Outdoor food

Abstract

To enhance the sound absorption effect in an air passage inside an outdoor hood while suppressing an increase in thickness of a sound absorption material.SOLUTION: A rear plate 10 having a through hole at the position of an exhaust port opening in an outer wall of a building is fixed along a wall surface of the outer wall, and a front plate 20a is arranged at a position facing the rear plate with an air passage 6 therebetween, so that exhaust gas discharged from the exhaust port is guided to the air outlet through the air passage. Sound absorbing materials 14 and 23 which absorb noise transmitted through the air passage are laid on the air passage side surfaces of the rear plate and the front plate. These sound absorbing materials are constructed by overlapping inner sound absorbing materials 14b, 23a disposed on the air passage side and outer sound absorbing materials 14c, 23b disposed on the opposite side to the air passage. When comparing the inner sound absorbing materials and the outer sound absorbing materials, the inner sound absorbing materials have higher absorption performance for absorbing noise, and the outer sound absorbing materials have higher reflective performance for reflecting noise.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an outdoor hood installed to cover an exhaust port of a duct that opens to the outer wall of a building.

Background Art

[0002] In order to prevent rain and wind from entering the exhaust port of a duct that opens to the outer wall of a building, an outdoor hood installed to cover the exhaust port is known. An air passage is formed inside the outdoor hood, and the exhaust discharged from the exhaust port is guided along the air passage and blown out from the blowout port.

[0003] In such an outdoor hood, noise may leak from the inside of the building to the outside through the duct or the air passage. For example, when noise occurs in equipment such as a clothes dryer or a heater connected to the upstream side of the duct, it will leak out from the blowout port by traveling through the duct or the air passage together with the exhaust. Conversely, outdoor noise may also reach the inside of the building through the blowout port, the air passage, and the duct. Therefore, it has been proposed to lay a sound-absorbing material on the inner surface of the outdoor hood (for example, Patent Document 1), and the noise traveling through the air passage inside the sound-absorbing material can be absorbed and reduced.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the outdoor hood with the sound-absorbing material laid on the inner surface as described above, although the effect of absorbing noise (sound-absorbing effect) in the air passage can be enhanced by increasing the thickness of the sound-absorbing material, as the sound-absorbing material becomes thicker, the outdoor hood itself becomes larger, and if it is an expensive sound-absorbing material, there is a problem that the product cost of the outdoor hood increases.

[0006] This invention addresses the aforementioned problems in the prior art and aims to provide a technology that can enhance the sound absorption effect in an airflow path while suppressing an increase in the thickness of the sound-absorbing material. [Means for solving the problem]

[0007] To solve the above-mentioned problems, the outdoor hood of the present invention employs the following configuration: In an outdoor hood that is installed to cover the exhaust port of a duct opening in the exterior wall of a building and has an air passage inside that guides the exhaust gas discharged from the exhaust port to the air outlet, A rear plate having a through hole at the location of the exhaust port and fixed along the wall surface of the outer wall, A front plate is positioned opposite the rear plate with the aforementioned air passage in between, Sound-absorbing material is laid on the air passage side surface of the rear plate and the front plate to absorb noise transmitted through the air passage. Equipped with, The sound-absorbing material is constructed by overlapping an inner sound-absorbing material positioned on the airflow side and an outer sound-absorbing material positioned on the opposite side of the airflow. Comparing the inner sound-absorbing material and the outer sound-absorbing material, the inner sound-absorbing material has higher noise absorption performance, while the outer sound-absorbing material has higher noise reflection performance. It is characterized by the following:

[0008] In the outdoor hood of this invention, when noise traveling through the airflow path enters the sound-absorbing material, it is first partially absorbed by the highly absorbent inner sound-absorbing material. The noise that has passed through the inner sound-absorbing material is then reflected by the highly reflective outer sound-absorbing material, returning to the inner sound-absorbing material and being partially absorbed again. This enhances the noise-absorbing effect (sound absorption effect) of the sound-absorbing material. Furthermore, since highly absorbent sound-absorbing materials are often expensive, by reducing the thickness of the highly absorbent inner sound-absorbing material and combining it with a relatively inexpensive outer sound-absorbing material, it is possible to achieve a high sound absorption effect while keeping the size of the outdoor hood and product costs down.

