JPS5929360B2 - Flexible long carbon electrode for gouging - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flexible long carbon electrode for gouging, and more specifically to a round rod or string made of carbon fiber as a main material and used for trenching work on iron plates. It is an electrode for gouging work, which is made by forming a conductive metal coating on the surface of a shaped molded body, and tens to hundreds of carbon fibers arranged almost in the same direction in the fiber length direction are bonded with a binder such as tar, pitch, or synthetic resin. The electrodes are tied together to form a roughly round rod or string-shaped molded body, and by forming a relatively thin conductive metal coating such as copper plating or aluminum metallization on the surface, the entire electrode becomes flexible. The purpose of this project is to propose a new carbon electrode for gouging in which a long outer rod or string-like electrode is obtained, which is wound into a roll, and the gouging operation can be performed continuously by sequentially supplying the electrode. be.

Conventionally, carbon electrodes used for gouging and plasting work (hereinafter simply referred to as "carbon electrodes for gouging") are usually made of carbon powder such as natural or artificial graphite or petroleum coke, and are mixed with tar or other carbon powder. A binder such as pitch is added, kneaded (heated and kneaded), and generally formed into a round bar, which is then fired at 1,000 to 1,500°C.Then, the circumferential surface of the round bar is coated with conductive material such as copper plating or aluminum metallicon. It is a carbon electrode rod on which a metal coating is formed, and its diameter is about 4 to 20 cm and the total length is about 30 to 50 cm.
The lnth one is mainly used for gouging work.

However, when such conventional electrode rods for gouging are used, there are many unresolved problems regarding the work and safety of the parts where the electrode rods are held by the holders, and these remaining parts are difficult to solve. The length of the part is approximately 7~10C
It was considered unusable once it reached WL rank.

Therefore, in order to eliminate such drawbacks and completely use up the electrode rod, an attempt was made to provide male and female parts at both ends of the electrode rod and connect the electrode rods by fitting them together, thereby making full use of the electrode rod continuously. Many inventions and ideas related to this have been proposed, but at present there are many unresolved problems with such connected electrode rods, such as the inability to apply them to electrode rods with a diameter of 8 El or less. However, the current situation is that this method does not necessarily achieve its purpose because it has drawbacks such as the old electrode falling through when the connection part is heated.

Therefore, it would be ideal to obtain a long electrode rod for gouging and use it continuously for a long time, but this is also possible by molding various carbon materials like conventional electrode rods. Producing long electrode rods by post-firing and transporting and using them is practically impossible because the electrode rods may be damaged and various inconveniences arise in handling them.

Carbon electrodes for gouging are generally used in a working method called the arc air method, which means that a high-speed flow of air is ejected along the carbon electrode at the same time as the base metal, such as an iron plate, is melted. Since the molten metal is removed mechanically, the physical properties required of the electrode material for this purpose are that it is a non-metal, conducts electricity and heat well, has good workability, and has a high melting point. In addition, it has sublimation properties.

Currently, carbonaceous materials are the only materials that can be found that have such various physical properties.

In view of these circumstances, the inventors of the present invention have conducted various studies in order to make gouging electrodes flexible and capable of continuous use over a long length. By selectively using flexible carbon fibers as the main raw material), carbon fibers have the properties inherent to carbonaceous materials and are flexible. After twisting the fiber bundles in the same arrangement or molding them with a binding material such as resin and binding them into long carbon fibers, the carbon fibers are heated and hardened by the binding material in the fiber bundles. By forming a conductive film with copper plating, etc. to obtain a long and flexible carbonaceous electrode, and using it for gouging work, we came up with a way to make it possible to make it continuous. Ivy.

In other words, relatively long carbon fibers made by pre-oxidizing or melt-preventing polyvinyl alcohol (PVA) fibers or pitch fibers and then forming them in an inert atmosphere are twisted to a certain thickness in advance. The fiber bundles arranged in the fiber length direction are immersed in, for example, a phenolic resin solution,
After heat-treating this fiber bundle at about 100 to 150°C to heat-cure the fiber bundle, a relatively thin copper plating film is formed on the surface of the fiber bundle using a normal method. A high quality electrode can be obtained.

By winding such long and flexible carbonaceous electrodes around a drum or the like like welding wire and using them one after another, it is possible to perform gouging work automatically and continuously. Now I can do it.

Moreover, the diameter of the electrode rod, which could not be obtained with conventional methods, is approximately 4.
It has become possible to obtain so-called ultra-fine electrode rods with a diameter of less than mn, and by making them long, it has become possible to carry out gouging operations such as continuous narrow groove processing.

Example Cellulose-based carbon fibers were arranged in the longitudinal direction of the fibers to form approximately 3 [
When the fiber bundles are made into In-level fiber bundles, immersed in a nitrocellulose solution and then pulled out and twisted and fired in the air to heat and harden them, the nitrocellulose solvent is twisted and fired, and the combustion heat causes the fibers to be twisted and fired. As the nitrocellulose carbonizes, the fiber bundle is thermoset to form a long string (about 3 in diameter).
A carbonaceous molded article 10) was obtained.

After that, the surface of the carbonaceous molded body has a thickness of about 0.0mm.
A 1 m long copper plating film was formed to obtain a long and flexible carbon electrode for gouging.

Claims (1)

[Claims] 1. A flexible long carbon electrode for gouging, characterized in that carbon fibers arranged substantially in the longitudinal direction of the fibers are bound together with a binding material or the like, and a conductive metal coating is formed on their surfaces.