Combustion type power tool having fin in low turbulent combustion region within combustion chamber

A combustion-type power tool comprising:

• a housing having one end and another end and defining a longitudinal direction;
• a head portion disposed at the one end and formed with a fuel passage;
• a cylinder disposed in and fixed to the housing;
• a push lever disposed at the another end and movable in the longitudinal direction when pressure contacting a workpiece;
• a piston reciprocally movable in the longitudinal direction and slidable relative to the cylinder, the piston dividing the cylinder into an upper space above the piston and a lower space below the piston;
• a combustion-chamber frame disposed in the housing and movable in the longitudinal direction in interlocking relation to the push lever, the combustion-chamber frame being abuttable on the head portion to provide a combustion chamber in cooperation with the head portion and the piston;
• a fuel supplying portion containing fuel and supplying the fuel into the combustion chamber through the fuel passage, thereby providing air-fuel mixture in the combustion chamber;
• a motor including a motor case disposed at the head portion and an output shaft extending from the motor case and protruding into the combustion chamber;
• a fan disposed in the combustion chamber and connected to the output shaft so as to be rotatable with the output shaft for promoting turbulent combustion of the air-fuel mixture, the fan and the combustion-chamber frame defining, within the combustion chamber, a high turbulent-combustion region in which the turbulent combustion is rapidly generated and a low turbulent-combustion region outside the high turbulent-combustion region;
• a fin having one shape and disposed at at least one of the combustion-chamber frame, the head portion, and the piston to protrude into the combustion chamber, an entirety of the fin being located within the low turbulent-combustion region;
• and
• another fin having another shape different from the one shape, at least part of the another fin being located in the high turbulent-combustion region.