JP5080827B2 - Microwave heating device - Google Patents

Description

  The present invention relates to a microwave heating apparatus that dielectrically heats an object to be heated.

  A microwave oven, which is a typical microwave heating device, can directly heat food, which is a typical object to be heated, so it becomes an essential device in daily life with the simplicity that does not require the preparation of a pan or pot. ing. In the microwave oven, the size of the space for storing food in the heating chamber through which microwaves propagate is approximately 300 to 400 mm in the width direction and the depth direction, and approximately 200 mm in the height direction. Also, in recent years, the heating chamber has a wide breadth that has been made more convenient so that a plurality of dishes can be heated side by side by flattening the bottom surface of the space for storing foodstuffs, making the width dimension 400 mm or more and relatively larger than the depth dimension. Products with shapes have also been put into practical use.

  By the way, the microwave used in the microwave oven has a wavelength of about 120 mm, a strong and weak electric field distribution (hereinafter referred to as radio wave distribution) is generated in the heating chamber, and the shape of the object to be heated and its physical characteristics It is known that the effects of the above are synergistic and heating unevenness occurs. In particular, in a heating chamber having a large width direction dimension as described above, it is necessary to increase the uniformity of heating in order to simultaneously heat foods placed on a plurality of tableware.

  Conventionally, this type of microwave heating apparatus includes a single radiating antenna and rotationally drives the antenna (see, for example, Patent Document 1). However, as a measure for improving the uniformity of heating, a plurality of radiating antennas are used. Have been proposed, or have a plurality of high-frequency stirring units.

  However, even if the interior is large, it does not always heat a large amount of food. For example, when heating a full mug of milk, it is considered more efficient to concentrate only on milk without heating the entire interior uniformly. . Also, even when heating multiple foods at the same time, if there is a difference in the temperature of the food, for example, when heating frozen food and food at room temperature at the same time, you may want to heat only the low-temperature food intensively. is there. In addition, if it is like a bento box lunch, one container contains foods (pickles, salads, desserts, etc.) that you do not want to heat, and only the foods to be heated (rice, side dishes, etc.) are heated intensively. Sometimes you want to. In such a case, the function which can carry out local concentration heating instead of the whole uniform heating is needed. For this reason, there has been proposed a technique in which a plurality of radiation antennas are switched and central heating is performed by controlling a stop position (for example, see Patent Document 2).

JP-A-9-27389 JP 2006-286443 A

  However, in the microwave heating apparatus disclosed in Patent Document 2, localized concentrated heating is possible according to the purpose, and uniform heating has become a reality, but heating is still started like frozen food and room temperature food. It is difficult to simultaneously heat a plurality of objects to be heated at different temperatures at the same time, and the current situation is that they cannot cope with the difference in each amount.

  The present invention has been made in view of such circumstances, and is capable of simultaneously heating a plurality of objects to be heated having different temperatures at the start of heating, and capable of uniformly heating even if there is a difference in each amount. An object is to provide a wave heating device.

The microwave heating apparatus of the present invention places microwave generation means, a waveguide for transmitting microwaves from the microwave generation means, a heating chamber connected to the waveguide, and an object to be heated. Therefore, a mounting table disposed in the heating chamber, a heated object storage space formed above the mounting table in the heating chamber, temperature detection means for detecting the temperature in the heating chamber, and a front of the heating chamber An antenna space formed below the mounting table; and a plurality of rotating antennas having radiation directivities disposed in the antenna space from the waveguide for radiating microwaves in the waveguide into the heating chamber; and a control means for controlling the driving means for rotating each of the plurality of the rotating antennas respectively, wherein the control means takes the temperature data of a predetermined number of measurement points of swung controlling the temperature detecting means, A uniform heating by rotating a plurality of the rotating antennas and a concentrated heating for directing a portion having a strong radiation directivity of the plurality of rotating antennas toward a predetermined portion of the object to be heated, The heated object is placed on the mounting table, and the control means takes in temperature data of the heated objects from the temperature detecting means at the start of heating, and detects the heated objects detected based on the temperature data. When one of the products is frozen food, if the amount of the frozen food is large, the heating time of the frozen food is set longer than that when the amount of the frozen food is small, and the frozen food is intensively heated.

  According to the above configuration, based on the temperature detection information from the temperature detection means, of the at least two heated objects having different temperatures at the start of heating, the heated object having a lower temperature after a predetermined time has elapsed since the start of heating. Since the direction of each rotating antenna is controlled by controlling the driving means based on the determination result, a plurality of objects to be heated at different temperatures at the start of heating can be heated at the same time. Even if there is a difference in amount, it can be heated uniformly.

