Fuel Injection Valve Plug Overmolding for Dimensional Accuracy
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Solution Overview
Problem
Existing fuel injection valves face challenges in achieving dimensional accuracy and splash-proof connectivity while maintaining a slim, elongated design due to high injection pressures during molding, which can damage components and complicate the manufacturing process.
Innovation Solution
The fuel injection valve design incorporates a plug with a rib and electrical connection elements, where the plug is overmolded with a housing part, allowing for precise production and reduced component count, featuring a support element and labyrinthine structure for secure connectivity, enabling lower injection pressures and simpler manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high injection pressure is used during molding, then the injection speed and filling time are improved, but components of the actuator can be damaged
Solution Approach 1:
The plug is segmented into a base body and a separately molded housing part. The base body with electrical connection elements is first molded, then the housing part is overmolded onto it. This segmentation allows the base body to be molded under controlled pressure without damage, while the overmolding process completes the housing formation.
Solution Approach 2:
The base body of the plug with electrical connection elements is molded in advance as a preliminary step before the housing part is overmolded. This preliminary action allows precise positioning and protection of sensitive electrical components before the main housing molding operation, preventing damage during the high-pressure overmolding process.
2Shape
If the fuel injection valve is made slimmer and elongated, then installation requirements are met, but the distance from injection point to end of injection mold increases
Solution Approach 1:
The plug structure utilizes dimensional optimization by extending the electrical connection element axially while keeping the base body compact. The housing part is overmolded to surround the base body, creating a slim overall profile. This dimensional arrangement achieves the required elongated shape without proportionally increasing the injection mold length.
3Manufacturing precision
If the plug is produced as an assembly with the electrical connection element, then dimensional accuracy is improved, but the manufacturing process complexity increases
Solution Approach 1:
The base body and housing part of the plug are combined through overmolding, where the housing part is molded directly onto the base body. This merging creates a integrated component with high dimensional accuracy and splash-proof electrical connections, while the overmolding process itself integrates multiple functions (structural housing and electrical protection) into a single manufacturing step.
Data Source
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AI summary
A fuel injector which includes an actuator having an electrical contact element, a plug, a fuel supply pipe, and an injection-molded housing part. The plug has a base body, an electrical connection element for an electrical connection with the electrical contact element of the actuator, and a rib which projects from the base body, the injection-molded housing part surrounding the electrical connection element of the plug and being injection-molded on the rib of the plug and the fuel supply pipe.