JPH09224832A - Electric kettle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To pour the small amount of hot water at first, gradually increase a hot water pouring amount thereafter and attempt a maximum hot water pouring amount after the lapse of specified time so as to prevent the hot water from overflowing from a teacup in the electric kettle of a motor-driven pump used in a general household. SOLUTION: When a hot water pouring switch 9 is turned on, a control means 8 gradually output-changes a motor control voltage and thus, a voltage applied to a motor 5 is gradually increased and the hot water pouring amount is also gradually increased accompanying it. Thus, this electric kettle with improved handleability for not making poured hot water overflow from the teacup even in the case of pouring the hot water to a small empty teacup is provided.

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 ordinary households.

[0002]

2. Description of the Related Art In recent years, electric water heaters have become widespread in ordinary households, and their use has been various. In the electric water heater, as a method of discharging the hot water that has been kept warm, a method of increasing the pressure in the container holding the water of the electric water heater with an air pump was common, but recently, the electric pump pumps the hot water. The system type is also becoming popular. In addition to the hot water switch, the electric water heater that uses this electric hot water discharge method has a hot water lock function that prevents the hot water from tapping even if the hand accidentally touches the pot. The configuration provided by a circuit is general.

Recently, in addition to the amount of hot water discharged per unit time (hereinafter abbreviated as the amount of hot water discharged) that can be freely adjusted by the function of a valve, the amount of hot water discharged is fixed in advance and is simple and inexpensive. The main type of electric water heater is.

FIG. 8 is a block diagram showing the structure of a conventional general electric water heater. In FIG. 8, 41 is a container for containing a liquid, 42 is a temperature detecting means for measuring the temperature of the container 41, 43 is a heating means for heating the liquid contained in the container 41 to a boil and keeping it at a predetermined temperature. The heating heater 43a and the relay 43b, the heat retaining heater 43c, and the switching element 43d are included. A hot water discharge pump 44 discharges the liquid in the container 41 to the outside of the container 41. The hot water discharge pump 44 is driven by energizing a motor 45.

To energize the motor 45, the user first operates the lock release switch 46 to release the hot water lock. Then, the lock release lamp 47 notifying that the lock of the hot water is released is turned on, and at the same time, a high control signal is output from the lock control output of the control means 48 to the control transistor 49, and the control transistor 49 is turned on. When the hot water switch 50 is turned on in this state, the control transistor 49 is already turned on.
Is energized, the hot water pump 44 is driven and the container 41
The liquid inside is discharged to the outside of the container 41.

At this time, the power source for energizing the motor 45 is obtained from the power source 48a constituting the control means 48,
The control means 48 receives the input from the temperature detection means 42 and controls the heating means 43 to keep the temperature at a predetermined temperature after detecting that the liquid in the container 41 has boiled.
Further, the opening / closing signal of the hot water discharge switch 50 is taken into the control means 48 by the resistors 51 and 52, and by this signal, when the hot water discharge switch 50 is turned off and the hot water discharge lock is released for a predetermined time, the control means 48 The control transistor 49 is turned off and the hot water is locked again.

FIG. 9 is a timing chart of the hot water discharge operation of this conventional electric water heater. When the user releases the lock by operating the lock release switch 46 at the time point Q,
The lock control output of the control means 48 outputs High to turn on the control transistor 49. At time R, when the user operates the hot water switch 50 to try to take hot water, the motor 45 starts to be energized. Therefore, there is a slight time delay after the hot water pump 44 pushes up the hot water, and then the hot water is discharged at the maximum hot water discharge amount. Has started.

[0008]

However, in the structure of the conventional electric water heater, since the hot water in the container is discharged with the maximum amount of hot water immediately after the hot water is discharged, it is possible to pour it without any problem even if the drinker already contains the liquid. However, when trying to receive a small empty cup of water under the discharge port, the water slips or bounces from the inside of the cup until it starts to pour, and then until the cup is slightly filled.
Some of the pouring hot water sometimes spilled out of the drinking cup.

The present invention solves the above-mentioned problems. The amount of hot water discharged is reduced at the start of hot water discharge, the amount of hot water discharged is gradually increased to reach the maximum amount of hot water discharged after a predetermined time, so that hot water does not spill out. The purpose is to provide an electric water heater.

[0010]

In order to achieve the above object, the present invention provides a container for containing a liquid, a heating means for heating the liquid contained in the container, and a liquid in the container outside the container. To a motor for driving the hot water discharge pump, a motor for driving the hot water pump, a hot water switch for energizing the motor, and a control means for applying a voltage to the motor when the hot water switch is turned on. The amount of hot water discharged per unit time is gradually increased by gradually increasing the applied voltage of, and the amount of hot water discharged at the start of hot water is reduced to prevent the poured hot water from spilling from the drinking water. be able to.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a container for containing a liquid, heating means for heating the liquid contained in the container,
A hot water pump for discharging the liquid in the container to the outside of the container, a motor for driving the hot water pump, a hot water switch for energizing the motor, and a voltage applied to the motor when the hot water switch is turned on. A control means is provided, and the amount of hot water discharged per unit time is gradually increased by gradually increasing the applied voltage to the motor.

Further, according to the present invention, by turning on the hot water discharge switch, the hot water discharge is started at a predetermined hot water discharge amount per unit time, and then the applied voltage to the motor is gradually increased to further gradually increase the hot water discharge amount per unit time. To increase.

The present invention is provided with a means for selecting the amount of hot water discharged per unit time. Furthermore, the present invention gradually increases the voltage applied to the motor by means of a delay capacitor provided between the base and emitter of the control transistor located between the control means and the motor. At that time, the first and second control resistors are provided between the base of the control transistor and the control means.

By gradually increasing the motor control voltage in this manner, a small amount of hot water is discharged immediately after the start of hot water discharge, the amount of hot water discharge is gradually increased, and the maximum amount of hot water discharge is reached after a lapse of a predetermined time. Even when pouring hot water into a drinking cup, the poured hot water can be prevented from spilling from the drinking cup.

Further, by turning on the hot water switch, the hot water is immediately started to the extent that the hot water does not spill out, so that the time required to reach the cumulative total hot water output required by the user can be shortened.

If the control means is provided with a hot water discharge amount selection means, the maximum hot water discharge amount can be kept constant at an arbitrary value after the hot water discharge amount is gradually increased. It is effective when a small amount of hot water is used to overflow a small amount of water.

Further, by providing a delay capacitor between the base and the emitter of the control transistor, the voltage applied to the motor can be gradually increased, and the second control resistor is provided together with the first control resistor to discharge the hot water. In case of
When the hot water is finished, the second control output is set to the same potential as the negative output of the power supply so that the delay capacitor can be discharged quickly when the hot water finishes. You can start bathing.

[0018]

EXAMPLES Examples of the present invention will be described below with reference to FIGS.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of an electric water heater according to Embodiments 1 to 3 of the present invention. In FIG. 1, 1 is a container for containing a liquid, 2 is a thermistor, a temperature detecting means for measuring the temperature of the container 1, 3 is a liquid which is contained in the container 1 and is heated to boil, and any temperature It is a heating means for keeping heat, and is composed of a heater 3a and a relay 3b, a heater 3c and a switching element 3d, and the like.

Reference numeral 4 denotes a hot water discharge pump for discharging the liquid in the container 1 to the outside of the container 1. The hot water discharge pump 4 is driven by energizing a motor 5. To energize the motor 5, the user first operates the lock release switch 6 to release the hot water lock. Then, the lock release lamp 7 for notifying that the hot water is unlocked is turned on by the control means 8 to inform the user that hot water can be taken out.

The hot water discharge is started only when the hot water discharge switch 9 is turned on only after the hot water discharge is unlocked.

In the above structure, when the hot water outlet switch 9 is turned on, the motor control voltage is output from the control means 8 and the energization of the motor 5 is started through the circuit means 10. When the motor control output of the control means 8 gradually increases, the voltage applied to the motor 5 also gradually increases. As a result, the amount of hot water discharged gradually increases, and reaches the maximum amount of hot water discharged after a lapse of a predetermined time. Further, when the user turns off the hot water switch 9 to finish the hot water, the control means 8 is set to immediately output the motor control output for stopping the operation of the motor 5 to the circuit means 10.

FIG. 2 shows an example of a concrete circuit configuration of the control means 8 and the circuit means 10. In this embodiment, the D / A conversion output of the microcomputer 8b is used as a part of the control means 8, and the motor 5 is supplied through the circuit means 10.
Output voltage to.

At this time, it is desirable that the transistor Tr1 has a high current amplification factor of about 1500 or more in order to suppress the base current. Further, as the power source of the microcomputer 8b, a DC power source of 5V is created by the control means 8, and the power source for the motor uses a 10V DC power source as the power source 8a.

Since the current consumption of the motor 5 normally used for such an application is about 150 mA, the transistor Tr
1 requires less than about 0.1 mA of base current.
In this circuit configuration, if the resistance R1 is 2 kΩ and the resistance R2 is also 2 kΩ, the current flowing through the resistance R1 and the resistance R2 is 1 mA or more when the D / A conversion output is 5 V, which is the maximum. Well, calculating the voltage applied to the motor 5 at this time, the resistance R1 and the resistance R2
The voltage of the motor 5 is obtained by subtracting 0.7V, which is the voltage drop between the base and the emitter of the transistor Tr1, from the voltage at the connection point.

That is, when the output voltage of the D / A conversion output is 0V, the voltage of the motor 5 becomes 4.3V, which is 0.7V subtracted from the voltage 5V at the connection point of the resistors R1 and R2.
When the output voltage of the D / A conversion output is 5V, the voltage of the motor 5 is 7.5V at the connection point of the resistors R1 and R2.
Is 0.7V minus 6.8V.

In other words, when the voltage of the D / A conversion output is changed from 0V to 5V for a predetermined time of about 5 seconds, the voltage of the motor 5 changes from 4.3V to 6.8V during that time, and accordingly the amount of hot water discharged. Is gradually increasing.

Further, a transistor Tr2 is provided for controlling the hot water discharge lock. When the hot water discharge switch 9 is turned off, the off signal is taken into the microcomputer 8b of the control means 8 by the resistor 11 and the resistor 12 to output the lock control output. Is set to Low, and the transistor Tr2 is immediately turned off to stop the operation of the motor 5. When the lock is released, the transistor Tr2 is kept off only by turning on the lock release lamp 7, and when it is detected that the hot water switch 9 is turned on while the lock release lamp 7 is turned on, the transistor Tr2 is turned on. Simultaneously with turning on, the output voltage of the D / A conversion output is started to rise, and the hot water discharge operation is performed.

The hot water discharge operation of the electric water heater in this configuration will be described with reference to the timing chart of FIG.

In FIG. 3, when the user operates the lock release switch 6 to unlock the hot water supply at time A, the lock release lamp 7 lights up to inform that the hot water supply is possible. When the hot water outlet switch 9 is turned on at time B in this state, a high signal is input to the control means 8 through the resistors 11 and 12, and when the high signal is received, the lock control output of the control means 8 locks the hot water. And the output of voltage from the control means 8 is started. This motor control output is output so that the voltage of the motor 5 gradually increases from the minimum within a predetermined time and reaches a predetermined maximum value after a lapse of a certain time. Then, at time C when the motor voltage at which the motor 5 can operate is obtained, the hot water discharge pump 4 starts to be driven to start hot water discharge. As the motor control output of the control means 8 gradually increases, the output of the motor 5 also gradually increases with the amount of hot water discharged, and reaches the maximum amount of hot water discharged from the time point D after the elapse of a predetermined time to the end of the hot water discharge.

Next, when the user turns off the hot water discharge switch 9 to finish the hot water discharge at time E, a Low signal is input to the control means 8 via the resistors 11 and 12, and the motor 5 is immediately driven from the control means. Circuit means 1 to minimize
Since the motor control output is set to 0 and the drive of the motor 5 is stopped by the lock control output of the control means 8, even when the hot water switch 9 is turned on again after a short time at the time point F, the initial state is always gradually changed. In addition, the amount of tapping water can be increased, and the safety of this tapping method can always be maintained.

