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

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.

Abstract: A hybrid construction machine according to the present invention includes a controller for controlling an engine with a droop characteristic. The controller includes: a target engine output calculation unit (2-4) that calculates a target output of the engine; a target speed setting unit (2-7) that sets a target speed command of a motor-generator; a target droop calculation unit (2-8) that obtains an intersection point of a constant output line with the target output value of the engine and a constant speed line with the target speed command of the motor-generator on a speed-torque characteristic diagram, and determines a governor characteristic of the engine so that the governor characteristic passes through the intersection point; a governor characteristic changing unit (2-10) that changes the governor characteristic of the engine; and a motor-generator control unit (2-9) that controls the motor-generator in accordance with the target speed command value.

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: To provide a construction machine that appropriately sets the magnitude of an engine output for each work mode. A construction machine according to the present invention includes: an engine (22); a generator-motor (23) configured to generate electric power by the engine; a hydraulic pump (41) configured to be driven by the engine and the generator-motor; a hydraulic actuator (32, 34, 36) that drives and operates a working device (30) with the power of the hydraulic pump; an electric storage device (24) for supplying electric power to drive the generator-motor and charging the electric power generated by the generator-motor; a work-mode selecting device (45, 46) that selects a work mode corresponding to operation of an operator; and an engine-output setting unit (403, 405, 407) that sets the magnitude of the output of the engine corresponding to the work mode selected by the work-mode selecting device.

Abstract: Provided is a construction machine which is capable of suppressing useless power consumption. This construction machine is provided with an excavator body (2), a working device (30) which is attached to the excavator body (2), an engine (22) which is mounted in the excavator body (2), a generator motor (23) which is attached to the engine (22) and which can be driven as an electric generator or an electric motor, a hydraulic pump (41) which is driven by the engine (22) and the generator motor (23), a hydraulic actuator (32) which drives the working device (30) with motive power generated by the hydraulic pump (41), and a control portion (80) which lowers the drive output of the generator motor (23) in accordance with the drive state of the working device (30) and limits the drive output of the hydraulic pump (41) in order to keep the rotation frequency of the engine (22) within a range of predetermined values.

Abstract: Provided is a hybrid construction machine together with a method for controlling that construction machine in a manner ensuring the operability of its combined operations regardless of fluctuations in the load on its work machine.

Abstract: A hybrid construction machine according to the present invention includes a controller for controlling an engine with a droop characteristic. The controller includes: a target engine output calculation unit (2-4) that calculates a target output of the engine; a target speed setting unit (2-7) that sets a target speed command of a motor-generator; a target droop calculation unit (2-8) that obtains an intersection point of a constant output line with the target output value of the engine and a constant speed line with the target speed command of the motor-generator on a speed-torque characteristic diagram, and determines a governor characteristic of the engine so that the governor characteristic passes through the intersection point; a governor characteristic changing unit (2-10) that changes the governor characteristic of the engine; and a motor-generator control unit (2-9) that controls the motor-generator in accordance with the target speed command value.

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 hybrid-driven hydraulic work machine maintains the torque of the engine at a prescribed value when the load on a hydraulic pump is higher than the rated power of the engine and the electric assist motor assists the torque of the engine. Control of the engine revolution speed is based on the target revolution speed of the engine; engine load calculation; and at least one of: electric motor power running calculation which calculates a differential revolution speed between the target engine revolution speed and the revolution speed of the engine and performs power running control on the electric assist motor depending on the differential revolution speed when the engine load is a prescribed value or higher; and a hydraulic pump absorption torque calculation which performs reduction control on absorption torque of the hydraulic pump depending on the differential revolution speed when the engine load is a prescribed value or higher.

Abstract: In a hybrid construction machine, there is provided a drive control device which realizes in, as a simple a structure as possible, control means of a motor generator, which is capable of preventing rapid decreases in the state of charge. The control means, which calculates a motor torque command value to be output to the motor generator, is characterized by calculating the motor torque command value, based on a difference between an actual state-of-charge and a prescribed target state-of-charge and a torque margin obtained by a difference between a maximum torque of an engine determined based on an actual rotational speed of the engine and an actual torque of the engine.

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: A hybrid-driven hydraulic work machine maintains the torque of the engine at a prescribed value when the load on a hydraulic pump is higher than the rated power of the engine and the electric assist motor assists the torque of the engine. Control of the engine revolution speed is based on the target revolution speed of the engine; engine load calculation; and at least one of: electric motor power running calculation which calculates a differential revolution speed between the target engine revolution speed and the revolution speed of the engine and performs power running control on the electric assist motor depending on the differential revolution speed when the engine load is a prescribed value or higher; and a hydraulic pump absorption torque calculation which performs reduction control on absorption torque of the hydraulic pump depending on the differential revolution speed when the engine load is a prescribed value or higher.