| 摘要 |
A driving piston 4 is provided slidably up and down in a driving cylinder 3 arranged in a tool body 1. By moving a movable sleeve 10 provided at the upper portion of the driving cylinder 3 up and down, the movable sleeve 10 is brought into contact with and separated from the driving cylinder 3 and a cylinder head 8 provided above the driving cylinder 3, whereby a combustion chamber can be opened and closed. Mixture gas obtained by stirring and mixing combustible gas and air together in the combustion chamber by a fan 16 is ignited by an ignition plug 15 disposed at the cylinder head 8 and explosively combusted. By this high-pressure combustion gas, the driving piston 4 is impulsively driven, and a driver 5 coupled to the lower surface side of the driving piston drives nails. Between an exposed base portion of a center electrode of the ignition plug 15 which is exposed to the outside facedown and a leading end of the center electrode, there is provided a stagnation part 25 which stagnates temporarily a residue remaining after the combustion of the mixture gas. |
