Ramjet Missile Shearable Locking Mechanism
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Solution Overview
Problem
The existing ramjet engine locking mechanisms for missile propulsion are complex, prone to failure, and require precise manufacturing, leading to high costs and reliability issues, with a risk of accidental cap opening and reduced air inlet openings due to complex pyrotechnic systems and large space requirements.
Innovation Solution
A shearable locking mechanism that locks the closure cap during the first propulsion phase and automatically opens with a defined shearing force after the starting propellant burns out, eliminating the need for additional unlocking devices and allowing for a more reliable and compact design with increased air inlet openings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a complex pyrotechnic unlocking mechanism with actuating bolts and transmission linkage is used, then the cap can be opened after the first drive phase, but the device complexity increases and the risk of failure increases
Solution Approach 1:
The patent extracts and eliminates the complex pyrotechnic unlocking mechanism, actuating bolts, transmission linkage, and precision guides from the system. Instead, it uses a simple shearable lock integrated into the closure cap that automatically opens when the propellant burns out and pressure drops, removing unnecessary components while maintaining the required functionality.
Solution Approach 2:
The closure cap with shearable lock is designed to automatically open itself when the starting propellant burns out and internal pressure decreases. The shearable lock breaks at a predetermined force threshold without requiring external actuation, making the system self-operating and eliminating the need for complex unlocking mechanisms.
2Reliability
If precision guides and additional components for unlocking are added, then the cap can be opened reliably, but the manufacturing precision requirements increase and manufacturing costs increase
Solution Approach 1:
The patent removes precision guides and complex unlocking components from the design. The shearable lock is integrated directly into the closure cap structure, eliminating the need for separate precision-guided actuating mechanisms and reducing manufacturing precision requirements while maintaining reliable operation.
Solution Approach 2:
The shearable lock is designed as a disposable component that breaks at a predetermined force threshold. This simple, low-cost component replaces expensive precision guides and complex unlocking mechanisms, providing reliable functionality without high manufacturing precision requirements.
3Ease of operation
If a pyrotechnic charge and transmission linkage are added for actuating the bolt, then the cap can be opened, but the device complexity increases and the weight increases
Solution Approach 1:
The patent extracts and eliminates the pyrotechnic charge, transmission linkage, and actuating bolt from the system. The closure cap opens automatically through the shearable lock mechanism that breaks when internal pressure drops after propellant combustion, requiring no additional actuating components.
Solution Approach 2:
The system uses the pressure differential created during propellant combustion to automatically open the closure cap. The shearable lock breaks at a predetermined force threshold without external actuation, making the opening operation self-service and eliminating complex actuating mechanisms.
4Reliability
If the latch projection and hole mechanism is used for locking, then the cap can be locked during the first drive phase, but the attachment may loosen and the projection may get stuck or snap back
Solution Approach 1:
The patent extracts the latch projection, hole, and bearing mechanism from the design. Instead, it uses a simple shearable lock integrated into the closure cap that provides reliable locking during the first drive phase and automatic opening when needed, eliminating the reliability issues of the latch mechanism.
Solution Approach 2:
The shearable lock is designed as a simple, disposable component that provides reliable locking during operation and then breaks at a predetermined force threshold. This eliminates the complexity and reliability issues of reusable latch mechanisms with moving parts that can loosen or get stuck.
5Reliability
If the bearing of the cap on the combustion chamber wall is used for locking, then the cap can be locked, but the attachment may loosen so that the projection exits the hole and the cap can accidentally jump open
Solution Approach 1:
The patent extracts the bearing attachment mechanism, latch projection, and hole from the design. The shearable lock is integrated directly into the closure cap structure, providing reliable locking without attachment points that can loosen, and eliminating the risk of accidental cap opening.
Solution Approach 2:
The shearable lock provides reliable, permanent locking during the first drive phase through its integrated design, then breaks at a predetermined force threshold to open the cap. This disposable approach eliminates the reliability issues of reusable attachment mechanisms that can loosen over time.
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 solution reduces manufacturing complexity and weight, ensures a secure and tight closure, and allows for a higher number of air inlet openings by using a shearing force to open the cap, which is determined by the material and cross-sectional area of the locking mechanism, providing a reliable and efficient propulsion system.
Implementation Method 1
a starting propellant burns in the combustion chamber of the ramjet engine in the first propulsion or starting phase. This creates high pressure inside the combustion chamber when the missile is launched in the first propulsion phase.
Implementation Method 2
the cap is locked in the first drive or starting phase by a lock that can be sheared off after the first drive or starting phase when the opening piston for opening the cap engages the cap to open the air inlet opening
Data Source
Figure 1~3
Figure 4~6
AI summary
The missile has ramjet engine, which has two drive phases. The ramjet engine has a combustion chamber with a start propellant (13) and air inlet opening (2). A bolting device (17) is provided, which is sheared by the force of an opening piston (15). The bolting device has a pull linkage. A sealing cover (4) is partly made of a fiber reinforced material, and is partly made of a ceramic material.