JP6931485B2 - Hot water device - Google Patents

Description

The present invention relates to a water heating device such as a hot water supply device.

As a specific example of a hot water device configured as a hot water supply device, a burner that receives combustion air from a fan and a heat exchanger that recovers heat from the combustion gas generated by this burner to heat hot water are provided. I have something to prepare for. Such a hot water device is provided with a combustion chamber case that houses the burner and surrounds the combustion chamber of the burner, and the combustion gas is configured to be guided to the heat exchanger by the combustion chamber case. ing.

In such a hot water device, it is required to appropriately prevent the combustion gas from leaking from the inside of the combustion chamber case or the heat exchanger to the outside. For example, the combustion chamber case is provided with an opening for maintenance such as a burner, and this opening is normally closed by a lid member, but if the airtight sealability of the attachment portion of the lid member is poor, Combustion gas leaks to the outside through the opening. Further, a spark plug and other members are often attached to the combustion chamber case, but if the airtight sealability of the attachment portion is poor, the combustion gas also leaks. Further, conventionally, a configuration in which a burner case as a combustion chamber case and a can body of a heat exchanger formed separately from the burner case are flanged is often adopted, but such a flange connecting portion also burns. It can be a gas leak point.

Therefore, in the past, the airtight sealing property has been improved so that the combustion gas does not leak from the above-mentioned locations, but as a means for that purpose, for example, expensive sealing packing is often used, or the members are screwed. The reality is that measures such as increasing the number of locations are being adopted. This results in poor productivity and high manufacturing costs.

Japanese Patent No. 4544512 Jikkai Sho 62-108752

The present invention has been conceived under the above-mentioned circumstances, and it is possible to appropriately prevent or suppress the leakage of combustion gas to the outside by a simple configuration and reduce the manufacturing cost. The challenge is to provide a water heating device.

In order to solve the above problems, the following technical measures are taken in the present invention.

The water heating device provided by the present invention forms a burner that receives combustion air from a fan, a heat exchanger for heat recovery, and a combustion chamber of the burner inside, and burns generated by the burner. A hot water device comprising a combustion chamber case capable of directing gas to the heat exchanger, further comprising a unit case surrounding the combustion chamber case, within the unit case. Among them, the outer region of the combustion chamber case is an air pressure chamber having a pressure higher than that of the combustion chamber, and the unit case is provided with flange portions on the outer periphery thereof, and these flange portions are in contact with each other. The front part of the unit case and the rear part of the unit case, and the front part of the unit case and the rear part of the unit case, which are connected to each other so as to sandwich the combustion chamber case and the heat exchanger from the front-rear direction by being brought into contact with each other and crimped. The fan and its drive motor are provided with a bottom lid attached to the lower part of the front part of the unit case and the rear part of the unit case so as to close the lower opening formed in the lower part between them. , It is characterized in that it is housed in the unit case in a state of being attached to the bottom lid.

According to such a configuration, the following effects can be obtained.
First, if the outer region of the combustion chamber case in the unit case is an air pressure chamber with a higher pressure than the combustion chamber, the combustion gas in the combustion chamber is transferred to the air pressure chamber based on these pressure differences. Leakage is adequately prevented or curbed. Therefore, when the combustion chamber case is provided with an opening closed by a lid member, or when a spark plug or other parts are attached, even if the airtight sealability of those parts is not so excellent, the combustion gas It is possible to prevent leakage of gas. As a result, according to the present invention, it is possible to eliminate the need to use a large amount of expensive sealing packing and to increase the number of screwed parts of the member, and improve the productivity of the water heating device as compared with the conventional technique. And it is possible to reduce the manufacturing cost.
Secondly, the combustion chamber case and the heat exchanger can be appropriately housed inside the unit case while reducing the number of parts of the unit case and improving the assembling property thereof.
Thirdly, the connection between the front part of the unit case and the rear part of the unit case is facilitated, and the assembly cost of the unit case can be reduced. Further, even if there is a portion where the sealing property is not sufficient in the crimped portion between the flange portions, if the inside thereof is an air pressure chamber, there should be no combustion gas in this inner portion. , Combustion gas does not leak to the outside of the unit case from the above-mentioned location. Therefore, even if the caulking means is adopted as the connecting means between the front part of the unit case and the rear part of the unit case, it can be appropriately avoided that this causes the leakage of the combustion gas.
Fourth, the drive noise emitted from the fan and its drive motor can be blocked by the unit case, and a noise reduction effect can be obtained.

In the present invention, preferably, the air pressure chamber extends to the outer region of the heat exchanger in the unit case, and the air pressure chamber is larger than the inner region of the heat exchanger. High pressure.

With such a configuration, it is possible to appropriately prevent the combustion gas in the heat exchanger from unreasonably leaking into the air pressure chamber. Therefore, it is possible to preferably simplify the seal structure for preventing the combustion gas from leaking from the heat exchanger, and further improve the productivity and reduce the manufacturing cost.

In the present invention, preferably, a part of the combustion air discharged from the fan is supplied to the installation area of the burner in the combustion chamber case, and a part of the other part is supplied to the air pressure chamber. It is configured to.

According to such a configuration, by supplying a part of the combustion air discharged from the fan to the air pressure chamber, the air pressure chamber can be made higher pressure than the inside of the combustion chamber or the heat exchanger. be. Therefore, it is possible to eliminate the need to provide a dedicated fan for increasing the pressure of the air pressure chamber separately from the fan. Even when the air discharged from one fan is distributed and supplied to the combustion chamber side and the air pressure chamber side, the resistance of the air flow on the air pressure chamber side is smaller than that on the combustion chamber side. For example, the pressure on the air pressure chamber side is higher than that on the combustion chamber side.

In the present invention, preferably, at least one of the water inlet pipe body portion and the hot water outlet pipe body portion of the heat exchanger is sandwiched between the mating surfaces of the front part of the unit case and the rear part of the unit case. It is pulled out from the inside of the.

According to such a configuration, the assembling work for pulling out the water inlet pipe body portion or the hot water outlet pipe body portion of the heat exchanger from the inside of the unit case to the outside becomes easy. It is not necessary to separately provide a hole dedicated to pulling out the tube body in the unit case.

In the present invention, preferably, a first opening is provided on the front surface of the combustion chamber case, and the first opening can be closed by the front lid of the combustion chamber. A second opening is provided on the front surface of the unit, and the second opening can be closed by the front lid of the unit case, and the first and second openings are opened. In the above, the burner can be taken in and out of the combustion chamber case from the outside of the unit case.

According to such a configuration, it is convenient for performing maintenance work of the burner and the like.

In the present invention, preferably, the fan and its drive motor are housed in the unit case so as to be located below the burner, and the height is closer to the first and second openings. It is provided in a sloping posture in a downward-sloping manner so that the height is low.

According to such a configuration, as will be described later with reference to FIG. 9, a fan and its drive motor and the like can be inserted by inserting a tool into the unit case and the combustion chamber case through the first and second openings. When performing maintenance work, the work becomes easier and more convenient.

In the present invention, preferably, a fuel gas ejection head for supplying fuel gas to the burner is arranged in the unit case so as to be located on the front side of the burner, and is arranged on the front side of the fuel gas ejection head. The region is a part of the air pressure chamber.

According to such a configuration, it is possible to more reliably prevent the fuel gas ejected from the fuel gas ejection head from unreasonably advancing to the front region of the fuel gas ejection head.

In the present invention, preferably, an upward opening concave portion capable of fitting and holding the heat transfer tube of the heat exchanger is provided in the upper part of the combustion chamber case.

According to such a configuration, the heat exchanger can be supported on the upper part of the combustion chamber case by fitting and holding the heat transfer tube in the concave portion described above, and the mounting structure of the heat exchanger can be simplified and mounted. The work is facilitated.

In the present invention, preferably, a secondary heat exchanger for heating hot and cold water, which is configured separately from the heat exchanger, is further provided so that the heat exchanger becomes a primary heat exchanger. In the upper part of the unit case, a narrow portion having a smaller front-rear width than the other parts of the unit case and a front side or a rear side of the lower portion of the narrow portion are continuously provided and the secondary heat exchange is performed. A shelf-shaped wall portion on which the vessel is mounted is provided, and an exhaust port is provided on the front wall portion or the rear wall portion of the narrow portion, and the heat exchange proceeds upward from the burner. The combustion gas that has passed through the vessel is configured to be supplied to the secondary heat exchanger through the exhaust port.

According to such a configuration, it is possible to improve the heat exchange efficiency by using the secondary heat exchanger, and also to guide the combustion gas that has passed through the primary heat exchanger to the secondary heat exchanger. It is not necessary to use a member dedicated to the method (a member called an exhaust collecting cylinder).

In the present invention, preferably, a thermal fuse for detecting an abnormal temperature rise is provided in the air pressure chamber.

According to such a configuration, the safety of the hot water device can be enhanced by using the thermal fuse, but since the thermal fuse is provided in the air pressure chamber, a so-called hole is formed in the combustion chamber case or the heat exchanger. When a phenomenon occurs in which high-temperature combustion gas flows into the air pressure chamber (a state in which the combustion gas can be prevented from leaking due to the pressure in the air pressure chamber) occurs, this phenomenon is appropriately caused by the thermal fuse. It is possible to detect it. It is not necessary to use a long-sized thermal fuse, and it is possible to reduce the size and cost (conventionally, for example, a long-sized thermal fuse is wound around a heat exchanger. Was).

In the present invention, preferably, an air passage for letting air in the air pressure chamber flow out to a portion different from the air pressure chamber is provided so that an air flow is generated at a portion where the thermal fuse is provided. ..

According to such a configuration, it is possible to prevent the temperature of the place where the thermal fuse is provided from rising abnormally due to the retention of air in the air pressure chamber, and to stabilize the operation of the thermal fuse. Can be done.

Other features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings.

It is an external perspective view which shows an example of the hot water apparatus which concerns on this invention. It is a side sectional view of the hot water apparatus shown in FIG. It is an exploded sectional view of FIG. It is an exploded perspective view of the hot water apparatus shown in FIG. It is an enlarged perspective view which shows a part of the component shown in FIG. FIG. 3 is a perspective view of a main part showing a configuration related to a primary heat exchanger of the water heating device shown in FIG. FIG. 6 is an exploded perspective view of FIG. (A) is a cross-sectional view of VIIIa-VIIIa of FIG. 7, (b) is a cross-sectional view of VIIIb-VIIIb of (a), and (c) is a cross-sectional view of VIIIc-VIIIc of (a). It is sectional drawing which shows the other example of this invention.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

The water heating device WH shown in FIG. 1 is configured as a hot water supply device, and as shown in FIGS. 2 to 4, a burner unit BU (burner set) and a combustion chamber case 2 in which a plurality of burners 1 are held side by side. A fuel gas ejection head 3, a fan 4, a drive motor M thereof, a primary heat exchanger HE1, a secondary heat exchanger HE2, a unit case 5, and a thermal fuse F (omitted in FIG. 4) are provided.
An air pressure chamber 59, which will be described later, is provided in the outer region of the combustion chamber case 2 and the primary heat exchanger HE1 in the inner region of the unit case 5. The primary heat exchanger HE1 corresponds to an example of the "heat exchanger" in the present invention.

The plurality of burners 1 are gas burners, and as shown in FIG. 5, have a flat shape as a whole, a gas introduction port 10 is provided at the front end, and the gas introduction port 10 is inside together with combustion air. It is possible to burn the introduced fuel gas in the flame hole surface 11 on the upper surface. The burner unit BU is formed by arranging a plurality of burners 1 on a straightening vane 6 and placing and holding them. The straightening vane 6 has a plurality of ventilation holes 60 for allowing the combustion air supplied from the fan 4 to pass upward toward the combustion chamber 29 (see FIG. 2). It is possible to introduce the fuel gas injected from the nozzle 30 of the fuel gas ejection head 3 into the gas introduction port 10 of each burner 1 in the front side upright wall portion 61 provided upright in the front portion of the straightening vane 6. A hole 62 is provided. The fuel gas ejection head 3 is assembled to the burner unit BU by fastening the upper portion of the back plate portion 31 to the front standing wall portion 61 using screws 97a. The front region (left region in FIG. 2) of the back plate portion 31 is a part of the air pressure chamber 59 described later.

