JP6055735B2 - High frequency heating device - Google Patents

Description

  The present invention relates to a high-frequency heating apparatus that uses a rotating antenna to radiate microwave energy into a heating chamber to heat food and the like.

  The high-frequency heating device of Patent Document 1 includes a mounting base made of a dielectric material fixed to the bottom surface of a heating chamber, and a rotary antenna at the excitation opening portion of the waveguide provided at the center of the heating chamber ceiling. After the microwave energy to be guided is coupled to the rotating antenna, it is radiated from the rotating antenna into the heating chamber, and the food placed on the mounting table is heated at high frequency.

JP 2006-351220 A

  Claim 1 of Patent Document 1 states that “a heating chamber that accommodates an object to be heated, a high-frequency oscillator that supplies high-frequency energy to the heating chamber, and a high-frequency electromagnetic wave oscillated by the high-frequency oscillator is transmitted to the heating chamber. A wave tube, a rotating antenna that couples the waveguide and the heating chamber at a high frequency, an antenna driving shaft coupled to the rotating antenna, and a through hole provided in the waveguide that penetrates the antenna driving shaft. The antenna drive shaft includes a tip metal portion made of metal at the tip, and a dielectric portion made of a dielectric at the other portion, a female screw is cut in the tip metal portion, and the antenna drive shaft is screwed to the rotating antenna. A high-frequency heating device configured to be bonded to the substrate is disclosed.

  In paragraph 0027 of the cited document, “the rotating antenna vertical component 7 protrudes into the waveguide 4 and organically relates to the rotating antenna horizontal component 6 and emits high-frequency electromagnetic waves to the heating chamber 2. The antenna drive shaft 8 is connected to a rotation shaft 10 of a drive motor 9 by a connecting pin 11. The antenna drive shaft 8 has a tip metal portion 12 made of metal as a tip, and a tip metal. A portion other than the portion 12 is a dielectric portion 8a made of a dielectric, and a female screw is cut in the tip metal portion 12, and the rotating antenna 5 is joined to the antenna drive shaft 8 by fastening the screw 13 to the female screw portion. . " That is, the antenna drive shaft is connected to the rotation shaft of the drive motor provided outside the through-hole of the waveguide with a connection pin of unknown material, so that the antenna rotation shaft is suspended from the rotation shaft of the drive motor. The antenna rotation shaft has a tip metal portion made of metal at the tip, and a dielectric portion made of a dielectric other than the tip metal portion.

  The tip metal part and the rotating antenna are fixed with screws, and the rotating antenna and the antenna rotating shaft are joined. Thus, the rotating antenna is held by the drive motor, the rotational force of the drive motor is transmitted to the rotating antenna, and high-frequency energy is radiated into the heating chamber as the rotating antenna rotates.

  Furthermore, since the antenna drive shaft of Patent Document 1 is a dielectric except for its tip, if the hole diameter of the through hole of the waveguide is set to an appropriate size, high-frequency energy leaks out from the through hole. It describes that it can be suppressed.

  However, in general, a dielectric having a low dielectric constant such as Teflon (registered trademark) is used for the driving shaft of the antenna. However, in order to stably rotate the rotating antenna, it is perpendicular to the axial direction of the dielectric shaft. It is necessary to take a large outer dimension of the cross section. In addition, the structure in which the antenna dielectric shaft passes through the through-hole of the waveguide easily leaks radio waves. However, if the through-hole is made too small, the shaft is easily touched during rotation. As a result of problems such as electric discharge due to contact, it is difficult to reduce the outer dimension of the antenna dielectric axis.

  In a high-frequency heating apparatus such as a microwave oven, the outer diameter of the dielectric shaft of the rotating antenna is set to about 10 mm in consideration of the above-mentioned problems. Therefore, when the load in the heating chamber is small or no load is applied, There is a problem that microwave energy easily leaks to the outside through the gap between the hole and the antenna dielectric shaft or the antenna dielectric shaft itself.

