Kobe Steel, Ltd.

Kobelco Construction Machinery Co., Ltd.

Kobelco Cranes Co., Ltd.

Kabushiki Kaisha Kobe Seiko Sho

The University of Tokyo

Kabushiki Kaisha Kobe Seiko Sho (kobe Steel, Ltd.)

Kochi Prefectural Public University Corporation

Naoki Sugano

Satoshi Maekawa

Naoto Hori

Takao Nanjo

Etsujiro Imanishi

Takaharu Michida

Hidekazu Oka

Kei Morita

Katsuki Yamagata

Hiroo Kondo

Takayuki Igaue

Naoya Kitazumi

Koji Inoue

Hideaki Yoshimatsu

Yoshio Inoue

Koji Ueda

Masayuki Komiyama

Yoshihiro Suda

Takahiro Kobayashi

Mitsunori Hirozawa

Yutaka Toji

Koichi Honke

Taisuke Tsunoo

Akira Tsutsui

Kazuhiko Fujii

Hiroshi Togo

Seigo Arai

Shota Oguma

Mamoru Uejima

Motomichi Sonobe

Shohei Uemura

Yuuji Matsuura

Susumu Ohmori

Takahiro c/o Okubo Plant In Kobelco Cranes Co Ltd Kobayashi

Joji c/o Okubo Plant In Kobelco Cranes Co Ltd Terasaka

Taisuke c/o Okubo Plant In Kobelco Cranes Co Ltd Tsunoo

Koichi c/o Okubo Plant In Kobelco Cranes Co Ltd Shimomura

Terasaka Joji

An energy regeneration device which can regenerate energy of a working fluid discharged from an actuator while controlling a flow rate of the working fluid, and a work machine including the device. The regeneration device includes a boom cylinder, an inertial fluid container, an oil tank, an accumulator, a low-pressure-side opening/closing device, and a high-pressure-side opening/closing device. A calculation unit calculates an opening area of each of the low-pressure-side opening/closing device and the high-pressure-side opening/closing device in accordance with a desired flow rate of a hydraulic fluid discharged from the boom cylinder. A regeneration control unit adjusts an opening area of each of the low-pressure-side opening/closing device and the high-pressure-side opening/closing device, and selects alternately the low-pressure-side opening/closing device and the high-pressure-side opening/closing device as a destination with which the inertial fluid container communicates, to supply a discharged hydraulic fluid to an accumulator.

Energy regeneration device and work machine provided with energy regeneration device

A liquid pressure rotary machine in which a rotation delay of a retainer with respect to a cylinder block is reduced and contact of pistons placed between the retainer and the cylinder block with peripheral members is suppressed is provided. A piston pump includes a rotation shaft, a cylinder block, piston heads, piston rods, a retainer, a swash plate, and a tilt adjustment mechanism. When the tilt adjustment mechanism swings the swash plate, a discharge amount of the piston pump becomes variable. The retainer to be rotated together with the piston heads and the piston rods is supported by a retainer bushing provided in the rotation shaft. By engaging ball pins of the retainer bushing with spherical surface pin grooves of the retainer, the retainer and the retainer bushing are integrally rotatable about the center axis of the rotation shaft and the retainer is swung about the spherical surface center.

Liquid pressure rotary machine

Provided are an energy regeneration device which can regenerate energy of a working fluid discharged from an actuator while controlling a flow rate of the working fluid, and a work machine including the foregoing device. The regeneration device () includes a boom cylinder (), an inertial fluid container (), an oil tank (), an accumulator (), a low-pressure-side opening/closing device (), and a high-pressure-side opening/closing device (). A calculation unit () calculates a duty ratio for opening/closing the low-pressure-side opening/closing device () and the high-pressure-side opening/closing device () in accordance with a desired flow rate of a working fluid discharged from the boom cylinder (). A regeneration control unit () selects alternately the low-pressure-side opening/closing device () and the high-pressure-side opening/closing device () as a destination with which the inertial fluid container () communicates in accordance with the calculated duty ratio, and supplies a discharged working fluid to an accumulator ().

