Turning inserts for difficult-to-machine materials

Abstract

The invention relates to the technical field of tool design, and discloses a turning blade suitable for machining difficult-to-machine materials, comprising a blade body with a polygonal structure, comprising an upper surface, a lower surface and a plurality of side surfaces, any two adjacent side surfaces are transitioned by an arc surface at the intersection, the arc surface intersects with the upper surface / lower surface to form an arc cutting edge, and the side surface intersects with the upper surface / lower surface to form a main cutting edge; the upper surface comprises a supporting surface radiating from a positioning center hole of the blade body to an edge of the blade body, a top first rake face, a top second rake face, a top chip guiding protrusion and a top chip blocking face are arranged in sequence between the arc cutting edge and the supporting surface, a side first rake face, a side second rake face, a groove bottom face and a side chip blocking face are arranged in sequence between the main cutting edge and the supporting surface, and a plurality of side chip guiding protrusions arranged at intervals are arranged in sequence on the groove bottom face from the arc cutting edge toward the main cutting edge; the structure of the lower surface is the same as that of the upper surface.

Description

Technical Field

[0001] The invention relates to the technical field of tool design, and in particular to a turning insert suitable for machining difficult-to-machine materials. Background Art

[0002] In the manufacturing of automobile, aerospace, large power station and ship industries, high temperature alloy, titanium alloy, heat-resistant stainless steel and other materials can withstand complex stress and can be used at high temperature in a very harsh environment, so these materials are widely used, but these materials are recognized as difficult to process materials in the industry. When being processed, there are various problems such as large cutting force of the tool, high cutting heat, low thermal conductivity, large tendency of work hardening of the workpiece material, fast tool wear and short tool life, easy to produce built-up edge, poor workpiece surface quality, etc., which makes the processing efficiency low and the processing cost high. Therefore, how to optimize the geometric parameters of carbide tools and their chip breakers, and design tools that can meet the processing requirements of the above-mentioned difficult-to-process materials, is a problem that needs to be solved urgently.

[0003] Chinese patent CN201821054190.5 discloses a cutting blade with a larger turning tool rake angle, a wider chip groove, and a gently angled chip reel. The blade has "low cutting resistance, low cutting temperature, and small tool bonding wear. It can be processed under normal pressure cooling and does not require high-pressure cooling to enhance the cooling effect." However, it has been verified in practice that it is difficult for this blade to obtain a good chip processing effect under small parameters; and because it uses normal pressure cooling, the cutting fluid is not easy to enter the top of the tool tip when the parameters are large, and the cutting area of ​​the blade cannot be cooled in a timely and sufficient manner, which will eventually cause the blade temperature to rise and affect the cutting life.

[0004] Chinese patent CN201911024526.2 discloses a blade with wedge-shaped chip breaking parts, protrusions, and chip breaking bumps designed near the blade tip and cutting edge. These technical features can improve the chip curling and chip removal effects under turning finishing and semi-finishing conditions, and can meet the turning processing requirements of high-temperature alloys to a certain extent. However, the blade is prone to excessive chip breaking in semi-finishing with large parameters, thereby generating greater cutting resistance and cutting temperature, which greatly reduces the service life of the blade. Summary of the invention

[0005] The technical problem solved by the present invention is to overcome the defects of the prior art and provide a turning insert with excellent cutting performance suitable for machining difficult-to-machine materials.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A turning blade suitable for machining difficult-to-machine materials, comprising a blade body with a polygonal structure, the blade body comprising an upper surface, a lower surface and a plurality of side surfaces, any two adjacent side surfaces are transitioned by an arc surface at the intersection, the arc surface intersects with the upper surface / lower surface to form an arc cutting edge, and the side surface intersects with the upper surface / lower surface to form a main cutting edge;

[0008] The upper surface includes a support surface radiating from the positioning center hole of the blade body to the edge of the blade body, a top first rake face, a top second rake face, a top chip guiding protrusion and a top chip blocking face arranged in sequence between the arc cutting edge and the support surface, a side first rake face, a side second rake face, a groove bottom face and a side chip blocking face arranged in sequence between the main cutting edge and the support surface, and a plurality of side chip guiding protrusions arranged at intervals are arranged in sequence on the groove bottom face from the arc cutting edge toward the main cutting edge;

[0009] The lower surface structure is the same as the upper surface structure.

