Hitachi Construction Machinery Co., Ltd.

Zenyaku Kogyo Kabushiki Kaisha

Naoki Fukuda

Masatsugu Arai

Takaaki Tanaka

Toshiyuki Matsuno

Seiichiro Kawashima

Kenichi Saitoh

Mitsuhiro Kadota

Masaya Higashi

Yoshimasa Yamaguchi

Tadashi Osaka

Takanobu Ikari

Atsushi Kitaguchi

Yukiaki Shimizu

Shintarou Tanaka

Ryuji Kouno

Satoru Kaneko

Akihiro Nakamura

Takashi Ikimi

Hiroaki Yamazaki

Takayoshi Nakamura

Shinji Sugimoto

Takayuki Sato

Takayuki Satou

Jun Ikeda

Yuuichi Kunitomo

Hideshi Kobayashi

Tomonori Takada

Kazuhiro Imaizumi

Yukio Oku

Masataka Konishi

To provide an electric vehicle capable of reducing heat generation of the switching elements while achieving energy saving, the electric vehicle includes: an engine; a first generatordriven by the engine; a first rectifier circuitconnected to the output of the first generator; a first DC lineto receive the DC output of the first rectifier circuit; a driving motorconnected to the first DC line; a power converterconfigured to convert voltage of the first DC line; a second DC lineto receive the DC output subjected to voltage conversion by the power converter; an auxiliary deviceconnected to the second DC line; and a controllerconfigured to control the power converter. The controller is configured to, in response to the voltage Vof the first DC line becoming equal to or less than a first threshold V, control the output power Pof the power converter to a rated power P, and in response to the voltage becoming larger than the first threshold, control the output power Pto be smaller than the rated power.

Electric vehicle

When regeneration operation is being performed, electric power on a main-machine side is supplied to an auxiliary-machine side, a voltage on the auxiliary-machine side is controlled to become a first voltage value predetermined on the basis of operating voltage specifications of an auxiliary apparatus, a generator on the auxiliary-machine side is deactivated to stop supply of electric power to the auxiliary-machine side, and electric power on the auxiliary-machine side is supplied to a power storage apparatus. When the regeneration operation is ended, the supply of the electric power from the main-machine side to the auxiliary-machine side is stopped, the generator on the auxiliary-machine side is activated, the generator on the auxiliary-machine side is controlled such that a voltage on the auxiliary-machine side becomes the first voltage value, electric power of the power storage apparatus is supplied to the auxiliary-machine side, and the voltage on the auxiliary-machine side is controlled to become a second voltage value higher than the first voltage value. This enables reduction of fluctuations of a voltage supplied to auxiliary machines at a time of switching of regeneration operation by travel motors.

Regenerative braking system, and electrically driven work vehicle using the same

A power regeneration devicethat converts the power of a main engine DC lineconnected to a main engine power generatorthrough a rectification circuitto supply the converted power to an accessory DC lineconnected to an accessory power generatorthrough a rectification circuitincludes a plurality of power conversion modulestoN configured such that input sectionstoNa are connected in series. The main engine power generatorand a power consumption deviceare controlled such that a voltage input to the power regeneration devicedoes not exceed a voltage upper limit value Vm and a portion between a positive electrode terminal (+) and a negative electrode terminal (&#x2212;) of each of the input sections of the power conversion modules to be stopped is short-circuited by a bypass device and the voltage upper limit value Vm is decreased when some of the plurality of power conversion modulestoN are stopped. With this configuration, operational continuity can be improved while a device size increase is prevented.

Regenerative braking system and electrically-driven work vehicle using regenerative braking system

A hydraulic drive fan control device is provided with a variable displacement hydraulic pump, a hydraulic motor, a hydraulic drive fan that is driven by the hydraulic motor, a flow amount control valve, a rotational speed detector that detects a rotational speed of an engine, and a controller. The controller outputs a first valve control signal to the flow amount control valve and outputs a first pump control signal to the hydraulic pump to rotate the hydraulic drive fan at a first rotational speed, and outputs a second valve control signal to the flow amount control valve and outputs a second pump control signal to the hydraulic pump, thereby stopping the rotation of the hydraulic drive fan.

Hydraulic drive fan control device

A power regeneration system of a work vehicle includes: a first generator () and a second generator () that are driven by an engine (); a first electric circuit (C) for supplying electric power to traveling motors (L,R); a second electric circuit (C) for supplying electric power to an auxiliary device (); a voltage step down converter () providing electric power from the first electric circuit to the second electric circuit; and a controller () that determines whether a travel mode of the work vehicle is a powering mode or a regeneration mode in order to control driving of the voltage step down converter. If the travel mode is the regeneration mode, the controller provides the regenerative power from the first electric circuit through the voltage step down converter to the second electric circuit, in order to drive the auxiliary device with the regenerative power.

