BACKGROUND OF THE INVENTION
Field of the Invention

The present invention relates to a combustion apparatus including a box having an opening at least on a front surface, and a front plate fixed to over the opening of the box.

Description of the Related Art

Combustion apparatuses of this type include a water heater having outward flanges extending outward formed on a peripheral wall of an opening of the box and a peripheral edge of the front plate. The front plate is positioned at upper, lower, left, and right positions with respect to the opening of the box using these outward flanges, and screws are fastened to upper and lower parts of the flanges from the front side of the water heater, whereby the front plate is attached to the opening of the box (See, for example, FIG. 1 of Japanese Patent Application Laid-Open No. 2005-180782).

In the conventional water heater described above, the outward flange is formed on the peripheral edge of the front plate, but it is desirable to eliminate the outward flange from the front plate as much as possible in order to improve the design of the front surface of the water heater. However, when the outward flange is eliminated from the front plate, the front plate cannot be positioned using the outward flange as in the conventional case, and there arises a problem of deterioration in workability of attaching or detaching the front plate at the time of assembly or maintenance of the water heater.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a combustion apparatus that can improve workability of attaching and detaching the front plate while enhancing design of the front surface of the apparatus.

A combustion apparatus including: a box having an opening at least on a front surface; and a front plate fixed to over the opening of the box, in which

an inward flange extending inward is formed at least on an upper part of a peripheral edge of the front plate,

an upper part of the opening of the box is provided with a tongue piece protruding in a front plate direction,

the inward flange of the front plate is provided with a notch restricting a downward movement of the front plate by bringing an upper end of the notch into contact with an upper part of the tongue piece and restricting a left-right movement of the front plate by bringing a side end of the notch into contact with at least one of left and right parts of the tongue piece in a state where the front plate is disposed at a correct position with respect to the opening of the box.

According to the above configuration, the front plate is disposed so as to cover the opening of the box, the notch in the inward flange of the front plate is placed on the tongue piece of the opening of the box, and the upper end of the notch is brought into contact with the upper part of the tongue piece, whereby the downward movement of the front plate is restricted and the front plate is positioned in the up-down direction with respect to the opening of the box. Since the side end of the notch is brought into contact with at least one of the left and right parts of the tongue piece, the left-right movement of the front plate is restricted, and therefore the front plate is positioned in the left-right direction with respect to the opening of the box. Therefore, the front plate can be easily attached to a correct position matching the up-down and left-right positions with respect to the opening of the box even without fastening with screws. Hence, workability at the time of assembly or maintenance of the apparatus is improved. In the upper part of the peripheral edge of the front plate, the flange is provided as an inward flange extending inward, so that the design of the front surface of the apparatus can be improved. As described above, it is possible to improve workability of attaching and detaching the front plate while enhancing design of the front surface of the apparatus.

The combustion apparatus can be configured that

an upper part of the front plate is fixed by a draw latch provided on a top surface of the box, and the lower part of the front plate is fixed by fastening a screw at a bottom surface of the box.

According to this configuration, the front plate disposed at the correct position with respect to the opening of the box can be easily fixed to the opening of the box by the draw latch (also called patch latch, snap latch, etc.). Therefore, the number of attachment man-hours of the front plate can be reduced as compared with the case where the front plate is attached only by screw fastening. By fixing the upper part of the front plate with the draw latch, it is possible to hold the front plate so as not to fall down, and it is possible to easily perform the work of attaching and detaching of the screw at the lower part of the front plate. Therefore, workability at the time of assembly or maintenance of the apparatus is improved. By fastening the front plate with the screw at the bottom surface of the box, it is possible to make the screw inconspicuous, and the design of the front surface of the apparatus is not impaired.

In the combustion apparatus,

an upper part of the opening of the box is provided with a reinforcing member having the tongue piece formed.

According to this configuration, the tongue piece can be easily formed in the opening of the box. The reinforcing member can enhance the attachment strength of the front plate in the upper part of the opening of the box. Thus, the front plate can be stably held in the box.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a front view showing a state where a water heater according to an embodiment is viewed from the front;

FIG. 1B is a front view showing a state where a front plate in the water heater according to the embodiment is removed;

FIG. 2A is a back view showing a back surface of the front plate in the water heater according to the embodiment;

FIG. 2B is a side view showing a side surface of the front plate in the water heater according to the embodiment;

FIG. 3 is a perspective view showing upper parts of a box and the front plate in the water heater according to the embodiment;

FIG. 4 is an enlarged side view in which an upper part and a lower part of the water heater according to the embodiment in a state where a front surface side of the water heater is viewed from the side;

