Composite high-pressure cylinder with improved sealing between metal nozzle boss and plastic liner joint

Abstract

The present invention relates to a composite material high-pressure vessel comprising a combination of a metal nozzle boss and a plastic liner, wherein the metal nozzle boss has a hollow formed inside in the longitudinal direction into which the nozzle is inserted, and both ends in the longitudinal direction are open, and is coupled to the plastic liner; the plastic liner includes a plastic liner protrusion that protrudes from at least one end in the longitudinal direction, has a through hole formed inside, and the metal nozzle boss is inserted and coupled to the outside of the through hole; the bushing, a portion of which is inserted into the through hole of the plastic liner protrusion and another portion disposed to be fitted between the metal nozzle boss and the plastic liner protrusion; and O-rings, a plurality of which are fitted to the outer surface of the bushing and spaced apart along the longitudinal direction between the inner surface of the plastic liner protrusion and the bushing to maintain airtightness between the plastic liner protrusion and the bushing, wherein the bushing comprises a bushing body portion having both ends open, a hollow formed inside, and an outer surface disposed to face the inner surface of the plastic liner protrusion, and both sides of the bushing body portion A composite material high-pressure vessel is provided, comprising a bushing flange portion that is integrally connected to the end of the bushing body portion which is positioned closer to the portion of the metal nozzle boss into which the nozzle is inserted, extends in a direction away from the center of the bushing body portion, and is positioned to be fitted between the plastic liner protrusion and the metal nozzle boss. Therefore, there is an advantage in that airtightness is improved because a sealing member is sandwiched between the inner surface of the plastic liner protrusion and the bushing inserted into the plastic liner protrusion.

Description

Technology Field

[0001] The present invention relates to a composite material high-pressure vessel with improved airtightness of the joint portion between a metal nozzle boss and a plastic liner, and more specifically, to a composite material high-pressure vessel with improved airtightness of the joint portion between a metal nozzle boss and a plastic liner in which a sealing member for improving airtightness is fitted between the inner surface of a plastic liner protrusion and a bushing inserted into the plastic liner protrusion. Background Technology

[0002] High-pressure vessels, such as fuel storage tanks for natural gas vehicles or hydrogen tanks for fuel cell vehicles, are manufactured by creating a liner using a polymer resin like high-density polyethylene (HDPE) to reduce weight, and then winding carbon fibers or glass fibers soaked in a curable polymer resin like epoxy resin over it. At this stage, a metallic nozzle boss is inserted at the end of the plastic liner to connect components such as regulators or valves.

[0003] Conventionally, linerboards were made from metallic materials and wound with carbon fibers or glass fibers soaked in curable polymer resin. However, recently, to reduce weight and shorten gas filling times, plastic liners made of high-density polyethylene are produced by injection molding or rotary molding, and then wound with carbon fibers or glass fibers soaked in epoxy resin or polyester resin. Composite material containers using metallic liners are heavy, highly susceptible to corrosion, and expensive to manufacture. On the other hand, composite material containers using plastic liners are lightweight, corrosion-resistant, resistant to repetitive filling fatigue, and have short gas filling times. For these reasons, the development of various composite material containers using plastic liners is currently actively underway.

[0004] However, when using plastic liners, airtightness becomes an issue because the plastic liner and the metallic nozzle boss do not seal completely. Therefore, it is necessary to develop a method that is simple yet can improve the airtightness between the plastic liner and the nozzle boss. Prior art literature

[0005] Republic of Korea Registered Patent No. 10-2449092 The problem to be solved

[0006] The present invention aims to provide a composite material high-pressure vessel with improved airtightness of a metal nozzle boss and a plastic liner joint portion, wherein a sealing member for improving airtightness is fitted between the inner surface of a plastic liner protrusion and a bushing inserted into the plastic liner protrusion. means of solving the problem

