Construction vehicle

摘要

A wheel loader (50) is designed so that when a specific first condition is met for vehicle speed, accelerator opening, engine speed, and HST pressure, the engine absorption torque curve of an HST pump (4) is switched to shift the matching point from the low-engine speed side to the high-engine speed side. On the other hand, if a second condition is met for vehicle speed and HST pressure, control is performed so that the absorption torque curve of the HST pump (4) is returned from the high-engine speed side to the low-engine speed side.

主权项

1. A construction vehicle comprising:
an engine; a travel hydraulic pump configured to be driven by the engine; a travel hydraulic motor configured to be driven by hydraulic fluid discharged from the travel hydraulic pump; an accelerator pedal configured to adjust an accelerator opening degree according to a pressed amount thereof; a hydraulic sensor configured to detect a pressure of the hydraulic fluid sent from the travel hydraulic pump to the travel hydraulic motor; an engine controller configured to adjust an output torque from the engine; and a controller programmed to change a matching point of an absorption torque curve for the travel hydraulic pump with respect to an output torque curve for the engine from a low-engine speed side to a high-engine speed side when a first condition is met, and to change the matching point from the high-engine speed side to the low-engine speed side when a second condition is met, the first condition being satisfied when a vehicle speed and the accelerator opening degree are prescribed values or higher, and at least one of
the engine speed is a specific value or lower,a hydrostatic transmission pressure sent from the hydraulic sensor is a prescribed value or lower, andthe output torque adjusted by the engine controller is a prescribed value or higher, and the second condition being satisfied when one of the vehicle speed, the hydrostatic transmission pressure and the output torque adjusted by the engine controller is a prescribed value or lower.