Overmolded Diaphragm Holder Structure for Lightweight Compression Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional diaphragm holders for oleo-pneumatic shock absorbers, particularly in aircraft landing gear, face challenges in achieving optimal mechanical resistance and reduced mass due to limitations in material thickness and manufacturing methods, which affect their structural design and cost.
Innovation Solution
A manufacturing method involving overmolding a thermoplastic polymer onto an insert, allowing for complex geometries and stiffeners, combining the mechanical properties of both materials to enhance resistance to buckling and compression, with the option of using metallic inserts for improved compression strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional metal machining is used to manufacture diaphragm holders, then mechanical strength and structural integrity are ensured, but manufacturing time increases and cost rises
Solution Approach 1:
The patent replaces traditional mechanical machining processes with injection molding technology to manufacture diaphragm holders. This substitution transforms the manufacturing method from subtractive (machining) to additive (molding), significantly reducing production time while maintaining structural integrity through optimized design and material selection.
Solution Approach 2:
The patent changes the manufacturing parameters by adopting injection molding with specific process controls to achieve the required mechanical properties. By adjusting molding parameters, material temperature, pressure, and cooling rates, the process produces parts with adequate strength without requiring post-processing machining operations.
2Weight of moving object
If material thickness is reduced to decrease mass, then weight decreases, but minimum thickness limits from traditional machining constrain the design
Solution Approach 1:
The patent changes the manufacturing method to injection molding, which removes the minimum thickness constraints inherent in traditional machining. This parameter change enables the production of diaphragm holders with optimized, reduced wall thicknesses that minimize mass while maintaining structural adequacy through the molding process's ability to produce thin-walled components with consistent thickness.
Solution Approach 2:
The patent applies local quality optimization by varying wall thickness in different regions of the diaphragm holder based on structural requirements. Critical areas maintain sufficient thickness for strength, while non-critical areas use minimal thickness to reduce overall mass, achieving an optimized weight-strength balance enabled by the molding process.
3Weight of moving object
If thermoplastic polymer with short fibers is used to reduce mass, then buckling resistance improves, but compression breaking resistance may be insufficient
Solution Approach 1:
The patent employs composite materials by combining thermoplastic polymer matrix with short reinforcing fibers. This composite structure provides improved buckling resistance while maintaining reduced mass. The fiber reinforcement compensates for the lower compression strength of the polymer base material, achieving a balance between weight reduction and mechanical performance.
4Productivity
If injection molding is used to manufacture diaphragm holders, then manufacturing time decreases, but dimensional constraints on wall thickness complicate structural design
Solution Approach 1:
The patent changes the manufacturing approach to injection molding, which inherently handles thin-walled structures more effectively than machining. This parameter change simplifies structural design by allowing greater freedom in wall thickness optimization without the minimum thickness constraints of machining, reducing the complexity of meeting dimensional requirements.
Solution Approach 2:
The patent uses local quality variations in wall thickness and rib placement to simplify the overall structural design. By concentrating material where structurally necessary and using minimal material elsewhere, the design achieves required strength with simpler geometry that is more easily manufactured by injection molding.
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 method results in a diaphragm holder with improved mechanical resistance and reduced mass, enabling better performance under thermal and mechanical stresses while minimizing material thickness constraints.
Implementation Method 1
A manufacturing method involving overmolding a thermoplastic polymer onto an insert
Data Source
AI summary
A method for manufacturing a diaphragm holder for a shock absorber of the oleo-pneumatic type, in particular for an aircraft landing gear. The diaphragm holder includes a first end with a dome, and a tubular portion extending from the dome to a second end. The method includes a step of overmolding a first material onto an insert. The insert can be a second material with a value of compression breaking stress divided by density that is higher than the first material or alternatively, of a material identical to the first material. A diaphragm carrier which can be manufactured by this method.