Honda Giken Kogyo Kabushiki Kaisha

Atsuo Kasuya

Tamio Furuya

Shigeo Kaiho

Nobuyuki Otsuka

Yusho Nakayama

Masayuki Kumashiro

A first mandrel segment comprised of first and second resinous sheets including proximal end portions vertically spaced from each other is initially inserted into a pipe having a weld seam extending longitudinally thereof. Since the first mandrel segment has a thickness smaller than an inside measurement of the pipe, the first mandrel segment can be inserted into the pipe without being caught by a bulged portion of the weld seam protruding inwardly of the pipe. After the insertion of the first mandrel segment, a second mandrel segment comprised of a third resinous sheet is forced into a spacing between the first and second resinous sheets. By thus forcing the third resinous sheet into the spacing, the first resinous sheet is pushed vertically to come into intimate contact with the bulged portion. The pipe having the first, second, and third resinous sheets thus inserted therewithin is then bent by a bender. After the bending of the pipe, the third resinous sheet is first pulled out of the bent pipe. The first and second resinous sheets are subsequently pulled out of the bend pipe.

Pipe bending method and mandrel assembly for carrying out the method

A method of pressing a blank comprises the steps of pressing the blank between a die assembly having a cavity with a highly viscous substance contained therein and a punch, inserting the punch into the cavity to increase a pressure of the highly viscous substance in the cavity, and pressing the blank against a surface of the punch under the pressure of the highly viscous substance. The pressing method can form pressed product of complex shape highly accurately and free from cracks, wrinkles, or other damages. There is also disclosed a punch and die press suitable for effecting the abovesaid pressing method.

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Sayama, Japan

Atsuo Kasuya