In FIG. 4, the combustion chamber case 2 has a configuration in which the front wall portion 22 is joined to the front upper portion of the plan-view U-shaped frame portion 20 having an open front surface. The lower part is the first opening 21. The first opening 21 can be closed by the combustion chamber front lid 2A. As is well shown in FIGS. 2 and 5, the combustion chamber front lid 2A is attached to the front standing wall portion 61 of the burner unit BU via a screw 97b, and the burner unit BU is installed in the combustion chamber case 2. The first opening 21 is closed by the combustion chamber front lid 2A. A spark plug 65 and a flame rod 66 for detecting a flame are attached to the front lid 2A of the combustion chamber in a state of being penetrated. In FIG. 4, a pair of substantially horizontal bending support pieces 23 extending in the front-rear direction are provided below the left and right side wall portions 20a of the combustion chamber case 2 (see also FIGS. 6 and 7). It is possible to mount the burner unit BU on the pair of bending support pieces 23.

As shown in FIGS. 6 and 7, the primary heat exchanger HE1 includes a meandering heat transfer tube 7 and a plurality of plate-shaped fins 8 joined to the heat transfer tube 7 (FIG. 6 shows). , Fin 8 is partially omitted). The plurality of fins 8 are arranged at predetermined intervals in the longitudinal direction of the straight tube body portion 70 of the heat transfer tube 7.

A plurality of concave portions 24 opened upward are provided on the upper portion of the combustion chamber case 2. On the other hand, in the heat transfer tube 7, the bases of the bend tube 71 projecting to the outside of the fins 8 (8a) at both ends and the hot water discharge tube body portion 72b are fitted into the concave portion 24. As a result, the primary heat exchanger HE1 is supported on the upper part of the combustion chamber case 2. The lower region of the fins 8 (8a) at both ends and the left and right side wall portions 20a of the combustion chamber case 2 are in contact with each other so as not to form a gap between them as much as possible.

In the present embodiment, the fin 8 is configured by combining the first and second fin plates 8a and 8b divided via the secant PL. According to such a configuration, since the fins 8 can be attached so as to sandwich the heat transfer tube 7 between the first and second fin plates 8a and 8b, the work of assembling the fin 8 to the heat transfer tube 7 is facilitated. NS.

Each fin 8 has a substantially L-shape in side view so as to correspond to the shape of the upper part of the unit case 5. More specifically, as shown in FIG. 2, the upper portion of the unit case 5 has a front-rear width wider than that of the lower portion of the unit case 5 as a means for simply and rationally connecting the secondary heat exchanger HE2. It includes a narrowed narrow portion 50, an exhaust port 56 provided in the front wall portion 50a thereof, and a shelf-shaped wall portion 50b connected to the lower portion of the front wall portion 50a. A secondary heat exchanger HE2 is mounted on the shelf-shaped wall portion 50b, and the combustion gas that has passed through the primary heat exchanger HE1 is sent into the secondary heat exchanger HE2 from the exhaust port 56. Each fin 8 has a substantially L-shape whose side view shape is described above so that the upper portion is located in the narrow portion 50 and the other portion is along the lower surface of the shelf-shaped wall portion 50b. A plurality of straight tube body portions 70 of the heat transfer tube 7 are also provided in a corresponding arrangement.

Each fin 8 includes bent piece portions 81a and 81b that are bent substantially horizontally. The bent piece portions 81a and 81b are portions for efficiently guiding the combustion gas traveling from below toward the primary heat exchanger HE1 to the exhaust port 56, and one of the bent piece portions 81a is a fin. It is provided on the upper edge of the front portion of No. 8. The other bent piece portion 81b is provided in a series from the upper edge portion to the rear side edge portion of the rear portion of the fin 8. The portion of the fin 8 facing the exhaust port 56 is not provided with the bent piece portion as described above.

As is often shown in FIGS. 7 and 8, the bent pieces 81a adjacent to each other and the bent pieces 81b are in contact with each other so as not to form a gap between them (however, they will be described later). Except for the location where the opening 58 is formed as an air passage. According to such a configuration, the combustion gas traveling from below toward the primary heat exchanger HE1 enters the gap between the fins 8 and then collides with the bent pieces 81a and 81b. , It is prevented from passing upward as it is between the fins 8. The combustion gas is smoothly guided to the exhaust port 56 by the bent pieces 81a and 81b. Therefore, in the present embodiment, a dedicated member for guiding the combustion gas that has passed through the primary heat exchanger HE1 to the secondary heat exchanger HE2 is not used.
In FIG. 8B, reference numeral 82 is a burring portion set to be fitted on the heat transfer tube 7 (in other drawings, the burring portion 82 is simplified or omitted).
As shown in FIG. 2, the upper ends of the front wall portion 22 and the rear wall portion 20b of the combustion chamber case 2 are in contact with the bent piece portions 81a and 81b of the fin 8, and the combustion gas does not leak from these portions. Is being done.

