Piezoelectric Actuator for Variable Damping Control
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Solution Overview
Problem
Conventional fluid damper assemblies in vehicles face a compromise between stiff suspension for active performance and soft suspension for comfort, requiring disassembly for tuning adjustments and affecting noise and isolation.
Innovation Solution
A fluid damper assembly with an actuator connected to a retainer that compresses a spring to disengage the rebound disk, allowing it to flex solely in response to hydraulic fluid pressure, reducing damping force during the rebound stroke and enabling rapid adjustment between stiff and soft suspension settings without disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the suspension is made stiff with high damping force, then active performance and handling capability are improved, but noise and isolation performance deteriorate
Solution Approach 1:
The patent implements a variable damping force shock absorber that dynamically adjusts damping characteristics between stiff and soft settings. The system uses a controllable flow restriction device to modify fluid flow resistance in real-time, allowing the suspension to transition from a stiff state (improving handling) to a soft state (improving isolation), thereby resolving the contradiction between these opposing performance requirements
Solution Approach 2:
The invention changes the physical parameter of damping force by adjusting the flow restriction magnitude. By modifying the flow restriction device's opening area or resistance, the system varies the damping force parameter to match different driving conditions, enabling optimal balance between active performance and comfort/isolation performance
2Object-affected harmful factors
If the suspension is made soft with low damping force, then comfort and isolation are improved, but active handling capability deteriorates
Solution Approach 1:
The variable damping force shock absorber enables dynamic switching between soft and stiff damping characteristics. When isolation and comfort are prioritized, the system adopts soft damping settings. When active handling is required, it transitions to stiff settings, thus resolving the contradiction between comfort and handling capability through real-time adaptability
3Adaptability or versatility
If the damper tuning is changed from stiff to soft suspension setting, then suspension softness is improved, but disassembly and modification of the fluid damper assembly are required
Solution Approach 1:
The patent incorporates a controllable flow restriction device that can be adjusted without disassembling the damper assembly. This device allows tuning between stiff and soft suspension settings by simply modifying the flow restriction parameter, eliminating the need for complex disassembly and reconfiguration operations while maintaining full adaptability of suspension characteristics
Solution Approach 2:
The invention replaces the traditional mechanical adjustment mechanism (requiring disassembly of disks and passages) with a controllable flow restriction device that can be adjusted through simpler means. This substitution reduces the complexity of tuning operations while preserving the ability to change suspension characteristics
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 real-time controllability of the damper assembly, improving ride and handling performance by eliminating the compromise between handling and isolation, and reducing complexity and size, while minimizing cost.
Implementation Method 1
a spring biases the retainer toward the rebound disk
Implementation Method 2
the rebound disk to flax solely in response to hydraulic fluid pressure from the rebound stroke
Implementation Method 3
an actuator connected to the retainer for moving said retainer axially to compress the spring along the center axis for disengaging the retainer from the rebound disk
Data Source
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AI summary
A fluid damper assembly for use in a vehicle includes a piston subassembly which includes a plurality of inflow passages and at least one rebound disk for restricting flow of hydraulic fluid through the inflow passages. A rod extends through the piston subassembly to actuate the piston subassembly between a rebound stroke and a compression stroke. An actuator supported by and within the rod includes a piezoelectric device and an amplifier for adjusting the damping force during the rebound stroke, thereby adjusting the suspension of the vehicle. A shaft within the rod is connected to a retainer to transmit motion from the amplifier to compress a spring and disengage the retainer from the rebound disk to allow the rebound disk to flex solely in response to hydraulic fluid pressure from the rebound stroke to open the inflow passages and reduce the damping force during the rebound stroke.