Assembly comprising an air intake duct and a protective grille

Abstract

The invention relates to an assembly (1) comprising: a housing (3) forming a main air duct, an air intake duct (4) connected to the housing (3) and configured to convey an airflow into the housing (3), a protective grille (2) arranged in the housing (3) and configured to be traversed by the airflow conducted by the air intake duct (4), wherein the protective grille comprises: a frame (7) forming a main plane (14) of the protective grille (2), at least three fins (8) spaced apart from one another and carried by the frame (7), and wherein at least three of these fins form, with the main plane of the protective grille, angles αa, αb, αc, with αa < αb < αc.

Description

[0001] DESCRIPTION

[0002] Title: Assembly comprising an air intake duct and a protective grille

[0003] [1] The present invention relates to an assembly comprising an air intake duct, at least one heat exchanger and a protective grille configured to protect this heat exchanger. The protective grille allows the passage of an air flow through the heat exchanger while protecting it from possible debris.

[0004] [2] Patent application EP3943865 discloses an assembly comprising a heat exchanger comprising heat transfer fluid circulation tubes and a protective grid configured to protect this heat exchanger. The protective grid therefore protects at least a portion of the heat exchanger against stone impacts.

[0005] [3] However, the protective grille creates a disturbance in the air flow passing through the exchanger, which reduces the performance of this exchanger.

[0006] [4] The invention aims to propose an optimization of the protective grid providing a certain number of advantages as will be seen below.

[0007] [5] The invention relates to an assembly comprising: a housing forming a main air duct, an air intake duct connected to the housing, and configured to conduct an air flow into the housing, a protective grille placed in the housing and configured to be crossed by the air flow conducted by the air intake duct, the protective grille comprising:

[0008] • a frame forming a main plane of the protective grid,

[0009] • at least three fins spaced from each other and carried by the frame, at least three of these fins forming angles aa, ab, ac with the main plane of the protective grid, with aa < ab < ac. [6] A low side and a high side of the protective grid are defined, as well as a height axis between this high side and this low side of the protective grid. It is thus possible to associate with each point on the main plane of the protective grid a height on the protective grid, this height being between 0 and the height Hg of the protective grid.

[0010] [7] According to one aspect of the invention, the protective grid is planar in shape, and the principal plane of the protective grid is the median plane of the grid.

[0011] [8] Alternatively, the protective grid may be of any other shape, including a curved shape.

[0012] [9] According to one aspect of the invention, the protective grid is made of plastic.

[0013]

[0010] Alternatively, the protective grid is metallic, in particular made of aluminum or aluminum alloy.

[0014]

[0011] According to one aspect of the invention, the protective grid is produced by injection.

[0015]

[0012] According to one aspect of the invention, each fin of the protective grid is in the form of a longitudinal strip.

[0016]

[0013] According to one aspect of the invention, the protective grid comprises at least one crosspiece which connects the fins, being perpendicular to the fins.

[0017]

[0014] According to one aspect of the invention, the protective grid comprises a plurality of crosspieces which connect the fins, being perpendicular to the fins, and these crosspieces are in particular regularly spaced along the fins.

[0018]

[0015] According to one aspect of the invention, the sleepers are in the form of strips of material.

[0019]

[0016] According to one aspect of the invention, the protective grid, with the fins and the crosspieces, is made in one piece.

[0020]

[0017] According to one aspect of the invention, the frame has a substantially rectangular shape.

[0021]

[0018] According to one aspect of the invention, the protective grid comprises at least 20 fins, in particular at least 30 fins, in particular at least 40 fins, for example 50 fins.

[0019] According to one aspect of the invention, each fin is of elongated shape, in particular with an aerodynamic profile.

[0022]

[0020] According to one aspect of the invention, each fin is of substantially planar shape.

[0023]

[0021] According to one aspect of the invention, all of the fins are identical.

[0024]

[0022] Alternatively, some fins may have different shapes, including different profiles.

[0025]

[0023] According to one aspect of the invention, a main plane of the fin is thus defined for each fin, and the angle ai is defined as the angle formed in the counterclockwise direction between the main plane of the fin and the main plane of the protective grid.

[0026]

[0024] According to one aspect of the invention, the fins extend laterally along the entire length of the protective grid.

