JP2015143588A - Manifold for gas supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manifold for gas supply capable of preventing gas leakage without increasing plate thickness of a lid plate.SOLUTION: At least one part of a plurality of fastening members for fastening a body and a lid plate fasten an outer edge portion of the lid plate to the body. Also, the lid plate is formed by a member whose rigidity is lower than that of the body, and a bent part is formed by bending at least one part of an end part of the outer side of the outer edge portion to the body side. Then, at a place in which the fastening member is adjacent to the bent part, a rigidity lowering part for lowering the rigidity of the outer edge portion and the bent part is provided. Thus, it is suppressed that a fastening force by the fastening member is excessively transmitted to the vicinity portion of the fastening member, and the fastening force can be dispersed in the portion between the fastening members. As a result, in the portion between the fastening members, a force in which the lid plate is pressed against the body by the fastening member increases, and sealing performance is secured, so that gas leakage can be prevented.

Description

  The present invention relates to a gas supply manifold that distributes fuel gas to a plurality of burners of a combustion apparatus.

  Some combustion devices such as water heaters are equipped with a plurality of burners, and the amount of generated heat (hot water supply capacity) can be changed by switching the burners to be burned. Such a combustion apparatus includes a gas supply manifold that distributes supplied fuel gas to a plurality of burners. As the manifold, there are a plurality of main bodies provided with a plurality of nozzles for injecting fuel gas toward the burner and a cover plate covering the opposite side of the main body from the side from which the nozzles protrude, with a seal member interposed therebetween. A structure for fastening with a screw is known, and a fuel gas distribution passage to a nozzle is formed between a main body and a cover plate.

  In such a manifold, if the rigidity of the cover plate is low, the cover plate is easily deformed when fastened with screws, causing gas leakage. Therefore, a structure has been proposed in which the outer edge of the cover plate is bent to increase the rigidity of the cover plate (for example, Patent Document 1).

JP 2003-65507 A

  However, even if the rigidity of the cover plate is increased by bending, there is a problem in that gas leakage may occur from a portion between the screws. Moreover, although such a gas leak becomes difficult to generate | occur | produce by making the board | plate thickness of a cover plate thick, in this, a weight will increase or material cost will become high.

  The present invention has been made in response to the above-mentioned problems in the prior art, and an object thereof is to provide a gas supply manifold capable of preventing gas leakage without increasing the thickness of the cover plate.

In order to solve the above-described problems, the gas supply manifold of the present invention employs the following configuration. That is,
A main body to which a plurality of burners of a combustion device are connected; a lid plate attached to a surface of the main body opposite to the side to which the burners are connected; and a plurality of fastening members for fastening the lid plate to the main body In a gas supply manifold that distributes fuel gas to the plurality of burners using a distribution passage formed between the main body and the lid plate,
At least some of the plurality of fastening members fasten an outer edge portion of the lid plate to the main body,
The lid plate is formed of a member having lower rigidity than the main body, and a bent portion is formed by bending at least a part of the outer end portion of the outer edge portion toward the main body side. ,
Where the fastening member that fastens the outer edge portion of the lid plate and the bent portion are adjacent to each other, a rigidity lowering portion that reduces the rigidity of the outer edge portion and the bent portion is provided. To do.

