Samsung Heavy Industries Co., Ltd.

Volvo Construction Equipment Korea Co., Ltd.

Tae Seung Chung

Yang Goo Lee

Yeon Ho Kim

A variable-regeneration directional control valve for construction vehicles is disclosed. The control valve has a pressure control means for controlling the opposite pressure caused by elasticity of a valve spring. The opposite pressure acts on one end of a regeneration switching spool, while a self pressure (hydraulic pressure of pressurized fluid output from a pump) acts on the other end of the regeneration switching spool and thereby moves the spool. In the preferred embodiment, the means is a pressure control piston, which is provided on the end of the valve spring. The pressure control piston receives an outside control signal through an electronic proportional control valve and thereby continuously moves. The electronic proportional control valve outputs pressurized fluid in proportion to a current amount of the outside control signal.

Variable-regeneration directional control valve for construction vehicles

A fluid joining device for construction vehicles is disclosed. The device has a bypass line control valve which is mounted to a second center bypass line of the second pump. The bypass line control valve normally opens the second center bypass line but selectively closes the second center bypass line in response to a pilot pressure. A second pilot line control valve is mounted to a second pilot line and controls the second pilot line in response to an outside signal. The second pilot line extends from the first pilot line control valve and selectively drives the first pilot line control valve. The device selectively performs the fluid joining function in accordance with operational conditions of the actuators, thus smoothly operating the actuators and improving operational effect of the construction vehicle.

Fluid joining device for power construction vehicles

A return fluid regeneration device for construction vehicles is provided. The regeneration device includes an orifice disposed on a return-side internal line of a directional control valve of an actuator. A regeneration line is arranged between the return-side internal line and a return line extending to a return tank and is further selectively connected to the return-side internal line during a weight operation of the actuator. A regeneration branch line is branched from the return-side internal line and is connected to a supply-side internal line of the valve, thus selectively feeding the return fluid from the return-side internal line to the supply-side internal line and thereby regenerating the return fluid. First and second check valve are also provided on the regeneration line and branch line, respectively. The regeneration device regulates the moving speed of the actuator while simultaneously preventing the generation of high pressure in a fluid supply line.

Growing community of inventors

Pusan, South Korea

Tae Seung Chung