JP2000046340A - Heater/cooker with boiling function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heater/cooker having a boiling function, e.g. a gas table cooking stove, in which boiling can be detected accurately regardless of the quantity of hot water by determining the quantity of hot water in a kettle, or the like, and controlling the decision element, i.e., the boiling detection time, of a boiling decision means variably based on the determination result. SOLUTION: A gas burner 12 is fed with fuel gas from main and sub-gas ducts 14, 20 and combustion operation is started by turning an igniting/ extinguishing switch 22 on. When boiling mode is selected by operating a cooking mode switch on an indicating/operating board 46 following to ignition, outer bottom temperature of a kettle 32 on the gas burner 12 is detected one by one by means of a temperature detector 34 and a detection signal is delivered through a temperature detecting circuit 38 to a microcomputer 24. The microcomputer 24 detects a boiling state and switches the quantity of gas to a minimum level for sustaining the boiling state by controlling a switching solenoid valve 18. Quantity of hot water is detected from the degree of temperature rise thereof and a boiling detection time for determining the boiling state is controlled based on the detection results.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating cooker, and more particularly to a heating cooker such as a gas stove provided with a water heater function, which switches boiling control depending on the amount of hot water. It relates to boiling detection technology.

[0002]

2. Description of the Related Art Conventionally, a gas stove provided with a water heater has been known as this type of heating cooker. In such a gas table stove, for example, when cooking a boiled or oiled product, the detection of the boiling state is performed by automatic discrimination control. That is, when the temperature of the cooking pot is within a predetermined temperature range for a predetermined time in the case of a boiled food or an oily substance, it is determined by automatic discrimination that the boiled or oily substance is in a boiling state, and combustion is performed. Control.

In the case of boiled or oily products, setting the automatic determination condition that the boiling state is determined for a predetermined time within a predetermined temperature range is a determination that takes a relatively long time. There is no problem in relation to the time until scorching of the boiling pot. In addition, it is necessary to take such a long time to prevent erroneous determination that boiling is occurring when cooking is not boiling, and to surely detect the boiling state of cooking or the like.

[0004]

However, in the case of boiling water with a kettle, when it is determined that the water has boiled, especially when the amount of hot water is small, for example, it takes two minutes to detect the boiling. Is too late. In other words, if it takes a long time to determine the boiling point when the amount of hot water is small, the hot water will boil during that time, which may lead to idle heating.

The inventor of the present invention believes that the gradient of temperature rise up to boiling differs depending on the amount of hot water. That is, when the amount of hot water is small, the temperature gradient up to boiling is large, the sensor temperature rises to some extent even after boiling, and the amount of hot water is large. In this case, attention was paid to the fact that the temperature gradient up to the boiling point is gentle and the state is almost equilibrium after the boiling (the actual hot water temperature is in the equilibrium state at about 100 ° C. after the boiling).

FIG. 5 shows the difference in temperature gradient up to boiling when the amount of hot water is large and when the amount of hot water is small. When the amount of hot water is large, the gradient of the temperature gradient is small, and a certain hot water temperature T _W0 (for example, 85 ° C.) and the hot water temperature T _W1 (for example, 95 ° C.)
(T ′ ₀ → t ′ ₁ ) takes a long time, and the time during which the boiling temperature is detected and the detection range of the boiling temperature falls within the range of ± 2 ° C. is long.

On the other hand, when the amount of hot water is small, the gradient of the temperature gradient becomes large, and the temperature of the hot water is changed from T _W0 (85 ° C.) to T _W1.
(T ₀ → t ₁ ) to reach (95 ° C.) is short,
It can be seen that the time (t _F ) in which the detection range of the boiling temperature is in the range of ± 2 ° C. in the boiling state is also short.

The problem to be solved by the present invention is that the difference in the gradient of the sensor temperature in the boiling state is changed by changing the time for entering a certain temperature range (for example, ± 2 ° C.). An object of the present invention is to provide a heating cooker that corrects a difference, detects a boiling state at an appropriate place, and can switch to a low heat.

[0009]

According to a first aspect of the present invention, there is provided a heating cooker having a water heater function, which detects a hot water temperature of a kettle or the like. Detecting means, and boiling judging means for judging that the hot water temperature detected by the hot water temperature detecting means is in a boiling state when the hot water temperature is within a predetermined temperature range for a predetermined time. The gist of the invention is to provide a hot water amount judging means and a boiling judging control means for variably controlling a boiling detection time which is a judging element of the boiling judging means depending on the amount of hot water judged by the hot water judging means.

[0010] According to the cooking device having the above configuration, the hot water temperature is detected by the hot water temperature detecting means, and when the hot water temperature is within the predetermined temperature range for a predetermined time, it is determined that the hot water is in a boiling state. However, at that time, the amount of hot water is determined, and the boiling detection time, which is an element for determining whether or not it is in the boiling state, is variably controlled according to the amount of hot water.

