The device (1) has an end section (3) including a flexible hollow body (2) containing pressurized fluid, where the hollow body is acted upon with pressure The end section is arranged in a region of a bending portion of a pipe during a bending operation The end section is partly surrounded by a reinforcing device (7) on an outer side A diameter of the end section is partially variable The end section includes an inlet guide (8) representing a pressure tight closure of the hollow body A module device inserts the end section into the pipe Independent claims are also included for the following: (1) a tube bending fixture comprising a pipe stabilization device (2) a bending method

Pipe stabilization device i.e. hydraulic bending arbor, for stabilization of bending portion of e.g. round pipe during bending operation for transformation of pipe, has end section including flexible hollow body containing pressurized fluid

Une machine de cintrage d'au moins une canalisation cylindrique longitudinale creuse, la machine comportant au moins un module de deformation comportant une enclume de cintrage, une enclume de serrage configuree pour contraindre une portion de la canalisation contre l'enclume de cintrage et une enclume de pression configuree pour deformer ladite portion lors de son deplacement par l'enclume de cintrage et l'enclume de serrage, la machine de cintrage comportant au moins un mandrin (4), configure pour s'etendre a l'interieur de la portion de la canalisation a cintrer, le mandrin (4) comportant au moins une enveloppe gonflable (40) dont la section est inferieure a la section de la canalisation a l'etat degonfle, l'enveloppe gonflable (40) etant configuree pour exercer un effort sur la surface interieure de la canalisation a l'etat gonfle pour maintenir sa section au cours du cintrage.

Machine de cintrage comportant un mandrin gonflable et procede de cintrage

PURPOSE:To restrain generation of sectional deformations and wrinkles and to improve the quality of bent products by inserting a flexible elastic tube into a predetermined bending part of a pipe to be bent and bending the pipe with an incompressible fluid pressurized to fill the elastic tube. CONSTITUTION:A pipe 3 is set on a fixing table 4 with a pressing die 2; a flexible elastic tube 8 which is freely expansible in the radial direction and is provided with a blocking member blocks axial elongation is inserted into the predetermined bending part of the pipe 3 with the tube 8 being in a contracted condition. Then, the tube 8 is filled with an incompressible fluid from an introduction pipe 11 so that the tube 8 is in contact with the inner surface of the predetermined part. Next, a rotation table 6 is turned and the tube 8 is moved in proportion to the turning of the table 6. The predetermined bending part of the pipe 3 is bent along a die 5 by the turning of the table 6 and tends to be flat, but the tendency is restrained from the inside of the pipe 3 by the tube 8 and axial elongation of the pipe 3 is also restrained by the elongation blocking member.

Bending method for tube

PURPOSE:To obtain the title cylindrical blank having fine crystal grains and suitable to spinning by hot-extruding a maraging billet, cold-drawing the material at a specified draft, and then applying solution treatment. CONSTITUTION:A maraging billet of Ni-Co-Mo-Ti, etc., is hot-extruded, and then air-cooled to room temp. The number of the crystal grain size is then measured. The measured value is substituted for the G.S in the inequality to obtain the draft (Rd), cold drawing is carried out at the draft, and solution treatment is then applied. The Cold drawing consists of spreading, reduction, and madrel drawing. By this method, the cylindrical blank having <=about No.7.5 crystal grain size and highly suitable to spinning can be obtained. Accordingly, the working yield is enhanced, the product precision is improved, a long- sized cylindrical blank can be produced, and productivity is also ameliorated.

Imoto Toshihiro

Papers

Bending method for tube

Production of cylindrical blank made of maraging steel