JP3792279B2 - Noise prevention sheet laminate, noise prevention device and combustion device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention used a noise preventing sheet stack, regarding the noise preventing device and combustion apparatus for the combustion device.
[0002]
[Prior art]
In a general gas combustion system for hot water supply, when the combination of factors such as the size and length of the chimney, the volume of the housing, and the combustion characteristics of the burner satisfy the resonance condition, resonance of the combustion noise occurs, and a large noise with low frequency Will occur.
[0003]
[Problems to be solved by the invention]
Therefore, it has been desired to develop an apparatus that can eliminate the possibility of resonance.
[0004]
[Means for Solving the Problems]
The invention of claim 1 is a combustion apparatus comprising a burner, a heat exchanger disposed above the burner, a housing that houses the burner and the heat exchanger, and a chimney connected to an exhaust port of the housing. In the noise prevention apparatus for the above, a noise prevention sheet laminate is disposed in a space connected to the exhaust passage downstream of the heat exchanger, and the noise prevention sheet laminate includes a rubber vibration sheet, A thinner heat-resistant sheet made of resin is laminated, and only the peripheral edge thereof is fixed, the heat-resistant sheet is directed to the exhaust passage side, and the vibration sheet and the heat-resistant sheet are other than the peripheral edge. All the parts are simply in contact and laminated.
The invention of claim 2 is a combustion apparatus comprising a burner, a heat exchanger disposed above the burner, a housing for housing the burner and the heat exchanger, and a chimney connected to an exhaust port of the housing. In the noise prevention apparatus for the above, a noise prevention sheet laminate is disposed in a space connected to the exhaust passage downstream of the heat exchanger, and the noise prevention sheet laminate includes a rubber vibration sheet, The heat-resistant sheet made of resin thinner than the vibration sheet laminated on one surface side of the vibration sheet, and a flexible mesh laminated on the other surface side of the vibration sheet. Only the periphery is fixed, the heat-resistant sheet faces the exhaust passage, and the vibration sheet, the heat-resistant sheet, and the mesh are simply in contact with each other except for the periphery. It is characterized by only being laminated by touching.
The invention of claim 3 comprises a burner, a heat exchanger disposed above the burner, a housing for housing the burner and the heat exchanger, and a chimney connected to an exhaust port of the housing. In the noise prevention apparatus for the above, a noise prevention sheet laminate is disposed in a space connected to the exhaust passage downstream of the heat exchanger, and the noise prevention sheet laminate includes a rubber vibration sheet, The heat-resistant sheet made of resin thinner than the vibration sheet laminated on one surface side of the vibration sheet, and a flexible mesh laminated on the other surface side of the vibration sheet. Only the periphery is fixed, the heat-resistant sheet faces the exhaust passage side, and the noise-preventing sheet includes the heat-resistant sheet, the vibration sheet, the mesh, and a ring-shaped frame. The plate is laminated in this order, and an extension is provided on the periphery of the heat-resistant sheet, and the extension is bent so that the periphery of the vibration sheet, the mesh, and the frame plate are wrapped. It is characterized by being fixed to the frame plate.
According to a fourth aspect of the present invention, in the combustion apparatus, the noise prevention apparatus according to any one of the first to third aspects is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an outdoor-installed gas hot water supply device (combustion device) according to a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the gas hot water supply device includes a housing 10. The housing 10 includes a housing main body 11 and a front cover 12 (front wall of the housing). Inside, a fan, a gas burner (combustion unit), and a heat exchanger (all not shown) are arranged in order from the bottom. Contained. An exhaust port 15 is formed in the upper wall of the housing 10, and an exhaust chamber (not shown) is formed between the exhaust port 15 and the heat exchanger.
[0008]
A metal attachment box 20 with a noise prevention device, which will be described later, is attached to the upper wall of the housing 10, and a chimney 18 is attached to the upper wall of the attachment box 20 via a mounting bracket 16. The exhaust chamber at the top of the housing 10 is connected to the internal space of the chimney 18 via a first chamber 25 (to be described later) of the attachment box 20, and these constitute an exhaust passage.
[0009]
As shown in FIGS. 1 and 2, the attachment box 20 includes a box body 21 whose front side is open, and a protective cover 22 (front wall of the attachment box) that covers the opening of the box body 21. It has a shape. The flange 21x formed on the opening periphery of the box body 21 and the flange 22x formed on the protective cover 22 are fixed by screws 40 with a sheet laminate 30 described later interposed therebetween.
