Water heater

Abstract

To provide a water heater capable of preventing the leakage of combustion exhaust.SOLUTION: A path unit 7 is equipped with a covering portion 20, a fixed plate 31, a straightening plate 70, a fixed plate 32, and a connection plate 80. The covering portion 20 is equipped with a bulging portion 21 and a flange portion 22. On a back surface of the straightening plate 70, the fixed plate 31 is fixed, and on a front surface, the fixed plate 32 is fixed. The fixed plate 31 is fixed on an inner surface turning to a front side of the bulging portion 21. The connection plate 80 is fixed on a front surface of the flange portion 22 while abutting on the fixed plate 32 from a front side, and overlaps a boundary portion 101 from a rear side through a packing 90. In such a structure, the flange portion 22 overlaps an upper side of an inflow port 617, respective both right and left sides of the inflow port 617, the boundary portion 101, and an outflow port 531, and a lower side of the outflow port 531 from the rear side through the packing 90, and is fastened with the packing 90 by a screw 45.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a water heater.

Background Art

[0002] The water heater described in Patent Document 1 is a latent heat recovery type and includes a primary heat exchanger and a secondary heat exchanger. The primary heat exchanger is provided upstream of the exhaust path of the burner and performs heat exchange between the sensible heat of the combustion exhaust and the water flowing through the heat transfer pipe. The secondary heat exchanger is provided downstream of the exhaust path and above the primary heat exchanger, and performs heat exchange between the latent heat in the combustion exhaust and the water flowing through the heat transfer pipe.

[0003] The outlet of the primary heat exchanger and the inlet of the secondary heat exchanger are arranged vertically. The outlet and the inlet are connected to each other by a path member. The combustion exhaust that has passed through the primary heat exchanger flows from the outlet into the path member. The combustion exhaust that has passed through the path member flows into the secondary heat exchanger from the inlet. From the viewpoints of productivity and cost, such a path member preferably has a simple configuration.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the simpler the configuration of the path member is, the more difficult it is to make the path member closely adhere to the peripheral portions of each of the outlet and the inlet, particularly the boundary portion between the outlet and the inlet. As a result, there is a possibility that the combustion exhaust leaks to the outside.

[0006] An object of the present invention is to provide a water heater capable of preventing leakage of combustion exhaust.

Means for Solving the Problems

[0007] The water heater according to claim 1 is provided on the upstream side of an exhaust path through which the combustion exhaust gas of the burner flows, and includes a sensible heat recovery unit for exchanging the sensible heat of the combustion exhaust gas and the flowing water, and a latent heat recovery unit provided on the downstream side of the exhaust path and adjacent to the upper side of the sensible heat recovery unit for exchanging the latent heat of the combustion exhaust gas that has passed through the sensible heat recovery unit and the flowing water. An outlet portion that is provided at the rear portion of the sensible heat recovery unit, opens rearward, and has a rectangular shape that is longer in the left-right direction than in the vertical direction, and an inlet portion that is provided at the rear portion of the latent heat recovery unit, opens rearward, and has a rectangular shape that is longer in the left-right direction than in the vertical direction. A path member that is fixed via a packing and guides the combustion exhaust gas discharged from the outlet portion into the latent heat recovery unit through the inlet portion. The packing overlaps from the rear with the peripheral portions of the inlet portion and the outlet portion, respectively, and a boundary portion sandwiched vertically between the inlet portion and the outlet portion. The path member includes a main body portion having a bulging portion that bulges rearward and a flange portion that extends in the left-right direction from the front end portion of the bulging portion, a fixing member fixed to the inner surface facing forward of the bulging portion, and a plate-like member fixed to the front surface of the flange portion in a state of abutting against the fixing member from the front. The flange portion overlaps from the rear with the upper side of the inlet portion, the left and right sides of each of the inlet portion, the boundary portion, and the outlet portion, and the lower side of the outlet portion via the packing, and is fastened with screws together with the packing. The plate-like member overlaps from the rear with at least the central portion in the left-right direction at the boundary portion in a state where the flange portion is fastened. It protrudes in a flange shape outward, in the vertical direction and It is characterized in that.

[0008] The water heater of claim 2 comprises a sensible heat recovery section provided upstream of an exhaust path through which combustion exhaust from a burner flows, and which exchanges sensible heat of the combustion exhaust with water; a discharge section provided downstream of the exhaust path and adjacent to and above the sensible heat recovery section, for receiving the combustion exhaust that has passed through the sensible heat recovery section and discharging it to the outside; a rectangular outlet section provided at the rear of the sensible heat recovery section, opening toward the rear and being longer in the left-right direction than in the up-down direction; and a route member fixed via a packing to a rectangular inlet section provided at the rear of the discharge section, opening toward the rear and being longer in the left-right direction than in the up-down direction, and for directing the combustion exhaust discharged from the outlet section into the discharge section via the inlet section, the packing overlapping with the peripheral portions of the inlet section and the outlet section and the boundary section sandwiched vertically between the inlet section and the outlet section from the rear, and the route member has a bulging section bulging backward and a rectangular inlet section extending from a front end of the bulging section It protrudes in a flange shape outward, in the vertical direction and The device comprises a main body portion having a flange portion extending in the left-right direction, a fixing member fixed to the inner surface facing forward of the bulge portion, and a plate-shaped member fixed to the front surface of the flange portion while abutting the fixing member from the front, wherein the flange portion overlaps with the upper side of the inlet portion, the left and right sides of the inlet portion, the boundary portion, and the outlet portion, and the lower side of the outlet portion from the rear via the gasket, and is fastened together with the gasket with screws, and wherein the plate-shaped member overlaps with at least the left-right central portion of the boundary portion from the rear when the flange portion is fastened.

[0009] The plate-like member of the water heater according to claim 3 may be fixed at a position on the front surface of the flange portion so as to sandwich the bulging portion therebetween.

[0010] In the water heater according to claim 4, a recess may be formed in the front surface of the flange portion where the plate-like members overlap, the recess being recessed rearward in accordance with a thickness of the plate-like members.

[0011] In the water heater according to claim 5, the plate-like member may extend in the left-right direction and be bridged between the left and right side portions of the flange portion.

[0012] One or a plurality of protruding portions that protrude forward and extend parallel to the length direction of the boundary portion may be provided on the front surface of the plate-like member of the water heater according to claim 6.

Advantages of the Invention

[0013] According to the water heater of claim 1, by fixing a fixing member to the inner surface of the bulging portion and fixing the plate-like member to this fixing member, the tightening force by screwing is transmitted via the bulging portion, the fixing member, and the plate-like member to the packing located behind the boundary portion, and the packing located behind the boundary portion can be suitably crushed. Thereby, the sealing performance of the path member can be ensured. Therefore, although the water heater has a simple configuration, leakage of combustion exhaust from the path member can be prevented. Further, since the inlet portion and the outlet portion are rectangular with a longer left-right direction than the up-down direction, the central portion in the left-right direction where leakage is likely to occur among the boundary portions therebetween can be indirectly suppressed by the plate-like member via the packing, so that good sealing can be achieved. Note that the latent heat recovery portion recovers the latent heat in the combustion exhaust. However, if there is sensible heat that could not be completely recovered in the sensible heat recovery portion, it is recovered in the latent heat recovery portion.

