A method for the joining of hollow profiles made from high-strength steel, in particular to form a motor vehicle frame, the hollow profiles being connected to one another, nonpositively and positively against being pulled out, by pinching (crimping) in a connection zone, one end of at least one of the hollow profiles having a connection zone for pinching which is soft at least during forming. This soft connection zone may be hardened during pinching if at least one of the profiles to be joined is made from hardenable steel and is brought to austenizing temperature before pinching.

A load-bearing structure of a motor vehicle, having hollow profiles and junction elements to connect the hollow profiles. The hollow profiles may be fastened in receptacles of the junction elements, and the junction elements may have a plurality of areal webs in a vehicle vertical direction, at least some of the areal webs forming a framework structure which assists the load path in the respective junction element.

A composite structure includes: a cover plate having a countersunk hole and a plate side fitting hole; a bearing plate having a screw hole and a screw side fitting hole located opposite from the plate side fitting hole through the screw hole; and a plate screw component including a screw part engaged with the screw hole, and a plate side fitting part and a screw side fitting part respectively fitted with the plate side fitting hole and the screw side fitting hole to be in alignment with each other. A difference a in diameter between the plate side fitting hole and the plate side fitting part, a difference b in diameter between the screw side fitting hole and the screw side fitting part, and an effective difference c in diameter between the screw hole and the screw part satisfy a dimensional relation of a<c and b<c.

Provided are a method for splitting longitudinally an end part of a metal plate or a metal rod having a rectangular, polygonal, or elliptical shape, in which the length of incision in the split portion can be freely adjusted and smooth split face can be formed; a metal part manufactured by such method; and a method for bonding such metal part. The present invention is characterized by the process comprising the steps of securing a metal plate by pinching both sides thereof with a clamping device, or securing a metal rod by pinching at least two opposite-facing portions on the periphery thereof with a clamping device; splitting longitudinally by slitting or cleaving the metal plate, or the metal rod, by pressing a slitting punch or a cleaving punch against the face of one end of the metal plate, or the metal rod; and advancing the splitting further by repeating the same operation of pressing the same punch stated above against the cleft of the splitting; and is characterized further in that, in each time of the press-splitting operation, the position of the clamping device on at least one side is moved in advance of the next pressing by a stroke corresponding to the distance from one end of the metal plate, or the metal rod, to the distal end of a split-desired portion.

A method of manufacturing a vehicle frame body, the method includes: a placement process of placing a reinforcing member at a portion of a frame member, the portion being located in a length direction of the frame member and within the frame member, the frame member being a single member having an elongated shape and configuring a chamber structure; and, after the placement process, a bending process of bending the frame member at a placement region of the reinforcing member, causing reaction force to be generated by the reinforcing member against the frame member undergoing cross-sectional deformation, and pressure joining the reinforcing member to the frame member.

A swaging structure for which swaging process is easy, generation of wrinkles can be prevented, and which has high pressure-resistant performance is provided. In a swaging structure including at least a to-be-swaged member required to have airtightness to a surrounding environment and a swaging member constituted to retain the to-be-swaged member by a swaging processing, the swaging member has an annular side wall surrounding the to-be-swaged member, and a groove is formed in the annular side wall.

Provided are a method for splitting longitudinally an end part of a metal plate or a metal rod having a rectangular, polygonal, or elliptical shape, in which the length of incision in the split portion can be freely adjusted and smooth split face can be formed; a metal part manufactured by such method; and a method for bonding such metal part. The present invention is characterized by the process comprising the steps of securing a metal plate by pinching both sides thereof with a clamping device, or securing a metal rod by pinching at least two opposite-facing portions on the periphery thereof with a clamping device; splitting longitudinally by slitting or cleaving the metal plate, or the metal rod, by pressing a slitting punch or a cleaving punch against the face of one end of the metal plate, or the metal rod; and advancing the splitting further by repeating the same operation of pressing the same punch stated above against the cleft of the splitting; and is characterized further in that, in each time of the press-splitting operation, the position of the clamping device on at least one side is moved in advance of the next pressing by a stroke corresponding to the distance from one end of the metal plate, or the metal rod, to the distal end of a split-desired portion.

A swaging structure for which swaging process is easy, generation of wrinkles can be prevented, and which has high pressure-resistant performance is provided. In a swaging structure including at least a to-be-swaged member required to have airtightness to a surrounding environment and a swaging member constituted to retain the to-be-swaged member by a swaging processing, the swaging member has an annular side wall surrounding the to-be-swaged member, and a groove is formed in the annular side wall.

An optimized connection structure includes: pipe fittings (1) which is provided with radial through holes (13) about the periphery of the connecting part, multifunctional plugs (2, 20) which include: a plugging body (21) at the tail end, a groove (23) in the middle, and a large and a small positioning steps (22, 24) arranged in the inner holes of the tail ends of the pipe fittings (1), and a connecting member (3) which may be of a cast/forged composite structure, wherein an inner layer and an outer layer of metal rings (42, 41) and a plurality of radial and axial metal posts (43, 44) connecting the pipe fittings (1).

A load-bearing structure of a motor vehicle, having hollow profiles and junction elements to connect the hollow profiles. The hollow profiles may be fastened in receptacles of the junction elements, and the junction elements may have a plurality of areal webs in a vehicle vertical direction, at least some of the areal webs forming a framework structure which assists the load path in the respective junction element.