JP4034321B2 - Microwave heating device - Google Patents

Description

  The present invention relates to a microwave heating apparatus, and more particularly, to a microwave heating apparatus that heats an object to be heated using microwaves, and in particular, to heat an object to be heated made of a thin-line metal. The present invention relates to a microwave heating apparatus suitable for use.

  Conventionally, induction heating is widely known as a method of heating a metal using high frequency.

  Here, FIG. 1 shows an explanatory diagram of the operation principle of induction heating. The operation principle of induction heating will be described below with reference to FIG.

That is, when the high frequency oscillator 12 is connected to the coil 10 and a high frequency current is passed through the coil 10 by the high frequency oscillator 12, the magnetic flux M is generated in the space on the inner diameter side of the coil 10. When the magnetic flux M passes through the heated body 14 made of a magnetic metal such as iron, an eddy current (induced current) _IE flows through the heated body 14. The eddy current _IE is concentrated near the surface of the heated body 14 due to the skin effect of the heated body 14 made of a magnetic metal. The penetration depth δ of the eddy current is expressed by the following equation (1). ).

δ = 503√ (ρ / μ _r F) (m) (1)
Here, mu _r is the relative permeability, [rho is the resistivity (Ω · m), F is the frequency (Hz).

  The principle of induction heating is based on the fact that eddy currents concentrated at the site of penetration depth δ cause resistance loss due to the resistivity specific to the heated object, which is called eddy current loss.

  Therefore, in induction heating, the frequency of the high-frequency current flowing through the coil and the high-frequency applied power are selected according to the material constant of the heated body, the dimensions of the heated body, the purpose of heating the heated body, or the heating temperature of the heated body. is doing. Note that the frequency of the high-frequency current flowing through the coil in induction heating is generally selected from 10 KHz to 200 KHz.

As described above, induction heating uses magnetic flux generated by passing a high-frequency current through the coil, but not all magnetic flux generated in the coil passes through the object to be heated. Actually, since there is a gap between the coil and the object to be heated, part of the magnetic flux leaks, causing a reduction in heating efficiency.

Here, FIG. 2 shows an equivalent circuit of induction heating. The power consumed by the heated body is the power consumed by the heated body = I ₂ ² × R ₂
, And the other hand, the power power coil consumes consumes coil = I ₁ ² × R _l
A is, in order to improve the heating efficiency is seen that must reduce the resistance R _l of the coil.

By the way, when the shape of the object to be heated is a linear elongated shape having a small diameter like a needle, in order not to reduce the heating efficiency, the coil wire diameter and diameter are reduced to reduce the magnetic flux. Leakage must be prevented.

However, when the coil small, so that the resistance R ₁ of the coil described in the above is increased, the eventually heating efficiency has been a possible thereby lowering.

  For these reasons, the following three problems have been pointed out regarding conventional induction heating.

    (1) When the object to be heated is very small with respect to the wire diameter and diameter of the coil, the leakage of magnetic flux increases and the heating efficiency decreases.

    (2) When the wire diameter and diameter of the coil are reduced, the resistance of the coil is increased and the heating efficiency is lowered.

    (3) If the object to be heated is small with respect to the penetration depth of the eddy current, the eddy current is limited, so the heating efficiency is lowered. For example, in the case of α-iron, which is a typical metal used for induction heating, a wire with a diameter of 0.6 mm is the limit of miniaturization of the object to be heated at a frequency of 100 KHz due to the influence of eddy current penetration depth. It is.

Note that the prior art that the applicant of the present application knows at the time of filing a patent application is not an invention related to a known literature invention, so there is no prior art document information to be described.

  The present invention has been made in view of the various problems of the prior art as described above, and the object of the present invention is, for example, a thin small diameter having a diameter of 0.6 mm or less. An object of the present invention is to provide a microwave heating apparatus capable of efficiently heating a linear object to be heated.

  In order to achieve the above object, the present invention heats a heated object by using Joule heat caused by resistance loss of the heated object by flowing a microwave conductive flow to the heated object. In this case, a microwave dielectric resonator is used, and the dielectric resonance mode is set to TM010 mode or TM01δ mode.

