Patent ID: 8131434
Filing Date: 2012-03-06
Classification: F02D

Abstract:
1. An engine speed control system for a work vehicle, comprising: a pedal sensor for detecting an operative position of an accelerator pedal, the pedal sensor having an output thereof corresponding to the operative position of the accelerator pedal; a foot accelerator controller for carrying out a foot accelerator control, wherein during the foot accelerator control, a rotational speed of the engine corresponding to the output of the pedal sensor is used by the system as a target rotational speed; a lever sensor for detecting the operative position of an accelerator lever, the lever sensor having an output thereof corresponding to the operative position of the accelerator lever; a hand accelerator controller for carrying out a hand accelerator control, wherein during the hand accelerator control, a rotational speed of the engine corresponding to the output of the lever sensor is used by the system as the target rotational speed; an upper limit setting device for setting an upper limit rotational speed of the engine; and an upper limit rotation controller for carrying out an upper limit rotation control, wherein during the upper limit rotation control the upper limit rotational speed of the engine is used by the system as the target rotational speed, wherein the foot accelerator control is carried out by the system when the rotational speed of the engine corresponding to the output of the pedal sensor is higher than the rotational speed of the engine corresponding to the output of the lever sensor and less than the upper limit rotational speed of the engine, wherein the hand accelerator control is carried out by the system when the rotational speed of the engine corresponding to the output of the lever sensor is higher than the rotational speed of the engine corresponding to the output of the pedal sensor and less than the upper limit rotational speed, and wherein the upper limit rotation control is carried out by the system when the rotational speed of the engine corresponding to the output of the pedal sensor or the rotational speed of the engine corresponding to the output of the lever sensor is higher than the upper limit rotational speed of the engine.