Hitachi Construction Machinery Tierra Co., Ltd.

Hitachi Construction Machinery Co., Ltd.

Seiichi Kihara

Kiwamu Takahashi

Takeshi Ishii

Makoto Motozu

Shigehisa Hagura

Tomoyuki Miyata

Yuichi Ogawa

Kazuhiko Hiraoka

Teruo Irino

Yuuki Umizaki

Akira Saito

Tomoyuki Tanaka

Katsuhiro Sasaki

Kohei Urase

Yuta Furukawa

Hiroyuki Andou

Yuuta Furukawa

In a hydraulic drive system used for an electrically driven hydraulic work machine that drives a hydraulic pump by an electric motor and supplies a hydraulic fluid to plural actuators to carry out work, the power consumption of the hydraulic pump is kept from exceeding a value decided in advance. For this purpose, a controller calculates target power to be consumed by the hydraulic pump on the basis of the capacity of the hydraulic pump, the delivery pressure of the hydraulic pump sensed by a pressure sensor, and a target revolution speed of the electric motor, and limits the target revolution speed of the electric motor in such a manner that the target power falls within a range of the maximum allowable power.

Electrically driven hydraulic work machine

An upper revolving structure () of an electric hydraulic excavator () includes a revolving frame (), an operator's seat (), an electric motor (), a hydraulic pump () driven by the electric motor (), an oil tank (), and an exterior cover () disposed in the revolving frame () to cover electrical equipment including the electric motor () and hydraulic equipment including the hydraulic pump () and the oil tank (). A partitioning member () that is disposed in the revolving frame () to partition an inside of the exterior cover () into an electrical equipment room () and a hydraulic equipment room (). An electrical equipment cooling device () including an electrical equipment cooling fan () is disposed in the electrical equipment room (), and a hydraulic equipment cooling device () including a hydraulic equipment cooling fan () is disposed in the hydraulic equipment room ().

Power-operated construction machine

It is made possible to perform power reduction control during non-operation of control levers, and suppress power consumption of a power source when a control lever is moved by an erroneous operation, and thus reduce energy consumption. Accordingly, a controllerperforms the power reduction control when a non-operation time exceeds a set time after a transition is made from a state in which at least one control lever is operated to a non-operation state in which none of the control levers is operated, and the controllercancels the power reduction control when at least one control lever is operated in a state in which the power reduction control is performed. In addition, the set time is set as a first set time Tthwhen an operation time until at least one of leversandmakes a transition to the non-operation state is longer than a monitoring time Tth, and the set time is set as a second set time Tthshorter than the first set time Tthwhen the operation time until the at least one control lever makes a transition to the non-operation state is shorter than the monitoring time Tth

Construction machine

A cable support device () for supporting an intermediate part of a power supply cable () is provided with a cable stand () attached to an upper revolving structure (), an arm member () that is rotatably attached to the cable stand () to grip the power supply cable () on the tip end side and, and a locking mechanism () that is removably disposed in the cable stand () and in the arm member () to prohibit rotation of the arm member () relative to the cable stand (). Thereby, the rotation of the arm member () relative to the cable stand () is prohibited by the locking mechanism (), making it possible to prevent the power feeding cable () retained in the arm member () from contacting a cab ().

Electric construction machine

To reduce an increase in the electric power consumption of an electric motor according to the state of an electric power source at the start of driving of an actuator, and make it possible to use devices in an appropriate state in an electrically driven hydraulic construction machine including a driving system that drives a hydraulic pump by using the electric motor. For this purpose, a controllersets a target relief pressure of a relief valveto a normal relief pressure Pn (first relief pressure) when an operation lever deviceis not being operated and a storage amount SOC(t) of a battery(the state quantity of an electric power source) is equal to or larger than a threshold S, and sets the target relief pressure to a reduced relief pressure Pr(t) (second relief pressure) lower than the normal relief pressure Pn (first relief pressure) when the operation lever deviceis not being operated, and the storage amount SOC(t) of the battery(the state quantity of the electric power source) is smaller than the threshold S

Electrically driven hydraulic construction machine

An electric hydraulic excavator () includes an automotive lower traveling structure () and an upper revolving structure () mounted on the lower traveling structure () to be capable of revolving thereto. The upper revolving structure () includes a revolving frame () as a base, a counterweight () disposed on a rear side of the revolving frame (), and an electric power source () that is positioned on a front side of the counterweight () to be mounted on the revolving frame () and is power-fed from an external electric current source. The counterweight () is provided with a cable insertion hole () as disposed therein. A power feeding cable () is inserted in the cable insertion hole () for connection between the external electric current source and the electric power source ().

Swing post for a construction machine

Cover for construction machine

Hydraulic excavator

Weight for a construction machine

Growing community of inventors

Koka, Japan

Seiichi Kihara