JP2006123659A - Vent duct for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vent duct for a vehicle which suppresses noise of a broad range of frequency band entered from the outside of a car and does not prevent air exhaustion. <P>SOLUTION: The vent duct 1 for the vehicle has a communication chamber through which air from a chamber passes, a vent for exhausting the air in the chamber, a valve element for openably/closably covering the vent, and a noise absorbing chamber arranged in a surface facing the vent. A communication port passing through the inside of the chamber and the communication chamber is formed in a side wall surface sectioning the communication chamber. The noise absorbing chamber has a permeation port projecting into the communication chamber and the permeation port is covered with a ventilating member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle vent duct that guides air in a vehicle interior to the outside of the vehicle.

  A vehicle vent duct (hereinafter, abbreviated as a “vent duct” as appropriate) is provided in the vehicle as one of the ventilation devices that guides the air in the vehicle interior to the outside of the vehicle. The vent duct is provided with a vent hole covered with a valve body that opens and closes outwardly from the vehicle. The vent hole communicates between the interior of the vehicle and the outside of the vehicle. For example, when air flows into the passenger compartment by opening or closing a door, air having the same volume as the air that has flowed in opens the valve body. The air that has pushed the valve body open is led out of the vehicle through the vent.

  However, when the valve body is opened, noise such as road noise, pattern noise, and brake noise will enter the vehicle interior from outside the vehicle through the vent.

  Therefore, Patent Document 1 discloses a vent duct composed of a duct body and a sound absorbing chamber as a first conventional technique. FIG. 4 shows a perspective view of the vent duct described in the document. According to the present invention, the sound absorbing material 30 is provided on the bottom surface portion 31 of the sound absorbing chamber portion 3 facing the air outlet 20 where the transmitted sound from the outside of the vehicle directly strikes, and the transmitted sound from the outside of the vehicle is absorbed by the sound absorbing material.

As a second prior art, Patent Document 2 introduces a vent duct having a resonance device attached thereto. FIG. 5 shows a cross-sectional view of the vent duct described in the document. As shown in FIG. 5, the vent duct 100 includes a duct main body 101, a seat valve body 102, and a resonance device 103. The noise enters the resonance chamber 105 of the resonance device 103 through the small hole 104 as indicated by a white arrow in the figure. In the resonance chamber 105, the sound pressure in the frequency region near 63 Hz is suppressed among the noise by the Helmholtz resonance theory.
JP 2002-172927 A JP 2003-182344 A

  However, the vent duct described in the above-described prior art has the following problems. In the vent duct described in Patent Literature 1, when the transmitted sound that has entered from the air outlet 20 collides with the sound absorbing material 30, the noise energy is converted into thermal energy by friction and the transmitted sound is absorbed. Furthermore, the transmitted sound reflected by the sound absorbing material 30 repeats re-reflection / collision in the vent duct and gradually absorbs the transmitted sound. However, the energy amount and frequency of transmitted sound are not constant, and sound absorption with only a sound absorbing material can provide only a monotonous sound absorbing effect. In addition, repeated reflection and collision between the sound absorbing material and the vent duct could not be said to achieve sound absorption efficiently. There are various types of noise entering from outside the passenger compartment, and it is necessary to exert an effect on noises in a wide range of frequencies.

  In the case of the vent duct 100 described in Patent Document 2, the sound pressure can be suppressed only in a narrow frequency range to which the Helmholtz resonance theory is applied. For this reason, when suppressing the sound pressure of the frequency range over a comparatively wide range, it is necessary to arrange | position the several resonance apparatus from which the frequency range used as suppression object differs, respectively. Therefore, the vent duct 100 is increased in size.

  The vent duct for vehicles of the present invention has been completed in view of the above problems. Accordingly, an object of the present invention is to provide a vehicle vent duct that can efficiently absorb various transmitted sounds.

(1) A communication chamber through which air from the vehicle interior can pass, a vent provided outside the communication chamber for exhausting vehicle interior air, a valve body for opening and closing the vent, and the communication In the vehicle vent duct provided on the vehicle interior side of the room and having a sound absorbing chamber disposed on a surface facing the vent hole,
The communication chamber has a side wall surface defining the communication chamber in the vehicle front-rear direction, and the side wall surface is provided with a communication port penetrating the vehicle interior and the communication chamber,
The sound absorbing chamber has a transmission port protruding into the communication chamber, and the transmission port is covered with a breathable member.

