Blow-molded high-pressure liner with pre-installed metal nozzle, and production method

Abstract

The present invention relates to the technical field of blowing of high-pressure storage tanks, and particularly relates to a blow-molded high-pressure liner with a pre-installed metal nozzle, and a production method. The high-pressure liner comprises a blow-molded liner and a metal nozzle mounted at an opening of the blow-molded liner. The metal nozzle comprises a fixing member coaxially mounted on the inner side of a neck of the blow-molded liner, an outer clamp sleeved on the outer side of the neck of the blow-molded liner, and a locknut connected to the fixing member in a threaded manner, wherein the inner end of the fixing member is provided with a disk snap-fitted at the opening of the blow-molded liner, and the outer end of the fixing member extends from the blow-molded liner and is provided with an external thread for mounting the locknut; and the lower end of the outer clamp and the disk jointly form a clamping mechanism of the blow-molded liner, and the upper end of the outer clamp abuts against the lower surface of the locknut. The high-pressure liner allows for the pre-installation of the relatively large fixing member in the blow-molded liner, features firm connection, good sealing performance and high compressive strength of the metal nozzle, and has no special requirements for the strength of the shoulder and neck of the blow-molded liner, thereby facilitating a reduction in the amount of materials used for the plastic liner and a reduction in the overall weight.

Description

Blow molding high-pressure liner with pre-installed metal pipe mouth and production method TECHNICAL FIELD

[0001] The present application relates to the technical field of blow molding high-pressure liner with pre-installed metal pipe mouth and production method. BACKGROUND

[0002] The hydrogen used in vehicles is stored in hydrogen storage cylinders. There are currently four types of hydrogen storage cylinders: all-metal cylinders, metal liner fiber hoop winding cylinders, metal liner fiber full winding cylinders, and non-metal liner fiber full winding cylinders. The all-metal cylinders, metal liner fiber hoop winding cylinders, and metal liner fiber full winding cylinders have a large weight-to-volume ratio, making it difficult to meet the unit mass hydrogen storage density requirements, and are not ideal for vehicle hydrogen supply systems. The non-metal liner fiber full winding cylinder has a defect of a weak connection between the metal cylinder mouth and the non-metal liner, and there is a risk of hydrogen leakage during use, which poses a great safety hazard. Chinese Patent Application 2019101499077 discloses a "plastic liner carbon fiber full winding hydrogen storage cylinder", with an application publication number of CN109751506A. The hydrogen storage cylinder has a metal cylinder mouth, a plastic liner, and a metal cover plate. A threaded hole is formed through the metal cover plate, and a vertical folding edge is provided on the edge of the metal cover plate. The metal cylinder mouth and the plastic liner are integrally blow molded, and an inwardly recessed annular receiving groove is provided on the top of the plastic liner. An internal thread is provided on the inner side wall of the metal cylinder mouth, which can be matched and connected with the cylinder valve. An external thread is provided on the outer side wall of the metal cylinder mouth, which is matched and connected with the threaded hole. When the metal cover plate is tightly sealed and screwed onto the metal cylinder mouth, the vertical folding edge is clamped in the annular receiving groove. The hydrogen storage cylinder uses the clamping jaw on the metal cover plate to grab the shoulder of the plastic liner, achieving a firm connection and improving safety performance. However, the annular receiving groove in the shoulder of the plastic liner needs to have sufficient depth and cannot penetrate the plastic liner, so the thickness of the shoulder of the plastic liner is greater than that of other parts, increasing the weight of the liner. In addition, when the plastic liner is subjected to a large axial force, there is still a risk of the clamping jaw on the metal cover plate detaching from the annular receiving groove. The connection between the metal cylinder 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. TECHNICAL PROBLEM

[0003] To solve the above-mentioned problems of the prior art, the present application provides a blow molding high-pressure liner with pre-installed metal pipe mouth and production method, which has a firm connection, good sealing performance, and high pressure resistance. The use of material for the plastic liner is minimized and the overall weight is reduced while ensuring a firm connection and good sealing performance of the metal pipe mouth. TECHNICAL SOLUTION

[0004] To achieve the above-mentioned purposes, the present application provides the following technical solutions:

[0005] The blow molding high-pressure inner container with a preset metal pipe mouth comprises a blow molding inner container and a metal pipe mouth installed at the opening of the blow molding inner container, the opening of the blow molding inner container is provided with an axially extending neck, the neck is connected with the body of the container through a shoulder to become an integral whole, the caliber of the neck is smaller than that of the body of the container, the metal pipe mouth comprises a fixing part coaxially installed inside the neck, an outer clamp sleeved outside the neck, and a locking nut threadedly connected on the fixing part; the inner end of the fixing part is provided with a disc clamped on the inner wall of the shoulder, and the outer end of the fixing part extends out of the neck and is provided with an outer thread for installing the locking nut; the lower end of the outer clamp cooperates with the disc to form a clamping mechanism for the shoulder of the blow molding inner container, and the upper end of the outer clamp abuts against the lower surface of the locking nut.

[0006] With the above structure, the locking nut and the fixing part form an upward pulling and downward pressing threaded connection structure, the locking nut forms pressure on the shoulder of the blow molding inner container through the outer clamp, and the disc of the locking nut forms support on the shoulder of the blow molding inner container from the inside, the metal pipe mouth is firmly connected and has good sealing performance, and the strength of the shoulder and the neck of the blow molding inner container has no special requirements, which is conducive to reducing the material amount of the plastic inner container and reducing the overall weight.

[0007] Preferably, the fixing part is a convolution, the axis of the fixing part is provided with a channel communicating with the inner cavity of the blow molding inner container, the outer end of the channel is provided with an expanded section, the diameter of the expanded section is larger than that of the channel, and the expanded section is provided with an inner thread.

[0008] With the above structure, the position of the fixing part can be fixed during the blow molding process and be incorporated into the blow molding blank.

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

[0010] With the above structure, the fixing part can be installed at the top end of the air needle of the blow molding machine.

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

[0012] With the above structure, the fixing part can be installed at the top end of the air needle of the blow molding machine.

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

[0014] With the above structure, the locking nut can be prevented from loosening.

[0015] Preferably, the outer contour of the outer clamp is a conical frustum structure with the bottom larger than the top, the outer diameter of the bottom of the outer clamp is adapted to the outer diameter of the disc, the outer diameter of the upper end surface of the outer clamp is adapted to the locking nut, and the axis of the outer clamp is provided with a central hole adapted to the neck.

[0016] The above structure design can reduce the weight of the outer clamp, and enhance the clamping force on the shoulder of the blow molding inner liner.

[0017] Preferably, the neck and the shoulder of the blow molding inner liner are connected through a circular arc, and the center hole and the bottom surface of the outer clamp are connected through a circular arc.

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

[0019] The production method of the blow molding high-pressure inner liner with a preset metal pipe mouth comprises the following steps:

[0020] 1) preparing a metal pipe mouth, which comprises a fixing part, an outer clamp, and a locking nut connected to the fixing part through threads; the inner end of the fixing part is provided with a disc, the outer end of the fixing part extends a neck and is provided with external threads for mounting the locking nut, and the axis of the fixing part is provided with a channel;

[0021] 2) mounting the fixing part on the air needle of a blow molding machine through the channel, and arranging the fixing part directly below an extruder;

[0022] 3) extruding a cylindrical blank by the extruder, so that the blank falls and is sleeved on the fixing part and the air needle;

[0023] 4) closing the mold and blowing air by the air needle, so that the blank forms a blow molding inner liner;

[0024] 5) withdrawing the air needle from the mold;

[0025] 6) demolding and taking out the blow molding inner liner;

[0026] 7) inserting a probe into the inner cavity of the blow molding inner liner from the opening of the blow molding inner liner to grab the fixing part and pull the fixing part (3) to the opening of the blow molding inner liner;

[0027] 8) sleeving the outer clamp on the opening of the blow molding inner liner, and connecting the locking nut to the fixing part.

[0028] In the above method, the fixing part is arranged inside the blow molding blank before blow molding, the size of the fixing part is not limited by the caliber of the opening of the blow molding inner liner, the metal pipe mouth is firmly connected, has good sealing performance, and has high compressive strength. Advantages

[0029] Compared with the prior art, the advantages of the present application are:

[0030] The large size fixing member can be pre-installed in the blow molding inner container, and the neck and shoulder of the blow molding inner container are compressed by the fixing member in the blow molding inner container and the outer clamp and locking nut outside the blow molding inner container; the metal pipe mouth is connected firmly, has good sealing performance, and has high compression strength; the strength of the shoulder and neck of the blow molding inner container has no special requirements, which is beneficial to reduce the material amount of the plastic inner container and reduce the overall weight. BRIEF DESCRIPTION OF DRAWINGS

[0031] Fig. 1 is a partial cross-sectional structure schematic diagram of a blow molding high pressure inner container with a pre-installed metal pipe mouth according to an embodiment of the present application.

[0032] Fig. 2 is an assembly structure schematic diagram of the embodiment of Fig. 1.