  In the microwave heating apparatus of the present invention, the temperature detection means detects the temperature in the heating chamber at a plurality of points, and the control means determines the amount of the object to be heated by the temperature detection means. This is based on the number of points for temperature detection.

  According to the above configuration, the amount of the object to be heated is determined based on the number of points of the temperature detected by the temperature detection means at a plurality of points in the heating chamber, so that the amount of the object to be heated can be accurately grasped.

  According to the microwave heating apparatus of the present invention, based on the temperature detection information from the temperature detection means, the temperature after the elapse of a predetermined time from the start of heating is low among at least two heated objects having different temperatures at the start of heating. Since the direction of each rotating antenna is controlled by controlling the driving means based on the determination result, the plurality of heated objects having different temperatures at the start of heating are simultaneously heated. In addition, even if there is a difference in each amount, it is possible to heat uniformly.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described in detail with reference to the drawings.

  1 to 4 are configuration diagrams of a microwave heating apparatus according to an embodiment of the present invention. FIG. 1 is a cross-sectional view seen from the front, FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. Is a cross-sectional view taken along the line BB ′ of FIG. 1, and FIG. 4 is a data processing diagram of the infrared sensor. Note that the microwave heating apparatus of the present embodiment is an application of the present invention for cooking for heating and thawing food. However, in addition to cooking, heating, drying, sintering, or biological Of course, it can also be applied to uses such as chemical reactions.

  The microwave heating device 31 has a waveguide 33 that transmits a microwave radiated from a magnetron 32, which is a typical microwave generation means, and a width dimension (about 410 mm) connected to the upper portion of the waveguide 33. A heating chamber 34 having a shape larger than the dimension in the depth direction (about 315 mm) and a typical food to be heated (not shown) are placed in the heating chamber 34 to place low loss such as ceramic and glass. A mounting table 35 having a property that microwaves can be easily transmitted because it is made of a dielectric material, and a heated object storage space 36 that is formed above the mounting table 35 in the heating chamber 34 and can substantially store food. And the antenna space 37 formed below the mounting table 35 in the heating chamber 34 and the microwave in the waveguide 33 are radiated into the heating chamber 34. The two rotating antennas 38 and 39 attached at symmetrical positions with respect to the width direction of the heating chamber 34, motors 40 and 41 as representative driving means capable of rotationally driving the rotating antennas 38 and 39, and the motor 40 , 41 to control the orientation of the rotating antennas 38, 39, and a memory 61 for storing the stopping positions of the rotating antennas 38, 39, etc. A specific food is concentratedly heated by controlling a portion having a strong radiation directivity in a predetermined direction. The specific control method will be described later.

  The rotary antennas 38 and 39 are conductive materials having a diameter of about 18 mm and a substantially cylindrical shape that pass through the coupling holes 43 and 44 having a diameter of about 30 mm provided on the boundary surface between the waveguide 33 and the bottom surface 42 of the heating chamber. The coupling portions 45 and 46, and the coupling portions 45 and 46 are electrically connected to and integrated with the upper ends of the coupling portions 45 and 46 by caulking or welding, and are made of a conductive material having a larger area in the horizontal direction than in the vertical direction. Parts 47 and 48, and the coupling holes 43 and 44 are fitted to the shafts 49 and 50 of the motors 40 and 41 so that the centers of the coupling holes 43 and 44 are rotationally driven. On the other hand, since the shape is not constant, the radiation directivity is adopted.

  Since the waveguide 33 has a T-shape when viewed from above as shown in FIG. 3 and has a bilaterally symmetric shape, the distance from the magnetron 32 to the coupling portions 45 and 46 is equal, and the coupling portions 45 and 46 are the same. Are attached at symmetrical positions also in the width direction of the heating chamber 34, so that the microwaves radiated from the magnetron 32 are substantially evenly distributed in the heating chamber 34 via the waveguide 33 and the rotating antennas 38 and 39. Distributed. The waveguide may be straight and may have an I shape in which a magnetron is disposed at one end and a coupling portion is provided between the waveguide and the other end. The microwaves can be distributed substantially evenly.

