Vehicle front body structure and method for manufacturing thereof

Patent metadata

Field	Value
Publication number	US-2018354560-A1
Application number	US-201615780522-A
Country	US
Kind code	A1
Filing date	Dec 9, 2016
Priority date	Dec 9, 2015
Publication date	Dec 13, 2018
Grant date	—

Abstract

The resistance to plastic deformation of the upper fender rail increases from the front end of the upper fender rail to the rear end of the upper fender rail. The yield strength of the material of the rear section is greater than the yield strength of the material of the front section and/or the rear section has a greater wall thickness than the wall thickness of the front section.

First claim

1 - 22 . (canceled)

23 . A vehicle front body structure comprising an upper longitudinal beam and a upper fender rail for supporting a fender of the vehicle, said upper fender rail extending in a longitudinal direction substantially parallel to the upper longitudinal beam and having a front end and a rear end spaced apart along the longitudinal direction, the rear end being attached to a front pillar of the vehicle and the upper fender rail extending towards the front of the vehicle from the rear end,
wherein he resistance to plastic deformation of the upper fender rail increases from the front end of the upper fender rail to the rear end of the upper fender rail, said upper fender rail comprising a front section and a rear section, the resistance to plastic deformation of the rear section being greater than the resistance to plastic deformation of the front section, and wherein the yield strength of the material of the rear section is greater than the yield strength of the material of the front section and/or the rear section has a greater wall thickness than the wall thickness of the front section.

24 . The vehicle front body structure according to claim 23 , wherein the product of the square of the wall thickness of the rear section by the yield strength of the rear section is greater than the product of the square of the wall thickness of the front section by the yield strength of the front section.

25 . The vehicle front body structure according to claim 23 , wherein the rear section comprises a front subsection and a rear subsection, the resistance to plastic deformation of the rear subsection being greater than the resistance to plastic deformation of the front subsection.

26 . The vehicle front body structure according to claim 23 , wherein the product of the square of the wall thickness of the rear subsection by the yield strength of the rear subsection is greater than the product of the square of the wall thickness of the front subsection by the yield strength of the front subsection.

27 . The vehicle front body structure according to claim 23 , wherein the yield strength of the material of the rear subsection is greater than the yield strength of the material of the front subsection and/or the rear subsection has a wall thickness that is greater than the wall thickness of the front subsection.

28 . The vehicle body structure according to claim 23 , wherein the front section is made of DP590 steel, the front subsection is made of DP780 steel and the rear subsection is made of DP980 steel.

29 . The vehicle body structure according to claim 23 , wherein the front section is a press-hardened steel part having, after press-hardening, a yield strength comprised between 360 and 400 MPa, the front subsection of the rear section is a press-hardened steel part having, after press-hardening, a yield strength comprised between 700 and 950 MPa and the rear subsection of the rear section is a press-hardened steel part having, after press-hardening, a yield strength comprised between 950 and 1200 MPa.

30 . The vehicle body structure according to claim 29 , wherein the front section is made of a press-hardenable steel having a carbon content comprised between 0.04 wt. % and 0.1 wt. % and a manganese content comprised between 0.3 wt. % and 2.0 wt. %, the front subsection of the rear section is made of a press-hardenable steel having a carbon content comprised between 0.06 wt. % and 0.1 wt. % and a manganese content comprised between 1.4 wt. % and 1.9 wt. %, and the rear subsection of the rear section is made of a press-hardenable steel having a carbon content comprised between 0.20 wt. % and 0.25 wt. % and a manganese content comprised between 1.1 wt. % and 1.4 wt. %.

31 . The vehicle body structure according to claim 23 , wherein the front section is a press-hardened steel part having, after press-hardening, a yield strength R e greater or equal to 600 MPa and the rear section is a press-hardened steel part having, after press-hardening, a yield strength greater or equal to 850 MPa.

32 . The vehicle body structure according to claim 23 , wherein the upper fender rail is entirely made of a press-hardenable steel having, after press-hardening, a yield strength comprised between 700 and 950 MPa, the wall thickness of the upper fender rail increasing from the front end to the rear end thereof.

33 . The vehicle body structure according to claim 31 , wherein the upper fender rail is made of a press-hardenable steel having a carbon content comprised between 0.06 wt. % and 0.1 wt. % and a manganese content comprised between 1.4 wt. % and 1.9 wt. %.

34 . The vehicle front body structure according to claim 23 , wherein the cross-sectional area of the front section is smaller than the cross-sectional area of the rear section.

35 . The vehicle front body structure according to claim 23 , wherein the length of the front section is smaller than the length of the rear section.

36 . The vehicle front body structure according to claim 23 , wherein the upper fender rail is a hollow tubular element.

37 . The vehicle front body structure according to claim 36 , wherein the upper fender rail is formed by the assembly of at least an inner half shell and an outer half shell assembled together along a longitudinal plane.

38 . The vehicle front body structure according to claim 37 , wherein the inner half shell and the outer half shell are obtained from tailor welded blanks.

39 . The vehicle front body structure according to claim 23 , further comprising a linking element joining the upper fender rail and the upper longitudinal beam.

40 . The vehicle front body structure according to claim 23 , wherein no crashbox is attached to the front end of the upper fender rail.

41 . The vehicle front body structure according to claim 23 , further comprising a transversal beam forming a bumper beam, attached to a front end of the upper longitudinal beam.

42 . The vehicle body comprising a vehicle front body structure according to claim 23 .

43 . A method for manufacturing a vehicle front body structure according to claim 23 , comprising a step of manufacturing an upper fender rail, said step comprising:
manufacturing of an inner half shell and an outer half shell; assembling together said inner half shell and said outer half shell along a longitudinal plane.

44 . The method according to claim 42 , wherein the step of manufacturing the inner half shell and the outer half shell comprises:
providing a tailor welded blank, the tailor welded blank being obtained by welding together at least as many blanks as there are portions having different thicknesses and/or compositions in the half-shell, each of these blanks having a thickness and/or a composition depending on the desired properties of the corresponding portion of the upper fender rail; and forming this tailor welded blank into the desired shape.

Assignees

• Arcelormittal

Inventors

• Viaux Ivan
• Drouadaine Yves

Classifications

• B62D25/08

  Front or rear portions {(sub-frames for mounting engine or suspensions B62D21/11)} · CPC title

• B62D29/007

  predominantly of special steel or specially treated steel, e.g. stainless steel or locally surface hardened steel · CPC title

• B62D25/082 Primary

  Engine compartments · CPC title

• B62D21/152

  Front or rear frames · CPC title

• B62D25/16 Primary

  Mud-guards or wings; Wheel cover panels (equipped with means for freeing wheels or tyres from foreign matter B60S) · CPC title