Hydropneumatic Suspension Toroid Pressure Control via Pilot Valve Segmentation
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Solution Overview
Problem
Existing hydropneumatic suspension systems for vehicles with variable loads face challenges in efficiently regulating pressure levels in toroid chambers, particularly in maintaining high pressure at low cylinder pressure and reducing it at medium and high pressure levels, while also requiring a simple and cost-effective design.
Innovation Solution
The use of two 2/2-port directional control valves in the inlet and drain lines of hydraulic cylinders, combined with a two-stage pressure control valve downstream of a pilot valve, allows for regulating high pressure levels in toroid chambers at low cylinder pressure and reducing them at medium and high pressure levels, utilizing throttles and check valves to manage volume flows and maintain pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pressure control valve is used to regulate pressure in toroid chambers, then pressure levels can be maintained, but the system becomes complex and expensive
Solution Approach 1:
The pressure control valve is divided into two separate 2/2-port directional control valves, each responsible for different pressure regulation tasks. This segmentation simplifies the overall system architecture while maintaining effective pressure control in the toroid chambers.
Solution Approach 2:
A pilot valve is introduced as an intermediary component that uses the cylinder pressure signal to control the main pressure control valve. This indirect control mechanism simplifies the main valve design while achieving sophisticated pressure regulation through the pilot valve's mediation.
2Device complexity
If a single pressure control valve is used, then the system is simpler, but it cannot effectively regulate high pressure at low cylinder pressure and reduce pressure at medium and high pressure levels
Solution Approach 1:
The pressure control system is made dynamic through the pilot valve, which automatically adjusts the control pressure based on the cylinder pressure level. This dynamic adaptation allows the system to provide high pressure when cylinder pressure is low and reduce pressure when cylinder pressure is medium or high, all within a unified control architecture.
Solution Approach 2:
The pilot valve receives feedback from the cylinder pressure and uses this information to modulate the control pressure to the main pressure control valve. This feedback mechanism enables the system to adapt its pressure output according to the actual load conditions, achieving versatile pressure regulation across different operating ranges.
3Speed
If the pump operates at maximum capacity during control actions, then response speed improves, but energy consumption increases
Solution Approach 1:
The pump operates at maximum capacity only during transient control actions when pressure adjustments are needed, rather than continuously. The pressure control valve maintains system pressure during steady-state operation, allowing the pump to cycle on and off as needed, thus achieving fast response when required while minimizing overall energy consumption.
Solution Approach 2:
The pressure control valve pre-maintains the required pressure in the toroid chambers during normal operation, so that when control actions are needed, the pump only needs to make incremental adjustments rather than building pressure from scratch. This preliminary pressure maintenance enables faster response times while reducing the total energy required for pressure control.
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 configuration ensures efficient regulation of pressure levels in toroid chambers, allowing the pump to operate at maximum capacity during control actions, while maintaining simplicity and cost-effectiveness in construction.
Implementation Method 1
a two-stage pressure control valve inserted in the inlet line to the toroid chambers of the spring cylinders. This two-stage pressure control valve is connected downstream of a pilot valve that is dependent on the pressure level in the inlet line
Implementation Method 2
the pressure level in the toroid chambers of the hydraulic cylinders is regulated by way of a two-stage pressure control valve inserted in the inlet line to the toroid chambers
Implementation Method 3
two 2/2-port directional control valves that are inserted in the inlet and drain lines of the cylinder chambers of the hydraulic cylinders
Implementation Method 4
connected to a pump by way of pressure lines with the pressure level in the toroid chambers being regulated
Data Source
AI summary
A device for controlling suspension performance in a vehicle having variable loads on an axle, a level control system, and a hydropneumatic suspension apparatus between unsprung and sprung masses. The device includes at least one double-acting hydraulic cylinder having a cylinder chamber and a toroid chamber, a pump, a cylinder chamber inlet line connecting the pump to the cylinder chamber, a toroid chamber inlet line connecting the pump to the toroid chamber, and a cylinder chamber outlet line. Two 2/2 port directional control valves configured to regulate the level control system are disposed in the cylinder chamber inlet line and the cylinder chamber outlet line, respectively. A pilot valve is disposed in the toroid chamber inlet line and dependent on a pressure level in the cylinder chamber inlet line. A two-stage pressure control valve is disposed downstream of the pilot valve and configured to regulate a toroid pressure level in the toroid chamber as a function of a cylinder pressure level in the cylinder chamber so that the toroid pressure is increased when the cylinder pressure is low.