JP2003104045A - Air conditioning duct structure for air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an air conditioning duct structure for an air conditioner for a vehicle capable of enhancing a sound absorbing rate characteristic of blowing noise to be a sound absorbing object without increasing plate thickness of a sound absorbing member by disposing the sound absorbing member to form a space between an inner wall surface of an air conditioning duct and the sound absorbing member. SOLUTION: The sound absorbing member 22 made of a porous elastic material for damping vibration energy mainly in a high frequency region of blowing noise generated in an air conditioning unit 10 is provided within the air conditioning duct 20. The sound absorbing rate characteristic in a frequency region lower than the high frequency region is enhanced by providing a projectingly providing part 21b projected to the air conditioning duct 20 and disposing the sound absorbing member 22 to form a prescribed space 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioning duct structure for a vehicle air conditioner, and more particularly to a sound absorbing structure for blowing noise generated in an air conditioning unit.

[0002]

2. Description of the Related Art Conventionally, as an air conditioning duct structure of a vehicle air conditioner of this type, a sound absorbing member is generally provided in the air conditioning duct, and it is known that the ventilation noise of the air conditioning air flowing into the air conditioning duct is absorbed. There is. In this conventional device, an air outlet that blows out the temperature-controlled air-conditioning air into the passenger compartment, an air-conditioning unit that forms an air passage and sends temperature-controlled air-conditioning air, and is disposed between the air outlet and the air-conditioning unit. And an air conditioning duct for guiding the conditioned air sent from the air conditioning unit to the air outlet.

In order to absorb the conditioned air flowing in the air-conditioning duct, as shown in FIG. 15 (a), the sound-absorbing member formed on the inner wall surface of the air-conditioning duct 100 by a porous elastic material such as soft urethane foam. 110 is arranged to absorb the blast noise generated by the air conditioning unit.

[0004]

However, the sound absorption characteristics of the sound absorbing member 110 (normal incidence sound absorption coefficient JISA140) are described below.
5), for example, as shown in FIG.
When the order of mm is an intended sound absorbing effect with respect to high frequency range among the sound absorbing target noise _{(2000H Z ~4000H} Z) is obtained, for example, it is radiated from the blower 50
0H _Z ~1000H sound absorption in the low frequency range can not be completely out of order _Z.

In order to increase the sound absorption coefficient in the low frequency range, it is necessary to increase the thickness of the sound absorbing member 110 to about 50 mm. However, since the air conditioning duct arranged in the vehicle is arranged in the instrument panel that houses the instrument panel in the front of the vehicle, downsizing is required and it is difficult to increase the thickness of the sound absorbing member 110. is there.

Therefore, an object of the present invention is made in view of the above point, and by disposing the sound absorbing member so as to form a space between the inner wall surface of the air conditioning duct and the sound absorbing member, the sound absorbing member is provided. An object of the present invention is to provide an air conditioning duct structure for an air conditioning system for a vehicle, which makes it possible to enhance the sound absorption coefficient characteristic of the blowing noise of the sound absorption target without increasing the plate thickness.

[0007]

In order to achieve the above object, the technical means described in claims 1 to 12 is adopted. That is, in the invention according to claim 1, an air conditioning unit (10) that forms an air passage and blows temperature-controlled conditioned air, and an air outlet (30) that is installed in the vehicle and blows conditioned air into the passenger compartment. , The one end of which is arranged on the instrument panel (P) of the vehicle and which is connected to the air conditioning unit (10) and the other end of which is connected to the air outlet (30) so that the air conditioning air blown from the air conditioning unit (10) is blown out ( In the air conditioning duct structure of the vehicle air conditioning system including the air conditioning duct (20) leading to the air conditioning unit (10), the air conditioning duct (20) mainly has a high noise level among the blowing noises of the sound absorption target generated in the air conditioning unit (10). A sound absorbing member (22) made of a porous elastic material for attenuating vibration energy in the frequency domain is provided, and the sound absorbing member (22) is provided in the air conditioning duct (2
0) inner wall surface (21) of the structural member (21) constituting the outer shell
It is characterized in that a predetermined space (25) for attenuating the vibration energy in the frequency region lower than the high frequency region is formed between the d) and d).

According to the first aspect of the present invention, the sound absorbing member (22) and the inner wall surface (21d) of the structural member (21) forming the outer contour of the air conditioning duct (20) have a predetermined space (2).
By arranging so as to form 5), the sound absorbing member (22) can mainly absorb the noise in the high frequency region of the blast noise to be absorbed, and the predetermined space (25) It is possible to absorb noise mainly in a frequency range lower than the high frequency range.

As a result, it is possible to absorb noise in a high frequency range and a frequency range lower than that without increasing the plate thickness of the sound absorbing member (22), and to downsize the air conditioning duct (20) for a vehicle. It is suitable as an air conditioning duct structure.

According to the second aspect of the invention, an air conditioning unit (10) which forms an air passage and blows temperature-controlled conditioned air, and an air outlet (30) which is mounted on the vehicle and blows the conditioned air into the passenger compartment. And an air-conditioning air blown from the air-conditioning unit (10), which is arranged on the instrument panel (P) of the vehicle and has one end connected to the air conditioning unit (10) and the other end connected to the air outlet (30). In an air conditioning duct structure of a vehicle air conditioner including an air conditioning duct (20) leading to (30), an air conditioning unit (20) is provided on a wall surface of the air conditioning duct (20) on which air conditioning air blown from the air conditioning unit (10) collides. The sound absorbing member (22) made of a porous elastic material is provided for mainly attenuating the vibration energy in the high frequency region of the blown noise of the sound absorbing object generated in 10). Sound member (22) is the air conditioning duct (2
0) inner wall surface (21) of the structural member (21) constituting the outer shell
It is characterized in that a predetermined space (25) for attenuating the vibration energy in the frequency region lower than the high frequency region is formed between the d) and d).

According to the second aspect of the present invention, a predetermined space (2) is formed on the back surface of the wall surface of the air conditioning duct (20) where the air flows blown from the air conditioning unit (10) collide with each other at right angles.
By forming 5), it is possible to absorb more noise particularly in the high frequency region and the lower frequency region.
Therefore, the air conditioning duct (20) can be downsized.

According to the third aspect of the invention, the predetermined space (25) is provided with the protruding portion (22b) protruding outside the sound absorbing member (22), and the inner wall surface of the structural member (21) ( 21d) is formed by abutting the protruding portion (22b).

According to the third aspect of the present invention, the sound absorbing member (22) is provided with the protruding portion (22b), and the protruding portion (22) is provided.
By bringing b) into contact with the inner wall surface (21d), a low-cost predetermined space (25) can be formed without requiring a separate component for forming the space (25).

According to the fourth aspect of the invention, the predetermined space (25) is provided with the projecting portion (21b) protruding inside or outside the structural member (21), and the sound absorbing member (2) is provided.
It is characterized in that it is formed by abutting the protruding portion (21b) on 2).

According to the fourth aspect of the present invention, the structural member (21) is provided with the protruding portion (21b), and the protruding portion (21) is provided.
By contacting b) to the sound absorbing member (22), a predetermined space (25) can be formed and the air conditioning duct (2)
Since the rigidity of the structural member (21) forming the outer shell of (0) can be increased, the structural member (21) can be thinned and weighed, which is suitable as a vehicle air conditioning duct structure.

Moreover, by increasing the rigidity of the structural member (21), it is possible to prevent the occurrence of abnormal noise such as cracks due to the blowing noise mainly in the low frequency range.

According to the fifth aspect of the invention, the predetermined space (25) is formed such that the protruding heights of the protruding portions (21b, 22b) are different depending on the frequency region in which the vibration energy is attenuated. It is characterized by that.

According to the fifth aspect of the present invention, by forming the protruding portions (21b, 22b) so that the protruding heights thereof are different, the size of the space (25) is changed to be a sound absorbing object. The frequency domain can be changed. That is, the frequency region of the blast noise generated on the air conditioning unit (10) side is clearly obtained in advance, and the space (25) corresponding to the frequency region of the sound absorption target is provided with the protruding portions (21b, 22b).
It can be formed by changing the protruding height of the.

In the invention according to claim 6, the protruding portion (21
b, 22b) is characterized in that at least two or more predetermined spaces (25) having different protruding heights of the protruding portions (21b, 22b) are formed.

According to the sixth aspect of the present invention, since at least two or more predetermined spaces (25) are formed, one air-conditioning duct (20) produces a plurality of blast noises to be absorbed. Can absorb sound over the frequency range.

