Plastic bottle blank high-pressure inner container with metal pipe orifice

Abstract

The utility model relates to the technical field of blowing of high-pressure storage tanks, in particular to a plastic bottle blank high-pressure inner container with a metal pipe opening. The high-pressure inner container comprises an inner container body formed by blowing a plastic bottle blank and a metal pipe opening installed at an opening of the inner container body, a turned-over edge turned over outwards is arranged at the opening of the inner container body, and the metal pipe opening comprises a locking block and a metal valve block which are coaxially installed at the opening of the inner container body; the locking block is an annular body with an external thread, the inner ring diameter of the locking block is matched with the outer diameter of the opening of the inner container, the upper end of the locking block is provided with a clamping groove matched with the turned-over edge, and the lower end of the locking block is provided with a tool inserting hole; the metal valve block is of a tubular structure coaxially arranged with the opening of the inner container, the lower end of the metal valve block is fixedly connected with a spherical crown-shaped skirt edge, the inner side face of the skirt edge is provided with an installation groove for containing the locking block, and the side wall of the installation groove is provided with an installation groove internal thread matched with the locking block external thread. According to the utility model, the inner container formed by blowing a plastic bottle blank can be tightly connected with the metal bottle opening; the metal pipe orifice has the characteristics of light weight, low cost and easiness in processing and forming of the PET material, and also has the advantages of high strength and good sealing performance of the metal pipe orifice.

Description

Technical Field

[0001] This utility model relates to the field of high-pressure storage tank blowing technology, specifically a high-pressure inner liner of a plastic preform with a metal nozzle. Background Technology

[0002] Hydrogen for vehicles is stored under high pressure in hydrogen storage cylinders. Currently, there are four types of hydrogen storage cylinders: all-metal cylinders, metal-lined fiber-wound cylinders, metal-lined fully-wound fiber cylinders, and non-metal-lined fully-wound fiber cylinders. All-metal cylinders, metal-lined fiber-wound cylinders, and metal-lined fully-wound fiber cylinders have a large density ratio, making it difficult to meet the requirements for hydrogen storage density per unit mass. They are not ideal for use in on-board hydrogen supply systems. Non-metal-lined fully-wound fiber cylinders have the defect of a weak connection between the metal cylinder neck and the non-metallic liner, which easily leads to hydrogen leakage risk during use and poses a great safety hazard. Chinese patent application 2019101499077 discloses a "Hydrogen Storage Cylinder with Carbon Fiber Fully Wound Plastic Liner," publication number CN109751506A. This hydrogen storage cylinder includes a metal neck, a plastic liner, and a metal cover. The metal cover has a through-hole with vertical threads, and its edges have downward-bent vertical flanges. The metal neck and plastic liner are integrally blow-molded. The top of the plastic liner has an inwardly recessed annular groove. The inner wall of the metal neck has internal threads that mate with a valve, and the outer wall has external threads that mate with the through-hole. When the metal cover is screwed tightly onto the metal neck, the vertical flanges are engaged in the annular groove. The hydrogen storage cylinder uses claws on the metal cover to grip the shoulder of the plastic liner, achieving a secure connection and improved safety. Because the claws on the metal cover need to engage with the annular receiving groove on the shoulder of the plastic inner liner to a sufficient depth without penetrating it, the shoulder of the plastic inner liner must be thicker than other parts, increasing its weight. Furthermore, when the plastic inner liner is subjected to significant axial force, the claws on the metal cover still risk detaching from the annular receiving groove. Therefore, the connection between the metal nozzle of the hydrogen storage cylinder and the plastic inner liner remains a weak point in terms of pressure resistance and sealing, requiring further improvement in connection reliability. My other Chinese patent application, 2024113823034, discloses "Blow-molded High-Pressure Inner Liner with Pre-installed Metal Nozzle and Production Method," publication number CN119084793A. The high-pressure inner liner includes a blow-molded inner liner and a metal nozzle installed at the opening of the blow-molded inner liner. The metal nozzle includes a fixing member coaxially mounted on the inner side of the neck, an outer clamp fitted on the outer side of the neck, and a locking nut threadedly connected to the fixing member. The inner end of the fixing member has a disc that engages with the opening of the blow-molded inner liner, and the outer end of the fixing member extends out of the blow-molded inner liner and is provided with external threads for installing the locking nut. The lower end of the outer clamp and the disc together form a clamping mechanism for the blow-molded inner liner, and the upper end of the outer clamp abuts against the bottom of the locking nut. This high-pressure inner liner allows for the pre-installation of a larger fixing member within the blow-molded inner liner. The metal nozzle connection is secure, has good sealing performance, and high compressive strength. There are no special requirements for the strength of the shoulder and neck of the blow-molded inner liner, which helps to reduce the amount of plastic material used in the inner liner and reduce the overall weight.Commonly used raw materials for blow molding include thermoplastics such as polyethylene terephthalate (PET), polypropylene (PP), and polycarbonate (PC). The manufacture of these plastic bottles typically involves multiple processes, including injection molding, stretching, and blow molding. First, injection molding preforms plastic granules into solid preforms, which are then heated, stretched, and blow-molded. The method disclosed in patent application No. 2024113823034 is not suitable for preformed solid preforms. Utility Model Content

