JP4076519B2 - Electric water heater - Google Patents

Description

The present invention relates to an electric water heater having a metal vacuum double inner container, boiling a liquid in the inner container with a heater, and keeping warm.

Conventionally, as an electric water heater, a metal vacuum double inner container surrounded by an outer casing is provided, and only a bottom wall of the inner container is used as a single wall, and a sheet heater is stretched on the outer wall of the bottom, and the heater is pressed down. An electric hot water storage container having a structure in which a heater pressing plate is screwed to the bottom outer wall is disclosed in Japanese Patent Application Laid-Open No. 2002-325684 (see Patent Document 1, FIG. 1 and FIG. 13).

JP 2002-325684 A (FIGS. 1 and 13)

Hereinafter, a conventional electric water heater will be described with reference to FIGS.
The electric hot water storage container of Patent Document 1 is provided with a vacuum double container 3 surrounded by an outer case 2, the vacuum double container 3 is formed in a bottomed cylindrical shape, the bottom part is a single wall, and the body part is an inner part. One heater that has a vacuum double wall consisting of a cylinder 4 and an outer cylinder 5 and is provided in a narrow mouth with the upper end of the inner cylinder 4 at the mouth narrowed toward the inside center, boiling the liquid in the vacuum double container 3 and keeping it warm. 11 is stretched on the outer wall of the bottom of the vacuum double container, and a heat shield plate 87 is provided on the lower side of the heater 11, and a backup plate 92 and a spring member 91 are sandwiched between the heater 11 and the heat shield plate 87. The heat plate 87 is configured to be screwed 89 to a mounting bracket 88 on the bottom outer wall of the vacuum double container.

However, in this type of electric water heater, the screw that holds the heat shield on the bottom outer wall of the vacuum double container gradually loosens under the influence of heat and vibration, and the bottom outer wall of the vacuum double container and the heater are in poor contact. Thus, there is a problem that the liquid in the vacuum double container cannot be heated to a desired temperature.

Therefore, spot welding of this heat shield plate to the bottom outer wall of the vacuum double container was developed, but spot welding cannot be spot welded if there is an obstacle wall in the inner and outer vertical direction of the welding location. If the mouth of the double container is narrow, there is a problem that spot welding of the heat shield plate supporting the heater cannot be performed.

The present invention has a cylindrical shape with a bottom, a single wall at the bottom, a vacuum double wall at the body, an inner container 3 narrowed toward the inner center, and stretched on the bottom outer wall of the inner container 3, A planar heater 7 for heating the liquid in the inner container 3 is provided, fixed around the outer wall of the bottom of the inner container 3, and a heater pressing plate 11 for holding the heater 7 against the bottom of the inner container is provided. An exterior case 2 surrounding the trunk is provided, a shoulder member 5 is coupled to the upper end of the exterior case 2, and a lid 6 that opens and closes the mouth of the inner container is detachably attached to the upper end of the shoulder member 5. In the electric water heater 1 having the bottom member 4 coupled to the lower end and provided with a discharge mechanism 9 for discharging the liquid in the inner container to the outside, the planar heater 7 includes a main heater 7a for water heater, and a heat retention heater. The inner diameter of the bottom of the inner container is the minimum inner diameter near the mouth. Remote and small diameter, the heater pressing plate 11 has a configuration that spot welding around single-wall portion of the inner container bottom.

The present invention solves the conventional problems, can be reliably spot-welded in a state in which the mouth of the inner container is narrow, and can heat the liquid in the inner container to a desired temperature, heat retention effect and It is possible to control wasteful power consumption and improve efficiency.

The electric water heater 1 is coupled to the inner container 3 surrounded by the outer case 2, the lower end of the outer case 2, the bottom member 4 covering the bottom of the inner container 3, the upper end of the outer case 2, and the inner container 3 A shoulder member 5 that supports the mouth of the mouth, a lid 6 that is detachably attached to the center of the upper end of the shoulder member 5, opens and closes the mouth of the inner container 3, a heater 7 that heats the liquid in the inner container 3, and contents It comprises a temperature controller 8 that senses the temperature of the liquid in the container 3 and turns the heater 7 on and off, and a discharge mechanism 9 that discharges the liquid in the inner container to the outside.

The outer case 2 is made of a metal or a synthetic resin and is formed in a cylindrical shape with the front surface recessed inward, and has an inner diameter that allows the body of the inner container 3 to be freely inserted.

As shown in FIGS. 3 and 4, the inner container 3 is provided with a bottomed cylindrical inner wall 3a and a cylindrical outer wall 3b slightly larger than the inner wall 3a made of a metal material such as stainless steel. The bottom of the outer wall 3b is welded to the bottom outer wall away from the center of the bottom, the mouth of the outer wall 3b is welded to the mouth of the inner wall 3a, and the inner and outer walls are evacuated to form a single body vacuum at the bottom.

