Cutting insert and cutting tool

Abstract

A cutting insert (1) has upper and lower opposite upper surface (11), lower surface (13), located between the outer peripheral surface (16) of the upper and lower surface, located in the upper surface (11) of the outer edge of the upper cutting edge (12), located in the lower surface (13) of the outer edge of the lower cutting edge (14), and through the upper and lower surface of the center axis (L5); upper cutting edge (12) includes upper corner edge (121), upper main cutting edge (122) and upper sub cutting edge (123), lower cutting edge (14) includes lower corner edge (141), lower main cutting edge (142) and lower sub cutting edge (143); the outer peripheral surface (16) includes corner side surface (161), first side surface (162), second side surface (163), third side surface (164) and fourth side surface (165); first side surface (162) is connected with upper main cutting edge (122), second side surface (163) is connected with lower main cutting edge (142), first side surface (162) and second side surface (163) are parallel to the center axis (L5); third side surface (164) is connected with lower sub cutting edge (143), and is inclined away from the center axis (L5) with the distance from lower sub cutting edge (143); fourth side surface (165) is connected with upper sub cutting edge (123), and is inclined away from the center axis (L5) with the distance from upper sub cutting edge (123). The present application can improve the quality of the machining surface of the cutting insert used on both sides. A cutting tool is also provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cutters, in particular to a cutting insert and a cutting tool. BACKGROUND

[0002] Chinese patent CN103071821B discloses a indexable cutting insert, which includes a plurality of cutting corners having a continuous curved cutting edge thereon, a flank surface on each side of each cutting corner, wherein one flank surface has a positive clearance angle with respect to a central axis of the pocket opening and the other flank surface has a negative clearance angle with respect to the central axis of the pocket opening. Each cutting corner has two part surfaces which abut each other along a line extending along the central axis of the pocket opening.

[0003] In the solution disclosed in the patent, the upper and lower surfaces of the insert form cutting edges, so that the insert can be used on both sides. However, in the insert structure disclosed in the patent, when the upper surface side cutting edge is used for machining, the clearance surface corresponding to the lower surface side cutting edge is easy to contact the machined workpiece. This is because the radial rake angle of the insert needs to be set to a negative angle during cutting, that is, the insert needs to be installed on the holder with the insert tilted forward. Since the flank surface is inclined, the sub-cutting edge on the lower surface side has a positive clearance surface, which is easy to be located behind the rotation direction along the clearance surface of the sub-cutting edge, and contacts the machined surface machined by the main cutting edge on the upper surface side, affecting the surface quality of the machined surface. SUMMARY

[0004] An object of the present application is to provide a cutting insert to improve the surface quality of the machined surface of the cutting insert used on both sides.

[0005] Another object of the present application is to provide a cutting tool having the above cutting insert.

[0006] To solve the above technical problems, the present application adopts the following technical solutions:

[0007] According to one aspect of the present application, the present application provides a cutting insert, having:

[0008] an upper surface, having:

[0009] a first upper edge;

[0010] a second upper edge intersecting the first upper edge; and

[0011] an upper corner at an intersection of the first upper edge and the second upper edge;

[0012] an upper cutting edge at an outer edge of the upper surface, comprising:

[0013] upper corner edge located at the upper corner;

[0014] upper primary cutting edge located at the first upper edge and connected to the upper corner edge; and

[0015] upper secondary cutting edge located at the second upper edge and connected to the upper corner edge;

[0016] lower surface having:

[0017] first lower edge located below the second upper edge;

[0018] second lower edge intersecting the first lower edge and located below the first upper edge; and

[0019] lower corner located at the intersection of the first lower edge and the second lower edge;

[0020] lower cutting edge located at the outer edge of the lower surface, comprising:

[0021] lower corner edge located at the lower corner;

[0022] lower primary cutting edge located at the first lower edge and connected to the lower corner edge; and

[0023] lower secondary cutting edge located at the second lower edge and connected to the lower corner edge;

[0024] central axis passing through the center of the upper surface and the center of the lower surface; and

[0025] outer peripheral surface located between the upper surface and the lower surface, comprising:

[0026] corner side surface connecting the upper corner and the lower corner;

[0027] first side surface connecting the first upper edge, connected to the upper primary cutting edge, and parallel to the central axis;

[0028] second side surface connecting the first lower edge, connected to the lower primary cutting edge, and parallel to the central axis;

[0029] third side surface located between the corner side surface and the first side surface, connecting the second lower edge, connected to the lower secondary cutting edge, and inclined away from the central axis as it moves away from the lower secondary cutting edge; and

[0030] fourth side surface located between the corner side surface and the second side surface, connecting the second upper edge, connected to the upper secondary cutting edge, and inclined away from the central axis as it moves away from the upper secondary cutting edge.

[0031] In some embodiments, the upper primary cutting edge and the lower secondary cutting edge are opposite to each other, and the lower secondary cutting edge is more biased to the central axis than the upper primary cutting edge.

[0032] In some embodiments, 0<θ≤10°.

[0033] In some embodiments, the extension length of the upper primary cutting edge is greater than that of the upper secondary cutting edge; the extension length of the lower primary cutting edge is greater than that of the lower secondary cutting edge.

[0034] In some embodiments, the first side surface, the second side surface, the third side surface and the fourth side surface are all planar.

[0035] In some embodiments, the upper corner and the lower corner are centrally symmetric; when viewed from the upper surface, the end point of the lower corner where it meets the first lower edge is further away from the central axis than the end point of the upper corner where it meets the second upper edge, and the end point of the lower corner where it meets the second lower edge is closer to the central axis than the end point of the upper corner where it meets the first upper edge.

[0036] In some embodiments, the upper corner and the lower corner are both in the shape of a circular arc and are both perpendicular to the central axis; on any cross section between the upper surface and the lower surface that is perpendicular to the central axis, the extension shape of the corner side surface is the same as that of the upper corner and the lower corner.

[0037] In some embodiments, the width of the third side surface gradually decreases as it moves away from the lower secondary cutting edge; the width of the fourth side surface gradually decreases as it moves away from the upper secondary cutting edge.

