High-frequency heating equipment

Abstract

The high frequency heating apparatus according to the present disclosure comprises heating chamber, a first electrode, a second electrode, a high frequency power supply, and a control unit. The first electrode is disposed in the heating chamber. The second electrode is disposed in the heating chamber so as to face the first electrode. The high frequency power supply generates high frequency power. The control unit controls the high frequency power supply. The control unit causes the high frequency power supply to apply high frequency power between the first electrode and the second electrode to control heating of an object to be heated placed between the first electrode and the second electrode. The control unit controls the high frequency power supply so as to selectively perform heating in a normal mode wherein the entire object to be heated is heated and a protective mode wherein localized overheating of the object to be heated is suppressed.

Description

[Technical Field]

[0001] The present disclosure relates to a radio frequency heating device. [Background technology]

[0002] BACKGROUND ART Conventionally, there has been known a high-frequency heating device in which an object to be heated is placed between opposing electrodes and high-frequency power is supplied to the electrodes to heat the object (for example, Patent Document 1).

[0003] The high-frequency heating device described in Patent Document 1 supplies high-frequency power to an electrode having a plate surface shape smaller than the object to be heated, and then supplies high-frequency power to an electrode having a plate surface shape larger than the electrode. The above-mentioned conventional high-frequency heating device is intended to prevent high-frequency energy from concentrating on the edges and to heat the object to be heated uniformly. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent No. 4630189 Summary of the Invention

[0005] However, in the conventional high-frequency heating device described above, it is necessary to change the electrode size depending on the size of the object to be heated, and therefore, when multiple types of objects are to be heated sequentially in a short period of time, it is time-consuming to change the electrode.

[0006] An object of the present disclosure is to provide a high-frequency heating device that can heat a plurality of types of objects to be heated that have different sizes with a simpler configuration.

[0007] The high frequency heating device of the present disclosure includes a heating chamber, a first electrode, a second electrode, a high frequency power supply, and a control unit.

[0008] The first electrode is an electrode disposed within the heating chamber. The second electrode is an electrode disposed within the heating chamber and faces the first electrode. The high frequency power source generates high frequency power. The control unit controls the high frequency power source.

[0009] The control unit controls the high-frequency power supply to apply high-frequency power between the first electrode and the second electrode to heat an object placed between the first electrode and the second electrode. The control unit controls the high-frequency power supply to selectively heat the entire object in a normal mode or in a protection mode to prevent local overheating of the object.

[0010] The high-frequency heating device of the present disclosure can heat an object to be heated with a simple configuration. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic configuration diagram of a high-frequency heating device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic plan view of the first electrode according to the first embodiment. [Figure 3] FIG. 3 is a schematic plan view showing the position of the object to be heated on the first electrode according to the first embodiment. [Figure 4] FIG. 4 is a schematic plan view showing the position of the object to be heated on the first electrode according to the first embodiment. [Figure 5] FIG. 5 is a diagram showing selectable heating courses in the first embodiment and the operation of the high-frequency heating device in each heating course. [Figure 6] FIG. 6 is a schematic diagram of the high frequency power supply according to the first embodiment. [Figure 7] FIG. 7 is a schematic configuration diagram of the matching unit according to the first embodiment. [Figure 8] FIG. 8 is a diagram showing the temperature distribution of the object to be heated thawed by heating courses A to D. [Figure 9] FIG. 9 is a schematic configuration diagram of a high-frequency heating device according to the second embodiment of the present disclosure. [Figure 10]FIG. 10 is a schematic plan view of a first electrode according to the second embodiment. [Figure 11] FIG. 11 is a schematic plan view showing the position of the object to be heated on the first electrode according to the second embodiment. [Figure 12] FIG. 12 is a diagram showing selectable heating courses in the second embodiment and the operation of the high-frequency heating device in each heating course. DETAILED DESCRIPTION OF THE INVENTION

[0012] A high-frequency heating device according to a first aspect of the present disclosure includes a heating chamber, a first electrode, a second electrode, a high-frequency power supply, and a control unit.

[0013] The first electrode is an electrode disposed within the heating chamber. The second electrode is an electrode disposed within the heating chamber and faces the first electrode. The high frequency power source generates high frequency power. The control unit controls the high frequency power source.

[0014] The control unit controls the high-frequency power supply to apply high-frequency power between the first electrode and the second electrode to heat an object placed between the first electrode and the second electrode. The control unit controls the high-frequency power supply to selectively heat the entire object in a normal mode or in a protection mode to prevent local overheating of the object.

[0015] According to this aspect, in the protection mode, the object can be heated evenly while preventing overheating of the object, whereas in the normal mode, the entire object can be heated more quickly than in the protection mode.

[0016] The protection mode is effective when the height of the object to be heated is higher than a predetermined value, or when the initial temperature of the object to be heated is lower than a predetermined value, etc. The normal mode is effective when the height of the object to be heated is lower than a predetermined value, etc.

