JP3796856B2 - High frequency heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency heating apparatus in which high-frequency induction heating means and high-frequency dielectric heating means are combined.
[0002]
[Prior art]
The eating habits in recent years have become diversified with westernization, and processed foods such as frozen and refrigerated are rapidly increasing. In order to reheat these processed foods in a short time, microwave ovens and microwave ovens are attracting attention again. However, although the performance of the microwave oven has been improved, the problem that the baking power is insufficient and the cooking time is too long has hardly been improved. However, various proposals have heretofore been made for a high-frequency heating apparatus that combines high-frequency induction heating and dielectric heating by microwaves aimed at solving the above problems.
[0003]
As a typical conventional example, Japanese Patent Laid-Open No. 63-225495 is shown in FIG. As shown in FIG. 6, the high-frequency heating device includes a partition plate 41 made of a heat-resistant ceramic material or the like on which a heating dish 40 in which a food a is placed is placed in the heating chamber 1, and can be opened and closed on the partition plate 41. The dome-shaped heating chamber door 42 is composed of high-frequency dielectric heating means and high-frequency induction heating means. The high-frequency dielectric heating means rotates the rotating antenna 44 connected to the drive motor 43 provided at the lower part of the heating chamber 1, while the microwave generated in the magnetron 45 is passed through the waveguide 46 through the heating chamber 1. Configured to propagate to. Further, the high frequency induction heating means surrounds a heating coil 47 and the magnetic flux transmitting ferrite core 48 joined to the lower part of the heating coil 47 between the partition plate 41 and the rotating antenna 44 in a shield cover 49 for shielding radio waves. And are arranged and configured to be joined to the lower surface of the partition plate 41. The heating coil 47 induces a high-frequency magnetic field by the energized current and generates an eddy current in the heating dish 40 provided on the partition plate 41 to heat it.
[0004]
[Problems to be solved by the invention]
However, in the conventional configuration, first, the height of the high-frequency heating device is high. That is, the configuration of the heating chamber door 42 constituting the heating chamber 1 has at least the height of the central portion increased in order to efficiently irradiate the food disposed in the center of the heating chamber with microwaves and to make the distribution uniform. By adopting a dome shape, the microwave cavity space is increased. Furthermore, since the functional element parts such as the drive motor 43, the waveguide 46, the rotating antenna 44, the heating coil 47, and the ferrite core 48 are each laminated, the height of the entire apparatus increases, and the kitchen table and It was not easy to use on the table, and it was not easy to place because of its large size.
[0005]
Second, in the high frequency induction heating means, the configuration in which the heating coil 47 and the magnetic shielding ferrite core 48 are surrounded by the shield cover 49 is such that the microwave is heated so that the heating coil 47 and the ferrite core 48 are not damaged by being heated. Although it is for shielding, if the shielding performance of the shield cover 49 is increased in order to shield the microwave, the high frequency magnetic field is also shielded, the efficiency of induction heating is lowered, and both are extremely difficult to be heated. was there.
[0006]
[Means for Solving the Problems]
The present invention is to solve the above-mentioned problems, and the heating chamber is made thin with a rectangular cross section, and the electromagnetic wave is also applied to the lower portion facing the heating chamber, which is the main radio wave propagation space, that is, the electromagnetic shielding chamber inside the machine chamber. Propagation space is provided, microwave propagation space (hereinafter referred to as a cavity) is formed above and below the partition plate forming the boundary wall between the heating chamber and the machine room, and a dielectric material placed on the partition plate is used. An annular heating plate made of a metal material is provided on the bottom surface of the heating plate, and a radio wave propagation path is formed in the center hole and outer periphery of the heating plate to form a passage through which microwaves can freely propagate between the upper and lower cavity spaces. It is a thing. Further, the arrangement of the high-frequency induction heating means and the high-frequency dielectric heating means is arranged side by side without being laminated, so that the height of the machine room is made low and a thin flat structure.
