JP7296615B2 - Water heater - Google Patents

Description

The present invention relates to a water heater.

2. Description of the Related Art Conventionally, there is known a water heater having an exhaust portion on the top of a housing (see, for example, Patent Document 1). The exhaust part is fixed to the upper side of the casing of the heat exchanger and includes a cover-like exhaust casing with an open front, an exhaust pipe fixed to the front end of the exhaust casing and having an exhaust outlet at the front, and an exhaust casing. and a rectifying plate provided inside. The exhaust casing protrudes upward at the rear portion and has an upper surface shape that slopes downward toward the front. The rectifying plate includes a lower plate portion that is upwardly inclined rearward, a folded portion that is folded upward from the lower plate portion, and an upper plate portion that extends forward from the folded portion. After passing through the heat exchanger, the combustion exhaust gas flows into the exhaust casing, is guided rearward and obliquely upward by the lower plate portion of the current plate, is guided upward by the folded portion, and is further guided forward by the upper plate portion. and discharged to the outside from the exhaust outlet of the exhaust stack.

JP 2018-31489 A

In the exhaust casing, the combustion exhaust after flowing along the upper plate portion from the folded portion of the rectifying plate is guided obliquely downward by the downwardly inclined upper surface shape of the exhaust casing. may be added. As a result, the combustion exhaust is discharged obliquely downward at the exhaust outlet, which may give discomfort to a person below the exhaust outlet.

SUMMARY OF THE INVENTION An object of the present invention is to provide a water heater capable of preventing combustion exhaust from being discharged obliquely downward from an exhaust outlet.

The water heater according to claim 1 is provided above a heat exchanger that heats flowing water by heat of combustion exhaust from a burner, and a front portion protrudes forward from the heat exchanger, and the heat exchanger is positioned upward. an exhaust casing provided in the front portion with an opening for discharging the passing combustion exhaust to the outside, protruding upward in the rear portion and having an upper surface shape that slopes downward toward the front; an exhaust pipe that protrudes and has a horizontally long rectangular exhaust outlet that is longer in the horizontal direction than in the vertical direction at the front, and that exhausts the combustion exhaust discharged from the opening to the outside from the exhaust outlet; and is supported in the exhaust casing. and a rectifying plate for rectifying the combustion exhaust that has passed upward through the heat exchanger toward the opening, wherein a rear end portion side of the exhaust pipe is provided at an upper inside portion of the exhaust pipe. a V-shaped inclined plate in a side view that slopes downward toward the front end portion side, bends obliquely upward in the middle, and slopes upward toward the upper edge portion side of the exhaust outlet ; Of these, the downwardly inclined portion, which is the downwardly inclined portion, reduces the passage cross-sectional area of the exhaust passage through which the combustion exhaust flows in the exhaust pipe, and the upwardly inclined portion, which is the upwardly inclined portion, reduces the passage cross-sectional area. It is characterized by forming a venturi effect in the exhaust stack due to the enlargement .

The peripheral edge of the exhaust outlet of the water heater of claim 2 is provided with a folded portion that is folded back so as to wind inward, and the rear end portion of the inclined plate is fixed to the front portion of the exhaust casing. It is preferable that a locking portion that can be locked from behind with respect to the folded portion provided on the upper edge portion is provided at the front end portion of the inclined plate.

The periphery of the exhaust outlet of the hot water heater of claim 3 is provided with a folded portion that is folded back so as to wind inward, and the folded portion is provided from the upstream side to the downstream side in the direction in which the combustion exhaust flows. It is preferable to provide an inclined surface that is inclined so as to decrease in diameter as it goes.

According to the water heater of claim 1, the combustion exhaust that has passed upward through the heat exchanger and flowed into the exhaust casing is rectified by the rectifying plate toward the opening of the exhaust casing. Since the combustion exhaust is guided obliquely downward by the downwardly sloping upper surface shape of the exhaust casing, there is a possibility that the combustion exhaust will be given downward momentum. Therefore, in the exhaust pipe, the passage cross-sectional area of the exhaust passage in the exhaust pipe is temporarily reduced by the downwardly inclined portion of the inclined plate, and is expanded at once by the upwardly inclined portion. Thereby, a venturi effect can be produced in the exhaust stack. When the passing cross-sectional area is reduced by the downwardly inclined portion due to the venturi effect, the flow velocity of the combustion exhaust increases in the area near the curved portion of the inclined plate and above the exhaust passage. In this region, the combustion exhaust pressure is low. That is, by providing an inclined plate in the upper part of the exhaust pipe, the combustion exhaust flowing in the upper part of the exhaust passage in the exhaust pipe can be guided obliquely downward. In the upper region, the flue gas velocity can be increased and the pressure can be reduced. As a result, the combustion exhaust that has flowed into the exhaust pipe from the exhaust casing is attracted to and passes through a region of low pressure, so that the downward force disappears and is pushed obliquely upward and discharged to the outside. Therefore, it is possible to prevent combustion exhaust from being discharged obliquely downward from the exhaust outlet, so that it is possible to prevent a person below the exhaust outlet from feeling uncomfortable.