The secondary heat exchanger HE2 is for latent heat recovery, and has a configuration in which a heat transfer tube 91 is housed in a case 90. The combustion gas that has passed through the exhaust port 56 of the unit case 5 travels into the case 90, and after the latent heat is recovered by the heat transfer tube 91, it is exhausted to the outside from the exhaust port 92. The hot water outlet tube of the secondary heat exchanger HE2 is connected to the water inlet tube 72a of the primary heat exchanger HE1, and the hot water heated by the secondary heat exchanger HE2 exchanges the primary heat. It is designed to be sent to the heat transfer tube 7 of the vessel HE1.

The unit case 5 is a case that encloses the entire combustion chamber case 2 and the primary heat exchanger HE1. As shown in FIG. 4, the unit case front portion 5a and the unit case rear portion 5b (hereinafter, “unit case front portion”). It is abbreviated as "5a and rear 5b" as appropriate). The front portion 5a of the unit case has a rear surface portion and a lower surface portion having an open shape having a flange portion 53a continuously formed on the upper portion and both left and right side portions and a bulging portion 54a bulging forward from the flange portion 53a. It is a member. The unit case rear portion 5b is a member having an open front portion and a lower surface portion having a flange portion 53b formed continuously on the upper portion and both left and right side portions and a bulging portion 54b protruding rearward from the flange portion 53b. Is. The front portion 5a and the rear portion 5b of the unit case are assembled so as to sandwich the combustion chamber case 2 and the primary heat exchanger HE1 from the front-rear direction thereof.

The front portion 5a and the rear portion 5b of the unit case are assembled by abutting and crimping the flange portions 53a and 53b as mating surfaces. In this caulking, as shown in the enlarged view of the main part of FIG. 2, for example, the folded piece portion 53c is extended to one of the flange portions 53a and 53b, and the folded piece portion 53c and the flange portions 53a and 53b It is a structure that sandwiches the other with one. According to such a configuration, it is not necessary to screw a large number of parts of the front part 5a and the rear part 5b of the unit case.

In FIG. 4, the flange portions 53a and 53b are provided with a pair of concave portions 55a and 55b facing each other. When joining the flange portions 53a and 53b, the water inlet pipe portion 72a of the primary heat exchanger HE1 is arranged in the opening formed by combining the pair of concave portions 55a and 55b described above. The water entry pipe body portion 72a is set to be sandwiched from both the front and rear sides by the inner surface portions of the pair of concave portions 55a and 55b. As a result, the water entry pipe body portion 72a can be pulled out from the inside of the unit case 5 to the outside while preventing a gap from being formed between the water entry pipe body portion 72a and the unit case 5. As will be described later, the hot water discharge pipe body portion 72b is pulled out from the inside of the unit case 5 to the lower side thereof.

A second opening 52 is provided on the front wall of the unit case 5, and the second opening 52 can be closed by the unit case front lid 5A. As shown in FIG. 2, the unit case front lid 5A is attached to the front wall portion of the unit case 5 via a screw 97c, and a rectangular frame-shaped member is used as a means for ensuring the sealing property of the attachment portion. 48 is intervened. Further, a packing 47 for ensuring the sealing property of the attachment points of the spark plug 65 and the frame rod 66 is also used.

As shown in FIG. 3, the second opening 52 has a size that allows the burner unit BU to be taken in and out of the unit case 5. Preferably, the size is such that the combustion chamber front lid 2A can be taken in and out of the unit case 5 while being attached to the burner unit BU. When the second opening 52 is closed by using the unit case front lid 5A, the unit case 5 has an internal portion except for the exhaust port 56 described above and the air supply port 57 for a fan described later. It is configured to be airtight.

The fan 4 and the drive motor M are assembled on the upper surface side of the bottom lid 5B of the unit case 5, are housed in the unit case 5, and are located below the burner unit BU. The bottom lid 5B is attached to the unit case 5 by using a screw (not shown) or the like so as to close the lower opening of the unit case 5, and has an air supply port 57 communicating with the intake port of the fan 4. .. Preferably, the bottom lid 5B is made of a relatively thick metal such as an aluminum die-cast product. According to such a configuration, the cooling effect of the drive motor M and the effect of suppressing noise and vibration during driving of the fan 4 can be made excellent.

