Mold Movable Wall for Armrest Covering Shape Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for manufacturing interior trim panel parts, such as armrests, result in uneven comfort and incorrect positioning of style seams due to stretching during the mold closing process, leading to irregular profiles and aesthetics issues.

Innovation Solution

A method involving a mold with a movable concave wall that applies pressure to the covering during mold closure, ensuring it maintains the predetermined shape, and releasing pressure before plastic injection, combined with a stiffening insert to enhance rigidity and correct seam positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If the mold is closed to stamp the coating and curve the part, then the convex shape is formed, but the coating stretches in two opposite directions causing thinner coating at the convex shape and irregular profile

Engineering Contradiction:
Improveconvex shapeVSAvoidcoating thickness uniformity
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The concave wall is positioned in advance (in the open mold position) to pre-support the coating at the convex shape location before the mold closing action occurs. This preliminary positioning prevents the coating from stretching during the stamping process, maintaining uniform thickness while still allowing the convex shape to be formed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The concave wall acts as an intermediary element between the male and female mold parts. It provides localized support to the coating during the mold closing process, mediating the force application to prevent excessive stretching at the convex shape while still allowing the overall shaping to occur.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Shape

If the mold is closed to stamp the coating, then the convex shape is formed, but style seams are incorrectly positioned due to stretching

Engineering Contradiction:
Improveconvex shapeVSAvoidseam positioning accuracy
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The concave wall is positioned in advance to pre-support the coating at the convex shape location before the mold closing action occurs. This preliminary positioning prevents the coating from stretching during the stamping process, maintaining uniform thickness while still allowing the convex shape to be formed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The concave wall acts as an intermediary element between the male and female mold parts. It provides localized support to the coating during the mold closing process, mediating the force application to prevent excessive stretching at the convex shape while still allowing the overall shaping to occur.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the concave wall is kept fixed during mold closing, then the mold structure is simple, but the coating stretches and deforms at the convex shape

Engineering Contradiction:
Improvemold structureVSAvoidcoating profile uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The concave wall is made movable rather than fixed, allowing it to dynamically adjust its position during the mold closing process. It moves from the open mold position (projecting toward the male part) to the closed mold position (retracted), enabling it to provide support when needed while clearing the path for injection when required.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mold structure is segmented by separating the concave wall from the main mold body, allowing independent movement of the concave wall. This segmentation enables the concave wall to perform its specific function of supporting the coating without constraining the overall mold closing and injection actions.

Inventive Principle:
Principle #1Segmentation

4Manufacturing precision

If the concave wall remains in extreme projection position during mold closing, then the coating is well supported, but it blocks the injection of plastic material

Engineering Contradiction:
Improvecoating supportVSAvoidplastic material injection
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The concave wall is made movable rather than fixed, allowing it to dynamically adjust its position during the mold closing process. It moves from the open mold position (projecting toward the male part) to the closed mold position (retracted), enabling it to provide support when needed while clearing the path for injection when required.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The concave wall performs periodic movement through different positions: projecting during mold opening to support the coating, retracting during mold closing to allow injection, and potentially projecting again during ejection. This periodic action sequence ensures both coating support and successful material injection.

Inventive Principle:
Principle #19Periodic action

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

This approach ensures a regular profile and improved comfort by preventing deformation and correctly positioning the covering, resulting in a more aesthetically pleasing and functional interior trim panel.

Implementation Method 1

the displacement of the concave wall (27), from the position of extreme projection to the position of slight projection, is carried out by means of the prominent shape (19) of the male part (18) which pushes back this wall (27) when closing the mould

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2127845B1Improved method for manufacturing a piece forming an armrest equipped with a comfort coating
Publication Date: 2011.05.11 EUROSTYLE SYST
  • EP2127845B1 patent drawingFigure 1~3
  • EP2127845B1 patent drawingFigure 4~5
  • EP2127845B1 patent drawingFigure 6~7

AI summary

The method involves fixing a comfort covering by its end walls between female and male parts of a mold in a plane configuration. The covering is pressed by a prominent shape of the male part, and a part of the covering is bent to form a convex central wall (6). A plastic material is injected below the comfort covering. The pressure is applied on the covering part located with respect to the prominent shape of the male part for fixing the covering part against the prominent shape during closing of the mold. An independent claim is also included for a plastic material injection mold for fabricating a piece of an internal covering panel of a motor vehicle.