JP2020024076A - Water heater and processing method of front cover for water heater - Google Patents

Abstract

To maintain designability by preventing generation of wrinkles at a folded part even when drawing reaching the folded part is performed on a front plate of a shallow box-shaped front cover.SOLUTION: In a water heater, a housing for storing a combustion device comprises a box body in which a front surface is opened, and a front cover 4 to be assembled to the front surface of the box body. The front cover 4 has a shallow box-shape comprising a rectangular front plate, and top, bottom, left and right folded parts folded backward from four sides of the front plate respectively. At the front plate, a drawing part (recess 47) on which drawing recessed to the rear side is performed is formed to reach a folded part 42. At the folded parts 42, 43 where the recess 47 reaches, a folded portion 52A from the portion other than the recess 47 is formed in a chamfered manner.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a water heater for heating water passing through a heat exchanger with combustion exhaust gas from a burner, and to a method of processing a front cover used for a housing of the water heater.

The water heater has a combustion device such as a burner or a heat exchanger housed in a housing. The housing is assembled by screwing the front cover from the front to the front of the box main body, which has five closed surfaces except the front. Can be For example, as disclosed in Patent Document 1, the front cover is assembled by bending engagement portions on the four sides of the opening of the box body, while also forming similar engagement portions on the four sides around the front cover. It is formed by bending and engaging the engaging portion of the box body and the engaging portion of the front cover with screws from the front.
In addition, in consideration of the case where the water heater is installed indoors, drawing is performed on the front surface of the front cover to form a three-dimensional pattern or unevenness, or a resin panel or the like is fitted into the drawn portion. Attempts have been made to enhance the design (see, for example, a water heater disclosed in Patent Document 2).
Further, in the front cover, a bent portion bent rearward is formed on four sides around the front plate to form a shallow box, so that the circumferential surfaces of the bent portion and the box body are flush with each other. It is common practice to enhance the integration with the main body and further improve the aesthetic appearance.

JP 2015-155773 A Design Registration No. 1460584

  However, when a concave portion or the like is drawn on the front plate of the front cover, if the range of the drawn portion is expanded to the bent portion, wrinkles are generated between the drawn portion and the non-drawn portion in the bent portion. This is because the height (depth) of the narrowed portion differs from that of the non-drawn portion. Therefore, the bending length required for bending from the drawn portion and the bending length required for bending from the non-drawn portion are smaller than those from the non-drawn portion. And the excess sheet metal (meat) in the drawn portion in the bending process escapes to the non-drawn portion side. Due to this wrinkle, even if a design is applied to the front plate, the aesthetic appearance is impaired.

  Therefore, the present invention provides a water heater that can prevent the generation of wrinkles in the bent portion and maintain the design even if the front plate of the front cover in the shape of a shallow box is subjected to drawing to reach the bent portion. And a method for processing a front cover for a water heater.

In order to achieve the above object, the invention according to claim 1 has a housing for housing a combustion device, the housing includes a box body having an open front, and a front cover assembled to the front of the box body. And the front cover has a shallow bottom box shape including a rectangular front plate and upper, lower, left and right bent portions bent rearward from four sides of the front plate, respectively. A water heater in which a drawn portion that has been subjected to a drawing process is formed until reaching a bent portion of at least one side,
In at least one bent portion that is reached by the narrowed portion, a bent portion other than the narrowed portion is formed in a chamfered shape.
In order to achieve the above object, the invention according to claim 2 has a housing for housing the combustion device, wherein the housing includes a box body having an open front surface, and a front cover attached to the front surface of the box body. And the front cover has a shallow bottom box shape including a rectangular front plate and upper, lower, left and right bent portions bent rearward from four sides of the front plate, respectively. A water heater in which a drawn portion that has been subjected to a drawing process is formed until reaching a bent portion of at least one side,
At least one side of the bent portion reached by the narrowed portion is characterized in that the radius of curvature of the bent portion other than the narrowed portion is larger than the radius of curvature of the bent portion from the narrowed portion.
In order to achieve the above object, the invention according to claim 3 is characterized in that a rectangular front plate is subjected to a drawing process in which a drawing portion reaches at least one of four peripheral sides thereof, and then the four sides are formed. Is a method for processing a front cover for a water heater with a shallow bottom box shape by bending each rearward to form a bent portion vertically and horizontally,
When the four sides are bent backward, at least one side reached by the narrowed portion is bent so that a bent portion other than the narrowed portion has a chamfered shape.
In order to achieve the above object, the invention according to claim 4 is that, after performing a drawing process in which a drawing portion reaches at least one of four sides around a rectangular front plate, the four sides are formed. A method for processing a front cover for a water heater that is bent rearward to form bent portions in the upper, lower, left and right directions to form a shallow bottom box,
When bending the four sides backward, at least one side reached by the narrowed portion is bent so that the radius of curvature of the bent portion other than the narrowed portion is larger than the radius of curvature of the bent portion from the narrowed portion. It is characterized by.

