JPH0450005B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to improvements in electric pots.

[Technical background of the invention and its problems]

In the case of conventional electric pots, water is supplied into the pot and the water is raised to a predetermined temperature, for example 92℃, and when this temperature reaches 92℃, the built-in heating device keeps the temperature of the water constant at 92℃. It keeps it warm. The fact that the hot water has reached 92°C is notified to the user by, for example, turning off the boiling water lamp.

Therefore, conventional electric pots do not have the ability to boil water, and therefore an electric pot that has the function of boiling water and then keeping it warm is desired. Also, for users during the hot water bath,
It is necessary to display a temperature display to indicate that the water is hot before it reaches 92°C, but conventional pots were not equipped with such display means. Therefore, there is also a demand for electric pots having such display means.

[Purpose of the invention]

The present invention was made based on the above circumstances, and
The object is to provide an electric pot that can bring the water supplied to the boiler to a boil and can notify when the water has reached near the boiling temperature.

[Summary of the invention]

According to the present invention, when the water temperature in the electric kettle reaches near the boiling temperature at which it begins to boil, the boiling notification control means blinks a display element for boiling water to notify this, and furthermore, when the water temperature reaches the boiling temperature, the electric pot This electric pot is designed to keep the water warm by turning off the kettle heater relay that heats the water in the pot, and then turning on the heat-retaining heater relay after a predetermined period of time has elapsed since the water was turned off.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 9. FIG. 1 is an external view of the electric pot. In FIG. 1, an upper cover 2 and a lower cover 3 are provided on the upper part of a case body 1 so as to fit therein, and a handle 4 is provided on the lower cover 3 so as to be rotatable about its tip. A nameplate 5 is provided on the side surface of the case body 1. This nameplate 5 includes a water level gauge window 6, a start/cancel switch 7a,
Timer switch 7b and boiling switch 7c
Furthermore, a display section 8 is provided for displaying boiling water, boiling complete, normal water boiling, and keeping warm. In addition, 9 is a lock button, 10 is a steam hole, 11 is a tap button, 12 is a hot water tap, 13 is a power plug and its cord, 14 is a power plug receptacle, and 15 is a leg.

FIG. 2 is a configuration diagram of a control circuit that controls the electric pot related to book gripping. Integrated circuit (IC) 2
0 is connected to a stabilized power supply circuit 21 composed of well-known transistors. Further, a series circuit of a 670W water heater H1, a 50W heat-retaining heater H2, and a heat-retaining temperature detector (heat-retaining thermoswitch) TRS are connected to the power source 21a in parallel. Then, the water heater H1 is operated by the water heater relay RL1 being energized, and the water heater H2 is activated by the water heater relay RL1.
It is configured to operate when RL2 is energized. In addition, these relays RL1, RL2
One end thereof is connected to the IC 20 and is energized by a signal from the IC 20.

The water temperature detector TH1 detects the water temperature in the electric pot, and uses a thermistor with negative characteristics. And the water temperature detector TH1 is a Zener diode.
ZD, resistors R1 to R4, and a capacitor C are connected to the IC 20 via a reference voltage circuit 22. Note that the IC 20 includes a central processing unit (CPU), random access memory, and read-only memory. This IC20 has the following functions.
That is, when the water temperature in the pot reaches the near-boiling temperature (85°C) where the water begins to boil, the boiling water display element (LED) 8a on the display section 8 blinks, and after reaching the boiling temperature, the water temperature is increased for a predetermined period of time (30 seconds). The boiling alarm function turns off the LED 8a for indicating boiling water and turns on the LED 8b for indicating boiling completion after a predetermined period of time has elapsed, and when the boiling temperature is reached, the water heater relay RL1 is de-energized. This is a heater control function that energizes the heat retention heater relay RL2 after the predetermined time (30 seconds).

Now, this IC20 has diodes D1 and D
A start/cancel switch 7a, a timer switch 7b, and a boiling switch 7c are connected through the switches 2 and D3, respectively.
The other ends of b and 7c are commonly connected to the IC 20. When the start/cancel switch 7a is pressed, it is determined that the start has started, and when it is pressed again, it is determined that the start is canceled.

