Milling insert and milling tool

Abstract

The utility model belongs to the technical field of milling cutters, and discloses a milling blade and a milling cutter. The milling blade comprises a blade body, the blade body comprises a curve cutting edge, the orthographic projection of the curve cutting edge in the axis direction of the blade body is in a circular arc shape, the circle center of the curve cutting edge is a circular arc center point, and the orthographic projection of the curve cutting edge in the direction perpendicular to the axis of the blade body is in a curve shape. The curve cutting edge is provided with an extrusion cutting part and a strength cutting part, the connecting line of the extrusion cutting part and the arc center point is a first connecting line, the connecting line of the strength cutting part and the arc center point is a second connecting line, and the first connecting line is perpendicular to the second connecting line; in the direction from the extrusion cutting part to the strength cutting part, the front angle gamma of the curve cutting edge in the normal direction is gradually reduced, the rear angle alpha of the curve cutting edge in the normal direction is gradually increased, and the wedge angle lambda of the curve cutting edge is not changed. The milling blade and the milling cutter provided by the utility model have longer service life.

Description

Technical Field

[0001] The utility model relates to the technical field of milling cutters, in particular to a milling blade and a milling cutter. Background Art

[0002] Ball-end milling cutters are widely used in fields such as molds and aerospace. Ball-end milling cutters primarily feature arc-shaped cutting edges, enabling a variety of milling operations, such as contour milling. During contour milling, the cutting point varies with the diameter of the arc profile. Therefore, the diameter of the ball-end milling cutter plays a key role in determining the linear speed of the cutting process.

[0003] In the prior art, such as Figure 6 and Figure 7 As shown, a ball-end milling tool generally includes a main body 1 having two blades 2, the two blades 2 being arranged on the circumferential side of the main body 1, and along the circumference of the main body 1, each blade 2 is the same distance from the top surface of the main body 1 in the axial direction, and the distance from each blade 2 to the bottom surface of the main body 1 in the axial direction is also the same. This type of blade can be called a straight blade. The angle of a ball-end milling tool with a straight blade is consistent in any working area, and its working rake angle is 0°. However, during the use of the ball-end milling tool, the blade 2 is subjected to greater cutting resistance, and the strength requirements of the cutting edge of the blade 2 are higher. The ball-end milling tool is more prone to premature failure, such as blade 2 wear, chipping, fracture, and other damage, resulting in a shorter service life of the ball-end milling tool. Utility Model Content

[0004] The purpose of the utility model is to provide a milling insert and a milling tool, which can improve the strength of the cutting edge and extend the service life of the milling insert.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A milling insert is provided, comprising an insert body, the insert body comprising a curved cutting edge, the orthographic projection of the curved cutting edge in the axial direction of the insert body being in the shape of an arc, the center of the curved cutting edge being the center point of the arc, the orthographic projection of the curved cutting edge in a direction perpendicular to the axial direction of the insert body being in the shape of a curve, the curved cutting edge comprising an extrusion cutting portion and a strengthening cutting portion, a connecting line between the extrusion cutting portion and the center point of the arc being a first connecting line, a connecting line between the strengthening cutting portion and the center point of the arc being a second connecting line, the first connecting line being perpendicular to the second connecting line;

[0007] Along the direction from the extrusion cutting portion to the strength cutting portion, the normal direction rake angle γ of the curved cutting edge gradually decreases, the normal direction clearance angle α of the curved cutting edge gradually increases, and the wedge angle λ of the curved cutting edge remains unchanged.

[0008] Optionally, the change in the normal direction front angle γ between the extrusion cutting portion and the strength cutting portion is less than or equal to 10°; and / or the change in the normal direction back angle α between the extrusion cutting portion and the strength cutting portion is less than or equal to 10°.

[0009] Optionally, the curved cutting edge includes a first intermediate cutting portion located between the extrusion cutting portion and the strength cutting portion, a connecting line between the first intermediate cutting portion and the center point of the arc is a third connecting line, and an angle between the third connecting line and the first connecting line is k1, wherein 0<k1<65°;

[0010] The change in the normal direction front angle γ between the extrusion cutting portion and the first intermediate cutting portion is greater than the change in the normal direction front angle γ between the first intermediate cutting portion and the strength cutting portion; and / or the change in the normal direction back angle α between the extrusion cutting portion and the first intermediate cutting portion is greater than the change in the normal direction back angle α between the first intermediate cutting portion and the strength cutting portion.

[0011] Optionally, the change in the normal direction front angle γ between the first intermediate cutting portion and the strength cutting portion is positively correlated with the angle between the third connecting line and the second connecting line; and / or the change in the normal direction back angle α between the first intermediate cutting portion and the strength cutting portion is positively correlated with the angle between the third connecting line and the second connecting line.

[0012] Optionally, the normal direction rake angle γ of the extrusion cutting portion is 0°±1°, and the normal direction clearance angle α of the extrusion cutting portion is 0°±1°;

[0013] and / or, the normal direction rake angle γ of the first intermediate cutting portion is -8.5°±1°, and the normal direction clearance angle α of the first intermediate cutting portion is 8.5°±1°;

[0014] And / or, the normal direction rake angle γ of the strength cutting portion is -9.5°±1°, and the normal direction clearance angle α of the strength cutting portion is 9.5°±1°.

[0015] Optionally, the curved cutting edge includes a second intermediate cutting portion located between the extrusion cutting portion and the strength cutting portion, a connecting line between the second intermediate cutting portion and the center point of the arc is a fourth connecting line, and an angle between the fourth connecting line and the first connecting line is k2, wherein 0<k2<35°;

[0016] The change amount of the normal direction rake angle γ in the second middle cutting portion is -5°±1°, and the change amount of the normal direction clearance angle α in the second middle cutting portion is 5°±1°.

[0017] Optionally, along the direction from the extrusion cutting portion to the strength cutting portion, a change in the normal direction rake angle γ of the curved cutting edge satisfies a cosine curve, and a change in the normal direction back angle α of the curved cutting edge satisfies a sine curve.

[0018] Optionally, the blade body includes at least one cutting edge group, each cutting edge group includes two curved cutting edges, the two curved cutting edges of one cutting edge group are centrally symmetrically arranged, and the extruded cutting portions of the two curved cutting edges are butted against each other.

[0019] Optionally, the blade body further includes a rake face, a first flank face, a second flank face and a chip return face, the rake face and the chip return face are arranged at an angle, the angle between the rake face and the first flank face is the wedge angle λ, and the second flank face is connected to the first flank face.

[0020] A milling tool is provided, comprising the milling insert as described above. The milling tool further comprises a tool shank, and a blade body of the milling insert is connected to the tool shank.

[0021] Beneficial effects of the utility model:

[0022] The milling insert and milling tool provided by the utility model have a curved cutting edge whose positive projection in a direction perpendicular to the axis of the blade body is curved, so that during the cutting process, the curved cutting edge can achieve progressive cutting, reducing the cutting resistance encountered by the curved cutting edge during the cutting process, thereby reducing the strength requirements for the curved cutting edge and reducing the cost of the milling insert. Moreover, the normal direction rake angle of any point on the curved cutting edge is angled, thereby improving the strength of the cutting edge and reducing the probability of premature failure of the milling insert, so that the milling insert and milling tool can have a longer service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of a blade body provided by an embodiment of the present utility model;

[0024] Figure 2It is a side view of the blade body provided by an embodiment of the present utility model;

[0025] Figure 3 This is a top view of the blade body provided by the embodiment of the utility model Figure 1 ;

[0026] Figure 4 This is a top view of the blade body provided by the embodiment of the utility model Figure 2 ;

[0027] Figure 5 It is a curve diagram of the change of the normal direction front angle and the normal direction back angle provided by the embodiment of the utility model;

[0028] Figure 6 This is a schematic structural diagram of a milling insert in the prior art provided by the present utility model;

[0029] Figure 7 It is a side view of the milling insert in the prior art provided by the utility model.

[0030] In the picture:

[0031] 10. Blade body;

[0032] 100, curved cutting edge; 110, extrusion cutting portion; 120, strength cutting portion; 130, first intermediate cutting portion; 140, second intermediate cutting portion;

[0033] 101, arc center point; 102, first connecting line; 103, second connecting line; 104, third connecting line; 105, fourth connecting line;

[0034] 200, rake face; 300, first flank face; 400, second flank face; 500, chip return face; 600, top face of tool; 710, first mounting and positioning face; 720, second mounting and positioning face; 800, threaded hole;

[0035] 1. Main body; 2. Blade. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0037] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0038] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0039] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0040] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0041] This embodiment provides a milling insert that has a longer service life and reduces the probability of premature failure.

[0042] like Figures 1 to 5 As shown, the milling insert includes an insert body 10. The insert body 10 includes a curved cutting edge 100, which is used to cut an object. The insert body 10 has an axis Z, as shown in FIG. Figure 3 As shown, the orthographic projection of the curved cutting edge 100 in the axial direction of the blade body 10 is in the shape of an arc, so that the cutting point will change with the change of the arc profile diameter, thereby being applicable to different milling processing methods and having a wide range of applications. Figure 3As shown, the center of the curved cutting edge 100 is the arc center point 101. In some optional embodiments, the center of the curved cutting edge 100 coincides with the geometric center of the blade body 10, so that the force on the curved cutting edge 100 can be relatively uniform. Of course, it is understandable that the center of the curved cutting edge 100 may not coincide with the geometric center of the blade body 10, and this embodiment is not limited to this.

[0043] In this embodiment, Figure 2 As shown, the positive projection of the curved cutting edge 100 in the direction perpendicular to the axis of the blade body 10 is curved rather than straight, that is, along the extension direction of the curved cutting edge 100, the distance from the curved cutting edge 100 to a surface in the axis direction of the blade body 10 is different, but gradually changes, so that progressive cutting can be achieved during the cutting process, thereby effectively reducing the cutting resistance during the cutting process. Therefore, the rake angle of the curved cutting edge 100 in the normal direction at any point can be angled, thereby improving the strength of the cutting edge of the curved cutting edge 100.

[0044] For example, Figure 4 As shown, the curved cutting edge 100 has an extrusion cutting portion 110 and a strength cutting portion 120. The extrusion cutting portion 110 and the strength cutting portion 120 are arranged opposite to each other. In this embodiment, the extrusion cutting portion 110 is used to cut an object in an extrusion manner, and the strength of the object cut by the strength cutting portion 120 is greater than the strength of the object cut by the extrusion cutting portion 110. The connecting line between the extrusion cutting portion 110 and the center point 101 of the arc is the first connecting line 102, and the connecting line between the strength cutting portion 120 and the center point 101 of the arc is the second connecting line 103. The first connecting line 102 is perpendicular to the second connecting line 103, that is, the angle formed by the first connecting line 102 and the second connecting line 103 is a right angle. Exemplarily, the extrusion cutting portion 110 is the reference, that is, when the extrusion cutting portion 110 is at the 0° position, the strength cutting portion 120 is at the 90° position.

[0045] Along the direction from the extrusion cutting portion 110 to the strength cutting portion 120, that is, along Figure 3 In the R direction shown, the normal rake angle γ of the curved cutting edge 100 gradually decreases, the normal clearance angle α of the curved cutting edge 100 gradually increases, and the wedge angle λ of the curved cutting edge 100 remains unchanged. In this embodiment, along the direction from the extrusion cutting portion 110 to the strength cutting portion 120, the normal rake angle γ and the normal clearance angle α change in the same trend to ensure that the wedge angle λ remains unchanged. For example, the wedge angle λ in this embodiment is an obtuse angle. It should be noted that the wedge angle λ = 90° - normal rake angle γ - normal clearance angle α.

