Anastomat

Abstract

The invention provides an anastomat which comprises a nailing structure, a plurality of fixing structures and a plurality of fixing structures, the nailing structure comprises a plurality of anastomosis nails, and the anastomosis nails are distributed in the target direction of the nailing structure; the cutting assembly comprises a cutting knife body and a cutting knife head, a blade part is arranged on the cutting knife head, and the cutting knife head is movably connected to the cutting knife body; the driving mechanism is connected with the cutting knife body; during cutting, the driving mechanism drives the cutting assembly to move in the target direction; and meanwhile, the cutting tool bit generates angular displacement in the target direction. The angular displacement of the cutting tool bit improves the cutting effect, the target cutting tissue is prevented from being torn under the pressure of the cutting tool bit, the damage to the blade part in the cutting process is reduced, and the safety in the operation process is improved.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to a stapler. Background Art

[0002] The surgical stapler is a minimally invasive surgical instrument commonly used in surgery. It replaces traditional manual suturing and is mainly used for organ stump sealing and incision anastomosis in minimally invasive surgical treatment.

[0003] The existing staplers also include a cutting function, which can cut tissues while suturing. The cutting method of the cutting knife in the existing staplers is to set a blade on the head, and the blade extrudes and cuts the tissues under the action of external force, but this cutting method causes great damage to the blade, which can easily cause the blade to break and curl, affecting the sharpness of the blade. In addition, the extrusion cutting method pulls the tissues during the cutting process. If the blade is defective, it will aggravate the extrusion of the cutting knife. When the cutting knife reaches the yield strength limit, it will cause the blade to curl and break, causing serious medical accidents.

[0004] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the application and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a stapler to solve the problem that the blade of the stapler is easily damaged during cutting, reduce the risk of medical accidents caused by the cutting knife, and improve the cutting effect.

[0006] To achieve the above-mentioned purpose, the present application provides a stapler, comprising: a stapling structure, the stapling structure comprising a plurality of staples, the plurality of staples being distributed along the target direction; the target direction being the length direction of the stapling structure;

[0007] The cutting assembly comprises a cutting blade body and a cutting blade head, wherein the cutting blade head is provided with a blade portion and the cutting blade head is movably connected to the cutting blade body;

[0008] A driving mechanism connected to the cutting blade;

[0009] During cutting, the driving mechanism drives the cutting assembly to move along the target direction; at the same time, the cutting head generates an angular displacement in the target direction.

[0010] In one or more embodiments, the stapler is characterized in that it further comprises:

[0011] A first transmission assembly is connected to the cutting head, and the cutting head generates a unidirectional angular displacement in the target direction.

[0012] In one or more embodiments, the first transmission assembly includes:

[0013] A gear, the gear is connected to the cutting head and rotates about the same rotation center;

[0014] A rack is meshed with the gear, the driving mechanism drives the cutting blade to move along the target direction, the cutting blade drives the cutting head to move linearly along the rack, and the cutting head rotates at the same time.

[0015] In one or more embodiments, the first transmission assembly further includes:

[0016] A first motor is connected to the cutting head and drives the cutting head and the cutting blade to generate a unidirectional angular displacement in the target direction.

[0017] In one or more embodiments, the rack is mounted within the stapling structure along the target direction.

[0018] In one or more embodiments, the cutting blade comprises:

[0019] A mounting portion, wherein the end of the cutting blade body is provided with a mounting portion, and the mounting portion is provided with a through hole;

[0020] The cutting structure further includes: a connecting pin, a mounting hole is provided in the axial direction of the cutting head, and the connecting pin passes through the mounting hole and the through hole.

[0021] In one or more embodiments, the cutting assembly includes two cutting heads, and the two cutting heads are symmetrically arranged along the cutting blade body;

[0022] The two cutting heads are arranged in parallel and a cutting gap is formed between the two cutting heads;

[0023] The first transmission assembly drives the two cutting heads to move synchronously.

[0024] In one or more embodiments, the cutting blade head and the cutting blade body are connected with each other by clearance fit.

