JP7519085B2 - Relay pipe for water heater - Google Patents

Description

This disclosure relates to relay pipes for water heaters.

Patent Document 1 discloses a water heater. The water heater in Patent Document 1 is provided with a horizontally long side exhaust pipe. The horizontally long side exhaust pipe is installed in front of the appliance, and a combustion exhaust outlet is provided at one end in the longitudinal direction so that the exhaust direction can be directed to either the left or right side at the front of the appliance. An exhaust connection port that is larger than the exhaust connection port and reaches the upper and lower inner surfaces of the side exhaust pipe is provided on the back surface of the side exhaust pipe, and is connected to the exhaust inlet port.

JP 2005-214502 A

When installing a water heater in an apartment building, it is often necessary to fix the water heater inside a pipe shaft with a door in which gas and water pipes are installed. In this case, it is necessary to connect the water heater's exhaust port inside the door to the exhaust guide inside the door via a relay pipe that passes through the door's through window from the inside to the outside.

An example of a relay pipe is one with flange members provided near both ends of the tubular portion. With such a shape, a fixing structure can be adopted to fix each flange member to the water heater body and the exhaust adapter, respectively, which is advantageous in terms of stable fixing.
However, simply adopting this configuration poses problems in terms of workability. For example, simply providing flange members near both ends of the tubular portion makes it difficult to determine which flange member is to be fixed to the main body and which flange member is to be fixed to the exhaust adapter. Also, when one flange member is to be fixed to the water heater main body with a fastening member, the other flange member may get in the way and make it difficult to insert the fastening member. Also, it is necessary to prepare flange members of different shapes for the water heater side and the exhaust guide side, which is disadvantageous in terms of cost.

In order to solve at least one of the problems described above, the present disclosure has an objective of providing a relay pipe for a water heater that can be interposed between the main body of the water heater and the exhaust adapter, making it easier to install.

The relay pipe for a water heater according to the present disclosure is
A relay pipe that is attached between a main body of a water heater and an exhaust adapter,
A cylindrical portion configured in a cylindrical shape centered on a central axis in a predetermined direction;
a first flange member extending from one end of the cylindrical portion;
a second flange member extending from the other end of the cylindrical portion;
Equipped with
the first flange member has a first hole portion disposed on one side of the central axis in a first reference direction perpendicular to the predetermined direction, a second hole portion disposed on the other side of the central axis in the first reference direction, and a first recess and a second recess recessed toward the central axis at an outer edge of the first flange member,
the second flange member has a third hole portion disposed on one side of the central axis in a second reference direction perpendicular to the predetermined direction, a fourth hole portion disposed on the other side of the central axis in the second reference direction, and a third recess and a fourth recess recessed toward the central axis at an outer edge of the second flange member,
when the first flange member is fixed to the main body portion, the third recess is disposed in front of the first hole portion, the fourth recess is disposed in front of the second hole portion, and the first hole portion and the second hole portion serve as holes into which a fastening member to be fixed to the main body portion is inserted,
When the second flange member is fixed to the main body portion, the first recess is positioned in front of the third hole portion, the second recess is positioned in front of the fourth hole portion, and the third hole portion and the fourth hole portion serve as holes for inserting a fastening member fixed to the main body portion.

The relay pipe for a water heater, which is one aspect of the present disclosure, can be placed between the main body of the water heater and the exhaust adapter, making it easier to install.

FIG. 1 is a perspective view that diagrammatically illustrates a water heater according to a first embodiment. FIG. 2 is an explanatory diagram illustrating the configuration of the hot water supply device of FIG. FIG. 3 is an exploded perspective view of the hot water supply device of FIG. 1 with some parts omitted. FIG. 4 is an enlarged perspective view showing a portion of the hot water heater of FIG. 1 . FIG. 5 is an enlarged view showing a part of the front view of the water heater of FIG. 1 . FIG. 6 is a cross-sectional view of the water heater of FIG. 1 cut in a direction perpendicular to the left-right direction at the center position in the left-right direction, with some components omitted. FIG. 7 is an enlarged cross-sectional view showing a part of FIG. FIG. 8 is an enlarged cross-sectional view showing a part of FIG. FIG. 9 is a perspective view mainly showing a housing main body and a heat exchanger of the hot water supply device of FIG. FIG. 10 is a front view mainly showing the housing main body and the heat exchanger of the hot water supply device of FIG. FIG. 11 is a perspective view mainly showing the housing main body, the heat exchanger, and the rear plate of the hot water supply device of FIG. FIG. 12 is a front view mainly showing the housing main body, the heat exchanger, and the rear plate of the hot water supply device of FIG. FIG. 13 is a perspective view mainly showing the housing main body, the heat exchanger, and the exhaust top of the hot water heater of FIG. FIG. 14 is a front view mainly showing the housing main body, the heat exchanger, and the exhaust top of the hot water supply device of FIG. FIG. 15 is a partially enlarged perspective view of the water heater of FIG. 1 with the relay pipe and the exhaust adaptor removed. FIG. 16 is a partially enlarged front view of the water heater of FIG. 1 with the relay pipe and the exhaust adaptor removed. 17 is a partially enlarged perspective view of the water heater of FIG. 1 with the exhaust adaptor removed. FIG. FIG. 18 is a partially enlarged front view of the water heater of FIG. 1 with the exhaust adaptor removed. FIG. 19 is a partially enlarged perspective view of the water heater of FIG. 1 with the exhaust adaptor cover removed. 20 is a partially enlarged front view of the water heater of FIG. 1 with the exhaust adaptor cover removed. FIG. FIG. 21 is a perspective view illustrating an example of a relay pipe attached to a hot water supply apparatus. FIG. 22 is a diagram showing the configuration of the relay pipe in FIG. 21 as viewed from the front side, with one of the flange members omitted. FIG. 23 is a diagram showing the configuration of the relay pipe in FIG. 21 as viewed from the rear side, with the other flange member omitted. FIG. 24 is a diagram showing the configuration of one of the flange members of the relay pipe in FIG. 21 as viewed from the front side, with the other flange member omitted by an imaginary line. FIG. 25 is a perspective view that illustrates a schematic example of an aspect in which no relay pipe is provided in the hot water heater of the first embodiment. FIG. 26 is a cross-sectional view of the water heater of FIG. 25 cut at the center in the left-right direction in a direction perpendicular to the left-right direction, with some components omitted. FIG. 27 is an enlarged cross-sectional view showing a part of FIG. 28 is a partially enlarged front view of the water heater of FIG. 25 with the cover of the exhaust adaptor removed.

Below, embodiments of the present disclosure are listed and illustrated.

