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 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 device for forming circumferential grooves in pipe elements uses multiple geared cam bodies mounted on a carriage which rotates about a fixed pinion. The gears engage with the pinion which causes the geared cam bodies to rotate relative to the carriage. Traction surfaces and cam surfaces on the cam bodies traverse the outer surface of the pipe element and impress a circumferential groove therein. To substantially prevent rotation of the pipe element the pitch circle diameter of the pinion equals the outer diameter of the pipe element and the pitch circle diameters of the traction surfaces equal the pitch circle diameters of the gears.

A method for forming a spanner includes following steps: preparing a cylindrical metal blank, heating the metal blank to become softened, shaping the metal blank by pressing and pushing the metal blank forward on a shaping die with a pushing unit to form two head sections and a holding section connected between the head sections, and stamping the metal blank when the metal blank still has residual heat to flatten the holding section and shape each head section into a spanner-shaped part. Therefore, a spanner product is made. The method simplifies the processing procedures, decreases residual materials, achieves a quick shaping operation, reduces processing costs, and increases the forming efficiency.

A precision forming method of a high-efficiency and near-net hollow valve blank of an engine is provided, wherein the precision performing is realized by the cross wedge rolling mold, under the rolling the metal tubing for the valve deforms, with a middle part sunken and two ends elongating, the middle part forms a stem part of a hollow valve, the two ends form disk parts to be machined, and the connection sections between the disk parts and the stem part form neck parts having arced concave faces and a frustoconical lateral face in structure, achieving better consistency among the acquired hollow valve blanks. The disk part of each acquired hollow valve preformed blank is machined by the die-forging forming mold that is matched with the disk structure of the manufactured hollow valve, the hollow valve preformed blank is directly placed in the cavities of the die-forging forming mold for forging.

A precision forming method of a high-efficiency and near-net hollow valve blank of an engine is provided, wherein the precision performing is realized by the cross wedge rolling mold, under the rolling the metal tubing for the valve deforms, with a middle part sunken and two ends elongating, the middle part forms a stem part of a hollow valve, the two ends form disk parts to be machined, and the connection sections between the disk parts and the stem part form neck parts having arced concave faces and a frustoconical lateral face in structure, achieving better consistency among the acquired hollow valve blanks. The disk part of each acquired hollow valve preformed blank is machined by the die-forging forming mold that is matched with the disk structure of the manufactured hollow valve, the hollow valve preformed blank is directly placed in the cavities of the die-forging forming mold for forging.

Provided is a tubular structure that, even when clearance between a housing and the tubular structure is large, can prevent tube removal and that is capable of absorbing a certain amount of vibration in a lengthwise direction and a manufacturing method therefor. The present invention is a tubular structure comprising a tube member provided with annular protrusions, on a side of an insertion opening that is a tube end part or a receiving opening and, on the outer circumference of the ring member, ring members, arranged on an opposite side of the tube end part with respect to the annular protrusions, having two side surfaces that are vertical with respect to an axis A of the tube member.

Provided is a tubular structure that, even when clearance between a housing and the tubular structure is large, can prevent tube removal and that is capable of absorbing a certain amount of vibration in a lengthwise direction and a manufacturing method therefor. The present invention is a tubular structure comprising a tube member provided with annular protrusions, on a side of an insertion opening that is a tube end part or a receiving opening and, on the outer circumference of the ring member, ring members, arranged on an opposite side of the tube end part with respect to the annular protrusions, having two side surfaces that are vertical with respect to an axis A of the tube member.

A rotary crimping tool assembly includes a tool housing defining a crimping chamber, and one or more crimp wheels within the crimping chamber. The crimping chamber is configured to receive the portion of the structure in proximity to the crimp wheel(s). The crimp wheel(s) are configured to be pressed into and rotated relative to the portion of the structure to form one or more crimps in the portion of the structure.

The invention relates to a method for shaping a workpiece having a drum-type peripheral wall, on the inner face of which an inner profile featuring longitudinal ribs is formed by feeding at least one profiling roll to said inner face. According to the invention, at least one rotatably mounted profiling roll is fed to an inner face of the peripheral wall of the workpiece, and said at least one profiling roll rotates relative to the inner face of the peripheral wall such that the inner profile is formed in the inner face in a non-cutting manner.