Komatsu Corporation

Hiroaki Inoue

Jun Morinaga

Tadashi Kawaguchi

Nobuo Matsuyama

Satoru Nishimura

Masao Fukuda

Masahiro Ikeda

Masanori Ikari

Hiroshi Yoshida

Hikosaburo Hiraki

Mitsuo Yabe

Noboru Kanayama

Tomoya Watanabe

Kouya Iizuka

Koichiro Itow

Hideaki Saito

In the working machine, first and second pilot flow paths are directly or indirectly connected to a tank flow path (). A first restrictor is disposed between the first pilot flow path and the tank flow path. A second restrictor is disposed between the second pilot flow path and the tank flow path. An actuator control unit is configured to control an actuator based on a hydraulic pressure detected by a first hydraulic pressure detector unit and that detected by a second hydraulic pressure detector unit sensor.

Working machine

An engine control apparatus includes a hydraulic pump driven by an engine, a hydraulic actuator to which pressure oil discharged form the hydraulic pump is supplied, an operation lever configured to operate the hydraulic actuators, a detection means detecting operation amounts of operation lever means, an target flow rate calculation unit () calculating an target flow rate of the hydraulic pump based on the operation amount of the operation lever, a first target speed calculation unit () calculating a first target speed of the engine according to the target flow rate, a pump output limit value calculation unit () limiting the maximum target speed of the engine in an relief operation according to a load pressure of the hydraulic pump, a fourth engine target speed calculation unit ().

Engine control apparatus

A work machine includes: hydraulic actuators, and; a capacitorfor storing electric power when a generator motoroperates as a generator and for supplying electric power when the generator motoroperates as a motor; and a swing electric motor, the hydraulic actuators, andand the swing electric motorare operated by operation of operating levers. The work machine includes an idling stop control unitfor stopping the idling of an engineand retains the swing electric motorin an operation prohibited state at least on the condition that stored voltage of the capacitoris predetermined voltage or higher when the neutral states of the operating leverscontinue for a predetermined stop time during operation of the engine

Work machine

An engine control apparatus includes an engine target speed set unitsetting a first target speed through a throttle dial, a relief engine maximum speed calculation unitcalculating a second target speed limiting a maximum target speed in a relief operation according to a load pressure of a hydraulic pump, a speed control means controlling an engine speed such that the engine speed is equal to lower one of the first target speed and the second target speed, a determination means determining whether an engine torque assist action of a generator motor is performed, based on a deviation between an target speed and a real speed of the engine. When the determination means determines that the engine torque assist action is performed, the speed control means controls the engine speed to be equal to the target speed through the engine torque assist action of the generator motor.

A method of controlling a hybrid construction machine capable of preventing a system from being rendered inoperative without increasing a capacitance of a capacitor and of inhibiting delay of a swing operation relative to an operation command at the time of swing operation, and the hybrid construction machine are provided. For this purpose, at the time of discharge of the capacitor, actual torque command values are respectively generated by referring to an assist torque limit value corresponding to capacitor voltage of a generator motor and a swing power running torque limit value corresponding to the capacitor voltage of a swing motor, as well as, at the time of charge of the capacitor, an actual target output value of the generator motor is generated.

Method of controlling hybrid construction machine and hybrid construction machine

An object of the present invention is to operate the working machine etc. with satisfactory responsiveness as intended by the operator while enhancing engine efficiency, pump efficiency, and the like, where a first engine target revolution ncomadapted to a current pump target discharge flow rate Qsum is set, and when determined that the current pump target discharge flow rate Qsum is greater than a predetermined flow rate (10 (L/min)), a revolution nM (e.g., 1400 rpm) greater than an engine low idle revolution nL is set as a second engine target revolution ncomdetermining that operation leverstoswitched from a non-operation state to an operation state. The engine revolution is controlled so that the second engine target revolution ncomis obtained if the second engine target revolution ncomis equal to or greater than the first engine target revolution ncom

Control device of engine, control device of engine and hydraulic pump, and control device of engine, hydraulic pump, and generator motor

The present invention provides a construction machine where overheating of mounted electric devices can be prevented properly with a simple structure and a method of controlling the construction machine. For this purpose, a pump target discharge flow rate of a hydraulic pump is calculated based on an operated amount of an operating unit, a temperature of an electric device mounted on the construction machine is detected, an engine minimum speed, which is a minimum possible speed of an engine in carrying out low-speed matching for matching output of the engine and pump absorbing horsepower of the hydraulic pump to each other in a low-speed region where speed of the engine is lower than set speed, is calculated by using the detected temperature of the electric device, and a maximum value out of a corresponding speed of the pump target discharge flow rate and the engine minimum speed is generated as a candidate for an engine target speed.

Construction machine and method of controlling construction machine

A power generation control method of a hybrid construction machine capable of maintaining voltage of a capacitor in an appropriate range while minimizing capacitance of the capacitor and of surely preventing a system from being rendered inoperative, and the hybrid construction machine are provided. For this purpose, swing power corresponding to electric power consumed by a swing motor for swinging a part of a body relative to other parts is sequentially calculated, a value of the calculated swing power is converted to a smaller value, a power generation command of a generator motor is sequentially generated using the converted value, and the generated power generation command is output to an inverter for driving the generator motor.

Power generation control method of hybrid construction machine and hybrid construction machine

A speed of a hydraulic actuator is matched with that of an electric actuator when the hydraulic actuator and the electric actuator are concurrently actuated. When determination units () determine that a boom hydraulic cylinder () and a rotation generator motor () are concurrently actuated based on a controlled variable of a boom control lever () and a controlled variable of a rotation control lever (), a torque of the rotation generator motor () is restricted based on a pump discharge pressure (Pp). Therefore, for example, a torque limit command is generated and output such that a torque limit value (TL) of the rotation generator motor () is decreased with a decrease in discharge pressure (Pp) of a hydraulic pump ().

Control apparatus for work machine

In a swing control device installed in an electric rotary excavator (a construction machine), when a leading edge or a trailing edge of a lever signal is sharp due to a quick operation of a swing lever, a gradient as a rise time Taor a fall time Tbis provided to the leading edge or the trailing edge of the torque output and the acceleration that are output based on the lever signal so as to somewhat ease the edge. With the arrangement, an impact in acceleration or deceleration of a rotary body can be suppressed. Specifically, a gradient in the acceleration operation is provided such that the rise time Tabecomes 0.15 seconds or more, while a gradient in the stop deceleration operation is provided such that the fall time Tbbecomes 0.1 seconds or more.

Swing control device and construction machinery

A control deviceof an electric rotary excavator generates a rotation speed coefficient in accordance with a setting condition of a fuel dialand a selection condition of a mode selection switchand changes a value of a target speed command value based on the rotation speed coefficient to change a rotation speed of a rotary bodyAccordingly, when the engine speed becomes low through operation of the fuel dialor the mode selection switch, the rotation speed of the rotary bodycan be decreased accordingly, while when the engine speed becomes high, the rotation speed can be increased accordingly. Therefore, the operation feeling substantially similar to a conventional arrangement for hydraulically rotating the rotary bodycan be obtained, so that the operator is not confused when the operator shifts excavators from the conventional hydraulic excavator to the electric rotary excavator.

Rotation control device, rotation control method and construction machine

In stopping a rotary body of an electric rotary excavator (a construction machine), a control-system changing unit of a rotation control device changes a control law from a speed control law to a position control law when a target speed is judged to be smaller than a speed threshold value. By changing to the position control, a larger braking torque can be output to an electric motor as compared with that in the speed control, thereby reliably maintaining the rotary body in a stationary state.

Fan shroud for construction machinery

A cylinder driving system capable of reducing the number of hydraulic devices and the amount of energy loss and an energy regenerating method thereof are provided. To this end, the system includes i) a hydraulic cylinder, ii) a hydraulic pump having three suction/discharge ports of a first port for supplying oil to a bottom chamber of the hydraulic cylinder or draining oil from the bottom chamber, a second port for draining oil from a head chamber of the hydraulic cylinder or supplying oil to the head chamber, and a third port for draining oil from a tank or supplying oil to the tank, the suction rate or the discharge rate in the first port being the sum of the respective discharge rates or suction rates in the second port and the third port, and iii) a driving source for driving the hydraulic pump.

Cylinder driving system and energy regenerating method thereof

An apparatus, for controlling a plurality of hydraulic motors and a clutch for driving a drive shaft, can prevent a speed change shock and a load slip of a hydraulic motor as well as making a structure simple. The apparatus includes: a first volume variable hydraulic motor (,), connected to the drive shaft (,) through the clutch (,); a second volume variable hydraulic motor (,), which is always connected to the drive shaft (3); first tilt rotation control means (,), for controlling a tilt rotation amount (a discharge volume cc/rev) of the first hydraulic motor by receiving a drive side pressurized oil (Pac) of the first hydraulic motor; and a zero tilt rotation holding means (,A), for holding the tilt rotation amount of the first hydraulic motor at substantially zero in a state wherein the tilt rotation amount of the first hydraulic motor is controlled to be substantially zero.

Growing community of inventors

Hiratsuka, Japan

Hiroaki Inoue