JP3348664B2 - Perforated rolling mill and method for extracting perforated shell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a perforated rolling mill for seamless steel pipes and a method for pulling out a perforated shell used in this rolling mill. The present invention relates to a piercing and rolling mill and a method for extracting a piercing shell for a small-quantity multi-product production of a seamless steel pipe from a small diameter to a large diameter in a pipe manufacturing dimension.

[0002]

2. Description of the Related Art As a method for producing a seamless steel pipe by hot,
The so-called Mannesmann pipe manufacturing method is widely used. In this pipe making method, a solid round billet heated to a predetermined temperature is used as a material to be rolled, and the material to be rolled is fed to a piercing mill (a so-called piercer) to pierce the axial center thereof, The shell which is a hollow shell is manufactured. Next, the perforated shell is passed through an elongator having the same configuration as that of the above-described piercing and rolling mill as it is, or after the piercing shell is subjected to diameter expansion and thinning, and then fed to a subsequent drawing and rolling machine such as a plug mill or a mandrel mill. And stretch-roll. After that, it passes through a stretch reducer, a reeler, a sizer or the like, and then undergoes a polishing process for modifying the shape and performing sizing.

FIG. 1 is a view for explaining the state of piercing of a material to be rolled in a piercing mill. The perforating rolls 1 are axially symmetrically arranged in pairs so as to form a predetermined crossing angle and a predetermined inclination angle with respect to a pass line XX which is a movement axis of the material 3 to be rolled in the rolling direction. In the piercing mill in which the piercing roll 1 is configured as described above, the material to be rolled 3 fed on the pass line XX in the outline arrow direction is bitten between the piercing rolls 1. After that, it moves on the pass line while turning, and a hole is made in its axial center by the plug 2 to form a perforated shell 4 which is a hollow shell. During this time, the plug 2
It is supported by a core metal 5 held by a thrust block (not shown) so as to be located between the perforating rolls 1 along a pass line. After the piercing and rolling is completed, the plug and the cored bar are extracted from the inner surface of the pierced shell at the exit side of the piercing mill, and the pierced shell as a single piece is transported to the next step.

FIG. 2 is a view for explaining a step of pulling out a perforated shell on the exit side of a piercing mill after piercing and rolling. Same figure
(a) shows a state in which the piercing shell is restrained by the pull-out stopper 7 after piercing and rolling is completed, and (b) shows a state in which the plug 2 and the core metal 5 are pulled out from the piercing shell 4.
As shown in FIG. 2, a pair of piercing rolls 1 are arranged around the pass line XX, and the plug 2 is supported by the cored bar 5 so as to be located between these piercing rolls 1. Further, the metal core 5 supporting the plug 2 is held by a thrust block 6.

[0005] After the piercing and rolling is completed, the thrust block 6 holding the plug and the core metal has moved to the forward position. Thereafter, by retreating the thrust block 6, the perforated shell 4 comes into contact with the pull-out stopper 7, and its movement in the pass line direction is restricted. In this state, when the thrust block 6 is further moved to the retracted position, the plug 2 and the core metal 5 can be pulled out from the inner surface of the perforated shell 4 as shown in FIG. Next, the plug 2 and the core metal 5 are pulled out, and the perforated shell 4 as a single body is transported to the next step.

FIG. 3 is a view showing the structure of a conventional stopper 7 for pulling out a perforated shell. A U-shaped guide 8 is used as the pull-out stopper 7, and is configured to be attached to the guide body 9. The groove width D of the U-shaped groove formed in the U-shaped guide 8 is larger than the outer diameter of the plug and the cored bar, but smaller than the outer diameter of the perforated shell. Therefore, when the thrust block is retracted with the completion of the piercing and rolling, the plug and the core metal pass through the U-shaped groove of the U-shaped guide 8, but only the piercing shell moves backward in the pass line direction by the U-shaped groove. Restrained, the plug and core are pulled out of the inner surface of the perforated shell.

At this time, in order to effectively pull out the plug and the core from the perforated shell, the gap between the groove width D of the U-shaped groove of the U-shaped guide 8, the outer diameter of the plug and the core, and the outer diameter of the perforated shell is required. Must be kept within a certain range. For this reason, when the plug and the cored bar are exchanged due to the change of the pipe making, the U-shaped guide 8 needs to be exchanged each time.

