FR3081388A1 - REINFORCED LIGHT JOINT FOR BODY COMPONENT - Google Patents

Abstract

The invention relates to a joint (8) of a bodywork part (2) of a motor vehicle comprising: - a matrix made of a transparent or translucent material, and - reinforcing fibers (10) extending in the matrix, the seal being elastically deformable.

Description

The present invention relates to the field of motor vehicle body parts. The invention relates more specifically to body parts comprising a light source visible from outside the vehicle, for example forming a light signature.

It is known to produce bodywork parts comprising at least one light source, for example to form a light signature. In such cases, the light source is protected by a portion of the part made of transparent plastic. The light source can for example be placed in a recess in the external face of the bodywork part and behind the transparent portion or alternatively sandwiched between two parts of the transparent portion. The transparent portion can then be mounted on a bodywork part, for example opaque. An opaque body part is thus obtained comprising a transparent portion capable of letting the light emitted by the light source protected by the transparent portion.

However, body parts as described above have certain drawbacks.

Indeed, the transparent portion is made of a relatively rigid material. Consequently, the latter can turn out to be brittle, which leads to limiting its dimensions in order to reduce the risks of breakage. It is therefore difficult to obtain a transparent portion having particular dimensions, for example of a large length and of a reduced width. This difficulty in handling a transparent portion having dimensions like those mentioned above can particularly pose a problem in the context of producing a light signature, generally long and fine. The manufacturing process can be unprofitable and the more complex assembly process (manufacturing a portion of the part in isolation, portion attached to the main body of said part).

In addition, the transparent piece of rigid plastic can pose problems in terms of sealing. Indeed, in the presence of outcrop defects, the risks of which increase by increasing the dimensions of the transparent portion, water can infiltrate passing on either side of the transparent portion, which can lead to a malfunction of the light source and / or to a deterioration in the quality of the light signature.

The invention aims to remedy these drawbacks by providing a transparent portion more easily manipulated and capable of ensuring a good seal while obtaining an optimal aesthetic appearance at the body part.

To this end, the invention relates to a joint of a motor vehicle body part comprising:

- a matrix made of a transparent or translucent material, and

- reinforcing fibers extending in the matrix, the seal being elastically deformable.

Thus, one can obtain a bodywork part whose transparent portion (Le. The seal) is more easily manipulated during assembly due to its ability to deform elastically. This makes it possible, for example, to envisage producing a long, fine and non-rectilinear light signature (presence of a curve for example) without encountering the problem of the rigidity of the transparent portion according to the prior art. In addition, the seal can also be force-fitted into a slot in the bodywork and remain compressed in the slot, which guarantees a good seal. Finally, the presence of reinforcing fibers guarantees stability of the joint, especially over long lengths.

The joint according to the invention can also comprise at least one of the following characteristics:

- the joint is longer than 200 millimeters, preferably equal to 2 meters;

- The joint is between 5 and 10 millimeters wide, preferably equal to 6 millimeters;

- the reinforcing fibers extend over the entire length of the joint;

the reinforcing fibers are mutually parallel in a direction parallel to a longitudinal axis of the joint;

- a light source is integrated in the joint;

- which the reinforcing fibers comprise optical fibers; and the seal is made of a material chosen from an elastomeric material or a silicone.

The invention also relates to a method of manufacturing a seal according to the invention comprising the following steps:

the stretched reinforcing fibers are conveyed to an extruder,

the reinforcing fibers are guided in the extruder by means of a cable guide, and

- the reinforcing fibers are covered with plastic.

The method according to the invention can also comprise at least one of the following characteristics:

the process comprises, following the covering of the reinforcing fibers with the plastic, a step of shaping the joint comprising the following steps:

the reinforcing fibers and the plastic material pass through a first part of a die, the first part placing the reinforcing fibers in the plastic material, and

- the reinforcing fibers and the plastic material pass through a second part of the die, the second part conforming the material to the shape of the joint; and

- the process includes, following the joint shaping step, the following steps:

- the seal passes through a cooling zone, and

- the seal is rolled up and / or cut.

The invention also relates to a motor vehicle body part comprising:

- a main body,

- at least one slot in the main body,

- at least one light source capable of diffusing light through the slit, and at least one seal according to the invention.

The bodywork part according to the invention may further comprise the following characteristic: the seal comprises at least one relief capable of collaborating with a relief of complementary shape present on the main body.

We will now present an embodiment of the invention given by way of example, with the support of the appended figures in which:

FIG. 1 is a perspective view of a portion of a bodywork part according to the invention,

FIG. 2 is a perspective view of a portion of the joint of the bodywork part according to the invention, and

- Figure 3 is a schematic representation of the different stages of the manufacturing process of the joint of the bodywork part according to the invention.

We now refer to Figure 1 which shows a portion of a bodywork part 2 (for example a bumper) comprising a main body 4. This main body 4 can be made of plastic, for example in a thermoplastic material such as polypropylene (commonly used for the production of plastic body parts). The main body 4 comprises a slot made on its external face, that is to say the face visible from outside the vehicle when the bodywork part 2 is mounted on a motor vehicle. The slot can be of any shape depending on the desired function for the lighting (license plate lighting, light signature, etc.).

A light source 6 can be fixed inside the slot. It can be glued, screwed, clipped, etc. This light source is capable of diffusing light inside the slot and towards the outside of the vehicle. The scattered light is conventionally visible light (wavelength between about 400 nm and 700nm). Alternatively, the light source 6 can be placed at each end of the slot.

The slot of the bodywork 2 is closed by a seal 8. The latter allows, thanks to its position (preferably flush with the outer face of the bodywork 2), to obtain an optimal aesthetic appearance at level of finished bodywork part 2. The latter also protects the light source if necessary and ensures optimal light distribution. Indeed, it is made of a material giving it an ability to deform elastically. The matrix of the seal 8 is for example made of an elastomeric polymer or else a silicone. It is therefore possible to provide a slot with a width less than that of the seal 8 and this so that the latter is compressed in the slot after its assembly in order to ensure a good seal at the slot. The seal 8 is suitable for letting the light emitted by the light source 6 pass, it can be transparent or even translucent. In general, the material chosen gives the seal 8 certain properties, for example, and in addition to light transparency, UV resistance or even heat resistance.

The deformation capacity of the seal 8 also makes it possible to envisage having a non-rectilinear slot (which can commonly be the case in the presence of curved body parts). It is therefore possible to deform the seal 8 to conform to the shape of the slot. The deformation capacity of the joint 8 also makes it possible to envisage making a slit having particular dimensions, for example a slit of great length and of small width. Indeed, the joint can be of a length greater than or equal to 200 millimeters or even of a length equal to 2 meters. Its width can be between 5 and 10 millimeters, preferably equal to 6 millimeters. It is therefore possible to produce a seal 8 able to collaborate with a slot made in order to provide the bodywork part 2 with a light signature. Above all, it is possible to achieve a long and fine light signature by only needing to use a single joint 8.

The joint 8 comprises reinforcing fibers 10, such as for example glass fibers (we choose reinforcing fibers which do not alter the transparency of the joint 8 to the light emitted by the light source). These reinforcing fibers provide a certain dimensional stability so that the joint is not too soft and therefore more easily handled. A person skilled in the art will know how to adjust the percentage of reinforcing fibers 10 in the joint 8 in order to obtain the optimal deformation capacity of the joint 8. The reinforcing fibers 10 extend in the matrix of the joint 8, for example by being molded in the latter.

The reinforcing fibers 10 can extend over the entire length of the joint 8 and in a homogeneous manner, so as not to constitute a point of weakness at the level of the latter. In addition, the reinforcing fibers 10 may be parallel to each other in a direction parallel to a longitudinal axis of the joint 8. This makes it possible to preserve the transparency of the joint 8 to light.

In a variant of the invention, it is possible to integrate the light source directly into the joint 8 during its manufacture. It is for example possible to overmold the light source 6 in the joint 8.

Advantageously, it is possible to use reinforcing fibers 10 also acting as a light source 6. It is for example possible to use optical fibers as reinforcing fibers 10. The optical fibers allow the properties of the joint 8 (transparency to light, mechanical strength, etc.) and directly generate the light to produce, for example, the light signature.

In order to maintain the seal 8 in position in the slot, the latter may include one or more grooves 12 capable of collaborating with one or more protuberances formed on the walls of the main body 4 at the level of the slot. It is also possible to reverse this arrangement, the joint 8 comprising one or more protuberances capable of collaborating with one or more grooves formed on the walls of the main body 4 at the level of the slot.

So that the seal 8 meets the conditions in terms of transparency and mechanical strength set out above, the manufacturing process of the latter is adapted as follows.

The seal 8 is produced by continuous extrusion (this is a conventional extrusion process). The first step is to stretch the reinforcing fibers 10 upstream of the extruder. They are stretched and for example parallel to each other. The goal is to determine the position that the reinforcing fibers 10 will have in the joint 8, for example that observed in FIG. 2. This first step is materialized by the reference 16 in FIG. 3. It is a continuous supply of reinforcing fibers 10 so that the joint 8 includes reinforcing fibers 10 over its entire length.

