JP7752863B2 - water heater - Google Patents

Description

The present invention relates to a water heater.

The water heater is equipped with a combustion device (see, for example, Patent Document 1). The combustion device includes an inner case, a support member, and multiple burner units. The inner case is box-shaped with an open front. The support member is fixed to the inner surface of the rear wall of the inner case by spot welding or the like. The multiple burner units are attached to the support member with their thickness direction aligned left-to-right, and are supported within the inner case in a state where they are arranged side-by-side left-to-right.

Japanese Patent Application Laid-Open No. 2020-67218

When repairing, cleaning, or inspecting the combustion device, it is necessary to remove multiple burner units from the inner case. However, because the support member is fixed to the inner surface of the rear wall of the inner case, it is not possible to remove the multiple burner units from the inner case while maintaining their side-by-side arrangement.

The object of the present invention is to provide a water heater in which multiple burner units can be removed as a single unit.

The water heater of claim 1 is provided with an inner case having a rear wall and a pair of side walls extending forward from both left and right ends of the rear wall, the inner case being open at the front, a plurality of burner units having a gas inlet at the front and arranged side by side in the left-right direction with their thickness direction being in the left-right direction, a support member that supports the plurality of arranged burner units within the inner case, and a closing member that closes the front side of the inner case, the support member being arranged below the plurality of burner units and configured to block air flowing from below. The burner unit is provided with a lower plate portion having a plurality of holes for passing upward, and a rear plate portion, a right plate portion, a left plate portion, and a front plate portion which are erected at the rear end, both left and right ends, and the front end of the lower plate portion, respectively, and which surround and support each of the burner units from the rear, right, left, and front, the right plate portion and the left plate portion being integrally extended forward from both left and right ends of the rear plate portion, and right and left fastening portions are provided at the lower ends of the right plate portion and the left plate portion, respectively, which overlap with the upper surface of the lower plate portion and are screwed to the lower plate portion, and the right plate portion and the left plate portion are The front end of the lower plate is provided with front fastening portions that extend inward in the left-right direction, overlap with both left and right end portions of the front plate from the rear, and are screwed to the front plate. The rear end of the lower plate is provided with a rear extending plate portion that extends downward, and the rear extending plate portion is provided with a rear fastening portion that is screwed to the inner surface of the rear wall portion of the inner case . The inner surfaces of each of the pair of side walls are provided with left and right bulging portions that bulge inwardly of the inner case and extend in the front-rear direction. The left and right end portions of the lower plate are provided with left and right bulging portions that extend downward. An extended plate portion is provided, the lower ends of the left and right extended plate portions abut against the upper parts of the left and right bulge portions, the rear stop portions are provided in multiple locations spaced apart in the left-right direction and are formed to extend further downward than the rear extended plate portion, and on the inner surface of the rear wall portion of the inner case, between adjacent rear stop portions spaced apart in the left-right direction, rear bulge portions are provided that bulge inward of the inner case and extend in the left-right direction, and the lower ends of the rear extended plate portions abut against the upper parts of the rear bulge portions .

The left and right bulging portions of the water heater of claim 2 may bulge toward the inside of the inner case and have a flat portion at the top facing upward, and the lower ends of the left and right extending plate portions may abut against the flat portion.

The rear stop portion of the water heater of claim 3 is provided at least in three locations on the right end side, center, and left end side of the lower end of the rear extension plate portion, and the rear bulge portion may be divided into left and right parts at the rear stop portion in the center.

In the water heater according to claim 4, the height positions of the left and right bulging portions from the lower ends of the pair of side walls may be higher than the height position of the rear bulging portion from the lower end of the rear wall portion.

In the water heater according to claim 5 , the rear bulging portion may bulge toward the inside of the inner case and have a dome-shaped cross section perpendicular to the longitudinal direction.

A straightening member is fixed to the underside of the lower plate of the water heater of claim 6 , covering the underside from below and straightening the air flowing from below toward the upper side, the straightening member having a front wall, a right wall, a left wall, a rear wall, and a bottom wall with a plurality of holes, and formed in a box shape with an open top, the upper end of the front wall is provided with a hook piece that protrudes forward, and the upper ends of the right wall and the left wall are provided with a pair of left and right fixing pieces, the straightening member rotates toward the underside of the lower plate around the hook piece with the hook piece hooked from below into locking holes provided at the front end of the lower plate, and the pair of left and right fixing pieces overlapping on the underside of the lower plate are fixed to the underside of the lower plate by being screwed together with the right and left fastening parts to the lower plate.

In the water heater according to claim 7 , the rear extending plate portion may overlap an inner surface of the rear wall portion of the inner case.
The water heater of claim 8 is provided with a combustion device including an inner case having a rear wall portion and a pair of side walls extending forward from both left and right ends of the rear wall portion, the inner case being open at the front side, a plurality of burner units having a gas inlet at the front side and arranged side by side in the left and right direction with their thickness direction being in the left and right direction, a support member that supports the plurality of arranged side by side burner units within the inner case, and a closing member that closes the front side of the inner case, the support member being arranged below the plurality of burner units and allowing air flowing from below to pass upward. and a rear plate portion, a right plate portion, a left plate portion, and a front plate portion that are erected at the rear end, both left and right ends, and the front end of the lower plate portion, respectively, and surround and support each of the burner units from the rear, right, left, and front, the right plate portion and the left plate portion are integrally extended forward from both left and right ends of the rear plate portion, and right and left fastening portions are provided at the lower ends of each of the right plate portion and the left plate portion, overlapping with the upper surface of the lower plate portion and being screwed to the lower plate portion, and at the front ends of each of the right plate portion and the left plate portion, A front stopper is provided on each of the left and right end portions of the plate portion from the rear and is screwed to the front plate portion, a rear extending plate portion is provided at the rear end portion of the lower plate portion and a rear stopper is provided on the rear extending plate portion and is screwed to the inner surface of the rear wall portion of the inner case, and a rectifying member is fixed to the lower surface of the lower plate portion so as to cover the lower surface from below and to rectify the air flowing from below toward the upper side, the rectifying member has a front wall, a right wall, a left wall, a rear wall, and a bottom wall having a plurality of holes, and is formed in a box shape with an open top, A hook piece that protrudes forward is provided at the upper end of the front wall, and a pair of left and right fixed pieces are provided at the upper ends of each of the right and left walls, and the straightening member rotates toward the underside of the lower plate portion around the hook piece with the hook piece hooked from below into a locking hole provided at the front end of the lower plate portion, and the pair of left and right fixed pieces that are superimposed on the underside of the lower plate portion are fixed to the underside of the lower plate portion by being screwed together with the right and left fastening portions to the lower plate portion.

