Exhaust apparatus for small-sized engine

Abstract

An exhaust device (90) for a small engine (14) includes a muffler (92) having an exhaust portion for discharging exhaust gases from an exhaust pipe (91). The tubular member (121) is mounted on the exhaust portion of the muffler. Within the tubular component, a filter (122) made of metal fibers is provided for reducing exhaust noise.

Description

technical field [0001] The present invention relates to an exhaust device for a small engine used as a power source for a portable working machine such as a blower or a lawnmower. Background technique [0002] An exhaust device disclosed in, for example, JP-A-11-13452 includes an exhaust pipe connected to a small engine and a box-shaped small muffler mounted on a distal end portion of the exhaust pipe. [0003] Fig. 11 of this specification shows the exhaust device disclosed in the above-mentioned document. In FIG. 11, reference numeral 230 denotes an exhaust device, which includes an exhaust pipe 232 extending from an engine 231, a box-shaped muffler 233 mounted on the exhaust pipe 232, and a A spark arrestor 234 that prevents sparks contained in the high temperature exhaust gas from entering the air. [0004] The muffler 233 includes a first expansion chamber 235 communicated with the exhaust pipe 232, a second expansion chamber 237 communicated with the first expansion ...

AI Technical Summary

Problems solved by technology

Therefore, it is impractical to narrow the exhaust passage 241 or further reduce the number of exhaust holes 242 to further reduce the exhaust noise.

If the exhaust passage 241 is widened or the number of exhaust holes 242 is increased, the back pressure can be reduced, thereby preventing the muffler 233 from being overheated, but sufficient reduction in exhaust noise cannot be achieved

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