Manufacturing mold and manufacturing process of IV-type hydrogen storage tank

Abstract

The manufacturing mold comprises a mold body and a transmission mechanism installed below the mold body, the mold body comprises a left mold base and a right mold base which are symmetrically arranged, and each of the left mold base and the right mold base comprises an inner container female mold with the middle being a smooth curved surface and bottle opening female molds arranged at the two ends of the inner container female mold; excess material female dies communicating with the outer sides of the dies are arranged at the two ends of the left die base and the two ends of the right die base correspondingly, a vertical stop groove and a transverse stop groove are formed in the outer side of the vertical limiting part, and a transverse stop groove is formed in the edge of the cambered surface limiting part. The metal lining part is fixed to the designated position through the fixed mounting rod, in the blow molding process, the metal lining part is fixed to the position of a liner bottle opening, the liner bottle opening in the molten state is embedded into the vertical stop groove and the transverse stop groove through extrusion during mold closing, stable mounting of the metal lining part is achieved, and meanwhile the metal lining part is fixed to the designated position through the fixed mounting rod. The sealing performance of the metal lining piece and the bottle opening of the inner container can be ensured; and compared with rotational molding and injection molding modes, the reliability is higher.

Description

Technical Field

[0001] The invention relates to a manufacturing mold and a manufacturing process of an IV type hydrogen gas storage tank, belonging to the technical field of gas storage device processing. Background Art

[0002] Hydrogen storage technology is the key to the development of new energy vehicles. The development and application technology of traditional metal-lined Type III gas cylinders is becoming increasingly mature in my country. However, this type of gas cylinder has obvious disadvantages such as hydrogen embrittlement effect and poor fatigue performance, which poses a huge obstacle when used as a vehicle-mounted hydrogen storage cylinder. The plastic-lined Type IV gas cylinders that have gradually developed in recent years provide a feasible idea for improving the hydrogen density, fatigue performance and hydrogen barrier performance of vehicle-mounted gas cylinders. In order to improve the overall stiffness, metal bottle mouth technology is usually used at both ends of the plastic liner of the Type IV gas cylinder to meet the problem of liner fixation in the subsequent winding process. Due to the obvious difference in the materials of the metal bottle mouth and the plastic liner, the interface connection quality between the two becomes the key to determining the airtightness of the gas cylinder. In addition, the plastic head of the gas cylinder will undergo a slight deformation during the filling and deflation process, resulting in a gap between it and the metal bottle mouth, which is prone to hydrogen leakage and other problems, posing a major safety hazard.

[0003] The existing Chinese patent CN 118254319 A discloses a method for roto-molding a type IV bottle including a valve seat. The application discloses a technical solution including "step S1: installing the valve seat in the roto-molding mold head of the roto-molding equipment; step S2: adding raw materials into the roto-molding mold of the roto-molding equipment, keeping the mold horizontal and turning on the vacuum equipment for vacuuming; step S3: turning on the mold heating and mold rotation; step S4: after the heating is completed, cooling the mold and introducing protective gas for demoulding; the mold heating is divided into three stages of heating, including: the first stage of heating: the mold temperature is 100°C to 140°C, the valve seat additional compensation temperature is 100°C to 140°C, and the heating time is 15 to 30 minutes; the second stage Heating: mold temperature is 160℃ to 200℃, valve seat additional compensation temperature is 40℃ to 80℃, heating time is 10 to 30 minutes; third stage heating: mold temperature is 230℃ to 260℃, heating time is 5 to 15 minutes. "According to the process disclosed in the application, it can be seen that the minimum heating stage of IV type hydrogen storage tank by rotational molding is 30 minutes and the maximum is 75 minutes. Although the rotational molding cradle can simultaneously install multiple rotational molding molds for rotational processing, this is only the heating time and demoulding cooling time, which still takes a lot of production time. The rotational molding process takes a long time, which is not conducive to the rapid mass production of products. There is also CN 114889038 A, a device and method for injection molding the liner of a type IV gas cylinder. The application discloses a technical solution: "The metal head 8 includes a head section and an elliptical shoulder, the head section is provided with a thread 81, the upper side of the elliptical shoulder has a barb-shaped groove 82, the lower side of the shoulder has a trapezoidal step groove 83, and the elliptical shoulder is anodized or acid-treated and ultrasonically cleaned with water before injection molding to form a nano-scale microporous structure. During the implementation, the molten polymer enters the nano-scale micropores to produce an "anchor connection", the bonding area is increased, and the bonding strength between the metal shoulder and the plastic is improved." This application is an injection molding method, and the mold structure design is complex. In the structural design of the metal shoulder, since the plastic is wrapped outside the metal shoulder, The surface is sealed by strengthening the contact area between the plastic and the metal. "The elliptical shoulder is anodized or acid-treated and ultrasonically cleaned with water before injection molding to form a nano-scale microporous structure." The metal shoulder needs to be pre-processed, and the consistency of this pre-processing cannot be guaranteed, that is, the contact tightness between the plastic and the metal shoulder cannot be actually guaranteed. In addition, the exhaust channel 12 of this application is arranged in the bottle body structure part, which is far away from the metal shoulder. The gas in the nano-scale micropores is very likely to remain in the gap during the injection molding process. When the molten plastic is filled into the metal shoulder, the probability of causing a cavity is relatively increased, which is further reflected in that the fit between the plastic and the metal shoulder will be affected.