[0017] In a high-frequency heating device according to a second aspect of the present disclosure, in addition to the first aspect, the first electrode includes a plurality of divided electrodes. In the protection mode, the control unit controls the high-frequency power source to supply high-frequency power to a divided electrode of the plurality of divided electrodes that faces a portion of the object to be heated. The control unit controls the high-frequency power source not to supply high-frequency power to a divided electrode of the plurality of divided electrodes that faces another portion of the object to be heated.

[0018] According to this aspect, it is possible to prevent local overheating of the object to be heated, and to heat the object uniformly.

[0019] In a high-frequency heating device according to a third aspect of the present disclosure, in addition to the second aspect, In the protection mode, the control unit controls the high frequency power supply to supply high frequency power to the divided electrodes facing a portion of the object to be heated, while the control unit controls the high frequency power supply not to supply high frequency power to the divided electrodes facing another portion of the object to be heated.

[0020] Next, the control unit controls the high frequency power supply not to supply high frequency power to the divided electrodes facing the part of the object to be heated, while controlling the control unit to supply high frequency power to the divided electrodes facing the other part of the object to be heated.

[0021] According to this aspect, switching between the protection mode and the normal mode is possible by changing the divided electrodes to which high-frequency power is supplied. In other words, switching between the protection mode and the normal mode can be easily performed without replacing the electrodes.

[0022] A high-frequency heating device according to a fourth aspect of the present disclosure further includes a position adjustment unit that adjusts the distance between the first electrode and the second electrode in addition to the first aspect. According to this aspect, the distance between the object to be heated and the electrodes can be set to an optimal value in the protection mode and the normal mode.

[0023] In a high-frequency heating device according to a fifth aspect of the present disclosure, in addition to the fourth aspect, in the protection mode, the position adjustment unit moves the first electrode farther from the object to be heated than in the normal mode. According to this aspect, it is possible to avoid local overheating of the object to be heated and to heat the entire object to be heated uniformly.

[0024] In a high-frequency heating device according to a sixth aspect of the present disclosure, in addition to the first aspect, in the protection mode, the control unit causes the high-frequency power source to generate high-frequency power with a lower heating output per unit time than in the normal mode. According to this aspect, overheating of the object to be heated can be suppressed in the protection mode.

[0025] In the protection mode, it is desirable to reduce the heating output for such objects compared to the normal mode, as this can easily cause local overheating in objects with a relatively low initial temperature or a relatively high height.

[0026] A seventh aspect of the present disclosure provides a high-frequency heating device according to the first aspect, further comprising a camera disposed in the heating chamber for capturing an image of the object to be heated. The control unit detects the dimensions of the object to be heated from the image of the object captured by the camera. According to this aspect, the control unit can set the range of the electrodes to which high-frequency power is supplied depending on the dimensions of the object to be heated.

[0027] A high-frequency heating device according to an eighth aspect of the present disclosure includes, in addition to the components of the first aspect, a temperature detection unit that detects the temperature of an object to be heated.

[0028] According to this aspect, when the object to be heated is a frozen product, the control unit can detect the temperature and approximate dimensions of the object to be heated. When the temperature detection unit detects a partial temperature rise in the object to be heated, the control unit can instruct the high-frequency power source to stop outputting high-frequency power or reduce the power level of the high-frequency power. As a result, partial overheating of the object to be heated can be suppressed.

[0029] A high-frequency heating device according to a ninth aspect of the present disclosure is, in addition to the first aspect, a normal mode selected by a user. or select protection mode According to this aspect, the high-frequency heating device can be set to either the protection mode or the normal mode at the discretion of the user.

[0030] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The X, Y, and Z axes shown in the drawings respectively indicate the width direction (left-right direction), depth direction (front-rear direction), and height direction (vertical direction) of the high-frequency heating device. That is, the right side of the high-frequency heating device is the positive direction of the X axis, the rear side of the high-frequency heating device is the positive direction of the Y axis, and the vertically upward direction of the high-frequency heating device is the positive direction of the Z axis.

[0031] (Embodiment 1) A high-frequency heating device 1A according to embodiment 1 of the present disclosure will be described below. Fig. 1 is a block diagram schematically showing the high-frequency heating device 1A according to embodiment 1.

[0032] As shown in FIG. 1, the high-frequency heating device 1A includes a first electrode 11A, a second electrode 12, a position adjustment unit 20, a high-frequency power supply 30, a matching unit 40, an operation unit 50, and a control unit 60.

[0033] The first electrode 11A and the second electrode 12 are flat electrodes parallel to the XY plane and arranged in the heating chamber 13. The first electrode 11A is arranged above the second electrode 12 so as to face the second electrode 12. Therefore, when the object to be heated 90 is placed on the second electrode 12, the object to be heated 90 is arranged between the first electrode 11A and the second electrode 12.

[0034] The control unit 60 controls the high frequency power supply 30. The high frequency power supply 30 is connected to the first electrode 11A via a matching unit 40, and is connected to the second electrode 12 directly.

[0035] The high-frequency power supply 30 generates high-frequency power and applies it between the first electrode 11A and the second electrode 12. This generates an electric field between the first electrode 11A and the second electrode 12. This electric field dielectrically heats the object 90 to be heated, which is placed between the first electrode 11A and the second electrode 12. The object 90 to be heated is a dielectric material, such as food material. In this way, the high-frequency heating device 1A performs a heating process or a thawing process on the object 90 to be heated.

