JPS628842Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electric kettle, and in particular, uses a changeover switch to select a position where the pot automatically heats at a set temperature after boiling and a position where it heats at a set temperature from the beginning.

Electric pots usually have a fixed thermostat that heats water to boiling temperature and then intermittently heats it around boiling temperature, or it sets the desired temperature at the beginning of energization and then returns to the set temperature after reaching the set temperature. Some have a variable thermostat that heats the area adiabatically. In the former case, it is not possible to continuously keep the water temperature below the boiling temperature, for example, about 50 to 60 degrees, for tea ceremony, and it consumes more electricity than necessary, whereas in the latter case, it is possible to keep the water temperature below the boiling temperature continuously. Since heating is performed using a single thermostat, there are large variations in the set temperature, making it unsuitable for use, for example, in keeping babies warm at an accurate optimum temperature (approximately 36 degrees Celsius).

The present invention was developed in view of the above-mentioned drawbacks, and allows heating conditions to be selected according to various usage conditions.
This will be explained below based on the drawings. 1 is AC power supply, 2
3 is a fixed high-temperature thermostat that is turned off and manually turned on at temperatures above the boiling temperature (90 to 95 degrees), and is connected in series to the first heater 2. . 4 is a movable contact piece 4a
is connected to the high-temperature thermostat 3, one contact 4b is connected to the power supply 1, and the other contact 4c is connected to the connection between the second heater and the low-temperature thermostat, which will be described later. The position where the movable contact piece 4a and one contact 4b are initially heated at the set temperature (the connection position between the movable contact piece 4a and one contact 4b) and the position where the set temperature is heated from the beginning (the movable contact piece 4a and the other contact 4c)
connection position). Reference numeral 5 denotes a second heater with a small heat output, which has one end connected to the other contact 4c of the changeover switch 4 and the other end connected to the first heater 2; 6, one end connected to the power source 1, and the other end connected to the changeover switch. A variable low temperature thermostat connected to the other contact 4c of 4 is designed to turn off at an arbitrary set temperature.

Next, to explain the operation, if you first heat tap water to boil and set it to a desired temperature (for example, about 36 degrees) and then keep it warm, set the low temperature thermostat 6 to 36 degrees on the scale (not shown) and then switch. Connect the movable contact piece 4a of the switch 4 to one contact 4b, turn on the high temperature thermostat 3, and apply power. A series circuit of the high temperature thermostat 3 and the first heater 2 is directly inserted into the power source 1, and the first heater 2 generates heat to heat water. During the temperature rise process at this time, approximately 36
The low-temperature thermostat 6 turns OFF at around 30°F.
Eventually, as time T elapses as shown by the solid line A in Figure 2, when the temperature reaches near the boiling temperature (approximately 90 to 95 degrees), the high-temperature thermostat 3 turns off, all heaters stop generating heat, and the first heater 2 A series circuit of a low temperature thermostat 6 and a second heater 5 is inserted in series. When the temperature of the hot water drops rapidly and reaches around 36 degrees, the low temperature thermostat 6 is turned on and the water is heated again, after which the temperature is maintained at the set temperature by the thermostat 6. Since the total calorific value during this heat retention is considerably lower than the calorific value of the first heater 2 alone, the difference in height (differential) around the set temperature is small, which requires the sterilizing effect of boiling and the accuracy of the optimum temperature. Ideal for breastfeeding.

On the other hand, if you want to continuously obtain the desired temperature (e.g. about 70 degrees) from the beginning, set the low temperature thermostat on the scale.
After setting to 70 degrees, move the movable contact piece 4 of the changeover switch 4.
A is switched to another contact 4c to connect the high temperature thermostat 3 and the low temperature thermostat 6 in series, and also to connect to the power supply via the first heater 2 to turn on the high temperature thermostat 3. As shown by the dotted line B in Figure 2, the first heater 2 is inserted directly into the power supply 1, so it is rapidly heated until it reaches the set temperature.When the set temperature is reached, the low temperature thermostat 6 is turned on.
After turning off, the temperature is kept within a range with a slight temperature difference.

Here, regardless of which contact the movable contact piece 4a of the changeover switch 4 is connected to, if the high temperature thermostat 3 is not turned on manually, the low temperature thermostat 6, the second heater 5, and the first heater 2 are turned on. A series circuit of is inserted into the power supply 1 and heated slowly to the set temperature (70 degrees) in the same way as described above. When the set temperature is reached, the temperature is kept within a range with a small temperature difference as shown by the dashed line C in Figure 2, so the hot water is not heated. Suitable for etc. That is, when boiling is not particularly required as in this case, it is suitable for boiling the water in a kettle or the like and then storing it in the main body of the present invention. Although the present invention uses a changeover switch with a movable contact piece and two contacts, if the operation shown in the dotted line B in Figure 2 is not required, the switch may not necessarily have two contacts. One is enough.

As described above, the present invention uses a first heater that generates a large amount of heat and a second heater that generates a small amount of heat, and one end of which is connected to the connection between the first heater and the second heater.The device is turned off at around the boiling temperature and then turned on manually. A high temperature thermostat, a changeover switch connected in series to the other end of the thermostat, connected in series to the second heater, and this series circuit connected in parallel to a series circuit of the changeover switch and the high temperature thermostat. Therefore, depending on the position of the changeover switch, the position that automatically heats at the set temperature after boiling can automatically sterilize and maintain the set temperature, making it ideal for breastfeeding, for example, and the position that heats at the set temperature from the beginning. It is possible to switch according to various usage conditions, such as being able to keep hot water heated with other appliances warm without boiling it.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram used in the electric pot of the present invention, and FIG. 2 is a diagram showing temperature characteristics at each switching position of the changeover switch. 2...First heater, 3...High temperature thermostat, 4...Selector switch, 5...Second heater, 6...Low temperature thermostat.

Claims (1)

[Scope of utility model registration request] A selectively selectable changeover switch, a high-temperature thermostat that closes manually and opens near boiling temperature, and a first heater that generates a large amount of heat are connected in series to the power supply, and a variable-type low-temperature thermostat and a high-temperature thermostat that generates a large amount of heat are connected in series. An electric pot characterized in that a series circuit of a small second heater is connected in parallel with a series circuit of the changeover switch and the high temperature thermostat.