JPS6114418B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooking device, and its purpose is to improve the taste of food by skillfully heating it.

In conventional cooking appliances, such as microwave ovens and electric cooktops, the cooking time corresponding to the type and amount of food is displayed on the control panel, and the user can enter the name and amount of food to be cooked from the control panel. The cooking time is now set based on the selected ingredients and guidelines.

However, the cooking time indicated on the operation panel is just an average cooking time obtained through experimentation, and it often does not correspond to actual cooking and results in failure of the cooking.

To give an example of this, the desired temperature of food varies greatly depending on the storage location, season, etc., and if the cooking time is set while ignoring this desired temperature, the finished product will naturally vary greatly.

Therefore, the present invention attempts to eliminate the above-mentioned drawbacks by detecting the humidity that changes as food is heated, and switching the heating output when this humidity reaches a predetermined value.

Now, to explain this in a little more detail, the amount of water vapor released from food increases rapidly when the temperature of this food reaches a certain value, so the first cooking time up to this point and this first cooking The total cooking time is obtained by adding the second cooking time, which is the time multiplied by a constant specific to each type of food.

In other words, the amount of water vapor increases rapidly like this when the surface temperature of the food reaches an appropriate temperature, so this is the first cooking time, and the rest is determined by the type of food during this first cooking time. It is heated for the second cooking time multiplied by a constant.

In this case, if the food is, for example, a meat dish, it is initially heated over high heat, and then when the surface temperature of the meat reaches a predetermined value, it is switched to low heat and heated so that the surface does not become charred and the inside is sufficiently heated. Ru. Conversely, in the case of cooked rice, the gelatinization temperature of starch (approximately 65℃)
By increasing the time it takes to reach this point, the water shortage in the center of the rice is eliminated, resulting in cooked rice that ages slowly.

Therefore, in the present invention, the heating output during the first cooking time and the heating output during the second cooking time are made to be different.Hereinafter, one embodiment of the present invention applied to an electric range will be explained based on the attached drawings. do.

As shown in FIG. 1, the humidity change when food is heated by microwaves generally shows a significant increase in humidity value after a certain period of time with a different slope than before. The heating state of the food when this remarkable increase in humidity value appears is close to when the surface temperature of the food reaches the optimum temperature. However, the internal temperature varies depending on the type of food, and some have reached the optimum temperature, while others have not yet reached the optimum temperature if the amount of frozen food is large. Therefore, it can be seen that after this significant rise in humidity value, it is only necessary to heat the food for a time determined by the amount and type of the cooked food. Therefore, the total cooking time T ₀
If T ₁ in Fig. 1 is the first cooking time, then the second cooking time is added to the first cooking time T ₁ as shown in the following equation ().
It is the sum of the cooking time T ₂ .

T ₀ = T ₁ + T ₂ ...(I) In this case, the first cooking time T ₁ is a value that already includes the influence of the amount and type of food, so the amount and type need to be newly considered. There isn't.

However, the second cooking time T ₂ is the first cooking time T ₁
Since it is determined by the type of food, if K is a constant specific to food, the following equation () is obtained.

T ₂ = KT ₁ ...() Therefore, the total cooking time T ₀ is the above (), ()
The expression becomes the following expression ().

T ₀ =T ₁ +T ₂ =T ₁ +KT ₁ =(1+K)T ₁ () Note that the T _A point in FIG. 1 was determined as shown in FIG. 2.

In other words, the point where the humidity h increases by Δh from the initial humidity hi [hi≒hmin] is determined as the above T _A point.The reason for this is that the initial humidity hi easily changes depending on the ambient temperature and humidity, and the change This is because higher accuracy can be obtained by handling.

Figure 3a shows the relationship between cooking time and microwave output, that is, heating output, when approximately 900 dl of meat is cooked.

In this case, the initial temperature of the meat is 5 (℃), and if the initial output P ₁ is 700 (W), the first cooking time T ₁ is 6
It took (minutes). Further, in the second cooking time _T2 , the microwave was intermittent and the output was set to 200 (W) [this is 30 to 40 (%) of the output _P1 ], so the constant K of the meat was 5.

Therefore, by substituting this constant (K=5) into the above equation (), it is clear that the total cooking time T ₀ is 36
(minutes). Figure 3b shows the changes in the surface temperature and internal temperature of the meat over time during cooking, where O _S is the surface temperature at the end of the cooking time, and O _C is the temperature at the end of the cooking time. is the internal temperature. In this case, the internal temperature O _C is 75 (℃) to 85 at the end of heating.
It is best to keep the temperature at around (°C), as if heating continues beyond that temperature, carbonization and dehydration will occur inside the tank. Therefore, the constant K unique to the food product was set to 5 as described above so that the final internal temperature was between 75 (°C) and 85 (°C).

Furthermore, as is clear from Fig. 3 a and b, in the second cooking time _T2 , the surface of the meat is hardly heated any further in order to reduce the output.
Only the inside will gradually heat up.

