THROTTLE VALVE WITH BUILT-IN MOTOR

摘要

PROBLEM TO BE SOLVED: To provide a throttle valve that improves a heat radiation characteristic of a throttle valve controlling built-in motor and prevents icing via a simple and inexpensive means. SOLUTION: The throttle valve 1 with a built-in motor controls valve travel with the motor 13 to adjust an air flow rate in an intake pipe 11 of an internal combustion engine. A yoke 14 of the motor 13 is at least partly exposed into the intake pipe 11 near a valve element 12. The structure causes an air flow in the intake pipe 11 to promote heat radiation of the motor 13 and improve a heat radiation characteristic of the motor 13, and causes heat of the motor to prevent icing. The improved heat radiation characteristic of the motor 13 can prevent a reduction in motor toque due to overheat of the motor 13, so that a small motor whose torque is smaller by a conventionally expected reduction can be set and that the overall size of the throttle valve with a built-in motor can be reduced.