[0036] In the first embodiment, the high-frequency power supply 30 supplies high-frequency power to both the first electrode 11A and the second electrode 12. However, the second electrode 12 may be grounded, and the high-frequency power supply 30 may supply high-frequency power only to the first electrode 11A. Conversely, the first electrode 11A may be grounded, and the high-frequency power supply 30 may supply high-frequency power only to the second electrode 12.

[0037] That is, the high frequency power supply 30 may supply high frequency power to either or both of the first electrode 11A and the second electrode 12.

[0038] 2 is a schematic diagram of the configuration of first electrode 11A in a plan view, that is, when viewed from above and below along the Z axis. As shown in FIG. 2, first electrode 11A includes divided electrodes 14A, 14B, 14C, and 14D.

[0039] The divided electrodes 14A to 14D are rectangular, flat electrodes arranged in order from the left. The control unit 60 controls the high-frequency power source 30 to supply high-frequency power separately to each of the divided electrodes 14A to 14D.

[0040] In the first embodiment, of the divided electrodes 14A to 14D, the divided electrode 14A has the largest area, and the divided electrodes 14B to 14D have approximately the same area. The divided electrodes 14B to 14D can be moved along the Z axis by the position adjustment unit 20.

[0041] The shape of the divided electrodes 14A to 14D is not limited to a rectangle, and the divided electrodes 14A to 14D may be a square, a circle including an oval, or a polygon other than a rectangle.

[0042] The second electrode 12 is a rectangular, flat electrode. The second electrode 12 is disposed opposite the first electrode 11A. In the first embodiment, the second electrode 12 is disposed below the first electrode 11A in the heating chamber 13. The second electrode 12 is not limited to a single electrode. Like the first electrode 11A, the second electrode 12 may be composed of multiple electrodes, and may have a square, a circle including an ellipse, or a polygon having five or more sides. The positions of the first electrode 11A and the second electrode 12 may be interchanged.

[0043] In the first embodiment, the position adjustment unit 20 adjusts the height of the first electrode 11A by moving the first electrode 11A up and down. This adjusts the distance between the first electrode 11A and the second electrode 12. However, the position adjustment unit 20 may move the second electrode 12 up and down instead of the first electrode 11A, or may move both the first electrode 11A and the second electrode 12 up and down.

[0044] The position adjustment unit 20 has, for example, a motor and a connection member that connects the motor to the first electrode 11A. The motor is disposed on the ceiling of the heating chamber 13. Rotation of the motor moves the connection member up and down, thereby moving the first electrode 11A up and down. The connection member may be, for example, a rod-shaped member or a wire. The control unit 60 controls the position adjustment unit 20.

[0045] The position adjustment unit 20 may be configured to move either or both of the first electrode 11A and the second electrode 12.

[0046] 6 is a schematic diagram of the high-frequency power supply 30. As shown in FIG. 6, the high-frequency power supply 30 includes a high-frequency oscillator 31, an amplifier 32, and an amplifier 33.

[0047] High frequency oscillator 31 oscillates and outputs a high frequency signal having a frequency in the HF to VHF bands. Amplifiers 32 and 33 amplify the high frequency signal transmitted from high frequency oscillator 31 to a desired power level. This enables high frequency power supply 30 to output high frequency power having a desired frequency and power level.

[0048] The matching unit 40 is connected between the first electrode 11A and the high-frequency power supply 30. The matching unit 40 matches the impedance of the high-frequency power supply 30 with the impedance inside the heating chamber 13 that contains the first electrode 11A, the second electrode 12, and the object 90 to be heated.

[0049] Fig. 7 is a schematic diagram of the matching unit 40. As shown in Fig. 7, the matching unit 40 includes a coil L1, a coil L2, a variable capacitor VC1, and a variable capacitor VC2. In the matching unit 40, the coil L1, the coil L2, and the variable capacitor VC2 are arranged in series, and the variable capacitor VC1 is arranged in parallel with the other elements.

[0050] The control unit 60 changes the capacitance of the variable capacitors VC1 and VC2, thereby causing the matching unit 40 to perform impedance matching.

[0051] 7 is an example, and the configuration of the matching section 40 is not limited to this. Furthermore, in the present disclosure, the matching section 40 is not an essential component.

[0052] The control unit 60 is electrically connected to the position adjustment unit 20, the high-frequency power supply 30, and the operation unit 50. The control unit 60 controls the position adjustment unit 20 and the high-frequency power supply 30 based on information input by the user via the operation unit 50.

[0053] Specifically, the information from the user includes the dimensions of the object to be heated 90 and the heating mode. Based on this information, the control unit 60 instructs the position adjustment unit 20 on the direction and amount of movement of the first electrode 11A, and instructs the high-frequency power source 30 on the frequency and power level of the high-frequency power. The control unit 60 adjusts the height of the first electrode 11A and the high-frequency power supplied to the first electrode 11A and the second electrode 12, thereby uniformly heating the object to be heated 90.

[0054] The operation and function of the high-frequency heating device 1A configured as above in the protection mode and normal mode will be described.

