JP4157111B2 - Tapered steel pipe manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a tapered steel pipe, and in particular, when plastic processing a long steel pipe (pipe) into a tapered steel pipe in a heated atmosphere, improves the accuracy (straightness and surface smoothness) of the product after processing. The present invention relates to a method for manufacturing a tapered steel pipe.

FIG. 3 shows an outline of a tapered steel pipe processing machine for processing a long steel pipe (pipe) into a tapered steel pipe by the apparatus using the squeezing roller previously proposed by the present applicant.
The taper steel pipe processing machine 1 used for manufacturing this taper steel pipe plastically processes a long pipe material W into a taper steel pipe under a heating atmosphere, and includes a traction force addition side rotating mechanism base 2 placed on a frame 4 and The rotary drive force addition side mechanism base 3 placed on the frame 5 and the drawing processing device S and the heating device H disposed between the frames 4 and 5 include the traction force addition side rotation mechanism base 2 and the rotation drive. The force application side mechanism base 3 is provided with travel drive means 2a and 3a, respectively, and is configured to be movable on the frames 4 and 5 in the axial direction. The configuration of the travel drive means 2a, 3a is not particularly limited, but a pinion rotating by a servo motor, a hydraulic motor or the like meshes with racks laid on both the frames 4, 5 to provide a traction force addition side rotating mechanism. It is preferable that the base 2 and the rotational driving force addition side mechanism base 3 be moved.

  A shaft rotation means 3b is disposed on the rotation drive force addition side mechanism base 3 to drive the pipe material W to rotate. The traction force addition side rotation mechanism base 2 may be provided with a rotation means by a synchronous drive control mechanism (not shown), but it is preferably configured to be rotatably supported by a bearing or the like and to be simply driven. .

  The method for manufacturing a tapered steel pipe using the tapered steel pipe processing machine 1 having the above-described configuration is as follows. First, the pipe forming end side of the pipe material W is gripped by the load driving mechanism (not shown) or the rotation drive force addition side mechanism base 3 by hand. Attach to device 7. When the travel drive means 3a moves the rotational drive force addition side mechanism base 3 to the traction force addition side rotation mechanism base 2 and grips the pipe forming start end side of the pipe material W on the traction force addition side rotation mechanism base 2 side, The travel drive means 3a of the drive force addition side mechanism base 3 is stopped, the pipe material W is rotated at high speed by the shaft rotation means 3b, and a tensile force is applied to the left side of the figure by the travel drive means 2a of the traction force addition side rotation mechanism base 2. The drawing roller S of the drawing device S is brought into contact with the peripheral surface of the pipe material W while the steel pipe is sequentially transferred to start contraction (drawing).

When the pipe material W is sequentially transferred by moving the traction force addition side rotation mechanism base 2 by the traveling drive means 2a, a tensile force can be applied to the pipe material W processed by the squeezing roller R. According to experiments by the present inventors, the pipe material W across the traveling drive unit A direction (see FIG. 3 (b)) by 2a of tension about 20t of the traveling drive unit 3a tensile引止force (B direction by When a long steel pipe (pipe) is plastically processed into a tapered steel pipe in a heated atmosphere by applying a drawing force with a force (see FIG. 3 (b)) of about 5 tons, a single operation is good. Plastic working can be performed.
Needless to say, the tensile force and the holding force change in accordance with changes in pipe size, wall thickness, and the like.

The gripping device 7 disposed at the tip of the rotational drive force addition side mechanism base 3 passes through the heating device H, and the vicinity of the gripping device 7 of the pipe material W gripped by the gripping device 7 by the squeezing roller R of the drawing processing device S. When the drawing process is completed, the drawing process ends (see FIG. 3B ), and a tapered steel pipe is manufactured (see, for example, Patent Document 1).

  And, when drawing with this taper steel pipe processing machine 1, as shown in FIG. 4, in order to suppress the heat generation of the drawing roller R that normally contacts the pipe material W, the cooling water is injected from the cooling nozzle V, Only the squeeze roller R was cooled.

However, in this case, although the squeezing roller R is cooled, the Z portion of the tapered steel pipe that has been drawn by the squeezing roller R immediately after the processing is at a high temperature and is applied from the traction force-adding side rotating mechanism base. Depending on the tensile force in the direction, the tapered steel pipe to be processed may have wavy skin or it may be difficult to form a taper steel pipe with a certain thickness, reducing the tensile force applied from the traction force addition side rotating mechanism base. There was a problem that the processing speed could not be increased due to necessity.
JP 2002-292433 A

  In view of the problems of the conventional method for manufacturing a tapered steel pipe, the present invention aims to stabilize the quality of the tapered steel pipe to be processed (suppress the occurrence of wavy skin and improve the straightness), and increase the processing speed. It aims at providing the manufacturing method of the taper steel pipe which can be improved.