[0004] Therefore, in view of the shortcomings of the existing technology, there is an urgent need for a mold and a manufacturing process for a type IV hydrogen storage tank with fast production speed and better connection stability and reliability between the metal liner and the plastic liner. Summary of the invention

[0005] Purpose of the invention: In view of the deficiencies in the prior art, the present invention provides a mold and a manufacturing process for a type IV hydrogen storage tank, wherein a metal lining is fixed at a specified position by a fixed mounting rod, and during the blow molding process, the metal lining is fixed at the mouth of the inner liner bottle, and the mouth of the inner liner bottle in a molten state is embedded in the vertical stop groove and the horizontal stop groove through extrusion when the mold is closed, so that the stable installation of the metal lining is achieved, and the sealing between the metal lining and the mouth of the inner liner bottle can be ensured, so as to solve the problems mentioned in the above-mentioned background technology.

[0006] Technical solution: A mold for making a type IV hydrogen gas storage tank, comprising a mold and a transmission mechanism installed under the mold, characterized in that: the mold comprises a symmetrically arranged left mold base and a right mold base, the left mold base and the right mold base move inward or outward at the same time through a transmission mechanism arranged under the mold, and further comprises a fixed mounting rod whose lower end is fixedly connected to the transmission mechanism, the two ends of the fixed mounting rod are respectively provided with metal lining parts, the fixed mounting rod is arranged as a hollow structure with a hole on the side, and is connected to the air blowing pipeline; The left mold base and the right mold base both include an inner liner die with a smooth curved surface in the middle and bottle mouth dies arranged at both ends of the inner liner die. Both ends of the left mold base and the right mold base are provided with residual material dies connected to the outside of the mold. The inner wall of the inner liner die is provided with fine air holes connected to the outside of the mold. The metal lining part includes a vertical limiting part set in the gap with the bottle mouth die and an arc surface limiting part set in the gap with the inner liner die. A vertical stop groove and a transverse stop groove are set on the outer side of the vertical limiting part, and a transverse stop groove is set on the edge of the arc surface limiting part.

[0007] The present invention fixes the metal lining component at a specified position by fixing the installation rod. During the blow molding process, the metal lining component is fixed at the mouth of the inner liner bottle. The mouth of the inner liner bottle in a molten state is embedded in the vertical stop groove and the horizontal stop groove through extrusion when the mold is closed, so that the stable installation of the metal lining component can be achieved while ensuring the sealing between the metal lining component and the mouth of the inner liner bottle. Compared with rotational molding and injection molding, the reliability is higher. During the blow molding process, air is discharged through fine pores without affecting the surface state of the molded inner liner, thereby improving the smoothness of demoulding. The residual material concave molds arranged at both ends of the left mold base and the right mold base can retain excess plastic in the residual material concave mold when the mold is closed, and the flow of plastic can be restricted by extrusion during mold closing to prevent residual material from adhering to the upper side of the mold, making it more convenient to clean the residual material.

[0008] A truncated boss is provided at the connection between the upper end of the bottle mouth die and the residual material die. After the mold is closed, the truncated bosses on the left and right die bases abut against the fixed mounting rod, and the truncated bosses on both sides are combined to form a closed circular truncated surface.

[0009] By setting a truncation boss, during the mold closing process, the molten plastic is gradually gathered to the fixed installation rod, so that the plastic can gradually adhere to the surface of the metal lining component. When the mold is closed, the truncation boss abuts against the fixed installation rod to cut off the molten plastic. At this time, the liner die and the bottle mouth die exert inward extrusion on the molten plastic to fill the material completely. At the same time, the gap between the metal liner and the liner die and the bottle mouth die constitutes a partial shoulder and a complete bottle mouth structure of the gas tank. The bottle body and the remaining shoulder structure are expanded and fit with the liner die through the blow molding process, and solidify after cooling to form a complete liner structure.

