JP2020067219A - Water heater - Google Patents

Abstract

To allow a discharge electrode and a flame detection electrode to be easily attached without displacing a retaining plate.SOLUTION: A water heater comprises an ignition discharge electrode 78 and a frame rod 80 attached to a front wall 24 of an inner case 20 and arranged on the left and the right. The discharge electrode 78 and the frame rod 80 are attached by a retaining plate 84 screwed to a front surface of the front wall 24 while being made to penetrate through attachment holes 79 and 81 provided in the front wall 24. A first bead part 85 in contact with a lower right side of the retaining plate 84 in a front view, and a second bead part 86 in contact with an upper left part of the retaining plate 84 are formed on the front surface of the front wall 24.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a water heater in which a housing has an inner case that houses a burner unit.

The water heater is provided with a combustion device having a burner unit in which a plurality of burners are juxtaposed in the left-right direction in a housing, and a heat exchanger arranged above the combustion device, and a fuel gas and combustion air are provided. The combustion exhaust gas of the burner unit, which ignites and burns the air-fuel mixture, heats the water passing through the heat exchanger to discharge it.
Further, in the combustion apparatus, as disclosed in Patent Document 1, a support plate that supports the burner unit in the left-right direction is fixed in the burner case (inner case), and the inner case is fixed in the housing. It can be assembled. On the front wall of the inner case, an ignition electrode (discharge electrode) to the burner unit and a flame detection frame rod (flame detection electrode) are arranged side by side, and mounting holes are provided on the front wall. It is attached so that it penetrates and projects into the inner case.

JP, 2011-33244, A

  The discharge electrode and the flame detection electrode are fixed by using a holding plate screwed to the front surface of the front wall and sandwiching a flange or the like provided on the discharge electrode between the holding plate and the front wall. . However, when the retaining plate is screwed to the front wall, the retaining plate tends to rotate together with the rotation of the screw, causing a positional shift, which makes the mounting work troublesome.

  Therefore, an object of the present invention is to provide a water heater in which the discharge electrode and the flame detection electrode can be easily attached without the displacement of the pressing plate.

In order to achieve the above object, the invention according to claim 1 is such that a burner unit in which a plurality of burners are juxtaposed in the left-right direction in a housing, an inner case for housing the burner unit, and a front of the inner case. It has an ignition discharge electrode and a flame detection electrode that are attached to the wall and arranged on the left and right, and the discharge electrode and the flame detection electrode are in a state where the attachment hole provided in the front wall is penetrated through the front wall. Is a water heater that is attached by a retaining plate that is screwed to the front of
The front surface of the front wall is characterized in that a first bead portion that abuts on the lower right side of the restraining plate in front view and a second bead portion that abuts on the upper left side of the restraining plate are formed.
According to a second aspect of the present invention, in the configuration of the first aspect, the first bead portion further includes a first sub-bead portion that abuts on the right lateral side of the pressing plate.
According to a third aspect of the present invention, in the configuration of the first or second aspect, the second bead portion further includes a second sub-bead portion that is in contact with the left lateral side of the pressing plate.
According to a fourth aspect of the present invention, in the structure according to any one of the first to third aspects, the inner case has a front wall attached to a front surface of a case body having a rear wall portion and left and right side wall portions. A plurality of crimping pieces are formed on the upper end of the main body and the upper end of the front wall, respectively. It is characterized by being arranged in.

According to the invention described in claim 1, the discharge electrode and the flame detection electrode can be easily attached by the first bead portion and the second bead portion provided on the front surface of the front wall without the displacement of the suppressing plate. be able to.
According to the invention described in claim 2, in addition to the effect of claim 1, the first bead portion further includes the first sub-bead portion, whereby positioning of the presser plate is further facilitated, and misalignment occurs. Prevention will be more effective.
According to the invention described in claim 3, in addition to the effect of claim 1 or 2, the second bead portion further includes a second sub-bead portion, so that the positioning of the presser plate is further facilitated and the position is improved. It becomes more effective by preventing the deviation.
According to the invention as set forth in claim 4, in addition to the effect of any one of claims 1 to 3, caulking pieces are respectively formed at the upper end of the case main body and the upper end of the front wall, and the case main body and the front wall are formed. Since the crimping pieces are arranged at a predetermined interval over the entire circumference of the upper end of the inner case, the front wall can be used for crimping with the casing of the heat exchanger, leading to a reduction in manufacturing cost.

