JPH05269041A - Heat-keeping pot - Google Patents

Abstract

PURPOSE:To prevent hot-water in a pot from boiling and save energy by a method wherein heat-keeping action is carried out so that the temperature of hot-water is always kept below the boiling point and a heater is intermittently energized during heat-keeping action. CONSTITUTION:A user selects and sets a desired heat-keeping temperature with a heat-keeping temperature setting device 8 and then turns a power source on. A heater driver 1 is brought into action by a water heating controller and power is continuously supplied to a heater to heat water or hot-water in a pot. When the hot-water temperature exceeds a specified value T1 (for example, 90 deg.C) and remains almost unchanged, boiling state is detected. The temperature detected by a temperature detector 7 when the boiling state is detected is stored in a boiling temperature memory 5 as a boiling temperature X. After that, heat-keeping action takes place. In the case the heat-keeping set temperature is 75 deg.C or 85 deg.C, heat-keeping action is carried out so as to keep the set temperature. Since the boiling temperature is at least 90 deg.C, the heater is intermittently energized during the heat-keeping action.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat retaining pot.

[0002]

2. Description of the Related Art In a conventional heat-retaining pot, when a power source is turned on, a heater is continuously energized and is heated by heating the heater. Then, when the temperature rise almost disappears, it is determined that the boiling state is reached. Then, the energization of the heater is controlled so as to maintain the preset heat retention temperature, and the heat retention operation starts.

Generally, the boiling point of water is about 100.degree. Therefore, when the control temperature during the heat retention operation, that is, the so-called heat retention temperature is set to 95 ° C., the temperature is conventionally controlled with the characteristic shown in FIG. That is, when the boiling water temperature is raised to about 100 ° C. by the boiling water operation and the boiling state is detected at time m (minutes), the warming operation is started. At this time, since the heat retention temperature is 95 ° C., the energization of the heater is once turned off. When the hot water temperature drops to around 95 ° C, the heater is turned on again. After that, the heater is turned on and off repeatedly, and the hot water temperature is controlled so as to maintain the heat retention temperature of 95 ° C.

However, it is known that the boiling point of water changes under the influence of atmospheric pressure. Therefore, depending on the usage environment, there may occur a phenomenon in which the boiling point becomes lower than the heat retention temperature.

FIG. 4B shows the control characteristics when the heat retention temperature is set to 95 ° C. and the boiling point is 94 ° C. That is, the boiling water temperature rises to about 94 ° C due to the boiling water operation.
When the boiling state is detected at time m (minutes), the heat retention operation is started. At this time, since the heat retention temperature is 95 ° C., the energization of the heater is not turned off. Since the hot water temperature does not rise to the heat retention temperature forever, the heater energization state is continued.

[0006]

As described above, in the conventional heat-retaining pot, when the boiling point is lowered due to the use environment, the heater energization state is continued even after the heat-retaining operation depending on how the heat-retaining temperature is set. There was a problem that was boiled.

Therefore, according to the present invention, the heat retaining operation can be controlled at a temperature lower than the boiling temperature at all times, so that the heater can be energized intermittently during the heat retaining operation, and there is no fear that the hot water in the pot will boil. Moreover, it is intended to provide a heat-retaining pot that can save power.

[0008]

According to the present invention, a boiling state is detected by the boiling detecting means in a heat retaining pot which is operated by heating a heater to bring the water into a boiling state, and when the boiling detecting means detects the boiling state, the heat retaining operation is started. A boiling temperature detecting means for detecting the hot water temperature at that time, a warming temperature setting means for setting a temperature lower than the boiling water temperature detected by this means by a predetermined value as a warming temperature, and a warming temperature set by this setting means A heat retention control means for controlling the heat retention operation depending on the temperature is provided.

