DE102006029351B3 - Fastening system and fastening method for fastening a bodywork element to a chassis - Google Patents

Abstract

The system has a body surface with a slotted hole (26) and a body profile thickness. A bracket (2) between an upper and a middle side part (12, 14) has an opening (22) for a body equipment mounting surface. Between the side parts, chassis opening (40) is provided. The middle side part has a center passage being smaller than a diameter of a screw for the prefixing and a final adjustment screw (4, 6). The slotted hole is longer than an external distance between the prefixing screw (4) and the final adjustment screw (6) so that they rise in a linear extension of the body. An independent claim is included for a method for attaching a body element to a chassis of a motor vehicle.

Description

The The invention relates to a fastening system and a fastening method for attaching a bodywork element to a chassis (body shell) a motor vehicle by means of a screw. The bodywork element has a body surface with a slot and a body profile strength; the chassis has a chassis surface a chassis profile thickness. Preferably, such a fastening system for attachment a fender on the frame of a motor vehicle, in particular a car used.

From the DE 102 31 099 A1 is a fastening system for fastening a body member having a body surface with a slot and a body profile thickness, on a chassis of a motor vehicle having a chassis surface with a chassis profile thickness, known by means of a screw. Through the use of a collar bush, the waistband height is greater than the body profile thickness, the body element can shift relative to the chassis with temperature fluctuations. A similar fastening system is also from the DE 102 13 168 A1 known.

Out 1 of the DE 198 21 160 C1 a fastening system is known by means of a clamp having a formed between an upper and a central leg body receptacle for receiving the body member mounting surface, formed between the middle leg and a lower leg chassis receptacle for receiving the chassis surface and a first and a second thread in the lower leg having. Prefixing and final fixing takes place with the same screw, a first thread is present in the chassis, a second thread in the lower leg.

Finally, the reveals DE 102 52 992 A1 purely assembly method for fixing a body member with a slot on a chassis of a motor vehicle.

So far become fenders in most cases as Blechstanz- or Sheet deep drawn parts formed and as part of the pre-assembly and final assembly bolted to the frame of the motor vehicle. Aesthetic requirements and Structural specifications of new motor vehicles, however, require complex trained body elements with bulges, depressions, thickenings and the same. Pedestrian protection also requires that the body elements form energy-absorbing structures, which yield to a striking body when impacted.

It is therefore increasingly of interest, complex trained fenders with complicated geometries as plastic parts, in particular plastic injection molded parts train. These plastic parts offer a higher design freedom, are lighter (lightweight) as comparable sheet metal parts and allow energy absorbing To integrate structures into the profile. Unlike complex sheet metal profiles (Sheet metal profiles with complex geometries), which only in several production steps can be produced with separate tools, can be comparable Complex plastic parts in one step in an injection mold finished and are therefore much cheaper to manufacture. this applies especially for Small series.

plastic on the other hand has the disadvantage that this in comparison to steel about 6 to 7 times higher thermal expansion coefficient which is too undesirable thermal stress during assembly and operation. To avoid this thermal stress a plastic profile must always be fixed to a steel frame be that a relative movement between the body element and the frame (chassis) during the assembly and during operation is feasible.

Previous solutions Foresee that the plastic body elements in the pre-assembly initially with a screw on the chassis in two axes in a Cartesian Coordinate system be prefixed so that a compensation of thermal expansion in the third axis is still possible; Preferably, the body element in the Y and in the Z direction fixed, whereas a free space remains in the X direction. After a Heat treatment, e.g. when baking the paint, the body element is then in the frame Final assembly by a second screw also fixed in the X direction to the body element final to align with the chassis.

The Movement of the body element relative to the chassis is thus at least in one degree of freedom, preferably in the X direction Compensation of thermal stresses necessary.

to Realization of this clearance for the compensation of thermal expansions sees another from the prior art be known solution the Use of bolted to the body member cylindrical sleeves with in the lateral surface trained annular groove before. These sleeves are in openings used in the bodywork element, which has a larger diameter as the inner edge of the annular groove, so that the body element to realize the clearance to some extent in relation to the sleeve is movable in the annular groove.

A third solution in the prior art, that the body member has an inherent elasticity to compensate of thermal stresses having. For example, you can so-called "crowns" in the bodywork element be formed, which in the case of thermal stresses accordingly buckle or dent.

