Machining process for engagement sleeve hollow pipe and machining die

The invention discloses a machining die for an engagement sleeve hollow pipe. The machining die comprises a pre-forging die and a finish-forging die; the pre-forging die comprises an upper pre-forging chambering die and a lower pre-forging chambering die; the upper pre-forging chambering die comprises an inverted circular truncated cone used for chambering; a circular groove which is identical to a blank in diameter is formed in the lower pre-forging chambering die; the finish-forging die comprises an upper finish-forging tooth die, a lower finish-forging tooth die and a finish-forging die jacking pillar; a forging cavity formed under the condition that the upper finish-forging tooth die and the lower finish-forging tooth die are closed is identical to the engagement sleeve hollow pipe in tooth form; the finish-forging die jacking pillar is used for supporting the chambered blank. By applying the machining die for the engagement sleeve hollow pipe, the bending strength, contact fatigue strength and shock resistance of the tooth form are high, and the performance is excellent; the abrasion resistance of the tooth form is good, and the meshing stability is high. The subsequent inner hole machining allowance of the forged blank is small, hole materials are saved, and the production efficiency and material utilization rate are improved. The invention further discloses a machining process of the engagement sleeve hollow pipe.