×

Engine automatic-stop/restart system

  • US 8,419,592 B2
  • Filed: 10/21/2011
  • Issued: 04/16/2013
  • Est. Priority Date: 05/17/2011
  • Status: Expired due to Fees
First Claim
Patent Images

1. An engine automatic-stop/restart system that automatically stops an engine when an automatic stopping condition is satisfied while a vehicle travels and then restarts the engine when a restarting condition is satisfied, the engine automatic-stop/restart system comprising:

  • a starter motor that is energized to rotate;

    a pinion gear provided on the rotor shaft of the starter motor;

    a ring gear provided on the crankshaft of the engine;

    a solenoid that is energized to be biased;

    a plunger that pushes out the pinion gear in the axis direction thereof when the solenoid is energized, so that the pinion gear engages with the ring gear;

    a crank angle sensor that detects a crank angle of the engine and outputs a crank angle signal;

    a fuel injection device that injects fuel into the engine;

    a forward clutch that transmits torque produced by the engine to a transmission;

    a first control system that connects a power source with the starter motor in response to a first drive signal so as to energize the starter motor and connects the power source with the solenoid in response to a second drive signal so as to energize the solenoid;

    a second control system that controls the fuel injection device to make the fuel injection device inject fuel into the engine when the engine that has automatically stopped is restarted, that outputs the first drive signal to the first control system when the rotation speed of the engine is lower than a predetermined value, and that outputs the second drive signal to the first control system so as to energize the solenoid when the absolute value of a rotation-speed difference between an engine rotation speed calculated based on the cycle of the detected crank angle signal and the rotation speed of the pinion gear becomes smaller than a rotation speed difference threshold value at which the pinion gear and the ring gear can engage with each other; and

    a third control system that is configured in such a way as to control the coupling degree of the forward clutch so that the rotation speed of the engine can be controlled, when the engine, which cannot autonomously rotate only with fuel supply, is restarted and the rotation speed of an input shaft of the transmission is the same as or higher than the engine rotation speed, and that releases the forward clutch after the pinion gear and the ring gear have engaged with each other.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×