JP2000285817A - Magnetron device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetron device which has a high cooling effect of a cylindrical positive electrode body by improving an adherence of a cooling block with the cylindrical positive electrode body with a simple structure. SOLUTION: This device has therein a cooling block 1a having a liquid flow path formed so as to surround a cylindrical positive electrode body 3 and a frame-shaped yoke connected to the cooling block 1a. An engagement of an outer diameter of the cylindrical positive electrode body 3 and an inner diameter of the cooling block 1a is a closely fitted type. The cooling block 1a is insertedly fixed to the cylindrical positive electrode body 3 by utilizing a heat characteristic of either thermal shrinkage of the cylindrical positive electrode body 3 or thermal expansion of the cooling block 1a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-cooled magnetron device used for industrial microwave heating.

[0002]

2. Description of the Related Art Generally, a magnetron device used in a home microwave oven or the like is provided with a plurality of heat radiating plates made of metal such as aluminum because the temperature of the magnetron device becomes high when the microwave oven is used. It is cooled by forcing air into it. However, a magnetron device for industrial heating has an output of 1.5 kW.
Since the output of the magnetron device is larger than the output of 0.9 kW of the magnetron device frequently used in home microwave ovens, the heat radiation plate becomes large in the air cooling type. Further, when used for industrial purposes, dust is scattered by a forced air flow in an air-cooled system. Cooling system is used.

Further, as shown in FIGS. 8 and 9, a cooling block 1 and a cooling block having a liquid flow passage 2 formed therein so as to surround a cylindrical anode body 3 are provided. 1 is provided with a frame-shaped yoke 4 connected thereto. The cooling block 1 is formed in a U-shape using a metal lump of a copper alloy, and is fixed to the cylindrical anode body 3 by tightening a U-shaped tip portion with a screw 5. At this time, the cooling block 1 is in contact with the frame yoke 4.

[0004]

However, in the magnetron device in which the cooling block 1 is fixedly fastened to the cylindrical anode body 3 with screws 5, FIG. 10 (a) or FIG.
As shown in (b), the cooling block 1 is mechanically deformed by tightening the screw 5 or the like, and the inner peripheral surface of the cooling block 1 does not adhere to the outer peripheral surface of the cylindrical anode body 3. However, there is a problem that the cooling effect is reduced.

The present invention provides a magnetron device which has a simple structure, improves the adhesion between a cooling block and a cylindrical anode body, and has a high cooling effect on the cylindrical anode body.

[0006]

SUMMARY OF THE INVENTION A magnetron device according to the present invention comprises a cooling block having a liquid flow passage formed therein so as to surround a cylindrical anode body, and a frame-shaped yoke connected to the cooling block. In the magnetron device provided, the fit between the outer diameter of the cylindrical anode body and the inner diameter of the cooling block is tightly fitted, and whether the cylindrical anode body is thermally contracted or the cooling block is thermally expanded. The cooling block is inserted and fixed to the cylindrical anode body by utilizing one of the thermal characteristics.

With this structure, almost the entire outer peripheral surface of the cylindrical anode body comes into contact with the inner peripheral surface of the cooling block, and the heat generated inside the cylindrical anode body is sufficiently transmitted to the cooling block. .

[0008] The cooling block is connected to a frame yoke through a spacer formed of a metal plate.

With this configuration, the size of the cooling block is reduced by the amount of the spacer, and the weight of the magnetron device can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. For easy understanding, the same parts as those of the above-described prior art are denoted by the same reference numerals and description thereof will be omitted.

(First Embodiment) As shown in FIG.
The magnetron device according to the first embodiment of the present invention includes a cylindrical anode body 3, a cooling block 1a formed so as to surround the cylindrical anode body 3, and a frame yoke 4 to which the cooling block 1a is connected. And

The cooling block 1a is, as shown in FIG.
It has a cylindrical hole 10 in the center and a liquid flow passage 2 is provided inside the cooling block 1a. The screw 11 is for sealing the liquid flow path 2 after the liquid flow path 2 is manufactured.