[0007]
According to the present invention, since the heating device can be made thin, it is compact and uncomfortable even when placed on a kitchen table or a table, and the usability is improved. Furthermore, although the heating chamber has a thin and flat configuration, the microwave propagates between the upper and lower cavities through the radio wave propagation path formed in the central hole and the outer periphery of the heating plate, so that a large cavity space is formed as a whole. Therefore, efficient heating is possible regardless of the size, shape, and type of the load of the food to be heated.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention includes a heating chamber composed of a heating chamber door having a rectangular cross section, a machine room provided at the lower part of the heating chamber, an upper plate made of a metal material forming a boundary wall between the heating chamber and the machine room, and A partition plate made of a heat-resistant dielectric material, a heating pan made of a heat-resistant dielectric material placed on the partition plate, an annular heating plate made of a metal material attached to the front surface or the back surface of the heating plate, and the machine An electromagnetic shielding chamber that is provided in the room and whose outer peripheral portion is in electrical contact with the upper plate, a heating coil having a coil hollow portion that is insulated from the lower surface of the partition plate, and an outer surface and a bottom surface of the heating coil Radio wave propagation path A formed with a gap of a certain level or more between the inner wall surface of the electromagnetic shielding chamber, a magnetron for generating microwaves, and a guide provided side by side with the outer peripheral wall of the electromagnetic shielding chamber. and wave tube, to the upper plate Vignetting and configured to have a feed opening which opens into the heating chamber.
[0009]
And since the whole heating device was flat and thin and could be downsized, the storage space became smaller and lower, so there was no sense of incongruity and ease of use was improved. In terms of functionality, microwaves can be reflected and propagated efficiently in the heating chamber by combining the upper and lower cavities, the structure of the radio wave propagation path, the heating pan made of dielectric material, and the annular heating plate. Improved, rapid heating and uniform heating became possible.
[0010]
Further, the gap dimension of the radio wave propagation path A provided between the outer surface of the heating coil and the inner wall surface of the electromagnetic wave shielding chamber is held at least 10 mm or more and 50 mm or less.
[0011]
Even if a ferrite core is not attached to the lower part of the heating coil, for example, a high-frequency induction heating characteristic with a high efficiency of about 80% can be secured if the gap dimension of the radio wave propagation path is secured to 25 mm or more. Furthermore, as a matter of course, since the ferrite core is not attached, the ferrite core absorbs the microwave, and the heat generation damage and the characteristic deterioration do not occur.
[0012]
In addition, a plurality of annular heating plates made of a metal material are provided on either the front surface or the back surface of a heating plate made of a heat-resistant dielectric material, and have a certain gap, that is, an annular radio wave propagation path B. The heating coil is arranged so that the center of the heating coil and the center of the annular heating plate substantially coincide with each other.
[0013]
Then, in addition to the cavities formed above and below the heating dish and the radio wave propagation path A, the microwaves are cavities around the heating dish by the combination of the annular radio wave propagation path B provided on the bottom and back of the heating dish. , Because it can efficiently reflect and propagate between the radio wave propagation path A and the annular radio wave propagation path B, the food placed on the heating pan can be efficiently cooked at high speed by high-frequency dielectric heating with high heating power and uniformity. It has become possible.
[0014]
Further, the power supply opening provided on the upper plate made of a metal material forming the boundary wall between the heating chamber and the machine chamber is opened at least larger than the external dimensions of a container such as a general 200 ml milk bottle. Te provided, can pre Symbol feed port container length storage height areas such as at least the milk bottle with the bottom surface of the waveguide which is attached to the machine room to continuously provided with a top plate of the heating chamber door structure It was.
[0015]
And, 200ml type milk bottles and tall containers such as sake bottles that are routinely used in general households that cannot be placed because of the height of the heating chamber alone are stored by placing them in the waveguide. It becomes possible. Moreover, since the waveguide portion is in the region where the microwave electric field is the highest, it can be heated concentratedly and effectively, so that it can be heated faster than it is placed in the heating chamber.
[0016]
In addition, a high-temperature radiation type electric heater is mounted on the inner surface of the inner wall of the top plate of the heating chamber door via a heat insulating portion or the like.
[0017]
And since the height of a reflector and a partition plate is comprised below the height of the general 200 ml type milk bottle etc. like the conventional height of a heating chamber, it was arrange | positioned on a heating pan. The distance between the food and the electric heater is reduced, and the high-temperature infrared rays emitted from the electric heater are radiated powerfully and effectively on the upper part of the food, and the top baking is efficiently completed in a short time and uniformly. It is. Furthermore, by combining with the high frequency induction heating means, it is possible to provide a very high-power microwave oven that effectively bake the upper and lower surfaces of food.
