JPS624269Y2 - - Google Patents

Description

[Detailed Description of the Invention] Field of the Invention The present invention relates to an electric water heater, and particularly to an electric water heater equipped with a vacuum insulation layer with a vacuum chamber formed between a metal inner cylinder and an outer cylinder.

Conventional technology and its problems In general, vacuum double containers are far superior to single-layer thermal containers using insulating materials such as glass wool in terms of heat retention performance. Natural cooling is inevitable. Therefore,
A part of the conventional metal vacuum double container has been changed to a single layer structure,
An electric water heater has been proposed in which a heater is attached to this single portion to heat the liquid inside.

However, in this case, a double part and a single part must be formed in a single metal container, which is not only difficult to manufacture, but also causes heat from the heater to pass through the single part to the wall of the vacuum insulation layer. This causes the wall surface to become hot and generate gas (for example, _H2 gas) from the wall surface, lowering the degree of vacuum and lowering the heat retention performance. This is what is called vacuum blur.

Purpose of the invention The present invention was devised in view of these conventional problems.The purpose of the invention is to simplify manufacturing and prevent vacuum blurring by preventing the heat of the heater from being transmitted to the wall surface of the vacuum insulation layer as much as possible. An object of the present invention is to provide an electric water heater whose heat retention performance does not deteriorate.

Structure of the Invention In order to achieve the above object, the present invention forms a flange at the bottom of the vacuum insulation layer, and watertightly connects the upper edge of the heater equipped with the heater with the flange through an insulating spacer. This is what I did.

Embodiments Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of the present invention, in which 1 is a cylindrical vacuum insulation layer with a vacuum chamber 4 between a metal inner cylinder 2 and a metal outer cylinder 3; An annular metal support plate 6 having a flange 7 is closely fixed to the lower inner surface by welding or brazing. Reference numeral 8 denotes a bottomed metal heater having a band-shaped heater 9 attached to its outer peripheral surface, and an outer flange 10 is formed at the upper peripheral edge of the heater 8. Three members, a silicone rubber ring 11, a ceramic ring 12, and a fluorine rubber ring 13 constituting a spacer, are clamped and fixed between the lower surface of the flange 7 and the upper surface of the outer flange 10. 10 is sealed watertight. Reference numeral 14 denotes a tightening body, which has a male thread 15 on its outer circumferential surface that is threadedly engaged with a female thread 5 on the inner surface of the lower end of the inner cylinder 2. By screwing this male screw 15 into the female screw 5, the bottom surface of the heater 8 is covered with a heat insulating material 16 such as asbestos.
The spacer sandwiched between the flange 7 and the outer flange 10 is crimped.
Note that 17 is a heat insulating material such as glass wool that insulates between the heater 9 and the vacuum heat insulating layer 1, and 18 is a temperature regulator.

In the electric water heater configured as described above, the content liquid stored inside is heated by the heater 9 of the heater 8 and kept warm by the vacuum heat insulating layer 1 covering the outer periphery. At this time, the heat of the heater 9 attempts to be transmitted to the inner cylinder 2 of the vacuum insulation layer 1 via the heater 8 and the support plate 6, but there is a spacer between the heater 8 and the support plate 6 that has heat insulating properties. 11, 12, and 13, the heat of the heater 8 is hardly transmitted to the support plate 6, and the inner cylinder 2 of the vacuum insulation layer 1 does not reach a high temperature. Therefore, gas is not generated from the wall surface of the inner cylinder 2, and vacuum blur can be prevented.

In addition to the spacer composed of three layers of silicone rubber ring 11, ceramic ring 12, and fluoro rubber ring 13 as in the above embodiment,
It may be only the fluoro rubber ring 13, only the silicone rubber ring 11, or a combination of these two.

In addition, the method of connecting the tsuba 7 and the outer tsuba 10 is as follows:
In addition to crimping with the tightening body 14 as described above, for example, nut fittings may be vertically installed at several locations on the lower surface of the flange 7, screw insertion holes may be provided in the outer flange 10, and the screws may be inserted into the screw insertion holes. The connection may be made by screwing onto a nut fitting through the thread.

FIG. 2 shows a second embodiment of the present invention, in which a flange 7 is integrally formed on the outer periphery of the lower end of the vacuum insulation layer 1, and this flange 7 and the outer flange 10 of the heater 8 are connected by a heat insulating spacer 19.
It is tightened and fixed with bolts 20 with . In this case as well, the heat of the heater 9 is blocked by the spacer 19 and is not transmitted to the vacuum heat insulating layer 1.

Effects of the invention As is clear from the above explanation, according to the invention, the flange provided at the bottom of the vacuum insulation layer and the outer flange of the heater are connected via an insulating spacer. Therefore, the heat of the heater is not directly transmitted to the wall surface of the vacuum insulation layer, and vacuum blur can be effectively prevented, and manufacturing is extremely simple.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a first embodiment of an electric water heater according to the present invention, and FIG. 2 is a sectional view of a second embodiment. 1... Vacuum insulation layer, 2... Inner cylinder, 3... Outer cylinder,
4... Vacuum chamber, 7... Tsuba, 8... Heater, 9...
Heater, 10... Sototsuba, 11, 12, 13, 19
……Spacer.

Claims (1)

[Scope of utility model registration request] A flange is formed at the bottom of a cylindrical vacuum insulation layer with a vacuum chamber between the metal inner cylinder and the outer cylinder, and an outer flange is formed at the upper edge of the bottomed heater equipped with the heater, An electric water heater characterized in that the flange and the outer flange are watertightly connected with a spacer made of a heat insulating material in between.