[0033] Fig. 3 is a schematic diagram of a production method of a blow molding high pressure inner container with a pre-installed metal pipe mouth. BEST MODE FOR CARRYING OUT THE INVENTION

[0034] Enter the best mode for carrying out the invention description paragraph here. EMBODIMENTS OF THE INVENTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] As shown in Fig. 1 and Fig. 2, the blow molding high pressure inner container with a pre-installed metal pipe mouth according to the present application comprises a blow molding inner container 1 and a metal pipe mouth installed at the opening of the blow molding inner container 1. The opening of the blow molding inner container 1 is provided with an axially extending neck 2, the neck 2 is connected with a body 22 through a shoulder 21 to form an integrated body, the caliber of the neck 2 is smaller than that of the body 22, the body 22 can be circular, elliptical or columnar structure, the neck 2 is a circular pipe structure, the neck 2, the shoulder 21 and the body 22 are integrally formed by blow molding process and have substantially the same wall thickness.

[0037] As shown in Fig. 1, the metal pipe mouth comprises a fixing member 3 coaxially installed inside the neck 2, an outer clamp 4 sleeved outside the neck 2, and a locking nut 5 threadedly connected to the fixing member 3. The fixing member 3, the outer clamp 4, and the locking nut 5 are made of copper, stainless steel, or other corrosion-resistant metal or alloy materials, and have high strength and high toughness, and can be used in high-pressure containers such as hydrogen storage cylinders. The inner end of the fixing member 3 is provided with a disc body 31 clamped to the inner wall of the shoulder 21. The disc body 31 has a disc-shaped structure, and the upper surface thereof is profiled to the inner wall of the shoulder 21. The outer end of the fixing member 3 extends upwardly beyond the neck 2 and is provided with an outer thread for mounting the locking nut 5. The lower end of the outer clamp 4 cooperates with the disc body 31 to form a clamping mechanism for the shoulder 21 of the blow molding liner 1, and the upper end of the outer clamp 4 abuts against the lower surface of the locking nut 5. In addition, in order to prevent the locking nut 5 from loosening, a fixing pin 6 is arranged on the locking nut 5. The fixing pin 6 is a screw rod installed through the thread on the side wall of the locking nut 5. After the locking nut 5 is installed in place, the fixing pin 6 is rotated by using a screwdriver or the like, so that the front end of the fixing pin 6 penetrates through the side wall of the locking nut 5 and is pressed against the fixing member 3, thereby fixing the position of the locking nut 5.

[0038] As shown in Fig. 2, the fixing member 3 is a convolute, and the axis of the fixing member 3 is provided with a passage 33 communicating with the inner cavity of the blow molding liner 1. The outer end of the passage 33 is provided with an expanded section 32 having a diameter larger than that of the passage 33, and the expanded section 32 is provided with an internal thread. The passage 33 and the expanded section 32 are connected through a trumpet-shaped transition section or a right-angle step. In this way, the passage 33 forms a through hole with a large outer diameter and a small inner diameter.

[0039] As a further improvement of the present application, the outer contour of the outer clamp 4 is a frustoconical structure with a large lower part and a small upper part. The outer diameter of the bottom of the outer clamp 4 is adapted to the outer diameter of the disc body 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 central hole adapted to the center hole of the neck 2. The neck 2 and the shoulder 21 of the blow molding liner 1 are connected through a circular arc transition, and the central hole and the bottom surface of the outer clamp 4 are connected through a circular arc transition.

[0040] The production method of the blow molding high-pressure liner with the preset metal pipe mouth comprises the following steps:

[0041] 1) preparing a metal pipe mouth, which comprises a fixing member 3, an outer clamp 4, and a locking nut 5 threadedly connected to the fixing member 3. The inner end of the fixing member 3 is provided with a disc body 31, the outer end of the fixing member 3 extends beyond the neck 2 and is provided with an outer thread for mounting the locking nut 5, and the axis of the fixing member 3 is provided with a passage 33;

[0042] 2) As shown in the upper left pattern of Fig. 3, the blow molding machine mold 9 is composed of left and right shells that can be opened and closed, the lower part of the mold 9 is provided with a liftable air needle 91, and the upper part of the mold 9 is provided with an extruder 92. Before the start of blow molding, as shown in the middle left pattern of Fig. 3, the fixing member 3 is installed on the air needle of the blow molding machine through the channel 33, and is arranged directly below the extruder;

[0043] 3) After the fixing member 3 is installed in place, as shown in the lower left pattern of Fig. 3, the extruder extrudes a cylindrical blank 93, and 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 requirements of mold closing;

[0044] 4) As shown in the upper right pattern of Fig. 3, after the length of the blank 93 meets the requirements of mold closing, the blow molding machine closes the mold, and the left and right shells are combined together. Then the air needle 91 blows air into the blank 93, so that the blank tightly adheres to the inner wall of the mold to form a blow molding inner liner 1;

[0045] 5) As shown in the middle right pattern of Fig. 3, after the blow molding inner liner 1 is formed, the air needle 91 is withdrawn from the mold, and is separated from the fixing member 3 and the blow molding inner liner;

