JPS6124130B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method and apparatus for cutting an inner bead generated when an electric resistance welded pipe is welded.

Generally, the bead on the inner surface of the ERW pipe was processed after being cut into long lengths using an inner bead cutting machine, but recently the inner bead was notched before cutting, and the bead was cut into pieces at the same time as the inner bead was cut. Efforts are being made to make this possible.

The method shown in FIG. 1 was considered as a method in which notching is performed as described above and the inner bead is subsequently cut. In FIG. 1, 1 is an electric resistance welded tube, 2 is an inner bead, and 3 is an outer bead. 4 is an external cutting tool for cutting this external bead. 5 is a notch holder, and a notch roller 6 and a notch lower roller 7 are attached to the notch holder. This notsuchirola 6
The notch bite 8 shown enlarged in Fig. 2 is the third
As shown in the figure, it is attached with a screw 10 via a notch presser claw 9. 11 is an inner bead trimmer, and an inner bead upper roller 12, an inner bead lower roller 13, and an inner bead cutting tool 14 are attached to the inner bead trimmer.

In the above-mentioned device, by relatively moving the ERW tube 1, the outer surface bit 4, the notch holder 5, and the inner bead trimmer 11 in the axial direction of the ERW tube 1, the outer surface bead 3 is attached to the outer surface bite 4. The inner bead 2 is then notched 15 by a notching tool 8, and then cut by an inner bead cutting tool 14. The inner bead 2 is cut into pieces by the notch bit 8 since it is notched 15 perpendicularly to the tube axis by the notch bit 8 described above. Reference numeral 16 indicates this shredded bead.

However, the above-mentioned device had the following drawbacks.

(a) A notch presser pawl 9 is required to attach the notch bar 8, and since the structure of the notch presser pawl 9 becomes weaker as the diameter of the pipe becomes smaller, there is a risk that the notch bar 8 may fall off.

(b) The structure of the notch roller 6 is complicated, and it is difficult to improve the precision in processing.

(c) Since the bite surface is perpendicular to the bead 2, the load it receives is large and the cutting edge is likely to break.

(d) Since notching is performed in the direction perpendicular to the bead 2, the inner bead cutting tool, which has a cutting edge in the direction perpendicular to the inner bead, cuts the inner surface at the notch part in synchronization with the notch interval made earlier. The force applied to the cutting tool instantly decreases, and the next bead cutting starts with an impact, which tends to make the cutting of the notched area unstable, and the concave notch mark 17 can become a flaw after cutting. remain. Even if these notch marks are within the specifications, they will be magnified as dents when inspecting the inner surface, and the quality will deteriorate.

(e) Since the number of notching bits 8 that can be attached to the notching roller 6 is limited to two, and therefore the cutting length is limited, bead clogging is likely to occur.

The present invention provides a method and apparatus for cutting an inner weld bead of an electric resistance welded pipe, which eliminates the above-mentioned drawbacks.

An embodiment of the present invention will be described in detail below with reference to FIGS. 4 to 7. In FIGS. 4 and 5, reference numeral 18 denotes a notch roller which is rotatably fixed to the bead trimmer 11 in the direction of the tube axis, and a diagonal notch bit (notch bit) 19 is attached to this notch roller with a screw 20. There is. As shown in FIGS. 6 and 7, this notching tool 19 is integrally constructed with a cutting edge 21 and a mounting portion 22, and this cutting edge 21 attaches the notching roller 18 to the notching holder 5 explained in FIG. 1. When installed, it is formed to be inclined with respect to the tube axis. Therefore, by notching the inner bead 2 with the notch bit 19, a notch inclined to the bead 2 can be obtained. This notched bead is removed by the internal bead cutting tool that follows the notching tool, but the cutting direction of the notch and the direction of the cutting edge of the internal bead cutting tool do not match, so cutting with the internal bead cutting tool is interrupted. As a result, the force applied to the bead cutting tool does not change suddenly, resulting in smooth cutting and smooth bead cutting marks. In addition, in FIGS. 4 and 5 above, the notch roller 1 to which four notch bits 19 can be attached is shown.
8 is illustrated.

The method and apparatus for cutting an inner weld bead of an electric resistance welded pipe described with reference to FIGS. 4 to 7 above have the following effects.

(a) Since the notch bite 19 can be directly screwed, falling off is reduced, and the structure of the roller 18 is simplified, making it easier to measure and process with high precision.

(b) Due to the diagonal biting structure, notch bite 1
9, the number of chips is significantly reduced, and since cutting with the inner bead cutting tool does not break, it is difficult to leave notch marks after cutting, and the quality is improved.

(c) Conventionally, only two notch bits could be attached to the notch roller 18, which has the same diameter as the roller with four notch bites.
It is possible to install notch bits 19,
Therefore, the bead cutting length was shortened and bead clogging was eliminated.

(d) Efficiency and yield are improved because the downtime of the pipe making machine is reduced.

(e) For example, in the case of low-temperature piping, etc., where impact characteristics are a problem, notches were not previously used because notches would cause problems, but now it is now possible to notch even such severe types. Safety is ensured by eliminating the need for bead cutting using a bench after the traveling cutting machine.

In the above embodiment, an example of an inner bead is shown, but the present invention can also be applied to notching an outer bead.

[Brief explanation of the drawing]

1 to 3 show an example of the background art of this invention, and FIG. 1 is a block diagram of the entire device;
Figure 2 is a sectional view of the main part, Figure 3 is a partial perspective view of the main part, Figures 4 to 7 show an embodiment of the present invention, and Figure 4 is a diagram of the main part. 5 is a longitudinal sectional front view of the device shown in FIG. 4, FIG. 6 is a partial perspective view of the main part, and FIG. 7 is a plan view of the device shown in FIG. 6. 1: ERW pipe, 2: Inner bead, 18: Knot roller, 19: Knot bite, 21: Cutting edge, 22:
Mounting part.

Claims (1)

[Claims] 1. When cutting the inner weld bead of the ERW pipe,
A method for cutting an inner weld bead of an electric resistance welded pipe, characterized in that, before cutting the bead, a notch is made in the bead in a direction oblique to the tube axis direction of the electric resistance welded pipe. 2. A notched cutting tool with a cutting edge arranged in a direction inclined with respect to the tube axis direction in front of the cutting tool for the inner weld bead of the electric resistance welded pipe, and the cutting tool is attached and pivoted so as to be rotatable in the tube axis direction. An apparatus for cutting an inner weld bead of an electric resistance welded pipe, characterized by comprising a roller.