[0046] In some optional embodiments, such as Figure 1As shown, the blade body 10 further includes a rake face 200, a first flank face 300, a second flank face 400 and a chip return face 500. The rake face 200 and the chip return face 500 are arranged at an angle, and the angle between the rake face 200 and the first flank face 300 is a wedge angle λ, that is, the rake face 200 and the first flank face 300 form a curved cutting edge 100. The second flank face 400 is arranged in a butt joint with the first flank face 300. For example, as Figure 1 As shown, the blade body 10 also includes a tool top 600, a first mounting and positioning surface 710, and a second mounting and positioning surface 720. A portion of the blade body 10 is sunken to form the rake face 200 and the chip return surface 500. The first mounting and positioning surfaces 710 and 720 are both located on the side of the blade body 10 and are used to position the blade body 10 during installation. The tool top 600 also has a threaded hole 800, which is used to mount the blade body 10 to the handle.

[0047] It should be noted that if Figure 3 As shown, the normal direction rake angle γ refers to the angle of the rake face 200 relative to the straight line extending radially from the arc center point 101 toward the curved cutting edge 100, and can also be called the "radial direction rake angle". The normal direction clearance angle α refers to the angle of the first clearance face 300 relative to the straight line perpendicular to the straight line extending radially from the arc center point 101 toward the curved cutting edge 100, and can also be called the "radial direction clearance angle".

[0048] In this embodiment, the normal rake angle γ is located on one side of the radially extending straight line and is a negative value; the normal clearance angle α is located on the other side of the radially extending straight line and is a positive value. The normal rake angle γ of the curved cutting edge 100 gradually decreases along the direction from the extrusion cutting portion 110 to the strengthening cutting portion 120. Specifically, this means that the absolute value of the normal rake angle γ gradually increases. However, since this value is negative, it can be considered that the normal rake angle γ gradually decreases. The normal clearance angle α of the curved cutting edge 100 gradually increases along the direction from the extrusion cutting portion 110 to the strengthening cutting portion 120. Specifically, this means that the value of the normal clearance angle α increases.

[0049] In some optional embodiments, the extrusion cutting portion 110 is located at the blade body 10. Figure 3 The bottom of the state, the strength cutting portion 120 is located at the blade body 10 Figure 3 The extrusion cutting portion 110 is usually an end portion of the curved cutting edge 100, but it can also be an end portion of the curved cutting edge 100, which is not limited in this embodiment. The strength cutting portion 120 can be the other end portion of the curved cutting edge 100, and it can be understood that Figure 4As shown, the strength cutting portion 120 may not be the other end portion of the curved cutting edge 100 , and this embodiment does not limit this.

[0050] During the profile milling process of steel parts covered with high-hardness materials, the linear speed will be different due to the dynamic changes of the cutting point of the curved cutting edge 100, so the strength requirements of different positions of the cutting edge of the curved cutting edge 100 are different. For example, in the extrusion cutting part 110, that is, at the 0° position, since the diameter of this position is 0, the linear speed is 0. During the cutting process, the main processing method is the extrusion processing method. For this reason, the normal direction front angle γ of the curved cutting edge 100 is required to be large, and the normal direction back angle α is required to be large, so as to better discharge the chips and obtain better processing surface quality.

[0051] As the cutting point gradually moves from the extrusion cutting portion 110 to the strength cutting portion 120, the diameter of the cutting point becomes larger and larger, and the actual cutting linear velocity also becomes larger and larger. The increase in linear velocity requires the edge strength of the milling tool to increase. At this time, it is necessary to design the normal rake angle γ to be more negative, that is, the normal rake angle γ is smaller, so as to improve the strength of the front cutting face 200 of the curved cutting edge 100. At the same time, it is necessary to maintain a steady state of strength during the cutting process. If the normal clearance angle α is not adjusted at this time, it will have a very large impact on the vibration of the cutting process and the surface quality of the cutting back face. Therefore, it is necessary to increase the normal clearance angle α as the normal rake angle γ is designed to be more negative. At the same time, it is necessary to maintain a steady state of strength during the cutting process. Since the wedge angle λ is constant, the change in the normal rake angle γ and the normal clearance angle α needs to be consistent, so as to achieve a steady state of strength during the cutting process.

