JPS638774B2 - - Google Patents

Description

Detailed Description of the Invention Object of the Invention (Field of Industrial Application) The present invention is a novel electric heating jar (electronic heating jar) that can control not only the temperature but also the humidity when keeping food warm. (including).

(Prior art and its problems) The conventional electric heat retaining jar directly or indirectly detects the temperature of the rice stored in the inner container, automatically adjusts the amount of heat generated by the heater according to this detection signal, and It was designed to keep the rice at an appropriate temperature.

However, it is impossible to properly maintain the humidity of the rice in the inner container only by controlling the temperature as described above. As a result, the upper layer of the rice would turn yellowish brown and become dry and hard, or on the other hand, it would become white, soggy and sticky. Needless to say, such rice is inferior from the viewpoints of taste, sight, and smell.

The present invention was made in view of the above circumstances, and it controls the temperature and humidity of rice to maintain the taste, visual and olfactory state of the rice for a long period of time. The purpose of the present invention is to provide a new electric heat-retaining jar (hereinafter referred to as the "Jar") equipped with a humidity sensor that can keep you warm throughout the day.

"Structure of the Invention" (Means for Solving Problems) The gist of the jar is that a humidity sensor is provided facing the space above the food stored in the inner container; It is equipped with a humidity control circuit that controls the heating amount of the heater of the heater circuit according to the change, and the heater circuit includes an upper heat retention heater for heating the upper half of the inner container and an upper heat retention heater for heating the lower half of the inner container. The main point is that a lower heat retention heater is provided for this purpose.

(Function) The humidity sensor detects the humidity in the space above the rice stored in the inner container, and sends this detection signal to the heater circuit. Therefore, the calorific value of the upper heat retention heater or the lower heat retention heater provided in the heater circuit is adjusted, and the temperature distribution between the upper half and the lower half within the inner container is controlled. For a little while now,
This will be explained in detail. When looking at the relationship between temperature and humidity changes in the upper and lower halves of the inner container, if the temperature in the upper half is higher than the lower half, the humidity in the upper half is higher than in the lower half. Conversely, if the temperature in the upper half is lower than the lower half, the humidity in the upper half is higher than in the lower half. That is, temperature changes and humidity changes are inversely proportional to each other. Therefore, if the humidity in the upper space above the rice in the inner container falls below the appropriate value, adjusting the voltage applied to the heater to raise the temperature in the lower half will reduce the humidity in the upper space. can be raised. On the other hand, when the humidity in the upper space exceeds the appropriate value, the humidity in the upper space can be lowered by adjusting the voltage applied to the heater to increase the temperature in the upper half.

(Example) The present invention will be described below based on drawings showing examples thereof.

FIG. 1 is a front sectional view showing the jar.
The jar is equipped with a humidity sensor 9 facing the space X above the rice 8 stored in the inner container 7, and the humidity sensor 9 is connected to a heater circuit as shown in FIG. Humidity control circuit 27
(encircled by a two-dot chain line). In the same figure, the parts other than the humidity control circuit 27 are collectively referred to as a heater circuit.

First, the structure of the jar main body 1 will be explained.
The jar main body 1 is composed of a double-walled circumferential wall 4 and a bottom wall 6 containing a heat insulating material, and is capable of housing an inner container 7 therein. An upper heat-retaining heater 2 is provided within the peripheral wall 4 on the lower surface of the upper shoulder portion 5. Furthermore, a temperature control element 24 such as a thermal reed switch is installed at approximately the center height position inside the peripheral wall 4 to adjust the voltage supplied to the upper heat retention heater 2 according to temperature changes within the inner container 7. There is. A lower heat retaining heater 3 is provided in the center of the bottom wall 6. An outer lid 11 with a handle 25 is attached to the upper part of the jar body 1 so as to be openable and closable. On the back wall 11a of the outer cover 11, a one-touch pin 10 is vertically provided at the center thereof. The one-touch pin 10 suspends the inner lid 12.

FIG. 2 is an enlarged sectional view showing the mounting structure of the one-touch pin 10. One touch pin 10
has an upward stepped portion 13a formed on its outer circumferential surface on its upper end side, and a male screw 15 is formed on its outer circumferential surface further above the upward stepped portion 13a. Therefore, the one-touch pin 10 is fixed to the outer cover 11 through the mounting hole 16 bored in the center of the back wall 11a of the outer cover 11.
This is done by inserting the male screw 15 into the interior from below, inserting the washer 18 into the male screw 15 protruding upward from the back wall 11a, and screwing the nut 17 together. The humidity sensor 9 described above is provided inside the one-touch pin 10.

