Blow molding high-pressure inner container with preset metal pipe orifice and production method

Abstract

The invention relates to the technical field of blowing of high-pressure storage tanks, in particular to a blow-molded high-pressure inner container with a preset metal pipe opening and a production method. The high-pressure inner container comprises a blow molding inner container and a metal pipe opening installed at an opening of the blow molding inner container. The metal pipe opening comprises a fixing piece coaxially installed on the inner side of the neck portion, an outer clamping hoop installed on the outer side of the neck portion in a sleeving mode and a locking nut connected to the fixing piece through threads. The inner end of the fixing piece is provided with a disc body clamped at the opening of the blow molding inner container, and the outer end of the fixing piece extends out of the blow molding inner container and is provided with an external thread used for installing the locking nut; the lower end of the outer clamping hoop and the disc body jointly form a clamping mechanism for the blow molding inner container, and the upper end of the outer clamping hoop abuts against the lower face of the locking nut. According to the high-pressure inner container, a large fixing piece can be pre-arranged in the blow molding inner container, a metal pipe opening is firmly connected, the sealing performance is good, and the compressive strength is high; and special requirements on the strength of the shoulder part and the neck part of the blow-molded inner container are avoided, so that the material consumption of the plastic inner container is reduced, and the overall weight is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of blowing of high-pressure storage tanks, in particular to a blow-molded high-pressure inner liner with a preset metal nozzle and a production method. Background Art

[0002] Automotive hydrogen is stored at high pressure in hydrogen storage cylinders. Currently, there are four types of hydrogen storage cylinders: all-metal cylinders, metal liner fiber hoop-wrapped cylinders, metal liner fiber fully wrapped cylinders, and non-metallic liner fiber fully wrapped cylinders. All-metal cylinders, metal liner fiber hoop-wrapped cylinders, and metal liner fiber fully wrapped cylinders have relatively large weight and volume, and it is difficult to meet the hydrogen storage density requirements per unit mass. They are not ideal for on-board hydrogen supply systems. Non-metallic liner fiber fully wrapped cylinders have the defect of a loose connection between the metal bottle mouth and the non-metallic liner, and are prone to hydrogen leakage risks during use, posing a great safety hazard. Chinese patent application 2019101499077 discloses "A Plastic Liner Carbon Fiber Fully Wrapped Hydrogen Storage Cylinder", the application publication number is CN109751506A, the hydrogen storage cylinder has a metal bottle mouth, a plastic liner and a metal cover plate, a threaded through hole that runs through from top to bottom is opened on the metal cover plate, and a vertical folded edge that bends downward is set on the edge of the metal cover plate; the metal bottle mouth and the plastic liner are blow-molded as a whole, an annular receiving groove that is recessed inward is set on the top of the plastic liner, an internal thread that can be matched and connected with the bottle mouth valve is set on the inner side wall of the metal bottle mouth, and an external thread that is matched and connected with the threaded through hole is set on the outer side wall of the metal bottle mouth. When the metal cover plate is sealed and screwed on the metal bottle mouth, the vertical folded edge is embedded in the annular receiving groove. The hydrogen storage cylinder grasps the shoulder of the plastic liner through the claws on the metal cover plate to achieve the purpose of firm connection and improved safety performance. Since the claws on the metal cover need to be deep enough to fit into the annular receiving groove on the shoulder of the plastic liner and cannot penetrate the plastic liner, the shoulder of the plastic liner is thicker than other parts, increasing the weight of the liner. In addition, when the plastic liner is subjected to a large axial force, the claws on the metal cover still face the risk of detaching from the annular receiving groove. The connection between the metal bottle mouth and the plastic liner of the hydrogen storage cylinder is still a weak link in terms of pressure resistance and sealing, and the reliability of the connection needs to be further improved. Summary of the invention

