KR20130039877A - Gas tank and manufacturing method of the same - Google Patents

Abstract

PURPOSE: A gas tank and a manufacturing method thereof are provided to improve the formability and rigidity of each floor by coupling an intermediate fiber layer to a liner. CONSTITUTION: A gas tank comprises an intermediate fiber layer(200), a surface resin layer(300), and a synthetic resin liner(100). The intermediate fiber layer is formed by winding a filament member containing glass fiber or carbon fiber. The surface resin layer is laminated on the intermediate fiber layer. The synthetic resin liner accommodates gas. The filament member is wound on the exterior of the liner.

Description

GAS TANK AND MANUFACTURING METHOD OF THE SAME

The present invention relates to a gas tank for storing high pressure gas for use in automobiles or other industrial fuels and a method of manufacturing the same.

Gas tanks for storing high pressure gas for fuel require high rigidity, corrosion resistance, fatigue resistance, light weight, and the like to withstand high pressure. When the gas tank is mounted in a transport engine such as a car, the problem of weight reduction along with securing high strength for safety is a big issue. In the case of a gas tank made of a metal material, there is an advantage in that high strength is secured, but there are problems in that the load is heavy and the corrosion resistance is weak. Korean Patent Publication No. 1988-0002730 describes a pressure vessel having an improved side wall structure.

The present invention provides a gas tank made of a composite material in order to achieve weight reduction with high strength. In order to withstand high pressure, the gas tank of the present invention has a triple structure including a composite material.

In one embodiment, the gas tank of the present invention comprises an intermediate fiber layer formed by winding a filament member comprising glass fibers or carbon fibers; A surface resin layer laminated on the intermediate fiber layer; .

In one embodiment, the gas tank of the present invention, the liner is accommodated gas; An intermediate fiber layer having a filament member wound on a surface of the liner; A surface resin layer laminated on the intermediate fiber layer; And a high pressure liquid resin is injected into the outer circumference of the intermediate fiber layer and high pressure air is injected into the liner to form the surface resin layer.

In one embodiment, the method of manufacturing a gas tank of the present invention comprises the steps of: forming a liner containing gas; Winding the filament member in a dry state to the liner to form an intermediate fiber layer; Injecting a liquid resin at high pressure into the intermediate fiber layer and injecting high pressure air into the liner to form a surface resin layer; .

Winding with only the filament member is inferior in formability or strength. The present invention uses the liner as the base skeleton and winds the filament member thereon to form an intermediate fiber layer. Accordingly, the formability and strength of each layer are improved as compared to the method of winding the filament member to bond the first completed intermediate fiber layer to the liner.

Since the present invention uses a liner as a winding frame to wind a dry filament member on the liner, a filament member having a low friction coefficient, which is poorly coagulated with each other and hardly maintains a constant shape, can be accurately formed into a gas tank shape. .

The surface resin layer disposed on the intermediate fiber layer is high-pressure laminated with a thermosetting resin to form a gas tank having a triple structure as a whole, so that occurrence of surface cracks is suppressed and impact resistance and wear resistance are improved.

1 is a partial cross-sectional view showing a triple structure of a gas tank of the present invention.
Figure 2 shows, as one embodiment of the invention, a liner with a fusion.
3 illustrates a liner manufactured by blow molding as an embodiment of the present invention.
4 to 6 illustrate a winding method of a filament member as an embodiment of the present invention.
7 is for comparison with the dry winding of the present invention, is a cross-sectional photograph illustrating the generation of voids when the filament member is impregnated in the resin and wet winding.
8 is a cross-sectional view illustrating a resin lamination process as an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The sizes and shapes of the components shown in the drawings may be exaggerated for clarity and convenience. In addition, terms defined in consideration of the configuration and operation of the present invention may be changed according to the intention or custom of the user, the operator. Definitions of these terms should be based on the content of this specification.

1 is a partial cross-sectional view showing a triple structure of a gas tank of the present invention. Referring to this, the gas tank of the present invention includes a liner 100 in which gas is received, an intermediate fiber layer 200 formed by winding the filament member 210 on an outer surface of the liner 100, and an intermediate It consists of a triple structure including the surface resin layer 300 stacked on the fiber layer 200.