[0010] The fixed mounting rod comprises a connecting rod and connecting sleeves provided at both ends of the connecting rod and provided with external threads, the metal lining is threadedly connected to the connecting sleeve, and after the mold is closed, the truncated boss abuts against the outer side surface of the connecting sleeve; The connecting rod includes an upper connecting rod and a lower connecting rod. Any one of the upper connecting rod and the lower connecting rod is provided with a plug-in groove at the end away from the connecting sleeve, and the other end close to the plug-in groove is provided with a plug-in key matching the plug-in groove. The upper end of the connecting sleeve at the end of the upper connecting rod is provided with a process groove for cooperating with a rotating tool.

[0011] For double-bottle-mouth gas storage tanks, in order to facilitate the disassembly work after demolding, the fixed mounting frame is set as an upper and lower split structure, and the contact embedding connection method is adopted to realize quick installation and disassembly. The connecting sleeve is used at the end to install the metal lining part, which is convenient for fixing the metal lining part, and can reduce the diameter of the upper connecting rod and the lower connecting rod, so as to further improve the convenience of installation and disassembly. Even if the upper connecting rod is slightly offset in the case of certain wear and tear due to long-term use, the inward extrusion of the fixed connecting rod by the truncated boss before the mold is fully closed can realize the automatic correction function during the mold closing process; by setting the process groove, after the subsequent demolding is completed, it is more convenient to use tools to unscrew the fixed mounting rod when taking it out.

[0012] Both ends of the left mold base and the right mold base are located on the left and right sides of the bottle mouth die, the residual material die and the inner liner die shoulder part, and sunken flash material cutting areas are provided. The edges of the bottle mouth die, the residual material die and the inner liner die shoulder part are in the same plane as the edge of the inner liner die body part.

[0013] In order to avoid excess material that does not enter the residual material cavity during the mold closing process, a sunken flash material cut-off area is set. When the molten plastic is cut off during mold closing, more excess material can enter the flash material cut-off area to avoid the situation where the mold cannot be completely closed during mold pressing. The edge parts of other structures are kept in the same plane to ensure that no material is squeezed out of the mold during mold closing, making the product surface smoother and improving product quality.

[0014] A positioning wedge groove is provided at the edge of the flash material cutting zone, a positioning wedge block is fixedly arranged in any positioning wedge groove, the shape of the other positioning wedge groove matches the shape of the positioning wedge block, and the positioning wedge block is embedded in the other positioning wedge groove after mold closing.

[0015] In order to avoid the possible up and down displacement of the mold after mold closing, the positioning wedge block and the positioning wedge groove are coordinated to achieve self-guiding during the mold closing process and auxiliary positioning after the mold closing is completed, thereby ensuring the mold closing stability of the left mold base and the right mold base.

[0016] The left mold base and the right mold base are provided with cooling water pipes inside, any of the cooling water pipes penetrates the mold and is connected to the external water channel, and the cooling water pipes are provided with at least two layers along the thickness direction of the mold, and the number of cooling water pipes increases from the outside to the inside; Exhaust pipelines are also provided inside the left mold base and the right mold base. Any of the exhaust pipelines is connected to fine air holes and is connected to the outside of the mold through the exhaust pipeline. The aperture size of the fine air holes is 02.mm~0.4mm.

[0017] In order to lower the mold temperature and quickly exchange heat to solidify the molten plastic, a cooling water channel is arranged inside the mold in a crisscross pattern. The water channels close to the inner liner cavity are more densely distributed to improve the heat exchange efficiency. The rest are used as auxiliary cooling for the mold. The number is relatively small, which saves mold opening costs and ensures that the cooling effect meets the requirements of cooling and solidification. The aperture size of the fine pores is limited within a certain range, which can not only achieve exhaust but also avoid plastic entering the fine pores under the action of air pressure to cause blockage or an uneven product surface.

[0018] The transmission mechanism comprises a gear base which is transmission-connected to the driving device and is fixed in position, the middle of the gear base is fixedly connected to the connecting sleeve of the lower connecting rod, and driving gears are respectively arranged near the middle of both ends, and the driving gears are transmission-connected to the output end of the driving device; It also includes two rack transmission assemblies corresponding to the driving gears at both ends, any of the rack transmission assemblies includes a first spur rack and a second spur rack that are relatively arranged on both sides of the driving gear and mesh with the driving gear, one end of the first spur rack is fixedly connected to the left mold base through a first fixing rod, and the opposite end of the second spur rack is fixedly connected to the right mold base through a second fixing rod; The two ends of the gear base are provided with guide holes, and guide shafts are installed in the guide holes. The guide shafts are located on both sides of the gear base and are respectively provided with guide rods fixedly connected with the left mold base and the right mold base.