[0007] According to one aspect of the present invention, the present invention relates to a composite material high-pressure vessel comprising a combination of a metal nozzle boss and a plastic liner, wherein the metal nozzle boss has a hollow formed inside in a longitudinal direction into which a nozzle is inserted, and both ends in the longitudinal direction are open, and is coupled to the plastic liner; the plastic liner includes a plastic liner protrusion that protrudes from at least one end in the longitudinal direction, has a through hole formed inside, and the metal nozzle boss is inserted and coupled to the outside of the through hole; the bushing, a portion of which is inserted into the through hole of the plastic liner protrusion and another portion disposed to be fitted between the metal nozzle boss and the plastic liner protrusion; and O-rings, a plurality of which are fitted to the outer surface of the bushing and spaced apart along the longitudinal direction between the inner surface of the plastic liner protrusion and the bushing to maintain airtightness between the plastic liner protrusion and the bushing, wherein the bushing comprises a bushing body portion having both ends open, a hollow formed inside, and an outer surface disposed to face the inner surface of the plastic liner protrusion, and the A composite material high-pressure vessel is provided, comprising a bushing flange portion integrally connected to the end of the bushing body portion that is positioned closer to the portion of the metal nozzle boss into which the nozzle is inserted among the two ends of the bushing body portion, extending in a direction away from the center of the bushing body portion, and positioned to be fitted between the plastic liner protrusion and the metal nozzle boss. Effects of the invention

[0008] The composite material high-pressure vessel with improved airtightness of the joint between the metal nozzle boss and the plastic liner according to the present invention has the following effects.

[0009] First, there is an advantage in that airtightness is improved because a sealing member is sandwiched between the inner surface of the plastic liner protrusion and the bushing inserted into the plastic liner protrusion.

[0010] Second, since the sealing member only needs to be fitted onto the outer surface of the bushing, there is an advantage that even a worker without professional skills can easily install the sealing member.

[0011] Third, a bushing is inserted between the plastic liner protrusion and the nozzle boss, which has the advantage of preventing the plastic liner protrusion, whose rigidity is weakened by the thread formation, from collapsing. Brief explanation of the drawing

[0012] FIG. 1 is a schematic diagram showing a composite material high-pressure vessel with improved airtightness of the metal nozzle boss and plastic liner joint portion according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of a composite high-pressure vessel with improved airtightness of the metal nozzle boss and plastic liner joint portion according to FIG. 1. Figure 3 is a schematic diagram showing an enlarged view of the joint structure of a sealing member in a composite material high-pressure vessel with improved airtightness of the joint portion between the metal nozzle boss and the plastic liner according to Figure 1. FIG. 4 is a schematic diagram showing a nozzle (N) coupled to a composite material high-pressure vessel with improved airtightness of the metal nozzle boss and plastic liner coupling portion according to FIG. 1. Specific details for implementing the invention

[0013] The present invention will be described in detail below by explaining preferred embodiments of the invention with reference to the attached drawings.

[0014] Referring to FIGS. 1 to 4, a composite material high-pressure vessel (1000) according to one embodiment of the present invention has the advantage of excellent airtightness at the joint portion between the metal nozzle boss and the plastic liner. The composite material high-pressure vessel (1000) can be used to store hydrogen or compressed natural gas, etc., under high pressure. The composite material high-pressure vessel (1000) includes a metal nozzle boss (1100), a plastic liner (1200), a bushing (1300), an O-ring (1400), and a washer (1500).

[0015] The metal nozzle boss (1100) has a hollow formed inside in the longitudinal direction into which the nozzle (N) is inserted, and both ends in the longitudinal direction are open and are coupled with a plastic liner (1200). Specifically, the metal nozzle boss (1100) includes a nozzle boss center (1110) and a nozzle boss wing portion (1120) that are integrally connected.

[0016] The nozzle boss center (1110) has a hollow (hereinafter referred to as the "first hollow") formed inside in the longitudinal direction into which the nozzle (N) is inserted. Additionally, both ends of the nozzle boss center (1110) in the longitudinal direction are open. That is, the nozzle boss center (1110) is formed in a structure similar to a cylindrical tube.

[0017] In addition, screw threads are formed on the inner surface of the nozzle boss center (1110). This is for screw connection with the plastic liner protrusion (1210) described below. Also, screw threads are formed on the outer surface of the nozzle boss center (1110).

[0018] In this embodiment, the portion including the end into which the nozzle (N) is inserted among the two ends of the center of the nozzle boss (1110) is referred to as the upper portion of the metal nozzle boss (1100), and the portion including the opposite end is referred to as the lower portion of the metal nozzle boss (1100). The lower end of the upper portion of the metal nozzle boss (1100) and the upper end of the lower portion of the metal nozzle boss (1100) are integrally connected and have a structure that communicates. Furthermore, below, the portion closer to the end of the metal nozzle boss (1100) into which the nozzle (N) is inserted is referred to as the upper portion of the plastic liner (1200) and the bushing (1400), respectively, and the portion further away is referred to as the lower portion.