(Embodiment 2) Since the basic structure of this embodiment is the same as that of the first embodiment, its explanation is omitted. In the timing chart of FIG. 4, at time G, the user operates the lock release switch 6 to unlock the tap water to enable tapping, and when the tap switch 9 is turned on at time H in this state, the control means The motor control output does not increase in voltage from 0 V, but first rises the motor control output until the motor 5 is driven at a predetermined output value through the circuit means 10, and then takes a predetermined time to reach the maximum value. The motor control output is increased up to. That is, the voltage of the motor 5 at this time rises to a predetermined voltage at the same time when the hot water discharge switch 9 is turned on and starts hot water discharge, and then gradually reaches the maximum hot water discharge amount while gradually increasing the hot water discharge amount.

The operation will be described with reference to FIG. 2. When the output voltage of the D / A conversion output is 0V, the voltage of the motor 5 is 4.3V.
Can hardly be driven, and hot water is hardly discharged. Therefore, the D / A of the microcomputer 8b of the control means 8
At the same time when the hot water switch 9 is turned on, the output voltage of the conversion output is raised to, for example, 1.4 V, and the motor voltage is set to 5 V, which is the amount of hot water that does not spill out even if it is poured into a small drinking water. The output voltage of the conversion output is increased to gradually increase the amount of hot water to be discharged so that the maximum amount of hot water is discharged after a predetermined time has elapsed.

As shown in the total hot water discharge amount of FIG.
The output voltage of the D / A converted output is 1.4V, that is, the voltage of the motor 5 is started from 5V, compared to when the output voltage of the D / A converted output is 0V, that is, the voltage of the motor 5 is started from 4.3V. Time has the effect of shortening the time required to reach the cumulative total amount of hot water discharged by the user.

(Embodiment 3) Since the basic structure of this embodiment is the same as that of the embodiment 1, its explanation is omitted. In FIG. 1, reference numeral 13 denotes a hot water discharge amount selecting means, which allows the user to arbitrarily set the hot water discharge amount. Reference numeral 14 denotes a hot water discharge amount display lamp showing the selected hot water discharge amount, which lights the lamp corresponding to the selected hot water discharge amount to inform the user of the currently selected hot water discharge amount.

FIG. 5 shows a timing chart when the amount of tapping water selection means is used. If the user arbitrarily selects the hot water discharge amount by the hot water discharge amount selection means 13 in advance, the motor control output should be kept constant while the voltage of the D / A conversion output of the control means 8 is being increased. With this, the voltage supplied to the motor 5 can be kept constant, and as a result, the amount of hot water discharged can be maintained at an arbitrary amount selected by the user from among three levels of low, medium, and high. As a result, as shown in the total hot water discharge amount of FIG. 5, if the small hot water discharge amount is kept small, the expansion of the total hot water discharge amount can be suppressed.

In this embodiment, the selection of the amount of hot water discharged is set in three stages, but the upper limit of the stage setting of the amount of hot water discharged is determined by the output stage of the voltage by the control means 8, so that it is, for example, 8 bits. If you use a microcomputer with an output terminal for D / A conversion output, you will be able to set the motor voltage in 256 steps, and in practice you can adjust the amount of hot water that is equivalent to steplessly changing the amount of hot water. it can.

In each of the above-described embodiments, the motor control output is increased by a certain slope that is proportional to time. However, any slope may be used, and the slope may be changed in the middle, or a curve may be used. It is needless to say that the same effect can be obtained as long as the amount of tapping water is gradually increased by a non-continuous method of increasing the gradient in several steps or by another method.

In each of the above-mentioned embodiments, since the circuit configuration uses the NPN transistor, the motor control output of the control means 8 is increased in a predetermined time so that the minimum voltage changes to the maximum voltage direction. However, in the case of the circuit configuration using the PNP transistor, the motor control output of the control means 8 is also decreased in a predetermined time, that is, if the maximum voltage is changed to the minimum voltage direction, the motor voltage is similarly controlled. It goes without saying that you can do it.

In each of the above embodiments, the hot water discharge lock function is provided by the control means 8. However, when the hot water discharge lock function is not provided, the control means 8 indicates that the hot water discharge switch 9 has been turned on. It goes without saying that the same effect can be obtained by gradually increasing the amount of hot water discharged from the time of acceptance.

