JP2008286457A - Microwave heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve an on-target heating distribution of microwave even when a heating body exists around rotary antennas. <P>SOLUTION: Stop positions of the rotary antennas 8, 8 are controlled, the microwave can be easily radiated in a state of stopping the rotary antennas 8, 8 in the direction hardly disturbed by a sheath heater 12 even when the sheath heater 12 exists around the rotary antennas 8, 8, and the heating distribution can be controlled, thus the on-target heating distribution can be achieved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a microwave heating apparatus having a function of heating an object to be heated with a microwave and a function of heating with a heating element.

  A microwave oven, which is a typical microwave heating device, can directly heat food that is a typical object to be heated, so there is no need to prepare a pot or kettle, and it is essential for living. It has become a cooking utensil. In the conventional microwave ovens, the size of the space for storing the food in the heating chamber where microwaves are radiated is generally about 300 to 400 mm in the width direction and the depth direction, and about 200 mm in the height direction. Yes.

  In recent years, a highly convenient product has been put into practical use in which the bottom of the space for storing food is flattened, the width dimension is 400 mm or more, which is relatively larger than the depth dimension, and a plurality of foods can be arranged and heated simultaneously. Has been.

  By the way, the wavelength of the microwave used in the microwave oven is about 120 mm, a strong and weak electric field distribution is generated in the heating chamber, and furthermore, the influence of the shape of the object to be heated and its physical characteristics is synergistically generated to cause uneven heating. It is known. Although it is desirable that the unevenness of heating be as small as possible, particularly in the case of a heating chamber having a large size in the width direction, it is necessary to further increase the uniformity of heating in order to heat foods contained in a plurality of dishes at the same time.

  Conventionally, this type of microwave heating apparatus has been provided with a single radiating antenna and rotationally drives the antenna. However, in recent years, as a measure for improving the uniformity of heating, or with a plurality of radiating antennas, The thing provided with the following high frequency stirring means is proposed (for example, refer patent document 1).

Furthermore, microwave ovens in recent years are mainly microwave ovens that have a function to bake food by separately forming heating elements such as ovens and grills. Especially, an antenna is placed under the heating chamber and a sheathed heater is installed around it. The structure which mounts | wears and heats the bottom face of food is proposed (for example, refer patent document 2).
JP 2004-259646 A JP 2002-349867 A

  In the above-described conventional configuration, the configuration shown in FIG. 21 is particularly shown in Patent Document 2, and a rotating antenna T02 is provided in the lower part of the heating chamber T01, and a sheath heater T03 is provided above the periphery of the rotating antenna. The food placed on the placing table T04 is heated. However, in the case of the configuration of FIG. 21, a part of the microwave radiated from the rotating antenna T02 is reflected because the outer sheath of the sheathed heater T03 is a conductor such as stainless steel, and is near the sheathed heater T03 (that is, outside the mounting table T04). There was a risk that the food placed on the side could not be heated as expected.

  The present invention has been made in view of the above-described conventional circumstances, and an object of the present invention is to realize a microwave heating distribution as intended even when a heating element is present around a rotating antenna.

  The microwave heating apparatus of the present invention includes a heating chamber for storing an object to be heated, a microwave generating means, a waveguide for transmitting microwaves from the microwave generating means, and the waveguide to the heating chamber. A rotating antenna that radiates microwaves, a heating element disposed around the rotating antenna, a driving unit that rotationally drives the rotating antenna, and a control that controls the driving unit to control the stop position of the rotating antenna Means.

  With this configuration, the heating distribution can be controlled by the stop position of the rotating antenna, and the intended heating distribution can be realized even if there is a heating element around the rotating antenna.

  According to the present invention, the heating distribution can be controlled by the stop position of the rotating antenna, and the intended heating distribution can be realized even if there is a heating element around the rotating antenna.

  The microwave heating apparatus of the present invention includes a heating chamber for storing a heated object, microwave generation means, a waveguide for transmitting microwaves from the microwave generation means, and a microwave from the waveguide to the heating chamber. A rotating antenna that radiates a wave, a heating element disposed around the rotating antenna, a driving unit that rotationally drives the rotating antenna, and a control unit that controls the driving unit to control the stop position of the rotating antenna It is set as the structure which has these.

  With this configuration, the heating distribution can be controlled by the stop position of the rotating antenna, and the intended heating distribution can be realized even if there is a heating element around the rotating antenna.

  In addition, as an aspect of the present invention, the microwave heating device described above includes a configuration in which the heating element is disposed at a position lower than the rotating antenna.

  With this configuration, the microwave radiated from the rotating antenna can reach the object to be heated without being disturbed by the heating element.

  In addition, as an aspect of the present invention, in the above microwave heating apparatus, the control unit includes a configuration in which the end portion having a strong directivity of the rotating antenna is stopped at a position higher than the heating element.

  With this configuration, most of the microwaves radiated from the highly directional end of the rotating antenna can reach the object to be heated without being disturbed by the heating element.

  Further, as one aspect of the present invention, in the above microwave heating apparatus, the control unit includes a configuration in which the end portion having a strong directivity of the rotating antenna is stopped in a direction in which the distance to the heating element is far.

  Also with this configuration, most of the microwaves radiated from the highly directional end of the rotating antenna can reach the object to be heated without being disturbed by the heating element.

  In addition, as one aspect of the present invention, in the above microwave heating apparatus, the control unit may include a configuration in which a highly directional end portion of the rotating antenna is stopped toward the feeding portion of the heating element.

With this configuration, the power feeding section of the heating element is configured so that the heating element passes through the wall surface of the heating chamber and feeds power outside the heating chamber, and the distance from the rotating antenna to the heating element inevitably increases, so the directivity of the rotating antenna Most of the microwaves radiated from the strong end can reach the object to be heated without being disturbed by the heating element.

  Further, as one aspect of the present invention, in the above microwave heating apparatus, the microwave heating apparatus includes a heating element holding unit made of a dielectric material attached to the wall surface of the heating chamber in order to regulate the position of the heating element. A configuration in which an end portion having a strong directivity of the antenna is stopped toward the heating element holding means is also included.

  With this configuration, since the heating element holding means is made of a dielectric material, the relative dielectric constant in the microwave band is larger than the relative dielectric constant (= 1) of air and passes through the heating element holding means by the square root of the relative dielectric constant. Since the microwave wavelength is compressed, it has the effect of widening the space, and most microwaves radiated from the highly directional end of the rotating antenna reach the object to be heated without being disturbed by the heating element. Can be made.

  Further, as one aspect of the present invention, in the above microwave heating apparatus, the heating element holding means made of a dielectric material attached to the wall surface of the heating chamber in order to regulate the position of the heating element, the heating element holding means Includes a configuration in which the position of the heating element is regulated in a direction far from the rotating antenna.

  With this configuration, the heating element does not approach the rotating antenna due to variations in mounting of the heating element, and the microwave radiated from the rotating antenna can reach the object to be heated without being obstructed by the heating element.

  In addition, as one aspect of the present invention, in the above microwave heating apparatus, the heating element holding unit includes a configuration in which the position of the heating element is regulated in a direction close to the rotating antenna.

  With this configuration, the heating element does not move too far from the rotating antenna due to the mounting variation of the heating element, and the microwave radiated from the rotating antenna can be prevented from reaching the object to be heated more than intended. .

  Further, as one aspect of the present invention, in the above microwave heating apparatus, a placement table disposed in the heating chamber and on which the object to be heated is placed, and an instruction for instructing a place on the placement table on which the object to be heated is to be placed And a means for indicating the location facing the rotating antenna inside the heating element is also included.

  With this configuration, microwaves can reach the location facing the rotating antenna inside the heating element, so it is possible to raise the user's consciousness by instructing the location where the microwave reaches as the place to place the object to be heated. Since an object to be heated is placed in a region where microwaves can be reliably applied, a desired heating distribution can be realized.

  In addition, as an aspect of the present invention, in the above microwave heating apparatus, the instruction unit includes an instruction unit that indicates a location by marking drawn on a mounting table.