According to the water heater of claim 2, the locking portion provided at the front end portion of the inclined plate is locked from behind with respect to the folded portion provided at the peripheral edge portion of the exhaust outlet, whereby the inclined plate is exhausted. It can be easily and stably held on the upper side of the cylinder. Since it can be easily attached to a water heater having a conventional structure, the cost for attachment is not required.

According to the water heater of claim 3, in the inside of the exhaust pipe, of the combustion exhaust that has passed through the area with the smallest passage cross-sectional area due to the downwardly inclined portion of the inclined plate, the combustion that passes near the lower edge of the exhaust outlet The exhaust is guided obliquely upward by the inclined surface of the folded portion of the lower edge of the exhaust outlet. As a result, it is possible to effectively prevent combustion exhaust from being discharged obliquely downward from the exhaust outlet.

Fig. 3 is a cross-sectional view of the combustion section 18, the heat exchanger 19, and the exhaust section 30 in the housing of the water heater. 3 is a cross-sectional view of an exhaust section 30; FIG. FIG. 3 is a partially enlarged view of a W region shown in FIG. 2; 3 is a perspective view of an inclined plate 80; FIG. FIG. 5 is a sectional view taken along line II shown in FIG. 4;

Embodiments of the present invention will be described below. Unless otherwise specified, the structures of water heaters and the like described below are merely illustrative examples and are not intended to be limiting. The drawings are used to explain technical features that can be employed by the present invention. In the following description, left and right, front and back, and top and bottom indicated by arrows in the drawings are used.

The structure inside the housing of the water heater 1 will be described with reference to FIGS. 1 and 2. FIG. Note that the housing is omitted in FIG. A combustion unit 18, a heat exchanger 19, and an exhaust unit 30 are provided in this order from the bottom in the upper part of a housing (not shown) of the water heater 1. As shown in FIG. The combustion section 18 has a burner-side casing 21 . In the burner-side casing 21, a plurality of burners (not shown) are arranged side by side in the left-right direction (the depth direction of the paper surface). An air supply fan (not shown) is provided below the combustion section 18 . An air supply fan supplies combustion air to the plurality of burners. The heat exchanger 19 has a heat exchanger-side casing 22 . The heat exchanger side casing 22 is fixed to the upper portion of the burner side casing 21 . In the heat exchanger side casing 22, there are a plurality of fins (not shown) laminated at predetermined intervals in the left-right direction, and a plurality of heat transfer tubes ( (not shown) is provided. Adjacent heat transfer tubes are connected by a U-shaped connecting tube 20A to form a series of tubular bodies 20 connected in a meandering manner.

One end of a water inlet pipe 27 is connected to the upstream end of the tubular body 20 . The other end of the water inlet pipe 27 is connected to a water inlet (not shown) provided at the bottom of the housing. One end of a tapping pipe 28 is connected to the downstream end of the tubular body 20 . The other end of the tapping pipe 28 is connected to a tapping port (not shown) provided at the bottom of the housing. As a result, the water that has flowed in from the water inlet flows through the water inlet pipe 27 and flows into the tubular body 20 of the heat exchanger 19 . As the combustion exhaust gas from the combustion section 18 passes through the gaps between the heat transfer tubes of the tubular body 20, heat exchange is performed between the heat transfer tubes and the water flowing through the heat transfer tubes. The water flowing through the tubular body 20 becomes hot water, flows through the hot water outlet pipe 28, and is supplied to the outside from the hot water outlet.

