Abstract: Disclosed is a joining method of members, which includes the steps of: preparing a first member in which a first hole portion having a polygonal cross-sectional shape is formed, and a second member having a hollow shape, wherein the second member has a cross-sectional shape corresponding to the polygonal cross-sectional shape of the first hole portion, the second member including a plurality of straight line portions extending linearly and corner portions positioned between the adjacent two straight line portions in the cross-sectional shape; inserting the second member into the first hole portion of the first member; and caulking and joining the second member to the first member by enlarging and deforming the corner portions.

Abstract: In a method for joining bumper members, a bumper reinforcement including a rear inclined wall provided with a hole, and a bumper stay in a hollow shape are prepared. The method for joining bumper members includes the steps of: inserting the bumper stay through the hole of the bumper reinforcement to pass through the rear inclined wall; inserting rubber into the bumper stay; and compressing the rubber in a direction of an axis L of the bumper stay to expand the rubber outward from inside to expand and deform at least a portion of the bumper stay inserted into the hole, thereby joining the bumper stay to the rear inclined wall by press-fitting.

Abstract: A joining method for members includes: providing a steel component 10 including insertion holes 14a and 15a, an aluminum pipe 20 having a hollow shape, and a support component 30; inserting the aluminum pipe 20 into the insertion holes 14a and 15a of the steel component 10; and enlarging the aluminum pipe 20 through deformation and joining the aluminum pipe 20 to the steel component 10 by press-fitting. The press-fit joining is performed while at least part of the support component 30 is disposed in a press-fitting region.

Abstract: A steel sheet for hot pressing includes in a chemical composition, in percent by mass, C of 0.1% to 0.4%, Si of greater than 0% to 2.0%, Mn of 0.5% to 3.0%, P of greater than 0% to 0.015%, S of greater than 0% to 0.01%, B of 0.0003% to 0.01%, N of greater than 0% to 0.05%, Al in a content of 2×[N]% to 0.3% at a Si content of greater than 0.5% to 2.0%; or Al in a content of (0.20+2×[N]?0.40×[Si]N)% to 0.3% at a Si content of 0% to 0.5%, where [N] and [Si] are contents of N and Si, respectively, in mass percent, with the remainder being iron and inevitable impurities, where contents of Ti, Zr, Hf, and Ta, of the inevitable impurities, are each controlled to 0.005% or lower. The steel sheet includes nitride-based inclusions with an equivalent circle diameter of 1 ?m or more in a number density of 0.10 per square millimeter.

Abstract: The joining method for members according to the present invention includes: providing an aluminum component including an insertion hole provided with a rib in at least part of an edge part, and a hollow steel pipe; inserting the steel pipe into the insertion hole of the aluminum component; and expanding and deforming the steel pipe to join the steel pipe to the aluminum component by press-fitting.

Abstract: A joining method for members according to the present invention includes: providing a steel component including insertion holes, an aluminum pipe having a hollow shape, and a support component; inserting the aluminum pipe into the insertion holes of the steel component; and enlarging the aluminum pipe through deformation and joining the aluminum pipe to the steel component by press-fitting. The press-fit joining is performed while at least part of the support component is disposed in a press-fitting region.

Abstract: Structure including joint structure of dissimilar materials comprises a roof panel and a skeletal body. The roof panel has a bent portion at its end and is a panel member made of an aluminum alloy. The skeletal body has a support portion for supporting the first member and is made of steel. The roof panel and the skeletal body are joined by continuous welding of a vicinity of an apex of the bent portion of the roof panel and the support portion of the skeletal body, a reinforcing plate is joined to the roof panel at least partially along the joining portion with the skeletal body.

Abstract: A vehicle front structure includes a front side member extending in a vehicle front-rear direction in a front portion of a vehicle body, an upper side member disposed above the front side member in a vehicle and extending in the vehicle front-rear direction, and a suspension tower joined to the front side member and the upper side member. The suspension tower is made of aluminum alloy integrally formed by press working. The vehicle front structure is capable of being reduced in weight and being more easily manufactured without introducing new equipment.

Abstract: A steel sheet for hot-pressing includes a specific chemical component composition. In the steel sheet, an average equivalent-circle diameter of a Ti-containing precipitate having an equivalent-circle diameter of 30 nm or less among Ti-containing precipitates contained in the steel sheet is 3 nm or more. A precipitated Ti amount and a total Ti amount in the steel satisfy the relationship of: Precipitated Ti amount (mass %)?3.4[N]?0.5×[(total Ti amount (mass %))?3.4[N]], in which [N] indicates the content (mass %) of N in the steel. A ferrite fraction in the metal microstructure of the steel sheet is 30 area % or more.

Abstract: In the present invention, a method for joining members involves preparing a steel component having a bottom wall in which a hole is provided, and a hollow aluminum pipe. The aluminum pipe is slipped through the hole in the steel component and passed through the bottom wall, rubber is inserted into the interior of the aluminum pipe, and the rubber is compressed in the direction of the axis (L) of the aluminum pipe and induced to distend towards the outside from the inside. As a result of the foregoing, at least a section of the aluminum pipe slipped through the hole is induced to undergo expansion and is joined by clinching to the bottom wall. This method for joining members reduces the load on the members, improves the joint strength, and enables two members to be joined at reduced cost.

