JPH0937940A - Electric water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric water heater, in which the circulation performance is secured by removing air accumulated in a motor-driven pump to keep the water purifying performance. SOLUTION: This electric water heater comprises a circulating means for forcedly circulating a liquid in a container by the use of a motor-driven pump, and a filter means 8 for removing undesired matter of a liquid fed by the circulating means, wherein the heater further comprises an on-off means 13 for turning on the circulating means for the first arbitrary amount of time, then once turning off the circulating means and again turning on the circulating means at the time of starting the drive of the circulating means.

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.

[0002]

2. Description of the Related Art In recent years, an electric water heater equipped with a function of making delicious water has the following structure. That is, it was a circulating purified water type in which a liquid in a container was circulated through a water pipe connected to the bottom and an upper part of the container and an unnecessary substance was removed by placing a filtering means in this circulation path.

FIG. 11 shows a simple structure of the circulation means. The wing 22 attached to the rotary shaft of the electric motor 21 and the pump case 23 covering the wing 22 constitute an electric pump. This electric pump has one outlet at the bottom of the container 24,
The other end is connected to the water pipe 25, and the other end of the water pipe 25 is connected to the upper portion of the container 24 to form a circulation path. Filtration means is mounted in the liquid circulation path above the container.

When the electric motor 21 is driven with such a structure, the liquid flowing from the bottom of the container 24 into the pump case 23 is pumped up from the water pipe 25 to the upper part of the container 24 by the rotation of the blades 22, so that the filtering means is used. Can be passed through.

[0005]

However, in such a conventional structure, if air remains in the pump case 23, the vanes 22 tend to spin even if the wing 22 rotates, and in order to overcome this problem. The rotation speed of the electric motor 21 is increased so that the electric motor 21 can be pumped up even if some air is mixed therein.

However, in recent years, as the capacity of the electric water heater has increased and the difference in stroke between the upper and lower portions of the container has increased, it has become necessary to increase the rotation speed more than ever. On the other hand, as customers' demands for electric water heaters are increasing, complaints about loud noise at the time of water heating are increasing, and the rotation of the electric motor 21 has to be slowed down. It has become difficult to remove unnecessary substances.

The present invention solves such a problem by removing the air in the pump case at the start of circulation.
A first object is to sufficiently circulate a liquid with a small number of rotations of an electric motor.

Further, immediately before boiling, the air contained in the liquid foams and a large amount of air is accumulated again in the pump case and does not circulate. Therefore, it is necessary to stop the operation to improve the silent effect. The purpose of.

Further, even if the air contained in the liquid foams and the air again accumulates in the pump case as the temperature rises during boiling, it is necessary to remove it to secure the circulation amount. The purpose of.

[0010]

In order to achieve the first object, the first means of the present invention is a container for containing a liquid, a heating means for heating the liquid in the container, and the heating means. Energizing means for controlling the energization of, a heating starting means for starting the driving of the heating means, a temperature detecting means for detecting the temperature in the container, a circulating means for forcibly circulating the liquid in the container, Filtering means for removing unnecessary substances of the liquid sent by the circulating means, boiling detecting means for stopping the energizing means and the circulating means when the boiling is detected by the input of the temperature detecting means, and the temperature during heating. It has a control means for driving the circulation means when the first predetermined temperature is reached by an input of the detection means, and an instantaneous circulation stop operation for stopping the operation of the circulation means for a short time during the driving of the circulation means. And electric kettle.

Further, in order to achieve the second object, in addition to the first means, the second means of the present invention is such that the instantaneous circulation stop operation is a predetermined operation when the driving of the circulation means is started. It is assumed to be controlled by the on / off means that controls the operation of the time circulation means.

Further, in order to achieve the third object, the third means of the present invention is to stop the driving of the circulation means when the temperature detecting means reaches a second predetermined temperature near the boiling temperature. It is assumed that stop means is provided.

In order to achieve the fourth object, the fourth means of the present invention detects that the temperature detecting means has reached a third predetermined temperature which is higher than the first predetermined temperature,
It is characterized in that the on / off means for controlling the operation of the circulation means for a predetermined time is operated.

Further, in order to achieve the fifth object, the fifth means of the present invention is provided with a time measuring means for measuring the drive time of the control means, and the on / off means is provided every time the time measuring means measures a predetermined time. It is characterized by working.

