A bottle blowing machine and a sterilization method for a bottle blowing machine

Abstract

The present application relates to a kind of bottle blowing machine and the sterilization method of bottle blowing machine, bottle blowing machine includes bottle blowing unit, screw driving mechanism, protective cover and gas source.Bottle blowing unit includes cylinder, piston shaft and stretch rod, cylinder is provided with air inlet hole, piston shaft is arranged in cylinder, and gap between piston shaft and cylinder.There is blow channel between stretch rod and piston shaft, and blow channel and air inlet hole are all communicated with gap.Screw driving mechanism is connected with the stretch rod, and screw driving mechanism is used to drive stretch rod lifting movement.Protective cover is covered in the periphery of screw driving mechanism, and the top end of stretch rod and piston shaft is located in protective cover.Gas source is connected with air inlet hole and protective cover, and high-pressure air is input to air inlet hole in bottle blowing state;In sterilization state, sterilization gas is input to air inlet hole and protective cover in the gas source.The bottle blowing machine can reduce sterilization dead angle, improve sterilization quality.

Description

Technical Field

[0001] This invention relates to the field of blow molding machine technology, and more particularly to a blow molding machine and a sterilization method for the blow molding machine. Background Technology

[0002] A blow molding machine is a device used to blow-molde preforms into bottle preforms. It mainly consists of a frame, a blow molding unit mounted on the frame, and other supporting components. The blow molding unit is equipped with a lifting and lowering tension rod for inserting into the preform, and a blowing channel for high-pressure gas flow is formed around the tension rod. During the blow molding process, high-pressure gas is blown into the preform through the blowing channel, and the insertion of the tension rod promotes bottle shaping. In related technologies, after the bottles are blow-molded, they are transferred to a sterilization station for appropriate sterilization treatment. To adapt to some special process adjustments or meet certain processing standards, the blow molding unit needs to be sterilized to meet the aseptic requirements of the preform during the blow molding process. However, existing sterilization methods mainly use ultraviolet (UV) sterilization. In this sterilization method, UV light has difficulty penetrating the inside of the blowing channel, easily creating sterilization dead zones and affecting the sterilization effect. Summary of the Invention

[0003] The purpose of this invention is to provide a blow molding machine and a sterilization method for the blow molding machine, which can reduce sterilization dead spots and improve sterilization quality.

[0004] To achieve this objective, the present invention adopts the following technical solution: Firstly, a blow molding machine is provided, comprising: A blow molding unit includes a cylinder, a piston shaft, and a tension rod. The cylinder has an air inlet. The piston shaft passes through the cylinder and there is a gap between the piston shaft and the cylinder. The tension rod passes through the piston shaft and there is a blow molding channel between the piston shaft and the tension rod. The blow molding channel and the air inlet are both connected to the gap. A lead screw drive mechanism is connected to the tension rod, and the lead screw drive mechanism is used to drive the tension rod to move up and down; A protective cover is provided around the screw drive mechanism, and the top ends of the tension rod and the piston shaft are located inside the protective cover; The gas source is connected to the air inlet and the protective cover. In the blow molding state, the gas source inputs high-pressure air into the air inlet; in the sterilization state, the gas source inputs sterilizing gas into the air inlet and the protective cover.

[0005] As a preferred embodiment of the blow molding machine, the gaps include a first gap, a second gap, and a third gap arranged sequentially along the axial direction of the piston shaft. The air inlet and the blowing channel are both connected to the second gap. A first sealing ring, a second sealing ring, a third sealing ring, and a fourth sealing ring are fitted around the periphery of the piston shaft. The first gap is located between the first sealing ring and the second sealing ring, the second gap is located between the second sealing ring and the third sealing ring, and the third gap is located between the third sealing ring and the fourth sealing ring. In the blow molding state, the first gap and the third gap are both sealed and isolated from the second gap. In the sterilization state, the first gap and the third gap are both connected to the second gap.

[0006] As a preferred embodiment of the blow molding machine, the cylinder body is provided with a sterilization channel and a mounting hole for the piston shaft to pass through. The mounting hole wall is provided with a first annular groove and a second annular groove. The first annular groove communicates with the sterilization channel, and the second annular groove communicates with the air inlet. In the blow molding state, the second sealing ring and the third sealing ring abut against the wall of the mounting hole so that the second gap communicates only with the blow molding channel. In the sterilization state, the second sealing ring and the third sealing ring move to the slot positions of the first annular groove and the second annular groove, respectively, so that the first gap, the second gap and the third gap all communicate with the sterilization channel.

[0007] As a preferred embodiment of the blow molding machine, the sterilization channel includes two inlet ends and one outlet end. One inlet end of the sterilization channel is connected to the first annular groove, the other inlet end is connected to the third gap, and the outlet end of the sterilization channel is connected to the outside of the cylinder.

[0008] As a preferred embodiment of the blow molding machine, it further includes a cam drive mechanism and a lifting cylinder. The cam drive mechanism is connected to the piston shaft and is used to drive the piston shaft to move up and down in a first stroke. The lifting cylinder is selectively connected to the piston shaft and is used to drive the piston shaft to move up and down in a second stroke, the second stroke being longer than the first stroke.

[0009] As a preferred embodiment of a blow molding machine, the cam drive mechanism includes a second guide rail, a slide block, a follower wheel, and an annular cam. The second guide rail is vertically mounted on the support, the slide block is slidably connected to the second guide rail, and the slide block is elastically connected to the support. The follower wheel is rotatably mounted on the slide block, the top surface of the annular cam abuts against the follower wheel, the top of the piston shaft is connected to the slide block, and the top of the piston shaft is located inside the protective cover.

[0010] As a preferred embodiment of a blow molding machine, during blow molding, the gas source inputs sterile gas into the protective cover to create a positive pressure environment inside the protective cover.

[0011] As a preferred embodiment of the blow molding machine, it also includes a sealing assembly for selectively communicating with the blowing channel and for receiving sterilizing gas discharged from the blowing channel.

[0012] As a preferred embodiment of the blow molding machine, it also includes a support frame. The lead screw drive mechanism includes a first guide rail, a lead screw, a slider assembly, a motor, and a baffle. The first guide rail is vertically mounted on the support frame. The slider assembly is slidably connected to the first guide rail. The lead screw passes through the slider assembly and is threadedly connected to the slider assembly. The motor is connected to the lead screw to drive the lead screw to rotate. The top end of the tension rod is connected to the slider assembly. The baffle is movably mounted on the slider assembly and is located on the side of the lead screw facing the protective cover.

[0013] Secondly, a sterilization method for a blow molding machine is also provided, applicable to the blow molding machine, comprising: in the blow molding state, a gas source inputs high-pressure air into the air inlet, the high-pressure air is blown towards the preform through the blowing channel, and at the same time, the gas source inputs sterile gas into the protective cover, and makes the internal space of the protective cover positive pressure; in the sterilization state, the gas source inputs sterilizing gas into the air inlet and the protective cover, so that the sterilizing gas sterilizes the area through which the high-pressure air flows, and the sterilizing gas sterilizes the internal space of the protective cover.

[0014] The advantages of this invention compared to the prior art are: The blow molding machine and sterilization method of the present invention sterilize the area through which the high-pressure gas passes within the blow molding unit by introducing sterilizing gas into the air inlet, thus preventing bacteria generated within the blow molding unit from entering the bottle with the high-pressure air. The sterilizing gas can penetrate deep into the channels inside the blow molding unit, reducing sterilization dead zones and improving sterilization quality. Furthermore, by providing a protective cover to protect the piston shaft and extension rod extending outside the cylinder, and by introducing sterilizing gas into the protective cover during sterilization, more comprehensive sterilization of the piston shaft and extension rod is achieved, improving the overall sterilization quality of the blow molding unit. Attached Figure Description

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0016] Figure 1 This is a schematic diagram of a blow molding machine according to an embodiment of the present invention from a first-view perspective.

[0017] Figure 2This is a schematic diagram of a blow molding machine from a second perspective according to an embodiment of the present invention.

[0018] Figure 3 This is a partial cross-sectional view (blowing state) of the blow molding unit according to an embodiment of the present invention.

[0019] Figure 4 This is a partial cross-sectional view (sterilized state) of the blow molding unit according to an embodiment of the present invention.

[0020] Figure 5 This is a schematic diagram of the slider assembly according to an embodiment of the present invention.

[0021] Figure 6 This is a schematic diagram of the sealing assembly according to an embodiment of the present invention.

[0022] In the picture: 1. Blow-blowing unit; 10. Cylinder body; 101. Air inlet; 102. Sterilization channel; 1021. Channel outlet; 103. First annular groove; 104. Second annular groove; 11. Piston shaft; 111. Connecting hole; 12. Tension rod; 13. Gap; 131. First gap; 132. Second gap; 133. Third gap; 14. Blow-blowing channel; 15. First sealing ring; 16. Second sealing ring; 17. Third sealing ring; 18. Fourth sealing ring; 19. Blow-blowing nozzle; 191. Blow-blowing hole; 2. Screw drive mechanism; 21. First guide rail 22. Lead screw; 23. Slider assembly; 231. Connector; 232. Connecting nut; 233. Clearance hole; 24. Motor; 25. Baffle; 3. Cam drive mechanism; 31. Annular cam; 32. Second guide rail; 33. Slide seat; 34. Follower wheel; 35. Spring; 4. Lifting cylinder; 5. Protective cover; 51. Cover body; 52. Sterilization inlet connector; 53. Sterilization outlet connector; 54. Sterile gas connector; 6. Support; 7. Sealing assembly; 71. Drive component; 72. Cup lid; 73. Pipe connector; 74. Cover plate; 8. Blow molding die. Detailed Implementation

[0023] The advantages and features of the present invention, as well as methods of implementing them, will become apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms. These embodiments are provided merely to complete the disclosure of the invention and to enable those skilled in the art to fully understand the scope of the invention, which is defined only by the scope of the claims. The same reference numerals denote the same constituent elements throughout the specification.

