Adjustable Pyrotechnic Delay Device for Mortar Fuses
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Solution Overview
Problem
Pyrotechnic delay devices for ammunition fuses lack the ability to adjust delay times without replacing the delay element, limiting flexibility in applications such as mortar projectiles where varying delay times are required.
Innovation Solution
A pyrotechnic delay device with a bypass element and rotating housings allows for adjustable delay times by aligning radial bores filled with a high-burning-rate pyrotechnic transfer charge, enabling multiple delay times within a single delay line without replacing the delay element, and utilizing detachable latching connections for precise adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a pyrotechnic delay device uses a fixed delay element, then the device structure is simple, but the delay time cannot be adjusted without replacing the delay element
Solution Approach 1:
The delay element is segmented into multiple sections with different burning rates, and a bypass element with a significantly higher burning rate is introduced. By selectively activating different sections or the bypass element, multiple delay times can be achieved without replacing the entire delay element, thus providing adjustability while maintaining a relatively simple structure.
Solution Approach 2:
The delay device incorporates a rotating housing mechanism that allows the user to dynamically adjust the alignment between radial bores of the delay element and bypass element. This dynamic adjustment enables selection of different delay times by rotating the housing to different angular positions, transforming a static fixed-delay device into an adjustable one.
2Adaptability or versatility
If multiple delay elements are used to achieve different delay times, then the desired delay times can be achieved, but the device complexity and number of parts increase
Solution Approach 1:
A single delay element is designed to serve multiple functions by incorporating sections with different burning rates and a bypass element. This universal delay element can provide multiple delay time settings (e.g., short, medium, long delay) without requiring separate delay elements for each setting, thus reducing the number of parts while maintaining versatility.
Solution Approach 2:
The bypass element is nested within or alongside the main delay element structure. The bypass element can be selectively activated to shorten the delay time by providing an alternative, faster burn path. This nested configuration allows multiple delay options to be integrated into a single compact structure rather than requiring separate external components.
3Duration of action of moving object
If a bypass element with high burning rate is introduced, then short delay times can be achieved, but the device structure becomes more complex
Solution Approach 1:
The bypass element is merged with the main delay element structure, sharing common components such as the housing, ignition system, and support structures. This combining approach allows the bypass element to provide extended delay time range functionality while minimizing additional structural complexity, as the bypass element integrates into the existing framework rather than requiring a completely separate system.
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
Enables flexible and precise adjustment of delay times within a single delay line, allowing for multiple settings without replacing the delay element, enhancing the functionality of mortar projectiles by autonomously acting payloads.
Implementation Method 1
a bypass element with a pyrotechnic transfer charge that has a significantly higher burning rate than the material of the pyrotechnic delay element
Implementation Method 2
a pyrotechnical delay element which is ignited when the ammunition is fired and which, after a predetermined delay time, ignites a main charge
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a pyrotechnic delay device for an ammunition fuse (1) with a pyrotechnic delay element (5) which is ignited when the ammunition is fired and which ignites a main charge (4), an expulsion charge or the like, after a specified delay time. The aim of the invention is to provide a pyrotechnic delay device (3) with an adjustable delay time. According to the invention, this is achieved in that in addition to the pyrotechnic delay element (5) with a strictly defined delay time, a bypass element with a transmission charge (15) is integrated into the delay device (3), said transmission charge having a substantially higher burn rate than the delay element (5). If the delay device (3) sets a delay time which is shorter than the delay time specified by the delay element (5), the bypass element is activated after a specifiable first section of the delay element (5) is burned so that the remaining second section of the delay element (5) is bridged by the bypass element, and the corresponding main charge (4) or the like is ignited immediately after the first section has burned.