The exhaust section 30 includes an exhaust casing 40 and a current plate 50 (see FIG. 2). The exhaust casing 40 is fixed to the upper portion of the heat exchanger side casing 22 and communicates with the exhaust stack 9 . The exhaust pipe 9 is inserted into an opening provided in the upper part of a cover (not shown) attached to the front surface of the housing and protrudes forward. The front portion of the exhaust casing 40 protrudes forward from the heat exchanger 19 . The straightening plate 50 is supported inside the exhaust casing 40 and forms an exhaust passage for the combustion exhaust that has flowed into the exhaust casing 40 from the heat exchanger 19 .

The shape of the exhaust casing 40 will be described with reference to FIG. The exhaust casing 40 has an upper surface shape that protrudes upward at the rear portion and gradually lowers toward the front. The exhaust casing 40 has a rectangular opening 400 in a front view. The exhaust casing 40 includes a curved portion 41, a top portion 42, an inclined portion 43, and a front extending portion 44 in order from the rear to the front, and a pair of side portions 45 on both left and right sides thereof. The curved portion 41 rises vertically upward and curves forward in an arc shape at the upper portion. The top portion 42 extends substantially horizontally forward from the front end portion of the curved portion 41 . The inclined portion 43 is inclined obliquely downward from the front end portion of the uppermost portion 42 . The front extending portion 44 extends forward and substantially horizontally from the front end portion of the inclined portion 43 . A pair of side surface portions 45 hang down from both left and right end portions of the curved portion 41 , the top portion 42 , the inclined portion 43 , and the front extending portion 44 to form both left and right side surfaces of the exhaust casing 40 .

The exhaust casing 40 further includes a mounting flange portion 46 , an upper flange portion 47 , an outer folded portion 48 and a plurality of crimped portions 49 . The mounting flange portion 46 is the front end portion of the exhaust casing 40 and is provided along the front end portion of the forward extending portion 44 and the front end portions of the pair of side portions 45 . The mounting flange portion 46 protrudes outward in a flange shape and is formed in a substantially U-shape that opens downward when viewed from the front. The upper flange portion 47 is provided along the lower end portion of the curved portion 41 and the respective lower end portions of the pair of side portions 45 . The upper flange portion 47 protrudes outward in a flange shape and is formed in a substantially U-shape that opens forward in a bottom view. The outer folded portion 48 is provided along the outer peripheral portion of the upper flange portion 47 and folds downward to protrude. A plurality of crimped portions 49 are provided along the lower end portion of the outer folded portion 48 . A lower flange portion 211 provided at the upper end portion of the heat exchanger side casing 22 is arranged below the upper flange portion 47, and each of the plurality of crimping portions 49 is bent inward and crimped and fixed. As a result, the exhaust casing 40 is fixed to the upper portion of the heat exchanger side casing 22 (see FIG. 1).

The structure of the exhaust pipe 9 will be described with reference to FIG. The exhaust pipe 9 is fixed to the front portion of the exhaust casing 40 and is formed in a substantially rectangular tubular shape that protrudes substantially horizontally forward. An exhaust outlet 92 is provided in the front portion of the exhaust pipe 9 . The exhaust outlet 92 is formed in a substantially elliptical shape elongated in the left-right direction when viewed from the front. A burring portion 91 for preventing injury is provided on the periphery of the exhaust outlet 92 . The burring portion 91 is formed by folding backward so as to wind inward. Therefore, the burring portion 91 is provided with an inclined surface 91A that is inclined so as to decrease in diameter from the upstream side toward the downstream side in the flow direction of the combustion exhaust gas. A rear end portion of the exhaust pipe 9 is provided with a flange portion 93 projecting outward in a flange shape. The flange portion 93 is formed in a substantially rectangular ring shape elongated in the left-right direction when viewed from the front. A substantially cylindrical protective member 10 made of resin is attached to the outer peripheral portion of the exhaust pipe 9 .

An inclined plate 80 having a substantially V-shaped side view is provided on the upper part inside the exhaust pipe 9 . The inclined plate 80 is inclined downward from the rear end side to the front end side of the exhaust pipe 9, bent obliquely upward in the middle, and inclined upward toward the upper edge side of the exhaust outlet 92. . The inclined plate 80 controls the flow of the combustion exhaust gas in the exhaust pipe 9, thereby preventing the combustion exhaust gas from being discharged obliquely downward from the exhaust outlet 92. As shown in FIG. The function and effect of the inclined plate 80 inside the exhaust pipe 9 will be described later.