[0010]
A large number of through holes 22 a are formed in the protective cover 22. As shown in FIG. 2 or 3, an opening 21 a connected to the exhaust port 15 of the housing 10 is formed on the bottom wall of the box body 21, and the mounting bracket 16 and the chimney 18 are installed on the upper wall. An opening 21b is formed at the position.
[0011]
A partition wall 23 having a U-shaped planar shape is provided in the attachment box 20. A partition wall 24 that is parallel to these is also disposed between the front portion of the partition wall 23 and the protective cover 22. The sheet laminate 30 is disposed between the partition wall 24 and the protective cover 22.
[0012]
The internal space of the attachment box 20 is partitioned into four chambers 25-28. The first chamber 25 is formed so as to be surrounded by the back wall of the box body 21 and the partition wall 23 and constitutes a part of the exhaust passage connected to the openings 21a and 21b. The second chamber 26 is formed between the partition walls 23 and 24. The third chamber 27 is formed between the partition wall 24 and the sheet laminate 30. The fourth chamber 28 is formed between the sheet laminate 30 and the protective cover 22.
[0013]
A plurality of openings 23 a (sound wave transmission passages) arranged vertically are formed in a pair of side surfaces of the partition wall 23 at positions close to the back wall of the box body 21. A plurality of vertically arranged openings 24a (sound wave transmission paths) are formed in the vicinity of the left and right side edges of the partition wall 24, and a plurality of openings 24a are also arranged in the vicinity of both ends of the lower edge. It is formed with. Further, a pair of guide walls 29 fixed to both side walls of the box body 21 are disposed in the third chamber 27. The guide wall 29 is parallel to the partition wall 24 and the sheet stack 30 and is opposed to the vertically aligned openings 24a.
[0014]
Next, the sheet laminate 30 will be described in detail. As shown in FIGS. 4 and 6, the sheet laminate 30 includes a heat-resistant sheet 31 made of a heat-resistant resin, a rubber vibration sheet 32, a mesh 33, and a rectangular ring-shaped frame plate 34 in this order. It is a thing. Here, as the heat-resistant sheet 31, a sheet made of heat-resistant resin such as polytetrafluoroethylene (fluorine resin) and having a thickness of 100 μm or less (for example, about 50 μm thickness) is used. As the rubber vibration sheet 32, a foamed silicone sheet having a thickness of about 1 to 2 mm is used. Note that other foamed elastic sheets such as urethane, and non-foamed elastic sheets such as silicone, fluorine-based rubber, and urethane may be used as the rubber-like vibration sheet 32. As the mesh 33, a flexible mesh of about a very thin wire (corresponding to a wire diameter of 50 μm or less, for example, 40 μm) of a corrosion-resistant metal such as stainless steel is used. It may be a glass fiber, carbon fiber, or fluorine fiber mesh. As the frame plate 34, a stainless steel plate having a thickness of about 1 mm is used.
[0015]
When the sheet laminate 30 is manufactured, as shown in FIG. 6, an assembly table 60 having a large number of positioning protrusions 61 on the upper surface is used. The heat-resistant sheet 31, the vibration sheet 32, the mesh 33, the frame plate 34, and the double-sided adhesive tape 35 are placed while being stacked in this order. These are formed with screw holes 31h, 32h, 33h, 34h, and 35h, respectively, and are positioned by fitting these screw holes into the positioning protrusions 61. Note that after the mesh 33 is placed, the silicone adhesive 36 is applied over the entire periphery of the periphery (except for the vicinity of the screw holes 33h). By placing the frame plate 34 after this application, the frame plate 34 is bonded to the vibration sheet 32 via the mesh 33. After the last double-sided adhesive tape 35 is placed, the extended portion 31a formed on the peripheral edge of the heat-resistant sheet 31 is folded back and pressed over the double-sided adhesive tape 35 so that the extended portion 31a becomes the frame plate 34. Glued to.
[0016]
The heat-resistant sheet 31, the vibration sheet 32, and the mesh 33 are fixed to the frame plate 34 with their peripheral portions fixed directly or indirectly to each other, but in all other parts except the peripheral portions, Simply contact and stack.
