FLUID PRESSURE CIRCUIT AND WORK MACHINE

• Main Authors: KANENAWA HIRONARI, IMOTO SHUHEI, HATA YOSHIHIKO, KISHIDA KOJI, TOYODA MITSUHIRO, MATOBA NOBUAKI
• Format: Patent
• Language: English; Japanese
• Published: 08.12.2016
• 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 provide a fluid pressure circuit capable of ensuring a necessary pump flow rate even when working fluid is accumulated in an accumulator with a simple structure, and capable of properly setting operation speed of a fluid pressure cylinder, and to provide a work machine.SOLUTION: Working fluid extracted from the head side of a boom cylinder 7c1 is accumulated in a first accumulator 46 through a control valve 61, the control valve changing a communication amount between the head side of the boom cylinder 7c1 and the first accumulator 46 according to an operation amount of a lever, differential pressure before and after the control valve 61, and accumulator pressure. Working fluid extracted from the head side of a boom cylinder 7c2 is returned to the boom cylinders 7c1, 7c2 through a main control valve 62, the main control valve disconnecting communication between the head sides of boom cylinders 7c1, 7c2 and communicating between the head side of the boom cylinder 7c2 and the rod sides of the boom cylinders 7c1, 7c2 in a case where the working fluid is accumulated in the first accumulator 46.SELECTED DRAWING: Figure 1 【課題】より簡素な構成で作動流体をアキュムレータに蓄圧させているときも必要なポンプ流量を確保できるとともに、流体圧シリンダの作動速度を適切に設定できる流体圧回路および作業機械を提供する。【解決手段】ブームシリンダ7c1のヘッド側と第１のアキュムレータ46との連通量をレバーの操作量、制御弁61の前後差圧およびアキュムレータ圧に応じて変化させる制御弁61を介してブームシリンダ7c1のヘッド側から押し出した作動油を第１のアキュムレータ46に蓄圧させる。第１のアキュムレータ46に蓄圧させるときにブームシリンダ7c1，7c2のヘッド側間の連通を遮断するとともにブームシリンダ7c2のヘッド側とブームシリンダ7c1，7c2のそれぞれのロッド側とを連通するメイン制御弁62を介して、ブームシリンダ7c2のヘッド側から押し出した作動油をブームシリンダ7c1，7c2に再生する。【選択図】図１