JPS5836410Y2 - Internal seam elimination device for forge-welded pipes - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for erasing the inner seam portion that is generated in a pipe during pipe manufacturing when a forge-welded pipe is made from an upwardly curved skelp.

Normally, the longitudinal cross-sectional shape shown in Fig. 1A is upwardly curled, and the longitudinal cross-sectional shape is shaped like the opening in Fig. A pipe a' is produced, and this pipe a' is continuously subjected to outer diameter drawing with caliber rolls in the drawing process from the third stand onward to produce a forge-welded pipe.

By the way, when producing a forge-welded pipe from the above-mentioned upwardly curled-up skelp a, an inner seam is formed in the pipe a', which is upset and produced in the forge welding process, as shown in the opening of the figure above, and in particular, the inner seam is This caused the occurrence of a depression called a V-notch b' in the seam.

This V-notch b' at the inner seam does not disappear even after the outer diameter is reduced in the subsequent outer diameter drawing process, as shown in Figure C. There remains a flaw b'' after the notch on a'', so even if the forge welded pipe a'' is used as a material tube for a cold drawing pipe, the V-notch b' on the inner seam part remains, regardless of the drawing area reduction ratio. It is difficult to completely eliminate this problem, and it may cause a decrease in processing efficiency (bendability, tube expandability, flatness, etc.) after drawing, and there are strong requests for improvement. be.

For this reason, the production of forge-welded pipes from skelps with a downwardly curled shape has been considered, but in this case, the coil would need to be re-wound, resulting in a significant increase in coil height.

Also, JP-A-49120865, JP-A-50-15
Inventions and ideas such as Japanese Utility Model Publication No. 4890 and Japanese Utility Model Application Publication No. 49-132235 have been made, but in all of these inventions, the main purpose is to reduce the wall thickness of the inner seam of the tube after upsetting and its vicinity. The purpose of this method is to make the pipe uniform, and for this purpose, it is characterized in that the protrusions on the inner surface and seam produced in the produced pipe are reduced by inner roll rolling or cutting with a cutting tool.

However, with such methods and devices, it is pointed out that there are problems such as seizing of the rolling roll, difficulty in dealing with a material having a large ratio of wall thickness to the outer diameter, and technical problems with the cutting tool.

Furthermore, this method requires implementation at the bottom of the roll groove of a caliber roll having a horizontal axis at least from the fourth stand onward, which results in a long mandrel, which causes operational problems.

The present invention has been devised in view of the above, and will be described in detail below with reference to the accompanying drawings starting from FIG. 2 showing one embodiment thereof.

First, Figures 2 and 3 show the relationship between the device of the present invention and a forming/forge welding machine. In each figure, 1 is a forming/forge welding machine, and the forming/forge welding machine 1 is a forming roll of the first stand. 2
, Following the forge welding roll 3 on the second stand, there are more than ten stages of caliber rolls 4, although not shown, from the third stand onwards.
Each is configured as an alternating array of vertical and horizontal axes.

5 is the above-mentioned forming/forge welding machine 1 by means of a feed screw mechanism 6, for example.
The trolley is disposed in front of the forming roll 2 of the first stand so as to be able to reciprocate along the axial direction of the pipe a' to be formed from the skelp a, and a support 7 is erected on the trolley 5. ing.

Reference numeral 8 designates an internally hollow swinging arm having a pivot 9 at the upper end of the support column 7 and supported in the middle so that its tip is located between the forge welding roll 3 of the second stand and the caliber roll 4 of the third stand. At the tip of the swing arm 8, there is a fourth
As shown in FIG. A hollow water cooling plug 10 having a curved surface and a curvature of the convex curved surface when viewed from the front is slightly smaller than the curvature of the inner bottom surface of the tube is integrally provided, and a rear end portion is attached to the hollow water cooling plug 10. A male threaded portion is provided so that the pressing force to be applied can be increased or decreased, and a weight 11 is screwed onto the male threaded portion so as to be variable in position in the axial direction.

Note that the pressing force to be applied to the hollow water cooling plug 10 is 4
For example, if a swing arm with a total length of 1560 mm is supported at a left-right ratio of 1:3.5 by a fulcrum, the weight on the left side of the fulcrum is 1.0 kg, and the weight on the right side is 8.5 kg. The pressing force can be increased or decreased by screwing a 5 kg weight on the left side.

Also, inside the swinging arm 8, there is a water supply pipe 12 that supplies cooling water into the water cooling plug 10, and the swinging arm is held at a predetermined angle to supply lubricating oil to the contact area between the tip of the water cooling plug 10 and the inner seam. The oil supply pipe 14 has a discharge port 13 exposed from the inside to the outside, and is further exposed from the inside to the outside of the swing arm 10 in order to inject spiral flow air in the direction of movement within the formed pipe a'. Each of the injection ports 15 is provided with a predetermined angle with respect to the axial direction and the diametrical direction of the swing arm 10, or an air supply pipe 16 provided with a vane plate (not shown) is inserted into the injection port 15, respectively. are doing.

