| 摘要 |
PURPOSE: To achieve the accurate charge of a mold of a fin and to form the accurate contour of a tube by forming the fins one after another, after a former fin is completely formed, and providing a conveying face with the annular raised portions. CONSTITUTION: A compressed molten synthetic plastics material enters into an expansion space 38 on a first part of a molding space 27 through an exhaust gap 37, and the air is evacuated from an exhaust slit 29. When a half mold 2a further travels, an inside 61 of a mold of a fin is completely charged. In this stage, the expansion space 38 is charged. That is, only one fin is formed at one time. In a mold part for forming an outer wall of a tube, the molten matter 23a is abnormally cooled to be a concentrated fluid, and is forcibly conveyed by a conveying groove 62. A curved head part 45 determines an inner diameter of the tube 23 of the synthetic plastics material which is not yet cooled, and forms a smooth inner wall. Further the inner diameter of the tube 23 is accurately determined on a surface of a cooling bar. |