  In order to solve the above-described problems, the present invention provides a heating chamber that accommodates an object to be heated, a magnetron that generates microwave energy, and the magnetron that is attached to the microwave chamber to transmit the microwave energy to the heating chamber. In a high-frequency heating apparatus comprising: a waveguide to be opened; an opening penetrating the heating chamber or the waveguide; and a dielectric shaft inserted into the opening. The outside of both the heating chamber and the waveguide The conductor pin is provided inside the dielectric shaft located at a position substantially perpendicular to the axial direction of the dielectric shaft and sandwiching the cross section of the central axis of the dielectric shaft.

  According to a second aspect of the present invention, there is provided a heating chamber for accommodating a heated object, a heated object placing plate made of a dielectric provided on a bottom surface of the heated chamber, and the heating chamber below the heated object placing plate. A high-frequency supply chamber provided in the substantially central portion of the bottom surface of the substrate, a magnetron for generating microwave energy, a waveguide for mounting the magnetron, a coupling hole provided in the central portion of the bottom surface of the high-frequency supply chamber, and the coupling hole penetrating therethrough Then, an inner conductor provided substantially vertically into the high-frequency supply chamber, a metal rotating antenna housed in the high-frequency supply chamber and connected to one end of the inner conductor, and a connection within the waveguide of the inner conductor A high-frequency heating apparatus comprising a dielectric shaft provided through the waveguide and a drive unit connected to one end of the dielectric shaft outside the waveguide; In the interior of the dielectric axis, substantially perpendicular to the axial direction of the dielectric axis, It is provided with a conductive pin with respect to the center axis cross-section of the dielectric axis.

  In the present invention, it is possible to suppress microwave energy leaking from a dielectric shaft provided penetrating the heating chamber or the waveguide. For this reason, malfunction of the electronic component arrange | positioned outside a heating chamber and a waveguide can be suppressed, and a high frequency heating apparatus can be operated stably. In addition, high input microwave energy can be supplied to the heating chamber via the waveguide, and the object to be heated stored in the heating chamber can be efficiently heated.

Longitudinal sectional view of the high-frequency heating device of Example 1 The principal part expansion longitudinal cross-sectional view of the high frequency electric power feeding port part of Example 1 The principal part expanded sectional view of the dielectric material shaft part of Example 1. Analysis result of attenuation effect with and without conductor pin of Example 1 Analytical model for determining the dimensions of each part of the conductor pin of Example 1 Analysis result of attenuation effect by axial length L of conductor pin of Example 1 Analysis result of damping effect by outer dimension D1 of cross section perpendicular to axial direction of conductor pin of example 1 The figure which showed how to take the axial length L in the dielectric material axis | shaft of the conductor pin of Example 1 The figure which showed how to take the outer dimension D1 in the dielectric material axis | shaft of the conductor pin of Example 1. The perspective view which showed an example of the shape of the conductor pin of Example 1. The figure which showed the outer dimension D1 of the cross section perpendicular | vertical to the axial direction of the conductor pin and dielectric material axis | shaft of Example 1. FIG. The perspective view of the conductor pin which provided the slit shape of Example 2. The longitudinal cross-sectional view of the high frequency heating apparatus provided with the weight sensor provided in the heating chamber bottom face of Example 3 The perspective view of the high frequency heating apparatus of Example 3.

  Hereinafter, embodiments of the high-frequency heating device of the present invention will be described by taking a microwave oven that heats an object to be heated by using a magnetron as an example, but a microwave oven provided with a heater and performing oven heating or grill heating is described. Or, a steam microwave oven with a boiler and steam heating may be used. In addition, the present invention can be applied to a waste disposal machine or the like as long as it is a space sealed with metal, that is, a structure in which microwave energy is supplied and heated in the resonator.

  1 is a longitudinal sectional view of the high-frequency heating device of Example 1, FIG. 2 is an enlarged perspective view of a high-frequency power supply port portion 100, FIG. 3 is an enlarged sectional view of a principal portion of a dielectric shaft portion, and FIG. FIG. 5 is an analysis model for determining the dimensions of each part of the conductor pin, FIG. 6 is an analysis result of the attenuation effect due to the axial length L of the conductor pin, and FIG. 7 is a cross section perpendicular to the axial direction of the conductor pin. FIG. 8 and FIG. 9 show how to determine the axial length L and the outer dimension D1 of the conductor pin in the antenna dielectric axis in the dielectric shaft with the built-in conductor pin. FIG. 11 is a perspective view showing an example of the shape of a conductor pin, and FIG. 11 is a view showing an outer dimension D1 of a cross section perpendicular to the axial direction of the conductor pin and the dielectric axis.