[0024] The present invention will now be described in detail with reference to the accompanying drawings.

[0025] like Figures 1 to 4As shown, this invention provides a blow molding machine for blow molding preforms to form bottles for filling beverages. The blow molding machine includes a blow molding unit 1, a screw drive mechanism 2, a protective cover 5, and an air source. The blow molding unit 1 is the direct actuator for blow molding, connecting to the preform and blowing high-pressure air into it. The blow molding unit 1 includes a cylinder 10, a piston shaft 11, and a tension rod 12. The cylinder 10 is the main structure of the blow molding unit 1, and an air inlet 101 is provided on the cylinder 10. The piston shaft 11 extends vertically and passes through the cylinder 10, with a gap 13 between the piston shaft 11 and the cylinder 10. The tension rod 12 extends vertically and passes through the piston shaft 11, with an air blowing channel 14 between the piston shaft 11 and the tension rod 12. The air blowing channel 14 communicates with the gap 13, and the air inlet 101 communicates with the gap 13. The air inlet 101, gap 13, and blowing channel 14 are connected to allow gas flow. The lead screw drive mechanism 2 is connected to the tension rod 12 and drives the tension rod 12 to move up and down. During bottle blowing, the tension rod 12 descends so that its bottom end inserts into the preform, promoting preform formation. A protective cover 5 surrounds the lead screw drive mechanism 2, providing dust and bacteria protection. The top end of the tension rod 12 extends to the outside of the cylinder 10 and connects to the lead screw drive mechanism 2; the top end of the tension rod 12 is located inside the protective cover 5. Similarly, the top end of the piston shaft 11 extends to the outside of the cylinder 10 and is located inside the protective cover 5. An air source is connected to the air inlet 101 and the protective cover 5. The air source stores high-pressure air and sterilizing gas, and supplies high-pressure air and sterilizing gas into the air inlet 101 or the protective cover 5. The sterilizing gas is hydrogen peroxide vapor. During the blow molding process, high-pressure air is introduced into the inlet 101 by the gas source. The high-pressure air flows through the gap 13 and the blowing channel 14 to the preform, thus blowing the preform. During the sterilization process, sterilizing gas is introduced into the inlet 101 and the protective cover 5 by the gas source. On one hand, the sterilizing gas flows through the inlet 101, the gap 13, and the blowing channel 14 to sterilize the area through which the high-pressure gas passes within the cylinder 10. On the other hand, the sterilizing gas enters the interior of the protective cover 5 to sterilize the internal area of ​​the protective cover 5; that is, the piston shaft 11 and the tension rod 12 located inside the protective cover 5 are sterilized accordingly.

[0026] It is understandable that by introducing sterilizing gas into the air inlet 101, the area through which the high-pressure gas passes within the blow molding unit 1 is sterilized, thus preventing bacteria generated within the blow molding unit 1 from entering the bottle with the high-pressure air. The sterilizing gas can penetrate deep into the channels inside the blow molding unit 1, reducing sterilization dead zones and improving sterilization quality. Furthermore, by providing a protective cover 5, the piston shaft 11 and the extension rod 12 extending to the outside of the cylinder 10 are protected against bacteria. During sterilization, sterilizing gas is introduced into the protective cover 5 to achieve more comprehensive sterilization of the piston shaft 11 and the extension rod 12, thereby improving the overall sterilization quality of the blow molding unit 1.

