At a diameter-decreasing operation during manufacture of a poppet valve, an intermediate stem portion at which a valve head portion and an intermediate stem portion are made integral by way of a neck portion may be inserted between/among diameter-decreasing tools. Application of compressive forces from compressing surfaces of the diameter-decreasing tools may cause a part of the intermediate stem portion to be decreased in diameter and may cause a main body portion of a first stem portion to be formed and may cause formation of a stepped portion which is continuous with the main body portion, and formation, by an absence of decrease in diameter, 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.

The technical field of metal plastic forming processes and equipment, and provides a device and method for forming shaft part by two-roller flexible skew rolling. The device comprises two skew rollers, a guiding plate, two guiding cylinders and an axial pushing device; the skew rollers can do same-direction rotation motion, radial feeding motion and tilt angle adjustment motion; the guiding plate is arranged between the two skew rollers and is used for limiting the radial movement of a blank; the two guiding cylinders are arranged on the two sides of the two skew rollers to limit swing of the blank; and the axial pushing device is arranged at one end of the blank and is used for applying axial pushing force to the blank, and the blank is rolled into a shaft part in a space defined by the skew rollers and the guiding plate. The method of the invention includes a radial compression forming process, a roller tilting forming process, a skew rolling diameter reduction forming process and a roller leveling forming process. The device and method for forming shaft part by two-roller flexible skew rolling have the advantages that forming equipment is simple, the tonnage is small, flexible production can be achieved, and core loose defects can be reduced and even avoided.

The present invention discloses a rolling-bulging forming hydraulic machine for tubular products, which includes a frame. The frame is provided with an upper rolling mechanism, a lower rolling mechanism, a fixed liquid bulging hydraulic cylinder and a movable liquid bulging hydraulic cylinder. The upper rolling mechanism and the lower rolling mechanism are arranged oppositely, and the upper rolling mechanism and the lower rolling mechanism are used to roll surfaces of a to-be-machined tubular product. The fixed liquid bulging hydraulic cylinder and the movable liquid bulging hydraulic cylinder are arranged oppositely, and the fixed liquid bulging hydraulic cylinder and the movable liquid bulging hydraulic cylinder are used to perform hydraulic bulging on the to-be-machined tubular product.

A hot-spinning formation method for large-diameter titanium alloy cylindrical parts. A workblank is placed in a resistance furnace to heated to 600-650° C., is maintained at this temperature for 0.5-1 h and is then taken out of the resistance furnace; after the workblank is heated, the inner diameter of the workblank becomes larger; the heated workblank is installed on a mandrel, and spinning is started when a maximum clearance between the workblank and the mandrel is less than 0.5 mm; the mandrel and the spinning rollers do not need to be preheated, and a multi-pass spinning process is adopted, such that the workblank can deform more uniformly. A vertical spinning lathe is used for spinning, the mandrel is easy to change, and the workblank is easy to assemble and disassemble.

The present disclosure relates to a method for producing a profiled hollow shaft for a telescopic steering shaft of a motor vehicle. A hollow shaft to be machined and a roller forming head having at least one roller are provided. A groove is produced in the hollow shaft by moving the hollow shaft relative to the roller forming head. In order to provide an improved and less expensive method for producing a profiled hollow shaft for a telescopic steering shaft of a motor vehicle, the hollow shaft is moved relative to the roller forming head exclusively in the direction of the longitudinal axis of the hollow shaft. The disclsoure also relates to a steering shaft having rolling body raceways.

The present disclosure relates to a method for producing a profiled hollow shaft for a telescopic steering shaft of a motor vehicle. A hollow shaft to be machined and a roller forming head having at least one roller are provided. A groove is produced in the hollow shaft by moving the hollow shaft relative to the roller forming head. In order to provide an improved and less expensive method for producing a profiled hollow shaft for a telescopic steering shaft of a motor vehicle, the hollow shaft is moved relative to the roller forming head exclusively in the direction of the longitudinal axis of the hollow shaft. The disclsoure also relates to a steering shaft having rolling body raceways.

The present invention relates to a cross rolling method having the step of shaping a component blank rotating about a main axis of rotation by means of at least two cross rolling tools located substantially opposite each other with respect to the component blank for the production of a component (1, 2) that is at least partly non-rotationally symmetrical and non-cyclically symmetrical with respect to the main axis of rotation, by moving the cross rolling tools along their main direction of movement. The invention also relates to a cross rolling tool for producing an at least partly non-rotationally symmetrical and non-cyclically symmetrical component (1, 2). Likewise, the present invention relates to an apparatus for carrying out the method according to the invention and a component (1, 2) produced in accordance with the method according to the invention.

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. Each cam surface has a region of increasing radius and may have a region of constant radius. Second cam surfaces, positioned in spaced relation axially to the first cam surfaces, may also extend around the cam bodies. The second cam surfaces have a constant radius and limit flare of the pipe element.

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. Each cam surface has a region of increasing radius and may have a region of constant radius. Second cam surfaces, positioned in spaced relation axially to the first cam surfaces, may also extend around the cam bodies. The second cam surfaces have a constant radius and limit flare of the pipe element.

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.