Production and preparation process for aluminum-plastic film packaging bag

Abstract

The invention relates to the technical field of production of aluminum-plastic film packaging bags, in particular to a production and preparation process for aluminum-plastic film packaging bags, which comprises a conveying frame, a feeding frame is fixedly mounted on the conveying frame, suction hoods are fixedly connected to two sides of the feeding frame, and transmission mechanisms are rotatably connected to the exteriors of the suction hoods. The heat sealing machine is fixedly installed at one end of the conveying frame, the two cutting mechanisms are symmetrically arranged on one side of the cut-off tool, by arranging the cutting mechanisms, easy-to-tear openings can be automatically cut in the two sides of the aluminum-plastic film packaging bag through the two cutting tools, cutting of the easy-to-tear openings can be automatically completed in the production process of the aluminum-plastic film packaging bag, manual intervention is reduced, and the production efficiency is improved. And through the action of the electric push rod, the distance between the cutting knives can be adjusted according to the aluminum plastic film packaging bags with different widths, it is ensured that the device can adapt to the packaging bags with different sizes, and the universality and flexibility of the device are improved.

Description

Technical Field

[0001] This invention relates to the field of aluminum-plastic film packaging bag production technology, and in particular to a production process for aluminum-plastic film packaging bags. Background Technology

[0002] Aluminum-plastic film packaging bags are packaging materials made of aluminum foil and plastic film, widely used in the food, pharmaceutical, and cosmetic industries. Combining the advantages of aluminum foil and plastic, they offer excellent moisture resistance, oxidation resistance, UV protection, and barrier properties, ensuring product shelf life and quality. The production process of aluminum-plastic film packaging bags involves several key steps, including lamination, printing, bag making, heat sealing, and cutting, ensuring the final product has excellent protective performance, sealing properties, and good appearance quality.

[0003] The prior art publication CN111086272B provides a processing technology for aluminum-plastic packaging bags. After the guide plate is positioned on the connecting rod, the connecting frame can be rotated so that it is rotatably connected to the rotating shaft of the film roller. When the connecting frame is rotatably connected to the rotating shaft of the film roller, the two clamps on the same guide unit are in contact with the two sides of the film of the film roller, which is equivalent to limiting the film at the unwinding position. When the film roller deviates during rotation, the side of the film roller will squeeze the clamps, and the clamps are connected to elastic elements. The elastic elements force the clamps to push the film roller to move, so as to achieve the guiding and correction function of the film roller.

[0004] Existing technologies enable heat sealing and cutting of aluminum-plastic film packaging bags. However, to make the aluminum-plastic film packaging bags easier to open, easy-tear openings need to be provided on the side of the packaging bags. Existing technologies do not facilitate the automatic processing of easy-tear openings on aluminum-plastic film packaging bags, requiring additional processing steps and equipment, which increases production costs. Especially in mass production, the cost of this additional process may increase significantly.

[0005] In summary, the existing technology lacks a technique for processing aluminum-plastic film packaging bags with easy-tear openings. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the prior art by proposing a production process for aluminum-plastic film packaging bags.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a production process for aluminum-plastic film packaging bags, including a conveyor frame, a feeding rack fixedly installed on the conveyor frame, suction hoods fixedly connected to both sides of the feeding rack, a transmission mechanism rotatably connected to the outside of the suction hood, a heat sealing machine fixedly installed at one end of the conveyor frame, a support mechanism fixedly connected to one heat sealing plate of the heat sealing machine, a cutting blade provided on the other heat sealing plate of the heat sealing machine, and two cutting mechanisms symmetrically arranged on one side of the cutting blade.

[0008] Preferably, the conveyor frame is symmetrically connected with pulleys, and a conveyor belt is provided between the two pulleys for frictional transmission. One end of one pulley passes through the conveyor frame and is fixedly connected to a motor. The motor is fixedly connected to the conveyor frame. Both ends of the other pulley pass through the conveyor frame and are fixedly connected to a transmission wheel.

[0009] Preferably, the inner walls on both sides of the feeding rack are symmetrically connected with two conveying rollers. One end of each conveying roller extends through the inner wall of the feeding rack to the outside and is fixedly connected to a second motor. The second motor is fixedly connected to the outer wall of the feeding rack.

[0010] Preferably, a fan blade is rotatably connected to the inner wall of the suction hood, a driven wheel is fixedly connected to the end of the fan blade shaft, a placement seat is rotatably connected to the outlet of the suction hood, a filter tube is placed in the placement seat, the outer wall of the top end of the filter tube is slidably fitted with the inner wall of the outlet of the suction hood, a contact ring is fixedly connected to the outer wall of the filter tube, and a plug rod is threaded through one end of the placement seat, and the other end of the plug rod is movably inserted into the outlet of the suction hood.

[0011] Preferably, the transmission mechanism includes a universal joint, which is rotatably connected to the suction hood. A second transmission wheel is fixedly connected to one end of the universal joint, and the second transmission wheel meshes with the first transmission wheel for transmission. A worm is fixedly connected to the other end of the universal joint. The top end of the worm passes through the outer wall of the suction hood and extends into the interior, where a driving wheel is fixedly connected. The driving wheel meshes with the driven wheel for transmission.

[0012] Preferably, a worm gear is engaged with one side of the worm gear, and an L-shaped rod is fixedly connected to one end of the worm gear. The L-shaped rod is rotatably connected to the suction hood, and the other end of the L-shaped rod is in sliding contact with the contact ring.

[0013] Preferably, the support mechanism includes a cylinder, one end of which is fixedly connected to one of the heat sealing plates of the heat sealing machine, and a movable frame is fixedly connected to the output end of the cylinder. A support plate is slidably mounted on the movable frame, and multiple springs are fixedly connected between one side of the support plate and the movable frame.

[0014] Preferably, a movable frame two is fixedly connected to one side of the cutting blade, and a cylinder two is fixedly connected to the movable frame two. The cylinder two is fixedly connected to another heat sealing plate of the heat sealing machine.

[0015] Preferably, the cutting mechanism includes an electric actuator, one end of which is fixedly connected to the inner wall of the movable frame, and the output end of the electric actuator is fixedly connected to a locking seat. A cutting blade is provided on one side of the locking seat, and a locking block is slidably fitted on the inner wall of one end of the cutting blade. A tension spring is fixedly connected between the inner end of the locking block and the inner wall of the cutting blade, and an inclined surface is provided on the outer end of the locking block. The outer end of the locking block is movably inserted into the inner wall of the locking seat.

[0016] Compared with the prior art, the present invention has the following beneficial effects: By setting up a cutting mechanism, while the heat sealing machine drives two heat sealing plates to heat seal the aluminum-plastic film packaging bag, it also drives the cutting blade to move and cut the bag. At the same time, it can also drive the cutting mechanism to move. Using two cutting blades, easy-tear openings can be automatically cut on both sides of the aluminum-plastic film packaging bag. The easy-tear opening cutting can be automatically completed during the production process of aluminum-plastic film packaging bags, reducing manual intervention and improving production efficiency. Through the action of electric push rod, the spacing between the cutting blades can be adjusted according to the aluminum-plastic film packaging bags of different widths, ensuring that it can adapt to packaging bags of different sizes, increasing the versatility and flexibility of the equipment. At the same time, the cutting blades are snapped together with the snap-fit ​​base, making the maintenance and replacement of the cutting blades simpler and faster. By setting up a transmission mechanism and a suction hood, while the conveyor belt rotates to transport the aluminum-plastic film packaging bags, the transmission mechanism can drive the fan blades inside the suction hood to rotate, thereby sucking the scraps of aluminum-plastic film packaging bags cut off by the cutting knife into the suction hood and collecting them through the filter tube. This effectively reduces the amount of waste generated during the production process, keeps the production environment clean, and not only helps to reduce the workload of cleaning and maintenance, but also improves the overall hygiene standards of the production line. By incorporating an L-shaped rod, the transmission mechanism drives the fan blades to rotate, simultaneously rotating the L-shaped rod and lifting the filter tube. The filter tube then automatically falls under its own weight, generating vibration. This vibration ensures the filter tube's filtration efficiency, allowing it to operate efficiently for extended periods. Furthermore, a spring-loaded support plate provides support on the other side of the aluminum-plastic film packaging bag during cutting by the cutting blades. This support plate provides counter-support to the bag during cutting, effectively preventing twisting or wrinkling caused by the cutting blade's pressure. The spring's elasticity acts as a buffer, reducing mechanical impact during cutting, minimizing wear and tear, and extending the equipment's lifespan. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a manufacturing process for aluminum-plastic film packaging bags according to the present invention; Figure 2 This is a partial structural schematic diagram of a manufacturing process for aluminum-plastic film packaging bags according to the present invention; Figure 3 This is a partial cross-sectional schematic diagram of a conveyor frame structure for the production and preparation process of aluminum-plastic film packaging bags according to the present invention; Figure 4 This is a partial cross-sectional schematic diagram of a feeding rack structure for the production and preparation process of aluminum-plastic film packaging bags according to the present invention; Figure 5 This is a partial cross-sectional schematic diagram of the suction hood and other structures used in the production process of aluminum-plastic film packaging bags according to the present invention. Figure 6 This is a schematic diagram of a transmission mechanism structure for the production and preparation process of aluminum-plastic film packaging bags according to the present invention; Figure 7 This is a schematic diagram of the support mechanism and cutting blade structure used in the production process of aluminum-plastic film packaging bags according to the present invention. Figure 8 This is a partially unfolded schematic diagram of the cutting mechanism structure for the production and preparation process of aluminum-plastic film packaging bags according to the present invention.

