A fin-assembled tube includes a helical fin arranged in an interior of a tube, wherein the tube has: a straight tube portion the center line of which extends in a substantially straight line; and a bent portion the center line of which is curved, and the helical fin is formed such that a helical pitch in an axial direction is longer in a portion positioned in the bent portion relative to the helical pitch in a portion positioned in the straight tube portion, the helical pitch being a pitch of a plate-shaped fin material twisted by a certain angle about the center line.

A method of radial incremental forming a component having a component inner mold line (IML) includes providing a mandrel having geometry configured to mate with the IML. The method also includes inserting the mandrel into a tubular workpiece composed of a formable material, to thereby sleeve the workpiece over the mandrel. The method additionally includes mounting the workpiece sleeved over the mandrel onto a drive mechanism configured to rotate the mandrel and having a forming tool configured to shift relative to the workpiece. The method further includes regulating, according to provided toolpath instructions, the drive mechanism to rotate the workpiece sleeved over the mandrel in concert with shifting the forming tool relative to the workpiece to incrementally deform the workpiece therewith over the mandrel and thereby form the component. A tool system having an electronic controller may employ the subject method to radially incrementally form a component.

A method of radial incremental forming a component having a component inner mold line (IML) includes providing a mandrel having geometry configured to mate with the IML. The method also includes inserting the mandrel into a tubular workpiece composed of a formable material, to thereby sleeve the workpiece over the mandrel. The method additionally includes mounting the workpiece sleeved over the mandrel onto a drive mechanism configured to rotate the mandrel and having a forming tool configured to shift relative to the workpiece. The method further includes regulating, according to provided toolpath instructions, the drive mechanism to rotate the workpiece sleeved over the mandrel in concert with shifting the forming tool relative to the workpiece to incrementally deform the workpiece therewith over the mandrel and thereby form the component. A tool system having an electronic controller may employ the subject method to radially incrementally form a component.

Disclosed is a tube-propelling apparatus for a tube bending machine. The apparatus comprises a main tube-propelling base mounted on a slide rail mechanism of a tube bending machine tool, wherein a penetrating hole though which both a fixing sleeve and a core rod pass is provided on the main tube-propelling base, the rear end of the fixing sleeve is fixed in the penetrating hole, and the front end of the fixing sleeve is provided with a tube clamping apparatus. The propelling apparatus further comprises a surplus material auxiliary propelling base mounted on the slide rail mechanism of the tube bending machine tool, wherein the surplus material auxiliary propelling base is provided with a through-hole coaxial with the penetrating hole of the main tube-propelling base. An auxiliary pushing sleeve is mounted in the through-hole, and the core rod passes through the auxiliary pushing sleeve. Meanwhile, the auxiliary pushing sleeve is sheathed in the fixing sleeve and the front end of the auxiliary pushing sleeve is provided with a propelling head engaging with a tube. The tube-propelling apparatus has a simple and rational structure, and can fully utilize surplus material.

Disclosed is a tube-propelling apparatus for a tube bending machine. The apparatus comprises a main tube-propelling base mounted on a slide rail mechanism of a tube bending machine tool, wherein a penetrating hole though which both a fixing sleeve and a core rod pass is provided on the main tube-propelling base, the rear end of the fixing sleeve is fixed in the penetrating hole, and the front end of the fixing sleeve is provided with a tube clamping apparatus. The propelling apparatus further comprises a surplus material auxiliary propelling base mounted on the slide rail mechanism of the tube bending machine tool, wherein the surplus material auxiliary propelling base is provided with a through-hole coaxial with the penetrating hole of the main tube-propelling base. An auxiliary pushing sleeve is mounted in the through-hole, and the core rod passes through the auxiliary pushing sleeve. Meanwhile, the auxiliary pushing sleeve is sheathed in the fixing sleeve and the front end of the auxiliary pushing sleeve is provided with a propelling head engaging with a tube. The tube-propelling apparatus has a simple and rational structure, and can fully utilize surplus material.

An apparatus for improving the quality of tube bending; adapted to be used in bending machines and comprises a substantially longitudinally extended mandrel, adapted to be inserted into a tube to be bent and having a rigid portion and a flexible portion arranged in series, the latter comprising a series of mandrel segments connected by articulated joints; the apparatus also comprises at least one motion-sensitive sensor, which is integral with at least one of the mandrel segments, and elements for processing the motion information acquired by the sensor.

An apparatus for improving the quality of tube bending; adapted to be used in bending machines and comprises a substantially longitudinally extended mandrel, adapted to be inserted into a tube to be bent and having a rigid portion and a flexible portion arranged in series, the latter comprising a series of mandrel segments connected by articulated joints; the apparatus also comprises at least one motion-sensitive sensor, which is integral with at least one of the mandrel segments, and elements for processing the motion information acquired by the sensor.

Method for mitigating stress corrosion cracking at an internal (i.e., wetted-side) weld area in piping of a nuclear power plant includes the steps of actuating a radially movable tool to produce a radial bad against the internal (i.e., normally wetted) surfaces at or near the weld area to create a deep residual compressive stress state at the wetted surface of the weld. The method permits post-process verification by physical measurements of surface distortion.

A fin-assembled tube includes a helical fin arranged in an interior of a tube, wherein the tube has: a straight tube portion the center line of which extends in a substantially straight line; and a bent portion the center line of which is curved, and the helical fin is formed such that a helical pitch in an axial direction is longer in a portion positioned in the bent portion relative to the helical pitch in a portion positioned in the straight tube portion, the helical pitch being a pitch of a plate-shaped fin material twisted by a certain angle about the center line.

A mandrel 10 for producing a thin-walled bent tube having a bending portion with high strength and a small radius of curvature by rotary draw bending without either cracks in an outside of bend or winkles and buckling in an inside of bend occurring includes a shank 14, a connection mechanism 15 and a mandrel ball 16. In a cross-section orthogonal to an axial direction of the mandrel ball 16 at a central position in the axial direction of the mandrel ball 16, the mandrel ball 16 has a first position 19 and a second position 20 at which a first straight line m that passes through a mandrel ball center 17 meets an outer periphery 21 of the mandrel ball. Further, a ratio (L.sub.1/L.sub.2) between a dimension L.sub.1 from the mandrel ball center 17 to the first position 19 and a dimension L.sub.2 from the mandrel ball center 17 to the second position 20 is in a range of 0.915 to 0.976.