Plastic opening leaf with increased rigidity and a device for discharging a fluid

Abstract

The invention relates to an opening leaf, in particular of the tailgate type, for a vehicle, comprising a box structure made of plastic, in particular made of thermoplastic, comprising at least one fluid duct connecting at least two distinct interfacing points, each of the interfacing points being intended for the attachment of a lock, of an assistance device for the manoeuvring of the opening leaf or of a hinge for articulation of the opening leaf. The box structure comprises a device for discharging a fluid, in particular in the liquid state, out of a region inside the opening leaf that is delimited by an assembly with a covering of an external trim panel on the box structure.

Description

[0001] TITLE: Plastic opening having increased rigidity and a fluid evacuation device.

[0002] The invention relates to a plastic opening having increased rigidity and a device for discharging a fluid, as well as its manufacturing method. The technical field in which the invention falls is that of vehicles, in particular automobiles.

[0003] The use of plastic material for the manufacture of vehicle components allows the production of structural parts that can also be decorative parts. The advantage lies in the possibility offered by plastic molding to create a part that does not require a decorative trim applied in addition. The use of this manufacturing technology makes it possible to create an opening, in particular a trunk lid, in plastic material without having to add a step of assembling a trim on the structural part of the tailgate, which will subsequently be called the box. This is of significant interest when mass-producing this type of part. In addition to this economic advantage, the use of plastic material also makes it possible to lighten the opening, which promotes a reduction in the consumption of energy useful for the operation of the vehicle.Plastic molding also allows for more complex geometry, which opens up the scope for increased styling possibilities.

[0004] A tailgate-type opening must also achieve high rigidity because it is a bulky part that is subjected to significant forces, particularly located at the fixing points of the maneuvering assistance means, which are located approximately in the middle part of the opening. Such assistance means may be hydraulic cylinders or electromechanical mechanisms. Another area of ​​the opening subject to high mechanical stress is located at the lock, in the lower part of the opening, which must absorb slamming forces allowing the opening to be locked to the body on which it is hinged while concomitantly opposing the compression forces of at least one sealing element arranged on the periphery of the rear opening of the body which is intended to be closed by the opening.At the top of the opening there are joints which allow the opening to move on the body.

[0005] It is therefore customary to resort to the creation of a rigidity beam, also called a hollow vein or a fluid vein due to its creation by injecting air and / or water during the molding phase of the thermoplastic material. Such a beam aims in particular to connect each of the areas with high mechanical stresses such as those mentioned above. However, this solution has drawbacks. Cases of water retention near the vein have been noted, particularly near the lock. Due to the manufacturing constraints of the tailgate in thermoplastic material, particularly those linked to the demolding of the box, the interface wall through which the lock is mounted creates with the fluid vein a water retention zone inside a dry zone of the box.

[0006] The aim of the invention is to provide a device and method for manufacturing this device which overcomes the above drawbacks and improves the quality of the openings known from the prior art.

[0007] To this end, the invention relates to an opening, in particular of the tailgate type, for a vehicle, comprising a box made of plastic material, in particular of thermoplastic material, comprising at least one fluid vein connecting at least two separate interface points, each of the interface points being intended for the fixing of a lock, a device for assisting the operation of the opening or a hinge for articulating the opening.

[0008] The box comprises a device for discharging a fluid, in particular in the liquid state, from an area inside the opening which is delimited by an overlapping assembly of an exterior appearance panel on said box.

[0009] According to the invention, the aforementioned opening may comprise the following characteristics taken separately or in combination with each other:

[0010] - the evacuation device is located at the level of the fluid vein, which is of closed section despite the presence of the evacuation device;

[0011] - the drainage device is at least a localized reduction in the section of the fluid vein forming a drainage channel between the fluid vein and the exterior appearance panel;

[0012] - the evacuation device extends between a retention zone located in the upper part of the fluid vein and an evacuation zone located in the lower part of the opening, in particular between the fluid vein and a lower end edge, the retention zones and an evacuation zone being a fluidic relationship via the evacuation device;

[0013] - the retention zone is delimited by an interface wall located in the lower part of the opening, said interface wall being capable of cooperating with a lock, in particular by partly forming a means of fixing a lock, said interface wall extending in a transverse plane inclined relative to the longitudinal axis;

[0014] - the retention zone is delimited by at least one stiffening rib forming a connecting bridge between the interface wall and a bottom wall of the box extending the interface wall, the interface and bottom walls running in separate transverse planes that intersect with each other, the stiffening rib extending longitudinally to the opening and perpendicular to said interface and bottom walls;

[0015] - the at least one stiffening rib surrounds at least one lateral or transverse edge of the lock;

[0016] - the interfacing wall and the stiffening rib are connected to each other by the fluid vein.