[0027]

[0025] According to one aspect of the invention, each fin comprises a main axis included in the main plane of the protective grid, and parallel to the top and bottom sides of the protective grid.

[0028]

[0026] According to one aspect of the invention, a height Hi of the fin on the protective grid is defined for each fin.

[0029]

[0027] According to one aspect of the invention, the fins are separated by a gap allowing the passage of air.

[0030]

[0028] According to one aspect of the invention, the fins are distributed regularly between the high sides and low sides of the frame of the protective grid, and the intervals between the fins are identical between each of the fins.

[0031]

[0029] Alternatively, at least one gap between two fins of the protective grid is of a different length from the other gaps.

[0032]

[0030] According to one aspect of the invention, the intervals between the fins have a length Li of between 1 mm and 10 mm, in particular less than 8 mm.

[0033]

[0031] According to one aspect of the invention, air flow lines are defined representing the flow of the air flow through the protective grille.

[0032] According to one aspect of the invention, the air flow lines of the air flow intersect the main plane of the protective grille at an angle depending on the height on the main plane of the protective grille.

[0034]

[0033] According to one aspect of the invention, the angle ai formed by each fin with the main plane of the protective grid is defined so as to control the impact of the fin on the passage of the air flow.

[0035]

[0034] In particular, the angle ai formed by each fin with the main plane of the protective grid is defined so as to minimize the impact of the fin on the passage of the air flow.

[0036]

[0035] According to one aspect of the invention, the angle ai formed by each fin with the main plane of the protective grid is equal to the angle formed at the intersection of the flow lines and the main plane of the protective grid at the height of the fin.

[0037]

[0036] According to one aspect of the invention, the angles ai formed by the fins with the main plane of the protective grid evolve monotonically from the bottom to the top of the protective grid over at least a portion of the protective grid.

[0038]

[0037] According to one aspect of the invention, the angles ai formed by the fins with the main plane of the protective grid evolve monotonically between the low side and the high side of the protective grid.

[0039]

[0038] According to one aspect of the invention, the angles ai formed by the fins with the main plane of the protective grid evolve in an increasing manner from the low side to the high side of the protective grid.

[0040]

[0039] Alternatively, the angles ai formed by the fins with the main plane of the protective grid evolve in a decreasing manner from the low side to the high side of the protective grid.

[0041]

[0040] According to one aspect of the invention, the air intake duct comprises at least one air inlet and at least one air outlet, and is arranged to conduct the air flow from the air inlet of the air intake duct to the air outlet of the air intake duct.

[0042]

[0041] According to one aspect of the invention, the air inlet of the air intake duct has, for example, a substantially rectangular perimeter.

[0042] According to one aspect of the invention, the air outlet of the air intake duct has, for example, a substantially rectangular perimeter.

[0043]

[0043] According to one aspect of the invention, the surface area of ​​the air inlet of the air intake duct is for example smaller than the surface area of ​​the air outlet of the air intake duct, for example at least twice smaller.

[0044]

[0044] According to one aspect of the invention, the housing and the air intake duct are formed from a single block.

[0045]

[0045] Alternatively, the housing and the air intake duct are two separate parts.

[0046]

[0046] According to one aspect of the invention, the air intake duct is connected to the housing.

[0047]

[0047] In particular, the air outlets of the air intake duct are connected to the housing.

[0048]

[0048] According to one aspect of the invention, the protective grille has a height greater than the air outlets of the air intake duct.

[0049]

[0049] According to one aspect of the invention, the air outlets of the air intake duct are rectangular in shape.

[0050]

[0050] According to one aspect of the invention, the air outlets of the air intake duct are rectangular and coplanar, and define a plane of the air outlets of the air intake duct.

[0051]

[0051] According to one aspect of the invention, a main axis of the air outlet is defined, normal to the plane of the air outlets, and passing through the center of an air outlet.

[0052]

[0052] According to one aspect of the invention, the main axis of the air outlet is parallel to the air flow circulating in the air intake duct.

[0053]

[0053] According to one aspect of the invention, the air intake duct comprises a single air outlet.

[0054]

[0054] According to one aspect of the invention, the air outlet of the air intake duct is placed opposite the bottom of the protective grille.

