A method is provided for cold forming center web or webless tapered piston pins in one forming sequence. The method eliminates secondary operations such as but not limited to machining, annealing, coating and secondary forming.

The method includes the steps of cutting a metal rod into a substantially cylindrical slug piece, die extruding the slug piece to form a first cavity in the slug piece, optionally die extruding the slug piece to form a second cavity in the slug piece, piercing the slug piece to form the slug piece into a hollow cylindrical piece, die extruding the hollow cylindrical piece at either end to form a hollow cylindrical piece having a taper on an internal surface of the hollow cylindrical piece at either end.

A method of making a metallic shell (2) for a spark plug (1) is provided. The metallic shell (2) includes a multi-stepped through hole (8), an intermediate tubular portion (21), a tip end side tubular portion (22) and a base end side tubular portion (23). The through hole (8) includes a large diameter hole section (8L), an intermediate diameter hole section (8M) and a small diameter hole section (8S). The method includes the steps of cutting a metal pipe that is used as a starting material to a predetermined length and thereby preparing a pipe-shaped blank (P), and subjecting the blank (P) to a deformation process and thereby forming the blank (P) into the metallic shell (2). A spark plug and a method of making the same are also provided.

The object of this invention is to propose a manufacturing method for manufacturing component part for the variable capacity turbine, and the structure of the nozzle driving member, which will simplify the structure of the component part for the adjustable nozzle mechanism, the manufacturing work which results in lowering the manufacturing count and cost, as well as the number of component part, and in lightening the weight of the variable capacity turbine. In order to manufacture the component part for a radial-flow variable capacity turbine, in which the actuating gas is forced to flow from a spiral scroll formed in the turbine casing to a turbine rotor in a radial direction, through multiple nozzle vanes of which the angle is adjustable by an adjustable nozzle mechanism, for rotating the turbine rotor, this manufacturing method according to this invention is distinguished by the configuration in which a column shaped connecting pin is formed as a single structure with a plate member by a pressing, or a precision molding by partially forcing the surface of the plate member to protrude in a column shape.

Pressure is applied to a cylindrical material (41) in the axial direction so as to perform squeezing process by extrusion, thereby narrowing the forward end of the material (41) with respect to the direction in which the pressure is applied. Obtained as a result of extrusion is an intermediate molding (46) having a cylindrical portion (43), a slanted portion (44), which is formed as a continuous, integral body with the cylindrical portion (43) and has a gradually reduced diameter, and a small diameter cylindrical portion (45), which is formed coaxially with the cylindrical portion (43) and has a diameter smaller than that of the cylindrical portion (43). The slanted portion (44) is flattened by applying pressure from the end of the cylindrical portion (43) of the intermediate molding (46) in the axial direction in the state where the outer and inner cylindrical surfaces of the cylindrical portion (43) and the outer cylindrical surface of the small diameter cylindrical portion (45) are restrained. A first housing (11) is formed by forming the cylindrical portion (43), the slanted portion (44) and the small diameter cylindrical portion (45) respectively into a body portion (14), bottom portion 17 and a coupling portion 23. Compared with a case where a housing is forged from a material in the shape of a solid column, a first housing according to the present invention can be formed with a substantially reduced pressure and is more convenient to form. As it is formed by forward extrusion, high precision formation is possible without the need of cutting work.

Procédé de fabrication d'un axe dont le passage axial de révolution présente à ses extrémités un élargissement à profil particulier. La machine pour la mise en oeuvre de ce procédé comporte une matrice 8 montée coulissante dans un support fixe 17 et propre à recevoir et à maintenir par coincement une ébauche d'axe 1 ; un contre-poinçon 7b à épaulement profilé 13b, engagé par sa pointe dans une extrémité dudit alésage 23 ; un poinçon mobile 7a à épaulement profilé 13a, propre à s'engager par sa pointe dans l'autre extrémité dudit alésage 23 ; et des moyens de pression propres à exercer une force sur ledit poinçon mobile 7a de sorte que les extrémités du passage axial 3 de ladite ébauche d'axe 1 soient comprimées et déformées par estampage entre lesdits épaulements profilés 13a, 13b des poinçons.

In a method of making a metallic shell (100) for a glow plug, a columnar blank (W) is extruded to have an enlarged recess (106) on the upper end surface of the blank (W) so as to make an upper tubular portions (104), while extruded to have an enlarged recess (107) on the lower end surface to make a first tubular end (105) circular in section, an outer diameter of which is smaller than that of the upper tubular portion (104). The blank (W) is transferred without inverting it, and the blank (W) is reduced at its upper tubular portion (104) to make a second tubular end (113) hexagonal in section, an outer diameter of which is smaller than that of a middle portion (112) of the blank (W), but greater than that of the first tubular end (109). Then, the blank (W) is transferred without inverting it, and punched to communicate the first tubular end with the second tubular end by means of an axial bore (116). In other method, a mandrel (65a) is forced into the upper tubular portion (108) to form a second tubular end (113) hexagonal in section, an outer diameter of which is smaller than that of a middle portion of the blank (W), but greater than that of the first tubular end. In the forcing process, a cooling liquid oil (Cm) is supplied between the upper tubular portion (108) of the blank (W) and the mandrel (65a) to alleviate friction heat, the cooling liquid oil (Cm) flowing down between the upper tubular portion (108) of the blank (W) and the mandrel (65a) is led to the axial bore (116) as an escape path of the liquid oil (Cm).

The invention provides a process of producing a nozzle member as a single part having an inner diameter which varies along an axial direction of the nozzle member. The process comprises the step of drawing a pipe stock having a predetermined outside profile so as to transfer the outside profile in an axial symmetrical relationship to an inside profile of the pipe stock. By the process, a nozzle member can be produced readily with a high degree of accuracy.

Apparatus and a method are provided to form the interior of a fuel injector spray tip by use of a cold forming punch to form a V-shaped spray tip interior configured to reduce fuel dribble and thereafter finishing the interior by use of an EDM electrode (48) to form precision valve seat and fuel sack surfaces.