  With this configuration, the user can easily recognize the place to be placed by looking at the marking.

  In addition, as an aspect of the present invention, in the above microwave heating apparatus, the instruction unit includes a configuration in which the location is indicated by a concave portion or a convex portion provided on the mounting table.

  With this configuration, the user can recognize the place to be placed easily by touching the concave portion or the convex portion.

  Furthermore, as one aspect of the present invention, the microwave heating apparatus described above has a lighting unit that illuminates the mounting table, and the instruction unit is configured to indicate a place by illuminating the mounting table with the lighting unit. Is also included.

  With this configuration, the user can easily recognize the place to be placed by looking at the illuminated place.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
1 to 7 show the microwave heating apparatus according to the first embodiment. 1 and 2 are diagrams showing a schematic configuration of a microwave oven that is a microwave heating apparatus of Embodiment 1, FIG. 1 is a plan sectional view seen from above, and FIG. 2 is a front sectional view seen from the front. It is.

  In FIG. 1, the microwave oven according to the present embodiment is connected to a magnetron 1 that is a typical microwave generation means, a waveguide 2 that propagates microwaves emitted from the magnetron 1, and an upper portion of the waveguide 2. The heating chamber 3, the mounting table 5 on which the food 4 that is a typical object to be heated is mounted, the antenna space 6 formed below the mounting table 5, and the heating chamber 3 are fitted with two coupling holes 7 and 7 provided on the bottom surface at an approximately equal distance from the center of 3 and rotating antennas 8 and 8 disposed in the antenna space 6 and rotatable about the coupling holes 7 and 7. The motors 9 and 9 as driving means for driving the rotating antennas 8 and 8 via the drive shaft and the control means 10 for controlling the rotation and stop of the motors 9 and 9 are provided.

  Moreover, the microwave oven of this embodiment is provided with the setting means 11, and a user can select a cooking menu according to food or cooking content. Based on the selection result, the control means 10 controls the magnetron 1 to generate and stop the microwave, and also controls the motor 9 to control the rotation and stop of the rotating antennas 8 and 8. Thereby, the food 4 mounted on the mounting table 5 can be heated and cooked.

  The rotating antenna 8 is a substantially L-shaped patch antenna, and is electrically connected to the radiating portion 81 through the coupling hole 7 and the radiating portion 81 made of a flat plate-like conductive material having a longitudinal direction along the L shape. And a coupling portion 82 made of a cylindrical conductive material integrated mechanically.

  FIG. 3 is a plan view illustrating a specific shape of the radiating portion 81.

  In FIG. 3, the length from the center of the coupling portion 82 of the radiating portion 81 to the end portion 84 in the longitudinal direction of the long side 81a along the L-shape is 50 mm. On the other hand, along an alternate long and short dash line (hereinafter referred to as a reference line) having a long side width of 30 mm, it bends in an L shape at an angle of 83.62 ° at a position of 35 mm from the center of the coupling portion 82, The creeping surface of the end portion 83 of the short side 81b along the L-shape of the radiating portion 81 at a distance of 45 mm is configured to form a part of an arc having a radius of 60 mm with the coupling portion 82 as the center.

  When the overall shape of the radiating portion 81 in plan view is grasped as an L shape, the long side 81a is defined as a first portion coupled to the coupling portion 82, while the short side 81b is defined as the first portion. Defined as the intersected second part. In addition, as described above, the length in the longitudinal direction of each part (the first part and the second part) of the radiating part is the length of the reference line indicated by the alternate long and short dash line located at the center in the width direction of the radiating part. It can be defined by the length of the direction.

  According to this shape, the rotation diameter of the radiating portion 81 centered on the coupling portion 82 is 120 mm, which corresponds to the wavelength of the microwave (one wavelength), and the diameter when the antenna rotates from the width of the heating chamber 4. Is a dimension that can be used even when is limited to one wavelength or less of the microwave.

  In other words, in the present embodiment, the radiating portion 81 has two portions that intersect each other, ie, the first portion (long side 81a) and the second portion (short side 81b), and thus is restricted by the rotation diameter. Even in a narrow space, a substantially larger length (a length along the reference line) than the simple rotation diameter or rotation radius is secured. Specifically, in FIG. 3, the radius of rotation is 60 mm, but the substantial length of the radiating portion corresponding to the radius is 35 + 45 mm = 80 mm. Therefore, it is considered that microwaves with strong directivity can be emitted even in a narrow space.

  However, since the radiating portion 81 is L-shaped, the direction having the strongest directivity of the radiating portion as a whole is slightly bent from the longitudinal direction and becomes a direction like a solid arrow line 85. The direction with the next highest directivity is a broken line 86. Therefore, the end portions with strong directivity in the rotating antenna of this embodiment can be referred to as end portions 851 and 861.

  Next, the sheathed heater 12 that is a typical heating element will be described. 1 and 2, the sheathed heater 12 includes a power feeding unit 12 a that is disposed outside the heating chamber and is supplied with power, and a heat generating unit 12 b in the heating chamber. The heat generating unit 12 b is a driving region 13 of the rotating antenna 8. Is disposed at a position lower than the radiating portion 81 of the rotating antenna 8 by K (about 5 mm), and is bent at the four corners of the heating chamber 3 by the corner portions 12c, 12d, 12e, and 12f. Since the sheathed heater is a heater for baking food on the mounting table, it is arranged at a position where there is as little baking unevenness as possible based on experimental results.

  Next, FIG. 4 shows a configuration of an insulator 14 which is a typical heating element holding means. FIG. 4 is a view of the right insulator 14 in FIG. 1 as viewed from the front. The insulator 14 is made of a dielectric material and holds the heat generating portion 12b of the sheathed heater 12. However, in order to regulate the position of the heat generating portion 12b. Are provided with restricting portions 14a, 14b, 14c, and 14d. The restricting part 14a restricts the heat generating part 12b from falling down, the restricting part 14b restricts the heat generating part 12b from going to the left (not close to the rotating antenna), and the restricting part 14c is the heat generating part. 12b is restricted so that it does not go up (closer to the food side than the radiating part), the restricting part 14d is restricted so that the heating part 12b does not go to the right, and the insulator 14 is the bottom of the heating chamber. It is fixed to 301 with screws 15.

  FIG. 5 is a diagram for explaining the stop position of the rotating antenna together with FIG.

  First of all, there is no particular problem when the direction in which the rotating antenna has high directivity (the solid arrow 85 in FIG. 1) faces away from the heating element. For example, as shown in FIG. 1, the strong directivity direction 85 of the left rotating antenna faces the right side, or the strong directivity direction 85 of the right rotating antenna faces the left side.

Next, when the direction of the rotating antenna having a strong directivity (the solid arrow 85) is directed toward the heating element (that is, the direction of the left rotating antenna having the strong directivity is directed to the left or the right rotating antenna If the direction of strong directivity is to the right), the conductor part of the heating element (the entire exterior of the sheathed heater in the present embodiment) becomes an obstacle, and the ease of radiating microwaves depends on the distance to the heating element. Will change. However, in this embodiment, since the control means can control the stop position of the rotating antennas 8 and 8, the rotating antennas 8 and 8 are stopped in a direction in which the distance to the heating element becomes longer. In the case of FIG. 1 and FIG. 5, the left rotating antenna has a long distance to the corner portion 12c as apparent from the drive region 13, so that the direction with strong directivity becomes the solid arrow line 85a. The unit 851 is stopped. Similarly, in the case of the right rotating antenna, since the distance to the corner portions 12e and 12f is long, the end portion 851 is stopped in such a direction that the direction having strong directivity becomes the solid arrow line 85b or the solid arrow line 85c.

  In the case of the right rotating antenna, there is a space 16 where there is no heating element due to the feeding portion 12a, and here the heating element does not get in the way, so the direction with strong directivity is the solid arrow line 85d. The end portion 851 is also stopped in the orientation.

