JPS60142821A - Boiling type electric pot - 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] This invention relates to a starvation type electric pot, and more specifically, an electric pot that heats water at a predetermined temperature below the boiling point after making water for a predetermined period of time. This invention relates to a boiling water type electric kettle equipped with an empty cooking prevention function.

<Prior Art> As shown in FIG. 4, for example, conventional electric pots have a main heater (9G), a thermostat (97), and a temperature fuse (73) between both terminals of a commercial AC power source (70). ) are connected in series, and a series circuit of a heat retention heater (98) and a heat retention thermostat (99) is connected in parallel with the thermostat (97),
The thermostat (97) is turned on and the main heater (9) is turned on until the water temperature inside the electric bottle reaches 94-96℃
By energizing only G), the water temperature is rapidly raised,
After the temperature reaches 94-96℃, mainly heat retention heater (98)
This prevents the water temperature from dropping due to heat generation.

An electric kettle with such a configuration has the advantage of being able to maintain the temperature of the water at a predetermined humidity close to the boiling point after a predetermined period of time has passed, but the water never reaches the boiling point. However, since it does not boil, chlorine odor, chlorine odor, etc. are not completely removed, especially when the water is kept warm, and there are also problems such as a feeling of dissatisfaction with water that does not boil due to the lifestyle habits of the person who installed it. .

Recently, in order to solve such problems, a boiling water heater (5), a timer switch (102), and a temperature fuse (73) have been installed between both terminals of a commercial AC power supply (70), as shown in FIG. ) are connected in series and a timer motor (101) that drives a timer switch (102).
), and a thermostat that turns on when it detects a temperature close to the boiling point.The direct IJ circuit of (ioo) is connected in parallel with the boiling water heater (5), and the moisturizing circuit (74) is connected in parallel with the timer switch (102). At the initial stage of heating, only the boiling water heater (5) is energized to rapidly raise the water temperature, and after reaching a temperature close to the boiling point, thermostats 1 to 1 are connected.
(100) is turned ON to energize the timer motor (101), and continues to energize the boiling water heater (5) until the timer motor (101) is activated for a predetermined period of time. And what happens after the timer motor (1oi) operates for a predetermined period of time? IIi thirst heater (5) and moisturizing circuit (i
By supplying electricity to 4), the temperature of the water is maintained at a predetermined temperature slightly lower than the boiling point. With an electric kettle of this kind of configuration, after boiling water for a predetermined period of time, it continues to be maintained at a predetermined temperature slightly lower than the boiling point, making it possible to completely eliminate chlorine odor, chlorine odor, etc., and eliminate any sense of dissatisfaction. However, after the boiling point is reached, heating by the boiling water heater is uniformly continued for a predetermined period of time, so for example, when only a small amount of water is in the electric kettle. Alternatively, if no water is added at all, the temperature of each component of the electric kettle may rise abnormally, and in the worst case, the electric kettle may be damaged.

Since such problems are likely to occur frequently in home kitchens, etc., they must be solved in order to put boiling water type electric bottles into practical use.

<Purpose> This invention was made in view of the above problems,
An object of the present invention is to provide a boiling water type electric kettle having a function of keeping water warm after boiling it and also having a function of preventing dry cooking.

<Structure> The structure of the boiling water type electric kettle of the present invention to achieve the above object is as follows: A control means is provided for energizing only the heater to generate heat until the liquid temperature reaches the boiling point and a predetermined time elapses thereafter, and a heat retention means for energizing only the heater and maintaining the liquid temperature at a predetermined value after the elapse of the heat generation time. Furthermore, when the internal temperature of the inner container reaches a predetermined temperature higher than the boiling point, a means to prevent dry cooking is installed to immediately cut off the electricity to only the heater. .

<Example> Hereinafter, an example will be described in detail with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view showing a boiling water type electric kettle.

(1) is the outer case, (2) is the inner container made of stainless steel, (3) is the pouring pipe, (4) is the discharge pipe, and (5) is the boiling water heater. (6) is a lid unit. The outer case (1) has a support (11) for supporting the inner container (2), a socket (13), and a thermistor (
82), a timer (17), and an inward flange (18) that supports the upper end flange (22) of the medium container (2). (23) is a lid whose upper end flange <24) is supported by the upper end flange (22) of the inner container (2) with a backing (22a) having an appropriate shape such as a cross section. The pouring pipe (3) is a pumping pipe (
33> and a supply pipe (34> located at the top of the lid (23))
The two pipes are communicated with each other by a connecting pipe (35) which has a water stop ball (3G) inside and has an air passage (37) passing through it vertically. Discharge pipe (
4) is the supply pipe (34) without intervening the auxiliary pipe (44).
The auxiliary pipe (44) is connected to the outer case (1) so as to be movable in the axial direction of the auxiliary pipe (44), and
It has a protrusion (46) that comes into contact with the protrusion (45) and prevents it from moving in the extraction direction, and by operating the knob (47> and forcibly pushing the protrusion (45) into the discharge pipe (
4) can be completely removed.

The auxiliary pipe (44) is screwed onto the top plate (19) of the outer case (1).

In addition, the lid unit (6) is equipped with a bellows type air pump (62
), a presser cover (65) for driving the bellows-type air pump (62), a spring (6G>) and a closing member (67), and a lock lever claw 3).

Figure 2 is an electrical circuit diagram, in which a boiling water heater (5) and a relay contact (72) Jl are connected between both terminals of a commercial AC power supply (70);
i and a temperature fuse (73) are connected in series, and a heat insulating circuit (74) as a heat insulating means is connected in parallel with the relay contact (72). Then, the commercial iQ power supply (70) is rectified by a diode (75), smoothed by a capacitor (76) and voltage regulator diodes 1 to 77, and made into a constant voltage to connect to a positive voltage terminal (78) J3. A ground terminal (79) is obtained, and a control stage and dry cooking prevention means are connected between both terminals.

The control means includes a comparator (84) to which an inverting input terminal voltage is applied by resistors (80) and (81), and a non-inverting input terminal voltage by a thermistor (82) and a resistor (83) as a temperature-sensitive resistance element. and resistance (85
) and a capacitor (8G), the inverting input terminal voltage is given by an integral delay circuit consisting of
A comparator (89>) to which a non-inverting input terminal voltage is applied by (88), a switching transistor (90) that performs switching using the output signal of the comparator (89) as input, and a relay coil (91) that drives the relay contact (72>). The output terminal of the comparator (84) is connected to a resistor (85).
and the connection point (92) between the capacitor (8G) and the capacitor (8G). Note that a negative characteristic thermistor is used as the thermistor (82). Therefore, when the temperature detected by the thermistor (82) is low, the comparator (84) outputs a low level signal, and the comparator 89 outputs a high level signal to energize the relay coil (91), thereby causing the relay coil (91) to be energized. By turning on the contact (72), the calorific value of the boiling water heater (5) is increased to rapidly raise the temperature of the hot water.

Also, when the temperature rises to a temperature close to the boiling point, the comparator (84) outputs a high level signal, so the resistor (8!
1) to charge the capacitor (86) through the connection point (9
2) voltage rises with a time constant determined by the resistor (85), capacitor (86), and capacitor, and after a predetermined time delay after the comparator (84) outputs a high level signal, the comparator (89) outputs a low level signal. output and relay coil (91
).

That is, even after the boiling point is reached, the water is boiled for a predetermined period of time by the heat generated by the boiling water heater (5), and thereafter the temperature of the water is maintained at a predetermined temperature slightly lower than the boiling point by the heat retention circuit (74).

The dry cooking prevention means is the output of a comparator tank 95 which is given an inverted input terminal voltage by the thermistor (82) and resistor (83) and given a non-inverted input terminal voltage by the resistor (93) and (94). A signal is connected to the heath terminal of the switching transistor (90). Therefore, when the temperature detected by the thermistor (82) reaches a predetermined temperature higher than the boiling point, the comparator (9
5) outputs a low level signal, the switching transistor 90) is forcibly turned off regardless of the operating state of the control means, and the relay contact (72) is turned off.
By doing so, empty cooking can be prevented. In this case, although not shown, it is preferable to remove an indicator such as an LED that lights up in response to the low-level signal output from the comparator (95), so that the dry cooking status can be indicated.

If you use a boiling water type electric pot with the above configuration, if you put enough water in the inner container to avoid operation, you can raise the temperature of the water to the boiling point, boil it for a predetermined period of time, and then boil the water. The temperature can be maintained at a predetermined temperature slightly lower than the boiling point, eliminating limescale odor,
The chlorine odor can be reliably removed and the user can feel satisfied. If the container is operated with only a small amount of water or no water at all, the detected temperature will continue to rise even after reaching the boiling point, but it will not rise until the specified temperature. Since it is forcibly switched to the warm state at this point, it is possible to reliably prevent dry cooking and eliminate the inconvenience of component parts being damaged by heat.

FIG. 3 is an electric circuit diagram showing another embodiment. The difference from the embodiment of FIG. (89) is omitted and the connection point (92) is directly connected to the base terminal of the switching 1 to transistor (90), and the output terminal of a3 and the fan plater (95) is connected to the switching 1 to transistor (90) and the relay coil ( 9
1), and the configuration of the other parts is the same.