According to the invention of claim 7, the protruding portion (21
b) is characterized in that it is formed integrally with the structural member (21).

According to the invention of claim 7, since the projecting portion (21b) is formed integrally with the structural member (21), the space (25) for absorbing sound without increasing the number of parts. ) Can be formed, and the rigidity of the structural member (21) by the protruding portion (21b) can be increased.

In the invention described in claim 8, the projecting portion (21
The structural member (21) integrally formed with b) is characterized by being a structural body formed of a metal material.

According to the invention described in claim 8, since the structural member (21) is a structure formed of a metal material, the rigidity can be increased more than that of the resin material. The described effect is exhibited.

According to the invention of claim 9, the structural member (2
1) is characterized in that the structure is made of a magnesium material.

According to the ninth aspect of the invention, the structural member (2) in which the protruding portion (21b) is integrally formed
In 1), among the mold forming processes, for example, when thixomolding is used, a magnesium material is used as the material, so that the moldability is good and the protruding portion (21b) can be easily integrally formed.

In the invention described in claim 10, the structural member (21) is an air conditioner in which a part of the outer contour is blown from the air conditioning unit (10) by the structural base material (21f) constituting the instrument panel (P). The air-conditioning duct (20) for guiding the wind to the air outlet (30) is configured.

According to the tenth aspect of the present invention, since the structural member (21) is constituted by the structural base material (21f) constituting the instrument panel (P) to constitute the air conditioning duct (20), the number of parts can be reduced. The weight can be reduced and the weight can be reduced.

According to the eleventh aspect of the invention, the sound absorbing member (22) is provided inside the structural base material (21f) outside the air conditioning duct (20) constituted by the structural base material (21f).
Are arranged so that a predetermined space (25) is formed.

According to the eleventh aspect of the present invention, for example, the vibration energy of noise in the engine room is transmitted from the partition plate that is provided in front of the instrument panel (P) of the vehicle and divides the engine room from the vehicle interior. In the present invention, the structure base material (21) outside the air conditioning duct (20), that is, the structural base material (21) of the instrument panel (P) is transmitted through the vehicle interior.
The sound absorbing member (22) also has a predetermined space (25) inside the f).
Since the predetermined space (25) attenuates the vibration energy of the noise in the engine room transmitted from the partition plate, the outer space of the air conditioning duct (20) is formed. The structural base material (2
Because the vibration propagation to 1f) can be reduced, the air conditioning duct (2
It is possible to prevent adverse effects such as resonance on the blowing noise in 0).

The invention according to claim 12 is characterized in that the structural base material (21f) is a structural body made of a magnesium material.

According to the twelfth aspect of the invention, the same effect as described in the eighth and ninth aspects can be obtained.

The reference numerals in parentheses of the above-mentioned means indicate the correspondence with the concrete means of the embodiments described later.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. First, FIG. 3 is a schematic view of a vehicle air conditioner to which an air conditioning duct structure according to the present invention is applied. In a ventilation system for air conditioning the passenger compartment, an air passage is formed and the temperature of the air is adjusted. An air conditioning unit 10 for blowing air, and a plurality of air outlets 30 that are installed in the vehicle and blow out conditioned air into the passenger compartment,
Air-conditioning air sent from the air-conditioning unit 10 is provided in the instrument panel in the vehicle compartment, one end of which is connected to the air-conditioning unit 10 and the other end of which is connected to the air outlet 30, and the air-conditioning air blown from the air-conditioning unit 10
And an air conditioning duct 20 that leads to the.

The air conditioning unit 10 is composed of a blower unit 11 and an air conditioning case 12. Blower unit 1
1 is arranged offset from the center portion of the instrument panel in the vehicle compartment in the vehicle width direction (offset to the left side in the vehicle width direction for right-hand drive vehicles). The blower unit 11 accommodates an inside / outside air switching box 11a for switching and introducing air inside and outside the vehicle and an air blower 11b for blowing air in an upper portion thereof, and either the air inside the vehicle or the air outside the vehicle The air is taken in and blown to the air conditioning case 12.

The air-conditioning case 12 is arranged substantially in the center of the instrument panel. The air conditioning case 12 has a heat exchanger (evaporator) for cooling (not shown).
Also, a heating heat exchanger (heater core) and the like (not shown) are provided to adjust the temperature of the air blown from the blower unit 11.

A blowout mode switching unit (not shown) is provided on the downstream side of the air flow of the heating heat exchanger (heater core). The blowout mode switching unit is for switching the blowout mode into the passenger compartment, and is the center face opening 12a communicating with the center face outlet 31 that blows out the conditioned air whose temperature is adjusted toward the passenger's head in the passenger compartment. , And a side face opening 12b communicating with the side face outlet 32, and a foot opening (not shown) communicating with a foot outlet that blows conditioned air toward the feet of the occupant.
And a defroster opening (not shown) communicating with a defroster outlet that blows air toward the window glass, and a plurality of door means (not shown) for switching these openings are provided. The blowout mode can be selected.

Next, the air conditioning duct 20 which is an essential part of the present invention.
Will be described. Here, the air conditioning duct 20 that guides the conditioned air toward the center face air outlet 31 and the side face air outlet 32 among the air outlets 30 will be described. An air conditioning duct is connected between each of the other air outlets and each of the openings communicating with the air outlet.

One end of the air conditioning duct 20 is connected to a center face outlet 31 provided at the center of the instrument panel in the vehicle width direction and side face outlets 32 provided at both ends of the instrument panel. The other end is connected to a center face opening 12a and a side face opening 12b provided in the air conditioning case 12.

As shown in FIGS. 1 and 2, the air conditioning duct 20 is composed of a structural member 21, a sound absorbing member 22 and a lid member 23 which form an outer shell. Among them, the structural member 21 is formed by thixomolding using a magnesium material.

The structural member 21 is formed in a box shape having a concave cross section, and the center face opening 1 is formed at the center.
2a and the side face opening 12b, a first opening 21a for connecting to the side face opening 12b, a plurality of protruding portions 21b protruding inward on the bottom surface, and a plurality of first fixing portions 21c having round holes.
And are integrally formed by thixomolding.
This thixomolding is a type of molding, and by using a magnesium material as the material, the moldability is improved and the protruding portion 21b can be easily formed.

The sound absorbing member 22 is made of a porous elastic material such as soft urethane foam, and is used as the air conditioning unit 1.
It is for absorbing the blast noise generated at 0, and is attached to the tip surface of the protruding portion 21b.

Next, the lid member 23 is a lid member made of a resin material such as polypropylene, and has a second opening 23a connected to the center face outlet 31 at the center and side walls at both left and right ends. A third opening 23b connected to the face outlet 32 and a plurality of second fixing portions 23c protruding in a rod shape are formed at positions facing the first fixing portion 21c.

Then, as shown in FIG. 2, the air-conditioning duct 20 is formed by inserting the second fixing portion 23c of the lid member 23 into the first fixing portion 21c and then performing heat staking, and the first opening portion is formed. 21a to second and third openings 23a,
A plurality of spaces 25 are formed between the air passage 24 for guiding the conditioned air to the air conditioner 23b and the sound absorbing member 22 and the inner wall surface 21d of the structural member 21.

By the way, in the present invention, the air conditioning unit 10
In order to absorb noise in a relatively high frequency region in the air passage 24 among the blowing noise generated by the sound absorbing member 2
By providing 2 for damping and providing the space 25 described above, noise in the frequency region lower than the high frequency region is attenuated without increasing the plate thickness of the sound absorbing member 22.

As will be described later, by changing the plate thickness of the sound absorbing member 22 and the size of the space 25, it is possible to individually adjust both frequency regions described above and to obtain sound absorption and attenuation in a combined form of both frequency regions. Since it is possible to obtain the frequency region of, the protruding height of the protruding portion 21b can be set in advance.

Next, since the operation of the vehicle air conditioner having the above-mentioned structure is not different from that of the conventional apparatus, the description of the operation is omitted, and the sound absorbing function of the sound absorbing member 22 and the space 25 will be described.

