Research on Cylinder Thermal Insulation Films and Evaluation Analysis Techniques for Reducing Cooling Loss of Engines (1st Report)
-Design of Thermal Insulation Materials, Coating Methods, and Evaluation of Thermal Insulation Performance-

Kentaro Shinoda･Koichi Kinoshita･Shahien Yamada Mohammed･Abe Haruka･Megumi Akoshima･Eishi Kubota (AIST)･Takayuki Ito (JARI)

In order to improve the thermal efficiency of engines, it is important to reduce cooling loss, and the formation of heat-shielding films on the engine combustion chamber walls has attracted attention. In this study, we aim to establish material design, film formation, and evaluation methods to improve the performance of heat-shielding films by using a film formation technology using the hybrid aerosol deposition (HAD) method developed by AIST, and we will report on the progress of our research.

Research on Cylinder Thermal Insulation Films and Evaluation Analysis Techniques for Reducing Cooling Loss of Engines (2nd Report)
-Evaluation of Thermal Properties of Thermal barrier coating-

Haruka Abe･Kentaro Shinoda･Megumi Akoshima･Koichi Kinoshita･Shahien Yamada Mohammed･Eushi Kubota (AIST)

The HAD method, a film formation technology developed by AIST, is a solid-phase particle lamination method in which solid particles are sprayed and deposited without melting, and because low thermal conductivity is expected, it is expected to be used as a heat barrier film on engine combustion chamber walls, etc. In this study, we report on the evaluation of thermal conductivity properties by measuring thermal diffusivity, specific heat, and density using a sample formed on a metal substrate using ceramic fine particles by the HAD method.

Development of Thermal Barrier Coating Using Low Thermal Conductivity Material for Piston（2nd Report）

Ryoko Yamanoi･Kazuki Ogiwara･Teppei Tano･Shiori Yoda (ART metal manufacturing)

To improve the thermal efficiency of the engine, a thermal barrier coating on the piston top surface is being developed to reduce cooling losses. This composite coating consists of a thermal barrier layer made of porous particles and a surface sealing layer that prevents the intrusion of fuel and combustion gases. In this study, we clarified the impact of the coating method on coating strength and the　relationship between the substrate surface properties and adhesion strength for practical application.

Development of a High-Response Thermal Barrier Coating to Improve Fuel Efficiency and Combustion Stability in Gasoline Engines

Hiroya Okada･kazuma Kobayashi･Koji Kawashita (SUBARU)･katsuya Takaoka (Nittera)･Takeshi Tsuda (SUBARU)

A high-response thermal barrier coating has gotten attention as one of the items for improving engine cooling losses. In this report, we investigated the effects of applying a rare-earth composite oxide coating to the piston crown surface on thermal efficiency improvement and combustion stability during cold start and warm-up. Fuel economy improved by up to 1%, and in bench tests simulating cold start and warm-up conditions, the coefficient of variation of IMEP improved by approximately 10%.