Vehicle Active Damper Using Magnetorheological Elastomer
Solution Overview
Problem
Existing vehicle vibration absorbing devices are limited in their ability to absorb vibrations across a wide frequency band due to fixed natural vibration frequencies and changes in elastic modulus with temperature, leading to inadequate damping effects.
Innovation Solution
A vehicle active damper system using elastic modulus-variable members, such as magnetorheological elastomers, that adjust their modulus based on magnetic field strength, coupled with a second elastic member to transmit engine vibrations vertically, allowing for active suppression of vibrations across a broader frequency range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed elastic modulus member is used between the radiator and vehicle body, then the structure is simple, but the natural vibration frequency is fixed and cannot absorb vibrations outside the target frequency band
Solution Approach 1:
The patent applies the dynamics principle by using a magnetorheological elastomer whose elastic modulus can be dynamically changed in response to temperature variations. The elastic member transitions from a static component to a dynamic one that automatically adjusts its properties based on thermal conditions, enabling the natural vibration frequency to track the target frequency band across different operating temperatures.
Solution Approach 2:
The patent implements parameter changes by utilizing the temperature-dependent elastic modulus characteristics of magnetorheological elastomers. As temperature changes, the elastic modulus of the member changes accordingly, which in turn adjusts the natural vibration frequency of the damper system to maintain effectiveness across a wide frequency band without requiring complex active control mechanisms.
2Reliability
If the elastic modulus of the elastic body is high to provide sufficient damping, then the damping effect is improved, but the natural vibration frequency shifts when heat is radiated from the radiator
Solution Approach 1:
The patent exploits the temperature-dependent parameter changes of magnetorheological elastomers to maintain consistent damping performance. The elastic modulus naturally varies with temperature in a way that compensates for frequency shifts, ensuring the natural vibration frequency remains aligned with the target frequency band across different thermal conditions.
Solution Approach 2:
The magnetorheological elastomer provides self-service by automatically adjusting its elastic modulus in response to temperature changes without requiring external control systems. The material's inherent thermally-responsive properties enable the damper to maintain optimal damping characteristics across varying operating conditions.
3Adaptability or versatility
If a dynamic damper with fixed natural vibration frequency is used, then the device complexity is low, but it cannot absorb vibration components outside the fixed frequency values
Solution Approach 1:
The patent achieves wide frequency band coverage through parameter changes in the elastic member's material properties. The magnetorheological elastomer's elastic modulus varies with temperature, which dynamically adjusts the natural vibration frequency of the damper to track the engine's vibration frequency across different operating conditions, eliminating the need for multiple fixed-frequency dampers.
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 system effectively attenuates vibrations across a wide frequency band by dynamically adjusting the apparent mass and phase of the damper waves, providing improved damping performance and reducing vibration transmission to the vehicle cabin.
Implementation Method 1
The first elastic member is formed from a magnetorheological elastomer whose elastic modulus varies in accordance with the strength of a magnetic field applied thereto.
Implementation Method 2
the apparent mass of the radiator (the inertial mass) (and hence the natural vibration frequency of the active dynamic damper) can be appropriately adjusted by control so as to apply a desired magnetic field to the first elastic member (the variable elastic modulus member) and vary the elastic modulus thereof.
Data Source
AI summary
A vehicle active damper includes a damping actuator that is provided between a radiator and a vehicle body so as to be interposed in a substantially vertical direction, and a coupling member that elastically couples between the vehicle body and an engine. The damping actuator is formed from a elastic modulus-variable member having an elastic modulus that varies according to the strength of an applied magnetic field. The coupling member transmits vibrations of the engine to the vehicle body along a substantially vertical direction.