[0027] Specifically, refer to Figure 3 and Figure 4As shown, the cylinder body 10 is provided with a sterilization channel 102 and a mounting hole. The sterilization channel 102 is used for the discharge of sterilization gas, and the mounting hole is used for the piston shaft 11 to pass through. A gap 13 is formed between the piston shaft 11 and the wall of the mounting hole. The gap 13 includes a first gap 131, a second gap 132, and a third gap 133 arranged sequentially along the axial direction of the piston shaft 11. The position of the air inlet 101 corresponds to the second gap 132, so that the air inlet 101 communicates directly with the second gap 132. A connecting hole 111 is provided on the piston shaft 11, and the air blowing channel 14 is connected to the second gap 132 through the connecting hole 111, so that high-pressure gas can flow through the air inlet 101, the second gap 132, the connecting hole 111, and the air blowing channel 14 in sequence. A first sealing ring 15, a second sealing ring 16, a third sealing ring 17, and a fourth sealing ring 18 are fitted around the periphery of the piston shaft 11. The first sealing ring 15, the second sealing ring 16, the third sealing ring 17, and the fourth sealing ring 18 are distributed from top to bottom along the axial direction of the piston shaft 11. The four sealing rings are used to seal the gap 13. Correspondingly, the first gap 131 is located between the first sealing ring 15 and the second sealing ring 16, the second gap 132 is located between the second sealing ring 16 and the third sealing ring 17, and the third gap 133 is located between the third sealing ring 17 and the fourth sealing ring 18. In the blowing state, all sealing rings are pressed against the cylinder body 10 and the piston shaft 11 to seal and isolate the first gap 131 from the second gap 132, and the third gap 133 from the second gap 132. In this state, high-pressure gas can only enter the second gap 132 through the air inlet 101, and then enter the blowing channel 14 through the connecting hole 111. During sterilization, the first sealing ring 15 and the fourth sealing ring 18 are sealed, while the second sealing ring 16 and the third sealing ring 17 are unsealed. The first gap 131, the third gap 133, and the sterilization channel 102 are all connected to the second gap 132. In this state, sterilizing gas enters the entire gap 13 through the air inlet 101, and then part of the sterilizing gas enters the blowing channel 14 through the connecting hole 111, while the other part of the sterilizing gas is discharged through the sterilization channel 102. In this embodiment, since the piston shaft 11 needs to move up and down during the bottle blowing process, the corresponding second sealing ring 16 and the third sealing ring 17 will also move accordingly. Bacteria can easily hide in the contact area of ​​the sealing rings. By setting the sterilization channel 102 and connecting the entire gap 13 during sterilization, the contact surfaces of the second sealing ring 16 and the third sealing ring 17 can be exposed to the sterilizing gas to sterilize the contact surfaces of the second sealing ring 16 and the third sealing ring 17, further eliminating sterilization dead zones in the bottle blowing unit 1.

[0028] To enable the second sealing ring 16 and the third sealing ring 17 to switch between sealed and unsealed states, a first annular groove 103 and a second annular groove 104 are provided on the wall of the mounting hole. The first annular groove 103 and the second annular groove 104 are spaced apart along the axial direction of the mounting hole, and both the first annular groove 103 and the second annular groove 104 are arranged circumferentially along the mounting hole. The first annular groove 103 is located above the second annular groove 104. The sterilization channel 102 communicates directly with the first annular groove 103. The second annular groove 104 corresponds to the position of the second gap 132, so that the second annular groove 104 communicates with the second gap 132. One end of the air inlet 101 penetrates the bottom of the second annular groove 104, so that the air inlet 101 communicates directly with the second annular groove 104. By providing the second annular groove 104, the high-pressure air and sterilization gas entering from the air inlet 101 can flow to the area around the piston shaft 11 through the second annular groove 104. Correspondingly, the piston shaft 11 is provided with a plurality of connecting holes 111, which are spaced apart along the circumference of the piston shaft 11. One end of each connecting hole 111 is connected to the air blowing channel 14, and the other end is connected to the second gap 132, and faces the second annular groove 104. High-pressure air or sterilizing gas in the second annular groove 104 enters the air blowing channel 14 through the plurality of connecting holes 111. In the bottle blowing state, the second sealing ring 16 and the third sealing ring 17 abut against the wall of the mounting hole, that is, the second sealing ring 16 and the third sealing ring 17 are in a sealed state, and the second gap 132 is connected to the air blowing channel 14 through the connecting holes 111. High-pressure gas flows sequentially through the air inlet 101, the second gap 132, the connecting holes 111, and the air blowing channel 14. In the sterilization state, the piston shaft 11 moves up and down within the mounting hole. The second sealing ring 16 moves to the opening position of the first annular groove 103, thus spacing the second sealing ring 16 from the wall of the mounting hole. The first gap 131 and the second gap 132 are connected through the first annular groove 103. The third sealing ring 17 moves to the opening position of the second annular groove 104, thus spacing the third sealing ring 17 from the wall of the mounting hole. The second gap 132 and the third gap 133 are connected through the second annular groove 104. In this state, the first gap 131, the second gap 132, and the third gap 133 are all connected to the sterilization channel 102. Part of the sterilization gas flows sequentially through the air inlet 101, the gap 13, the connecting hole 111, and the blowing channel 14, while the other part of the sterilization gas flows sequentially through the air inlet 101, the gap 13, and the sterilization channel 102.

