Abstract: An articulated-type front work implement has a boom, an arm, and a bucket that are driven members coupled to each other; a boom cylinder, an arm cylinder and a bucket cylinder that are hydraulic actuators each of which drives a corresponding one of the plurality of driven members on the basis of an operation signal; a plurality of operation members each outputting the operation signal to one of the hydraulic actuators; and a controller that outputs the operation signal to at least one of the plurality of hydraulic actuators or executes area limiting control of correcting the output operation signal such that the front work implement moves on a target surface preset for a work target of the front work implement or within an area above the target surface, and corrects the operation signal on the basis of information related to operation of the hydraulic actuator.

Abstract: Provided is a construction machine in which travel operability is not impaired when a combined operation is performed in which a single-rod hydraulic cylinder is driven during a travel operation. A hydraulic excavator includes a controller that controls the delivery direction and delivery flow rate of a closed-circuit pump, opens and closes a travel switching valve and an assist switching valve, and controls the delivery flow rate of the open-circuit pump, according to a travel operation lever and a work operation lever. The controller holds the assist switching valve in a closed position irrespective of whether or not the work operation lever is operated in a case where the travel operation lever is operated.

Abstract: The invention of the present application intends to provide a work machine that can ensure high operability by preventing abrupt actuation of an actuator and a shock to a machine body by use of a bleed-off function at the time of starting of the actuator and that can improve the energy-saving performance by reducing a bleed-off flow rate after the starting of the actuator. For this purpose, a controller opens a bleed-off valve at a timing at which an operation device is being operated and before a flow rate of a hydraulic pump starts increasing, and closes the bleed-off valve at a timing at which the operation device is being operated and after the flow rate of the hydraulic pump has started increasing.

Abstract: When a tilt in a right-and-left direction occurs in a cargo bed (9) being raised due to imbalance of excavated materials, the tilt is detected as a roll angle (?R), and it is determined whether the absolute value (|?R|) of the roll angle is not less than an imbalance determination value (?2) (S4). When the absolute value is not less than the imbalance determination value (?2) (Yes in S4) and the roll angle (?R) is positive (the cargo bed (9) is rising to the right) (Yes in S8), an oil supply amount (VL) to a hoist cylinder (11) on the left side is increased, and an oil supply amount (VR) to a hoist cylinder (12) on the right side is decreased (S9). When the roll angle (?R) is negative (the cargo bed (9) is rising to the left) (No in S8), the oil supply amount (VL) on the left side is decreased, and the oil supply amount (VR) on the right side is increased (S10).

Abstract: A work vehicle including a drive device (10) having an internal combustion engine (12) for driving a vehicle body (1) has: a first tank (32) that is disposed in front of or behind the drive device, and stores fuel (9) to be supplied to the internal combustion engine; a second tank (34) that is disposed below the drive device so as to be separated from the first tank by a predetermined distance, and stores the fuel to be supplied to the internal combustion engine; a first storage amount detection part (70) that is disposed in the first tank, and detects an amount of the fuel stored in the first tank; and a second storage amount detection part (80) that is disposed in the second tank, and detects an amount of the fuel stored in the second tank.

Abstract: In a case of a normal operation, a battery controller (22) assumes a normal operation mode and permits charging and discharging of a battery module (21). Upon receiving a discharge command from a vehicle body controller (17) for completely discharging the battery module (21), the battery controller (22) assumes a discharge mode to discharge the battery module (21) to reach a safe voltage level and store discharge information. Upon reading out the discharge information, the battery controller (22) assumes a discharge prohibition mode to prohibit charging and discharging of the battery module (21).

Abstract: The present invention provides a working machine that makes it possible to alert its operator to cautions properly without obstructing the view of the operator. The working machine includes a cab for its operator to ride in, a projection device that projects image light to form an image of cautions to an operator who operates the working machine, a display unit that displays image light projected by the projection device, state detection element to detect a state of the working machine, and a controller that controls the projection device so that a manner of displaying the cautions on the display unit will change depending on the state of the working machine detected by the state detection element.

