Hitachi Construction Machinery Co., Ltd.

Hidetoshi Satake

Kouji Ishikawa

Shinji Nishikawa

Shinya Imura

Takatoshi Ooki

Kazuhiro Ichimura

Manabu Edamura

Katsuaki Kodaka

Shiho Izumi

Tomoaki Kaneta

Seiji Ishida

Yusuke Kajita

Takenori Hiroki

Yukihiro Tatsuno

Yuuki Gotou

Kouichi Shibata

Yasunori Ota

Manabu Sugiura

Seiji Hijikata

Kazuo Fujishima

Tsutomu Udagawa

Eitaro Ito

Youichi Kowatari

Keiichiro Nakamura

Ken Imamura

Masatoshi Hoshino

Shinji Ishihara

Hiroaki Amano

Masataka Sasaki

Daisuke Nogami

Tomoki Kimura

Mitsuo Sonoda

Junko Suzuki

Mitsugu Ojima

Toshihiko Watanabe

Yuuji Nagashima

Hiroshi Sakamoto

Shiro Yamaoka

Akihiro Narazaki

Shinji Kato

Yasuo Okano

Nobuei Ariga

Hiroshi Onoue

Ryohei Yamashita

Tadatoshi Shimamura

Akira Nakayama

Hiroshi Tsukui

Toshihiko Ishida

Yuichi Kunitomo

Shinya Okumura

Kousaku Ohno

Yuta Nakamura

Koji Ishikawa

Shuji Egawa

Hideki Haramoto

Nobuo Uzawa

Satoshi Iwasaki

Shingo Sawada

Wataru Kondou

When option attachment has not been attached, a reserve flow/direction control valveis made to operate as a center bypass cut valve. When an option attachment has been attached, switching control is performed. In the switching control, when the option attachment is not used, the reserve flow/direction control valveis made to operate as a center bypass cut valve for adjusting composite opening area of a center bypass and thereby controlling the flow rate of hydraulic fluid flowing into an actuator. When the option attachment is used, the reserve flow/direction control valveis made to operate so as to supply the hydraulic fluid to an option hydraulic actuator

Hydraulic system for work machine

The Construction machinery includes at least two actuators, a main pump that generates hydraulic energy for driving the actuators, control valves disposed between the main pump and the actuators, a hydraulic pump motor driven by the generator motor that generates energy to be added to the hydraulic energy, and a controller that reduces hydraulic energy generated by the main pump when the hydraulic pump motor driven by the generator-motor generates energy. The construction machinery further comprises changeover valves that selectively change a location at which the energy from the hydraulic pump motor driven by the generator-motor is to be added according to the actuators. The controller changes a reduction rate of the hydraulic energy generated by the main pump depending on a specific actuator to which the energy is to be added.

Construction machinery

The hydraulic fluid energy recovery apparatus includes a fluid communication line for holding a bottom-side hydraulic fluid chamber and a rod-side hydraulic fluid chamber of a hydraulic cylinder in fluid communication with each other, a fluid communication valve connected to the fluid communication line for adjusting the pressure and/or flow rate of a hydraulic fluid passing through the fluid communication line in a manner that allows for adjustment of a degree of opening of the fluid communication valve, first pressure detecting means for detecting a signal indicative of pressure at the bottom-side hydraulic fluid chamber of the hydraulic cylinder, an amount-of-operation detecting means for detecting an amount of operation of the operating means, and a control device for capturing the signal of pressure at the bottom-side hydraulic fluid chamber of the hydraulic cylinder detected by the first pressure detecting means.