[0003] In order to solve the problems of the above-mentioned prior art, the present invention provides a blow-molded high-pressure liner and a production method with a pre-set metal nozzle, which has a firm metal nozzle connection, good sealing performance and high compressive strength. While ensuring that the metal nozzle is firmly connected and has good sealing performance, the amount of material used in the plastic liner is minimized and the overall weight is reduced.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] The blow-molded high-pressure liner with a preset metal nozzle described in the present invention comprises a blow-molded liner and a metal nozzle installed at the opening of the blow-molded liner, an axially extending neck is provided at the opening of the blow-molded liner, the neck is connected to the liner body through a shoulder to form a whole, the diameter of the neck is smaller than the liner body, and the metal nozzle comprises a fixing part coaxially installed on the inner side of the neck, an external clamp sleeved on the outer side of the neck, and a locking nut threadedly connected to the fixing part; the inner end of the fixing part has a disk body clamped on the inner wall of the shoulder, the outer end of the fixing part extends out of the neck and is provided with an external thread for installing the locking nut; the lower end of the external clamp and the disk body together form a clamping mechanism for the shoulder of the blow-molded liner, and the upper end of the external clamp abuts against the bottom of the locking nut.

[0006] With the above structural design, the locking nut and the fixing part form a threaded connection structure that is pulled up and pressed down. The locking nut forms pressure on the shoulder of the blow-molded liner through the external clamp, and the disc of the locking nut forms support for the shoulder of the blow-molded liner from the inside. The metal pipe mouth is firmly connected and has good sealing performance. There are no special requirements for the strength of the shoulder and neck of the blow-molded liner, which is beneficial to reducing the amount of material used for the plastic liner and reducing the overall weight.

[0007] Preferably, the fixing member is a gyroscope, a channel connected to the inner cavity of the blow-molded liner is arranged at the axis of the fixing member, a flared section is arranged at the outer end of the channel, the diameter of the flared section is larger than the channel, and the flared section is provided with an internal thread.

[0008] By adopting the above structural design, the position of the fixing part can be easily fixed during the blow molding process and incorporated into the blow molded blank.

[0009] Preferably, the channel and the flared section are connected via a trumpet-shaped transition section.

[0010] By adopting the above structural design, the fixing part can be installed on the top of the air needle of the blow molding machine.

[0011] Preferably, the channel and the flared section are connected via a right-angle step.

[0012] By adopting the above structural design, the fixing part can be installed on the top of the air needle of the blow molding machine.

[0013] Preferably, a fixing pin is provided on the locking nut.

[0014] The above structural design can prevent the locking nut from loosening.

[0015] Preferably, the outer contour of the outer clamp is a conical structure that is larger at the bottom and smaller at the top, the outer diameter of the bottom of the outer clamp is adapted to the outer diameter of the disk body, and the outer diameter of the upper end surface of the outer clamp is adapted to the locking nut; a center hole that adapts to the neck is provided at the axis of the outer clamp.

[0016] The above structural design can reduce the weight of the outer clamp and enhance the clamping force on the shoulder of the blow-molded inner liner.

[0017] Preferably, a circular arc transition is formed between the neck and the shoulder of the blow-molded inner shell, and a circular arc transition is formed between the center hole and the bottom surface of the outer clamp.

[0018] The above structural design can improve the tensile strength between the neck and the shoulder.

[0019] The method for producing a blow-molded high-pressure liner with a preset metal nozzle of the present invention comprises the following steps:

[0020] 1) preparing a metal pipe mouth, the metal pipe mouth comprising a fixing piece, an external clamp, and a locking nut threadedly connected to the fixing piece; the inner end of the fixing piece has a disc body, the outer end of the fixing piece extends out of the neck and is provided with an external thread for installing the locking nut, and a channel is provided at the axis of the fixing piece;

[0021] 2) Install the fixing piece on the air needle of the blow molding machine through the channel and set it just below the extruder;

[0022] 3) The extruder extrude the cylindrical billet, causing the billet to fall and be sheathed on the fixing piece and the air needle;

[0023] 4) Clamp the mold and blow air with an air needle to form a blow-molded liner from the blank;

[0024] 5) The air needle withdraws from the mold;

[0025] 6) Demoulding and taking out the blow moulded liner;

[0026] 7) Using a probe to reach into the inner cavity of the blow-molded liner from the opening of the blow-molded liner, grab the fixing piece and pull the fixing piece (3) to the opening of the blow-molded liner;

[0027] 8) Place the outer clamp over the opening of the blow-molded liner and connect the locking nut to the fixing.