When attaching the bottom lid 5B, a sealing packing 46 as shown in FIG. 5 is preferably used. The sealing packing 46 and the bottom lid 5B are provided with first concave portions 46a and 51a and second concave portions 46b and 51b. The first concave portions 46a and 51a are portions for pulling out the hot water discharge pipe body portion 72b of the primary heat exchanger HE1 from the inside of the unit case 5 to the lower outside thereof. The second concave portions 46b and 51b are portions for arranging the fuel gas supply portion 35 connected to the fuel gas ejection head 3. As shown in FIG. 4, the unit case front portion 5a is provided with a third concave portion 51c, and the fuel gas supply portion 35 is also arranged in the third concave portion 51c.

In FIG. 2, the fan 4 blows air around the impeller, and an opening 44 for blowing air using a partition plate 45 is provided on the upper side of the fan 4, and is discharged from the fan 4. The air to be generated passes through the opening 44 upward. This air is used as the primary air for combustion that advances to the gas inlet 10 of the burner 1, and as the secondary air that passes through the ventilation holes 60 and advances to the installation area of the burner 1, and also as a unit. In the case 5, it is configured to proceed to the outer region of the combustion chamber case 2 and the primary heat exchanger HE1.

The outer region described above is an air pressure chamber 59, the pressure P3 of which is higher than the pressure P1 of the combustion chamber 29 and the pressure P2 (pressure in the gap between the fins 8) in the primary heat exchanger HE1. High pressure. The pressures P1 and P2 in the combustion chamber 29 and the primary heat exchanger HE1 have a large air flow path resistance due to the ventilation holes 60 and the burner 1, so that although air is supplied from the common fan 4, the pressures P1 and P2 are described above. It is possible to generate such a pressure difference.

The thermal fuse F is provided in the air pressure chamber 59, and is preferably provided in the upper part of the air pressure chamber 59. The thermal fuse F is configured to cause disconnection when the temperature rises abnormally and becomes a predetermined temperature or higher. At the time of disconnection, for example, the main solenoid valve of the fuel gas piping system is set to be closed. In the present embodiment, an opening 58 is provided as an air passage for generating an air flow at a location where the thermal fuse F is provided. The opening 58 is provided, for example, by omitting a part of the bent piece portion 81b of the fin 8 of the primary heat exchanger HE1. According to such a configuration, the air in the air pressure chamber 59 passes through the opening 58 and flows between the fins 8 and then proceeds into the exhaust port 56 and the secondary heat exchanger HE2. As a result, air does not stay at the installation location of the thermal fuse F, which is more preferable in stabilizing the operation of the thermal fuse F and increasing the reliability of the abnormal temperature rise detection performance.

Next, the operation of the above-mentioned hot water device WH will be described.

First, the pressures P1 and P2 in the combustion chamber 29 and the primary heat exchanger HE1 and the pressure P3 in the air pressure chamber 59 as the outer region thereof have a relationship of P3> P1, P3> P2. Therefore, the combustion gas in the combustion chamber 29 and the primary heat exchanger HE1 is appropriately prevented or suppressed from leaking to the air pressure chamber 59. As a result, the combustion gas can be used in the combustion chamber 29 and the primary heat exchanger without making the airtight sealability of each part of the combustion chamber case 2 and the primary heat exchanger HE1 and the attachment points with other members so excellent. It is possible to prevent leakage to the outside of HE1.

Specific examples include a contact point between the combustion chamber case 2 and the combustion chamber front lid 2A, a contact point between the combustion chamber case 2 and the fin 8 of the primary heat exchanger HE1, and the bent piece portions 81a of the fin 8. For the contact points, the contact points between the bent pieces 81b, the spark plug 65, the attachment points of the frame rod 66 for flame detection, etc., expensive sealing packings may be used, or members that come into contact with each other may be used. It is possible to tighten dimensional control and eliminate the need to assemble the members with high precision so that high airtight sealability can be obtained. As a result, it is possible to increase the overall productivity of the water heating device WH and reduce the manufacturing cost thereof.

Since the front region of the fuel gas ejection head 3 (the side opposite to the nozzle 30) is a part of the air pressure chamber 59, the fuel gas ejected from the fuel gas ejection head 3 is the fuel gas ejection head 3. Unreasonable progress to the anterior region is also properly prevented.