Hydraulic fluid energy recovery apparatus for work machine

The energy efficiency is increased by reducing the throttle/relief loss in the delivery flow of the hydraulic pump caused by the bleed-off control, while also making it possible to control the delivery pressure of the hydraulic pump according to the operation amount of the control lever unit and improving the operational performance. A controllerincludes a target pump pressure setting unitwhich calculates a target pump delivery pressure which increases with the increase in an operation amount signal from an operation amount detectorA/B based on the operation amount signal and a pump flow rate upper limit setting unitwhich calculates a pump flow rate upper limit which increases with the increase in the operation amount signal based on the operation amount signal. The tilt amount of the hydraulic pumpis controlled based on the target pump delivery pressure calculated by the target pump pressure setting unit, the pump flow rate upper limit calculated by the pump flow rate upper limit setting unit, and the delivery pressure of the hydraulic pumpdetected by a pressure detector

Hydraulic control device for work machine

A hybrid or battery type working machine including a hydraulic pump, an electric motor, an electric storage device, and a control device which controls a pump absorption horsepower maximum value in accordance with an amount of electricity stored in the electric storage device. The control device reduces the pump absorption horsepower maximum value by dividing the pump absorption horsepower maximum value into a plurality of regions having different target flow rates, and reduces the pump absorption horsepower maximum value from an old pump absorption horsepower maximum value corresponding to the pump absorption horsepower maximum value which has not yet been reduced to a new pump absorption horsepower maximum value corresponding to the pump absorption horsepower maximum value which has been reduced, so that temporal differences among the regions can increase in a descending order of a target flow rate.

Operating machine

A construction machine includes: a swing structure (); a hydraulic pump (); a hydraulic motor () for driving the swing structure () using hydraulic fluid from the hydraulic pump (); an electric motor () for driving the swing structure () with or without the aid of the hydraulic motor (); and a hydraulic actuator () driven by the hydraulic fluid from the hydraulic pump, the hydraulic actuator can be operated together with the swing structure (). When the swing structure () is operated together with the hydraulic actuator (), only the electric motor () is used to swing the swing structure ().

Construction machine

This invention provides a hybrid construction machine including a swing structure, a hydraulic pump, a hydraulic swing motor driving the swing structure using hydraulic fluid from the hydraulic pump, an electric swing motor driving the swing structure in conjunction with the hydraulic swing motor, a boom cylinder operated simultaneously with the swing structure at times and driven by the hydraulic fluid from the hydraulic pump, a first directional control valve controlling flow of the hydraulic fluid supplied from the hydraulic pump to the hydraulic swing motor, a second directional control valve controlling the flow of the hydraulic fluid returning from the hydraulic swing motor, and a controller and solenoid pressure reducing valves which prevent operation of the second directional control valve when the boom cylinder is operated simultaneously with the swing structure.

Hybrid construction machine

Provided is a work machine including: a variable-displacement pump; an actuatordriven by a hydraulic fluid delivered from the pump; a flow control valveof an open-center type that controls a flow rate of the hydraulic fluid supplied to the actuator; a bleed-off lineconnecting the actuator flow control valveto a tank; a bleed-off flow control valvedisposed in the bleed-off line; an operating devicethat specifies operation of the actuator; a bleed-off control devicethat controls a degree of opening of the bleed-off flow control valvein accordance with an amount of manipulation of the operating device; and a pump control devicethat controls, in accordance with the degree of opening of the bleed-off flow control valve, a pump flow rate by correcting a reference pump flow rate that is based on the amount of manipulation of the operating device. The work machine with this configuration can save energy while at the same time inhibiting an occurrence of a sense of strangeness or discomfort in particular operation.

Work machine

A construction machine is characterized by including: a track structurea swing structureprovided on the track structurein a swingable manner; swing motorsthat drive and swing the swing structure; a boomconnected to the swing structurea boom cylinderthat moves the boomvertically; a swing operation systemthat instructs a swing operation of the swing structurea boom operation systemthat instructs a vertical movement of the booma detectorthat detects a bottom pressure of the boom cylinderand a controllerthat reduces swing speed of the swing structureaccording to a signal from the detectorwith respect to a reference swing speed according to a signal of the swing operation, while signals of the swing operation and a boom raising operation are being inputted. This ensures that a load acting on the boom can be felt on the basis of motion of a front work implement, and, on the other hand, the front work implement can be operated along a locus according to operation without being affected by the load on the boom.

