CN117042904A - Cutting insert and cutting tool - Google Patents

Abstract

A cutting insert (1) has an upper surface (11) opposed vertically, a lower surface (13), an outer peripheral surface (16) located between the upper and lower surfaces, an upper cutting edge (12) located at an outer edge of the upper surface (11), a lower cutting edge (14) located at an outer edge of the lower surface (13), and a central axis (L5) passing through the upper and lower surfaces; the upper cutting edge (12) comprises an upper corner edge (121), an upper main cutting edge (122) and an upper auxiliary cutting edge (123), and the lower cutting edge (14) comprises a lower corner edge (141), a lower main cutting edge (142) and a lower auxiliary cutting edge (143); the outer peripheral surface (16) includes corner side surfaces (161), a first side surface (162), a second side surface (163), a third side surface (164), and a fourth side surface (165); the first side surface (162) is connected with the upper main cutting edge (122), the second side surface (163) is connected with the lower main cutting edge (142), and the first side surface (162) and the second side surface (163) are parallel to the central axis (L5); the third side surface (164) is connected to the lower sub-cutting edge (143) and is inclined away from the central axis (L5) as it is away from the lower sub-cutting edge (143); the fourth side surface (165) is connected to the upper sub-cutting edge (123) and is inclined away from the central axis (L5) as it goes away from the upper sub-cutting edge (123). The present invention can improve the quality of the machined surface of a double-sided cutting insert. A cutting tool is also provided.

Description

Cutting insert and cutting tool Technical Field

The invention relates to the field of cutters, in particular to a cutting blade and a cutting cutter.

Background

Chinese patent No. CN103071821B discloses an indexable cutting insert comprising: a plurality of cutting corners having a continuously curved cutting edge thereon; a flank on each side of each cutting corner, wherein one flank has a positive relief angle with respect to the central axis of the passage opening and the other flank has a negative relief angle with respect to the central axis of the passage opening. Each cutting corner has two part surfaces which abut each other along a line extending parallel to the central axis of the passage opening.

In the solution disclosed in this patent, both the upper and lower surfaces of the insert form cutting edges, so that a double-sided use is possible. However, in the insert structure disclosed in this patent, when machining is performed using the cutting edge on the upper surface side, the relief surface of the cutting edge located on the lower surface side is likely to contact the workpiece to be cut. 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 tilted forward when the insert is mounted on the holder, and since the side surface is tilted, the minor cutting edge on the lower surface side has a positive relief surface, and the relief surface along the minor cutting edge is easily located at the rear side in the rotation direction, and contacts the machined surface cut by the major cutting edge on the upper surface side, thereby affecting the surface quality of the machined surface.

Disclosure of Invention

It is an object of the present invention to provide a cutting insert to improve the quality of the machined surface of a double-sided use cutting insert.

Another object of the present invention is to provide a cutting tool having the above cutting insert.

In order to solve the technical problems, the invention adopts the following technical scheme:

according to one aspect of the present invention, there is provided a cutting insert having:

an upper surface having:

a first upper edge;

a second upper edge intersecting the first upper edge; and

An upper corner located at the intersection of the first upper edge and the second upper edge;

an upper cutting edge located at an outer edge of the upper surface, comprising:

an upper corner edge located at the upper corner;

the upper main cutting edge is positioned at the first upper edge and is connected with the upper corner edge; and

The upper auxiliary cutting edge is positioned at the second upper edge and is connected with the upper corner edge;

a lower surface having:

a first lower edge located below the second upper edge;

a second lower edge intersecting the first lower edge and located below the first upper edge; and

A lower corner located at the intersection of the first lower edge and the second lower edge;

a lower cutting edge located at an outer edge of the lower surface, comprising:

a lower corner edge located at the lower corner;

the lower main cutting edge is positioned at the first lower edge and is connected with the lower corner edge; and

The lower auxiliary cutting edge is positioned at the second lower edge and is connected with the lower corner edge;

a central axis passing through the center of the upper surface and the center of the lower surface; and

An outer peripheral surface located between the upper surface and the lower surface, comprising:

a corner side connecting the upper corner and the lower corner;

the first side surface is connected with the first upper edge, is connected with the upper main cutting edge and is parallel to the central shaft;

a second side surface connected to the first lower edge, connected to the lower main cutting edge, and parallel to the central axis;

a third side surface located between the corner side surface and the first side surface, connecting the second lower edge, connected to the lower sub-cutting edge, and inclined away from the central axis as it is away from the lower sub-cutting edge; and

And a fourth side surface which is positioned between the corner side surface and the second side surface, is connected with the second upper edge, is connected with the upper auxiliary cutting edge, and is inclined away from the central shaft along with being far away from the upper auxiliary cutting edge.

In some embodiments, the upper major cutting edge and the lower minor cutting edge are opposite one another up and down with an angle θ therebetween, and the lower minor cutting edge is more biased toward the central axis than the upper major cutting edge.

In some embodiments, 0 < θ+.10°.

In some embodiments, the upper primary cutting edge has an extension greater than the extension of the upper secondary cutting edge; the extension length of the lower main cutting edge is greater than the extension length of the lower auxiliary cutting edge.

In some embodiments, the first side, the second side, the third side, and the fourth side are all planar.

In some embodiments, the upper corner and the lower corner are centrally symmetrical; the end point of the lower corner that meets the first lower edge is farther from the central axis than the end point of the upper corner that meets the second upper edge when viewed from above the upper surface, and the end point of the lower corner that meets the second lower edge is closer to the central axis than the end point of the upper corner that meets the first upper edge.

In some embodiments, the upper corner and the lower corner each extend in an arc shape and are each perpendicular to the central axis; the extension shape of the corner side surface is the same as the extension shape of the upper corner and the lower corner on any section perpendicular to the central axis between the upper surface and the lower surface.

