JPH0751104B2 - rice cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rice cooker including a heating coil for induction heating.

2. Description of the Related Art A conventional rice cooker of this type has a main body 1 as shown in FIG.
A storage part 4 for storing a pot 3 which is a container for rice 2 is provided inside, and the upper portion of the main body 1 is covered with an upper lid 5 so that it can be opened and closed. The pot 3 can be taken out by opening and closing the upper lid 5. I am trying. A bottom heater 6 and a side heater 7, which are resistance heaters, are attached to the bottom and side surfaces of the storage section 4, respectively. Further, a load detection device 8 for detecting the presence or absence of the pan 3 is attached to the bottom of the storage unit 4, and the load detection device 8 has a control unit 9 if the pan 3 is present.
The signal with a pot is output to. The control unit 9 uses the pan detection device 8
In response to the signal indicating that the pot is present, the bottom heater 6 and the side heater 7 are energized and the operation display unit 10 provided on the top of the main body 1 is controlled.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in such a configuration, the rice cooker body 1 is 1.
If it has a large capacity such as 8 liters, it is not possible to cook a small amount of rice (about 0.18 liters), even if a 1.8 liter main body 1 is used for a 1 liter small amount rice cooker 3. , There was a problem that small amount of rice could not be cooked well. This is for the following reason.

In other words, when cooking rice, the rice 2 must have a certain thickness from the bottom of the pan 3 in order to cook delicious rice.
If the thickness from the bottom is too small, the convection of rice and water will not be sufficient, and the rice will not be fluffy and delicious.
Therefore, if you cook rice by putting about 1 go of rice 2 into a large capacity pot 3 such as a 1.8-liter pot, the rice 2 will be 5m from the bottom of the pot 3.
It was only about m thick, so I couldn't make delicious rice.

Also, when the small capacity cooking pot 3 is used for the large capacity body 1, the distance between the cooking pot 3 and the bottom heater 6 and the side heaters 7 becomes large, and the heat transfer to the cooking pot 3 becomes very bad, which causes high temperature. I couldn't cook, and as a result, I couldn't cook long and delicious plump rice.

Therefore, an object of the present invention is to enable a large capacity rice cooker to cook a small amount of rice deliciously.

Means for Solving the Problems And the technical means of the present invention for achieving the above object, a heating coil for induction heating a pot, an inverter circuit for supplying a high-frequency current to the heating coil, and an oscillation of the inverter circuit. A control circuit for controlling and a pan discriminating means for discriminating between a large-capacity pot and a small-capacity pot are provided, and the control circuit controls the oscillation of the inverter circuit according to the signal from the pan discriminating means. The input power to the entire heating coil is uniformly switched.

Action The action of this technical means is as follows.

That is, if you want to cook a large amount of rice of about 1.8 liters, you can use the large-capacity pot to cook ordinary rice. Also, if you want to cook a small amount of rice, such as about 1 go, use a small-capacity pot with a small diameter so that the rice has a sufficient thickness from the pot bottom and the bottom of the pot has a large capacity. Similar to the case, induction heating can be performed using the pot directly as a heat source, and the lower side of the pot has a slight decrease in magnetic flux coupling as compared to the case of a large capacity pot, but Induction heating of the lower side of the small-capacity pan is performed by magnetic flux coupling between the heating coils that are not placed, so the entire pan is heated, and as with the large-capacity pan, it is almost ideal among small-capacity pans. Therefore, even when a small amount of rice is cooked, the same delicious rice as when cooked with a small-scale rice cooker can be cooked.

Embodiment One embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, 11 is a main body of a rice cooker using induction heating, and is a large capacity pot 13a or a small capacity pot 13b (hereinafter, large capacity pot 13a and small capacity pot 13b) which is a container for putting rice 12 inside.
(Also referred to as "nabe 13")
14 is provided, and the upper portion of the main body 11 is openably and closably covered by an upper lid 15, so that the pan 13 can be taken out by opening and closing the upper lid 15. On the bottom lower surface of the storage section 14,
A heating coil 16 for induction heating the pot 13 is provided. Further, the bottom of the storage portion 14 is attached to the pan discriminating means 17a, 17b, 17c for discriminating the bottom diameter of the pan 13, the pan discriminating means 17a, 17b, 17c, the control circuit 18, the pan 13 is. Large capacity pot 1
Send a signal to determine whether it is 3a or small capacity pot 13b.

