JP2000126036A - Electric pot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To regularly keep hot water at a high temperature close to the boiling point with a simple circuit structure by switching the heat retaining temperature according to the operation quantity of current carrying or interruption of a heating means for a prescribed time, and controlling the current carrying to the heating means so as to keep the hot water temperature at this switched heat retaining temperature to perform the heat retaining operation. SOLUTION: A control means 6 calculates and sets the heat retaining temperature from the hot water temperature in water boiling. When a heat retaining operation is started without boiling water after input of a power source, the current carrying to a heat retaining heater 3 is controlling so as to keep the hot water temperature at a preset prescribed heat retaining temperature to perform the heat retaining operation, and a time clocking is also performed by a timer means 15. On this time clocking, the heat retaining temperature is switched according to the operation quantity of current carrying or interruption of the heat retaining heater 3 for a prescribed time. More specifically, the heat retaining temperature is successively switched until the operation quantity reaches a prescribed quantity, and the current carrying to the heat retaining heater 3 is controlled so as to keep the hot water temperature at the switched heat retaining temperature to perform the heat retaining operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric pot provided with a heating means for heating water in a container to boil the water and keeping the boiling water warm.

[0002]

Conventionally, in an electric pot, the heat retention control has been performed as follows. The first shown in FIG.
The method (1) controls the heat retaining operation based on preset temperature data. This temperature data, that is, the heat retention temperature is 96
It is set around ℃. This is to prevent boiling from continuing in the heat retaining operation even when used in a place where the outside air pressure is low. That is, the temperature is set to about 96 ° C., which is lower than the boiling point of water at high altitudes, assuming that it is used at high altitudes. In FIG. 6, steps S1 and S2 indicate that if there is a power failure, the operation is resumed after the recovery from the power failure. If the temperature of the hot water is lower than 90 ° C. after the recovery from the power failure, the boiling LED is turned on (steps S3 and S4), and the water heating operation is performed (step S5). When the water heating is completed, the boiling LED is turned off (steps S6 and S7), and the heat keeping LED is turned on (step S8), and 96 ° C. is set as the heat keeping temperature (step S9). Is performed (step S10). That is, the hot water temperature is almost 96
Perform the heat retention operation so that the temperature is maintained at ° C. On the other hand, if the hot water temperature after the recovery from the power failure is 90 ° C. or higher, the process proceeds to step S8, and the warming operation is immediately performed. In addition, after step S3, the same applies not only after the restoration from the power failure but also at the time of water heating after the power is turned on.

A second method shown in FIG. 7 is to control the heat keeping operation at about 98 ° C. as a high temperature heat keeping. In this case, the setting of the heat retention temperature data is based on the temperature of the water at the time of boiling or after the boiling so that the heat retention temperature is higher than the boiling point of the water so that the boiling operation of the hot water does not continue even if the volume of the hot water or the external pressure fluctuates. The heat retention temperature data is set so as to be lower.
In FIG. 7, steps S11 and S12 indicate that when a power failure occurs, the operation is resumed after the recovery from the power failure. If the temperature of the hot water is lower than 90 ° C after the recovery from power failure, boiling L
The ED is turned on (steps S13 and S14), and the water heater is operated (step S15). Here, when the boiling is detected, the operation is switched to the weak boiling operation (steps S16 and S17). Note that the weak boiling operation is to turn off the water heater and continue the boiling state with the heater having a lower output.
Then, the heat retention temperature is calculated from the boiling hot water temperature and set as the heat retention temperature (step S18), and the data of the heat retention temperature is stored in a memory IC such as an EEPROM (step S19). Further, the boiling is continued until the boiling is completed (steps S20 and S21). When the boiling is completed,
The boiling LED is turned off (steps S21 and S22). And
The warming LED is turned on (step S23), and the step S1 is performed.
8, a warming operation is performed based on the warming temperature set in S19 (step S24). On the other hand, if the hot water temperature after the recovery from the power failure is 90 ° C. or higher, the warming operation is immediately performed.
Is transferred to the microcomputer (microcomputer) and set as the heat retention temperature (steps S13, S25). Then, the warming LED is turned on (step S23), and the warming operation is performed based on the warming temperature set in step S25 (step S24). Step S13
Thereafter, the same applies not only after recovery from the power failure but also at the time of water heating after the power is turned on.