In some embodiments, the width of the third side surface gradually decreases away from the lower minor cutting edge; the width of the fourth side surface gradually decreases with the upper auxiliary cutting edge.

In some embodiments, an upper end point of the third side surface abuts to a junction of the upper corner and the first upper edge; the lower end point of the fourth side surface is adjacent to the junction of the lower corner and the first lower edge.

In some embodiments, the upper surface further comprises an upper rake surface disposed along the upper cutting edge, the upper rake surface being closer to the lower surface as it is farther from the upper cutting edge in a direction toward the central axis.

In some embodiments, the upper surface further includes a constrained surface disposed about and perpendicular to the central axis, the constrained surface being closer to the lower surface than the upper cutting edge.

According to another aspect of the present invention, there is provided a cutting tool comprising a shank and a cutting insert as described above mounted on the shank.

According to the technical scheme, the invention has at least the following advantages and positive effects: the cutting blade is provided with the upper cutting edge on the upper surface and the lower cutting edge on the lower surface, and double-sided use is realized through the upper cutting edge and the lower cutting edge. When the upper cutting edge is used for cutting a workpiece, the upper main cutting edge of the upper cutting edge is used for cutting the side end face of the workpiece, the first side face and the third side face of the outer peripheral face the side end face of the workpiece, and the third side face is inclined away from the central shaft along with being away from the lower auxiliary cutting edge, so that the third side face is less prone to contact with the side end face of the workpiece than the first side face, and therefore the quality of the surface processed by the upper cutting edge cannot be affected by the existence of the lower 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, and the fourth side surface is inclined away from the center axis as being away from the upper auxiliary cutting edge, so that the fourth side surface is less likely to contact the side end surface of the workpiece than the second side surface, and the quality of the surface processed by the lower cutting edge is not affected by the presence of the upper cutting edge. In combination, the upper and lower cutting edges of the cutting insert do not affect the machining of each other, and for a double-sided cutting insert, the quality of the machined surface can be improved.

Drawings

Fig. 1 is a schematic view showing a structure of a cutting insert according to an embodiment of the present invention from a perspective.

Fig. 2 is a front view of the cutting insert of fig. 1.

Fig. 3 is a partial enlarged view at K in fig. 2.

Fig. 4 is an M-direction view in fig. 2.

Fig. 5 is an N-directional view of fig. 4, with only one of the corner positions shown partially enlarged.

Fig. 6 is a partial enlarged view at J in fig. 1.

Fig. 7 is also a partial enlarged view at K in fig. 2.

Fig. 8 is a cross-sectional view A-A of fig. 7.

Fig. 9 is a sectional view of B-B in fig. 7.

Fig. 10 is a cross-sectional view of C-C in fig. 7.

Fig. 11 is a sectional view D-D of fig. 7.

Fig. 12 is a sectional view of E-E of fig. 7.

Fig. 13 is a cross-sectional view of F-F in fig. 7.

Fig. 14 is a sectional view of G-G in fig. 7.

Fig. 15 is a schematic view of a cutting tool incorporating the cutting insert of fig. 1.

Fig. 16 is a partial enlarged view at T in fig. 15.

Fig. 17 is a schematic view of the structure of fig. 16 with the cutting insert removed.

Fig. 18 is a schematic view of fig. 15 with a partial enlargement at V and opposite to a workpiece to be cut.

Fig. 19 is a schematic view of a cutting insert according to another embodiment of the present invention.

The reference numerals are explained as follows:

1. a cutting insert;

11. an upper surface; 111. an upper corner; 112. a first upper edge; 113. a second upper edge; 114. an upper front corner surface; 1142. an upper main front corner face; 1143. an upper minor anterior horn surface; 115. an upper confinement surface; 116. an upper transition surface;

12. an upper cutting edge; 121. an upper corner edge; 122. an upper main cutting edge; 1221. a first straight line portion; 1222. a first transition portion; 123. an upper auxiliary cutting edge; 1231. a second straight line portion; 1232. a second transition portion;

13. a lower surface; 131. a lower corner; 132. a first lower edge; 133. a second lower edge;

14. a lower cutting edge; 141. a lower corner edge; 142. a lower main cutting edge; 143. a lower auxiliary cutting edge;

15. a central bore; l1, a central axis;

16. an outer peripheral surface; 161. corner sides; 162. a first side; 163. a second side; 164. a third side; 165. a fourth side;

2. a knife handle; 21. a mounting groove; 211. a seat surface; 212. a side surface; l2, a rotation shaft;

3. a fastener;

4. a workpiece; 41. a side end face; 42. a bottom surface;

5. a cutting insert;

51. an upper surface; 511. an upper corner; 512. a first upper edge; 513. a second upper edge;

52. an upper cutting edge; 521. an upper corner edge; 522. an upper main cutting edge; 523. an upper auxiliary cutting edge;

53. a lower surface; 531. a lower corner; 532. a first lower edge; 533. a second lower edge;

54. a lower cutting edge; 541. a lower corner edge; 542. a lower main cutting edge; 543. a lower auxiliary cutting edge;

55. a central bore; l5, central axis;

56. an outer peripheral surface; 561. corner sides; 562. a first side; 563. a second side; 564. a third side; 565. and a fourth side.

Detailed Description

Exemplary embodiments that embody features and advantages of the present invention will be described in detail in the following description. It will be understood that the invention is capable of various modifications in various embodiments, all without departing from the scope of the invention, and that the description and illustrations herein are intended to be by way of illustration only and not to be construed as limiting the invention.

The invention provides a cutting insert and a tool having the same, the tool comprising a shank for mounting the cutting insert.

Fig. 1 to 14 illustrate schematic views of a cutting insert 1 according to an embodiment of the present invention, and fig. 15 illustrates schematic views of the cutting insert 1 mounted on a shank 2.

