JPS632226A - Magnetron for electron range - Google Patents

Abstract

PURPOSE:To improve a utilization factor of a yoke material for cost reduction by bending a piece of plate into a rectangular form in making butt joint parts position in a place where the tube axis passes through. CONSTITUTION:A ferromagnetic yoke 10 is arranged so as to surround an oscillating part body 1, permanent magnets 4 and 5, and a radiator 6. The yoke 10 is made of a piece of plate bent into a rectangular form in making butt joint part position in a place where the tube axis passes through, and it is fixed by calking. In this case, a pair of mounting plates 11 and 12 for mounting the tube, for example, on a waveguide when it is used are provided near a circular permanent magnet 4. The mounting plates 11 and 12 are provided with punched engaging holes 13 to 16 and 17 to 20 respectively. on the other hand, the yoke is saliently provided with cut-up pieces 21 to 24 and 25 to 28 corresponding to the engaging holes 13 to 16 and 17 to 20 of the mounting plates 11 and 12 while the cut-up pieces 21-24 and 25-28 are calked in the engaging holes 13 to 16 and 17 to 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a magnetron for a microwave oven, and particularly to an improvement of the yoke thereof.

(Prior art) Conventionally, magnetrons for microwave ovens are shown in Figs. 4(a) and (b).
), an output section 2 and an input section (not visible in the figure because they are covered with a shield case 3) are provided on both sides of the generator main body 1, respectively. An annular permanent magnet 4.5 is fitted around the output section 2 and the input section, and is stacked on the oscillating section main body 1. Furthermore, a radiator 6 consisting of a plurality of fins is provided on the outer periphery of the oscillating unit main body 1. A ferromagnetic yoke is arranged to surround the generator body 1, permanent magnet 4.5, and radiator 6, and as is clear from the figure, this yoke is connected to a flat upper yoke 7. It consists of a U-shaped lower yoke 8, and is tightened and fixed by screws 9.

(Problem to be Solved by the Invention) However, in the conventional magnetron as described above, it is difficult to completely connect the upper yoke 7 and the lower yoke 8 magnetically. Therefore, a large overlapping area was required. Moreover, when the upper yoke 7 and the lower yoke 8 are expanded, they are shown in FIGS. 5(a) and 5(b). The lower yoke 8 has a simple outer shape and has good material utilization, but the upper yoke No. 7 has a complicated external shape, so there is a lot of wasted material.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetron for a microwave oven that improves the utilization rate of yoke materials and reduces costs.

[Structure of the Invention] (Means for Solving the Problems) In the present invention, the yoke is formed by bending a single plate into an opening shape, and the butt-connected portions at both ends are located approximately on a plane passing through the pipe axis. This is a magnetron for microwave ovens.

(Function) In this invention, the yoke is bent from a single plate into a mouth shape, and the butt-connected portions at both ends are located approximately on a plane passing through the tube axis, so the outer shape is simple and the material is No waste,
Cost reduction can be achieved. Furthermore, even if a gap occurs between the butt-connected portions at both ends, there is no magnetic loss.

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

The magnetron for microwave oven according to this invention is shown in FIG.
It is constructed as shown in a) and (b), and the same parts as in the conventional example are given the same reference numerals.

That is, an output section 2 and an input section (not visible in the figure because they are covered with a shield case 3) are provided protruding from both sides of the oscillating section main body 1, respectively. An annular permanent magnet 4.5 is fitted around the output section 2 and the input section, and is stacked on the oscillating section main body 1.

Furthermore, a radiator 6 consisting of a plurality of fins is provided on the outer periphery of the oscillating unit main body 1. A ferromagnetic yoke 1o is arranged so as to surround the oscillating unit body 1, the permanent magnet 4.5, and the radiator 6.
0 is different from the conventional one, as shown in Fig. 2(b), it is bent from a single plate into a mouth shape, and the butt-connected portions at both ends are located approximately on the plane passing through the pipe axis, and are fixed by caulking. .

In this case, in the vicinity of the annular permanent magnet 4, a pair of mounting plates 11 and 12 are provided for mounting, for example, to a waveguide during use, and as shown in FIG.
．． 12 are provided with locking holes 13, 14, 15, 16 and 17, 18, 19, 20, respectively.

On the other hand, as shown in FIG.
Corresponding to 7.18.19.20, cut and raised pieces 21.22
．． 23.24 and 25.26.27.28 are provided protrudingly. The cut and raised pieces 21.22.23.24 and 25.26.27.28 are connected to the locking holes 13.14.15.
16 and 17.18.19.20 are caulked.

The mounting plates 11 and 12 play the role of fixing the yoke 10, maintaining the flatness of the two surfaces of the output section, and connecting the magnetron and the waveguide.

Also, in Figure 1, 29 is a gasket, 30°31.3
2.33 is installed with screws.

(Modification) FIG. 3 shows a modification of the present invention, which provides the same effects as the above embodiment.

That is, in the embodiment described above, the butt-connected portions at both ends are fixed by caulking, but in this modification, the butt-connected portions at both ends of the yoke 34 at point A are joined and fixed by welding.

In addition, in this modification, the mounting as in the above embodiment is performed on the plate 11.
．． 12 is not used, but mounting pieces 35.
36, 37, and 38 are attached to a waveguide or the like when in use.

[Effects of the Invention] According to the present invention, the yoke is bent from a single plate into a mouth shape, and the butt-connected portions at both ends are positioned approximately on a plane passing through the pipe axis and fixed by caulking or welding. The outer shape is simple, there is less waste of material, and costs can be reduced. That is, considering that the area required to manufacture a yoke is the area of a rectangle with the maximum length of each side, the conventional example and the present invention are compared as follows.

Conventional example: 70x182.6+128x90.8 -24404.4 shoes This invention: 70x253.2+44x50x2 pieces -22124M2 In this way, about 10% of the material can be saved. Furthermore, in the case of welding as in the modified example, material can be saved even more.

Furthermore, since the magnetic flux passing through the two-end butt connection is theoretically zero, almost no magnetic loss occurs even if a gap is created in the two-end butt connection.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are a plan view and a front view showing a magnetron for a microwave oven according to an embodiment of the present invention, and FIG.
a) and (b) are a plan view and a developed view showing the mounting plate and yoke used in the microwave oven magnetron of the present invention, FIG. 3 is a perspective view showing a modification of the present invention, and FIG. 4 (a>, (b
) is conventional. Top view and front view showing a magnetron for microwave oven, No. 5
Figures (a) and (b) are a plan view and a developed view showing a yoke used in a conventional microwave oven magnetron. DESCRIPTION OF SYMBOLS 1... Generator main body, 2... Output part, 3... Shield box, 4.5... Permanent magnet, 6...
Radiator, 10...Yoke, 11.12...
mounting plate.

Claims (1)

[Scope of Claims] A magnetron for a microwave oven in which annular permanent magnets are coaxially stacked on an oscillating unit body, and a yoke is disposed to surround the oscillating unit body and the permanent magnets, the yoke comprising: A magnetron for a microwave oven is formed by bending a single plate into a rectangular shape, and having both ends butt-connected portions located approximately on a plane passing through the tube axis.