METHOD FOR PRODUCING PIPE MATERIAL FROM PLATE MATERIAL AND DIE FOR IRONING

摘要

PURPOSE:To produce a pipe material which is equivalent in the accuracy of a wall thickness and sectional shape to a drawn steel pipe from a plate material by subjecting the plate material to drawing then to ironing to make the wall thickness uniform and to trim the sectional shape thereof then machining both ends. CONSTITUTION:A blank material A in the case of drawing is placed on a bank holder plate and when a female die is lowered, the bottom surface of a die 5 contacts the top surface of the material A and increases further the fitting depth to a punch 3 thereby drawing the material A to a bottomed pipe shape. A blank material B in the case of ironing is supplied into the through-hole of a guide plate 36 by facing downward the bottom part thereof. A punch 32 fits into the material B and intrudes into the opening of a die 34. The side part of the material B is thus gradually elongated. The material B passing a bearing part 43 is made uniform in the wall thickness of the side face part and at the same time the sectional shape is trimmed. The bottom of the material B projects from the bottom surface of the die 34 and when the open end passes the top end face of a pawl 48, the pawl 48 advances. The material 32 is removed from the punch 32 upon ascending of the punch 32.