Ceramic-Insulated Exhaust Interfaces for High-Temperature Aftertreatment

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Solution Overview

Problem

Existing electrical interfaces in exhaust gas aftertreatment devices for vehicles, particularly those required for the EURO 7 emissions standard, face issues with thermal insulation as silicone cable insulation jackets degrade at high temperatures, failing to meet ADR and TÜV regulations.

Innovation Solution

A thermally insulated interface arrangement using a ceramic material for the thermal insulation jacket, which surrounds the electrical interface, ensuring effective thermal insulation while maintaining minimal installation space and preventing silicone degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If silicone cable insulation is used for electrical interfaces in exhaust gas heating systems, then ease of manufacture and flexibility are improved, but thermal resistance deteriorates at high temperatures above 250°C causing decomposition and insulation failure

Engineering Contradiction:
Improveease of manufactureVSAvoidthermal resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The thermal insulation system is divided into multiple segments: an inner thermal insulation layer directly surrounding the electrical interface, an outer thermal insulation layer, and a protective casing. This segmented approach allows each layer to be optimized for its specific function while working together to achieve the required thermal protection below 200°C at the interface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs composite material construction with different thermal insulation layers having distinct material properties. The inner layer uses material with specific thermal resistance characteristics, while the outer layer provides additional insulation and environmental protection. This composite structure enables the system to maintain reliable thermal insulation performance in the high-temperature exhaust gas environment.

Inventive Principle:
Principle #40Composite materials

2Reliability

If thermal insulation is increased to protect electrical interfaces from high temperatures, then thermal resistance and reliability are improved, but installation space requirements increase

Engineering Contradiction:
Improvethermal insulationVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The thermal insulation structure implements a nested configuration where the inner thermal insulation layer is positioned within or adjacent to the outer thermal insulation layer, and both are integrated within the protective casing. This nesting arrangement maximizes thermal insulation effectiveness while minimizing the overall volume and installation space required for the electrical interface assembly.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent optimizes the thermal insulation geometry by transitioning from a simple radial thickness approach to a multi-dimensional configuration. The inner and outer layers are arranged in specific spatial relationships with varying thicknesses at different positions, creating an optimized thermal barrier that achieves required insulation performance with reduced overall dimensions and installation space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 ceramic insulation maintains the electrical interface temperature below 200°C, allowing the use of silicone cable insulation and compliance with ADR and TÜV regulations, enabling the exhaust gas heating system to meet EURO 7 standards.

Implementation Method 1

a thermal insulation jacket (7) enclosing the first electrical interface (3.1)... The thermal insulation jacket (7) comprises a ceramic material or is formed from a ceramic material

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4600470A1Thermally insulated interface assembly and exhaust gas aftertreatment device
Publication Date: 2025.08.13 DAIMLER TRUCK AG
  • EP4600470A1 patent drawingFigure 1~4
  • EP4600470A1 patent drawingFigure 5
  • EP4600470A1 patent drawing

AI summary

According to a first aspect, the application relates to a thermally insulated interface arrangement (1) for an exhaust gas aftertreatment device (6), comprising: - a first electrical interface (3.1); - an inner casing that encloses the first electrical interface (3.1); and - a thermal insulation casing that encloses the inner casing, wherein the thermal insulation casing comprises a ceramic material or is formed from a ceramic material. Alternatively, according to a second aspect, the application relates to a thermally insulated interface arrangement (1) for an exhaust gas aftertreatment device (6), comprising: - a first electrical interface (3.1); - a gap that encloses the first electrical interface (3.1), wherein the gap is formed by a gap between the first electrical interface (3.1) and an outer casing that encloses the gap; and - an intermediate element that is arranged at the first electrical interface (3.1).1), wherein the intermediate element (21) is adjacent to the gap and is encased by the outer casing (19). Furthermore, the invention relates to an exhaust gas aftertreatment device (6) with a thermally insulated interface arrangement (1) according to the first or second aspect.