During the machining process of speed variator-synchronizer binding annulus, the blank after being rolled is first cold extruded in precise mold inside an extruding machine to form the spline teeth and the interlocking angle at the end planes and then cold extruded in precise mold inside an extruding machine to form turned conic teeth. The teeth of the binding annulus need to further cutting and this results in saving in material and machining cost. The forming process is instantaneous and this results in high efficiency, low cost, no damage to metal flow line, raised comprehensive material performance, high product performance and quality for use in high-grade cars. |