Development of Intercooler Hose for Future Engine

Current intercooler hoses, which are made from fluorocarbon rubber (FKM) and silicone rubber (VMQ) exhibit high heat resistance and durability. However, they will be used in more severe use environments, and there is a risk of problems arising with their current material composition. This investigation into issues concerning intercooler hoses in future engines found that FKM mechanical properties were insufficient under high temperature environments. In this research, efforts to improve the mechanical properties of FKM focused on the low durability of the internal FKM crosslinking points as the cause of this insufficiency. The current crosslinking method has excellent acid resistance and cannot be modified. An effective improvement the properties was therefore sought by adding a new distinct crosslinking network while preserving the current level of acid resistance of the existing network. Carbon black gel was used as a reinforcing agent to form the new network. Polymer types and blending were adjusted to achieve the target values and develop a new FKM, which was used to make a prototype hose and confirmed to be free of problems through bench tests. The following points were made clear in this research. The material properties of the inner FKM layer when heated are insufficient to meet the environmental requirements of future engines. Efforts to improve mechanical properties when heated while maintaining the environmental resistance and formability of the material led to achieving the development targets by reinforcing the network through the application of carbon black gel.