[0052] The milling insert provided in this embodiment has a curved cutting edge 100 whose projection in the direction perpendicular to the axis of the insert body 10 is curved, so that during the cutting process, the curved cutting edge 100 can achieve progressive cutting, reducing the cutting resistance encountered by the curved cutting edge 100 during the cutting process, thereby reducing the strength requirements for the curved cutting edge 100 and reducing the cost of the milling insert. Moreover, the normal direction rake angle of any point on the curved cutting edge 100 is angled, thereby improving the strength of the cutting edge and reducing the probability of premature failure of the milling insert, so that the milling tool using the cutting insert in the cutting insert machine can have a longer service life.

[0053] In some optional embodiments, the variation of the normal rake angle γ between the extrusion cutting portion 110 and the strength cutting portion 120 is less than or equal to 10°. This ensures that the curved cutting edge 100 has a high strength while maintaining a steady-state strength process while ensuring the strength of the rake face 200. This reduces the risk of premature failure of the curved cutting edge 100 due to drastic changes in the normal rake angle γ. For example, the variation of the normal rake angle γ between the extrusion cutting portion 110 and the strength cutting portion 120 is 10°, 9.5°, 9°, 8.5°, and 8°.

[0054] Optionally, the variation in the normal-direction clearance angle α between the extrusion cutting portion 110 and the strengthening cutting portion 120 is less than or equal to 10°. This allows the curved cutting edge 100 to maintain a steady-state strength while ensuring the strength of the first flank surface 300, thereby preventing premature failure. For example, the variation in the normal-direction clearance angle α between the extrusion cutting portion 110 and the strengthening cutting portion 120 is 10°, 9.5°, 9°, 8.5°, and 8°.

[0055] Exemplarily, the curved cutting edge 100 includes a first intermediate cutting portion 130 located between the extrusion cutting portion 110 and the strength cutting portion 120. The connecting line between the first intermediate cutting portion 130 and the arc center point 101 is a third connecting line 104. The angle between the third connecting line 104 and the first connecting line 102 is k1, where 0 < k1 < 65°. For example, k1 = 60°, 55°, 64°, 62°, or 58°.

[0056] In this embodiment, the change in the normal-direction rake angle γ between the extrusion cutting portion 110 and the first intermediate cutting portion 130 is greater than the change in the normal-direction rake angle γ between the first intermediate cutting portion 130 and the strengthening cutting portion 120. That is, the change in the normal-direction rake angle γ from the 0° position to the k1 position is greater, while the change in the normal-direction rake angle γ from the k1 position to the 90° position is smaller. Correspondingly, the change in the normal-direction clearance angle α between the extrusion cutting portion 110 and the first intermediate cutting portion 130 is greater than the change in the normal-direction clearance angle α between the first intermediate cutting portion 130 and the strengthening cutting portion 120. That is, the change in the normal-direction clearance angle α from the 0° position to the k1 position is greater, while the change in the normal-direction clearance angle α from the k1 position to the 90° position is smaller.

[0057] In this way, the strength of the curved cutting edge 100 can be gradually improved on the basis of ensuring better chip discharge and improving the surface quality of the processed surface, so that the strength can be improved more quickly before the cutting point reaches the first intermediate cutting part 130, thereby reducing the probability of premature failure of the curved cutting edge 100. The strength at the first intermediate cutting part 130 is already high, so the rate of increase in strength can be slowed down by controlling the change in the normal direction front angle γ and the normal direction back angle α to ensure the chip discharge effect and the surface quality of the processed surface.

