KR100575659B1 - Cooking sensor for microwave oven - Google Patents

Abstract

The present invention relates to a cooking sensor of a microwave oven, by using an expensive humidity sensor, a gas sensor, a temperature sensor, etc. as the cooking sensor in detecting water vapor generated when food is cooked using a conventional cooking sensor. There was a problem that the unit price increased. Therefore, the present invention was devised to solve the above-mentioned conventional problems, and by detecting the change in the amount of water vapor generated as the food is cooked by using two or more strands of insulated sheathed enameled wire, The use of wire reduces the overall manufacturing cost and prevents corrosion by water vapor.

Description

Cooking sensor of microwave oven {COOKING SENSOR FOR MICROWAVE OVEN}

1 is a cross-sectional view showing the configuration of a microwave oven using a conventional gas sensor.

Figure 2 is a relationship showing the generation of water vapor / gas amount over time in heating the food in Figure 1;

Figure 3 is a perspective view showing the configuration of a microwave oven to which the present invention is applied.

Figure 4 is a block diagram showing the configuration of the cooking sensor in FIG.

FIG. 5 is a relationship diagram showing a change in capacitor capacity of an enameled wire with time in heating food in FIG. 3.

6 is a simulation diagram showing the change in capacitor capacity of the enameled wire with time in heating 500 cc of water in FIG.

*** Description of the symbols for the main parts of the drawings ***

10: cooking chamber 20: exhaust window

30: cooking sensor 31: enameled wire

32: LC resonance unit 33: frequency change measurement unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooking sensor of a microwave oven, and more particularly, to a cooking sensor of a microwave oven which detects water vapor generated when food is cooked using an insulated coated wire in automatically cooking food in a microwave oven.

1 is a cross-sectional view showing the configuration of a microwave oven using a conventional gas sensor, as shown therein, after placing the food (2) in the center of the interior, using a microwave (Microwave) to heat the cooking chamber (1) and ; An exhaust window 3 disposed at an upper left side of the cooking chamber 1 to discharge steam or gas generated when the food 2 is cooked to the outside; It consists of a cooking sensor 4 for detecting the amount of steam or gas discharged through the exhaust window 3, it will be described in detail with reference to Figure 2 attached to the operation process according to the prior art configured as described above.

First, the conventional cooking sensor 4 uses a humidity sensor, a gas sensor, a temperature sensor, or the like, which detects water vapor or gas generated as the food 2 is heated.

Here, after placing the food 2 in the center of the cooking chamber 1, the food 2 is heated by using a magnettron (not shown).

Therefore, when steam or gas is generated as the food 2 in the cooking chamber 1 is heated, the cooking sensor 4 detects the amount of the steam or gas exhausted through the exhaust window 3.

That is, as shown in FIG. 2, the cooking sensor 3 detects the amount of water vapor or gas generated over time, and it can be seen that the amount of water vapor or gas is rapidly increased at the boiling point of the food 2. have.

Accordingly, the cooking time 3 is detected by the following equation 1 by detecting the time Tb to the boiling point at which the steam or gas amount increases by more than the reference value Δh through the cooking sensor 3. The automatic cooking of the food 2 is performed by using the cooking time Tt.

Tt = Tb + kTb

Here, k is a constant that varies depending on the type of food and the intended use.

As described above, by using an expensive humidity sensor, a gas sensor, and a temperature sensor as the cooking sensor in detecting water vapor generated as the food is cooked using the conventional cooking sensor, there is a problem in that the manufacturing cost increases.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and the change in the amount of water vapor by using the change in the capacitor value of two or more strands of insulated sheathed wires by steam generated as the food is cooked. It is an object of the present invention to provide a cooking sensor of a microwave oven for sensing.

The configuration of the present invention for achieving the above object comprises two or more strands of insulated sheathed wire in which the capacitor value is changed by the amount of steam generated as the food is cooked; An LC resonator in which a resonant frequency is changed by a change in a capacitor value of the insulated sheath wire; Characterized in that it consists of a frequency change measuring unit for measuring the resonance frequency of the resonator of the LC.

Hereinafter, with reference to the accompanying drawings, the operation and effect of an embodiment of the present invention will be described in detail.

3 is a perspective view showing the configuration of a microwave oven to which the present invention is applied, and as shown therein, after placing food (not shown) in the center of the inside, a cooking chamber 10 for heating it using microwaves and ; An exhaust window 20 disposed at an upper left side of the cooking chamber 10 to discharge steam or gas generated when the food is cooked to the outside; It consists of a cooking sensor 30 for sensing the amount of steam or gas discharged through the exhaust window 20.

And, as shown in Figure 4, the cooking sensor 30 includes an enamel wire 31, which is an insulated wire of braided shape having two or more strands in which the capacitor value is changed by the amount of steam generated as the food is cooked; An LC resonator 32 in which a resonant frequency is changed by a change in a capacitor value of the enamel wire 31; It consists of a frequency change measuring unit 33 for measuring the resonant frequency of the resonator 32 of the LC, it will be described in detail with reference to Figs.

First, the enamel wire 31, which is an insulation coated conductive wire having two or more strands in the cooking sensor 30, operates in the same manner as the structure in which the insulator is inserted between the two conductors to have a constant capacitor value.

Here, in the detection of the capacitor value, when the resonant frequency is output from the resonator 32 in accordance with the capacitor value of the enamel wire 31, the resonant frequency of the resonator 32 in the frequency change measuring unit 33 is measured. Reads the capacitor value of the enamel wire (31).

Then, after placing the food in the center of the cooking chamber 10, as the food is heated by the microwave generated from the magnetron, water vapor or gas is generated, so that the cooking sensor 30 through the exhaust window 20 The amount of water vapor or gas discharged to the outside is detected through a capacitor value of the enamel wire 31.

Then, as time passes, the amount of water vapor or gas generated from the food in the cooking chamber 10 rapidly increases at a boiling point, as shown in FIG. 2, so that the amount of vapor deposited on the enamel wire 31 increases. Thus, the capacitor value of the enamel wire 31 rises rapidly at the boiling point as shown in FIG. 5.

That is, as shown in FIG. 5, since the capacitor value of the enamel wire 31 is rapidly increased at the boiling point Tb of the food, through the resonator 32 and the frequency change measuring unit 33. The food is automatically cooked using Equation 1 by detecting the time Tb until the boiling point at which the capacitor value of the enamel line 31 rapidly increases above the reference value Δh.

In the case of heating 500 cc of water in a beaker in the cooking chamber 10, the capacitor value of the enameled wire 31 which varies according to the amount of water vapor emitted to the outside through the exhaust window 20 when the first water is heated is shown in FIG. It is the same as graph (a) of 6.

Therefore, the capacitor value of the enamel wire 31, which was kept constant, may be rapidly changed to obtain the time Tb until the boiling point.

In addition, the capacitor value of the enameled wire 31 that varies with time as the 500cc of water is repeatedly heated, is constant as shown in the graphs (b), (c), and (d) of FIG. 6. It is maintained and rises sharply at boiling point.

Here, the heating time Tb to the boiling point of water in which the capacitor value of the enamel wire 31 changes rapidly is constant about 240 seconds.

As described in detail above, the present invention detects the change in the amount of water vapor generated when food is cooked by using enamel wire, which is two or more strands of insulated coated wire, so as to reduce the overall manufacturing cost by using inexpensive enamel wire. In addition to reducing, it is effective in preventing corrosion by water vapor.

Claims (1)

Two or more strands of insulated sheathed wire in which the capacitor value is changed by the amount of steam generated as the food is cooked; An LC resonator in which a resonant frequency is changed by a change in a capacitor value of the insulated sheath wire; The cooking sensor of the microwave oven, characterized by comprising a frequency change measuring unit for measuring the resonance frequency of the resonator of the LC.

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