JP3525902B2 - 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 used in general households.

[0002]

2. Description of the Related Art In recent years, in electric water heaters, products capable of supplying hot water with an electric pump have become mainstream. In order to further improve the usability of this electric water heater type electric water heater, products having a cordless hot water discharge function that can be electrically heated by a backup power supply even in a place without a commercial power supply have been released.

[0003]

However, in the conventional electric water heater having the cordless hot water discharge function, the boosting operation is performed to drive the electric pump regardless of the remaining level of the backup power source in order to ensure hot water discharge performance. When the residual voltage level is small, a large current flows in the primary side circuit, which overloads the primary side circuit components, or an expensive configuration using a large rated component that can withstand the large current.

[0004]

In order to solve the above problems, the present invention provides a container for containing a liquid, a commercial power supply means as an input section of a commercial power supply, and a liquid in the container to be discharged from the container. A hot water discharging unit including an electric pump and a hot water discharging switch, a backup power source for supplying power to the device when the commercial power source is not input from the commercial power source supplying unit, and a boosting unit for boosting the backup power source to supply power to the electric pump. And the remaining energy of the backup power supply
And a control means for changing the output to the electric pump according to the detected residual energy level and for stopping the boosting operation when the residual energy falls below a predetermined level.

With the above-mentioned structure, the hot water discharge performance during cordless dressing can be improved at a low cost without overloading the circuit components.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is a container for containing a liquid, an electric pump for discharging the liquid from the container, and a backup power supply for supplying power to equipment when commercial power is not input. A boosting means for boosting the backup power supply to supply power to the electric pump; a detection means for detecting the remaining energy of the backup power supply; and a control means for controlling the driving of the electric pump. The means stops the boosting operation of the boosting means when the residual energy detected by the detecting means becomes equal to or lower than a predetermined level, and supplies the backup power supply to the electric pump without boosting it, thereby eliminating the commercial power supply. The hot water supply operation can be performed in this state, and when the remaining energy of the backup power supply decreases, excessive current does not flow to the booster. In addition, by supplying the backup power supply to the electric pump without boosting the pressure, it is possible to provide a high-quality cordless hot water electric water heater that is easy to use and can eliminate the inconvenience of suddenly becoming unable to operate hot water. it can.

According to a second aspect of the present invention, the control means according to the first aspect causes the electric pump to operate when the residual energy of the backup power source detected by the detection means falls below a second predetermined level lower than a predetermined level. By not supplying the backup power supply, the control circuit operation is stopped when the remaining energy of the backup power supply falls below the limit that does not cause the malfunction of the control circuit, thus preventing equipment failure or unsafe operation. be able to.

According to a third aspect of the present invention, a container for containing a liquid, an electric pump for discharging the liquid from the container, a backup power supply for supplying power to equipment when a commercial power supply is not input, and the backup Boosting means for boosting the power supply to supply power to the electric pump, detecting means for detecting the remaining energy of the backup power supply, and changing the boosting level by the boosting means according to the remaining energy level detected by the detecting means. When the residual energy of the backup power supply is reduced, the voltage supplied to the electric pump is reduced in a plurality of steps or gradually so as not to give an excessive current or voltage to the boosting means. Therefore, it is possible to suppress the extent to which sudden hot water discharge becomes impossible or the amount of hot spring water drastically decreases. It is possible to provide a user-friendly electric kettle with less quality.

The invention according to claim 4 is particularly characterized by claim 3.
The control means described in (1) reduces the boosting level by the boosting means in response to a decrease in the residual energy level detected by the detecting means, and stops the boosting operation of the boosting means when the residual energy becomes equal to or lower than a predetermined level, and a backup power source. By supplying the electric power to the electric pump without boosting it, the time when hot water can be supplied by the backup power supply does not cause the user to feel an unnatural decrease in the amount of hot water supply, and an excessive load is applied to the parts of the boosting means. It is possible to provide an electric water heater that can be lengthened without a need.

The invention according to claim 5 is particularly provided with a notifying means for making a visual or audible notification, and the control circuit is such that the residual energy is below a predetermined level and the electric pump is not boosted by the backup power supply. When it is supplied to, by making the notification corresponding to the notification means,
Since the user can be urged to charge the backup power supply before the hot water supply operation becomes infeasible, an electric water heater that can reduce the chance of suddenly being unable to perform hot water supply operation without connecting to the commercial power supply Can be provided.

