Piston Valve Assembly Coupling and Damping Control
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Solution Overview
Problem
The existing piston valve assembly in continuous damping control dampers experiences reliability issues in coupling between the piston rod and piston valve assembly, leading to unstable damping force control, particularly in the lower speed range, due to wear and tear causing key and groove damage, which affects vehicle driving performance.
Innovation Solution
A piston valve assembly design featuring a stopper with a through-hole and supporting portion for increased contact surface area, combined with a core assembly having slots to reduce magnetic field intensity and damping force, enhancing coupling reliability and adjusting damping properties for improved vehicle performance in the lower speed range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a key and groove coupling structure is used to connect the piston rod and piston valve assembly, then the assembly can be coupled together, but the key and groove wear away over time leading to reduced reliability and unstable damping force control
Solution Approach 1:
The coupling structure is divided into multiple segments: the piston rod has an external groove, the piston valve assembly has an internal groove, and a stopper with a protrusion fits into these grooves. This segmentation distributes the coupling function across multiple elements, preventing single-point wear and improving reliability.
Solution Approach 2:
The stopper is inserted into the piston rod through the external groove, and the piston valve assembly is then inserted into the stopper through the internal groove. This nested arrangement creates a multi-layered coupling structure where each component fits within the previous one, enhancing structural integrity and preventing wear-induced failure.
2Reliability
If the damping force is increased to improve vehicle stability, then the damping performance improves, but the driving comport deteriorates in the lower speed range
Solution Approach 1:
The damping force is made dynamic rather than fixed. The piston valve assembly adjusts the damping force based on piston velocity: at high velocities (tuning mode), the damping force is high for stability; at low velocities (cruising mode), the damping force is reduced for comfort. This dynamic adjustment resolves the contradiction between stability and comfort.
Solution Approach 2:
The damping parameter is changed based on operating conditions. By varying the damping force according to piston velocity, the system transitions between different damping states. This parameter change allows the damper to provide high damping when needed for stability and low damping when comfort is prioritized, eliminating the need to choose between the two opposing requirements.
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 design stabilizes the coupling between the piston rod and piston valve assembly, ensuring consistent damping force control and enhancing vehicle driving performance by reducing damping force intensity in the lower speed range, thereby improving overall vehicle comport.
Implementation Method 1
a core assembly which has a solenoid coil therein
Implementation Method 2
The MR fluid contains metallic particles of about 3 ̃10 μm and has a property that an apparent viscosity thereof is changed by magnetic field generated around it
Implementation Method 3
The damper functions to absorb the free vibration of the chassis spring by converting vertical kinetic energy into heat energy
Data Source
AI summary
The present invention relates to a piston valve assembly which is used in a continuous damping control damper using magneto-rheological fluid. The piston valve assembly is coupled with an end of the piston rod, and a stopper having a flat upper surface which is surface-contacted with an upper plate is disposed between a core assembly and the upper plate, thereby properly dispersing a force applied to the piston rod.According to the present invention, the reliability and stability in the coupling between the piston rod and the piston valve assembly can be increased, thereby stably controlling the damping force of the damper. Further, the slot is formed in the core of the piston valve assembly so as to reduce the damping force in the lower speed range, thereby considerably improving the driving comport of a vehicle.