Patent attributes
A throttle device for an internal combustion engine includes a throttle body, a transmission mechanism and an opener. A relief spring is interleaved between the throttle body and the opener. A back spring is interleaved between a final stage gear of the transmission mechanism and the opener. Each of the relief spring and the back spring is formed of a torsion coil spring. One or each of the terminal ends of the relief spring or the back spring is bent in a radial direction with respect to an axis of a coil portion. The opener or the final stage gear has at least one spring support portion with an engaging recess. The engaging recess is configured to permit insertion of the radially bent terminal end and to permit movement of the radially bent terminal end relative to the engaging recess in a circumferential direction with respect to an axis of the coil portion. The engaging recess is engageable with the radially bent terminal end as the radially bent terminal end moves in the circumferential direction relative to the engaging recess.