[0028] By adopting the method, the fixing piece is arranged inside the blow-molded blank before the plastic is blown, and the size of the fixing piece is not limited by the diameter of the opening of the blow-molded liner. The metal pipe mouth is firmly connected, has good sealing performance and high compressive strength.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] A larger fixing piece can be pre-set in the blow-molded liner, and the neck and shoulder of the blow-molded liner can be tightened by the fixing piece in the blow-molded liner, the external clamp on the outside of the blow-molded liner, and the locking nut; the metal pipe mouth is firmly connected, the sealing performance is good, and the compressive strength is high; there is no special requirement for the strength of the shoulder and neck of the blow-molded liner, which is conducive to reducing the amount of material used for the plastic liner and reducing the overall weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The figure is a partial cross-sectional structural schematic diagram of a blow-molded high-pressure liner with a preset metal nozzle according to an embodiment of the present invention.

[0032] Figure 2 for Figure 1 Schematic diagram of the assembly structure of the embodiment

[0033] Figure 3 It is a schematic diagram of a method for producing a blow-molded high-pressure liner with a preset metal nozzle. DETAILED DESCRIPTION

[0034] 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.

[0035] like Figure 1 , Figure 2 As shown, the blow-molded high-pressure liner with a preset metal nozzle of the present invention includes a blow-molded liner 1 and a metal nozzle installed at the opening of the blow-molded liner 1, and an axially extending neck 2 is provided at the opening of the blow-molded liner 1. The neck 2 is connected to the liner body 22 through a shoulder 21 to form a whole. The diameter of the neck 2 is smaller than the liner body 22. The liner body 22 can be circular, elliptical or columnar. The neck 2 is a tubular structure. The neck 2, the shoulder 21 and the liner body 22 are integrally formed by a blow molding process and have substantially the same wall thickness.

[0036] like Figure 1As shown, the metal nozzle includes a fixing member 3 coaxially mounted on the inner side of the neck 2, an outer clamp 4 sleeved on the outer side of the neck 2, and a locking nut 5 connected to the fixing member 3 by threading. The fixing member 3, the outer clamp 4 and the locking nut 5 are all made of copper or stainless steel or other corrosion-resistant metals or alloy materials, with high strength and high toughness, and can be used for high-pressure containers such as hydrogen storage cylinders; the inner end of the fixing member 3 is provided with a disc body 31 clamped on the inner wall of the shoulder 21, and the disc body 31 is a disc-shaped structure, and its upper surface contour fits the inner wall of the shoulder 21. The outer end of the fixing member 3 extends upward from the neck 2 and is provided with an external thread for installing the locking nut 5; the lower end of the outer clamp 4 and the disc body 31 together form a clamping mechanism for the shoulder 21 of the blow-molded liner 1, and the upper end of the outer clamp 4 abuts against the bottom of the locking nut 5. In addition, in order to prevent the locking nut 5 from loosening, a fixing pin 6 is provided on the locking nut 5. The fixing pin 6 is a screw installed on the side wall of the locking nut 5 through a thread. After the locking nut 5 is installed in place, the fixing pin 6 is rotated using a tool such as a screwdriver so that its front end passes through the side wall of the locking nut 5 and presses on the fixing piece 3 to fix the position of the locking nut 5.

[0037] like Figure 2 As shown, the fixing member 3 is a gyroscope, and a channel 33 connected to the inner cavity of the blow molded liner 1 is arranged at the axis of the fixing member 3, and a flaring section 32 is arranged at the outer end of the channel 33, and the diameter of the flaring section 32 is larger than that of the channel 33, and the flaring section 32 is provided with an internal thread. The channel 33 and the flaring section 32 are connected by a flared transition section or a right-angle step. In this way, the channel 33 forms a through hole with a large outer diameter and a small inner diameter.

