JPH0334417B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of forming water cooling holes in conductive materials for welding machines, such as gun arms, electrodes, etc., having water cooling holes.

BACKGROUND OF THE INVENTION Gun arms, electrodes, and the like that are conductive materials for welding machines become extremely hot because a large current flows through the conductive materials during welding operations. Therefore, it has been common practice to provide water cooling holes in the conductive material for cooling the conductive material with cooling water. Copper tubes or nickel alloy tubes have been used as conductive water-cooled tubes. These tubes are placed in the mold when the conductive material is cast, so that the water cooling holes are formed once casting is complete.

Problems to be Solved by the Invention Since these copper tubes or nickel alloy tubes can be easily bent, they can be easily shaped to fit a desired cooling water passage.

However, in the former case, during the casting of the conductive material, oxides on the surface of the copper tube or due to the difference in thermal conductivity between copper and the hot water, which has excellent thermal conductivity, caused rapid cooling of the hot water, and the latter In both cases, due to gas molecules adhering to the surface of the nickel tube,
Pinholes, cavities, or rough skin appeared near the tube surface, sometimes resulting in defective products that could not be used or causing water leakage during use. In addition, because a copper tube or a nickel tube is used, the flow rate of cooling water through both tubes is reduced by an amount corresponding to the wall thickness of the tube, and the conductive material cannot be cooled sufficiently. had drawbacks such as poor cooling efficiency due to its low thermal conductivity.

In order to eliminate these drawbacks, a conductive material for a welding machine was cast with a glass tube placed in advance at the location that would become the water cooling hole, and the glass tube formed the part that would become the cooling water passage in the future. It is conceivable that the conductive material is molded in the state, and then the glass tube is melted to form the water-cooled tube directly from the conductive material itself.

However, the water cooling hole in the conductive material has not only straight parts but also many curved parts due to the shape of the conductive material and the formation of the cooling water inlet and outlet, etc. When looking at the entire water cooling hole, it is three-dimensionally curved. There is.

Therefore, even if a single glass tube is heated and bent according to the desired water cooling hole to form the part that will become the water cooling hole in the future, it is difficult to form it accurately using the copper tube or nickel alloy. There are problems in that it is more difficult than molding with a manufactured pipe, and furthermore, the correction is very troublesome.

Means for Solving the Problems The present invention aims to solve the above-mentioned problems by ultimately forming a water cooling pipe directly with the conductive material itself, and the method for forming the water cooling holes is It has characteristics.

That is, the part of the conductive material for a welding machine that will become the water cooling hole is made in advance from a heat-resistant glass tube consisting of an elbow and a straight pipe without heat processing, and with this part placed in the mold, hot water is poured into the mold. A conductive material is formed with a glass tube forming a part that will become a passage for cooling water in the future, and then the conductive material is immersed in a strong alkaline liquid to completely dissolve the glass tube. As a result, the location where the glass tube was present becomes a hole, thereby forming a water cooling hole in the conductive material.

Function: The area in the mold that will become the future cooling water passage is precisely secured by a heat-resistant glass tube consisting of an elbow and a straight tube, and after casting, this is removed with a strong alkaline liquid and turned into a conductive material. A smooth cooling water passage is formed by the conductive material itself.

Therefore, the cooling water can be applied directly to the conductive material.

Example To explain the case of forming a gun arm as a conductive material for a welding machine, generally the gun arm is
As shown in Figures 3 to 3, a cooling water inlet 1 is formed on the side surface of the rear end of the top, and is bent 90 degrees from this inlet toward the arm center axis (A), and then toward the front of the arm. It is bent by 90 degrees (B), and further bent downward by 90 degrees at the front end (C), so that its lower end is connected to the tube 3 provided on the electrode holder 2, and the cooling water is supplied during this time. The tube is a straight tube except for the bent portion. and,
Cooling water enters the tube 3 from the inlet 1 through a bent pipe and a straight pipe, and from this tube 3 flows into the tip 4.
Go inside and cool down Chip 4. The water that has been heated by cooling the tip 4 returns through the return tube 5 and enters the arm. The cooling water return pipe in this arm is also formed by a curved pipe and a straight pipe. That is, a straight pipe provided parallel to the supply pipe extending upward from the front lower end of the arm is bent 90 degrees rearward at its top (d), and bent along the downward slope of the arm from the rear end of the top (d). The cooling water supply pipe is bent vertically at its lower end (F) and further bent by 90 degrees toward the outlet 6 on the side of the arm (G). part, and the return pipe is d.
It has bent portions E, H, and G, and a straight pipe is formed between the bent portions, but the bending direction is three-dimensional.