Increasingly be small joint dimensions and low manufacturing tolerances required that are compatible with the existing Do not or only with difficulty keep assembly procedures. The remaining Systems and methods also require extensive alignment of the body part in the context of the final assembly and are therefore very labor intensive. The known solutions enable thus, although a certain clearance for the heat balance, but at the same time to comply with modern manufacturing tolerances too inaccurate. Finally, none can compensate the known systems a Nachschwindung the plastic, which e.g. when heating the plastic body parts in KTL bath occur and a size reduction up to 2%.

outgoing Of the cited disadvantages of the invention lies. Task based, at least partially avoiding these disadvantages and a fastening system for fastening a body part to a chassis, that ensures sufficient fixation during pre-assembly, but at the same time the necessary clearance for the compensation of thermal stress provides and also easy to install.

• • Eine Klammer, die eine zwischen einem oberen und einem mittleren Schenkel ausgebildete Karosserieaufnahme zur Aufnahme der Karosserieelementmontagefläche, eine zwischen dem mittleren Schenkel und einem unteren Schenkel ausgebildete Chassisaufnahme zur Aufnahme der Chassisfläche, und ein erstes und ein zweites Gewinde im unteren Schenkel aufweist;
• • eine als Bundschraube ausgebildete Vorfixierungsschraube, die einen Bunddurchmesser und eine Bundhöhe aufweist, die höher oder gleich hoch ist wie die Karosserieprofilstärke, und sich für eine Vorfixierung durch das Langloch der Karosseriefläche und durch ein Loch in der Chassisfläche erstreckend mit dem ersten Gewinde verbinden lässt; und
• • eine als Bundschraube ausgebildete Endfixierungsschraube, die einen Bunddurchmesser und eine Bundhöhe aufweist, die höher oder gleich hoch ist wie die Karosserieprofilstärke, und sich für eine Endfixierung durch das Langloch der Karosseriefläche und durch ein Loch in der Chassisfläche erstreckend mit dem zweiten Gewinde verbinden lässt;

The fastening system according to the invention comprises, to solve this problem:

• • A bracket having a body receptacle formed between an upper and a middle leg for receiving the body member mounting surface, a formed between the middle leg and a lower leg chassis receptacle for receiving the chassis surface, and a first and a second thread in the lower leg;
• • a prefastening screw designed as a collar screw, which has a collar diameter and a collar height which is higher than or equal to the body profile thickness, and can be connected to the first thread for prefixing through the elongated hole of the body surface and through a hole in the chassis surface; and
• • an end-fixing screw designed as a collar screw, having a collar diameter and a collar height higher than or equal to the body profile thickness, and connectable to the second thread for end-fixing through the elongated hole of the body surface and through a hole in the chassis surface;

Of the upper leg has an upper passage for the Vorfixierungs- and the End fixation screw, which is slightly larger than the collar diameter. The middle leg has a central passageway for the prefixing and end fixation screw smaller than the collar diameter, and the slot is so much longer than the outside distance between the collar of the pre-fixation screw and the collar of the end fixation screw designed as the maximum occurring length expansion of the body element operational.

The inventive training guaranteed that after tightening the Vorfixierungsschraube the lower edge the federal government of Vorfixierungsschraube the frame holder for fixing the frame surface compressed in 2 axes, the Body element due to the Federal in the body seat but still along an axis (preferably the longitudinal axis) is movable to realize the clearance. Consequently, the covenant the prefixing screw is as high or higher than the material thickness of the Body element, at least in the attachment area.

The Clamp is first preassembled with the frame holder a frame surface or a trained at this area, e.g. a mounting bracket, postponed. The clip is now in the appropriately trained Slotted slidable. Then, the body element in the Body receptacle of the clip inserted or inserted and the pre-fixing screw is tightened. Now, the body element can be anticipated become. After pre-alignment, the body can undergo a heat treatment go through, in which the bodywork element also a possible Linear expansion experiences. After cooling is then in the context of Endfixierung the Endfixierungsschraube screwed into the second thread and tightened until the body element endfixiert is. After the final fixation a movement can only be done in one previously defined area in a given axis, preferably still a movement in the range of 2 to 4 mm in x-direction possible, around thermal expansions while normal operation without damage of the body element to compensate.