[0014] According to the water heater of claim 2, by fixing a fixing member to the inner surface of the bulging portion and fixing the plate-like member to this fixing member, the tightening force by screwing is transmitted via the bulging portion, the fixing member, and the plate-like member to the packing located behind the boundary portion, and the packing located behind the boundary portion can be suitably crushed. Thereby, the sealing performance of the path member can be ensured. Therefore, although the water heater has a simple configuration, leakage of combustion exhaust from the path member can be prevented. Further, since the inlet portion and the outlet portion are rectangular with a longer left-right direction than the up-down direction, the central portion in the left-right direction where leakage is likely to occur among the boundary portions therebetween can be indirectly suppressed by the plate-like member via the packing, so that good sealing can be achieved.

[0015] According to the water heater of claim 3, the stress of screwing can be directly and uniformly applied to the boundary portion. Therefore, the water heater can improve the sealing performance of the path member.

[0016] According to the water heater of claim 4, by overlapping the plate-like member in the concave portion, the plate-like member and the front surface of the flange portion are flush. Therefore, the water heater can bring the packing into close contact with the front surface of the flange portion.

[0017] According to the water heater of claim 5, in the path member, two communication ports respectively communicating with the outlet portion of the primary heat exchanger and the inlet portion of the secondary heat exchanger can be easily formed.

[0018] According to the water heater of claim 6, the packing corresponding to the boundary portion can be more suitably crushed, so that the sealing performance of the path member can be improved.

[0019] Incidentally, the fixing member of the present invention is provided in the path member, partitions the internal space of the path member, and includes a rectifying member that rectifies the combustion exhaust flowing through the internal space, a first fixing member fixed to the back surface of the rectifying member, and a second fixing member fixed to the front surface of the rectifying member. By fixing the first fixing member to the inner surface of the bulging portion, the rectifying plate is supported at a position spaced forward from the inner surface of the bulging portion, and the connecting member may abut against the second fixing member from the front. According to this configuration, since the rectifying member can be arranged in the path member, the flow of the combustion exhaust passing through the path member can be rectified. Thereby, the pressure loss of the combustion exhaust in the path member can be prevented. Further, by making the rectifying member a part of the fixing member, the connecting member can be pressed from the rear by the first fixing member and the second fixing member.

[0020] Note that the first fixing member of the present invention is fixed in contact with the back surface of the rectifying member, and includes a first fixing portion having a U-shaped configuration when the rectifying member is viewed from the rear. The first fixing member is fixed in contact with a position on the front surface of the rectifying member that overlaps with the first fixing portion via the rectifying member, and includes a second fixing portion having a U-shaped configuration when the rectifying member is viewed from the front. The first closing portion on the side opposite to the opening side of the first fixing portion and the second closing portion on the side opposite to the opening side of the second fixing portion may not face each other via the rectifying member. According to this configuration, the first fixing member is fixed to the back surface of the rectifying member, and the second fixing member is fixed to the front surface. When fixing by spot welding, since three members cannot be fixed by spot welding at once, it is necessary to fix them two by two. In this case, the first fixing portion of the first fixing member is brought into contact with the back surface of the rectifying member for positioning. Since the first fixing portion is U-shaped, the overlapping portion between the first closing portion of the first fixing portion and the rectifying member is sandwiched from the front and rear by a pair of electrode sleeves of a spot welding machine to perform spot welding. Next, the second fixing portion of the second fixing member is brought into contact with the front surface of the rectifying member at a position overlapping with the first fixing portion via the rectifying member for positioning. Although the second fixing portion is also U-shaped, since the opening sides are opposite to each other, the second closing portion of the second fixing portion does not overlap with the first closing portion of the first fixing portion via the rectifying member. Thereby, the overlapping portion between the second closing portion of the second fixing portion and the rectifying member can be sandwiched from the front and rear by a pair of electrode sleeves of a spot welding machine to perform spot welding. Therefore, the rectifying member, the first fixing member, and the second fixing member can be integrally fixed by spot welding.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Embodiments for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be described. The device configurations and the like described below are not intended to be limited only thereto without specific descriptions, but are merely illustrative examples. The drawings are used to explain the technical features that can be adopted by the present invention. The following description uses left - right, front - back, and up - down indicated by arrows in the drawings.

[0023] Referring to FIGS. 1 to 6, the configuration of the water heater 1 will be described. As shown in FIGS. 1 and 2, the water heater 1 is a latent heat recovery type gas water heater. The water heater 1 includes, in order from the bottom, a fan 3, a combustion device 4, a primary heat exchanger 5, a secondary heat exchanger 6, and a path unit 7 (see FIG. 3) in a housing 2 (see FIG. 1).

[0024] The combustion device 4 includes a rectangular box-shaped inner case 4A. Inside the inner case 4A, a plurality of flat type lean-rich burners (not shown) are arranged in a stacked state in the left-right direction. The fan 3 is fixed to the lower part of the inner case 4A and supplies combustion air into the inner case 4A. A gas supply unit 8 is fixed to the front surface of the inner case 4A. The gas supply unit 8 distributes and supplies gas to the plurality of lean-rich burners in the inner case 4A. Inside the inner case 4A, combustion exhaust gas is generated when the plurality of lean-rich burners burn the air-fuel mixture.

[0025] As shown in FIGS. 2 and 3, the primary heat exchanger 5 includes a peripheral wall 51, heat transfer tubes 52 (see FIG. 2), and an exhaust hood 53. The peripheral wall 51 is in a substantially rectangular tube shape extending in the vertical direction and is connected to the upper opening of the inner case 4A. The peripheral wall 51 includes a right wall 511, a left wall 512, a front wall 513, and a rear wall 514. The peripheral wall 51 allows the combustion exhaust gas generated by the combustion device 4 to pass from below to above. An inlet 55 is provided in the right wall 511. An outlet 56 is provided in the left wall 512. The heat transfer tubes 52 are bent and arranged to reciprocate a plurality of times in the left-right direction inside the peripheral wall 51 (see FIGS. 4 and 5). The heat transfer tubes 52 are water pipes and recover sensible heat from the combustion exhaust gas passing through the inside of the peripheral wall 51 from below to above. One end portion on the upstream side of the heat transfer tubes 52 is connected to the inlet 55, and one end portion on the downstream side is connected to the outlet 56.

