An apparatus for forming a round or oval shaped duct for all AC systems in one continuous operation where two driving rolls advance a flat metal sheet to at least one multi-positioning bending roll, where the at least one bending roll is moveable to a bending position for different curvatures and a non-bending position. The driving rolls advance the sheet through while the bending roll bends the sheet to form the curved sides, and the bending roll in the non-bending position form the flat sides of the oval shaped duct. A position sensor detects the position of the flat metal sheet in the rolls to control the location along the sheet where the bending roll is moved to either of the bending or non-bending positions while the driving rolls are stopped. An adhesive dispenser joins both ends of the sheet, resulting in a complete duct.

The disclosure relates to a method for controlling a stretch-reducing mill. Tube ends of stretched tubes are optimized by controlling one or more motors of the stretch-reducing mill. The method includes at least one outlet-side wall thickness measurement and an automatic adjustment of the value of a speed change of the motors to the tube wall thickness profile. The progression of the speed changes over time of individual or all motors is also automatically adjusted on the basis of the tube wall thickness measured values.

The disclosure relates to a method for controlling a stretch-reducing mill. Tube ends of stretched tubes are optimized by controlling one or more motors of the stretch-reducing mill. The method includes at least one outlet-side wall thickness measurement and an automatic adjustment of the value of a speed change of the motors to the tube wall thickness profile. The progression of the speed changes over time of individual or all motors is also automatically adjusted on the basis of the tube wall thickness measured values.

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 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.

A method for producing hot-rolled, seamless pipes having at least one wall thickening which can be arranged at any positions over the length of the pipe, wherein by means of a multiple-stand mandrel bar rolling mill, the rolls roll a hollow shell on a mandrel bar as an inner tool to a required nominal wall thickness and produce at specified positions over the length of the pipe a required wall thickening on the outer side of the pipe by opening the rolls in the rolling stands. The thickened wall is produced and finish-rolled by two rolling stands that are consecutive as seen in the rolling direction, in which the deviations of the finished contour of the thickening from an ideal circular cross-section are minimised, wherein the rolling stands located upstream are likewise opened as to avoid any contact of the rolls of these rolling stands with the previously produced thickening.

A method for producing hot-rolled, seamless pipes having at least one wall thickening which can be arranged at any positions over the length of the pipe, wherein by means of a multiple-stand mandrel bar rolling mill, the rolls roll a hollow shell on a mandrel bar as an inner tool to a required nominal wall thickness and produce at specified positions over the length of the pipe a required wall thickening on the outer side of the pipe by opening the rolls in the rolling stands. The thickened wall is produced and finish-rolled by two rolling stands that are consecutive as seen in the rolling direction, in which the deviations of the finished contour of the thickening from an ideal circular cross-section are minimised, wherein the rolling stands located upstream are likewise opened as to avoid any contact of the rolls of these rolling stands with the previously produced thickening.

An apparatus for forming an oval shaped duct, as well as a round duct for all required sizes and thicknesses for an AC system, in one continuous operation where two driving rolls advance a flat metal sheet to at least one multi-positioning bending roll, where the at least one bending roll is moveable to a bending position for different curvatures and a non-bending position. The driving rolls advance the sheet through while the bending roll bends the sheet to form the curved sides, and the bending roll in the non-bending position form the flat sides of the oval shaped duct. A position sensor detects the position of the flat metal sheet in the rolls to control the location along the sheet where the bending roll is moved to either of the bending or non-bending positions while the driving rolls are stopped. An adhesive dispenser joins both ends of the sheet, resulting in a complete duct.

An apparatus for forming an oval shaped duct, as well as a round duct for all required sizes and thicknesses for an AC system, in one continuous operation where two driving rolls advance a flat metal sheet to at least one multi-positioning bending roll, where the at least one bending roll is moveable to a bending position for different curvatures and a non-bending position. The driving rolls advance the sheet through while the bending roll bends the sheet to form the curved sides, and the bending roll in the non-bending position form the flat sides of the oval shaped duct. A position sensor detects the position of the flat metal sheet in the rolls to control the location along the sheet where the bending roll is moved to either of the bending or non-bending positions while the driving rolls are stopped. An adhesive dispenser joins both ends of the sheet, resulting in a complete duct.

A rolling mill for rolling hollow or, in all cases, concave rod-shaped bodies, in particular tubes, in particular seamless tubes, said rolling mill comprising a rolling section (10) with a plurality of mill stands and/or rolling dies (11) arranged in succession to define a rolling axis Y, said rolling mill further comprising moving means for moving a mandrel (20) and a tubular blank (21) fitted onto an end portion (22) of said mandrel (20) along said rolling axis and through said mill stands or rolling dies (11) in succession; wherein said moving means are structured so as to move said mandrel (20) and said blank (21) along said rolling axis Y and through said mill stands or rolling dies (11) in succession by applying a traction on said mandrel.