JPS63221536A - Radio wave leak preventing device for magnetron - Google Patents

Abstract

PURPOSE:To sharply improve the removing force of a cover and concurrently reduce the leak of the higher harmonic wave by providing a flange section at the peripheral section of the filter case of a magnetron, closely coupling it with a case cover, and bringing the end face of the flange section into contact with the case cover with a caulking tooth profile. CONSTITUTION:A flange section 15a is formed at the opening peripheral section of a filter 15. A flange 16a with a cavity section to insert the flange 15a is provided at the peripheral section of a cover 16, and the flange 15a is coupled with it by pressure. Then, a V-shaped caulking tooth profile is formed with a caulking jig on the contact face between the flange sections 15a, 16a so that the end face of the flange 15a is brought into contact with the inner face of the flange 16a with the pitch of the lambda/4 wavelength of the (n)th higher harmonic wave. According to this constitution, the removing force of the cover 16 is improved, and the leak of the (n)th higher harmonic wave is reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetron radio wave leakage prevention device, and in particular to a noise canceling filter circuit that suppresses the leakage of specific strong noise radio waves such as harmonics generated from a magnetron. This concerns the structure of the filter case that stores the .

[Conventional technology]

Normally, when a magnetron oscillates, harmonics including the magnetron's oscillation fundamental wave, as well as VHF and UHF band waves, propagate through its cathode circuit and are radiated to the outside as unnecessary radio waves. For this reason, the magnetron is required to be equipped with a noise-cancelling filter circuit that attenuates and eliminates the noise radio waves from the cathode circuit and eliminates the influence on television, radio, wireless communications, etc.

An example of such a filter circuit is Japanese Patent Application Laid-Open No. 55-4984.
This is disclosed in Publication No. 4, etc.

Such a filter circuit generally consists of a combination of a coil and a capacitor.A filter case is provided at the input terminal of the magnetron's cathode circuit, and the filter circuit is housed within the filter case. The structure of the installation will be explained in detail based on the drawings.

FIGS. 7 and 8 are a partially cutaway plan view and a sectional view of the main parts of the structure of a conventional magnetron radio wave leakage prevention device, and other parts are omitted. In these figures, 1 is a magnetron main body that has a known internal structure and outputs high-frequency energy, and this magnetron/main body 1 has a disk-shaped magnetic shunt on the high-frequency output section 2 and cathode input section 3 side. Annular permanent magnets 6 and 7 are disposed through plates 4 and 5, respectively, and are held and fixed by screws 10 between an upper yoke 8 and a lower yoke 9 made of magnetic material forming a magnetic circuit. ing. Further, on the outer circumference of the magnetron main body 1, a radiator fin 11 surrounding the circumferential side is provided.
are arranged in a mating manner.

Further, a filter case 15 and a lid 16 are attached and fixed to the anode input section 3 of the magnetron main body 1 to house a filter circuit 14 consisting of a coil 12 and a capacitor 13 that attenuate and eliminate noise radio waves leaking to the outside. 14, the coil 12 thereof is connected to a pair of cathode terminals 18 provided at the tip of the stem 17 of the cathode input section 3, and the capacitor 13 penetrates the filter case 15 with the other end protruding to the outside, and is connected to an external AC power source. An input terminal 19 to be connected to is integrally provided.

[Problem that the invention seeks to solve]

However, in the magnetron radio wave leakage prevention device configured as described above, after the filter circuit 14 is housed in the filter case 15, the opening periphery of the filter case 15 and the lid 16 are combined to prevent a gap from forming. It is tightly fitted by caulking.

However, the filter case 15 is filled with the magnetron's fundamental oscillation frequency of 2450 MHz and its harmonic components 9, and the radio waves from this woodcutter leak through a small gap.

Therefore, it is necessary to ensure electrical contact at a pitch of 1/4 wavelength of the unnecessary radiated radio waves to be suppressed. In addition, if the lid 16 comes off, 2450, which has a large amount of energy,
Since the leakage of the fundamental wave of 1 Hz noise may occur and cause harm to the human body, it is necessary to provide sufficient reliability with respect to the force with which the lid 16 is removed.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and its purpose is to improve the electrical contact between the filter case and its lid and the removal force function, and to improve the reliability of the magnetron's radio wave leakage. The object of the present invention is to provide a prevention device.

[Means for solving problems]

The magnetron radio wave leakage prevention device according to the present invention includes a flange portion provided at the periphery of the opening of the filter case.
The lower part of the second flange part is tightly fitted with the case lid, and the end face of the flange part and the case lid are brought into contact with each other in a caulked tooth shape having a pitch of 4 of the n-th harmonic.

