Variable volume hydrogen storage cylinder liner injection mold and device

Abstract

This invention discloses a variable-volume injection mold and device for hydrogen storage cylinder liners. The mold includes a mold base and variable-volume structures. The mold base includes a fitted and matched female mold and a male mold. When the mold is closed, a cavity with the same shape as the liner is formed between the female mold and the male mold. Multiple variable-volume structures are provided, each with a shape consistent with the cavity and different thicknesses. The variable-volume structures can be detachably installed on the female mold and / or the male mold to change the cavity volume. By setting detachable variable-volume structures, this invention allows for flexible switching of variable-volume structures of different thicknesses or removal and installation of variable-volume structures to change the cavity volume, thereby controlling the thickness of the liner produced by injection molding. The mold has high adaptability, effectively saves mold opening costs, and improves production efficiency. This invention is applicable to the field of hydrogen storage cylinder liner manufacturing.

Description

Technical Field

[0001] This invention relates to the technical field of manufacturing hydrogen storage cylinder liners, specifically to an injection mold and device for a variable-volume hydrogen storage cylinder liner. Background Technology

[0002] Type IV hydrogen storage cylinders, with their core advantages of being lightweight and high-strength, resistant to high pressure and corrosion, and having a long driving range, have become key energy storage components in new energy vehicles, hydrogen fuel cell systems, and distributed hydrogen energy storage. The inner liner, serving as the pressure-bearing base and hydrogen barrier layer of the Type IV hydrogen storage cylinder, has dimensions that determine the amount of hydrogen it can hold, directly impacting its application scenarios. Its wall thickness design must be precisely matched based on working pressure, volume specifications, and material properties to meet the strength and safety requirements of relevant national standards. Currently, the mainstream molding process for the inner liner of small-to-medium volume Type IV hydrogen storage cylinders is injection molding. The core mold cavity is formed by the integrated machining of a fixed mold core and a moving mold core, creating a fixed gap. This gap is directly equivalent to the designed wall thickness of the inner liner, and the mold directly determines the volume of the inner liner.

[0003] However, in the existing technology, the mold size and the inner liner volume specifications are strictly matched. When the inner liner size needs to be adjusted to adapt to different application requirements, the fixed mold core, moving mold core and the matching gating system and cooling system must be redesigned, processed and assembled as a whole. This is equivalent to re-molding the entire mold. Re-molding leads to a longer production cycle, which cannot meet the market demand for rapid iteration and multi-specification small-batch production. At the same time, the cost of re-molding is high, which will significantly increase the company's production costs. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention provides a variable-volume injection mold and device for hydrogen storage cylinder liners, solving the problem of poor dimensional adaptability of existing injection molds leading to low production efficiency and increased production costs.

[0005] According to a first aspect of the present invention, a variable-volume hydrogen storage cylinder inner liner injection mold includes:

[0006] The mold base includes a female mold and a male mold that fit together. When the mold is closed, a closed cavity with the same shape as the inner liner is formed between the female mold and the male mold. The variable volume structure is provided in multiple ways. The shape of the multiple variable volume structures is the same as that of the cavity and they have different thicknesses. The variable volume structure can be detachably installed on one or both of the female mold and the male mold.

[0007] An injection mold for a variable-volume hydrogen storage cylinder liner according to an embodiment of the present invention has at least the following beneficial effects: This invention utilizes a detachable and installable variable volume structure to fill part of the gap between the female and male molds, thereby changing the thickness of the cavity and consequently altering the thickness of the inner liner obtained through the cavity. This adapts to different application requirements. This invention provides an injection mold capable of precisely adjusting the inner liner wall thickness. Simply replacing the variable volume structure can meet the production needs of inner liners of different sizes, eliminating the need for a complete redesign, processing, and assembly of the fixed mold core, moving mold core, and associated gating and cooling systems. This effectively improves production efficiency and saves mold development costs.

[0008] According to some embodiments of the present invention, the variable volume structure is a one-piece molded structure.

[0009] According to some embodiments of the present invention, the variable volume structure is provided with cooling water channels, which are arranged in a spiral manner around the axis of the variable volume structure.

[0010] According to some embodiments of the present invention, the variable volume structure includes a port segment, a transition segment, and a straight cylindrical segment. The port segment is a spherical structure, the straight cylindrical segment is a cylindrical structure, and the transition segment is smoothly connected between the port segment and the straight cylindrical segment. The port segment, the transition segment, and the straight cylindrical segment are sequentially and detachably connected.

[0011] According to some embodiments of the present invention, the two end faces connecting the port segment and the transition segment, and the transition segment and the straight cylinder segment are respectively provided with mutually matching snap-fit ​​structures, and the port segment, the transition segment and the straight cylinder segment are snap-fit ​​connected by the snap-fit ​​structures.

[0012] According to some embodiments of the present invention, the two end faces where the port segment and the transition segment meet, and the transition segment and the straight cylinder segment are provided with positioning mounting grooves and sealing rings.

[0013] According to some embodiments of the present invention, the variable volume structure is detachably fixed to the female mold and / or the male mold by bolts, wherein the bolts are interference fit.

[0014] According to some embodiments of the present invention, the variable volume structure is provided with grooves, which are uniformly distributed along the surface of the variable volume structure, and the grooves are used to form reinforcing ribs attached to the inner liner.

[0015] According to the present invention, a hydrogen storage cylinder inner liner injection molding device includes: The above-mentioned injection mold for the inner liner of a hydrogen storage cylinder; The casting module includes a barrel, an extruder, and a injection nozzle. The extruder is used to melt and pressurize the injection molding material injected into the barrel. The injection nozzle is connected to the cavity and is used to inject the melted and pressurized injection molding material into the cavity. The auxiliary module includes a moving platform, a track, and a robotic arm. The male mold and the female mold are slidably mounted on the track. The moving platform is used to move the male mold and the female mold closer and further apart along the track. The robotic arm is used to load and unload the variable volume structure and remove the inner liner.

[0016] According to some embodiments of the present invention, a detection module is further included, the detection module comprising a coaxiality detection mechanism and a position detection mechanism, the coaxiality detection mechanism being used to measure the coaxiality of the female mold and the male mold after the variable volume structure is assembled, and the position detection mechanism being used to test the distance between the male mold and the female mold along the track.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 A cross-sectional schematic diagram of an embodiment of a variable-volume hydrogen storage cylinder inner liner injection mold provided by the present invention. Figure 2 Cross-sectional schematic diagrams of two embodiments of a variable-volume hydrogen storage cylinder inner liner injection mold provided by the present invention. Figure 3 This is a schematic diagram of an embodiment of an injection molding device for a hydrogen storage cylinder liner provided by the present invention.

[0019] Icon labels: Mold base 100; Female mold 110; Male mold 120; Variable volume structure 200; port section 201; transition section 202; straight section 203; cooling water passage 210; snap-fit ​​structure 220; Casting module 300; barrel 310; extruder 320; injection nozzle 330; Auxiliary module 400; moving platform 410; track 420; robotic arm 430. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0021] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0022] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0023] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0025] Type IV hydrogen storage cylinders, with their core advantages of being lightweight and high-strength, resistant to high pressure and corrosion, and having a long driving range, have become key energy storage components in new energy vehicles, hydrogen fuel cell systems, and distributed hydrogen energy storage. The inner liner, serving as the pressure-bearing base and hydrogen barrier layer of the Type IV hydrogen storage cylinder, has dimensions that determine the amount of hydrogen it can hold, directly impacting its application scenarios. Its wall thickness design must be precisely matched to the working pressure, volume specifications, and material properties to meet the strength and safety requirements of relevant national standards. Currently, the mainstream molding process for the inner liner of small-to-medium volume Type IV hydrogen storage cylinders is injection molding. The core mold cavity is formed by the integrated machining of the fixed mold core and the moving mold core, creating a fixed gap. This gap is directly equivalent to the designed wall thickness of the inner liner, and the mold directly determines the inner liner's volume.

