JPS6228112A - Cutting method for pipe in seam welded pipe manufacturing equipment - Google Patents

Abstract

PURPOSE:To obtain a good cut port portion, by forming a cut over the whole periphery of a material pipe in a cut position of the seam welded pipe and restricting a movement of the pipe in its upstream side while giving a rapid movement to the cut direction from the downstream side so as to break a part of the cut. CONSTITUTION:The cutting method forms in the cut position of a material pipe A a two-stage V-shaped cut B of predetermined depth by a cutting machine over the whole periphery of the pipe. The method, restricting the upstream side of the cut B by a clamp, applies rapid pressing toward the cut B by a press from the downstream side of the cut B. Shearing force acts in the vicinity of the cut B, but the pipe A, concentrating stress in a part of the cut B by a cut effect, is broken in the cut B.

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.

[Prior art 1] Cutting devices used in ERW pipe manufacturing equipment must perform running cutting, in which cutting is performed while moving along with the pipe that is continuously fed out. becomes. Conventional cutting methods that satisfy this premise include a method of friction cutting by rotating a saw blade (7-wheel saw) at high angles, a method of swinging down a blade built into a guiset, and cutting off 17 blades 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 pipe and cut by cutting (however, only for 'W' round pipes), a cutting method using a plasma arc, etc. has been adopted.

[Problem 1 to be Solved by the Invention] Each of the conventional cutting methods described above has a problem in that the vicinity of the cutting opening is deformed or burrs and burrs occur at the cutting opening. For example, in the Guiset method, there is no lower blade in the upper part of the pipe cross section and the cutter is simply used to pierce the pipe, so deformation is large, especially in the case of square pipes.Furthermore, burrs occur.Rotary disk In the case of cutters, the burrs are large.7 In the case of traction saws and plasma arc cutting, deformation is not so much of a problem, but the occurrence of burrs is significant.

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

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 methods other than the Guiset method, it is desirable to be able to cut in an even shorter time.

This invention is an attempt to solve the above-mentioned conventional problem 7α, and eliminates deformation, burrs, and burrs at the cut end.
Another object of the present invention is to obtain a method for cutting a tube in an electric resistance welded tube manufacturing facility that can cut the tube in a short time.

[Means for solving the problem α] In this invention, in order to solve the above problem, ?
T! After sewing welding and before passing through the signing roll, a notch is formed around the entire circumference of the raw pipe at the position where it should be cut, and a sizing roll adds Rikusilane to make it into a perfect circle with a predetermined shape and size. After the tube is made into a round or square tube, the upstream side of the cut position of the tube restricts movement in the tube cross-sectional direction, and the downstream side restricts movement in the tube cross-sectional direction.
The cut portion was to be broken by pushing it hard.

[Effect] When the upstream side of the notch position of the pipe is restrained and the downstream side is forcefully pushed, shearing force acts near the notch, but the stress is concentrated at the notch due to the notch effect, and the stress is concentrated at the notch. The tube is cut.

[Embodiment 1] An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

Figure f51 is a side view of the entire ERW steel pipe manufacturing equipment to which the cutting method of the present invention is applied. A coiled hot rolled steel strip 2 supported by an uncoiler 1 is sent out by pinch rolls 3,
The material is flattened by the leveler 4, and the rear end of the previous coil and the tip of the next fill are welded together by the shear 5 and the end of the next fill, and during this welding connection, the material is supplied to the pipe making machine. After passing through the underground Loopa 7 to maintain
It is sent to breakdown roll 8 of the pipe making machine. In this breakdown roll 8, the selvedge is formed into a semicircular shape, and then formed into a substantially circular shape by the subsequent fin bath roll 9, and the second part is electric resistance welded using a high frequency resistance (or induction) welding margin 10, and this welded portion is The fillet of the tube is removed by a bead trimmer 11, and a round blank tube is thus obtained. In addition, 12 is a cooling table for cooling the welding part by pouring cooling oil;
3 is a sizing roll that adds liguxilan to the round raw tube and forms it into a perfect round tube or square tube of a predetermined shape and size; 14 is a Turkshenodrol that corrects warpage, bending, and twisting of the tube; 15 is a cutting roll; This is a runout table for sending out finished products, and the above configuration is the same as the conventional one.

