JP4306005B2 - High frequency heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a high-frequency heating device that dielectrically heats an object to be heated using microwave energy, and more particularly to a device that selectively heats an interface of a microwave space to change impedance.
[0002]
[Prior art]
  The microwave space of the conventional high-frequency heating device is mainly intended to make the heating of the object to be heated contained in the microwave space uniform. An object rotation method, a multiple power feeding method, or a concave-convex shape of a wall surface of a microwave space has been put into practical use.
[0003]
  On the other hand, as a prior art for selectively heating a specific region, there is JP-A-8-153578 using the above-described multiple power feeding method. This publication is provided with a plurality of microwave power feeding parts to a microwave space, and the electric field strength in the central part of the microwave space is increased by microwave radiation from one power feeding part to strongly heat the central part of the object to be heated. However, it discloses that the peripheral portion of the object to be heated is strongly heated by the microwave radiation from the other power feeding portion. And the switching means which switches the microwave radiation from these two electric power feeding parts is provided.
[0004]
  Japanese Patent Laid-Open No. 8-330066 discloses that the excitation mode in the microwave space is selectively switched by changing the direction of the current induced on the metal wall surface forming the boundary surface of the microwave space. Yes.
[0005]
[Problems to be solved by the invention]
  However, the conventional technology for selectively heating a specific region is to achieve the microwave flow in the microwave space by switching the microwave radiation position to the microwave space containing the object to be heated. It does not change.
[0006]
  The flow of microwaves in the microwave space is affected by the shape of the microwave space and the shape and amount of the object to be heated stored in the microwave space, or the placing plate on which the object to be heated is placed. In order to control the flow of microwaves in the wave space, it is necessary to have a function of directly acting on the microwaves existing in the microwave space and changing the action contents with time.
[0007]
  In the above prior art, the direct action on the microwave existing in the microwave space is the shape and amount of the object to be heated, and the temporal change factor is the object to be heated accompanying the temperature rise of the object to be heated. Therefore, it is difficult to control the flow of the microwave as desired because the physical space of the object or the space area occupied by the object to be heated is changed. Therefore, it is difficult to concentrate the microwaves in a specific area of the microwave space.
[0008]
  On the other hand, the technology for changing the direction of the current induced on the metal wall that forms the boundary surface of the microwave space directly affects the microwave in the microwave space, so that the flow of the microwave in the space can be changed. It is possible. However, this prior art is intended to make the heating of the object to be heated uniform by changing the excitation mode in the microwave space. For example, this technique is effective for a microwave space in which only one excitation mode can occur. I can not expect. Further, in a microwave space where a plurality of excitation modes are generated, it is difficult to say that the excitation mode can be quickly varied with respect to the short-time heat treatment that is a feature of the high-frequency heating device. Furthermore, it is the structure which rotates the opening provided in the metal wall surface, and there exists a danger of producing the spark accompanying rotation control in the environment where the microwave is supplied in the microwave space.
[0009]
  The present invention variably controls the heating region of the object to be heated by changing the impedance of the boundary surface forming the microwave space to control the flow of the microwave in the microwave space as desired. The present invention provides a high-frequency heating device that heats a desired specific region or uniformizes heating of the entire object to be heated.
[0010]
[Means for Solving the Problems]
  In order to solve the above problems, the high-frequency heating device of the present invention providesA microwave space for containing the object to be heated and substantially confining the supplied microwave; an opening provided to divide a flow of a high-frequency current generated in a metal wall surface forming the microwave space; Impedance variable means for changing the impedance of the opening, a heating area selection input section for selecting and specifying the heating area of the object to be heated, and the impedance variable means for driving the impedance variable means based on an input signal of the heating area selection input section A control unit that controls the impedance of the opening, and the impedance variable means includes a groove connected to the opening and closed at the end, and a low dielectric loss material rotatably supported in the groove. A dielectric plate and a dielectric plate rotation driving means for rotating the dielectric plate, and the control unit corresponds to a signal of the heating region selection input unit. Wherein a dielectric plate intended for variably controlling continuously or defines a predetermined angle.
[0011]
  Create a microwave spaceMetal wallConfines microwaves in space, andMetal wallLet ’s propagate in spaceMetal wallIs reflected in space with a phase difference of 180 °.Metal wallBy changing the impedance of theMetal wallThen, the phase difference between the incident wave and the reflected wave of the microwave can be changed.Metal wallIn this case, as described above, the phase difference between the incident wave and the reflected wave is 180 °,Metal wallIs ideally infinite, the phase difference between the incident wave and the reflected wave becomes zero. Inside the microwave spaceMetal wallMicrowave propagating toMetal wallPredetermined standing waves are generated by the microwaves reflected at.
[0012]
  Then, the standing wave distribution of the microwave in the microwave space is changed by changing the phase difference between the incident wave and the reflected wave by changing the impedance of the opening provided in the metal wall surface. The standing wave distribution of the microwave in the microwave space is defined by setting the impedance of the aperture to a specified value. Therefore, by setting the impedance of the aperture to a desired value corresponding to the input signal of the heating area selection input unitBy changing the standing wave distribution of the microwave in the microwave space to a desired distribution, the microwave can be concentrated on a specified region of the object to be heated and the region can be heated strongly.
[0013]
  And with respect to the opening part of a specific shape, the impedance value of the opening part can be prescribed | regulated by the rotation support angle of the dielectric material board provided in the groove part. Thus, the impedance variable means is a dielectric material, and the impedance can be variably controlled without generating a spark even while the microwave is being supplied into the microwave space. It is possible to carry out fine impedance variable control, that is, variable control of the standing wave distribution of the microwave, during the progress.
[0014]
  In addition, by continuously varying the support angle of the dielectric plate, the impedance of the aperture is continuously varied, and the standing wave distribution of the microwave in the microwave space is continuously varied in time to be heated. The generation of heat spots on the object can be eliminated and the uniform heating of the entire object to be heated can be promoted.
[0015]
  And by providing the input part which selects and designates the heating area | region of this to-be-heated material, since a user can select and designate a heating area himself, a highly convenient apparatus can be provided.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
  The high-frequency heating device according to claim 1 of the present invention includes:A microwave space for containing the object to be heated and substantially confining the supplied microwave; an opening provided to divide a flow of a high-frequency current generated in a metal wall surface forming the microwave space; Impedance variable means for changing the impedance of the opening, a heating area selection input section for selecting and specifying the heating area of the object to be heated, and the impedance variable means for driving the impedance variable means based on an input signal of the heating area selection input section A control unit that controls the impedance of the opening, and the impedance variable means includes a groove connected to the opening and closed at the end, and a low dielectric loss material rotatably supported in the groove. A dielectric plate and a dielectric plate rotation driving means for rotating the dielectric plate, and the control unit corresponds to a signal of the heating region selection input unit. Wherein a dielectric plate intended for variably controlling continuously or defines a predetermined angle.
[0017]
  And in the microwave spaceMetal wallBy defining the impedance, the standing wave distribution of the microwave generated in the microwave space is defined.In addition, by continuously varying the support angle of the dielectric plate, the impedance of the aperture is continuously varied, and the standing wave distribution of the microwave in the microwave space is continuously varied in time to be heated. The generation of heat spots on the object can be eliminated and the uniform heating of the entire object to be heated can be promoted.
Thereby, when the user selects a desired heating item from the heating area selection input unitOpening of metal wallIs set to an impedance value corresponding to the selected heating item, and a desired region of the object to be heated can be heated.
[0018]
  The high-frequency heating device according to claim 2 of the present invention is based on the input signal of the heating region selection input section.To the heated object corresponding to the heating area of the heated objectDisplay means for displaying the flow of the microwave is provided. Thereby, the user can easily confirm the heating content of the selected heating item, can recognize the consistency between the heating state after heating and the selected heating item, and can provide a user-friendly device.
[0019]
  The present inventionClaim 3The high-frequency heating apparatus includes a mounting tray on which an object to be heated is mounted and a mounting tray rotation driving unit that rotationally drives the mounting tray.
[0020]
  Then, by superimposing the rotation of the object to be heated on the variable control of the microwave standing wave in the microwave space, the object to be heated can be irradiated with microwaves with finely dispersed energy. Concentric heating or uniform heating of the entire object to be heated can be effectively performed.
[0021]
  The present inventionClaim 4In the high-frequency heating apparatus, the heating area selection input unit heats at least the center of the object to be heated stored in the center part of the microwave space as a heating item for selecting and specifying the heating area of the object to be heated; A peripheral heating mode for heating the periphery of the object to be heated.
[0022]
  In this way, by providing a heating item with the central part in the microwave space as a heating area and a heating item with the peripheral part as a heating area, the central part and the peripheral part are heated in the object to be heated in various shapes. Can be specified in the area.
[0023]
  The present inventionClaim 5The high-frequency heating deviceThe heating area selection input unit is a central heating mode for heating at least the center of the object to be heated stored in the central part of the microwave space as an input key for selecting and specifying the heating area of the object to be heated, and the periphery of the object to be heated A peripheral heating mode for heating theThe control unit is characterized in that when at least the peripheral heating mode is selected, the mounting table rotation driving means is controlled to a non-operating state based on the input signal.
[0024]
  By using such a control method, different types of food can be selectively heated. For example, in the case of curry and rice, the temperature of rice is usually high, and the curry is heated only at the periphery, making it difficult to raise the center temperature. By selecting the created space as the heating region, it is possible to concentrate microwaves on the curry and increase the temperature of the curry. At this time, the rice is heated to a sufficient temperature (about 80 ° C.) by the microwave reflected on the surface of the curry.
[0025]
  The present inventionClaim 6In the high frequency heating apparatus, the heating area selection input unit selects and designates the heating area of the object to be heatedInput keyAnd having a whole heating mode for selecting the entire object to be heated as a heating region, and the control unit continuously and variably controls the impedance of the opening portion based on an input signal when the whole heating mode is selected. It is characterized by that.
[0026]
  The high-frequency heating apparatus according to claim 7 of the present invention has an overall heating mode in which the heating area selection input unit selects the entire object to be heated as the heating area as an input key for selecting and specifying the heating area of the object to be heated. The control unit continuously variably controls the impedance of the opening portion based on an input signal when the overall heating mode is selected, or continuously variably controls the impedance of the opening portion. The table rotation driving means is controlled to be in an operating state.
[0027]
  In this way, by continuously and variably controlling the impedance of the opening, the standing wave distribution of the microwave in the microwave space is changed temporally and continuously, and the entire heating of the object to be heated is promoted. be able to. Moreover, only the peripheral part of a to-be-heated object or only the center part of a to-be-heated object can be heated by rotating a to-be-heated object in the state which set the opening part to the specific impedance value. Furthermore, the entire object to be heated can be more uniformly heated by simultaneously changing the impedance and rotating the object to be heated. Such a control method can greatly contribute to the suppression of the temperature difference in the vertical direction in warming milk and sake.