Referring first to fig. 1-4, the present embodiment provides an indexable and double-sided cutting insert 1.

The cutting insert 1 has an upper surface 11, a lower surface 13, which are vertically opposed, and an outer peripheral surface 16 located between the upper surface 11 and the lower surface 13. An upper cutting edge 12 is provided at the outer edge of the upper surface 11, and a lower cutting edge 14 is provided at the outer edge of the lower surface 13, and cutting processing can be performed by the upper cutting edge 12 and the lower cutting edge 14, respectively. The cutting insert 1 also has a central bore 15 through the upper and lower surfaces 11, 13, the central bore 15 being for passing a fastener 3 therethrough for mounting the cutting insert 1 to the shank 2 (as shown in fig. 15). The outer edges of the upper surface 11 and the lower surface 13 are rotationally symmetrical, and the center of the upper surface 11 and the center of the lower surface 13 are located on the central axis L1 of the central hole 15.

Here, "upper" and "lower" are defined manually for convenience of description, and in practice, the upper surface 11 and the lower surface 13 may be interchanged by turning the cutting insert 1 upside down.

The upper surface 11 will be described in detail first.

In this embodiment, the upper surface 11 has a substantially square-like shape, and the outer edge of the upper surface 11 has four upper corners 111 and upper edges respectively connecting the upper corners 111.

The outer edge of the upper surface 11 comprises, seen in fig. 1 in the position of the upper corner 111 in the intermediate position, a first upper edge 112, a second upper edge 113 intersecting the first upper edge 112, and an upper corner 111 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 are respectively connected with two arc ends of the upper corner 111.

The first upper edge 112, the upper corner 111 and the second upper edge 113 are formed as a unit, and the outer edge of the entire upper surface 11 is formed by four such units connected end to end, the four units being rotationally symmetrical about the central axis L1.

The upper cutting edge 12, which is correspondingly disposed at the outer edge of the upper surface 11, includes an upper corner edge 121 at the upper corner 111, an upper major cutting edge 122 at the first upper edge 112, and an upper minor cutting edge 123 at the second upper edge 113. The upper corner edge 121 extends in an arc shape and is perpendicular to the central axis L1. The upper main cutting edge 122 and the upper sub cutting edge 123 are respectively arranged on both sides of the upper corner edge 121 and are respectively connected to both ends of the circular arc of the upper corner edge 121.

In the cutting process, a workpiece is machined, for example, into a right angle surface by a combination of one upper corner edge 121, and one upper main cutting edge 122 and one upper sub cutting edge 123 connected thereto.

The four upper cutting edges 12 are rotationally symmetrically disposed along the outer edge of the upper surface 11, and the four upper cutting edges 12 can be respectively adjusted to a cutting operation state by rotating the cutting insert 1 to adjust the mounting position of the cutting insert 1 with respect to the holder 2.

Referring to fig. 2, the end of the upper main cutting edge 122 of each upper cutting edge 12 remote from the upper corner edge 121 is contiguous with the end of the upper sub cutting edge 123 of the other upper cutting edge 12 remote from the upper corner edge 121, that is, there is one upper main cutting edge 122 and one upper sub cutting edge 123 between two adjacent upper corner edges 121. In the present embodiment, the upper surface 11 has a substantially square structure, and one upper main cutting edge 122 and one upper sub cutting edge 123 between two adjacent upper corner edges 121 form one side of the square, but the side is not a straight line, and the upper sub cutting edge 123 is deviated in the direction of the central axis L1 away from the upper main cutting edge 122. As shown in FIG. 3, the upper minor cutting edge 123 forms an angle θ with the extension of the upper major cutting edge 122, and in some embodiments, 0 < θ+.10°.

Preferably, the upper main cutting edge 122 extends in one plane, and the upper auxiliary cutting edge 123 extends in the other plane, so that the machined surfaces machined by the upper main cutting edge 122 and the upper auxiliary cutting edge 123 can form a plane, and the flatness of the machined surfaces and the angle precision between the two machined surfaces are ensured.

Referring to fig. 3 and 4, in the present embodiment, the upper main cutting edge 122 has a first straight line portion 1221 extending obliquely toward the lower surface 13 away from the upper corner edge 121 and a first transition portion 1222 connected between the first straight line portion 1221 and the upper corner edge 121 in a circular arc transition, and the upper sub cutting edge 123 also has a second straight line portion 1231 extending obliquely toward the lower surface 13 away from the upper corner edge 121 and a second transition portion 1232 connected between the second straight line portion 1231 and the upper corner edge 121 in a circular arc transition. The length of the upper main cutting edge 122 and the length of the upper auxiliary cutting edge 123 can be correspondingly increased by adopting an inclined extension mode, and the specific inclined angle can be flexibly set according to actual conditions.

The extension length of the upper main cutting edge 122 is greater than the extension length of the upper sub cutting edge 123. As described above, the sum of the extension lengths of the upper main cutting edge 122 and the upper sub cutting edge 123 substantially defines the side length of the cutting insert 1, and in the case where the insert outer dimensions are limited, it is possible to secure a sufficient length of the upper main cutting edge 122 with such a design, so that the machining efficiency can be secured. While the upper minor cutting edge 123 is generally used as a wiper edge, its workability can be ensured even with a small length. In other words, the overall size of the cutting insert 1 can be reduced by such a design, which is advantageous in greatly reducing the material cost, in comparison with the case where the upper main cutting edge 122 has the same cutting length.

Referring back to fig. 1 and 2, in a direction from the upper cutting edge 12 toward the central bore 15, the upper surface 11 further includes an upper rake surface 114 disposed along the upper cutting edge 12, an upper confining surface 115 disposed about the central bore 15, and an upper transition surface 116 connected between the upper confining surface 115 and the upper rake surface 114. Wherein the upper rake surface 114 is closer to the lower surface 13 as it is farther from the upper cutting edge 12, and the upper confining surface 115 is closer to the lower surface 13 than the upper rake surface 114.