[0026] The exhaust hood 53 is provided so as to cover the upper opening of the peripheral wall 51 and bulges upward. The rear wall 530 (see FIG. 6) of the exhaust hood 53 is in a rectangular shape that is long in the left-right direction when viewed from the rear. An outlet 531 is provided in the rear wall 530. The outlet 531 is in a substantially rectangular shape that is long in the left-right direction when viewed from the rear and opens rearward. The outlet 531 allows the combustion exhaust gas in the exhaust hood 53 to flow out into the covering portion 20 described later. In the rear wall 530, five fixing holes 58 are provided on the right side, left side, and lower side of the outlet 531.

[0027] As shown in FIGS. 2 and 3, the secondary heat exchanger 6 includes a housing 61, heat transfer tubes 62, and an exhaust portion 63. The housing 61 includes a right wall 611, a left wall 612, a front wall 613, a rear wall 614 (see FIGS. 3 and 6), an upper wall 615 (see FIGS. 2, 4, and 5), and a bottom wall 616 (see FIGS. 4 and 5). An inlet 65 and an outlet 66 are provided in the right wall 611. An opening 618 (see FIG. 4) is provided in the front wall 613. The width of the housing 61 in the left-right direction is substantially the same as the width of the peripheral wall 51 of the primary heat exchanger 5 in the left-right direction. The length of the housing 61 in the front-rear direction is longer than the length of the peripheral wall 51 of the primary heat exchanger 5 in the front-rear direction. In plan view, the position of the rear wall 614 is substantially the same as the position of the rear wall 514 of the peripheral wall 51 of the primary heat exchanger 5. Therefore, the position of the front wall 613 is a position protruding forward from the position of the front wall 513 of the peripheral wall 51 of the primary heat exchanger 5. The bottom wall 616 is disposed above the exhaust hood 53 of the primary heat exchanger 5.

[0028] As shown in FIG. 6, an inlet 617 is provided in the rear wall 614. The inlet 617 is substantially rectangular in shape and long in the left-right direction in rear view, and opens rearward. The width of the inlet 617 in the left-right direction is substantially the same as the width of the outlet 531 in the left-right direction. The inlet 617 allows the combustion exhaust flowing in the covering portion 20 described later to flow into the housing 61. Five fixing holes 68 are provided on the right side, left side, and upper side of the inlet 617 in the rear wall 614.

[0029] The heat transfer tubes 62 are bent and arranged in the housing 61 so as to reciprocate a plurality of times in the left-right direction (see FIGS. 4 and 5). The heat transfer tubes 62 are water pipes, and recover the latent heat from the combustion exhaust whose sensible heat has been recovered by the primary heat exchanger 5. Although the secondary heat exchanger 6 recovers the latent heat in the combustion exhaust, if there is sensible heat that could not be completely recovered by the primary heat exchanger 5, it is recovered in the heat transfer tubes 62 of the secondary heat exchanger 6. One end portion on the upstream side of the heat transfer tubes 62 is connected to the inlet 65, and one end portion on the downstream side is connected to the outlet 66.

[0030] The exhaust part 63 is provided on the front wall 613 (see FIGS. 1 and 2). The exhaust part 63 includes a flange part 631 and an exhaust pipe 632. The flange part 631 is formed in a substantially rectangular frame shape that is long in the left-right direction in a front view and is fixed to the front surface of the front wall 613. The exhaust pipe 632 is provided so as to protrude forward from the inner edge part of the opening of the flange part 631 and is substantially oval in shape that is long in the left-right direction in a front view. The exhaust pipe 632 is arranged on the front side of the opening 618 provided in the front wall 613 (see FIG. 4). The exhaust pipe 632 penetrates through the front cover (not shown) of the housing 2 and protrudes forward, discharging the combustion exhaust that has passed through the housing 61 to the outside of the housing 2.

[0031] As shown in FIGS. 4 to 6, the path unit 7 is provided so as to cover the rear wall 530 of the exhaust hood 53 of the primary heat exchanger 5 and the rear wall 614 of the secondary heat exchanger 6 from the rear. The path unit 7 includes a covering part 20. The covering part 20 is formed in a substantially horizontally long rectangular shape in a rear view, and a substantially rectangular central part (the rear wall 211 described later) excluding its outer edge part bulges backward. The covering part 20 forms a space inside for allowing the combustion exhaust to pass from the outlet 531 toward the inlet 617. As shown in FIGS. 4 and 5, a rectifying plate 70 is supported inside the covering part 20. The rectifying plate 70 divides the space inside the covering part 20 into two and rectifies the combustion exhaust flowing inside the covering part 20 into two flows. The specific configuration of the path unit 7 will be described later.

[0032] On the lower surface of the housing 2, a gas inlet 11, a water inlet 12, and a hot water outlet 13 are provided. An external gas pipe (not shown) is connected to the gas inlet 11. A water pipe (not shown) is connected to the water inlet 12. A pipe (not shown) to a hot water tap is connected to the hot water outlet 13. The gas inlet 11 is connected to the gas supply unit 8 in the housing 2 via a gas pipe 14 provided with an original valve, a proportional valve, etc. The water inlet 12 is connected to the water supply section 15. The water supply section 15 is connected to the inlet 65 of the secondary heat exchanger 6 via water supply pipes 16A and 16B. The outlet 66 of the secondary heat exchanger 6 is connected to the inlet 55 of the primary heat exchanger 5 via a relay pipe 17. The outlet 56 of the primary heat exchanger 5 is connected to the hot water outlet 13 via a hot water pipe 18. A bypass pipe 19 is connected between the water supply section 15 and the hot water pipe 18. The bypass pipe 19 merges a part of the water supplied from the water supply section 15 into the hot water flowing through the hot water pipe 18 without passing through the primary heat exchanger 5 and the secondary heat exchanger 6.

[0033] Referring to FIGS. 7 and 8, the specific configuration of the path unit 7 will be described. The path unit 7 includes, in order from the rear, a covering portion 20, a fixing plate 31, a rectifying plate 70, a fixing plate 32, a connecting plate 80, and a packing 90.

[0034] The shape of the covering portion 20 will be described. The covering portion 20 forms a space inside which the combustion exhaust flows. The covering portion 20 is formed of a metal plate having a substantially rectangular shape in a rear view, and includes a bulging portion 21 and a flange portion 22. The bulging portion 21 is formed in a substantially box shape with an open front by a rear wall 211 having a substantially rectangular shape in a front view excluding the outer peripheral edge portion bulging rearward. The flange portion 22 protrudes outward in a flange shape from the open end on the front side of the bulging portion 21, and is formed in a substantially rectangular frame shape that is horizontally long in a front view. A pair of left and right protrusions 23 arranged at intervals left and right are provided at the center of the front surface of the rear wall 211. The protrusions 23 protrude forward.

