AU2002321002B2

AU2002321002B2 - Bodywork comprising a front bonnet that is elastically mounted

Info

Publication number: AU2002321002B2
Application number: AU2002321002A
Authority: AU
Inventors: Ingo Renneisen
Original assignee: Adam Opel GmbH
Current assignee: Adam Opel GmbH
Priority date: 2001-07-28
Filing date: 2002-07-25
Publication date: 2008-05-01
Anticipated expiration: 2022-07-25
Also published as: EP1414678A1; EP1414678B1; JP2004535984A; CN1281442C; ES2271307T3; CN1533339A; WO2003011659A1; DE50207949D1; DE10136901A1

Description

00 Bodywork comprising a front bonnet that is elastically mounted The invention concerns a vehicle body with a flexibly mounted bonnet, that Sspans the region between two mudguards of the vehicle body and is joined to C 5 the vehicle body on both sides by a hinge each, so that the bonnet can be lifted about a pivoting axis defined by the hinges, while each hinge has a hinge Sfulcrum at the free end of an arm joined with the vehicle body, the arm 0changing its length in the case of an impact-like load, so that the hinge fulcrum Swill be displaced relative to the vehicle body.

SThe discussion below of the background to the invention is included to explain the context of the invention. This is not to be taken as an admission that any of the material referred to was published, known or part of the common general knowledge in the art as at the priority date established by the present application.

By means of a flexibly mounted bonnet it should be achieved that injuries of a pedestrian hit by the front of a vehicle will remain as light as possible. In the case of such an accident his body rolls onto the bonnet, while the head strikes it and quickly decelerates. The decelerations endurable by the human head within a certain period, within which no heavy injuries will occur, are known to the applicant. To evaluate the progress of deceleration in this respect the HIC value is used, the definition of which can be obtained from the technical literature. Based on legal requirements, vehicle manufacturers endeavour to keep this value for a head impact below 1000.

In the non-supported regions of the bonnet, e.g. in the central region, this is relatively easy to achieve by suitable cushioning below the outer skin of the bonnet. However, the region of the hinges does present a problem, since generally speaking one deals here with a direct non-flexible connection to the vehicle body. To provide an aid in this case, in the case of the vehicle body described in DE 199 22 107 C1 when struck by a head the arm tilts backward against a considerable resistance parallel to the longitudinal axis of the vehicle and by doing so is displaced relative its initial situation parallel to the PASanaDear%2OO20232DOO2 Sped 20 Marc Dp doc la oo 0 longitudinal axis of the vehicle, while the deceleration of the head is N determined by the resistance determined by the construction.

This arrangement is unsatisfactory in the case of an inserted bonnet, merging flush into an adjacent mudguard. When the head strikes in the region of transition from the bonnet to the mudguard, the following situation arises: Salthough the bonnet yields, the head contacts the edge of the mudguard, what may lead to particularly severe injuries, since the force acting on the head is (N not flat, but rather linear. It is known to the applicant, however, to mount the mudguard also flexibly. However, it cannot be assured that both the mudguard Sand the bonnet will yield always at the same extent independently from the exact position of impact, so that no difference will occur between the bonnet and the mudguard.

Similar problems arise also in the case of so called overlapping bonnets.

Although in the region of a possible head impact these do not have a flush transition to the mudguard, as a rule their rear edge merges flush into a section of the vehicle body covering the water channel or forming the Acolumn of the vehicle.

Accordingly, it would be desirable to mount the bonnet in a flexible manner, so that even when being struck by a head in the region of transition to the adjacent section of the vehicle body the expected head injuries, defined by an HIC value, remain as light as possible.

According to the present invention, there is provided a bodywork for a vehicle including a resiliently mounted front bonnet which spans the region between two wings of the bodywork and is connected to the bodywork at each side by a respective hinge so that the front bonnet is adapted to be opened about a pivotal axis defined by the hinges, wherein each hinge includes a pivotal point of the hinge fulcrum which is located at the free end of an extension arm connected to the bodywork and, upon the occurrence of an impulsive load, P 'SandraDeaN2OO8N200232iOO2 Specs 28 March 08 doc 0 downwardly directed displacement with respect to the bodywork, wherein, in Sthe event of the impulsive load, a bonnet mounting rail that is connected to the extension arm at the pivotal point of the hinge fulcrum is shifted inwardly away E from the respective neighbouring wing or the pivotal point of the hinge fulcrum 5 moves forward towards the front of the vehicle so that in each case the displacement of the hinge fulcrum additionally includes a horizontal component away from a section of the bodywork with which the front bonnet merges in _flush manner near the hinge.

The result of this is that the bonnet not only yields, but its edge moves away Sfrom the adjacent section of the vehicle body and by doing so moves the head from the edge of P:%SandraDeaA20v2=321002 Sped 28 March 08.doc the section of the vehicle body, thus preventing a contacting of the section of the vehicle body by the head.

When a component of the displacement in a certain direction is mentioned, it means that the displacement may have additional other components, for example an additional downward directed vertical component, while this preferably absorbs the main portion of the kinetic energy of the head.

