JP2913194B2 - Magnetron filament support structure - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron, and more particularly to a magnetron filament support structure with improved seismic strength to avoid disconnection of the filament due to external impact.

[Conventional technology]

Generally, a filament of a magnetron is supported by a pair of support leads, and there is a problem in that if a shock is applied from the outside and the support leads are brought into a resonance state, the supported filaments are disconnected.

As a countermeasure to such a problem, a configuration provided with a structure as shown in FIG. 3 is known.

3 (a), 3 (b), and 3 (c) are explanatory views of a conventional filament support structure provided with an earthquake-resistant mechanism. Is an end shield, 8a and 8b are external leads,
9a and 9b are vibration-proof materials, 10a and 10b are the inner ends of the external leads 8a and 8b, and 11a and 11b are connected bodies.

FIG. 7A shows a structure in which the support leads 1a and 1b are provided with an anti-vibration material 9a connected to an insulating ceramic stem to suppress resonance vibration, thereby avoiding disconnection of the filament 6. FIG. 3B shows a structure in which a vibration isolator 9b is installed on one end shield 7b to mechanically suppress the vibration of the filament 6. The above-mentioned vibration isolator uses the same ceramic as the insulating ceramic stem 3.

FIG. 3C shows the supporting leads 1a and 1b and the external lead 8a (8
b) is a separate component, and the connecting leads (conductors) fixed to the insulating ceramic stem 3 mechanically hold down the support leads 1a and 1b to obtain an anti-vibration effect.

The above prior art is disclosed in JP-A-63-86220, JP-A-63-86221, and JP-A-62-55848.

[Problems to be solved by the invention]

In the above-mentioned conventional technology, the problem that the filament is disconnected when vibration is applied from the outside and the support lead causes resonance is a concept of firmly fixing the support lead.

However, simply fixing the support portion of the support lead firmly to the stem can reduce the amplitude at resonance, but increases the resonance frequency and conversely reduces the acceleration applied to the filament. It cannot be reduced. The arrangement of the connecting member between the two support leads has the disadvantage that the number of components of the magnetron increases and the assembly process becomes complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetron filament support structure that does not require an earthquake-resistant component against external vibrations and has improved strength against filament disconnection.

[Means for solving the problem]

The above-mentioned object is to set the cross-sectional area of the support hole for supporting the positioning of the support lead formed in the insulating ceramic stem to be approximately 1.5 times or more the cross-sectional area of the supporting lead, and to interpose the insulating lead between the insulating ceramic stem and the supporting lead. This is attained by forming the sealing plate for fixing the both members in such a thickness as to reduce the vibration frequency of the support lead.

[Action]

If there is a possibility that the filament support structure will be in resonance with external vibration and the filament will be disconnected, it is important to adopt a structure that minimizes the amplitude during resonance. Generally, if the amplitude magnification at resonance is μ, It is known that the amplitude magnification μ is related only to the attenuation ratio.

According to the present invention, the insulating ceramic stem is formed as a stepped hole in which the bottom area of the supporting hole of the supporting lead formed in the insulating ceramic stem is large enough to fit the supporting lead, and the opening area is larger than the cross-sectional area of the lead. By adopting a structure in which the support lead is fixedly supported via a sealing plate interposed between the support leads, the vibration of the support lead is increased by the deflection of the sealing plate, and the elastic damping rate is increased. Can increase the frictional damping ratio with the insertion portion of the wire, and can prevent the filament from being disconnected.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view for explaining one embodiment of a magnetron filament support structure according to the present invention, wherein 1a and 1b are support leads, 2a and 2b are sealing plates, 3 is an insulating ceramic stem, and 4 is a support hole. , 6 are filaments, 7a and 7b are end shields, and 8a and 8b are external leads.

In the figure, a spirally wound filament 6 has both ends fixed to end shields 7a and 7b. Each of the end shields 7a and 7b is further disposed on the insulating ceramic stem 3 via the sealing plates 2a and 2b by the support leads 1a and 1b.

The filament support structure thus configured is incorporated into the magnetron body structure, and the filament 6 is heated by the current supplied from the support leads 1a and 1b to emit thermoelectrons.

FIG. 2 is a sectional view of a member for explaining the configuration of the main part of FIG. 1. Reference numeral 5 denotes a silver-row layer, 5a denotes a pool for silver-row, 11 denotes a burring hole, and the same reference numerals as those in FIG. Corresponding to the part.

In the drawing, support leads 1a and 1b made of a high melting point material are formed of a conductive material having a diameter of, for example, 1.5 mm, and a sealing plate 2a made of an iron-nickel (Fe-Ni) material having a plate thickness of, for example, 0.2 mm. 2b
Is inserted into the support hole 4 of the support lead of the insulating ceramic stem 3 through the burring hole 11 formed therein, and the fitting portion to the burring hole 11 is sealed with a sealing plate 2a by silver brazing (not shown). Fixed to 2b. The supporting hole 4 of the supporting lead of the insulating ceramic stem 3 is formed such that the diameter around the bottom is, for example, 1.6 mm and the diameter around the opening is, for example, 2.2 mm, and the opening has a step having a larger diameter than the bottom. It has a shape. A Mo-Mn metallized layer for soldering silver to the sealing plates 2a and 2b is provided on a flat peripheral surface around the opening of the support hole 4.

