JPH06133865A - Electric hot-water heater - Google Patents

Abstract

PURPOSE:To pump out a liquid contained in a vessel by power, even if a power source is disconnected by being detached from a power source plug socket. CONSTITUTION:A capacitor 36 and a charging means 50 are provided, and a control circuit 13 heats a liquid 51 contained in a vessel 2 by a heating source 4 and a commercial AC power source 14, completes charging of a power accumulating means 36 executed by a charging circuit 50 during a term from the start of heating till boiling up, drives a motor 10 by accumulated power of the power accumulating means 3 in accordance with a pumping-out operation of an operating control 11 after boiling, and executes control so as to discharge the liquid 51 by rotating a motor-driven pump 7.

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 water contained in a container.
When the power supply is cut off, for example, it is related to measures against power failure.

[0002]

2. Description of the Related Art In recent years, electric water heaters have been favored as household items that can easily heat and keep water warm, and have been devised to be easy to use, such as discharging water in a container using an electric pump. The issue is usability during a power failure.

A conventional electric water heater will be described below with reference to the drawings. FIG. 5 is a partial cross-sectional block diagram showing the configuration of a conventional electric water heater. In the figure, a main body container 1 is provided with a container 2 having an upper surface opening for containing a liquid 51,
A lid 3 that covers the upper portion of the container 2 is arranged on the upper portion of the main body container 1. A heating source 4 for heating the liquid 51 inside the container 2 and a temperature sensor 5 for detecting the temperature of the liquid inside the container 2 are arranged at the outer lower portion of the container 2. A discharge port 6 for the liquid 51 is provided in the vicinity of the bottom of the container 2, a water channel is formed by a water conduit 8 via an electric pump 7, and an external outlet 9 is provided at the tip thereof. Electric pump 7 is motor 1
Driven by 0, the liquid 51 is ejected from the external outlet 9. On the upper part of the main body container 1, an operation knob 11 for pumping out the liquid 51 in the container 2 and a switch 12 for connecting or disconnecting by the operation are provided. Switch 1
The switching signal of 2 and the signal of the temperature sensor 5 are the control circuit 13
Input to the control circuit 13 and the commercial AC power supply 14
Is entered. Although the control circuit 13 is stored inside the main body container 1, it is shown outside in FIG. 5 for simplicity of explanation.

To explain the operation in the above configuration, the control circuit 13 supplies electric power to the heating source 4 from the commercial AC power source 14, controls the heating of the container 2 while referring to the liquid temperature detected by the temperature sensor 5, and boils. And controlling the heat retention operation. Operation knob 11 for the user to pump out the liquid 51
When is operated, the connection signal of the switch 12 changes to the control circuit 13
Control circuit 13 causes electric motor 7 to rotate electric pump 7, and liquid 51 is discharged from external outlet 9. The commercial AC power supply 14 is supplied by a power cord (not shown) connected to a power outlet (not shown). The power cord is a connecting device (not shown) provided in the main body container 1. It is detachably attached.

[0005]

In such a conventional electric water heater, when the power outlet is removed from the main body container, the electric power of the electric pump is cut off and water cannot be discharged even if the knob is operated. There was a similar problem when used in a place where a power outlet was not installed.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an electric water heater capable of pumping out hot water even when the power outlet is removed or even in a place where the power outlet is not installed.

[0007]

In order to solve the above-mentioned problems, the present invention comprises a container for containing a liquid, a heater for heating and boiling the liquid with a commercial AC power source, and a heater for retaining heat. In the electric water heater, a power source, a power source, an operating unit for an operator to input an instruction to pump out the liquid, a discharging unit for discharging the liquid out of the container, and a control unit for controlling the entire operation. And charging means for charging the power storage element with a commercial AC power supply,
The control means completes the charging of the power storage element during the time from the start of heating the liquid to the boiling, and discharges the stored power of the power storage element in response to the pumping operation in the operation unit. It is an electric water heater which controls the means to drive the means to discharge the liquid in the container.

[0008]

According to the present invention, in the above structure, the control circuit charges the power storage element by the charging means and completes it from the time when the heating source starts to be energized to the time when it boils. Control to drive.

[0009]

【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 an embodiment of the present invention. The same components as those of the conventional example are given the same numbers and their explanations are omitted.