[0018] The following are labeled in the diagram: 1. Conveyor frame; 2. Feeding frame; 3. Suction hood; 4. Transmission mechanism; 5. Heat sealing machine; 6. Support mechanism; 7. Cutting knife; 8. Cutting mechanism; 101. Pulley; 102. Conveyor belt; 103. Motor 1; 104. Transmission wheel 1; 201. Conveyor roller; 202. Motor 2; 301. Fan blade; 302. Driven wheel; 303. Placement seat; 304. Filter tube; 305. Contact ring 306. Insert rod; 401. Universal joint; 402. Drive wheel two; 403. Worm gear; 404. Drive wheel; 405. Worm wheel; 406. L-shaped rod; 601. Cylinder one; 602. Moving frame one; 603. Support plate; 604. Spring; 701. Moving frame two; 702. Cylinder two; 801. Electric actuator; 802. Snap-fit ​​seat; 803. Cutting knife; 804. Snap-fit ​​block; 805. Tension spring. Detailed Implementation

[0019] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0020] like Figures 1-8The process for producing aluminum-plastic film packaging bags shown includes a conveyor frame 1, a feeding rack 2 fixedly mounted on the conveyor frame 1, suction hoods 3 fixedly connected to both sides of the feeding rack 2, a transmission mechanism 4 rotatably connected to the outside of the suction hoods 3, a heat sealing machine 5 fixedly mounted at one end of the conveyor frame 1, a support mechanism 6 fixedly connected to one heat sealing plate of the heat sealing machine 5, a cutting blade 7 on the other heat sealing plate of the heat sealing machine 5, and two cutting mechanisms 8 symmetrically arranged on one side of the cutting blade 7.

[0021] like Figure 3 As shown, the conveyor frame 1 is symmetrically connected with pulleys 101, and a conveyor belt 102 is provided between the two pulleys 101 for frictional transmission. One end of one pulley 101 passes through the conveyor frame 1 and is fixedly connected to a motor 103. The motor 103 is fixedly connected to the conveyor frame 1. Both ends of the other pulley 101 pass through the conveyor frame 1 and are fixedly connected to a transmission wheel 104.

[0022] like Figure 4 As shown, the inner walls of the feeding rack 2 are symmetrically connected with two conveying rollers 201. One end of the conveying roller 201 extends through the inner wall of the feeding rack 2 to the outside and is fixedly connected to a motor 202. The motor 202 is fixedly connected to the outer wall of the feeding rack 2.

