US Patent 7156074 Throttle device

With the throttle apparatus of the present invention having a throttle valve 30 disposed at an intake passage, a throttle shaft 240 to open and close the throttle valve 30, a DC motor 51 to drive the throttle shaft 40, and so on, a second drive means 60 is disposed to exert return force to the throttle shaft 40 only for returning the throttle valve 30 to the rest position. With this structure, since return force is not exerted with a normal operation, load to the DC motor 51 is decreased, and an open-close operation can be preformed smoothly. By returning the throttle valve to the rest position utilizing other means than spring force, load to the motor is decreased, and open-close operation is smoothed.