AU2002320905B2

AU2002320905B2 - Vehicle body comprising an elastically mounted bonnet

Info

Publication number: AU2002320905B2
Application number: AU2002320905A
Authority: AU
Inventors: Werner Bittmann; Alois Schmitz
Original assignee: Adam Opel GmbH
Current assignee: Adam Opel GmbH
Priority date: 2001-07-05
Filing date: 2002-07-03
Publication date: 2008-05-08
Anticipated expiration: 2022-07-03
Also published as: ES2272752T3; DE50212340D1; EP1743812B1; CN1315674C; EP1743812A2; JP2004532770A; CN1520362A; EP1743812A3; DE50208347D1; EP1406794A1; EP1406794B1; WO2003004319A1; DE10132656A1; ES2306333T3

Description

00 SVehicle body with a flexibly mounted bonnet The invention concerns a vehicle body including a flexibly mounted bonnet, a 00 hinge each between the vehicle body and a lateral wall of the bonnet, so that it could be lifted about a pivoting axis defined by the hinges and at least one v component that can yield under a load on each lateral edge to mount the bonnet on the vehicle body.

(Ni A reference herein to a patent document or other matter which is given as prior Sart is not to be taken as an admission that that document or matter was, in Australia, known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

One type of vehicle body known to the Applicant is described in DE 27 11 339 Al. The mounting of the bonnet suggested therein is based on the following consideration: accidents happen time after time, in which a vehicle frontally hits a pedestrian crossing the street. As a result of this the body and the head of the pedestrian strike the bonnet, causing heavy injuries. Therefore the vehicle manufacturers attempt so to construct the vehicle body and particularly the front with the bonnet, that while an injury is not ruled out, the severity of the injury will be reduced. In particular, to prevent serious head injuries, the bonnet is flexibly mounted. The time delays occurring in the case of being struck by a head should have a progress in time having an HIC (Head Injury Criterion) value of 1000. The HIC value is an indicator to describe the still endurable load on the human head. The exact definition of this value can be obtained from the technical literature.

The published patent application already mentioned above suggests to mount the bonnet on the vehicle body by means of flexible, energy dissipating components, that are partly constructed in the hinge. As to how such an element actually could be constructed does not, however, become apparent from the publication. There is also the additional problem to provide the element with sufficient basic rigidity, so that it would not yield under BEHI708S4Q_SPEl-_BEHApr8.doc 0 conventional static loads, only under an impact-like load such as the one Soccurring when struck by a body or a head.

According to the present invention, there is provided a vehicle body having a 00 flexibly mounted bonnet, having a hinge between the vehicle body and each side of the bonnet to allow the bonnet to be hinged open about a pivotal axis defined by the hinges, and having at each side edge at least one constructional unit that yields under load for mounting the bonnet on the Cvehicle body, wherein the constructional unit is designed as a stable but plastically deforming crash box, which yields above a specific load during an 0 impact-like force, wherein the crash box includes a tube, the longitudinal axis of the tube being disposed substantially parallel to the direction of the impactlike force and which has tube edges that are connected to one another by lateral surfaces.

Advantageously, the present invention can provide a stable yet plastically deforming crashbox that yields during an impact-like load that is in excess of a specified load.

In a preferred embodiment, the crashbox includes two parallel support walls that are parallel to the direction of impact. In the case of a static load the support walls can absorb the load without buckling. When an impact-like force acts, the support walls can irreversibly bend and by doing so dissipate energy.

The thickness and the expansion of the support walls determine their static rigidity and the magnitude of the absorbed energy.

In a particularly preferred embodiment, the tube of the crashbox has a square cross-section, the longitudinal axis of which is arranged substantially parallel to the direction of the force. Such crashboxes with clearly greater dimensions are known to the Applicant as mountings of vehicle bumper bars or as the longitudinal beam of the vehicle. As a rule, one deals here with tubes having an enclosed square cross-section, that are so arranged that in the case of an impact they are loaded in the longitudinal direction. When in this case a specified load is exceeded, the edges of the tubes can buckle, varying inward 8EH1708549.SPECI_BEHAp08.doc

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3 oo and outward, while the lateral surfaces joining the edges will lie in the folds.

C)Because these processes are irreversible, the energy inherent to the impact is 4 dissipated. Since the edges impart a certain rigidity to the tube, it can be fully statically stressed without backing. Thus the tube can be used as a beam or a 00 joining strut within a structure. By virtue of the tubular construction further parameters are revealed, so that the basic rigidity and the energy absorption during a compact-like load can be even better harmonised.

CParticularly critical is the mounting of the bonnet in the vicinity of the hinges, since the hinges are directly joined to the vehicle body. The already Smentioned published patent application known to the Applicant suggests that the hinge has at least one torsion spring-loaded cranked level as flexible component. The realisation of this is quite elaborate. Therefore, in a preferred embodiment the crashbox is an integral component of the hinge and for this purpose it is arranged between an upper strut and a lower strut of the hinge, the struts being joined with one another by means of at least one folding lever.

This arrangement has the advantage that the conventional method of construction of the hinge need not be modified. On the contrary, a crashbox according to the invention needs only to be integrated in the intermediate space between the two struts.

It could, however, be also conceivable to arrange the crashbox between the lower strut and the vehicle body. The construction expense is small also in this case. The hinge, as such, may remain unchanged. Only its mounting on the vehicle body has to be positioned deeper to provide room for the crashbox.

In the case of hinges that have a shorter and a longer folding lever, so that the bonnet during lifting could be opened about a pivoting axis that at the same time is displaced, the crashbox can be arranged on the upper strut in the vicinity of the closely adjacent joints of the folding lever, so that the impact forces introduced into the hinge can be absorbed in a more optimal manner.

The Applicant is aware of arrangements where single-arm hinges have a folding lever extending in an arc, while one end of the folding lever is BEH708549._SPECI_BEH_Apr08.doc 4 00 0 connected with an upper strut joined with the bonnet, while the front arc portion Sjoined with that end extends approximately perpendicularly to the bonnet and the other end of the folding lever is rotatably mounted on the vehicle body. For these type of hinges, the crashbox can be constructed in the front arc portion.

00 The advantage of this embodiment is that no additional construction space is u required, since only a section of the folding lever constructed previously rigidly now has an additional function. Since the front arc portion of the folding lever Nq extends in the direction of the impact, it is only during an impact that it is compressed, which in the case of the crashbox can be easily achieved.

Thus, just like in the embodiment already described, the crashbox can have at least two support walls that are arranged substantially parallel to the direction of the force and thus substantially parallel to the front arc portion of the folding lever. By virtue of the number and arrangement of the support walls, the degree of dissipation of the energy can be constructively set and matched to suit the type of the vehicle.

Another possibility is to construct the crashbox by weakening the folding lever in the front arc portion. Whereas in the above described embodiment the support walls are joined with one another and the folding lever by means of transversely arranged plates, resulting in a certain expense, the weakenings can be carried out on the folding lever itself, which is relatively simple to achieve during the manufacture. In the case too there is a wider extent of constructive freedom to set the degree of energy absorption.

In a preferred embodiment, beads can be particularly simply realised in the front arc portion, the beads extending substantially transversely to the arc portion. In preferred embodiments having the beads arranged on alternating sides, an accordion effect occurs when the folding lever is compressed, resulting in a relatively even progress of the force.

The invention is explained in details below based on four embodiments. The show in: BEH/0854QSPECIDEH Apr8,doc 00 Fig.1 a first embodiment, wherein a crashbox is arranged in the hinge, SFig.2 a second embodiment, wherein a crashbox is situated below a hinge, Fig.3 a third embodiment, wherein a crashbox is a component of a folding lever of the hinge, 00 Fig.4 a third embodiment, wherein the crashbox is achieved by weakening the folding lever.

Both figures show a hinge 1 for a bonnet that is not illustrated here in detail.

SThe hinge 1 comprises an upper strut 2, that is welded or bolted to the bonnet, and a lower strut 3 that is bolted to the vehicle body. Between the two struts 2, N3 two folding levers 4, 5 extend, each of them pivotably mounted in joints 6, 6', 7, 7' on the struts 2, 3. So that during opening the bonnet would move upward and forward to avoid a collision of its rear edge with a frame surrounding the bonnet, one folding lever 4 is longer than the folding lever 5 and the joints 6, 6' on the upper strut 2 are closer than the joints 7, 7' on the lower strut 3. In this manner the pivoting axis of the bonnet moves forward when being opened.

According to the embodiment shown in Fig.1 there is a crashbox 8 between the two struts 2, 3, in the region of the closely adjacent joints 6, 6' of the upper strut 2. The crashbox comprises an upper plate 9 and a lower plate 10, that abut flat against the struts 2, 3. Between the plates 9, 10 two support walls 11, 12 extend that are parallel to and at a distance from one another and are aligned perpendicularly to the struts 2, 3. The upper plate 9 forms a stop for the upper strut 2 thus defining the closed position of the hinge 1.

According to the execution shown in Fig.2 the crashbox 8 is situated between the lower strut 3 and the vehicle body, for which purpose the vehicle body has a step, not illustrated here. The closed position of the bonnet and consequently of the hinge 1 is ensured by stops. One stop 13 is schematically illustrated in Fig.2.

The execution of the crashbox 8 is the same in both cases. In both cases the two support walls 11, 12 may be complemented by further support walls. They BH708549SPECI_BEH Apr08,doc

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6 00 0 may be parallel to those shown, but also perpendicularly to them and form N together a tube with a rectangular cross-section.

