Manufacturing process of vehicle safety belt shaft

The invention discloses a manufacturing process of a vehicle safety belt shaft. The manufacturing process comprises the following steps that blanking is carried out, head pre forming is carried out, specifically, impact is carried out under the combined action of the concave head punching die and the flat head main die; head forming is carried out, specifically, impact is carried out again under the combined action of the punching die and the main die, and thus a head of a product is formed; the diameter reducing of a rod part is carried out, specifically, impact is carried out under the combined action of the punching die, a push pipe and a closed bundle flat main die, and thus the rod part of the product is formed; flange forming is carried out, specifically, impact is carried out under the combined action of a flat hole punching die and a concave ring main die, and thus a flange part of the product is formed; an inner hole is impacted, specifically, impact is carried out under the combined action of the flat hole punching die, a movable inner main die and an hole extruding rod, and thus an inner hole is formed in the rod part of the product; and appearance trimming is carried out, impact is carried out under the combined action of a titanium-plated trimming die and a concave head inner main die, and thus a notch is formed in the flange part of the product. According to the product formed through the above manufacturing process, the surface roughness is greatly reduced, and the phenomenon that a safety belt generates jerking during the use process can be reduced or even avoided.