According to the water heater of claim 1, the bottom plate, rear plate, right plate, left plate, and front plate that make up the support member are fastened together with screws. By releasing the screws on the rear fasteners, an operator can easily pull out the multiple burner units, which remain in a side-by-side arrangement, from inside the inner case together with the support member. This improves the maintainability of the water heater.

Furthermore, since the support member and the multiple burner units are supported within the inner case with the left and right extension plate portions abutting the upper portions of the left and right bulges, the support member and the multiple burner units can be temporarily supported within the inner case even when the screw fastening of the rear stopper is released. This prevents the support member and the multiple burner units from falling when the screw fastening of the rear stopper is released. Furthermore, the lower end of the rear extension plate portion abutting the upper portion of the rear bulge portion can determine the height position of the rear end of the lower plate portion. This allows the rear stopper to be screwed to the inner surface of the rear plate portion of the inner case with the height position of the rear end of the lower plate portion determined to be the correct position.

According to the water heater of claim 2 , the left and right bulging portions have flat portions at their upper parts, so that the lower ends of the left and right extending plate portions can be stably supported from below. In addition, because the flat portions extend in the front-rear direction, the left and right extending plate portions can be stably guided in the front-rear direction.

According to the water heater of claim 3 , the rear stopper is provided not only on the left and right but also in the center, so that the center portion of the lower end of the rear extension plate can be fixed to the inner surface of the rear wall, thereby preventing the center portion of the lower end of the rear extension plate from floating relative to the inner surface of the rear wall.

According to the water heater of claim 4 , the height positions of the left and right bulges are higher than the height position of the rear bulge. This allows the left and right bulges with special shapes having flat portions to be formed by drawing sheet metal at positions above the lower ends of the side walls. This prevents distortion of the water heater due to drawing at the lower ends of the side walls.

According to the water heater of claim 5 , the bulge portion has a dome-shaped cross section perpendicular to the longitudinal direction, so when the support member supporting multiple burner units is stored from the front side of the inner case, even if the lower end of the rear extension plate portion shifts downward below the upper part of the rear bulge portion and makes contact with it, it is guided upward along the dome-shaped surface, so that the lower end of the rear extension plate portion can be properly positioned at the upper part of the rear bulge portion.

According to the water heater of claim 6 , the straightening member is fixed to the underside of the lower plate, which facilitates air flow toward the lower plate. As a result, combustion air can be efficiently supplied toward the multiple burner units through the multiple holes in the lower plate. Furthermore, the pair of left and right fastening pieces of the straightening member can be fastened together with the right and left fastening portions to the lower plate with screws. This allows the straightening member to be fastened using only screws without the need for cumbersome fastening methods such as welding, making it possible to assemble the combustion device only in a workshop that specializes in screw fastening. Furthermore, because the right and left fastening portions are fastened together with the screws that secure them, the number of screws used for fastening can be reduced, and the labor required for screw fastening can be reduced.

According to the water heater of claim 7 , the rear extension plate portion overlaps and adheres tightly to the inner surface of the rear wall portion of the inner case, thereby preventing air flowing into the space below the lower plate portion of the inner case from flowing toward the burner unit through the gap between the inner surface of the rear wall portion of the inner case and the rear plate portion of the support member.
According to the water heater of claim 8, the straightening member is fixed to the underside of the lower plate, which facilitates air flow toward the lower plate. As a result, combustion air can be efficiently supplied toward the multiple burner units through the multiple holes in the lower plate. Furthermore, the pair of left and right fixing pieces of the straightening member can be fastened together with the right and left fastening portions to the lower plate with screws. This allows the straightening member to be fastened using only screws without the need for complicated fastening methods such as welding, making it possible to assemble the combustion device only in a workshop that specializes in screw fastening. Furthermore, because the right and left fastening portions are fastened together with the screws that secure them, the number of screws used for fastening can be reduced, and the labor required for screw fastening can be reduced.

FIG. 2 is a front view of the water heater 1. FIG. 2 is a perspective view of the combustion device 4. FIG. 2 is a perspective view of the combustion device 4 with the front wall removed. FIG. 2 is an exploded perspective view of the combustion device 4. FIG. 5 is an exploded perspective view of the combustion device 4 as seen from a different angle from that of FIG. 4 . 2 is an exploded perspective view of a support plate 23, a lower plate portion 24, and a straightening member 80. FIG. 1 is a perspective view of a state in which a burner assembly 10 is arranged on the front side of a case body 21. FIG. 1 is a perspective view of a burner assembly 10 inserted partway into a case body 21. FIG. 1 is a perspective view of a state in which a burner assembly 10 is fixed in a case body 21. FIG.

The following describes an embodiment of the present invention. Unless otherwise specified, the device configurations described below are not intended to be limiting and are merely illustrative examples. The drawings are used to explain the technical features that may be adopted by the present invention. In the following description, arrows in the drawings will be used to indicate left and right, front and back, and up and down.

The configuration of water heater 1 will be described with reference to Figure 1. Water heater 1 is a latent heat recovery gas water heater. Water heater 1 includes a fan 3, a combustion device 4, a primary heat exchanger 5, and a secondary heat exchanger 6 within a housing 2.

The combustion device 4 includes an inner case 20. The inner case 20 is a rectangular box with an open top (see Figure 2). A burner group 25 is housed within the inner case 20. The burner group 25 is made up of multiple burner units 60 and is supported within the inner case 20 by support members 22 (see Figure 4), which will be described later. The fan 3 is fixed to the underside of the bottom wall portion 34 (see Figure 2) of the inner case 20 and supplies combustion air into the inner case 20.

A gas supply unit 8 is fixed to the front of the inner case 20 and distributes gas to multiple burner units 60 inside the inner case 20. Inside the inner case 20, the multiple burner units 60 burn a mixture of gas and air, generating combustion exhaust. The specific structure of the combustion device 4 will be described later.

The primary heat exchanger 5 is located above the combustion device 4. The combustion exhaust gas passes upward through the primary heat exchanger 5. The primary heat exchanger 5 exchanges heat between the combustion exhaust gas and water flowing inside a heat transfer tube 5A, recovering sensible heat from the combustion exhaust gas. The secondary heat exchanger 6 is located above the primary heat exchanger 5. The combustion exhaust gas that has passed through the primary heat exchanger 5 passes upward through the secondary heat exchanger 6. The secondary heat exchanger 6 exchanges heat between the combustion exhaust gas and water flowing inside a heat transfer tube (not shown), recovering latent heat from the combustion exhaust gas.

An exhaust pipe 7 is provided on the top surface of the housing 2. The exhaust pipe 7 protrudes upward from the top surface of the housing 2 and discharges the combustion exhaust gas that has passed through the secondary heat exchanger 6 to the outside of the housing 2. A gas inlet 11, a water inlet 12, and a hot water outlet 13 are provided on the bottom surface of the housing 2. A 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.

Inside the housing 2, the gas inlet 11 is connected to the gas supply unit 8 via a gas pipe 19. The gas pipe 19 is equipped with a main valve, a proportional valve, etc. (not shown). The water inlet 12 is connected to the water supply section 14. The water supply section 14 is connected to the inlet of the secondary heat exchanger 6 via a water supply pipe 15. The outlet of the secondary heat exchanger 6 is connected to the inlet of the primary heat exchanger 5 via a relay pipe 17. The outlet of the primary heat exchanger 5 is connected to the hot water outlet 13 via a hot water outlet pipe 18. Bypass pipes 16A and 16B are connected between the water supply section 14 and the hot water outlet pipe 18. The bypass pipes 16A and 16B allow a portion of the water supplied from the water supply section 14 to join the hot water flowing through the hot water outlet pipe 18 without passing through the primary heat exchanger 5 and secondary heat exchanger 6.

The configuration of the combustion device 4 will be described with reference to Figures 2 to 5. As shown in Figure 2, the combustion device 4 comprises an inner case 20 and a burner assembly 10. The inner case 20 comprises a case body 21 and a front wall 28. The case body 21 is a square box-like structure with an open top and front. The front wall 28 is a rectangle that is long in the left-right direction when viewed from the front. The front wall 28 is fixed to close the upper front side of the case body 21. The burner assembly 10 is a unit that integrally supports the burner group 25 (see Figure 6). The burner assembly 10 is inserted into the case body 21 from the front and screwed in place (see Figure 3).

The structure of the case body 21 will now be described. As shown in Figures 4 and 5, the case body 21 comprises a right wall portion 31, a left wall portion 32, a rear wall portion 33, and a bottom wall portion 34 (see Figures 2 and 3, omitted in Figures 4 and 5). The right wall portion 31 and the left wall portion 32 extend forward from both the left and right ends of the rear wall portion 33. Therefore, the right wall portion 31, the left wall portion 32, and the rear wall portion 33 are integrally formed. Fixing pieces 311, 321 (see Figure 3) are bent outward at the front ends of the right wall portion 31 and the left wall portion 32, respectively. The front wall 28 (see Figure 2) and the gas supply unit 8 are screwed to the fixing pieces 311, 321 (see Figures 1 and 2).

As shown in Figures 2 and 3, the bottom wall 34 is fixed so as to close the open lower part of the case body 21 from below. An air chamber 101 is formed between the bottom wall 34 and the bottom surface of the burner assembly 10 (the lower surface of the lower plate 24, described below). An opening (not shown) is provided in the left rear part of the lower surface of the bottom wall 34. The fan 3 is fixed so as to cover this opening from below (see Figure 1). Combustion air blown by the fan 3 flows into the air chamber 101 through the opening.

A right bulge 35 is provided on the inner surface of the right wall 31, slightly above the lower end. The right bulge 35 extends approximately horizontally in the front-to-rear direction. The right bulge 35 bulges inward (to the left) in the left-to-right direction, and its cross section perpendicular to the longitudinal direction is approximately triangular. A flat surface 351 is provided on the upper surface of the right bulge 35. The flat surface 351 has an elongated rectangular shape extending in the front-to-rear direction in a plan view. A left bulge 36 is provided on the inner surface of the left wall 32, slightly above the lower end, at the same height as the right bulge 35. The left bulge 36 has a symmetrical shape to the right bulge 35. A flat surface 361 is also provided on the upper surface of the left bulge 36. The right bulge 35 and left bulge 36 are formed by press-molding sheet metal.

An overheating prevention plate 39 is attached to the inner surface of the rear wall 33. The overheating prevention plate 39 is attached so as to cover the upper portion of the inner surface of the rear wall 33 with a gap between them. A recess 335 protrudes rearward below the overheating prevention plate 39. The recess 335 is rectangular and elongated in the left-right direction when viewed from the front. A first rear bulge 37 and a second rear bulge 38 are provided in the left-right direction on the inner surface of the rear wall 33, slightly above the lower end. The first rear bulge 37 is provided on the right side of the inner surface of the rear wall 33, slightly above the lower end, and extends in the left-right direction when viewed from the front. The first rear bulge 37 bulges inward (toward the front), and its cross section perpendicular to the longitudinal direction is generally dome-shaped, bulging forward in a generally arc-like shape. The second rear bulge 38 is provided on the left side of the inner surface of the rear wall 33, at the same height as the first rear bulge 37. The second rear bulge 38 has the same shape as the first rear bulge 37.

A predetermined gap is formed between the left end of the first rear bulge portion 37 and the right end of the second rear bulge portion 38. This predetermined gap refers to a gap long enough to accommodate the rear stopper portion 56 (described below) of the burner assembly 10. The first rear bulge portion 37 and the second rear bulge portion 38 are also formed by press-molding sheet metal. A fixing hole 331 is provided on the right side of the right end of the first rear bulge portion 37. A fixing hole 332 is provided between the left end of the first rear bulge portion 37 and the right end of the second rear bulge portion 38. A fixing hole 333 is provided on the left side of the left end of the second rear bulge portion 38. Fixing holes 331 to 333 are located at the same height and penetrate the rear wall portion 33 in the front-to-rear direction.

