COOLING DEVICE FOR AN ENGINE AREA OF A VEHICLE, AND ENGINE HOOD EQUIPPED WITH SUCH A DEVICE

Description

Technical field of the invention

[0001] The invention relates to a cooling device for a vehicle's engine compartment and a hood incorporating such a device. The invention is relevant to vehicles where adequate ventilation is essential for removing heat from the engine compartment. Prior art

[0002] Motor vehicles, and especially sports cars, generally include an engine compartment requiring specific ventilation to dissipate heat, particularly when stationary after driving. Given the very nature of these vehicles, there is a constant quest for weight reduction necessary for performance. To achieve this, composite materials, particularly carbon fiber, are sometimes used in the manufacture of body components, such as the engine compartment cover. The thermal stresses generated by such materials necessitate ventilation to prevent overheating when the vehicle is stationary. Creating ventilation openings directly at the top of the hood allows for heat dissipation but has the drawback of creating a risk of water leakage in case of rain.

[0003] Document FR 2 661 139 A1 discloses a single air intake opening, a water collection box, and drain pipes. This document discloses the preamble to claim 1. Presentation of the invention

[0004] The object of the invention is to provide an engine compartment cooling device that improves upon the situation known in the prior art, in that it simultaneously allows the heat to be removed from the engine while protecting the engine compartment from any water ingress in case of rain, particularly when the vehicle is stationary.

[0005] The object of the invention is a cooling device, particularly for convection cooling, for the engine compartment of a vehicle, comprising at least one airflow passage, in particular for hot air from the engine, said passage being partially formed by an opening through a hood covering the engine compartment, each opening being formed by at least one external opening through the outer skin of the hood and at least one internal opening through the hood lining, the external opening extending in a plane approximately perpendicular to the plane of the internal opening. Such a design makes it possible to create a hot air flow path incorporating a baffle that acts as a barrier to water ingress.

[0006] According to the invention: The passage is achieved through a central opening extending transversely; this allows the flow of hot air emanating from the central part of the engine compartment to dissipate outside the vehicle. Given that the central part of the engine compartment is sometimes subjected to high temperatures due to its close proximity to the powertrain, such an opening allows the heat emitted by the engine to be evacuated when the vehicle is stationary; the central opening includes an external opening separated from an internal opening by a central water collector; this allows rainwater to be collected to prevent it from spreading into the engine compartment; the passage is achieved through at least one lateral opening extending longitudinally; this allows the intake and evacuation of a flow of hot air emanating from at least one lateral part of the engine located directly above the opening.

[0007] According to another aspect of the device of the invention: It includes a protective grille, in particular a metal grille, extending at the level of the opening; such a metal grille is a perforated wall which filters the air that may flow through the opening when the vehicle is in driving mode, while creating a barrier to the airflow in the dynamic state of vehicle movement to reduce the amount of air entering the engine compartment and reduce the aerodynamic drag of the moving vehicle.

[0008] According to the invention: The side opening includes an external opening separated from an internal opening by a lateral water collector; this allows rainwater to be collected to prevent it from spreading into the engine compartment, particularly at the side parts of the engine; the central or lateral water collector is of the type of a collection box delimited by a bottom wall bordered by a peripheral wall of the hood lining, the water collector includes at least one gutter, in particular with a substantially longitudinal orientation, intended for the flow of the collected water towards the outside of the engine compartment;

[0009] According to another aspect of the device of the invention: The front end of the gutter includes at least one drainage hole, located in particular at a front peripheral edge of the hood; the side opening is connected to a side gutter, and the central opening is connected to at least one central gutter, the side gutter emptying into the central gutter; this allows for a cascading collection of the water flow to be evacuated, the advantage of which is to reduce the number of gutters to be used; the gutter has a substantially U-shaped cross-section and a substantially linear profile with a substantially longitudinal orientation; this allows it to follow the curved profile of the engine compartment closing hood as it slopes towards the front of the vehicle; the peripheral wall includes at least one internal opening, in particular internal openings distributed partly along a lateral or transverse portion;This allows for the sharing of functions so that the water collection box communicates with the engine compartment to also carry out the evacuation of heat by convection from a circulation of a flow of hot air from the engine to the outside of the vehicle; the peripheral wall is inclined with respect to the vertical axis so that the surface area of ​​the opening is increased; this allows the collection box to be installed despite the proximity of the engine to the hood lining; the bottom wall of the lateral water collector is substantially flat and inclined inwards with respect to a horizontal plane at an angle between 5° and 15°, in particular at an angle of about 9°, the bottom wall comprising a variable depth to which the gutter is directly in fluidic relationship;This advantageously eliminates the risk of water pooling, for example, when the vehicle is parked on one side of a sidewalk, and ensures drainage of the water collected by the collection box; the water collector includes a transverse gutter connected to the front end of the longitudinal gutter, the transverse gutter including at least one drainage hole; this allows for an increase in the number of holes made in the gutters for the drainage of the collected water.

[0010] The invention also relates to a hood, in particular for closing a vehicle engine compartment, characterized in that it includes a cooling device having any of the aforementioned characteristics.

[0011] The hood can be made by a molding operation of at least one composite material, in particular consisting of a resin containing at least one glass and / or carbon fiber, the fiber having different densities depending on the part of the hood to be molded.

[0012] The hood may include a central passage and lateral passages for the flow of air, the lateral passages being symmetrically distributed on either side of the central passage, which allows for a homogeneous collection of the hot air flow under the hood and therefore better heat dissipation.

[0013] The hood may include a side water collector attached to the liner, allowing the hood liner to be designed separately from the water collection box, thus offering the possibility of using different materials. In another embodiment, the hood may include a side water collector formed by molding the liner.

[0014] The hood skin can be made with two identical layers of fiberglass, while a central part of the skin containing the central opening can be made with two different layers, one of fiberglass and the other of carbon fiber.

[0015] The hood lining can be made with two layers of carbon fiber, the layers being of different densities, which allows for easy optimization of the hood's strength by selecting the appropriate carbon fiber density according to the predetermined deformation resistance target. The invention also relates to a vehicle, in particular an automobile, comprising a hood having any of the aforementioned characteristics. Presentation of the figures

[0016] The objects, features and advantages of the present invention will be described in detail in the following description of a particular embodiment, given by way of non-limiting example, with reference to the accompanying figures, among which: [ FIG. 1 ] There figure 1 is a schematic perspective view of a hood covering an engine compartment of a vehicle comprising a cooling device according to an embodiment of the invention, consisting of ventilation openings. FIG. 2 ] There figure 2 is a bottom view of a hood liner comprising a cooling device provided with a means for collecting and draining water collected through openings, according to the invention. FIG. 3 ] There figure 3 is a schematic perspective view of an engine compartment cover seen from above, showing the outer skin according to the figure 1 represented in transparency and the lining according to the figure 2"on which are represented the cutting lines AA and BB. FIG. 4 ] There figure 4 is a cross-sectional AA view of the hood of the figure 3 . [ FIG. 5 ] There figure 4 is a cross-sectional AA view of the hood of the figure 3 . [ FIG. 6 ] There figure 6 is a perspective representation of an enlarged view of the hood lining from above to illustrate an embodiment of the water collection box through which a flow of hot air is able to circulate in order to evacuate heat to the outside of the hood. Detailed description

[0017] In this document, the X-axis represents the longitudinal axis of a vehicle. When moving forward in a straight line, the vehicle progresses from rear to front in a direction parallel to its longitudinal axis. The X-axis is oriented from the front to the rear of the vehicle, that is, in the direction of reverse. The Y-axis represents the transverse axis of the vehicle. The Y-axis is oriented from left to right, with left and right defined from the perspective of a driver of the vehicle. The Z-axis is perpendicular to the X-axis and the Y-axis. The Z-axis is vertical when the vehicle is on a horizontal surface. The Z-axis is oriented from bottom to top. The X, Y, and Z axes form an orthogonal coordinate system. This same coordinate system, defined with reference to a vehicle, will also be used for a cooling device, since it is mounted in a specific orientation on a vehicle. Furthermore, the vehicle is assumed to be on a horizontal surface.