[0026] However, in the existing technology, the mold size and the inner liner volume specifications are strictly matched. When the inner liner size needs to be adjusted to adapt to different application requirements, the fixed mold core, moving mold core and the matching gating system and cooling system must be redesigned, processed and assembled as a whole. This is equivalent to re-molding the entire mold. Re-molding leads to a longer production cycle, which cannot meet the market demand for rapid iteration and multi-specification small-batch production. At the same time, the cost of re-molding is high, which will significantly increase the company's production costs.

[0027] Therefore, developing an injection mold that does not require overall mold opening, allows for precise adjustment of the inner liner size, and ensures molding accuracy is key to overcoming current technological bottlenecks and is of great significance for promoting the large-scale application of Type IV hydrogen storage cylinders.

[0028] To address the aforementioned problems, this invention proposes a variable-volume hydrogen storage cylinder inner liner injection mold and device, which can effectively solve the problems of poor size adaptability of existing injection molds leading to low production efficiency and increased production costs.

[0029] refer to Figure 1 , Figure 2 and Figure 3 This invention proposes a variable-volume injection mold and device for the inner liner of a hydrogen storage cylinder, with the following embodiments: Reference Figure 1 and Figure 2 An embodiment of the present invention provides a variable-volume injection mold for a hydrogen storage cylinder liner, comprising a mold base 100 and a variable-volume structure 200. The mold base 100 includes a fitted and matched female mold 110 and a male mold 120. When the mold is closed, a cavity with the same shape as the liner is formed between the female mold 110 and the male mold 120. Multiple variable-volume structures 200 are provided, and the shapes of the multiple variable-volume structures 200 are consistent with the cavity and have different thicknesses. The variable-volume structures 200 can be detachably installed on the female mold 110 and / or the male mold 120 to change the cavity volume.

[0030] The variable volume structure 200 can be set on either the female mold 110 assembly or the male mold 120 assembly, depending on the degree of change in the inner liner volume and thickness. Alternatively, it can be set on both the female mold 110 and the male mold 120. For easy demolding, it is generally set on the male mold 120. The specific situation can be adjusted according to the actual conditions. For example, when the volume change requirement is large, detachable modules can be installed on both the female mold 110 and the male mold 120.

[0031] This invention utilizes a detachable and installable variable volume structure 200 to fill part of the gap between the female mold 110 and the male mold 120, thereby changing the thickness of the cavity and consequently the thickness of the inner liner obtained through the cavity. This adapts to different application requirements. This invention provides an injection mold capable of precisely adjusting the inner liner wall thickness. Simply replacing the variable volume structure 200 can meet the production needs of inner liners of different sizes. There is no need to redesign, process, and assemble the fixed mold core, moving mold core, and the supporting gating and cooling systems, effectively improving production efficiency and saving mold development costs.

[0032] According to some embodiments of the present invention, for a variable volume structure 200 with a large thickness, the variable volume structure 200 is provided with a cooling water channel 210. Since the heat exchange efficiency of the variable volume structure 200 with a large thickness is slow and the melt cooling and molding rate is low, the independent cooling water channel 210 is designed to dissipate heat, accurately adjust the internal temperature of the mold, accelerate the molding speed, facilitate demolding, and improve production efficiency.

[0033] According to some embodiments of the present invention, the variable volume structure 200 is detachably fixed to the female mold 110 and / or the male mold 120 by bolts. The bolts are interference fit to ensure that the variable volume structure 200 is installed firmly and reliably, and to ensure that the radial runout of the variable volume structure 200 after assembly is less than 2%, thereby ensuring the overall accuracy and stability of the mold.

[0034] In some embodiments of the present invention, the variable volume structure 200 is provided with grooves, which are evenly distributed along the surface of the variable volume structure 200. The melt is cooled and formed in the grooves to form reinforcing ribs along the inner liner, thereby enhancing the strength and rigidity of the inner liner and preventing tearing during demolding. This is particularly suitable for cases where the inner liner thickness is small and the variable volume structure 200 thickness is large. Preferably, the variable volume structure 200 is detachably installed on the male mold 120, so that the cavity surface where the groove is located corresponds to the inner surface of the inner liner, thereby setting the generated reinforcing ribs inside the inner liner to reduce the surface treatment process of the inner liner.

