Patent ID: 7040283

Claim:
A motor driving type throttle valve device comprising: a throttle body having an intake passage for introducing air to an internal combustion engine; a throttle valve rotatably mounted in the intake passage formed by said throttle body and controlling intaked air amount by changing an opening area of said intake passage; a motor for driving and rotating said throttle valve; and a spring for biasing said throttle valve from a rotating end position toward a rotating start position; wherein said intake air passage and said throttle valve have a minimum sectional area position in which the sectional area of said intake passage is minimum between said rotating start position and said rotating end position of said throttle valve, from an area in which sectional area of said intake passage increases gradually from said minimum sectional area position to said rotating start position, and from an area in which sectional area of said intake passage increases gradually from said minimum sectional area position to said rotating end position; and said throttle valve is controlled for positioning at said rotating start position by a biasing force of said spring when said motor is a state of non-energizing.