Further, the cooking device according to the second aspect of the present invention further comprises a water heater mode selection switch, and determines the amount of water when the water heater mode is selected by the water heater mode switch. Means for determining the amount of hot water to perform, boiling means for determining that the water is in a boiling state when the temperature of the water is within a predetermined temperature range for a predetermined time, and means for determining boiling based on the amount of water determined by the amount of hot water when the boiling mode is selected. And a boiling determination control means for variably controlling the boiling detection time, which is a determining factor of the above.

According to the second aspect of the present invention, the amount of hot water is determined when the hot water mode is selected by the hot water mode selection switch, and the boiling detection time is variably controlled according to the amount of hot water. If the hot water temperature is within a predetermined temperature range during the detected boiling time, it is determined that the water is in a boiling state.

For example, if the boiling detection time variably controlled by the boiling determination control means is controlled to be long when the amount of hot water is large and short when the amount of hot water is small, Even when the amount of hot water is small, the boiling state of the hot water is immediately determined.

Further, in this case, if the heating power of the burner can be switched to low heat when the boiling determining means determines that the hot water is in a boiling state, the boiling state is reached. No wasteful gas consumption at the time and no empty burning.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram (control block diagram) of a gas table stove having a water heater function to which the present invention is applied. As shown in the figure, the gas table stove 10 is provided with a magnet safety valve 16 and a switching solenoid valve 18 from an upstream side of a main gas line 14 for supplying a fuel gas to a gas burner 12.
An auxiliary gas line 20 is provided which branches off from the main gas line 14 between the two electromagnetic valves 16 and 18 and joins on the downstream side of the switching electromagnetic valve 18.

In this case, the magnet safety valve 16 is an energization holding type solenoid valve. When the ignition / extinguishing switch 22 is pressed, a command signal is output from the microcomputer (microcomputer) 24 to the magnet safety valve driving circuit 26, and the magnet safety valve 16 Is held open.

On the other hand, the switching solenoid valve 18 is a self-holding solenoid valve (keep solenoid), which is temporarily energized to change from the open state to the closed state or from the closed state to the open state. , And the open / closed state is excitedly maintained. The switching electromagnetic valve 18 also outputs a command signal from the microcomputer 24 to the keep solenoid drive circuit 28 by the ignition operation of the ignition / extinguishing switch 22, and the switching electromagnetic valve 18 is turned on.
When the valve is open, the valve is switched to the closed state, and when the valve is closed, the valve is switched to the open state.

When the combustion is stopped and when the microcomputer is reset, a valve opening command signal is output from the microcomputer 24 to the keep solenoid drive circuit 28, and the switching solenoid valve 18 is kept open.

At the center of the gas burner 12, a temperature detector 34 for detecting the outer bottom temperature of the kettle 32 mounted on the gas burner 12 is provided. A flame detector 36 for detecting the flame of the gas burner 12 is provided, and is connected to the microcomputer via a temperature detection circuit 38 and a flame detection circuit 40, respectively. The display operation panel 46 of the gas table stove 40 is provided with a water heater mode and other mode setting switches. This will be described in detail in the description of FIG. A battery (3V) 44 is used for the power supply circuit 42 for supplying power to the microcomputer 24, the solenoid valve drive circuits 26 and 28, and the like.

FIG. 2 illustrates the display operation panel 46 of the gas table stove 10. As switches, a cooking mode switch 50 and a kitchen timer switch 52 are provided. The cooking mode includes a tempura mode, a water heating mode, and a rice cooking mode. In the tempura mode, the set temperatures are further set to 160 ° C, 180 ° C, and 200 ° C.
It is set in three stages of ° C. The kitchen timer is 3
The setting can be made in five stages of minutes, 5 minutes, 7 minutes, 10 minutes, and 15 minutes. The cooking mode switch 50 and the kitchen timer switch 52 are provided with a mode switch LED 54 and a timer switch LED 56 for displaying that these switches are turned on, and a 160 ° C. LED 58 for displaying the set temperature of the tempura mode. 180 ° C LE
D60, 200 ° C LED62, and hot water mode L
An ED 64 and a rice cooking mode LED 66 are provided, and these LEDs 58 to 66 are connected to the kitchen timer 3.
It is also used as a timer display for minutes, 5 minutes, 7 minutes, 10 minutes, and 15 minutes.

When the ignition / extinguishing switch 22 is turned on, the magnet safety valve 16 of the main gas line 14 is opened, and power is supplied from the battery 44 to the microcomputer 24 via the power supply circuit 42. 24 sends a signal to the magnet safety valve drive circuit 26 to
Is energized to hold the valve open. At this time, the self-holding switching electromagnetic valve 18 provided in the main gas pipeline 14 is already in the open state.

