US 2014/0371995 A1Published application

Work machine

AssigneeHitachi Construction Machinery Co., Ltd.

InventorsTsutomu Udagawa, Kazuo Fujishima, Koji Ishikawa, Hidetoshi Satake, Yuichi Kunitomo

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Abstract

There is provided a hydraulic excavator including a hydraulic pump (6) driven by an engine (7), a boom cylinder (3a) driven by hydraulic fluid delivered from the hydraulic pump (6), a swing motor (16) driven electrically, an operating device (4A) for operating the boom cylinder (3a), an operating device (4B) for operating the swing motor (16), and a vehicle body controller (11) which limits the power of the swing motor (16) in accordance with the operation amount of the operating device (4A) when the two operating devices (4A, 4B) are operated in combination. The power limit value of the swing motor (16) varies depending on the output of the engine (7). This allows a good operational feeling to be retained in combined operation regardless of the operating state of the engine.

Claims4

Dependent claims

A work machine comprising:

an engine (7);
a hydraulic pump (6) driven by the engine;
a hydraulic actuator (3a) driven by hydraulic fluid delivered by the hydraulic pump;
an electric actuator (16) driven electrically;
a first operating device (4A) which operates the hydraulic actuator;
a second operating device (4B) which operates the electric actuator, and
a control device (11) which controls a force or a torque generated by the electric actuator and a speed of the electric actuator to be lower than respective limit values of the force or the torque and the speed, wherein
the control device calculates a power limit value of the electric actuator in accordance with the operation amount of the first operating device when the first and second operating devices are operated in combination, and
the control device maintains the power of the electric actuator at the power limit value when the force or the torque generated by the electric actuator and the speed of the electric actuator are smaller than the respective limit values.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/367,000Filed 18 Dec 2012
Priority: JP 2011-28212522 Dec 2011
Published: 18 Dec 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification25 codes

B60L 58/12
For monitoring or controlling batteries: responding to state of charge [SoC]
B60L 7/14
Dynamic electric regenerative braking: for vehicles propelled by AC motors
B60L 15/2009
For control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed: for braking
B60L 50/61
Using power supplied by batteries: by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles