Pressure vessel structure

Abstract

The present invention provides a pressure vessel structure that can improve flow turbulence during molding and reduce plastic strain. [Solution] The cylindrical synthetic resin liner having a storage section inside comprises a dome section 4 on which a nozzle is installed at the axial end L, a groove section 10 formed in a concave shape in the radial center of the dome section 4 on which the nozzle 6 is installed, and a locking section 12 that protrudes from the connection section 11 between the dome section 4 and the groove section 10 and locks the nozzle 6. The locking section 12 has a first wall section 13 extending radially D towards the center from the dome section 4, a second wall section 14 extending axially L outward from the groove section 10, and a top section 15 where the first wall section 13 and the second wall section 14 meet. The thickness of the first wall section 13 and the second wall section 14 increases towards the top section 15. Furthermore, a weight-reducing section 16 is provided on the back side of the top section 15.

Description

Technical Field

[0001] The present invention relates to a pressure vessel structure.

Background Art

[0002] In recent years, research and development on fuel cells that contribute to energy efficiency have been carried out to enable more people to access affordable, reliable, sustainable, and advanced energy. Conventionally, a pressure vessel structure used for a fuel cell includes a resin liner having a storage portion inside a cylindrical shape, and a dome portion provided at an axial end portion of the liner. A base for connecting an external pipe is attached to the dome portion so as to face axially outward.

[0003] Also, a fiber member containing a curable resin for reinforcement is wound around the liner to form a reinforcing layer (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional pressure vessel structure, when winding a fiber member around an injection-molded liner, the base is rotated to rotate the liner. As a result, the fiber member is wound around the liner while being pulled with a desired strength. Therefore, if the base and the liner slip, the fiber member cannot be fixed while being pulled with a desired strength.

[0006] Furthermore, when attempting to form a protrusion on the liner to prevent the nozzle from rotating, there was a risk of flow turbulence occurring in the resin material flowing into the area where this protrusion was formed. In addition, if there were temperature variations in the injected resin material, plastic distortion may occur during curing, indicating room for further improvement.

[0007] This invention aims to provide a pressure vessel structure that can improve flow turbulence during molding and reduce plastic strain. Ultimately, it aims to contribute to energy efficiency. [Means for solving the problem]

[0008] To solve the aforementioned problems, the pressure vessel structure of the present invention comprises a cylindrical synthetic resin liner having a reservoir inside, and a nozzle installed at the axial end of the liner. The liner comprises a dome portion provided at the axial end of the liner, a groove portion formed concavely in the radial center of the dome portion for which the nozzle is installed, and a locking portion protruding from the connection between the dome portion and the groove portion for locking the nozzle. The locking portion has a first wall portion extending radially from the dome portion toward the center, a second wall portion extending axially outward from the groove portion, and a top portion where the first wall portion and the second wall portion meet. The thickness of the first wall portion increases toward the top portion. The thickness of the second wall portion also increases toward the top portion. Furthermore, a weight-reducing portion is provided on the back side of the top portion. [Effects of the Invention]

[0009] The present invention aims to provide a pressure vessel structure that can improve flow turbulence during molding and reduce plastic strain. Ultimately, this contributes to energy efficiency. [Brief explanation of the drawing]

[0010] [Figure 1] This is a longitudinal cross-sectional view along the axial direction illustrating the overall configuration of a pressure vessel structure according to an embodiment of the present invention. [Figure 2]This is an enlarged cross-sectional view of part II in Figure 1, showing the configuration of the main parts of the pressure vessel structure. [Figure 3] This is a perspective view showing the nozzle attached to the dome portion of a pressure vessel structure. [Figure 4] This is a cross-sectional view taken at the position of line IV-IV in Figure 3, showing the configuration of the locking mechanism. [Figure 5] This is an enlarged cross-sectional view of section V in Figure 3, comparing the wall thickness of the flat section, the inclined section, and the connecting section. [Modes for carrying out the invention]

[0011] Hereinafter, one embodiment of the present invention will be described with reference to the drawings as appropriate. The same reference numerals will be used for identical components, and redundant descriptions will be omitted. Figure 1 illustrates the pressure vessel structure of the embodiment. Pressure vessel 1 is installed in fuel cell vehicles and natural gas vehicles and is used as a container for filling high-pressure hydrogen gas or natural gas.