As described above, the unit case 5 is a combination of the front portion 5a and the rear portion 5b of the unit case, and its configuration is simple. Further, as the means for assembling them, since the means for crimping the flange portions 53a and 53b, which are connected to each other in a series, are brought into opposite contact with each other and then crimped, a large number of these flanges are screwed. Compared with such means, its productivity is also good. Therefore, it is more preferable in terms of reducing the manufacturing cost. The inner region of the crimped portion of the flange portions 53a and 53b is the air pressure chamber 59, which is a region where the combustion gas does not exist. Even so, the combustion gas does not leak to the outside from this part.

As shown in FIG. 3, when the unit case front lid 5A is removed and the second opening 52 is opened, the burner unit BU can be taken out in front of the unit case 5. Therefore, maintenance work of the burner unit BU is also easy. Further, in a state where the burner unit BU is taken out to the outside, maintenance work of the fan 4 and the drive motor M can be performed through the first and second openings 21 and 52. Since the fan 4 and the drive motor M are housed in the unit case 5, the drive noise generated from them can be blocked by the unit case 5 to obtain a noise reduction effect.

In addition, according to the present embodiment, the structure for assembling the primary heat exchanger HE1 to the combustion chamber case 2 is simple, and the combustion gas that has passed through the primary heat exchanger HE1 is guided to the secondary heat exchanger HE2. Since no special parts are required for this purpose, it is possible to further promote the reduction of the overall manufacturing cost of the water heater WH. Further, according to the present embodiment, it is possible to accurately detect an abnormal temperature rise due to so-called perforation or the like while reducing the size of the thermal fuse F and reducing the cost of its parts, which is safe. Can also be excellent.

FIG. 9 shows another embodiment of the present invention. In the figure, elements that are the same as or similar to those of the embodiment are designated by the same reference numerals as those of the embodiment, and duplicate description thereof will be omitted.

In the embodiment shown in FIG. 9, the fan 4 and the drive motor M are provided in a forward-down inclined posture. This configuration is configured by the upper surface of the bottom lid 5B to which the fan 4 and the drive motor M are attached is inclined in a downward-sloping manner.

According to the present embodiment, the attachment points of the fan 4 and the drive motor M can be easily seen from the outside through the first and second openings 21 and 52. Further, when the tool 98 such as a screwdriver is inserted into the mounting position of the fan 4 or the drive motor M, it is not necessary to raise the driver in the vertical direction. Therefore, for example, the grip portion of the tool 98 is placed outside the unit case 5. It is also possible to perform maintenance work while keeping it in the position. When the entire tool 98 is allowed to enter the unit case 5 and the tool 98 is raised in the vertical direction, the upper end of the tool 98 may interfere with the primary heat exchanger HE1. Then, it is possible to eliminate or reduce such a risk and improve workability.

The present invention is not limited to the contents of the above-described embodiments. The specific configuration of each part of the water heating device according to the present invention can be variously redesigned within the scope intended by the present invention.

In the above-described embodiment, the heat transfer tube of the heat exchanger (primary heat exchanger) is directly held in the combustion chamber case, but the present invention is not limited to this. For example, the heat exchanger may have a structure in which a heat transfer tube is housed in a frame-shaped can body, and the can body and the combustion chamber case may be connected to each other. The specific configuration of the heat exchanger is not limited.
In the present invention, the configuration may be such that the secondary heat exchanger is not provided.

It is desirable that the air pressure chamber is provided in the outer region of the heat exchanger in addition to the outer region of the combustion chamber case as in the above-described embodiment, but instead, only in the outer region of the combustion chamber case. It is also possible to have a configuration in which an air pressure chamber is provided. Even with such a configuration, the effect of preventing leakage of combustion gas can be obtained as compared with the prior art.

The shape of unit case, as in the embodiment described above is not limited to the shape in which the width in the upper narrow portion is provided, it may be shaped without such narrow portion. The exhaust port of the unit case can be provided, for example, on the rear wall portion instead of being provided on the front wall portion of the unit case . Type of fan is not limited.

The water heating device according to the present invention is not limited to the hot water supply device, and can be configured as, for example, a heating water heating device, a snow melting water heating device, or the like. Further, the present invention is also applicable to a reverse combustion type water heating device in which the combustion gas generated by the burner is advanced downward and supplied to a heat exchanger located below the burner.

