EXHAUST PORT MEMBER

Abstract

Provided is an exhaust port member (7) having an inlet port (811) into which combustion exhaust gas flows; an exhaust port (77) through which the combustion exhaust gas is discharged to an outside; an exhaust passage (P) in which the combustion exhaust gas flows from the inlet port (811) toward the exhaust port (77); and a space part (9) which is located adjacent to a downstream end exhaust passage part (Pz) positioned at a downstream end of the exhaust passage (P) via a partition wall (781) defining the downstream end exhaust passage part (Pz), wherein the space part (9) has an upstream opening (90) on an upstream side thereof, the combustion exhaust gas flowing through the exhaust passage (P) flows into the space part (9) through the upstream opening (90), and the space part (9) is closed except for the upstream opening (90).

Claims

1. An exhaust port member applied to a combustion device installed outdoors, the exhaust port member comprising: an inlet port into which combustion exhaust gas generated in the combustion device flows; an exhaust port which is located outside an outer casing of the combustion device and through which the combustion exhaust gas is discharged to an outside; an exhaust passage in which the combustion exhaust gas flows from the inlet port toward the exhaust port; and a space part which is located adjacent to a downstream end exhaust passage part positioned at a downstream end of the exhaust passage via a partition wall defining the downstream end exhaust passage part, wherein the space part has an upstream opening on an upstream side thereof, the combustion exhaust gas flowing in the exhaust passage flows into the space part through the upstream opening, and the space part is closed except for the upstream opening.

2. The exhaust port member according to claim 1, wherein the exhaust passage extends in a front-back direction and has the exhaust port at a front end thereof, the partition wall has an upper partition wall defining the downstream end exhaust passage part, the space part has an upper space part which is located above and adjacent to the downstream end exhaust passage part via the upper partition wall, the upper space part has the upstream opening on an upstream side thereof, the combustion exhaust gas flowing in the exhaust passage flows into the upper space part through the upstream opening, and the upper space part is closed except for the upstream opening.

3. The exhaust port member according to claim 2, wherein the upper partition wall is inclined upward toward the exhaust port.

4. The exhaust port member according to claim 2, wherein a passage cross-sectional area of the upper space part is greater than or equal to a passage cross-sectional area of the downstream end exhaust passage part.

5. The exhaust port member according to claim 2, wherein the upper partition wall at a peripheral edge of the exhaust port has a recess portion recessed backward from an opening upper edge of the exhaust port, and the downstream end exhaust passage part expands upwardly at the opening upper edge of the exhaust port.

6. The exhaust port member according to claim 2, wherein the exhaust passage has a first exhaust passage extending in an up-down direction and a second exhaust passage extending in the front-back direction connected to each other, the first exhaust passage has the inlet port at a lower end thereof and a first opening at an upper end thereof, the second exhaust passage has a second opening communicating with the first opening of the first exhaust passage and the exhaust port at a front end thereof, and the second exhaust passage has a bulging portion bulging backward from a connection portion of the first exhaust passage and the second exhaust passage.

7. The exhaust port member according to claim 1, wherein the exhaust passage extends outward from the outer casing, the partition wall is a peripheral partition wall defining the downstream end exhaust passage part, the space part has a surrounding space part located adjacent to the downstream end exhaust passage part via the peripheral partition wall so as to surround an entire circumference of the downstream end exhaust passage part, the surrounding space part has the upstream opening on an upstream side thereof, the combustion exhaust gas flowing in the exhaust passage flows into the surrounding space part through the upstream opening, and the surrounding space part is closed except for the upstream opening.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is a schematic perspective view illustrating a combustion device according to a first embodiment of the present invention;

[0017] FIG. 2 is a schematic perspective view illustrating the combustion device according to the first embodiment of the present invention;

[0018] FIG. 3 a schematic partial longitudinal sectional view illustrating the combustion device according to the first embodiment of the present invention;

[0019] FIG. 4 is a schematic partial sectional view illustrating a main body of an exhaust port member as viewed from a back side according to the first embodiment of the present invention;

[0020] FIG. 5 is a schematic perspective view illustrating an exhaust passage forming member of the exhaust port member according to the first embodiment of the present invention;

[0021] FIG. 6 is a schematic enlarged partial sectional view illustrating the exhaust port member according to the first embodiment of the present invention;

[0022] FIG. 7 is a schematic longitudinal sectional view illustrating the combustion device according to a second embodiment of the present invention; and

[0023] FIG. 8 is a schematic enlarged partial sectional view illustrating the exhaust port member according to the second embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

First Embodiment

[0024] Hereinafter, referring to drawings, an exhaust port member according to an embodiment of the present invention will be described. As illustrated in FIGS. 1 and 2, as a water heater, a combustion device 1000 to which the exhaust port member 7 of the present embodiment is applied is installed outdoors. The combustion device 1000 has an outer casing 100 and a combustion device main body 1 housed in the outer casing 100.

