Aircraft Turbine Engine Duct Molding Tool With Removable Release Key
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tools for molding composite material ducts for aircraft turbine engines are bulky, heavy, and thermally inhomogeneous, leading to poor polymerization, mechanical defects, and aerodynamic issues, requiring multiple molds and complicating demolding.
Innovation Solution
A tool comprising a basement and a body with removable parts, allowing fiber laps to be draped over a rigid structure, eliminating the need for an external mold, ensuring thermal homogeneity, and enabling simultaneous production of multiple ducts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a steel external mold with integrated heating system is used, then the mold provides structural support and heating capability, but the mold becomes very large and heavy, making it difficult to handle
Solution Approach 1:
The heating system is extracted from the mold structure itself and replaced by an external heating source (autoclave). The mold is reduced to only its essential forming function, eliminating the heavy integrated heating rods while maintaining the heating capability through the autoclave environment.
Solution Approach 2:
The autoclave serves as a universal heating device that can heat multiple molds simultaneously. Instead of each mold having its own dedicated heating system, the autoclave provides a shared heating environment that benefits all molds, reducing overall system weight and complexity.
2Temperature
If a steel external mold is used, then the mold provides structural support, but the thermal inertia of steel causes inhomogeneous temperature distribution in the resin during heating and polymerization
Solution Approach 1:
The heating function is extracted from the heavy steel mold structure and transferred to an external autoclave heating system. This eliminates the thermal inertia problems of steel while maintaining the mold's structural support function, allowing homogeneous heat distribution through the resin without the interfering thermal mass of a steel mold.
3Shape
If a flexible membrane is used as the molding surface, then the membrane can conform to the preform, but it lacks sufficient rigidity to ensure controlled roughness and absence of surface undulations
Solution Approach 1:
The patent uses a flexible membrane that is tensioned over a rigid internal structure (armature). The membrane provides the necessary flexibility to conform to the preform while the internal armature provides the rigidity needed to control surface roughness and prevent undulations, combining the advantages of both flexible and rigid structures.
4Strength
If the dry fibrous preform is relatively thick before compaction, then the preform can accommodate the fiber reinforcement, but it makes it difficult to close the various portions of the external mold and leads to local pinching of fibers
Solution Approach 1:
The mold is divided into multiple separable portions that can be opened and closed independently. This segmentation allows the thick preform to be accommodated during assembly while enabling progressive closure without excessive force that would cause fiber pinching. The portions can be staged to close in a controlled sequence.
Solution Approach 2:
The tool portions are designed to nest together with precise interlocking features. The sequential nesting of mold portions allows them to close over the thick preform in a controlled manner, with each portion guiding the next, preventing misalignment and localized pinching of fibers during the closing process.
5Ease of operation
If the flexible membrane does not apply sufficient pressure uniformly, then the preform can be easily positioned, but pockets of resin without fiber reinforcement are created, reducing mechanical characteristics
Solution Approach 1:
A vacuum bag is introduced as an intermediary between the operator and the preform for applying pressure. The vacuum bag distributes the vacuum pressure uniformly across the entire preform surface, ensuring consistent compaction and eliminating resin pockets while maintaining ease of operation through simple vacuum connection.
6Adaptability or versatility
If multiple molds are used to produce different duct references, then each duct reference can be manufactured, but the number of molds increases, increasing handling complexity and costs
Solution Approach 1:
The mold portions are designed as universal, interchangeable components that can be reconfigured to produce different duct references. The same basic mold portions can be assembled in different configurations or with different internal features to accommodate various duct geometries, eliminating the need for completely separate molds for each duct type.
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
Facilitates easier handling, improves thermal homogeneity, reduces mechanical defects, and enhances aerodynamic quality, while allowing multiple ducts to be produced simultaneously, thus reducing costs and handling complexity.
Implementation Method 1
The tool thus comprises a heating system integrated into the parts of the mold, in particular heating rods, i.e. resistors arranged in different places in the different portions of the mold
Implementation Method 2
The resin is injected into the preform using an injection piston, with a vacuum maintained at the level of the preform
Implementation Method 3
the tool continues to heat up to polymerize the resin
Data Source
AI summary
A tool is configured for molding a duct for an aircraft turbine engine, wherein the duct is made of a fiber-based composite material and includes a curved tubular portion, one end of which is connected to a peripheral flange. The tool has a base and a generally elongate and curved body. The body is formed by an assembly of first parts which are fitted tightly together and which include a first central release key which extends from one end of the body to the other and which is configured to be removed first upon release of the body.