[0055] 3 is a schematic plan view showing the positional relationship between the object to be heated 90 and the first electrode 11A when viewed from above along the Z axis when a frozen meat block is heated in heating course A. Heating course A is one of the heating courses in the normal mode.

[0056] Figure 4 is a schematic plan view showing the positional relationship between the object to be heated 90 and the first electrode 11A when viewed from above along the Z axis when a frozen meat block is heated using heating course B. The dimensions of the frozen meat block shown in Figures 3 and 4 are 200 mm wide x 100 mm deep x 100 mm high. Heating course B is also one of the heating courses in the normal mode.

[0057] First, the user places the object to be heated 90 on a dedicated heating tray, and then places the heating tray on the second electrode. The user operates the power switch arranged on the operation unit 50 to turn on the high-frequency heating device 1A.

[0058] The user presses a button arranged on the operation unit 50 to select a heating course of the high-frequency heating device 1A. The heating courses include a normal mode heating course and a protection mode heating course. That is, the user selects the normal mode via the operation unit 50. or select protection mode After that, the user presses the start button arranged on the operation unit 50 to start heating.

[0059] Fig. 5 is a table listing the selectable heating courses in embodiment 1 and the operation of the high-frequency heating device 1A for each heating course. As shown in Fig. 5, for heating courses A and B, the object to be heated 90 is assumed to be a frozen meat block measuring 200 mm wide x 100 mm deep x 100 mm high. For heating courses C and D, the object to be heated 90 is assumed to be a frozen sashimi steak measuring 150 mm wide x 50 mm deep x 30 mm high.

[0060] The operation of the high-frequency heating device 1A when heating course A, which is the normal mode, is selected will be described below. Before operating the high-frequency heating device 1A, the user places a 20 mm thick heating tray on the second electrode, with frozen meat, which is the object to be heated 90, placed in the center. The thickness of this heating tray is 20 mm, and the distance between the object to be heated 90 and the second electrode is 20 mm.

[0061] When the button for selecting heating course A is pressed, the control unit 60 controls the position adjustment unit 20 to move the first electrode 11A so that the distance between the first electrode 11A and the second electrode 12 becomes 140 mm. Since the height of the object 90 to be heated is 100 mm and the thickness of the heating tray is 20 mm, the distance between the object 90 to be heated and the first electrode 11A is 20 mm.

[0062] Thereafter, control unit 60 controls high-frequency power supply 30 to output 500 W of high-frequency power for 10 minutes, with all of split electrodes 14A-14D of first electrode 11A included in the range of high-frequency power supply. After 10 minutes, control unit 60 notifies the user by voice and display that heating has ended, and ends heating.

[0063] After the predetermined heating is completed, the user may operate the operation unit 50 to continue heating depending on the state of the object to be heated 90. Using additional heating keys provided on the operation unit 50, the user may set the heating output, the distance between the electrodes, and the range of high-frequency power supply by the first electrode 11A.

[0064] Next, the operation of the high-frequency heating device 1A when heating course B, which is the protection mode, is selected will be described. The differences between heating course A and heating course B are the placement position of the object to be heated 90 on the dedicated tray, the range to which high-frequency power is supplied by first electrode 11A, the distance between the electrodes, the heating output, and the heating time. The user places the object to be heated 90 on the dedicated tray in the width direction, i.e., at the left end in the left-right direction and in the center in the depth direction.

[0065] 5, in heating course B, control unit 60 supplies high-frequency power only to split electrode 14A of split electrodes 14A to 14D. As a result, the range to which high-frequency power is supplied by first electrode 11A is 150 mm x 200 mm, which is smaller than in heating course A.

[0066] In this case, as shown in FIG. 4, most of the object 90 is covered with the split electrodes 14A. under However, portions of the object to be heated 90 up to 25 mm from both ends extend along the X axis beyond the split electrodes 14A to which high frequency power is supplied.

[0067] That is, in the protection mode, the divided electrode 14A to which high frequency power is supplied among the divided electrodes 14A to 14D is Under , a part of the object to be heated 90 Do not place In a plan view, the length of the split electrode 14A along the X axis is shorter than the length of the object to be heated 90 along the X axis.

[0068] In a plan view, of the four sides of the object to be heated 90, the two sides parallel to the Y axis are prone to overheating. However, as described above, by placing those sides outside the range facing the split electrode 14A to which high-frequency power is supplied, overheating can be suppressed.

[0069] That is, in the protection mode, the control unit 60 causes the high-frequency power supply 30 to supply high-frequency power to the split electrode 14A, of the split electrodes 14A to 14D, which faces a portion of the object 90. On the other hand, the control unit 60 causes the high-frequency power supply 30 not to supply high-frequency power to the split electrodes 14B to 14D, of the split electrodes 14A to 14D, which face other portions of the object 90.

[0070] 5, the distance between the first electrode 11A and the second electrode 12 is 160 mm, and the heating tray has a thickness of 20 mm, the same as in the normal mode. Therefore, the distance between the object to be heated 90 and the second electrode 12 is 20 mm. Since the distance between the electrodes is 160 mm, the height of the object to be heated 90 is 100 mm, and the thickness of the heating tray is 20 mm, the distance between the object to be heated 90 and the first electrode 11A is 40 mm.

