Wheel loader and control method for wheel loader

摘要

A level selecting unit is a device for selecting a tractive force level from a plurality of levels when a velocity stage of a transmission is a first velocity. The plurality of levels includes at least a first level and a second level. A control unit controls the engine. When the velocity stage of the transmission is the first velocity and the first level is selected, the control unit controls the engine on the basis of a first tractive force characteristic. The first tractive force characteristic prescribes a relationship between the vehicle speed and the tractive force of the vehicle. When the velocity stage of the transmission is the first velocity and the second level is selected, the control unit controls the engine on the basis of a second tractive force characteristic. The tractive force is reduced more in the second tractive force characteristic than in the first tractive force characteristic.

主权项

1. A wheel loader comprising:
an engine; a hydraulic pump driven by the engine; a work implement having a bucket and driven by hydraulic fluid discharged from the hydraulic pump; traveling wheels driven by the engine; a travel drive device configured and arranged to transmit driving power from the engine to the traveling wheels, the travel drive device including a torque converter and a transmission, the transmission including at least a first-speed gear and a second-speed gear; a level selecting unit for selecting a tractive force level of the wheel loader when the transmission is in the first-speed gear, the tractive force level being selectable from among a plurality of levels including at least a first level and a second level; and a control unit for controlling the engine, the control unit being configured to
control the engine on the basis of a first tractive force characteristic that prescribes a first relationship between a vehicle speed and a tractive force of the vehicle when the transmission is in the first-speed gear and the first level is selected; andcontrol the engine on the basis of a second tractive force characteristic that prescribes a second relationship between the vehicle speed and the tractive force of the vehicle when the transmission is in the first-speed gear and the second level is selected, the second tractive force characteristic having a tractive force that is reduced in comparison with the first tractive force characteristic.