[0004] In the first method, the heat retention temperature is stored in a ROM of a microcomputer, and even if the microcomputer is reset due to a power failure, control is performed based on the same data stored in the ROM after the power is restored. Things. However, the control data is absolute temperature data that does not depend on conditions, and high-temperature data cannot be set due to the relationship with the boiling point.
Therefore, it was not possible to increase the heat retention temperature of the hot water. For example, if the data is set so as to keep the temperature at 98 ° C in a plain area with a low altitude, the boiling point will decrease because the atmospheric pressure is low in a mountainous area with a high altitude, and if the temperature is kept at the same temperature data, the boiling will continue. It can happen. In addition, since the control data is absolute temperature data, even if the control data is the same due to differences in the capacity of hot water, differences in the characteristics of thermistors and circuits for temperature detection, or in other conditions,
The actual temperature of the hot water in the container was sometimes different.

When the heat retention temperature is increased, in a place where the outside air pressure is low as described above, even if the hot water boils, it does not reach the set heat retention temperature due to the low boiling point, and the energization rate of the heat retention heater during the heat retention is reduced. It becomes high, electricity is continued,
It is dangerous and wastes electricity.

On the other hand, in the second method, the heat retention temperature data is relative data set based on the temperature of the hot water at the time of boiling or after the boiling. That is, this data is not data stored in the ROM of the microcomputer, but is calculated after, for example, boiling detection, stored in the RAM of the microcomputer, and used for control. For this reason, when the microcomputer is reset due to a power failure or the like, the set data is erased. Therefore, if the warming operation is performed without water heating after the recovery from the power failure, the warming temperature data as shown in FIG. If the backup is not performed, the correct heat retention temperature will not be set because the boiling operation is not passed, and a predetermined heat retention temperature will be set. As a result, the warming operation is controlled by data different from that before the power failure, and the warming temperature before the power failure cannot be maintained, and the warming may be performed at a different hot water temperature than before the power failure. This is inconvenient for the user.

To avoid such a problem, FIG.
As shown in (2), by storing the set warming temperature data in the EEPROM which is a non-volatile memory means, or by backing up the power supply of the microcomputer by a backup means such as a battery and retaining the data, there is a power failure. Also,
After the power failure was recovered, the temperature was kept at the same level as before the power failure, so that the hot water could always be kept at a high temperature close to the boiling point. However, the use of the EEPROM or the backup means has a problem that the circuit configuration becomes complicated and the number of parts increases, resulting in an increase in cost.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide an easy-to-use electric pot which can keep hot water at a high temperature close to the boiling point with a simple circuit configuration. .

[0009]

In order to achieve the above object, the present invention provides a container for storing water, a heating means for heating water in the container to boil water and keeping the boiling water warm. Temperature detecting means for detecting the temperature of water in the container, time measuring means for measuring time, storage means for storing a predetermined heat-retaining temperature, and various operations including controlling the above-described means and water heating and heat-retaining. When the heat retaining operation is started without water heating after the power is turned on, the power supply to the heating means is controlled so as to maintain the temperature of the hot water at a predetermined temperature. Performing the operation and measuring the time by the time measuring means, switching the heat retaining temperature according to the operation amount of energization or disconnection of the heating means for a predetermined time, and maintaining the temperature of the hot water at the switched thermal retaining temperature. To the heating means It is obtained by configured to perform heat keeping operation control to the electric.

[0010] When the heat retaining operation is started at the preset predetermined heat retaining temperature, for example, in a plain area having a low altitude, the boiling point is high, so that the temperature of the hot water can also be high. The amount is reduced. In such a case, the heat retaining temperature may be increased. On the other hand, at a high altitude at a high altitude, the boiling point is low, so that the temperature of the hot water cannot be higher than the boiling point. Therefore, the amount of energization of the heating means increases. In such a case, the heat retaining temperature may be lowered so that the boiling state is not continued despite the heat retaining operation.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the electric pot of the present invention will be described below with reference to FIGS. FIG.
In the block diagram shown in FIG. 1, reference numeral 1 denotes a container for storing water to be heated. Reference numeral 2 denotes a water heater serving as a heater for heating water or hot water in the container 1 during the water heating operation. Reference numeral 3 denotes a heat retention heater as a heat retention heating means which is a heating means for keeping the boiling water in the container 1 warm during the heat retention operation. Note that heating by the water heater 2 is stronger than heating by the heat retaining heater 3. Reference numeral 4 denotes a heater heater energizing means for energizing the water heater 2, and reference numeral 5 denotes a warming heater energizing means for energizing the warming heater 3.

Reference numeral 6 denotes a control means comprising a microcomputer for performing various controls. An output signal from the control means 6 is transmitted to the heater energizing means 4 and 5 via an output means 7. Reference numeral 8 denotes a display means, and the display means 8
Boiling LED, which is a lamp indicating an operation state, and heat retaining LE
D and the like. An output signal from the control means 6 is transmitted to the display means 8 via the output means 7. Reference numeral 9 denotes key input means. The key input means 9 includes an operation key (re-boil key) for starting water heating by operating during heat retention. Each operation signal from the key input means 9 is input to the control means 6 via the input means 11.

Reference numeral 12 denotes a hot water temperature sensor comprising a thermistor. The temperature data from the hot water temperature sensor 12 is supplied to a control means 6 via a temperature detecting means 13 for detecting the temperature of water in the container 1 based on the temperature data. Is input to Further, reference numeral 14 denotes storage means such as a ROM or a RAM for storing predetermined heat retention temperature data, and reference numeral 15 denotes a time keeping means for keeping time. And
The control means 6 controls the heater energizing means 4, 5 and the display means 8 in accordance with the inputs from the temperature detecting means 13, the storing means 14, the time keeping means 15 and the input means 11, and various types including the water heater and the heat retention. Perform the operation. As will be described in more detail later, the control means 6 calculates and sets the heat retention temperature from the hot water temperature at the time of water heating. When the heat retaining operation is started without water heating after the power is turned on, the heat retaining operation is controlled by controlling the energization of the heat retaining heater 3 so as to maintain the temperature of the hot water at a predetermined heat retaining temperature. Means 15
The time is measured by. Then, based on the timing, the heat retention temperature is switched according to the operation amount of energization or cutoff of the heat retention heater 3 for a predetermined time, and more specifically, the heat retention temperature is sequentially increased until the operation amount becomes a predetermined amount. Then, the power supply to the heat retention heater 3 is controlled so as to maintain the temperature of the hot water at the switched heat retention temperature, and the heat retention operation is performed.

Next, the operation of the electric pot of this embodiment will be described with reference to the flowcharts of FIGS. In FIG. 2, steps S31 and S32 indicate that when a power outage occurs, the operation is resumed after the recovery from the power outage. After the recovery from the power failure, step S33 and subsequent steps are executed, and the same applies when the power is turned on by a user's operation. That is, when the power is turned on, if the hot water temperature T0 <90 ° C., the water heating operation is started. The display means 8 turns on the boiling LED to indicate that the water heater is being operated (step S34). In addition, both the water heater 2 and the heat retention heater 3 are energized to heat the water in the container 1 and perform the water heating operation (step S35). During this water heating operation, the detection of boiling is performed (step S36). The detection of the boiling is performed based on the temperature data from the hot water temperature sensor 12. When the boiling is detected, the power supply to the water heater 2 is stopped, while the display of the water heater is continued, the power supply to the heat retaining heater 3 is continued, and the weak boiling state is continued (step S37). The control temperature during the heat retention is calculated and set based on the hot water temperature during the weak boiling state (step
S38). Since the control temperature set here, that is, the warming temperature, is based on the boiling water temperature, a temperature close to the boiling point can be set as the warming temperature. Then, since the setting is made for each water heater, the heat retention temperature can be set according to the conditions at the time of water heating without being influenced by the volume of the water or the external pressure, and a temperature closer to the boiling point can be set. For example, it can be about 98 ° C in plains. Here, the weak boiling state is continued for 3 minutes (step S39),
The temperature at the time of boiling is maintained by the warming heater 3, and after 3 minutes, the water heater is stopped, the boiling LED is turned off, and the warming LED is turned on to display the warming (step S4).
0, S41), the power supply to the heat retaining heater 3 is also stopped. Thereafter, according to the temperature data from the hot water temperature sensor 12, power is cut off through the heat retaining heater 3 so as to maintain the heat retaining temperature (for example, 98 ° C.) set during the weak boiling state, and the temperature is maintained (step S42).