FIG. 5 is a perspective view of a top surface side of the water heater according to the embodiment as viewed obliquely from above; and

FIG. 6 is a perspective view of a bottom surface side of the water heater according to the embodiment as viewed obliquely from below.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIGS. 1A and 1B, the combustion apparatus according to the embodiment is a water heater 1 including a box 2 having an opening 20 on a front surface and a front plate 3 fixed to cover the opening 20 of the box 2. In the box 2, as shown in FIG. 1B, a blower 11, a combustion chamber 12, a heat exchange chamber 13, and an exhaust chamber 14 are disposed in this order from the bottom, and an exhaust pipe 15 is connected to the upper surface of the exhaust chamber 14. In the present specification, in a front view shown in FIGS. 1A and 1B, a depth direction (thickness direction) of the water heater 1 is referred to as a front-rear direction, a direction intersecting the front-rear direction in the lateral direction is referred to as a left-right direction, and a direction intersecting the front-rear direction in the height direction is referred to as an up-down direction.

In the combustion chamber 12, a burner 12a for generating combustion exhaust gas is disposed. A gas supply pipe 16 for supplying fuel gas is connected to the burner 12a. The heat exchange chamber 13 accommodates therein a heat exchanger 13a including a plurality of heat transfer fins 13b and a heat transfer pipe 13c inserted through each of the heat transfer fins 13b. A water supply pipe 17 is connected to one end side of the heat transfer pipe 13c, and a hot-water outlet pipe 18 is connected to the other end side of the heat transfer pipe 13c. When the water heater 1 is operated, the blower 11 is actuated and the burner 12a is combusted, so that water supplied from the water supply pipe 17 into the heat exchanger 13a is heated by the combustion exhaust gas of the burner 12a, and hot water is supplied to a hot water supply terminal such as a shower or a faucet through the hot-water outlet pipe 18. The combustion exhaust gas having passed through the heat exchanger 13a is discharged from the exhaust chamber 14 to the outside of the apparatus through the exhaust pipe 15. In the present invention, as the fluid heated by the heat exchanger 13a, another fluid may be used instead of water.

Next, the box 2 and the front plate 3 of the water heater 1 will be described.

As shown in FIG. 1B, the box 2 is formed in a rectangular box shape having a top surface 21a, a rear surface 21b, a right side surfaces 21c, a left side surface 21d, and a bottom surface 21e, and has the opening 20 provided on the front surface. The top surface 21a, the left and right side surfaces 21c and 21d, and the bottom surface 21e of the box 2 constitute a peripheral wall of the opening 20. The box 2 is formed by joining a substantially inverted U-shaped sheet metal constituting the top surface 21a and the left and right side surfaces 21c and 21d, and a substantially L-shaped sheet metal constituting the rear surface 21b and the bottom surface 21e. The top surface 21a of the box 2 is provided with a substantially U-shaped notch 22 (see FIG. 5) formed by opening and cutting the front end of the top surface 21a, and the exhaust pipe 15 protrudes from the notch 22 to the upward of the top surface 21a.

The peripheral wall of the opening 20 of the box 2 is provided with a box-side inward flange 23 extending inward over substantially the entire circumference. The box-side inward flange 23 is formed by bending inward and extending each front end part of the top surface 21a, the left and right side surfaces 21c and 21d, and the bottom surface 21e of the box 2.

As also shown in FIG. 3, an upper part of the opening 20 of the box 2 is provided with a reinforcing member 24. The reinforcing member 24 is formed of a horizontally long sheet metal bent in a substantially L shape, and is attached to the inner surface of the top surface 21a with a screw or the like so as to close the front part of the notch 22 and the upper part of the opening 20 opened by the notch 22. Accordingly, the center part of the upper part of the opening 20 is opened by the notch 22 of the top surface 21a, but the front surface part of the reinforcing member 24 constitutes a part of the box-side inward flange 23 of the upper part.

The upper part of the opening 20 of the box 2 is provided with a tongue piece 25 protruding in the direction of the front plate 3 of the front surface. The tongue piece 25 serves as an engaging member that engages with the front plate 3 to dispose the front plate 3 at a correct position with respect to the opening 20 of the box 2. The tongue piece 25 protrudes forward from the lower end of the box-side inward flange 23 in the upper part of the opening 20, and is disposed at each of the left and right positions of the box-side inward flange 23 in the upper part. The tongue piece 25 is formed of a flat plate member extending in the horizontal direction. The tongue piece 25 has an upper surface part 25a and a lower surface part 25b, which are upper and lower extending surfaces, and a right end part 25c and a left end part 25d, which are left and right side end parts, and has, at a tip end part, a shape in which a hook 25e bent so as to face obliquely upward is formed. The upper surface part 25a of the tongue piece 25 is an upper part of the tongue piece 25, and the right end part 25c and the left end part 25d are left and right parts of the tongue piece 25.