[0019] The hollow formed in the center of the nozzle boss (1110) has a stepped structure that extends uniformly from the top to the bottom and then widens in diameter. The upper part of the center of the nozzle boss (1110) forms a portion with a narrower diameter within the hollow formed in the center of the nozzle boss (1110). The lower part of the center of the nozzle boss (1110) forms a portion with a wider diameter within the hollow formed in the center of the nozzle boss (1110). That is, the metal nozzle boss (1100) has a structure in which the inner diameter of the lower part of the center of the nozzle boss (1110) is larger than the inner diameter of the upper part of the center of the nozzle boss (1110).

[0020] At this time, the lower end of the upper portion of the nozzle boss center (1110) rests on the bushing (1300) inserted into the plastic liner (1200). And the lower end of the lower portion of the nozzle boss center (1110) rests on the plastic liner body (1220) to be described below.

[0021] The nozzle boss wing portion (1120) is integrally connected to the lower outer surface of the nozzle boss center (1110) which is combined with the plastic liner (1200). The lower surface of the nozzle boss wing portion (1120) is seated on the plastic liner body portion (1220) to be described below. That is, the metal nozzle boss (1100) has a structure in which the lower portion of the nozzle boss center (1110) and the lower surface of the nozzle boss wing portion (1120) are each seated on the plastic liner body portion (1220).

[0022] The nozzle boss wing portion (1120) extends in a direction away from the nozzle boss center (1110). The nozzle boss wing portion (1120) is formed in the shape of a circular plate. However, the present invention is not limited thereto and the shape of the nozzle boss wing portion (1120) can be changed.

[0023] The plastic liner (1200) includes a plastic liner protrusion (1210) and a plastic liner body (1220) that are integrally connected. The plastic liner protrusion (1210) protrudes from at least one of the two ends in the longitudinal direction of the plastic liner (1200). In this embodiment, the plastic liner protrusion (1210) is formed on both ends in the longitudinal direction of the plastic liner (1200). However, the present invention is not limited thereto, and the plastic liner protrusion (1210) may be formed on only one of the two ends in the longitudinal direction of the plastic liner (1200).

[0024] And the plastic liner protrusion (1210) has a through hole formed inside. That is, the plastic liner protrusion (1210) has a structure similar to a cylindrical tube overall.

[0025] And the plastic liner protrusion (1210) is formed in a structure in which a metal nozzle boss (1100) is inserted and coupled to the outside of a through hole formed inside the plastic liner protrusion (1210). Specifically, the screw threads formed on the inner circumference of the nozzle boss center (1110) and the screw threads formed on the outer circumference of the plastic liner protrusion (1210) are coupled complementarily, thereby screw-coupled the plastic liner protrusion (1210) and the nozzle boss center (1110).

[0026] The plastic liner body (1220) extends outward from the plastic liner protrusion (1210) so that the nozzle boss center (1110) and the nozzle boss wing (1120) can be seated on the outer (upper) side. Additionally, a groove (1220a) is formed in the extended portion of the plastic liner body (1220) so that the nozzle boss wing (1120) can be seated thereon.

[0027] The depth of the extended end of the groove (1220a) is formed to be equal to the thickness of the extended end of the nozzle boss wing (1120). That is, when the nozzle boss wing (1120) is seated in the groove (1220a), the upper surface of the plastic liner body (1220) in contact with the extended end of the groove (1220a) forms a smooth surface with no step difference from the extended end of the nozzle boss wing (1120). Through this, the outer surface of the plastic liner body (1220) and the outer surface of the nozzle boss wing (1120) form a structure that is the same as the outer surface of a single object.

[0028] A bushing (1300) is installed to prevent the threaded portion of the plastic liner protrusion (1210) from being sunken (damaged) when the metal nozzle boss (1100) and the plastic liner protrusion (1210) are joined. A portion of the bushing (1300) is inserted into the through hole of the plastic liner protrusion (1210), and another portion is positioned to be sandwiched between the metal nozzle boss (1100) and the plastic liner protrusion (1210). Specifically, the bushing (1300) includes a bushing body portion (1310) and a bushing flange portion (1320) that are integrally connected.

[0029] The bushing body (1310) has a cylindrical tube structure with both ends open and a hollow formed inside. The bushing body (1310) is inserted (fitted) so that its outer surface faces the inner surface of the inner diameter portion of the plastic liner protrusion (1210) while in close contact.