The slot is dimensioned so that the clip can move after placement on the body member to compensate for thermal expansion with clearance in this. After the final fixation, the clamp can move only limited in one axis; in a conventional fender with a length of 1000 to 1300 mm, this clearance in the x direction is about 3-4 mm to compensate for thermal stress at normal operating temperatures.

The Bodywork element is prefixed so that it aligns with the frame fixed in 2 axes and "load-proof" is, but one more Clearance for compensation of linear expansion in one direction, preferably the x-direction. Through this Clearance compensates tolerances due to thermal stress. Only through the screwed in during the final fixation Endfixierungsschraube the bodywork element becomes final fixed to the chassis while maintaining the clearance defined above. Put simply, an end fixation in one axis is permissible from the assembly effort, but no final alignment in different axes.

The to be considered Tolerances are natural dependent from the workpiece geometry. In the case of a usual fender with a length from 1000 mm to 1300 mm is a tolerance compensation range of 3 mm to 4 mm according to the invention feasible.

The inventive fastening system thus allows the compensation of cold shrinkage and thermal expansion without tension on the bodywork element. In the same way as the thermal expansions compensates for the fastening system according to the invention but also the Nachschwindung occurring when heating the plastic bodywork element of the plastic.

essential to the invention is that now the clip, the mounting threads for receiving the Prefixing screw and the Endfixierungsschraube has. in the Contrary to the prior art are the threads for receiving the Fixing screws thus no longer on the stationary chassis (Frame) formed, but as part of the bracket part of the relative movable fastening system. The frame thus determines for the first time no longer the tolerance.

In the preferred embodiment is the bracket - in the side view - as S-profile formed with an upper and a lower arc. Of the upper arc preferably forms the body seat and the lower Bow preferably the chassis mount. The bows are also defined here by three legs: an upper, a middle and a lower, which extend substantially horizontally in the installed position. In the upper thigh is the upper passage for provided the fixing screws. This pass is dimensioned that the collar of the screws, but not pass through the screw heads can. In the middle leg of the middle passage is provided for the fixing screws, which have a smaller diameter than the outer diameter of the screw collars. In the lower leg of the frame recording are finally the Thread for formed the fixing screws.

at an alternative embodiment Can the clip as E-profile be educated. The geometric design of the clip is irrelevant, as long as guaranteed is that at least the chassis mount of the clip is springy in itself is formed and further provided a body receptacle. This resilient design ensures that the chassis surface through Tightening the screws in the chassis mount prefixed in two axes and only by tightening the Endfixierungsschraube in the third Axis is endfixed while maintaining a low clearance. The Frets of Pre-fixing and final fixing screw ensure that the body element also at the complete Do not tighten these screws in the body mount of the clamp is trapped. At the same time, the fastening system ensures even after the final fixation due to the interaction of the length of the slot in the bodywork area and the axial distance between the lateral surfaces of the frets of Vorfixierungs- and Endfixierungsschraube that still a limited clearance in one Axis (preferably in the longitudinal axis (x-axis)) to compensate for thermal expansion is possible, the usual Operation occur. This can e.g. due to solar radiation done on the bodywork element.

to Simplify the assembly and exact positioning of the clamp on the frame can in the preferred embodiment between the chassis surface and the chassis receptacle positioning means may be formed, e.g. a tongue and groove connection.

The Clamp is preferably made entirely of sheet steel with resilient Properties, particularly advantageous from stainless spring steel. The training of glass fiber reinforced plastic or other tough plastics however, is also within the scope of the invention.

To avoid the above cited problems in the prior art and to solve the aforementioned problem, the invention also proposes an assembly method for attaching a body member to a chassis of a motor vehicle. The body element has a body surface with a slot and a body profile thickness; the chassis has a chassis surface with a chassis profile thickness. According to the invention for realizing a clearance in an axis, preferably in the longitudinal direction, a Klam having a formed between an upper and a middle leg body receptacle for receiving the body member mounting surface, a formed between the middle leg and a lower leg chassis receptacle for receiving the chassis surface and a first and a second thread in the lower leg. To connect this bracket with the body member and the chassis element trained as a collar screw Vorfixierungsschraube having a collar diameter and a collar height that is higher or equal to the body profile thickness, and trained as a collar screw Endfixierungsschraube used having a collar diameter and waistband that is higher or equal to the body profile thickness.

