WO2017222439A1

WO2017222439A1 - Panel for vehicle

Info

Publication number: WO2017222439A1
Application number: PCT/SE2017/050478
Authority: WO
Inventors: David H:son BOURGHARDT
Original assignee: Ab Bröderna Bourghardt
Priority date: 2016-06-23
Filing date: 2017-05-11
Publication date: 2017-12-28
Also published as: SE540149C2; SE1650912A1

Abstract

The disclosure concerns a vehicle panel (2) arranged to be mounted on a vehicle (1). The panel (2) comprises indentations (7). The disclosure also concerns a vehicle (1) comprising such a vehicle panel (2), as well as method for manufacturing such a vehicle panel (2).

Description

TITLE

Panel for vehicle

TECHNICAL FIELD

The invention relates to a set of vehicle panels for mounting on a ground vehicle. BACKGROUND ART

In order to reduce fuel consumption, weight and aerodynamic drag are two important factors. To reduce aerodynamic form drag it is previously known to include or add rigid/stiff vehicle panels to the body structure of a vehicle such as tractor trailer trucks and trailers. Such panels can be placed in the front, on top, along the sides of or under the vehicle. However, such rigid vehicle panels also add weight to the vehicle or trailer, which in turn increases the fuel consumption. DESCRIPTION OF THE INVENTION

With reference to background art, there is a need to find a light weight, aerodynamic and rigid panel in order to reduce fuel consumption. The present invention relates to a rigid vehicle panel with a surface structure comprising indentations with reinforcing side walls extending from the surface between the indentations to the bottom of the indentations. The indentations give increased strength which has the advantage that the panel can be made thinner to reduce weight. The indentations have a further advantage because it also reduces drag. Hence, a rigid vehicle panel comprising indentations according to the invention solves the two-folded problem with reduced drag and reduced weight. The panel is in the form of a three dimensional material having indentations in the form of concave recesses on one side and corresponding elevations on the other side. The indentations are hereinafter also called dimples. The dimples have side walls extending from the surface between the dimples to the bottom of the dimple. The side walls function as a structural element that reinforces the panel. If pressure is applied towards the panel surface the side walls of the dimples take up the load. The bottom portion of the dimple is not subject to as high forces as the portion of the side wall being closest to the surface between the dimples. This has the advantage that the material thickness of the initial part of the side walls is made thicker than the bottom portion which means that with the same amount of material in the panel, the panel is given more strength than a panel with an equally distributed material thickness. The advantage of the possibility of allocating material also gives the possibility of reducing material in general, should it be that the material thickness in the side walls are enough then the material in the bottom of the dimple could be reduced. Furthermore, the increased strength of the panel has the advantage that less material needs to be used for the panel as a whole, which has the advantage of reduced weight. Reduced material consumption also has the advantage of being more environmentally friendly and reducing cost.

Here, the surface between the dimples refers to the main surface of the vehicle panel being free from indentations.

The dimples are advantageously formed with a polygon edge or boundary line towards the flat surface between the recesses. The polygonal shape has proven to give increased aerodynamic performance, with reduced drag for the panel in a wind tunnel. Tests have shown very good results for an lcosagon, i.e. a polygon with 20 sides. However, other polygonal shapes could be possible should they have about 20 sides. A regular polygon has been proven in various tests to give the stated advantages. However, it could be that the polygon could have an irregular shape to give increased strength compared to a flat surface and possibly also at least an improved aerodynamic performance. Furthermore, other shapes could also be possible, for example round shaped indentations to give at least increased strength compared to a flat surface and possibly also at least an improved aerodynamic performance. The interior side walls and bottom of the dimple create a shape that can be essentially round like a part of a sphere but may also be boxy with sharp edges or a combination thereof.

According to one example, the surface structure comprises predetermined zones comprising dimples. The position(s) of the zones are dependent on the form of the panel and on the position of the panels on the vehicle. The zone(s) are advantageously positioned where the air velocity relative the vehicle is high. When the air velocity is high, the air pressure is high, and consequently the need for a strong structure is high. Furthermore, when the air velocity is high, there is an increased need to create a more aerodynamic panel. The dimples have proven to give an increased aerodynamic effect in addition to increased strength of the panel.