[0017]
The sheet laminate 30 manufactured as described above is arranged with the heat-resistant sheet 31 facing the inside, that is, the third chamber 27 side (high temperature side), and the mesh 33 facing the outside, that is, the fourth chamber 28 side (low temperature side). As shown in FIG. 2, the peripheral portion is sandwiched and fixed between the flange 21 x of the box body 21 and the flange 22 x of the protective cover 22. The screw 40 for fixing passes through the screw holes 31h, 32h, 33h, 34h, and 35h.
[0018]
As shown in FIG. 2, a vibration suppression member 50 made of an extremely soft resin such as foamed silicone having a higher foaming rate than the vibration sheet 32 is bonded to the center of the inner surface of the protective cover 22 . The vibration suppressing member 50 is opposed to the central portion (or the vicinity thereof) of the sheet laminate 30 and is in contact with the mesh 33. There may be a gap between the vibration suppressing member 50 and the mesh 33. Further, one or a plurality of vibration suppressing members 50 may be provided not around the center of the sheet laminate 30.
[0019]
As shown in FIG. 5, the vibration suppressing member 50 is configured by bonding two foamed silicone pads 51 and 52. The pad 51 disposed on the sheet laminate 30 side (inner side) has closed cells 51a, and smooth skin layers 51b are formed on both sides. Further, the outer pad 52 has open cells 52a. In addition, the foaming degree of these pads 51 and 52 is adjusted according to load.
[0020]
In the gas hot water supply apparatus having the above configuration, the heat exchanger is heated by the combustion heat in the gas burner, and the water passing through the heat exchanger is heated to become hot water. The combustion exhaust gas is discharged to the outside through the heat exchanger, the exhaust chamber, the first chamber 25 of the attachment box 20 and the chimney 18.
[0021]
In the gas burner 13, noise is generated with combustion. However, if the gas hot water supply apparatus satisfies the resonance and resonance conditions, the combustion noise may cause very loud noise. This resonance condition is satisfied, for example, when the chimney 18 reaches a certain length. Since the length of the chimney 18 is appropriately adjusted according to the installation location of the gas hot water supply device, there is a possibility that this resonance condition is satisfied and noise is generated. However, in this embodiment, such noise can be prevented.
[0022]
More specifically, the pressure wave of the combustion sound, that is, the sound wave, is transmitted from the first chamber 25 to the opening 23a of the partition wall 23, the second chamber 26, and the partition wall 24 in the attachment box 20, as indicated by the arrows in FIG. It enters the third chamber 27 through the opening 24 a and is transmitted to the sheet laminate 30. As the sheet laminate 30 vibrates, sound wave energy is converted into heat energy and absorbed. In this way, the generation of noise can be prevented.
[0023]
The sound wave that has passed through the opening 24a is guided to the guide wall 29 and is directed toward the center of the third chamber 27, and causes the sheet laminate 30 to vibrate efficiently. Further, since the through hole 22 a is formed in the protective cover 22, the fourth chamber 28 between the protective cover 22 and the sheet laminate 30 does not become a sealed space, which hinders the sound absorption function of the sheet laminate 30. I will not give you.
[0024]
In the sheet laminate 30, absorption of sound wave energy is mainly performed by the rubber vibration sheet 32. This rubber-like vibration sheet 32 absorbs the entire frequency band of 1 kHz or less, and particularly absorbs the low frequency region of 200 Hz or less. This absorption function is much better than other materials such as metal sheets. Therefore, even if the length of the chimney 18 is significantly changed, noise accompanying resonance in the low frequency region can be reliably prevented.
[0025]
Since the mesh 33 is laminated on the vibration sheet 32, excessive vibration of the vibration sheet 32 is suppressed by the mesh 33, and an extreme increase in amplitude and fluttering are prevented. Accordingly, it is possible to suppress deterioration due to large deformation of the rubber-like vibration sheet 32 having relatively low strength, and it is possible to suppress the size expansion of the peripheral structure of the sheet laminate 30. Although the mesh 33 suppresses the excessive amplitude of the vibration sheet 32, the mesh 33 is very soft and is merely in contact with the vibration sheet 32, so that the sound wave absorbing function of the vibration sheet 32 is not hindered.
