JPH08153472A - Magnetron - Google Patents

Abstract

PURPOSE: To provide a magnetron capable of preventing deformation of a positive electrode vein as well as restraining the uniformity of high frequency field strength in the vicinities of respective positions of the inner surface and the side surface of the positive electrode vein, and capable of restraining the generation of spurious noise and the generation of the undesirable phenomenon of missing pulse as well as obtaining high oscillation efficiency. CONSTITUTION: Two mutually adjacent strap rings 17, 18 out of four or more strap rings 16, 17, 18, 19 whose diameters are different from each other, and arranged in the radial direction at the specified distances are respectively connected to the same first positive electrode vein group 12r. The strap rings 16, 19 arranged inside and outside two strap rings connected to the first positive electrode vein group are connected to a second positive electrode vein group 12p other than the first positive electrode vein grip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron, and more particularly to the structure of its anode vane and strap ring.

[0002]

2. Description of the Related Art In a magnetron for a microwave oven and a pulse magnetron for a part of radar, an even number of anode vanes are radially arranged inside an anode cylinder, and the anode vanes are alternated by a plurality of strap rings. Electrically connected to. This strap ring is indispensable for obtaining stable pi-mode oscillation. For ease of manufacturing, the plurality of strap rings are generally arranged concentrically with different diameters on the side surface side of the anode vane adjacent to the pole piece.

However, since the strap rings for connecting the anode vanes alternately have different diameters and therefore the positions where they are connected to the vanes are different, the high-frequency electric field strength near each position on the inner surface and the side surface of the adjacent anode vanes is not uniform. become. This non-uniformity of the high-frequency electric field strength induces a high-frequency electromagnetic field in the cathode arranged inside the vane or in the pole piece in the vicinity of the side surface of the vane, which causes undesired phenomena such as a decrease in oscillation efficiency and the generation of spurious noise. This is one of the causes. Due to structural or assembly restrictions, such inconvenience is particularly remarkable in the magnetron having the structure in which the strap ring is arranged only on one side surface of the anode vane.

By the way, inventions for solving such inconvenience are disclosed in Japanese Patent Publication No. 62-15815 and Japanese Patent Laid-Open No. 6-20376.
No. 1 or Japanese Patent Publication No. 2-22498. These are all inventions for the purpose of canceling out the non-uniformity of the high-frequency electric field between the two groups of anode vanes to make them uniform, and although their effectiveness is recognized, improvement is still desired in terms of practicality.

[0005]

In other words, the former two are:
Since the strap ring has a complicated structure in which the strap ring intersects at a plurality of points, improvement is desired in terms of assemblability and a lot of space. The latter has a structure in which three strap rings are arranged concentrically, but if one strap ring in the middle is not completely joined to the anode vane even at one place, a stable pie -Mode oscillation operation cannot be obtained and an undesired high frequency induction phenomenon occurs. In the case of a pulse magnetron, a missing pulse phenomenon, that is, an inconvenient phenomenon in which a regular oscillation pulse cannot be obtained, is likely to occur. If all three have the same width in the radial direction, sufficient uniformity of the high-frequency electric field may not be obtained due to irregularities in the direction and amount of thermal expansion of the anode vane and the strap ring. Conceivable. In order to improve it, it is conceivable to widen the radial width of the intermediate strap ring, but in this case, the intermediate strap ring is too strong and the anode vane is apt to be deformed due to thermal strain. As a result, the characteristics of the resonance cavities become uneven, and conversely spurious noise is strongly generated.

On the other hand, there is an invention in which four or more even number of strap rings are connected to the same anode vane in order from the inner strap ring to the outer side.
No. 308847 is disclosed. According to this, it is difficult to completely obtain the uniformization of the high frequency electric field.

According to the present invention, it is possible to suppress the non-uniformity of the high-frequency electric field strength near each position on the inner surface and the side surface of all anode vanes and prevent the anode vanes from being deformed in advance. It is an object of the present invention to provide a magnetron capable of suppressing the occurrence of undesired phenomena such as generation and missing pulses.

[0008]

According to the first aspect of the present invention, two adjacent strap rings out of four or more strap rings having different diameters and arranged at predetermined intervals in the radial direction are the same. The strap rings that are respectively connected to the anode vane group and arranged inside and outside the two strap rings connected to the first anode vane group are connected to the second anode vane group other than the first anode vane group. It is a connected magnetron.

[0009]

According to the present invention, the high-frequency electric field strength is kept uniform near each position on the inner surface and side surfaces of all anode vanes, and the reliability of electrical connection between each anode vane group and the strap ring is enhanced. . In addition, since the width of all strap rings can be reduced, the thermal deformation force on the vanes can be reduced, and deformation of the vanes can be prevented. Therefore, it is possible to obtain high oscillation efficiency and to more reliably suppress the occurrence of spurious noise and the occurrence of undesired phenomena such as missing pulses.

[0010]

An embodiment will be described below with reference to the accompanying drawings.
The same parts are denoted by the same reference numerals. In the embodiment shown in FIGS. 1 to 3, eighteen plate-shaped anode vanes 12 made of copper are radially arranged integrally inside a copper anode cylinder 11, and eighteen resonant cavities 13 are formed by them. Has been done. The output antenna conductor 14 is electrically connected to one anode vane, and this is extended to the output coaxial waveguide 15. An unillustrated cathode for electron emission is arranged in a generally cylindrical space formed by the inner surface 12a at the tip of each anode vane 12. Further, a pair of pole pieces (not shown) are arranged close to the upper and lower side surfaces 12b and 12c of each anode vane 12 so as to close both openings of the anode cylinder 11.