[0038] In some embodiments, the upper end of the third side surface is adjacent to the junction of the upper corner and the first upper edge; the lower end of the fourth side surface is adjacent to the junction of the lower corner and the first lower edge.

[0039] In some embodiments, the upper surface further comprises an upper rake surface disposed along the upper cutting edge, which is closer to the lower surface as it moves away from the upper cutting edge in the direction of the central axis.

[0040] In some embodiments, the upper surface further comprises a constraint surface disposed around the central axis and perpendicular to the central axis, which is closer to the lower surface than the upper cutting edge.

[0041] According to another aspect of the present application, the present application provides a cutting tool comprising a tool shank and a cutting insert as described above mounted on the tool shank.

[0042] The cutting blade in the present application is provided with an upper cutting edge on the upper surface and a lower cutting edge on the lower surface, and the upper cutting edge and the lower cutting edge are used simultaneously. When the upper cutting edge is used to cut the workpiece, the upper main cutting edge of the upper cutting edge cuts the side end surface of the workpiece, and the first side surface and the third side surface of the outer circumferential surface face the side end surface of the workpiece. Since the third side surface is inclined away from the central axis with the distance from the lower minor cutting edge, the third side surface is less likely to contact the side end surface of the workpiece than the first side surface, so that the existence of the lower cutting edge does not affect the quality of the surface machined by the upper cutting edge. Similarly, when the lower cutting edge is used to cut the workpiece, the second side surface and the fourth side surface face the side end surface of the workpiece. Since the fourth side surface is inclined away from the central axis with the distance from the upper minor cutting edge, the fourth side surface is less likely to contact the side end surface of the workpiece than the second side surface, so that the existence of the upper cutting edge does not affect the quality of the surface machined by the lower cutting edge. In summary, the upper cutting edge and the lower cutting edge of the cutting blade do not affect each other in machining, and the quality of the machined surface can be improved for the cutting blade used on both surfaces. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 is a structure schematic diagram of the perspective view of the cutting blade of an embodiment of the present application.

[0044] Figure 2 is Figure 1 the front view of the cutting blade.

[0045] Figure 3 is Figure 2 the partial enlarged view of K in

[0046] Figure 4 is Figure 2 the view of M in

[0047] Figure 5 is Figure 4 the view of N in

[0048] Figure 6 is Figure 1 the partial enlarged view of J in

[0049] Figure 7 is also Figure 2 the partial enlarged view of K in

[0050] Figure 8 is Figure 7 the A-A sectional view in

[0051] Figure 9 is Figure 7 the B-B sectional view in

[0052] Figure 10 is Figure 7 a cross-sectional view taken along line C-C in

[0053] Figure 11 is Figure 7 a cross-sectional view taken along line D-D in

[0054] Figure 12 is Figure 7 a cross-sectional view taken along line E-E in

[0055] Figure 13 is Figure 7 a cross-sectional view taken along line F-F in

[0056] Figure 14 is Figure 7 a cross-sectional view taken along line G-G in

[0057] Figure 15 is a schematic view of a cutting tool comprising a cutting insert according to Figure 1

[0058] Figure 16 is Figure 15 a close-up view of the area T in

[0059] Figure 17 is Figure 16 a schematic view of the cutting tool after removal of the cutting insert in

[0060] Figure 18 is Figure 15 a close-up view of the area V in

[0061] Figure 19 is a schematic view of a cutting insert according to another embodiment of the present application.

[0062] The reference signs are explained as follows:

[0063] 1. cutting insert

[0064] 11. upper surface; 111. upper corner; 112. first upper land; 113. second upper land; 114. upper rake surface; 1142. main upper rake surface; 1143. minor upper rake surface; 115. upper constraint surface; 116. upper transition surface

[0065] 12. upper cutting edge; 121. upper corner cutting edge; 122. main upper cutting edge; 1221. first straight portion; 1222. first transition portion; 123. minor upper cutting edge; 1231. second straight portion; 1232. second transition portion

[0066] 13. lower surface; 131. lower corner; 132. first lower land; 133. second lower land

[0067] ​14, lower cutting edge; 141, lower corner edge; 142, lower primary cutting edge; 143, lower secondary cutting edge;

[0068] 15, center hole; L1, center axis;

[0069] 16, outer peripheral surface; 161, corner side surface; 162, first side surface; 163, second side surface; 164, third side surface; 165, fourth side surface;

[0070] 2, shank; 21, mounting groove; 211, seating surface; 212, side surface; L2, rotation axis;

[0071] 3, fastener;

[0072] 4, workpiece; 41, side end surface; 42, bottom surface;

[0073] 5, cutting insert;

[0074] 51, upper surface; 511, upper corner; 512, first upper land; 513, second upper land;

[0075] 52, upper cutting edge; 521, upper corner edge; 522, upper primary cutting edge; 523, upper secondary cutting edge;

[0076] 53, lower surface; 531, lower corner; 532, first lower land; 533, second lower land;

[0077] 54, lower cutting edge; 541, lower corner edge; 542, lower primary cutting edge; 543, lower secondary cutting edge;

[0078] 55, center hole; L5, center axis;

[0079] 56, outer peripheral surface; 561, corner side surface; 562, first side surface; 563, second side surface; 564, third side surface; 565, fourth side surface. DETAILED DESCRIPTION

[0080] Embodiments that embody the principles of the application are described in detail herein. It should be understood that the application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these described embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0081] The present application provides a cutting insert and a tool having the same, the tool including a shank for mounting the cutting insert.

[0082] Figures 1 to 14 a schematic view of a cutting insert 1 according to an embodiment of the present application, Figure 15 a schematic view of the cutting insert 1 mounted on a shank 2.

[0083] First refer to Figures 1 to 4 This embodiment provides a cutting insert 1 that is indexable and can be used on both sides.

[0084] The cutting insert 1 has an upper surface 11, a lower surface 13, and an outer peripheral surface 16 located between the upper surface 11 and the lower surface 13. An upper cutting edge 12 is provided on the outer edge of the upper surface 11, and a lower cutting edge 14 is provided on the outer edge of the lower surface 13, allowing for cutting operations using the upper cutting edge 12 and the lower cutting edge 14 respectively. The cutting insert 1 also has a central hole 15 penetrating the upper surface 11 and the lower surface 13, which is used for a fastener 3 to pass through so that the cutting insert 1 can be mounted on a tool holder 2 (e.g., ...). Figure 15 (As shown). The outer edges of the upper surface 11 and the lower surface 13 are both rotationally symmetric figures, and the center of the upper surface 11 and the center of the lower surface 13 are both located on the central axis L1 of the central hole 15.