As described above, the right bulge portion 35, the left bulge portion 36, the first rear bulge portion 37, and the second rear bulge portion 38 are formed by press-molding sheet metal. The first rear bulge portion 37 and the second rear bulge portion 38 have a typical bulge shape with a generally dome-shaped cross section perpendicular to the longitudinal direction. In contrast, the right bulge portion 35 and the left bulge portion 36 have a generally triangular cross section perpendicular to the longitudinal direction, and therefore have a unique bulge shape different from the first rear bulge portion 37 and the second rear bulge portion 38. If such right bulge portion 35 and left bulge portion 36 were to be formed by press molding near the lower ends of the right wall portion 31 and the left wall portion 32, respectively, distortion may occur near the lower ends of the right wall portion 31 and the left wall portion 32, compared to forming a typical generally dome-shaped bulge shape. Therefore, in this embodiment, if the length from the lower end of the rear wall portion 33 to the lower ends of the first rear bulge portion 37 and the second rear bulge portion 38 is defined as H1, and the length from the lower end of each of the right wall portion 31 and the left wall portion 32 to the lower end of each of the right wall portion 31 and the left wall portion 32 is defined as H2, the design is such that H2 is longer than H1. In other words, the height positions of the right bulge portion 35 and the left bulge portion 36 are higher than the height positions of the first rear bulge portion 37 and the second rear bulge portion 38. This allows the specially shaped right bulge portion 35 and the left bulge portion 36 to be formed at a position above the lower ends of the right wall portion 31 and the left wall portion 32, thereby preventing distortion due to press molding at the lower ends of the right wall portion 31 and the left wall portion 32.

The configuration of the burner assembly 10 will be described with reference to Figures 4 to 6. As shown in Figures 4 and 5, the burner assembly 10 comprises a support member 22, a burner group 25, a packing 26, and a front plate portion 27. As shown in Figure 6, the support member 22 comprises a support plate 23, a lower plate portion 24, and a straightening member 80.

The shape of the support plate 23 will now be described. The support plate 23 comprises a rear plate portion 41, a right plate portion 42, and a left plate portion 43, and is formed in a generally U-shape that opens forward in a plan view. The rear plate portion 41 has a horizontally elongated rectangular shape when viewed from the front. A fitting portion 44 protrudes rearward from the center of the rear plate portion 41. The fitting portion 44 has a rectangular shape that is long in the left-right direction when viewed from the front, and fits into the recess 335 of the rear wall portion 33 from the front. A plurality of support pieces 411 are formed at the upper end of the rear plate portion 41, each bent forward at equal intervals in the left-right direction. A plurality of support pieces 412 are also formed at the lower end of the rear plate portion 41, each bent forward at equal intervals in the left-right direction.

The right and left plate portions 42 and 43 have a width sufficient to accommodate the burner group 25, and extend parallel to the right and left wall portions 31 and 32 of the case body 21, inside the right and left wall portions 31 and 32. The right and left plate portions 42 and 43 are bent outward in the middle in the front-to-rear direction to widen the left-to-right spacing, and then bent forward. The front half of the right plate portion 42 abuts against the inner surface of the right plate portion 42. The front half of the left plate portion 43 abuts against the inner surface of the left plate portion 43. The rear half of the right plate portion 42 abuts against the right face of the rightmost burner unit 60 of the burner group 25. The rear half of the left plate portion 43 abuts against the left face of the leftmost burner unit 60 of the burner group 25.

A first right stopper 47 protruding to the right is provided at the lower end of the rear half of the right plate 42. A fixing hole 471 is provided in the first right stopper 47. A second right stopper 48 protruding to the left is provided at the lower end of the front half of the right plate 42. A fixing hole 481 is provided in the second right stopper 48. A first left stopper 49 protruding to the left is provided at the lower end of the rear half of the left plate 43. A fixing hole 491 is provided in the first left stopper 49. A second left stopper 50 protruding to the right is provided at the lower end of the front half of the left plate 43. A fixing hole 511 is provided in the second left stopper 50. A front stopper 45 is bent leftward at the front end of the right plate 42. A front stopper 46 is bent rightward at the front end of the left plate 43.

The shape of the lower plate portion 24 will now be described. The lower plate portion 24 is rectangular and elongated in the left-right direction when viewed from above. A plurality of holes 500 are formed in the lower plate portion 24 at predetermined intervals in the front-to-rear and left-to-right directions. A fixing hole 511 is provided on the rear side of the right end of the lower plate portion 24. A fixing hole 512 is provided on the front side of the right end of the lower plate portion 24. A fixing hole 513 is provided on the rear side of the left end of the lower plate portion 24. A fixing hole 514 is provided on the front side of the left end of the lower plate portion 24. A lower bent piece 51 is provided on the right end of the lower plate portion 24. The lower bent piece 51 protrudes downward. A lower bent piece 52 is provided on the left end of the lower plate portion 24. The lower bent piece 52 protrudes downward. The lower bent pieces 51, 52 are approximately rectangular and elongated in the front-to-rear direction when viewed from the side. A pair of left and right locking holes 541, 542 are provided on the front end side of the lower plate portion 24. The locking holes 541, 542 are spaced apart in the left-right direction and are rectangular in plan view.

As shown in FIG. 5, a rear extension plate portion 53 is provided at the rear end of the lower plate portion 24. The rear extension plate portion 53 protrudes downward from the rear end of the lower plate portion 24 and has a generally rectangular shape that is elongated in the left-right direction when viewed from the front. The rear extension plate portion 53 extends downward further than the lower bent pieces 51 and 52. Rear stop portions 55, 56, and 57 are provided at the right, center, and left ends of the lower end of the rear extension plate portion 53, respectively. The rear stop portions 55, 56, and 57 protrude further downward from the lower end of the rear extension plate portion 53 and have a generally semicircular shape when viewed from the front. Fixing holes 551, 561, and 571 are provided at the center of each of the rear stop portions 55, 56, and 57, respectively.

The shape of the airflow rectifying member 80 will now be described. As shown in Figure 6, the airflow rectifying member 80 includes a bottom wall 81, a right wall 82, a left wall 83, a front wall 84, and a rear wall 85, and is formed in the shape of a shallow box with an open top. The bottom wall 81 is rectangular in shape and is elongated in the left-right direction when viewed from above, and has multiple holes 811 in its center. The front wall 84 has multiple holes 841 aligned in the left-right direction. The rear wall 85 also has multiple holes 851 aligned in the left-right direction. Contact pieces 82A, 83A, 84A, and 85A are bent outward at the upper ends of the right wall 82, left wall 83, front wall 84, and rear wall 85, respectively.

A pair of left and right hook pieces 86, 87 are provided at the front end of the abutment piece 84A of the front wall 84. Hook piece 86 is located on the right side, and hook piece 87 is located on the left side. Hook pieces 86, 87 protrude forward. A fixing piece 88 protruding to the right is provided at the rear of the abutment piece 82A of the right wall 82. A fixing hole 881 is provided in the fixing piece 88. A fixing piece 89 protruding to the left is provided at the rear of the abutment piece 83A of the left wall 83. A fixing hole 891 is provided in the fixing piece 89. The flow straightening member 80 is attached so as to cover the underside of the lower plate portion 24. The method of attaching the flow straightening member 80 will be described later.

Air blown by the fan 3 flows into the air chamber 101 through an opening (not shown) in the lower plate portion 24. The air in the air chamber 101 is rectified upward by multiple holes 811 in the bottom wall 81 of the rectifying member 80. A portion of the air in the air chamber 101 flows into the rectifying member 80 through multiple holes 841 in the front wall 84 and multiple holes 851 in the rear wall 85. The air rectified upward is supplied in a balanced manner to the burner group 25 side through multiple holes 500 in the lower plate portion 24.

The configuration of the burner group 25 will be described. The burner group 25 comprises multiple burner units 60. The burner units 60 are well-known rich/lean burners and comprise a lean side inlet 61, a rich side inlet 62, a mixing section 63, and a flame port section 64. The lean side inlet 61 is a lower opening that opens forward and introduces fuel gas and primary air. The rich side inlet 62 is located directly above the lean side inlet 61 and is an upper opening that introduces fuel gas. The mixing section 63 is located downstream of the lean side inlet 61 and the rich side inlet 62, and its interior is separated by each inlet. The flame port section 64 opens at the upper end of the mixing section 63 and consists of a central lean flame port and rich flame ports on either side of it. The multiple burner units 60 are arranged side by side in the left-right direction with their thickness direction aligned left-right.

The shapes of the packing 26 and the front plate portion 27 will be explained. The packing 26 is formed in a rectangular shape that is elongated in the left-right direction when viewed from the front. The packing 26 has a pair of upper and lower openings 261, 262 arranged side by side in the left-right direction. The openings 261, 262 correspond to the lean side inlet 61 and the rich side inlet 62, respectively. The front plate portion 27 is a metal plate and is formed in a roughly rectangular shape that is elongated horizontally when viewed from the front. The front plate portion 27 has a pair of upper and lower openings 271, 272 arranged side by side in the left-right direction. The openings 271, 272 correspond to the lean side inlet 61 and the rich side inlet 62, respectively, of the burner unit 60. At the upper end of the front plate portion 27, a plurality of support pieces 273 are formed by bending them backward at equal intervals in the left-right direction.

Referring to Figure 6, the method of fixing the support plate 23 and the straightening member 80 to the lower plate portion 24 will be described. First, the support plate 23 is placed on the upper surface of the lower plate portion 24. The first right fastening portion 47, the second right fastening portion 48, the first left fastening portion 49, and the second left fastening portion 50 are overlapped on the upper surface of the lower plate portion 24. Next, the fixing hole 481 of the second right fastening portion 48 is aligned with the fixing hole 512 of the lower plate portion 24 and fastened from above with the screw 72. Furthermore, the fixing hole 511 of the second left fastening portion 50 is aligned with the fixing hole 514 of the lower plate portion 24 and fastened from above with the screw 74. This fixes the front portion of the support plate 23 to the upper surface of the lower plate portion 24. At this time, the fixing hole 471 of the first right fastening portion 47 is positioned over the fixing hole 511 of the lower plate portion 24, and the fixing hole 481 of the first left fastening portion 49 is positioned over the fixing hole 512 of the lower plate portion 24.

Next, the hook pieces 86, 87 of the rectifying member 80 are inserted from below into the locking holes 541, 542 on the front end of the lower plate portion 24 and hooked onto them. In this state, the rectifying member 80 is rotated upward toward the underside of the lower plate portion 24 around the hook pieces 86, 87. The fixing pieces 88, 89 overlap the underside of the lower plate portion 24. The fixing holes 881, 891 of the fixing pieces 88, 89 face the fixing holes 511, 503 of the lower plate portion 24. The fixing hole 471 of the first right stopper 47, the fixing hole 511 of the lower plate portion 24, and the fixing hole 881 of the fixing piece 88 are aligned vertically, so the screw 71 is tightened from above. In other words, the first right stopper 47 and the fixing piece 88 are fastened together with the screw 71 to the top and bottom surfaces of the lower plate portion 24. Furthermore, since the fixing hole 481 of the first left fastening portion 49, the fixing hole 513 of the lower plate portion 24, and the fixing hole 891 of the fixing piece 89 are aligned in the vertical direction, the screw 73 is fastened from above. In other words, the first left fastening portion 49 and the fixing piece 89 are fastened together with the screw 73 to the top and bottom surfaces of the lower plate portion 24.

In this way, the rectifying member 80 can be fixed using only the screws 71 and 73, without using cumbersome fixing methods such as welding. This reduces the number of screws used for fixing and the labor required for screwing. In this way, the support plate 23 is fixed to the upper surface of the lower plate portion 24, and the rectifying member 80 is fixed to the lower surface.

The method for assembling the burner assembly 10 will be described with reference to Figures 4 and 5. First, multiple burner units 60 are arranged in left-right order on the upper surface of the lower plate portion 24 of the support member 22. At this time, the rear end of each burner unit 60 is inserted into and engaged with the slits between adjacent support pieces 411 and between adjacent support pieces 412 in the left-right direction, which are provided on the rear plate portion 41 of the support plate 23. The burner group 25 is sandwiched between the rear half of the right plate portion 42 and the rear half of the left plate portion 43. This positions the burner group 25 on the upper surface of the lower plate portion 24.

