JPS60112241A - Vacuum discharge tube and its manufacturing method - Google Patents

Abstract

PURPOSE:To increase sealing reliability and productivity by airtightly brazing and sealing an assembly frame body consisting of a vacuum container component members and an internal component members in a hydrogen furnace and heat-treating a sealed frame body in an atmospheric furnace in which the partial pressure of hydrogen is lower than 1X10<-4>Torr. CONSTITUTION:An insulating cylinder 1 is made of ceramics and flanges 2a and 2b are made of an iron and nickel alloy plate and end plates 3a and 3b are made of stainless steel. Metal bellows 4a and 4b contain palladium and the internal surface of a vacuum container other than the brazing section of electrodes 6a and 6b and electrode sections 7a and 7b is made of titanium copper (Ti2Cu). Besides, a solid getter 8 contain zirconium and the surface of a shield 9 that is not exposed to discharge arc is made of a titanium alloy and silver solder and such are used as soldering material. The above component members are assembled by a jig and are airtightly brazed in a hydrogen furnace. Then a sealed frame body is heat-treated in a non-hydrogen gas atmospheric furnace in which the hydrogen gas pressure is less than 1X10<-4>Torr. As a result, sealing is performed with high reliability and a vacuum discharge tube can be manufactured in a short period of time with high efficiency.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to the material composition of the vacuum vessel constituent members and the vacuum internal constituent members of a vacuum discharge tube, and the assembled structure thereof is hermetically brazed and brazed in a hydrogen furnace. The present invention relates to a vacuum release tube in which residual hydrogen in a vacuum container is evacuated by heating the sealed structure in an atmosphere or an atmosphere with a low hydrogen partial pressure after sealing, and a method for manufacturing the same.

[Prior art]

A conventional vacuum discharge-lf is shown in FIG.

In Figure 1. illY′i ceramic insulation cylinder,
(2a), (21)) n Iron-nickel alloy plate flange, (3a).

(3b) ld is a stainless steel end plate, (4) is a stainless steel bellows, and +51 is a copper exhaust pipe, which constitute a vacuum vessel. (6al, (6b) is an electrode,
j7a) and (7b) are electrode rods, which are largely made of copper alloy or copper. (8) is a solid getter, and (9) is a shield, each made of titanium.

Made of stainless steel. FIG. 1 is a diagram showing the configuration of a so-called vacuum switch tube, and vacuum fuses, vacuum vents with triggers, vacuum arcs, vacuum capacitors, etc. have the same configuration. Each of the above parts from fl+ to ('+b) is assembled by brazing, twisting, or bathing the respective joint surfaces.

In particular, the joint surfaces between each component of the vacuum container are hermetically sealed under strict quality control. After sealing this vacuum discharge tube, it is degassed with a high-temperature cylinder, and finally the pressure is removed between the two to seal it. ), is one of the important airtight seals.

In the conventional vacuum discharge tube, as shown in FIG. 1, the assembly consists of at least three parts. That is,
Upper part of figure bar [3a), i51, (6a), ('7
(1) and (2) in the center of the figure.
a), (3a), and (1m below in the figure).
3b),! 4t, (61)), (7bl) are each divided into assembled structures, which are generally brazed together in a vacuum furnace or hydrogen furnace. Each brazing section undergoes extensive quality inspection before being assembled into a subassembly structure. Completion Then, the assembled structure of the above three parts consists of (28) and (3a), and (2b) and (3b).
) are usually welded and hermetically fused together to complete the vacuum discharge g assembly. At this stage, if necessary, the exhaust pipe (5) is connected to a helium leakage detector, and the hermetic seal is inspected for vacuum leakage using helium gas, and the entire assembly is completed.

After that, the entire three-dimensional structure shown in Fig. 1 was connected to a vacuum evacuation device via an exhaust pipe (5), and heated to a madder temperature.
Evacuate the inside of the empty discharge tube to a high degree of vacuum. After heating and evacuation are completed, the part (5a) of the exhaust pipe (5) is completely cold welded and the vacuum discharge tube is sealed to complete the fabrication.