  As shown in FIG. 1, the high-frequency heating device of the present embodiment includes a heating chamber 1 that accommodates an object to be heated 11, an object mounting plate 2 that is a dielectric provided on the bottom surface of the heating chamber 1, and A high-frequency supply chamber 3 provided below the object placing plate 2, a magnetron 4 for generating microwave energy, a waveguide 5 to which the magnetron 4 is attached and transmitting microwave energy, and a waveguide In order to radiate the microwave energy guided to the tube 5 to the high-frequency supply chamber 3, a coupling hole 6 provided in the bottom surface (for example, the central portion) of the high-frequency supply chamber 3 and the coupling hole 6 pass through the inside of the high-frequency supply chamber 3. An inner conductor 7 provided substantially vertically to the metal, a metal rotating antenna 8 connected substantially horizontally to one end of the inner conductor 7 in the high-frequency supply chamber 3, and an inner conductor 7 connected in the waveguide 5. A dielectric shaft 9 and a drive unit 10 that rotationally drives the dielectric shaft 9 are provided. And, the rotation of the rotating antenna 8 is rotated controlled by a drive unit 10.

  Microwave energy generated by the magnetron 4 is guided to the waveguide 5 and propagated to the rotating antenna 8 by coaxial mode coupling with the inner conductor 7 penetrating the coupling hole 6, and the high-frequency supply chamber 3, the heated object mounting plate 2 radiates into the heating chamber 1. Here, the waveguide 5 that transmits the microwave energy forms a transmission path, and the high-frequency supply chamber 3 and the heating chamber 1 to which the microwave energy is supplied from the waveguide 5 through the inner conductor 7 constitute a resonator. .

  As shown in FIG. 2, the dielectric shaft 9 outside the waveguide 5 (on the drive unit 10 side) sandwiches the section of the central axis of the dielectric shaft substantially perpendicular to the rotation axis direction of the dielectric shaft 9. Thus, the conductor pin 12 is incorporated by, for example, insert molding. Here, “substantially perpendicular” means that the angle perpendicular to the axial direction of the dielectric shaft 9 is about 90 ° ± 10 °, and the shielding performance of this embodiment is maintained within this angle range. The position of the conductor pin 12 in the dielectric shaft 9 is preferably in the center of the shaft.

  In addition, when the axial length L of the conductor pin 12 shown in FIG. 3, the outer dimension D1 in the cross section orthogonal to the axial direction of the conductor pin 12, and the outer dimension D0 of the dielectric shaft 9, the conductor pin 12 is the conductor pin 12. The ratio L / D0 of the shaft length L to the outer dimension D0 of the dielectric shaft 9 is 0.58 ≦ L / D0 ≦ 1.12, and the outer dimension D1 and the dielectric in the cross section orthogonal to the axial direction of the conductor pin 12 A shape D1 / D0 of the outer dimension D0 of the body axis 9 was 0.08 ≦ D1 / D0 ≦ 0.52.

  The conductor pin 12 may be any metal as long as it is a conductor, but a conductor having a high conductivity is more desirable. The dielectric shaft 9 may be made of a high strength ceramic such as alumina when a load due to rotation is applied as in this embodiment.

  Next, the operation of the above configuration will be described. FIG. 4 shows an electromagnetic wave analysis of the effect of this embodiment based on the analysis model of FIG. 5 in which a dielectric shaft 9 is installed in the waveguide 5 based on the structure of FIG. 1 and a TE10 mode analysis signal is given in the Y-axis direction. It is calculated by.

  In the calculation, an electric field intensity observation point is placed at the axis center 5 mm away from the tip of the dielectric shaft 9 of the antenna outside the waveguide 5 shown in FIG. FIG. 4 shows the analysis result of the electric field strength of the leaked microwave energy depending on the presence or absence of the conductor pin 12.