[0019] The double gear transmission at the bottom ensures that the mold remains synchronized during the movement process. The setting of the guide structure ensures the consistency of direction during the movement of the mold, making the mold closing action more precise and further improving the production quality of the product.

[0020] The manufacturing process of the mold for making a type IV hydrogen gas storage tank includes the following steps: Step 1: Unloading and mold closing The cylindrical molten plastic liner raw material is squeezed downward by a discharge device arranged just above the fixed installation rod, so that the fixed installation rod is inserted into the hollow part of the cylindrical plastic liner raw material until the lower end of the plastic liner raw material completely covers the connecting sleeve of the lower connecting rod, and the transmission mechanism is started to move the left mold base and the right mold base closer to the inside until the left mold base contacts the right mold base, and the positioning wedge is embedded in the positioning wedge groove; Step 2: Blow molding After the mold is closed, the gas flows through the fixed mounting rod through the air blowing pipeline and is filled into the mold. The molten plastic liner raw material is filled with gas until it fits the inner wall of the liner cavity mold. After being cooled by the left and right mold bases, it is cooled and solidified. Step 3: Edge grinding After the cooling and solidification stage, the mold is opened to take out the solidified type IV hydrogen gas storage tank, and the excess plastic produced by the side seam extrusion during the mold closing process is trimmed and polished to make the surface roughness of the type IV hydrogen gas storage tank less than or equal to 1.6 microns.

[0021] During the mold closing process of step 1, when the left mold base and the right mold base are squeezed with the plastic liner raw material, inward pressure is generated, so that the plastic liner raw material gradually adheres to the surface of the metal lining part as the left mold base and the right mold base move until the mold closing is completed. The molten plastic liner raw material is squeezed through the mold and filled into the vertical stop groove and the horizontal stop groove.

[0022] The gas pressure of the gas introduced into the mold in step 2 is 0.6 MPa to 0.8 MPa; The left mold base and the right mold base are kept at a temperature of 28°C to 32°C by controlling the flow rate of the cooling water pipe; After the mold is closed, the cooling and solidification are completed within 3 minutes, and the mold is opened to proceed to step 3.

[0023] Beneficial effects: The present invention fixes the metal lining component at a specified position by means of a fixed mounting rod. During the blow molding process, the metal lining component is fixed at the mouth of the inner liner bottle. The mouth of the inner liner bottle in a molten state is embedded in the vertical stop groove and the horizontal stop groove through extrusion during mold closing. This ensures stable installation of the metal lining component while ensuring the sealing between the metal lining component and the mouth of the inner liner bottle. Compared with rotational molding and injection molding, the reliability is higher. By setting a cut-off boss, during the mold closing process, the molten plastic is gradually gathered toward the fixed mounting rod, so that the plastic can gradually adhere to the surface of the metal lining component. When the mold is closed, the cut-off boss abuts against the fixed mounting rod to cut off the molten plastic. At this time, the inner liner cavity mold and the bottle mouth cavity mold exert inward extrusion on the molten plastic to fill the material completely. When the blow molding is completed, the sealing of the bottle mouth part is also completed, so that the IV type hydrogen storage tank liner structure with reliable sealing stability can be quickly produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the overall structure of the mold of the present invention.

[0026] Figure 2 It is a schematic diagram of the right mold base structure of the present invention.

[0027] Figure 3 It is a partial schematic diagram of the installation structure of the right mold base and the metal lining component of the present invention.

[0028] Figure 4 It is a partial schematic diagram of the right mold base of the present invention.

[0029] Figure 5 This is a schematic diagram of the structure in which the metal lining component of the present invention is installed on the connecting sleeve.

[0030] Figure 6 This is a schematic diagram of the structure in which the fixed mounting rod of the present invention is installed on the gear base.

[0031] Figure 7 This is a cross-sectional view of the connection between the upper connecting rod and the lower connecting rod of the present invention.

[0032] Figure 8 This is a top view of the fixed mounting rod of the present invention installed on the gear base structure.

[0033] Fig. 9 It is a schematic diagram of the layout of the cooling water pipe and the exhaust pipe of the present invention.

[0034] Fig.10 It is a partial diagram of the transmission mechanism of the present invention.

