JPH0252599B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a connected type gouging carbon electrode rod, and more specifically, in a connected type gouging electrode rod that is fitted and connected by a convex portion and a recessed portion, the present invention relates to a connected type gouging electrode rod that is fitted and connected by a convex portion and a concave portion. The present invention relates to a carbon electrode rod for connecting type gouging, characterized in that a lubricating film is formed on a part or the entire surface of the carbon electrode rod. In the past, many connected carbon electrode rods have been proposed, but the shape of the fitting connection part is typically a convex part and a concave part. Proposals have been made and put into practice to prevent the loss caused by the connecting tip electrode falling off. However, in the above conventional example, if the processing accuracy of the carbon part at the connection part of the electrode rod or the thickness accuracy of the metal coating is poor, the fitting resistance becomes large.
Although there is a drawback that it is difficult to connect one carbon electrode rod to another carbon electrode rod of the same type, there have been no proposals to reduce the fitting resistance force, and the fitting resistance force has been reduced. This remained an unresolved problem since a certain value was required when connecting the electrode rod. Therefore, if the fitting resistance force is large, the convex part may break from the base or the concave part may crack at the peripheral edge, resulting in disadvantages such as not being able to fully demonstrate its function as a connected carbon electrode rod. . The present invention provides a connected carbon electrode rod that eliminates and improves the drawbacks of the conventional electrode rods, significantly reduces the fitting resistance when connecting the electrode rods, and reduces the possibility of the electrode rods coming off during use. The purpose is to provide the following. That is, the present invention provides a connection type carbon electrode rod in which a convex part is inserted into a concave part for fitting connection. By applying an activator or a lubricant made of various polymeric compounds to form a lubricating film, the fitting resistance force when connecting the electrode rod is reduced, and the fitting resistance when the electrode rod is used is reduced. The object of the present invention is to provide a carbon electrode rod for a connected type gouging according to the above claims, which can increase the joint strength and reduce the possibility of the electrode rod falling off during combustion. Hereinafter, the present invention will be specifically explained in detail based on examples and the like. Gouging is generally a general term for forming grooves for welding on the surface of the base metal using the arc combustion heat of a carbon electrode rod, and plasting work in which excess weld build-up is removed. It is. The carbon electrode used in the above-mentioned gouging work (hereinafter also referred to as carbon electrode for gouging) is made by adding a binder such as tarpitz to carbonaceous powder such as artificial graphite, coke, or carbon black and heating and mixing the mixture. The diameter is 6mm~19mm
It is manufactured by molding it into a cylindrical shape, firing it, and finishing it. By the way, in order to use the carbon electrode rod for gouging continuously for a long time, the convex part of one electrode rod is fitted and connected to the recessed part of the other electrode rod, so that the old electrode rod and this electrode rod are connected to each other during arc combustion. It is necessary to connect the new electrode to be mated and connected. For this reason, in connection type carbon electrode rods for gouging, the old electrode and new electrode are sequentially fitted and connected during gouging work, but if the fitting resistance is large, the electrode rod can be inserted while performing gouging work with one hand. It is necessary to fit the other easily and quickly with one hand. Therefore, the present invention provides a method of applying various types of oils such as oil, grease, etc., such as vegetable oil, animal oil, mineral oil, and synthetic oil, to part or all of the surface of either or both of the convex portions and concave portions of the electrode rod for connection type gouging. oil or grease-like lubricants or metal soaps;
surfactants such as organic or inorganic polymer compounds;
By coating with one or more lubricants to form a lubricating film, the fitting resistance force when connecting the electrode rods is reduced, and the connection between old and new electrode rods is made simple and quick. It has been newly discovered that the interposition of the lubricating coating increases the strength of the fit between the new and old electrode rods when the electrode rods are used, that is, during gouging work, and that the possibility of the electrode rods coming off during combustion (so-called stub loss) is significantly reduced. ,
It was completed based on this. In the above-mentioned connected carbon electrode rod for gouging, it is particularly preferable that the lubricating film be formed on the base of the protrusion or the peripheral edge of the recess and its vicinity, but it is also possible to form the lubricating film on the entire surface of the protrusion or recess. There is no particular inconvenience. Furthermore, as the material for forming the lubricating film, the above-mentioned surfactants or lubricants such as oils and fats, organic or inorganic polymers, etc. are particularly preferable as long as they have the following properties. In other words, (a) lubricity;
(b) Adhesive or sticky, (c) Non-volatile, (d) Less deterioration and discoloration due to aging, (e) No corrosion of coating metals, such as copper plating or aluminum spray coating. It has various properties. Furthermore, the method for forming the lubricating film may be an impregnation method, or any of various coating methods, such as spray coating, brushing, or flow coater coating. The timing of formation of the above-mentioned lubricating film is as follows:
(a) Any time during the manufacture of the electrode during the finish inspection process of the electrode after metal coating has been applied to the electrode, or (b) During use of the electrode during gouging work, or (c) It may be carried out at any time during this period, but particularly preferably (d) before the inspection after polishing the metal coating, or (e) immediately before the use of the electrode in the gouging operation. This is because the lubricating film can be formed relatively efficiently, simply and quickly, and there is little loss of lubricant and the like. Next, embodiments of the present invention will be described together with their implementation effects. Example: The base part of each of the 10 protrusions of a carbon electrode rod for connecting type gouging with a diameter of 19 mm and a length of 355 mm is coated with metal coating, such as copper plating or aluminum metallicon, continuously from the outer peripheral surface of the electrode body. A lubricating film of grease or machine oil was formed on the surface. The fitting resistance force when these electrode rods were respectively fitted and connected was measured using an Amsler universal testing machine, and the results shown in Table 1 were obtained. The measurement results of a current electrode rod (without a lubricating coating) tested under the same conditions as a comparative example are also listed.

