Overmolded Bodywork De-Icing Element for Sensor Transparency

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Solution Overview

Problem

Existing methods for manufacturing plastic bodywork elements with integrated defrosting systems for sensors on motor vehicles are prone to corrosion and mechanical damage, leading to unreliable and short-lived installations that can disrupt the passage of electromagnetic waves.

Innovation Solution

A method involving overmolding a plastic bodywork element with a housing for connection plates and a serpentine heating track, ensuring precise positioning and protection from corrosion, while maintaining electromagnetic wave transparency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If connection plates and conductive tracks are placed in a mold and molded under them, then the defrosting system can be integrated into the bodywork element, but the connection plates and conductive tracks are exposed to corrosion and mechanical damage from the inner face

Engineering Contradiction:
Improveintegration of defrosting systemVSAvoidprotection from corrosion and mechanical damage
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The connection plates and heating tracks are nested within a protective plastic layer through overmolding. The plastic material completely covers the conductive components, creating a nested structure where the sensitive elements are enclosed within the robust outer shell, protecting them from corrosion and mechanical damage while maintaining electrical connectivity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention combines conductive materials (connection plates, heating tracks) with insulating and protective plastic materials through overmolding. This creates a composite structure where each material contributes its specific properties: the conductive materials provide electrical functionality while the plastic provides environmental protection and mechanical strength.

Inventive Principle:
Principle #40Composite materials

2Reliability

If pins are kept partly outside the molding area to maintain conductive property, then electrical connectivity is preserved, but the molding process becomes complex and the pins are vulnerable to damage

Engineering Contradiction:
Improveconductive propertyVSAvoidmolding process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pins are completely enclosed within the molded plastic structure rather than protruding outward. The overmolding process nests the conductive pins within the plastic matrix, allowing the molding to extend fully over them while maintaining electrical connectivity through the embedded configuration, thereby simplifying the molding process and protecting the pins.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If the heating track is positioned in a serpentine geometry to avoid obstructing electromagnetic waves, then electromagnetic wave passage is maintained, but the positioning accuracy must be extremely precise

Engineering Contradiction:
Improveelectromagnetic wave transparencyVSAvoidpositioning accuracy of heating track
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The serpentine heating track and connection plates are positioned and fixed in their precise geometrical configurations before the overmolding process. This preliminary positioning ensures that the electromagnetic wave-transparent geometry is established upfront, and the subsequent overmolding preserves this configuration while adding protective coverage, thereby maintaining precision without requiring post-processing adjustments.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If the defrosting system is installed on the bodywork element, then sensor operation in cold conditions is maintained, but vibrations and jolts can modify or damage the system over time

Engineering Contradiction:
Improvesensor operation in cold conditionsVSAvoidservice life of defrosting system
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The defrosting system components (connection plates, heating tracks, pins) are merged into a single integrated unit through the overmolding process. This combining creates a unified structure where all components are mechanically bonded and protected together, preventing relative movement between parts during vibrations and jolts, thereby extending the service life while maintaining defrosting functionality.

Inventive Principle:
Principle #5Merging (Combining)

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 reliable, long-lasting, and waterproof installation of the defrosting system, ensuring accurate sensor operation and extended lifespan by preventing mechanical damage and corrosion, while maintaining the integrity of electromagnetic wave transmission.

Implementation Method 1

a heating track made up of wires capable of transforming electrical energy into thermal energy

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a pin with a pointed perforating shape is used so that the plastic element is pierced with said pin when the connection plate is positioned

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Data Source

PatentEP3758907B1Method for manufacturing an element of a bodywork part comprising a de-icing system
Publication Date: 2024.11.06 OPMOBILITY SE
  • EP3758907B1 patent drawingFigure 1A~1D
  • EP3758907B1 patent drawingFigure 2~4

AI summary

The invention relates to a method for manufacturing an element of a bodywork part, characterised in that: a plastic element is manufactured which comprises at least one housing disposed on a first side of the element; at least one connecting plate, which comprises a pin, is positioned in the housing such that the pin projects over a second side of the plastic element opposite the first side; at least one heating track is positioned on a first and second side in contact with the connecting plate; the side of the plastic element bearing the heating track is overmoulded.