JP6011241B2 - Tapered segment for UOE steel pipe expansion machine - Google Patents

Description

  The present invention mainly removes the distortion of the welded portion of the welded steel pipe (UOE steel pipe) manufactured by welding the plate end in the pipe axis direction after forming a thick steel plate into a steel pipe shape. It is related with the taper segment of the pipe expansion apparatus (UOE steel pipe expansion machine) used in the pipe expansion process (mainly improving roundness, reducing eccentricity, correcting bending).

  A welded steel pipe manufactured by forming a steel plate and welding the plate end in the tube axis direction has an irregular shape due to distortion or the like that occurs during the forming of the steel plate and during welding. After the steel pipe is welded for the purpose of adjusting this irregular shape, a product is manufactured through a pipe expanding process.

  In welded steel pipes (UOE steel pipes) that are mainly manufactured from thick steel plates, the shape is mainly adjusted by pipe expansion (mainly improving roundness, reducing eccentricity, and correcting bending). In general, UOE steel pipes are generally expanded by about 1% in diameter.

  As an example, a UOE steel pipe expansion machine (hereinafter also simply referred to as “a pipe expansion machine”) 10 used in the UOE steel pipe expansion process is shown in FIG. 1 as a side view and FIG. 2 as a partial enlarged view of FIG. As shown in FIG. 2, the boom 11 that is fixedly disposed, the pull rod 12 that moves in the boom 11 in the longitudinal direction, and the outer peripheral surface that is attached to the tip of the pull rod 12 is tapered in the longitudinal direction. The inner peripheral surface is tapered in the longitudinal direction so as to abut the cone 13 and the outer peripheral surface of the cone 13, and is connected to the tip of the boom 11 via the connecting member 16, so that the pull rod 12 is rearward in the longitudinal direction. Are provided with a taper segment 14 whose diameter is increased by the movement of the cone 13 in the longitudinal direction due to the movement of the cone 13 and a die 15 whose diameter is increased by the expansion of the taper segment 14.

  Thereby, in this pipe expander 10, by pulling the pull rod 12 in the boom 11 backward (rightward in FIG. 1), the cone 13 is pulled backward, and the inner peripheral surface is tapered in the longitudinal direction. The taper segment 14 is expanded, the die 15 outside the taper segment 14 is expanded, and the UOE steel pipe 1 is expanded from the inside to expand.

  Since the taper segment 14 and the die 15 may be integrated, in that case, the integrated segment is referred to as a taper segment.

  When the tube is expanded by the tube expander 10, as shown in FIG. 2, the cone 13 is pulled by the pull rod 12, and the taper segment 14 relatively slides (slids) on the outer peripheral surface of the cone 13 in the longitudinal direction. Therefore, it is preferable from the viewpoint of tube expansion efficiency and the like to reduce the sliding resistance (friction) between the cone 13 and the taper segment 14.

  In order to reduce the sliding resistance (friction) between the cone 13 and the taper segment 14, the following techniques have been proposed.

  That is, Patent Document 1 proposes a method of reducing friction by injecting and applying lubricating oil from an injection nozzle to a sliding surface. Patent Document 2 proposes a method of arranging a wear film at the contact portion between the cone portion and the taper segment portion. Patent Document 3 proposes a method in which the material of the taper segment portion is a material having excellent wear resistance.

JP-A-4-238628 JP 2001-259663 A JP 59-159973 A

  However, when the present inventor investigated the effects of the above prior art (Patent Documents 1 to 3), it was found that the sliding resistance between the cone and the taper segment could not be sufficiently reduced.

  Therefore, as a result of examining the cause, the present inventor has clarified that the following problem occurs between the cone and the taper segment.

