A system for controlling stability in heavy machinery of the type including chains or treads, based on risk of rollover associated with the working position thereof, having multiple detectors measuring the reaction value at the support points of the machine on the ground, determination in each instant of a support base defined by the actual supports of the machine. A calculation algorithm for calculating the risk of rollover taking into consideration the moments of rollover associated with each side of the support base. Furthermore, the system includes calculating a reversible rollover condition where an index of the risk of rollover which is a proportionality function associated with the position of the center of gravity of the machine with respect to the limits of the reversible rollover area is defined.

A posture computing apparatus for a work machine includes a detection apparatus that is provided to the work machine and detects angular velocity and acceleration; a first posture angle computing unit that is provided to the detection apparatus and obtains a posture angle of the work machine from the angular velocity and the acceleration detected by the detection apparatus; a low-pass filter that allows the posture angle obtained by the first posture angle computing unit to pass therethrough to output the posture angle as a first posture angle; a second posture angle computing unit that outputs, as a second posture angle, a posture angle obtained from the angular velocity and the acceleration detected by the detection apparatus; and a selecting unit that outputs the first posture angle and the second posture angle in a switching manner, based on information about a change in an angle of the work machine.

A drive control system of a hydraulic excavator includes a control device. When accelerating a turning body to a target turning speed, the drive control device controls an operation of the electric motor driving device such that the electric motor outputs high efficiency torque by which a highest electric power efficiency is obtained at the target turning speed. The control device controls an operation of an oil pressure supply device such that residual torque obtained by subtracting the high efficiency torque from target torque is output from an oil-pressure motor.

A hybrid-type construction machine includes: a motor generator system connected to an internal combustion engine and performing a motor generator operation; an electric power accumulation system connected to the motor generator system; a load drive system connected to the electric power accumulation system and being driven electrically; an abnormality detection part equipped to the motor generator system, the electric power accumulation system and the load drive system; and a main control part determining whether an abnormality has occurred based on a detection value of the abnormality detection part. When the abnormality determination part determines that an abnormality has occurred, the main control part stops a drive of a drive system in which the abnormality is detected in the load drive system.

An exemplary embodiment suggested in the present specification provides an apparatus and a method of controlling a voltage of a direct current terminal of construction machinery equipped with a motor, which are capable of improving energy efficiency of a power conversion apparatus, such as an inverter and a converter by changing a voltage of the direct current terminal to an optimum voltage size in consideration of operation conditions of a swing motor, an engine auxiliary motor, and an energy storage apparatus.

Disclosed is a hydraulic construction machinery capable of operating a travel apparatus and a swing apparatus, when same are to be operated in combination, by means of working fluids supplied at the maximum discharge flow rate from a plurality of hydraulic pumps. A hydraulic construction machinery according to the present invention comprises: first and second hydraulic pumps; travel and swing motors connected to the first hydraulic pump; a hydraulic actuator connected to the second hydraulic pump; a main control valve comprising a first control valve and a second control valve, the first control valve controlling a working fluid supplied from the first hydraulic pump to the travel and swing motors, and the second control valve controlling the working fluid supplied from the second hydraulic pump to the hydraulic actuator; a first regulating valve, disposed on the most upstream side of a supply channel of the second hydraulic pump, for switching when the travel and swing motors are operated simultaneously so that the working fluid of the first hydraulic pump is supplied to the travel motor and the working fluid of the second hydraulic pump is supplied to the swing motor; a second regulating valve, disposed on the most downstream side of a supply channel of the second hydraulic pump, for switching when the travel and swing motors are operated simultaneously so as to close the most downstream opening of the supply channel of the second hydraulic pump; and an electronic proportional valve for outputting a control signal, corresponding to a control signal from a controller, to the first and second regulating valves when a manipulation signal, sensing whether the travel and swing motors are manipulated, is entered in the controller.

Provided is a hybrid-type construction machine including a swing device of the hydraulic-electric combined swing type and by which, in a work for which accurate swing operability is demanded like, for example, a crane work, a swing body is driven alone by the electric motor. The hybrid-type construction machine includes an engine, a hydraulic pump driven by the engine, a swing body, an electric motor for driving the swing body, and a hydraulic motor driven by the hydraulic pump for driving the swing body. The swing body is swung by simultaneous drive by the electric motor and the hydraulic motor. The hybrid-type construction machine includes a control apparatus having a work mode changeover unit by which an operator changes over a mode in response to an aspect of a work and an electric alone swing controlling unit configured to control the swing body to be swung by the electric motor alone. When a work in which position accuracy is demanded is selected by the work mode changeover unit, the swing body is swung by the electric alone swing controlling unit.

To control a rate of increase of a delivery flow rate of a pump for a swing operation in response to a moment of inertia and an operation amount and to achieve both energy efficiency and operability with respect to the swing operation, a work machine including a swing structure 2 disposed on an upper portion of a track structure 1, a work implement 3 disposed in the swing structure 2, a swing motor 16, a hydraulic pump 22, a regulator 24, a directional control valve 31, and an operation device 34 further includes: a target maximum flow rate calculation section 53 configured to calculate a target maximum flow rate Qmax of the pump to correspond to a swing operation amount Ps; a flow rate rate-of-increase calculation section 55 configured to calculate a rate of increase dQ of a command flow rate of the hydraulic pump 22 on a basis of the moments of inertia of the swing structure 2 and the work implement 3 and the swing operation amount Ps; a command flow rate calculation section 56 configured to calculate a command flow rate Q(t) on a basis of the rate of increase dQ with the target maximum flow rate Qmax set as an upper limit; and an output section 57 configured to output a command signal Sf to the regulator 24 corresponding to the command flow rate Q(t).

A hydraulic excavator includes a plurality of cameras that are attached to an upper swing structure and photograph images of surroundings, a controller configured to detect an obstacle present around the upper swing structure on the basis of the camera images, and a speaker that makes a notification that the obstacle is detected when the controller detects the obstacle. When a lock lever is at a lock release position and control levers are maintained in a non-operating state from a time of a start of the controller, the controller permits the notification by the speaker. When the lock lever is at the lock release position and the control levers are changed from an operating state to a non-operating state, the controller permits the notification by the speaker when the non-operating state is continued for a predetermined time or more.

A swivel working machine includes a machine body swivelable around a swivel axis, a working device attached to the machine body swingably around a swing axis, an operation member to be handled and operated by an operator, and a controller to control swivel movement, which is a swiveling movement of the machine body, and swing movement, which is a swinging movement of the working device. The controller includes an operation pattern shifting unit configured or programmed to perform shifting between a swivel operation state where operation of the operation member in a specific direction causes the swivel movement and a swing operation state where the operation of the operation member in the specific direction causes the swing movement.