The inner wall 3a of the inner container 3 is provided with an annular inner wall projection 3c having a diameter smaller than the diameter of the body at the mouth, and an inner wall flange 3d extending outward is provided at the upper end of the annular inner wall projection 3c. An inner diameter R1 of the annular inner wall projection 3c of the inner wall 3a is formed to be larger than an outer diameter around a spot welded portion of a heater pressing plate 11 described later. Further, the inner diameter R1 of the annular inner wall projection 3c of the inner wall 3a is formed to be larger than the outer diameter R2 of the single wall portion of the bottom of the inner container 3.
The outer wall 3b of the inner container 3 is provided with an outer wall flange portion 3k on the outer side of the upper end of the mouth, is in contact with the inner wall flange portion 3d of the inner wall 3a, and is vacuum-sealed so as to wrap the inner wall 3a from the outer peripheral bottom wall 3h described later. It is heavy.

A bottom portion of the inner container 3 composed of the inner wall 3a and the outer wall 3b has a temperature controller abutting wall 3e that comes into contact with a temperature regulator 8 (described later) from the center, and a heater that comes into contact with the heater 7 around the temperature regulator abutting wall 3e. An abutting wall 3f, a heater pressing plate abutting wall 3g that comes into contact with the heater pressing plate 11, and an outer peripheral bottom wall 3h that is a double wall are formed in a stepped shape in order.
3j is a pipe-shaped lower cylinder that communicates with the inside of the inner container 3 and communicates with the outside, and hangs forward of the heater pressing plate abutting wall 3g of the inner wall 3a.

In addition, as shown in FIG. 5, the inner container 3 has the bottom of the inner wall 3a formed in the same shape as in FIG. 3, and is smoothly recessed toward the mouth of the inner wall 3a. It is formed in the same shape as in FIG. 3 and is smoothly recessed toward the mouth of the outer wall 3b. The inner diameter R1 of the mouth of the inner container 3 is formed to be larger than the outer diameter R2 of the single wall portion at the bottom of the inner container 3.

As shown in FIG. 6, the heater 7 that heats the liquid in the inner container 3 includes a heater cover 10 that covers the heater 7 and a heater pusher that fixes the heater 7 together with the heater cover 10 to the heater contact wall 3 f of the inner container 3. A plate 11 and a shield plate 12 which is screwed to the heater push plate 11 and does not allow the heat of the heater to escape to the outside of the bottom of the inner container are provided.

The heater 7 has a hollow in the center, and is provided with two phases of a main heater 7a for boiling water that heats the liquid in the inner container 3 to a boiling state and a sub-heater 7b for keeping warm, It is in contact with the heater contact wall 3 f of the inner container 3.

As shown in FIG. 6, the heater pressing plate 11 has a notch at the center, and a screw angle 13 is welded to the lower surface of the outer peripheral wall that contacts the heater pressing plate abutting wall 3g. The screw angle 13 is welded to the heater pressing plate as a pre-process before spot welding of the heater pressing plate 11.
The heater pressing plate 11 is spotted around the heater pressing plate abutting wall 3g of the inner container at an appropriate interval with the heater 7 and the heater cover 10 pressed against the heater abutting wall 3f of the inner container 3. Welding.

The shielding plate 12 is fixed to the screw angle 13 of the heater push plate 11 with a screw so that the heat of the heater 7 does not escape below the shielding plate as shown in FIG.

The bottom member 4 that covers the bottom of the inner container 3 is composed of a ring-shaped synthetic resin bottom plate 14 and a metal closing plate 15 that closes the central opening of the bottom plate 14.
The bottom plate 14 is composed of a body portion having the same shape as the cross-sectional shape of the exterior case 2 and a bottom portion having an open center, and a metal flat plate-like closing plate 15 is covered on the bottom portion.

The shoulder member 5 coupled to the upper end of the exterior case 2 is provided with an opening having an opening in the center up and down, a flange extending forward on the front surface of the opening, and a hinge on the rear surface of the opening. A flange extending toward the inner center is provided at the lower part of the peripheral wall forming the opening.

An L-shaped seal packing is stretched around the flange portion of the opening, and the outer wall flange portion 3k of the inner container 3 is in contact with the seal packing.
A lid 6 pivotally supported by the hinge portion of the shoulder member 5 is attached to the opening so as to be freely opened and closed.

The shoulder part of the shoulder member 5 is a cavity upward from the lower side. Water is boiled in the cavity, and a switch for keeping warm, a lamp, a discharge pipe of a discharge mechanism 9 to be described later, and the like are accommodated. A control board is provided on the upper surface with each switch, discharge switch, and the like displayed thereon.

The lid body 6 pivotally supported by the hinge portion of the shoulder member 5 includes an upper lid, a lower lid, and a metal cover plate that covers the lower surface of the lower lid and closes the opening of the member 5.

The temperature adjuster 8 is formed of a thermistor or the like, and is fixedly held by the shielding plate 12 in contact with the temperature adjuster contact wall 3 e of the inner container 3. The temperature controller 8 senses the liquid temperature in the inner container 3 and turns the heater 7 on and off by computer control. The base for computer control is disposed between the inner container 3 and the bottom member 4, and the computer is controlled by the operation of the control plate displayed on the front upper surface of the buttock of the shoulder member 5, and the heater 7 and the discharge described later are performed. The mechanism 9 is operating.

As shown in FIGS. 1 and 2, the discharge mechanism 9 is located between the discharge pump 16 and the interlocking pump 17, between the interlocking pump 17 that sucks up the liquid in the inner container 3 and discharges it from the tip of the discharge pipe 16 to the outside. A liquid amount display pipe (not shown) for displaying the amount of liquid in the container 3, and between the liquid amount display pipe and the discharge pipe 16, the liquid in the liquid amount display pipe at the time of falling is stopped and the liquid flows out from the discharge pipe 16. And an overturning water valve portion 18 for preventing the above, and a joint pipe (not shown) for connecting the lower cylinder 3j of the inner container 3 and the interlocking pump 17 to each other.

In this way, with respect to the inner diameter R1 close to the mouth of the inner container 3, the outer diameter R2 of the heater pressing plate abutting wall 3g which is the outermost portion of the single portion is reduced to ensure spot welding of the heater pressing plate 11. At the same time, the heater 7 is arranged in two phases of the main heater 7a and the sub heater 7b in spite of the small outer diameter R2 of the heater pressing plate abutting wall 3g. The supply of unnecessary power consumption is controlled, and a more efficient electric water heater can be obtained.

Although the embodiments considered to be representative of the present invention have been described above, the present invention is not necessarily limited only to the structures of these embodiments, and includes the above-described constituent features according to the present invention and also refers to the present invention. The present invention can be carried out with appropriate modifications within the scope of achieving the object and having the effects referred to in the present invention.

The longitudinal cross-sectional view of this invention Example. The bottom view of an example of the present invention. The longitudinal cross-sectional view of the inner container of this invention Example. The bottom view of the inner container of this invention Example. The longitudinal cross-sectional view of another inner container of this invention Example. The disassembled perspective view which shows the heater part of this invention Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electric water heater 2 ... Outer case 3 ... Inner container 3a ... Inner wall 3b ... Outer wall 3c ... Annular inner wall protrusion part 3d ... Inner wall flange part 3e ... Temperature controller contact wall 3f ... Heater contact wall 3g ... Heater pushing plate contact Wall 3h ... Outer peripheral bottom wall 3j ... Lower cylinder 3k ... Outer wall flange 4 ... Bottom member 5 ... Shoulder member 6 ... Cover 7 ... Heater 7a ... Main heater 7b ... Sub heater 8 ... Temperature controller 9 ... Discharge mechanism 10 ... Heater cover DESCRIPTION OF SYMBOLS 11 ... Heater pushing plate 12 ... Shielding plate 13 ... Screw angle 14 ... Bottom plate 16 ... Discharge pipe 17 ... Interlocking pump R1 ... Minimum inner diameter R2 near the mouth ... Outer diameter of the single part of the bottom

Claims (1)

A bottomed cylindrical shape with a single wall at the bottom, a vacuum double wall at the body, an inner container (3) narrowed with the mouth facing the inner center, and stretched on the bottom outer wall of the inner container (3), A planar heater (7) for heating the liquid in the inner container (3) is provided, fixed around the bottom outer wall of the inner container (3), and a heater pusher that holds the heater (7) against the bottom of the inner container. A plate (11) is provided, an outer case (2) surrounding the trunk of the inner container is provided, a shoulder member (5) is coupled to the upper end of the outer case (2), and the inner container is attached to the upper end of the shoulder member (5). A lid (6) for opening and closing the mouth is detachably mounted, a bottom member (4) is coupled to the lower end of the outer case (2), and a discharge mechanism (9) for discharging the liquid in the inner container to the outside is provided. In the electric water heater (1), the planar heater (7) includes a main heater (7a) for water heater and a sub heater (7) for heat insulation. And a single wall portion at the bottom of the inner container having a diameter smaller than the minimum inner diameter near the mouth, and the heater pressing plate (11) is spot-welded around the single wall portion at the bottom of the inner container. Electric water heater.

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