That is, the invention described in claim 1 of the present invention is a microwave heating apparatus using a microwave dielectric resonator that resonates in a specific resonance mode, and is a first device formed at the axial center portion of the upper surface portion. A cylindrical metal cover extending in the axial direction having one through hole and a second through hole formed in the axial center portion of the lower surface portion; and the first through hole disposed in the metal cover A microwave cavity having a dielectric cavity formed with a third through hole communicating with the second through hole and excited in a TM010 mode resonance mode; and the microwave dielectric resonance input means for inputting microwaves disposed vessel, generating a electromagnetic field components supplied by TM010 mode microwave input to the input means while being disposed in the microwave dielectric resonator TM01 And a mode electromagnetic field generating means, in which so as to heat the the heated material by placing the object to be heated in the second through hole.

The invention of claim 2 is the invention according to claim 1 of the present invention, the input means is a coaxial connector, the TM010-mode electromagnetic field generating means, a loop antenna It is what you have.

  The invention according to claim 3 of the present invention is the microwave generation means for inputting a microwave to the input means in the invention according to claim 1 or 2 of the present invention. And the microwave generation means includes frequency control means for always causing the oscillation frequency to follow the resonance frequency when the resonance frequency of the microwave dielectric resonator fluctuates.

  Moreover, invention of Claim 4 among this invention WHEREIN: In invention of any one of Claim 1, 2 or 3 among this invention, the said to-be-heated body is a metal wire or a needle-shaped metal piece. It is intended to be.

The invention according to claim 5 of the present invention is a microwave heating apparatus using a microwave dielectric resonator that resonates in a specific resonance mode . A cylindrical metal cover extending in the axial direction having one through hole and a second through hole formed in the axial center portion of the lower surface portion; and the first through hole disposed in the metal cover And a dielectric cavity formed with a third through hole communicating with the second through hole, the dielectric cavity having the first through hole, the second through hole, and the third through hole. Each having a support member that is supported in a hollow state in the metal cover so as to communicate with each other, and is disposed in the microwave dielectric resonator that is excited in a TM01δ mode resonance mode, and the microwave dielectric resonator. Input the set microwave Comprising input means, and a TM01δ mode electromagnetic field generating means for generating a electromagnetic field components supplied by TM01δ mode microwave input to the input means while being disposed in the microwave dielectric resonator, An object to be heated is disposed in the second through hole to heat the object to be heated.

The invention of claim 6 is the invention according to a fifth aspect of the present invention, the input means is a coaxial connector, the TM01δ mode electromagnetic field generating means, a loop antenna It is what you have.

  The invention according to claim 7 of the present invention is the microwave generation means for inputting a microwave to the input means in the invention according to any one of claims 5 or 6 of the present invention. And the microwave generation means includes frequency control means for always causing the oscillation frequency to follow the resonance frequency when the resonance frequency of the microwave dielectric resonator fluctuates.

  The invention according to claim 8 of the present invention is the invention according to any one of claims 5, 6 or 7 of the present invention, wherein the object to be heated is a metal wire or a needle-shaped metal piece. It is intended to be.

  Since the present invention is configured as described above, for example, a thin linear object to be heated having a small diameter such as 0.6 mm or less can be efficiently heated. Excellent effect.

  Hereinafter, an example of an embodiment of a microwave heating device according to the present invention will be described in detail with reference to the accompanying drawings.

  In the following description, the same or corresponding components are denoted by the same reference numerals, and the detailed configuration and operation thereof are omitted as appropriate.

First, in order to facilitate understanding of the microwave heating apparatus according to the present invention, a microwave dielectric resonator will be described.

  This microwave dielectric resonator is generally used by being incorporated in a communication device for the purpose of suppressing propagation of unwanted waves, and is classified by its resonance mode. In the microwave heating apparatus according to the present invention, the TM010 mode and the TM01δ mode are used as the resonance modes in order to realize the microwave heating.

  Here, FIG. 3 and FIGS. 4A and 4B are explanatory diagrams of the configuration of a TM010 mode microwave dielectric resonator generally used for communication. FIG. 3 is a perspective view. FIG. 4A is a configuration explanatory view, FIG. 4A is a configuration explanatory view taken along arrow A in FIG. 3, and FIG. 4B is a cross-sectional view taken along line BB in FIG.

  The microwave dielectric resonator 20 includes a cylindrical metal case 22 whose inside is hollow, and a cylindrical dielectric cavity 24 arranged coaxially in the metal case 22. Yes.

