Abstract: There is provided a work machine that is capable of realizing operability and energy saving ability that are equivalent to those of work machines that have a joint line to be used during swinging/boom raising operation, without incorporating a joint line for supplying a pressurized fluid from a second pump to a bottom-side chamber of a boom cylinder. The controller is configured to compute a hypothetical flow rate representing a flow rate in a hypothetical joint line, compute a first pump provisional target flow rate on the basis of an operation amount of a boom operation device, compute a second pump provisional target flow rate on the basis of an operation amount of a swing operation device, compute a first pump final target flow rate by adding the hypothetical flow rate to the first pump provisional target flow rate, and compute a second pump final target flow rate by subtracting the hypothetical flow rate from the second pump provisional target flow rate.

Abstract: To provide a work machine that enables enhancement of shaping accuracy near a boundary line between two adjacent target surfaces. A controller 10 extracts, from among a plurality of target surfaces, a second target surface S2 that is a target surface adjacent to a first target surface S1, calculates a boundary line L2 between the first target surface S1 and the second target surface S2, and, prior to a work tool 6 passing the first boundary line L2, corrects a control signal for a posture control actuator 6c such that the angular difference EL between a reference line L1 set on the work tool 6 and the boundary line L2 becomes small.

Abstract: 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 com

Abstract: A construction machine that precisely enables derivation of the operation characteristics of hydraulic actuators in a high-velocity area with less calibration operation is provided. A controller (10) has a calibration mode in which the controller (10) derives operation characteristics (?(xs)) representing a relation among a spool position (xs) of a meter-in valve (8a1), an operation velocity (Va) of a hydraulic actuator (4a), and a differential pressure (?P) across the meter-in valve (8a1), and is configured to, in a case where the spool position (xs) of the meter-in valve (8a1) has changed in a direction to increase the opening area of the meter-in valve (8a1) in the calibration mode, output a command signal to increase the opening area of a bleed-off valve (8b1) to a bleed-off solenoid proportional pressure-reducing valve (8b2) as a command signal to reduce the differential pressure (?P).

Abstract: To provide a construction machine that can improve the energy efficiency in a leveling operation in which an arm crowding operation and a boom raising operation are performed simultaneously.

Abstract: A construction machine includes a posture sensor provided on a front member of a front work implement. An external environment recognition device detects an object around a main body, and a controller calculates a dead angle range from a recognition range of the external environment recognition device. An assumed movement range in which a moving body is assumed to exist in the dead angle range in a period of time determined in advance is calculated; and a movable range within which the front work implement is movable in a period of time determined in advance is calculated on the basis of the posture information detected by the posture sensor. Preventative control is then performed for preventing contact between the moving body and the front work implement on the basis of the assumed movement range of the moving body and the movable range of the front work implement.

Abstract: An object of the present invention is to provide a construction machine that allows easy and accurate calibration of a pressure sensor and enables accurate control of hydraulic actuators.

Abstract: To provide a construction machine that can highly precisely control branch flows from a hydraulic pump to a plurality of hydraulic actuators without being affected by load conditions. A controller (100) has a meter-out valve control section (140) configured to calculate a target opening area of a second meter-out valve (65a) (65b) according to a pressure difference between a supply pressure and a second meter-in pressure, or calculate a target opening area of a first meter-out valve (55a) (55b) according to a pressure difference between the supply pressure and the first meter-in pressure.

Abstract: There is provided a work machine that is capable of realizing operability and energy saving ability that are equivalent to those of work machines that have a joint line to be used during swinging/boom raising operation, without incorporating a joint line for supplying a pressurized fluid from a second pump to a bottom-side chamber of a boom cylinder. The controller is configured to compute a hypothetical flow rate representing a flow rate in a hypothetical joint line, compute a first pump provisional target flow rate on the basis of an operation amount of a boom operation device, compute a second pump provisional target flow rate on the basis of an operation amount of a swing operation device, compute a first pump final target flow rate by adding the hypothetical flow rate to the first pump provisional target flow rate, and compute a second pump final target flow rate by subtracting the hypothetical flow rate from the second pump provisional target flow rate.

Abstract: Provided is a construction machine capable of driving each hydraulic actuator at a suitable speed while suppressing delivery flow rate of a hydraulic pump, both at a single operation time of driving each hydraulic actuator respectively singularly and at a combined operation time of simultaneously driving a plurality of hydraulic actuators.

