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Boat engine idling revolution number control device and method

  • US 9,638,114 B2
  • Filed: 01/13/2015
  • Issued: 05/02/2017
  • Est. Priority Date: 07/03/2014
  • Status: Active Grant
First Claim
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1. A boat engine idling revolution number control device, comprising:

  • an engine revolution number detecting section for detecting a revolution number of an engine to be mounted in a boat;

    an engine temperature detecting section for detecting a warmed-up state of the engine;

    an idling operation state detecting section for detecting an idling operation state of the engine;

    a neutral switch for detecting whether a shift position state of the engine is neutral, or forward or reverse; and

    a control unit for performing control so as to converge the engine revolution number to a target revolution number when an engine state of the engine is an idling state, the engine state being defined by results of the detections by the engine revolution number detecting section, the engine temperature detecting section, the idling operation state detecting section, and the neutral switch,the control unit comprising;

    a simulated boat-speed calculating function section for calculating a simulated boat speed based on the engine revolution number and the shift position state;

    a decelerating running determining section for calculating one of a deviation and a ratio of the simulated boat speed with respect to a target boat speed corresponding to a target revolution number during idling to determine whether the engine is being rotated by a propeller or is rotating by itself depending on a running state of the boat based on a result of the calculation;

    a basic torque-rate calculating function section for calculating a basic torque rate, which is a rate of a torque to be generated to a maximum torque of the engine and is necessary for the engine to steadily operate at the target revolution number while the engine is in the idling state, based on the shift position state detected by the neutral switch, the warmed-up state of the engine detected by the engine temperature detecting section, and the target revolution number;

    a revolution number feedback correction calculating function section for outputting a revolution number feedback correction signal for correcting the basic torque rate so as to eliminate a deviation between the target revolution number and the engine revolution number;

    a torque-rate learning correction calculating function section for calculating a torque-rate learning correction signal based on the revolution number feedback correction signal;

    a running-load correction calculating function section for calculating a running-load correction signal for correcting the basic torque rate in accordance with a result of the determination by the decelerating running determining section and the shift position state detected by the neutral switch;

    a target torque-rate calculating function section for calculating a target torque rate based on the basic torque rate, the revolution number feedback correction signal, the torque-rate learning correction signal, and the running-load correction signal;

    a target air-amount calculating function section for calculating a target air amount necessary to generate the target torque rate; and

    an intake air-amount adjusting function section for adjusting an intake air amount to be supplied to the engine based on the target air amount,wherein the running-load correction calculating function section resets the running-load correction signal to zero when detecting, based on a behavior of the engine revolution number after a running-load correction is performed, that the engine revolution number is larger than a threshold value calculated based on the target revolution number and the engine revolution number increases.

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