Patent ID: 8342284
Filing Date: 2013-01-01
Classification: B60W,F16H

Abstract:
1. A work vehicle comprising: an engine; a hydraulic pump that is a variable displacement hydraulic pump driven by the engine; a drive circuit through which flows hydraulic fluid discharged by the hydraulic pump; a hydraulic motor driven by hydraulic fluid supplied via the drive circuit; a drive wheel driven by the hydraulic motor; a forward/backward switching member configured to be operated in order to indicate a switch between forward and backward drive of the vehicle; a forward/backward detector configured to detect whether the vehicle is moving forward or backward; a pump displacement control part configured to control the displacement of the hydraulic pump so that drive circuit hydraulic pressure, which is the pressure of the hydraulic fluid driving the hydraulic motor, does not surpass a predetermined cutoff pressure; a vehicle speed detector configured to detect vehicle speed; and a cutoff-pressure-setting part configured to set the cutoff pressure to a predetermined first pressure value when the vehicle speed is greater than a predetermined first speed threshold, and to set the cutoff pressure to a value greater than the first pressure value when the vehicle speed is equal to or less than a predetermined second speed threshold that is less than the first speed threshold; wherein the cutoff-pressure-setting part is configured to set the second speed threshold to a predetermined first value when forward drive is indicated by the forward/backward switching member and the forward/backward detector detects that the vehicle is moving forward, or when backward drive is indicated by the forward/backward switching member and the forward/backward detector detects that the vehicle is moving backward, and the cutoff-pressure-setting part is configured to set the second speed threshold to a second value that is smaller than the first value when forward drive is indicated by the forward/backward switching member and the forward/backward detector detects that the vehicle is moving backward, or when backward drive is indicated by the forward/backward switching member and the forward/backward detector detects that the vehicle is moving forward.