[0003] To address the problems of the prior art, this utility model provides a high-pressure inner liner for a plastic preform with a metal nozzle. The metal nozzle has a strong connection, good sealing performance, and high compressive strength. While ensuring a strong connection and good sealing performance, the amount of material used in the plastic inner liner is minimized and the overall weight is reduced.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] The high-pressure inner liner of the plastic preform with a metal nozzle of this utility model includes an inner liner blown from a plastic preform and a metal nozzle installed at the opening of the inner liner. The opening of the inner liner is provided with an outwardly folded flange. The metal nozzle includes a locking block and a metal valve block coaxially installed at the opening of the inner liner. The locking block is an externally threaded collar provided on the outer ring surface of the flange. The metal valve block is a tubular structure coaxially provided with the opening of the inner liner. The lower end of the metal valve block is fixedly connected to a spherical crown-shaped skirt. The inner side of the skirt is provided with a mounting groove for accommodating the locking block. The side wall of the mounting groove is provided with an internal thread of the mounting groove that adapts to the external thread of the locking block.

[0006] With the above structural design, the high-pressure inner liner of the plastic preform with a metal nozzle combines the advantages of PET material (light weight, low cost, and easy processing and molding) with the high strength and good sealing performance of the metal nozzle. Furthermore, the connection between the PET material and the metal nozzle is structurally robust, provides excellent sealing performance and high compressive strength, and facilitates the blow molding of the plastic preform.

[0007] Preferably, the locking block is a ring-shaped body with external threads, the inner ring diameter of the locking block is adapted to the outer diameter of the inner liner opening, the upper end of the locking block has a groove adapted to the flange, and the lower end has a tool insertion hole.

[0008] With the above structural design, the locking block and the flange at the inner liner opening adopt a separate assembly structure.

[0009] Preferably, the lower end face of the metal valve block extends into the mounting groove, and the lower end face of the metal valve block is flush with the lower end face of the mounting groove. The outer diameter of the lower end of the metal valve block located in the mounting groove is adapted to the inner diameter of the inner liner opening.

[0010] With the above structural design, after assembly, the lower end of the metal valve block extends into the mouth of the plastic preform, supporting the mouth from inside the plastic preform and preventing deformation of the mouth; the specifications of the gas cylinder interface are not affected by the preform, which is conducive to standardizing the specifications of the gas cylinder interface.

[0011] Preferably, an O-ring is provided at the junction of the bottom of the mounting groove and the metal valve block.

[0012] The above structural design can improve the sealing effect between the plastic preform and the metal nozzle.

[0013] Preferably, the inner cavity of the metal valve block is provided with an internal thread.

[0014] The above structural design allows for easy connection between the metal valve block and the blow molding machine, as well as easy connection between the finished high-pressure inner liner and gas-using equipment such as gas valves.

