A forging roll device includes, a pair of roll axes which are provided so that an axis center of each of the roll axes are parallel to each other and in which a die is attached to each of the roll axes; and a material holder/conveyer which conveys a held shaping target material between the pair of roll axes, wherein, each one of the pair of roll axes includes a plurality of die attaching surfaces positioned in a circumferential direction, and an outer circumferential surface between any of two of the plurality of die attaching surfaces in each one of the pair of roll axes is closer to a planar surface than a cylindrical surface with the axis center as the center.

A forging roll device includes, a pair of roll axes which are provided so that an axis center of each of the roll axes are parallel to each other and in which a die is attached to each of the roll axes; and a material holder/conveyer which conveys a held shaping target material between the pair of roll axes, wherein, each one of the pair of roll axes includes a plurality of die attaching surfaces positioned in a circumferential direction, and an outer circumferential surface between any of two of the plurality of die attaching surfaces in each one of the pair of roll axes is closer to a planar surface than a cylindrical surface with the axis center as the center.

A method for producing a valve body of a hollow valve includes providing a workpiece blank or semi-finished product, spin extruding the workpiece to produce a preform having a cup with a hollow shape formed by the cup wall. A hollow valve produced by this method is also provided.

The invention relates to a method for producing a valve body for a hollow valve. Said method comprises the following steps: providing a workpiece, blank or semi-finished product and a forming punch, introducing a protective layer between the workpiece and the forming punch (22) and press forming the workpiece to produce a preform. The invention also relates to a hollow valve produced by means of this method.

The invention relates to a method for producing a valve body for a hollow valve. Said method comprises the following steps: providing a workpiece, blank or semi-finished product and a forming punch, introducing a protective layer between the workpiece and the forming punch (22) and press forming the workpiece to produce a preform. The invention also relates to a hollow valve produced by means of this method.

A method for producing a valve body of a hollow valve includes providing a workpiece blank or semi-finished product, spin extruding the workpiece to produce a preform having a cup with a hollow shape formed by the cup wall. A hollow valve produced by this method is also provided.

The invention relates to a method for producing poppet valves, the method including: cross-wedge rolling a preform (2), which has at least one disk portion (4) and a shaft portion, to produce a valve blank (10), wherein a diameter of the shaft portion (6) is reduced substantially to a shaft diameter of a shaft (16), and additionally a length of the shaft portion (6) is increased substantially to a length of the shaft (16) by means of a rolling-out process.

A method for manufacturing an engine poppet valve may comprise a forging operation, a diameter-decreasing operation, and a joining operation. At the forging operation, an intermediate member at which a valve head portion and an intermediate stem portion are made integral by way of a neck portion may be formed. At the diameter-decreasing operation, the intermediate stem portion may be inserted between/among a plurality of diameter-decreasing tools that have stem member compressing surfaces and stem member inlet surfaces formed so as to be progressively distant from the stem member compressing surfaces and toward the tip end and that are arranged at a plurality of circumferentially equipartite locations about a circumference of the intermediate stem portion, application at the intermediate stem portion from a base end portion of compressive forces which are inwardly directed in a radial direction from the compressing surfaces of the respective diameter-decreasing tools which have been made to come in contact with a part of the intermediate stem portion that has been made to rotate while being displaced in relative fashion in a direction along a central axis thereof causing the part of the intermediate stem portion to be decreased in diameter from the base end portion and causing a main body portion of a first stem portion to be formed at the intermediate member and also causing formation by the compressing surfaces of a stepped portion which is continuous with the main body portion, and formation, by an absence of decrease in diameter of a remaining portion at the intermediate stem portion, of a second stem portion which is broader in girth than the main body portion and which is continuous with the neck portion and which is also continuous with the main body portion by way of the stepped portion. At the joining operation, a stem end member having a same outside diameter as the main body portion may be joined to a base end portion of the main body portion.

A secondary battery includes an electrode assembly in which first and second electrodes and a separator provided between the first and second electrodes are wound, the first and second electrodes each including a non-coated portion disposed at a long side end thereof, exposed to an outside of the separator, and having no active material applied thereto; and a current collecting plate provided at one end of the electrode assembly at which the non-coated portion of the first electrode is exposed, the current collecting plate including a central portion corresponding to a core of the electrode assembly, in which the central portion includes a first welding portion having a thickness smaller than a thickness of a remaining portion of the current collecting plate. A battery pack having a plurality of the secondary batteries and a vehicle having the battery pack are also provided.

A method for producing rotationally symmetric structural components of metal, in particular steel, is provided. A blank is arranged in a torsion-proof manner on a first receptacle, the receptacle is rotated about a rotation axis so that the blank is caused to rotate about this rotation axis, at least one linear shaping element with a contour having at least partially an unrolled external contour of the rotationally symmetric structural component or a preform of the structural component is moved tangentially to the surface of the synchronously rotating blank, and the linear shaping element is at the same time pressed against the blank so that during the tangential movement the contour of the linear shaping element is formed at least partially into the blank. A kingpin or link pin of a connection link with a connection shaft and a link outer part is produced.