JPH04139314A - Cooking oven - Google Patents

Abstract

PURPOSE:To prevent uneven heating and send hot-air suitable for cooking to food by a method wherein the rotating speed, rotating direction and output time period of a circulation fan are united into a data, and data series each containing a cycle of combination of a large number of the data are prepared so that the power spectra of flow rates of a circulation fan are in inverse proportion to the frequencies. CONSTITUTION:A heater chamber 27 is located inside a heating compartment 19 where food 20 to be cooked is placed, and provided with an annular heater 14 and a circulation fan 13. A photo-coupler 40 is controlled by outputs of a microcomputer 1 so as to vary the rotating speed of the circulating fan 13. The rotating speed, rotating direction and output time period of the circulating fan 13 are united into a data, and data series each containing a cycle consisting of combination of a large number of the data are stored in the microcomputer 1. With this data series in use, controls take place according to the data series by which the power spectra of the flow rates of a circulation fan 13 are in inverse proportion to the frequencies, so that food is scorched on the surface before water contained in the food oozes out and evaporates. As a result, water is retained inside the food and a spongy, soft meet can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heating cooking device such as a microwave oven, and particularly aims to improve the finish of cooked food.

2. Description of the Related Art Conventionally, some heating cooking apparatuses such as microwave ovens are equipped with an electric oven function. When used as an electric oven, hot air is forcibly circulated by a circulation fan to heat the food placed on the shelf. However, depending on where the food is placed on the shelf, the degree to which the hot air hits the food differs, resulting in uneven heating.

One possible means to prevent such uneven heating is to provide a baffle plate that acts as a wind resistor, but the required dimensional accuracy of the gap between the baffle plate and the circulation fan may vary due to component manufacturing. , and therefore mass production was impossible.

In addition, with conventional control methods, it is important to check whether the circulation fan is rotating or not.
It was not possible to precisely control the hot air by controlling whether it was rotating or not.

Problems to be Solved by the Invention As described above, in the conventional heating cooking apparatus, it is difficult to adopt a structure that can be mass-produced and that can prevent uneven heating.

Additionally, when cooking over open fires or charcoal, the hot air fluctuates over time, requiring constant and delicate control of the heat. In other words, heating with this fluctuation is a heating method that is originally suitable for cooking.

The present invention has been made in view of the above, and its purpose is to:
To provide a heating cooking device that can prevent uneven heating, can be mass-produced, and can provide hot air suitable for cooking to food.

Means for Solving the Problems To achieve the above object, the present invention provides a heating chamber for storing food to be cooked, a heating energy generating means provided in the heating chamber, and a forced air flow in the heating chamber. It consists of a circulation fan that generates the heating energy and a control means that controls the heating energy generation means and the circulation fan, and the rotation speed and rotational direction output time of the circulation fan are regarded as one data, and a large number of combinations of the above data are divided into one period. As the data series, a plurality of one-cycle data series are stored, and the above 1
The heating energy of the heating energy generating means is controlled by a periodic data series, and the one-cycle data series is characterized in that the power spectrum of the air volume of the circulation fan is inversely proportional to the frequency.

Function: In the heating cooking device of the present invention, the rotation speed of the circulation fan increases or decreases, and by rotating forward or reverse, the temperature of the air in the heating chamber is changed to a mixture of high temperature and low temperature areas. There is no unevenness in heating distribution. This corrects uneven heating of the food. In addition, the hot air pattern is not fixed, but fluctuates over time, and the firepower is constantly and delicately controlled.
The cooking results will be better.

EXAMPLE Hereinafter, a heating cooking apparatus according to an example of the present invention will be explained based on the drawings. A heating cooking device according to an embodiment of the present invention is constructed by adding an electric oven function to a microwave oven.

The commercial power supply II '112 supplies a voltage generated by a constant voltage generation circuit 5 to a microcomputer (hereinafter referred to as microcomputer) 1 via a low voltage transformer 3.

Connected to the terminals of the microcomputer 1 are a thermistor 12 as a temperature detector whose analog value changes depending on the temperature, and a timer knob 7 for setting numerical values such as heating time.

Further, a display device 6 for displaying cooking functions, cooking menus, cooking time, and cooking temperature is connected to the terminals of the microcomputer 1.

In addition, the terminals of the microcomputer 1 include a menu switch group 8-e for selecting the necessary heating function and cooking menu, a raising switch 8-c for setting the heating target temperature, a lowering switch 8-d, and a cooking switch group 8-e. Input means 8 is connected, which includes a start switch 8-a for instructing to start cooking, a cancel switch 8-b for instructing to interrupt or cancel cooking, and the like.

On the other hand, R(')M of microcomputer I manually inputs the heating function, cooking menu, heating target temperature, heating time, etc., and displays it on the display bag W6 and stores it in the RAM of microcomputer 1. Set up.

Further, the ROM of the microcomputer 1 counts the time signal taken in via the time pulse generation circuit 4 to measure the heating time.

Furthermore, when the start switch 8-a is input after completing the predetermined heating settings, the ROM of the microcomputer 1 is activated.
Based on the contents stored in the AM, the magnetron 10 or the heater 14 is operated to start heating, and further, the magnetron 10. The heater 14 is controlled.

Further, after the start of heating, the ROM of the microcomputer 1 displays on the display device 6 the heating status in progress, for example, the set heating time, which is subtracted as time passes.

Figure 2 shows the control circuit for the rotation speed, forward rotation, and reverse rotation of the circulation fan.The photocoupler 40 is controlled by the output of the microcomputer B.
By doing so, it is possible to control the trifle 15 of the primary circuit and vary the rotation speed of the circulation fan 13 provided with the circulation fan motor 37. Further, forward rotation or reverse rotation of the circulation fan I3 is determined by turning on or off the relay contact 16. That is, the rotation speed of the circulation fan 13 can be controlled by the on-time of the photocoupler 40.

FIG. 3 is a longitudinal cross-sectional view showing the mechanical configuration of a part of the cooking device. In the same figure, by opening and closing the door 8, food items 2020, . . . to be cooked are taken in and out of the heating chamber 19. The heating chamber 19 is an oven upper plate 2L.
It is composed of an oven bottom plate 22, a pair of oven side plates 23 (the one on the near side is not shown in the drawing), and a casing 24. The heating chamber 19 is divided into an oven chamber 26 at the front and a heater chamber 27 at the rear by an oven rear plate 25 provided at the rear.

The rear plate 25 has a suction port 28 formed by a large number of small holes in the center portion, and an upper air outlet 29 and a lower air outlet 30 formed by a large number of small holes at both upper and lower end portions. . On the inner side of the oven chamber portion of the oven side plate 23, shelf supports (not shown) are formed in two levels, upper and lower, by drawing. Due to their seed coat, the food to be cooked 20.
20. An upper shelf board 31 and a lower shelf board 32 on which ... are placed are supported.

An annular heater 14 and a circulation fan 13 are provided in the heater chamber 27 described above. Further to the rear of the casing 24 located at the rear of the heater chamber 27, a casing cover 35 is provided with a heat insulating material 34 in between, and these members prevent heat leakage to the rear.

The heat insulator 34 may be omitted in some cases. A motor mounting plate 36 is attached on the casing cover 35, and the mounting plate 36
A circulation fan motor 3 that drives a circulation fan I3 by
7 is supported. A self-cooling fan 39 is attached to the motor shaft 38 of the circulation fan motor 37 at a position outside the casing cover 35 .

When the above-mentioned heater 14 and circulation fan 13 are operated simultaneously, the air heated by the heater 14 in the heater chamber 27 is forcibly circulated as hot air, as shown by arrows in the figure.

In addition, the ROM of the microcomputer 1 stores the rotation speed, rotation direction, and output time of the circulation fan 13 as one data corresponding to each cooking, and stores many combinations of the above data as one cycle data series. , an example is shown in FIG.

The ROM of the microcomputer 1 stores a plurality of one-cycle data series as shown in FIG. 4, corresponding to each cooking. When hot air with fluctuations as shown in Figure 4 is applied to food, the surface is scorched before the moisture seeps out, preventing evaporation, retaining the moisture inside, and making the meat fluffy and tender. Favorable cooking experiment results were obtained.

In addition, in one cycle of data series, the power spectrum of the air volume of the circulation fan is inversely proportional to the frequency CA/f: f
= frequency), it was clearly observed that the surface burns before the moisture seeps out, preventing evaporation, retaining the moisture inside, and making the meat fluffy and soft. .

That is, 1/f control seems to be particularly desirable as hot air control for cooking food. The frequency characteristics of the power spectrum of the air volume of the circulation fan at that time are shown in FIG.

Furthermore, the power spectrum of air volume is l/f"17f'-'
etc. (f=frequency), and to add more of these, it is only necessary to add corresponding data for each.

In the above example, the air volume of the circulation fan of the microwave oven is set to high or low.
We have explained how to switch to stages, but you can also increase the number of individual stages, combine forward rotation and reverse rotation,
It goes without saying that it can also be easily applied to other physical quantities.

Effects of the Invention As described above, according to the heating cooking device of the present invention, (11
Uneven heating of cooked food can be prevented.

(2) Mechanical structures can be mass-produced without major restrictions.

(3) The pattern of hot air is not fixed and fluctuates over time, resulting in better cooking results.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a control circuit of a heating cooking device according to an embodiment of the present invention, Fig. 2 is a control circuit diagram of the circulation fan motor, and Fig. 3 is a longitudinal sectional view showing the mechanical configuration of the same part. , a timing chart of the rotation speed control of the fourth circulation fan, and FIG. 5 is a frequency characteristic diagram of the air volume of the fourth circulation fan. 1...Microcomputer, 11...
- Rotation speed control circuit, 13...Circulation fan. Name of agent: Patent attorney Shiyori Akira Okaji, 2nd figure law source

Claims (2)

[Claims] (1) A heating chamber for storing food to be cooked, a heating energy generating means provided in the heating chamber, a circulation fan for forcibly generating an air flow in the heating chamber, and a heating energy generating means and circulation fan provided in the heating chamber. The control means controls the rotation speed, rotation direction, and output time of the circulation fan as one data, and sets a large number of combinations of the above data as one cycle data series, and generates a plurality of one cycle data. A heating cooking apparatus characterized in that a series is stored, and the heating energy of the heating energy generating means is controlled by the data series of one cycle. (2) The heating cooking apparatus according to claim 1, wherein the data series of one cycle is a data series in which the power spectrum of the air volume of the circulation fan is inversely proportional to the frequency.