Hydraulic recovery system for construction machine and construction machine using the same
AssigneeHitachi Construction Machinery Co., Ltd.
InventorsNaoto Sannomiya, Sotaro Tanaka
Life of this patent
Estimating the term…
Abstract
A hydraulic recovery system for a construction machine comprises a recovery valve for supplying at least a part of a hydraulic fluid from a rod-side line, through which the hydraulic fluid is drained from a rod-side hydraulic chamber of an arm hydraulic cylinder, to a bottom-side line through a variable throttle, and a throttle valve for returning the remaining part of the hydraulic fluid, which is not recovered, from the rod-side line to a hydraulic reservoir through a variable throttle. Opening areas of those variable throttles are controlled depending on an arm flow rate supplied from hydraulic pumps to the arm hydraulic cylinder.
Claims20
A hydraulic recovery system for a construction machine, said hydraulic recovery system being provided in a hydraulic drive system for driving a plurality of actuators by a hydraulic fluid supplied from at least one hydraulic pump in the construction machine, said hydraulic recovery system comprising:
- a first line for supplying the hydraulic fluid to the bottom side of at least one particular hydraulic cylinder among said plurality of actuators;
- a second line for draining the hydraulic fluid from the rod side of said particular hydraulic cylinder;
- recovery valve means for supplying at least a part of the hydraulic fluid from said second line to said first line;
- a second variable throttle provided in said recovery valve means and supplying at least said part of the hydraulic fluid from said second line to said first line at a desired opening;
- throttle valve means for returning the remaining part of the hydraulic fluid, which is not recovered, from said second line to a hydraulic reservoir;
- a first variable throttle provided in said throttle valve means and returning the remaining part of the hydraulic fluid, which is not recovered, to said hydraulic reservoir at a desired opening;
- and
- control means for controlling respective opening areas of said first variable throttle and said second variable throttle depending on an actuator flow rate supplied from said hydraulic pump to said particular hydraulic cylinder.
A construction machine comprising:
- a lower travel structure;
- an upper swing structure rotatably mounted on said lower travel structure;
- a multi-articulated front mechanism rotatably coupled to said upper swing structure and including a boom, an arm and a bucket;
- a plurality of actuators including a boom hydraulic cylinder, an arm hydraulic cylinder and a bucket hydraulic cylinder for driving said boom, said arm and said bucket, respectively;
- a first line for supplying a hydraulic fluid to the bottom side of at least one particular hydraulic cylinder among said plurality of actuators;
- a second line for draining the hydraulic fluid from the rod side of said particular hydraulic cylinder;
- recovery valve means for supplying at least a part of the hydraulic fluid from said second line to said first line through a second variable throttle;
- throttle valve means for returning the remaining part of the hydraulic fluid, which is not recovered, from said second line to a hydraulic reservoir through a first variable throttle;
- and
- control means for controlling respective opening areas of said first variable throttle and said second variable throttle depending on an actuator flow rate supplied from said hydraulic pump to said particular hydraulic cylinder.
Dependencies are inferred from the claim text.