Patent ID: 7757486
Filing Date: 2010-07-20
Classification: E02F,F02D,Y10T

Abstract:
1. An engine control device for a work vehicle, comprising: a hydraulic pump driven by an engine; a hydraulic actuator driven with pressure oil supplied from the hydraulic pump; a control valve that controls flow of the pressure oil from the hydraulic pump to the hydraulic actuator in accordance with operation of an operating member; a drive disallowing device that disallows drive of the hydraulic actuator with the pressure oil supplied in accordance with the operation of the operating member from the hydraulic pump; a disallowed drive detection device that detects whether or not the drive disallowing device is disallowing the drive; a rotation rate command issuing device that issues a command indicating a rotation rate to be achieved for the engine within a range, a lower limit of which is equal to a low idle rotation rate, in response to an operation performed by an operator, with the low idle rotation rate being a minimum rotation rate at which the hydraulic actuator can still be driven; and a rotation rate control device that executes control so as to adjust an engine speed to a low rotation rate, which is lower than the low idle rotation rate and at which an engine stall will occur if a load is applied to the hydraulic actuator, when the disallowed drive detection device detects that the drive disallowing device is disallowing the drive and the rotation rate command issuing device issues a command indicating the low idle rotation rate, and when the rotation rate command issuing device issues a command indicating a rotation rate higher than the low idle rotation rate, the rotation rate control device controls the engine speed so as to adjust the engine speed to the rotation rate indicated in the command, wherein: the rotation rate control device controls the engine speed to the low idle rotation rate when the disallowed drive detection device detects that the drive disallowing device is not disallowing the drive while the engine speed is controlled to the low rotation rate; and when the rotation rate command issuing device issues a command indicating a rotation rate higher than the low idle rotation rate while the engine speed is controlled to the low rotation rate, the rotation rate control device adjusts the engine speed to the rotation rate indicated in the command, and then the rotation rate control device maintains the engine speed to be the rotation rate indicated in the command even if the disallowed drive detection device detects that the drive disallowing device is not disallowing the drive.