ENGINE START SYSTEM MINIMIZING MECHANICAL IMPACT OR NOISE

摘要

An engine start system which may be employed in automotive idle stop systems. To start an engine, the system brings a pinion gear into engagement with a ring gear coupled to the engine and turns on an electric motor to rotate the ring gear through the pinion gear to crank the engine. When it is requested to start the engine during deceleration of the engine before stop thereof, the system thrusts the pinion into engagement with the ring gear and then turns on the motor to rotate the pinion gear, in other words, delays the activation of the motor until after the pinion gear has engaged the ring gear. This minimizes mechanical impact or noise arising from the engagement of the pinion gear with the ring gear and improves the reliability in engagement with the ring gear during the deceleration of the engine and durability of the system.

主权项

1. An engine start system comprising:
a motor which is energized by supply of electric power from a battery through a motor circuit to produce torque; an output shaft which rotates when subjected to the torque, as produced by said motor; a pinion gear through which the torque, as produced by said motor, is transmitted to a ring gear coupled to an engine; a pinion movable body which is movable along said output shaft together with said pinion gear; a solenoid switch which works to produce a magnetic attraction to attract a plunger to thrust said pinion gear toward the ring gear and also open or close main contacts installed in the motor circuit interlocking with movement of the plunger for cutting or supplying the electric power to said motor; a motor on-off relay which has relay contacts disposed in the motor circuit and opens or closes the relay contacts electrically; a controller which electrically controls an operation of said solenoid switch and an operation of said motor on-off relay when the engine is restarted during deceleration of the engine prior to stop of the engine; and delay means for delaying a second operation time that is a time when said motor on-off relay is to be energized until after a first operation time that is a time when said solenoid switch is to be energized when the engine is restarted, said delay means producing a time lag between the first and second operation times so as to turn on said motor on-off relay to supply the electric power to said motor after said pinion gear is moved by said solenoid switch to the ring gear and then engages the ring gear at least partially or to a maximum movable position where engagement of said pinion gear with the ring gear is to be established and then engages the ring gear, and after the main contacts are closed.