  The radiating portions 47 and 48 have the same shape, and the radiating portion upper surfaces 51 and 52 have a substantially quadrilateral R shape, and the radiating portion bending portion 53 bent to the heating chamber bottom surface 42 side on the opposite two sides, 54, and is configured to limit the emission of microwaves to the outside of the two sides. The distance between the heating chamber bottom surface 42 and the radiating portion upper surfaces 51 and 52 is about 10 mm, and the radiating portion bending portions 53 and 54 are pulled down to a position lower by about 5 mm. The remaining two sides have different horizontal lengths from the coupling portions 45 and 46 to the end portions, and the end portions 55 and 56 and the coupling portions 45 and 46 whose length from the center of the coupling portions 45 and 46 is about 75 mm. The end portions 57 and 58 having a length from the center of about 55 mm are formed. Moreover, the dimension of the width direction of the edge parts 45 and 46 is 80 mm or more. In this configuration, the rotating antennas 38 and 39 can increase the radiation directivity in the direction from the coupling portions 45 and 46 to the end portions 57 and 58.

  The control unit 60 drives a CPU (Central Processing Unit), a nonvolatile memory such as a ROM storing a program for controlling the CPU, a volatile memory such as a RAM used for the operation of the CPU, and the motors 40 and 41. A driver and a drive circuit for driving the magnetron 32 (both not shown) are provided. The memory 61 is a non-volatile memory such as a flash memory that can be rewritten and does not lose data even when the power is turned off.

  In this configuration, when heating general foods uniformly, it is not necessary to be particular about the place of placement as in the conventional microwave heating device, and the rotating antennas 38 and 39 are also rotated at a constant speed as in the prior art. Alternatively, if there is a pattern for heating uniformly with a constant rotation / stop pattern, that may be used. On the other hand, when concentrated heating is performed, control is performed using temperature data (temperature detection information) input from an infrared sensor (temperature detection means) 59.

  FIG. 4 is a data processing diagram of the infrared sensor 59 when the eight-element type infrared sensor 59 attached to the right side surface is scanned from the back to the front to acquire data at address 19. The control unit 60 controls the infrared sensor 59 to swing, and takes in temperature data of 152 points per scan (one way). Incidentally, the time of one scan is 350 ms × 19 = 6.65 seconds.

  The control unit 60 controls the infrared sensor 59 to detect the food placed in the cabinet, and if there is a food with a low temperature, the end of the rotating antennas 38 and 39 is used to concentrate the food. 57 and 58 are controlled by a rotation / stop pattern capable of centrally heating food having a low temperature. As a method for determining the point of the portion where the food is placed, there is a method for determining whether or not the food is based on the difference between the initial temperature and the temperature after a predetermined time has elapsed.

  In order to turn the rotating antennas 38 and 39 in a predetermined direction, a stepping motor is used as the motors 40 and 41, or even if the motor rotates at a constant speed, the reference position is detected and stopped by the energization time from the reference position. Various methods such as controlling the position can be considered.

  Next, specific control will be described. In FIG. 2, the setting part 62 is arrange | positioned at the lower part of the door 63, and it is determined whether the control part 60 performs concentrated heating based on the content which the user set using the setting part 62. In FIG. Based on the determination result, the control unit 60 controls the magnetron 32 and the motors 40 and 41. For example, when the user sets “rice warming” by the setting unit 62, the control unit 60 rotates the rotating antennas 38 and 39 by the motors 40 and 41 so that the whole is uniform for a certain period of time. To control. Then, after a certain period of time, the temperature difference at the point where it is determined that there is food is compared periodically, and if the temperature difference is more than a certain temperature, the low temperature food is concentrated and heated, eliminating the temperature difference. Control to return to a uniform heating pattern.

  On the other hand, when the user sets “milk warming” by the setting unit 62, the control unit 60 determines that central heating is necessary, drives the motors 40 and 41 to rotate the rotating antennas 38 and 39, and the radiation unit. Control is performed so that the end portions 57 and 58 of the 47 and 48 are stopped when they are respectively directed toward the center. This can intensively heat the bottom of the milk. At this time, the stop positions of the rotating antennas 38 and 39 are stored in the memory 61 by the control unit 60.

  In addition, when the user sets “simultaneous warming of frozen food and normal temperature food” by the setting unit 62, the control unit 60 uses the rotating antennas 38, 39 by the motors 40, 41 so that the entire time is uniform. Is controlled to rotate at a constant speed. Then, after a certain period of time, based on the temperature detection information from the infrared sensor 59, among the at least two foods having different temperatures at the start of heating, the amount of the food having the lower temperature after the predetermined time has elapsed since the start of heating And the direction of the rotating antennas 38 and 39 is controlled by controlling the motors 40 and 41 based on the determination result. As a result, a plurality of foods having different temperatures at the start of heating can be heated at the same time, and even if there is a difference in each amount, it can be heated uniformly.