This ear vacuum discharge tube is a product that is required to maintain the crystal vacuum fart for many years over 20 to 30 years, and is also required to be reliable in operation. For example, when several tens of thousands of tubes are used in the field, the degree of vacuum is l
10” Torr - The ratio of the area that deteriorates is 1/
It is required that the applicant is no more than 20 years old.

In order to meet these requirements, the slow leak rate of the vacuum vessel force is l x 1O-12Torr-t/θθ
Since it is necessary to keep the temperature below C, vacuum container components,
In particular, strict quality control must be carried out in the process of airtight connection between the seeds.

Conventional vacuum discharge tubes were constructed as described above, so
Since the end of the exhaust tip pipe (5a) protrudes, there remains a risk that the tip pipe (5a) may hit a mounting tool or the like during product handling, resulting in a slow vacuum leak.

In addition, as mentioned above, conventional vacuum discharge tubes require a large number of manufacturing and inspection processes and require a wide variety of expensive equipment, so it is important to manufacture them economically. In order to improve the above-mentioned drawbacks of the vacuum discharge tube, the exhaust system (51) is removed, and the parts are brazed and assembled in a hydrogen furnace, and the entire assembly is assembled in a vacuum furnace while the , and finally (2a), (3a) or (2D), (3
Is it manufactured by soldering and sealing both or one of b)?
A method to complete the process has been suggested. Furthermore, a method has also been proposed in which (1) the above (2) and (2) are carried out simultaneously in a vacuum furnace by performing evacuation, brazing, and gold all at once. However, brazing in a vacuum furnace has a weak reducing effect and there is no heat transfer due to convection of the gas in the casing, so the temperature of the vacuum discharge tube to be brazed is reduced. ! r
As a result of the uneven temperature distribution in the parts, the axial properties of the wax parts are clearly inferior to those in the hydrogen furnace, and the production yield is therefore poor.
The vacuum degree of the finished product had a drawback that it could not be said to be sufficient.

[Summary of the invention]

This invention was made to eliminate the above-mentioned drawbacks of the conventional vacuum discharge tube. After removing all parts and brazing and sealing all parts together in a hydrogen furnace, the heating element is heated in an atmosphere furnace with extremely low hydrogen partial pressure or in an atmospheric furnace, and then cooled into a vacuum discharge tube. The purpose of the present invention is to provide a reliable commercial vacuum discharge-tt' that is manufactured by exhausting and removing trapped hydrogen gas.

The point of view of this invention is to make specific members of the vacuum vessel constituent members of a vacuum discharge tube have high hydrogen gas permeability at a relatively high surface temperature, and which are comparable to ordinary vacuum vessel constituent members at relatively low temperatures. The point is that it is made of a material whose hydrogen gas permeability is sufficiently low so that there is no change in hydrogen gas permeability. We decided to shorten the number of manufacturing steps and provide an economically superior vacuum discharge tube by using the hydrogen furnace brazing method, which has much higher brazing reliability and the same productivity as the vacuum furnace brazing method. It is something to do.

[Embodiments of the invention]

An embodiment of the invention will be described below with reference to FIG. In FIG. 2, the exhaust pipe has been removed, and the other parts are the same as in FIG. 1.

In one embodiment of the invention, the metal bellows (5a
lt (”b), and palladium Pdi
It is an alloy containing In addition, the electrodes (6aL t6b) and the brazing of the electrode rods (7a) and ('7b) should be made with copper titanide Ti2C at least on the surface of the inner 11a of the vacuum vessel of the vacuum discharge tube, except for the electrodes (7a) and ('7b). It consists of u. Furthermore, a solid getter (
8) is an alloy containing zirconium Zr f, and at least the surface of the shield (9) that is not exposed to discharge arc +tN
is made of titanium T1 alloy. Although not shown in the drawings, the solder metal is a conventional solder, gold solder, or steel manganese solder.

