Pyrotechnic Chain Ignition Timing for Missile Propulsion
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Solution Overview
Problem
Existing pyrotechnic ignition systems for missiles lack reliability in ensuring safe ignition of the main propellant charge after ejection, particularly due to dependence on microbead flow which can be inconsistent, leading to potential failure in achieving the required acceleration and distance criteria.
Innovation Solution
A pyrotechnic chain with an arming device that transitions to an 'armed' mode through a pyrotechnic arming delay and trajectory delay, utilizing a squib and relay charges to ensure reliable ignition of the main load, independent of microbead flow, with a movable part and locking mechanisms to secure the arming device in the active position, and a screen-eliminating bed of microbeads for safety and damping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a bed of microbeads is used to prevent ignition when acceleration criteria are not met, then safety is improved, but reliability deteriorates because microbead flow behavior is inconsistent and difficult to control over time
Solution Approach 1:
The invention extracts the delay function from the microbead safety device and places it in a dedicated pyrotechnic delay device. This separation allows the microbeads to focus solely on their safety function (blocking ignition path) while the pyrotechnic delay device reliably controls timing, eliminating the inconsistency caused by trying to perform both functions simultaneously.
Solution Approach 2:
The invention segments the ignition system into distinct functional components: a pyrotechnic arming delay device for timing control, a pyrotechnic trajectory delay device for additional timing, and a microbead safety device for safety blocking. This segmentation allows each component to be optimized for its specific function, improving overall system reliability.
2Device complexity
If microbeads are used to define delay duration, then device complexity is reduced, but manufacturing precision deteriorates because microbead flow characteristics are difficult to control and characterize
Solution Approach 1:
The invention replaces the mechanical microbead flow delay mechanism with a pyrotechnic composition-based delay device. Pyrotechnic compositions have well-established, controllable burn rates that can be precisely manufactured and characterized, providing consistent delay timing without the variability inherent in microbead flow systems.
3Object-affected harmful factors
If the arming device is locked in rest position by a locking member, then safety is improved, but device complexity increases due to additional locking mechanisms
Solution Approach 1:
The invention uses a squib that is pre-positioned to break the locking member's retention element upon activation. This preliminary arrangement ensures that when the squib fires, the locking member is immediately released, allowing the arming device to transition to the active position without requiring complex active release mechanisms.
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 enhances long-term reliability by controlling and characterizing the pyrotechnic composition's behavior, ensuring consistent and safe ignition of the main propellant charge, independent of initial acceleration and distance, thereby improving the safety and effectiveness of missile propulsion systems.
Implementation Method 1
a squib arranged to be ignited on ejection of the missile and cause the ignition of the arming and release of the first locking member
Implementation Method 2
a pyrotechnic arming delay, a squib arranged to be ignited on ejection of the missile and cause the ignition of the arming and release of the first locking member
Implementation Method 3
The microbead safety device comprises a bed of microbeads which flow through openings cleared by the arming device coming into the 'armed' state. or returning to an 'unarmed' state
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The firing chain of the invention includes an arming device (40) mobile between a rest and an active position., two locking members (14, 16) for locking the arming device in a rest position and an active position, an arming pyrotechnical retarder (22), a squib (26) ignited at the ejection of the missile and igniting the arming retarder and releasing the first locking member (14) in order to allow the arming device to be switched into an active position, and a trajectory pyrotechnical retarder (32). A first relay charge (29) is adapted to be ignited at the end of the combustion of the arming retarder and to trigger the ignition of the trajectory retarder and the actuation of the second locking member (16) for locking the arming device in an active position and a second relay charge (34) is adapted to be ignited at the end of the combustion of the trajectory retarder and to trigger the ignition of the main charge.