When winding with only the filament member 210, the formability or strength is poor. The present invention uses the liner 100 as a basic skeleton to wind the filament member 210 therein to form the intermediate fiber layer 200. Therefore, the formability and strength of each layer are improved as compared to the method of winding the filament member 210 to bond the first intermediate fiber layer 200 to the liner 100. The liner 100 functions as a mandrel when the intermediate fiber layer 200 is formed. When the filament member 210 is formed on the liner 100 using the liner 100 as a mandrel as in the present invention, the intermediate fiber layer 200 is wound using the liner 100 as a guide member, thereby forming the intermediate fiber layer 200. It is improved in strength and strength.

In addition, the present invention is a dry winding in which the filament member 210 is wound in the liner 100 in a dry state not impregnated with the liquid resin when the intermediate fiber layer 200 is formed. Since the present invention uses the liner 100 as a winding frame to wind the filament member 210 in a dry state on the liner 100, the filament member having a low friction coefficient has a low cohesion property and is difficult to maintain a constant shape by itself. 210 can be molded into a gas tank shape.

The surface resin layer 300 is formed on the liner 100 and the intermediate fiber layer 200 to form an appearance of the gas tank. The surface resin layer 300 is laminated on the outer surface of the intermediate fiber layer 200 with a mold to enhance the surface strength and corrosion resistance of the gas tank. In one embodiment, the mold for forming the surface resin layer 300 is preferably a resin transfer molding (RTM) mold. Since the surface resin layer 300 disposed on the intermediate fiber layer 200 is laminated with a thermosetting resin to form a gas tank having a triple structure as a whole, surface cracking is suppressed and impact resistance and abrasion resistance are improved.

Compared to a conventional gas tank made of metal, the gas tank of the present invention is made of a filament member 210 including synthetic resin, glass fiber, or carbon fiber, so that corrosion may occur inside the gas tank. There is no concern and there is no fear of foreign substances such as rust or metal debris.

Hereinafter, the liner 100, the intermediate fiber layer 200, and the surface resin layer 300 will be described in order.

2 illustrates a liner 100 having a fusion 124 as one embodiment of the present invention. 3 illustrates a liner 100 manufactured by blow molding as an embodiment of the present invention.

The liner 100 is preferably molded of a thermoplastic resin which prevents leakage of gas, has low reactivity with the gas, and has good adhesion. The liner 100 is made of thermoplastic resin including polyethylene (PE) and high density polyethylene (HDPE).

The liner 100 is manufactured by the first method or the second method. The first method illustrated in FIG. 2 is a fusion method in which the dome part 110, the cylinder part 120, and the boss part 130 are joined by ultrasonic fusion or thermal fusion at each interface. The fusion unit 124 is formed at the interface between the dome unit 110, the cylinder unit 120, and the boss unit 130.

The dome part 110 has a dome shape which closes both openings 122 of the cylinder part 120.

Gas is accommodated in the cylinder portion 120, the cylinder portion 120 is a pipe shape, both ends of the dome portion 110 is coupled, the center portion 122 is formed with an opening 122 is fitted.

The boss portion 130 is a gas passage and includes a metal base portion 132, which is a portion on which a pump or a valve is mounted, and a resin bonding portion 134 made of a synthetic resin material bonded to the cylinder portion 120. The valve or the pump for controlling the flow rate of the gas to the metal base portion 132 should be fastened by bolts or welding, and the deformation resistance should be higher than that of the other parts, and thus made of a metal material. Since the resin bonding portion 134 should have good adhesion with the cylinder portion 120, the resin bonding portion 134 is made of a thermoplastic resin that is the same material as the liner 100.

In one embodiment, the insert mold 410 is formed by inserting a metal base portion 132 on which a pump or a valve is mounted together with an insert mold 410 into which a thermoplastic resin, which is a material of the resin joint portion 134, is injected. The boss portion 130 is provided.

