Abstract: An engine control system for a construction machine is disclosed, which can compulsorily stop engine driving when an attachment or the like malfunctions against an operator's intention during the operation of an excavator or the like. The engine control system includes a first step of determining whether pilot signal pressure, which is detected when at least one of an operation lever and a traveling pedal for respectively operating an attachment, a swing device, and a traveling device is operated, exceeds a first set pressure, and a second step of determining whether the pressure on the outlet side of a main hydraulic pump exceeds a second set pressure, wherein if the pilot signal pressure detected in the first step does not exceed the first pressure and the pressure of the main hydraulic pump detected in the second step exceeds the second pressure, engine driving is compulsorily stopped by means of a control signal from the controller.

Abstract: Disclosed is a construction machine with a floating function for performing soil preparation or the like for flattening the ground or the like using a dozer blade.

Abstract: An improved double check valve for a construction machine is provided, which can greatly reduce noise and hunting phenomenon by making check valves open and close within a predetermined time difference to correspond to pressure drops that occur due to an external load when a dozer blade working device is operated.

Abstract: An engine control system for a construction machine is disclosed, which can compulsorily stop engine driving when an attachment or the like malfunctions against an operator's intention during the operation of an excavator or the like. The engine control system includes a first step of determining whether pilot signal pressure, which is detected when at least one of an operation lever and a traveling pedal for respectively operating an attachment, a swing device, and a traveling device is operated, exceeds a first set pressure, and a second step of determining whether the pressure on the outlet side of a main hydraulic pump exceeds a second set pressure, wherein if the pilot signal pressure detected in the first step does not exceed the first pressure and the pressure of the main hydraulic pump detected in the second step exceeds the second pressure, engine driving is compulsorily stopped by means of a control signal from the controller.

Abstract: An improved double check valve for a construction machine is provided, which can greatly reduce noise and hunting phenomenon by making check valves open and close within a predetermined time difference to correspond to pressure drops that occur due to an external load when a dozer blade working device is operated.