JP2017182885A - High-frequency heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-frequency heating device capable of suppressing leakage electric field while suppressing upsizing.SOLUTION: A high-frequency heating device 100 comprises an upper electrode 1, a lower electrode 2 arranged below the upper electrode 1, and a voltage application unit 10 which applies high-frequency voltage between the upper electrode 1 and the lower electrode 2. An auxiliary electrode 11 is provided around the upper electrode 1. The voltage application unit 10 applies the voltage different from the high-frequency voltage applied between the upper electrode 1 and the lower electrode 2 between the lower electrode 1 and the auxiliary electrode 11. The upper electrode 1 may include four rectangular first electrode plates 1a, 1c, 1b, and 1d. The lower electrode 2 may include four rectangular second electrode plates 2A, 2B, 2C, and 2D.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a high-frequency heating apparatus that applies a high-frequency electric field to food or the like to perform heat treatment, thawing treatment, and the like.

  In the high-frequency heating device, a high-frequency high voltage is applied between two electrodes, and dielectric heating is performed with an object to be thawed interposed therebetween. FIG. 31 shows a thawing device that performs thawing processing by dielectric heating using high frequency. The thawing apparatus 1000 includes a metal heating chamber 1008. In the heating chamber 1008, an upper electrode 1001, a lower electrode 1002, a bottom plate 1007, and the like are provided. The upper electrode 1001 and the lower electrode 1002 are each formed of a single metal plate and are arranged in parallel to each other. The bottom plate 1007 is disposed on the lower electrode 1002. An object to be thawed 1003 is placed on the bottom plate 1007.

  A high frequency oscillator 1005, a matching circuit 1006, and the like are provided outside the heating chamber 1008. The high-frequency oscillator 1005 and the matching circuit 1006 are connected to the upper electrode 1001 and the lower electrode 1002 by wiring. A high frequency high voltage is supplied from the high frequency oscillator 1005 to the upper electrode 1001 and the lower electrode 1002. As a result, a high-frequency electric field is generated between the upper electrode 1001 and the lower electrode 1002, the object 1003 to be thawed is dielectrically heated, and the object 1003 is thawed.

  If an air gap exists between the upper electrode 1001 and the material 1003 to be thawed, the heating efficiency is lowered. Therefore, the thawing apparatus 1000 is provided with an elevating mechanism 1004 for moving the upper electrode 1001 in the vertical direction. The elevating mechanism 1004 moves the upper electrode 1001 in the vertical direction according to the thickness of the object 1003 to be thawed.

  Recently, it has been studied to provide a more practical thawing apparatus by improving the basic configuration of the high-frequency heating apparatus as described above. For example, Patent Document 1 discloses a dielectric heating device in which a third electrode plate is disposed and the same potential as that of a fixed electrode is provided for the purpose of simplifying load matching or reducing energy loss.

Japanese Patent No. 3640621

  As described above, the high-frequency heating device performs a thawing process on the object to be thawed by applying a high-frequency electric field to the object to be thawed in the heating chamber. Therefore, a leakage electric field is generated outside the heating chamber. The leakage electric field value from the high-frequency heating device is limited by a regulation value determined by the Radio Law or a guideline value. Therefore, measures to suppress the leakage electric field are required.

  As a countermeasure against a general leakage electric field, grounding of a metal housing is known. However, in the heating chamber, there is a possibility that a gap between the joining parts of the parts constituting the metal casing or an opening generated for structural reasons may be formed. In such a case, it becomes difficult to satisfy the above regulation value. Further, if it is attempted to suppress the leakage electric field only by the structure of the metal casing, it is necessary to take measures such as providing multiple shields with metal, which causes a problem of increasing the size of the apparatus. For this reason, countermeasures against leakage electric fields using a technique different from such a technique are desired.

  Therefore, an object of the present invention is to provide a high-frequency heating device capable of suppressing a leakage electric field while suppressing an increase in size of the device.

  The high-frequency heating device according to the first aspect of the present invention includes an upper electrode, a lower electrode disposed below the upper electrode, and a voltage application unit that applies a high-frequency voltage between the upper electrode and the lower electrode. Is a high-frequency heating device. In this high frequency heating apparatus, an auxiliary electrode is provided around the upper electrode. The voltage application unit applies a voltage different from the high-frequency voltage applied between the upper electrode and the lower electrode between the lower electrode and the auxiliary electrode.

  The high-frequency heating device may further include a heating chamber that houses the upper electrode and the lower electrode, and the auxiliary electrode may be connected to the same potential as the heating chamber.

  In the high-frequency heating device, the voltage applied between the lower electrode and the auxiliary electrode may be the same frequency as that of the high-frequency voltage applied between the upper electrode and the lower electrode, and in reverse phase. Good.

  In the high-frequency heating device, the upper electrode has a plurality of rectangular first electrode plates, and the lower electrode has a plurality of rectangular second electrode plates, and the first electrode plate And the second electrode plate has a long side and a short side, respectively, and the long side of the first electrode plate and the long side of the second electrode plate cross each other. One electrode plate and a second electrode plate may be disposed. The long side of the first electrode plate and the long side of the second electrode plate are preferably substantially orthogonal to each other. The plurality of rectangular first electrode plates or the plurality of rectangular second electrode plates may be connected to the matching circuit, respectively.

  The high-frequency heating device may further include a second auxiliary electrode between the upper electrode and the lower electrode. The second auxiliary electrode has an opening in the central portion, and is disposed at substantially the same position as the position of the upper surface of the object to be heated. Between the lower electrode and the second auxiliary electrode, A voltage different from the high-frequency voltage applied between the upper electrode and the lower electrode may be applied.

  The high-frequency heating device further includes a door for opening and closing a heating chamber that accommodates the upper electrode and the lower electrode, and an elevating mechanism that moves the upper electrode in the vertical direction. The upper electrode may be raised in conjunction with the opening operation.

  The high-frequency heating device further includes a heating chamber door, the opening operation of the heating chamber door and the raising operation of the upper electrode are interlocked, and the closing operation of the heating chamber door and the lowering operation of the upper electrode are May be linked.

  The high-frequency heating device may further include a heating chamber door, and the opening operation of the heating chamber door and the lowering operation of the lower electrode may be interlocked.

  The high-frequency heating device further includes a heating chamber door, the opening operation of the heating chamber door and the lowering operation of the lower electrode are interlocked, and the closing operation of the heating chamber door and the raising operation of the lower electrode are May be linked.

  As described above, the high-frequency heating device of the present invention includes a voltage application unit that applies a voltage different from the high-frequency voltage applied between the upper electrode and the lower electrode between the lower electrode and the auxiliary electrode. ing. Therefore, the leakage electric field from the high frequency heating device can be suppressed without changing the structure of the metal casing constituting the heating chamber of the high frequency heating device.