According to the fusion method, when adjusting the capacity of the gas tank, the dome part 110 can be easily changed by using the one manufactured as the existing dimension and adjusting only the length of the cylinder part 120. Also, in the case of fusion method, it is advantageous in terms of parts supply and exchange since only the defective part is removed and replaced with a regular product.

Since the fusion portion 124 is bonded by ultrasonic fusion or thermal fusion, it is preferable to form the liner 100 with a thermoplastic resin having excellent bonding property. The boss unit 130 is not molded at one time in the blow mold 420 but is bonded to the liner 100 as a separate component even by the second method described later, so that the liner 100 is made of a thermoplastic resin having good adhesion. To make.

In the second method of forming the liner 100 illustrated in FIG. 3, the liner base 151 is inserted into the blow mold 420 and blows air into the liner base 151 to thereby form the liner base 151. 100) It is a blow molding method expanded to a shape. The air injected through the blow holes expands the inside of the liner base 151, and the outside of the liner base 151 is in close contact with the blow mold 420 and is molded into the same shape as the inside of the mold. In the liner 100 passing through the blow mold 420, the opening 122 is processed in a post-processing process, and the boss 130 provided by insert injection or other methods is fused to the opening 122.

4 to 6 illustrate a winding method of the filament member 210 as an embodiment of the present invention. FIG. 7 is a cross-sectional view illustrating the generation of voids 290 when the filament member 210 is impregnated with a resin and wet-wound as a comparison with the dry winding of the present invention.

The intermediate fiber layer 200 is a dry winding of the filament member 210 including glass fibers or carbon fibers.

In comparison with the present invention, when the composite material is produced by the wet fiber winding method, the fiber is impregnated with the resin, and the fiber in the wet state is wound to form a tank. However, the fibers impregnated with the resin are viscous and viscous, and the shape reproducibility is poor because the probability of maintaining the same position and the same thickness during repeated molding is low. In addition, when the fiber is wound in a wet state impregnated with the resin, process management is difficult, resulting in a decrease in productivity and production yield, and inferior quality uniformity. The wet fiber winding has a high incidence of voids 290, as shown in FIG. Foreign matter or impurities are mixed in the filament member 210, the yield is reduced, the uniformity of the shape is deteriorated, the air holes are bundled due to the liquid resin on the filament member 210, there is a problem that the strength is lowered.

The present invention improves this to wind the filament member 210 on the surface of the liner 100 in a dry state without impregnating the resin in the filament member 210. Forming the intermediate fiber layer 200 by the dry filament winding has the advantage of shortening the production yield and production time, improving the porosity to reduce the bubble content and improve the strength. According to the dry winding, the winding time is reduced and the production yield is improved, and the handling of the filament member 210 is easy and the foreign matter does not stick to the filament member 210, thereby improving the quality uniformity.

In the graph where the x-axis is the strain and the y-axis is the tensile strength, the filament member 210 is a straight or curved line having a much larger slope than the synthetic resin forming the surface resin layer 300. appear. That is, the filament member 210 including glass fibers or carbon fibers has a tensile strength much higher than that of the surface resin layer 300 for the same strain. On the other hand, the synthetic resin forming the surface resin layer 300 has a much higher strain rate than the filament member 210 for the same tensile strength.

Therefore, the synthetic resin forming the liner 100 or the surface resin layer 300 has a smaller tensile strength than the filament member 210, but absorbs energy until the material breaks, so the toughness is good and excellent. It has the characteristics of aging deterioration, is resistant to environmental degradation such as ultraviolet rays, and is resistant to repeated fatigue loads.

The intermediate fiber layer 200 complements the tensile strength of the liner 100 or the surface resin layer 300. The intermediate fiber layer 200 made of the filament member 210 may be formed of the resin liner 100 disposed inside the intermediate fiber layer 200 as well as the surface resin layer 300 disposed outside the intermediate fiber layer 200. Intensively improve strain properties and tensile strength. The surface tension and deformation resistance of the intermediate fiber layer 200, the liner 100, and the surface resin layer 300 are improved.