  That is, as described above, when the UOE steel pipe 1 is expanded by the tube expander 10, the cone 13 is pulled by the pull rod 12, and the taper segment 14 relatively slides (slids) on the outer peripheral surface of the cone 13 in the longitudinal direction. In this case, as shown in FIGS. 3A and 3B, the corner portion 14a on the inner peripheral surface side of the tip end portion (the bottom surface side of the cone 13) of the tapered segment 14 is the outer periphery of the cone 13. The cone 13 is in strong contact with the surface, and the cone 13 generates heat due to friction at this time. When the cone 13 generates heat, the performance of the lubricating oil on the sliding surface between the cone 13 and the taper segment 14 decreases, seizure occurs on the sliding surface, the friction coefficient increases, and the pulling force of the pull rod 12 ( It becomes necessary to increase (pulling force), and the tube expansion efficiency is reduced.

  On the other hand, the prior art (Patent Documents 1 to 3) reduces the overall sliding resistance between the outer peripheral surface of the cone 13 and the inner peripheral surface of the tapered segment 14, and the above-described cone 13 has little effect on reducing local sliding resistance (contact resistance) between the outer peripheral surface 13 and the inner peripheral surface side corner 14a of the tip of the taper segment 14, and this problem cannot be solved.

  The present invention has been made in view of the circumstances as described above. In the UOE steel pipe expansion machine used when expanding the UOE steel pipe, the outer peripheral surface of the cone and the inner peripheral surface side corner of the tip of the tapered segment are provided. It is an object of the present invention to provide a taper segment for a UOE steel pipe expansion machine that can accurately reduce the local sliding resistance (contact resistance).

  As a result of intensive studies to solve the above problems, the present inventors contacted the cone outer peripheral surface and the taper segment tip by chamfering the inner peripheral surface side corner of the taper segment tip contacting the cone outer periphery. It has been found that the friction when stress (contact resistance) begins to act can be reduced, seizure of the sliding surface can be prevented, and the pipe expansion efficiency can be improved by reducing the frictional force.

  The present invention is based on the above idea and knowledge and has the following features.

  [1] A taper segment for a UOE steel pipe expander that is used in a UOE steel pipe expander used for expanding a UOE steel pipe, and whose inner peripheral surface is tapered in the longitudinal direction so as to contact the outer peripheral surface of the cone. A tapered segment for a UOE steel pipe expansion machine, characterized in that a corner portion on the inner peripheral surface side of the tip portion is chamfered.

  [2] The taper segment for a UOE steel pipe expansion machine as set forth in [1], wherein the chamfer is a round chamfer, and a radius of curvature R is 50 mm to 150 mm.

  [3] A UOE steel pipe expansion machine comprising the taper segment for the UOE steel pipe expansion machine according to [1] or [2].

  According to the present invention, in the UOE steel pipe expansion machine used when expanding the UOE steel pipe, the local sliding resistance (contact resistance) between the outer peripheral surface of the cone and the inner peripheral surface side corner of the tapered segment tip is obtained. It becomes possible to reduce accurately. As a result, seizure of the sliding surface between the cone and the taper segment is prevented, and it becomes unnecessary to increase the pulling force of the pull rod, so that it is possible to improve the tube expansion efficiency, and the cone and taper. The life of the segment can be extended.

It is a side view of a UOE steel pipe expansion machine. It is the elements on larger scale of FIG. It is a figure which shows the conventional taper segment. It is a figure which shows the taper segment which concerns on one Embodiment of this invention. It is a figure which shows cone temperature and pull rod pulling force in the prior art example 1. It is a figure which shows cone temperature and pull rod pulling force in the example 1 of this invention.

  An embodiment of the present invention will be described with reference to the drawings.

  First, the UOE steel pipe expansion machine targeted in the embodiment of the present invention is the UOE steel pipe expansion machine 10 shown in FIGS. 1 and 2 described above. Therefore, description of the structure and structure of the UOE steel pipe expansion machine 10 is omitted here.

  And in one Embodiment of this invention, as shown to Fig.4 (a), (b), the taper segment whose inner peripheral surface is a taper shape in the longitudinal direction so that it may contact | abut to the outer peripheral surface of the cone 13 is shown. 14 is chamfered (round chamfered).