[0035] Fig.11 It is a partial diagram of the transmission mechanism of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0038] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] like Figures 1 to 4 As shown, a mold for making a type IV hydrogen gas storage tank includes a mold and a transmission mechanism 3 installed under the mold, the mold includes a left mold base 1 and a right mold base 2 symmetrically arranged, the left mold base 1 and the right mold base 2 are simultaneously moved inward or outward through the transmission mechanism 3 arranged under the mold, and also includes a fixed installation rod 4 whose lower end is fixedly connected to the transmission mechanism 3, and both ends of the fixed installation rod 4 are respectively provided with metal lining parts 41, and the fixed installation rod 4 is set as a hollow structure with a hole on the side, which is connected to the blowing pipeline; The left mold base 1 and the right mold base 2 each include an inner liner die 5 with a smooth curved surface in the middle and bottle mouth dies 6 arranged at both ends of the inner liner die 5. Both ends of the left mold base 1 and the right mold base 2 are provided with residual material dies 7 connected to the outside of the mold. The inner wall of the inner liner die 5 is provided with fine air holes 8 connected to the outside of the mold. The metal lining 41 includes a vertical limiting portion 411 provided with a gap between the bottle mouth die 6 and a curved limiting portion 412 provided with a gap between the inner liner die 5. A vertical stop groove 413 and a horizontal stop groove 414 are provided on the outer side of the vertical limiting portion 411, and a horizontal stop groove 414 is provided on the edge of the curved limiting portion 412. The curved surface of the curved limiting portion 412 can also be provided with an annular groove and a vertical groove that are the same as those of the vertical limiting portion 411 to achieve vertical and horizontal stops.

[0040] The present invention fixes the metal lining component 41 at a specified position by fixing the mounting rod 4. During the blow molding process, the metal lining component 41 is fixed at the mouth of the inner liner bottle. The mouth of the inner liner bottle in a molten state is embedded in the vertical stop groove 413 and the horizontal stop groove 414 through the extrusion when the mold is closed. While achieving stable installation of the metal lining component 41, the sealing between the metal lining component 41 and the mouth of the inner liner bottle can be ensured; compared with rotational molding and injection molding, the reliability is higher; during the blow molding process, the air is discharged through the fine air holes 8 without affecting the surface state of the molded inner liner, thereby improving the smoothness of demoulding; the residual material die 7 arranged at both ends of the left mold base 1 and the right mold base 2 can retain the excess plastic in the residual material die 7 when the mold is closed, and the extrusion of the mold closing can limit the flow of plastic to prevent the residual material from adhering to the upper side of the mold, making it more convenient to clean the residual material.

[0041] A truncated boss 9 is provided at the connection between the upper end of the bottle mouth die 6 and the residual material die 7. After the mold is closed, the truncated boss 9 on the left mold base 1 and the right mold base 2 abuts against the fixed mounting rod 4, and the truncated bosses 9 on both sides are combined to form a closed circular truncated surface.

[0042] By setting the truncation boss 9, during the mold closing process, the molten plastic is gradually gathered to the fixed mounting rod 4, so that the plastic can gradually adhere to the surface of the metal lining component 41. When the mold is closed, the truncation boss 9 abuts against the fixed mounting rod 4 to cut off the molten plastic. At this time, the liner die 5 and the bottle mouth die 6 apply inward extrusion to the molten plastic to fill the material completely. At the same time, the gap between the metal lining component 41 and the liner die 5 and the bottle mouth die 6 constitutes a partial shoulder and a complete bottle mouth structure of the gas tank. The bottle body and the remaining shoulder structure are expanded and fit with the liner die 5 through the blow molding process, and solidify after cooling to form a complete liner structure.

[0043] like Figures 5 to 8 As shown, the fixed installation rod 4 includes a connecting rod and connecting sleeves 42 provided at both ends of the connecting rod and provided with external threads, the metal lining 41 is threadedly connected to the connecting sleeve 42, and after the mold is closed, the truncated boss 9 abuts against the outer side surface of the connecting sleeve 42; The connecting rod includes an upper connecting rod 43 and a lower connecting rod 44. Any one of the upper connecting rod 43 and the lower connecting rod 44 is provided with a plug-in groove 45 at the end away from the connecting sleeve 42, and the other end close to the plug-in groove 45 is provided with a plug-in key 46 matching the plug-in groove 45. The upper end of the connecting sleeve 42 at the end of the upper connecting rod 43 is provided with a process groove 47 for cooperating with a rotating tool.

[0044] For the double-bottle-mouth gas storage tank, in order to facilitate the disassembly work after demolding, the fixed mounting frame is set as an upper and lower split structure, and a contact embedding connection method is adopted to realize quick installation and disassembly. The end is connected with a connecting sleeve 42 for installing the metal lining 41, which is convenient for fixing the metal lining 41, and can reduce the diameter of the upper connecting rod 43 and the lower connecting rod 44, so as to further improve the convenience of installation and disassembly. Even if the upper connecting rod is slightly offset due to certain wear and tear caused by long-term use, the inward extrusion of the fixed connecting rod by the truncated boss 9 before the mold is fully closed can realize the automatic correction function during the mold closing process; by setting the process groove 47, after the subsequent demolding is completed, it is more convenient to use tools to unscrew the fixed mounting rod 4 when taking it out.