The gas tank of the present invention is formed by combining the properties of the resin forming the liner 100 or the surface resin layer 300 and the properties of the filament member 210 forming the intermediate fiber layer 200. The strength of the gas tank varies according to the winding ratio of the filament member 210 as well as the relative ratio of the resin forming the liner 100 or the surface resin layer 300 to the filament member 210.

4 illustrates an embodiment in which the filament member 210 is wound along the axial direction of the liner 100. The filament member 210 extends in a direction parallel to the axial direction with an angle of 0 ° in the cylinder part 120, and an inclination angle θ with the axial direction in the dome part 110 is 0 to 90 °. The dome part 110 or the boundary surface between the dome part 110 and the cylinder part 120 is wound to form a predetermined inclination angle θ with respect to the axial direction of the cylinder part 120.

The cylinder part 120 has a constant diameter, but the dome part 110 has a diameter of the inner circumferential portion smaller than that of the outer circumferential portion. Therefore, when winding the filament member 210 having a constant thickness to the dome part 110 via the cylinder part 120, a problem arises in that the stacking thickness of the filament member 210 becomes larger toward the center portion of the dome part 110. As an embodiment for improving this, the inclination angle of the filament member 210 in the dome 110 has a different value depending on the number of turns of the filament member 210. Accordingly, the thickness of the intermediate fiber layer 200 of the cylinder part 120 and the thickness of the intermediate fiber layer 200 of the dome part 110 are uniformly wound.

As an example, referring to FIG. 4, among the filament members 210 extending in parallel in the cylinder portion 120, the first fibers 210a and the second fibers 210b adjacent to each other are in the dome portion 110 region. Different angles of inclination extend in different directions. Therefore, it is possible to prevent the specific region of the dome portion 110 from becoming thick.

FIG. 5 illustrates an embodiment in which the fiber bundles 220 are wound in a zigzag in a straight line along a first direction inclined in the axial direction of the cylinder part 120, and the fiber bundles 220 are alternately wound in a zigzag. Indicates. The fiber bundle 220 includes a plurality of filament members 210 extending in parallel. When the fiber bundle 220 is wound in the shape as shown in FIG. 5, there is no sudden change in the inclination angle at the boundary between the dome part 110 and the cylinder part 120, and thus the winding thickness difference between the cylinder part 120 and the dome part 110 is different. Reduced has the advantage of uniform strength reinforcement characteristics.

FIG. 6 is a hoop shape in which the fiber bundle 220 is wound in a zigzag shape on the dome part 110 and is zigzag-shaped, and the cylinder part 120 extends along the circumferential direction of the cylinder part 120. An example of winding is shown. As the number of turns of the fiber bundle 220 increases, the winding of the dome part 110 is completed to form the primary winding part 221, the inclination angle of the fiber bundle 220 is changed, and then the cylinder part 120 is changed. Winding to form a hoop to form a secondary winding part 222.

The primary winding part 221 in which the fiber bundle 220 is wound in a zigzag shape is in close contact with the liner 100, and the fiber bundle 220 has a hoop shape extending along the circumferential direction of the cylinder part 120. The secondary winding 222 wound around the 220 is in close contact with the primary winding 221. According to this, the thickness of the fiber bundle 220 of the dome part 110 and the cylinder part 120 can be uniform, and the radial and tangential direction strains of the cylinder part 120 are concentrated and reinforced. have.

In the embodiment of the present invention shown in Figures 4 to 6, the filament member 210 is a dry winding, so the adhesion of the liner 100 surface and the filament member 210 is low. The low tack of dry windings reduces the winding time by about 50% compared to wet windings and offers advantages in shape reproducibility, foreign matter prevention and uniformity. However, the low adhesion of dry windings is a factor in sliding the filament member 210 on the surface of the liner 100 during winding.

In order to improve this, the hook 152 is preferably provided. The hook 152 protrudes on the outer circumference of the liner 100 and spans the filament member 210 or the fiber bundle 220 to change the winding direction of the filament member 210 or the fiber bundle 220. The hook 152 is provided at a position where the inclination angle of the filament member 210 or the fiber bundle 220 is discontinuously fluctuated and prevents the sliding flow of the filament member 210.

