Hitachi Construction Machinery Co., Ltd.

Kcm Corporation

Noritaka Itou

Satoru Kaneko

Takashi Ikimi

Satoshi Sekino

Hidekazu Moriki

Hiroyuki Kobayashi

Masatoshi Yoshimura

Kazuo Ishida

Akinori Kamiya

Tadashi Osaka

Ken Takeuchi

Yuuichi Kunitomo

Masaki Higurashi

Katsuhiko Tokuda

Yoko Tsukada

Hiroshi Utashiro

Toshio Kotaka

Toru Kikuchi

Shota Kimura

Takashi Fujimoto

The work vehicleincludes a main controllerthat controls a travel driving force and a work driving force. The main controllerincludes a travel remaining time calculating unitthat calculates a remaining time until a target rise/run distance is reached as a travel remaining time t, a work remaining time calculating unitthat calculates a remaining time until a target arm angle is reached as a work remaining time t, a rise/run determining unitthat determines whether rise/run is being performed or not, a correction rate setting unitthat sets a travel correction rate ηthat adjusts a travel driving torque and a work correction rate ηthat adjusts a work driving torque based on the travel remaining time t, the work remaining time t, and the rise/run determination flag, and an engine torque distribution calculating unitthat calculates a travel driving torque command and a work driving torque command based on the travel correction rate ηand the work correction rate η.

Work vehicle apparatus for loading efficiency

A work vehicle includes: an engine; a hydraulic pump that is driven by the engine; hydraulic cylinders that are extended and contracted by pressurized fluid delivered from the hydraulic pump; a work device that is moved according to the extension/contraction operations of the hydraulic cylinders; a travel device that is driven independently of the work device; an electrically driven motor that is driven by electric power generated by the engine to operate the travel device; and a controller that controls the hydraulic cylinders and the electrically driven motor. The controller controls the output power of the hydraulic pump and the output power of the electrically driven motor by changing the distribution ratios of a first torque consumed by the work device and a second torque consumed by the travel device among torques output by the engine, on the basis of a reaction force received by the vehicle body.

Work vehicle having a controller that controls the hydraulic cylinders and the electrically driven motor on a basis of a distribution ratio of a first torque and a distribution ratio of a second torque

In an electric drive system in which a battery is not connected to a DC bus, even when a load on a traveling electric motor increases suddenly, it is made possible to avoid such a situation that the DC bus voltage drops to a level equal to or lower than an operating voltage of an inverter and the inverter stops working. To this end, a DC bus voltage drop prevention device controls such that, when the voltage of the DC bus drops below a first threshold value, the output torque of the traveling electric motor is decreased according to an amount of decrease in the voltage of the DC bus, and when the voltage of the DC bus drops below a second threshold voltage lower than the first threshold voltage, the output torque of the traveling electric motor is decreased to zero or a value within a range of magnitude with which a work vehicle stays stationary on a level ground.

Work vehicle

A wheel loader includes a working device, a lift cylinderwhich is a hydraulic actuator that drives the working device, a hydraulic pumpthat supplies hydraulic oil to the lift cylinder, a lift cylinder bottom pressure detectorthat detects a pressure of the lift cylinder, a control valvethat controls the amount of hydraulic oil to be supplied from the hydraulic pumpto the lift cylinder, a vehicle acceleration detectorthat detects a vehicle acceleration in a longitudinal direction, and a control device. The control devicedetermines whether the working device has started excavation, or not, based on the lift cylinder bottom pressure detected by the lift cylinder bottom pressure detectorand the vehicle acceleration detected by the vehicle acceleration detector

An object of the present invention is to provide a hybrid working vehicle that enables enhancing efficiency of an engine. A hybrid control device () according to the present invention includes a required power arithmetic unit (A) that operates power required for operation of the vehicle, specified rotational speed setting equipment (B) that sets first rotational speed and second rotational speed which specify an operating range of the engine () according to required power operated by the required power arithmetic unit (A), variable speed control equipment (B) that variably controls rotational speed of the engine () according to required power operated by the required power arithmetic unit (A) and electrical storage device electric power control equipment (C) that executes control over supplying electric power according to a deficit of power of the engine () in an electrical storage device () for required power operated by the required power arithmetic unit (A) to an electric motor () when rotational speed of the engine () variably controlled by the variable speed control equipment (B) is first rotational speed.

Hybrid wheel loader

Provided is a working machine capable of regenerating and utilizing surplus energy. The working machine related to the present invention is provided with a branching flow path () through which hydraulic oil flows between a hydraulic actuator () and a hydraulic pump-motor (), an accumulator () arranged in the branching flow path, a first opening/closing valve () arranged between the accumulator and the hydraulic pump-motor, and a second opening/closing valve () arranged between the accumulator and the hydraulic actuator. A control device () selectively introduces the hydraulic oil from the hydraulic actuator and the hydraulic oil from the hydraulic pump-motor to the accumulator and accumulates the same by controlling opening/closing of the first opening/closing valve and the second opening/closing valve.

Working machine

A hybrid wheel loader includes a control device () that estimates output power of an engine () and an electricity storage device () when the hybrid wheel loader is inferred on the basis of output values of detectors () to be traveling towards an object of excavation in order to perform an excavating work, and then, if the output power is less than target power considered necessary for the excavating work, accelerates the engine () to a target revolution speed while increasing the electric power supplied from the electricity storage device to a traveling motor (). Accordingly, power necessary for excavation can be drawn from the engine even when the engine revolution speed is low and there is a fear of power deficiency occurring at the time of the excavating work.

There are provided a work vehicle comprising a motor generator () driven by an engine, a hydraulic pump () driven by at least either of the motor generator and the engine, a work device () driven by hydraulic fluid from the hydraulic pump, a electric traction motor () driving wheels (), an electrical storage device () connected to the motor generator and to the electric traction motor and charged electrically on the basis of a target SOC; and a control device () varying the target SOC for the electrical storage device () on the basis of total demanded power (Pf+Prun) of the hydraulic pump and the electric traction motor.

Hybrid work vehicle with load dependent target state of charge

This invention includes a hydraulic pump (), a working implement () having a lift cylinder () driven by a hydraulic fluid supplied from the hydraulic pump (), an operating device () for operating the working implement (), a traveling motor () for driving wheels, and a main controller (). When the lift cylinder () fails to operate despite an extending instruction being imparted to the lift cylinder () via the operating device (), the main controller () reduces a limit value for an increase rate of a torque required in the traveling motor () to a value smaller than that applied when the lift cylinder () operates. With this configuration, occurrence of wheel slip during lifting of an object to be carried can be reduced.

Construction vehicle

A hybrid wheel loader includes: an engine that includes an output shaft; a motor/generator that includes a rotating shaft directly attached to the output shaft of the engine; a transmission that includes an input shaft attached to the rotating shaft of the motor/generator, and an output shaft; a propeller shaft disposed on an output side of the transmission and driven via the output shaft of the transmission; an electricity storage device; and a control device that stores electricity into the electricity storage device by collecting electrical energy at the motor/generator.

Growing community of inventors

Tsuchiura, Japan

Noritaka Itou