[0045] Both ends of the left mold base 1 and the right mold base 2 are located on the left and right sides of the bottle mouth die 6, the residual material die 7 and the shoulder part of the liner die 5, and sunken flash material cutting areas 10 are provided. The edges of the bottle mouth die 6, the residual material die 7 and the shoulder part of the liner die 5 are in the same plane as the edge of the bottle body part of the liner die 5.

[0046] In order to avoid excess residue that fails to enter the residue cavity 7 during the mold closing process, a sunken flash material cutting-off area 10 is provided. When the molten plastic is cut off during the mold closing, more residue can enter the flash material cutting-off area 10, thereby avoiding the situation that the mold cannot be completely closed during pressing. The edge parts of other structures are kept in the same plane to ensure that no material is squeezed out of the mold during the mold closing, so that the product surface is smoother and the product quality is improved.

[0047] The edge of the flash material cutting area 10 is provided with a positioning wedge groove 101, and a positioning wedge block 102 is fixedly arranged in any positioning wedge groove 101. The shape of the other positioning wedge groove 101 matches the shape of the positioning wedge block 102. After the mold is closed, the positioning wedge block 102 is embedded in the other positioning wedge groove 101.

[0048] In order to avoid the possible upward and downward displacement of the mold after mold closing, the positioning wedge block 102 and the positioning wedge groove 101 cooperate to achieve self-guiding during the mold closing process and auxiliary positioning after the mold closing is completed, thereby ensuring the mold closing stability of the left mold base 1 and the right mold base 2.

[0049] like Fig. 9 As shown, the left mold base 1 and the right mold base 2 are provided with cooling water pipes 103 inside, and any cooling water pipe 103 passes through the mold and is connected to the external water channel. The cooling water pipes 103 are provided with at least two layers along the thickness direction of the mold, and the number of cooling water pipes 103 increases from the outside to the inside; Exhaust pipelines are also provided inside the left mold base 1 and the right mold base 2. Any of the exhaust pipelines 104 is connected to the fine air holes 8 and is connected to the outside of the mold through the exhaust pipeline 104. The aperture size of the fine air holes 8 is 0.3 mm.

[0050] In order to lower the mold temperature and enable rapid heat exchange to solidify the molten plastic, cooling water channels are arranged in a crisscross pattern inside the mold, and the water channels on the side close to the inner liner die 5 are more densely distributed to improve the heat exchange efficiency. The rest are used as auxiliary cooling for the mold, and the number is relatively small, which saves the mold opening cost and ensures that the cooling effect meets the cooling and solidification requirements. The aperture size of the fine pores 8 is limited within a certain range, which can not only achieve exhaust but also avoid the situation where plastic enters the fine pores 8 under the action of air pressure to cause blockage or an uneven product surface.

[0051] like Fig.10 and 11 As shown, the transmission mechanism 3 includes a gear base 31 which is transmission-connected to the driving device and fixed in position, the middle of the gear base 31 is fixedly connected to the connecting sleeve 42 of the lower connecting rod 44, and driving gears 32 are respectively arranged near the middle positions at both ends, and the driving gears 32 are transmission-connected to the output end of the driving device; It also includes two rack transmission assemblies corresponding to the driving gears 32 at both ends, and any of the rack transmission assemblies includes a first spur rack 33 and a second spur rack 34 that are relatively arranged on both sides of the driving gear 32 and mesh with the driving gear 32, one end of the first spur rack 33 is fixedly connected to the left mold base 1 through a first fixing rod 35, and the opposite end of the second spur rack 34 is fixedly connected to the right mold base 2 through a second fixing rod 36; The gear base 31 is provided with guide holes 37 at both ends, and guide shafts 38 are installed in the guide holes 37. The guide shafts 38 are located on both sides of the gear base 31 and are respectively provided with guide rods 39 fixedly connected to the left mold base 1 and the right mold base 2.

[0052] The double gear transmission at the bottom ensures that the mold remains synchronized during the movement process. The setting of the guide structure ensures the consistency of direction during the movement of the mold, making the mold closing action more precise and further improving the production quality of the product.

