| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic forming method, which is used when performing hydraulic forming such as hydroforming by using a forming material having a protrusion part that protrudes upward, capable of surely eliminating gas in a space inside the material, thereby surely preventing gas such as air from remaining in a space inside the protrusion part of the forming material and suppressing a forming defect due to the residual gas from occurring.SOLUTION: In a hydraulic forming method, a hollow tube which opens to an inside space of a protrusion part inside a material is inserted from the outside of the material into the inside thereof, and when filling a pressurizing liquid inside the material, air inside the protrusion part inside the material is discharged to the outside of the material through the tube. Further, a flexible tube is used as the above tube, which has an elastic member attached thereto for pressing a tip end of the tube toward an inner surface of the protrusion part in the material. As the inside of the material is filled with the pressurizing liquid, the tip end part of the tube is formed so as to float in an approaching direction to an upper bottom surface of the protrusion part. |