In the present embodiment, the support hole 4 provided in the insulating ceramic stem 3 is a vertical hole, and its bottom cross-sectional area is capable of inserting the support leads 1a and 1b and is substantially equal to the cross-sectional area of the support leads 1a and 1b. On the other hand, the opening cross-sectional area is at least about 1.5 times the cross-sectional area of the support leads 1a, 1b.
It has a stepped shape that is doubled.

In this case, the reason why the opening cross-sectional area of the support hole 4 is set to be approximately 1.5 times or more the bottom cross-sectional area is that when the opening cross-sectional area is approximately 1.5 times or less the bottom cross-sectional area, The resonance frequency is increased, and the high resonance frequency prevents the filament 6 from being broken. Also, when the sealing plates 2a, 2b are attached to the upper surface of the insulating ceramic stem 3 by silver solder, the support lead 1a is overflowed by the silver solder. , 1b and the insulating ceramic stem 3 are prevented from being soldered to silver.

The reason why the sealing plates 2a and 2b having a thickness of approximately 0.1 to 0.25 mm are used for the supporting leads 1a and 1b having a diameter of 1.5 mm is that the sealing plate 2a having a thickness of approximately 0.1 mm or less. In order to prevent the amplitude of the swing of the support leads 1a and 1b from being too large when using the sealing leads 2a and 2b, when using the sealing plates 2a and 2b having a thickness of about 0.25 mm or more, The bending of the sealing plates 2a, 2b is reduced, and the resonance frequency of the support leads 1a, 1b is reduced.
This is to prevent the water from being absorbed sufficiently.

The sealing plate 2 to which the support leads 1a and 1b are fixed is brazed to the insulating ceramic stem 3 with the support leads 1a and 1b inserted into the support holes 4 of the insulating ceramic stem 3.
The sealing plates 2a and 2b are previously coated with a brazing material for brazing silver between the support leads 1a and 1b and the insulating ceramic stem 3 by plating or the like. Thus, the brazing of the support lead 1 and the sealing plates 2a and 2b is assured, and the solder pool 5a formed around the end of the silver brazing layer 5, that is, around the opening of the supporting hole 4 of the insulating ceramic stem 3 can be reduced. it can.

With this configuration, the support leads 1a and 1b are fixed to the insulating ceramic stem 3 via the sealing plates 2a and 2b, so that the displacement of the support leads 1a and 1b due to external vibration causes the sealing plates to move. It is deformed and attenuated by the elastic damping rate of the sealing plates 2a and 2b and the friction between the bottom peripheral wall of the support hole 4 and the peripheral surface on the end side of the support lead, and the amplitude is suppressed without increasing the resonance frequency of the support lead. You.

〔The invention's effect〕

As described above, according to the present invention, it is possible to prevent disconnection due to the vibration of the filament without requiring any parts for countermeasures against seismic vibration, and a filament supporting structure of a magnetron having excellent functions except for the disadvantages of the prior art. Can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an embodiment of a magnetron filament support structure according to the present invention, FIG. 2 is a partial cross-sectional view illustrating main components of FIG. 1, and FIG. 3 is a conventional magnetron filament. It is explanatory drawing of a support structure. 1a, 1b: support lead, 2a, 2b: sealing plate, 3: insulating ceramic stem, 4: support hole, 5: silver low layer, 5a ...
… Silver low pool, 6… Filament, 7a, 7b ……
End shield, 8a, 8b …… External lead.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-55848 (JP, A) JP-A-2-8847 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01J 23 / 04,23 / 05

Claims (3)

(57) [Claims] 1. Two supporting leads for supporting both ends of a helical filament via end shields, respectively.
An insulating ceramic stem having a supporting hole for supporting and positioning the supporting lead, and a sealing plate interposed between the supporting lead and the insulating ceramic stem, wherein the supporting lead is provided in the supporting hole. In a magnetron filament supporting structure in which the supporting lead and the insulating ceramic stem are fixed via a sealing plate in a state of being positioned and supported, the supporting hole provided in the insulating ceramic stem forms a vertical hole, and The bottom cross-sectional area of the hole is large enough to fit and support the support lead, and the opening cross-sectional area of the support hole is a stepped shape having a size of about 1.5 times or more the cross-sectional area of the support lead. Magnetron filament support structure. 2. The magnetron filament according to claim 1, wherein said sealing plate is made of an iron-nickel material having a thickness of about 0.1 to 0.25 mm when said support lead has a diameter of about 1.5 mm. Support structure. 3. The magnetron filament support structure according to claim 1, wherein a plating layer is provided on at least a surface of the sealing plate facing the insulating ceramic stem.