Komatsu Corporation

Koji Ohigashi

Kimihiro Mori

Kazuki Kumagai

Takashi Kawakami

Kenzo Kimoto

Teruhisa Hanafusa

Shinobu Kitayama

A work machine includes first and second hydraulic motors, first and second hydraulic pumps provided to supply hydraulic oil in correspondence with the first and second hydraulic motors, respectively, first and second swash plate angle sensors provided in correspondence with swash plates which regulate amounts of delivery by the first and second hydraulic pumps, respectively, the first and second swash plate angle sensors each detecting an angle of the swash plate, a delivery amount setting unit which sets an ideal amount of delivery by the first and second hydraulic pumps, and a command value control unit which corrects a command value for adjusting an angle of the swash plate such that the amount of delivery in accordance with a result of detection by the first and second swash plate angle sensors is set to the ideal amount of delivery.

Work machine and method of controlling work machine

An engine output control unit of a work vehicle is configured to set a target rotation speed of an engine by using an engine output torque curve, to control an output of the engine. The engine output control unit is configured to control the output of the engine so as to set torque to be higher than torque at an actual rotation speed obtained using the engine output torque curve. Typically, when the actual rotation speed of the engine becomes smaller than the target rotation speed, the engine output control unit sets an engine output torque curve that is greater in torque at the actual rotation speed than the engine output torque curve, and switches control of the output of the engine from control performed using the engine output torque curve to control performed using the engine output torque curve.

Work vehicle and method of controlling engine output

A work vehicle detects pressure of hydraulic oil supplied to an arm cylinder. The work vehicle determines operation details for an arm. The work vehicle includes a relief valve capable of setting a relief pressure of hydraulic oil in a hydraulic circuit at one of a first set pressure and a second set pressure that is greater than the first set pressure. The work vehicle sets the relief pressure of the relief valve at the first set pressure, on the conditions that the detected pressure is equal to or greater than a predetermined value, and that it is determined that the operation details indicate an excavation operation. The work vehicle sets the relief pressure of the relief valve at the second set pressure when the conditions are not satisfied.

Work vehicle and method of controlling operation

An arm includes an arm main body, a protective member, a fixing component and a restrictor. The arm main body has a distal end part with first and second end components disposed a specific space apart along a width direction, a bucket attached to the arm main body, and a proximal end part configured to allow attachment on a vehicle main body side. The protective member covers the specific space. The fixing component is disposed on a proximal end part side of the specific space and fixes the protective member to the arm main body. A restrictor is disposed between the first and second end components along the width direction, and restricts movement of the protective member. A work vehicle includes a vehicle main body and the arm. A work implement includes a boom pivotably attachable to a vehicle main body and the arm attached to the boom.

Work implement, arm, and work vehicle

In construction machinery, control is conducted to keep a work machine to operate at a constant speed regardless of the operation thereof. Different engine output lines T-Tand pump torque lines M-Mare defined for different operation types. All the matching points of the engine output lines T-Tand pump torque lines M-Mdesignate a constant engine speed N. One engine output line and one pump torque line are selected according to the operation type presently selected. An output horsepower of the engine is controlled on an equal horsepower line corresponding to a sum of a horsepower for an auxiliary machine and a horsepower at a matching point of the selected lines. The pump torque for the work machine is controlled on the selected pump torque line. The engine operates at a constant speed Neven when the operation type varies or the horsepower for the auxiliary machine changes.

Growing community of inventors

Hirakata, Japan

Koji Ohigashi