[0058] It should be noted that the variation in the normal rake angle γ (or normal clearance angle α) between the extrusion cutting portion 110 and the first intermediate cutting portion 130 is specifically the difference between the normal rake angle γ (or normal clearance angle α) at ​​the cutting point on the curved cutting edge 100 located between the extrusion cutting portion 110 and the first intermediate cutting portion 130 and the normal rake angle γ (or normal clearance angle α) at ​​the extrusion cutting portion 110. Similarly, the variation in the normal rake angle γ (or normal clearance angle α) between the first intermediate cutting portion 130 and the strength cutting portion 120 is specifically the difference between the normal rake angle γ (or normal clearance angle α) at ​​the cutting point on the curved cutting edge 100 located between the first intermediate cutting portion 130 and the strength cutting portion 120 and the normal rake angle γ (or normal clearance angle α) at ​​the extrusion cutting portion 110. It can be seen that the variations in this embodiment are all based on the parameters at the extrusion cutting portion 110.

[0059] In some optional embodiments, the change in the normal rake angle γ between the first intermediate cutting portion 130 and the strength cutting portion 120 is positively correlated with the angle between the third connecting line 104 and the second connecting line 103. That is, the closer to the strength cutting portion 120, the smaller the change in the normal rake angle γ. This prevents failure of the curved cutting edge 100 caused by a sudden change in the normal rake angle γ, thereby ensuring a steady-state strength during the cutting process. It should be noted that the normal rake angle γ reaches its minimum at the strength cutting portion 120.

[0060] Correspondingly, the change in the normal clearance angle α between the first intermediate cutting portion 130 and the strengthening cutting portion 120 is positively correlated with the angle between the third connecting line 104 and the second connecting line 103. That is, the closer to the strengthening cutting portion 120, the smaller the change in the normal clearance angle α. It should be noted that the normal clearance angle α reaches its maximum at the strengthening cutting portion 120.

[0061] In some optional embodiments, the normal direction rake angle γ of the extrusion cutting portion 110 is 0°±1°, and the normal direction clearance angle α of the extrusion cutting portion 110 is 0°±1°. For example, the normal direction rake angle γ of the extrusion cutting portion 110 is 0°, 0.1°, -1°, +1°, or -0.1°. The normal direction clearance angle α of the extrusion cutting portion 110 is 0°, 0.1°, -1°, +1°, or -0.1°.

[0062] In some optional embodiments, the normal direction rake angle γ of the first intermediate cutting portion 130 is -8.5°±1°, and the normal direction clearance angle α of the first intermediate cutting portion 130 is 8.5°±1°. For example, the normal direction rake angle γ of the first intermediate cutting portion 130 is -8.5°, -9.5°, -7.5°, -7.8°, or -9°. The normal direction clearance angle α of the first intermediate cutting portion 130 is 8.5°, 9.5°, 7.5°, 8°, or 9°.

[0063] In some optional embodiments, the normal direction rake angle γ of the strength cutting portion 120 is -9.5°±1°, and the normal direction clearance angle α of the strength cutting portion 120 is 9.5°±1°. For example, the normal direction rake angle γ of the strength cutting portion 120 is -9.5°, -8.5°, -10.5°, -10°, or -9°. The normal direction clearance angle α of the strength cutting portion 120 is 9.5°, 10.5°, 8.5°, 9°, or 10°.

[0064] For example, please see Figure 4 The curved cutting edge 100 further includes a second intermediate cutting portion 140 located between the extrusion cutting portion 110 and the strengthening cutting portion 120. A connecting line between the second intermediate cutting portion 140 and the arc center point 101 is a fourth connecting line 105. The angle between the fourth connecting line 105 and the first connecting line 102 is k2, where 0 < k2 < 35°. For example, K2 = 34°, 34°, 33°, 32°, 31°, 30°, 29°, or 28°.

[0065] In some optional embodiments, the second middle cutting portion 140 is located between the first middle cutting portion 130 and the extrusion cutting portion 110 .

[0066] In this embodiment, the normal direction rake angle γ of the second intermediate cutting portion 140 is -5°±1°, and the normal direction clearance angle α of the second intermediate cutting portion 140 is 5°±1°. For example, the normal direction rake angle γ of the second intermediate cutting portion 140 is -5°, -4°, -6°, -5.4°, or -5.5°. The normal direction clearance angle α of the second intermediate cutting portion 140 is 5°, 4°, 6°, 4.5°, or 5.5°.

