JPS5977816A - Follow cooking circuit for rice cooker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an additional cooking circuit for a rice cooker, and more specifically, to a rice cooker that uses a delay switch consisting of a bimetal and a positive temperature coefficient thermistor to perform additional cooking after the end of rice cooking. Concerning the additional cooking circuit of the vessel.

Conventional technology Traditionally, as a rice cooker additional cooking circuit, a mechanical type consisting of a synchronous motor etc. It is generally known that when the timer is activated and condensation forms on the inner surface of the inner pot about 15 minutes after the end of rice cooking, the rice heater is energized to cook additional rice for about 2 minutes. There is.

By the way, since the additional cooking circuit of the rice cooker as described above uses an expensive mechanical timer using a synchronous motor or the like, there is a problem that the cost of the rice cooker increases. Furthermore, since the timing of additional cooking is determined by a timer regardless of the external conditions used, there is a problem in that the additional cooking status changes depending on, for example, winter, summer, amount of rice cooked, etc.

Purpose of the Invention The present invention has been made to solve the above-mentioned problems in the conventional additional cooking circuit of a rice cooker. By setting the additional cooking time and timing with bimetal,
The aim is to use an inexpensive bimetal and a positive temperature coefficient thermistor instead of a mechanical timer to reduce the cost of the rice cooker's additional cooking circuit and to stabilize the additional cooking state.

SUMMARY OF THE INVENTION Therefore, the present invention provides a rice cooker in which a center thermometer detects when the temperature of the inner pot has reached the rice cooking completion temperature and shuts off the rice cooking heater from one source. A first changeover switch that connects the rice cooking heater from a power supply side contact connected to a power source to another contact, and a second changeover switch that turns from off to on in conjunction with the first changeover switch. On the other hand, there is a delay switch consisting of a bimetal that turns off when the reversal temperature is reached due to heating and a positive temperature coefficient thermistor thermally coupled to the bimetal, and a delay switch that turns off when the temperature inside the inner pot condenses after the center thermo is activated. The additional bimetal, the positive temperature coefficient thermistor, and the second changeover switch are connected in series between both ends of the power supply, and one end of the positive coefficient thermistor and the first changeover switch are connected in series. It is characterized in that the bimetal of the delay switch is connected between the other contact point.

Example Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In the figure, 11 is a delay switch, 12 is a rice cooking heater,
13 is a first changeover switch controlled by a center thermometer (not shown) that detects the presence or absence and temperature of the inner pot of a rice cooker (not shown); 14 is the first changeover switch 13;
a second selector switch that turns from off to on in conjunction with 1;
5 is an additional bimetal.

The delay switch 11 includes a break-type bimetal 16 that turns off when the temperature rises due to heating, and a positive temperature coefficient thermistor 17 that heats the bimetal 16.

On the other hand, the center thermostat that controls the first changeover switch 13 and the second changeover switch 14 is attracted to the center of the bottom of the inner pot of the rice cooker when the temperature of the inner pot is low, for example. , which has a well-known temperature-sensitive ferrite that is removed from the inner pot when the temperature of the inner pot exceeds a predetermined temperature after rice cooking is completed. When the temperature-sensitive ferrite is removed from the inner pot, the first changeover switch 13 moves its movable contact 18
As shown by the dotted line, the fixed contact 19 is switched to another fixed contact 20, and the second changeover switch 14
The movable contact 21 switches from the fixed contact 22 to another fixed contact 23 as shown by the dotted line.

The additional cooking bimetal 15 is a break type bimetal that turns off when the temperature exceeds 80℃ and turns on when the temperature is lower than 70℃. It is installed in such a position that it turns on when condensation occurs on the inside surface.

The rice cooking heater 12 is connected between the movable contact 18 of the first changeover switch 13 and one end of the power source 24, and the fixed contact 19 of the first changeover switch 13 is connected to the other end of the power source 24. .

On the other hand, the movable contact 21 of the second changeover switch 14
A delay switch 1 is connected to one end of the second selector switch 14 and between the fixed contact 23 of the second changeover switch 14 and the other end of the power supply 24.
A positive characteristic thermistor 17 and an additional bimetal 15 are connected in series.

The bimetal 16 and the positive temperature coefficient thermistor 17 of the delay switch 11 are connected to the fixed contact 20 of the first changeover switch 13.
and the fixed contact 23 of the second changeover switch 14.

The additional cooking circuit of the rice cooker having the above configuration operates as follows.

