A high-pressure vessel includes: a body portion formed in an open cylindrical shape; a cap, at least a part of the cap being inserted inside an opening of at least one end portion of the body portion to thereby plug the end portion; a first reinforcement layer provided at an outer peripheral surface of the body portion and configured by fiber-reinforced plastic having a fiber direction that coincides with a circumferential direction of the body portion; and a second reinforcement layer configured by fiber-reinforced plastic including fibers that pass through a center portion of the cap, as seen in the axial direction of the body portion, and that are disposed parallel to the axial direction of the body portion, as seen in a direction orthogonal to the axial direction of the body portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC 119 from Japanese Patent Application No. 2017-082041 filed on Apr. 18, 2017, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

Technical Field

A preferred embodiment relates to a high-pressure vessel.

Related Art

Japanese Patent Application Laid-open (JP-A) No. 2002-188794 discloses a high-pressure hydrogen tank serving as a vessel. The high-pressure hydrogen tank is configured to include a liner formed in a barrel shape and a reinforcement layer wound around the liner and configured by fiber-reinforced plastic. This configuration enhances the rigidity of the liner, so the high-pressure hydrogen tank can hold high-pressure hydrogen inside.

SUMMARY

However, because the high-pressure hydrogen tank disclosed in JP-A No. 2002-188794 is a large tank shaped like a barrel, there are cases where the cabin space and/or luggage space is reduced to install the high-pressure hydrogen tank in a vehicle. That is to say, there is the potential to not be able to efficiently utilize the vehicle space. To address this point, it is conceivable to provide plural small open cylindrical tanks that can be disposed in an empty space in the vehicle. However, in the case of an open cylindrical tank, it is necessary to provide caps to plug both axial direction end portions of the open cylindrical tank, but because of the pressure of the fluid inside the tank, loads arise in the caps in the directions in which the caps detach from the tank body. Consequently, there is room for improvement to improve the pressure resistance of the tank while efficiently utilizing the vehicle space.

In consideration of the above circumstances, an object of a preferred embodiment is to provide a high-pressure vessel that can improve the pressure resistance of the vessel.

A high-pressure vessel pertaining to a first aspect of the disclosure includes: a body portion formed in an open cylindrical shape, with at least one end portion in an axial direction of the body portion being open; a cap, at least part of the cap is inserted inside the opening of the end portion of the body portion to thereby plug the end portion; a first reinforcement layer provided at an outer peripheral surface of the body portion and configured by fiber-reinforced plastic having fiber direction that coincides with a circumferential direction of the body portion; and a second reinforcement layer integrated with the first reinforcement layer and configured by fiber-reinforced plastic including fibers that pass through a center portion of the cap, as seen in the axial direction of the body portion, and that are disposed parallel to the axial direction of the body portion, as seen in a direction orthogonal to the axial direction of the body portion.

According to the high-pressure vessel of the first aspect, the body portion is formed in an open cylindrical shape, at least one end portion of the body portion in the axial direction thereof (hereinafter simply called “the axial direction”) is open, and at least part of the cap is inserted inside the end portion to thereby plug the end portion. The first reinforcement layer configured by fiber-reinforced plastic having fiber direction that coincides with the circumferential direction of the body portion is provided at the outer peripheral surface of the body portion. Consequently, the pressure resistance of the body portion in its circumferential direction and radial direction is improved.

Additionally, the second reinforcement layer integrated with the first reinforcement layer is provided. The second reinforcement layer is configured by fiber-reinforced plastic in the same way as the first reinforcement layer, and the fibers of the second reinforcement layer are disposed passing through the center portion of the cap, as seen in the axial direction. Consequently, even in a case where loads outward in the axial direction have been input along the axial direction to the end portions in the axial direction of the body portion, the loads outward in the axial direction can be received uniformly by the second reinforcement layer and the first reinforcement layer integrated with the second reinforcement layer. Furthermore, the fibers of the second reinforcement layer are disposed parallel to the axial direction, as seen in a direction orthogonal to the axial direction. That is to say, the fiber direction of the fibers and the axial direction become the same direction, so loads outward in the axial direction can be more reliably received by the fibers of the second reinforcement layer. For this reason, the pressure resistance in the axial direction of the high-pressure vessel itself can be improved.