[0035] At the vertical center of each of the right and left sides of the flange portion 22, a recess 26 is provided. The recess 26 extends in the left - right direction so as to be orthogonal to the length direction of each of the right and left sides, and is formed to be recessed rearward. The depth of the recess 26 is substantially the same as the plate thickness of a connection plate 80 described later. A protrusion 27 is provided in the recess 26. The protrusion 27 protrudes forward. Three fixing holes 24 are provided at equal intervals in the left - right direction in each of the upper and lower portions of the flange portion 22. Two fixing holes 24 are provided in each of the right and left sides of the flange portion 22 at positions sandwiching the recess 26 at the vertical center. The size of the cover portion 20 when viewed from the back is substantially the same as the size obtained by vertically connecting the rear wall 530 of the exhaust hood 53 of the primary heat exchanger 5 and the rear wall 614 of the secondary heat exchanger 6.

[0036] The shape of the rectifying plate 70 will be described. The rectifying plate 70 is a metal plate and includes a main body portion 71, a lower bent portion 72, and an upper bent portion 73. The main body portion 71 is formed in a substantially rectangular shape that is long in the left - right direction when viewed from the front. A protrusion 711 (see FIG. 8) is provided at the lower part of the right end of the back surface of the main body portion 71. The protrusion 711 protrudes rearward. A protrusion 712 (see FIG. 7) is provided at the upper part of the right end of the front surface of the main body portion 71. The protrusion 712 protrudes forward. A protrusion 713 (see FIG. 8) is provided at the upper part of the left end of the back surface of the main body portion 71. The protrusion 713 protrudes rearward. A protrusion 714 (see FIG. 7) is provided at the lower part of the left end of the front surface of the main body portion 71.

[0037] A fixing piece 74 is provided at the right end of the main body 71, and a fixing piece 75 is provided at the left end. The fixing piece 74 is formed in a substantially L shape in plan view, extends forward from the center of the right end of the main body 71, and bends and extends to the right at the tip side. On the upper part of the front surface of the tip portion 741 that extends to the right of the fixing piece 74, a protrusion 78 that protrudes forward is provided. The fixing piece 75 has a shape that is symmetrical to the left and right with the fixing piece 74 and is formed in a substantially inverted L shape in plan view. The fixing piece 75 extends forward from the center of the left end of the main body 71, and bends and extends to the left at the tip side. On the lower part of the front surface of the tip portion 751 that extends to the left of the fixing piece 75, a protrusion 79 that protrudes forward is provided. The lower bending portion 72 bends in a substantially arc shape in side view from the lower end of the main body 71 forward. The upper bending portion 73 bends in a substantially arc shape in side view from the upper end of the main body 71 forward.

[0038] The shapes of the fixing plates 31 and 32 will be described. Since the fixing plates 31 and 32 are common parts to each other, the shape of the fixing plate 31 will be described. The fixing plate 31 includes a central portion 35, a first fixing portion 36, and a second fixing portion 37. The length of the fixing plate 31 in the left-right direction is substantially the same as the length of the main body 71 of the rectifying plate 70 in the left-right direction. The central portion 35 is formed in a substantially U shape that opens forward in plan view and in a substantially rectangular shape that is long in the left-right direction in front view. A pair of left and right hole portions 351 are provided in the central portion 35. The pair of hole portions 351 correspond to a pair of protrusions 23 provided on the front surface of the rear wall 211 of the covering portion 20.

[0039] The first fixing portion 36 extends to the right from the front end portion on the right side of the central portion 35 and is formed in a substantially inverted U shape that opens downward in rear view. A pair of upper and lower fixing holes 361 are provided on the right end side of the first fixing portion 36. The second fixing portion 37 extends to the left from the front end portion on the left side of the central portion 35 and is formed in a substantially U shape that opens upward in rear view. A pair of upper and lower fixing holes 371 are provided on the left end side of the second fixing portion 37. The fixing holes 361 and 371 penetrate in the front-rear direction.

[0040] As will be described later, the fixed plate 31 is fixed to the back side of the rectifying plate 70, and the fixed plate 32 is fixed to the front side of the rectifying plate 70. The fixed plate 32 is opposite to the fixed plate 31 in the front-back direction, and is arranged with the inner side where the central portion 35 opens facing backward. The first fixing portion 36 located on the right side is substantially U-shaped and opens upward in a front view. The second fixing portion 37 located on the left side is substantially reverse U-shaped and opens downward in a front view. As described above, since the fixed plates 31 and 32 are common parts to each other, storage management is easy.

[0041] The shape of the connection plate 80 will be described. The connection plate 80 is a metal plate and is formed in a substantially rectangular shape that is elongated in the left-right direction in a front view. The connection plate 80 includes a main body portion 81, a right fixing portion 82, and a left fixing portion 83. The main body portion 81 is the central portion of the connection plate 80 in the left-right direction and is formed in a substantially rectangular shape that is elongated in the left-right direction in a front view. On the front surface of the main body portion 81, a pair of upper and lower protruding portions 84 extend in the left-right direction and are parallel to each other. The protruding portion 84 protrudes forward from the front surface of the main body portion 81 in a rib shape. The protruding portion 84 improves the rigidity of the main body portion 81. A fixing hole 87 penetrating in the front-rear direction is provided at the upper part of the right end portion of the main body portion 81. A fixing hole 88 penetrating in the front-rear direction is provided at the lower part of the left end portion of the main body portion 81.

[0042] The right fixing portion 82 is provided at the right end portion of the main body portion 81. The right fixing portion 82 is formed in a substantially rectangular shape that is long in the up-down direction in a front view. The right fixing portion 82 has substantially the same size as the concave portion 26 provided on the right side portion of the flange portion 22 of the covering portion 20. A fixing hole 85 is provided at the center of the right fixing portion 82. A rib 821 protruding forward is provided at the right end portion of the right fixing portion 82. The left fixing portion 83 is provided at the left end portion of the main body portion 81. The left fixing portion 83 is formed in a substantially rectangular shape that is long in the up-down direction in a front view. The left fixing portion 83 also has substantially the same size as the concave portion 26 provided on the left end portion of the flange portion 22 of the covering portion 20. A fixing hole 86 is provided at the center of the left fixing portion 83. A rib 831 protruding forward is provided at the left end portion of the left fixing portion 83.

[0043] Describe the shape of the packing 90. The packing 90 is formed of, for example, synthetic resin, and its thickness is about 3 mm. The packing 90 includes a frame portion 91 and an installation portion 92. The frame portion 91 is formed in a substantially rectangular frame shape that is long in the left-right direction in a front view, and is substantially the same size as the covering portion 20. The width of each of the upper portion, lower portion, right portion, and left portion of the frame portion 91 is substantially the same as the width of the flange portion 22.

