Abstract: A joint structure includes an extrudate member and an elongated mating member, in which the extrudate member has a closed sectional structure portion and has its one end joined to the elongated mating member such that the longitudinal axis of the extrudate member intersects the longitudinal axis of the elongated mating member. The one end of the extrudate member includes an integral joint portion of a shape matched to the shape of an outer surface of the mating elongated member so as to encircle at least a portion of the elongated mating member. The joint portion is bonded to the outer surface of the mating member at its longitudinally intermediate portion by brazing, spot-welding or the like.

Abstract: The first and second weld areas of respective first and second metallic workpieces of aluminum or aluminum alloy are held in abutment against each other with a surface of the second metallic workpiece being positioned on a positioning guide of the first metallic workpiece. A recess is defined between the positioning guide and the second metallic workpiece. A high-density energy beam such as a laser beam is applied to the first and second weld areas thereby to develop a molten pool therein that grows toward the positioning guide until metallic oxide films formed on the first and second metallic workpieces are forced into the recess by the molten pool. As no metallic oxide films are present in a weld joint between the first and second metallic workpieces, the resultant welded structure is of a high mechanical strength.

Abstract: After a predeoxidation treatment of a molten steel comprising as basic ingredients, in terms of % by weight, 0.04 to 0.20% of C, 0.05 to 0.50% of Si, 0.4 to 2.0% of Mn, 0.3 to 0.7% of Mo, 0.003 to 0.015% of N, 0.04 to 0.20% of V and less than 0.005% of Al to regulate [O %] to 0.003 to 0.015% by weight, titanium is added thereto so as to satisfy a requirement represented by the formula: -0.006.ltoreq.[Ti %]-2[O %].ltoreq.0.008 to crystallize a titanium-based oxide in an amount of 20 particles/mm.sup.2 or more, and MnS, TiN and V(C, N) are deposited on the titanium-based oxide to disperse the titanium-based oxide as a composite precipitate in the steel to provide a cast slab, and a high-strength high-toughness shape steel having an excellent fire resistance is provided by a combination of water cooling between rolling passes at the time of rolling with accelerated cooling after the completion of the rolling.

Abstract: A cast strip for an H-shape steel having excellent fire resistance and toughness for use as a structural member for constructions and a shape steel having a flange, such as an I-shape steel, produced by accelerated cooling and controlled rolling of the cast slab, are produced in an in-line manner.After the regulation of the oxygen concentration of a molten steel by a predeoxidation treatment in a steel making process to form a steel having predetermined ingredients, the steel is subjected to final deoxidation with a minor amount of Al to provide a cast slab containing, in a dispersed state, compound oxide precipitate having a capability of forming intragranular ferrite. The stead is then subjected to a treatment comprising a combination of water cooling between rolling passes with accelerated cooling after hot rolling to attain refinement of the structure and a low alloy steel, thereby improving the strength at room temperature and at high temperature and the toughness.

Abstract: A motor vehicle body structure has a pair of side frames each comprising a core layer having opposite surfaces and a pair of outer skin layers covering the opposite surfaces, a motor vehicle component, and joints disposed between the side frames and the motor vehicle component, for joining the motor vehicle component to the side frames through surface-to-surface contact therebetween.

Abstract: A joint structure includes a sandwiched structural body comprising a core layer having opposite surfaces and a pair of first and second outer skin layers covering the opposite surfaces, respectively, and a substantially concave joint region defined in the first outer skin layer and comprising a side wall and a bottom wall contiguous to the side wall, the bottom wall being joined to the second outer skin layer. The side wall of the joint region is of a tapered shape. The sandwiched structural body is formed primarily of synthetic resins, and may additionally include reinforcing fibers.

Abstract: A power unit mounting structure in a motor vehicle includes a power unit comprising an engine having a crankshaft, a transmission coupled to the crankshaft of the engine, and a differential interposed between drive axles connected to a pair of laterally spaced front road wheels of the motor vehicle and the transmission. The power unit is mounted in a front portion of the motor vehicle with its center of gravity positioned rearwardly of the drive axles extending from the differential toward front road wheels serving as the drive road wheels. A steering gearbox extends parallel to the drive axles and is disposed forwardly of the drive axles.

Abstract: The part-mounting structure of the present invention includes a part-mounting portion of a sandwich structure constituted by a core layer and plastic skin layers formed on both surfaces of the core layer, and a part-mounting metal member, at least one of the skin layers having a tapered recess having a sloped side wall and a flat bottom wall, the bottom wall being constituted by the skin layers bonded together, the part-mounting metal member having a bottom plate, and a pair of side plates vertically extending from the bottom plate substantially on both sides, at least one of the side plates having a dent tapered complementarily to the tapered recess of the sandwich structure. The part-mounting metal member is mounted to the part-mounting portion of the sandwich structure with a surface of the tapered recess of the sandwich structure and a surface of the tapered dent of the part-mounting metal member bonded together by an adhesive.

Abstract: An automobile body structure includes a canopy of plastic having a pair of thicker portions projecting on an inner surface of the canopy and spaced from each other in the fore-and-aft direction of the automobile body structure, and a rigid support member embedded in each of the thicker portions. The canopy includes a roof, and front and rear windows formed therewith of a unitary, undivided construction, the thicker portions being disposed near upper edges of the front and rear windows. The thicker portions are arch-shaped. The rigid support member comprises a solid rod or a hollow pipe.

Abstract: An elongate packing is sandwiched between two sheet-like mold members in an encircling manner to define a mold cavity therebetween, then a thermosetting plastic material is poured into the mold cavity, and the thermosetting plastic material is heated and set in the mold cavity. The upper and lower mold members are held against deformation transverse thereof so as not to be deformed by the shrinkage of the thermosetting plastic material when the latter is set, and the packing is allowed to move transversely thereof for following the shrinkage of the thermosetting plastic material when the latter is set. In some embodiments, the packing comprises a packing body adapted to be sandwiched between the mold members for preventing the plastic material from flowing out of the mold cavity with a flange joined to the packing body and adapted to be held against peripheral edges of the mold members.