Dual-Support Air Spring for Load-Responsive Stiffness
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Solution Overview
Problem
Existing air springs for rail vehicles face challenges in maintaining ride comfort under low-load conditions while preventing damage from subsidence under heavy-load conditions, as their stiffness increases smoothly with load, leading to significant deflection differences and potential damage.
Innovation Solution
The air spring design incorporates a second rubber metal spring connected in parallel with the first, featuring a height difference between supports that allows the top plate to contact either support when the diaphragm is out of air, transferring load to both springs under heavy conditions, increasing stiffness instantly and reducing deflection differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single rubber metal spring or series-connected springs are used, then the structure is simple, but the stiffness increases smoothly with load causing large deflection differences and potential damage under heavy-load conditions
Solution Approach 1:
The single rubber metal spring is segmented into two parallel springs with different stiffness characteristics. The first rubber metal spring has lower stiffness for low-load conditions, while the second rubber metal spring has higher stiffness for heavy-load conditions. This segmentation allows the system to provide different stiffness levels for different load conditions, resolving the contradiction between structural simplicity and stiffness control.
Solution Approach 2:
The system dynamically transitions between different stiffness states based on load conditions. Under low-load conditions, only the first spring is active providing low stiffness for comfort. When load increases, the top plate contacts the second support, activating the second spring and instantly increasing the overall stiffness. This dynamic adaptation resolves the contradiction by making stiffness a variable parameter rather than a fixed property.
2Ease of operation
If the rubber metal spring stiffness is designed for low-load comfort, then ride comfort is improved, but the spring cannot prevent damage under heavy-load conditions due to excessive deflection
Solution Approach 1:
The air spring system dynamically adjusts its stiffness characteristic based on the load condition. When the diaphragm is inflated, the system operates in normal mode with the first spring providing low stiffness for comfort. When the diaphragm deflates or under heavy load, the top plate contacts the second support, activating the second spring with higher stiffness to prevent excessive deflection and damage. This dynamic transition resolves the contradiction between comfort and reliability.
Solution Approach 2:
The second rubber metal spring and second support are pre-positioned to provide additional stiffness support before damage can occur. The height difference Δh is carefully designed so that the second spring becomes active at a specific load threshold, providing beforehand cushioning against excessive deflection and potential damage to the vehicle body and other components.
3Reliability
If the rubber metal spring stiffness is increased to prevent damage, then reliability is improved, but ride comfort deteriorates under low-load conditions due to excessive stiffness
Solution Approach 1:
The support structure is segmented into two supports at different heights, with the first support positioned for low-load comfort and the second support positioned for heavy-load protection. This segmentation allows the system to provide appropriate stiffness for each load condition, resolving the contradiction between reliability and comfort by making the effective stiffness dependent on the active support.
4Strength
If a height difference Δh is introduced between supports, then the air spring can instantly increase stiffness under heavy-load conditions, but the device complexity increases
Solution Approach 1:
The second rubber metal spring is nested within the cavity of the first rubber metal spring, and the supports are arranged concentrically. This nested arrangement allows the system to provide two different stiffness levels using a compact structure, resolving the contradiction between stiffness response and device complexity by utilizing vertical space efficiently.
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 design ensures ride comfort under low-load conditions and prevents damage by instantly increasing stiffness when transitioning to heavy-load conditions, significantly reducing deflection differences and enhancing safety.
Implementation Method 1
the rubber metal spring plays an auxiliary role of reducing vibration
Implementation Method 2
the diaphragm plays a main role of reducing vibration
Data Source
Figure 1~2
Figure 3~4
AI summary
An air spring provided by the present application comprises a top plate, a diaphragm, a first rubber metal spring and a second rubber metal spring; the diaphragm is arranged between the top plate and the first rubber metal spring; the first rubber metal spring is hollow to form a cavity, and the cavity of the first rubber metal spring penetrates through a top of the first rubber metal spring in a vertical direction, and the top of the first rubber metal spring is connected to a first support, and a top of the first support corresponds to the top plate to come into contact with the top plate when the diaphragm is out of air; the second rubber metal spring is fixedly inserted in the cavity of the first rubber metal spring; a top of the second rubber metal spring is connected to a second support, and a top of the second support corresponds to the top plate to come into contact with the top plate when the diaphragm is out of air; and, when the diaphragm is inflated, there is a height difference Δh between the top of the second support and the top of the first support, where the Δh≠0. The air spring provided by the present application can ensure ride comfort of the vehicle under a low-load condition and avoid damage to other components resulted from a subsidence of a vehicle body under a heavy-load condition.