JP2009512588A - Automotive ventilator with noise reduction means - Google Patents

Abstract

  The invention relates to a ventilator for a motor vehicle, which is connected to a ventilation unit which sends air to the duct and which comprises at least one ventilation duct (2) connected to an inlet (4) leading to the passenger compartment of the vehicle. The duct (2) includes an air circulation pipe (10) and a blind hollow portion (12), and the opening (14) of the hollow portion of the blind hollow portion is disposed substantially perpendicular to the axis of the pipe. The invention also relates to an automotive instrument panel comprising at least one central ventilation inlet (4) leading to the cabin, the ventilation duct (2) being arranged approximately in the center of the instrument panel and connected to the aforementioned inlet (4) is doing. The present invention also relates to a vehicle including the ventilation device described above, which serves as an acoustic device for the vehicle.

Description

  The present invention relates to a ventilating apparatus for an automobile provided with noise reducing means.

  It is well known that an automobile ventilator comprises a ventilation or air conditioning unit that sends cooled or heated air via individual ventilation ducts, the outlet of which is open towards the interior of the vehicle.

  These devices generate undesirable noise that has become more audible to the driver as a result of recent improvements from the standpoint of running the internal combustion engine more quietly.

  This undesirable noise is caused by ventilation and turbulence generated by the air conditioning unit fan and in the air flowing through the duct. This noise is sent to the inside of the vehicle via the ventilation duct.

  There are various solutions that have been made in an attempt to reduce undesirable noise generated in ventilators.

  One of these solutions is described in EP 1403105 A1. The solution is to create a hollow part on the ventilation duct with a cross section larger than that of the remaining duct. The hollow part has a frusto-conical shape, and the radius part extends in the direction of the duct perpendicular to the air flow along the ventilation duct. The hollow part opens toward the duct at the mouth of the hollow part formed in the longitudinal direction with respect to the flow.

  Another solution is described in FR28222225 A1. The solution is to create a hollow in the ventilation duct that is formed perpendicular to the air flow along the ventilation duct and radially to the direction of the duct. The hollow part opens toward the duct at the mouth of the hollow part in the longitudinal direction with respect to the flow. In other words, the connection between the duct wall and the hollow wall has a generatrix parallel to the duct axis. The axis of the hollow inlet is perpendicular to the flow along the duct.

  Other publications also disclose solutions with ducts, the duct openings being formed substantially parallel to the flow, these references are FR2780347, JP60099948, JP7251628. In these documents, the inlet or throat of the hollow can be mimicked by a resonator and is located at right angles to the flow along the duct.

  Another solution is described in FR2712851 A1. The solution is to form hollow parts in the ventilation duct with a cross section larger than that of the remaining ducts, which are filled with foam.

  However, these known solutions are not completely satisfactory.

  One object of the present invention is to improve the known solutions as described above.

  Another object of the present invention is to create a ventilator with noise reduction means that is effective and economical to implement.

  The present invention relates to a motor vehicle ventilator comprising at least one ventilation duct which is connected on the one hand to a ventilation unit which sends air to the duct and on the other hand to a vent opening which opens towards the interior of the vehicle. The duct comprises an air flow pipe and a blind hollow, the mouth of the blind hollow being located substantially perpendicular to the axis of the pipe. In this way, the mouth of the hollow part faces the air flow along the pipe upstream of the mouth of the hollow part. In other words, the axis of the inlet to the hollow is parallel to the air flow along the pipe upstream of the mouth of the hollow.

  In the mouth of the hollow part, the wall of the duct reaches the wall of the hollow part, that is, the peripheral part of the inlet of the hollow part.

  The duct includes an upstream first portion in the first direction and a downstream second portion in which the pipe runs in the second direction, and the hollow portion is a pipe in which the hollow portion is the first portion. It is advantageous because it is located in the second part so that it lies on a substantially extended line.

  Advantageously, the duct comprises a third part downstream in the third direction, the second part being an intermediate part, where the air flow is branched between the first and third parts.

  This is advantageous because the cross section of the mouth of the hollow part is smaller than half the cross section of the pipe along the mouth of the hollow part.

  Advantageously, the hollow part comprises a throat part connected to the mouth of the hollow part, and the cross section of the throat part is smaller than the cross section of the remaining part of the hollow part.

  This is advantageous because the hollow portion is delimited by the peripheral wall of the duct and the internal partition of the duct, and the internal partition is located substantially in the vertical direction in the air flow direction and is a wall that delimits the pipe.

  The hollow portion and the pipe are separated by the peripheral wall of the duct and the partition inside the duct, which is advantageous because the partition inside becomes a reinforcing material for the duct.

  Advantageously, the device comprises two ducts, the hollow part of at least one duct connecting the pipe of said duct to the pipe of the other duct, the hollow part being in the center of said pipe.

  In other words, the two ducts according to the present invention have pipes connected via the central hollow portion, which is one hollow portion for each duct or one hollow portion common to the ducts.

