JPS6041638Y2 - Magnetron cathode structure - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a magnetron cathode structure.

FIG. 1 shows a conventional structure of this kind, in which 1 is a cathode filament, 2 and 3 are upper and lower end butts located near the upper and lower ends of the filament, respectively, and 4 is a first cathode lead that supports the upper end butt 2. , 5 is the lower end butt 3
The second cathode lead supports the second cathode lead.

Although the cathode filament 1 has a coil shape, only a cross section is shown in the figure.

The upper end of the cathode filament 1 is fixed to a fixed metal 6 inserted into the upper end of the first cathode lead, and the lower end is fixed to the vertical cylinder part 7 of the lower end butt 3. Therefore, the upper end butt 2 Although the shape can be formed by pressing, the lower end butt 3 must be formed by cutting.

However, the end butt is usually made of expensive and hard molybdenum, and therefore, when cutting it as described above, there is a large loss of material and the work is not easy.

The other conventional structure shown in Figure 2 is an improvement on this point.
Together with the upper end butt 2, the lower end butt 3 is formed into a stepped cup shape, and the end of the cathode filament 1 is fixed to the bottom of the lower end butt 3, whereby the lower end butt 3 can also be press-formed without material loss and with good workability. It makes it possible to form.

However, in the structure shown in FIG. 2, the lower end of the cathode filament 1 is directly bonded to the lower end butt 3 as in FIG. It is necessary to provide an inner vertical wall 8 that has a large contact area with the lower end.

Such complex shapes make hard molybdenum stamping jigs more expensive.

The present invention has been made in view of the above points, and as shown in the embodiment shown in FIG. It is characterized in that the lower end of 1 is fixed.

The shape of the second cathode lead 5 is preferably cylindrical as shown in the figure to increase the contact area between the lead and the lower end of the cathode filament 1.

Note that the second cathode lead and the lower end of the filament are fixed by ordinary brazing.

Since the cathode filament 1 is not directly fixed to the lower end butt 3, the end hat can be formed by pressing, and its shape can be made very simple and easy to press.

The lower end knot 3 can be fixed to the second cathode lead 5 by engagement as shown in the figure.

FIG. 4 shows the details of the assembly. First, the cylindrical second cathode lead 5 is formed by rolling a molybdenum thin plate, and the dish-shaped lower entomohet 3 is formed by pressing a molybdenum thin plate.

At this time, the second cathode lead 5 has an elongated hole 9°9 along the circumferential direction at opposite positions on the cylindrical side surface, and the lower end butt 3 has a pair of straight edges opposite to each other at the bottom of the second cathode lead 5. 10
A non-circular hole 11 having a diameter of 100 mm is being used, respectively.

Incidentally, these elongated holes and non-circular holes are provided in the preparation process of the molybdenum thin plate before the above-mentioned roll processing and press processing, respectively.

The cylindrical shape of the second cathode lead 5 is not completely closed and has a slit 12. Therefore, while the cylinder is slightly compressed in the inner diameter direction, its upper end is inserted through the non-circular hole 11 of the lower end butt 3. When the linear edge 10 of the hole and the elongated hole 9 of the second cathode lead 5 are released, the elongated hole 9 becomes the linear edge 10 of the non-circular hole 11. The fitted lower end butt 3 is engaged with and held by the second cathode lead 5.

Thus, according to the present invention, the cathode lead supporting the lower end butt is made to protrude from the lower end butt, and the lower end of the cathode filament is fixed to the cathode lead, so that the lower end butt can be connected without material loss and with ease of work. It can be formed by press working with good quality, and since the butt shape can be simple, the shape of the pressing jig can also be simple.

Further, the cylindrical cathode lead can be formed by a very simple process of punching a thin plate and rolling.

[Brief explanation of drawings]

Fig. 1 is a side view showing a conventional example in half cross section, Fig. 2 is a sectional view showing another conventional example, Fig. 3 is a side view showing the embodiment of the present invention in half cross section, and Fig. 4 is the same. FIG. 2 is an exploded perspective view of essential parts of the embodiment. 1... Cathode filament, 2... Upper end butt, 3... Lower end butt, 4,
5...First and second cathode leads.

Claims (1)

[Scope of utility model registration request] It includes a cathode filament, upper and lower end butts located near the upper and lower ends of the filament, and first and second cathode leads that support both end butts, and the second cathode lead is compressed so that its diameter is reduced. The lower end butt has a substantially cylindrical shape with a slit in the axial direction so that it can be made smaller, and a long hole along the circumferential direction at opposite positions on the side of the lower end butt. a non-circular hole having a pair of straight edges, the straight edges being fitted into the elongated hole to cause the upper end of the second cathode lead to protrude upwardly from the lower end butt; A magnetron cathode structure characterized in that the lower end of the filament is fixed to the upper end.