Stainless Steel Igniter Feedthrough for Low-Failure Pin Sealing
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Solution Overview
Problem
Existing metal fixing material feedthroughs for devices like airbag igniters and belt tensioners face challenges in efficient series production and assembly due to material waste, off-center through openings, and the tendency of nickel-iron pins to bend or break during processing, leading to high reject rates.
Innovation Solution
The use of stainless steel pins with specific dimensions and properties, such as a core area of stainless steel according to EN 10020:2000, which are annealed to enhance mechanical stability and resist deformation, allowing for efficient production and assembly with reduced bending and increased pull-out force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nickel-iron pins are used in metal fixing material feedthroughs, then the thermal expansion coefficient ratio requirement is met, but the pins bend or break during processing leading to high reject rates
Solution Approach 1:
The patent changes the material parameter from nickel-iron alloy to stainless steel, which fundamentally alters the mechanical properties including higher strength and better resistance to bending and breaking during processing, while maintaining compatibility with the glass-ceramic fixing material
Solution Approach 2:
The patent employs a composite structure where the stainless steel pin is embedded in glass-ceramic fixing material within a metal base body, creating a multi-material system that combines the advantages of each material: stainless steel provides mechanical strength and resistance to deformation, while glass-ceramic provides thermal insulation and electrical isolation
2Ease of manufacture
If through openings are punched out of the base body, then the base body can be manufactured from strip material, but material waste is produced
Solution Approach 1:
The patent changes the manufacturing parameter from punching out openings to laser drilling or wire cutting, which allows for more precise material removal with minimal waste and the ability to create optimized opening patterns that reduce material loss while maintaining manufacturing efficiency
3Ease of operation
If the through opening is arranged off-center, then assembly can be facilitated, but manufacturing precision is compromised
Solution Approach 1:
The patent changes the positioning parameter from off-center to centrally arranged through openings, which can be more accurately positioned using laser drilling or wire cutting technologies, thereby maintaining both manufacturing precision and assembly ease through the use of advanced manufacturing methods
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
The stainless steel pins provide higher mechanical stability, reduced deformation during assembly, and increased pull-out forces, leading to lower reject rates and improved reliability in series production and post-processing.
Implementation Method 1
The metal pins (5, 6) are annealed, in particular the metal pin (5) which is encased in glass (10)
Implementation Method 2
the metal pin (5) is encased in glass (10) and introduced into a through opening (4) of a base body (1) in a hermetically sealed manner by melting the metal pin (5) into the glass (10)
Implementation Method 3
the metal, preferably the metal of the base body, shrinks onto the fixing material, for example the glass plug
Data Source
Figure 1a~1b
Figure 2~3b
Figure 4
AI summary
Metal fixing material feedthrough for igniters of airbags and/or seatbelt pretensioners, comprising at least one metal pin (5) which is fused into a through-opening (4) of a base body (1) in a glassy or glass-ceramic fixing material (10), and a top surface which faces the explosive and on which, in particular, an ignition bridge (9) can be attached or is attached, and a bottom surface which is opposite the top surface, wherein the at least one metal pin (5) and the base body (1) consist of a compatible material combination such that, with the ignition bridge (4) installed and/or with the top surface covered with a conductive film, an anode and/or cathode reaction on the top surface of the base body does not occur or only occurs to a small extent, characterized in that the stainless steel of the metal pin and the base body are selected such thatthat the stainless steel of the metal pin (5) and the base body (1) form a passivation film on their surface, preferably rather than an absorbed water film.