The control circuit 18 controls the oscillation of the inverter circuit 19 so as to uniformly switch the input power to the entire heating coil 16 in accordance with the signals from the pan discriminating means 17a, 17b, 17c, and is provided on the upper part of the main body 11. The operation unit 20 is controlled.

In the above configuration, when the power switch 21 is turned on, the control circuit 18 outputs a signal from the pan discriminating means 17a, 17b, 17c that the pan is either the large capacity pan 13a or the small capacity pan 13b. , Oscillates the inverter circuit 19. The inverter circuit 19 supplies a high-frequency current to the heating coil 16, and the load pan 13
To heat. Here, when the pot is heated by induction heating, electric power is consumed by using the pot as a heating element, so that heat transfer to the pot is almost constant even if the shape of the pot is different.

In addition, the pot discriminating means 17a, 17b, 17c,
It detects that it is covered by the bottom of the pot 13 and sends a signal to the control circuit 18. When the control circuit receives a signal covered by the bottom surface of the pan 13 from all of the pan identifying means 17a, 17b, 17c, the pan 13
Determines that it is a large-capacity pot 13a, and controls the oscillation of the inverter circuit 19 so that the input power becomes the predetermined power (generally about 1200 W) for large-capacity rice cooking. On the other hand, of the pot discriminating means, if only 17b receives a signal covered by the bottom of the small-capacity pot 13b, the pot 13 is determined to be the small-capacity pot 13b,
The input power of the entire heating coil 16 should be suppressed more uniformly than in the case of the large capacity pan 13a (generally 900W to 1000W
Control the oscillation of the inverter circuit 19.

Therefore, when the pan is the large capacity pan 13a and when the pan is the small capacity pan 13b, the rice can be cooked with the input power at the time of cooking as the optimum power.

The pot discriminating means 17a, 17b, 17c are mechanical switches shown in FIG. 2, and the pot 13 outputs a signal by pushing the switch, or the electric capacitance shown in FIG. As a formula, there is a method of detecting a change in the signal level when the pot 13 is above the electrode 22 and when it is not, but the same effect can be obtained even if the method is different.

Next, another embodiment of the present invention will be described.

FIG. 4 shows another embodiment, in which a pan selection switch 23 is provided in place of the pan determination means 17a, 17b, 17c of FIG. 1, and the signal from the pan selection switch 23 is controlled by a control circuit. In response to this, the control circuit 18 controls the oscillation of the inverter circuit as in the first embodiment, and as a result, has the same effect as in the first embodiment.

EFFECTS OF THE INVENTION As is apparent from the above description of the embodiments, according to the present invention, when a large capacity rice is desired to be cooked, a large capacity pan can be used for normal rice cooking, and a small amount of rice can be used. If you want to cook a large amount of rice, you can use a small-capacity pot to make the rice have a sufficient thickness from the bottom of the pot, and
As for the bottom of the pan, induction heating can be performed by using the pan directly as a heat source, as in the case of the large capacity pan, and the lower side of the pan has a slight decrease in magnetic flux coupling compared to the case of the large capacity pan. However, since the lower side of the small-capacity pan is induction-heated by magnetic flux coupling between the small-capacity pan and the heating coil part where the small-capacity pan is not placed, the entire pan is heated, which is different from the case of the large-capacity pan. Similarly, even in a small-capacity pot, almost ideal convection will occur, and you can cook delicious rice in the same way whether you cook large-capacity rice or small-capacity rice with one body.

[Brief description of drawings]

FIG. 1 is a longitudinal cross-sectional view of the essential configuration of a rice cooker according to an embodiment of the present invention, FIG. 2 is a configuration diagram of an embodiment of the pot identifying means, and FIG. 3 is another embodiment of the pot identifying means. FIG. 4 is a longitudinal sectional view of the essential parts of a rice cooker according to another embodiment of the present invention, and FIG. 5 is a longitudinal sectional view of the essential parts of a conventional rice cooker. 16 ... Heating coil, 18 ... Control circuit, 19 ... Inverter circuit, 17a, 17b, 17c ... Pan identification means, 23 ... Pan selection switch.

Claims (1)

[Claims] 1. A heating coil for inductively heating a large-capacity pan and a small-capacity pan that can be selectively used, an inverter circuit for supplying a high-frequency current to the heating coil, a control circuit for controlling oscillation of the inverter circuit, and a large capacity. The control circuit controls the oscillation of the inverter circuit in response to a signal from the pot determining unit to determine the input power to the entire heating coil. Rice cooker that can be switched evenly.