[0011]

(Embodiment 1) A first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, a container 2 for accommodating water having an upper surface opening is provided in a main body 1, and a lid 3 for covering an upper portion of the container 2 is arranged. Further, a heating source 4 for heating the water in the container 2, a temperature sensor 5 for detecting the water temperature in the container 2, an electric pump 7 for guiding the hot water in the container 2 to the outside from a discharge port 8, and an electric motor A motor 6 serving as a drive source of the pump 7 has a commercial power supply means 9 for inputting commercial power to the lower side.
A backup power supply 10 that serves as a power supply for the equipment when there is no commercial power input is provided on the side, and a hot water discharge switch 12 and a hot water discharge lock release switch 11 which are one component of the hot water discharge means that can be easily operated by the user. ing.

Furthermore, 13 is a boosting means for supplying power to the motor 6 with the backup power source 10 as an input,
Reference numeral 14 is a detection means for detecting the residual energy of the backup power supply 10, 16 is a motor drive means for driving the motor 6, and 15 is a signal from the commercial power supply means 9, the hot water release lock switch 11, and the detection means 14. It is a control unit that receives an input and outputs a signal to the boosting unit 13 and the motor driving unit 16.

FIG. 2 shows a control circuit for the electric water heater having the configuration shown in FIG.

In FIG. 2, the commercial power supply 17 supplies power to the control circuit via a magnet type connector 9 which is a commercial power supply means, and a rectifier circuit 18 and a transformer circuit 1 are provided.
9, a backflow preventing diode 20 and a regulator 21 are input to the microcomputer 15a which is a control means, and the output of the diode 20 (hereinafter referred to as Vu power source) is the hot water switch 12 , And is also connected to the control IC 13c, which is one component of the motor 6 and the boosting means 13, through the transistor 16a which is the motor driving means.

Each of 13a to 13j is one component of the boosting means 13 which boosts the backup power source 10 to a Vu power source. 13a is an input smoothing capacitor, 13f
Is an output smoothing capacitor, 13b is a choke coil, 1
3d is a switching transistor and 13e is a diode. 13c is a control IC, a Vu power source is a resistor 13g,
By inputting the reference voltage obtained by dividing by 13h, the switching duty of the transistor 13d or the boosting ratio of the boosting means 14 is determined and controlled.

The control means 15 includes respective control blocks 15a to 15d, and the fact that the commercial power source 14 is supplied from the magnet type connector 9 is configured in the microcomputer 15a via the current limiting resistor 23. When recognized by the power source recognition device 15d, the central control chamber 15b controls the heating source 4 based on the signal from the temperature sensor 5 (the control circuit configuration of the temperature sensor 5 and the heating source 4 is not shown in FIG. 2). . When the commercial power supply 17 is supplied, the central control chamber 15b receives the signal input from the hot water discharge lock release switch 11 and the resistor 22 and drives the motor driving transistor 16a via the resistor 16b. . Reference numeral 12 denotes a hot water discharge switch which can be easily operated by the user. When the hot water discharge switch 12 is turned on while the transistor 16a is driven, the motor 6 is driven and the electric pump 7 directly connected to the motor causes the internal hot water inside the container to move. Hot water can be discharged to the outside.

Next, when the power recognizing device 15d recognizes that the commercial power is not supplied, the micro computer
The switch 15a is in a state of waiting for a signal input from the hot water release lock release switch 11. At this time, the microcomputer 15a
The power is supplied from the backup power supply without boosting. At this time, the switching operation by the control IC 13c (ON / OFF control of the transistor 13d) is performed by the central control room 15
b is stopped by outputting a stop signal via the resistor 13j. (Hereafter, this operating state is referred to as backup mode). When a signal is input from the hot water release lock release switch 11 while the device is in the backup mode, an operation start signal is output from the central control room 15b to the control IC 13c via the resistor 13j, and the switching transistor 1
The switching operation of 3d, that is, the boosting operation of the backup power supply 10 by the boosting means 13 is started. The output (Vu power supply) of the step-up means 13 during the step-up operation is fed back to the control IC in the form of voltage division of the resistor 13g and the resistor 13h, so that the output is always a constant voltage regardless of the change of the input voltage. Controls the switching operation of the transistor 13d. (Transistor 1 when output drop is detected
3d off, transistor 13d on when output rise is detected, on / off control so that voltage across resistor 13h becomes constant).