[0029] Since the high-pressure gas directly contacts the second sealing ring 16 and the third sealing ring 17, to avoid forming a sterilization dead zone on the contact surfaces of the second sealing ring 16 and the third sealing ring 17, the second sealing ring 16 and the third sealing ring 17 move synchronously with the piston shaft 11, so that the second sealing ring 16 and the third sealing ring 17 can move to the first annular groove 103 and the second annular groove 104, so as to expose the second sealing ring 16 and the third sealing ring 17 to the sterilization gas. The second sealing ring 16 and the third sealing ring 17 are inserted into the outer wall of the piston shaft 11 so as to move synchronously with the piston shaft 11. In order to make the entire gap 13 a sealed state, the first sealing ring 15 and the fourth sealing ring 18 are inserted into the wall of the mounting hole, and the ends of the first sealing ring 15 and the fourth sealing ring 18 away from the cylinder body 10 abut against the outer wall of the piston shaft 11 to achieve a seal. When the piston shaft 11 rises and falls, the first sealing ring 15 and the fourth sealing ring 18 cannot move.

[0030] To improve the flow efficiency of sterilizing gas, the sterilization channel 102 includes two inlet ends and one outlet end. One inlet end of the sterilization channel 102 is connected to the first annular groove 103, and the other inlet end is connected to the third gap 133. During sterilization, sterilizing gas can flow into the sterilization channel 102 from both ends of the gap 13. The outlet end of the sterilization channel 102 is connected to the outside of the cylinder 10 to discharge the sterilizing gas. The outlet end of the sterilization channel 102 forms a channel outlet 1021, through which the sterilizing gas is discharged.

[0031] Specifically, refer to Figure 4 As shown, the blow molding unit 1 also includes a blow nozzle 19, which is mounted at the bottom end of the piston shaft 11. A blow nozzle 191 is formed within the blow nozzle 19, and the blow nozzle 191 communicates with the blow channel 14. The blow nozzle 19 is used to directly contact the preform, so that high-pressure air discharged from the blow channel 14 is blown onto the preform through the blow nozzle 191.

[0032] Specifically, refer to Figure 2 As shown, the protective cover 5 includes a cover body 51 and a sterilization inlet connector 52, a sterilization outlet connector 53, and a sterile gas connector 54 disposed on the cover body 51. The sterilization inlet connector 52 and the sterilization outlet connector 53 are located at opposite ends of the cover body 51 and communicate with the internal space of the cover body 51. The sterilization inlet connector 52 is connected to a gas source. During sterilization, the gas source supplies sterilizing gas to the sterilization inlet connector 52. The sterilizing gas sterilizes the components inside the cover body 51 and then exits through the sterilization outlet connector 53. The gas source also stores and supplies sterile gas. The sterile gas connector 54 is connected to the gas source. During bottle blowing, the gas source supplies sterile gas to the sterile gas connector 54, creating a positive pressure state inside the cover body 51. The sterile gas overflows from the installation gaps in the cover body 51 to prevent external sterile gases or other media from entering the protective cover 5.

[0033] Specifically, refer to Figure 1 and Figure 5 As shown, the blow molding machine also includes a support frame 6, which provides overall support. The blow molding unit 1, the lead screw drive mechanism 2, the cam drive mechanism 3, the lifting cylinder 4, and the protective cover 5 are all mounted on the support frame 6. The lead screw drive mechanism 2 includes a first guide rail 21, a lead screw 22, a slider assembly 23, a motor 24, and a baffle 25. The first guide rail 21 is vertically mounted on the support frame 6, and the slider assembly 23 is slidably connected to the first guide rail 21. The lead screw 22 passes through the slider assembly 23 and is threadedly connected to it. The motor 24 is located at the top of the support frame 6 and is connected to the lead screw 22 to drive it to rotate. The rotation of the lead screw 22 drives the slider assembly 23 to slide along the length direction (vertical direction) of the first guide rail 21. The slider assembly 23 includes a slider body, a connector 231, and a connecting nut 232. The slider body is slidably connected to the first guide rail 21, and the connecting nut 232 is mounted on the slider body and is used to mount the lead screw 22. The connector 231 is located on the side of the slider body facing away from the support 6, and the tension rod 12 is mounted on the connector 231 by fasteners. The slider body has a clearance hole 233, and a baffle 25 passes through the slider body and can slide relative to it. The baffle 25 is located between the connector 231 and the connecting nut 232. The protective cover 5 covers the periphery of the lead screw drive mechanism 2. When sterilizing gas is introduced into the protective cover 5, the baffle 25 acts as a barrier to prevent a large amount of sterilizing gas from directly impacting the lead screw 22 and causing corrosion. Correspondingly, the protective cover 5 is a semi-enclosed structure, with an opening at the end facing the support 6. The open end of the protective cover 5 is used for connection and fixation to the support 6. Therefore, the baffle 25 is located on the side of the lead screw 22 facing the protective cover 5 to block the sterilizing gas inside the protective cover 5.

