JP3185117B2 - Electric water heater - Google Patents

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 keeping water contained in a container.

[0002]

2. Description of the Related Art In recent years, electric water heaters have become multifunctional, and have not only a function of simply heating and keeping water warm, but also a function of changing some kinds of warming temperature and a purifying function of converting water into delicious water. It is being developed, but its usability during a power outage is an issue.

[0003] A conventional electric water heater will be described below. FIG. 8 is a partial cross-sectional block diagram showing a configuration of a conventional electric water heater. In FIG. 8, a container 2 having an upper surface opening is provided in an electric water heater main body container 1, and a lid 3 for covering the opening is disposed above the container 2. Further, a heating source 4 having a heater for heating water inside the container 2 and a heat retaining heater for keeping the temperature warm, and a temperature sensor 5 for detecting the water temperature inside the container 2 are provided below the container 2. Are located. The temperature detecting means 6 detects a water temperature based on a signal from the temperature sensor 5. The heating source 4 is controlled to be energized by the heating and heat control means 7.

The timer setting means 9 is a means for setting a rest time until water starts to be boiled by the heater. The timer setting means 9 is constituted by a push switch, for example. The heat retention temperature setting means 11 and the boiling mode setting means 12 have the same configuration as above, and the heat retention temperature setting condition and the boiling mode setting condition are input to the heating heat retention control means 7. The heating / warming control means 7 displays the conditions of the pause time, the warming and the boiling mode on the display means 10. 10a indicates a rest time, 10aa indicates a light emitting diode (hereinafter, referred to as an LED) indicating that the time to start boiling water is 2 hours, 10ab indicates an LED indicating that it is 6 hours, and 10ac indicates an 8 hours. Is an LED indicating that For example, when the power is turned on, the timer display means 10a are all turned off and the heating is set to start immediately. However, each time the switch of the timer setting means 9 is pressed once, the pause time is 2 hours, 6 hours. It switches cyclically to time, 8 hours, all lights off, 2 hours.

[0005] The heat retention temperature setting means 11 displays the heat retention conditions on the heat retention display means 10b of the display means 10. 10ba
Is an LED that indicates that the temperature is maintained at a high temperature of about 95 ° C, 10bb is an LED that indicates that the temperature is maintained at about 85 ° C, and 10bc is that the temperature is maintained at about 70 ° C. Are displayed. At the time of turning on the power, the high-temperature insulation is set.
Each time the switch is pressed once, the temperature switches cyclically between 85 °, 70 °, and high temperature, and the display LE
D switches cyclically to 10 ba, 10 bb, 10 bc, and 10 ba and lights up.

The boiling mode setting means 12 displays the boiling mode by means of the boiling mode display means 10c of the display means 10. 10ca indicates a normal boiling mode in which the heating is stopped when the water boils and the operation shifts to a heat retaining operation, and 10cb indicates a mode in which the boiling is continued for a predetermined time after the boiling. The mode in which boiling continues for a predetermined time corresponds to, for example, a water purification mode in which water is circulated by a pump or the like while being heated, filtered, the circulation is stopped when boiling, and the operation is continued for a while to purify water. Each time the switch of the boiling mode setting means is pressed once, the normal boiling mode 10ca,
The LED of the water purification mode 10cb switches and lights up.
When the power is turned on, a normal boiling mode is set.

The power failure detecting means 13 detects a power failure of the power supply ,
Detects the power failure several milliseconds after disconnecting the power supply ,
The power outage detection signal is output to the heating and heat control means 7. Upon receiving the power failure detection signal, the heating / warming control means 7 immediately turns off the warming display means 10b and the boiling display means 10c, and stops the output to the heating source 4 and the circulation means 15. When the power is restored within a predetermined time, for example, within 2 to 3 seconds, the drive power supply voltage of the heating and heat keeping control means 7 is held by an electrolytic capacitor or the like. , Heat retention conditions and boiling mode conditions are maintained.

[0008]

In such a conventional electric water heater, when the power outage time is long, or when the power in the container is disconnected from the power supply for a long time, for example, when the water in the container is replaced, the heating and heat control means is used. Since the driving power supply voltage cannot be maintained, the operating condition disappears, and a new condition must be set when the power is turned on again, which causes a problem that the operation is troublesome.

The present invention solves the above-mentioned problems, and when power is restored from a power failure, operating conditions and operating states before the power failure are restored.
Automatically without having to press the switch several times to reset
It is an object to provide an electric water heater that can be set .

