JPS6334370B2 - - Google Patents

Description

Detailed Description of the Invention - Industrial Application Field This invention relates to an electric oven used to heat and bake food, and in particular an electric oven equipped with both a near-infrared heater and a far-infrared heater as heaters. It's about ovens.

●Conventional technology Electric ovens are equipped with a heater that emits infrared rays (heat rays). There are various types of heaters that emit infrared rays in different frequency bands.Those that emit near infrared rays are suitable for heating the surface of an object, and those that emit far infrared rays are suitable for heating the inside of an object. Are suitable. Taking advantage of this,
Utility Model Application Publication No. 1987-87011 discloses a device in which far-infrared heaters and near-infrared heaters are arranged alternately to brown the surface of yakitori or grilled fish while also frying the inside in a short time. has been done.

●Problems to be solved by the invention In such a device equipped with both a far-infrared heater and a near-infrared heater, the surface of the food is fried by the uniform infrared heater, and the inside of the food is fried by the far-infrared heater. Therefore, when baking thinly sliced toast, sweet bread, etc., irradiate a relatively large amount of near-infrared rays, and when baking potatoes, sweet potatoes, thick-sliced toast, etc., irradiate a relatively large amount of far-infrared rays to make these foods delicious. It is necessary for

Food also contains sugars, polyhydric alcohols, esters, carboxylic acids, amino acids, and other molecules, and when food is heated, these food molecules are broken down and synthesized to form other molecules at high temperatures. This is a factor that determines the taste and flavor of baked foods. Each of these food molecules has its own infrared absorption spectrum. For example, in alcohol,
There is a peak in the infrared absorption spectrum around the wave number 1100/cm, and for carboxylic acids, the wave number is 1700/cm.
There are peaks in the infrared absorption spectrum before and after. This means that when food is heated with a heater, the degree of heating of each of the molecules that make up the food differs depending on the frequency band of the infrared rays emitted from the heater. ,
For example, kabayaki grilled over charcoal is delicious, but kabayaki grilled over gas is not. This is because the degree of heating of each molecule that makes up kabayaki is different between gas and charcoal fires, so the taste of kabayaki grilled over charcoal is different. will be different.

Therefore, it is extremely important to grill various foods deliciously by varying the irradiation ratio of far-infrared rays and near-infrared rays depending on the ingredients contained in the food to be grilled.

However, conventional electric ovens equipped with far-infrared heaters and near-infrared heaters do not have a structure to adjust the irradiation ratio of near-infrared rays and far-infrared rays depending on the type of food to be baked. However, the operation was extremely complicated and required skill. This invention solves this problem and
This was developed with the aim of providing an easy-to-operate electric oven that can bake various foods under optimal conditions depending on their physical and chemical properties.

●Structure of the invention This invention installs two types of heaters with different irradiation frequency bands in an electric oven, namely a near-infrared heater and a far-infrared heater, and controls the amount of current applied to both heaters in inverse proportion by a current control circuit. It was designed to do so.

●Effect The above configuration makes it possible to change the irradiation spectrum distribution without changing the amount of infrared rays irradiated to the food heated in the electric oven, depending on the physical dimensions of the food being heated, the infrared transmittance, etc. Furthermore, it is possible to adjust the spectral distribution of the irradiated infrared rays according to the infrared absorption spectral distribution of the molecules that determine the taste and flavor of the food. You will be able to bake the most delicious food.

According to the structure of the present invention, by changing the amount of current applied to the far-infrared heater and the near-infrared heater in inverse proportion, the quality of heat, that is, the spectral distribution of heat rays can be adjusted without changing the total amount of heat radiated from both heaters. Since it can be changed, it is extremely easy to make adjustments according to the properties of the food to be baked.

●Example of the invention The figures show an example in which the present invention is applied to a household electric oven. FIG. 3 is a perspective view showing the arrangement of the heater.

In the figure, 1 is the oven housing, 2 is the door, and 3
is a food stand, 4a, 4b are upper heaters, 5a, 5b
1 is a lower heater, 6 is a temperature detection sensor such as a thermistor, 7 is a power source, 8 is a power switch, 9 is a temperature adjustment contact that is turned on and off according to the output signal of the temperature detection sensor 6, 10a and 10b are current control circuits, 11
is a variable resistance.

The heaters 4a and 5a are, for example, bare nichrome wire heaters for near-infrared irradiation, and the heaters 4b and 5b are ceramic heaters for far-infrared irradiation, for example, in which a nichrome wire is surrounded by zircon ceramic. A current control circuit 10a is connected in series to the near-infrared heaters 4a and 5a connected in parallel, and a current control circuit 10b is connected in series to the far-infrared heaters 4b and 5b connected in parallel. Current control circuit 10
Reference numerals a and 10b are well-known circuits that control the phase of the triacs 12a and 12b using diaxes 13a and 13b, and the operation of the triacs 12a and 12b is started by changing the resistors 11a and 11b connected to the diacs 13a and 13b. It controls the point. In an actual circuit, various additional circuits are provided in order to prevent hysteresis and stabilize operation, but since these are well-known circuits, they are omitted in the drawings. Resistors 11a and 11b are the resistances of two variable resistors 11, and their connection point 1
By reversing 4a and 14b, if one resistor 11a is made larger, the other resistor 11b is made smaller in conjunction with this, and the triax 12
The current values controlled by a and 12b are made to change inversely proportionally. That is, the near-infrared heater 4
When the calorific value of far-infrared heaters 4b and 5b is decreased or increased, the calorific value of far-infrared heaters 4b and 5b is increased or decreased, so that the total calorific value does not change.

●Effect of the invention According to the above configuration, by adjusting the variable resistor 11, it is possible to change the spectral distribution of infrared rays irradiated to food in the electric oven. The physics of the food being grilled can be adjusted by increasing the heat output of the heaters 4b and 5b so that it is baked from the inside, and for thinly sliced toast by increasing the heat output of the near-infrared heaters 4a and 5a so that the surface is baked. By irradiating infrared rays with the optimal frequency distribution according to the target and chemical properties, all types of food can be grilled deliciously, and the food can be grilled to suit your taste, such as the taste of charcoal, gas fire, and stone oven. It is possible to obtain an electric oven that can be used to bake to a desired taste, and the adjustment operation is simple and does not require skill.

[Brief explanation of the drawing]

The figures show an embodiment in which the present invention is applied to a household electric oven. Fig. 1 is a perspective view schematically showing the overall configuration, Fig. 2 is a perspective view showing the external appearance of the oven, and Fig. 3 is a perspective view schematically showing the overall configuration. The figure is a perspective view showing the arrangement of the heaters. In the figure, 3 is a food table, 4a, 5a are near-infrared heaters, 4b, 5b are far-infrared heaters, 6 is a temperature detection sensor, 9 is a temperature adjustment contact, 10a, 10b is a current control circuit, 11 is a variable resistor, 12a, 12
b is a triax, and 13a and 13b are diaxes.

Claims (1)

[Claims] 1 A near-infrared heater and a far-infrared heater are provided as heat sources, and a current control circuit is connected in series to each of the near-infrared heater and far-infrared heater, and the current value given to both heaters is controlled in inverse proportion. An electric oven characterized by: