JPH0779859A - Rice cooker - Google Patents

Abstract

PURPOSE:To provide a rice cooker having induction-heating means, which can precisely determine a load value. CONSTITUTION:A control circuit 17 can measure an initial water temperature in accordance with a signal from a pot temperature sensor 5. At a soaking step, an input power value measuring means 19 adds up turn-on times of an induction coil 4. After completion of the soaking step, the control circuit 17 determines a load value from the result in the initial water temperature measurement and the total time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker having an induction heating means and a load amount judging means.

[0002]

2. Description of the Related Art Some rice cookers are provided with induction heating means as a heating source, and there are also rice cookers in which the load amount such as the rice cooking capacity is judged. In this type of rice cooker, the load amount is determined as follows.

(A) During the rice cooking process, the temperature of the pan is, for example, 6
The time when the temperature rises to a certain temperature of 0 ° C to 90 ° C is measured, and the load amount is determined by the time.

(B) The load amount is determined by the number of times the induction heating means is turned on and off in a constant stroke in which constant temperature control is performed.

[0005]

However, in either of the cases (a) and (b) described above, there is a possibility that the load amount determination may be inaccurate. That is, in the case of (a), since the heating method is an induction heating method, the pan is heated by induction due to eddy current, and the temperature of the pan rises immediately above the water in the pan, and The difference in the load amount (capacity for cooking rice) does not appear so much in the change in the temperature rise time, and the load amount determination is not very accurate.

Further, in the case of (b), when the temperature of the water in the pot is low, there is a strong tendency that the change of the temperature of the water is delayed with respect to the temperature change of the pot, and the number of times of ON / OFF increases. Therefore, even if the load amount is small, it may be determined that the load amount is large.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a rice cooker capable of accurately determining a load amount.

[0008]

The rice cooker of the present invention has a pan provided in the rice cooker main body, an induction heating means for inductively heating the pan, and an induction heating means for turning the induction heating means on and off so as to maintain a substantially constant temperature. Operation control means for controlling the induction stroke and controlling the induction heating means in a set pattern to perform the rice cooking stroke, and water temperature measurement for measuring the water temperature in the pan at the start of the rice cooking operation. Means, an input electric energy measuring means for measuring an input electric energy to the induction heating means in a hit stroke, and a load amount for judging a load amount by the measurement result of the water temperature measuring means and the measurement result of the input electric energy measuring means. And a judging means (the invention of claim 1).

In this case, the input electric energy measuring means may be provided with a timer means so as to integrate the ON time of the induction heating means (the invention of claim 2). Further, the input electric energy measuring means may be provided with a timer means and configured to integrate the on-time of the induction heating means within a fixed time (the invention of claim 3). Furthermore, the input electric energy measuring means may be provided with a timer means and configured to integrate the off-time of the induction heating means within a fixed time (claim 4).
Invention).

A rice cooker of another invention is a pan provided in the main body of the rice cooker, induction heating means for inductively heating the pan, and on / off control of the induction heating means so that the pan has a substantially constant temperature. The operation control means for executing the rice cooking process by controlling the induction heating means on / off in the set pattern, the water temperature measuring device for measuring the water temperature in the pan at the start of the rice cooking operation, and the hot water process. In, the input power amount measuring means for measuring the input power amount to the induction heating means, and the load amount determining means for determining the load amount by the measurement result of the water temperature measuring means and the measurement result of the input power amount measuring means. The operation control means is characterized in that it controls the subsequent stroke based on the determination result of the load amount determination means (the invention of claim 5).

In this case, the operation control means may be configured to change the number of additional cooks in the purging stroke based on the determination result of the load amount determination means (the invention of claim 6).

Further, the operation control means may be configured to change the execution time of the purging stroke based on the judgment result of the load amount judgment means (the invention of claim 7).

Furthermore, the operation control means may be configured to change the input electric power amount when the first induction heating means is turned on in the rice cooking process based on the determination result by the load amount determination means (claim). Invention of Item 8).

In addition to this, the operation control means may be configured to change the ON time of the first induction heating means in the rice cooking process based on the determination result by the load amount determination means (the invention of claim 9). .

[0015]

When the load amount is small, the input electric power amount to the induction heating means is small in the hitting stroke under constant temperature control, and when the load amount is large, the input electric power amount to the induction heating means is large. Tend. However, when the initial temperature of the water in the pot is low even when the load amount is small, the input power amount may be similar to when the initial water temperature is high and the load amount is large.