• – Aufschieben der Karosserieaufnahme der Klammer auf die Karosseriefläche,
• – Aufschieben der Chassisaufnahme der Klammer auf die Chassisfläche,
• – Eindrehen der Vorfixierungsschraube durch das Langloch und die Chassisfläche in das erste Gewinde,
• – Ausrichten des Karosserieelements am Chassis,
• – Vorfixieren des Karosserieelements durch Anziehen der Vorfixierungsschraube und
• – Endfixieren des Karosserieelements durch Eindrehen der Endfixierungsschraube in das zweite Gewinde.

The method according to the invention comprises the method steps:

• Pushing on the body receptacle of the clamp on the body surface,
• Sliding the chassis mount of the clamp onto the chassis surface,
• - Screwing the Vorfixierungsschraube through the slot and the chassis surface in the first thread,
• - aligning the bodywork element to the chassis,
• - Pre-fixing of the body element by tightening the Vorfixierungsschraube and
• - Final fixing of the body element by screwing the Endfixierungsschraube in the second thread.

For the expert It can be seen that it is to achieve the advantages of the invention It is not necessary that the clamp is actually on the bodywork and the chassis surface is deferred; It is crucial that the corresponding areas in the body mount and the chassis mount the clip added or introduced become.

Further Details, advantages and features of the invention can be the refer to the following part of the description, in which an embodiment the device according to the invention on the basis of three drawings closer explained becomes. The drawings show:

1 a perspective view of a fender and the clip according to the invention;

2 a perspective view of the fender according to 1 with fastened clamp;

3 a perspective view of the fender in the attachment to the chassis;

4 a perspective view of the fender attached to the chassis;

5 an enlarged perspective top view of the clip after insertion of Vorfixierungsschraube;

6 an enlarged plan view of the mounted on the chassis mated fender after the final fixation; and

7 an enlarged cross-section along the line VII-VII according to 5 ,

Same or equivalent parts are provided with the same reference numerals.

Accordingly, the fastening system according to the invention essentially comprises a clamp 2 , a prefixing screw 4 and an end fixing screw 6 , The clip 2 is used in the present example for mounting a mudguard 8th on the chassis of a car by means of a retaining bracket 32 used. From the fender 8th are shown to better illustrate the invention, only sections.

The pre-fixing screw 4 and the end fixing screw 6 are each designed as the same collar bolts with a same nominal and a same collar diameter. Such collar bolts consist of an axially extending threaded shaft with the nominal diameter, a trained above the threaded shaft cylindrical collar having a larger than the nominal diameter formed collar diameter and a collar height which is higher than the profile thickness of the body member. Above the collar, a screw head is formed whose diameter is greater than the collar diameter.

The clip 2 is - in side view - as S-profile with a body mount 22 (upper arch) and a chassis mount 40 (lower arc) formed. The shots are formed by three legs: an upper leg 12 , a middle thigh 14 and a lower leg 16 , The upper leg 12 , the middle thigh 14 and the lower thigh 16 are substantially parallel to each other and are connected by the arches. The clip 2 is manufactured as a one-piece bent part made of spring steel with a preferred material thickness of 1 mm. In the upper thigh 12 are a front passage hole acting as an upper passage 18 for the pre-fixing screw 4 and a back through hole 20 for the end fixing screw 6 intended. The diameters of the front through hole 18 and the rear passage hole 20 are smaller than the screw head of the prefixing screw 4 and the end fixation screw 6 but bigger than the frets of these screws. Escaping with the front through hole 18 and the rear through hole 20 are center passages in the middle leg 14 formed by which the Vorfixierungsschraube 4 and the end fixing screw 6 can pass through during assembly. The diameters of these center passages in the middle leg 14 However, they are smaller than the collar diameter of the prefixing screw 4 and the end fixation screw 6 so the prefixing screw 4 and the end fixing screw 6 with the underside of their frets on the middle leg of the bracket 2 in the installation position. The lower thigh 16 also aligns with the front through hole 18 and the rear through hole 20 a front threaded hole and a rear threaded hole. The threaded holes of the front threaded hole and the rear threaded hole correspond to the nominal diameters of the pre-fixing screw 4 and the end fixation screw 6 to record this. The threads can either be directly in the lower leg 16 be cut or formed by attached to the bottom of the bracket nuts.