When the hot water discharge lock release switch 11 is input, the boosting operation described above is performed, and then the transistor 1
6a is a resistor 16 by a microcomputer 15a.
When the hot water outlet switch 12 is pressed within a predetermined time T1 (for example, 10 seconds) previously turned on by the microcomputer 15a by the microcomputer 15a, the motor operates to discharge the hot water in the container to the outside. it can. When the predetermined time T1 or more has elapsed, the device shifts to the backup mode again.

During boosting operation, input voltage Vin and input current I
Assuming in, output voltage Vout, output current Iout, and efficiency η, in general, (Vout) * (Iout) = η * (Vin) * (Ii
n), and as is clear from the above equation, a constant output (Vou
t) * (Iout), the input current, that is, the choke coil 13b and the transistor 1 is reduced each time the input voltage decreases (remaining energy of the backup power supply 10).
The current flowing through 3d increases. In the present invention, the detection means 1
The remaining energy level (charge voltage in this case) of the backup power source detected by the resistors 14a and 14b of No. 4 is recognized by the AD converter 15c in the microcomputer 15a, and the level is predetermined in the microcomputer 15a. When a predetermined level (denoted by θ1) is reached, a boost operation stop signal is sent to the control IC via the resistor 13j.
Output to prevent the input current from increasing.

As described above, according to the first embodiment, it is possible to provide an electric water heater having a high quality and long-life cordless hot water discharge function in which circuit components are not overloaded.

Further, when the voltage of the backup power supply 10 drops, the backup power supply 10 is supplied to the electric pump 6 without stepping up, so that the hot water supply capacity of the electric pump 6 drops, so that the user has a backup power supply 10. It is possible to reduce the chances of continuing the operation until the hot water supply becomes impossible because the user notices the voltage drop.

The backup power source in this embodiment is a primary battery such as a manganese dry battery or an alkaline dry battery,
Whether a secondary battery such as a nickel-cadmium storage battery or a capacitor is used, the same effect as this embodiment can be obtained.

(Embodiment 2) A second embodiment of the present invention will be described with reference to the control circuit diagram FIG.

The basic structure of this embodiment is almost the same as that of the first embodiment shown in FIG. The difference between the first embodiment and the present embodiment is that the control circuit diagram shown in FIG. 3 is a control circuit diagram shown in FIG.
1 and 13m are added, and the LED 24a as the notification means 24 (not shown in FIG. 1) is driven by the microcomputer 15a via the resistor 24b. The following description focuses on the difference in the operation.

When a signal is input from the hot water release lock release switch 11 while the device is in the backup mode, the detection means 14 for monitoring the backup power supply 10 at that time.
The voltage level detected by (14a, 14b) is compared with a voltage level preset in the microcomputer 15a (referred to as θ2). If the voltage of the backup power supply is large, the microcomputer 15a turns off the transistor 13k to boost the voltage. The means 13 performs the same boosting operation as in the first embodiment. When the voltage of the backup power supply 10 is smaller than θ2, the transistor 13k is turned on by the central control room 15b through the resistor 13l, and the reference voltage input to the control IC 13c becomes high due to the parallel connection of the resistor 13g and the resistor 13m. Therefore, the Vu power supply is reduced. For example,
Resistor 14a = 100kΩ, resistor 14b = 100k
Ω, θ2 = 1.5V, resistor 13g = 100kΩ, resistor 13m = 100kΩ, resistor 13h = 10kΩ, reference voltage of the control IC 13c (voltage across 13h) = 1V, 1
Assuming that the ON voltage of 3k = 0V and the maximum voltage Vp of the backup power supply 10, Vout (Vu) = 11V when the input is Vp to 3V. Vout (Vu) = 6V when the input is 3V or less.

By switching the output voltage in two steps and suppressing the input current value to a low level, it is possible to use a choke coil, a switching transistor, a capacitor, etc. having a small current rating and a low power rating. Resistance, switching loss, etc. can be reduced, and there is an effect of improving efficiency.

