JPS6228111A - Cutting method for pipe in seam welded pipe manufacturing equipment - Google Patents

Abstract

PURPOSE:To form a good cut surface, by clamping a raw pipe before and after its position to be cut by chucks while providing a cut over the whole periphery of the raw pipe in the position to be cut and reciprocatingly turning only one chuck forwardly and reversely for breaking the pipe. CONSTITUTION:A seam welded pipe A is clamped by chucks before and after its position to be cut. A V-shaped cut B is formed by a cutting machine in the position to be cut. The depth of the cut and its shape is set to an experimentally optimum value and form. The tube is cut from the cut part by reciprocatingly turning only the chuck in the downstream side forwardly and reversely. Since the cutting method is to cut the tube by means of reciprocating twist to generate large stress in the cut B for breaking the tube, deformation, return and a burr can be prevented from being generated on the cut surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a tube cutting method for cutting continuously fed tubes into predetermined lengths in an electric resistance welded tube manufacturing facility.

The cutting equipment used in electric resistance welded pipe manufacturing equipment needs to cut while moving along with the pipe that is continuously fed out.For this reason, it is assumed that the cutting equipment can cut the pipe in a short period of time. Become. Conventional cutting methods that meet this premise include a method of friction cutting by rotating a saw blade (7-reaction saw) at high speed, a method of swinging down a blade built into a guiset and cutting off the thickness of the blade by shearing,
A method using a rotary disc cutter, in which multiple circular blades with sharp outer peripheral edges are rotated in the circumferential direction around the tube and narrowed down to cut it (only for pigeonholes of round tubes), a cutting force method using a plasma arc, etc. I've been hired.

[Problem 1 that My Brother is trying to resolve] Each of the conventional cutting methods described above has the disadvantage that the edge of the cut end becomes deformed or burrs or cracks occur at the cut end. For example, in the method using Guiset, there is no lower blade in the upper part of the pipe cross section and the pipe is simply pierced with a knife, so deformation is large and occurs. In the case of a rotary disc cutter, burrs are large. 7 In the case of a traction saw or plasma arc cutting, deformation is not so much of a problem, but the occurrence of cracks is significant.

The above-mentioned deformations are corrected or re-cut in the post-process, and burrs and burrs are removed using a grinder or the like in the post-process, but this work is not easy9 and requires a great deal of effort.

Furthermore, as mentioned above, it is extremely important that the time required for cutting is short, and this often limits the speed of pipe production, but with Ike's method other than the Guiscent method, it is desirable to be able to cut in an even shorter time.

This invention is an attempt to solve the above-mentioned problems of the conventional method, and is intended to prevent deformation, burrs, and burrs from occurring at the cutting end, and to cut a pipe in a short time in an electric welded pipe manufacturing equipment. Make a promise to get the cutting method.

[Means for solving the problem 1 In this invention, in order to solve the above problems, the electronic!
:'After SS and before the round material tube passes through the sizing rolls, a cut is made around the entire circumference of the material tube at the position where it should be cut, and reduction is applied by the sizing rolls to make it into a perfect circle with a predetermined shape and dimensions. After the tube is made into a round or square tube, the tube is gripped by chunks at the front and rear of the cut position, and then only the chuck on the downstream side is driven to reciprocate in the forward and reverse directions to break the cut portion.

1 Effect 1 When the chuck on the downstream side is driven to reciprocate in the forward and reverse directions, twisting force is applied to the tube, stress is concentrated at the notch due to the notch effect, and the tube breaks at the notch. In this case, since the tube is twisted back and forth in the forward and reverse directions, severe stress is generated in the blocked portion, and cutting is therefore possible even if the distance between the front and rear chucks is somewhat wide.

[Embodiment 1] An embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

Figure ff11 shows an electric AW4 to which the cutting method of the present invention is applied.
FIG. 2 is an overall side view of the pipe manufacturing equipment. A coiled hot-rolled band 2 supported by an uncoiler 1 is sent out by pinch rolls 3, flattened by a leveler 4, and sheared by a shear 5 and
The welding connection between the rear end of the previous coil and the tip of the next coil is made by Entwerg 6, and through the underground louver 7 for maintaining the supply of material to the V-making machine during the welding connection. Sent to 1uTF Iso's breakdown roll 8. In this breakdown roll 8, the band is formed into a circular shape, and then formed into a substantially circular shape by the subsequent fin pass roll 9, and the high frequency resistance (or induction) welding part 1o is electrically welded. Use bead trimmer 1 to trim the excess thickness of the weld.
1 to form a round blank tube. Further, 12 is a cooling table that cools the welded part by pouring cooling oil, 13 is a sizing roll that applies reduction to the round blank tube and forms it into a perfect round tube or square tube of a predetermined shape and size, and 14 is a cooling table that cools the welded part by pouring cooling oil. Turk's Radroll, which corrects warps, bends, and torsions of pipes, is made by cutting 15 and is the same as the conventional one.

