JPH02242551A - Anode structure for magnetron - Google Patents

Abstract

PURPOSE:To facilitate the design of a small-sized magnetron by disposing a pair of metallic rings on the inner circumferential side of an anode cylinder. CONSTITUTION:Plural anode vanes 2 projecting from the inner circumferential surface to the central axis of an anode cylinder 1 are short-circuited at every other position with two pairs of potential equalizing rings 3, 4 disposed on the axial end surface 2 of the cylinder. A pair of metallic rings 6a, 6b for resonance frequency modulation projecting in two stages from the inner circumferential surface toward the central axis side of the anode cylinder 1 are electrically connected to end surfaces of all of the anode vane 2. As a result, the electrostatic capacity along the inner circumferential surface of the anode cylinder 1 is increased with the paired metallic rings 6a, 6b with the amount of increase dependent on the widths and mutual distance of the paired metallic rings installed. As the electrostatic capacity of the resonance cavity is increased with the paired metallic rings, resonance frequency f shirts to a lower side and the setting of the resonance frequency is made easier when designing a small-sized device.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an anode structure of a magnetron used in microwave heating devices such as microwave ovens and medical equipment.

2. Description of the Related Art Generally, the microwave oscillation frequency of a magnetron is determined by the resonance frequency, and the resonance frequency is determined by the dimensions of the anode cylinder, the anode vane, the pressure equalizing ring, and the like. Therefore, in the inspection process of the assembled anode assembly, the pressure equalizing ring attached to the anode vane is deformed and adjusted to obtain a predetermined resonance frequency. However, as magnetrons become more compact, the diameter of the equalizing ring is also becoming smaller, making it difficult to provide the necessary deformation to the equalizing ring, and if a thin equalizing ring is used, undesirable deformation will occur at high temperatures.

In the device disclosed in Japanese Utility Model Application Publication No. 58-62538, as shown in FIGS. 3 and 4, a large number of anode vanes 2 protruding from the inner circumferential surface of the anode cylinder 1 toward the central axis are In addition, a metal ring 5 for adjusting the resonance frequency is provided near the anode cylinder 1, and this metal ring 5 also allows the anode vane 2 to be The configuration is such that every other one is shorted.

In this case, by deforming the metal ring 5 as described above separately from the pressure equalizing rings 3 and 4,
Resonant frequency can be adjusted.

Problems to be Solved by the Invention When a magnetron is miniaturized, its resonant frequency tends to shift toward a higher direction. Moreover, as mentioned above, connecting every other large-diameter metal ring along the inner circumferential surface of the anode cylinder to an anode vane at a position away from the anode cylinder requires considerable space constraints. i,l.

Means for Solving the Problems According to the present invention, a pair of metal rings for adjusting the resonant frequency is used, and the metal rings are extended in two stages from the inner circumferential surface of the anode cylinder toward the central axis. The two axial end faces are connected to each anode vane.

Effect With this configuration, the capacitance of the resonant cavity is increased by the pair of metal rings, that is, f = 1
/ Since C at 2πF increases, the resonant frequency f shifts to a lower value, making it easier to set the resonant frequency to a predetermined value when miniaturized.

Embodiments Next, the present invention will be explained with reference to the drawings and embodiments.

As shown in FIG. 1, a large number of anode vanes 2 protrude from the inner circumferential surface of the anode cylinder 1 in the direction of the central axis. Every other one is short-circuited, and two wires are connected from the inner peripheral surface of the anode cylinder 1 to the central axis
A pair of resonant frequency adjustment metal rings 6a protruding from the step
, 6b are electrically connected to the two end faces of all the anode vanes 1, respectively.

Therefore, the capacitance along the inner circumferential surface of the anode cylinder 1 is increased by the pair of metal rings 6a, 6b, and the amount of increase is due to the amount of increase due to the pair of metal rings 6a that are incorporated.

6b is determined by the valley width and mutual spacing. In other words, by arranging a pair of metal rings 6a and 6b of appropriate widths facing each other at an appropriate interval, the resonance frequency can be adjusted by itself, and the adjustment made by deforming the pressure equalizing ring is sufficient as an auxiliary one. .

In the embodiment shown in FIG. 2, two end faces of each anode vane 2 are provided with notches, and metal rings 6a and 6b are fitted into the gauge portions.

Effects of the Invention As described above, according to the present invention, the shift of the resonant frequency toward higher levels due to the miniaturization of the magnetron can be resolved by simply providing a pair of metal rings on the inner peripheral surface of the anode cylinder. In particular, it can facilitate the design of small magnetrons.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of an anode assembly for a magnetron embodying the present invention, FIG. 2 is a side sectional view of another embodiment of the invention, and FIG. 3 is a plan view of a conventional anode assembly for a magnetron. FIG. 4 is a side sectional view of the same anode structure. 1...Anode cylinder body, 2...Anode vane,
3, 4... Equalizing ring, 6a, 6b... Metal ring for adjusting resonance frequency. Name of agent: Patent attorney Shigetaka Awano (1 person)

Claims (1)

[Claims] A large number of anode vanes that protrude from the inner circumferential surface of the anode cylinder toward the central axis side and form a resonant cavity are short-circuited every other time by pressure equalizing rings at two end faces in the axial direction, and the inner circumference of the anode cylinder is A pair of resonant frequency adjustment metal rings protruding in two steps from the surface toward the center axis are provided on all of the anode vanes.
An anode structure for a magnetron characterized by being connected at end faces.