Hollow profile-manufacturing extrusion die and hollow profile

Abstract

A hollow profile-manufacturing extrusion die includes a mandrel that molds an inner peripheral surface of a hollow part, and bridges for supporting the mandrel. The mandrel is disposed so as to correspond to a die hole that molds an outer peripheral surface of the hollow profile. The bridges are disposed at positions corresponding to between the hollow part and side surfaces in the hollow profile, and are not present at positions corresponding to between the hollow part and a lower surface.

What is claimed is: 
     
         1 . A hollow profile-manufacturing extrusion die for manufacturing a hollow profile of which, in an outer peripheral surface, a dimension between side surfaces is longer than a dimension between an upper surface and a lower surface, and which has a hollow part continuing in a longitudinal direction on a lower side relative to a middle position in an up-down direction, the hollow profile-manufacturing extrusion die comprising:
 a mandrel that molds an inner peripheral surface of the hollow part, the mandrel being disposed so as to correspond to a die hole that molds the outer peripheral surface of the hollow profile; and   bridges for supporting the mandrel, wherein   the bridges are disposed at positions corresponding to between the hollow part and the side surfaces in the hollow profile, and are not present at positions corresponding to between the hollow part and the lower surface.   
     
     
         2 . The hollow profile-manufacturing extrusion die according to  claim 1 , wherein the bridges are disposed only at positions corresponding to a middle part and the side surfaces in the hollow profile. 
     
     
         3 . The hollow profile-manufacturing extrusion die according to  claim 1 , wherein a bridge that is disposed at a position corresponding to between one side surface of the side surfaces and the hollow part and a bridge that is disposed at a position corresponding to between the other side surface and the hollow part are disposed in a straight line as seen from an extrusion direction. 
     
     
         4 . A hollow profile composed of an extruded profile of which, in an outer peripheral surface, a dimension between side surfaces is longer than a dimension between an upper surface and a lower surface, and which has a hollow part continuing in a longitudinal direction on a lower side relative to a middle position in an up-down direction, wherein weld lines are formed at positions corresponding to between the hollow part and the side surfaces, and the weld lines are not present at positions corresponding to between the hollow part and the lower surface. 
     
     
         5 . The hollow profile according to  claim 4 , wherein the hollow part is provided by a circular hole with a diameter of 10 mm or smaller. 
     
     
         6 . The hollow profile according to  claim 4 , wherein a dimension from a center of the hollow part to the lower surface is set to be equal to or smaller than 1/2 of a dimension from the center of the hollow part to the upper surface. 
     
     
         7 . A manifold produced using the hollow profile according to  claim 4 , wherein a recessed part is provided in the upper surface of the hollow profile, and a communication hole communicating with the hollow part is provided in a bottom wall of the recessed part.