[0012] The pressure vessel 1 comprises a resin liner 2 having a storage section 3 inside a cylindrical shape, and dome sections 4 provided at both axial ends of the liner 2. In addition, a reinforcing layer 7 is provided around the liner 2, in which a fibrous member containing a reinforcing curable resin is wrapped.

[0013] Of these, the dome portion 4 is provided with a groove 10 at its radial center for installing the nozzle 6 from the axial L outer side. The groove 10 is recessed inward in the axial direction of the liner 2 and is formed in a concave shape (frustoconical shape). The nozzle 6 is attached to the center of the groove 10 in the radial direction D via a collar member 5.

[0014] As shown in Figures 2 and 3, the nozzle 6 has a boss portion 6a to which the external piping is connected, extending outward in the axial direction L, and a disc-shaped flange portion 6b that extends continuously from the boss portion 6a and through the piping passage 6c. At least a portion of the outer edge of the flange portion 6b has a notched portion 6d recessed therein. The flange portion 6b is formed in a frustoconical shape and fits into the groove portion 10.

[0015] Furthermore, as shown in FIG. 2, a collar member 5 as an inner support member for supporting the base 6 is disposed inside the groove portion 10, that is, inside the axial direction L, in the direction in which the storage portion 3 is formed in the pressure vessel 1.

[0016] FIG. 3 shows the pressure vessel 1 in a state where the reinforcing layer 7 is not provided. The liner 2 includes a locking portion 12 for locking the base 6. The locking portion 12 of the embodiment protrudes from an annular connecting portion 11 that connects the dome portion 4 and the groove portion 10.

[0017] As shown in FIG. 4, the locking portion 12 of the embodiment has a first wall portion 13 extending from the dome portion 4 toward the center in the radial direction D and a second wall portion 14 extending from the groove portion 10 toward the outside in the axial direction L. The locking portion 12 also has a top portion 15 where the first wall portion 13 and the second wall portion 14 are joined together. [[ID=twelve]] [[ID=thirteen]]

[0018] [[ID=fourteen]] [[ID=fifteen]]In the locking portion 12 of the embodiment, the thickness t1 of the first wall portion 13 is increased from the dome-side base portion 13a continuous with the dome portion 4 toward the top portion 15. Also, in the locking portion 12, the thickness t2 of the second wall portion 14 is increased from the inclined-side base portion 14a continuous with the inclined portion 21 of the groove portion 10 toward the top portion 15. Further, a relieved portion 16 is provided on the back surface side of the top portion 15.

[0019] Therefore, in the locking portion 12, the cross-sectional thickness gradually changes, and the formability when molding the liner 2 can be improved. Also, when the base 6 is installed in the groove portion 10 of the pressure vessel 1 (see FIG. 3), the locking portion 12 is locked to a notch portion 6d recessed in the outer peripheral edge of the flange portion 6b of the base 6. Thereby, relative rotation between the base 6 and the liner 2 can be easily made impossible during assembly. [[ID=2three]]

[0020] [[ID=2four]] Also, as shown in FIG. 5, the groove portion 10 has an inclined portion 21. The inclined portion 21 is formed in a conical shape, descending toward the inside in the axial direction L as it goes toward the inside in the radial direction D. The groove portion 10 of the embodiment has a planar portion 23 formed in a ring shape. The planar portion 23 extends in a direction perpendicular (radial direction D) to the axial direction L from a connecting portion 22 located at the tip of the inclined portion 21. Further, the groove portion 10 has a cylindrical portion 25 that rises from the inner peripheral edge 24 of the planar portion 23 toward the outside in the axial direction L.

[0021] And the groove portion 10 is set such that the thickness t3 of the planar portion 23 and / or the thickness t4 of the connecting portion 22 connecting the planar portion 23 and the inclined portion 21 are each thinner than the thickness t5 of the inclined portion 21 (t3 <t5, t4 <t5). The connecting portion 22 of the embodiment bends and connects the planar portion 23 and the tip of the inclined portion 21 in an R shape at an angle shallower than 90 degrees. Further, in the embodiment, the thickness t3 of the planar portion 23 and the thickness t4 of the connecting portion 22 are set to be equal (t3 = t4).

[0022] Also, the collar member 5 has an annular flange portion 9 on the outer wall surface 8a of the hollow shaft portion 8. The flange portion 9 is provided with a flat outer surface 9a and extends outward in the radial direction D from the outer wall surface 8a. And the outer surface 9a of the flange portion 9 is abutted against the planar portion 23 of the groove portion 10 from the inside in the axial direction L.

[0023] Furthermore, in the pressure vessel 1 of the embodiment, the position of the connecting portion 22 in the radial direction D is set outside the outer peripheral edge of the flange portion 9 of the collar member 5. Thereby, the width dimension W in the radial direction D of the planar portion 23 can be set large. Therefore, further, the planar portion 23 and / or the connecting portion 22 having a small thickness can be deformed more easily than the inclined portion 21 and the connecting portion 11 to absorb stress.

[0024] And in the collar member 5 of the embodiment, small holes 31 are formed in the outer wall surface 8a of the hollow shaft portion 8 so as to communicate the inside and outside in the radial direction D. Thereby, the pressure applied by the fluid G from both sides inside and outside in the radial direction D of the cylindrical portion 25 is made uniform. Furthermore, an annular seal groove 32 is recessed in the inner circumferential surface of the piping passage 6c of the nozzle 6, in the portion facing the cylindrical portion 25. An annular seal ring 30 is fitted into the seal groove 32. As a result, the cylindrical portion 25 formed in the groove portion 10 of the pressure vessel 1 is interposed between the hollow shaft portion 8 and the nozzle 6, and the seal ring 30 abuts against its outer circumferential surface. Therefore, the space between the cylindrical portion 25 and the nozzle 6 is sealed by the seal ring 30.

[0025] In the pressure vessel structure of this embodiment, when assembling the pressure vessel 1, the hollow shaft portion 8 of the collar member 5 is inserted into the cylindrical portion 25 of the groove 10 from the axial L inner side. Next, the nozzle 6, which has the seal ring 30 fitted into the seal groove 32, is screwed onto the threaded portion provided at the tip of the hollow shaft portion 8 from the axial L outer side. As a result, the cylindrical portion 25 of the groove 10 is press-fitted between the nozzle 6 and the outer wall surface 8a of the hollow shaft portion 8.

[0026] In the pressure vessel structure of this embodiment, when the cylindrical portion 25 is press-fitted between the nozzle 6 and the outer wall surface 8a of the hollow shaft portion 8, the seal ring 30 is compressed radially D between the bottom of the seal groove 32 and the outer wall surface of the cylindrical portion 25, thereby sealing the space between the nozzle 6 and the cylindrical portion 25. Then, the fluid G, such as hydrogen gas, filling the storage section 3 flows between the nozzle 6 and the cylindrical section 25 through the small hole 31, as shown by the dashed line in Figure 5. This equalizes the pressure applied to both the inside and outside of the cylindrical section 25 in the radial direction D. As a result, deformation and movement of the seal ring 30 or liner 2 are reduced, the desired sealing performance is maintained, and the risk of fluid G leakage is eliminated.

[0027] Furthermore, stress caused by a temperature drop in hydrogen gas and other substances within the storage section 3 is absorbed by the deformation of the flat section 23 and / or connecting section 22 of the thin-walled groove section 10. This further reduces the displacement of the seal ring 30, allowing the desired sealing characteristics to be maintained. More specifically, as shown in Figure 5, the cylindrical portion 25 interposed between the inner circumferential surface of the nozzle 6, where the seal groove 32 is formed, and the outer wall surface 8a of the hollow shaft portion 8 is press-fitted and prevented from coming loose. On the other hand, the flat portion 23 and / or connecting portion 22 are deformable in the axial direction L outward relative to the outer surface 9a of the flange portion 9.

[0028] Therefore, the seal ring 30 in the seal groove 32 is compressed radially D between its bottom and the outer wall surface of the cylindrical portion 25, and does not move axially L even when pressure fluctuations occur. Consequently, good sealing performance can be maintained between the nozzle 6 and the cylindrical portion 25.

[0029] As described above, the pressure vessel structure of the present invention comprises a cylindrical synthetic resin liner 2 having a storage section 3 inside, and a nozzle 6 installed at the axial L end of the liner 2. The liner 2 comprises a dome section 4 provided at the axial L end of the liner 2, and a groove section 10 formed concavely in the radial D center of the dome section 4, in which the nozzle 6 is installed. The liner 2 also comprises a locking section 12 that protrudes from the connection section 11 between the dome section 4 and the groove section 10 and locks the nozzle 6. The locking section 12 has a first wall section 13 extending radially D towards the center from the dome section 4, a second wall section 14 extending axially L outward from the groove section 10, and a top section 15 where the first wall section 13 and the second wall section 14 meet. The thickness of the first wall section 13 increases towards the top section 15. The thickness of the second wall section 14 also increases towards the top section 15. Furthermore, a weight-reducing section 16 is provided on the back side of the top portion 15.

[0030] The pressure vessel structure of the present invention, configured in this manner, can provide a pressure vessel 1 that can improve flow turbulence and reduce plastic strain. In detail, the molten resin flowing through the first wall portion 13, the second wall portion 14, and the top portion 15 of the locking portion 12 shown in Figure 4 smoothly reaches the top portion 15 to which the first wall portion 13 and the second wall portion 14 are joined. Therefore, even if the locking portion 12 is provided protruding from the connecting portion 11, flow turbulence can be improved.

[0031] For example, it is easy to set the locking portion 12 so that a weld line does not form due to flow turbulence. This makes it possible to suppress a decrease in the strength of the locking portion 12. Furthermore, the weight-reducing portion 16 can reduce the thickness of the top portion 15. As a result, the temperature of the molten resin becomes more uniform when it cools. Consequently, the locking portion 12 can reduce plastic deformation.

[0032] This improves the strength of the locking portion 12, so that when the nozzle 6 is installed in the groove 10 of the pressure vessel 1, the locking portion 12 is locked into the notch portion 6d recessed in the outer edge of the flange portion 6b. Therefore, relative rotation between the nozzle 6 and the liner 2 can be prevented. For example, the reinforcing layer 7 is formed by the filament winding (FW) method. In the FW manufacturing process, a die 6 installed on the liner 2 is gripped by the rotating part of a winding machine (not shown). The winding machine then rotates the die 6 and the liner 2, winding the fibrous material impregnated with liquid curable resin around the liner 2 while applying the desired tensile force. During winding, it is conceivable that the liner 2 may detach from the die 6 and only the die 6 may rotate.

[0033] In the pressure vessel structure of this embodiment, the locking portion 12 of the liner 2 is locked into a notch portion 6d recessed in the outer peripheral edge of the flange portion 6b of the nozzle 6, so that relative rotation does not occur between the nozzle 6 and the liner 2. Therefore, even when tensile force is applied to the fiber member, the liner 2 rotates together with the nozzle 6. Consequently, it becomes possible to wrap the fiber member around the liner 2 at high speed, thereby reducing manufacturing costs.

[0034] Furthermore, a claw-locking structure is employed between the liner 2 and the nozzle 6, consisting of a locking portion 12 and a notched portion 6d. This makes processing easier and improves assembly compared to a screw-fit structure. It also increases the freedom of shape design. As a result, the manufacturing cost of the pressure vessel 1 can be reduced.

[0035] Furthermore, the groove 10 has an inclined portion 21 that descends axially L inward as it moves radially D inward, and a flat portion 23 that extends perpendicularly with respect to the axial direction L from the tip of the inclined portion 21 and is formed in an annular shape. The groove 10 also has a cylindrical portion 25 that rises axially L outward from the inner peripheral edge 24 of the flat portion 23. Inside the cylindrical portion 25, a collar member 5 is arranged as an inner support member that supports the nozzle 6. The gate portion for injection molding in the liner 2 may be provided on the inner or outer circumferential side of the cylindrical portion 25.

[0036] The color member 5 has a flange portion 9 that extends radially outward in an annular shape and abuts against the flat portion 23. The thickness t3 of the flat portion 23 and / or the thickness t4 of the connecting portion 22 that connects the flat portion 23 and the inclined portion 21 are set to be thinner than the thickness t5 of the inclined portion 21. Therefore, due to fluctuations in the internal pressure of the reservoir 3, the thin-walled flat section 23 and / or connecting section 22 deform before the dome section 4, absorbing the stress. Consequently, the amount of deformation in the liner 2, specifically in the section from the dome section 4 where stress is highest to the connecting section 11 of the groove section 10, can be reduced.

[0037] Furthermore, the thicknesses t3 and t4 of the flat portion 23 and the connecting portion 22 are thinner than the thickness t5 of the inclined portion 21, respectively. As a result, the flat portion 23 becomes like a leaf spring and can easily deform by moving closer to and away from the outer surface 9a in the axial direction L. As the temperature decreases, the flat portion 23 comes into contact perpendicularly with the outer surface 9a due to the stress acting in the axial direction L inward. The connecting portion 22, located radially D outward from the outer edge of the flange portion 9, easily deforms inward axial direction L. Therefore, the flat portion 23 and the connecting portion 22 can effectively absorb stress before the dome portion 4. It is preferable that the radially outer end of the flange portion 9 is radially inward from the connecting portion 22.

[0038] Furthermore, the liner 2 is surrounded by a reinforcing layer 7, which is made by wrapping a fibrous material containing a curable resin around it. As a result, the reinforcing layer 7 around the liner 2 does not deform due to a decrease in the outside temperature or a decrease in the temperature of the hydrogen gas or natural gas filled in the storage section 3. Therefore, the stress caused by the temperature decrease acts inward in the axial direction L, centered on the dome section 4 and / or the connecting section 11 that connects the dome section 4 and the groove section 10.

[0039] However, the thin-walled flat portion 23 and / or connecting portion 22 of the groove portion 10 can deform and absorb stress before the connecting portion 11 of the dome portion 4 and the groove portion 10. Therefore, the tensile stress near the connecting portion 11 in the axial direction L can be relieved. Therefore, the pressure vessel structure of the present invention exhibits practically beneficial effects, such as enabling high levels of stress relief.

[0040] The present invention is not limited to the embodiments described above, and various modifications are possible. The embodiments described above are illustrative examples provided to facilitate understanding of the present invention, and are not necessarily limited to those comprising all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to delete parts of the configuration of each embodiment, or to add or replace other configurations. Possible modifications to the above embodiments are, for example, as follows.

[0041] In this embodiment, the locking portion 12 is provided protruding from the annular connecting portion 11 that connects the dome portion 4 and the groove portion 10. However, the present invention is not particularly limited thereto. For example, the locking portion 12 and the notch portion 6d on the mouthpiece 6 side into which the locking portion 12 is locked may be one or more, and the shape, number, and material of the locking portion 12 and the notch portion 6d are not particularly limited. [Explanation of Symbols]

[0042] 1. Pressure vessel 2 Liners 3. Storage section 4. Dome section 6 nozzles 10 grooves 11 Connection part 12 Locking part 13 First wall 14 Second wall section 15 Top

Claims

1. A pressure vessel structure comprising a cylindrical synthetic resin liner having a storage compartment inside, and a nozzle installed at the axial end of the liner, The aforementioned liner, A dome portion provided at the axial end of the liner, A groove is formed in a concave shape in the radial center of the dome portion, where the nozzle is installed. It comprises a locking portion that protrudes from the connection portion between the dome portion and the groove portion and locks the nozzle, The locking portion has a first wall portion extending radially from the dome portion toward the center, a second wall portion extending axially outward from the groove portion, and a top portion where the first wall portion and the second wall portion meet. A pressure vessel structure characterized in that the first wall portion increases in thickness towards the top, and the second wall portion increases in thickness towards the top, with a weight-reducing section provided on the back side of the top.

2. The groove portion is A sloping section that descends axially inward as it moves radially inward, A planar portion is formed in an annular shape, extending perpendicularly in the axial direction from the tip of the inclined portion, It has a cylindrical portion that rises axially outward from the inner peripheral edge of the flat portion, An inner support member is positioned inside the cylindrical portion to support the nozzle. The inner support member has a flange portion that extends radially outward in an annular shape and abuts against the flat portion. The pressure vessel structure according to claim 1, characterized in that the thickness of the flat portion and / or the thickness of the connecting portion connecting the flat portion and the inclined portion is set to be thinner than the thickness of the inclined portion.

3. The pressure vessel structure according to claim 2, characterized in that the liner is surrounded by a reinforcing layer formed by wrapping a fibrous member containing a curable resin around it.

4. The pressure vessel structure according to claim 2, characterized in that the radially outer end of the flange portion is radially inward from the connecting portion.

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