Combustion equipment and water heaters

Abstract

To provide a burner which can prevent a positional displacement of a burner unit.SOLUTION: A water heater comprises a burner 3 in a box body. The burner 3 comprises a unit group 23, an inner case 20, a support plate 22, a lower plate part 24 and a front plate part 25. Since the front plate part 25 and the lower plate part 24 are different bodies, the unit group 23 can be set between a right plate part 42 and a left plate part 43 in a state that the support plate 22 and the lower plate part 24 are fixed to the inside of the inner case 20. In a state that a plurality of burner units 51 are arranged at an upper face of the lower plate part 24, rear parts of the burner units can be supported to a back plate part, and a positional displacement of the burner units 51 in the inner case 20 can be thereby prevented. After that, a worker screw-fixes the front plate part 25 to a pair of left and right inner bent pieces 47, 48 of the support plate 22, and a pair of left and right upper bent pieces 66, 67 of the lower plate part 24 from the front.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a combustion device and a water heater. [Background technology]

[0002] The combustion device of the water heater described in Patent Document 1 includes an inner case. A support plate, an inner plate, and a plurality of burner units are housed inside the inner case. The support plate has a pair of left and right side plate parts and a back plate part, and the pair of left and right side plate parts are fixed so as to be positioned on the inner surface of the left and right side wall parts of the inner case. The inner plate is formed in an L-shape in a side view with the lower plate part and the front plate part integrated together, and the lower plate part is assembled so as to be close to the lower side of each of the lower ends of the pair of left and right side plate parts. A plurality of burner units are arranged in a space surrounded by the front plate part, the pair of left and right side plate parts, and the back plate part. The plurality of burner units are light and dark burners formed in a flat shape, and are arranged so that their thickness direction is in the left and right direction. The rear part of the burner unit is engaged by the back plate part, the front part is engaged by the front plate part, and the bottom part is supported from below by the lower plate part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-67220 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the combustion device described in Patent Document 1, since the lower plate and the front plate, which are the inner plates, are integrated, it is necessary to place the burner units inside the support plate and engage their rear parts with the back plate before assembling the inner plate. Since the rear parts of the burner units are engaged with the back plate without the lower plate, it is difficult to perform the work stably. As a result, there is a possibility that the burner units may become misaligned inside the inner case.

[0005] An object of the present invention is to provide a combustion device and a water heater capable of preventing displacement of a burner unit. [Means for solving the problem]

[0006] The combustion device of claim 1 comprises a unit group in which a plurality of burner units are arranged in the left-right direction, a rear wall portion, a pair of left and right side wall portions extending forward from both left and right ends of the rear wall portion, and a bottom wall portion connected to the rear wall portion and the pair of left and right side wall portions to close the lower surface, an inner case that houses the unit group inside, a back plate portion that is arranged on the inner side of the rear wall portion and supports rear portions of each of the plurality of burner units, and a pair of left and right horizontal plate portions that are arranged on the inner side of each of the pair of left and right side wall portions, a support plate that is arranged between the inner case and the unit group, a lower plate portion that is arranged adjacent to the lower end portions of each of the pair of left and right horizontal plate portions and supports the unit group from below, and a support plate that is fixed to each of the pair of left and right horizontal plate portions and a front end portion of the lower plate portion, and a front plate portion disposed in front of the group of units, wherein a pair of left and right inner bent pieces bent toward the inside in the left-right direction of the inner case are provided at the front end portions of each of the pair of side plate portions, a pair of left and right upper bent pieces bent upward are provided on both left and right sides of the front end portion of the lower plate portion, each of the inner bent pieces and the upper bent piece is provided with a first fixing hole penetrating in the front-rear direction, and a second fixing hole penetrating in the front-rear direction is provided in a portion of the front plate portion corresponding to the first fixing hole, and the front plate portion is fixed to the pair of left and right inner bent pieces and the pair of left and right upper bent pieces by fastening screws from the front into the first fixing hole and the second fixing hole with the front plate portion abutting against the front faces of the pair of left and right inner bent pieces and the pair of left and right upper bent pieces from the front. A protruding plate portion is provided at a lower portion of the front end portion of each of the pair of left and right horizontal plate portions, the protruding plate portion protruding forward from the inner bent piece and the upper bent piece. It is characterized by the above.

[0007]

[0008] Claim 2The portion of the outer edge of the upper bent piece of the combustion device that is located outside in the left-right direction of the lower plate portion is formed so that its height decreases toward the outside, and the lower end portion of the protruding plate portion may be provided with an inclined portion that slopes downward in height from the front side to the rear side.

[0009] Claim 3 A gap corresponding to a thickness of the protruding plate portion may be formed between the upper bent piece of the combustion device and the inner case.