A high-pressure vessel of a second aspect of the disclosure is the first aspect, further including a coupling member that is capable of coupling a plurality of caps to each other, and a fastening member, at least a part of each of the plurality of caps being respectively configured to be inserted inside the opening of the at least one end portion of the body portion of each of a plurality high-pressure vessels, wherein a communicative flow path that connects an inside and an outside of the body portion is provided in each cap. A projecting portion that projects outward in the axial direction of the body portion is provided at an outer peripheral side of an end portion that is positioned at an outer end of each cap in the axial direction. A fastening hole is provided inside the projecting portion, with the coupling member being fastened to the projecting portion by the fastening member inserted from an outside into the fastening hole, and a coupling flow path communicated with an outside of the coupling member is provided inside the coupling member, with the communicative flow path in each cap and the coupling flow path in the coupling member being communicated with each other via an inside flow path provided inside the fastening member.

According to the high-pressure vessel of the second aspect, the high-pressure vessel further includes the coupling member that is capable of coupling a plurality of caps to each other, and the fastening member. At least a part of each of the plurality of caps is respectively configured to be inserted inside the opening of the at least one end portion of the body portion of each of a plurality high-pressure vessels. The projecting portion that projects outward in the axial direction is provided at the outer peripheral side of the end portion in the axial direction outer end of each cap. The communicative flow path that connects the inside and the outside of the body portion is provided in each cap, the fastening hole is provided inside the projecting portion of each cap, and the coupling member is fastened as a result of the fastening member being inserted from the outside into the fastening hole. The communicative flow path is communicated, via the inside flow path provided inside the fastening member, with the coupling flow path communicated with the outside of the coupling member. For this reason, the fluid inside the high-pressure vessel can be supplied to the outside via the projecting portion of each cap, and the fluid can be put into the high-pressure vessel from the outside. Consequently, it is not necessary to provide a communicative hole somewhere in each cap outside the projecting portion, so more fibers of the second reinforcement layer can be disposed at the part of each cap positioned other than the projecting portion.

A high-pressure vessel of a third aspect of the disclosure is the second aspect, wherein the projecting portion is provided as a pair of projection portions across the center portion of each cap, as seen in the axial direction of the body portion.

According to the third aspect, the projecting portion is provided as a pair of projection portions across the center portion of each cap, as seen in the axial direction, so the coupling member is fastened to each cap via a pair of the fastening members. Consequently, the rigidity of the attachment of the coupling member to each cap can be improved.

Furthermore, the projecting portions are provided on area of each cap positioned outside the center portion, so the fibers of the second reinforcement layer can be disposed so as to pass through the center portion of each cap. Consequently, the fibers of the second reinforcement layer can be prevented from sliding at each cap and no longer catching at each cap as a result of the fibers being disposed passing through area of each cap positioned outside the center portion.

A high-pressure vessel of a fourth aspect of the disclosure is the first aspect, wherein a recess portion that opens toward the inside of the body portion and is recessed outward in the axial direction is formed in the part of the cap inserted inside the body portion.

According to the fourth aspect, the recess portion that opens toward the inside of the body portion and that is recessed outward in the axial direction is formed in the part of the cap inserted inside the body portion. Consequently, the capacity inside the high-pressure vessel can be further increased by the recess portion.

A high-pressure vessel of a fifth aspect of the disclosure is the first aspect, wherein the second reinforcement layer is provided at an outer side of the first reinforcement layer and at an outer surface of the cap.

