HYDRAULIC CONTROL DEVICE

• Main Authors: YAMASHITA SHOJI, OUCHI TATSURO, TANAKA TETSUJI, HYODO KOJI, MIYAMOTO TAISUKE
• Format: Patent
• Language: English; Japanese
• Published: 06.08.2015
• Subjects: BLASTING; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR; DREDGING; FIXED CONSTRUCTIONS; FLUID-PRESSURE ACTUATORS; FLUID-PRESSURE ACTUATORS, e.g. SERVO-MOTORS; FOUNDATIONS; HEATING; HYDRAULIC ENGINEERING; HYDRAULICS OR PNEUMATICS IN GENERAL; LIGHTING; MECHANICAL ENGINEERING; SOIL SHIFTING; SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; WEAPONS

PROBLEM TO BE SOLVED: To precisely prevent an engine stall from occurring by unloading a hydraulic pump.SOLUTION: A hydraulic control device includes: auxiliary machine operation detection means of detecting an auxiliary machine being in operation for a hydraulic pump 131 for a machine; first determination means of determining whether discharge pressure detected by discharge pressure detection means 131P is higher than first predetermined pressure; second determination means of determining whether the load of the operation, detected by the auxiliary machine operation detection means, placed on an engine 190 is higher than a predetermined value; condition determination means of determining that an unloading condition is met when the first determination means determines that the discharge pressure is higher than the first predetermined pressure and the second determination means determines that the load of the operation of the auxiliary machine placed on the engine 190 is higher than the predetermined value; and control means of releasing oil pressure discharged from the hydraulic pump by unloading means to a tank 139 when the condition determination means determines that the unloading condition is met. 【課題】油圧ポンプをアンロードさせることで、精度よくエンジンストールの発生を防止する。【解決手段】油圧制御装置は、作業機用の油圧ポンプ１３１において、補機の動作を検出する補機動作検出手段と、吐出圧検出手段１３１Pにより検出された吐出圧が第１所定圧力よりも高いか否かを判定する第１判定手段と、補機動作検出手段により検出された動作によって該エンジンに作用する負荷が所定値よりも高いか否かを判定する第２判定手段と、第１判定手段により、吐出圧が第１所定圧力よりも高いと判定され、かつ、第２判定手段により、補機の動作によってエンジン１９０に作用する負荷が所定値よりも高いと判定されたとき、アンロード条件が成立していると判定する条件判定手段と、条件判定手段によりアンロード条件が成立していると判定されたとき、アンロード手段により該油圧ポンプから吐出された圧油をタンク１３９へ逃がす制御手段とを備える。【選択図】図２