[0044] The installation portion 92 is installed between the central portions of the right inner edge portion and the left inner edge portion of the inner peripheral edge of the opening inside the frame portion 91, and is formed in a substantially rectangular shape that is long in the left-right direction in a front view. An upper opening 93 is formed above the installation portion 92, and a lower opening 94 is formed below the installation portion 92. The upper opening 93 and the lower opening 94 are formed in a substantially rectangular shape that is long in the left-right direction in a front view. Three fixing holes 95 are provided in each of the upper portion and the lower portion of the frame portion 91. The three fixing holes 95 are arranged on the right side, the center, and the left side of each of the upper portion and the lower portion. Two fixing holes 95 are provided in each of the right portion and the left portion of the frame portion 91. The two fixing holes 95 are arranged at positions corresponding to the upper opening 93 and the lower opening 94, respectively, in each of the upper portion and the lower portion.

[0045] Describe an example of the assembling method of the path unit 7. For the sake of convenience of explanation, regarding the orientation of each component when assembling the path unit 7, it will be described following the orientation in the state of being housed in the water heater 1. First, as shown in FIGS. 7 and 8, the assembler arranges the fixing plate 31 on the back side of the main body portion 71 of the rectifying plate 70. Each of the first fixing portion 36 and the second fixing portion 37 is brought into contact with the back of the main body portion 71 from the rear. At this time, the lower fixing hole 361 provided at the right end side of the back of the main body portion 71 is engaged with the protrusion 711 provided at the lower part of the right end side of the first fixing portion 36 of the fixing plate 31 for positioning. Further, the upper fixing hole 371 provided at the left end side of the second fixing portion 37 of the fixing plate 31 is engaged with the protrusion 713 provided at the upper part of the left end side of the main body portion 71 for positioning.

[0046] In this state, the overlapping portion W1 (see FIG. 9) of the first fixing portion 36 and the main body portion 71 is sandwiched from the front and rear directions by a pair of electrode sleeves (not shown) of a spot welding machine, and spot welding is performed. The overlapping portion W1 is a portion where the upper portion on the side opposite to the opening side of the substantially inverted U-shaped first fixing portion 36 overlaps with the main body portion 71. Further, the overlapping portion W2 of the second fixing portion 37 and the main body portion 71 is sandwiched from the front and rear directions by a pair of electrode sleeves (not shown) of a spot welding machine, and spot welding is performed. The overlapping portion W2 is a portion where the lower portion on the side opposite to the opening side of the substantially U-shaped second fixing portion 37 overlaps with the main body portion 71. Thereby, the fixing plate 31 is fixed to the back surface of the main body portion 71 (see FIG. 9).

[0047] Next, the fixing plate 32 is disposed on the front side of the main body portion 71 of the rectifying plate 70. As described above, the orientation of the fixing plate 32 is opposite to that of the fixing plate 31 in terms of up and down and front and back. Each of the first fixing portion 36 and the second fixing portion 37 is brought into contact with the front surface of the main body portion 71. At this time, the upper fixing hole 361 provided on the right end side of the first fixing portion 36 of the fixing plate 31 is engaged with and positioned with respect to the protrusion 712 provided on the upper right end side of the front surface of the main body portion 71. Further, the lower fixing hole 371 provided on the left end side of the first fixing portion 36 of the fixing plate 31 is engaged with and positioned with respect to the protrusion 714 provided on the lower left end side of the front surface of the main body portion 71.

[0048] In this state, the overlapping portion W3 (see FIG. 10) of the first fixing portion 36 of the fixing plate 32 and the main body portion 71 is sandwiched from the front and rear directions by a pair of electrode sleeves (not shown) of a spot welding machine, and spot welding is performed. The overlapping portion W3 is a portion where the lower portion on the side opposite to the opening side of the substantially U-shaped first fixing portion 36 overlaps with the main body portion 71. Further, the overlapping portion W4 of the second fixing portion 37 of the fixing plate 32 and the main body portion 71 is sandwiched from the front and rear directions by a pair of electrode sleeves (not shown) of a spot welding machine, and spot welding is performed. The overlapping portion W4 is a portion where the upper portion on the side opposite to the opening side of the substantially inverted U-shaped first fixing portion 36 overlaps with the main body portion 71. Thereby, the fixing plate 32 is fixed to the front surface of the main body portion 71 (see FIG. 10).

[0049] Thus, spot welding is a method of welding by applying current while sandwiching two metal plates and applying pressure. Therefore, after fixing the fixing plate 31 to the back surface of the main body 71, it is necessary to fix the fixing plate 31 to the front surface of the main body 71, or vice versa. And the portion sandwiched by the pair of electrode slopes of the spot welder must be two metals. Therefore, in the present embodiment, the first fixing portions 36 and the second fixing portions 37 of the fixing plates 31 and 32 are each formed in a substantially U shape, and when the fixing plates 31 and 32 are positioned on the back surface and the front surface of the main body 71 of the rectifying plate 70, the first fixing portions 36 and the second fixing portions 37 are arranged so that they are vertically reversed with respect to each other via the main body 71. Thereby, when the rectifying plate 70 is viewed through from the front side to the rear, the overlapping portions W3 and W4 of the fixing plate 32 and the main body 71 do not overlap the overlapping portions W1 and W2 of the fixing plate 31 and the main body 71. Therefore, in the overlapping portions W1 to W4, two metal plates are formed, so that each portion can be spot welded, and as a result, the fixing plates 31 and 32 can be fixed to the rectifying plate 70 by spot welding.

[0050] Next, as shown in FIG. 10, the connection plate 80 is arranged in the left-right direction on the front side of the rectifying plate 70 to which the fixing plate 32 is fixed to the front surface. The right end side of the main body 81 is arranged on the front surface of the tip portion 741 of the fixing piece 74 of the rectifying plate 70, and the fixing hole 87 provided on the right end side of the main body 81 is positioned on the protrusion 78 of the fixing piece 74 of the rectifying plate 70. At the same time, the left end side of the main body 81 is arranged on the front surface of the tip portion 751 of the fixing piece 75 of the rectifying plate 70, and the fixing hole 88 provided on the left end side of the main body 81 is positioned on the protrusion 79 of the fixing piece 75 of the rectifying plate 70. In this state, spot welding is performed on the front surface of the tip portion 741 of the fixing piece 74 on the right end side of the main body 81, and spot welding is performed on the front surface of the tip portion 751 of the fixing piece 75 on the left end side of the main body 81. Thereby, the connection plate 80 is fixed to the fixing pieces 74 and 75 of the rectifying plate 70, and is in a state of being laid in the left-right direction between the fixing pieces 74 and 75 (see FIG. 11). The back surface of the main body 81 of the connection plate 80 abuts on the front surface of the central portion 35 of the fixing plate 32. Therefore, the central portion of the connection plate 80 is stably supported by the fixing plate 32, the rectifying plate 70, and the fixing plate 31.