[0009] In the outdoor hood of the present invention described above, an outer sound-absorbing material that has superior shape retention compared to an inner sound-absorbing material may be used.

[0010] In this way, even if the inner sound-absorbing material, which has high absorption performance, is prone to crumbling, the overall shape stability of the sound-absorbing material can be ensured by layering it with the outer sound-absorbing material, which has excellent shape retention. This makes it possible to lay it on the back or front panel to absorb noise in the airflow path.

[0011] In the outdoor hood of the present invention, the inner packaging material and the outer packaging material may be packaged together in a water-resistant packaging material.

[0012] This method prevents the sound-absorbing material from absorbing moisture from the exhaust passing through the airflow path, and also suppresses the deterioration of the sound-absorbing material due to the blowing of exhaust.

[0013] In the outdoor hood of the present invention described above, the areas where the sound-absorbing material and the packaging material are fixed using adhesive material, or where the inner sound-absorbing material and the outer sound-absorbing material are fixed, may be limited to the peripheral portion of the sound-absorbing material.

[0014] Since the sound-absorbing effect of sound-absorbing material may decrease at points where adhesive is used for fastening, limiting the fastening to the peripheral area rather than the entire surface of the sound-absorbing material can help suppress the reduction in sound-absorbing effect. [Brief explanation of the drawing]

[0015] [Figure 1] This is an exploded perspective view showing the installation method of the outdoor hood 5 in this embodiment. [Figure 2] This is a perspective view showing the shape of the cover sound-absorbing material 22 in this embodiment. [Figure 3] This is a longitudinal cross-sectional view showing the internal structure of the outdoor hood 5 of this embodiment, which is installed on the exterior wall 1 of the building. [Figure 4] This is a schematic cross-sectional view illustrating how sound strikes sound-absorbing material. [Figure 5]It is a longitudinal sectional view showing the configurations of the base sound-absorbing material 14 and the cover sound-absorbing material 22 of this embodiment. [Figure 6] It is an exploded perspective view showing the process of packaging the front sound-absorbing material 23 of this embodiment with a packaging material.

Modes for Carrying Out the Invention

[0016] FIG. 1 is an exploded perspective view showing the installation method of the outdoor hood 5 of this embodiment. In the illustrated example, a duct 3 is inserted from the indoor side into a duct hole 2 provided in the outer wall 1 of a building, and an exhaust port 3a at the end of the duct 3 is open to the outer wall 1. When installing the outdoor hood 5 that covers this exhaust port 3a, first, a base plate 10 is fixed along the wall surface of the outer wall 1. The base plate 10 is formed of sheet metal and has a through hole 10a at the position of the exhaust port 3a. After aligning the exhaust port 3a and the through hole 10a, the left and right two positions at the upper part of the base plate 10 are fixed first using fixing tools such as screws 11. Incidentally, the base plate 10 of this embodiment corresponds to the "rear plate" of the present invention. Also, the fixing tool is not limited to the screw 11 and may be a nut for an anchor or the like.

[0017] Thereafter, a hood cover 20 is attached to the base plate 10. The hood cover 20 is formed of sheet metal and has a front surface 20a disposed opposite to the base plate 10, left and right side surfaces 20b, 20c located on both the left and right sides with respect to this front surface 20a, and an upper surface 20d located on the upper side, and is in a substantially rectangular parallelepiped box shape with the surface on the base plate 10 side and the lower surface being open. Incidentally, the front surface 20a of the hood cover 20 of this embodiment corresponds to the "front plate" of the present invention.

[0018] And in FIG. 1, although shown separated from the hood cover 20, a gallery 30 is pre-fixed covering the lower surface of the hood cover 20. The gallery 30 has a plurality of wind direction plates 30a arranged in parallel and is joined to the left and right side surfaces 20b, 20c of the hood cover 20 by spot welding or screws (not shown).

[0019] Further, on the upper surface 20d of the hood cover 20, a groove 21 extending in the left - right direction is formed by being recessed from the inside to the outside. On the other hand, at the upper end of the base plate 10, a flange 12 is provided by bending it toward the hood cover 20 side, and a ridge 13 extending in the left - right direction is formed by protruding upward from this flange 12.

