Reservoir tank

1. A reservoir tank which includes a reservoir body formed in a hollow box shape for storing a hydraulic fluid inside the reservoir tank, and is connected to a vehicle master cylinder in such a way that the hydraulic fluid flows into and out, wherein:

the reservoir body includes a top plate portion formed in a plate shape,

on an inner wall surface of the top plate portion, a flow path portion which has one or more flow paths formed in a serpentine fashion so as to be opened toward a lower side in a vertical direction is provided in a protruding manner,

on a downstream side of the flow path, an opening is formed,

the flow path portion is composed of a plurality of first ribs and a plurality of second ribs provided in a protruding manner from the inner wall surface of the top plate portion and arranged so as to face each other,

at least one of the plurality of first ribs is disposed such that a leading end of the first rib facing the second ribs enters between leading ends of two neighboring second ribs facing the first ribs, and

at least one of the plurality of second ribs is disposed such that a leading end of the second rib enters between leading ends of two neighboring first ribs.

2. The reservoir tank according to claim 1 , wherein:

the leading ends of the first ribs are disposed closer to the opening than the base ends of the first ribs are, and

the leading ends of the second ribs are disposed closer to the opening than the base ends of the second ribs are.

3. The reservoir tank according to claim 2 , wherein:

the first ribs and the second ribs have such a step shape that the base end lengths of the base ends in directions along the vertical direction are longer than the leading end lengths of the leading ends in directions along the vertical direction, from the base ends toward the leading ends, and

the upper ends of the first ribs and the second ribs in the vertical direction are integrally fixed to the inner wall surface of the top plate portion, and the base ends of the first ribs and the base ends of the second ribs are integrally fixed to the inner surface of the reservoir body.

4. The reservoir tank according to claim 1 , wherein:

the opening is a slit formed by a pair of wall members disposed on the downstream side of the flow path portion and provided in a protruding manner from the inner wall surface of the top plate portion toward the lower side in the vertical direction.

5. The reservoir tank according to claim 4 , wherein:

the opening is disposed closer to the flow path portion than to an end part of the top plate portion.

6. A reservoir tank which includes a reservoir body formed in a hollow box shape for storing a hydraulic fluid inside the reservoir tank, and is connected to a vehicle master cylinder in such a way that the hydraulic fluid flows into and out, wherein:

the reservoir body includes a top plate portion formed in a plate shape,

on an inner wall surface of the top plate portion, a flow path portion which has one or more flow paths formed in a serpentine fashion so as to be opened toward a lower side in a vertical direction is provided in a protruding manner,

on a downstream side of the flow path, an opening is formed, and

the opening is a slit formed by a pair of wall members disposed on the downstream side of the flow path portion and provided in a protruding manner from the inner wall surface of the top plate portion toward the lower side in the vertical direction.

7. The reservoir tank according to claim 6 , wherein:

the opening is disposed closer to the flow path portion than to an end part of the top plate portion.