Furthermore, the display section 8 is connected to the IC 20 via resistors R5 to R9. This display section 8
LED 8a for boiling water display, LED 8b for boiling completion display, LED 8c for normal boiling water display, LED 8d for heat retention display, and LED 8 for timer setting display.
It has a configuration in which e to 8n are connected in a matrix.

Next, the operation of the apparatus configured as described above will be explained. When the power is turned on, the stabilized power supply circuit 21
When power is supplied to the IC 20, the IC 20 receives an interrupt at regular intervals according to a command from the CPU, and operates according to the interrupt flowchart shown in FIG. Based on the command, the CPU of the IC 20 lights up the LEDs 8a to 8n in predetermined numbers every time an interrupt occurs. For example, LED8a~8n
LED8a~8d, LED8e~8i, LED8j~
These are divided into 8n and turned on sequentially for each interrupt.
Then, the timer function in the IC 20 performs counting. This timer function uses the time set in this control device, for example, the time from when the boiling switch 7c is pressed until the start/cancel switch 7a is pressed, 10 seconds, and the time from when the water boils to when the water temperature is measured. Count 30 seconds etc. Next, it is determined whether the temperature inside the electric pot is 110℃ or higher based on the detection signal from the water temperature detector TH1,
If the temperature is over 110 degrees, a flag will be raised. Also
If it is below 110℃, start/cancel switch 7
a, timer switch 7b, boiling switch 7c
Take in the state of. And these switches 7a~
7c is fetched, and if the start/cancel switch 7a is in the closed state, it is read from the RAM to determine whether the start/cancel switch 7a was in the closed state at the time of the previous interrupt, and it is determined that the start/cancel switch 7a was also in the closed state at the previous time. If there is, shift is performed for the next interrupt. However, if it was open last time, it is determined whether the electric pot is currently in operation. If it is in the operating state, it is set to cancel, and if it is not in the operating state, it is set to start the operation. If the previous start/cancel switch 7a is not pressed, it is determined whether the timer switch 7b is pressed. If timer switch 7b is pressed,
Clear the count of the timer function and set the timer. If the timer switch 7b is not pressed, it is determined whether the boiling switch 7c is pressed, and if it is pressed, the count of the timer function is similarly cleared and the boiling operation is set.

Now, for the main operation, the CPU is the fourth
The electric pot is controlled by issuing commands according to the flowcharts shown in FIGS. FIG. 4 is a main flowchart, and the CPU reads the states of the start/cancel switch 7a, timer switch 7b, and boiling switch 7c according to this main flowchart, and switches these switches 7a to 7c.
A command is issued depending on the state of 7c. Therefore, after enabling interrupts, the operation of the IC 20 is initialized.
Then, determine whether the pot is dry-fired or not.
This flag is set when the inside of the pot is 110°C or higher based on the detection signal from the water temperature detector TH1 during the interrupt operation. Therefore, if this flag is set, it is determined that the water heater is in a dry boiling state, and the water heater relay RL1 is turned off. The temperature above 110°C is set here because even if water is supplied into the pot, heated and boiled, the temperature will not exceed 110°C.
However, if heating is performed without water being supplied, the temperature inside the pot will rise to over 110°C.

Next, after blinking the LEDs 8a to 8n, it is determined whether the start/cancel switch 7a is pressed. If the start/cancel switch 7a is pressed, the flow chart of the energy saving/warming operation shown in FIG. 6 (hereinafter abbreviated as "energy saving/warming flow chart") is entered. On the other hand, if dry firing is not determined, it is determined whether or not the timer switch 7b is pressed. If the timer switch 7b is pressed, the process moves to the timer setting flowchart shown in FIG. Further, if the timer switch 7b is not pressed, it is determined whether the start/cancel switch 7a is pressed. At this point, if the start/cancel switch 7a is pressed, the process moves to the energy saving/warming flowchart. If it is not pressed, the water temperature is read based on the detection signal from the water temperature detector TH1, and it is determined whether the water temperature is 85°C or lower. If the temperature is 85℃ or higher, proceed to the energy saving/heat retention flowchart. If it is below 85°C, it is determined whether the boiling switch 7c is pressed, and if it is, the water temperature is detected again, and if it is above 85°C, the boiling water indicator LED 8a is blinked. Then, if the start/cancel switch 7a is pressed within 10 seconds (from the count value of the counter function) after the boiling switch 7c is pressed, the process moves to the boiling flowchart shown in FIG.

Assume that while reading the states of the start/cancel switch 7a, timer switch 7b, and boiling switch 7c, for example, the boiling switch 7c is pressed and then the start/cancel switch 7a is pressed. The CPU that does this operates according to the main flowchart, determines that the boiling switch 7c and start/cancel switch 7a are pressed, moves to the boiling flowchart, and issues a command according to this flowchart. . First, initialization for boiling operation is performed, and then the boiling water display LED 8a is turned on. At the same time, the kettle heater relay RL1 is energized, its a contact RL1a is closed, and electric power is supplied to the kettle heater H1. As a result, the water in the pot is heated and its temperature rises as shown in FIG. Note that if the start/cancel switch 7a is pressed because the user does not need to perform boiling depending on the degree of boiling, the boiling operation is stopped and the main flowchart is initialized, and each switch 7 is pressed again.
Read the status of a to 7c.

When the water temperature rises and the detection signal from the water temperature detector TH1 determines that it has reached 85℃ or higher (Figure 8 B), the pre-boiling temperature, the CPU displays the boiling water indicator LED.
8a blinks. In FIG. 8, a shows the temperature change when boiling water, and b shows the temperature change when boiling water normally. When the water in the pot reaches a boiling state, the water temperature stabilizes at a constant temperature as shown in FIG. 8 (FIG. 8 b). The CPU compares the water temperature 30 seconds ago with the current water temperature in order to detect when the water temperature has boiled and become constant.

Specifically, when the water temperature rises and reaches 85°C as shown in Figure 9, the temperature is measured and calculated every 3 seconds. When water boils, it turns into steam and evaporates, so the temperature remains constant. In other words, if the boiling point is reached between points a3 and a4 as shown in FIG. 9, the water temperature remains constant thereafter. Boiling is determined when the temperature change after 30 seconds is within 0.5 degrees three times in a row. For example, 30 from a1 point
At point a1' seconds later, the difference is more than 0.5deg, so
It deviates from the boiling conditions mentioned above. Similarly, a2', a
Since there is a difference of 0.5deg or more for 3', it is not determined that it is boiling.

Regarding point a4', 30 seconds have passed since it entered the boiling region, and the difference from point a4 is within 0.5 degrees. Therefore, it is counted as one occurrence of boiling conditions. Similarly, the temperature difference between a5' and a5 and a6' and a6 for 30 seconds is within 0.5 deg. Therefore, a4', a
There is a temperature difference of 30 seconds at 5' and a6' three times in a row.
Since the temperature is within 0.5 degrees, it is determined that boiling occurred at a6'. If it is determined that the water has boiled, the boiling water display LED 8a continues blinking and the water heater relay RL1 is de-energized. As a result, the supply of electric power to the water heater H1 is stopped, and the heating of water is stopped. Then, after a predetermined time T, for example 30 seconds, after the CPU determines that the water has boiled, the boiling completion display LED 8b is turned on, the boiling water display LED 8a stops blinking, and the energy saving/warming flowchart moves on.

Next, the CPU issues commands according to this energy saving/thermal insulation flowchart. Therefore, it is determined whether the timer switch 7b and the boiling switch 7c are pressed. First, if the timer switch 7b is pressed, the process moves to the timer flowchart. Also, if the boiling switch 7c is pressed, the water temperature is read and if it is over 85°C, the boiling water display LED 8a blinks to determine whether the start/cancel switch 7a is pressed, and if it is, the water will boil again. Move to flowchart. Based on the above judgment, if switches 7b and 7c are not pressed, the water temperature detector
The water temperature was read from the detection signal from TH1 and was 93℃.
If the above is the case, the heat retention display LED 8d is turned on, the water heater relay RL1 is de-energized, the power supply to the water heater H1 is stopped, and the water heater relay RL2 is energized to
The contact RL2a is closed and power is supplied to the heat-retaining heater H2. And thermoswitch TRS for heat retention
The heat retention operation is performed in response to this. In addition, if the boiling water is controlled according to the boiling flow chart and the boiling water is immediately kept warm according to the energy saving/warming flow chart, the water temperature will most likely be 85°C or higher, so the LED 8d for keeping warm display will be turned on immediately.
lights up and the thermal insulation heater relay RL2 is energized.
On the other hand, if the water temperature is below 85℃, the heat retention heater relay RL2 is de-energized and the boiling completion indication LED8b
is turned off, the normal water boiling display LED 8c is turned on, and the water boiling heater relay RL1 is energized. This heats the water in the pot. When the water temperature rises and reaches 96.5℃ or higher, the water heater relay RL1 is de-energized and the heat retention heater relay RL is turned off.
2 is energized. In other words, if the water temperature is determined to be below 85°C, the water will be heated normally until it reaches 96.5°C, and once it reaches 96.5°C, it will be kept warm. Note that during normal water boiling operation, it is constantly checked whether the timer switch 7b and the boiling switch 7c are pressed.

Note that when the timer switch 7b is pressed, boiling operation, normal water boiling operation, etc. are performed after a desired time period set by the user in the timer function has elapsed. That is, the CPU issues commands according to the timer flowchart shown in FIG. First, the water heater relay RL1 is de-energized. Here, the user sets a desired time, and this set time is stored in the RAM. If the start/cancel switch 7a is pressed within 10 seconds after the desired time has been set, the set time will be counted by the timer function. For example 4
If you set the time, four of the timer setting display LEDs 8e to 8n
8h lights up. Then, each hour passes, one LED goes out to display the elapsed time. Then, when the set time has elapsed, the CPU will direct you to the energy saving/warmth retention flowchart.

In this way, in this pot, water is boiled according to the states of the start/cancel switch 7a, the timer switch 7b, and the boiling switch 7c.
Normally, water boiling, warming, and timer setting operations are carried out.In particular, in boiling water operation, when the temperature reaches 85℃ before boiling, the boiling water display LED 8a blinks, and when boiling is detected, the boiling water display LED 8a flashes. Water heater H is blinking.
After stopping the power supply to 1, after 30 seconds, the boiling completion indicator LED 8b is turned on and the warming operation starts, so the boiling water indicator LED 8a blinks before the water boils. It is possible to notify that the water in the pot has reached a high temperature and is in danger. Also, the relay is turned on for 30 seconds after it boils.
Since RL1 and RL2 are not energized, the first
It is possible to prevent steam from violently blowing out from the steam hole 10 shown in the figure.

In addition, the water in the pot can be heated normally (96.5
℃) or boiling, and furthermore, these operations can be performed after a desired period of time has elapsed. This time setting can be set for up to 10 hours.

In addition, when detecting boiling, three consecutive
Since the condition is within 0.5deg, detection is reliable, and instead of requiring a detection time of 30 seconds x 3 = 90 seconds, it can be detected in just 36 seconds as shown in Figure 9. So you don't have to boil it any more than necessary. (The modification shown in Figure 10 requires 90 seconds.) Also, even if the boiling point changes due to changes in the surrounding atmospheric pressure, there are always changing points such as a3 to a4 shown in Figure 9, so the boiling point (pressure) Boiling can be detected regardless of the

Note that the present invention is not limited to the above embodiment. In the above embodiment, the boiling switch 7
Start/cancel switch 7a after b is pressed
Although the time from when the timer is set and the time from when the start/cancel switch 7a is pressed to when the start/cancel switch 7a is pressed is set to 10 seconds, the present invention is not limited to this.

Furthermore, although the dangerous temperature display has been set at 85°C, it is not limited to this 85°C, and should just be set near the boiling temperature.

In addition, as a boiling water alarm, in addition to the boiling water display LED 8a, there is also a notification buzzer, synthetic voice,
Alternatively, a device that uses light such as an LED and a device that uses sound such as a buzzer may be used in combination.

Boiling detection is not limited to the above embodiment; as shown in Figure 10, once the water temperature reaches 85°C, the water temperature is measured and calculated every 30 seconds, and the temperature change is detected three times in a row.
Boiling may be determined when the temperature is within 0.5deg.

In addition, in the above embodiment, it was within 0.5 degrees in 30 seconds, but there is no need to be particular about this value; for example, 1
It may be within 1 degree per minute, or within 0.25 degree for 15 seconds. Also, if it is within 0.5 degrees in 1 minute, it will take more time, but the detection accuracy will improve.

Furthermore, in the above-mentioned embodiment, boiling was determined when the temperature change was small three times in a row, but the detection time could be shortened by determining the temperature change twice or once, although the accuracy is somewhat degraded. Conversely, increasing the number will improve accuracy.

In other words, this device may be modified without departing from its gist.

〔Effect of the invention〕

According to the present invention, the water heater heats the water until it boils, and when it reaches near the boiling temperature, the boiling water display element flashes, so that the supplied water can be brought to a boil and the water reaches the vicinity of the boiling temperature. We can provide an electric pot that can notify you of the situation.

[Brief explanation of the drawing]

FIG. 1 is an external view of an electric pot according to the present invention, FIG. 2 is a circuit configuration diagram showing an embodiment of a control circuit in an electric pot according to the present invention, and FIGS. 3 to 7
The figures are flowcharts showing the processing in this device; Fig. 3 is a flowchart for interrupts, Fig. 4 is a main flowchart, Fig. 5 is a flowchart for boiling processing, and Fig. 6 is a flowchart for normal water boiling and warming. Flowchart: Figure 7 is a flowchart for setting the timer, Figure 8 is a diagram showing changes in water temperature controlled by this pot, Figure 9 is a diagram for explaining boiling detection, and Figure 10 is a diagram for explaining boiling detection and other methods. FIG. 2 is a diagram for explaining a detection method. 7a...Start/cancel switch, 7b...
Timer switch, 7c... Boiling switch, 8
a...LED for indicating boiling water, 8b...LED for indicating boiling completion, 8c...LED for indicating normal boiling water,
8d...LED for heat retention display, 8e-8n...LED for timer setting display, 20...Integrated circuit (IC), 2
1... Stabilized power supply circuit, 22... Reference voltage circuit,
H1...Kettle heater, H2...Warmth heater,
RL1...Kettle heater relay, RL2...Warm heater relay, TH1...Water temperature detector, TRS...
...Temperature detector for keeping warm.

Claims (1)

[Claims] 1. A display device having at least a display element for boiling water, a water temperature detection means for detecting the water temperature in the pot, a water heater with a relatively large calorific value for controlling the water in the pot, and the water temperature detector. a water boiling heater control means for controlling the operation of the water boiling heater in accordance with a detection signal of the water boiling water heater, a water heating heater controlling means for controlling the operation of the water boiling heater according to a detection signal of the water boiling water heater; A heat-retaining thermoswitch forming a heat-retaining circuit, a heat-retaining operation permission means for permitting the operation of the heat-retaining circuit, and a detection signal from the water temperature detector are used to control the temperature of the water after the water temperature in the pot reaches near the boiling temperature. boiling alarm control means for controlling the operation of the display element for boiling water until a predetermined period of time elapses after reaching the boiling temperature, and a detection signal from the water temperature detector indicates that the water temperature in the pot has reached the boiling temperature. An electric pot characterized in that the operation of the kettle heater control means is sometimes stopped, and the warming operation permission means is operated after the predetermined period of time has elapsed from this stop.