When the cooling block 1a is inserted into and fixed to the cylindrical anode body 3, a loose fit (the maximum dimension of the outer diameter D2 of the cylindrical anode body 3 is smaller than the minimum dimension of the inner diameter D1 of the cooling block 1a). After the cooling block 1a is inserted into the cylindrical anode body 3, the interference fit is performed (the relationship is that the minimum dimension of the outer diameter D2 of the cylindrical anode body 3 is larger than the maximum dimension of the inner diameter D1 of the cooling block 1a). By doing so, the assemblability is improved. For example, when the cooling block 1a is inserted into the cylindrical anode body 3, either the cylindrical anode body 3 alone is thermally contracted in liquid nitrogen or only the cooling block 1a is thermally expanded in a heating furnace. Utilizing the thermal characteristics described above, the fit between the cooling block 1a and the cylindrical anode body 3 is loosely fitted. Then, the cooling block 1a
By keeping the cylindrical anode body 3 at room temperature, the fit between the cooling block 1a and the cylindrical anode body 3 is tightly fitted.

The cylindrical anode body 3 is a portion which is heated by electron impact for generating microwaves, cavity surface loss, heat radiation from a cathode or the like, and is formed of copper or a copper alloy. . The cooling block 1a is formed of a material having a thermal expansion coefficient equivalent to that of the cylindrical anode body 3, for example, copper or a copper alloy.

Next, the operation and effect of the first embodiment of the present invention will be described.

In the magnetron device of the present invention, the outer diameter D2 of the cylindrical anode body 3 and the inner diameter D1 of the cooling block 1a are tightly fitted, and the cylindrical anode body 3 is thermally contracted or cooled. The cooling block 1a is inserted into and fixed to the cylindrical anode body 3 by utilizing one of the thermal characteristics of thermal expansion of the cooling block 1a, that is, when the cooling block 1a is inserted into the cylindrical anode body 3. By using the one of the thermal characteristics, the fit between the cooling block 1a and the cylindrical anode body 3 is loosely fitted to improve the assemblability, and then the temperature is reduced to room temperature, as shown in FIG. like,
The fit between the cooling block 1a and the cylindrical anode body 3 is a close fit, and almost the entire outer peripheral surface of the cylindrical anode body 3 can contact the inner peripheral surface of the cooling block 1a. As a result, the outer diameter D2 of the cylindrical anode body 3 and the cooling block 1
With a simple structure in which only the dimension of the inner diameter D1 of a is controlled, the heat of the cylindrical anode body 3 generated during the operation of the magnetron device is sufficiently transmitted to the cooling block 1a, and the cooling effect can be enhanced.

Further, since the outer diameter D2 of the cylindrical anode body 3 and the inner diameter of the cooling block 1a are formed of materials having the same thermal expansion coefficient, the temperature of the cylindrical anode body 3 rises during the operation of the magnetron device. Also, the contact state between substantially the entire outer peripheral surface of the cylindrical anode body 3 and the inner peripheral surface of the cooling block 1a does not change. As a result, the cooling effect of the cylindrical anode body 3 can be kept constant.

[0018]

Next, an embodiment in which the effect of the present invention has been confirmed will be described.

The magnetron device according to the embodiment of the present invention has the structure shown in FIG. 1. The inner diameter D1 of the cylindrical hole 10 of the cooling block 1a shown in FIG. 0.05 than D2 (for example, φ49.8 mm)
It is designed to be 0.1 mm smaller. When inserting the cylindrical anode body 3 into the cooling block 1a, the cylindrical anode body 3 is kept at room temperature in advance, and the cooling block 1a is kept at 200 ° C. in a heating furnace. And the cooling block 1
a is taken out of the heating furnace, and the cylindrical anode body 3 is immediately replaced with the cylindrical hole 1 which has been enlarged by the thermal expansion of the cooling block 1a.
Return to room temperature after inserting into 0. When the cooling block 1a, the cylindrical anode body 3 and the like reach room temperature, the cylindrical hole 10 of the cooling block 1a shrinks, and the cylindrical anode body 3 is fixed without moving in the cylindrical hole 10 of the cooling block 1a. (See FIG. 3). Thereafter, components such as the frame-shaped yoke 4 and the like were assembled to manufacture a magnetron device (hereinafter, this magnetron device is referred to as "the present invention").

