Piston Layer Stack for Thermal Management

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing piston designs face challenges in managing temperature peaks and heat dissipation, leading to thermal throttling and material damage due to inadequate heat management, which affects engine efficiency and longevity.

Innovation Solution

A piston with a layer stack on the crown comprising a heat-insulating material and a heat-conducting material, where the heat-insulating material decouples heat conduction from the piston crown, and the heat-conducting material ensures even temperature distribution, reducing local temperature peaks and enhancing corrosion protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a heat-insulating coating is applied to the piston to reduce heat loss from the combustion chamber, then heat loss is reduced and engine efficiency is improved, but local temperature peaks on the piston crown are amplified and thermal stress increases

Engineering Contradiction:
Improveheat loss from combustion chamberVSAvoidlocal temperature peaks on piston crown
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The coating is divided into multiple functional layers: a heat-insulating layer (containing ceramic particles like aluminum oxide, silicon oxide, or magnesium oxide) to reduce overall heat loss, and a heat-conducting top layer (metallic or ceramic) to dissipate local temperature peaks. This segmentation allows each layer to address different thermal management requirements simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coating structure transitions from uniform insulation to spatially varying properties: the heat-insulating layer provides thermal barrier properties throughout, while the heat-conducting top layer is strategically positioned to address areas prone to temperature peaks. This local quality differentiation resolves the contradiction between insulation and peak temperature control.

Inventive Principle:
Principle #3Local quality

2Loss of energy

If a heat-insulating coating is applied to reduce heat loss, then thermal efficiency is improved, but the coating and underlying material are subjected to intense thermal stress resulting in damage

Engineering Contradiction:
Improveheat loss reductionVSAvoidcoating integrity and material durability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The coating is constructed as a composite material system combining heat-insulating ceramic particles (aluminum oxide, silicon oxide, magnesium oxide) with a heat-conducting metallic or ceramic matrix. This composite structure provides both thermal insulation to reduce heat loss and thermal conduction pathways to relieve thermal stress, thereby improving coating integrity and underlying material durability while maintaining energy efficiency.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If the piston crown is coated with heat-insulating material to prevent corrosion and heat loss, then corrosion resistance is improved, but temperature peaks are not dissipated leading to thermal throttling and reduced ignition delay

Engineering Contradiction:
Improvecorrosion at piston crownVSAvoidignition delay and charge cycle efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The coating is segmented into a corrosion-protective heat-insulating layer containing ceramic particles and a heat-conducting top layer. This segmentation allows the insulating layer to prevent corrosion and reduce heat loss while the conductive top layer dissipates temperature peaks, preventing thermal throttling and maintaining optimal ignition delay.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The composite coating structure combines corrosion-resistant ceramic particles (aluminum oxide, silicon oxide, magnesium oxide) with a heat-conducting matrix, creating a multi-functional protective layer that simultaneously provides corrosion protection, thermal insulation, and temperature peak dissipation, thereby maintaining engine productivity.

Inventive Principle:
Principle #40Composite materials

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 configuration increases engine efficiency by retaining heat in the combustion chamber, improving exhaust gas treatment, and extending the service life of components by evenly distributing heat and reducing thermal stress.

Implementation Method 1

a first layer (21) comprising a heat-insulating material, which is directly or indirectly adjacent to the surface of the piston crown

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

a second layer (22) comprising a heat-conducting material, which is directly or indirectly adjacent to the first layer (21)

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentEP3097300B1Piston for a piston machine
Publication Date: 2021.05.05 VOLKSWAGEN AG
  • EP3097300B1 patent drawingFigure 1~3

AI summary

The invention relates to a piston (10) for a piston machine. The piston (10) consists of a steel or a lightweight metal alloy (15) in some regions and comprises a layer stack (20) arranged on a piston base (11) of the piston (10). The layer stack (20) comprises at least one first layer (21) which directly or indirectly adjoins a surface of the piston base (11) and which comprises a heat-damping material and a second layer (22) which directly or indirectly adjoins the first layer (21) and which contains a heat-conducting material. According to the invention, the diameter (dS) of the layer stack (20) is smaller than the diameter (dK) of the piston base (11). The invention further relates to a piston machine comprising a piston according to the invention.