[0034] Specifically, refer to Figure 1 and Figure 2As shown, the blow molding machine also includes a cam drive mechanism 3 and a lifting cylinder 4. In blow molding mode, the cam drive mechanism 3 drives the piston shaft 11 to move up and down; in sterilization mode, the lifting cylinder 4 drives the piston shaft 11 to move up and down. The cam drive mechanism 3 includes an annular cam 31, a second guide rail 32, a slide block 33, a follower wheel 34, and a spring 35. The second guide rail 32 is vertically mounted on the support 6, and the slide block 33 is slidably connected to the second guide rail 32 so that the slide block 33 can slide along the length direction (vertical direction) of the second guide rail 32. The slide block 33 is connected to the top end of the piston shaft 11, and the sliding of the slide block 33 drives the piston shaft 11 to move up and down. The follower wheel 34 is rotatably mounted on the slide block 33. The annular cam 31 has a circular structure, and the top of the annular cam 31 forms a wheel surface for abutting against the follower wheel 34. The follower wheel 34 abuts against the wheel surface of the annular cam 31. The annular cam 31 has a flat section, a rising section, and a falling section on its surface, creating an undulating structure. During bottle blowing, the support 6 rotates along the circumference of the annular cam 31, causing the follower wheel 34 to roll on the surface of the annular cam 31. During the rolling of the follower wheel 34, it generates a lifting motion, thereby driving the piston shaft 11 to lift and lower via the cam drive mechanism 3. The lifting stroke of the piston shaft 11 matches the shape of the annular cam 31's surface. In this embodiment, the cam drive mechanism 3 drives the piston shaft 11 to lift and lower during the first stroke. The two ends of the spring 35 are connected to the slide 33 and the support 6 respectively, achieving an elastic connection between the slide 33 and the support 6. The spring 35 possesses elastic potential energy to drive the slide 33 downwards. By setting the spring 35, a downward pulling force is applied to the slide 33, ensuring that the follower wheel 34 always remains in contact with the annular cam 31.

[0035] The lifting cylinder 4 is selectively connected to the piston shaft 11 and drives the piston shaft 11 to move up and down. In the bottle blowing state, the output end of the lifting cylinder 4 is spaced apart from the slide 33, so that the lifting cylinder 4 is separated from the slide 33 during bottle blowing, avoiding interference with the operation of the cam drive mechanism 3. In the sterilization state, the output end of the lifting cylinder 4 extends, abuts against the slide 33, and drives the piston shaft 11 to rise. The lifting drive 4 drives the piston shaft 11 to move up and down in the second stroke. The second stroke is longer than the first stroke. (See reference...) Figure 3 and Figure 4As shown, in the blow molding state, the piston shaft 11 moves up and down, and the stroke of the piston shaft 11 is the first stroke. In this state, the second sealing ring 16 and the third sealing ring 17 on the piston shaft 11 can abut against the wall of the mounting hole at both the highest and lowest positions, so that the second sealing ring 16 and the third sealing ring 17 are in a sealing state. In the sterilization state, the piston shaft 11 moves up and down, and the stroke of the piston shaft 11 is the second stroke. In this state, when the second sealing ring 16 and the third sealing ring 17 rise to the highest position, the second sealing ring 16 and the third sealing ring 17 move to the groove opening positions of the first annular groove 103 and the second annular groove 104, respectively, so that the second sealing ring 16 and the third sealing ring 17 are in a non-sealing state.

[0036] Specifically, refer to Figure 2 and Figure 6 As shown, the blow molding machine also includes a sealing assembly 7 and a blow molding die 8. The blow molding die 8 is located below the blow molding unit 1 and is used to receive the preform to blow it into a bottle that matches the shape of its inner cavity. The sealing assembly 7 is mounted on the support 6 and is positioned near the air nozzle 19. The sealing assembly 7 includes a drive unit 71, a cup lid 72, a pipe connector 73, and a cover plate 74. The drive unit 71 is a motor, and the cup lid 72 is mounted on the output end of the drive unit 71. The drive unit 71 drives the cup lid 72 to rotate horizontally. The cup lid 72 is used for selective communication with the air blowing channel 14. In the blow molding state, the cup lid 72 rotates to a position away from the air nozzle 19, disconnecting it from the air blowing channel 14. In the sterilization state, the cup lid 72 rotates below the air nozzle 19 and connects to it, so that the cup lid 72 communicates with the air blowing channel 14 through the air nozzle 19. A pipe connector 73 is disposed on and communicates with the cup lid 72, and is used to discharge sterilizing gas. A sealing assembly 7 is used to receive the sterilizing gas discharged from the blowing channel 14, preventing the sterilizing gas from entering the external environment. A cover plate 74 is fixedly mounted on the drive component 71. During blow molding, the cup lid 72 rotates to the underside of the cover plate 74 to seal the inlet end of the cup lid 72. Correspondingly, the blow molding machine also includes a recovery pipeline connected to the pipe connector 73 to collect the sterilizing gas after sterilization. The recovery pipeline is also connected to the channel outlet 1021 on the cylinder 10 to collect the sterilizing gas discharged from the sterilization channel 102. The recovery pipeline is also connected to the sterilization outlet connector 53 in the protective cover 5 to collect the sterilizing gas discharged from the protective cover 5.

