JP3144326B2 - 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 a method for heating a stored liquid.
The present invention relates to an electric water heater using a liquid pump used for keeping warm and tapping water.

[0002]

2. Description of the Related Art A conventional electric water heater of this type has a structure as shown in FIGS. That is, this kind of liquid pump 50 is a centrifugal impeller 51.
And had wing pieces 52 arranged radially. Hot water in the container 53 of the electric water heater is sucked into the center of the impeller 51, guided to the discharge port 54 in the outer peripheral direction, and guided to the tap 55. Also, a flow rate adjusting mechanism 57 is provided at the outlet of the tap hole 55 so that the amount of tap water can be adjusted.

[0003]

However, in such a conventional electric water heater, after the liquid is once boiled, the water is heated.
The temperature was kept at a predetermined temperature of about 5 ° C. However, in such an electric water heater, the tapping is adjusted by changing the voltage of the liquid pump. In order to adjust the amount of hot water, the motor is set to the maximum voltage, the hot water is adjusted by a regulating valve in a case provided at the outlet of the hot water path, or in recent years, as shown in FIG. As for the adjustment of the amount of hot water, there has been one that has two stages of adjustment, that is, large and small voltage.

[0004] In this case, the former configuration is complicated and increases the cost. In the latter configuration, when air bubbles are caught in the case of the liquid pump at the time of tapping a small amount of water, cavitation is caused, and the tapping of the bubbles prevents the tapping of the tap water.

[0005] Further, when trying to discharge hot water during or immediately after boiling with a pump, bubbles are generated in the pump case,
Since the gas is stirred and rotated by the impeller, bubbles grow further and fill the pump case, so that hot water in the container cannot be supplied and hot water cannot be discharged.

[0006] The reason is that boiling or hot water immediately after boiling contains fine bubbles. In other words, the bubbles grow when passing through the pump case, accumulate in the pump case, and the impeller idles due to the bubbles.

[0007] Further, even with a liquid pump type pump, when the amount of water is small, the discharge amount is reduced as compared with the full state, and it takes time to discharge. In the vicinity of the discharge amount and the supply amount in the full state,
The discharge amount was smaller than full water, making it an inconvenient electric water heater. It is an object of the present invention to solve such a problem and to provide an electric water heater capable of reliably supplying hot water.

[0008]

Means for Solving the Problems The present invention to solve the above problems, the inner container containing a liquid, and a liquid pump of the centrifugal pump type connected to the water guide port of the inner container, this
To the circuit that controls the liquid pump and the motor of the liquid pump
And means for switching the power supply to the positive and negative, when the outer peripheral portion of the suction port at the center and the rotation direction of the pump casing of a liquid pump and a tangential to the discharge port provided in the rotating liquid pump to the discharge direction Increases the discharge rate, and when the liquid pump rotates
When tapping through the discharge port to reduce the discharge amount
It is an electric kettle, characterized in that the rotational direction of the liquid pump and can be selected.

With the above configuration, the flow rate can be changed by changing the rotation direction with one pump without the need for an adjustment valve adjusting mechanism, and the amount of hot water can be realized with a simple configuration.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION
Connect the inner container containing the liquid and the water inlet of this inner container.
Centrifugal pump type liquid pump and this liquid pump
Control circuit and the power supply to the liquid pump motor.
Switching means, and the pump case of the liquid pump is provided.
Suction port at the center of the nozzle and tangential discharge at the outer periphery in the rotation direction
An outlet is provided, and when this liquid pump rotates in the
Output volume is large, and discharge volume is small when the liquid pump rotates in reverse.
So that when the hot water is discharged through the discharge port,
The turning direction can be selected .

Therefore, when rotating in the discharge direction, hot water is discharged at a normal discharge amount, and by rotating in the reverse direction, the amount of hot water can be reduced and the way of hot water can be adjusted.

According to a second aspect of the present invention, the angle of the impeller blades is inclined in the direction opposite to the discharge port from the central suction port toward the outer periphery, and the number of blades is two. . As a result, cavitation is prevented by minimizing the number of blades, and air bubbles in the case of the liquid pump can be discharged immediately after boiling to reliably discharge hot water.

According to a third aspect of the present invention, there is provided a boiling detecting means for detecting the boiling of the liquid in the container and a measuring means for measuring the time from the completion of the boiling. A voltage control means for the liquid pump is provided so that the voltage of the motor is set to almost the maximum voltage for an arbitrary time immediately after that, and then the hot water is supplied at a fixed normal voltage.