[0020] When attaching the hood cover 20 to the base plate 10, after fitting the ridge 13 of the flange 12 into the groove 21 of the upper surface 20d for upper positioning, the lower parts are aligned and fixed to the outer wall 1 with a fixture such as a screw 11. In this embodiment, together with the gallery 30 pre - fixed to the hood cover 20, the left and right two positions at the lower part of the base plate 10 are jointly fixed with screws 11.

[0021] When the hood cover 20 is attached in this way, the surface of the base plate 10 opposite to the outer wall 1 is covered by the hood cover 20, and an air passage described later is formed between the base plate 10 and the front surface 20a of the hood cover 20. The exhaust discharged from the exhaust port 3a is guided through the air passage to the blow - out port at the lower end. Then, the exhaust blown out from the blow - out port is directed in the direction away from the outer wall 1 (forward) by passing between the wind - direction plates 30a of the gallery 30.

[0022] Furthermore, in this embodiment, a base sound - absorbing material 14 for absorbing sound is laid on the surface of the base plate 10 on the hood cover 20 side (air - passage side). The base sound - absorbing material 14 is provided with ventilation holes 14a at the positions of the through - holes 10a of the base plate 10, and the hole diameter of the ventilation holes 14a is slightly larger than the hole diameter of the through - holes 10a. The base sound - absorbing material 14 is fixed to the base plate 10 using an adhesive or double - sided tape, etc. Similarly, a cover sound - absorbing material 22 for absorbing sound is laid on the inner surface of the hood cover 20 and is fixed with an adhesive or double - sided tape, etc.

[0023] Figure 2 is a perspective view showing the shape of the cover sound-absorbing material 22 of this embodiment. The figure shows the state before the cover sound-absorbing material 22 is fixed to the hood cover 20. As shown in the figure, the cover sound-absorbing material 22 consists of a front sound-absorbing material 23 corresponding to the front surface 20a of the hood cover 20 and a top sound-absorbing material 24 corresponding to the top surface 20d. The hood cover 20 is attached to the base plate 10 with the cover sound-absorbing material 22 fixed to its inner surface. In this embodiment, the cover sound-absorbing material 22 does not have side sound-absorbing materials corresponding to the left and right sides 20b and 20c of the hood cover 20, but side sound-absorbing materials corresponding to the left and right sides 20b and 20c may be provided.

[0024] Figure 3 is a longitudinal cross-sectional view showing the internal structure of the outdoor hood 5 of this embodiment, installed on the exterior wall 1 of a building. The figure shows a cross-section of the outdoor hood 5 cut by a vertical plane passing through the central axis of the duct 3. In the illustrated example, the through-hole 10a of the base plate 10 is formed to be larger than the exhaust port 3a of the duct 3, and the through-hole 10a and the exhaust port 3a are connected by an adapter 15. The adapter 15 is cylindrical with a smaller diameter than the duct 3, and has a flange portion at one end with an outer diameter larger than the diameter of the through-hole 10a. The other end of the adapter 15 is inserted through the through-hole 10a and the exhaust port 3a, and a sealing material 16 is interposed between the inner circumference of the duct 3 and the cylindrical outer circumference of the adapter 15. In this embodiment, caulking material is used as the sealing material 16, but it is not limited to this, and an O-ring or the like can be appropriately selected as long as it has a sealing function.

[0025] Furthermore, a drip plate 17 is provided at the lower end of the base plate 10, which is sloped downward toward the front surface 20a of the hood cover 20. This drip plate 17 helps to prevent staining of the exterior wall 1 by causing rainwater and other water droplets dripping from the outdoor hood 5 to fall away from the exterior wall 1.

[0026] With the hood cover 20 attached to the base plate 10, the aforementioned air passage 6 is formed inside the outdoor hood 5. Exhaust air discharged from the exhaust port 3a of the duct 3 flows into the outdoor hood 5 through the through hole 10a, is guided to the air passage 6, and blows out from the outlet 7 at the lower end. A gallery 30 covers this downward-opening outlet 7, and multiple wind deflectors 30a are formed parallel to each other on the gallery 30 by cutting and bending a plate-shaped member. The wind deflectors 30a are inclined downward from the base plate 10 side toward the front surface 20a side of the hood cover 20, and the exhaust air that passes between the wind deflectors 30a is blown away from the outer wall 1 (to the left in the figure). This suppresses the soiling of the outer wall 1 by the exhaust air.