When a body strikes the bonnet, an impact-like force is exerted on the hinge 1 00 in accordance with arrow 14. The forces are transmitted to the crashbox 8 via the upper strut 2, due to which the support walls 11, 12 will irreversibly buckle Soutward or inward and by doing so absorb the energy of deformation. The thickness and the lateral expansion of the support walls 11, 12 determine the t' delay occurring on this occasion, which delay can be made to concur with the HIC value aimed for.

In the execution according to Fig.2 when struck by a head in the direction of arrow 14 first the stop 13 will yield. Both struts 2, 3 will lie against one another due to the sagging of the folding levers 4, 5, so that the compressed hinge 1 is pushed against the crashbox 8 that, as described above, will yield after a specified delay.

Figs.3 and 4 illustrate an execution of the invention for a hinge 1 with a folding lever 15. This has typically an arc shape, so that the hinge joint 16 can be arranged below part of the body in an extension of the bonnet. When the bonnet is lifted, the folding lever 15 with its curved shape engages around the edge of the section of the vehicle body that faces the bonnet.

Since in the closed state of the bonnet the front arc portion 17 extends approximately vertically, i.e. in the direction of the impact of the head, in a suitable manner it can accommodate an energy-absorbing device or a crashbox 8. A solution, wherein the crashbox 8 has support walls 11, is illustrated in Fig.3. For this purpose the folding lever 15 is divided in the front arc portion 17 and the crashbox 8 with a plurality of parallel extending support walls 11 extending between two plates 9, 10 is inserted, with the external sides of which both ends of the division are joined with the crashbox 8.

A further execution of a crashbox is shown in Fig.4. The crashbox 8 comprises a sole support wall 11 that is a section of the folding lever 15. To obtain the BEH/O854Os SPECI_EHAPrO8.dOC 00 00 k oo 7 desired flexibility, the support wall 11, i.e. a corresponding section in the front arc portion 17 of the folding lever 15, is provided with beads 18 extending transversely on both sides, that will affect that in the case of an impact load the folding lever 15 will be compressed like an accordion.

List of reference numerals 1 2 3 4 6,6' 7,7' 8 9 11 12 13 14 16 17 18 Hinge Upper strut Lower strut Folding lever Folding lever Joint Joint Crashbox Plate Plate Support wall Support wall Stop Arrow Folding lever Hinge joint Front arc portion Bead The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the above description.

Throughout the description of this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives or components or integers.

BEH7O8549..SPECI_BEH_AprO8.doc

Claims

23. APR. 2008 15:04 PHILLIPS ORMONDE FITZPATRICK NO. 6149- P. 0 8 o Patent claims C-I The claims defining the present invention are as follows: I A vehicle body having a flexibly mounted bonnet, having a hinge between the vehicle body and each side of the bonnet to allow the bonnet to be hinged open about a pivotal axis defined by the hinges, in and having at each side edge at least one constructional unit that yields under load for mounting the bonnet on the vehicle body. C wherein the constructional unit is designed as a stable but plastically deforming crash box, which yields above a specific load during an Simpact-like force, wherein the crash box includes a tube, the c N I longitudinal axis of the tube being disposed substantially parallel to the direction of the impact-like force and which has tube edges that are connected to one another by lateral surfaces. 2 A vehicle body according to claim 1, wherein the tube of the crashbox is arranged, in cross-section, as a square tube. 3 A vehicle body according to any one of the preceding claims, wherein the crashbox Is an integral component of the hinge and for this purpose is disposed between an upper strut and a lower strut of the hinge, which are connected to one another by at least one folding lever. 4 A vehicle body according to claim I or 2, wherein the crashbox is disposed between a lower strut of the hinge and the vehicle body. A vehicle body according to claim 3, wherein a shorter and a longer folding lever are disposed between the upper and the lower strut, wherein the shorter and longer folding levers are fastened relatively closely adjacent to one another by joints to the upper strut, and wherein the crashbox is disposed near the closely adjacent joints. aeW7BS_P5C1LB9tMOMB4 COMS ID No: ARCS-187960 Received by IP Australia: Time 15:05 Date 2008-04-23 23-APR.2008 15:04 PHILLIPS ORMONDE FITZPATRICK NO. 6149-P. 6 00 c g 6 A vehicle body according to claim 1 or 2, wherein the hinge includes a further folding lever extending in an arc, wherein the one end of the further lever is connected in a fixed manner to an upper strut, wherein a front arc portion adjoining said one end of the further folding lever extends approximately perpendicularly to the bonnet and wherein the other end- of the further folding lever is mounted rotatably on the body and the crashbox is formed in the front arc portion. 7 A vehicle body having a flexibly mounted bonnet according to any one of the embodiments substantially as herein described. nBEwueGssSECLBEOiaOSSA COMS ID No: ARCS-187960 Received by IP Australia: Time 15:05 Date 2008-04-23