[0025] The outer casing 100 includes a rectangular box-shaped casing body 101 having a front opening 103 opening frontward and a front cover 102 closing the front opening 103. Note that in the present specification, a side on which the front cover 102 is provided is referred to as a front side, and when viewed from the front side, a depth direction of the outer casing 100 is referred to as a front-back direction, a width direction of the outer casing 100 is referred to as a left-right direction, and a height direction of the outer casing 100 is referred to as an up-down direction. Each of the casing body 101 and the front cover 102 is formed by molding a sheet metal into a predetermined shape. The casing body 101 has an upper plate 110, a lower plate 111, a left plate 112, a right plate 113, and a back plate 114.

[0026] As illustrated in FIGS. 2 and 3, the combustion device main body 1. comprises: a burner 2 which ejects a mixture gas of fuel gas and air downward for combustion to generate combustion exhaust gas; a combustion box 3 which is disposed on a lower side of the burner 2 so as to surround a combustion space for the burner 2; and an exhaust duct 4 in which the combustion exhaust gas discharged from the combustion box 3 flows.

[0027] The burner 2 is provided with: a box-shaped burner body 21 which opens downward; and a combustion plate 22 which covers a downward opening surface of the burner body 21. The burner body 21 has, on an upper portion thereof, a burner inlet port 23 which opens sideways. Thus, the mixture gas is supplied from a fan 26 through the burner inlet port 23 into the burner body 21. Then, the mixture gas is ejected downward from a mixture gas ejection portion 24 disposed in the combustion plate 22, thereby performing totally primary air combustion. Note that the combustion plate 22 has a large opening in a central: portion thereof. Textile fabric 24a of heat-resistant fibers is mounted into this opening, and a distribution plate 24b having a multiplicity of distribution holes is overlapped with the textile fabric 24a. In this manner, the mixture gas ejection portion 24 is constituted by the textile fabric 24a and the distribution plate 24b.

[0028] The combustion box 3 is constituted by: an upper box 31 which is open on both upper and lower surfaces and which is fastened, at an upper end portion thereof, to a periphery of a lower surface of the burner body 21; and a lower box 33 which is blocked at both upper and lower surfaces and which has an upper plate portion 33a to be fastened to a lower end of the upper box 31. A front portion of the upper plate portion 33a of the lower box 33 is provided with a vent hole 34 which brings into communication an inside space of the upper box 31 and an inside space of the lower box 33. Further, a back surface of the lower box 33 of the combustion box 3 is provided with an outlet port 35 through which the combustion exhaust gas flows out. It is thus so arranged that the combustion exhaust gas flows from the inside of the upper box 31 through the vent hole 34, the inside of the lower box 33, and the outlet port 35 into the exhaust duct 4.

[0029] The heat exchanger 30 is constituted by: a main heat exchanger 301 (a sensible heat exchanger) of fin-and-tube type which is disposed in the upper box 31 and which is made up of a plurality of heat-absorbing fins 301a, and a plurality of heat-absorbing pipes 301b which penetrates through the heat-absorbing fins 301a; and a subsidiary heat exchanger 302 (a latent heat exchanger) which is disposed in the lower box 33 and which is made up of a plurality of upper and lower heat-absorbing pipes 302b elongated in a meandering manner in the left-right direction. After water is heated by the subsidiary heat exchanger 302, the water is further heated by the main heat exchanger 301 and hot water at a predetermined temperature is supplied to a hot Water supplying terminal (not illustrated).

[0030] The exhaust duct 4 is made of resin. The exhaust duct 4 includes: a riser duct section 42 having a duct inlet port 41 at a lower front surface connected to the outlet port 35 and elongated in the up-down direction; and a bent section 43 bent frontward from an upper end of the riser duct section 42 and extending upward toward a later-described supply-exhaust opening 120 formed in the upper plate 110 of the casing body 101.

[0031] The supply-exhaust opening 120 opens at a central portion of the upper plate 110 of the casing body 101 in the front-back and left-right directions. Further, a supply opening 121 opens in a left region of the upper plate 110 of the casing body 101. Above the supply-exhaust opening 120, there is provided an exhaust connecting portion 50 which is connectable to a later-described exhaust port member 7 and a first air supply connection portion 51 which encloses the exhaust connection portion 50 from radially outside. Further, a second air supply connection portion 57 is provided above the supply opening 121. Each of the exhaust connection portion 50 and the first air supply connection portion 51 is open upward and downward.

[0032] The exhaust connection portion 50 is formed of a tube member extending in the up-down direction. A lower end of the exhaust connection portion 50 is connected to an upper end of the bent section 43 of the exhaust duct 4. The exhaust connection portion 50 stands from an upper surface of the bent section 43 of the exhaust duct 4. An upper end portion of the exhaust connection portion 50 is connected to the exhaust port member 7.

[0033] An upper end opening of the bent section 43 of the exhaust duct 4 faces the exhaust connection portion 50 from below. The exhaust connection portion 50 communicates with the exhaust duct 4. The second air supply connection portion 57 is open downward. A lid member 58 is attached onto an upper surface of the second air supply connection portion 57. Although not illustrated, in case an air supply pipe of two-pipe system is used, an air supply pipe is connected to the second air supply connection portion 57 in a state of having removed the lid member 58. Note that when external air is supplied into the outer casing 100 through the first air supply connection portion 51, the second air supply connection portion 57 may not be provided.

