Alloy injection head and die casting machine thereof

The invention provides an alloy injection head and a die casting machine thereof.The injection head comprises a fixed head end and a fixed tail end, the fixed head end and the fixed tail end are fixedly connected through a plurality of sliding rods arranged in an annular array, and an expansion ring piece is further installed between a translation adjusting push plate and the adjacent fixed head end or fixed tail end; the displacement sliding mechanism pushes the translation adjusting push plates on the two sides to move towards each other or away from each other so as to adjust the compression curvature of the expansion ring piece, the expansion ring piece, the translation adjusting push plates, the fixed tail end and the charging barrel define an external maintenance space, and an external maintenance medium injection pump is communicated with the external maintenance space. According to the device, the compression curvature of the expansion ring piece can be actively adjusted, abrasion of the injection hea