[0085] It should be noted that the terms "upper" and "lower" are artificially defined for ease of description. In fact, by flipping the cutting blade 1 up and down, the upper surface 11 and the lower surface 13 can be interchanged.

[0086] The following is a detailed introduction to the upper surface 11.

[0087] In this embodiment, the upper surface 11 is roughly square in shape, and the outer edge of the upper surface 11 has four upper corners 111 and upper edges that connect each upper corner 111 respectively.

[0088] by Figure 1 Looking at the upper corner 111 located in the middle, the outer edge of the upper surface 11 includes a first upper edge 112, a second upper edge 113 intersecting with the first upper edge 112, and an upper corner 111 located at the intersection of the first upper edge 112 and the second upper edge 113. The upper corner 111 is arc-shaped, and the first upper edge 112 and the second upper edge 113 respectively connect the two ends of the arc of the upper corner 111.

[0089] The first upper edge 112, the upper corner 111, and the second upper edge 113 are each a unit. The outer edge of the entire upper surface 11 is composed of four such units connected end to end, and the four units are rotationally symmetrical about the central axis L1.

[0090] The upper cutting edge 12, correspondingly located at the outer edge of the upper surface 11, includes an upper corner cutting edge 121 at the upper corner 111, an upper main cutting edge 122 at the first upper edge 112, and an upper secondary cutting edge 123 at the second upper edge 113. The upper corner cutting edge 121 extends in an arc shape and is perpendicular to the central axis L1. The upper main cutting edge 122 and the upper secondary cutting edge 123 are located on both sides of the upper corner cutting edge 121 and are respectively connected to the two ends of the arc of the upper corner cutting edge 121.

[0091] In the cutting process, the workpiece is machined, for example, a right-angle surface, by a combination of an upper corner blade 121 and an upper main cutting blade 122 and an upper auxiliary cutting blade 123 connected with the upper corner blade 121.

[0092] The upper cutting blades 12 are arranged in four along the outer edge of the upper surface 11 in rotational symmetry, and by rotating the cutting blade 1 to adjust the mounting position of the cutting blade 1 relative to the shank 2, the four upper cutting blades 12 can be adjusted to the cutting working state respectively.

[0093] Referring to Figure 2 The end of the upper main cutting blade 122 of each upper cutting blade 12 away from the upper corner blade 121 is connected with the end of the upper auxiliary cutting blade 123 of another upper cutting blade 12 away from the upper corner blade 121, that is, there is an upper main cutting blade 122 and an upper auxiliary cutting blade 123 between the two adjacent upper corner blades 121. For the structure of the upper surface 11 being substantially square in this embodiment, the upper main cutting blade 122 and the upper auxiliary cutting blade 123 between the two adjacent upper corner blades 121 constitute a side of the square, but the side is not a straight line, and the upper auxiliary cutting blade 123 is inclined to the center axis L1 direction away from the upper main cutting blade 122. As shown in Figure 3 The upper auxiliary cutting blade 123 forms an included angle θ with the extension line of the upper main cutting blade 122, and in some embodiments, preferably 0 < θ ≤ 10°.

[0094] Preferably, the upper main cutting blade 122 extends in a plane, and the upper auxiliary cutting blade 123 extends in another plane, so that the machined surfaces machined by the upper main cutting blade 122 and the upper auxiliary cutting blade 123 can form planes, ensuring the flatness of the machined surfaces and the angle accuracy between the two machined surfaces.

[0095] In combination Figure 3 and Figure 4 In this embodiment, the upper main cutting blade 122 has a first linear portion 1221 extending obliquely towards the lower surface 13 away from the upper corner blade 121, and a first transition portion 1222 connected in a circular arc between the first linear portion 1221 and the upper corner blade 121, and the upper auxiliary cutting blade 123 also has a second linear portion 1231 extending obliquely towards the lower surface 13 away from the upper corner blade 121, and a second transition portion 1232 connected in a circular arc between the second linear portion 1231 and the upper corner blade 121. The oblique extension can correspondingly increase the length of the upper main cutting blade 122 and the upper auxiliary cutting blade 123, and the specific oblique angle can be flexibly set according to actual conditions.

[0096] The extension length of the upper main cutting edge 122 is greater than that of the upper minor cutting edge 123. As mentioned above, the sum of the extension lengths of the upper main cutting edge 122 and the upper minor cutting edge 123 substantially defines the side length of the cutting insert 1. In the case where the outer dimension of the insert is limited, the design can ensure that the upper main cutting edge 122 has sufficient length, thereby ensuring the machining efficiency. In other words, under the premise that the upper main cutting edge 122 has the same cutting length, the design can reduce the overall size of the cutting insert 1, which is beneficial to the substantial reduction of the material cost.

[0097] Referring back to Figure 1 and Figure 2 In the direction from the upper cutting edge 12 to the center hole 15, the upper surface 11 further comprises an upper rake surface 114 arranged along the upper cutting edge 12, an upper restraining surface 115 arranged around the center hole 15, and an upper transition surface 116 connected between the upper restraining surface 115 and the upper rake surface 114. The upper rake surface 114 is closer to the lower surface 13 as it is farther away from the upper cutting edge 12, and the upper restraining surface 115 is closer to the lower surface 13 than the upper rake surface 114.

[0098] The upper rake surface 114 defines the rake angle of the upper cutting edge 12, which can be reasonably set according to actual conditions. Referring to Figure 3 , corresponding to the upper main cutting edge 122 and the upper minor cutting edge 123, the upper rake surface 114 comprises an upper main rake surface 1142 along the upper main cutting edge 122 and an upper minor rake surface 1143 along the upper minor cutting edge 123. The upper main rake surface 1142 and the upper minor rake surface 1143 can be designed according to the requirements of the upper main cutting edge 122 and the upper minor cutting edge 123, respectively.