  The microwave heating device 31 according to the present embodiment can perform heating using a single microwave and heating using both microwave and steam (steam), and heating control in each will be described later.

  As described above, according to the present embodiment, the two rotating antennas 38 and 39 coupled to the common waveguide 33 arranged on the lower side of the heating chamber 34 are positioned symmetrically with respect to the width direction of the heating chamber 34 having a wide width. Since they are arranged, at least a symmetrical heating distribution can be obtained, and the microwave radiation pattern can be varied as compared with the case of one rotating antenna. Thereby, the heating distribution of the whole inside of a store | warehouse | chamber can be equalized easily.

  Further, by controlling the direction of the end portions 57 and 58, which are the parts having strong radiation directivities of both the rotating antennas 38 and 39, microwaves can be radiated strongly in a predetermined direction. Centralized heating can be performed for each food item. That is, the temperature detection information from the infrared sensor 59 can be intensively heated at a low temperature portion. Thereby, “frozen food” and “room temperature food” having different starting temperatures can be heated at the same time.

  In the present embodiment, there are infinite combinations for stopping / rotating control of the rotating antennas 38 and 39. Therefore, the combination for realizing uniform heating can be changed, and the combination can be changed for each menu. is there. Also, for example, one side is stopped and the other is rotated, or one is stopped halfway and the other is rotated, and the one that has been stopped from the middle is rotated so that the one that has been rotated is stopped. Various control methods are possible. Such a control method is effective in the case where it is desirable that the time between concentrated heating and uniform heating is desirable because concentrated heating is too concentrated. At this time, the ratio between rotation and stop may be optimized as appropriate.

  Furthermore, the microwave heating device 31 of the present embodiment has a very simple configuration in which the directions of the two rotating antennas 38 and 39 coupled to one waveguide 33 are controlled, and the entire interior is uniformly heated. Even when switching between local and centralized heating, there is no risk of changing the coupling state of microwaves, and it is safe and there is no need for severe dimensional management such as gap management, so it is realized with a very realistic configuration it can.

  In addition, the microwave in the waveguide 33 is drawn out to the heating chamber 34 side from the gap between the coupling holes 43 and 44 and the coupling portions 45 and 46, but the radiation portion 47 integrated with the coupling portions 45 and 46, Since the shape of 48 is not a fixed shape (for example, a circle, a cylinder, a cone, a sphere, etc.) with respect to the direction of rotation, the ease of propagation of microwaves differs depending on the direction. In a direction where the radiation directivity is strong and difficult to propagate, the radiation directivity is such that the radiation directivity is weak. When the rotating antennas 38 and 39 are rotating at a constant speed, if a microwave with a constant output is radiated for a time sufficiently longer than the rotation period, the microwaves are averaged in the direction of rotation. Are heated at the same level and have a concentric heating distribution (for example, strong heating in a circular shape or strong heating in a donut shape).

  On the other hand, when the rotation antennas 38 and 39 are stopped or the rotation speed and the output of the microwave are changed to limit the heating mainly in a predetermined direction, the heating distribution is not concentric but is determined by the radiation directivity. An object to be heated (or a part of the object to be heated) in the vicinity of the portion having a strong radiation directivity of the rotating antennas 38 and 39 is easily heated strongly and can be heated intensively.

  Further, in this embodiment, the rotating antennas 38 and 39 are stopped and the microwave is continuously propagated in a state having a strong radiation directivity in a predetermined direction, so that a specific heated object is easily concentratedly heated. be able to.

  Further, in the present embodiment, since the central heating is performed by controlling the rotating antennas 38 and 39 based on the setting contents, the central heating is usually performed at a constant rotation, and the central heating is easily performed. And can be switched. From the user's point of view, the microwave heating device automatically switches between uniform heating and concentrated heating as long as the setting is made, so that the risk of mistakes can be reduced.

  Next, the operation of the microwave heating device 31 of the present embodiment will be described with reference to the flowcharts shown in FIGS. 5 and 6 are flowcharts showing a warming process by heating only with microwaves, and FIGS. 7 and 8 are flowcharts showing a warming process by simultaneous heating of microwaves and steam. In this explanation, it is assumed that frozen food and normal temperature food are placed in the cabinet. In the following, description will be given in the order of “warming process by heating only with microwaves” and “warming process by simultaneous heating of microwaves and steam”.

(Warm treatment by heating only with microwaves)
5 and 6, first, heating is performed for a predetermined time with power P1, which is a microwave output (step S10). After heating with the power P1, it is determined whether or not the food is frozen food (step S11). This determination is made based on temperature detection information from the infrared sensor 59 (information detected at 152 points). If there is even one freezing temperature point, it is determined that there is frozen food, and the process proceeds to step S12. If there are no points, the process proceeds to step S13.