[0034] An air supply box 60 which is in communication with the first and second air supply connection portions 51, 57 is provided along a lower surface of the upper plate 110 of the casing body 101. Although not illustrated, at a right front portion of a bottom plate of the air supply box 60, there is formed an air supply opening which supplies, into an inner space of the outer casing 100, the air flowing from one or both of the first and second air supply connection portions 51, 57.

[0035] The exhaust port member 7 is disposed above the upper plate 110 of the casing body 101 so as to cover the entire upper plate 110. FIG. 4 is a cross-sectional view in the left-right direction of a front portion of a main body 70 of the exhaust port member 7 as viewed from a back side, FIG. 5 is a schematic perspective view of an exhaust passage forming member 80 of the exhaust port member 7, and FIG. 6 is a schematic enlarged partial sectional view of the exhaust port member 7 in the front-back direction. As illustrated in FIGS. 3 to 6, the exhaust port member 7 has: the substantially rectangular box-shaped main body 70 constituting an outer shell of the exhaust port member 7; and the substantially T-shaped exhaust passage forming member 80 housed in the main body 70. The main body 70 has a main body front wall 71, a main body back wall 72, a main body left wall 73, a main body right wall 74, and a main body upper wall 75, and is open downward. Each of the main body 70 and the exhaust passage forming member 80 is made of resin.

[0036] The main body front wall 71 has: an inclined portion 710 inclined downward toward the front side from a front end of the rectangular main body upper wall 75; a folded portion 711 which hangs downward from a lower end of the inclined portion 710 and which is folded upward; and a front cover portion 712 connected to a front end of the folded portion 711. An exhaust port 77 flat in the left-right direction opens at the inclined portion 710 of the main body front wall 71. Air introduction ports 73a, 74a flat in the front-back direction respectively open at lower portions of the main body left and right walls 73, 74. The exhaust port 77 communicates with the exhaust duct 4 in the outer casing 100 through an exhaust passage P formed by the exhaust passage forming member 80 and the exhaust connection portion 50. When the fan 26 is operated in a combustion operation, air outside the combustion device 1000 is taken into the exhaust port member 7 through the air introduction ports 73a, 74a and a gap between the main body 70 of the exhaust port member 7 and the upper plate 110 of the casing body 101. Then, the taken air is supplied into the outer casing 100 via the first air supply connection portion 51. Further, the combustion exhaust gas flown out from the exhaust duct 4 is discharged to the outside from the exhaust port 77 located outside the outer casing 100 through the exhaust passage P formed by the exhaust passage forming member 80.

[0037] A downstream end tubular portion 78 flat in the left-right direction extending backward from a back surface of the inclined portion 710 of the main body front wall 71 is integrally formed with the main body 70 at a peripheral edge of the exhaust port 77. Therefore, a peripheral wall of the downstream end tubular portion 78 defines a downstream end exhaust passage part Pz positioned at a downstream end of the exhaust passage P. The downstream end tubular portion 78 has an upper wall portion 781 and a lower wall portion 782 which face each other with a certain space in the up-down direction, a left wall portion 783 connecting left ends of the upper and lower wall portions 781, 782 to each other, and a right wall portion 784 connecting right ends of the upper and lower wall portions 781, 782 to each other.

[0038] The upper wall portion 781 of the downstream end tubular portion 78 has: a first upper wall portion 781a which has a short plate shape and which extends backward from an opening upper edge 770 of the exhaust port 77: a vertical wall portion 781b extending downward from a back end of the first upper wall portion 781a; and a second upper wall portion 781c which has a flat plate shape and which extends backward from a lower end of the vertical wall portion 781b. Therefore, a recess portion 781d recessed backward from the opening upper edge 770 of the exhaust port 77 is formed over the entire upper wall portion 781 in the left-right direction forming an upper peripheral edge of the exhaust port 77 such that the downstream end exhaust passage part Pz expands upwardly at the opening upper edge 770 of the exhaust port 77. Further, inner wall surfaces (i.e., lower wall surfaces) of the first and second upper wall portions 781a, 781c are inclined upward toward the exhaust port 77 at the substantially same inclination angle. Although not illustrated, each of the first upper wall portion 781a and the vertical wall portion 781b is formed over the entire exhaust port 77 in the left-right direction. The second upper wall portion 781c is formed wider in the left-right direction than the exhaust port 77.

[0039] The lower wall portion 782 of the downstream end tubular portion 78 extends backward from the back surface of o the inclined portion 710, which is located below an opening lower edge 771 of the exhaust port 77. A back end of the lower wall portion 782 substantially faces a back end of the second upper wall portion 781c in the up-down direction. Further, an inner wall surface (i.e., upper wall surface) of the lower wall portion 782 is inclined upward toward the exhaust port 77 at the substantially same angle as the inner wall surfaces of the first and second upper wall portions 781a, 781c. Semicircular support portions 713 are respectively formed outwardly of corners between the lower wall portion 782 and the left and right wall portions 783, 784. The support portions 713 extend backward from the back surface of the inclined portion 710 of the main body front wall 71, which is located below the lower wall portion 782. Further, the second upper wall portion 781c and the lower wall portion 782 of the downstream end tubular portion 78 are formed such that their widths are greater than a width of the exhaust port 77 in the left-right direction and smaller than a width between the main body left wall 73 and the main body right wall 74. Therefore, an annular gap 714 of a certain size is formed between the downstream end tubular portion 78 and the main body upper wall 75, the main body left wall 73, the main body right wall 74, and the support portions 713. A tube front end portion of a later-described second tube 82 of the exhaust passage forming member 80 is inserted into the annular gap 714.