[0051] Next, as shown in FIG. 11, the rectifying plate 70 to which the fixing plates 31 and 32 and the connection plate 80 are fixed is disposed on the front side of the covering portion 20. The back surface of the central portion 35 of the fixing plate 31 fixed to the back surface of the rectifying plate 70 is disposed on the front surface of the rear wall 211 of the covering portion 20. With respect to the pair of left and right protrusions 23 provided on the front surface of the rear wall 211, the pair of left and right hole portions 351 provided in the central portion 35 are positioned, and spot welding is performed from the front. Thereby, the rectifying plate 70 is fixed to the front surface of the rear wall 211 of the covering portion 20 via the fixing plate 31.

[0052] Furthermore, the right fixing portion 82 of the connection plate 80 is disposed on the front surface of the recess 26 provided in the right side portion of the flange portion 22 of the covering portion 20. At this time, the fixing hole 85 provided in the right fixing portion 82 of the connection plate 80 is positioned with respect to the protrusion 27 provided on the front surface of the recess 26. Also, the left fixing portion 83 of the connection plate 80 is disposed on the front surface of the recess 26 provided in the left side portion of the flange portion 22 of the covering portion 20. At this time, the fixing hole 86 provided in the left fixing portion 83 of the connection plate 80 is positioned with respect to the protrusion 27 provided on the front surface of the recess 26. In this state, spot welding is performed on the right fixing portion 82 and the left fixing portion 83 of the connection plate 80 with respect to the corresponding respective recesses 26. Thereby, the right end portion and the left end portion of the connection plate 80 are fixed to the right side portion and the left side portion of the flange portion 22 of the covering portion 20 (see FIG. 12).

[0053] A communication port 151 is formed below the connection plate 80, and a communication port 152 is formed above the connection plate 80. The communication ports 151 and 152 are substantially rectangular in shape with a horizontally long front view. The communication port 151 corresponds to the outflow port 531 of the primary heat exchanger 5. The communication port 151 is an opening for taking the combustion exhaust flowing out from the outflow port 531 into the covering portion 20. The communication port 152 corresponds to the inflow port 617 of the secondary heat exchanger 6. The communication port 152 is an opening for allowing the combustion exhaust that has passed through the covering portion 20 to flow into the inflow port 617.

[0054] Note that the depth of the recess 26 is substantially the same as the respective plate thicknesses of the right fixing portion 82 and the left fixing portion 83 of the connection plate 80. Therefore, as shown in FIG. 13, the step between the front surfaces of the right fixing portion 82 and the left fixing portion 83 and the front surface of the flange portion 22 can be reduced. Inside each recess 26, a sealing material 200 is applied to the gap Q formed on the outer periphery of each of the right fixing portion 82 and the left fixing portion 83. As a result, the inside of each recess 26 is horizontally filled by the right fixing portion 82 or the left fixing portion 83 and the sealing material 200, so that the step with the front surface of the flange portion 22 can be made smaller.

[0055] Next, as shown in FIG. 12, the packing 90 is adhesively attached to the flange portion 22 of the covering portion 20 to which the rectifying plate 70 and the connection plate 80 are fixed from the front. As shown in FIG. 14, the frame-shaped portion 91 of the packing 90 is attached to the front surface of the flange portion 22. The bridging portion 92 of the packing 90 is attached to the front surface of the connection plate 80. At this time, the right end portion of the frame-shaped portion 91 abuts against the left surface of the rib 821 of the right fixing portion 82 of the connection plate 80, and the left end portion of the frame-shaped portion 91 abuts against the right surface of the rib 831 of the left fixing portion 83 of the connection plate 80. The upper end portion of the bridging portion 92 abuts against the lower surface of the rib 811 at the upper end portion of the main body portion 81 of the connection plate 80, and the lower end portion of the bridging portion 92 abuts against the lower surface of the rib 812 at the lower end portion of the main body portion 81 of the connection plate 80. Thereby, the packing 90 can be prevented from being displaced with respect to the flange portion 22 of the covering portion 20 and the connection plate 80. In this way, the path unit 7 is completed.

[0056] Then, as shown in FIG. 6, the completed path unit 7 is pressed against the rear wall 530 of the exhaust hood 53 of the primary heat exchanger 5 and the rear wall 614 of the secondary heat exchanger 6 from the rear. The front surface of the flange portion 22 abuts against the right side, left side, lower side of the outlet 531 on the rear wall 530 of the primary heat exchanger 5 and the right side, left side, upper side of the inlet 617 on the rear wall 614 of the secondary heat exchanger 6 via the frame-shaped portion 91 of the packing 90, respectively. The front surface of the connection plate 80 abuts against the boundary portion 101 between the outlet 531 and the inlet 617 via the bridging portion 92 of the packing 90.

[0057] The ten fixing holes 24 provided in the flange portion 22 are respectively arranged in five fixing holes 58 provided in the rear wall 530 of the primary heat exchanger 5 and five fixing holes 68 provided in the rear wall 614 of the secondary heat exchanger 6 via the ten fixing holes 95 provided in the packing 90. Ten screws 45 are inserted into the ten fixing holes 24 provided in the flange portion 22 from the rear and fastened to the five fixing holes 58 and the five fixing holes 68 respectively via the ten fixing holes 95 of the packing 90. Thereby, the path unit 7 is stably and firmly fixed so as to cover the rear walls 530 and 614 of the primary heat exchanger 5 and the secondary heat exchanger 6 from the rear (see FIG. 3).

[0058] As shown in FIGS. 4 and 5, within the covering portion 20, the flow rectifying plate 70 is supported at a position spaced forward from the front surface of the rear wall 211 of the bulging portion 21. The main body portion 71 of the flow rectifying plate 70 divides the space within the covering portion 20 into front and rear parts. Thereby, the combustion exhaust gas is actively introduced into the front side portion of the internal space of the covering portion 20. Therefore, it is possible to prevent the generation of a vortex of the combustion exhaust gas in the internal space of the covering portion 20, and thus it is possible to prevent the occurrence of a pressure loss.

[0059] In this way, in the water heater 1, the fixing plate 31, the flow rectifying plate 70, and the fixing plate 32 are fixed to the front surface of the rear wall 211 of the bulging portion 21 of the covering portion 20, and the connecting plate 80 is fixed to the fixing plate 32. Thereby, the water heater 1 can effectively act the tightening force of the screw 45 on the packing 90 located behind the boundary portion 101 via the bulging portion 21, the fixing plate 31, the flow rectifying plate 70, and the fixing plate 32. Thereby, the water heater 1 can preferably crush the packing 90, so that the path unit 7 can be brought into close contact with the peripheral portions of the outlet 531 and the inlet 617 respectively, and the boundary portion 101 between the outlet 531 and the inlet 617. Therefore, although the water heater 1 has a simple structure, it can prevent the leakage of the combustion exhaust gas.