It is a front view of the water heater with the front cover removed. It is a perspective view of a combustion device. It is an exploded perspective view of a combustion device. It is a front view of the combustion apparatus which abbreviated the burner unit. It is the sectional view on the AA line of FIG. It is a partial perspective view which shows the attachment state of the support plate to a case main body. It is a partial perspective view which shows the attachment state of the inner plate and front wall to a case main body. It is a perspective view from the back of a front wall. It is an exploded perspective view of a combustion device before a front wall is attached.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is an explanatory view showing an example of a water heater, and shows a housing 2 from the front with a front cover on the front removed. The water heater 1 includes a rectangular box-shaped casing 2 in which a combustion device 3, a heat exchanger 4, and an exhaust hood 5 are installed in order from below. A gas supply unit 6 for distributing and supplying a fuel gas to a burner unit 21 to be described later in the combustion device 3 is attached to the front surface of the combustion device 3, and a supply air for supplying combustion air is supplied to the lower surface of the combustion device 3. The ki fan 7 is assembled. Below the combustion device 3 on the front side of the air supply fan 7, a controller 8 that accommodates an electrical equipment substrate is erected laterally on the inner bottom surface of the housing 2.
The heat exchanger 4 is provided with a plurality of fins (not shown) inside the casing at predetermined intervals in the left-right direction, and a heat transfer tube 9 penetrating each fin in a meandering manner. It is possible to exchange heat with water flowing in the heat transfer tube 9.
The exhaust hood 5 is provided with a horizontally elongated oblong exhaust pipe 10 on the front surface, penetrates the front cover and projects forward, and is capable of discharging the combustion exhaust gas passing through the heat exchanger 4 to the outside.

  A gas inlet 11 to which an external gas pipe is connected, a water inlet 12 to which a water pipe is connected, and a hot water outlet 13 to which a pipe to a hot water tap is connected are provided on the lower surface of the housing 2. . Of these, the gas inlet 11 is connected to the gas supply unit 6 in the housing 2 via a gas pipe 14 having a main valve, a proportional valve, and the like. The water inlet 12 is connected to the upstream end of the heat transfer pipe 9 of the heat exchanger 4 via the water supply pipe 15, and the hot water outlet 13 is connected to the downstream end of the heat transfer pipe 9 via the hot water discharge pipe 16. .

Then, as shown in FIG. 2, the combustion device 3 includes a burner in which a plurality of flat-shaped light and dark burners 22, 22, ... The unit 21 is assembled.
As shown in FIGS. 3 and 4, the inner case 20 is made of metal (for example, an aluminum-plated steel plate) having a case body 23 having an open upper surface and a front surface, and a front wall 24 assembled to the front surface of the case body 23. The burner unit 21 is fixed to the case main body 23 via front and rear inner plates 25 and support plates 26.
First, the case body 23 is attached to the rear wall portion 30, left and right side wall portions 31 and 31 that are bent from the left and right ends of the rear wall portion 30 to the front side, and the rear wall portion 30 and the side wall portions 31 and 31. And a bottom wall portion 32 that closes the lower surface and an overheat prevention plate 33 attached to the rear wall portion 30.

At the upper end of the rear wall portion 30 and the upper ends of the side wall portions 31, 31, rising portions 34, 34 ... Having an L-shaped cross section are bent upward and formed over the entire length. A plurality of caulking pieces 35, 35, ... Are formed at a predetermined interval at 34.
Further, at the front ends of the side wall portions 31 and 31, fixing pieces 36 and 36 having screw holes for screwing the front wall 24 and the gas supply unit 6 are respectively bent outward.
Further, the bottom wall portion 32 is formed with a through hole 37 to which the air supply fan 7 is connected.

The overheat prevention plate 33 is a horizontally-long rectangular metal plate (for example, a stainless steel plate) that covers the upper portion of the rear wall portion 30. The overheat prevention plate 33 has three circular shapes at equal intervals in the left and right directions at the upper side and the lower side. The boss portions 38, 38, ... And the boss portions 39, 39 .. Here, the upper boss portion 38 has a larger diameter than the lower boss portion 39, and the upper and left boss portions 38, 38 are joined to the rear wall portion 30 by rivets 40, 40. There is.
Therefore, as shown in FIG. 5, the overheat prevention plate 33 is left and right in a state where each boss portion 38, 39 is brought into contact with the inner surface 30a of the rear wall portion 30 to form a gap S between the inner surface 30a and the inner surface 30a. The two rivets 40, 40 suspend and support the rear wall portion 30.
Below the overheat prevention plate 33, a laterally long rectangular bulging portion 41 extending in the left-right direction is provided on the rear wall portion 30 so as to project rearward.

The support plate 26 includes a horizontally-long rectangular back plate portion 42 provided along the inner surface 30a of the rear wall portion 30, and a pair of horizontal plate portions 43, 43 bent forward from both left and right ends of the back plate portion 42. It has a U shape in plan view. A fitting portion 44 of the same shape that fits into the bulging portion 41 from the front is provided on the back plate portion 42 so as to project rearward, and the light and dark burners of the burner unit 21 are provided at the upper and lower edges of the back plate portion 42. A plurality of support pieces 45, 45 engaged with each other are bent forward at equal intervals in the left-right direction. Further, slits 46, 46 ... Are formed downwardly between the support pieces 45 at the upper edge of the back plate portion 42.
The lateral plate portion 43 has a left-right width in which the burner unit 21 can be accommodated, and extends inside the side wall portions 31 and 31 in parallel with the side wall portion 31. However, the intermediate portion is bent outward so that the left and right spaces are widened, and then is bent forward so that the front half portion is in contact with the inner surfaces of the side wall portions 31, 31. At the front ends of the horizontal plate portions 43, 43, mounting pieces 47, 47 having screw holes are bent and formed inward.

  As shown in FIGS. 5 and 6, the support plate 26 is attached to the rear wall portion 30 by the rivets 48, 48 at a position where the fitting portion 44 fits into the bulging portion 41. In this attached state, the upper portion of the support plate 26 overlaps the lower portion of the overheat prevention plate 33 from the front, and the lower portion of the overheat prevention plate 33 is pressed and fixed to the rear wall portion 30 side. At this time, each slit 46 of the support plate 26 extends below the lower end of the overheat prevention plate 33 to communicate with the gap S formed between the inner surface 30a of the rear wall portion 30 and the overheat prevention plate 33. There is.

  Each of the rich and thin burners 22 of the burner unit 21 is opened forward and a lower light side inlet 50 for introducing the fuel gas and the primary air, an upper rich side inlet 51, and the inside thereof is introduced downstream thereof. It has a mixing part 52 which is separated for each mouth, and a flame hole part 53 which is opened at the upper end of the mixing part 52 and is composed of a central light flame hole and rich flame holes on the left and right sides thereof. The entire burner unit 21 has a substantially rectangular parallelepiped shape in a state where the light and shade burners 22 are stacked in the left-right direction.

The inner plate 25 is L-shaped in a side view and has a lower plate portion 60 located below the burner unit 21 and a front plate portion 61 located in front of the burner unit 21, and the lower plate portion 60 has a plurality of members. .. are formed at predetermined intervals in the front, rear, left and right. A screwing piece 63 is bent downward at the front end of the lower plate portion 60, and as shown in FIGS. 4, 5 and 7, the rear wall portion 30 is screwed from the front by two screws 64, 64 on the left and right sides. Will be stopped. Lower bent pieces 65, 65 that come into contact with the inner surfaces of the side wall portions 31, 31 are formed downward at both left and right edges of the lower plate portion 60.
The front plate portion 61 has a plurality of support pieces 66, 66 engaged with the respective dark and light burners 22 of the burner unit 21 and bent backward at equal intervals in the left-right direction at the upper edge of the front plate portion 61. Further, below the support piece 66, there are provided a lower light gas supply hole 67, which is an elliptical burring hole, corresponding to the light side introduction port 50 and the dark side introduction port 51 of each light and dark burner 22. The upper concentrated gas supply holes 68, which are circular burring holes, are arranged side by side in the left-right direction. Further, front bent pieces 69, 69 that contact the inner surfaces of the side wall portions 31, 31 are formed on the left and right sides of the front plate portion 61 so as to face forward, and contact the back surface of the front plate portion 61 inside each of the front bent pieces 69. The left and right mounting pieces 47, 47 of the supporting plate 26 in contact with each other are screwed from the front with screws 70, 70.