For comparison, a magnetron device having the same configuration as the above was manufactured by replacing the cooling block 1a with a cooling block 1 having a structure shown in FIG. 9 (hereinafter, this magnetron device is referred to as "conventional magnetron device"). Product)).

Subsequently, regarding the product of the present invention and the conventional product,
When the temperature of the cylindrical anode body 3 during microwave oscillation with 100 samples was examined, the following results were obtained. FIG. 4 shows a temperature distribution of the cylindrical anode body 3. In the figure, A indicates the product of the present invention, and B indicates the conventional product.
The temperature is measured, for example, as shown in FIG. 5, through hole 1 for inserting thermocouple 9 into cooling block 1a (1).
2, the thermocouple 9 was brought into contact with the outer circumferential surface of the cylindrical anode body 3.

As shown in FIG. 4, the average temperature of the cylindrical anode body 3 was 70.3 ° C. for the product 1 of the present invention, whereas it was 75 ° C. for the conventional product. Therefore, it is understood that the product of the present invention can reduce the temperature rise of the cylindrical anode body 3 by about 5 ° C. as compared with the conventional product.

(Second Embodiment) FIG. 6 shows a second embodiment of the present invention.
This embodiment is different from the first embodiment in that the cooling block 1b shown in FIG. 7 has a frame via a spacer 8 formed of a metal plate made of aluminum. The difference is that it is connected to the yoke 4.

According to this embodiment, the cooling block 1
b is smaller than the cooling block 1a of the first embodiment by eight spacers, so that the weight of the magnetron device can be reduced.

[0025]

As described above, according to the magnetron device of the present invention, the fit between the outer diameter of the cylindrical anode body and the inner diameter of the cooling block is tightly fitted, and the cylindrical anode body is thermally shrunk or The cooling block is inserted into and fixed to the cylindrical anode body by using one of the thermal characteristics of the thermal expansion of the cooling block. Further, it is possible to improve the adhesion between the cooling block and the cylindrical anode body, and to provide a magnetron device having a high cooling effect on the cylindrical anode body.

[Brief description of the drawings]

FIG. 1 is a side view showing a magnetron device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a cooling block of the magnetron device.

FIG. 3 is a perspective view showing a state where a cooling block and a cylindrical anode body of the magnetron device are assembled.

FIG. 4 is a comparison diagram of the temperature of a cylindrical anode body during oscillation of the magnetron device of the present invention and a conventional magnetron device.

FIG. 5 is a diagram showing a temperature measurement position of the cylindrical anode body of the present invention.

FIG. 6 is a side view showing a magnetron device according to a second embodiment of the present invention.

FIG. 7 is a perspective view showing a cooling block of the magnetron device.

FIG. 8 is a side view of a conventional magnetron device.

FIG. 9 is a perspective view of a cooling block of a conventional magnetron device.

FIGS. 10A and 10B are diagrams showing a state in which a cylindrical anode body is inserted into a conventional cooling block.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1a Cooling block 2 Liquid flow path 3 Cylindrical anode body 4 Frame yoke 8 Spacer 10 Cylindrical hole 11 Screw for sealing

Claims (4)

[Claims] 1. A magnetron apparatus comprising: a cooling block formed to surround a cylindrical anode body and having a liquid flow passage therein; and a frame-shaped yoke connected to the cooling block. The fit between the outer diameter of the cooling block and the inner diameter of the cooling block is tightly fitted, and utilizing one of the thermal characteristics of thermally contracting the cylindrical anode body or thermally expanding the cooling block, The magnetron device, wherein the cooling block is inserted and fixed to the cylindrical anode body. 2. The magnetron device according to claim 1, wherein the cylindrical anode body and the cooling block are formed of materials having the same thermal expansion coefficient. 3. The magnetron device according to claim 2, wherein the material of the cylindrical anode body and the cooling block is copper or a copper alloy. 4. The magnetron device according to claim 1, wherein the cooling block is connected to the frame yoke via a spacer formed of a metal plate.