(Embodiment 4) FIG. 6 is a block diagram showing the structure of an electric water heater according to Embodiments 4 and 5 of the present invention. In FIG. 6, 21 is a container for containing a liquid, 22 is a thermistor and is a temperature detecting means for measuring the temperature of the container 21, and 23 is a liquid which is contained in the container 21 and is heated to a boil and has an arbitrary temperature. It is a heating means for keeping the temperature high, and is composed of a heating heater 23a and a relay 23b, a warming heater 23c, a switching element 23d and the like.
A hot water discharge pump 24 discharges the liquid in the container 21 to the outside of the container 21. The hot water discharge pump 24 is driven by energizing a motor 25. To energize the motor 25, the user first operates the lock release switch 26 to release the hot water lock. Then, the lock release lamp 27 for notifying that the hot water is unlocked is turned on by the control means 28 to inform the user that hot water can be taken out.

The hot water discharge switch 29 is turned on only after the hot water discharge lock is released, and the hot water discharge is started.

In the above structure, when the hot water outlet switch 29 is turned on, a voltage is output from the control means 28. At this time, since the delay capacitor 31 that is charged through the first control resistor 30 is provided, the control transistor is provided. The motor current flowing through 32 is gradually increased, and the amount of hot water discharged is also gradually increased.

The tapping operation of the electric water heater having the above structure will be described with reference to the timing chart of FIG.

In FIG. 7, when the user operates the lock release switch 26 to unlock the tap water at time K,
The lock release lamp lights up and the bath is ready for tapping. When the hot water switch 29 is turned on at time L in this state,
A High signal is input to the control unit 28 via the resistors 33 and 34, and when the High signal is received, a voltage is output by the control output of the control unit 28, so that energization of the control transistor 32 is started. At this time, the voltage of the delay capacitor 31 charged through the first control resistor 30 rises according to the time constants of the first control resistor 30 and the delay capacitor 31 as shown in FIG. It will be the maximum value later. At this time, the base current of the control transistor 32 begins to be supplied when the base voltage, that is, the voltage of the delay capacitor 31 exceeds about 0.7V, and thereafter gradually increases as the voltage of the delay capacitor 31 increases. The motor current flowing through the control transistor 32 at this time also follows the current amplification factor of the control transistor 32.
It rises as the base current increases. As a result, the amount of hot water discharged is initially small and gradually increases and reaches a maximum after a predetermined time has elapsed, and thereafter, the amount of hot water discharged is maintained. This has the effect that even when pouring hot water into a small empty cup, the poured hot water does not spill out of the cup.

Further, in the timing chart of FIG.
When the hot water switch 29 is turned off at time M, a Low signal is input to the control means 28 via the resistors 33 and 34,
Upon receiving this Low signal, the control output of the control means 8 immediately outputs Low. However, if this is left as it is, the voltage of the delay capacitor 31 discharges with the same time constant as that at the time of charging as shown by the dotted line in FIG. In such a situation, it will not start from the minimum value. Therefore, apart from the first control resistor 30 connected to the control output of the control means 28, a second control resistor 35 is provided.
Is connected between the base of the control transistor and the second control output of the control means, and the second control output is set to High at the same time as the hot water tap switch 29 is turned on. Same potential as negative output. Then, the first control resistor 30 and the second control resistor 35
Since the discharge is performed by both of the above, the voltage charged in the delay capacitor 31 is quickly discharged as shown by the solid line after the time M in FIG. 7, and as a result, after the time N when the hot water switch 29 is turned on, The base current of the control transistor 32, the motor current of the motor 25, and the hot water discharge amount are also restarted from the minimum values.

As a result, even when the hot-water discharge operation is continuously performed in a short time, the hot-water discharge is started from the minimum value, so that there is an effect that safety can always be ensured.

Although only one second control resistor 35 is provided in this embodiment, one terminal is connected to the base of the control transistor 32 and the other end is connected to the third control means of the control means 28. It goes without saying that the third control resistor connected may be provided, or even if a plurality of control resistors are provided, the same or higher effect can be obtained.