[0027] Furthermore, in the outdoor hood 5, noise can leak from indoors to outdoors via the duct 3 and air passage 6. For example, if noise is generated by a clothes dryer or heater connected upstream of the duct 3, it will travel through the duct 3 and air passage 6 along with the exhaust and leak out from the outlet 7. Conversely, outdoor noise can also resonate indoors from the outlet 7 through the air passage 6 and duct 3. Therefore, in order to reduce such noise, as mentioned above, base sound-absorbing material 14 is laid on the air passage 6 side of the base plate 10, and cover sound-absorbing material 22 (front sound-absorbing material 23 and top sound-absorbing material 24) is laid on the inner surface of the hood cover 20. In other words, the air passage 6 is formed sandwiched between the base sound-absorbing material 14 and the front sound-absorbing material 23.

[0028] The noise emitted along with the exhaust from the exhaust port 3a of the duct 3 enters the air passage 6 through the through-hole 10a of the base plate 10 and the ventilation holes 14a of the base sound-absorbing material 14, as shown by the dashed arrows in the figure. First, it hits the front sound-absorbing material 23 and is partially absorbed. The noise reflected from the front sound-absorbing material 23 then hits the base sound-absorbing material 14 and is partially absorbed. Furthermore, the noise reflected from the base sound-absorbing material 14 hits the front sound-absorbing material 23 again and is partially absorbed. By repeating this process, the noise leaking from the air outlet 7 is reduced.

[0029] As such, noise absorption and reflection in the airflow path 6 occur mainly with the front sound-absorbing material 23 and the base sound-absorbing material 14. Therefore, in this embodiment, the cover sound-absorbing material 22 omits the side sound-absorbing materials corresponding to the left and right sides 20b and 20c of the hood cover 20, as mentioned above. By omitting the side sound-absorbing materials of the cover sound-absorbing material 22, it is possible to secure the cross-sectional area of ​​the airflow path 6 while avoiding an increase in the size of the outdoor hood 5.

[0030] Furthermore, in the outdoor hood 5 of this embodiment, the vertical distance D1 from the ventilation hole 14a to the outlet 7 in the air passage 6 is longer than the front-to-back distance D2 from the base sound-absorbing material 14 to the front sound-absorbing material 23, and in the illustrated example, it is set to more than 7 times. By shortening the front-to-back distance D2 of the air passage 6 in this way, the cycle in which noise collides with the front sound-absorbing material 23 and the base sound-absorbing material 14 is shortened, while by lengthening the vertical distance D1 of the air passage 6, the number of times noise is absorbed by collisions with the front sound-absorbing material 23 and the base sound-absorbing material 14 before it reaches the outlet 7 from the exhaust port 3a can be increased, thus reducing the noise leaking from the outlet 7.

[0031] As the base sound-absorbing material 14 and the cover sound-absorbing material 22, well-known sound-absorbing materials can be used. For example, porous sound-absorbing materials such as glass wool, rock wool, urethane foam, and melamine foam are common, and they produce a sound-absorbing effect by converting a portion of the noise energy into thermal energy. Figure 4 is a schematic cross-sectional view showing how sound strikes a sound-absorbing material. As shown in the figure, when sound enters the sound-absorbing material, some is reflected, some is absorbed, and some is transmitted.

[0032] If we denote the energy of the incident sound as Ei, the energy of the reflected sound as Er, the energy of the absorbed sound as Ea, and the energy of the transmitted sound as Et, then according to the law of conservation of energy, Ei = Er + Ea + Et The following relationship holds. Also, if we let R be the reflectance, A be the absorptiveness, and T be the transmittance, then each of them is R=Er / Ei A = Ea / Ei T = Et / Ei It can be expressed as follows.

[0033] When sound enters and diffuses within a porous material, the air vibrations are transmitted to the air in the bubbles within the material. Due to friction and viscous resistance on the surface of the bubbles, some of the sound energy is converted into thermal energy and absorbed (dissipated). The absorption rate A (efficiency of conversion to thermal energy) at this time varies depending not only on the material of the sound-absorbing material (such as the thickness of the fibers) but also on the size of the bubbles, and tends to decrease as the density increases, and is highly dependent on the frequency of the sound.

