As engines become more powerful, the maximum pressure in the cylinder and temperature changes around the cylinder have been increasing, and the risk of a drop in the cylinder head gas sealing contact pressure during operation has risen. As such, when evaluating gas leakage, it has become necessary to consider how cylinder head gas sealings are operated. To evaluate gas sealing performance during operation, it is necessary to continuously measure the gas sealing contact pressure, including its change over time during operation. However, due to the difficulty of measurement, there is no other way to evaluate gas sealing performance other than long-term operational tests. Therefore, we developed a method to estimate sealing contact pressure from the measured strain of the tightened object near the sealing, and applied this method to a gas sealing of a cylinder head of an actual engine, and found that this method can be a useful measurement method as a result.
