Electrical Connector Overmolding With Inductive Gap Sealing
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Solution Overview
Problem
Electrical connecting parts, especially those exposed to outdoor environments, face issues with liquid penetration due to shrinkage-induced gaps in their housings, compromising safety and requiring enhanced sealing to prevent damage and ensure long-term reliability.
Innovation Solution
A method involving inductive heating of the contact element to melt and fill the adjacent plastic housing, sealing the gaps and improving adhesion, using thermoplastic materials and optional external pressure to ensure a tight seal without altering the external shape of the housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the housing is overmolded with plastic to enclose the contact element, then the contact element is protected and enclosed, but shrinkage occurs during cooling creating gaps that compromise sealing
Solution Approach 1:
The patent applies local heating to change the temperature parameter of the contact element, which in turn melts the adjacent plastic housing material. This parameter change allows the plastic to flow and fill the gaps created by shrinkage, restoring the sealing function without requiring redesign of the entire molding process
Solution Approach 2:
The patent converts the harmful effect of plastic shrinkage (which creates gaps) into a beneficial process. By heating the contact element after molding, the adjacent plastic melts and flows into the gap areas, transforming the defective shrunk housing into a sealed structure. The harmful shrinkage gaps become the target areas for beneficial plastic flow and sealing
2Productivity
If the housing shrinkage is allowed to occur naturally during cooling, then the molding process is simple and fast, but gaps are created that allow liquid ingress
Solution Approach 1:
The patent performs a preliminary sealing action by heating the contact element and melting the adjacent plastic before final cooling and solidification. This preliminary melting and flowing of plastic into gap areas occurs while the plastic is still in a moldable state, ensuring seals are formed before the housing fully cools and solidifies
Solution Approach 2:
The patent utilizes the phase transition of the thermoplastic material from solid to molten state through localized heating. The plastic adjacent to the heated contact element melts and flows to fill gaps, then re-solidifies upon cooling, creating a sealed structure. This phase transition enables the plastic to adapt to the gap geometries and form effective seals
3Reliability
If additional sealing measures are implemented to prevent liquid ingress, then safety and protection are improved, but manufacturing effort and complexity increase
Solution Approach 1:
The patent employs a self-service sealing mechanism where the existing contact element and housing materials are utilized to create the seal. By heating the contact element, the adjacent housing plastic melts and self-flow into the gap areas, automatically sealing themselves without requiring external sealing components or complex assembly operations
Solution Approach 2:
The patent merges the sealing function with the existing contact element and housing structure. The contact element serves dual purposes: as the electrical conductor and as the heat source for melting adjacent plastic. The housing plastic serves dual purposes: as the structural enclosure and as the sealing material. This merging eliminates the need for separate sealing components and simplifies the overall structure
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 method effectively seals the housing from its surroundings, enhancing safety and reliability by eliminating gaps and improving adhesion, while reducing manufacturing effort and costs, and allowing for efficient production of various electrical connecting parts without significant setup times.
Implementation Method 1
The contact element is inductively heated in such a way that the metal of the contact element heats up
Implementation Method 2
a region of the housing adjacent to the contact element melts such that the molten plastic of the housing encloses the contact element more tightly
Implementation Method 3
the metal of the contact element heats up, and, as a result, a region of the housing adjacent to the contact element melts
Data Source
Figure 1~3
Figure 4~6
Figure 7A~7C
AI summary
In a method for manufacturing an electrical connector, the connector comprises a metal contact element and a plastic housing that at least partially encloses the contact element. The process involves enclosing the contact element with the plastic by overmolding and inductively heating it such that the metal element heats up. This causes an area of the housing adjacent to the contact element to melt, resulting in the molten plastic housing forming a tighter seal around the contact element.