[Effect]

In the present invention, the flange portion locks the removal force of the case lid, and the contact of the caulked teeth suppresses leakage of n-th harmonics.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a main part showing an embodiment of the electromagnetic wave leakage prevention device for a magnetron according to the present invention, and the same parts as those in the above-mentioned figures are given the same reference numerals, and the explanation thereof will be omitted. In the figure, a flange part 15a is formed around the entire circumference of the opening of the filter case 15, as shown in the enlarged cross-sectional view in FIG. 2, with its tip bent outward. on the other hand,
On the other hand, the peripheral edge of the lid 16 has the seventh rank portion 15a.
A 7-rank portion 16a is formed having a cavity into which the 7-rank portion 16a is inserted. After storing the filter circuit 14 in the filter case 15, the 7 rank section 1 of the filter case 15 is
5m and the 7-rank portion 16a of the lid 16 and are fitted together by applying mechanical pressure from the tube axis direction.

Subsequently, as shown in FIG. 3, a receiver jig 30t is placed in the peripheral groove 16b of the lid 16, and caulking blades are arranged at a pitch of λ/4 (wavelength) of the n-th harmonic as shown in FIG. 31
The crimping jig 31 having & is attached to the flange portion 16a of the lid 16.
By applying mechanical pressure to the outer peripheral surface in the direction of the arrow and caulking, a V-shaped caulking is formed on the contact surface between the flange portion 15a of the filter case 15 and the flange portion 16a of the case lid 1G, as shown in FIG. A tooth profile 20 is formed between the end face of the flange portion 15a of the filter case 15 and the 7 of the case lid 16.
The inner surface of the rank part 16a is brought into contact with the inner surface of the rank part 16a at a pitch of λ/4 wavelength of the n-th harmonic across their peripheral edges, and the flange part 16a of the case lid 16 is caulked to the lower side of the flange part 15a of the filter case 15 for a tight fit. be done.

According to such a configuration, the 7-rank portion 15a is provided at the opening peripheral edge of the filter case 15 and closely fitted with the flange portion 16m of the case lid 16, so that the flange portion 15a of the filter case 15 is connected to the case lid 16. Since the removal acts as a stopper in the direction, the removal force of the case lid 16 can be greatly improved. In addition, by forming a crimp tooth shape 20 with a pitch of 94 wavelengths of the n-th harmonic on the contact surface between the 7279 part 15m of the filter case 15 and the 7 rank part 16 of the case lid 16, the filter case 15 and the case are brought into contact. If electrical contact with the lid 16 is reliable and complete, leakage of n-th harmonics can be significantly reduced.

In the above-mentioned embodiment, the case where the 7-rank part 15a of the filter case 15 was formed with its tip facing outward was explained, but the same effect can be obtained even if it is formed with the tip facing inward as shown in FIG. Of course, the effect can be obtained.

Further, in the embodiment described above, the flange portion 1 of the lid 16
A caulking tooth profile 20 formed by a caulking blade 31a is formed on the outer peripheral surface of 6a.
Although a case has been described in which a similar caulked tooth profile 20 is formed on the inner circumferential surface of Vζ at the same time, electrical contact can be further improved.

〔Effect of the invention〕

As explained above, according to the present invention, a flange is provided at the periphery of the opening of the filter case, and the flange is closely fitted with the case lid on the lower side of the flange, and the end face of the flange and the case lid are connected to the n-th order. By making contact with a caulked tooth shape with a pitch of X/4 wavelength of harmonics, the extraction force is significantly reduced and leakage of n-th harmonics is suppressed, resulting in high quality and reliable magnetron radio wave leakage prevention. An extremely excellent effect can be obtained in that the device is obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the magnetron radio wave leakage prevention device according to the present invention, and FIGS. 2 and 3 are main points showing the fitting relationship between the 72-inch portion of the filter case and the flange portion of the case lid. The fourth factor is a perspective view showing the caulking jig, FIG. 5 is an enlarged sectional view of the main part showing the electrical contact relationship between the flange of the filter case and the rank 7 part of the case lid, and FIG. 6 FIG. 7 is an enlarged sectional view of a main part showing another embodiment of the electromagnetic wave leakage prevention device for a magnetron according to the present invention. FIG. 8 is a partially cutaway plan view showing the structure of a conventional radio wave leakage prevention device for a magnetron, and a sectional view of the main part thereof. 3... Cathode input section, 12... Coil, 13...
...Capacitor, 14...Filter circuit, 15-...
・Fist filter case, 15a ... flange part, 1
6...Case lid, 16a...Original 7279 copies, 16
b ... Peripheral groove, 20, conflict, working tooth profile, 30
Conflict/e11 receiving jig, 31...ψ/caulking jig, 31a
...Caulking blade.

Claims (1)

[Claims] 1. In a magnetron radio wave leakage prevention device in which a filter circuit consisting of a coil and a capacitor is housed in a filter case that is attached and fixed to the cathode input section of the magnetron main body, and is fitted with a case lid, the opening of the filter case A flange portion is provided at the periphery, and the lower side of the flange portion is tightly fitted with the case lid, and the end face of the flange portion and the case lid are formed into a caulked tooth shape having a pitch of λ/4 (wavelength) of the n-th harmonic. A magnetron radio wave leakage prevention device characterized in that the magnetron is brought into contact with the