The front wall 24 has a horizontally long rectangular shape that covers the upper front half of the case body 23, and a front side overheat prevention plate 75 is riveted to the back surface as shown in FIG. At the upper edge of the front wall 24, a rising portion 76 having an L-shaped cross section is bent upward over the entire length, and the rising portion 76 has a plurality of caulking pieces 77 at predetermined intervals. 77 ... is formed.
Further, in the front wall 24, a mounting hole 79 for a discharge electrode 78 for ignition, a mounting hole 81 for a frame rod 80 as a flame detection electrode, and a through hole 83 for a viewing window 82 are arranged at predetermined intervals in the left-right direction. It is formed with. Here, the discharge electrode 78 and the frame rod 80 project rearward of the front wall 24 through the mounting holes 79 and 81, respectively, and the pressing plate 84 and the front wall 24 are screwed to the front wall 24 from the front. It is attached by sandwiching the respective flanges 78a and 80a between them. The viewing window 82 is also screwed to the front wall 24 from the front.

Here, on the front surface of the front wall 24, as shown in FIGS. 3 and 4, the first bead portion 85 in the left-right direction corresponding to the lower side of the lower right corner of the restraining plate 84 in a front view, and the restraining plate 84. A left and right second bead portion 86 corresponding to the upper side of the upper left corner portion is provided. Further, the first bead portion 85 is integrally formed with a first sub-bead portion 87 in the up-down direction corresponding to the lateral side of the lower right corner of the restraining plate 84.
Similarly, on the front surface of the front wall 24, the third bead portion 88 in the left-right direction corresponding to the lower side of the lower right corner of the viewing window 82 in front view, and on the upper side and the lateral side of the upper left corner of the viewing window 82. A corresponding inverted L-shaped fourth bead portion 89 is provided so as to project.
Therefore, when attaching the discharge electrode 78 and the frame rod 80, the lower right corner of the restraining plate 84 is inside the first bead portion 85 and the first sub-bead portion 87, and the upper left corner is below the second bead portion 86. The restraining plate 84 can be positioned by abutting on each side. If the screwing is performed in this state, the pressing plate 84 is prevented from rotating by the first bead portion 85, the second bead portion 86, and the first sub-bead portion 87, and the screw can be quickly screwed without displacement. The same applies to the observation window 82, and the positioning is performed by the third bead portion 88 and the fourth bead portion 89.
In this way, as shown in FIG. 9, the front wall 24 to which the discharge electrode 78, the frame rod 80, and the viewing window 82 are attached has fixing pieces 36, which are provided on the side wall portions 31, 31 of the case body 23 on the upper sides of the left and right ends. It is screwed from the front to 36 by screws 90, 90.

When assembling the combustion device 3 in the water heater 1 configured as described above, first, the support plate 26 is inserted from the front into the case main body 23 in which the overheat prevention plate 33 is suspended and supported by the rivets 40, 40, and fitted. The part 44 is attached from the front by the rivets 48, 48 at the position where the part 44 is fitted to the bulging part 41 of the rear wall part 30 (first step). However, the support plate 26 may be screwed to the rear wall portion 30 instead of being riveted.
By mounting the support plate 26, the lower portion of the overheat prevention plate 33 is pressed against the rear wall portion 30 from the front by the upper portion of the support plate 26 as described above, and is fixed. In this state, the gap S between the inner surface 30a of the rear wall portion 30 and the overheat prevention plate 33 communicates with the inside of the case body 23 through each slit 46 of the support plate 26, and the air inside the case body 23 has a gap S. Will be able to pass through.

Next, the burner unit 21 is inserted from the front side of the support plate 26 between the lateral plate portions 43, 43, and the upper and lower support pieces 45, 45 of the support plate 26 are provided at the rear portion of the burner unit 21 for the respective density burners 22. They are engaged with each other and supported (second step).
In this state, the inner plate 25 is inserted from the front with the lower plate portion 60 below the burner unit 21, and the screw fastening piece 63 is screwed to the rear wall portion 30 from the front with the screw 64. Further, the support piece 66 at the upper end of the front plate portion 61 is engaged between the respective dark and light burners 22 at the front portion of the burner unit 21, and the light side introduction port 50 and the dark side introduction port 51 of each light and dark burner 22 are connected. The light gas supply hole 67 and the rich gas supply hole 68 are respectively aligned with the position of. After positioning in this manner, the left and right ends of the front plate portion 61 are screwed from the front to the mounting pieces 47, 47 provided on the horizontal plate portions 43, 43 of the support plate 26 with screws 70 (third step).