[0040] Further, the inclined portion 710 of the main body front wall 71 is provided with a flat plate shaped lower guide portion 79 formed below the opening lower edge 771 of the exhaust port 77 and above the lower wall portion 782 of the downstream end tubular portion 78. The lower guide portion 79 extends backward from the back surface of the inclined portion 710 of the main body front wall 71. An inner wall surface of the lower guide portion 79 is inclined upward toward the exhaust port 77 at the substantially same angle as the inner wall surface of the lower wall portion 782. Further, the lower guide portion 79 is formed such that its length in the front-back direction is shorter than a length of the lower wall portion 782 of the downstream end tubular potion 78 in the front-back direction. Further, the lower guide portion 79 is formed such that its width in the left-right direction is greater than the width of the exhaust port 77 in the left-right direction and smaller than the width of the lower wall portion 782 of the downstream end tubular portion 78 in the left-right direction. Thus, a gap of a certain size in the up-down and left-right directions is formed between the lower guide portion 79 and the downstream end tubular portion 78.

[0041] The exhaust passage forming member 80 has: a first tube 81 which has a cylindrical shape and which extends in the up-down direction; and the second tube 82 which has a substantially flat rectangular shape in the left-right direction and which is connected to an upper end of the first tube 81. The first tube 80 is disposed at a central portion of an internal space of the main body 70 in the front-back and left-right directions. The first tube 81 has, at the upper end thereof, a first upper opening 810 (hereinafter referred to as first opening 810) communicating with the second tube 82. Further, the first tube 81 has, at a lower end thereof, a first lower opening 811 (hereinafter referred to as inlet port 811) into which the combustion exhaust gas flows from the outer casing 100 via the exhaust connection portion 50. A lower end portion of the first tube 81 is fitted into the exhaust connection portion 50 described above. An annular packing is disposed between the lower end portion of the first tube 81 and the upper end portion of the exhaust connection portion 50, so that the first tube 81 and the exhaust connection portion 50 are connected in an airtight state.

[0042] The second tube 82 has an upper sidewall 820 and a lower sidewall 821 facing each other in the up-down direction, a left sidewall 822 connecting left ends of the upper and lower sidewalls 820, 821 to each other, a right sidewall 823 connecting right ends of the upper and lower sidewalls 820, 821 to each other, and a back sidewall 824 connecting back ends of the upper, lower, left and right sidewalls 820, 821, 822, 823 to each other. The second tube 82 has, at a front end thereof, an insertion port 830 flat in the left-right direction which is open frontward. A back end of the second tube 82 is closed. Further, the lower sidewall 821 of the second tube 82 has, at a central portion in the front-back and left-right directions, a second lower opening 831 (hereinafter referred to as second opening 831) communicating with the first opening 810 of the first tube 81. The downstream end tubular portion 78 of the main body 70 described above is inserted into the insertion port 830 of the second tube 82. Further, the tube front end portion of the second tube 82 is inserted into the annular gap 714 formed backwardly of the peripheral edge of the exhaust port 77 of the main body 70 described above.

[0043] Although not illustrated, the second tube 82 is formed such that when the downstream end tubular portion 78 of the main body 70 is inserted into the insertion port 830 of the second tube 82, the left and right sidewalls 822, 823 of the tube front end portion of the second tube 82 are respectively fitted onto the left and right wall portions 783, 784 of the downstream end tubular portion 78 substantially tightly, and the lower sidewall 821 is fitted onto the lower wall portion 782 substantially tightly. Further, the second tube 82 is formed such that when the downstream end tubular portion 78 of the main body 70 is inserted into the insertion port 830 of the second tube 82, the upper sidewall 820 of the tube front end portion of the second tube 82 is positioned above the upper wall portion 781 of the downstream end tubular portion 78 and near the main body upper wall 75 of the main body 70. Further, a flange portion 832 extending outward from a peripheral edge of the insertion port 830 is formed at the tube front end portion of the second tube 82. When the downstream end tubular portion 78 of the main body 70 is inserted into the insertion port 830 of the second tube 82, the flange portion 832 is in airtight contact with the back surface of the inclined portion 710 of the main body front wall 71 at the peripheral edge of the exhaust port 77 of the main body 70 via an annular packing. As a result, when the downstream end tubular portion 78 of the main body 70 is inserted into the insertion port 830 of the second tube 82 at a final position, a space part 9 (hereinafter referred to as upper space part 9) having an opening 90 (hereinafter referred to as upstream opening 90) opening backward is formed between the upper sidewall 820 of the tube front end portion of the second tube 82 and the upper wall portion 781 of the downstream end tubular portion 78. Further, this upper space part 9 is closed except for the upstream opening 90. Further, the main body 70 and the exhaust passage forming member 80 are formed such that a passage cross-sectional area of the upper space part 9 is greater than or equal to a passage cross-sectional area of the downstream end exhaust passage part Pz defined by the downstream end tubular portion 78 of the main body 70 (for example, the passage cross-sectional area of the upper space part 9/the passage cross-sectional area of the downstream end exhaust passage part Pz=1 to 2). Further, the lower sidewall 821 of the second tube 82 is formed such that when the lower sidewall 821 of the tube front end portion of the second tube 82 is disposed below the lower wall portion 782 of the downstream end tubular portion 78, an inner wall surface of the lower sidewall 821 which is located backward of the tube front end portion of the second tube 82 is substantially flush with the inner wall surface of the lower wall portion 782 of the downstream end tubular portion 78. Reinforcing ribs are formed on outer surfaces of the upper and lower sidewalls 820, 821 of the second tube 82.

[0044] Further, the lower sidewall 821 of the second tube 82 is inclined downward from a periphery of the lower sidewall 821 toward the second opening 831 such that the second opening 831 connected to the first tube 81 is located at the lowest level. With this configuration, even if the drain is generated in the second tube 82, the drain can be returned to the exhaust duct 4 from the first tube 81 as the drain flows toward the second opening 831.

[0045] When the exhaust port member 7 is attached to the combustion device 1000, the exhaust port member 7 in which the main body 70 and the exhaust passage forming member 80 are connected to each other is disposed above the outer casing 100. Then, the lower end portion of the first tube 81 of the exhaust passage forming member 80 is fitted into the exhaust connection portion 50 via the annular packing. When the fan 26 is operated in the combustion operation, the combustion exhaust gas flowing out from the exhaust connection portion 50 communicating with the exhaust duct 4 into the first tube 81 flows upward inside the first tube 81 and flows into the second tube 82. Then, the combustion exhaust gas flowing into the second tube 82 flows frontward inside the second tube 82 and is discharged to the outside through the exhaust port 77. Further, since the upper end of the first tube 81 is connected to the central portion of the lower sidewall 821 of the second tube 82 in the front-back and left-right directions, the second tube 82 has a bulging portion 827 bulging backward from a connection portion 826 of the first tube 81 and the second tube 82. It is thus that a portion of the combustion exhaust gas flowing out from the first tube 81 into the second tube 82 flows frontward while flowing into the bulging portion 827. Therefore, in the exhaust port member 7, the exhaust passage P is formed by connecting the first tube 81 defining a first exhaust passage P1 extending in the up-down direction and the second tube 82 defining a second exhaust passage P2 extending in the front-back direction. In this manner, the exhaust passage P has a T-shaped bent passage.

[0046] Further, as illustrated in FIG. 6, the upper space part 9 formed between the upper wall portion 781 of the downstream end tubular portion 78 and the upper sidewall 820 of the tube front portion of the second tube 82 communicates with the second exhaust passage P2 via the upstream opening 90. It is thus that a portion of the combustion exhaust gas flowing frontward in the second exhaust passage P2 flows into the upper space part 9 extending in the same direction as the downstream end exhaust passage part Pz. Further, as described above, the upper space part 9 is surrounded by the main body front wall 71, the upper wall portion 781 of the downstream end tubular portion 78, and the upper, left and right sidewalls 820, 822, 823 of the tube front end portion of the second tube 82, so that the upper space part 9 is closed except for the upstream opening 90 and the upper space part 9 does not communicate with the exhaust port 77 on a downstream side thereof. As a result, the upper wall portion 781 of the downstream end tubular portion 78 defining the downstream end exhaust passage part Pz is heated by the combustion exhaust gas flowing in the upper space part 9.

[0047] According to the present embodiment, since a portion of the combustion exhaust gas flows into the upper space part 9 located above and adjacent to the downstream end exhaust passage part Pz, it is possible to heat the upper wall portion 781 (upper partition wall) defining the downstream end exhaust passage part Pz from above and below. It is thus that even if an interior of the exhaust port member 7 is cooled by ambient air, a temperature of the inner wall surface of the upper wall portion 781 can be raised in a short time. Further, according to the present embodiment, since the upper space part 9 is closed except for the upstream opening 90, it is possible to prevent the drain generated in the upper space part 9 from flowing toward the exhaust port 77. With this configuration, it is possible to reduce the drain generated in the exhaust port member 7 during an initial stage of the combustion operation and to prevent the drain from scattering through the exhaust port 77.

[0048] Further, according to the present embodiment, since the upper wall portion 781 of the downstream end tubular portion 78 of the main body 70 is inclined upward toward the exhaust port 77, an area of the upper wall portion 781 that is in contact with the combustion exhaust gas can be increased and the temperature of the inner wall surface of the upper wall portion 781 can be raised in a short time. Further, according to the present embodiment, the drain generated when the combustion gas contacts the inner surface of the upper wall portion 781 can be returned to an upstream side of the exhaust passage P. With this configuration, it is possible to prevent the drain from scattering through the exhaust port 77.