[0010]

In order to achieve the above object, the present invention provides a container for containing a liquid, a heating source for heating the liquid, a temperature detecting means for detecting the temperature of the liquid, Insulation temperature setting means that can set the insulation temperature of the liquid in multiple stages , and a long-term power outage or long-term disconnection of the power supply
A power outage detecting means for detecting the occurrence of the power failure, a storage means for long-term storage of the setting conditions and the operation state before the power outage is detected when the power outage is detected, and controlling the heating start, the boiling and the heat retaining operation of the liquid. and control means, the control means recovery
When the power is turned on, the current temperature and the settings set in the storage
If the temperature difference from the condition is within a predetermined temperature range,
The temperature is controlled so that the temperature reaches
If the temperature is lowered to the upper Ru der those to control so that the set temperature after boiled by starting heating. In addition, the temperature of the liquid can be set in multiple stages.
The temperature and temperature setting means and the mode for boiling the liquid
It has boiling mode setting means that can set several stages.
You. Further, a timer setting means for setting dwell time of 1 or more until the start of heating the liquid, control means to control so as to start heating by referring to the quiescent time stored in the storage means at the time of power recovery It was done. further,
The control means performs control so that heating is started by correcting the time during the power failure to the pause time stored in the storage means when power is restored .
That's what I did.

[0011]

According to the present invention, in the above configuration, the control means detects the power failure by the power failure detection means, stores the operating conditions set before the power failure and the operation state before the power failure in the storage means, and recovers the power from the power failure. When the power is restored, the heating and heat keeping operation is controlled with reference to the operating condition and operating state stored in the storage means.

[0012]

【Example】

(Embodiment 1) Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a partial cross-sectional block diagram showing the configuration of an electric water heater according to a first embodiment of the present invention. In the figure,
The same components as those in the conventional example shown in FIG. 8 are denoted by the same reference numerals, and detailed description will be omitted. The constituent elements of the electric water heater of the present invention different from those of the conventional example are the provision of the storage means 14 and the operation of the control means 8.

In FIG. 1, when the power failure detecting means 13 detects a power failure, the control means 8 stores in the storage means 14 the set pause time, the heat retention temperature, the boiling mode, and whether the operation state is boiling or heat retention. . When the power is restored from the power failure, the control means 8 reads the pause time, the heat retention temperature, the boiling mode, and whether the operation before the power failure was boiling or the heat retention stored in the storage means 14, and displayed these conditions on the display means 1.
0 is displayed, and the operation is restarted with reference to those conditions. For example, the driving of the heating source 4 and the circulation unit 15 is controlled by the temperature data of the temperature detecting unit 6. The power is interrupted during operation in the normal boiling mode, and when the power is restored several hours later, the mode is restarted. Further, if a power failure occurs during the heat retention, after the power is restored, the temperature data of the temperature detecting means 6 is compared with the stored set temperature data. If the temperature difference is within a predetermined temperature difference, the heat retention is continued. After boiling according to the boiling mode called from the means 14, control is performed so as to keep the temperature at the set temperature. The display corresponding to the operation is displayed on the display unit 1.
Performed with 0.

FIG. 2 is a circuit diagram showing an electric configuration of an electric water heater according to one embodiment of the present invention. In the figure, 4a is a heating heater, 4b is a heating heater, 5 is a thermistor as a temperature sensor, 6a to 6h are resistors and A which constitute the temperature detecting means 6.
/ D converters, 13a, 13b and 13c are resistors, 8a, 8b and 8c, 8d and 8 constituting a power failure detecting means.
e is a microcomputer, a relay, a thyristor, and an electrolytic capacitor constituting control means,
Numerals 1 and 12 denote a timer setting switch as a means for setting a pause time, a temperature setting switch as a temperature setting means, and a boiling mode setting switch as a mode setting means, 10a a timer display means, 10b a temperature display means. Reference numeral 10c denotes boiling mode display means, 14 denotes a non-volatile memory forming storage means, 15a and 15b denote motors and drive circuits forming water circulation means, 17 denotes an AC power supply, and a block diagram shown in FIG. It corresponds to.

The microcomputer 8a controls the relay coil 8c and the thyristor 8d to control the amount of electricity supplied to the heater 4a and the heater 4b. In the boiling mode for boiling water, the microcomputer 8a connects the relay contact 8b by the relay coil 8c to energize the heater 4a. When the water is kept warm after boiling, the microcomputer 8a operates the thyristor 8d to energize the warming heater 4b. In the water purification mode in which the water is circulated to filter and boil while filtering, the microcomputer 8a connects the contact 8b by the relay coil 8c to energize the heater 4a, and the motor drive circuit 1
The motor 15a is driven by 5b to circulate water, and when the water boils, the driving of the motor 15a is stopped, the boiling is maintained for several minutes, and then the operation shifts to a heat retaining operation. The driving DC power supply of the microcomputer 8a or the like is generally generated from an AC power supply and loses its driving voltage when a power failure occurs.
The stored charge is used.