The tongue piece 25 is provided at the lower end part of the reinforcing member 24, and the tongue piece 25 protrudes forward of the opening 20 by attaching the reinforcing member 24 to the top surface 21a. This makes it possible to easily form the tongue piece 25 in the opening 20 of the box 2. The tongue piece 25 is not limited to be formed in the reinforcing member 24, and may be formed on the lower end part of the upper box-side inward flange 23. The tongue piece 25 is not limited to one in which the flat plate member extends in the horizontal direction (horizontal placement), and may be various protrusions or the like such as one in which the flat plate member extends in the vertical direction (vertical placement).

As shown in FIG. 2A and FIG. 2B, the front plate 3 is formed in a rectangular shallow bottom box shape having a rectangular front surface part 31 matching the outer shape of the box 2, and a bent part 32 formed by bending rearward the upper side, the left and right sides, and the lower side of the front surface part 31. The peripheral edge of the front plate 3 is constituted by the rear end part of the bent part 32. The peripheral edge of the front plate 3 is provided with a front plate-side inward flange 33 extending inward by bending inward and extending each rear end part of the upper side part and the left and right side parts. Due to this, in a front view of the water heater 1, the flange is not exposed at the peripheral edge of the front plate 3, and the design of the front surface of the apparatus is improved.

As also shown in FIG. 3, the front plate-side inward flange 33 of the upper part is provided with notches 34 at the left and right positions of the lower end. These notches 34 serve as engaging parts to be engaged with the tongue piece 25 provided in the opening 20 of the box 2. That is, each of the notches 34 is provided such that, when the front plate 3 is disposed at the correct position with respect to the opening 20 of the box 2, a downward movement of the front plate 3 is restricted by coming into contact with the upper surface part 25a of the tongue piece 25 with respect to the tongue piece 25 provided at the upper part of the opening 20 of the box 2, and a left-right movement of the front plate 3 is restricted by coming into contact with one of the left and right end parts 25c and 25d of the tongue piece 25.

The notch 34 is formed such that left and right corner parts at the lower end of the front plate-side inward flange 33 of the upper part are cut out to have a horizontal upper end part 34a and a vertical side end part 34b and to open the side end side of the front plate-side inward flange 33 of the upper part. This causes the front plate 3 to laterally move with the front plate 3 facing the opening 20 of the box 2, and the notch 34 to be easily engaged with the tongue piece 25 of the opening 20 of the box 2. The notch 34 has the side end part 34b formed vertically, but the notch 34 may have a fan shape with the side end part 34b inclined toward the center side of the front plate-side inward flange 33 of the upper part toward the lower side. The notch 34 may have a shape cut out into a quadrangular shape without opening the side end side of the front plate-side inward flange 33 of the upper part.

As shown in FIGS. 4 and 5, in the box 2 and the front plate 3, the top surface 21a of the box 2 is provided with a pair of draw latches (also called patch latches, snap latches, etc.) 51 symmetrically at the front side position, and the bent part 32 on the upper surface of the front plate 3 is provided with a pair of hooks 52 for hooking the draw latches 51 of the box 2 symmetrically. The draw latches 51 and the hooks 52 can be attached by screwing or the like. As shown in FIGS. 4 and 6, in the box 2 and the front plate 3, the bottom surface 21e of the box 2 is provided with a pair of downward protruding symmetrical convex parts 53 provided with screw holes 54 (see FIG. 1B) for fastening screws 57 at the front position, and the lower surface of the front plate 3 is provided with a pair of downward protruding symmetrical projection pieces 55 provided with through holes 56 (see FIG. 2A) corresponding to the screw holes 54 of the box 2 at the rear end part of the bent part 32. The front surface of the convex part 53 provided with the screw hole 54 in the box 2 is an inclined surface inclined rearward as it goes downward, and the projection piece 55 provided with the through hole 56 in the front plate 3 is bent and formed so as to be inclined rearward as it goes downward (see FIG. 4). Therefore, when the screw 57 is fastened to the through hole 56 and the screw hole 54, the water heater 1 does not interfere with insertion of the tool, and the tool can be inserted obliquely upward from a wide space below the water heater 1 to easily perform the screw fastening work.