[0010] Furthermore, the side chip stop surface includes a first side chip stop surface close to the supporting surface and a second side chip stop surface away from the supporting surface. The first side chip stop surface and the second side chip stop surface are embedded and separated by a coolant guide surface extending from close to the arc cutting edge toward the supporting surface, and the coolant guide surface gradually moves away from the bottom surface of the groove during the extension process.

[0011] Furthermore, the bottom surface of the groove is inclined downward along the height direction of the blade body when extending from the arc cutting edge toward the main cutting edge.

[0012] Furthermore, the vertical distance h1 between the ridge line of the side chip guiding protrusion and the arc cutting edge in the height direction of the insert body increases successively.

[0013] Furthermore, a vertical distance h2 from a ridge line of the side chip guiding protrusion to a bottom surface of an adjacent groove is greater than or equal to 0.03 mm.

[0014] Furthermore, a vertical distance H between the highest point of the groove bottom surface and the arc cutting edge in the height direction of the blade body is 0.1 to 0.5 mm.

[0015] Furthermore, a first rake angle α formed by the top first rake surface and the support surface is 6° to 20°, and a second rake angle β formed by the top second rake surface and the support surface is 10° to 25°.

[0016] Furthermore, the main cutting edge is composed of a first main cutting edge close to the circular arc cutting edge and a second main cutting edge away from the circular arc cutting edge. The first rake angle value formed by the side first rake face and the support surface at the first main cutting edge is equal to the first rake angle α value formed by the top first rake face and the support surface. The second rake angle value formed by the second rake face and the support surface at the first main cutting edge is equal to the second rake angle β value formed by the top second rake face and the support surface. The length S of the first main cutting edge is greater than or equal to 0.2 mm, and S is less than or equal to 1 / 2 of the length of the main cutting edge.

[0017] Furthermore, a first rake angle γ formed by the side first rake face and the support surface at the second main cutting edge is 3°~15°, and γ≦α, and a second rake angle θ formed by the side second rake face and the support surface at the second main cutting edge is 10°~20°, and θ≦β.

[0018] Furthermore, the horizontal width of the arc cutting edge is L1, the horizontal width of the main cutting edge is L2, and L1 and L2 satisfy 0.06 mm≦L1≦L2≦0.5 mm.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) By designing the top chip guide protrusion and the side chip guide protrusion, combined with the groove bottom design, the turning insert is guaranteed to have sufficient chip space, and the chips can be guided to flow, curl and break smoothly and be discharged to the unprocessed surface, thereby reducing the chip contact area and thus reducing the heat transferred from the chips to the turning insert;

[0021] 2) The combination of the top chip guide protrusion, the top chip stop surface and the side chip stop surface enables the chips to be smoothly guided, curled and broken by the top chip guide protrusion under small cutting parameters; under larger cutting parameters, the chips can smoothly flow through the top chip guide protrusion, and finally curl and break under the action of the top chip stop surface and the side chip stop surface; the blade has a wide chip processing range under the condition of controllable cutting force and cutting temperature, which can meet the chip breaking requirements of finishing and semi-finishing at the same time, and can also ensure the long-term stable use of the blade and improve the tool life;

[0022] 3) Designing a coolant guide surface at the side chip stop surface allows the coolant to better enter the top of the tool tip and the bottom of the groove, so that the insert can be fully and timely cooled under normal pressure cooling conditions. At the same time, the coolant guide surface is equivalent to increasing the chip space, which can also help reduce the cutting force and lower the cutting temperature;