[0049] Further, according to the present embodiment, since the passage cross-sectional area of the upper space part 9 is greater than or equal to the passage cross-sectional area of the downstream end exhaust passage part Pz adjacent thereto, the combustion exhaust gas smoothly flows into the upper space part 9. It is thus that the temperature of the inner wall surface of the upper wall portion 781 can be raised in a shorter time. With this configuration, it is possible to further prevent the drain from scattering through the exhaust port 77.

[0050] Further, according to the present embodiment, since the upper wall portion 781 extends from the peripheral edge of the exhaust port 77 toward the upstream side of the exhaust passage P and the upper wall portion 781 is provided with the recess portion 781d recessed backward from the opening upper edge 770 such that the downstream end exhaust passage part Pz expands upwardly at the opening upper edge 770 of the exhaust port 77, an area of the upper wall portion 781 that is in contact with the combustion exhaust gas can be increased. Therefore, the temperature of the inner surface of the upper wall portion 781 leading to the opening upper edge 770 of the exhaust port 77 which is cooled most by the ambient air can be raised in a shorter time. Further, the combustion exhaust gas flowing along the upper wall portion 781 in the downstream end exhaust passage part Pz is less likely to contact the opening upper edge 770 of the exhaust port 77 which is cooled most by the ambient air. With this Configuration, it is possible to prevent the drain from scattering through the exhaust port 77.

[0051] Further, according to the present embodiment, since the bent exhaust passage P is formed by connecting the first exhaust passage P1 extending in the up-down direction and the second exhaust passage P2 extending in the front-back direction, it is possible to prevent the combustion exhaust gas from flowing toward the exhaust port 77 from the inlet port 811 linearly. Further, according to the present embodiment, since the bent exhaust passage P is formed, it is possible to decrease a gas flow rate of the combustion exhaust gas flowing in the second exhaust passage P2. Further, according to the present embodiment, since a portion of the combustion exhaust gas flowing out from the first exhaust passage P1 into the second exhaust passage P2 flows into the bulging portion 827, it is possible to further decrease the gas flow rate of the combustion exhaust gas flowing in the second exhaust passage P2. It is thus that the combustion exhaust gas smoothly flows into the upper space part 9. Therefore, even if the interior of the exhaust port member 7 is cooled, the temperature of the inner wall surface of the upper wall portion 781 can be raised in a short time. Further, a time during which the combustion exhaust gas is in contact with the inner wall surfaces of the first and second tubes 81, 82 can be longer. It is thus that when the interior of the exhaust port member 7 is cooled, the drain can be generated in the exhaust passage P upstream of the exhaust port 77 and the generated drain can be returned to the exhaust duct 4. With this configuration, it is possible to prevent the drain from scattering through the exhaust port 77.

[0052] Note that the exhaust port member 7 can be applied not only to the downward combustion type combustion device but also to an upward combustion type combustion device. Further, the space part may be formed not only above but also below the downstream end exhaust passage part Pz.

Second Embodiment

[0053] As illustrated in FIG. 7, a combustion device 2000 to which an exhaust port member 7a of the present embodiment is applied has an outer casing 100a and a combustion device main body la housed in the outer casing 100a. The outer casing 100a includes a rectangular box-shaped casing body 101a having a front opening 103a and a front cover 102a closing the front opening 103a. An exhaust port member insertion hole 50a opens at an upper center portion of the front cover 102a in a left-right direction. An exhaust port member 7a is inserted into the exhaust port member insertion hole 50a. The combustion device main body 1a comprises: a burner 2a which ejects a mixture gas of fuel gas and air upward for combustion to generate combustion exhaust gas; a combustion box 3a which is disposed on an upper side of the burner 2a so as to surround a combustion space for the burner 2a; and an exhaust duct 4a in which the combustion exhaust gas discharged from the combustion box 3a flows. A heat exchanger is accommodated in the combustion box 3a. A fan 26a is connected to a lower portion of the burner 2a.

[0054] The exhaust port member 7a protrudes outward (frontward) from the outer casing 100a. The exhaust port member 7a is made of resin. The exhaust port member 7a has a flat tubular shape in the left-right direction. As illustrated in FIG. 8, the exhaust port member 7a has a front wall portion 71a flat in the left-right direction and an outer cylindrical periphery wall portion 72a flat in the left-right direction extending backward from a periphery of the front wall portion 71a. The exhaust port member 7a is open frontward and backward. An exhaust port 77a flat in the left-right direction opens at a central portion of the front wall 71a in an up-down direction. The exhaust port 77a opening frontward is located forward of the outer casing 100a. A back end of the exhaust port member 7a is connected to a front end of the exhaust duct 4a. When an outer peripheral flange protruding outward from a periphery of a back end opening 811a (hereinafter referred to as inlet port 811a) of the exhaust port member 7a is connected to an outer peripheral flange protruding outward from a periphery of a front end opening 40a of the exhaust duct 4a, the exhaust passage P is formed in the exhaust port member 7a and the combustion exhaust gas flows in the front-back direction in the exhaust passage P.

[0055] The exhaust port member 7a has an inner cylindrical periphery wall portion 78a flat in the left-right direction extending backward to a position facing a substantially half position of the outer cylindrical periphery wall portion 72a in the front-back direction from a peripheral edge of the exhaust port 77a. Therefore, the inner cylindrical periphery wall portion 78a defines a downstream end exhaust passage part Pz positioned at a downstream end of the exhaust passage P. An entire circumference of the inner cylindrical periphery wall portion 78a is surrounded by the outer cylindrical periphery wall portion 72a. Further, an annular space part 9a (hereinafter referred to as surrounding space part 9a) having an opening 90a (hereinafter referred to as upstream opening 90a) opening backward is formed between the inner cylindrical periphery wall portion 78a and the outer cylindrical periphery wall portion 72a. Further, the surrounding space part 9a is closed except for the upstream opening 90a. Further, the surrounding space part 9 does not communicate with the exhaust port 77a on a downstream side thereof. It is thus that a portion of the combustion exhaust gas flows into the surrounding space part 9a through the upstream opening 90a and the inner cylindrical periphery wall portion 78a is heated by the combustion exhaust gas flowing in the surrounding space part 9a. Further, the exhaust port member 7a is formed such that a passage cross-sectional area of the surrounding space part 9a is greater than or equal to a passage cross-sectional area of the downstream end exhaust passage part Pz defined by the inner cylindrical periphery wall portion 78a.

[0056] According to the present embodiment, since a portion of the combustion exhaust gas flowing out from the exhaust duct 4a into the exhaust port member 7a via the inlet port 811a flows into the surrounding space part 9a surrounding the entire circumference of the downstream end exhaust passage part Pz, it is possible to heat the inner cylindrical periphery wall portion 78a (a peripheral partition wall) defining the downstream end exhaust passage part Pz. It is thus that even if an interior of the exhaust port member 7a is cooled by ambient air, a temperature of an inner wall surface of the inner cylindrical periphery wall portion 78a can be raised in a short time. Further, according to the present embodiment, since the surrounding space part 9a is closed except for the upstream opening 90, it is possible to prevent the drain generated in the surrounding space part 9a from flowing toward the exhaust port 77a. Further, since the passage cross-sectional area of the surrounding space part 9a is greater than or equal to the passage cross-sectional area of the downstream end exhaust passage part Pz, the combustion exhaust gas smoothly flows into the surrounding space part 9a. With this configuration, it is possible to prevent the drain from scattering through the exhaust port 77a.

[0057] Note that the exhaust port member 7a of the present invention can be applied not only to the upward combustion type combustion device but also to the downward combustion type combustion device. Further, the exhaust port member 7a may be formed such that the exhaust passage P extends upward from the outer casing 100a.

[0058] As described in detail, the present invention is summarized as follows.

[0059] According to one aspect of the present invention, there is provided an exhaust port member applied to a combustion device installed outdoors, the exhaust port member comprising: [0060] an inlet port into which combustion exhaust gas generated in the combustion device flows; [0061] an exhaust port which is located outside an outer casing and through which the combustion exhaust gas is discharged to an outside; [0062] an exhaust passage in which the combustion exhaust gas flows from the inlet port toward the exhaust port; and [0063] a space part which is located adjacent to a downstream end exhaust passage part positioned at a downstream end of the exhaust passage via a partition wall defining the downstream end exhaust passage part, wherein [0064] the space part has an upstream opening on an upstream side thereof, [0065] the combustion exhaust gas flowing in the exhaust passage flows into the space part through the upstream opening, and [0066] the space part is closed except for the upstream opening.

[0067] According to the exhaust port member described above, since a portion of the combustion exhaust gas flows into the space part located adjacent to the downstream end exhaust passage part, it is possible to heat the partition wall defining the downstream end exhaust passage part. It is thus that even if an interior of the exhaust port member is cooled by ambient air, a temperature of the inner wall surface of the partition wall can be raised in a short time. With this configuration, it is possible to reduce drain generated in the exhaust port member during an initial stage of a combustion operation and to prevent the drain from scattering through the exhaust port.

[0068] Preferably, in the exhaust port member described above, [0069] the exhaust passage extends in a front-back direction and has the exhaust port at a front end thereof, [0070] the partition wall has an upper partition wall defining the downstream end exhaust passage part, [0071] the space part has an upper space part which is located above and adjacent to the downstream end exhaust passage part via the upper partition wall, [0072] the upper space part has the upstream opening on an upstream side thereof, [0073] the combustion exhaust gas flowing in the exhaust passage flows into the upper space part through the upstream opening, and [0074] the upper space part is closed except for the upstream opening.

[0075] According to the exhaust port member described above, since a portion of the combustion exhaust gas flows into the upper space part located above and adjacent to the downstream end exhaust passage part, it is possible to heat the upper partition wall defining the downstream end exhaust passage part. It is thus that even if the upper partition wall defining the downstream end exhaust passage part and the drain is easily generated by contact of the upper partition wall with the combustion exhaust gas, a temperature of an inner wall surface of the upper partition wall can be raised in a short time. With this configuration, it is possible to prevent the drain from scattering through the exhaust port.