Conventionally, a cutting machine is only installed on the downstream side (right side in the figure) of the Turk's Radroll 14, but in the present invention, a cutting machine is installed on the upstream side of the sizing roll 13 on the outer periphery of the round blank tube at the position to be cut. A traveling type cutting machine 16 is installed to form a cut all around the circumference, and on the downstream side of the Turkshead Rolt 1, the upstream side of the cutting position of the pipe restricts movement in the cross-sectional direction of the pipe, and the downstream side is A cutting machine 17 is installed that sharply pushes in the cross-sectional direction of the tube to break the cut portion.

In addition, in the embodiment, in order to easily keep the depth of the cut by the motherboard 16 constant over the entire circumference, a welded round blank pipe is placed on the upstream side of the cooling table 12. A brace sizing roll 18 is installed to make the ball into a roughly perfect circle. Note that this presizing roll 18 is
The sizing roll 13 for obtaining a predetermined shape and dimension is a 5% roll, and the size is not an issue and is simply for obtaining an approximate perfect circle. Therefore, the tube immediately after leaving the presizing roll 18 is also referred to as a round blank tube.

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

FIG. rjS2 shows a rotary disc cutter showing an example of the above-mentioned cutting surface 16. One rotary disc cutter has, for example, three circular blades 20 with sharp outer edges.
Each circular blade 20 is rotated in the circumferential direction around the round blank tube A by driving the drive device 21 and narrowed, thereby making a cut to a predetermined depth on the outer periphery of the blank tube A. Incidentally, one rotary peep cutter grips the raw pipe A with a clamp (not shown), and forms the above-mentioned incision while traveling together with the raw pipe A. Other types of cutting tools include rotary bit counters with rotating bits, and various R-shaped cutting tools used for cutting round pipes. Precepts can be used.

An example of the depth and shape of the cut formed by the cut groove 16 is shown in FIG. 3 and FIG. 4, which is an enlarged view of part A of FIG. 53. The depth 11 of the cut B is such that it does not break during the sizing process in which it passes through the sizing roll 13, and
The optimum depth is set so that the cut surface does not deform during cutting. , the shape of the cut B is ＼l shape or the fourth shape.
As shown in the figure, in order to reduce the wear of the blade, it is recommended to use a two-stage shape with a large inclination angle at the tip. In the illustrated example, one side of the tip is sloped at 75° and the other side is sloped at 15°.

An example of the press cutting machine 17 will be explained with reference to FIG. 5 and FIG.
2I), a goose set 23 is provided so as to be slidable in the feeding direction of the tube, and on the base 23a side of this goose set 23,
Clamp 2 that grips only the tube on the product fixed side in front of the tube feeding direction
4. A tube restraining member 2G having a hole shape through which the tube passes and restraining the movement of the tube in the cross-sectional direction; and a slide holder 27
A slide 28 is mounted on the tube restraining member 26 side of the slide holder 27 to apply a pushing force to the hole-shaped holding tube through which the tube passes. A spring 29 is provided to return the slide 28, and on the other hand,
The movable base 23b of the guide set 23 has the slide 28
A tilted hammer 30 for hitting is fixed.

To explain the timing of making a cut with the cutting machine 16 and cutting with the push-cut cutting machine 17, the timing of making a cut with the cutting machine 16 and cutting with the push-cut cutting machine 17 will be explained. [Each time it is detected by a measuring roll or the like that the pipe has been fed by @, the cut allowance 16 is activated to form a cut, and for cutting, a cut detection 2'' is attached to the push cutter 17. , the clamp 24 is activated by the signal of the notch passage detection by this notch detector.
The notch B connects the pipe restraining member 26 and the slide 2.
When the pipe is placed between the press body 8 and the ram 221 of the press body 22, the ram 221 of the press body 22 is rotated seven times.

