Plastic Injection Moulded Part with Sensor Recess

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Solution Overview

Problem

Existing methods for producing plastic injection molded components with sensor holders, such as two-component injection molding, result in visible sensors and inadequate heat conduction, leading to surface disturbances and inefficient temperature management.

Innovation Solution

A method involving a temperature-controlled stamp forming a bead on the surface of the plastic injection molded component, where the stamp is pressed into the component to create a recess for the sensor, with precise temperature control and limited melting zone to maintain surface integrity and secure sensor holding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two-component injection molding is used to create sensor holders, then the sensor can be securely held, but the visible surface is disturbed and sensors remain visible

Engineering Contradiction:
Improvesensor holding securityVSAvoidsurface integrity
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The process is segmented into two distinct stages: first, the plastic component is injection molded with a recess; second, a separate hot stamping operation creates the bead structure. This segmentation allows each operation to be optimized independently, ensuring both secure sensor holding and surface integrity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The recess is pre-formed during injection molding before the hot stamping operation. This preliminary action prepares the plastic material in a state that is ready to receive the bead structure, ensuring proper material flow and containment while maintaining the visible surface quality.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If heat is applied to form the bead structure, then the plastic material becomes moldable, but excessive heat conduction causes surface disturbances

Engineering Contradiction:
Improvematerial moldabilityVSAvoidheat distribution
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The heating is applied locally only to the specific area where the bead structure is to be formed, rather than heating the entire component. This localized heating approach allows the plastic material at the bead formation zone to become moldable while keeping the visible surface and other areas at temperatures that prevent unwanted material flow or surface disturbances.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The hot stamping operation is performed rapidly, introducing heat quickly and removing it just as quickly. This brief, intensive heating cycle is sufficient to locally soften the plastic material for bead formation but limits the total thermal exposure, preventing heat conduction to surrounding areas and maintaining surface integrity.

Inventive Principle:
Principle #21Skipping (Rushing through)

3Reliability

If the stamp is pressed deeply to form the bead, then secure sensor holding is achieved, but the visible surface is disturbed

Engineering Contradiction:
Improvesensor holding securityVSAvoidsurface quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The stamping force is concentrated locally at the bead formation zone, creating deep containment structures only where needed for sensor holding. The visible surface areas remain unaffected by the stamping pressure, maintaining their original quality and appearance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The recess is pre-formed to the correct depth and geometry during injection molding, providing a boundary that limits the bead formation to the desired depth. This preliminary structure ensures that even with significant stamping force, the bead will not deform the visible surface as the recess walls provide containment.

Inventive Principle:
Principle #10Preliminary 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 method allows for secure sensor holding without disturbing the visible surface and achieves a localized, short-term temperature increase, enhancing the production of plastic components with embedded sensors.

Implementation Method 1

pressing the temperature-controlled punch into the surface of the plastic injection-molded component to form an annular bead in the annular space by displacing molten material of the plastic injection-molded component in the direction of the annular space

Methodology Applied
Scientific EffectLocalized heating and melting: Melting

Implementation Method 2

cooling the punch (3) and lifting it off the surface

Methodology Applied
Scientific EffectCooling and solidification: Freezing

Data Source

PatentEP4151384B1Plastic injection moulded part and method for manufacturing plastic injection moulded parts
Publication Date: 2024.10.02 MAGNA EXTERIORS GMBH
  • EP4151384B1 patent drawingFigure 1a~1c
  • EP4151384B1 patent drawingFigure 2

AI summary

Method for manufacturing a plastic injection-molded component from a plastic with at least one recess for receiving sensors, comprising the following steps: manufacturing the plastic injection-molded component in a tool with an upper and lower tool half, removing the upper tool half and inserting a temperature-controlled punch guided in a sleeve, placing the sleeve with an integrated annular space on the surface of the injection-molded component, forming an annular bead in the annular space, pressing the temperature-controlled punch into the surface of the injection-molded component, cooling the punch and removing it from the surface.