JPH038242A - Magnetron for microwave oven - Google Patents

Abstract

PURPOSE:To improve cooling efficiency with a simple structure by setting the height of claws between laminated cooling fins to the preset height. CONSTITUTION:Multiple cooling fins 2 are laminated around an anode cylinder 1, and cooling air is circulated between their layers. A short cylinder section 3 is formed on the outside of the anode cylinder 1, and the cooling fins 2 are pressed on it and laminated so that the interval between layers is determined by claws 15 on fin outside sections. The claws 15 are simply formed by cutting the cooling fins 2, and the height B is set larger than the height C of the short cylinder section 3. The cooling fins 2 are inclined and arranged so that the inter-layer interval is increased as they are separated from the anode cylinder 1 after they are laminated. The area of the intake port of the cooling air is increased, and cooling efficiency is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Industrial Application Field) This invention relates to a magnetron for a microwave oven, and particularly relates to an improvement in the laminated structure of cooling fins.

(Prior Art) Generally, magnetrons are widely used in microwave ovens and the like, and this type of magnetron has conventionally been constructed as shown in FIGS. 2 and 3. That is, on the outer periphery of the anode cylinder 1 of the magnetron, a plurality of plate-shaped cooling tubes 2, which are called side-blown cooling tubes, are press-fitted and stacked at predetermined intervals.

In this case, in order to keep the mutual spacing at a predetermined dimension, each cooling fin 2 is integrally formed with a short cylindrical part 3 that contacts the outer periphery of the anode cylinder 1, and a total of 4 short cylindrical parts 3 are formed in each of the vicinity of the population and the outlet of the cooling air. Furthermore, bent portions 5 are integrally formed on two opposing sides, and these short cylindrical portions 3, claws 4, and bent portions 5 maintain a predetermined interval. ,
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In FIGS. 2 and 3, reference numeral 6 is a vane, 7.8 is a pole piece, 9.10 is a part of the cylindrical body, 11.12 is a magnet, and 13.14 is a yoke.

Further, in FIG. 2, the magnets and yokes are omitted for convenience.

(Problem 8 to be solved by the invention) However, in recent years, magnetrons have been increasingly required to be made more and more inexpensive, and in order to meet this demand, magnetrons have been made smaller. Therefore, since the anode cylinder 1 into which the cooling fins 2 are press-fitted also becomes smaller, the press-fitted portions of the plurality of cooling fins 2 become narrower, and as a result, the mutual spacing between the cooling fins 2 becomes narrower.

If the mutual spacing between the cooling fins 2 is narrow, it becomes difficult to take in cooling air effectively. As a result, the cooling effect is reduced and the anode temperature increases, making it impossible to ensure reliability.

This invention was made to improve the above-mentioned drawbacks of the prior art, and provides a magnetron for microwave ovens that has a large opening area for introducing cooling air and does not cause a decrease in cooling capacity. is intended to provide.

[Structure of the Invention (Means for Solving the Problem) In this invention, a cooling fin that is press-fitted into an anode cylinder is provided with a pawl and a short cylindrical portion, and the length of the pawl is equal to the length of the short cylindrical portion. This is a magnetron for a microwave oven in which the distance between the cooling fins increases from the short tube side to the claw side.

(Function) According to the present invention, since the cooling air intake is expanded, the cooling air flowing into the inner space of the yoke can be effectively utilized. As a result, heat dissipation is improved and reliability is also increased.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

The magnetron for a microwave oven of the present invention is constructed as shown in FIG. 1, and the same parts as in the conventional example (FIGS. 2 and 3) are given the same reference numerals.

That is, a plurality of cooling fins 2 are press-fitted and stacked at predetermined intervals on the outer periphery of the anode cylinder l of the magnetron.

In this case, the cooling fins 2 are plate-shaped, and bent portions 5 (see FIG. 2) are integrally formed on two opposing sides. A short cylindrical portion 3 is integrally provided in the vicinity of the inner center of the negative side in the same direction as the bent portion 5.

Further, on the outside of the cooling fins 2, that is, near the inlet and the outlet of the cooling air, a plurality of claws 15, for example, a total of four claws 15, are cut and raised in a direction parallel to the tube axis. This claw 15 is different from the conventional one in that its length B is set larger than the length C of the short cylindrical portion 3 (B>C).

Therefore, when the short cylindrical portions 3 of the plurality of cooling fins 2 are press-fitted into the outer periphery of the anode cylinder 1 of the magnetron, as is clear from FIG. The claws will automatically expand from the cylindrical part 3 side to the 5 side.

Although FIG. 1 only shows approximately the right half of the magnetron for convenience, the left half is constructed in the same way as the right half, and even if flat cooling fins 2 are used, both wings are automatically expanded. can be easily done.

In this way, the cooling air intake port can be easily expanded by mechanical press-fitting as in the conventional method, and heat dissipation is significantly improved.

Since the configuration other than the above is the same as that of the conventional example, the same parts are given the same reference numerals and detailed explanations will be omitted.

[Effects of the Invention] As explained above, according to the present invention, the length of the claw of the cooling fin is set larger than the length of the short cylinder part, and the mutual interval between the cooling fins press-fitted into the anode cylinder is shortened. Since the cooling fins widen from the cylindrical side to the claw side, both wings of the cooling fin automatically expand when press-fitted.

That is, even if N-shaped flat cooling fins are used, both wings can be automatically expanded, and the opening area for taking in the cooling air can be increased. As a result, the cooling air flowing into the inner space of the yoke can be effectively used for heat radiation, thereby improving heat radiation performance and increasing reliability.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a longitudinal sectional view showing a magnetron for a microwave oven according to an embodiment of the present invention, FIG. 2 is a perspective view showing a conventional magnetron for a microwave oven, and FIG. FIG. 2 is a longitudinal cross-sectional view taken along line A-A in the figure and viewed in the direction of the arrow. 1...Anode cylinder, 2...Cooling fin, 3...Short cylinder part, 15. Claw.

Claims (1)

[Claims] A plurality of plate-shaped cooling fins each having a short cylindrical portion on the inside and claws extending parallel to the tube axis on the outside are press-fitted and laminated on the outer periphery of an anode cylinder with a space maintained between the short cylindrical portions and the claws. In the microwave oven magnetron, the length of the claw is set larger than the length of the short cylindrical portion, and the distance between the cooling fins press-fitted into the anode cylinder increases from the short cylindrical portion side to the claw side. A magnetron for microwave ovens.