Vane pump and fuel vapor leakage detection device using the same

A vane pump comprising:

• a pump chamber;
• a housing having one communication hole, an other communication hole, which is different from the one communication hole, and a first connection hole, the one communication hole configured to communicate with the pump chamber, the other communication hole configured to communicate with the pump chamber, the first connection hole communicating an outside of the housing with one of the one communication hole and the other communication hole;
• a rotor rotational in the pump chamber, the rotor including a plurality of vanes configured to slide on an inner wall of the housing, the inner wall forming the pump chamber;
• and
• a motor configured to rotate the rotor, wherein
• the housing includes a tubular portion, a first plate portion, a second plate portion, and a first connection hole forming portion,
• the first plate portion covers one opening of the pump chamber in a direction of a center axis of the tubular portion,
• the second plate portion covers an other opening of the pump chamber in the direction of the center axis,
• the first connection hole forming portion is equipped to a radially outside of the tubular portion to form the first connection hole,
• a length of the first connection hole forming portion in the direction of the center axis is less than or equal to a length of the tubular portion in the direction of the center axis,
• a first imaginary line connects a center of an outer opening of the first connection hole with a point on the center axis,
• the first imaginary line intersects perpendicularly with the center axis, and
• a length of the first connection hole in a direction perpendicular to both the first imaginary line and the center axis is greater than a length of the first connection hole in the direction of the center axis.