Abstract: A method for bending a sheet metal comprises: a hardness adjustment process wherein a blank (10), including a high-hardness region (11) and a low-hardness region (12) having a lower hardness than the high hardness region (11), is formed by changing the hardness of at least a part of a sheet metal; and a bending process wherein a product (20) is formed by bending low-hardness region (12) of blank (10).

Abstract: A structural hydroformed joint member has projecting portions (30a, 30b) formed integrally on an outer peripheral face of a hollow main tube part (20) by hydroforming an element tube with an outside diameter D. In this case, both intersecting planes (35a, 35b), which are projecting planes of end faces (33a, 33b) of the projecting portions (30a, 30b) toward the main tube part (20), share a plane perpendicular to the main axis (40) of the main tube part (20) only in portions (36a, 36b) of the intersecting planes (35a, 35b). At that time, by setting areas of the portions (36a, 36b) to 30% or more and 90% or less relative to an area of each of the intersecting planes (35a, 35b), a projecting height of each of the projecting portions (30a, 30b) is 0.3 D or higher for functioning as a joint.

Abstract: The present invention provides a hydroforming method able to increase the expansion ratio to obtain a complicated shape hydroformed product and able to reduce the number of steps of work, that is, a hydroforming method loading a metal pipe into a divided mold, clamping the mold, then applying an internal pressure and pushing force in the pipe axial direction to said metal pipe, comprising, in a first hydroforming step, expanding said metal pipe in one direction of said metal pipe cross-section to obtain an intermediate product having a circumferential length of 90% to 100% of the circumferential length of the product shape in all of the expanded part in the pipe axial direction and having a height greater than the height of the product in said one direction and at least part of the pipe axial direction, then, in a second hydroforming step, reducing the height in the one direction of said intermediate product in all or part of the pipe axial direction while shaping the product to the final product shape.

Abstract: The object is to raise the yield by greatly eliminating the disposed amounts of the tube ends, prevent wrinkles due to closing the mold while applying internal pressure, cutting the plurality of steps of hydroforming and pre-processing of the tube ends, cutting the mold costs by simplifying the mold mechanism, and obtaining a hydroformed product formed with a flange along its entire length.

Abstract: The invention has as its object to perform hydroforming so that no buckling or wrinkles remain at a hydroformed product with a long expanded region and comprises performing a first step of raising the internal pressure in a state with the metal tube fixed in position at the two ends or a state applying axial pushing actions of 10% or less of the total amount of axial pushing action, then applying axial pushing actions while holding the internal pressure at a constant pressure so as to expand the metal tube near the ends, then performing a second step of raising only the internal pressure without applying any axial pushing action so as to thereby expand a center of the metal tube, then performing a third step of lowering only the internal pressure to the value of the constant pressure without applying any axial pushing action, then repeating the first to third steps one or more times, then raising the internal pressure in the state not applying any axial pushing action or applying an axial pushing action of 10

Abstract: The object is to raise the yield by greatly eliminating the disposed amounts of the tube ends, prevent wrinkles due to closing the mold while applying internal pressure, cutting the plurality of steps of hydroforming and pre-processing of the tube ends, cutting the mold costs by simplifying the mold mechanism, and obtaining a hydroformed product formed with a flange along its entire length.

Abstract: A hydroformed product obtained by integrally working a metal pipe material by cold plastic working, which product (x) has a bent part at least at one location, (y1) has, at least at one location of the bent part, an expanded part of dimensions of a direction toward the outer side (or inner side) of the bend in a cross-section vertical to a pipe axis and a direction vertical to that direction of at least 1.35× of a circle equivalent diameter of an end of the metal pipe, and (z1) has an inner side (outer side) of the bent part of substantially the same radius of curvature.

Abstract: The present invention has its object to provide an efficient, general use shaping technique for when forming high strength sheet metal into a three-dimensionally complicated shape. Further, the present invention provides a working apparatus for shaping sheet metal comprising a die (10) (also called a “punch”) which has a shape suitable for a shape of shaped sheet metal, a plurality of rolls (30 to 33) which grip sheet metal (H) with the die to shape the sheet metal, roll movement mechanisms (40) which makes the rolls independently move in a horizontal direction and make them independently ascend or descend in a vertical direction, and a roll angle setting mechanism which can change an angle by which the rolls are pressed against the die.

Abstract: The present invention was made with the object of eliminating the short pipe member when attaching a bolting nut to a hydroformed part, preventing an increase in the difficulty of hydroforming for attaching the nut, extending the nut length so as to enable sufficient strength at the time of bolting, and enabling application even to thin wall hydroformed parts and comprises inserting a metal pipe into a split mold having a pierce punch able to be moved perpendicular to an axis of the inserted metal pipe or in a slanted direction, having a front part narrower than a center part, and having around the front part a nut having an inside diameter larger than an outside diameter of the front part and smaller than an outside diameter of the center part; hydroforming it; then making the pierce punch advance to pierce part of the hydroformed part and pushing the nut by a center part arranged behind the nut and embedding the nut in the metal pipe.

