CN110860723B

CN110860723B - Cutting blade for hole machining

Info

Publication number: CN110860723B
Application number: CN201911234092.9A
Authority: CN
Inventors: 江爱胜; 王社权; 吴火飞; 刘伟; 宋步光; 文娟
Original assignee: Zhuzhou Cemented Carbide Cutting Tools Co Ltd
Current assignee: Zhuzhou Cemented Carbide Cutting Tools Co Ltd
Priority date: 2019-12-05
Filing date: 2019-12-05
Publication date: 2021-01-29
Anticipated expiration: 2039-12-05
Also published as: CN110860723A

Abstract

The invention discloses a cutting blade for hole processing, which comprises a blade body in a quadrilateral plate shape, wherein the blade body is surrounded by an upper surface, a lower surface and a side surface connecting the upper surface and the lower surface, the side surface and the upper surface are intersected to form four main cutting edges and four corner cutting edges positioned between the adjacent main cutting edges, the upper surface comprises a central surface positioned in a central area and a groove profile positioned at the periphery of the central surface, the groove profile comprises a groove front surface, a groove back surface and a groove bottom surface positioned between the groove front surface and the groove back surface, the groove front surface is adjacent to the main cutting edges and the corner cutting edges, the groove back surface is adjacent to the central surface, the main cutting edges comprise a straight cutting edge and a waveform cutting edge, the groove back surface and the central surface corresponding to the same main cutting edge are intersected to form a waveform critical line, and the waveform amplitude of the waveform, has the advantages of smooth chip removal, good processing surface quality, small cutting vibration, long service life and the like.

Description

Cutting blade for hole machining

Technical Field

The present invention relates to metal cutting machining, and more particularly, to a cutting insert for hole machining.

Background

The drilling tool mainly bears cutting force at the cutting end part during cutting, and in order to guarantee the processing depth of a hole, the cutting end part of the drilling tool generally has larger overhang, but because a spiral groove of the drilling tool and a processing surface form a closed area, chips can only be discharged from the cutting end part through the spiral groove, the chips are difficult to discharge, when the chips cannot be discharged out of a workpiece in time, the accumulated chips are severely scraped and extruded between the spiral groove and the processing surface, and the tool body can generate larger cutting vibration due to unbalance of circumferential stress, so that the quality of the processing surface is reduced, and the service life of the drilling tool can be greatly reduced.

In the prior art, in order to avoid the damage of the end part of a cutter to cause the rejection of the whole cutter and reduce the use cost of the cutter, a drilling cutter can be designed into a split structure, a cutting unit consists of cutting blades, a clamping handle part consists of a cutter body, the cutting unit can be repeatedly assembled and disassembled on the cutter body, the cutting unit consists of an inner cutting blade and an outer cutting blade, the processing of the central area and the peripheral area of a hole is respectively completed, the upper surfaces of the inner cutting blade and the outer cutting blade respectively comprise a groove profile participating in the cutting and a central plane not directly participating in the cutting, the groove profile consists of a groove front surface, a groove bottom surface and a groove back surface, the groove front surface is firstly cut into a workpiece, chips flow through the groove front surface and the groove bottom surface and are finally separated from the groove back surface, therefore, the shape of the groove back surface is a key factor influencing the shape and the curling, the cutting speed is gradually reduced from the circumferential center until the speed is zero, the back of the general cutting blade groove is basically parallel to the main cutting edge in the upper surface direction, and when the cutting blade groove is applied to drilling machining, the chip control capability is poor, so that the technical problems of large cutting vibration, rough machining surface, short service life of a cutter and the like are caused.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects of the prior art and provides a cutting blade for hole machining, which has the advantages of smooth chip removal, good machining surface quality, small cutting vibration and long service life.

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

a cutting insert for hole machining includes an insert body in a quadrangular plate shape, the insert body being surrounded by an upper surface, a lower surface, and a side surface connecting the upper surface and the lower surface, the side surfaces and the upper surface intersect to form four main cutting edges and four corner cutting edges between adjacent main cutting edges, the upper surface includes a central surface in a central region and a channel profile at a periphery of the central surface, the groove profile comprises a groove front surface, a groove rear surface and a groove bottom surface positioned between the groove front surface and the groove rear surface, the flute leading face is adjacent the major and corner cutting edges, the flute trailing face is adjacent the central face, the main cutting edge comprises a straight cutting edge and a waveform cutting edge, the back surface and the central surface of the groove corresponding to the same main cutting edge are intersected to form a waveform critical line, in the upper surface direction, the amplitude of the waveform of the critical line is larger than the amplitude of the waveform cutting edge.