[0028]
  The present inventionClaim 8In the high-frequency heating apparatus, the control unit drives the impedance variable means based on the input signal of the heating region selection input section to control the impedance of the opening portion to a specified value, and the impedance variable means within the heating time of the object to be heated. And the impedance value is varied up and down around the specified impedance value.
[0029]
  In this way, by raising or lowering the impedance value around the impedance value with respect to the specified impedance value, a margin can be given to the placement position of the object to be heated in the microwave space.
[0030]
  The present inventionClaim 9The high-frequency heating device has a function of detecting and determining the support angle of the dielectric plateRotation control of dielectric plate to a predetermined anglehave.
[0031]
  Thus, by providing the function of detecting the support angle of the dielectric plate, the impedance value of the aperture based on the heating region selection input signal can be defined with good reproducibility.
[0032]
  The present inventionClaim 10This high frequency heating apparatus is characterized in that the support angle is determined based on a microwave signal in the groove.
[0033]
  In this way, it is possible to monitor changes in the characteristics of the groove portion including the dielectric plate by determining the support angle based on the microwave signal in the groove portion, and to eliminate the need for a separate dedicated angle detection means.
[0034]
【Example】
  Embodiments of the present invention will be described below with reference to the drawings.
[0035]
  Example 1
  FIG. 1 is a configuration diagram of a high-frequency heating apparatus showing Embodiment 1 of the present invention, FIG. 2 is a cross-sectional configuration diagram of a principal part of FIG. 1, and FIG. 3 is a configuration diagram of impedance variable means of FIG.
[0036]
  In FIG. 1 and FIG. 2, a microwave space 10 is a microwave boundary in which a right wall 11, a left wall 12, a back wall 13, an upper wall 14, a bottom wall 15, and an object to be heated are metal boundaries. The front opening / closing wall surface 16 which is an opening / closing wall surface to be taken in and out 10 has a substantially rectangular parallelepiped shape, and is formed so as to substantially confine the fed microwave. Reference numeral 17 denotes a magnetron that generates a microwave to be fed to the microwave space 10, reference numeral 18 denotes a waveguide that guides the microwave generated by the magnetron 17 to the microwave space 10, and reference numeral 19 denotes a microwave that connects the microwave space 10 and the waveguide 18 to each other. It is a power supply port that couples in a wave and radiates the microwave generated by the magnetron 17 into the microwave space 10.
[0037]
  Reference numeral 20 denotes an opening formed in the left wall surface 12, which has a substantially rectangular hole shape. Reference numeral 21 denotes impedance variable means, which is formed spatially continuously with the opening 20. The impedance varying means 21 is provided outside the microwave space 10, and a dielectric plate 24 is provided inside a groove portion 23 formed by a groove plate 22 made of a metal material that covers the opening 20 and the left wall surface 12. It is configured. The groove portion 23 has a predetermined groove depth dimension L1 and a shape having a groove height dimension L2 substantially equal to the opening dimension H1 of the opening section 20. The end of the groove 23 is configured to substantially close the microwave by the groove plate 22. The dielectric plate 24 constituting the impedance varying means 21 is configured to rotate and includes a rotation driving means (shown in FIG. 3 described later).
[0038]
  Reference numeral 25 denotes an operation unit provided on the front surface of the apparatus main body. In the operation unit 25, a heating area selection input unit 26 for selecting a heating area of the object to be heated and a microwave flow to the object to be heated are displayed. Display means 27 is provided. The heating area selection input unit 26 is a heating item “left” key that uses the left side of the object to be heated as the heating area when viewed from the front of the apparatus with respect to the object to be heated and stored in the microwave space 10. The heating item “center” key having the heating area as the center, the heating item “right” key having the heating area as the right side, and the heating item “entire” key for heating the entire object to be heated are arranged. In addition, the display means 27 can display the display contents in which the pattern of the object to be heated is arranged in the center of the display means and the state in which the microwave is propagated from the left and right and the upper side with respect to the object to be heated is displayed. I have to. The display means shown in FIG. 1 and FIG. 2 shows the case where “center” is selected and input as a heating item, and the arrow indicating the propagation of the microwave shows that the upward direction is displayed. In addition, the arrow shown with the broken line on either side is shown in order to demonstrate the display content, and is not displayed in an actual use environment.
[0039]
  Reference numeral 28 denotes an inverter drive power supply unit that drives the magnetron 17, and 29 denotes a control unit that controls the operation of the entire apparatus. Reference numeral 30 denotes a microwave sensor coupled to the microwave in the groove 23, and a signal detected by the microwave sensor 30 is input to the control unit 29. The control unit 29 controls the operation of the inverter drive power supply unit 28 and the operation of the rotation driving means for rotating the dielectric plate 24 based on the heating information input from the operation unit 25 and the signal from the microwave sensor 30. Then, the object to be heated stored in the microwave space 10 is heated by microwaves.
[0040]
  Reference numeral 31 denotes a mounting tray on which an object to be heated is placed, 32 is a see-through window having a punching hole configuration disposed substantially at the center of the front opening / closing wall surface 16 and allowing the inside of the microwave space 10 to be seen through; This is a door latch switch that determines the completed state.
