JPS6326518B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a submersible heating element used in electric water heaters, etc., which controls the temperature of a heated object in a container using a single thermostat, and also controls the temperature of a heated object in a container when the heating element is dry energized. This detects a rise in temperature and opens the energizing circuit to prevent the heat generating element itself from being damaged due to disconnection or abnormal heat generation, while at the same time making it easy to attach and detach the thermostat.

An embodiment of the present invention will be described below with reference to the accompanying drawings. In the figure, 1 is a submersible heating element, which is composed of the following members. 2 is an upper seam plate, and a spring fitting 3 (threaded in two places) is spot welded to the back side of the central part, and a thermostat 4 is thermally pressed and held by a spring 5 and a screw 6. A side wall 2b is formed on the outer periphery.

7 is an upper insulating material such as a heat-resistant mica board or an inorganic insulator, 8 is a main heating plate in which a heating wire 8d is wound around an insulating material 8c, and a heating circuit with a large power consumption of 300 to 1000 W is formed; 9 is a main heating plate. Medium insulation material such as mica board, 10
Wrap the heating wire 10d around the insulating plate 10c, and
The auxiliary heat generating plate 11 is a lower insulating material such as a mica plate, which forms a heat generating circuit with low power consumption of 100W, and the upper insulating material 7, the main heat generating plate 8, the middle insulating material 9, the auxiliary heat generating plate 10, and the lower insulating material. The materials 11 are laminated to insulate the main heat generating plate 8 and the auxiliary heat generating plate 10, and form the heat generating member 12.
is formed. 13 is a heat shield plate made of a metal with low conductivity such as a stainless steel plate or an iron plate, and has a thickness of 0.2 to 0.8 mm.

14 is a hollow cylindrical fixture, and the main part is located in the center.
through holes 14a for leading out the auxiliary heating plates 8, 10 and the lead wires 8a, 10a, 4a of the thermostat 4;
It has a mounting flange 14b and a threaded portion 14c. The through hole 14a is large enough for the thermostat 4 and the presser spring 5 to move in and out, and the screw 6 can be tightened and removed freely from the opening. Reference numeral 15 designates a lower seam plate, which has a stepped portion 1 in the center of which the mounting flange 14b of the fixture 14 engages.
5a, a through hole 15b, and a plurality of bulges 15c, and the side wall 2b of the upper seam plate 2 is provided on the outer periphery.
A side wall 15d is provided which mates with the side wall 15d.

Each of the above-mentioned members is constructed by sequentially stacking the upper seam plate 2 holding the thermostat 4, the heat generating member 12, and the heat shield plate 13, and engaging the mounting flange 14b of the fixture 14 with the stepped portion 15a of the lower seam plate 15. After that, the lower seam plates 15 are stacked. At this time, the lead wire 4a of the thermostat 4 and the main and auxiliary heating plates 8, 10
The lead wires 8a and 10a are led out from the through hole 14a of the fixture 14.

After this, the bulging portion 15c of the lower seam plate 15 and the upper seam plate 2 are spot welded, and each component of the heat generating member 12 and the center portion of the heat shield plate 13 are pressed between the upper and lower seam plates 2 and 15. Furthermore, upper and lower seam plates 2 and 1
5, and the fitting end faces 1a of these side walls 2b and 15d are arc welded in an inert gas such as argon gas to make them watertight, and the heat generating member 12 and the heat shield plate 13 are further firmly clamped. A submersible heating element 1 is formed.

Further, as is clear from the above structure, the thermostat 4 which is pressed and held inside the upper seam plate 2 of the submersible heating element 1, after the submersible heating element 1 is assembled,
It has a removable structure. That is, since the maximum outer diameter of the presser spring 5 is smaller than the inner diameter of the through hole 14a of the fixture 14, by removing the screw 6 with a screwdriver or the like, the presser foot that presses and holds the thermostat 4 against the upper seam plate 2 can be removed. The spring 5 can be removed and the thermostat 4 can be taken out through the through hole 14a of the fixture 14. Moreover, the reverse is also possible.

As shown in FIG. 3, the submersible heating element 1 of the above embodiment has a seal packing 2 at the inner bottom of the water storage container 21.
2, 22', and the main body mounting plate 23, and then tighten the nut 24.
Accordingly, the submersible heating element 1 is attached by tightening the attachment 14 with screws, and then covered with the base 25.

When the submersible heating element 1 is energized, the heating member 12 having the main and auxiliary heating plates generates heat and heats the water via the upper and lower seam plates 2 and 15. The thermostat 4 has a heat-sensitive portion attached to the upper seam plate 2 in a thermosensitive manner, and is activated by sensing a temperature substantially equal to the temperature of the hot water.

Next, when the underwater heating element 1 is energized in the air,
The temperature of the upper seam plate 2 rises rapidly. At this time, the upper seam plate 2 is a ferrite-based stainless steel plate that does not contain nickel, so it has high thermal conductivity, and the temperature sensing part of the thermostat 4 is located at the center of the flat plane of the upper seam plate 2. Since the distance from the heat generating member 12 is short and heat conduction is fast,
The thermostat 4 senses the temperature in a short time and can cut off the current, and the submersible heating element 1 is not overheated to an extremely high temperature and damaged.

As described above, the underwater heating element of the present invention includes a heat generating member surrounded by a heat-resistant insulating material, an upper seam plate and a lower seam plate that cover the heat generating member, and an upper seam plate in the center of the upper seam plate. It has a thermostat disposed inside so as to be in contact with the container, and a hollow cylindrical fixture that fixes the lower seam plate to the container, and a plurality of bulges arranged on the lower seam plate are passed through the heat generating member. Since it is bonded to the above upper seam plate, the heat generating member is securely clamped between the upper seam plate and the lower seam plate, preventing the heat generating member from floating.As a result, the thermostat due to local temperature rise It can prevent malfunction of the
The water is reliably conducted to the water in the container through the lower seam plate, and a thermostat is installed in the center of the upper seam plate so that it is in contact with the upper seam plate.
Thermostats can accurately control the temperature of the heated object, and even when the food is not cooked, the distance between the heating element and the thermosensing part of the thermostat is short, allowing the thermostat to operate in a shorter time. As a result, abnormal temperature rises in the submersible heating element can be suppressed to a low level.Furthermore, since the thermostat is configured to be removable through the hollow cylindrical fitting, it can be easily removed after the submersible heating element is manufactured. Or, even if the thermostat breaks down during use, only the thermostat can be taken out through the hollow cylindrical fixture without having to replace the entire submersible heating element.
Productivity and serviceability can also be greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a submersible heating element showing an embodiment of the present invention, Fig. 2 is an exploded perspective view of the same component parts, and Fig. 3 is a water heater showing an example of using the submersible heating element. It is an overall view with a partial cross section. 1... Submersible heating element, 2... Upper seam plate, 4...
...Thermostat, 12...Heating member, 14...
Fixture, 15...Lower seam plate.

Claims (1)

[Claims] 1. A heat generating member surrounded by a heat-resistant insulating material, an upper seam plate and a lower seam plate that cover the heat generating member, a thermostat installed in the center of the upper seam plate so as to be in contact with the upper seam plate, and a lower seam plate. a hollow cylindrical fixture for fixing the plate to the container, a plurality of bulges arranged on the lower seam plate are passed through the heat generating member and joined to the upper seam plate, and the thermostat is connected to the upper seam plate. is a submersible heating element characterized in that it is configured to be attachable and detachable through the above-mentioned fitting.