JPS62172918A - Electric pot with timer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an electric kettle, and more particularly to an electric kettle with a timer.

(Prior art) In general, in a reboiling electric pot, the water contained in a container is brought to a boil using a water heater, and after boiling, the water is maintained at a predetermined temperature using a heat-retaining heater, and then re-boiled as necessary. A switch is used to turn on a water heater to re-boil the water that is being kept warm.

(Problem to be Solved by the Invention) However, in this type of reboiling type electric kettle, the heat-retaining heater that maintains the water at a predetermined temperature is constantly on-off controlled, so it cannot be used for long periods of time, such as during sleep. There is a problem in that power is wasted even when the venue is not in use. In particular, in order to use hot water early in the morning, it is necessary to boil the water at night, which inevitably increases power consumption.

(Means for Solving the Problems) As a means for solving the problems, the present invention, as shown in FIGS. 1 and 2, includes a container 3 containing water, a heater 4 heating the water in the container, 5, and a heater drive circuit to, it that drives the heater 4.5, outputs a signal that turns off the heater drive circuit 10.11 and turns it on after a preset predetermined time has elapsed. a reservation timer Ta; a timer set switch means 12 for setting the reservation timer Ta; and the reservation timer T.
The heater drive circuit to, 11 is turned on by the signal from a.
A control device comprising a control means 16 for turning off the light is provided.

(Function) In the electric kettle according to the present invention, when the timer set switch 12 is pressed during operation, the reservation timer Ta is activated, and in response to the signal, the control means 16 controls the heater drive circuit 10.
．． It remains stopped. After the timer operation starts, when a certain period of time (for example, 6 hours) preset in the reservation timer Ta has elapsed, a signal is output from the reservation timer Ta, and in response to the signal, the control means 16 operates the heater drive circuit l0111. In order to do this, electricity is started to be applied to the heaters 4 and 5 to perform a water boiling operation. That is, in the present invention, by simply pressing the timer set switch 12 once, the power supply to the heater is automatically stopped for a preset time, and water is boiled after the set time has elapsed.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an electric kettle according to the present invention, in which an inner container 3 is provided inside an exterior body 2, and a water boiler heater 4 and a heat-retaining heater 5 are arranged at the bottom of the inner container 3. . Further, the lid body 6 is provided with a steam exhaust hole 7, and the cough steam exhaust hole 7 communicates with the internal space S of the inner container 3 via a steam passage 8. The steam passage 8 and the inner container 3
Temperature detection elements TH, , TH2 each consisting of a thermistor are provided on the outer surface of The water temperature is indirectly detected through the

The heater 4.5 and temperature detection elements TH, TH2 are connected to a circuit control device shown in FIG. 2, and the control device operates according to the flowchart shown in FIG.

The control device, as shown in FIG. It consists of a computer 30 and a timer set switch 12, and the water boiling heater 4 and the warming heater 5 are connected to a relay 24.1 which constitutes a drive circuit 11.10.
It is connected to an AC power source 20 via 26 contacts 24a and 26a.

In the figure, 21 is a power transformer, 22 is a rectifier circuit, 27.2
8 is a protection diode, 31.32 is a comparator, and the series circuit of the temperature detection element TH, and the resistor RI is such that the terminals S, , S provided in the microcomputer 30 connect to the resistors R, , R, respectively. The temperature sensing element TH, and the resistor R+ SR+ 1. R+t
In conjunction with this, the voltage input to the comparison input terminal 2a of the comparator 31 is changed. Therefore, in the comparator 31, by inputting a constant voltage from the reference input terminal 2b and changing the input voltage from the other comparison input terminal 2a, the two set temperatures (-20°C 17
It is designed to determine whether the steam temperature is higher or lower than 0°C.

Connection points C9d of the series circuit of temperature detection element TH2 and resistor R4 and the series circuit of resistor R5 and resistor R6 are connected to comparison input terminal 2c and reference input terminal 2d of comparator 32, respectively, and output terminal of comparator 32. f is connected to the microcomputer 30. The circuit including the temperature detection element TH also includes terminals S3. of the microcomputer 30. S4 is resistor R13, R, 4 respectively
connected via. Therefore, similarly to the comparator 31, a constant voltage is input from the reference input terminal 2d, and a voltage that varies depending on the water temperature is input from the comparison input terminal 2c, and the set temperature (-2
0.70°C).

Hereinafter, the control operation of the electric kettle 1 having the above configuration will be explained as follows.
The explanation will be given according to the flowchart shown in the figure.

When the power is turned on in step 1, the voltage of the AC power supply 20 is lowered by the transformer 21, and the voltage transformed into DC by the rectifier circuit 22 is applied to the circuit including the microcomputer 30 and temperature detection elements TH, TH9. is applied to

Next, step 2. In step 3, - a signal from the microcomputer 30 causes the temperature sensing element T to
It is determined whether the temperature detected by HI and T Ht is below 120° C., and it is determined whether the circuit having these is disconnected. If the detected temperature is less than 120° C., it is assumed that the wire is disconnected, and an abnormality is notified in step 201.

Subsequently, in step 4, the height of the liquid level in the inner container 3 is detected. This is done by providing exposed electrodes at different heights of a liquid level gauge (not shown) and the inner container 3, respectively, and measuring their electrical resistances. That is, when the amount of water is below a predetermined level, one electrode is located in the atmosphere, and the property that the electrical resistance between them becomes infinite is utilized.

Then, if the water amount is below a predetermined level, step 40
At step 1, a buzzer alerts, and at step 402, a water supply alert is issued. After that, the water amount is checked again in step 403, and if the water is not replenished to a predetermined level or higher, the process returns to step 402, and steps 402 and 403 are continued until water is supplied.
Repeat the action. If it is confirmed that the water supply is at a predetermined level or higher, the process proceeds to step 5.

In step 5, it is determined whether the switch 12 of the reservation timer Ta, which will be turned on after six hours, is turned off. Note that this reservation timer Ta is built into the microcomputer 30 shown in FIG.

If it is determined in step 5 that the reservation timer Ta is in the on state, a buzzer is issued in step 501, and the process moves to timer operation in step 502. For timer operation, step 503
The reservation timer Ta starts at step 50, and energization to the water boiling heater 4 and the warming heater 5 is not started.
At step 4, it is again determined whether the timer set switch 12 is on or off, and at step 505, it is determined whether or not the reservation timer Ta has elapsed for six hours. Therefore, if the timer set switch 12 of the reservation timer Ta is turned on after the power supply 20 is turned on in step 1, the timer set switch 12 of the reservation timer Ta is turned on, and then the step 50 is
4. Repeat the loop of step 505.

Note that while the timer is operating, the reservation timer Ta has already progressed halfway (for example, it has progressed to 4 hours).
When the timer set switch 12 of the reservation timer Ta is turned on, the reservation timer is canceled and the process returns to step 2. When it is determined in step 505 that the set time preset in the control device, that is, 6 hours has elapsed, the process moves to step 7, and after the buzzer alerts, the water boiling operation starts, and step 9
The water boiling operation from to step 17 is performed.

Further, if it is confirmed in step 5 that the timer set switch 12 is in the off state, the process proceeds to step 6, where the temperature detection element T H2 detects the water temperature, and if the temperature is 70°C or less, the process proceeds to step 6. Proceed to step 7, sound the buzzer,
The water boiling operation is started, but if the water temperature is 71'C or higher, the process proceeds to step +8, and the warming operation of steps 18 to 29 is started.

When the timer set switch 12 is turned on during the water boiling operation and the warming operation, steps 14 to 50 are performed.
1 and performs the timer operation.

In addition, in the water boiling operation, the transistor 23 is activated by a signal from the microcomputer 30, and the relay 2 is activated.
In order to turn on the contact 24a of 4, the water boiling operation by the water heater 4 starts.
b) starts (step 9). This timer (Tb
) is the time Tb(
-T+ + t+), and in this embodiment, it is set to 30 minutes.

In this water boiling operation, similarly to steps 2 to 5, the quality of the temperature detection elements T H6 and T H2 and the appropriateness of the water amount are determined (steps 10 to 12). If there is no abnormality, the reservation timer Ta is in the off state. In step 14), after starting the timer (Tb), 30
It is determined whether or not the minute has elapsed, and if it has not finished, the process proceeds to step 16, where it is determined whether or not the steam temperature detected by the temperature detection element T H+ provided in the steam passage 8 is 69°C or higher. judge. That is, it is determined whether the hot water has boiled.

If the steam temperature is below 69°C, return to step 10 again, and then repeat step 1 until the steam temperature reaches 69°C or above.
Repeat the loop from step 0 to step 16. However, if 30 minutes elapse before the steam temperature reaches 69°C, it is assumed that the temperature detection device TH is disconnected, and step 1
5 to step 151, where an abnormality is notified and the transistor 23 is operated by a signal from the microcomputer 30 to close the contact 24 of the relay 24.
A is turned off, and electricity to the water heater 4 is cut off. As a result, even if the temperature detection element TH is out of order or other equipment is out of order, the temperature will not continue to rise and damage to the body of the electric kettle 1 can be prevented.