[0060] In addition, since the outlet 531 and the inlet 617 are rectangular and longer in the left - right direction than in the up - down direction, among the boundary parts 101 therebetween, the central part in the left - right direction where leakage is likely to occur can be indirectly suppressed by the connection plate 80 via the packing 90, so that good sealing can be achieved.

[0061] The connection plate 80 is fixed at a position sandwiching the bulging part 21 on the front surface of the flange part 22 of the covering part 20 when the covering part 20 is viewed from the front. Thereby, the water heater 1 can act on the boundary part 101 more directly and uniformly with the tightening stress of the screw 45. Thereby, the water heater 1 can further improve the sealing performance of the covering part 20.

[0062] The depth of the recesses 26 provided on both the left and right sides of the flange part 22 is substantially the same as the plate thickness of each of the right fixing part 82 and the left fixing part 83 of the connection plate 80. Thus, the front surfaces of the right fixing part 82 and the left fixing part 83 are flush with the front surface of the flange part 22. Thereby, the packing 90 can be made to closely adhere to the front surface of the flange part 22, so that the sealing performance of the covering part 20 can be further improved.

[0063] The connection plate 80 extends in the left - right direction and is installed between both left and right side parts of the flange part 22 of the covering part 20. Thereby, in the covering part 20, two communication ports 151 and 152 that communicate with the outlet 531 of the primary heat exchanger 5 and the inlet 617 of the secondary heat exchanger 6 respectively can be easily formed.

[0064] On the front surface of the connection plate 80, two protruding parts 84 are provided. The protruding parts 84 protrude forward and extend parallel to the length direction of the boundary part 101. Thereby, the water heater 1 can more suitably crush the packing 90 corresponding to the boundary part 101, so that the sealing performance of the covering part 20 can be further improved.

[0065] In the above description, the outlet 531 of the exhaust hood 53 is an example of the "outlet part" of the present invention, and the inlet 617 is an example of the "inlet part" of the present invention. The path unit 7 is an example of the "path member" of the present invention. The covering part 20 is an example of the "main body part" of the present invention. The fixing plates 31 and 32, and the flow rectifying plate 70 are examples of the "fixing members" of the present invention. The connection plate 80 is an example of the "plate-like member" of the present invention. Further, the "sensible heat recovery part" of the present invention is a part that recovers the sensible heat in the combustion exhaust gas, and in this embodiment in the specification, it is a concept including the primary heat exchanger 5 and the exhaust hood 53. Furthermore, the "latent heat recovery part" of the present invention is a part that recovers the latent heat in the combustion exhaust gas, and in this embodiment in the specification, it is a concept including the secondary heat exchanger 6.

[0066] Also, the fixing plate 31 is an example of the "first fixing member", the fixing plate 32 is an example of the "second fixing member", and the flow rectifying plate 70 is an example of the "flow rectifying member" of the present invention. The first fixing part 36 and the second fixing part 37 of the fixing plate 31 are examples of the "first fixing part", and the first fixing part 36 and the second fixing part 37 of the fixing plate 32 are examples of the "second fixing part". The upper part of the first fixing part 36 of the fixing plate 31 and the lower part of the second fixing part 37 of the fixing plate 31 are examples of the "first closing part". The lower part of the first fixing part 36 of the fixing plate 32 and the upper part of the second fixing part 37 of the fixing plate 32 are examples of the "second closing part".

[0067] As described above, the water heater 1 of the present embodiment includes a primary heat exchanger 5, a secondary heat exchanger 6, and a path unit 7. The primary heat exchanger 5 is provided upstream of the combustion exhaust path of a plurality of rich-lean burners housed in the combustion device 4. The primary heat exchanger 5 includes a peripheral wall 51 and an exhaust hood 53. A heat transfer tube 52 is housed in the peripheral wall 51. The primary heat exchanger 5 performs heat exchange between the sensible heat of the combustion exhaust flowing in the peripheral wall 51 and the exhaust hood 53 and the water flowing in the heat transfer tube 52. The secondary heat exchanger 6 is provided downstream of the combustion exhaust path and adjacent to the upper side of the primary heat exchanger 5. The secondary heat exchanger 6 includes a housing 61. A heat transfer tube 62 is housed in the housing 61. The secondary heat exchanger 6 performs heat exchange between the latent heat of the combustion exhaust flowing in the housing 61 and the water flowing in the heat transfer tube 62. An outlet 531 that opens rearward and is long in the left-right direction is provided on the rear wall 530 of the exhaust hood 53 of the primary heat exchanger 5. An inlet 617 that opens rearward and is long in the left-right direction is provided on the rear wall 614 of the housing 61 of the secondary heat exchanger 6.

[0068] The path unit 7 is fixed to these outlet 531 and inlet 617 via a packing 90. The path unit 7 guides the combustion exhaust discharged from the outlet 531 into the housing 61 through the inlet 617. The packing 90 overlaps from the rear with the peripheral portions of the outlet 531 and the inlet 617, and the boundary portion 101 sandwiched vertically between the outlet 531 and the inlet 617. The path unit 7 includes a covering portion 20, a fixing plate 31, a rectifying plate 70, a fixing plate 32, and a connecting plate 80. The covering portion 20 includes a bulging portion 21 and a flange portion 22. The bulging portion 21 bulges rearward. The flange portion 22 extends from the front end portion of the bulging portion 21 verticalIt extends in the left - right direction. The fixing plate 31 is fixed to the back surface of the rectifying plate 70, and the fixing plate 32 is fixed to the front surface. The fixing plate 31 is fixed to the inner surface facing forward of the bulging portion 21. The connecting plate 80 is fixed to the front surface of the flange portion 22 in a state of abutting against the fixing plate 32 from the front, and overlaps the boundary portion 101 from the rear via the packing 90. In such a configuration, the flange portion 22 overlaps from the rear via the packing 90 with respect to the upper side of the inflow port 617, the left and right sides of each of the inflow port 617, the boundary portion 101, and the outflow port 531, and the lower side of the outflow port 531, and is fastened with the packing 90 by the screw 45.

[0069] Thereby, the water heater 1 can suitably crush the packing 90 located behind the boundary portion 101 by the tightening force of the screw 45 through the bulging portion 21, the fixing plate 31, the rectifying plate 70, the fixing plate 32, and the connecting plate 80. Also, since the outflow port 531 and the inflow port 617 are openings that are long in the left - right direction, the boundary portion 101 also becomes long in the left - right direction. In the present embodiment, the connecting plate 80 that overlaps the boundary portion 101 from the rear via the packing 90 is pressed from the rear by the bulging portion 21, the fixing plate 31, the rectifying plate 70, and the fixing plate 32. Thereby, since the connecting plate 80 is in close contact with the packing 90 via the packing 90 also at the central portion of the rectangular boundary portion 101 that is long in the left - right direction, the sealing property at the boundary portion 101 can be ensured. Thereby, the sealing property of the entire path unit 7 can be improved. Therefore, although the water heater 1 has a simple configuration, it can prevent the leakage of combustion exhaust.

[0070] Note that the present invention is not limited to the above - described embodiment, and various modifications are possible. The peripheral wall 51 and the exhaust hood 53 of the primary heat exchanger 5 are separate, but they may be integrated. The shapes of the outflow port 531 and the inflow port 617 do not have to be rectangular. The flange portion 22 of the covering portion 20 is fastened to the rear walls 530, 614 with 10 screws 45, but the number of screws 45 and the fastening positions are not limited to the above - described embodiment. The number of heat transfer tubes 52, 62 extending in the left - right direction is also not limited. The rectifying plate 70 may be omitted. In that case, the fixing plates 31 and 32 may be integrated into one fixing member.

[0071] Moreover, the method for assembling the path unit 7 is not limited to the above-described embodiment. In the above embodiment, the fixing plates 31 and 32 are fixed before and after the rectifying plate 70, and further, the connecting plate 80 fixed to the front side is fixed to the front side of the covering portion 20. However, the order of fixing each member may be changed. For example, after fixing the fixing plates 31 and 32 before and after the rectifying plate 70 to the inside of the covering portion 20, the connecting plate 80 may be fixed from the front side.

[0072] Further, the water heater 1 includes the secondary heat exchanger 6 adjacent to the upper side of the primary heat exchanger 5. However, for example, as shown in FIG. 15, a sensible heat recovery type water heater including an exhaust box 600 instead of the secondary heat exchanger 6 may be used. The exhaust box 600 is provided adjacent to the upper side of the heat exchanger 500. The heat exchanger 500 has the same configuration as the primary heat exchanger 5 and is an example of the "sensible heat recovery portion" of the present invention. The exhaust box 600 has a substantially box shape in which the heat transfer tube 62 is omitted from the inside of the housing 61 of the secondary heat exchanger 6. The exhaust box 600 receives the combustion exhaust flowing from the path unit 7 and discharges it to the outside from the exhaust portion 63. The exhaust box 600 is an example of the "discharge portion" of the present invention. In the case of this configuration, the rectifying plate 70 (see FIG. 5) in the path unit 7 may be omitted, and it is preferable to use a single fixing member 300 in which the fixing plates 31 and 32 are integrated. Even in such a modified example, the same effects as those of the above embodiment can be obtained.

Explanation of reference numerals

[0073] 1 Water heater 5 Primary heat exchanger 6 Secondary heat exchanger 7 Path unit 20 Covering portion 21 Bulging portion 22 Flange portion 26 Recessed portion 31 Fixing plate 32 Fixing plate 45 Screw 53 Exhaust portion 70 Rectifying plate 80 Connecting plate 90 Packing 91 Frame-shaped portion 92 Installing portion 101 boundary part 300 fixing member 500 heat exchanger 530 rear wall 531 outlet 600 exhaust box 614 rear wall 617 inlet

Claims

1. A sensible heat recovery section provided on the upstream side of an exhaust passage through which the combustion exhaust gas of a burner flows, for exchanging sensible heat of the combustion exhaust gas and passing water; A latent heat recovery section provided on the downstream side of the exhaust passage and adjacent to the upper side of the sensible heat recovery section, for exchanging latent heat of the combustion exhaust gas that has passed through the sensible heat recovery section and passing water; A path member fixed via a packing to a rectangular outlet section provided at the rear of the sensible heat recovery section, opening rearward and longer in the left-right direction than in the vertical direction, and a rectangular inlet section provided at the rear of the latent heat recovery section, opening rearward and longer in the left-right direction than in the vertical direction, for guiding the combustion exhaust gas discharged from the outlet section into the latent heat recovery section through the inlet section; Comprising; The packing is; Superposed so as to overlap from the rear on the peripheral portions of each of the inlet section and the outlet section, and on a boundary section sandwiched vertically between the inlet section and the outlet section; The path member is; A main body portion including a bulging portion bulging rearward, and a flange portion protruding in a flange shape outward from the front end portion of the bulging portion and expanding in the vertical direction and the left-right direction; A fixing member fixed to the inner surface facing forward of the bulging portion; A plate-like member fixed to the front surface of the flange portion in a state of being in contact with the fixing member from the front; Comprising; The flange portion is superposed from the rear via the packing on the upper side of the inlet section, the left and right sides of each of the inlet section, the boundary section, and the outlet section, and the lower side of the outlet section, and is fastened with screws together with the packing; The plate-like member superposes from the rear at least on the central portion in the left-right direction of the boundary section in a state where the flange portion is fastened; A water heater characterized by the above.

2. A sensible heat recovery section provided on the upstream side of an exhaust passage through which the combustion exhaust gas of a burner flows, for exchanging sensible heat of the combustion exhaust gas and passing water; A discharge section provided on the downstream side of the exhaust passage and adjacent to the upper side of the sensible heat recovery section, for receiving the combustion exhaust gas that has passed through the sensible heat recovery section and discharging it to the outside; A path member fixed via a packing to a rectangular outlet section provided at the rear of the sensible heat recovery section, opening rearward and longer in the left-right direction than in the vertical direction, and a rectangular inlet section provided at the rear of the discharge section, opening rearward and longer in the left-right direction than in the vertical direction, for guiding the combustion exhaust gas discharged from the outlet section into the discharge section through the inlet section; Comprising; The packing is; Overlap from the rear on the peripheral parts of the inlet part and the outlet part respectively, and on the boundary part sandwiched vertically between the inlet part and the outlet part. The path member has a main body part including a bulging part bulging rearward, and a flange part protruding in a flange shape outward from the front end part of the bulging part and extending in the vertical direction and the horizontal direction. a fixing member fixed to the inner surface facing forward of the bulging part; a plate-like member fixed to the front surface of the flange part while being in contact with the fixing member from the front. and is provided with The flange part overlaps from the rear with respect to the upper side of the inlet part, both left and right sides of the inlet part, the boundary part, and the outlet part, and the lower side of the outlet part via the packing, and is fastened with screws together with the packing. The plate-like member overlaps from the rear with respect to at least the central part in the horizontal direction of the boundary part in a state where the flange part is fastened. A water heater characterized by the above.

3. The plate-like member is fixed at a position sandwiching the bulging part on the front surface of the flange part. The water heater according to claim 1 or 2, characterized by the above.

4. On the front surface of the flange part, in the portion where the plate-like member overlaps, a recess recessed rearward corresponding to the thickness of the plate-like member is formed. The water heater according to claim 3, characterized by the above.

5. The plate-like member extends in the horizontal direction and is installed between both left and right side parts of the flange part. The water heater according to any one of claims 1 to 4, characterized by the above.

6. One or a plurality of protruding parts protruding forward and extending parallel to the length direction of the boundary part are provided on the front surface of the plate-like member. The water heater according to any one of claims 1 to 5, characterized by the above.

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