Patent ID: 7698891
Filing Date: 2010-04-20
Classification: B60W,F16H,Y10T

Abstract:
1. A travel motion control apparatus for a hydraulically driven vehicle, comprising: a hydraulic pump that is driven by a driving motor; a travel motion motor that is driven with pressure oil supplied from the hydraulic pump; a displacement volume control device that controls a displacement volume of the travel motion motor so that the displacement volume decreases as a travel pressure of the travel motion motor decreases and the displacement volume increases as the travel pressure of the travel motion motor increases; a travel motion control valve that controls a flow rate of the pressure oil supplied from the hydraulic pump to the travel motion motor; an operation device with which the travel motion control valve is operated to generate the travel pressure according to a load in a pipeline from the travel motion control valve to the travel motion motor by the pressure oil output from the hydraulic pump, the travel pressure decreasing when the vehicle travels downhill; a rotation rate detection device that detects a rotation rate of the travel motion motor; and an over rotation prevention device that increases the displacement volume of the travel motion motor to a level equal to a predetermined value smaller than a maximum displacement volume if the rotation rate detection device detects a rotation rate equal to or higher than a predetermined rotation rate upper limit which is equal to or less than an allowable rotation rate limit of the travel motion motor, regardless of that the displacement volume control device controls the displacement volume of the travel motion motor so that the displacement volume decreases as the travel pressure generated by an operation of the operation device decreases.