[0018] There figure 1 This schematically illustrates a hood equipped with a cooling device according to an embodiment of the invention. The vehicle can be of any type. In particular, it can be, for example, a passenger car, a commercial vehicle, a truck, or a bus. Specifically, the vehicle is a sports vehicle in that it is designed with lightweight materials and is equipped with a high-performance engine. Due to its high performance, the components of such a vehicle must withstand high temperatures or at least be equipped with cooling devices that reduce the impact of heat on the mechanical strength of the components.

[0019] On the figure 1The hood 2 includes a cooling device 1, characterized by the presence of a passage 3 for the flow of air resulting from convective heat exchange. This heat exchange could be forced by the use of a suitable means such as a fan. On the figure 1 The hood 2 comprises three openings 3, specifically a central opening 33 symmetrically spaced by lateral openings 31, 32. As shown, the central opening 33 extends along the Y-axis. The lateral openings 31, 32 extend along the X-axis in a particular arrangement whereby the rear portion of the lateral openings 31, 32 is positioned at the level of the central opening 33. figure 1representing the outer skin 6 of the hood 2 through which the flow of hot air represented by arrows CL and CC escapes from the engine compartment intended to be closed by the hood 2. Rainwater is represented by arrows EL and EC falling on the outer face of the hood; it flows through openings 31, 32, and 33. Openings 31, 32, and 33 respectively comprise an external opening 311, 321, and 331 formed on the outer skin 6, as shown in the figure 1 and an internal opening 312, 322, 332 made in the hood lining 7 as is made visible at the figure 2 .

[0020] The external openings 311, 321, 331 are arranged in a plane that extends substantially perpendicularly to the plane of the internal openings 312, 322, 332, creating a baffle that allows for the separation of water contained in the air when the vehicle is in motion, the collection of rainwater, and the evacuation of heat under the engine hood when the vehicle is stationary. On the figure 2 The cooling device 1 includes at least one collection box 20 which is suitable for collecting water and allowing an airflow to circulate out of the hood. The hood lining 7 includes a left collection box 21 and a right collection box 22 which are attached to the underside of the lining 7. The left collection box 21 or right collection box 22 can be fixed by riveting. Alternatively, it can be fixed by bonding with a bead of adhesive 326, as shown in the figure 5 .

[0021] The lining 7 is shaped to drain the collected water by at least one collection box 21, 22 or by a water collector 314, 324, 334 coming either from the material of the collection box or directly from the hood lining 7. figure 4 represents in cross-section the central opening 33 made by the superposition of the outer skin 6 and the hood lining 7 comprising respectively an external opening 331 and an internal opening 332. The water collector 334 is substantially linear, extending parallel to the Y axis.

[0022] A grille 323, 333 is positioned at the external opening 311, 321, 331 in order to filter the air that may flow through the opening 31, 32, 33 from the outside to the inside of the engine compartment.

[0023] The assembly of grid 323, 333 can be obtained by molding as will be seen in more detail later.

[0024] Each water collector 314, 324, 334 is connected to a gutter 317, 327, 337 which can be directly molded with the hood lining 7 according to a preferred embodiment of the invention.

[0025] Lining 7 includes gutters 317, 327 connected to collectors 314, 324 or water boxes 21, 22, they will be referred to hereafter as side gutters.

[0026] The central water collector 334 is connected to a gutter 337 which is designed to ensure a flow of the collected water towards a peripheral edge of the hood 2.

[0027] On the figure 2Each end of the central water collector 334 is connected to a gutter 337 which extends at a slight angle outwards and towards the front 4 of the hood. The gutter 337 is positioned between the collection boxes 21 and 22. Their angle allows it to bypass a central portion of the hood which includes the locking device 8, comprising in particular a strike wire carried by the hood, as can be seen in figure 2 .