All the components shown in Figure 2 are assembled together with the above-mentioned brazing filler metal in the required jig, and then pushed into the hydrogen furnace.The residual gas in the vacuum discharge tube is expelled by heat and swelling. is,
Instead, hydrogen scum is filled into the vacuum tube. When the temperature rises further, some of the oxide film on the internal surface of the vacuum discharge tube is removed by the strong reducing action of hydrogen gas, and the cleaning of the internal and external surfaces of the vacuum discharge tube is completed.Next. , the brazing material between each member of the vacuum discharge tube begins to melt in the bath.

In this case, the point that is significantly different from brazing in a vacuum furnace is ■
The long surfaces of the bonded metals are subjected to a strong fx reduction and cleaning effect due to the high temperature hydrogen gas. - Due to the convection effect of high-temperature hydrogen gas, the TMW of each part of the metal surface to be bonded becomes extremely uniform. Therefore, the brazing is free from pinholes and bubbles, as is the case with vacuum furnace brazing.

Also, the temperature rises slowly in the parts that are geometrically affected by the radiant light of the vacuum furnace heat source, and conversely, the temperature rises faster in the parts that are directly exposed to the direct radiation. In particular, the drawbacks of the vacuum brazing furnace, such as the large temperature difference between the inside and outside of the brazing furnace, do not occur. This step of the present invention is
This corresponds to the evacuation, brazing, and sealing steps in the conventional bulk brazing exhaust method in a vacuum furnace, but the embodiment of the present invention has the characteristic that sealing can be completed in an extremely short time. .

Next, when the brazing of the parts is completed in the hydrogen furnace, the vacuum discharge tube is cooled together with the necessary jigs in a low-temperature hydrogen atmosphere, and then, even if the hydrogen gas pressure is high,
It is transferred into a furnace at 0' TOrr or less.

The vacuum discharge tube is subsequently heated in this non-hydrogen gas furnace for the required temperature and time. This step corresponds to an evacuation step using a conventional vacuum evacuation device. That is, immediately after sealing is completed, the inside of the vacuum tube is filled with hydrogen gas at a pressure of 1 atm, but after sealing is completed, this hydrogen gas is transferred to the electrode (6).
a), f6b) + '41 pole bar (7a).

(Th) is gradually adsorbed on the surfaces of the solid getter (8) and the shield (9), and at the same time, in a non-hydrogen gas atmosphere furnace, a bellows consisting of a thin plate is used to remove the gas from inside the vacuum vessel. As a result of hydrogen gas permeating to the outside,
The hydrogen gas pressure inside the vacuum container is reduced to an equilibrium pressure of l x 10' Torr or less in this embodiment. In other words, it can be exhausted.

In the VCL vacuum discharge tube of this invention, the surface material of the constituent members inside the vacuum vessel is made of hydrogen storage materials such as titanized steel, zirconium alloy, and titanium, and the thin plate bellows material is made of an alloy containing palladium. Due to the synergistic effect of this and the subsequent heat treatment in a non-hydrogen atmosphere furnace after soldering and sealing in a hydrogen furnace, the inside of the discharge tube can be heated to about IX at a high temperature of several hundred degrees Celsius. 10-
' This makes it possible to trap and evacuate at a high vacuum level below Torr.

This non-hydrogen atmosphere furnace may be either a pure metal furnace or an argon furnace, and there is no practical problem even if it is a simple atmospheric furnace. After complete heating in the non-hydrogen atmosphere furnace,
When a vacuum discharge tube is taken out into the atmosphere at room temperature, the pressure inside the tube will definitely reach a high pressure of less than 1×1 5 Torr.

As mentioned above, in the embodiment shown in Fig. 2, the configuration diagram of the port switch g was modified and used, but the vacuum discharge tube according to the present invention is equipped with a Makabe capacitor, a vacuum fuse, a port arrester, and a vacuum trigger in addition to the vacuum switch tube. ) f! i ton'g.

The same effect is also achieved in vacuum tubes such as hydrogen thyratrons and hydrogen-filled tubes.