  In general, when the lid plate is fastened to the main body using a plurality of fastening members, if the rigidity of the lid plate is low, the reaction force received from the main body causes the lid plate to bend between the fastening member and the fastening member. Seal performance cannot be obtained. Therefore, when the cover plate is formed of a member having low rigidity (for example, a sheet metal), measures have been taken to increase the rigidity of the cover plate by increasing the plate thickness or bending the end of the member. It was. If the sealing performance is insufficient even by such countermeasures, the rigidity has been further increased because the countermeasures are still insufficient. However, the inventor of the present application stated that the sealing performance may still be insufficient even when the end of the cover plate is bent, not because the rigidity of the cover plate is not sufficiently increased. It has been found that the tightening force of the fastening member is difficult to be transmitted to the portion between the fastening member and the fastening member. That is, at least a part of the outer edge portion of the lid plate is fastened to the main body by the fastening member, and the end portion that is bent to increase the rigidity of the lid plate is outside the outer edge portion. For this reason, a part of the bent end portion (folded portion) is arranged immediately outside the fastening position by the fastening member. When the end portion is bent to increase the rigidity of the vicinity of the fastening position, the fastening force by the fastening member is easily transmitted. As a result, the force that the lid plate is pressed against the main body by the fastening member increases in the vicinity. This itself improves the sealing performance in the vicinity, but on the other hand, the reaction force that the cover plate receives from the main body also increases. And this reaction force acts in the direction which negates a part of fastening force of a fastening member. For this reason, in the part between a fastening member and a fastening member, the force by which a cover plate is pressed by a fastening member on a main body will be weakened, and as a result, it is thought that it is difficult to obtain the sealing performance of this part. It is done.

  The gas supply manifold according to the present invention is based on such knowledge, and a rigidity lowering portion that reduces the rigidity of the outer edge portion of the lid plate and the bending portion is provided at a location where the fastening member and the bending portion are adjacent to each other. Is provided. According to such a structure, it can suppress that the fastening force by a fastening member transmits excessively to the vicinity part of a fastening member, and can disperse fastening force to the part between a fastening member and a fastening member. As a result, the force with which the cover plate is pressed against the main body by the fastening member is strengthened at the portion between the fastening member and the sealing performance is ensured, so that gas leakage can be prevented.

  In addition, since it is not necessary to increase the thickness of the cover plate, it is possible to reduce the weight of the manifold and reduce the material cost.

  In the above-described gas supply manifold of the present invention, a notch hole penetrating the lid plate may be provided as the rigidity reduction portion.

  In this way, since the rigidity is reduced around the notch hole, it is possible to suppress that the fastening force by the fastening member is excessively transmitted to the vicinity of the fastening member, and at the portion between the fastening member and the fastening member, The force by which the cover plate is pressed against the main body by the fastening member can be increased.

  Further, in the above-described gas supply manifold of the present invention, the notch hole may be provided in the bent portion so that the space between the main body and the cover plate can be visually observed.

  In this way, the notch hole can be used as a window for visually confirming the fastening condition between the main body and the cover plate by the fastening member, so that the cause of gas leakage such as lifting of the fastening member can be found or inspected. Easy to do.

  Further, when inspecting a gas leak by bringing a pilot fire close to the periphery of the gas supply manifold, a slight gas leak is difficult to detect because the leaked fuel gas diffuses. In the manifold for gas supply of the present invention in which a notch hole is provided in the bent part bent to the main body side, leaked fuel gas comes out from the notch hole through the inside of the bent part, so even a slight gas leak is found It becomes easy to do and can raise the precision of a test | inspection.

It is explanatory drawing which shows the structure of the combustion apparatus which makes the water heater 1 the example. It is the perspective view which showed the state which decomposed | disassembled the manifold 6. FIG. 4 is a cross-sectional view of the manifold 6 taken along a plane that passes through a pair of upper and lower nozzles 31 of the main body 30 and is perpendicular to the lid plate 40. It is explanatory drawing which showed the example of the analysis result of the force in which the cover plate 40 presses the sealing member 50 visually. It is explanatory drawing which expanded and showed the notch hole 44 provided in the cover board 40. FIG. It is explanatory drawing which showed the example which cut off the part adjacent to the screw | thread 42 of the bending part 43, and provided the notch part 45. FIG.