In this embodiment, since the circuit configuration uses the NPN transistor, both the control output and the second control output change from the minimum voltage to the maximum voltage direction, but the PNP transistor is used. In the case of the circuit configuration, if both the control output and the second control output are changed from the maximum voltage direction to the minimum voltage direction, the control transistor (P
It goes without saying that the base current of the NP transistor) can be controlled. In the circuit configuration in that case, the collector of the control transistor (PNP transistor) is connected to the positive output of the power supply, and the positive input terminal of the motor is connected to the emitter. If one terminal of the hot water switch is connected to the negative input terminal of the motor and the other terminal of the hot water switch is connected to the negative output of the power source, the same effect as that of this embodiment can be obtained.

The input / output of the control means 28 in each of the above embodiments is generally determined by a microcomputer program.

[0051]

As described above, according to the present invention, when the hot water discharge switch is turned on, the control means gradually changes the motor control voltage, whereby the voltage applied to the motor gradually increases, and the hot water discharge amount accordingly. Since it also gradually increases, it is possible to provide an electric water heater that prevents the poured hot water from spilling out even when pouring hot water into a small empty teacup.

Further, by turning on the hot water switch, the hot water is started at a predetermined hot water amount per unit time, after which the applied voltage to the motor is gradually increased to further gradually increase the hot water discharge amount per unit time. As a result, it is possible to provide an electric water heater that can shorten the time required to reach the cumulative total amount of hot water discharged by the user.

Further, when the means for selecting the amount of hot water discharged per unit time is provided, the maximum amount of hot water discharged can be selected and held with a simple structure after the amount of hot water discharged is gradually increased. It is possible to provide an easy-to-use electric water heater that can continuously supply a small amount of hot water.

Also, by connecting a delay capacitor between the base and emitter of the control transistor, it is possible to provide an electric water heater in which poured hot water does not spill out of the drinking water, and at the end of tapping, the voltage charged in the delay capacitor is discharged. When the second control resistor is provided, the delay capacitor can be returned to the initial state immediately after the tapping is finished, and the tapping amount can be gradually increased from the minimum tapping amount when the tapping is started next time. It is possible to provide an electric water heater with increased safety.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an electric water heater according to Embodiments 1 to 3 of the present invention.

FIG. 2 is a circuit diagram of a main part of the electric water heater according to the first to third embodiments of the present invention.

FIG. 3 is a timing chart showing the operation of the first embodiment of the present invention.

FIG. 4 is a timing chart showing the operation of the second embodiment of the present invention.

FIG. 5 is a timing chart showing the operation of the third embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of an electric water heater according to Embodiments 4 and 5 of the present invention.

FIG. 7 is a timing chart showing the operation of the fourth and fifth embodiments of the present invention.

FIG. 8 is a block diagram showing the configuration of a conventional electric water heater.

FIG. 9 is a timing chart showing the operation of a conventional electric water heater.

[Explanation of symbols]

 1, 21, 41 Container 3, 23, 43 Heating means 4, 24, 44 Hot water pump 5, 25, 45 Motor 8, 28, 48 Control means 9, 29, 50 Hot water switch 10 Circuit means 13 Hot water amount selection means 30th 1 control resistor 31 delay capacitor 32 control transistor 35 second control resistor

Claims (5)

[Claims] 1. A container for containing a liquid, a heating means for heating the liquid contained in the container, a hot water pump for discharging the liquid in the container to the outside of the container, and a motor for driving the hot water pump. A hot water switch for energizing the motor, and a control means for applying a voltage to the motor when the hot water switch is turned on. By gradually increasing the applied voltage to the motor, An electric water heater characterized by gradually increasing the amount of hot water discharged. 2. The amount of hot water discharged per unit time is further gradually increased by starting the hot water discharge with a predetermined amount of hot water discharged per unit time by turning on the hot water switch, and then gradually increasing the applied voltage to the motor. The electric water heater according to claim 1, wherein the electric water heater is provided. 3. The electric water heater according to claim 1, further comprising means for selecting the amount of hot water discharged per unit time. 4. The electric device according to claim 1, wherein the voltage applied to the motor is gradually increased by a delay capacitor provided between the base and the emitter of a control transistor located between the control means and the motor. Water heater. 5. The electric water heater according to claim 4, further comprising first and second control resistors provided between the base of the control transistor and the control means.