On the other hand, when the power is turned on, the hot water temperature T0 ≧ 90 ° C.
In the case of, the warming operation is started. During the warming operation, the display means 8 turns on the warming LED to perform the warming display (step S4).
3) In addition, the hot water in the container 1 is kept at a predetermined temperature by turning off the power to the heater 3. Since the microcomputer has been reset by turning off the power, the heat retention temperature set at the time of water heating before the power failure has been erased. Therefore, predetermined heat retention temperature data (for example, 98 C.) is set as the heat retention temperature (step S44). That is, first, the absolute value data of 98 ° C. is set as the heat retention temperature, and the counter of the timer unit 15 is cleared (step S45), and the timer starts. Then, a heat insulation operation is performed at a heat insulation temperature of 98 ° C. (step S4).
6) While continuing to count by the counter of the time counting means 15 (step S47), the control means 6 determines whether the operation being performed by the control means 6 is during energization of the heat retaining heater 3 or during interruption of power. I do. When 20 minutes have elapsed since the counter started counting, the energizing operation of the heater 3 was 80% within the 20 minutes.
It is determined whether or not it is above (steps S48, S4
9) If it is not less than 80%, the heat retention temperature is reset to 96 ° C. (step S50), and the heat retention operation is performed using the newly set heat retention temperature (step S42).

FIG. 4 and FIG. 5 show the change over time of the hot water temperature, the ON / OFF of the heat retaining heater 3, that is, the power cutoff and the operation. FIG. 4 shows a case of a plain at a low altitude, and FIG. 5 shows a case of a high altitude at a high altitude.

As shown in FIG. 4, in a plain area where the altitude is low,
Since the boiling point is high (about 100 ° C), if the water is boiled, the temperature of the hot water will reach the set temperature of 98 ° C. During the heat keeping, the heat keeping heater 3 is turned on and off so as to keep the hot water temperature at 98 ° C. Since the heat retention heater 3 turns off and on during the predetermined time of 20 minutes, the energizing operation time is shortened, and the ratio of energizing operation is reduced.

On the other hand, as shown in FIG. 5, at a high altitude where the altitude is high, the boiling point is low because the outside air pressure is low, so that even if the hot water is boiled, it does not reach the initially set heat retention temperature of 98 ° C. During the heat retention, the temperature does not reach 98 ° C. set as the heat retention temperature, so that the heat retention heater 3 is kept on. In this way, if the operation time for energizing the heat retaining heater 3 during the predetermined time of 20 minutes is 80% or more, it is determined that the initially set heat retaining temperature of 98 ° C. is too high, and the heat retaining temperature is set to be too high. Change to 96 ° C. Thereafter, a warming operation is performed so as to keep the hot water at a warming temperature of 96 ° C.

During the heat retention, a reboil operation is performed by operating the reboil key of the key input means 9, or when the water temperature becomes lower than 90 ° C., the water heating is started, and a series of water heating operations are performed. When the heat retention operation is performed again after the setting, the heat retention operation is performed so as to keep the hot water at the heat retention temperature set during the water heating.

According to the configuration of the embodiment, in order to keep the temperature at a temperature close to the boiling point, in addition to obtaining the warming temperature from the hot water temperature during weak boiling at the time of boiling water, the high hot water temperature makes it possible to immediately maintain the temperature after turning on the power. Even when the warming operation is performed, the warming temperature is switched by the energizing operation amount of the warming heater 3 for a predetermined time during the warming operation, so that the warming temperature set at the time of the water heating can be stored, or the operation or setting can be performed. Even if the power of the microcomputer is not backed up in order to retain the data thus obtained, the temperature can be maintained at a temperature close to the boiling point after the power failure as before the power failure. Further, even when conditions such as the volume of hot water in the container 1 and the external pressure change, the temperature can be maintained at a temperature close to the boiling point.

Since there is no need for a means for storing the heat retention temperature set based on the hot water temperature or a means for backing up the power supply of the microcomputer, the number of parts in the circuit configuration can be reduced, the circuit configuration can be simplified, and the cost can be reduced. Can be reduced.

Also, after the power failure is recovered, the temperature is not maintained by the data set before the power failure, but the warming temperature is set from the hot water temperature at the time after the power failure is recovered. Even if the environment changes, an appropriate heat retention temperature can be set. Therefore, the heat retention temperature becomes higher than the boiling point,
It is safe without boiling continuing. Also,
Since the boiling point is low, the temperature of the hot water does not rise to the set heat retaining temperature, the power supply rate of the heat retaining heater 3 does not increase, and the power supply does not continue. Thus, the safety and the energy saving effect can be obtained. Further, when the temperature of the hot water kept low after the power failure is restored, the temperature of the hot water is not forcibly raised to the high heat retention temperature set before the power failure, so that there is no needless power supply to the heat retaining heater 3 and energy saving. become.