  When the process proceeds to step S12, a refrigeration detection limit (time) is set. When the process proceeds to step S13, a room temperature detection limit (time) is set. After setting the detection limit for freezing or the detection limit for room temperature, it is determined whether or not food has been detected within a predetermined scan (for example, 5 to 7 scans) of the infrared sensor 59 (step S14). At this time, if there is food in the cabinet, the temperature will gradually rise by heating, so if you look for the point where the temperature went up, the point (in this case, the size of the food is the temperature detection point) It is possible to determine that there is a food item at a plurality of points).

  If the food can be detected within the predetermined scan, the process proceeds to step S15 to determine whether or not the temperature difference ΔT is equal to or greater than the predetermined value Δ1, and if the temperature difference ΔT is less than the predetermined value Δ1, the process returns to step S14, If the value is Δ1 or more, it is determined whether or not food can be detected (step S17). If it is not possible to detect food in this determination, the process returns to step S14, and if it can be detected, the process proceeds to step S18.

  On the other hand, if no food is detected within the predetermined scan in step S14, the process proceeds to step S16 to determine whether the temperature difference ΔT is equal to or greater than the predetermined value Δ2. In this determination, if the temperature difference ΔT is less than the predetermined value Δ2, the process returns to step S14, and if it is equal to or greater than the predetermined value Δ2, the process proceeds to step S17. When the process proceeds to step S17, as described above, it is determined whether or not the food can be detected. If the food cannot be detected, the process returns to step S14. If the food can be detected, the process proceeds to step S18. The predetermined values Δ1 and Δ2 are usually different values, but may be the same value.

  When the process proceeds to step S18 assuming that the food can be detected, it is determined whether or not the food is frozen. In this case, it is determined whether or not it is frozen food by determining whether or not it is frozen at each temperature detection point of “152”. If it is frozen food, it will be determined whether the internal temperature is Cool (step S19). In this case, the point for determining the internal temperature may be anywhere as long as it is in the internal storage, but it is usually determined where there is no food. If the internal temperature is Cool in this determination, the K1 constant in the freezing / Cool start menu is set (step S21), and if the internal temperature is not Cool, the K2 constant is set in the freezing / Hot start menu. (Step S22). On the other hand, if it is not frozen food (that is, normal temperature food) in the determination of step S18, it is determined whether or not the internal temperature is Cool (step S20). The K3 constant in the / Cool start menu is set (step S23), and if the internal temperature is not Cool, the K4 constant in the normal temperature / Hot start menu is set (step S24).

  After performing any one of steps S21 to S24, the microwave output is set to power P1 'and heated for a predetermined time (step S25). After heating with the power P1 ', it is determined again whether it is a frozen food (step S26). In this case as well, similar to the processing in step ST11, the temperature detection information from the infrared sensor 59 (information detected at 152 points) is performed. If there is even one freezing point, the process proceeds to step S27, and if there is no freezing point, the process proceeds to step S39.

  When it is determined that the food is frozen in step S26 and the process proceeds to step S27, it is determined whether or not the detection is performed at a normal temperature location based on the detected temperature result (step S27). In this case, since the infrared sensor 59 has a characteristic of detecting a high-temperature portion first, the detection at the normal temperature location means that the temperature of the normal temperature food has increased, but the temperature of the frozen food has not increased. Means. Accordingly, when the amount of frozen food is large, the temperature does not rise easily. In such a case, the detection is made at a normal temperature location (that is, the determination in step S27 is “Yes”). And when it detects at a normal temperature location, the detection conditions (freezing A) in each step of step S36-step S38 mentioned later are set (step S28).

  On the other hand, in the determination of step S27, if it is not detected at a normal temperature location, it means that the temperature of the frozen food has risen. Therefore, the process proceeds to step S29, and the freezing point is a predetermined percentage (some points out of 152 points). ) Determine whether or not When the freezing point is equal to or less than the predetermined percentage, it is determined that the amount of the frozen food is small (that is, the determination in step S29 is “Yes”). And when the freezing point is below predetermined%, the detection condition (freezing B) in each step of step S36-step S38 mentioned later is set (step S30).

