Two-stroke internal combustion engine and engine working machine

A two-stroke internal combustion engine, comprising:

• a cylinder, which defines a combustion chamber, and has an exhaust port;
• an ignition device configured to ignite an air-fuel mixture in the combustion chamber;
• a piston configured to reciprocate inside the cylinder through combustion and expansion that occur in the combustion chamber;
• a crank chamber communicating with an interior of the cylinder;
• a crankshaft, which is disposed in the crank chamber, and is operationally coupled to the piston;
• a fuel injection valve configured to inject a fuel into the crank chamber;
• an intake passage configured to allow only air to be sucked thereinto under a negative pressure generated when the piston is actuated;
• and
• a scavenging passage that allows communication between the crank chamber and the combustion chamber,
• wherein air passing through the intake passage is introduced into the scavenging passage, and air stagnant in the scavenging passage at end of air suction contributes to scavenging.