That is, the vent duct of the present invention includes a communication chamber and a sound absorption chamber. A communication port is provided in the communication room. Further, the transmission port of the sound absorption chamber protrudes into the communication chamber. The permeation port is covered with a breathable member to partition the communication chamber and the sound absorption chamber. Noise that enters from the outside of the vehicle through the vent enters the sound absorbing chamber from the communication chamber via the breathable member. When noise enters the breathable member, the air in the breathable member first vibrates. Next, noise energy is converted into heat energy by the viscosity of air. For this reason, the energy of noise becomes small. The noise that has passed through the breathable member propagates through the air layer in the sound absorbing chamber, collides with the wall surface that defines the sound absorbing chamber, and is reflected. These propagation and reflection reduce the energy of noise. The reflected noise returns from the sound absorption chamber to the communication chamber again through the air-permeable member. At this time, the energy of the reflected noise is again absorbed by the breathable member. Further, noise energy is attenuated by the phase difference between the reflected sound and the incident sound. In particular, when the reflected sound and the incoming sound insulation are in opposite phases, the energy attenuation increases. Thus, according to the vehicle vent duct of the present invention, the noise passes through the breathable member, propagates through the sound absorbing chamber, and is reflected, whereby the sound pressure of the noise can be suppressed. That is, noise can be absorbed by two-stage energy conversion means, that is, energy conversion by air vibration in the air-permeable member and energy conversion by air propagation / reflection in the sound absorption chamber. For this reason, it is possible to efficiently suppress the sound pressure in a wide frequency range as compared with the case of the conventional arrangement of the sound absorbing material alone and the case of the arrangement of the resonance device alone.
In addition, according to the vehicle vent duct of the present application, the volume of the sound absorbing chamber can be increased by providing the sound transmitting chamber through the communication port. Here, the position where the vent duct is attached is determined by the vehicle-side requirements, and the size and depth of the communication chamber are limited. It is known that the sound absorbing effect is improved as the volume of the sound absorbing chamber, that is, the back air layer of the air-permeable member is larger. However, in order to secure a large volume of the back air layer, the depth of the communication chamber is inevitably reduced when the sound absorbing chamber is protruded from the back surface of the opposing wall surface toward the vehicle interior side. The side wall of the communication room has a communication port that is a passage for air inside and outside the vehicle interior. If the depth of the communication room is narrowed, it becomes difficult to increase the opening area of the communication port and the air outflow efficiency decreases. Resulting in. Further, since the depth of the communication chamber is reduced, the distance from the opposing wall surface to the vent is narrowed, and the opposing wall surface hinders the derived air, and there is a risk that the air outflow efficiency is similarly reduced. That is, the vehicular vent duct of the present invention can secure the air outflow amount while having a sound absorbing effect. The sound absorbing chamber is disposed on the vehicle inner side than the valve body. Further, the permeation port is blocked by a breathable member. For this reason, there is little possibility that raindrops, dust, mud and the like enter the sound absorption chamber. Therefore, the vehicle vent duct of the present invention has high operational reliability.

  (2) Preferably, it is more preferable that the sound absorbing chamber is disposed on an opposing wall surface facing the vent and protrudes further toward the vehicle interior side from the opposing wall surface. By projecting toward the vehicle interior side from the opposing wall surface, the volume of the sound absorbing chamber can be increased, and a large amount of the back side air layer of the breathable member can be secured. As described above, the sound absorption effect due to the propagation of air can be enhanced as the amount of air increases, and the optimal value of the amount of protrusion and the depth of the communicating portion can be appropriately set depending on the vehicle to which the vent duct is attached. it can.

  (3) Preferably, in the configuration of the above (1) or (2), the opposing wall surface is provided with a through-hole that penetrates the communication chamber and the vehicle interior side. By providing the through hole, air can be efficiently discharged from the vehicle interior side.

  (4) Preferably, in the configuration of (3) above, the through-hole is preferably provided with a louver extending downward from above toward the vehicle interior side. It is possible to prevent noise from outside the vehicle compartment that has not entered the sound absorbing chamber from colliding with and reflected by the louver, reducing noise energy, and entering the vehicle interior. Therefore, the noise suppression effect is enhanced.

  According to the present invention, it is possible to provide a vent duct for a vehicle that can exhibit a large sound absorption effect with respect to various noises and has high air derivation efficiency.

  Hereinafter, embodiments of a vehicle vent duct according to the present invention will be described.

(1) First Embodiment First, the configuration of the vent duct of this embodiment will be described. In FIG. 1, the disassembled perspective view of the vent duct of this embodiment is shown. FIG. 2 shows a cross-sectional view of the vent duct. As shown in these drawings, the vent duct 1 includes a duct body 2 and a housing 3. The duct body 2 is embedded in a rectangular duct attachment port 90 opened in the quarter panel 9. The quarter panel 9 is included in the outer shell of the present invention. The duct body 2 includes a frame body 20 and seat valve bodies 21a and 21b. The seat valve bodies 21a and 21b are both included in the valve body of the present invention. The frame 20 is made of resin and has a rectangular tube shape. A partition wall 200 extending in the horizontal direction is disposed at the center of the frame 20 in the vertical direction. A rectangular vent 201a is opened above the partition wall 200. In addition, a rectangular vent 201b is also opened below the partition wall 200. A valve body locking projection 202a is projected from the upper edge of the vent 201a on the vehicle exterior side. Similarly, a valve body locking projection 202b is projected from the upper edge of the vent hole 201b outside the vehicle.

