JP3631516B2 - Combustion equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a combustion apparatus, and more particularly to an improvement in a resonance prevention structure.
[0002]
[Prior art]
In a general gas combustion apparatus for hot water supply, when a combination of factors such as the thickness and length of the chimney, the volume of the casing, and the combustion characteristics of the burner satisfies the resonance condition, resonance of the combustion noise occurs and low frequency (30 ~80H _Z) big noise occurs. In order to prevent this noise generation, Japanese Utility Model Laid-Open No. 5-45438 is equipped with a resonance box. The resonance box communicates with the casing via a sound pressure transmission passage above the heat exchanger. This resonance box receives the combustion sound generated in the casing through the sound pressure transmission passage and emits a sound having a phase opposite to that of the combustion sound, thereby preventing resonance of the combustion sound and thus trying to eliminate the noise. Yes.
[0003]
[Problems to be solved by the invention]
In the combustion apparatus of the above publication, noise can be eliminated by installing a resonance box. However, for example, if the chimney length is significantly changed compared to the planned length, there is a possibility that resonance noise will be generated. there were.
[0004]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the invention of claim 1 is directed to a combustion apparatus in which a resonance box is connected to a casing containing a burner via a sound pressure transmission passage. A diaphragm is accommodated in the box, and the diaphragm is fixed to the resonance box only at substantially the center of both side edges, and the upper and lower parts thereof can vibrate.
A second aspect of the present invention, in the combustion apparatus according to claim 1, said sound pressure transmission passage is disposed above the burner, the upper part of the diaphragm is arranged to face to the sound pressure transmission passage It is characterized by being.
According to a third aspect of the present invention, in the combustion apparatus according to the first or second aspect , the resonance box has a thin rectangular box shape, the vibration plate is formed of a single thin plate, and the resonance box is disposed at an intermediate portion in the thickness direction of the resonance box. A vibrating portion that is arranged and vibrates, a pair of extending portions that extend from substantially the center of both side edges of the vibrating portion along the same plane as the vibrating portion, and a direction orthogonal to the extending portion from the distal ends of these extending portions And a pair of attachment portions extending in the direction, and these attachment portions are fixed to both side walls of the resonance box.
According to a fourth aspect of the present invention, in the combustion apparatus according to the third aspect , the diaphragm further includes an extending portion extending along the same plane as the vibrating portion from the upper and lower sides of both side edges of the vibrating portion. And a support portion extending in a direction orthogonal to the extension portion from the tip of the extension portion, and these support portions are in contact with both side walls of the resonance box in a state having play in the thickness direction of the resonance box. And
[0005]
[Action]
According to the first aspect of the present invention, the diaphragm is accommodated in the resonance box, and the diaphragm vibrates in response to the burner combustion noise. Therefore, even if the combustion apparatus has a significant structural change, resonance is prevented. Can do. Further, since the diaphragm is fixed only at substantially the center of both side edges and the upper and lower parts vibrate, the vibration of the diaphragm is further facilitated, and resonance can be prevented more reliably.
In the invention of claim 2 , since the upper part of the diaphragm is opposed to the sound pressure transmission passage disposed above the burner, resonance is surely prevented even when there is a significant structural change in the exhaust system of the combustion device. can do.
In the invention of claim 3, since the vibration part, the extension part, and the attachment part are formed by a single thin plate, the configuration is simple, and the press part can be manufactured at a low cost. In addition, since the vibrating portion can swing with the extended portion as a fulcrum, the vibration plate can be easily vibrated, and resonance can be prevented more reliably.
In the invention of claim 4 , the vibration portion can be maintained in the middle portion in the thickness direction of the resonance box over the entire area by the pair of upper and lower support portions, and good vibration in the vibration portion can be ensured. As a result, the resonance prevention effect can be further enhanced.
[0006]
【Example】
As shown in FIG. 1, the combustion apparatus includes a casing 10. The casing 10 includes a first case portion 11, a second case portion 12, and a third case portion 13 that are arranged in order from the bottom. A fan 20 is attached to the bottom wall of the first case portion 11. A burner 30 and a nozzle holder 40 are accommodated in the first case portion 11. In the first case portion 11, the space below the burner 30 is an air chamber 15. A heat exchanger 50 is attached to the upper end portion of the second case portion 12. A space between the burner 20 and the heat exchanger 50 is a combustion chamber 16 in the first case portion 11 and the second case portion 12. Further, an exhaust port 17 is formed at the upper end of the third case portion 13, and a chimney 60 is connected to the exhaust port 17. The casing 10 and the fan 20 are covered with a cover 70.