[0025] In one or more embodiments, the stapler further comprises:

[0026] handle;

[0027] an outer tube, one end of which is connected to the handle, and the other end of which is connected to the stapling structure;

[0028] The driving structure comprises a second motor and a third transmission assembly, wherein the second motor is connected to one end of the third transmission assembly, and the other end of the third transmission assembly is connected to the cutting assembly;

[0029] The second motor is located inside the handle, and the third transmission assembly and the cutting assembly are located inside the outer tube.

[0030] In one or more embodiments, the cutting angle of the cutting edge is 15°-20°.

[0031] Compared with the prior art, the stapler according to the present application has the following advantages:

[0032] The cutting blade and the cutting head are driven to move along the target direction by a driving mechanism, and staples are distributed in the target direction of the stapling structure. The cutting assembly cuts the target cutting tissue along the target direction and staples the target cutting tissue together. During the process, the cutting head is angularly displaced in the target direction, that is, the cutting head makes a linear displacement while making an angular cut, which can improve the cutting effect, avoid the target cutting tissue from being torn under the pressure of the cutting head, reduce the damage to the blade during the cutting process, and improve the safety during the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a partial structural schematic diagram of a stapler according to an embodiment of the present application;

[0034] Figure 2 yes Figure 1 Cross-sectional view at AA in the middle;

[0035] Figure 3 is a schematic diagram of a partial internal structure of a stapler according to an embodiment of the present application;

[0036] Figure 4 Figure 3 Enlarged view of point E in the middle;

[0037] Figure 5 is a partial structural diagram of a cutting assembly of a stapler according to an embodiment of the present application;

[0038] Figure 6 is a side view of a cutting blade according to an embodiment of the present application;

[0039] Figure 7 is a schematic structural diagram of a cutting blade according to an embodiment of the present application;

[0040] Figure 8 is a schematic structural diagram of a cutting assembly of a stapler according to an embodiment of the present application;

[0041] Fig. 9 yes Figure 8 Cross-section at the middle BB;

[0042] Fig.10 is a partial structural schematic diagram of a driving structure of a stapler according to an embodiment of the present application;

[0043] Fig.11 is a partial structural schematic diagram of a stapling structure according to an embodiment of the present application;

[0044] Fig.12 yes Fig.11 Cross-section at CC;

[0045] Fig.13 It is a schematic diagram of the internal structure of the stapler according to one embodiment of the present application.

[0046] Description of main reference numerals:

[0047] 1. Stapler; 10. Cutting structure; 2. Cutting assembly; 21. Cutting blade; 211. Mounting portion; 212. Mounting hole; 213. Connecting pin; 22. Cutting head; 221. Blade portion; 222. Through hole; 223. Protrusion; 30. Driving mechanism; 31. Gear; 32. Rack; 33. Second motor; 34. Screw; 35. Threaded sleeve; 36. Transmission rod; 361. Matching portion; 4. Stapling structure; 41. Staples; 42. Staple magazine seat; 421. Push knife groove; 43. Staple support seat; 5. Handle; 6. Outer tube. DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific implementation methods and with reference to the accompanying drawings.

[0049] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0050] like Figure 1 , Figure 2 , Figure 5 and Figure 8 As shown, a stapler 1 according to an embodiment of the present application includes: a stapling structure 4 and a cutting assembly 2, the stapling structure 4 includes a plurality of staples 41, and the plurality of staples 41 are distributed along a target direction, the target direction being the length direction of the stapling structure 4, during the operation of the stapler 1, the target direction of the stapling structure 4 is aligned with the target cutting tissue, the cutting assembly 2 cuts the target cutting tissue in the target direction, and the plurality of staples 41 close the target cutting tissue along the target direction, completing one operation of the stapler 1. The X direction in the figure is the target direction.

[0051] The cutting assembly 2 includes a cutting blade body 21 and a cutting head 22 . The cutting head 22 is provided with a blade portion 221 . The cutting head 22 is movably connected to the cutting blade body 21 , so that the cutting head 22 can move with the cutting blade body 21 or make relative motion with the cutting blade body 21 .