  Further, the left rotating antenna is stopped even when the direction of strong directivity is the solid arrow 85e, and the right rotating antenna is stopped even when the direction of strong directivity is the solid arrow 85f. This is the direction of the insulator 14, but the insulator 14 is made of a dielectric material, and the relative permittivity in the microwave band is larger than the relative permittivity of air (= 1). The relative dielectric constant of dielectric materials that can be used in a microwave oven, such as ceramic, glass, resin, etc., is 10 or less, especially about 2 to 4. In addition, it is known that when the relative dielectric constant is ε, the wavelength of the microwave passing through the region is compressed to 1 / √ε, and conversely, the size of the region has increased by √ε times. Will be the same. For example, when the relative dielectric constant ε = 4 of the insulator 14, the region where the insulator 14 is present is twice as large as the actual size, and as a result, the distance to the heating element is longer than the surrounding area. .

  FIG. 6 is a view of the mounting table 5 as viewed from above. For the sake of clarity, the drive areas 13 and 13 of the rotating antennas 8 and 8 and the drive area 17 of the heat generating part 12b that are not actually visible are indicated by broken lines. The mounting table 5 is configured such that white markings 19a, 19b, 19c, 19d on a dark background color 18 as a representative instruction means for placing food. In particular, the markings 19a and 19b indicate the locations facing the rotating antennas 8 and 8 inside the heat generating portion 12b, as is clear from the drive regions 13 and 17, and the markings 19c and 19d indicate the rotating antenna 8. , 8 are indicated.

  As described above, in the present embodiment, the stop positions of the rotating antennas 8 and 8 are controlled. Therefore, even if the sheathed heaters 12 are around the rotating antennas 8 and 8, the rotating antennas 8 and 8 can be stopped and the microwaves can be easily emitted, and the heating distribution can be controlled, so that the intended heating distribution can be realized.

  In particular, by arranging the sheathed heater 12 at a position lower than the rotating antennas 8 and 8, the microwaves radiated from the rotating antennas 8 and 8 can reach the food 4 without being disturbed by the sheathed heater 12.

  Further, the control means 10 is configured to stop the end portions 851 having strong directivity of the rotating antennas 8 and 8 in a direction in which the distance to the sheathed heater 12 is far (solid arrow lines 85a, 85b, and 85c), Most of the microwaves radiated from the end portion 851 having strong directivity of 8 can reach the food 4 without being disturbed by the sheathed heater 12.

  Further, the control means 10 is configured to stop the end portion 851 having strong directivity of the rotating antennas 8 and 8 toward the power supply portion 12a of the sheathed heater 12, so that the power supply portion 12a of the sheathed heater 12 is heated by the sheathed heater 12 in the heating chamber. Since power is supplied outside the heating chamber 3 through the wall surface, and the distance from the rotating antennas 8 and 8 to the sheathed heater 12 is inevitably increased, radiation from the end portion 851 having strong directivity of the rotating antennas 8 and 8 is radiated. Most of the microwaves that are generated can reach the food 4 without being disturbed by the sheathed heater 12.

In addition, in order to regulate the position of the sheathed heater 12, it has a insulator 14 made of a dielectric material attached to the bottom surface 301 of the heating chamber, and the control means 10 provides a strong directivity end 851 of the rotary antennas 8, 8. 14 is made of a dielectric material, so that the dielectric constant in the microwave band is larger than the relative dielectric constant (= 1) of air, and passes through the insulator 14 by the square root of the dielectric constant. Since the wavelength of the microwave is compressed, there is an effect as if the space is widened. Can reach the object to be heated.

  In addition, in order to regulate the position of the sheathed heater 12, it has a insulator 14 made of a dielectric material attached to the heating chamber wall surface, and the insulator 14 restricts the position of the sheathed heater 12 in a direction far from the rotary antennas 8, 8. Due to the configuration, the sheathed heater 12 does not approach the rotating antennas 8 and 8 due to variations in the mounting of the sheathed heater 12, and the microwaves radiated from the rotating antennas 8 and 8 are not disturbed by the sheathed heater 12 and are fed to the food 4. Can be reached.

  Further, the insulator 14 includes a configuration in which the position of the sheathed heater 12 is restricted in a direction close to the rotary antennas 8 and 8.

  With this configuration, the sheathed heater 12 does not move too far from the rotating antennas 8 and 8 due to variations in the mounting of the sheathed heater 12, and the microwaves radiated from the rotating antennas 8 and 8 reach the food 4 more than intended. Can be prevented.

  In addition, it has markings 19 a, 19 b, 19 c, and 19 d as instruction means for instructing where to place the food 4 on the mounting table 5 placed in the heating chamber and on which the object to be heated is placed. 19a and 19b indicate the location facing the rotating antennas 8 and 8 inside the sheathed heater 12, so that microwaves can reach the location facing the rotating antennas 8 and 8 inside the sheathed heater 12, so that the microwaves By instructing the place where the food arrives as the place where the food 4 should be placed, the user's awareness can be raised and the food 4 can be placed in an area where microwaves can be reliably applied. Can be realized.

  Further, according to the present embodiment, as the instruction means, the location is indicated by the difference in the color of the marking drawn on the mounting table 5, so that the user can easily place it by seeing the difference in the color of the marking. Recognize where to be. As a result, it is difficult to place at least the end that is off the marking, so that the probability that the microwave will fail without reaching by being placed at a position that covers the sheathed heater 12 at the end can be significantly reduced. The desired heating distribution can be realized.

  The marking may not be a difference in color, but may be the same color shade or dot density, as long as it is an instruction means that can be visually recognized.

  In addition, according to this embodiment, since the intermediate area of the place where the plurality of rotating antennas 8 and 8 are opposed is indicated by the markings 19c and 19d, the intermediate area can be irradiated with microwaves equally from the plurality of rotating antennas 8 and 8, By combining the microwaves, it becomes a place that can be heated more than other regions. In addition, when only one food item is placed, it is difficult to determine where to place the markings 19a and 19b alone. However, if there is the markings 19c and 19d, it may be placed naturally between the markings 19c and 19d. Consciousness works and becomes easy to put. Further, when two foods are placed, the markings 19a and 19b are arranged symmetrically, so that the consciousness that they should be placed there works and it is easy to place them. Furthermore, when three foods are placed, one is placed on each of the markings 19a and 19b and one is placed between the markings 19c and 19d. It is difficult to fail because it prevents the consciousness of this.

  FIG. 7 is a plan view showing a modified example of the radiating portion of the rotating antenna. FIG. 7A shows a short side formed in a sickle shape, thereby increasing the creeping length of the short side end, The directivity of the microwave radiated from the tip side is strengthened. Further, (b) forms a short side along the T-shape, thereby further increasing the creeping length of the short side end portion and strengthening the directivity of the microwave radiated from the end tip side. . (C) By increasing the creeping length of the end of the short side and narrowing the width of the short side to concentrate the electric field of the microwave by forming the short side in a pickle shape, the radiation directivity is improved. It is what. In any case, the direction having the strongest directivity as the whole radiation portion is a solid arrow 85, and the direction having the next strong directivity is a broken line 86.

  Further, according to the present embodiment, the rotary antenna is configured in two examples, but of course, the present invention is not limited to this, and there may be one or three or more.

(Embodiment 2)
8 to 12 show the second embodiment. FIG. 8: is a figure which shows schematic structure of the microwave oven which is a microwave heating device of Embodiment 2 which concerns on this invention, and is the plane sectional view seen from the upper part.

  The microwave oven according to the present embodiment includes a magnetron 20 that is a typical microwave generation unit, a waveguide 21 that propagates microwaves emitted from the magnetron 20, and a heating that is connected to the top of the waveguide 21. The rotating antenna 23 is provided approximately equidistant from the center of the heating chamber bottom 221, which forms the chamber 22 and the bottom of the heating chamber 22.