In the exhaust pipe 9 having the above structure, a mounting flange portion 46 provided at the front end portion of the exhaust casing 40 via a packing 96 with respect to the upper half region of the rear surface of the flange portion 93, and a fixing plate 70 described later. , and are fixed by four screws 63 (only one is shown in FIGS. 2 and 3) arranged in the left-right direction. On the other hand, a mounting piece 55 provided at a front end portion of a lower plate portion 51 (described later) of the rectifying plate 50 is arranged in the lower half region of the rear surface of the flange portion 93 via a packing 96 and arranged in the left-right direction. It is fixed with five screws 64 (only one is shown in FIGS. 2 and 3). As a result, the exhaust pipe 9 is fixed to the front side of the front end portion of the exhaust casing 40 and the front end portion of the lower plate portion 51 of the current plate 50 . An exhaust outlet 92 of the exhaust stack 9 is arranged in front of the opening 400 of the exhaust casing 40 . Therefore, the exhaust pipe 9 can receive the combustion exhaust through the opening 400 of the exhaust casing 40 and discharge it to the outside through the exhaust outlet 92 .

The fixing plate 70 has a generally crank-like shape when viewed from the side, and includes a horizontal portion 71 , a housing-side fixing portion 72 , and a flange-side fixing portion 73 . The horizontal portion 71 extends in the front-rear direction and has a substantially rectangular shape elongated in the left-right direction in plan view. The housing-side fixing portion 72 extends vertically upward from the rear end portion of the horizontal portion 71 and is fixed by a screw 65 to a support member (not shown) provided inside the housing. The flange-side fixing portion 73 hangs down from the front end portion of the horizontal portion 71 and is fixed to the flange portion 93 of the exhaust pipe 9 with screws 63 via the packing 96 and the mounting flange portion 46 . As a result, the exhaust pipe 9 is stably supported by the housing while protruding forward.

The shape of the current plate 50 will be described with reference to FIGS. 2 and 3. FIG. The straightening plate 50 is formed by bending a single sheet metal, for example, and includes a lower plate portion 51 , a folded portion 52 , an upper plate portion 53 , a pair of upper fixing portions 58 , a pair of lower fixing portions 59 , and a guide plate 57 . The lower plate portion 51 gently inclines obliquely upward from the front to the rear. A mounting piece 55 (see FIG. 3) is provided at the front end of the lower plate portion 51 . The mounting piece 55 is formed by folding the front end portion of the lower plate portion 51 downward at a substantially right angle, and is formed in a substantially rectangular shape elongated in the left-right direction when viewed from the front. The folded portion 52 is folded upward from the rear end portion of the lower plate portion 51 and folded forward in a substantially arc shape. The upper plate portion 53 extends forward and substantially horizontally from the front end portion of the folded portion 52 . The front end portion of the upper plate portion 53 is provided with an inclined end portion 531 (see FIG. 2) inclined obliquely downward. The slanted end 531 is located below the connection between the uppermost portion 42 and the slanted portion 43 of the exhaust casing 40 .

The pair of upper fixing portions 58 hang down from both left and right ends of the upper plate portion 53 and are formed in a substantially rectangular shape in a side view. The pair of upper fixing portions 58 abut on the inner surfaces of the pair of side portions 45 of the exhaust casing 40 and are fixed by screws 61 . The pair of lower fixing portions 59 protrude upward from the front portions of the left and right ends of the lower plate portion 51 and are formed in a substantially trapezoidal shape when viewed from the side. The pair of lower fixing portions 59 abut against the inner surfaces of the pair of side portions 45 of the exhaust casing 40 and are fixed with screws 62 . As a result, the current plate 50 is stably supported inside the exhaust casing 40 .

The guide plate 57 is fixed so as to cover a region of the upper surface of the lower plate portion 51 excluding the rear end side, and is formed in a substantially rectangular shape in plan view. The guide plate 57 includes a rear horizontal portion 571, an inclined portion 572, and a front horizontal portion 573 in order from the rear end side to the front end side. The rear horizontal portion 571 extends substantially horizontally forward from the rear end side. The sloped portion 572 slopes downward from the front end of the rear horizontal portion 571 . The front horizontal portion 573 extends forward and substantially horizontally from the front end portion of the inclined portion 572 . The guide plate 57 is fixed to the lower plate portion 51 of the current plate 50 with screws at the rear horizontal portion 571 and the front horizontal portion 573 .