  FIG. 1 is an explanatory view showing the structure of a combustion apparatus taking a water heater 1 as an example. As shown in the figure, the water heater 1 includes a combustion housing 5 including a plurality of burners 20 (see FIG. 3) for burning fuel gas, and heat from the combustion housing 5 above the combustion housing 5 with high-temperature combustion gas. A heat exchanger 4 that generates hot water by exchange, a manifold 6 that distributes fuel gas to a plurality of burners 20, and a combustion fan 7 that supplies combustion air to the combustion housing 5 from below are provided. These are housed inside a rectangular parallelepiped outer case 2. The manifold 6 of this embodiment corresponds to the “gas supply manifold” of the present invention.

  An exhaust port 3 for exhausting the combustion exhaust gas that has passed through the heat exchanger 4 is provided in the upper part on the front side of the outer case 2. Further, a water supply pipe 10 for supplying water to the heat exchanger 4 and a hot water supply pipe 11 for supplying hot water generated by the heat exchanger 4 to a currant (not shown) are provided on the bottom surface of the outer case 2. In addition, a gas supply pipe 12 for supplying fuel gas is connected. The fuel gas supplied by the gas supply pipe 12 is supplied to the manifold 6 via a valve unit 9 including an on-off valve and a proportional valve and a gas pipe 8. In FIG. 1, illustration of the water supply and hot water supply pipes in the outer case 2 is omitted.

  FIG. 2 is a perspective view showing a state where the manifold 6 is disassembled. The manifold 6 includes a main body 30 to which a plurality of burners 20 are connected, a lid plate 40 that covers the side of the main body 30 opposite to the side to which the burners 20 are connected, and a seal that is sandwiched between the main body 30 and the lid plate 40. The member 50 is provided. The main body 30 is formed by a die-casting method using a metal material such as an aluminum alloy, and a plurality of nozzles 31 (see FIG. 3) for injecting fuel gas toward the burner 20 are provided in pairs (19 in the illustrated example). Set) is provided. In the manifold 6 of this embodiment, the plurality of sets of nozzles 31 are divided into four groups. Correspondingly, four concave portions 33 defined by ribs 32 are provided on the surface of the main body 30 on the lid plate 40 side, and the nozzle 31 communicates with the bottom surface of the concave portion 33. In addition, in the illustrated four recessed parts 33, the number of the nozzles 31 to include is mutually different. A gas passage 34 into which the fuel gas from the gas pipe 8 flows is formed below the four recesses 33, and each recess 33 communicates with the gas passage 34 via the gas flow holes 35.

  The lid plate 40 is formed by pressing a metal flat plate, and a protruding portion 41 that protrudes toward the opposite side of the main body 30 is formed in a portion facing the four concave portions 33 and the gas passage 34 of the main body 30. Is formed. Further, the seal member 50 is formed in a sheet shape using an elastic material such as rubber, and a portion of the main body 30 facing the four recesses 33 and the gas passages 34 is cut out to surround the recesses 33 and the gas passages 34. It has a shape. When assembling the manifold 6, the cover plate 40 is fastened by using a plurality of screws 42 so as to press the seal member 50 against the main body 30. The screw 42 of this embodiment corresponds to the “fastening member” of the present invention.

  FIG. 3 is a cross-sectional view of the manifold 6 taken along a plane that passes through the pair of upper and lower nozzles 31 of the main body 30 and is perpendicular to the cover plate 40. As shown in the figure, a nozzle 31 projects from the surface of the main body 30 opposite to the cover plate 40 toward the burner 20. Inside the manifold 6, a distribution passage 55 is formed by the concave portion 33 of the main body 30 and the raised portion 41 of the lid plate 40, and fuel gas is supplied to each nozzle 31 through the distribution passage 55. The fuel gas ejected from the nozzle 31 flows in from a pair of upper and lower gas inlets 21 of the burner 20 while entraining combustion air, and the mixed gas is combusted at the flame port 22 opened at the upper end of the burner 20. The burner 20 is provided for each pair of upper and lower nozzles 31 of the main body 30.