Conventionally, a cutting machine is only installed on the downstream side of the call 14 (right side in the figure) on Turk's shoes, but in the present invention, a round piece at the position to be cut is installed on the upstream side of the sizing roll 13. A traveling type incision rock 16 is installed to form a notch that extends all the way around the outer circumference of the pipe.
A twisting cutter 17 is installed on the downstream side of 4, which grips the pipe with chucks before and after the cut, and drives only the chuck on the downstream side to reciprocate in forward and reverse directions to twist the pipe and break the cut. . Note that forward and reverse rotational drive is 1
It is not limited to a round trip, but may be one and a half round trips, two round trips, etc.

In addition, in the embodiment, in order to easily keep the depth of the cut by the cut rock 16 constant over the entire circumference, a welded round blank pipe is placed on the upstream side of the cooling table 12 to form a roughly perfect circle. A breath sizing roll 18 is installed. Note that this presizing roll 18 has a predetermined shape and size, so the size does not matter, and it is simply used to obtain an approximately perfect circle. Therefore, the presizing roll 18 is referred to as a round blank tube immediately after being rolled out.

It does not necessarily need to be installed as long as a constant depth of cut can be obtained.

FIG. 2 shows a rotary disc counter which is an example of the above-mentioned cutting machine 16. This rotary diffuser/ri1
9, for example, three circular blades 20 having an acute outer peripheral edge.
1n1 yuan, Kakeru! ! ! J. Each circular blade 20 driven by the device 21 is rotated in the circumferential direction around the round blank tube A and narrowed to make a cut to a predetermined depth on the outer periphery of the blank tube A. The rotary disc cutter 19 grips the raw pipe A with a clamp (not shown) and forms the above-mentioned cuts while traveling together with the raw pipe A. Other cutting tools that can be used include a rotary cutting tool with a rotating cutting tool and various cutting tools used for cutting round pipes.

An example of the depth and shape of the cut formed by the cut 8!16 is shown in Fig. f53 and Fig. 4, which is an enlarged view of part A of Fig. rjS3. The depth 11 of penetration B is such that it does not break during the sizing process in which it passes through the sizing roll 13.
Also, the depth should be optimal so that the cut surface does not deform during cutting. The depth h varies slightly depending on the pipe shape, material, plate thickness, etc., but for example, for square steel pipes 3, '2 +
According to experiments with cmX 60mmX 60-mm, good cutting with almost no deformation, burrs, etc. can be achieved at approximately 60% to 75% of the plate thickness, with no breakage occurring during the cornering process. It was done. The shape of the cut B should be a ■ shape, or a two-step ■ shape with a large inclination angle at the tip as shown in Figure 4 (to reduce wear on the blade). In the example shown, one side of the tip One has an inclination of 75°, and the other one has an inclination of 15°.

5 and 6 show an example of a chuck for gripping a rectangular tube. 22 is a chuck on the stationary side, and 23 is a chuck on the downstream side, that is, the rotating side. Both chucks 22 and 23 consist of a pair of upper and lower parts each having a U-shaped recess 23a that matches the side dimension of the rectangular tube. For example, P57. As shown in the figure (this is the rotating side), the chuck guide 25 is moved up and down by the hydraulic sill 24 to grip or release the rectangular tube.

Although the chuck guide on the fixed side does not rotate, the chuck guide 25 on the downstream side shown in FIG. Thus, only the downstream chunk 23 111I1 is driven back and forth in the forward and reverse direction as shown by the arrow in FIG. Incidentally, it is also possible to perform the phantom 1η using air silling, and to perform the rotation even more rapidly using other aircraft terminals.

The chuck shown in FIGS. 5 and 6 described above is an arithmetic chuck that uses N objects of specific square dimensions. According to the chunks 29.29 arranged so that they can be moved in this direction, various sizes can be accommodated.

To explain the timing of making a cut with the cutting machine 16 and cutting with the torsion cutting machine 17, the cutting depth is changed to +l! every time it is detected by a measuring roll or the like that the pipe has been fed a predetermined distance. IIG
For twist cutting, a notch detector is attached to 17, and a signal from this notch detector detecting passage of the notch causes the chuck 22 to be cut.
The operation of the chuck 23 is controlled so that the chuck is chunked when the notch B reaches approximately the center of both the fixed and rotating chucks 22 and 23.

The above-mentioned cut detection method includes a method of detecting the cut locally using a detector in contact with the tube, a method of detecting the cut using the reflection of the tube, a method of detecting the cut using the reflection of the tube, or a method of detecting the cut using eddy current flaw detection, ultrasonic flaw detection, It is advisable to adopt the most suitable method, such as an electrical method of detection using technology such as change detection.

The above-mentioned electric resistance welding steel ff5! In the remaining equipment, the welded round blank pipe is welded in step 10. After removing excess thickness with a bead trimmer 11, it is made into a roughly perfect circle with a presizing roll 18, passed through a cooling table 12, and then cut into a cut hole 16.
A notch B is provided at a predetermined position over the entire circumference, and then a perfect round tube or a square tube of a predetermined shape and size is formed by a sizing roll 13, and a Turksend 14
After the bends etc. have been corrected by Hata, twist cutting? ! ! 17
At the same time, the worm 27 and the worm wheel 2 are chunked by the chucks 22 and 23 of the notch B.
8 In, Howsong 2G, Chuck Id 25
At the same time, the chuck 23 on the downstream side is reciprocally rotated in the forward and reverse directions (m, )2, so that the tube is reciprocated by the front and rear chucks 22 and 23 and a twisting force is applied, causing it to break at the notch B. It will be done. After rupture, Char/Ri22,
23 is opened, the product cut by one predetermined number of arms is sent out from the run-out table 15.