When it is confirmed that the steam temperature has reached 69° C., the process proceeds from step 16 to step 17, the buzzer is sounded, and the process proceeds to step 18, where a heat-retaining operation begins.

When the temperature keeping operation starts, the transistor 25 is activated by a signal from the microcomputer 30, and the contact 2f3a of the relay 26 is turned on to energize the warming heater 5 to keep the hot water warm. Even in this heat retention operation, the temperature detection element T H1,
Check T Ht and water level Steps 19-21
), if there is an abnormality, step 191, 211, 4 respectively.
01, an abnormality is reported, and the transistor 25 is activated by a signal from the microcomputer 30 to turn off the contact 26a of the relay 26, thereby cutting off the power supply to the heat-retaining heater 5.

Next, in step 22, it is determined whether the water temperature is 70° C. or higher, and if it is 70° C. or higher, the process proceeds to step 23, where it is determined whether a reboiling switch (not shown) is in the on state.
If the reboiling switch is in the OFF state, the process returns to step 19 and repeats the loop from step I9 to step 23. During this time, the temperature of the hot water decreases, and when it becomes 69° C. or less, the step returns from the stirrup 22 to step 7, and the water boiling operation is started.

If it is determined in step 23 that the reboiling switch is in the on state, a buzzer is sounded in step 24, and the process proceeds to step 25, where the reboiling operation is started. Then, the water boiling heater 4 is driven by a signal from the microcomputer 30 to start the water boiling operation, and a timer (Tc) is started in step 26. This timer (
Tc) is the time Tc(-T2+t!) which is the time required for boiling (T,) plus the margin time (t,) when the inner container is filled with hot water at 70°C, and is the time Tc(-T2+t!) in this example. In this case, Tc is set to 10 minutes.

Next, in step 27, it is determined whether the timer (Tc) has expired or not, and if it is within 10 minutes, the process proceeds to step 28, where the steam temperature detected by the temperature detection element TH is 69°C.
Determine whether or not the value is greater than or equal to the value. Then, if the steam temperature is not 69° C. or higher, the process returns to step 27. During this time, the timer (T
When it is determined in step 27 that step c) has been completed, the process proceeds to step 27 (2), where an abnormality is notified and the contact 24a is turned off in response to a signal from the microcomputer 30 to cut off the power supply to the water heater 4.

In step 27, within 10 minutes, the temperature detection element TH
, when it is confirmed that the steam temperature is 69°C or higher, the process proceeds to step 29, where the buzzer sounds and the contact 24a is activated.
is turned off, the water boiling operation is stopped, and the process returns to step 18.

In the above embodiment, the necessary and sufficient boiling times for boiling and reboiling were set to 30 minutes and 10 minutes, respectively, but they are not limited to these.

(Effects of the Invention) As is clear from the above description, the electric kettle according to the present invention sets the timer by simply pressing the timer set switch and stops power supply to the heater for a predetermined period of time, so it can be used for long periods of time. Wasteful power consumption can be eliminated when not in use, for example, when sleeping, and the heater is energized to start boiling water after a predetermined time has elapsed, so the necessary hot water can be obtained even in the early morning. Furthermore, since power to the heater is stopped during sleep, unexpected disasters such as fire can be prevented and safety can be ensured, providing excellent effects.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view of an electric kettle according to the present invention;
FIG. 2 is a circuit diagram of the control device, and FIG. 3 is a flowchart of its operation. 3... Container, 4... Water boiling heater, 5... Heat retention heater, 7... Steam exhaust hole, 8... Steam passage, 12
. . . timer set switch, 10. 11. . . . evening drive circuit, Ta. . . reservation timer, 16. . . control means,
T Hl, T Ht...Temperature detection element. Patent applicant Zojirushi Mahobin Co., Ltd. Agent
Patent attorney Aoyama Aoyama and 2 others Figure 1

Claims (1)

[Claims] (1) In an electric kettle that includes a container that contains water, a heater that heats the water in the container, and a heater drive circuit that drives the heater, the heater drive circuit is turned off and a predetermined period of time is set in advance. The present invention includes a control device comprising a reservation timer that outputs a signal to be turned on after the elapse of time, a timer set switch means that sets the reservation timer, and a control means that turns on and off the heater drive circuit according to the signal from the reservation timer. An electric kettle with a timer.