JP2003235732A - Electric kettle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric kettle which detects the existence of liquid in its container early even when it is not under the water-heating operation. <P>SOLUTION: This electric kettle has a container 1 to contain a liquid and a heating means 2 to heat and hold the temperature of the liquid in the container. The heating means is repeatedly operated for a short period of time with a predetermined interval until the detected temperature in the container reaches at least a first temperature predetermined at a temperature not less than the boiling point. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric water heater for heating and retaining the temperature of a liquid contained in a container, and more particularly to water supply detection.

[0002]

2. Description of the Related Art Heretofore, as this kind of electric water heater, the one described in JP-A-6-121739 is known. FIG. 8 shows the structure of a conventional electric water heater, which includes a temperature detecting means 3 for detecting the temperature of the liquid in the container 1,
The heating means 2 for heating the liquid in the container, the heating start means 5 for operating the boiling detection means 4 when the temperature detection means 3 detects a temperature lower than a predetermined temperature, and the heating means 3 for the operation of the boiling detection means 4 When the heating is started, the heating means 3 is turned on and off in a predetermined manner when the heating is started, and the temperature rise rate of the liquid is small during a fixed time from the start of the heating. Only at this time, the temperature rise determination means 18 for reactivating the heating means 3 is used.

However, in the conventional structure as described above, even though the hot water in the container 1 is exhausted, the structure of the temperature rise determining means 18 causes the emptying of the container 1 unless the boiling of water is started. I could not detect that. Furthermore, even if boiling water is started, since it is judged by the rate of temperature rise of the liquid during a fixed time from the start of heating, it cannot be detected immediately, but can be detected only after boiling water for a fixed time. Of. Therefore, there is a problem in that the user cannot reheat the container to immediately let the user know that the inside of the container is empty.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides an electric water heater which has a simple structure and can notify that the inside of the container is empty before starting the water heating while keeping warm or after the hot water operation. The purpose is to

[0005]

To achieve the above object, the present invention provides a container for containing a liquid, a heating means for heating and retaining the liquid in the container, and a temperature in the container equal to or higher than a first predetermined temperature. The heating means is operated for a short period of time until it is detected.

As a result, when the liquid in the container is exhausted,
By operating the heating means for a short time, the temperature inside the container can be raised to a temperature higher than the boiling point even during boiling, and it is possible to easily detect that the inside of the container is empty.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is a container for containing a liquid, a heating means for heating and retaining the liquid in the container, and a temperature in the container is equal to or higher than a first predetermined temperature. By configuring the heating means to operate for a short time until detection, when the liquid in the container is exhausted, the temperature inside the container can be raised to a temperature higher than the boiling point, and the inside of the container can be heated before boiling. It can be easily detected that is empty.

According to the second aspect of the present invention, the heating means is operated for a short period of time every first predetermined time, so that the short-time operation is performed at regular intervals, so that the water heating operation is performed. It is possible to easily detect that the inside of the container is empty without ejecting steam at times other than the above.

According to the third aspect of the present invention, the heating means is operated for a short time until the temperature difference before and after the heating means is operated for a short time becomes a predetermined value or more, so that the predetermined temperature is not reached. By detecting a rapid temperature rise, it is possible to more quickly detect that the container is empty.

According to the fourth aspect of the present invention, when the temperature is equal to or higher than the predetermined temperature or the temperature difference is equal to or higher than the predetermined value, the notification is made, so that the user is promptly notified that the container is empty. be able to.

According to the fifth aspect of the invention, the short-time operation of the heating means is limited to the heat-retaining operation.
Since it is possible to restrict the heating operation only during the operation using hot water, it is possible to reduce wasteful heating operation and to easily reliably detect that the container is empty.

According to the sixth aspect of the invention, the heating means is operated for a short time during the heat retention operation and the standby operation (timer operation, etc.). Since it can be limited to standby operation such as boiling water after time, wasteful heating operation can be reduced and
It is possible to easily detect that the inside of the container is empty.

According to a seventh aspect of the present invention, the number of times the heating means is operated for a short time is set to a predetermined number of times, and the number of times required for the residual water remaining after all the hot water in the container is dried is required. By restricting the operation for a short time only, after detecting the presence of the liquid in the container, it is possible to detect the efficient waterless detection without unnecessary heating with a simple configuration.

According to the eighth aspect of the present invention, when the hot water discharge operation is performed, the short-time operation of the heating means is restarted. Since the heating means is operated only when the amount of hot water decreases, It is possible to easily detect that the inside of the container is empty while reducing unnecessary heating.

According to the ninth aspect of the invention, when it is detected that the amount of water is in the boiling water, the operation of the heating means is stopped for a short time. When the liquid is present, the heating is not performed for a short time, so that it is possible to easily detect that the liquid in the container is empty while reducing unnecessary heating.

According to a tenth aspect of the present invention, when it is detected that there is water in the boiling water, the heating means is stopped for a short time until a hot water discharge operation is performed. When the liquid is surely present in the container at this point of time, heating is not performed for a short time until the amount of the liquid is reduced. Therefore, it is possible to easily detect that the liquid in the container is empty while reducing unnecessary heating.