Further, in FIG. 3 and FIG. 4 (a) (b), reference numeral _{M 1} shown by the one-dot chain line shows the magnetic field component when is resonated in TM010 mode, also code _{E 1} indicated by the two-dot chain line in TM010 mode The electric field component when resonating is shown.

Next, FIG. 5 and FIGS. 6 (a) and 6 (b) are diagrams illustrating the configuration of a TM010 mode microwave dielectric resonator used in the microwave heating apparatus according to the present invention. FIG. FIG. 6A is a configuration explanatory view, FIG. 6A is a configuration explanatory view taken along arrow C in FIG. 5, and FIG. 6B is a cross-sectional view taken along line DD in FIG.

  The microwave dielectric resonator 30 has a through hole 22b formed in the central portion of the upper surface portion 22a of the metal case 22, and a through hole 22d formed in the central portion of the lower surface portion 22c of the metal case 22. The microwave dielectric resonator 20 is different from the above-described microwave dielectric resonator 20 in that the through hole 24a is formed along the axial direction in the central portion of the dielectric cavity 24 so as to communicate with the hole 22b and the through hole 22d.

The central portion of the TM010 mode dielectric cavity 24, the electric field component in the axial direction _{E 1} is only present. Accordingly, providing the dielectric cavity 24 with the through-hole 24a along the axial direction at the center portion is equivalent to reducing the relative dielectric constant of the dielectric cavity 24. Note that the same resonance frequency can be maintained by correcting the dimensions of the dielectric cavity 24.

Here, FIG. 7 shows an example of an embodiment of the microwave heating apparatus according to the present invention using the TM010 mode microwave dielectric resonator 30 described above.

This microwave heating apparatus 100 includes a microwave dielectric resonator 30, a coaxial connector 34 disposed on a side wall surface of a metal case 22 serving as a microwave input means, and a magnetic field component M2 in TM010 mode (indicated by a one-dot chain line in FIG. 7). and a loop antenna 36 connected to the coaxial connector 34 in the TM010 mode electromagnetic field generating means serving as a metal case 22 to generate a.) indicated by.

In the microwave heating apparatus 100, a predetermined microwave is guided to the microwave dielectric resonator 30 by a coaxial power supply line (not shown), and the microwave is injected into the microwave dielectric resonator 30 from the coaxial connector 34. By doing so, excitation in the resonance mode in the TM010 mode is performed. That is, by supplying a predetermined microwave from a coaxial feeder (not shown) to the loop antenna 36 via the coaxial connector 34, the magnetic field component M2 of TM010 mode (indicated by a one-dot chain line in FIG. 7) is coaxial. Generated by the loop antenna 36 connected to the connector 34 and coupled to the magnetic field component M1 of the dielectric cavity 24, excitation in the resonance mode in the TM010 mode is realized.

As described above, when the microwave dielectric resonator 30 of the microwave heating apparatus 100 is excited in the resonance mode of the TM010 mode, an electric field in the axial direction is placed in the through hole 24a of the microwave dielectric resonator 30. only component E ₂ will not be present.

  According to such a microwave heating apparatus 100, an object to be heated (not shown) positioned in the through hole 24 a can be efficiently heated by an action described later.

Next, FIGS. 8 and 9 (a) and 9 (b) are diagrams illustrating the principle configuration of a microwave dielectric resonator of TM01δ mode that is generally used for communication. FIG. 9A is an explanatory diagram illustrating a perspective principle configuration, FIG. 9A is a configuration explanatory diagram viewed from an arrow E in FIG. 8, and FIG. 9B is a cross-sectional view taken along line FF in FIG.

  The microwave dielectric resonator 40 includes a metal case 22 that is hollow inside, and is disposed coaxially in the metal case 22 and is spaced apart from the upper surface portion 22a and the lower surface portion 22c of the metal case 22. And a cylindrical dielectric cavity 42 arranged in a floating state.

Further, in FIG. 8 and FIG. 9 (a) (b), reference numeral _{M 3} indicated by a dashed line shows the magnetic field component when is resonated in TM01δ mode, also code _{E 3} indicated by the two-dot chain line in TM01δ mode The electric field component when resonating is shown.

