JP5831195B2 - Hollow shell support device and method for seamless steel pipe manufacturing - Google Patents

Description

  The present invention relates to a hollow shell support method and apparatus in the production of seamless steel pipes, and in particular, disposed on the exit side of a pipe rolling machine such as a piercer or an elongator or a polishing pipe machine in a seamless steel pipe production facility, A bar (mandrel bar used for a drilling machine or a plug bar used for a pipe rolling machine) inserted in the center of the cross section of the workpiece and an outer surface side of a hollow shell that passes through the bar are alternately supported (restrained). The present invention relates to a hollow shell support device and a support method in seamless steel pipe manufacturing.

Patent Document 1 describes the following points.
FIG. 5 is a schematic layout example of a general layout in an inclined roll punch. In the figure, 31 is an inclined roll, 21 to 23 are support rolls, 24 is a thrust receiver, 25 is a mandrel bar, 26 to 28 is a hollow shell detector, 32 is a drilled plug, 29 is a billet before drilling, 30 is a hollow shell being drilled Is shown in section, and the hollow shell is extended in the direction of the arrow. As shown in the figure, the support roll consists of three rotatable rolls in order to prevent the long mandrel bar 25 to support the thrust load received by the drilling plug to prevent buckling deformation due to the thrust load. When a plurality of devices (commonly called bursteadia) are installed on the rear surface of the drilling machine, and the hollow shells that are stretched while swinging violently by the drilling machine approach each support roll while holding the outer diameter of the mandrel bar by each supporting device The detector detects the approach to support the hollow shell by fixing the distance between the three rolls to the position of the preset shell position [1] that does not interfere with the passage of the hollow shell. Is going.

It is well known that the hollow shell runout affects the uneven thickness of the hollow shell in such an inclined roll type drilling method. Therefore, in the shell position SP1 when passing through the hollow shell, the roll position of the support roll is set to the outer diameter of the hollow shell. It is advisable to approach the hollow shell, but the hollow shell has a mandrel bar as a mandrel because the inner diameter d _{1 of the} hollow shell and the outer diameter D ₂ of the mandrel bar have a relationship of d ₁ > D _2. It is distracted while swinging.

  For this reason, in order for the hollow shell head to pass the support roll without hindrance, the interval between the three rolls at the shell position [1] is set larger than the outer diameter of the hollow shell in consideration of the amount of deflection of the hollow shell. In particular, because of the restriction of the connection with the punch frame, the distance L1 between the punch and the first stage support device and the support device distance L2 after the first stage are L1> L2, and the influence of the shake of the hollow shell is large. The roll interval at the shell position [1] of the first stage burstedia is set from the outer diameter of the hollow shell +5 mm to +10 mm, which is larger than that after the second stage, and the effect of suppressing the shake of the hollow shell is small.

  As a method for solving such a problem, the methods proposed in Patent Document 2 and Patent Document 3, that is, when the hollow shell head approaches the support roll, the distance between the three rolls is once separated to a position larger than the outer diameter of the hollow shell. After the hollow shell head has passed through the support roll, a method has been proposed in which the distance between the three support rolls is reduced until a constant pressing force is obtained on the hollow shell, and the hollow shell is pressed and clamped.

  According to the methods proposed in Patent Document 2 and Patent Document 3, the hollow shell is pressed and clamped by the support roll, so that the hollow shell that travels with rotation always overcomes the braking force by the support roll composed of three cylindrical rolls. Therefore, it is inevitable that slip always occurs between the hollow shell and the support roll. For this reason, it has become a cause of occurrence of seizure of the support roll and outer surface flaws of the hollow shell.

Further, if the holding force of the hollow shell support roll increases, a further braking force is applied to the advance of the hollow shell, and the outer diameter of the hollow shell expands abnormally on the front side of the roll, causing a problem that the hollow shell cannot pass through the support roll and cannot be drilled. There was a problem such as.
In Patent Document 1, as a means for solving the above-mentioned problems and suppressing vibration of the hollow shell easily and effectively, (a) until the end of the hollow shell side approaches the support roll of the support device, the support device Holding the mandrel, (b) immediately before the end of the hollow shell passes through the support roll of the support device, the support roll interval is opened to an interval where the end of the hollow shell does not collide, and (c) the end of the hollow shell is After passing through the support roll of the equipment, the opening of the support roll is larger than the outer diameter of the hollow shell, and the hollow shell vibration during tightening rolling is suppressed until the distance between the support roll and the hollow shell is 5% or less of the outer diameter of the hollow shell. Hollow shell support method, and apparatus for carrying out the method, support during the stroke Proposes a holding or adjustable and the hollow shell support device open Lumpur.

  In the support roll opening adjustment method described in Patent Document 1, the first and second cylinders are used, the first cylinder drives opening and closing of the top roll of the three support rolls, and the second cylinder is used. The other two rolls are driven to open and close, and a predetermined amount of oil is fed into these cylinders to adjust the distance between the support roll and the hollow shell linked to the cylinders. In order to perform the insertion operation, a certain amount of hydraulic oil discharged by a hydraulic discharger whose piston stroke is adjusted in advance is introduced to the rod side of the second cylinder.

JP 7-328707 A Japanese Patent Laid-Open No. 2-80108 Japanese Utility Model Publication No. 7-18408 (Japanese Utility Model Publication No. 3-42301)

  However, in the technique of Patent Document 1, since the amount of oil fed into the cylinder is constant, the opening / closing stroke of the support roll in the hollow shell restraint mode cannot be changed. Therefore, the balance between the support roll and hollow shell clearance <1> when passing through the hollow shell and the balance between the support roll and hollow shell <2> when restraining the hollow shell cannot be changed, and there is a problem that the adjustment to the optimal setting remains. there were. If the stroke is designed too short, there may be a problem with the hollow shell being struck by Bursteadia. If the stroke is designed too long, the time until the hollow shell restraint is completed becomes longer, and the effect of reducing uneven thickness is weakened.

The present invention has been made to solve the above problems, and the gist of the present invention is as follows.
(1)
A hollow shell support device in the production of seamless steel pipes that alternately supports a bar for piercing or rolling and a hollow shell passing through the bar on the outlet side of a piercing machine or a pipe rolling mill of a seamless steel pipe manufacturing facility. The three rotatable rolls surrounding the outer periphery of the supported material are connected to one arm via a link mechanism, and the rod of the first hydraulic cylinder is connected to the end of the arm on the side opposite to the link mechanism. A seamless steel pipe manufacture comprising a second hydraulic cylinder attached to an intermediate part of an arm length via a liner, and a worm jack arranged to abut the rod tip of the second hydraulic cylinder outside the arm. Hollow shell support device.
(2)
Using the hollow shell support device described in (1) above, a bar for piercing or pipe rolling and a hollow shell passing through the bar are supported on the exit side of the piercing machine or the pipe rolling mill of the seamless steel pipe manufacturing facility. A hollow shell support method in the manufacture of seamless steel pipes, wherein the three rolls are pressed against the bar by the first hydraulic cylinder while the hollow shell is approaching the roll of the hollow shell support device, and immediately before the end of the hollow shell arrives. , said first hydraulic cylinder Delo Lumpur opening switched to the first roll opening of hollow shell outside isoparametric, immediately after the tip passes through the hollow shell, the hollow shell outer diameter of the roll opening at the second hydraulic cylinder By switching to a second roll opening that is greater than and less than the first roll opening, and changing the thickness of the liner according to the change in the outer diameter of the hollow shell Hollow shell support method in seamless steel pipe production, characterized by changing the 2 roll opening.

  According to the present invention, the opening / closing stroke of the support roll in the hollow shell restraint mode (which is the difference between the first roll opening and the second roll opening) can be changed, and the optimum roll opening can be set. Thus, the uneven thickness of the seamless steel pipe can be reduced.

It is a schematic diagram which shows one example (roll opening degree setting step) of embodiment of this invention. It is a schematic diagram which shows one example (bar restraint mode) of embodiment of this invention. It is a mimetic diagram showing one example (hollow shell tip passage mode) of an embodiment of the present invention. It is a schematic diagram which shows one example (hollow shell restraint mode) of embodiment of this invention. It is a typical layout schematic diagram example in an inclined roll type punch.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 4 are schematic views showing different states of roll opening degrees in an example of an embodiment of the present invention. In common with these drawings, the hollow shell support device of the present invention is a supported material. Three rotatable rolls (support rolls) 1, 2, and 3 that surround the outer periphery of a certain bar 10 and hollow shell 11 are connected to one arm 5 via a link mechanism 4, and the side of the arm 5 opposite to the link mechanism The rod end of the first hydraulic cylinder 6 is connected to the end of the first hydraulic cylinder 6, the second hydraulic cylinder 7 is attached to the middle part of the arm 5 via the liner 9, and the second hydraulic cylinder 7 is mounted outside the arm 5. A worm jack 8 that is brought into contact with the rod tip is arranged.

  Here, the link mechanism 4 is pivotally supported by the support shaft 52 at the extension start point of the lever 53 extending from both ends of the arm 5 to the both sides, the roll 3 is connected to the tip of the lever 53, and the hinge portion is connected to the rear end of the lever 53. 50, the intermediate point of the length of the lever 47 is pivotally supported by the support shaft 46, the roll 2 is connected to the tip of the lever 47, the hinge portion 48 is provided at the rear end of the lever 47, and the hinge portion 48 and the hinge portion 50 are It is connected by a connecting material 49, the intermediate point of the lever 42 is supported by a support shaft 41, the roll 1 is connected to the tip of the lever 42, the hinge part 43 is provided at the rear end of the lever 42, and the arm 5 is supported. A hinge portion 45 is provided at an intermediate point between the end on the shaft 52 side and the mounting portion of the second hydraulic cylinder 7, and the hinge portion 45 and the hinge portion 43 are connected by a connecting member 44. Therefore, by rotating the arm 5 around the support shaft 52, the roll opening degree of the rolls 1, 2, and 3 can be changed via the link mechanism 4.

  FIG. 1 shows the stage of insertion of the bar 10 and setting of the roll opening. The setting of the first roll opening for passing the hollow shell tip without colliding with the roll is performed by moving the rod of the second hydraulic cylinder 7 backward. The rod of the first hydraulic cylinder 6 is moved forward, the rear end of the arm 5 is pushed down, the rod tip of the second hydraulic cylinder 7 is brought into contact with the head of the worm jack 8, and the head of the worm jack 8 in this state This is done by positioning. Next, the setting of the second roll opening degree for suppressing the excessive swinging of the hollow shell is performed by changing the rod of the second hydraulic cylinder 7 to the forward limit and determining the thickness of the liner 9 (the liner 9 is configured). This is done by determining the number of shims in the shim stack. The setting of the second roll opening is easy and can be easily changed. The roll opening degree is represented by the diameter of a circle circumscribed by the three rolls. The first roll opening is larger than the outer diameter of the hollow shell, and is preferably about the outer diameter of the hollow shell + (20 to 30) mm. The second roll opening is greater than the hollow shell outer diameter and less than the first roll opening.

FIG. 2 is a stage in which the hollow shell 11 is approaching the rolls 1, 2, and 3, and the rolls 1, 2, and 3 are in the bar restraint mode. That is, the rod of the second hydraulic cylinder 7 is set to the retreat limit, the rod of the first hydraulic cylinder 6 is retracted, the rear end of the arm 5 is pulled up, and the rolls 1, 2, and 3 are pressed against the bar 10.
FIG. 3 shows a stage from immediately before the tip of the hollow shell 11 arrives to the rolls 1, 2 and 3 until immediately after it passes, and the rolls 1, 2 and 3 are set to the hollow shell tip passing mode. That is, immediately before the end of the hollow shell 11 arrives, the rod of the first hydraulic cylinder 6 is advanced, the rear end of the arm 5 is pushed down, and the rod tip of the second hydraulic cylinder 7 is brought into contact with the head of the worm jack 8, Switch to 1 roll opening.

  FIG. 4 shows a stage from immediately after the front end of the hollow shell 11 passes through the rolls 1, 2, 3 until the rear end has passed, and the rolls 1, 2, 3 are set in the hollow shell restraint mode. That is, immediately after passing through the tip of the hollow shell 11, the pressure of the first hydraulic cylinder 6 is lowered (weakly opened), then the rod of the second hydraulic cylinder 7 is shifted to the forward limit, and the second hydraulic cylinder 7 of the arm 5 is moved. By pushing up the attachment portion, the second roll opening degree is switched.

The arrival and passage of the hollow shell tip is detected by detectors installed on the entry side and exit side of rolls 1, 2, 3, and the detection signal of the entry side detector is used to switch from the bar restraint mode to the hollow shell tip passage mode. Switching is performed to switch from the hollow shell tip passing mode to the hollow shell restraint mode using the detection signal of the detector on the exit side.
Thus, according to the present invention, the setting of the second roll opening is easy and can be easily changed, and the balance with the first roll opening can be optimized. Uneven thickness can be effectively suppressed.

  The present invention was applied to the exit side of a drilling machine in a seamless steel pipe production line in the above-described embodiment, and was taken as an example. The hollow shell support device was arranged in three stages in the longitudinal direction of the bar. The conventional example in the same line is an apparatus configuration in which the second hydraulic cylinder is removed in the above-described embodiment, and the bar restraint mode, the hollow shell tip passing mode, and the hollow shell restraint mode are set only by stroke control of the first hydraulic cylinder. Although it is to achieve each, the stability of the rod between the stroke upper and lower limits is difficult, and the roll opening fluctuates, so the uneven thickness ratio of the hollow shell rear end {= (maximum thickness-minimum thickness) (Thickness) / average wall thickness × 100 (%)} was about 12%. On the other hand, in the examples, the thickness deviation rate in the same part was significantly reduced to 4%, and a large thickness deviation suppression effect was recognized.

1,2,3 roll (support roll)
4 Link mechanism
5 arm
6 First hydraulic cylinder
7 Second hydraulic cylinder
8 Warm jack
9 liner
10 bar
11 Hollow shell
21 First stage support device
22 Second stage support device
23 Third stage support device
24 Thrust receiver
25 Mandrel bar
26, 27, 28 detector
29 Billet before drilling
30 Hollow shell during drilling
31 perforating roll
32 perforated plug
41, 46, 52
42,47,53 lever
43, 45, 48, 50 Hinge
44,49 Tie

Claims (2)

  A hollow shell support device in the production of seamless steel pipes that alternately supports a bar for piercing or rolling and a hollow shell passing through the bar on the outlet side of a piercing machine or a pipe rolling mill of a seamless steel pipe manufacturing facility. The three rotatable rolls surrounding the outer periphery of the supported material are connected to one arm via a link mechanism, and the rod of the first hydraulic cylinder is connected to the end of the arm on the side opposite to the link mechanism. A seamless steel pipe manufacture comprising a second hydraulic cylinder attached to an intermediate part of an arm length via a liner, and a worm jack arranged to abut the rod tip of the second hydraulic cylinder outside the arm. Hollow shell support device. A seam that uses the hollow shell support device according to claim 1 to support a piercing or pipe rolling bar and a hollow shell passing through the bar on the exit side of a piercing machine or a pipe rolling machine of a seamless steel pipe manufacturing facility. A hollow shell support method in steel-free pipe manufacturing, wherein the three hydraulic rolls are pressed against the bar by the first hydraulic cylinder during the approach of the hollow shell to the roll of the hollow shell support device, and immediately before the end of the hollow shell arrives. wherein the first hydraulic cylinder Delo Lumpur opening switched to the first roll opening of hollow shell outside isoparametric, immediately after the tip passes through the hollow shell, the second hollow shell of the roll opening at the hydraulic cylinder out of isoparametric And by switching to a second roll opening less than the first roll opening, and changing the thickness of the liner according to the change of the outer diameter of the hollow shell, Hollow shell support method in seamless steel pipe production, characterized in that to change the roll angle.

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