[0010] Claim 4 The water heater according to claim 1 3 The present invention is characterized in that it comprises the combustion device according to any one of the above. Effect of the Invention

[0011] According to the combustion device of claim 1, since the front plate portion and the lower plate portion are separate from each other, in a state where the support plate and the lower plate portion are arranged inside the inner case, the burner units can be arranged in sequence on the upper surface of the lower plate portion while the rear portion of each can be supported by the back plate portion. This allows the worker in the assembly to reliably arrange the burner units in the determined positions. Therefore, the combustion device can prevent the positional deviation of the burner units in the inner case. After that, the worker abuts the front plate portion from the front against a pair of left and right inner bent pieces provided on the front end portions of each of the pair of left and right side plate portions and a pair of left and right upper bent pieces provided on the front end portion of the lower plate portion, and fixes them with screws. The front end portions of each of the pair of left and right side plate portions and the front end portion of the lower plate portion are fixed to the front plate portion. This allows the combustion device to prevent the relative positions of the side plate portions and the lower plate portions from being shifted.

[0012] Also If the worker were to attempt to assemble the lower plate from the front when the side plate is bent inward, the rear surface of the upper bent piece would interfere with the tip of the protruding plate, causing the lower plate to stop at a position that protrudes further forward than the inner bent piece. This allows the worker to notice that the side plate is bent inward, preventing the product from being supplied in an incorrectly assembled state.

[0013] Claim 2 According to the combustion device, even if the horizontal plate portion is bent inward and the protruding plate portion interferes with the upper bent piece, by pushing the lower plate portion further forward, the inclined portion formed at the lower end of the protruding plate portion comes into contact with the outer edge of the upper bent piece. Then, the inclined portion slides down along the outer edge of the upper bent piece, pushing the protruding plate portion outward. This allows the combustion device to guide the protruding plate portion outward and back to its normal position. Therefore, the combustion device can improve the work efficiency when fixing the lower plate portion inside the inner case.

[0014] Claim 3 According to the combustion apparatus of the above, even when the horizontal plate portion is curved inward, the protruding plate portion can be supported from the inside in the left-right direction by the outer edge portion of the upper bent piece.

[0015] Claim 4 According to the water heater of claim 1, 3 The present invention is provided with a combustion device according to any one of claims 1 to 5. 3 The above-mentioned effects can be obtained. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a front view of the water heater 1. [Diagram 2] FIG. 2 is a perspective view of the combustion device 3. [Diagram 3] FIG. 2 is an exploded perspective view of the combustion device 3. [Figure 4] 2 is a perspective view of the case body 21 before the lower plate portion 24 is fixed thereto. FIG. [Diagram 5] 2 is a plan view of the case body 21 before the lower plate portion 24 is fixed thereto. [Figure 6] 2 is a perspective view of a state in which a lower plate portion 24 is fixed inside a case body 21. FIG. [Figure 7] 2 is a plan view of a state in which a lower plate portion 24 is fixed inside a case body 21. FIG. [Figure 8] 7 is a perspective view (with the right wall of the case body 21 cut away) of a state in which a unit group 23 is installed in the case body 21 shown in FIG. 6. FIG. [Figure 9] 9 is a perspective view (with the right wall of the case body 21 cut away) of a state in which a front plate portion 25 is fixed to the front side of the case body 21 shown in FIG. 8. FIG. [Figure 10] 13 is a plan view showing a state in which the left plate portion 43 of the support plate 22 is curved inward and before the lower plate portion 24 is fixed inside the case body 21. FIG. [Figure 11] 13 is a plan view showing a state in which an upper bent piece 67 interferes with the tip of a protruding plate portion 50. FIG. [Figure 12] 12 is a partially enlarged view of the periphery of a protruding plate portion 50 shown in FIG. 11. FIG. [Figure 13] 13 is a partial enlarged view showing a state in which the lower plate portion 24 is pushed further toward the rear from the state shown in FIG. 12. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described. Unless otherwise specified, the device configuration described below is not intended to be limiting, but is merely an explanatory example. The drawings are used to explain technical features that can be adopted by the present invention.

[0018] The configuration of water heater 1 will be described with reference to Figure 1. Water heater 1 has a combustion device 3, a heat exchanger 4, and an exhaust hood 5 installed in that order from bottom up inside a square box-shaped housing 2. A gas supply unit 6 is attached to the front of the combustion device 3. The gas supply unit 6 distributes and supplies gas to a group of units 23 (see Figure 2) within the combustion device 3, which will be described later. A fan 7 is attached to the underside of the combustion device 3. The fan 7 supplies combustion air to the combustion device 3.