Therefore, before the impeller of the liquid pump idles, for example, when air bubbles are trapped in the pump case immediately after boiling, the voltage of the motor is increased to discharge the air bubbles, and the amount of hot water can be secured. .

The invention according to a fourth aspect of the present invention comprises a means for detecting a current value of the liquid pump and a control means for controlling an applied voltage, and controls a power supply voltage of the liquid pump in accordance with the current value to supply hot water. When the current value at the start of the operation is small, the voltage is increased, and when the current value is large, the liquid pump is controlled to decrease the voltage.

Therefore, when the current value of the motor is small, that is, when the amount of water is small, the voltage of the motor is increased to increase the amount of hot water, so that the discharge amount can be constant regardless of the amount of water in the container, and the stoppage of the hot water can be prevented. It can be prevented.

According to a fifth aspect of the present invention, after the rotating direction of the liquid pump is reversed for an arbitrary time at the time of tapping,
By rotating in the normal direction, air bubbles in the case of the liquid pump are released into the container, hot water in the container is supplied into the pump case, and hot water can be discharged without stopping. Things.

[0018] The invention according to claim 6 of the present invention comprises detecting means for detecting the water level in the container and control means for controlling the voltage of the liquid pump at the time of tapping, so that the voltage of the liquid pump is changed according to the water level. It was made.

Therefore, even with a small amount of water at a voltage corresponding to the amount of water, the amount of hot water is almost constant, and the same discharge amount as in a full state can be obtained.

[0020]

Embodiment 1 First, a first embodiment of the present invention will be described with reference to FIGS. As shown in the figure, the container 1 is a cylindrical container with a bottom and is provided inside the exterior body 2, and a heating element 3 is provided on the back side of the bottom surface 4 of the container 1. On the back side of the bottom surface of the container 1, a temperature detecting device 5 is mounted. This temperature detecting device 5
The temperature sensor 6 is mounted and fixed by a mounting spring 7 which presses and urges the bottom surface of the container 1.

Reference numeral 8 denotes a liquid pump of a centrifugal pump type, and the hot water in the container 1 is provided below the container 1. The liquid pump 8 is forcibly sent out from the water introduction port 1A in the container 1 through the suction port 10 by the discharge port 11, and is discharged from the tap hole 12. The liquid pump 8 includes a driving source 9 such as a motor.
Rotation of the suction port 10 and the discharge port 11 via magnetic transmission means.
Is transmitted to the impeller 13 in the pump case 13 having

Further, the drive-side case 16 and the pump case 13 are connected in the axial direction with the magnetically permeable partition wall 15 interposed therebetween. One drive side case 16 contains a magnetic material 1
7 and a drive plate 18 directly connected to the drive source. Further, the pump case 13 includes an impeller 14, and has a suction port 10 at the center of the front surface and a discharge port 11 at a part of the outer periphery. Also, the pump case 13
Constitutes part of the hot water path.

The impeller 14 is adapted to rotate on the outer peripheral surface of the fixed shaft 19, as shown in FIGS. That is, the impeller 13 body having a plurality of blades 14A radially formed on one side surface has a substantially cap-like shape, and has a ring-shaped magnetic storage space on the side opposite to the blade forming surface. The opening of the magnetic material storage space on the drive source 9 side is closed by a cap.

Reference numeral 20 denotes a magnetic material corresponding to the magnetic material on the driving side provided in the magnetic material storage space. In addition, the plurality of blades 14A are formed by wing pieces whose inner ends reach near the center. Reference numeral 21 denotes a control circuit having a microcomputer, which is provided with a switching circuit for controlling the rotation direction of the liquid pump. Reference numeral 22 denotes a rising pipe for raising hot water from the liquid pump. 23 is a check valve interposed in the water guide path, 24 is a lid of the container, and 25 is a knob for opening the lid. Reference numeral 26 denotes an operation board which is a hot-water supply display LED 2
7A, reboiler LED 27B and tap switch 28 for tap water
And a switch for reboil. Reference numeral 29 denotes a display unit having a tapping operation unit 29A and a reboiler operation unit 29B. The control circuit 21 controls energization to the heating element 3 by an electric signal from the temperature detecting device 5. FIG. 14 is an overall perspective view of the electric water heater of the present invention.