A hydraulic rotary machine configured to reduce sliding resistance of a reciprocating piston and to suppress a reduction in volumetric efficiency corresponding to an amount of leakage of hydraulic oil. A piston pump includes a rotor shaft, a cylinder block, a piston head, a piston rod, a retainer, a swash plate, and a tilt regulation mechanism. When the tilt regulation mechanism rocks the swash plate, the amount of discharge from the piston pump is variably changed. The retainer which rotates with both the piston head and the piston rod is supported by a retainer bush provided to the rotor shaft. The retainer sphere section of the retainer and the retainer bush sphere section of the retainer bush have spherical shapes having the same curvature. During the regulation of tilt, the retainer rocks while the retainer bush sphere section is in sliding contact with the retainer bush.

Hydraulic rotary machine

An energy regeneration device capable of controlling flow of a working fluid discharged from an actuator while regenerating energy from the working fluid, and a work machine including the foregoing device, include a boom cylinder, an inertial fluid container, an oil tank, an accumulator, a low-pressure-side opening/closing device, and a high-pressure-side opening/closing device. A calculation unit calculates a duty ratio for opening/closing the low-pressure-side opening/closing device and the high-pressure-side opening/closing device in accordance with a desired flow rate of a hydraulic fluid discharged from the boom cylinder. A regeneration control unit selects alternately the low-pressure-side opening/closing device and the high-pressure-side opening/closing device as a destination with which the inertial fluid container communicates in accordance with the calculated duty ratio, and supplies the discharged hydraulic fluid to an accumulator.

Provided is an electrically-driven flow rate control valve capable of controlling a flow rate of fluid while application of a high pressure of the fluid to a sub valve body connected to an electric motor is suppressed. A flow rate control valve includes a casing, an elevation drive device, and a main valve body. When the sub valve body moves upward by the elevation drive device, oil in a back pressure chamber is discharged. Moreover, the oil in a first oil chamber flows into the back pressure chamber while the flow rate of the oil is regulated. A balance among pressures in the back pressure chamber, the first oil chamber, and the second oil chamber changes, and the main valve body opens. When the main valve body is closed, a direct application of the pressure of the back pressure chamber to the sub valve body is blocked.

Electrically-driven flow rate control valve

Provided is an electrically-driven flow rate control valve capable of controlling a flow rate of a fluid flowing between two inlet/outlet ports, restraining a high pressure of the fluid from being applied to a sub valve body connected to an electric motor. The flow rate control valve has a casing, a raising/lowering drive device, a supply-switching valve, a main valve body, a valve-closing spring. When the electric motor of the raising/lowering drive device moves the sub valve body upward, oil of a back pressure chamber is discharged from a discharge oil passage through a sub valve body communication port and a sub valve body oil passage to open the main valve body. When the main valve body is closed, a pressure of the back pressure chamber is inhibited from being directly applied to a lower end face of the sub valve body.

The energy recovery system includes an inertial fluid container, a low pressure container, a high pressure container, a low pressure valve, and a high pressure valve, a valve flow conduit, and a valve controller. The valve controller switches, in response to a decrease in volume of the fluid chamber, the inertial fluid container between communicating with the low pressure container and the high pressure container, thereby generating inertial forces of the working fluid flowing toward the low pressure container in the inertial fluid container, and causing the working fluid to flow into the high pressure container by the inertial forces. The valve controller sets a switching frequency for the valves to a frequency close to an Nth-order (where N is a natural number) anti-resonance frequency of a flow conduit for the working fluid.

Energy recovery device and energy recovery method

A hydraulic driving apparatus that drives a plurality of driving subjects and regenerates energy thereof. This hydraulic driving apparatus includes: a first pump motor; a second pump motor that is switchable between a state of moving a first driving subject by hydraulic oil discharged from the first pump motor and a state of being operated as a pump by means of energy of the first driving subject; a first pump motor line that couples the first and second pump motors with each other; a first accumulator connected to the first pump motor line; a regeneration subject hydraulic actuator that moves a second driving subject; a second accumulator that receives hydraulic oil from the regeneration subject hydraulic actuator; a second pump motor line that couples the second accumulator with the first pump motor; and a pressure release changeover valve that opens/closes the second pump motor line.

