Dual-State Hydromount Air Spring Stiffness Control
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Solution Overview
Problem
Hydraulic engine mounts face challenges in maintaining adequate damping during ride mode due to the decoupled state, which reduces secondary ride quality and increases noise, vibration, and harshness (NVH), and existing solutions require active control to manage air springs, increasing complexity and cost.
Innovation Solution
A dual-state hydraulic mount system that passively traps air underneath the decoupler using a vacuum-actuated valve and one-way check valve, switching between idle and ride modes based on vehicle speed, to adjust the stiffness of the decoupler without active control, thereby maintaining damping and reducing NVH.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the decoupler is allowed to move freely in ride mode, then the mount provides good vibration isolation, but damping is reduced and NVH increases
Solution Approach 1:
The patent changes the physical state of the fluid in the vacuum chamber from liquid to gas (air spring) to alter the stiffness characteristics of the decoupler. This parameter change enables the system to provide both vibration isolation and maintain damping by creating a compressible air spring that allows controlled movement while maintaining restoring force
Solution Approach 2:
The system dynamically adjusts the stiffness of the decoupler by switching between liquid-filled and air-spring states based on operating conditions. The vacuum chamber transitions from containing liquid to containing air, creating a dynamically adjustable suspension system that adapts to different ride modes
2Object-generated harmful factors
If a solenoid actuated valve is used to trap air in the control cavity, then the air spring resists decoupler movement and increases damping, but the cost and complexity of the mount increases
Solution Approach 1:
The system uses the engine's existing vacuum system to automatically control the vacuum actuated valve, eliminating the need for external solenoid actuators or electronic control systems. The vacuum pressure from the engine intake manifold self-regulates the air spring formation, reducing complexity while maintaining damping control
Solution Approach 2:
The patent replaces complex solenoid actuated valves with simpler vacuum actuated valves that use pneumatic pressure from the engine's vacuum system. This substitution eliminates electrical components and complex control mechanisms, reducing cost and complexity while achieving the same functional result
3Object-generated harmful factors
If a vacuum actuated valve is used to trap air in the cavity, then the air spring is created to increase damping, but active control is still required
Solution Approach 1:
The vacuum actuated valve is controlled automatically by the engine's vacuum system, which provides vacuum pressure when the engine is running. This eliminates the need for active electronic control or additional actuators, as the system self-regulates based on engine operating conditions
Solution Approach 2:
The engine's vacuum system, originally designed for other purposes, is utilized to control the air spring mechanism. This multi-functional use of the vacuum system eliminates the need for dedicated control mechanisms, reducing complexity and achieving passive 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
The system effectively mitigates the reduction in damping during ride mode, enhancing secondary ride quality and reducing NVH by passively introducing an air spring under the decoupler, eliminating the need for active control and simplifying the mount's operation.
Implementation Method 1
evacuating a vacuum chamber housed within a partitioning structure of a hydraulic engine mount
Implementation Method 2
directing the flow of air through a first air passage to a second air passage via a one way check valve
Data Source
AI summary
Methods and systems are provided for a dual state hydromount in order to passively introduce air underneath a decoupler such that the stiffness of the air pocket adds to the stiffness of the decoupler, thereby increasing a level of damping available in a vehicle ride mode, the ride mode defined by vehicle speeds greater than a threshold speed. In one example, a dual state hydromount is described wherein a partitioning structure may be alternately coupled to either vacuum or atmosphere, and when coupled to atmosphere an air spring is created under the decoupler via the passive directing of air to the decoupler via a one way check valve. In this way, introduction of an air spring is achieved without additional active control.