Self-locking type double-edge slitting lower knife

Abstract

The utility model discloses a self-locking type double-edge slitting lower cutter which comprises a lower cutter body with a center hole, slitting cutting edges are arranged on the two end faces of the lower cutter body respectively, and a self-locking positioning structure used for locking and positioning is arranged on the lower cutter body in the radial direction. According to the self-locking type double-edge slitting lower knife, double slitting cutting edges are adopted, slitting can be achieved at the two ends in the using process, the problems that a single-side cutting edge is short in service life and high in cost are solved, meanwhile, a self-locking positioning structure is arranged on the lower knife body, when the slitting thickness needs to be adjusted, the lower knife body can be moved in the axial direction to be adjusted by unlocking the self-locking positioning structure, and the slitting thickness is adjusted. Operation is convenient and fast, efficiency is high, the slitting requirements of different thicknesses can be met, and the application range is wide.

Description

Technical Field

[0001] The utility model belongs to the technical field of slitting tools, and particularly relates to a self-locking double-edge slitting lower knife. Background Art

[0002] For existing slitting tools, the slitting upper knife and the slitting lower knife cooperate to achieve slitting. However, the following problems exist in the use process:

[0003] The slitting lower knife needs to be positioned by a spacer (gasket) for slitting, resulting in high production costs. Moreover, the slitting thickness is fixed and cannot meet the requirements of slitting the cut material with different slitting thicknesses. At the same time, since the existing slitting lower edge adopts a single-sided slitting edge, the service life of the tool is short. Due to the need for spacer and the thickness of the tool body itself for positioning, extremely high precision requirements are imposed on the width of the tool and the spacer, resulting in low installation efficiency of the slitting knife.

[0004] Therefore, there is an urgent need to design a slitting lower knife that can achieve online adjustment of the slitting width and has a long service life. Summary of the Utility Model

[0005] The purpose of the utility model is to solve the problems that the slitting lower knife is positioned by a spacer or an axial gasket, after the slitting lower knife is installed, the slitting thickness cannot be adjusted, the requirements of slitting with different thicknesses cannot be met, and it is time-consuming and material-consuming to disassemble and assemble all the slitting lower knives and replace the spacer or the axial gasket to adjust the thickness, resulting in low production efficiency. At the same time, the single-sided slitting edge has few grinding times, short service life, and high costs. The utility model provides a self-locking double-edge slitting lower knife that can meet the online adjustment of the slitting thickness without disassembling the slitting lower knife, is convenient and fast to operate, has high production efficiency, has double slitting edges on the slitting lower knife, has a long service life, and low costs.

[0006] The technical solution adopted by the utility model to achieve its invention purpose is: a self-locking double-edge slitting lower knife, including a lower knife body with a central hole, slitting edges are respectively arranged on both end faces of the lower knife body, and a self-locking positioning structure for locking and positioning is arranged in the radial direction of the lower knife body. For this self-locking double-edge slitting lower knife, by arranging slitting edges at both ends of the lower knife body, slitting can be achieved at both ends during the use process, solving the problems of short service life and high cost of the single-sided edge. At the same time, setting double slitting edges can avoid disassembling the lower knife body during use, but instead reversely use the whole tool shaft, which is convenient and fast to operate, saves tool changing time, and greatly improves production efficiency. In order to meet the online adjustment of the slitting thickness without disassembling the lower knife body, a self-locking positioning structure is arranged on the lower knife body. When it is necessary to adjust the slitting thickness, unlock the self-locking positioning structure, and then the lower knife body can be axially moved for adjustment. After adjustment, lock the self-locking positioning structure to lock and position the adjusted position. The operation is convenient and fast, with high efficiency, can meet the requirements of slitting with different thicknesses, and has a wide application range.

[0007] Preferably, the slitting edge is provided on the outer circumference of both end faces of the lower knife body, and a blade angle is formed between the slitting edge and the radial direction of the lower knife body. The slitting edge is provided on the outer circumference of both ends of the lower knife body to cooperate with the upper slitting knife to achieve slitting. The blade angle is formed between the slitting edge and the radial direction of the lower knife body, that is, the vertical direction. The setting of the blade angle is to meet the slitting requirements of different materials.