[0055]

[0055] According to one aspect of the invention, the angles of inclination ai of the fins are distributed asymmetrically with respect to a center line of the grid, in particular if the air outlet is positioned closer to one side of the protective grid than to the other opposite side.

[0056] According to one aspect of the invention, the protective grid comprises a group of low fins comprising the fins placed closest to the low side of the protective grid, and the angles ai formed with the main plane of the protective grid by these low fins are between 70° and 110°, in particular between 80° and 100°, in particular between 85° and 95°, in particular equal to 90°.

[0056]

[0057] According to one aspect of the invention, the protective grid comprises a group of high fins comprising the fins placed closest to the high side of the protective grid, and the angles ai formed with the main plane of the protective grid by these high fins are between 90° and 180°, in particular between 100° and 150°.

[0057]

[0058] According to one aspect of the invention, the air intake duct comprises a plurality of air outlets, and the height of the protective grille can be divided into a series of N intervals { li = [0, Li[ ; I2 = [Li, Lz[ ; ... ; IN = [LN-I, Hg]}, with N the number of air outlets of the air intake duct.

[0058]

[0059] According to one aspect of the invention, the height of the protective grille is thus divided into as many intervals as the air intake duct has air outlets.

[0059]

[0060] According to one aspect of the invention, the angles ai formed with the main plane of the protective grid by the fins evolve monotonically over each of the intervals lk.

[0060]

[0061] According to one aspect of the invention, the angles ai vary monotonically as the fins move away from the air outlets.

[0061]

[0062] According to one aspect of the invention, the angles ai increase as the fins move away from the air outlets.

[0062]

[0063] Alternatively, the angles ai decrease as the fins move away from the air outlets.

[0063]

[0064] According to one aspect of the invention, each interval lk of the protective grid is placed opposite an air outlet of the air intake duct, and configured to be crossed by the air flow leaving this air outlet.

[0064]

[0065] According to one aspect of the invention, a flat fin, namely forming an angle ai substantially equal to 90°, is placed at heights Li, L2, ..., LN-I, namely at the junction between the intervals lk corresponding to the different air outlets.

[0066] According to one aspect of the invention, the air intake duct comprises two air outlets.

[0065]

[0067] According to one aspect of the invention, an air outlet of the air intake duct is placed opposite the top of the protective grille, and an air outlet of the air intake duct is placed opposite the bottom of the protective grille.

[0066]

[0068] According to one aspect of the invention, an air outlet of the air intake duct is aligned with the high side of the protective grille, and an air outlet of the air intake duct is aligned with the low side of the protective grille.

[0067]

[0069] According to one aspect of the invention, at least one air outlet is offset relative to the high and low sides of the protective grille, i.e. is not placed opposite either the high side or the low side of the protective grille.

[0068]

[0070] According to one aspect of the invention, the protective grid is divided in its height into two intervals 11 and 12. In particular, the interval 11 represents substantially the lower half of the protective grid, and 12 the upper half of the protective grid.

[0069]

[0071] According to one aspect of the invention, the angles ai formed with the main plane of the protective grid by the fins placed in the interval 11 increase when the height Hi of placement of the fins increases, and the angles ai formed with the main plane of the protective grid by the fins placed in the interval 12 increase when the height Hi of placement of the fins increases.

[0070]

[0072] According to one aspect of the invention, the increment step of the angle between two adjacent fins is for example between 0.1° and 5°.

[0071]

[0073] Alternatively, the angles increase in steps, i.e. there are groups of fins parallel to each other. For example, fins placed in the same interval Ik are parallel to each other.

[0072]

[0074] For example there are at least two groups, including at least three groups of parallel fins.

[0073]

[0075] According to one aspect of the invention, the assembly comprises at least one heat exchanger placed behind the protective grille in the direction of circulation of the air flow.

[0074]

[0076] According to one aspect of the invention, the heat exchanger comprises heat transfer fluid circulation tubes.

[0077] According to one aspect of the invention, the heat transfer fluid circulation tubes of the heat exchanger are made of metallic material and spaced apart from each other so as to allow a flow of air to pass between the tubes.

[0075]

[0078] According to one aspect of the invention, each heat transfer fluid circulation tube of the heat exchanger is positioned opposite one of the fins of the protective grid.