  ADVANTAGE OF THE INVENTION According to this invention, even if the front plate of a shallow-bottom box-shaped front cover is subjected to drawing to reach the bent portion, the difference in required bending length between the drawn portion and the non-drawn portion can be reduced. As a result, it is possible to prevent wrinkles from being generated in the vicinity of the narrowed portion, and it is possible to maintain the design without impairing the beauty of the front cover even at the bent portion.

It is a perspective view of a water heater. It is explanatory drawing of a water heater, (A) shows a front, (B) shows a side surface, respectively. It is explanatory drawing of a water heater, (A) shows a plane and (B) shows a bottom surface, respectively. It is a front view in the state where the front cover was removed. It is explanatory drawing of only a housing | casing, (A) shows a front, (B) shows the AA cross section, respectively. (A) is an enlarged view of a portion B in FIG. 5, and (B) is an enlarged view of a portion C. It is a perspective view of the cover main body of a front cover. In the explanatory view of the cover body, (A) shows the front, (B) shows the side, and (C) shows the back. In the illustration of the cover body, (A) shows a plane and (B) shows a bottom. (A) is an enlarged view of a part D in FIG. 7, and (B) is a sectional view of a bent portion. It is the perspective view of the housing | casing which supported the front cover shifted to the left and right from the box main body. It is a bottom view of the case which supported the front cover shifted to the left and right from the box main body. It is an enlarged perspective view of the upper part of the front cover of FIG. FIG. 13 is an enlarged perspective view of a lower portion of the front cover in FIG. 12. It is sectional drawing of the bending part which shows the example which changed the curvature radius between the recessed part and the front part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a perspective view showing an example of a water heater, FIG. 2A is a front view of the water heater, FIG. 1B is a side view, FIG. 3A is a plan view, and FIG.
The water heater 1 has a housing 2 including a box body 3 having five closed surfaces except the front surface, and a front cover 4 having a closed front surface of the box body 3. As shown in FIG. 4 with the front cover 4 removed, a combustion device 5 including a burner unit 6, a heat exchanger 7, and an exhaust hood 8 is installed in the housing 2 from below. An exhaust pipe 9 provided at the upper end of the box body 3 penetrates the upper plate 30 of the box body 3 and protrudes upward. At the top and bottom of the back of the box body 3, mounting brackets 10, 10 for installation on an indoor wall or the like are provided, and a plurality of air supply ports 11, 11,... ing.
A gas connection port 12 to which an external gas pipe is connected, a water supply port 13 to which an external water supply pipe is connected, and an external hot water supply pipe having a plurality of hot water taps are connected to the bottom surface of the box body 3. A hot water supply connection port 14 and a return connection port 15 are provided.