As a further improvement of the above technical solution:

in the upper surface direction, the maximum amplitude of the waveform critical line is H, and the maximum amplitude of the waveform cutting edge is H, which should satisfy: h is more than or equal to 7H and less than or equal to 13H.

The wave form cutting edge is located straight line at straight line cutting edge place is close to inside one side of blade body, be equipped with the third cutting edge between wave form cutting edge and the adjacent corner cutting edge, two relatively distance between the straight line cutting edge is L1, two relatively distance between the third cutting edge is L2, four wave form cutting edge has common inscribed circle and inscribed circle diameter and should satisfy: l2 is more than or equal to 1.02D and less than or equal to L1 and less than or equal to 1.2D.

In the upper surface direction, the wave-shaped critical line is provided with a first inner wave trough, a second inner wave trough and a third inner wave trough in sequence in the direction extending from the straight cutting edge to the third cutting edge on the same side, the maximum depths of the first inner wave trough, the second inner wave trough and the third inner wave trough are respectively H1, H2 and H3, and the wave-shaped critical line should satisfy the following conditions: h3+0.01D is not less than H1 and not more than H2-0.01D.

On the upper surface direction, the wave form cutting edge is equipped with first trough, second trough and third trough in proper order in the direction that the straight line cutting edge from the homonymy extends to third cutting edge, contained angle between the ripples tooth of first trough, second trough, third trough both sides is alpha 1, alpha 2, alpha 3 respectively, should satisfy: alpha 2 is more than or equal to 150 degrees and more than or equal to 3 degrees and more than or equal to alpha 2 is more than or equal to 1 degrees and more than or equal to 3 degrees and more than or equal to 178 degrees.

The side include respectively with main cutting edge, the major flank and the turning face that the turning cutting edge corresponds, the major flank includes the first major flank of neighbouring upper surface, the second major flank of neighbouring lower surface and is located the transition side between first major flank, the second major flank, first major flank include respectively with first straight flank, first ripples side and the first minor flank that straight line cutting edge, wave form cutting edge, third cutting edge correspond, the second major flank include respectively with second straight flank, second ripples side and the second minor flank that straight line cutting edge, wave form cutting edge, third cutting edge correspond, the transition side respectively with first straight flank, first ripples side, first minor flank and the contact of second ripples side.

The relief angle of the first straight side surface is γ 1, the relief angle of the first wave side surface is γ 2, and the relief angle of the second wave side surface is γ 3, which satisfy the following requirements: gamma 3-gamma 2 is more than or equal to 2 degrees and less than or equal to 6 degrees, and gamma 1-gamma 3 is more than or equal to 2 degrees and less than or equal to 6 degrees.

The length of the third cutting edge is X and satisfies the following conditions: x is more than or equal to 0.2mm and less than or equal to 1.2 mm.

The third cutting edge is the linear type cutting edge, the contained angle of the linear cutting edge in the main cutting edge that third cutting edge and this third cutting edge correspond is beta, should satisfy: beta is more than or equal to 5 degrees and less than or equal to 20 degrees.

The third cutting edge is an arc-shaped cutting edge, the curvature radius of the third cutting edge is R1, and the following requirements are met: r1 is more than or equal to 20mm and less than or equal to 50 mm.

Compared with the prior art, the invention has the advantages that:

according to the cutting blade for hole machining, the main cutting edge comprises the linear cutting edge and the waveform cutting edge, the linear cutting edge can ensure stable cutting, the wave crests, the wave teeth and the wave troughs of the waveform units of the waveform cutting edge are stressed differently, and the cutting force on the waveform cutting edge is distributed in different directions along with the increase of the number of the waveform units participating in cutting, so that the cutting force in a single direction on the main cutting edge can be effectively reduced, a plurality of waveform units of the waveform cutting edge sequentially cut into a workpiece, the cutting vibration is effectively reduced, and the stability of the cutting blade in the workpiece is improved; the groove profile comprises a groove front surface, a groove bottom surface and a groove back surface, the groove front surface is firstly cut into a workpiece, chips flow through the groove front surface and the groove bottom surface and are finally separated from the groove back surface, the waveform amplitude of a waveform critical line is larger than that of a waveform cutting edge, namely, the waveform boundary of the groove back surface has larger waveform depth than the waveform cutting edge, even if the cutting linear velocity difference of each position of the cutting blade is larger, even if the central cutting speed is zero, the chips with regular radius change can be still generated in the hole processing process, only a local crest part of the chips is contacted with the waveform boundary, the waveform critical line part contacted with the chips is prevented from being rapidly heated and worn by huge extrusion stress, the problem that the chip radius on the waveform critical line is continuously increased to cause the loss of chip guide capacity is avoided, the large chips are not easy to be discharged, the quality of a, the waveform critical line with the specific shape can accurately guide the flow direction of the cutting chips, effectively inhibit the cutting chips and partial parts behind the groove from periodically and repeatedly extruding and scraping, avoid high-stress abrasion grooves on the back surface of the groove, ensure the cutting performance stability of the blade by uniformly contacting and timely breaking the cutting chips with the back surface of the groove all the time, thereby effectively improving the quality of the processed surface, reducing the cutting vibration, improving the cutting efficiency of the blade and prolonging the service life of the blade.