[0035] The following is a specific embodiment of the variable volume structure 200 in a variable volume hydrogen storage cylinder inner liner injection mold: Example 1 Reference Figure 1 As shown, the injection mold of this embodiment includes a mold base 100 and a variable volume structure 200. The mold base 100 includes a female mold 110 and a male mold 120 that fit together. When the mold is closed, a closed cavity with the shape of the inner liner is formed between the female mold 110 and the male mold 120. The variable volume structure 200 adopts an integrated design and is a one-piece molding structure. The variable volume structure 200 is provided with a cooling water channel 210, which is spirally arranged around the axis of the variable volume structure 200.

[0036] The integrated variable volume structure 200 forms a unified whole, ensuring the sealing of the injection molding process, making it difficult for the melt to enter the gaps, and reducing the need for subsequent processing of the molded inner liner.

[0037] A cooling water channel 210 is provided as a cooling structure to help the variable volume structure 200 dissipate heat independently. The cooling water channel 210 has an inlet and an outlet, and the inlet and outlet are equipped with quick connectors. It is located at the bottom of the variable volume structure 200 and other positions that do not interfere with other functions. The cooling water channel 210 is arranged in a spiral around the axis of the variable volume structure 200 to achieve uniform heat dissipation and avoid the problem of inner tank deformation caused by uneven cooling. This is beneficial to improving the quality of the inner tank output. In some other embodiments, the cooling water channel 210 can be adjusted and optimized according to heat dissipation requirements.

[0038] Example 2 Reference Figure 2As shown, the injection mold in this embodiment includes a mold base 100 and a variable volume structure 200. The mold base 100 includes a female mold 110 and a male mold 120 that fit together. When the mold is closed, a closed cavity with the same shape as the inner liner is formed between the female mold 110 and the male mold 120. The variable volume structure 200 adopts a modular design, including a port section 201, a transition section 202, and a straight section 203. The port section 201 is a spherical structure, and the straight section 203 is a cylindrical structure. The transition section 202 is smoothly connected between the port section 201 and the straight section 203, ensuring both strength and smooth shape to prevent stress concentration during use and damage. The port section 201, the transition section 202, and the straight section 203 are detachably connected in sequence. By designing the variable volume structure 200 as a structure with several detachable sections, the variable volume structure 200 can be disassembled, making it easy to flexibly replace one of the detachable sections, facilitating disassembly, cleaning, and maintenance, and helping to reduce maintenance costs.

[0039] For the modularly designed variable volume structure 200, if a cooling water channel 210 is required, its sealing performance should be specially reinforced to prevent cooling failure.

[0040] Among them, the two end faces connecting the port segment 201 and the transition segment 202, and the transition segment 202 and the straight cylinder segment 203 are respectively provided with matching snap-fit ​​structures 220. The port segment 201, the transition segment 202 and the straight cylinder segment 203 are snap-fit ​​connected by the snap-fit ​​structures 220 to form a reliable detachable connection to ensure the injection molding accuracy and prevent defects such as coaxiality error of the inner liner caused by misalignment of the port segment 201, the transition segment 202 and the straight cylinder segment 203 in the variable volume structure 200.

[0041] Furthermore, positioning mounting grooves and sealing rings are provided on the two end faces where the port section 201 and the transition section 202, and the transition section 202 and the straight section 203 meet. The positioning mounting grooves serve as guides to facilitate splicing and installation, and also ensure the precise positioning of the components of the port section 201, the transition section 202, and the straight section 203, ensuring a tight fit between the parts and reducing the possibility of melt leakage due to gaps. At the same time, the sealing rings ensure the sealing performance during the injection molding process, further ensuring the smoothness of the cavity surface and preventing melt leakage. The material of the sealing ring is selected according to the material processing technology and processing temperature. In this embodiment, a high-temperature resistant fluororubber sealing ring is used.