[0030] In addition, a plurality of bushing grooves are formed on the outer surface of the bushing body (1310) so that the O-ring (1400) can be stably fixed when fitted. In this embodiment, a first bushing groove (1300a), a second bushing groove (1300b), and a third bushing groove (1300c) are formed in the bushing body (1310). The first bushing groove (1300a), the second bushing groove (1300b), and the third bushing groove (1300c) are formed spaced apart in the longitudinal direction (up and down direction) of the bushing body (1310). In this embodiment, the spaced length between the first bushing groove (1300a) and the second bushing groove (1300b) and the spaced length between the second bushing groove (1300b) and the third bushing groove (1300c) are formed to be the same. However, the present invention is not limited thereto and the number and spacing of the bushing grooves can be changed.

[0031] The bushing flange portion (1320) has a circular ring structure with a through hole formed in the center. The bushing flange portion (1320) is integrally connected to the end of the bushing body portion (1310) that is positioned closer to the part (one end) of the metal nozzle boss (1100) into which the nozzle (N) is inserted, among the two ends of the bushing body portion (1310).

[0032] And the bushing flange portion (1320) extends in a direction away from the center of the bushing body portion (1310). At this time, the bushing flange portion (1320) is seated and closely attached to the upper part of the plastic liner protrusion (1210).

[0033] That is, the bushing flange portion (1320) has a structure in which, when the inner diameter is the same as the inner diameter of the bushing body portion (1310), the lower portion is seated on the upper portion of the bushing body portion (1310) and connected integrally, and when the inner diameter is larger than the inner diameter of the bushing body portion (1310), the outer surface portion faces the upper outer surface portion of the bushing body portion (1310) and is connected integrally.

[0034] And when the inner diameter of the bushing flange portion (1320) is the same as the inner diameter of the bushing body portion (1310), a step structure is formed on the upper portion of the bushing flange portion (1320). That is, when the inner diameter of the bushing flange portion (1320) is the same as the inner diameter of the bushing body portion (1310), the part of the bushing flange portion (1320) connected to the bushing body portion (1310) (hereinafter referred to as the "first part") has a structure that protrudes upward from the part of the bushing flange portion (1320) that is seated on the upper portion of the plastic liner protrusion (1210) (hereinafter referred to as the "second part"). At this time, the washer (1500) described below has its lower surface seated on the second part and its inner surface in close contact with the outer surface of the first part. At this time, the thickness of the washer (1500) is greater than the length protruding upward from the first part, so that the first part and the lower part of the upper portion of the metal nozzle boss (1100) are spaced apart.

[0035] And when the inner diameter of the bushing flange portion (1320) is larger than the inner diameter of the bushing body portion (1310), a step structure is not formed in the bushing flange portion (1320) itself, but a step structure is formed between the bushing flange portion (1320) and the bushing body portion (1310). In this case, the bushing flange portion (1320) is seated on the upper part of the plastic liner protrusion (1210), and the washer (1500) is seated on the bushing flange portion (1320). And the upper part of the bushing body portion (1310) is positioned to be spaced apart from the lower part of the upper part of the metal nozzle boss (1100).

[0036] And the bushing flange portion (1320) is positioned to be fitted between the plastic liner protrusion (1210) and the metal nozzle boss (1100). Being positioned so that the bushing flange portion (1320) is fitted between the plastic liner protrusion (1210) and the metal nozzle boss (1100) means that the bushing flange portion (1320) is seated on the upper part of the plastic liner protrusion (1210), and the lower part of the upper part of the nozzle boss center (1110) is seated on the bushing flange portion (1320) and is in close contact with it. Of course, in this embodiment, since a washer (1500) is positioned between the bushing flange portion (1320) and the lower part of the upper part of the nozzle boss center (1110), the bushing flange portion (1320) has a structure in which the lower surface of the washer (1500) is seated on the bushing flange portion (1320) and is in close contact with it.

[0037] The bushing (1300) is exemplified as being formed from a metal material. However, the present invention is not limited thereto, and the bushing (1400) can be changed to a hard plastic material.

[0038] An O-ring (1400) is installed to maintain airtightness between the plastic liner protrusion (1210) and the bushing (1300). The O-ring (1400) is fitted onto the outer surface of the bushing (1300) and positioned between the inner surface of the plastic liner protrusion (1210) and the bushing (1400). The inner side of the O-ring (1400) is in close contact with the outer surface of the bushing body (1310), and the outer side is in close contact with the inner surface of the plastic liner protrusion (1210).

[0039] A plurality of O-rings (1400) are arranged spaced apart along the length direction on the outer surface of the bushing (1300). Specifically, a plurality of O-rings (1400) are arranged spaced apart along the length direction on the outer surface of the bushing body (1310).