[0008] Preferably, an annular chip removal groove is provided on the end face of the lower knife body between the slitting edge and the central hole; the blade angle is inclined from the outer circumference of the lower knife body to the bottom of the chip removal groove. The chip removal groove is provided at the slitting edge to achieve chip accommodation and heat dissipation during the slitting process, and improve the service life of the lower knife body. The blade angle is inclined from the outer circumference of the lower knife body to the chip removal groove, which can improve the sharpness of the blade edge and meet the material slitting requirements.

[0009] Preferably, the slitting edges at both ends of the lower knife body are symmetrically arranged, and the blade angles of the slitting edges at both ends are the same, and the blade angles are 3-5° respectively. As a preferred solution, the slitting edges at both ends of the lower knife body are symmetrically arranged and the blade angles are the same. In this structure, when in use, the lower knife body does not need to consider the direction during installation and can be directly installed. When the online integral tool shaft is reversed, the same material can be slit with the same thickness. The setting of the blade angle satisfies both sharpness and slitting strength.

[0010] Preferably, the slitting edges at both ends of the lower knife body are asymmetrically arranged, and the blade angles of the slitting edges at both ends of the lower knife body are different from each other. The slitting edges at both ends of the lower knife body can also be arranged in an asymmetric structure, and the blade angles of the slitting edges can be set to different angles. The tool shaft can be used as a whole after being reversed, and the slitting requirements of different materials with different thicknesses can be achieved.

[0011] Preferably, the self-locking positioning structure includes a locking groove provided at the middle position of the central hole, an elastic locking piece provided inside the locking groove, a locking hole provided on the circumference of the lower knife body, and a locking piece provided inside the locking hole. The self-locking positioning structure mainly includes a locking groove provided inside the lower knife body. An elastic locking piece is provided inside the locking groove, and then a radial locking hole is provided on the lower knife body. The elastic locking piece is radially pressed through the locking piece inside the locking hole, so as to lock the lower knife body on the tool shaft. The lower knife body is fixed relative to the tool shaft and axially slides, so that the adjustment of the slitting thickness can be effectively achieved. Of course, other methods can also be adopted for the self-locking positioning structure, such as setting an elastic self-locking piece inside the locking groove, and cooperating with the tool shaft to lock through the elasticity of the elastic self-locking piece itself.

[0012] Preferably, the locking holes are arranged opposite to the locking grooves on the circumference of the lower cutter body and communicate with the locking grooves. The locking holes cooperate with the elastic locking pieces inside the locking grooves to realize the locking and positioning of the position of the lower cutter body. Therefore, the locking holes and the locking grooves are arranged opposite to each other.

[0013] Preferably, the inner diameter of the locking groove is larger than the inner diameter of the central hole, and a locking gap is provided between the elastic locking piece and the locking groove. In order to facilitate the installation of the elastic locking piece inside the locking groove, the inner diameter of the locking groove is larger than the inner diameter of the central hole. At the same time, in order to facilitate the elastic movement of the elastic locking piece, a locking gap is provided between the elastic locking piece and the locking groove. When the elastic locking piece locks with the cutter shaft, the elastic locking piece presses against the cutter shaft to prevent the axial sliding of the lower cutter body. When unlocking, the elastic locking piece elastically resets and disengages from the cutter shaft, so that the lower cutter body can be moved axially for adjustment.

[0014] Preferably, the elastic locking piece is an open elastic gasket; or the elastic locking piece is a segmented elastic gasket. The elastic locking piece can be an integrally formed spring gasket with an open structure, or various structures such as a segmented spring, as long as it can cooperate with the cutter shaft to realize locking and positioning.