First, the sound absorbing mechanism of the sound absorbing member 22 causes a resonance phenomenon in the sound absorbing member 22 to which the vibration energy of the air compression wave is transmitted, and this resonance energy activates the movement of the molecules constituting the sound absorbing member 22. , It is understood that this kinetic energy is converted into heat energy and dissipated. For example, flexible urethane foams are shown in FIG.
Sound absorption coefficient characteristics shown in (b) (normal incidence sound absorption coefficient JISA14
If the sound absorbing material has a thickness of t10 mm, as in 05),
00H _Z higher than the frequency region is absorbing. In order to absorb sound in a frequency range lower than this frequency, it is necessary to increase the plate thickness of the sound absorbing material.

Therefore, in the present invention, the sound absorbing effect was confirmed by experiments that the space 25 is formed without increasing the plate thickness of the sound absorbing member 22 to absorb the sound over the frequency range of the blast noise. A description will be given based on FIG.

FIG. 4 shows that a sound absorbing material made of soft urethane foam (at a constant t10 mm) is provided in the duct, and the sound absorbing coefficient according to each frequency when the space L is changed to L = 0, 10, 20 mm on the back surface of the sound absorbing material. Characteristics (Normal incident sound absorption coefficient JISA1
405). According to this, by increasing the space L, the sound absorption coefficient on the lower frequency side is higher than when the space L is 0. This has the same effect as increasing the plate thickness of the sound absorbing material.

Therefore, the air-conditioning ducts formed in the sound absorbing material t = 5, the space L = 10 and the sound absorbing material t = 10, the space L = 5 are mounted on the vehicle air conditioner shown in FIG. 3 to absorb sound in each frequency band. The effect is measured. As shown in FIG. 5, the sound absorption effect in the case of OA (overall) was about 1.1 dB, and both had the same numerical value. However, comparing each frequency band, the space L is larger (L = 10)
Sound can be absorbed in the frequency range centered on the lower frequency 1000H _Z with respect to the first frequency range in which sound is mainly absorbed by the sound absorbing member 22, and the smaller the space L (L = 5) is, the higher the first frequency range is. close to the frequency domain frequency 1600H _Z
We were able to absorb sound in the frequency range centered on.

From this result, it was found that the frequency range of sound absorption (second frequency range) can be obtained by changing the space L. Therefore, the air conditioning unit 10 is previously
If the frequency band of the blast noise generated in 1 is clearly obtained, it is possible to absorb noise in the frequency range of the sound absorption target by changing the size of the space 25 and the protrusion height of the protruding portion 21b.

According to the air conditioning duct structure of the vehicle air conditioner of the first embodiment, the sound absorbing member 22 is arranged so that the predetermined space 25 is formed between the sound absorbing member 22 and the inner wall surface 21d of the structural member 21. As a result, the sound absorbing member 22 can mainly absorb the blowing noise in the high frequency region, and the predetermined space 25 can mainly absorb the blowing noise in the lower frequency region than the high frequency region.

As a result, it is possible to absorb the blast noise in the high frequency range and the lower frequency range without increasing the plate thickness of the sound absorbing member 22, and at the same time, the air conditioning duct 20.
Is suitable for a vehicle air conditioning duct structure.

Further, since the projection 21b is integrally provided on the inner wall surface 21d of the structural member 21 to form the predetermined space 25, the rigidity of the air conditioning duct 20 is increased, and the plate thickness of the structural member 21 is reduced. It is suitable for a vehicle air conditioning duct structure because it can be made lighter.

In addition, when the structural member 21 is molded by the thixomolding method among the molding methods, the magnesium material is used for good moldability, and the protruding portion 21b can be easily integrally molded. Therefore, a separate component for forming the space 25 is not required, and the cost can be reduced.

(Second Embodiment) In the first embodiment described above, the space 25 formed in the inner wall of the structural member 21 has been described as having the same protrusion height of the protruding portion 21b. A plurality of spaces 25 different from each other may be formed. As shown in FIG. 6, two protrusion heights L1 and L2 are provided for the protruding portion 21b, and two sizes of the space 25 are formed.

As a result, it is possible to absorb the blast noise in the two types of frequency regions which are the objects of sound absorption. Further, even if the protruding portions 21b having different protruding heights are provided, the integral molding can be easily performed without being affected by the moldability of the structural member 21.

(Third Embodiment) In the above embodiments, the structural member 21 made of the magnesium material and the lid member 23 made of the resin material are assembled after the sound absorbing member 22 is assembled, and then air-conditioned. Although the duct 20 is configured, the present invention is not limited to this, and the present invention is also applied to an air conditioning duct formed integrally by blow molding a resin material such as polypropylene.