The shape of the inclined plate 80 will be described with reference to FIGS. 4 and 5. FIG. The inclined plate 80 is formed, for example, by bending a piece of sheet metal, and includes a downward inclined portion 81 , an upward inclined portion 82 and a fixed plate portion 83 . The descending slope portion 81 slopes downward from the rear end side to the front end side, and is formed in a substantially rectangular shape elongated in the horizontal direction in a plan view. The upward slope portion 82 is bent obliquely upward (approximately 90° direction) from the front end portion of the downward slope portion 81 and is formed in a substantially rectangular shape that is long in the horizontal direction when viewed from the front. The downward slope portion 81 and the upward slope portion 82 form a substantially V-shaped bent portion when viewed from the side. The length from the rear end portion to the front end portion of the downward slope portion 81 is longer than the length from the rear end portion to the front end portion of the upward slope portion 82 .

In the vicinity of the right end portion of the upward slope portion 82, a groove portion 821 is provided by notching the portion from the upper end portion to the vicinity of the lower end portion in an elongated, substantially rectangular shape. A locking claw 85 is provided at the lower edge of the groove 821 . The locking claw 85 rises upward from the lower edge of the groove 821, and its upper end side is bent forward in a substantially V shape in a side view. On the other hand, in the vicinity of the left end of the upwardly inclined portion 82, a groove 822 is provided by notching the upper end to the vicinity of the lower end in an elongated, substantially rectangular shape. A locking claw 86 is provided at the lower edge of the groove 822 . Like the locking claw 85, the locking claw 86 rises upward from the lower edge of the groove 822, and the upper end side thereof is bent forward in a substantially V shape in a side view. The tips of the locking claws 85 and 86 are preferably bent slightly upward. Thereby, the locking claws 85 and 86 can be easily locked to the burring portion 91 .

The fixing plate portion 83 extends vertically upward from the central portion of the rear end portion of the downwardly inclined portion 81 excluding the left and right side portions, and is formed in a substantially rectangular shape elongated in the left and right direction when viewed from the front. A pair of short plate portions 84 are provided on both left and right sides of the rear end portion of the downward slope portion 81 . A pair of short plate portions 84 protrude vertically upward from the left and right side portions of the rear end portion of the downward slope portion 81 and are connected to the fixed plate portion 83 . A pair of fixing grooves 831 and 832 are provided at the upper end of the fixing plate portion 83 . The fixing groove portions 831 and 832 are provided at positions spaced apart from each other in the left-right direction, and are formed by notching the fixing plate portion 83 from the upper end toward the lower end in a substantially U shape. The fixing grooves 831 and 832 have widths through which the threaded portions of the screws 63 can be inserted.

The mounting structure of the inclined plate 80 will be described with reference to FIG. The inclined plate 80 is arranged in the upper part of the exhaust pipe 9 so that the upwardly inclined portion 82 is on the front side and the fixed plate portion 83 is on the rear side. The pair of locking claws 85 and 86 are locked to a burring portion 91 provided at the upper edge of the exhaust outlet 92 of the exhaust pipe 9 from behind. Thereby, the front end side of the inclined plate 80 is stably supported. On the other hand, the fixed plate portion 83 of the inclined plate 80 is sandwiched between the flange portion 93 of the exhaust pipe 9 and the packing 96 . Inside the pair of fixing groove portions 831 and 832 of the fixing plate portion 83, the screw portions of the central two screws 63 of the four screws 63 are inserted. The fixing plate portion 83 is fixed while being sandwiched between the flange portion 93 of the exhaust pipe 9 and the mounting flange portion 46 of the exhaust casing 40 . Thereby, the rear end side of the inclined plate 80 is stably supported. In this manner, the inclined plate 80 is attached to the upper portion within the exhaust stack 9 .

In the exhaust pipe 9 , the downward slope portion 81 slopes downward from the rear end side of the exhaust pipe 9 to the front end side. At approximately the central portion of the exhaust pipe 9 in the front-rear direction, the upward sloping portion 82 bends obliquely upward from the front end portion of the downward sloping portion 81 and slopes upward toward the upper edge portion side of the exhaust outlet 92 .

