Tailgate Skin Retention Lip for Glue Distribution Control

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Solution Overview

Problem

The existing methods for assembling motor vehicle tailgates using molded plastic materials face challenges with complex geometries and uneven glue distribution, leading to structural fragility, incorrect positioning, and leaks due to excess or lack of glue at the junction zone between the tailgate box and skin.

Innovation Solution

Incorporating a retention lip on the tailgate skin that fits into a complementary cavity in the tailgate box, which retains the glue and acts as a bridge between the two components, preventing excess or lack of glue and ensuring proper assembly and sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a retention lip and fitting cavity system is added to control glue distribution, then manufacturing precision and sealing reliability are improved, but device complexity increases due to additional molded features

Engineering Contradiction:
Improveglue distribution uniformityVSAvoidtailgate skin structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The retention lip is integrated directly into the tailgate skin as a single molded piece, combining the skin and retention feature into one component. This reduces assembly steps while maintaining the glue distribution control function, thus improving manufacturing precision without proportionally increasing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The retention lip and fitting cavity are pre-formed during the molding process of the tailgate skin and box respectively. This preliminary action ensures proper glue retention geometry is already in place before assembly, enabling precise glue distribution control without adding complex post-processing steps.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If manual removal of excess glue is implemented, then sealing quality is improved, but productivity decreases due to costly and time-consuming manual operations

Engineering Contradiction:
Improvesealing qualityVSAvoidassembly speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The retention lip and fitting cavity system automatically controls glue distribution during the assembly process itself. The geometry of these features naturally prevents excess glue from reaching the junction zone, eliminating the need for manual glue removal operations while maintaining sealing quality.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system converts the potential harmful effect of excess glue into a beneficial control mechanism. By designing the retention features with specific geometries, the system channels excess glue into the fitting cavity where it is contained, transforming what would be a defect into a controlled feature that maintains both sealing quality and productivity.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Strength

If molded reinforcements with complex shapes are used to achieve structural resistance, then strength is improved, but ease of manufacture deteriorates due to demolding difficulties and production cost increases

Engineering Contradiction:
Improvetailgate box structural resistanceVSAvoiddemolding process
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The tailgate assembly is segmented into distinct functional components: the box with molded reinforcements for structural strength, and the skin with integrated retention features for assembly control. This segmentation allows each component to be optimized independently - the box for strength and the skin for manufacturing ease - while working together as a unified system.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3722128B1Improved tailgate box assembly and tailgate skin
Publication Date: 2021.12.15 COMPAGNIE PLASTIC OMNIUM SA
  • EP3722128B1 patent drawingFigure 1~3
  • EP3722128B1 patent drawingFigure 4~7
  • EP3722128B1 patent drawingFigure 8

AI summary

Assembly (8) of a tailgate housing (10) of a motor vehicle and a tailgate skin (14) intended to be attached to the tailgate housing (10) by bonding, the tailgate housing (14) comprising a housing (12) for receiving the tailgate skin (14). The tailgate skin (14) is provided with a retention lip (30) forming an extension of the tailgate skin (14). The housing (12) formed in the tailgate housing (10) includes a retention shoulder (32) defining a recess (28) with a shape complementary to that of the retention lip (30). Once fitted into the insertion cavity (28), the retention lip (30) forms a lid closing the insertion cavity (28) and flush with an external surface (10S) of the tailgate box (10).