A door of a vehicle may include a door internal panel; a door external panel mounted outside a passenger compartment with respect to the door internal panel, detachably coupled to the door internal panel, and made of a lightweight material than the door internal panel; and a reinforcement member mounted between the door external panel and the door internal panel and fastened to the door external panel and the door internal panel to increase rigidity, reducing weight and cost of the door of the vehicle and easily replacing the door external panel.

A steel composition, a reinforcement part of a vehicle using the steel composition and a method of manufacturing the reinforcement part using the steel composition are provided. In particular, the steel composition includes increased content of carbon components and the steel composition is processed by rapid heating and immediate quenching.

A door of a vehicle may include a first door module forming a door skeleton; and a second door module coupled with the first door module and forming a door window, wherein the second door module includes a relatively lightweight material as compared to the first door module; and a reinforcement member is along an edge portion forming the door window of the second door module, reducing weight and cost of the door for the vehicle.

A stiffening structure for an automotive door panel part according to the present invention includes a door outer panel 3 made of a metal sheet curved along a height direction, and in which a character line 3a is formed; and an impact beam 5 disposed at an inner surface side of the door outer panel 3. The stiffening structure improves tensile rigidity of the door outer panel 3 by attaching a stiffening member 7 made of resin to the inner surface of the door outer panel 3. The stiffening member 7 includes vertical bone portions 9 extending in a streak shape from the impact beam 5 to the character line 3a along a curve of the door outer panel 3. The vertical bone portions 9 are arranged at a predetermined interval in a front-rear direction of the door outer panel 3, and outer surface of the vertical bone portions 9 is bonded to the inner surface of the door outer panel 3.

A vehicle door according to an exemplary embodiment enhances coupling strength through structural coupling by molding a window frame of a door module assembled between a door trim and the door panel with a separate aluminum injection product, and insert-injection molding a coupling portion of the window frame to a module body, and a groove is formed along the coupling portion of the window frame coupled to the module body to easily distinguish respective parts and serve to carry out sealing in injection molding.

There are provided a vehicle-body frame member forming an opening portion for entrance at a vehicle side part and a front side door provided so as to open and close the opening portion. The vehicle-body frame member comprises a side sill, the front side door comprises a door panel portion provided with an inner lower portion which overlaps with the side sill in a vehicle wide view and reinforcement portions provided at three side-portions of a peripheral part of the door panel portion which are continuous and include the inner lower portion such that the reinforcement portions overlap with the vehicle-body frame member in a vehicle side view.

A side door comprises a door panel portion and a reinforcement portion (a rear-side reinforcement portion and others). The reinforcement portion is provided at at least one of a corner portion positioned between a lower portion and a front-side portion of a peripheral part of the door panel portion and another corner portion positioned between the lower portion and a rear-side portion of the peripheral part of the door panel portion such that the reinforcement portion overlaps with a vehicle-body frame member in a vehicle side view. The reinforcement portion is provided with a curved portion at an inside part of the corner portion where the reinforcement portion is provided. The curved portion is configured to be curved convexly toward an outside part of the corner portion in the vehicle side view.

A method includes molding an outer impact beam made of carbon fiber reinforced plastics (CFRP) and separately molding an inner impact beam made of CFRP. The outer impact beam and the inner impact beam are coupled to each other to form an impact beam and the impact beam is coupled to an inner panel of a vehicle door.

A vehicle door assembly includes an inner door panel, an outer door panel and an energy absorbing member. The outer door panel being configured such that at least a portion of an outer periphery thereof is fixed to an outer periphery of the inner door panel, the inner door panel and the outer door panel defining a hollow interior therebetween. The hollow interior has an upper end and a lower end. The energy absorbing member is installed within the hollow interior between the inner door panel and the outer door panel. The energy absorbing member has an outboard end surface with a first predetermined surface area and an inboard end surface having a second predetermined surface area greater than the first predetermined surface area. The energy absorbing member is spaced apart from the upper end of the hollow interior and being spaced apart from the lower end of the hollow interior.

A vehicle side body structure having a pillar member including an upper member and a lower member that is joined to the upper member and has a rigidity lower than the upper member, the pillar member partitioning a side part opening of a body into a front part and a rear part; a side door disposed adjacently to the pillar member; and an impact bar provided in the side door, in which a front end portion of the impact bar overlaps with both the upper and lower members in side view while the side door is closed. The upper member has a reinforcing member and the front end portion of the impact bar covers a region of the upper member in which the reinforcing member is present, a region of the upper member in which the reinforcing member is not present, and the lower member in side view.