[1] A relay pipe that is attached between a main body of a water heater and an exhaust adapter,
A cylindrical portion configured in a cylindrical shape centered on a central axis in a predetermined direction;
a first flange member extending from one end of the cylindrical portion;
a second flange member extending from the other end of the cylindrical portion;
Equipped with
the first flange member has a first hole portion disposed on one side of the central axis in a first reference direction perpendicular to the predetermined direction, a second hole portion disposed on the other side of the central axis in the first reference direction, and a first recess and a second recess recessed toward the central axis at an outer edge of the first flange member,
the second flange member has a third hole portion disposed on one side of the central axis in a second reference direction perpendicular to the predetermined direction, a fourth hole portion disposed on the other side of the central axis in the second reference direction, and a third recess and a fourth recess recessed toward the central axis at an outer edge of the second flange member,
when the first flange member is fixed to the main body portion, the third recess is disposed in front of the first hole portion, the fourth recess is disposed in front of the second hole portion, and the first hole portion and the second hole portion serve as holes into which a fastening member to be fixed to the main body portion is inserted,
When the second flange member is fixed to the main body portion, the first recess is positioned in front of the third hole portion, the second recess is positioned in front of the fourth hole portion, and the third hole portion and the fourth hole portion serve as holes for inserting a fastening member fixed to the main body portion.A relay pipe for a water heater.

The relay pipe for the water heater in [1] above is configured so that it can be attached by fixing the first flange member to the main body, and also configured so that it can be attached by fixing the second flange member to the main body. Therefore, this relay pipe is easy to work with. Moreover, when either flange member is attached to the main body, the recess (recess recessed toward the central axis) of the other flange member is located in front of the "hole for inserting the fastening member to be fixed to the main body" formed in that flange member, making it easy to insert the fastening member.

[2] The relay pipe for the water heater described in [1] above has the following features. When the first flange member is fixed to the main body, the first reference direction is the vertical direction. When the second flange member is fixed to the main body, the second reference direction is the vertical direction. The exhaust adapter is attached in an arrangement extending in a direction intersecting the predetermined direction and the vertical direction.

The relay pipe for the water heater described above in [2] can be fixed by inserting fastening members into holes on both the top and bottom of the flange members, whether the first flange member is fixed to the main body or the second flange member is fixed to the main body. Therefore, in a configuration in which both flange members can be fixed, they can be stably fixed from the top and bottom in either case.

[3] The relay pipe for the water heater described in [1] or [2] above has the following features: The shape of the second flange member is an inverted shape of the first flange member.

The relay pipe for the water heater described above in [3] has a common shape for the first flange portion and the second flange member, which simplifies manufacturing and management and makes it easier to reduce costs.

[4] The relay pipe for the water heater described in any one of [1] to [3] above has the following features. The water heater is attached to the front panel and has a protruding portion that protrudes forward from the front panel. A flat surface is provided on the front surface of the protruding portion. A circular exhaust port and a plurality of holes provided around the exhaust port are formed in the flat surface. The plurality of holes include a first fastening hole portion to which a fastening member inserted into the first flange member or the second flange member is fixed when the first flange member or the second flange member is fixed to the flat surface, and a second fastening hole portion to which a fastening member inserted into the exhaust adapter is fixed when the exhaust adapter is directly fixed to the flat surface. When either the first flange member or the second flange member is fixed to the flat surface, the flange member is arranged in a configuration in which the flange member blocks the second fastening hole portion.

The relay pipe for the water heater described above in [4] can be applied to a water heater that can select between a method of fixing the exhaust adapter via the relay pipe and a method of fixing the exhaust adapter without using the relay pipe. Moreover, when using a method of fixing the exhaust adapter via the relay pipe, the hole (second fastening hole) used in the method of directly fixing the exhaust adapter without using the relay pipe can be blocked. Therefore, while realizing a configuration that allows the selection of which of the first flange member and the second flange member to be fixed to the main body, and a configuration that allows the selection of a method of directly fixing the exhaust adapter and a method of indirectly fixing the exhaust adapter, when attaching the relay pipe, leakage of exhaust gas, etc. through the second fastening hole can be suppressed regardless of which flange member is fixed.

First Embodiment
The following description relates to the first embodiment.
(Overview of hot water supply equipment)
The hot water supply device (hot water heater) 1 shown in Fig. 1 has a function of heating tap water supplied from the outside and discharging hot water. As shown in Fig. 2, the hot water supply device 1 includes a gas burner 2, a water inlet pipe 4, a hot water outlet pipe 6, a heat exchanger 8, a connecting pipe 15, and the like. The heat exchanger 8 includes a primary heat exchanger 9 and a secondary heat exchanger 10. The heat exchanger 8 functions to recover sensible heat of the combustion exhaust gas by the primary heat exchanger 9, and then recover latent heat by the secondary heat exchanger 10. The primary heat exchanger 9 is configured such that a heat transfer pipe section 13 constituting a part of the hot water supply side heat transfer pipe section 11 and a heat transfer pipe section 113 constituting a part of the bath side heat transfer pipe section 111 are housed inside a box-shaped case (not shown) in a form partitioned by a partition wall. The secondary heat exchanger 10 is configured so that a heat transfer tube section 12 constituting part of the hot water side heat transfer tube section 11 and a heat transfer tube section 113 constituting part of the bath side heat transfer tube section 111 are housed inside a box-shaped case 10A (Figure 3, etc.) and are separated by a partition wall.

The gas burner 2 burns the combustion gas to generate combustion exhaust. The water inlet pipe 4 is configured as a path into which water flows from the water inlet 16. The hot water outlet pipe 6 is configured as a path for sending hot water to the hot water outlet 18. In the heat exchanger 8, the hot water supply side heat transfer pipe section 11 is interposed between the water inlet pipe 4 and the hot water outlet pipe 6. When heat exchange is performed in the hot water supply side circuit, the heat exchanger 8 transfers heat generated by combustion in the gas burner 2 to the water passing through the inside of the hot water supply side heat transfer pipe section 11. The heat transfer pipe section 12 of the hot water supply side heat transfer pipe section 11 is provided in the secondary heat exchanger 10, and the heat transfer pipe section 12 is connected to the downstream side of the water inlet pipe 4. The connecting pipe 15 is connected to the downstream side of the heat transfer pipe section 12. The heat transfer pipe section 13 of the hot water supply side heat transfer pipe section 11 is provided in the primary heat exchanger 9, and the heat transfer pipe section 13 is connected to the downstream side of the connecting pipe 15. The outlet pipe 6 is connected to the downstream side of the heat transfer pipe section 13.

The water heater 1 is equipped with a gas burner 102, pipes 104, 106, a connecting pipe 115, etc., and has a function of reheating the bath using a heat exchanger 8. In the heat exchanger 8, the bath side heat transfer pipe section 111 is interposed between the pipes 104 and 106. The heat transfer pipe section 112 of the bath side heat transfer pipe section 111 is provided in the secondary heat exchanger 10, and the heat transfer pipe section 112 is connected to the downstream side of the pipe 104. The connecting pipe 115 is connected to the downstream side of the heat transfer pipe section 112. The heat transfer pipe section 113 of the bath side heat transfer pipe section 111 is provided in the primary heat exchanger 9, and the heat transfer pipe section 113 is connected to the downstream side of the connecting pipe 115. The pipe 106 is connected to the downstream side of the heat transfer pipe section 113.

The water heater 1 is equipped with a drain pipe 22 and a neutralizer 24. Furthermore, the water heater 1 is equipped with a controller 28 as a control device.

(Details of the front panel area)
As shown in FIG. 1, the water heater 1 has a main body 1A and an exhaust adapter 130. The water heater 1 is configured such that the exhaust adapter 130 is attached to the main body 1A from the outside. The main body 1A is the part of the water heater 1 excluding the exhaust adapter 130. In the example of FIG. 1, the part of the water heater 1 excluding the exhaust adapter 130 and the relay pipe 120 is the main body 1A. In the example of FIG. 19, the part of the water heater 1 excluding the exhaust adapter 130 is the main body 1A. The main body 1A has a housing 30 and various parts housed in the housing 30. The parts housed in the housing 30 are various parts shown in FIG. 2, such as the heat exchanger 8, the gas burners 2, 102, and the controller 28.

3, the housing 30 includes a housing body 32 and a front panel 33. The housing body 32 is a box-shaped case body with an open front end. The housing body 32 is made of, for example, a metal material. The inside of the housing body 32 is configured as a storage space that accommodates the various components described above. The housing body 32 includes an upper plate 34, side plates 35 and 36, a back plate 37, and a bottom plate 38. The upper plate 34 is an upper wall portion that constitutes the upper surface of the housing 30. The bottom plate 38 is a lower wall portion that constitutes the bottom surface of the housing 30. The side plates 35 and 36 are a pair of left and right side walls of the housing 30. The back plate 37 is a rear wall portion that constitutes the rear surface of the housing 30. The upper plate 34 and the bottom plate 38 are provided on both sides of the upper and lower directions of the storage space. The pair of side plates 35 and 36 are provided on both sides of the left and right directions of the storage space. The back plate 37 is provided on the rear side of the storage space. FIG. 3 illustrates a secondary heat exchanger 10 as an example of a component housed in the housing body 32. In the following description, the secondary heat exchanger 10 is also simply referred to as the heat exchanger 10.

The front panel 33 is a front wall that constitutes the front part of the housing 30, and is a plate-like body. The front panel 33 is made of, for example, a metal material. One surface of the front panel 33 constitutes the front part of the main body 1A. The front panel 33 is attached to the housing main body 32 so as to close the open end 32A provided at the front end of the housing main body 32. The front panel 33 is fixed to the housing main body 32 by a connecting member such as a screw or a bolt. The front panel 33 is configured as a square plate with a flange formed on the periphery. The front panel 33 is formed with a through hole portion 33A. The through hole portion 33A is configured as a substantially circular hole that penetrates the plate-like body (e.g., a metal plate) that constitutes the front panel 33 in the front-rear direction. The protruding portion 62 described later is inserted into the through hole portion 33A.

In this embodiment, the direction in which the top plate 34 and the bottom plate 38 face each other is the up-down direction of the water heater 1. The up-down direction is, for example, a direction along the vertical up-down direction. The up-down direction is also the direction in which each of the pair of side plates 35, 36 extends. The direction perpendicular to the up-down direction and in which the pair of side plates 35, 36 face each other is the left-right direction of the water heater 1. The left-right direction is the direction in which the top plate 34 and the bottom plate 38 extend. The direction perpendicular to the up-down direction and the left-right direction and in which the front panel 33 and the back plate 37 face each other is the front-rear direction of the water heater 1.

3 and 6, the heat exchanger 10 housed in the housing 30 includes a case 10A through which exhaust gas passes, and a heat transfer tube portion 11. The heat exchanger 10 is configured so that exhaust gas passes through the inside of the case 10A. As shown in Figs. 6, 9, and 10, the case 10A is box-shaped. The case 10A includes a front wall portion 10B and a rear wall portion 10C that face each other in the front-rear direction, and a pair of side walls 10F, 10G that face each other in the left-right direction. Furthermore, the case 10A includes a lid portion 10D, and the lid portion 10D and a bottom wall portion 10E that face each other in the top-bottom direction. The case 10A is configured such that the front wall portion 10B, the rear wall portion 10C, and a pair of side walls 10F and 10G are connected to rise from the bottom wall portion 10E in a form that forms a peripheral wall portion around the storage space, and has a box-like configuration with an open upper end, and a lid portion 10D is arranged in a configuration that closes the opening at the upper end. The heat transfer tube portion 11 is accommodated inside the case 10A. The case 10A has a box-like configuration that surrounds both the front and rear sides, both the left and right sides, and both the top and bottom sides of the storage space that accommodates the heat transfer tube portion 11, and is configured such that exhaust gas passes through the storage space. The rear wall portion 10C of the case 10A has an opening 10J for guiding exhaust gas into the case 10A. The front wall portion 10B of the case 10A has an opening 10H for discharging exhaust gas that has passed through the case 10A. That is, exhaust gas is introduced into the case 10A through the opening 10J, passes through the case 10A, and flows toward the opening 10H on the front side. As shown in FIG. 3, the case 10A is shaped like a box that is long in the left-right direction, and the opening 10H is formed as a long and narrow hole along the left-right direction.

As shown in Figures 3, 7, and 8, the exhaust top 40 is fixed to the front wall portion 10B of the heat exchanger 10. The exhaust top 40 forms the exhaust path on the front side of the heat exchanger 10. The exhaust top 40 has a rear plate portion 42 fixed to the front wall portion 10B, and a front plate portion 60 overlapping the rear plate portion 42 from the front side. The exhaust top 40 has a protruding portion 62 described below, and is configured to introduce exhaust gas discharged from the opening portion 10H and guide it to an exhaust port 66 formed in the protruding portion 62.

As shown in FIG. 3, the rear plate portion 42 is formed in a plate shape. The rear plate portion 42 is fixed to the front wall portion 10B of the heat exchanger 10 arranged as shown in FIG. 9 and FIG. 10 as shown in FIG. 11 and FIG. 12. The method of fixing the rear plate portion 42 to the front wall portion 10B is, for example, a method of fixing both members by fastening members such as screws and bolts. Note that the fastening members are not shown in FIG. 11 and FIG. 12. In order to further ensure the prevention of exhaust gas leakage, a packing (not shown) may be provided around the opening 10H between the front wall portion 10B and the rear plate portion 42 in a configuration sandwiched between the front wall portion 10B and the rear plate portion 42.

The rear plate 42 is formed with an inlet 42A for introducing exhaust gas discharged from inside the case 10A through the opening 10H. The rear plate 42 has a plate 44 in which the inlet 42A is formed, and a bent portion 46 that bends forward from the upper edge of the inlet 42A in the plate 44. In the example of Figures 11 to 13, the inlet 42A extends elongatedly in the left-right direction, and the bent portion 46 also extends in the left-right direction. The base end (root portion) of the bent portion 46, which is the boundary between the plate 44 and the bent portion 46, constitutes at least a part of the upper edge of the inlet 42A.

As shown in FIG. 14, the bent portion 46 is provided at a position overlapping the opening area of the exhaust port 66 in the front-rear direction. When viewed from the front as in FIG. 14, at least a part of the bent portion 46 (all of it in the example of FIG. 14) is located inside the inner edge of the exhaust port 66. As shown in FIGS. 11 to 13, the bent portion 46 is provided along the upper edge portion 10Z of the opening 10H in front of the opening 10H. The upper edge portion 10Z is configured as an inner edge portion that extends linearly along the left-right direction. The bent portion 46 has a plate piece 46A that extends forward from the upper edge portion of the inlet 42A. The plate piece 46A is bent at a right angle to a predetermined portion (a portion to which the plate piece 46A is connected) of the plate portion 44 and protrudes forward along the front-rear direction. The thickness direction of the plate piece 46A is a direction along the vertical direction, and for example, the thickness direction of the plate piece 46A coincides with the vertical direction. The bent portion 46 is a part that contributes to suppressing noise.

11, 12, and 14, the rear plate portion 42 is provided with the opening area enlargement portions 48A and 48B at a position shifted in the left-right direction from the bent portion of the inlet 42A, with the upper edge of the inlet 42A positioned above the bent portion. The opening area enlargement portions 48A and 48B are at least provided at a position shifted to one side in the left-right direction from the end portion on one side of the left-right direction of the exhaust port 66, or at a position shifted to the other side in the left-right direction from the end portion on the other side of the left-right direction of the exhaust port 66. In FIG. 12 and FIG. 14, the area AR1 is the left-right range of the bent portion 46. The area AR2 is the left-right range of the opening area enlargement portion 48A. The area AR3 is the left-right range of the opening area enlargement portion 48B. The area AR is the left-right range of the inlet 42A. The area AR4 is the left-right range of the exhaust port 66. Area AR5 is the range in the up-down direction of inlet 42A and also the range in the up-down direction of opening area expansion portions 48A and 48B. Area AR5 is the range in the up-down direction of exhaust port 66.

The front plate 60 is fixed to the rear plate 42 arranged as shown in Figs. 11 and 12 as shown in Figs. 13 and 14. The front plate 60 is fixed to the rear plate 42 by, for example, fastening members such as screws and bolts, or by riveting. In order to further ensure the prevention of exhaust gas leakage, a packing (not shown) may be provided between the periphery of the rear plate 42 and the periphery of the front plate 60, sandwiched between the rear plate 42 and the front plate 60. Note that the fastening members and other fixing parts are not shown in Figs. 13 and 14. The front plate 60 arranged as shown in Figs. 13 and 14 is then attached to the front panel 33 as shown in Figs. 15 and 16.

The front plate 60 is provided with a plate 61 and a protruding portion 62. The plate 61 is a flat portion configured with its thickness direction being in the front-to-rear direction. The plate 61 is fixed to the peripheral portion around the inlet 42A of the plate 44 of the rear plate 42 in such a manner that the plate surface is in close contact with the surface of the peripheral portion. As shown in Figures 15 and 16, the plate 61 is disposed behind the front panel 33 so as to be covered by the front panel 33.

The protruding portion 62 is a portion that is attached to the front panel 33 as shown in Figs. 15 and 16. The protruding portion 62 protrudes forward from the front surface of the plate portion 61. As shown in Figs. 15 and 16, the protruding portion 62 has a convex configuration that bulges forward so as to be inserted into the through-hole portion 33A formed in the front panel 33. The protruding portion 62 protrudes forward from the surface (front surface) of the front panel 33 in front of the inlet 42A (see also Fig. 8). An exhaust port 66 is formed in the protruding portion 62. A flat portion 64 is provided on the front surface of the protruding portion 62.

The planar portion 64 is a planar portion whose front surface is configured as a flat surface 64Z. The front surface of the planar portion 64 (flat surface 64Z) is a flat surface along a predetermined first direction and a second direction perpendicular to the first direction. In this embodiment, the first direction is the up-down direction, and the second direction is the left-right direction. In other words, the flat surface 64Z is a flat surface in a planar direction perpendicular to the front-rear direction.

As shown in Figures 15 and 16, an exhaust port 66 is formed in the flat surface portion 64. The exhaust port 66 is a circular opening, and is a circular hole that penetrates in the front-rear direction. The shape of the edge of the exhaust port 66 on the surface (front surface) of the flat surface portion 64 (the shape of the outer edge of the opening area of the exhaust port 66) is, for example, a circle of a predetermined diameter centered on a predetermined position C1. The flat surface portion 64 is provided around the exhaust port 66 in the protruding portion 62. The exhaust port 66 is provided eccentrically on one side (specifically, the upper side) of the first direction (up-down direction) in the flat surface portion 64.

16, the flat surface portion 64 is provided with a first protruding portion 64A and a second protruding portion 64B. The flat surface portion 64 has a width X1 on one side (upper side) in the first direction greater than the exhaust port 66, and a width X2 on the other side (lower side) in the first direction greater than the exhaust port 66. Specifically, the vertical distance between the lower end of the exhaust port 66 and the lower end of the flat surface portion 64 is greater than the vertical distance between the upper end of the exhaust port 66 and the upper end of the flat surface portion 64. 16, a vertical reference line G1 is set that passes through the center C1 of the exhaust port 66 and extends above the center C1, and a first imaginary straight line L1 is set by rotating the reference line G1 clockwise about the center C1 by α° (where 0<α<90°), and a second imaginary straight line L2 is set by rotating the reference line G1 counterclockwise about the center C1 by β° (where 0<β<90°). The first protrusion 64A is provided at a position intersecting the first imaginary straight line L1. The second protrusion 64B is provided at a position intersecting the second imaginary straight line L2.

The area around the end of the exhaust port 66 on one side in the first direction (the area around the upper end of the flat portion 64) that is relatively narrow corresponds to an example of the first area. The area around the end of the exhaust port 66 on the other side in the first direction (the area around the lower end of the flat portion 64) that is relatively wider than the first area corresponds to an example of the second area. The wide portion formed in the second area of the flat portion 64 is the wide portion 64C. The first protruding portion 64A is provided on the flat portion 64 on one side in the first direction (upper side) of the center C1 of the exhaust port 66 and on one side in the second direction (right side in FIG. 16) of the first area. The first protruding portion 64A protrudes in a direction away from the center C1 in the radial direction. More specifically, the radial width of a part of the first protruding portion 64A centered on the center C1 is larger than the radial width of the first area and is larger than the radial width of the wide portion 64C. The second protruding portion 64B is provided on one side in the first direction (upper side) of the center C1 of the exhaust port 66 and on the other side in the second direction (left side in FIG. 16) of the first region. The second protruding portion 64B protrudes in a direction away from the center C1 in the radial direction. More specifically, the radial width of a portion of the second protruding portion 64B is greater than the radial width of the first region and is greater than the radial width of the wide portion 64C.

15 and 16, a plurality of holes 68 are formed around the exhaust port 66 in the flat portion 64 for inserting fastening members 190 (FIGS. 19, 25 to 27) used to fix the exhaust adapter 130. The fastening members 190 are connecting members such as screws and bolts. Among the plurality of holes 68, holes 68A and 68B are formed in the first region in the flat portion 64. Among the plurality of holes 68, holes 68C and 68D are formed in the second region in the flat portion 64. The holes 68A, 68B, 68C, and 68D are holes into which the fastening members 190 are inserted when the exhaust adapter 130 is fixed directly to the flat portion 64 without using the relay pipe 120 as in FIGS. 25 to 28. Among the plurality of holes 68, hole 68E is formed in the first protruding portion 64A. Of the multiple holes 68, hole 68F is formed in the second protruding portion 64B. Of the multiple holes 68, holes 68G and 68H are formed in the wide portion 64C. As shown in FIG. 19, holes 68E, 68F, 68G, and 68H correspond to an example of a screw hole portion for fastening a fastening member 180 (screw member) used to fasten the relay pipe 120. Fastening member 180 is a connecting member such as a screw or a bolt.

As shown in FIG. 14, at least a part of the flat portion 64 is provided at a position above the inlet 42A, and at least one of the holes 68 (specifically, the holes 68A and 68B) is arranged at a position above the inlet 42A. The end of the exhaust port 66 on one side in the left-right direction is arranged on the other side in the left-right direction than the end of the inlet 42A on one side in the left-right direction. For example, the left end of the exhaust port 66 when viewed from the front as in FIG. 14 is arranged to the right of the left end of the inlet 42A. The end of the exhaust port 66 on the other side in the left-right direction is arranged to one side in the left-right direction than the end of the inlet 42A on the other side in the left-right direction. For example, the right end of the exhaust port 66 when viewed from the front as in FIG. 16 is arranged to the left of the right end of the inlet 42A. The upper end of the exhaust port 66 is arranged at a position above the upper end of the inlet 42A, and the lower end of the exhaust port 66 is arranged at a position below the lower end of the inlet 42A. The upper end of the exhaust port 66 is positioned above the bent portion 46 and above the enlarged opening area portions 48A and 48B. A portion of the opening area of the exhaust port 66 overlaps with a portion of the opening area of the inlet port 42A in the front-rear direction.

The flat surface 64 can be used in both a configuration in which the exhaust adapter 130 is fixed directly to the flat surface 64 without using the relay pipe 120, as shown in Figures 25 to 28, and a structure in which the relay pipe 120 is fixed to the flat surface 64 (a structure in which the exhaust adapter 130 is fixed indirectly via the relay pipe 120), as shown in Figures 1 to 8, etc.

The configuration shown in Figures 1 to 8 etc. is a configuration in which the exhaust adapter 130 is indirectly fixed to the flat surface portion 64 by interposing an intermediate pipe 120 between the exhaust adapter 130 and the flat surface portion 64. When the exhaust adapter 130 is fixed to the main body portion 1A via the intermediate pipe 120 as in Figures 1, 7 and 8, the flat surface portion 64 is fixed to the first flange member 122 by a fastening member 180 such as a screw member as in Figures 4 and 19, overlapping the first flange member 122 of the intermediate pipe 120 from front to rear as in Figure 8.

When the water heater is installed in a pipe shaft (not shown) with a door, the relay pipe 120 is interposed between the exhaust port on the water heater side and the exhaust adapter in a manner that penetrates the through window of the door from front to back, and is configured as shown in Figures 21 to 24. Note that in Figure 7, a door with a through window is virtually shown by a two-dot chain line, and an example is shown in which the relay pipe 120 is arranged in a manner that penetrates this door. The relay pipe 120 is a pipe that is attached between the main body 1A and the exhaust adapter 130. The relay pipe 120 includes a cylindrical portion 126, a first flange member 122, and a second flange member 124. The first flange member 122 is also simply referred to as the first flange member 122. The second flange member 124 is also simply referred to as the second flange member 124.

The cylindrical portion 126 is a portion configured in a cylindrical shape centered on a central axis C2 in a predetermined direction.
21 to 24, the tubular portion 126 is a cylinder. The central axis C2 is an axis that is in the front-to-rear direction when the relay pipe 120 is attached to the water heater 1. Regardless of whether the first flange member 122 is attached to the main body portion 1A or the second flange member 124 is attached to the main body portion 1A, the central axis C2 is arranged to be in the front-to-rear direction.

The first flange member 122 is an annular, plate-like portion that protrudes from one end of the tubular portion 126. The first flange member 122 is fixed to one end of the tubular portion 126 in the direction of the central axis C2, and protrudes in a flange-like shape from the one end. The first flange member 122 has a plate-like shape along a planar direction perpendicular to the central axis C2. The second flange member 124 is an annular, plate-like portion that protrudes from the other end of the tubular portion 126. The second flange member 124 is fixed to the other end of the tubular portion 126 in the direction of the central axis C2, and protrudes in a flange-like shape from the other end. The second flange member 124 has a plate-like shape along a planar direction perpendicular to the central axis C2. The shape of the second flange member 124 is an inverted shape of the first flange member 122. That is, the shape of the first flange portion 122 as viewed from one side in the direction of the central axis C2 as shown in Fig. 23 is the same as the shape of the second flange portion 124 as viewed from the other side in the direction of the central axis C2 as shown in Fig. 22. Specifically, the shape of the first flange portion 122 as viewed from one side in the direction of the central axis C2 as shown in Fig. 23 and the shape of the second flange portion 124 as viewed from the other side in the direction of the central axis C2 as shown in Fig. 22 are configured so that the outer shapes are the same when the center (position of the central axis C2) of the first flange portion 122 and the first reference direction B1 are aligned with the center (position of the central axis C2) of the second flange portion 124 and the second reference direction B2, respectively. Therefore, the relay pipe 120 has the same shape even if the first flange member 122 side and the second flange member 124 side are reversed. The shape of the second flange member 124 shown in Fig. 22 and the shape of the first flange member 122 shown in Fig. 23 adopt the same common shape. The first reference direction B1 is a predetermined direction passing through the central axis C2 in the common shape, and the second reference direction B2 is also a predetermined direction passing through the central axis C2 in the common shape. That is, the first reference direction B1 and the second reference direction B2 are the same direction in the common shape. Both Fig. 22 and Fig. 24 are shapes seen from the other side in the direction of the central axis C2, and Fig. 22 focuses on the second flange portion 124, and Fig. 24 focuses on the first flange portion 122. When seen from the other side in the direction of the central axis C2 as in Fig. 24, the first flange portion 122 has a shape that is an inverted version of the second flange portion 124, and the first flange portion 122 and the second flange portion 124 are connected to both ends of the tube portion 126 in a positional relationship in which the first reference direction B1 and the second reference direction B2 form a predetermined angle θ3. In addition, in Fig. 24, the second flange portion 124 is virtually shown by a two-dot chain line. Fig. 24 virtually shows the second flange portion 124 by a two-dot chain line in the structure of the relay pipe 120 viewed from the second flange portion 124 side, but the structure of the relay pipe 120 viewed from the first flange portion 122 side (the arrangement in which the arrangement in Fig. 24 is reversed) is the same structure, in which the part shown by the two-dot chain line in Fig. 24 is replaced by the first flange portion 122, and the part shown by the solid line in Fig. 24 is replaced by the second flange portion 124.

Figure 23 is a view of the first flange member 122 from the opposite side to the second flange member 124. Figure 24 is a view of the first flange member 122 from the second flange member 124 side. As shown in Figures 23 and 24, the first flange member 122 has a plurality of through holes 123A, 123B, 123C, 123D, 123E, 123F, 123G, and 123J formed therein. The plurality of through holes 123A, 123B, 123C, 123D, 123E, 123F, 123G, and 123J penetrate the first flange member 122 in the thickness direction (the direction of the central axis C2). Furthermore, the first flange member 122 has a plurality of recesses 123K, 123L, 123M, and 123N formed therein. The multiple recesses 123K, 123L, 123M, and 123N are formed such that the outer edge of the first flange member 122 is recessed toward the central axis C2. The through holes 123E and 123F correspond to an example of a first hole portion. The through holes 123E and 123F are arranged on one side of the first reference direction with respect to the central axis C2. The first reference direction is a direction perpendicular to the central axis C2. In Figures 23 and 24, a virtual line extending in the first reference direction is indicated by the symbol B1. The through holes 123G and 123H correspond to an example of a second hole portion. The through holes 123G and 123H are arranged on the other side of the first reference direction with respect to the central axis C2. The recesses 123K and 123L correspond to an example of a first recess. The recesses 123M and 123N correspond to an example of a second recess.

22, the second flange member 124 has a plurality of through holes 125A, 125B, 125C, 125D, 125E, 125F, 125G, and 125J formed therein. The plurality of through holes 125A, 125B, 125C, 125D, 125E, 125F, 125G, and 125J penetrate the second flange member 124 in the thickness direction (the direction of the central axis C2). Furthermore, the second flange member 124 has a plurality of recesses 125K, 125L, 125M, and 125N formed therein. The plurality of recesses 125K, 125L, 125M, and 125N form a recessed shape in which the outer edge of the second flange member 124 is recessed toward the central axis C2 side. The through holes 125E and 125F correspond to an example of a third hole portion. The through holes 125E and 125F are disposed on one side of the second reference direction with respect to the central axis C2. The second reference direction is a direction perpendicular to the central axis C2 and different from the first reference direction. In Figs. 22 to 24, a virtual line extending in the second reference direction is indicated by the symbol B2. The through holes 125G and 125H correspond to an example of a fourth hole portion. The through holes 125G and 125H are disposed on the other side of the second reference direction with respect to the central axis C2. The recesses 125K and 125L correspond to an example of a third recess. The recesses 125M and 125N correspond to an example of a fourth recess.

16, holes 68E, 68F, 68G, and 68H are examples of first fastening holes. Holes 68E, 68F, 68G, and 68H are holes to which fastening members (fastening members 180 in FIG. 19) inserted into the first flange member 122 or the second flange member 124 are fixed when the first flange member 122 or the second flange member 124 is fixed to the flat portion 64 as shown in FIG. 19 are fixed. Among the multiple holes, holes 68A, 68B, 68C, and 68D are examples of second fastening holes. Holes 68A, 68B, 68C, and 68D are holes to which fastening members (fastening members 190 in FIG. 28) inserted into the exhaust adapter 130 are fixed when the exhaust adapter 130 is directly fixed to the flat portion 64 as shown in FIG. 28 are fixed. When either the flange portion of the first flange member 122 or the second flange member 124 is fixed to the flat portion 64 as shown in FIG. 19, the flange portion is arranged in a configuration that blocks the holes 68A, 68B, 68C, and 68D (second fastening hole portions).

When the first flange member 122 is fixed to the flat portion 64 and the second flange member 124 is fixed to the exhaust portion 140 as shown in Figures 1 and 17 to 20, the first reference direction B1 is the up-down direction as shown in Figures 18, 22, and 24. Then, as shown in Figure 18, the through holes 123E, 123F (first hole portion) and the through holes 123G, 123H (second hole portion) of the first flange member 122 are aligned with the positions of the holes 68E, 68F, 68G, 68H (Figure 16), respectively. When the first flange member 122 is fixed to the main body 1A in this manner, as shown in Fig. 18 and Fig. 24, the recesses 125L and 125K (third recesses) are disposed in front of the through holes 123E and 123F (first hole portions), and the recesses 125N and 125M (fourth recesses) are disposed in front of the through holes 123G and 123H (second hole portions). At this time, as shown in Fig. 18, when the relay pipe 120 and the main body 1A are viewed from the front, the positional relationship is such that the entire through holes 123E and 123F (first hole portions) and 123G and 123H (second hole portions) are not hidden by the second flange member 124. Specifically, as shown in Fig. 24, the through holes 123E and 123F are located on virtual lines inclined by θ1° (where 0<θ1<90°) with respect to the first reference direction B1. 22 and 24, the recesses 125L and 125K are also located on the respective imaginary lines inclined by θ1° with respect to the first reference direction B1. The through holes 123G and 123H are also located on the respective imaginary lines inclined by θ2° (where 0<θ2<90°) with respect to the first reference direction B1. The recesses 125N and 125M are also located on the respective imaginary lines inclined by θ2° with respect to the first reference direction B1. In this case, the through holes 123E and 123F (first hole portion) and 123G and 123H (second hole portion) are holes into which the fastening member 180 (FIG. 9) fixed to the flat portion 64 of the main body 1A is inserted. Specifically, as shown in FIG. 19, the through holes 123E, 123F arranged above the central axis C2 are arranged in front of the holes 68E, 68F, respectively, and the fastening member 180 is inserted into the through hole 123E and the hole 68E to fix them, and the fastening member 180 is inserted into the through hole 123F and the hole 68F to fix them. Also, the through holes 123G, 123H arranged below the central axis C2 are arranged in front of the holes 68G, 68H, respectively, and the fastening member 180 is inserted into the through hole 123G and the hole 68G to fix them, and the fastening member 180 is inserted into the through hole 123H and the hole 68H to fix them. In this case, the first flange member 122 is arranged in a configuration that blocks the holes 68A, 68B, 68C, 68D (second fastening hole portion).

When the first flange member 122 is fixed to the flat portion 64, the second flange member 124 is fixed to the exhaust adapter 130. In this case, some of the holes (through holes 125A, 125B, 125C, 125D different from the third hole portion and the fourth hole portion in the example of Figures 18 to 20) formed in the second flange member 124 are used as holes into which fastening members 192 fixed to the exhaust adapter 130 are inserted. The fastening members 192 are connecting members such as screws and bolts. The through holes 125A, 125B, 125C, 125D of the second flange member 124 are aligned with the positions of the holes 144A, 144B, 144C, 144D (see Figure 28) formed in the fixed portion 144. In this state, as shown in Figures 19 and 20, each fastening member 192 is inserted into the corresponding two holes, and the holes are fixed to each other. In this case, as shown in FIG. 1, the exhaust adapter 130 is attached in an arrangement that extends in the left-right direction (a direction that intersects with the direction of the central axis C2 (predetermined direction) and the up-down direction).

On the other hand, when the second flange member 124 is fixed to the flat surface portion 64 and the first flange member 122 is fixed to the exhaust portion 140, the fixing structure is modified so that the second flange member 124 is arranged in the arrangement of the first flange member 122 in FIG. 19, etc., and the first flange member 122 is arranged in the arrangement of the second flange member 124 in FIG. 19, etc. Since the second flange member 124 has the same shape as the first flange member 122 when turned upside down, the mounting structure when the first flange member 122 is fixed to the flat surface portion 64 and the mounting structure when the second flange member 124 is fixed to the flat surface portion 64 are the same.

