Patent ID: 7997350

Claim:
A motor grader comprising: an engine; a wheel configured and arranged to be rotatably driven by a driving force from the engine; a driving force-transmitting mechanism configured and arranged to transmit the driving force from the engine to the wheel, the driving force-transmitting mechanism having a first clutch and a second clutch configured and arranged to be driven by hydraulic pressure; a working equipment cylinder configured and arranged to be driven by hydraulic pressure; a blade configured and arranged to be driven by the working equipment cylinder; a cylinder-hydraulic-pressure-detecting section configured and arranged to detect the hydraulic pressure supplied to the working equipment cylinder; and a control section configured to determine that the motor grader is in a running state when the cylinder hydraulic pressure detected by the cylinder-hydraulic-pressure-detecting section is less than a predetermined threshold value, and to use an engagement side running-hydraulic-pressure waveform corresponding to the running state to control the hydraulic pressure supplied to the first clutch and to use a disengagement side running-hydraulic-pressure waveform corresponding to the running state to control the hydraulic pressure supplied to the second clutch during a shift operation that requires the first clutch be engaged and the second clutch be disengaged in the running state, and that the motor grader is in a working state when the cylinder hydraulic pressure is greater than or equal to the threshold value, and to use an engagement side working-hydraulic-pressure waveform corresponding to the working state to control the hydraulic pressure supplied to the first clutch and to use an disengagement side working-hydraulic-pressure waveform corresponding to the working state to control the hydraulic pressure supplied to the second clutch during a shift operation that requires the first clutch be engaged and the second clutch be disengaged in the working state.