  From FIG. 4, when the axial center of the distance S = 5 mm from the tip of the dielectric shaft 9 is an electric field intensity observation point, the configuration of the present embodiment in which the conductor pin 12 is provided in the frequency range of 2450 MHz to 2470 MHz is There is an attenuation effect of about −15 dB for the configuration without the pin 12. That is, in this embodiment, the microwave energy leaking to the outside of the waveguide 5 along the dielectric axis 9 in the form of surface waves can be suppressed. In the above analysis conditions, the material of the dielectric shaft 9 is alumina, and a dielectric constant εr ′ = 9.5 and a dielectric loss tangent tan δ = 0.0005, which are generally used physical properties, are used. Even with other dielectric materials, the effect of suppressing radio wave leakage can be obtained.

  FIG. 6 shows an analysis result of the attenuation effect by the axial length L of the conductor pin 12, and FIG. 7 shows an analysis result of the attenuation effect by the outer dimension D1 of the cross section perpendicular to the axial direction of the conductor pin 12.

  From this result, the shape of the conductor pin 12 effective in suppressing leakage of microwave energy is the ratio L / D0 between the axial length L of the conductor pin 12 and the outer dimension D0 of the cross section perpendicular to the axial direction of the dielectric shaft 9. However, 0.58 ≦ L / D0 ≦ 1.12, and the ratio D1 / D0 of the outer dimension D1 of the conductor pin 12 and the outer dimension D0 of the dielectric shaft 9 is 0.08 ≦ D1 / D0 ≦ 0.52. Yes, by using the conductor pin 12 having this shape, the microwave energy leaking to the outside of the waveguide 5 along the dielectric axis 9 can be suppressed. These analysis results show the attenuation effect in decibels (dB) based on the electric field intensity at the electric field intensity observation point 5 mm away from the tip of the dielectric shaft 9 when there is no conductor pin 12. These analyzes are ideal examples in which the conductor pin 12 is arranged at the center of the axial cross section of the dielectric shaft 9.

  In addition, although the conductor pin 12 shown in the present embodiment has a configuration in which insert molding is performed at the center of the axial section of the dielectric shaft 9, only the dielectric shaft 9 has a cross-sectional outer shape larger than that of the conductor pin 12 as shown in FIG. Even if it is the structure which provides a through-hole and inserts the conductor pin 12, it does not interfere. In addition, in this embodiment, even if the conductor pin 12 penetrates the dielectric shaft 9 and the shaft protrudes at both ends, the performance influence is small, and it goes without saying that the same effect can be obtained. However, it is more preferable to shorten the length L ′ of the extension portion 12a so that L / D0 ≦ 1.12. When protruding, it may protrude only on one side or on both sides. In production, it is easier to make one piece inserted into the shaft, one side is inside the shaft, and the other protrudes, and it is difficult to remove.

  Accordingly, the conductor pins 12 protruding from both ends of the dielectric shaft 9 may be deformed by bending, for example, fixed with an adhesive, or fixed in position using a separate fixing support. Moreover, it may be inserted into a hole provided in the dielectric shaft 9 and press-fitted, or both may be threaded and screwed. Alternatively, unevenness such as a groove may be provided on the outer surface of the conductor pin 12 so that the conductor pin 12 does not easily come out when inserted, or the conductor pin 12 may be made of a soft metal such as copper and embedded. Alternatively, it may be folded in two and fixed using a metal spring force.

In the case of the structure shown in FIG. 8, the length LL ′ in which the conductor pin 12 is built from the outer peripheral surface of the dielectric shaft 9 is preferably a length that passes through the center of the axial section of the dielectric shaft 9. On the other hand, the outer dimension D0 of the dielectric shaft 9 and the outer dimension D1 of the conductor pin 12 shown in this embodiment indicate the maximum outer dimensions of the cross section perpendicular to the axial direction. Therefore, for example, when the cross section perpendicular to the axial direction of the conductor pin 12 is a rectangular parallelepiped as shown in FIG. 9, the length of the diagonal line of the rectangular parallelepiped is the outer dimension D0. FIGS. 10A to 10D are perspective views showing examples of the shape of the conductor pin 12, and can be easily applied to any columnar shape such as a triangular prism, a quadrangular prism, or a cylinder.

