JP2013079745A - Refrigerator freezer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that, with a microwave processing device mounted in a refrigerator freezer, the quality is likely to deteriorate because a subject to be heated is irradiated with microwaves, and a processing time also gets longer.SOLUTION: Prior to processing the subject, microwaves of a chirp signal are emitted so that a process frequency is determined based on a frequency at which reflected power becomes minimal or least. The generation of microwaves of the process frequency during the processing of the subject reduces the amount of reflected power to be generated, thereby preventing a microwave generator from being damaged or failed.

Description

  The present invention relates to a refrigerator-freezer that processes an object with microwaves.

  Conventionally, in the refrigerator-freezer of patent document 1, it has a function which generates a microwave using a magnetron, thaws food using the energy of microwave, and stirs an electric wave and air using a rotary blade. In some cases, uneven thawing and temperature are made constant.

JP-A-3-31992

  However, when a magnetron is used for a refrigerator-freezer, it is necessary to take a large installation space, and the capacity of the refrigerator is greatly reduced, so that commercialization is difficult.

  Further, it is conceivable to use a semiconductor instead of a magnetron as a means for reducing the installation space. As a heating method using a semiconductor, Japanese Patent Laid-Open No. 56-96486 has been proposed. However, when a very large reflected power is generated when the microwave frequency is swept, the heat generated by the reflected power is generated. May exceed the heat dissipating ability of the heat dissipating member, and the semiconductor element may be damaged. In addition, when the microwave frequency is swept, the object to be heated such as food is irradiated with the microwave for a long time, so that the quality of the object may be deteriorated, and there is a problem that the processing time becomes longer.

  An object of the present invention is to provide a refrigerator-freezer equipped with a microwave processing device that improves power conversion efficiency, prevents damage to the microwave generator due to reflected power, and operates at high speed.

In the refrigerator-freezer according to the present invention, a microwave processing device using a semiconductor is mounted instead of a magnetron, and an object is processed using microwaves. Microwave generating means for generating a wave, a radiating section for radiating a microwave generated by the microwave generating means to an object, a detecting means for detecting reflected power from the radiating section, and the microwave generating means Control means for controlling
The control means causes the microwave generation means to radiate a microwave of the chirp signal from the radiating portion to the object, and processes the object based on a frequency at which the reflected power detected by the detection means is minimized or minimized. After determining the microwave frequency for the processing as the processing frequency, the microwave of the processing frequency is generated by the microwave generating means.

  As described above, since the microwave having the processing frequency determined based on the frequency at which the reflected power from the radiating unit is minimized or minimized is used for processing the object, the reflected power generated when the object is processed is reduced. The

Thereby, the power conversion efficiency of the microwave processing apparatus is improved. Further, even when the microwave generating means generates heat due to the reflected power, the amount of generated heat is reduced. As a result, breakage and failure of the microwave generation means due to the reflected power are prevented. The control means sets the power of the microwave radiated from the radiating unit to the target before processing the target to a value smaller than the power of the microwave radiated from the radiating unit to the target during processing of the target. Also good.

  In this case, the power of the microwave radiated from the radiating unit to the target object with the microwave of the chirp signal before the processing of the target part is smaller than the power of the microwave radiated when the target part is processed. It is possible to prevent the object from being processed by the microwave having a large electric power before the processing.

  Thereby, power consumption before the processing of the object is reduced, and the object is processed under undesired conditions and the quality of the object is prevented from being deteriorated. The treatment of the object may be a heat treatment, and the microwave processing apparatus may further include a heating chamber that accommodates the object for heating.

  In this case, the object can be heat-treated by accommodating the object in the heating chamber. Moreover, the installation space can be narrowed by using a semiconductor instead of the magnetron, and thus the capacity of the refrigerator can be secured, so that commercialization is easy.

  According to the present invention, the microwave having the processing frequency determined based on the frequency at which the reflected power from the radiating unit is minimized or minimized is used for the processing of the object. Therefore, the reflected power generated during the processing of the object is reduced. Reduced.

  Thereby, the power conversion efficiency of the microwave processing apparatus is improved, and damage and failure of the microwave generating means due to heat caused by the reflected power are prevented. In addition, since the microwave frequency is swept in a short time, it is possible to prevent deterioration of food and the like, and to provide a refrigerator-freezer equipped with a microwave processing apparatus that can be processed in a small size and at high speed.

The block diagram which shows the structure of the microwave generator which concerns on this embodiment Explanation of chirp signal The figure which shows the example of a FFT process result The flowchart which shows the control procedure of the microwave generator of FIG.

  Hereinafter, the microwave processing apparatus mounted in the refrigerator-freezer according to the present invention will be described.

(Embodiment 1) Description of Configuration FIG. 1 is a block diagram showing a configuration of a microwave processing apparatus mounted on a refrigerator-freezer. As shown in FIG. 1, the microwave processing apparatus according to the present embodiment includes a chirp signal generator 1, an amplifier 2, a circulator 3, a heating chamber 9, and a microcomputer 11. The heating chamber 9 includes an antenna 4 and an object. The microcomputer 11 includes a frequency determination process 5, an FFT process 6, an A / D converter 7, and a control unit 10.

The chirp signal generator 1 outputs a signal continuously variable with the frequencies f0, f1, f2,... Fn as shown in FIG. 2 by the linear frequency modulation method (details of the linear frequency modulation method and the chirp signal generator). In the case of using the frequency band ISM (Industrial Scientific and Medical) band, for example, the revised radar technology, published by the Institute of Electronics, Information and Communication Engineers (see P276), for example, at any set step in the entire frequency band of 2400 MHz to 2500 MHz. When the variable frequency can be generated as a continuous wave, for example, in a 10 MHz step, f0 = 2400 MHz, f1 = 2410 MHz, f2 = 2420 MHz ·· fn = 2500 MHz.

  Further, the chirp signal generator 1 can output a continuous wave having an arbitrary constant frequency according to a command from the microcomputer 11. The amplifier 2 amplifies the signal output from the chirp signal generator 1 to a desired power value.

  The circulator 3 functions to transmit the reflected wave from the antenna 4 to the A / D converter 7 while operating the amplifier 2 stably. The antenna 4 is installed in a heating chamber 9 made of a metal or a material that reflects electromagnetic waves, and functions to radiate a chirp signal amplified by the amplifier 2, and propagates, reflects, or directly passes through the heating chamber 9. An object 8 is irradiated with a chirp signal.

  Here, in the heating chamber 9, the natural frequency is determined by the natural value due to the structure and the position, size, composition, and the like of the object 8, and frequencies other than the natural frequency are reflected outside the heating chamber 9. For example, when the natural frequency is 2420 MHz and the chirp signal is output at 10 MHz step and f0 = 2400 MHz, f1 = 2410 MHz, f2 = 2420 MHz ·· fn = 2500 MHz, the power of f2 is absorbed in the heating chamber 9. The power of other frequencies is reflected and received by the antenna 4 and then transmitted to the microcomputer 11 via the circulator 3.

  In the microcomputer 11, when converted to a digital signal by the A / D converter 7 and then converted from the time axis to the frequency axis by the FFT processing 6, the power value of the reflected signal in frequency units can be obtained. In the above example, as shown in FIG. 3, only the natural frequency f2 = 2420 MHz in the heating chamber 9 results in the reflected power value being lower than the other f0, f1, f3... Fn. In the frequency determination process 5, the frequency at which the power value is minimum and minimum is examined based on the result of the FFT process 6.

  In the case of the above example, it is determined that the optimum frequency for heating the object 8 is f2 = 2420 MHz, and the control unit 10 sets the chirp signal generator 1 to emit a continuous wave with a frequency of 2420 MHz. At the same time, the amplifier 2 is adjusted to be larger than the power value when the chirp signal is output, and the object 8 is heated.

  In addition, the size of the microwave processing apparatus can be accommodated within the length × width × height = 10 × 10 × 2 cm because the component itself is small in the configuration as described above, and is generally small. Since the height direction can be made thinner than the size of magnetron, vertical x horizontal x height = 10 x 10 x 10 cm, it can be mounted without affecting the capacity value of the refrigerator.

  Next, the operation flow will be described.

  FIG. 4 is a flowchart showing a control procedure of the microcomputer 11 of FIG. The microcomputer 11 in FIG. 1 performs the following microwave processing when the heating of the object is commanded by the user's operation.

  As shown in FIG. 4, the microcomputer 11 controls the amplifier 2 by the control unit 10 to set a predetermined first output power. The first output power is smaller than the second output power described later. For example, when the microwave processing apparatus according to the present embodiment is applied to a microwave oven with a rating of 1000 W, the second output power is 1000 W, and the first output power may be a value smaller than this, It may be set to 1/5, 200 W, or 1/10, 100 W.

  Further, when the output power of the chirp signal generator 1 is 0.1 W and the first output power is 100 W, the amplifier 2 is set so that it can amplify 1000 times. Next, the control unit 10 sets the frequency of the microwave generated by the chirp signal generator 1 over the entire frequency band of, for example, 2400 MHz to 2500 MHz (this frequency band is called an ISM: Industrial Scientific and Medical band). In addition, in the case of 10 MHz steps, settings such as f0 = 2400 MHz, f1 = 2410 MHz, f2 = 2420 MHz ·· fn = 2500 MHz are performed, and the chirp signal generator 1 is turned on.

  For example, in the high-frequency heating device disclosed in Patent Document 1, the microwave frequency is swept in a predetermined frequency band, and the microwave frequency when the reflected power shows the minimum value is stored. When time is required, the entire ISM band requires 100 ms. However, when the microwave processing apparatus according to the present embodiment is applied, one sweep is sufficient and the time can be reduced to 10 ms.

  Next, the A / D converter 7 in FIG. 1 is turned on, the detected signal is subjected to FFT processing, the relationship between the reflected power and the frequency is calculated, and the result is stored. Note that the microcomputer 11 may store only the relationship between the reflected power and the frequency when the reflected power shows a minimum value, instead of storing the relationship between the reflected power and the frequency in the entire frequency band of the microwave frequency. Good. In this case, the use area of the storage device in the microcomputer 11 can be reduced.

  Subsequently, the frequency determination process 5 performs a frequency determination process for extracting a specific frequency from the ISM band. In this frequency determination process 5, for example, a specific reflected power (for example, a minimum value) is identified from the stored reflected power, and the frequency when the reflected power is obtained is extracted as the main heating frequency.

  In the example of FIG. 3, 2420 MHz is set as the main heating frequency. Next, the control unit 10 sets a predetermined second output power. This 2nd output electric power is electric power for heating the target object arrange | positioned in the heating chamber 9 of FIG. Then, the control unit 10 sets the chirp signal generator 1 to a continuous wave of the main heating frequency, and then sets the amplifier 2 so as to have the second output power.

  For example, when the output power of the chirp signal generator 1 is 0.1 W and the second output power is 1000 W, the amplifier 2 is set so that it can be amplified 10,000 times. Next, the chirp signal generator 1 is turned on to radiate microwaves of the main heating frequency from the antenna 4 into the heating chamber 9. Thereby, the target object arrange | positioned in the heating chamber 9 is heated (main heating).

Hereinafter, examples of correspondence between each component of the claims and each part of the embodiment will be described, but the present invention is not limited to the following examples.
In the present embodiment, the microwave generation means corresponds to the chirp signal generation device 1, the amplifier 2, and the circulator 3, the radiation section corresponds to the antenna 4, and the detection means includes frequency determination processing included in the microcomputer 11. 5, the FFT processing 6 and the A / D converter 7, and the control means corresponds to the control unit 10 included in the microcomputer 11.

  INDUSTRIAL APPLICABILITY The present invention can be used for processing devices that generate reflected power, such as various heating devices, plasma generators, drying devices, and devices that promote enzyme reactions.

DESCRIPTION OF SYMBOLS 1 Chirp signal generator 2 Amplifier 3 Circulator 4 Antenna 5 Frequency determination process 6 FFT process 7 A / D converter 8 Target object 9 Heating chamber 10 Control part 11 Microcomputer

Claims (4)

A refrigerator-freezer equipped with a microwave, a microwave generating means for generating a microwave, a radiating portion for radiating a microwave generated by the microwave generating means to an object, and a reflected power from the radiating portion Detection means for detecting the control, and control means for controlling the microwave generation means,
The control means causes the microwave generation means to radiate a microwave of the chirp signal from the radiating portion to the object, and processes the object based on a frequency at which the reflected power detected by the detection means is minimized or minimized. A microwave refrigerator having a processing frequency is determined by the microwave generating means after determining the frequency of the microwave for processing as a processing frequency. The control means determines the processing frequency so that the power of the microwave radiated from the radiation unit to the object is smaller than the microwave power of the processing frequency radiated from the radiation unit to the object. The refrigerator-freezer according to claim 1, wherein the refrigerator is set to a value. The refrigerator-freezer according to claim 1 or 2, wherein the microwave generating means uses a semiconductor. 4. The refrigerator-freezer according to claim 1, wherein the processing of the object is a heat treatment, and further includes a heating chamber that accommodates the object. 5.

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