Therefore, the anode vane 12 has one side surface 1
4 copper strap rings 16,1 only on the 2b side
Every other sheet is electrically short-circuited by 7, 18, and 19. These connection positions are represented by black points x. Although these four strap rings are configured to have substantially the same radial width dimension and substantially the same thickness, they have different diameters and are concentrically arranged at substantially equal intervals.

Of the four strap rings, the innermost strap ring 16 and the outermost strap ring 1
9 are connected to a total of nine first anode vane groups 12p every other sheet. The two strap rings 17 and 18 in the middle are the remaining nine second anode vane groups 12r in total.
It is connected to the. These strap rings pass through the cutout grooves 12d and 12e formed on the side surface of the vane in a non-contact manner at a position not connected to the vane.

Further, each strap ring has a cut portion having a width close to the thickness dimension of the anode vane at one position, and the positions of the cut portions are positioned on the anode vane passing through without contact. There is. The cut point 16a of the innermost strap ring and the cut point 19a of the outermost strap ring 19 are on the same anode vane of the first sheet in the counterclockwise direction from the anode vane to which the antenna conductor 14 is connected. It is arranged. Cut point 17a of the strap ring 17 just outside the innermost strap ring
Are the cut points 16a, 19 of the innermost and outermost strap rings.
a is arranged on the anode vane to which the antenna conductor 14 adjacent to the adjacent one in the clockwise direction is connected to the vane.
Furthermore, the cut point 18 of the strap ring 18 on the outside thereof
a is arranged on the second anode vane in the counterclockwise direction from the anode vane to which the antenna conductor 14 is connected.

In this way, of the four strap rings, the two strap rings sandwiched therebetween are connected to the same anode vane group, and the strap rings on the inner and outer sides are connected to the other vane group. There is. As a result, the high frequency electric field strength near the inner surface and the side surface of each anode vane is substantially equalized, and the generation of spurious noise is suppressed. Moreover, since the two strap rings are joined to the same vane at different radial positions, even if there is an incomplete joint with the vane somewhere, the electrical conductivity of every other vane is increased. Since the probability of securing a dynamic short circuit is very high, the pie mode oscillation is stably maintained, and there is almost no possibility of causing inconvenience such as a missing pulse. Furthermore, each strap ring works well even with a relatively thin structure,
There is little influence of mechanical strain on each vane due to thermal expansion and contraction due to on / off of magnetron operation and long-time operation, and there is little risk of vane deformation.

If the cutting positions of the two strap rings in the middle are arranged at different vane positions, the locking of the pie mode oscillation acts more effectively and the stability of the operation is further improved. To do.

In the embodiment shown in FIG. 4, the positions of the respective cut points 16a, 17a, 18a, 19a of the four strap rings are sequentially shifted in the counterclockwise direction from the innermost strap ring to the next vane position by one sheet. It has been arranged. This makes it possible to achieve further stability of operation and further reduction of spurious noise.

In the embodiment shown in FIG. 5, with respect to the positions of the respective cut points of the four strap rings, the cut points 16a and 19a of the innermost and outermost strap rings are moved counterclockwise from the vane to which the antenna conductor 14 is connected. One vane is located next to the vane in the direction, and the other two intermediate cut positions 17a and 18a of the strap rings are further located counterclockwise to the vane next to the vane. It is particularly easy to assemble.

In the above embodiment, four strap rings are used, but one or a plurality of strap rings may be added to the inside or the outside of the strap rings. In that case, it is essential to partially have a configuration in which two adjacent strap rings are connected to the same anode vane group, and the strap rings connected to another anode vane group are arranged inside and outside thereof.

[0019]

As described above, according to the present invention, it is possible to obtain high oscillation efficiency and suppress the generation of spurious noise and the occurrence of undesired phenomena such as missing pulses.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view taken along line 2-2 of FIG.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is a semi-transverse sectional view of essential parts showing another embodiment of the present invention.

FIG. 5 is a semi-transverse sectional view of an essential part showing still another embodiment of the present invention.

[Explanation of symbols]

11 ... Anode cylinder 12, 12p, 12r ... Anode vane 12p ... 1st anode vane group 12r ... 2nd anode vane group 16, 17, 18, 19 ... Strap ring 16a, 17a, 18a, 19a ... Cutting of strap ring Department

Claims (3)

[Claims] 1. An anode cylinder, an even number of anode vanes radially arranged inside the anode cylinder, and every other anode vane connected to one side surface of the anode vane and having different diameters. In a magnetron comprising four or more strap rings arranged at a predetermined interval in a radial direction, two adjacent strap rings of the plurality of strap rings have the same first anode. The strap rings arranged inside and outside of the two strap rings connected to the vane group and connected to the first anode vane group are arranged in the second anode vane group other than the first anode vane group. Magnetron characterized by being connected. 2. The two strap rings connected to the first anode vane group are cut at the positions of the anode vanes to which these strap rings are not connected, and the two cut portions of the two strap rings are cut. The magnetron according to claim 1, wherein the positions are different from each other. 3. The strap rings arranged inside and outside the two strap rings are cut at the position of the anode vane to which these strap rings are not connected, and the cut portions of each of the two strap rings are cut. The magnetron according to claim 1 or 2, wherein the positions are different from each other.