[0026]
The rubber vibration sheet 32 of the sheet laminate 30 is relatively weak against heat. The exhaust gas passing through the first chamber 25 of the attachment box 20 is far lower in temperature (200 to 600 ° C.) than the upstream side of the heat exchanger, but if the vibration sheet 32 is touched as it is, the vibration sheet 32 may deteriorate. There is sex. In this respect, in the apparatus of the embodiment, the vibration sheet 32 is protected from heat as follows. That is, since the first chamber 25 serving as an exhaust passage and the third chamber 27 facing the sheet laminate 30 are partitioned by the partition walls 23 and 24, the sheet laminate 30 is completely exposed to the exhaust gas. Can be prevented. Moreover, since the sheet | seat laminated body 30 has block | closed the opening of the box main body 21, it has the dead end structure of waste gas, and the inflow of waste gas is suppressed. Further, the exhaust gas passage toward the third chamber 27 is bypassed by the openings 23a and 24a formed in the partition walls 23 and 24, and the exhaust gas temperature is lowered during that time. Further, the partition wall 24 facing the third chamber 27 is made of metal, equalizes the temperature in the third chamber 27, and prevents the sheet laminate 30 from being locally exposed to high temperatures.
[0027]
In addition, in this embodiment, the heat-resistant sheet 31 prevents the vibration sheet 32 from being exposed to a high temperature, and the heat-insulating effect of the heat-resistant sheet 31 makes it difficult for heat to be transmitted to the vibration sheet 32. Further, since the through hole 22a is formed in the protective cover 22, and the outside air enters the fourth chamber 28 between the protective cover 22 and the sheet laminated body 30, the sheet laminated body 30 is maintained at a relatively low temperature from this point. can do. In this way, the vibration sheet 32 is protected from heat, and the durability of the vibration sheet 32 can be improved. Since the heat-resistant sheet 31 is laminated on the vibration sheet 32, it can also play a role of suppressing excessive amplitude of the vibration sheet 32. The heat-resistant sheet 31 is extremely thin compared to the vibration sheet 32 and can be deformed following the vibration sheet 32. Therefore, the sound wave absorbing function of the vibration sheet 32 is not unnecessarily suppressed.
[0028]
Further, the vibration suppressing member 50 provided on the inner surface of the protective cover 22 suppresses excessive bending of the sheet laminate 30. That is, when the sheet laminate 30 is greatly bent when the conditions are close to resonance, the central portion (the portion with the largest amplitude) is in contact with the flexible vibration suppressing member 40, so that the vibration suppressing member 40 excessive deflection is suppressed. Thereby, the noise (flapping sound) generated when the sheet laminate 30 hits the protective cover 22 can be prevented.
[0029]
The vibration sheet 32 is rubbery and soft and easily damaged. However, since both surfaces are covered with the heat-resistant sheet 31 and the mesh 33, it is possible to prevent the sheet laminate 30 from being damaged when assembled to the attachment box 20. It becomes easy to handle. Moreover, since the extension part 31a provided in the heat-resistant sheet 31 wraps the peripheral part of the vibration sheet 32 and the mesh 33, it is possible to prevent the peripheral part of the vibration sheet 32 and the mesh 33 from being twisted. Durability can be increased. Moreover, since the frame board 34 is wrapped together in the sheet | seat laminated body 30, sufficient intensity | strength can be maintained and the handling at the time of an assembly | attachment becomes easy. Moreover, since the sheet | seat laminated body 30 is assembled | attached to the frame board 34 which has shape retainability, the adhesiveness to to-be-attached members, such as the attachment box 20 and the protective cover 22, can be made favorable.
[0030]
In addition, when a low temperature atmosphere is guaranteed as the sheet laminate, the heat-resistant sheet may be omitted to have a two-layer structure of the vibration sheet and the mesh, or the mesh may be laminated on both sides of the vibration sheet. . In addition, when the excessive amplitude can be suppressed only by the heat-resistant sheet, a two-layer structure of the heat-resistant sheet and the vibration sheet may be used, or heat-resistant sheets may be laminated on both sides of the vibration sheet.
The frame plate 34 may be easily elastically deformed using a very thin metal plate or the like. In this case, it can also install in the state which curved sheet laminated body 30, and the freedom degree of an installation form increases.
In the above embodiment, a heat insulating pad may be attached to the partition wall 23 to further protect the sheet laminated body from heat.
In the above embodiment, the chimney may be attached to the back wall of the attachment box.