[0034] Furthermore, the sound absorption coefficient α is sometimes used as an indicator to judge the performance of sound-absorbing materials. The sound absorption coefficient α is the ratio of the energy of sound that was not reflected to the energy of the incident sound. α = (Ea + Et) / Ei =(Ei-Er) / Ei = 1 - R It can be expressed as follows. Furthermore, since the sound absorption coefficient α changes depending on the angle at which sound is incident, it is common to use the sound absorption coefficient when sound is incident on the sound-absorbing material from all directions (reverberation chamber method sound absorption coefficient), and the measurement method is defined in the JIS standard.

[0035] The base sound-absorbing material 14 and the cover sound-absorbing material 22 can be appropriately selected according to the magnitude and frequency of the noise emitted from the exhaust port 3a of the duct 3. Generally, the sound-absorbing effect can be increased by increasing the thickness of the sound-absorbing material. However, in the case of the outdoor hood 5, it is necessary to secure the cross-sectional area of ​​the air passage 6 (to avoid increasing exhaust resistance), so if the sound-absorbing material is made thicker, the outdoor hood 5 itself will become larger. In addition, high-performance sound-absorbing materials are often expensive, and the product cost of the outdoor hood 5 increases with increasing the thickness of the sound-absorbing material. Therefore, the base sound-absorbing material 14 and the cover sound-absorbing material 22 of the outdoor hood 5 in this embodiment are configured as follows.

[0036] Figure 5 is a longitudinal cross-sectional view showing the configuration of the base sound-absorbing material 14 and cover sound-absorbing material 22 of this embodiment. In the figure, the outdoor hood 5 is cut by a vertical plane perpendicular to the outer wall 1, and the cross-sections of the base sound-absorbing material 14 and front sound-absorbing material 23 are shown enlarged with the air passage 6 in between. As shown in the figure, the base sound-absorbing material 14 of this embodiment is constructed by overlapping an inner sound-absorbing material 14b, which is placed on the air passage 6 side, and an outer sound-absorbing material 14c, which is placed on the base plate 10 side. Similarly, the front sound-absorbing material 23 of this embodiment is constructed by overlapping an inner sound-absorbing material 23a, which is placed on the air passage 6 side, and an outer sound-absorbing material 23b, which is placed on the front surface 20a side of the hood cover 20. Although not shown in the figure, the top sound-absorbing material 24 is also constructed by overlapping an inner sound-absorbing material, which is placed on the air passage 6 side, and an outer sound-absorbing material, which is placed on the top surface 20d side of the hood cover 20.

[0037] In this embodiment, rock wool is used as the inner sound-absorbing material 14b, 23a, and urethane foam is used as the outer sound-absorbing material 14c, 23b. Comparing the inner sound-absorbing material 14b, 23a with the outer sound-absorbing material 14c, 23b, the absorption rate A (absorption performance that absorbs noise) is higher for the inner sound-absorbing material 14b, 23a, while the reflectance R (reflectance performance that reflects noise) is higher for the outer sound-absorbing material 14c, 23b. Note that the combination of the inner sound-absorbing material 14b, 23a and the outer sound-absorbing material 14c, 23b is not limited to this, as long as the performance conditions are met. For example, although both are glass wool, the inner sound-absorbing material 14b, 23a may be glass wool with a lower density and higher absorption rate A than the outer sound-absorbing material 14c, 23b.

[0038] Figure 5 schematically illustrates how noise enters the front sound-absorbing material 23 from the air duct 6 side, using the front sound-absorbing material 23 as an example. As shown in the figure, when noise enters the front sound-absorbing material 23 from the air duct 6 side, a portion of it is first absorbed as heat by the inner sound-absorbing material 23a, which has a high absorption rate A. Then, the noise that has passed through the inner sound-absorbing material 23a is subsequently entered by the outer sound-absorbing material 23b, which has a high reflectivity R. At this time, although a portion of the noise is also absorbed as heat by the outer sound-absorbing material 23b, the noise reflected by the outer sound-absorbing material 23b returns to the inner sound-absorbing material 23a and is absorbed again, thus increasing the noise absorption effect (sound absorption effect) of the front sound-absorbing material 23.

[0039] Furthermore, noise that enters from the air passage 6 side and is reflected by the inner sound-absorbing material 23a, and noise that is reflected by the outer sound-absorbing material 23b and then transmitted through the inner sound-absorbing material 23a, enters the base sound-absorbing material 14 on the opposite side via the air passage 6, where it is absorbed or reflected in the same way as in the case of the front sound-absorbing material 23. By repeating this process, the noise transmitted through the air passage 6 is reduced.

