic boron nitride inserts onto a cemented carbide insert body. Due to the large difference in the coefficients of thermal expansion between cubic boron nitride and cemented carbide, the welding stress is large, resulting in insufficient welding strength. During use, the inserts are easily subjected to high temperatures and high cutting forces, which can lead to the inserts breaking, falling off, or becoming unusable. This results in short insert life, low utilization rate, and even scrapping of the workpiece.

[0027] Some cubic boron nitride inserts in related technologies use a layer of cubic boron nitride sintered directly onto the outer surface of the cemented carbide to avoid welding difficulties. However, this method is costly and limited by size, making it suitable only for finishing and not for semi-finishing or roughing.

[0028] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0029] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model 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 this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0030] The cutting tool 1 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0031] like Figures 1-8 As shown, the cutting tool 1 according to an embodiment of the present invention includes a blade 10 and a tool body 20.

[0032] The blade 10 includes an intermediate layer 11 and two cubic boron nitride layers 12, with the intermediate layer 11 located between the two cubic boron nitride layers 12. The intermediate layer 11 is welded to the blade body 20. One of the welding surfaces of the blade body 20 and the blade 10 is provided with a tenon 30 and the other is provided with a mortise 40, with the tenon 30 fitting into the mortise 40.

[0033] It is important to understand here that "welding" refers to the structural relationship between the blade 10 and the blade body 20, not the manufacturing method.

[0034] Specifically, the intermediate layer 11 and the blade body 20 can be made of the same or similar materials with similar coefficients of thermal expansion.

[0035] According to the present invention, the cutting tool 1 includes an intermediate layer 11 and two cubic boron nitride layers 12 in the insert 10. The intermediate layer 11 is located between the two cubic boron nitride layers 12. The cubic boron nitride layers 12 can be used to ensure the hardness of the cutting surface of the insert 10, facilitating high-hardness and high-precision machining. Moreover, the intermediate layer 11 can be made of a material with high toughness. Compared with inserts made entirely of cubic boron nitride in related technologies, this improves the overall bending strength of the insert 10, making it less prone to chipping. It retains the strength of the cubic boron nitride material while also taking into account the toughness of the intermediate layer 11. The intermediate layer 11 can also be made of a lower-cost material, which can reduce the material cost of the insert 10.

[0036] Furthermore, by welding the intermediate layer 11 to the tool body 20, the intermediate layer 11 and the tool body 20 can be made of the same or similar materials with similar coefficients of thermal expansion. Compared with related technologies that directly weld cubic boron nitride to cemented carbide, this avoids the problems of high welding stress and insufficient welding strength caused by different materials and coefficients of thermal expansion. It improves the welding strength between the insert 10 and the tool body 20, avoids the situation where the insert 10 breaks off and cannot be used, improves the service life and utilization rate of the insert, and avoids the workpiece being scrapped due to the insert 10 breaking off.

[0037] Furthermore, by providing a tenon 30 on one of the welding surfaces of the cutter body 20 and the cutting tool 10, and a mortise 40 on the other, with the tenon 30 fitting into the mortise 40, a tenon-mortise interlocking welding structure can be formed. The fit between the tenon 30 and the mortise 40 can resist the transverse cutting force during turning, further improving the welding strength of the cutting tool 10, preventing the cutting tool 10 from falling off, further improving the service life of the cutting tool 10, and further improving the reliability of the cutting tool 10 during use.

[0038] Therefore, the cutting tool 1 according to the present utility model has advantages such as easy improvement of bending strength and chipping resistance, easy reduction of cost, easy reduction of welding stress, easy improvement of welding strength, and easy improvement of tool life and reliability.

[0039] The cutting tool 1 according to a specific embodiment of the present invention is described below with reference to the accompanying drawings.

[0040] In some specific embodiments of this utility model, such as Figures 1-8 As shown, the cutting tool 1 according to an embodiment of the present invention includes a blade 10 and a tool body 20.

[0041] Specifically, such as Figure 4 As shown, the mortise 40 includes at least two mating planes 41, and the included angle α between the two mating planes 41 is 50-130 degrees. This further enables the tenon 30 and the mortise 40 to effectively resist the lateral cutting force of the blade 10 during use.

[0042] More specifically, such as Figure 4 As shown, the mortise 40 also includes a rounded corner surface 42 connecting the two mating planes 41, and the radius R of the rounded corner surface 42 is greater than or equal to 0.2 mm. Specifically, the radius R of the rounded corner surface 42 is less than or equal to 1.2 mm. This can effectively reduce stress concentration at the rounded corner surface 42, increase the welding area, and prevent the blade 10 from falling off or breaking.

[0043] Advantageously, such as Figure 8 As shown, the blade 10 is cut from a composite sheet material 2. The composite sheet material 2 includes a material intermediate layer 3 and two material cubic boron nitride layers 4, with the material intermediate layer 3 located between the two material cubic boron nitride layers 4. Specifically, firstly, the material cubic boron nitride layers 4 are sintered on both sides of the larger material intermediate layer 3 under high temperature and pressure using a top press to form the composite sheet material 2. Then, the composite sheet material 2 is cut to form the blade 10. It is important to understand that "cutting" is a limitation on the structure of the blade 10, not a limitation on the processing method of the blade 10. By first sintering the material cubic boron nitride layers 4 on both sides of the material intermediate layer 3 to form the composite sheet material 2, and then cutting the blade 10 from the composite sheet material 2, the structure of the blade 10 itself differs from other manufacturing methods. This facilitates the forming of the blade 10, reduces the production cost of the blade 10, and also facilitates the welding of the blade 10 to the blade body 20.

[0044] Alternatively, the blade 10 is formed by laser cutting or wire cutting of the composite sheet material 2. This further facilitates the forming of the blade 10.

[0045] For example, firstly, the composite sheet material 2 is clamped in a laser cutting machine, and the required number of blades 10 are processed by laser cutting; a certain amount of flux is applied to the groove 40, and the blades 10 and the blade body 20 are assembled together; by vacuum welding, with the temperature controlled at 750℃-850℃, the blades 10 and the blade body 20 are welded together to form the cutting tool 1; the cutting tool 1 is placed on a surface grinder, and the thickness of the cutting tool 1 is ground to the required size; by CNC peripheral grinding, the periphery of the cutting tool 1 is machined to the required size, and the cutting edge is chamfered; the cutting edge is blunted using a cutting edge blunting device; and the blade is coated.

[0046] Optionally, the cubic boron nitride layer 12 is sintered on the intermediate layer 11. It is important to understand that "sintering" is a limitation on the structure of the cubic boron nitride layer 12, not a limitation on its preparation method. This facilitates the formation of the cubic boron nitride layer 12 on both sides of the intermediate layer 11, thereby improving the bonding strength between the cubic boron nitride layer 12 and the intermediate layer 11.

[0047] Optionally, the thickness of the cubic boron nitride layer 12 is 0.5-1.5 mm. This not only makes it easier to ensure the hardness of the cubic boron nitride layer 12, but also makes it easier to control material costs.

[0048] Taking the blade 10 with a thickness of 4.76 mm and the cubic boron nitride layer 12 with a thickness of 1 mm as an example, the thickness of the intermediate layer 11 is 2.76 mm, and the cemented carbide accounts for 57.98%. Compared with blades that use cubic silicon nitride material as the whole in related technologies, the amount of cubic silicon nitride material can be reduced by 57.98%, which can significantly reduce the material cost of tool manufacturing.

[0049] In some embodiments, such as Figure 6 As shown, there are multiple tenons 30 and mortises 40, and each tenon 30 is fitted into a multiple mortise 40. In this way, the multiple tenons 30 and multiple mortises 40 can share the transverse cutting force on the blade 10, thereby further improving the welding strength between the blade 10 and the blade body 20.

[0050] In some embodiments, such as Figures 1-6 As shown, the tenon 30 can be provided on the blade 10 and the mortise 40 can be provided on the blade body 20. In other embodiments, such as Figure 7 As shown, the tenon 30 can be provided on the cutter body 20 and the mortise 40 can be provided on the blade 10.

[0051] In some embodiments, such as Figures 1-4 As shown, the width of each tenon 30 can be equal to the width of the blade 10. In other embodiments, such as Figures 5-7 As shown, the width of each tenon 30 can also be less than the width of the blade 10.

[0052] Optionally, the welding temperature between the blade 10 and the blade body 20 is 750-850℃. Specifically, the blade 10 can be vacuum welded to the blade body 20. This facilitates improving the welding strength between the blade 10 and the blade body 20.

[0053] Optionally, the cubic boron nitride layer 12 has a particle size of 1-50 micrometers, and both the intermediate layer 11 and the blade body 20 are made of cemented carbide. Specifically, the intermediate layer 11 can be made of YG6 or YG8 material. This facilitates ensuring the hardness and precision of the cubic boron nitride layer 12, and also ensures the structural strength and toughness of the intermediate layer 11.

[0054] In related technologies, the difference in the coefficient of thermal expansion between cubic silicon nitride inserts and cemented carbide insert bodies is approximately 3 × 10⁻⁶. -6 / K, while the difference in the welding thermal expansion coefficients of the same grade of cemented carbide insert 10 and cutter body 20 is less than 0.5×10. -6 / K can significantly reduce the difference in thermal expansion coefficients, reduce welding stress, and improve welding strength.

[0055] Specifically, the cutter body 20 is provided with a mounting hole 21. The cutter body 20 can be mounted on the cutter shank by means of a threaded fastener that fits into the mounting hole 21.

[0056] Experiments have verified that the shear strength of cubic boron nitride inserts welded to carbide tool bodies in related technologies is approximately 200–300 MPa, and the tensile strength is less than 100 MPa. However, the cutting tool 1 of this invention, welded to the carbide-carbide body 20 via an intermediate layer 11, exhibits a shear strength of 350–500 MPa, with a bending strength decrease of less than 15% after welding. While the compressive strength of cubic boron nitride inserts welded to carbide tool bodies in related technologies is 1083.57 N, the compressive strength of the insert 10 and tool body 20 in the cutting tool 1 of this invention is 1635.82 N, representing a 50.97% increase in welding strength compared to the previous method.

[0057] Experiments were conducted by continuously machining half-shaft gears. The material was hardened steel 20CrMnTiH with a hardness of 60HRC. The depth of cut was ap 0.12mm, the feed rate was f 0.06mm / r, and the linear speed was 160m / min. In related technologies, cubic boron nitride inserts and cutting tools welded to carbide tool bodies could machine 180 workpieces per cutting edge, but chipping occurred at the tool tip. The cutting tool 1 of this utility model can achieve machining 230 workpieces per cutting edge, and the tool life (anti-chipping performance) is improved by 27.8%.

[0058] Other configurations and operations of the cutting tool 1 according to the embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A cutting tool, characterized in that, include: A blade comprising an intermediate layer and two cubic boron nitride layers, the intermediate layer being located between the two cubic boron nitride layers; The blade body has an intermediate layer welded to it. One of the welding surfaces of the blade body and the blade is provided with a tenon, and the other is provided with a mortise. The tenon fits into the mortise.

2. The cutting tool according to claim 1, characterized in that, The mortise includes at least two mating planes, and the included angle between the two mating planes is 50-130 degrees.

3. The cutting tool according to claim 2, characterized in that, The mortise also includes a rounded corner surface connecting the two mating planes, the radius of which is greater than or equal to 0.2 mm.

4. The cutting tool according to claim 1, characterized in that, The blade is cut from a composite sheet material, which includes an intermediate layer and two cubic boron nitride layers, with the intermediate layer located between the two cubic boron nitride layers.

5. The cutting tool according to claim 4, characterized in that, The blade is formed by laser cutting or wire cutting of the composite sheet material.

6. The cutting tool according to claim 1, characterized in that, The cubic boron nitride layer is sintered on the intermediate layer.

7. The cutting tool according to claim 1, characterized in that, The thickness of the cubic boron nitride layer is 0.5-1.5 mm.

8. The cutting tool according to claim 1, characterized in that, There are multiple tenons and multiple mortises, and the multiple tenons are respectively fitted into the multiple mortises.

9. The cutting tool according to claim 1, characterized in that, The welding temperature between the blade and the blade body is 750-850℃.

10. The cutting tool according to claim 1, characterized in that, The cubic boron nitride layer has a particle size of 1-50 micrometers, and both the intermediate layer and the blade body are made of cemented carbide.

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