[0031]
Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, components corresponding to those of the preceding embodiment are denoted by the same reference numerals in the drawing, and detailed description thereof is omitted.
In this embodiment, as shown in FIG. 7, an exhaust port 15 </ b> A is provided in the front cover 12 of the housing 10, and an attachment box 20 </ b> A is attached to the front cover 12.
[0032]
The attachment box 20A includes a box body 21A having an open bottom surface, a protective cover 22 (bottom wall of the attachment box) that covers the bottom surface opening of the box body 21A, and an exterior cover 70 that covers the box body 21A from the front (FIG. 7). (Shown only in Fig. 5) and has a rectangular parallelepiped shape. An opening 21c connected to the exhaust port 15A of the housing 10 is formed on the back wall of the box main body 21A, and a connection portion 21d to which the base end portion of the chimney is connected is provided on the upper wall.
[0033]
As shown in FIG. 8, in the attachment box 20A, a horizontal partition wall 23A, a partition wall 24A, and a sheet laminated body 30 are arranged in this order below the opening 21c. Thereby, the space in the attachment box 20A is partitioned into a first chamber 25A, a second chamber 26A, a third chamber 27A, and a fourth chamber 28A. The first chamber 25A is a part of the exhaust passage. The partition wall 23A is supported by the front and back edges of the box body 21A being fixed to the front wall and the back wall, and a gap 23x (pressure transmission path) between the left and right edges and the side wall of the box body 21A when viewed from the front. Is formed. A large number of openings 24x (pressure transmission passages) are formed in the central portion of the partition wall 24A.
[0034]
In the second embodiment, similarly to the first embodiment, sound waves from the first chamber 25A serving as an exhaust passage enter the third chamber 27A through the gap 23x, the second chamber 26A, and the opening 24x, and the sheet laminate 30. Absorbed in. The sheet laminate 30 is arranged with the heat-resistant sheet on the upper side (high temperature side) and the mesh on the lower side (low temperature side).
A heat insulating sheet may be attached to the partition wall 23A as necessary. The partition wall 24A also functions as a soaking plate.
[0035]
The present invention is not limited to the above embodiments, and various modes are possible. For example, the mesh may be embedded in a rubber vibration sheet and laminated. In this case, the embedding position may be the center in the thickness direction of the vibration sheet or may be a surface on one side. Further, the mesh may be bonded over the entire area of the vibration sheet.
The sheet laminate may be fixed by sandwiching a vibration sheet, a mesh, and a heat-resistant sheet between two frame plates. In this case, the heat-resistant sheet does not have an extending portion, and is the same size as the vibration sheet.
The sheet laminate and the protective cover may be formed on the back and side surfaces of the attachment box in the first embodiment, or may be disposed on the front and side surfaces of the attachment box in the second embodiment.
A small box having a structure similar to the attachment box of the above embodiment may be provided in the chimney, or the sheet laminate may be disposed in the exhaust chamber in the housing.
[0036]
【The invention's effect】
As described above, according to the first aspect of the present invention, the rubber-like vibration sheet is protected from heat by the heat-resistant sheet disposed on the exhaust passage side. For a long time. In addition, this heat-resistant sheet can suppress excessive vibration of the vibration sheet and prevent deterioration due to excessive deformation, and can suppress expansion of the size of the peripheral structure. Further, since the heat-resistant sheet is thinner than the vibration sheet and can be deformed together with the vibration sheet, the vibration of the vibration sheet is not excessively suppressed, and the sound wave absorbing function is not hindered.
[0038]
According to the invention of claim 2, since the rubber vibration sheet absorbs sound waves in a relatively wide frequency band, it is possible to prevent the generation of noise. The rubber-like vibration sheet can suppress excessive vibration by the laminated mesh and the heat-resistant sheet, can prevent deterioration due to excessive deformation, and can suppress expansion of the size of the peripheral structure. In addition, since the rubber-like vibration sheet is protected from heat by the heat-resistant sheet disposed on the high temperature side, the vibration sheet is not thermally deteriorated, and a good sound absorption effect is maintained for a long time. Further, since the heat-resistant sheet is thinner than the vibration sheet and can be deformed together with the vibration sheet, the vibration of the vibration sheet is not excessively suppressed, so that the sound absorption function is not hindered.