[0041]
  Next, the detailed configuration of the impedance variable means will be described with reference to FIG. The dielectric plate 24 provided in the groove portion 23 has a plate-like structure made of a low dielectric loss material, and support portions 34 and 35 for penetrating holes provided in the wall surface of the groove plate 22 are provided at both ends thereof. The dielectric plate 24 is supported on the wall surface of the groove plate 22 by the support portions 34 and 35. Reference numeral 36 denotes a stepping motor (rotation drive means) that rotationally drives the dielectric plate 24, and its output shaft is connected to the support portion 35 of the dielectric plate 24. Reference numeral 37 denotes a motor fixing plate for assembling and fixing the stepping motor 36.
[0042]
  The microwave sensor 30 includes an antenna 38 coupled to the microwave in the groove 23, a detection diode 39 for detecting a detection signal of the antenna 38, and a matching element 40 provided at the output of the detection diode 39. The antenna 38, the detection diode 39, and the matching element 40 have a circuit configuration using a microstrip line, and the output signal is transmitted to the control unit 29 via the coaxial cable 41.
[0043]
  Reference numeral 42 denotes a screw for assembling the unit of the microwave sensor 30 to the groove plate 22.
[0044]
  The operation and operation of the high-frequency heating device of the present invention having the above configuration will be described below. FIG. 4 shows the characteristics of the phase difference generated between the incident wave and the reflected wave in the opening portion with respect to the support angle of the dielectric plate 24.
[0045]
  In FIG. 4, the groove configuration dimensions are L1 = 40 mm, L2 = 30 mm, H1 = 30 mm, the groove width dimension is 80 mm, the dielectric plate 24 has a relative permittivity of 12.3 and a plate thickness of 6.2 mm. Shows an example of characteristics when is disposed in the center in the depth direction of the groove. The support angle of the dielectric plate 24 is rotated by one step 9 ° by the stepping motor 36. The support angle θ of the dielectric plate 24 is a state in which the dielectric plate 24 is parallel to the opening 20 as a reference angle, and the dielectric plate 24 is perpendicular to the opening 20 as illustrated. Is shown as 90 °.
[0046]
  From the characteristics shown in FIG. 4, when the support angle of the dielectric plate 24 is near 0 ° or near 180 °, the phase difference between the incident wave and the reflected wave is 180 °, and the opening 20 is the same as the metal wall surface. Has the effect of. On the other hand, when the support angle of the dielectric plate 24 is near 90 °, the phase difference between the incident wave and the reflected wave is substantially zero. Thus, by changing the support angle of the dielectric plate 24, the phase difference between the incident wave and the reflected wave of the microwave in the opening 20 can be changed. This change in the phase difference changes the standing wave distribution of the microwave in the microwave space 10. By changing the phase difference between the incident wave and the reflected wave as described above, variable control of the heating region of the object to be heated, which will be described later, is realized.
[0047]
  By using this phase difference variable control, it is possible to provide an apparatus that enables a user to designate a desired heating region in high-frequency heating of an object to be heated. Further, the standing wave distribution can be quickly changed without generating a spark even during microwave heating by a simple configuration in which the dielectric plate is rotated, and fine heating control can be performed as the heating progresses.
[0048]
  Next, an embodiment of a method for determining the support angle of the dielectric plate 24 will be described with reference to FIG. The high-frequency heating device of the present invention uses the detection signal of the microwave sensor 30 to determine the support angle of the dielectric plate 24.
[0049]
  FIG. 5 shows a relative value characteristic of the microwave signal with respect to the support angle of the dielectric plate 24 when the support angle is expressed according to the support angle described in FIG. The support angle of −45 ° that is closest to the microwave sensor 30 has the characteristics shown in the figure, with the maximum electric field strength of the microwave existing in the gap formed by the groove plate 22 and the dielectric plate 24. That is, the control unit 29 can determine that the maximum value of the signal detected by the microwave sensor 30 when the dielectric plate 24 is rotated once is that the support angle of the dielectric plate 24 is near −45 °.
[0050]
  The support angle determination of the dielectric plate 24 based on the microwave signal in the groove portion can monitor changes in the characteristics of the entire groove portion including the dielectric plate 24, can perform abnormality determination processing, and additionally has a dedicated angle detection means. This can be eliminated, and the additional factors of cost increase and reliability assurance of the detection means can be eliminated.
[0051]
  A practical practical embodiment will be described below based on the basic function possessed by the high-frequency heating device of the present invention described above.
[0052]
  FIG. 6 is an enlarged view of the operation unit 25 shown in FIGS. 1 and 2. The operation unit 25 includes “Left”, “Center”, “Right”, and “Whole” input keys as heating items 26 for selecting and specifying the heating area of the object to be heated. Moreover, the display means 27 which displayed the flow of the microwave to a to-be-heated material corresponding to each heating item is provided. This display content changes the display content corresponding to each heating item. An object to be heated is arranged in the center of the display means 27, and the flow of the microwave in the microwave space is displayed with an arrow for the object to be heated. The illustrated display content is a case where “center” is selected and input as a heating item. In this case, only arrows indicated by solid lines in the figure are displayed as arrows indicating the flow of microwaves. The arrows indicated by broken lines in the figure indicate the contents that can be displayed when another heating item is selected.