[0028] These gutters 317, 327 connected to collector 334 will be referred to hereafter as central gutters.

[0029] Water collectors 314 and 324 are respectively connected to a gutter 317 and 327. A front portion of the collection box 21 and 22 includes a notch for connecting to the gutter 317 and 327 to create a water drainage path. The gutters 317 and 327 are designed to ensure water flow, specifically gravity flow via the downward curve of the cover, to discharge the collected water towards a peripheral edge of the cover 2. The lateral gutter 317 and 327 join the central gutter 337 to partially merge and form a single, continuous water drainage channel towards the outside of the cover. This is why, symmetrically with respect to a median plane of axes XZ, the hood 2 includes, at each of the left and right sides, a lateral gutter 327 opening into a gutter 337. The junction thus presents a profile substantially in V.

[0030] The front end of each gutter 337 includes at least one opening 347 of the type of a through hole in the bottom of the gutter with a cross-section substantially in U shape.

[0031] The gutter 337 communicates with a transverse gutter 357 which also includes an opening 367. The end of the gutter 337 located at the front part 4 of the hood extends towards the inside of the hood by a transverse gutter 357. This ensures that, in the event of the vehicle being parked on an incline, for example due to partial parking on a sidewalk on one side, water will be evacuated even if it were to bypass the opening 347 at the end of the gutter 337.

[0032] The central or lateral water collector 314, 324, 334 is in the embodiment of the figure 6 , of the type of a collection box delimited by a bottom wall 71 bordered by a peripheral wall 72 of substantially rectangular profile.

[0033] The side collectors 314 and 324 are, apart from symmetry, substantially identical so that in what follows, only one of the side collectors will be described in detail knowing that the other collector contains the same characteristics.

[0034] The peripheral wall 72 may thus comprise inner and outer lateral portions connected by front and rear transverse portions. The bottom wall 71 is preferably flat.

[0035] The bottom wall 71 is preferably inclined towards the inside of the hood 2 at an angle α between 5° and 15°, or more particularly at an angle of about 9°.

[0036] The bottom wall 71 is preferably inclined towards the front of the hood 2.

[0037] The peripheral wall 72 includes a recess for connection to the lateral gutter 317, 327 which, according to the embodiment, extends to the continuation of the inner lateral portion of the peripheral wall, as can be seen on the figure 6 Due to the inclination of the bottom wall 71, the height of the collection box 21, 22 is greater on the side of the inner lateral portion at the level of which the lateral gutter 317 is in fluidic relation due to a notch made in the front lateral portion.

[0038] The peripheral wall 72 includes at least one portion with internal openings 312, 322. Preferably, the inner lateral portion and a rear transverse portion include internal openings 312, 322. To increase the area of ​​the internal openings 312, 322, the peripheral wall can be inclined at an angle β with respect to a plane with axis Z between 10° and 30°, or more particularly at an angle of about 18°.

[0039] For example, due to the aforementioned inclinations, the internal lateral and rear transverse portions have a substantially rectangular, specifically trapezoidal, cross-section. The internal lateral portion preferably comprises two internal openings 322, each with a surface area between 10 and 20 cm², for example, 12 cm² and 14 cm² respectively. The rear transverse portion preferably comprises one internal opening 322 with a surface area between 5 and 10 cm², preferably 6.5 cm², as can be seen on the figure 6 .

[0040] The central collector 334 is visible at the figure 4 according to an AA cut of the figure 3 .

[0041] The collector 334 comprises a bottom wall 71 extended at the rear by a peripheral wall 72. The bottom wall 71 and peripheral wall 72 are substantially linear so that they define a water collection gutter. The internal opening 332 is located at the rear of the gutter. Due to this staggered design, the hot air flow CC circulating through the opening 3 follows a substantially S-shaped direction, in that the airflow circulates from bottom to top, contained within the buffer zone located behind the grille 333, and then exits forward through the grille 333 to reach the external environment.

[0042] The side opening 31, 32 or central opening 33 includes a protective grille 323, 333. The protective grille 323 of the side opening 321 is substantially parallel to the outer skin 6 covering the hood lining 7 by overlapping, as can be seen in particular in figure 5 .

[0043] The grille 333 of the central opening 331 is substantially perpendicular to the outer skin 6 covering the hood lining 7 by overlapping, as can be seen in particular in figure 4 .

[0044] The grid is a perforated wall that has a substantially flat profile.

[0045] The protective grille 323 of the side opening 321 can be attached to the outer skin 6 by molding. According to an alternative embodiment, the protective grille 323 is interposed between the left collector box 21 or right collector box 22 and the hood lining 7.

[0046] The protective grille 333 of the central opening 331 can be fixed by screwing it to the hood lining 7, as can be seen on the figure 4It can be joined to the outer skin 6 by molding or overmolding. According to one embodiment, the protective grille 33 can be attached to the collection box by bonding before the latter is fitted against the outer skin 6. According to another embodiment, the protective grille is attached by riveting and / or screwing to the hood lining 7.

[0047] The manufacturing process for hood 2 will now be detailed.

[0048] The lateral opening 31, 32 includes a series of connecting bridges 325 distributed homogeneously in the opening such that the X gap between two bridges 325 is substantially equal to the X gap between an end bridge and a front or rear transverse edge of the opening.

[0049] The 325 connecting bridges are parallel to each other, linking the left and right lateral edges of the opening.

[0050] On the figure 5, each bridge 325 extends along the Y axis. Each connecting bridge 325 has approximately a linear profile of curved section, notably convex with respect to the outer face of the hood, which tends to improve the airflow in dynamics.

[0051] Advantageously, the protective grid 323 rests against the underside of the bridges 325, which tends to improve the rigidity of the grid due to at least partial overlap, in order to protect the grid against any intrusion of projectiles coming in particular from the outside.

[0052] The hood including the previously detailed cooling device is preferably made by molding at least one composite material.

[0053] The hood is made by a molding operation of at least one composite material.

[0054] The composite may include a resin as well as at least one woven layer which is composed of fiberglass and / or carbon fiber.

[0055] By using one or more woven layers of different fiber types, it is possible to achieve different densities in the various parts of the hood, and therefore varying degrees of resistance to deformation. The woven layer can thus have a first, second, or third density. The first density can be higher than the second density, and the second density can be higher than the third density. For example, the first density can be achieved with a layer of fiberglass, while the second and third densities can be achieved with fibers made from carbon fiber. For example, the first density could be approximately 700 g / mm², the second approximately 630 g / mm², and the third approximately 200 g / mm².

[0056] The central area housing the locking mechanism, as well as the rear areas for attaching the hood hinges, may have greater rigidity than the rest of the hood. The hood liner 7 may therefore locally include areas of increased rigidity made of two woven carbon fiber plies of the second density and one woven carbon fiber plies of the third density.

[0057] The remainder of the hood lining 2 may include an assembly by layering woven sheets having the second and third densities respectively.

[0058] The hood lining 7 includes the collector boxes 21, 22 which can be produced during the same molding operation.

[0059] According to one alternative embodiment, the collection boxes 21, 22 are made independently of the lining 7 of the hood 2. The collection boxes 21, 22 can be made of plastic, then fixed by gluing to the hood 2, in particular under the lining 7.

[0060] Prior to the placement of the woven sheets in the mold, the grids 313, 323 are positioned in the mold.

[0061] The outer skin 6 of the hood is also made by molding a composite material, for example according to two woven sheets having the first density.

[0062] According to one embodiment, the central part of the outer skin 6 in which the central opening 33 is made is made of two different woven layers, one having the second density, the other the third density.

[0063] Given that the external opening 331 is substantially vertical, the outer skin 6 includes a recess 9 with a variable height. This recess 9 forms an air scoop with a variable cross-section. The profile of the recess 9 has two variable components in Y and Z, in the sense that along the X-axis: The recess profile 9 evolves from a front edge flush with the adjacent area of ​​the outer skin 6 to a rear edge that projects, locally creating a Z-shaped step as can be seen on the figure 4 , and that the Y-shaped gap between the lateral edges of the recess 9 increases from front to back as can be seen on the figure 1 .