[0099] The upper restraining surface 115 is a plane perpendicular to the center axis L1, which is used to form a restraint with the shank 2 to maintain the position of the cutting insert 1 installed on the shank 2. Since the upper restraining surface 115 is closer to the lower surface 13 than the upper cutting edge 12, i.e., the upper restraining surface 115 is a concave structure compared to the upper cutting edge 12, a larger chip space can be formed between the upper cutting edge 12 and the upper restraining surface 115, which facilitates the discharge of the chips.

[0100] The upper transition surface 116 is a transition structure between the upper restraining surface 115 and the upper rake surface 114. In the direction from the upper rake surface 114 to the center hole 15, the upper transition surface 116 is closer to the lower surface 13 as it is farther away from the upper rake surface 114, and the "gap" between the upper cutting edge 12 and the upper restraining surface 115 can be further increased through the upper transition surface 116.

[0101] As mentioned earlier, when the cutting blade 1 is flipped up and down, the upper surface 11 and the lower surface 13 are interchangeable, and the structure of the lower surface 13 is actually the same as that of the upper surface 11.

[0102] Still refer to Figure 1 ,by Figure 1 Looking at the lower corner 131 located in the middle of the lower surface 13, the outer edge of the lower surface 13 includes a first lower edge 132, a second lower edge 133 intersecting with the first lower edge 132, and a lower corner 131 located at the intersection of the first lower edge 132 and the second lower edge 133. This lower corner 131 is vertically opposite to the upper corner 111 of the upper surface 11. The first lower edge 132 is located below the second upper edge 113, and the second lower edge 133 is located below the first upper edge 112.

[0103] The lower corner 131 is rounded and symmetrical to the upper corner 111. (See also...) Figure 3 Viewed from the top surface 11, the lower corner 131 intersects the upper corner 111, with a deflection angle between them. The endpoint Q1 where the lower corner 131 connects to the first lower edge 132 is farther from the central axis L1 than the endpoint P2 where the upper corner 111 connects to the second upper edge 113. The endpoint Q2 where the lower corner 131 connects to the second lower edge 133 is closer to the central axis L1 than the endpoint P1 where the upper corner 111 connects to the first upper edge 112. Endpoint Q2 is marked as... Figure 4 In Figure 3 It is not visible in the middle.

[0104] See Figure 1 The lower cutting edge 14, correspondingly located at the outer edge of the lower surface 13, includes a lower corner cutting edge 141 at the lower corner 131, a lower main cutting edge 142 at the first lower edge 132, and a lower secondary cutting edge 143 at the second lower edge 133. The lower corner cutting edge 141 is arc-shaped and perpendicular to the central axis L1. The extended shape of the lower corner cutting edge 141 is the same as the extended shape of the upper corner cutting edge 121, and the two are centrally symmetrical. The lower main cutting edge 142 and the lower secondary cutting edge 143 are located on both sides of the lower corner cutting edge 141 and are respectively connected to the two ends of the arc of the lower corner cutting edge 141.

[0105] Similar to the upper cutting edge 12, four lower cutting edges 14 are arranged rotationally symmetrically along the outer edge of the lower surface 13. Correspondingly, between two adjacent lower cutting edges 141, there is a lower main cutting edge 142 belonging to one lower cutting edge 14 and a lower secondary cutting edge 143 belonging to the other lower cutting edge 14. Above the lower main cutting edge 142, there is an upper secondary cutting edge 123, and above the lower secondary cutting edge 143, there is an upper main cutting edge 122. The upper main cutting edge 122 and the lower main cutting edge 142 are partially vertically opposite each other.

[0106] Preferably, the lower sub-cutting edge 143 is more biased towards the central axis L1 than the upper main cutting edge 122 above it, and vice versa, as shown in Figure 3 the upper sub-cutting edge 123 is also more biased towards the central axis L1 than the lower main cutting edge 142 below it, and the angle between the upper sub-cutting edge 123 and the lower main cutting edge 142 below it is also θ, i.e. the angle between the upper sub-cutting edge 123 and the extension line of the adjacent upper main cutting edge 122 as mentioned above. The angle between the lower sub-cutting edge 143 and the upper main cutting edge 122 above it is also the same angle θ.

[0107] The cutting insert 1 of the present embodiment is double-sided, and the relevant features of the lower cutting edge 14 are the same as those of the upper cutting edge 12, so that the same cutting performance can be achieved by using the cutting edges on different surfaces.

[0108] The other features of the lower surface 13 can be referred to the relevant description of the upper surface 11 above.

[0109] Still referring to Figure 1 , the peripheral surface 16 is rotationally symmetrical about the central axis L1, and comprises a corner side surface 161, a first side surface 162 and a second side surface 163 arranged on two sides of the corner side surface 161, a third side surface 164 arranged between the corner side surface 161 and the first side surface 162, and a fourth side surface 165 arranged between the corner side surface 161 and the second side surface 163. Preferably, the first side surface 162, the second side surface 163, the third side surface 164 and the fourth side surface 165 are all planar surfaces, and the first side surface 162 and the third side surface 164 can be connected by a transition surface (not numbered in the figure), and the second side surface 163 and the fourth side surface 165 can also be connected by a transition surface.

[0110] The corner side surface 161 connects the upper corner 111 of the upper surface 11 and the corresponding lower corner 131 of the lower surface 13, and is used to define the relief angle of the upper corner edge 121 and the lower corner edge 141.

[0111] As shown in Figure 6 , in any cross section between the upper surface 11 and the lower surface 13 perpendicular to the central axis L1, the intersection line between the corner side surface 161 and the cross section is in the shape of a circular arc, and has the same extension shape as the upper corner 111 and the lower corner 131. In combination with Figure 3 , the part of the corner side surface 161 close to the fourth side surface 165 gradually moves away from the central axis L1 in the direction from the upper surface 11 to the lower surface 13, while the part of the corner side surface 161 close to the third side surface 164, which is not shown in Figure 3 , gradually tilts towards the central axis L1 in the direction from the upper surface 11 to the lower surface 13.