[0007]
In the above configuration, gas is injected from the nozzle portion 41 of the nozzle holder 40 and supplied to the inlet of the burner 30. On the other hand, the air is sent into the air chamber 15 of the casing 10 by the rotation of the fan 20, and this air is also supplied to the inlet of the burner 30. The gas and air supplied to the inlet of the burner 30 are mixed in the burner 30, injected from the flame port formed on the upper surface thereof, and burned. The heat exchanger 50 is heated by this combustion heat. A pipe 51 is wound around the heat exchanger 50, and water passing through the pipe 51 is heated by the heat exchanger 50 to become hot water. The combustion exhaust gas passes through the third case portion 13 through the heat exchanger 50 and is discharged from the chimney 60.
[0008]
Next, features of the present invention will be described. As shown in FIG. 1, a resonance box 80 having a flat rectangular box shape is disposed in the cover 70 next to the casing 10 (on the back side). The upper end portion of the resonance box 80 communicates with the third case portion 13 of the casing 10 via the sound pressure transmission passage 85 and communicates with the air chamber 15 of the first case portion 11 of the casing 10 via the air introduction passage 86. Communicate. Inside the resonance box 80 is housed a thin plate (thickness of 1 mm or less, for example, about 0.3 mm) diaphragm 90. This diaphragm 90 is fixed to the resonance box 80 only at the center of both side edges, and its upper end faces the sound pressure transmission passage 85.
[0009]
As shown in FIG. 2, the resonance box 80 includes a body 81 formed by pressing a thin plate (thickness of 1 mm or less) with a shallow drawing, and a back plate 82 that covers the back side of the body 81. A resonance space 83 is formed inside. As shown in FIGS. 2 and 3, the body 81 includes a front wall 81a having a flat rectangular shape, side walls 81b and upper and lower walls 81c orthogonal to the front wall 81, and flanges extending outward from the walls 81b and 81c. 81d. The back plate 82 is fixed to the flange 81d.
[0010]
As shown in FIGS. 2 and 3, a convex portion 81 x protruding toward the casing 10 is formed at the upper end portion of the front wall 81 a. The convex portion 81x extends in the width direction of the resonance box 80, and a long and narrow opening 81y is formed at the tip. A hole 81z is formed at the center of the lower end of the front wall 81a. As shown in FIG. 1, the body 81 of the resonance box 80 is fixed to the casing 10 via a bracket (not shown). In this fixed state, the convex portion 81 x of the resonance box 80 is the third case portion of the casing 10. 13, the opening 81 y matches the opening (not shown) having the same shape formed in the third case portion 13. As a result, the internal space of the convex portion 81x functions as the sound pressure transmission passage 85. One end of the pipe 100 is fixed to the hole 81z of the resonance box 81, and the other end of the pipe 100 is fixed to a hole formed in the back wall of the first case portion 11. As a result, the internal space of the pipe 100 functions as the air introduction passage 86.
[0011]
As best shown in FIG. 4, the vibration plate 90 is formed by pressing the thin plate. The vibration portion 91 has a rectangular vibration portion 91 and both upper and lower ends in the both side edges of the vibration portion 91. An extending portion 92 extending in the width direction and the outward direction along the same plane as the vibrating portion 91 from the center, a mounting portion 93 formed at the tip of the pair of central extending portions 92, and a pair of upper and lower extending portions And a support portion 94 formed at the tip of 92. The attachment portion 93 and the support portion 94 have the same shape and are orthogonal to the vibration portion 91 and the extension portion 92. In addition, a circular opening 95 is formed at the center of the vibration part 91.
[0012]
The diaphragm 90 is fixed to the body 81 by fixing the pair of attachment portions 93 of the diaphragm 90 to both side walls 81b of the body 81 of the resonance box 80 by means such as spot welding. The upper and lower support portions 94 are in contact with the side wall 81b and are not fixed. In a state where the vibration plate 90 is accommodated in the resonance box 80, the vibration part 91 of the vibration plate 90 is parallel to the front wall 81a and the back plate 82 of the resonance box 80, and is located at the approximate center between the two. . The support portion 94 is arranged with a slight play between the front wall 81a and the back plate 82, whereby the vibration portion 91 is arranged in the central portion in the thickness direction of the resonance box 80 over the entire area. The state is maintained.
[0013]
As described above, the upper end portion of the vibration portion 91 of the diaphragm 90 is disposed so as to face the sound pressure transmission passage 85, and the lower edge of the vibration portion 91 is disposed above the air introduction passage 86. Has been.
