COOLING WATER RESERVOIR TANK CAP

摘要

The present invention provides a cooling water auxiliary tank cap. The cooling water auxiliary tank cap comprises: a cap body (10) to block a port (4) of a tank (2); a core (20) disposed on the cap body (10) and mounted on the port (4) to open and close the port (4) by the cap body (10); and an open control means (30) forming a vent pass to open a passage between the port (4) of the tank (2) and the core (20) to emit a portion of pressure inside the tank (2) when the cap body (10) and the core (20) are partially opened relative to the port (4). The cap body (10), the core (20), and the open control means (30) are injection-molded and formed from PPA which is a material having high resistance to hydrolysis.