  After setting the detection condition (freezing A) or the detection condition (freezing B), the power P4 'for including the work of reducing the temperature difference is set and heated for a predetermined time (step S34). In addition, the process of step S31-step S33 is mentioned later. After heating with the power P4 ', it is determined again whether or not the internal temperature is Cool (step S35). If the internal temperature is Cool in this determination, it is determined whether or not it is detection (Cool) (step S36). That is, it is determined whether or not the temperature difference is reduced. If the temperature difference is reduced, the process proceeds to step S39, and if the temperature difference is not reduced, the process returns to step S35. On the other hand, if the internal temperature is not Cool in the determination in step S35, it is determined whether or not the detection is hot (step S37). That is, it is determined whether the temperature is hot and the temperature difference is reduced. If it is Hot and the temperature difference is reduced, the process proceeds to step S39, and if not, the process proceeds to step S38. In step S38, it is determined whether the limiter time has elapsed. That is, it is determined whether or not the time for performing the heating by the power P4 ', that is, the process for reducing the temperature difference has passed. If the limiter time has not elapsed, the process returns to step S35, and if the limiter time has elapsed, the process proceeds to step S39.

  If it progresses to step S39, it will be determined whether the quantity of all the foodstuffs in a store | warehouse | chamber is the small quantity 1 based on the number of detection points. If the amount is small 1, additional heating is performed for a time corresponding to "P1add (small amount 1)" (step S40). If it is not a small amount 1, it is determined whether it is a small amount 2 (> small amount 1) (step S41). If it is a small amount 2, additional heating is performed for a time corresponding to “P1add (small amount 2)” (step S41). S42). If it is not a small amount 2, it is determined whether it is a large amount (> small amount 2) (step S43). If it is a large amount, additional heating is performed for a time corresponding to “P1add (large amount)” (step S44). After performing any one process of step S40, step S42, or step S44, or when it is determined in step S43 that the amount is not large, the process proceeds to step S45, and the process is finished by heating with power P2 for a predetermined time.

  In the determination in step S29, if the freezing point exceeds a predetermined percentage, the detection condition (frozen C) for determination in steps S36 to S38 is set assuming that only frozen food is present (step S31). Then, it is determined whether or not the amount of all foods in the storage is large (step S32). If not, the process proceeds to step S39, and if it is large, it is determined whether there is a temperature difference (step S33). ). In this case, the difference between the high temperature portion and the low temperature portion is constantly monitored, and if there is no temperature difference, it is determined that the finish is uniform and the process proceeds to step S39. If there is a temperature difference, the process proceeds to step S34, in which power P4 'for including the work to reduce the temperature difference is set and heated for a predetermined time. Thereafter, the processes of steps S35 to S45 described above are performed.

(Warming treatment by simultaneous heating of microwave and steam)
7 and 8, first, heating is performed for a predetermined time with power P1, which is a microwave output (step S50), and then heating is performed for a predetermined time with power P2 (step S51). After heating with power P2, it is determined whether or not the food is frozen food (step S52). This determination is made based on the temperature detection information from the infrared sensor 59 (information detected at 152 points). If one point can be determined to be frozen, the process proceeds to step S53. If one point cannot be determined to be frozen, the process proceeds to step S57. move on.

  In step S53, heating is performed for a predetermined time with power P3. In this case, heating is performed for a time corresponding to freezing. After the heating with the power P3, it is determined whether or not the internal temperature is Cool based on the detected temperature result (step S54). If the internal temperature is Cool in this determination, a detection level for refrigeration / Cool start is set (step S55), and if the internal temperature is not Cool, a detection level for refrigeration / Hot start is set (Step S56). . On the other hand, if it is not frozen food (that is, normal temperature food) in the determination in step S52, heating is performed with power P3 for a predetermined time (step S57). In this case, heating is performed for a time corresponding to room temperature. After heating with this power P3, it is determined whether the internal temperature is Cool (step S58). If the internal temperature is Cool in this determination, the detection level for normal temperature / Cool start is set (step S59), and if the internal temperature is not Cool, the detection level for normal temperature / Hot start is set (Step S60). .

  After performing any one process of step S55, step S56, step S59, or step S60, it progresses to step S61 and it is determined whether the food could be detected. If the food cannot be detected in this determination, step S61 is repeated until it can be detected, and if it can be detected, the process proceeds to step S62. In step S62, heating is performed with power P4 for a predetermined time. After performing the heating with the power P4, it is determined whether or not the food can be detected within a predetermined scan (for example, 5 to 7 scans) (step S63). At this time, if there is food in the cabinet, the temperature gradually rises by heating, so if you look for the point where the temperature went up, the point (the size of the food is larger than the temperature detection point) Therefore, it can be determined that there are foods at a plurality of points).