[0018]
Embodiments of the present invention will be described below with reference to the drawings.
[0019]
Example 1
1 is a longitudinal view of a high-frequency heating device according to a first embodiment of the present invention.
[0020]
In FIG. 1, a heating chamber 1 for storing food a includes an upper plate 3 made of a metal material and a partition plate 4 made of a heat-resistant dielectric material that form the upper wall of a machine room 2 in which each functional component is disposed. The plate 3 and the partition plate 4 are constituted by a heating chamber door 5 having a rectangular cross section surrounding the top and a flat hat shape. 6 is a heating coil made of a copper wire made of a good conductor metal with a bare wire and a rectangular or flat cross section. The heating coil is vertically arranged with a constant pitch across an insulator (not shown) such as soft mica. It is formed in a substantially donut shape by winding in a spiral shape. The heating coil 6 is disposed so as to be in contact with the lower surface of the partition plate 4 and is surrounded by a coil case 7 made of a heat-resistant dielectric material, and is fixed on the bottom surface of the electromagnetic wave shielding chamber 8 via a plurality of columns 9. Has been. The electromagnetic shielding chamber 8 is made of a non-magnetic good electrical conductor metal such as copper or aluminum in a concave shape, and its outer peripheral portion is in electrical contact with the upper plate 3 of the machine chamber 2. A coil hollow portion 10 through which microwaves propagate is provided at the center of the heating coil 6. The heating coil 6 is disposed in the electromagnetic shielding chamber 8, and a space between the bottom and outer surfaces of the heating coil 6 and the inner wall surface of the electromagnetic shielding chamber 8, that is, a radio wave propagation path A is configured. Therefore, when the heating chamber 1 is an upper cavity, the radio wave propagation path A functions as a lower microwave cavity. Reference numeral 11 denotes a heating pan made of a heat-resistant dielectric material such as ceramic, and a heating plate 12 (metal film or thin plate) made of a magnetic metal is vapor-deposited, fired or mounted on the front or back surface of the bottom surface. Reference numeral 13 denotes a power feeding port for feeding the microwave radiated from the antenna 15 of the magnetron 14 into the heating chamber 1 through the waveguide 16. The power supply port 13 is provided in a part of the upper plate 3 of the machine chamber 2 so that the outer peripheral wall of the electromagnetic wave shielding chamber 8 and the waveguide 16 are arranged side by side. Reference numeral 17 denotes a feed port lid with a handle made of a heat-resistant dielectric material that opens and closes the feed port 13. An antenna housing portion 18 is mounted on the wall surface of the waveguide 16 so that the antenna 15 portion of the magnetron 14 does not protrude into the space of the waveguide 16. Reference numeral 19 denotes a recess for placing the heating pan 11 at a fixed position in the center of the partition plate 4, which is attached to a seat portion 20 provided on the outer periphery of the electromagnetic shielding chamber 8 with a heat resistant inorganic adhesive. Therefore, the partition plate 4 is in a fixed state without rotating. Reference numeral 21 denotes a flat portion provided on the entire circumference of the heating chamber door 5 and prevents leakage of microwaves filling the heating chamber 1 together with the choke portion 22 disposed on the outer periphery of the upper plate 3 of the machine chamber 2. Reference numeral 23 denotes a handle, and 24 denotes a plurality of ventilation holes provided on the top plate 3 of the heating chamber door 5. Reference numeral 26 denotes a hinge for opening and closing the heating chamber door 5. Two inverter power sources (not shown) for generating a high-frequency current are provided exclusively for the magnetron 14 and the heating coil 6, respectively, or one is provided and the magnetron 14 and the heating coil 6 are both used. Although the number may be individual, the former is more reasonable as a combined cooking device for higher heating, cooking menu development, and high-speed cooking.
