JPS5812675Y2 - Electric water heater safety device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a safety device for an electric water heater having a hot plate having a heat generating element crimped and fixed thereto.

Generally, in this type of safety device, a temperature fuse is attached to a heat plate to which a heating element is crimped and fixed via an insulating material, and when the heating element generates abnormal heat due to a malfunction such as a thermostat, the force from this heating element causes the temperature to rise. The temperature fuse is blown by the rising conductive heat from the hot plate, and the temperature is prevented from rising any further.

However, the above-mentioned safety device has the problem that sufficient safety cannot be ensured if it is used for a long period of time.

In other words, the degree of compression of a heating element that is crimped and fixed to a hot plate decreases due to repeated expansion and contraction each time it is used, and over a long period of time, the degree of adhesion between the hot plate and the heating element becomes extremely poor, causing the heating element to malfunction. Even if heat is generated, the heat will not be transferred to the hot plate.

In such a situation, the temperature fuse attached to the heating plate will continue to flow current without blowing out even if the heating element generates abnormal heat, resulting in a fire.

The present invention is designed to ensure that the temperature fuse blows even in such a situation, and is intended to improve reliability.

An example of this will be described below using a safety device for a water heater for boiling coffee as an example.

In the figure, reference numeral 1 denotes the main body of the coffee brewer, and a water storage tank 3, which can be opened and closed by a lid 2, is erected on the negative side.

A hot plate 5 in which a water pipe 4 is embedded is disposed in the remaining part of the coffee boiler main body 1, and its upper plate 6 serves as a heat insulating plate part.

Note that one end of the water pipe 4 is connected to the water storage tank 3 via a check valve 7, and the other end 4a is opened onto a glass container 8 placed on the heat insulating plate portion 6.

A coffee basket 9 is installed above the glass container 8.

10 is a filter, 11 is a coffee bean, and 12 is a diffusion plate.

Reference numeral 13 denotes a heating element such as a sheathed heater, which is disposed in a substantially U-shape substantially parallel to the water pipe 4 and interlocked with the hot plate 5.

Reference numeral 14 denotes a thermostat attached to the protrusion of the heating plate 5 on the outside of the water pipe 4, and a terminal 14 is connected between the thermostat 14 and one raised terminal 13a of the heating element as shown in FIG. A temperature fuse 15 is connected to the heating element 13, the water pipe 4, and the hot plate 5 on a horizontal plane, intersecting the heating element 13 and the water pipe 4 with a gap t between them.

In the above configuration, the temperature of the temperature fuse 15 is maintained at an appropriate temperature by water flowing from the water storage tank 3 into the water pipe 4 when boiling water, but rises rapidly when the water in the water pipe 4 runs out after boiling.

Normally, the thermostat 14 is activated before the temperature of the temperature fuse 15 rises rapidly, but when the temperature fuse 15 malfunctions, the temperature rise is sensed and the thermostat 14 is blown to cut off the current supply.

Furthermore, due to long-term use, the heating element 13 and the heating plate 5 repeatedly expand and contract, reducing the degree of adhesion between them and reducing heat conduction to the heating plate 5. The heating element 13 reaches an abnormal temperature, but at this time the temperature fuse 15 blows due to the direct radiant heat from the heating element 13, cutting off the electricity to the heating element 13, and similarly to the above, preventing ignition or fire from the device. It is something.

Furthermore, the temperature fuse 15 is connected on a horizontal plane between the thermostat 14 fixed to the hot plate 5 and the raised terminal of the heating element 13, and is integrated into the hot plate 5, so that it can be easily incorporated into the coffee boiler main body 1. This not only improves work efficiency, but also reduces the variation in the position of the temperature fuse 15 when attached to the hot plate 5, further increasing the reliability of preventing excessive temperature rise.

In this way, according to the present invention, even if the temperature of only the heating element rises abnormally due to long-term use, the temperature fuse will detect this and will surely blow it out.
Its reliability is dramatically improved, such as by eliminating the possibility of causing a fire.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a coffee boiler employing a safety device according to an embodiment of the present invention, FIG. 2 is a bottom view showing the main parts thereof, and FIG. 3 is a side view of the same. 4...Water pipe, 5...Heating plate, 13.
... Heating element, 14 ... Thermostat,
15...Temperature fuse, t...Gap.

Claims (1)

[Scope of utility model registration request] A heating element is crimped and fixed to a heating plate equipped with an abbreviated water pipe approximately parallel to this water pipe, and a thermostat is attached to the heating plate outside of this heating element, and the thermostat and heating element are connected together. A safety device for an electric water heater, characterized in that a temperature fuse is disposed between one terminal and intersecting the heating element and the water pipe with a gap therebetween.