[0040] Furthermore, since sound-absorbing materials with a high absorption rate A are often expensive, by reducing the thickness of the inner sound-absorbing materials 14b and 23a, which have a high absorption rate A, and combining them with the relatively inexpensive outer sound-absorbing materials 14c and 23b, it becomes possible to increase the size of the outdoor hood 5 and reduce product costs while still achieving a high sound absorption effect.

[0041] Furthermore, some sound-absorbing materials with a high absorption rate A are brittle and easily crumble. In this embodiment, the base sound-absorbing material 14 and the front sound-absorbing material 23 are constructed by layering two types of sound-absorbing materials. Therefore, even if a sound-absorbing material that easily crumbles is used for the inner sound-absorbing materials 14b and 23a, the outer sound-absorbing materials 14c and 23b can be made to be layered with a sound-absorbing material that has better shape retention than the inner sound-absorbing materials 14b and 23a.

[0042] For example, even if the rock wool used for the inner sound-absorbing materials 14b and 23a is prone to crumbling, by layering it with urethane foam, which has relatively good shape retention, as the outer sound-absorbing materials 14c and 23b, the overall shape stability of the base sound-absorbing material 14 and the front sound-absorbing material 23 can be ensured and the dimensions controlled, making it possible to lay them on the base plate 10 and hood cover 20 to absorb noise in the air passage 6. Alternatively, since glass wool has a higher absorption rate A as its density decreases, but tends to have poor shape retention and crumble easily, if low-density glass wool is used for the inner sound-absorbing materials 14b and 23a, high-density glass wool can be used for the outer sound-absorbing materials 14c and 23b and layered together to ensure the overall shape stability of the base sound-absorbing material 14 and the front sound-absorbing material 23 and to control the dimensions. Furthermore, although detailed illustrations are omitted in Figure 5, the base sound-absorbing material 14 and the front sound-absorbing material 23 in this embodiment are packaged in packaging material.

[0043] Figure 6 is an exploded perspective view showing the process of packaging the front sound-absorbing material 23 of this embodiment with packaging material. The packaging material of this embodiment is made of a water-resistant material such as aluminum film and consists of two components, a first packaging material 25 and a second packaging material 26, as shown in the figure. The first packaging material 25 covers only one side of the front sound-absorbing material 23 on the side facing the air passage 6. In contrast, the second packaging material 26 has a front portion 26a that covers the side of the front sound-absorbing material 23 opposite to the air passage 6 (the side facing the front 20a of the hood cover 20), side portions 26b that are bent from both the left and right sides of the front portion 26a toward the first packaging material 25 and cover the sides of the front sound-absorbing material 23, and a folded portion 26c that is folded inward on the side of the side portion 26b opposite to the front portion 26a.

[0044] First, the first packaging material 25 is fixed to the inner sound-absorbing material 23a with adhesive 27a. At this time, the adhesive 27a is applied only to the peripheral portion of the inner sound-absorbing material 23a, rather than to the entire surface. Since the sound-absorbing effect of the inner sound-absorbing material 23a may decrease at the points where the adhesive 27a is applied, limiting the application of the adhesive 27a to the peripheral portion of the inner sound-absorbing material 23a makes it possible to suppress the decrease in sound-absorbing effect.

[0045] Furthermore, the inner sound-absorbing material 23a is fixed to the outer sound-absorbing material 23b with adhesive 27b, and this adhesive 27b, like the adhesive 27a described above, is applied only to the peripheral areas of the outer sound-absorbing material 23b and the inner sound-absorbing material 23a. Note that the bond between the inner sound-absorbing material 23a and the outer sound-absorbing material 23b may be omitted, and they may simply be overlapped.

[0046] The outer sound-absorbing material 23b, with the inner sound-absorbing material 23a superimposed on it, is then fixed to the front portion 26a of the second packaging material 26 with adhesive 27c. Here again, the adhesive 27c is applied only to the peripheral portion of the outer sound-absorbing material 23b, not to the entire surface. The inner sound-absorbing material 23a and the outer sound-absorbing material 23b are then sandwiched from both sides by the side portions 26b of the second packaging material 26, and the folded portion 26c is fixed to the left and right edges of the first packaging material 25 with adhesive 27d. Note that the adhesive 27 (27a to 27d) in this embodiment corresponds to the "adhesive material" of the present invention.