Particularly advantageous is when due to the displacement the axis of the hinge fulcrum experiences an additional tilting in a plane perpendicularly to the edge of W:\DELILAABMIm708501-retyped pages.doc the adjacent section of the vehicle body. At the same time the bonnet will also be tilted in this region. By virtue of the incline formed on this occasion the head will be even stronger kept away from the edge of the respective section of the vehicle body, thus further reducing the probability of any injury, In principle the arm itself and its joint with the vehicle body has to be stable in comparison with normal static loads, so that the displacement will occur only above a predetermined load. As it will be explained below, this affects advantageously also the HIC value resulting from being struck by a head.

A vertical and lateral displacement is achieved in a simple constructive manner by pivotably mounting the arm below the hinge fulcrum about an arm fulcrum on the vehicle body and aligning the axis of the arm fulcrum approximately parallel with the edge of the section of the vehicle body. When the load is exceeded, the arm tilts downwards relative its mounting point and away from the adjacent section of the vehicle body, while the hinge fulcrum moves along a circular arc.

Many experiments have shown that a two-stage load of the head keeps the HIC value low, A first stage follows immediately after the head striking the bonnet. The rigidity of he bonnet itself as well as its mounting on the vehicle body causes first a relative great deceleration, the effect of which on the HIC value, however, can be kept low when care is taken that it will be of short duration and a sort of rest period occurs prior to the next force action. In this case this can be achieved by holding the arm on the vehicle body by means of a joint that in the case of a limit load breaks or easily yields. Provided the limit load has not yet been reached, the first stage of the deceleration of the head takes place: the head is temporarily rapidly decelerated and loses a portion of its kinetic energy. When reaching the limit load, the mounting of the arm breaks off, so that the hinge fulcrum carries out only the above described circular movement. The deceleration of the head in this rest period is low. In a second stage contact is made with the parts under the bonnet or parts of the vehicle body. On this occasion, however, the impact takes place commencing with a speed already reduced, so that the expected injuries are in this case not too severe either.

For the purpose of reaching the limit load, the arm and the vehicle body have a cheek each, that abut flat against one another and are passed through by a shear pin. In doing so the shear load limit of the shear pin determines the limit load at the exceeding of which the first phase of the deceleration is terminated.

In the case of an inserted bonnet the section of the vehicle body is formed by adjacent mudguards, extending in the longitudinal direction of the vehicle.

Accordingly, the arm fulcrum has an axis that is parallel with the longitudinal axis of the vehicle. On this occasion the arm fulcrum is preferably provided on a mounting block below a mudguard. The advantage of this is that the mounting of the arm is covered below the mudguard and therefore it will not be an obstacle in the second stage of the deceleration.

In the case of so called overlapping bonnets the critical position is in the region of the rear edge of the bonnet at the transition to the sections of the vehicle body, which form the water channel or parts of the A-column. In this case the axis of the arm fulcrum extends transversely to the longitudinal direction of the vehicle, so that after exceeding the limit load the arm tilts forward, removing the rear edge from the water channel and the A-column.

To further explain the invention two embodiments are explained in the following in detail. They show in: Fig.1 a perspective illustration of a first execution of the hinge on an arm in the initial position, Fig.2 the same hinge after being struck by a head, Fig.3 a front view of the hinge according to Figs.1 and 2 with the mudguard and the bonnet indicated to enable to describe the modus operandi of the hinge, Fig.4 a further execution of the hinge.

,First of all reference is made to Figs.1 and 2. They show a hinge 1 for a bonnet 2 (shown in Fig.3): a bonnet securing rail 3 in the form of a flat bar, that is welded flat to the bonnet 2 or is joined with it by some other means, is connected to an arm 5 via a hinge fulcrum 4, constructed as a link. For this purpose the bonnet securing rail 3 has a bearing cheek 6 that is perpendicular to its main extension.

The arm 5 is a flat lever, bent at an angle at one end, while the bearing cheek 6 of the bonnet securing rail 3 abuts against this bent section 7. The bearing cheek 6 and the section 7 are passed through by a pin 8 forming the hinge fulcrum 4.

The arm 5 is pivotably fastened on a securing rail 9 of the vehicle body, the rail being joined with a strut of the vehicle body. For this purpose the securing rail 9 of the vehicle body also has at its other end a bearing cheek 10, that abuts against a corresponding bearing cheek 11 of the arm. Both these cheeks 10, 11 are also passed through by a pin 12, thus forming the arm fulcrum 13 constructed as a link for the arm 5. Furthermore, both bearing cheeks mentioned 10, 11 are passed through by a shear pin 14 at a distance from the pin 12 of the arm fulcrum 13, said shear pin shearing in the case of a force of a determined magnitude acting on the arm 5 from above thus making a pivoting of the arm 5 about the arm fulcrum 13 possible. The initial situation with an intact shear pin 14 is shown in Fig.l.

This situation with a sheared shear pin 14 is illustrated in Fig.2: the arm 5 has pivoted about the arm fulcrum 13, so that the hinge fulcrum 4 is situated below the initial position and closer to the centre of the vehicle. In addition, the axis of the hinge fulcrum 4 and consequently the bonnet securing rail 3 is tilted.