However, replacement of the conventional U-shaped guide has been performed manually by arranging a jib crane or the like on the exit side of the piercing mill. Such manual replacement requires a large number of man-hours, which causes a reduction in the operation rate of the piercing mill. In particular, as in recent years, when the production range of Mannesmann pipe-making equipment has been expanded for the purpose of high-efficiency production of seamless steel pipes, the number of pipe-making setups has also increased, and the work of replacing the U-shaped guides of the piercing mill has been increasing. It can also reduce the overall efficiency of seamless steel pipe production.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the problem of replacing a U-shaped guide serving as a stopper for pulling out a shell in a conventional piercing rolling mill, and has made it possible to automate and reduce the size of a piercing shell drawing device. Eliminates the need for adjustment or replacement of the perforated shell pulling device associated with pipe making setup changeover, and the perforation rolling mill and its perforated shell withdrawal for small-quantity, high-mix production of seamless steel pipes from small to large diameter pipes. It is intended to provide a way.

[0010]

The present invention relates to a piercing mill used for producing a seamless steel pipe as described in the following (1) and a (2) drawing out of a pierced shell which can be used in such a piercing mill. The method and the drawing device of (3) are summarized (see FIGS. 4 and 5).

(1) A pair of piercing rolls arranged facing each other around the pass line of the material to be rolled, a plug arranged along the pass line so as to be located between the piercing rolls, and supporting the plug A piercing mill comprising: a core bar; and a device for extracting the plug and the core bar from the shell after piercing the material to be rolled, and a device for transporting the shell after the plug and the core bar are pulled out. And the core metal withdrawing device is provided with means 11 and 12 for restraining the movement of the shell in the same direction as the plug and the core metal, and means 13 and 16 for adjusting the opening degree of the means for restraining the movement of the shell. A piercing and rolling mill characterized by the above.

[0012] It is preferable that the pulling device for the plug and the core of the piercing mill is provided with means 18 and 19 for mitigating an impact generated when restraining the movement of the shell in the same direction as the plug and the core. .

(2) The material to be rolled is moved along the pass line by using a pair of piercing rolls arranged opposite to each other around the pass line, and a plug supported by a metal core is inserted into the center of the material to be rolled. A method for pulling out a perforated shell used in a perforating rolling mill, wherein the opening of the shell stopper 11 is adjusted when the shell and the plug and core remaining on the inner surface thereof are retracted along the pass line after the perforated material is perforated. The present invention provides a perforated shell withdrawing method characterized in that only the movement of the shell is restrained, the plug and the core are pulled out from the inner surface of the shell, and then the shell is transported to the next step.

[0014] In drawing how described above, when drilling the shell is thin-walled, open the restraint of the shell tip before transporting the shell, it is desirable to prevent deformation of the shell end. (3) A pair of shells with cutouts at the
Stopper and these shell stoppers can slide
Shell stopper frame and shell
Shell stopper to adjust the opening of the stopper
Opening adjustment jacks provided at both ends of the frame and
A position adjustment model for positioning the opening adjustment jack
To switch the open / close state of the rotor and shell stopper.
The hydraulic cylinder for opening and closing the hopper and the shell stopper
Stopper for fixing to the well stopper frame
A hydraulic cylinder for a lamp.
It is a removal device. In the above pull-out device, it is provided below the stopper frame
The pivot, which is the swing center of the drawn
Reduces the impact force when the shell collides with the shell stopper
It is desirable to have a hydraulic cylinder for buffering.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A piercing and rolling mill according to the present invention comprises an apparatus for extracting a plug and a core from a shell after piercing a material to be rolled, and an apparatus for transporting the shell after extracting the plug and the core. Further, the plug and core metal pulling-out device includes means for restricting movement of the shell in the same direction as the plug and core metal, and means for adjusting the opening of the means for restricting movement of the shell. It is characterized by having. For example, by providing a shell stopper as a means for restraining the movement of the perforated shell and automating the adjustment of the opening degree of the shell stopper, the size of the drawing device can be made free.

The method for pulling out a perforated shell according to the present invention is a method used in a perforated rolling mill having the above-described configuration, and retreats a shell, a plug and a core remaining on its inner surface along a pass line after perforating a material to be rolled. In this method, only the movement of the shell is restricted, the plug and the core are pulled out from the inner surface of the shell, and then the shell is transported to the next step. In this method, in order to prevent deformation of the shell end, when the perforated shell is thin, it is desirable to release the restraint of the shell tip before transporting the shell.

A perforated shell conveying device employed in the present invention,
Alternatively, the transport means for the next step is not particularly limited, and any of a conventionally used conveyor transport method, a walking beam transport method, and the like can be applied.

According to the piercing mill and the method for extracting the pierced shell of the present invention, it is possible to eliminate the adjustment and replacement of the extraction stopper and the replacement work which are conventionally performed every time the pipe making is changed. It is effective for high-efficiency production of steel pipes, and can shorten setup time and save labor. Hereinafter, the effects of the present invention will be specifically described with reference to examples. However, the following disclosure is merely an example of the present invention, and does not limit the content of the present invention.

