FRONT AIR INTAKE OF MOTOR VEHICLE

Abstract

Front air intake of a motor vehicle (26, 28), comprising successively, in the direction of passage of the air flow made of rigid materials, an inlet having a fixing contour (30) on a bore of a sealing panel (24) of the front facade, a conduit (36) forming an elbow, and an outlet having a fixing contour (32) on a front face of a cross member (22), the conduit (36) comprising at least one thinned closed transverse contour (34) which has a reduced thickness allowing a breakage of this thinned contour (34) in the event of an impact on the air intake (26, 28). Figure 2

Description

Title of the invention: FRONT AIR INTAKE OF A MOTOR VEHICLE

[0001] The present invention relates to a front air intake of a motor vehicle, as well as a motor vehicle equipped with such air intakes.

[0002] Motor vehicles must meet standardized front impact tests on pedestrians, to limit the forces applied to the legs or the head in order to reduce injuries in the event of an accident. In particular, when a pedestrian is struck by the front of a vehicle with sufficient speed, his legs apply a horizontal force to the bumper which must be able to compress backwards, and his head can strike the front of the hood which must have sufficient flexibility to deform downwards.

[0003] A known type of motor vehicle bumper, presented in particular by document FR-A1-2980431, comprises an outer skin fixed to a shock absorber, and an air intake grille arranged in front of a part of this absorber having a reduced thickness, making it possible to obtain the flexibility necessary for impacts with pedestrians.

[0004] However, some vehicles have angled front air intakes under the hood, comprising a downward-facing inlet, fitting onto a hole in a flat, horizontal sealing frame located behind the bumper, a duct forming an angle of approximately 90°, and an outlet fixed to the vertical front face of an upper crossmember located towards the front of the vehicle's engine compartment.

[0005] The air passing through an external grille formed around the bumper, arrives under the horizontal sealing frame to supply the inlets of the air intakes fitted on this frame, then exits along a vertical section to cross the front crossmember. In particular, a flow of fresh air is formed on one side of the vehicle coming onto a heat exchanger fixed behind the crossmember to cool it, and on the other side an air inlet for supplying the heat engine.

[0006] Each air intake is usually made by an assembly of molded plastic parts, to form a rigid elbow assembly fixed at its two ends.

[0007] However, with this type of air intake, it is noted that during impacts on pedestrians, each constitutes a rigid assembly arranged just behind the bumper and under the front of the engine hood, which makes it more difficult to deform the front of the vehicle sufficiently to protect these pedestrians by absorbing the impact.

[0008] The present invention aims in particular to avoid these problems of the prior art.

[0009] To this end, it proposes a front air intake for a motor vehicle made of rigid materials, comprising successively, depending on the direction of passage of the air flow, an inlet having a contour for fixing to a bore in a front sealing panel, a conduit forming an elbow, and an outlet having a contour for fixing to a front face of a cross member, this air intake being remarkable in that the conduit comprises at least one thinned closed transverse contour which has a reduced thickness allowing this thinned contour to break in the event of an impact on the air intake.

[0010] An advantage of this front air intake is that in the event of a sufficiently significant impact on the front of the vehicle moving the bumper back or lowering the front of the hood, which transmits a force to the air intake arranged just behind, there is a possibility of breaking this intake with a sufficiently low force thanks to the reduced thickness contour, forming an initiation of rupture which can be adjusted for a predefined force.

[0011] By directly producing the closed contour of reduced thickness in the molding of the plastic conduit, effective protection of pedestrians is obtained in a simple manner, without adding any component and with a similar cost.

[0012] The front air intake of a motor vehicle according to the invention may comprise one or more of the following characteristics, which may be combined with each other.

[0013] Advantageously, the thinned contour is formed by a groove made on one face of the wall of the conduit.

[0014] In this case, advantageously the groove of the thinned contour has a depth of between one third and two thirds of the thickness of the wall.

[0015] Advantageously, the thinned contour is formed directly by molding the wall of the duct.

[0016] In particular, the air intake may comprise two thinned contours.

[0017] In this case, advantageously each thinned contour is inscribed in a plane, these planes forming between them an angle greater than 80°.

[0018] In this case, advantageously the air intake comprises a thinned contour arranged just after the inlet contour and a thinned contour just before the outlet contour.

[0019] The invention also relates to a motor vehicle equipped with front facade air intakes, connecting a substantially horizontal sealing panel to a substantially vertical crossmember front face arranged behind the sealing panel, comprising any one of the preceding characteristics.

[0020] In particular, the air intakes can provide the supply of fresh air to a heat exchanger and the air intake of a heat engine.

[0021] The invention will be better understood and other characteristics and advantages will appear more clearly on reading the description given below by way of example, with reference to the appended drawings in which:

[0022] [Fig-1] is a side view of the front of a motor vehicle receiving impacts from a pedestrian;

[0023] [Fig.2] is a front view of the engine compartment equipped with air intakes according to the invention;

[0024] [Fig.3] is a top view of this front of the engine compartment;

[0025] [Fig.4] is a longitudinal sectional view along section plane IV-IV of the socket of air supply to the thermal engine;

[0026] [Fig.5] is a detail view of [Fig.4] showing the reduced thickness outline; and

[0027] [Fig.6] shows the ruptures of this air intake in the event of pedestrian impact.

[0028] Throughout the document the expressions above, below, upper, lower, right side and left side relate to a vehicle placed on horizontal ground, looking in the forward direction of the vehicle indicated by the AV arrow.

