JP2006040576A - Magnetron - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetron capable of suppressing magnetic loss by tightly fitting a permanent magnet to a yoke and of preventing dispersion and degradation of a positive electrode voltage value in rated oscillation. <P>SOLUTION: This magnetron 100 is so structured that tapes 18 having electrical insulation capability and heat insulation capability for bundling windings for forming electromagnetic coils 13a and 13b are interlaid between the electromagnetic coils 13a and 13b and the yokes 11a and 11b made of a ferromagnetic material; and a silicon material 20 having electrical insulation capability and heat resistance is put in a space between the electromagnetic coil 13a and the permanent magnet 12a generated by the thickness of the tape 18 to joint both of them to each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a magnetron used for a high-frequency heating device or the like in a microwave oven or an industrial field.

Conventionally, a magnetron having a magnetic circuit section for enabling stable microwave oscillation has been proposed (see, for example, Patent Document 1).
FIG. 5 is a longitudinal sectional view showing the inside of the anode cylinder including the magnetic circuit part of the magnetron disclosed in this publication. FIG. 6 is a perspective view showing the appearance of the magnetic circuit portion of the magnetron shown in FIG.

  In FIG. 5, a magnetron 1 having a magnetic circuit section includes a cylindrical anode cylinder 2, a magnetic pole piece 3 attached to the lower opening end of the anode cylinder 2, and a metal disposed on the magnetic pole piece 3. A cylindrical body 4, a magnetic pole piece 5 attached to the upper opening end of the anode cylindrical body 2, a metal cylindrical body 6 disposed on the magnetic pole piece 5, and a radial shape around its central axis in the anode cylindrical body 2. And a plurality of anode vanes 7 fixed to the inner peripheral surface of the anode cylinder 2, and a microwave emission antenna 8 electrically connected to a specific one of the plurality of anode vanes 7, A cathode 9 disposed on the central axis of the anode cylinder 2; a magnetic circuit section 10a provided below the anode cylinder 2; and a magnetic circuit section 10b provided above the anode cylinder 2. Yes.

The magnetic circuit unit 10a includes a yoke 11a made of a ferromagnetic material, a ring-shaped permanent magnet 12a provided on the pole piece 3 side of the yoke 11a, and the permanent magnet 12a coaxially with the outer peripheral side of the permanent magnet 12a. It is comprised from the arrange | positioned ring-shaped electromagnetic coil 13a.
Similarly to the magnetic circuit unit 10a, the magnetic circuit unit 10b includes a yoke 11b made of a ferromagnetic material, a ring-shaped permanent magnet 12b provided on the pole piece 5 side of the yoke 11b, and the permanent magnet 12b. The ring-shaped electromagnetic coil 13b is arranged coaxially with the permanent magnet 12b on the outer peripheral side.

  The magnetron 1 energizes the electromagnetic coils 13a and 13b during oscillation, finely adjusts the magnetic flux density, and controls the anode voltage value.

  In such a magnetron 1, the electromagnetic coil 13a is fixed to the yoke 11a as follows. That is, as shown in FIG. 6, the electromagnetic coil 13 a is wound with yarns 15 and 16 having electrical insulation and heat insulation in several places together with the winding (not shown) alone or with the permanent magnet 12 a. Magnetically connected to the yoke 11a made of a ferromagnetic material. Therefore, a gap 17 corresponding to the thickness of the threads 15 and 16 is formed at least between the electromagnetic coil 13a and the yoke 11a, and both are connected.

By forming such a gap 17, overheating can be suppressed and electrical insulation can be increased between the electromagnetic coil 13 a and the yoke 11 a or between the electromagnetic coil 13 a and the permanent magnet 12 a. It was.
The same relationship exists between the other permanent magnet 12b, the electromagnetic coil 13b, and the yoke 11b.

JP-A-5-67435

  However, in the conventional magnetron, for example, the magnetic circuit portion 10a provided below the anode cylinder 2 will be described. The yarn 15 for bundling the windings of the electromagnetic coil 13a, the electromagnetic coil 13a and the permanent magnet 12a As described above, the yarn 16 for integrating the yarns is interposed between the yoke 11a and the electromagnetic coil 13a and between the yoke 11a and the permanent magnet 12a. A gap corresponding to the thickness of. At that time, the gap between the electromagnetic coil 13a and the yoke 11a and between the electromagnetic coil 13a and the permanent magnet 12a is an important structure for ensuring electrical insulation. The gap between them causes a large magnetic loss in forming the magnetic circuit, and causes variations and decreases in the anode voltage value at the rated magnetron oscillation.

  Here, in the magnetron that requires delicate control of the anode voltage value, the variation in the initial anode voltage value in a state where the electromagnetic coil is not energized is an electromagnetic coil for controlling the magnetic flux density generated in the electromagnetic coil. Variation of the current flowing through the. That is, in order to cover the variation of the magnetron, it is necessary to individually adjust the electromagnetic coil control power supply side. This adjustment takes a lot of time, and it is difficult to adjust to the same anode voltage value unless one with specialized knowledge. Therefore, variations in the initial anode voltage value when the electromagnetic coil is not energized are minimized. It is necessary to keep it down.

  The present invention has been made in view of the above circumstances, and an object thereof is to form an electrical insulation between the electromagnetic coil and the yoke without forming a gap between the permanent magnet and the ferromagnetic yoke. It is to provide a magnetron that can secure the property.

The above object is achieved by the following configuration.
(1) A ring-shaped electromagnetic coil is coaxially disposed on the outer peripheral side of a ring-shaped permanent magnet disposed on the pole piece, and the permanent magnet and the electromagnetic coil are magnetically connected to a ferromagnetic yoke. In a magnetron with a structure
A bundling member having electrical insulation and heat insulation properties for bundling the windings forming the electromagnetic coil is interposed between the electromagnetic coil and the yoke and between the electromagnetic coil and the permanent magnet, and The yoke is in close contact with the permanent magnet.

(2) In the magnetron according to the above (1), a gap between the electromagnetic coil and the permanent magnet generated by the thickness of the binding member is filled with an adhesive having electrical insulation and heat resistance. May be a feature.

(3) In the magnetron according to the above (1) or (2), a ring-shaped sheet member having electrical insulation and heat insulation may be interposed between the electromagnetic coil and the yoke. Good.

(4) A high-frequency heating device includes the magnetron described in any one of (1) to (3) above.

  According to the magnetron described in the above (1), since the electromagnetic coil is connected to the ferromagnetic yoke with the binding member interposed therebetween, electrical insulation can be secured between the electromagnetic coil and the yoke. Moreover, since the yoke is in close contact with the permanent magnet, a stable magnetic circuit can be formed. As a result, the magnetic loss can be suppressed compared to the conventional structure in which a gap is formed between the permanent magnet and the yoke by the thickness of the bundling member, and the variation and decrease in the anode voltage value during magnetron rated oscillation are minimized. Is possible.

  According to the magnetron described in (2) above, since the binding member and the adhesive material having electrical insulation and heat resistance are interposed between the electromagnetic coil and the permanent magnet, the electrical insulation between the two is ensured. Can be secured.

  According to the magnetron described in (3) above, the electrical insulation between the electromagnetic coil and the yoke is achieved by interposing an electrically insulating and heat insulating ring-shaped sheet member between the electromagnetic coil and the yoke. Can be further ensured.

  According to the high-frequency heating device described in (4) above, variation and decrease in the anode voltage value at the time of magnetron rated oscillation can be minimized, so that stable oscillation is possible, so performance and reliability are high. A high-frequency heating device can be provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing the inside of an anode cylinder including a magnetic circuit part of a magnetron according to an embodiment of the present invention. FIG. 2 is a perspective view showing the appearance of the magnetic circuit portion of the magnetron shown in FIG. 1 and 2 that are the same as those in FIGS. 5 and 6 described above are denoted by the same reference numerals. Also, description of common parts is omitted.

As shown in FIG. 1, the magnetron 100 according to the present embodiment uses the tape 18 while bundling the windings of the electromagnetic coils 13 a and 13 b with a tape 18 having electrical insulation and heat insulation properties. As shown in FIG. 2, a gap 17 between the electromagnetic coils 13a and 13b and the permanent magnets 12a and 12b generated by the thickness is filled with a silicon material 20 having electrical insulation and heat resistance, so that the both are obtained. Each is joined.
Further, as shown in FIG. 3, a ring-shaped sheet member 22 having good electrical insulation and heat resistance is interposed between the electromagnetic coils 13a and 13b and the yokes 11a and 11b. Heat resistant rubber can be used as the sheet member 22.

  Similarly, the ring-shaped electromagnetic coil 13a is disposed coaxially with the permanent magnet 12a on the outer peripheral side of the ring-shaped permanent magnet 12a, and the ring-shaped electromagnetic coil 13b is also formed on the outer peripheral side of the ring-shaped permanent magnet 12b. It is arranged coaxially with 12b.

  FIG. 3 is a cross-sectional view showing the difference in structure between the magnetron 100 of the present embodiment and the conventional magnetron 1 shown in FIG. The right side is the magnetron 100 of this Embodiment and the left side is the conventional magnetron 1 toward the figure. Although only the lower magnetic pole piece 3 side is shown in this figure, the same applies to the upper magnetic pole piece 5 side.

  In the magnetron 100 of the present embodiment, the tape 18 is used only for bundling the windings of the electromagnetic coil 13a and is not used for integrating the electromagnetic coil 13a and the permanent magnet 12a. Therefore, the tape 18 is not interposed between the permanent magnet 12a and the yoke 11a, and the yoke 11a is in close contact with the permanent magnet 12a. Therefore, the electromagnetic coil 13a and the permanent magnet 12a are joined by the silicon material 20 having electrical insulation and heat resistance as described above.

On the other hand, in the conventional magnetron 1, the yarn 16 is used to bundle the electromagnetic coil 13a and the permanent magnet 12a, and the yarn 16 is interposed between the permanent magnet 12a and the yoke 11a. The thickness of the yarn 16 becomes a gap and causes magnetic loss. The magnetic loss causes variations and decreases in the anode voltage value during magnetron rated oscillation.
On the other hand, in the magnetron 100 of the present embodiment, as will be described again, there is no tape 18 between the permanent magnet 12a and the yoke 11a, and the permanent magnet 12a is in close contact with the yoke 11a. .

The difference between the magnetron 100 of the present embodiment and the conventional magnetron 1 will be described with a specific example.
FIG. 4 is a graph showing an experimental result of the anode voltage at the rated oscillation with the same magnetization voltage (630 V). The magnetron 100 of the present embodiment is the same as the conventional magnetron 1 except for the structure of the magnetic circuit section, and the anode voltage value at the rated oscillation of both the magnetron 100 of the present embodiment and the conventional magnetron 1 is the standard center. It is a 4.0 kV magnetron.

The graph shown in FIG. 4 shows the magnetron (not shown) having only the permanent magnets 12a and 12b without the electromagnetic coils 13a and 13b shown for comparison, the conventional magnetron 1 shown in FIG. 5, and FIG. Each of the 20 magnetrons 100 according to the present embodiment was magnetized at 630 V when the magnetron was assembled, the anode voltage at the rated oscillation was measured, and the magnetic loss was evaluated based on the distribution and reduction rate of the anode voltage value. is there.
As shown in this figure, when comparing the anode voltage values of a magnetron not having an electromagnetic coil and other magnetrons, the distribution of the conventional magnetron 1 is large, and the average of 20 units decreases by 1.2%. It was seen. On the other hand, the magnetron 100 of the present embodiment shows almost no difference from the magnetron having no electromagnetic coil regardless of the distribution and the decrease rate, and it can be seen that the magnetic loss is suppressed.

Thus, according to the magnetron 100 of the present embodiment, the tape 18 that is a binding member is interposed between the electromagnetic coils 13a and 13b and the yokes 11a and 11b, and the electromagnetic coil generated by the thickness of the tape 18 is produced. Since the gap between the magnets 13a and 13b and the permanent magnets 12a and 12b is filled with the silicon material 20 having electrical insulation and heat resistance, the gap between the electromagnetic coils 13a and 13b and the yokes 11a and 11b is adopted. It is possible to reliably ensure electrical insulation.
Further, since the tape 18 is not interposed between the permanent magnets 12a and 12b and the yokes 11a and 11b, both are in close contact with each other to form a stable magnetic circuit. As a result, the magnetic loss is suppressed as compared with the conventional magnetron 1 in which a gap is formed between the permanent magnet and the yoke by the thickness of the thread 16, and the variation and decrease in the anode voltage value at the time of magnetron rated oscillation are minimized. Can be suppressed.

Furthermore, in the above embodiment, since the sheet member 22 having good electrical insulation and heat resistance is inserted between the electromagnetic coils 13a and 13b and the yokes 11a and 11b, the electromagnetic coils 13a and 13b and the yoke 11a. , 11b can be ensured more reliably.
However, the sheet member 22 is omitted, and the electrical insulation between the electromagnetic coils 13a and 13b and the yokes 11a and 11b is provided by a gap corresponding to the thickness of the tape 18 wound around the electromagnetic coils 13a and 13b. You may make it secure.

  Further, in the present embodiment, the tape 18 is used to bundle the windings for forming the electromagnetic coils 13a and 13b. However, a conventionally used yarn may be used.

  Moreover, in the said embodiment, although the permanent magnet 12a (12b) was made into the 1 step | paragraph structure, when using several permanent magnets, such as the high output magnetron used in the industrial field | area etc. Can adopt the same structure, and the same effect can be obtained.

  In addition, when the magnetron 100 of the present embodiment is used for a high-frequency heating device, variation and decrease in the anode voltage value during magnetron rated oscillation can be minimized, so that stable oscillation is possible, and performance and reliability are improved. A high-frequency heating device can be provided.

  It can be applied to all applications using a magnetron such as a microwave oven.

It is a longitudinal cross-sectional view which shows the inside of an anode cylinder containing the magnetic circuit part of the magnetron concerning one embodiment of this invention. It is a perspective view which shows the external appearance of the magnetic circuit part of the magnetron which concerns on one embodiment. It is a longitudinal cross-sectional view for demonstrating the difference between the magnetron which concerns on one Embodiment, and the conventional magnetron. It is a graph which shows the anode voltage comparison result at the time of rated oscillation in the same magnetizing voltage in the magnetron which concerns on one Embodiment, the magnetron which has the conventional electromagnetic coil, and the magnetron which does not have the conventional electromagnetic coil. It is a longitudinal cross-sectional view which shows the inside of an anode cylinder containing the magnetic circuit part of the conventional magnetron. It is a perspective view which shows the general appearance of the magnetic circuit part of the conventional magnetron.

Explanation of symbols

2 Anode cylinder 3, 5 Pole piece 7 Anode vane 30 a, 30 b Magnetic circuit section 11 a, 11 b Yoke 12 a, 12 b Permanent magnet 13 a, 13 b Electromagnetic coil 18 Tape 20 Silicon material 22 Sheet member 100 Magnetron

Claims (4)

A structure in which a ring-shaped electromagnetic coil is coaxially disposed on the outer peripheral side of a ring-shaped permanent magnet disposed on the pole piece, and the permanent magnet and the electromagnetic coil are magnetically connected to a ferromagnetic yoke. In the magnetron
A bundling member having electrical insulation and heat insulation properties for bundling the windings forming the electromagnetic coil is interposed between the electromagnetic coil and the yoke and between the electromagnetic coil and the permanent magnet, and A magnetron characterized in that a yoke is in close contact with the permanent magnet.   The magnetron according to claim 1, wherein a gap between the electromagnetic coil and the permanent magnet generated by the thickness of the binding member is filled with an adhesive having electrical insulation and heat resistance.   The magnetron according to claim 1 or 2, wherein a ring-shaped sheet member having electrical insulation and heat insulation is interposed between the electromagnetic coil and the yoke.   A high-frequency heating apparatus comprising the magnetron according to claim 1.

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