[0017]

Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIG. 1 is a block diagram of an electric water heater showing Embodiment 1 of the present invention. Reference numeral 1 is a container for containing a liquid such as water, and 2 is a heating means such as an electric heater.
Similar to (shown in FIG. 2), it is constituted by a second heating element 2b (shown in FIG. 2) that has a smaller heating power than the first heating element 2a that heats / heats the liquid in the container 1.

Reference numeral 3 denotes a temperature detecting means for contacting the container 1 to detect the temperature of the liquid in the container, 4 is a boiling detecting means, 5 is a heating starting means, 6 is an energizing means, and 7 is an empty cooking detecting means.
The heating starter 5 inputs a signal when the temperature detector 3 detects a temperature lower than the second predetermined temperature (about 90 ° C. in the present embodiment), and reheater forcibly starting heating (described later). Is input to operate the boiling detection means 4 and the empty cooking detection means 7. Also,
The boiling detecting means 4 is configured to operate the heating means 2 by controlling the energizing means 6 until the boiling of the liquid in the container 1 is detected from the temperature detected by the temperature detecting means 3. When the boiling detection means 4 starts boiling water, the boiling detection means 7 detects the presence or absence of the liquid in the container from the temperature rise gradient of the liquid in the container 1 and, if there is no liquid, the heating means 2 Stop the heating operation of.

Reference numeral 8 is a hot water discharge operation means, 9 is a hot water discharge means, and 10 is a control means. Then, the control means 10 turns on the lock release switch 8b (shown in FIG. 2) constituting the hot water operation means 8 to make the hot water means 9 ready for hot water. Further, when the hot water outlet switch 8a (shown in FIG. 2) constituting the hot water outlet operating means 8 is turned on in the hot water dischargeable state, the hot water outlet means 9 can be driven while it is on. The hot water outlet means 9 is composed of a casing 9a into which liquid is fed from the bottom of the container 1 and is fed out by rotation of an impeller, a motor 9b for rotating the impeller, and a water conduit 9c for leading the liquid fed out from the casing to the outside of the body. And discharges the liquid in the container 1 to the outside.

Reference numeral 11 is a notification means for notifying the operating state of the electric water heater to the outside by sound, light, etc., 12 is an operation control means, 13 is a temperature determination means, and 14 is a standby means. The operation control means 12 determines the operation mode of the electric water heater. Whether the electric water is being heated by an input based on the temperature detected by the temperature detecting means 3 (the water heating mode) or the temperature being maintained (the temperature maintaining mode). )
Alternatively, whether it is in a standby state (timer mode) input from the standby means 14, or whether there is a hot water discharge operation by the driving of the hot water operation means 8, or the liquid is stored in the container while the water is being boiled by the empty cooking detection means 7. Whether or not the heating means 2 is to be operated for a short time is determined based on conditions such as after confirming that the heating means 2 exists.

The temperature determination means 13 is the operation control means 1 described above.
If the condition for short-time operation is satisfied by inputting 2,
The heating of the heating means 2 is operated for a short time. This short-time operation time is set so that the temperature can be raised to the first predetermined temperature when the container is empty, and the temperature is not raised to a temperature at which the container 1 may be discolored. A predetermined time of 5 (5 seconds in this embodiment). The temperature difference before and after the heating means 2 is operating for a short time is set to a predetermined value (about 3 ° C. in this embodiment) or higher than the boiling temperature. When it is determined whether or not the temperature exceeds a predetermined temperature (120 ° C. in the present embodiment) and the temperature difference is detected to be a predetermined value or more or the first predetermined temperature or more, the heating means 2 including the short-time operation is also included. The heating operation is prohibited and the notification means 11 is caused to display that there is no liquid in the container.

The standby means 14 keeps the operation of the heating means 2 stopped for a required time when hot water is not used for a long time. When the set time is reached, the heating means 2 is operated to bring it to a boil. Alternatively, there are those that perform a heat retention operation depending on the temperature when the set time is reached.

FIG. 2 is an electric circuit diagram of the electric water heater according to the first embodiment of the present invention. 15 is stored in FIG.
According to the flow shown in FIG. 3, the boiling detection means 4, the empty cooking detection means 7, the control means 10, the operation control means 1
2. A microcomputer (hereinafter referred to as a microcomputer) that controls the temperature determination means 13 and performs comparison determination,
The boiling detection unit 4, the boiling cooking detection unit 7, the control unit 10, the operation control unit 12, the temperature determination unit 13, and a plurality of counters serving as a clocking unit (not shown) are configured. Reference numeral 16 is a commercial power source, and 17 is a direct current power source, which is generated from the commercial power source 16 via a rectifier circuit or a regulator, and the voltage does not immediately drop even if the power source is turned off. For a predetermined time (a few seconds in the present embodiment), the microcomputer 15 is configured to have a power storage capacity capable of being driven so that the microcomputer 12 can perform the process at the time of the power failure even when the power failure is detected. .

The heating means 2 includes a first heating element 2a for heating the liquid in the container 1 and a second heating element for heating and keeping the liquid in the container with a smaller heating power than that of the first heating element 2a. Two
b, which is controlled by the energizing means 6. The energizing means 6 includes relay contacts 6a and 6b connected in series with the commercial power source 16, and the relay contacts 6a and 6b.
It is composed of relay coils 6c and 6d for controlling b,
These relay coils are ports a and b of the microcomputer 15.
A current is caused to flow by controlling the above, and the relay contact is closed.