The upper rake surface 114 defines the rake angle of the upper cutting edge 12, which may be set appropriately according to the circumstances. Referring to fig. 3, the upper rake surface 114 includes an upper major rake surface 1142 along the upper major cutting edge 122 and an upper minor rake surface 1143 along the upper minor cutting edge 123, corresponding to the upper major cutting edge 122 and the upper minor cutting edge 123 described above. The upper major rake surface 1142 and the upper minor rake surface 1143 may be designed according to the requirements of the upper major cutting edge 122 and the upper minor cutting edge 123, respectively.

The upper restraining surface 115 is a plane perpendicular to the central axis L1, and is used to form a restraint with the shank 2, and to maintain the position of the cutting insert 1 mounted on the shank 2. Because the upper restraining surface 115 is closer to the lower surface 13 than the upper cutting edge 12, that is, the upper restraining surface 115 is of a concave structure than the upper cutting edge 12, a larger chip discharging space can be formed between the upper cutting edge 12 and the upper restraining surface 115, and chips can be discharged conveniently.

The upper transition surface 116 is a transition structure between the upper constraining surface 115 and the upper rake surface 114, and the upper transition surface 116 is closer to the lower surface 13 as it is farther from the upper rake surface 114 in the direction from the upper rake surface 114 toward the center hole 15, and the "step" between the upper cutting edge 12 and the upper constraining surface 115 can be further increased by the upper transition surface 116.

As mentioned before, the upper surface 11 and the lower surface 13 are interchangeable when the cutting insert 1 is turned upside down, the structure of the lower surface 13 being virtually identical to the upper surface 11.

Still referring to fig. 1, the outer edge of the lower surface 13 includes a first lower edge 132, a second lower edge 133 intersecting 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, as seen in fig. 1 at the lower corner 131 of the lower surface 13 at the intermediate position. Wherein the lower corner 131 is opposite from 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.

The lower corner 131 is circular-arc-shaped and is centrally symmetrical with the upper corner 111. Referring to fig. 3, when viewed from the top surface 11, the lower corner 131 intersects the upper corner 111 with a deflection angle therebetween, and the end point Q1 of the lower corner 131 that meets the first lower edge 132 is farther from the central axis L1 than the end point P2 of the upper corner 111 that meets the second upper edge 113, and the end point Q2 of the lower corner 131 that meets the second lower edge 133 is closer to the central axis L1 than the end point P1 of the upper corner 111 that meets the first upper edge 112. Wherein, the endpoint Q2 is indicated in fig. 4, which is not visible in fig. 3.

Referring to fig. 1, the lower cutting edge 14, which is disposed at the outer edge of the lower surface 13, includes a lower corner edge 141 at the lower corner 131, a lower main cutting edge 142 at the first lower edge 132, and a lower sub-cutting edge 143 at the second lower edge 133. The lower corner edge 141 is arc-shaped and perpendicular to the central axis L1. The lower corner edge 141 has the same extension shape as the upper corner edge 121, and is symmetrical with respect to the center. The lower main cutting edge 142 and the lower sub cutting edge 143 are respectively arranged at both sides of the lower corner edge 141 and are respectively connected to both ends of the circular arc of the lower corner edge 141.

Like the upper cutting edges 12, the lower cutting edges 14 are rotationally symmetrically arranged four along the outer edge of the lower surface 13. Correspondingly, a lower main cutting edge 142 belonging to one lower cutting edge 14 and a lower auxiliary cutting edge 143 belonging to the other lower cutting edge 14 are arranged between two adjacent lower corner edges 141, an upper auxiliary cutting edge 123 is arranged above the lower main cutting edge 142 correspondingly, an upper main cutting edge 122 is arranged above the lower auxiliary cutting edge 143, and the upper main cutting edge 122 is partially opposite to the lower main cutting edge 142 in the up-down direction.

Preferably, the lower minor cutting edge 143 is further biased toward the central axis L1 than the upper major cutting edge 122 above it, and conversely, as shown in fig. 3, the upper minor cutting edge 123 is also further biased toward the central axis L1 than the lower major cutting edge 142 below it, and the angle between the upper minor cutting edge 123 and the lower major cutting edge 142 below it is also θ, i.e., the angle between the upper minor cutting edge 123 and the extension line of an adjacent upper major cutting edge 122 as described above. The lower minor cutting edge 143 has the same included angle θ with the upper major cutting edge 122 thereabove.

The cutting insert 1 of the present embodiment is reversible and the associated 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 with different surface cutting edges.

For other features of the lower surface 13 reference is made to the description above regarding the upper surface 11.

Still referring to fig. 1, the outer peripheral surface 16 is rotationally symmetrical about the central axis L1 and includes a corner side surface 161, first and second side surfaces 162 and 163 that are respectively arranged on both sides of the corner side surface 161, a third side surface 164 that is positioned between the corner side surface 161 and the first side surface 162, and a fourth side surface 165 that is positioned between the corner side surface 161 and the second side surface 163. Preferably, the first side 162, the second side 163, the third side 164 and the fourth side 165 are all planar, and the first side 162 and the third side 164 may be connected by a transition surface (not numbered in the figure), and likewise, the second side 163 and the fourth side 165 may be connected by a transition surface.

Corner side 161 connects upper corner 111 of upper surface 11 and corresponding lower corner 131 of lower surface 13 for defining the relief angle of upper corner edge 121 and lower corner edge 141.