According to one example, the entire vehicle panel consists of dimples with the advantages stated above. For both examples of dimpled zones and fully dimpled panel, the amount of dimples per surface area is advantageously more than 50% in the dimpled zones. The distance between the dimples are in the range of 1 to 50 mm, and preferably 5-20 mm, edge to edge measure. The panel is rigid which here means that it is essentially self-supported, i.e. does not need to have an exterior supporting structure per se. However, the panel could be mounted on a support structure when mounted to a vehicle. Since the panel has increased strength due to the dimples, the support structure can be reduced which in turn gives a more light weight support structure and thus less fuel consumption. The support structure may be reduced by being thinner and/or may have a reduced number of parts due to the increased strength of the panel. The main panel body may be flat or bent, or a combination of flat and/or bent parts. Hence, the main panel body may have a two-dimensional extension, i.e. flat in a plane in a Cartesian coordinate system, or the main panel body may have a three dimensional extension, i.e. having a surface following curvilinear coordinates. The main panel body or parts of the main panel body may then follow the shape of a sphere, cone, cylinder or any other three dimensional shape.

Load simulations performed in Autodesk Inventor show a possible reduction in part material volume by 30% with maintained strength compared to a flat panel without dimples. The dimpled surface structure also creates advantageous aerodynamic performance.

Aerodynamic flow simulations performed in Ansys show improved airflow and a reduction of 2,6% in form drag, C_d, compared to a panel with a flat surface structure.

According to one example, the indentation has a polygon shape with 20 sides and a diameter in the range of 1 to 100 mm, preferably 25-75 mm. The diameter refers to the longest distance possible to measure over the dimple from edge to edge. The depth of the indentation is in the range of 0.1 to 50 mm, and preferably 2-20 mm. The edge of the indentation connecting to the main surface between the indentations of the panel may be sharp or has a radius in the range of 0.1 to 10 mm, and preferably 0.1 to 5 mm. The distance between the indentations is in the range of 1 to 50 mm, and preferably 5-20 mm, edge to edge measure. In a tested panel with the stated advantages, the thickness of the side wall of the dimples has been 3,5mm and the thickness of the bottom of the dimple has been 2,5mm. It should be noted that this is only an example of a tested panel with the stated advantages, and the example shows that the side walls can be thicker than the bottom of the dimple with increased strength compared to a flat panel. Hence, variations of the material thickness can be made dependent on parameters such as choice of material, desired strength of panel etc. The dimpled panels are especially advantageous for materials that can be manufactured via moulding. Moulding has the advantage of being a simple process per se that can be controlled to vary the material thickness in the panel and in the dimples. The molding process will be possible to control to optimize the panel for strength by having as much material as possible in the side walls and as little material as possible in the horizontal bottom as been discussed above.

The preferred production process is based on:

• Two liquid base components

Dosing under controlled parameters, 1 : 1

· Mixing of component A & B at entry of mould

Preheated metal mould

Low viscosity, low pressure build-up,

Fast curing time

Good surface finish

Specifically, one example method in a reaction injection moulding process for manufacturing a vehicle panel being three dimensional comprising indentations as discussed above, comprises the following method steps:

pre-heating a metal mould having a plurality of protrusions formed on an inner surface of the mould, which protrusions are arranged for forming a plurality of indentations on the finished panel;

mixing of a first liquid polymer component and a second liquid polymer component; injecting the polymer mixture in the mould and waiting until the polymer mixture has cured into a three dimensional vehicle panel comprising indentations; and

removing the finished vehicle panel from the mould.

The production process further allows long flows in the mould, making it possible to produce large parts. According to one example, the vehicle panel includes a single top coat to be able to customize the color of the panel with as little weight added as possible.

BRIEF DESCRIPTION OF DRAWINGS

The invention will below be described in connection to a number of drawings, in which:

Fig. 1 schematically shows an overview of a vehicle fitted with vehicle panels;

Fig. 2 schematically shows an example of a vehicle panel; Fig. 3 schematically shows an example of a vehicle panel with zones of dimples;

Fig. 4 schematically shows an example of a cross section of the present surface structure invention;

Fig. 5 schematically shows a traction unit/truck with a trailer having vehicle panels on various positions on the vehicle;

Fig. 6 schematically shows a method for manufacturing a vehicle panel according to the disclosure, and in which;

Fig. 7 schematically shows process equipment for manufacturing a vehicle panel according to the disclosure. DETAILED DESCRIPTION OF DRAWINGS

Various aspects of the disclosure will hereinafter be described in conjunction with the appended drawings to illustrate and not to limit the disclosure, wherein like designations denote like elements, and variations of the described aspects are not restricted to the specifically shown embodiments, but are applicable on other variations of the disclosure.

In the figures, like items are denoted with the same numbers.

Fig. 1 schematically shows an overview of a vehicle 1 fitted with vehicle panels 2. According to one example embodiment of the disclosure one vehicle panel 2 forms a roof air deflector 51 positioned on the roof 41 of a cab 4 of a vehicle 1 in the form of a traction unit 1 1 connected to a trailer 5. The traction unit 11 is also called tractor, tractor trailer, truck and tractor trailer trucks and refers to the vehicle unit that is intended to pull the trailer 5. Fig. 1 also shows an example embodiment where a vehicle panel 2 is positioned on each side 42 of the cab 4 rear of the cab doors 6 functioning as side air deflector 52.

Fig. 2 schematically shows an example of a vehicle panel 2 in form of a roof air deflector 51. The vehicle panel 2 is arranged to be mounted on a vehicle according to figure 1 and figure 5. The panel 2 is an optimized custom moulded three dimensional panel comprising a large amount of indentations 7. In the example embodiment of fig. 2 the panel 2 in form of a roof air deflector comprises about 500 to 2000 indentations 7, specifically about 1000 to 1500 indentations 7. In the example embodiment of fig. 2 the panel 2 in form of a roof air deflector 51 comprises a front surface 10, an inclined top surface 11 and left and right side surfaces 12, 13. The surfaces 10, 11 , 12, 13 are interconnected to form the roof air deflector 51. The indentations 7 can be located on all said surfaces 10, 11 , 12, 13 or only on some of said surfaces 10, 1 1 , 12, 13 depending on the circumstances. In the example embodiment of fig.2 the indentations 7 are located on all said surfaces 10, 1 1 , 12, 13.

Fig. 3 schematically shows an example vehicle panel 7 comprising a zone 15 free of indentations 7 and a plurality of zones 16 comprising indentations 7. The position of the zones 16 comprising indentations 7 are advantageously positioned where the air velocity relative the vehicle is high because the dimpled zones give both increased strength and improved aerodynamic performance of the panel.

With reference to figures 1-7, the amount of the indentations per surface area is preferably more than 50% in a dimpled zone 16, i.e. a zone 16 comprising indentations 7. In particular, the amount of the indentations per surface area may be in the range of 50 - 90 %, in a dimpled zone 16, specifically 60 - 85 %.

Fig. 4 schematically shows an example of a cross section of a panel according to the disclosure at a zone comprising indentations 7. The panel 2 is in the form of a three dimensional material having indentations 7 in the form of concave recesses 17 on one side and corresponding elevations 8 on the other side. The panel 2 is preferably positioned on the vehicle such that the indentations 7 face the exterior side of the panel, i.e. engaging the airflow.

In the example embodiment of fig. 4 the indentation 7 has a polygon shape with a diameter 20 in the range of 1 to 100 mm, preferably 25-75 mm. The diameter refers to the longest distance possible to measure over the dimple from edge to edge. The depth 21 of the indentation 7 may be in the range of 0.1 to 50 mm, and preferably 2-20 mm. The edge 22 of the indentation 7 connecting to the main surface 23 between the indentations of the panel 2 may be sharp or has a radius in the range of 0.1 to 10 mm, and preferably 0.1 to 5 mm. The distance 28 between the indentations 7 is in the range of 1 to 50 mm, and preferably 5-20 mm, edge to edge measure. Each concave recess 17 in the example embodiment of fig. 4 comprises an interior side wall 24 and a bottom wall 25, wherein the interior side wall 24 has a shape that is essentially round like a part of a sphere and the bottom wall 25 is essentially flat. However, if the indentation 7 has a polygon shape, then the interior of the recess could be arranged to reflect the polygon pattern with sections of interior side walls 24 starting at the edge/rim/boundary line and running in a narrowing pattern towards the bottom wall 25. The narrowing sections could end in a point in the middle of the bottom wall 25. The curvature of the interior side walls 24 determines where the bottom wall 25 starts and finishes. As defined here, the bottom wall 25 is flat and the side walls 24 are curved, which means that should the narrowing side walls be curved all the way to the end point then the bottom wall 25 becomes just a point where all the side walls meet. The walls 24 of the indentation/dimple extend from the surface between the dimples to the bottom of the dimple and function as a structural element that reinforces the panel.

Fig. 5 schematically shows a traction unit/truck 1 1 with a trailer 5 having vehicle panels on various positions on the vehicle in addition to the panels shown in figure 1. Fig. 5

schematically shows an example embodiment where a vehicle panel 2 is positioned on each side of the cab 4 on the bottom part 43 of the traction unit 1 1 functioning as a truck side fairing 53. Fig. 5 also schematically shows a further example embodiment of the vehicle panel 2 being located on the trailer 5 being pulled by the traction unit 11. The trailer 5 comprises vehicle panels 2 functioning as skirt panels 54 or trailer side fairings 54 along the lower edges 44 of the long sides of the trailer 5. The panels 2 preferably extend along a part of or the entire length of the trailer 5. Hence, figure 5 schematically shows a number of different opportunities for the vehicle panel that can be used alone in one position or in a combination of positions. The disclosure further relates to a method for manufacturing a vehicle panel 2 according to the disclosure. The method is referred to as reaction injection moulding and comprises a plurality of steps, as schematically illustrated in fig. 6. The method of manufacturing will also be described with reference to process equipment schematically shown in fig. 7. A first step 60 includes providing and pre-heating a metal mould 65 having a plurality of protrusions formed on an inner surface of the mould, which protrusions are arranged for forming a plurality of indentations 7 on the finished vehicle panel 2. The mould thus has an interior shape that is arranged to produce a vehicle panel 2 having a three dimensional shape.

