Car bumper with ventilation grille

Abstract

The invention relates to a motor vehicle bumper comprising, on the one hand, a lower grille (1) delimited at the top by an upper wall (11) extending rearward in a plane substantially perpendicular to the grille and, on the other hand, a central cavity (10) formed in the grille (1) and intended for mounting an obstacle detection radar, characterized in that said cavity (10) opens to the outside through the upper wall (11) of the grille and is closed by a retractable flap (12), as well as a method for manufacturing such a bumper. (Figure 3)

Description

Title of the invention: Motor vehicle bumper with ventilation grille

[0001] The invention relates, in general, to the field of front bumpers of motor vehicles and, more particularly, to front bumpers comprising a ventilation grille for cooling the engine.

[0002] The invention relates more specifically to an improvement of grille bumpers whose central rear part includes a housing for mounting a radar.

[0003] Today most motor vehicles are generally equipped with a front bumper including a lower grille which has, through its front wall, openings allowing air intakes intended to cool the components mounted under the engine.

[0004] This grille must be closed off at its upper part by a wall to ensure optimal channeling of the incoming air through the lower part. In particular, to meet the cooling requirements specific to new electric motors, it is necessary to extend the upper wall of the grille along its entire length.

[0005] Furthermore, this grid includes in its rear part and preferably in a central position, a cavity for receiving an obstacle detection radar and positioning and fixing interfaces for the subsequent mounting of this radar.

[0006] However, because the bumper and its grille are manufactured using a one-piece injection molding technique, including its front and top walls, demolding the technical interfaces required for subsequent mounting of the radar at the rear of the grille is problematic. These interfaces are located in the cavity beneath the top wall of the grille, and given the industrial setup used, removing the molded bumper must necessarily be done in a direction perpendicular to this wall. Under these conditions, demolding is therefore impossible.

[0007] Therefore, the invention sought a means of demolding the bumper with its grille while preserving the radar mounting interfaces. The solution considered was to leave a space in the upper wall above the cavity to allow the mold drawer to pass through. However, this solution has the disadvantage of subsequently generating detrimental disturbances in the cooling process by creating a discontinuity in the incoming air channel.

[0008] Technical solutions exist for freeing up space in a large room on an occasional basis. For example, patent application FR2925458A3 describes an access hatch to a charging device installed in the bodywork of a motor vehicle. This hatch is mounted pivotally relative to an opening in the vehicle bodywork between a closed position, an intermediate position and an open position.

[0009] French patent FR2921624B1 describes a panel for the exterior trim of a motor vehicle comprising an access hatch for a towing device and a locking element for this hatch located on the inside of the panel. This element can be operated through the panel to allow the hatch to be opened from the outside.

[0010] However, the solutions described in these prior documents are unsuitable for the context of the invention and complex because the proposed hatches are intended to perform repeated openings and closings to regularly access functional devices or components, and not to allow a manufacturing operation by molding a bumper grille.

[0011] In this context, the invention aims to solve the technical problems posed by prior solutions and to overcome their shortcomings by proposing a bumper whose upper wall of the ventilation grid can be opened locally and temporarily to allow demolding.

[0012] This goal is achieved, according to a first aspect of the invention, by means of a front bumper of a motor vehicle comprising, on the one hand, a lower grille delimited at the top by an upper wall extending towards the rear and in a plane substantially perpendicular to the grille and, on the other hand, a central cavity formed in the grille and intended for the mounting of an obstacle detection radar, characterized in that the cavity opens to the outside through the upper wall of the grille and is closed by a retractable flap.

[0013] According to a preferred embodiment of the invention, the bumper includes a flap mounted on the upper wall by means of a hinge, said flap being movable between an opening position of the radar cavity where it extends in a plane substantially perpendicular to the grid and a closing position of said cavity where it extends in the plane of the upper wall.

[0014] Preferably, the hinge consists of a thin strip of plastic material carried by the front edge of the upper wall.

[0015] According to an advantageous feature of the bumper of the invention, the flap includes latching elements cooperating with complementary elements carried by the upper wall of the grille to lock the flap in the closed position of the radar cavity.

[0016] According to a specific embodiment, the snap-on members consist of flexible tabs extending through openings in the flap and cooperating with hooks carried by the upper wall.

[0017] According to another feature of the invention, these snap-on members are carried by the rear part of the flap.

[0018] According to a specific embodiment of the bumper of the invention, the flap is in one piece with the upper wall and the grille and includes at least one first orifice resulting from the injection of a plastic material into a mold.

[0019] According to a feature specific to this variant, the bumper includes a second injection orifice located under the cavity intended for the radar.