[0076]

[0079] According to one aspect of the invention, the heat exchanger is rectangular in shape, and comprises a main plane parallel to the main plane of the protective grid. The heat exchanger is, for example, a radiator for a thermal management loop of a motor vehicle.

[0077]

[0080] Alternatively, the main plane of the protective grid and the main plane of the heat exchanger are intersecting.

[0078]

[0081] According to one aspect of the invention, the assembly comprises a motor-fan unit configured to generate the air flow passing through the air intake duct and the protective grille.

[0079]

[0082] According to one aspect of the invention, the motor-fan unit is placed behind the protective grille and at least one heat exchanger in the direction of circulation of the air flow.

[0080]

[0083] According to one aspect of the invention, the protective grille is placed perpendicular to the air flow.

[0081]

[0084] In particular, the main plane of the protective grille is normal to the main axis of the air outlet of the air intake duct.

[0082]

[0085] Alternatively, the protective grille is inclined relative to the air flow, and the main plane of the protective grille forms an angle |3 with the main axis of the air outlet, in particular an angle |3 of between 20° and 90°.

[0083]

[0086] According to one aspect of the invention, the assembly is configured to be mounted on a vehicle, in particular a motor vehicle.

[0084]

[0087] A heat exchanger is, for example, a radiator for cooling a vehicle engine by means of a coolant cooled by air circulating through the radiator. To obtain an air flow through the radiator, it is placed on the front of the vehicle, for example.

[0088] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and several examples of embodiment given for informational and non-limiting purposes with reference to the appended schematic drawings on the other hand, in which:

[0085]

[0089] [Fig 1] Figure 1 is a perspective representation of an assembly according to the invention comprising an air intake duct and a protective grille;

[0086]

[0090] [Fig. 2] Figure 2 is a perspective representation of an assembly according to the invention comprising an air intake duct and a protective grille;

[0087]

[0091] [Fig. 3] Figure 3 is a perspective representation of a protective grid of an assembly according to the invention.

[0088]

[0092] [Fig. 4] Figure 4 is a schematic sectional view of an assembly according to the invention.

[0089]

[0093] [Fig. 5] Figure 5 is a schematic sectional view of an assembly according to the invention, in which the protective grille is inclined relative to the air flow.

[0090]

[0094] [Fig. 6] Figure 6 is a schematic sectional view of an assembly according to the invention, in which the air intake duct comprises two air outlets.

[0091]

[0095] [Fig. 7] Figure 7 is a schematic sectional view of an assembly according to the invention in which the housing and the air intake duct are formed from a single block.

[0092]

[0096] The features, variants and different embodiments of the invention may be combined with each other in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0093]

[0097] Figures 1 and 2 show an assembly 1 according to the invention.

[0094]

[0098] The assembly 1 comprises a housing 3 forming a main air duct in which a protective grille 2 shown in Figure 3 is placed. The protective grille 2 is for example made of plastic, in particular by molding.

[0095]

[0099] Assembly 1 includes an air intake duct 4 connected to housing 3.

[0100] The air intake duct 4 comprises an air inlet 5, an air outlet 6 connected to the housing 3, and is configured to conduct an air flow from the air inlet 5 to the housing 3.

[0096]

[0101] The protective grille 2 is configured to be crossed by the air flow conducted by the air intake duct 4. The air intake duct 4 thus forms a sort of envelope for channeling the air flow.

[0097]

[0102] The protective grille 2 has a greater height than the air outlet 6 of the air intake duct 4.

[0098]

[0103] The assembly 1 comprises a heat exchanger 15, not shown in figures 1 and 2, placed behind the protective grille 2 in the direction of circulation of the air flow.

[0099]

[0104] The heat exchanger 15, for example a radiator for a thermal management loop of a motor vehicle, comprises heat transfer fluid circulation tubes, these tubes being made of metallic material and spaced apart from each other so as to allow a flow of air to pass between the tubes, and each tube being positioned opposite one of the fins of the protective grid 2. According to a variant, several heat exchangers 15 can be placed behind the protective grid.

[0100]

[0105] Each heat transfer fluid circulation tube is positioned opposite one of the fins 8 of the protective grid 2.

[0101]

[0106] The heat exchanger 15 is rectangular in shape, and has a main plane parallel to the main plane of the protective grid.

[0102]

[0107] The assembly 1 comprises a motor-fan unit 13, here of the electric type, configured to generate the air flow passing through the air intake duct 4 and the protective grille 2.

[0103]

[0108] The motor-fan unit 13 is placed behind the protective grille 2 and the heat exchanger 15 in the direction of circulation of the air flow.

[0104]

[0109] Figure 3 shows a protective grid 2 according to the invention.

[0105]

[0110] The protective grid 2 is of planar shape, and the main plane of the protective grid 14, not shown in this figure, is the median plane of the protective grid 2.

[0111] According to an embodiment not shown, the protective grid 2 may be of any other shape, in particular a curved shape.

[0106]

[0112] The protective grid 2 comprises a rectangular frame 7 forming the main plane of the protective grid 14, and fins 8 spaced from each other and carried by the frame 7 of the protective grid 2.

[0107]

[0113] The fins 8 of the protective grid 2 are separated by a gap allowing the passage of air.

[0108]

[0114] The protective grid comprises at least 30 fins 8, distributed regularly between the upper sides 9 and lower sides 10 of the frame 7 of the protective grid 2. The intervals are therefore identical between each of the fins 8.

[0109]

[0115] The intervals between the fins 8 measure less than 8mm, for example 5mm.

[0110]

[0116] We define a high side 9 and a low side 10 of the protective grid 2, as well as a height axis between these sides. We can thus associate with each point on the main plane of the protective grid 2 a height on the grid, this height being between 0 and the height Hg of the protective grid.

[0111]

[0117] We therefore define for each fin a height Hi of the fin 8 on the protection grid 2.

[0112]

[0118] Each fin 8 of the protective grid 2 is in the form of a longitudinal strip, and is of substantially flat shape.

[0113]

[0119] In an embodiment not shown, each fin 8 is of elongated shape, in particular with an aerodynamic profile.

[0114]

[0120] The fins 8 extend laterally along the entire length of the protective grid 2, and have a main axis included in the main plane of the protective grid and parallel to the top 9 and bottom 10 sides of the protective grid 2.

[0115]

[0121] The protective grid 2 comprises a plurality of crosspieces 11 which connect the fins, being perpendicular to the fins, and these crosspieces are in particular regularly spaced along the fins.

[0116]

[0122] The crosspieces 11 are in the form of strips of material.

[0117]

[0123] The protective grid 2, with the fins 8 and the crosspieces 11, is made in one piece.

[0124] Figure 4 shows a schematic sectional view of an assembly according to the invention.

[0118]

[0125] Four fins 8 numbered from 1 to 4 are shown, spaced apart from each other and carried by the frame 7 of the protective grid 2.

[0119]

[0126] We thus define for each fin 8 a principal plane of the fin, and an angle ai formed between the principal plane of the fin and the principal plane 14 of the protective grid 2.

[0120]

[0127] The four fins 8 form angles a1, a2, a3 and a4 with the main plane 14 of the protective grid 2, these angles all being different. There are therefore 3 angles aa, ab, ac formed by 3 fins with the main plane l' of the protective grid 2, such that aa < ab < ac.

[0121]

[0128] The flow lines of the air flow passing through the assembly 1 and representing the flow of the air flow through the protective grille 2 are also shown.

[0122]

[0129] These flow lines intersect the main plane 14 of the protective grid 2 with an angle depending on the height on the main plane 14 of the protective grid 2.

[0123]

[0130] A main axis of the air outlet 6 is defined, normal to the plane of the air outlet, and passing through the center of the air outlet 6.

[0124]

[0131] The main axis of the air outlet 6 is parallel to the air flow circulating in the air intake duct 4.

[0125]

[0132] The protective grille 2 is placed perpendicular to the air flow, that is to say that the main plane 14 of the protective grille 2 is normal to the main axis of the air outlet 6 of the air intake duct 4.

[0126]

[0133] The angle ai formed by each fin 8 with the main plane 14 of the protective grid 2 is defined so as to control, in particular so as to minimize the impact of the fin 8 on the passage of the air flow.

[0127]

[0134] In particular, the angle ai formed by each fin 8 with the main plane 14 of the protective grid 2 is equal to the angle formed at the intersection of the flow lines and the main plane 14 of the protective grid 2 at the height Hi of the fin 8.