[0019]

FIG. 4 and FIG. 5 are diagrams showing a specific configuration example of the present invention, and the same reference numerals are used for members common to the drawings.

FIG. 4 is a perspective view showing an example of the overall configuration of an apparatus for extracting a plug and a core from a perforated shell used in the present invention. As shown in the figure, the drawing device 10 has a diamond-shaped or oval-shaped notch at a portion where it comes into contact with each other.
It is composed of a pair of shell stoppers 11 and a shell stopper frame 12 into which these are inserted. The extraction device 10
The center of the apparatus is arranged on the exit side of the piercing mill so that the center of the apparatus coincides with the pass line XX where the piercing shell moves. And the shell stopper 11 inserted in the shell stopper frame 12 is slidable, and according to the pipe production setup,
The degree of opening between the shell stoppers 11 is adjusted so as to be smaller than the outer diameter of the perforated shell and larger than the outer diameters of the plug and the cored bar.

The opening adjustment of the shell stopper 11 is performed by positioning the opening adjustment jacks 13 provided at both ends of the shell stopper frame 12, and the position adjustment motor 13 is used for positioning the opening adjustment jack 13. Is used. As shown in FIG. 4, one position adjusting motor 14 is provided.
Is driven, the amount of movement is transmitted to the opening adjustment jacks 13 at both ends via the speed reducers 15 provided at both ends, and the positioning of the opening adjustment jack 13 is performed around the pass line XX. Will be

When the shell stopper 11 is closed, the opening of the shell stopper 11 is ensured. Switching between the open state and the closed state of the shell stopper 11,
The opening and closing operation is performed separately for left and right by hydraulic cylinders 16 for opening and closing stoppers provided at both ends of the shell stopper frame 12. When the stopper opening / closing hydraulic cylinder 16 is actuated to close the shell stopper 11, the stopper clamping hydraulic cylinder 17 is actuated to fix the shell stopper 11 to the shell stopper frame 12.

As shown in FIG. 2, with the retraction of the thrust block 6, the perforated shell 4 also retreats and collides with the shell stopper 11 fixed to the shell stopper frame 12 described above. At this time, the perforated shell 4 collides with the shell stopper 11 at a predetermined speed,
Significant impact is applied to the entire shell stopper device. In order to avoid these impacts, it is desirable to provide means for reducing the impacts.

For example, as shown in FIG. 4, a pivot 19 serving as a swing center of the pull-out device 10 is provided below the stopper frame 12 so that a stopper frame having a built-in shell stopper can swing around the pivot. I do. In other words, the cushioning hydraulic cylinder 18 is installed behind a surface where the perforated shell collides with a fixed member separately provided, and at the time of collision, the impact force is reduced by releasing the pressure of the hydraulic cylinder. Thereafter, the hydraulic pressure in the hydraulic cylinder is restored, and the fixed position of the shell stopper is also restored to the predetermined position.

FIG. 5 is a detailed view of a main part for explaining a mechanism for adjusting the opening of the shell stopper according to the present invention. In the figure, the right side shows the case where the shell stopper 11 is in the closed state, and the left side shows the case where the shell stopper 11 is in the open state. As described above, shell stopper 11
The opening adjustment is performed by positioning the opening adjusting jack 13 which is set for each pipe making setup. Next, the opening degree of the shell stopper 11 in the closed state is determined by the operation of the stopper opening / closing hydraulic cylinder 16. Specifically, the opening / closing of the shell stopper 11 is performed by sliding the shell stopper 11 in the closing direction by the stopper opening / closing hydraulic cylinder 16 and stopping against the stop block 13 b provided at the tip of the opening adjustment jack 13. Is secured.

Thereafter, in order to fix the shell stopper 11 in the closed position, the hydraulic cylinder 17 for stopper clamp is used.
Activate By fixing the shell stopper 11 to the shell stopper frame 12 in this manner, it is possible to withstand the impact applied due to the collision of the perforated shell.

Concerning the transport of the perforated shell to the next step, the pulling device of the present invention allows the plug and the core bar to be immediately conveyed as soon as the plug and the core are pulled out from the inner surface of the perforated shell and retracted from the shell stopper position. At this time, if the perforated shell is thin, it is conveyed laterally while the shell tip is restrained by the shell stopper, so that the pipe end is deformed and sometimes the pipe end is torn off on one side. May occur. To avoid this situation, before transporting the perforated shell, a hydraulic cylinder for stopper clamp
It is desirable that the shell stopper 17 be opened and the hydraulic cylinder 16 for opening and closing the shell stopper be retracted to secure the opening of the shell stopper 11 larger than the outer diameter of the perforated shell so that the tip of the shell is not restrained.

Normally, when the perforated shell is thick or when priority is given to shortening the transport cycle, the shell is transported with the shell stopper closed. Even in this case, the contact surface of the shell stopper is a tapered surface so that a gap is formed between the perforated shell tube end and the contact surface of the shell stopper so that the pipe end of the perforated shell does not interfere. Can be.

[0029]

According to the piercing mill and the method for extracting a piercing shell of the present invention, the piercing shell extracting device can be automated and the size can be made free, and the piercing shell extracting device can be adjusted or replaced in accordance with the pipe making setup change. Can be eliminated. In addition, this makes it possible to achieve high-efficiency production in small-quantity multi-product production of seamless steel pipes from small to large diameter pipes.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a view for explaining a piercing state of a material to be rolled in a piercing mill.

FIG. 2 is a view for explaining a step of pulling out a perforated shell on the exit side of a rolling mill after piercing rolling.

FIG. 3 is a view showing the structure of a conventional stopper for pulling out a perforated shell.

FIG. 4 is a perspective view showing an overall configuration example of a device for pulling out a plug and a core from a perforated shell used in the present invention.

FIG. 5 is a detailed view of a main part for explaining a mechanism for adjusting an opening degree of a shell stopper according to the present invention.

[Description of Signs] 1: Roll for punching, 2: Plug 3: Rolled material, 4: Shell for punching 5, Metal core, 6: Thrust block 7, Stopper for pull-out, 8: U-shaped guide 9: Guide body, 10 : Pulling device 11: Shell stopper, 12: Shell stopper frame 13: Opening adjustment jack, 14: Position adjustment motor 15: Reducer, 16: Hydraulic cylinder for opening / closing stopper 17: Hydraulic cylinder for stopper clamp 18: Buffer Hydraulic cylinder, 19: pivot

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hirohiro Yamanaka 1850 Minato, Wakayama City, Wakayama Prefecture Sumitomo Metal Industries, Ltd. Wakayama Works (56) References JP-A-57-22806 (JP, A) JP-A-60 -24204 (JP, A) JP-A-10-99907 (JP, A) JP-A-60-71403 (JP, U) JP-A-60-84104 (JP, U) (58) Fields investigated (Int. . ^7, DB name) B21B 25/00 - 25/06 B21B 19/04

Claims (6)

(57) [Claims] 1. A pair of piercing rolls disposed opposite to each other around a pass line of a material to be rolled, a plug disposed along the pass line so as to be located between the piercing rolls, and a core supporting the plug. And a device for extracting the plug and the core from the shell after the perforation of the material to be rolled, and a device for transporting the shell after the plug and the core are extracted. the drawing device of the core and means for restraining the movement of the plug and the metal core in the same direction of the shell, and means for opening adjustment means for restraining the movement of the shell, this opening adjustment
Position adjustment mode for positioning the jack for opening adjustment
A piercing and rolling mill, wherein the piercing and rolling is carried out by a machine. 2. The apparatus according to claim 1, further comprising means for reducing an impact generated when restraining movement of the shell in the same direction as the plug and the core metal. The piercing mill according to claim 1. 3. A rolled material is moved along a pass line using a pair of piercing rolls disposed around the pass line, and a plug supported by a metal core is inserted into a central portion of the rolled material. A method for extracting a perforated shell used in a perforating rolling mill, comprising adjusting a degree of opening provided at both ends when a shell and a plug and a core remaining on an inner surface thereof are retracted along a pass line after perforating a material to be rolled. Jack positioning for
Shell whose opening has been adjusted by the position adjustment motor
A perforated shell withdrawing method, wherein only a movement of a shell is restricted by a stopper, a plug and a core are pulled out from an inner surface of the shell, and then the shell is transported to a next step. 4. The perforation according to claim 3, wherein when the perforated shell is thin, the restraint of the shell tip is released before the shell is transported to prevent deformation of the shell end. Shell extraction method. 5. A notch having a cut-out portion at a contacting portion with each other.
The pair of shell stoppers and these shell stoppers
Shell stopper frame inserted in a slidable state
And shells to adjust the opening of the shell stopper.
Opening adjustment jacks provided at both ends of the topper frame
Key and the position for positioning this opening adjustment jack.
Switching between the adjustment motor and the open / close state of the shell stopper
Hydraulic cylinder for opening and closing the stopper
To secure the par to the shell stopper frame.
And a hydraulic cylinder for upper clamp.
And withdrawal device. 6. A pull member provided below the stopper frame.
The pivot, which is the swing center of the extraction device, and the perforated shell
Buffer oil to reduce the impact force when colliding with the stopper
6. The method according to claim 5, further comprising a pressure cylinder.
Extraction device.