| 摘要 |
PURPOSE: A steering apparatus having a transmission ratio adjusting mechanism of a vehicle is provided to reduce noise generated in engaging a locking arm with a lock holder for a locking motion of a lock mechanism by a composite coil spring having a resilient member and two coil springs. CONSTITUTION: A steering apparatus(1) having a transmission ratio adjusting mechanism of a vehicle is composed of an input shaft(12a) connected to a steering wheel(10); an output shaft(12b) linked to a steerable wheel(24); a transmission ratio change mechanism(14) for changing rotation angle ratio of the output shaft for the rotational angle of the input shaft; a coupling member moving between locked and unlocked positions; a resilient member for urging elastically the coupling member toward the locked position; a solenoid for holding the coupling member in the unlocked position against elastic force of the resilient member; and a solenoid driving control unit for applying driving voltage to the solenoid to hold the coupling member disposed in the unlocked position and reducing the driving voltage by a voltage damping process before the coupling member finally reaches the locked position. When the coupling member is in the locked position, the input and output shafts are rotated integrally together. When the coupling member is in the unlocked position, the input and output shafts are separated from each other. Transmission ratio of the rotational angle of the output shaft is adjusted for the rotational angle of the input shaft by the transmission ratio change mechanism. For the voltage damping process, the solenoid generates electromagnetic force resisting the elastic force of the resilient member to decelerate movement speed of the coupling member during reaching the locked position.
|