[0021]
Next, the operation will be described. First, when the food a is placed on the heating pan 11 disposed in the heating chamber 1 and power is applied to an inverter power supply (not shown), a high voltage is supplied to the magnetron 14, and the magnetron 14 is connected to the antenna 15. More microwaves are generated. The microwave is supplied into the heating chamber 1 through the waveguide 16 and the power supply port 17, the heating chamber 1 having a rectangular cross section, the space of the so-called upper and lower cavities functioning by being constituted by the radio wave propagation path A, It effectively propagates and irradiates the food material a through the coil hollow portion 10 of the heating coil 1 without being attenuated by radio waves. Therefore, although the heating chamber 1 has a flat and thin configuration, the food a is heated and heated with high efficiency and uniformity, and is rapidly heated and cooked.
[0022]
On the other hand, when a high frequency current is also supplied to the heating coil 6 from the inverter, the heating coil 6 generates a high frequency magnetic field, inducing an eddy current in the entire bottom surface of the heating dish 11, and the surface of the heating dish 11 rapidly rises to a high temperature. When heated, the bottom surface of food a is heated and burnt. It is also possible to operate microwaves and electromagnetic induction heating at the same time. In this case, the internal heating of the food a and the baked cooking of the bottom are promoted at the same time with high efficiency and high heating power. It can be cooked.
[0023]
In terms of structure, since the entire apparatus is flat and small and has a low configuration, there is no installation space on the kitchen table or table, and there is no sense of incongruity. In particular, because of its low height, cooking work is easy, convenient, and practical.
[0024]
(Example 2)
FIG. 2 shows the result of experimentally determining the relationship between the distance between the heating coil 6 and the inner wall surface of the electromagnetic wave shielding chamber 8 of the second embodiment of the present invention, that is, the gap of the radio wave propagation path A, and the induction heating efficiency. .
[0025]
According to FIG. 2, the material of the electromagnetic wave shielding chamber 8 is made of a non-magnetic good electric conductor material, such as aluminum, and the gap of the radio wave propagation path A is kept at 10 mm or more, so that the lower part of the heating coil 6 Even if no ferrite or the like having a high magnetic flux permeability was attached to the heating efficiency, it was possible to secure a heating efficiency of about 70%. This efficiency is 45% of the efficiency of a general gas stove, or 50 to 70% or more of the heating efficiency of a halogen stove using an electric stove or a halogen lamp. However, the conventional electromagnetic cooker is used with a short function only for induction heating, and its heating efficiency is about 60% or more. Therefore, in order to obtain the heating efficiency equivalent to that of the electromagnetic cooker, it is preferable to secure the dimension of the radio wave propagation path A to 15 to 25 mm or more. These dimensions should be determined by the purpose of the product, thin and small size, manufacturability, price, quality, etc. Judging from its effects, the practical range should be 10 mm or more and 50 mm or less. Considered reasonable in design. If the electromagnetic shielding chamber 8 is made of an iron-based material, the heating efficiency is reduced by about 20% or more compared to the copper-based material. Therefore, the gap of the radio wave propagation path A needs to be about twice as large. The height of the machine room 2 also needs to be increased correspondingly, and the cooking equipment main body is enlarged accordingly, which is not practical.
[0026]
Example 3
FIG. 3 is a partial cross-sectional view showing a main part of the heating plate part mounted on a part of the bottom surface of the heating dish.
[0027]
According to FIG. 3, a plurality of annular heating plates (metal thin films or metal thin plates) 27 made of a metal material are provided at regular intervals on either the front surface or the back surface of the heating pan 11 made of a heat-resistant dielectric material. Are mounted concentrically (processing such as vapor deposition, firing or bonding), arranged so that the center of the heating coil 6 and the center of the annular heating plate 27 substantially coincide, and the annular A plurality of annular radio wave propagation paths B are provided between the heating plate 27 and the heating plate 27 located outside thereof. An unprocessed portion 28 not provided with the heating plate 27 is provided at the central portion of the heating dish 11.
[0028]
Therefore, in addition to the heating chamber 1 on the partition plate 4 and the upper and lower cavities functioning in the radio wave propagation path A, the microwave is generated by the combination of the annular radio wave propagation path B provided on the bottom surface of the heating pan 11. Since the reflecting plate can be efficiently reflected and propagated between the upper and lower cavities, the radio wave propagation path A, and the annular radio wave propagation path B with the heating dish 11 as an axis, the food a placed on the heating dish 11 can be efficiently processed from thawing to cooking. In addition, high-speed cooking by uniform high-frequency dielectric heating with high heating power has become possible.
[0029]
In addition, since the thin heating plate 27 having a small heat capacity is attached only to the surface of the heating dish 11, the bottom surface of the heating dish 11 can be expected to increase in temperature instantaneously and the absolute temperature becomes high, and is placed on the heating dish 11. The food a can be burnt efficiently in a short time. Furthermore, the action of the microwave effectively heating and cooking the inside of the ingredient a is promoted by the radio wave propagation path B, and can be cooked deliciously in a short time.
[0030]
(Example 4)
FIG. 4 is a cross-sectional view of the main part in the vicinity of the power feeding port 13 and the waveguide 16.
[0031]
According to FIG. 4, the opening size of the power feeding port 13 is larger than at least a general 200 ml milk bottle b or sake bottle sake and the like, and is opposed to the top plate 5 of the heating chamber door 5 and the power feeding port 13. The height of the waveguide 16 with respect to the bottom surface can accommodate at least the entire height of the milk bottle b and the like, and the antenna 15 portion of the magnetron 14 does not protrude into the space portion of the waveguide 16. The magnetron 14 is arranged via the storage unit 18.
[0032]
Although the apparatus main body becomes a flat structure by the said structure, tall small containers and small foodstuffs, such as milk bottle b, sake bottle, and a cup, can be arrange | positioned easily. Further, since heating is performed in and near the waveguide 16 having the strongest high frequency, rapid heating can be performed with high efficiency. Further, the water can be directly poured into the waveguide 16 and the water thus poured can be boiled instantaneously to perform steam cooking in the heating chamber 1. Note that a container (not shown) having an open top made of a ceramic material or resin of a dielectric material that is detachably disposed in the waveguide 16 may be configured and disposed. If the milk bottle b, sake bottle or the like, or a heated liquid or small food is placed or injected into the container, the inside of the waveguide 16 is hardly soiled, no liquid leaks, and the usability is improved. In addition, by arranging the inside of the waveguide 16 on the operation front part of the cooking main body, the cooking operation can be easily performed, the usability is good, and a safe and practical cooking device can be provided.
[0033]
(Example 5)
FIG. 5 is a cross-sectional view of an essential part of a portion provided with a radiation type electric heater installed in part on the top plate of the heating chamber door corresponding to the heating dish.
[0034]
According to FIG. 5, a heater 29 that radiates infrared radiant heat or the like near the inner wall of the top plate of the heating chamber door 5, such as a miraclon heater, a quartz tube heater, or a halogen lamp (an infrared radiation film or the like is attached to the lamp surface). And the like are arranged and mounted via the reflector 30 and the heat insulating material 31.
[0035]
Therefore, the food heater a is effectively distributed on both the upper and lower surfaces when the heater 29 is disposed at a short distance with respect to the food a disposed in the heating dish 11 and the heating dish 11 is heated. Bake well and burnt in a short time, and the internal heating can be quickly boiled by the microwave dielectric heating, so that satisfactory cooking can be achieved. Furthermore, by incorporating automatic control, it is easy to automate, and the development of cooking menus for both Western and Japanese dishes can be greatly expanded, making it possible to create a practical cooking device as a multifunctional cooking device.
[0036]
【The invention's effect】
As is apparent from the above description, according to the present invention, the following effects can be obtained.
[0037]
The present invention provides a radio wave propagation path in a heating chamber having a rectangular cross section and a thin space, and an electromagnetic wave shielding chamber having a built-in heating coil, so that upper and lower cavities are formed above and below a heating plate placed on a partition plate. At the same time, the heating device has become thin due to the electromagnetic shielding room and the power supply port that connects the magnetron installed side by side, making it easy to place on a kitchen table or table, compact and uncomfortable, and easy to use. Next, although the heating chamber is thin, microwave propagation is efficiently radiated, while electromagnetic heating is also added, so that the internal heating and the baking action on the bottom of the food are efficiently and uniformly heated, Rapid heating and rapid baking are possible, and delicious cooking can be realized in a short time.
[0038]
In addition, since the gap between the radio wave propagation path A provided between the outer surface of the heating coil and the inner wall surface of the electromagnetic shielding chamber is set to a minimum of 10 mm or more and 50 mm or less, a high core can be provided without providing a ferrite core below the heating coil. Efficient high-frequency induction heating characteristics can be obtained, and even in the presence of microwaves, the heating coil can be operated simultaneously with high-efficiency high-frequency dielectric and induction heating without thermal damage and characteristic deterioration, expanding the cooking menu and delicious cooking It can be done in a short time.
[0039]
In addition, multiple annular heating plates made of metal material are mounted on either the front or back of the heating pan made of heat-resistant dielectric material, and the center of the heating coil and the center of the heating plate are approximately aligned. By doing so, microwaves can be efficiently reflected and propagated toward the food on the heating pan, and the heating plate has a small heat capacity. Heat cooking became possible.
[0040]
In addition, by increasing the opening area of the power supply port connected to the waveguide, a high-sized container such as a general milk bottle can be easily stored in the space between the bottom surface of the waveguide and the heating chamber, and the waveguide can be guided. The tube portion can be heated in a concentrated and effective manner due to a high microwave electric field, so that heating at a higher speed is possible than in the heating chamber.
[0041]
In addition, by providing a high-temperature radiation type electric heater on a part of the inner wall surface of the top plate of the heating chamber door, the distance between the food placed on the heating dish and the electric heater is reduced, and high-temperature infrared rays are The upper part of the food is heated powerfully and effectively, and the upper surface is baked and cooked uniformly in a short time. Further, by combining with high-frequency induction heating means, it is possible to provide a microwave oven with a high heating power that is more practical than burning the upper and lower surfaces effectively.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a high-frequency heating device showing an embodiment of the present invention. FIG. 2 is a characteristic diagram showing the characteristics of a gap in a radio wave propagation path A and high-frequency induction heating efficiency of the high-frequency heating device. Fig. 4 is a cross-sectional view of a main part showing a portion of a heating plate and a heating plate of the high-frequency heating device. Fig. 4 is a cross-sectional view of a main portion showing a feeding port and a waveguide portion of the high-frequency heating device. Cross-sectional view of the main part in which a radiation-type electric heater is provided on the top plate of the heating chamber door of the apparatus.
DESCRIPTION OF SYMBOLS 1 Heating chamber 2 Machine room 4 Partition plate 5 Heating chamber door 6 Heating coil 8 Electromagnetic wave shielding room A Radio wave propagation path B Radio wave propagation path 11 Heating pan 12 Heating plate 13 Feed port 14 Magnetron 16 Waveguide

Claims (5)

A heating chamber composed of a heating chamber door having a rectangular cross section; a machine chamber provided at a lower portion of the heating chamber; an upper plate made of a metal material that forms a boundary wall between the heating chamber and the machine chamber; and a heat-resistant dielectric material A heating plate made of a heat-resistant dielectric material placed on the partition plate, an annular heating plate made of a metal material attached to the front or back surface of the heating plate, and provided in the machine room An outer periphery of the heating plate having an electromagnetic shielding chamber electrically in contact with the upper plate, a heating coil having a coil hollow portion insulated from the lower surface of the partition plate, an outer surface and a bottom surface of the heating coil, and the electromagnetic shielding. A radio wave propagation path A formed with a certain gap or more between the inner wall surface of the chamber, a magnetron for generating microwaves, a waveguide side by side with the outer peripheral wall of the electromagnetic shielding chamber, before provided in the upper plate High-frequency heating apparatus having an open ended feed port into the heating chamber. The high-frequency heating device according to claim 1, wherein a gap size of the radio wave propagation path A is at least 10 mm and 50 mm or less. The heating plate is composed of a plurality of heating plates arranged concentrically, and one or two or more ring-shaped radio wave propagation paths B are formed in a gap between the heating plate and the heating plate. The high-frequency heating device described. A power supply port provided on an upper plate made of a metal material that forms a boundary wall between the heating chamber and the machine chamber and opened to the heating chamber is provided so as to open at least larger than the external dimensions of a container such as a general 200 ml milk bottle. the container length height region like at least the milk bottle with the top plate of the bottom surface and the heating chamber door before Symbol waveguide mounted in the machine room so as to continuously provided to the feed port so as to be stored The high-frequency heating device according to claim 1, 2 or 3. The high-frequency heating device according to claim 1, 2 or 3, wherein a high-temperature radiation type electric heater is provided on a ceiling inner wall surface of the heating chamber door.

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