[0052] The stapler 1 further includes a driving mechanism 30, which is connected to the cutting blade body 21. When cutting, the driving mechanism 30 drives the cutting assembly 2 to move in the target direction, and at the same time, the cutting blade head 22 and the cutting blade body 21 produce angular displacement in the target direction. The cutting blade head 22 moves on the target cutting tissue and makes angular displacement during the movement process to achieve cutting of the target cutting tissue.

[0053] During the operation of the stapler 1, the cutting head 22 simultaneously moves in a straight line in the target direction of the staple structure 4, and the blade 221 on the cutting head 22 has an angular displacement relative to the target direction, thereby completing the cutting, and during the cutting process, the staples 41 merge the cutting positions. The angular displacement of the cutting head 22 generates an angular cutting force, which can improve the cutting effect compared to the extrusion cutting force in the prior art, avoid the target cutting tissue from being torn under the extrusion cutting force of the cutting head 22, and reduce the damage to the blade 221 during the cutting process, thereby improving the safety during the operation.

[0054] like Figure 5 and Fig. 9As shown, in a specific embodiment, the cutting assembly 2 includes two cutting heads 22, the two cutting heads 22 are symmetrically arranged along the cutting blade body 21, the two cutting heads 22 are arranged in parallel and a cutting gap is formed between the two cutting blades. The cutting blade body 21 is located between the two cutting heads 22, and the blade portion 221 of the cutting head 22 facing the target direction needs to exceed the projection area of ​​the cutting blade body 21 in order to apply a cutting force to the target cutting tissue, so the two cutting heads 22 have an excess portion that exceeds the projection area of ​​the cutting blade body 21, and a cutting gap is formed between the excess portions of the two cutting heads 22.

[0055] It should be noted that during the entire cutting process, a high requirement is placed on the tensile strength of the cutting head 22. When the material of the cutting head 22 is fixed, the thicker the cutting head 22, the higher the tensile strength. For example, if the blade 221 of the cutting head 22 is located in the middle of the cutting head 22, the thickness of the cutting head 22 needs to increase with the length of the blade 221, which will take up a large amount of space, increase the manufacturing difficulty, and form a stress concentration point at the tip of the blade 221. From the cutting head 22 body to the tip of the blade 221, the thickness of the cutting head 22 decreases sharply, which reduces the tensile performance and makes the cutting head 22 prone to breakage. Therefore, two cutting heads 22 are provided, symmetrically arranged on both sides of the cutting blade body 21, and a thinner cutting head 22 is used, with the blade 221 distributed on the edge of the cutting head 22, to ensure that the cutting head 22 meets the tensile performance and to ensure the balance of force applied during the cutting process.

[0056] In a specific embodiment, the cutting angle of the cutting edge 221 is 15°-20°.

[0057] Conventional cutting knives for extrusion cutting need to consider not only sharpness but also the tensile strength and durability of the blade, so the angle of the blade is relatively large. In this embodiment, the angular displacement cutting method increases the durability of the blade, so the angle of the blade can be reduced as much as possible to obtain better sharpness. After experiments, the blade angle is set to 15°-20°, which has good sharpness and durability.

[0058] Specifically, the cutting angle of the blade may be 15°, 16°, 18° or 20°.

[0059] In a specific embodiment, the relative surfaces of the cutting blade body 21 and the cutting head 22 are connected with each other in a clearance fit, so as to ensure that the cutting head 22 can freely move relative to the cutting blade body 21 .

[0060] In a specific embodiment, Figure 8 and Fig. 9As shown, a mounting portion 211 is provided on the cutting blade body 21, a mounting hole 212 is opened on the mounting portion 211, and a through hole 222 is provided in the axial direction of the cutting head 22. A connecting pin 213 is passed through the mounting hole 212 and the through hole 222 to realize a movable connection between the cutting blade body 21 and the cutting head 22, thereby ensuring that when the cutting blade body 21 moves, the cutting head 22 moves with the cutting blade body 21, and the cutting head 22 can also make angular displacement relative to the cutting blade body 21.

[0061] In order to achieve angular cutting of the cutting head 22, in a specific embodiment, a first transmission assembly is further included, the first transmission assembly is connected to the cutting head 22, and the cutting head 22 and the cutting blade body 21 generate a unidirectional angular displacement in the target direction. The cutting head 22 continuously performs angular cutting on the target cutting tissue through the unidirectional angular displacement, thereby ensuring the continuity of the angular cutting of the cutting assembly 2 during the straight-line movement and improving the cutting efficiency.

[0062] In a specific embodiment, if Figure 3 , Figure 4 As shown, the first transmission assembly includes a gear 31 and a rack 32, and the driving mechanism 30 is connected to the cutting blade 21. The driving mechanism 30 drives the cutting blade 21 and the cutting head 22 to make linear motion along the target direction. The cutting head 22 is connected to the gear 31 and rotates with the same rotation center. The cutting head 22 and the gear 31 move synchronously. When the cutting head 22 moves linearly, it drives the gear 31 to move linearly. At the same time, the gear 31 is also meshed with the rack 32, so the gear 31 moves linearly along the rack 32. In this process, due to the meshing of the gear 31 and the rack 32, the gear 31 rotates itself, and the gear 31 drives the cutting head 22 to rotate together, thereby realizing angular cutting of the cutting head 22.

[0063] By utilizing the meshing of the gear 31 and the rack 32, the cutting head 22 can simultaneously perform linear motion and rotation, and 36 does not require additional power input, thereby converting the extrusion cutting into angular cutting, improving the cutting effect, avoiding damage to the blade 221 during surgery, and improving safety during surgery.

[0064] Furthermore, the axis of the gear 31 coincides with the axis of the cutting head 22, so that the cutting head 22 and the gear 31 rotate at the same angular velocity. The rotation speed of the cutting head 22 can be controlled by setting data such as the number of teeth and / or module of the control gear 31 and the rack 32.

[0065] Further, such as Figure 6 and Figure 7 As shown, the side of the gear 31 is fitted with the side of the cutting head 22, and the gear 31 and the cutting head 22 are fixedly connected by welding or bonding, or the gear 31 and the cutting head 22 are an integrated structure.

[0066] In a specific embodiment, the two cutting heads 22 are symmetrically arranged on both sides of the cutting body 21, and the gear 31 is arranged on the side of the cutting head 22 away from the cutting body 21. Therefore, the rack 32 is also arranged on the side of the cutting head 22 away from the cutting body 21. When the cutting body 21 moves along the rack 32, it does not interact with the rack 32, thereby ensuring the stability of the moving process.

[0067] In a specific embodiment, the rack 32 is installed in the stapling structure 4 and arranged along the target direction of the stapling structure 4, so that the gear 31 meshing therewith moves straight along the target direction, thereby improving the integration of the stapler 1.

[0068] In another specific embodiment, the first transmission assembly includes a first motor, which is connected to the cutting head 22 and drives the cutting head 22 and the cutting blade 21 to generate a unidirectional angular position with respect to the target direction.

[0069] The driving mechanism 30 is used as the driving source for the linear motion of the cutting head 22, and the first motor is used as the driving source for the rotation of the cutting head 22. The rotation speed of the cutting head 22 can be controlled independently, and it has good adaptability when cutting target cutting area tissues with different hardness and structure.

[0070] In order to achieve angular cutting of the cutting head 22, in another specific embodiment, the driving mechanism 30 further includes a second transmission assembly, which is connected to the cutting head 22, and the cutting head 22 and the cutting blade 21 generate reciprocating angular displacement in the target direction. The blade 221 of the cutting head 22 performs the cutting process by repeatedly moving on the target cutting tissue.

[0071] In a specific embodiment, the second transmission assembly includes a toothed portion and a driving gear 31. The toothed portion is arranged at one end of the cutting head 22, and a blade portion 221 is arranged at the other end of the cutting head 22. The driving gear 31 is engaged with the toothed portion. The driving gear 31 rotates back and forth, and the toothed portion engaged with it also moves repeatedly on the driving gear 31. The cutting head 22 is hinged to the cutting blade 21. When the toothed portion rotates repeatedly, the cutting head 22 repeatedly swings in the direction with the hinge point as the center, so that the blade portion 221 makes reciprocating angular displacement.