[0023] like Figure 5 As shown, a fan blade 301 is rotatably connected to the inner wall of the suction hood 3. A driven wheel 302 is fixedly connected to the shaft end of the fan blade 301. A placement seat 303 is rotatably connected to the outlet of the suction hood 3. A filter tube 304 is placed inside the placement seat 303. The outer wall of the top end of the filter tube 304 is slidably fitted with the inner wall of the outlet of the suction hood 3. A contact ring 305 is fixedly connected to the outer wall of the filter tube 304. An insertion rod 306 is threaded through one end of the placement seat 303. The other end of the insertion rod 306 is movably inserted into the outlet of the suction hood 3. The rotation of the fan blade 301 generates negative pressure, which sucks the scrap material generated by the cutting into the suction hood 3 and traps it in the filter tube 304, preventing the scrap material from scattering and contaminating the production environment. The filter tube 304 can be quickly disassembled for cleaning, making maintenance convenient.

[0024] like Figure 6 As shown, the transmission mechanism 4 includes a universal joint 401, which is rotatably connected to the suction cover 3. One end of the universal joint 401 is fixedly connected to a second transmission wheel 402, which meshes with the first transmission wheel 104 for transmission. The other end of the universal joint 401 is fixedly connected to a worm gear 403, the top of which passes through the outer wall of the suction cover 3 and extends into the interior, where a driving wheel 404 is fixedly connected. The driving wheel 404 meshes with the driven wheel 302 for transmission.

[0025] A worm gear 403 is equipped with a worm wheel 405 on one side for meshing transmission. An L-shaped rod 406 is fixedly connected to one end of the worm wheel 405. The L-shaped rod 406 is rotatably connected to the suction hood 3, and the other end of the L-shaped rod 406 is in sliding contact with the contact ring 305. The transmission mechanism 4 diverts the power from the transmission wheel 104 to the worm gear 403 through a universal joint 401. On the one hand, this drives the fan blade 301 to rotate and generate negative pressure. On the other hand, it drives the worm wheel 405 and the L-shaped rod 406 to swing, realizing the vibration feeding of the filter tube 304, avoiding the blockage of the filter tube by scrap material, and improving the waste collection efficiency.

[0026] like Figure 7 As shown, the support mechanism 6 includes a cylinder 601. One end of the cylinder 601 is fixedly connected to one of the heat-sealing plates of the heat-sealing machine 5. A movable frame 602 is fixedly connected to the output end of the cylinder 601. A support plate 603 is slidably mounted on the movable frame 602. Multiple springs 604 are fixedly connected between one side of the support plate 603 and the movable frame 602. The elastic force of the springs 604 makes the support plate 603 fit tightly against the surface of the packaging bag, providing stable support for the cutting blade 7 and the slicing blade 803, preventing the packaging bag from shifting or deforming during cutting, and ensuring a smooth and thorough cut.

[0027] like Figure 7 As shown, a movable frame 701 is fixedly connected to one side of the cutting blade 7, and a cylinder 702 is fixedly connected to the movable frame 701. The cylinder 702 is fixedly connected to another heat sealing plate of the heat sealing machine 5.

[0028] like Figure 8 As shown, the cutting mechanism 8 includes an electric actuator 801. One end of the electric actuator 801 is fixedly connected to the inner wall of the movable frame 701. A locking seat 802 is fixedly connected to the output end of the electric actuator 801. A cutting blade 803 is provided on one side of the locking seat 802. A locking block 804 is slidably fitted on the inner wall of one end of the cutting blade 803. A tension spring 805 is fixedly connected between the inner end of the locking block 804 and the inner wall of the cutting blade 803. An inclined surface is opened on the outer end of the locking block 804. The outer end of the locking block 804 is movably inserted into the inner wall of the locking seat 802. The distance between the two cutting blades 803 can be precisely adjusted by the electric actuator 801 to adapt to the easy-tear processing needs of packaging bags of different widths; the snap-fit ​​design of the cutting blade 803 and the snap-fit ​​base 802 allows for quick disassembly and replacement without tools, adapting to the processing needs of easy-tear openings of different shapes, and making maintenance convenient; during the cutting operation, the cutting blade 803 simultaneously cuts easy-tear openings on both sides of the packaging bag, eliminating the need for subsequent processing steps and improving production efficiency.