[0112] In Figure 4Using the view direction as a reference, the corner side 161 is deflected from the upper right to the lower left. A vector view is performed using the line connecting endpoints P2 and Q1, as shown... Figure 5 As shown, endpoints P1 and Q2 do not coincide. This can be understood as follows: in the direction from the upper surface 11 to the lower surface 13, the corner side 161 is a curved surface formed by rotating and moving the arc defined by endpoints P1 and P2 (i.e., the upper corner 111) to the arc defined by endpoints Q2 and Q1 (i.e., the lower corner 131). Using this curved surface form, the range of rotation and movement is small, and the entire corner side 161 is smoothly connected without sharp or pointed intersecting edges. Therefore, sufficient strength of the cutting tool can be ensured, while preventing localized stress concentration during the cutting tool sintering process.

[0113] At the same time, the use of such a curved surface on the corner side 161 can better transition and connect the third side 164 and the fourth side 165 on both sides.

[0114] See Figure 1 and Figure 6 The third side surface 164 connects to the second lower edge 133 of the lower surface 13 and is connected to the lower secondary cutting edge 143, and tilts away from the central axis L1 as it moves away from the lower secondary cutting edge 143. Conversely, the third side surface 164 gradually tilts towards the central axis L1 in the direction from the upper surface 11 to the lower surface 13, and the trend is the same as that of the part of the corner side surface 161 near the third side surface 164. The transition between the corner side surface 161 and the third side surface 164 is smoother, improving stress distribution.

[0115] The third side surface 164 serves as the rear corner surface of the lower secondary cutting edge 143, defining the rear corner of the lower secondary cutting edge 143. Based on the inclined arrangement of the third side surface 164, the rear corner of the lower secondary cutting edge 143 is a negative angle greater than 90°.

[0116] The width of the third side 164 gradually decreases as it moves away from the lower secondary cutting edge 143. For example... Figure 4 As shown, the upper end point of the third side surface 164 is adjacent to the endpoint P1 where the upper corner 111 meets the first upper edge 112. Overall, the shape of the third side surface 164 is approximately triangular. With this design, the area occupied by the third side surface 164 in the entire outer peripheral surface 16 can be minimized while facilitating the chip removal of the lower secondary cutting edge 143.

[0117] Still refer to Figure 1 and Figure 6The fourth side surface 165 is centrally symmetrical to the third side surface 164, and is connected to the second upper edge 113 of the upper surface 11, connected to the upper sub cutting edge 123, and inclined away from the central axis L1 as it is away from the upper sub cutting edge 123. The fourth side surface 165 has the same variation trend as the portion of the corner side surface 161 close to the fourth side surface 165, and the transition between the corner side surface 161 and the third side surface 164 is smoother, improving the stress distribution.

[0118] The width of the fourth side surface 165 gradually decreases as it is away from the upper sub cutting edge 123. As shown in Figure 4 , the lower end of the fourth side surface 165 is adjacent to the junction end point Q1 of the lower corner 131 and the first lower edge 132, and the shape of the fourth side surface 165 as a whole is approximately an inverted triangle. Similarly, with this design, the area of the fourth side surface 165 in the entire peripheral surface 16 can be minimized while facilitating the chip removal of the upper sub cutting edge 123.

[0119] The fourth side surface 165 serves as the relief surface of the upper sub cutting edge 123, and defines the relief angle of the upper sub cutting edge 123. According to the inclined arrangement of the fourth side surface 165, the relief angle of the upper sub cutting edge 123 is a greater-than-90° relief angle.

[0120] Referring to Figure 1 , the first side surface 162 is connected to the first upper edge 112, connected to the upper main cutting edge 122, and parallel to the central axis L1. The first side surface 162 serves as the relief surface of the upper main cutting edge 122, and defines the relief angle of the upper main cutting edge 122. According to the structure of the first side surface 162, the relief angle of the upper main cutting edge 122 is a negative angle of 90°.

[0121] The second side surface 163 is connected to the first lower edge 132, connected to the lower main cutting edge 142, and parallel to the central axis L1. The second side surface 163 serves as the relief surface of the lower main cutting edge 142, and defines the relief angle of the lower main cutting edge 142. According to the structure of the second side surface 163, the relief angle of the lower main cutting edge 142 is a negative angle of 90°.

[0122] The first side surface 162 and the second side surface 163 are rotationally symmetrical to the central axis L1. In this embodiment, the lower end of the first side surface 162 is connected to another lower main cutting edge 142 of the lower surface 13, as viewed in the direction of the view Figure 1 , that is, the lower end of the first side surface 162 is connected to the rightmost lower main cutting edge 142 of the lower surface 13, and the first side surface 162 also serves as the relief surface of the rightmost lower main cutting edge 142. The upper end of the second side surface 163 is also connected to another upper main cutting edge 122 of the upper surface 11, as viewed in the direction of the view Figure 1viewed from the view direction of the upper surface 11, the second side surface 163 also serves as a clearance surface of the leftmost upper main cutting edge 122.

[0123] If the structure between two adjacent corner side surfaces 161 is considered, between the two adjacent corner side surfaces 161, there is a third side surface 164 adjacent to one of the corner side surfaces 161, a fourth side surface 165 adjacent to the other corner side surface 161, a first side surface 162 connected to the third side surface 164, and a second side surface 163 connected to the fourth side surface 165. In the special structure of the present embodiment, the first side surface 162 and the second side surface 163 are coplanar. In a popular way: between two adjacent corners of the cutting insert 1, the upper main cutting edge 122 of the upper surface 11 and the lower main cutting edge 142 of the lower surface 13 are connected by the same side surface. According to this design, the peripheral shape of the cutting insert 1 can be fully utilized to design multiple cutting edges, improving the utilization rate of the cutting insert 1, and facilitating the miniaturization of the cutting insert 1 while ensuring the cutting length.

[0124] The first side surface 162 and the second side surface 163 are both parallel to the center axis L1, and when the cutting tool is index-mounted, the first side surface 162 or the second side surface 163 not involved in cutting and away from the workpiece serves as a restraint surface to contact the shank, thereby improving the restraint effect through plane contact. In addition, according to the foregoing description, since the third side surface 164 and the fourth side surface 165 both adopt the structure of gradually decreasing width, the first side surface 162 and the second side surface 163 can occupy most of the overall peripheral surface 16, and when serving as a restraint surface, the contact area can be increased, thereby also improving the restraint effect.