The operation of the above configuration will be described.
When a liquid is accommodated in the container 1 and energization is started, the heating element 3 is heated to heat the liquid in the container 1 and the container 1
The liquid temperature is controlled to a predetermined value by the temperature detecting device 5 mounted on the lower part.

Here, in the first embodiment, the rotation direction of the liquid pump 8 having the suction port 10, the discharge port 11 and the impeller 14 connected to the water introduction port 1A of the inner container 1 is changed by a changeover switch of a control circuit. The flow rate is adjusted by rotating in the discharge direction and in the direction opposite to the rotation in the discharge direction.

That is, generally, the rotation direction of the impeller 14 is rotated toward the water guide side to secure a discharge amount of about 40 to 50 mL / S. About 15-25m for reverse rotation
The tapping amount can be adjusted to the tapping amount of L / S. In the present invention, when the discharge amount is large, the rotation direction is used, and when the discharge amount is small, the rotation of the impeller 14 is set in the reverse direction to reduce the discharge amount.

At this time, the applied voltage is constant. Therefore, since the rotation speed is increased even with a small amount of discharge by setting the applied voltage constant, bubbles can be easily discharged.

Further, by changing the forward and reverse rotation voltages, the range of adjusting the amount of hot water can be further expanded.
FIG. 6 shows the display / operation unit of the present invention, in which a large amount of hot water and a small amount of hot water are displayed by an LED lamp 27 and a hot water button 29 is provided.

By setting a plurality of hot water switches,
Further, a plurality of types of hot water adjustment can be performed.

Embodiment 2 Next, a second embodiment of the present invention will be described with reference to FIGS. Reference numeral 13 denotes an impeller housed in the pump case 12, which is inclined from the suction port 10 toward the outer periphery in the direction opposite to the discharge port 11 side.

The impeller 14 has a structure in which the angle of the blade 14A is inclined from the central suction port 11 toward the outer periphery in the opposite direction to the discharge port 11 and the number of blades is two. Although the temperature is lowered, the suction of the hot water with few blades is smoothly performed, and the stirring of the air bubbles is also reduced, so that the air bubbles are efficiently discharged from the discharge port side before the air bubbles are filled in the pump case 13 and the hot water stops. Can be lost. In addition, the discharge amount is reduced by using two blades. In this case, the voltage is increased to increase the number of rotations, and a normal discharge amount is secured.

Embodiment 3 Next, a third embodiment of the present invention will be described with reference to FIG. Reference numeral 6 denotes a sensor for detecting the temperature of hot water in the container 1, which is attached to the bottom of the container. Reference numeral 5 denotes a control circuit having a microcomputer 5A and the like, having a boiling detecting means 5B for detecting the boiling of the liquid in the container, a measuring means 5C for measuring time, and a means 30 for controlling the voltage of the liquid pump. I have.

A boiling detecting means 5B for detecting the boiling of the liquid in the container 1, a means 5C for measuring the time after the detection of the boiling,
The means 30 for controlling the applied voltage of the motor 9 and the applied voltage of the hot water of the liquid pump 8 are set such that the applied voltage of the motor 9 is maximized for a few seconds immediately after boiling, and then the hot water is discharged at a normal voltage. is there.

For example, cavitation is likely to occur particularly immediately after boiling or about 5 to 6 minutes after boiling. Therefore, during this time, the voltage of the motor 9 is maximized for several seconds, and the normal voltage is applied after the bubbles in the liquid pump 8 are discharged. Thus, the hot water can be prevented from stopping and the amount of hot water can be secured.

Embodiment 4 Next, a fourth embodiment of the present invention will be described with reference to FIG. 31 is a means for detecting the current value of the liquid pump 8 and 32 is a control circuit for controlling the power supply voltage of the motor 9.

In this embodiment, when the current value of the liquid pump 8 is detected, a voltage is determined in advance in proportion to the current value by a control circuit having a microcomputer for determining a voltage according to the current value. It is programmed.

Therefore, when the current value at the start of tapping is small, the voltage is increased, and when the current value is large, the voltage is decreased. If the rated water volume is full, the pushing into the water inlet 9 is increased, the discharge amount is increased, and the current value is increased.

In particular, the reason why the current value of the pump decreases when the amount of water is small is that when the water level in the container is low, the water pressure in the suction port 10 of the liquid pump 8 is reduced and the discharge amount is reduced. is there.

