Triangular metal ceramic turning insert

Abstract

The application discloses a triangular metal ceramic blade for turning processing, which mainly comprises a triangular blade body, symmetric surfaces, a stepped positioning hole in the center of the blade, a rake face with a variable rake angle, side faces with a 0-degree relief angle, main cutting edges with a polishing function formed between two adjacent side faces, inverted edge structures of the main cutting edges and the secondary cutting edges, a gradually increased width and depth of a chip breaker groove in a direction away from a blade tip, an angle of a chip breaker face connected with the groove bottom which increases in a direction close to the blade tip, a pair of semispherical convex parts of the chip breaker groove of the blade tip part which are symmetric to a diagonal line, an elliptical concave part arranged in the groove bottom of the secondary cutting edge part, a support face connected with the chip breaker face, which has a symmetric wavy groove, a boss with the same height as the support face arranged between adjacent chip breaker faces, and a hexagonal vertical concave part in the middle of the boss. The application can effectively improve the chip breaking effect, prevent chip winding, improve the surface smoothness of the processed surface, and reduce the cutting temperature.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metal cutting, and relates to a triangular metal ceramic turning blade made of metal ceramic as a material and capable of better chip breaking and exhibiting good cutting performance and tool life in a semi-finishing cutting process. BACKGROUND

[0002] Providing a chip breaking groove on the rake face of a tool is an effective way to control the shape and flow direction of a chip.

[0003] With the progress and development of the times, the type of tool chip breaking groove has been continuously improved. The blade groove structure has gradually developed from the initial crescent depression chip breaking groove stage to the two-dimensional chip breaking groove stage, and to the current three-dimensional chip breaking groove stage. With the support of powder metallurgy technology and tool indexable technology, the structure and function of the tool chip breaking groove have become diversified and complex. Structures such as small bosses, recessed pits and curved grooves appear in the groove structure, so that the blade has a wider chip breaking range, can be used for machining various metal materials, has smaller cutting resistance, can realize large cutting and high-speed cutting, and higher surface machining quality can be obtained under the same cutting parameters.

[0004] In terms of tool materials, the hard alloy still occupies the largest market share so far, and the metal ceramic tool is a new type of tool material that has developed slowly in recent years. Metal ceramic refers only to metal ceramic materials with Ti(C, N) as the main ceramic phase and Ni and Co as the metal binder phase. It has the characteristics of both metal and ceramic materials, can replace rare tungsten resources, and is more affordable than traditional WC-Co hard alloy. Compared with the traditional WC-Co hard alloy, it has certain toughness, plasticity, high hardness, high temperature resistance, wear resistance, high efficiency and other excellent properties. These properties make Ti(C, N)-based metal ceramic more suitable for high-speed cutting and finishing and semi-finishing of materials. However, there is still less research on the design and research of the groove type based on the chip breaking and cutting performance of the metal ceramic tool, and most of them are about hard alloy tools. The cutting rules of hard alloy tools are not completely applicable to metal ceramic tools, so it is urgent to design the geometric groove parameters of metal ceramic tools to solve the problems of chip winding and tool wear in the cutting of metal ceramic tools. SUMMARY

[0005] The purpose of the present application is to provide a triangular metal ceramic turning blade with an improved blade groove structure to solve the problems of tool nose wear and chip winding that cannot be broken in semi-finishing machining of metal ceramic tools, and to improve the surface finish of the workpiece to a certain extent.