Abstract: In the present invention, a method for joining members involves preparing a steel component having a bottom wall in which a hole is provided, and a hollow aluminum pipe. The aluminum pipe is slipped through the hole in the steel component and passed through the bottom wall, rubber is inserted into the interior of the aluminum pipe, and the rubber is compressed in the direction of the axis (L) of the aluminum pipe and induced to distend towards the outside from the inside. As a result of the foregoing, at least a section of the aluminum pipe slipped through the hole is induced to undergo expansion and is joined by clinching to the bottom wall. This method for joining members reduces the load on the members, improves the joint strength, and enables two members to be joined at reduced cost.

Abstract: A manufacturing method of a press-formed article includes arranging a member to be pressed between first and second dies, and relatively moving the first and second dies so as to approach each other, thereby press forming to a portion to be pressed so that a height of the portion to be pressed decreases. In the press forming step, while first bent portions in a pair each bent in a protruded shape toward the second die on the portion to be pressed are held by groove-shaped holding portions in a pair separated from each other on the second die, a second bent portion bent in a protruded shape from a position between the first bent portions toward the first die on the portion to be pressed is pressed and deformed by a pressing portion of the first die.

Abstract: Disclosed is a joining method of members, which includes the steps of: preparing a first member in which a first hole portion having a polygonal cross-sectional shape is formed, and a second member having a hollow shape, wherein the second member has a cross-sectional shape corresponding to the polygonal cross-sectional shape of the first hole portion, the second member including a plurality of straight line portions extending linearly and corner portions positioned between the adjacent two straight line portions in the cross-sectional shape; inserting the second member into the first hole portion of the first member; and caulking and joining the second member to the first member by enlarging and deforming the corner portions.

Abstract: The joining method for members according to the present invention includes: providing an aluminum component including an insertion hole provided with a rib in at least part of an edge part, and a hollow steel pipe; inserting the steel pipe into the insertion hole of the aluminum component; and expanding and deforming the steel pipe to join the steel pipe to the aluminum component by press-fitting.

Abstract: A steel sheet for hot pressing includes in a chemical composition, in percent by mass, C of 0.1% to 0.4%, Si of greater than 0% to 2.0%, Mn of 0.5% to 3.0%, P of greater than 0% to 0.015%, S of greater than 0% to 0.01%, F3 of 0.0003% to 0.01%, N of greater than 0% to 0.05%, Al in a content of 2×[N]% to 0.3% at a Si content of greater than 0.5% to 2.0%; or Al in a content of (0.20+2×[N]-0.40×[Si]N)% to 0.3% at a Si content of 0% to 0.5%, where [N] and [Si] are contents of N and Si, respectively, in mass percent, with the remainder being iron and inevitable impurities, where contents of Ti, Zr, Hf, and Ta, of the inevitable impurities, are each controlled to 0.005% or lower. The steel sheet includes nitride-based inclusions with an equivalent circle diameter of 1 ?m or more in a number density of 0.10 per square millimeter.

Abstract: A manufacturing method of press-molded article of the present invention comprises a step of placing a member to be pressed in a press molding apparatus and a step of pressing a flat plate portion of the member to be pressed by bringing a first press portion and a second press portion closer to each other. A first opposing surface and a second opposing surface, while facing to each other, keep in contact with the flat plate portion during pressing. In the press step, a thick part is formed on the flat plate portion by allowing a part of a material of the flat plate portion to flow, in a press direction, into a thickened portion-forming section formed on the first opposing surface. The second opposing surface is moved to the press direction as the flat plate portion is pressed by the first press portion and the second press portion.

Abstract: A steel sheet for hot pressing use according to the present invention has a specified chemical component composition, wherein some of Ti-containing precipitates contained in the steel sheet, each of which having an equivalent circle diameter of 30 nm or less, have an average equivalent circle diameter of 3 nm or more, the precipitated Ti amount and the total Ti amount in the steel fulfill the relationship represented by formula (1) shown below, and the sum total of the fraction of bainite and the fraction of martensite in the metal microstructure is 80 area % or more. Precipitated Ti amount (mass %)?3.4[N]>0.5×[total Ti amount (mass %)?3.4[N]]??(1) (In the formula (1), [N] represents the content (mass %) of N in the steel.

Abstract: A vehicle front structure includes a front side member extending in a vehicle front-rear direction in a front portion of a vehicle body, an upper side member disposed above the front side member in a vehicle and extending in the vehicle front-rear direction, and a suspension tower joined to the front side member and the upper side member. The suspension tower is made of aluminum alloy integrally formed by press working. The vehicle front structure is capable of being reduced in weight and being more easily manufactured without introducing new equipment.

Abstract: A method for joining members of the present invention is as follows: a second member is inserted through a hole part of a first member; a guide shaft is inserted through a through hole of rubber; the rubber with the guide shaft inserted is inserted into the second member; and a drive mechanism relatively moves pushers and toward each other to compress the rubber in the extending direction of the guide shaft so that the rubber is expanded outward from inside to expand and deform at least a portion of the second member inserted into the hole part, thereby joining the second member to the first member.

Abstract: In a method for joining bumper members, a bumper reinforcement including a rear inclined wall provided with a hole, and a bumper stay in a hollow shape are prepared. The method for joining bumper members includes the steps of: inserting the bumper stay through the hole of the bumper reinforcement to pass through the rear inclined wall; inserting rubber into the bumper stay; and compressing the rubber in a direction of an axis L of the bumper stay to expand the rubber outward from inside to expand and deform at least a portion of the bumper stay inserted into the hole, thereby joining the bumper stay to the rear inclined wall by press-fitting.