[0071] In this state, the distance between the object to be heated 90 and the first electrode 11A is 20 mm greater than in the normal mode. This The electric field becomes stronger near the end of first electrode 11A to which high-frequency power is supplied. However, since the distance is greater than in the normal mode, local overheating near the end of first electrode 11A to which high-frequency power is supplied can be suppressed.

[0072] In the protection mode, the heating output is set to 250 W, which is lower than that in the normal mode, and the heating time is set to 20 minutes, which is longer than that in the normal mode. Thus, in the protection mode, high-frequency power with a lower heating output than in the normal mode is supplied for a longer period of time. In other words, in the protection mode, the heating output per unit time is lower than in the normal mode, which allows the heated object 90 to be heated more uniformly than in the normal mode.

[0073] Generally, a heating output of 250 W means continuously outputting a high-frequency power of 250 W. However, it is also possible to achieve a heating output of 250 W by intermittently outputting a high-frequency power greater than 250 W so that the time average is 250 W.

[0074] Next, the effects of heating the object 90 in the normal mode (heating courses A and C) and the protection mode (heating courses B and D) will be described. Fig. 8 shows the temperature distribution of the object 90 viewed from above (on the XY plane) when a frozen object 90 is thawed using heating courses A to D. The temperatures (°C) shown in the figure are the temperatures of the central part of the object 90 in the vertical direction.

[0075] The temperature distribution (a) in Figure 8 is the temperature distribution of frozen meat when thawed using heating course A, which heats the entire object to be heated 90. Heating course A is the normal mode, and heating course A thaws frozen meat measuring 200 mm wide x 100 mm deep x 100 mm high.

[0076] The temperature distribution (b) in Figure 8 is the temperature distribution of frozen meat when thawed using heating course B, which partially heats the object to be heated 90. Heating course B is also a normal mode, and the dimensions of the frozen meat are the same as those in heating course A. The temperature distribution (c) in Figure 8 is the temperature distribution when frozen sashimi with a temperature of -20°C and dimensions of 150 mm wide x 50 mm deep x 30 mm high is thawed using heating course C, which is a normal mode.

[0077] Temperature distribution (d) in Figure 8 is the temperature distribution when frozen sashimi with an initial temperature (-60°C) lower than that of a normal frozen product and the same dimensions as a normal frozen product is thawed using heating course D, which is the protection mode. Temperature distribution (e) in Figure 8 is the temperature distribution when frozen sashimi with a temperature of -60°C and dimensions of 150 mm wide x 50 mm deep x 30 mm high is thawed using heating course C. Temperature distribution (e) in Figure 8 is a comparative example for temperature distribution (d) in Figure 8.

[0078] As shown in the temperature distribution (a) in Figure 8, the temperature of the four corners of the frozen meat thawed using heating course A is higher than that of other parts, and the temperature of the center is lower than that of other parts. In this case, the frozen meat has not been heated enough to discolor and can be cut with a knife. In other words, the frozen meat has been thawed to the point where it can be cooked immediately.

[0079] As shown in the temperature distribution (b) of Figure 8, frozen meat thawed using heating course B is heated to a nearly uniform temperature throughout, making it easy to cut with a knife. The heating time for heating course B is longer than that for heating course A. However, heating course B makes it possible to thaw the entire object 90 uniformly while suppressing temperature increases at the four corners. Users can select which of these heating courses to use depending on their purpose.

[0080] As shown in the temperature distributions (c) and (d) in Figure 8, the frozen sashimi thawed using heating course C and heating course D was heated to a nearly uniform temperature and could be immediately cut with a knife.

[0081] However, as shown in the temperature distribution (e) in Figure 8, when frozen sashimi at -60°C is thawed using heating course C, the temperatures at the four corners rise considerably, but the temperature inside remains low. In other words, the frozen sashimi in this case is so hard that it is difficult to cut with a knife.

[0082] When stored at room temperature or in a refrigerator, frozen sashimi thaws as its temperature slowly passes through a temperature range known as the maximum ice crystal formation zone. As a result, the frozen sashimi is prone to dripping, potentially damaging its commercial value. The maximum ice crystal formation zone is the temperature range in which ice crystals are likely to grow during the freezing process, typically between -1°C and -5°C, at which food begins to freeze.

[0083] In addition, there is a large temperature difference between the inside and outside, so it takes time for the entire product to thaw. In the case of frozen products with low initial temperatures, it is easy for temperature differences to occur between the four corners and the center, so it is effective to heat them in a protection mode that can prevent the four corners from overheating.

[0084] The location where the object to be heated 90 should be placed may be indicated on the heating tray. The range of the first electrode 11A to which high-frequency power is supplied is changed depending on the size of the object to be heated 90. If the location where the object to be heated 90 should be placed is indicated on the heating tray, the user can easily place the object to be heated 90 in the correct position.