  The rotary antenna 23 is a so-called slot antenna, and has a radiating portion 25 having a slot (hole) 24 in a flat disk-shaped conductive material, and a cylindrical shape that is electrically and mechanically integrated with the radiating portion 25. The coupling portion 26 is made of a conductive material. The rotating antenna 23 of the present embodiment has a characteristic that the radiation directivity increases from the coupling portion 26 to the end portion 27 on the slot (hole) 24 side, that is, in the direction of the solid arrow line 28.

  The heating element and the heating element holding means will be described with reference to FIGS. 9 is a cross-sectional view seen from the solid arrow lines 29 and 29 of FIG. 8, and FIG. 10 is a cross-sectional view seen from the solid arrow lines 30 and 30 of FIG.

  The sheathed heater 31 includes a power feeding unit 311 that is disposed outside the heating chamber and is supplied with power, and a heat generating unit 312 in the heating chamber, and the heat generating unit 312 is a drive region 32 of the rotating antenna 23 (the radiation unit 25 is circular). Most of them are positioned higher than the radiation part 25 of the rotating antenna 23 by L, but only the two low parts 313 formed by bending the heat generating part 312 are more than the radiation part 25. It is lowered by M (about 5 mm).

  Next, the insulator 33 which is a heating element holding means will be described. The insulator 33 is made of a dielectric material and holds the heat generating portion 312 of the sheathed heater 31, and has restricting portions 34 a and 34 b for restricting the position of the heat generating portion 312. The restricting part 34a restricts the heat generating part 312 from falling down, the restricting part 34b restricts the heat generating part 312 so as not to approach the rotating antenna 23 side, and the insulator 33 is provided on the bottom of the heating chamber. 221 is fixed with screws 35.

Next, stop position control of the rotating antenna 23 will be described. In the present embodiment, the heating chamber 22 has a horizontally long rectangular shape as shown in FIG. 8, and it is difficult to radiate microwaves evenly in the cabinet simply by rotating the rotating antenna 23 at a constant rate. That is, microwaves are easy to reach in front of and behind the heating chamber 22 (bottom and top in FIG. 8) because the distance from the rotating antenna 23 is short, but on the right and left of the heating chamber 22 (right and left in FIG. 8) Since the distance from the rotating antenna 23 is long, microwaves are difficult to reach. Therefore, in the present embodiment, the lower portion 313 is provided in the heat generating portion 312 of the sheathed heater 31 only on the right and left, and the height is made lower than the end portion 27 of the radiating portion 25 so as not to interfere with the microwave. In the state where the end 27 of the rotating antenna 23 faces right (the direction shown in FIGS. 8 and 9) and leftward (not shown) by the control means (not shown), it is longer than the other directions. Control is performed to stop for a time.

  FIG. 11 is a cross-sectional view of the main part of the side wall surface of the heating chamber 22, and an illuminating means 36 made of an LED or the like that irradiates light is rotatably provided in the heating chamber 22.

  In addition, the illumination means 36 is provided with a triangular prism-shaped protrusion 223 projecting into the heating chamber 22 on the upper side wall surface 222 on the right side of the heating chamber 22, and provided inside the protrusion 223. A window 224 is notched on the lower surface of the protrusion 223 so that light from the illumination means 36 is projected into the heating chamber 22. The illumination means 36 can be swung by a swing mechanism 37.

  FIG. 12 is a view of the mounting table 38 from above, and the driving area 32 of the rotating antenna 23 that is not actually visible is shown by broken lines for easy understanding. The mounting table 38 is illuminated by the illumination means 36, and the spot points 39 illuminated as the illumination means 36 swings the head by the head swing mechanism 37 are sequentially changed in position as indicated by a solid arrow line 40. It indicates the area where food should be placed. That is, the spot point 39 is a typical instruction means.

  As described above, in the present embodiment, the rotating antenna 23 has a configuration in which the highly directional end portion 27 is directed toward the low portion 313 of the sheathed heater 31 and the end portion 27 is stopped at a position higher than the low portion 313. Most of the microwaves radiated from the end portion 27 having strong directivity 23 can reach the food without being obstructed by the low portion 313.

  Further, according to the present embodiment, when the heating distribution is controlled by the direction of the rotating antenna 23, the spot point 39 indicates the place where the food should be placed. Therefore, the place where the food should be placed can be clarified and the microwave can be reliably applied. It is possible to raise the user's consciousness so that food can be placed only in the area where it can. As a result, it is difficult to place at least the four corners off the spot point, so the probability of failure due to being placed at the four corners can be greatly reduced, and the intended heating distribution can be realized.

  In addition, according to the present embodiment, as the instruction unit, the illumination unit 36 that illuminates the mounting table 38 is provided, and the instruction unit indicates a location by a spot point 39 generated by illuminating the mounting table 38 by the illumination unit 36. Therefore, the user can easily recognize the place to be placed by looking at the illuminated spot point 39.

  In addition, when instruct | indicating by the spot point 39 like this Embodiment, it is also possible to change the place illuminated according to the objective depending on the control method of the swing mechanism 37. For example, if the number of foods can be set, when it is set to 1, it will be illuminated like drawing a circle in the middle area, and when it is set as 2 it will be illuminated like drawing two circles, etc. It is also possible to control. It may be changed depending on the setting contents and menu.

  Further, in the present embodiment, the small spot points 39 are sequentially moved, but it may be configured to illuminate a large area that can cover the whole at once. In this case, the swing mechanism can be eliminated.

(Embodiment 3)
13 to 20 show the third embodiment. 13 and 14 are configuration diagrams of a microwave oven 41 that is a typical microwave heating apparatus according to the present invention. FIG. 13 is a plan sectional view seen from above, and FIG. 14 is seen from a solid arrow line 42 in FIG. FIG.

  As shown in FIG. 13, the microwave oven 41 includes a waveguide 44 that transmits a microwave radiated from a magnetron 43 that is a typical microwave generation unit, and a width dimension that is connected to an upper portion of the waveguide 44. (About 410 mm) is fixed in the heating chamber 45 for placing a heating chamber 45 having a shape larger than the dimension in the depth direction (about 315 mm) and food (not shown) which is a typical object to be heated. Since it is made of a low-loss dielectric material such as glass, a mounting table 46 that can easily transmit microwaves, an antenna space 47 formed below the mounting table 46 in the heating chamber 45, and the waveguide 44 In order to radiate microwaves into the heating chamber 45, two rotating antennas 48 and 49 that are mounted symmetrically with respect to the width direction of the heating chamber 45 from the waveguide 44 to the antenna space 47, Motors 50 and 51 as typical driving means capable of rotating the antennas 48 and 49, control means 52 for controlling the motors 50 and 51 to control the orientation of the rotating antennas 48 and 49, and the respective rotating antennas 48 and 49 A photo interrupter 53 that constitutes an origin detection mechanism for detecting the origin of rotation, and an infrared sensor 54 that is a temperature distribution detection means for detecting the temperature distribution in the heating chamber 45.

  The microwave oven 41 is provided with a door 55. A setting means (not shown) is disposed below the door 55. The setting means (not shown) allows the user to select various cooking menus according to food and cooking contents. Based on the selection result, the control means 52 can control the magnetron 43 and the motors 50 and 51.

  The rotary antennas 48 and 49 have a radiation directivity. The microwave oven 41 of the present embodiment is configured to centrally heat a specific food by controlling at least one of the rotating antennas 48 and 49 with a high radiation directivity in a predetermined direction. The specific control method will be described later.

  The rotating antennas 48 and 49 are electrically conductive in a substantially cylindrical shape with a diameter of about 18 mm that passes through the coupling holes 56 and 57 with a diameter of about 30 mm provided on the boundary surface between the waveguide 44 and the heating chamber wall surface 451. The coupling portions 58 and 59 made of a conductive material are integrated with the upper ends of the coupling portions 58 and 59 by caulking, welding, or the like, and are made of a conductive material having a larger area in the horizontal direction than in the vertical direction. The radiation | emission part 60 and 61 which consist.