According to the fifth aspect, the second reinforcement layer is provided at an outer side of the first reinforcement layer and at an outer surface of the cap. Consequently, in a case where loads outward in the axial direction have been input along the axial direction to the end portions in the axial direction of the body portion, the loads can be received reliably by the second reinforcement layer. The pressure resistance in the axial direction of the high-pressure vessel itself can be improved.

A high-pressure vessel of a sixth aspect of the disclosure is the second aspect or the third aspect, wherein the fibers of the second reinforcement layer are wound in an area at the end portion of each cap except an area where the projecting portion is provided.

According to the sixth aspect, the fibers of the second reinforcement layer are wound in an area at the end portion of each cap except an area where the projecting portion is provided. Consequently, in a case where loads outward in the axial direction have been input along the axial direction to the end portions in the axial direction of the body portion, the loads can be received reliably by the second reinforcement layer. The pressure resistance in the axial direction of the high-pressure vessel itself can be improved.

DETAILED DESCRIPTION

An embodiment of the present invention will be described below usingFIG. 1toFIG. 4.

A tank module provided in a vehicle not shown in the drawings is configured by combining more than one high-pressure tank10serving as a high-pressure vessel shown inFIG. 1. As an example, the tank module has a configuration where the high-pressure tanks10are plurally lined up on the vehicle underside of a floor panel (not shown in the drawings) of a fuel cell vehicle and are coupled to each other.

The high-pressure tanks10are respectively formed in a substantially closed cylindrical shape whose axial direction (longitudinal direction) coincides with a vehicle width direction or a vehicle front and rear direction as an example. As shown inFIG. 2, each of the high-pressure tank10is configured to include a body portion12, a first reinforcement layer14, and a second reinforcement layer16. The body portion12is formed in an open cylindrical shape whose axial direction end portions are open and is configured by aluminum alloy as an example. It will be noted that the body portion12has a radial dimension capable of being accommodated in an empty space on the vehicle underside of the floor panel.

A pair of caps20are respectively inserted inside a first end portion on one axial direction side and a second end portion on the other axial direction side of the body portion12of the high-pressure tank10. The caps20are formed in substantially domed shapes that are convex outward in the axial direction. Each of the caps20has a body insertion portion22(seeFIG. 4), a communicative flow path24(seeFIG. 2), and projecting portions30(seeFIG. 4). The body insertion portion22is disposed in a position corresponding to the body portion12, and is formed in a substantially cylindrical shape that projects inward in the axial direction of the body portion12. The body insertion portion22has a later-described recess portion32that opens toward an inside of the body portion12. An outer peripheral surface23of the body insertion portion22opposes an inner peripheral surface of the body portion12.

The recess portion32provided inside the body insertion portion22has a shape that is recessed outward in the axial direction in a state in which the cap20is inserted into the body portion12. The recess portion32has a tapered portion34and a domed portion36. The tapered portion34is disposed on an end face38side of the distal end of the body insertion portion22and is formed in such a way that its diameter decreases outward in the axial direction. Furthermore, the domed portion36is disposed on the axial direction outer side of the recess portion32and is formed in a substantially domed shape. It will be noted that an opening of the communicative flow path24is provided at the domed portion36.

A packing accommodating portion26is provided in the body insertion portion22, and an O-ring27is accommodated in the packing accommodating portion26. The O-ring27is in abutting contact with the inner peripheral surface of the body portion12as a result of being elastically deformed along the radial direction of the body portion12.

Plural (in the present embodiment, four as an example) fastening holes54are formed at the end face38of the body insertion portion22(seeFIG. 4). Furthermore, a retention plate56formed in a disc shape is in abutting contact with the end face38, and a communicating hole60that communicates with the recess portion32of the cap20is formed at a central portion of the retention plate56as seen in the axial direction. Moreover, through holes62running through the retention plate56in the thickness direction thereof are formed at the retention plate56in positions corresponding to the fastening holes54at the end face38of the cap20, and bolts64are passed through and fastened in the through holes62and the fastening holes54at the end face38, whereby the retention plate56is attached to the end face38. It will be noted that the diameter of the retention plate56is set to be substantially identical to that of the general portion (the part other than the packing accommodating portion26) of the body insertion portion22. That is to say, an outer peripheral surface68of the retention plate56opposes the inner peripheral surface of the body portion12. The first end portion on the one axial direction side and the second end portion on the other axial direction side of the body portion12are plugged by the body insertion portions22of the caps20described above.

