JPS6016334Y2 - boiling electric pot - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a boiling type electric kettle.

Conventional electric pots keep the water in the pot at 90°C to 95°C.
It was used to boil water and then keep it warm, so it was not possible to use water that had already been boiled.

However, it is said that tea etc. tastes best when water is boiled at around 70 degrees Celsius, and an electric kettle capable of supplying such hot water has been desired.

However, electric kettles boil water with a calorific value of, for example, 600W to 800W, and if you try to boil water with such a calorific value, a large amount of steam will be generated inside the pot and the steam pressure will become abnormally high. There is a risk of accidents such as burns due to a large amount of spray.

This idea was made in view of these points, and the aim is to provide a boiling type electric kettle that can obtain hot water once it has been boiled and can also control boiling well without generating a large amount of steam. purpose.

Hereinafter, embodiments of this invention will be described with reference to the drawings.

A heating element 3 having a heating value of 570 W, for example, is connected to a commercial AC power source 1 via a first temperature-sensitive switch.

The first temperature-sensitive switch 2 opens when the water temperature in the pot reaches a relatively high first temperature level of Q1°C,
It is set so that it will not close unless the temperature reaches 02° C. or lower, which is a second temperature level that is sufficiently lower than the Q□° C. at which it is once opened.

Further, a heating and heat-retaining heating element 6 having a calorific value of, for example, 100 W is connected to the power source 1 through a diode 4 and a temperature-sensitive reed switch 5 as a second temperature-sensitive switch in series.

The temperature-sensitive reed switch 5 is set to open when the water temperature in the pot is above 01°C, which is the heat retention level, and to close when it falls below Q□°C.

That is, in this embodiment, the first temperature level and the heat retention level are made equal.

A timer motor 7 is connected in parallel to the first temperature-sensitive switch 2, and a timer contact 8, which is driven to open and close by the timer motor 7, is connected in parallel to the series circuit of the diode 4 and the temperature-sensitive reed switch 5. ing.

The timer motor 7 has an internal resistance value of about 20 ohms, and closes the timer contact 8 for a time T sufficient for the water temperature in the pot to boil after energization is started, and then keeps it open and de-energizes it. This causes the timer contact 8 to return to the closed state.

In the embodiment of the present invention constructed in this manner, when water at room temperature is placed in the pot and the power supply 1 is turned on at a certain time, the first temperature-sensitive switch 2 and the timer contact 8 are closed at this point. The heating element 3 is the second temperature-sensitive switch 2
Electricity is started via the heating element 6 for heating and keeping warm.
energization is started via the timer contact 8.

Thus, the temperature of the water in the pot is rapidly raised by a total of 670 W, which is 570 W from the heating element 3 and 100 W from the heating element 6 for heating and keeping warm.

Then, when the water temperature reaches 01° C. at the specified time, the first temperature-sensitive switch 2 is opened, and the timer motor 7 is then started to be energized.

At this time, since the internal resistance value of the timer motor 7 is approximately 20 ohms, which is extremely large compared to the resistance value of 17.5 ohms of the heating element 3, most of the power supply voltage is applied between both ends of the timer motor 7. As a result, the heat generated by the heating element 3 is reduced to an almost negligible level.

However, after the end of the day, the water in the pot is heated only by the 100W heating element 6 for heating and keeping warm, and the temperature rises more slowly than before, reaching just below the boiling point.
The temperature will approach 00℃.

Then, at time t2, the water in the pot reaches the boiling point and boils.

Then, the time T elapses after energization of the timer motor 7 starts at the time (ε timer motor 7).
The timer contact 8 is opened.

In this way, the power supply to the heating and heat-retaining heating element 6 is stopped, and thereafter the water temperature in the pot gradually decreases.

And the water temperature in the pot is Ql.

When the temperature drops below C, the temperature-sensitive reed switch 5 is closed, and electricity is applied to the heating and heat-retaining heating element 6 through the diode and the temperature-sensitive reed switch 5, and the heating element 6 generates heat at 50 W by a half wave. become.