[0023] 4) All first rake angles are sharp rake angles, which on the one hand reduce the cutting resistance at each cutting edge, reduce work hardening and reduce cutting temperature; on the other hand, improve the strength of the main cutting edge, improve the groove wear resistance and chip impact resistance, and ensure the safety of the turning inserts under complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the three-dimensional structure of the turning insert suitable for machining difficult-to-machine materials described in Example 1;

[0025] Figure 2 A front view of the turning insert suitable for machining difficult-to-machine materials described in Example 1;

[0026] Figure 3 A side view of the turning insert suitable for machining difficult-to-machine materials described in Example 1;

[0027] Figure 4 for Figure 2 Enlarged view of part A;

[0028] Figure 5 for Figure 4 Middle GG section;

[0029] Figure 6 for Figure 4 Middle JJ section;

[0030] Figure 7 for Figure 4 Middle KK cross-section. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with specific implementation methods, wherein the accompanying drawings are only used for exemplary descriptions and represent only schematic diagrams rather than actual drawings, and should not be understood as limitations on this patent; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted.

[0032] Example 1

[0033] Provide a Figure 1 The turning insert shown is suitable for turning difficult-to-machine materials such as high-temperature alloys, titanium alloys, and heat-resistant stainless steels. It includes a polygonal blade body, combined with Figure 2 and Figure 3As shown, the blade body includes an upper surface 1, a lower surface 2 and multiple side surfaces 3, any two adjacent side surfaces 3 are transitioned by an arc surface 4 at the intersection, the arc surface 4 intersects with the upper surface 1 / lower surface 2 to form an arc cutting edge 51, the side surface 3 intersects with the upper surface 1 / lower surface 2 to form a main cutting edge 52, and the main cutting edge is composed of a first main cutting edge 521 close to the arc cutting edge 51 and a second main cutting edge 522 away from the arc cutting edge 51; a positioning center hole 6 is provided on the blade body at its geometric center, and the blade body is symmetrical about the neutral plane MP, so the lower surface structure is exactly the same as the upper surface structure.

[0034] Specifically, Figure 4 As shown, the upper surface 1 includes a support surface 11 parallel to the neutral plane MP radiating from the positioning center hole 6 of the blade body to the edge of the blade body, and a top first rake face 71, a top second rake face 72, a top chip guiding protrusion 73 and a top chip blocking surface 74 are arranged in sequence between the arc cutting edge 51 and the support surface 11, and a side first rake face 81, a side second rake face 82, a groove bottom surface 83 and a side chip blocking surface 84 are arranged in sequence between the main cutting edge 52 and the support surface 11, and a plurality of side chip guiding protrusions 85 arranged at intervals are arranged in sequence on the groove bottom surface 83 from the arc cutting edge toward the main cutting edge, and the convex ridge lines of the top chip guiding protrusion 73 and the side chip guiding protrusion 85 are arc-shaped arches relative to the groove bottom surface 83. Specifically, as shown in FIG. Figure 5 As shown, the vertical distance h1 between the ridge line of the side chip guiding protrusion and the arc cutting edge in the height direction of the blade body increases successively (the figure shows h1 between the top of the ridge line and the arc cutting edge), wherein the top chip guiding protrusion 73 and the top second front cutting edge 72 and the top chip blocking surface 74 are smoothly transitioned, and the side chip guiding protrusion 85 and the groove bottom surface 83 are smoothly transitioned.

[0035] The combination of the above-mentioned top chip guide protrusion, side chip guide protrusion and groove bottom surface ensures that the turning insert has sufficient chip holding space. In addition, the groove bottom surface 83 is inclined downward along the height direction of the insert body when extending from the arc cutting edge toward the main cutting edge. This design can further guide the chips to flow, curl and break smoothly, and discharge them to the unmachined surface, so as to reduce the chip contact area and thereby reduce the heat transferred from the chips to the turning insert.

[0036] Under small cutting parameters, the top chip guide protrusion, top chip stop surface and side chip stop surface of the turning tool can enable the chips to be smoothly guided, curled and broken by the top chip guide protrusion; under larger cutting parameters, the chips will flow smoothly through the top chip guide protrusion, and finally curled and broken under the action of the top chip stop surface and the side chip stop surface.