Put the inner pot of the rice cooker into the outer pot, press the lever (not shown),
When the temperature-sensitive ferrite of the center thermo is attracted to the inner pot side, the movable contact 18 of the first changeover switch 13 becomes the fixed contact 19, and the movable contact 2 of the second changeover switch 14 becomes the fixed contact 19.
1 is connected to a fixed contact 22, power is supplied to the rice cooking heater 12 from a power source 24, and rice cooking is started.

By energizing the rice cooking heater 12, the temperature inside the inner pot rises and rice is cooked, but as the rice cooking approaches the end, the moisture inside the inner pot decreases and the temperature of the inner pot exceeds 100°C. and rise rapidly.

When the temperature of the inner pot exceeds 100℃ and rises to a predetermined temperature as described above, the temperature-sensitive ferrite comes off from the inner pot,
The movable contact 18 of the first changeover switch 13 is a fixed contact 20
Also, the movable contacts 21 of the second changeover switch 14 are respectively switched to the fixed contacts 23.

At this time, the temperature of the additional heating bimetal 15 exceeds 70°C, and it has already been turned off.

As mentioned above, a certain period of time (approximately 15
minutes) have elapsed and condensation occurs on the inner surface of the inner pot, the reheating bimetal 15 is turned on.

When the additional cooking bimetal 15 is turned on as described above, the rice cooking heater 12 is energized again and additional cooking is started, while the positive characteristic thermistor 17 of the delay switch 11 is also energized and the positive characteristic thermistor 17 is turned on. I get a fever. This additional cooking time is preferably about 2 minutes.

After about 2 minutes of additional cooking, the temperature of the bimetal 16 rises due to the heat of the positive temperature coefficient thermistor 17, and when the bimetal 16 reverses as shown by the dotted line, the electricity to the rice cooking heater 12 is cut off and additional cooking is stopped. Complete.

If the temperature of the additional cooking bimetal 15 is kept from exceeding 80° C. during additional cooking, the additional cooking bimetal 15 will continue to be turned on after starting additional cooking.

Therefore, the bimetal 16 of the delay switch 11 continues to be turned off even after the additional cooking is completed.

As described above, the additional cooking circuit of the rice cooker can be constructed using an inexpensive bimetal and a positive temperature coefficient thermistor instead of a mechanical timer using an expensive synchronous motor or the like.

In the above embodiment, the connection position of the additional bimetal 15 and the connection position of the second changeover switch 14 can be exchanged, and the above-described connection position between the positive temperature coefficient thermistor 17 of the delay switch 11 and the power supply 24 can be Additional bimetal 15
and the second changeover switch 14 may be connected.

Effects of the Invention As is clear from the detailed explanation above, the present invention uses a bimetal and a positive temperature coefficient thermistor to configure the additional cooking circuit of the rice cooker. There is no need for an expensive mechanical timer like in the cooking circuit, and a low-cost additional cooking circuit for the rice cooker can be obtained. In addition, the timing of additional cooking can be automatically adjusted depending on the external conditions during use, such as winter, summer, or the amount of rice cooked, so that good additional cooking can be performed.

[Brief explanation of drawings]

The figure is a circuit diagram of an embodiment of the additional cooking circuit of the rice cooker according to the present invention. 11...Delay switch, 12...Rice cooking heater, 13
...First changeover switch, 14...Second changeover switch, 15...Additional bimetal, 16...Bimetal, 17...Positive characteristic thermistor, 20...Fixed contact.

Claims (1)

[Claims] (1) In a rice cooker in which the center thermo detects that the temperature of the inner pot has reached the rice-cooking completion temperature and cuts off the rice cooking heater from the power supply, the rice cooking heater is connected to the power supply when the center thermo is activated. A first changeover switch connects one power supply side contact to another contact, and a second changeover switch that turns from OFF to ON in conjunction with the first changeover switch. It is equipped with a delay switch consisting of a bimetal and a positive temperature thermistor thermally coupled to the bimetal, which turns off when the above-mentioned operation occurs, and an additional bimetal which turns on at a temperature at which condensation occurs inside the inner pot after the center thermo is activated. , the additional bimetal, the positive temperature coefficient thermistor, and the second changeover switch are connected in series between both ends of the power supply, and between one end of the positive temperature coefficient thermistor and the other contact point of the first changeover switch. An additional cooking circuit for a rice cooker, characterized in that the above-mentioned bimetal delay switch is connected to the circuit.