The constitutional requirements of the electric water heater of the embodiment of the present invention differing from the conventional example are that the capacitor 36 as a power storage element is used.
And charging means 50 are newly provided, and the control circuit 13 controls the charging means 50 to charge the capacitor 36, and controls the motor 10 to be driven by the electric power stored in the capacitor 36. . In FIG. 1, the control circuit 13, the capacitor 36, and the charging means 50.
Is disposed inside the main body container 1, but is drawn out for the sake of explanation. FIG. 2 is an electric circuit diagram showing the configuration of the electric water heater of the embodiment of the present invention. In FIG. 2, a heating source 4 having a high-temperature heating heater 4a and a low-temperature heat-retaining heater 4b, a motor 10 for discharging the liquid 51 in the container 2, a condenser 36 that is a power storage means, The charging means 50, the switch 12 that is opened and closed by the operation knob 11, and the commercial AC power supply 14 are connected to the control circuit 13. The control circuit 13 is driven by a circuit drive power supply (not shown) that inputs the commercial AC power supply 14 and outputs the DC drive voltage Vdd.

The mutual relationship and operation of the above components will be described below. In the control means 13, a microcomputer (hereinafter referred to as a microcomputer) 27 has resistors 22 and 2.
The transistors 19, 21 and 25 are electrically connected through the relays 3 and 26, and the relay coil 15b and the relay coil 16 are respectively connected.
b, the thyristor 17 is energized, the heating heater 4a is connected to the commercial AC power source 14 by the relay contact 15a, and the heat retention heater 4b is connected to the commercial AC power source 14 by the relay contact 16a and the thyristor 17 to energize. When the transistor 19 is turned on, the relay contact 16a is switched from the terminal a to the terminal b and the contact 16c is opened by the exciting action of the relay coil 16b. When the transistor 21 is turned on, the relay coil 1
The relay contact 15a is brought into conduction by the exciting action of 5b, and a heating current flows through the heater 4a for heating. When the transistor 25 is turned on, the thyristor 17 is turned on via the resistor 24, and a heat retention current flows through the heat retention heater 4b. The diode 18 and the diode 20 are respectively the transistor 1
9 and a diode for absorbing a surge voltage when the transistor 21 is opened.

Further, an on / off signal of the transistor portion 29a of the photocoupler 29 and a temperature signal from the temperature sensor 5 composed of a thermistor and the resistor 30 are used as the microcomputer 2
Input to 7. When the transistor 19 is off,
The relay contact 16a is connected to the terminal B, and the contact 16
c opens. At this time, the diodes 31, 32, 3
A charging means 50 composed of a diode bridge composed of 3, 34 inputs an AC voltage from the commercial AC power supply 14 via the heat-retaining heater 4b, rectifies it and rectifies it.
To charge. When the charging voltage of the capacitor 36 rises and the zener diode 35 reaches the zener voltage, zener current flows to the diode part 29b of the photocoupler 29, and the light emitting action of the zener current causes the transistor part 29a of the photocoupler to conduct.

When the operating knob 11 is pushed, the contact of the switch 12 is made conductive, and the current due to the electric charge stored in the capacitor 36 flows to the motor 10 through the voltage stabilizing circuit composed of the transistor 39 and the zener diode 40. The electric pump 7 is driven. At this time, the motor 10
The voltage v ₁ applied between the terminals of the zener diode 4
It depends on the Zener voltage of 0. Therefore, the voltage on capacitor 36 needs to be higher than v ₁ . The resistor 38 is a current limiting resistor.

FIG. 3 is a flow chart showing the operation of the electric water heater of the present invention. When the electric water heater is connected to the commercial AC power supply 14 in step 1, the process proceeds to step 2 in which the microcomputer 27 makes the transistor 21 conductive and supplies AC power to the heating heater 4a through the relay contact 15a to heat it. At the same time, the transistor 19 is turned on, the relay contact 16a is connected to the terminal B, and the input ends of the diode bridges 31 to 34 are connected to the commercial AC power source 14 via the heat retention heater 4b. The DC voltage rectified by the charging means 50 by the diode bridge starts charging the capacitor 36. When the voltage of the capacitor 36 increases with the progress of charging and reaches the zener voltage of the zener diode 35 in step 3, the zener current flows through the diode part 29b of the photocoupler 29, so that the transistor part 29a of the photocoupler 29 becomes conductive. The voltage drop of the collector is input to the microcomputer 27 as a signal. Now, assume that charging is completed when the voltage of the capacitor 36 reaches a predetermined voltage determined by the zener voltage of the zener diode 35.

When the microcomputer 27 applies the ON signal of the photocoupler 29 as a signal indicating the completion of charging in step 4, the transistor 19 becomes non-conductive and the relay contact 16a is switched to the terminal a, and the relay contact 16c is connected. . Therefore, the charging means 50 is disconnected from the commercial AC power supply 14 to stop the charging of the capacitor 36, and
The capacitor 36 is connected to the switch 12. In step 4, the charging is completed before the liquid 51 in the container 2 boils. Next, in step 5, the transistor 25
Is conducted to bring the thyristor 17 into conduction, and the thermal power of the heat retention heater 4b is also involved in heating.

