| 摘要 |
PROBLEM TO BE SOLVED: To provide a large output by permitting only flow directed to a reduced- diameter main combustion chamber when an expanded-diameter piston having a reduced-diameter piston protruded from the center of a bowl-like recess is in a specified position during a heating stroke and injecting thermal energy produced by combustion in the reduced-diameter main combustion chamber to an expanded-diameter main combustion chamber. SOLUTION: A reduced-diametral piston having a tapered root part 2 is protruded nearly in the center of bowl-like recesses 1 in both ends of a double-head expanded- diametral piston. Then, by reciprocating the double-head expanded-diametral piston in a cylinder, combustion is performed while performing normal exhaustion and scavenging around left and right dead centers. In this case, by the reduced-diametral piston having a noise reducing groove 15 extended obliquely toward a motion direction around the tapered root part 2, a flange-like recessed and projecting part 6 and the wide projecting part of a tip, isolation of a reduced-diametral combustion chamber is started in a compression strohe after the scavenging, then air compressed in an expanded- combustion chamber is injected through an air passage 4 including a check valve 3 and an oblique air passage 14 to the reduced-diametral main combustion chamber and mixed with injection fuel from an injection device 5 to perform combustion. |