Then, the front wall 24 to which the discharge electrode 78, the frame rod 80, and the viewing window 82 are attached is applied to the front plate portion 61 from the front, and the left and right ends of the front wall 24 are fixed to the side wall portions 31 and 31 of the case body 23. The pieces 36, 36 are screwed from the front with screws 90 (fourth step).
Then, as shown in FIG. 2, the assembling of the combustion device 3 is completed. In this state, an air supply chamber 27 communicating with the air supply fan 7 is formed between the bottom wall portion 32 of the case body 23 and the lower plate portion 60 of the inner plate 25. The lower plate portion 60 functions as a rectifying plate that rectifies the combustion air supplied upward from the air supply chamber 27 through the small holes 62 and evenly distributes it to each of the density burners 22.
The gas supply unit 6 is screwed from the front to the front surface of the combustion device 3 across the lower part of the front wall 24, the fixing pieces 36, 36, and the bottom wall part 32, and the air supply fan is attached to the lower surface of the combustion device 3. Attach 7. Then, the casing of the heat exchanger 4 having the exhaust hood 5 assembled on the upper side of the inner case 20 is caulked by caulking pieces 35 and 77 provided on the case main body 23 and the front wall 24 to be housed in the housing 2. When the pipes and wirings are attached, the assembly of the water heater 1 is completed as shown in FIG.

Therefore, when the hot water supply plug connected to the pipe of the hot water outlet 13 is opened and water is passed through the equipment, the controller 8 which detects this opens the gas flow path of the gas pipe 14 and the fuel gas from the gas supply unit 6 is discharged. Is supplied, and the air supply fan 7 is operated to supply combustion air. Therefore, the fuel gas supplied from the gas supply unit 6 is supplied from the respective light gas supply holes 67 and the rich gas supply holes 68 to the respective dark and light burners 22 through the respective light side introduction ports 50 and the dark side introduction ports 51 together with the primary air. Supplied. Then, when the discharge electrode 78 is continuously discharged by the controller 8, the air-fuel mixture ejected from the flame hole portion 53 of each density burner 22 burns. The combustion exhaust gas of the burner unit 21 is heat-exchanged with the water passing through the heat transfer pipe 9 of the heat exchanger 4 from the water supply pipe 15, becomes hot water of the set temperature, and is discharged from the hot water discharge pipe 16.
At this time, in the combustion device 3, the air in the inner case 20 is guided to the gap S between the inner surface 30a of the rear wall portion 30 and the overheat prevention plate 33 via the slits 46 of the support plate 26, and thus the inner case is formed. Overheating of the rear wall portion 30 of 20 is prevented.

(Effects of Invention of Mounting Structure of Support Plate and Overheat Prevention Plate)
As described above, according to the water heater 1 of the above-described embodiment, the plurality of bosses that protrude rearward and generate the gap S between the overheat prevention plate 33 and the inner surface 30a in the mounted state at the upper and lower portions of the overheat prevention plate 33. The portions 38 and 39 are formed, and only the upper boss portion 38 is attached to the inner surface 30a, and the support plate 26 is attached to the inner surface 30a at a position where the upper portion thereof overlaps the lower portion of the overheat prevention plate 33 from the front. Since the support plate 26 is used, the overheat prevention plate 33 can be assembled to the inner case 20 with a small number of man-hours and the number of parts, and the cost increase can be reduced. Even if the overheat prevention plate 33 is attached only by the upper boss portion 38, the upper portion of the support plate 26 is fixed to the lower portion of the overheat prevention plate 33 by being overlapped with the front portion from the front, so that the overheat prevention plate 33 is attached to the rear wall portion 30. It is possible to effectively prevent floating or rattling from the front.