A second step 61 involves mixing under pressure of a first liquid polymer component A and a second liquid polymer component B. Mixing may be performed using any suitable mixing device 64. The dosing of the first liquid polymer component A relative to the second liquid polymer component B may for example be controlled to about 1 : 1 , but the dosing relationship may vary depending on the type of polymer components used, such as for example in the range of 1 :3 - 3:1 , specifically in the range of 1 :2 - 2:1. The first and second liquid polymer components A, B include thermosetting polymers, such as dicyclopentadiene or the like. Due to the inclusion of thermosetting resin the mixture of first and second liquid polymer components A, B may have a relatively low viscosity, such that large, light-weight and thin- walled items can be successfully produced. A third step 62 includes injecting the polymer mixture into the mould 65 and waiting until the polymer mixture has cured into a three dimensional vehicle panel 2 comprising indentations 7.

A fourth step subsequently involves removing the finished vehicle panel 2 from the mould 65.

While specific examples have been described in the disclosure and illustrated in the drawings, it will be understood by those of ordinary skill in the art that various changes may be made, and that mixing and matching of features, elements and/or functions between various examples is expressly contemplated herein so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise, above. Similarly, the method steps described in relation to the manufacturing process merely describe one example process, and other process steps may be added or combined into larger steps. Therefore, it is intended that the present disclosure not be limited to the particular examples illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out the teachings of the present disclosure, but that the scope of the present disclosure will include any embodiments falling within the foregoing description and the appended claims.

Claims

1. A vehicle panel (2) arranged to be mounted on a vehicle (1), the panel (2), characterized in that the panel (2) being three dimensional comprising indentations (7) with reinforcing side walls (24) extending from the surface (23) between the indentations (7) to the bottom (25) of the indentations (7).

2. A vehicle panel (2) according to claim 1 , wherein the material thickness of the initial part of the side walls (24) is made thicker than the bottom portion (25).

3. A vehicle panel (2) according to claim 1 or 2, wherein the indentations (7) preferably has a circular or polygon shape projected on the vehicle panel surface with a diameter or width in the range of 1 to 100 mm, and preferably 25-75 mm.

4. A vehicle panel (2) according to any one of the preceding claims, wherein the depth (21) of the indentations (7) is in the range of 0.1 to 50 mm, and preferably 2- 20 mm.

5. A vehicle panel (2) according to any one of the preceding claims, wherein the edge (22) of the indentations (7) connecting to the essentially flat surface (23) of the panel (7) is sharp or has a radius in the range of 0.1 to 10 mm, and preferably 0, 1 to 5 mm.

6. A vehicle panel (2) according to any one of the preceding claims, wherein the side walls (24) and bottom wall (25) of the indentations (7) create a shape that is essentially round like a part of a sphere but may also be boxy with sharp edges or a combination thereof.

7. A vehicle panel (2) according to any one of the preceding claims, wherein the indentations (7) are polygonal in shape.

8. A vehicle panel (2) according to any one of the preceding claims, wherein the amount of the indentations (7) per surface area is more than 50% in dimpled zone (16).

9. A vehicle panel (2) according to any one of the preceding claims, wherein the distance (28) between the indentations (7) are in the range of 1 to 50 mm, and preferably 5-20 mm, edge to edge measure.

10. A vehicle (1) comprising a vehicle panel (2) according to any one of claims 1-9.

1 1. Method for manufacturing a vehicle panel (2), being three dimensional, comprising indentations (7) and arranged to be mounted on a vehicle (1) in a reaction injection moulding process, the method comprising:

pre-heating a metal mould having a plurality of protrusions formed on an inner surface of the mould, which protrusions are arranged for forming a plurality of indentations (7) on the finished panel (2);

mixing of a first liquid polymer component and a second liquid polymer component;

injecting the polymer mixture in the mould and waiting until the polymer mixture has cured into a three dimensional vehicle panel (2) comprising indentations (7); and

removing the finished vehicle panel (2) from the mould.