THERMOSTAT, WATER COOLING DEVICE, WATER COOLING ENGINE, AND OUTBOARD ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a thermostat capable of preventing a frame of the thermostat from contacting with a housing inner surface forming a coolant passage.SOLUTION: A thermostat 36 includes: an annular flange 38 which is enclosed by a cylindrical large diameter part 59b of an inner surface 59 and extends in a radius direction R; and a frame 39 extending from the flange 38 in an axial direction X. The thermostat 36 includes a seal member 40 which seals an area between the flange 38 and the inner surface 59. The seal member 40 includes: an annular outer peripheral part 61 which is sandwiched between the inner surface 59 and a thermostat cover 58 in the axial direction X at the inner side of the large diameter part 59b; and multiple protruding parts 62 which extend from the outer peripheral part 61 to the outer side in the radial direction R toward the large diameter part 59b. The thermostat 36 is disposed in a housing 37 which forms a part of a coolant passage 23 with the cylindrical inner surface 59 and opens and closes the coolant passage 23 according to a temperature of a coolant in the coolant passage 23.