[0019] A controller 8 housing an electrical circuit board is installed upright horizontally on the inner bottom surface of the housing 2, in front of the fan 7 and below the combustion device 3. The heat exchanger 4 has a plurality of fins (not shown) inside the casing at predetermined intervals in the left-right direction, and a heat transfer tube 9 that penetrates each fin in a serpentine shape, and exchanges heat between the exhaust combustion air passing between the fins from below and the water flowing inside the heat transfer tube 9. The exhaust hood 5 has an exhaust pipe 10 in a horizontally elongated oval shape on the front side. The exhaust pipe 10 penetrates the front cover (not shown) and protrudes forward, discharging the exhaust combustion air that has passed through the heat exchanger 4 to the outside.

[0020] A gas inlet 11, a water inlet 12, and a hot water outlet 13 are provided on the underside of the casing 2. An external gas pipe (not shown) is connected to the gas inlet 11. A water pipe (not shown) is connected to the water inlet 12. A piping (not shown) to a hot water tap is connected to the hot water outlet 13. The gas inlet 11 is connected to the gas supply unit 6 within the casing 2 via a gas pipe 14 equipped with a main valve, a proportional valve, etc. The water inlet 12 is connected to the upstream end of the heat transfer tube 9 of the heat exchanger 4 via a water supply pipe 15. The hot water outlet 13 is connected to the downstream end of the heat transfer tube 9 via a hot water outlet pipe 16.

[0021] The structure of the combustion device 3 will be described with reference to Figures 2 and 3. The combustion device 3 includes an inner case 20 in the shape of a square box. The inner case 20 is housed in the housing 2. A unit group 23 is attached to the inside of the inner case 20. The unit group 23 includes a plurality of flat burner units 51 stacked in the left-right direction, and has a substantially rectangular parallelepiped shape. The inner case 20 includes a case body 21 and a front wall 26, and is made of metal (e.g., aluminum-plated steel sheet). The case body 21 is open at the top and front. The front wall 26 is attached to the front of the case body 21. The unit group 23 is supported on the inside of the case body 21 by a support plate 22, a lower plate portion 24, and a front plate portion 25, which will be described later.

[0022] As shown in FIG. 3, the case body 21 includes a right wall portion 31, a left wall portion 32, a rear wall portion 33, a bottom wall portion 34, and an overheat protection plate 38. A rising portion 36 is formed by bending upward over the entire length at the upper end of the rear wall portion 33 and at the upper ends of the right wall portion 31 and the left wall portion 32. The rising portion 36 has a substantially L-shaped cross section. A plurality of crimping pieces 37 are provided at predetermined intervals on each rising portion 36. Fixing pieces 311, 321 are formed by bending outward at the front ends of the right wall portion 31 and the left wall portion 32, respectively. The front wall 26 and the gas supply unit 6 (see FIG. 1) are screwed to the fixing pieces 311, 321. A rectangular opening 35 to which the fan 7 is connected is provided at the left rear portion of the bottom wall portion 34.

[0023] The overheat protection plate 38 is a horizontally long rectangular metal plate (e.g., a stainless steel plate) that is attached to cover the upper portion of the inner surface of the rear wall portion 33 with a gap therebetween. A bulge 331 is provided on the rear wall portion 33 below the overheat protection plate 38 and protrudes rearward. The bulge 331 has a horizontally long rectangular shape extending in the left-right direction. A rail portion 312 that protrudes inward is provided on the lower side of the inner surface of the right wall portion 31. A rail portion 322 that protrudes inward is also provided on the lower side of the inner surface of the left wall portion 32 at the same height as the rail portion 312. The rail portions 312, 322 extend approximately horizontally in the front-rear direction.

[0024] The support plate 22 includes a back plate portion 40, a right plate portion 42, and a left plate portion 43, and is formed in a generally U-shape in plan view that opens toward the front. The support plate 22 is also made of metal. The back plate portion 40 is a horizontally elongated rectangular shape in front view, and is provided along the inner surface of the rear wall portion 33. The right plate portion 42 and the left plate portion 43 are bent forward from the right end and the left end of the back plate portion 40. A fitting portion 44 is provided on the back plate portion 40 so as to protrude backward. The fitting portion 44 has the same shape as the bulging portion 41, and fits into the bulging portion 41 from the front. A plurality of support pieces 45 are bent forward at equal intervals in the left-right direction on the upper edge of the back plate portion 40. A slit 45A is provided on the support piece 45. The slit 45A extends downward. A plurality of support pieces 46 are also bent forward at equal intervals in the left-right direction on the lower edge of the back plate portion 40.