[0037] The turning tool of this embodiment has a wide chip processing range under the condition that the cutting force and cutting temperature are controllable, and can simultaneously meet the chip breaking requirements of finishing and semi-finishing, while ensuring the long-term and stable use of the blade and improving the tool life.

[0038] In order to allow the coolant to smoothly enter the top of the tool tip (i.e., near the arc cutting edge) and the groove bottom surface 83 during the machining process of the turning tool, the side chip stop surface can be designed. Specifically, the side chip stop surface 84 includes a first side chip stop surface 841 close to the support surface and a second side chip stop surface 842 away from the support surface, wherein the first side chip stop surface and the second side chip stop surface are embedded and separated by a coolant guide surface 86 extending from the arc cutting edge toward the support surface, and the coolant guide surface gradually moves away from the groove bottom surface during the extension process. During machining, the coolant flows along the coolant guide surface 86 to the tool tip and the groove bottom surface 83, and the turning blade can be fully and timely cooled under normal pressure cooling conditions. In addition, the coolant guide surface is equivalent to increasing the chip holding space, which can help reduce the cutting force of the turning blade and reduce the cutting temperature.

[0039] In order to ensure the chip breaking and chip drainage effect during the machining process, Figure 5 As shown, the vertical distance h2 from the ridge line of the side chip guiding protrusion 85 to the adjacent groove bottom surface 83 needs to be greater than or equal to 0.03mm (the figure shows the vertical distance h2 from the top of the ridge line of the side chip guiding protrusion to the adjacent groove bottom surface), and the vertical distance H between the highest point of the groove bottom surface 83 and the arc cutting edge 51 in the height direction of the blade body is between 0.1 and 0.5mm. In this embodiment, H is 0.3mm.

[0040] In the turning insert of the present embodiment, the first rake angle α formed by the top first rake face 71 and the support surface 11 is 6° to 20°, and the second rake angle β formed by the top second rake face 72 and the support surface 11 is 10° to 25°. Preferably, at the acute vertex angle of the insert body, α=15°, and at the obtuse vertex angle of the insert body, α=10°, and β is 20°; the first rake angle value formed by the side first rake face and the support surface 11 at the first main cutting edge 521 is equal to the first rake angle α value formed by the top first rake face and the support surface, the second rake angle value formed by the second rake face at the first main cutting edge 521 and the support surface 11 is equal to the second rake angle β value formed by the top second rake face and the support surface, the length S of the first main cutting edge 521 is greater than or equal to 0.2mm, and S is less than or equal to 1 / 2 of the length of the main cutting edge. In the present embodiment, S=1.5mm at the acute vertex angle of the insert body, and S=4.5mm at the obtuse vertex angle of the insert body. ; A first rake angle γ formed by the first rake face of the side portion at the second main cutting edge 522 and the support surface 11 is 3° to 15°, and γ≦α, a second rake angle θ formed by the second rake face of the side portion at the second main cutting edge 522 and the support surface 11 is 10° to 20°, and θ≦β, preferably, γ is 10°, and θ is 20°; the horizontal width of the arc cutting edge 51 is L1, the horizontal width of the main cutting edge 52 is L2, and L1 and L2 satisfy 0.06mm≦L 1≦L2≦0.5mm, in this embodiment, L1=L2=0.3mm, the above parameters are carefully designed, sharp rake angles are adopted at the front section of the arc chip cutting edge and the main cutting edge, and a relatively sharp rake angle is adopted at the rear section of the main cutting edge. On the one hand, the cutting resistance at each cutting edge is reduced, the work hardening and the cutting temperature are reduced, and on the other hand, the strength of the main cutting edge is improved, the groove wear resistance and the chip impact resistance are improved, and the safety of the turning insert under complex working conditions is ensured.