  The main body 30 is provided with an electromagnetic valve 36 that opens and closes a gas flow hole 35 that communicates the recess 33 and the gas passage 34 with each of the four recesses 33 (distribution passages 55). It is possible to change the hot water supply capacity and the like depending on which distribution passage 55 is supplied with fuel gas by controlling the opening and closing of these four solenoid valves 36.

  In the manifold 6 in which the main body 30 and the cover plate 40 are combined to form the fuel gas distribution passage 55 as described above, the rigidity of the metal plate cover plate 40 is lower than that of the die-cast main body 30, and the screw 42 If deformation such as bending occurs in the cover plate 40 when fastened at, a gas leak will occur. Therefore, as shown in FIG. 3, the upper and lower edges of the cover plate 40 are bent, and a bent portion 43 is provided on the main body 30 side to increase the rigidity of the cover plate 40.

  However, even if the bent portion 43 is provided in the cover plate 40, gas leakage may occur from a portion between the screw 42 and the screw 42. This is thought to be due to the following reasons. First, when the sealing member 50 is sandwiched between the main body 30 and the lid plate 40 and fastened with the screws 42, the fastening force by the screws 42 is applied to the lid plate 40, and the lid plate 40 presses the sealing member 50 toward the main body 30. To do. Since the sealing performance is exhibited by this pressing force, gas leakage occurs when there is a portion where the pressing force is weak.

  FIG. 4 is an explanatory diagram visually showing an example of the analysis result of the force with which the cover plate 40 presses the seal member 50. In the figure, the upper edge side of the cover plate 40 provided with the bent portion 43 is shown enlarged. In the figure, the portion with fine hatching indicates that the force (pressing force) by which the cover plate 40 presses the seal member 50 is strong. The rougher the hatching, the weaker the pressing force is, and no hatching is applied. The part represents that the pressing force is weak.

  In the illustrated example, the pressing force is strong in the vicinity of the screw 42, whereas the pressing force is weak in the portion between the screw 42 and the screw 42. The reason is considered as follows. First, by providing the bent portion 43 on the upper edge side of the cover plate 40, the rigidity in the vicinity of the screw 42 is increased and the fastening force by the screw 42 is easily transmitted. As a result, the pressing force is applied in the vicinity of the screw 42. To increase. This itself improves the sealing performance in the vicinity of the screw 42, but on the other hand, the reaction force that the cover plate 40 receives from the sealing member 50 also increases, and this reaction force is a part of the fastening force of the screw 42. Acts in the direction of canceling. For this reason, in the part between the screw 42 and the screw 42, the pressing force is weakened, the sealing performance is insufficient, and gas leakage occurs. In addition, although the uneven pressing force is alleviated by increasing the thickness of the cover plate 40, it is difficult to obtain advantages such as weight reduction and material cost reduction by forming the cover plate 40 with sheet metal. End up. Therefore, in the manifold 6 of this embodiment, instead of increasing the plate thickness of the cover plate 40, a notch hole 44 penetrating the cover plate 40 is provided.

  FIG. 5 is an explanatory diagram showing an enlarged view of the cutout hole 44 provided in the lid plate 40. As shown in the perspective view of FIG. 5A, the notch hole 44 is on the bent portion 43 side at the fastening position of the screw 42. In this embodiment, the notch 44 is notched at the corner portion where the bent portion 43 is bent. The hole 44 penetrates. If such a cut-out hole 44 is provided, the rigidity of the vicinity of the screw 42 of the cover plate 40 is reduced as compared with the case where the cut-out hole 44 is not provided. It is possible to suppress the excessive transmission to the part and to disperse the fastening force in the part between the screw 42 and the screw 42. As a result, the pressing force is increased at the portion between the screw 42 and the screw 42, and the sealing performance is ensured, so that gas leakage can be prevented.

  Further, it is only necessary to provide the notch 44 in the lid plate 40, and it is possible to reduce the weight of the manifold 6 and reduce the material cost compared to the case where the plate thickness of the lid plate 40 is increased.