[0038] As a further improvement of the present invention, the outer contour of the outer clamp 4 is a frustum-shaped structure with a larger bottom and a smaller top, the outer diameter of the bottom of the outer clamp 4 is adapted to the outer diameter of the disc 31, and the outer diameter of the upper end surface of the outer clamp 4 is adapted to the locking nut 5; the axis of the outer clamp 4 is provided with a center hole adapted to the neck 2. The neck 2 and the shoulder 21 of the blow-molded liner 1 are transitioned by an arc, and the center hole and the bottom surface of the outer clamp 4 are transitioned by an arc.

[0039] The method for producing a blow-molded high-pressure liner with a preset metal nozzle of the present invention comprises the following steps:

[0040] 1) preparing a metal pipe nozzle, the metal pipe nozzle comprising a fixing part 3, an outer clamp 4, and a locking nut 5 connected to the fixing part 3 by threads; the inner end of the fixing part 3 is provided with a disc 31, the outer end of the fixing part 3 extends out of the neck 2 and is provided with an external thread for installing the locking nut 5, and a channel 33 is provided at the axis of the fixing part 3;

[0041] 2) If Figure 3As shown in the upper left pattern, the blow molding machine mold 9 is composed of a left and right shell that can be opened and closed, a liftable air needle 91 is arranged below the mold 9, and an extruder 92 is arranged above the mold 9. Figure 3 As shown in the middle figure on the left, the fixing member 3 is installed on the air needle of the blow molding machine through the channel 33 and is arranged just below the extruder;

[0042] 3) After the fixing member 3 is installed in place, Figure 3 As shown in the lower left pattern, the extruder extrude a cylindrical blank 93, so that the blank 93 falls and is sleeved on the fixing member 3 and the air needle until the length of the blank 93 meets the mold closing requirement;

[0043] 4) If Figure 3 As shown in the upper right pattern, after the length of the blank 93 meets the mold closing requirement, the blow molding machine closes the mold and the left and right shells are merged together. Then the air needle 91 blows air into the blank 93 so that the blank is tightly attached to the inner wall of the mold to form a blow-molded liner 1;

[0044] 5) If Figure 3 As shown in the middle figure on the right, after the blow-molded liner 1 is formed, the air needle 91 is separated from the fixing member 3 and the blow-molded liner is withdrawn from the mold;

[0045] 6) If Figure 3 As shown in the pattern at the lower right end. After the air needle 91 is withdrawn, the blow molding machine is demoulded, and the left and right shells are separated. At this time, the blow-molded liner 1 can be taken out, and the fixing part 3 remains in the inner cavity of the blow-molded liner 1;

[0046] 7) Use a probe to extend into the inner cavity of the blow-molded liner from the opening of the blow-molded liner to grab the fixing part 3 and pull the fixing part 3 to the opening of the blow-molded liner; the probe is a slender rod with an external thread at the front end, and the external thread at the front end of the probe is adapted to the internal thread in the channel 33 of the fixing part 3. The thread at the front end of the probe is screwed into the internal thread of the fixing part 3, and the fixing part 3 can be pulled to the opening of the blow-molded liner 1 through the probe.

[0047] 8) Sleeve the outer clamp 4 on the opening of the blow-molded inner liner, and connect the locking nut 5 to the fixing piece 3 to complete the assembly of the metal pipe mouth.

[0048] In addition, when used as a hydrogen storage cylinder, a carbon fiber layer can be wrapped or wound on the outer wall of the blow-molded inner liner 1 to further improve the pressure resistance.