[0015] The beneficial effects of the present utility model are as follows: The self-locking double-edge cutting lower knife of the present utility model adopts double cutting edges, and both ends can realize cutting during use, solving the problems of short service life and high cost of a single-edge cutting edge. At the same time, a self-locking positioning structure is provided on the lower cutter body. When it is necessary to adjust the cutting thickness, unlock the self-locking positioning structure, and then the lower cutter body can be moved axially for adjustment. The operation is convenient, fast, and efficient, and can meet the cutting requirements of different thicknesses, with a wide range of applications. Description of the Drawings

[0016] Figure 1 Fig. 1 is a schematic structural diagram of the self-locking double-edge cutting lower knife of the present utility model.

[0017] Fig. 2 is a schematic structural diagram of the self-locking double-edge cutting lower knife of the present utility model from another angle.

[0018] Fig. 3 is an exploded structural diagram of the self-locking double-edge cutting lower knife of the present utility model.

[0019] Fig. 4 is a sectional view of the self-locking double-edge cutting lower knife of the present utility model.

[0020] Figure 5 Fig. 5 is an axial sectional view of the self-locking double-edge cutting lower knife of the present utility model.

[0021] Figure 6 Fig. 6 is a schematic installation structural diagram of the self-locking double-edge cutting lower knife of the present utility model.

[0022] Figure 7 This is a diagram showing the working state of the self-locking double-edge cutting lower knife of the present utility model.

[0023] Figure 8 This is a schematic structural diagram of an adjustment state of the self-locking double-edge cutting lower knife of the present utility model.

[0024] Figure 9 This is a schematic structural diagram of the self-locking double-edge cutting lower knife in Embodiment 2.

[0025] Figure 10 This is a schematic structural diagram of the self-locking double-edge cutting lower knife in Embodiment 3.

[0026] In the figure: 1. Lower knife body, 2. Central hole, 3. Cutting edge, 4. Chip removal groove, 5. Locking hole, 6. Locking groove, 7. Elastic locking piece, 8. Locking part, 9. Knife shaft, 10. Installation width of the cutting lower knife, 11. Cutting upper knife. Specific embodiments

[0027] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the following further details the present utility model in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0028] Embodiment 1:

[0029] In Figure 1 、 Figure 2 、 Figure 3 In the shown embodiment, a self-locking double-edge cutting lower knife includes a lower knife body 1 with a central hole 2. On both end faces of the lower knife body 1, cutting edges 3 are respectively arranged to form a double-edge structure; a self-locking positioning structure for locking and positioning is arranged radially on the lower knife body 1. The lower knife body 1 is used to support the cutting edges 3 in the circumferential direction, the central hole 2 is used to install the lower knife body 1 on the knife shaft 9, and the cutting edges 3 are used to cut the material. The self-locking positioning structure is used to fix the relative position of the cutting edges 3 on the knife shaft 9 and prevent the axial sliding of the lower knife body 1.

[0030] The cutting edges 3 are arranged on the outer circumferences of both end faces of the lower knife body 1, and a cutting edge angle α is set between the cutting edges 3 and the lower knife body 1 in the radial direction. An annular chip removal groove 4 is arranged on the end face of the lower knife body 1 between the cutting edges 3 and the central hole 2; the cutting edge angle α is inclined from the outer circumference of the lower knife body 1 towards the bottom of the chip removal groove 4. The chip removal groove is used for chip accommodation and heat dissipation.

[0031] As Figure 4 、 Figure 5As shown, in this embodiment, the slitting edges 3 at both ends of the lower knife body 1 are symmetrically arranged, and the edge angles α of the slitting edges 2 at both ends are the same. The edge angles α are respectively 3 to 5°.

[0032] The self-locking positioning structure includes a locking groove 6 provided at the middle position of the central hole 2, an elastic locking piece 7 provided inside the locking groove 6, a locking hole 5 provided on the circumference of the lower knife body 1, and a locking member 8 provided inside the locking hole 5. The elastic locking piece 7 is provided for locking and positioning the lower knife body and for protecting the tool shaft to prevent damage to the tool shaft.

