| 摘要 |
PROBLEM TO BE SOLVED: To obtain a blowing sound for accurately judging the release of a wall surface due to a frequency analysis after the wall surface is blown and then a hammer immediately leaves the wall surface. SOLUTION: A roller 311 of a rod 31 is pushed up while it rotates on the outer periphery surface in involute surface shape of a cam 335 that rotates in the direction of an arrow R, thus causing the rod 31 to retreat. Also, a hammer 35 is allowed to retreat along with the rod 31 via a coil spring 36 for recovery. When the rod 31 reaches a stroke rear end position, the roller 311 deviates from a maximum diameter part 335a of the cam 335 and the rod 31 and the hammer 35 speedily advance due to the extension of a coil spring 34 for blowing being compressed. The hammer 35 advances due to inertia even after the rod 31 stops and blows a wall surface W to be diagnosed. The hammer 35 leaves the wall surface W to be diagnosed due to the pull biasing force of the coil spring 36 for recovery immediately after blowing. |