  The hollow portion is delimited by a peripheral wall of the duct, which is a wall that fixes the duct in cooperation with the vehicle components.

  The present invention relates to a vehicle dashboard comprising at least one central air vent opening towards the interior, the dashboard comprising at least one ventilation device according to the invention, wherein the ventilation duct is substantially in the middle of the dashboard. And is connected to the vent.

  The invention also relates to a vehicle comprising such a duct and / or dashboard.

  The vehicle according to the invention comprises a ventilation unit with an air outlet, at least one vent opening opening towards the interior comprises at least one ventilation device according to the invention, the duct is connected to the aforementioned air outlet and connected to the vehicle. It becomes an acoustic device to which it belongs.

Other features and advantages of the present invention will become apparent from the following description.
The accompanying drawings are by way of non-limiting example.

  In the embodiment shown in FIG. 1 according to the prior art, the ventilator of a motor vehicle comprises a ventilation unit, the outlet 1 of the ventilation unit sends air along two separate ventilation ducts 2 and the outlet of the ventilation duct 2 Is connected to an air vent grill 4 that opens toward the interior of the vehicle. The duct of this device is set in a conventional manner. These vent holes 4 are provided with means for adjusting the direction and flow rate of air in a known manner.

  Although two central air vents opening toward the interior are shown, the ventilation duct shown is located approximately in the center of the dashboard, not shown.

  According to the present invention, as shown in FIG. 2, each of the two ventilation ducts 2 comprises an air flow pipe 10 and a blind hollow 12, the blind hollow opening 14 being substantially perpendicular to the axis of the pipe. Is located.

  The hollow part 12 is called a blind because the mouth 14 of the hollow part is the only opening of the hollow part.

  The air flow along the pipe is represented by arrows 16.

  In the illustrated exemplary embodiment, the two ducts 2 are adjacent ducts connected and separated by a common central wall 2A. The pipe 10 is connected by a hollow portion 12, which is a central hollow portion connected and separated by the central wall 2A.

  The duct 2 includes an inlet 20 that is delimited by a free end of the first portion 22 on the upstream side that runs in the first direction. The duct 2 also comprises a downstream second part 24, in which the pipe 10 runs in the second direction. The duct includes a downstream third portion 26 that runs in the third direction. The free end of the third portion 26 delimits an air outlet that connects to the grill 4 of the vent 4.

  According to an advantageous embodiment of the present invention, the hollow mouth 14 is located between the right vertical lateral wall 24A, the left vertical lateral wall 24B and the two horizontal walls 2B at the top and bottom of the duct 2. Located in two portions 24. The left vertical horizontal wall 24B is a part of the central wall 2A. The mouth 14 of the hollow part is located in the second part 24 approximately in the middle along the entire length of the duct 2.

  Considering the configuration of the duct 2, the second part 24 becomes an intermediate part, where the air flow is branched between the first part 22 and the third part 26. The various parts here are angled with respect to one another or offset laterally with respect to one another.

  The lateral walls of the first portion 22 and the third portion 26 located toward the outside are parallel to the central wall 2A, similar to the wall that divides the pipe 10 in the lateral direction at the inner third portion. The air flow along the first and third portions is thus substantially parallel to the central wall 2A.

  The hollow portion 12 is delimited by the peripheral wall of the duct, in this case by the walls 2A and 2B, and by the partition 30 inside the duct. The internal partition 30 is positioned substantially in the vertical direction in the direction in which air flows along the second portion 24 and along the third portion. The partition 30 partitions the pipe 10 between the hollow portion and the second and third portions 24 and 26. The upstream section of the partition 30 is parallel to the lateral wall 24A in the second section, and the downstream section of the partition 30 is parallel to the central wall 2A in the third section.

  The hollow mouth 14 is advantageous because it is substantially perpendicular to the air flow along the pipe 10. In this case, the hollow port 14 faces the air flow along the first portion 22. The hollow portion is substantially an extension of the aforementioned flow.

  The advantage is that there are no noticeable obstacles in terms of pressure drop or flow rate as a result of the presence of the hollow port 14 and the hollow portion 12.

  The configuration of FIG. 2 reduces noise in units of 1-2 dB at frequencies above 1800 Hz compared to configurations with adjacent ducts separated from each other in a closed hollow, ie, without a hollow mouth. .

  The cross section of the hollow port 14 between the walls 30 and 24B is smaller than half the cross section of the pipe 10 aligned with the hollow port between the lateral walls 24A and 24B. The cross section of the mouth of the hollow part is smaller than half of the cross section of the air flow along the duct along with the mouth of the hollow part, considering that there is no air flow in the hollow part. On the other hand, the sound wave can move through the hollow portion.