Abstract: The object of the present invention resides in provision of a construction machine in which a hydraulic cylinder can be driven in a high efficiency by an accumulator. To this end, the construction machine including: a hydraulic cylinder; a first accumulator that accumulates return fluid from the hydraulic cylinder with a first set pressure; a tank that stores hydraulic fluid therein; a first hydraulic pump that delivers the hydraulic fluid sucked from the tank; a hydraulic actuator that is driven by the first hydraulic pump; and a second accumulator that accumulates return fluid from the hydraulic actuator with a second set pressure, includes a first control valve placed in a first hydraulic line that connects the first accumulator and the hydraulic cylinder to each other, and a second control valve placed in a second hydraulic line that connects the second accumulator and the hydraulic cylinder to each other. The second set pressure is set to a value higher than that of the first set pressure.

Abstract: Provided is a work machine capable of achieving both low fuel consumption and ensuring of workability. The work machine is configured to, in a state where an output of an engine or hydraulic pump has increased to an increase threshold (S12: Yes) with the rotational speed being at a first rotational speed (S11: Yes), raise the rotational speed from the first rotational speed to a second rotational speed (S13); in a process of raising the rotational speed to the second rotational speed, output, to a regulator, a signal instructing reduction in the discharge rate (S14) so as to keep the output of the engine or hydraulic pump constant; and after the rotational speed has reached the second rotational speed, output, to the regulator, a signal instructing increase in the discharge rate (S16) so as to make the output of the engine or hydraulic pump have a value corresponding to a request load.

Abstract: A work machine includes: a hydraulic actuator that is driven by a hydraulic fluid from a hydraulic pump; an open-center directional control valve that is arranged on a center bypass line, and controls a flow of the hydraulic fluid to be supplied to the hydraulic actuator; a CB cut valve arranged between a directional control valve and a hydraulic working fluid tank on the center bypass line; and a machine controller that controls an opening of the CB cut valve. The machine controller restricts the opening of the CB cut valve when operation on the hydraulic actuator is in a fine operation state in which the operation on the hydraulic actuator is within a predetermined range representing a region of fine operation, and the fine operation state is continued longer than a predetermined period, and fully opens the CB cut valve otherwise.

Abstract: Each time clogging of a filter (5) of an air cleaner is determined on the basis of intake negative pressure of an engine (2), and the air filter (5) is cleaned, an accumulated value of operating time of the engine (2) from previous cleaning until clogging is determined is taken as a cleaning interval (S), and sequentially measured. A plurality of stages are previously set by classifying a minimum value and a maximum value of the cleaning interval (S), and the measured cleaning interval (S) is added to the stage to which the measured cleaning interval (S) is to belong, among the stages. A histogram in which an axis of abscissas is taken as the stage, an axis of ordinates is taken as frequency of the cleaning interval (S) is constructed, and an approximate straight line (L2) illustrated by a solid line is obtained by approximating a characteristic line (L1) of the histogram illustrated by a dotted line to a straight line.

Abstract: A plus-side main connection line (27) connects electrical equipment (21), (22) to a plus terminal (26A) of a battery (26). A plus-side isolating switch (28) is provided in the plus-side main connection line (27) to connect or disconnect the electrical equipment (21), (22) and or from the plus terminal (26A) of the battery (26). A plus-side auxiliary connection line (30) connects a urea SCR controller (25) to the plus terminal (26A) of the battery (26) in a position upstream of the plus-side isolating switch (28). A minus-side main connection line (32) connects a minus terminal (26B) of the battery (26) to ground. A minus-side isolating switch (33) is provided in the minus-side main connection line (32) to connect or disconnect the minus terminal (26B) of the battery (26) and or from ground.