It is a schematic diagram which shows the internal structure of the high frequency heating apparatus concerning the 1st Embodiment of this invention. It is a schematic diagram which shows the structure in the heating chamber of the high frequency heating apparatus concerning the 1st Embodiment of this invention. It is a circuit diagram which shows the internal structure of the matching circuit in the high frequency heating apparatus shown in FIG. It is a figure which shows the equivalent circuit structure between each electrode and matching circuit in the high frequency heating apparatus shown in FIG. It is a figure which shows the circuit structure between each electrode and matching circuit in the high frequency heating apparatus shown in FIG. It is a schematic diagram which shows the measurement position of a leakage electric field in a high frequency heating apparatus. (A) is a graph which shows the result of having calculated the electric field value in the high frequency heating apparatus which has an auxiliary electrode. (B) is a graph which shows the result of having calculated the electric field value in the high frequency heating apparatus which does not have an auxiliary electrode. (C) is a schematic diagram which shows the position of the high frequency heating apparatus corresponding to the horizontal axis of the graph shown to (a) and (b). (A) And (b) is a figure which shows typically the relationship between the opening / closing operation | movement of the door of a high frequency heating apparatus, and the raising / lowering operation | movement of an upper electrode. It is a side view which shows the raising / lowering mechanism of the upper electrode with which the high frequency heating apparatus concerning the 1st Embodiment of this invention was equipped. It is a top view which shows the raising / lowering mechanism of the upper electrode with which the high frequency heating apparatus concerning the 1st Embodiment of this invention was equipped. It is a front view which shows the raising / lowering mechanism of the upper electrode with which the high frequency heating apparatus concerning the 1st Embodiment of this invention was equipped. It is a schematic diagram which shows the internal structure of the high frequency heating apparatus concerning the 2nd Embodiment of this invention. It is a figure which shows the equivalent circuit structure between each electrode and matching circuit in the high frequency heating apparatus shown in FIG. It is a figure which shows the waveform (phase) of the voltage applied to the upper electrode and auxiliary electrode of the high frequency heating apparatus shown in FIG. (A) is a graph which shows the result of having calculated the electric field value in the high frequency heating apparatus which applied the reverse phase voltage to the auxiliary electrode. (B) is a graph which shows the result of having calculated the electric field value in the high frequency heating apparatus at the time of making an auxiliary electrode into a grounding potential. (C) is a schematic diagram which shows the position of the high frequency heating apparatus corresponding to the horizontal axis of the graph shown to (a) and (b). It is a graph which shows the relationship between the voltage applied to an auxiliary electrode, and the peak value of a leakage electric field. It is a schematic diagram which shows the internal structure of the high frequency heating apparatus concerning the 3rd Embodiment of this invention. It is a schematic diagram which shows the structure in the heating chamber of the high frequency heating apparatus concerning the 3rd Embodiment of this invention. It is a figure which shows the equivalent circuit structure between the electrode and matching circuit in the high frequency heating apparatus shown in FIG. It is a schematic diagram which shows an example of a structure of the electrode in the high frequency heating apparatus shown in FIG. It is a schematic diagram which shows the other example of a structure of the electrode in the high frequency heating apparatus shown in FIG. It is a schematic diagram which shows the internal structure of the high frequency heating apparatus concerning the 4th Embodiment of this invention. It is a figure which shows the equivalent circuit structure between the electrode and matching circuit in the high frequency heating apparatus shown in FIG. It is a schematic diagram which shows an example of a structure of the electrode in the high frequency heating apparatus shown in FIG. (A) is a schematic diagram which shows the internal structure of the high frequency heating apparatus concerning the 5th Embodiment of this invention. (B) is a figure which shows the equivalent circuit structure between the electrode and matching circuit in the high frequency heating apparatus shown to (a). It is a side view which shows the raising / lowering mechanism of the upper electrode with which the high frequency heating apparatus concerning the 6th Embodiment of this invention was equipped. It is a top view which shows the raising / lowering mechanism of the upper electrode with which the high frequency heating apparatus concerning the 6th Embodiment of this invention was equipped. It is a front view which shows the raising / lowering mechanism of the upper electrode with which the high frequency heating apparatus concerning the 6th Embodiment of this invention was equipped. It is a schematic diagram which shows the internal structure of the high frequency heating apparatus concerning reference embodiment of this invention. It is a schematic diagram which shows the internal structure of the high frequency heating apparatus concerning another reference form. It is a schematic diagram which shows the structure of the conventional thawing | decompression apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
(Schematic configuration of the high-frequency heating device)
First, a schematic configuration of the high-frequency heating device 100 according to the present embodiment will be described with reference to FIGS. 1 and 2. The high-frequency heating apparatus 100 according to the present embodiment applies a high-frequency electric field to the object to be heated 3 such as food to perform heat treatment, thawing process, and the like on the object to be heated. The high-frequency heating device 100 includes a heating chamber 8. The heating chamber 8 is formed of a metal casing.

  As shown in FIG. 2, the heating chamber 8 includes an upper electrode 1, a lower electrode 2, an elevating mechanism 4, a bottom plate 7, an auxiliary electrode 11, a top plate 12, and the like. The upper electrode 1 and the lower electrode 2 are each composed of a plurality of metal plates, as will be described later. The upper electrode 1 and the lower electrode 2 are arranged in parallel to each other. The bottom plate 7 is disposed on the lower electrode 2 and is in close contact with the lower electrode 2. The top plate 12 is disposed below the upper electrode 1 and is in close contact with the upper electrode 1. The auxiliary electrode 11 is disposed on the same plane as the upper electrode 1 and is disposed around the upper electrode 1. The upper electrode 1 and the auxiliary electrode 11 are insulated.

  The upper electrode 1 and the top plate 12 are connected to the lifting mechanism 4. The elevating mechanism 4 is provided with a gear, a motor, and the like. Thereby, the raising / lowering mechanism 4 moves to an up-down direction. As the elevating mechanism 4 moves, the position of the upper electrode 1, the auxiliary electrode 11, and the top plate 12 connected to the elevating mechanism 4 can also be changed in the vertical direction. Thereby, the position of the upper electrode 1 can be changed according to the magnitude | size of the to-be-heated material 3 at the time of heat processing.

  When heating or thawing the object to be heated 3 using the high-frequency heating device 100, the object to be heated 3 is placed on the bottom plate 7. Then, a high frequency electric field is applied between the upper electrode 1 and the lower electrode 2 by a method to be described later, and dielectric heating thawing due to dielectric loss of the article 3 to be heated is performed.

(Configuration of each electrode)
Next, a specific configuration of each electrode in the heating chamber 8 and a configuration of a voltage application unit that applies a voltage to each electrode will be described with reference to FIG.

  As shown in FIG. 1, the upper electrode 1 includes four rectangular (rectangular) first electrode plates 1a, 1c, 1b, and 1d. The lower electrode 2 includes four rectangular (rectangular) second electrode plates 2A, 2B, 2C, and 2D. When viewed from above, the long sides of the first electrode plates 1a, 1c, 1b, and 1d and the long sides of the second electrode plates 2A, 2B, 2C, and 2D are substantially orthogonal to each other. Arranged in a relationship. The auxiliary electrode 11 is disposed so as to surround the four first electrode plates 1a, 1c, 1b, and 1d.

  In addition, a voltage application unit 10 for applying a voltage to each electrode is provided outside the heating chamber 8. The voltage application unit 10 mainly includes a matching circuit 5, a high frequency transmitter 13, an amplifier (high frequency amplifier) 14, an upper electrode switching unit 15, and a lower electrode switching unit 16.

  FIG. 3 shows a circuit configuration in the matching circuit 5. As shown in FIG. 3, the matching circuit 5 includes variable capacitors 5a and 5b, a variable coil 5c, and the like. Thereby, the matching circuit 5 cancels the reactance of the capacitor formed by the upper electrode 1 and the lower electrode 2. The matching circuit 5 can match the input impedance to the matching circuit 5 and the output impedance to the amplifier 14 by adjusting the values of the variable capacitors 5a and 5b and the variable coil 5c.

  The high frequency transmitter 13 transmits a voltage signal having a frequency of HF to VHF band and supplies the voltage signal to the amplifier 14. The amplifier 14 amplifies the voltage signal transmitted from the high frequency transmitter 13 to a desired power. The voltage signal amplified by the amplifier 14 is supplied to the capacitor formed by the upper electrode 1 and the lower electrode 2 through the matching circuit 5 and the upper electrode switching unit 15 and the lower electrode switching unit 16. As a result, a high-frequency electric field is generated between the upper electrode 1 and the lower electrode 2. The heated object 3 placed between the upper electrode 1 and the lower electrode 2 is dielectrically heated.

  The upper electrode switching unit 15 includes a switch for supplying a voltage signal supplied to the upper electrode 1 to each of the four first electrode plates 1a, 1c, 1b, and 1d. The lower electrode switching unit 16 includes switches for connecting the wiring on the matching circuit 5 side and the four second electrode plates 2A, 2B, 2C, and 2D.

Further, as shown in FIG. 1, the heating chamber 8, the lower electrode 2, and the auxiliary electrode 11 are grounded. Thereby, the heating chamber 8, the lower electrode 2, and the auxiliary electrode 11 are at the same potential (specifically, a potential of 0V). On the other hand, the upper electrode 1 is applied with a high-frequency voltage so as to have a potential of V ⁺ , for example.

  FIG. 4 shows an equivalent circuit composed of first electrode plates 1 a, 1 c, 1 b, 1 d constituting the upper electrode 1 and second electrode plates 2 A, 2 B, 2 C, 2 D constituting the lower electrode 2. Indicates. FIG. 4 shows a case where the switch for the first electrode plate 1a is in the ON state in the upper electrode switching unit 15 and the switch for the second electrode plate 2A is in the ON state in the lower electrode switching unit 16.

  As shown in FIG. 4, the equivalent circuit includes an equivalent capacitor 18, an equivalent resistor 19, and an equivalent capacitor 20. The equivalent capacitor 18 includes a first electrode plate 1a on the upper electrode 1 side and a second electrode plate 2A on the lower electrode 2 side. The equivalent resistance 19 is composed of the dielectric loss of the object to be heated 3. The equivalent capacitor 20 includes a first electrode plate 1 a on the upper electrode 1 side and an auxiliary electrode 11. The equivalent capacitor 18 and the equivalent resistor 19 are connected in series. Further, the equivalent capacitor 18 and equivalent resistor 19 and the equivalent capacitor 20 are connected in parallel. The second electrode plate 2A on the lower electrode 2 side and the auxiliary electrode 11 are grounded.

  FIG. 5 shows the configuration of the switches in the upper electrode switching unit 15 and the lower electrode switching unit 16. As shown in FIG. 5, the upper electrode switching unit 15 has a switch for supplying a voltage to be supplied to the upper electrode 1 to each of the four first electrode plates 1a, 1c, 1b, and 1d. doing. The lower electrode switching unit 16 includes switches for connecting the wiring on the matching circuit 5 side and the four second electrode plates 2A, 2B, 2C, and 2D.

  A plurality of first electrode plates 1a, 1c, 1b, and 1d and a plurality of second electrode plates 2A are set by turning on the switches provided in the upper electrode switching unit 15 and the lower electrode switching unit 16. An electric field can be formed between 2B, 2C, and 2D. And, in which region between the upper electrode 1 and the lower electrode 2 depending on which of the switches provided in the upper electrode switching unit 15 and the lower electrode switching unit 16 is turned on and which is turned off. It is possible to select whether to form an electric field. In addition, about the structure which divides | segments the upper electrode 1 into several electrode plates and divides the lower electrode 2 into several electrode plates, the structure similar to 6th Embodiment mentioned later is applicable.

(Regarding suppression of leakage electric field)
Subsequently, suppression of the leakage electric field by the auxiliary electrode 11 will be described below with reference to FIGS. 6 and 7. In the conventional high-frequency heating device, the countermeasure against leakage electric field is taken by surrounding the upper electrode and the lower electrode with a heating chamber made of metal without any gap and by grounding the heating chamber. However, the heating chamber may be inevitably provided with openings and gaps for structural reasons. The present embodiment provides a high-frequency heating device that can appropriately suppress the leakage electric field in such a case.

  For example, in the high-frequency heating apparatus 100 of the present embodiment, a case is assumed in which an opening 21 on the slit is provided on the side surface of the heating chamber 8 as shown in FIG. FIG. 7A shows a result of calculating the electric field on the Z-Z ′ axis of the outer surface of the heating chamber 8 by a difference equation on the plane 22 including the position where the opening 21 is formed. FIG. 7B shows the result of calculating the electric field value in a high-frequency heating apparatus that does not have an auxiliary electrode as a comparison target. Moreover, in FIG.7 (c), the position of the high frequency heating apparatus corresponding to the horizontal axis of the graph shown to Fig.7 (a) and FIG.7 (b) is shown. 7A and 7B, the electric field peak value without the auxiliary electrode shown in FIG. 7B is set to 1, and the electric field value at each position is normalized.

  As shown in FIGS. 7A and 7B, at the position where the opening 21 is formed, the auxiliary electrode 11 is different from the value 1 when there is no auxiliary electrode, as in the high-frequency heating device 100 of the present embodiment. When it was provided, it was 0.27. From this result, it was confirmed that the electric field strength was reduced by providing the auxiliary electrode 11. Therefore, the auxiliary electrode 11 is effective for suppressing the leakage electric field.

(Interlocking movement of upper electrode up and down and heating chamber door opening and closing operation)
Next, the opening / closing operation of the door 42 provided in the heating chamber 8 of the high-frequency heating device 100 of this embodiment and the vertical movement of the upper electrode 1 will be described with reference to FIGS. 8 to 11. FIGS. 8A and 8B schematically show the relationship between the door opening / closing operation of the high-frequency heating device and the upper electrode lifting operation. 9 to 11 show the configuration of the lifting mechanism 4 for the upper electrode 1. For convenience of explanation, the surface on which the door 42 is disposed is the front surface of the high-frequency heating device 100. Then, when the high-frequency heating device 100 is placed in use, the surface located on the left side is the left side surface, the surface located on the right side is the right side surface, and the surface located on the rear side is the front surface. The back surface is defined as the upper surface, and the lower surface is defined as the bottom surface.

  Generally, in the high-frequency heating device, if an air gap exists between an electrode and an object to be heated, heating efficiency is reduced. Therefore, some conventional high-frequency heating devices are provided with a mechanism for moving the electrode up and down in accordance with the thickness of the object to be heated. For example, the patent document (Japanese Patent Laid-Open No. 2002-246165) includes an electrode distance varying means 130 driven by a motor, and the interval between the electrode plates 108 and 109 can be changed according to the size of the object to be thawed 121. A high frequency thawing device is disclosed.

  By the way, when thawing frozen food using a high-frequency heating device, in actual use, it is assumed that the state of the food is confirmed by opening the door of the heating chamber during the heat treatment. However, when the electrode approaches the food, the food is hidden by the electrode, and the state of the food cannot be visually confirmed. Therefore, when an operation for opening the heating chamber door is performed, for example, it is desirable to perform a process of raising the upper electrode.

  However, in the case of a configuration in which the upper electrode is raised by a motor, the control unit in the apparatus detects that an operation for opening the heating chamber door has been performed, and then proceeds to the upper electrode raising process. For this reason, there is a problem that it takes time until the food can be visually observed after opening the heating chamber door, and the operability is poor.

  Therefore, in the high-frequency heating device 100 according to the present embodiment, the elevating mechanism 4 that moves the upper electrode 1 in the vertical direction can raise the upper electrode 1 in conjunction with the opening operation of the door 42. According to this configuration, the upper electrode 1 rises mechanically in conjunction with the opening operation (opening operation) of the heating chamber door 42 (see FIG. 8B). For this reason, it is possible to quickly confirm the state of the food during heating and to take out the food, and the operability of the high-frequency heating device can be improved.

  Moreover, in the high frequency heating apparatus 100 of this embodiment, as shown in FIG. 8A, the upper electrode 1 may be lowered mechanically in conjunction with the closing operation (closing operation) of the heating chamber door 42. Thereby, it can transfer to heat processing immediately after closing the door 42.

  Subsequently, specific configurations of the elevating mechanism 4 and the door 42 will be described. The high-frequency heating device 100 has a heating chamber 8 inside. A heating chamber door 42 that opens and closes the room is attached to the heating chamber 8 (see FIG. 9). As described above, the heating chamber 8 includes the upper electrode 1, the lower electrode 2, the bottom plate 7, the auxiliary electrode 11, the top plate 12, and the like. The upper electrode 1 can be moved up and down by a lifting mechanism 4 in order to improve heating efficiency.