In the means of the present invention, however, the initial water temperature can be known by measuring the water temperature in the pan at the start of the rice cooking operation by the water temperature measuring means, and the input electric energy measuring means can be used to induce in the hot water stroke. The amount of input power to the heating means can be determined by measuring the amount of input power to the heating means. Then, the load amount determining means determines the load amount based on the measurement result of the water temperature measuring means and the measurement result of the input power amount measuring means, so that the load amount can be accurately determined from the initial water temperature and the input power amount. Becomes

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, in FIGS. 2 and 3, inside the inner case 2 of the rice cooker main body 1, for example, a pan 3 formed by press-molding a plate material in which a stainless material and an aluminum material are joined is detachably arranged. There is. Further, an induction coil 4 as an induction heating means is arranged on the outer bottom portion of the inner case 2, and a pan temperature sensor 5 that comes into contact with the pan 3 is provided.

The inner case 2 and the pan 3 are opened and closed by a lid 6. In the front part of this lid 6,
An operation panel 6a is provided, and this operation panel 6a
As shown in FIG. 4, the rice cooking switch 7 for starting the rice cooking operation, the heat retaining switch 8 for starting and stopping the heat retaining process, the cooking switch 9 for separately cooking white rice, brown rice, etc. "Setting switch 10," minute "setting switch 11, reservation setting switch 12," reservation "display LED 13," rice cooking "display LED 14," heat retention "display L
An ED 15 and a display 16 for displaying time and the like are provided.

Next, in FIG. 1 showing the electrical configuration, the control circuit 17 is configured to include a microcomputer, and the pan temperature sensor 5 and the various switches 7 described above.
12 to 12, and also signals from the steam temperature sensor 18 and the input electric energy measuring means 19. The steam temperature sensor 18 is provided in a steam passage (not shown) of the lid 6 to detect the temperature of steam. Further, the input electric energy measuring means 19 has a timer means so as to integrate the ON time of the induction coil 4 in the hit stroke, and give the integrated value to the control circuit 17 as the input electric energy measured value. There is.

Then, the control circuit 17 drives the induction coil 4 in accordance with the operation program stored therein.
ON / OFF control is performed via 0, and thereby the hot water process, the rice cooking process, the Murashi process, and the heat retention process are controlled. That is, it functions as operation control means. Further, the control circuit 17 functions as a water temperature measuring means and a load amount determining means in addition to the operation controlling means.

The control contents of the control circuit 17 will be described. Now, when rice and water are stored in the pan 3 and the rice cooking switch 7 is turned on, the initial water temperature is measured based on the signal from the pan temperature sensor 5 after 30 seconds have elapsed, as shown in FIG. That is, by waiting for 30 seconds, the water temperature inside the pot 3 and the pot 3 become the same temperature, and the initial water temperature can be measured.

After this, the process shifts to the hitting stroke. In the hot stroke, the induction coil 4 is turned on / off so as to maintain a substantially constant temperature (hot temperature K0). in this case,
First, the induction coil 4 is turned on, and when the temperature detected by the pan temperature sensor 5 reaches the upper reference temperature K1, the induction coil 4 is turned off,
The temperature detected by the pan temperature sensor 5 is the lower reference temperature K2.
Then, the induction coil 4 is turned on, and the temperature is controlled by repeating this to control the soaking stroke. In this case, the input power (W) when the induction coil 4 is turned on is controlled to be constant.

Then, in this hitting stroke, the input power measuring means 19 integrates the on-time of the induction coil 4. When the soaking stroke ends after a predetermined time has elapsed, the control circuit 17 determines the load amount based on the above-described initial water temperature measurement result and the integration time. In this case, the load amount is obtained as follows. That is, the load amount and the heat amount required for heating are represented by a relationship such as (input power) x (on time) = (load amount) x (boiler temperature-initial water temperature) x α. Note that α is a constant. With this, (load amount) = α × {(input power) × (on time)} /
(Hot water temperature-initial water temperature).

As can be seen, when the input power amount, that is, (input power) × (ON time), is large, the load amount is large, and as the initial water temperature becomes lower, the load amount becomes smaller. The amount of load can be properly determined as a result.

Then, the control circuit 17 controls the subsequent process according to the determined load amount. That is, in the rice cooking process, first, the induction coil 4 is placed at a predetermined time ta.
Is turned on, and then the induction coil 4
Is repeatedly turned on for a predetermined time tc. Here, according to the load amount described above, a predetermined time ta, which is the first on-time.
(That is, change the input power). For example, when the load amount is large, the predetermined time ta is changed to be long, and when the load amount is small, the predetermined time ta is changed.
Change to shorten. After that, when the pan temperature sensor 5 detects the dry-up temperature (time point d), the panning process is started. In this purging stroke, the induction coil 4 is turned on for a predetermined time te after a predetermined time has elapsed. This is called additional cooking. Here, the control circuit 17 changes the number of times the induction coil 4 is turned on, that is, the number of additional cooks, according to the load amount. That is, when the load amount is small, the additional cooking is performed only once, and as the load amount is larger, the additional cooking is increased to two times and three times. In this embodiment, the number of additional cooks is 3
It shows the case of times.