[0047] In this way, the inner sound-absorbing material 23a and the outer sound-absorbing material 23b of the front sound-absorbing material 23 are packaged together in a water-resistant packaging material (first packaging material 25 and second packaging material 26), which prevents the front sound-absorbing material 23 from absorbing moisture from the exhaust passing through the air passage 6 and also suppresses deterioration of the front sound-absorbing material 23 due to the blowing of exhaust. Similarly to the front sound-absorbing material 23, the base sound-absorbing material 14 also has its inner sound-absorbing material 14b and outer sound-absorbing material 14c packaged together in a water-resistant packaging material.

[0048] As described above, in the outdoor hood 5 of this embodiment, both the base sound-absorbing material 14 and the front sound-absorbing material 23 are constructed by overlapping inner sound-absorbing materials 14b and 23a, which are placed on the side facing the air passage 6, with outer sound-absorbing materials 14c and 23b, which are placed on the opposite side from the air passage 6. Comparing the inner sound-absorbing materials 14b and 23a with the outer sound-absorbing materials 14c and 23b, the inner sound-absorbing materials 14b and 23a have higher noise absorption performance, while the outer sound-absorbing materials 14c and 23b have higher noise reflection performance.

[0049] In this embodiment of the outdoor hood 5, when noise traveling through the air passage 6 enters the base sound-absorbing material 14 and the front sound-absorbing material 23, a portion is first absorbed as heat by the highly absorbent inner sound-absorbing materials 14b and 23a. The noise that has passed through the inner sound-absorbing materials 14b and 23a is then reflected by the highly reflective outer sound-absorbing materials 14c and 23b, returning to the inner sound-absorbing materials 14b and 23a and being partially absorbed again. This enhances the noise absorption effect (sound absorption effect) of the base sound-absorbing material 14 and the front sound-absorbing material 23. Furthermore, since highly absorbent sound-absorbing materials are often expensive, by reducing the thickness of the highly absorbent inner sound-absorbing materials 14b and 23a and combining them with the relatively inexpensive outer sound-absorbing materials 14c and 23b, it becomes possible to achieve a high sound absorption effect while keeping the size of the outdoor hood 5 and product costs down.

[0050] Furthermore, in the outdoor hood 5 of this embodiment, outer sound-absorbing materials 14c and 23b, which have superior shape retention compared to inner sound-absorbing materials 14b and 23a, are used. In this way, even if the inner sound-absorbing materials 14b and 23a, which have high absorption performance, are prone to collapse, the overall shape stability of the base sound-absorbing material 14 and front sound-absorbing material 23 can be ensured by layering them with the outer sound-absorbing materials 14c and 23b, which have superior shape retention, making it possible to lay them on the base plate 10 and hood cover 20 to absorb noise in the air passage 6.

[0051] Furthermore, in the outdoor hood 5 of this embodiment, the inner sound-absorbing material 23a and the outer sound-absorbing material 23b of the front sound-absorbing material 23 are packaged together in a water-resistant packaging material (first packaging material 25 and second packaging material 26), and the same applies to the base sound-absorbing material 14. This prevents the base sound-absorbing material 14 and the front sound-absorbing material 23 from absorbing moisture from the exhaust passing through the air passage 6, and also suppresses deterioration of the base sound-absorbing material 14 and the front sound-absorbing material 23 due to the blowing of exhaust.

[0052] Furthermore, in the outdoor hood 5 of this embodiment, the areas where the front sound-absorbing material 23 and the packaging material (first packaging material 25 and second packaging material 26) are fixed using adhesive 27, and the areas where the inner sound-absorbing material 23a and the outer sound-absorbing material 23b are fixed, are limited to the peripheral portion of the front sound-absorbing material 23, and the same applies to the base sound-absorbing material 14. Since the sound-absorbing effect of the base sound-absorbing material 14 and the front sound-absorbing material 23 may decrease at the areas fixed with adhesive 27, limiting the fixing areas to the peripheral portion rather than the entire surface of the base sound-absorbing material 14 and the front sound-absorbing material 23 makes it possible to suppress the decrease in sound-absorbing effect.