  For example, in this embodiment, the dimension (width × depth × height) of the heating chamber 8 can be set to 200 × 150 × 100 (mm), and the elevation height of the upper electrode 1 can be set to 55 (mm). 9 to 11, the high-frequency power supply (voltage application unit 10) is not shown.

  9 to 11 show a state where the door 42 is closed. Here, the operation of each member when the door 42 is opened from the closed state to the open state of 90 degrees will be described. The lifting mechanism 4 includes an upper electrode column 41, a spur gear 43, a spur gear 44, a bevel gear 45, a bevel gear 46, a bevel gear 47, a bevel gear 48, a pinion gear 49, a rack 51, a heating chamber door column 52, a shaft 53, and a shaft. 54, a shaft 55, a fixing bracket 56, and the like.

  The door 42 and the spur gear 43 are fixed by a fixing bracket 56. When the door 42 is opened from the closed state to the open state of 90 degrees, the spur gear 43 is rotated 90 degrees clockwise as viewed from above. The spur gear 44 meshed with the spur gear 43 has the same number of teeth as the spur gear 43. Therefore, as the spur gear 43 rotates 90 degrees clockwise, the spur gear 44 rotates 90 degrees counterclockwise when viewed from above.

  The spur gear 44 and the bevel gear 45 are attached to the same shaft 53. Thereby, as the spur gear 44 rotates, the bevel gear 45 rotates 90 degrees counterclockwise when viewed from above. The bevel gear 46 is meshed with the bevel gear 45. Further, the bevel gear 46 has 1/3 the number of teeth of the bevel gear 45. As a result, the bevel gear 46 rotates 270 degrees clockwise as viewed from the front (the front of the apparatus 100) as the bevel gear 45 rotates 90 degrees.

  The bevel gear 47 is attached to the same shaft 54 as the bevel gear 46. Therefore, as the bevel gear 46 rotates, the bevel gear 47 rotates 270 degrees clockwise as viewed from the front. The bevel gear 48 has the same number of teeth as the bevel gear 47. Therefore, as the bevel gear 47 rotates 270 degrees, it rotates 270 degrees clockwise as viewed from the left side surface of the apparatus 100.

  The pinion gear 49 is attached to the same shaft 55 as the bevel gear 48. Therefore, as the bevel gear 48 rotates, the pinion gear 49 rotates 270 degrees clockwise as viewed from the left side. The rack 51 is attached to the upper electrode column 41. Therefore, the rack 51 rises together with the upper electrode column 41 and the upper electrode 1 as the pinion gear 49 rotates. For example, the module and the number of teeth of the pinion gear 49 can be set so that the rack 51 satisfies the elevation height 55 (mm) by the rotation of the pinion gear 49 by 270 degrees. Here, the module is 1 and the number of teeth is 24. However, the present invention is not limited to this.

  When the heating chamber door 42 is closed from the 90-degree open state to the closed state, the upper electrode 1 performs an operation opposite to the above-described movement and descends 55 (mm).

  As described above, in the high-frequency heating device 100 of the present embodiment, the opening / closing operation of the heating chamber door 42 and the raising / lowering operation of the upper electrode 1 are interlocked. Thereby, the upper electrode 1 rises simultaneously with opening the heating chamber door 42. Therefore, as compared with the configuration in which the electrodes are moved up and down by the motor, it is possible to more easily check the state of the object to be heated during the heating chamber treatment. Moreover, according to this structure, the speed of the taking in / out operation of the to-be-heated material in the store | warehouse | chamber can be improved.

  Further, when the shape of the object to be heated is constant, the actuator for raising and lowering the electrode can be omitted if the elevation height of the upper electrode 1 is designed according to the thickness of the object to be heated. Thereby, a structure can be made simpler and a low-cost high frequency heating apparatus can be provided.

  In the present embodiment, the configuration in which the distance between the upper electrode 1 and the lower electrode 2 can be changed by moving the upper electrode 1 in the vertical direction has been described. However, in the present invention, the lower electrode 2 is moved in the vertical direction. By moving, the distance between the upper electrode 1 and the lower electrode 2 can be adjusted.

<Second Embodiment>
Subsequently, a second embodiment of the present invention will be described. In the first embodiment described above, the potential of the auxiliary electrode 11 is the same as that of the heating chamber 8 (specifically, the ground potential G). However, the present invention is not limited to such a configuration, and the auxiliary electrode may have a different potential. In the second embodiment, a configuration in which a voltage having an opposite phase to the voltage applied to the upper electrode is applied to the auxiliary electrode for suppressing the leakage electric field will be described.

  In FIG. 12, the high frequency heating apparatus 200 concerning the 2nd Embodiment of this invention is shown. The basic configuration of the high-frequency heating device 200 is the same as that of the high-frequency heating device 100 (see FIG. 1). Therefore, in the high-frequency heating device 200, members having the same structure and function as those of the high-frequency heating device 100 are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 12, the high-frequency heating device 200 includes an auxiliary electrode 211. In the first embodiment, the auxiliary electrode 11 is grounded. On the other hand, in the second embodiment, the auxiliary electrode 211 is not grounded. The auxiliary electrode 211 is connected to the electrode on one side of the variable capacitor 233. The other electrode of the variable capacitor 233 is grounded and connected to the lower electrode 2 (that is, the second electrode plates 2A, 2B, 2C, and 2D) via the lower electrode switching unit 16.

  In FIG. 13, in the high frequency heating apparatus 200, the first electrode plates 1a, 1c, 1b, and 1d that constitute the upper electrode 1, and the second electrode plates 2A, 2B, 2C, and 2D that constitute the lower electrode 2 are shown. The equivalent circuit comprised by is shown. FIG. 13 shows a case where the switch for the first electrode plate 1a is in the ON state in the upper electrode switching unit 15, and the switch for the second electrode plate 2A is in the ON state in the lower electrode switching unit 16.

  As shown in FIG. 13, the equivalent circuit includes an equivalent capacitor 218, an equivalent resistor 219, a variable capacitor 233, and an equivalent capacitor 234. The equivalent capacitor 218 includes a first electrode plate 1a on the upper electrode 1 side and a second electrode plate 2A on the lower electrode 2 side. The equivalent resistance 219 is composed of the dielectric loss of the object to be heated 3. The equivalent capacitor 234 includes a second electrode plate 2 </ b> A on the lower electrode 2 side and an auxiliary electrode 211.

  The equivalent capacitor 218 and the equivalent resistor 219 are connected in series. Further, the equivalent capacitor 218 and equivalent resistor 219 and the equivalent capacitor 234 are connected in series and connected to the output of the matching circuit 5. Further, in order to adjust the voltage ratio of the auxiliary electrode 11 to the upper electrode 1 (for example, the first electrode plate 1a), the variable capacitor 233 is connected in parallel with the equivalent capacitor 234, and the lower electrode 2 (for example, the second electrode 2) The electrode plate 2A) is grounded.

A voltage V ⁻ different from the voltage V ⁺ applied to the upper electrode 1 with respect to the lower electrode 2 (that is, the ground potential G) is applied to the auxiliary electrode 11. 14, the voltage V applied between the voltage V ⁺ of the phase V1 applied, and an auxiliary electrode 11 and the lower electrode 2 between the upper electrode 1 and the lower electrode 2 ^- an example of the phase V2 Indicates. As shown in this figure, the voltage V applied between the auxiliary electrode 11 and the lower electrode 2 ^- phase V2, the voltage V ⁺ of the phase V1 applied between the upper electrode 1 and the lower electrode 2 The phase is opposite at the same frequency. The voltage V ^- absolute value is smaller than the absolute value of the voltage V ^+.

