JPS6245615Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting the temperature of a liquid contained in an electric pot.

As a conventional built-in structure for the heater and temperature control device of electric pots, etc., for example, an opening is provided at the bottom of the container, the heater is attached to the opening so that the heating surface of the heater is exposed inside the container, and the temperature control device is installed on the back side of the heater. As for the assembled structure or other built-in structure, a submersible heater is attached to the bottom of the container, a protrusion is provided at the bottom of the container so as to come into contact with the back side of the submersible heater, and a temperature control device is assembled on the outside of the protrusion. There are some types of heaters with a strip heater wrapped around the outer circumference of the bottom of the container, a protrusion in the center of the container, and a temperature control device attached to the outside of the protrusion. In the built-in structure, the temperature control device is not installed in a position that is exposed to the heat convection of the internal solution caused by heating of the built-in heater, so there is a delay in liquid temperature detection and accurate liquid temperature control is not possible. There is a drawback. In addition, if the temperature control device is attached to the back of the heater or the temperature control device is attached to the outside of the protrusion on the bottom of the container that comes into contact with the back of the submersible heater, the temperature control device is always on the heater. Since it is in contact with a heat generating part, the operating temperature of the temperature control device installed therein, such as a thermostat, is set extremely high, so there is a large difference between the temperature rise of the internal solution and the operating temperature of this thermostat. Although it can be used simply to prevent the heater from burning out, it has the drawback that it is extremely difficult to control the liquid temperature.

The present invention has been made to eliminate these drawbacks.

Embodiments of the present invention will be described below with reference to the drawings. 1 is a container made of stainless steel, glass, ceramics, etc., and shaped into a pot shape. Reference numeral 2 denotes the bottom of a container 1 formed into a thin wall, and a recess 3 is formed approximately in the center thereof. 4 is an electric heater that heats the internal solution, such as a ceramic heater, a cartridge heater, a space heater, etc.
is installed in the recess 3, and its upper surface is assembled at a position substantially flush with the upper edge of the recess 3. Reference numeral 5 denotes a protruding portion formed by protruding the inner surface of the bottom portion 2 of the pot-shaped container 1. A temperature sensor 6, such as a thermistor, barium titanate porcelain, etc., placed in a temperature control circuit 8 is fixed to the outside of the protrusion 5 by means of adhesive or the like. Reference numeral 7 denotes a bottom cover made of synthetic resin or the like, which is attached to the outer periphery of the bottom of the container 1 so as to enclose the temperature sensor 6, electric heater 4, temperature control circuit 8, etc., and is assembled integrally with the container 1.

When a liquid 9 is placed in the container 1 of the electric pot constructed as described above and electricity is applied, the electric heater 4 is heated, and this amount of heat is transmitted to the liquid 9 in the container 1, causing convection on the inner surface of the pot-shaped container in the direction of the arrow. Since the flow is repeated, the liquid 9 is heated one after another.

In addition, the protrusion 5 provided at a position that contacts the convection flow is heated in almost the same way, and the temperature sensor 6 fixed to the outside of the protrusion 5 quickly detects the liquid temperature, and when the liquid temperature reaches the upper limit temperature setting, the temperature sensor 6 is fixed to the outside of the protrusion 5. Immediately, the temperature control circuit 8 turns off the power to the electric heater 4 to stop heating. Further, when the temperature sensor 6 detects that the liquid temperature has reached the lower limit set temperature due to natural cooling, the temperature control circuit 8 starts energizing the electric heater 4.
The liquid 9 is heated, and this energization and de-energization is repeated to accurately control the liquid temperature to a preset temperature.

Since the present invention is constructed and operates as described above,
It has excellent effects as explained below.

That is, in conventionally known electric pots,
Due to the cross-sectional shape of the container, there is a hidden non-heating part behind the liquid convection flow in the liquid heating part, which prevents accurate liquid temperature from being transmitted to the temperature control sensor. Since it does not include areas where the liquid temperature is uneven, it allows for more accurate temperature control than ever before. In particular, in the present invention, the cross-sectional shape of the container required for this purpose is formed to be an inverse parallelepipole, so that the heat convection heated by the electric heater is inductively brought into contact with the temperature sensor without waste. Therefore, there is no delay in temperature control that occurs conventionally. By the way, the results of the applicant's experimental confirmation of this result are shown in Figure 2. That is, the X and X' lines show the temperature rise at the mounting part of the temperature control device with the conventional structure, which has many of the drawbacks mentioned above, while the Y line shows the temperature rise at the mounting part of the temperature sensor 6 with the structure of the present invention. It is something that

In the conventional structure, the difference between the liquid temperature and the temperature at the mounting part of the temperature control device is extremely large, whereas in the structure of the present invention, the temperature at the mounting part of the temperature sensor 6 is extremely large. This shows that there is almost no difference between the temperature rise and the temperature rise of the liquid 9.

Thus, the present invention has a temperature sensor installed in the protrusion that comes into contact with the convection flow caused by the heating of the liquid in the pot, so that the exact temperature rise of the liquid can be quickly sensed, making it extremely reliable. Can be controlled. Furthermore, since the temperature sensor is filled with an adhesive or the like inside the protrusion, it has no contact with the outside air and is not affected by changes in outside temperature, making it a very effective device as it can only detect the temperature of the liquid.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an electric pot incorporating the temperature detection device of the present invention, and FIG. 2 is a comparison diagram of temperature rises between the liquid and the temperature sensor mounting portion of the conventional electric pot and the present electric pot. 1... Container, 2... Bottom, 3... Recess, 4...
Electric heater, 5...protrusion, 6...temperature sensor.

Claims (1)

[Scope of utility model registration request] In the bottom structure of an electric pot that incorporates an electric heater and its temperature control device in the bottom of the container, the bottom is formed into a thin pot shape, a recess is provided approximately in the center of the pot, and the upper surface of the pot is formed into the recess. An electric heater was assembled so as to be almost flush with the upper edge, the inner surface of the container was made to protrude at a position where it came into contact with the thermal convection of the internal solution produced by the electric heater, and a temperature control sensor was placed outside of the protrusion. A temperature detection device for an electric pot characterized by the following.