A low idling controller (26A) switches an idling state flag from “clear” to “set” upon detecting a non-operation of an operating device (14). A rotational speed controller (26B) switches a rotational speed command from a set rotational speed by a rotational speed command device (27) to a low idling rotational speed based upon the idling state flag. At this time, an engine (8) drives in the low idling rotational speed lower than the set rotational speed. A gate controller (24) stops switching of an inverter (23) while the low idling controller (26A) is lowering a rotational speed of the engine (8).

The present disclosure relates to a power distribution architecture for an off-road vehicle. The power distribution architecture includes a work circuit and a propel circuit and is configured for facilitating bi-directional power exchange between the work circuit and the propel circuit.

To provide a technique where a case of shutting off a battery shutoff switch while a key switch is on is detected, and a warning according to a risk can be issued at time of restart.

A construction machine includes: the key switch, an engine start switch, an engine stop switch, a notification device, a controller, and the battery shutoff switch. The controller chronologically stores operation histories of the key switch, engine start switch, and engine stop switch in a history storage section in a non-volatile manner. The controller determines, on the basis of the stored operation history, a risk content in a case of shutting off the battery shutoff switch while the key switch is on. In a case where, the controller is restarted by resuming the battery shutoff switch and turning on the key switch, the controller controls the notification device so that the notification device issues a warning according to the risk content, on the basis of a result of the determination.

A work machine includes an engine for driving a primary working unit. At least one hydraulically powered auxiliary working unit is powered by a hydraulic pump. The engine and an electric motor both provide power to the hydraulic pump via a planetary gear set which sums the power inputs from the engine and the electric motor. The pump speed of the hydraulic pump is thereby decoupled from the engine speed of the engine.

A plus-side main connection line (17) connects electrical equipment (11), (12) to a plus terminal (16A) of a battery (16). A plus-side isolating switch (18) is provided in the plus-side main connection line (17) to connect or disconnect the electrical equipment (11), (12) and or from the plus terminal (16A) of the battery (16). A plus-side auxiliary connection line (20) connects a communication terminal (15) to the plus terminal (16A) of the battery (16) in a position upstream of the plus-side isolating switch (18). A minus-side main connection line (22) connects a minus terminal (16B) of the battery (16) to ground. A minus-side isolating switch (23) is provided in the minus-side main connection line (22) to connect or disconnect the minus terminal (16B) of the battery (16) and or from the ground.

To achieve saving of fuel consumption and noise reduction by adopting a hybrid type and miniaturizing an engine and to ensure safe and reliable battery charging in a case in which a charge amount of a battery is quite insufficient, a hydraulic work machine includes: a gate lock sensor (28); a forced charging switch (41); a work machine monitor (43) that notifies an operator that a charging rate of a battery (33) falls to be lower than a critical charging rate; and a machine controller (46). The machine controller (46) actuates a generator motor (31) as a generator to forcedly charge the battery (33) when a gate lock lever (26) is operated to a lock position (D), an engine control dial (12) designates a low idle engine speed, and the forced charging switch (41) is operated.

An HCU (37) includes a battery low temperature reducing output calculating section (71A) that determines, when it is determined that an electricity storage device (31) is in a low temperature state by a battery temperature Tb, a battery low temperature reducing output PbL that is made to a larger value as the battery temperature Tb is lower, a hydraulic oil low temperature reducing output calculating section (71B) that determines, when it is determined that hydraulic oil is in a low temperature state by a hydraulic oil temperature To, a hydraulic oil low temperature reducing output PoL that is made to a larger value as the hydraulic oil temperature To is lower, and an output command calculating section (80) that controls a vehicle body operation based upon a sum of the battery low temperature reducing output PbL and the hydraulic oil low temperature reducing output PoL.

An excavator comprising: a power supply that converts AC power supply voltage from a commercial power supply into DC power supply voltage; a battery that charges or discharges power from the power supply; an inverter that converts DC power supply voltage to AC power supply voltage; an electric motor that has power supplied thereto, and is controlled, by the inverter; a first electrical circuit that supplies power to the inverter from the power supply; a second electrical circuit that joins from the battery to the first electrical circuit; an inverter relay arranged between the inverter and a junction point between the first electrical circuit and the second electrical circuit; a battery relay arranged between the junction point and the battery; and a power supply relay arranged between the junction point and the power supply.

An engine cooling system (22) includes an engine (11), an engine cooling pipe line (23), an engine water pump (24) and an engine radiator (25). An electricity storage device cooling system (27) includes an electricity storage device (19), an electricity storage device cooling pipe line (28), an electricity storage device water pump (29) and an electricity storage device radiator (31). Different heat-transfer media (engine cooling water and electricity storage device cooling water) flow respectively in the engine cooling system (22) and the electricity storage device cooling system (27). Further, a heating heat exchanger (32) is provided in the halfway of the engine cooling pipe line (23) and in the halfway of the electricity storage device cooling pipe line (28) for performing heat exchange between the engine cooling water and the electricity storage device cooling water.

Electro-hydraulic work vehicle system having a hydraulic lift mechanism comprising a first electric machine, a first hydraulic machine operatively connected to the first electric machine. A load holding valve is switchable between a first position in which it retains pressurized fluid in the hydraulic lift mechanism and a second position in which it enables pressurized fluid to flow between the first hydraulic machine and the hydraulic lift mechanism. A pressure relief valve is switchable between a first, initial position in which it prevents pressurized fluid from flowing from the first hydraulic machine to the hydraulic tank and a second position in which it enables pressurized fluid to flow from the first hydraulic machine to the hydraulic tank. An hydraulic energy storage is hydraulically connected between the first hydraulic machine and the relief valve, wherein in decent mode of hydraulic lift mechanism, the hydraulic system is configured to supply pressurized fluid to the hydraulic energy storage and when the load-holding valve is at its second position and the pressure relief valve is at its first position, wherein pressurized fluid from the hydraulic lift mechanism is capable of driving the first hydraulic machine which can drive the first electric machine to create electricity that can be stored in the electrical energy storage, and/or is capable of charging the hydraulic energy storage.