  The rotating antennas 48 and 49 are configured to be fitted to the shafts 62 and 63 of the motors 50 and 51 so that the centers of the coupling portions 58 and 59 are the centers of rotation driving. The radiation parts 60 and 61 are configured to have radiation directivity because the shape is not constant with respect to the direction of rotation.

  The centers of rotation of the rotating antennas 48 and 49 are arranged at an approximately equal distance from the center in the heating chamber 45. With this configuration, heating can be performed by directing the end portions 60a and 61a having strong radiation directivity of the rotating antennas 48 and 49 toward the center in the vicinity of the center of the heating chamber, which is normally difficult to heat with a single antenna configuration. It is.

  The waveguide 44 has a T-shape when viewed from above as shown in FIG. 13 and has a symmetrical shape, so that the distance from the magnetron 43 to the coupling portions 58 and 59 is equal, and the coupling portions 58 and 59 are the same. Is attached at a symmetrical position with respect to the width direction of the heating chamber 45, so that the microwaves radiated from the magnetron 43 are almost uniformly distributed in the heating chamber 45 through the waveguide 44 and the rotating antennas 48 and 49. Distributed.

The radiating portions 60 and 61 have the same shape, and the radiating portion upper surfaces 64 and 65 have a substantially quadrangular shape, of which three sides have a radiating portion bending portion 66 bent toward the heating chamber wall surface 451 side. It is the structure which restrict | limits the radiation of the microwave to the outer side. The distance between the heating chamber wall surface 451 and the radiating portion upper surfaces 64 and 65 is about 10 mm, and the radiating portion bending portion 66 is pulled down to a position lower by about 5 mm. Further, the width of the remaining edge portions 60a and 61a is set to 80 mm or more. In this configuration, the rotating antennas 48 and 49 are so-called rotating waveguide type antennas, and the radiation directivity from the coupling portions 58 and 59 to the end portions 60a and 61a can be enhanced.

  In the case of heating a general food uniformly in this configuration, it is not necessary to pay particular attention to the place where the food is placed, as in a conventional microwave oven, and the rotating antennas 48 and 49 may be rotated at a constant speed as in the conventional case. On the other hand, when the central heating is performed, particularly when the vicinity of the center in the heating chamber 45 is heated, the control means 52, as shown in FIGS. 13 and 14, the end portions 60a and 61a of the rotating antennas 48 and 49 are The heating chamber 45 is controlled so as to be directed in a predetermined direction, ie, approximately the center in the width direction and approximately the center in the depth direction.

  When the end portions 60a and 61a of the rotating antennas 48 and 49 are directed to the approximate center in the width direction of the heating chamber 45 and the approximate center in the depth direction, the radiation directivity in the direction of the end portions 60a and 61a is strong. Microwaves are radiated from the direction of 60a and 61a, and the food located in that direction can be heated intensively.

  Further, when the vicinity of the left side in the heating chamber 45 is heated, the control unit 52 directs the end portions 60a and 61a of the rotating antennas 48 and 49 to the left (left side when the heating chamber 45 is viewed from the door 55 side). Control is sufficient.

  Similarly, when the vicinity of the right side in the heating chamber 45 is heated, the control means 52 directs the end portions 60a and 61a of the rotating antennas 48 and 49 to the right (right side when the heating chamber 45 is viewed from the door 55 side). It may be controlled to.

  In addition, when the vicinity of the front center in the heating chamber 45 is heated, the control means 52 connects the end portions 60a and 61a of the rotating antennas 48 and 49 to the front of the heating chamber 45 in the center in the width direction and in the depth direction (heating chamber). It may be controlled so that it is directed to the vicinity of the center front in 45).

  When the vicinity of the rear center in the heating chamber 45 is heated, the control means 52 moves the end portions 60a and 61a of the rotating antennas 48 and 49 to the rear of the heating chamber 45 in the center in the width direction and in the depth direction (heating chamber It may be controlled so as to be directed toward the vicinity of the center rear in 45).

  As described above, the microwave oven 41 according to the present embodiment controls the direction of the rotating antenna in accordance with a place where it is desired to locally heat. In order to orient the rotating antennas 48 and 49 in a predetermined direction, a stepping motor is used as the motors 50 and 51, or even if the motor rotates at a constant rotation, the reference position is detected and the energization time is controlled. Conceivable.

  In the microwave oven 41 of the present embodiment, stepping motors are used as the motors 50 and 51, and origin detection mechanisms are provided on the shafts 62 and 63 of the motors, respectively. As shown in FIG. 15, the origin detection mechanism includes a disc 62 a having a shaft as a center axis and a photo interrupter 53. The disc 62a is provided with a rectangular slit 62b.

  The disc 62a is commonly attached to the shafts of the motor shafts 62 and 63 for rotating the rotating antennas 48 and 49, and rotates so as to block the optical path of the photo interrupter 53 including the light emitting element and the light receiving element. Is.

  With this configuration, when the slit 62b passes through the optical path of the photo interrupter 53, since there is nothing to block the optical path, it is possible to detect the passage time of the slit. Therefore, by setting the position of the slit 62b as the origin of the rotating antennas 48 and 49, the origin of the rotating antenna can be detected by the photo interrupter 53 attached to each motor.

  Further, the control means 52 uses the origin that can be detected by the origin detection mechanism as a reference, and determines the angle (stop position) of the rotating antennas 48 and 49 when the highly directional portions of the rotating antennas 48 and 49 are concentrated on the local heating location. An antenna angle storage unit is stored in advance. When local heating is performed by controlling the operations of the rotating antennas 48 and 49, information in the antenna angle storage unit is referred to.

  In addition, although the case where the number of rotating antennas was two was demonstrated so far, the number of rotating antennas is not restricted to this, Two or more may be sufficient, for example, it is good also as a structure which has three rotating antennas.

  Next, with reference to FIG. 16, the infrared sensor 54 which is a temperature distribution detection means with which the microwave oven 41 of this Embodiment is provided is demonstrated. The infrared sensor 54 includes a plurality of infrared detection elements 71 arranged in a line on the substrate 70, a case 72 that accommodates the entire substrate 70, and the case 72 perpendicular to the direction in which the infrared detection elements 71 are aligned. And a stepping motor 73 that moves in the intersecting direction.

  On the substrate 70, a metal can 74 enclosing the infrared detection element 71 and an electronic circuit 75 for processing the operation of the infrared detection element 71 are provided. The can 74 is provided with a lens 76 through which infrared rays pass. In addition, the case 72 is provided with an infrared passage hole 77 through which infrared light passes and a hole 78 through which a lead wire from the electronic circuit 75 passes.

  With this configuration, when the stepping motor 73 rotates, the case 72 can be moved in a direction perpendicular to the direction in which the infrared detection elements 71 are aligned.

  FIG. 17 is a diagram illustrating an infrared temperature detection spot. As shown in the figure, the microwave oven 41 of the present embodiment can detect the temperature distribution in almost all regions in the heating chamber 45 when the stepping motor 73 of the infrared sensor 54 reciprocates. It is.

  Specifically, for example, first, the infrared detection elements 71 arranged in a line of the infrared sensor 54 simultaneously detect the temperature distribution in the areas A1 to A4 in FIG. Next, when the stepping motor 73 rotates and the case 72 moves, the infrared detection element 71 detects the temperature distribution in the region of B1 to B4. Further, when the stepping motor 73 rotates and the case 72 moves, the infrared detection element 71 detects the temperature distribution in the region C1 to C4, and similarly detects the temperature distribution in the region D1 to D4.

  Further, following the above-described operation, the stepping motor 73 reversely rotates, so that the temperature distribution is detected in the order of C1 to C4, B1 to B4, and A1 to A4 from the region side of D1 to D4. The infrared sensor 54 can detect the entire temperature distribution in the heating chamber 45 by repeating the above operation.