The burner unit 6 is connected to a gas pipe 16 connected to the gas connection port 12, and is provided with a fan 17 for supplying combustion air.
The heat exchanger 7 has a heat transfer tube 18 that penetrates a plurality of fins (not shown) in a meandering shape, and a water supply tube 19 connected to the water supply connection port 13 is connected to an input end of the heat transfer tube 18. A tapping pipe 20 connected to the hot water supply connection port 14 is connected to an outlet end of the heat transfer pipe 18. A circulation pipe 21 including a pump 22 is connected between the return connection port 15 and the water supply pipe 19.
That is, the water heater 1 heats the water supplied from the water supply pipe 19 by the heat exchanger 7 and discharges the water from the water discharge pipe 20, and operates the pump 22 to circulate the discharged hot water from the external hot water supply pipe. It is a circulation type in which the heat is returned to the water supply pipe 19 via the pipe 21 and reheated by the heat exchanger 7.

Then, as shown in FIG. 5, the box body 3 of the housing 2 is formed by joining an upper plate 30, a lower plate 31, left and right side plates 32, 32, and a back plate 33 made of metal to each other. At the front edge of the upper plate 30 forming the front opening, an upper bent piece 34 is formed to be bent inward (opening side) as shown in FIG. Also, laterally bent pieces 35, 35 that are bent inward are formed at the front edges of the left and right side plates 32, 32, respectively. At the boundary between the upper plate 30 and the upper bent piece 34, a pair of slits 36, 36 extending in the left-right direction are formed symmetrically.
Further, as shown in FIG. 6, the lower plate 31 is formed to be longer than the upper plate 30, and a receiving portion 37 is formed at a front end of the lower plate 31 so as to protrude forward beyond the front edge of the upper plate 30. The receiving portion 37 is formed with a pair of through holes 38 for screwing on the left and right.

On the other hand, the front cover 4 has a shallow bottom including a front plate 41 having a rectangular shape when viewed from the front, and bent portions 42 to 44 formed by bending the upper side, the lower side, and the left and right sides of the front plate 41 to the rear side. It has a box-shaped metal cover body 40. At the center of the front plate 41, a vertically long mirror 45 is fitted and fixed, and below the mirror 45, a cover 46 that opens and closes an operation panel (not shown) attached from the back side of the cover body 40 is provided. Therefore, as shown in FIGS. 7 and 8, a concave portion 47 for fixing the mirror 45 is formed in the cover main body 40 in a predetermined width in a vertical direction, and an operation panel is attached to a lower portion of the concave portion 47. Window 48 is formed.
A pair of claws 49, 49 which can be inserted from above into the slits 36, 36 provided in the box body 3, are formed at the rear end edge of the upper bent portion 42, respectively, so as to be bent downward.
Further, as shown in FIG. 9, a protruding portion 50 that protrudes rearward from the bent portions 42 and 44 on the upper side and the left and right side sides is formed at a central portion of the lower side bent portion 43 except for the left and right ends. The projecting portion 50 has a pair of screw holes 51, 51 corresponding to the through holes 38, 38 formed in the receiving portion 37 of the lower plate 31 of the box body 3.

Here, the concave portion 47 of the cover main body 40 is drawn along the entire vertical length of the front plate 41 so as to reach from the bent portion 42 on the upper side to the bent portion 43 on the lower side. In this case, since the height in the front-rear direction is different between the concave portion 47 and the front portions 52, 52 located on the left and right sides of the concave portion 47, if the bent portions 42, 43 are bent as they are, the excess sheet metal in the concave portion 47 will become In this case, the bent portions 42 and 43 are wrinkled from between the concave portion 47 and the front portion 52.
However, in the present embodiment, as shown in FIG. 10, when bending the bent portions 42 and 43, the bent portion 47A is formed in an arc shape in bending from the concave portion 47 to be drawn. In bending from the left and right front portions 52 that are not drawn, the bent portion 52A is not formed in the same arc shape as shown by a two-dot chain line in FIG. This difference in bending can be accommodated by the shape of the mold.
When the shapes of the bent portions 47A and 52A are changed in this way, the bending end of the bent portion 47A and the bent portion 52A does not largely shift. Therefore, the bent portions 42 and 43 can be formed between the concave portion 47 and the front portion 52 without wrinkles.