The flow of combustion exhaust in the exhaust section 30 will be described with reference to FIGS. 2 and 3. FIG. As shown in FIG. 2, the combustion exhaust that has passed through the heat exchanger 19 flows into the exhaust casing 40 from below. The combustion exhaust flows rearward along the lower plate portion 51 of the current plate 50 and is folded back forward along the folded portion 52 . The combustion exhaust flows forward along the upper plate portion 53 and is guided obliquely downward along the inclined portion 43 of the exhaust casing 40 . At this time, downward momentum is added to the combustion exhaust gas. The combustion exhaust flows obliquely downward, contacts the guide plate 57 and flows toward the opening 400 .

Next, as shown in FIG. 3 , the combustion exhaust flows into the exhaust stack 9 through the opening 400 . Inside the exhaust pipe 9 , the passing cross-sectional area of the exhaust passage is temporarily reduced by the downward slope portion 81 of the slope plate 80 and then enlarged at once by the upward slope portion 82 . Thereby, a venturi effect can be produced in the exhaust pipe 9 . When the passage cross-sectional area is reduced by the downward slope portion 81 due to the venturi effect, the combustion exhaust gas is generated in the region P, which is the upper region of the exhaust passage, near the bent portions of the downward slope portion 81 and the upward slope portion 82. flow velocity increases. In region P, the pressure of the combustion exhaust becomes low. That is, by providing the inclined plate 80 in the upper part of the exhaust pipe 9, the combustion exhaust flowing in the upper part of the exhaust passage in the exhaust pipe 9 can be guided obliquely downward. The flow velocity of the combustion exhaust gas can be increased and the pressure can be decreased in the upper region P of the portion.

As a result, the combustion exhaust that has flowed into the exhaust stack 9 is attracted to the region P where the pressure is low. For example, the combustion exhaust horizontally passing through the lower side of the exhaust pipe 9 is drawn into the region P, changes its direction diagonally upward, and passes through the region P. As shown in FIG. Therefore, even if the combustion exhaust gas flowing into the exhaust stack 9 is imparted with downward momentum, the downward momentum disappears as it passes through the area P, and is pushed obliquely upward and discharged to the outside. be. Therefore, it is possible to prevent combustion exhaust from being discharged obliquely downward from the exhaust outlet 92, so that it is possible to prevent a person below the exhaust outlet 92 from feeling uncomfortable.

Further, when passing through the region P in the exhaust pipe 9, the upwardly inclined portion 82 of the inclined plate 80 is positioned on the upper side, and the burring portion 91 of the lower edge portion of the exhaust outlet 92 is positioned on the lower side. The upward slope portion 82 slopes upward from the front end portion of the downward slope portion 81 toward the upper edge portion of the exhaust outlet 92 . The inclined surface 91A of the lower burring portion 91 inclines obliquely upward from the upstream side through which the combustion exhaust flows toward the downstream side. Accordingly, the combustion exhaust that has passed through the region P is guided obliquely upward by the upward slope portion 82 and the slope surface 91A, and is thus discharged from the exhaust outlet 92 slightly upward. As a result, downward discharge of the combustion exhaust from the exhaust outlet 92 can be more effectively prevented.

As described above, the water heater 1 of this embodiment includes the exhaust casing 40 , the exhaust pipe 9 , and the current plate 50 . The exhaust casing 40 is provided above the heat exchanger 19, and has an opening 400 extending forward from the heat exchanger 19 and discharging combustion exhaust gas passing upward through the heat exchanger 19 to the outside. Prepare. The exhaust casing 40 protrudes upward at the rear portion and has an upper surface shape that slopes down toward the front. The exhaust pipe 9 is connected to the opening 400 and protrudes forward in a cylindrical shape. The exhaust pipe 9 has an exhaust outlet 92 that is longer in the horizontal direction than in the vertical direction at the front, and exhausts the combustion exhaust discharged from the opening 400 to the outside. The straightening plate 50 is supported in the exhaust casing 40 and straightens the combustion exhaust that has passed through the heat exchanger 19 upward toward the opening 400 . A sloped plate 80 having a V shape in a side view is provided on the inner upper portion of the exhaust pipe 9 . The inclined plate 80 is inclined downward from the rear end side to the front end side of the exhaust pipe 9 , bent obliquely upward in the middle, and inclined upward toward the upper edge side of the exhaust outlet 92 .