Abstract: A construction machine is provided that can cause each hydraulic actuator to accurately operate according to operation by an operator in combined operation in which a hydraulic fluid of a hydraulic pump is subjected to flow dividing and is supplied to plural hydraulic actuators. A controller 10, in a case of determining that combined operation is being carried out, controls a regulator 7a in such a manner that the delivery flow rate of a hydraulic pump 7 becomes larger than the total target flow rate of plural hydraulic actuators 4a, 5a, and 6a, and controls the respective opening amounts of plural directional control valves 8a1, 8a3, and 8a5 in such a manner that the difference between the respective target flow rates of the plural hydraulic actuators and the respective inflow flow rates of the plural hydraulic actuators sensed by velocity sensors 12 to 14 becomes small.

Abstract: To provide a construction machine that can improve the energy efficiency in a leveling operation in which an arm crowding operation and a boom raising operation are performed simultaneously.

Abstract: A main controller and a hybrid controller control an engine, an assist generator motor, a hydraulic pump and an electricity storage device. In this case, the hybrid controller is provided with a performance state recovery part that performs performance state recovery of the electricity storage device. In a case where a performance state amount varying with repetition of a discharge and a charge of the electricity storage device, specifically, a current integrated value ratio of the electricity storage device goes beyond a predetermined threshold value (L1%), the performance state recovery part limits power of the hydraulic pump. Thereby, the performance state recovery part performs the performance state recovery of the electricity storage device.

Abstract: A work machine capable of driving each actuator more speedily and more accurately by ensuring high operability in a case of operator's manual operation, while accurately supplying a hydraulic fluid at a target flow rate to the actuator without depending on a load fluctuation in a case of automatic control over a machine body in response to a command input from a controller is provided. The controller controls a plurality of auxiliary flow controllers in such a manner that supply flow rates to a plurality of directional control valves from hydraulic pumps either fluctuate in response to load fluctuations of a plurality of hydraulic actuators when an area limiting control function invalidation instruction is issued, or do not fluctuate in response to the load fluctuations of the plurality of hydraulic actuators when an area limiting control function validation instruction is issued.

Abstract: A construction machine that precisely enables derivation of the operation characteristics of hydraulic actuators in a high-velocity area with less calibration operation is provided. A controller (10) has a calibration mode in which the controller (10) derives operation characteristics (?(xs)) representing a relation among a spool position (xs) of a meter-in valve (8a1), an operation velocity (Va) of a hydraulic actuator (4a), and a differential pressure (?P) across the meter-in valve (8a1), and is configured to, in a case where the spool position (xs) of the meter-in valve (8a1) has changed in a direction to increase the opening area of the meter-in valve (8a1) in the calibration mode, output a command signal to increase the opening area of a bleed-off valve (8b1) to a bleed-off solenoid proportional pressure-reducing valve (8b2) as a command signal to reduce the differential pressure (?P).

Abstract: To provide a construction machine that can highly precisely control branch flows from a hydraulic pump to a plurality of hydraulic actuators without being affected by load conditions. A controller (100) has a meter-out valve control section (140) configured to calculate a target opening area of a second meter-out valve (65a) (65b) according to a pressure difference between a supply pressure and a second meter-in pressure, or calculate a target opening area of a first meter-out valve (55a) (55b) according to a pressure difference between the supply pressure and the first meter-in pressure.

Abstract: A work machine capable of driving each actuator more speedily and more accurately by ensuring high operability in a case of operator's manual operation, while accurately supplying a hydraulic fluid at a target flow rate to the actuator without depending on a load fluctuation in a case of automatic control over a machine body in response to a command input from a controller is provided.

Abstract: A main controller and a hybrid controller control an engine, an assist generator motor, a hydraulic pump and an electricity storage device. In this case, the hybrid controller is provided with a performance state recovery part that performs performance state recovery of the electricity storage device. In a case where a performance state amount varying with repetition of a discharge and a charge of the electricity storage device, specifically, a current integrated value ratio of the electricity storage device goes beyond a predetermined threshold value (L1%), the performance state recovery part limits power of the hydraulic pump. Thereby, the performance state recovery part performs the performance state recovery of the electricity storage device.

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 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 com