  Next, suppression of the leakage electric field by the auxiliary electrode 211 will be described with reference to FIG. Here, the case where the opening part 21 on a slit is provided in the side surface of the heating chamber 8 of the high frequency heating apparatus 200 similarly to 1st Embodiment is assumed (refer FIG. 6).

  FIG. 15A shows a result of calculating the electric field on the Z-Z ′ axis of the outer surface of the heating chamber 8 by a difference equation on the plane 22 including the position where the opening 21 is formed. In addition, in FIG.15 (b), the result of having calculated the electric field value in the high frequency heating apparatus 100 of 1st Embodiment is shown as a comparison object. FIG. 15C shows the position of the high-frequency heating device corresponding to the horizontal axis of the graphs shown in FIGS. 15A and 15B. In FIG. 15A and FIG. 15B, the electric field peak value without the auxiliary electrode shown in FIG. 7B is set to 1, and the electric field value at each position is normalized.

  FIG. 16 shows the results of evaluation using the voltage ratio of the upper electrode 1 and the auxiliary electrode 211 with respect to the lower electrode 2 as a parameter. The horizontal axis shows the ratio of the voltage applied to the auxiliary electrode 211 to the voltage applied to the upper electrode 1. As shown in FIG. 16, when a voltage is applied such that the voltage ratio of the auxiliary electrode 211 to the upper electrode 1 is 0.1, the electric field value is the lowest. Therefore, in the analysis shown in FIG. 15, a reverse phase voltage having a voltage ratio of 0.1 with respect to the upper electrode 1 is applied to the auxiliary electrode 211.

  As shown in FIG. 15 (a), at the position where the opening 21 is formed in the high-frequency heating device 200 of the present embodiment, the value 0.07 is compared to the value 1 when there is no auxiliary electrode (see FIG. 7 (b)). It became. As shown in FIG. 15B, the measurement result of the high-frequency heating device 100 to be compared was 0.27 with respect to the value 1 in the case of no auxiliary electrode (see FIG. 7B). From this result, it was confirmed that the electric field strength was further reduced by providing the auxiliary electrode 211 as compared with the case of the first embodiment. Therefore, the auxiliary electrode 211 is effective by suppressing the leakage electric field.

  In the high-frequency heating device 200 of the present embodiment, the voltage ratio of the upper electrode 1 and the auxiliary electrode 11 with respect to the lower electrode 2 can be controlled by adjusting the capacity of the variable capacitor 233. Therefore, the voltage ratio of the upper electrode 1 and the auxiliary electrode 11 to the lower electrode 2 is controlled according to the vertical position of the top plate 12 (that is, the relative position of the upper electrode 1 and the auxiliary electrode 11 and the opening 21). Thereby, the leakage electric field suppression according to use conditions can be performed.

<Third Embodiment>
Subsequently, a third embodiment of the present invention will be described. In the first and second embodiments described above, the configuration in which the upper electrode 1 and the lower electrode 2 are each divided into a plurality of rectangular electrodes has been described. However, the present invention is not limited to such a configuration. Therefore, in the third embodiment, a configuration in which the upper electrode 1 and the lower electrode 2 are each formed of a single rectangular metal plate will be described.

  Furthermore, in the third embodiment, a configuration example further including a second auxiliary electrode different from the auxiliary electrode 11 for suppressing the leakage electric field will be described. The second auxiliary electrode is provided for the purpose of heating the object to be heated more uniformly.

  When a frozen food or the like is thawed using a high-frequency heating device, the outer periphery of the food is overheated due to the concentration of high-frequency energy at the edge of the food. In order to solve this problem, for example, during the thawing process, it has been studied to sequentially use a plurality of counter electrodes having different dimensions to suppress degradation of the quality of the heated object during the thawing process.

  However, the technique of properly using electrodes with different dimensions complicates the electrode lifting mechanism. Also. In the above measures, there is a certain limit to the size of the object to be heated.

  Therefore, in the third embodiment, a high-frequency heating apparatus capable of heating an object to be heated more uniformly while suppressing the complexity of the lifting function is provided. 17 and 18 show a high-frequency heating device 300 according to the third embodiment. The basic configuration of the high-frequency heating device 300 is the same as that of the high-frequency heating device 100 (see FIG. 1). Therefore, in the high-frequency heating device 300, members having the same structure and function as those of the high-frequency heating device 100 are denoted by the same reference numerals and description thereof is omitted.

  The high frequency heating device 300 includes a heating chamber 8. As shown in FIG. 18, the heating chamber 8 includes an upper electrode 1, a lower electrode 2, a lifting mechanism 4, a bottom plate 7, an auxiliary electrode 11, a top plate 12, a second auxiliary electrode 301, and the like. ing. The upper electrode 1 and the lower electrode 2 are each composed of a single metal plate. The upper electrode 1 and the lower electrode 2 are arranged in parallel to each other. The auxiliary electrode 11 is disposed on the same plane as the upper electrode 1 and is disposed around the upper electrode 1. The upper electrode 1 and the auxiliary electrode 11 are insulated.

  The second auxiliary electrode 301 is disposed between the upper electrode 1 and the lower electrode 2. The second auxiliary electrode 301 is formed of a single rectangular metal plate. The second auxiliary electrode 301 has a rectangular opening 301a at the center. As shown in FIG. 18, when the object to be heated 3 is disposed between the upper electrode 1 and the lower electrode 2, the second auxiliary electrode 301 is substantially at the same position as the position of the upper surface of the object to be heated 3. As described above, the position in the vertical direction is set. Such position adjustment of the second auxiliary electrode 301 can be performed by a position adjusting mechanism (not shown).

  In addition, a voltage application unit 310 for applying a voltage to each electrode is provided outside the heating chamber 8. The voltage application unit 310 mainly includes a matching circuit 5, a high frequency oscillator 13, an amplifier (high frequency amplifier) 14, a second matching circuit 302, an amplifier (high frequency amplifier) 303, and a phase shifter 304. As shown in FIG. 17, in the voltage application unit 310 of the present embodiment, the high-frequency voltage signal from the high-frequency transmitter 13 is transmitted mainly to the upper electrode 1 side and mainly to the second auxiliary electrode 301 side. .

In the voltage application unit 310, the signal transmission circuit to the upper electrode 1 side includes a matching circuit 5 and an amplifier (high frequency amplifier) 14. The same configuration as that of the first embodiment can be applied to these. As shown in FIG. 17, the heating chamber 8, the lower electrode 2, and the auxiliary electrode 11 are grounded. Thereby, the heating chamber 8, the lower electrode 2, and the auxiliary electrode 11 are at the same potential (specifically, a potential of 0V). On the other hand, the upper electrode 1 is applied with a high-frequency voltage so as to have a potential of V ⁺ , for example. Thereby, the potential difference between the upper electrode 1 and the lower electrode 2 becomes V ⁺ .

  In the voltage application unit 310, the signal transmission circuit to the second auxiliary electrode 301 side includes a second matching circuit 302, an amplifier 303, and a phase shifter 304. The second matching circuit 302 can match the input impedance to the second matching circuit 302 with the output impedance to the amplifier 14. The amplifier 303 amplifies the voltage signal transmitted from the high frequency transmitter 13 to a desired power. The voltage signal amplified by the amplifier 303 is supplied to the equivalent capacitor 322 formed by the second auxiliary electrode 301 and the lower electrode 2 through the second matching circuit 302 (see FIG. 19). Thereby, for example, the voltage V ″ is applied between the second auxiliary electrode 301 and the lower electrode 2. The phase shifter 304 changes the phase of the voltage signal transmitted from the high-frequency oscillator 13. .

  FIG. 19 shows an equivalent circuit including the upper electrode 1, the lower electrode 2, the auxiliary electrode 11, and the second auxiliary electrode 301. The equivalent circuit includes an equivalent capacitor 318, an equivalent resistor 319, an equivalent capacitor 320, an equivalent capacitor 321, and an equivalent capacitor 322. The equivalent capacitor 318 includes an upper electrode 1 and a lower electrode 2. The equivalent resistance 319 is composed of the dielectric loss of the object to be heated 3. The equivalent capacitor 320 includes the upper electrode 1 and the auxiliary electrode 11. The equivalent capacitor 321 includes the upper electrode 1 and the second auxiliary electrode 301. The equivalent capacitor 322 includes the lower electrode 2 and the second auxiliary electrode 301.

The equivalent capacitor 318 and the equivalent resistor 319 are connected in series. The equivalent capacitor 321 and the equivalent capacitor 322 are connected in series. Further, the equivalent capacitor 318 and the equivalent resistor 319, the equivalent capacitor 320, the equivalent capacitor 321 and the equivalent capacitor 322 are connected in parallel. The lower electrode 2 and the auxiliary electrode 11 are grounded. Thereby, the lower electrode 2 and the auxiliary electrode 11 are at the same potential (specifically, a potential of 0 V). On the other hand, a high-frequency voltage is applied to the upper electrode 1 so as to have a potential of V ⁺ , for example. In addition, a high frequency voltage is applied to the second auxiliary electrode 301 so as to have a potential of V ″, for example.

  In the high-frequency heating device 300 of this embodiment, the electric field concentration on the outer periphery of the object to be heated 3 is reduced by applying a voltage different from the voltage applied to the upper electrode 1 to the second auxiliary electrode 301. . This point will be described with reference to FIG.

  FIG. 20 shows high frequency voltages applied to the upper electrode 1, the lower electrode 2, and the second auxiliary electrode 301 through the matching circuits 5 and 302. Further, an interval between the upper electrode 1 and the lower electrode 2 is indicated by L, and an interval between the lower electrode 2 and the second auxiliary electrode 301 is indicated by d.

In the case of a high-frequency heating apparatus in which the second auxiliary electrode 301 is not provided, if there is a space between the upper electrode 1 and the upper end of the object to be heated 3, the physical properties of the object to be heated (dielectric constant ε ₀ · ε _r ) And the dielectric constant of the space causes a potential difference in the horizontal direction. For example, when the upper electrode 1, the lower electrode 2, and the object to be heated 3 are arranged at the distances L and d as shown in FIG. 20, the potential V ′ in the space at the position d from the lower electrode 2 is V ′ = V · d / L, while the potential V ″ of the upper surface of the object to be heated 3 is V ″ <V · d / L. That is, the horizontal potential difference is (V′−V ″).

  Due to the potential difference in the horizontal direction, electric field concentration occurs at the peripheral edge of the upper surface of the object to be heated. Thereby, the peripheral part of the upper surface of the to-be-heated material 3 may be heated intensively compared with another part, and a heating nonuniformity may generate | occur | produce.

  On the other hand, in the high-frequency heating device 300 of the present embodiment, as shown in FIG. 20, the second auxiliary is placed at substantially the same position as the upper surface of the object to be heated 3 (that is, at a position d from the lower electrode 2). An electrode 301 is provided. Then, a voltage is applied to the second auxiliary electrode 301 such that the potential difference between the lower electrode 2 and the second auxiliary electrode 301 becomes V ″. Therefore, the unevenness in heating of the article to be heated 3 can be suppressed.

  The value of the voltage applied to the second auxiliary electrode 301 is preferably substantially the same as the potential of the upper surface of the article 3 to be heated. Here, the potential of the upper surface of the object to be heated 3 is the height of the object to be heated 3 (that is, the distance d), the distance between the object to be heated 3 and the upper electrode 1 (that is, Ld), and the object to be heated. 3 changes in physical properties (relative permittivity). Therefore, it is preferable that the potential V ″ applied to the second auxiliary electrode 301 can be changed based on these conditions. In this embodiment, the amplifier (high frequency amplifier) 303 changes the value of the potential V ″. It functions as a voltage adjustment unit.

  Note that the height of the object to be heated 3 also varies depending on the type of the object to be heated 3. Therefore, it is preferable that the distance d of the second auxiliary electrode 301 can be changed by a position adjustment mechanism. Further, the second auxiliary electrode 301 may be moved up and down together with the upper electrode 1. FIG. 21 shows an example of a configuration in which the second auxiliary electrode 301 and the upper electrode 1 move up and down together.

  As shown in FIG. 21, the second auxiliary electrode 301 is connected to the upper electrode 1 by a support 333. The upper electrode 1 can be moved in the vertical direction by the lifting mechanism 4. Since the second auxiliary electrode 301 and the upper electrode 1 are fixed by the same support 333, the second auxiliary electrode 301 and the upper electrode 1 can be moved up and down together. This eliminates the need to provide a position adjustment mechanism dedicated to the second auxiliary electrode 301.

  As described above, according to the high-frequency heating device 300 of the present embodiment, heating unevenness of the article to be heated 3 can be suppressed and higher-quality heat treatment can be performed. Moreover, it can respond to heat treatment and thawing treatment of various foods of different types and sizes, and can provide a general-purpose high-frequency heating device.

  As described above, in the high-frequency heating device of this embodiment, the lower electrode is set to the ground potential, and the second auxiliary electrode is provided between the upper electrode and the lower electrode. The second auxiliary electrode has a shape surrounding the upper surface of the object to be heated. The voltage application unit applies a voltage different from the high-frequency voltage applied between the lower electrode and the upper electrode between the lower electrode and the second auxiliary electrode.

  In the above-described high-frequency heating device, the voltage application unit may include a voltage adjustment unit that adjusts a voltage applied to the second auxiliary electrode in accordance with the physical property or size of the object to be heated. The voltage adjustment unit may be a variable capacitor.

  Further, in the above high-frequency heating device, the upper electrode and the auxiliary electrode may be fixed to the same support. Further, the support may be movable up and down.

<Fourth Embodiment>
In the above-described third embodiment, the amplifier (high-frequency amplifier) 303 connected to the high-frequency power source (high-frequency transmitter 13) is used as a voltage adjustment unit that adjusts the voltage applied to the second auxiliary electrode. However, the present invention is not limited to this configuration. Therefore, in the fourth embodiment, a configuration using a variable capacitor as the voltage adjustment unit will be described as another example of the voltage adjustment unit.

  FIG. 22 shows a high-frequency heating device 400 according to the fourth embodiment. The basic configuration of the high-frequency heating device 400 is the same as that of the high-frequency heating device 300 (see FIG. 17). Therefore, in the high-frequency heating device 400, members having the same structure and function as those of the high-frequency heating device 300 are denoted by the same reference numerals and description thereof is omitted.

  Outside the heating chamber 8, a voltage application unit 10 for applying a voltage to each electrode is provided. The voltage application unit 10 can employ the same configuration as the voltage application unit provided in the high-frequency heating device 100 of the first embodiment. In the high frequency heating device 400, a variable capacitor 402 is provided between the second auxiliary electrode 401 and the lower electrode 2. By adjusting the capacitance of the variable capacitor 402, for example, a voltage V ″ can be applied between the second auxiliary electrode 401 and the lower electrode 2. That is, it is not necessary to connect to the high frequency transmitter 13).

  FIG. 23 shows an equivalent circuit including the upper electrode 1, the lower electrode 2, the auxiliary electrode 11, and the second auxiliary electrode 401. The equivalent circuit includes an equivalent capacitor 418, an equivalent resistor 419, an equivalent capacitor 420, an equivalent capacitor 421, an equivalent capacitor 422, and a variable capacitor 402. For the equivalent capacitor 418, equivalent resistor 419, and equivalent capacitor 420, the same configuration as that of the high-frequency heating device 300 of the third embodiment can be applied.

