Combustion-type power tool having ignition proof arrangement

摘要

A spark (53) is shot between an ignition point of an ignition plug (50) and an ignition ground (51). The spark is shot from an acute corner (61) of a core (60) of the ignition plug. A tip end (61) of the core has an acute angle of not more than 45 degrees. With this arrangement, an emitting point of the spark can be concentrated to the tip end of the core. In order to reduce a thermal capacity of the ignition ground so as to enhance ignitability, a side (55) opposite to the spark seating face of the ignition ground is tapered to provide an angle (±1). Further, the ignition ground has an apex end providing an angle (²1) which is not more than 45 degrees. Because of the apex portion, thermal capacity of the ignition ground can be reduced and an acute angle can be realized to concentrate spark receiving point at the apex portion. As a result, ignitability can be enhanced.