JPH0760506A - Cutting tool for cutting inner bevel - Google Patents

Abstract

PURPOSE:To cut an inner bevel of a weld member stably at high precision by providing a cutting edge for cutting an inner wall at a specified angle to a center line from a pipe end part of a weld joint toward the other end, and a cutting edge for cutting a pipe end. CONSTITUTION:A first cutting edge 101 for cutting an inner bevel forming a specified angle to a center line of a pipe at a cutting tool 100 in a pipe inner wall is inserted into the pipe, and it is fed in the depth direction to form the bevel in the pipe inner wall. A second cutting edge 102 at this cutting tool 100 is applied to a pipe end, when the inner bevel is completed. If the cutting tool 100 is fed further, form of the inner bevel is fixed constantly because a pipe end is cut by the second cutting edge 102 simultaneously with cutting by the first cutting edge 101. The inner bevel of the same form can thus be formed without playing special attention in feeding the cutting tool.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal groove cutting tool, and more particularly, to easily and accurately perform internal groove cutting for making a bead width of welding uniform and narrow. The present invention relates to a bit for internal groove cutting that can be performed.

[0002]

[Related Art] High integration of semiconductor devices is increasing more and more, and at the same time, high performance of characteristics is being advanced. Along with this, the semiconductor manufacturing apparatus, the manufacturing atmosphere are highly purified, and the gas, ultrapure water, and the like are further highly purified.

Conventionally, a gas supply pipe system used in a semiconductor manufacturing process is formed by welding various pipes, joints, valves and the like. As a welding method, for example, in the case of stainless steel pipes, the pipe ends of two pipes are butted against each other, and tungsten inert gas welding, arc gas welding,
A welding method such as electron beam welding is used.

However, in the case of welding by such a method, there is a problem that the bead width becomes nonuniform and widens, resulting in contamination of process gas and the like. That is, although metal fumes are generated during welding, widening the bead width means that metal fumes that evaporate and fly increase. The metal fumes are cooled and reattached in the vicinity of the welded portion, and are peeled off when a corrosive gas or the like is flown, which contaminates the gas and the process atmosphere and eventually deteriorates the characteristics of the semiconductor device to be manufactured. Further, since the bead portion has a rough surface and gas is easily adsorbed, the adsorbed gas is gradually desorbed to contaminate the process atmosphere. Furthermore, chromium beads are deposited in the bead portion, which causes intergranular corrosion depending on the gas used.

For the above-mentioned reasons, in the semiconductor manufacturing-related apparatus, it is desired to make the bead width of the welded portion as narrow as possible. As a measure for this, the present inventor uses a welding method in which an inner groove with a predetermined angle is cut at the pipe end in the other end direction with an accuracy of about 0.05 mm, and the ends are butted and welded along the outer circumference. Invented

However, in order to cut the inner groove with such accuracy, it is necessary to perform the cutting while precisely controlling the feed of the cutting tool by using a lathe or the like. Such an operation takes time and has a problem that processing productivity is extremely low.

[0007]

SUMMARY OF THE INVENTION In view of the above situation, the present invention does not require the accuracy of the feed of the cutting tool and is capable of stably cutting the inner groove of the same shape. The object is to provide a cutting tool.

[0008]

An internal groove cutting tool according to the present invention is a bit for cutting an internal groove on a pipe end portion of a welded joint, and is provided from the pipe end portion to the other end. It is characterized by having a first cutting blade for cutting the inner wall at a predetermined angle with respect to the facing center line and a second cutting blade for cutting the pipe end.

[0009]

The bite of the present invention has a first cutting blade for cutting an inner groove formed at a predetermined angle with respect to the center line of the pipe on the inner wall of the pipe, and a second cutting blade for cutting the pipe end. It has a blade. Therefore, a groove is formed on the inner wall of the pipe by inserting the cutting tool into the pipe with the first cutting blade and feeding it in the depth direction. Also, the inner groove is completed when the second cutting edge hits the pipe end, but even if a further bite is sent, the pipe end is cut by the second cutting blade at the same time as cutting by the first cutting blade. Since it is cut, the shape of the inner groove is always constant. Therefore, the inner groove of the same shape can be always processed without paying attention to the feeding of the cutting tool, and the processing productivity is remarkably improved.

[0010]

EXAMPLES The present invention will be described in more detail with reference to the following examples.

FIG. 1 shows an example of the byte of the present invention. The bite 100 in FIG. 1 is a 1/4 inch stainless steel tube (SU
S316L) is a cutting tool for cutting an internal groove with an angle of 65 ° and a depth of 0.2 mm. The first cutting blade 101 and the second cutting blade 102 are cut on both sides of the center line AA ′. It is a double-edged blade.

This bite is attached to a simple lathe, and 1
100 pieces of / 4 inch pipes were cut. For comparison, the same single-edged cutting tool was used for the same cutting process.

Further, by using the cutting tool of this embodiment, it is not necessary to precisely control the cutting tool feed as compared with the conventional cutting tool, so that it only takes half the time and the cutting process can be performed. I was able to shorten it.

When the bite of this embodiment was used, the depths of all the internal grooves were within the range of 0.15 to 0.25 mm, whereas when the conventional bite was used, the time Even though the feed was controlled by multiplying by 74, 74% of them were in the above range.

As is clear from the above, it is understood that the internal groove can be easily processed with good reproducibility by using the cutting tool of this embodiment.

Next, 20 sets of butt welds of two welded joints of a 1 / 4-inch diameter tube that has been subjected to internal groove cutting were carried out by an automatic welding machine (SPB100 manufactured by AstroArc Co.) using the tungsten inert gas welding method. (Fig. 1
(B)).

After welding, the welded part was cut into a plane including the central axis, and the internal bead part was observed.

The tube of the comparative example has a bead width of 0.2 to 0.6.
In the case of all 20 sets, the bead width falls within the range of 0.4 to 0.5 mm, and the uniform and narrow width is 18%. It was confirmed that a bead was obtained.

Although a double-edged cutting tool is used in this embodiment, it goes without saying that a single-edged cutting tool may be used. However, when a plurality of cutting blades are provided at equal angle positions, the cutting force is more uniform and uneven cutting is caused. Can be prevented. In addition, the byte of this embodiment is
It is an integrated type bite made by cutting out the cutting blade,
The cutting blade may be attached to the base body (shank).

Further, the shape of the cutting tool is not limited to the thin plate shape as in this embodiment, but the first cutting blade for forming the groove on the inner wall of the pipe and the second cutting blade for cutting the pipe end. Any shape may be used as long as it is provided.

[0021]

According to the present invention, the inner groove of the welding member can be stably cut with high accuracy. As a result, welding of narrow beads can be performed with good reproducibility, and it can be suitably applied to welding of highly clean semiconductor manufacturing equipment and the like.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a cutting tool of the present invention.

[Explanation of symbols]

 100 bytes, 101 1st cutting blade, 102 2nd cutting blade.

Claims (1)

[Claims] 1. A cutting tool for cutting an inner groove in a pipe end portion of a welded joint, for cutting an inner wall from the pipe end portion to the other end at a predetermined angle with respect to a center line. First
An internal groove cutting tool having a cutting edge of and a second cutting edge for cutting a pipe end.