Patent ID: 11858023
Assignee: NORTH UNIVERSITY OF CHINA
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 0:
1. A rotary extrusion forming method for a cabin section workpiece,
comprising a male die, a female die, an upper die assembly comprising (a) a push-pull device that comprises a left half male die retainer, a left retainer hydraulic cylinder, a right half male die retainer and a right retainer hydraulic cylinder, (b) an upper die base, and (c) a press connector, a lower die base and a rotation driving device; the male die is arranged on the upper die assembly which can drive the male die to move in the vertical and horizontal directions, and the female die is arranged on the lower die base in such a manner that the female die can rotate about a vertical axis; the rotation driving device is in drive connection with the female die and can drive the female die to rotate about the vertical axis; the method further comprises the following steps of:
S1: preparing a hollow truncated cone-shaped blank with openings at both ends;
S2: heating the prepared blank to a molding temperature and holding, and preheating the female die and the male die to above the molding temperature and holding;
S3: assembling the upper die assembly on a press;
S4: applying lubricant on the female die and the male die, and placing and fixing the blank into a die cavity of the female die;
S5: starting up the rotation driving device to drive the female die to rotate on the lower die base, so that the female die drives the blank to rotate; starting up the press to make the male die move down to a machining position of the blank in the die cavity through the upper die assembly, and machining inner side walls of the blank; and
S6: after the blank is formed by machining, making the male die move up by the press to a preset position through the upper die assembly,
in S5 to S6, machining the inner side walls of the blank by the male die specifically comprises steps as follows:
when the upper die base drives the left half male die and the right half male die to move down to the machining position of the blank in the die cavity, the press connector drives the wedge to move down, and the push-pull device drives the left half male die and the right half male die to feed separately to directly extrude the inner side wall of the blank;
after the left half male die and the right half male die extrude the inner side wall of the blank to a first forming position, the wedge remains motionless; after the upper die base drives the left half male die and the right half male die to move up along the inclined surfaces on the left side and right side of the wedge, respectively, to a second forming position, the press connector drives the wedge to move up; and after the push-pull device drives the left half male die and the right half male die to close and to move to a designated position, the upper die base drives the left half male die and the right half male die to move up to the preset position, thus extruding the blank into the cabin section workpiece of an irregularly-shaped thin-walled structure with a non-straight wall face as its machining face and with the openings at the both ends; and
an inclined surface is provided on one side of the left half male die while an inclined surface is provided on one side of the right half male die; the inclined surface on the left side of the wedge matches with the inclined surface of the left half male die and that on the right side of the wedge matches with the inclined surface of the right half male die.