Flow Control Valve Regenerative Spool for Excavator Boom
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Solution Overview
Problem
Existing flow rate control valves for construction machines experience excessive pressure loss and energy loss during the boom-down operation of large-scale excavators, leading to heat generation and decreased fuel efficiency and manipulability.
Innovation Solution
A flow rate control valve design that includes boom-up and boom-down flow rate adjustment mechanisms, utilizing regenerating poppets and booster poppets to manage hydraulic fluid flow, reducing pressure loss and allowing regenerative hydraulic fluid to be returned to the tank, thereby controlling boom drop speed and improving fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single boom spool is used to control hydraulic fluid flow during boom-down operation, then the device complexity is reduced, but excessive pressure loss and energy loss occur due to high flow rate returning to the hydraulic tank
Solution Approach 1:
The single boom spool is divided into two separate boom spools: the first boom spool handles the main hydraulic fluid flow control, while the second boom spool is specifically dedicated to regenerative hydraulic fluid flow control. This segmentation allows independent optimization of each spool's function, enabling the second spool to manage regenerative flow separately and reduce pressure loss during boom-down operation.
Solution Approach 2:
The second boom spool serves multiple functions: it controls regenerative hydraulic fluid flow during boom-down operation and can also contribute to boom-up operation when needed. This multi-functionality allows the system to reduce pressure loss during boom-down while maintaining adequate flow control capability during boom-up, resolving the energy loss problem without significantly increasing overall system complexity.
2Device complexity
If hydraulic fluid is returned directly to the hydraulic tank during boom-down operation, then the system simplicity is maintained, but heat generation increases and fuel efficiency decreases due to excessive pressure loss
Solution Approach 1:
Instead of directly discarding (returning to tank) the hydraulic fluid during boom-down operation, the system recovers energy by redirecting the regenerative hydraulic fluid through the second boom spool back to the boom cylinder. This recovery process reduces pressure loss and heat generation, improving fuel efficiency while maintaining system simplicity through the additive second spool configuration.
3Device complexity
If the first boom spool and second boom spool serve as return passages during boom-down operation, then the existing valve structure is utilized, but excessive pressure loss occurs due to high flow rate returning to the hydraulic tank
Solution Approach 1:
The return passage function is segmented between the two boom spools: the first boom spool continues to handle main hydraulic fluid return, while the second boom spool is specifically assigned to handle regenerative hydraulic fluid return. This segmentation allows the high flow rate of regenerative fluid to be managed separately, reducing the burden on individual spools and minimizing pressure loss and energy loss during boom-down operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces pressure loss and heat generation, enhances fuel efficiency, and increases boom-down operation speed, improving manipulability by regenerating hydraulic fluid and controlling boom drop speed during the boom-down operation.
Implementation Method 1
a regenerating poppet 37 mounted on one side of the inside of the first boom spool 2 to allow a part of the hydraulic fluid being fed back from the large chamber of the boom cylinder to join a hydraulic fluid being supplied to a small chamber of the boom cylinder as a regenerative hydraulic fluid
Implementation Method 2
a boom booster poppet 32 mounted on the first boom valve block 1 in such a manner as to be positioned on a path along which the hydraulic fluid being fed back from the larger chamber of the boom cylinder returns to the hydraulic tank via the first boom spool 2 during the boom-down operation, and configured to generate a back pressure to control the boom drop speed
Implementation Method 3
control the supply of the hydraulic fluid to a hydraulic actuator from first and second hydraulic pumps
Implementation Method 4
a valve spring 3 built in a cover 4 mounted at one side of the first boom valve block 1
Data Source
Figure 1
Figure 2
AI summary
Disclosed is a flow control valve for construction machinery, the flow control valve being adapted to reduce pressure loss due to flow on return to a hydraulic tank during the boom-down operation of a large-scale excavator. The flow control valve for construction machinery according to the present invention comprises: first and second boom spools which are respectively coupled to first and second boom valve blocks, and which regulate working fluid that is respectively supplied from first and second hydraulic pumps to a boom cylinder during direction reversal; a boom-up flow-adjusting means which, in direction reversal of the first and second boom spools for boom-up drive, supplies working fluid from the first and second hydraulic pumps into a large chamber of the boom cylinder via the first and second boom spools respectively, and causes part of the flow of working fluid from the second hydraulic pump to pass via the second boom spool so as to be combined with working fluid being supplied from the first hydraulic pump to the large chamber of the boom cylinder due to direction reversal of the first boom spool; and a boom-down flow-adjusting means which, in direction reversal of the first and second boom spools for boom-down drive, causes part of the flow of working fluid coming back from the large chamber of the boom cylinder to return to the hydraulic tank via the first and second boom spools respectively, and causes part of the flow of working fluid coming back from the large chamber of the boom cylinder to combine as respective regenerative flows for working fluid on the small chamber side of the boom cylinder.