Drawings

Fig. 1 is a perspective view of a cutting insert for hole machining according to the present invention.

Fig. 2 is a front view of a cutting insert for hole machining according to the present invention.

Fig. 3 is a side view of a cutting insert for hole machining according to the present invention.

Fig. 4 is a rear view of the cutting insert for hole machining of the present invention.

Fig. 5 is a sectional view a-a of fig. 2.

Fig. 6 is a sectional view B-B of fig. 2.

Fig. 7 is an enlarged view at C in fig. 2.

The reference numerals in the figures denote:

1. a blade body; 2. an upper surface; 21. a groove profile; 211. a slot front; 212. behind the groove; 213. the bottom surface of the groove; 22. a central plane; 23. a waveform critical line; 3. a lower surface; 4. a side surface; 41. a major side; 411. a first major side; 4111. a first straight side; 4112. a first wave flank; 4113. a first short side; 412. a second major side; 4121. a second straight side; 4122. a second wave flank; 4123. a second short side; 413. a transition side; 42. a corner surface; 43. a concave side; 5. a main cutting edge; 51. A linear cutting edge; 52. a wave-shaped cutting edge; 53. a third cutting edge; 6. a corner cutting edge; 71. a first trough; 72. a second trough; 73. a third trough; 81. a first inner trough; 82. a second inner trough; 83. a third inner trough; 9. a central bore; 10. a shaft.

Detailed Description

The invention will be described in further detail below with reference to the drawings and specific examples.

Fig. 1 to 7 show an embodiment of the cutting insert for hole machining according to the present invention, which comprises an insert body 1 having a quadrangular plate shape, the insert body 1 being defined by an upper surface 2, a lower surface 3 and a side surface 4 connecting the upper surface 2 and the lower surface 3, the side surface 4 and the upper surface 2 intersecting to form four main cutting edges 5 and four corner cutting edges 6 between adjacent main cutting edges 5, the upper surface 2 comprising a central surface 22 in a central region and a groove profile 21 at the periphery of the central surface 22, the groove profile 21 comprising a groove front surface 211, a groove rear surface 212 and a groove bottom surface 213 between the groove front surface 211 and the groove rear surface 212, the groove front surface 211 being adjacent to the main cutting edge 5 and the corner cutting edges 6, the groove rear surface 212 being adjacent to the central surface 22, the main cutting edge 5 comprising a straight cutting edge 51 and a wave-shaped cutting edge 52, the groove rear surface 212 corresponding to the same main cutting edge 5, The central planes 22 are intersected to form a waveform critical line 23, the waveform amplitude of the waveform critical line 23 is greater than the waveform amplitude of the waveform cutting edge 52 in the direction of the upper surface 2, the main cutting edge 5 comprises a linear cutting edge 51 and a waveform cutting edge 52, the linear cutting edge 51 can ensure stable cutting, the wave crests, the wave teeth and the wave troughs of the waveform units of the waveform cutting edge 52 are subjected to different stresses, the cutting force on the waveform cutting edge 52 is distributed in different directions along with the increase of the number of the waveform units participating in cutting, the unidirectional cutting force on the main cutting edge 5 can be effectively reduced, the plurality of waveform units of the waveform cutting edge 52 are sequentially cut into a workpiece, the cutting vibration is effectively reduced, and the stability of the cutting blade in the workpiece is improved; the groove profile 21 comprises a groove front face 211, a groove bottom face 213 and a groove back face 212, wherein the groove front face 211 is firstly cut into a workpiece, chips flow through the groove front face 211 and the groove bottom face 213 and are finally separated from the groove back face 212, the amplitude of the waveform critical line 23 is larger than that of the waveform cutting edge 52, namely, the waveform boundary of the groove back face 212 has larger waveform depth than that of the waveform cutting edge 52, even if the cutting linear velocity difference of each position of the cutting blade is larger, even if the central cutting velocity is zero, the chips with regular radius change can be still ensured to be generated in the hole processing process, the waveform boundary with a specific shape can accurately guide the flow direction of the chips, the chips and the groove back face 212 are effectively inhibited from generating periodical and repeated extrusion and scraping, high stress abrasion grooves are avoided on the groove back face 212, the chips are always in uniform contact with the groove back, the cutting efficiency of the blade is improved, and the service life of the blade is prolonged.