The result achieved by this can be easily recognised from Fig.3: the securing rail 9 of the vehicle body can be recognised from the front and the bearing cheek joined with it, on which the arm 5 is pivotably mounted. The bearing cheeks are situated below a mudguard 15. The arm 5 extends towards the interior, to the left of the drawing, its end, bent at an angle, standing approximately vertically.

The bonnet 2 is fastened on the forward extending bonnet securing rail 3, the bonnet merging approximately flush into the mudguard The impacting head, illustrated in this case as a ball 17, strikes the transition region of the mudguard 15 and the bonnet 2, while the centre of gravity is above the bonnet 2. The bonnet will be pushed downward by the inertia of the impact and the arm 5 will be under load. At a certain force the shear pin 14 will shear, so that the arm 5 will yield. This leads to a pivoting movement about the arm fulcrum 13, due to which the bonnet securing rail 3 will be displaced inwards, away from the mudguard 15, and will be inclined. At the same time the head (ball 17) will be carried along and removed off the mudguard 15, as this is indicated by the ball 17 shown in dotted lines.

Fig.4 illustrates a further execution of the invention. A hinge 1 on an arm 5 is illustrated, intended for an overlapping bonnet. In the case of such an execution the bonnet in the rear region should be moved forward from the A-column 18 under the impact of a head. In contrast to the execution described above, for this purpose the axis of the arm fulcrum 13 is aligned in the transverse direction of the vehicle. The result of this is that after the shearing of the shear pin 14 the hinge fulcrum 4 moves on a circular arc according to arrow 19 forward to the front of the vehicle and downward and at the same time the head, illustrated in this case also by a ball 17, is moved away from the A-column 18. Otherwise the execution of Fig.4 corresponds to those illustrated in Figs.1 to 3, so that the same reference numerals are used.

List of reference numerals 1 Hinge 2 Bonnet 3 Bonnet securing rail 4 Hinge fulcrum Arm 6 Bearing cheek 7 Section 8 Pin 9 Securing rail of the vehicle body Bearing cheek 11 Bearing cheek 12 Pin 13 Arm fulcrum 14 Shear pin Mudguard 17 Ball 18 A-column 19 Arrow

Claims

1. A bodywork for a vehicle including a resiliently mounted front bonnet which spans the region between two wings of the bodywork and is connected r' 5 to the bodywork at each side by a respective hinge so that the front bonnet is adapted to be opened about a pivotal axis defined by the hinges, wherein each Shinge includes a pivotal point of the hinge fulcrum which is located at the free end of an extension arm connected to the bodywork and, upon the occurrence Cof an impulsive load, changes its position in such a manner that it rotates about a pivotal point of the extension arm so that the pivotal point of the hinge Sfulcrum experiences a downwardly directed displacement with respect to the bodywork, wherein, in the event of the impulsive load, a bonnet mounting rail that is connected to the extension arm at the pivotal point of the hinge fulcrum is shifted inwardly away from the respective neighbouring wing or the pivotal point of the hinge fulcrum moves forward towards the front of the vehicle so that in each case the displacement of the hinge fulcrum additionally includes a horizontal component away from a section of the bodywork with which the front bonnet merges in flush manner near the hinge.

2. A bodywork in accordance with claim 1, wherein the displacement has a downwardly directed vertical component.

3. A bodywork in accordance with claim 1 or 2, wherein the axis of the pivotal point of the hinge fulcrum is tilted in a plane perpendicular to the edge of the neighbouring wing of the bodywork due to the displacement.

4. A bodywork in accordance with any of the claims 1 to 3, wherein the displacement occurs only above a predetermined load.

5. A bodywork in accordance with any of the claims 1 to 4, wherein the extension arm is rotatably mounted on the bodywork at a pivotal point of the extension arm below the pivotal point of the hinge fulcrum and the axis of the pivotal point of the extension arm is aligned approximately parallel to the edge of the section of the bodywork. PASandrameaf2O8O2M232102 SpWc 26 Marcl 08 dc 1 00 N

6. A bodywork in accordance with any of the preceding claims, wherein the extension arm is held on the bodywork by means of a connection which breaks E or gives way under the predetermined load. C

7. A bodywork in accordance with claim 6, wherein the extension arm and Sthe bodywork each includes a cheek which lie flatly upon one another and are penetrated by a shear pin. (Ni

8. A bodywork in accordance with any of the preceding claims, wherein the N said section of the bodywork is formed by the wing and the displacement has a component transverse to the longitudinal direction of the vehicle, wherein the axis of rotation of the pivotal point of the extension arm runs essentially parallel to the wing, and the pivotal point of the extension arm is arranged on a bearing block underneath the wing.

9. A bodywork in accordance with any of the claims 1 to 7, wherein the rear edge of the front bonnet merges in flush manner into sections of the bodywork which form the water tank or parts of the A-pillar and in that the axis of the pivotal point of the extension arm extends transversely relative to the longitudinal direction of the vehicle so that the extension arm tilts forwardly after the critical load has been exceeded. A bodywork according to any one of the embodiments substantially as herein described and illustrated. P:%Sandraea8200MU321002 Sped 26 MarCh O8.(c