Die structure capable of punching double holes on rectangular pipe

The utility model provides a die structure capable of punching double holes on a rectangular pipe, which mainly comprises a lower template, a lower fixing plate, an upper template, an upper fixing plate, a die shank, a convex die, a concave die I, an inner core positioning block and a concave die II, wherein the convex die is assembled on the upper fixing plate in a pressed manner; the upper fixing plate is fastened on the upper template through a screw and a cylindrical pin; the upper half working part of the die is installed on a sliding block of a punching machine through the die shank installed on the upper template; the concave die I is assembled on the inner core positioning block in a pressed manner; the inner core positioning block is fixed on the lower fixing plate through a screw and a cylindrical pin; the concave die II is assembled on the lower fixing plate in a pressed manner; the lower fixing plate is installed on the lower template; the lower half working part of the die is fixed on a worktable of the punching machine through the lower template; the inner core positioning block is of stepped shape; and the height difference of steps of the inner core positioning block is the sum of the wall thickness and a gap value of 0.2mm. As the die structure is adopted, the deformation of a pipe wall of a rectangular pipe fitting during the punching process due to a force is reduced, the coaxiality of through holes on the rectangular pipe fitting is ensured, and the product quality is ensured.