The cooling water supplied into the water cooling plug 10 by the water supply pipe 12 passes through the swing arm 10 and is discharged from the truck 5 side through a pipe (not shown).

The present invention is constructed in this way, and its operation will be explained next.

First, the feed mechanism 6 moves the truck 5 so that the water-cooled plug 10 provided at the tip of the swing arm 8 is positioned between the forge welding roll 3 of the second stand and the caliber roll 4 of the third stand.

In this state, the upwardly curled-up Skelp a is heated in a heating furnace and extracted, and is led to a forming/forge welding machine 1.
The pipe a' is formed by bending with the forming rolls 2 of the first stand and upsetting with the forge welding rolls 3 of the second stand.

Here, the water cooling plug 10 has a water supply pipe 1 inside it.
It is cooled by the supply of cooling water from 2, and a required moment load is applied using the pivot 9 as a fulcrum by adjusting the weight 11.

Therefore, the inner seam formed in the formed pipe a' is pressed by its own weight in the form of a required moment load when the tip of the water cooling plug 10 comes into contact with it.

At this point, lubricating oil is supplied from the discharge port 13 of the oil supply pipe 14 to the abutment area between the water cooling plug 10 and the inner seam to prevent seizure, and spiral flow air is supplied from the injection port 15 of the air supply pipe 16. The scale is removed from the inner seam portion that occurs when the water cooling plug 10 is pressed by injection.

From this, as shown in Fig. 5A, the inner seam b and the depression called the V-notch b' formed in that part are eliminated as the pipe a' is formed, and this formed pipe a' becomes the third pipe a'.
The outer diameter drawing process is performed using the caliber roll 4 after the stand, and as shown in the opening of the same figure, the forge-welded tube a is completely eliminated without producing any scratches after the V-notch. .

As described above, according to the present invention, when manufacturing a forge-welded pipe from an upwardly curved skelp, the internal seam generated in the pipe during pipe manufacturing is pressed with its own weight of the required moment load of the water cooling plug. , the depression called V-notch that occurs at the inner seam can be easily eliminated with a simple configuration, and the conventional problems can be solved and the coveted forge-welded pipe can be produced, as well as future forge-welded pipes. With the improved strength of the forge-welded part, the processing efficiency after drawing is greatly improved when used as a material pipe for cold drawing pipes, and the range of application can be further expanded.

[Brief explanation of drawings]

Figure 1 shows the progress of the material; Figure A is a vertical cross-sectional view showing the upwardly curved skeleton, the opening of the figure is a vertical cross-sectional view showing the state of the pipe that was made at that time, and Figure C is a vertical cross-sectional view showing the situation of the pipe that was made at that time. A vertical cross-sectional view of a forge-welded pipe produced in the same manner, FIG. 2 is a perspective view showing the state in which the erasing device according to the present invention is used, FIG. Fig. 5 is an enlarged view of the section, A is a vertical cross-sectional front view, the mouth is an end view of the water-cooled plug, Fig. 5 shows the state of the pipe according to the present invention, and Fig. A is a longitudinal cross-sectional view of the pipe during pipe production. The opening in the figure is a longitudinal sectional view of a forge-welded pipe. a is an upwardly curled scalp, a' is a tube, a'' is a forge-welded tube, b is an inner seam, b' is a V-notch, 1 is a forming/forge welding machine, 2 is a forming roll of the first stand, 3 is a 2 stand forge welding rolls, 4 a caliber roll of the third stand, 5 a truck, 7 a support, 8 a swing arm, 9 a pivot, 10 a water cooling plug, 12 a water supply pipe, 14 an oil supply pipe,
16 is an air supply pipe.

Claims (1)

[Scope of utility model registration request] In a forge-welded pipe manufacturing apparatus that manufactures a pipe while performing an outer diameter drawing process on a pipe formed from an upwardly curled-up skeleton through a forge-welding process, the pipe is located in front of the forming roll of the first stand, and A dolly is installed so that it can run along the axial direction of the dolly, and the rear half of the dolly is pivoted on a pillar installed on the dolly so that it can swing vertically. Its tip is bent downward to suppress and eliminate the uneven streaks generated on the part, and the shape of its lower end surface exhibits a convex curved surface in front view and side view, and the convex curved surface curvature in front view is the same as the inner bottom curvature of the forge-welded pipe. A hollow water-cooled plug is provided, and the rear end is provided with a weight whose position is variable in the axial direction to increase or decrease the pressing force to be applied to the water-cooled plug. A swing arm, a water supply pipe that is inserted into the swing arm and supplies cooling water into the water cooling plug, and an oil supply pipe that supplies lubricating oil to the contact portion between the water cooling plug and the inner seam portion. is equipped with an air supply pipe that injects spiral flow air into the pipe, and the uneven seam on the inner bottom surface of the pipe is fixed between the forge weld roll of the second stand and the first squeeze roll of the third stand in the pipe. An inner seam erasing device for a forge-welded pipe, characterized in that the inner seam erasing device for a forge-welded pipe is constructed to erase the inner seam by pressing the water-cooled plug into contact with the positioned water cooling plug.