[0029] [Fig.l] shows the front face of a vehicle equipped with a front bumper 2, a fresh air intake grille 4 formed above this bumper, and a hood 6 of the engine compartment. The entire front face of the vehicle has a general curvature to ensure the aerodynamics of the vehicle, and to avoid roughness which could injure pedestrians.

[0030] In the event of an impact on a pedestrian, the bumper 2 receiving the thrust of the legs 8 must have sufficient flexibility to compress backwards in order to reduce the stress on these legs, and the front of the hood 6 receiving the impact of the head 10 must sink downwards while also limiting the force on this head.

[0031] Figures 2, 3 and 4 show a front crossmember 20 having a vertical front face 22, and a horizontal flat sealing frame 24 arranged in front of this crossmember, at its lower level. The bumper (not shown), fixed in front of the sealing frame 24, has air inlets closed by grilles which supply fresh air to the underside of this frame when the vehicle is moving.

[0032] The front face of the vehicle has two fresh air intakes 26, 28, receiving the air under the sealing frame 24, to pass through this frame, then conduct it for each intake after a 90° bend towards a vertical outlet fixed on the front face of the cross member 22. The left air intake 26 forms the air supply to the heat engine. The right air intake 28 delivers fresh air to a heat exchanger fixed behind the cross member 20, the sealing frame 24 separating the hot air leaving the exchanger from the fresh air entering in order to avoid recycling of this hot air.

[0033] Each air intake 26, 28 successively comprises a horizontal lower contour 30 for fixing to the sealing frame 24, a conduit 36 formed by a wall of constant thickness, and a vertical upper contour 32 for fixing on the front face of crosspiece 22. The end contours 30, 32 form a rigid loop making it possible to ensure the connection with sealing and the fixing on the sealing frame 24 and the front face of facade 22.

[0034] The assembly of each air intake 26, 28 is produced by assembling several parts formed by moldings of rigid plastic material, making it possible to economically obtain complex shapes performing the various necessary functions.

[0035] In particular, the vehicle resistance standards may impose, for a force coming from the front of 30daN, a recoil of the sealing frame 24 and the left air intake 26 to the vertical plane P shown [Fig.3], substantially transverse, comprising on the side of the vehicle a slight inclination towards the rear.

[0036] Figures 4 and 5 show the fresh air intake 26 comprising downwards parallel to the inlet contour 30 at the start of the duct 36, and upwards parallel to the outlet contour 32 at the end of this duct, a thinned closed transverse contour 34. Each thinned closed contour 34 is formed by a groove made directly during molding on the outer face of the end of the duct 36, which leaves a reduced thickness of material of between one third and two thirds of the nominal thickness of the duct, in particular half of this thickness.

[0037] This method of producing the thinned contours 34 obtained directly by molding the components, without adding any additional components, does not change the manufacturing and assembly methods of the existing air intakes. In addition, this manufacturing method guarantees an absence of air leakage on the air intake 26, 28, which makes it possible to ensure the same air passage and to comply with the cooling or power supply constraints of the heat engine.

[0038] [Fig.6] shows, in the event of a front impact CA on the fresh air intake 26, or an upper impact CS, an overall mechanical stress on the duct 36 which is transmitted to the inlet contour 30 or the outlet contour 32 respectively. In the case of excessive tension on the lower or upper thinned closed contour 34, the groove of this contour produces a concentration of stresses on the thinned part, which makes it easy to break.

[0039] With the two thinned contours 34 arranged in planes forming between them an angle greater than 80°, in particular 90°, for a front impact CA on the bumper transmitted to the sealing frame 24 and to the entry contour 30, a rapid rupture of the lower thinned contour 34 is obtained, which gives more flexibility for the recoil of this bumper. Also obtained for an upper impact CS on the crossmember 20 transmitted to the exit contour 32 is a rapid rupture of the upper thinned contour 34, which gives more flexibility for the descent of this crossmember.

Claims

Claims

1. Motor vehicle front facade air intake (26, 28) made of rigid materials, comprising successively, in the direction of passage of the air flow, an inlet having a fixing contour (30) on a bore of a sealing panel (24) of the front facade, a conduit (36) forming an elbow, and an outlet having a fixing contour (32) on a front face of a cross member (22), characterized in that the conduit (36) comprises at least one thinned closed transverse contour (34) which has a reduced thickness allowing a breakage of this thinned contour (34) in the event of an impact on the air intake (26, 28), a thinned contour (34) being arranged just after the inlet contour (30) and a thinned contour (34) being arranged just before the outlet contour (32).

2. Air intake according to claim 1, characterized in that the thinned contour (34) is formed by a groove made on one face of the wall of the duct (36).

3. Air intake according to claim 2, characterized in that the groove of the thinned contour (34) has a depth of between one third and two thirds of the thickness of the wall.

4. Air intake according to any one of the preceding claims, characterized in that the thinned contour (34) is formed directly by molding the wall of the duct (36).

5. Air intake according to any one of the preceding claims, characterized in that it comprises two thinned contours (34).

6. Air intake according to claim 5, characterized in that each thinned contour (34) is inscribed in a plane, these planes forming between them an angle greater than 80°.

7. Motor vehicle equipped with front facade air intakes (26, 28), connecting a substantially horizontal sealing panel (24) to a substantially vertical crossmember front face (22) arranged behind the sealing panel (24), characterized in that these air intakes (26, 28) are according to any one of the preceding claims.

8. Motor vehicle according to claim 7, characterized in that the air intakes (26, 28) provide the supply of fresh air to a heat exchanger and the air intake of a heat engine.

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