In an embodiment, the hook 152 may be provided at the inclined portions of the dome part 110 and the cylinder part 120 to maximize the anti-slip effect of the filament member 210. The filament member 210 may be caught by the hook 152 to prevent flow, and may achieve a sharp change in the inclination angle at the boundary portion between the dome 110 and the cylinder 120.

8 is a cross-sectional view illustrating a process of forming the surface resin layer 300 as an embodiment of the present invention.

The surface resin layer 300 is a thermosetting resin including an epoxy and a vinyl ester is laminated at high pressure on the outer circumferential surface of the intermediate fiber layer 200 using the RTM mold 430.

Epoxy resin has a specific gravity of 1.230 to 1.189 and is excellent in mechanical properties such as bending strength and hardness. There is no generation of volatiles and shrinkage of the volume at the time of curing, and it has great adhesion to the material surface. By adding a pigment, coloring can be made at will, the sun resistance is also good, and moldability and encapsulation workability are very excellent. Therefore, it is good as a joining material between a metal and a metal, as well as a heterogeneous material. In the case of the annular die epoxy resin, the heat resistance is also improved and has heat resistance up to around 180 ° C.

Vinyl ester is obtained by pressurizing acetylene and fatty acid as vinyl alcohol ester. Vinyl esters include carboxylic acid esters (formula RCOOCH = CH2) and also include inorganic acid esters. Pressurizing acetylene and fatty acids and reacting with a zinc salt as a catalyst produces vinyl esters. When radical polymerization occurs on the vinyl ester and the polymer is reacted, polyvinyl ester, vinyl hybrid polymer, and polyvinyl alcohol are produced.

When the intermediate fiber layer 200 is formed on the liner 100 and the fusion of the boss 130 is completed, the surface resin layer 300 is laminated as a final process. At this time, the surface resin layer 300 is laminated at high pressure to improve the strength of the surface resin layer 300. When the surface resin layer 300 is formed, the high pressure liquid resin is injected into the outer circumference of the intermediate fiber layer 200 through the resin injection hole 432, and the liner 100 is prevented from being deformed according to the injection pressure of the liquid resin. In order to do this, air having a pressure equal to the injection pressure of the liquid resin is injected into the liner 100 through the air injection unit 422.

The air inlet 422 is formed by opening a portion of the RTM mold 430. In an embodiment, the boss 130 is brought into close contact with the air injection unit 422 so that air does not leak into a gap between the boss unit 130 and the air injection unit 422, and the gas formed in the boss unit 130 is provided. Air is injected into the liner 100 through the hole 133 and the opening 122 of the liner 100.

When the surface resin layer 300 is formed at high pressure under the condition that the deformation of the liner 100 is prevented by air injection, the void 290 occurrence rate is reduced and the bonding force between the intermediate fiber layer 200 and the surface resin layer 300 is improved. do. The surface resin layer 300 formed by resin injection is first hardened or second hardened in the mold or taken out from the mold.

The injection pressure of the liquid resin through the resin injection hole 432 or the injection pressure of air through the air injection portion 422 is 30 Bar or more. The liquid resin constituting the surface resin layer 300 is injected into the mold at a pressure of 30 Bar or more, and forms a stabilized polymer ring through a first curing step for 10 to 20 minutes at a high temperature of 80 ° C. or higher. After the primary curing step it is secondary cured, such as by natural cooling.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, the true scope of the present invention should be determined by the following claims.