[0015] Preferably, the thickness of the skirt gradually decreases from the inside to the outside.

[0016] By adopting the above structural design, the weight can be further reduced while ensuring the structural strength of the metal pipe.

[0017] Preferably, the locking block and the flange are an integrated structure.

[0018] By adopting the above structural design, the number of parts can be further reduced, production efficiency can be improved, and the sealing performance of the bottle mouth can be enhanced.

[0019] Compared with the prior art, the beneficial effects of this utility model are: it can tightly connect the inner liner made of plastic preform to the metal bottle mouth; it has the advantages of plastic material being lightweight, low-cost, and easy to process and mold, as well as the advantages of metal pipe mouth being strong and having good sealing performance; the specifications of the gas valve interface are not affected by the bottle body, making it convenient to use a uniform gas cylinder interface on bottles of different specifications; at the same time, the connection between the plastic material and the metal pipe mouth has a strong structure, good sealing performance, high compressive strength, and facilitates the organization of preform blowing. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of a plastic bottle preform assembled with a metal tube opening according to an embodiment of the present invention.

[0021] Figure 2 This is a cross-sectional view of the bottle after it has been blown into shape.

[0022] Figure 3 This is a schematic diagram of the assembly structure of the plastic bottle preform and the metal nozzle.

[0023] Figure 4 This is a schematic diagram of the three-dimensional structure of the locking block.

[0024] Figure 5 This is a three-dimensional structural diagram of the locking block from another angle.

[0025] Figure 6 This is a three-dimensional structural diagram of a metal valve block.

[0026] Figure 7 This is a three-dimensional structural diagram of the metal valve block from another angle.

[0027] Figure 8 This is a partial cross-sectional view of another embodiment of the present invention after the plastic bottle preform and the metal tube opening are assembled. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] like Figure 1 , Figure 2 As shown, the high-pressure inner liner with a metal nozzle of the present invention includes an inner liner 1 blown from a plastic preform 19 and a metal nozzle installed at the opening of the inner liner 1; the plastic preform 19 can be a preform injection molded from PET, PC, PP or other polymer materials. The opening of the inner liner 1 is provided with an outwardly folded flange 2, which is annular and fixedly connected to the uppermost end of the opening of the inner liner 1. The metal nozzle includes a locking block 3 and a metal valve block 4 coaxially installed at the opening of the inner liner 1; the metal valve block 4 is used to connect to the gas valve of the gas-using equipment; such as Figure 4 , Figure 5 As shown, the locking block 3 is an externally threaded collar disposed on the outer ring surface of the flange 2. In one embodiment of this utility model, the locking block 3 is a ring-shaped body with external threads. The inner ring diameter of the locking block 3 is adapted to the outer diameter of the opening of the inner liner 1, so that the locking block 3 can be fitted onto the opening of the inner liner 1 and has a certain sealing performance. The upper end of the locking block 3 has a groove 5 adapted to the flange 2, and the lower end has a tool insertion hole 6. The tool insertion hole 6 is a cylindrical blind hole, which can also be an elliptical or polygonal cylindrical structure. The depth of the groove 5 is adapted to the thickness of the flange 2. When the locking block 3 is fitted onto the opening of the inner liner 1, the flange 2 is precisely embedded in the groove 5, and the upper end surface of the flange 2 is flush with the upper end surface of the locking block 3, and the two are located on the same plane.

[0030] As one embodiment of this utility model, such as Figure 1 , Figure 2 As shown, the locking block 3 adopts a metal structure independent of the flange 2 and the plastic preform 19, which has higher mechanical strength.

[0031] like Figure 8 As shown, in another embodiment of this utility model, the locking block 3 and the flange 2 are an integrated structure. In this embodiment, the material of the locking block 3 is the same as that of the flange 2 and the plastic preform 19, and it is fused with the flange 2 to form a whole. The locking block 3 and the flange 2 can be generated simultaneously when producing the plastic preform 19, or the plastic preform 19 with the flange 2 and the locking block 3 with external threads can be produced separately. After the locking block 3 and the flange 2 are assembled, they are welded and fused into a whole by methods such as ultrasonic welding.

[0032] like Figure 6 , Figure 7 As shown, the metal valve block 4 located at the upper end of the inner liner 1 is a tubular structure coaxially arranged with the opening of the inner liner 1. A spherical skirt 7 is fixedly connected to the lower end of the metal valve block 4. The skirt 7 and the metal valve block 4 are an integral structure. The thickness of the skirt 7 gradually decreases from the inside to the outside; that is, the thickness of the skirt 7 is smaller closer to the edge. In actual use, because the metal valve block 4 is used to directly connect to external equipment and also serves as the gas inlet and outlet channel, the metal valve block 4 bears the greatest pressure. The skirt 7 is subjected to pressure transmitted by the metal valve block 4, and the pressure transmitted to the edge of the skirt 7 is smaller the further away from the metal valve block 4 it is. Reducing the thickness of the edge of the skirt 7 not only does not reduce the overall structural strength but also reduces weight and production costs.

[0033] The inner side of the skirt 7 is provided with a mounting groove 8 for accommodating the locking block 3. The side wall of the mounting groove 8 is provided with an internal thread 9 that adapts to the external thread of the locking block 3. During assembly, the locking block 3 is placed in the mounting groove 8, and the locking block 3 is rotated using a tool inserted into the tool socket 6, screwing the external thread of the locking block 3 into the internal thread 9 of the mounting groove until the upper end of the locking block 3 abuts against the bottom of the mounting groove 8. In this embodiment, four tool sockets 6 are evenly distributed around the lower end of the locking block 3. An assembly tool with 2-4 inserts on the handle can be used; the inserts on the handle are inserted into at least two of the tool sockets 6 of the locking block 3, and rotating the handle will rotate the locking block 3. Of course, as another embodiment of this utility model, the lower end of the locking block 3 can also have two or three tool sockets 6.

[0034] As a further improvement of this utility model, the lower end face of the metal valve block 4 extends into the mounting groove 8, and the lower end face of the metal valve block 4 is flush with the lower end face of the mounting groove 8. The outer diameter of the lower end of the metal valve block 4 located in the mounting groove 8 is adapted to the inner diameter of the opening of the inner liner 1. Thus, as... Figure 1 , Figure 2 As shown, whether before or after blow molding, the lower end of the metal valve block 4 can extend into the interior of the opening of the plastic preform 19 or the inner liner 1, serving to support and seal the bottle mouth. Furthermore, to further improve the sealing performance at the bottle mouth, an O-ring 10 is provided at the connection between the bottom of the mounting groove 8 and the metal valve block 4. This O-ring 10 is fitted onto the metal valve block 4 and located at the bottom of the mounting groove 8. After the metal nozzle is assembled with the plastic preform or inner liner 1, the O-ring 10 surrounds the opening of the plastic preform or inner liner 1, sealing the bottle mouth.

[0035] In addition, in order to facilitate the connection of valves to gas-using equipment, the inner cavity of the metal valve block 4 is provided with an internal thread 12.

[0036] The production method of the high-pressure inner liner of the plastic preform with a metal nozzle according to this utility model includes the following steps:

[0037] 1) Prepare a metal nozzle and a plastic preform. The plastic preform 19 has an outwardly folded flange 2 at its opening. The plastic preform 19 has a cylindrical structure or a conical structure with a smaller outer diameter at the lower end and a larger outer diameter at the upper end, so that a ring with an inner diameter that matches the opening of the plastic preform 19 can be fitted onto it. The metal nozzle includes a locking block 3 and a metal valve block 4 coaxially mounted at the opening of the plastic preform 19. The locking block 3 is a ring with external threads, and the inner ring diameter of the locking block 3 is adapted to... The outer diameter of the opening of the plastic bottle preform 19; the upper end of the locking block 3 has a groove 5 adapted to the flange 2, and the lower end has a tool insertion hole 6, which is used to insert a locking tool to rotate the locking block 3; the metal valve block 4 is a tubular structure coaxially arranged with the opening of the plastic bottle preform 19; the lower end of the metal valve block 4 is fixedly connected to a spherical skirt 7; the inner side of the skirt 7 is provided with a mounting groove 8 to accommodate the locking block 3; the side wall of the mounting groove 8 is provided with a mounting groove internal thread 9 adapted to the external thread of the locking block 3;