[0020] Another object of the invention is a method for manufacturing a motor vehicle bumper, as defined above, in one piece by injecting a plastic material into a mold, characterized in that the material is injected into the mold at two points located on an axis, corresponding, after demolding of the bumper, to a perpendicular to the upper wall of the grille and extending, on the one hand, in the plane of the flap in the open position and, on the other hand, into the bottom of the central cavity intended for the radar.

[0021] Yet another object of the invention is a motor vehicle comprising a bumper having the characteristics defined above.

[0022] Thanks to the invention, the bumper can be easily produced and extracted from the manufacturing mold implemented by a plastic injection molding process.

[0023] Since the cavity for the radar is open at the level of the upper wall, it is now possible to allow the mold drawer to pass through during the removal of the bumper along an axis perpendicular to the grille, thus preserving the positioning and fixing interfaces of the detection radar, which will be mounted during a subsequent operation.

[0024] The flap forms a hatch that closes the radar cavity upwards and extends over the top of the upper wall of the grille. This flap is retractable and is made by injection molding plastic material into a mold, either as a single piece with the upper wall and the grille, or separately and then attached and fixed to the upper wall of the grille after demolding from the bumper.

[0025] When the flap is made in one piece with the bumper, it is molded in the open position to allow the drawer to pass along the axis of the radar cavity.

[0026] This flap also allows for the positioning of an injection point in the upper part of the grid, which is judiciously placed in a central position to obtain optimal flow of the plastic material into the mold. Furthermore, the orifice resulting from the injection is invisible once the bumper is assembled onto the vehicle body.

[0027] The presence of the flap once folded down when closing the radar cavity ensures the sealing of its housing while ensuring satisfactory channeling of incoming airflows and, consequently, efficient cooling of the motor.

[0028] Other features and advantages of the invention will become apparent from the following description, with reference to the accompanying figures, for which:

[0029] [Fig-1] is a perspective view of the front of one embodiment of the bumper of the invention.

[0030] [Fig.2] is a perspective view of the rear of the bumper of [Fig.1].

[0031] [Fig.3] is a partial perspective view of the front of the bumper of figures 1 and 2 exiting the mold with the flap in the open position.

[0032] [Fig.4] is a partial perspective view of the rear of the bumper in Figures 1 and 2 exiting the mold with the flap in the open position.

[0033] [Fig.5] is a detailed perspective view of an alternative embodiment of the organs snapping of the bumper flap of the invention.

[0034] For clarity, identical or similar elements are identified by identical reference signs throughout the figures.

[0035] Naturally, the embodiments of the bumper of the invention schematically illustrated in the figures above and described below are given only by way of non-limiting examples. It is explicitly provided for in the scope of the invention that different embodiments can be proposed and combined to create others.

[0036] It is emphasized that all features, as they appear to a person skilled in the art from reading this description, the figures and the associated claims, even if in practice they have only been described in relation to other specific features, both individually and in any combinations, can be combined with other features or groups of features disclosed herein, provided that this has not been expressly excluded or that the technical context makes such combinations impossible or meaningless.

[0037] The invention relates to the general field of manufacturing bodywork components for motor vehicles and is more particularly concerned with the front bumpers of these vehicles when they are manufactured industrially using a plastic injection molding process.

[0038] Today, as illustrated by Figures 1 and 2, these front bumpers include a lower grille 1 which has openings 1b in its front wall 1a, allowing air intake. The airflow passing through this grille under the effect of the vehicle's speed is intended to cool the components mounted under the engine.

[0039] In order to optimize cooling efficiency, particularly for electric vehicles, the lower grille 1 is delimited at the top and closed off by a wall 11 which extends rearward, generally along its entire length and in a plane substantially perpendicular to the grille 1 in order to ensure forced channeling of the incoming air.

[0040] Furthermore, the grille 1 has, in its rear portion and preferably in a central and median position, a cavity 10 for receiving a radar (not shown) that detects obstacles in front. This cavity 10 is provided with positioning and fixing interfaces 13 (Figures 2 and 4) for subsequent mounting of the radar after manufacturing and, where applicable, assembly of the bumper onto the vehicle.

[0041] Traditionally, such a bumper is made from a single piece of plastic material comprising, in particular, the grille 1, the upper wall 11 and the cavity 10 with the radar interfaces 13 by injection of plastic material into a specific mold comprising several moving parts or cavities.

[0042] However, the extraction of such a bumper from the manufacturing mold is rendered impossible given the closed contours of the cavity 10 which prohibits the removal of the so-called drawer-like moving part of the mold, this removal usually taking place in a direction parallel to the plane of the grid 1 and along the axis X perpendicular to the upper wall 11 passing through the cavity 10 ([Fig.4]).

[0043] In this context and in order to overcome this obstacle while wishing to keep the radar mounting interfaces identical, the invention provides for modifying the upper wall 11 to provide an interruption at the opening of the cavity 10 so as to allow axial movement of the mold drawer during the demolding of the bumper.

