Longitudinal member for a heavy goods vehicle

Patent metadata

Field	Value
Publication number	US-10780922-B2
Application number	US-201716306653-A
Country	US
Kind code	B2
Filing date	Jun 2, 2017
Priority date	Jun 3, 2016
Publication date	Sep 22, 2020
Grant date	Sep 22, 2020

Abstract

A longitudinal member is provided. The longitudinal member includes a front end provided with a hinge element for attaching the longitudinal member in an articulated manner to a heavy goods vehicle body, and a rear end including an attachment element for attaching the longitudinal member in a non-permanent manner to the heavy goods vehicle body. The longitudinal member includes a front part extending from the front end to an intermediate area of the longitudinal member and a rear part extending from the intermediate area to the rear end of the longitudinal member. The product (PF) of the wall thickness (tF) of the front part by the yield strength (YsF) of the material of the front part is greater than the product (PR) of the wall thickness (tR) of the rear part by the yield strength (YsR) of the material of the rear part.

First claim

What is claimed is:

1. A longitudinal member for a heavy goods vehicle structure, the longitudinal member comprising:
a front end, for being oriented towards a front of the heavy goods vehicle structure, the front end having a hinge element for attaching the longitudinal member in an articulated manner to a heavy goods vehicle body;
a rear end, for being oriented towards a rear of the heavy goods vehicle structure, the rear end having an attachment element for attaching the longitudinal member in a non-permanent manner to the heavy goods vehicle body;
a front part extending from the front end to an intermediate area of the longitudinal member;
a rear part extending from the intermediate area to the rear end of the longitudinal member; and
a product of a wall thickness of the front part by a yield strength of a material of the front part is greater than a product of a wall thickness of the rear part by a yield strength of a material of the rear part.

2. The longitudinal member according to claim 1 , wherein the wall thickness of the front part is from 0.6 mm to 3 mm and the yield strength of the material of the front part is from 960 MPa to 1550 MPa.

3. The longitudinal member according to claim 1 , wherein the wall thickness of the rear part is from 0.6 mm to 3 mm and the yield strength of the material of the rear part is from 350 MPa to 950 MPa.

4. The longitudinal member according to claim 1 , wherein the wall thickness of the front part is greater than the wall thickness of the rear part.

5. The longitudinal member according to claim 1 , wherein the longitudinal member is a press hardened member.

6. The longitudinal member according to claim 1 , wherein the front part is made of a press hardened steel comprising in % weight:
0.15%≤C≤0.5%, 0.5%≤Mn≤3%, 0.1%≤Si≤1%, 0.005%≤Cr≤1%, Ti≤0.2%, Al≤0.1%, S≤0.05%, P≤0.1%, B≤0.010%, the remainder being iron and unavoidable impurities resulting from the elaboration; or
0.20%≤C≤0.25%, 1.1%≤Mn≤1.4%, 0.15%≤Si≤0.35%, Cr≤0.30%, 0.020%≤Ti≤0.060%, 0.020%≤Al≤0.060%, S≤0.005%, P≤0.025%, 0.002%≤B≤0.004%, the remainder being iron and unavoidable impurities resulting from the elaboration; or
0.24%≤C≤0.38%, 0.40%≤Mn≤3%, 0.10%≤Si≤0.70%, 0.015%≤Al≤0.070%, Cr≤2%, 0.25%≤Ni≤2%, 0.015%≤Ti≤0.10%, Nb≤0.060%, 0.0005%≤B≤0.0040%, 0.003%≤N≤0.010%, S≤0.005%, P≤0.025%, a remainder being iron and unavoidable impurities resulting from elaboration.

7. The longitudinal member according to claim 1 , wherein the rear part is made of a press hardened steel comprising in % weight: 0.04%≤C≤0.1%, 0.3%≤Mn≤2%, Si≤0.3%, Ti≤0.08%, 0.015%≤Nb≤0.1%, Al≤0.1%, S≤0.05%, P≤0.1%, Cu, Ni, Cr, Mo of less than 0.1%, a remainder being iron and unavoidable impurities resulting from elaboration.

8. The longitudinal member according to claim 7 , wherein the rear part has a bending angle greater than 75°.

9. The longitudinal member according to claim 5 , wherein a fraction of martensite in a microstructure of the front part is greater than a fraction of martensite in a microstructure of the rear part.

10. The longitudinal member according to claim 1 , wherein the front part and the rear part are coated with a zinc-based coating or with an aluminum-based coating.

11. The longitudinal member according to claim 1 , wherein the intermediate area extends at an end of an elbow shaped part of the first part such that the front part, outside the elbow shaped part, extends mainly along a first longitudinal axis and the rear part extends mainly along a second longitudinal axis, the first longitudinal axis and the second longitudinal axis being different and substantially parallel to each other.

12. The longitudinal member according to claim 1 , wherein the longitudinal member is configured to extend under a vehicle compartment floor structure of the heavy goods vehicle.

13. A heavy goods vehicle structure comprising:
a heavy goods vehicle body; and
a heavy goods vehicle compartment attached to the heavy goods vehicle body by at least one longitudinal member according to claim 1 ;
the hinge element of the front end of the longitudinal member being attached to a complementary hinge element of the vehicle body to form a hinge connecting the vehicle compartment to the vehicle body in a hinged manner;
the attachment element of the rear end of the longitudinal member being attached to a locking element of the vehicle body to form a locking attachment connecting the vehicle compartment to the vehicle body in a non-permanent manner.

14. The heavy goods vehicle structure according to claim 13 , wherein the hinge is arranged to break in case of an impact applied in a substantially longitudinal direction against the front end of the longitudinal member under an external load greater than 80 kN, while the locking attachment is arranged to resist to the impact when the attachment element is attached to the locking element such that the rear part of the longitudinal member can be crushed to absorb energy in case of said impact.

15. The heavy goods vehicle structure according to claim 13 , wherein the longitudinal member extends under a vehicle compartment floor structure of the heavy goods vehicle structure.

16. The heavy goods vehicle structure according to claim 15 , wherein the vehicle compartment is attached to the vehicle body by at least two longitudinal members extending on either sides of the vehicle compartment floor structure.

17. A method for producing a longitudinal member according to claim 1 , comprising the steps of:
providing a front part blank and a rear part blank,
joining the front part blank to the rear part blank to obtain a member blank; and
hot press forming the member blank into a shape of the longitudinal member, the longitudinal member includes the front part and the rear part, such that the product of the wall thickness of the front part by the yield strength of the material of the front part is greater than the product of the wall thickness of the rear part by the yield strength of the material of the rear part.

18. The method according to claim 17 , wherein the member blank is hot press formed into the shape having a U-shaped cross-section.

19. The method according claim 18 , wherein the member blank is shaped to include an elbow shaped part.

20. The method according to claim 17 , wherein the front part blank is joined to the rear part blank by welding without superposing the front part blank and the rear part blank.

21. The method according to claim 20 , wherein the welding is laser welding.

22. The method according to claim 17 , further comprising:
attaching the hinge element to the front end of the longitudinal member and a step of attaching the attachment element to the rear end of the longitudinal member.

Assignees

• Arcelormittal

Inventors

• Lam Jimmy
• Schneider Nicolas

Classifications

• B23K2101/006

  Vehicles · CPC title

• C21D2211/008

  Martensite · CPC title

• B23K26/21

  by welding · CPC title

• C22C38/44

  with molybdenum or tungsten · CPC title

• C22C38/42

  with copper · CPC title