In the water heater 1 configured as described above, when attaching the front cover 4 to the box body 3, the claws 49, 49 provided on the bent portion 42 on the upper side of the front cover 4 are provided on the front surface of the box body 3. Into the slits 36, 36 formed from above. Then, the claws 49, 49 are locked to the upper plate 30, and the bent portion 43 on the lower side of the front cover 4 is placed on the receiving portion 37 of the lower plate 31 of the box body 3, and the front surface of the box body 3 is held. Supported in a closed state. In this state, the screw holes 51, 51 of the bent portion 43 are aligned with the through holes 38, 38 of the lower plate 31, and the screws 53, 53 are inserted into the through holes 38, 38 from below the lower plate 31, and the screw holes 51, 51 are inserted. Screw into 51. Thereby, the front cover 4 is fixed to the box body 3.
In this state, the screws 53, 53 are exposed only on the lower surface of the lower plate 31, so that they are not noticeable from the front and have excellent design. In addition, since the bottom surface of the front cover 4 is hidden from the lower plate 31, even if wrinkles or the like are generated on the bottom surface due to the bending process of the front cover 4 or the like, the bottom surface of the front cover 4 is not seen from the outside, and the design is not impaired.

  On the other hand, when removing the front cover 4 for maintenance or the like inside, if the screws 53 of the lower plate 31 are loosened and removed, the connection between the lower plate 31 and the bent portion 43 is released. However, the front cover 4 is maintained in a state in which the claws 49, 49 are engaged with the upper plate 30 and are placed on the lower plate 31, so that the front cover 4 does not come off or shift unexpectedly. Then, by lifting the front cover 4 upward and pulling out the claws 49, 49 from the slits 36, 36, the claws 49, 49 can be removed from the box body 3.

(Effect of the Invention According to the Front Cover Mounting Structure)
As described above, according to the water heater 1 of the above embodiment, the slit 36 is formed at the front end of the upper plate 30 of the box body 3, and the downward claw inserted into the slit 36 from above is formed at the upper end of the front cover 4. On the other hand, a receiving portion 37 is formed at the front end of the lower plate 31 of the box body 3 for receiving the lower surface of the front cover 4 with the claws 49 inserted into the slits 36. Since the lower surface of the front cover 4 is screwed from below, the screws 53 for attaching the front cover 4 are made inconspicuous, and the design can be improved. Further, the workability when removing the front cover 4 is improved, and the maintainability is also improved.

Note that the number, position, and shape of the slits provided in the box body are not limited to the above-described embodiments, and the number of slits may be increased and provided at equal intervals, or one slit may be formed to be longer in the left and right directions. The number and shape of the claws provided on the front cover may be changed according to the slit.
Also, the receiving portion provided on the lower plate can be appropriately changed, for example, by arranging a plurality of short receiving portions on the left and right at equal intervals.
Further, in the invention relating to the mounting structure of the front cover, the front cover does not need to be in the shape of a shallow box, and an L-shaped claw may be formed at the upper end edge of the plate-shaped front cover.

On the other hand, as shown in FIGS. 11 and 12, the lower end of the front edge of the side plate 32 of the box body 3 is inserted into the bent portion 43 on the lower side of the front cover 4 with one claw 49 inserted into the slit 36 on the left and right opposite sides. The cuts 54, 54 as locked parts to be locked (parts without the laterally bent pieces 35) can be formed from the rear end. In this case, the front cover 4 is shifted in the left-right direction by the insertion into the slit 36 by one of the claws 49 shown in FIGS. 11 and 13 and the engagement between the side plate 32 and the cut 54 shown in FIGS. Even at the position, it can be supported on the front surface of the box body 3. At this time, a gap is formed between the side plate 32 and the front plate 41 of the front cover 4 so that the harness connecting the controller on the box body 3 and the operation panel is not bitten.
Therefore, according to this modified example, the maintenance of the combustion device 5 can be performed while looking at the information on the operation panel, and the workability related to the maintenance is further improved. In addition, since the front cover 4 can be temporarily placed on the front surface of the box body 3, there is no problem with the place where the removed front cover 4 is placed.

