Airflow generation device for motor vehicles

Abstract

A device for generating airflow for a motor vehicle, said device (1) comprising a housing (8) and a tangential blower (16), said housing (8) defining a passage (50) for the airflow exiting the blower (16), said blower (16) having an axis of rotation extending along a direction (Y), said longitudinally, said device comprising at least one acoustic screen (54), located at one end of said passage (50) along said longitudinal direction (Y). Figure for the abbreviation: Figure 3

Description

Title of the invention: Device for generating an air flow for a motor vehicle

[0001] The invention relates to a device for generating an air flow for a motor vehicle. Said air flow is intended to be diffused, in particular, into the passenger compartment of the vehicle.

[0002] In this field, ventilation, heating and / or air conditioning devices are known for directing an air flow towards passengers located behind the driver and / or the front passenger. It is also known to position these devices in the ceiling of the passenger compartment where they are concealed. Given the low height available, they comprise a tangential blower in order to generate the air flow. Indeed, such blowers have a small radial size favorable to positioning in a volume of low height and can conversely extend axially over a large dimension thus allowing the generated air flow to supply the passenger compartment over its entire width.

[0003] Despite their various advantages, it has however been found that these devices generate parasitic noise, detrimental to the comfort of passengers.

[0004] The invention aims to at least partially overcome the above drawbacks and to this end proposes a device for generating an air flow for a motor vehicle, said device comprising a housing and a tangential blower, said housing defining a passage for the air flow at the outlet of the blower, said blower having an axis of rotation extending in a direction, called longitudinal, said device comprising at least one acoustic screen, located at one end of said passage in said longitudinal direction.

[0005] It has been established by the applicant that the parasitic noises generated by this type of device come mainly from a turbulent flow of the air flow, at the outlet of the blower, in the vicinity of the longitudinal ends of the flow passage. The acoustic screen(s) positioned, in accordance with the invention, at this location thus make it possible to break the turbulent flow and thus limit its noise pollution.

[0006] According to various additional characteristics of the invention, which may be taken together or separately and which form as many embodiments of the invention: - the screen includes a foam block, - the screen includes a partition, - the device comprises another acoustic screen at another end of said passage in said longitudinal direction, said housing comprises two walls defining opposite ends of said passage in said longitudinal direction, said walls are oriented substantially transversely, in particular orthogonally, to said longitudinal axis, said screens are located against said walls, said walls comprise positioning keys for said screens, the minimum distance between said screen(s), on the one hand, and said blower, on the other hand, is at most 5 cm, preferably at most 2 cm, or even 1 cm, in one direction of the air flow, said housing defines a volute nose, extending in said longitudinal direction at the outlet of said blower, said screens are located near a longitudinal side of the passage opposite a longitudinal side of said passage connected to the volute nose, an extension of said screens is at most half of a dimension of said passage in a direction, called height of the passage, orthogonal to the direction of the air flow and to said longitudinal direction, an extension of said screens in said longitudinal direction is at most 2 cm, or even 1 cm, said pulser has a longitudinal extension substantially identical to a longitudinal dimension of said passage, said blower comprises a stack of wheels along said longitudinal axis, said wheels being provided with blades generating the suction of the air flow at the inlet and the discharge of the air flow at the outlet of said blower, each of said wheels is provided with blades having a regular angular spacing pitch from one blade to the other, the blades are offset by half a spacing pitch from one wheel to the other, said blower is located in a housing defined by said casing, said device comprises a heat exchanger, intended to cool and / or heat said air flow, said exchanger is located in said accommodation, said exchanger is located upstream of said blower in the direction of flow of the air flow, said device comprises one or more aerators at the outlet of said passage, said aerators are located substantially in the same plane, said plane extends parallel to said longitudinal direction, said device is configured to be housed in a ceiling of a passenger compartment of said vehicle.

[0007] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the detailed explanatory description which follows, of at least one embodiment of the invention given by way of purely illustrative and non-limiting example, with reference to the appended schematic drawings among which:

[0008] [Fig-1] schematically illustrates in longitudinal section view an example of device according to the invention;

[0009] [Fig.2] schematically illustrates in perspective a cross-sectional view of the device of [Fig.l] in which only a housing and a pulser of said device have been illustrated;

[0010] [Fig.3] schematically illustrates a cross-sectional view of the device of the preceding figures.

[0011] As illustrated in [Fig.l], the invention relates to a device 1 for generating an air flow for a motor vehicle.

[0012] Said device 1 is configured to be housed, for example, in a ceiling 2 of a passenger compartment of said vehicle. It is intended to direct said air flow, in particular, towards rear passengers of the vehicle, that is to say, passengers of the row(s) of seats located behind the driver and the front passenger of said vehicle. It is positioned, for example, between a trim wall 4 of said ceiling 2 and an upper face 6 of a body of the vehicle.

[0013] Said device comprises a housing 8. Said housing 8 is configured to allow suction of the air flow at one or more air inlet orifices 30, according to an arrow marked 32. Said housing 8 is further configured to allow expulsion of the air flow through one or more air outlet orifices 34, according to an arrow marked 36.

[0014] Said housing 8 is fixed, for example, to said upper face 6 of the bodywork, in particular by a first attachment rail 10, here located at the level of a center pillar 1 of said bodywork, and / or by a second attachment rail 14.

[0015] Said device further comprises a tangential pulser 16. Said pulser has an axis of rotation 18 extending in a direction, called longitudinal. An orthonormal reference frame is illustrated in the figures. It has an axis X, here oriented in a direction connecting a front face and a rear face of the vehicle, an axis Y, perpendicular to the plane of the figure and oriented in a direction connecting left and right sides of the vehicle and an axis Z, oriented in a vertical direction. It can be seen that said longitudinal direction corresponds to the direction Y, perpendicular to the plane of the figure. Said pulser 16 therefore extends here transversely in the passenger compartment of the vehicle.

[0016] Said pulser 16 is configured to generate a two-dimensional flow, that is to say, having streamlines remaining in a plane perpendicular to the longitudinal axis 18. In other words, here, said streamlines are located in planes oriented along the X and Z axes, parallel to the plane of the figure.

[0017] Said device preferably further comprises a heat exchanger 40, intended to cool and / or heat said air flow. Said heat exchanger 40 is configured to be traversed by a refrigerant fluid intended to exchange heat with said air flow. It comprises, for example, a heat exchange bundle 42, provided with tubes, traversed by said refrigerant fluid, and fins, arranged between the tubes and traversed by said air flow. Said device is supplied with refrigerant fluid, in particular, from a main heating, ventilation and / or air conditioning installation, for example arranged under a dashboard of said vehicle.

[0018] Said housing 8 defines a housing 44 accommodating said blower 16 and / or said heat exchanger 40. Said housing 8 defines in particular a volute nose 45, extending in said longitudinal direction Y at the outlet of said blower, here in the lower part.

[0019] Said heat exchanger 40 is preferably located upstream of said blower 16, according to the direction of flow of the air flow. In other words, here, said air flow enters the housing 8 through the air inlet(s) 30 and passes through the housing 44, first passing through said heat exchanger 40 and then said blower 16 before being expelled from said housing 8 through the outlet orifice(s) 34, this under the effect of the drive generated by said blower 16.

[0020] In [Fig. 2], said blower 16 has been illustrated in the housing 8 without the heat exchanger 40. Said blower 16 comprises, for example, a stack of wheels 20, said stack being oriented along said longitudinal axis 18. Said wheels 20 preferably have the same radius. Said blower 16 thus has a substantially cylindrical configuration. Said wheels 20 are provided with blades 22, generating the suction of the air flow at the inlet and the discharge of the air flow at the outlet of said blower 16, respectively according to an arrow marked 23 and according to an arrow marked 24.

[0021] The blades 22 have a small chord, for example lying in a direction of rotation of the blower 16. It is noted that a radius of said wheels 20 is much less than an extension of said stack of wheels 20 along said longitudinal axis 18.

[0022] Said blades 26 of the same one of said wheels 20 preferably have a regular angular spacing pitch from one blade to the other. The blades 26 are advantageously offset by half a spacing pitch from one wheel 20 to the other.

[0023] Still [Fig.2], it can be seen that said housing 8 defines a passage 50 for the air flow leaving the blower 16. Said passage 50 extends in the direction of flow of the air flow between said blower 16 and said outlet orifice(s) 34. It has a larger dimension in the direction of said longitudinal axis 18. It has two opposite longitudinal sides, here a lower longitudinal side 56 and an upper longitudinal side 58. Said housing 8 further comprises two walls 54, 54' defining opposite ends of said passage 50 in said longitudinal direction Y and connecting said longitudinal sides 56, 58. Said walls 54, 54' are oriented substantially transversely, in particular orthogonally, to said longitudinal axis Y, that is to say here in a plane X, Y.

[0024] Along one of the longitudinal sides, here the lower side 56, said passage 50 connects to the volute nose 45, at the end of said passage 50 opposite the air outlet orifice(s) 34.