In this way, the water temperature in the pot will rise again.

When the water temperature reaches 01° C., the temperature-sensitive reed switch 5 is opened and the water temperature in the pot drops again.

Thereafter, the temperature-sensitive reed switch 5 opens and closes at Q□°C, keeping the water temperature in the pot constant at 11°C.
You will have to wait for hot water.

If the water temperature change in the above operation is shown in a graph, it will be as shown in FIG.

Also, when the water in the pot is kept warm, room temperature water is replenished into the pot, and as a result, the water temperature in the pot is 0.2
If the temperature drops below .degree. C., the first temperature-sensitive switch 2 closes and the heating element 3 starts generating heat again.

Furthermore, since the first temperature-sensitive switch 2 is closed, both ends of the timer motor 7 are short-circuited, so that the power supply to the timer motor 7 is stopped and the timer contact 8 is returned to the closed state.

As a result, the heating and heat-retaining heating element 6 generates heat at 100W again.

In this way, when the water temperature inside the pot drops below 02℃, the water inside the pot is heated to 670W again by both light heating elements 3 and 6.
The water is heated and the boiling temperature is controlled.

In this way, since the water in the pot is once boiled and then kept warm at the heat retention temperature Q1°C, it is possible to reliably obtain hot water that has been once boiled.

Furthermore, when the water temperature in the pot reaches 01°C, the heating element 3 is turned off to reduce the amount of heat generated, so that the boiling point is gradually reached, and the boiling operation is performed only for the required time with the reduced amount of heat generated. Therefore, the steam pressure inside the pot will not rise abnormally, and it can be sufficiently countered by providing a simple steam vent hole.

Further, there is no risk of a large amount of steam spewing out from the steam vent hole.

Therefore, good boiling control can be achieved.

Note that in the above embodiment, the first temperature level and the heat retention level were made equal, but they are not necessarily limited to this and may be different.

As detailed above, according to this invention, until the water temperature in the bottle reaches the preset relatively high first temperature level, a heating element with a relatively large calorific value and a heating element with a relatively small calorific value are used. When the water temperature reaches the first temperature level, the water in the pot is heated with full waves to control the water in the pot to boil, and then the timer contact is turned on. When the water is opened, the water in the pot is heated by the above-mentioned heating and heat-retaining heating element in a half-wave to keep it warm, so you can reliably obtain hot water once it has been boiled, and the boiling control can also be used to prevent abnormalities inside the pot. It is possible to provide a boiling type electric kettle that can be used satisfactorily without creating a vapor pressure state.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of this invention, and FIG. 2 is a graph showing changes in pot water temperature in the same embodiment. 1... Commercial AC power supply, 2... First temperature-sensitive switch, 3... Heating heating element, 4...
...Diode, 5...Temperature-sensitive reed switch,
6... Heating element for heating and heat retention, 1... Timer motor, 8... Timer contact.

Claims (1)

[Scope of utility model registration request] An AC power source, a heating element with a relatively large heat value connected to this power source via a first temperature-sensitive switch, and a relatively high-temperature heating element connected to the power source via a diode and a second temperature-sensitive switch in series. A heating element for heating and keeping warm with a small calorific value,
a timer motor connected in parallel to the first temperature-sensitive switch; and a timer contact driven to open and close by the timer motor connected in parallel to the series circuit of the diode and the second temperature-sensitive switch; The temperature-sensitive switch 1 opens when the water temperature in the pot reaches a preset relatively high first temperature level, and once opened, the temperature-sensitive switch 1 opens.
The second temperature-sensitive switch is set so that it will not close unless the temperature of the water in the pot falls below a second temperature level that is sufficiently lower than the temperature level of The timer motor is set to open when the temperature is above a set heat retention level and close when the temperature drops below the heat retention level, and the timer motor contacts the timer contact for a time sufficient for the water temperature in the pot to boil after energization is started. A boiling type electric kettle characterized by being set to close and then hold open.