A work machine is adapted for reduced fuel consumption in regions where swinging by a hydraulic motor is prone to deterioration in efficiency, such as when the operating stroke of the swinging is small. The work machine includes an engine, a hydraulic pump, a swing structure, an electric motor for driving the swing structure, and a hydraulic motor for driving the swing structure, the hydraulic motor being driven by the hydraulic pump, and includes a swing control lever device that commands the swing structure to be driven. A control device operates in either an electric swing mode in which the swing structure is driven mainly by torque of the electric motor or a hydraulic swing mode in which the swing structure is driven mainly by torque of the hydraulic motor, depending on an operating stroke of the control lever device and/or a swing speed of the swing structure.

A construction machine, comprising a hydraulic pump, a swing hydraulic motor, a swing electric motor, a delivery capacity regulating device, and a control unit which controls the driving/braking of the swing structure, is configured to comprise an operation amount detection device for detecting the operation amount of the swing control lever and a speed detection device for detecting the speed of the swing electric motor. The control unit includes a hydraulic pump output reduction control unit which takes in an operation amount signal representing the operation amount of the swing control lever detected by the operation amount detection device and a speed signal representing the speed of the swing electric motor detected by the speed detection device and controls the delivery capacity regulating device by calculating a reduction rate of the output of the hydraulic pump based on the detection signals.

Provided is a hybrid-type construction machine including a swing device of the hydraulic-electric combined swing type and by which, in a work for which accurate swing operability is demanded like, for example, a crane work, a swing body is driven alone by the electric motor. The hybrid-type construction machine includes an engine, a hydraulic pump driven by the engine, a swing body, an electric motor for driving the swing body, and a hydraulic motor driven by the hydraulic pump for driving the swing body. The swing body is swung by simultaneous drive by the electric motor and the hydraulic motor. The hybrid-type construction machine includes a control apparatus having a work mode changeover unit by which an operator changes over a mode in response to an aspect of a work and an electric alone swing controlling unit configured to control the swing body to be swung by the electric motor alone. When a work in which position accuracy is demanded is selected by the work mode changeover unit, the swing body is swung by the electric alone swing controlling unit.

Hybrid-type construction machine

A construction machine including an internal combustion engine controlled based on a torque command, an electric motor mechanically connected to the internal combustion engine, and an electric energy storage device that supplies electric power to the electric motor, the construction machine performing work by driving a hydraulic pressure generator using the internal combustion engine and the electric motor, the construction machine including: a speed control device that controls a speed of the electric motor based on a speed command; and a torque limiter that limits the torque command relative to a torque target, wherein the torque command is limited by the torque limiter in such a manner that a rate of change with time of the torque command is limited to be equal to or less than a predetermined value.

An electric motor that is fixed to a revolving frame, an electrical equipment that is supported by the revolving frame by using a vibration absorption mount, and a cable for establishing a connection between the electric motor and the electrical equipment are provided. A connector mounting member having an outer shape smaller than that of a box is provided in the box of the electrical equipment, and an equipment-side connector is provided in the connector mounting member. A cable-side connector of the cable is connected to the equipment-side connector, and a cable end portion of the cable is fixed to the box by a clamp member. As a result, the vibration that is transmitted to the cable can be matched with the vibration that is transmitted to the cable-side connector.

Provided is construction machinery that is capable of greatly reducing the amount of fuel consumption by making effective use of recovered energy. The construction machinery has a first hydraulic pumpfor discharging hydraulic oil for driving an actuator, a second hydraulic pump, a second prime moverfor driving the second hydraulic pump, energy storage devicefor storing energy for driving the second prime mover, and a hydraulic oil supply circuitincluding a hydraulic oil switching sectionthat accepts the hydraulic oil discharged from the first hydraulic pump and the hydraulic oil discharged from the second hydraulic pump and supplies either the mixture of the accepted hydraulic oils or a selected one of the accepted hydraulic oils to the actuator. The construction machinery includes a control devicethat, when the drive efficiency of the second hydraulic pumpand/or the amount of energy stored in the energy storage deviceis higher than a preselected setting value, outputs a switch command to the hydraulic oil switching sectionand outputs a drive command to the second prime mover

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Ishioka, Japan

Hidetoshi Satake