Further, a storage means (for example, EEP) external to the microcomputer for storing the heat retention temperature set during the water heating.
Since there is no need to exchange data with the ROM, data errors and the like due to data exchange are eliminated.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, when the heat retaining operation is started without water heating after the power is turned on, the heat retaining temperature is switched twice, but the heat retaining temperature may be switched any number of times. For example, after setting the heat retention temperature to 98 ° C. first, the heat retention temperature may be switched by providing finer steps of 97 ° C. and 96 ° C. Further, the set temperature may be made fine.

In the above embodiment, the higher temperature (98
C) to the lower temperature (96 ° C), but the heat retention temperature may be set from the lower to the higher temperature. For example, first, 96 ° C. is set to perform the heat retaining operation, and if there is no energizing operation to the heat retaining heater 3 within a predetermined time, the hot water temperature is assumed to be higher than the set value (96 ° C.), and the set heat retaining temperature is increased. You may do so.

Further, in the above-described embodiment, as the operation amount of the heating means, which is a condition for switching the heat retention temperature, the time during which the control means 6 switches off the power to the heat retention heater 3 is used. You may. For example, a heat-retention heater power-on detecting means or the like for detecting the power cutoff of the heat-retention heater 3 may be provided to detect the power supply amount of the heat-retention heater 3.

Further, the temperature (96
The temperature (° C., 98 ° C.), the time (20 minutes), the amount of electricity (80% ON) and the like are appropriately changed depending on the product type and the like.

The storage means 14 for storing the heat retention temperature data is not limited to the ROM of the microcomputer, and other means can be used. For example, a nonvolatile storage element such as an EEPROM may be used.

Further, the notification of each operation such as the water heating operation and the heat retention operation is not limited to the display by the LED as in the above-described embodiment, and other notification means may be used. For example, the information may be displayed on an LCD or the like. Further, the notification of the switching of the operation from the water heater to the heat retention is performed by switching the display of the LED, but may be performed by another means such as a buzzer.

Further, in the above-described embodiment, the heating means is divided into the water heater 2 and the heat retaining heater 3, but this is not essential, and both the water heating and the heat retention can be performed by the same heater.

[0031]

According to the electric pot of the present invention, when the warming operation is started without water heating after turning on the power, the heating means is energized so as to keep the temperature of the hot water at a predetermined temperature. To control the temperature and time keeping by the time keeping means, and switch the keeping temperature according to the amount of energization or disconnection operation of the heating means for a predetermined time, and keep the temperature of the hot water at the switched keeping temperature. Since the heat retaining operation is performed by controlling the power supply to the heating means as described above, the heat retaining temperature can be made appropriate in accordance with various conditions such as a difference in boiling point due to a difference in altitude or a capacity of hot water in the container. In addition, even in the case of a power failure, the heat retention temperature can be appropriately switched after the power failure is restored, and therefore, there is no need for a power supply backup unit or the like for maintaining the set and stored heat retention temperature even during the power failure. The circuit configuration can be simplified. In this way, it is possible to provide an easy-to-use electric pot that can keep hot water at a high temperature close to the boiling point with a simple circuit configuration.

[Brief description of the drawings]

FIG. 1 is a system block circuit diagram showing one embodiment of an electric pot of the present invention.

FIG. 2 is a flowchart showing the same operation.

FIG. 3 is a flowchart showing the same operation.

FIG. 4 is a graph showing a change over time of the same hot water temperature,
This shows the case where the heat retention temperature is ≧ 98 ° C. (flat ground).

FIG. 5 is a graph showing a change over time of the same hot water temperature,
The case where the heat retention temperature is less than 98 ° C. (high altitude) is shown.

FIG. 6 is a flowchart showing an operation in an example of a conventional electric pot.

FIG. 7 is a flowchart showing an operation of another example of the conventional electric pot.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Water heater (heating means) 3 Heating heater (heating means) 6 Control means 13 Temperature detection means 14 Storage means 15 Clocking means

Claims (1)

[Claims] 1. A container for storing water, a heating unit for heating the water in the container to boil the water and keeping the boiled water warm, a temperature detecting unit for detecting the temperature of the water in the container, A timer means for performing time keeping, a storage means for storing a predetermined warming temperature, and a control means for controlling each of the above means and performing various operations including water heating and warming, without water heating after power-on. When the heat retaining operation is started, energization of the heating means is controlled so as to maintain the temperature of the hot water at a predetermined heat retaining temperature set in advance, and the heat retaining operation is performed. The heat retaining temperature is switched in accordance with the operation amount of energization or disconnection of the heating means, and the heat retaining operation is performed by controlling the power supply to the heating means so as to maintain the temperature of the hot water at the switched thermal insulation temperature. Features And electric pot.