[Table] The force (Kg) required for the above bonding is calculated by holding two carbon electrode rods of each sample in an Amsler universal testing machine, and applying force to the protrusion of each electrode at a speed of 5 mm per minute. This is the force required for joining when the recess and the recess are fitted together. Furthermore, the ratio in parentheses in Table 1 indicates the reduction ratio of the fitting resistance force calculated by setting the measured value of the current electrode rod (without a lubricating coating) as 100. Next, we will discuss the measurement conditions when the electrode rods fitted and connected as described above are used for gouging work while arc burning, and the length of the electrode rods falling out at this time, that is, the old electrode rods during combustion. The length of the electrode and the dropout loss rate of the stud broth are shown in parentheses in Table 2. The measurement method is as follows. a Carbon: 19φ×355 (mm) b Joining method: Cut with a saw at a position 160 mm from the convex part and connect to the concave part c Test conditions: Current 1600 to 2000 (A) d Base material: Soft iron e Work details: Base material surface Adjustment f Measurement quantity: 10 each g Ratio is calculated assuming the current product (without coating) as 100

[Table] As is clear from Tables 1 and 2 above, the carbon electrode rod for connection type gouging of the present invention exhibits the following effects. (1) By forming a lubricating film on a part of the surface of the convex or concave parts, the mating resistance force (the force required for mating) is reduced by about 15 to 20% compared to the current product, that is, conventional products, making it easier to use during gouging work. It became possible to easily and quickly fit and connect the electrode rods, and the workability was improved. (2) In addition to the above effects, the range of variation in fitting resistance was reduced by 50 to 60% compared to the conventional one. This is caused by breakage at the base of the convex part or concave part caused by poor machining accuracy of the convex part and concave part of the electrode, as well as poor thickness accuracy of the metal coating film that continues from the outer periphery of the electrode body on a part of the part. The occurrence of defects such as cracks and chips in the electrode is reduced, and the defective rate of the electrode can be reduced by about 3% compared to the conventional electrode, which is economically advantageous. (3) The loss of the old electrode falling off during combustion during gouging work is reduced by 5 to 10% compared to the conventional one, making it economically advantageous. As described above, according to the present invention, by forming a lubricating film on the surface of either or both of the convex portions and concave portions of the carbon electrode rod for connection type gouging, the fitting connection can be made simple and quick. It has the effect of reducing dropout losses during use.

Claims (1)

[Scope of Claims] 1. In a carbon electrode rod for a connected type gouging, in which one carbon electrode rod is used by fittingly connecting one carbon electrode rod to another carbon electrode rod of the same type in the axial direction, the convex surface or concave surface of the fitting connection part A carbon electrode rod for a connected type gouging, characterized in that a lubricating film is formed on the surface of one or both of the parts. 2. A patent claim characterized in that at least a lubricating coating is formed on the surface of either the concave part or the convex part of the fitting connection part, where the metal coating is applied. The electrode rod according to scope 1. 3. Claim 1 or 2, characterized in that the lubricating coating is formed in any step after the metal coating of the electrode rod is applied and before the finish inspection of the electrode rod. electrode rod. 4. Claim 1, characterized in that the lubricating film is formed immediately before the electrode rod is used.
The electrode rod according to items 3 to 3.