SE1550323A1

SE1550323A1 - Progressive crash box member and arrangement

Info

Publication number: SE1550323A1
Application number: SE1550323A
Authority: SE
Inventors: Stoddart Tom; GRAMMAHAGE Henrik; Karlsson Peter; Svensson Martin
Original assignee: China-Euro Vehicle Tech Ab
Priority date: 2015-03-17
Filing date: 2015-03-17
Publication date: 2016-09-18
Also published as: WO2016148635A1

Abstract

The invention relates to a progressive crash box member comprising multiple channels, the channels being restricted by an external and internal structure, the structures being orientated essentially parallel to the direction of an impact compression force, wherein at least one internal structure inside the member comprises at least one recess.(Fig. 7)

Description

PROGRESSIVE CRASH BOX IVIEIVIBER AND ARRANGEIVIENT Technical field

[0001] The present invention relates to a crash box member, an arrangementcomprising said crash box member, a vehicle comprising the crash box, and a vehicle comprising the arrangement.

Background art

[0002] Vehicles transporting persons comprise structures which absorb externalforces during impact. Specifically the front portion of a vehicle needs structureswhich are able to absorb significant compression forces which are e.g. generatedduring a frontal crash. Although the structures must be designed to absorbsignificant forces e.g. during a frontal crash it is desired that said structures arecapable of also handling minor (compression) forces without damaging expensivestructural members of the vehicle. Also, such structures shall also be capable of coping with non-impact stresses during normal driving conditions.

[0003] US 6502874 discloses a coupling structure of a shock transmittingmember, a shock absorbing member and a bumper. US 6502874 does not teachthe presence of recesses in the partitions in the crash box.

[0004] The present invention provides a crash box member and an arrangementwith a design effective to cope with significant compression loads while alsomanaging minor loads without damaging expensive structural parts of a vehicleand also maintaining these characteristics during the lifetime of the vehicle.

Brief description of drawinds

[0005] The invention is now described, by way of example, with reference to theaccompanying drawings, in which:

[0006] Fig. 1 and 2 depict a progressive crash box member, a beam and a platewith different geometries.

[0007] Fig. 3 shows a progressive crash box member, a beam and a plate. 200163SE

[0008] Fig. 4 shows cross sectional views of a rectangular progressive crashbox comprising six channels and a plate.

[0009] Fig. 5 depicts a cross sectional view of a rectangular progressive crashbox and a plate, with six channels and a bolt.

[0010] Fig. 7 shows a cross sectional view of a rectangular progressive crashbox and a plate comprising a flange, with six channels and a bolt.

[0011] Fig. 8 shows a cross sectional view of a rectangular progressive crashbox with internal structures of different thicknesses.

[0012] Fig. 9 shows part of an internal structure with a recess.[0013] Fig. 10 shows the plate with two flanges. lnvenüon

[0014] The present invention relates to a compressive crash box member 1comprising multiple channels 32, where the channels are restricted by an external31 and internal 33 structure, the structures being orientated essentially parallel tothe direction of an impact compression force, wherein at least one internalstructure inside the member comprises at least one recess 51.

[0015] A further aspect of the invention relates to a crash box member 1obtainable by extrusion comprising multiple channels 32 being restricted by anexternal 31 and internal 33 structure, whereby the member is positioned such thatthe direction of an impact compression force is essentially parallel to the directionof extrusion, the member comprising multiple channels being restricted by externaland internal structures, wherein at least one structure inside the membercomprises at least one recess 51.

[0016] lt is preferred that the internal structures 33 of the crash box member 1comprises a multitude of recesses 51 in the internal structure which suitably arepositioned at a location of the member exhibiting the impact force early in a timeframe from impact to completed deformation of the member. The recesses 51 in 200163SE the internal structure 33 are preferably located in a location as far as possible forthe chassis as possible such as between the middle of the member and the frontend of the member. By front end is meant the region of the member fixed to astructure obtaining the initial impact.

[0017] The term “compression forces” should be understood as forces that aregenerated as a result of a sudden impact and do not include forces induced undernormal driving conditions. Compression forces may be generated during a collisionof a vehicle with an object, such as another moving vehicle or stationary objects.

[0018] Although the crash box member 1 can be formed by a variety ofprocesses the crash box is preferably formed by extruding a suitable metal. Suchmetal can be selected form any metal providing sufficient rigidity and loadabsorption. The crash box member suitably comprises of aluminium or an alloy comprising aluminium.

[0019] According to an embodiment the member 1 comprises external and internal structures which have non-uniform thicknesses.

[0020] According to yet another embodiment the member 1 has preferably anessentially rectangular cross-section. According to this embodiment the membercomprises an external structure which comprises upper 311 and lower 312external sub structures and side sub structures 331, 332. These four external sub structures may have different thicknesses.

[0021] According to yet another embodiment the crash box member 1comprises six channels which are restricted by internal 33 and external 31structures.

[0022] According to a further embodiment the crash box member 1 haspreferably an essentially rectangular cross-section comprising an internal structure33 which comprises sub structures 333 being essentially parallel to the externalstructure. These internal sub structures 333 may all have different thicknesses.The thickness distribution of an internal sub structure 333 may be evenly distributed, yet, the thickness of an internal sub structure 333 may also exhibit a 200163SE4 thickness distribution. According to one aspect, the thickness of an internal substructure 333 is evenly distributed.

[0023] According to a further embodiment the crash box member 1 does notcomprise structures which are essentially perpendicular to both the internal and external structures.

[0024] A further embodiment of the invention relates to a crash box member 1comprising multiple channels 32, the channels being restricted by an external 31and internal 33 structure, the structures being orientated essentially parallel to thedirection of an impact compression force, the member exhibiting an essentiallyrectangular cross-section, the external structure comprising upper and lowerexternal sub structures 311, 312 and side sub structures 331, 332, the internalstructure 33 comprising sub structures 333 being essentially perpendicular andparallel to the external structure, wherein the internal structure 33 inside themember comprises at least one recess 51. Suitably, the crash box member 1comprises six channels 32 said channels being restricted by an internal structure33 comprising seven internal sub structures 333 and an external structure 31comprising upper and lower external sub structures 311, 312 and side substructures 331, 332, whereby the upper and lower substructures 311, 312 and sidesub structures 331, 332 are essentially parallel. The internal sub structures 333may exhibit different thicknesses such that each internal sub structure may have adistinct thickness. According to an embodiment the thickness of the external andinternal structures may have different ranges depending on multiple factors. Forexample, the weight of the vehicle and the coefficient of elasticity for the materialof the crash box influences the thickness. However, in one embodiment is thethickness range from about 1,9 mm up to about 2,3 mm.

[0025] According to yet a further embedment the crash box member comprisesa bolt 40. The bolt is preferably secured with a nut 41. The bolt 40 is typicallylocated in the front region of the crash member. lf the crash member 1 exhibit anessentially rectangular cross section the bolt passes through the upper and lowerexternal sub structures 311, 312. According to a further embodiment the bolt 200163SE passes through an internal sub structure in an area of a recess 51. The bolt maypass through several internal sub structures which is partly dependent on the number of channels.

[0026] According to yet another embodiment the progressive crash box membermay be attached to a plate 7. The plate 7, which is located at the opposite sidewith respect to a structural member such as a chassis, suitably comprises at leasta flange 61 which supports the crash box member. The flange and the crash boxmember is are preferably welded together.

[0027] According to another embodiment is the flange 61 is an anti-rippingdevice 61 adapted to limit bending forces (moment) during offset crashes whereinimpact forces only affects a portion of the front beam 2. The flange 61 may be an extruded flange 61 with a heat effected weld zone.

[0028] A further aspect of the invention relates to an arrangement comprising a(longitudinal) front beam 2 and a structural member, wherein the crash boxmember 1 as elaborated herein is positioned between said longitudinal front beamand the structural member. Suitable, the arrangement comprises a plate 7between the front beam 2 and the crash box 1.

[0029] According to one embodiment of an arrangement wherein the crash boxmember 1 further comprises a flange 61 arranged adjacent to an external structure31, preferably abutting a side sub structure 331, 332 is the flange 61 adapted to bean anti-ripping device 61.

[0030] The flange 61 servers the purpose of absorbing moment forces during asmall offset collision, or any offset collision, through enhancing the interfacebetween the plate 7 and the crash box member 1. ln one embodiment is the flange61 welded to both the crash box member 1 and the plate 7, in anotherembodiment is the flange 61 part of the plate 7 and welded to the crash box member 1.

[0031] Yet a further aspect of the invention relates to a vehicle comprising acrash box member as elaborated herein. 200163SE

[0032] Yet a further aspect of the invention relates to a vehicle comprising an arrangement as defined above.

Claims

200163SE CLAIIVIS

1. A progressive crash box member (1) comprising multiple channels (32),the channels being restricted by an external (31) and internal (33) structure, thestructures being orientated essentially parallel to the direction of an impactcompression force, wherein at least one internal structure inside the membercomprises at least one recess (51 ).

2. A crash box member (1) obtainable by extrusion comprising multiplechannels (32) being restricted by an external (32) and internal structure (33),whereby the member is positioned such that the direction of an impactcompression force is essentially parallel to the direction of extrusion, the membercomprising multiple channels (32) being restricted by external (32) and internal(33) structures, wherein at least one structure inside the member comprises at least one recess (51).

3. The crash box member (1) according to claims 1 and 2, wherein the internal structure (33) comprise multiple recesses (51).

4. The crash box member (1) according to any one of the preceding claims,wherein the recess(es) (51) is/are positioned at a location exhibiting the impactcompression force early in a time frame from impact to completed deformation of member.

5. The crash box member (1) according to any one of the preceding claims,wherein the recess(es) (51) is/are positioned in a location between the middle andthe front end of the member (in the direction of initial impact).

6. The crash box member (1) according to any one of the preceding claims,wherein the internal structure inside the crash box has non-uniform thicknesses.

7. The crash box member (1) according to any one of the preceding claims,wherein the external structure (31) of the member has non-uniform thicknesses. 200163SE

8. The crash box member (1) according to any one of the preceding claims,comprising a bolt (40) through the crash box and a beam.

9. The crash box member (1) according to claim 8, wherein the bolt ispositioned such that the bolt passes through at least one recess of the internalstructure.

10. The crash box member (1) according to any one of the preceding claims, wherein the member has an essential rectangular cross-section.

11. The crash box member (1) according to any one of the preceding claims, wherein the member comprises aluminium.

12. The crash box member (1) according to any one of the preceding claims,wherein the member comprises at least five channels, preferably six channels.

13. An arrangement comprising a front beam and a structural member,wherein the crash box member (1) as defined by claim 1 to 12 is positionedbetween said longitudinal front bumper and the structural member.

14. The arrangement according to claim 13, wherein the plate (7) furthercomprises a flange (61) arranged in the arrangement adjacent to an externalstructure (31) of the crash box member (1 ), preferably abutting a side substructure (331, 332).

15. A vehicle comprising the arrangement as defined by any one of claims 1to 14.