[0042] The design method for the variable volume structure 200 specifically includes the following steps: Difference analysis and strength verification are conducted to clarify the specifications of the product formed by the existing mold and the specifications of the target inner liner, focusing on calculating the differences between the two in terms of volume, working pressure and material parameters. Based on this, finite element simulation software (such as ANSYS) is used to verify the strength of the target inner liner, determine whether the specifications of the target inner liner meet the strength requirements, and determine whether reinforcing ribs need to be added.

[0043] Cavity conversion and initial module size determination: The shape of the mold cavity corresponding to the target inner liner is calculated by finite element simulation software. Boolean subtraction operation is performed between this target cavity contour and the existing mold cavity contour to obtain the initial variable volume structure size of 200.

[0044] The modular structure design, based on the initial variable volume structure size 200 and considering its functional and material requirements, determines whether to adopt an integral or modular design. During the design process, it is essential to ensure that the module's heat transfer performance is no less than that of the original mold. If the module thickness variation exceeds 30% of the original thickness, it is recommended to integrate an independent cooling channel. The module structure requires refined design, with particular attention to the morphology of the port section 201, transition section 202, and straight section 203, ensuring reliable connection with the original mold and completing the cooling channel layout design. This process requires necessary design iterations and modifications.

[0045] After the variable volume structure 200 is manufactured, it must be precisely installed into the original mold, ensuring accurate alignment and a secure connection.

[0046] Reference Figure 3 As shown, the present invention also provides a hydrogen storage cylinder liner injection molding device, specifically including the above-mentioned variable volume hydrogen storage cylinder liner injection mold, casting module and auxiliary module 400.

[0047] The casting module 300 includes a barrel 310, an extruder 320, and a nozzle 330. The extruder 320 is used to melt and pressurize the injection material injected into the barrel 310. The nozzle 330 is connected to the cavity and is used to inject the melted and pressurized injection material into the cavity. The auxiliary module 400 includes a moving platform 410, a track 420, and a robot arm 430. The male mold 120 and the female mold 110 are slidably mounted on the track 420. The moving platform 410 is used to drive the male mold 120 and the female mold 110 to move closer and further away from each other along the track 420. The robot arm 430 is used to load and unload the variable volume structure 200 and remove the inner liner.

[0048] A method for using a hydrogen storage cylinder inner liner injection molding device includes the following steps: The variable volume structure 200 is installed on the female mold 110 and / or male mold 120 using a robotic arm 430. The moving table 410 moves the male mold 120 closer to the female mold 110 until a closed cavity is formed and locked. Polymer granules flow into the extruder 320 through the barrel 310. In the extruder 320, the granules are melted, plasticized and pressurized at high temperature. They are then injected into the cavity formed by the female mold 110, male mold 120 and variable volume structure 200 through the injection nozzle 330 until the cavity is filled and the required pressure is reached. The extruder 320 then stops injecting the molten material and cools and hardens it. Subsequently, the moving table 410 moves the male mold 120 on the track 420 away from the female mold 110 along the guide rail to perform the mold opening action. The robotic arm 430 then removes the cooled inner liner. The above steps are repeated to achieve mass production of hydrogen storage cylinder inner liners.

[0049] According to some embodiments of the present invention, a detection module is also included. The detection module includes a coaxiality detection mechanism and a position detection mechanism. The coaxiality detection mechanism is used to measure the coaxiality of the female mold 110 and the male mold 120 after assembling the variable volume structure 200. The position detection mechanism is used to test the distance between the male mold 120 and the female mold 110 along the track 420. The coaxiality detection mechanism includes a laser displacement sensor. The laser displacement sensor is used to test the coaxiality of the mold under different volume specifications. Based on the feedback, a small correction is made to control the coaxiality error of the gas cylinder liner of the same volume specification within the design accuracy range. The position detection mechanism is used to detect the distance between the male mold 120 and the female mold 110 along the track 420 and feed it back to the moving stage 410 to ensure that the gap between the two molds is within the error range, ensuring the formation of a closed cavity. At the same time, the female mold 110 and the male mold 120 will not collide due to excessive movement, thereby damaging the mold base 100 and affecting the production accuracy of the liner.