[0085] A heating tray having a thickness appropriate for each heating course may be prepared. A guide for placing the tray on the side wall of the heating chamber 13 may be provided so that the distance between the heating tray and the second electrode 12 is the desired distance. This allows the distance between the second electrode 12 and the object 90 to be appropriately adjusted, and the object 90 to be heated can be heated more uniformly.

[0086] In the first embodiment, the high-frequency heating device 1A has four heating courses, but the number of heating courses is not limited to this.

[0087] To add a heating course desired by the user, the control unit 60 may read the heating course from a storage medium such as a flash memory card, or may download the heating course via the Internet.

[0088] The operation unit is not limited to buttons. The operation unit may have a liquid crystal touch panel. A smartphone or the like may be used as the operation unit. The high-frequency heating device 1A may be operated by voice via a smartphone or the like.

[0089] (Embodiment 2) A high-frequency heating device 1B according to embodiment 2 of the present disclosure will be described. In embodiment 2, differences from embodiment 1 will be mainly described. In embodiment 2, the same reference numerals will be used to designate the same or equivalent configurations as in embodiment 1, and duplicate descriptions will be omitted.

[0090] Fig. 9 is a block diagram schematically showing a high-frequency heating apparatus 1B according to embodiment 2. As shown in Fig. 9, the high-frequency heating apparatus 1B includes a temperature detection unit 70 and a height detection unit 80. A control unit 60 controls the position adjustment unit 20 and the high-frequency power supply 30 based on information detected by the temperature detection unit 70 and the height detection unit 80.

[0091] The high-frequency heating device 1B has a first electrode 11B connected to a high-frequency power supply 30 via a matching unit 40, instead of the first electrode 11A. Similar to the first electrode 11A, the first electrode 11B is disposed in the heating chamber 13, faces the second electrode 12, and is a flat electrode parallel to the XY plane. The high-frequency power supply 30 applies high-frequency power between the first electrode 11B and the second electrode 12.

[0092] 10 is a schematic diagram of the configuration of first electrode 11B in a plan view, that is, when viewed from above along the Z axis. As shown in FIG. 10, first electrode 11B includes a plurality of flat electrodes arranged in a lattice pattern.

[0093] Specifically, the first electrode 11B includes 12 electrodes (divided electrodes 14E to 14P) arranged in 3 rows and 4 columns. Each divided electrode is formed in a square shape with one side measuring 5 cm. The divided electrode 14E is arranged at the left end of the innermost row. line In this example, split electrode 14F, split electrode 14G, and split electrode 14H are arranged in this order on the right side of split electrode 14E.

[0094] Segmented electrode 14I is arranged at the left end of the central row. In this row, segmented electrode 14J, segmented electrode 14K, and segmented electrode 14L are arranged in this order to the right of segmented electrode 14I. Segmented electrode 14M is arranged at the left end of the frontmost row. line In this example, split electrode 14N, split electrode 14O, and split electrode 14P are arranged in this order on the right side of split electrode 14M.

[0095] The number and arrangement of the split electrodes are not limited to this. Sixteen split electrodes may be arranged in a 4-row x 4-column grid. Multiple split electrodes may be arranged radially. The shape of the split electrodes 14E to 14P is not limited to a square. The split electrodes 14E to 14P may be rectangular, circular including oval, or polygonal other than rectangular.

[0096] The temperature detection unit 70 is installed at the center of the first electrode 11B. The temperature detection unit 70 has multiple infrared sensors and measures the temperature of the entire upper surface of the object to be heated 90. If the detected temperature is significantly different from the temperature of the heating chamber 13, the control unit 60 can also detect the size of the object to be heated 90 from the information from the temperature detection unit 70.

[0097] In the second embodiment, the control unit 60 performs heating in the normal mode when the temperature of the heated object 90 is −20° C. or higher, and performs heating in the protection mode when the temperature of the heated object 90 is below −20° C. As a result, even if the heated object 90 is a frozen product with an especially low temperature, heating in the protection mode prevents local overheating and allows the entire object to be heated uniformly.

[0098] The temperature detection unit 70 may have a plurality of infrared sensors arranged in a row. For example, when a plurality of infrared sensors are arranged in a row along the X axis, the temperature of the entire object to be heated 90 can be measured by swinging the temperature detection unit 70 around the X axis as the central axis. In order to measure the temperature of the entire object to be heated 90 at once, the temperature detection unit 70 may have a plurality of infrared sensors arranged in a grid pattern.

[0099] The height detection unit 80 is installed on the side wall surface of the heating chamber 13. The height detection unit 80 is a camera that captures an image of the object 90 to be heated along the X-axis or Y-axis. The control unit 60 calculates the height of the object 90 to be heated from the captured image. The height of the object 90 to be heated is the dimension of the object 90 along the Z-axis.

[0100] When the height of the object to be heated 90 is 60 mm or more, the control unit 60 causes the position adjustment unit 20 to adjust the distance between the object to be heated 90 and the first electrode 11B to 40 mm. When the height of the object to be heated 90 is 30 mm or more but less than 60 mm, the control unit 60 causes the position adjustment unit 20 to adjust the distance between the object to be heated 90 and the first electrode 11B to 30 mm. When the height of the object to be heated 90 is less than 30 mm, the control unit 60 causes the position adjustment unit 20 to adjust the distance between the object to be heated 90 and the first electrode 11B to 20 mm.