[0029] By setting up a cutting mechanism 8, while the heat sealing machine 5 drives two heat sealing plates to heat seal the aluminum-plastic film packaging bag, it also drives the cutting blade 7 to move and cut. At the same time, it can also drive the cutting mechanism 8 to move. Using two cutting blades 803, easy-tear openings can be automatically cut on both sides of the aluminum-plastic film packaging bag. The easy-tear opening can be automatically cut during the production process of aluminum-plastic film packaging bags, reducing manual intervention and improving production efficiency. Through the action of the electric push rod 801, the spacing between the cutting blades 803 can be adjusted according to the aluminum-plastic film packaging bags of different widths, ensuring that it can adapt to packaging bags of different sizes, increasing the versatility and flexibility of the equipment. At the same time, the cutting blades 803 are engaged with the snap-fit ​​seat 802, making the maintenance and replacement of the cutting blades 803 simpler and faster.

[0030] Working principle: During the processing of aluminum-plastic film packaging bags, the aluminum-plastic film packaging bags, which are sealed on both sides vertically, are first inserted from above the heat sealing machine 5 through the conveying equipment and inserted between the conveying rollers 201 on both sides below. Then, the conveying rollers 201 are rotated by the motor 202, which can drive the aluminum-plastic film packaging bags to move down. Then, according to the horizontal sealing position of the aluminum-plastic film packaging bag, the positions of the moving frame 602 and the moving frame 701 are adjusted by cylinder 601 and cylinder 702 respectively. Then, one end of the required cutting knife 803 is inserted into the snap-fit ​​seat 802. Then, under the action of the tension spring 805, the snap-fit ​​block 804 is driven to snap-fit ​​with the snap-fit ​​seat 802. Then, the distance between the two cutting knives 803 is adjusted by electric push rod 801. Then, the heat sealing machine 5 can drive the two heat sealing plates to come closer to each other to seal the aluminum-plastic film packaging bag horizontally. When the heat sealing machine 5 performs the next sealing, it will drive the support plate 603 on the moving frame 1 602 to move, and drive the cutting knife 7 and the slit knife 803 on the moving frame 2 701 to come closer and support the aluminum-plastic film packaging bag under the action of the support plate 603 connected by the spring 604, so that the cutting knife 7 and the slit knife 803 can perform stable cutting and slit. Meanwhile, when the motor 103 drives the conveyor belt 102 connected to the pulley 101 to rotate and transport the sealed and cut aluminum-plastic film packaging bags, the transmission wheel 104 connected to another pulley 101 will drive the transmission wheel 402 to rotate, so that the transmission wheel 402 can drive the worm 403 connected to the universal joint 401 to rotate. At this time, the worm 403 will drive the fan blade 301 connected to the driven wheel 302 to rotate through the connected driving wheel 404, so that the fan blade 301 can suck the scraps cut by the cutting knife 803 into the suction hood 3 and filter them through the filter tube 304. Simultaneously, when the worm gear 403 rotates, it drives the meshing worm wheel 405 to rotate, which in turn drives the connected L-shaped rod 406 to rotate. This allows the L-shaped rod 406 to contact and push the filter tube 304 connected to the contact ring 305 upward. Then, when the L-shaped rod 406 disengages from the contact ring 305, the filter tube 304 automatically falls under its own weight, generating vibration. This causes the scrap material to concentrate at the bottom of the filter tube 304. When it is necessary to disassemble the filter tube 304, the top of the insert rod 306 is removed from the suction cover 3 by rotating the insert rod 306. At this time, the placement seat 303 is pushed, causing the placement seat 303 to rotate the filter tube 304 to one side, so that the filter tube 304 can be removed for cleaning.

[0031] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A manufacturing process for aluminum-plastic film packaging bags, comprising a conveyor frame (1), characterized in that: A feeding rack (2) is fixedly installed on the conveyor frame (1). Suction hoods (3) are fixedly connected to both sides of the feeding rack (2). A transmission mechanism (4) is rotatably connected to the outside of the suction hoods (3). A heat sealing machine (5) is fixedly installed at one end of the conveyor frame (1). A support mechanism (6) is fixedly connected to one of the heat sealing plates of the heat sealing machine (5). A cutting knife (7) is provided on the other heat sealing plate of the heat sealing machine (5). Two cutting mechanisms (8) are symmetrically arranged on one side of the cutting knife (7).

