Bestex Kyoei Co., Ltd.

Minoru Tada

Mikio Morinaga

Takashi Nakamura

Hiroshi Kashima

Shinji Hirakawa

A method for manufacturing a fuel inlet having a good sealing property and a screw structure formed in a precise position involves expanding one end of a long-length stainless pipe (metal pipe) using a cored bar, the tip of the expanded portion which becomes non-uniform as a result of the expanding step is cut off, a screw structure is formed in the expanded portion by using a punch, the tip of the expanded portion which becomes non-uniform as a result of the screw structure forming step is cut off, and thereafter curl forming is conducted to the end of the expanded portion which becomes uniform by using a die so as to provide a seal portion.

Method for manufacturing fuel inlet

In manufacturing a fuel inlet, bulge forming and bend processing are conducted to a stainless pipe which will serve as an inlet pipe. Next, one end of the stainless pipe is eccentrically expanded, and the hardened portion is removed. After the pipe expanding step is finished, boring processing is conducted so that a breather pipe can be inserted into the inlet pipe, a guide is spot-welded to the inside of the eccentrically expanded portion, and a screw structure is formed. The inlet pipe and the breather pipe are degreased and cleaned as a pretreatment for brazing, and brazing is conducted by using BAg-4 (Low-temperature brazing material) at a temperature of 750-850&deg; C. Removing of the flux and cleaning are conducted as a post-treatment for brazing, and finally coating is conducted.

A fuel supplying assembly comprising a cap and a metal pipe having double screw threads thereon. The cap comprising a handle, an insertion portion and an idling mechanism that permits the handle to run idle with respect to the insertion portion when a predetermined force is applied.

Screw-thread forming apparatus, screw-thread forming method and fuel supply pipe assembly therewith

A deformed pipe having a deformed cross-sectional shape is press-fitted in a round hollow pipe having a circular cross-sectional shape. The deformed pipe has a plurality of radially outwardly projecting ridges having respective outermost vertexes held in contact with an inner circumferential surface of the round hollow pipe. The round hollow pipe and the deformed pipe are arc-welded to each other at axially spaced locations.

Double-walled pipe structure

When a flaring punch,is pressed into a pipe P from an end thereof to form a concentric or eccentric flared portion Pa, the taper angle &thgr; of the flaring punch is adjusted to apply axial compressive forces to the flared portion Pa thereby to maintain the wall thickness of the flared portion Pa at 70% or greater of the wall thickness of the blank pipe. If the flared portion is formed by a plurality of flaring punches,A,,B,,C having different maximum diameters at a plurality stages, then regions where the elongation is maximum are not localized, preventing the wall thickness from being locally reduced. If an eccentric highly flared pipe where the center of the flared portion Pa and the center of the pipe P are displaced from each other is formed, then a seam-welded region s of the pipe P is aligned with the direction in which the amount &egr; of eccentricity is maximum, making the flared pipe resistant to being ruptured.

Method of molding high expansion pipe and the high expansion pipe

In an apparatus and a method for forming threaded portions around a metal pipe with accuracy and ease, a preliminary forming is performed so as to recess portions of the metal pipe a little bit inwardly in the radial direction thereof by advancing auxiliary forming punches while keeping main forming punches as they are. Thereafter, by receding the auxiliary forming punches back, while advancing the main forming punches, simultaneously, the threaded portions are formed on outer periphery of the metal pipe,shifted by 180&deg; in phase thereof.

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Mie, Japan

Minoru Tada