  The seat valve body 21a is made of rubber and has a rectangular plate shape. An engagement hole 210a is formed in the upper edge of the seat valve body 21a. The valve body locking projection 202a is inserted and locked in the engagement hole 210a, so that the seat valve body 21a covers the vent hole 201a so as to be opened and closed. Similarly, the seat valve body 21b is made of rubber and has a rectangular plate shape. An engagement hole 210b is formed in the upper edge of the seat valve body 21b. The valve body locking projection 202b is inserted and locked in the engagement hole 210b, whereby the seat valve body 21b covers the vent hole 201b so as to be opened and closed.

  The housing 3 is made of resin and opens toward the duct main body 2, and is a box in which a facing wall surface 300 a is formed on a surface facing the vent holes 201 a and 201 b and a side wall surface 300 b is formed in a direction intersecting the vent hole. It has a shape. The communication chamber 304 of the present invention is configured to be surrounded by the duct body 2 and the inner wall of the housing 3. A part of the opposing wall surface 300a is cut open, and a box-shaped recess 301 having a transmission port 302 whose opening edge protrudes to the outside of the vehicle is provided. The bottom surface of the recess 301 protrudes toward the vehicle inner side of the opposing wall surface 300a. The permeation port 302 is covered with a breathable member 31 from the outside of the vehicle. Furthermore, a through-hole 307 having a louver 306 is provided in the facing wall surface 300a.

  The breathable member 31 is made of open-cell sponge and has a rectangular plate shape. The sound absorption chamber 303 is disposed so as to be surrounded by the air-permeable member 31 and the recess 301 that cover the transmission port 302. The communication chamber 304 and the sound absorption chamber 303 are partitioned by the air permeable member 31. That is, the volume of the back air layer of the air-permeable member 31 is set large by the permeation port 302 projecting into the communication chamber 304 and forming the sound absorption chamber 303. A rectangular communication port 305 is formed in the side wall surface 300 b of the housing 3 that defines the communication chamber 304. The communication room 304 communicates with the vehicle interior (not shown) through the communication port 305.

  Next, the movement of the vent duct of this embodiment will be described. For example, when air flows into the vehicle interior by opening or closing a door, air having the same volume as the air that flows in flows into the communication chamber 304 from the communication port 305. The inflowing air pushes the seat valve bodies 21a and 21b open. The air that has pushed the seat valve bodies 21a and 21b open is led out of the vehicle through the vent holes 201a and 201b.

  Here, when the seat valve bodies 21a and 21b are opened, noise such as road noise, pattern noise, and brake noise flows into the communication chamber 304 from the outside of the vehicle via the vent holes 201a and 201b. The noise is directly or indirectly reflected by the wall section that defines the communication chamber 304 and indirectly enters the sound absorbing chamber 303 through the air-permeable member 31 as indicated by the white arrow in FIG. Since the transmission port 302 is provided so as to protrude into the communication chamber 304, the volume of the sound absorbing chamber 301 is larger by the amount of the protrusion. The noise incident from the transmission port 302 propagates through the air layer in the sound absorption chamber 303, is reflected by the wall portion that defines the sound absorption chamber 303, and enters the communication chamber 304 again through the air-permeable member 31. The noise that has entered the communication chamber 304 is introduced into the vehicle interior via the communication port 305. Alternatively, noise is released outside the vehicle through the vents 201a and 201b.

Next, the effect of the vent duct of this embodiment will be described. According to the vent duct 1 of the present embodiment, noise from the outside of the vehicle enters the sound absorbing chamber 303 from the communication chamber 304 via the breathable member 31. The energy of the incident noise is absorbed by the air-permeable member 31, and the noise is reduced. Furthermore, the noise that has passed through the air-permeable member 31 propagates through the air layer in the sound absorbing chamber 303, collides with the wall surface that defines the sound absorbing chamber 303, and is reflected. The noise energy is attenuated by repeated propagation and reflection. Further, noise energy is attenuated by the phase difference between the reflected sound and the incident sound. The reflected noise returns from the sound absorption chamber 303 to the communication chamber 304 via the air-permeable member 31 again. At this time, the energy of the reflected noise is absorbed by the air-permeable member 31 again.
Here, in the vehicle vent duct according to the first embodiment, since the permeation port 302 protrudes into the communication chamber 304, the volume of the air layer in the sound absorption chamber 303 is increased by the amount of protrusion. The greater the amount of air that propagates, the greater the attenuation of noise energy. That is, according to this configuration, it is possible to secure a larger amount of energy attenuation due to propagation by the amount of air layer protruding into the communication chamber 304. The size of the portion where the vent duct is attached is limited by the vehicle requirements. If the volume of the sound absorbing chamber 303 is greatly increased toward the inside of the vehicle in order to increase the volume, the depth of the housing 3 is inevitably shallow. Here, when the depth of the housing 3 becomes shallow, it becomes difficult to widen the opening of the communication port 305 provided in the side wall surface 300b, and the amount of air outflow from the communication port 305 decreases. As described above, according to the vehicle vent duct 1 of the present embodiment, since the air layer on the back side of the air-permeable member 302 is large, the sound absorption effect by the propagation of the air layer is high, and the opening area of the communication port 305 is ensured to be wide. It is also possible to prevent a decrease in the amount of outflow.

