Samsung Heavy Industries Co., Ltd.

Volvo Construction Equipment Korea Co., Ltd.

In Taek Nam

Geon Hwang

Jin Han Lee

Myung Hoon Song

Myoung Hoon Song

Disclosed is automatic fluid pressure-intensifying apparatus and method of a hydraulic traveling device for increasing a traveling capability or a pulling capability of a heavy equipment by changing a relief pressure in a hydraulic circuit under the state that a working device of the heavy equipment does not operate and a traveling device only operates. In the automatic fluid pressure-intensifying apparatus of the hydraulic traveling device, a first control valve selectively changes a flow direction of a hydraulic fluid being supplied by a hydraulic pump toward a traveling motor of the heavy equipment. Further, a second control valve selectively changes the flow direction of the hydraulic fluid being supplied by the hydraulic pump toward a working device of the heavy equipment. A relief valve restricts an allowable maximum pressure in a hydraulic circuit. A first pressure switch detects a pressure in a first pilot line of the first control valve, and a second pressure switch detects a pressure in a second pilot line of the second control valve. A controller judges whether the controller will intensify the allowable maximum pressure in the hydraulic circuit or not by receiving signals generated from the first pressure switch and the second pressure switch. A solenoid valve changes an allowable maximum pressure of the relief valve into a pressure corresponding to a signal generated by the controller.

Automatic fluid pressure-intensifying apparatus and method of a

Disclosed is an apparatus for increasing the operating capability of a construction machine during a fine operation mode and a method for the same. The apparatus being capable of preventing a merged hydraulic fluid from being supplied into a hydraulic actuator and increasing the pressure of the hydraulic fluid being supplied into the hydraulic actuator during the fine operation mode. The apparatus includes a detector that detects the RPM count of the engine of the construction machine and determines whether the engine is switched into the fine operation mode. A first anti-confluence valve and a second anti-confluence valve prevent a first hydraulic fluid supplied into the first actuator and a second hydraulic fluid supplied into the second actuator from merging while either the first actuator or the second actuator is operating. An anti-confluence relay turns the first anti-confluence valve and the second anti-confluence valve on/off. Finally, a controller turns the anti-confluence relay on/off in accordance with a signal generated by the detector.

Apparatus for improving the operating capability of a construction

A device for controlling a breaker in construction vehicles is disclosed. The device includes a control circuit provided with a power supply, a first solenoid valve used for controlling the breaker, and a second solenoid valve used for boosting the relief pressure of the circuit. The device also includes a control switch and a select switch. The control switch is installed in a control lever and is handled by an operator in order to selectively open or close the control circuit. Meanwhile, the select switch is connected between the control switch, power supply and first and second solenoid valves. The select switch selectively connects the power supply to the first or second solenoid valve in order to select either of the breaker and pressure boosting operations, which are commonly controlled by the control switch.

Device for controlling breaker in construction vehicles

A control device for a travelling system in construction vehicles is disclosed. The control device applies the pilot pressure of the pilot pump to the spool of the directional control valve separately from the travelling control pedal, thus automatically controlling operation of the directional control valve. However, the manual control mode performed by the travelling control pedals has priority over the automatic control mode. The control device has a proportional control valve, which applies the pilot pressure of the pilot pump to the spool in response to an input current signal. A pressure sensor checks the pilot pressures, which are generated by both the travelling control pedals and the proportional control valves and act on the spool. A controller receives a signal indicative of the pilot pressures checked by the pressure sensor and outputs the current signal to the proportional control valve.

Growing community of inventors

Namyangju, South Korea

In Taek Nam