[0128]

[0135] The air intake duct 4 comprises a single rectangular air outlet 6 placed opposite the bottom of the protective grille 2.

[0136] The air outlet 6 of the air intake duct 4 is positioned closer to the low side 10 of the protective grille 9 than to the high side of the protective grille.

[0129]

[0137] The inclination angles ai of the fins 8 are distributed asymmetrically with respect to a center line of the protective grid 2.

[0130]

[0138] In particular, the angles ai formed by the fins 8 with the main plane of the protective grid 2 evolve monotonically, here in an increasing manner, over at least a portion of the protective grid 2, here from the low side 10 to the high side 9 of the protective grid.

[0131]

[0139] The incremental step of the angle between two adjacent fins is for example between 0.1° and 5°. This incremental step is not visible in the schematic figures, where a limited number of fins is shown for reasons of readability.

[0132]

[0140] According to an embodiment not shown, the angles ai formed by the fins 8 with the main plane of the protective grid 2 evolve in an increasing manner from the low side 10 to the high side 9 of the protective grid 2.

[0133]

[0141] Figure 5 shows an assembly 1 according to the invention, in which the protective grille 2 is inclined relative to the air flow.

[0134]

[0142] The protective grille 2 is inclined relative to the air flow, and the main plane 14 of the protective grille 2 forms with the main axis of the air outlet 6 of the air intake duct 4 an angle |3, in particular an angle |3 of between 20° and 90°.

[0135]

[0143] Figure 6 shows an assembly according to the invention in which the air intake duct 4 comprises two air outlets 6.

[0136]

[0144] The two air outlets 6 of the air intake duct 4 are rectangular and coplanar.

[0137]

[0145] The height of the protective grid 2 is divided into a series of N intervals {Il = [0, Ll[ ; 12 = [Ll, L2[ ; ... ; IN = [LN-1, Hg]}, with N the number of air outlets 6 of the air intake duct 4, here 11 = [0, Ll [ ; 12 = [Ll, Hg ].

[0138]

[0146] The height of the protective grille 2 is thus divided into as many intervals as the air intake duct 4 has air outlets 6.

[0139]

[0147] In a mode of representation not shown, the air intake duct 4 comprises N air outlets, with N > 2.

[0148] Here, the air intake duct 4 comprises two air outlets 6, and the protective grille is divided in its height into two intervals 11 and 12. In particular, the interval 11 represents substantially the lower half of the protective grille 2, and 12 the upper half of the protective grille 2.

[0140]

[0149] An air outlet 6 of the air intake duct 4 is placed opposite the top of the protective grille 2, and an air outlet 6 is placed opposite the top of the protective grille 2.

[0141]

[0150] Each interval Ik of the protective grid 2, here the intervals li and I2, is placed opposite an air outlet 6 of the air intake duct 4, and configured to be crossed by the air flow leaving this air outlet 6.

[0142]

[0151] The protective grid 2 comprises a group of low fins comprising the fins placed closest to the low side of the protective grid, here the fins in the interval li, and a group of high fins comprising the fins placed closest to the high side of the protective grid, here the fins in the interval I2.

[0143]

[0152] The angles ai formed with the main plane of the protective grid by the lower fins are between 70° and 110°, in particular between 80° and 100°, in particular between 85° and 95°, in particular equal to 90°, and the angles ai formed with the main plane of the protective grid by these upper fins are between 90° and 180°, in particular between 100° and 150°.

[0144]

[0153] The angles ai formed with the main plane 14 of the protective grid 2 by the fins evolve monotonically over each of the intervals.

[0145]

[0154] The angles ai vary monotonically as the fins 8 move away from the air outlets 6 of the air intake duct 4.

[0146]

[0155] Here, the angles ai formed with the main plane 14 of the protective grid 2 by the fins 8 placed in the interval li increase when the height Hi of placement of the fins increases, and the angles ai formed with the main plane 14 of the protective grid 2 by the fins placed in the interval I2 increase when the height Hi of placement of the fins 8 increases.

[0147]

[0156] A flat fin 8, namely forming an angle substantially equal to 90°, is placed at heights L1, L2,...,LN-1, namely at the junction between the intervals Ik corresponding to the different air outlets. Here, a flat fin 8 is placed at height L1, at the junction between the intervals 11 and 12.