When the second flange member 124 is fixed to the flat portion 64 and the first flange member 122 is fixed to the exhaust portion 140, the second reference direction B2 is the up-down direction. Then, the through holes 125E, 125F (third hole portion) and the through holes 125G, 125H (second hole portion) of the second flange member 124 are aligned with the positions of the holes 68E, 68F, 68G, 68H (FIG. 16). As shown in FIG. 24, when viewed in the direction of the central axis C2, the recesses 123L, 123K, 123N, 123M are arranged on one side of the central axis direction of each of the through holes 125E, 125F, 125G, 125H, and each of the through holes 125E, 125F, 125G, 125H is in a positional relationship that does not overlap with the first flange member 122 in the direction of the central axis C2. Therefore, when the second flange member 124 is fixed to the main body 1A, the recesses 123L, 123K (first recesses) are disposed in front of the through holes 125E, 125F (third hole portions), and the recesses 123N, 123M (second recesses) are disposed in front of the through holes 125G, 125H (fourth hole portions). At this time, when the relay pipe 120 and the main body 1A are viewed from the front, the positional relationship is such that the entire through holes 125E, 125F (third hole portions) and 125G, 125H (fourth hole portions) are not entirely hidden by the first flange member 122. Therefore, even when the fastening members are inserted into the through holes 125E, 125F and the through holes 125G, 125H and fixed to the positions of the holes 68E, 68F, 68G, 68H (FIG. 16), the fastening members can be inserted in a manner that is less likely to be interfered with by the first flange member 122, making the insertion work easier. The second flange portion 124 is similar, and the through holes 125E, 125F are located on virtual lines inclined by θ1° (where 0<θ1<90°) with respect to the second reference direction B2. The other recesses 123L, 123K are also located on virtual lines inclined by θ1° with respect to the first reference direction B1. The through holes 125G, 125H are located on virtual lines inclined by θ2° (where 0<θ2<90°) with respect to the second reference direction B2. The corresponding recesses 123N, 123M are also located on each imaginary line inclined by θ2° with respect to the second reference direction B2. In this case, the through holes 125E, 125F (third hole portion) and 125G, 125H (fourth hole portion) are holes into which fastening members are inserted to be fixed to the flat surface portion 64 of the main body portion 1A. Specifically, the through holes 125E, 125F arranged above the central axis C2 are arranged in front of the holes 68E, 68F, respectively, and fastening members are inserted into the through hole 125E and the hole portion 68E to fix them, and fastening members are inserted into the through hole 125F and the hole portion 68F to fix them. In addition, through holes 125G, 125H arranged below central axis C2 are arranged in front of holes 68G, 68H, respectively, and fastening members are inserted into through hole 125G and hole 68G to fix them, and fastening members are inserted into through hole 125H and hole 68H to fix them. In this case, second flange member 124 is arranged in a configuration that blocks holes 68A, 68B, 68C, 68D (second fastening hole portions).

When the second flange member 124 is fixed to the flat portion 64, the first flange member 122 is fixed to the exhaust adapter 130. In this case, some of the holes (through holes 123A, 123B, 123C, 123D different from the first hole and the second hole) formed in the first flange member 122 are used as holes into which fastening members fixed to the exhaust adapter 130 are inserted. The through holes 123A, 123B, 123C, 123D of the first flange member 122 are aligned with the positions of the holes 144A, 144B, 144C, 144D (see FIG. 28) formed in the fixed portion 144. In this state, each fastening member is inserted into the corresponding two holes, and the holes are fixed to each other. In this case, as in FIG. 1, the exhaust adapter 130 is attached in an arrangement extending in the left-right direction (a direction intersecting the direction of the central axis C2 (a predetermined direction) and the up-down direction).

When the exhaust section 140 is fixed directly to the flat section 64 as shown in Figures 27 and 28, the holes 145A, 145B, 145C, and 145D (see Figure 20) formed in the fixed section 144 are aligned with the positions of the holes 68A, 68B, 68C, and 68D (Figure 16) formed in the flat section 64. In this state, as shown in Figures 27 and 28, each fastening member 190 is inserted into the two corresponding holes, and the holes are fixed together.

The exhaust adapter 130 comprises an exhaust section 140 and a cover body 160. The exhaust section 140 comprises an exhaust tube 142 and a fixed section 144. When the exhaust adapter 130 is directly fixed to the flat section 64 as shown in Figures 25 to 28, the fixed section 144 is stacked on the front and rear of the flat section 64, and the fastening member 190 is inserted into the hole 68 (specifically, holes 68A, 68B, 68C, 68D) from the front side of the fixed section 144 and the flat section 64 so as to fix the fixed section 144 and the flat section 64 together. When the exhaust adapter 130 is fixed to the flat portion 64 via the relay pipe 120 as shown in Figures 1 to 8, the fastening member 192 is inserted from the front side of the fixed portion 144 and the second flange member 124 so as to fasten the fixed portion 144 and the flange member 123 together, with the fixed portion 144 overlapping the front and rear of the second flange member 124.

The exhaust tube 142 is configured in a rectangular tube shape and extends in a predetermined direction (longitudinal direction), with an open section 143 provided at its rear end. The longitudinal direction of the exhaust tube 142 is the direction in which exhaust gas flows in the exhaust tube 142. In the example of Figures 19 and 20, the exhaust section 140 is attached so that the longitudinal direction of the exhaust tube 142 is the left-right direction. The exhaust tube 142 has an upper wall section 142A, a lower wall section 142B, a front wall section 142C, a rear wall section 142D, and a side wall section 142E. These upper wall section 142A, lower wall section 142B, front wall section 142C, rear wall section 142D, and side wall section 142E are integrally connected. The upper wall section 142A and the lower wall section 142B are arranged opposite each other vertically, and are arranged to extend in the left-right direction in the attached state as shown in Figures 19, 20, and 28. The front wall 142C and the rear wall 143D are arranged facing each other in the front and rear directions, and are arranged to extend in the left and right direction in the installation state as shown in Figures 19, 20, and 28. The upper wall 142A, the lower wall 142B, the front wall 142C, and the rear wall 142D surround the top and bottom and the front and rear of the space through which the exhaust gas flows, forming a flow path in the left and right direction. The side wall 142E is arranged at an end on one side in the left and right direction in the exhaust tube 142, and blocks the flow of the exhaust gas to one side in the left and right direction. An exhaust port 148 is provided at an end (the end on the other side in the left and right direction) of the exhaust tube 142 opposite to the side wall 142E. The exhaust port 148 has at least a part open, and functions as an opening that discharges the exhaust gas that flows in the left and right direction inside the exhaust tube 142 to the other side in the left and right direction. An open portion 143 is formed near the end on one side in the left and right direction in the rear wall 142D. The opening 143 is a hole formed in the rear wall 142D, and opens up in a manner that penetrates the rear wall 142D from front to rear.

Because of this configuration, in the configuration shown in Figures 19 and 20, exhaust gas that flows forward so as to pass through the relay pipe 120 enters the exhaust stack 142 from the open portion 143, and this exhaust gas flows left and right inside the exhaust stack 142 and is discharged from the exhaust port 148. In the configuration shown in Figures 27 and 28, exhaust gas that flows forward so as to pass through the exhaust top 40 enters the exhaust stack 142 from the open portion 143, and this exhaust gas flows left and right inside the exhaust stack 142 and is discharged from the exhaust port 148.

The fixed part 144 is integrally connected to the exhaust tube 142 and is configured to protrude outward from the rear end of the exhaust tube 142. The fixed part 144 is provided with a first protruding part 144W that protrudes to one side in the short direction (upper side) at one end of the short direction of the exhaust tube 142. The fixed part 144 is provided with a second protruding part 144X that protrudes to the other side in the short direction (lower side) at the other end of the short direction of the exhaust tube 142. The fixed part 144 is provided with a third protruding part 144Y and a fourth protruding part 144Z that protrude to one side in the long direction and the other side in the long direction at both ends of the long direction of the exhaust tube 142, respectively. Holes 144A, 144B, 144C, 144D, and holes 145A, 145B, 145C, 145D (FIGS. 20 and 28) are formed penetrating the first overhanging portion 144W, the second overhanging portion 144X, the third overhanging portion 144Y, and the fourth overhanging portion 144Z.

As shown in FIG. 19, FIG. 20, or FIG. 28, the exhaust adapter 130 is designed so that the cover body 160 can be attached to the exhaust section 140 after the fixed section 144 is attached to the fixed object. Specifically, the cover body 160 is positioned so as to cover the exhaust tube 142 and the fixed section 144, and the cover body 160 and the exhaust section 140 are fixed together by the screw member 198 (FIG. 4, FIG. 25).

(Example of effects)
The relay pipe 120 for the water heater is configured so that the first flange member 122 can be fixed to the main body 1A, and the second flange member 124 can be fixed to the main body 1A. Therefore, this relay pipe 120 is easy to improve workability. Moreover, when either flange is attached to the main body 1A, the recess (recess recessed toward the central axis) of the other flange is located in front of the "hole for inserting a fastening member to be fixed to the main body 1A" formed in that flange, so that the fastening member can be easily inserted.

The relay pipe 120 can be fixed by inserting fastening members into holes on both the top and bottom of the flange parts, whether the first flange member 122 is fixed to the main body part 1A or the second flange member 124 is fixed to the main body part 1A. Therefore, in a configuration in which both flange parts can be fixed, the upper and lower parts can be stably fixed in either case.

In the relay pipe 120, the shape of the second flange member 124 is an inverted shape of the first flange member 122. In this way, the relay pipe 120 has a common shape for the first flange portion and the second flange member 124, which simplifies manufacturing and management.

The relay pipe 120 can be applied to a water heater that can select between a method of fixing the exhaust adapter 130 via the relay pipe 120 and a method of fixing the exhaust adapter 130 without using the relay pipe 120. Moreover, when the method of fixing the exhaust adapter 130 via the relay pipe 120 is adopted, the hole (second hole) used in the method of fixing the exhaust adapter 130 directly without using the relay pipe 120 can be blocked. Therefore, while realizing a configuration that allows the selection of which of the first flange member 122 and the second flange member 124 to be fixed to the main body 1A, and a configuration that allows the selection of a method of directly fixing the exhaust adapter 130 and a method of indirectly fixing the exhaust adapter 130, when attaching the relay pipe 120, leakage of exhaust gas and the like through the second hole can be suppressed regardless of which flange portion is fixed.

<Other embodiments>
The present disclosure is not limited to the embodiments described above and in the drawings. For example, the features of the above or later described embodiments can be combined in any combination within a range that does not contradict. In addition, any feature of the above or later described embodiments can be omitted unless it is clearly stated as essential. Furthermore, the above-mentioned embodiment may be modified as follows.

In the above embodiment, multiple holes 68 for inserting the fastening member 190 are provided, but there may be only one such hole, or multiple holes with a number different from that of the above embodiment.

It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is intended to include all modifications within the scope of the claims or within the scope equivalent to the claims.

1...Water heater 1A...Main body 33...Front panel 62...Protruding portion 64...Flat surface portion 66...Exhaust port 68...Hole portions 68A, 68B, 68C, 68D...Hole portion (second fastening hole portion)
68E, 68F, 68G, 68H...holes (first fastening hole portions)
120: relay pipe 122: first flange member 123E, 123F: hole portion (first hole portion)
123G, 123H...hole (second hole)
123K, 123L...recess (first recess)
123M, 123N...recesses (second recesses)
124: second flange member 125E, 125F: hole (third hole)
125G, 125H...hole (second hole)
125L, 125K...recess (third recess)
125M, 125N...recess (fourth recess)
126: Cylinder portion 130: Exhaust adapter 180, 190, 192: Fastening member

Claims (4)

A relay pipe that is attached between a main body of a water heater and an exhaust adapter,
A cylindrical portion configured in a cylindrical shape centered on a central axis in a predetermined direction;
a first flange member extending from one end of the cylindrical portion;
a second flange member extending from the other end of the cylindrical portion;
Equipped with
the first flange member has a first hole portion disposed on one side of the central axis in a first reference direction perpendicular to the central axis , a second hole portion disposed on the other side of the central axis in the first reference direction, and a first recess and a second recess recessed toward the central axis at an outer edge of the first flange member,
the second flange member has a third hole portion disposed on one side of the central axis in a second reference direction perpendicular to the central axis , a fourth hole portion disposed on the other side of the central axis in the second reference direction, and a third recess and a fourth recess recessed toward the central axis at an outer edge of the second flange member,
when the first flange member is fixed to the main body portion, the third recess is disposed in front of the first hole portion, the fourth recess is disposed in front of the second hole portion, and the first hole portion and the second hole portion serve as holes into which a fastening member to be fixed to the main body portion is inserted,
When the second flange member is fixed to the main body portion, the first recess is positioned in front of the third hole portion, the second recess is positioned in front of the fourth hole portion, and the third hole portion and the fourth hole portion serve as holes for inserting a fastening member fixed to the main body portion.A relay pipe for a water heater. When the first flange member is fixed to the main body portion, the first reference direction is a vertical direction,
When the second flange member is fixed to the main body portion, the second reference direction is a vertical direction,
The relay pipe for a water heater according to claim 1 , wherein the exhaust adapter is attached in an arrangement extending in a direction intersecting the predetermined direction and the up-down direction. The relay pipe for a water heater according to claim 1 or 2, wherein the second flange member has a shape obtained by turning the first flange member upside down. The main body has a housing that houses a heat exchanger,
the water heater is attached to a front panel that is a front wall portion constituting a front portion of the housing, and has a protruding portion that protrudes forward beyond the front panel,
A flat surface is provided on the front surface of the protruding portion,
The flat surface portion is formed with a circular exhaust port and a plurality of holes provided around the exhaust port,
the plurality of holes include first fastening hole portions to which fastening members inserted into the first flange member or the second flange member are fixed when the first flange member or the second flange member is fixed to the flat portion, and second fastening hole portions to which fastening members inserted into the exhaust adapter are fixed when the exhaust adapter is directly fixed to the flat portion,
The relay pipe for a water heater according to any one of claims 1 to 3, wherein when either the first flange member or the second flange member is fixed to the planar portion, the either flange member is arranged in a configuration that blocks the second fastening hole portion.

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