MANUFACTURE OF SEAMLESS ECCENTRIC REDUCER TUBE JOINT

摘要

PURPOSE:To manufacture an eccentric tube joint efficiently and economically by forming a circular metallic plate of specified thickness and diameter into a roughly drawn container and drawing the vertical wall and inclined part under a specified condition. CONSTITUTION:A circular metallic plate 10 that has thickness 0.7-1.1 times that of the large diameter part of the product, diameter 2.0-2.3 times inner diameter of the large diameter part of the product and the ration of thickness to diameter is 0.015-0.024 is deep drawn to made a roughly drawn container 15. Then, eccentric is made with a punch 19 and a die 23 to form an eccentric container 24 that has a verticall wall 33 and an inclined part 26 and a bottom part 25 outer diameter D1 of which is 0.70-0.80 times that D0 of the container 25. Then, the prescribed eccentric drawing is performed at =20% bottom diameter reduction ratio per work and =20 deg. angle increase in the inclined part. A desired bottomed container 29 is manufactured by further reducing outer diameter of the bottom part 25 and small diameter part 27. Finally, the bottom 25 of the finish drawn container 29 is removed to complete a product.