Valve device

A valve device comprising:

• a housing that is made of resin and forms a flow passage which is configured to conduct a fluid;
• a boss that is shaped in a tubular form and is injection molded integrally with the housing;
• a ring member that is press-fitted to and is held by an inner peripheral wall of the boss;
• a shaft that is placed on a radially inner side of the ring member and is configured to be rotated about a central axis of the boss, wherein the shaft extends in an axial direction of the central axis in the flow passage;
• a movable valve that is coupled to a portion of the shaft and is configured to be rotated about the central axis in response to rotation of the shaft, wherein the movable valve is configured to adjust a size of a cross-sectional area of a passage opening formed at a portion of the flow passage;
• a plurality of gate marks each of which is a trace of a site of the housing where molten resin is injected at a time of injection molding of the housing, wherein each of the plurality of gate marks is formed at a corresponding location of the housing which is offset from the central axis of the boss;
• and
• a plurality of ribs that radially inwardly project from the inner peripheral wall of the boss, wherein each of the plurality of ribs is placed at a corresponding location of the boss which is between corresponding circumferentially adjacent two of the plurality of gate marks, wherein:
• the boss has a plurality of reinforced portions, at each of which a corresponding one of the plurality of ribs is placed, and a plurality of unreinforced portions, at each of which none of the plurality of ribs is placed.