For this reason, the surface will not be heated too much and become carbonized, or the inside will not become half-cooked due to concerns about carbonization.

Of course, if you are only concerned about the raw inside of the meat, you could consider heating at low power from the start to the end of cooking, but this would not only lengthen the cooking time, but also cause the meat juices to leak out from the inside, resulting in a bad taste. I get used to it.

On the other hand, taking boiled rice as an example, the heating output is switched as shown in FIG. 4, unlike the above-mentioned meat cooking example.

In other words, it is said that cooked rice tastes better if it is heated to the so-called ``warm at the beginning and sizzling in the middle.'' Therefore, the first cooking time T ₁ up to the above point T _A is heated at low power, and the next second cooking time T ₂
Then, the low output was switched to a high output of 140 to 150 (%) and heated.

As a result, the time required for the starch to reach its gelatinizing temperature (approximately 65 degrees Celsius) was increased, and the lack of water in the center of the rice was resolved, resulting in rice that stagnated slowly.

FIG. 5 shows a specific configuration of the present invention.
The operation will be explained using FIGS. 1 to 4.

In FIG. 5, 1 is a transformer for driving the magnetron 2, and 3 and 4 are capacitors and diodes constituting a voltage doubler circuit. 5 is a heating chamber, 6
is food heated by microwaves emitted from magnetron 2. Moreover, the air 7 containing water vapor generated from the food 6 as a result of microwave heating in this manner is exhausted from the exhaust port 8 . A humidity sensor 9 is provided in the exhaust passage of the exhaust port 8.
is installed, and the voltage across a resistor 10 connected in series to this humidity sensor 9 is used as a humidity detection signal. Note that 11 is a standard signal source, 12 is an amplifier, 13 is a minimum value detection and holding circuit, and 14 is a subtraction circuit for detecting the humidity increase Δh from the minimum value.
A signal C proportional to B) is output. Corresponding to FIGS. 1 to 4, A is the changing humidity signal h, B is the lowest value hmin, and C is Δh. In addition, 15 in FIG. 5 is a voltage comparison circuit, which compares the above signal C with the reference voltage Vh, and C indicates Vh.
Generates an output signal when the This time is
This is point T _A in FIGS. 1, 2, and 4.

16 is a controller, which includes a timer driven by the output signal of the voltage comparator circuit 15 and has a running time;
Turns on the power supply when cooking starts and stops
- Contains the drive circuit for the contact 17 that turns OFF. Further, STA is a cooking start signal, and when this signal STA is input, the contact 17 closes, and thereafter, when the above-mentioned total cooking time T ₀ =(1+K)T ₁ has elapsed, the contact 17 opens.

That is, when cooking starts in this circuit, the food 6 is heated by microwaves generated from the magnetron 2, and the humid air 7 is exhausted. This air 7 is detected by a humidity sensor 9,
The controller 16 operates a timer in the controller 16 when the increase in humidity from the lowest value exceeds Δh, and after the second cooking time T ₂ has elapsed, the contact 17 is activated.
Open and stop heating.

The contact 18 is used to switch the heating output supplied to the food 6 by opening and closing periodically, and the period thereof is controlled by the controller 16.

As described above, the present invention switches the heating output when the humidity that changes with heating reaches a predetermined value, so the surface of the food is overheated and becomes carbonized, or the inside is underheated and becomes undercooked. You can cook well without the juices leaking out from inside and causing the taste to deteriorate.

In addition, there is no need to keep the heating output low because of concerns about carbonization on the surface of the food or undercooking of the inside, and the total cooking time is therefore shortened.

Furthermore, even if there is some uneven heating, by detecting the change in humidity that occurs from the highest temperature part, it is possible to reliably detect heating, and it is also possible to directly detect the process from frozen food to complete cooking. can also be cooked consistently. After detecting humidity, by switching and controlling the heating output, it is possible to control the heating output in accordance with the cooking science characteristics of each individual food, such as rice cooking, meat dishes such as roast beef, and even stewed dishes. The best results can be expected for many types of cooking with different cooking processes, that is, for dishes where it is preferable to switch from high output to low output, and for dishes where it is preferable to switch from low output to high output.

[Brief explanation of the drawing]

1, 2, 3a, 3b, and 4 are graphs explaining the operation of a cooking appliance according to an embodiment of the present invention, and FIG. 5 is an electric circuit diagram of the cooking appliance. 6...Food, 9...Humidity sensor.

Claims (1)

[Claims] 1. A heating chamber for accommodating an object to be heated, a heating means for supplying heating output such as microwaves into the heating chamber, a counting means for counting the operating time of the heating means, and a heating chamber provided in an exhaust passage from the heating chamber. The signal from the detected humidity detection means is added during a first heating time until it reaches a predetermined value and a second heating time obtained by multiplying the first heating time measured by the counting means by a constant specific to the object to be heated. 1. A cooking appliance characterized in that the heating means is controlled by heating the food at a constant temperature, and controlling the heating means by making the heating output during the first heating time and the heating output during the second heating time different.