Abstract: 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).

Abstract: A load value W, which is a weight of a transportation target carried by a front work implement 12, is calculated based on a work load of a boom cylinder 16 of the front work implement 12, and on posture information which is information associated with a posture of the front work implement 12. A load threshold T used for determining whether to recalibrate a load measuring system is changed in accordance with a posture index value which is an index associated with the posture of the front work implement 12 and is obtained based on the posture information. Whether to recalibrate the load measuring system is determined based on the load value W and the load threshold T. A determination result is displayed on a display screen 30 to notify an operator of the determination result. In this manner, deterioration of measuring accuracy is more appropriately detectable regardless of variations of a posture of a front work implement of a work machine.

Abstract: It is an object of the present invention to provide a construction machine having a good engine starting property in a low temperature environment. The construction machine of the present invention includes: an electric pump having a delivery port connected to a line part of a pilot line, the line part connecting a pilot pump with a pilot control valve; a motor that drives the electric pump; and a temperature sensor that measures a temperature of a hydraulic working fluid delivered from the pilot pump. A controller starts driving of the motor in the case where a key switch is operated from a key OFF state to a key ON state and where the temperature of the hydraulic working fluid measured by the temperature sensor is lower than a predetermined temperature.

Abstract: A hydraulic drive system includes a swing directional control valve 81 and a third boom directional control valve 82 that are connected to a third hydraulic pump 33. Furthermore, the hydraulic drive system includes: a second auxiliary directional control valve 84 that is connected to the third hydraulic pump 33, and is connectable with a second special hydraulic actuator 64 for driving special attachments; and a first selector valve 96 that is connected to the third hydraulic pump 33 upstream of the second auxiliary directional control valve 84, and is connectable with an additional hydraulic pump 97. The first selector valve 96 switches the hydraulic fluid source of the second special hydraulic actuator 64 connected to the second auxiliary directional control valve 84 at least between the third hydraulic pump 33 and the additional hydraulic pump 97.

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: The safe operation assistance device 200 includes: a connecting destination detecting section 259 that detects and manages a connection state between the safe operation assistance device 200 and a connecting destination device; a unique information setting section 251 that sets unique information identifying a vehicle type of an own vehicle according to the connecting destination device; a positional information acquisition section 257 that acquires positional information of the own vehicle; an own vehicle information management section 252 that manages the positional information and the unique information of the own vehicle; an inter-vehicle communication section 255 that transmits the own vehicle information to other vehicle and acquires other vehicle information; and a risk determination section 254 that determines presence or absence of a collision risk between the own vehicle and the other vehicle using the own vehicle information and the other vehicle information.

Abstract: A relay (25) connects and disconnects an electrical circuit to which an inverter (16) and an electricity storage device (19) are connected. A BCU (22) controls the electricity storage device (19). An HC (27) controls an electric motor (15), the inverter (16) and the BCU (22). The HC (27) and the BCU (22) respectively have FET switches (30, 31) for controlling supply and stop of the excitation current in the relay (25). When the electricity storage device (19) is determined to be in an abnormal state, the BCU (22) transmits an abnormal signal to the HC (27), and when a predetermined time has elapsed, turns off (opens) the first FET switch (30) of the BCU (22). The HC (27) executes stop processing based upon the abnormal signal received from the BCU (22) and then turns off (opens) the second FET switch (31) of the HC (27).

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 pedal operation switching mechanism can switch a foot pedal to any movement pattern of three movement patterns of a front/rear step pattern of being capable of the operation of depressing a front side of the foot pedal from a neutral position of a rotational part of a pilot valve and of being capable of the operation of depressing a rear side of the foot pedal from the neutral position of the rotational part, a front step limit pattern of being capable of the operation of depressing only the front side of the foot pedal from the neutral position of the rotational part, and a fixing pattern of fixing the movement of the foot pedal in the neutral position of the rotational part.

Abstract: A work vehicle is provided. The work vehicle is capable of notifying an operator of a state close to overheating of a temperature of a cooling oil that cools a brake device before the temperature overheats. A controller (10) in a work vehicle (100) compares each detection value detected from a brake pressure sensor (26) and a vehicle speed sensor (15) to each threshold (V1, P1, R1) predetermined corresponding to each sensor. The controller (10) outputs a warning command that a temperature of a cooling oil is likely to overheat to a notification device (28) when a state that at least one detection value is equal to or more than the threshold and when a state that at least one detection value is equal to or more than the threshold continues for a first duration (t1) or more.

Abstract: To provide a power regeneration system for a working vehicle that can effectively use a regenerative electric energy. A first electric circuit for supplying an electric power generated by the first generator to a traveling motor, a voltage detector for detecting an actual voltage of the first electric circuit, a second electric circuit for supplying an electric power generated by a second generator to an auxiliary device, a step-down device connected to the first electric circuit and the second electric circuit, and a controller are provided. The controller estimates the voltage of the first electric circuit after a predetermined time has elapsed from the present time, based on information on a traveling state of a work vehicle and the actual voltage detected by the voltage detector, and outputs a drive command to the step-down device when the estimated voltage is equal to or more than a threshold.

Abstract: A controller (18) calculates, based on a target loading weight (P) that is a target value of a total weight of working objects to be loaded into a hauling vehicle, a set loading time number indicative of a loading time number required for the construction machine before the target loading weight (P) is reached and bucket shape information indicative of a shape of a bucket (7), an appropriate loading weight (Wa) that is an appropriate value of the weight of the working objects to be loaded into the hauling vehicle by a single time loading work by the construction machine, creates an appropriate amount illustration (30) that is an illustration of a state at which the working objects of the appropriate loading weight (Wa) are loaded into the bucket and that illustrates the state of the working objects, based on the appropriate loading weight (Wa) and the bucket shape information, and controls a display device (19) to display an illustration (29) of the bucket (7) and the appropriate amount illustration (30) in a

Abstract: Provided is a hydraulic excavator (1) that performs work by operating an arm (9) after moving a bucket (10) to a work start position. An operation determination section (81c) determines, based on an operation performed on an operation device, whether a front work device (1A) is engaged in a work preparation operation for moving the bucket to the work start position. When the operation determination section determines that the front work device is engaged in the work preparation operation at the time of operation of the operation device, an actuator control section (81) controls a bucket cylinder (7) such that the angle of a work tool with respect to a target surface coincides with a preset target angle (?TGT).

Abstract: Provided is a wheel loader in which the speed position of the transmission can be easily changed with a small number of switches. The wheel loader 1 includes a tilting angle sensor 9 for detecting the tilting angle of the vehicle body. In case that the vehicle body is traveling on an uphill or a downhill with a transmission 33 in a higher speed position than the lowest speed position, and the tilting angle detected by the tilting angle sensor 9 is not smaller than a prescribed threshold value, a transmission control device 45 sends the transmission 33 a command to downshift the transmission 33 one speed position by each operation of a shiftdown switch 62.

Abstract: It is determined whether a velocity estimation model is established from an actual operating velocity Vr and a target operating velocity Vt of each of actuators 20A, 21A, and 22A; in a case in which the velocity estimation model is established, a dynamic center-of-gravity position of a hydraulic excavator 1 in a case in which each of the actuators 20A, 21A, and 22A is suddenly stopped from a driven state is predicted from an estimated operating velocity Ve; in a case in which the velocity estimation model is not established, the dynamic center-of-gravity position is predicted from the actual operating velocity Vr and it is determined whether to execute control intervention using the predicted dynamic center-of-gravity position; and in a case in which it is determined to execute the control intervention, the target operating velocity Vt is corrected in such a manner that each of the actuators 20A, 21A, and 22A slowly decelerate.

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 controller (40) of a hydraulic excavator (1) includes: a first distance calculation section (43f) calculating a first distance D1 that is a distance between a bucket toe and a target surface on a virtual straight line Lv extended vertically from the bucket toe, based on position information on the bucket toe and position information on the target surface (700); and a second distance calculation section (43g) calculating a second distance D2 that is a distance between the target surface and a current landform on the virtual straight line Lv, based on the position information on the bucket toe and the position information on the target surface and position information on the current landform 800. A display device (53a) displays the first distance D1 and the second distance D2.

Abstract: A hydraulic excavator includes: a multijoint type front implement that is configured by coupling a plurality of driven members including a bucket; inertial measurement units that detect posture information about the plurality of driven members; and a calibration value computing section that computes calibration parameters used in calibration of detection results of the inertial measurement units; and a work position computing section that computes a relative position of the bucket to the machine body on the basis of the detection results of the inertial measurement units and the computation result of the calibration value computing section, and the calibration value computing section computes the calibration parameters on the basis of the detection results of the inertial measurement units in a plurality of postures of the front implement in which a reference point set on any of the plurality of driven members in advance matches a reference position.

Abstract: A controller (45) is provided with an elapse time measuring section (47A) that measures an elapse time (tx) elapsed since an initial use of an accumulator (29) based upon a reset signal from a reset switch (44), a number-of-operations measuring section (47B) that measures a number of operations of the accumulator (29), that is, a number (N) of boom lowering operations after a reset, based upon a detection signal from an accumulator side pressure sensor (39), a gas permeation amount estimating section (47C) that estimates an estimation gas permeation amount (Qloss) of the accumulator (29), a sealed gas pressure estimating section (47D) that finds an estimation sealed gas pressure (Pgs) of a gas chamber (29B) of the accumulator (29), and an accumulator degradation determining section (47E) that determines a degradation condition of the accumulator (29) and outputs the determination result.