In this embodiment, the water temperature in the pan 3 is measured at the start of the rice cooking operation, and the amount of electric power input to the induction coil 4 is measured in the soaking stroke, and the initial water temperature is measured. Since the load amount is determined based on the result and the input power amount measurement result, the load amount can be accurately determined.

In particular, the input electric energy measuring means 19 is provided with a timer means and the input electric energy is measured by integrating the on-time of the induction coil 4, so that the input electric energy can be measured relatively easily.

Further, since the subsequent stroke is controlled according to the load amount judgment result, effective stroke control can be executed according to the load amount. In particular, since the input power amount is changed by changing the on-time of the induction coil 4 at the beginning of the rice cooking process, the effective rice cooking process can be executed according to the load amount. In this case, as the input electric power, the input voltage or the input current may be changed. Further, since the number of additional cooks is changed according to the load amount, it is possible to execute an effective unevenness stroke that is appropriate for the load amount. in this case,
It is also possible to change the execution time of the purging stroke without changing the number of additional cooks.

In the above embodiment, the on-time of the induction coil 4 in the hit stroke is integrated over the entire execution time of the hit stroke. However, the on-time of the induction coil 4 is fixed within a fixed time in the hit stroke. It may be integrated, or the off time may be integrated within a certain time. When integrating the off time, it can be said that the shorter the integration time, the smaller the load amount.

[0030]

As is apparent from the above description, the present invention determines the load amount in consideration of the initial water temperature and the amount of electric power input to the induction heating means in the dipping stroke, so that an accurate load amount is determined. As a result, excellent effects such as being extremely effective for the subsequent stroke control and the like can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of an electrical configuration showing an embodiment of the present invention.

[Figure 2] Perspective view of rice cooker

[Figure 3] Vertical front view of rice cooker

FIG. 4 is a plan view of the operation panel.

FIG. 5 is a diagram showing the on / off state of the induction coil and the temperature change of the pan.

[Explanation of symbols]

1 is a rice cooker main body, 3 pans, 4 induction coils (induction heating means), 5 pan temperature sensor, 17 control circuit (operation control means, water temperature measuring means and load amount judging means), 19 input electric energy A measuring means is shown.

Claims (9)

[Claims] 1. A pan provided in the rice cooker main body, an induction heating means for inductively heating the pan, and an induction heating means for controlling the on / off of the pan so as to maintain a substantially constant temperature. Operation control means for controlling the on / off control of the induction heating means in a different pattern to execute the rice cooking process, water temperature measuring means for measuring the water temperature in the pan at the start of the rice cooking operation, and to the induction heating device in the soaking process The rice cooker comprising: an input power amount measuring unit for measuring the input power amount; and a load amount determining unit for determining a load amount based on the measurement result of the water temperature measuring unit and the measurement result of the input power amount measuring unit. 2. The rice cooker according to claim 1, wherein the input electric energy measuring means includes a timer means and is adapted to integrate the ON time of the induction heating means. 3. The rice cooker according to claim 1, wherein the input electric energy measuring means includes a timer means and is adapted to integrate the on-time of the induction heating means within a fixed time. 4. The rice cooker according to claim 1, wherein the input electric energy measuring means includes a timer means and is adapted to integrate the off-time of the induction heating means within a fixed time. 5. A pan provided in the rice cooker main body, an induction heating means for inductively heating the pan, and an induction heating means for controlling the on / off of the pan so that the temperature is kept substantially constant. Operation control means for controlling the on / off control of the induction heating means in a different pattern to execute the rice cooking process, water temperature measuring means for measuring the water temperature in the pan at the start of the rice cooking operation, and to the induction heating device in the soaking process Input power amount measuring means for measuring the input power amount of, and a load amount determining means for determining the load amount by the measurement result of the water temperature measuring means and the measurement result of the input power amount measuring means, the operation control means, A rice cooker characterized in that the subsequent process is controlled based on the determination result of the load amount determination means. 6. The operation control means is adapted to change the number of additional cooks in the purging stroke based on the determination result of the load amount determination means.
The listed rice cooker. 7. The rice cooker according to claim 5, wherein the operation control means is configured to change the execution time of the purging stroke based on the determination result by the load amount determination means. 8. The operation control means is adapted to change the input electric power amount when the first induction heating means is turned on in the rice cooking process based on the judgment result by the load amount judgment means. The rice cooker according to claim 5. 9. The operation control means is adapted to change the ON time of the first induction heating means in the rice cooking process on the basis of the judgment result of the load amount judgment means. rice cooker.