JPS6233696B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for removing foreign matter adhering to an electrode assembly used in an electron tube or the like.

In general, electrode assembly structures (hereinafter referred to as mounts) used in electron tubes, etc., generate splashes, that is, small metal scraps generated during welding work, due to electrode welding work performed when assembling the mounts, etc. When handling the mount when assembling the mount, foreign matter such as dirt gets on the mount, and there is also floating lint, that is, fine debris such as human hair, nylon, cotton, and synthetic fibers, in the work room, and these foreign matter adhere to the mount. It turns out.

In an electron tube in which a mount with foreign matter adhered to it is inserted into, for example, an envelope of the electron tube, hermetically sealed, and the inside of the tube is evacuated, the following problems occur. In other words, it is subjected to thermal forces due to heat treatment during evacuation during the manufacturing process of electron tubes, and mechanical shocks due to handling during successive processes.
The splash is liberated, while the lint is also carbonized during the heat treatment to become an electrical conductor and adhere. Some of these splashes and carbonized lint adhere to the electrodes, which causes problems such as deterioration of withstand voltage and short circuit between electrodes during operation of the electron tube.

Various measures have been taken to prevent such problems from occurring. For example, welding splash has been improved to some extent by considering the selection of electrode materials, welding equipment, and welding conditions, but it is difficult to perform welding completely without splash. In addition, when it comes to foreign substances such as lint, it is unavoidable that the lint will float in the air, so the mount should be assembled in a dust-proof room, and workers should wear dust-proof clothing in front of the clean bench. Even if you decide to work with
Lint will decrease, but will not disappear completely. On the other hand, when the mount is assembled, a member made of insulating material is used to fix it in a predetermined position inside the pipe, and the material is glass, mica, ceramics, etc., and these are all electrically high resistance materials. Because of this, it is easy to be charged, and since the working room where the mount has just been assembled is not only lint-free, but the humidity in the room is suppressed, it becomes even easier to be charged, and lint adheres to the members made of these insulating materials. It is something to do. Also, it is possible for metal to adhere if it is not completely grounded.

Even if air is jetted to remove foreign matter such as lint that has adhered in this manner, it is difficult to remove the foreign matter that is electrically charged with static electricity.

The present invention has been made in view of the above points, and an object of the present invention is to provide an improved processing method for effectively removing electrically attached foreign substances from a mount. In other words, when blowing gas to remove foreign matter adhering to a mount, etc., this gas is passed through an electrostatic neutralization device or the like to turn it into a gas with a positive or negative charge, that is, an ionized gas.
This is sprayed to neutralize static electricity and remove foreign matter adhering to insulating members, electrode members, etc., which could not be removed conventionally.

In this way, dry air or dry nitrogen is suitable as the gas used for removing foreign matter. The removal method will be explained below. Thoroughly remove dust and send dry air to the static neutralizer. This device has a structure similar to a spray gun, and by passing dry air through this device, it becomes ionized air, which is sent to the assembled mount from the outlet of a pipe installed near the mount workbench. Spray. By being blown with this air, the static electricity of foreign objects such as lint, which are charged with static electricity, is neutralized and becomes uncharged, and the adhesion of foreign objects, such as those attached to insulating materials, is weakened. Can be easily removed.

In this way, in the past, it was difficult to remove foreign objects that were electrostatically charged due to their strong adhesion, but with the method of the present invention, they can now be removed extremely easily. ,
It can be made into a state where almost no adhesion occurs.

In addition to simply blowing ionized air, applying mechanical vibration to the mount to which foreign matter has adhered will make it easier to remove not only the lint but also the adhered splash. For example, applying high frequency vibrations of about 1KHz is extremely effective. Furthermore, if the sonic vibration is superimposed on the gas to be blown instead of the foreign matter adhering body, and this is blown, the effect on the release of the foreign matter will be even greater.

When removing foreign substances by spraying the gas of the present invention with the above-mentioned vibrations applied, for example, in the case of an electron gun for a picture tube as an electron tube component, spraying is performed for about 2 minutes to achieve extremely high efficiency. Foreign matter can be removed well, and compared to conventional products, the amount of foreign matter less than 10 μm attached is less than 1/50, so it can be said that there is almost no foreign matter attached.

As described above, the method of the present invention is extremely effective as a so-called dust removal method for mounts installed in electron tubes, etc., and is particularly effective in removing foreign matter from electron gun structures for color picture tubes that operate at high voltage as tubes. This is a processing method.

Claims (1)

[Claims] 1. An electrode assembly for an electron tube, characterized in that when removing foreign matter adhering to the assembly when forming an electrode for an electron tube, ionized gas is blown onto the electrode assembly to remove the foreign matter. processing method.