[0014]
Next, the operation of the resonance box 80 and the diaphragm 90 will be described in detail. The combustion sound of the burner 30 is transmitted to the resonance box 80 via the sound pressure transmission passage 85. In the resonance box 80, a sound wave having a phase opposite to that of the transmitted combustion sound is generated, and the energy of the combustion sound is lost. At this time, the vibration plate 90 accommodated in the resonance box 80 vibrates in response to the combustion sound sensitively, thereby generating a sound wave having an opposite phase (or out of phase) with the combustion sound, Resonance of combustion noise can be reliably prevented. Moreover, even if the structure of the combustion device is significantly changed, the resonance can be reliably prevented.
[0015]
In this embodiment, the vibration plate 90 is fixed only at the center of both side edges, the upper and lower parts vibrate freely, and the pair of extension parts in the center vibrate as fulcrums, so that the vibration is performed well. Thus, the resonance prevention effect can be further enhanced.
In addition, since the upper end portion of the vibration portion 91 of the diaphragm 90 faces the sound pressure transmission passage 85, the resonance prevention effect is further enhanced particularly for the chimney length change (exhaust system structure change). be able to.
In the present embodiment, the pressurized air in the air chamber 15 is introduced into the resonance box 80 from the air introduction passage 86 and passes through the sound pressure introduction passage 86 to the third case portion 13. By this air flow, it is possible to prevent the combustion exhaust gas containing moisture from entering the resonance box 80, and as a result, corrosion of the resonance box 80 and the diaphragm 90 can be prevented.
[0016]
The present invention is not limited to the above-described embodiments, and various modes are possible. For example, the fan may be provided above the heat exchanger and supply air to the air chamber by suction.
[0017]
【The invention's effect】
As described above, according to the first aspect of the present invention, by using the vibration of the diaphragm accommodated in the resonance box, resonance can be prevented even if the combustion apparatus has a significant structural change. In addition, the vibration of the diaphragm is excellent, and resonance can be prevented more reliably.
According to the second aspect of the present invention, resonance can be surely prevented even when there is a significant structural change in the exhaust system of the combustion device.
In the invention of claim 3 , the configuration is simple and the manufacturing cost is low. In addition, the vibration of the diaphragm is excellent, and resonance can be prevented more reliably.
In the invention of claim 4 , the state in which the vibration part is arranged in the middle part in the thickness direction of the resonance box can be maintained over the entire region, and good vibrations in the vibration part can be secured, and consequently the resonance prevention effect is enhanced. Can do.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of a combustion apparatus according to the present invention.
FIG. 2 is a side view of a resonance box equipped in the combustion apparatus.
FIG. 3 is a front view of the resonance box.
FIG. 4 is a perspective view of a diaphragm housed in the resonance box.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Casing 15 ... Air chamber 20 ... Fan 30 ... Burner 40 ... Nozzle holder 50 ... Heat exchanger 80 ... Resonance box 85 ... Sound pressure transmission path 90 ... Diaphragm 91 ... Vibration part 92 ... Extension part 93 ... Attachment part 94 … Support part

Claims (4)

In a combustion apparatus in which a resonance box is connected to a casing containing a burner via a sound pressure transmission passage, a diaphragm is accommodated in the resonance box , The combustion apparatus is characterized in that the diaphragm is fixed to the resonance box only at substantially the center of both side edges, and the upper and lower parts thereof can vibrate . The combustion apparatus according to claim 1 , wherein the sound pressure transmission passage is disposed above the burner, and an upper portion of the diaphragm is disposed to face the sound pressure transmission passage. The resonance box has a thin rectangular box shape, and the vibration plate is formed of a single thin plate. The vibration portion is arranged in the middle portion in the thickness direction of the resonance box and vibrates, and substantially central portions on both side edges of the vibration portion. A pair of extending portions extending along the same plane as the vibrating portion, and a pair of mounting portions extending from the ends of the extending portions in a direction orthogonal to the extending portion, and these mounting portions are provided on the resonance box. The combustion apparatus according to claim 1 or 2 , wherein the combustion apparatus is fixed to both side walls. Further, the diaphragm includes an extending portion extending along the same plane as the vibrating portion from the upper and lower sides of both side edges of the vibrating portion, and a support portion extending in a direction orthogonal to the extending portion from the tip of the extending portion. The combustion apparatus according to claim 3 , wherein the support portions are in contact with both side walls of the resonance box in a state having play in the thickness direction of the resonance box.

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