Next, in step 6, the temperature of the liquid is checked by the temperature sensor 5, and when it is detected that the liquid temperature has risen due to the progress of heating, the process proceeds to step 7, and the transistor 21 and the transistor 25 are used. Are made non-conductive to open the relay contact 15a to stop the energization of the heater 4a for heating, and to make the relay contact 16a
The a is switched to the contact a and the heater 4b for heat retention is cut off from the charging circuit. At this stage, the heating is stopped and the heat retaining operation is started. In step 8, when the user pushes the operation knob 11 to request pumping, the switch 12 is connected,
In step 11, the charge of the capacitor 36 flows to the motor 10 via the transistor 39, and the rotation thereof causes the electric pump 7 to discharge the liquid 51. If the user does not press the operation knob 11, the process proceeds to step 9 to constantly check the liquid temperature, and if the liquid temperature is not lower than the predetermined heat retention temperature, the process returns to step 7 and the heater is kept open. For example, the process proceeds to step 10 to turn on the transistor 25, and the thyristor 17 is used to heat the heater 4b.
Is energized to heat, and the process returns to step 9 to check the temperature. The boiling of water can be detected when the temperature rise value per unit time is always detected and the temperature rise value becomes equal to or lower than a predetermined temperature. In addition, the capacitor 36
When the charge is insufficient to reach the predetermined voltage, the relay contact 16c remains open and the motor 10 does not operate. By the above operation, the heat retention operation continues unless the commercial AC power supply 14 is cut off, and the user can pump out the liquid 51 at any time during that time.

When the commercial AC power supply 14 is disconnected, the drive voltage Vdd of the control circuit 13 disappears and the control is stopped. At this time, the transistor 19 also becomes non-conductive, so the relay contact 16a is connected to the terminal a. The contact 16c is in the connected state, and when the switch 12 is connected by operating the operation knob 11, the electric charge accumulated in the capacitor 36 causes the motor 10 to rotate, and the electric pump 7 can pump out the liquid 51.

The conditions for completing the charging before boiling water will be described below. FIG. 4 is a charge / discharge characteristic diagram of the capacitor 36 in the electric water heater of the first embodiment of the present invention. In FIG. 4, the time from the start of heating the water injected into the container 2 to the boiling state is set to t _2, and during this time, the charging current flows through the condenser 36 through the heat-retaining heater 4b and charging is just performed. Let's finish. When charging is completed at time t ₂ and water is immediately pumped out and the time required to discharge all the water is t ₃ , the time (t ₂
The charge amount of the capacitor 36 at + t ₃ ) is (C ₀ · v
_2- I · t ₃ ).

At this time, the motor 10 has a transistor 3
Since the voltage is supplied through the voltage stabilizing circuit composed of 9 and the Zener diode 40, the voltage of the capacitor 36 needs to be equal to or higher than the driving voltage v _{1 of the} motor. Therefore, the following relationship holds.

(C ₀ · v ₂ −I · t ₃ )〉 C ₀ · v ₁ That is, (C ₀ · v ₂ − (v ₁ / r ₁ ) · t ₃ > C ₀ · v ₁ C ₀ · v ₂ 〉 C ₀ · v ₁ + (v ₁ / r ₁ ) · t ₃ v ₂ 〉 v ₁ + (v ₁ · t ₃ ) / (C ₀ · r ₁ ), where v ₁ : secures stable motor operation Minimum drive voltage r ₃ : Motor operating time C ₀ : Capacitor capacitance r ₁ : Motor input impedance On the other hand, the voltage v ₂ is determined by the function f (t ₂ , R), where R: heat retention Resistance value of heater t ₂ : Time until water is in a boiling state Therefore, f (t ₂ , R ₁ )〉 v ₁ + (v ₁ · T ₃ ) /
Resistance value R of the heat-retaining heater so that (C ₀ · r ₁ ) is satisfied
Should be decided.

As described above, according to the electric water heater of the present embodiment, the condenser 3 which is electric power storage means for storing electric power.
6 and charging means 5 for rectifying and charging the commercial AC power supply 14
0, the control means 13 completes charging until the water is heated to boiling and the electric power accumulated in the condenser 36 is controlled to drive the motor 10 for the electric pump after the boiling. Water can be pumped out even if the power supply 14 is cut off. Further, since the capacitor 36 is charged during a relatively long time until the water boils, there is a margin in the charging time, and therefore, the current can be charged with a current smaller than the drive current of the motor 10, and the drive current of the motor 10 can be reduced. It can be charged with a small current even when it is large.

In the embodiment, the heater 4b for heat retention is also provided.
Is used as a series resistor for voltage drop of charging, and its heat generation is used as a part of heating. Therefore, the resistor for voltage drop is not required, and the heat generation can be used for heating.

