Internal combustion engine with pre-chamber

An internal combustion engine with a pre-chamber provided inside a main combustion chamber, the pre-chamber comprising:

• an ignition plug attached to a ceiling part of the main combustion chamber and configured to ignite a mixture gas containing a fuel component and air;
• and
• a casing provided to the ceiling part so as to cover the ignition plug, the casing isolating an internal space formed therein from the main combustion chamber,
• wherein the main combustion chamber is connected to an intake port and an exhaust port, and intake air flowing into the main combustion chamber through the intake port forms a tumble flow of the mixture gas inside the main combustion chamber,
• wherein a plurality of communicating holes communicating the internal space of the casing with the main combustion chamber are formed in the casing, the plurality of communicating holes include a first communicating hole opening to the intake port side in a radial direction of the main combustion chamber, and a second communicating hole opening to the exhaust port side,
• wherein the tumble flow flowing into the pre-chamber through the first communicating hole forms in the pre-chamber a vortex flowing in the opposite direction from the tumble flow, and
• wherein the main combustion chamber is provided with a structure configured to suppress a flow opposing the vortex inside the pre-chamber flowing into the pre-chamber through the second communicating hole.