As shown in fig. 6, any cross section perpendicular to the central axis L1 between the upper surface 11 and the lower surface 13 has a circular arc shape at the intersection line of the corner side surface 161 and the cross section, and has the same extension shape as the upper corner 111 and the lower corner 131. As shown in connection with fig. 3, the portion of the corner side 161 near the fourth side 165 gradually gets away from the central axis L1 in the direction from the upper surface 11 toward the lower surface 13, whereas the portion of the corner side 161 near the third side 164, which is not shown in fig. 3, gradually slopes near the central axis L1 in the direction from the upper surface 11 toward the lower surface 13.

Referring to the view direction of fig. 4, the corner side 161 is deflected from top right to bottom left. Looking aside in the direction of the line connecting the end point P2 and the end point Q1, as shown in fig. 5, it can be understood that the end point P1 and the end point Q2 are not coincident: in the direction from the upper surface 11 to the lower surface 13, the corner side 161 is a curved surface formed by a variation of rotation and movement of an arc defined by the end point P1 and the end point P2 (i.e., the upper corner 111) to an arc defined by the end point Q2 and the end point Q1 (i.e., the lower corner 131). With this curved surface form, the amplitude of rotation and movement changes is not large, and the entire corner side surface 161 is smoothly connected, and sharp or sharp intersecting edges do not occur, so that the blade can be ensured to have sufficient strength, and the phenomenon of local stress concentration does not occur in the sintering process of the blade.

At the same time, the corner side 161 can be better connected with the third side 164 and the fourth side 165 at two sides by adopting the changing curved surface.

Referring to fig. 1 and 6, the third side 164 connects the second lower edge 133 of the lower surface 13, connects with the lower minor cutting edge 143, and slopes away from the central axis L1 as it moves away from the lower minor cutting edge 143. Conversely, third side 164 is gradually inclined toward central axis L1 in the direction from upper surface 11 toward lower surface 13, as is the tendency of corner side 161 to change toward the portion of third side 164, and the transition between corner side 161 and third side 164 is smoother, improving stress distribution.

The third side surface 164 defines a relief angle of the lower sub-cutting edge 143 as a relief angle surface of the lower sub-cutting edge 143, and the relief angle of the lower sub-cutting edge 143 is a negative angle greater than 90 ° in accordance with the inclination of the third side surface 164.

The width of the third side 164 gradually decreases as it gets farther from the lower sub-cutting edge 143. As shown in fig. 4, the upper end point of the third side 164 is adjacent to the junction point P1 of the upper corner 111 and the first upper edge 112, and the third side 164 has an approximately triangular shape as a whole. With this design, the area occupied by the third side surface 164 in the entire outer peripheral surface 16 can be reduced as much as possible while facilitating chip discharge of the lower sub-cutting edge 143.

Still referring to fig. 1 and 6, the fourth side 165 is centrally symmetrical to the third side 164, and the fourth side 165 connects to the second upper edge 113 of the upper surface 11, connects to the upper minor cutting edge 123, and slopes away from the central axis L1 as it moves away from the upper minor cutting edge 123. The change trend of the fourth side surface 165 is the same as the change trend of the portion of the corner side surface 161 near the fourth side surface 165, and the transition connection between the corner side surface 161 and the third side surface 164 is smoother, improving the stress distribution.

The width of the fourth side 165 gradually decreases as it gets farther from the upper minor cutting edge 123. As shown in fig. 4, the lower end point of the fourth side surface 165 is adjacent to the contact point Q1 between the lower corner 131 and the first lower edge 132, and the fourth side surface 165 has an approximately inverted triangle shape as a whole, and the area occupied by the fourth side surface 165 on the entire outer peripheral surface 16 can be reduced as much as possible by this design while facilitating chip discharge of the upper sub-cutting edge 123.

The fourth side surface 165 defines the relief angle of the upper sub cutting edge 123 as the relief angle surface of the upper sub cutting edge 123, and the relief angle of the upper sub cutting edge 123 is greater than 90 ° depending on the manner in which the fourth side surface 165 is obliquely arranged.

Referring to fig. 1, the first side 162 is connected to the first upper edge 112, is connected to the upper main cutting edge 122, and is parallel to the central axis L1. The first side 162 defines a relief angle of the upper major cutting edge 122 as a relief angle surface of the upper major cutting edge 122, and the relief angle of the upper major cutting edge 122 is a negative angle of 90 ° depending on the configuration of the first side 162.

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

The first side surface 162 and the second side surface 163 are rotationally symmetrical about the central axis L1. In this embodiment, the lower end of the first side 162 is connected to the other lower main cutting edge 142 of the lower surface 13, i.e. the lower end of the first side 162 is connected to the rightmost lower main cutting edge 142 of the lower surface 13, and the first side 162 also serves as a relief surface of the rightmost lower main cutting edge 142, as seen in the view direction of fig. 1. While the upper end of the second side 163 is also connected to the other upper main cutting edge 122 of the upper surface 11, seen in the view direction of fig. 1, i.e. the upper end of the second side 163 is connected to the leftmost upper main cutting edge 122 of the upper surface 11, the second side 163 also functioning as a relief surface for the leftmost upper main cutting edge 122.

If the object is considered in terms of structure between two adjacent corner sides 161, then there is a third side 164 between two adjacent corner sides 161 that is immediately adjacent to one of the corner sides 161, a fourth side 165 that is immediately adjacent to the other corner side 161, a first side 162 that is connected to the third side 164, and a second side 163 that is connected to the fourth side 165. In a particular configuration of this embodiment, the first side 162 and the second side 163 are coplanar. Colloquially, the invention is based on the following. Between adjacent two corner positions 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. According to this design, a plurality of cutting edges can be designed by making full use of the outer peripheral shape of the cutting insert 1, improving the utilization ratio of the cutting insert 1, and facilitating miniaturization of the size of the cutting insert 1 while ensuring the cutting length.

