Check Valve Coil Spring Stop Absorbs Impact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing check valves in aircraft applications face challenges due to the high impact forces on flapper elements, which can lead to overstressing and potential failure, requiring robust and heavy flapper elements to withstand these forces.
Innovation Solution
A check valve design incorporating a coil spring stop mounted between mounting posts, allowing flapper elements to engage the spring in a medial region, with variable or constant diameter configurations, and featuring rotatable end sections to absorb impact energy and reduce stress on the mounting posts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If robust flapper elements are used to withstand impact forces, then reliability is improved, but weight increases
Solution Approach 1:
A coil spring stop is introduced as an intermediary component between the flapper element and the mounting posts. The spring absorbs impact energy during flapper opening, reducing the peak forces transmitted to the flapper elements. This mediator allows the use of lighter flapper elements while maintaining reliability by protecting them from damaging impact loads.
Solution Approach 2:
The coil spring is pre-installed in a compressed state between the mounting posts, creating a cushioning mechanism before impact occurs. When the flapper elements open, the spring further compresses to absorb the impact energy, preventing sudden shock loads that would require heavier, more robust flapper elements.
2Strength
If heavy flapper elements are used to withstand impact forces, then strength is improved, but weight increases
Solution Approach 1:
The coil spring acts as a force-distributing intermediary that converts impulsive impact loads into gradual compression forces. This reduces the peak stress on flapper elements, allowing them to be designed with lower strength margins and consequently reduced weight while maintaining adequate strength.
Solution Approach 2:
The spring's mechanical properties (coil rate, wire diameter, number of turns) are optimized to provide appropriate force characteristics. By adjusting these parameters, the impact forces are controlled to remain within acceptable limits for lighter flapper element designs, achieving the desired strength protection without excessive weight.
3Manufacturing precision
If a rigid stop is used to limit flapper rotation, then positioning precision is improved, but impact forces increase
Solution Approach 1:
The rigid stop is replaced with a flexible coil spring that can deflect under load. This flexible stop still effectively limits the rotation of flapper elements to the desired position while absorbing impact energy through elastic deformation, thereby reducing the peak forces compared to a completely rigid stop.
Solution Approach 2:
The stop mechanism transitions from a static rigid structure to a dynamic spring-based system that adapts to impact forces. The spring's ability to compress and rebound provides continuous force adjustment during the impact event, maintaining positioning control while modulating the force transmission to protect the flapper elements.
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 coil spring stop effectively dissipates impact energy, reducing the risk of flapper element failure and allowing for lighter construction, enhancing reliability and safety in aircraft applications.
Implementation Method 1
The stop is a coil spring. The flapper elements and the coil spring may be configured such that the flapper elements engage the stop in a medial region of the coil spring
Implementation Method 2
The coil spring stop effectively dissipates impact energy, reducing the risk of flapper element failure
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A check valve (2) comprises a valve housing (4) defining a valve opening (6), a pair of mounting posts (10) arranged on opposed sides of the valve opening (6) and a hinge pin (12) mounted between the mounting posts (10). A pair of flapper elements (14) are pivotably mounted to the hinge pin (12) for rotation relative to the housing (4) between an open position in which they permit fluid flow through the valve opening (6) and a closed position in which they prevent fluid flow through the valve opening (6) (6). The valve further comprises a stop (24) mounted between the mounting posts (10) above the hinge pin (12) and extending across the valve opening (6) such that the flapper elements (14) will contact the stop (24) in their open positions. The stop (24) is a coil spring.