In addition, titanium,
In the case of titanized steel and zirconium alloy, the case has been described in which a thin plate bellows containing palladium is used as a component of the vacuum vessel, but the present invention is not limited to the above-mentioned materials and components, and can be used. Depending on the working temperature If- of the brazing filler metal, it is possible to use hydrogen storage alloys other than those mentioned above, and the same effect can be obtained by using a thin plate-shaped vacuum vessel component such as a diaphragm instead of the bellows.

Furthermore, the effect of the present invention can be achieved not only when the surface material of the internal component of the vacuum container is a thorny surface, but also when the base material of the component is the material according to the present invention and the surface is plated with another material. It's not something that will hurt you.

〔Effect of the invention〕

Based on the above method (7), the material inside the vacuum vessel and the *Ift of the Shinya device, part of all of the material, the hydrogen absorbing metal and the hydrogen permeable material, are constructed. Brazing Iig: Brazing is sealed in a highly flexible hydrogen furnace, and can be continuously heated and exhausted in a non-hydrogen atmosphere furnace. Vacuum discharge with excellent airtight reliability. It became possible to manufacture.

As a result, conventional methods are extremely expensive, complicated to handle, require a long time to reach a high vacuum, and furthermore, the geometrical "shadow" of the heater tends to result in uneven temperature distribution. Vacuum brazing exhaust installation 1ff, which requires a long cooling time even after brazing and sealing, is no longer necessary, and vacuum 7i! 2 City pipes can now be manufactured at low cost.

[Brief explanation of the drawing]

Figure 1 shows the structure of a conventional vacuum discharge tube, and Figure 2 is an example of this invention. This is a diagram of the boss. (1)...Insulating cylinder, (2a)...Flange, (2b
)...Flange, (A)...End plate, (3b)...
End plate, 14)... Bellows, (4a)... Bellows, (51... Exhaust pipe, (6a)... Electrode, (6b)
... electrode, (7a) ... electrode rod, (7b) ... electrode rod, (8) ... solid targetera), +91 ... shield. In each figure, the same reference numerals indicate the same or equivalent parts.
Masuo Oiwa Figure 1 Figure 2 Continuation of Page 1 [Phase] Inventor Osamu Uchiyama 8-1-1 Uchimachi, Tsukaguchi Hon Seisakusho, Amagasaki City Mitsubishi Electric Co., Ltd. Communication equipment procedural amendment (voluntary) Showa 5 list 1 13th January) Commissioner of the Japan Patent Office 1, Indication of the case: Japanese Patent Application No. 58-218201 2, Name of the invention Vacuum discharge tube and its manufacturing method 3, Person making the amendment Representative Hitoshi Katayama Department 4, Attorney 5 Subject of amendment (1) Column 6 of detailed explanation of the invention in the specification, contents of amendment

Claims (1)

[Claims] +l) Brazing and sealing temperature processing of vacuum vessel constituent members in a hydrogen furnace is also a vacuum vessel constituent member capable of discharging residual hydrogen gas in the vacuum vessel to the outside of the Makabe vessel at low exhaust temperature. and an internal structural member of the vacuum container that absorbs into the material, and does not include an exhaust pipe, and is characterized in that the residual hydrogen gas pressure in the vacuum container at a previous temperature lower than the exhaust temperature is 1 oOTor or less. vacuum discharge tube. (2) The vacuum discharge tube described in the patent item, wherein a part of the vacuum vessel constituent member contains palladium. [31 mJ] The vacuum discharge tube according to claim 1, wherein a part of the internal component of the vacuum vessel contains at least one of titanium, copper titanide, and zirconium. (4) The vacuum discharge tube according to claim 1, wherein the residual hydrogen gas pressure in the vacuum vessel at the previous temperature is less than or equal to l x lcr'Torr. (51 The first step of hermetically brazing and sealing the assembled structure of the vacuum vessel constituent members and the internal constituent members in a hydrogen furnace, and the sealing structure is heated at a hydrogen gas pressure of l x 10-'Torr or more. and a second step of heat treatment in a non-hydrogen gas atmosphere furnace.