  Further, in the vehicle vent duct 1 of the present embodiment, a through hole 307 is opened below the opposing wall surface 300a. The through hole 307 has a slit shape extending in the lateral direction (front and back direction in the drawing). The through holes 307 are arranged in two rows in the vertical direction. A louver 306 that curves downward is integrally formed from the upper edge of each through-hole 307 on the company room side. Of the noise energy incident from the outside of the vehicle, the energy that could not be incident into the sound absorbing chamber 303 collides with the louver 306. This collision attenuates noise energy. Therefore, the noise suppression effect is further high.

  Moreover, the air permeable member 31 of this embodiment is arrange | positioned facing the vent holes 201a and 201b through which noise passes. Also in this respect, most of the noise that has entered the communication chamber 304 can be introduced into the sound absorption chamber 303 instead of the vehicle interior. Therefore, the noise suppression effect is high.

(2) Second Embodiment FIG. 3 shows a cross-sectional view of the vent duct of this embodiment. In addition, about the site | part corresponding to FIG. 1, FIG. 2, it shows with the same code | symbol. The difference between the present embodiment and the first embodiment is that the bottom surface of the sound absorbing chamber 303 does not protrude from the opposing wall surface 300a toward the vehicle interior, and is flush with the back surface of the opposing wall surface 300a.

  The vent duct of this embodiment is effective when the attachment site is narrow and the depth of the housing 3 cannot be taken deep. Moreover, it has the same effect as the vent duct of the first embodiment.

(3) Others The embodiment of the vent duct of the present invention has been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  For example, in the above-described embodiment, the concave portion 301 is disposed on the facing wall 300, but the concave portion 301 may be disposed on the upper wall, the lower wall, and the side wall.

  Moreover, in the said embodiment, although the air permeable member 31 made from open-cell sponge was arrange | positioned, the kind of air permeable member 31 is not specifically limited. Various nonwoven fabrics, woven fabrics, perforated plates and the like can be used.

It is a disassembled perspective view of the vent duct of 1st embodiment. It is sectional drawing of the vent duct. It is sectional drawing of the vent duct of 2nd embodiment. It is a disassembled perspective view of the 1st conventional vent duct. It is sectional drawing of the 2nd conventional vent duct.

Explanation of symbols

  1: vent duct, 2: duct body, 20: frame, 200: partition wall, 201a: vent, 201b: vent, 202a: valve body locking projection, 202b: valve body locking projection, 21a: seat valve body (Valve element), 21b: seat valve element (valve element), 210a: engagement hole, 210b: engagement hole, 3: housing, 300a: opposing wall surface, 300b: side wall surface, 301: recess, 302: transmission port, 303: Sound absorption chamber, 304: Communication chamber, 305: Communication port, 306: Louver, 307: Through port, 31: Breathable member, 9: Quarter panel (vehicle outer), 90: Duct mounting port.

Claims (4)

A communication chamber through which air from the vehicle interior can pass; a vent provided outside the communication chamber for exhausting the vehicle interior air; a valve body for opening and closing the vent; and a vehicle in the communication chamber In the vehicle vent duct provided on the indoor side and having a sound absorbing chamber disposed on the surface facing the vent,
The communication chamber has a side wall surface defining the communication chamber in the vehicle front-rear direction, and the side wall surface is provided with a communication port penetrating the vehicle interior and the communication chamber,
The vehicle vent duct, wherein the sound absorbing chamber has a transmission port protruding into the communication chamber, and the transmission port is covered with a breathable member.   2. The vehicle vent duct according to claim 1, wherein the sound absorbing chamber is provided on an opposing wall surface facing the vent hole, and further protrudes toward a vehicle interior side from a back surface of the opposing wall surface. The vent duct for a vehicle according to claim 1 or 2, wherein a through-hole that penetrates the communication chamber and the vehicle interior side is provided in the opposing wall surface.   The vehicle vent duct according to claim 3, wherein a louver extending from above to below is provided in the through-hole toward the vehicle interior side.

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