Next, a schematic configuration of the control unit 52 will be described with reference to FIG. The control means 52 includes an antenna control unit 521 that controls the operation of the rotating antennas 48 and 49, a food determination unit 522 that determines whether the object to be heated placed in the heating chamber 45 is food, It is the structure which has the heating initial stage completion | finish determination part 523 which determines completion | finish of an initial stage among processes, and the heating completion determination part 524 which determines completion | finish of the whole heat processing.

  The food determination unit 522 includes an initial temperature distribution storage unit 528 that stores an initial temperature distribution of the object to be heated, and a temperature increase rate calculation unit 529 that calculates a temperature increase rate per unit time of the object to be heated. When the calculated temperature increase rate is equal to or higher than a predetermined value, it is determined that the object to be heated is food. In other words, this is to determine whether the region where the temperature is detected is a mounting table on which an object to be heated is placed or a food to be heated. The mounting table transmits microwaves and hardly rises in temperature. However, foods tend to rise in temperature due to absorption of microwaves, and are distinguished by their characteristic differences.

  The heating initial stage end determination unit 523 performs heating when, for example, a determination condition for determining that the heating initial stage has ended when a predetermined time has elapsed from the start of heating, or when the maximum temperature of the object to be heated reaches a predetermined temperature or more. The heat treatment is performed using the determination condition for determining that the initial stage has been completed, and the determination condition for determining that the initial stage of heating has been completed when the maximum value of the temperature change of the heated object from the start of heating is equal to or greater than a predetermined value. It is determined that the initial stage has been completed.

  The heating end determination unit 524 determines, for example, a determination condition for determining that the heating process is to be ended when the maximum temperature in the temperature distribution of the object to be heated exceeds a preset set temperature, or the average temperature of the portion determined to be food. Measure conditions for ending the heat treatment when the set temperature is exceeded, and the time required for the maximum temperature of the object to be heated to reach a predetermined temperature, and measuring a certain percentage of the required time (for example, 50% ) As an additional heating time, and then the end of the heating process is determined by a configuration that ends the heating process when the additional heating time ends.

  The antenna controller 521 controls the operation of the rotating antennas 48 and 49 to uniformly heat the heating chamber, and controls the operation of the rotating antennas 48 and 49 to heat the low-temperature portion of the object to be heated. A local heating (spot heating) mode control unit 526, and a low temperature part extraction unit 527 that detects a low temperature part of an object to be heated placed in the heating chamber.

  For example, the distributed heating mode control unit 525 performs distributed heating by changing the stop positions of the two rotating antennas 48 and 49 capable of local heating by stopping at a predetermined position during microwave oscillation. In this configuration, distributed heating is realized by continuously rotating the rotating antennas 58 and 59, and distributed heating is realized by randomly changing the stop positions of the rotating antennas 48 and 49.

  The local heating (spot heating) mode control unit 526 is configured to obtain information on the lowest temperature location from the low temperature part extraction unit 527 and control the direction of the rotating antennas 48 and 49 to perform local heating. For example, if the lowest temperature point is any one of B2, B3, C2, and C3 in FIG. 17, the rotating antennas 48 and 49 rotate in the direction in which the center is heated, that is, the stop position shown in FIGS. The antennas 48 and 49 are stopped.

  Moreover, if the lowest temperature location is either B1 or C1 in FIG. 17, the rotating antennas 48 and 49 are stopped in a direction in which the rotating antennas 48 and 49 heat the left direction. Moreover, if the lowest temperature location is either B4 or C4 in FIG. 17, the rotating antennas 48 and 49 are stopped in a direction in which the rotating antennas 48 and 49 heat the right direction.

Moreover, if the lowest temperature location is either A2 or A3 in FIG. 17, the rotating antennas 48 and 49 are stopped in a direction in which the rotating antennas 48 and 49 heat the front. Moreover, if the minimum temperature location is either D2 or D3 in FIG. 17, the rotating antennas 48 and 49 are stopped in a direction in which the rotating antennas 48 and 49 heat the rear.

  As described above, the control means 52 controls the stop position of the rotating antennas 48 and 49 according to the lowest temperature location detected by the temperature detecting means. At this time, the rotating antenna stops at a predetermined position. If microwaves are continuously radiated into the heating chamber, the rotating antenna itself may be heated too much and melt.

  In view of this point, the local heating (spot heating) mode control unit 526 of the control unit 52 causes the rotating antennas 48 and 49 to have a predetermined angle (for example, ±) around the target angle (stop position) in the local heating mode described above. 5 degrees). Thereby, deterioration of the rotating antenna can be prevented without affecting the local heating effect. In addition, since the rotating antenna continues to stop during the microwave radiation, the microwave is prevented from being excessively concentrated on a part of the rotating antenna to prevent overheating. Although this reciprocating rocking | fluctuation operation may be performed from the time of a local heating start, it is good also as a structure which starts after predetermined time progress (for example, 30 seconds-1 minute later) from the time of a local heating start.

  In order to perform this reciprocating swinging operation, the control means 52 includes a stop upper limit time storage unit that stores in advance an upper limit time that allows the rotation antennas 48 and 49 to stop, and the rotation antennas 48 and 49 stop. And a reciprocal angle storage unit for storing an angle at which the rotary antennas 48 and 49 are reciprocally swung.

  Alternatively, the rotating antennas 48 and 49 may be rotated by a predetermined angle (for example, 5 degrees) after a predetermined time has elapsed from the start of local heating (for example, 30 seconds to 1 minute).

  The control means 52 stores the origin when the rotary antennas 48 and 49 are at a predetermined stop position (angle). And the control means 52 performs the origin detection mode which confirms the origin of the rotating antennas 48 and 49 before heat processing execution or after heat processing execution, for example.

  During the origin detection mode, the angles of the rotating antennas 48 and 49 cannot be specified, and if the microwaves are oscillated as they are, an unintentional heating state may be caused and a defect may be caused. Therefore, the control means 52 performs control to stop the operation of the magnetron while driving the rotating antenna in the origin detection mode.

  The control means 52 performs the origin detection mode after the end of the heating process, and waits for non-heating with the origin detected. Thereby, it is possible to prevent the standby time for detecting the origin from occurring before starting the heat treatment.

  In addition, when the origin is not found in the origin detection mode, the control unit 52 determines that the error has occurred and performs the heating in a state where the rotation antennas 48 and 49 are stopped and the menu for prohibiting the subsequent heating process from being executed. And a menu for executing processing. With this configuration, according to the cooking menu, for example, in the case of a menu where the temperature distribution in the heating chamber 45 may be biased (for example, if there is unevenness as long as the heat treatment can be performed), the rotating antennas 48 and 49 Since the heat treatment is executed while the operation is stopped, a minimum function can be provided to the user.

  If the origin cannot be detected, the motors 50 and 51 that drive the rotating antennas 48 and 49 may be out of order, and there is a problem in operating the rotating antennas 48 and 49 in that state. The operations of the antennas 48 and 49 are stopped.

  On the other hand, when the temperature distribution in the heating chamber 45 is biased and the menu does not allow the user to achieve the desired heat treatment, the execution of the heat treatment itself is prohibited.

  Further, the control means 52 is configured to uniformly heat the entire heating chamber 45 in the distributed heating mode in the initial stage of heating start, and shifts to the local heating mode when a difference in the temperature distribution in the heating chamber 45 begins to occur. Also good. Since there is no difference in the temperature distribution in the heating chamber 45 at the initial stage of heating, the distributed heating mode can efficiently raise the temperature of the entire heating chamber 45.

  Further, in the initial stage of starting heating, the control means 52 may first locally heat the vicinity of the center in the heating chamber 45. Normally, when the heat treatment is started from a state where there is no difference in temperature distribution in the heating chamber, the temperature in the vicinity of the center of the heating chamber is most difficult to increase. Therefore, the entire heating chamber can be efficiently uniformly heated by first locally heating the vicinity of the center in the heating chamber 45 and then performing distributed heating to uniformly heat the entire heating chamber.

