An engine control system controls a work machine including an engine, a fuel injection device that injects fuel into the engine, and a hydraulic pump that is driven by the engine. The rotation state amount specification unit specifies a rotation state amount related to rotation of the engine. The injection amount determination unit determines a fuel injection amount by the fuel injection device based on the rotation state amount.

An engine control system controls a work machine including an engine, a fuel injection device that injects fuel into the engine, and a hydraulic pump that is driven by the engine. The rotation state amount specification unit specifies a rotation state amount related to rotation of the engine. The injection amount determination unit determines a fuel injection amount by the fuel injection device based on the rotation state amount.

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.

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.

An oil-pressure driving system includes a variable displacement oil-pressure pump, tilting angle adjuster, electric motor, and control device. In the control device, a target assist torque calculating portion calculates a target assist torque, a first torque limiting portion limits the target assist torque to an output value that is a virtual limit value or less, and a drive control portion controls the electric motor such that the electric motor outputs a command torque corresponding to the output value. Further, in the control device, a torque deficiency calculating portion calculates a torque deficiency by subtracting the output value from the target assist torque, a tilting angle calculating portion calculates a tilting angle command value by which the output torque of the oil-pressure pump is reduced by the torque deficiency, and a tilting angle control portion outputs a tilt signal corresponding to the tilting angle command value to the tilting angle adjuster.

An oil-pressure driving system includes a variable displacement oil-pressure pump, tilting angle adjuster, electric motor, and control device. In the control device, a target assist torque calculating portion calculates a target assist torque, a first torque limiting portion limits the target assist torque to an output value that is a virtual limit value or less, and a drive control portion controls the electric motor such that the electric motor outputs a command torque corresponding to the output value. Further, in the control device, a torque deficiency calculating portion calculates a torque deficiency by subtracting the output value from the target assist torque, a tilting angle calculating portion calculates a tilting angle command value by which the output torque of the oil-pressure pump is reduced by the torque deficiency, and a tilting angle control portion outputs a tilt signal corresponding to the tilting angle command value to the tilting angle adjuster.

A general-purpose engine control device capable of improving operation efficiency when transferring a liquid using a plurality of liquid pumps and containers. In a liquid transfer system that transfers water of a river to a container by way of a liquid pump, a container, a liquid pump, and a liquid pump in this order, an engine device has a communication interface for performing communication with another engine device, and transmits, after the driving of a liquid pump is started, start instruction information instructing the start of driving a liquid pump to an engine device installed next to the liquid pump on a downstream side in a water transferring direction on the basis of information indicating a driving record of the liquid pump. In an engine pump having received the start instruction information, the driving of the liquid pump is started.

A general-purpose engine control device capable of improving operation efficiency when transferring a liquid using a plurality of liquid pumps and containers. In a liquid transfer system that transfers water of a river to a container by way of a liquid pump, a container, a liquid pump, and a liquid pump in this order, an engine device has a communication interface for performing communication with another engine device, and transmits, after the driving of a liquid pump is started, start instruction information instructing the start of driving a liquid pump to an engine device installed next to the liquid pump on a downstream side in a water transferring direction on the basis of information indicating a driving record of the liquid pump. In an engine pump having received the start instruction information, the driving of the liquid pump is started.

A driving stage of a servo valve, including a hydraulic ejector and a hydraulic receiver able to be moved relative to each other, one of the two hydraulic units being integral with a mobile unit, movable relative to a body of the servo valve through actuation means, characterized in that the actuation means comprise two piezoelectric actuators connected in series. Control device comprising a servo valve comprising such a driving stage.

A driving stage of a servo valve, including a hydraulic ejector and a hydraulic receiver able to be moved relative to each other, one of the two hydraulic units being integral with a mobile unit, movable relative to a body of the servo valve through actuation means, characterized in that the actuation means comprise two piezoelectric actuators connected in series. Control device comprising a servo valve comprising such a driving stage.