Abstract: A work machine is capable of detecting an abnormality in the amount of soot in exhaust gas in an exhaust pipe upstream of an exhaust gas aftertreatment device. The work machine includes: an exhaust gas sensor which detects the amount of soot contained in exhaust gas between an engine and an exhaust gas aftertreatment device and generates a soot amount detection signal; and a controller into which the detection signal is input. The controller includes an abnormality judgment section that makes an abnormality judgment on whether or not the detected soot amount is abnormal, and a threshold setting section that sets a soot amount threshold that is a threshold for making the abnormality judgment. The abnormality judgment section judges an abnormality when the value of the soot amount corresponding to the soot amount detection signal is larger than the soot amount threshold.

Abstract: A work machine is capable of detecting an abnormality in the amount of soot in exhaust gas in an exhaust pipe upstream of an exhaust gas aftertreatment device. The work machine includes: an exhaust gas sensor which detects the amount of soot contained in exhaust gas between an engine and an exhaust gas aftertreatment device and generates a soot amount detection signal; and a controller into which the detection signal is input. The controller includes an abnormality judgment section that makes an abnormality judgment on whether or not the detected soot amount is abnormal, and a threshold setting section that sets a soot amount threshold that is a threshold for making the abnormality judgment. The abnormality judgment section judges an abnormality when the value of the soot amount corresponding to the soot amount detection signal is larger than the soot amount threshold.

Abstract: In a rotation control device for rotating a rotation motor at speed in accordance with a boom raising operation amount, at the time of a combined operation for simultaneously performing a rotation action and a boom raising action, a limitation value of rotation torque in accordance with the boom raising operation amount is determined by rotation torque limitation value setting means of a controller, the limitation value serving as a rotation torque limitation value is sent to rotation speed control means, and a command value of the rotation torque is torque-limited by rotation torque limiting means.

Abstract: An inverter is forcibly operated to supply electric power to a motor, thereby performing detection of a current leakage, on condition that a power-on operation is performed, that the motor is stopped, and that determination as to occurrence or non-occurrence of the current leakage has not yet been made even once after the power-on.

Abstract: Provided is a hybrid working machine capable of performing battery charging control both for a working period and a standby period. The hybrid working machine includes a hydraulic actuator, an engine, a hydraulic pump driven by the engine to supply hydraulic fluid to the hydraulic actuator, a battery, a generator motor connected to the engine to serve as a generator by an output power of the engine to charge the battery and serve as a motor for assisting the engine by supply of an electric power from the battery, a battery monitor detecting a battery SOC, a controller which controls a charging power of the battery depending on the battery SOC, and a working state detector detecting a working state as information for discriminating between a working period during which the hydraulic actuator is actuated and a standby period during which the hydraulic actuator is not actuated. The controller limits the charging power in the standby period in comparison with in the working period.

Abstract: In a hybrid excavator, a generator motor and a hydraulic pump are driven by using an engine as a power source. A battery is charged with power generated by the generator motor. A rotation motor is driven by the generator motor and the battery. The voltage of a DC bus is detected by a voltage sensor, and whether the battery is unusable is determined by a breakdown detector. When the battery becomes unusable, emergency evacuation control is performed so that the power consumption of the rotation motor will be suppressed to be less than or equal to the power generation of the generator motor while maintaining the DC bus voltage greater than or equal to the normal operation voltage of the system.

Abstract: An excavator has a controller capable of setting target torque of a rotation motor in accordance with a speed deviation between target speed set in accordance with an operation amount of an operating lever and actual rotation speed and is provided with an inverter for detecting necessary torque for rotating an upper rotating body, the necessary torque being changed in accordance with a working state of the upper rotating body. The controller calculates a correction amount which is increased as increasing the torque and subtracts the correction amount from the target speed so as to set new target speed. A controller sets first target torque for driving the motor and second target torque for maintaining the upper rotating body on the spot on the basis of the actual speed, and operates the motor in accordance with the torque which has a larger absolute value in the same direction as the first target torque among both the torque.

Abstract: Provided is a hybrid working machine capable of performing battery charging control both for a working period and a standby period. The hybrid working machine includes a hydraulic actuator, an engine, a hydraulic pump driven by the engine to supply hydraulic fluid to the hydraulic actuator, a battery, a generator motor connected to the engine to serve as a generator by an output power of the engine to charge the battery and serve as a motor for assisting the engine by supply of an electric power from the battery, a battery monitor detecting a battery SOC, a controller which controls a charging power of the battery depending on the battery SOC, and a working state detector detecting a working state as information for discriminating between a working period during which the hydraulic actuator is actuated and a standby period during which the hydraulic actuator is not actuated. The controller limits the charging power in the standby period in comparison with in the working period.

Abstract: There is provided a slewing control device that enables to detect breakdown of a driving system of a mechanical brake, and generate a torque for holding a slewing body in a stopped state to thereby prevent movement of the slewing body when an anomaly has occurred. In a working machine for driving a slewing body by an electric motor 1, judgment is made as to whether a mechanical brake 4 is in an inconsistent state, based on a command to be outputted to a brake circuit B, and a pressure detected by a brake pressure sensor 17. The inconsistent state is a state that the mechanical brake 4 is in a brake released state when an activation command for switching the mechanical brake 4 to a brake activated state is outputted. If it is judged that the mechanical brake 4 is in the inconsistent state, a command for obtaining a braking torque for holding the slewing body in a stopped state is outputted to the electric motor 1.