[0101] The height detection unit 80 may be a photoelectric tube or the like other than a camera. The user may input the height of the object 90 to be heated via the operation unit 50.

[0102] The control unit 60 may detect the dimensions (width, depth, height) of the object to be heated 90 from the captured image. The user may input the dimensions (width, depth, height) of the object to be heated 90 via the operation unit 50. Based on the dimensions (width, depth, height) of the object to be heated 90, the control unit 60 can determine, in the protection mode, the divided electrode to which high-frequency power is to be supplied, among the first electrode 11B (divided electrodes 14E to 14P).

[0103] In this way, the control unit 60 detects the dimensions (width, depth, height) of the object 90 to be heated from the captured image of the object 90. The control unit 60 determines to which divided electrodes high-frequency power is to be supplied according to the dimensions of the object 90. In other words, the control unit 60 sets the range of the electrodes to which high-frequency power is to be supplied.

[0104] The operation and function of the high-frequency heating device configured as above in the protection mode and normal mode will be described. Fig. 11 is a schematic plan view showing the positional relationship between the object to be heated 90 and the first electrode 11B when viewed from above along the Z axis.

[0105] 12 is a table showing selectable heating courses and the operation of the high-frequency heating device for each heating course in embodiment 2. The control unit 60 determines the heating course depending on the temperature and height of the object to be heated 90. The object to be heated 90 is frozen sashimi measuring 150 mm wide and 100 mm deep.

[0106] Here, it is assumed that the environment in which the high-frequency heating device 1B is used is 20°C, and that the object to be heated 90 is a frozen product. The control unit 60 determines the width and depth dimensions of the object to be heated 90 based on the range of negative temperatures detected by the temperature detection unit 70.

[0107] 12, for an object 90 having the same width and depth, the control unit 60 determines heating conditions according to the temperature and height of the object 90. For an object 90 having a temperature of -20°C or higher and a height of less than 30 mm, the control unit 60 determines heating conditions as follows: normal mode, full split electrodes, high heating output (1000 W), and short time (5 minutes).

[0108] When the height of the object to be heated 90 is 30 mm or more, the control unit 60 sets the heating mode to the protection mode. In the protection mode, the range of the first electrode 11B to which high-frequency power is supplied is narrower than that in the normal mode. In addition, the range is smaller than the object to be heated 90.

[0109] In the protection mode, as shown in Fig. 12, high-frequency power is supplied to split electrodes 14J and 14K (100 mm wide x 50 mm deep). As described above, the dimensions of the object to be heated 90 are 150 mm wide x 100 mm deep. Therefore, when the object to be heated 90 is placed at the center of first electrode 11B, each end of the object to be heated 90 in the width direction and the depth direction is placed 25 mm away from split electrodes 14J and 14K, as shown in Fig. 11.

[0110] In the protection mode, the control unit 60 moves the first electrode 11B farther from the second electrode 12, lowers the heating output, and sets a longer heating time compared to the normal mode as the height of the object 90 increases. In a plan view, the sides of the object that are perpendicular to the first electrode 11B are more likely to be overheated. However, by controlling the setting of the inter-electrode distance, heating output, and heating time as described above, the object 90 can be heated uniformly while preventing overheating.

[0111] A temperature below -20°C is lower than the temperature inside a typical freezer. When the temperature of the object 90 is below -20°C and the height of the object 90 is less than 20 mm, the heating mode is set to the normal mode. When the height of the object 90 is 20 mm or more, the heating mode is set to the protection mode.

[0112] That is, when the temperature of the object 90 is below -20°C, the heating mode is more likely to be set to the protection mode than when the temperature of the object 90 is -20°C or higher. Furthermore, the distance between the first electrode 11B and the object 90 is greater and the heating output is set lower than when the temperature of the object 90 is -20°C or higher. This allows the object 90 to be heated or thawed uniformly regardless of the temperature.

[0113] The electric field outside the heating range of first electrode 11B is weaker than that inside the heating range of first electrode 11B. Therefore, in the protection mode, the peripheral portion of object 90 is often heated less sufficiently than the center portion of object 90.

[0114] To solve this problem, heating may be performed by the split electrodes in contact with the peripheral portion of the object 90 after heating by the split electrodes in contact with the center of the object 90 is completed. As shown in Fig. 11, the center of the object 90 is heated by split electrodes 14J and 14K. The peripheral portion of the object 90 is heated by split electrodes 14E, 14F, 14G, 14H, 14I, 14L, 14M, 14N, 14O, and 14P.

[0115] In this way, after the center of the object 90 to be heated is heated to prevent the peripheral portion of the object 90 from being overheated, the peripheral portion of the object 90 to be heated can be heated in the same manner as the center portion.

[0116] That is, in the protection mode, the control unit 60 causes the high-frequency power supply 30 to supply high-frequency power to the divided electrodes facing a portion of the object 90. On the other hand, the control unit 60 does not cause the high-frequency power supply 30 to supply high-frequency power to the divided electrodes facing other portions of the object 90.