That is, as shown in FIGS. 7 (a) and 7 (b), here, the structural member 21e is formed by blow molding.
However, since the sound absorbing member 22 cannot be provided over the entire length, the structural member 21e is formed.
Of the protruding portion 21 protruding outward in the vicinity of the openings at both ends of the
b is integrally formed, and the inner wall surface 21d of the structural member 21e is formed.
The sound absorbing member 22 is arranged so that the space 25 is formed on the side.

As a result, the sound absorbing member 22 and the space 25 are
Thus, it is possible to absorb the blowing noise generated in the air conditioning unit 10. Further, since the structural member 21e is integrally formed, the cost of parts can be reduced.

(Fourth Embodiment) In the above embodiments, the air conditioning duct 20 arranged in the instrument panel installed in the vehicle compartment has been described, but the present invention is not limited to this.
You may form integrally with the structural base material which comprises an instrument panel.

That is, as shown in FIG. 8, the structural member 21 described in the first to third embodiments is replaced with a structural base material 21f constituting the instrument panel P, and the back surface of the instrument panel P is replaced. The projecting portion 21b is formed so as to project on the back surface side of the structural base material 21f disposed on the side, and the sound absorbing member 22 is formed so that the space 25 is formed.
Is provided.

The lid member 23 is formed of a resin material (such as polypropylene), and is joined to the structural base material 21f of the instrument panel P by joining such as ultrasonic joining. As a result, the number of parts can be reduced and the weight can be reduced as compared with the above embodiment.

(Fifth Embodiment) In the above first and second embodiments, the plurality of spaces 25 are formed only on the bottom surface of the air conditioning duct 20, but the present invention is not limited to this, and the air conditioning unit 10 blows air. It is advisable to dispose the sound absorbing member 22 so as to form the space 25 also on the surface where the wind flows collide at right angles. Specifically, as shown in FIG. 9, a sound absorbing member 22 is provided by forming spaces 25 at both ends of a structural member 21 formed in a concave box shape. When the air-conditioning air blown from the air-conditioning unit 10 is guided to the side face outlet 32 through the third opening 23b, the both ends are changed in the upward direction from the horizontal direction. This is the surface on which the wind flow collides.

Therefore, as shown in FIG. 10, a space 25 is formed between the sound absorbing member 22 and the inner wall surface 21d of the structural member 21 on the back surface of the sound absorbing member 22 on this surface, that is, at both ends of the structural member 21. As a result, noise in the high frequency range and the frequency range lower than that can be more absorbed. This allows
The air conditioning duct 20 can be made smaller than in the first and second embodiments. By forming the flange portion 22a protruding outward at the upper end of the sound absorbing member 22, the space 25 can be formed without forming the protruding portion 21b on the vertical surface of the structural member 21.

Further, as shown in FIG. 11, the sound absorbing area is expanded by forming the space 25 and arranging the sound absorbing member 22 on the vertical surface in the vehicle front-rear direction, that is, on all of the concave inner wall surface 21d. , It is possible to absorb more noise in high frequency region and lower frequency region. As a result, the air conditioning duct 20 can be downsized.

(Sixth Embodiment) In the above embodiments, the projecting portion 21b for forming the space 25 is formed integrally with the structural member 21, but not limited to this, the sound absorbing member 22 is provided with the projecting portion 21b. May be provided. Specifically, as shown in FIG. 12, a protruding portion 22b protruding outside the sound absorbing member 22 is integrally formed.

As a result, the protruding portion 21 is provided on the side of the structural member 21.
It can be made lighter than b. In this embodiment, the protruding portion 22b is projected in the shape of a rectangular rib, but it may be divided into a plurality of parts.

(Seventh Embodiment) In the fourth embodiment, the structural member 21 constituting the outer shell of the air conditioning duct 20 is replaced with the structural base material 21f constituting the instrument panel P, and the rear surface of the structural base material 21f is replaced. The sound absorbing member 22 is arranged so as to form the space 25 by projecting the protruding portion 21b on the side, but in the present embodiment, the air conditioning duct 20 is provided.
It is advisable to form the space 25 also on the outer side of the sound absorbing member 22.