In this manner, the fuel gas is supplied to the gas burner 12 from both the main gas line 14 and the sub gas line 20, and the combustion operation is started by the ignition operation of the gas burner 12. In this case, the gas burner 12 has a main gas line 14.
Since the fuel gas is supplied from both the fuel gas and the auxiliary gas pipe 20, smooth ignition is performed by the ignition operation of the high heat.

After the ignition / extinguishing switch 22 is turned on to ignite, the water heater mode is selected by operating the cooking mode switch 50 of the display operation panel 46. At this time, every time the cooking mode switch 50 is pressed, the LED display on the display operation panel 46 switches between the tempura mode of 160 ° C., 180 ° C., 200 ° C., the water heating mode, and the rice cooking mode.
Turn on the cooking mode switch 50 with D64 lit
Stop the operation.

The temperature of the outer bottom of the kettle 32 placed on the gas burner 12 is detected one by one by the temperature detector 34, and a detection signal is sent to the microcomputer 24 via the temperature detection circuit 38. When the microcomputer 24 detects the boiling state at the detected temperature, it turns on the keep solenoid drive circuit 28 to switch to the minimum gas amount that can maintain the boiling state.
A / OFF signal is sent to open / close the switching electromagnetic valve 18.

That is, when the heating temperature of the kettle 32 detected by the temperature detector 34 reaches a temperature indicating a boiling state, the microcomputer 24 issues a valve closing command signal for the switching electromagnetic valve 18 and the switching electromagnetic valve 18 The valve is closed due to the temporary flow of electric current through the valve, the fuel gas does not flow through the main gas line 14, and a small amount of fuel gas is supplied only from the sub gas line 20. Will be a low heat.

FIG. 3 is a flowchart of the water heater mode. This is to switch to a small fire after detecting boiling, and extinguish the fire after the elapse of a water heater timer. Now, when the water heater mode is entered by the key selection of the cooking mode switch 50, the water heater mode LED 64 is turned on (S1), and the high limit temperature is set to 150 ° C. (S2). Then, according to the detection signal from the temperature detector 34, the detected temperature (T ₀ ) of the kettle 32 has exceeded T _W0 (85 ° C.) (S3, “YE
S ”), the timer is activated, and then the detected temperature (T ₀ ) exceeds T _W1 (95 ° C.) (S4,
The time until it is determined to be “YES” is counted (S
5) The boiling detection time (t _F ) is determined from the time taken (S6).

FIG. 4 shows the time required for the detected temperature (T ₀ ) of the kettle 32 to rise from 85 ° C. to 95 ° C. and the boiling detection time (t) required to determine whether or not the kettle is in a boiling state. _F ). According to this graph, for example, when the time until the detected temperature (T ₀ ) rises from 85 ° C. to 95 ° C. is 30 seconds or less, the boiling detection time (t _F ) rises from 15 seconds and from 85 ° C. to 95 ° C. In the case where the time until the heating is 120 seconds or more, the boiling detection time (t _F ) is set to 105 seconds, and the detection temperature (T ₀ ) is changed from 85 ° C. to 95%.
As shown in the figure, the boiling detection time (t _F ) is set in stages from 30 seconds to 120 seconds until the temperature rises to ° C.

After the boiling detection time (t _F ) is determined in S6, it is next determined whether or not a boiling state is present (S7). Here, it is determined whether or not the temperature rise is within ± 2 ° C. If the temperature of the kettle 32 detected by the temperature detector 34 is within ± 2 ° C. several times continuously, the kettle 32 is brought into a boiling state. .

Specifically, the temperature detection from the temperature detector 34 is performed.
Since the output signal is transmitted at one second intervals,
Is the average temperature (T_a) And calculate the average temperature
Degree T _aIs n₂Boiling when it enters within ± 2 ℃ continuously
It is determined that you are doing. This "n₂Times "illustration
As shown in Fig. 4, the detected temperature of the kettle 32 is from 85 ° C.
The time until the temperature rises to 95 ° C. is defined as “5 × n₁"
The boiling detection time (t_F) Is “5 × n₂(N₂= N
₁-3) ". I
So, for example, if the temperature of the kettle is 85 ° C for 40 seconds
When the temperature rises to 95 ° C, n₁= 8, n₂= 8-3
= 5 and the detected temperature (T₀) Averaged 5 times at 5 second intervals
If it is within ± 2 ° C, it is judged to be boiling
Things.