Abstract: In a construction machine in which a motor is driven by battery power through an inverter in accordance with operation of an operating lever, current-leakage detection signal output means applies a voltage signal, which is adapted for detection of a current leakage, between DC buses connected to the battery and a body of the machine. The applied signal voltage is detected by signal detection means, and the occurrence or non-occurrence of a current leakage is determined based on a crest value of the detected voltage signal. When the operating lever is operated during the determination, the determination is suspended to prevent erroneous detection.

Abstract: An inverter is forcibly operated to supply electric power to a motor, thereby performing detection of a current leakage, on condition that a power-on operation is performed, that the motor is stopped, and that determination as to occurrence or non-occurrence of the current leakage has not yet been made even once after the power-on.

Abstract: The present invention is to drive a hydraulic pump and a generator motor by an engine, to electrically charge a battery by a generator action of the generator motor, and to drive the generator motor by electric power of the battery so as to assist the engine. A governor position is changed by operations of a potentiometer for accelerator and a mode selection switch so as to control rotation speed of the engine. On the premise of the above configuration, generator output is limited by a controller at the time of accelerating the engine until the rotation speed of the engine reaches set speed determined on the basis of the operations of the potentiometer for accelerator and the mode selection switch, and hence engine load is reduced so as to assist acceleration.

Abstract: The present invention is to drive a hydraulic pump and a generator motor by an engine, electrically charge a battery by a generator operation of the generator motor, and assist the engine through driving the generator motor by electric power of the battery. On the premise of the configuration above, when a deviation between a target rotation speed of the engine and an actual rotation speed of the engine is equal to or more than a preset value, and when a residual amount of fuel is equal to or less than a preset value, it is considered to be engine failure or an operation state which is directly connected to the engine failure and an engine assisting action is automatically stopped.

Abstract: In a hybrid excavator, a generator motor and a hydraulic pump are driven by using an engine as a power source. A battery is charged with power generated by the generator motor. A rotation motor is driven by the generator motor and the battery. The voltage of a DC bus is detected by a voltage sensor, and whether the battery is unusable is determined by a breakdown detector. When the battery becomes unusable, emergency evacuation control is performed so that the power consumption of the rotation motor will be suppressed to be less than or equal to the power generation of the generator motor while maintaining the DC bus voltage greater than or equal to the normal operation voltage of the system.

Abstract: In a hybrid excavator, a hydraulic pump and a generator motor are connected in parallel to an output shaft of an engine and a rotation motor is driven by a battery. The generator motor assists the engine by performing a motor function. Power consumption of each of the hydraulic pump and the rotation motor is detected. The output of the hydraulic pump and the rotation motor is controlled such that the sum of the detected power consumption does not exceed maximum supply power set as the sum of power that can be supplied to the hydraulic pump and the rotation motor.

Abstract: Power distribution of an engine and an electric power storage device is determined according to a charge amount of the power storage device, and the charge amount of the power storage device is maintained in an adequate range. A power source device for working machines includes a hydraulic pump, a generator-motor, an engine, serving as a common power source, to which the hydraulic pump and the generator-motor are connected parallel, and a battery, serving as an electric power storage device, for storing a power thereof by the generator function of the generator-motor. The generator-motor is driven by a discharge power of the battery to perform the motor function.

Abstract: In a hybrid construction machine, its display device displays, toward an operator, an artificial engine sound serving as load information according to a magnitude of a workload, instead of an engine sound. Furthermore, the display device issues an alarm sound to surrounding workers when performing an operation by only stored electrical power of an electrical energy storage device without using an engine. In this hybrid construction machine, in addition to the issuing of alarm from the display device during the operation without using the engine, the display device issues an advance notice sound for engine restart when at least one value out of the workload and a charge amount of the electrical energy storage device has become an advance notice set value close to a set value of engine restart.

Abstract: An excavator has a controller capable of setting target torque of a rotation motor in accordance with a speed deviation between target speed set in accordance with an operation amount of an operating lever and actual rotation speed and is provided with an inverter for detecting necessary torque for rotating an upper rotating body, the necessary torque being changed in accordance with a working state of the upper rotating body. The controller calculates a correction amount which is increased as increasing the torque and subtracts the correction amount from the target speed so as to set new target speed. A controller sets first target torque for driving the motor and second target torque for maintaining the upper rotating body on the spot on the basis of the actual speed, and operates the motor in accordance with the torque which has a larger absolute value in the same direction as the first target torque among both the torque.

Abstract: The present invention is to drive a hydraulic pump and a generator motor by an engine, to electrically charge a battery by a generator action of the generator motor, and to drive the generator motor by electric power of the battery so as to assist the engine. A governor position is changed by operations of a potentiometer for accelerator and a mode selection switch so as to control rotation speed of the engine. On the premise of the above configuration, generator output is limited by a controller at the time of accelerating the engine until the rotation speed of the engine reaches set speed determined on the basis of the operations of the potentiometer for accelerator and the mode selection switch, and hence engine load is reduced so as to assist acceleration.

Abstract: The present invention is to drive a hydraulic pump and a generator motor by an engine, electrically charge a battery by a generator operation of the generator motor, and assist the engine through driving the generator motor by electric power of the battery. On the premise of the configuration above, when a deviation between a target rotation speed of the engine and an actual rotation speed of the engine is equal to or more than a preset value, and when a residual amount of fuel is equal to or less than a preset value, it is considered to be engine failure or an operation state which is directly connected to the engine failure and an engine assisting action is automatically stopped.