| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine capable of reducing a pumping loss accompanying a volume change of a back chamber of a piston without complicating the structure thereof. <P>SOLUTION: The back chamber 29A formed to be sealed in a back part of the piston 25, which is to be slidably fitted in a cylinder 24 of the internal combustion engine, is partitioned, and the air and the oil inside of the back chamber 29A are discharged into an oil pan 15 by a negative pressure pump PA structured of a balancer weight housing chamber 17a and a balancer weight 18c of a secondary balancer device 16. With this structure, a pumping loss of the internal combustion engine can be reduced by restricting a pressure rise of the back chamber 29A. Further, since the negative pressure pump PA is driven, being connected to a crankshaft 20, the timing of sucking air and oil inside of the back chamber 29A by the negative pressure pump PA can be automatically synchronized relative to the lowering of the piston 25, and a control device for controlling the timing of sucking air and oil is unnecessary, and the structure of the internal combustion engine can be simplified. <P>COPYRIGHT: (C)2012,JPO&INPIT |
