JPH0760642B2 - Magnetron device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a magnetron device comprising a magnetron and excitation means coupled thereto.

2. Description of the Related Art Generally, an annular ferrite magnet is used as an exciting means of a magnetron device for a microwave oven, and this magnet is arranged on a magnetic pole piece located at one end of an anode cylinder of the magnetron. On the other hand, since the anode loss of the magnetron is as large as several hundreds of watts, there is a risk that the ferrite magnet will rise in temperature during operation of the device and cause irreversible demagnetization (hereinafter referred to as high temperature demagnetization). Therefore, many radiating fins are attached to the outer peripheral surface of the anode cylinder in multiple stages and a forced air cooling airflow is circulated between the radiating fins.However, even if such a means is taken, it is still possible. There was a problem that it was difficult.

Further, since the ferrite magnet is relatively fragile, if the annular ferrite magnets stacked on the pole pieces are tightened with a robust frame yoke, there is a risk that the anode cylinder may be damaged due to thermal expansion or the like.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Therefore, an object of the present invention is to provide a high-efficiency magnetron device capable of further suppressing high-temperature demagnetization of a ferrite magnet and preventing the above-mentioned damage of the ferrite magnet. Especially.

Means for Solving the Problems In the magnetron device of the present invention, an annular ferrite magnet is provided outside the anode cylinder on the first pole piece of the magnetron in which a large number of heat radiation fins are mounted in multiple stages on the outer peripheral surface of the anode cylinder. The magnets are arranged coaxially, and one of the magnetic poles of the ferrite magnet is magnetically coupled to the first magnetic pole piece, and the frame-shaped yoke surrounding at least the anode cylinder, the heat radiation fin and the ferrite magnet is used. In the magnetron device in which the other magnetic pole of the ferrite magnet is magnetically coupled to the second magnetic pole piece of the magnetron, and an airflow for air cooling is circulated between the radiating fins, a part of the horizontal wall of the frame-shaped yoke is formed in the frame. A protrusion for contacting a part of the airflow is formed adjacent to the magnet by bending the V-shaped or U-shaped inward of the linear yoke. Of.

Operation With this configuration, the surface area of the frame-shaped yoke that also serves as a heat dissipation blade for the ferrite magnet, that is, the area in contact with the forced air cooling airflow, increases, and the temperature rise of the magnet can be suppressed accordingly. In addition, since the projections provide a cushioning effect on the substantial axial length of the frame yoke, it is possible to prevent the ferrite magnets from being damaged as described above.

Embodiment As shown in FIG. 1, a large number of heat radiation fins 3 attached to the outer peripheral surface of the anode cylinder 2 of the magnetron 1 are arranged in multiple stages so that a forced air cooling airflow passage is formed between the fins. There is. A first annular ferrite magnet 5 is coaxially arranged on a first magnetic pole piece 4 provided at one end of the anode cylinder 2, and one magnetic pole thereof is magnetically coupled to the first magnetic pole piece 4. Has been done. A second annular ferrite magnet 7 is coaxially arranged on a second magnetic pole piece 6 provided at the other end of the anode cylinder 2, and one magnetic pole of the second annular ferrite magnet 7 is magnetically coupled to the second magnetic pole piece 6. Are combined together. Then, the frame-shaped yoke 8 surrounding the anode cylinder 2, the radiation fin 3, and the first and second annular ferrite magnets 5 and 7 causes the other magnetic pole of each of the first and second annular ferrite magnets 5 and 7. They are magnetically coupled to each other.

The frame-shaped yoke 8 includes a first member 9 having a cross section and a second member 9 having a cross section.
It consists of member 10 and both members 9 and 10 are cross-sectioned by screws 11.
They are joined together to form a letter shape. Then, a part of the two horizontal walls in the plane orthogonal to the tube axis of the frame yoke 8
The pair of protrusions 9a and 9b and the pair of protrusions 10a and 10b are formed by bending the inside of the frame into a V shape. As shown in FIG. 2, the pair of protrusions 9a and 9b are press-formed as two strips parallel to both side walls, and are located on both sides of the annular ferrite magnet 5 and contact the outer surface of the ferrite magnet 5. ing. The pair of protrusions 10a and 10b are also formed in the same manner as described above, are located on both sides of the annular ferrite magnet 7, and are in contact with the outer surface of the ferrite magnet 7. The forced air-cooling airflow sent from the fan of the blower (not shown) flows in one direction perpendicular to the paper surface so as to come into contact with the radiating fins 3 and the frame yoke 8.

In the magnetron device configured as described above, the frame yoke 8 also serves as a heat dissipation blade for the ferrite magnets 5 and 7, and the surface area of the frame yoke 8 is a V-shaped protrusion.
9a, 9b, 10a, 10b are enlarged, so that it is possible to suppress the temperature rise of the ferrite magnets 5 and 7 and miniaturize the heat radiation fins without enlarging the outer shape of the frame yoke 8. . Further, as a result of the protrusions 9a, 9b, 10a, 10b providing a cushioning action on the substantial axial length of the frame yoke 8, it is possible to prevent the ferrite magnets 5, 7 from being damaged by axial tightening. Further, since the pair of protrusions 9a and 9b come into contact with the ferrite magnet 5 and the pair of protrusions 10a and 10b come into contact with the ferrite magnet 7 from both sides, positioning of the ferrite magnets 5 and 7 during assembly becomes easy. In addition, it is possible to prevent positional displacement after assembly.

In the above embodiment, V is used to form the protrusions 9a, 9b, 10a, 10b.
Although it is bent in a character shape, it may be a U shape. In addition, the protrusions 9a, 9b, 10a, 10b are connected to the respective ferrite magnets 5, 7
Need not abut, and may also be formed on only one of the two horizontal walls. Further, the present invention is
Needless to say, the present invention can be similarly applied to a device of a type that does not have either one of the second annular ferrite magnet and

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it is possible to suppress the high temperature demagnetization accompanying the temperature rise of the ferrite magnet and downsize the radiation fin without increasing the outer shape of the frame yoke. Not only is it possible, but it is possible to prevent damage due to axial tightening of the ferrite magnet.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a magnetron device embodying the present invention, and FIG. 2 is an exploded perspective view of a main part of the device. 1 ... Magnetron, 2 ... Anode cylinder, 3 ... Radiating fin, 4,6 ... Pole piece, 5,7 ... Ferrite magnet, 8 ... Frame yoke, 9a, 9b, 10a, 10b ... … Protrusion.

Claims (1)

[Claims] 1. An annular ferrite magnet is coaxially arranged outside the anode cylinder on a first magnetic pole piece of a magnetron in which a large number of heat radiation fins are mounted in multiple stages on the outer peripheral surface of the anode cylinder. One magnetic pole is magnetically coupled to the first magnetic pole piece, and the other magnetic pole of the ferrite magnet is connected to the magnetron by a frame yoke surrounding at least the anode cylinder, the heat radiation fin and the ferrite magnet. In a magnetron device magnetically coupled to a second magnetic pole piece and allowing an air-cooling airflow to flow between the radiation fins, a part of a horizontal wall of the frame-shaped yoke is inwardly V-shaped to the inside of the frame-shaped yoke. A magnetron device characterized in that a protrusion for contacting a part of the air flow is formed adjacent to the magnet by bending the magnet in a U shape.