  The equivalent capacitor 421 includes the upper electrode 1 and the second auxiliary electrode 401. The equivalent capacitor 422 includes the lower electrode 2 and the second auxiliary electrode 401. The equivalent capacitor 421 and the equivalent capacitor 422 are connected in series. The equivalent capacitor 422 and the variable capacitor 402 are connected in parallel. The lower electrode 2 and the auxiliary electrode 11 are grounded.

Thereby, the lower electrode 2 and the auxiliary electrode 11 are at the same potential (specifically, a potential of 0 V). On the other hand, the upper electrode 1 is applied with a high-frequency voltage so as to have a potential of V ⁺ , for example. Further, between the second auxiliary electrode 401 and the lower electrode 2, for example, the potential difference V ″ is adjusted by the variable capacitor 402 (see FIG. 24).

  As described above, in the high-frequency heating device 400 of this embodiment, the potential of the second auxiliary electrode 401 is adjusted using the variable capacitor 402. Thereby, the electric field concentration to the peripheral part of the upper surface of the to-be-heated material 3 can be relieved, without using the power supply for 2nd auxiliary electrodes.

<Fifth Embodiment>
Subsequently, a fifth embodiment of the present invention will be described. In the first and second embodiments described above, the configuration in which the upper electrode 1 and the lower electrode 2 are each divided into a plurality of rectangular electrodes has been described. However, the present invention is not limited to such a configuration. Therefore, in the fifth embodiment, a configuration in which the upper electrode 501 and the lower electrode 502 are each formed of a single rectangular metal plate will be described.

  FIG. 25A shows a high-frequency heating device 500 according to the fifth embodiment. The basic configuration of the high-frequency heating device 500 is the same as that of the high-frequency heating device 100 (see FIG. 1). Therefore, in the high-frequency heating device 500, members having the same structure and function as those of the high-frequency heating device 100 are denoted by the same reference numerals and description thereof is omitted.

  The high-frequency heating device 500 includes a heating chamber 8. As shown in FIG. 25, inside the heating chamber 8, there are mainly an upper electrode 501, a lower electrode 502, a lifting mechanism (not shown), a bottom plate (not shown), an auxiliary electrode 11, and a top plate (see FIG. 25). Not shown). The upper electrode 501 and the lower electrode 502 are each composed of a single metal plate. The upper electrode 501 and the lower electrode 502 are arranged so as to be parallel to each other. The auxiliary electrode 11 is disposed on the same plane as the upper electrode 1 and is disposed around the upper electrode 501. The upper electrode 501 and the auxiliary electrode 11 are insulated from each other.

  In addition, a voltage application unit 10 for applying a voltage to each electrode is provided outside the heating chamber 8. The voltage application unit 10 mainly includes a matching circuit 5, a high frequency transmitter 13, and an amplifier (high frequency amplifier) 14.

  FIG. 25B shows an equivalent circuit including the upper electrode 501, the lower electrode 502, and the auxiliary electrode 11. The equivalent circuit includes an equivalent capacitor 18, an equivalent resistor 19, and an equivalent capacitor 20. The equivalent capacitor 18 includes an upper electrode 501 and a lower electrode 502. The equivalent resistance 19 is composed of the dielectric loss of the object to be heated 3. The equivalent capacitor 20 includes an upper electrode 501 and an auxiliary electrode 11.

  The equivalent capacitor 18 and the equivalent resistor 19 are connected in series. Further, the equivalent capacitor 18 and equivalent resistor 19 and the equivalent capacitor 20 are connected in parallel. Further, the lower electrode 502 and the auxiliary electrode 11 are grounded.

Further, as shown in FIG. 25A, the heating chamber 8 is grounded. Thereby, the heating chamber 8, the lower electrode 502, and the auxiliary electrode 11 are at the same potential (specifically, a potential of 0V). On the other hand, a high frequency voltage is applied to the upper electrode 501 so as to have a potential of V ⁺ , for example.

  As described above, the high-frequency heating device 500 of this embodiment has the auxiliary electrode 11. Thereby, similarly to the high-frequency heating device 100 of the first embodiment, even when a gap such as an opening is formed in the heating chamber 8, the electric field value in the gap can be reduced (see FIG. 7). ). Therefore, the leakage electric field from the high frequency heating device 500 can be suppressed.

<Sixth Embodiment>
Subsequently, a sixth embodiment of the present invention will be described. The high-frequency heating device 600 according to the sixth embodiment is different from the first embodiment in the interlocking mechanism between the vertical movement of the upper electrode and the opening / closing operation of the heating chamber door. About the other structure, the structure similar to 1st Embodiment is applicable. Therefore, in this embodiment, only points different from the first embodiment will be described.

  26 to 28 show a configuration of a high-frequency heating device 600 according to the sixth embodiment. In particular, these drawings show the configuration of the lifting mechanism 604 of the upper electrode 1. For convenience of explanation, the surface on which the door 42 is disposed is the front surface of the high-frequency heating device 600. Then, when the high-frequency heating device 600 is placed in use, the surface located on the left side is the left side surface, the surface located on the right side is the right side surface, and the surface located on the rear side is the front surface. The back surface is defined as the upper surface, and the lower surface is defined as the bottom surface.

  The basic configuration of the lifting mechanism 604 is the same as that of the lifting mechanism 4 of the first embodiment. Therefore, in the raising / lowering mechanism 604, the same code | symbol is attached | subjected about the member corresponding to the lifting mechanism 4, and the description is abbreviate | omitted.

  The lifting mechanism 604 is different from the lifting mechanism 4 in that the one-way clutch 621 and the shaft 622 are connected between the shaft 55 and the pinion gear 49, and the shaft 55 is extended to the right side of the pinion gear 49. The one-way clutch 625, the shaft 623, and the motor 624 are connected (see FIGS. 27 and 28).

  The one-way clutch 621 transmits to the shaft 622 only the rotation direction when the heating chamber door 42 shifts from the closed state to the open state among the rotations of the shaft 55. Thereby, when the heating chamber door 42 shifts from the closed state to the open state, the upper electrode 1 is raised. On the other hand, when the heating chamber door 42 shifts from the open state to the closed state, the upper electrode 1 does not move.

  The one-way clutch 625 transmits the rotation of the shaft 623 to the shaft 622 only when the motor 624 rotates in the direction of lowering the upper electrode 1 among the rotations of the shaft 623. As a result, the upper electrode 1 can be lowered by the motor 624. In addition, the motor 624 does not interfere with the operation of raising the upper electrode 1 by the heating chamber door 42.

  According to the above configuration, the lowering operation of the upper electrode 1 can be performed by the motor 624. Therefore, the stop position when the upper electrode 1 is lowered can be adjusted by the thickness of the article 3 to be heated. Thereby, the heating efficiency of the high-frequency heating device can be further improved.

  In the present embodiment, the configuration in which the distance between the upper electrode 1 and the lower electrode 2 can be changed by moving the upper electrode 1 in the vertical direction has been described. However, in the present invention, the lower electrode 2 is moved in the vertical direction. By moving, the distance between the upper electrode 1 and the lower electrode 2 can be adjusted.

<Reference form>
Then, the form used as the reference of this invention is demonstrated. Generally, in the high-frequency heating device, if an air gap exists between an electrode and an object to be heated, heating efficiency is reduced. Therefore, some conventional high-frequency heating devices are provided with a mechanism for moving the electrode up and down in accordance with the thickness of the object to be heated. For example, the patent document (Japanese Patent Laid-Open No. 2002-246165) includes an electrode distance varying means 130 driven by a motor, and the interval between the electrode plates 108 and 109 can be changed according to the size of the object to be thawed 121. A high frequency thawing device is disclosed.

