Abstract: An electrically driven construction machine is provided in which, in a case where a plurality of electrically driven construction machines operate simultaneously, it is possible to avoid exceeding the allowable electric power that can be output by the electric power receiving facility of a commercial electric power supply. A controller computes an own demanded power Pd1 for driving the plurality of hydraulic actuators, on the basis of operation signals of the operation devices, computes an allowable power as a power limit value usable by the electric motor on the basis of the own demanded power, the demanded powers of the other electrically driven construction machines received through the communication device, and an allowable electric power of the electric power receiving facility of the commercial electric power supply, and controls the electric motor such that a power consumption of the electric motor does not exceed the allowable power.

Abstract: In a hydraulic excavator including a track structure, a swing structure swingably disposed on an upper portion of the track structure, a work implement coupled to the swing structure, an earth removal device including a blade coupled to the track structure and a lift cylinder configured to raise and lower the blade, an operation sensor configured to detect an operation of a travelling lever, a height sensor configured to measure a height of the blade with respect to the track structure, an antenna for a satellite positioning system, the antenna being mounted on the swing structure, and a controller configured to calculate positional data regarding the blade, the controller is configured to determine a travelling operation on the basis of a signal of the operation sensor, calculate a travelling direction of straight forward travelling of the track structure as an orientation of the track structure when the straight forward travelling of the track structure is detected from a trajectory of the antenna with a st

Abstract: To provide a work machine having a blade provided to a track structure, and a swing structure provided swingably on the upper side of the track structure, which work machine allows for computation of the horizontal coordinates of the blade. The work machine includes: a swing-structure-position acquiring device that acquires a horizontal coordinate and an orientation of the swing structure; a swing sensor that senses a swing of the swing structure; a travel sensor that senses travelling of the track structure; and a controller that computes an orientation of the track structure, and a horizontal coordinate of the blade.

Abstract: A controller calculates the ratio between the sum of estimated demanded powers of a plurality of first actuators and the sum of estimated demanded powers of a plurality of second actuators, and calculates, on the basis of the ratio, first and second command values for adjusting allocation between a first allowable torque of a first pump and a second allowable torque of a second pump, and first and second regulators adjust the first and second allowable torques, on the basis of first and second output pressures of first and second torque control valves, such that the first and second allowable torques become values to which a predetermined allowable torque is allocated according to the ratio described above, and control the delivery flow rates of the first and second pumps such that the respective consumed torques of the first and second pumps do not become larger than the first and second allowable torques.

Abstract: To reduce an increase in the electric power consumption of an electric motor according to the state of an electric power source at the start of driving of an actuator, and make it possible to use devices in an appropriate state in an electrically driven hydraulic construction machine including a driving system that drives a hydraulic pump by using the electric motor.

Abstract: An electric hydraulic excavator (1) includes an automotive lower traveling structure (2) and an upper revolving structure (3) mounted on the lower traveling structure (2) to be capable of revolving thereto. The upper revolving structure (3) includes a revolving frame (5) as a base, a counterweight (13) disposed on a rear side of the revolving frame (5), and an electric power source (9) that is positioned on a front side of the counterweight (13) to be mounted on the revolving frame (5) and is power-fed from an external electric current source. The counterweight (13) is provided with a cable insertion hole (16) as disposed therein. A power feeding cable (12) is inserted in the cable insertion hole (16) for connection between the external electric current source and the electric power source (9).

Abstract: An upper revolving structure (4) of a hydraulic excavator (1) includes a revolving frame (7), a counterweight (8), an operator's seat (12), a right front cover (17B) disposed from the right side of the operator's seat (12) toward a front end side of the revolving frame (7), a control valve device (18), and an accumulator (21). An accumulator support device (23) is provided between the operator's seat (12) and the right front cover (17B), the accumulator support device (23) is configured by a box (24) providing the inside thereof for an accommodating space (25) and having an opening (26) and a lid member (28) mounted on the box (24) through a hinge member (29) and opened and closed between an open position at which the side of a free end (28D) opens the opening (26) and a closed position at which the side of the free end (28D) closes the opening (26), and the accumulator (21) is mounted on the lid member (28).

Abstract: A hydraulic drive system for a work machine including a hydraulic energy recovery device that is configured to perform load sensing control and accumulates hydraulic fluid that returns from a hydraulic cylinder in operation of lowering a front work implement into an accumulator includes, in order to prevent, when operation other than operation of lowering the front work implement is to be performed, hydraulic energy accumulated in the accumulator from being consumed uselessly, a regeneration selector valve in a hydraulic line for regenerating the hydraulic fluid accumulated in the accumulator into a hydraulic fluid supply line of a main pump. The regeneration selector valve is controlled such that, only when saturation occurs with the main pump, flow from the accumulator to the hydraulic fluid supply line is permitted.

Abstract: A controller mounted on a small-sized hydraulic excavator includes an engine restart section that restarts an engine when a horn switch operation determining section determines that a horn switch is operated and a gate lock lever position determining section determines that a gate lock lever is at a lock position in a case where a restart standby time determining section determines that restart standby time does not yet elapse after the engine is automatically stopped by an idling stop function, and a power supply stopping section that stops an electric power supply of a vehicle body when the restart standby time determining section determines that the restart standby time has elapsed.

Abstract: Provided is a construction machine that can prevent a machine body from being lowered since a blade is not put into a float state even where a misoperation is made by an operator when the machine body is in a jacked-up state, and that can perform a favorable leveling operation by putting the blade into the float state in accordance with an operator's operation when the machine body is not in the jacked-up state. A hydraulic excavator includes a controller 42 that determines whether or not the machine body is in a jacked-up state and controls a float valve 41. In the case where it is determined that the machine body is not in the jacked-up state, the controller 42 changes over the float valve 41 to a float position V and invalidates an operation of a blade control valve 22, in accordance with a float instruction.

Abstract: An electric construction machine is provided that can travel from a work location to a charging location, and can suppress deterioration of work efficiency. The electric hydraulic excavator includes: a battery device (19); an electric motor (28) that is driven by power of the battery device (19); a hydraulic pump (29) that is driven by the electric motor (28); a travelling hydraulic motor (7) and a work hydraulic actuator that are driven by a hydraulic fluid delivered from the hydraulic pump (29); a controller (37); and a display device (24).

Abstract: A cover mounting bracket (16) is provided on an upper side of a left weight part (11) and a right weight part (12) constituting a counterweight (10). The cover mounting bracket (16) is formed as a U-shaped frame with the counterweight (10) side open by a left extending member (17) extending forward from the upper side of the left weight part (11), a right extending member (18) extending forward from the upper side of the right weight part (12), and a connecting member (19) connecting the front side of the left extending member (17) and the front side of the right extending member (18). A prime mover cover (28) is supported on the connecting member (19) of the cover mounting bracket (16) rotatably in a vertical direction through a hinge (31). The prime mover cover (28) is moved between an open position where an inspection opening (15) of the counterweight (10) is opened and a closed position where the inspection opening (15) is closed around the hinge (31).

Abstract: A hydraulic drive system for a hydraulic excavator that enables leveling work and a jack-up operation by a blade in a float state, that can prevent a body from falling even when an operator has falsely operated the hydraulic excavator during the jack-up operation by the blade, and that yet can perform favorable leveling work with the blade turned into the float state is provided. A float switch 37, a float valve 38, and a controller 34 are provided, the float valve 38 is changed over to a float position VI upon operating the float switch 37 when the blade is not in a jack-up state, the float valve 38 is changed over from the float position VI to a normal position V when the float valve 38 is in a state of being at the float position VI and an operation lever device 22 has been operated, and the float valve 38 is kept at the normal position V when the float valve 38 is at the normal position V and the float switch 37 has been operated in the jack-up state.