The temperature detecting means 3 forms a divided voltage value with the temperature sensitive element 3a for converting the temperature into a resistance value and the temperature sensitive element 3a and the resistor 3b, and inputs the divided voltage value to convert it into a binary code. It is composed of an AD converter 3c. The AD converter 3c sets a temperature range of about 30 ° C. to 120 ° C. to a predetermined unit temperature width (about 0.5 ° C. in this embodiment) and outputs a signal to the microcomputer 15 every time the unit temperature width rises. To do.

The microcomputer 15 detects the boiling start temperature (about 80 ° C. in the present embodiment) or more if the water is being heated based on the signal input from the temperature detecting means 3 every time the unit temperature width rises. Then, the time for increasing the unit temperature width is repeatedly measured, and it is considered that the temperature increase gradient of the liquid has disappeared by measuring the time for a third predetermined time (about 20 seconds in this embodiment) or more. When boiling is detected, it is determined that there is no liquid in the container 1 if it is less than the fourth predetermined time (1 second in this embodiment) during boiling, and the empty cooking is detected, and the heating means 2 is stopped. Let

On the other hand, the operation of the microcomputer 15 while keeping the temperature is the second predetermined temperature 90.degree. C. or the third predetermined temperature (about 95.degree. C. in this embodiment) depending on the temperature detected by the temperature detecting means 3. It is determined whether each is higher or lower, and when the temperature is lower than the second predetermined temperature, the heating means 2 is operated to boil water, and at the time of heat retention, the second predetermined temperature and the third predetermined temperature are When in the interval, the second heating element 2b is operated to maintain the heat retention temperature. Further, the microcomputer 15 detects that the detection signal of the first predetermined temperature of 120 ° C. or more and the temperature difference between before and after the short-time operation of the heating means 2 during the short-time operation is a predetermined value or more. The heating means 2 is configured to turn off the energization (operation).

The reheating means for forming a part of the heating starting means 5 to forcibly reheat the liquid under heat retention is composed of a reheating switch 5a and resistors 5b, 5c, and the output of the reheating switch is set by the microcomputer 15. The boiling detection means 4 is driven by the detection. Further, the reheating means may be configured to add an operation of continuing the boiling state in order to remove the odor of chlorine after removing the boiling when the reheating switch 5a is turned on again during the heating operation of the heating means 2.

The hot water discharge operation means 8 is composed of a hot water discharge switch 8a for starting the hot water discharge operation and a lock release switch 8b for releasing the hot water discharge switch 8a to accept the operation as valid. The motor driving unit of the tapping means 9 includes the tapping switch 8a, the transistor 9d, and the transistor 9d which are connected in series with the motor 9b.
And a hot water outlet unit for inputting a signal for determining whether or not to turn on the transistor 9d to the port c of the microcomputer 15 to control the above.

When the lock release switch 8b is turned on, the microcomputer 15 causes the hot water discharge switch 8a at that time.
The on / off state of is detected. This is the hot water switch 8
Since the electric potential between a and the motor 9b is connected to the port c of the microcomputer 15, if the input electric potential is "H", the hot water outlet switch 8a is in the on state, so the transistor 9d is turned on. Then, there is a fear that the hot water will immediately come out, and for safety, the input of the lock release switch 8b is invalidated.

When the input potential is "L", since the hot water discharge switch 8a is off, there is no possibility of immediate hot water discharge, and therefore the transistor 9d is turned on (in this embodiment, this state is used). Called hot water waiting state). When the hot water discharge switch 8a is turned on in this state, hot water is discharged (this state is called a hot water discharge state in this embodiment). If the hot water discharge switch 8a is not turned on after a predetermined release time (10 seconds in the present embodiment) has elapsed from the end of hot water discharge, the hot water discharge is finished and the transistor 9d is turned off again (automatic OFF operation). The standby state is released (this state is referred to as the hot water discharge prohibition state in this embodiment). When the hot water discharge prohibition state is reached, the hot water cannot be discharged only by turning on the hot water discharge switch 8a.

If the hot water outlet switch 8a is in the ON state when the hot water is not ready, the state is detected and the lock release switch 8b is activated during that time.
It is also configured to disable the input of. Reference numeral 11 is an informing means, which notifies the end of boiling or reception of each switch input by the buzzer 11a, and the LEDs 11b and 11c.
Is used to display information such as during boiling water, keeping warm, or detecting empty cooking, and using the LCD or 7-segment LED to display the current temperature and the like.

Reference numeral 14 is a standby means, which is composed of a timer switch 14a for making a timer input and resistors 14b and 14c. By inputting the input of the timer switch 14a to the microcomputer 15, the microcomputer 15 causes the heating means 2 to operate. The energization is turned off, and the heating means 2 is turned off to stand by for the time set by the switch. The setting of the set time is arbitrary. By executing the program, the microcomputer 15 realizes the control between each means as described above.