[0025] The right plate portion 42 and the left plate portion 43 have a width in which the unit group 23 can be accommodated, and extend forward inside the right wall portion 31 and the left wall portion 32. The right plate portion 42 includes, from the rear side to the front side, a rear extension portion 421, a step portion 422, and a front extension portion 423. The rear extension portion 421 extends forward from the right end portion of the back plate portion 40 to approximately the center portion of the right plate portion 42 in the front-rear direction. The step portion 422 is bent rightward from the front end portion of the rear extension portion 421 and extends rightward. The front extension portion 423 is bent forward from the right end portion of the step portion 422 and extends forward. An inner bent piece 47 having a fixing hole 471 is bent inwardly at a portion of the front end portion of the front extension portion 423 except for the lower portion.

[0026] A protruding plate portion 49 is provided at the lower part of the front end portion of the front extension portion 423, protruding further forward than the inner bent piece 47. The upper end portion of the protruding plate portion 49 extends substantially horizontally in the front-rear direction, and the front end portion of the protruding plate portion 49 extends parallel in the up-down direction. An inclined portion 491 (see FIG. 8) is provided on the front end side of the lower end portion of the protruding plate portion 49. The height position of the inclined portion 491 decreases from the front end toward the rear, and the inclined portion 491 inclines downward.

[0027] Like the right plate portion 42, the left plate portion 43 also includes, from the rear side to the front side, a rear extension portion 431, a step portion 432, and a front extension portion 433. The rear extension portion 431 extends forward from the left end portion of the back plate portion 40 to approximately the center portion of the left plate portion 43 in the front-to-rear direction. The step portion 432 is bent leftward from the front end portion of the rear extension portion 431 and extends leftward. The front extension portion 433 is bent forward from the left end portion of the step portion 432 and extends forward. An inner bent piece 48 having a fixing hole 481 is bent inwardly at a portion of the front end portion of the front extension portion 433 except for the lower portion thereof.

[0028] A protruding plate portion 50 is also provided at the lower part of the front end portion of the front extension portion 433, protruding further forward than the inner bent piece 48. The protruding plate portion 50 has the same shape as the protruding plate portion 49, and an inclined portion 501 is provided on the front end side of the lower end portion of the protruding plate portion 50. The inclined portion 501 also becomes lower in height from the front end toward the rear, and inclines downward.

[0029] Each burner unit 51 constituting the unit group 23 is a well-known rich / lean burner. The burner unit 51 is equipped with a lean side inlet 53, a rich side inlet 54, a mixing section 55, and a flame hole section 56. The lean side inlet 53 is a lower opening that opens forward and introduces fuel gas and primary air, and the rich side inlet 54 is an upper opening. The mixing section 55 is provided downstream of the lean side inlet 53 and the rich side inlet 54, and the inside is separated for each inlet. The flame hole section 56 opens at the upper end of the mixing section 55 and consists of a lean flame hole in the center and rich flame holes on both the left and right sides of the lean flame hole.

[0030] The lower plate portion 24 is also made of metal, and is formed in a generally rectangular shape that is elongated in the left-right direction in a plan view. A plurality of small holes 611 are formed in the lower plate portion 24 at predetermined intervals in the front-rear and left-right directions. A screw fastening piece 61 is formed by bending downwards at the rear end of the lower plate portion 24. Lower bent pieces 63, 64 are formed downwards at the right and left edges of the lower plate portion 24. The lower bent pieces 63, 64 are generally rectangular and elongated in the front-rear direction in a side view.

[0031] An upper bent piece 66 is bent upward at the right end of the front end of the lower plate portion 24. An upper bent piece 67 is bent upward at the left end of the front end of the lower plate portion 24. The upper bent piece 66 is generally semicircular in front view, and the right part of its outer edge 662 forms an arc-shaped tapered part whose height decreases toward the right (see FIG. 4). The upper bent piece 67 is also generally semicircular in front view, bilaterally symmetrical to the upper bent piece 66, and the left part of its outer edge 672 forms an arc-shaped tapered part whose height decreases toward the left (see FIG. 4). The upper bent pieces 66, 67 are provided with fixing holes 661, 671 penetrating in the front-rear direction, respectively.

[0032] The front plate 25 is also made of metal and is formed into a generally horizontally elongated rectangular shape when viewed from the front. The front plate 25 is fixed to the inner bent pieces 47, 48 of the support plate 22 and the upper bent pieces 66, 67 of the lower plate 24. A plurality of support pieces 65 are formed on the upper edge of the front plate 25 by bending them backward at equal intervals in the left-right direction.

[0033] Below the multiple support pieces 65, a pair of upper and lower lean gas supply holes 6A and rich gas supply holes 6B are arranged in parallel in the left-right direction. The lower lean gas supply hole 6A is an oval burring hole. The upper rich gas supply hole 6B is a circular burring hole. Front bent pieces 68, 69 are formed facing forward at the right and left ends of the front plate portion 25. Fixing holes 621, 623 are provided at the middle and lower parts in the height direction of the right end of the front plate portion 25. Fixing holes 622, 624 are provided at the middle and lower parts in the height direction of the left end of the front plate portion 25.

[0034] The front wall 26 is made of metal and has a generally rectangular shape elongated from the front. A rising portion 74 is provided on the upper edge of the front wall 26. The rising portion 74 is bent upward over the entire length of the upper edge of the front wall 26 and has a generally L-shaped cross section. A plurality of crimping pieces 75 are provided in the rising portion 74 in the left-right direction at a predetermined interval. A mounting hole 71, a mounting hole 72, and a through hole 73 are provided at a predetermined interval from the right side to the left side in the middle part of the height direction of the front wall 26. A discharge electrode (not shown) for ignition is attached to the mounting hole 71. A flame rod (not shown) as a flame detection electrode is attached to the mounting hole 72. A sight glass (not shown) is attached to face the through hole 73.

[0035] An example of a method for assembling the combustion device 3 will be described with reference to Figs. 3 to 9. As shown in Figs. 3 and 4, an operator places the support plate 22 inside the case body 21, and fixes it to the rear wall 33 with rivets (not shown) at a position where the fitting portion 44 of the support plate 22 fits into the bulging portion 331. At this time, the upper portion of the support plate 22 is overlapped with the lower portion of the overheating prevention plate 38 from the front, and the lower portion of the overheating prevention plate 38 is pressed against the rear wall 33 to be fixed. The right surface of the front extension portion 423 of the right plate portion 42 of the support plate 22 abuts against the inner surface of the right wall portion 31. The left surface of the front extension portion 433 of the left plate portion 43 abuts against the inner surface of the left wall portion 32.

[0036] 3 to 5, the worker places the lower plate portion 24 on the front side of the case body 21, and slides the lower bent pieces 63, 64 of the lower plate portion 24 toward the rear side of the case body 21 along the upper surfaces of the rail portions 312, 322 inside the case body 21. At this time, as shown in FIG. 5, a predetermined gap P1 is formed between the upper bent piece 66 and the inner surface of the right wall portion 31 on the right side of the lower plate portion 24. A predetermined gap P2 is formed between the upper bent piece 67 and the inner surface of the left wall portion 32 on the left side of the lower plate portion 24.

[0037] From this state, by moving the lower plate portion 24 toward the rear side of the case body 21, the right protruding plate portion 49 of the support plate 22 is inserted from behind into the gap P1, and the left protruding plate portion 50 of the support plate 22 is inserted from behind into the gap P2 (see FIGS. 6 and 7). At this time, the protruding plate portions 49, 50 protrude forward further than the upper bent pieces 66, 67 and the inner bent pieces 47, 48.

[0038] The gaps P1, P2 should be designed to have a width corresponding to the thickness of each of the protruding plate portions 49, 50, and more specifically, should be the same as the thickness of the protruding plate portions 49, 50. In this case, the protruding plate portions 49, 50 are inserted into the gaps P1, P2 and are locked by being sandwiched between the upper bent pieces 66, 67 and the right wall portion 31 and the left wall portion 32. As a result, the protruding plate portions 49, 50 are supported from the inside by the outer edge portions 662, 672 of the upper bent pieces 66, 67.

[0039] The screw fastening piece 61 of the lower plate portion 24 abuts against the front surface of the rear wall portion 33. The worker fastens the screw fastening piece 61 to the front surface of the rear wall portion 33 from the front with two screws 81, 82 on the left and right. As a result, as shown in Figs. 6 and 7, the lower plate portion 24 is fixed inside the case main body 21 and disposed directly below the support plate 22. The lower bent pieces 63, 64 are supported from below by the rail portion 312 of the right wall portion 31 and the rail portion 322 of the left wall portion 32. The lower bent pieces 63, 64 abut against the respective inner surfaces of the right wall portion 31 and the left wall portion 32. In the front-rear direction of the case main body 21, the upper bent piece 66 on the right side of the lower plate portion 24 is disposed in the same position as the inner bent piece 47 on the right side of the support plate 22, and the upper bent piece 67 on the left side of the lower plate portion 24 is disposed in the same position as the inner bent piece 48 on the left side of the support plate 22.

[0040] 8, the worker places the twelve burner units 51 in the left-right order on the upper surface of the lower plate 24. Then, the multiple support pieces 45, 46 provided on the back plate 40 of the support plate 22 are engaged between the burner units 51. Since the worker can place the burner units 51 on the upper surface of the lower plate 24 while supporting their rear parts on the back plate 40, the burner units 51 can be set stably.

