Double-sided drilling fixture for die-forged pistons and double-sided drilling process thereof

A double-sided drilling fixture for die-forged pistons, comprising a fixture base assembly, an upper load-resisting assembly and a lower expansion-resisting assembly, wherein the upper load-resisting assembly is installed on the fixture base assembly and disposed above the a die-forged piston (15);

• a fixation base (13) is installed above the fixture base assembly, characterized in that:
• the fixation base (13) has an upper surface shape same as internal surface shape of the die-forged piston (15);
• the die-forged piston (15) is sleeved on the fixation base (13);
• and
• the lower expansion-resisting assembly comprises a lower hydraulic cylinder (2) installed on the fixture base assembly with a lower piston rod (3) facing the die-forged piston (15), the fixation base (13) is provided with an expansion block (28), a front expansion pin (27) and a rear expansion pin (31) therein, the front expansion pin (27) and the rear expansion pin (31) are located on a same transverse section of the fixation base (13), and forms sliding engagement with the fixation base (13), the expansion block (28) is installed at a longitudinal center of the fixation base (13) and forms sliding engagement with the fixation base (13), the front end of the expansion block (28) is of a cone frustum shape, the rear end of the expansion block (28) is installed on the lower piston rod (3), the rear ends of the front expansion pin (27) and the rear expansion pin (31) are pressed against narrowest part of the cone frustum at the front end of the expansion block (28), wherein when the lower piston rod (3) moves to its maximum load range, the front end of the expansion block (28) moves upward to squeeze the front ends of the front expansion pin (27) and the rear expansion pin (31) onto the inner wall of the die-forged piston (15).