  In addition, the motors 50 and 51 that drive the rotating antennas 48 and 49 may be, for example, stepping motors. At this time, the control means 52 is good to control the timing which inputs a pulse with respect to each stepping motor attached to each rotation antenna 48, 49 so that a time difference may be provided for each stepping motor and not simultaneously. If a pulse is input at the same time, the required current increases at that timing, and a circuit capable of handling a large current must be installed in the microwave oven 41. However, the circuit becomes larger by inputting a pulse with a time difference. Can be prevented.

  Next, the operation of the microwave oven 41 of the present embodiment will be described. First, the operation at the initial stage of heating will be described with reference to FIG.

  First, when the heat treatment is started, the magnetron 43 generates a microwave, and the microwave is transmitted into the heating chamber 45 through the waveguide 44 (S101). At this time, the infrared sensor 54 detects the temperature distribution in the heating chamber 45 at the initial stage of heating, and the control means 52 stores the detection result of the temperature distribution (S102).

  Next, the control means 52 rotates, for example, the rotating antennas 48 and 49 at a constant speed in order to realize distributed heating (S103). After a certain period of time, the infrared sensor 54 detects the temperature distribution in the heating chamber 45 again (S104).

  Then, the heating initial stage end determination unit 523 of the control means 52 determines the temperature distribution in the heating chamber 45 in the initial heating stage detected in the stage of S102 and the heating chamber 45 after a predetermined time detected in the stage of S104. With reference to the temperature distribution, it is determined whether or not a certain condition for determining the end of the initial heating stage is satisfied. When the determination condition is not satisfied (S105-No), the inside of the heating chamber 45 is continuously dispersed and heated, and the temperature distribution in the heating chamber 45 is detected again after a predetermined time.

When the determination condition is satisfied (S105-Yes), the process proceeds to a step of determining whether or not each area where the infrared sensor 54 detects the temperature is an area where food is placed. In this step, for example, the temperature increase rate per unit time of each area where the temperature is detected is referred to, and if it is equal to or greater than a predetermined value, it is determined that food is placed in that area. In addition, the initial temperature is referred to for each area where the temperature is detected, and when the initial temperature is negative (for example, frozen food is assumed), the area is determined to be an area where food is placed. May be. As described above, in the step of S106, among all the regions in the heating chamber 45, the region where the food is placed and the other region where the food is not placed are discriminated, and the control means 52 is determined.
Remember it. (S106).

  When the initial heating stage ends, the microwave oven 41 proceeds to the heating feedback stage. The operation in the heating feedback stage will be described with reference to FIG. The infrared sensor 54 of the microwave oven 41 detects the entire temperature distribution in the heating chamber 45 after the initial heating stage is completed (S107). And the area | region of the minimum temperature in the area | region where it determines with the foodstuff being mounted in the heating chamber 45 is extracted, ie, the lowest temperature location is extracted among foodstuff locations (S108).

  It is determined whether or not the minimum temperature location is any one of B2, B3, C2, and C3 in FIG. 17 (S109). When the minimum temperature location is any one of B2, B3, C2, and C3 (S109-Yes), the control means 52 causes the rotating antennas 48 and 49 to heat the center in the heating chamber 45, that is, Operation control is executed to stop the rotating antennas 48 and 49 at the stop positions shown in FIGS. 13 and 14 (S117).

  When the lowest temperature location is not any of B2, B3, C2, and C3 (S109-No), it is determined whether the lowest temperature location is any of B1 and C1 among the food locations. (S110).

  When the lowest temperature portion is one of the areas B1 and C1 (S110-Yes), the control means 52 causes the rotating antennas 48 and 49 to rotate in the direction in which the rotating antennas 48 and 49 heat the left direction in the heating chamber 45. , 49 are controlled so as to stop (S118).

  If the lowest temperature location is neither B1 nor C1 (S110-No), it is then determined whether the lowest temperature location is B4 or C4 among the food locations (S111).

  When the lowest temperature location is one of B4 and C4 (S111-Yes), the control means 52 causes the rotating antennas 48 and 49 to rotate in the direction in which the rotating antennas 48 and 49 heat the right direction in the heating chamber 45. , 49 are controlled so as to stop (S119).

  If the lowest temperature location is neither B4 nor C4 (S111-No), it is subsequently determined whether the lowest temperature location of the food location is A2 or A3 (S112).

  When the lowest temperature location is any one of A2 and A3 (S112-Yes), the control means 52 causes the rotating antennas 48 and 49 to rotate in the direction in which the rotating antennas 48 and 49 heat the forward direction in the heating chamber 45. , 49 are controlled so as to stop (S120).

  When the lowest temperature location is not in any of the areas A2 and A3 (S112-No), it is subsequently determined whether the lowest temperature location of the food location is either D2 or D3 (S113). .

  When the lowest temperature location is one of D2 and D3 (S113-Yes), the control means 52 causes the rotating antennas 48 and 49 to rotate in the direction in which the rotating antennas 48 and 49 heat the rearward direction in the heating chamber 25. , 49 are controlled so as to stop (S121).

  If the lowest temperature location is neither D2 nor D3 (S113-No), the control means 52 continues to disperse heating in which the inside of the heating chamber 45 is uniformly heated by rotating the rotating antennas 48 and 49 constant. The mode is changed (S114).

  The control means 52 performs an end determination after executing any one of steps S114 and S117 to S121 (S115). For example, when the maximum temperature of the food temperature distribution exceeds a preset temperature, the heat treatment end determination condition for determining that the heat treatment is to be terminated, or when the average temperature of the location determined as food exceeds the set temperature It is determined whether or not a heat treatment end determination condition for determining to end the heat treatment is satisfied.

  When the heat treatment end determination condition is satisfied (S115-Yes), the heat treatment is ended (S116). When the heat treatment end determination condition is not satisfied (S115-No), the process proceeds to the step of S107, and the steps after S107 are repeated again.

  As described above, the microwave oven 41 of the present embodiment can intensively heat a specific portion in the heating chamber 45 by the two rotating antennas 48 and 49, and is heated during the heat treatment. Since the temperature distribution of the food that is a product can be detected and a spot can be applied to the lowest temperature portion of the food to locally heat the food, the food can be heat-treated evenly.

  In addition, the local heating and the dispersion heating can be switched according to the temperature distribution of the food, that is, the microwave can be concentrated at a necessary place, so that the food can be efficiently heated in a short time.

  Note that the operation control in the heating feedback stage described in FIG. 19 is not limited to the order of searching for the lowest temperature portion of the food, and may be executed in other orders as long as the entire food is searched as a result. good.

  Regarding heating feedback control, for example, each region (A1 to A4, B1 to B4, C1 to C4, D1 to D4) in the heating chamber 45 is divided into the central region A (B2, B3, C2, and C3) and the left region. B (B1, C1), right region C (B4, C4), front region D (A2, A3) and rear region E (D2, D3) are classified into the average temperature of the food parts in the classified region Heat feedback may be performed based on the above. In this case, since the local heating location is determined based on the average temperature of the food location within the classified area (A to E), even if only one location of the food is extremely low, Centralized heating can be performed on a portion that needs to be heated.

  Next, the heating element will be described. In the present embodiment, the structure is such that there are two tube heaters 79, each of which has a glass tube on the outside of the heater wire as a heating element, and the rotating antennas 48 and 49 have strong radiation directivity as shown in FIG. Compared with the end portions 60a and 61a, the heater wire is arranged at a position where the height is lower by N (about 10 mm).

  20A is a view of the mounting table 46 as viewed from above, and FIG. 20B is a cross-sectional view as viewed from the solid arrow lines 461 and 461 in FIG. 20A. For the sake of clarity, the drive areas 481 and 491 of the rotating antennas 48 and 49 and the tube heater 79 that are not actually visible are indicated by broken lines. The mounting table 46 is provided with a stepped portion 463 (a concave portion when viewed from the top and a convex portion when viewed from the bottom), which is a typical concave or convex portion, on the flat surface 462 as an instruction means. The step portion 463 is disposed outside the driving regions 481 and 491 and inside the tube heater 79.