The first side surface 162 and the second side surface 163 are both planes parallel to the central axis L1, and when the cutting tool is mounted in an indexing manner, the first side surface 162 or the second side surface 163 which does not participate in cutting and is away from the workpiece is in contact with the shank as a restraining surface, and the restraining effect is improved by the plane contact manner. In addition, according to the above description, since the third side surface 164 and the fourth side surface 165 each have a structure in which the width is gradually reduced, the first side surface 162 and the second side surface 163 can occupy a large area of the entire outer peripheral surface 16, and the contact area can be increased when the surfaces are used as the restraining surfaces, and the restraining effect can be similarly improved.

In connection with the description above, and referring next to fig. 7-14, for an upper cutting edge 12, the fourth side surface 165 defines the relief angle of its upper minor cutting edge 123, the upper minor rake surface 1143 defines the relief angle of the upper minor cutting edge 123, the corner side surface 161 defines the relief angle of the upper corner edge 121, the first side surface 162 defines the relief angle of the upper major cutting edge 122, and the upper major rake surface 1142 defines the relief angle of the upper major cutting edge 122.

Specifically, fig. 8 and 9 illustrate cross-sectional views at two different positions of the upper sub-cutting edge 123, respectively.

Since the fourth side 165 is a plane, an angle a1 of the fourth side 165 with respect to the base surface in fig. 8 is the same as an angle b1 of the fourth side 165 with respect to the base surface in fig. 9, wherein the base surface is a virtual plane perpendicular to the central axis L1, which is not shown in the drawing. The angles a1 and b1 are rear angles of the upper sub cutting edge 123, and the rear angle of the upper sub cutting edge 123 is a negative angle greater than 90 ° due to the inclined arrangement of the fourth side surface 165 with respect to the central axis L1, whereby the strength of 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.

The angle a2 of the upper auxiliary rake surface 1143 with respect to the base surface in fig. 8 and the angle b2 of the upper auxiliary rake surface 1143 with respect to the base surface in fig. 9 are rake angles at two different positions of the upper auxiliary cutting edge 123, respectively, and the angle a2 and the angle b2 may be the same or different and flexibly set according to actual needs.

Under the condition of the same blade thickness, that is, under the condition of ensuring that the included angle between the upper auxiliary rake surface 1143 and the fourth side surface 165 is constant, since the relief angle of the upper auxiliary cutting edge 123 is a negative angle, the upper auxiliary rake surface 1143 can deviate from the base surface more than the case that the relief angle is a positive angle, that is, the angle of the upper auxiliary rake surface 1143 relative to the base surface, that is, the rake angle, is correspondingly increased. And the greater the rake angle, the sharper the blade, and thus the sharpness of the upper sub-cutting edge 123 can be improved, thereby making the machined surface formed by the upper sub-cutting edge 123 smoother.

Fig. 13 illustrates a cross-sectional view of the first transition portion 1222 of the upper main cutting edge 122, and fig. 14 illustrates a cross-sectional view of the first straight portion 1221 of the upper main cutting edge 122.

The angle f1 of the first side 162 with respect to the base surface in fig. 13 and the angle g1 of the first side 162 with respect to the base surface in fig. 14 are both 90 °. Namely: the relief angle of the first transition portion 1222 and the first straight portion 1221 of the upper major cutting edge 122 are both 90 °. The relief angle of the upper primary cutting edge 122 is smaller than the relief angle of the upper secondary cutting edge 123.

The angle f2 of the upper main front surface 1142 with respect to the base surface in fig. 13 is the front angle of the first transition portion 1222, the angle g2 of the upper main front surface 1142 with respect to the base surface in fig. 14 is the front angle of the first straight line portion 1221, and the angles f2 and g2 may be the same or different and flexibly set according to actual needs.

As described above, the upper minor rake surface 1143 is offset to a greater extent than the upper major rake surface 1142 toward the lower surface 13, e.g., the base surface is referenced, i.e., the upper minor rake surface 1143 defines a greater rake angle for the upper minor cutting edge 123 than the upper major rake surface 1142 defines the upper major cutting edge 122.

By properly setting the inclination angles of the fourth side surface 165, the upper minor rake surface 1143, and the upper major rake surface 1142, the insert thickness at the upper major cutting edge 122 and the upper minor cutting edge 123 can be made uniform.

In addition, as can be seen in fig. 13 and 1, at the first transition 1222, a third side 164 is further connected below the first side 162, the third side 164 being deflected in the direction of the central axis L1 compared to the first side 162.

Fig. 10 is a cross-sectional view showing a portion of the upper corner edge 121 toward the upper minor cutting edge 123, fig. 11 is a cross-sectional view showing a center position of the upper corner edge 121, and fig. 12 is a cross-sectional view showing a portion of the upper corner edge 121 toward the upper major cutting edge 122. The angle of the corner side 161 with respect to the base surface is the relief angle of the upper corner edge 121.

As described above, since the corner side surface 161 is a curved surface which deflects, the relief angle of the upper corner edge 121 at different positions is changed, the relief angle c of the portion which deflects to the side of the upper sub-cutting edge 123 shown in fig. 10 is a negative angle of more than 90 °, the relief angle d at the center position shown in fig. 11 is a negative angle of approximately 90 °, and the relief angle e of the portion which deflects to the side of the upper main cutting edge 122 shown in fig. 12 is a positive angle of less than 90 °.

Referring to fig. 15 to 18, the present embodiment provides a tool having the above-described cutting insert 1, which is a face milling cutter, and the shank 2 thereof is a face milling cutter head. During machining, the tool shank 2 is mounted to a machine tool (not shown), and rotates about the rotation axis L2 to drive the cutting insert 1 to machine the workpiece 4.