[0125] In combination with the foregoing description, please refer to Figures 7 to 14 For an upper cutting edge 12, the fourth side surface 165 defines the clearance angle of the upper minor cutting edge 123, the upper minor rake surface 1143 defines the rake angle of the upper minor cutting edge 123, the corner side surface 161 defines the clearance angle of the upper corner cutting edge 121, the first side surface 162 defines the clearance angle of the upper main cutting edge 122, and the upper main rake surface 1142 defines the rake angle of the upper main cutting edge 122.

[0126] Specifically, Figure 8 and Figure 9 respectively show sectional views of two different positions of the upper minor cutting edge 123.

[0127] Since the fourth side surface 165 is a plane, Figure 8 the angle a1 of the fourth side surface 165 relative to the base surface in the sectional view of the upper minor cutting edge 123 in FIG. 8 is equal to the angle a2 of the fourth side surface 165 relative to the base surface in the sectional view of the upper minor cutting edge 123 in FIG. 9. Figure 9The angle b1 of the fourth side surface 165 relative to the base surface is the same, wherein the base surface is a virtual plane perpendicular to the center axis L1, which is not shown in the figure. The angle a1 and the angle b1 are the negative angles of the upper sub cutting edge 123, which are greater than 90°, due to the inclined arrangement of the fourth side surface 165 relative to the center axis L1. Thus, the strength of the cutting resistance at the upper sub cutting edge 123 can be ensured, and the durability of the upper sub cutting edge 123 can be ensured.

[0128] Figure 8 The angle a2 of the upper sub rake surface 1143 relative to the base surface and Figure 9 The angle b2 of the upper sub rake surface 1143 relative to the base surface is the rake angle of the upper sub cutting edge 123 at two different positions, respectively. The angle a2 and the angle b2 can be the same or different, and can be flexibly set according to actual needs.

[0129] Under the condition of the same blade thickness, that is, under the condition of ensuring the included angle between the upper sub rake surface 1143 and the fourth side surface 165, since the negative angle of the upper sub cutting edge 123, compared with the positive angle, the upper sub rake surface 1143 can deviate from the base surface more, that is, the rake angle of the upper sub rake surface 1143 relative to the base surface is increased. The greater the rake angle, the sharper the blade, and thus the sharpness of the upper sub cutting edge 123 can be improved, so that the machined surface formed by the upper sub cutting edge 123 is smoother.

[0130] Figure 13 The cross-sectional view of the first transition portion 1222 of the upper main cutting edge 122 is shown, Figure 14 The cross-sectional view of the first linear portion 1221 of the upper main cutting edge 122 is shown.

[0131] Figure 13 The angle f1 of the first side surface 162 relative to the base surface and Figure 14 The angle g1 of the first side surface 162 relative to the base surface is 90°. That is, the negative angle of the first transition portion 1222 and the first linear portion 1221 of the upper main cutting edge 122 is 90°. The negative angle of the upper main cutting edge 122 is smaller than the negative angle of the upper sub cutting edge 123.

[0132] Figure 13 The angle f2 of the upper main rake surface 1142 relative to the base surface is the rake angle of the first transition portion 1222, Figure 14 The angle g2 of the upper main rake surface 1142 relative to the base surface is the rake angle of the first linear portion 1221. The angle f2 and the angle g2 can be the same or different, and can be flexibly set according to actual needs.

[0133] As mentioned above, the upper sub-rake surface 1143 is more inclined to the lower surface 13 than the upper main-rake surface 1142, i.e. the upper sub-rake surface 1143 defines an upper sub-cutting edge 123 with a larger rake angle than the upper main-rake surface 1142 defines an upper main-cutting edge 122.

[0134] By properly setting the inclination angles of the fourth side surface 165, the upper sub-rake surface 1143 and the upper main-rake surface 1142, the thickness of the insert at the upper main-cutting edge 122 and the upper sub-cutting edge 123 can be made uniform.

[0135] In addition, in combination with Figure 13 and Figure 1 It can also be seen that at the first transition portion 1222, the first side surface 162 is connected with a third side surface 164 which is inclined to the central axis L1 compared to the first side surface 162.

[0136] Figure 10 Fig. 6 shows a cross-sectional view of the upper corner cutting edge 121 at a portion inclined to the upper sub-cutting edge 123, Figure 11 Fig. 7 shows a cross-sectional view of the upper corner cutting edge 121 at a central position, Figure 12 Fig. 8 shows a cross-sectional view of the upper corner cutting edge 121 at a portion inclined to the upper main-cutting edge 122. The angle of the corner side surface 161 with respect to the base surface is the relief angle of the upper corner cutting edge 121.

[0137] As mentioned above, since the corner side surface 161 is a deflected curved surface, the relief angle of the upper corner cutting edge 121 varies at different positions, as shown in Figure 10 the relief angle c at the portion inclined to the upper sub-cutting edge 123 is a negative angle greater than 90°, as shown in Figure 11 the relief angle d at the central position is a negative angle close to 90°, as shown in Figure 12 the relief angle e at the portion inclined to the upper main-cutting edge 122 is a positive angle less than 90°.

[0138] Referring to Figures 15 to 18 , the present embodiment provides a tool having the above cutting insert 1. The tool is a face milling cutter, and the tool shank 2 is a face milling cutter head. During machining, the tool shank 2 is installed on a machine tool (not shown in the drawings) and rotates around the rotation axis L2 to drive the cutting insert 1 to machine a workpiece 4.

[0139] In combination with Figure 15 and Figure 17 , the lower end of the tool shank 2 is provided with a plurality of installation grooves 21 circumferentially arranged to respectively install the plurality of cutting inserts 1. The structure and shape of the installation grooves 21 are set according to the structure and shape of the cutting inserts 1. The cutting inserts 1 are installed in the installation grooves 21 and fastened by the fasteners 3.

[0140] It is particularly pointed out that, according to the structure of the cutting insert 1 as described above, the seat surface 211 of the mounting groove 21 is arranged as a plane for cooperating with the upper restraining surface 115 of the upper surface 11 or the lower restraining surface of the lower surface 13 of the cutting insert 1; the side surface 212 of the mounting groove 21 is arranged as a plane for cooperating with the first side surface 162 or the second side surface 163 of the cutting insert 1. With the plane restraining cooperation, the structure of the mounting groove 21 can be simplified and the restraining effect can be improved.

