Abstract: An apparatus for and a method of controlling the engine RPM in hydraulic construction equipment, being capable of detecting a neutral valve position corresponding to the idle state of the construction equipment and controlling the engine to drive at a low RPM while the construction equipment is in its idle state, thereby achieving a reduced noise generation and reduced fuel consumption.

Abstract: A lumber door and manufacturing method thereof which is constructed by perforating the plurality of the pipe inserting holes at each of the unit lumbers in the direction of transverse and thickness with the predetermined diameter, depth and location, inserting the plurality of the metal pipes into the pipe inserting holes, and assembling the unit lumbers and the pipes one by one with spreading over the adhesive resin to both of the surfaces of the pipes and to the contacting surfaces so as to be adhered each other to form a single integrally formed lumber door, and pressing at once the plurality of the lumber door assembly piled up one above one within a press machine for about two hours, and forming the engraving patterns on the surface of the lumber door within the region where pipes are not arranged, so that a single integrally formed lumber door can be prevented or excluded from the bending, twisting and cracking phenomena due to the changes of the temperature and the humidity of the environment, thereby

Abstract: A lumber door and manufacturing method thereof which is constructed by perforating the plurality of the pipe inserting holes at each of the unit lumbers in the direction of transverse and thickness with the predetermined diameter, depth and location, inserting the plurality of the metal pipes into the pipe inserting holes, and assembling the unit lumbers and the pipes one by one with spreading over the adhesive resin to both of the surfaces of the pipes and to the contacting surfaces so as to be adhered each other to form a single integrally formed lumber door, and pressing at once the plurality of the lumber door assembly piled up one above one within a press machine for about two hours, and forming the engraving patterns on the surfaces of the lumber door within the region where pipes are not arranged, so that a single integrally formed lumber door can be prevented or excluded from the bending, twisting and cracking phenomena due to the changes of the temperature and the humidity of the environment, thereby