Method for forming tube with high internal pressure and low external pressure, and forming machine
US11338345B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 2019 |
| Grant date | May 24, 2022 |
| Priority date | — |
| Expiry date | Mar 3, 2039 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D26/047
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Disclosed is a method for forming a tube with high internal pressure and low external pressure. The method comprises: putting a tube to be formed into a cavity, such that a bulging area (15) is formed between the tube to be formed and an inner wall of the cavity; continuously injecting a low-pressure fluid into the bulging area, and then injecting a high-pressure fluid into the interior of the tube to be formed, the high-pressure fluid creating a pressure on an outer wall of the tube to be formed such that the tube to be formed starts to expand to the bulging area; stopping the supply of the low-pressure fluid when the tube is bulged to conform to the inner wall of the cavity; and taking the formed tube out to complete a working cycle. Further disclosed is a forming machine for forming a tube according to the above method. According to the machine for forming a tube with high internal pressure and low external pressure, a mold body (1) is provided with a first through hole (13) and a second through hole (14) for circulating a low-pressure fluid into and out of a bulging area, so as to create a certain pressure P1 on the tube and ensure uniform bulging of the entire tube, thereby ac…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.