Hydraulic Suspension Accumulator Isolation for Faster Vehicle Lifting
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Solution Overview
Problem
Agricultural vehicles equipped with hydraulic suspensions face issues such as slow response times when lifting after complete lowering, due to the need to simultaneously pressurize the piston chamber and the hydraulic accumulator, which can lead to overpressurization and potential damage.
Innovation Solution
Implementing a control valve system that isolates the hydraulic accumulator when the vehicle reaches predetermined height thresholds, near the minimum or maximum height, to prevent complete discharge and ensure quicker responses to opposite commands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the hydraulic accumulator is connected to the piston chamber to dampen ground stress, then the suspension system can absorb shocks, but the accumulator may be overpressurized and damaged when the vehicle is completely lowered
Solution Approach 1:
The control system preemptively isolates the hydraulic accumulator from the piston chamber when the vehicle approaches complete lowering, preventing the accumulator from being subjected to excessive pressurization before damage can occur. This preliminary protective action avoids the harmful effect of overpressurization.
Solution Approach 2:
A control valve is introduced as an intermediary element between the piston chamber and the hydraulic accumulator. This valve mediates the connection by selectively opening or closing the flow path, allowing the accumulator to be isolated from the piston chamber when necessary to prevent overpressurization damage.
2Speed
If the hydraulic pump sends oil to both the piston chamber and hydraulic accumulator simultaneously during lifting, then the vehicle can be raised, but the response time is delayed by up to seven seconds
Solution Approach 1:
The control system maintains the hydraulic accumulator in a pre-charged, ready state by preventing complete discharge during previous lowering operations. When lifting is commanded, the accumulator is already prepared to immediately supplement oil flow to the piston chamber, eliminating the seven-second delay.
Solution Approach 2:
The system dynamically switches the state of the control valve based on the vehicle's position and operational phase. During normal operation, the accumulator remains connected to provide damping. During complete lowering, the accumulator is isolated to prevent overpressurization. This dynamic control optimizes both response time and safety.
3Ease of operation
If the vehicle allows complete lowering to 0% height, then the operator achieves full lowering, but the hydraulic accumulator becomes completely depressurized and vulnerable to damage
Solution Approach 1:
The control system continuously monitors the vehicle's height position and uses this feedback to control the state of the isolation valve. When the vehicle approaches complete lowering (0% height), the feedback signal triggers the valve to close, isolating the accumulator before it can be completely depressurized or overpressurized, thus protecting it while still allowing near-complete lowering.
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
This solution allows for a prompt response to lifting commands after complete lowering, while preventing damage to hydraulic accumulators by avoiding excessive pressurization, thus enhancing the durability and responsiveness of the suspension system.
Implementation Method 1
the pressurized circuit is connected to a hydraulic accumulator
Implementation Method 2
Since hydraulic oil is incompressible, in order to dampen ground stress, the pressurized circuit is connected to a hydraulic accumulator
Implementation Method 3
provide a control valve for the connection of the hydraulic accumulator associated with one of the chambers of the hydraulic actuator
Implementation Method 4
a hydraulic pump is arranged to draw oil and send it to the filling chamber
Data Source
Figure 1
Figure 2a~2b
Figure 3
AI summary
Agricultural vehicle comprising a height-adjustable hydraulic suspension system comprising a double acting actuator (SA), comprising a first (PC) and a second chamber (RC) alternately arranged to expand and contract, causing the vehicle to be raised or lowered, a valve (V1) for controlling the supply of said first or second chamber, at least one hydraulic accumulator (ACCC1, ACC2) operationally connected to one of said first or second chamber, a isolation valve (V2, V3) for isolating said first hydraulic accumulator, processing means (CU) configured to control the complete contraction of one of said first or second chambers in response to a complete raising or lowering command of the vehicle, and to control said isolation valve (V2, V3), so as to isolate said hydraulic accumulator when a vehicle height value reaches a first predetermined threshold (Th1, Th2).