JPH0416270B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a container for a water heater or the like.

BACKGROUND ART Conventionally, as shown in FIG.
were welded to the base metal.

Problems to be Solved by the Invention In such a conventional configuration, a V
Because a letter-shaped gap 34 is created, even when stainless steel material is used, the gap 34 is created when boiling water, etc.
At the same time, the flat part of the bottom plate 32 is deformed by the heat during welding, making it difficult to maintain flatness.Also, an oxide film is formed on the inner surface of the container, which requires surface finishing, which reduces cost. It also had the disadvantage of being expensive.

In addition, in order to eliminate crevice corrosion, there was a method of abutting the flange portion 35 of the cylinder 31 and the end face of the bottom plate 32 and welding this abutted portion, as shown in FIG. 2, but in this case, as shown in FIG. As shown in Fig. 3, the wall thickness of the welded part 36 is thinner than other parts, so minute cracks are likely to occur during cooling after welding, and as a result, this welded part is easily corroded. Due to thermal deformation during welding, holes are likely to occur during electric arc welding due to gaps, making the work extremely difficult.In addition, the deformation of the flat part of the bottom plate 32 becomes even greater due to welding, and the formation of an oxide film cannot be prevented. It had

An object of the present invention is to provide a container such as a water heater that solves these problems.

Means for Solving the Problems In order to solve the above problems, the present invention provides a container body formed by bending the lower end of a cylindrical body inward to form a flange portion, and a substantially dish-shaped flat plate portion that stands up on the outer periphery. and a bottom plate provided with a side wall, and the bottom plate is fitted from the outside so that a protruding portion of an end surface of the vertical side wall of the bottom plate protrudes outward from the end of the flange portion near the flange portion of the container body and the flat plate portion of the bottom plate. The fitting portion is welded from the outside.

Effects According to the above configuration, the bottom plate is fitted from the outside so that the vertical side wall side of the bottom plate protrudes outward from the flange end of the container body, making the fitting assembly easy and reliable. Welding is possible, and since the welding jig is pressed tightly against the inner surface of the container except for the welded part, it is possible to press and cool the area other than the fitting part between the flange end and the bottom plate, thereby preventing the formation of an oxide film. As a result, an advantageous product can be obtained in terms of cost.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 4 to 7.

4 to 7, 1 is an outer body, and a bottomed cylindrical container 5 is attached to a stepped portion 3 of a spout 2 placed on the upper end of the outer body 1 via a rubber packing 4. and a mounting bracket 6 is screwed to the bottom cover.

8 is a water level gauge provided through the side wall of the container 5, and 9 is a heating element attached to the lower outer surface of the container 5, which has a hot water heating circuit and a heat retention heating circuit. 10 is a thermostat that controls the energization of the water heating circuit, and 11 is a thermal reed switch that controls the heat generating circuit to maintain a constant temperature. 12
is an upper lid with a bellows pump 13 inside,
Air pressed by the push plate 14 is sent into the container 5 through the inner lid 15, whereby the hot water in the container 5 is poured out through the suction pipe 16 and the discharge pipe 17.

A seal packing 18 connects the bellows pump 13 and the inner lid 15 in an airtight manner.

The container 5 is made into a cylindrical shape by rolling a plate material,
It is formed by a container body 21 having a flange portion 20 whose seam 19 is arc welded and whose entire lower end surface is bent inward to have an L-shaped cross section, and a bottom plate 22 which is a plate material formed into a substantially dish shape. ing. This bottom plate 22 has a flat portion 22a, an inclined side wall 23, and an upright side wall 24. As shown in FIG. 6, the container body 21 and the bottom plate 22 are connected by press-fitting the vertical side wall 24 of the bottom plate 22 to the end surface 25 of the flange portion 20 of the container body 21 from the outside, and also by press-fitting the vertical side wall 24 of the bottom plate 22 from the outside. is made to protrude outward from the flange portion 20 to form a protruding portion 28, and when the welding torch 26 is positioned opposite to the upper end surface 24a of the upright wall 24 and an arc is generated, the upper end surface 24a of the upright side wall 24
is melted, and the end face 25 of the flange portion 20 is also melted, and the base metal is welded into the shape shown in FIG. The wall thickness A of the welded portion 27 is formed so that the material of the protruding portion 28 where the vertical side wall 24 of the bottom plate 22 protrudes from the flange portion 20 flows and is thicker than the thickness of the other portions.

Therefore, there are no gaps on the inner surface of the container 5 that cause corrosion as in the conventional example, and since the container 5 has a sufficient wall thickness, welding cracks do not occur when melting and solidifying.

Further, since the bottom plate 22 has an inclined side wall 23 at the corner portion, it serves as a guide when the bottom plate 22 is press-fitted to the end face 25 of the flange portion 20, so that the work is simple and reliable. Connect the bottom plate 22 to the container body 2
When welding to the bottom plate 2, as shown in Figure 8,
Since the total depth H of 2 is formed by the inclined side wall 23 and the vertical side wall 24, the inclined side wall 23 can be pressed by the lower surface welding jig 29a and the upper surface welding jig 29b. That is, the container body 2 is welded by welding jigs 29a and 29b on both the lower and upper surfaces of the flange 20 and the vertical side wall 24 to be melted and joined.
1 and the bottom plate 22 are pressed and fixed.

As a result, it is possible to restrict heat from the welded portion 27 from being conducted to other parts, and as a result, welding defects due to fitting gaps do not occur. Also, the flat part 22 of the bottom plate 22
It is also possible to prevent thermal deformation of a.

Furthermore, even if the depth H of the bottom plate 22 is increased to increase the deformation strength, if the height of the vertical side wall 24 is restricted, the deformation of the flat portion 22a can be made extremely small without being affected by heat during welding. For this reason, as shown in FIG. 4, since a temperature controller such as a thermal reed switch 11 is provided in close contact with the flat portion 22a, the hot water temperature can be controlled reliably and with little variation.

Further, as shown in FIG. 8, the vertical side wall 2 of the bottom plate 22
The upper end surface 24a of 4 is fitted with the upper end surface 24a protruding outward from the container body 21, and the lower surface welding jig 29a is provided with a hole 30 for supplying an inert gas such as argon to the inner surface of the fitting portion to be welded. By filling and welding, an oxide film is not formed on the inner surface 27a of the welded portion 27, and as a result, surface treatments such as chemical polishing and electrolytic polishing are not required, resulting in lower costs. Particularly in this case, since the inclined side wall 23 of the bottom plate 22 is pressed and cooled by both the lower and upper welding jigs 29a and 29b, the effect of preventing the formation of an oxide film is large. Moreover, when used as a container for boiling water,
Since the inclined side wall 23 is formed when removing water scale from the inner bottom surface of the container 5, it also has the effect of making cleaning easier.

In addition, as the plate materials of the container body 21 and the bottom plate 23,
If a stainless steel sheet containing 0.5-2.5% molybdenum and 0.2-1.0% niobium or titanium is used with ultra-low carbon ferritic stainless steel containing 15-20% chromium at 0.02% or less, it will be difficult to heat during welding. This has the effect that corrosion resistance does not deteriorate even if it is damaged.

Effects of the Invention As is clear from the description of the above embodiments, the container such as a water heater of the present invention has the following various excellent effects.

(1) The bottom plate is fitted from the outside so that the end of the vertical wall of the bottom plate protrudes outward to the end of the flange formed by bending the container body inward, making fitting and assembly easy. allows reliable welding. There is also no damage to the inner surface of the container body.

(2) Fit the bottom plate from the outside to the flange end of the container body so that the end of the vertical side wall of the bottom plate projects outward, and position the welding torch opposite to the end of the vertical side wall that projects outward. At the same time, the welding jig is pressed tightly to the area near the fitting part on the inner surface of the container, excluding the welded part, so that the part other than the fitting part is completely pressed with the welding jig. Since it can be cooled, it is also possible to prevent the formation of an oxide film on the inner surface of the container during welding. As a result, an inexpensive container can be provided without requiring surface finishing such as chemical polishing or electrolytic polishing.

(3) If the end face of the vertical side wall of the bottom plate is welded so as to protrude outward from the flange of the container body, the thickness of the welded part will be thicker, so welding cracks will not occur and a container with high corrosion resistance will be obtained.

[Brief explanation of drawings]

1, 2, and 3 are partial sectional views of a conventional container, FIG. 4 is a partially cutaway sectional view of an electric water heater using a container showing an embodiment of the present invention, and FIG. The figure is a perspective view of the same container, Figure 6 is an enlarged cross-sectional view of the main part showing one manufacturing process of the same container, Figure 7 is an enlarged cross-sectional view of the main part of the same container after welding, and Figure 8 is a welded part of the same container. FIG. 2 is an enlarged cross-sectional view of a main part showing an example of a jig contact configuration at the time of the present invention. 5...Container, 20...Flange portion, 21...Container body, 22...Bottom plate, 24...Vertical side wall, 25...
... end face, 26 ... welding torch, 27 ... welding part,
29a, 29b...Welding jig.

Claims (1)

[Claims] 1 The container body has a flange portion formed by bending the lower end of the cylindrical body inward, and a bottom plate that is approximately dish-shaped and has a vertical side wall on the outer periphery of the flat plate portion, and the flange portion of the container body and the bottom plate are The bottom plate is fitted from the outside to the end of the flange near the flat plate parts so that the protruding part of the end surface of the vertical side wall of the bottom plate protrudes outward, and the fitting part is welded from the outside. container.