[0053] The manufacturing process of the mold for making a type IV hydrogen gas storage tank includes the following steps: Step 1: Unloading and mold closing The cylindrical molten plastic liner raw material is squeezed downward by a discharge device arranged just above the fixed installation rod 4, so that the fixed installation rod 4 is inserted into the hollow part of the cylindrical plastic liner raw material until the lower end of the plastic liner raw material completely covers the connecting sleeve 42 of the lower connecting rod 44, and the transmission mechanism 3 is started to move the left mold base 1 and the right mold base 2 closer to the inside until the left mold base 1 contacts the right mold base 2, and the positioning wedge block 102 is embedded in the positioning wedge groove 101; Step 2: Blow molding After the mold is closed, the gas flows through the fixed mounting rod 4 and is filled into the mold through the air blowing pipeline, and the molten plastic liner raw material is filled with gas until it fits the inner wall of the liner cavity mold 5, and is cooled and solidified after being cooled by the left mold base 1 and the right mold base 2; Step 3: Edge grinding After the cooling and solidification stage, the mold is opened to take out the solidified type IV hydrogen gas storage tank, and the excess plastic produced by the side seam extrusion during the mold closing process is trimmed and polished to make the surface roughness of the type IV hydrogen gas storage tank less than or equal to 1.6 microns.

[0054] During the mold closing process of step 1, when the left mold base 1 and the right mold base 2 are squeezed with the plastic liner raw material, inward pressure is generated, so that the plastic liner raw material gradually adheres to the surface of the metal lining 41 as the left mold base 1 and the right mold base 2 move until the mold closing is completed. The molten plastic liner raw material is squeezed through the mold and filled into the vertical stop groove 413 and the horizontal stop groove 414.

[0055] The gas pressure value of the gas introduced into the mold in step 2 is 0.8 MPa; The left mold base 1 and the right mold base 2 are kept at a temperature of 30° C. by controlling the flow rate of the cooling water pipe 103; during the application optimization process, the state of the bottle body structure after solidification and molding can be observed through multiple cooling experiments, and the lowest temperature under the condition that the bottle body structure is not affected can be tested to speed up the solidification time, shorten the overall manufacturing time, and improve production efficiency.

[0056] After the mold is closed, the cooling and solidification are completed within 3 minutes, and the mold is opened to proceed to step 3.

[0057] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0058] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A mold for manufacturing a type IV hydrogen storage tank, comprising a mold and a transmission mechanism (3) installed below the mold, characterized in that: The mold comprises a left mold base (1) and a right mold base (2) which are symmetrically arranged, and the left mold base (1) and the right mold base (2) are simultaneously moved inward or outward by a transmission mechanism (3) arranged below the mold, and further comprises a fixed mounting rod (4) whose lower end is fixedly connected to the transmission mechanism (3), and both ends of the fixed mounting rod (4) are respectively provided with metal lining parts (41), and the fixed mounting rod (4) is arranged as a hollow structure with a hole on the side surface, which is connected to the blowing pipeline; The left mold base (1) and the right mold base (2) both comprise an inner liner die (5) with a smooth curved surface in the middle and bottle mouth dies (6) arranged at both ends of the inner liner die (5); both ends of the left mold base (1) and the right mold base (2) are provided with residual material dies (7) communicating with the outside of the mold; and the inner wall of the inner liner die (5) is provided with fine air holes (8) communicating with the outside of the mold; The metal lining member (41) comprises a vertical limiting portion (411) provided with a gap with the bottle mouth die (6) and a curved limiting portion (412) provided with a gap with the liner die (5); a vertical stop groove (413) and a transverse stop groove (414) are provided on the outer side of the vertical limiting portion (411); and a transverse stop groove (414) is provided on the edge of the curved limiting portion (412).

2. The mold for making a type IV hydrogen gas storage tank according to claim 1, characterized in that: A truncated boss (9) is provided at the connection between the upper end of the bottle mouth cavity die (6) and the residual material cavity die (7); after the molds are closed, the truncated boss (9) on the left mold base (1) and the right mold base (2) abut against the fixed mounting rod (4), and the truncated bosses (9) on both sides are combined to form a closed circular truncated surface.

3. The mold for making a type IV hydrogen gas storage tank according to claim 2, characterized in that: The fixed installation rod (4) comprises a connecting rod and connecting sleeves (42) provided at both ends of the connecting rod and provided with external threads, the metal lining (41) is threadedly connected to the connecting sleeve (42), and after mold closing, the truncated boss (9) abuts against the outer side surface of the connecting sleeve (42); The connecting rod comprises an upper connecting rod (43) and a lower connecting rod (44); an end of either the upper connecting rod (43) or the lower connecting rod (44) away from the connecting sleeve (42) is provided with a plug-in recessed groove (45); an end of the other connecting rod close to the plug-in recessed groove (45) is provided with a plug-in key (46) matching the plug-in recessed groove (45); and an upper end of the connecting sleeve (42) at the end of the upper connecting rod (43) is provided with a process groove (47) for matching with a rotating tool.

4. The mold for making a type IV hydrogen gas storage tank according to claim 1, characterized in that: Both ends of the left mold base (1) and the right mold base (2) are provided with sunken flash material cutting areas (10) on the left and right sides of the bottle mouth die (6), the residual material die (7) and the shoulder of the liner die (5), and the edges of the bottle mouth die (6), the residual material die (7) and the shoulder of the liner die (5) are in the same plane as the edge of the bottle body of the liner die (5).