[0041] The turning insert of the present application has good adaptability in sharpness and strength of each cutting edge, which gives the turning insert good chip impact resistance and low cutting resistance, excellent chip breaking and chip removal performance, and can simultaneously meet the finishing and semi-finishing turning needs of various difficult-to-process materials such as high-temperature alloys, titanium alloys, heat-resistant stainless steel, etc. It has good versatility and can be vigorously promoted for use.

[0042] Obviously, the above embodiments are merely examples for clearly illustrating the technical solutions of the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A turning insert suitable for machining difficult-to-machine materials, characterized in that: The blade body is a polygonal structure, the blade body includes an upper surface, a lower surface and a plurality of side surfaces, any two adjacent side surfaces are transitioned by an arc surface at the intersection, the arc surface intersects with the upper surface / lower surface to form an arc cutting edge, and the side surface intersects with the upper surface / lower surface to form a main cutting edge; The upper surface includes a support surface radiating from the positioning center hole of the blade body to the edge of the blade body, a top first rake face, a top second rake face, a top chip guiding protrusion and a top chip blocking face arranged in sequence between the arc cutting edge and the support surface, a side first rake face, a side second rake face, a groove bottom face and a side chip blocking face arranged in sequence between the main cutting edge and the support surface, a plurality of side chip guiding protrusions arranged at intervals are arranged in sequence on the groove bottom face from the arc cutting edge toward the main cutting edge, the groove bottom face is inclined downward along the height direction of the blade body when extending from the arc cutting edge toward the main cutting edge, and the vertical distance h1 between the convex ridge line of the side chip guiding protrusion and the arc cutting edge in the height direction of the blade body increases in sequence; The side chip stop surface comprises a first side chip stop surface close to the support surface and a second side chip stop surface away from the support surface, the first side chip stop surface and the second side chip stop surface are embedded and separated by a coolant guide surface extending from a position close to the arc cutting edge toward the support surface, and the coolant guide surface gradually moves away from the groove bottom surface during the extension process; The lower surface structure is the same as the upper surface structure.

2. The turning insert suitable for machining difficult-to-machine materials according to claim 1, characterized in that: A vertical distance h2 from a ridge line of the side chip guiding protrusion to a bottom surface of an adjacent groove is greater than or equal to 0.03 mm.

3. The turning insert suitable for machining difficult-to-machine materials according to claim 1 or 2, characterized in that: The vertical distance H between the highest point of the groove bottom surface and the arc cutting edge in the height direction of the blade body is 0.1 to 0.5 mm.

4. The turning insert suitable for machining difficult-to-machine materials according to claim 3, characterized in that: A first rake angle α formed by the top first rake face and the support surface is 6° to 20°, and a second rake angle β formed by the top second rake face and the support surface is 10° to 25°.

5. The turning insert suitable for machining difficult-to-machine materials according to claim 4, characterized in that: The main cutting edge is composed of a first main cutting edge close to the circular arc cutting edge and a second main cutting edge away from the circular arc cutting edge. The first rake angle value formed by the side first rake face and the support surface at the first main cutting edge is equal to the first rake angle α value formed by the top first rake face and the support surface. The second rake angle value formed by the second rake face and the support surface at the first main cutting edge is equal to the second rake angle β value formed by the top second rake face and the support surface. The length S of the first main cutting edge is greater than or equal to 0.2 mm, and S is less than or equal to 1 / 2 of the length of the main cutting edge.

6. The turning insert suitable for machining difficult-to-machine materials according to claim 5, characterized in that: A first rake angle γ formed by the side first rake face and the support surface at the second main cutting edge is 3° to 15°, and γ≦α, and a second rake angle θ formed by the side second rake face and the support surface at the second main cutting edge is 10° to 20°, and θ≦β.

7. The turning insert suitable for machining difficult-to-machine materials according to claim 6, characterized in that: The horizontal width of the arc cutting edge is L1, and the horizontal width of the main cutting edge is L2, and L1 and L2 satisfy 0.06mm≦L1≦L2≦0.5mm.

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