Next, FIG. 10 and FIGS. 11 (a) and 11 (b) are diagrams for explaining the principle configuration of the TM01δ mode microwave dielectric resonator used in the microwave heating apparatus according to the present invention. FIG. 11A is a diagram illustrating a front perspective principle configuration, FIG. 11A is a diagram illustrating a configuration viewed from an arrow G in FIG. 10, and FIG. 11B is a cross-sectional view taken along line HH in FIG.

  This microwave dielectric resonator 50 is different from the above microwave dielectric resonator 40 only in that the dielectric cavity 42 is provided with a through hole 42a along the axial direction in the central portion.

The central portion of the dielectric cavity 42 of TM01δ mode, electric field component in the axial direction E ₃ there is only. Accordingly, providing the dielectric cavity 42 with the through hole 42a along the axial direction at the center portion is equivalent to reducing the relative dielectric constant of the dielectric cavity 42. Note that the same resonance frequency can be maintained by correcting the dimensions of the dielectric cavity 42.

Next, FIGS. 12 and 13 (a) and 13 (b) show more detailed configuration explanatory diagrams of the TM01δ mode microwave dielectric resonator used in the microwave heating apparatus according to the present invention. 12 is a front perspective configuration explanatory view, FIG. 13A is a configuration explanatory view taken along arrow I in FIG. 12, and FIG. 13B is a cross-sectional view taken along line JJ in FIG.

  The microwave dielectric resonator 60 uses a metal case 22 having a through hole 22b formed in the central portion of the upper surface portion 22a and a through hole 22d formed in the central portion of the lower surface portion 22c. . Further, in order to dispose the dielectric cavity 42 so as to be separated from the upper surface portion 22a and the lower surface portion 22c of the metal case 22 and float in a hollow state, the dielectric cavity 42 is located coaxially with the through hole 22b formed in the upper surface portion 22a and communicates with each other. A donut-shaped cylindrical first dielectric cavity support member 62 having a through hole 62a formed coaxially is disposed on the upper surface portion 22a in the metal case 22, and a through hole 22d formed in the lower surface portion 22c. The donut-shaped cylindrical second dielectric cavity support member 64, which is coaxially formed with the through-holes 64a coaxially formed with each other, is disposed on the lower surface portion 22c in the metal case 22 in the above. Different from the microwave dielectric resonator 50.

  In the microwave dielectric resonator 60, the dielectric cavity 42 is disposed between the first dielectric cavity support member 62 and the second dielectric cavity support member 64, and the first dielectric cavity support member 62 and the first dielectric cavity support member 62. The dielectric cavity 42 is supported in the hollow inside the metal case 22 by the two dielectric cavity support members 64.

  Here, the material is selected so that the relative dielectric constant of the first dielectric cavity support member 62 and the second dielectric cavity support member 64 is about 1/5 to 1/10 of that of the dielectric cavity 42. By doing so, each dimension of the microwave dielectric resonator 60 can be corrected to maintain the TM01δ resonance frequency.

Here, FIG. 14 shows an example of an embodiment of the microwave heating apparatus according to the present invention using the TM01δ mode microwave dielectric resonator 60 described above.

This microwave heating apparatus 200 includes a microwave dielectric resonator 60, a coaxial connector 66 disposed on a side wall surface of a metal case 22 serving as a microwave input means, and a magnetic field component M4 in TM01δ mode (indicated by a one-dot chain line in FIG. 14). and a loop antenna 68 connected to the coaxial connector 66 in the TM01δ mode electromagnetic field generating means serving as a metal case 22 to generate a.) indicated by.

In the microwave heating apparatus 200, a predetermined microwave is guided to the microwave dielectric resonator 60 by a coaxial feeder (not shown), and the microwave is injected into the microwave dielectric resonator 60 from the coaxial connector 66. By doing so, excitation by the resonance mode in the TM01δ mode is performed. That is, by supplying a predetermined microwave from a coaxial power supply line (not shown) to the loop antenna 68 via the coaxial connector 66, the magnetic field component M4 of the TM01δ mode (indicated by a one-dot chain line in FIG. 14) is coaxial. It is generated by the loop antenna 68 connected to the connector 66 and coupled to the magnetic field component M3 of the dielectric cavity 42 to realize excitation in the resonance mode in the TM01δ mode.

As described above, when the microwave dielectric resonator 60 of the microwave heating apparatus 200 is excited in the resonance mode of the TM01δ mode, an electric field in the axial direction is placed in the through hole 42a of the microwave dielectric resonator 60. only component E ₃ will be absent.

  According to such a microwave heating apparatus 200, a heated object (not shown) located in the through hole 42a can be efficiently heated by an action described later.

Next, the heating action by the microwave heating apparatus 200 described above will be described in more detail with reference to FIG. In FIG. 15, the object to be heated 300 made of a thin metal wire with a small diameter (in FIG. 15, shown by a thick solid line for better visibility) is obtained by the microwave heating apparatus 200. The case of heating is shown.

  First, a through hole 22b formed in the upper surface portion 22a of the metal case 22 formed coaxially with each other, a through hole 62a in the first dielectric cavity support member 62, a through hole 42a in the dielectric cavity 42, a first The heated object 300 made of a metal wire is disposed so as to sequentially pass through the through hole 64a of the two dielectric cavity support member 64 and the through hole 22d formed in the lower surface portion 22c of the metal case 22.

Here, when the microwave heating device 200 is excited to resonate with the TM01δ mode, the displacement current _Ia and the displacement current _Ib flow inside the dielectric cavity 42. Meanwhile, since the magnetic field components M ₃ of TM01δ mode is stable distribution around the object to be heated 300, the direction perpendicular to the magnetic field components M _3, i.e., the surface current flows in a direction which coincides with the axial direction of the object to be heated 300 .

  This surface current has a skin effect, and the penetration depth follows the formula (1). However, since the frequency F is a microwave, the penetration depth is about several μm. Even when the thickness is about 100 μm, the surface current flows without any problem.

Such a surface current causes a power loss due to a surface resistance when flowing through the heated object 300. Equation (2) shows the relationship between the power loss density P _c , the surface resistance R _s, and the magnetic field H.

P _c = | H | ² R _s Formula (2)

Unlike the eddy current in induction heating, the surface current described above flows to the conductor surface regardless of the distinction between magnetic and nonmagnetic materials, and causes the effect of heating the conductor.

  Further, since the surface current flows regardless of the Curie point, the power loss increases following the applied microwave power, so that a desired heating temperature can be easily set.

Next, referring to FIG. 16, a heating action when a microwave heating apparatus 200 heats a heated object 302 made of a thin metal wire having a small diameter and a short length. Will be described.

  First, a heated body 302 made of a needle-like metal wire (shown by a thick solid line in FIG. 16 for better visibility) is provided at the approximate center position of the through hole 42a of the dielectric cavity 42. It arrange | positions so that a direction may correspond with the axial direction of the through-hole 42a.

Here, when the microwave heating device 200 is excited to resonate with the TM01δ mode, the displacement current _Ia and the displacement current _Ib flow inside the dielectric cavity 42. On the other hand, since the magnetic field component M ₃ in the TM01δ mode is stably distributed around the heated body 302, the surface current flows in a direction orthogonal to the magnetic field component M ₃ , that is, a direction that coincides with the axial direction of the heated body 302. The heated body 302 is heated by the same action as the heating of the heated body 300.

The microwave heating device 100 using the microwave dielectric resonator 40 of the TM010 mode whose magnetic field component with respect to the object to be heated is equivalent to the TM01δ mode also uses the microwave dielectric resonator 60 of the TM01δ mode. The object to be heated can be heated by the same action as the action of microwave heating by the microwave heating apparatus 200.

In addition, when a heated object is inserted into the TM010 mode microwave dielectric resonator 40 or the TM01δ mode microwave dielectric resonator 60, the electromagnetic field distribution around the dielectric cavities 24 and 42 changes. Therefore, the resonance frequency varies. At that time, if the frequency of the microwave oscillation device that supplies the microwaves to the microwave dielectric resonators 40 and 60 is controlled so that the resonance frequency is always maintained, the microwaves are in a matched state in the dielectric cavity. Since it is injected into 24 and 42, high-efficiency microwave heating can be realized.

  Control of the frequency of such a microwave oscillator is performed by, for example, detecting the reflected power of the microwave injected into the microwave dielectric resonators 40 and 60 so that the reflected power is minimized. This can be realized by adding a means for achieving an automatic frequency control function (AFC (Automatic Frequency Control) function) for feedback control to the microwave oscillation device.

  Hereinafter, the microwave heating apparatus 400, which is a system in which microwaves are supplied to the microwave heating apparatuses 100 and 200 by the microwave oscillation apparatus including the feedback control system described above, will be described.

  That is, FIG. 17 shows a configuration explanatory diagram of the microwave heating apparatus 400. The microwave heating apparatus 400 is for heating a needle-shaped metal piece, specifically, a used injection needle 402 as an object to be heated, and is intended for high-temperature sterilization of the used injection needle 402. is there. The material of the used injection needle 402 is non-magnetic stainless steel.

  The microwave heating apparatus 400 includes a microwave heating apparatus 200, a microwave oscillation apparatus 404 that supplies a microwave to the microwave heating apparatus 200, a used injection needle tray 406 that contains a used injection needle 402, and a use The first conveyance path 408 for conveying the used injection needle 402 disposed between the used injection needle tray 406 and the microwave heating apparatus 200 and accommodated in the used injection needle tray 406 to the microwave heating apparatus 200. An air control device 410 for generating an air flow in the first conveyance path 408, a second conveyance path 412 for conveying the used injection needle 402 heated by the microwave heating apparatus 200 and sterilized at a high temperature, It has a processed tray 414 for storing a high-temperature sterilized used injection needle 402 that has been transported through the second transport path 412. To have.

  The microwave oscillation device 404 includes a detection unit 402a for detecting reflected power from the microwave dielectric resonator 60, and an automatic frequency control unit 402b that performs processing based on the detection voltage output from the detection unit 402a. , A PLL frequency synthesizer 402c, a transmission power monitor unit 402d, an attenuator 402e, and an amplifier 402f.

In the above configuration, the used injection needle 402 guided to the first transport path 408 using the air flow controlled by the air control device 410 from the used injection needle tray 406 is a microwave dielectric resonance of TM01δ mode. To a microwave heating device 200 equipped with a vessel 60.

  The used injection needle 402 sent to the microwave heating apparatus 200 is disposed in the through hole 42a of the microwave dielectric resonator 60 serving as a heating unit, and the used injection needle disposed in the through hole 42a. A surface current caused by a resonant magnetic field flows through 402, and Joule heat is generated due to power loss caused by surface resistance. In this way, the used injection needle 402 is heated to about 1000 ° C., and a high temperature sterilization process is performed to kill all the bacteria mixed in the blood.

  The used injection needles 402 that have been subjected to high-temperature sterilization as described above are collected in the processed tray 414 via the second transport path 412 and disposed of.

  Next, the microwave oscillation device 404 disposed in the microwave heating device 200 will be described.

  The microwave oscillation device 404 is connected to a coaxial connector 66 that is a microwave injection terminal of the microwave dielectric resonator 60 in the TM01δ mode microwave heating device 200.

  Here, the microwave oscillation device 404 is provided with a detection unit 402a for detecting the reflected power from the microwave dielectric resonator 60, and the level of the reflected power is converted into a DC voltage by the detection unit 402a. The This detected voltage is guided to the automatic frequency control circuit 402b via the signal line, compared, and converted to a setting signal having a resonance frequency that minimizes the reflected power, and is guided to the PLL frequency synthesizer 402c via the signal line. . By such a control operation, the resonance frequency state is always maintained regardless of whether or not the used injection needle 402 as the heated body is present in the through hole 42a as the heating portion of the microwave dielectric resonator 60 in the TM01δ mode. can do.

  In the microwave heating apparatus 400, 2.45 GHz that is open as an ISM band was used as the resonance frequency of the microwave dielectric resonator 60.

Therefore, according to the microwave heating apparatus 100, 200, 400 according to the present invention using the TM010 mode or TM01δ mode microwave dielectric resonators 40, 60, the above-described problems of the conventional techniques can be solved.

That is, according to the microwave heating apparatus 100, 200, 400 according to the present invention,
(1) It is possible to heat a linear object to be heated of 0.1 mm or less,
(2) It is possible to heat even a needle-like object to be heated of 0.1 mm or less.
(3) When a microwave oscillation device having an automatic frequency control function is used, the heating operation is performed following the resonance frequency of the microwave dielectric resonators 40 and 60, so that the heating efficiency can be improved. ,
An excellent effect is obtained.

The above-described embodiment can be modified as shown in the following (1) to (6).

  (1) In the above-described embodiment, the used injection needle is specifically shown as the heated body. However, the heated body is not limited to this, and it is a conductor. Various forms and materials can be heated.

  (2) In the above-described embodiment, only an example of a method for automatically controlling the frequency of the microwave oscillation device is shown, and the frequency of the microwave oscillation device is automatically controlled by an appropriate method. Of course, the automatic frequency control function may be realized.

  (3) In the above-described embodiment, the metal case is configured by a cylindrical shape having a hollow inside. However, the shape of the metal case is not limited to this, and depending on the application. Any shape such as a prismatic shape made hollow can be selected and used.

  (4) In the above-described embodiment, the dielectric cavities 24 and 42 are configured by a donut shape in which a through hole is formed in the center of a cylindrical shape. However, the shape of the dielectric cavities 24 and 42 is not limited thereto. Of course, the outer shape may be a prismatic shape, and the shape of the through holes 24a and 42a may be a round hole or a square hole.

  (5) In the above-described embodiment, the first dielectric cavity support member 62 and the second dielectric cavity support member 64 are formed in a donut-shaped cylindrical shape. However, the first dielectric cavity support member 62 and the second dielectric cavity support member 62 Of course, the shape of the dielectric cavity support member 64 is not limited to this, and the outer shape may be a prismatic shape, and the through holes 62a and 64a may be round holes. It may be a square hole or a shape in which the through holes 62a and 64a are not provided, that is, it may not be a cylindrical shape.

  (6) You may make it combine the above-mentioned embodiment and the modification shown in above-mentioned (1)-(5) suitably.

  The present invention relates to a thin linear heated object having a small diameter, for example, a linear heated object having a diameter of 0.6 mm or less and a diameter of 0.1 mm or less like a used injection needle. It can be used when heating.

FIG. 1 is an explanatory diagram of the operation principle of induction heating. FIG. 2 is an equivalent circuit of induction heating. FIG. 3 is a perspective view illustrating a TM010 mode microwave dielectric resonator that is generally used for communication. 4A is an explanatory diagram of the configuration of the arrow A in FIG. 3, and FIG. 4B is a cross-sectional view taken along line BB in FIG. 4A. FIG. 5 is a perspective view illustrating a TM010 mode microwave dielectric resonator used in the microwave heating apparatus according to the present invention. 6A is an explanatory diagram of the configuration of the arrow C in FIG. 5, and FIG. 6B is a cross-sectional view taken along the line DD in FIG. 6A. FIG. 7 is a perspective configuration explanatory view showing an example of an embodiment of a microwave heating apparatus according to the present invention using the TM010 mode microwave dielectric resonator shown in FIGS. 5 and 6A and 6B. . FIG. 8 is a perspective explanatory view of a TM01δ mode microwave dielectric resonator generally used for communication. FIG. 9A is an explanatory diagram of the configuration of the arrow E in FIG. 8, and FIG. 9B is a cross-sectional view taken along the line FF in FIG. 8A. FIG. 10 is a front perspective principle explanatory diagram of a TM01δ mode microwave dielectric resonator used in the microwave heating apparatus according to the present invention. FIG. 11A is an explanatory diagram of the configuration of the arrow G in FIG. 10, and FIG. 11B is a cross-sectional view taken along the line HH in FIG. FIG. 12 is a more detailed front perspective view of the TM01δ mode microwave dielectric resonator used in the microwave heating apparatus according to the present invention. FIG. 13A is an explanatory diagram of the configuration of the arrow I in FIG. 12, and FIG. 13B is a cross-sectional view taken along line JJ in FIG. FIG. 14 is a front perspective structural explanatory view showing an example of the embodiment of the microwave heating apparatus according to the present invention using the TM01δ mode microwave dielectric resonator shown in FIG. 12 and FIGS. 13 (a) and 13 (b). is there. FIG. 15 is an explanatory view of a heating action when a heated object made of a thin metal wire having a small diameter is heated by the microwave heating apparatus according to the present invention shown in FIG. FIG. 16 is a diagram for explaining the heating action when heating the object to be heated, which is a thin metal wire having a small diameter and having a short length, by the microwave heating apparatus according to the present invention shown in FIG. FIG. FIG. 17 is a configuration explanatory diagram of an example of an embodiment of a microwave heating apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Coil 12 High frequency oscillator 14 Heated object 20 Microwave dielectric resonator 22 Metal case 22a Upper surface part 22b Through-hole 22c Lower surface part 22d Through-hole 24 Dielectric cavity 24a Through-hole 30 Microwave dielectric resonator 34 Coaxial connector 36 Loop Antenna 40 Microwave dielectric resonator 42 Dielectric cavity 42a Through hole 50 Microwave dielectric resonator 60 Microwave dielectric resonator 62 First cylindrical dielectric cavity support member 62a Through hole 64 Second cylindrical dielectric cavity Support member 64a Through-hole 66 Coaxial connector 68 Loop antenna 100 Microwave heating device 200 Microwave heating device 300 Heated body 302 Heated body 400 Microwave heating device 402 Used injection needle 402a Detection unit 402b Automatic frequency control unit 4 2c PLL frequency synthesizer 402d transmission power monitoring unit 402e attenuator 402f amplifier 404 microwave oscillator 406 used needle tray 408 first conveying path 410 air control device 412 the second transport path 414 processed tray