[0015]

According to the present invention, with the above-described structure, the circulation is temporarily stopped when the circulation is started, so that the air stored in the pump case is pushed back into the container by the pressure in the water pipe that is lifted to a position slightly higher than in the container. It can be removed by, and thus can be sufficiently circulated thereafter.

Further, by stopping at a place where circulation is almost impossible immediately before boiling detection, the motor noise can be eliminated at a place where the boiling water noise is loudest immediately before boiling, which can contribute to noise reduction.

Further, by stopping the circulation again during the circulation, the air accumulated in the pump case can be removed again and the circulation ability can be maintained.

[0018]

【Example】

(Embodiment 1) A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a block diagram of an electric water heater according to a first embodiment of the present invention, wherein 1 is a container for containing a liquid, 2 is a heating means for contacting the container 1 and heating water in the container 1, and 3 is a container 1 Temperature detecting means 4 for detecting the temperature in the container 1 which is in contact with the heating means 2 is an energizing means for energizing the heating means 2.

The pump case 6 attached to the electric motor 5 is provided with a discharge port below the container 1 and a water guide tube 7 so that the container 1
A circulation channel 9 is formed above the above to form a water channel and send out water. The water circulated in the container 1 by the circulation means 9 is returned to the container 1 through the filtration device 8 containing activated carbon and the like.

Numeral 10 is a heating starter, which may be any starter for heating the liquid in the container. Here, for example, it is a start switch for forcibly starting the heating, and the input of the temperature detector 3 is arbitrary. It is an automatic boiling means or the like that automatically starts heating when the temperature becomes lower than the temperature (for example, 90 ° C.).

Reference numeral 11 is a boiling detection means, and when the heating means 2 is driven, an input of the temperature detection means 3 detects a temperature equal to or higher than a fourth predetermined temperature (about 80 ° C. in this embodiment), and a unit temperature thereafter. (In this embodiment, it is set to about 0.5 ° C.) Each time the temperature rises is measured, and if the temperature rise cannot be detected even after the elapse of the first specific time (25 seconds in this embodiment), the energizing means is used. Stop 4

Reference numeral 12 is a control means, and 13 is an on / off means. The control means 12 receives a first predetermined temperature (30 ° C. in this embodiment) by the input of the temperature detection means 3 during heating.
When the above is reached, the circulation means 9 is driven and at the same time the on / off means 13 is driven. The on / off means is configured to turn on / off the circulation means for a second specific time (12 seconds on, 3 seconds off in this embodiment).

FIG. 2 is a circuit diagram of the electric water heater according to the first embodiment of the present invention. In FIG. 2, 16 is an AC power supply,
Reference numeral 17 is a DC power supply. The heating means 2 comprises a first heating element 2a for heating the liquid in the container and a second heating element 2b for heating the liquid in the container with a lower heating power than the first heating element 2a. The energizing means 4 is composed of relay contacts 4a and 4b connected in series with each heating element of the heating means 2 and the AC power source 16, and relay coils 4c and 4d for controlling the relay contacts 4a and 4b. A current is passed through the coil to close the relay contact. The temperature detecting means 3 is composed of a temperature sensitive element 3a for converting temperature into a resistance value and an AD converter 3b for converting the value of the temperature sensitive element 3a into a binary code. The electric motor 5 is connected to a motor drive circuit 18, and by controlling the motor drive circuit 18, the electric motor 5 is turned on / off to control circulation.

The heating start switch of the heating start means 10 is
This input makes it possible to forcibly re-energize the energizing means 4, and a signal is sent by turning the switch on and off, which is composed of the switch 10a and the resistor 10b. Reference numeral 19 denotes a display means for notifying outside that the state of the inside of the container is heating, keeping heat, etc., and is constituted by using LEDs 19a and 19b, a buzzer 19c and the like. Reference numeral 20 denotes a microcomputer (hereinafter abbreviated as a microcomputer).

FIG. 3 shows the microcomputer 2 of the first embodiment of the present invention.
The flowchart of the temperature control part of the program stored in 0 is shown, and the control method of the boiling detection means 11, the control means 12, and the on / off means 13 is implemented by executing this. Hereinafter, this operation will be described.

The heating means 2 is driven when the temperature is below the specified temperature during the temperature control of the heat retention (step 1) or when the power is turned on, or when the reheating switch 10a is input (step 2). (Step 3) Then, in Step 4, it is detected whether or not the temperature becomes equal to or higher than the first predetermined temperature.