Therefore, when the amount of water is small and the current value is small, the voltage is increased to increase the voltage applied to the liquid pump 8 and to apply it to the motor 9 to increase the discharge amount.

Embodiment 5 Next, a fifth embodiment of the present invention will be described with reference to FIG. As shown in the figure, the liquid pump 8 is the same as in the first embodiment. The liquid pump 8 has a suction port 10 and a discharge port 1
The impeller 14 is contained in a pump case 13 provided with the first impeller 14. With the above configuration, the liquid pump rotates in the normal direction after the rotation direction of the liquid pump is first reversed at the time of tapping.

Therefore, the air bubbles accumulated in the pump case 13 are discharged to the container side and the discharge port side in order to rotate the impeller 14 in the reverse direction and then set the impeller 14 in the normal rotation direction.

Thus, the hot water is easily stopped immediately after boiling, but air bubbles can be discharged from the beginning to the end to discharge bubbles.

Embodiment 6 Next, a sixth embodiment of the present invention will be described with reference to FIGS. Numeral 34 denotes a detecting means for detecting a water level in the container 1, for example, an electrode is provided inside the pipe as a means for detecting the water level, and a difference in capacitance due to a potential difference between the water level and the electrode is determined. Reference numeral 35 denotes a control circuit having a microcomputer. The control circuit 36 controls the voltage of the liquid pump 8 at the time of tapping, and controls the voltage of the liquid pump 8 according to the water level. For example, when the water is full, the voltage is reduced and the hot water is discharged. When the amount of water decreases, the amount of water is detected by, for example, an output from a water level detecting device 34A provided in a water pipe by a detecting means, processed by the control device, and the voltage is set. The voltage is supplied to the driving power supply 9 of the liquid pump 8 to drive the liquid pump 8.

When the amount of water is small, it is set so that the hot water is discharged by increasing the voltage. Therefore, when the amount of water is small, a discharge amount equivalent to full water can be secured. Usability is also improved.

[0046]

As is clear from the above description, according to the first aspect of the present invention, no adjusting valve adjusting mechanism is required.
By changing the rotation direction with one pump, the flow rate can be changed, and the amount of hot water can be realized with a simple configuration.

According to the second aspect of the present invention, since the number of blades is set to two and the blade is inclined in the opposite direction from the suction port toward the outer periphery, tapping by foam bubble in the pump case immediately after boiling. The stop can be prevented.

According to the third aspect of the present invention, since the maximum voltage of the motor is set at any time immediately after the boiling, cavitation due to the bite of the foam immediately after the boiling can be prevented, and the tapping water immediately after the boiling can be ensured. .

According to the present invention, when the current value of the pump is small, the voltage of the motor of the pump is increased,
It is an object of the present invention to provide an easy-to-use water heater which can always discharge a fixed amount by correcting the amount of hot water.

According to the fifth aspect of the present invention, since the start of discharge is rotated in the direction opposite to the discharge direction, bubbles in the pump case are first discharged into the container, and then tapping is started. You can take a hot water without doing it.

According to the sixth aspect of the present invention, since the tapping voltage is determined according to the water level in the container, it is possible to discharge in accordance with the amount of water. Since the difference is corrected, an easy-to-use electric water heater can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electric water heater according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway side view of the liquid pump of the electric water heater.

FIG. 3 is a plan view of a liquid pump of the electric water heater.

FIG. 4 is a plan view of the impeller of the liquid pump of the electric water heater.

FIG. 5 is a cross-sectional view of the impeller of the liquid pump of the electric water heater.

FIG. 6 is a diagram showing an operation display unit of the electric water heater.

FIG. 7 is a plan view of an impeller of a liquid pump of an electric water heater according to a second embodiment of the present invention.

FIG. 8 is a sectional view of an impeller of the liquid pump of the electric water heater.

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

FIG. 10 is a circuit block diagram of an electric water heater according to a fourth embodiment of the present invention.

FIG. 11 is a sectional view of an electric water heater according to a fifth embodiment of the present invention.

FIG. 12 is a sectional view of an electric water heater according to a sixth embodiment of the present invention.

FIG. 13 is a circuit block diagram of the electric water heater.

FIG. 14 is a perspective view of the electric water heater of the present invention.

FIG. 15A is a plan view of a liquid pump of a conventional electric water heater. FIG. 15B is a cross-sectional view of the liquid pump of the electric water heater.