The pin body 13 of the one-touch pin 10 has a hollow hole Z formed therein. Also, the pin body 13
A hemispherical bulge 10a is attached to the lower end of B to prevent the inner lid 12 from falling off, and a cavity Y is formed inside the bulge 10a.
Further, the bulging portion 10a has ventilation holes 22, 22,...
are bored, and the atmosphere inside the cavity Y and the atmosphere inside the upper space X communicate with each other through the ventilation holes 22, 22, . Humidity sensor 9
The detection part is housed in the cavity Y of the bulging part 10a, and the lead wire 23 is housed in the hollow hole Z of the pin body 13.
is inserted. FIG. 3 is a diagram showing a connection circuit between the heater circuit of the present jar and the humidity control circuit 27 (encircled by a two-dot chain line) in which the humidity sensor 9 is incorporated. The outline is as follows: Temperature control element 2
4 and the upper heat retention heater 2 are connected in parallel to the series part of the lower heat retention heater 3 and the humidity control circuit 27.

The humidity control circuit 27 mainly consists of the humidity sensor 9. As shown in the graph of FIG. 5, the characteristics of the humidity sensor tend to be such that the resistance value decreases as the humidity increases, and the resistance value tends to increase as the humidity decreases. The humidity sensor 9 is connected in parallel with a capacitor 26 as shown in FIG. 3, and a triac 25 is connected to its primary side via a trigger diode 28. The triax 25 is connected in series with the lower heat retaining heater 3. The trigger diode 28 is
A positive pulse or a negative pulse is generated when the input exceeds the breakover voltage (breakdown voltage).
Further, the triax 25 is a type of thyristor, and is a bidirectional thyristor that emits a trigger signal in response to either a positive pulse or a negative pulse gate current. Incidentally, the reference numeral 29 in the figure is a heat-retaining lamp, and R1, R2, and R3 are resistors.

The operational status of the jar constructed in this way will be explained. Assume now that cooked rice 8 is stored in the inner container 7 as shown in FIG. Assume that the outer cover 11 is opened once and then immediately closed. With this operation, as shown in Figure 6,
The temperature in the upper half of the inner container 7 drops all at once. Moreover, since the water vapor contained in the air in the upper space X above the rice 8 is diffused into the atmosphere, the humidity in the upper space X also decreases at the same time, as shown in FIG. When the humidity in the upper space X decreases, the resistance value of the humidity sensor 9 increases as shown in FIG. Therefore, as shown in FIG. 3, the capacitor 26 connected in parallel with the humidity sensor 9 is charged. When the charging voltage on the capacitor 26 exceeds the breakover voltage of the trigger diode 28, the trigger diode 28 emits a positive pulse or a negative pulse.
The conduction angle (duration time of the ON state) of the triax 25 becomes longer. As a result, the voltage applied to the lower heat retention heater 3 connected in series with the triac 25 increases, and the amount of heat generated therefrom also increases. In this way, the humidity control circuit 27 controls the heating amount of the lower heat retaining heater 3 using the humidity sensor 9, and the temperature of the lower half of the inner container 7 increases. Humidity in the upper half, including the However, if the temperature in the lower half continues to rise, the temperature control element 24 will detect an abnormal temperature rise.
It is in the OFF state, and power supply to the upper heat retention heater 2 is stopped. This state continues further and the upper space
If the temperature drops too much, the temperature control element 24 is turned on again.
It becomes ON and this operation is repeated from then on. In this way, the temperature and humidity of the rice in the inner container 7 are always maintained at an appropriate level. Note that if the humidity in the upper space X increases abnormally, the resistance value of the humidity sensor 9 decreases, so the capacitor 26 is not charged, the trigger diode 28 and the triac 25 do not operate, and the lower heat insulation heater 3
The voltage applied to remains low. Therefore, the ON state of the temperature control element 24 continues for a long time, and the heat generation by the upper heat retention heater 2 continues. In this way, the humidity control circuit 27 and the humidity sensor 9 control the heating amount of the upper heat retaining heater 2, so that the temperature of the upper half of the inner container 7 including the upper space X increases, and the humidity decreases. I come to do it.

In this embodiment, as shown in FIG. 2, the humidity sensor 9 is attached to the one-touch pin 10 of the outer lid 11, so a special mounting structure for the humidity sensor 9 is not required, and the humidity sensor 9 is attached to the inner container 7. It has advantages such as being positioned at the center of the upper space X of the air, which provides accuracy in detecting humidity. As shown in FIG. 2, a bowl-shaped packing 21 is inserted through the pin body 13 of the one-touch pin 10. Further, a donut-shaped elastic bushing 19 is forcefully fitted into the center hole 20 of the inner lid 21. Therefore, when the outer lid 11 is closed to the jar main body 1 as shown in FIG. 1, the inner lid 12 is pressed against the bowl-shaped packing 21 and the inner container 7 is hermetically sealed. When the outer cover 11 is opened, the inner cover 12 is engaged with the bulge 10a of the one-touch pin 10 and suspended. Further, in this state, if only the inner cover 12 is strongly pulled, the inner cover 12 can be removed from the outer cover 11.

(Study of Alternative Aspects) In the above embodiment, the humidity sensor 9 was attached to the one-touch pin 10 of the outer lid 11, but the humidity sensor 9 was attached to the peripheral edge 12a of the inner lid 12 (see FIG. 1).
etc., it may be provided so as to face the upper space X of the inner container 7. Further, for the humidity control circuit 27 mainly including the humidity sensor 9, another embodiment as shown in FIG. 4 can be considered.

Humidity control circuit 31 shown surrounded by a two-dot chain line in Fig. 4
is connected in series with the upper heat retention heater 2. That is, unlike the above embodiment, the humidity sensor 9
The voltage applied to the upper heat-retaining heater 2 is adjusted by changing the electrical resistance of the upper heat-retaining heater 2. Further, the lower heat retaining heater 3 is configured to be energized or disconnected by a temperature control element 24. The humidity control circuit 31 includes a humidity sensor 9 and a capacitor 26 connected in series, and also includes a humidity sensor 9 and a capacitor 26 connected in series.
A thyristor 30 is connected to the secondary side of the thyristor 30 via a trigger diode 28. The thyristor 30 is connected in series with the upper heat retention heater 2.

In this embodiment, if the humidity in the upper half of the inner container 7, including the upper space X, decreases, the resistance value of the humidity sensor 9 will increase. The capacitor 26 is not charged. Therefore, no pulse is emitted from the trigger diode 28 to the thyristor 30, and the conduction angle of the thyristor 30 remains small. Therefore, the voltage applied to the upper heat retention heater 2 is low and the amount of heat generated is small, so the inside of the inner container 7 is
The temperature of the lower half is higher than that of the upper half. As a result, the humidity in the upper half including the upper space X increases. On the other hand, if the humidity in the upper half including the upper space X increases abnormally, the resistance value of the humidity sensor 9 will decrease, so the capacitor 26 will be charged.
A pulse is emitted from trigger diode 28 to thyristor 30 . Therefore, the conduction angle of the thyristor 30 becomes longer, and the voltage applied to the upper heat retention heater 2 also increases. That is, the amount of heat generated by the upper heat retention heater 2 increases, and the temperature in the upper half of the inner container 7 becomes higher than that in the lower half, and the humidity in the upper half decreases.

In yet another aspect, in the humidity sensor,
It is possible to use a material whose resistance value increases as the humidity increases. Also, capacitor 2
6 and the trigger diode 28 can be replaced with an on/off control circuit with zero cross switching for noise prevention. In this way, the configuration and shape of the jar can be changed as appropriate depending on the embodiment.

"Effects of the Invention" As is clear from the above explanation, according to the electric heat-retaining jar with a humidity sensor according to the present invention, there is no possibility that rice will be deteriorated in terms of taste, sight, and smell even if it is kept for a long time. You can enjoy delicious rice forever. In addition, since there are no mechanically moving parts for controlling temperature and humidity, it has excellent advantages such as being less likely to break down.

[Brief explanation of the drawing]

The drawings all show the subject jar, with Fig. 1 being a front sectional view, Fig. 2 being an enlarged sectional view showing the mounting structure of the humidity sensor, and Fig. 3 showing the case where the heater circuit and humidity sensor are installed. Fig. 4 is a diagram showing a connection circuit of another embodiment, Fig. 5 is a graph showing the relationship between humidity and resistance value in a humidity sensor, and Fig. 6 is a diagram showing a connection circuit with an outer lid. A graph showing the temperature change inside the inner container when the inner container is opened and closed, and FIG. 7 is a graph showing the same humidity change. 1... Jar main body, 2... Upper heat retention heater,
3...Lower heat retention heater, 7...Inner container, 9...
Humidity sensor.

Claims (1)

[Claims] 1. A humidity sensor is provided facing the space above the rice stored in the inner container, and the humidity sensor is equipped with a humidity control circuit that controls the heating amount of the heater of the heater circuit according to changes in humidity, The electric heat retaining jar with a humidity sensor is characterized in that the heater circuit is provided with an upper heat retaining heater for heating the upper half of the inner container and a lower heat retaining heater for heating the lower half of the inner container. .