[0041] 9, the worker places the front plate portion 25 facing the front side of the unit group 23. Then, the multiple support pieces 65 provided on the upper end portion of the front plate portion 25 are engaged between the burner units 51. Next, the right fixing hole 621 of the front plate portion 25 is aligned with the position of the fixing hole 471 of the right inner bent piece 47 of the support plate 22, and the front plate portion 25 is fixed from the front with a screw 83. Furthermore, the right fixing hole 623 of the front plate portion 25 is aligned with the position of the fixing hole 661 of the upper bent piece 66 of the lower plate portion 24, and the front plate portion 25 is fixed with a screw 95 from the front.

[0042] Next, the left fixing hole 622 of the front plate portion 25 is aligned with the position of the fixing hole 481 of the left inner bent piece 48 of the support plate 22, and fixed from the front with a screw 84. Furthermore, the left fixing hole 624 of the front plate portion 25 is aligned with the position of the fixing hole 671 of the upper bent piece 67 of the lower plate portion 24, and fixed with a screw 96 from the front. As a result, the front plate portion 25 is fixed to the support plate 22 and the lower plate portion 24, and the unit group 23 is sandwiched between the front plate portion 25 and the back plate portion 40 of the support plate 22.

[0043] The front bent pieces 68, 69 of the front plate portion 25 abut against the inner surfaces of the right wall portion 31 and the left wall portion 32. The lean gas supply hole 6A of the front plate portion 25 faces the lean side inlet 53 of the corresponding burner unit 51. The rich gas supply hole 6B faces the rich side inlet 54 of the corresponding burner unit 51. This allows the gas supply unit 6 to supply gas to each of the multiple burner units 51 via the multiple lean gas supply holes 6A and rich gas supply hole 6B.

[0044] 2, the worker places the front wall 26 so as to cover the upper half of the front surface of the case body 21, and fixes it to the fixing piece 311 of the right wall portion 31 and the fixing piece 321 of the left wall portion 32 with screws 87, 91, 88, and 92, and fixes it to the front plate portion 25 with screws 89 and 90. In this manner, the combustion device 3 is completed.

[0045] 10 to 13, a case will be described where the lower plate portion 24 is to be fixed in a state where the left plate portion 43 of the support plate 22 is curved inward. As described above, the support plate 22 is made of metal and has a substantially U-shape that opens toward the front side in a plan view, so that when the back plate portion 40 is fixed to the rear wall portion 33 of the case body 21, one or both of the right plate portion 42 and the left plate portion 43 may be curved inward.

[0046] For example, assume that the left plate portion 43 is slightly curved inward as shown in Fig. 10. In this case, the protruding plate portion 50 provided at the front end portion of the left plate portion 43 is located slightly to the right of the right surface of the left wall portion 32. If the curvature of the left plate portion 43 is small, the worker often does not notice it. Without noticing the curvature of the left plate portion 43, the worker slides the lower plate portion 24 from the front to the back along the rail portions 312, 322 of the case body 21 in order to fix the lower plate portion 24.

[0047] 10, when the case body 21 is viewed from the front, the protruding plate portion 50 does not face the gap P2, but faces the back surface of the upper bent piece 67. In this state, the worker slides the lower plate portion 24 from the front to the back.

[0048] In this case, as shown in Figures 11 and 12, the protruding plate portion 50 interferes with the back surface of the upper bent piece 67 without being inserted into the gap P2. The lower plate portion 24 stops at the position where the protruding plate portion 50 interferes with the back surface of the upper bent piece 67. Compared to the correct position, the left side of the lower plate portion 24 protrudes significantly forward. Note that the correct position refers to the position of the lower plate portion 24 when it is properly fixed inside the case body 21. By checking the position of the lower plate portion 24, the worker can easily notice that the lower plate portion 24 has been assembled incorrectly.

[0049] To eliminate the incorrect assembly of the lower plate 24, the worker, for example, pulls the lower plate 24 back toward himself, straightens the inwardly curved left plate 43 along the right surface of the left wall 32, and then slides the lower plate 24 back again. This allows the protruding plate 50 to be inserted into the gap P2 from the rear, and the lower plate 24 can be fixed in the correct position inside the case body 21. Therefore, the relative positions of each burner unit 51 of the unit group 23 and the multiple small holes 611 of the lower plate 24 do not shift. Therefore, the combustion device can stably supply a predetermined amount of secondary air from the multiple small holes 611 to each burner unit 51.