Referring to fig. 15 and 17, the lower end portion of the shank 2 is provided with a plurality of mounting grooves 21 in the circumferential direction for mounting a plurality of cutting inserts 1, respectively. The structural shape of the mounting groove 21 is set according to the structural shape of the cutting insert 1. The cutting insert 1 is mounted in the mounting groove 21 and fastened by means of the fastener 3.

It is particularly noted that, according to the structure of the cutting insert 1 described above, the seating surface 211 of the mounting groove 21 is provided as a flat surface for cooperation with the upper restraining surface 115 of the upper surface 11 or the lower restraining surface 13 of the cutting insert 1; the side 212 of the mounting groove 21 is provided as a plane for cooperation with the first side 162 or the second side 163 of the cutting insert 1. By adopting the planar restraining fit, the structure of the mounting groove 21 can be simplified and the restraining effect can be improved.

As shown in fig. 17, the seat surface 211 is normally biased forward in the rotation direction with respect to the rotation axis L2, and an angle β is formed between the seat surface 211 and the rotation axis L2. The side surface 212 of the mounting groove 21 also has a certain deflection angle with respect to the rotation axis L2 in the radial direction of the shank 2. Accordingly, as shown in fig. 16 and 18, the cutting insert 1 is mounted in the mounting groove 21 so as to be inclined with respect to the rotation axis L2, and one of the upper cutting edge 12 and the lower cutting edge 14 is protruded from the outer periphery and the lower side of the shank 2 to machine the workpiece 4.

Taking one of the upper cutting edges 12 as an example in connection with fig. 16 and 18, the upper main cutting edge 122 processes the side end surface 41 of the workpiece 4, and 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 as being away from the lower auxiliary cutting edge 143, and accordingly, as reference is made to the first side surface 162, the third side surface 164 is more biased toward the central axis L1 (see fig. 1 and 13 in particular), and 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, so that the quality of the processed surface of the upper cutting edge 12 is not affected by the presence of the lower cutting edge 14.

Similarly, as seen when one of the lower cutting edges 14 is involved 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 face the side end surface 41 of the workpiece 4, and since the fourth side surface 165 is inclined away from the central axis L1 as it is away from the upper sub cutting edge 123, 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 the presence of the upper cutting edge 12 does not affect the quality of the surface machined by the lower cutting edge 14.

In combination, the upper cutting edge 12 and the lower cutting edge 14 of the cutting insert 1 do not affect the machining with each other, and the quality of the machined surface can be improved for the cutting insert 1 used on both sides.

Further, referring to the description of the cutting insert 1 hereinabove, the upper and lower opposite major cutting edges 122 and the lower minor cutting edges 143 have an included angle θ therebetween, and the lower minor cutting edges 143 are more biased toward the central axis L1 than the upper major cutting edges 122. Also, the upper and lower opposite lower main cutting edges 142 and the upper sub cutting edge 123 have an angle θ therebetween, and the upper sub cutting edge 123 is more biased toward the central axis L1 than the lower main cutting edge 142. The included angle θ may be matched with an axial inclination angle β of the cutting insert 1 on the shank 2 and a radial inclination angle, which is not shown, to adjust a machining track of the upper auxiliary cutting edge 123 or the lower auxiliary cutting edge 143 to be parallel to the bottom surface 42 of the workpiece 4, thereby ensuring machining accuracy of the bottom surface 42 of the workpiece 4 after the upper auxiliary cutting edge 123 or the lower auxiliary cutting edge 143 is machined.

The above embodiment has been described by taking the cutting insert 1 as an example of a rectangular block structure, the cutting insert 1 has eight cutting edges in total, machining can be performed in eight directions by indexing, and the utilization rate of the cutting insert 1 is high. In other embodiments, the cutting insert 1 may also have other numbers of cutting edges, and the shape of the cutting insert 1 may be adapted.

For example, fig. 19 illustrates another embodiment of a cutting insert 5 having six cutting edges. The cutting insert 5 is also a double-sided usable insert having an upper surface 51, a lower surface 53, which are opposite to each other in the upper and lower directions, and an outer peripheral surface 56 between the upper and lower surfaces 51, 53. An upper cutting edge 52 is provided at the outer edge of the upper surface 51, and a lower cutting edge 54 is provided at the outer edge of the lower surface 53, and cutting processing can be performed by the upper cutting edge 52 and the lower cutting edge 54, respectively. The cutting insert 5 also has a central bore 55 through the upper and lower surfaces 51, 53. The outer edges of the upper surface 51 and the lower surface 53 are each in a rotationally symmetrical pattern with the center of the upper surface 51 and the center of the lower surface 53 being located on the central axis L5 of the central hole 55.

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.

The first upper edge 512, the upper corner 511 and the second upper edge 513 are formed as one unit, and the outer edge of the entire upper surface 51 is formed by three such units connected end to end, the three units being rotationally symmetrical about the central axis L5.

The upper cutting edge 52 includes an upper corner edge 521 at the upper corner 511, an upper major cutting edge 522 at the first upper edge 512, and an upper minor cutting edge 523 at the second upper edge 513. Wherein the upper minor cutting edge 523 extends along only a portion of the length of the second upper edge 513 proximate to the upper corner 511, the other portion of the second upper edge 513 being devoid of cutting edges.

The outer edge of the lower surface 53 includes a first lower edge 532, a second lower edge 533 intersecting the first lower edge 532, and a lower corner 531 at the intersection of the first lower edge 532 and the second lower edge 533.

The lower cutting edge 54 includes a lower corner edge 541 at a lower corner 531, a lower major cutting edge 542 at a first lower edge 532, and a lower minor cutting edge 543 at a second lower edge 533. Likewise, the lower minor cutting edge 543 extends along only a portion of the length of the second lower edge 533 adjacent the lower corner 531, and no cutting edge is provided at other portions of the second lower edge 533.

