Abstract: In a hydraulic shovel including a crawler-type lower traveling body and a storage box provided at the front side of the right side of an upper rotating body, the upper face of the crawler has a stable space that can be used as a scaffold for a worker or as a temporary storage space such as a supply tank. The storage box has, at the front side of the right side, a notch that is obliquely cut from the upper side of the inner end in the left-and-right direction of the crawler to the rear side of the left and right outer sides. The notch has, at the lower side thereof, the upper face of the crawler that provides a space S usable as a scaffold for a worker or as a temporary storage space.

Abstract: In a hydraulic shovel including a crawler-type lower travelingbody and a storage box provided at the front side of the right side of an upper rotating body, the upper face of the crawler has a stable space that can be used as a scaffold for a worker or as a temporary storage space such as a supply tank. The storage box has, at the front side of the right side, a notch that is obliquely cut from the upper side of the inner end in the left-and-right direction of the crawler to the rear side of the left and right outer sides. The notch has, at the lower side thereof, the upper face of the crawler that provides a space S usable as a scaffold for a worker or as a temporary storage space.

Abstract: A control device for suppressing engine load fluctuation according to main pump circuit conditions, wherein an assist torque calculation task includes a target engine torque calculation task separating smooth torque components from main pump load torque and setting a minimum value of either smooth torque component or engine setting torque as target engine torque, and a subtractor calculating target assist torque based on a difference between the main pump load torque and the target engine torque, the assist torque calculation task controlling a capacity of an assist pump based on the target assist torque and controlling switching between an assist mode and a charge mode.

Abstract: A control device for suppressing engine load fluctuation according to main pump circuit conditions, wherein an assist torque calculation task includes a target engine torque calculation task separating smooth torque components from main pump load torque and setting a minimum value of either smooth torque component or engine setting torque as target engine torque, and a subtractor calculating target assist torque based on a difference between the main pump load torque and the target engine torque, the assist torque calculation task controlling a capacity of an assist pump based on the target assist torque and controlling switching between an assist mode and a charge mode.

Abstract: An inexpensive engine assist device capable of performing stable energy regeneration from an accumulator and a working machine on which the engine assist device is mounted are provided. A variable capacity type main pump and a variable capacity type assist pump are directly connected to an engine. A return pressure oil flowing out from a fluid pressure actuator is temporarily accumulated by a sub-accumulator and is supplied to an inlet of the assist pump, and the assist pump pressurizes the return fluid pressure oil and supplies the return fluid pressure oil to a main accumulator. A controller calculates and controls an assist pump swash plate angle, and assist starting torque or charge starting torque, and introduces a pressure-accumulated fluid discharged from the main accumulator to the inlet of the assist pump or introduces a pressurized fluid discharged from an outlet of the assist pump into the main accumulator.

Abstract: Provided is a hydraulic circuit capable of efficiently recovering one and the other hydraulic energies for utilization by separating and recovering the same, one hydraulic energy being extruded from a hydraulic cylinder and the other hydraulic energy being extruded in starting and stopping rotation of a hydraulic motor, so as to allow an energy density of an accumulator to increase. The hydraulic circuit has: a first accumulator that accumulates pressure of hydraulic oil extruded from a boom cylinder; and a second accumulator that accumulates one pressure of the hydraulic oil relieved when the rotation of a swing motor is started and another pressure of the hydraulic oil extruded from a motor driving circuit with inertial rotation of the swing motor when rotation of the swing motor is stopped. A solenoid switch valve in passages that connect the first second accumulators closes the passages when pressure is accumulated in the second accumulator opens when the pressure in the second accumulator is discharged.

Abstract: The hydraulic circuit has: main pumps driven by an engine; a boom cylinder including a piston operating by hydraulic oil supplied from the main pumps, one chamber and the other chamber respectively partitioned and formed by the piston; an accumulator accumulating pressure of the hydraulic oil extruded from one chamber of the boom cylinder; and an assist pump motor suctioning the hydraulic oil from the accumulator when pressure continues to be accumulated in the accumulator and the accumulator pressure rises.

Abstract: Provided is a hydraulic circuit capable of saving a pump flow rate while hydraulic fluid is being accumulated in an accumulator. The hydraulic circuit has: a couple of boom cylinders that simultaneously operate the same operation by the hydraulic oil supplied under pressure from main pumps; an accumulator in which pressure of the hydraulic oil is accumulated; a pressure accumulating circuit that accumulates the pressure of the hydraulic oil extruded from one boom cylinder in the accumulator; and a regenerating circuit that regenerates the hydraulic oil extruded from the other boom cylinder to the boom cylinders.

Abstract: An inexpensive engine assist device capable of performing stable energy regeneration from an accumulator and a working machine on which the engine assist device is mounted are provided. A variable capacity type main pump and a variable capacity type assist pump having a motor function and a pump function are directly connected to an engine. A return pressure oil flowing out from a fluid pressure actuator is temporarily accumulated by a sub-accumulator and is supplied to an inlet of the assist pump, and the assist pump pressurizes the return fluid pressure oil and supplies the return fluid pressure oil to a main accumulator.

Abstract: A construction machine which is less vulnerable to theft compared with conventional machines is provided. The system includes an antenna (6) for detecting removal of an engine key (8) after the engine has stopped, an angle detector (35) for detecting a posture of the upper structure, and an anti-theft unit (31) for forcing the engine to stop and outputting an alarm signal in cases the upper structure is not in a given posture when parked.

Abstract: The present invention relates to remote radio control technology, and a remote radio control system includes a radio movable working machine (1), a remote control apparatus (6A), and a movable repeater station (7). First bidirectional communication means (31, 71) having a high radio wave directionality and first automatic tracking means (32, 71A) are provided between the working machine (1) and the repeater station (7), and second bidirectional communication means (63, 76) having a high radio wave directionality, second automatic tracking means (63A, 76A), and emergency spread spectrum bidirectional communication means (64, 87) for enabling bidirectional communication between the remote control apparatus (6A) and the repeater station (7) when communication by the second bidirectional communication means (63, 76) is impossible are provided between the remote control apparatus (6A) and the repeater station (7).

Abstract: A construction machine which is less vulnerable to theft compared with conventional machines is provided. The system includes an antenna (6) for detecting removal of an engine key (8) after the engine has stopped, an angle detector (35) for detecting a posture of the upper structure, and an anti-theft unit (31) for forcing the engine to stop and outputting an alarm signal in cases the upper structure is not in a given posture when parked.