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: A machine controller that controls an action of the construction machine; an external operation controller that controls unmanned operation that does not require operation by an operator riding in an operation room, by generating a control signal according to an operation signal received from an outside via a communication terminal, and sending the control signal to the machine controller; an approach permission signaling light that signals permission for a worker to approach the construction machine; and an action request signaling light that signals a request for riding in the operation room and performing a particular action to a nearby worker are provided, and the external operation controller is configured to control the approach permission signaling light to be turned on when it is decided that approach of the worker to the construction machine can be tolerated according to information collected by the machine controller, and also control the action request signaling light to be turned on when it is dec

Abstract: Provided are a machine controller that controls operation of the hydraulic excavator, an external operation controller that executes control of unattended operation that does not require operation through riding of an operator in a cab, by generating a control signal according to an operation signal received from the external through a communication terminal and sending out the control signal to the machine controller, an operation indicator light that indicates that the unattended operation of the hydraulic excavator is normally in operation, and an approach permission indicator light that indicates permission of approach of a worker to the hydraulic excavator. The external operation controller, according to information collected into the machine controller, turns on the operation indicator light when determining that the hydraulic excavator is normally operating, and turns on the approach permission indicator light when determining that approach of the worker to the hydraulic excavator is permissible.

Abstract: In a hydraulic excavator including a machine body and a front work device, when an object is detected by sensors for detecting an object around the machine body when operation limiting control for limiting the operation of at least one of the machine body and the front work device is enabled, or when an operation device is operated, the detection of the object is notified to an operator by a first state warning, and when the operation limiting control is enabled and when the operation device is not operated, the detection of the object is notified to the operator by a second state warning that is weaker in warning intensity than the first state warning. Accordingly, the botheration for the operator can be suppressed while securing the effectiveness of an alarm in periphery monitoring, and the safety performance can be enhanced.

Abstract: A work machine includes a swing structure, a work device, a position sensor, a posture sensor and a controller that performs machine control on the basis of a target surface set on the basis of target shape data, the position information of the swing structure, and the information about the posture of the work machine. When the controller becomes unable to obtain the position information of the swing structure, the controller stores swing angle information of the swing structure, the swing angle information being sensed by the posture sensor at that time. The controller prohibits execution of the machine control when the swing structure is positioned outside a swing range; and permits the execution of the machine control when the swing structure is positioned inside the swing range and when the swing structure is positioned inside the swing range again after being positioned outside the swing range.

Abstract: A work machine includes a work implement provided to a machine body, a posture sensor that senses posture information regarding the work implement, a controller configured to compute a specific position of the work implement on the basis of the posture information, set a limited area that the work implement is prohibited from entering, compute a movable distance as a distance between the limited area and the specific position of the work implement, and limit operation of the work implement according to the movable distance to prevent the work implement from entering the limited area, and an input device for inputting to the controller input information input by an operation of an operator.

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: The invention of the present application intends to provide a work machine that can improve the work performance by keeping the work state of work equipment conforming to the intention of an operator in machine control for causing the work equipment to follow an excavation target surface. For this purpose, a controller determines the work state of the work equipment on the basis of an operation input amount inputted from an operation input device and the posture of the work equipment with respect to the target surface, computes a range of an action command value of actuators in which the work state determined is kept, and corrects, within the range, the action command value of the actuators to make the distance between the work equipment and the target surface small.

Abstract: Provided is a construction machine which can promptly adjust the rotational speed of a swing motor to a target rotational speed. A controller calculates a target rotational speed of the swing motor based on input from an operation device, calculates a degree of deviation of a rotational speed detected by a rotational speed sensor from the target rotational speed, sets a target driving pressure of the swing motor according to a moment of inertia about a swing axis of a swing structure and a work device and controls a pressure adjusting device in such a manner as to reduce a difference between a driving pressure detected by a pressure sensor and the target driving pressure, when the degree of deviation is larger than a predetermined value, and controls the pressure adjusting device in such a manner as to reduce a difference between the rotational speed detected by the rotational speed sensor and the target rotational speed, when the degree of deviation is equal to or smaller than the predetermined value.

Abstract: The invention of the present application has as its object the provision of a work machine that is equipped with a function to prevent a work device thereof from going into an entry prohibited area and can satisfy both working precision and working efficiency of the work device. A controller is therefore configured to start work range limiting control to decelerate or stop an action of a machine main body or the work device when a distance between a monitor point set beforehand on the work device and the entry prohibited area decreases to a first distance, to end the work range limiting control when the distance between the monitor point and the entry prohibited area increases to a second distance greater than the first distance, and to change the second distance according to an operation amount of an operation device.

Abstract: Provided is a work machine which can increase the operation speed of an actuator by a regeneration function while securing the position control accuracy of the actuator. A controller is configured to calculate a regeneration flow rate on the basis of an input amount of an operation lever and a target actuator flow rate, subtract the regeneration flow rate from the target actuator flow rate to calculate a target actuator supply flow rate, calculate a target flow rate control valve opening amount on the basis of the target actuator supply flow rate, calculate a target pump flow rate that is equal to or higher than a total target actuator supply flow rate, control a selector valve on the basis of the input amount of the operation lever, control a flow rate control valve according to the target flow rate control valve opening amount, and control a hydraulic pump according to the target pump flow rate.

