JPH0518016B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an automatic high-frequency heating device that can be used when defrosting and cooking frozen foods in a high-frequency heating device such as a microwave oven.

Prior Art In general, thawing of frozen foods by microwave heating is completed in an extremely short time, resulting in good quality after thawing, and has been put to practical use more widely than ever before.
Here, we will talk about the so-called thawing cooking method, which involves heating frozen cooked foods and frozen vegetables such as Mitsu Vegetables as they are, to raise the temperature of the food.

Conventionally, such defrosting cooking methods generally involve heating with a constant high-frequency output from defrosting to cooking. Then, using a cooking sensor such as a humidity sensor or a gas sensor, it detects when the heating of the food is completed and automatically ends the cooking. This thawing cooking method requires less heating time, but on the other hand, cold spots tend to appear in the center of the food, and homogeneity is impaired in areas that begin to melt early and areas that begin to melt slowly, resulting in a mushy finish. I had a problem where I felt like I was getting angry.

In order to improve the above-mentioned problems, a structure has been proposed in which thawing and cooking are automatically performed sequentially (Japanese Patent Application No. 114970/1982). In this system, the first half of defrosting is controlled by a weight sensor, and the second half of cooking is controlled by a gas sensor, and the defrosting is divided into four small modes to improve the defrosting quality.

Problems to be Solved by the Invention However, in such a thawing cooking method, two sensors, a weight sensor and a cooking sensor such as a gas sensor, must be provided, making the control system large-scale and expensive. There's a problem.

The present invention solves these conventional problems and provides an automatic high-frequency heating device that can sequentially perform thawing and cooking using only a single sensor.

Means for Solving the Problems The automatic high-frequency heating device of the present invention includes a gas sensor that detects at least water vapor generated from an object to be heated, and a control unit uses this gas sensor to sequentially heat the object to be heated. It is something.

Function The automatic high-frequency heating device of the present invention first performs heating from thawing to halfway through cooking using a certain high-frequency output.
When the detection value of the gas sensor reaches the first threshold, the high frequency output is subsequently reduced and heating is carried over for a predetermined time or a time based on the detection time, and then the high frequency output is increased again and the cooking sensor is heated. until the detected value reaches a second threshold value that is equal to or greater than the first threshold value.
Heat food.

By the above sequential heating, thawing and cooking can be performed uniformly in a short time.

Embodiment An automatic high-frequency heating device according to an embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the automatic high-frequency heating device according to the present invention includes a main body 1 containing a heating chamber, a door body 2 that freely opens and closes the opening of the heating chamber, and an operation panel 3 that inputs various commands. It is formed by A thawing/cooking key 4 is arranged on the operation panel 3 for instructing thawing/cooking of frozen food.

FIG. 3 is a block diagram showing one embodiment of such an automatic high-frequency heating device. Commands input from the thawing/cooking key 4 on the operation panel 3 are decoded by the control section 5. Then, the control unit 5 starts defrosting and cooking the frozen food, which is the object to be heated 7 placed in the heating chamber 6 . Heating is controlled by supplying power to a magnetron, which is a high frequency generating means 9, through a driver 8.

The object to be heated 7 is placed on the placement plate 10 . The gas sensor 11 is realized by a humidity sensor, a gas sensor, or the like, and reacts to the steam and gas discharged by the fan 12 to detect the point in time when the object to be heated 7 is heated and begins to generate steam and various gases. 13 is an exhaust guide, 14 is a detection circuit, and 15 is a motor that rotates the mounting plate 10 to improve heating unevenness.

As the gas sensor 11, Matsushita Electric's relative humidity sensor "Neo Huyumi Ceram", absolute humidity sensor "Neo Huyumi Ceram", gas sensor #813 of Figaro, etc. can be used.

FIG. 1 is a heating pattern for thawing cooking showing an embodiment of the present invention. FIG. 1a shows the microwave output, FIG. 1b shows the temperature rise of various parts of the food being heated, and FIG. 1c shows the amount of steam generated from the food being heated.

Heating consists of three modes. First, in T ₁ , the microwave is heated at full power, and when a predetermined amount of steam △h ₁ is detected by the cooking sensor, the next mode is T ₂ .
mode. In _T1 mode, the temperature of frozen food is raised all at once, reaching a temperature of 40 to 60 degrees Celsius partially on the surface. At this time, the internal temperature of the food is still -2 to -3℃.
In this state of temperature unevenness, the system shifts to T ₂ mode.

In _T2 mode, the microwave power is reduced to about 180 watts and carryover heating is performed. The T ₂ time continues for a certain period of time, for example, 3 minutes, or is calculated based on the T ₁ time and multiplied by a constant. In other words, T ₂ =C (C: constant) or T ₂ =K ₂ T ₁ (K ₂ : constant). The latter method allows you to calculate the optimal carryover heating time depending on the amount of food.

In T ₂ mode, the temperature difference between the surface and the inside is large, so the temperature moves quickly, and at the end of T ₂ mode, the frozen part inside is completely thawed.
The power in T ₂ mode may be just a rest, but
By using a low output of about 90 to 250 watts as in this embodiment, the total heating time can be shortened. With this level of output, there is not enough energy to further advance the boiling process, but it is effective in defrosting the inside (see Figure 1b).

When the T ₂ time has elapsed, the microwave power is switched to full power again, and heating continues until a predetermined amount of steam Δh ₂ is detected by the cooking sensor.

At this time, since △h ₁ < △h ₂ , it is possible to shift to the T ₂ carryover heating mode without significantly increasing the surface temperature of the frozen food in the T ₁ thawing mode, and to raise the temperature of the food sufficiently in the T ₃ cooking mode. It can be warmed up. It is also effective to apply additional heat after △h ₂ is detected, and in this case, the additional heat time is calculated by multiplying the T ₃ time by a certain constant.

T ₄ =K ₃ T ₃ (K ₃ : constant) Finally, the control flowchart of the microcomputer, which is the control section, is shown in FIG. 4 and will be explained. First, the input of the thawing cooking key is decoded (4A), various flags are reset, and counters are initialized (4A).
B).

Next, when the start key input is decoded (4
C), the microwave is turned on (4D) and the _T1 flag is set (4E). The clocks are counted sequentially, and when 1 second has passed (4F), the _T1 time is added after checking the _T1 flag (4G) (4F).
H), it is monitored whether the amount of steam generation has reached a first threshold Δh ₁ (4I). Then, the T ₁ time is added up until detection, and the T ₂ time is calculated by detection (K ₂ T ₁ = T ₂ ) (4J), the T ₁ flag is reset (4K), and the T ₂ flag is set. (4L), transition to T ₂ mode.

When the _T2 mode processing routine is entered by checking the _T2 flag (4M), microwave on/off control is first performed (4N). Then, the T ₂ time is subtracted (4O), and it is checked whether the T ₂ time has elapsed (4P).

After the T ₂ time has elapsed, the T ₂ flag is reset (4Q) and the microwave is turned on again (4Q).
R), full power. Then it shifts to _T3 mode.

In _T3 mode, the HUM flag is checked first (4
S), this is not set at first, so while adding _T3 time (4T), set the second threshold △
It is checked whether more than _h2 steam has been generated (4U).

If a humidity change of △h ₂ or more is detected, here
The HUM flag is set (4V) and additional heat time _T4 is calculated (4W).

When the HUM flag is set, there will be additional heat control and the _T4 time will be reduced (4X).
Eventually, the T ₄ time counts up (4
Y), the power is turned off (4Z), and cooking ends.

As described above, according to the thawing cooking sequence of the present invention, homogeneous heating with a small temperature difference between the surface and the inside can be achieved.

Effects of the Invention As described above, the automatic high-frequency heating device of the present invention has
Equipped with a gas sensor, the food is first heated at high output from thawing to halfway through cooking, and when the detection value of the cooking sensor reaches a predetermined threshold, it is then heated at low output for a predetermined time or a time based on the detection time,
Next, the food is cooked again at high output, and the cooking sensor is used to heat the food until the detected value reaches a threshold value larger than the threshold value, and the gas sensor does not require the use of a weight sensor. Sequential thawing and cooking can be carried out using only a single step, and homogeneous heating with small temperature difference between the surface and inside can be achieved.

[Brief explanation of drawings]

FIG. 1 is a time chart showing a heating pattern of an automatic high-frequency heating device in an embodiment of the present invention;
FIG. 2 is a perspective view of the main body, FIG. 3 is a block diagram showing the configuration, and FIG. 4 is a control flowchart of a microcomputer as a control section. 4... Thawing cooking key, 5... Control unit, 6... Heating chamber, 7... Item to be heated, 9... High frequency generation means,
11...Cooking sensor.

Claims (1)

[Claims] 1. A heating chamber in which an object to be heated is placed, a high frequency generating means coupled to this heating chamber, a control unit controlling power supply to the high frequency generating means, and detecting water vapor or gas generated from the object to be heated. The control unit includes a gas sensor and a key for instructing defrosting and cooking of frozen food, and when the key is operated, the control unit performs the process from defrosting to halfway through cooking using a certain high frequency output, and when the detected value of the gas sensor is When the threshold value is reached, the high frequency output is subsequently reduced and heating is carried over for a predetermined time or a time calculated based on the detection time, and then the high frequency output is increased again and the detection is performed using the gas sensor. An automatic high-frequency heating device configured to heat an object to be heated until the value reaches a second threshold value that is larger than the first threshold value.