PURPOSE: To simplify the structure by forming an auxiliary valve into a plate shape bimetal supported on a cantilever so as to seat and separate on/from the valve seat part formed in a bypass passage.
CONSTITUTION: An air hole 23 through which air can flow, even under the state seated on the valve seat part 14a, is formed on a bimetal valve element part 20a which is the tip part of an auxiliary valve 16 supported on a cantilever by the support part 14b of a control device main body 14. The opening of an auxiliary valve 16 is in a fully open state under which the bimetal valve element part 20a is separated from the valve seat part 14a by the temperature of an engine cooling water flowing in a cooling water passage 18 at the cooling time. Thereafter, when the engine temperature is increased, the opening of the control valve 15 is getting smaller gradually following the temperature rise. In the auxiliary valve 16, the valve element part 20a is getting to approach to the valve seat part 14a gradually by the heat conduction from the cooling water passage 18. After warming up, the auxiliary valve 16 is seated and an intake air is bypassed by the opening area decided by the air hole 23.
KAKINUMA HIDEO
MASUYAMA OSAMU
FUJIMORI YOSHIMASA