[0141] As Figure 17 , the seat surface 211 is generally inclined forward in the rotation direction relative to the rotation axis L2, and the seat surface 211 has an included angle β with the rotation axis L2. In addition, the side surface 212 of the mounting groove 21 also has a certain deflection angle relative to the rotation axis L2 in the radial direction of the shank 2. Thus, as shown in Figure 16 and Figure 18 , the cutting insert 1 is mounted in the mounting groove 21 and is inclined relative to the rotation axis L2 so that one of the upper cutting edges 12 or the lower cutting edges 14 protrudes from the outer periphery and the lower side of the shank 2 to machine the workpiece 4.

[0142] In combination Figure 16 and Figure 18 , taking the example of one of the upper cutting edges 12 participating in cutting, the upper main cutting edge 122 machines the side end surface 41 of the workpiece 4, at this time, the first side surface 162 and the third side surface 164 are opposite to the side end surface 41 of the workpiece 4, since the third side surface 164 is inclined away from the central axis L1 with the distance from the lower minor cutting edge 143, accordingly, as referenced by the first side surface 162, the third side surface 164 is more inclined to the central axis L1 (for details, please refer to Figure 1 and Figure 13 ), therefore, the third side surface 164 is less likely to contact the side end surface 41 of the workpiece 4 than the first side surface 162, and thus the presence of the lower cutting edge 14 does not affect the quality of the surface machined by the upper cutting edge 12.

[0143] Similarly, as seen in the case of one of the lower cutting edges 14 participating in cutting, the lower main cutting edge 142 machines the side end surface 41 of the workpiece 4, the second side surface 163 and the fourth side surface 165 are opposite to the side end surface 41 of the workpiece 4, since the fourth side surface 165 is inclined away from the central axis L1 with the distance from the upper minor cutting edge 123, therefore, the fourth side surface 165 is less likely to contact the side end surface 41 of the workpiece 4 than the second side surface 163, and thus the presence of the upper cutting edge 12 does not affect the quality of the surface machined by the lower cutting edge 14.

[0144] In summary, the upper cutting edges 12 and the lower cutting edges 14 of the cutting insert 1 do not affect each other in machining, and for the cutting insert 1 used on both sides, the quality of the machined surface can be improved.

[0145] Further, referring to the foregoing description of the cutting insert 1, the upper major cutting edge 122 and the lower minor cutting edge 143 opposite to each other have an included angle θ, and the lower minor cutting edge 143 is more deviated to the central axis L1 than the upper major cutting edge 122. Similarly, the lower major cutting edge 142 and the upper minor cutting edge 123 opposite to each other have an included angle θ, and the upper minor cutting edge 123 is more deviated to the central axis L1 than the lower major cutting edge 142. The existence of the included angle θ can cooperate with the axial inclination angle β of the cutting insert 1 on the shank 2 and the radial inclination angle not shown to adjust the machining locus of the upper minor cutting edge 123 or the lower minor cutting edge 143 to be parallel to the bottom surface 42 of the workpiece 4, thereby ensuring the machining precision of the bottom surface 42 of the workpiece 4 machined by the upper minor cutting edge 123 or the lower minor cutting edge 143.

[0146] The above embodiments are described by taking the cutting insert 1 with a rectangular block structure as an example. The cutting insert 1 has a total of eight cutting edges and can be indexed to eight directions for machining, so the utilization rate of the cutting insert 1 is high. In other embodiments, the cutting insert 1 can also have other numbers of cutting edges, and the shape of the cutting insert 1 can be adaptively adjusted.

[0147] For example Figure 19 A cutting insert 5 with six cutting edges of another embodiment is shown. The cutting insert 5 is also a double-sided insert, which has upper and lower opposite upper and lower surfaces 51, 53 and an outer peripheral surface 56 between the upper and lower surfaces 51, 53. An upper cutting edge 52 is arranged on the outer edge of the upper surface 51, and a lower cutting edge 54 is arranged on the outer edge of the lower surface 53, which can be used for cutting machining respectively. The cutting insert 5 also has a central hole 55 penetrating the upper and lower surfaces 51, 53. The outer edges of the upper and lower surfaces 51, 53 are both central rotationally symmetrical figures, and the centers of the upper and lower surfaces 51, 53 are both located on the central axis L5 of the central hole 55.

[0148] The outer edge of the upper surface 51 has a first upper edge 512, a second upper edge 513 intersecting the first upper edge 512, and an upper corner 511 located at the intersection of the first upper edge 512 and the second upper edge 513.

[0149] Taking the first upper edge 512, the upper corner 511 and the second upper edge 513 as a unit, the entire outer edge of the upper surface 51 is composed of three such units connected end to end, and the three units are rotationally symmetrical about the central axis L5.

[0150] The upper cutting edge 52 includes an upper corner edge 521 located at the upper corner 511, an upper major cutting edge 522 located at the first upper edge 512, and an upper minor cutting edge 523 located at the second upper edge 513. Among them, the upper minor cutting edge 523 only extends along a part of the length of the second upper edge 513 close to the upper corner 511, and the other part of the second upper edge 513 is not provided with a cutting edge.

[0151] The outer edge of the lower surface 53 comprises a first lower edge 532, a second lower edge 533 intersecting the first lower edge 532, and a lower corner 531 located at the intersection of the first lower edge 532 and the second lower edge 533.

[0152] The lower cutting edge 54 comprises a lower corner edge 541 located at the lower corner 531, a lower main cutting edge 542 located at the first lower edge 532, and a lower sub-cutting edge 543 located at the second lower edge 533. Similarly, the lower sub-cutting edge 543 only extends along a portion of the second lower edge 533 close to the lower corner 531, and the other portion of the second lower edge 533 is not provided with a cutting edge.

[0153] The outer peripheral surface 56 comprises a corner side surface 561 connecting the upper corner 511 and the lower corner 531, a first side surface 562 and a second side surface 563 arranged on both sides of the corner side surface 561, a third side surface 564 located between the corner side surface 561 and the first side surface 562, and a fourth side surface 565 located between the corner side surface 561 and the second side surface 563.