When the temperature exceeds the first predetermined temperature in step 4, the circulation means 9 is turned on in step 5, and at the same time, the on / off means 13 is driven in step 6. The control method of the on / off means 13 is a sub-program, which will be described later.

Next, in step 7 and subsequent steps, boiling detection processing is performed. When it is detected in step 7 that the temperature has reached the fourth predetermined temperature or higher, in step 8, the measuring means measures the time for which the unit temperature rises, and in step 9, whether the unit temperature rise is detected by the input of the temperature detecting means 3. To judge. If the unit temperature rise is detected in step 9, the measurement value of the measuring means is cleared (step 13), and the process returns to step 8 in order to measure the time for a new unit temperature rise.

On the other hand, when the unit temperature rise is not detected in step 9, it is determined in step 10 whether boiling is detected. In the present embodiment, the boiling detection uses the fact that the temperature does not rise when the boiling point is reached, and detects the time when the value measured by the measuring means exceeds the first specific time.

If boiling is not detected in step 10, the measuring means continues to count time in step 8. When boiling is detected in step 10, the circulation means 9 is detected in step 11.
At the same time that the heating means 2 is stopped, the heating means 2 is stopped and the boiling detection display and notification are performed by the display means 19 in step 12, and the process returns to step 1.

FIG. 4 is a sub-program showing the on / off control, and the on / off control part of the circulation means 9 will be described below. When this subprogram is executed while the circulation means 9 is driven, step 21
The measurement means is initialized by and the measurement is started. Next, time is measured in steps 22 and 23, and the process stands by until the first predetermined time (12 seconds in this embodiment) elapses. When the first predetermined time has elapsed in step 23, step 24
The driving of the circulation means 9 is stopped at step 25, and the process waits at steps 25 and 26 until the second predetermined time (3 seconds in this embodiment (15 seconds in total)) has elapsed. When the second predetermined time has elapsed in step 26, the circulating means 9 is re-driven to return to the return destination of the subprogram.

With the above-mentioned simple structure, the air trapped in the pump case can be removed, and the circulating water purification can be performed.

In this embodiment, the circulation start temperature is set to the first
Although the temperature is set to be equal to or higher than the predetermined temperature, it is possible to perform this from the start of boiling water.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIGS. 5 and 6. The same components as those described in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 5 is a block diagram of an electric water heater according to a second embodiment of the present invention. The differences from the first embodiment are as follows.
Where the stopping means 14 is added, the temperature detected by the temperature detecting means 3 is the second predetermined temperature (95 in this embodiment).
When it reaches (° C.), the circulation means 9 is stopped.

FIG. 6 shows a flow chart of the temperature control portion of the program stored in the microcomputer 20 of the second embodiment, and the operation will be described with this.

Similar to FIG. 3, if the temperature is below the specific temperature or the reheat switch 10a is input during the temperature control of the heat retention (step 31) or when the power is turned on (step 32), The heating means 2 is driven (step 33), and in step 34 it is detected whether or not the temperature has reached the first predetermined temperature or higher. When the temperature exceeds the first predetermined temperature in step 34, the circulation means 9 is turned on in step 35, and at the same time, the on / off means 13 is driven in step 36. The control method of the on / off means 13 is a sub-program and is shown in FIG.

Next, after step 37, boiling detection and circulation stop processing are performed. When it is detected in step 37 that the temperature is equal to or higher than the fourth predetermined temperature, it is determined in steps 38 and 39 whether or not the temperature reaches the second predetermined temperature or higher by the input of the temperature detecting means 3, and the second temperature is detected. If the temperature is equal to or higher than a predetermined temperature, the circulation means 9 is stopped. next,
In step 40, the measuring means measures the time during which the unit temperature rises, and in step 41 it is judged whether or not the unit temperature rise is detected by the input of the temperature detecting means 3. If the unit temperature rise is detected in step 41, the measurement value of the measuring means is cleared (step 44), and the process returns to step 38 in order to measure the time for a new unit temperature rise.

On the other hand, when the unit temperature rise is not detected in step 41, it is determined in step 42 whether boiling is detected by the above-mentioned method. If boiling is not detected in step 42, the measuring means further continues time counting in step 38. When boiling is detected in step 42, the heating means 2 is stopped in step 43 and the display means 19 is activated.
The boiling detection display and notification are performed by step 31.
Return to With the simple configuration as described above, the circulation can be stopped immediately before boiling.

It should be noted that it is easy to perform the process of turning off the circulation means again when boiling is detected, taking into consideration the case where boiling is detected at a temperature lower than the circulation stop temperature when used in a place where the atmospheric pressure is low.

(Third Embodiment) A third embodiment of the present invention will be described with reference to FIGS. 7 and 8. The same components as those described in the first and second embodiments are designated by the same reference numerals and the description thereof will be omitted.

FIG. 7 is a block diagram of an electric water heater according to a third embodiment of the present invention. The difference from the first and second embodiments is that the on / off means 13 is driven by the input of the temperature detecting means 3. By the way, the temperature detected by the temperature detecting means 3 is the third predetermined temperature (70 ° C. in this embodiment).
Is reached, the on / off means 13 is re-driven.

FIG. 8 shows a flow chart of the temperature control portion of the program stored in the microcomputer 20 of the third embodiment, and the operation will be described with this.

Similar to FIG. 3, when the temperature is lower than the specific temperature or the reheating switch 10a is input during the temperature control of the heat retention (step 51) or when the power is turned on (step 52), The heating means 2 is driven (step 53), and in step 54 it is detected whether or not the temperature has reached the first predetermined temperature or higher. When the temperature exceeds the first predetermined temperature in step 54, the circulation means 9 is turned on in step 55, and at the same time, the on / off means 13 is driven in step 56. The control method of the on / off means 13 is a sub-program and is the same as that of FIG. 4 described above. Further, when the temperature exceeds the third predetermined temperature in step 57, the on / off means 13 is re-driven in step 58.

Next, after step 59, boiling detection and circulation stop processing are performed. When it is detected in step 59 that the temperature has reached the fourth predetermined temperature or higher, it is determined in steps 60 and 61 whether or not the temperature has reached the second predetermined temperature or higher by the input of the temperature detection means 3, and the second If the temperature is equal to or higher than a predetermined temperature, the circulation means 9 is stopped.

Next, at step 62, the measuring means measures the time during which the unit temperature rises, and at step 63, the temperature detecting means 3
It is determined whether the unit temperature rise is detected by inputting. If the unit temperature rise is detected in step 63, the measurement value of the measuring means is cleared (step 66), and the process returns to step 60 in order to measure the time for a new unit temperature rise.

On the other hand, when the unit temperature increase is not detected in step 63, it is determined in step 64 whether boiling is detected by the above-described method. If boiling is not detected in step 64, the measuring means further continues time counting in step 60. When boiling is detected in step 64, the heating means 2 is stopped in step 65 and the display means 19 is activated.
The boiling detection display and notification are performed by step 51.
Return to

With the simple structure as described above, the circulation can be temporarily stopped during the boiling of the water, so that the liquid in the container can be sufficiently circulated.

In this embodiment, the operation is temporarily stopped only at the third predetermined temperature, but the same operation can be easily performed at any desired temperature.

(Embodiment 4) A fourth embodiment of the present invention will be described with reference to FIGS. 9 and 10. In addition,
The same components as those described in the first and second embodiments are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 9 is a block diagram of an electric water heater according to a third embodiment of the present invention. The difference from the first and second embodiments is that the time measuring means 15 is added and the circulating means 9 is added.
Is driven, the ON / OFF means 13 is re-driven every time a predetermined time (3 minutes in this embodiment) is started and timed.

FIG. 10 shows a flow chart of the temperature control portion of the program stored in the microcomputer 20 of the third embodiment, and the operation will be described with this.

Similar to FIG. 3, when the temperature is below the specified temperature during the temperature control of the heat retention (step 71) or when the power is turned on, or when the reheat switch 10a is input (step 72), The heating means 2 is driven (step 73), and in step 54 it is detected whether or not the temperature exceeds the first predetermined temperature. When the temperature exceeds the first predetermined temperature in step 74, the circulation means 9 is turned on in step 75, and at the same time, the on / off means 13 is driven in step 76. The control method of the on / off means 13 is a sub-program and is the same as that of FIG. 4 described above.

Next, at step 77, the time counting by the time counting means 15 is started. Then, it is judged whether or not the time during the time counting by the time counting means 15 has passed the predetermined time (step 7).
8) If the time has not elapsed, go to step 81. If the time has passed, the on / off means 13 is re-driven at steps 79 and 80 to clear the value of the time measuring means 15 and go to step 81. In step 81, it is judged whether or not the temperature becomes equal to or higher than the fourth predetermined temperature, and steps 77 to 81 are repeated until the temperature becomes equal to or higher than the fourth predetermined temperature. When it is detected in step 81 that the temperature has reached the fourth predetermined temperature or higher, steps 82, 8
In step 3, it is determined whether or not the temperature reaches the second predetermined temperature or higher by the input of the temperature detection means 3, and if the temperature is equal to or higher than the second predetermined temperature, the circulation means 9 is stopped.

Next, at step 84, the measuring means measures the time during which the unit temperature rises, and at step 85 it is judged whether or not the unit temperature rise has been detected by the input of the temperature detecting means 3. If the unit temperature rise is detected in step 85, the measurement value of the measuring means is cleared (step 88), and the process returns to step 82 in order to measure the time for a new unit temperature rise.

On the other hand, when the unit temperature rise is not detected in step 85, it is determined in step 86 whether boiling is detected by the above-mentioned method. If boiling is not detected in step 86, the measuring means further continues to measure time in step 82. When boiling is detected in step 86, the heating means 2 is stopped in step 87 and the display means 19 is activated.
The boiling detection display and notification are performed by step 71.
Return to

With the simple structure as described above, the circulation can be temporarily stopped during the boiling of the water, so that the liquid in the container can be sufficiently circulated.

In this embodiment, the on / off control is not performed at the second predetermined temperature, but it can be easily performed at this temperature or higher.

[0059]

As is apparent from the description of the above embodiments, the present invention removes the air that has entered the electric pump to maintain the circulation capacity even when the rotation speed of the electric motor is reduced. Therefore, the water purification performance can be ensured and the noise can be reduced when boiling water.

Further, by stopping at a place where it is almost impossible to circulate immediately before boiling detection, it is possible to eliminate the motor noise at the loudest water boiling noise, and to provide a quiet electric water heater.

Further, the air in the pump case can be removed again during the circulation, and the circulation capacity can be sufficiently maintained until the end of the circulation.

From the above, it is possible to provide a high-quality electric water heater that is easy to use.

[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 a circuit diagram of the electric water heater.

FIG. 3 is a flowchart showing the operation of the electric water heater.

FIG. 4 is a flowchart showing the operation of the electric water heater.

FIG. 5 is a block diagram of an electric water heater according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the electric water heater.

FIG. 7 is a block diagram of an electric water heater according to a third embodiment of the present invention.

FIG. 8 is a flowchart showing the operation of the electric water heater.

FIG. 9 is a block diagram of an electric water heater according to a fourth embodiment of the present invention.

FIG. 10 is a flowchart showing the operation of the electric water heater.

FIG. 11 is a schematic view of a main part of a conventional electric water heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Heating means 3 Temperature detecting means 4 Energizing means 9 Circulating means 10 Heating starting means 11 Boiling detecting means 12 Control means 13 On / off means

Claims (5)

[Claims] 1. A container for containing a liquid, a heating unit for heating the liquid in the container, an energizing unit for controlling energization of the heating unit, a heating starting unit for starting driving of the heating unit, Temperature detection means for detecting the temperature in the container,
Circulating means for forcibly circulating the liquid in the container, filtering means for removing unnecessary substances in the liquid fed by the circulating means, and the energizing means and the means for detecting boiling when the temperature detecting means is input. The boiling detection means for stopping the circulation means, the control means for driving the circulation means when the first predetermined temperature is reached by the input of the temperature detection means during heating, and the operation of the circulation means during the driving of the circulation means. An electric water heater having an instantaneous circulation stop operation for stopping for a short time. 2. The electric water heater according to claim 1, wherein the instantaneous circulation stop operation is controlled by an on / off means for controlling the operation of the circulation means for a predetermined time when the driving of the circulation means is started. 3. The electric water heater according to claim 1, wherein the temperature detecting means is provided with a stopping means for stopping the driving of the circulating means when the temperature detecting means reaches a second predetermined temperature near the boiling temperature. 4. When the temperature detecting means detects that the temperature has reached a third predetermined temperature which is higher than the first predetermined temperature, the on / off means for controlling the operation of the circulation means is operated for a predetermined time. The electric water heater according to claim 1, 2 or 3. 5. A time measuring means for measuring the drive time of the control means is provided, and the on / off means is activated each time the time measuring means measures a predetermined time. Electric water heater.