The voltage of the backup power source 10 is θ2.
When it is smaller, the microcomputer 15a has LED2
4a is driven and blinks. Therefore, the user can use the water heater, but can know that the backup power source is exhausted and can recognize the necessity of charging. Further, at the same time, the applied voltage to the pump 6 is reduced, so that the discharge amount is reduced, so that the user can know that the backup power source has decreased.

The LED 24a is used for other purposes such as for keeping warm display.
The ED may be shared by, for example, changing from lighting to blinking, or may be an auditory notification such as a buzzer.

As described above, according to the second embodiment, by having the control means for reducing the output to the electric pump when the detected residual energy level is lowered, it can be used even without a commercial power source. Inexpensive, and that there is little remaining time that can be used without commercial power,
It is possible to provide an electric water heater capable of knowing a change in the discharge amount or a visual display or an audible display by the notification means 24.

The backup power supply in this embodiment is
Whether a primary battery such as a manganese dry battery or an alkaline dry battery, a secondary battery such as a nickel-cadmium storage battery, or a capacitor is used, the same effect as that of the present embodiment can be obtained.

In this embodiment, the output is switched in two stages depending on the level of the backup power source.
Even if the output is switched in a plurality of stages according to the input backup power supply level, the same effect can be obtained. Further, θ1 in the first embodiment is also provided in the microcomputer 15a and is set to be smaller than θ2. The effect of protecting circuit components such as switching transistors and capacitors from overcurrent and overloss can also be added.

[0032]

As described above, according to the invention described in claims 1 to 4, circuit components are prevented from being overloaded,
Further, it is possible to provide an easy-to-use electric water heater that has improved hot water discharge performance at the time of cordless dressing.

[Brief description of drawings]

FIG. 1 is a sectional view and a circuit block diagram of an electric water heater according to Embodiments 1 and 2 of the present invention.

FIG. 2 is a circuit block diagram according to the first embodiment of the present invention.

FIG. 3 is a circuit block diagram according to a second embodiment of the present invention.

[Explanation of symbols]

1 body 2 containers 3 lid 4 heating source 5 Temperature sensor 6 motor 7 Electric pump 10 backup power supply 11 Hot water lock release switch 12 Hot water switch

─────────────────────────────────────────────────── --- Continuation of front page (56) Reference JP-A-9-276144 (JP, A) JP-A-8-308733 (JP, A) JP-A-7-79562 (JP, A) JP-A-10- 94183 (JP, A) JP-A 6-83466 (JP, A) JP-A 1-283056 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A47J 27/21

Claims (5)

(57) [Claims] 1. A container for containing a liquid, an electric pump for discharging the liquid from the container, a backup power supply for supplying power to equipment when a commercial power supply is not input, and an electric pump for boosting the backup power supply. Boosting means for supplying power to the power source, and the remaining energy of the backup power source.
And a control means for controlling the drive of the electric pump. The control means stops the boosting operation of the boosting means when the residual energy detected by the detection means becomes equal to or lower than a predetermined level. Then, the electric water heater that supplies the electric power to the electric pump without boosting the backup power source. 2. The control means is characterized in that the residual energy of the backup power source detected by the detection means is lower than a predetermined level.
2. The electric water heater according to claim 1, wherein the backup power is not supplied to the electric pump when the electric power falls below a predetermined level. 3. A container for containing a liquid, an electric pump for discharging the liquid from the container, a backup power supply for supplying power to equipment when a commercial power supply is not input, and an electric pump for boosting the backup power supply. Boosting means for supplying power to the power source, and the remaining energy of the backup power source.
An electric water heater having a detection means for detecting the above, and a control means for changing the boosting level by the boosting means according to the remaining energy level detected by the detecting means. 4. The control means reduces the boosting level of the boosting means in response to a decrease in the residual energy level detected by the detecting means, and stops the boosting operation of the boosting means when the residual energy becomes equal to or lower than a predetermined level. The electric water heater according to claim 3, wherein the backup power source is supplied to the electric pump without being boosted. 5. A notifying means for visually or audibly notifying is provided, and the control circuit responds to the notifying means when the residual energy becomes a predetermined level or less and the backup power is supplied to the electric pump without stepping up. The electric water heater according to any one of claims 1 to 4, wherein the notification is made.