Next, the packing 26 is placed from the front side against the front side of the burner group 25. The right end of the rear surface of the front plate 27 is then abutted against the front surface of the front stopper 45 of the right plate 42, and the left end of the rear surface of the front plate 27 is abutted against the front surface of the front stopper 46 of the left plate 43, and secured with four screws 79. At this time, the front end of each burner unit 60 is inserted into and engaged with the slits between adjacent support pieces 273 provided on the upper end of the front plate 27. This secures the front plate 27 to the support plate 23, completing the burner assembly 10 (see Figure 7). The burner assembly 10 supports the burner group 25 from the rear, right, left, and front by the support plate 23 and front plate 27 on the upper surface of the lower plate 24.

With reference to Figures 7 to 9, the method of installing the burner assembly 10 into the case body 21 will be described. As shown in Figure 7, first, place the burner assembly 10 on the front side of the case body 21 and insert it into the case body 21. At this time, the lower end of the lower bent piece 51 of the right plate portion 42 abuts against the flat surface 351 of the right bulge portion 35, and the lower end of the lower bent piece 52 of the left plate portion 43 abuts against the flat surface 361 of the left bulge portion 36. In this state, the burner assembly 10 is pushed rearward. Then, as shown in Figure 8, the lower bent pieces 51 and 52 slide rearward on the flat surfaces 351 and 361. As a result, the burner assembly 10 is guided toward the back of the case body 21 by the flat surfaces 351 and 361. Because the lower bent pieces 51 and 52 are engaged from above with the flat surfaces 351 and 361, the burner assembly 10 will not fall even if you let go of it.

If the right bulge portion 35 and the left bulge portion 36 were to have a general, generally dome-shaped bulge shape similar to the first rear bulge portion 37 and the second rear bulge portion 38, the lower ends of the lower bent piece 51 of the right plate portion 42 and the lower bent piece 52 of the left plate portion 43 would abut against the arc-shaped upper parts of the right bulge portion 35 and the left bulge portion 36, respectively, and the lower bent pieces 51, 52 would not be stably supported from below. Furthermore, because the burner assembly 10 would be guided rearward in an unstable state, if the burner assembly 10 were to tilt, there is a possibility that one of the lower bent pieces 51, 52 would slide off the upper part of the corresponding right bulge portion 35 or left bulge portion 36.

In this embodiment, the right bulge 35 and the left bulge 36 have a special bulge shape with flat surfaces 351, 361 at their upper portions, respectively, which allows the lower end of the lower bent piece 51 of the right plate 42 and the lower end of the lower bent piece 52 of the left plate 43 to be stably supported from below. Furthermore, because the flat surfaces 351, 361 extend in the front-to-rear direction, the lower ends of the lower bent pieces 51, 52 can be stably guided in the front-to-rear direction.

The rear surface of the rear extension plate 53 abuts against the inner surface of the rear wall 33 of the case main body 21. At this time, the mating portion 44 of the rear plate 41 fits into the recess 335 of the rear wall 33. Furthermore, the lower end of the rear extension plate 53 abuts against the upper portions of the first rear bulge 37 and the second rear bulge 38. The rear stopper 55 is located to the right of the right end of the first rear bulge 37. The fixing hole 551 of the rear stopper 55 faces the fixing hole 331 of the rear wall 33. The rear stopper 56 is located between the left end of the first rear bulge 37 and the right end of the second rear bulge 38. The fixing hole 561 of the rear stopper 56 faces the fixing hole 332 of the rear wall 33. The rear stopper 57 is located to the left of the left end of the second rear bulge 38. The fixing hole 571 of the rear stopper 57 faces the fixing hole 333 of the rear wall 33. At this time, the burner assembly 10 is temporarily supported at a predetermined height.

When inserting the burner assembly 10 into the case body 21, the lower end of the rear extension plate portion 53 may come into contact with a lower portion than the upper portions of the first rear bulge portion 37 and the second rear bulge portion 38. As described above, the cross section perpendicular to the longitudinal direction of each of the first rear bulge portion 37 and the second rear bulge portion 38 is dome-shaped, bulging forward in a generally arc-like shape. As a result, as the burner assembly 10 is pushed rearward, the lower end of the rear extension plate portion 53 slides upward along the surfaces of each of the first rear bulge portion 37 and the second rear bulge portion 38. In other words, the lower end of the rear extension plate portion 53 is guided by the upper portions of the first rear bulge portion 37 and the second rear bulge portion 38 and is automatically positioned.

Then, with the burner assembly 10 temporarily supported at a specified height, screws 75 are fastened from the front into fixing holes 551 and 331. Screws 76 are fastened from the front into fixing holes 561 and 332. Screws 77 are fastened from the front into fixing holes 571 and 333. This secures the rear retaining portions 55-57 to the inner surface of the rear wall portion 33 of the case body 21, securing the burner assembly 10 within the case body 21 and completing installation of the burner assembly 10.

As shown in Figure 9, when the burner assembly 10 is fixed within the case body 21, the back surface of the rear extension plate portion 53 overlaps and fits tightly against the inner surface of the rear wall portion 33. The right surface of the lower bent piece 51 and the right surface of the front half of the right plate portion 42 overlap and fit tightly against the inner surface of the right wall portion 31 of the case body 21. The left surface of the lower bent piece 52 and the left surface of the front half of the left plate portion 43 overlap and fit tightly against the inner surface of the left wall portion 32 of the case body 21. This prevents air in the air chamber 101 from leaking along the inner surface of the case body 21 toward the burner group 25.

Furthermore, the combustion device 4 has rear stoppers 55-57 that protrude further downward from the lower end of the rear extension plate 53, so that they are positioned within the air chamber 101 below the lower plate 24. As a result, even if air leaks from the rear stoppers 55-57 where the screws 75-77 are fastened, it will only leak outside the case body 21 and will not flow toward the burner group 25. Therefore, good gas combustion in the burner group 25 is not affected.