[0050] The present invention provides a variable-volume injection mold and device for hydrogen storage cylinder liners, which enables rapid adjustment of the liner volume through modular component replacement without requiring a complete mold replacement. This reduces the switching time for cylinder liner volume specifications to less than 3 hours and lowers mold development costs by more than 80%. It ensures that the coaxiality error of cylinder liners with different volume specifications is ≤±0.02mm, and the volume tolerance is controlled within 5%. The adjustment range covers commonly used volume ranges below the original volume, adapting to mainstream liner specifications under working pressures of 35MPa-70MPa. This results in a compact, convenient, and stable adjustable-volume injection mold, enabling mass production of hydrogen storage cylinder liners with different thickness requirements.

[0051] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0052] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0053] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A variable-volume injection mold for a hydrogen storage cylinder liner, characterized in that, include: The mold base includes a female mold and a male mold that fit together. When the mold is closed, a closed cavity with the same shape as the inner liner is formed between the female mold and the male mold. The variable volume structure is provided in multiple ways. The shape of the multiple variable volume structures is the same as that of the cavity and they have different thicknesses. The variable volume structure can be detachably installed on the female mold and / or the male mold.

2. The injection mold for the inner liner of a hydrogen storage cylinder according to claim 1, characterized in that: The variable volume structure is a one-piece molded structure.

3. The injection mold for the inner liner of a hydrogen storage cylinder according to claim 2, characterized in that: The variable volume structure is provided with cooling water channels, which are arranged in a spiral pattern around the axis of the variable volume structure.

4. The injection mold for the inner liner of a hydrogen storage cylinder according to claim 1, characterized in that: The variable volume structure includes a port segment, a transition segment, and a straight cylindrical segment. The port segment is a spherical structure, the straight cylindrical segment is a cylindrical structure, and the transition segment is smoothly connected between the port segment and the straight cylindrical segment. The port segment, the transition segment, and the straight cylindrical segment are detachably connected in sequence.

5. The injection mold for the inner liner of a hydrogen storage cylinder according to claim 4, characterized in that: The two end faces connecting the port segment and the transition segment, and the transition segment and the straight cylinder segment, are respectively provided with mutually matching snap-fit ​​structures, and the port segment, the transition segment and the straight cylinder segment are snap-fit ​​connected through the snap-fit ​​structures.

6. The injection mold for the inner liner of a hydrogen storage cylinder according to claim 4, characterized in that: The two end faces connecting the port segment and the transition segment, and the transition segment and the straight cylinder segment, are provided with positioning mounting grooves and sealing rings.

7. The injection mold for the inner liner of a hydrogen storage cylinder according to claim 1, characterized in that: The variable volume structure is detachably fixed to the female mold and / or the male mold by bolts, and the bolts are interference fit.

8. The injection mold for the inner liner of a hydrogen storage cylinder according to claim 1, characterized in that: The variable volume structure is provided with grooves, which are evenly distributed along the surface of the variable volume structure, and the grooves are used to form reinforcing ribs attached to the inner liner.

9. A hydrogen storage cylinder inner liner injection molding device, characterized in that, include: The injection mold for the inner liner of a hydrogen storage cylinder as described in any one of claims 1 to 8; The casting module includes a barrel, an extruder, and a injection nozzle. The extruder is used to melt and pressurize the injection molding material injected into the barrel. The injection nozzle is connected to the cavity and is used to inject the melted and pressurized injection molding material into the cavity. The auxiliary module includes a moving platform, a track, and a robotic arm. The male mold and the female mold are slidably mounted on the track. The moving platform is used to move the male mold and the female mold closer and further apart along the track. The robotic arm is used to load and unload the variable volume structure and remove the inner liner.

10. The injection molding device for the inner liner of a hydrogen storage cylinder according to claim 9, characterized in that: It also includes a detection module, which includes a coaxiality detection mechanism and a position detection mechanism. The coaxiality detection mechanism is used to measure the coaxiality of the female mold and the male mold after the variable volume structure is assembled, and the position detection mechanism is used to test the distance between the male mold and the female mold along the track.

Images