Abstract: A wheel loader includes a lift arm, bucket, a lift cylinder that rotates the lift arm, a hydraulic force detection unit that detects a hydraulic force of the lift cylinder, an arm angle detection unit that detects a rotation angle of the lift arm, and a controller that calculates a weight of the load. A hydraulic force measurement unit measures a hydraulic force with the rotation angle of the lift arm within a predetermined measurement angle range; and a hydraulic-force-change-rate calculation unit calculates a change rate of the hydraulic force with respect to the rotation angle of the lift arm, and then calculates a new hydraulic force change rate within the measurement angle range. The controller corrects an error of the weight of the load occurring due to the inclination angle of the body on the basis of the new hydraulic force change rate calculated by the hydraulic-force-change-rate calculation unit.

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: Provided is a wheel loader capable of reducing erroneous determination of rear wheel lifting. The wheel loader 1 includes a controller 5 for determining a rear wheel lifting state where rear wheels 11B are lifted upwardly. The controller 5 is configured to, when a temporal change rate ? of a bucket operation angle becomes a temporal change rate of a bucket operation angle necessary for a tilt operation of a bucket 23 during an excavation operation and a temporal change rate ? of a vehicle body inclination angle estimated by the controller 5 becomes a temporal change rate of an obliquely upward inclination state of a rear vehicle body with respect to a front vehicle body, turn on a correlation flag indicating a correlation between an operation state of the bucket 23 and an inclination state of a vehicle body to determine a rear wheel lifting.

Abstract: A controller mounted in a hydraulic excavator includes: a state transition section that performs switchover between two types of control that are manual control and semiautomatic control, on the basis of input of a state switching signal; and a velocity transition section that changes a rate of change with time in a velocity of a boom cylinder from a first rate of change I1 to a second rate of change I2 greater than the first rate of change I1 in a case in which input to an operation lever changes since the state transition section switches over between the two types of control until the velocity of the boom cylinder changes to a velocity Vo(t) specified by the control after the switchover between the two types of control.

Abstract: Provided is a wheel loader capable of automatically decreasing vehicle speed without making an operator feel discomfort during a loading operation. A wheel loader 1 mounted with a torque converter type traveling drive system comprises a controller 5 configured to control shifting of a transmission 32. When a vehicle body travels forward at vehicle speed corresponding to a second speed stage set greater by one speed stage than the lowest speed stage of the transmission 32 while operating the lift arm 21 upwardly, the controller 5 sets, as a gear ratio of the transmission 32, an intermediate gear ratio between a gear ratio corresponding to the second speed stage and a gear ratio corresponding to a first speed stage, and outputs a signal for selecting a combination of a plurality of gears corresponding to the set gear ratio to each first to fifth solenoid control valves 32A to 32E.

Abstract: A coordinate conversion system including a controller that converts geographic-coordinate-system coordinates of a certain point into site-coordinate-system coordinates includes: an image-capturing device that captures an image of a reference point; and a GNSS antenna that receives a navigation signal.

Abstract: A loading vehicle is capable of improving work efficiency by adjusting engine rotational speed with high accuracy in accordance with an operation state of the working device. An HST traveling driven wheel loader has an electrically controlled HST pump. A controller is configured to control input torque of the HST pump 31 and solenoid proportional pressure reducing valve is configured to generate control pressure for controlling displacement volume of the pump based on a control signal from the controller. The controller is configured to calculate the displacement volume q of the HST pump based on discharge pressure Pf of a loading hydraulic pump so that maximum input torque Thst of the HST pump decreases as the discharge pressure Pf or input torque of the loading hydraulic pump increases, and output a control signal corresponding to the calculated displacement volume q to the solenoid proportional pressure reducing valve.

Abstract: The hydraulic excavator 1 includes a work implement 7, a detection device that detects an obstacle around the hydraulic excavator 1, and a controller 27 that controls the operation of the work implement 7. The controller 27 has a driving assistance function and a work assistance function. The work assistance function is switchable between enabled and disabled. When the work assistance function is switched to enabled, the controller 27 suppresses, for an obstacle detected in a monitoring range but outside of a work range, the driving assistance function in comparison with when the work assistance function is switched to disabled.