INTERNAL COMBUSTION ENGINE COOLING DEVICE

摘要

[Problem] To obtain a thermostat device with which it is possible to dull the thermosensitivity of a thermo-element thermosensitive component to coolant water and better control the opening and closing of a main valve at a selected timing by means of an electrical heater. [Solution] A thermostat device (1) comprises: a piston (3); a cylinder container (4) which operates forward and reverse with respect to the piston and further comprises a flange valve which opens and closes a main flow path of coolant water; a thermal expansion body (W) which causes the cylinder container to operate forward and reverse upon the piston with a volumetric change commensurate with a temperature change within said cylinder container; and a thermo-element assembly body (10) which is disposed within the piston and further comprises a heat emitting element (H) which applies heat to the thermal expansion body by a supply of electricity. An insulating cover (20) is disposed which is formed to cover the exterior side portion of the cylinder container which faces the coolant water. Additionally, a resinous insulating material (21) and/or an atmosphere layer (22) are selectively disposed on the interior side of the insulating cover between said insulating cover and the exterior side face of the cylinder container.