  If the food can be detected within the predetermined scan, the process proceeds to step S64. If the food cannot be detected, the process proceeds to step S65. If the food can be detected within the predetermined scan and the process proceeds to step S64, it is determined whether or not the temperature difference ΔT is equal to or greater than the predetermined value Δ1. In this determination, if the temperature difference ΔT is less than the predetermined value Δ1, the process returns to step S63, and if the temperature difference ΔT is equal to or larger than the predetermined value Δ1, it is determined whether or not food can be detected (step S66). If it is not possible to detect food in this determination, the process returns to step S63, and if it can be detected, the process proceeds to step S67.

  On the other hand, if no food is detected within the predetermined scan in step S63, the process proceeds to step S65 to determine whether the temperature difference ΔT is equal to or greater than the predetermined value Δ2. In this determination, if the temperature difference ΔT is less than the predetermined value Δ2, the process returns to step S63. If the temperature difference ΔT is equal to or greater than the predetermined value Δ2, the process proceeds to step S66, and it is determined whether food can be detected. If it is not possible to detect food in this determination, the process returns to step S63, and if it can be detected, the process proceeds to step S67. The predetermined values Δ1 and Δ2 are usually different values, but may be the same value.

  If it progresses to step S67, it will be determined again whether it is frozen food. In this case as well, similar to the processing in step S52, the temperature detection information from the infrared sensor 59 (information detected at 152 points) is performed. If even one point is determined to be frozen food, the process proceeds to step S68. Otherwise, the process proceeds to step S80. When it is determined that the food is frozen in step S67 and the process proceeds to step S68, it is determined whether or not the detection is performed at a normal temperature location. As described above, since the infrared sensor 59 has a characteristic of detecting a high-temperature portion first, the detection at the normal temperature location means that the temperature of the normal temperature food has increased, but the temperature of the frozen food has increased. It means not. Therefore, when the amount of frozen food is large, the temperature does not rise easily. In such a case, the detection is made at a normal temperature location (that is, the determination in step S68 is “Yes”). And when it detects at a normal temperature location, the detection conditions (freezing A) in each step of step S77-step S79 mentioned later are set (step S69).

  On the other hand, in the determination of step S68, if it is not detected at the normal temperature location, it means that the temperature of the frozen food is rising, so the process proceeds to step S70, and the freezing point is a predetermined percentage (some points out of 152 points). ) Determine whether or not When the freezing point is equal to or less than the predetermined percentage, it is determined that the amount of the frozen food is small (that is, the determination in step S70 is “Yes”). When the freezing point is equal to or less than the predetermined percentage, a detection condition (freezing B) in each of steps S77 to S79 described later is set (step S71).

  After setting the detection condition (freezing A) or the detection condition (freezing B), the power P4 'for including the work of reducing the temperature difference is set and heated for a predetermined time (step S75). Steps S72 to S74 will be described later. After heating with the power P4 'for a predetermined time, it is determined again whether or not the internal temperature is Cool (step S76). If the internal temperature is Cool in this determination, it is determined whether or not it is detection (Cool) (step S77). That is, it is determined whether or not the temperature difference is reduced. If the temperature difference is reduced, the process proceeds to step S80. If the temperature difference is not reduced, the process returns to step S76. On the other hand, if the internal temperature is not Cool in the determination in step S76, it is determined whether or not it is detection (hot) (step S78). That is, it is determined whether the temperature is hot and the temperature difference is reduced. If the internal temperature is Hot and the temperature difference is reduced, the process proceeds to step S80, and if not, the process proceeds to step S79. In step S79, it is determined whether the limiter time has elapsed. That is, it is determined whether or not the time for performing the heating by the power P4 ', that is, the process for reducing the temperature difference has passed. If the limiter time has not elapsed, the process returns to step S76, and if the limiter time has elapsed, the process proceeds to step S80.

  If it progresses to step S80, it will be determined whether the quantity of all the foodstuffs in a store | warehouse | chamber is the small quantity 1. If it is a small amount 1, the power P5 is heated for a time corresponding to “P5 (small amount 1)” (step S81). If it is not a small amount 1, it is determined whether it is a small amount 2 (> small amount 1) (step S82). If it is a small amount 2, it is heated for a time corresponding to "P5 (small amount 2)" with power P5. (Step S83). If it is not a small amount 2, it is determined whether it is a large amount (> small amount 2) (step S84). If it is a large amount, it is heated for a time corresponding to "P5 (large amount)" with power P5 (step S85). . After performing any one of step S81, step S83, or step S85, or when it is determined in step S84 that the amount is not large, this processing is terminated.

  In the determination in step S70, if the freezing point exceeds a predetermined percentage, the detection condition (frozen C) for determination in steps S77 to S79 is set assuming that only frozen food is present (step S72). Then, it is determined whether or not the amount of all food items in the storage is large (step S73). If not, the process proceeds to step S80, and if it is large, it is determined whether there is a temperature difference (step S74). ). In this case, as described above, the difference between the high temperature portion and the low temperature portion is always monitored, and if there is no temperature difference, it is determined that the finish is uniform, and the process proceeds to step S80. If there is a temperature difference, the process proceeds to step S75, where power P4 'for including a work for reducing the temperature difference is set and heating is performed for a predetermined time. Thereafter, the above-described steps S76 to S85 are performed.

  As described above, according to the microwave heating device 31 of the present embodiment, the control unit 60 is based on the temperature detection information from the infrared sensor 59 and has at least two objects to be heated with different temperatures at the start of heating ( Of the frozen food and the normal temperature food), the amount of the heated object having a lower temperature after the elapse of a predetermined time from the start of heating is determined, and the motors 40 and 41 are controlled based on the determination result to control the rotating antenna 38. , 39 can be controlled, so that a plurality of objects to be heated having different temperatures at the start of heating can be heated at the same time, and even if there is a difference in each amount, heating can be performed uniformly.

  In addition, the controller 60 uses the infrared sensor 59 to detect the temperature in the heating chamber 34 at a plurality of points, and determines the amount of the object to be heated by the number of points, so the amount of the object to be heated is determined. Accurately grasp.

  INDUSTRIAL APPLICABILITY The present invention has an effect that a plurality of objects to be heated at different temperatures at the start of heating can be heated at the same time, and even if there is a difference in each amount, it can be heated uniformly, and various dielectrics such as food It can be applied to uses such as heating, thawing, ceramic heating, drying, sintering or biochemical reaction.

Sectional drawing seen from the front of the microwave heating device which concerns on one embodiment of this invention A-A 'sectional view of the microwave heating apparatus of FIG. B-B 'sectional view of the microwave heating apparatus of FIG. The figure for demonstrating the temperature detection by the infrared sensor of the microwave heating apparatus of FIG. The flowchart for demonstrating the warming process by the heating only of the microwave of the microwave heating apparatus of FIG. The flowchart for demonstrating the warming process by the heating only of the microwave of the microwave heating apparatus of FIG. The flowchart for demonstrating the warming process by the simultaneous heating of the microwave and steam of the microwave heating apparatus of FIG. The flowchart for demonstrating the warming process by the simultaneous heating of the microwave and steam of the microwave heating apparatus of FIG.

Explanation of symbols

31 Microwave heating device 32 Magnetron (microwave generation means)
33 Waveguide 34 Heating chamber 35 Mounting table 36 Heated object storage space 37 Antenna space 38, 39 Rotating antenna 40, 41 Motor (driving means)
42 Heating chamber bottom surface 43, 44 Coupling hole 45, 46 Coupling part 47, 48 Radiation part 53, 54 Bending part 55, 56, 57, 58 End part 59 Infrared sensor (temperature detection means)
60 Control part (control means)
61 Memory 62 Setting part 63 Door

Claims (2)

Microwave generation means;
A waveguide for transmitting microwaves from the microwave generating means;
A heating chamber connected to the waveguide;
A mounting table disposed in the heating chamber for mounting an object to be heated;
A heated object storage space formed above the mounting table in the heating chamber;
Temperature detecting means for detecting the temperature in the heating chamber;
An antenna space formed below the mounting table in the heating chamber;
A plurality of rotating antennas having radiation directivities disposed in the antenna space from the waveguide for radiating microwaves in the waveguide into the heating chamber;
Control means for controlling drive means for rotationally driving each of the plurality of rotating antennas ,
The control means swings the temperature detection means to acquire temperature data at a predetermined number of measurement points, and a uniform heating by rotating the plurality of rotating antennas and a radiation directivity of the plurality of rotating antennas are strong. And selectively using centralized heating to direct a predetermined portion of the object to be heated,
The plurality of objects to be heated are placed on the mounting table, and the control means takes in temperature data of the objects to be heated from the temperature detection means at the start of heating, and detects the plurality of the detected objects based on the temperature data When one of the objects to be heated is a frozen food, if the amount of the frozen food is large, the heating time of the frozen food is set longer than that when the amount of the frozen food is small. Wave heating device.   The temperature detection means detects the temperature in the heating chamber at a plurality of points, and the control means determines the amount of the object to be heated based on the number of points detected by the temperature detection means. A microwave heating apparatus according to 1.

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