[0033] The locking hole 5 is provided on the circumference of the lower knife body 1 opposite to the locking groove 6 and communicates with the locking groove 6. The inner diameter of the locking groove 6 is larger than the inner diameter of the central hole 2, and a locking gap L is provided between the elastic locking piece 7 and the locking groove 6.

[0034] The elastic locking piece 7 is an open spring washer; or the elastic locking piece 7 is a segmented spring washer. In this embodiment, the elastic locking piece 7 is an integrally provided open spring washer.

[0035] Embodiment 2:

[0036] In Figure 9 In the shown embodiment, a self-locking double-edge slitting lower knife is installed on the tool shaft 9 of the lower knife, and by adjusting the distance between the slitting lower knives on the lower knife tool shaft 9, the adjustment requirements for different slitting thicknesses are met. When in use, the tool shaft and the lower knife body thereon can be used as a whole with reversed positions. That is, the left and right ends of the tool shaft are interchanged and used in cooperation with the slitting upper knife, and the slitting purpose can also be achieved.

[0037] The self-locking double-edge slitting lower knife includes a lower knife body 1 for supporting the circumferential edge. Slitting edges 3 are respectively provided on the axial end faces at both ends of the lower knife body 1. The slitting edges and the lower knife body are integrally processed and formed by grinding. An edge angle α is provided between the slitting edge 3 and the axial end face of the lower knife body 1. The edge angles α of the slitting edges at both ends are set to the same angle or different angles to meet the slitting needs of different materials, so as to achieve the purpose of multi-purpose use of one knife.

[0038] In this embodiment, the slitting edges 3 at both ends of the lower knife body 1 are asymmetrically arranged, and the edge angles α of the slitting edges 3 at both ends of the lower knife body 1 are different from each other. That is, the slitting edge at the left end in the figure is smaller than the slitting edge at the right end.

[0039] A central hole 2 for fitting and installing with the tool shaft 9 is axially provided on the lower knife body 1, and the inner diameter of the central hole 2 is matched with the outer diameter of the tool shaft 9.

[0040] A locking groove 6 is arranged inside the central hole 2 on the lower cutting body 1. The locking groove 6 is arranged at the central position of the axial direction of the central hole 2. The inner diameter of the locking groove 6 is larger than that of the central hole 2. An elastic locking piece 7 is arranged inside the locking groove 2. In this embodiment, the elastic locking piece 7 adopts a segmented spring gasket.

[0041] Two locking holes 5 are arranged on the circumference of the lower cutting body 1 at the center position of the groove width facing the locking groove 6. The locking holes 5 adopt locking threaded holes. A locking piece 8 is arranged inside the locking holes 5. When the locking piece 8 is in the locking state, the locking piece 8 presses against the outer circumference of the spring gasket 7 and makes the spring gasket 7 press tightly on the tool shaft 9 to achieve locking, so as to limit the cutting position of the lower cutting body 1 on the tool shaft 9 and prevent the lower cutting body 1 from sliding, thereby ensuring the cutting thickness and cutting quality. When the locking piece 8 is in the unlocking state, the end of the locking piece 8 does not contact the outer circumference of the spring gasket 7. The spring gasket 7 disengages from the pressing connection with the tool shaft 9 under the action of its own elasticity, and the lower cutting body 1 can be moved to adjust the cutting thickness between the lower cutting bodies 1.

[0042] A chip removal groove 4 is arranged on the end face of the lower cutting body 1 on the side of the cutting edge 3 close to the central hole 2 of the lower cutting body 1, which is used to accommodate the chips generated during the cutting process and to achieve heat dissipation during the cutting process. The chip removal groove 4 is an annular groove concentric with the central hole 5.

[0043] The cutting edge 3 on the lower cutting body 1 is formed by grinding. The cutting edge 3 can be ground and used multiple times, and can be ground up to the bottom position of the chip removal groove 4 at most. The cutting edge 3 is arranged in an asymmetric structure. The cutting edges 3 at both ends can be installed and used in the reverse direction to increase the grinding times of the cutting lower knife, thereby improving the service life of the cutting lower knife, reducing the number of tool changes, improving production efficiency, and reducing production costs.

[0044] The lower cutting body 1 is made of high-quality high-speed steel and has been quenched and tempered. The hardness can reach 61-63 HRC, and it also has excellent wear resistance and toughness, with a long service life. In this embodiment, the hardness of the lower cutting body is 61 HRC. When the edge angle α of the cutting edge 3 can be ground to 3-5°, while ensuring the sharpness of the edge 3, the tool has a longer service life. In order to reduce the friction between the cutting lower knife and the cutting material, the cutting edge 3 is ground with a high-mesh grinding wheel of GC#600, so that the surface finish of the cutting edge 3 is ≤5um.

[0045] In this embodiment, a spring washer is installed in the locking groove 6. The locking hole 5 is located at the middle position of the lower knife body 1, facing the locking groove 6 directly. A locking member 8 is screwed into the locking hole 5. The locking member 8 is a positioning screw, and the locking member 8 presses against the spring washer. Due to the easily deformable property of the spring washer, the positioning screw can press the slitting lower knife tightly against the tool shaft 9. Since the locking member 8 does not directly contact the tool shaft 9, the tool shaft 9 will not be damaged during the locking process.

[0046] As Figure 6 、 Figure 7 、 Figure 8 shown, during use, the self-locking double-edge slitting lower knife is installed on the tool shaft and cooperates with the slitting upper knife 11 to achieve slitting. The positions of the slitting lower knives relative to each other can be freely adjusted according to the required slitting thickness to change the slitting thickness between the slitting lower knives and the slitting upper knife 11, so as to meet the requirements of different material slitting thicknesses. For different slitting materials, the slitting edge angles on the lower knife body can be set to different angles. When the slitting edges at both ends of the lower knife body are symmetrically arranged, the edge angles of the slitting edges are the same. At this time, the two cutting edges of the material cut by the slitting material are symmetrical. When the slitting edges at both ends of the lower knife body are arranged in an asymmetric structure, the edge angles of the slitting edges can be set differently. For example, the angle at one end can be greater than that at the other end. At this time, the two cutting edges of the material cut by the slitting material are in an asymmetric structure. In short, the slitting edges can be designed according to needs to meet different slitting requirements.

[0047] Embodiment 3:

[0048] In Figure 10 the embodiment shown, a self-locking double-edge slitting lower knife includes a lower knife body 1. Slitting edges 3 are respectively arranged on the axial end faces at both ends of the lower knife body 1. An edge angle α is provided between the slitting edge 3 and the axial end face of the lower knife body 1. The edge angles α of the slitting edges at both ends of the lower knife body are set to different angles to meet the needs of slitting different materials, so as to achieve the purpose of multi-purpose cutting with one knife. The slitting edge 3 and the lower knife body 1 are arranged in a split manner. First, different slitting edges are ground into the required edge angles, and then they are formed into an integral structure with the lower knife body by welding.

[0049] In this embodiment, the slitting edges 3 at both ends of the lower knife body 1 are arranged asymmetrically, and the edge angles α of the slitting edges 3 at both ends of the lower knife body 1 are different from each other. That is, the slitting edge at the left end is smaller than the slitting edge at the right end. During use, the slitting edges can be arranged in the same direction on the tool shaft for use, or different slitting edges can be arranged opposite to each other to meet special slitting processing requirements.

[0050] A central hole 2 for mating with the tool shaft 9 is axially arranged on the lower knife body 1, and the inner diameter of the central hole 2 matches the outer diameter of the tool shaft 9.

[0051] A locking groove 6 is arranged inside a central hole 2 on the lower cutter body 1. The locking groove 6 is arranged at the central position of the axial direction of the central hole 2. The inner diameter of the locking groove 6 is larger than that of the central hole 2. The width of the locking groove 6 is less than one-third of the axial length of the lower cutter body and larger than one-fifth of the axial length of the lower cutter body. An elastic locking piece 7 is arranged inside the locking groove 2. In this embodiment, the elastic locking piece 7 is a spring gasket made of a highly wear-resistant elastic material. The spring gasket is arranged in a segmented manner with three segments, and a locking hole 5 is correspondingly arranged at each segment of the spring gasket.

[0052] Three locking holes 5 are arranged on the circumference of the lower cutter body 1 at the center position of the groove width of the locking groove 6. The three locking holes are evenly distributed on the circumference of the lower cutter body. The locking hole 5 is a locking threaded hole, and a locking piece 8 is arranged inside the locking hole 5. The locking piece 8 is a locking screw. When the locking piece 8 is in the locking state, the locking piece 8 presses against the outer circumference of the spring gasket 7 and makes the spring gasket 7 press tightly against the cutter shaft 9 to achieve locking, so as to limit the cutting position of the lower cutter body 1 on the cutter shaft 9 and prevent the lower cutter body 1 from sliding, thereby ensuring the cutting thickness and cutting quality. When the locking piece 8 is in the unlocking state, the end of the locking piece 8 does not contact the outer circumference of the spring gasket 7, and the spring gasket 7 disengages from the pressing connection with the cutter shaft 9 under the action of its own elasticity, and the lower cutter body 1 can be moved to adjust the cutting thickness between the lower cutter bodies 1.

[0053] A chip removal groove 4 is arranged on the end face of the lower cutter body 1 on the side of the cutting edge 3 close to the central hole 2 of the lower cutter body 1, which is used to accommodate the chips generated during the cutting process and to achieve heat dissipation during the cutting process. The chip removal groove 4 is an annular groove concentric with the central hole 5.

[0054] The cutting edge 3 on the lower cutter body 1 is formed by grinding. The cutting edge 3 can be ground and used multiple times, and can be ground up to the bottom position of the chip removal groove 4 at most. The cutting edge 3 is arranged in an asymmetric structure. The cutting edges 3 at both ends can be installed reversely to increase the grinding times of the cutting lower knife, thereby improving the service life of the cutting lower knife, reducing the number of tool changes, improving production efficiency, and reducing production costs.

[0055] The lower knife body 1 is made of high-quality high-speed steel and has been quenched and tempered, with a hardness of 63 HRC. It also has excellent wear resistance and toughness, and a long service life. When the edge angle α of the cutting edge 3 can be ground to 3 - 5°, while ensuring the sharpness of the cutting edge 3, the tool has a longer service life. To reduce the friction between the lower cutting knife and the cutting material, the cutting edge 3 is ground with a high-mesh grinding wheel of GC#600, so that the surface finish of the cutting edge 3 is ≤ 5um. In this embodiment, the edge angle α of the cutting edge at the left end is 3°, and the edge angle α of the cutting edge at the right end is 5°.

[0056] In this embodiment, a spring washer 7 is installed in the locking groove 6. The three locking holes 5 are located in the middle position of the lower knife body 1, facing the locking groove 6. A locking screw is screwed into the locking hole 5, and the end of the locking screw presses against the spring washer. By using the elastic deformation property of the spring washer, the locking screw can press the lower cutting knife tightly on the knife shaft 9. Because the locking screw does not directly contact the knife shaft 9, the knife shaft 9 will not be damaged during the locking process.

[0057] During use, the self-locking double-edge lower cutting knife is installed on the knife shaft and cooperates with the upper cutting knife 11 to achieve cutting. The positions of the lower cutting knives relative to each other can be freely adjusted according to the required cutting thickness to change the cutting thickness between the lower cutting knife and the upper cutting knife 11, so as to meet the requirements of different material cutting thicknesses.

