JPH0355437A - Cooking oven - Google Patents

Abstract

PURPOSE:To detect the completion of heating regardless of water content and color of food by a method wherein the temperature drop in a compartment due to the latent heat of vaporization is detected by a heating completion detector, and a controller stops power supply to heaters on receipt of the heating completion information. CONSTITUTION:When food A is heated and its temperature reaches 100 deg.C, the heat rays from infrared ray heaters 3 and 4 are absorbed by steam and carbon dioxide gas, etc. generated from the food A resulting in a temporary decrease in the temperature in the compartment. The temperature drop in the compartment due to the latent heat of steam is detected by a compartment temperature sensor 7, and the temperature data is supplied to a detection circuit 14. The detection circuit 14 compares the present temperature with the temperature detected by the compartment temperature sensor 7, decides that cooking of food A completes when the detected temperature becomes lower than a given value, and supplies this signal to a control circuit 15. On receipt of the decision signal, the control circuit 15 turns a drive circuit 17 off. As a result, power supply to the infrared lay heaters 3 and 4, a magnetron 8 and an exhaust fan 11 is stopped.

Description

[Detailed Description of the Invention] <Field of Application of Industrial Articles> The present invention relates to a heating cooking device such as an oven range, and more specifically to a heating device that detects a decrease in internal temperature due to latent heat of vaporization to indicate the end of cooking food. t. The present invention relates to a novel heating cooking device that makes it possible to control heat and heat.

Prior Art and Problems to be Solved by the Invention A conventional heating cooking device has a heating means such as an electric heater or a magnetron, and a temperature sensor arranged in a heating chamber, and adjusts the internal temperature detected by the temperature sensor. Based on this, the power supplied to the heating means is controlled by a control circuit.

When cooking ingredients using such a heating cooking device, the heating temperature and heating time are adjusted in advance according to the type and weight of the ingredients to set the optimal conditions for cooking the quality ingredients. Afterwards, the heating means is driven.

Then, the food is heated at the heating temperature set as described above, and when the preset heating time comes, the cooking is finished.

By adjusting the heating time and heating temperature in this way, it is possible to prevent overcooking or undercooking of quality ingredients, resulting in delicious dishes.

However, even if the ingredients are of the same type and weight, if the degree of dryness, surface color, or shape of the ingredients is different depending on the freshness of the ingredients, the degree of grilling will differ and the best result may not be achieved. .

In addition, there have been cases where the food has been damaged due to overcooking.

In order to avoid the above-mentioned inconvenience, sensors for detecting the degree of baking, such as a water vapor sensor and a gas sensor, are placed inside the heating chamber to detect water vapor generated from the food during cooking, or detect carbon dioxide gas to determine when the food is baked. That is, a means is taken to determine the end of heating cooking.

However, it is generally difficult to determine whether food has been cooked, and there is a problem in that the accuracy of detecting water vapor or gas decreases due to fogging or staining of the sensor section due to various types of moisture generated by the food. In addition, there is a problem in that the cost of the sensor itself is increased by attaching such a sensor, which increases the cost.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a heating cooking device that can determine whether the food has been cooked regardless of the degree of dryness of the food, the color of the surface, etc.

Means for Solving the Problems> The heating cooking device of the present invention for achieving the above object is equipped with a heating means in a heating chamber for storing food and a temperature sensor for detecting the temperature inside the vehicle. The temperature inside the car after reaching the saturation temperature detected by the temperature sensor is compared with the threshold temperature set based on the temperature drop due to the latent heat of vaporization, and the temperature inside the car is detected to fall below the threshold temperature. It is characterized by comprising a doneness detection means and a control means for stopping power supply to the heating means in accordance with detection information from the doneness detection means.

Function> In the present invention having the above configuration, when the food is heated to 100° C., water vapor, carbon dioxide, etc. are released from inside the food, and the latent heat inside the refrigerator is taken away by the water vapor, carbon dioxide, etc. As a result, the internal temperature detected by the temperature sensor temporarily decreases. This phenomenon is generally referred to as latent heat of vaporization. The point at which this latent heat of vaporization appears is the basis for determining the timing of baking the food.

Then, the baked-in detection means compares the temperature inside the refrigerator after reaching the saturation temperature with a threshold temperature determined based on the decrease in the temperature inside the refrigerator due to the latent heat of evaporation, and determines that the temperature inside the refrigerator is lower than the threshold temperature. By detecting a decrease in the temperature, it is possible to detect when the food is baked. When the control means is supplied with the detection information from the baking-done detection means, it assumes that the cooking has been completed and stops supplying power to the heating means.

The latent heat of vaporization will be explained based on the graph shown in FIG. 4, which shows changes in the temperature inside the refrigerator. In addition, 340 g of bread dough was used as the ingredient, a temperature sensor was inserted inside the dough, the cooking time To was set to 28 minutes, and the internal temperature VO was set to 120°C.
It is set to . This graph shows that the internal temperature reaches the set temperature about 14 minutes after heating starts (at this time, the temperature of the bun is about 100%).
℃), the temperature decrease due to the latent heat of vaporization occurs approximately 21 minutes after the start of heating, and the temperature at this time decreases to 50 to 60°C. This point can be determined to be the end of heating cooking. Therefore, compared to the set heating time of 28 minutes, the heating operation is completed in 21 minutes, reducing the time by about 7 minutes and saving the amount of power.

Embodiments Hereinafter, the heating cooking apparatus of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of the heating cooking device according to the present invention, and FIG. 2 is a perspective view showing the external appearance of the heating cooking device main body.

Reference numeral 1 denotes a heating cooking device main body, and a heating cooking chamber 2 is provided in this main body 1. Far-infrared heaters 3 and 4 are arranged in the upper and lower parts of the heating cooking chamber 2, and both far-infrared heaters 3 and 4
A saucer 5 for placing food A is provided between them. An internal temperature sensor 7 (such as a thermistor) is attached to the side wall 6 of the heating cooking chamber 2 to detect the internal temperature.

Further, the main body 1 is provided with a magnetron 8 as a heating source, a heater 10 for preheating the oxidation catalyst layer 9 that absorbs odors generated from food, an exhaust fan 11, and the like. In addition, 12
, 13 are heater temperature sensors that detect the temperatures of the far-infrared heaters 3 and 4.

The far-infrared heaters 3 and 4 emit electromagnetic waves with a wavelength of 2 to 1000 μm, and far-infrared rays have the property of being absorbed by carbon dioxide gas and water vapor generated from the food material A heated to 100°C. Therefore, when the food material A reaches 100° C., a large amount of carbon dioxide gas and water vapor are released, and the temperature in the cooking chamber 2 temporarily decreases due to the phenomenon of latent heat of vaporization. This phenomenon of latent heat of vaporization is particularly noticeable in carbohydrates such as potatoes and bread dough, and when these types of foods are used as food A, the internal temperature drops to about 50 to 60 degrees Celsius (Figure 4). reference).

Next, the structure of the electric circuit will be explained. The vehicle interior temperature sensor 7 and heater temperature sensors 12 and 13 are connected to a detection circuit 14, and the detection circuit 14 detects a temperature drop in the cooking chamber 2 due to latent heat of steam based on temperature data from the interior temperature sensor 7. This detection signal is then supplied to the control circuit 15.

An operation panel 16 attached to the surface of the main body 1 is connected to the control circuit 15, and a far-infrared heater 3,
4. Magnetron 8, heater 10 for preheating the oxidation catalyst layer 9
, a drive circuit 17 for driving the exhaust fan 11 is connected thereto. Note that the detection circuit 14 and control circuit 15 are blocks that represent the functions of a microcomputer.

The operation of the cooking device having the above structure is as follows. The cook places the food A on the saucer 5 in the cooking chamber 2, operates the timer knob 18 and temperature setting knob 19 on the operation panel 16 to set the cooking temperature and cooking time, and then
Start the cooking device.

Then, the control circuit 15 turns on the drive circuit 17, and power is supplied from the drive circuit 17 to the far-infrared heaters 3 and 4, the magnetron 8, the preheating heater 10, and the exhaust fan 11.

Food material A is heated by far infrared heaters 3 and 4 and magnetron 8.
When the temperature of food material A reaches 100° C., water vapor and carbon dioxide gas generated from food material A increase. According to spectral analysis, water has far infrared radiation of 3 μm, 6 μm, and 15 μm.
It has an absorption peak in μm, and carbon dioxide gas also has an absorption peak in the same vicinity. Therefore, the far infrared heater 3,
The heat rays from 4 are absorbed by water vapor, carbon dioxide, etc., and the temperature inside the refrigerator temporarily drops.

The internal temperature sensor 7 detects the temperature drop in the heating cooking chamber 2 due to the latent heat of steam, and this temperature data is sent to the detection circuit 14.
supplied to

The detection circuit 14 compares a preset temperature with the temperature detected by the internal temperature sensor 7, and compares the temperature detected by the internal temperature sensor 7.
When the detected temperature becomes equal to or lower than a predetermined value, it is determined that cooking of the food material A has been completed, and this determination signal is supplied to the control circuit 15.

Upon receiving the determination signal, the control circuit 15 turns off the drive circuit 17.
do. Therefore, power supply to the far-infrared heaters 3 and 4, magnetron 8, and exhaust fan 11 is stopped.

FIG. 3 is a diagram showing a flowchart of the detection circuit 14 and control circuit 15.

In step 1, the internal temperature V is set to vO and the cooking time T is set to TO. That is, the heating conditions for food material A are set.

In step 2, a heating operation is activated.

In step 3, the vehicle interior temperature V after the start of heating is read.

In step 4, heating is performed until the internal temperature V reaches the set value VQ, and when the internal temperature ■ reaches the set value VO, the internal temperature V is maintained at the set value Vo.

In step 5, after the vehicle interior temperature V reaches the set value VQ, it is determined whether the temperature V has decreased by ΔV from the set value vo based on the latent heat of vaporization. That is, V-VQ and ΔV are compared. If the comparison result is v-vo aΔV, it is determined that the heating has ended, and in step 7, the drive circuit 17 is turned OFF to end the heating operation.

In step 5 above, if the comparison result is V - VQ - ΔV, in step 6 it is determined whether the heating cooking time T has reached the initial setting time TO, and if T<To, the process in step 5 above is performed. repeat. On the contrary, T yo TO
If. In step 7, the heating operation is completed.

With step 6 above, even if the amount of food is small or the initial moisture content of the food is low, overcooking can be avoided by using two methods: initial setting of cooking time and detection of temperature drop due to latent heat of evaporation. It is possible to prevent loss of good quality materials.

Note that the temperature change ΔV due to the latent heat of vaporization is set to 25 to 50% of the set value vO. It is also possible to set the amount of change in this ΔV depending on the type of food to be cooked.

According to the heating cooking apparatus of the above embodiment, when the internal temperature of the food reaches 100"C, that is, when cooking and heating are finished, when the food is vegetables such as potatoes, or carbohydrates such as bun dough, At the desired point, a large amount of water vapor and carbon dioxide gas is released.The carbon dioxide gas released into the refrigerator has infrared activity and absorbs the radiant heat of the heat rays (electromagnetic waves with a wavelength of 2 to 1000 μm) from the far-infrared heater. In addition, water vapor temporarily lowers the temperature inside the refrigerator as latent heat of evaporation.Therefore, when cooking the above-mentioned foodstuffs, a temporary decrease in temperature of This becomes a signal indicating that the temperature has reached 1oO''C, and by detecting this, an accurate timing for finishing cooking can be obtained.

In addition, since the internal temperature sensor 7 is used as a sensor for detecting the end of heating and a sensor for detecting the temperature inside the refrigerator, it can be used as a sensor for detecting the temperature inside the refrigerator and the end of heating. 2F! Since there is no need to provide similar sensors, costs can be reduced accordingly.

Effects of the Invention> According to the present invention, the temperature within the refrigerator decreases due to the latent heat of evaporation, which is detected by the doneness detection means, and when the control means is supplied with the doneness detection information, the control means determines when the cooking is finished. Since the power supply to the heating means is stopped, the end of heating can be detected regardless of the moisture content or color of the food. Therefore, it is possible to obtain an accurate cooking end timing, and to prevent food loss due to overcooking. In addition, since the temperature sensor is used as a sensor to detect the end of heating and a sensor to detect the temperature inside the refrigerator, two sensors are used to detect the temperature inside the refrigerator and the end of heating.
Since there is no need to provide different types of sensors, costs can be reduced accordingly.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the heating cooking device according to the present invention, FIG. 2 is a perspective view of the heating cooking device main body of FIG. 1, FIG. 3 is a flowchart of the detection circuit and the control circuit, and FIG. The figure is a graph showing how the temperature inside the refrigerator changes. 1: 3, 8: Cooking device main body, 2: Cooking chamber, 4: Far-infrared heater, 7: Internal temperature sensor, magnetron, 14: Detection circuit, 2nd control circuit, 16: Operation panel, : Drive circuit No. figure

Claims (1)

[Claims] 1. Heating means in the heating chamber that houses the food; Equipped with a temperature sensor that detects the temperature inside the refrigerator. In the heated cooking device, Saturation detected by the above temperature sensor The internal temperature after reaching the temperature and the latent heat of vaporization Threshold set based on temperature drop due to The temperature inside the refrigerator is compared to the threshold temperature. A baking test that detects when the temperature decreases. knowledge means and Detection information from this baking detection means In response to the notification, power supply to the above heating means was stopped. characterized by having a control means to Heating cooking device.