The projecting portions30are provided at an outer peripheral side of an outer end portion72in the axial direction of the cap20which has been inserted in the body portion12. Specifically, as shown inFIG. 3, the projecting portions30are provided as a pair across a center portion28, that corresponds to an axis C, at the outer end portion72of the cap20as seen in the axial direction. As shown inFIG. 2, each projecting portion30is formed in a closed cylindrical shape that projects outward in the axial direction. Inside the projecting portions30are formed fastening holes74having threaded portions formed in their inner peripheral surfaces, and an opening of the communicative flow path24is provided at a bottom portion76of the fastening hole74in one of the projecting portions30.

The communicative flow path24is formed inside the cap20. The communicative flow path24is formed in an L-shape inside the body insertion portion22and connects the inside and outside of the body portion12of the high-pressure tank10.

A coupling member40is fastened to the projecting portions30of the cap20. The coupling member40is formed substantially in a shape of a plate made of metal as an example, and an end face44of the coupling member40on one side in the thickness direction of the coupling member40is in abutting contact with an outer end faces42in the axial direction of the projecting portions30of the plurally lined up high-pressure tanks10. Furthermore, through holes46running through the coupling member40in the thickness direction thereof are formed in the coupling member40in positions corresponding to the fastening holes74in the projecting portions30. It will be noted that more than one coupling flow path48extending along a direction orthogonal to the thickness direction of the coupling member40are formed inside the coupling member40. Specifically, one opening of the coupling flow path48is provided at a side surface of the through hole46. Furthermore, the other opening of the coupling flow path48is provided at a side surface of another through hole46formed at the coupling member40in correspondence to a fastening hole74at which is provided a communicative flow path24in another adjacent high-pressure tank10not shown in the drawings. It will be noted that an opening of the coupling flow path48provided at an end portion of the coupling member40is open to the outside of the coupling member40.

The coupling member40and the cap20are fastened to each other by bolts50and52serving as fastening members that are inserted and screwed into the through holes46in the coupling member40and the fastening holes74in the projecting portions30of the cap20. In the through hole46of the coupling member40, that corresponds to the fastening hole74in which is formed the communicative flow path24, O-ring accommodating portions47and49are formed. The O-ring accommodating portions47and49are cut out formed outwardly in an radial direction of the through hole46and are disposed at an outer side and an inner side in the axial direction of the through hole46. O-rings51are accommodated inside the O-ring accommodating portions47and49, and the O-rings51are in abutting contact with threads (not shown in the drawings) of the bolts50as a result of becoming elastically deformed along the radial direction of the through hole46.

Furthermore, an O-ring accommodating portion58formed in a shape recessed inwardly in a radial direction of the bolt50is formed in a distal end portion of the bolt50screwed into the fastening hole74in which the communicative flow path24is formed. An O-ring61is accommodated inside the O-ring accommodating portion58, and the O-ring61is in abutting contact with the inner peripheral surface of the fastening hole74as a result of becoming elastically deformed along the radial direction of the bolt50.

