• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention relates to a microwave oven, wherein a spinneret of a first output waveguide and a spinneret of a second output waveguide are formed on a cavity wall surface in an upward direction and a cavity wall surface in a downward direction based on a feed hole of an input waveguide. The first output waveguide and the second output waveguide inject the microwaves having electric fields of opposite phases into the cavity, thereby minimizing the impedance change caused by the variation of the food load, thereby keeping the output of the microwave constant regardless of the food load. At the same time, the electric field distribution inside the cavity can be kept constant.
    公开号:KR19990031997A
    申请号:KR1019970052913
    申请日:1997-10-15
    公开日:1999-05-06
    发明作者:이응섭
    申请人:윤종용；삼성전자 주식회사；
    IPC主号:
    专利说明:

    microwave
    The present invention relates to a microwave oven for heating and cooking food by applying microwaves to food, and more particularly, to minimize the impedance change of the waveguide due to the change in the load of food to be cooked, thereby reducing the output of the microwave regardless of the food load. The present invention relates to a microwave oven configured to maintain a constant and maintain a constant electric field distribution in a cavity.
    In general, the microwave oven is configured to inject microwaves generated from the magnetron into the cavity through the waveguide to dielectrically heat foods placed in the cavity.
    FIG. 1 is a schematic cross-sectional view of a microwave waveguide according to a first embodiment, and FIG. 2 is an injection structure analysis diagram of the waveguide shown in FIG. 1, in which a magnetron 3 is inserted into one side of the waveguide 1. A magnetron insertion hole 9 is formed, and on the other side of the waveguide 1, a rectangular opening 7 for injecting microwaves generated by the magnetron 3 into the cavity is formed.
    The microwaves generated by the magnetron 3 are injected into the cavity 5 through the waveguide 1, and the microwaves are applied to food in the cavity 5 to dielectrically heat food.
    Here, as shown in Figure 2, the power (power) of the magnetron (3) P in The output of the specific position inside the cavity 5 P out Speaking of P out Is obtained by the following equations (1) to (3).
    P in = E s 2
    E y = E s sin (x)
    P out = (E y ) 2 = (E s sin (x)) 2 = E s 2 sin (x) 2
    In Equations 1 to 3, E s Is the electric field energy formed by the microwaves generated in the magnetron 3, that is, the input electric field energy, E y Is the electric field energy, i.e., the output electric field energy, at a specific position inside the cavity 5.
    The output of the magnetron 3 is the electric field strength formed by the microwaves generated from the magnetron E s Is obtained by squared.
    In addition, since the microwave generated by the magnetron 3 has a specific phase, that is, a sine wave, the electric field energy at a specific position inside the cavity 5. E y Is the electric field energy formed by the microwaves E s Is the form of the product of the sine term sin (x) multiplied by this field energy E y Squared output at a specific location inside the cavity P out to be.
    Therefore, the output at a specific position inside the cavity 5 P out Output of the magnetron P in The sinus term sin (x) is multiplied by the sinus term sin (x). The sinus term sin (x) is changed in value according to the load variation of the food to be cooked. Print P out It will also change with load fluctuations.
    As described above, the impedance characteristics of the waveguide according to the load variation of the food can be shown as shown in the polar chart of FIG. 3. In FIG. 3, the load is 2000cc in the state in which the microwave frequency range is 2.44 ~ 2.47GHz. The waveguide impedance characteristics in the case of water, 1000 cc water, 500 cc water, and 100 cc water are shown.
    As shown in FIG. 3, when the load is 2000 cc of water, the standing wave ratio (VSWR: Voltage Standing Wave Ratio), that is, the impedance of the waveguide is decreased, while the output of the microwave is increased, while the load is 100 cc of water. The standing wave ratio VSWR, that is, the impedance of the waveguide is increased, so that the output of the microwave is reduced.
    In other words, when the food load is large, the output of the microwave is rather high, but when the load is low, the impedance of the waveguide increases and the output of the microwave is lowered.
    In addition, there is a problem in that the impedance change of the waveguide due to the change of the load of food to be cooked is greatly generated, so that the electric field distribution inside the cavity is not constant.
    In addition, in order to improve the output of the microwave oven, the impedance of the waveguide and the impedance of the cavity must be matched. The waveguide of the above structure is designed to have a specific cavity and impedance matching, so that one waveguide is applied to various types of cavities. There was a difficulty in designing a waveguide separately for each cavity.
    On the other hand, the microwave wave guide system disclosed in Japanese Patent Laid-Open No. 6-111933 dated April 22, 1994 improves the uniform heating performance of food in the cavity of the microwave oven, and shortens the waveguide to make the electric parts. In order to facilitate the arrangement, as shown in Figure 4, having a pair of different radio wave supply holes (11a, 11b) on one side wall, the cavity 12 for storing the food to be cooked, and the radio wave supply It is isolated from the side wall which has the balls 11a and 11b, and is located between the said radio wave supply holes 11a and 11b, λ g From the magnetron 14 and the antenna 13 generating microwaves having a frequency of λ g It is isolated at a distance of / 4, has a short circuit surface parallel to the antenna 13, covers the radio wave supply holes 11a and 11b, supports the magnetron 14, and the radio wave supply hole 11a. And a waveguide 15 for guiding the microwaves passing through 11b) to the cavity 12, and forming a standing wave in the waveguide 15 with a radio wave generated from the magnetron 14, and then supplying the radio wave. The food is uniformly heated by spinning through the balls 11a and 11b into the cavity 12.
    However, in the conventional microwave microwave wave guide system, a pair of upper electric wave supply holes 11a and 11b are formed on one side wall of the cavity 12, and the microwave generated from the magnetron 14 is used. By radiating the inside of the cavity 12 through a pair of radio wave supply holes 11a and 11b, only the microwave dispersion performance is improved to improve the uniform heating performance of the food. There was a problem in not responding properly.
    The present invention is to solve the problems of the prior art as described above, by improving the structure of the waveguide to minimize the impedance change caused by the change in the load of food to be cooked to maintain a constant output of the microwave regardless of the food load The purpose is to provide a microwave oven.
    Another object of the present invention is to provide a microwave oven which maintains a constant electric field distribution inside the cavity by minimizing the impedance change caused by the variation of the food load.
    Microwave oven according to the present invention for achieving these objects, the input waveguide coupled to the magnetron to supply the microwaves generated in the magnetron through a feed hole, and is communicated to the feed hole of the input waveguide is transmitted from the input waveguide In a microwave oven comprising a first and a second output waveguide for separating the microwaves into different phases and spraying the inside of the cavity to dielectrically heat food.
    The spinneret of the first output waveguide and the spinneret of the second output waveguide are formed on the cavity wall surface in the upward direction and the cavity wall surface in the downward direction based on the feed hole of the input waveguide, respectively, so that the first output waveguide and the second output waveguide are respectively formed. The output waveguide injects microwaves with electric fields of opposite phases into the cavity, minimizing the impedance change caused by the variation of the food load, thereby maintaining the output of the microwave constant regardless of the food load. The electric field distribution of can be kept constant.
    1 is a schematic cross-sectional view of a microwave waveguide according to a conventional embodiment,
    2 is an injection structure analysis diagram of the waveguide shown in FIG. 1;
    FIG. 3 is a polarity diagram illustrating impedance characteristics of loads of the waveguide shown in FIG. 1;
    4 is a schematic cross-sectional view of a microwave oven according to a conventional example 2;
    5 is a schematic cross-sectional view of a microwave oven according to the present invention;
    6 is a detailed view of the waveguide shown in FIG. 5;
    7 is a detailed view of the spinnerette according to the present invention;
    8 is an injection structure analysis diagram of the waveguide according to the present invention;
    9 is an impedance polarity diagram of a microwave oven according to the present invention;
    10 is a load-specific impedance polarity diagram of a microwave oven according to the prior art,
    11 is an impedance polarity diagram for each load of the microwave oven according to the present invention;
    12 is a graph comparing the efficiency of the microwave oven and the microwave according to the prior art of the present invention,
    Figure 13 is a state diagram measuring the microwave injection pattern for each load in the microwave oven of the present invention,
    14 is a graph comparing the deviation of the milk temperature in the microwave oven according to the present invention and the prior art.
    <Explanation of symbols for main parts of the drawings>
    16: Cavity 18: Magnetron
    20: waveguide 21: input waveguide
    23: first output waveguide 25: second output waveguide
    27: power supply port 29, 31: spinneret
    33: cavity wall
    Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
    5 is a schematic cross-sectional view of the microwave oven according to the present invention, and FIG. 6 is a detailed view of the waveguide shown in FIG. 5, and the microwave oven shown in FIGS. 5 and 6 sprays microwaves into the cavity from the side of the cavity. A waveguide is provided.
    As shown in Figure 5, the microwave of the present invention, the cavity 16 for storing the food to be cooked, λ g A magnetron 18 for generating microwaves having a frequency of and a waveguide 20 for guiding the microwaves generated by the magnetron 18 into the cavity 16 are provided.
    As shown in FIG. 6, the waveguide 20 includes an input waveguide 21, a first output waveguide 23, and a second output waveguide 25. In combination with the magnetron 18, the microwaves generated by the magnetron 18 are supplied to the first and second output waveguides 23 and 25.
    The first output waveguide 23 is configured to spray the microwaves supplied through the feed hole 27 of the input waveguide 21 into the cavity through the spinneret 29, and the second output waveguide 25 The radiator 31 has an electric field in a phase opposite to that of the microwaves injected through the feed hole 27 of the input waveguide 21 and injected into the cavity through the first output waveguide 23. It is intended to spray through the cavity.
    In addition, as shown in FIG. 7, the spinneret 29 of the first output waveguide 23 and the spinneret 31 of the second output waveguide 25 are provided with a feed hole 27 of the input waveguide 21. ) Are formed on the cavity wall surface 33 in the upper direction and the cavity wall surface 33 in the downward direction, respectively, to inject microwaves having electric fields of opposite phases into the cavity 16.
    At this time, the spinneret 29 of the first output waveguide 23 and the spinneret 31 of the second output waveguide 25 are each a predetermined distance up and down from the center of the feed hole 27 of the input waveguide 21. (d1, d2), that is λ g The center of the lower end of each of the spinnerets 29 and 31 is formed at a distance of / 4.
    That is, the spinneret 29 of the first output waveguide 23 and the spinneret 31 of the second output waveguide 25 are each other. λ g It is formed by a length of / 2.
    In addition, the spinneret 29 of the first output waveguide 23 and the spinneret 31 of the second output waveguide 25 are formed in the same shape, and the left and right sides are formed symmetrically with each other.
    At this time, the left and right lengths of the spinneret 29 of the first output waveguide 23 and the spinneret 31 of the second output waveguide 25 are each a + b = λ g / 4, a '+ b' = λ g / 4 is the sum of the left and right λ g It is formed so that it becomes / 2.
    In addition, the upper end width c of the spinneret 29 of the first output waveguide 23 and the spinneret 31 of the second output waveguide 25 is λ g / 8, and the left and right width e is c / 2, λ g / 16 is formed.
    When explaining the operation and effect of the present invention made as described above in detail.
    In the present invention, the microwave generated from the magnetron 18 is transmitted to the first output waveguide 23 and the second output waveguide 25 through the input waveguide 21.
    That is, the microwave generated by the magnetron 18 is partially transmitted to the first output waveguide 23 through the feed hole 27 of the input waveguide 21, and the remaining portion is transmitted to the second output waveguide 25. will be.
    The first output waveguide 23 injects the microwaves transmitted through the input waveguide 21 into the cavity through the spinneret 29, and the second output waveguides 23 and 25 are the input waveguides. Microwaves transmitted through the 21 are injected into the cavity through the spinneret 31.
    At this time, the output of the microwave oven is represented as the sum of the microwave energy injected from the radiators 29 and 31 of the respective output waveguides 23 and 25, and the electric field energy of the microwaves injected through the radiators 29 and 31 respectively. Since the symmetrical magnitude and phase of each other, the magnitude of the microwave energy is the sum of the microwaves injected through each of the spinnerets 29 and 31 and the phases cancel each other to generate a constant output.
    That is, as shown in FIG. 8, the microwaves emitted from the spinneret 29 of the first output waveguide 23 are more than the microwaves supplied from the feeder 27 of the input waveguide 21. λ g After / 4 has a magnitude of the electric field gradually increasing, the microwave injected from the spinneret 31 of the second output waveguide 25 is more than the microwave supplied from the feed hole 27 of the input waveguide 21 λ g Since the electric field is injected into the cavity with the magnitude of the electric field becoming smaller in the / 4 field, the two electric fields are opposite to each other.
    Meanwhile, the waveguide impedance of the present invention has a combined impedance of the spinneret 29 of the first output waveguide 23 and the spinneret 31 of the second output waveguide 25, as shown in FIG. When the radiation port 29 of the first output waveguide 23 is blocked, the impedance is at the position of ①, and if the radiation port of the second output waveguide 25 is blocked, the impedance is at the position of ②, and the two radiation holes ( 29, 31) is the composite impedance ③.
    In comparison with the load-specific impedance, as shown in FIG. 10, in the conventional microwave oven, the impedance change of the high load (1000 to 2000 cc) and the low load (100 to 500 cc) is large, whereas the impedance of the present invention is shown in FIG. As shown, it remains constant regardless of load fluctuations.
    12 is a graph comparing the efficiency of the microwave oven according to the present invention and the microwave oven according to the prior art, and the microwave oven according to the present invention exhibits high efficiency even at a low load due to less amount of reflected waves compared to the microwave oven according to the prior art. It can be seen that there is almost no variation in the efficiency caused by the load change.
    In addition, the present invention has the advantage that uniform heating is possible because the microwaves are properly injected from the spinneret 29 of the first output waveguide 23 and the spinneret 31 of the second output waveguide 25 according to the load amount. .
    That is, Figure 13a to 13d is a state diagram measuring the adverb shape for each load, by measuring the temperature using an infrared camera to install the ferrite material with good electromagnetic wave absorption in the radiation sphere on the wall after the magnetron operation after It is measured.
    As shown in FIGS. 13A and 13B, at no-load and low-load 150cc, cooking is performed by spraying microwaves at the spinneret 31 of the second output waveguide 25 mainly located at the bottom of the cavity, and FIG. 12C. As shown in FIG. 12C, the intermediate load 500cc is cooked by spraying the microwaves 29 and 31 of the first and second output waveguides 23 and 25 appropriately by dividing the microwaves, as shown in FIG. 12D. Similarly, it can be seen that at high load 1000cc, microwaves are injected from the spinneret 29 of the first output waveguide 23 located mainly in the cavity.
    Figure 14 is a microwave oven according to the prior art and the milk in a milk bottle in the microwave oven according to the present invention by measuring the maximum temperature deviation of the top and bottom of the milk in the milk bottle with an infrared camera, according to the present invention It can be seen that the maximum temperature deviation of the top and bottom of the milk in the microwave bottle is small.
    As described above, the present invention divides the microwaves generated by the magnetron into several branches and sprays them into the cavity, and the divided microwaves are sprayed into the cavity to have different phases, thereby changing the load of food to be cooked. By minimizing the impedance change of the waveguide, the output of the microwave can be kept constant regardless of the food load, and the electric field distribution in the cavity can be kept constant.
    权利要求:
    Claims (4)
    [1" claim-type="Currently amended] The input waveguide coupled to the magnetron to supply the microwaves generated by the magnetron through the feeder, and the microwaves communicated to the feeder of the input waveguide are separated from each other in different phases and sprayed into the cavity to feed the food. In a microwave oven comprising a first and a second output waveguide for dielectric heating,
    The spinneret of the first output waveguide and the spinneret of the second output waveguide are formed on the cavity wall surface in the upward direction and the cavity wall surface in the downward direction based on the feed hole of the input waveguide, respectively, so that the first output waveguide and the second output waveguide are respectively formed. A microwave oven in which an output waveguide injects microwaves having electric fields of opposite phases into the cavity.
    [2" claim-type="Currently amended] The method of claim 1,
    The spinneret of the first output waveguide and the spinneret of the second output waveguide are formed in the same shape, λ g Microwave oven, characterized in that formed by two apart from each other.
    [3" claim-type="Currently amended] The method of claim 2,
    The spinneret of the first output waveguide and the spinneret of the second output waveguide are respectively up and down from the center of the feeder of the input waveguide. λ g Microwave oven characterized in that the bottom center of each spinneret is located at a distance of / 4.
    [4" claim-type="Currently amended] The method according to any one of claims 1 to 3,
    Each of the spinneret is characterized in that the left and right sides are formed symmetrically to each other.
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    同族专利:
    公开号 | 公开日
    KR100239552B1|2000-03-02|
    GB9727506D0|1998-02-25|
    CN1214431A|1999-04-21|
    GB2330508A|1999-04-21|
    US5935479A|1999-08-10|
    GB2330508B|1999-10-06|
    JPH11135251A|1999-05-21|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1997-10-15|Application filed by 윤종용, 삼성전자 주식회사
    1997-10-15|Priority to KR1019970052913A
    1999-05-06|Publication of KR19990031997A
    2000-03-02|Application granted
    2000-03-02|Publication of KR100239552B1
    优先权:
    申请号 | 申请日 | 专利标题
    KR1019970052913A|KR100239552B1|1997-10-15|1997-10-15|Microwave oven|
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