Claims (8)

A microwave heating apparatus using a microwave dielectric resonator that resonates in a specific resonance mode,
A cylindrical metal cover extending in the axial direction having a first through hole formed in the axial center portion of the upper surface portion and a second through hole formed in the axial center portion of the lower surface portion, and in the metal cover And a dielectric cavity formed with a third through-hole communicating with the first through-hole and the second through-hole and excited in a TM010 mode resonance mode A body resonator,
Input means for inputting microwaves disposed in the microwave dielectric resonator;
And a TM010 mode electromagnetic field generating means for generating the microwave electric field component of the feed has been TM010 mode microwave input to the input means while being disposed in the dielectric resonator,
A microwave heating apparatus, wherein an object to be heated is disposed in the second through hole to heat the object to be heated. In the microwave heating device according to claim 1,
The input means is a coaxial connector;
The TM010 mode electromagnetic field generating means, a microwave heating apparatus which is a loop antenna. The microwave heating apparatus according to claim 1, further comprising:
Microwave generation means for inputting a microwave to the input means,
The microwave heating apparatus, wherein the microwave generation means includes frequency control means for causing the oscillation frequency to always follow the resonance frequency when the resonance frequency of the microwave dielectric resonator fluctuates. In the microwave heating device according to any one of claims 1, 2, or 3,
The microwave heating apparatus, wherein the object to be heated is a metal wire or a needle-like metal piece. A microwave heating apparatus using a microwave dielectric resonator that resonates in a specific resonance mode,
A cylindrical metal cover extending in the axial direction having a first through hole formed in the axial center portion of the upper surface portion and a second through hole formed in the axial center portion of the lower surface portion, and in the metal cover And a dielectric cavity formed with a third through hole communicating with the first through hole and the second through hole, and the dielectric cavity through the first through hole and the second through hole. A microwave dielectric resonator having a support member that is supported in a hollow state in the metal cover so that the through hole and the third through hole communicate with each other, and is excited in a resonance mode of TM01δ mode When,
Input means for inputting microwaves disposed in the microwave dielectric resonator;
And a TM01δ mode electromagnetic field generating means for generating said microwave dielectric resonator microwave input to the input means while being arranged supplied to electric field components of TM01δ mode,
A microwave heating apparatus, wherein an object to be heated is disposed in the second through hole to heat the object to be heated. In the microwave heating device according to claim 5,
The input means is a coaxial connector;
The TM01δ mode electromagnetic field generating means, a microwave heating apparatus which is a loop antenna. The microwave heating apparatus according to any one of claims 5 and 6, further comprising:
Microwave generation means for inputting a microwave to the input means,
The microwave heating device, wherein the microwave generation means includes frequency control means for causing the oscillation frequency to always follow the resonance frequency when the resonance frequency of the microwave dielectric resonator fluctuates. In the microwave heating device according to any one of claims 5, 6 and 7,
The microwave heating apparatus, wherein the object to be heated is a metal wire or a needle-like metal piece.

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