An inside flow path66is formed inside the bolt50. The inside flow path66is formed by an axial direction flow path66A communicated along the axial direction of the bolt50and a radial direction flow path66B communicated along the radial direction of the bolt50. The axial direction flow path66A has an opening in a central portion of a bottom surface70of the bolt50. Furthermore, the radial direction flow path66B has an opening in a position in an outer peripheral surface of the bolt50corresponding to the coupling flow path48in the coupling member40. Consequently, the fluid inside the high-pressure tank10can flow from the communicative flow path24in the cap20via the inside flow path66in the bolt50to the coupling flow path48in the coupling member40. The communicative flow path24, the inside flow path66in the bolt50, and the coupling flow path48having the configurations described above communicate the insides of the plural high-pressure tanks10to each other and further communicate to the outside of the coupling member40. It will be noted that the fluid that flows from the opening of the radial direction flow path66B in the bolt50is capable of flowing toward the coupling flow path48in the coupling member40while flowing along the spaces between the threads (not shown in the drawings) of the bolt50, so the opening of the radial direction flow path66B and the opening of the coupling flow path48do not invariably need to be in corresponding positions.

A valve not shown in the drawings is provided in the coupling flow path48in the coupling member40, and the valve can control the volume of the fluid flowing in the coupling flow path48. Additionally, the coupling flow path48is connected to a fuel cell stack or the like not shown in the drawings.

Next, the first reinforcement layer14of the high-pressure tank10is a carbon fiber-reinforced plastic (CFRP) sheet and is wrapped around an outer peripheral surface18of the body portion12. Inside the first reinforcement layer14, carbon fibers not shown in the drawings are arrayed along the circumferential direction of the body portion12. In other words, the fiber direction of the first reinforcement layer14coincides with the circumferential direction of the body portion12.

The second reinforcement layer16is provided at a radial direction outer side of the first reinforcement layer14and at an outer surfaces of the pair of caps20. The second reinforcement layer16is configured by carbon fiber-reinforced plastic (CFRP) having plural fibers78inside (seeFIG. 3). It will be noted that in the drawings the fibers78are depicted as being fatter than they actually are in order to show them in a way that is easy to understand, and the fibers78are also depicted as being fewer in number than they actually are in order to show the set direction of the fibers78in a way that is easy to understand.

As shown inFIG. 3, the fibers78of the second reinforcement layer16are wound across the axial direction outer end portion72of the cap20. Specifically, the fibers78are linearly wound passing through the center portion28of the cap20and in a range except the projecting portions30of the cap20as seen in the axial direction. In other words, the fibers78are wound passing through geodesics of the axial direction outer end portion72of the cap20. It will be noted that the fibers78wound across the axial direction outer end portion72of the cap20are, as shown inFIG. 1, wound on the first reinforcement layer14of the body portion12from the one cap20inserted into the first end portion of the body portion12toward the other cap20inserted into the second end portion of the body portion12along the axial direction as seen in a direction orthogonal to the axial direction.

Furthermore, the fibers78are wound passing through geodesics at the axial direction outer end portion72of the other cap20in the same way as they are at the one cap20. Additionally, the fibers78are wound on the first reinforcement layer14along the axial direction from the other cap20inserted into the second end portion of the body portion12to the one cap20inserted into the first end portion of the body portion12. The second reinforcement layer16is formed by repeating the above process multiple times to form a layer (see the dashed double-dotted line inFIG. 3). Additionally, the second reinforcement layer16and the first reinforcement layer14are integrated with each other by adding the step of heating and hardening them at the same timing after the fibers78have been wound around the body portion12and the caps20. It will be noted that inFIG. 2the first reinforcement layer14and the second reinforcement layer16are depicted as separate members in order to show them in a way that is easy to understand.

Action and Effects of Embodiment

Next, the action and effects of the present embodiment will be described.

In the present embodiment, as shown inFIG. 2, the body portion12is formed in an open cylindrical shape, at least one end portion of the body portion12in the axial direction thereof is open, and the body insertion portion22of the cap20is inserted inside the end portion to thereby plug the end portion. The first reinforcement layer14configured by fiber-reinforced plastic whose fiber direction coincides with the circumferential direction of the body portion12is provided on the outer peripheral surface18of the body portion12. Consequently, the pressure resistance of the body portion12in its circumferential direction and radial direction is improved.