[0017] The invention also relates to a vehicle, in particular of the automobile type, which comprises an opening having at least one of the preceding characteristics.

[0018] The invention also relates to a method of manufacturing an opening described previously or a vehicle described above, according to which the evacuation device is produced:

[0019] - concomitantly with the molding of the thermoplastic box of the opening, so that the fluid vein locally presents an evolving section of an external wall forming a drainage channel or

[0020] - by a separate step subsequent to the molding of the box, consisting of crushing the fluid vein by a heating element, in particular by a sonotrode or by an electrical resistance, in order to locally deform the external wall of the fluid vein to create a drainage channel.

[0021] The attached drawings represent, by way of example, in a non-limiting manner, an embodiment of an opening according to the invention.

[0022] Figure 1 represents an opening of a motor vehicle.

[0023] Figure 2 represents a sectional view of axis II-II of the opening of Figure 1

[0024] Figure 3 represents, according to an enlargement of Figure 1, the opening highlighting the fluid evacuation path created at the level of a structural element of the opening,

[0025] Figure 4 shows an enlarged version of an alternative embodiment of the opening comprising a fluid evacuation device. Figure 5 shows an alternative embodiment of the evacuation device.

[0026] We will refer to a direct orthonormal XYZ reference frame usually used in automotive design, in which the X axis designates the front-rear longitudinal direction of the vehicle, oriented towards the rear, the Y axis designates the transverse direction of the vehicle and is oriented from the left to the right of the vehicle, left and right being defined according to the point of view of a driver of the vehicle, the Z axis designates the vertical direction, and is oriented upwards, the vehicle resting on horizontal ground.

[0027] The term "interior" means the side closest to the inside of the passenger compartment of the vehicle. Similarly, the term "exterior" means the side opposite the inside of the passenger compartment, i.e., the side closest to an environment outside the vehicle. Finally, the term "lower" means the side closest to the ground on which the vehicle rests or the lowest, and the term "upper" means the side furthest from the ground or the highest. The vehicle 2 comprises an opening 1 of the type of a rear hatch which comprises a structural element, hereinafter called box 3, which is made of plastic. As a plastic material, it is a thermoplastic which, unlike a fiber-filled composite material, for example fiberglass, requires special stiffening. This is why the tailgate is made by injecting an air-type fluid to create at least one stiffening beam, also called a fluid vein 4.The resistance to deformation of the opening 1 is partly achieved by the fluid stream 4 on which the force-generating elements are arranged. By force-generating element is meant the articulation hinges of the opening, the maneuvering assistance devices and the lock. In Figure 1 representing the opening 1 in the closed position, the interface points P1 are intended for the assembly of the maneuvering assistance device, the interface points P2 are intended for the assembly of the articulation hinges, the interface point P3 is intended for the fixing of a lock.

[0028] By means of the articulation hinges, the opening 1 is articulated near a rear roof crossmember, around an axis Y. To do this, the opening 1 of figure 1 comprises interface points P2 located in its upper part which are spaced from each other relative to a transverse axis so that they are arranged symmetrically relative to a median plane of axis XZ.

[0029] By means of the interface points P3, the opening 1 receives maneuvering assistance devices which accompany at least the lifting of the opening from its closed position to its open position, and which maintain the latter in the open position. The assistance devices can be mechanical in nature, as is the case with balancers, or electrical such as jacks making the opening and closing automatic. Such assistance devices connect the rear ring of the vehicle body to lateral edges of the opening, here to the left and right lateral edges, below a central opening 20 formed through the box. This opening 20 is delimited by an inner edge of the box against which a rear window is intended to rest.

[0030] By means of the interface point P2, the opening 1 is able to receive a lock positioned in the lower and central part of the opening.

[0031] The complex geometry of the box 3 is appreciated in Figure 2, in which the lower part of the box 3 is represented according to a cross-sectional view of the plane of axis XZ. The lower part of the box 3 is the part located under the opening 20. The inner edge of the opening 20 can receive a frame 21 which is shaped according to the geometry of the opening 20, in order to stiffen the box 3 weakened by the presence of the opening. The lower part of the box 3 is covered by an exterior panel 7 of appearance which can be made of plastic material. The positioning of the exterior panel 7 on the box 3 delimits an interior zone 6 of the opening. The box 3 comprises a bottom wall 13 which is the vertical extension of the interface wall 11 intended to receive the lock.The geometry of the interface wall 11 is defined according to the dimension of the opening, its opening kinematics and the geometry of the body and the position of the bolt on the rear body ring.

