Magnetorheological Piston Valve for Damping During Power Failure
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Solution Overview
Problem
Conventional magnetorheological (MR) piston dampers experience a loss of damping effect when power is disrupted, leading to reduced vehicle maneuverability at high speeds due to the loss of viscosity in the MR fluid, necessitating either speed limiting or compromising ride isolation to maintain handling.
Innovation Solution
Incorporating an electromagnetic valve with a spring-loaded restrictor plate that is magnetically attracted to partially restrict the MR passageway when power is disrupted, ensuring firm damping is maintained by transitioning between states based on electrical activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional MR dampers are used without additional valve mechanisms, then the device complexity is low, but the reliability deteriorates during power disruptions due to loss of damping effect
Solution Approach 1:
The electromagnetic valve is integrated into the piston assembly, merging the valve function with the existing piston structure. The valve coil is positioned on the piston, and the restrictor plate is incorporated into the piston's MR passageway system, creating a unified component that maintains damping during power disruptions without requiring separate external valve mechanisms.
Solution Approach 2:
The spring-loaded restrictor plate is pre-positioned to automatically restrict the MR passageway when power is disrupted. The spring is pre-compressed to exert force on the restrictor plate, so that upon power loss, the plate immediately moves to the restricted position without requiring active control input, ensuring continuous damping effect.
2Reliability
If the electromagnetic valve restricts the MR passageway when not activated, then firm damping is maintained during power disruptions, but the device complexity increases due to additional valve components
Solution Approach 1:
The electromagnetic valve operates autonomously based on the presence or absence of electrical power. The spring-loaded restrictor plate automatically responds to power status changes without requiring external control signals or complex valve mechanisms. When power is present, the electromagnetic coil holds the plate in an open position; when power is lost, the spring automatically restricts the passageway, making the system self-regulating.
Solution Approach 2:
The complex control system is extracted from the valve mechanism itself and replaced with a simple electromagnetic coil and spring arrangement. The control function is separated from the mechanical valve components, allowing the valve to respond passively to electrical power status rather than requiring active control electronics or complex actuation mechanisms.
3Reliability
If the restrictor plate completely restricts the MR passageway when not activated, then firm damping is ensured during power failures, but the fluid flow is excessively restricted affecting normal operation
Solution Approach 1:
The restrictor plate is designed to partially restrict the MR passageway rather than completely blocking it. When in the restricted position, the plate narrows the passageway to increase damping effect, but maintains sufficient opening for fluid flow. This partial restriction achieves the desired firm damping during power failures while preventing excessive flow restriction that would impair normal damper 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
This solution provides consistent and enhanced vehicle maneuverability at high speeds by maintaining firm damping during power disruptions, unlike conventional MR dampers which rely on speed limiting or ride isolation compromises.
Implementation Method 1
The electromagnetic valve has an electromagnetic-valve coil and a spring-loaded restrictor plate. The electromagnetic valve has a first state which magnetically attracts the spring-loaded restrictor plate toward the electromagnetic-valve coil when the electromagnetic-valve coil is electrically activated.
Implementation Method 2
Exposing the MR fluid in the MR passageway to a varying magnetic field, generated by providing a varying electric current from a controller to an electric coil of the MR piston, varies the damping effect of the MR fluid in the MR passageway
Data Source
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AI summary
A magnetorheological (MR) piston assembly (10) includes an MR piston (12) and a rod (14). The MR piston includes a central longitudinal axis (16), first and second longitudinal ends (18,20), an MR passageway (22), a main electric coil (24), and a valve (26). The MR passageway extends from the first longitudinal end to the second longitudinal end. The main electric coil is disposed to magnetically energize the MR passageway. The valve is operatively connected to the MR passageway. The valve has a first state when electrically activated which is less restrictive of the MR passageway and has a second state when not electrically activated which is more restrictive of the MR passageway. The rod is attached to the MR piston. A more detailed MR piston and an MR damper system are also described.