Furthermore, if the water heater 1 is long in the left-right direction, the left-right width of the rear extension plate portion 53 will also be long. If the rear stop portion 56 in the center of the rear extension plate portion 53 were not provided, the center portion of the lower end of the rear extension plate portion would be prone to floating relative to the inner surface of the rear wall portion 33 of the case body 21. In the water heater 1 of this embodiment, in addition to rear stop portions 55, 57 on both the left and right sides, a rear stop portion 56 is also provided in the center, so the center portion of the lower end of the rear extension plate portion 53 can be fixed to the inner surface of the rear wall portion 33. This prevents the center portion of the lower end of the rear extension plate portion 53 from floating relative to the inner surface of the rear wall portion 33, ensuring a tight fit.

When removing the burner assembly 10 from the case body 21, in the state shown in Figure 9, insert a tool into the air chamber 101 inside the case body 21 from the front and sequentially remove the screws 75-76 from the three rear stoppers 55-57. As described above, the lower ends of the lower bent pieces 51, 52 abut against the flat surfaces 351, 361 of the right bulge 35 and left bulge 36 inside the case body 21, and the lower end of the rear extension plate 53 abuts against the upper portions of the first rear bulge 37 and second rear bulge 38. Therefore, the burner assembly 10 will not fall even if it is not supported from below with a hand.

Then, as shown in Figures 8 and 7, the burner assembly 10 is pulled out toward the front. The burner assembly 10 is guided forward while being temporarily supported by the right bulge 35 and left bulge 36, so the burner assembly 10 can be easily pulled out. In this way, with the water heater 1 of this embodiment, the parallel-arranged burner group 25 can be attached and detached integrally within the case body 21, improving maintainability.

As described above, the water heater 1 of this embodiment includes a combustion device 4 within the housing 2. The combustion device 4 includes an inner case 20, multiple burner units 60, a support member 22, and a front wall 28. The inner case 20 includes a right wall portion 31, a left wall portion 32, and a rear wall portion 33, and is open at the front. The right wall portion 31 and the left wall portion 32 extend forward from both the left and right ends of the rear wall portion 33. The multiple burner units 60 have a lean side inlet 61 and a rich side inlet 62 at their front sides, and are arranged side by side in the left-right direction with their thickness direction aligned left-right, constituting a burner group 25. The support member 22 supports the burner group 25 within the inner case 20. The front wall 28 closes the front side of the inner case 20.

The support member 22 comprises a lower plate portion 24 and a support plate 23. The lower plate portion 24 is positioned below the burner group 25 and has multiple holes 500 that allow air flowing from below to pass upward. The support plate 23 comprises a rear plate portion 41, a right plate portion 42, a left plate portion 43, and a front plate portion 27. The rear plate portion 41, the right plate portion 42, the left plate portion 43, and the front plate portion 27 are erected at the rear end, both left and right ends, and the front end of the lower plate portion 24, respectively, and surround and support the burner group 25 from the rear, right, left, and front. The right plate portion 42 and the left plate portion 43 are integrally extended forward from both left and right ends of the rear plate portion 41. The lower ends of the right plate portion 42 and the left plate portion 43 are provided with a first right stopper portion 47 and a first left stopper portion 49 that overlap the upper surface of the lower plate portion 24 and are screwed to the lower plate portion 24. The front ends of the right plate portion 42 and the left plate portion 43 are provided with front stoppers 45 and 46. The front stoppers 45 and 46 extend inward in the left-right direction and overlap the left and right ends of the front plate portion 27 from the rear, respectively, and are screwed to the front plate portion 27. The rear end of the lower plate portion 24 is provided with a rear extension plate portion 53 that extends downward. The rear extension plate portion 53 is provided with rear stoppers 55-57. The rear stoppers 55-57 are screwed to the inner surface of the rear wall portion 33 of the inner case 20.

In the water heater 1 having the above configuration, the lower plate portion 24 and support plate 23 that make up the support member 22 are integrated with screws. By releasing the screws on the rear stoppers 55-57, an operator can easily pull the burner group 25, which remains in a parallel arrangement, out of the inner case 20 together with the support member 22. This improves the maintainability of the water heater 1.

Note that the present invention is not limited to the above embodiment and various modifications are possible. While the water heater 1 is a latent heat recovery type, it may also be a sensible heat recovery type with a single heat exchanger.

The first right stopper 47 and the first left stopper 49 of the support plate 23 extend inward in the left-right direction, but may also extend outward.

The first rear bulge 37 and second rear bulge 38 provided on the inner surface of the rear wall 33 of the case body 21 may be omitted. In this embodiment, the rear bulge provided on the inner surface of the rear wall 33 of the case body 21 includes two rear bulges, a first rear bulge 37 and a second rear bulge 38, separated in the center, but the number of rear bulges is not limited. Multiple rear bulges are preferable to one. By providing multiple rear bulges, the rear stop portions 56 of the rear extension plate portion 53 can be positioned between each bulge, improving the adhesion of the rear extension plate portion 53 to the inner surface of the rear wall 33.

The right bulge portion 35 and the left bulge portion 36 have a special, approximately triangular cross section perpendicular to the longitudinal direction, but the bulge shape is not particularly limited. For example, they may have the same cross-sectional shape as the first rear bulge portion 37 and the second rear bulge portion 38. In that case, the height positions of the right bulge portion 35 and the left bulge portion 36 may be the same as the height positions of the first rear bulge portion 37 and the second rear bulge portion 38, respectively.

The flow straightening member 80 may be omitted. The flow straightening member 80 has two hooks 86, 87 at the upper end of the front wall 84, but there may be more than two.