  As described above, in the present embodiment, the heater wire of the tube heater 79 is disposed at a position lower than the strong radiation directivity end portions 60a and 61a of the rotary antennas 48 and 49, so that the end portions 60a of the rotary antennas 48 and 49 are arranged. , 61a can reach the food without being disturbed by the heater wire of the conductor portion of the tube heater 79.

  Further, in the present embodiment, a step portion 463 is provided as an instruction means for instructing a place where food should be placed on the mounting table 46, and the step portion 463 is a place facing the rotary antennas 48 and 49 inside the tube heater 79. Is configured to instruct. The microwave heater can reach the inside of the tube heater 79 opposite to the rotating antennas 48 and 49 without causing the tube heater 79 to get in the way, so the location where the microwave reaches can be indicated as the place where the food should be placed. Since the food can be placed in an area where microwaves can be reliably applied, the user's consciousness can be raised, and the desired heating distribution can be realized.

  Further, according to the present embodiment, the location is indicated by the step portion 463 formed of a concave portion or a convex portion provided on the mounting table 46 as the instruction means, so that the user can easily touch the step portion 463. Can recognize where to put.

  Note that the step portion 463 of this embodiment is a concave portion when viewed from above because of a shape in which a flat plate is partially extruded as shown in FIG. 20B, and a convex portion when viewed from below. However, it may be upside down, and other than that, a flat plate with a groove (when viewed from the top, flat when viewed from the bottom, or a flat plate with a ledge) It can also be thought of as a thing (convex when viewed from above and flat when viewed from below). In addition, even if the stepped portions are not connected once, they may be arranged at several concave or convex portions, or of course, the concave and convex portions may be arranged on the same plane.

  Although various embodiments of the present invention have been described above, the present invention is not limited to the matters shown in the above-described embodiments, and those skilled in the art can make modifications and applications based on the description and well-known techniques. This is also the scope of the present invention, and is included in the scope of seeking protection.

  In particular, the antenna may have a configuration in which a plurality of antennas are different, or may be configured with other antennas in addition to the patch antenna, the rotating waveguide, and the slot antenna. Also, it is easy to combine a plurality of instruction means.

  Further, as another method of the instruction means, a configuration in which another part such as a seal is attached to the mounting table may be used. Of course, instead of instructing directly on the mounting table, an indirect instruction method may be used in which the state after the user places food is photographed with a CCD camera, displayed on the screen, and instructed on the screen.

  In addition, the antenna and the heating element are provided at the bottom of the heating chamber, but may be the upper part or the side surface. In this case, as a matter of course, the relative positional relationship between the heating element and the antenna is as follows. It is located on the side opposite to the side, which also means that the heating element is at a lower position than the antenna.

  Furthermore, each configuration described in each embodiment may be applied to other embodiments, and this is also an example of the present invention and is included in the scope for which protection is sought. For example, the control by the infrared sensor and control means and the origin detection configuration described in the third embodiment are applied to the first and second embodiments, or the instruction means shown in the first or second embodiment is implemented. For example.

  The microwave heating apparatus of the present invention has the effect of realizing the intended heating distribution even when there is a heating element around the rotating antenna when the heating distribution is controlled by the direction of the rotating antenna. Microwave ovens, microwave ovens, various dielectric heating and thawing devices as cooking utensils, heating devices in industrial fields such as semiconductor devices using microwaves, drying devices, ceramics heating, sintering or biochemistry It is useful for applications such as reaction.

Plan sectional drawing which shows schematic structure of the microwave heating apparatus in Embodiment 1 of this invention Same sectional view showing schematic configuration of microwave heating apparatus The top view which shows the shape of the rotation antenna of the microwave heating device Same as above, configuration diagram showing positional relationship between insulator and sheathed heater of microwave heater The same, the block diagram which shows the positional relationship of the direction of the rotation antenna of the microwave heating device and the sheathed heater The top view which shows the mounting base of a microwave heating apparatus similarly (A) (b) (c) is a top view which shows the rotating antenna structure of the microwave heating apparatus in other embodiment of this invention. Plan sectional drawing which shows schematic structure of the microwave heating apparatus in Embodiment 2 of this invention The same, the block diagram which shows the positional relationship of the rotary antenna of the microwave heating device and the sheathed heater Same as above, configuration diagram showing positional relationship between insulator and sheathed heater of microwave heater Same part sectional drawing showing schematic structure of illumination means The top view which shows the mounting base of a microwave heating apparatus similarly Plan sectional drawing which shows schematic structure of the microwave heating apparatus in Embodiment 3 of this invention Same sectional view and block diagram showing schematic configuration of microwave heating apparatus Configuration diagram explaining the origin detection mechanism of the rotating antenna Same cross-sectional configuration diagram of temperature distribution detection means The figure explaining the infrared temperature detection spot The flowchart explaining the control operation in the heating initial stage The flowchart explaining the control operation of the heating feedback stage (A) The top view which shows the mounting base of a microwave heating apparatus, (b) The same, sectional drawing of a mounting base Front sectional view showing a schematic configuration of a conventional microwave heating apparatus

Explanation of symbols

1, 20, 43 Magnetron (microwave generating means)
2, 21, 44 Waveguide 3, 22, 45 Heating chamber 4 Food (object to be heated)
5, 38, 46 Mounting table 8, 23, 48, 49 Rotating antenna 9, 50, 51 Motor (driving means)
10, 52 Control means 12, 31 Seed heater (heating element)
12a Electric power feeding part 14, 33 Insulating (heating element holding means)
27, 851, 861 End 19a, 19b, 19c, 19d Marking (indicating means)
36 Illumination means 39 Spot points (instruction means)
79 Tube heater (heating element)
312 Power supply portion 463 Step portion (concave or convex (instruction means))

Claims (12)

A heating chamber for storing an object to be heated; a microwave generating means; a waveguide for transmitting microwaves from the microwave generating means; and a rotating antenna for radiating microwaves from the waveguide into the heating chamber; A microwave including a heating element disposed around the rotating antenna, a driving unit that rotationally drives the rotating antenna, and a control unit that controls the driving unit to control the stop position of the rotating antenna. Heating device. The microwave heating device according to claim 1, wherein the heating element is arranged at a position lower than the rotating antenna. The microwave heating apparatus according to claim 1, wherein the control means is configured to stop the end portion of the rotating antenna having high directivity at a position higher than the heating element. The microwave heating apparatus according to claim 1, wherein the control means is configured to stop the end portion of the rotating antenna having strong directivity in a direction in which the distance to the heating element is far away. The microwave heating apparatus according to claim 1, wherein the control means is configured to stop the end portion having strong directivity of the rotating antenna toward the feeding portion of the heating element. In order to regulate the position of the heating element, it has a heating element holding means made of a dielectric material attached to the wall surface of the heating chamber, and the control means has a strong directivity end of the rotating antenna facing the heating element holding means. The microwave heating apparatus according to claim 1, wherein the microwave heating apparatus is configured to be stopped. In order to regulate the position of the heating element, it has a heating element holding means made of a dielectric material attached to the wall surface of the heating chamber, and the heating element holding means regulates the position of the heating element in a direction far from the rotating antenna. The microwave heating apparatus according to claim 1. The microwave heating apparatus according to claim 7, wherein the heating element holding means is configured to restrict the position of the heating element in a direction close to the rotating antenna. A mounting table disposed in the heating chamber for mounting the object to be heated; and indicating means for indicating a place on the mounting table on which the object to be heated is to be placed. The microwave heating device according to any one of claims 1 to 8, wherein the microwave heating device is configured to indicate a location opposite to the device. The microwave heating apparatus according to claim 9, wherein the instruction unit is configured to indicate a place by a marking drawn on the mounting table. The microwave heating apparatus according to claim 9, wherein the instruction unit is configured to indicate a place by a concave portion or a convex portion provided on the mounting table. The microwave heating apparatus according to claim 9, further comprising an illuminating unit that illuminates the mounting table, wherein the instructing unit indicates a location by illuminating the mounting table with the illuminating unit.