[0038] 2) Connect the metal valve block 4 to the opening of the plastic bottle preform 19 so that the upper end of the opening of the plastic bottle preform 19 abuts against the bottom of the mounting groove 8. Insert the locking block 3 from the lower end of the plastic bottle preform into the opening of the plastic bottle preform so that the flange 2 is inserted into the slot 5.

[0039] 3) Install the locking block 3 into the mounting groove 8 on the inner side of the skirt 7, and tighten the locking block 3 with a locking tool so that the upper end of the locking block 3 abuts against the bottom of the mounting groove 8.

[0040] 4) Place the plastic preform 19 with the metal nozzle attached into the baking equipment and heat the plastic preform at the set temperature and time to soften it.

[0041] 5) The heated plastic preform with metal nozzle is placed into the blow molding mold. The blow molding equipment injects compressed air into the plastic preform through the metal valve block 4, causing the plastic preform to expand and fit against the inner wall of the blow molding mold to form the inner liner 1.

[0042] 6) Demold and remove the blow-molded inner liner;

[0043] 7) Wrap and wrap a carbon fiber layer around the outer surface of the inner liner 1.

[0044] In addition, to improve the sealing effect, an O-ring 10 is embedded on the bottom surface of the mounting groove 8 of the prepared metal valve block 4 in step 1).

[0045] Contents not described in detail in this specification are existing technologies known to those skilled in the art. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-pressure inner liner for a plastic preform with a metal nozzle, comprising an inner liner (1) blown from a plastic preform and a metal nozzle installed at the opening of the inner liner (1), wherein the opening of the inner liner (1) is provided with an outwardly folded flange (2), characterized in that: The metal pipe includes a locking block (3) and a metal valve block (4) coaxially mounted at the opening of the inner liner (1); the locking block (3) is an external threaded collar set on the outer ring surface of the flange (2); the metal valve block (4) is a tubular structure coaxially set with the opening of the inner liner (1), and a spherical skirt (7) is fixedly connected to the lower end of the metal valve block (4). The inner side of the skirt (7) is provided with an installation groove (8) for accommodating the locking block (3), and the side wall of the installation groove (8) is provided with an installation groove internal thread (9) adapted to the external thread of the locking block (3).

2. The high-pressure inner liner of the plastic preform with a metal nozzle according to claim 1, characterized in that: The locking block (3) is a ring-shaped body with external threads. The inner ring diameter of the locking block (3) is adapted to the outer diameter of the opening of the inner liner (1). The upper end of the locking block (3) has a slot (5) adapted to the flange (2), and the lower end has a tool insertion hole (6).

3. The high-pressure inner liner of the plastic preform with a metal nozzle according to claim 2, characterized in that: The lower end face of the metal valve block (4) extends into the mounting groove (8), and the lower end face of the metal valve block (4) is flush with the lower end face of the mounting groove (8). The outer diameter of the lower end of the metal valve block (4) located in the mounting groove (8) is adapted to the inner diameter of the opening of the inner liner (1).

4. The high-pressure inner liner of the plastic preform with a metal nozzle according to claim 3, characterized in that: An O-ring (10) is provided at the connection between the bottom of the mounting groove (8) and the metal valve block (4).

5. The high-pressure inner liner of a plastic preform with a metal nozzle according to claim 1, 2, or 3, characterized in that: The inner cavity of the metal valve block (4) is provided with an internal thread (12).

6. The high-pressure inner liner of a plastic preform with a metal nozzle according to claim 1, 2, or 3, characterized in that: The thickness of the skirt (7) gradually decreases from the inside to the outside.

7. The high-pressure inner liner of the plastic preform with a metal nozzle according to claim 1, characterized in that: The locking block (3) and the flange (2) are an integrated structure.

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