[0044] However, the invention also aims to preserve the channeling of airflow entering through the grille, whereas the interruption provided in the upper wall tends to degrade the efficiency of this airflow with respect to the expected cooling of the engine. This combination of objectives is achieved according to the invention by providing a retractable flap 12 intended to close the cavity 10 after the bumper has been demolded.

[0045] In the embodiment of the bumper of the invention illustrated, in particular, by figures 3 and 4, the flap 12 is made here by injection of plastic material into a one-piece mold with the grid 1. The flap 12 is molded in the open position to allow, when removing the bumper, the passage of the drawer-shaped mold cavity along the X axis of the radar cavity 10.

[0046] The flap 12 is connected to the upper wall 12 by means of a hinge 12a molded with the other parts of the bumper. The hinge 12a is preferably made in the form of a thin strip or film of plastic material which is supported by the front edge of the upper wall 11.

[0047] This flap 12 can thus be pivoted between an open position of the radar cavity 10 (Figures 3 and 4 in solid lines) where it extends in a plane substantially perpendicular to the grid 1 which corresponds to its configuration upon exiting the mold and a closed position of the cavity 10 where it is folded down to extend and be locked in the plane of the upper wall 11, after mounting the radar on the interfaces 13 ( [Fig.3] (dotted line).

[0048] The flap 12 further comprises latching members 12b cooperating with complementary members 1a carried by the upper wall 11 of the grid 1 to lock the flap 12 in the closed position of the radar cavity 10. These latching members 12b are preferably carried by the rear part of the flap 12, as illustrated in Figures 3 and 4. According to an alternative embodiment, these latching members consist of flexible tabs 12c extending through slots 12d formed in the flap 12 and cooperating with hooks 11b carried by the upper wall 11, as illustrated in [Fig. 5].

[0049] According to a preferred embodiment of the bumper manufacturing process of the invention, a thermoplastic material is injected into a mold (not shown) at at least two distinct points. These two points are located on an axis X, which, after demolding of the bumper, corresponds to a perpendicular to the upper wall 11 of the grille 1 and extends, on the one hand, in the plane of the flap 12 in the open position and, on the other hand, into the bottom of the central cavity 10 intended for the radar.

[0050] Thus, after demolding, the bumper retains the presence of orifices resulting from the injection of the plastic material into the mold. However, these small-diameter orifices are not visible after assembly of the bumper onto the vehicle. A first orifice 12d is located on the flap 12 while a second orifice 10a is located under the cavity 10, as illustrated by [Fig. 3].

Claims

Demands

1. Front bumper of a motor vehicle comprising, on the one hand, a lower grille (1) delimited upwards by an upper wall (11) extending rearwards and in a plane substantially perpendicular to the grille and, on the other hand, a central cavity (10) formed in the grille (1) and intended for the mounting of an obstacle detection radar, characterized in that said cavity (10) opens to the outside through the upper wall (11) of the grille and is closed by a retractable flap (12).

2. Bumper according to claim 1, characterized in that said flap (12) is mounted on the upper wall (11) by means of a hinge (12a) and is movable between an opening position of the cavity (10) of the radar where it extends in a plane substantially perpendicular to the grid (1) and a closing position of said cavity where it extends in the plane of the upper wall (11).

3. Bumper according to the preceding claim, characterized in that said hinge (12a) is made up of a thin strip of plastic material carried by the front edge of the upper wall (11).

4. Bumper according to any one of the preceding claims, characterized in that said flap (12) comprises latching members (12b, 12c) cooperating with complementary members (11b) carried by the upper wall (11) of the grille to lock the flap (12) in the closed position of the cavity (10) of the radar.

5. Bumper according to the preceding claim, characterized in that the snap-on members (12b, 12c) are carried by the rear part of the flap (12).

6. Bumper according to claim 4 or 5, characterized in that said snap-on members consist of flexible tabs (12c) extending through openings (12d) formed in the flap (12) and cooperating with hooks (11b) carried by the upper wall (11).

7. Bumper according to any one of the preceding claims, characterized in that said flap (12) is of one piece with the upper wall (11) and the grille (1) and comprises at least one first orifice resulting from the injection of a plastic material into a mold.

8. Bumper according to the preceding claim, characterized in that it comprises a second injection orifice located under said cavity.

9. Method for manufacturing a motor vehicle bumper according to one of the preceding claims in one piece by injection of a plastic material into a mold, characterized in that the injection of the material into the mold is carried out at two points located on an axis (X) corresponding, after demolding of the bumper, to a perpendicular to the upper wall (11) of the grille (1) and extending, on the one hand, in the plane of the flap (12) in the open position and, on the other hand, into the bottom of the central cavity (10) intended for the radar.

10. Motor vehicle comprising a bumper according to any one of claims 1 to 8.

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