[0009]

In the heat-retaining pot having such a structure, the boiling water is operated by heating the heater, and when the boiling state is detected by the boiling detection means, the hot water temperature at that time is detected. Then, a temperature lower than the boiling water temperature by a predetermined value is set as the warming temperature, and the warming operation is started, and the hot water temperature is controlled so as to maintain the warming temperature. Therefore,
In this heat-retaining pot, the heat-retaining temperature is always lower than the boiling temperature by a predetermined value, so that the energization of the heater is intermittently controlled during the heat-retaining operation.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a control circuit of the heat retaining pot. The heater driving unit 1 energizes a heater for heating water or hot water in the pot. The water heating controller 2 controls the on / off of energization of the heater in the heater driving unit 1 to control the water heating operation of the heat retaining pot. The heat retention controller 3 controls ON / OFF of energization of the heater in the heater driving unit 1 to control the heat retaining operation of the heat retaining pot.

The pot control unit 4 is composed of a microcomputer and constitutes the control unit main body of the heat retaining pot. The pot control unit 4 controls the operations of the boiling water control unit 2 and the heat retention control unit 3 according to a preset procedure.

The pot control section 4 includes a boiling temperature storage section 5 formed of a volatile memory such as a RAM (random access memory) and a ROM (read only memory) or an EEPROM (electrically erasable programmable ROM). )
And the adjusted temperature storage unit 6 formed of a non-volatile memory.

A hot water temperature detecting unit 7 for detecting the hot water temperature in the pot and a warming temperature setting unit 8 for manually setting a control temperature during a warming operation, that is, a warming temperature are connected to the pot control unit 4. .. The heat retention temperature setting unit 8 can manually set any one of the three heat retention temperatures of 95 ° C., 85 ° C., and 75 ° C. manually.

Thus, the pot controller 4 executes the process shown in FIG. 2 when the power is turned on. First, in step ST1, the water heating controller 2 is operated to control the water heating operation of the heat retaining pot.

Next, at ST2, the detection signal of the hot water temperature detecting unit 7 is read to check the hot water temperature at the present time. Then, the hot water temperature has a constant value T1 (eg 90
If the temperature is less than 0 ° C), the control of the boiling water operation of ST1 is continued.

At ST2, the hot water temperature at present is the above-mentioned constant value T1.
When the above is reached, the temperature difference ΔT between the hot water temperature at a predetermined time (for example, 2 minutes before) and the hot water temperature at the present time is calculated as ST3. Next, at ST4, the temperature difference ΔT is compared with a preset constant value T2 (for example, 2 ° C.). When the temperature difference ΔT is equal to or greater than the constant value T2, it is determined that the hot water in the pot has not reached the boiling point yet, and the control of the hot water boiling operation in ST1 is continued.

When the temperature difference ΔT becomes smaller than the constant value T2 in ST4, it is determined that the hot water in the pot is in a boiling state (boiling detection means), and the current temperature of the hot water temperature detection unit 7 is determined as ST5. The detected temperature at is stored in the boiling temperature storage unit 5 as the boiling temperature X. (Boiling temperature detection means)

Next, in ST6, the heat retention temperature set by the heat retention temperature setting unit 8 is checked. Here, when the preset temperature is 75 ° C, the retained temperature is determined to be 75 ° C as it is. Further, even when the set temperature for keeping warm is 85 ° C., the temperature for keeping warm is set to 85 ° C.

On the other hand, when the preset temperature is 95 ° C., the adjusted temperature t set in advance in the adjusted temperature storage unit 6 is calculated from the boiling temperature X stored in the boiling temperature storage unit 5.
The temperature obtained by subtracting is determined as the heat retention temperature. (Heat retention temperature setting means) Then, in ST7, the heat retention controller 3 is operated to
The heat retention operation at the determined heat retention temperature is controlled. (Heat retention control means)

When using the heat retaining pot of the present embodiment having the above-described structure, the user turns on the power after selecting and setting a desired heat retaining temperature by the heat retaining temperature setting section 8.
Then, the heater driving unit 1 operates under the control of the boiling water control unit 2, and the heater is continuously energized to heat the water or hot water in the pot.

When the temperature of the hot water in the pot exceeds a constant value T1 (for example, 90 ° C.) and hardly changes, the boiling state is detected. The temperature detected by the hot water temperature detector 7 when the boiling state is detected is the boiling temperature X.
Is stored in the boiling temperature storage unit 5.