WH hot water device HE1 primary heat exchanger (heat exchanger)
F Temperature fuse M Drive motor (of fan)
1 Burner 2 Combustion chamber case 2A Combustion chamber front lid 21 First opening 24 Concave part 29 Combustion chamber 3 Fuel gas ejection head 4 Fan 5 Unit case 5A Unit case front lid 5a Unit case front 5b Unit case rear 50 Narrow Part 52 Second opening 53a, 53b Flange part 58 Opening (air passage)
59 Air pressure chamber 72a Water inlet pipe body 72b Hot water discharge pipe body

Claims (11)

A burner that receives combustion air from a fan and
A heat exchanger for heat recovery and
A combustion chamber case in which the combustion chamber of the burner is formed inside and the combustion gas generated by the burner can be guided to the heat exchanger.
It is a water heating device equipped with
A unit case surrounding the combustion chamber case is further provided.
In this unit case, the outer region of the combustion chamber case is an air pressure chamber having a higher pressure than the combustion chamber .
The unit case is
A unit case in which the combustion chamber case and the heat exchanger are sandwiched from the front-rear direction by providing flange portions on the outer periphery thereof and crimping the flange portions in contact with each other. With the front and rear of the unit case,
A bottom lid attached to the front part of the unit case and the lower part of the rear part of the unit case so as to close the lower opening formed in the lower part between the front part of the unit case and the rear part of the unit case.
Is equipped with
A water heating device, wherein the fan and its drive motor are housed in the unit case in a state of being attached to the bottom lid. The water heating device according to claim 1.
A water heating device in which the air pressure chamber extends to the outer region of the heat exchanger in the unit case, and the air pressure chamber has a higher pressure than the inner region of the heat exchanger. The water heating device according to claim 1 or 2.
A part of the combustion air discharged from the fan is supplied to the installation area of the burner in the combustion chamber case, and a part of the other part is supplied to the air pressure chamber. , Hot water device. The water heating device according to any one of claims 1 to 3.
At least one of the water inlet pipe body portion and the hot water discharge pipe body portion of the heat exchanger is pulled out from the inside of the unit case so as to be sandwiched between the mating surfaces of the front part of the unit case and the rear part of the unit case. A hot water device. The water heating device according to any one of claims 1 to 4.
A first opening is provided on the front surface of the combustion chamber case, and the first opening can be closed by the front lid of the combustion chamber.
A second opening is provided on the front surface of the unit case, and the second opening can be closed by the front lid of the unit case.
A water heating device in which the burner can be taken in and out of the combustion chamber case from the outside of the unit case in a state where the first and second openings are opened . The water heating device according to claim 5.
The fan and its drive motor are housed in the unit case so as to be located below the burner, and are lowered forward so that the portion closer to the first and second openings is lower in height. A water heating device installed in a slanted posture. The water heating device according to any one of claims 1 to 6.
A fuel gas ejection head for supplying fuel gas to the burner is arranged in the unit case so as to be located on the front side of the burner, and the front region of the fuel gas ejection head is the air pressure chamber. A water heater that is said to be part of. The water heating device according to any one of claims 1 to 7.
A water heating device provided with an upward-opening concave portion capable of fitting and holding a heat transfer tube of the heat exchanger in the upper part of the combustion chamber case . The water heating device according to any one of claims 1 to 8.
A secondary heat exchanger for heating hot and cold water, which is configured separately from the heat exchanger, is further provided so that the heat exchanger becomes a primary heat exchanger.
In the upper part of the unit case, a narrow portion having a smaller front-rear width than the other parts of the unit case and a front side or a rear side of the lower portion of the narrow portion are continuously provided and the secondary heat exchange is performed. There is a shelf-shaped wall on which the vessel is placed, and
An exhaust port is provided in the front wall portion or the rear wall portion of the narrow portion, and the combustion gas traveling upward from the burner and passing through the heat exchanger is subjected to the secondary heat through the exhaust port. A water heater that is configured to be supplied to the exchanger. The water heating device according to any one of claims 1 to 9.
A water heating device in which a thermal fuse for detecting an abnormal temperature rise is provided in the air pressure chamber. The water heating device according to claim 10.
A water heating device provided with an air passage for allowing air in the air pressure chamber to flow out to a portion different from the air pressure chamber so that an air flow is generated at a location where the thermal fuse is provided.

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