[0050] 12, the worker may further push the lower plate 24 toward the rear (see arrow F1 in FIG. 12). In this case, the inclined portion 501 of the protruding plate 50 comes into contact with the left portion of the outer edge 672 of the upper bent piece 67. Then, as shown in FIG. 13, by pushing the lower plate 24 further toward the rear (see arrow F1 in FIG. 13), the upper bent piece 67 moves further toward the rear (see arrow T1 in FIG. 13), so that the inclined portion 501 of the protruding plate 50 slides down along the left portion of the outer edge 672. Accordingly, the protruding plate 50 is pushed outward to the left (see arrow T2 in FIG. 13), and as a result, it is automatically disposed in the gap P2 between the upper bent piece 67 and the right surface of the left wall 32. Therefore, the protruding plate 50 is stably supported from the inside in the left-right direction by the outer edge 672 of the upper bent piece 67.

[0051] In this way, even when the left plate portion 43 of the support plate 22 is curved inward, by sliding and pushing the lower plate portion 24 toward the back of the case body 21, the left plate portion 43 is pushed outward via the protruding plate portion 50, and the lower plate portion 24 is guided to the correct position. In other words, since there is no need to correct the position of the curved left plate portion 43, the combustion device 3 can improve the work efficiency when fixing the lower plate portion 24 inside the case body 21. Note that, although this embodiment has been described for the case where the left plate portion 43 of the support plate 22 is curved inward, the same applies to the case where the right plate portion 42 is curved inward.

[0052] As described above, the water heater 1 of this embodiment includes the combustion device 3. The combustion device 3 includes the unit group 23, the inner case 20, the support plate 22, the lower plate 24, and the front plate 25. The unit group 23 includes a plurality of burner units 51 arranged in the left-right direction. The inner case 20 includes a rear wall 33, a right wall 31, a left wall 32, and a bottom wall 34, and houses the unit group 23 inside. The right wall 31 and the left wall 32 extend forward from both the left and right ends of the rear wall 33. The bottom wall 34 is connected to the rear wall 33, the right wall 31, and the left wall 32 to close the lower surface. The support plate 22 includes a back plate 40, a right plate 42, and a left plate 43, and is disposed between the inner case 20 and the unit group 23. The lower plate portion 24 is disposed adjacent to the lower ends of the right plate portion 42 and the left plate portion 43, and supports the unit group 23 from below. The front plate portion 25 is fixed to the front ends of the right plate portion 42 and the left plate portion 43, and is disposed in front of the unit group 23.

[0053] A pair of left and right inner bent pieces 47, 48 are provided at the front end of each of the right plate portion 42 and the left plate portion 43. The inner bent pieces 47, 48 are bent inward in the left-right direction of the inner case 20. A pair of left and right upper bent pieces 66, 67 are provided on both the left and right sides of the front end of the lower plate portion 24. The upper bent pieces 66, 67 are bent upward. The inner bent pieces 47, 48 are provided with fixing holes 471, 481 penetrating in the front-rear direction. The upper bent pieces 66, 67 are provided with fixing holes 661, 671 penetrating in the front-rear direction. Fixing holes 621, 622, 623, 624 penetrating in the front-rear direction are provided in portions of the front plate portion 25 corresponding to the fixing holes 471, 481, 661, 671. The front panel portion 25 is fixed to the inner bent pieces 47, 48 and the upper bent pieces 66, 67 by fastening screws 83, 84, 95, 96 from the front into fixing holes 471, 481, 661, 671 and fixing holes 621, 622, 623, 624 while being abutted from the front against the front surfaces of the inner bent pieces 47, 48 and the upper bent pieces 66, 67, respectively.

[0054] Since the front plate portion 25 and the lower plate portion 24 are separate bodies, the unit group 23 can be set between the right plate portion 42 and the left plate portion 43 with the right plate portion 42 and the left plate portion 43 of the support plate 22 and the lower plate portion 24 arranged inside the inner case 20. With the unit group 23 arranged on the upper surface of the lower plate portion 24, the rear portions of the burner units 51 can be supported by the back plate portion, so that the unit group 23 can be set stably. After that, the front plate portion 25 is abutted from the front against a pair of left and right inner bent pieces 47, 48 provided at the front ends of the right plate portion 42 and the left plate portion 43, respectively, and a pair of left and right upper bent pieces 66, 67 provided at the front end of the lower plate portion 24, and fixed with screws. Since the front end portions of the right plate portion 42 and the left plate portion 43 and the front end portion of the lower plate portion 24 are fixed to the front plate portion 25, it is possible to prevent the relative positional relationship between the right plate portion 42, the left plate portion 43 and the lower plate portion 24 from shifting.