[0067] For example, Figure 5As shown, along the direction from the extrusion cutting portion 110 to the strength cutting portion 120, the change in the normal direction rake angle γ of the curved cutting edge 100 satisfies the cosine curve, and the change in the normal direction clearance angle α of the curved cutting edge 100 satisfies the sine curve, that is, the values ​​of the changes in the normal direction rake angle γ and the normal direction clearance angle α are the same, but the signs are opposite, so as to ensure that the wedge angle λ remains consistent on the entire curved cutting edge 100, ensure the steady state of strength during the cutting process, improve the effect and quality of the cutting process, and at the same time improve the service life and strength of the curved cutting edge 100.

[0068] Alternatively, as Figure 1 As shown, the blade body 10 includes at least one cutting edge group (not shown in the figure), Figure 1 The figure is a schematic diagram showing that the blade body 10 includes one cutting edge group. The number of cutting edge groups may also be 2, 3, etc., which is not limited in this embodiment.

[0069] Each cutting edge group includes two of the aforementioned curved cutting edges 100. The two curved cutting edges 100 of a cutting edge group are arranged symmetrically with respect to the center, and the extruded cutting portions 110 of the two curved cutting edges 100 are butted together. This allows the two curved cutting edges 100 to be adapted to different cutting requirements, providing greater flexibility in the cutting process. By butting the extruded cutting portions 110 of the two curved cutting edges 100 together, the resulting cutting edge group is shaped similar to an "S" shape, further enabling progressive cutting during the cutting process, effectively reducing cutting resistance during the cutting process, and increasing the strength of each curved cutting edge 100.

[0070] This embodiment also provides a milling tool, comprising the milling insert as described above. The milling tool further comprises a tool bar, to which a blade body 10 of the milling insert is connected. The milling tool provided in this embodiment can have a long service life and high strength.

[0071] For example, the milling tool may be a ball-end milling tool, or may be other milling tools, which is not limited in this embodiment.

[0072] The milling blade provided in this embodiment has a fixed wedge angle λ matched with a normal direction rake angle γ and a normal direction back angle α, and focuses on the changes of the three most important angles in the structure of the milling blade to meet the problem that the dynamic change of the cutting point leads to different linear velocities during the copy milling process of high-hardness steel parts, thereby requiring different strength requirements at different positions of the cutting edge. Specifically, by approximating the change of the normal direction rake angle γ to a cosine function and the change of the normal direction back angle α to a sine function, the actual cutting process is simulated, where the linear velocity of the extrusion cutting part 110 (0° position) at the bottom center of the arc is 0, and the linear velocity of the strength cutting part 120 (90° position) is the maximum, thereby solving the functional change of strength and sharpness from 0° to 90°, thereby achieving consistency of the wedge angle λ of the milling tool, ensuring the steady state of strength during the cutting process, and thus improving the copy milling life and strength of the milling blade.

[0073] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A milling insert comprising an insert body (10), characterized in that The blade body (10) comprises a curved cutting edge (100), wherein the orthographic projection of the curved cutting edge (100) in the axial direction of the blade body (10) is in the shape of an arc, and the center of the curved cutting edge (100) is the arc center point (101), and the orthographic projection of the curved cutting edge (100) in the direction perpendicular to the axial direction of the blade body (10) is in the shape of a curve, and the curved cutting edge (100) has an extrusion cutting portion (110) and a strength cutting portion (120), a connecting line between the extrusion cutting portion (110) and the arc center point (101) is a first connecting line (102), and a connecting line between the strength cutting portion (120) and the arc center point (101) is a second connecting line (103), and the first connecting line (102) is perpendicular to the second connecting line (103); Along the direction from the extrusion cutting portion (110) to the strength cutting portion (120), the normal direction rake angle γ of the curved cutting edge (100) gradually decreases, the normal direction clearance angle α of the curved cutting edge (100) gradually increases, and the wedge angle λ of the curved cutting edge (100) remains unchanged.