In particular, here, a bulging portion 41 projecting rearward is formed in a mounting region of the support plate 26 in the rear wall portion 30, while a bulging portion 41 projecting rearward is formed in the supporting plate 26 at a mounting position. Since the fitting portion 44 for fitting with is formed, the positional deviation of the support plate 26 can be prevented and the overheat prevention plate 33 can be securely fixed.
Further, since a plurality of slits 46 extending downward to a position beyond the overlapping portion with the overheat prevention plate 33 are provided at the upper end of the support plate 26, the support plate 26 presses the overheat prevention plate 33 and The air in the inner case 20 can be appropriately introduced into the gap S between the inner surface 30a of the wall portion 30 and the overheat prevention plate 33.

Incidentally, in the invention relating to the mounting structure of the support plate and the overheat prevention plate, the number and shape of the boss portion provided on the overheat prevention plate, the bulging portion of the rear wall portion and the fitting portion of the support plate are not limited to the above-mentioned embodiment, The boss portion may be appropriately changed, such as an ellipse or a ridge. The overheat prevention plate may be screwed to the rear wall instead of the rivet.
Also, the bulging portion of the rear wall portion and the fitting portion of the support plate may be projected forward rather than backward to position the support plate. The bulging portion and the fitting portion do not have to have the same shape, but may be, for example, a frame shape or a rib that fits the fitting portion inside the bulging portion. The bulge portion and the fitting portion can be omitted.

(Effects related to invention of bead portion of front wall)
As described above, according to the water heater 1 of the above-described embodiment, on the front surface of the front wall 24, the first bead portion 85 that abuts on the lower right side of the press plate 84 in front view and the upper left side of the press plate 84 are abutted. Since the second bead portion 86 that contacts is formed, the discharge electrode 78 and the frame rod 80 can be easily attached without shifting the position of the pressing plate 84.
In particular, here, the first bead portion 85 further includes the first sub-bead portion 87 that abuts on the right lateral side of the pressing plate 84, so that the pressing plate 84 can be positioned more easily and the positional deviation can be prevented. To be the target.

  Further, the caulking pieces 35, 77 are formed on the upper end of the case body 23 and the upper end of the front wall 24, respectively, and when the front wall 24 is attached, the caulking pieces 35, 77 of the case body 23 and the front wall 24 are formed. Since the inner case 20 is arranged at a predetermined interval all around the upper end of the inner case 20, the front wall 24 can be used for caulking and coupling with the casing of the heat exchanger 4, leading to a reduction in manufacturing cost.

In the invention relating to the bead portion of the front wall, the length, width, etc. of each bead portion are not limited to the above-described form, but can be changed as appropriate, for example, the first bead portion and the first sub-bead portion can be provided separately. Good. Also, if there is a space between the restraining plate and the viewing window, the second bead portion can also be provided with a second sub-bead portion that abuts on the left lateral side of the restraining plate. If the second sub-bead portion is provided in this way, the pressing plate can be positioned more easily.
Further, the positions of the discharge electrode and the frame rod are not limited to the above-mentioned form, but can be changed appropriately according to the form of the burner unit. You may arrange in right and left reverse.

(Effects of the invention relating to the water heater and its manufacturing method)
As described above, in the water heater 1 of the above-described embodiment, the inner case 20 is fixed to the case body 23 having the rear wall portion 30 and the left and right side wall portions 31 and the rear wall portion 30 so as to be superposed on the rear wall portion 30 from the front. A support plate 26 in which a support piece 45 (rear side support piece) for supporting the rear end of 21 is formed forward, a lower plate portion 60 located below the burner unit 21, and an upward direction from the front end of the lower plate portion 60. The lower plate 60 includes a plurality of small holes 62 (holes) for rectifying the combustion air supplied from below to the burner unit 21. The front plate 61 extends and is located on the front side of the burner unit 21. Is formed, and the front plate portion 61 is provided with a plurality of light gas feeds that overlap from the front to the light gas introduction ports 50 and the fuel gas introduction ports 51 (introduction ports) of the fuel gas provided in each of the light and dark burners 22 (burners). Hole 67 and concentrated gas supply hole 68 (provided Hole) is formed, and the support plate 66, the burner unit 21, and the inner plate 25 are assembled together with the inner plate 25 in which the support piece 66 (front side support piece) that supports the front end of the burner unit 21 is formed rearward. And a front wall 24 that is assembled to the case body 23 from the front in the state of being included.