[0154] The first side surface 562 connects the upper and lower opposite first upper edge 512 and the second lower edge 533, is connected with the upper main cutting edge 522, and is parallel to the center axis L5.

[0155] The second side surface 563 connects the upper and lower opposite first lower edge 532 and the second upper edge 513, is connected with the lower main cutting edge 542, and is parallel to the center axis L5.

[0156] The third side surface 564 connects the second lower edge 533, is connected with the lower sub-cutting edge 543, and tilts away from the center axis L5 as it moves away from the lower sub-cutting edge 543.

[0157] The fourth side surface 565 connects the second upper edge 513, is connected with the upper sub-cutting edge 523, and tilts away from the center axis L5 as it moves away from the upper sub-cutting edge 523.

[0158] In this embodiment, between the two adjacent corner side surfaces 561, the first side surface 562 and the second side surface 563 are not coplanar, the first side surface 562 and the second side surface 563 are circumferentially connected, and form an obtuse angle.

[0159] Similarly, in this embodiment, due to the arrangement of the third side surface 564 and the fourth side surface 565 tilting away from the center axis L5, the upper cutting edge 52 and the lower cutting edge 54 do not affect each other's machined surface, improving the quality of the machined surface.

[0160] Figure 19 In this embodiment, the upper surface 51 and the lower surface 53 are simplified as planes, and in the actual structure, the upper surface 51 and the lower surface 53 can refer to the above description of the upper surface 51 and the lower surface 53. Figure 1The illustrated structure provides a front corner face, a transition face, and an extension face.

[0161] While the application has been described with reference to several exemplary embodiments, it is to be understood that the use of other words or terms such as "preferably," "according to an embodiment," and "in one embodiment" is intended to not limit the specification or claims unless other wise explicitly so defined by the patentee. Therefore, the foregoing description and drawings are by way of example only, and without limitation to the scope of the application, as defined in the appended claims.

Claims

1. A cutting blade, characterized in that, have: The upper surface has: First upper edge; The second upper edge intersects with the first upper edge; and The upper corner is located at the intersection of the first upper edge and the second upper edge; The upper cutting edge, located at the outer edge of the upper surface, includes: The upper corner blade is located at the upper corner; The upper main cutting edge is located on the first upper edge and connects to the upper corner cutting edge; and The upper secondary cutting edge is located on the second upper edge and is connected to the upper corner cutting edge; The lower surface has: The first lower edge is located below the second upper edge; The second lower edge intersects the first lower edge and is located below the first upper edge; and The lower corner is located at the intersection of the first lower edge and the second lower edge; The lower cutting edge, located at the outer edge of the lower surface, includes: The lower corner blade is located at the lower corner; The lower main cutting edge is located on the first lower edge and connects to the lower corner cutting edge; and The lower secondary cutting edge is located on the second lower edge and is connected to the lower corner cutting edge; A central axis extends through the center of the upper surface and the center of the lower surface; and The outer peripheral surface, located between the upper surface and the lower surface, includes: The side of the corner connects the upper corner and the lower corner; The first side surface is connected to the first upper edge, connected to the upper main cutting edge, and parallel to the central axis; The second side is connected to the first lower edge, connected to the lower main cutting edge, and parallel to the central axis; The third side, located between the corner side and the first side, connects to the second lower edge, is connected to the lower secondary cutting edge, and tilts away from the central axis as it moves away from the lower secondary cutting edge; and The fourth side, located between the corner side and the second side, connects to the second upper edge, is connected to the upper secondary cutting edge, and tilts away from the central axis as it moves away from the upper secondary cutting edge. The width of the third side gradually decreases as it moves away from the lower secondary cutting edge; the width of the fourth side gradually decreases as it moves away from the upper secondary cutting edge. The upper endpoint of the third side is adjacent to the junction of the upper corner and the first upper edge; the lower endpoint of the fourth side is adjacent to the junction of the lower corner and the first lower edge. The portion of the corner side near the fourth side gradually moves away from the central axis in the direction from the upper surface to the lower surface, while the portion of the corner side near the third side gradually tilts towards the central axis in the direction from the upper surface to the lower surface.

2. The cutting blade according to claim 1, characterized in that, The upper main cutting edge and the lower secondary cutting edge, which are opposite each other, have an included angle θ, and the lower secondary cutting edge is more biased toward the central axis than the upper main cutting edge.

3. The cutting blade according to claim 2, characterized in that, 0 < θ ≤ 10°.

4. The cutting blade according to claim 1, characterized in that, The extension length of the upper main cutting edge is greater than the extension length of the upper secondary cutting edge; the extension length of the lower main cutting edge is greater than the extension length of the lower secondary cutting edge.

5. The cutting blade according to claim 1, characterized in that, The first side, the second side, the third side, and the fourth side are all planar.

6. The cutting blade according to claim 1, characterized in that, The upper corner and the lower corner are centrally symmetrical; when viewed from the upper surface, the endpoint of the lower corner that connects to the first lower edge is farther from the central axis than the endpoint of the upper corner that connects to the second upper edge, and the endpoint of the lower corner that connects to the second lower edge is closer to the central axis than the endpoint of the upper corner that connects to the first upper edge.

7. The cutting blade according to claim 6, characterized in that, Both the upper corner and the lower corner extend in an arc shape and are perpendicular to the central axis; on any cross-section between the upper surface and the lower surface that is perpendicular to the central axis, the extended shape of the side of the corner is the same as the extended shape of the upper corner and the lower corner.

8. The cutting insert according to any one of claims 1-7, characterized in that, The upper surface also includes an upper front corner face disposed along the upper cutting edge, which moves closer to the lower surface as it moves away from the upper cutting edge in the direction toward the central axis.

9. The cutting blade according to claim 8, characterized in that, The upper surface also includes a restraint surface disposed around and perpendicular to the central axis, the restraint surface being closer to the lower surface than the upper cutting edge.

10. A cutting tool, characterized in that, Includes a tool holder and a cutting insert as described in any one of claims 1-9 mounted on the tool holder.

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