Abstract: This invention is a hydraulic work machine having an electric assist motor coupled to an engine and a hydraulic pump, in the hydraulic work machine of which, a rotational speed and torque of the engine are controlled so that an operating point of the engine moves along a predetermined route for yielding a combustion state of the engine under a transient state that the engine changes in speed and torque. A target speed and torque of the engine 7 are set so that the rotational speed and torque of the engine 7 will change along a predetermined route F in a running region of the engine, respective rates of change of the target rotational speed and torque of the engine 7 are limited, and the engine 7 is controlled to yield the target engine speed. In addition, torque of the assist motor 10 is controlled to yield the target torque of the engine.

Abstract: A control apparatus for a hybrid construction machine which can continue filter regeneration without impairing the operability as far as possible irrespective of a condition of a machine body or a power storage device is provided. The control apparatus for a hybrid construction machine includes an engine, a motor generator driven by the engine and capable of generating electric power, a hydraulic pump driven by total torque of the engine and the motor generator, a power storage device, an inverter, a filter that collects a particulate material in exhaust gas of the engine, and a control section that outputs a command signal for controlling powering operation or regeneration operation of the motor generator.

Abstract: A construction machine management system in which a failure analysis or a failure-omen diagnosis of a machine body can be performed with a high degree accuracy and at a low cost is provided. In a machine body group of construction machines including at least one representative machine body having an engine control unit that detects a cumulative stress value of a diesel engine of the construction machine and a crankcase pressure sensor that detects a crankcase pressure, and at least one general machine body that has an engine control unit but does not have a crankcase pressure sensor, a center server performs a diagnosis of an omen of a failure state regarding the crankcase pressure of the general machine body based on correlation information between the cumulative stress value and the crankcase pressure obtained from the representative machine body and the cumulative stress value of the general machine body.

Abstract: The construction machine includes: a control valve that switchingly supplies hydraulic fluid from a hydraulic pump to a hydraulic actuator; a control valve drive device that supplies pilot secondary hydraulic fluid to the control valve in accordance with an operation of an operation lever device; a pilot hydraulic pump that supplies pilot primary hydraulic fluid to the control valve drive device; a pressure accumulation device that recovers return hydraulic fluid returned from the hydraulic actuator. The construction machine further includes: a check valve provided in a line between the pilot hydraulic pump and the control valve drive device; a pressure reducing valve that supplied the hydraulic fluid accumulated in the pressure accumulation device; a flow rate reduction device; and a controller that controls the flow rate reduction device in accordance with the pressure in the line between the check valve and the control valve drive device.

Abstract: A construction machine includes an engine, a load estimation unit that estimates a pump power absorption, a regeneration/powering power demand calculation unit that calculates a regeneration/powering power demand according to a state of charge in an electrical storage device, an engine power demand calculation unit that calculates an engine power demand based on the power absorption and regeneration/powering power demand, and a motor generator control unit that performs rotational speed control or torque control. The control unit includes a control switching unit that switches the rotational speed and the torque control according to the engine power demand and the rotational speed of the engine. The control switching unit switches from the torque control to the rotational speed control when during performance of the torque control, the engine power demand increases and the rotational speed of the engine becomes lower than a predetermined rotational speed.

Abstract: In a control device for construction machinery, a system operating point calculation unit calculates a plurality of combinations of engine rotational speed and engine torque with which demanded power of an engine can be generated; and calculates system efficiency in each of the combinations according to discharge pressure of a hydraulic. A rotational speed calculation unit calculates target rotational speed of the engine as the engine rotational speed in one of the combinations of the engine rotational speed, the engine torque and the system efficiency calculated by the system operating point calculation unit that includes desired system efficiency. A displacement calculation unit calculates target displacement of the hydraulic pump based on the target rotational speed calculated by the rotational speed calculation unit and demanded flow rate of the hydraulic pump. With this control device, the engine and the hydraulic pump can be controlled at an efficient operating point.

Abstract: A vehicle control system which can ensure high reliability, real-time processing, and expandability with a simplified ECU configuration and a low cost by backing up an error through coordination in the entire system without increasing a degree of redundancy of individual controllers beyond the least necessary level. The vehicle control system comprises a sensor controller for taking in sensor signals indicating a status variable of a vehicle and an operation amount applied from a driver, a command controller for generating a control target value based on the sensor signals taken in by the sensor controller, and an actuator controller for receiving the control target value from the command controller and operating an actuator to control the vehicle, those three controller being interconnected via a network.

Abstract: The hybrid constructions machine has an engine rotation speed sensor 11A to detect a rotation speed NE of an engine 11, an engine state determination unit 20B to determine the state of output torque TE of the engine 11, a load torque estimation unit 20C to calculate load torque TP of a hydraulic pump 13, and an engine assistance limiting unit 20E to, when the rotation speed NE detected with the engine rotation speed sensor 11A is equal to or greater than a rotation speed N0, and the engine state determination unit 20B determines that the output torque TE of the engine 11 has not become minimum torque Tmin, or the load torque TP calculated with the load torque estimation unit 20C is lower than torque T1, limit motive-power assistance with the motor generator 12 to the engine 11.