Additionally, the second reinforcement layer16integrated with the first reinforcement layer14is provided. The second reinforcement layer16is configured by fiber-reinforced plastic in the same way as the first reinforcement layer14, and the fibers of the second reinforcement layer16are disposed passing through the center portion28of the cap20as seen in the axial direction of the body portion12. Consequently, even in a case where loads that is directed outward in the axial direction have been input along the axial direction to end portions of the body portion12, the loads can be received uniformly by the second reinforcement layer16and the first reinforcement layer14integrated with the second reinforcement layer16. Furthermore, the fibers78of the second reinforcement layer16are disposed parallel to the axial direction of the high-pressure tank10as seen in a direction orthogonal to the axial direction. That is to say, the fiber direction of the fibers78and the axial direction of the high-pressure tank10become the same direction, so loads directed outward in the axial direction can be more reliably received by the fibers78of the second reinforcement layer16. For this reason, the pressure resistance in the axial direction of the high-pressure tank10itself can be improved. Because of this, the pressure resistance of the high-pressure tank10can be improved.

Furthermore, the projecting portions30that project outward in the axial direction are provided at the outer peripheral side of the axial direction outer end portion72of the cap20. The fastening hole74into which the bolt50is inserted and fastened from the outside is provided in one of the projecting portions30of the cap20. The communicative flow path24that connects the inside and the outside of the body portion12is provided inside the cap20. The communicative flow path24is communicated, via the inside flow path66provided inside the bolt50, with the coupling flow path48communicated with the outside of the coupling member40. For this reason, the fluid inside the high-pressure tank10can be supplied to the outside via the projecting portion30of the cap20, and the fluid can be put into the high-pressure tank10from the outside. Consequently, it is not necessary to provide the communicative flow path24somewhere in the cap20outside the projecting portions30, so more fibers78of the second reinforcement layer16can be disposed on the part of the cap20positioned other than the projecting portions30. Because of this, the pressure resistance in the axial direction of the high-pressure tank10can be further improved.

Moreover, the projecting portions30are provided as a pair at the cap20across the center portion28of the cap20as seen in the axial direction of the body portion12(seeFIG. 3), so the coupling member40can be fastened to the cap20via the pair of bolts50and52. Consequently, the rigidity of the attachment of the coupling member40to the cap20can be improved. Because of this, the state of attachment of the coupling member40to the cap20can be stabilized.

Moreover, the projecting portions30are provided at parts positioned outside the center portion28of the cap20, so the fibers78of the second reinforcement layer16can be disposed so as to pass through the center portion28of the cap20. Consequently, the fibers78of the second reinforcement layer16can be prevented from sliding on the cap20and no longer staying at the cap20as a result of the fibers78being disposed passing through parts of the cap20positioned outside the center portion28.

Furthermore, the recess portion32that opens toward the inside of the body portion12and is recessed outward in the axial direction of the body portion12is formed in the part of the cap20inserted inside the body portion12. Consequently, the capacity inside the high-pressure tank10can be further increased by the recess portion32.

Moreover, because the recess portion32is formed in a substantially domed shape, stress can be prevented from partially concentrating even in a case where a high-pressure fluid is held in the high-pressure tank10.

It will be noted that although in the embodiment the recess portion32provided in the cap20is formed in a substantially domed shape, the recess portion32is not limited to this and may also be formed in another shape such as an open cylindrical shape.

Furthermore, although the high-pressure tank10has a configuration where the caps20are inserted inside the first end portion on the one axial direction side and the second end portion on the other axial direction side of the body portion12, the high-pressure tank10is not limited to this and may also have a configuration where a cap20is provided at only at least one end portion in the axial direction of the body portion12.

An embodiment of the present invention has been described above, but the present invention is not limited to what is described above and can be modified and implemented in a variety of ways in addition to what is described above in a range that does not depart from the scope of the claims.