In order to achieve the above-mentioned object, the taper steel pipe manufacturing method of the present invention taps the steel pipe by contacting the squeezing roller of the drawing apparatus on the peripheral surface of the steel pipe while heating the steel pipe through the heating device . In a method for manufacturing a tapered steel pipe, wherein a steel pipe portion immediately after being formed by a squeeze roller is tapered while being cooled by cooling water , the cooling water is cooled by a first cooling nozzle disposed on the side of the peripheral surface of the squeezing roller. From the cooling water sprayed toward the area immediately after forming on the steel pipe exit side, and the second cooling nozzle provided on the steel pipe exit side from the final contact point of the squeeze roller for the steel pipe, toward the area immediately after forming on the steel pipe exit side, And it is characterized by performing by the cooling water sprayed so that the injection direction of a cooling water may turn into the direction which opposes on a steel pipe surrounding surface from the said 1st cooling nozzle .

  In this case, the cooling location can be in the range of 1 to 2 times the minimum outer diameter of the formed tube from the final contact location of the squeeze roller to the steel tube toward the exit side of the steel tube.

  Further, in these cases, a cooling water entrainment prevention plate can be disposed in the vicinity of the peripheral surface of the squeeze roller.

According to the method for manufacturing a tapered steel pipe of the present invention, since the steel pipe portion immediately after being formed by the squeezing roller is subjected to taper processing, the high-temperature portion of the tapered steel pipe immediately after processing is cooled, and the traction force addition side rotating mechanism base A taper steel pipe manufacturing method capable of forming a tapered steel pipe having a constant thickness without causing wavy skin in the tapered portion due to the tensile force applied by the traveling drive means can be provided.
And the cooling water which injects cooling with cooling water from the 1st cooling nozzle arrange | positioned to the peripheral surface side of a squeeze roller toward the area immediately after shaping | molding on the steel pipe exit side, and the last contact location of the squeeze roller with respect to a steel pipe From the second cooling nozzle provided on the steel pipe outlet side to the area immediately after forming on the steel pipe outlet side, and the cooling water injection direction on the peripheral surface of the cooling water and the steel pipe injected from the first cooling nozzle By performing with cooling water sprayed so as to face the opposite direction, it is heated by the heating device in the previous stage, and inconvenience that cooling water splashes on the unformed pipe portion that is in a high temperature state and cools the part Can be prevented.

  In addition, when the cooling point is in the range of 1 to 2 times the minimum outer diameter of the formed tube from the final contact point of the squeeze roller to the steel tube toward the exit side of the steel tube, the range of the tapered steel tube immediately after processing is cooled over a wide range. Therefore, it is possible to provide a method of manufacturing a tapered steel pipe with higher straightness by suppressing cooling distortion such as bending and undulation that occurs during the process.

  Further, when the cooling water entrainment prevention plate is disposed in the vicinity of the peripheral surface of the squeeze roller, the peripheral surface of the squeeze roller can be divided into a cooling region R1 and a lubrication region R2, Smooth drawing can be performed while keeping the skin rough.

  Embodiments of a method for manufacturing a tapered steel pipe according to the present invention will be described below with reference to the drawings.

In FIG. 1, the outline of the manufacturing method of the taper steel pipe of this invention is shown.
The tapered steel pipe processing machine 1 used in this method of manufacturing a tapered steel pipe is the same as that proposed by the applicant of the present invention, and the manufacturing method is also a steel pipe ("pipe material W") as shown in FIG. (It is also referred to as)) Applying a tensile force to the left side (steel pipe exit side) and moving the steel pipe in sequence, the drawing roller R of the drawing device S abuts against the peripheral surface of the pipe material W and starts contraction (drawing). To do.

  In the method for manufacturing a tapered steel pipe according to the present invention, the steel pipe portion immediately after the pipe material W is contracted by the drawing roller R of the drawing apparatus S is tapered while being cooled.

According to the experiments by the present inventors, the range of the cooling location in this manufacturing method is the minimum outer diameter of the formed tube from the final contact point P of the squeeze roller R to the steel tube toward the steel tube exit side (left side in the figure). Is intensively cooled by the cooling water sprayed from the cooling nozzles V (V1 and V2) for the forming pipe (forming from the final contact point P of the squeezing roller R to the steel pipe toward the steel pipe exit side). More specifically, when the minimum outer diameter L of the formed tube is 80 mm, the cooling range C is preferably about 100 to 150 mm.
The cooling nozzle V for the forming tube includes a first nozzle group V1 disposed on the side of the peripheral surface of the squeezing roller R, and a second nozzle group V2 disposed in series on the side surface of the squeezing roller R in the steel tube exit direction. It is made up of.
In the illustrated example, the cooling water injection direction of both nozzle groups V1 and V2 is the direction in which the cooling water after injection opposes on the formed pipe. , The amount of the step portion between the peripheral surface of the molded tube and the peripheral surface of the raw tube is small, so that the cooling water splashes on the unformed tube (element tube) heated by the preceding heating device H and being in a high temperature state. And inconvenience of cooling the portion does not occur.
In the case where the formed tube portion immediately after processing is cooled in a wide range (for example, the cooling range C is 400 to 500 mm), the tensile force applied by the traveling drive means 2a can be overcome, and a sufficient processing speed can be ensured, In a place away from the contact point between the squeezing roller R and the pipe material W (the latter half when the cooling range C is set to 400 to 500 mm), cooling distortion (longitudinal warpage) that causes rotational shaking may occur. Absent.

Further, as shown in FIGS. 1A and 1B, the taper steel pipe manufacturing method can be performed by disposing a cooling water entrainment prevention plate 8 in the vicinity of the peripheral surface of the squeeze roller R. It is preferable that the cooling water entrainment prevention plate 8 has a clearance m with the squeezing roller R of about 0.2 to 1 mm.
Thus, the cooling water sprayed from the cooling nozzle V3 that cools the squeezing roller R rides on the circumferential surface of the squeezing roller R that rotates according to the rotating steel pipe, moves in the direction of the arrow Y, and hits the cooling water entrainment prevention plate 8. Since most of the cooling water is scraped off, it is heated by the preceding heating device H and does not cause a temperature drop in the workpiece processing part (unformed pipe part) that is in a high temperature state. Further, the cooling water that has passed through the cooling water entrainment prevention plate 8 serves as a lubricating film to protect the peripheral surface of the squeeze roller R.
The cooling water uses a general grinding / cutting lubricant (coolant) that has a cooling performance lower than that of industrial water, so that only the locations (X1, X2) that collide with the molded pipe are cooled, and the reflected water after the collision. Since it has little influence on the cooling action, it is easy to define the cooling zone. That is, pinpoint cooling is possible. Note that X1 and X2 shown in FIG. 1A are schematically shown in order to facilitate understanding of the shape and position of the cooling water injected from the cooling nozzle on the forming tube.

  As mentioned above, although the manufacturing method of the taper steel pipe of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, In the range which does not deviate from the meaning, the structure is suitably comprised. It can be changed.

  The taper steel pipe manufacturing method of the present invention has a characteristic that the steel pipe portion immediately after forming is cooled by cooling water sprayed from the cooling nozzle, and the taper steel pipe is not deformed by the tensile force applied from the traction force addition side rotating mechanism base. Since it has, it can use for manufacture of a taper steel pipe with a new installation, for example, can also be used by adding a cooling nozzle also in the existing taper steel pipe processing machine.

The cooling state in the manufacturing method of the taper steel pipe of the present invention is shown, (a) is a front view and (b) is a side view. It is a side view which follows the A line of FIG. It is the schematic of the manufacturing method of a taper steel pipe. It is a front view which shows the cooling state with respect to the aperture roller in the manufacturing method of the conventional taper steel pipe.

Explanation of symbols

1 Tapered steel pipe processing machine 8 Cooling water entrainment prevention plate C Cooling range S Drawing machine R Drawing roller H Heating machine W Pipe material (steel pipe)

Claims (3)

  When the steel pipe is heated by passing the heating device and the steel pipe is tapered by contacting the drawing roller of the drawing device on the peripheral surface of the steel pipe, the steel pipe portion immediately after being formed by the drawing roller is cooled by cooling water. In the method of manufacturing a tapered steel pipe to be tapered, the cooling water is jetted from the first cooling nozzle disposed on the side of the peripheral surface of the squeezing roller toward the area immediately after forming on the steel pipe exit side. From the second cooling nozzle provided on the steel pipe outlet side from the final contact point of the squeeze roller with respect to the steel pipe, the injection direction of the cooling water is jetted from the first cooling nozzle toward the region immediately after forming on the steel pipe outlet side. The method for producing a tapered steel pipe is characterized in that the cooling water is injected with cooling water that is jetted so as to be opposed to each other on the circumferential surface of the steel pipe. 2. The method of manufacturing a tapered steel pipe according to claim 1 , wherein the cooling portion is in a range of 1 to 2 times the minimum outer diameter of the formed tube from the final contact point of the squeeze roller to the steel tube toward the outlet side of the steel tube.   3. The method of manufacturing a tapered steel pipe according to claim 1, wherein a cooling water entrainment prevention plate is disposed in the vicinity of the peripheral surface of the squeezing roller.

Images