The cut detector may be a mechanical method of mechanically detecting the cut using a detector in contact with the tube, a method of detecting the cut using reflection of light, or an eddy current flaw detection, an ultrasonic flaw detection, or a method of detecting a change in the amount of perforation by electromagnetic testing. It is advisable to adopt the most suitable method, such as an electrical method of detection using techniques such as .

In the above-mentioned electric resistance welded steel pipe manufacturing equipment, the welded round blank pipe is welded in step 10. After removing excess thickness with a bead Y rimmer 11, it is made into a roughly perfect circle by a presizing roll 18, and then placed on a cooling table. 12, a cut B is made at a predetermined position by a cut rock 16 over the entire circumference, and then a perfect round tube or a square tube with a predetermined shape and dimensions is formed by a sizing roll 13, and bent etc. are removed by a Turk's head 14. be corrected. After leaving the Rad 14 to Turks, the clamp 24 of the push cutter 17 is actuated by the signal from the cut detector and grips the front and back of the cut part of the pipe, and the Guicent 23 moves forward with the pipe, and then the press body 22
The ram 22b lowers and slides 2 at the inclined handle 7-30.
8, and the downstream side of the notch in the pipe is this slide 28.
is rapidly pushed down. Since the upstream side of the notch is restrained, shearing force acts near the notch, but stress is concentrated at the notch due to the notch effect, so the pipe is broken at the notch B.

After breaking, when the chucks 22 and 23 are released, the product cut to a predetermined thickness is sent out through the run-out table 15.

There are various conditions to obtain a good cutting edge.
Cut depth h, shape, tube freezing member 26 and slide 28
The distance between the slide 28, the inclination angle θ of the push by the slide 28, the speed of the push of the slide 28, and others are shadows! Shi, furthermore,
It varies depending on the material, plate thickness, whether it is a round or square tube, its size, etc. These settings may be determined by experiment. The inclination angle θ is suitably about 45°, but preferably within the range of at least 15° to 75° in order to avoid large deformation. Note that in the case of a round tube, the inclination angle θ is irrelevant.

Although the present invention can be applied to both round tubes and square tubes, the advantages of -S are best utilized 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 notch is formed in a round shape, there is no disadvantage at all, and at the cutting stage, the shape is simply pressed down, so the square shape is not a disadvantage at all. During corner forming using the sizing rolls 13, the greatest stress is applied to some corners of the square, and the corners are more likely to break than the side parts, so the square tube is cut by force-cutting. It is convenient for doing so.

In the embodiment, the clamp for gripping the tube and the tube restraining member 26, slide 28, and slide holder 27 for pushing the tube are separated, but the clamp that grips the rear part of the notch is also used to push down only the downstream side. It is also possible to have the structure of

[Effects of the Invention] According to the method of the present invention described above, a cut is formed in the pipe in front of the sizing roll, and after passing through the sizing roll, the upstream side of the cut part restricts movement in the cross-sectional direction of the pipe, and the downstream side Since the pipe is cut by rapidly pushing it in the cross-sectional direction of the pipe, it has various excellent effects as follows.

(i) Unlike the conventional methods, deformation of the cut O part,
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.

(ii) Since the method applies shear force to the pipe to break it, it is possible to cut the weld in a shorter time than with conventional rotary disc cutters, 7-way saws, plasma arc cutting methods, etc., and the time required for cutting is reduced. There are many cases where the pipe production speed has to be reduced due to restrictions on the pipe production speed. It was stomach.

(iii) Unlike the conventional guiscent method with a cutter, no chips are generated, which improves material yield and eliminates downtime for scrap disposal. sex has improved.

(iv) Unlike cutting with a 7-wheel saw, no high level of noise is generated which could be a problem.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of the electric R 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 Pt54 is the f52 figure. FIG. 5 is a side view of the main part of the push-cut cutting machine, and FIG. 6 is a front view of the main part.

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 upstream side of the cut position of the tube restricts movement in the tube cross-sectional direction, and the downstream side is sharply pushed in the tube cross-sectional direction to break the cut portion. A method for cutting pipes in ERW pipe manufacturing equipment.