[0053]
  Examples of the definition of the support angle of the dielectric plate 24 for each heating item are: “Left” is 0 °, “Center” is 45 °, “Right” is 90 °, and “Whole” is a predetermined speed. It is a continuous rotation at.
[0054]
  By displaying the microwave flow in the microwave space, the user can easily confirm the contents of the selected heating item and can recognize the consistency between the heating state after heating and the selected heating item. It can be a good device.
[0055]
  The operation procedure and control contents when using this apparatus will be described with reference to FIG. After the object to be heated is stored in the microwave space, the user determines a heating area for heating the object to be heated and selects one of the heating items described above (S101). Next, after inputting the heating time (S102), the microwave heating of the object to be heated is started by pressing the “start” key shown in FIG. 6 (S103).
[0056]
  Based on the above input information, the control unit 29 operates the stepping motor 36 that is a rotation driving means of the dielectric plate 24 to set the dielectric plate 24 at a desired support angle or to continuously rotate it. When the dielectric plate 24 is set to a desired support angle, the dielectric plate 24 is rotated stepwise to detect the position of the support angle 315 ° (or −45 °), and then the dielectric plate is set to the desired support angle. Set (S104). In S <b> 105, the operation of the inverter drive power supply 29 is started to generate a microwave from the magnetron 17.
[0057]
  In S106, the heating state of the object to be heated is monitored. When the heating end determination in S107 is “Yes”, it is determined that the heating is ended. In S108, the operation of the inverter drive power supply unit 29 is stopped, and the dielectric plate 24 is rotated in S109. The energization of the stepping motor 36 for driving control is stopped to complete microwave heating of the object to be heated.
[0058]
  The contents of the monitoring of the heating state from S106 to S107 and the end determination based thereon are the information on the heating time input from the operation unit 25, the detection signal of the microwave sensor 30, or the temperature information (not shown) of the object to be heated, It is executed by collating or comparing end-to-end information based on sensor information (not shown) for detecting gas or water vapor generated by the object to be heated with an end determination criterion.
[0059]
  In addition, control content S110, S111 enclosed with the broken line in FIG. 7 is the control content applied with respect to the apparatus provided with the drive means which rotationally drives the mounting tray which mounts the to-be-heated material mentioned later. .
[0060]
  Next, FIG. 8 shows an example of heating distribution in a microwave space configuration without a rotation driving system for the placing plate on which the object to be heated shown in FIG. 1 is placed. FIG. 8 shows a heating distribution using Adhair Glue (registered trademark) 200 g manufactured by Sekisui Resin Co., Ltd. The microwave space 10 has a width of 310 mm, a depth of 310 mm, and a height of 215 mm, and a bottom area of a container containing Adhair synthetic glue (registered trademark) is 100 square mm.
[0061]
  In addition, Adhair synthetic glue (registered trademark) is a polyvinyl alcohol aqueous solution, which is transparent at normal temperature, but has a property of becoming cloudy when the temperature is 45 ° C. or higher.
[0062]
  The microwave output is 500 W and shows the heating distribution after heating for 40 seconds, and the white area is the heated area. The white area, that is, the heating area can be changed by changing the support angle of the dielectric plate 24.sowear. The support angle of the dielectric plate 24 with respect to the heating item for selecting the heating area arranged in the operation unit 25 is 0 ° for “left”, 45 ° for “center”, and 90 ° for “right”. I will let you.
[0063]
  As described above, by providing the “center” heating item with the central portion in the microwave space as the heating region and the “left” and “right” heating items with the peripheral portion as the heating region, various shapes or arrangements of covered items are provided. It is possible to provide an apparatus capable of freely designating the central portion and the peripheral portion of the heated object as a heating region and performing optimum heating or user preference according to the object to be heated.
[0064]
  As is well known, Adhair paste has a larger dielectric loss and a smaller penetration depth than water. In the case of an ad hair paste load, the “center” heating item is illustrated data in which the center portion is not sufficiently heated. However, in a normal food, the “center” heating item can be used to achieve center heating.
[0065]
  Next, an example of the actual cooking menu will be described with reference to FIG. FIG. 9 shows a temperature distribution when curry rice (both at room temperature: about 20 ° C.) is microwave heated. Curry is on the right side of the figure. The temperature distribution (a) is when the “right” heating item of the apparatus of the present invention is used, while the temperature distribution (b) is when the conventional mounting plate rotation drive type high frequency heating apparatus is used. The heating content is 500 W for 2 minutes and 30 seconds.
[0066]
  Moreover, in foodstuffs such as curry and rice, the manner in which curry is arranged varies, and further, the serving dish is not always placed at the center of the microwave space. An improved control method for enabling the heating region control of the present invention to be used effectively even in such an actual use environment will be described.
[0067]
  This control method is to vibrate within a range of, for example, ± 9 ° (corresponding to one step of the stepping motor) around the angle that defines the support angle of the dielectric plate 24. As a result, the impedance of the aperture varies with a vertical width value centered on the specified impedance value, so that the heating region in the microwave space can be swung left and right. By using this control method, the placement position of the object to be heated in the microwave space can be given a margin, and the user can provide a device that further enhances convenience without strictly limiting the placement location. it can.
[0068]
  As described above, the control method of changing the standing wave distribution of the microwave in the microwave space 10 by changing the impedance of the opening 20 can selectively heat different kinds of foods to appropriate temperatures, and is achieved by the conventional technique. New cooking software that cannot be provided.
[0069]
  FIG. 9 shows an example when different materials are heated. FIG. 9A shows a case where rice is placed on a plate and curled on one side (shaded area in the drawing). In FIG. 9C heated by the conventional apparatus, the curry is hardly heated, and the rice is heated to a temperature range (black area in the figure) exceeding the upper limit temperature of 80 ° C., which is said to be delicious. On the other hand, in FIG.9 (b) heated with the apparatus of this invention, the temperature of rice is a maximum of 80 degreeC, and the curry is also heated to about 60 degreeC. Therefore, a delicious meal can be eaten immediately after the end of heating.
[0070]
  (Example 2)
  FIG. 10 is a configuration diagram of a high-frequency heating device showing Embodiment 2 of the present invention, and FIG. 11 is a cross-sectional configuration diagram of FIG. In the figure, members that are the same as or equivalent to those in the first embodiment are denoted by the same reference numerals.
[0071]
  The difference between the second embodiment and the first embodiment is that a loading tray driving means 44 that rotationally drives a loading tray 43 on which an object to be heated is loaded is added. Reference numeral 45 denotes a rotation support unit that rotates and supports the mounting tray 43, and 46 denotes a weight sensor that measures the weight of the object to be heated. The detected signal is input to the control unit 29.
[0072]
  The microwave space 47 is configured to generate two excitation modes, and is perpendicular to the flow direction of the high-frequency current induced on the metal wall surface forming the boundary surface of the microwave space 47 with respect to one excitation mode. The longitudinal dimension of the opening 20 is arranged.
[0073]
  The operation unit 48 is provided with a heating region selection input unit 49 and display means 50 for displaying the flow of microwaves in the microwave space 47. The display means 50 is provided with an arrow indicating the flow of microwaves from below the object to be heated as compared with the first embodiment.
[0074]
  The impedance varying means 21 that varies the impedance of the opening 20 has the same configuration and operation as in the first embodiment.
[0075]
  FIG. 12 shows a heating distribution example of the high-frequency heating device according to the second embodiment of the present invention having such a configuration. The microwave space 47 has a width of 300 mm, a depth of 320 mm, and a height of 215 mm. The height of the mounting tray 43 from the bottom surface of the microwave space 47 is about 27 mm. The load is the same as in FIG.
[0076]
  For the heating item, the “overall” key was selected, and the rotational speed of the dielectric plate 24 was 15 revolutions per minute. The heating distribution (a) indicates a case where the mounting tray 44 is stopped, and the heating distribution (b) indicates a case where the mounting tray 44 is rotated six times per minute.
[0077]
  The microwave space 47 of the second embodiment has an excitation mode <332> in the microwave space 47 according to the above-described shape and dimension (the numerical values are peaks of standing waves generated in the width method, the depth direction, and the height direction, respectively). (The same expression is used hereinafter) and the excitation mode <412> can be generated. And the opening part 20 is arrange | positioned so that the flow of the high frequency current induced | guided | derived on the metal wall surface corresponding to excitation mode <332> may be interrupted. When the impedance of the opening 20 is increased, the excitation mode <332> is broken and the excitation mode <412> is strengthened. This excitation mode <412> is an excitation mode in which microwaves are concentrated at the center of the mounting plate in the microwave space 47.
[0078]
  By continuously rotating only the dielectric plate 24, <332>, <332> collapse, <412>, <412> collapse, and all excitation modes collapse are formed in the microwave space 47. Can do. Thereby, a heating distribution as shown to Fig.12 (a) can be produced. On the other hand, when the rotation of the mounting plate 43 is superimposed on the continuous rotation of the dielectric plate 24, the entire area around the object to be heated can be heated as shown in FIG.
[0079]
  In this manner, the object to be heated is concentrically heated by supporting the dielectric plate 24 at a predetermined angle or by combining continuous rotation with the presence or absence of rotation of the mounting tray, or only the peripheral part is heated. It is possible to provide an apparatus with greatly improved convenience that can promote uniform heating throughout.
[0080]
  If a control method in which only the dielectric plate 24 is continuously rotated is used, the central portion of the object to be heated can be heated as strongly as the peripheral portion. Therefore, it is effective for cooking with a small microwave penetration depth, such as hamburger, stew, and steamed tea.
[0081]
  On the other hand, a more effective control method will be described below for the control method for superimposing the rotation of the mounting tray 43. FIG. 13 shows the temperature difference in the vertical direction after heating at 200 cc of water and an initial temperature of 7 ± 2 ° C. with a microwave output of 500 W for 1 minute and 30 seconds using the rotational speed of the dielectric plate 24 as a parameter. . As the container, a cylindrical container having a diameter of 72 mm corresponding to a mug was used.
[0082]
  From the characteristics shown in FIG. 13, it is recognized that uniform heating can be promoted by increasing the rotational speed of the dielectric plate 24. Thus, the control method of rotating the dielectric plate 24 at a high speed can promote the dispersion of the microwaves in the vertical direction in the microwave space, and makes the heating of the heated object bulky with respect to the bottom area uniform. It is effective for. For example, milk warming, sake canning, coffee warming and the like can be optimally heated.
[0083]
  In the above description, the stepping motor is used as the rotational driving means for the dielectric plate 24, and the above-described various dielectric plates can be easily controlled and various cooking methods can be provided. It is clear that even a rotational drive specification specialized for high-speed rotation using this motor can provide a device having a sufficient advantage over the conventional device.
[0084]
  In addition, the material of the dielectric plate is basically a low dielectric loss material, and glass, ceramics, or resin can be used. In order to make the impedance variable means compact and to increase the phase difference, the relative dielectric of the material is used. The rate is preferably at least 7 or more.
[0085]
【The invention's effect】
  As described above, the present invention has the following effects.
[0086]
  (1) According to the high-frequency heating device of claim 1,Impedance variable means for changing the impedance of the opening provided to divide the flow of high-frequency current generated on the metal wall forming the microwave space for storing the object to be heated, and heating for selecting and specifying the heating area of the object to be heated An area selection input section; and a control section that drives the impedance variable means based on an input signal of the heating area selection input section and controls the impedance of the aperture. The impedance variable means is connected to the aperture. A groove portion whose end is closed, a dielectric plate made of a low dielectric loss material rotatably supported in the groove portion, and a dielectric plate rotation driving means for driving the dielectric plate to rotate. The dielectric plate is regulated at a predetermined angle or continuously variably controlled according to the signal of the area selection input unit.ByBy defining the impedance of the metal wall in the microwave space, the standing wave distribution of the microwave generated in the microwave space is defined. In addition, by continuously varying the support angle of the dielectric plate, the impedance of the aperture is continuously varied, and the standing wave distribution of the microwave in the microwave space is continuously varied in time to be heated. The generation of heat spots on the object can be eliminated and the uniform heating of the entire object to be heated can be promoted.
[0087]
  thisThus, the user can select a desired heating item from the heating area selection input unit and perform heating as desired by the user.
[0088]
  (2) According to the high frequency heating device of the second aspect, based on the input signal of the heating region selection input section.To the heated object corresponding to the heating area of the heated objectBy providing a display means for displaying the flow of the microwave, the user can easily confirm the heating content of the selected heating item and can recognize the consistency between the heating state after heating and the selected heating item, which is easy to use. A good device can be provided.
[0089]
  (3Claim3According to the high frequency heating apparatus of the present invention, by providing the mounting tray on which the object to be heated is mounted and the mounting tray rotation driving means for rotationally driving the mounting tray, the microwaves in the microwave space By superimposing the rotation of the object to be heated on the variable control of the wave, the object to be heated can be irradiated with microwaves with finely dispersed energy, and the object to be heated is concentrically heated or the entire object to be heated is made uniform. Can be performed effectively.
[0090]
  (4Claim4According to the high frequency heating apparatus, the heating area selection input unit selects and designates the heating area of the object to be heated.Input keyAs a center heating mode for heating at least the center of the object to be heated stored in the center of the microwave space and a peripheral heating mode for heating the periphery of the object to be heated. In the object, the central part and the peripheral part can be designated as the heating region.
[0091]
  (5Claim5According to the high-frequency heating device ofThe heating area selection input unit is a central heating mode for heating at least the center of the object to be heated stored in the central part of the microwave space as an input key for selecting and specifying the heating area of the object to be heated, and the periphery of the object to be heated A peripheral heating mode for heating theThe control unitSmallAt least when the peripheral heating mode is selected, the table rotation driving means is controlled to be in a non-operating state based on the input signal, so that different kinds of food can be selectively heated. For example, in the case of curry and rice, the temperature of rice is usually high, and the curry is heated only at the periphery, making it difficult to raise the center temperature. By selecting the created space as the heating region, it is possible to concentrate microwaves on the curry and increase the temperature of the curry.
[0092]
  (6Claim6According to the high frequency heating apparatus, the heating area selection input unit selects and designates the heating area of the object to be heated.Input keyAs a heating area for selecting the whole object to be heated as a heating area, and the control unit continuously variably controls the impedance of the opening portion based on an input signal when the whole heating mode is selected.It is characterized by doing.
[0093]
  (7) According to the high-frequency heating device of claim 7, the heating area selection input unit selects the entire heating mode as the heating area as an input key for selecting and specifying the heating area of the heating object. And the control unit continuously variably controls the impedance of the aperture or continuously variably controls the impedance of the aperture based on an input signal when the overall heating mode is selected. And the above-mentioned plate rotation drive means is controlled to an operation state, It is characterized by the above-mentioned.
[0094]
  theseBy continuously and variably controlling the impedance of the aperture, the standing wave distribution of the microwave in the microwave space can be changed temporally and continuously, and the entire heating of the object to be heated can be promoted. it can. Moreover, only the peripheral part of a to-be-heated object or only the center part of a to-be-heated object can be heated by rotating a to-be-heated object in the state which set the opening part to the specific impedance value. Furthermore, the entire object to be heated can be more uniformly heated by simultaneously changing the impedance and rotating the object to be heated. Such a control method can greatly contribute to the suppression of the temperature difference in the vertical direction in warming milk and sake.
[0095]
  (8Claim8According to the high-frequency heating apparatus, the control unit drives the impedance variable means based on the input signal of the heating region selection input unit to control the impedance of the opening portion to a specified value and the impedance within the heating time of the object to be heated. By driving the variable means to vary the impedance value up and down around the specified impedance value, it is possible to give a margin to the placement position of the object to be heated in the microwave space. it can.
[0096]
  (9Claim9According to the high-frequency heating device, the function of detecting and determining the support angle of the dielectric plateRotation control of the dielectric plate to a predetermined angleSince the impedance value of the opening portion based on the heating region selection input signal can be defined with good reproducibility.
[0097]
  (10Claim10According to the high frequency heating apparatus of the present invention, the support angle is determined based on the microwave signal in the groove portion, so that it is possible to monitor the change in the characteristics of the groove portion including the dielectric plate and to provide a dedicated angle detection means. Can be made unnecessary.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a high-frequency heating device showing Embodiment 1 of the present invention.
FIG. 2 is a cross-sectional configuration diagram of the high-frequency heating device of FIG.
3 is a configuration diagram of impedance variable means of the high-frequency heating device of FIG.
FIG. 4 is a phase difference characteristic diagram of impedance variable means showing one embodiment of the present invention.
FIG. 5 is a detection signal characteristic diagram of a microwave sensor showing one embodiment of the present invention.
6 is a detailed configuration diagram of an operation unit of the high-frequency heating device of FIG.
FIG. 7 is a flowchart showing a heating control example of the high-frequency heating device of the present invention.
8 is a heating distribution characteristic diagram of a pseudo load when the high-frequency heating device of FIG. 1 is used.
[Fig. 9] (a) State diagram when curry is applied to rice as a test sample.
  (B) Heating distribution characteristic diagram in actual cooking of sample when using high-frequency heating device of the present invention (c) Heating distribution characteristic diagram in actual cooking of sample when using conventional high-frequency heating device
FIG. 10 is a configuration diagram of a high-frequency heating device showing Embodiment 2 of the present invention.
11 is a cross-sectional configuration diagram of the high-frequency heating device of FIG. 10;
12 is a heating distribution characteristic diagram of a pseudo load when the high-frequency heating device of FIG. 10 is used.
13 is a heating characteristic diagram in actual cooking when using the high-frequency heating device of FIG.
[Explanation of symbols]
  10, 47 Microwave space
  20 Opening part
  21 Impedance variable means
  23 Groove
  24 Dielectric plate
  26, 49 Heating area selection input section
  27, 50 Display means
  29 Control unit
  30 Microwave sensor (support angle detection means)
  36 Stepping motor (dielectric plate rotation drive means)
  43 Placement dish
  44 Loading tray driving means

Claims (10)

A microwave space for containing the object to be heated and substantially confining the supplied microwave ; an opening provided to divide a flow of a high-frequency current generated in a metal wall surface forming the microwave space; Impedance variable means for changing the impedance of the opening, a heating area selection input section for selecting and specifying the heating area of the object to be heated, and the impedance variable means for driving the impedance variable means based on an input signal of the heating area selection input section A control unit that controls the impedance of the opening, and the impedance variable means includes a groove connected to the opening and closed at the end, and a low dielectric loss material rotatably supported in the groove. A dielectric plate and a dielectric plate rotation driving means for rotating the dielectric plate, and the control unit corresponds to a signal of the heating region selection input unit. It said dielectric plate defining a predetermined angle, and continuously variable control high-frequency heating apparatus. 2. The high frequency heating apparatus according to claim 1, further comprising display means for displaying a flow of microwaves to the heated object corresponding to the heated area of the heated object based on an input signal of the heating area selection input unit. The high-frequency heating device according to claim 1 or 2, further comprising: a mounting tray on which an object to be heated is mounted; and a mounting tray rotation driving unit that rotationally drives the mounting tray . The heating area selection input unit is a central heating mode for heating at least the center of the object to be heated stored in the central part of the microwave space as an input key for selecting and specifying the heating area of the object to be heated, and the periphery of the object to be heated high-frequency heating apparatus according to claim 1, any one of 3 and a peripheral heating mode for heating the. The heating area selection input unit is a central heating mode for heating at least the center of the object to be heated stored in the central part of the microwave space as an input key for selecting and specifying the heating area of the object to be heated, and the periphery of the object to be heated And a peripheral heating mode for heating the pan, the control unit controls the mounting plate rotation driving means to be in a non-operating state based on an input signal at least when the peripheral heating mode is selected. 3. The high frequency heating apparatus according to 3. The heating area selection input unit has an overall heating mode for selecting the entire object to be heated as the heating area as an input key for selecting and specifying the heating area of the object to be heated, and the control unit is configured to select the entire heating mode when the entire heating mode is selected. based on the input signals, according to claim 1 Symbol placement of the high-frequency heating apparatus characterized by continuously variably controlling the impedance of the opening portion. The heating area selection input unit has an overall heating mode for selecting the entire object to be heated as the heating area as an input key for selecting and specifying the heating area of the object to be heated, and the control unit is configured to select the entire heating mode when the entire heating mode is selected. Based on the input signal, the impedance of the opening portion is continuously variably controlled, or the impedance of the opening portion is continuously variably controlled and the placing plate rotation driving means is controlled to be in an operating state. The high-frequency heating device according to claim 3, wherein Based on the input signal of the heating region selection input unit, the control unit drives the impedance variable means to control the impedance of the aperture to a specified value and drives the impedance variable means within the heating time of the object to be heated to specify the specified value. high-frequency heating apparatus according to claim 1, wherein the varying the impedance value vertically around the the impedance value. The support angle of the dielectric plate has a detection function of determining, high-frequency heating apparatus according to claim 1, wherein the rotation control of the dielectric plate at a predetermined angle. Supporting lifting angle is high-frequency heating apparatus according to claim 9, wherein the determining based on the microwave signal in the groove.

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