In the direction of the upper surface 2, the maximum amplitude of the waveform critical line 23 is H, the maximum amplitude of the waveform cutting edge 52 is H, in order to ensure that the chips are highly contacted and attached with the waveform critical line 23, avoid the generation of high-stress abrasion grooves, ensure the stability of the curling radius of the chips, reduce the cutting vibration, improve the processing precision and prolong the cutting life. It should satisfy: h is less than or equal to 7H and less than or equal to 13H, and in the embodiment, H = 9.5H.

In this embodiment, the waveform cutting edge 52 is located on one side of the straight line where the straight line cutting edge 51 is located, which is close to the inside of the insert body 1, a third cutting edge 53 is provided between the waveform cutting edge 52 and the adjacent corner cutting edge 6, if the third cutting edge 53 is not provided, the shape of the waveform cutting edge 52 at the intersection of the corner cutting edge 6 between the straight line cutting edge 51 which is the outer side of the main cutting edge 5 will directly affect the quality of the machined surface, and the surface quality is obviously reduced along with the increase of the feeding of the straight line cutting edge 51, therefore, the third cutting edge 53 is provided to ensure that the cutting insert still has good surface machining quality at different feeding, and the length of the third cutting edge 53 is X: x is more than or equal to 0.2mm and less than or equal to 1.2mm, the third cutting edge 53 is a linear cutting edge, the included angle between the third cutting edge 53 and the linear cutting edge 51 in the main cutting edge 5 corresponding to the third cutting edge 53 is beta, and the following requirements are met: beta is more than or equal to 5 degrees and less than or equal to 20 degrees. In the present embodiment, β =15 °, X =0.6 mm.

In the present embodiment, the distance between two opposite straight cutting edges 51 is L1, the distance between two opposite third cutting edges 53 is L2, the four waveform cutting edges 52 have a common inscribed circle and the diameter of the inscribed circle is D, in order to ensure that the straight cutting edges 51, the waveform cutting edges 52 and the third cutting edges 53 cut into the workpiece in sequence and ensure that the straight cutting edges 51, the waveform cutting edges 52 and the third cutting edges 53 have ideal cutting lengths, the following requirements should be satisfied: l2 is more than or equal to 1.02D and less than or equal to L1 and less than or equal to 1.2D. In this example, L1=1.1D, and L2= 1.05D.

In this embodiment, in the direction of the upper surface 2, the critical wavy line 23 is sequentially provided with a first inner valley 81, a second inner valley 82 and a third inner valley 83 in the direction extending from the straight cutting edge 51 to the third cutting edge 53 on the same side, the maximum depths of the first inner valley 81, the second inner valley 82 and the third inner valley 83 are H1, H2 and H3, respectively, and in order to ensure that when the insert body 1 is used as an inner edge and an outer edge of a drilling tool for cutting, the critical wavy line 23 has a precise chip curling radius and does not form a wear groove, the following requirements should be satisfied: h3+0.01D is not less than H1 and not more than H2-0.01D. In this example, D =7mm, H1=1.1mm, H2=1.2mm, H3=1 mm.

In the direction of the upper surface 2, the waveform cutting edge 52 is provided with a first wave trough 71, a second wave trough 72 and a third wave trough 73 in sequence in the direction extending from the straight cutting edge 51 to the third cutting edge 53 on the same side, the included angles between the wave teeth on the two sides of the first wave trough 71, the second wave trough 72 and the third wave trough 73 are respectively alpha 1, alpha 2 and alpha 3, in order to ensure that the waveform cutting edge 52 has better strength and stronger impact resistance, the cutting is light and fast, and has very excellent chip breaking and chipping capabilities, and the problem that the cutting of the first wave trough 71, the second wave trough 72 and the third wave trough 73 generates periodic vibration is avoided, and the following requirements are met: α 2 is not less than 150 ° ≦ α 3-3 ° ≦ α 2 ≦ α 1-3 ° ≦ 178 °, in this example, α 1=160 °, α 2=165 °, α 3=170 °.