  Here, FIGS. 11A to 11H are examples of how to take the outer dimensions D0 and D1 of the axial cross sections of the conductor pin 12 and the dielectric shaft 9, and the outer dimension is perpendicular to the axial direction of the conductor pin 12. FIG. Regardless of the cross-sectional shape, it is approximately the maximum length of two cross-sectional outlines. Therefore, the shape of the conductor pin 12 may be a cylindrical shape such as a cylinder instead of a columnar shape such as a column. Further, even when a dielectric shaft that does not rotate is inserted into the transmission line or the opening of the resonator, the above-described shape other than a cylinder may be used.

  In addition, in this embodiment, the present embodiment is applied to a rotating shaft on which the driving unit 10 rotates the rotating antenna 8. For example, for the standing wave control of the heating chamber 1, It goes without saying that the present invention can be easily applied to a structure in which a dielectric shaft is inserted by sliding or fixing in a resonator such as the waveguide 5 or a transmission line. With this configuration, the cross-sectional shape of the dielectric shaft can be made arbitrary as with the cross-sectional shape of the conductor pin 12.

  As described above, in the high-frequency heating device of the present embodiment, the conductor pin 12 is provided substantially perpendicular to the axial direction of the dielectric shaft 9 inside the dielectric shaft 9 protruding to the outside of the waveguide 5. Therefore, the microwave energy leaking to the outside of the waveguide 5 is suppressed, so that it is possible to prevent malfunction of the drive unit 10 connected to the dielectric shaft 9 and the electrical components and devices in the vicinity of the dielectric shaft, and a highly reliable high frequency There is an effect that a heating device can be provided.

  FIG. 12 shows another embodiment of the conductor pin 12 and is a perspective view of a structure in which a cylindrical conductor pin 12 is provided with a slit twisted in the axial direction or the axial direction. Here, the conductor pin 12 of this embodiment is connected to the dielectric shaft 9 inserted in the coupling hole 6 which is the opening of the waveguide 5 which is a transmission path and the heating chamber 1 which is a resonator, as in the first embodiment. Provided.

  The conductor pin 12 shown in FIG. 12A has a cylindrical structure with a cavity inside, and has a slit 13 parallel to the axial direction of the cylindrical conductor pin 12. If the gap between the slits 13 is extremely narrow, discharge (spark) is likely to occur. Therefore, it is necessary to provide the gap, for example, about 1 to 2 mm. In that case, the conductor pin 12 with the slit is regarded as a substantially cylinder in terms of radio waves.

  Further, the conductor pin 12 shown in FIG. 12B is provided with a slit 13 obliquely in the axial direction of the cylindrical conductor pin 12. Here, when the gap between the slits 13 is narrow as described above, the slits 13 may be provided at an arbitrary angle at which sufficient strength can be obtained, or may be spiral with respect to the axis, since they are cylindrical in terms of radio waves. . Also in this case, if the gap of the slit 13 is about 1 to 2 mm, for example, the conductor pin 12 with the slit 13 is considered to be almost cylindrical in terms of radio wave, and the axis of the conductor pin 12 that is the shape range of the first embodiment. The ratio L / D0 of the length L to the outer dimension D0 of the dielectric shaft 9 is 0.58 ≦ L / D0 ≦ 1.12, and the outer dimension D1 in the cross section perpendicular to the axial direction of the conductor pin 12 and the dielectric The shielding effect is obtained when the ratio D1 / D0 of the outer dimension D0 of the body axis 9 is 0.08 ≦ D1 / D0 ≦ 0.52.

  In the present embodiment, the temperature of the heating chamber 1 and the waveguide 5 becomes 100 ° C. or higher, and a difference in thermal expansion occurs between the dielectric shaft 9 and the conductor pin 12 as in the microwave oven capable of oven heating. The shape of the conductor pin 12 prevents the dielectric shaft 9 made of a hard material such as cracking or breaking. That is, the slit 13 of the conductor pin 12 can absorb the radial deformation due to the thermal expansion of the conductor pin 12 by the change of the slit gap. In addition, the slit 13 of the conductor pin 12 may be formed in a waveform, and the conductor pin 12 may be formed of a conductive elastic body.

  The conductor pin 12 of this embodiment has a structure in which at least one end of the conductor pin 12 protrudes from the dielectric shaft 9, or a structure in which the conductor pin 12 is inserted and fixed in a hole provided in the dielectric shaft 9, that is, The conductor pin 12 can be applied to a structure that can be freely deformed in the axial direction.

  FIGS. 13 and 14 are a longitudinal sectional view and a perspective view of a high-frequency heating apparatus including a weight sensor 14 provided on the bottom surface of the heating chamber according to the third embodiment. In this embodiment, the dielectric shaft 9-1 of the weight sensor 14 is heated from below so that the weight of the heated object 11 placed on the heated object placing plate 2 of the heating chamber 1 serving as a resonator can be detected. This is a structure in which the object to be heated placing plate 2 is supported at a plurality of positions by being inserted into an opening penetrating the chamber 1. Note that the high-frequency power supply port 100 of this embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

  In the figure, a heating chamber 1 for storing an object to be heated 11 and heating cooking is provided in the main body, and a door for taking in and out the object to be heated 11 is provided in front of the heating chamber 1. Below the bottom surface of the heating chamber 1, the rotating antenna 8 and the driving unit 10 that rotates the rotating antenna 8 are located at the substantially center position of the heated object mounting plate 2, and the weight sensor 14 is connected to the front side of the heated object mounting plate 2. There are a total of three locations, one at the corner and the other at the back.

  For example, the weight sensor 14 will be described with reference to an outline of detection means whose measurement principle is a capacitance type. In the capacitance type, two thin metal materials are arranged to face each other substantially in parallel to form a capacitor, and the thin metal material is formed according to the weight of the object to be heated 11 placed on the object to be heated placing plate 2. By changing the gap (capacitance) (not shown), the weight of the object to be heated 11 is calculated from the detection of the change in capacitance.

  That is, the weight sensor 14 directly detects a change in the weight of the object to be heated 11 placed on the object to be heated placing plate 2, and thus the dielectric shaft 9-1 disposed through the heating chamber 1. Thus, the heated object placing plate 2 and the weight sensor 14 (thin metal plate) are connected. In addition, if the structure which transmits the weight change of the to-be-heated material mounting board 2 with the dielectric material shaft 9-1, the weight detection means may not be an electrostatic capacitance type, for example, may be a distortion type. .

  The weight sensor 14 that holds the heated object placing plate 2 shown in FIG. 3 is weighted by the heated object placing plate 2 and the heated object 11 placed on the heated object placing plate 2. Can be accurately detected regardless of the placement position on the heated object placement plate 2.

  In this embodiment, the number of weight sensors 14 is three so that the dielectric shafts 9-1 of all the weight sensors 14 come into contact with the object-to-be-heated object mounting plate 2 and can be stably held. It is not necessary to limit the number to three as long as the object placing plate 2 can be stably held.

  Below the heating chamber 1, a high-frequency power feeding port portion 100 such as a magnetron 4, a waveguide 5, and a rotating antenna 8 is provided in order to supply microwaves for heating the object to be heated 11.

  The rotating antenna 8 is housed in the high-frequency supply chamber 3 below the heating chamber 1 and is configured to be covered with a mica plate 2-1 so as not to be touched by hand when the heated object placing plate 2 is removed. Here, since the mica plate 2-1 has a low dielectric loss characteristic with respect to the microwave, the electromagnetic wave energy that changes depending on the shape and the rotation speed of the rotating antenna 8 can be transmitted to the heating chamber 1 with minute attenuation.

  As described above, in this embodiment, the heating chamber 1 that houses the object to be heated 11, the object to be heated mounting plate 2 that is provided on the bottom surface of the heating chamber 1, and the object to be heated mounting plate 2 A dielectric shaft 9-1 that penetrates the bottom surface of the heating chamber 1 at the lower side and has one end in contact with the heated object mounting plate 2 and the other end provided outside the bottom surface of the heating chamber 1 and connected to the weight sensor 14, and heating A high-frequency supply chamber 3 provided at a substantially central portion of the bottom surface of the chamber 1, a magnetron 4 for generating microwave energy, a waveguide 5 to which the magnetron 4 is attached, and a coupling hole 6 provided at the central portion of the bottom surface of the high-frequency supply chamber 3. An inner conductor 7 that penetrates the coupling hole 6 and faces the high-frequency supply chamber 3 substantially vertically; a metal rotary antenna 8 that is housed in the high-frequency supply chamber 3 and connected to one end of the inner conductor 7; A dielectric shaft 9 connected through the waveguide 5 connected in the waveguide 5 of the inner conductor 7 and an induction A drive unit 10 connected to one end of the body axis 9 outside the waveguide 5 is provided, and the inside of the dielectric axis 9-1 protruding outside the bottom surface of the heating chamber 1 is substantially the same as the axial direction of the dielectric axis 9-1. It is the structure which provided the conductor pin 12-1 perpendicularly | vertically.

That is, in the high frequency heating apparatus of the present embodiment, by providing the conductor pin 12-1 substantially perpendicular to the axial direction of the dielectric shaft 9-1 inside the dielectric shaft 9-1 protruding outside the bottom surface of the heating chamber 1, Microwave energy leaking outside the heating chamber 1 along the dielectric axis 9-1 is suppressed. Therefore, similarly to the first embodiment, it is possible to prevent malfunction of the weight sensor 14 connected to the dielectric shaft 9-1 and the electrical components and devices in the vicinity of the dielectric shaft 9-1 and to provide a highly reliable high-frequency heating device. .
Furthermore, since leakage of microwave energy can be suppressed, input power in microwave heating can be improved, and the object to be heated in the heating chamber can be heated with high efficiency and in a short time. For example, in the case of a microwave oven, the maximum power in the input power during microwave heating can be improved and the maximum power can be maintained for a long time.

DESCRIPTION OF SYMBOLS 1 Heating chamber 2 To-be-heated object mounting board 2-1 Mica board 3 High frequency supply chamber 4 Magnetron 5 Waveguide 6 Coupling hole 7 Inner conductor 8 Rotating antenna 9, 9-1 dielectric shaft 10 Drive part 11 To-be-heated object 12 12-1 Conductor pin 13 Slit 14 Weight sensor 100 High-frequency power supply port

Claims (4)

A heating chamber for storing an object to be heated;
A magnetron that generates microwave energy;
A waveguide that attaches the magnetron and transmits the microwave energy to the heating chamber;
An opening penetrating the heating chamber or the waveguide;
A dielectric shaft inserted into the opening,
Inside the dielectric shaft located outside both the heating chamber and the waveguide, a conductor pin is sandwiched across the section of the central axis of the dielectric shaft substantially perpendicular to the axial direction of the dielectric shaft. Provided ,
The high frequency heating apparatus according to claim 1, wherein the conductor pin is provided with a slit parallel to the axial direction or obliquely in the axial direction . A heating chamber for storing an object to be heated;
A heated object mounting plate made of a dielectric provided on the bottom surface of the heating chamber;
A high-frequency supply chamber provided in a substantially central portion of the bottom surface of the heating chamber below the object placing plate,
A magnetron that generates microwave energy;
A waveguide for mounting the magnetron;
A coupling hole provided in the center of the bottom surface of the high-frequency supply chamber;
An inner conductor that passes through the coupling hole and faces the high-frequency supply chamber substantially vertically;
A metal rotating antenna housed in the high-frequency supply chamber and connected to one end of the inner conductor;
A dielectric shaft connected through the waveguide connected within the waveguide of the inner conductor;
A drive unit coupled to one end of the dielectric shaft outside the waveguide;
A conductor pin is provided inside the dielectric shaft outside the waveguide, with the central axis section of the dielectric shaft sandwiched substantially perpendicular to the axial direction of the dielectric shaft ,
The high frequency heating apparatus according to claim 1, wherein the conductor pin is provided with a slit parallel to the axial direction or obliquely in the axial direction . When the axial length L of the conductor pin, the outer dimension D1 in the cross section orthogonal to the axial direction of the conductor pin, the outer dimension D0 of the dielectric shaft,
The conductor pin is
The ratio L / D0 between the axial length L of the conductor pin and the outer dimension D0 of the dielectric shaft is 0.58 ≦ L / D0 ≦ 1.
. 12,
Ratio D1 / of the outer dimension D1 in the cross section perpendicular to the axial direction of the conductor pin and the outer dimension D0 of the dielectric shaft
3. The high frequency heating apparatus according to claim 1, wherein D0 satisfies 0.08 ≦ D1 / D0 ≦ 0.52. In any one of Claims 1-3,
A high-frequency heating apparatus, wherein the conductor pin is provided outside the waveguide.