Since the above-mentioned cutting is performed by twisting the tube back and forth in the forward and reverse directions, a severer stress is generated in the cut gISB, making it more likely to break than when the tube is rotated and driven only in the -j direction. Therefore, compared to the one-way case, it is possible to make the interval between the chucks 22 and 23 wider after the lTr, and when gripping the pipe in actual equipment, both chucks 22, 2
3, positional accuracy when gripping the front and rear of the notch B is no longer required to be very precise. Therefore, it becomes easy to control the operation of both chucks 22 and 23, and 'y! , it becomes easy to apply in the actual equipment. Furthermore, regarding the rotation angle leading to cutting, the rotation 't+2 angle to one side from the normal position can be smaller than that in one direction, which is preferable in terms of installation.

The conditions for obtaining a good cut are important! There are various factors that affect the depth of cut, the shape, the distance between the front and rear chucks, whether the cut is in the center of the front and rear chucks, the speed of the chuck rotation drive, the size of the chuck, and the material,
It varies depending on the plate thickness, whether it is a round or square tube, its size, etc. These settings may be set optimally through experimentation.

Although the present invention can be applied to both round tubes and square tubes, its advantages are brought out even more in the case of square tubes.

In other words, a rectangular shape generally makes the element difficult to cut compared to a round shape, but in the case of the present invention,
Since the cut is in a round shape, there is no disadvantage in forming the cut, and since the cut is in a square shape at the cutting stage, the shape of the chuck that grips the pipe does not need to be exact. , and a sufficiently large twisting force can be easily generated.

Furthermore, during cornering by the sizing rolls 13, the greatest stress is applied to some of the corners of the square, and the corners are more likely to break than the sides, so the square tube cannot be twisted. This is convenient for breaking.

[Effects of the Invention 1] According to the method of the present invention explained above, a notch is formed in the pipe with the cup of the sizing roll, and after passing through the sizing roll, the front and back of the notch are gripped by chucks, and only the downstream chuck 111Q is moved in the forward and reverse directions. Since the pipe is cut by reciprocating rotation, various excellent effects are achieved as follows.

(i) Unlike the conventional methods, deformation of the cut portion,
The occurrence of burrs and burrs is significantly reduced, and correction in post-processing is possible.
Processing such as re-cutting or removal is no longer necessary.

Therefore, a great deal of labor is saved and processing equipment is no longer required.

(11) Since the pipe can be torsionally ruptured with less twisting force, it is possible to cut the pipe in a shorter time than with conventional rotary disc cutters, 7-wheel saws, plasma arc cutting methods, etc. There are many cases where it is necessary to reduce the amount of time required for disconnection due to limitations on the time required for disconnection.
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(iii) Unlike the Gooset method, no chips are generated, which improves material yield and eliminates the need for pauses for scraping, improving work efficiency.
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(iv) Unlike cutting with a 7-reaction saw, no high level of noise is generated which would cause problems.

(v) Since the reciprocating rotation is driven in the forward and reverse directions, there is a wide limit to the spacing between the front and rear chucks that allows for good cutting, and therefore it is easy to control the front and back of the cutting part to grip it correctly, making it suitable for application in actual equipment. is easy.

[Brief explanation of drawings]

Fig. 1 is an overall side view of the electric TFT steel pipe manufacturing equipment to which the method of the present invention is applied, Fig. 2 is a front view of the main part of the incision, Fig. 3 is a side view of the pipe at the incision, and Fig. 4 is the [Figure 5 is a side view of the chunk part, Figure 6 is a sectional view taken along the line ■-■ in Figure 5, Figure 7 is a front view of the main parts of the helical cutting machine, FIG. 8 is a sectional view showing another embodiment of the chuck. 13... Sizing roll, 16... Cutting machine, 1
7... Twisted cutting allowance, 18... Breathizing roll, 22, 23. 29... Chuck, A... Round pipe, B... Cutting speaker Nichizai Kogyo Co., Ltd. Agent Patent Attorney Yukihiko Kagawa Figure 7 - Figure 8 Figure 3 Figure 5 Figure 4 Figure 6

Claims (1)

[Claims] After ERW welding and before passing through the sizing roll, a notch is formed around the entire circumference of the round material tube at the position where it should be cut, and reduction is applied by the sizing roll to make it into a perfect circle with a predetermined shape and dimensions. After the tube is made into a round or square tube, the tube is gripped by chucks at the front and rear of the cut position, and then only the chuck on the downstream side is driven to reciprocate in forward and reverse directions to break the cut portion. A method for cutting pipes in ERW pipe manufacturing equipment.