[0037] like Figures 1 to 4As shown, the present invention also provides a sterilization method for a blow molding machine, applicable to the blow molding machine. The sterilization method includes: during blow molding, a gas source inputs high-pressure air into the air inlet 101, and the high-pressure air is blown towards the preform through the air blowing channel 14. Simultaneously, a sterilizing gas is input into the protective cover 5, creating a positive pressure state inside the protective cover 5. During sterilization, the gas source inputs sterilizing gas into both the air inlet 101 and the protective cover 5, so that the sterilizing gas sterilizes the area through which the high-pressure air flows, and also sterilizes the internal space of the protective cover 5.

[0038] Specifically, a blow molding machine has two operating states: one is the blow molding state, which uses high-pressure air to blow-form the preform; the other is the sterilization state, which stops blow molding and sterilizes the blow molding machine.

[0039] During the blow molding process, the support 6 moves around the circumference of the annular cam 31. Driven by the cam drive mechanism 3, the piston shaft 11 moves up and down within the cylinder 10. The first stroke is the lifting stroke of the piston shaft 11, during which the second sealing ring 16 and the third sealing ring 17 remain in contact with the wall of the mounting hole. At this time, the air inlet 101, the second gap 132, the connecting hole 111, and the blowing channel 14 are in a connected state. The air source inputs high-pressure air into the air inlet 101, and the high-pressure air is blown towards the preform through the second gap 132, the connecting hole 111, and the blowing channel 14. The preform expands within the blow molding die 8 and forms a bottle that fits into the inner cavity of the blow molding die 8. Simultaneously, the screw drive mechanism 2 drives the tension rod 12 to move up and down, extending the bottom end of the tension rod 12 into the preform to promote preform forming. At the same time, the air source inputs sterile gas into the protective cover 5. The sterile gas can be sterilized air. Sterile gas is used to create a positive pressure inside the protective cover 5, preventing external bacteria-containing gas from entering the protective cover 5.

[0040] During sterilization, the support 6 stops moving. The lifting cylinder 4 lifts the slide 33 upwards, causing the follower wheel 34 to disengage from the annular cam 31. That is, the lifting cylinder 4 drives the piston shaft 11 to rise, and the lifting stroke of the piston shaft 11 is the second stroke. At this time, the second sealing ring 16 moves to the opening position of the first annular groove 103, and the third sealing ring 17 moves to the opening position of the second annular groove 104. The second sealing ring 16 and the third sealing ring 17 lose their sealing function, and the entire gap 13 is connected to the sterilization channel 102 and the air blowing channel 14. The air source inputs sterilizing gas into the air inlet 101. Part of the sterilizing gas flows through the gap 13, the connecting hole 111, and the air blowing channel 14, while the other part flows through the gap 13 and the sterilization channel 102. During this process, the sterilizing gas not only sterilizes the area through which the high-pressure air flows but also sterilizes the contact surface of the second sealing ring 16 and the third sealing ring 17, thereby reducing sterilization dead zones and improving sterilization quality. At the same time, the gas source inputs sterilizing gas into the protective cover 5, and uses the sterilizing gas to sterilize the piston shaft 11 and the tension rod 12 located inside the protective cover 5, so as to ensure the comprehensive sterilization of the blow molding unit 1.

[0041] The beneficial effects of this embodiment are as follows: By introducing sterilizing gas into the air inlet 101, the sterilizing gas is used to sterilize the area through which the high-pressure gas passes in the blow molding unit 1, preventing bacteria generated in the blow molding unit 1 from entering the bottle with the high-pressure air. The sterilizing gas can penetrate deep into the channels inside the blow molding unit 1, which helps to reduce sterilization dead zones and improve sterilization quality. Furthermore, by setting up a protective cover 5, the piston shaft 11 and the tension rod 12 extending to the outside of the cylinder 10 are protected against bacteria. Sterilizing gas is introduced into the protective cover 5 during sterilization to achieve more comprehensive sterilization of the piston shaft 11 and the tension rod 12, thereby improving the sterilization quality of the entire blow molding unit 1.

[0042] Although embodiments of the invention have been described above with reference to the accompanying drawings, the invention is not limited to the above embodiments, but can be made in various forms, and those skilled in the art will understand that the invention can be implemented in other specific forms without changing the technical spirit or essential characteristics of the invention. Therefore, it should be understood that the above embodiments are exemplary in all respects and not restrictive.

