摘要 |
A cooling system has a radiator for cooling coolant of an automotive engine, cooling fan for cooling the coolant in the radiator, and a thermostat for controlling coolant temperature. The thermostat has a housing having a flange, an actuating rod secured to the housing at a first end thereof, a guide member slidably mounted on the actuating rod, a resilient seal spool provided around a second end portion of the actuating rod and secured to the guide member, a heat sensitive cylinder housing the seal spool and secured to the guide member, wax pellets provided in the heat sensitive cylinder to enclose the seal spool. The flange has a hole so as to pass a coolant, and the thickness of the resilient seal spool being set between 25% and 5% of the diameter of the actuating rod, thereby reducing a spring constant of a return spring of the thermostat. A cooling fan switch is provided for starting the cooling fan at a low coolant temperature. |