| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a dust seal structure for a valve stem in a rotary throttle valve carburetor preventing deterioration due to the effect of ultraviolet radiation, exhaust gas or the like, having excellent durability, requiring little maintenance and allowing further reduction in the mounting dimension in the height direction. <P>SOLUTION: The dust seal structure for the valve stem in the rotary throttle valve carburetor includes: a columnar throttle valve disposed perpendicularly with respect to an air intake passage in a carburetor body and having a throttle through-hole and a metering needle; and a fuel nozzle disposed on the central axis of the throttle valve, made to open into the throttle through-hole and having the metering needle inserted therein. The valve stem of the throttle valve having one end protruded from a shaft hole formed in a cover body of a valve hole in the carburetor body is rotated in accordance with the operation of an accelerator, whereby the throttle valve moves in the direction of a central axis thereof while rotated integrally so as to control an air flow rate and a fuel flow rate. A dust-proof member composed of a sealing ring is fitted between the valve stem and the shaft hole formed in the cover body. <P>COPYRIGHT: (C)2011,JPO&INPIT |