[0064] The Z-depth of the rear portion of the recess 9 corresponds approximately to the height of the outer opening 331 of the central opening 33. The outer skin 6 is bonded to the lining 7 by a bead 10 of adhesive which extends partly along a peripheral rib 11 forming a continuous assembly ring. The outer skin 6 is bonded to the lining 7 by strands of adhesive bead 10 distributed evenly over the entire surface of the cover.

[0065] Cooling of the components under the hood is thus made possible when the vehicle is stopped by the central passage and lateral passages for the flow of air, the latter being symmetrically distributed on either side of the central passage.

[0066] The hood 2 is intended for a vehicle, in particular an automobile, which is preferably of the type of a sporty vehicle for which lightness is sought in order to improve dynamic performance.

[0067] Thanks to the invention, the design constraint necessitates the use of a rigid and lightweight material, such as a fiber composite. The bonding of the outer skin 6 to a lining 7 is temperature-dependent under the hood, making it necessary to limit any temperature increase that could compromise the bond quality, as the bonding adhesives are more sensitive to temperature increases than the welding used for steel hoods.

[0068] With the hood of the invention, the static cooling of the components under the engine hood is improved by heat exchange with the outside air, in particular by convection, with a flow of hot air flowing through the various openings 31, 32, 33 passing through the hood 2.

[0069] Since the hood openings are related to means of collecting and draining rainwater when the vehicle is stationary, such as the collection boxes 21, 22, the components under the hood are protected from water received on the external face of the hood, this water being drained away by the various channels formed in the hood 2.

[0070] A vehicle with such a composite hood is lighter, which helps to provide exceptional sensations of power and speed to its driver.

Claims

1. Convection cooling device (1) for an engine compartment of a vehicle, comprising at least one passage (3) for the flow of a hot air stream coming from the engine, said passage being partly formed by an opening (31, 32, 33) through a bonnet (2) for closing the engine compartment, each opening (3) being formed by at least one external opening (311, 321, 331) provided through the bonnet outer skin (6) and at least one internal opening (312, 322, 332) provided through the bonnet lining (7), the external opening (311, 321, 331) extending in a plane approximately perpendicular to the plane of the internal opening (312, 322, 332), characterized in that the passage (3) is formed by a transversely extending central opening (33) and by at least one longitudinally extending lateral opening (31, 32), the central opening (33) comprising an external opening (331) separated from an internal opening (332) by a central water manifold (334), the lateral opening (31, 32) comprising an external opening (311, 321) separated from an internal opening (312, 322) by a lateral water manifold (314, 324), and in that the central or lateral water manifold (314, 324, 334) is of the header tank type delimited by a bottom wall (71) bordered by a peripheral wall (72) of the bonnet lining (7), the water manifold (314, 324, 334) comprising at least one gutter (317, 327, 337), notably of substantially longitudinal orientation, for the flow of the water collected towards the outside of the engine compartment.

2. Cooling device (1) according to the preceding claim, characterized in that the lateral opening (31, 32) is in relation to a lateral gutter (317, 327), and the central opening (33) is in relation to at least one central gutter (337), the lateral gutter (317, 327) emerging into the central gutter (337).

3. Device according to at least one of the preceding claims, characterized in that it comprises a protective grate (323, 333), notably a metal grate, extending at the opening (31, 32, 33).

4. Device according to at least one of the preceding claims, characterized in that the front end of the gutter (317, 327, 337) comprises at least one drainage hole (347), arranged notably at a front peripheral edge (4) of the bonnet (2).

5. Bonnet (2), notably for closing a vehicle engine compartment, characterized in that it comprises a cooling device according to any one of the preceding claims.

6. Vehicle, notably a motor vehicle, characterized in that it comprises a bonnet (2) according to the preceding claim.