[0058] The self-locking double-edge slitting lower knife in the above embodiments is provided with slitting edges 3 at both ends of the lower knife body 1, forming a double-edge structure, which can be installed for use in a reversible manner, or two materials with different slitting angles can be slit in one installation, making the slitting more convenient and more widely used. And a self-locking positioning structure is provided on the slitting lower knife, which is locked and positioned by a self-contained locking part and a spring gasket, without the need to separately match accessories such as a spacer or a gasket for clamping. The installation is more convenient and fast. The installation width 10 of the slitting lower knife can be adjusted without disassembling the slitting lower knife and the tool shaft 9 to adjust the slitting thickness. Or, without disassembling the slitting lower knife and the tool shaft, only the tool shaft and the slitting lower knife thereon need to be reversed as a whole, effectively reducing the number of disassembly and assembly times and improving the production efficiency. The freedom of the slitting width is improved. The slitting lower knife is provided with slitting edges at both ends. After wear occurs at one end of the distributing edge, there is no need to change the knife or grind the tool. Only the left and right positions of the slitting lower knife need to be adjusted, and the slitting can be carried out with the slitting edge on the other side, reducing the number of knife changes, increasing the tool life and the slitting processing efficiency, and reducing the tool input cost. One knife installation can complete the slitting amount of two knife installations. Compared with the slitting lower knife positioned by a spacer, it is more suitable for materials whose slitting width quantity needs to be frequently adjusted. As long as the slitting edges on the slitting lower knife are not worn, there is no need to reinstall the knife. Only the positioning screw needs to be loosened, the position of the slitting lower knife is readjusted, and the positioning screw is tightened again to complete the knife arrangement of the slitting lower knife, greatly improving the production efficiency.

[0059] The above embodiments are only a part of the embodiments of the present invention, rather than all embodiments. At the same time, based on the embodiments described in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts on the basis of the technical solutions of this application shall fall within the protection scope of the present invention.

Claims

1. A self-locking double-edged slitting lower knife, comprising a lower knife body (1) with a central hole (2), characterized in that: Cutting edges (3) are respectively arranged on both end surfaces of the lower knife body (1), and a self-locking positioning structure for locking and positioning is arranged in the radial direction of the lower knife body (1).

2. The self-locking double-edged slitting lower knife according to claim 1 is characterized in that: The slitting edge (3) is arranged on the outer circumference of the two end surfaces of the lower knife body (1), and a cutting edge angle α is formed between the slitting edge (3) and the lower knife body (1) in the radial direction.

3. The self-locking double-edged slitting lower knife according to claim 2 is characterized in that: An annular chip removal groove (4) is provided on the end surface of the lower knife body (1) between the cutting edge (3) and the center hole (2); the cutting edge angle α is inclined from the outer circumference of the lower knife body (1) to the bottom side of the chip removal groove (4).

4. The self-locking double-edged slitting lower knife according to claim 3 is characterized in that: The cutting edges (3) at both ends of the lower knife body (1) are symmetrically arranged, and the cutting edge angles α of the cutting edges (3) at both ends are the same, and the cutting edge angles α are respectively 3 to 5 degrees.

5. The self-locking double-edged slitting lower knife according to claim 3 is characterized in that: The cutting edges (3) at the two ends of the lower knife body (1) are arranged asymmetrically, and the cutting edge angles α of the cutting edges (3) at the two ends of the lower knife body (1) are different from each other.

6. The self-locking double-edged slitting lower knife according to any one of claims 1 to 5, characterized in that: The self-locking positioning structure comprises a locking groove (6) arranged in the middle of the central hole (2), an elastic locking piece (7) arranged inside the locking groove (6), a locking hole (5) arranged in the circumferential direction of the lower knife body (1), and a locking piece (8) arranged inside the locking hole (5).

7. The self-locking double-edged slitting lower knife according to claim 6, characterized in that: The locking hole (5) is arranged on the circumference of the lower knife body (1) opposite to the locking groove (6) and is communicated with the locking groove (6).

8. The self-locking double-edged slitting lower knife according to claim 6, characterized in that: The inner diameter of the locking groove (6) is greater than the inner diameter of the central hole (2), and a locking gap (L) is provided between the elastic locking piece (7) and the locking groove (6).

9. The self-locking double-edged slitting lower knife according to claim 6, characterized in that: The elastic locking piece (7) is an open spring washer; or the elastic locking piece (7) is a segmented spring washer.

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