In the present embodiment, the side surface 4 comprises a major side surface 41 and a corner surface 42 corresponding to the major cutting edge 5 and the corner cutting edge 6, respectively, the major side surface 41 comprises a first major side surface 411 adjacent to the upper surface 2, a second major side surface 412 adjacent to the lower surface 3, and a transition side surface 413 between the first major side surface 411 and the second major side surface 412, the first major side surface 411 comprises a first straight side surface 4111, a first wave side surface 4112, and a first short side surface 4113 corresponding to the straight cutting edge 51, the wave cutting edge 52, and the third cutting edge 53, respectively, the second major side surface 412 comprises a second straight side surface 4121, a second wave side surface 4122, and a second short side surface 4123 corresponding to the straight cutting edge 51, the wave cutting edge 52, and the third cutting edge 53, respectively, and the transition side surface 413 contacts the first straight side surface 4111, the first wave side surface 4112, the first short side surface 4113, and the second wave side surface 4122, respectively. In this embodiment, the relief angle of the first straight side surface 4111 is γ 1, the relief angle of the first wavy side surface 4112 is γ 2, and the relief angle of the second wavy side surface 4122 is γ 3, so as to reduce the wear amount of the first straight side surface 4111 corresponding to the linear cutting edge 51, ensure the strength of the wavy cutting edge 52, and improve the dimensional stability of the third cutting edge 53 during the cutting process, which should satisfy: gamma 3-gamma 2 is more than or equal to 2 degrees and less than or equal to 6 degrees, and gamma 1-gamma 3 is more than or equal to 2 degrees and less than or equal to 6 degrees. In the present embodiment, γ 1=15 °, γ 2=11 °, γ 3=9 °.

In this embodiment, the wave crests and the wave troughs of the waveform units of the waveform cutting edge 52 are both arc-shaped, and the wave teeth 73 are linear, so that the waveform cutting edge 52 formed by straight lines and arcs is easy to manufacture and detect, the manufacturing difficulty of the cutting blade die is effectively reduced, and the manufacturing precision of the die is improved.

In this embodiment, the center of the insert body 1 is provided with a center hole 9 penetrating through the upper surface 2 and the lower surface 3, and the insert body 1 is symmetrical about an axis 10 of the center hole 9, so that the manufacturing and installation of the cutting insert are facilitated.

In this embodiment, in order to assist the concave side 43 of avoiding blade body 1 to warp and cause the positional stability to exert an influence, the middle part of side 4 is equipped with concave side 43, the accurate positioning of the blade body 1 of being convenient for.

In the above embodiment, the third cutting edge 53 is a straight cutting edge, and the third cutting edge 53 may be designed as an arc-shaped cutting edge with a curvature radius R1 according to application requirements, so as to further improve the quality of the machined surface and reduce the cutting vibration, it should be satisfied that: r is more than or equal to 20mm and less than or equal to 50 mm; for example, R =40 mm.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make numerous possible variations and modifications to the present invention, or modify equivalent embodiments to equivalent variations, without departing from the scope of the invention, using the teachings disclosed above. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention should fall within the protection scope of the technical scheme of the present invention, unless the technical spirit of the present invention departs from the content of the technical scheme of the present invention.

Claims

1. The utility model provides a cutting insert for spot facing work, includes the blade body (1) that is the quadrangle platelike, blade body (1) is enclosed by upper surface (2), lower surface (3) and side (4) connecting upper surface (2) and lower surface (3), side (4) and upper surface (2) intersect and form four main cutting edge (5) and four corner cutting edge (6) that are located between adjacent main cutting edge (5), its characterized in that: the upper surface (2) comprising a central plane (22) in a central region and a groove profile (21) at the periphery of the central plane (22), the groove profile (21) comprises a groove front surface (211), a groove rear surface (212) and a groove bottom surface (213) positioned between the groove front surface (211) and the groove rear surface (212), the flute leading face (211) being adjacent to the main cutting edge (5) and the corner cutting edge (6), the groove back surface (212) is adjacent to the central surface (22), the main cutting edge (5) comprises a straight cutting edge (51) and a waveform cutting edge (52), the groove back surface (212) and the central surface (22) which correspond to the same main cutting edge (5) are intersected to form a waveform critical line (23), in the direction of the upper surface (2), the amplitude of the waveform critical line (23) is larger than the amplitude of the waveform cutting edge (52).

