Welded Lug Connector for Exhaust Heater Terminal Reliability
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Solution Overview
Problem
Exhaust after-treatment systems face reliability issues due to high heat causing failure in electrical connections between heaters and conductive cables, leading to increased electrical resistance and potential failure of mechanical fasteners like nuts and bolts.
Innovation Solution
A welded lug connector is used to couple electrically conductive cables directly to electrical terminals, with heat shields and crimping to reduce heat transfer and resistance, ensuring a reliable electrical connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If mechanical fasteners (nuts and bolts) are used to connect electrical terminals to cables, then the connection can be easily assembled, but the connection reliability deteriorates due to high heat causing fastener failure
Solution Approach 1:
The patent replaces the mechanical fastening system (nuts and bolts) with a welding system that creates a metallurgical bond between the electrical terminal and cable lug. This substitution eliminates the mechanical components that fail under thermal stress while maintaining assembly feasibility through standardized welding procedures.
Solution Approach 2:
The patent changes the connection method from mechanical (reversible, tolerance-based) to thermal (permanent, diffusion-based). By applying heat and pressure during welding, the materials undergo parameter changes at the microstructural level, creating a bond that is resistant to the thermal environment where mechanical fasteners would fail.
2Device complexity
If electrical terminals are positioned close to the heater, then the electrical connection is more compact, but the temperature increases causing fastener failure and increased electrical resistance
Solution Approach 1:
The patent applies heat shields that are intentionally designed to absorb thermal energy and then be discarded or replaced. These heat shields act as sacrificial components that protect the electrical connection by absorbing excess heat, allowing the connection to remain compact while managing thermal exposure through replaceable protective elements.
Solution Approach 2:
The patent introduces heat shields as intermediary components between the heater and electrical terminal. These shields mediate the thermal interaction by absorbing and redirecting heat away from the electrical connection, enabling the terminal to remain in close proximity to the heater without direct thermal damage.
3Volume of moving object
If space between wires of electrically conductive cable is reduced, then the cable is more compact, but electrical resistance increases due to high temperatures
Solution Approach 1:
The patent applies thermal management parameters (heat shields, positioning, cooling) to maintain the electrical and physical properties of the cable wires. By controlling the thermal environment, the wires can maintain low resistance even in compact configurations where heat generation would normally increase resistance and reduce conductivity.
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 solution provides a more reliable and low-resistance connection between cables and terminals, enhancing the durability and efficiency of exhaust after-treatment systems.
Implementation Method 1
The at least one electrically conductive cable is coupled to the at least one electrical terminal of the electrically powered heater by a welded connection directly between the lug connector of the at least one electrically conductive cable and the at least one electrical terminal
Implementation Method 2
prior to welding of the lug connector to the electrical terminal, a pair of heat shields may be positioned on opposing sides of the welding location
Implementation Method 3
The lug connector may be crimped to the electrically conductive wires therein. The lug connector may be crimped such that wires of a portion of the electrically conductive cable are compacted within the lug connector
Data Source
AI summary
An exhaust after-treatment system configured to reduce emissions present in exhaust received from an engine is provided and may include an electrically powered heater and an electrically conductive cable. The electrically powered heater may be configured to selectively heat a component of the exhaust after-treatment system and/or exhaust moving through the exhaust after-treatment system during operation. The electrically powered heater may include a heating element and an electrical terminal. The electrically conductive cable may be configured to supply electrical power to the electrically powered heater. The electrically conductive cable may include a lug connector. The electrically conductive cable may be coupled to the electrical terminal of the electrically powered heater by a welded connection directly between the lug connector of the electrically conductive cable and the electrical terminal. A connector lug is also disclosed herein.