FIG. 16 is a partially cutaway side view of a liquid pump of a conventional electric water heater.

FIG. 17 is a sectional view of a conventional electric water heater.

FIG. 18 is a diagram showing an operation display unit of a conventional electric water heater.

[Explanation of symbols]

 Reference Signs List 1 container 3 heating element 5 temperature detecting device 6 temperature sensor 8 liquid pump 10 suction port 11 discharge port 12 tap hole 13 impeller 20, 35 control circuit 29A tapping operation section 5A boiling detecting means 5B time measuring means 30 drive voltage applying means 31 current Value detection means 32 control means 34 water level detection means 36 voltage control means

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁷ Identification code FI A47J 27/00 109 A47J 27/00 109Z

Claims (6)

(57) [Claims] And 1. A inner container containing the liquid, and a liquid pump of the centrifugal pump type connected to the water guide port of the inner container, this
To the circuit that controls the liquid pump and the motor of the liquid pump
And means for switching the power supply to the positive and negative, when the outer peripheral portion of the suction port at the center and the rotation direction of the pump casing of a liquid pump and a tangential to the discharge port provided in the rotating liquid pump to the discharge direction Increases the discharge rate, and when the liquid pump rotates
When tapping through the discharge port to reduce the discharge amount
Electric water heater that can select the rotation direction of the liquid pump . 2. An inner container for containing a liquid, and an inner container for the inner container.
A centrifugal pump type liquid pump connected to the water inlet
Suction port and rotation direction in the center of the pump case of the liquid pump
A discharge port is provided on the outer periphery of the
Can rotate in the discharge direction and in the opposite direction to the discharge direction.
An electric water heater in which the angle of inclination of the impeller blades of the liquid pump is inclined in the direction opposite to the discharge port from the central suction port toward the outer periphery, and the number of blades is two. 3. An inner container for containing a liquid, and an inner container for the inner container.
A centrifugal pump type liquid pump connected to the water inlet
Suction port and rotation direction in the center of the pump case of the liquid pump
A discharge port is provided on the outer periphery of the
Can rotate in the discharge direction and in the opposite direction to the discharge direction.
And a means for detecting the boiling of the liquid in the container, a measuring means for measuring the time after the detection of the boiling, and a means for controlling the voltage applied to the motor. An electric water heater or an inner container containing liquid, in which the motor is set to almost the maximum voltage for a few seconds from an arbitrary time to the next time and then the tap water is supplied at a normal tapping voltage .
And a centrifugal pump type liquid connected to the water inlet of this inner container.
Body pump and the center of the pump case of this liquid pump
A suction port and a discharge port are provided on the outer periphery in the rotation direction.
Rotate the pump in the discharge direction and reverse the discharge direction
And the inclination of the impeller blades of the liquid pump
From the central suction port toward the outer periphery
Incline in the direction opposite to the mouth and make two blades inside the container
Boiling detection means for detecting the boiling of the liquid ,
Measuring means for measuring time and controlling the applied voltage to the motor
Means for controlling the voltage applied to the hot water from the liquid pump to the boiling point.
After that, for a few seconds between any time, the motor's almost maximum voltage
Then, an electric water heater that is made to supply water at a normal supply voltage . 4. An inner container for containing a liquid, and an inner container for the inner container.
A centrifugal pump type liquid pump connected to the water inlet
Suction port and rotation direction in the center of the pump case of the liquid pump
A discharge port is provided on the outer periphery of the
Can rotate in the discharge direction and in the opposite direction to the discharge direction.
And, a control means for controlling the means and the applied voltage to detect the current value of the liquid pump, electric kettle for controlling the power supply voltage of the liquid pump in accordance with the current value. 5. An inner container for containing a liquid, and an inner container for the inner container.
A centrifugal pump type liquid pump connected to the water inlet
Suction port and rotation direction in the center of the pump case of the liquid pump
A discharge port is provided on the outer periphery of the
Can rotate in the discharge direction and in the opposite direction to the discharge direction.
And, after the rotation direction of the liquid pump is reversed between any time during tapping, electrical Yunie <br/> However instrument which has to be rotating in the normal direction. 6. A detecting device for detecting a water level in a container, and a controlling device for controlling a voltage of a liquid pump at the time of tapping,
5. The electric water heater according to claim 4, wherein the voltage of the liquid pump is changed according to the water level.