[0006] The technical scheme adopted by the present application is: a triangular metal ceramic turning blade, the turning blade has a blade body, a supporting surface, a stepped positioning circular hole formed in the center of the blade, a rake face, a relief face, a nose, a chip breaker groove bottom surface, a chip breaker surface, a hemispherical convex part, an elliptical concave part, a wave-shaped symmetrical groove, a boss,

[0007] The upper and lower surfaces of the blade body are symmetrically arranged, the relief face is located on the circumferential side surface of the blade body, the nose is arranged along the top corner edge of the upper and lower surfaces of the blade body, the rake face is located inside the nose and extends downward along the surface of the blade body to form a closed continuous surface, the chip breaker groove bottom surface extends horizontally from the rake face to the inside of the blade, the hemispherical convex part and the elliptical concave part are located between the chip breaker groove bottom surface and the chip breaker surface, the chip breaker surface extends upward from the hemispherical convex part and the elliptical concave part to the inside of the blade, the hemispherical convex part is arranged in a pair on both sides of the diagonal line of the blade, the elliptical concave part is arranged between the hemispherical convex parts of the two top corners, the supporting surface is arranged on the upper and lower surfaces of the blade body and is respectively the highest and lowest position of the upper and lower surfaces of the entire blade body, the wave-shaped symmetrical groove is arranged on the supporting surface, the boss is arranged between adjacent chip breaker surfaces, the outer profile of the boss is rounded, the outer top surface of the boss is at the same height as the supporting surface, the middle part of the boss is vertically recessed in a hexagonal shape, and the bottom surface of the recessed part of the boss is higher than the chip breaker groove bottom surface.

[0008] The rake face includes a first rake face and a second rake face, the first rake face and the second rake face are inclined inward and downward and form two different angles with the horizontal plane, the first rake angle γ1 and the second rake angle γ2, the relief face is consistent on the three side surfaces of the blade, and the normal relief angle is 0°, the nose includes a main cutting edge composed of a straight line segment and a circular arc segment, a secondary cutting edge extending away from the center of the nose, an inverted edge inclined downward and outward, and a land extending between the main cutting edge and the secondary cutting edge, the two different angles formed by the rake face and the horizontal plane gradually decrease in the direction of the secondary cutting edge, the chip breaker groove bottom surface is connected with the second rake face and the chip breaker surface, and the width of the chip breaker groove bottom surface gradually increases in the extension direction of the secondary cutting edge, and the angle θ formed by the chip breaker surface and the horizontal plane gradually increases in the direction of the main cutting edge.

[0009] Further, the boss is provided with a smooth transition connection arc surface between the chip breaker groove bottom surface and the chip breaker surface.

[0010] Further, the entire material of the turning blade is prepared from Ti(C, N) based metal ceramic.

[0011] Further, the inverted edge angle α is a negative angle of 10°.

[0012] Further, the width of the land band gradually increases by 0.15mm-0.3mm along the extension direction of the secondary cutting edge.

[0013] Further, the first rake angle γ1 gradually changes by 11°-15° from the secondary cutting edge to the primary cutting edge, and the second rake angle γ2 gradually changes by 14°-18° from the secondary cutting edge to the primary cutting edge.

[0014] Further, the height of the land band to the bottom surface of the chip breaker groove gradually increases by 0.15mm-0.3mm along the extension direction of the secondary cutting edge.

[0015] Further, the angle θ gradually changes by 30°-35° from the secondary cutting edge to the primary cutting edge.

[0016] Further, the distance of the land band to the support surface gradually changes by 0.1mm-0.2mm.

[0017] Further, the height of the pair of semispherical convexes is higher than the height of the land band, and the distance between the pair of semispherical convexes is between 0.2mm-0.3mm.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] (1) The cutting edge of the tip part is in the form of a modified straight line and curve, which can improve the smoothness of the workpiece surface and meet the requirements of high-precision workpiece surface;

[0020] (2) The design of variable groove width and depth, variable rake angle, variable land band width, and variable chip clearance angle can meet a larger range of chips and improve the stress at the curved part of the chip, thereby improving the chip breaking effect;

[0021] (3) The inverted land and the boss can strengthen the structural strength of the cutting edge and the whole tool, effectively reducing the probability of tool chipping and breaking, and improving the durability of the tool.

[0022] (4) The semispherical convexes in the chip breaker groove can extrude the chip under small cutting amount, control the bending and breaking of the chip, and effectively avoid the adverse effects of chip winding.

[0023] In addition to the purposes, features and advantages described above, the present application has other purposes, features and advantages. The present application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a three-dimensional structural schematic view of a triangular metal ceramic turning insert according to the present application;

[0025] Figure 2 is a front view of a triangular metal ceramic turning insert according to the present application;

[0026] Figure 3 is a cross-sectional view taken along Figure 2 A-A line;

[0027] Figure 4 is a left view of a triangular metal ceramic turning insert according to the present application;

[0028] Figure 5 is a top view of a triangular metal ceramic turning insert according to the present application;

[0029] Figure 6 is an enlarged view of a nose of a triangular metal ceramic turning insert according to the present application;

[0030] Figure 7 is a cross-sectional view taken along Figure 6 B-B line;

[0031] Figure 8 is a cross-sectional view taken along Figure 6 A-A line. DETAILED DESCRIPTION

[0032] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] FIGS. 1 and 2 are a three-dimensional structural schematic view and a front view of a turning insert according to the present application, FIG. 1 and Figure 2 show a turning insert capable of stable chip breaking and having a good cutting performance.

[0034] As shown in FIG. 1, the turning insert 1 has an equilateral triangular shape, and the features corresponding to the three sides and the features of the upper and lower faces are symmetrically consistent. Figures 1 to 5 The present application is a triangular metal ceramic turning insert having an insert body 1, a support face 2, a stepped positioning circular hole 3 formed at the center of the insert, a rake face 4, a relief face 5, a nose 6, a chip breaker groove bottom face 7, a chip breaker face 8, a semispherical convex portion 9, an elliptical concave portion 10, a wave-shaped symmetric groove 11, a boss 12,

[0035]

[0036] ​The upper and lower surfaces of the blade body 1 are symmetrically arranged. The flank face 5 is located on the circumferential side of the blade body 1. The tip 6 is arranged along the apex edge of the upper and lower surfaces of the blade body 1. The rake face 4 is located inside the tip 6 and extends downwards along the surface of the blade body 1 to form a closed continuous surface. The bottom surface 7 of the chip breaker groove extends horizontally from the rake face 4 into the blade. The hemispherical protrusion 9 and the elliptical recess 10 are located between the bottom surface 7 of the chip breaker groove and the anti-chip surface 8. The anti-chip surface 8 extends upwards from the hemispherical protrusion 9 and the elliptical recess 10 into the blade. The hemispherical protrusion 9 is located between the hemispherical protrusion 9 and the elliptical recess 10. The blade is arranged in pairs on both sides of the diagonal. The elliptical recess 10 is located between the hemispherical protrusions 9 at the two apex corners. The support surface 2 is located on the upper and lower surfaces of the blade body 1, respectively at the highest and lowest positions of the upper and lower surfaces of the entire blade body 1. The support surface 2 is provided with the wave-shaped symmetrical groove 11. The boss 12 is provided between adjacent chip-breaking surfaces 8. The outer contour of the boss 12 is blunt and rounded. The outer top surface of the boss 12 is at the same height as the support surface 2. The middle part of the boss 12 is vertically recessed in a hexagon. The bottom surface of the recessed part of the boss 12 is higher than the bottom surface 7 of the chip-breaking groove.

[0037] The rake face 4 includes a first rake face 41 and a second rake face 42. The first rake face 41 and the second rake face 42 are inclined inward and downward and form two different angles with the horizontal plane, a first rake angle γ1 and a second rake angle γ2. The first rake face 41 and the second rake face 42 are consistent on the three sides of the blade, and their normal clearance angle is 0°. The blade tip 6 includes a main cutting edge 61 composed of a straight segment and an arc segment, a secondary cutting edge 62 extending away from the center of the blade tip, a chamfer 63 inclined downward and outward, and a chamfer located at... The rib 64 extending between the main cutting edge 61 and the secondary cutting edge 62, the rake face 4 forms two different angles with the horizontal plane, both of which gradually decrease towards the secondary cutting edge 62, the bottom surface 7 of the chip breaker groove is connected to the second rake face 42 and the anti-chip surface 8, and its width gradually increases along the extension direction of the secondary cutting edge 62, the angle θ formed by the anti-chip surface 8 and the horizontal plane gradually increases towards the main cutting edge 61, and the boss 12 is provided with a smoothly transitioning arc surface 13 between the bottom surface 7 of the chip breaker groove and the anti-chip surface 8.

[0038] What's special about this turning insert is that its entire material is made of cermet.

[0039] like Figure 6 The image shown is an enlarged view of the tip of the triangular metal-ceramic turning insert of the present invention. More preferably, the main cutting edge 61 is composed of two consistent straight line segments, two circular arc segments with consistent radii of curvature, and a middle circular arc segment with a larger radius of curvature.

[0040] like Figure 7 As shown, it is along Figure 6Fig. 3 is a cross-sectional view taken along the line B-B, sequentially forming the chamfer 63, the land 64, the first rake face 41, the second rake face 42, the bottom face 7 of the chip breaker, the clearance face 8, and the support face 2 in the direction from the part of the main cutting edge 61 of the nose 6 to the center of the insert.

[0041] The angle a of the chamfer 63 is kept at a negative angle of 10° in all cutting edges.

[0042] The land 64 gradually increases in width in the outward direction of the nose 6 at a rate of 0.15 mm -> 0.3 mm.

[0043] The first rake angle γ1 gradually changes from the minor cutting edge 62 to the main cutting edge 61 at a rate of 11°-15°, and the second rake angle γ2 gradually changes from the minor cutting edge 62 to the main cutting edge 61 at a rate of 14°-18°.

[0044] The height of the bottom face 7 of the chip breaker to the land 64 is the flute depth 1, which gradually increases in the direction of the minor cutting edge 62 at a rate of 0.15 mm-0.3 mm.

[0045] The angle θ gradually changes from the minor cutting edge 62 to the main cutting edge 61 at a rate of 30°-35°.

[0046] The distance of the land to the support face is preferably the edge height h, which gradually changes at a rate of 0.1 mm-0.2 mm.

[0047] As shown in Fig. 4, which is a cross-sectional view taken along the line A-A, sequentially forming the chamfer 63, the land 64, the first rake face 41, the second rake face 42, the bottom face 7 of the chip breaker, the hemispherical protrusion 9, the clearance face 8, and the support face 2 in the direction from the part of the main cutting edge 61 of the nose to the center of the insert, and more preferably the height of the hemispherical protrusion is higher than the height of the land, and the distance between the pair of protrusions is between 0.2 mm-0.3 mm. Figure 8 Figure 6 The main cutting edge 61 and the minor cutting edge 62 are parallel to the support face 2.

[0048] The relevant functional principles of the turning insert as described above are explained as follows.

[0049] The larger the rake angle, the sharper the insert, and at the same time, the strength of the insert is reduced, the friction between the machined metal and the rake face is reduced, the deformation coefficient value is reduced, the friction and normal stress between the chip and the insert are also reduced accordingly, and thus the cutting force is reduced. By changing the first rake angle γ1 and the second rake angle γ2, the machining with a smaller rake angle and cutting force is performed for higher precision when the cutting depth is small, and the machining with a larger rake angle and cutting force is performed for lower precision, thereby satisfying a wider range of cutting and chip breaking machining.

[0050] The larger the rake angle, the sharper the insert, and at the same time, the strength of the insert is reduced, the friction between the machined metal and the rake face is reduced, the deformation coefficient value is reduced, the friction and normal stress between the chip and the insert are also reduced accordingly, and thus the cutting force is reduced. By changing the first rake angle γ1 and the second rake angle γ2, the machining with a smaller rake angle and cutting force is performed for higher precision when the cutting depth is small, and the machining with a larger rake angle and cutting force is performed for lower precision, thereby satisfying a wider range of cutting and chip breaking machining.

[0051] ​The chamfer 63 set on the cutting edge can enhance the strength of the cutting edge and the nose, thereby improving the tool durability.

[0052] On the other hand, the width of the land 64 adjacent to the chamfer 63 is presented in different widths for different cutting depths to meet the machining in each precision range, to ensure the accurate control of the chip flow and to ensure the tool strength. Similar to the width of the land 64, the width s of the groove (i.e. the width of the first rake face 41 to the anti-chip face 8) is smaller at the nose 6 to accommodate the low machining precision, allowing the thinner chip to break with a large radius of curvature, and vice versa, it is larger at the secondary cutting edge 62 to accommodate the high machining precision, allowing the thicker chip to break with a small curvature. The groove depth l is smaller at the nose 6 and gradually increases along the direction of the secondary cutting edge 62. In this structure, the shear stress is quickly generated on the chip generated under small cutting depth, so that the chip is more easily controlled and broken at the main cutting edge part 61, while the shear stress is differentially distributed on the entire length of the chip generated under high cutting depth, so that the chip can be smoothly curled.

[0053] The anti-chip face 8 is upwardly inclined after the chip-breaking groove bottom face 7, and appropriate increase of the anti-chip angle θ is conducive to improving the chip-breaking range and chip capacity of the insert. The nose 6 part produces a lower thickness of chip due to lower cutting depth, so its breaking requires a larger curvature. The presence of the anti-chip face 8 allows the chip to contact the anti-chip face 8 after flowing through the chip-breaking groove bottom face 7 and then curl and break.

[0054] The pair of symmetrical hemispherical protrusions 9 of the nose 6 part at the chip-breaking groove bottom face 7 and the bottom of the anti-chip face 8. Its role is to guide the extruded chip to curl when the chip cannot contact the chip-breaking groove bottom face 7 through the hemispherical protrusion 8, and the spherical surface makes the chip not generate too much friction when it rubs against it, thereby reducing the degree of tool wear. More preferably, the pair of hemispherical protrusions 9 are 0.2-0.3 mm apart, and the height is higher than the height of the land 64 and less than the height of the support face 2, providing enough space for the chip to flow, while the spherical surface maximizes the surface area to achieve the purpose of heat dissipation.

[0055] The main cutting edge 61 is a straight line and a circular arc line composed of a finishing edge. During the feed process of the insert, the relief face 5 performs finishing on the machined surface, thereby improving the machining surface precision.

[0056] On the other hand, the elliptical recess 10 at 12 set on the chip-breaking groove bottom face 7 of the secondary cutting edge 62 part is equivalent to the structure of a friction-reducing groove. Large cutting depth often brings large cutting force and high cutting temperature, so the elliptical recess 10 reduces the contact area between the chip and the tool, thereby reducing the cutting resistance, achieving the effect of reducing the cutting force and the cutting temperature.

[0057] The wave-like symmetrical recess 11 and the vertical recess in the middle of the boss 12 on the supporting surface 2 increase the surface area, reduce the weight of the blade and facilitate heat dissipation. In particular, the boss 12 can enhance the overall strength of the blade.

