PURPOSE: To apply compression residual stress, increase the strength of a propeller and improve the reliability by pressure-bonding or pressure-sticking the defective cast, with a pressurizer, on a predetermined area of a propeller blade advance face where break accidents of a propeller material are concentrated.
CONSTITUTION: In order to increase the strength of a propeller at the vicinity S of the end section of a boss root joint (r) on the advance face F side where break accidents of a propeller material are concentrated, i.e., the area portion with 0.25RW0.45R against the propeller blade radius R, the said portion is surface-machined at a normal temperature with a pressurizer. Thereby, the defective cast is pressure-bonded or pressure-stuck to apply compression residual stress. When a flat-top chisel 2 with a diameter (d) driven pneumatically or hydraulically is used as the pressurizer, for example, strokes are applied while it is rotated at a diameter of about 1.0d, and it is shifted at a speed of about 0.25d per rotation. Then, after one line of stroke-machining is completed, it is moved for the machining of the next line with a feed width of about 1.3d to continue the work.
YAMAMOTO SUSUMU
SASAKI YOSHIO
NAKANO MOTOHIRO
MORIYA KIYOSHI
| JPS5284700A | 1977-07-14 |