Abstract: A hydroforming apparatus and working method able to simply find a load path are proposed, which system and method use a mold in which contact sensors able to judge contact with a metal tube inside the mold are mounted at least at two different positions in the tube axial direction, perform a first step of axially pushing tube ends in a state with the internal pressure held at a constant value and stopping the progress of the axial pushing action when judging that among the contact sensors not yet in contact mounted at positions closest to the tube ends detect contact with the metal tube, next perform a second step of raising only the internal pressure while leaving the positions of the tube ends fixed and stopping the increase in the internal pressure when the contact sensor not yet in contact judges contact, next perform a third step of lowering the internal pressure to the value before raising it while leaving the positions of the tube ends fixed, and repeat said first step to third step until all of said c

Abstract: The invention has as its object to perform hydroforming so that no buckling or wrinkles remain at a hydroformed product with a long expanded region and comprises performing a first step of raising the internal pressure in a state with the metal tube fixed in position at the two ends or a state applying axial pushing actions of 10% or less of the total amount of axial pushing action, then applying axial pushing actions while holding the internal pressure at a constant pressure so as to expand the metal tube near the ends, then performing a second step of raising only the internal pressure without applying any axial pushing action so as to thereby expand a center of the metal tube, then performing a third step of lowering only the internal pressure to the value of the constant pressure without applying any axial pushing action, then repeating the first to third steps one or more times, then raising the internal pressure in the state not applying any axial pushing action or applying an axial pushing action of 10

Abstract: The object is to raise the yield by greatly eliminating the disposed amounts of the tube ends, prevent wrinkles due to closing the mold while applying internal pressure, cutting the plurality of steps of hydroforming and pre-processing of the tube ends, cutting the mold costs by simplifying the mold mechanism, and obtaining a hydroformed product formed with a flange along its entire length.

Abstract: A hydroformed product obtained by integrally working a metal pipe material by cold plastic working, which product (x) has a bent part at least at one location, (y1) has, at least at one location of the bent part, an expanded part of dimensions of a direction toward the outer side (or inner side) of the bend in a cross-section vertical to a pipe axis and a direction vertical to that direction of at least 1.35× of a circle equivalent diameter of an end of the metal pipe, and (z1) has an inner side (outer side) of the bent part of substantially the same radius of curvature.

Abstract: The present invention provides a hydroforming method able to increase the expansion ratio to obtain a complicated shape hydroformed product and able to reduce the number of steps of work, that is, a hydroforming method loading a metal pipe into a divided mold, clamping the mold, then applying an internal pressure and pushing force in the pipe axial direction to said metal pipe, comprising, in a first hydroforming step, expanding said metal pipe in one direction of said metal pipe cross-section to obtain an intermediate product having a circumferential length of 90% to 100% of the circumferential length of the product shape in all of the expanded part in the pipe axial direction and having a height greater than the height of the product in said one direction and at least part of the pipe axial direction, then, in a second hydroforming step, reducing the height in the one direction of said intermediate product in all or part of the pipe axial direction while shaping the product to the final product shape.

Abstract: The present invention was made with the object of eliminating the short pipe member when attaching a bolting nut to a hydroformed part, preventing an increase in the difficulty of hydroforming for attaching the nut, extending the nut length so as to enable sufficient strength at the time of bolting, and enabling application even to thin wall hydroformed parts and comprises inserting a metal pipe into a split mold having a pierce punch able to be moved perpendicular to an axis of the inserted metal pipe or in a slanted direction, having a front part narrower than a center part, and having around the front part a nut having an in side diameter larger than an outside diameter of the front part and smaller than an outside diameter of the center part; hydroforming it; then making the pierce punch advance to pierce part of the hydroformed part and pushing the nut by a center part arranged behind the nut and embedding the nut in the metal pipe.

Abstract: The present invention provides a new bending apparatus and bending method of a tube material which makes it possible to achieve all of bending by a large bending radius not requiring large scale equipment or die, bending resistant to wrinkling and buckling at an inner side of the bending, and bending with a high productivity, that is, a ram bending apparatus using a punch 12 and a set of rolls 13, 13 for three-point bending of a tube material wherein the punch 12 has a groove 12a of a width of the width of a circular tube 11 or more and wherein the set of rolls 13, 13 are supported by a frame 14. The rolls 13, 13 can freely move on the frame 14 in directions away from each other in a state contacting the punch 12. The frame 14 has a hollow space 14a enabling free movement of the descending punch 12 and the circular tube 11 bent along with this during the bending of the circular tube 11.