Fuel supply device

1. A fuel supply device comprising:

a supply main body, which is configured to be inserted through an insertion opening of a fuel tank while the supply main body is oriented such that a specific inserting direction of the supply main body is directed toward the insertion opening;

a surface level detection device that is configured to detect a level of a surface of fuel through use of a float, which is configured to float on the fuel, wherein:

the supply main body includes a lower limit stopper, which limits displacement of the float toward a lower side, wherein the supply main body is configured to be placed in an inside of the fuel tank and supply the fuel to an outside of the fuel tank;

the surface level detection device includes a surface level detection unit that includes the float and is rotatable relative to the supply main body;

rotation of the surface level detection unit toward the lower side is limited through contact of the surface level detection unit to the lower limit stopper; and

a rotational range of the surface level detection unit is defined to include at least a space located on a side of the supply main body in the inserting direction; and

a support stay that supports the supply main body in a manner that enables rotation of the supply main body about an imaginary main body rotational axis that serves as a rotational center of the supply main body, wherein:

the supply main body is held in an installation orientation of the supply main body, when the supply main body is installed in an installed state in the inside of the fuel tank;

the supply main body is in an insertion orientation when the supply main body is being inserted through the insertion opening;

the supply main body is rotated toward an upper side relative to the support stay when the supply main body is moved to the installation orientation from the insertion orientation;

in the insertion orientation, the surface level detection unit is rotatable relative to the supply main body;

in a state where the supply main body is placed in the insertion orientation, at which an imaginary rotational center axis of the surface level detection unit and a center of gravity of the surface level detection unit are placed along an imaginary plane that extends in a gravitational direction, a distal end part of the surface level detection unit, which is furthermost from the imaginary rotational center axis of the surface level detection unit, is located on one side of the imaginary plane, which is opposite to a bottom of the supply main body in a direction that is perpendicular to the imaginary plane;

the bottom of the supply main body is configured to contact a bottom wall surface of the fuel tank when the supply main body is held in the installation orientation, and the imaginary main body rotational axis is located on another side of the imaginary plane which is opposite to the one side in the direction that is perpendicular to the imaginary plane;

the distal end part is configured to contact the bottom wall surface and slide along the bottom wall surface toward the upper side as the supply main body is moved from the insertion orientation to the installation orientation;

the surface level detection unit includes a sender arm that is formed in one-piece and is in a form of rod;

the sender arm is configured to rotate about the imaginary rotation center axis;

the float is coupled to a distal end part of the sender arm; and

the center of gravity is located at the float.

2. The fuel supply device according to claim 1 , wherein the imaginary rotational center axis of the surface level detection unit is located on the upper side of the main body rotational axis of the supply main body.

3. The fuel supply device according to claim 1 , wherein the imaginary rotational center axis of the surface level detection unit is set to orient such that the imaginary rotational center axis intersects an imaginary perpendicular plane that is perpendicular to the main body rotational axis.

4. The fuel supply device according to claim 1 , wherein the imaginary rotational center axis of the surface level detection unit is set to orient such that the imaginary rotational center axis extends parallel to the main body rotational axis of the supply main body.

5. The fuel supply device according to claim 1 , wherein in the state where the supply main body is placed in the insertion orientation, the lower limit stopper is located on the upper side of the imaginary rotational center axis of the surface level detection unit in an up-and-down direction in parallel with the gravitational direction.

6. The fuel supply device according to claim 1 , wherein in the state where the supply main body is placed in the insertion orientation, the surface level detection unit is spaced away from the lower limit stopper of the surface level detection unit.