JPS61285635A - Magnetron device - Google Patents

Abstract

PURPOSE:To check demagnetization in accompany with temperature rise of a frame-shaped yoke, namely, that of a permanent magnet by forming the part corresponding to the side wall of the frame-shaped yoke of four vertical wing parts so as to make said vertical wing parts to lie on the line radially drawn from the tube axis of a magnetron in four directions and to come in contact with a radiation fin while passing through said radiation fin. CONSTITUTION:A frame-shaped yoke for magnetically combining the other side magnetic pole S of the first permanent magnet 3 with the other magnetic pole N of the second permanent magnet 5 consists of the frame body part 6 and the top plate part 7 to be combined with it. The frame body part 6 consists of the bottom plate part 8 and the four vertical wing parts 9-12 raised from it by cutting, while the vertical wing parts 9-12 are situated on the line radially drawn from the tube axis of a magnetron 1 in four directions at the intervals of 45 deg. and brought in contact with the first and second permanent magnets 3 and 5 on their inner surfaces. Further, the radiation fin 15 and the vertical wing parts are so made as to maintain contact relation, where the tongue-shaped projections 20 raised by cutting when forming the slits of the former are closely and elastically in contact the surfaces of the latter.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetron device comprising a magnetron and its exterior member.

2. Description of the Related Art In general, a magnetron device used in a microwave oven or the like consists of a magnetron and its exterior member, and the exterior member includes an excitation circuit member, a cathode filter circuit member, a shield case, a heat radiation fin, and the like. The excitation circuit member includes an annular permanent magnet stacked on a first magnetic pole piece of the magnetron and having one magnetic pole magnetically coupled to the magnetic pole piece, and the other magnetic pole of this permanent magnet stacked on a first magnetic pole piece of the magnetron. The shield case is attached to one end surface of the frame yoke and is connected to the cathode terminal of the magnetron and the same cathode terminal. The choke coil and feedthrough capacitor, which are the filter circuit members, are housed therein. Further, the heat radiation fins are attached to the outer peripheral surface of the anode portion of the magnetron in multiple stages, and a forced air cooling airflow flows between the heat radiation fins.

Problems to be Solved by the Invention However, in the conventional magnetron device as described above, since the frame-shaped yoke has a cross-sectional shape, the flow direction of the forced air cooling airflow flowing through the frame-shaped yoke is limited. is also limited to one specific direction. On the other hand, the space for installing the magnetron device in a set such as a microwave oven is limited, and this differs depending on the model, so even if the relationship between the direction of the frame-shaped yoke and the direction in which the terminals of the feedthrough capacitor are drawn out is limited, It was uneconomical that many types of magnetron devices had to be manufactured and prepared in order to be applicable to many types of sets. Further, although the forced air cooling air flow flows along both side walls of the frame-shaped yoke, the degree of contact with the side walls is low, and for this reason, there is a problem in that it is difficult to air-cool the yoke sufficiently.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a highly efficient magnetron device in which the flow direction of the forced air cooling airflow is not specified, and the frame-shaped yoke can be better air-cooled by the forced air cooling airflow.

Means for Solving the Problems According to the present invention, the portion corresponding to the side wall of the frame-shaped yoke is
Formed with two vertical wings. However, this vertical wing portion is located on a line drawn radially in four directions from the tube axis of the magnetron, penetrates through the radiation fins, and comes into contact with the radiation fins.

Function: With this configuration, the direction in which the forced air cooling air flow is sent is not specified, and the degree of contact between the air flow and the frame-shaped yoke can be increased. Moreover, the area where the permanent magnet and the frame-shaped yoke are close to each other can be reduced, and excitation efficiency can be increased.

Embodiment In FIGS. 1 and 2 showing an embodiment of the present invention,
The first permanent magnet is a three-piece ferrite annular ring that is coaxially stacked on the outer end surface of the first magnetic pole piece 2 of the magnetron 1, and as a result of the stacking, one magnetic pole N is magnetically attached to the first magnetic pole piece 2. are combined. Also, magnetron 1
The second permanent magnet 5 coaxially superimposed on the outer end surface of the second magnetic pole piece 4 is also made of ferrite and has an annular shape. are combined. A frame-shaped yoke for magnetically coupling the other magnetic pole S of the first permanent magnet 3 to the other magnetic pole N of the second permanent magnet 6, a frame portion 6, and a frame portion coupled thereto. It consists of a plate part 7.

Consisting of a frame body part 6 bottom plate part 8 and four vertical wing parts 9, 10, 11.12 cut and raised from this, the vertical wing parts 9, 10, 11.12 parts are 4 from the tube axis of the magnetron 1. It is located on a line drawn radially in the direction at intervals of 46', and is in contact with the first and second permanent magnets 3 and 5 on its inner surface.

In addition, there are 7 top plate parts and 4 vertical wing parts 9, 10° 11.1
16 aluminum heat dissipation fins, vertical wing parts 9, 10, which have cut and raised parts 13 connected to each tip of the magnetron 1, and are attached in multiple stages to the outer peripheral surface of the anode part 14 of the magnetron 1.
, 11, 12 and has four slits 16 for penetrating and contacting them. A shield case 17 attached to the bottom plate part 8 of the frame part 6 houses a cathode terminal lead-out stem part 18 of the magnetron 1 and an La filter circuit member connected to the terminal. A feedthrough capacitor 19 is attached to one side of the seal case 17.

An example of a structure in which the top plate portion 17 and the vertical wing portion 11 are fixed by caulking is illustrated in FIG. Although not shown in FIGS. 1 and 2, the tongue-like projections 20 cut and raised when forming the slits 16 of the former, as illustrated in FIG. The contact relationship is maintained by elastically abutting the latter surface.

According to such a configuration, the forced air cooling airflow supplied from the direction shown by the solid line arrow in FIG. can be sufficiently air cooled. Furthermore, even if the supply direction of the forced air cooling airflow is changed by 900 degrees, the same effect as described above can be obtained, so a degree of freedom is given to the directionality, and the compatibility of the device is expanded. In addition, since the permanent magnets 3゜6 and the vertical blades 9, 10, 11, 12 are close to each other only in a small portion, magnetic flux leakage due to their proximity is reduced, and excitation efficiency can be increased. can. Furthermore, by bringing the four vertical wings 9, 1011.12 into contact with both permanent magnets 3, 6 as described above, not only the positioning of the permanent magnets becomes easy, but also the A decrease in excitation efficiency can be prevented.

Effects of the Invention Since the present invention is constructed as described above, it is possible not only to suppress the demagnetization caused by the temperature rise of the frame-shaped yoke and therefore the temperature rise of the permanent magnet, but also to expand the compatibility of the device. It has excellent effects, such as being able to reduce magnetic flux leakage due to the shaped yoke.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a magnetron device embodying the present invention, FIG. 2 is an exploded perspective view of mainly a frame-shaped yoke of the same device,
3 and 4 are perspective views showing a partially assembled state of the device, and FIG. 6 is a schematic diagram mainly for explaining the air cooling air flow passage of the device. 1... Magnetron, 3, 5... Permanent magnet, 6... Frame part of frame-shaped yoke, 7...
...Top plate part, 9゜10.11.12...Vertical wing part of frame part, 16...Radiation fin. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3

Claims (1)

[Claims] a frame joint for magnetically coupling the other pole of an annular permanent magnet stacked on a first pole piece of the magnetron to magnetically couple one pole to the second pole piece of the magnetron; The iron has four vertical wing parts located on lines drawn radially in four directions from the tube axis of the magnetron, and the vertical wing parts have heat dissipation fins attached in multiple stages to the outer peripheral surface of the anode part of the magnetron. A magnetron device characterized by penetrating the same and being in contact with the same heat dissipation fin.