Energy recycling system for a construction apparatus

Abstract

An energy recycling system is disclosed. When a construction apparatus performs a combined operation of a boom down operation and an arm out operation, hydraulic energy returned in the boom down operation is recycled for the arm out operation by the energy recycling system. An energy recycling system for a construction apparatus according to the present invention includes: a first hydraulic pump; a second hydraulic pump; an arm cylinder including a low pressure chamber connected to the first hydraulic pump through an arm out supply passage; an arm out return passage connecting a high pressure chamber of the arm cylinder to a hydraulic tank; a boom cylinder including a low pressure chamber connected to the second hydraulic pump through a boom down supply passage; a boom down return passage connecting a high pressure chamber of the boom cylinder to a hydraulic tank; a joining and recycling passage connecting the boom down return passage and the arm out supply passage to each other in parallel; a recycling passage connecting the boom down return passage and the boom down supply passage to each other in parallel; and a plurality of detecting means that detect pressure of the arm cylinder and pressure of the boom cylinder, respectively, to determine whether a hydraulic fluid, returned from the boom cylinder in a combined operation of a boom down operation and an arm out operation, is recycled.

Description

technical field [0001] The present invention relates to an energy recycling system for a construction machine capable of regenerating energy when the construction machine performs combined operations of boom down and stick out. More particularly, the present invention relates to an energy recycling system for a construction machine capable of regenerating hydraulic energy returned by a boom lowering operation during an arm extending operation. Background technique [0002] Such as figure 1 As shown, the hydraulic system according to the prior art for engaging the boom cylinder and the stick cylinder with each other includes: [0003] first and second variable displacement hydraulic pumps (hereinafter referred to as "first and second hydraulic pumps") 1 and 2, the first and second hydraulic pumps 1 and 2 are connected to an engine (not shown); [0004] stick cylinder 3, which is connected to the first hydraulic pump 1; [0005] A control valve 4, which is installed in the ...

AI Technical Summary

Problems solved by technology

In this case, the hydraulic fluid supplied from the second hydraulic pump 2 to the boom cylinder 5 cannot be supplied to stick cylinder 3

[0013] Therefore, the conventional hydraulic system has a problem that the workability of the arm extension operation is relatively significantly deteriorated during the combined operation of the boom lowering and the arm extension as compared with the operation of only the arm extension

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