In the above embodiment, the operation of the invention of the first embodiment will be described based on FIG. 3 which is a flow chart of the temperature control and hot water discharge control portion of the program stored in the microcomputer 15. FIG. 3 shows the basic operation of the electric water heater when the power is turned on. First, when the electric water heater is turned on, data in all microcomputers including a counter for counting the first predetermined time (10 minutes in this embodiment) in step (hereinafter referred to as S) 1 Is initialized and whether the temperature is equal to or higher than the second predetermined temperature or lower than the second predetermined temperature is determined from the temperature detected by the temperature detecting means 3 (S2). Generally, the temperature is lower than the second predetermined temperature because water is put into the container 1 and starts boiling. However, when the power is turned on at the second predetermined temperature or higher, the temperature is kept after S17 described below. The control shifts to.

If the temperature is lower than the second predetermined temperature in S2, S
In 3 set the notification means 11 to display when boiling water,
The heating means 2 (in this embodiment, only the first heating element 2a) is operated to start boiling water. At the beginning of the water heating, the heating means 2 is turned on and off as shown in the conventional example (in this embodiment, 10 seconds on and 10 seconds off).
Then, by detecting the idle cooking from the degree of temperature rise in a fixed time from the start of the on / off operation, it is possible to reliably detect the idle cooking during boiling water.

Next, in S4, the counter for counting the first predetermined time is timed, and in S5, whether or not to carry out the boiling extension maintaining operation to further increase the removal rate of the bleaching odor after the boiling is detected is determined. It is determined whether or not the selected descaling setting has been made, and if it is turned on, the descaling flag is set in S6. After that, the time for increasing the unit temperature width based on the detection signal of the temperature detecting means 3 is repeatedly measured, and from the unit temperature rising time, the temperature rising degree is detected and the boiling detection is started from the boiling start temperature or higher. The determination is repeated (S7, S9).

Furthermore, it is also determined whether or not the temperature has risen above the first predetermined temperature (S8). Here, when a sudden rise in temperature or a temperature equal to or higher than the first predetermined temperature is detected, the process proceeds to S27, the operation of the heating means 2 is stopped, and the display during the idle cooking operation is performed. When boiling is detected in S9, the process proceeds to S10, where it is determined whether or not the Kalki flag is set. If not set, the process from S16 onward is completed and control is continued during heat retention. On the other hand, if the Kalki flag is set, the counter for measuring the extension time is cleared to clear the Kalky flag (S1).
1).

Next, both the counters are timed,
The operation of the heating means 2 is continued until a predetermined extension time (3 minutes in this embodiment) has elapsed (S12 to S15). In the meantime, the time for the unit temperature width to rise is repeatedly measured, and it is also determined whether or not the temperature suddenly rises or whether the temperature rises above the first predetermined temperature. Here, when the temperature suddenly rises or the first predetermined temperature or more is detected, the process proceeds to S27,
The operation of the heating means 2 is stopped and the display during the empty cooking operation is performed. When the predetermined extension time has elapsed in S15, the water heating is terminated and the control proceeds to S16 and thereafter.

In S16, the buzzer 1 of the notification means 11
The end of boiling is notified by 1a. After that, the operation of the heating means 2 is stopped, and the display of the LEDs 11b, 11c and the like is changed to the display indicating that the temperature is maintained (S17). Next, in S18, the counter for counting the first predetermined time is continuously clocked, and in S19, whether the temperature is equal to or higher than the second predetermined temperature or lower than the second predetermined temperature is determined from the temperature detected by the temperature detecting means 3. to decide. Here, the temperature lower than the second predetermined temperature is when the temperature is lowered due to addition of water or the like, and the process returns to S3 again to perform the boiling water operation.

Furthermore, when the reheating switch 5a is turned on, which is performed when it is desired to forcibly heat water during the heat retention operation, the process similarly returns to S3. If the reheat switch 5a is not input in S20, it is determined in S21 whether the temperature is higher or lower than the third predetermined temperature. When the temperature is low, the second heating element 2b is turned on, and when it is high, the second heating element 2b is turned off. Thus, the heating means 2 is operated, and it is determined in S22 whether or not the temperature is equal to or higher than the first predetermined temperature. Here, when the temperature equal to or higher than the first predetermined temperature is detected, the process proceeds to S27, the operation of the heating means 2 is stopped, and the display during the idle cooking operation is performed.

Next, in S23, it is judged whether or not the time measured by the counter has counted the first predetermined time or longer, and if the time is measured, the heating means 2 is operated for the fifth predetermined time. (S24). Then, after the lapse of the fifth predetermined time, the heating means 2 is turned off, and further, the counter for measuring the fifth predetermined time is cleared (S25), and the temperature rises within the fifth predetermined time. If the degree is higher than the predetermined value, the process proceeds to S27, the operation of the heating means 2 is stopped, and the display during the empty cooking operation is performed. On the other hand, when the temperature difference is smaller than the predetermined value, S1
Returning to 7, the heat retention operation is continued.

Next, the empty cooking detection process after S27 will be described. When the mode shifts to the empty cooking mode in S27 or S8, the buzzer 11a is notified in S27. At the same time, in S28, the operation of the heating means 2 is turned off, and in S29, the LED is used to notify that the container is empty. Then, the processing from S27 is repeated until the input of the reheating switch 5a is detected,
When a is input, the counter is cleared in S31 and then the process returns to S3 to restart the boiling water operation.

As described above, in this embodiment, the heating means heats every first predetermined time for the fifth predetermined time during the heat retention operation, thereby promptly detecting the absence of the liquid in the container other than the boiling water operation. , It can be realized with a simple configuration.

In this embodiment, the boiling is controlled only by the first heating element 2a, but the second heating element 2b is controlled.
It is also possible to use a combination of the above and boiling water. Also, the first
If the predetermined time is increased, useless electric power can be reduced, but on the other hand, the detection of the empty space in the container becomes slower. Further, the fifth predetermined time is also set to 5 seconds in this embodiment, but this time is set to the heating capacity of the heating means 2 and the first time.
It is easy to change the set value depending on the setting of the predetermined temperature.

(Embodiment 2) FIG. 4 is a flow chart showing the operation of the electric water heater in the second embodiment of the present invention at the time of boiling water, and FIG. 5 is a flow chart showing the operation of the electric water heater in keeping warm. In this example, when boiling water,
Since the flow of the operation at the time of keeping heat is only different from that of the first embodiment of the invention, detailed description of the same parts will be omitted by using FIGS. 1 and 2, and different parts will be mainly described.

The microcomputer 15 stores the boiling detection means 4, the empty cooking detection means 7, the control means 10, and the operation control means 1 according to the stored flow shown in FIGS. 4 and 5.
2. The temperature determination means 13 is controlled and the comparison determination is performed.

In FIG. 4, the basic operation of the electric water heater after the power is turned on, particularly the operation in the water heater mode is shown. As in the first embodiment, when the electric water heater is first turned on, All the data inside the microcomputer including the counter for counting the first predetermined time is initialized (S41), and whether the temperature is equal to or higher than the second predetermined temperature or lower than the second predetermined temperature is detected by the temperature detecting means 3. It is determined more (S42).

If the temperature is lower than the second predetermined temperature in S42, the notification means 11 is set to the display for boiling water in S43, and the heating means 2 is operated to start boiling water. When the boiling water is started, the energization of the heating means 2 is turned on / off to detect the empty cooking from the degree of temperature rise in a certain time from the start of the on / off operation, thereby reliably detecting the empty cooking in the boiling water. There is.

Next, it is determined whether or not there is an input from the timer switch 14a, which is the standby means 14 for shifting to the timer mode, and if there is an input, the control shifts to the timer mode control described later (S44). And S45
After the boiling is detected, it is determined whether the descaling setting for selecting whether to perform the boiling extension maintaining operation performed to further increase the removal rate of the bleaching smell is performed. If it is turned on, the calking flag is set in S46. Set it. After that, the signal from the temperature detecting means 3 is taken in, and the time for increasing the unit temperature width is repeatedly measured. In each case, from the unit temperature rising time, the temperature rising degree and from the boiling start temperature or higher, the boiling is started. The detection determination is repeated (S47, S48).

If the temperature suddenly rises and it is determined that the cooking will be performed in the air, the control shifts to the control in the cooking mode which will be described later. When boiling is detected in S48, the process proceeds to S49, where it is determined whether the bleaching flag is set or not. If not set, the process proceeds from the end of boiling after S55 to the control in the heat retention mode. On the other hand, if the Kalki flag is set, the counter for measuring the predetermined extension time is cleared to clear the Kalki flag (S50).

Next, the counter is clocked, and the operation of the heating means 2 is continued until the predetermined extension time has elapsed (S51 to S54). During that time, the time for which the unit temperature width rises is repeatedly measured, and the degree of temperature rise is determined each time, and when it is determined that the cooking is empty, the mode shifts to the cooking mode described later. Further, it is determined whether or not there is an input from the timer switch 14a for starting the standby operation, and if there is an input, the control shifts to a timer mode control described later.

When the predetermined extension time elapses in S54, the water heating is ended and the control proceeds to S55 and thereafter.
In S55, the buzzer 11a of the notifying means 11 notifies the end of boiling. After that, the heating operation of the heating means 2 is stopped, and the display of the LEDs 11b, 11c and the like is changed to the display during heat retention (S57). After that, it is configured to shift to the control in the heat retention mode described later.

FIG. 5 shows the operation of the electric water heater in the heat retaining mode, the timer mode and the idle cooking mode. When the heat retaining mode is shifted to S42 or S56 as shown in FIG. In S61, a counter for counting the number of operations (five times in this embodiment) for operating the heating means 2 for a short period of time for the fifth predetermined time is cleared, and a counter for counting the first predetermined time is initialized. Set the value.

This initial value is set differently depending on whether or not the short-time operation is performed immediately after boiling. For example, when the heating means 2 is configured to perform the short-time operation immediately after the end of boiling, the initial value is set to the first value. If a predetermined time of 1 is set, or if the short-time operation is to be performed after the first predetermined time even immediately after the end of heating, the counter is cleared, etc. It can be carried out. In the present embodiment, the first predetermined time is set to perform the former operation.

Next, in S62, the heat retention operation mode is set. That is, the display by the notification means 11 indicating that the temperature is being kept is performed. Next, it is determined whether or not there is an input from the timer switch 14a, which is the standby means 14 for starting the standby operation, and if there is an input, control is passed to a timer mode control described later (S63). Furthermore, S6
Even when the reheating switch 5a is turned on, which is performed when it is desired to forcibly heat the water during the heat retention operation in step 4, the process shifts to the water heating mode from S43 in FIG.

If the reheat switch 5a is not input in S64, it is determined in S65 whether the temperature is equal to or higher than the second predetermined temperature or lower than the second predetermined temperature based on the temperature detected by the temperature detecting means 3. Here, when the temperature falls below the second predetermined temperature due to addition of water or the like, when the temperature is low, the mode shifts to the water heating mode from S43 of FIG. Next, in S66, it is determined whether the temperature is higher or lower than the third predetermined temperature, and when the temperature is lower than the third predetermined temperature, the second heating element 2b is turned on (energized) to maintain the heat retention temperature.

Next, in S67 to S71, the counter for counting the first predetermined time is clocked, and it is judged whether or not the time counted by the counter is clocked for the first predetermined time or longer, and the time is measured. If so, the heating means 2 is operated only for the fifth predetermined time which is a short time. Then, when the operation of the heating means 2 is completed, the counter is cleared, and if the degree of temperature increase during the fifth predetermined time is larger than the predetermined value, the mode shifts to an empty cooking mode described later.

On the other hand, when the degree of temperature rise is smaller than the predetermined value, it is determined in S72 whether the temperature is equal to or higher than the first predetermined temperature. Here, when the temperature equal to or higher than the first predetermined temperature is detected, the processing of the air cooking mode described later is performed. In S72, the
When the temperature is below the predetermined temperature of 1, it is determined in S73 whether the current mode is heat retention. If it is heat retention, the process returns to S62 and control of the heat retention mode is continued.

Next, the operation in the timer mode will be described. When the timer mode is entered in S44 or S52 in FIG. 4, first, in S74, the counter for counting the number of times of the operation for causing the heating means 2 to operate the short time operation is cleared in the same manner as in the heat retention mode described above. The first predetermined time is set as an initial value in a counter that counts the first predetermined time. Further, the timer counter for counting the waiting time set by the timer switch 14a of the waiting means 14 is also cleared at the same time.

Next, it is judged whether or not the timer switch 14a is turned on, and if it is turned on, it is considered that the timer mode has been released, and the heat retaining operation of S62 is started. Further, even when the timer counter detects that the waiting time has elapsed, the process similarly proceeds to S62 (S75, S
76). In this embodiment, only one waiting time is set (for example, 6 hours), but a plurality of waiting times can be set easily. At this time, the set value may be changed each time the timer switch 14a is turned on, and finally the timer mode may be set to be released.

Next, in S77, the operation setting of the timer mode is performed. That is, the notification means 11 indicating that the timer is in progress
Is to be displayed. Then, in S78, the time of the timer counter is measured, and even in the case where the reheating switch 5a is turned on, which is performed when it is desired to forcibly heat the water during the timer operation in S79, the water heating mode from S43 in FIG. 4 is set. Transition. After that, the operations in S67 to S73 described above are performed, and the operation in the timer mode is realized by returning to S75.

Next, the empty cooking detection process after S80 will be described. S47 and S53 in FIG. 4 and S7 in FIG.
If the mode is changed to the empty cooking mode by 1 and S72, S
At 80, the buzzer 11a is first notified. And
At the same time, in S81, an LED is used to notify that the container 1 is empty, and in S82, the heating operation of the heating means 2 is turned off (stopped). Then, the reheating switch 5a
The process from S81 is repeated until the input of is detected, and when the reheat switch 5a is input, the above S43 of FIG. 4 is performed.
Return to and restart the kettle operation.

As described above, in the present embodiment, the heating means is operated for a short time only in a mode in which the hot water is easily discharged, such as the warming operation and the timer operation accompanying it, so that the water in the container can be promptly removed. It is possible to notify the user, and it is possible to easily carry out control while suppressing unnecessary heating as much as possible.

(Embodiment 3) FIG. 6 shows a heat retention mode, a timer mode, and an electric water heater in Embodiment 3 of the present invention.
It is a flowchart which shows the operation | movement in empty cooking mode. Since the operation flow of this embodiment is different from the inventions of the first and second embodiments, detailed description of the same parts will be omitted by using FIGS. 1, 2, and 4, and different parts will be mainly described. explain.

The microcomputer 15 stores the control of the boiling detection means 4, the boiling detection means 7, the control means 10, the operation control means 12, the temperature determination means 13 according to the stored flow shown in FIG. This is to make a comparison judgment.

In the figure, the operation in the heat retention mode will be described first. The basic operation from the time of power-on of FIG. 4 is particularly linked to the operation of the water heating mode, and when the heat retention mode is shifted by S42 or S56 shown in FIG.
First, in S91, the counter for counting the number of times of the short-time operation of the heating means 2 is cleared, and the counter for counting the first predetermined time is set with the first predetermined time as an initial value.

Next, in S92, the heat retention operation mode is set. That is, the display by the notification means 11 indicating that the temperature is being kept is performed. Next, it is determined whether or not the timer switch 14a, which is the standby means 14 for starting the standby operation, has been input, and if there is an input, the control shifts to the timer mode control described later (S93). Moreover,
Also in S94, when the reheating switch 5a, which is the heating start means 5 performed when it is desired to forcibly heat the water during the heat retention operation, is turned on, the mode shifts to the water heating mode from S43 in FIG. If there is no input from the reheat switch 5a in S94, it is determined in S95 whether the temperature is equal to or higher than the second predetermined temperature or lower than the second predetermined temperature based on the temperature detected by the temperature detecting means 3. Here, when the temperature is lower than the second predetermined temperature due to addition of water or the like, when the temperature is low, S in FIG.
It shifts to the water heating mode from 43.

Next, in S96, it is determined whether the temperature is higher or lower than the third predetermined temperature, and when the temperature is lower than the third predetermined temperature, the second heating element 2b is energized to control the temperature to be maintained.
Next, in S97, it is determined whether or not the counter has counted the number of operations, and if it has counted, the process proceeds to S104 described later.

On the other hand, if the counter has not yet counted the number of operations in S97, the counter for measuring the first predetermined time is timed in S98 to S103, and the time measured by the counter is the first predetermined time. It is judged whether or not the above time is measured, and if the time is measured, the heating means 2 is energized for the fifth predetermined time which is a short time operation. Then, when the operation of the heating means 2 is completed, the counter is cleared and the value of the counter for counting the number of operations is added. Further, when the degree of temperature rise during the fifth predetermined time is larger than the predetermined value, the mode shifts to an idle cooking mode described later.

On the other hand, when it is smaller than the predetermined value, S1
At 04, it is determined whether the temperature is equal to or higher than the first predetermined temperature.
Here, when the temperature equal to or higher than the first predetermined temperature is detected, the process of the air cooking mode described later is performed. When the temperature is lower than the first predetermined temperature in S104, the process proceeds to S105, it is determined whether the current mode is heat retention, and if it is heat retention, S10 is performed.
At 6, confirm whether or not there is a tapping operation. And
If the tapping operation has been confirmed, the operation in the heat retention mode is continued from S91, and if there is no tapping operation, the operation in the heat retention mode is continued from S92.

Next, the operation in the timer mode will be described. When the timer mode is entered in S44 or S52 in FIG. 4, first, in S111, the counter for counting the number of operations for performing the short-time operation of the heating means 2 is cleared in the same manner as in the heat retention mode, and the first operation is performed. The first predetermined time is set as an initial value in a counter that counts the predetermined time. Further, the timer counter for counting the waiting time set by the timer switch 14a of the waiting means 14 is also cleared at the same time.

Next, in S112, the timer switch 1
It is determined whether or not 4a is turned on, and if it is turned on, it is regarded as the reset setting of the timer mode, and the process proceeds to the heat retention operation of S92. Further, even if the timer counter detects that the waiting time has elapsed in S113, the same operation is performed in S92.
Move to.

Next, in S114, the operation setting of the timer mode is performed. That is, the display of the notification means 11 indicating that the timer is in progress is performed. Then, in S115,
Even when the reheat switch 5a of the heating starting means 5 is turned on, which is performed when the timer counts the time and the user wants to forcibly heat the water during the timer operation in S116, the water heating mode from S43 in FIG. 4 is set. Transition.

Next, if the hot water discharge operation is confirmed in S117, the counter for counting the number of operations for operating the short-time operation of the heating means 2 is cleared in S118,
A counter for counting the first predetermined time is set with the first predetermined time as an initial value. After that, the above S
The operation of the timer mode is realized by performing the operation of S105 from 97 and returning to S112.

Next, the empty cooking detection process after S121 will be described. S47 and S53 in FIG. 4, and S1 in FIG.
If the mode is switched to the empty cooking mode by 03, S104,
In step S121, the buzzer 11a is first notified. At the same time, in S122, an LED is used to notify that the container 1 is empty, and in S123, the heating means 2 is de-energized. Then, the process from S122 is repeated until the input of the reheating switch 5a is detected, and when the reheating switch 5a is input, the process returns to S43 of FIG. 4 described above to restart the boiling water operation.

As described above, in the present embodiment, the heating means is operated only for a mode in which hot water is easily discharged, such as a heat retention operation and a timer operation associated with it, and the heating means is operated for a short time, and after that, hot water is discharged. By restarting every time there is an operation, it is possible to promptly notify that there is no water in the container, and it is possible to easily perform control while suppressing wasteful heating as much as possible.

(Fourth Embodiment) FIG. 7 is a flow chart showing the operation of the electric water heater in the fourth embodiment of the present invention at the time of boiling water. In this embodiment, the operation flow is the first embodiment.
Since it is different from the invention of the third embodiment, detailed description of the same parts will be omitted using FIGS. 1, 2, and 6, and different parts will be mainly described.

The microcomputer 15 stores the control of the boiling detection means 4, the empty cooking detection means 7, the control means 10, the operation control means 12, the temperature determination means 13 in accordance with the stored flow shown in FIG. This is to make a comparison judgment.

FIG. 7 shows the basic operation of the electric water heater when the power is turned on, particularly in the water heater mode, which is interlocked with the operations in the heat retention mode, the timer mode and the empty cooking mode in FIG. Similarly to the second embodiment, when the electric water heater is first powered on, S13
In step S13, data in all the microcomputers including the counter for counting the first predetermined time is initialized,
In 2, it is determined from the temperature detected by the temperature detecting means 3 whether the temperature is equal to or higher than the second predetermined temperature or lower than the second predetermined temperature.

If the temperature is lower than the second predetermined temperature in S132, the notification means 11 is set to the display for boiling water in S133, and the heating means 2 is operated to start boiling water. When boiling water is started, the heating means 2 is turned on and off to detect idle cooking from the degree of temperature rise within a certain time from the start of the on / off operation, thereby reliably detecting idle cooking during boiling water.

Next, in S134, it is determined whether or not the timer switch 14a of the standby means 14 for shifting to the timer mode has been input, and if there is an input, the control shifts to the timer mode control of FIG. Next, S13
In step 5, it is determined whether or not the descaling setting for selecting whether or not to perform the boiling extension maintaining operation performed to further increase the removal rate of the bleaching smell after the boiling is detected is determined. Set.

After that, the time for increasing the unit temperature width is repeatedly measured based on the temperature detecting means 3, and in each case, from the unit temperature width increasing time, the degree of temperature increase, and from the boiling start temperature or higher, the boiling is started. The detection determination is repeated (S137, S138). Here, if the temperature suddenly rises and it is determined that the cooking will be performed in the idle mode, the control shifts to the above-described idle cooking mode in FIG.

When boiling is detected in S138, the flow proceeds to S139 to determine whether or not the bleaching flag is set. If not set, the control is continued from the end of boiling after S145 to the heat retention control. On the other hand, if the Kalki flag is set in S140, the counter for measuring the predetermined extension time is cleared to clear the Kalki flag.

Next, the counters are timed in S141 to S144, and the operation of the heating means 2 is continued until the predetermined extension time elapses. In the meantime, the time for increasing the unit temperature width is measured repeatedly, and the degree of temperature increase is determined each time, and when it is determined that the cooking is empty, the above-described cooking mode of FIG. 6 is performed. Further, it is determined whether or not there is an input of the timer switch 14a for starting the standby operation, and if there is an input, the process shifts to the control of the timer mode of FIG. 6 described above. When the predetermined extension time has elapsed in S144, the water heating is terminated and the control proceeds to S145 and thereafter.

In S145, the buzzer 11a of the notifying means 11 notifies the end of boiling. After that, the operation of the heating means 2 is stopped, and the display of the LEDs 11b and 11c is changed to the display during the heat retention (S146). Then, in step S147, the number of operations is set in the counter, and the control is shifted to the control in the heat retention mode of FIG. 6 described above. By doing so, the number of operations of the heating means 2 can be set as the initial value of the counter, and the short-time operation of the heating means 2 is not considered to be completed when the heat retention mode is shifted to immediately after boiling. can do.

As described above, in this embodiment, since it is clear that the liquid is in the container immediately after the boiling of water is completed, the short-time operation is not performed by the heating means unless the hot water is discharged. It is possible to surely realize waterless detection with a simple configuration other than the boiling water operation while suppressing wasteful heating as much as possible.

[0088]

INDUSTRIAL APPLICABILITY As described above, the present invention can realize an excellent electric water heater capable of reliably and promptly detecting the presence or absence of the liquid in the container even during the water heating operation.

[Brief description of drawings]

FIG. 1 is a block diagram of an electric water heater according to a first embodiment of the present invention.

FIG. 2 is an electric circuit diagram of the electric water heater according to the first embodiment.

FIG. 3 is a flowchart showing the operation of the electric water heater according to the first embodiment when the power is turned on.

FIG. 4 is a flow chart showing the operation of the electric water heater in the second embodiment of the present invention at the time of water heating.

FIG. 5 is a flow chart showing the operation of the electric water heater in the second embodiment such as during heat retention.

FIG. 6 is a flow chart showing the operation of the electric water heater in the third embodiment of the present invention when the temperature is kept warm.

FIG. 7 is a flow chart showing the operation of the electric water heater in the fourth embodiment of the present invention at the time of water heating.

FIG. 8 is a block diagram of a conventional electric water heater.

[Explanation of symbols]

1 container 2 heating means 3 Temperature detection means 4 Boiling detection means 7 Empty cooking detection means 8 Hot water means 9 Hot water means 10 Control means

Claims (10)

[Claims] 1. A container for containing a liquid, a heating means for heating and keeping the liquid in the container, and a heating means for a short time until the temperature in the container is detected to be equal to or higher than a first predetermined temperature. An electric water heater characterized by. 2. The electric water heater according to claim 1, wherein the heating means is operated for a short period of time every first predetermined time. 3. The heating means is operated for a short time until the temperature difference before and after the heating means is operated for a short time becomes equal to or more than a predetermined value.
The electric water heater described in. 4. The electric water heater according to any one of claims 1 to 3, wherein when the temperature is equal to or higher than a predetermined temperature or a temperature difference is equal to or higher than a predetermined value, a notification is given. 5. The electric water heater according to any one of claims 1 to 4, wherein the heating means is operated for a short time during a heat retention operation. 6. The method according to claim 1, wherein the heating means is operated for a short time during a heat retention operation and a standby operation.
The electric water heater according to claim 4. 7. The electric water heater according to any one of claims 5 to 6, wherein the heating means is configured to perform a short time operation a predetermined number of times. 8. The electric water heater according to claim 7, wherein when the hot water discharge operation is performed, the short-time operation of the heating means is restarted. 9. The electric water heater according to any one of claims 1 to 8, wherein when the presence of water in the water heater is detected, the heating means is stopped for a short time. 10. The method according to any one of claims 1 to 9, wherein when the presence of water in the boiling water is detected, the short-time operation of the heating means is stopped until a hot water operation is performed thereafter. Electric water heater.