In order to ensure that the reinforcing fibers 10 will be placed in the right place in the joint 8, they then pass through a cable guide 18 (step 20 of the method of Figure 3). The tensioned and guided reinforcing fibers 10 are conveyed in the extruder. It is possible to perform a cleaning of the reinforcing fibers 10 at this level by providing a zone dedicated to this.

The reinforcing fibers 10 stretched and suitably arranged with respect to each other are subsequently covered by the material forming the seal (elastomer or silicone for example) passing at the level of the extrusion screw (lateral supply) , this being materialized by the arrow 22 in FIG. 3.

The reinforcing fibers 10 embedded in the plastic pass through two parts 24 and 26 of a die. The die at the end of the extruder screw is suitable for aligning the reinforcing fibers 10. The core is broken down to guide the reinforcing fibers 10 without affecting the mechanical integrity of the seal 8 formed. The first part 24 of the die therefore comprises lines (or slits) making it possible to suitably place the reinforcing fibers 10 in the material forming the seal 8.

The first part 24 of the die is heated. The reinforcing fibers 10 are always guided inside this part 24. They are released during the passage through the second part 26 of the die, this part 26 contributing to the shaping of the joint 8 by only taking up the profile. without guide for the reinforcing fibers 10 so as to allow the material to cool without being altered by the support of the reinforcing fibers 10.

After passing through the die, the seal 8 passes through a cooling zone 28, for example a basin of water. The seal 8 is pulled by a driver 30 and leaves the cooling zone 28.

Finally, the seal 8 reaches a winding / cutting area. It can therefore be wound on a reel or cut into strips of desired size.

The invention is not limited to the embodiments presented and other embodiments will be apparent to those skilled in the art.

It is possible to use plastics other than an elastomeric polymer or else a silicone.

It is also conceivable to produce seals comprising areas made of different materials (by sequentially extruding different materials).

List of numerical references: bodywork part

4: main body: light source: seal: reinforcing fibers: grooves

14: protuberances: step of tensioning the reinforcing fibers: cable guide: step of conveying the reinforcing fibers in the extruder: step of supplying plastic material

24: first part of the die: second part of the die: cooling zone: driver: cutting / winding step

Claims (13)

1. Joint (8) of a bodywork part (2) of a motor vehicle, characterized in that it comprises: a matrix made of a transparent or translucent material, and - reinforcing fibers (10) extending in the matrix, the seal being elastically deformable. 2. Joint (8) according to claim 1 with a length greater than 200 millimeters, preferably equal to 2 meters. 3. Joint (8) according to any one of the preceding claims with a width of between 5 and 10 millimeters, preferably equal to 6 millimeters. 4. Joint (8) according to any one of the preceding claims, wherein the reinforcing fibers (10) extend over the entire length of the joint (8). 5. Joint (8) according to any one of the preceding claims, in which the reinforcing fibers (10) are mutually parallel in a direction parallel to a longitudinal axis of the joint (8). 6. Joint (8) according to any one of the preceding claims, in which a light source (6) is integrated in the joint (8). 7. Joint (8) according to any one of the preceding claims, in which the reinforcing fibers (10) comprise optical fibers. 8. Seal (8) according to any one of the preceding claims, in which the seal (8) is made of a material chosen from an elastomeric material or a silicone. 9. Method for manufacturing a seal (8) according to any one of the preceding claims, characterized in that it comprises the following steps: the tensioned reinforcement fibers (10) are conveyed to an extruder, the reinforcement fibers (10) are guided in the extruder by means of a cable guide (18), and the reinforcement fibers (10) are covered with plastic. 10. The method of claim 9 comprising, following the covering of the reinforcing fibers (10) with the plastic, a step of shaping the joint (8) comprising the following steps: the reinforcing fibers (10) and the plastic material pass through a first part (24) of a die, the first part placing the reinforcing fibers (10) in the plastic material, and the reinforcing fibers (10) and the plastic material pass through a second part (26) of the die, the second part conforming the material to the shape of the seal (8). 11. The method of claim 10 comprising, following the step of shaping the joint (8), the following steps: the seal passes through a cooling zone (28), and - the seal (8) is wound and / or cut. 12. Motor vehicle body part (2) characterized in that it comprises: a main body (4), - at least one slot in the main body (4), - at least one light source (6) capable of diffusing light through the slot, and at least one seal (8) according to any one of claims 1 to 8 mounted in the slot. 13. Bodywork part (2) according to the preceding claim, wherein the seal (8) comprises at least one relief (12) capable of collaborating with a relief (14) of complementary shape present on the main body (4).