(Effect of the invention relating to the bending of the front cover)
As described above, according to the method for processing the water heater 1 and the front cover 4 of the above-described embodiment, the bent portions 42 and 43 on the two sides reached by the narrowed portion (the concave portion 47) are bent from the non-drawn portion (the front portion 52). Since the portion 52A is formed to be chamfered, even if the front plate 41 of the shallow box-shaped front cover 4 is subjected to drawing to reach the bent portions 42 and 43, the recess 47 and the front surface 52 are formed. The difference in required bending length can be reduced. As a result, it is possible to prevent wrinkles from being generated in the vicinity of the concave portion 47, and to maintain the design without impairing the beauty of the front cover 4 even at the bent portions 42 and 43.

In the above-described embodiment, the bent portion on the side reached by the narrowed portion is formed so that the bent portion other than the narrowed portion has a chamfered shape. In addition, as shown in FIG. May be formed so that the radius of curvature R1 of the bent portion 52A from the front surface portion 52 is larger than the radius of curvature R2 of the bent portion 47A from the concave portion 47. Also in this case, the difference in required bending length between the concave portion 47 and the front surface portion 52 can be reduced, and wrinkles can be prevented from being formed in the vicinity of the concave portion 47.
In the above embodiment, the narrowed portion reaches the upper bent portion and the lower bent portion. However, when the narrowed portions reach the right and left bent portions, the bent portions are similarly formed into chamfered shapes. In addition, the generation of wrinkles can be prevented by changing the radius of curvature of the bent portion. The same applies to a case where the aperture portion reaches three or four sides instead of two sides of the front plate or a case where only one side reaches.

  In addition, common to each invention, the water heater itself is not limited to the above-described embodiment. Each invention can be adopted even if it has a composite type or the like.

  1. hot water heater, 2. housing, 3. box main body, 4. front cover, 5. combustion device, 6. burner unit, 7. heat exchanger, 30 upper plate, 31 ..Lower plate, 34..upper bent piece, 36..slit, 37..receiving part, 38..through hole, 40..cover body, 41..front plate, 42-45..bending part, 47.. Recess, 47A bent part, 49 nail, 50 projected part, 51 screw hole, 52 front surface, 52A bent part, 53 screw, 54 cut R1, R2 ... radius of curvature.

Claims (4)

A housing for housing the combustion device,
The housing comprises a box body with an open front, and a front cover attached to the front of the box body,
The front cover has a shallow bottom box shape including a rectangular front plate and upper, lower, left and right bent portions bent rearward from four sides of the front plate, and the front plate has a rearward side. A water heater in which a constricted drawn portion is formed until reaching the bent portion on at least one side,
The water heater according to claim 1, wherein a bent portion other than the narrowed portion is formed in a chamfered shape at the bent portion on the at least one side reached by the narrowed portion. A housing for housing the combustion device,
The housing comprises a box body with an open front, and a front cover attached to the front of the box body,
The front cover has a shallow bottom box shape including a rectangular front plate and upper, lower, left and right bent portions bent rearward from four sides of the front plate, and the front plate has a rearward side. A water heater in which a constricted drawn portion is formed until reaching the bent portion on at least one side,
At the bent portion of the at least one side reached by the narrowed portion, a radius of curvature of a bent portion other than the narrowed portion is larger than a radius of curvature of a bent portion from the narrowed portion. vessel. After performing a drawing process in which the drawing portion reaches at least one of the four sides around the rectangular front plate, the four sides are bent rearward to form bent portions vertically and horizontally. A method of processing a front cover for a water heater having a shallow box shape,
When bending the four sides backward, at least one side reached by the narrowed portion is bent so that a bent portion other than the narrowed portion has a chamfered shape. Processing method. After performing a drawing process in which the drawing portion reaches at least one of the four sides around the rectangular front plate, the four sides are bent rearward to form bent portions vertically and horizontally. A method of processing a front cover for a water heater having a shallow box shape,
When bending the four sides rearward, the radius of curvature of the bent portion other than the narrowed portion is larger than the radius of curvature of the bent portion from the narrowed portion on the at least one side reached by the narrowed portion. A method for processing a front cover for a water heater, comprising: bending the front cover.

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