JPS6311890B2 - - 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.

Conventional structure and problems thereof Conventionally, the bottom of this type of container has been constructed by overlapping a cylinder 31 and a bottom plate 32, as shown in FIG. 1, and welding the end 33 to the base metal. In this case, a V-shaped gap 34 is created in the overlapping part, so even if stainless steel material is used, if water is boiled, etc., corrosion will occur in the gap 34, and the flat part of the bottom plate 32 will be deformed by the heat during welding, resulting in a loss of flatness. It had the disadvantage of being difficult to release.

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. 3, but in this case, as shown in FIG. As the wall thickness of the welded part 36 is thinner than other parts, minute cracks are likely to occur during cooling after welding, and this welded part is easily corroded. Due to the gaps, holes are likely to occur during electric arc welding, making the work extremely difficult, and the bottom plate 3
The problem was that the deformation of the planar portion of No. 2 was even larger.

Purpose of the Invention The present invention aims to provide a container that can easily and reliably weld the container body and bottom plate, has improved corrosion resistance, is free from distortion due to heat during welding, and can easily adjust the temperature of the liquid inside. be.

Structure of the Invention The present invention provides a container body formed by bending the lower end of a cylindrical body inward at a bending radius R to form a flange portion;
The bottom plate has a substantially dish-like shape and has a depth H consisting of a flat part, an inclined side wall, and an upright side wall, and the bottom plate is attached to the end of the flange part of the container body so that the end face of the upright side wall of the bottom plate protrudes outward. The intended purpose is achieved by fitting from the outside, welding this fitting part to the base metal, and setting the relationship between the bending radius R of the cylinder and the depth H of the bottom plate to be R<H. It is something.

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

In FIGS. 4 to 7, 1 is an outer body, and a stepped portion 3 of a spout 2 placed on the upper end of this outer body 1.
A cylindrical container 5 with a bottom is inserted through a rubber packing 4.
is attached, 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 and maintains a constant temperature.
Reference numeral 12 denotes an upper lid, in which a bellows pump 13 is installed, air pressed by a push plate 14 is sent into the container 5 through an inner lid 15, and hot water in the container 5 is pumped through a suction pipe 16 and a discharge pipe 17. It is structured so that it pours out through the water. A seal packing 18 connects the bellows pump 13 and the inner lid 15 in an airtight manner.

The container 5 has a container body 21 having a flange portion 20 formed by rolling plate material into a cylindrical shape, arc welding the seam 19, and bending the entire circumference of the lower end surface inward to form an L-shaped cross section with a radius R. , is formed from a bottom plate 22 formed of a plate material into a substantially dish shape. This bottom plate 2
2 is a flat part 22a, an inclined side wall 23 and an upright side wall 24
and has a depth H. Container body 2
1 and the bottom plate 22, as shown in FIG.
The vertical side wall 24 is press-fitted, and the upper end surface 24a of the vertical wall 24 is made to protrude from the flange portion 20 to form a protruding part 28, and the welding torch 26 is positioned at this fitted part to generate an arc. When the end face 24a of the vertical side wall 24 melts, the flange portion 2
The end face 25 of 0 is also melted and welded to the base metal in the shape shown in FIG. The wall thickness A of the welded part 27 is the thickness of the bottom plate 2.
The material of the protruding part 28 of which the vertical side wall 24 of No. 2 protrudes from the flange part 20 flows and is formed thicker than the other parts.

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 corner portion of the bottom plate 22 has an inclined side wall 24, it serves as a guide when the bottom plate 22 is press-fitted to the end portion 25 of the flange portion 20, making the work simple and reliable. Connect the bottom plate 22 to the container body 21
When welding, as shown in FIG. 8, since the entire depth H of the bottom plate 22 is formed by the inclined side wall 23 and the vertical side wall 24, the inclined side wall 23 is welded by the lower surface welding jig 29a and the upper surface welding jig 29b. can be pressed. That is, the container body 21 and the bottom plate 2 are welded together by welding jigs 29a and 29b on both the lower and upper surfaces of the container body 21 and the vertical side wall 24, which are to be melted and joined.
2 is pressed and fixed.

As a result, it is possible to restrict heat from the welded portion 27 from being conducted to other parts, and welding defects due to fitting gaps do not occur. Further, thermal deformation of the flat portion 22a of the bottom plate 22 can be prevented.

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 minimized without being affected by heat during welding. For this reason, as shown in FIG. 4, a temperature controller such as a thermal reed switch 11 is provided in close contact with the flat part 22a, and
When the heating element 9 is attached to the lower end R end point of the container body 21, the flat part 22a, which is the sensitive surface, is located above the lower end of the heating element 9, so the temperature of the flat part 22a changes from the hot water temperature due to the convection of the hot water. They are almost equivalent, and as a result,
Water temperature can be controlled reliably and with little variation.

Also, as shown in FIG. 8, the vertical side wall 24 of the bottom plate 22
The welding part 27 is fitted with the end face 24a facing the outer surface of the container body 21, and a hole 30 for supplying inert gas such as argon is provided in the lower surface welding jig 29a, and the welding part is filled with the welding part. No oxide film is formed on the inner surface 27a, and 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 great. Furthermore, when used as a container for boiling water, the sloped side wall 23 is formed to facilitate cleaning when removing water scale from the inner bottom surface of the container 5.

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

Effects of the Invention As is clear from the above description, the container such as a water heater of the present invention has the following effects. Since the generally dish-shaped bottom plate consisting of a flat part and an inclined side wall is welded to the container body, fitting and assembly is easy and reliable welding is possible, and thermal deformation of the flat part of the bottom plate to which control parts etc. are attached can be reduced. In addition, when the heating element is attached to the bottom R end point of the container body, the flat part, which is the sensing surface, is located above the bottom end of the heating element, so the temperature of the flat part becomes approximately equal to the temperature of the hot water due to the convection of the hot water. As a result, the hot water temperature can be controlled reliably and with little variation. In addition, when removing water scale from the inner bottom surface of the container, since the container body has an R section and the bottom plate has an inclined wall, it is easy to clean the container.

Furthermore, since the end face of the vertical side wall is welded so as to protrude outward from the flange portion, the thickness of the welded portion is increased, and as a result, welding cracks are eliminated and a container with good corrosion resistance is obtained.

[Brief explanation of the drawing]

1, 2, and 3 are partial sectional views of a conventional container, and FIG. 4 is a partially cutaway sectional view of an electric water heater using a container showing an embodiment of the present invention. Figure 5 is a perspective view of the same container, Figure 6 is an enlarged sectional view of the main part showing one manufacturing process of the same container, Figure 7 is an enlarged sectional view of the main part of the same container after welding, and Figure 8 is an enlarged sectional view of the main part of the same container after welding. FIG. 2 is an enlarged sectional view of a main part showing an example of a jig contact configuration during welding. 5... Container, 20... Flange part, 21... Container body, 22... Bottom plate, 22a... Plane part, 23... Inclined side wall, 24... Vertical side wall, 25... End face, 26... Welding torch, 27... Welding part, 28... Protrusion Department.

Claims (1)

[Claims] 1. It has a container body formed by bending the lower end of a cylinder inward with a bending radius R to form a flange portion, and a bottom plate having a depth H and having a substantially dish shape and consisting of a flat portion, an inclined side wall, and an upright side wall, At the flange end of the container body,
The bottom plate is fitted from the outside so that the end face of the vertical side wall of the bottom plate protrudes outward, and this fitting part is welded to the base metal, and the relationship between the bending radius R of the cylinder and the depth H of the bottom plate is set to R. <A container such as a water heater characterized by being set to H.