Abstract: A filter (30) traps particulate matter in an exhaust gas. A filter inlet side pressure sensor (34) is provided in an inlet side of the filter (30). An EGR valve inlet side pressure sensor (22) is provided in an inlet side of an EGR valve (20). A regeneration controller (38C) determines whether or not the filter inlet side pressure sensor (34) is in failure based upon a difference between a pressure value detected by the filter inlet side pressure sensor (34) and a pressure value detected by the EGR valve inlet side pressure sensor (22). When the filter inlet side pressure sensor (34) is in failure, the regeneration controller (38C) performs control of regeneration treatment using a differential pressure calculated based upon a pressure value detected by the EGR valve inlet side pressure sensor (22) and a pressure value detected by the filter outlet side pressure sensor (35).

Abstract: Even where the differential pressure across a directional control valve associated with each actuator is very small, flow dividing control of the plurality of directional control valves can be performed stable, and even where a demanded flow rate suddenly changes at the time of transition from composite action to single action or the like, a sudden change of the flow rate of hydraulic fluid to be supplied to each actuator is prevented to implement superior combined operability. Further, the meter-in loss of the directional control valves can be reduced to implement a high energy efficiency.

Abstract: To provide a small hydraulic excavator, which even may have an upperstructure formed such that at least its rear end swings within a body width range and having a limited installation space for devices, that allows an accumulator to be disposed and allows the accumulator to be protected from external force generated during work. The present invention relates to a rear small-swing type mini excavator that includes an accumulator 30 accommodating and recovering potential energy and hydraulic energy used by at least one of drives of an undercarriage 1, an upperstructure 2 formed such that its rear end swings within the body width range of the undercarriage 1, and a working device 3.

Abstract: An electric construction machine that can travel from a work site to charging equipment and prevent the lowering of the work efficiency is provided. An electric hydraulic excavator includes a motor (28) that is driven by power of a battery device (19) and drives a hydraulic pump (29), a controller (37), and a display device (24). The controller (37) computes and stores the amount of consumed power of the motor (28) consumed during the period from the departure of the hydraulic excavator from the charging equipment to arrival at the work site, based on movement information of the hydraulic excavator acquired by a movement information acquiring device. The controller (37) subtracts the amount of consumed power from the amount of stored power of the battery device (19) to compute the amount of power consumable at the work site.

Abstract: When a swing motor and a boom cylinder are driven simultaneously, a hydraulic drive system appropriately adjusts a distribution of torques between hydraulic pumps and feeds back a torque actually consumed by the hydraulic pump for actuating the swing motor accurately to the hydraulic pump for actuating the boom cylinder. To that end, when boom raising and swinging are performed simultaneously, the hydraulic drive system corrects an allowable torque of a hydraulic pump 302 that supplies a hydraulic fluid to a swing motor 3c so as to be lowered by a certain ratio, reducing allowable torques of hydraulic pumps 102 and 202 that supply a hydraulic fluid to a boom cylinder 3a by torques consumed by the hydraulic pumps 102 and 202 that supply a hydraulic fluid to the swing motor 3c.

Abstract: Flow control over a hydraulic pump and flow dividing control of a plurality of directional control valves associated with actuators can stably be exercised even in a case in which differential pressures across the directional control valves are quite low, an abrupt change in a flow rate of the hydraulic fluid supplied to each actuator is prevented and excellent combined operability is realized even in an abrupt change in a demanded flow rate at a time of transition from a combined operation to a sole operation, and realizing excellent combined operability, and a meter-in loss in each directional control valve is reduced to realize high energy efficiency.

Abstract: Provided is a construction machine that can prevent a machine body from being lowered without placing a blade in a floating state when the machine body is jacked up, even if the operator performs an erroneous operation, and that can perform favorable leveling work by placing the blade in the floating state when the machine body is not jacked up. A hydraulic excavator includes a pressure sensor that detects the pressure in a bottom-side oil chamber of a blade cylinder, and a controller that switches between validation and invalidation of a floating command and a lowering command for a blade operation device. In the case where the pressure detected by the pressure sensor is less than a predetermined value, the controller switches a solenoid selector valve to an interruption position to invalidate the floating command when a forward stroke of the operation lever is equal to or more than a reference value.