[0032] The depth of the box 3 is partly defined by the geometry of the interfacing wall 11 of the lock. The bottom wall 13 forms a substantially obtuse angle with the interfacing wall 11.

[0033] The lower zone of the bottom wall 3 comprises a lower end edge 10 comprising means for fixing the outer panel 7, which may be formed of interfaces 17 intended to receive assembly clips. The lower end edge 10 comprises water drainage holes distributed along the edge, in particular in a regular manner so that the spacing between two drainage holes 18 is substantially constant.

[0034] The fluid vein 4 may be substantially U-shaped in order to connect at least two distinct interface points P1, P2 and / or P3 together. According to the illustrated embodiment, all of the interface points are connected together by the fluid vein 4, in the sense that the interface points are arranged in the immediate vicinity of the fluid vein 4, directly or by means of dedicated reinforcing elements.

[0035] In Figure 2, the bottom wall 13 comprises two portions connected by the interface wall 11 which extends substantially horizontally over part of the width of the box. The portions of the bottom wall 13 extend substantially vertically.

[0036] The fluid vein 4 is located in the lower part at the junction between a portion of the bottom wall 13 and the interfacing wall 11, as can be seen in FIG. 2. The upper part of the fluid vein 4 extends above the interfacing wall 11, which creates a water retention zone Z1 shown in FIG. 1 and located in FIG. 2.

[0037] The effects of condensation can cause water to stagnate in the retention zone Z1, which depending on the outside temperature can freeze and thus create a solid which, when it comes off the box, moves noisily inside the interior zone 6 of the opening. In order to evacuate the water from the retention zone Z1, the box 3 comprises a device 5 for evacuating a fluid from the interior zone 6 so that the fluid can follow the evacuation path F1 as illustrated in phantom in Figure 3 and Figure 4.

[0038] Fluid vein 4 includes the F1 discharge path.

[0039] The fluid vein 4 comprises a drainage channel 51 made on the wall of the stiffening beam formed by the fluid vein.

[0040] The fluid vein 4 comprises upper, lower, front and rear walls so as to form a closed hollow section beam.

[0041] The drainage channel 51 preferably extends transversely to the fluid vein 4 in that it has a substantially rectilinear profile of axis X. At the drainage channel 51, the fluid vein 4 is maintained in a closed section such that there can be no flow inside the closed hollow section. Even though the fluid vein 4 may have an outer wall of cross-section that is substantially parallelepipedal, with the aforementioned wall portions, the inner wall of the fluid vein may be of substantially circular section. The production of the drainage channel 51 aims to locally deform at least two adjacent portions of the fluid vein 4, in particular the upper and rear portions. In this way, in a localized manner, the fluid vein 4 comprises an inclined portion connected to the bottom and lower portions.

[0042] According to the embodiment of FIG. 4, the drainage channel 51 has a width of between 5 and 10 mm.

[0043] The box 3 comprises at least one drainage channel 51 located at the lowest foot of the retention zone Z1. The drainage channel 51 may be located near the stiffening rib 12. In FIG. 4, the stiffening rib 12 is parallel to the drainage channel 51 in the sense that the linear profile of the drainage channel 51 extends along an axis common to that in which the stiffening rib 12 is inscribed, which extends substantially in a plane of axis X in particular.

[0044] Preferably, the deformed portion forming the drainage channel 51 is produced by thermal deformation under mechanical stress.

[0045] The method of manufacturing the drainage channel 51 may include a step of using a sonotrode, i.e. an ultrasonic energy director. These ultrasounds come from a generator, and are transmitted to this energy director which, by micro-vibrations, will heat the plastic material. The thrust force which is exerted by the sonotrode on the part then crushes portions of the vein.

[0046] According to another type of conceivable method, it could be envisaged to use a heating blade whose heat comes from an electrical resistance. Thus applied to the fluid vein 4, the portions of the wall of the fluid vein 4 deform due to their contact with the heating blade.

[0047] Whatever the manufacturing process chosen, the deformation operation is carried out after the molding operation of the box 3 during which the fluid vein 4 is produced by a step of injecting a fluid containing in particular pressurized air into the mold in order to deform the material.

[0048] According to the embodiment of Figure 5, the profile of the drainage channel 51 is scalable along the Y axis. The production of such a profile can be carried out by a displacement of the means used for thermal deformation, along the fluid vein 4. Such a profile with an evolutive section of the drainage channel 51 can also be produced simultaneously with the production of the fluid vein 4, by injection of a fluid under pressure. In this case, the mold must be adapted to this evolutive shape to be created at the level of the stiffening beam formed by the fluid vein 4.

[0049] Given that the production of the drainage channel 51 occurs after the manufacture of the thermoplastic box, it may be envisaged to produce the drainage channel 51 at the level of the vehicle's after-sales network, when a vehicle equipped with a plastic tailgate is presented.

[0050] The drainage channel 51 allows a fluid connection between the retention zones Z1 and the evacuation zones Z2 so that any fluid in the liquid state can be evacuated from the box 3.

[0051] The evacuation zone Z2 is delimited by the lower end edge 10 of the bottom wall 13 of the box 3. The lower end edge 10 comprises through holes 18 which are located close to the interfaces 17 dedicated to fixing the outer panel 7 on the box 3. The lower end edge 10 on which at least one through hole 18 is provided extends in an approximately horizontal plane of axis Y, which allows evacuation by gravity.

[0052] In the event that the design of the box 3 reveals several retention zones Z1, the fluid vein 4 can comprise as many evacuation devices 5 as there are retention zones.

[0053] The opening of the invention is remarkable in that it is made of plastic, in particular with regard to its box, which makes it easy to produce in large series. Because the plastic is not loaded with reinforcement, for example fiberglass, the box 3 made of thermoplastic material is stiffened by the presence of at least one beam formed by a fluid vein resulting from a process of injecting a pressurized fluid, in particular air. The fact of locally creating an evacuation device 5 at the level of the wall of the fluid vein without piercing the latter, perpetuates the resistance to deformation of the tailgate, while creating a solution that does not allow water to stagnate, and therefore potentially freeze inside the tailgate, depending on cold climatic conditions.

Claims

CLAIMS 1. Opening (1), in particular of the tailgate type, for a vehicle (2), comprising a box (3) made of plastic material, in particular of thermoplastic material, comprising at least one fluid vein (4) connecting at least two separate interface points (P1, P2, P3), each of the interface points being intended for the fixing of a lock, a device for assisting in the operation of the opening or a hinge for articulating the opening, characterized in that the box (3) comprises a device for discharging (5) a fluid, in particular in the liquid state, from an interior zone (6) of the opening which is delimited by an overlapping assembly of an exterior panel (7) of appearance on said box (3).

2. Opening (1) according to the preceding claim, characterized in that the evacuation device (5) is located at the level of the fluid vein (4), which is of closed section despite the presence of the evacuation device (5).

3. Opening (1) according to any one of the preceding claims, characterized in that the evacuation device (5) is at least a localized reduction in the section of the fluid vein (4) forming a drainage channel (51) between the fluid vein and the exterior appearance panel (7).

4. Opening (1) according to any one of the preceding claims, characterized in that the evacuation device (5) extends between a retention zone (Z1) located in the upper part of the fluid vein (4) and an evacuation zone (Z2) located in the lower part of the opening, in particular between the fluid vein (4) and a lower end edge (10), the retention zones (Z1) and an evacuation zone (Z2) being a fluidic relationship via the evacuation device.

5. Opening (1) according to the preceding claim, characterized in that the retention zone (Z1) is delimited by an interface wall (11) located in the lower part of the opening, said interface wall being capable of cooperating with a lock, in particular by partly forming a means of fixing a lock, said interface wall extending in a transverse plane inclined relative to the longitudinal axis (X).

6. Opening (1) according to the preceding claim, characterized in that the retention zone (Z1) is delimited by at least one stiffening rib (12) forming a connecting bridge between the interface wall (11) and a bottom wall (13) of the box extending the interface wall, the interface and bottom walls evolving in separate transverse planes intersecting with each other, the stiffening rib (12) extending longitudinally to the opening and perpendicularly to said interface (11) and bottom (13) walls.

7. Opening (1) according to the preceding claim, characterized in that the at least one stiffening rib (12) surrounds at least one lateral or transverse edge of the lock.

8. Opening (1) according to any one of the preceding claims in combination with claims 5 and 6, characterized in that the interfacing wall (11) and the stiffening rib (12) are connected to each other by the fluid vein (4).

9. Vehicle (2), in particular of the automobile type, characterized in that it comprises an opening (1) according to any one of the preceding claims.

10. Method of manufacturing an opening (1) according to any one of claims 1 to 8, or a vehicle (2) according to claim 9, characterized in that the evacuation device (5) is produced: - concomitantly with the molding of the box (3) in thermoplastic material of the opening, such that the fluid vein (4) locally has an evolving section of an external wall (41) forming a drainage channel (51) or - by a separate step subsequent to the molding of the box (3), consisting of crushing the fluid stream (4) by a heating element, in particular by a sonotrode or by a resistor electrically, in order to locally deform the outer wall (41) of the fluid vein (4) to create a drainage channel (51).

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