Double closed hydraulic mould stand

A double closed hydraulic mould stand comprising:

• an up bottom plate (1) and an annular up mould plate (8) are connected through bolts, a down bottom plate (21) and an annular down mould plate (20) are connected through bolts, four symmetrically distributed guide sleeves (42) are fixed under the up mould plate (8), four symmetrically distributed guide columns (45) are fixed on the down mould plate (20), the guide columns (45) are sleeved by stop blocks (44), the guide sleeves (42) are on the guide columns (45) movably;
• an up piston cylinder is fixed on the up bottom plate (1), an up bed piece (11) and an up concave mould (16) are connected at a cover of the up piston cylinder in sequence, the up concave mould (16) is sleeved by an up concave mould prestressed ring (39) and is fixed on the up concave mould seat (15) through an up concave mould fixing ring (37), the up concave mould seat (15) is fixedly connected to the cover of the up piston cylinder, an up pin-lift (3), an up punch pin seat (4), and an up punch pin (38) in contact in sequence form an up piston, and the up piston slidingly fits an up gliding sleeve (40), the up bed piece (11), and the up concave mould (16) from top to bottom,
• a down piston cylinder is fixed on the down bottom plate (21), a down bed piece (31) and a down concave mould (33) are connected at a cover of the down piston cylinder in sequence, the down concave mould (33) is sleeved by a down concave mould prestressed ring (35) and fixed on an intermediate floating plate (18) through a down concave mould fixing ring (32), the intermediate floating plate (18) is fixedly connected to the cover of the down piston cylinder, a down pin-lift (24), a down punch pin seat (22), and a down punch pin (36) in contact in sequence form a down piston, and the down piston slidingly fits a gliding sleeve (25), the down bed piece (31), and the down concave mould (33) from top to bottom;
• a speed ratio mechanism is fixed between the up mould plate (8) and the down mould plate (20), the speed ratio mechanism comprises an up bearing support (12), an up hinge base (14), a down hinge base (19), a four-bar linkage (17), the intermediate floating plate (18), and small guide columns (49), two up bearing supports (12) are fixedly connected at two sides of the up mould plate (8) symmetrically, two down hinge bases (19) are fixed connected at corresponding positions at two sides of the down mould plate (20), the up bearing support (12) is connected to the up hinge base (14), the up hinge base (14) and the down hinge base (19) are connected through the four-bar linkage (17), the four symmetrically distributed small guide columns (49) are fixed under the intermediate floating plate (18), and the small guide columns (49) slidingly fit four symmetrically distributed small guide sleeves (47) disposed on the down mould plate (20) in a piston mode,
• an up cylinder bottom (6), an up annular piston (7), and an up cylinder cover (9) are disposed inside the up mould plate (8) in sequence and form an up piston cylinder, a circular slot is provided at a bottom surface of the annular up cylinder bottom (6) and connected to the up bottom plate (1) through bolts, an annular slot is provided at a top surface of the up annular piston (7) and connected to the up cylinder cover (9) through bolts, a cylindrical spring is installed between the annular slot of the up annular piston up and the circular slot of the up cylinder bottom (6), the up mould plate (8) serves as a cylinder body of the up piston cylinder and slidingly fits the up annular piston (7) and the up cylinder cover (9),
• the up concave mould seat (15) is sleeved by an up stop sleeve (13), and the up concave mould seat (15) and the up stop sleeve (13) slidingly fit each other, the up stop sleeve (13) is fixed on the up mould plate (8),
• a down cylinder bottom (26), a down annular piston (28), and a down cylinder cover (29) are disposed inside the down mould plate (20) in sequence and form a down piston cylinder, a circular slot is provided at a top surface of the annular down cylinder bottom (26) and connected with the down bottom plate (21) through bolts, an annular slot is provided at a bottom surface of the down annular piston (28) and connected with the down cylinder cover (29) through bolts, a cylindrical spring is installed between the annular slot of the down annular piston and the circular slot of the down cylinder bottom (26), the down mould plate (20) serves as a cylinder body of the down piston cylinder and slidingly fits the down annular piston (28) and the down cylinder cover (29), and four nitrogen gas springs (48) are symmetrically disposed on the down mould plate (20).