Front structure of a vehicle

Patent metadata

Field	Value
Publication number	US-9428129-B2
Application number	US-201414566765-A
Country	US
Kind code	B2
Filing date	Dec 11, 2014
Priority date	Dec 18, 2013
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

A front structure of a vehicle comprises a pair of side members arranged in a longitudinal direction of the vehicle, a pair of crash boxes arranged at front ends of the side members, and a body back-up structure located at a rear end of the front portion. The front structure is adapted to give an impact response curve with deceleration versus time, when subjected to a full frontal barrier impact at 35 mph according to USNCAP. The impact response curve comprises in sequence:
a first phase during which deceleration increases, a second phase forming a first peak level of the deceleration, a third phase during which the deceleration is less than during the second phase, and a fourth phase forming a second peak level of the deceleration, during which fourth phase the deceleration is greater than during the third phase.

First claim

What is claimed is:

1. A front structure of a vehicle, the front structure comprising:
a front exterior and/or a bumper;
a pair of side members arranged in a longitudinal direction of the vehicle at a respective left-side portion and right side portion of a front portion of the vehicle;
a pair of crash boxes having a lower axial strength than the side members, each crash box being arranged at a front end of a respective side member;
at least one stiff component that is more stiff than the front exterior and/or the bumper; and
a body back-up structure located at a rear end of the front portion;
wherein the front structure is adapted to give an impact response curve with deceleration versus time, when subjected to a full frontal barrier impact at 35 mph, the impact response curve having in sequence
a first phase during which deceleration increases,
a second phase forming a first peak level of the deceleration,
a third phase during which the deceleration is less than during the second phase, and
a fourth phase forming a second peak level of the deceleration, during which fourth phase the deceleration is greater than during the third phase.

2. The front structure according to claim 1 wherein the front exterior and/or bumper, the side members and the crash boxes are arranged, dimensioned and/or shaped in relation to each other, such that in case of the full frontal barrier impact at 35 mph,
during the first phase, the front exterior is compressible and/or the bumper is deformable,
during the second phase, the crash boxes are compressible, and
during the third phase, the side members are bendable,
whereby a deceleration achievable by the front exterior being compressed and/or the bumper deforming is less than a deceleration achievable by the crash boxes being compressed, and a deceleration achievable by the side members bending is less than the deceleration achievable by the crash boxes being compressed.

3. The front structure according to claim 1 wherein the crash boxes are arranged, dimensioned and/or shaped such that the crash boxes are compressible substantially after the front exterior has been compressed and/or the bumper has deformed.

4. The front structure according to claim 1 wherein the side members are arranged, dimensioned and/or shaped such that the side members are bendable substantially after the crash boxes have been compressed.

5. The front structure according to claim 2 wherein the side members are arranged to at least partly bend laterally in relation to a longitudinal center-line of the vehicle during the third phase.

6. The front structure according to claim 1 wherein each side member comprises a support at a rear end of the side member.

7. The front structure according to claim 6 wherein each support is a triangular or Y-shaped support.

8. The front structure according to claim 1 further comprising a subframe located vertically below the side members, the subframe being arranged, dimensioned and/or shaped to bend simultaneously with the side members.

9. The front structure according to claim 8 further comprising a pair of lower load-path crash boxes arranged at a front end of the subframe, the lower load-path crash boxes being adapted to be compressed substantially simultaneously as the crash boxes located at the front ends of the side members.

10. The front structure according to claim 8 wherein the subframe is arranged to be detachable from one or both of the side members during bending of the side members or when the side members have bent.

11. The front structure according to claim 10 wherein the subframe is arranged to be detachable from one or both of the side members by means of a pyrotechnic detachment device.

12. The front structure according to claim 1 wherein the at least one stiff component comprises an engine, and wherein the front structure further comprises an engine mount adapted to fasten the engine to one of the side members, the engine mount being adapted to rupture when the side member bends.

13. The front structure according to claim 1 further comprising a spring tower attached to one of the side members by an attachment means, the spring tower being adapted to support a suspension of the vehicle, and the attachment means being arranged such that the spring tower is adapted to detach progressively from the one side member during bending of the one side member.

14. The front structure according to claim 8 wherein the at least one stiff component comprises an engine, and wherein the front structure further comprises a lower tie bar adapted to fasten the engine to the subframe, the lower tie bar being adapted to rupture when the side members and/or the subframe bend/s.

15. The front structure according to claim 1 wherein during the fourth phase the at least one stiff component is adapted to stack up against the body back-up structure, a deceleration achievable by the at least one stiff component stacking up against the body back-up structure being greater than a deceleration achievable by the side members bending.

16. The front structure according to claim 1 wherein the front structure is adapted to achieve at least 10% of the velocity change during the first and second phases, when subjected to the full frontal barrier impact at 35 mph.

17. The front structure according to claim 1 wherein the front structure is adapted to achieve at least 15% of the velocity change during the first and second phases, when subjected to the full frontal barrier impact at 35 mph.

18. The front structure according to claim 1 wherein the deceleration during the third phase is less than 80% of the deceleration during the second phase.

19. The front structure according to claim 18 wherein the deceleration during the third phase is less than 70% of the deceleration during the second phase.

20. A front structure of a vehicle, the front structure comprising:
a bumper;
first and second side members arranged in a longitudinal direction of the vehicle at a left-side portion and a right-side portion, respectively, of a front portion of the vehicle;
first and second crash boxes located behind the bumper, the first crash box being arranged at a front end of the first side member, and the second crash box being arranged at a front end of the second side member, the crash boxes having a lower axial strength than the side members; and
a body back-up structure located at a rear end of the front portion and connected to the side members;
wherein the front structure is adapted to give an impact response curve with deceleration versus time, when subjected to a full frontal barrier impact at 35 mph, the impact response curve having in sequence
a first phase during which deceleration increases,
a second phase forming a first peak level of the deceleration,
a third phase during which the deceleration is less than during the second phase, and
a fourth phase forming a second peak level of the deceleration, during which fourth phase the deceleration is greater than during the third phase.

Assignees

• Volvo Car Corp

Inventors

• Crona Ragnar
• Mcinally Graeme
• Ljungquist Henrik
• Stoddart Tom
• Nejabat Babak
• Wagstrom Linus
• Van Der Putten Zef

Classifications

• B62D25/082

  Engine compartments · CPC title

• B62D21/152 Primary

  Front or rear frames · CPC title

• B60R19/34 Primary

  destroyed upon impact, e.g. one-shot type · CPC title

• B60G2206/016

  allowing controlled deformation during collision · CPC title