Hydraulic driving apparatus of work machine

A hydraulic drive apparatus includes: an accumulator for receiving hydraulic fluid discharged from a hydraulic actuator during a lowering drive; an accumulator flow regulator capable of changing a flow rate of hydraulic fluid to be introduced to the accumulator from a closed circuit; a regeneration actuator for converting energy of the hydraulic fluid accumulated in the accumulator into motive force; a regeneration selector valve interposed between the accumulator and the regeneration actuator; a pump control section for limiting a pump discharge flow rate during the lowering drive; and a speed control section for operating the accumulator-flow-rate regulator so as to bring an actuating speed of the hydraulic actuator close to a target speed during the lowering drive.

Hydraulic drive device

Provided is a hydraulic drive device that is provided in a work device and with which it is possible to obtain a high energy-saving effect with a low-cost configuration while being equipped with a plurality of hydraulic actuators. The hydraulic drive device is provided with: first and second actuator groups; closed circuits connected to hydraulic actuators included in the first actuator group; a pump section including closed circuit pumps; open circuits which include a plurality of variable throttle valves for changing the flow rate of working fluid supplied from a hydraulic pump included in the pump section to a hydraulic actuator; and circuit switching sections having a first state in which the closed circuits are opened and the opened circuits are blocked, and a second state in which the closed circuits are blocked and the open circuits are opened.

Work machine hydraulic drive device

Provided is a hydraulic shovel capable of moving a boom, an arm, and a bucket at respective adequate speeds even during complex operations thereof, without a significant pressure loss. This hydraulic shovel includes: a first pump () connected to a boom actuator () and a bucket actuator (); a second pump () connected to an arm actuator () and the boom actuator (); a third pump () connect to the arm actuator (); a boom control valve () interposed between the first pump () and the boom actuator (); an arm control valve () interposed between the second pump () and the arm actuator (); a bucket control valve () interposed between the first pump () and the bucket actuator (); a boom merging valve () for speed increase interposed between the second pump () and the boom actuator (); and an arm merging valve () for speed increase interposed between the third pump () and the arm actuator ().

Hydraulic shovel

Provided is a hydraulic driving apparatus including a calculation section calculating a temporary target engine rotation speed corresponding to an engine operation amount, a calculation section calculating a temporary target pump displacement volume based on first-control and second-control target pump displacement volumes corresponding to an actuator operation amount and a pump load pressure, and a command section calculating a final target engine rotation speed and a final target pump displacement volume to output commands. The command section calculates a target pump discharge amount from the temporary target engine rotation speed and the temporary target pump displacement volume, sets the final target pump displacement volume to one larger than the temporary target pump displacement volume, and sets the final target engine rotation speed to one being lower than the temporary target engine rotation speed and allowing a pump discharge amount equivalent to the target pump discharge amount to be obtained.

Hydraulic driving apparatus for working machine

Provided is a hydraulic drive apparatus for working machine capable of preventing an excessive pressure reduction on a meter-in side and moving a load in a lowering direction at a stable speed requiring no counter balance valve. The apparatus includes a hydraulic pump, a hydraulic actuator for lowering the load, an operating device, a hydraulic circuit including a meter-in flow passage, a meter-out flow passage and a regeneration flow passage, a control valve, a meter-in-flow-rate controller for controlling a meter-in flow rate, a meter-out-flow-rate controller for controlling a meter-out flow rate to one not lower than the meter-in flow rate, a back pressure generator located downstream of the regeneration flow passage in the meter-out flow passage, and a meter-out-flow-rate limiter. The meter-out-flow-rate limiter minimizes a flow passage area of the meter-out orifice when a pressure in the meter-in flow passage falls to or below a permissible pressure.

Hydraulic drive apparatus for work machine

Provided is a hydraulic drive apparatus for working machine capable of preventing an excessive pressure drop on a meter-in side and moving a load in a lowering direction at a stable speed requiring no counter balance valve, including a hydraulic pump, a first hydraulic actuator lowering a first load, an operating device, a first hydraulic circuit including meter-in and meter-out flow passages, a control valve, a meter-in-flow-rate controller, a meter-out-flow-rate controller making a meter-out flow rate not lower than a meter-in flow rate, a second hydraulic actuator, a second hydraulic circuit between the first hydraulic circuit and a tank and for the second hydraulic actuator, a back pressure valve between the second hydraulic circuit and the tank, a regeneration line leading a part of hydraulic fluid from between the second hydraulic circuit and the back pressure valve to the meter-in flow passage, and a check valve in the regeneration line.

Growing community of inventors

Kobe, Japan

Naoki Sugano