When the voltage of the power supply 17 is lowered and the power is cut off, the combined voltage of the AC power supply voltage and the predetermined DC voltage is changed to a point A in the figure by the resistor 13a and the resistors 13b and 13c connected to one end of the power supply 17. The voltage is input to the microcomputer 8a to perform zero volt detection of the AC power supply 17 (hereinafter referred to as SNS detection in the present invention). FIG. 3 is a timing chart showing the SNS detection operation. In the embodiment, the predetermined DC voltage is set to Ｖ Vdd while the resistance values of the resistors 13 b and 13 c are the same. The SNS detection signal is supplied to the microcomputer 8
When input to the microcomputer a, the input signal is clamped by the diode in the microcomputer 8a, so that the waveform becomes a square wave shown in FIG. 3B. (A) shows an AC power supply waveform. In addition, the DC voltage of 1/2 Vdd
Assuming the reference voltages V1 and V0 above and below, the microcomputer 8a detects a case where the SNS signal has a voltage change waveform that crosses the aforementioned V0 and V1 as shown in FIG. In the case of other voltage change waveforms, a "low" level is detected. In the case of a power failure, the SNS signal is １ ／ Vdd, so it does not cross V0 and V1, and thus corresponds to the “low” level.

For reference, a detection waveform of the microcomputer 8a corresponding to the SNS signal is shown in FIG. The “high” level of the SNS signal corresponds to a pulse waveform having a width of about several hundred μs, and the “low” level of the SNS signal corresponds to a trapezoidal waveform. The microcomputer 8a determines that a power failure has occurred when the "low" level continues for several ms.
This operation also occurs when the AC power supply voltage drops significantly.

When the microcomputer 8a detects a power failure, the pause time set at that time, the boiling mode,
The storage means 14 stores data such as the heat retention temperature and whether the operation state at that time is boiling or heat retention. Storage means 1
Numeral 4 is a non-volatile memory that can maintain the memory for more than 10 years, for example.
It is connected so that data can be input and output.

On the other hand, the resistance value of the temperature sensor 5 mounted in pressure contact with the container 2 changes in accordance with the temperature of the water in the container 2. Therefore, the DC voltage obtained by dividing the driving power supply voltage Vdd by the resistor 6a connected in series with the temperature sensor 5 changes according to the liquid temperature. This voltage is input to the A / D converter 6b as a signal corresponding to the temperature of the liquid, converted into a digital value, and input to the microcomputer 8a. Further, the voltage determined by the resistors 6c and 6d, the voltage determined by the resistors 6e and 6f, and the voltage determined by the resistors 6g and 6h are respectively the temperature at the time of high temperature keeping (about 95 degrees C), 85
Temperature at the time of heat insulation (about 85 degrees C), temperature at the time of 70 heat insulation (about 7
The voltage corresponding to 0 ° C) is input to the A / D converter 6b.

When the power is restored, the microcomputer 8a calls whether the operating state before the power failure stored in the storage means 14 is boiling, warming, or during the downtime. If there is, the LED for the time set by the timer display means 10a is turned on, and the start of heating is waited for the stored time.
If it is in the boiling mode, the stored boiling mode is continued and a predetermined L of the boiling display means 10c is set.
Turn on the ED. Also, if the temperature is being kept warm, the temperature data from the temperature detecting means 6 is used to keep the temperature kept within the predetermined temperature range if the temperature is within the predetermined temperature range. If so, after boiling in the boiling mode called from the storage means 14, control is performed so as to keep the temperature at the set temperature, and the LEDs corresponding to the boiling mode display means 10c and the heat retention display means 10b are turned on.

When the user wants to change the heat retention temperature, the user presses the switch of the heat retention temperature setting means 11 to display the heat retention display means 1.
The temperature is changed to the warming temperature indicated by the lit LED of 0b. When it is desired to change the boiling mode, the boiling mode setting means 12
Is changed to the boiling mode indicated by the lit LED of the boiling mode display means 10c.

The operation when the power is turned on or when the power is restored after a power failure will be described below with reference to FIGS. 4, 5 and 6. FIG. 4 is a schematic flowchart showing the operation of one embodiment of the present invention, and FIGS. 5 and 6 are flowcharts showing details of steps 1 and 2 in FIG. 4, respectively. In step 100, the SNS signal of the power failure detection means 13 is checked to detect power recovery. When the power is restored and the SNS signal becomes “high” level, in step 101, the heat retention data and the boiling mode data from the storage means 14, the operation state as to whether the operation state is the boiling mode or the heat retention,
If the pause time has been set, the set pause time until the start of heating is captured. In step 102, it is checked whether or not the pause time is set. If the pause time is set, the process proceeds to step 103 to display the pause time and measure the time. Transition. If the pause time has not been set in step 102, the process proceeds to step 104 to check whether the operating state before the power failure was boiling or warming. If it is boiling, the process goes to step 105 to start the operation and display of the boiling mode. If it is keeping the temperature, it goes to step 106 to set it.
The temperature difference between the maintained temperature and the current temperature is within the specified temperature range.
If it is within, the heat retention at the set temperature is reduced to a specified temperature range or more
If it is determined that the boiling
It is set after starting heating in the mode and boiling it
Insulate at temperature.

The process proceeds to step 107 in a state where the heat retention or the boiling is started, and the pause time setting is always checked.
This is to cope with the possibility that the user sets the pause time again. When the switch of the timer setting means 9 is depressed, the process proceeds to step 108 to display the pause time and measures the time. During this period, heating is not started. When the pause time ends, the setting is canceled and the process proceeds to step 109. In step 109, it is checked whether the switch of the boiling mode setting means 12 has been pressed. This is to cope with the possibility that the user sets the boiling mode again. If the switch of the boiling mode setting means 12 is depressed, the process proceeds to step 110, and the operation and display of the boiling mode are started. If the switch of the boiling mode setting means 12 has not been pressed, the flow shifts to step 111 to check whether the heat retention temperature setting switch has been pressed. This is to cope with the possibility that the user sets the heat retention temperature again. If the switch of the heat retaining temperature setting means 11 has been pressed, the process proceeds to step 112 to start the operation and display of the heat retaining temperature, and if not, the process proceeds to step 113.

With the above operation, the operation according to the set conditions is started, and the process proceeds to step 113. In step 113, when these operations are started, the process waits for several ms. During this time, the SNS signal is constantly checked in step 114. If the input of the SNS signal is at the “low” level, the power failure continues, so it is determined that the power failure has occurred, and the process proceeds to step 115. If the SNS signal is not at the "low" level in step 114, the process returns to step 107 to continue the normal operation. In step 115, the display is turned off and the operation is stopped in response to the power failure. Then, the process proceeds to step 116 in which the currently set boiling mode, warming temperature, current operating state (boiling or warming), and pause are set. The time is set, or if set, the pause time until the start of heating is stored in the nonvolatile memory 14. Next, the process proceeds to step 117, where the SNS signal is checked to observe the continuation of the power failure. If the SNS signal is not at the "low" level, there is a possibility that the power has recovered, and the process returns to step 100 to check for the power recovery (see FIG. 6 for the above operation).

As described above, according to the embodiment of the present invention, the set operation conditions and the operation state before the power failure are stored in the storage means, and when the power is restored, the stored contents are automatically referred to by referring to the stored contents. Return to operation or once depending on the temperature difference from the set temperature
Since the set temperature is maintained after water heating is performed, there is no need to set operating conditions again when power is restored, and the electric water heater is very convenient for the user.

In this embodiment, a non-volatile memory is used as the storage means. However, a memory in the microcomputer is used as a storage element, and the memory is backed up by a capacitor, a primary battery, a secondary battery, or the like. Needless to say, it is good.

(Embodiment 2) Hereinafter, an electric water heater according to a second embodiment of the present invention will be described with reference to the drawings. The main components of this embodiment are the same as those of the first embodiment, and will be described with reference to FIGS. 1, 2, and 3. The second embodiment is different from the first embodiment in that a part of the control operation of the microcomputer 8a in FIG. 2 and the capacity of the capacitor 8a are made sufficiently large to cope with a long pause time. is there. The operation of the present embodiment is shown in a schematic flowchart in the same manner as in FIG. 4, and in step 1, the same operation as in the first embodiment shown in FIG. 5 is performed. However, the operation of step 2 is partially different from that of the first embodiment, and FIG. 7 shows the details of step 2 in a flowchart. In addition,
6 and 7, the same operation steps are given the same step numbers, and descriptions thereof are omitted.

In FIG. 7, the operation of this embodiment is different from that of the first embodiment in the operation of the added step 118. In this embodiment, as in the first embodiment, step 11 is executed.
At 7, it is checked whether the SNS signal is at the “low” level and the continuation of the power failure is checked. If the power failure is continuing, the process proceeds to step 118, and if the pause time is set, the power failure is continued. The elapsed time is measured, and the elapsed time of the power failure is subtracted from the pause time stored at the time of the power failure. Therefore, when power is restored, the time during the power failure is corrected from the stored pause time, and heating is started after the desired pause time when set. This means is effective when the power outage is long.

If the power outage lasts for a long time, a DC drive power supply must be supplied during this time for the control means such as the microcomputer 8a to operate normally. For this purpose, the capacity of the capacitor 8e inserted into the DC drive power supply is increased, for example, by using a large-capacity electrolytic capacitor or the like, so that the setting can cope with a power failure of several hours or tens of hours.

As described above, according to the second embodiment of the present invention, the pause time set before the power failure is counted down during the power failure and the power failure time is corrected, whereby the power failure time can be correctly corrected after the initially set pause time. Heating can be started. Of course, it is needless to say that the operating conditions do not need to be reset when the power is restored.

[0032]

As is clear from the above embodiments, the present invention provides a long-term power outage or a long-term disconnection of a power supply.
Power failure detection means for detecting the case where the power failure occurs, storage means for long-term storage of the set conditions and the operating state before the power failure when the power failure is detected, and control for controlling the start of heating, boiling and heat retention operations of the liquid Means to be stored in the storage means when power is restored.
Refer to the operating conditions and operating conditions
By controlling the temperature operation, when the power is restored or the power is turned on again, the setting mode is set to the mode of the warming temperature boiling and the pause time that is always used automatically without pressing the setting switch many times. This is an easy-to-use electric water heater that does not require the user to press the setting switch many times to reset the setting.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional block diagram illustrating a configuration of an electric water heater according to first and second embodiments of the present invention.

FIG. 2 is a circuit block diagram showing an electric configuration of an electric water heater according to first and second embodiments of the present invention.

3A and 3B are waveform diagrams showing waveforms of a power failure detecting means in the electric water heaters according to the first and second embodiments of the present invention. FIG. 3A is a waveform diagram showing an AC power supply waveform, and FIG. (C) is a waveform diagram showing the power failure detection waveform of the microcomputer

FIG. 4 is a flowchart showing a schematic operation of the electric water heater of the first and second embodiments of the present invention.

FIG. 5 is a flowchart showing in detail the operation of the electric water heater of the first and second embodiments in step 1 shown in FIG. 4;

FIG. 6 is a flowchart showing in detail the operation of the electric water heater of the first embodiment in step 2 shown in FIG. 4;

FIG. 7 is a flowchart showing the operation of the electric water heater of the second embodiment in step 2 shown in FIG. 4 in detail;

FIG. 8 is a partial cross-sectional block diagram showing a configuration of a conventional electric water heater.

[Explanation of symbols]

 2 container 4 heating source 5 temperature sensor (temperature detecting means) 6 temperature detecting means 8 control means 9 timer setting means (condition setting means) 11 heat retaining temperature setting means (condition setting means) 12 boiling mode setting means (condition setting means) 13 Power failure detection means 14 Storage means

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hironobu Tanaka 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-5-300831 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) A47J 27/21 101

Claims (4)

(57) [Claims] 1. A container for accommodating a liquid, a heating source for heating the liquid, a temperature detecting means for detecting a temperature of the liquid, a heat retaining temperature setting means capable of setting a plurality of liquid retaining temperatures. Prolonged power outage or prolonged disconnection of power
Power outage detecting means for detecting the occurrence of a power failure, storage means for long-term storage of set conditions and operating conditions before the power outage is detected when a power outage is detected, and control of the start of heating, boiling and heat retaining operations of the liquid. Control means for performing the control, wherein the control means
When the power is restored, the current temperature and the settings set in the storage
If the temperature difference from the fixed condition is within the specified temperature range,
Performs a heat-retention operation to reach the specified temperature
<br/> electric water heater temperature was so controlled to the set temperature after boiled by starting the heating if you are reduced more than. 2. Insulation that can set the insulation temperature of a liquid in a plurality of stages.
Temperature setting means and multiple modes for boiling liquid
2. The electric water heater according to claim 1, further comprising a boiling mode setting means capable of setting a step . 3. The pause time until the liquid starts heating is set to 1
A timer setting means capable of setting or more, the control means electrical water heater according to claim 1, wherein the controls to start heating by referring to the quiescent time stored in the storage means at the time of power restoration. 4. The electric water heater according to claim 3, wherein the control means controls the start of heating by correcting the time during the power failure to the pause time stored in the storage means when the power is restored.