In the exhaust casing 40, the combustion exhaust after flowing along the upper plate portion 53 from the folded portion 52 of the straightening plate 50 is guided downward by the downwardly inclined upper surface shape of the exhaust casing 40. may add downward momentum to Inside the exhaust stack 9 , the flow velocity of the combustion exhaust flowing into the exhaust stack 9 increases due to the portion of the inclined plate 80 that slopes downward. As a result, a low-pressure region P is formed in the vicinity of the bent portion of the inclined plate 80 . A region P is a region above a portion of the exhaust passage in the exhaust pipe 9 where the passage cross-sectional area is the smallest. Therefore, the combustion exhaust gas that has flowed into the exhaust stack 9 is drawn into the region P, loses its downward momentum, and passes through the region P to be pushed obliquely upward and discharged to the outside. Therefore, it is possible to prevent combustion exhaust from being discharged obliquely downward from the exhaust outlet 92, thereby preventing a person below the exhaust outlet 92 from feeling uncomfortable.

In the above description, the opening 400 of the exhaust casing 40 is an example of the "opening" of the present invention. The burring portion 91 of the exhaust pipe 9 is an example of the "folding portion" of the present invention. The fixed plate portion 83 of the inclined plate 80 is an example of the "fixed portion" of the present invention. The pair of locking claws 85 and 86 of the inclined plate 80 is an example of the "locking portion" of the present invention.

The present invention is not limited to the above embodiments, and various modifications are possible. The rectifying plate 50 is made of a single sheet metal, but may be made of a combination of a plurality of metal plates. The shape of the straightening plate 50 is not limited to the above-described embodiment, and various modifications may be made. The guide plate 57 may be omitted. The support structure of the current plate 50 in the exhaust casing 40 is also not limited to the above embodiment, and various modifications are possible.

The inclined plate 80 is provided with a fixed plate portion 83 and a pair of locking claws 85 and 86 in order to be mounted in the exhaust pipe 9, but may be mounted by other methods such as welding or using an adhesive. Fixing using other members such as fixtures or fixtures may also be used. In that case, at least the downward slope portion 81 and the upward slope portion 82 should be provided, and one or both of the fixing plate portion 83 and the pair of locking claws 85 and 86 may be omitted. The bending angle of the downward slope portion 81 and the upward slope portion 82 is not limited to 90°, and may be changed.

The fixing grooves 831 and 832 may be changed to holes through which the threaded portion of the screw 65 can be inserted.

Reference Signs List 1 water heater 9 exhaust pipe 19 heat exchanger 40 exhaust casing 50 rectifying plate 80 inclined plate 83 fixed plate portion 85, 86 locking claw 91 burring portion 91A inclined surface 92 exhaust outlet 400 opening

Claims (3)

It is provided above a heat exchanger that heats the water flow with the heat of the combustion exhaust from the burner, and the front part projects forward from the heat exchanger, and the combustion exhaust that has passed upward through the heat exchanger is released to the outside. an exhaust casing provided with an opening for discharging in the front part, protruding upward in the rear part and having an upper surface shape inclined downward toward the front;
The combustion exhaust discharged from the opening is discharged to the outside from the exhaust outlet, which is provided in the opening, protrudes forward in a cylindrical shape, and has a horizontally long rectangular exhaust outlet in the front part that is longer in the horizontal direction than in the vertical direction. an exhaust stack that
A water heater comprising a rectifying plate that is supported in the exhaust casing and rectifies the combustion exhaust that has passed through the heat exchanger upward toward the opening,
The upper part of the inside of the exhaust pipe is inclined downward from the rear end side to the front end side of the exhaust pipe, bends obliquely upward in the middle, and rises toward the upper edge side of the exhaust outlet. A sloped V-shaped plate in a side view is provided ,
The cross-sectional area of the exhaust passage through which the combustion exhaust flows in the exhaust pipe is reduced by the downwardly inclined portion of the inclined plate, and the upwardly inclined portion of the inclined plate reduces the A water heater , wherein a venturi effect is formed in the exhaust pipe by enlarging the passage cross-sectional area . The periphery of the exhaust outlet is provided with a folded portion that is folded back so as to wind inward,
A fixing portion fixed to the front portion of the exhaust casing is provided at the rear end portion of the inclined plate,
2. The water heater according to claim 1, wherein a front end portion of said inclined plate is provided with an engaging portion capable of being engaged from behind with respect to said folded portion provided on said upper edge portion. The periphery of the exhaust outlet is provided with a folded portion that is folded back so as to wind inward,
3. The water heater according to claim 1, wherein the folded portion is provided with an inclined surface that is inclined so as to decrease in diameter from the upstream side toward the downstream side in the flow direction of the combustion exhaust gas.

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