Specifically, FIG. 13A and FIG.
As shown in (b), as in the air conditioning duct 20,
Also outside the air conditioning duct 20, a space 25 is formed between the structural base material 21f and the sound absorbing member 22. 13A, the protruding portion 21b is formed on the structural base material 21f, and in FIG. 13B, the protruding portion 22b is formed on the sound absorbing member 22.

Thus, for example, the vibration energy of noise in the engine room is transmitted to the vehicle interior from the partition plate that is provided in front of the instrument panel P of the vehicle and divides the engine room from the vehicle interior. By the space 25 formed in the material 21f, the vibration energy of the noise in the engine room transmitted from the partition plate is attenuated, so that the structural base material 21 that forms the outer shell of the air conditioning duct 20.
Since vibration propagation to f can be reduced, adverse effects such as resonance can be prevented with respect to the blowing noise in the air conditioning duct 20.

(Other Embodiments) In the first and second embodiments, the structural member 21 is integrally formed by thixomolding using a magnesium material, but the present invention is not limited to this.
The structure may be formed using a metal material such as an aluminum alloy or iron or a resin material such as polypropylene with glass.

In the above embodiment, the structural member 21 is used.
And a protruding portion 21b formed integrally with the structural base material 21f.
14 is formed in the shape of a rectangular rib, the present invention is not limited to this.
As shown in, a plurality of substantially cylindrical protruding portions 21b may be formed. The shape of the protruding portion 21b is not limited to this shape.

[Brief description of drawings]

FIG. 1 is an air conditioning duct 20 according to a first embodiment of the present invention.
FIG. 3 is an exploded perspective view showing the overall configuration of FIG.

FIG. 2 is a front view showing a main configuration of an air conditioning duct 20 shown in FIG.

FIG. 3 is a schematic diagram showing a mounting form of an air conditioning duct structure of the vehicle air conditioning device in the first embodiment of the present invention.

FIG. 4 is an air conditioning duct 20 according to the first embodiment of the present invention.
It is a characteristic view showing a sound absorption coefficient characteristic of.

FIG. 5 is an air conditioning duct 20 according to the first embodiment of the present invention.
It is a characteristic view showing the sound absorption effect of.

FIG. 6 is an air conditioning duct 20 according to a second embodiment of the present invention.
3 is a partial cross-sectional view showing the configuration of FIG.

FIG. 7A is a perspective view showing a configuration of an air conditioning duct 20 according to the third embodiment of the present invention, and FIG. 7B is an air conditioning duct 20.
FIG. 3 is a side view and a plan view showing the configuration of FIG. FIG.

FIG. 8 is an air conditioning duct 20 according to a fourth embodiment of the present invention.
It is a longitudinal cross-sectional view showing the configuration of.

FIG. 9 is a schematic view showing a mounting form of an air conditioning duct structure of a vehicle air conditioner according to a fifth embodiment of the present invention.

10 is a partial cross-sectional view showing the main configuration of the air conditioning duct 20 shown in FIG.

11 is a view on arrow A showing the main configuration of the air conditioning duct 20 shown in FIG.

FIG. 12 is an air conditioning duct 2 according to a sixth embodiment of the present invention.
It is a fragmentary sectional view which shows the principal part structure of 0.

13 (a) and 13 (b) are vertical cross-sectional views showing the configuration of an instrument panel P according to a seventh embodiment of the present invention.

FIG. 14 is a perspective view showing a configuration of a structural member 21 according to another embodiment.

FIG. 15A is a vertical cross-sectional view showing the configuration of an air conditioning duct, and FIG. 15B is a characteristic diagram showing sound absorption coefficient characteristics of a sound absorbing material in the prior art.

[Explanation of symbols]

10 ... Air conditioning unit 20 ... Air conditioning duct 21 ... Structural member 21b ... protruding portion 21d ... Inner wall surface 21f ... Structural base material 22 ... Sound absorbing member 22b ... protruding portion 25 ... space 30 ... Outlet P ... Instrument panel

Continued front page    (72) Inventor Koichi Ito             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO (72) Inventor Seifumi Kawashima             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO F-term (reference) 3L011 BR00                 3L080 AD01 AE02

Claims (12)