The outer peripheral surface 56 includes a corner side surface 561 connecting the upper corner 511 and the lower corner 531, first and second side surfaces 562 and 563 respectively arranged at both sides of the corner side surface 561, a third side surface 564 positioned between the corner side surface 561 and the first side surface 562, and a fourth side surface 565 positioned between the corner side surface 561 and the second side surface 563.

The first side 562 connects the upper and lower opposite first and second upper edges 512, 533 with the upper major cutting edge 522 and is parallel to the central axis L5.

The second side 563 connects the upper and lower opposed first lower edge 532 and the second upper edge 513, with the lower main cutting edge 542, and is parallel to the central axis L5.

The third side 564 connects the second lower edge 533, connects with the lower sub-cutting edge 543, and slopes away from the central axis L5 as it moves away from the lower sub-cutting edge 543.

The fourth side 565 connects to the second upper edge 513, connects to the upper minor cutting edge 523, and slopes away from the central axis L5 as it moves away from the upper minor cutting edge 523.

In this embodiment, between two adjacent corner sides 561, the first side 562 and the second side 563 are not coplanar, and the first side 562 and the second side 563 are connected circumferentially and form an obtuse included angle.

In this embodiment, the upper cutting edge 52 and the lower cutting edge 54 do not affect each other's processing surface due to the inclination of the third side surface 564 and the fourth side surface 565 away from the central axis L5, and the quality of the processing surface is improved.

In fig. 19, the upper surface 51 and the lower surface 53 are simplified to be planar, and in a practical structure, the upper surface 51 and the lower surface 53 may be provided with a rake face, a transition face, and an extension face with reference to the structure shown in fig. 1.

While the invention has been described with reference to several exemplary embodiments, it is to be understood that the terminology used is intended to be in the nature of words of description and of limitation. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.

Claims (12)

1. A cutting insert, characterized by comprising:

   an upper surface having:

   a first upper edge;

   a second upper edge intersecting the first upper edge; and

   An upper corner located at the intersection of the first upper edge and the second upper edge;

   an upper cutting edge located at an outer edge of the upper surface, comprising:

   an upper corner edge located at the upper corner;

   the upper main cutting edge is positioned at the first upper edge and is connected with the upper corner edge; and

   The upper auxiliary cutting edge is positioned at the second upper edge and is connected with the upper corner edge;

   a lower surface having:

   a first lower edge located below the second upper edge;

   a second lower edge intersecting the first lower edge and located below the first upper edge; and

   A lower corner located at the intersection of the first lower edge and the second lower edge;

   a lower cutting edge located at an outer edge of the lower surface, comprising:

   a lower corner edge located at the lower corner;

   the lower main cutting edge is positioned at the first lower edge and is connected with the lower corner edge; and

   The lower auxiliary cutting edge is positioned at the second lower edge and is connected with the lower corner edge;

   a central axis passing through the center of the upper surface and the center of the lower surface; and

   An outer peripheral surface located between the upper surface and the lower surface, comprising:

   a corner side connecting the upper corner and the lower corner;

   the first side surface is connected with the first upper edge, is connected with the upper main cutting edge and is parallel to the central shaft;

   a second side surface connected to the first lower edge, connected to the lower main cutting edge, and parallel to the central axis;

   a third side surface located between the corner side surface and the first side surface, connecting the second lower edge, connected to the lower sub-cutting edge, and inclined away from the central axis as it is away from the lower sub-cutting edge; and

   And a fourth side surface which is positioned between the corner side surface and the second side surface, is connected with the second upper edge, is connected with the upper auxiliary cutting edge, and is inclined away from the central shaft along with being far away from the upper auxiliary cutting edge.
2. The cutting insert according to claim 1, wherein the upper and lower opposed major cutting edges have an included angle θ therebetween and the lower minor cutting edge is more biased toward the central axis than the upper major cutting edge.
3. The cutting insert according to claim 2, wherein 0 < θ+.10 °.
4. The cutting insert according to claim 1 wherein the upper primary cutting edge has an extension greater than the extension of the upper secondary cutting edge; the extension length of the lower main cutting edge is greater than the extension length of the lower auxiliary cutting edge.
5. The cutting insert according to claim 1, wherein the first side surface, the second side surface, the third side surface, and the fourth side surface are all planar.
6. The cutting insert according to claim 1, wherein the upper corner and the lower corner are centrally symmetrical; the end point of the lower corner that meets the first lower edge is farther from the central axis than the end point of the upper corner that meets the second upper edge when viewed from above the upper surface, and the end point of the lower corner that meets the second lower edge is closer to the central axis than the end point of the upper corner that meets the first upper edge.
7. The cutting insert according to claim 6, wherein the upper and lower corners each extend in an arc shape and are each perpendicular to the central axis; the extension shape of the corner side surface is the same as the extension shape of the upper corner and the lower corner on any section perpendicular to the central axis between the upper surface and the lower surface.
8. The cutting insert according to claim 1, wherein the width of the third side surface gradually decreases as it moves away from the lower minor cutting edge; the width of the fourth side surface gradually decreases with the upper auxiliary cutting edge.
9. The cutting insert according to claim 8, wherein an upper end point of the third side surface abuts to the junction of the upper corner and the first upper edge; the lower end point of the fourth side surface is adjacent to the junction of the lower corner and the first lower edge.
10. The cutting insert according to any one of claims 1-9, wherein the upper surface further comprises an upper rake surface disposed along the upper cutting edge, the upper rake surface being closer to the lower surface as it is farther from the upper cutting edge in a direction toward the central axis.
11. The cutting insert of claim 10, wherein the upper surface further comprises a restraining surface disposed about and perpendicular to the central axis, the restraining surface being closer to the lower surface than the upper cutting edge.
12. A cutting tool comprising a shank and the cutting insert according to any one of claims 1-11 mounted on the shank.