[0076] Preferably, in the exhaust port member described above, [0077] the upper partition wall is inclined upward toward the exhaust port.

[0078] According to the exhaust port member described above, since the upper partition wall is inclined upward toward the exhaust port, an area of the upper partition wall can be increased and the temperature of the inner wall surface of the upper partition wall can be raised in a short time. Further, according to the exhaust port member described above, the drain generated when the combustion exhaust gas contacts the inner surface of the upper partition wall can be returned to an upstream side of the exhaust passage. With this configuration, it is possible to further prevent the drain from scattering through the exhaust port.

[0079] Preferably, in the exhaust port member described above, [0080] a passage cross-sectional area of the upper space part is greater than or equal to a passage cross-sectional area of the downstream end exhaust passage part.

[0081] According to the exhaust port member described above, since the passage cross-sectional area of the upper space part is greater than or equal to the passage cross-sectional area of the downstream end exhaust passage part adjacent thereto, the combustion exhaust gas smoothly flows into the upper space part. It is thus that the temperature of the inner wall surface of the upper partition wall can be raised in a shorter time. With this configuration, it is possible to further prevent the drain from scattering through the exhaust port.

[0082] Preferably, in the exhaust port member described above, [0083] the upper partition wall at a peripheral edge of the exhaust port has a recess portion recessed backward from an opening upper edge of the exhaust port, and [0084] the downstream end exhaust passage part expands upwardly at the opening upper edge of the exhaust port.

[0085] According to the exhaust port member described above, an area of the upper partition wall near the opening upper edge of the exhaust port can be increased. Therefore, the temperature of the inner surface of the upper partition wall leading to the opening upper edge of the exhaust port which is cooled most by the ambient air can be raised in a shorter time. Further, according to the exhaust port member described above, the combustion exhaust gas flowing along the upper partition wall is less likely to contact the opening upper edge of the exhaust port which is cooled most by the ambient air. With this configuration, it is possible to prevent the drain from scattering through the exhaust port.

[0086] Preferably, in the exhaust port member described above, [0087] the exhaust passage has a first exhaust passage extending in an up-down direction and a second exhaust passage extending in the front-back direction connected to each other, [0088] the first exhaust passage has the inlet port at a lower end thereof and a first opening at an upper end thereof, [0089] the second exhaust passage has a second opening communicating with the first opening of the first exhaust passage and the exhaust port at a front end thereof, and [0090] the second exhaust passage has a bulging portion bulging backward from a connection portion of the first exhaust passage and the second exhaust passage.

[0091] According to the exhaust port member described above, since the bent exhaust passage is formed by connecting the first exhaust passage extending in the up-down direction and the second exhaust passage extending in the front-back direction, it is possible to prevent the combustion exhaust gas from flowing toward the exhaust port from the inlet port linearly. Further, according to the exhaust port member described above, since the bent exhaust passage is formed, it is possible to decrease a gas flow rate of the combustion exhaust gas flowing in the second exhaust passage. Further, according to the exhaust port member described above, since a portion of the combustion exhaust gas flowing out from the first exhaust passage into the second exhaust passage flows into the bulging portion, it is possible to further decrease the gas flow rate of the combustion exhaust gas flowing in the second exhaust passage. It is thus that the combustion exhaust gas smoothly flows into the upper space part. Therefore, even if the interior of the exhaust port member is cooled, the temperature of the inner wall surface of the upper partition wall can be raised in a short time. With this configuration, it is possible to prevent the drain from scattering through the exhaust port.

[0092] Preferably, in the exhaust port member described above, [0093] the exhaust passage extends outward from the outer casing, [0094] the partition wall is a peripheral partition wall defining the downstream end exhaust passage part, [0095] the space part has a surrounding space part located adjacent to the downstream end exhaust passage part via the peripheral partition wall so as to surround an entire circumference of the downstream end exhaust passage part, [0096] the surrounding space part has the upstream opening on an upstream side thereof, [0097] the combustion exhaust gas flowing in the exhaust passage flows into the surrounding space part through the upstream opening, and [0098] the surrounding space part is closed except for the upstream opening.

[0099] According to the exhaust port member described above, since a portion of the combustion exhaust gas flows into the surrounding space part surrounding the entire circumference of the downstream end exhaust passage part, it is possible to heat the peripheral partition wall defining the downstream end exhaust passage part. It is thus that even if the interior of the exhaust port member is cooled by the ambient air, a temperature of an inner wall surface of the peripheral partition wall can be raised in a short time. With this configuration, it is possible to prevent the drain from scattering through the exhaust port.

[0100] Although the present invention has been described hereinabove with reference to exemplary embodiments, the present invention is not limited thereto. The configuration and details of the present invention are open to various modifications within the scope of the present invention that would be clear to those skilled in the art.

INDUSTRIAL APPLICABILITY

[0101] According to the present invention, there is provided an exhaust port member capable of preventing drain from scattering through an exhaust port.