JPH012240A - magnetron device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetron device used in microwave heating equipment such as a microwave oven.

2. Description of the Related Art Generally, a magnetron device used in a microwave heating device such as a microwave oven is constructed as shown in FIG. That is, the magnetron 1 has a cathode 3 disposed coaxially within a cylindrical anode body 2, and has first and second magnetic pole pieces 4.5 at both open ends of the anode body 2. ing. The eyelet-shaped metal tube 6 provided on the first magnetic pole piece 4 is
It has a 7-run part that covers the magnetic pole piece 4, and is welded to the anode cylinder 2 at the outer peripheral edge of this flange part. And metal pipe 6
A microwave deriving conductor 10 extending from an anode vane 9 is connected to a metal exhaust pipe 8 sealed via an insulating tube 7 to the exhaust pipe 8, and a metal cap serving as a microwave output terminal is connected to the exhaust pipe 8. The body 11 is fitted. Further, a stem 13 for leading out a cathode terminal is sealed to an eyelet-shaped metal tube 12 that covers the second magnetic pole piece 5 with a flange portion.

A first annular permanent magnet 14 coaxially stacked on the first pole piece 4 in surrounding relation to the metal tube 6 magnetically couples one magnetic pole N to the first pole piece 4. , metal tube 1
A second annular permanent magnet 15 coaxially superposed on the second pole piece 5 in surrounding relation to the second pole piece 5 magnetically couples one of the magnetic poles S to the second pole piece 5 . The frame-shaped yoke 16 that magnetically couples the other magnetic poles S and N of the first and second annular permanent magnets 14.15 has a through hole 17 through which the metal tube 6 is inserted, and a metal tube It has a hole 18 for inserting the tube 12 therethrough.

A thin shield plate 1 made of magnetic metal provided between the top surface of the first annular permanent magnet 14 and the top plate of the frame-shaped yoke 16
9 is fitted onto the outer peripheral surface of the metal tube 6 so as to surround the metal tube 6, and an annular gasket 20 is housed in the opening 17. This gasket 20, which is made of a braided body of thin metal wires, is located on the shield plate 19 so as to surround the metal tube 6, and the cylindrical opening 22 of the waveguide 21 leading to a heating chamber such as a microwave oven is It is in contact with the gasket 20 so as to bite into it. Reference numeral 23 indicates a heat radiation fin, and 24 indicates a shielding case.

Problems to be Solved by the Invention In the conventional magnetron device configured as described above, microwaves emitted from the metal cap body 11 are transmitted through the waveguide 2.
The gasket 20 prevents the microwaves sent from the magnetron device into the waveguide 21 from leaking at the joint between the two. Therefore, the cylindrical opening 22 of the waveguide 21 must be in strong contact with the surface of the gasket 20 so as to bite into it, but since the gasket 20 is made of a braided body of thin metal wires as described above, it is necessary to make such contact with the surface of the gasket 20. Easy to loosen due to deformation due to contact. In particular, as shown in FIG. 4, when the whisker-like protrusions 20a produced by the separation protrude toward the metal cap body 11 side, this acts as a trigger electrode, and a gap between the metal tube 6 and the metal cap body 11 is generated. This creates a dangerous situation where sparks are likely to occur.

Means for Solving the Problems The present invention has been made in order to eliminate such conventional dangers. The braiding density is higher than that in the area where the shaped opening abuts.

Function: With this configuration, the gasket function can be reduced (unraveling at the inner peripheral edge of the gasket can be reduced,
The generation of sparks as described above can be prevented.

Further, the occurrence of warpage in the gasket is reduced, and displacement or falling off due to this warpage can be prevented.

Example A magnetron device embodying the present invention is shown in Figs. 1 and 2.
It is configured as shown in the figure. The difference between the configuration shown here and the conventional configuration shown in FIG. 3 is that the gasket 25
However, in the inner circumferential edge region 26, m pairs are arranged at a higher density than in the remaining region 27. That is, approximately 0.
The gasket 25 is made by braiding stainless steel wire or brass wire having a wire diameter of 0.05 to 0.2 mm into a circular shape.
The gasket has an inner circumferential edge region 27 that is braided with a higher braiding density than the braiding density of the region 27 in contact with the cylindrical opening 22 of the waveguide. can be formed with. In addition, by combining small-diameter and large-diameter annular braided bodies formed using different braiding conditions and materials,
It can also be obtained by combining. moreover,
It is not necessary to braid the entire area of the inner peripheral edge region 27 with high density (
It may be partially braided with high density.

Effects of the Invention Since the present invention is configured as described above, it is possible to reduce the loosening of the gasket, particularly at the inner peripheral edge, which is caused by bringing the cylindrical opening of the waveguide into strong contact with the gasket. It is possible to prevent the generation of sparks as described above due to loosening.Furthermore, since the degree of warping of the gasket can be reduced, it is possible to prevent the gasket from shifting or falling off.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of the main parts of a magnetron device embodying the present invention, Fig. 2 is a perspective view of a gasket of the same device, Fig. 3 is a partially cutaway side view of a conventional magnetron device, and Fig. 4 is FIG. 3 is a side sectional view illustrating a deformed state of the gasket of the device. 1... Magnetron, 2... Anode tube, 4... Magnetic pole piece, 6... Metal tube, 11
...Metal cap body, 14...Annular permanent magnet, 16...Frame-shaped yoke, 21...Waveguide, 25... - Gasket, 26... Cylindrical opening of the gasket. Name of agent: Patent attorney Toshio Nakao and one other person

Claims (1)

[Claims] A magnetron having first and second magnetic pole pieces at both open ends of an anode cylinder, and a microwave output terminal protruding from a metal tube provided on the first magnetic pole piece through an insulating tube. an annular permanent magnet coaxially stacked on the first pole piece in surrounding relation to the metal tube and having one magnetic pole magnetically coupled to the first pole piece; a frame-shaped yoke for magnetically coupling a magnetic pole to the second magnetic pole piece; and a frame-shaped yoke provided on the permanent magnet in a relationship surrounding the metal tube so as to be able to abut against the cylindrical opening of the waveguide. and an annular gasket housed in the opening of the frame-shaped yoke, the gasket being made of a braided body of thin metal wires, the braiding having a higher density than the region abutting the cylindrical opening of the waveguide. What is claimed is: 1. A magnetron device having an inner circumferential edge region.