[0049] The contents not described in detail in this specification belong to the prior art known to the professional and technical personnel in this field. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for the technical solutions described in the aforementioned embodiments to be modified, or some of the technical features thereof to be replaced by equivalents, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A blow-molded high-pressure liner with a pre-set metal nozzle, comprising a blow-molded liner (1) and a metal nozzle installed at the opening of the blow-molded liner (1), wherein the opening of the blow-molded liner (1) is provided with an axially extending neck (2), wherein the neck (2) is connected to a liner body (22) via a shoulder (21) to form a whole, and the caliber of the neck (2) is smaller than that of the liner body (22), and characterized in that: The metal nozzle comprises a fixing member (3) coaxially mounted on the inner side of the neck (2), an outer clamp (4) sleeved on the outer side of the neck (2), and a locking nut (5) threadedly connected to the fixing member (3); the inner end of the fixing member (3) is provided with a disk body (31) clamped on the inner wall of the shoulder (21), the outer end of the fixing member (3) protrudes out of the neck (2) and is provided with an external thread for mounting the locking nut (5); the lower end of the outer clamp (4) and the disk body (31) together form a clamping mechanism for the shoulder (21) of the blow-molded liner (1), and the upper end of the outer clamp (4) abuts against the bottom of the locking nut (5).

2. The blow-molded high-pressure liner with a preset metal nozzle according to claim 1, characterized in that: The fixing member (3) is a rotating body, and a channel (33) communicating with the inner cavity of the blow-molded liner (1) is arranged at the axis of the fixing member (3), and a flaring section (32) is arranged at the outer end of the channel (33), the diameter of the flaring section (32) is larger than that of the channel (33), and the flaring section (32) is provided with an internal thread.

3. The blow-molded high-pressure liner with a preset metal nozzle according to claim 2, characterized in that: The channel (33) is connected to the expanded section (32) via a trumpet-shaped transition section.

4. The blow-molded high-pressure liner with a preset metal nozzle according to claim 2, characterized in that: The channel (33) is connected to the expanded section (32) via a right-angle step.

5. The blow-molded high-pressure liner with a preset metal nozzle according to claim 1 or 2, characterized in that: The locking nut (5) is provided with a fixing pin (6).

6. The blow-molded high-pressure liner with a preset metal nozzle according to claim 1 or 2, characterized in that: The outer contour of the outer clamp (4) is a conical structure with a larger bottom and a smaller top. The outer diameter of the bottom of the outer clamp (4) is adapted to the outer diameter of the disk body (31), and the outer diameter of the upper end surface of the outer clamp (4) is adapted to the locking nut (5). A center hole adapted to the neck (2) is provided at the axis of the outer clamp (4).

7. The blow-molded high-pressure liner with a preset metal nozzle according to claim 6, characterized in that: The neck (2) and the shoulder (21) of the blow-molded liner (1) are transitioned through an arc, and the center hole and the bottom surface of the outer clamp (4) are transitioned through an arc.

8. A method for producing a blow-molded high-pressure liner with a pre-set metal nozzle, characterized in that The steps include: 1) preparing a metal pipe mouth, the metal pipe mouth comprising a fixing part (3), an external clamp (4), and a locking nut (5) connected to the fixing part (3) by threads; the inner end of the fixing part (3) is provided with a disc (31), the outer end of the fixing part (3) extends out of the neck (2) and is provided with an external thread for mounting the locking nut (5), and a channel (33) is provided at the axis of the fixing part (3); 2) The fixing member (3) is mounted on the air needle of the blow molding machine through the channel (33), and is arranged just below the extruder; 3) The extruder extrude a cylindrical billet, causing the billet to fall and be sleeved on the fixing member (3) and the air needle; 4) Clamp the mold and blow air with an air needle to form a blow-molded liner from the blank; 5) The air needle withdraws from the mold; 6) Demoulding and taking out the blow moulded liner; 7) Using a probe to extend into the inner cavity of the blow-molded liner from the opening of the blow-molded liner, grab the fixing member (3) and pull the fixing member (3) to the opening of the blow-molded liner; 8) Sleeve the outer clamp (4) over the opening of the blow-molded inner liner, and connect the locking nut (5) to the fixing member (3).

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