  In the second embodiment of FIG. 3, the hollow portion has a throat portion 40 connected to the mouth 14 of the hollow portion. The presence of the throat 40 is parallel to the lateral wall of the duct 2 of the first part at the entrance of the duct 2, in this case parallel to the wall 2 </ b> A, in the direction of the air flow substantially along the first part 22. This is due to the presence of an extension of the wall 30. The cross section of the throat 40 is smaller than the cross section of the remaining portion 12 of the hollow portion. The throat 40 and the hollow part 12 here form a Helmholtz resonator.

  The embodiment of FIG. 3 is more particularly effective in the case of adjacent ducts separated by closed hollows, i.e. without a hollow mouth, when processing noise in a predetermined frequency band, for example 2000 Hz. It is.

  The presence of the hollow port 14 and the hollow portion 12 does not disturb the air flow along the pipe 10. Only the propagation of sound waves along the pipe 10 is disturbed.

  In particular, from an acoustic point of view, sound waves traveling along each ventilation duct encounter cross-sectional variations at the mouth 14 of the hollow portion, thereby causing an impedance blockage that disturbs the sound waves emitted from the ventilation unit. , Noise can be reduced.

  The partition 30 inside the duct is advantageous because it serves as a reinforcement for the duct.

  This is advantageous because the hollow is delimited by the peripheral wall of the duct, which is a duct fixing wall that cooperates with the vehicle components, for example the dashboard structural parts.

  In one embodiment of the present invention, the hollow portion 12 is molded with the pipe 10 as an integral plastic part, and the duct is formed from two half shells, a top and a bottom.

  The ventilator of the illustrated embodiment includes two ducts. In an alternative embodiment, the device may comprise one single duct or more than one duct.

FIG. 2 is a perspective view of a ventilator of conventional design, showing the top of two separate ventilation ducts. It is sectional drawing in the vertical direction of 1st Embodiment of the ventilation apparatus by this invention. It is sectional drawing in the vertical direction of 2nd Embodiment of the ventilation apparatus by this invention.

Claims (11)

  Ventilation of an automobile with at least one ventilation duct (2) connected on the one hand to a ventilation unit (1) for sending air to the duct and on the other hand to a vent (4) opening towards the interior of the vehicle A device, wherein the duct (2) comprises an air flow pipe (10) and a blind hollow (12), the blind hollow opening (14) being located substantially perpendicular to the axis of the pipe. A vehicle ventilator characterized by facing the air flow along the pipe upstream of the mouth of the hollow.   The duct (2) includes an upstream first portion (22) in the first direction and a downstream second portion (24) in which the pipe (10) runs in the second direction, and the opening of the hollow portion. Ventilation according to claim 1, characterized in that (14) is located in the second part, such that the mouth of the hollow part is located substantially on the extension of the pipe (10) in the first part (22). apparatus.   The duct (2) comprises a third part (26) downstream in the third direction, the second part (24) being an intermediate part, where the air flow is directed to the first part (22) and the third part ( 26) The ventilating device according to claim 2, wherein the ventilating device branches off from 26).   4. Ventilation device according to any one of claims 1 to 3, characterized in that the cross-section of the hollow port (14) is smaller than half the cross-section of the pipe (10) aligned with the hollow port.   The hollow part (12) comprises a throat part (40) connected to the mouth (14) of the hollow part, wherein the cross section of the throat part is smaller than the cross section of the remaining part of the hollow part. The ventilation apparatus of any one of.   The hollow portion (12) is partitioned by the peripheral walls (2A, 24A, 2B) of the duct and the partition (30) inside the duct (2), and the interior partition is positioned substantially in the vertical direction in the direction of air flow. 6. Ventilation device according to any one of claims 1 to 5, characterized in that it is a wall that delimits the pipe (10).   The hollow portion (12) and the pipe (10) are partitioned by the peripheral walls (2A, 24A, 2B) of the duct (2) and the partition (30) inside the duct, and the partition inside becomes a reinforcing material for the duct. The ventilation apparatus according to any one of claims 1 to 6, wherein the ventilation apparatus is characterized.   Two ducts (2) are provided, the hollow part (12) of at least one duct connects the pipe (10) of the duct to the pipe (10) of the other duct, and the hollow part (12) is the center of the pipe The ventilator according to any one of claims 1 to 7, characterized in that   The hollow part (12) is delimited by the peripheral walls (2A, 24A, 2B) of the duct (2), which is a duct fixing wall that cooperates with the components of the vehicle. The ventilator according to any one of 8.   A dashboard of a vehicle comprising at least one central air vent (4) opening towards the interior, comprising at least one ventilation device according to any one of the preceding claims, wherein a ventilation duct ( Vehicle dashboard, characterized in that 2) is located approximately in the center of the dashboard and is connected to the vent (4).   10. A vehicle comprising a ventilation unit fitted with an air outlet (1) and at least one vent (4) opened inward, wherein at least one ventilation according to any one of claims 1-9. Vehicle, comprising a device or a dashboard according to claim 10, characterized in that the duct is an acoustic device connected to the air outlet (1) and belonging to the vehicle.

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