With the above configuration, when the front plate 3 is attached to the opening 20 of the box 2, the front plate 3 is disposed so as to cover the opening 20 of the box 2, and the notch 34 in the front plate-side inward flange 33 of the upper part of the front plate 3 is placed on the tongue piece 25 at the upper part of the opening 20 of the box 2. Due to this, the upper end part 34a of the notch 34 of the front plate 3 comes into contact with the upper surface part 25a of the tongue piece 25 of the box 2, whereby the downward movement of the front plate 3 is restricted, and the front plate 3 is positioned in the up-down direction with respect to the opening 20 of the box 2. The side end part 34b of the notch 34 of the front plate 3 comes into contact with one of the left and right end parts 25c and 25d on the tongue piece 25 of the box 2, whereby the left-right movement of the front plate 3 is restricted, and the front plate 3 is positioned in the left-right direction with respect to the opening 20 of the box 2. Therefore, the front plate 3 can be easily attached to a correct position matching the up-down and left-right position with respect to the opening 20 of the box 2 without screw fastening.

Since the tongue piece 25 of the box 2 is provided with the hook 25e bent so as to face obliquely upward at the tip end part, the engagement with the notch 34 of the front plate 3 is hardly released by the hook 25e, and the attachment work of the front plate 3 can be easily performed. The upper part of the opening 20 of the box 2 is provided with the reinforcing member 24, and the reinforcing member 24 is provided with the tongue piece 25 for engaging the front plate 3, and therefore the reinforcing member 24 strengthens the attachment strength of the front plate 3 in the upper part of the opening 20 of the box 2, and the front plate 3 can be stably held in the box 2.

Then, in the positioning state, the draw latch 51 on the top surface 21a of the box 2 is hooked and fastened to the hook 52 on the upper surface of the front plate 3, and then the projection piece 55 on the lower part of the front plate 3 is superposed on the convex part 53 of the bottom surface 21e of the box 2, and the screw 57 is fastened to the through hole 56 and the screw hole 54, whereby the front plate 3 is fixed to the box 2. Thus, attachment of the front plate 3 to the opening 20 of the box 2 is completed.

When detaching the front plate 3 from the box 2, it is possible to easily detach the front plate 3 by detaching the screw 57 of the lower part and unlocking the draw latch 51 of the upper part. At this time, even when the screw 57 of the lower part of the front plate 3 is removed, the upper part of the front plate 3 is fixed by the draw latch 51, and therefore the front plate 3 can be prevented from falling. Even when the draw latch 51 is unlocked next, the notch 34 of the front plate 3 is engaged with the tongue piece 25 of the box 2, and therefore the front plate 3 can be prevented from falling.

As described above, when attaching the front plate 3 to the opening 20 of the box 2, as the inward flange where the flange of the front plate 3 extends inward, it is possible to easily position and attach the front plate 3 to the opening 20 of the box 2 at the up-down and left-right position by engaging the notch 34 of the front plate 3 with the tongue piece 25 of the box 2. The front plate 3 positioned at the correct position with respect to the opening 20 of the box 2 can be easily fixed to the opening 20 of the box 2 by the draw latch 51. Therefore, the number of attachment man-hours of the front plate 3 can be reduced as compared with the case where the front plate 3 is attached only by screw fastening. By fixing the upper part of the front plate 3 with the draw latch 51, it is possible to hold the front plate 3 so as not to fall down, and it is possible to easily perform the work of attaching and detaching of the screw 57 at the lower part of the front plate 3. Therefore, workability at the time of assembly or maintenance of the apparatus is improved.

With the flange of the front plate 3 being an inward flange (front plate-side inward flange 33) extending inward, the flange is not exposed at the peripheral edge of the front plate 3 in a front view of the water heater 1, so that the design of the front surface of the apparatus can be improved. By fastening the screws of the front plate 3 on the bottom surface 21e of the box 2 by the convex part 53 and the projection piece 55, and by fastening the screw 57 obliquely, it is possible to make the screw 57 inconspicuous, and the design of the front surface of the apparatus is not impaired.

Therefore, according to the water heater 1 of the embodiment, it is possible to improve workability of attaching and detaching the front plate 3 while enhancing design of the front surface of the apparatus.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of claims. For example, the number of the tongue pieces 25 and the notches 34 is not limited to two, and one or three or more of them may be provided. Furthermore, the tongue piece 25 positioning the front plate 3 in the left-right direction and the tongue piece 25 positioning the front plate 3 in the up-down direction may be separately provided. The present invention is not limited to the water heater, and can also be applied to various combustion apparatuses such as a heating apparatus and a hot water supply apparatus.