Low-pressure aluminum casting mold and low-pressure aluminum casting process for motor rotor

A low-pressure aluminum casting process for a motor rotor, the process including the following steps:

• a) cold lamination:
• sequentially stacking a plurality of rotor laminations on a dummy shaft (2) of a low-pressure aluminum casting mold, applying a lamination pressure to a pressing cover (8-1) of a first pressing device (8) by an oil press, thereby laminating the plurality of rotor laminations to form a rotor core (1), wherein tonnage of the oil press is 30-50 T and the lamination pressure exerted by the oil press is 2.5-3.0 MPa;
• after a whole height of the rotor core (1) reaches a first specified length, the rotor core (1) is fastened to the dummy shaft (2) by the pressing cover (8-1) and an eyebolt (8-2) of the first pressing device (8);
• b) heating of the rotor core:
• transporting the rotor core (1) fastened to the dummy shaft (2) by the first pressing device (8) in step a) to a heating furnace for heating, wherein, firstly the rotor core (1) is heated at a temperature rise rate of 70-90° C./h for 1 hour and then kept warm for 1 hour, then the rotor core (1) is heated at a temperature rise rate of 70-90° C./h for 1 hour and then kept warm for 1 hour, finally the rotor core (1) is heated at a temperature rise rate of 80-100° C./h for 1 hour and then kept warm for 5 hours;
• c) mold preparation:
• assembling a lower backing plate (5) and a lower mold (6), placing a diverter (7) on the lower mold (6), installing a clamping plate (9-2) in a clamping slot (5-1) of the lower backing plate (5), and vertically setting a pull rod (9-1) in place;
• d) hot lamination:
• lifting the rotor core (1) heated in step b) out of the heating furnace, placing a lower cover (2-3) of the dummy shaft (2) on the diverter (7), placing an upper backing plate (3) and an upper mold (4) on the rotor core (1), passing a hold-down through hole (3-1) on the upper backing plate (3) through an upper end of the pull rod (9-1), preliminarily fastening the rotor core (1) by a hold-down nut (9-3), and starting the oil press to continuously laminate the rotor core (1) until an overall height of the rotor core (1) reaches a second specified length, and then tightening the hold-down nut (9-3) again;
• and
• e) low-pressure casting:
• lifting a whole mold fastened in step d) to a low-pressure aluminum casting machine for aluminum casting, and completing low-pressure aluminum casting of the motor rotor.