Abstract: The purpose of the present invention is to operate an engine in a proper operation state while keeping the remaining amount in an electrical storage apparatus within a proper range. Hybrid construction machinery according to the present invention is provided with a controller for controlling an engine according to a governor characteristic having a predetermined inclination that defines a relationship between load torque and rotational speed so that the rotational speed decreases with an increase in the load torque.

Abstract: An object of the present invention is to provide a working machine and a working machine monitoring system using the same which is capable of improving the accuracy in determining fuel property. The working machine is provided with an engine operation parameter acquisition module (1041) that acquires an engine operation parameter representing the operation state of an engine mounted on the working machine; a refueling time acquisition module (1011) that acquires a refueling time when the working machine is supplied with fuel; and a fuel property determination module (1014) that determines the property of the fuel based on a comparison result of the time when the engine operation parameter changes, with the refueling time.

Abstract: To provide a work machine that can suppress a steep fluctuation in engine power.

Abstract: A hybrid construction machine comprises: a motor generator (2) which exchanges torque with an engine (1); a hydraulic pump (3) which is driven by at least one of the engine and the motor generator; a hydraulic actuator (5) which is driven by hydraulic fluid delivered from the hydraulic pump; an electrical storage device (10) for supplying electric power to the motor generator; and a controller (8) which sets target power of the engine and target power of the motor generator so as to satisfy demanded power of the hydraulic pump. The controller makes the setting so that the target power of the engine monotonically increases with the decrease in the remaining electric amount of the electrical storage device. With this configuration, the operator's operational feel can be kept excellent while also achieving reduction in fuel consumption and gas emission.

Abstract: To provide construction machinery capable of more efficiently utilizing the energy of return hydraulic oil from a hydraulic actuator.

Abstract: To provide a work machine that can suppress a steep fluctuation in engine power.

Abstract: The purpose of the present invention is to operate an engine in a proper operation state while keeping the remaining amount in an electrical storage apparatus within a proper range. Hybrid construction machinery according to the present invention is provided with a controller for controlling an engine according to a governor characteristic having a predetermined inclination that defines a relationship between load torque and rotational speed so that the rotational speed decreases with an increase in the load torque.

Abstract: A hydraulic working machine has an assist electric motor connected to an engine and a hydraulic pump. The emissions of air pollutants in the exhaust gas from the engine are minimized regardless of fluctuations in the load torque of the hydraulic pump. A specific revolution speed suitable for reducing the emissions of air pollutants is stored, and an engine is controlled using the specific revolution speed as a target revolution speed. The absorption torque of a hydraulic pump is subjected to high-pass filtering whereby a high-frequency component devoid of a trend component is obtained. Target assist torque is computed from the high-frequency component, and the assist electric motor is subjected to power running/generation control accordingly. A specific output torque range suitable for reducing the emissions of air pollutants is stored, and the target assist torque is corrected so that the trend component does not exceed the specific output torque range.

Abstract: An electrically driven working vehicle that requiring reduced power assistance from an electrical storage device is provided. The vehicle has an engine, a generator motor connected to the engine, a generator inverter for controlling the amount of power generated by the generator motor, a traveling motor for driving the vehicle, an electrical storage device connected to the generator inverter and the traveling motor, and a forward/reverse switching device for switching the traveling direction of the vehicle. The vehicle further includes a control device for outputting to the generator inverter an instruction to increase the amount of power generated by the generator motor when the voltage of the electrical storage device is equal to or lower than a maximum voltage level and a speed signal of the traveling motor given upon switching of the forward/reverse switching device is equal to or lower than a predetermined speed.

Abstract: Provided is a construction machine which is capable of suppressing useless power consumption. This construction machine is provided with an excavator body, a working device which is attached to the excavator body, an engine which is mounted in the excavator body, a generator motor which is attached to the engine and which can be driven as an electric generator or an electric motor, a hydraulic pump which is driven by the engine and the generator motor, a hydraulic actuator which drives the working device with motive power generated by the hydraulic pump, and a control portion which lowers the drive output of the generator motor in accordance with the drive state of the working device and limits the drive output of the hydraulic pump in order to keep the rotation frequency of the engine within a range of predetermined values.

Abstract: A hybrid work machine includes: an engine controller (14) that controls rotational speed of an engine (7) in accordance with a target rotational speed input from an EC dial (31); an assist motor (10) that generates electricity using power of the engine (7); a hydraulic pump (6) operated using power of the engine and/or of the assist motor; and a vehicle body controller (11) that estimates power (Pe) the engine is required to output when a request to generate electricity is sent to the assist motor and permits the assist motor to generate electricity only when the engine power requirement is not greater than an electricity generation threshold value (Eth1). The electricity generation threshold value (Eth1) is determined based on the power and characteristics of energy loss of the engine (7).

Abstract: A construction machine includes an engine, a load estimation unit that estimates a pump power absorption, a regeneration/powering power demand calculation unit that calculates a regeneration/powering power demand according to a state of charge in an electrical storage device, an engine power demand calculation unit that calculates an engine power demand based on the power absorption and regeneration/powering power demand, and a motor generator control unit that performs rotational speed control or torque control. The control unit includes a control switching unit that switches the rotational speed and the torque control according to the engine power demand and the rotational speed of the engine. The control switching unit switches from the torque control to the rotational speed control when during performance of the torque control, the engine power demand increases and the rotational speed of the engine becomes lower than a predetermined rotational speed.