Plug-In Connection With SMA Securing Element for Contact Reliability
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Solution Overview
Problem
Electrical plug-in connections in vehicles face reliability issues due to increased transfer resistance and contact deterioration, leading to potential thermal events and outages, especially in safety-relevant loads, which existing solutions fail to adequately address without redundant power paths or complex diagnosis systems.
Innovation Solution
Incorporating a shape memory alloy (SMA) securing element that deforms at a specific transition temperature to enhance mechanical contact between the blade and lamella pair, either before or after startup, thereby increasing operational reliability and reducing deterioration effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional plug-in connections are used with metallic blades and lamella pairs, then the connection allows for detachable electrical contact, but the contact force decreases over time due to deterioration effects such as relative movement and oxide layer formation
Solution Approach 1:
The patent changes the material parameter of the securing element from conventional elastic materials to shape memory alloy, which fundamentally alters the contact force characteristics. The SMA element's phase transition properties enable it to maintain high contact force over time by automatically compensating for deterioration effects through temperature-dependent shape recovery.
Solution Approach 2:
The securing element with shape memory alloy performs self-adjustment of contact force based on temperature conditions. When temperature increases due to deterioration or operation, the SMA element automatically changes shape to restore optimal contact force, eliminating the need for external adjustment mechanisms or redundant power paths.
2Reliability
If stronger contact forces are applied to improve electrical contact properties, then the contact reliability increases, but the maximum admissible plug-in forces are exceeded
Solution Approach 1:
The securing element provides dynamic contact force adjustment based on operating conditions. The shape memory alloy automatically modulates the contact force between blade and lamella pair according to temperature, providing stronger contact when needed (during operation or deterioration) while maintaining low force during plugging operations.
Solution Approach 2:
The patent utilizes the phase transition properties of shape memory alloy between austenite and martensite phases. During plugging, the SMA is in the soft martensite phase requiring low force. During operation or deterioration, temperature increase triggers transition to the austenite phase, automatically increasing contact force to maintain reliable electrical contact.
3Reliability
If material coatings or structural approaches are used to protect against deterioration, then the contact plane is protected, but the device complexity increases
Solution Approach 1:
The securing element with shape memory alloy provides self-protection against deterioration effects. When temperature increases due to oxide layer formation or contact resistance, the SMA automatically changes shape to restore optimal contact force, eliminating the need for complex diagnosis systems or redundant power paths while maintaining protection against deterioration.
4Reliability
If redundant power paths or diagnosis concepts are implemented to ensure availability of safety-relevant loads, then the system reliability increases, but the device complexity and cost increase
Solution Approach 1:
The securing element with shape memory alloy provides self-monitoring and self-correction capabilities. The temperature-dependent shape change automatically responds to deterioration effects, providing inherent diagnosis and correction functions that eliminate or reduce the need for separate diagnosis systems, sensors, or redundant power paths while ensuring availability of safety-relevant loads.
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 SMA securing element enhances the contact force between the blade and lamella pair, improving the reliability of current conduction and power supply for safety-relevant loads, potentially eliminating the need for redundant power paths and complex diagnosis systems, while allowing for improved contact during normal operation or in response to deterioration.
Implementation Method 1
the at least one securing element is made of a shape memory alloy and changes in shape or deforms from its cold shape to its hot shape when heated to its transition temperature
Implementation Method 2
changes in shape or deforms from its cold shape to its hot shape when heated to its transition temperature
Data Source
AI summary
An electrical plug-in connection includes a first plug-in connection element having a plug housing with at least one blade, and a second plug-in connection element having a socket housing with at least one socket in the form of a lamella pair. The lamella pair receives a blade of the first plug-in connection element, wherein the plug-in connection includes a securing element made of a shape memory alloy. The securing element is deformed upon reaching its conversion temperature. The securing element may also exhibit a one-way memory effect, wherein it is brought, after the first and second plug-in connection elements are plugged together, to a temperature which is equal to or greater than its conversion temperature.