Piston Heat Insulating Layer Crack Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for forming heat insulating layers on piston surfaces in engines lead to cracking and peeling when subjected to knocking, particularly in the squish area, resulting in reduced heat insulation effectiveness and potential damage.
Innovation Solution
Applying pressing stress to the heat insulating layer on the piston's squish area surface, using a combination of hollow particles and a binder like silicone-based resin, and performing a baking process to enhance the layer's strength and adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a heat insulating layer is formed on the squish area surface, then cooling loss is reduced, but cracks and peeling occur due to knocking
Solution Approach 1:
Pressure is applied to the heat insulating layer in advance during the manufacturing process, before the piston is subjected to knocking during operation. This preliminary compression increases the layer's resistance to tensile stress, preventing cracks from forming when knocking occurs later.
Solution Approach 2:
The physical state of the heat insulating layer is changed by applying pressure during manufacturing, which modifies its mechanical properties. The pressed heat insulating layer has higher density and improved tensile strength, enabling it to withstand the stresses from knocking while maintaining heat insulation performance.
2Loss of energy
If a heat insulating layer is formed on the squish area surface, then heat insulation property is improved, but the layer becomes damaged and peeled
Solution Approach 1:
The heat insulating layer is pre-compressed during manufacturing to increase its structural integrity before it is exposed to the harsh operating conditions. This preliminary action ensures the layer can withstand thermal and mechanical stresses without damage or peeling.
Solution Approach 2:
The heat insulating layer is constructed as a composite material containing hollow particles dispersed in a binder material. This composite structure provides both heat insulation properties and improved mechanical strength, allowing the layer to maintain integrity under knocking conditions while retaining thermal insulation performance.
3Object-affected harmful factors
If heat insulating layer is formed only on non-squish area, then knocking is suppressed, but cooling loss reduction is limited
Solution Approach 1:
The heat insulating layer is selectively formed only on the squish area surface of the piston crown, applying different thermal insulation properties to different regions. The pressed heat insulating layer in the squish area provides both heat insulation and knock suppression, while other areas maintain their original thermal characteristics.
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 method effectively increases the heat insulating layer's resistance to tensile stress, preventing cracks and maintaining its integrity even during knocking events, thus enhancing heat insulation and reducing damage.
Implementation Method 1
a binder material (32) that holds the hollow particles (31) on the top surface of the piston main body (19) and fills spaces among the hollow particles (31)
Implementation Method 2
a heat insulating layer (21) that is provided on a top surface of a piston main body (19) from the viewpoint of a reduction in cooling loss of a combustion chamber
Implementation Method 3
pressure is applied to the heat insulating layer (21) in advance, that is, pressing stress is applied to the heat insulating layer (21)
Data Source
AI summary
An object of the present invention is to, while forming a heat insulating layer on a squish area surface of a top surface of a piston main body, prevent generation of large cracks on the heat insulating layer and suppress damages and peeling of the heat insulating layer. To achieve this object, in the present invention, pressure is applied to a heat insulating layer provided on a top surface of a piston main body, that is, a pressing stress is applied to the heat insulating layer in advance.