2. The cutting insert for hole machining according to claim 1, wherein: in the direction of the upper surface (2), the maximum amplitude of the waveform critical line (23) is H, the maximum amplitude of the waveform cutting edge (52) is H, and the following conditions are satisfied: h is more than or equal to 7H and less than or equal to 13H.

3. The cutting insert for hole machining according to claim 1, wherein: the wave form cutting edge (52) are located straight line cutting edge (51) place straight line is close to the inside one side of blade body (1), be equipped with third cutting edge (53) between wave form cutting edge (52) and adjacent corner cutting edge (6), two relatively distance between straight line cutting edge (51) is L1, two relatively distance between third cutting edge (53) is L2, four wave form cutting edge (52) have common inscribed circle and inscribed circle diameter and be D, should satisfy: l2 is more than or equal to 1.02D and less than or equal to L1 and less than or equal to 1.2D.

4. The cutting insert for hole machining according to claim 3, wherein: in the direction of the upper surface (2), the wave-shaped critical line (23) is provided with a first inner wave trough (81), a second inner wave trough (82) and a third inner wave trough (83) in sequence in the direction extending from the straight cutting edge (51) on the same side to the third cutting edge (53), the maximum depths of the first inner wave trough (81), the second inner wave trough (82) and the third inner wave trough (83) are respectively H1, H2 and H3, and the following requirements are met: h3+0.01D is not less than H1 and not more than H2-0.01D.

5. The cutting insert for hole machining according to claim 3, wherein: on upper surface (2) direction, wave form cutting edge (52) are equipped with first trough (71), second trough (72) and third trough (73) in proper order in the direction that extends to third cutting edge (53) from straight line cutting edge (51) of homonymy, the contained angle between the wave tooth of first trough (71), second trough (72), third trough (73) both sides is alpha 1, alpha 2, alpha 3 respectively, should satisfy: alpha 2 is more than or equal to 150 degrees and more than or equal to 3 degrees and more than or equal to alpha 2 is more than or equal to 1 degrees and more than or equal to 3 degrees and more than or equal to 178 degrees.

6. The cutting insert for hole machining according to claim 3, wherein: the side surface (4) comprises a main side surface (41) and a corner surface (42) corresponding to the main cutting edge (5) and the corner cutting edge (6), respectively, the main side surface (41) comprises a first main side surface (411) adjacent to the upper surface (2), a second main side surface (412) adjacent to the lower surface (3) and a transition side surface (413) between the first main side surface (411) and the second main side surface (412), the first main side surface (411) comprises a first straight side surface (4111), a first wave side surface (4112) and a first short side surface (4113) corresponding to the straight cutting edge (51), the wave cutting edge (52) and the third cutting edge (53), respectively, the second main side surface (412) comprises a second straight side surface (4121), a second wave side surface (4122) and a second short side surface (4123) corresponding to the straight cutting edge (51), the wave cutting edge (52) and the third cutting edge (53), respectively, the transition side surface (413) is in contact with the first straight side surface (4111), the first wave side surface (4112), the first short side surface (4113) and the second wave side surface (4122), respectively.

7. The cutting insert for hole machining according to claim 6, wherein: the relief angle of the first straight side surface (4111) is γ 1, the relief angle of the first wavy side surface (4112) is γ 2, and the relief angle of the second wavy side surface (4122) is γ 3, which satisfy the following requirements: gamma 3-gamma 2 is more than or equal to 2 degrees and less than or equal to 6 degrees, and gamma 1-gamma 3 is more than or equal to 2 degrees and less than or equal to 6 degrees.

8. The cutting insert for hole machining according to claim 3, wherein: the length of the third cutting edge (53) is X and satisfies the following conditions: x is more than or equal to 0.2mm and less than or equal to 1.2 mm.

9. The cutting insert for hole machining according to claim 8, wherein: the third cutting edge (53) is a linear cutting edge, and the included angle between the third cutting edge (53) and the linear cutting edge (51) in the main cutting edge (5) corresponding to the third cutting edge (53) is beta, which satisfies the following conditions: beta is more than or equal to 5 degrees and less than or equal to 20 degrees.

10. The cutting insert for hole machining according to claim 8, wherein: the third cutting edge (53) is an arc-shaped cutting edge, the curvature radius of the third cutting edge (53) is R1, and the following conditions are met: r1 is more than or equal to 20mm and less than or equal to 50 mm.