During assembly, the body receptacle 22 the bracket 2 on a mounting surface 24 of the fender 8th postponed. In the assembly area has this mounting surface 24 a slot 26 for the passage of the Vorfixierungsschraube 4 and the end fixation screw 6 on. Furthermore, is transverse to the slot 26 at the bottom of the mounting surface 24 formed a guide rib, not shown. Corresponding to this guide rib is on the upper leg of the clip 2 one transverse to the longitudinal direction of the clip 2 extending guide groove formed, in which this guide rib of the fender 8th in installation position engages the clip 2 in relation to the fender 8th to position exactly and defined.

For a more accurate adjustment during pre-assembly can in the slot 26 also a sliding plate 27 be arranged. These sliding plates 27 with a through hole for the prefixing screw 4 dissolves when screwed on and allows for the pre-fixing a movement of the fender 8th within preset dimensions.

The 2 shows the clip 2 after sliding onto the mounting surface 24 of the fender 8th ,

The fender 8th will now be together with the bracket 2 according to 3 on a mounting surface of the retaining clip 32 , which is bolted to a chassis, not shown. The headband 32 consists of a folded sheet metal profile with a horizontal section forming the mounting surface 34 two vertical sections extending transversely from the horizontal section on both sides 36 and again transverse to the vertical sections 36 outwardly extending mounting tabs 38 with through holes for mounting screws on the chassis. Alternatively, the bracket 2 be pushed directly onto a mounting surface on the chassis.

Then the Vorfixierungsschraube 4 in the bracket 2 screwed. When tightening the pre-fixing screw 4 the collar of the prefixing screw squeezes 4 the middle leg 14 against the lower leg 16 and clamps the horizontal section 34 of the retaining clip 32 between through the middle leg 14 and the lower leg 16 trained chassis mount 40 a for prefixing the fender 8th on the chassis. Due to the long hole 26 in the mounting area 24 of the fender 8th However, this is still movable in the x direction. Because the collar of Vorfixierungsschraube 4 laterally on the inner surfaces of the oblong hole 26 is present, is a misalignment of the fender 8th in relation to the chassis in the y-direction and in the z-direction no longer possible. The fender 8th is therefore prefixed.

After this prefixing, the chassis can undergo a heat treatment in which higher temperatures, for example for fixing the paint on the body parts, can also cause a thermal expansion of the body part in the longitudinal direction (x-direction). Such thermal expansion can be compensated by the fastening system according to the invention. To the desired and limited clearance of the fender 8th in relation to the chassis, is the collar of the pre-fixing screw 4 dimensioned so that the body receptacle 22 and the screw head of the prefixing screw 4 the fender 8th do not squeeze when fully tightened.

After cooling the fender 8th the final fixation takes place. For this only the Endfixierungsschraube must 6 into the end fixation thread on the clamp 2 be screwed. Thus, the mobility of the fender 8th limited in relation to the chassis so that a limited movement is possible only in the longitudinal direction to a predetermined extent. This predetermined amount is defined by the length of the slot 26 in relation to the distance between the farthest distance of the outer diameter of the collars of the fixing screws 4 . 6 , Usually, the slot is about 2 to 4 mm longer than the outer distance of the collars of the fixing screws 4 . 6 to realize a limited free dimension of about 2 mm in both directions in the longitudinal direction.

In the described preferred embodiment of the invention, the prefixing screw is 4 and the end fixing screw 6 the same, which also causes the through holes and the threads in the bracket 2 are the same. However, it is also within the scope of the invention that the Vorfixierungsschraube 4 and the end fixing screw 6 may be formed differently, what differently shaped through holes and threads in the bracket 2 brings with it.

The inventive fastening system and in particular, provide the clip according to the invention thus a fastening system for the attachment of a plastic injection molded part designed as a body part on a chassis ready, which in a simple way an exact Pre-assembly of the body part in relation to the chassis for load-resistant Initial alignment of the body part on the chassis allows. After a heat treatment of the fender and an associated thermal expansion allows the fastening system a simple and fast final fixation Inserting the End Fixation Screw. The system thus enables a load-proof pre-assembly, but the thermal expansions without jarring in the material compensated.

Of the The subject of the present invention is not exclusive the subject of the individual claims, but from the combination of individual claims among themselves. All in the documents - including summary - disclosed Information and features, in particular those shown in the drawings spatial Training, are claimed as essential to the invention, as far as individually or in combination with the prior art are.

2

clip

4

Vorfixierungsschraube

6

Endfixierungsschraube

8th

fender

12

upper leg

14

middle leg

16

lower leg

18

front Through Hole

20

rear Through Hole

22

body recording

24

mounting surface

26

Long hole

27

sliding plate

32

headband

34

Horizontal section

36

vertical section

38

mounting tab

40

chassis recording

Claims (7)

Fastening system for fastening a body element which has a body surface with a slot ( 26 ) and a body profile thickness, on a chassis of a motor vehicle having a chassis surface with a chassis profile thickness, by means of a screw, designated by a bracket ( 2 ), one between an upper and a middle leg ( 12 . 14 ) formed body receptacle ( 22 ) for receiving the body element mounting surface, one between the middle leg ( 14 ) and a lower leg ( 16 ) formed chassis receptacle ( 40 ) for receiving the chassis surface, and a first and a second thread in the lower leg ( 16 ), designed as a collar screw prefixing screw ( 4 ), which has a collar diameter and a waist height that is higher than or equal to the body profile strength, and for a Vorfixierung through the slot ( 26 ) of the body surface and through a hole in the chassis surface extending to the first thread is connectable, designed as a collar screw Endfixierungsschraube ( 6 ), which has a collar diameter and a waist height that is higher than or equal to the body profile strength, and for a final fixation through the slot ( 26 ) of the body surface and through a hole in the Chas sisfläche extending connectable to the second thread, wherein the upper leg ( 12 ) an upper passage for the prefixing and the end fixation screw ( 4 . 6 ), which is slightly larger than the collar diameter, wherein the middle leg ( 14 ) a center passage for the prefixing and end fixation screw ( 4 . 6 ), which is smaller than the collar diameter, and wherein the slot ( 26 ) so much longer than an outer distance between the collar of Vorfixierungsschraube ( 4 ) and the collar of the final fixing screw ( 6 ) is, as the maximum occurring longitudinal extent of the body element in operation. Fastening system according to claim 1, characterized in that the clip ( 2 ) is formed as an S-profile with an upper and a lower arc, and that the upper arch the body mount ( 22 ) and the lower arch the chassis mount ( 40 ). Fastening system according to one of the preceding claims, characterized in that the body mount ( 22 ) and / or the chassis mount ( 40 ) are designed as inserts. Fastening system according to one of the preceding claims, characterized in that between the bracket ( 2 ) and the Chas photograph ( 40 ) Positioning means are formed. Fastening system according to one of the preceding claims, characterized in that the clip ( 2 ) Steel. Fastening system according to one of the preceding claims, characterized in that the upper passage and / or the middle passage for the prefixing screw ( 4 ) and the end fixing screw ( 6 ) are formed einlöchig or two-hole. A mounting method for mounting a body member having a body surface with a slot and a body profile thickness, on a chassis of a motor vehicle having a chassis surface with a chassis profile thickness, using a bracket ( 2 ), one between an upper and a middle leg ( 12 . 14 ) formed body receptacle ( 22 ) for receiving the body element mounting surface, one between the middle leg ( 14 ) and a lower leg ( 16 ) formed chassis mount ( 40 ) for receiving the chassis surface, and a first and a second thread in the lower leg ( 16 ), designed as a collar screw prefixing screw ( 4 ), which has a collar diameter and a waist height that is higher than or equal to the body profile thickness, and an end fixation screw designed as a collar screw ( 6 ), which has a collar diameter and a waist height which is higher than or equal to the body profile thickness, comprising the steps of: - slipping on the clip ( 2 ) on the body surface, - sliding the clamp onto the chassis surface, - screwing in the pre-fixing screw ( 4 ) through the slot and the chassis surface in the first thread, - Aligning the body member to the chassis, - Pre-fixing of the body member by tightening the Vorfixierungsschraube ( 4 ) and - final fixing of the body element by screwing in the end fixing screw ( 6 ) in the second thread.