The present disclosure relates to an apparatus for forming flange of circular duct, and the apparatus for forming flange of circular duct according to the present disclosure includes a forming jig that is disposed to surround an outer circumference of a lower end portion of a duct, and that has a forming groove on a surface facing the duct; a support that supports a lower end of the duct below the forming jig; a height adjustor that adjusts height of the support; and a forming unit that hits an inner circumference of the lower end portion of the duct to form a flange having a shape corresponding to the forming groove of the forming jig on the lower end portion of the duct, wherein the forming groove includes a first forming surface formed on the surface facing the duct, and a second forming surface additionally extended from a distal end portion of the first forming surface, and the height adjustor is configured to adjust a relative position of the support with respect to the forming jig such that the flange is formed only on the first forming surface or formed on the first forming surface and the second forming surface.

The present disclosure relates to an apparatus for forming flange of circular duct, and the apparatus for forming flange of circular duct according to the present disclosure includes a forming jig that is disposed to surround an outer circumference of a lower end portion of a duct, and that has a forming groove on a surface facing the duct; a support that supports a lower end of the duct below the forming jig; a height adjustor that adjusts height of the support; and a forming unit that hits an inner circumference of the lower end portion of the duct to form a flange having a shape corresponding to the forming groove of the forming jig on the lower end portion of the duct, wherein the forming groove includes a first forming surface formed on the surface facing the duct, and a second forming surface additionally extended from a distal end portion of the first forming surface, and the height adjustor is configured to adjust a relative position of the support with respect to the forming jig such that the flange is formed only on the first forming surface or formed on the first forming surface and the second forming surface.

A shape change prediction method for a press formed part for predicting a shape change of the press formed part with a lapse of time units after springback at a moment of a release from a die includes: a shape/residual stress immediately after springback acquisition step of acquiring a shape and a residual stress of the press formed part immediately after the springback by a springback analysis of the press formed part; a residual stress relaxation/reduction setting step of setting a value of a residual stress relaxed and reduced from the acquired residual stress to the press formed part immediately after the springback; and a shape analysis step of determining a shape, in which moments of force are balanced, for the press formed part to which the value of the relaxed and reduced residual stress is set.

A planar workpiece machining device has an upper tool and a lower tool that are movable toward each other in a reciprocation direction and in the opposite direction to machine a workpiece arranged therebetween. The upper tool has a clamping shaft, an upper main body, and a tool body arranged opposite the clamping shaft on the main body and having an upper bending edge. The lower tool has a lower main body, on which a counter tool body having a lower bending edge and a counter holder are provided. The lower bending edge is oriented facing the counter holder. The upper bending edge is stationary to the upper main body, and the lower bending edge is stationary to the lower main body. The upper bending edge is associated with an undercut on the tool body and the lower bending edge is associated with an undercut on the counter tool body.

A planar workpiece machining device has an upper tool and a lower tool that are movable toward each other in a reciprocation direction and in the opposite direction to machine a workpiece arranged therebetween. The upper tool has a clamping shaft, an upper main body, and a tool body arranged opposite the clamping shaft on the main body and having an upper bending edge. The lower tool has a lower main body, on which a counter tool body having a lower bending edge and a counter holder are provided. The lower bending edge is oriented facing the counter holder. The upper bending edge is stationary to the upper main body, and the lower bending edge is stationary to the lower main body. The upper bending edge is associated with an undercut on the tool body and the lower bending edge is associated with an undercut on the counter tool body.

A press mold for forming a panel, may include an upper die for vertically operating by an upper press, and having a mounting recess recessed upward at a lower surface central portion, a lower die disposed under the upper die, and configured to the vertically operate by a lower press, an upper pad disposed in a center portion of the mounting recess, and formed with an upper forming surface at a lower surface edge portion, a lower steel disposed under the upper pad, mounted on the lower die, and formed with a lower forming surface at an upper surface edge portion of the lower steel corresponding to the upper forming surface, and an upper steel mounted on the upper die at a position exterior to the lower forming surface.

A shape change prediction method for a press formed part predicts a shape change of the press formed part over time after springback at a moment of a release from a press-forming die, and includes: a shape/residual stress immediately after the springback acquisition step of acquiring a shape and a residual stress of the press formed part immediately after the springback by a springback analysis of the press formed part; a residual stress relaxation/reduction setting step of setting a value of a residual stress relaxed and reduced from the acquired residual stress to all bent portions or a part of the bent portions in the press formed part immediately after the springback; and a shape analysis step of determining a shape in which moments of force are balanced for the press formed part in which the value of the residual stress relaxed and reduced in the bent portions is set.

A forming device which expands a metal pipe material to form a metal pipe having a pipe portion and a flange portion includes first and second dies paired with each other and including pipe forming surfaces for forming the pipe portion and flange forming surfaces for forming the flange portion, a drive unit that drives at least one of the first and second dies, and a controller that controls the drive unit, in which, on at least one of the flange forming surfaces of the first and second dies, a protrusion portion protruding by an amount not to abut against the other flange forming surface when the dies are closed is formed and the controller controls the drive unit to form a thin wall portion at which a thickness of the flange portion becomes partially small at the flange portion by the protrusion portion pressing the flange portion.

Provided are a method of for machining the outer circumference of a metal end cross-section, the method being capable of easily forming at least any of a deep groove, a deep recess, and a flange which are smooth and uniform in the longitudinal direction of a metal rod or metal pipe in the periphery of the cross-section of any of the end part of the metal rod or metal pipe, the drawn end part of the metal rod or metal pipe, and the hub hole forming part of the metal pipe; and a method for joining a metal component obtained by the machining method with another member. The machining method of the present invention is characterized in that: splitting is advanced by successively repeating press forming operation multiple times by using a slitting punch, in which a tip part has a sharp cutting edge, and the cutting edge is formed so as to have a shape equal to or partly equal to the outer shape of the cross section of a metal end part and so as to have a diameter smaller than the outer diameter of the cross section of the splitting object; and in order to control the depth of metal cracking cleft created with each press forming operation, a pressing die for pinching the outside of a metal rod or at least a pressing die of one side of pressing dies for pinching the inside and the outside of a metal pipe is disposed while its position is moved according to the distance of a split portion.

Provided are a method of for machining the outer circumference of a metal end cross-section, the method being capable of easily forming at least any of a deep groove, a deep recess, and a flange which are smooth and uniform in the longitudinal direction of a metal rod or metal pipe in the periphery of the cross-section of any of the end part of the metal rod or metal pipe, the drawn end part of the metal rod or metal pipe, and the hub hole forming part of the metal pipe; and a method for joining a metal component obtained by the machining method with another member. The machining method of the present invention is characterized in that: splitting is advanced by successively repeating press forming operation multiple times by using a slitting punch, in which a tip part has a sharp cutting edge, and the cutting edge is formed so as to have a shape equal to or partly equal to the outer shape of the cross section of a metal end part and so as to have a diameter smaller than the outer diameter of the cross section of the splitting object; and in order to control the depth of metal cracking cleft created with each press forming operation, a pressing die for pinching the outside of a metal rod or at least a pressing die of one side of pressing dies for pinching the inside and the outside of a metal pipe is disposed while its position is moved according to the distance of a split portion.