  Further, as shown in FIG. 5B, when the manifold 6 is viewed from the bent portion 43 side, the cutout hole 44 of this embodiment is formed in the bent portion 43 so that the space between the main body 30 and the cover plate 40 can be visually observed. Is provided. By doing so, the notch hole 44 can be used as a window for visually confirming the fastening state of the main body 30 and the cover plate 40 by the screw 42, so that the cause of gas leakage such as the lifting of the screw 42 is discovered or inspected. It becomes easy to do.

  In addition, as a gas leak inspection, there is a method in which a seed fire is brought close to the periphery of the manifold 6, but in the case of a slight gas leak, the leaked fuel gas diffuses and does not lead to ignition and is difficult to detect. . In the manifold 6 of the present embodiment, the leaked fuel gas passes through the inside of the bent portion 43 and comes out of the cutout hole 44, so that even a slight gas leak can be easily found and the accuracy of inspection can be improved.

  Although the manifold 6 of the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof.

  For example, in the manifold 6 of the above-described embodiment, the cutout hole 44 penetrating the lid plate 40 is provided in the bent portion 43, but it may be provided in a plane portion between the bent portion 43 and the screw 42. Further, instead of the cutout hole 44, as shown in FIG. 6, a portion adjacent to the screw 42 of the bent portion 43 may be cut out to provide the cutout portion 45. Furthermore, the rigidity may be lowered by providing a portion where the plate thickness of the cover plate 40 is reduced not at the notch but at a location where the screw 42 and the bent portion 43 are adjacent to each other. Even in these cases, the fastening force by the screw 42 can be suppressed from being excessively transmitted to the vicinity of the screw 42, and the pressing force can be increased at the portion between the screw 42 and the screw 42. Note that the notched hole 44, the notched portion 45, and the portion where the plate thickness of the lid plate 40 is reduced correspond to the “rigidity reduced portion” of the present invention.

  The positions where the bent portions 43 are provided are not limited to the upper and lower edges of the cover plate 40, and the bent portions 43 may be provided on the left and right side edges.

1 ... Water heater, 2 ... Exterior case, 3 ... Exhaust port,
4 ... Heat exchanger, 5 ... Combustion enclosure, 6 ... Manifold,
7 ... Combustion fan, 8 ... Gas piping, 9 ... Valve unit,
10 ... Water supply pipe, 11 ... Hot water supply pipe, 12 ... Gas supply pipe,
20 ... Burner, 21 ... Gas inlet, 22 ... Flame,
30 ... Main body, 31 ... Nozzle, 32 ... Rib,
33 ... recess, 34 ... gas passage, 35 ... gas flow hole,
36 ... Solenoid valve, 40 ... Cover plate, 41 ... Raised part,
42 ... screw, 43 ... bent part, 44 ... notch,
45 ... notch, 50 ... seal member, 55 ... distribution passage.

Claims (3)

A main body to which a plurality of burners of a combustion device are connected; a lid plate attached to a surface of the main body opposite to the side to which the burners are connected; and a plurality of fastening members for fastening the lid plate to the main body In a gas supply manifold that distributes fuel gas to the plurality of burners using a distribution passage formed between the main body and the lid plate,
At least some of the plurality of fastening members fasten an outer edge portion of the lid plate to the main body,
The lid plate is formed of a member having lower rigidity than the main body, and a bent portion is formed by bending at least a part of the outer end portion of the outer edge portion toward the main body side. ,
Where the fastening member that fastens the outer edge portion of the lid plate and the bent portion are adjacent to each other, a rigidity lowering portion that reduces the rigidity of the outer edge portion and the bent portion is provided. Manifold for gas supply. The gas supply manifold according to claim 1,
A gas supply manifold characterized in that a notch hole penetrating the lid plate is provided as the rigidity reduction portion. The gas supply manifold according to claim 2,
The gas supply manifold, wherein the cutout hole is provided in the bent portion so that a space between the main body and the lid plate can be visually observed.

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