To provide a throttle opening detection device allowing reduction of size in a thickness direction of a case to allow miniaturization.
This detection device has the case 2 installed to a handle bar 3 of a motorcycle; a throttle grip 1 installed to the tip side of the handle bar 3 from the case 2, rotatable to the handle bar 3; a drive gear 5 housed in the case 2, rotating to the same direction as the throttle grip 1 interlockingly with the throttle grip 1; a detecting gear 7 meshing with the drive gear 5 and rotating; and a throttle opening sensor 8 detecting a rotation angle of the detecting gear 7. The drive gear 5 and the detecting gear 7 comprise bevel gears (rotational direction variable means), and the detecting gear 7 rotates to a direction nearly perpendicular to a rotation direction of the drive gear 5.
HAYASHI NORIO
SUZUKI MICHIYUKI
KAWAMURA MASAHIRO
ASAHI DENSO CO LTD