Jet pump, manufacturing method of jet pump, and fuel supply device having jet pump

A jet pump comprising a resin body that is made of resin and forms a pressurizing passage, a nozzle passage and a diffuser passage, while stored fuel, which is stored in a fuel tank, is pumped by the jet pump through the diffuser passage by discharging pressurized fuel, which is supplied to the pressurizing passage, into the diffuser passage through the nozzle passage, wherein:

• at least a part of the resin body is integrally molded to form the pressurizing passage and the nozzle passage in the part of the resin body;
• the nozzle passage includes:
• a communication passage section that is communicated with a downstream end of the pressurizing passage;
• and
• a flow restricting passage section that is communicated with a downstream end of the communication passage section and reduces a flow rate of the pressurized fuel in comparison to a flow rate of the pressurized fuel, which flows through the communication passage section;
• a common width direction, along which a passage width of the communication passage section and a passage width of the pressurizing passage are defined, is perpendicular to an extending direction of the flow restricting passage section;
• a first passage wall surface and a second passage wall surface, which define the communication passage section between the first passage wall surface and the second passage wall surface, are opposed to each other in the common width direction;
• the flow restricting passage section opens in the first passage wall surface;
• and
• the second passage wall surface is concavely curved relative to the first passage wall surface toward the flow restricting passage section, so that the passage width of the communication passage section is progressively reduced toward the flow restricting passage section within a predetermined range that is equal to or smaller than the passage width of the pressurizing passage.