[0025] As illustrated in [Fig. 3], according to the invention, said device comprises at least one acoustic screen 52, located at one end of said passage 50, in said longitudinal direction Y. Preferably, the device comprises another acoustic screen 52' at another end of said passage 50 in said longitudinal direction Y. Said screens 52, 52' have not been illustrated in Figures 1 and 2.

[0026] The applicant has been able to establish that such screens 52, 52' make it possible to limit, or even eliminate, noise generated by the device at the longitudinal ends of said passage 50, in particular by avoiding the establishment of a swirling flow of the air flow at this level.

[0027] According to a first embodiment, the screen 52 comprises a foam block. Alternatively, the screen 52 comprises a partition. According to a still different embodiment, the two previous variants are combined.

[0028] Said screens 52, 52' are located against said walls 54, 54', for example glued in the case of foam blocks or made of material in the case of partitions. Although this is not the case in the illustrated embodiment, said walls 54, 54' may include positioning keys for said screens 52, 52' to facilitate proper installation of the latter, while remaining within the scope of the invention.

[0029] From a dimensional point of view, the minimum distance between said screen(s) 52, 52', on the one hand, and said blower 16, on the other hand, is at most 5 cm, preferably at most 2 cm, or even 1 cm, in a direction of the air flow. An extension of said screens 52, 52' in said longitudinal direction Y is for example at most 2 cm, or even 1 cm.

[0030] Said screens 52, 52' are preferably located near the longitudinal side 58 of the passage 50, opposite a longitudinal side 56 of said passage 50 connected to the volute nose 45. In other words, here said screens 52, 52' are located near said upper longitudinal side 58. Advantageously, they extend from said longitudinal side 58, here downwards.

[0031] An extension of said screens 52, 52' is at most half of a dimension of said passage 50 in a direction, called height of passage 50, corresponding here to the distance between said lower longitudinal face 56 and said upper longitudinal face 58.

[0032] Preferably, said blower 16 has a longitudinal extension substantially identical to a longitudinal dimension of said passage 50. In other words, the spacing between said transverse walls 54, 54' of the housing 50 corresponds to the dimension of the blower 16 in said longitudinal direction Y.

[0033] Said device further comprises here a drive motor 60 for said blower 16. It is located in said housing 8, for example, in the longitudinal extension of said blower 16.

[0034] Referring again to Figures 1 and 2, it can be seen that said device also comprises one or more aerators 62, at the outlet of said passage 50. Said aerators 50 are located substantially in the same plane P. Said plane extends, for example, parallel to said longitudinal direction Y. It could be a plane P oriented with a slight angular deviation relative to a plane Y, Z so as to allow the air flow to pass in a downward direction. Said aerators 62 are advantageously configured to allow adjustment of an orientation and / or the flow rate of the air flow, in particular by means of an articulated grille.

Claims

Claims

1. Device for generating an air flow for a motor vehicle, said device (1) comprising a housing (8) and a tangential blower (16), said housing (8) defining a passage (50) for the air flow at the outlet of the blower (16), said blower (16) having an axis of rotation (18) extending in a direction (Y), called longitudinal, said device comprising at least one acoustic screen (52, 52'), located at one end of said passage (50) in said longitudinal direction (Y).

2. Device according to claim 1 wherein said screen (52, 52') comprises a foam block.

3. Device according to any one of the preceding claims in which said housing (8) defines a volute nose (45), extending in said longitudinal direction (Y) at the outlet of said blower (16), said screen (52, 52') being located near a longitudinal side (58) of the passage (50) opposite a longitudinal side (56) of said passage (50) connected to the volute nose (45).

4. Device according to any one of the preceding claims in which an extension of said screen (52, 52') is at most half of a dimension of said passage (50) in a direction, called height of the passage, orthogonal to the direction of the air flow and to said longitudinal direction (Y).

5. Device according to any one of the preceding claims in which an extension of said screen (52, 52') in said longitudinal direction is at most 2 cm, or even 1 cm.

6. Device according to any one of the preceding claims in which the minimum distance between said screen (52, 52'), on the one hand, and said blower (16), on the other hand, is at most 5 cm, preferably at most 2 cm, or even 1 cm in a direction of the air flow.

7. Device according to any one of the preceding claims comprising another acoustic screen at another end of said passage (50) in said longitudinal direction (Y).

8. Device according to the preceding claim wherein said housing (8) comprises two walls (54, 54') defining opposite ends of said passage (50) in said longitudinal direction (Y), said screens (52, 52') being located against said walls (54, 54').

9. Device according to any one of the preceding claims in which said pulser (16) has a longitudinal extension sens-

10. possibly identical to a longitudinal dimension of said passage (50). Device according to any one of the preceding claims comprising one or more aerators (62) at the outlet of said passage (50).

Images