A first member (81) including a first opening portion that opens to one side in a circumferential direction around an axis of a rack shaft corresponding to a rotation axis of a nut, and a second member (82) including a second opening portion that confronts the first opening portion, and that opens to the other side in the circumferential direction, are molded so that a first insertion portion (71) and a second insertion portion (72) are inclined along a lead angle of a ball circulation groove with respect to a connection portion (73), and the first and second openings are joined in an abutted state, thereby forming a tube (44).

A forging press apparatus includes: a die with a die hole into which a material is to be contained and a relief hole smaller in diameter than the die hole; a molding punch configured to press an inner portion inside a peripheral portion of the material contained in the die hole; and a pressing member provided around an outer periphery of the molding punch to press the peripheral portion. A method includes: loading the material into the die; and forging the cup structure shaped by pressing the inner portion inside the peripheral portion of the material with the molding punch to cause the peripheral portion of the material to be brought into contact with the pressing member, and a part of the material to be pushed out into the relief hole by the molding punch to form a projection while a space is secured below the projection.

A method for manufacturing an aircraft door with an integral structure. The method includes the following steps: producing a forged blank (7); die-cutting the forging blank (7) between a substantially smooth lower die (8) and an upper die (9) defining a plurality of cells and producing a die-cut part having a honeycomb structure having an open face and a closed face closed by a wall; an inner wall of the honeycomb structure is machined to define at least one recess defined by a web connecting the closed face and the open face and a base protruding substantially perpendicular to the web on the open face of the die cut component.

A method of producing a press-formed product includes a steel plate heating step, a hot forging step and a hot stamping step. In the steel plate heating step, a steel plate is heated to 950 C. or more. In the hot forging step, the heated steel plate is forged to form a varying-thickness steel plate. In the hot stamping step, the heated varying-thickness steel plate is subjected to press-working by a press tooling to form a press-formed product, and the press-formed product that is formed is cooled inside the press tooling. Thus, a press-formed product that has high strength and for which a reduction in weight is possible can be produced.

An embodiment includes a method for net shape forging of a manifold block, comprising: starting with a single bar having a first cross-sectional area, placing a work piece area of the single bar in a die; and upsetting, via longitudinal movement of the single bar, the work piece area of the single bar in the die, wherein the single bar is pressed into the die to reduce its length; whereby the work piece area of the single bar is displaced to an increased cross-sectional area as compared to the first cross-sectional area. Other aspects are described and claimed.

[Object] To provide a press-molding apparatus capable of appropriately thickening a vertical wall portion while preventing the occurrence of buckling. [Solution] Provided is a press-molding apparatus configured to mold a press-molded product by performing press working on a work, the press-molding apparatus including: a support member that supports the work with a first thickness having a hat-shaped cross-section or a U-shaped cross-section; a punch member that moves relative to the support member to execute press working so as to reduce a height of a vertical wall portion of the work and thicken the vertical wall portion to a second thickness; and a pad member that faces the support member with the vertical wall portion to be thickened placed therebetween, the pad member being biased by a biasing member and having its distance to the support member kept equal to or smaller than the second thickness during the press working.

A method of manufacturing a cylindrical ring member includes a step of forming a metal intermediate material having a cylindrical portion and a chamfering step by cold forging in which a normal chamfer portion is formed on an axial end peripheral edge of the cylindrical portion by pressing a radial end portion of an axial end surface of the cylindrical portion against an annular chamfering surface provided in a mold configuring a mold device. A chamfering step is performed by cold forging in a state where a preliminary chamfer portion, of which a width dimension in a radial direction is larger than a width dimension of the normal chamfer portion in a radial direction, is formed on the axial end peripheral edge of the cylindrical portion.

The present invention discloses a Fluid End and its manufacturing method. The conventional fluid end manufacturing methods involve machining of all surfaces.

This demands more input stock for manufacturing process and a lot of material wastage during machining process. In the conventional processes involving open die forging followed by machining result into only about 34% utilization of material. In the present invention, fluid end component geometry is optimized. Assembly surfaces are machined whereas other or non-assembly surfaces are as-forged condition. The method of invention also results in significant reduction in machining time and chip removal. The present invention also discloses a process of manufacturing using a combination of open die and closed die forging, and machining. It involves the steps of cogging an ingot to form billet for closed die forging using open die forging, forging the billet in closed die using forging equipment, semi-finish/rough/partial machining, heat treatment, drilling and finish machining the component. Most of the non-assembly areas of the fluid end are left in as-forged condition.

The present invention provides a method of near-net-shape forged molding of the coupler knuckle of the railway vehicle. The present invention solves the problems that the manufacturing the forged coupler knuckle is difficult, and the process is complex, etc. The method of the present invention includes the following steps: material preparation, heating, blank prefabrication, pre-forging, closed-die forging, quenched-tempered heat treatment using waste heat, finish machining, flaw detection, etc. With the closed-die forging technology, the near-net-shape molding of the coupler knuckle can be achieved. The energy and the material are saved. The contour shape and the size do not need to be machined. The use ratio of the material can reach more than 92%. Moreover, during the entire molding, the workpiece is in the three-dimensionally stressed state all the time. The product has a dense texture, a high toughness, a good fatigue resistance, and a long lifetime.

A method for manufacturing a tubular member has: a step of disposing a steel pipe which is a material in an outer the having an inner surface having the same shape as an outer form of the tubular member with at least a part of the steel pipe being separated from the inner surface; and a step of compressing the steel pipe in the axial direction by decreasing a relative distance between a pair of pressurizing dies that respectively abut both end surfaces of the steel pipe in the axial direction in a state where a core the portion having an outer surface shape that is the same as inner surface shapes of the both end portions of the tubular member in the axial direction is inserted between the pair of pressurizing dies with at least a pan of the core the portion being separated from the inner surface of the steel pipe.