[0055] In the above description, the right wall 31 and the left wall 32 of the inner case 20 are an example of a "pair of left and right side walls" of the present invention. The right plate 42 and the left plate 43 of the support plate 22 are an example of a "pair of left and right horizontal plates" of the present invention. The fixing holes 471, 481 provided in the inner bent pieces 47, 48 and the fixing holes 661, 671 provided in the upper bent pieces 66, 67 are an example of a "first fixing hole" of the present invention. The fixing holes 621, 622, 623, 624 provided in the front plate 25 are an example of a "second fixing hole" of the present invention. The screws 83, 84, 95, 96 are an example of a "screw" of the present invention.

[0056] The present invention is not limited to the above embodiment, and various modifications are possible. The water heater 1 shown in Fig. 1 is a normal water heater equipped with one heat exchanger 4, but it may be a latent heat recovery type water heater equipped with two heat exchangers, one for sensible heat recovery and one for latent heat recovery.

[0057] The outer edge portions 662, 672 of the upper bent pieces 66, 67 are arched in shape with the height decreasing from approximately the center in the left-right direction in a front view to both the left and right sides, but may be other shapes. Preferably, the portion located on the outer side in the left-right direction of the lower plate portion 24 is made to have a height decreasing toward the outer side. For example, only the right side of the outer edge portion 662 of the upper bent piece 66 may be formed so that the height decreases toward the right, and only the left side of the outer edge portion 672 of the upper bent piece 67 may be formed so that the height decreases toward the left. The shape of the inner bent pieces 47, 48 is not limited to the above embodiment.

[0058] The protruding plate portions 49, 50 have inclined portions 491, 501 at their lower ends, but these may be omitted. The tip shapes of the protruding plate portions 49, 50 may be rectangular, arcuate, triangular, or the like, in addition to those in the above embodiment.

[0059] The number of burner units 51 constituting the unit group 23 may be more than one, and may be more or less than the twelve in the above embodiment. [Explanation of symbols]

[0060] 1. Water heater 3 Combustion equipment 20 Inner case 22 Support plate 23 Unit Group 24 Lower plate part 25 Front plate part 31 Right wall 32 Left wall 33 Rear wall 34 Bottom wall 40 Back plate part 42 Right plate 43 Left plate part 47,48 Inner bend piece 49,50 Projecting plate part 51 Burner unit 66,67 Upper bend 83,84,95,96 Screws 471,481 Fixed hole 491,501 Slope 621~624 Fixed hole 661,671 Fixed hole 662,672 Outer edge P1, P2 gap

Claims

1. A unit group including a plurality of burner units arranged in parallel in the left-right direction; an inner case including a rear wall portion, a pair of left and right side wall portions extending forward from left and right ends of the rear wall portion, and a bottom wall portion connected to the rear wall portion and the pair of left and right side wall portions to close a lower surface, the inner case accommodating the group of units therein; a support plate disposed between the inner case and the group of units, the support plate including a back plate portion disposed on the inner surface side of the rear wall portion and supporting the rear portions of each of the burner units, and a pair of left and right side plate portions disposed on the inner surface sides of each of the pair of left and right side wall portions; a lower plate portion disposed adjacent to each lower end of the pair of left and right horizontal plate portions and supporting the unit group from below; a front plate portion fixed to the front end portions of the pair of left and right side plate portions and the lower plate portion and disposed in front of the group of units; Equipped with A pair of left and right inwardly bent pieces are provided at the front end portions of each of the pair of horizontal plate portions, the left and right inwardly bent pieces being bent inward in the left-right direction of the inner case, A pair of upper bent pieces that are bent upward are provided on both left and right sides of the front end of the lower plate portion, A first fixing hole is provided in each of the inner bent piece and the upper bent piece, the first fixing hole penetrating in the front-rear direction, A second fixing hole is provided in a portion of the front plate portion corresponding to the first fixing hole, the second fixing hole penetrating in the front-rear direction, The front plate portion is fixed to the pair of left and right inner bent pieces and the pair of left and right upper bent pieces by fastening screws from the front into the first fixing holes and the second fixing holes in a state in which the front plate portion abuts against the front surfaces of the pair of left and right inner bent pieces and the pair of left and right upper bent pieces from the front, A protruding plate portion is provided at a lower portion of the front end portion of each of the pair of left and right side plate portions, the protruding plate portion protruding forward further than the inner bent piece and the upper bent piece. A combustion device comprising:

2. a portion of an outer edge of the upper bent piece that is located outside the lower plate in the left-right direction is formed so as to decrease in height as it moves outward, The lower end of the protruding plate is provided with an inclined portion that is inclined so that the height position becomes lower from the front side to the rear side. The combustion device according to claim 1 .

3. A gap corresponding to the thickness of the protruding plate portion is formed between the upper bent piece and the inner case. The combustion device according to claim 1 or 2,

4. The combustion device according to any one of claims 1 to 3 is provided. A water heater characterized by the above.

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