초록 ▼

A cold rolling method and apparatus for forming an annular workpiece (10) with an outer surface (11) having a given contour and an inner surface (12) having a given contour, starting from an annular blank. A rotatable forming mandrel (21) has a working surface (21a) with a contour corresponding to t

A cold rolling method and apparatus for forming an annular workpiece (10) with an outer surface (11) having a given contour and an inner surface (12) having a given contour, starting from an annular blank. A rotatable forming mandrel (21) has a working surface (21a) with a contour corresponding to that of inner surface (12) to be formed. A forming die (51) has a cavity (52) with an inner working surface (53) in form of a surface of revolution corresponding to the outer surface (11) to be formed.

대표청구항 ▼

1. A cold rolling apparatus for forming an annular piece (10) with an outer surface (11) having a given contour and an inner surface (12) having a given contour, starting from an annular blank, the apparatus comprising:a forming mandrel (21) rotatable about a first axis (X1), the mandrel having a wo

1. A cold rolling apparatus for forming an annular piece (10) with an outer surface (11) having a given contour and an inner surface (12) having a given contour, starting from an annular blank, the apparatus comprising:a forming mandrel (21) rotatable about a first axis (X1), the mandrel having a working surface (21a) with a contour corresponding to that of the inner surface (12) to be formed,a forming die (51) rotatable about a second axis (X2) parallel to the first axis (X1), the die having a cavity (52) with an inner working surface (53a) in form of a surface of revolution corresponding to the outer surface (11) to be formed,first motor means (70, 72) for provoking rotation of the mandrel (21) and the die (51) about the respective axes (X1, X2),second motor means for varying in controlled manner the distance between the first (X1) and the second (X2) axes, so as to radially compress the workpiece (10) between the working surfaces (21a, 53a) of the mandrel (21) and the die (51);characterised in that the apparatus further comprises third motor means (43) for varying the relative axial distance between the mandrel (21) and the die (51), andwherein the mandrel (21) and an intermediate roller (31) are mounted on a plate (41) slidable along axial guide means (42) between a first, axially retracted loading position and a second, working position axially advanced towards the die (51), wherein in said second position the intermediate roller (31) is transversally interposed between and in contact with the mandrel (21) on one side, and a reaction assembly (90) provided with at least one idle roller (91, 92) on the other side.2. The apparatus of claim 1, wherein the reaction assembly (90) comprises a pair of axial reaction rollers (91, 92) located respectively above (91) and underneath (92) the horizontal plane in which the axis (X3) of the intermediate roller (31) lies.3. The apparatus of claim 2, wherein the axial reaction rollers (91, 92) are idly mounted on a centering support (93) hinged to a fixed supporting structure (38) about a longitudinal axis (X6) located at a height intermediate between those of the axial reaction rollers (91, 92).4. The apparatus of claim 1, wherein the mandrel (21) and the intermediate roller (31) are mounted in respective journal boxes (23, 33) secured to the plate (41) so as to oscillate about respective longitudinal axes (X4, X5).5. The apparatus of claim 1, comprising latch means (39) adapted for engaging corresponding seats (40) of the longitudinally slidable plate (41) so as to lock the plate (41) in said second advanced or working position.6. The apparatus of claim 1, wherein the mandrel (21) is operatively associated with fourth motor means (37) for provoking a rotation of the mandrel in the same direction of rotation imparted to the mandrel during operation.