Rear underfloor structure for a motor vehicle

Patent metadata

Field	Value
Publication number	US-2023415822-A1
Application number	US-202118034747-A
Country	US
Kind code	A1
Filing date	Nov 4, 2021
Priority date	Nov 6, 2020
Publication date	Dec 28, 2023
Grant date	—

Abstract

Rear underfloor structure ( 2 ) for a motor vehicle ( 1 ) including a first and a second side member ( 4 ) and at least one cross member ( 5 ) linking the first and second side members ( 4 ), wherein the rear underfloor structure ( 2 ) is made by stamping a single tailor welded blank ( 26 ) comprising at least two sub-blanks.

First claim

What is claimed is:

1 - 16 . (canceled)

17 : A rear underfloor structure for a motor vehicle, the rear underfloor structure comprising:
a first and a second side member and at least one cross member linking the first and second side members, wherein the rear underfloor structure is made by stamping a single tailor welded blank including at least two sub-blanks.

18 : The rear underfloor structure as recited in claim 17 wherein the stamping is a hot stamping.

19 : The rear underfloor structure as recited in claim 17 wherein the at least one cross member includes at least two cross members.

20 : The rear underfloor structure as recited in claim 17 wherein each of the first and second side members includes:
a horizontal wall and an inner wall linked by an inner radius,
at least one cross-member attachment zone, corresponding to a portion of the first or second side member on to which the corresponding cross-member is attached,
wherein the inner radius extends along at least part of the cross-member attachment zone.

21 : The rear underfloor structure as recited in claim 17 wherein at least one of the at least two sub-blanks is coated with an aluminum based metallic coating.

22 : The rear underfloor structure as recited in claim 17 wherein at least one of the at least two sub-blanks is coated with an aluminum based metallic coating, comprising from 2.0 to 24.0% by weight of zinc, from 1.1 to 12.0% by weight of silicon, optionally from 0 to 8.0% by weight of magnesium, and optionally additional elements chosen from Pb, Ni, Zr, or Hf, the content by weight of each additional element being inferior to 0.3% by weight, a balance being aluminum and optionally unavoidable impurities.

23 : The rear underfloor structure as recited in claim 17 wherein at least one of the at least two sub-blanks includes an emissivity increasing top layer on at least one side.

24 : The rear underfloor structure as recited in claim 17 wherein at least one of the at least two sub-blanks is made of a press-hardening steel having an ultimate tensile strength after hot stamping above 1800 MPa.

25 : The rear underfloor structure as recited in claim 17 wherein at least one of the at least two sub-blanks is made of a press-hardening steel having a yield strength after hot forming comprised between 700 and 950 MPa, an ultimate tensile strength after hot forming comprised between 950 MPa and 1200 MPa and a bending angle after hot forming above 75°.

26 : The rear underfloor structure as recited in claim 17 further comprising at least one metallic patch.

27 : The rear underfloor structure as recited in claim 26 wherein the at least one metallic patch includes an emissivity increasing top layer.

28 : The rear underfloor structure as recited in claim 17 further comprising at least one weld seam reinforcing patch applied on an area having a weld seam.

29 : The rear underfloor structure as recited in claim 28 wherein the at least one weld seam reinforcing patch includes an emissivity increasing top layer.

30 : The rear underfloor structure as recited in claim 17 wherein a thickness of an interdiffusion layer in an Aluminum based metallic coated area of the rear underfloor structure is between 3 microns and 15 microns.

31 : The rear underfloor structure as recited in claim 30 wherein the thickness is between 3 microns and 10 microns.

32 : A motor vehicle comprising the rear underfloor structure as recited in claim 17 .

Assignees

• Arcelormittal

Inventors

• Hasenpouth Dan
• Moriau Olivier

Classifications

• B62D29/007

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

• B62D25/20 Primary

  Floors or bottom sub-units {(sub-frames for mounting engine or suspensions B62D21/11; drip trays F16N31/006)} · CPC title

• B62D25/2027 Primary

  the subunits being rear structures · CPC title

• B62D27/02

  rigid · CPC title

• B62D29/008

  predominantly of light alloys, e.g. extruded · CPC title