After that, the heat retaining operation is started. Here, when the heat retention set temperature is 75 ° C. or 85 ° C., the heat retention operation is performed so as to maintain the set temperature. Since the boiling temperature is at least 90 ° C. or higher, the heater is energized intermittently in this heat retention operation.

On the other hand, when the preset temperature is 95 ° C,
The temperature is controlled with the control characteristics shown in FIG. That is, when the boiling water temperature is raised to the boiling point by the boiling water operation and the boiling state is detected at time m (minute), the warming operation is started. At this time, the heat retention temperature is controlled to a temperature Y obtained by subtracting the adjusted temperature t from the boiling temperature X. Therefore, even in this heat-retaining operation, the heater is energized intermittently.

As described above, according to this embodiment, when the heat retention temperature is set to 95 ° C., the heat retention operation is controlled so as to always maintain the heat retention temperature Y which is lower than the boiling temperature X by the adjustment temperature t. It

For example, when the adjusted temperature t is 5 ° C., the heat retaining operation is controlled so that the heat retaining temperature 95 ° C. is maintained when the boiling temperature X is 100 ° C. Further, when the boiling temperature X is 94 ° C., for example, the heat retaining operation is controlled so as to maintain the heat retaining temperature of 89 ° C.

Therefore, the boiling point may be lower than the heat retention set temperature depending on the use environment as in the latter example. However, even in such a case, the heater is energized intermittently during the heat retention operation. No hot water will be boiled and can be kept warm at an appropriate temperature. Also, the effect of saving electricity is great.

Although the adjustment temperature is set to 5 ° C. in the above embodiment, it is needless to say that the adjustment temperature is not limited to this. For example, when the adjustment temperature t is set to a small value of 3 ° C., the heat retention temperature is 95 ° C. when the boiling temperature is 98 ° C., but the heat retention temperature is 97 ° C. when the boiling temperature is 100 ° C. That is, if the boiling temperature is high, the heat retention set temperature (in this case, 9
The temperature can be maintained at a temperature higher than 5 ° C.), and the temperature can be maintained while the heater is intermittently operated at a temperature close to the boiling state.

Further, the adjustment temperature t may be varied depending on the boiling temperature X. For example, when the boiling temperature X is 98 ° C. or higher, the adjustment temperature t is set to 3 ° C., and the boiling temperature X is 95%.
If the boiling temperature X is less than 95 ° C, the adjusted temperature t is set to 2 ° C. By doing so, it becomes possible to maintain an appropriate heat retention temperature according to the boiling temperature. Of course, various modifications can be made without departing from the scope of the present invention.

[0030]

As described above in detail, according to the present invention, the heat retaining operation can be controlled at a temperature lower than the boiling temperature at all times, so that the heater can be energized intermittently during the heat retaining operation. It is possible to provide a heat-retaining pot in which there is no fear that the hot water will boil up and power can be saved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a control circuit according to an embodiment of the present invention.

FIG. 2 is a flowchart showing main control of a pot control section in the embodiment.

FIG. 3 is a diagram showing a control characteristic in the example.

FIG. 4 is a diagram showing control characteristics in a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heater drive part, 2 ... Boiling control part, 3 ... Heat retention control part, 4 ... Pot control part, 5 ... Boiling temperature adjustment part, 6 ... Adjusted temperature storage part, 7 ... Hot water temperature detection part, 8 ... Heat retention temperature setting Department.

Claims (1)

[Claims] 1. A warming pot which is operated by heating a heater to bring into boiling water, and when a boiling state is detected by a boiling detecting means, a warming operation is carried out to detect a hot water temperature when the boiling state is detected by the boiling detecting means. Boiling temperature detecting means, heat retaining temperature setting means for setting a temperature lower than the boiling temperature detected by this means by a predetermined value as the heat retaining temperature, and the heat retaining operation is controlled by the heat retaining temperature set by this setting means. A heat-retaining pot, comprising: