JPH0817354A - Anode structure of magnetron - Google Patents

Abstract

PURPOSE:To provide an accurate anode structure at low cost by curving one end of each vane along the internal wall of an anode cylinder and into a length equal to the interval between the adjoining vanes, and securing the ends to the internal wall of the anode cylinder, the other end of each vane extending toward the center of the anode cylinder. CONSTITUTION:A cathode is disposed at the center of an anode cylinder 11. A plurality (e.g. 10) of vanes 12 are provided in space inside the cylinder 11. The vanes 12 are arranged radially with one end secured to the internal wall of the cylinder 11 at equal intervals and the other end extending toward the center. The cylinder 11 side end of each vane 12 is curved along the internal wall of the cylinder 11 to constitute a curved portion 12a. The length of the curved portion 12a is equal to the interval between the adjoining vanes 12. The end of each vane 12 at the center of the cylinder 11 is also curved perpendicular to the surface of the vane 12. This curved portion 12b reduces the distance between the ends of the vanes 12, thereby increasing the capacity of a capacitor formed between the ends.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anode assembly of a magnetron used for a microwave oven or the like.

[0002]

2. Description of the Related Art A conventional magnetron used in a microwave oven or the like is composed of an anode structure which constitutes an oscillating portion, a cathode which is located at the center of the anode structure, and the like. The entire anode structure has a cylindrical shape, and a plurality of vanes are radially provided inside the anode structure. One end of the anode vane is fixed to the inner wall of the anode, and the other end extends toward the centrally located cathode to divide the space inside the anode into a plurality of spaces. The space divided by the vanes constitutes a cavity resonator, and
A magnetic field is applied to the cavity resonator from the outside to generate a high frequency signal. In addition, every other anode vane is electrically connected by a common strap ring.
For example, odd-numbered ones and even-numbered ones are electrically connected by a common strap ring.

[0003]

By the way, conventionally, the inner wall of the anode and the respective vanes are fixed to each other by brazing.
The brazing is performed by placing the anode and the vane in a hydrogen reducing atmosphere at a temperature of 900 ° C. or higher and heating for a certain period of time. When mass-producing the anode assembly, many anodes and vanes are simultaneously put into the furnace. Therefore, many jigs are required.

Further, the jig used for brazing the anode and the vane is required to have strict conditions such as a material having a lower coefficient of thermal expansion than copper, which is a material for the anode, and a material which is not brazed. Also, before brazing, accuracy is required to maintain the positional relationship between the anode and the vane in the correct state for brazing, and even after brazing, accuracy is required to obtain the dimensional accuracy required for the finished product. .

As described above, the brazing of the anode and the vane requires a complicated and highly accurate jig, and a large number of jigs are used in mass production. Therefore, the product cost increases.

For example, if the brazing time is 2 hours when producing with an index of 10 sec / pcs, 7
20 pcs parts are heated in the hydrogen furnace at the same time. Also,
If the jigs for assembling before being put into the hydrogen furnace and those that are brazed and collected are included, 1000 or more jigs are required. In addition, these jigs require regular dimensional control and the like, and maintenance work is not easy.

Further, the parts such as the anode and the vane to be brazed have complicated shapes, and it is necessary to support these parts with high accuracy. By the way, when the vane is held by a jig, the amount of thermal expansion due to heating when brazing is taken into account, so there is a gap at room temperature, which causes a problem in accuracy. If the gap is made small in order to eliminate such a problem and a jig having a gap having a difference in thermal expansion is used, it may be difficult to separate the component from the jig after brazing.
For this reason, a large gap is provided between the jig and the component, which deteriorates the accuracy of the anode structure.

The accuracy can be improved by using a movable jig. However, in the movable jig, oil is required to lubricate the movable parts. However, there are few materials that are inert and can maintain lubrication even at high temperatures. In addition, the drive mechanism that operates at high temperature is expensive. Therefore, the use of the movable jig is not practical in terms of cost.

The present invention solves the above-mentioned drawbacks, and an object of the present invention is to provide a low-cost and accurate magnetron anode assembly.

[0010]

According to the present invention, one end is fixed to an inner wall of an anode cylinder, and the other end has a plurality of spaces surrounded by the plurality of vanes extending toward the center of the anode cylinder. In the magnet assembly of the anode structure, the tip of the vane on the side fixed to the inner wall of the anode cylinder is bent along the inner wall of the anode cylinder, and is bent to a length equal to the distance between adjacent vanes. , Is fixed to the inner wall of the anode cylinder by using the bent portion at the tip of the vane.