[0117] Next, the control unit 60 causes the high-frequency power supply 30 not to supply high-frequency power to the divided electrodes facing a portion of the object 90 to be heated. On the other hand, the control unit 60 causes the high-frequency power supply 30 to supply high-frequency power to the divided electrodes facing another portion of the object 90 to be heated.

[0118] Here, the divided electrodes facing a portion of the object 90 are divided electrodes 14J and 14K. The divided electrodes facing other portions of the object 90 are divided electrodes 14E, 14F, 14G, 14H, 14I, 14L, 14M, 14N, 14O, and 14P.

[0119] If the temperature detection unit 70 detects that the temperature of the object 90 has partially reached a predetermined value during heating in the normal mode or protection mode, the control unit 60 may reduce the heating output. Alternatively, the control unit 60 may stop heating for a certain period of time. This operation may be applied only to the divided electrodes corresponding to the portion of the object 90 whose temperature has risen, or to all divided electrodes. This prevents partial overheating and allows the entire object 90 to be heated uniformly.

[0120] In the second embodiment, the high-frequency power supply 30 supplies high-frequency power to both the first electrode 11B and the second electrode 12. However, the second electrode 12 may be grounded, and the high-frequency power supply 30 may supply high-frequency power only to the first electrode 11B. Conversely, the first electrode 11B may be grounded, and the high-frequency power supply 30 may supply high-frequency power only to the second electrode 12.

[0121] That is, the high frequency power supply 30 may supply high frequency power to either or both of the first electrode 11B and the second electrode 12. [Industrial Applicability]

[0122] As described above, the high-frequency heating device according to the present disclosure has a simple configuration and can uniformly heat objects of any shape. The high-frequency heating device according to the present disclosure can be applied to, for example, home cooking appliances such as thawing machines or cooking appliances, or drying devices for food ingredients or wood. [Explanation of symbols]

[0123] 1A, 1B High frequency heating device 11A, 11B 1st electrode 12 Second electrode 13 Heating chamber 14A, 14B, 14C, 14D, 14E, 14F, 14G, 14H, 14I, 14J, 14K, 14L, 14M, 14N, 14O, 14P split electrode 20 Position adjustment section 30 High frequency power supply 31 High-frequency oscillator 32, 33 Amplifier 40 Matching section 50 Control section 60 Control Unit 70 Temperature detection unit 80 Height detection unit 90 Heated object

Claims

1. A heating chamber; a first electrode disposed within the heating chamber; a second electrode disposed within the heating chamber and facing the first electrode; a radio frequency power source configured to generate radio frequency power; a control unit configured to control the high frequency power source, the control unit is configured to cause the high frequency power source to apply the high frequency power between the first electrode and the second electrode to control heating of an object to be heated placed between the first electrode and the second electrode; The control unit heats the entire object to be heated in a normal mode, and a protection mode for preventing local overheating of the object to be heated. the first electrode includes a plurality of segmented electrodes; In the protection mode, the control unit controls the high frequency power source to supply the high frequency power to the divided electrodes that face a part of the object to be heated, and not to supply the high frequency power to the divided electrodes that face another part of the object to be heated, Next, the control unit controls the high frequency power source not to supply the high frequency power to the divided electrodes facing the part of the object to be heated, but to supply the high frequency power to the divided electrodes facing the other part of the object to be heated. High frequency heating device.

2. A heating chamber; a first electrode disposed within the heating chamber; a second electrode disposed within the heating chamber and facing the first electrode; a position adjustment unit configured to adjust the distance between the first electrode and the second electrode; a radio frequency power source configured to generate radio frequency power; a control unit configured to control the high frequency power source, the control unit is configured to cause the high frequency power source to apply the high frequency power between the first electrode and the second electrode to control heating of an object to be heated placed between the first electrode and the second electrode; The control unit heats the entire object to be heated in a normal mode, and a protection mode for preventing local overheating of the object to be heated. In the protection mode, the position adjustment unit moves the first electrode farther from the object to be heated than in the normal mode. High frequency heating device.

3. A heating chamber; a first electrode disposed within the heating chamber; a second electrode disposed within the heating chamber and facing the first electrode; a radio frequency power source configured to generate radio frequency power; a control unit configured to control the high frequency power source, the control unit is configured to cause the high frequency power source to apply the high frequency power between the first electrode and the second electrode to control heating of an object to be heated placed between the first electrode and the second electrode; The control unit heats the entire object to be heated in a normal mode, and a protection mode for preventing local overheating of the object to be heated. In the protection mode, the control unit causes the high frequency power source to generate the high frequency power with a heating output per unit time that is smaller than that in the normal mode. High frequency heating device.

4. Further, a camera is provided in the heating chamber and configured to photograph the object to be heated, The high frequency heating device according to any one of claims 1 to 3, wherein the control unit detects the dimensions of the object to be heated from an image of the object to be heated taken by the camera.

5. The high frequency heating device according to any one of claims 1 to 3, further comprising a temperature detection unit configured to detect the temperature of the object to be heated.

6. The high-frequency heating device according to any one of claims 1 to 3, further comprising an operation unit configured to allow a user to input a selection of the normal mode or the protection mode.

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