Manifold
A manifold includes an end plate, which has an opposed surface facing an end in a cell stacking direction of a cell stack, a recess, which opens in the opposed surface and forms a flow path, and ribs protruding from the bottom surface of the recess to the opening position of the recess. Portions of a plastic layer that cover the opposed surface and the distal end faces in the protruding direction of the ribs contact the end in the cell stacking direction of the cell stack. The portions of the plastic layer that cover the distal end faces in the protruding direction of the ribs each have a cooling passage, which causes cooling water in the flow path to flow to the space between those portions of the plastic layer and a contact surface of the end in the cell stacking direction of the cell stack.
1. A manifold that is attached to an end in a cell stacking direction of a cell stack in a fuel cell and is used to supply coolant to and discharge coolant from the cell stack, the manifold comprising:
an end plate, which has an opposed surface that faces the end in the cell stacking direction of the cell stack;
a recess, which opens in the opposed surface and forms a flow path in which the coolant flows;
a rib, which protrudes from a bottom surface of the recess to an opening position of the recess on the opposed surface; and
a plastic layer, which is formed to cover the opposed surface, the recess, and the rib, wherein portions of the plastic layer that cover the opposed surface and a distal end face in a protruding direction of the rib contact the end in the cell stacking direction of the cell stack,
wherein the portion of the plastic layer that covers the distal end face in the protruding direction of the rib has a cooling passage that causes coolant in the flow path formed by the recess to flow to a space between that portion of the plastic layer and a contact surface of the end in the cell stacking direction of the cell stack, and
wherein the cooling passage includes, in the portion of the plastic layer that covers the distal end face in the protruding direction of the rib:
a lightening portion, which opens toward the end in the cell stacking direction of the cell stack, and
a plurality of cutout portions, which allows the lightening portion to communicate with the flow path.
2. The manifold according to claim 1 , wherein
the recess is formed along the opposed surface so as to extend in a flow direction of the coolant in the flow path in the recess,
the rib is formed to extend in the same direction as a direction in which the recess extends, and
the lightening portion is formed to extend along the rib.
3. The manifold according to claim 2 , wherein
the lightening portion is provided between a pair of upright walls extending in parallel with the rib in the portion of the plastic layer that covers the distal end face in the protruding direction of the rib,
the upright walls are connected together by a plurality of reinforcing portions, which are provided at intervals in an extending direction of the rib,
the lightening portion is one of a plurality of lightening portions partitioned by the reinforcing portions, and
the cutout portions are formed in the upright walls such that two or more of the cutout portions communicate with each of the lightening portions.