[0011]

According to the above-mentioned structure, the tip of the vane on the side fixed to the inner wall of the anode is bent so that the surface of the vane is along the inner wall of the anode cylinder and the length is equal to the interval between the adjacent vanes. There is. Then, it is fixed to the inner wall of the anode by using the bent portion at the tip of the vane. To fix the bent part at the tip of the vane to the inner wall of the anode, spot welding, projection welding, seam welding, and other parts that are to be joined together are stacked, and lap resistance welding in which a current is applied to that part, or mechanical methods are used. Used. Therefore, since it is not put in a high temperature atmosphere for a certain period of time, it is possible to assemble using a highly accurate movable jig. Further, since the movable jig can be held in close contact with the component, it is possible to obtain an anode assembly with high accuracy and less variation. Since the bent portion at the tip of the vane and the inner wall of the anode are fixed to each other by spot welding or the like, a jig having a complicated shape such as brazing is not required. As a result, the cost of manufacturing equipment is reduced, and an inexpensive and high-quality magnetron can be realized.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

Reference numeral 11 is an anode cylinder, and a cathode (not shown) is arranged at the center thereof. A plurality of vanes 12, for example, 10 vanes 12 are provided in the inner space of the anode cylinder 11.
One end of each vane 12 is fixed to the inner wall of the anode cylinder 11 at equal intervals, and the other end of each vane 12 is arranged radially toward the center. The tip of each vane 12, for example, the anode cylinder 11 side, is bent substantially vertically along the inner wall of the anode cylinder 11 to form a bent portion 12a.
The length of the bent portion 12a is set to be equal to the interval between the adjacent vanes 12. Therefore, the bent portion 1
By arranging the adjacent vanes 12 so as to be in contact with the tip of 2a, the interval between the vanes 12 can be set correctly. Also,
The other tip of the vane 12, that is, the center side of the anode cylinder 11 is also bent perpendicularly to the surface of the vane 12, and the bent portion 12
b is formed. This center side bent portion 12b
Reduces the distance between the tips of the vanes 12 and increases the capacitance of the capacitor formed between the tips of the vanes 12.

FIG. 2 is a view seen from the line AA of FIG. 1 in the direction of the arrow, and the portions corresponding to FIG. 1 are designated by the same reference numerals. Strap grooves 13a and 13b are provided at the upper and lower ends inside each vane 12. Two strap rings 14a, 14b and 15a, 15b having different diameters are arranged in the strap grooves 13a, 13b. Strap rings 14a, 14b, 1
5a and 15b connect every other one of the vanes 12. For example, if the left side is an odd-numbered vane 121 and the right side is an even-numbered vane 122, in the upper strap groove 13a, the strap ring 14b connects the odd-numbered vanes 121 and the strap ring 14a is an even-numbered vane 121. The vanes 122 are connected to each other. Also,
In the lower strap groove 13b, the strap ring 1
5a connects the odd-numbered vanes 121, and the strap ring 15b connects the even-numbered vanes 12. In addition, the bent portion 12a of the vane 12 and the anode cylinder 1
1 is fixed by spot welding, for example.

It takes 30 seconds to weld such parts.
If it takes / pcs, it takes 3 to hold and weld parts during assembly.
It can be produced on a stand and can be worked with few jigs.

The strap ring and the vane are joined by brazing, for example. In this case, since the vane has a notch, it is possible to easily and accurately hold the vane by using the notch. Therefore, a jig having a simple structure can be used for brazing the strap ring and the vane, and dimensional control is not required.

According to the above structure, the interval between the vanes is
Since the length of the bent portion of the vane determines the assembly accuracy. Therefore, the jig used for welding does not require so high accuracy.

In the above embodiment, the vane and the anode are fixed by spot welding. However, as with spot welding, such as projection welding and seam welding, parts that are joined to each other are overlapped, and lap resistance welding in which a current is passed through the parts can be used. FIG. 3 is an example of projection welding, and portions corresponding to those in FIG. 2 are denoted by the same reference numerals, and duplicated description will be omitted. A part of the inner surface of the anode cylinder 11 is embossed in advance, and the embossed portion 31 is used for projection welding with the vane 12.

Further, as shown in FIG. 4, an embossing 41 is provided on the inner surface of the anode cylinder 11, a hole is formed in the bent portion of the vane 12 at a position corresponding to the embossing 41, and the embossing 41 is fitted into the hole. Then, the tip of the embossing 41 may be crushed and mechanically fixed. In FIG. 4 as well, portions corresponding to those in FIG. 2 are denoted by the same reference numerals, and duplicate description will be omitted.

According to the above-described embodiment, when fixing the vane and the anode, a jig having a high precision and a complicated shape such as brazing is not required, and the equipment cost and the cost can be reduced. . Further, since the assembly is performed at room temperature, a highly accurate movable jig can be used, and a highly accurate anode assembly can be realized.

[0021]

According to the present invention, it is possible to realize an accurate magnetron anode assembly at low cost.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

FIG. 2 is a view for explaining an embodiment of the present invention and is a sectional view of FIG.

FIG. 3 is a diagram illustrating another embodiment of the present invention.

FIG. 4 is a diagram illustrating another embodiment of the present invention.

[Explanation of symbols]

 11 ... Anode cylinder 12 ... Vane 12a, 12b ... Bent part

Claims (1)

[Claims] 1. A magnetron anode, one end of which is fixed to an inner wall of an anode cylinder, and the other end of which extends in the direction of the center of the anode cylinder to divide the space surrounded by the anode cylinder into a plurality of spaces. In the structure, the tip of the vane on the side fixed to the inner wall of the anode cylinder is along the inner wall of the anode cylinder, and is bent to a length equal to the distance between adjacent vanes, and the bent portion of the vane tip is formed. An anode assembly for a magnetron, characterized in that it is fixed to the inner wall of the anode cylinder.