PURPOSE: To make possible the automatic fine adjustment of the tool diameter correspondingly to the working error of the low hole, by settling through the axial movement the working diameter of the mandrel insertd into the cylindrical casing whose tip is provided with taper rolls at a uniform pitch.
CONSTITUTION: In the case of burnishing the lower hole C of the material B to be worked, being clamped by the holder A, the entire apparatus is moved down with the downward movement of the spindle 14; when the stopper 26 strikes the holder A, the downward movement of the cylinder 20 is stopped. Under this condition, the position of the stopper 26 is settled so as to make the face pressure given to the lower hole C of the roller 11 to be lower than the required face pressure, even though the manufacturing error is taken into consideration. Next, while the fluid of the cylindrical casing 32 is being discharged through the path 23 at a constant rate, the sleeve 30 together with the spindle 14 are moved downward for moving the mandrel 12 forward, and for expanding the roller 11 outward. Then, when the thrust force of the mandrel 12 becomes constant, the fluid discharge through the path 23 is stopped, and the mandrel 12 is stopped there. Hereupon, the roller 11 is impressing a constant face pressure on the lower hole C independently of its diameter error.
KAJITANI HAJIME
URAKAWA NOBUO
NAKAGAMI MASAFUMI
OOHASHI TAKAO
TANAKA ISAMU
| JPS5021315A | 1975-03-06 |