Fueling device

1. A fueling device, comprising:

a filler neck that is configured to form a fuel flow path, wherein the filler neck has an engaged recess provided on at least part of an outer circumference thereof;

a cover member that has an engagement projection and an extension portion, wherein

the engagement projection is engaged with a side wall of the engaged recess and is mounted to the outer circumference of the filler neck on an opening side of the fuel flow path,

the extension portion is extended from the engagement portion in a downstream direction of the fuel flow path to face the outer circumference of the filler neck,

the extension portion is closer to an end of the cover member than the engagement projection, and

a thickness of the extension portion in a radial direction of the filler neck is the same as that of the cover member; and

a restraint member that is configured to surround at least the extension portion, wherein the restraint member is arranged to restrain at least the extension portion from an outside of the cover member at a location that is further downstream in the direction of the fuel flow path than the side wall of the engaged recess, and the restraint member presses the cover member against the filler neck to restrain the cover member with respect to the filler neck.

2. The fueling device according to claim 1 , wherein the restraint member is arranged to restrain a circumferential wall area of the cover member in which the engagement projection is formed and to restrain the extension portion.

3. The fueling device according to claim 1 , wherein the engaged recess is an inner recess, and the cover member has an outer recess that is formed on at least part of the outer circumference to receive the restrain member therein.

4. The fueling device according to claim 1 , wherein

the filler neck has a projection that is provided on at least part of the outer circumference of the filler neck downstream of the engaged recess and is protruded outward, and

at least part of the restraint member is brought into contact with and supported by the projection in a state such that the restraint member restrains the cover member to the outer circumference of the filler neck.

5. The fueling device according to claim 1 , wherein the restraint member comprises a first restraint member and a second restraint member that are separable from each other.

6. The fueling deice according to claim 1 , wherein

the restraint member is provided from an elastic member formed in a partly open arc shape, and

the elastic member has an inner circumferential shape corresponding to shape of at least one half of the outer circumference of the cover member surrounded by the restraint member.

7. The fueling device according to claim 1 , wherein

the engaged recess is a bottomed recess that is extended from the outer circumference of the filler neck outward and toward an upstream side of the fuel flow path, and

the engagement projection is provided on an end of the cover member and is to be fitted in the bottomed recess.

8. The fueling device according to claim 7 , wherein the side wall of the engaged recess is a side wall of the bottomed recess.

9. The fueling device according to claim 1 , wherein the side wall of the engaged recess has an engaged surface that faces in the downstream direction of the fuel flow path, and the engagement projection has an engagement surface that faces in an upstream direction of the fuel flow path and is configured to engage the engaged surface of the side wall when the cover is mounted on the filler neck.

10. The fueling device according to claim 1 , wherein the engaged recess has an opening that faces in a radially outward direction of the filler neck.

11. The fueling device according to claim 1 , wherein the engagement projection projects from an inner surface of the cover member in a radially inward direction of the cover member to engage with the side wall of the engaged recess.

12. The fueling device according to claim 1 , wherein the restraint member is annular, and an inner surface of the restraint member directly contacts an outer surface of the cover member.

13. The fueling device according to claim 1 , wherein the cover member is a single, unitary part.

14. The fueling device according to claim 1 , wherein the extension portion extends beyond the engaged recess in the downstream direction of the fuel flow path.

15. The fueling device according to claim 1 , wherein the restraint member surrounds the extension portion and a section of the cover member in which the engagement projection is formed, from an outside of the cover member, at a location that is further upstream in the direction of the fuel flow path than the extension portion, to press the cover member against the filler neck to restrain the cover member with respect to the filler neck.