BREATHER STRUCTURE IN FOUR-CYCLE ENGINE FOR WORK MACHINES

摘要

In order to prevent lubricating oil from entering an intake system when an engine body is tilted downward while avoiding any increase in the engine dimensions, the engine body has first and second breather chambers, first an d second through passages for providing communication between a crank chamber and the first and second breather chambers, respectively, and a communicating passage for providing communication between the first and second breather chambers. The second breather chamber is connected to the intake system via a guide pipe, an end of the second through passage that opens inside the crank chamber is positioned above the oil surface inside th e crank chamber when the engine is tilted downward, and the route from the fir st through passage to the communicating passage via the first breather chamber is shaped so as to prevent the lubricating oil inside the crank chamber from entering the communicating passage.