2. The milling insert according to claim 1, characterized in that The amount of change of the normal-direction rake angle γ between the extrusion cutting portion (110) and the strength cutting portion (120) is less than or equal to 10°; and / or the amount of change of the normal-direction clearance angle α between the extrusion cutting portion (110) and the strength cutting portion (120) is less than or equal to 10°.

3. The milling insert according to claim 1, characterized in that The curved cutting edge (100) comprises a first intermediate cutting portion (130) located between the extrusion cutting portion (110) and the strength cutting portion (120); a connecting line between the first intermediate cutting portion (130) and the arc center point (101) is a third connecting line (104); an angle between the third connecting line (104) and the first connecting line (102) is k1, wherein 0<k1<65°; The amount of change of the normal-direction rake angle γ between the extrusion cutting portion (110) and the first intermediate cutting portion (130) is greater than the amount of change of the normal-direction rake angle γ between the first intermediate cutting portion (130) and the strength cutting portion (120); and / or the amount of change of the normal-direction clearance angle α between the extrusion cutting portion (110) and the first intermediate cutting portion (130) is greater than the amount of change of the normal-direction clearance angle α between the first intermediate cutting portion (130) and the strength cutting portion (120).

4. The milling insert according to claim 3, characterized in that The variation of the normal-direction front angle γ between the first intermediate cutting portion (130) and the strength cutting portion (120) is positively correlated with the angle between the third connecting line (104) and the second connecting line (103); and / or the variation of the normal-direction back angle α between the first intermediate cutting portion (130) and the strength cutting portion (120) is positively correlated with the angle between the third connecting line (104) and the second connecting line (103).

5. The milling insert according to claim 3, characterized in that The normal direction rake angle γ of the extrusion cutting portion (110) is 0°±1°, and the normal direction clearance angle α of the extrusion cutting portion (110) is 0°±1°; and / or the normal direction rake angle γ of the first intermediate cutting portion (130) is -8.5°±1°, and the normal direction clearance angle α of the first intermediate cutting portion (130) is 8.5°±1°; And / or, the normal direction front angle γ of the strength cutting portion (120) is -9.5°±1°, and the normal direction back angle α of the strength cutting portion (120) is 9.5°±1°.

6. The milling insert according to any one of claims 1 to 5, characterized in that The curved cutting edge (100) comprises a second intermediate cutting portion (140) located between the extrusion cutting portion (110) and the strength cutting portion (120); a connecting line between the second intermediate cutting portion (140) and the arc center point (101) is a fourth connecting line (105); an angle between the fourth connecting line (105) and the first connecting line (102) is k2, wherein 0<k2<35°; The amount of change of the normal direction rake angle γ in the second intermediate cutting portion (140) is -5°±1°, and the amount of change of the normal direction clearance angle α in the second intermediate cutting portion (140) is 5°±1°.

7. The milling insert according to any one of claims 1 to 5, characterized in that Along the direction from the extrusion cutting portion (110) to the strength cutting portion (120), a change in the normal direction rake angle γ of the curved cutting edge (100) satisfies a cosine curve, and a change in the normal direction back angle α of the curved cutting edge (100) satisfies a sine curve.

8. The milling insert according to any one of claims 1 to 5, characterized in that The blade body (10) comprises at least one cutting edge group, each cutting edge group comprises two curved cutting edges (100), the two curved cutting edges (100) of one cutting edge group are centrally symmetrically arranged, and the extruded cutting portions (110) of the two curved cutting edges (100) are butted.

9. The milling insert according to any one of claims 1 to 5, characterized in that: The blade body (10) further comprises a front cutting surface (200), a first back cutting surface (300), a second back cutting surface (400) and a chip return surface (500); the front cutting surface (200) and the chip return surface (500) are arranged at an angle; the angle between the front cutting surface (200) and the first back cutting surface (300) is the wedge angle λ; the second back cutting surface (400) and the first back cutting surface (300) are butted against each other.

10. Milling tool, characterized in that The milling tool comprises the milling insert according to any one of claims 1 to 9, wherein the milling tool further comprises a tool shank, and the insert body (10) of the milling insert is connected to the tool shank.

Images