[0072] Specifically, the third motor is used to make the driving gear 31 move back and forth, or a handle is provided, the handle is connected to the driving gear 31, and the operator manually controls the reciprocating movement of the handle.

[0073] In one or more embodiments, Fig.13As shown, the stapler 1 further includes a handle 5 and an outer tube 6, one end of the outer tube 6 is connected to the handle 5, and the other end of the outer tube 6 is connected to the stapling structure 4. The driving mechanism 30 includes a second motor 33 and a third transmission assembly, the second motor 33 is connected to one end of the third transmission assembly, and the other end of the third transmission assembly is connected to the cutting assembly 2, the second motor 33 is located inside the handle 5, and the third transmission assembly and the cutting assembly 2 are located inside the outer tube 6.

[0074] In a specific embodiment, Figure 8 and Fig.10 As shown, the third transmission assembly includes a screw rod 34, a threaded sleeve 35 and a transmission rod 36, the second motor 33 is connected to the threaded sleeve 35, the threaded sleeve 35 is sleeved on the screw rod 34 and cooperates with the thread of the screw rod 34, the second motor 33 drives the threaded sleeve 35 to rotate, the threaded sleeve 35 drives the screw rod 34 to move linearly, and the screw rod 34 drives the transmission rod 36 to move linearly; the driving mechanism 30 also includes a screw, one end of the screw rod 34 is provided with an expansion portion, one end of the transmission rod 36 is provided with a recess, the expansion portion is sleeved with the recess, the screw passes through the side walls of the expansion portion and the recess, so that the screw rod 34 is fixedly connected to the transmission rod 36; the other end of the transmission rod 36 is provided with a matching portion 361, one end of the cutting blade 21 is provided with a protrusion 223, the matching portion 361 and the protrusion 223 are engaged, so that the transmission rod 36 and the cutting blade 21 are fixedly connected in the linear movement direction, and the transmission rod 36 drives the cutting blade 21 to move linearly. Under electric drive, the cutting component 2 realizes the cutting process on the target cutting tissue, with a simple structure and high reliability.

[0075] During the cutting process, cutting is applied from the starting point to the end point of the expected cutting trajectory of the target cutting tissue. Driven by the second motor 33, the cutting blade 21 moves from the starting point to the end point, and the cutting head 22 that moves therewith performs cutting.

[0076] In a specific embodiment, Figure 1 , Figure 2 , Fig.11 and Fig.12 As shown, the staple structure 4 includes a plurality of staples 41, a staple cartridge seat 42 and a staple anvil seat 43. The staple cartridge seat 42 is provided with a plurality of staple grooves for placing the staples 41. A pusher groove 421 is provided along the length direction of the staple cartridge seat 42. The staple cartridge seat 42 can move toward the staple anvil seat 43 to clamp and fix the target cutting tissue. The cutting blade body 21 and the cutting blade head 22 can move along the pusher groove 421. Fig.11 and Fig.12 The X direction shown in is the target direction.

[0077] The stapler 1 also includes a staple pushing mechanism, which includes a staple pushing plate. The staple pushing plate is connected to one end of the cutting assembly 2 close to the cutting head 22. When the cutting assembly 2 and the staple pushing plate move along the staple pushing groove 421, the staples 41 are pushed out of the staple groove.

[0078] During the use of the stapler 1, first, the staple magazine seat 42 and the staple support seat 43 fix the target cutting tissue in the target direction, determine the cutting direction of the tissue as the target direction, and point the cutting component 2 in the cutting structure 10 toward the target direction, drive the cutting blade 21 and the cutting head 22 to move along the target direction, and at the same time, the cutting head 22 makes an angular displacement toward the target direction to achieve cutting of the target cutting tissue. During the cutting process, the staple pusher plate moves in a straight line with the cutting component 2, and interacts with the stapler 41 during the movement, thereby pushing the stapler 41, causing the stapler 41 to emerge from the staple groove, closing the fixed target cutting tissue, and achieving the purpose of removing the lesion.