[0046] 6) As shown in the lower right pattern of Fig. 3, after the air needle 91 is withdrawn, the blow molding machine opens the mold, and the left and right shells are separated. At this time, the blow molding inner liner 1 can be taken out, and the fixing member 3 remains in the inner cavity of the blow molding inner liner 1;

[0047] 7) A probe is used to stretch into the inner cavity of the blow molding inner liner from the opening of the blow molding inner liner to grab the fixing member 3 and pull the fixing member 3 to the opening of the blow molding inner liner; the probe is an elongated rod with external threads at the front end, and the external threads at the front end of the probe are adapted to the internal threads in the channel 33 of the fixing member 3. By screwing the threads at the front end of the probe into the internal threads of the fixing member 3, the fixing member 3 can be pulled to the opening of the blow molding inner liner 1 through the probe.

[0048] 8) An outer clamp 4 is sleeved on the opening of the blow molding inner liner, and a locking nut 5 is connected to the fixing member 3, to complete the assembly of the metal pipe mouth.

[0049] In addition, when used as a hydrogen storage cylinder, a carbon fiber layer can be wrapped around the outer wall of the blow molding inner liner 1 to further improve the pressure resistance. Industrial applicability

[0050] The contents not described in detail in the specification belong to the prior art known to those skilled in the art. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to part of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A blow molded high pressure liner with a pre-installed metal pipe mouth, comprising a blow molded liner (1) and a metal pipe mouth installed at the opening of the blow molded liner (1), wherein an axially extending neck (2) is arranged at the opening of the blow molded liner (1), the neck (2) is connected with the body (22) of the liner through a shoulder (21) to form an integrated whole, and the caliber of the neck (2) is smaller than that of the body (22), characterized in that: The metal pipe nozzle comprises a fixing part (3) coaxially installed inside the neck part (2), an outer clamp (4) sleeved outside the neck part (2), and a locking nut (5) threadedly connected to the fixing part (3); the inner end of the fixing part (3) is provided with a disc (31) clamped to the inner wall of the shoulder part (21), the outer end of the fixing part (3) extends out of the neck part (2) and is provided with an outer thread for installing the locking nut (5); the lower end of the outer clamp (4) cooperates with the disc (31) to form a clamping mechanism for the shoulder part (21) of the blow molding inner container (1), and the upper end of the outer clamp (4) abuts against the lower surface of the locking nut (5). ​ 2. The blow molded high pressure liner of claim 1, wherein: The fixing part (3) is a convolution, and a channel (33) communicating with the inner cavity of the blow molding inner container (1) is arranged at the axis of the fixing part (3); the outer end of the channel (33) is provided with an expanded section (32) having a diameter greater than that of the channel (33), and the expanded section (32) is provided with an inner thread.

3. The blow molded high pressure liner of claim 2, wherein: The channel (33) and the expanded section (32) are connected through a trumpet-shaped transition section.

4. The blow molded high pressure liner of claim 2, wherein: The channel (33) and the expanded section (32) are connected through a right-angle step.

5. The blow molded high pressure liner of pre-chucked metal pipe mouth 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 of pre-chucked metal pipe mouth according to claim 1 or 2, characterized in that: The outer contour of the outer clamp (4) is a conical structure with a large lower diameter and a small upper diameter, 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 central hole adapted to the neck part (2).

7. The blow molded high pressure liner of claim 6, wherein: The neck part (2) and the shoulder part (21) of the blow molding inner container (1) are connected through a circular arc transition, and the central hole and the bottom surface of the outer clamp (4) are connected through a circular arc transition.

8. Method for the production of blow-moulded high-pressure liners with pre- positioned metal spouts, characterised in that The method comprises the following steps: 1) preparing a metal pipe nozzle, which comprises a fixing part (3), an outer clamp (4), and a locking nut (5) threadedly connected to the fixing part (3); 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 part (2) and is provided with an outer thread for installing the locking nut (5), and a channel (33) is arranged at the axis of the fixing part (3); 2) installing the fixing part (3) on the air needle of a blow molding machine through the channel (33) and arranging it directly below an extruder; 3) extruding a cylindrical blank by the extruder, making the blank fall and be sleeved on the fixing part (3) and the air needle; 4) closing the mold, blowing air by the air needle, and making the blank form a blow molding inner container; 5) withdrawing the air needle from the mold; 6) demolding and taking out the blow molding inner container; 7) inserting a probe into the inner cavity of the blow molding inner container from the opening of the blow molding inner container to grab the fixing part (3) and pull the fixing part (3) to the opening of the blow molding inner container; 8) sleeving the outer clamp (4) at the opening of the blow molding inner container and connecting the locking nut (5) to the fixing part (3).

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