[0148]

[0157] Alternatively, the angles increase in steps, i.e. there are groups of fins parallel to each other. For example, fins placed in the same interval Ik are parallel to each other.

[0149]

[0158] For example there are at least two groups, including at least three groups of 8 parallel fins.

[0150]

[0159] Figure 7 shows an assembly 1 according to the invention in which the housing 3 and the air intake duct 4 are formed from a single block.

[0151]

[0160] The air intake duct 4 has two air outlets 6, rectangular and coplanar.

[0152]

[0161] The height of the protective grid 2 is divided into two intervals { 11 = [0, Ll [ ; 12 = [Ll, L2]}

[0153]

[0162] The air outlets 6 of the air intake duct 4 are offset relative to the upper 9 and lower 10 sides of the protective grille 2, i.e. are not placed opposite either the upper 9 or the lower 10 side of the protective grille 2.

[0154]

[0163] The protective grid 2 comprises a group of low fins comprising the fins placed closest to the low side of the protective grid, here the fins in the interval li, and a group of high fins comprising the fins placed closest to the high side of the protective grid, here the fins in the interval I2.

[0155]

[0164] The angles ai formed with the main plane 14 of the protective grid 2 by the fins evolve monotonically over each of the intervals.

Claims

CLAIMS

1. Assembly (1) comprising: a housing (3) forming a main air duct, an air intake duct (4) connected to the housing (3), and configured to conduct an air flow into the housing (3), a protective grille (2) placed in the housing (3), and configured to be crossed by the air flow conducted by the air intake duct (4), the protective grille comprising: • a frame (7) forming a main plane (14) of the protective grid (2), • at least three fins (8) spaced from each other and carried by the frame (7), at least three of these fins forming with the main plane of the protective grid angles aa, ab, ac, with aa < ab < ac.

2. An assembly (1) according to claim 1, wherein the fins (8) are distributed evenly between the high sides (9) and low sides (10) of the frame of the protective grille (2), and the intervals between the fins (8) are identical between each of the fins.

3. Assembly (1) according to one of the preceding claims, in which the angle ai formed by each fin (8) with the main plane (14) of the protective grid (2) is equal to the angle formed at the intersection of the flow lines and the main plane (14) of the protective grid (2) at the height of the fin (8).

4. Assembly (1) according to one of the preceding claims, in which the angles ai formed by the fins (8) with the main plane (14) of the protective grid (2) evolve monotonically from the bottom to the top of the protective grid over at least a portion of the protective grid (2), in particular from the bottom side (10) to the top side (9) of the protective grid (2).

5. Assembly (1) according to one of the preceding claims, in which the air intake duct (4) comprises a single air outlet (6), and the air outlet (6) is placed opposite the bottom of the protective grille (2).

6. Assembly (1) according to one of claims 1 to 4, in which the air intake duct (4) comprises two air outlets (6).

7. An assembly (1) according to claim 6, wherein an air outlet (6) is placed opposite the top of the protective grille (2), and an air outlet (6) is placed opposite the bottom of the protective grille (2).

8. Assembly (1) according to one of the preceding claims, in which the angles ai vary monotonically as the fins (8) move away from the at least one air outlet (6) of the air duct (4).

9. Assembly (1) according to one of the preceding claims, in which the height of the protective grid (2) is divided into a series of N intervals { Il = [0, Ll[ ; 12 = ] Ll, L2[ ; ... ; IN = ] LN-1, Hg]} with N the number of air outlets (6) of the air intake duct (4), and the angles ai formed with the main plane (14) of the protective grid (2) by the fins (8) evolve monotonically over each of the intervals lk, with 2 < k < N.

10. Assembly (1) according to one of the preceding claims, in which the air intake duct (4) comprises two air outlets (6), and the protective grille (2) is divided in its height into two intervals 11 and 12, such that: the interval 11 represents substantially the lower half of the protective grille (2) and the angles ai formed with the main plane (14) of the protective grille (2) by the fins (8) placed in the interval 11 decrease when the height Hi of placement of the fins (8) increases, the interval 12 represents substantially the upper half of the protective grille (2) and the angles ai formed with the main plane (14) of the protective grille (2) by the fins (8) placed in the interval 12 increase when the height Hi of placement of the fins (8) decreases.

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