PTC Heatable Media Line for Hotspot-Free Connector Heating

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Solution Overview

Problem

Existing heatable media lines for vehicles face issues with hotspot formation and high production costs due to variance in heat requirements and complex control strategies, leading to inefficient heating and potential damage from overheating.

Innovation Solution

A heatable media line with a heating strip braid coiled around the media line and connectors, using electrically conductive plastic with nano-sized particles for self-regulating heat distribution, achieving an asymptotic temperature profile and reducing the need for additional control devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If heating wires or heating strands are arranged on the outside around the media line and line connectors, then the media line and connectors can be heated, but hotspot areas occur due to overlapping heating conductors leading to local excessive heat supply

Engineering Contradiction:
Improveheating capabilityVSAvoidhotspot formation
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical/coil-based heating strand arrangement with an electrically conductive plastic material that provides heating through electrical conduction. This material is applied as a coating or layer on the media line and connectors, eliminating the need for discrete heating wires that overlap and create hotspots. The continuous conductive layer distributes heat uniformly without localized accumulation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state and properties of the heating element from discrete wire strands to a continuous plastic material with specific electrical conductivity. By adjusting the electrical conductivity parameter of the plastic material, uniform heat distribution is achieved across the surface, preventing hotspot formation while maintaining effective heating capability.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If individual design of heatable media line is provided for each application, then differentiated heat input is achieved, but production costs increase due to high variance and need for multiple strand variants

Engineering Contradiction:
Improvedifferentiated heat inputVSAvoidproduction cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent creates a universal heating solution using electrically conductive plastic material that can be applied to media lines and connectors of various sizes and configurations. The same basic material and application process works across different applications, eliminating the need for multiple specialized heating strand variants. Differentiation in heat input is achieved by varying the thickness or conductivity of the plastic coating rather than changing the fundamental heating element design.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent enables differentiated heat input by adjusting parameters of the electrically conductive plastic material, such as its electrical conductivity, thickness, or application coverage area. This allows customization for different thermal requirements without changing the basic heating mechanism or requiring multiple types of heating strands, thereby reducing production complexity and cost.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If heating strands are returned in the area of line connectors, then electrical contact is possible, but strand accumulation occurs leading to hotspot areas

Engineering Contradiction:
Improveelectrical contact capabilityVSAvoidhotspot formation
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical strand return and contact system with an electrically conductive plastic coating that extends continuously over the line connectors. Electrical contact is achieved through this continuous conductive layer rather than through returned heating wires, eliminating strand accumulation and the associated hotspot problem while maintaining electrical connectivity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 efficient, self-regulating heat distribution that prevents hotspot formation and reduces production costs by eliminating the need for multiple strand variants and control electronics, ensuring consistent heat output across the media line.

Implementation Method 1

at least one heating device for heating the through the media line and the Includes line connector flowing medium

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

uses electrically conductive plastic with nano-sized particles for self-regulating heat distribution, achieving an asymptotic temperature profile

Methodology Applied
Scientific EffectPTC effect (positive temperature coefficient): Thermistor

Data Source

PatentEP3092432B1Heatable media line, method for the production thereof, and circuit assembly for a heatable media line
Publication Date: 2022.03.09 VOSS AUTOMOTIVE GMBH
  • EP3092432B1 patent drawingFigure 1
  • EP3092432B1 patent drawingFigure 2
  • EP3092432B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a special type of heatable media line (1, 1a, 1b), in particular in order to avoid hotspots, for conducting at least one medium (3) at risk of freezing, wherein the heatable media line (1, 1a, 1b) comprises at least one media line (10, 10a, 10b) having two line connectors (11, 11a, 11b, 12, 12a, 12b) for connecting the media line (10, 10a, 10b) to at least one component (6, 7) and/or another heatable media line (1, 1a, 1b) and at least one heating device for heating the medium (3) flowing through the media line (10, 10a, 10b) and the line connectors (11, 11a, 11b, 12, 12a, 12b), and wherein the heating device comprises a stranded heating-strip wire (2, 2a, 2b), which extends in such a way that the stranded heating-strip wire is at least partially wound around the media line (10, 10a, 10b) and the at least one line connector (11, 11a, 11b, 12,12a, 12b) thereof and is brought into highly thermally conductive contact with said line connector, which stranded heating-strip wire comprises at least two contact conductors (25, 26), which are in contact with at least one electrically conductive plastic having nano-sized electrically conductive particles and which are connected in parallel with regard to the resistances (R) thereof, wherein the stranded heating-strip wire (2, 2a, 2b) exhibits a PTC effect during the heating of the media line (10, 10a, 10b) and the at least one line connector (11, 11a, 11b, 12, 12a, 12b) thereof in connection with the medium (3) to be heated, in such a way that, proceeding from a media temperature of -11°C to -40°C, an approximately asymptotic temperature curve within a temperature range of +5°C to 80°C results.