  As a result, in this embodiment, friction when contact stress (contact resistance) starts to act on the outer peripheral surface of the cone 13 and the tip of the tapered segment 14 is reduced, and seizure of the sliding surface between the cone 13 and the tapered segment 14 occurs. As a result, it becomes unnecessary to increase the pulling force of the pull rod 12, so that the tube expansion efficiency can be improved, and the lifetime of the cone 13 and the data segment 14 can be extended.

  As for the rounded chamfering curvature radius R of the inner peripheral surface side corner portion 14a, the effect of chamfering is small when R is extremely small, and conversely, the effect of chamfering is reduced when R is increased to some extent. As a result of examination under various conditions, it was preferable to satisfy 50 mm ≦ R ≦ 150 mm. And the effect of chamfering became the maximum when R = 100 mm.

  In FIGS. 4A and 4B, the chamfering of the inner peripheral surface side corner 14a is a round chamfer, but it may be a chamfer.

  As Example 1 of the present invention, the UOE steel pipe was expanded using the UOE steel pipe expansion machine shown in FIG.

  At that time, as Example 1 of the present invention, the UOE steel pipe was expanded using the tapered segment according to the embodiment of the present invention shown in FIG. In addition, the curvature radius R of the round chamfering in the corner | angular part of the internal peripheral surface side of a taper segment front-end | tip part was 100 mm.

  For comparison, as a conventional example 1, the UOE steel pipe was expanded using the conventional tapered segment shown in FIG.

  The temporal transitions of the cone temperature and pull rod pull force in Conventional Example 1 and Invention Example 1 are shown in FIGS. 5 and 6, respectively.

First, in Conventional Example 1, as shown in FIG. 5, the cone temperature changes at 48 to 80 ° C., and the pull rod pulling force changes at 160 to 210 kgf / cm ² .

On the other hand, in Example 1 of the present invention, as shown in FIG. 6, the cone temperature is lowered to 50 ° C. or lower, and the pulling force of the pull rod is reduced to 98 to 105 kgf / cm ² .

  As a result, in the present invention, it has become clear that the pull rod pulling force can be reduced by suppressing the increase in cone temperature and reducing the frictional force.

  As Example 2 of the present invention, using the UOE steel pipe expansion machine shown in FIG. 1, the outer diameter is 20 to 56 inches (508 to 1422.4 mm), and the tube thickness is 0.5 to 2 inches (12.7 to 50.mm). 8 mm) UOE steel pipe was expanded.

  At that time, as Example 2 of the present invention, the UOE steel pipe was expanded using the tapered segment according to the embodiment of the present invention shown in FIG. In addition, the curvature radius R of the round chamfering in the corner | angular part of the internal peripheral surface side of a taper segment front-end | tip part was 100 mm.

  For comparison, as a conventional example 2, the UOE steel pipe was expanded using the conventional tapered segment shown in FIG.

  As a result, in the conventional example 2, the measurement result of the friction coefficient between the cone and the taper segment was 0.12, and the tube expansion efficiency was 8.2 / hr, whereas in the present invention example 2, The measurement result of the coefficient of friction between the cone and the taper segment was reduced to 0.02, and the tube expansion efficiency was improved to 12.2 lines / hr.

  This confirmed the effectiveness of the present invention.

  The present invention can be widely applied to a pipe expansion facility for welded steel pipes manufactured by welding steel plates.

DESCRIPTION OF SYMBOLS 1 UOE steel pipe 10 UOE steel pipe expansion machine 11 Boom 12 Pull rod 13 Cone 14 Tapered segment 14a Inner peripheral side corner | angular part of taper segment front-end | tip part 15 Dies 16 Connection member

Claims (2)

A taper segment for a UOE steel pipe expander that is used in a UOE steel pipe expander used for expanding a UOE steel pipe, and whose inner peripheral surface is tapered in the longitudinal direction so as to contact the outer peripheral surface of the cone. The corner on the inner peripheral surface side of the tip is chamfered ,
The taper segment for a UOE steel pipe expansion machine , wherein the chamfer is a round chamfer, and a radius of curvature R is 50 mm to 150 mm . A UOE steel pipe expansion machine comprising the taper segment for a UOE steel pipe expansion machine according to claim 1 .

Images