REFERENCE SIGNS LIST 1 water heater 2 housing 4 combustion device 20 inner case 22 support member 24 lower plate portion 27 front plate portion 28 front wall 31 right wall portion 32 left wall portion 33 rear wall portion 35 right bulge portion 36 left bulge portion 37 first rear bulge portion 38 second rear bulge portion 41 rear plate portion 42 right plate portion 43 left plate portion 45, 46 front stop portion 47 first right stop portion 49 first left stop portion 51, 52 lower bent piece 53 rear extension plate portion 55-57 rear stop portion 60 burner unit 61 lean side inlet 62 rich side inlet 80 flow straightening member 81 bottom wall 82 right wall 83 left wall 84 front wall 85 rear wall 86, 87 hook piece 88, 89 Fixed piece 351, 361 Plane part 500 Hole part 541, 542 Locking hole 811 Hole

Claims (8)

an inner case having a rear wall portion and a pair of side walls extending forward from both left and right ends of the rear wall portion, the inner case having an open front side;
A plurality of burner units each having a gas inlet at a front side and arranged side by side in the left-right direction with their thickness direction aligned in the left-right direction;
a support member that supports the plurality of burner units arranged side by side within the inner case;
a combustion device having a closing member that closes the front side of the inner case,
The support member is
a lower plate portion disposed below the plurality of burner units and having a plurality of holes through which air flowing from below passes upward;
a rear plate portion, a right plate portion, a left plate portion, and a front plate portion which are erected at the rear end, both left and right end portions, and the front end portion of the lower plate portion, respectively, and which surround and support each of the burner units from the rear, right, left, and front,
The right plate portion and the left plate portion are integrally provided to extend forward from both left and right end portions of the rear plate portion,
a right fastening portion and a left fastening portion are provided at the lower ends of the right plate portion and the left plate portion, respectively, and overlap with an upper surface of the lower plate portion and are screwed to the lower plate portion;
a front stopper portion extending inward in the left-right direction and overlapping each of the left and right end portions of the front plate portion from the rear, and screwed to the front plate portion;
A rear extending plate portion extending downward is provided at the rear end portion of the lower plate portion,
the rear extension plate portion is provided with a rear stop portion that is screwed to the inner surface of the rear wall portion of the inner case ,
left and right bulging portions that bulge toward the inside of the inner case and extend in the front-rear direction are provided on the inner surfaces of the pair of side wall portions,
Left and right extending plate portions extending downward are provided at the left and right end portions of the lower plate portion,
The lower ends of the left and right extending plate portions abut against the upper portions of the left and right bulging portions,
The rear stopper portions are provided at intervals in the left-right direction and are formed to extend further downward than the rear extension plate portion,
a rear bulging portion that bulges inward of the inner case and extends in the left-right direction is provided on the inner surface of the rear wall portion of the inner case between the rear stop portions adjacent to each other with the interval in the left-right direction;
A water heater characterized in that the lower end of the rear extension plate portion abuts against the upper part of the rear bulge portion . the left and right bulging portions bulge toward the inside of the inner case and have flat portions at their upper portions facing upward,
The water heater according to claim 1 , wherein lower ends of the left and right extending plate portions abut against the flat portion. The rear stopper portion is provided at least at three locations on the right end side, the center, and the left end side of the lower end of the rear extension plate portion,
The water heater according to claim 1 or 2 , wherein the rear bulge portion is divided into left and right portions at the rear stopper portion in the center. The water heater according to claim 3 , wherein the height positions of the left and right bulging portions from the lower ends of the pair of side walls are higher than the height position of the rear bulging portion from the lower end of the rear wall portion. 5. The water heater according to claim 1 , wherein the rear bulging portion bulges toward the inside of the inner case and has a dome-shaped cross section perpendicular to the longitudinal direction. A straightening member is fixed to the lower surface of the lower plate portion so as to cover the lower surface from below and straighten the air flowing from below toward the upper surface,
the straightening member is formed in a box shape having a front wall, a right wall, a left wall, a rear wall, and a bottom wall having a plurality of holes, and having an open top;
A hook protruding forward is provided at the upper end of the front wall,
A pair of left and right fixing pieces is provided at the upper end of each of the right wall and the left wall,
The water heater described in any one of claims 1 to 5, characterized in that the straightening member rotates toward the underside of the lower plate portion around the hook piece, with the hook piece hooked from below onto the locking hole provided at the front end of the lower plate portion, and the pair of left and right fixing pieces overlapping the underside of the lower plate portion are fixed to the underside of the lower plate portion by being screwed together with the right and left fastening portions to the lower plate portion. 7. The water heater according to claim 1, wherein the rear extension plate overlaps with an inner surface of the rear wall of the inner case. an inner case having a rear wall portion and a pair of side walls extending forward from both left and right ends of the rear wall portion, the inner case having an open front side;
A plurality of burner units each having a gas inlet at a front side and arranged side by side in the left-right direction with their thickness direction aligned in the left-right direction;
a support member that supports the plurality of burner units arranged side by side within the inner case;
a closing member that closes the front side of the inner case;
a combustion device having
The support member is
a lower plate portion disposed below the plurality of burner units and having a plurality of holes through which air flowing from below passes upward;
a rear plate portion, a right plate portion, a left plate portion, and a front plate portion that are erected at the rear end, both left and right ends, and the front end of the lower plate portion, respectively, and that surround and support each of the burner units from the rear, right, left, and front;
Equipped with
The right plate portion and the left plate portion are integrally provided to extend forward from both left and right end portions of the rear plate portion,
a right fastening portion and a left fastening portion are provided at the lower ends of the right plate portion and the left plate portion, respectively, and overlap with an upper surface of the lower plate portion and are screwed to the lower plate portion;
a front stopper portion extending inward in the left-right direction and overlapping each of the left and right end portions of the front plate portion from the rear, and screwed to the front plate portion;
A rear extending plate portion extending downward is provided at the rear end portion of the lower plate portion,
the rear extension plate portion is provided with a rear stop portion that is screwed to the inner surface of the rear wall portion of the inner case,
A rectifying member is fixed to the lower surface of the lower plate portion so as to cover the lower surface from below and rectify the air flowing from below toward the upper side,
the straightening member is formed in a box shape having a front wall, a right wall, a left wall, a rear wall, and a bottom wall having a plurality of holes, and is open at the top;
A hook protruding forward is provided at the upper end of the front wall,
A pair of left and right fixing pieces is provided at the upper end of each of the right wall and the left wall,
The rectifying member rotates toward the underside of the lower plate portion around the hook piece with the hook piece hooked from below onto the locking hole provided at the front end of the lower plate portion, and the pair of left and right fixing pieces superimposed on the underside of the lower plate portion are fastened together with the right and left fastening parts to the lower plate portion with screws, thereby being fixed to the underside of the lower plate portion.
A water heater characterized by the above.