2. The manufacturing process for aluminum-plastic film packaging bags according to claim 1, characterized in that: The conveyor frame (1) is symmetrically connected with pulleys (101), and a conveyor belt (102) is provided between the two pulleys (101) for friction transmission. One end of one of the pulleys (101) passes through the conveyor frame (1) and is fixedly connected to a motor (103). The motor (103) is fixedly connected to the conveyor frame (1). Both ends of the other pulley (101) pass through the conveyor frame (1) and are fixedly connected to a transmission wheel (104).

3. The manufacturing process for aluminum-plastic film packaging bags according to claim 1, characterized in that: The inner walls of the feeding rack (2) are symmetrically connected with two conveying rollers (201). One end of the conveying roller (201) extends through the inner wall of the feeding rack (2) to the outside and is fixedly connected to a motor (202). The motor (202) is fixedly connected to the outer wall of the feeding rack (2).

4. The manufacturing process for aluminum-plastic film packaging bags according to claim 2, characterized in that: The inner wall of the suction hood (3) is rotatably connected to a fan blade (301), and a driven wheel (302) is fixedly connected to the shaft end of the fan blade (301). The outlet of the suction hood (3) is rotatably connected to a placement seat (303). A filter tube (304) is placed inside the placement seat (303). The outer wall of the top end of the filter tube (304) is slidably fitted with the inner wall of the outlet of the suction hood (3). A contact ring (305) is fixedly connected to the outer wall of the filter tube (304). A rod (306) is threadedly connected to one end of the placement seat (303), and the other end of the rod (306) is movably inserted into the outlet of the suction hood (3).

5. The manufacturing process for aluminum-plastic film packaging bags according to claim 4, characterized in that: The transmission mechanism (4) includes a universal joint (401), which is rotatably connected to the suction shroud (3). One end of the universal joint (401) is fixedly connected to a second transmission wheel (402), which meshes with a first transmission wheel (104). The other end of the universal joint (401) is fixedly connected to a worm gear (403), the top of which extends through the outer wall of the suction shroud (3) and is fixedly connected to a drive wheel (404), which meshes with a driven wheel (302).

6. The manufacturing process for aluminum-plastic film packaging bags according to claim 5, characterized in that: The worm gear (403) is equipped with a worm wheel (405) on one side for meshing transmission. An L-shaped rod (406) is fixedly connected to one end of the worm wheel (405). The L-shaped rod (406) is rotatably connected to the suction hood (3). The other end of the L-shaped rod (406) is in sliding contact with the contact ring (305).

7. The manufacturing process for aluminum-plastic film packaging bags according to claim 1, characterized in that: The support mechanism (6) includes a cylinder (601), one end of which is fixedly connected to one of the heat sealing plates of the heat sealing machine (5). A movable frame (602) is fixedly connected to the output end of the cylinder (601). A support plate (603) is slidably mounted on the movable frame (602). A plurality of springs (604) are fixedly connected between one side of the support plate (603) and the movable frame (602).

8. The manufacturing process for aluminum-plastic film packaging bags according to claim 1, characterized in that: A movable frame two (701) is fixedly connected to one side of the cutting knife (7), and a cylinder two (702) is fixedly connected to the movable frame two (701). The cylinder two (702) is fixedly connected to another heat sealing plate of the heat sealing machine (5).

9. The manufacturing process for aluminum-plastic film packaging bags according to claim 8, characterized in that: The cutting mechanism (8) includes an electric push rod (801), one end of which is fixedly connected to the inner wall of the second movable frame (701). A locking seat (802) is fixedly connected to the output end of the electric push rod (801). A cutting knife (803) is provided on one side of the locking seat (802). A locking block (804) is slidably fitted on the inner wall of one end of the cutting knife (803). A tension spring (805) is fixedly connected between the inner end of the locking block (804) and the inner wall of the cutting knife (803). An inclined surface is opened on the outer end of the locking block (804). The outer end of the locking block (804) is movably inserted into the inner wall of the locking seat (802).

Images