  By the way, especially the to-be-heated material (thaw material to be thawed), such as frozen food, is not homogeneous in composition, and the thickness depending on the part is not constant. Dielectric losses are different due to different food compositions. Thereby, the magnitude | size of the heat_generation | fever by a high frequency electric field changes for every composition of to-be-heated material, and leads to a heating village (thaw unevenness). In addition, when the size of the air gap differs due to the difference in thickness depending on the part, a phenomenon occurs in which a portion with a large air gap is difficult to be heated and a portion with a small air gap is easily heated. Thereby, the magnitude | size of heat_generation | fever differs in the site | part of a to-be-heated material, and leads to a heating nonuniformity.

  Therefore, in the patent document (Japanese Patent Laid-Open No. 5-41971), a plurality of electrode pairs are installed in the heating chamber, and the heating time is individually set for each electrode pair. Thereby, the heating nonuniformity with respect to the to-be-heated material whose composition and thickness are not uniform is suppressed.

  However, if the number of heating zones is increased in order to heat the part to be heated finely, electrode pairs are required by the number of heating zones. For example, FIG. 30 shows a high-frequency heating apparatus 900 in which an upper electrode 901 and a lower electrode 902 are divided into four parts in the vertical and horizontal directions (X direction and Y direction). The high-frequency heating apparatus 900 includes an upper electrode 901, a lower electrode 902, a voltage application unit 910, an upper electrode switching unit 903, a lower electrode switching unit 909, and the like. The voltage application unit 910 includes a high frequency transmitter 906, an amplifier (high frequency amplifier) 907, and a matching circuit 908.

  The upper electrode 901 is divided into 16 first electrode plates 11U to 44U. The lower electrode 902 is divided into 16 second electrode plates 11L to 44L so as to form a pair with the 16 first electrode plates 11U to 44U. Thus, the high-frequency heating apparatus 900 requires a combination of 16 electrode plates in order to form 16 heating zones.

  Further, in order to supply high frequency power to each electrode, a power line 911 is required for each electrode plate from the upper electrode switching unit 903 and the lower electrode switching unit 909. This complicates the device configuration. In addition, when this configuration is combined with a configuration in which the electrodes are moved up and down as in the patent document (Japanese Patent Application Laid-Open No. 2002-246165), there is a problem that the apparatus is further complicated and enlarged.

  Therefore, in the present embodiment, a high-frequency heating device 700 that can suppress heating unevenness while suppressing complication of the device is provided. In FIG. 29, the structure of the high frequency heating apparatus 700 concerning this reference form is shown.

  The high-frequency heating device 700 includes an upper electrode 701, a lower electrode 702, a voltage application unit 710, an upper electrode switching unit 703, a lower electrode switching unit 709, and the like. The voltage application unit 710 includes a high frequency transmitter 706, an amplifier (high frequency amplifier) 707, and a matching circuit 708.

  In the high-frequency heating device 700, the upper electrode 701 is composed of four rectangular (rectangular) first electrode plates A, B, C, and D. In the high-frequency heating device 700, the lower electrode 702 includes four rectangular (rectangular) second electrode plates E, F, G, and H. The first electrode plates A, B, C, and D are connected to the upper electrode switching unit 703 by power lines 711, respectively. The second electrode plates E, F, G, and H are connected to the lower electrode switching unit 709 by power lines 711, respectively. This is the same as the configuration of the high-frequency heating device 100 according to the first embodiment. However, the auxiliary electrode 11 is not provided in the high-frequency heating device 700.

  When viewed from above the upper electrode 701, the long sides of the first electrode plates A, B, C, and D and the long sides of the second electrode plates E, F, G, and H are substantially orthogonal to each other. It is arranged in such a positional relationship. In this reference embodiment, the upper electrode 701 and the lower electrode 702 both have four electrode divisions. The long side direction of the first electrode plates A, B, C, and D of the upper electrode 701 is defined as the Y axis, and the long side direction of the second electrode plates E, F, G, and H of the lower electrode 702 is defined as the X axis It is said. However, the division number, shape, and arrangement of each electrode plate are not limited to this.

  In the high-frequency heating device 700, the number of heating zones is represented by the product of the number of divisions of the upper electrode 701 and the number of divisions of the lower electrode 702. When heating an arbitrary part of the object to be heated, a high frequency voltage is applied between the first electrode plate and the second electrode plate located above and below the area of the part to be heated. A high frequency electric field is generated in an area where the projected areas of the upper electrode 701 and the lower electrode 702 overlap with respect to the Z-axis direction of the area to be heated. And the to-be-heated material located in the said area is dielectrically heated.

  For example, in FIG. 29, the number of divisions of the upper electrode 701 is 4, the number of divisions of the lower electrode 702 is 4, and the number of heating zones is 16. In order to heat the object to be heated in the X4Y4 area shown in FIG. 29, the upper electrode switching unit 703 connects the first electrode plate D to the voltage application unit 710, and the lower electrode switching unit 709 grounds the lower electrode H. Connect to potential G. As a result, a high-frequency electric field is generated in the area X4Y4 where the projected areas of the upper electrode 701 and the lower electrode 702 overlap with respect to the Z-axis direction of the area to be heated. Thereby, the to-be-heated object located in the area X4Y4 is dielectrically heated.

  According to the above configuration, even if the number of heating zones in the heating chamber increases, the number of electrode pairs can be reduced, and the number of power lines connected to the electrodes can be reduced. Thereby, the complexity and enlargement of the apparatus can be suppressed.

  As another form, a configuration in which the matching circuit 708 is provided between the first electrode plates A, B, C, and D and the upper electrode switching unit 703 is also possible. In this case, a power detection circuit may be disposed between each matching circuit 708 and the upper electrode switching unit 703. By employ | adopting such a structure, when heating several areas simultaneously, a voltage can be adjusted for every area. Thereby, finer heating adjustment can be performed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims. Further, configurations obtained by combining the configurations of the different embodiments described in this specification with each other are also included in the scope of the present invention.

1: Upper electrodes 1a-1d: First electrode plate 2: Lower electrodes 2A-2D: Second electrode plate 4: Lifting mechanism 8: Heating chamber 10: Voltage application unit 11: Auxiliary electrode 42: (of heating chamber) Door 301: second auxiliary electrode

Claims (6)

An upper electrode;
A lower electrode disposed below the upper electrode;
A high-frequency heating apparatus comprising a voltage application unit that applies a high-frequency voltage between the upper electrode and the lower electrode,
An auxiliary electrode is provided around the upper electrode,
The high-frequency heating apparatus, wherein the voltage application unit applies a voltage different from a high-frequency voltage applied between the upper electrode and the lower electrode between the lower electrode and the auxiliary electrode. A heating chamber that houses the upper electrode and the lower electrode;
The high-frequency heating device according to claim 1, wherein the auxiliary electrode is connected to the same potential as the heating chamber.   2. The high frequency according to claim 1, wherein the voltage applied between the lower electrode and the auxiliary electrode is the same frequency as the high frequency voltage applied between the upper electrode and the lower electrode, and has an opposite phase. Heating device. The upper electrode has a plurality of rectangular first electrode plates,
The lower electrode has a plurality of rectangular second electrode plates,
Each of the first electrode plate and the second electrode plate has a long side and a short side,
The first electrode plate and the second electrode plate are disposed so that a long side of the first electrode plate and a long side of the second electrode plate intersect each other. The high-frequency heating device according to any one of 3. A second auxiliary electrode between the upper electrode and the lower electrode;
The second auxiliary electrode has an opening in the central portion and is disposed at a position substantially the same as the position of the upper surface of the object to be heated,
4. The voltage according to claim 1, wherein a voltage different from a high frequency voltage applied between the upper electrode and the lower electrode is applied between the lower electrode and the second auxiliary electrode. The high-frequency heating device according to item. A door for opening and closing a heating chamber that houses the upper electrode and the lower electrode;
An elevating mechanism for moving the upper electrode in the vertical direction;
The high-frequency heating device according to any one of claims 1 to 5, wherein the elevating mechanism raises the upper electrode in conjunction with an opening operation of the door.

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