Abstract: When an engine is started in a state where a support member of a multi-coupler is attached to a mating support member, the pressure of hydraulic oil increases in a detection target pipeline part. A pressure detection unit detects the pressure of the hydraulic oil in the detection target pipeline part. A connection state determining unit determines whether a tank-side pipeline part and a motor-side pipeline part are connected to each other, based on the pressure. When the connection state determining unit determines that the tank-side pipeline part and the motor-side pipeline part are not connected to each other in a state where the engine is started, a pressure increase suppression unit carries out an operation for suppressing an increase in the pressure of a hydraulic motor.

Abstract: Provided is a work machine capable of effectively discharging air from a hydraulic circuit of a winch unit capable of applying braking to a winch drum by receiving a working oil. The work machine includes: a winch unit having a winch drum, a winch motor, a cylinder portion and a clutch portion; a hydraulic sources; a braking operating unit; a brake valve; a connecting portion; and a throttle portion. The throttle portion includes an opening having an opening diameter that is set so as to hold a pressure in a positive oil chamber for generating a brake force applied to the winch drum and to discharge a working oil from the positive oil chamber.

Abstract: A control device for a construction machine according to the present invention is configured so that in the construction machine provided with an automatic stop function which automatically stops an engine by an engine controller upon a predetermined automatic stop condition being met, and a hydraulic lock function which sets a hydraulic actuator locked in an inactive state by a hydraulic lock controller, there is provided a restart switch, where after an automatic stop of the engine, when the restart switch is operated, a restart command is transmitted to the engine controller via a route independently of that of an engine switch and independently of a hydraulic unlock condition, and the engine is restarted.

Abstract: An engine control device for a construction machine of the present invention is configured so that the engine control device comprises an engine as a power source, a controller for performing an automatic stop control to automatically stop the engine when a predetermined automatic stop condition is met, a water temperature sensor for detecting a cooling water temperature of the engine, and that after start-up of the engine, even if the automatic stop condition is met, the engine is not automatically stopped until the detected water temperature reaches a predetermined value or more to complete a warm-up operation. The engine control device is also configured so that before the engine is automatically stopped, a cool-down operation of the engine is performed as required and after the engine is stopped, the engine is restarted as required and the warm-up operation is performed.

Abstract: An engine control device for a construction machine of the present invention is configured so that an engine is automatically stopped by an engine controller under the condition that a remote control valve is not operated, an allowance time has passed and a gate lever for opening and closing a gateway for an operator is opened, and in which an average value of the last gate lever opening times is obtained and the allowance time is automatically set based on the average value.

Abstract: A control device for a construction machine according to the present invention is configured so that in the construction machine provided with an automatic stop function which automatically stops an engine by an engine controller upon a predetermined automatic stop condition being met, and a hydraulic lock function which sets a hydraulic actuator locked in an inactive state by a hydraulic lock controller, there is provided a restart switch, where after an automatic stop of the engine, when the restart switch is operated, a restart command is transmitted to the engine controller via a route independently of that of an engine switch and independently of a hydraulic unlock condition, and the engine is restarted.

Abstract: An engine control device for a construction machine of the present invention is configured so that the engine control device comprises an engine as a power source, a controller for performing an automatic stop control to automatically stop the engine when a predetermined automatic stop condition is met, a water temperature sensor for detecting a cooling water temperature of the engine, and that after start-up of the engine, even if the automatic stop condition is met, the engine is not automatically stopped until the detected water temperature reaches a predetermined value or more to complete a warm-up operation. The engine control device is also configured so that before the engine is automatically stopped, a cool-down operation of the engine is performed as required and after the engine is stopped, the engine is restarted as required and the warm-up operation is performed.

Abstract: An load moment indicator, in a crane provided with hoist means of a main side and an auxiliary side, including a calculator in which a reference value if a rated load determined by the stability of a crane or the like is preset, a hoist load of the other side is converted into a load component of its own side, and the converted value is subtracted from a reference value of its own side to thereby obtain a rated load of own side, or in which a tolerant load that can be suspended by the other side is converted into a load component of its own side on the basis of a base of a reference value of the other side, and the converted value is compared with the reference value of its own side to select a lower value. Thereby, it is possible to make the most of the suspending ability of the main side and the auxiliary side and for an operator to grasp clearly a tolerance of the hoist load.

Abstract: An load moment indicator, in a crane provided with hoist means of a main side and an auxiliary side, including a calculator in which a reference value if a rated load determined by the stability of a crane or the like is preset, a hoist load of the other side is converted into a load component of own side, and the converted value is subtracted from a reference value of own side to thereby obtain a rated load of own side, or in which a tolerant load that can be suspended by the other side is converted into a load component of own side on the basis of a base of a reference value of the other side, and the converted value is compared with the reference value of own side to select a lower value. Thereby, it is possible to make the most of suspending ability of the main side and the auxiliary side and to grasp clearly a tolerance of the hoist load by an operator.