100 ... liner 151 ... liner base
152 Hook 200 Intermediate fiber layer
210 filament member 220 fiber bundle
221 ... 1st winding part 222 ... 2nd winding part
290 voids 300 resin surface
110.Dome 120 Cylinder
122 ... opening 124 ... fusion part
130 Boss part 132 Metal base part
133.Gas hole 134 ... Resin junction
410 insert mold 420 blow mold
422 ... Air injection 430 ... RTM mold
432 ... Resin inlet

Claims (19)

An intermediate fiber layer formed by winding a filament member comprising glass fibers or carbon fibers;
A surface resin layer laminated on the intermediate fiber layer; Gas tank comprising a. The method of claim 1,
A liner made of synthetic resin containing gas; Lt; / RTI >
A gas tank in which the filament member is wound on an outer surface of the liner. The method of claim 2,
And the filament member is wound in the liner in a dry state. The method of claim 2,
The liner is made of polyethylene, thermoplastic resin including high density polyethylene,
The surface resin layer is a gas tank made of a thermosetting resin containing epoxy, vinyl ester (vinyl ester). The method of claim 2,
The liner includes a pipe-shaped cylinder portion in which gas is accommodated, a boss portion inserted into an opening of the cylinder portion, and a dome portion closing both ends of the cylinder portion. The method of claim 5,
A gas tank in which a fusion portion for fusion bonding the dome portion, the cylinder portion, and the boss portion to each other is provided at an interface between the dome portion, the cylinder portion, and the boss portion. The method of claim 5,
A liner base is inserted into a blow mold and blows air into the liner base to expand the liner base into the liner shape,
And a filament member wound around the liner taken out of the blow mold. The method of claim 5,
The boss portion is a gas tank including a metal base portion which is a passage for the gas and the pump or valve is mounted and a resin bonding portion of a synthetic resin material bonded to the cylinder portion. 9. The method of claim 8,
And the boss portion is provided by insert molding for inserting and inserting the metal base portion into an insert mold into which the material of the resin bonding portion is injected. The method of claim 1,
Wherein the filament member has a higher tensile strength than the surface resin layer for the same strain, and the surface resin layer has a higher strain than the filament member for the same tensile strength. The method of claim 1,
A liner including a dome portion and a cylinder portion, to which the filament member is wound, is provided,
The filament member is wound along the axial direction of the liner,
The filament member extends in a direction parallel to the axial direction at an angle of 0 ° to the axial direction in the cylinder part, and an inclination angle θ of the dome part to the axial direction is 0 to 90 ° in the dome part or And a gas tank wound at an interface between the dome portion and the cylinder portion at a predetermined inclination angle θ. The method of claim 1,
And a liner including a dome portion and a cylinder portion, to which the filament member is wound, wherein the inclination angle of the filament member in the dome portion has a different value according to the number of turns of the filament member. The method of claim 1,
A liner including a dome portion and a cylinder portion and having a winding of the filament member is provided, wherein the first and second fibers adjacent to each other among the filament members extending in parallel from the cylinder portion have different inclination angles in the dome region and are different from each other. Tank extending in the direction. The method of claim 1,
A liner including a dome portion and a cylinder portion and to which the filament member is wound is provided, the fiber bundle including a plurality of filament members extending in parallel extends linearly along a first direction inclined in the axial direction of the cylinder portion, A gas tank in which each bundle of fibers is staggeredly wound in a zigzag. The method of claim 1,
A liner including a dome part and a cylinder part and the filament member is wound is provided, and a primary winding part is formed by completing a zigzag winding of the dome part by increasing the number of turns of the fiber bundle, and changing an inclination angle of the fiber bundle. After the second gas is formed by winding the cylinder portion in the shape of a hoop. A liner containing gas;
An intermediate fiber layer having a filament member wound on a surface of the liner;
A surface resin layer laminated on the intermediate fiber layer; / RTI >
A gas tank in which the surface resin layer is formed by injecting high pressure liquid resin into the outer circumference of the intermediate fiber layer and injecting high pressure air into the liner. 17. The method of claim 16,
An injection pressure of the liquid resin or an injection pressure of the air is at least 30 Bar. 17. The method of claim 16,
Wherein the liquid resin is a gas tank which is subjected to a first curing step for 10 to 20 minutes at a high temperature of at least 80 ℃ to form a stabilized polymer ring, secondary curing by natural cooling after the first curing. Forming a liner containing gas;
Winding the filament member in a dry state to the liner to form an intermediate fiber layer;
Injecting a liquid resin at high pressure into the intermediate fiber layer and injecting high pressure air into the liner to form a surface resin layer; Gas tank manufacturing method comprising a.

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