Further, in the embodiment, by using the capacitor 36 for accumulating the electric charge as the electric power accumulating element,
There is no concern about the life of charge and discharge unlike the element using chemical change.

(Embodiment 2) An electric water heater according to a second embodiment of the present invention will be described below with reference to the drawings. The components of the electric water heater of the present embodiment are the same as those of the electric water heater of the first embodiment shown in FIGS. 1 and 2, and detailed description thereof will be omitted. The present embodiment is another example in which a sufficient charge amount for discharging all the full water in the container is set so as to be completed during the time until boiling.

In FIG. 4, a charging current flows through the capacitor 36 through the heat-retaining heater 4b, and when the time t ₀ is reached, a Zener current flows through the Zener diode 35 and the charging is stopped. At this time, assuming that the inter-terminal voltage of the capacitor 36 is v ₀ and the electrostatic capacitance is C ₀ , the charge amount Q ₀ of the capacitor 36 is Q ₀ = C ₀ · v ₀ . If the drive voltage of the motor 10 is v ₁ and the input impedance is r ₁ , the current I flowing through the motor 10 is I = v ₁ / r ₁ . And i ₀ "I, the time required to discharge by all filled in the container 2 water motor 10 as t ₁ relative to Tsu current value i ₀ of the Zener diode 40 is a current value I flowing through the motor 10, The amount of charge Q ₁ flowing through the motor 10 during the time t ₁ is Q ₁ = I · t ₁ = (v ₁ / r ₁ ) · t ₁ .

As is clear from the above conditions, the electrostatic capacitance C ₀ of the capacitor 36 should satisfy the following conditions.

Q ₀ > Q ₁ That is, C ₀ · v ₀ > (v ₁ / r ₁ ) · t ₁ Therefore, C ₀ > (v ₁ · t ₁ ) / (v ₁ · r ₁ ) The capacitance C ₀ of the capacitor 36 for completing the charge before boiling can be determined from the values v ₁ , t ₁ , r ₁ determined by the characteristics of the motor 10 and the charging voltage v _{0 of the} capacitor. it can.

As described above, according to the electric water heater of the present embodiment, it is possible to charge and secure sufficient electric power to discharge all the water during the time until the water is boiled.

[0029]

As is apparent from the above embodiments, the present invention provides a heating source having a container for containing a liquid, a heater for heating and boiling the liquid with a commercial AC power source, and a heat retaining heater for retaining the temperature. In the electric water heater provided with an operation unit for an operator to input an instruction to pump out the liquid, a discharging unit for discharging the liquid out of the container, and a control unit for controlling the entire operation, a power storage element, A charging means for charging the power storage element with a commercial AC power source is provided, and the control means completes the charging of the power storage element during the time from the start of heating of the liquid to the boiling point, and the operation unit. By discharging the liquid in the container by driving the discharging means by the stored power of the power storage element in response to the pumping operation in Also, it is possible to pump all the water after boiling. Further, when a capacitor is used for the power storage element, there is an effect that it is not necessary to worry about the charge / discharge life.

[Brief description of drawings]

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

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

FIG. 3 is a flowchart showing the operation of the electric water heater of the first and second embodiments of the present invention.

FIG. 4 is a charge / discharge characteristic diagram of the power storage element in the electric water heater of the first and second embodiments of the present invention.

FIG. 5 is a partial cross-sectional block diagram showing the configuration of a conventional electric water heater.

[Explanation of symbols]

 2 Container 4 Heating Source 4a Heating Heater 4b Insulation Heater 7 Electric Pump (Discharging Means) 10 Motor (Discharging Means) 11 Operating Knob (Operating Unit) 12 Switch (Operating Unit) 13 Control Circuit (Controlling Means) 14 Commercial AC Power Supply 36 Power Storage Element 50 Charging Means 51 Liquid

Claims (4)

[Claims] 1. A heating source having a container for containing a liquid, a heater for heating and boiling the liquid with a commercial AC power source, and a heater for retaining heat, and an operation for an operator to input an instruction to pump out the liquid. In an electric water heater equipped with a portion, a discharging means for discharging the liquid to the outside of the container, and a control means for controlling the entire operation, a power storage element and a charging means for charging the power storage element with a commercial AC power source. And, the control means completes the charging of the power storage element during the time from the start of heating the liquid to the boiling,
An electric water heater that controls the discharge means to discharge the liquid in the container by the stored power of the power storage element in response to the pumping operation in the operation unit. 2. The electric water heater according to claim 1, wherein the electric power supplied to the electric power storage element by the charging means is obtained from the commercial AC power source through the heater. 3. The electric water heater according to claim 1, wherein the electric power storage element is a capacitor for storing electric charges. 4. The electric water heater according to any one of claims 1 to 3, wherein the stored electric power amount is set to be an electric power amount capable of discharging all of the liquid filled in the container.