Thus, when manufacturing the water heater 1, the first step of inserting the support plate 26 into the case body 23 from the front side and fixing it to the rear wall portion 30, and the rear end by inserting the burner unit 21 into the case body 23 from the front side. The second step of supporting the supporting plate 45 of the supporting plate 26, the inner plate 25 is inserted into the case body 23 from the front, and the lower plate portion 60 is screwed from the front to the rear wall portion 30 below the burner unit 21. At the same time, the front end of the burner unit 21 is supported by the support piece 66 of the front plate portion 61, and the respective light gas supply holes 67 and the rich gas supply holes 68 are located at the respective light side introduction ports 50 and the dark side introduction ports 51 from the front. It can be manufactured by a procedure including a third step of combining and a fourth step of screwing the front wall 24 to the case body 23 from the front.
Therefore, the pre-assembly process of the burner unit 21 can be omitted, and the work process related to the assembly can be reduced. Further, since all the steps can be performed from the front, automatic assembly becomes easy and productivity can be improved.

  In the invention relating to the manufacture of the water heater, the structure of the support plate and the inner plate is not limited to the above-described form, and for example, the horizontal plate portion of the support plate may be locked to the front plate portion of the inner plate without being screwed. Alternatively, the lateral plate portion itself of the support plate may be omitted, and the front plate portion may be locked to the side wall portion of the case body or screwed. The position and number of each screw can be changed as appropriate.

  Then, in common with each invention, the structure of the water heater itself is not limited to the above-mentioned form, but is of a latent heat recovery type having a sub heat exchanger, or an exhaust hood having an exhaust tube protruding upward from the housing. Alternatively, each of the above-mentioned inventions can be applied even if each burner of the burner unit is not a light and dark burner, and one inlet and one supply hole are provided.

  1 ... water heater, 2 ... housing, 3 ... combustion device, 4 ... heat exchanger, 6 ... gas supply unit, 7 ... air supply fan, 8 ... controller, 20 ... inner case, 21 ··· Burner unit, 22 · · Dark and light burner, 23 · · Case body, 24 · · Front wall, 25 · · Inner plate, 26 · · Support plate, 30 · · Rear wall portion, 30a · · Inner surface, 31 ·・ Side wall part, 32 ・ ・ bottom wall part, 33 ・ ・ Overheat prevention plate, 34,76 ・ ・ Starting part, 35,77 ・ ・ Crimping piece, 38,39 ・ ・ Boss part, 41 ・ ・ Swelling part, 42 ... Back plate part, 43 .. Lateral plate part, 44 .. Fitting part, 46 .. Slit, 60 .. Lower plate part, 61 .. Front plate part, 64, 70, 90 .. Screw, 78 ..Discharge electrodes, 80..Frame rods, 84..Holding plate, 85..First bead portion, 86..Second bead portion, 87..Sub-bead , S ·· gap.

Claims (4)

In the housing,
A burner unit in which a plurality of burners are arranged side by side in the left-right direction,
An inner case that houses the burner unit,
It has a discharge electrode for ignition and a flame detection electrode which are attached to the front wall of the inner case and arranged on the left and right,
The discharge electrode and the flame detection electrode are water heaters mounted by a retaining plate screwed to the front surface of the front wall in a state of penetrating a mounting hole provided in the front wall,
On the front surface of the front wall, a first bead portion that abuts on a lower right side of the restraining plate in a front view and a second bead portion that abuts on an upper left side of the restraining plate are formed. Water heater to do.   The water heater according to claim 1, wherein the first bead portion further includes a first sub-bead portion that is in contact with the right lateral side of the pressing plate.   The water heater according to claim 1 or 2, wherein the second bead portion further includes a second sub-bead portion that abuts on the left lateral side of the pressing plate. The inner case has the front wall attached to the front surface of a case body having a rear wall portion and left and right side wall portions,
A plurality of caulking pieces are respectively formed on an upper end of the case body and an upper end of the front wall, and in a mounting state of the front wall, the caulking pieces of the case body and the front wall are The water heater according to any one of claims 1 to 3, wherein the water heater is arranged at a predetermined interval over the entire circumference of the upper end.

Images