In the present invention, elbows made of heat-resistant glass are used for the bent portions A, B, and C of the locations that will become cooling water supply passages in the future, and elbows made of heat-resistant glass are used to connect them. A straight pipe was prepared in advance to have the same shape as the desired cooling water passage, and the bent portions (N, E, H, and G), which will become the cooling water return passage in the future, were made of heat-resistant glass. Using an elbow and a straight pipe made of heat-resistant glass as a connection between the elbows, the pipe is prepared in advance in the same shape as the desired cooling water passage without heat processing.

When manufacturing a gun arm using, for example, beryllium copper, a mold is first made according to the original model of the gun arm, and the pre-prepared elbow and Install a straight quartz tube. Next, pour hot water made of beryllium copper into this mold,
After waiting for it to cool down, take out the cast gun arm with the water cooling hole formed in the quartz tube and heat it to 600℃~
The cast product is immersed in a caustic soda solution heated to 650° C. for about 30 minutes or more. Through this step, the quartz tube is dissolved by caustic soda. Once the quartz tube has been sufficiently dissolved, the cast product is taken out of the caustic soda solution and thoroughly washed with water to form the final product.

Note that the time for the cast product to be immersed in the caustic soda solution may be extended to several hours depending on the length and wall thickness of the quartz tube. In addition, as the heat-resistant glass, well-known heat-resistant glass for the outer surface of a quartz tube may be used.
Furthermore, caustic potash such as caustic soda may be used as the strong alkaline liquid.

As a means of connecting the elbow and straight pipe,
The straight pipe 8 may be directly inserted into the elbow 7 as shown in FIG. 4 without adding any heating means, or the outside diameters of the elbow 7 and the straight pipe 8 may be made the same as shown in FIG. In addition, a small diameter pipe 9 for connection may be further used between the two.

Effects In the present invention, when molding a water-cooled tube, a heat-resistant glass tube is used without using a copper tube or a nickel tube when casting a conductive material, so there are no pinholes on the surface of the glass tube of the molded casting. In addition, after the glass is melted with a strong alkaline liquid, smooth water cooling holes are formed by the conductive material itself, so the wall thickness is equivalent to that of conventional water cooling pipes. Since there is no part to cool, a large amount of cooling water can be supplied, and the cooling water acts directly on the conductive material, a conductive material with high cooling effect can be obtained.

Furthermore, since the glass tube is constructed from a combination of an elbow and a straight tube, it can be shaped very accurately. In other words, the direction in which the elbow is directed with respect to the straight pipe can be freely determined, and the bending angle can be easily modified by applying appropriate force to both ends of the elbow. Therefore, the glass part made for the cooling water passage is very precise, and
Its production is also very simple, requiring no heat processing.

[Brief explanation of drawings]

Figure 1 is a side view of the arm to explain the water cooling holes in the gun arm, Figure 2 is its front view, and Figure 3 is a side view of the gun arm.
4 is a sectional view showing a connection between an elbow and a straight pipe, and FIG. 5 is a sectional view showing a connection between an elbow and a straight pipe in another embodiment. 7...Elbow, 8...Straight pipe, 9...Connecting pipe.

Claims (1)

[Scope of Claims] 1. A portion of a conductive material for a welding machine that will become a water cooling hole is made in advance from a heat-resistant glass tube consisting of an elbow and a straight tube, and this is placed inside the mold. For a welding machine, the conductive material for a welding machine is formed by pouring hot water into the conductive material, and then immersing the conductive material in a strong alkaline liquid to melt the glass tube, thereby forming a water cooling hole in the conductive material. Method for forming water cooling holes in conductive materials. 2. A method for forming a water cooling hole in a conductive material for a welding machine according to claim 1, wherein the elbow and the straight pipe have the same outer diameter and are connected by a connecting member. .