Wheel loader

摘要

An engine control device of the wheel loader includes a travelling state detecting unit for detecting a travelling state of the wheel loader, a mode switching determining unit, an acceleration speed detecting unit and a switching time controlling unit. The acceleration speed detecting unit detects the acceleration speed of the wheel loader when the mode switching determining unit determines that it is required to switch between the engine output modes from a low output mode to a high output mode based on a detection result of the travelling state detecting unit. The switching time control unit controls the switching time from start to end of mode switching to be: a first time when the acceleration speed detected by the acceleration speed detecting unit is either 0 or negative; and a second time greater than the first time when the detected acceleration speed is positive.

主权项

1. A wheel loader having a low output mode and a high output mode as engine output modes, the wheel loader comprising:
an engine; a transmission having an output shaft; an output shaft rotational speed sensor configured and arranged to detect a rotational speed of the output shaft; a driving wheel; a power transmission device configured to transmit driving force from the engine to the driving wheel; a work implement configured to be driven by the driving force from the engine; and an engine control device configured to execute a mode switching control of switching between the low output mode and the high output mode, the engine control device being configured and arranged to receive a detection signal from the output shaft rotational speed sensor, the engine control device comprising a microcomputer programmed to include
a travelling state detecting unit configured to detect if the wheel loader is in a hill-climb travelling state;a mode switching determining unit configured to determine that it is required to switch from the low output mode to the high output mode upon the travelling state detecting unit detecting that the wheel loader is in the hill-climb traveling state;an acceleration detecting unit configured to detect an acceleration of the wheel loader upon the mode switching determining unit determining that it is required to switch between the engine output modes due to the wheel loader being in the hill-climb travelling state; anda switching time controlling unit configured to set a mode switching time in accordance with the acceleration detected by the acceleration detecting unit, the switching time controlling unit setting the mode switching time to
a first time if the acceleration detected by the acceleration detecting unit is either 0 or negative, indicating the wheel loader has shifted from flatland travelling to hill-climb traveling, anda second time greater than the first time if the acceleration detected by the acceleration detecting unit is positive, indicating that the wheel loader has started moving on a hill from a stopped state, the engine control device being configured to execute the mode switching control such that a time from start to end of the mode switching control is equal to the mode switching time set by the switching time controlling unit upon the traveling state detecting unit detecting that the wheel loader is in a hill-climb travelling state.