[0079] In a specific embodiment, the staples 41 are parallel to the height direction of the staple cartridge seat 42, and the staple slot is a structure that is open from top to bottom, and a portion of the staples 41 is exposed at the bottom portion of the lower portion of the staple slot. With the advancing direction during the staple operation as the front end, the staple pusher plate includes a sloped plate surface, the height of which gradually increases from the front end to the rear end, and when the staple pusher plate advances, the sloped plate surface lifts the staples 41, thereby pushing the staples 41 out of the staple slot.

[0080] In a specific embodiment, the stapler 1 also includes a body, the stapling structure 4 is installed at the operating end of the body, the cutting assembly 2 and part of the driving mechanism 30 are located inside the body near the operating end, and during the cutting process, the driving mechanism 30 drives the cutting assembly 2 to move from the inside of the body to the stapling structure 4, and the cutting head 22 is located at the end of the cutting body 21 closer to the stapling structure 4, and the cutting head 22 performs cutting at the front end of the moving direction of the cutting assembly 2.

[0081] The foregoing description of the specific exemplary embodiments of the present application is for the purpose of illustration and illustration. These descriptions are not intended to limit the present application to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present application and its practical application, so that those skilled in the art can realize and utilize the various exemplary embodiments of the present application and various selections and changes. The scope of the present application is intended to be limited by the claims and their equivalents.

Claims

1. A stapler, characterized in that: include: A stapling structure, wherein the stapling structure comprises a plurality of staples, and the plurality of staples are distributed along a target direction; The target direction is the length direction of the stapling structure; The cutting assembly comprises a cutting blade body and a cutting blade head, wherein the cutting blade head is provided with a blade portion and the cutting blade head is movably connected to the cutting blade body; A driving mechanism connected to the cutting blade; During cutting, the driving mechanism drives the cutting assembly to move along the target direction; at the same time, the cutting head generates an angular displacement in the target direction.

2. The stapler according to claim 1, characterized in that: Also includes: A first transmission assembly is connected to the cutting head, and the cutting head generates a unidirectional angular displacement in the target direction.

3. The stapler according to claim 2, characterized in that: The first transmission assembly comprises: A gear connected to the cutting head and rotating about the same rotation center; A rack is meshed with the gear, the driving mechanism drives the cutting blade to move along the target direction, the cutting blade drives the cutting head to move linearly along the rack, and the cutting head rotates at the same time.

4. The stapler according to claim 2, characterized in that: The first transmission assembly also includes: A first motor is connected to the cutting head and drives the cutting head and the cutting blade to generate a unidirectional angular displacement in the target direction.

5. The stapler according to claim 3, characterized in that: The rack is installed in the stapling structure along the target direction.

6. The stapler according to claim 1, characterized in that: The cutting blade comprises: A mounting portion, wherein the end of the cutting blade body is provided with a mounting portion, and the mounting portion is provided with a through hole; The cutting structure further includes: a connecting pin, a mounting hole is provided in the axial direction of the cutting head, and the connecting pin passes through the mounting hole and the through hole.

7. The stapler according to claim 2, characterized in that: The cutting assembly comprises two cutting heads, and the two cutting heads are symmetrically arranged along the cutting blade body; The two cutting heads are arranged in parallel and a cutting gap is formed between the two cutting heads; The first transmission assembly drives the two cutting heads to move synchronously.

8. The stapler according to claim 7, characterized in that: The opposing surfaces of the cutting blade head and the cutting blade body are connected by clearance fit.

9. The stapler according to claim 1, characterized in that: Also includes: handle; an outer tube, one end of which is connected to the handle, and the other end of which is connected to the stapling structure; The driving structure comprises a second motor and a third transmission assembly, wherein the second motor is connected to one end of the third transmission assembly, and the other end of the third transmission assembly is connected to the cutting assembly; The second motor is located inside the handle, and the third transmission assembly and the cutting assembly are located inside the outer tube.

10. The stapler according to claim 1, characterized in that: The cutting angle of the cutting edge is 15°-20°.

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