[0039]
According to the invention of claim 3 , since the rubber vibration sheet and the peripheral edge portion of the mesh are wrapped by the extending portion provided in the heat-resistant sheet, the vibration sheet and the end portion of the mesh are not curled. , Durability increases. In addition, since the diaphragm having an integral structure is configured by wrapping the frame plate together, sufficient strength can be maintained and handling becomes easy.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a gas hot water supply apparatus according to a first embodiment of the present invention.
FIG. 2 is a horizontal sectional view of the attachment box of the apparatus.
FIG. 3 is a schematic perspective view of the attachment box.
FIG. 4 is a cross-sectional view showing a sheet laminated body incorporated in the attachment box with components separated from each other for easy understanding.
FIG. 5 is an enlarged cross-sectional view of a vibration suppressing member incorporated in the attachment box.
FIG. 6 is a perspective view illustrating a method for assembling the sheet laminate.
FIG. 7 is an exploded perspective view of a gas hot water supply apparatus according to a second embodiment of the present invention.
FIG. 8 is a vertical sectional view of the attachment box. FIG. 9 is a schematic perspective view of the attachment box.
[Explanation of symbols]
20, 20A Attachment box (noise prevention device)
22 protective cover 22a through hole 23, 23A, 24, 24A partition wall 23a, 24a, 24x opening (pressure transmission passage)
23x Clearance (pressure wave transmission path)
30 Sheet Laminated Body 31 Heat Resistant Sheet 31a Extension Portion 32 Vibration Sheet 33 Mesh 34 Frame Plate 50 Vibration Suppression Member

Claims (4)

In a noise prevention device for a combustion apparatus, comprising a burner, a heat exchanger disposed above the burner, a housing for accommodating the burner and the heat exchanger, and a chimney connected to an exhaust port of the housing ,
In a space that continues to the exhaust passage downstream of the heat exchanger, a noise prevention sheet laminate is disposed,
The noise prevention sheet laminate is formed by laminating a rubber-like vibration sheet and a heat-resistant sheet made of a resin thinner than this, and only the peripheral edge thereof is fixed, and the heat-resistant sheet faces the exhaust passage side. ,
The noise prevention device for a combustion apparatus, wherein the vibration sheet and the heat-resistant sheet are simply contacted and laminated at all other portions except the peripheral portion. In a noise prevention device for a combustion apparatus, comprising a burner, a heat exchanger disposed above the burner, a housing for accommodating the burner and the heat exchanger, and a chimney connected to an exhaust port of the housing ,
In a space that continues to the exhaust passage downstream of the heat exchanger, a noise prevention sheet laminate is disposed,
The laminated sheet for noise prevention is composed of a rubber vibration sheet, a heat-resistant sheet made of resin thinner than the vibration sheet laminated on one surface side of the vibration sheet, and a flexible material laminated on the other surface side of the vibration sheet. And a mesh having
This noise prevention sheet laminate is fixed only at its peripheral edge, and the heat-resistant sheet faces the exhaust passage,
The noise prevention device for a combustion apparatus, wherein the vibration sheet, the heat-resistant sheet, and the mesh are simply contacted and laminated at all other portions except the peripheral portion. In a noise prevention device for a combustion apparatus, comprising a burner, a heat exchanger disposed above the burner, a housing for accommodating the burner and the heat exchanger, and a chimney connected to an exhaust port of the housing ,
In a space that continues to the exhaust passage downstream of the heat exchanger, a noise prevention sheet laminate is disposed,
The laminated sheet for noise prevention is composed of a rubber vibration sheet, a heat-resistant sheet made of resin thinner than the vibration sheet laminated on one surface side of the vibration sheet, and a flexible material laminated on the other surface side of the vibration sheet. And a mesh having
This noise prevention sheet laminate is fixed only at its peripheral edge, and the heat-resistant sheet faces the exhaust passage,
The noise-preventing sheet is formed by laminating the heat-resistant sheet, the vibration sheet, the mesh, and a ring-shaped frame plate in this order, and an extending portion is provided at the periphery of the heat-resistant sheet. A noise prevention device for a combustion apparatus, wherein the vibration sheet, the peripheral edge of the mesh and the frame plate are wrapped, and the extension portion is fixed to the frame plate in this state. Combustion apparatus characterized by comprising a noise prevention device as claimed in any one of claims 1 to 3.

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