[Claims] 1. An air conditioning unit (10) which forms an air passage and blows conditioned air whose temperature is adjusted, and an air outlet (30) which is installed in a vehicle and blows conditioned air into a passenger compartment.
The conditioned air blown from the air conditioning unit (10) is arranged on the instrument panel (P) of the vehicle and has one end connected to the air conditioning unit (10) and the other end connected to the air outlet (30). In an air conditioning duct structure of a vehicle air conditioner, comprising an air conditioning duct (20) leading to an outlet (30), the air conditioning unit (1) is provided in the air conditioning duct (20).
The sound absorbing member (22) made of a porous elastic material for mainly attenuating the vibration energy in the high frequency region of the blowing noise of the sound absorbing object generated in 0) is provided, and
A predetermined distance between the sound absorbing member (22) and the inner wall surface (21d) of the structural member (21) forming the outer shell of the air conditioning duct (20) for damping vibration energy in a frequency region lower than the high frequency region. The air conditioning duct structure for a vehicle air conditioner, characterized in that the space (25) is formed. 2. An air conditioning unit (10) which forms an air passage and blows temperature-controlled conditioned air, and an air outlet (30) which is mounted on a vehicle and blows the conditioned air into a vehicle interior.
The conditioned air blown from the air conditioning unit (10) is arranged on the instrument panel (P) of the vehicle and has one end connected to the air conditioning unit (10) and the other end connected to the air outlet (30). In an air conditioning duct structure of a vehicle air conditioner including an air conditioning duct (20) leading to an outlet (30), a wall surface of the air conditioning duct (20) on which air conditioning air blown from the air conditioning unit (10) collides. A sound absorbing member (22) made of a porous elastic material is provided for mainly attenuating vibration energy in a high frequency region of the blowing noise of the sound absorbing object generated in the air conditioning unit (10), and the sound absorbing member is also provided. (22) is the air conditioning duct (2
0) inner wall surface (21) of the structural member (21) constituting the outer shell
An air conditioning duct for a vehicle air conditioner, characterized in that a predetermined space (25) for attenuating vibration energy in a frequency region lower than a high frequency region is formed between the air conditioning duct and the d). Construction. 3. The predetermined space (25) is provided with a projecting portion (22b) protruding outside the sound absorbing member (22), and the inner wall surface (21d) of the structural member (21) is provided with the projecting portion (22b). The air-conditioning duct structure for a vehicle air-conditioning system according to claim 1 or 2, wherein the protruding portion (22b) is formed by being brought into contact with the protruding portion (22b). 4. The projection (2) projecting inward or outward of the structural member (21) is provided in the predetermined space (25).
1b) is provided, and is formed by abutting the projecting portion (21b) on the sound absorbing member (22). Air conditioning duct structure. 5. The protrusion (21) is provided in the predetermined space (25) according to a frequency range in which vibration energy is attenuated.
5. The air conditioning duct structure for a vehicle air conditioner according to claim 1, wherein the protruding heights of b and 22b) are different from each other. 6. The projections (21b, 22b) are formed with at least two or more predetermined spaces (25) having different projection heights of the projections (21b, 22b). An air conditioning duct structure for a vehicle air conditioner according to claim 5, wherein: 7. The vehicle air conditioner according to claim 4, wherein the protruding portion (21b) is formed integrally with the structural member (21). Air conditioning duct structure of the device. 8. The vehicle air conditioner according to claim 7, wherein the structural member (21) integrally formed with the protruding portion (21b) is a structural body formed of a metal material. Air conditioning duct structure. 9. The structure member (21) is a structure body made of a magnesium material.
The air conditioning duct structure of the vehicle air conditioner according to. 10. The structural member (21) blows the conditioned air blown from the air conditioning unit (10) by a structural base material (21f) constituting a part of an outer shell of the instrument panel (P). The air conditioning duct structure for a vehicle air conditioner according to any one of claims 1 to 4, characterized in that the air conditioning duct (20) leading to the outlet (30) is configured. 11. The sound absorbing member (22) has a predetermined space (25) inside the structural base material (21f) outside the air conditioning duct (20) constituted by the structural base material (21f). The air-conditioning duct structure for a vehicle air-conditioning system according to claim 10, wherein the air-conditioning duct structure is arranged so as to form a structure. 12. The air conditioning duct structure for a vehicle air conditioner according to claim 11, wherein the structural base material (21f) is a structure formed of a magnesium material.