Claims

1. A blow molding machine, characterized in that, include: A blow molding unit includes a cylinder, a piston shaft, and a tension rod. The cylinder has an air inlet. The piston shaft passes through the cylinder and there is a gap between the piston shaft and the cylinder. The tension rod passes through the piston shaft and there is a blow molding channel between the piston shaft and the tension rod. The blow molding channel and the air inlet are both connected to the gap. A lead screw drive mechanism is connected to the tension rod, and the lead screw drive mechanism is used to drive the tension rod to move up and down; A protective cover is provided around the screw drive mechanism, and the top ends of the tension rod and the piston shaft are located inside the protective cover; The gas source is connected to the air inlet and the protective cover. In the blow molding state, the gas source inputs high-pressure air into the air inlet; in the sterilization state, the gas source inputs sterilizing gas into the air inlet and the protective cover.

2. The blow molding machine according to claim 1, characterized in that, The gaps include a first gap, a second gap, and a third gap arranged sequentially along the axial direction of the piston shaft. The air inlet and the air blowing channel are both connected to the second gap. A first sealing ring, a second sealing ring, a third sealing ring, and a fourth sealing ring are fitted around the periphery of the piston shaft. The first gap is located between the first sealing ring and the second sealing ring, the second gap is located between the second sealing ring and the third sealing ring, and the third gap is located between the third sealing ring and the fourth sealing ring. In the blow-blowing state, the first gap and the third gap are both sealed and isolated from the second gap. In the sterilization state, the first gap and the third gap are both connected to the second gap.

3. The blow molding machine according to claim 2, characterized in that, The cylinder body is provided with a sterilization channel and a mounting hole for the piston shaft to pass through. The wall of the mounting hole is provided with a first annular groove and a second annular groove. The first annular groove communicates with the sterilization channel, and the second annular groove communicates with the air inlet. In the blowing state, the second sealing ring and the third sealing ring abut against the wall of the mounting hole so that the second gap communicates only with the blowing channel. In the sterilization state, the second sealing ring and the third sealing ring move to the groove opening positions of the first annular groove and the second annular groove, respectively, so that the first gap, the second gap and the third gap all communicate with the sterilization channel.

4. The blow molding machine according to claim 3, characterized in that, The sterilization channel includes two inlet ends and one outlet end. One inlet end of the sterilization channel is connected to the first annular groove, the other inlet end is connected to the third gap, and the outlet end of the sterilization channel is connected to the outside of the cylinder.

5. The blow molding machine according to claim 3, characterized in that, It also includes a cam drive mechanism and a lifting cylinder. The cam drive mechanism is connected to the piston shaft and is used to drive the piston shaft to move up and down in a first stroke. The lifting cylinder is selectively connected to the piston shaft and is used to drive the piston shaft to move up and down in a second stroke, which is longer than the first stroke.

6. The blow molding machine according to claim 5, characterized in that, It also includes a bracket. The cam drive mechanism includes a second guide rail, a slide, a follower wheel, and an annular cam. The second guide rail is vertically mounted on the bracket. The slide is slidably connected to the second guide rail and elastically connected to the bracket. The follower wheel is rotatably mounted on the slide. The top surface of the annular cam abuts against the follower wheel. The top of the piston shaft is connected to the slide, and the top of the piston shaft is located inside the protective cover.

7. The blow molding machine according to any one of claims 1 to 6, characterized in that, During the blown bottle operation, the gas source supplies sterile gas to the protective cover to create a positive pressure environment inside the protective cover.

8. The blow molding machine according to any one of claims 1 to 6, characterized in that, It also includes a sealing assembly for selectively communicating with the air blowing channel and for receiving sterilizing gas discharged from the air blowing channel.

9. The blow molding machine according to any one of claims 1 to 5, characterized in that, It also includes a bracket. The lead screw drive mechanism includes a first guide rail, a lead screw, a slider assembly, a motor, and a baffle. The first guide rail is vertically mounted on the bracket. The slider assembly is slidably connected to the first guide rail. The lead screw passes through the slider assembly and is threadedly connected to the slider assembly. The motor is connected to the lead screw to drive the lead screw to rotate. The top end of the tension rod is connected to the slider assembly. The baffle is movably mounted on the slider assembly and is located on the side of the lead screw facing the protective cover.

10. A sterilization method for a blow molding machine, characterized in that, The blow molding machine according to any one of claims 1 to 9 includes: in the blow molding state, a gas source inputs high-pressure air into the air inlet, the high-pressure air is blown towards the preform through the blowing channel, and at the same time, the gas source inputs sterile gas into the protective cover, and makes the internal space of the protective cover positive pressure; in the sterilization state, the gas source inputs sterilizing gas into the air inlet and the protective cover, so that the sterilizing gas sterilizes the area through which the high-pressure air flows, and the sterilizing gas sterilizes the internal space of the protective cover.

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