JPH0418661B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a forced air-cooled magnetron device used in microwave ovens and the like.

BACKGROUND TECHNOLOGY In general, a forced air-cooled magnetron device used in a microwave oven, etc. has a large number of heat dissipation vanes attached in multiple stages to the outer peripheral surface of the anode cylinder of the magnetron, and forced air cooling air flows between the heat dissipation vanes. It is configured to distribute. Therefore, the temperature rise of the magnetron during operation is alleviated, and it is possible to prevent the magnetron from becoming inoperable due to abnormally high temperatures and from high-temperature demagnetization of the excitation permanent magnet.

Problems to be Solved by the Invention Incidentally, in order to further reduce the size, weight, and cost of magnetron devices, it is necessary to improve air cooling efficiency. FIG. 5 shows the flow path of the forced air cooling airflow in a conventional magnetron device, where the forced air cooling airflow 2 flowing between the plates of the heat dissipation vanes 1 flows on both sides in the vicinity of the anode cylinder 3 of the magnetron. There was a problem in that it was difficult to efficiently air cool the anode cylinder, which is naturally hot. In addition, 6 in the figure is the heat dissipation vane plate 1.
The cylindrical part for penetrating the anode cylinder body, 5 indicates the side wall part of the frame-shaped yoke.

Furthermore, the cylindrical portion 14 of the heat dissipating vane 1 attached to the outer peripheral surface of the anode cylinder 3 by a method such as press-fitting tends to overlap with the cylindrical portion 4 of the heat dissipating vane 1 that is subsequently attached due to changes over time. If this happens, not only will the spacing between the heat dissipation vanes vary, but the cylindrical portion 4 will not be able to be brought into close contact with the anode cylinder 3 over a wide area, making it difficult to obtain a good heat dissipation effect.

Means for Solving the Problems According to the present invention, the outer magnetic pole of the annular permanent magnet coaxially stacked on one magnetic pole part of the magnetron is connected to the other magnetic pole part of the magnetron via a frame-shaped yoke. A radiator that is magnetically coupled and attached to the outer circumferential surface of the anode cylinder of the magnetron bridges the horizontal blade sections arranged in multiple stages through a flow passage for forced air cooling. In the magnetron device, the vertical wing section has a cylindrical section through which the horizontal wing section penetrates the anode cylinder, and both end sections contact both side walls of the yoke. is integrally molded with the horizontal wing portion. In order to ensure that the mutual spacing between the horizontal wing parts is greater than or equal to the axial length of the cylindrical part, the vertical wing parts are provided on both side walls between each side wall of the yoke and the cylindrical part. Forms parallel partition walls.

Furthermore, not only can the radiator be efficiently manufactured mainly by extrusion molding, but also the magnetron can be press-fitted into the cylindrical portion of the radiator all at once. Furthermore, since the cylindrical portions do not overlap each other, the radiator can be brought into close contact with the anode cylindrical body of the magnetron over a wide area.

Embodiments Next, the present invention will be described in detail with reference to embodiments shown in the drawings.

In FIG. 1, a radiator 7 attached to the outer peripheral surface of an anode cylinder of a magnetron 6 is made of aluminum or an alloy thereof, and has a cross-sectional shape as shown in FIG. Each horizontal blade part 8 of the radiator 7 is arranged in multiple stages via a forced air cooling air flow path, and each horizontal blade part 8 has a cylindrical part 9 for penetrating the anode cylinder of the magnetron 6.
is formed. Further, a pair of vertical wing sections 10 that bridge the horizontal wing sections 8 to each other are integrally provided between the horizontal wing sections, and the mutual spacing of the horizontal wing sections 8 is regulated by the vertical wing sections 10. Ru. That is, the mutual spacing between the horizontal wing sections is ensured by the vertical wing section 10 to a dimension equal to or longer than the axial length of the cylindrical section 9. Cylindrical part 9
The shortest distance A between the vertical wing portion 10 and the vertical wing portion 10 is set to 10 to 30% of the outer diameter B of the cylindrical portion 9.

Such a radiator 7 can be obtained relatively inexpensively by cutting a long piece formed by extrusion molding to a predetermined size and then forming the cylindrical part 9 by press working. Note that an annular permanent magnet (not shown) is coaxially stacked on one magnetic pole portion 11 of the magnetron 6, and the outer magnetic pole of this magnet is connected to the outer magnetic pole of another annular permanent magnet 13 through a frame-shaped yoke 12. The inner magnetic pole of the magnet 13 is magnetically coupled to the other magnetic pole portion of the magnetron 6.

As shown in FIG. 3, of the forced air cooling airflow 14 flowing between the horizontal blades 8 of the radiator 7, the air that enters between the pair of vertical blades 10, 10 is near the anode cylinder of the magnetron 6. However, due to the partitioning effect of the pair of vertical wing sections 10, 10, the flow was not deflected significantly to both sides, and instead proceeded at a high density in the narrow part between the anode cylinder and the vertical wing section 10. Later, it turns drastically inward. Therefore, the entire circumference of the anode cylinder of the magnetron 6 and the radiator portion in the vicinity can be better air-cooled. Further, the air cooling air flowing between the vertical wing section 10 and the side wall of the frame-shaped yoke 12 travels straight along the vertical wing section 10, and the radiator section in this region is also appropriately air-cooled. In combination with the expansion of the heat radiation area by the wing portion 10, a good heat radiation effect can be obtained.

When the shortest distance A between the cylindrical portion 9 and the vertical wing portion 10 becomes less than 10% of the outer diameter B of the cylindrical portion 9, air resistance at the shortest distance A increases, and the pair of vertical wing portions 10, 1
This causes a decrease in the airflow for cooling that flows in between zero and zero. Furthermore, if the shortest interval A exceeds 30% of the outer diameter B, the airflow that goes around to the back side of the anode cylinder will decrease.

Figure 4 shows the A/B value vs. anode cylinder temperature characteristics based on the experimental results, and from this, A/B = 10 ~
30% (for example, B value at A = 40 mm is 4 mm to 12
mm), the anode cylinder temperature can be lowered by 15 to 25 degrees Celsius compared to the conventional one (B = approximately 25 mm), and A/B = 15 to 25
%, it can be seen that the temperature can be lowered by about 25℃.

Effects of the Invention As described above, according to the present invention, an efficient air cooling effect can be obtained by simply modifying the radiator by adding vertical blades. It can be obtained relatively inexpensively by processing.
Furthermore, there is also the advantage that the work of attaching the radiator to the anode cylinder by a method such as press fitting is simplified.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a magnetron device embodying the present invention, FIG. 2 is a side sectional view of a radiator of the device, FIG. FIG. 4 is an A/B value-anode cylinder temperature characteristic diagram for explaining the effects of the present invention, and FIG. 5 is a plan view showing a flow path of air cooling air in a conventional magnetron device. 6... Magnetron, 7... Radiator, 8...
...Horizontal wing section, 9... Cylindrical section, 10... Vertical wing section.

Claims (1)

[Claims] 1. The outer magnetic pole of an annular permanent magnet coaxially stacked on one magnetic pole part of the magnetron is magnetically coupled to the other magnetic pole part of the magnetron via a frame-shaped yoke, and the anode cylindrical body of the magnetron A radiator attached to the outer circumferential surface of the horizontal blade has horizontal blade sections arranged in multiple stages via forced air cooling air flow passages, and a vertical blade section that bridges the horizontal wing sections. In the magnetron device, the wing portion has a cylindrical portion that penetrates the anode cylinder, and both end portions contacting both side walls of the yoke, wherein the vertical wing portion is integrally molded with the horizontal wing portion. , in order to ensure that the mutual spacing between the horizontal wing portions is greater than or equal to the axial length of the cylindrical portion, partition walls are formed between both side walls of the yoke and the cylindrical portion along the both side walls; A magnetron device characterized by: