Extrusionsmatrize für Mehrkanalrohre und Mehrkanalrohre hergestellt mit der Matrize

摘要

A multi-hole tube extrusion die (9 :109) comprises a female mold die having a flat opening (90a :190a) and mandrel (9b :109b) having comb-teeth-like molding portions (90b, 91b :190b, 191b, 192b) arranged in the opening. A heated material is extruded between the female mold die opening (90a :190a) and the comb-teeth-like molding portions (90b, 91b :190b, 101b, 192b) of the mandrel to form a tube (2 :102 :202 :302 :402) having a multiplicity of holes (20a, 20b :120a, 120b, 120c :220 :320 :420). An interval (ta) between each of the comb-teeth-like molding portions (90b :190b) at the opposite ends of the mandrel and the comb-teeth-like molding portion (91b :191b) adjacent to the outermost comb-teeth-like molding portion is set to be smaller than an interval (T) between the female mold die opening and each of the outermost comb-teeth-like molding portions and to be larger than an interval (tb) between adjacent ones of the other comb-teeth-like molding portions (91b :191b, 192b). Additionally, the outermost comb-teeth-like molding portions (90b :190b) are set to be larger in their thickness (wa) the other comb-teeth-like molding portions (91b :191b, 192b). Therefore, a lateral pressure difference acting on each of the outermost comb-teeth-like molding portions due to flows of the material is reduced, and the rigidity of the outermost comb-teeth-like molding portions is increased, thereby preventing deformation of the die and enabling prolongation of the life of the die as well as higher accurate extrusion.