Power regeneration system of work vehicle

To provide a power regeneration system for a working vehicle that can effectively use a regenerative electric energy. A first electric circuit for supplying an electric power generated by the first generator to a traveling motor, a voltage detector for detecting an actual voltage of the first electric circuit, a second electric circuit for supplying an electric power generated by a second generator to an auxiliary device, a step-down device connected to the first electric circuit and the second electric circuit, and a controller are provided. The controller estimates the voltage of the first electric circuit after a predetermined time has elapsed from the present time, based on information on a traveling state of a work vehicle and the actual voltage detected by the voltage detector, and outputs a drive command to the step-down device when the estimated voltage is equal to or more than a threshold.

Power regeneration system for work vehicle

A dump truckincluding: an engine; a generatordriven by the engine; and a pair of driving wheelsL andR arranged to the left and right of a vehicle body frameincludes: a traveling electric motorL including a plurality of electric motorsLa,Lb, andLc that are coupled to the driving wheelL and simultaneously drive the driving wheelL; and a traveling electric motorR including a plurality of electric motorsRa,Rb, andRc that are coupled to the driving wheelR and simultaneously drive the driving wheelR. Thereby, drive systems corresponding to loads of dump trucks or the like can be configured using identical components.

Electrically driven work vehicle, and wheel electric driving unit

In a regenerative braking device of a dump truck comprising an engine, a first generator and a second generator driven by the engine, at least one travel motor driven by generated electric power of the first generator and at least one fan motor to which generated electric power of the second generator is inputted via a first rectifier circuit, the regenerative braking device comprises: a resistive element to which regenerating electric power from the at least one travel motor in regenerative braking is supplied and which is cooled by at least one fan driven by the at least one fan motor and converts electric energy into heat energy and dissipates heat; and a DC/DC converter that inputs a part of the regenerating electric power which is supplied to the resistive element to an output line of the first rectifier circuit via a second rectifier circuit.

Regenerative braking device and dump truck

Provided is a clutch control device for a work machine capable of controlling a fan to an appropriate rotational speed. In the clutch control device for the work machine, a controller includes a target fan rotational speed calculation module that calculates a target fan rotational speed for the fan, a clutch characteristic curve storage module that stores a plurality of clutch characteristic curves, a clutch command calculation module that outputs with reference to a clutch characteristic curve a first clutch control signal corresponding to the target fan rotational speed, a feedback control module that output a second clutch control signal based on the difference between the target fan rotational speed and an actual fan rotational speed, and an adder that adds the first clutch control signal and the second clutch control signal to output a third clutch control signal.

Clutch control device for work machine

Heterocyclic compound represented by the formula I wherein represents or the like; Rrepresents hydrogen atom, C-Calkyl or benzyloxy; Rrepresents methyl or nil; Rrepresents hydrogen atom, C-Calkyl, C-Calkenyl, C-Ccycloalkyl or &#x2014;CHR[wherein Rrepresents phenyl (which may be substituted with C-Calkyl, halogen atom or cyano)] or thienyl; Rrepresents C-Calkyl, C-Calkenyl, C-Ccycloalkyl or &#x2014;CHR[wherein Rrepresents phenyl (which may be substituted with C-Calkyl, halogen atom or cyano), naphtyl or thienyl]; or Ris coupled with R.

Heterocyclic compounds and cerebral function improvers containing the same as the active ingredient

Heterocyclic compound represented by the formula I wherein represents  or the like; Rrepresents hydrogen atom, C&#x2013;Calkyl or benzyloxy; Rrepresents methyl or nil; Rrepresents hydrogen atom, C&#x2013;Calkyl, C&#x2013;Calkenyl, C&#x2013;Ccycloalkyl or &#x2014;CHR[wherein Rrepresents phenyl (which may be substituted with C&#x2013;Calkyl, halogen atom or cyano)] or thienyl; Rrepresents C&#x2013;Calkyl, C&#x2013;Calkenyl, C&#x2013;Ccycloalkyl or &#x2014;CHR[wherein Rrepresents phenyl (which may be substituted with C&#x2013;Calkyl, halogen atom or cyano), naphtyl or thienyl]; or Ris coupled with R.

Azaindolizinone derivatives and cerebral function improvers containing the same as the active ingredient

Thioquinolone compounds which have useful pharmaceutical activity

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Tsuchiura, Japan

Naoki Fukuda