Therefore, when the temperature +U detected by the thermistor (82) is low, the comparator (84) outputs an Il\ signal, so the base-emitter bias of the switching transistor (90) is large, and the relay coil (91)
) and quickly bring the water temperature up to 1! - Can be affected. Then, when the temperature reaches close to the t91 point, the comparator (84) outputs a high level signal and the capacitor (
86), so the switching transistor (
The base-emitter bias of the relay coil (90) gradually decreases, and after a predetermined period of time has elapsed, the relay coil (91) can be de-energized to perform a heat-retaining operation.

In addition, if a predetermined temperature above the boiling point is reached, the comparator (
95) outputs a low level signal, so the relay coil (
91) is drastically reduced, making it possible to forcibly perform the heat-retaining operation.

In other words, as in the actual Hg example shown in Figure 2, if there is a sufficient amount of water in the medium container, it is possible to rapidly raise the temperature to the boiling point, continue boiling water for a predetermined time, and then perform a warming operation. In addition, if there is only a small amount of water in the inner container or no water at all, it is possible to prevent dry cooking by detecting a predetermined temperature higher than the boiling point and immediately performing a warming operation. can.

However, in this case, the switching transistor (90)
Since the bias changes continuously, the responsiveness will be somewhat inferior, but this does not seem to be a particular disadvantage.

Note that the present invention is not limited to the above-described embodiments, and for example, a boiling water heater (5) may be used as the heat insulation circuit (74).
Use a circuit that reduces the amount of current applied to the
The heat retention heater (4) is connected in parallel with the boiling water heater (5), and the commercial AC power source (70) is selectively connected by the relay contact.
In addition, it is possible to connect the temperature-sensitive resistance element in the control means and the dry cooking prevention means separately without sharing them, and to install a thermostat in series with the humidity fuse to detect abnormal temperature rise. (However, in this case, it is possible to install a relatively large cap (requires no space and increases costs), and to detect water contention as capacitance and prevent dry cooking. , and other various design changes can be made within the scope of the invention.

<Effects> As described above, in this invention, after boiling water for a predetermined amount of time for one hour, the water is kept at a predetermined temperature slightly lower than the boiling point, so even if the temperature is d3 at the initial stage of heat retention, chlorine odor, chlorine odor, etc. are completely eliminated. In addition to being able to remove the boiling water, it also gives a sense of security and satisfaction that the boiling water is kept warm, and furthermore, if there is little or no water in the medium container, the boiling time can be reduced. Heat the inside! 'Because there is no such thing, Tochinari's various parts have abnormal stomach temperature,
Qin has the unique effect of effectively eliminating the inconvenience of being damaged.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view showing an embodiment of a boiling water type electric kettle;
FIG. 2 is an electrical circuit diagram showing one embodiment of the same as the above, FIG. 3 is an electrical circuit diagram showing another embodiment of the same, and FIGS. 4 and 5 are electrical circuit diagrams showing a conventional example. (1)...Outer case, (2)...Inner container, (5)
. . . Boiling water heater, (74) . . . Heat retention circuit as heat insulation means, (72) . . . Relay contact forming control means, 82) . . . Thermistor forming control means, <8
4> (89)...Comparator constituting the control means, (90)...47. ；Switching transistor, (8!i)... Resistor forming the delay circuit, (8G)... Capacitor forming the delay circuit,
(95)...Comparator constituting dry cooking prevention means.

Claims (1)

[Claims] 1. In an electric kettle having an inner container inside an outer case and a heater for heating liquid at a predetermined position, the heater is used only until the temperature of the liquid reaches the boiling point and until a predetermined period of time has passed thereafter. A control means for energizing and generating heat is provided, and a heat-retaining means is provided for energizing only the heater and maintaining the temperature of the liquid at a predetermined value after the heating time has elapsed, and furthermore, the internal temperature of the inner container reaches a predetermined temperature higher than the boiling point. This starvation-type electric kettle is characterized by being provided with a dry-heating prevention means that immediately cuts off the power supply only to the heater upon detecting that the heater has been heated. The boiling water type electric kettle according to claim 1, wherein a boiling point detection signal for stopping energization and heat generation is delayed for a predetermined period of time by a delay circuit. 3. The 191i hot water type electric pot according to claim 1, wherein the heat retaining means energizes a heat retaining heater provided separately from a heater for heating the liquid. 4. The starvation type electric kettle according to claim 1, wherein the heat retaining means changes the amount of light of a heater for heating the liquid. 5. The dry heating prevention means detects a predetermined temperature higher than the boiling point by a change in the resistance value of the temperature-sensitive resistance element, and immediately stops the energization and heat generation of only the heater. Starvation type electric pot.