Rotary carburetor

A rotary carburetor, comprising

• a columnar throttle valve disposed orthogonally to the intake passage of the main section of the carburetor and provided with a throttle through-hole and a metering needle;
• a fuel nozzle disposed on the center axis line of the throttle valve, the metering needle being inserted into the fuel nozzle;
• and
• a cam mechanism for causing the throttle valve to move in the direction of a valve stem extending from the center of the top surface of the throttle valve and being caused to rotate in accordance with the throttle operation, whereby the throttle valve is moved by the cam mechanism in the direction of the valve stem while rotating integrally with the valve stem to adjust the air flow rate and the fuel flow rate;
• wherein the cam mechanism includes:
• a cam groove provided with a cam surface so as to gradually deepen in the direction of rotation in a designated range on the external peripheral side of the bottom surface of the throttle valve;
• and
• a support pin for supporting the throttle valve from the bottom surface, the support pin being disposed between the cam surface and the bottom surface of a columnar throttle valve chamber and rotatably provided with the throttle valve.