Abstract: Provided is a work machine which can achieve both of excellent operability when an operator manually operates a machine body or a work device and an accuracy of control of the machine body or the work device when a controller performs automatic control. The controller is configured to, in a case where the automatic control function selector switch gives an instruction to disable the automatic control function, adjust an opening amount of a bleed-off valve to a maximum opening amount or an opening amount corresponding to input amounts of control levers, and in a case where the automatic control function selector switch gives the instruction to enable the automatic control function, adjust the opening amount of the bleed-off valve, in at least part of an operation region of the control levers, so as to be smaller than the opening amount with the instruction to disable the automatic control function being given.

Abstract: An object of the present invention is to provide a work machine that can increase the operation speed of an actuator by a regenerating function while ensuring accuracy of position control of the actuator. For this purpose, a controller computes a target actuator supply flow rate by subtracting a regeneration flow rate from a target actuator flow rate, computes a target flow control valve opening amount on the basis of the target actuator supply flow rate, computes a target pump flow rate equal to or more than the sum of a plurality of the target actuator supply flow rates, controls flow control valves according to the target flow control valve opening amount, and controls a hydraulic pump according to the target pump flow rate.

Abstract: Both a control for limiting operation of a machine body and a control for raising engine speed are achieved when an obstacle is detected. To this end, a machine controller performs operation limiting control by conducting a control for reducing the speed of the engine when the machine body does not require engine speed increase control and an obstacle is sensed by obstacle sensors, and the machine controller performs supply flow rate reduction control for reducing the flow rates of the hydraulic fluid supplied to hydraulic actuators from a hydraulic pump when the machine body requires the engine speed increase control and an obstacle is sensed by the obstacle sensors.

Abstract: Provided is a work machine which can increase the operation speed of an actuator by a regeneration function while securing the position control accuracy of the actuator. A controller is configured to calculate a regeneration flow rate on the basis of an input amount of an operation lever and a target actuator flow rate, subtract the regeneration flow rate from the target actuator flow rate to calculate a target actuator supply flow rate, calculate a target flow rate control valve opening amount on the basis of the target actuator supply flow rate, calculate a target pump flow rate that is equal to or higher than a total target actuator supply flow rate, control a selector valve on the basis of the input amount of the operation lever, control a flow rate control valve according to the target flow rate control valve opening amount, and control a hydraulic pump according to the target pump flow rate.

Abstract: Provided is a construction machine that avoids automatic release of operation restriction involving, for example, sudden acceleration unintended by an operator even when an inclined angle of a vehicle body changes. The construction machine includes a vehicle body 50 configured to operate, 3D sensors (obstacle detection devices) 5, 6, 7, and 8 that detect an obstacle present around the vehicle body 50, an inclined angle determination device (an inclined angle detection device) 9 that detects the inclined angle of the vehicle body 50, and a vehicle body controller (a controller) 14 having an operation restriction function that performs a restriction control to restrict an operation of the vehicle body 50 when the 3D sensors (the obstacle detection devices) 5, 6, 7, and 8 detect an obstacle.

Abstract: Provided is a work machine which can achieve both of excellent operability when an operator manually operates a machine body or a work device and an accuracy of control of the machine body or the work device when a controller performs automatic control. The controller is configured to, in a case where the automatic control function selector switch gives an instruction to disable the automatic control function, adjust an opening amount of a bleed-off valve to a maximum opening amount or an opening amount corresponding to input amounts of control levers, and in a case where the automatic control function selector switch gives the instruction to enable the automatic control function, adjust the opening amount of the bleed-off valve, in at least part of an operation region of the control levers, so as to be smaller than the opening amount with the instruction to disable the automatic control function being given.

Abstract: In a hydraulic excavator 1 including a machine body 1B and a front work device 1A, when an object is detected by sensors 13a, 13b, and 13c for detecting an object around the machine body 1B, when operation limiting control for limiting the operation of at least one of the machine body 1B and the front work device 1A is enabled, or when an operation device 4 is operated, the detection of the object is notified to an operator by a first state warning, and when the operation limiting control is enabled and when the operation device 4 is not operated, the detection of the object is notified to the operator by a second state warning that is weaker in warning intensity than the first state warning. Accordingly, the botheration for the operator can be suppressed while securing the effectiveness of an alarm in periphery monitoring, and the safety performance can be enhanced.

Abstract: A work machine that can keep the control accuracy of actuators irrespective of temperature variation of a hydraulic operating fluid that passes through flow rate controllers that control the flow rates of supply to the actuators is provided. For this purpose, the flow rate controllers each have a valve body that is disposed on a main hydraulic line connecting a delivery line of a hydraulic pump and the actuator and that moves according to an operation pressure from a solenoid proportional pressure reducing valve, a sampling hydraulic line that branches from the main hydraulic line, and a temperature sensor set on the sampling hydraulic line. The controller is configured to correct a command electrical signal to the solenoid proportional pressure reducing valve according to a signal from the temperature sensor.

Abstract: Provided is a construction machine which can promptly adjust the rotational speed of a swing motor to a target rotational speed. A controller calculates a target rotational speed of the swing motor based on input from an operation device, calculates a degree of deviation of a rotational speed detected by a rotational speed sensor from the target rotational speed, sets a target driving pressure of the swing motor according to a moment of inertia about a swing axis of a swing structure and a work device and controls a pressure adjusting device in such a manner as to reduce a difference between a driving pressure detected by a pressure sensor and the target driving pressure, when the degree of deviation is larger than a predetermined value, and controls the pressure adjusting device in such a manner as to reduce a difference between the rotational speed detected by the rotational speed sensor and the target rotational speed, when the degree of deviation is equal to or smaller than the predetermined value.