[0040] In this embodiment, the O-ring (1400) includes a first O-ring (1410), a second O-ring (1420), and a third O-ring (1430). The first O-ring (1410) is fitted into the first bushing groove (1300a), the second O-ring (1420) is fitted into the second bushing groove (1300b), and the third O-ring (1430) is fitted into the third bushing groove (1300c). The distance between the first O-ring (1410) and the second O-ring (1420) and the distance between the second O-ring (1420) and the third O-ring (1430) are formed to be the same. However, the present invention is not limited thereto, and the number of O-rings (1400) and the spacing between them can be changed.

[0041] And each of the first O-ring (1410), the second O-ring (1420), and the third O-ring (1430) forms a flat surface with the outer surface of the bushing body (1310) while being fitted into the first bushing groove (1300a), the second bushing groove (1300b), and the third bushing groove (1300c), respectively. That is, the outer surface of each of the first O-ring (1410), the second O-ring (1420), and the third O-ring (1430) forms a flat surface along the longitudinal direction (up and down direction) of the bushing body (1310) and the portion of the outer surface of the bushing body (1310) where the first bushing groove (1300a), the second bushing groove (1300b), and the third bushing groove (1300c) are not formed.

[0042] A washer (1500) is positioned between the bushing (1300) and the metal nozzle boss (1100). Specifically, the washer (1500) is positioned to be seated on the bushing flange portion (1320). That is, the lower surface of the washer (1500) is positioned to be in close contact with the upper surface of the bushing flange portion (1320), and the upper surface of the washer (1500) is positioned to be in close contact with the lower end of the upper portion of the metal nozzle center (1110). At this time, the washer (1500) has a circular ring structure. In this embodiment, the inclusion of the washer (1500) is used as an example, but the washer (1500) may not be included.

[0043] The present invention has been described with reference to the embodiments illustrated in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims. Explanation of the symbols

[0044] 1000: Composite material high-pressure vessel 1100: Metal nozzle boss 1110: Nozzle boss center 1120: Nozzle boss wing 1200: Plastic liner 1210: Plastic liner protrusion 1220: Plastic liner body 1220a: Plastic liner groove 1300: Bushing 1300a: 1st bushing groove 1300b: 1st bushing groove 1300c: 1st bushing groove 1310: Bushing body 1320: Bushing flange section 1400: O-ring 1410: 1st O-ring 1420: 2nd O-ring 1430: 3rd O-ring 1500: Washer N: Nozzle

Claims

Claim 1 A composite material high-pressure vessel comprising a combination of a metal nozzle boss and a plastic liner, wherein the metal nozzle boss has a hollow formed inside in the longitudinal direction into which the nozzle is inserted, and both ends in the longitudinal direction are open, and is coupled to the plastic liner; a plastic liner including a plastic liner protrusion that protrudes from at least one end in the longitudinal direction, has a through hole formed inside, and the metal nozzle boss is inserted and coupled to the outside of the through hole; a bushing, wherein a portion is inserted into the through hole of the plastic liner protrusion and another portion is positioned to be sandwiched between the metal nozzle boss and the plastic liner protrusion; and, for maintaining airtightness between the plastic liner protrusion and the bushing, a plurality of O-rings are fitted onto the outer surface of the bushing and spaced apart along the longitudinal direction between the inner surface of the plastic liner protrusion and the bushing, wherein the bushing comprises a bushing body portion having both ends open, a hollow formed inside, and an outer surface positioned to face the inner surface of the plastic liner protrusion. A composite material high-pressure vessel comprising a bushing flange portion integrally connected to the end of the bushing body portion that is positioned closer to the portion of the metal nozzle boss into which the nozzle is inserted among the two ends of the bushing body portion, extending in a direction away from the center of the bushing body portion, and positioned to be fitted between the plastic liner protrusion and the metal nozzle boss. Claim 2 A composite material high-pressure container according to claim 1, wherein the inner side of the O-ring is in close contact with the outer circumference of the bushing body part and the outer side is in close contact with the inner circumference of the plastic liner protrusion part. Claim 3 A composite material high-pressure vessel according to claim 1, wherein a screw thread is formed on the inner surface of the metal nozzle boss and a screw thread capable of being coupled complementarily to the screw thread formed on the metal nozzle boss is formed on the outer surface of the plastic liner protrusion, so that the metal nozzle boss and the plastic liner protrusion are screw-coupled. Claim 4 In claim 1, the bushing is a composite material high-pressure vessel formed of metal or a hard plastic material.

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