5. The mold for making a type IV hydrogen gas storage tank according to claim 4, characterized in that: A positioning wedge groove (101) is provided at the edge of the flash material cutting area (10), a positioning wedge block (102) is fixedly arranged in any positioning wedge groove (101), the shape of the other positioning wedge groove (101) matches the shape of the positioning wedge block (102), and the positioning wedge block (102) is embedded in the other positioning wedge groove (101) after mold closing.

6. The mold for making a type IV hydrogen gas storage tank according to claim 1, characterized in that: Cooling water pipes (103) are arranged inside the left mold base (1) and the right mold base (2), and any of the cooling water pipes (103) penetrates the mold to be connected to an external water channel. The cooling water pipes (103) are arranged in at least two layers along the thickness direction of the mold, and the number of cooling water pipes (103) increases from the outside to the inside. Exhaust pipelines are also provided inside the left mold base (1) and the right mold base (2), and any of the exhaust pipelines is connected to a fine air hole (8) and is connected to the outside of the mold through the exhaust pipeline. The fine air hole (8) has a diameter of 0.2 mm to 0.4 mm.

7. The mold for making a type IV hydrogen gas storage tank according to claim 1, characterized in that: The transmission mechanism (3) comprises a gear base (31) which is transmission-connected to the driving device and is fixed in position; the middle of the gear base (31) is fixedly connected to the connecting sleeve (42) of the lower connecting rod (44); driving gears (32) are respectively arranged at both ends near the middle; the driving gears (32) are transmission-connected to the output end of the driving device; It also includes two rack transmission assemblies arranged corresponding to the driving gears (32) at both ends, and any of the rack transmission assemblies includes a first spur rack (33) and a second spur rack (34) arranged relatively on both sides of the driving gear (32) and meshing with the driving gear (32), one end of the first spur rack (33) is fixedly connected to the left mold base (1) via a first fixing rod (35), and the opposite end of the second spur rack (34) is fixedly connected to the right mold base (2) via a second fixing rod (36); Guide holes (37) are provided at both ends of the gear base (31), guide shafts (38) are installed in the guide holes (37), and guide rods (39) are respectively fixedly connected to the left mold base (1) and the right mold base (2) and are located on both sides of the gear base (31).

8. A process for manufacturing a mold for a type IV hydrogen storage tank according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Unloading and mold closing The cylindrical molten plastic liner raw material is extruded downward by a discharge device arranged just above the fixed mounting rod (4), so that the fixed mounting rod (4) is inserted into the hollow portion of the cylindrical plastic liner raw material until the lower end of the plastic liner raw material completely covers the connecting sleeve (42) of the lower connecting rod (44), and the transmission mechanism (3) is started to move the left mold base (1) and the right mold base (2) closer to the inside until the left mold base (1) and the right mold base (2) are in contact, and the positioning wedge block (102) is embedded in the positioning wedge groove (101); Step 2: Blow molding After the mold is closed, the gas flows through the fixed mounting rod (4) and is filled into the mold through the air blowing pipeline, and the molten plastic liner raw material is filled with gas until it fits the inner wall of the liner cavity mold (5), and is cooled by the left mold base (1) and the right mold base (2) to achieve cooling and solidification; Step 3: Edge grinding After the cooling and solidification stage, the mold is opened to take out the solidified type IV hydrogen gas storage tank, and the excess plastic produced by the side seam extrusion during the mold closing process is trimmed and polished to make the surface roughness of the type IV hydrogen gas storage tank less than or equal to 1.6 microns.

9. The manufacturing process of the IV type hydrogen gas storage tank according to claim 8, characterized in that: During the mold closing process of step 1, when the left mold base (1) and the right mold base (2) are squeezed with the plastic liner raw material, inward pressure is generated, so that the plastic liner raw material gradually adheres to the surface of the metal liner (41) as the left mold base (1) and the right mold base (2) move, until the mold closing is completed, and the molten plastic liner raw material is squeezed through the mold and filled into the vertical stop groove (413) and the horizontal stop groove (414).

10. The manufacturing process of the IV type hydrogen gas storage tank according to claim 9, characterized in that: The gas pressure of the gas introduced into the mold in step 2 is 0.6 MPa to 0.8 MPa; The left mold base (1) and the right mold base (2) are maintained at a temperature of 28°C to 32°C by controlling the flow rate of the cooling water pipe (103); After the mold is closed, the cooling and solidification are completed within 3 minutes, and the mold is opened to proceed to step 3.

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