Rocket Motor Ignition Safety Device Segmentation
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Solution Overview
Problem
Existing ignition safety devices for rocket motors face challenges in maintaining structural safety, size, weight, and shape due to the damage of electronic circuits by Low Energy Exploding Foil Initiators (LEEFIs) and the need for integral housing design to withstand combustion pressure, which limits their functionality and maintainability.
Innovation Solution
The design includes a separable ignition safety device with a high voltage initiator housed in a lightweight aluminum structure, featuring a reception space with an O-ring for fluid prevention and a separable initiation part that prevents fluid movement, allowing for independent module operation and easy replacement, thus reducing the risk of circuit damage and enabling post-ignition inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If an LEEFI is used for ignition in a rocket motor, then high-temperature and high-pressure combustion gases are generated, but the housing is destroyed and the propulsion system is immediately detonated
Solution Approach 1:
The device is divided into two separate modules: an ignition circuit part and an initiation part containing the LEEFI. This segmentation isolates the high-voltage initiator from the electronic circuits, allowing the LEEFI to detonate without destroying the housing or propagating combustion gases to the propulsion system.
Solution Approach 2:
A partition wall with a through-hole is introduced as an intermediary structure. The through-hole is selectively openable to allow ignition energy transmission when needed, while the partition wall itself acts as a barrier to prevent combustion gas propagation, mediating between the initiator and the propulsion system.
2Reliability
If the housing is designed to withstand LEEFI detonation, then structural safety is improved, but the device size and weight increase
Solution Approach 1:
By segmenting the device into separate modules, the housing of the ignition circuit part does not need to withstand full detonation forces. Only the initiation part housing needs to contain the LEEFI, allowing for a lighter overall structure while maintaining structural safety.
Solution Approach 2:
The high-voltage LEEFI is extracted from the main housing and placed in a separate initiation part. This extraction removes the need for the main housing to be designed for detonation resistance, enabling weight reduction while maintaining safety.
3Device complexity
If the ignition circuit and initiation part are integrated, then device complexity is reduced, but circuit damage occurs during ignition
Solution Approach 1:
The device is segmented into an ignition circuit part and an initiation part, physically separating the electronic circuits from the high-voltage LEEFI. This separation prevents circuit damage during ignition while maintaining manageable device complexity through modular design.
Solution Approach 2:
A partition wall with a controllable through-hole acts as an intermediary between the ignition circuit and the LEEFI. This intermediary structure allows electrical connection when needed while providing physical protection against ignition damage to the circuits.
4Reliability
If a Through Bulkhead Initiator is used to confine combustion gases, then air tightness is maintained, but the propulsion system cannot be immediately detonated
Solution Approach 1:
The partition wall structure incorporates a selectively openable through-hole that can be opened or closed based on operational requirements. This dynamic configuration allows the system to switch between air-tight confinement and open ignition pathways, resolving the contradiction between maintaining air tightness and enabling immediate detonation.
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 structural safety, reduces size and weight, and allows for repeated use of the initiation part, improving maintenance and reducing development and testing costs by preventing circuit damage and enabling precise feedback during rocket operations.
Implementation Method 1
an O-ring disposed at an inner surface of the housing constituting the reception space and an inner surface of the high voltage initiator to prevent fluid movement
Implementation Method 2
When the initiation signal is applied, the high voltage charged in the capacitor is applied to a Low Energy Exploding Foil Initiator (LEEFI) to be ignited
Implementation Method 3
high-temperature and high-pressure gas, i.e., ignition energy, is discharged to the outside of an ignition safety device
Implementation Method 4
the housing and the main body are coupled by welding
Data Source
AI summary
Provided is an ignition safety device for a rocket motor. The device includes an ignition circuit part including a main body and a control unit configured to generate an initiation signal on the basis of a specific signal, and an initiation part mounted at one end of the ignition circuit part and including at least one high voltage initiator electrically connected to the ignition circuit part. The initiation part includes a housing having at least one reception space for receiving the at least one high voltage initiator, and the housing and the main body are coupled by welding.