Pressure container

1. A pressure container comprising:

a hollow container body whose inner surface is coated with a resinous liner and which has an opening at one end thereof; and

an opening metal attached at a circumferential edge of the opening so as to protrude from the container body, the opening metal having a flange that extends in a radial direction of the container body, wherein

the liner has a self-sealing part abutting with the flange for sealing and a ring groove, which opens radially outward;

a ring-shaped constraint member is provided around the self-sealing part and is accommodated within the ring groove so as to restrict an expansion of the liner to be caused by an expansion of the container body;

the constraint member is formed of a fiber reinforced plastic filament winding; and

the constraint member is located on an outer side of the self-sealing part in the radial direction such that the flange is not located between the constraint member and the self-sealing part.

2. The pressure container as claimed in claim 1 , wherein an easily-displaceable part that is elongatable and deformable more easily than the remaining portion thereof is formed on an outer peripheral side of the self-sealing part in the radial direction.

3. The pressure container as claimed in claim 1 , wherein the liner is formed of a laminate structure including a gas barrier-layer of EVOH and a cover resin layer.

4. A pressure container as claimed in claim 1 ,

wherein the liner has a multi-layered structure that includes a gas-barrier layer formed of EVOH for shielding a penetration of a gas filled in the container body, and

a cover resin layer formed as at least one of an inner layer and an outer layer of the gas-barrier layer for ensuring a low-temperature impact resistance of the container body.

5. The pressure container as claimed in claim 4 , wherein the liner is constituted by bonding plural split bodies that are separately formed, and a bonding part between the split bodies are formed of only one of the gas barrier layer and the cover resin layer.

6. The pressure container as claimed in claim 5 , wherein the bonding part of the liner is formed of only the cover resin layer, and a second gas-barrier layer is laminated at least on the bonding part as an outer layer of the bonding part, and the constraint layer is formed as the outer layer of the container body and the second gas-barrier layer.

7. The pressure container as claimed in claim 5 , wherein the bonding part of the liner is formed of only the gas-barrier layer, and a second cover resin layer is laminated at least on the bonding part as the outer layer of the part, and the constraint layer is formed as the outer layer of the container body and the second cover resin layer.

8. A pressure container comprising:

a hollow container body, the inner surface of which is coated with a resinous liner, wherein an opening is located at one end of the hollow container body; and

an opening metal attached at a circumferential edge of the opening to protrude from the container body, the opening metal having a flange that extends in a radial direction of the container body, wherein

the liner has a self-sealing part abutting against the flange for sealing and a ring groove, which opens radially outward;

a ring-shaped constraint member is provided around the self-sealing part and is accommodated within the ring groove to restrict expansion of the liner caused by expansion of the container body;

the constraint member is a filament winding of fiber reinforced plastic; and

the constraint member applies force in a radially inward direction to an outer surface of the self-sealing part to restrict expansion of the liner, and

the constraint member is located radially outward of the flange.