[0053] Although the outdoor hood 5 of this embodiment has been described above, the present invention is not limited to the above embodiment and can be implemented in various forms without departing from the spirit of the invention.

[0054] For example, in the embodiment described above, adhesive 27 was used to fix the front sound-absorbing material 23 to the packaging material (first packaging material 25 and second packaging material 26), and to fix the inner sound-absorbing material 23a to the outer sound-absorbing material 23b. However, instead of adhesive 27, double-sided tape or the like may be used for fixing. Note that even at fixing points using double-sided tape, the sound-absorbing effect of the front sound-absorbing material 23 may decrease, so limiting the fixing points to the peripheral area of ​​the front sound-absorbing material 23 makes it possible to suppress the decrease in sound-absorbing effect. [Explanation of Symbols]

[0055] 1...Exterior wall, 2...Duct hole, 3...Duct, 3a... Exhaust vent, 5... Outdoor hood, 6... Air duct, 7...Air outlet, 10...Base plate, 10a...Through hole, 11... Screw, 12... Flange, 13... Rib, 14...Base sound-absorbing material, 14a...Ventilation holes, 14b...Inner sound-absorbing material, 14c...Outer sound-absorbing material, 15...Adapter, 16...Sealing material, 17...Draining plate, 20...Food cover, 20a...Front, 20b...left side, 20c...right side, 20d...top side, 21... Groove, 22... Cover sound-absorbing material, 23... Front sound-absorbing material, 23a...Inner sound absorbing material, 23b...Outer sound absorbing material, 24...Top sound absorbing material, 25...first packaging material, 26...second packaging material, 26a...front part, 26b...Side section, 26c...Folded section, 27...Adhesive, 30...Gallery, 30a...Wind deflector.

Claims

1. In an outdoor hood that is installed to cover the exhaust port of a duct opening in the exterior wall of a building and has an air passage inside that guides the exhaust gas discharged from the exhaust port to the air outlet, A rear plate having a through hole at the location of the exhaust port and fixed along the wall surface of the outer wall, A front plate is positioned opposite the rear plate with the aforementioned air passage in between, Sound-absorbing material is laid on the air passage side surface of the rear plate and the front plate to absorb noise transmitted through the air passage. Equipped with, The sound-absorbing material is constructed by overlapping an inner sound-absorbing material positioned on the airflow side and an outer sound-absorbing material positioned on the opposite side of the airflow. Comparing the inner sound-absorbing material and the outer sound-absorbing material, the inner sound-absorbing material has higher noise absorption performance, while the outer sound-absorbing material has higher noise reflection performance. The outer sound-absorbing material has superior shape retention properties compared to the inner sound-absorbing material, making it less prone to collapse and allowing it to maintain its shape. An outdoor hood characterized by the following features.

2. In the outdoor hood according to claim 1, The sound-absorbing material is packaged together with the inner and outer sound-absorbing materials in a water-resistant packaging material. An outdoor hood characterized by the following features.

3. In an outdoor hood that is installed to cover the exhaust port of a duct opening in the exterior wall of a building and has an air passage inside that guides the exhaust gas discharged from the exhaust port to the air outlet, A rear plate having a through hole at the location of the exhaust port and fixed along the wall surface of the outer wall, A front plate is positioned opposite the rear plate with the aforementioned air passage in between, Sound-absorbing material is laid on the air passage side surface of the rear plate and the front plate to absorb noise transmitted through the air passage. Equipped with, The sound-absorbing material is constructed by overlapping an inner sound-absorbing material positioned on the airflow side and an outer sound-absorbing material positioned on the opposite side of the airflow. Comparing the inner sound-absorbing material and the outer sound-absorbing material, the inner sound-absorbing material has higher noise absorption performance, while the outer sound-absorbing material has higher noise reflection performance. The sound-absorbing material is packaged together with the inner and outer sound-absorbing materials in a water-resistant packaging material. An outdoor hood characterized by the following features.

4. In the outdoor hood according to claim 2 or claim 3, The sound-absorbing material is limited to the peripheral portion of the sound-absorbing material, where the packaging material is fixed using an adhesive, or where the inner sound-absorbing material and the outer sound-absorbing material are fixed together. An outdoor hood characterized by the following features.

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