When it is determined in S7 that the kettle is in a boiling state (S7, "YES"), a signal is sent from the microcomputer 24 to the solenoid drive circuit 28 to turn off the switching electromagnetic valve 18 (S8). Then, a buzzer sound is issued to notify the user (S9). If five minutes have elapsed (S10, "YES"), a signal is sent from the microcomputer 24 to the magnet safety valve drive circuit 26, the magnet safety valve 16 is closed to extinguish the fire (S11), and the switching electromagnetic valve is turned off. A buzzer sound different from the time is issued to notify the user of the buzzer sound (S12), and the switching solenoid valve 18 is controlled by the microcomputer so that ignition is performed only by opening the magnet safety valve 16 at the next ignition operation. The valve is kept open by the command signal from S24 (S13).

In S3, the kettle detection temperature (T ₀ ) does not exceed T _W0 (85 ° C.) (S3,
When it is determined to be “NO”, n ₂ = 6 times (t _F = 30
(Seconds) (S14), thereby determining whether or not the kettle is in a boiling state by adding the average value of the detected temperature (T ₀ ) of the kettle at intervals of 5 seconds six times and averaging it (S7). ing. If the amount of hot water in the kettle is too small, the kettle may suddenly be brought into a boiling state. In such a case, boiling can be predicted from a temperature state of 85 ° C. or less.

In this flowchart, S2 and S
3, a cancel interrupt signal can be input. For example, when hot water is added to the kettle, or when the detected temperature (T ₀ ) of the kettle has dropped to 85 ° C., the process proceeds to S3 and the detection of the boiling state is continued.

Thus, as described in the above embodiment, T _WO (85) is used to detect the boiling state of the hot water in the kettle 32.
C.) to T _W1 (95 ° C.), the time (t _F ) required for the hot water temperature to rise, and if the time (t _F ) is long, the kettle 32 has a large amount of hot water and the t _F is short. In this case, based on the determination that the amount of hot water is small, the boiling state is reached at an early stage when the amount of hot water is small, so that the boiling state is determined in a short time. When the amount of hot water is large, the boiling is not so quick, so that the determination of the boiling state is also performed over a relatively long time.

The present invention is not limited to the above-described embodiment at all, and various modifications can be made without departing from the gist of the present invention. For example, in the above embodiment, the boiling detection is performed when the hot water temperature is between 85 ° C. and 95 ° C. However, the detection temperature and the detection temperature range are not understood at all, and the boiling temperature (100 ° C.) Slightly lower, for example, 90 ° C. to 95 ° C., or other conditions may be set, and the detection temperature range is not limited to ± 2 ° C., for example, ± 3 ° C. May be changed as appropriate, for example, by judging whether or not the temperature range has been exceeded. Further, in the description of FIG. 4 described above, the number of times of boiling detection is set stepwise at intervals of 5 seconds, but may be set linearly.

[0035]

According to the heating cooker of the present invention, in order to detect the boiling state of the hot water when the hot water mode is set, there is a difference in the temperature rise gradient due to the large and small amount of the hot water. Since the boiling state is determined in a short time, an appropriate boiling state can be maintained according to the amount of hot water.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a gas table stove as one embodiment of the present invention.

FIG. 2 is a view showing a display operation panel surface of the gas table stove;

FIG. 3 is a control flowchart of the present invention.

FIG. 4 is a diagram showing a rise time (T) of a hot water temperature for realizing the present invention.
Is a diagram showing the relationship between _W0 → _{T W1)} and boiling determination time _{(t F).}

FIG. 5 is a diagram illustrating a tendency of a rise in hot water temperature depending on the amount of hot water in a kettle;

[Explanation of symbols]

 Reference Signs List 10 gas table stove 18 switching solenoid valve 24 microcomputer (microcomputer) 32 kettle 34 temperature detector 46 display operation panel 50 cooking mode switch 64 water heater mode LED

Claims (4)

[Claims] 1. A heating cooker having a water heating function, comprising: a hot water temperature detecting means for detecting a hot water temperature; and a boiling state when the hot water temperature detected by the hot water temperature detecting means is within a predetermined temperature range for a predetermined time. A boiling amount judging means for judging that there is water, and a hot water amount judging means for judging the amount of hot water, and a boiling detection time which is a judging element of the boiling judging means is variably controlled according to the amount of hot water judged by the hot water amount judging means And a boiling determination control means. 2. A heating cooker having a water heater function, comprising: a water heater mode selecting switch; a water amount determining means for determining the amount of water when the water heater mode is selected by the water heater mode selecting switch; A boiling judging means for judging that a boiling state is present when the temperature is within a predetermined temperature range; and variably controlling a boiling detection time which is a judging element of the boiling judging means depending on the amount of hot water judged by the hot water judging means when selecting the hot water mode. And a boiling determination control means. 3. The method according to claim 1, wherein the boiling detection time variably controlled by the boiling determination control means is controlled so as to be long when the amount of hot water is large and to be short when the amount of hot water is small. Cooking cooker. 4. The heating cooking device according to claim 1, further comprising: a heating power switching means for reducing a heating power of a burner when the boiling determining means determines that the hot water is in a boiling state. vessel.