[0058] The above description is merely preferred embodiments of the present application, but not for limiting the present application. For the skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A triangular cermet turning insert, the turning insert having an insert body (1), a support surface (2), a stepped positioning hole (3) formed in the center of the insert, a rake surface (4), a relief surface (5), a nose (6), a chip breaker bottom surface (7), a chip breaker surface (8), a hemispherical convex part (9), an elliptical concave part (10), a wavy symmetrical groove (11), a boss (12), characterized in that, the upper and lower surfaces of the insert body (1) are symmetrically arranged, the relief surface (5) is located on the circumferential side surface of the insert body (1), the nose (6) is arranged along the top corner edge of the upper and lower surfaces of the insert body (1), the rake surface (4) is located inside the nose (6) and extends downward along the surface of the insert body (1) to form a closed continuous surface, the chip breaker bottom surface (7) extends horizontally from the rake surface (4) to the inside of the insert, the hemispherical convex part (9) and the elliptical concave part (10) are located between the chip breaker bottom surface (7) and the chip breaker surface (8), the chip breaker surface (8) extends upward from the hemispherical convex part (9) and the elliptical concave part (10) to the inside of the insert, the hemispherical convex part (9) is arranged in a pair on both sides of the diagonal line of the insert, the elliptical concave part (10) is arranged between the hemispherical convex parts (9) of the two top corners, the support surface (2) is arranged on the upper and lower surfaces of the insert body (1) and is respectively the highest and lowest position of the upper and lower surfaces of the entire insert body (1), the wavy symmetrical groove (11) is arranged on the support surface (2), the boss (12) is arranged between adjacent chip breaker surfaces (8), the outer profile of the boss (12) is round, the outer top surface of the boss (12) is at the same height as the support surface (2), the middle part of the boss (12) is vertically recessed in a hexagonal shape, and the bottom surface of the recessed part of the boss (12) is higher than the chip breaker bottom surface (7), the rake surface (4) includes a first rake surface (41) and a second rake surface (42), the first rake surface (41) and the second rake surface (42) are inclined inwardly and downwardly and form two different angles with the horizontal plane, the first rake angle γ1 and the second rake angle γ2, the relief surface (5) is consistent on the three side surfaces of the insert, and the normal relief angle of the relief surface (5) is 0°, the nose (6) includes a main cutting edge (61) composed of a straight line segment and a circular arc segment, a secondary cutting edge (62) extending away from the center of the nose, a chamfer (63) inclined downward and outward, and a land (64) extending between the main cutting edge (61) and the secondary cutting edge (62), the rake surface (4) forms two different angles with the horizontal plane, which gradually decreases in the direction of the secondary cutting edge (62), the chip breaker bottom surface (7) is connected with the second rake surface (42) and the chip breaker surface (8), and the width of the chip breaker bottom surface (7) gradually increases in the extension direction of the secondary cutting edge (62), and the angle θ formed by the chip breaker surface (8) and the horizontal plane gradually increases in the direction of the main cutting edge (61). ​ The convex platform (12) is provided with a smooth transition connecting arc surface (13) between the bottom surface of the chip breaker groove (7) and the chip breaker surface (8), and the whole material of the turning blade is prepared from Ti(C, N) based cermet.

2. The turning insert according to claim 1, characterized in that The angle α of the chamfer (63) is a negative angle of 10° at all cutting edges.

3. The turning insert according to claim 1, characterized in that The width of the land (64) gradually increases by 0.15mm-0.3mm along the extension direction of the sub cutting edge (62).

4. The turning insert according to claim 1, characterized in that The first rake angle γ1 gradually changes by 11°-15° from the sub cutting edge (62) to the main cutting edge (61), and the second rake angle γ2 gradually changes by 14°-18° from the sub cutting edge (62) to the main cutting edge (61).

5. The turning insert according to claim 1, characterized in that, The height from the bottom surface of the chip breaker groove (7) to the land (64) is the groove depth l, which gradually increases by 0.15mm-0.3mm along the extension direction of the sub cutting edge (62).

6. The turning insert according to claim 1, characterized in that The angle θ gradually changes by 30°-35° from the sub cutting edge (62) to the main cutting edge (61).

7. The turning insert according to claim 1, characterized in that The distance from the land (64) to the support surface (2) is the edge height h, which gradually changes by 0.1mm-0.2mm.

8. The turning insert according to claim 1, characterized in that The height of the semispherical convex part (9) is higher than the height of the land (64), and the distance between a pair of semispherical convex parts (9) is 0.2mm-0.3mm.

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