EP1022068A1 - Piercing mill - Google Patents
Piercing mill Download PDFInfo
- Publication number
- EP1022068A1 EP1022068A1 EP98947859A EP98947859A EP1022068A1 EP 1022068 A1 EP1022068 A1 EP 1022068A1 EP 98947859 A EP98947859 A EP 98947859A EP 98947859 A EP98947859 A EP 98947859A EP 1022068 A1 EP1022068 A1 EP 1022068A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- disk
- frame
- frames
- chock
- piercing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000004519 manufacturing process Methods 0.000 claims abstract description 13
- 229910000831 Steel Inorganic materials 0.000 claims description 9
- 230000007246 mechanism Effects 0.000 claims description 9
- 239000010959 steel Substances 0.000 claims description 9
- 238000009785 tube rolling Methods 0.000 abstract description 4
- 239000000463 material Substances 0.000 description 22
- 238000005096 rolling process Methods 0.000 description 8
- 244000208734 Pisonia aculeata Species 0.000 description 5
- 238000000034 method Methods 0.000 description 4
- 238000010276 construction Methods 0.000 description 3
- 230000036316 preload Effects 0.000 description 3
- 230000002547 anomalous effect Effects 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 230000006735 deficit Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000007730 finishing process Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B19/00—Tube-rolling by rollers arranged outside the work and having their axes not perpendicular to the axis of the work
- B21B19/02—Tube-rolling by rollers arranged outside the work and having their axes not perpendicular to the axis of the work the axes of the rollers being arranged essentially diagonally to the axis of the work, e.g. "cross" tube-rolling ; Diescher mills, Stiefel disc piercers or Stiefel rotary piercers
- B21B19/04—Rolling basic material of solid, i.e. non-hollow, structure; Piercing, e.g. rotary piercing mills
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B31/00—Rolling stand structures; Mounting, adjusting, or interchanging rolls, roll mountings, or stand frames
- B21B31/08—Interchanging rolls, roll mountings, or stand frames, e.g. using C-hooks; Replacing roll chocks on roll shafts
Definitions
- the present invention relates to a piercing mill for use with a seamless steel tube and, more particularly, to a piercing mill which enables thin-wall piercing without impairing the ease of work for adjusting position of disk rollers.
- the Mannesmann tube-making process is widely employed.
- a round billet heated to a high temperature is fed as a material to be rolled into a piercing mill (a so-called "piercer"), which pierces the axial center portion of the round billet to obtain a hollow shell.
- the thus-obtained hollow shell is fed, directly or as needed after undergoing an expansion or wall-thinning process in an elongator having the same structure as that of the piercing mill, into a subsequent elongating mill such as a plug mill, a mandrel mill, or the like so as to be elongated.
- the thus-elongated tube undergoes a finishing process provided by a stretch reducer for shape correction, a reeler for polishing, and a sizer for sizing, thereby becoming a seamless steel tube product.
- the piercing mill is comprised of a pair of piercing rollers disposed in a vertical direction with respect to a pass line of a material to be rolled, and a pair of disk rollers disposed in a direction perpendicular to the direction of layout of the piercing rollers.
- the piercing mill is arranged so as to pierce and roll the material while supporting and rotating it by use of the piercing rollers and the disk rollers.
- the piercing rollers and the disk rollers are integrally retained and fixedly positioned with respect to each other within a mill housing during at least the rolling operation.
- the piercing mill processes the material while pressing the piercing rollers down on the material remained at a high temperature, and therefore working surfaces of the piercing rollers are damaged with a lapse of roll time.
- the disk rollers are also abraded when they come into contact with the material.
- the piercing rollers and the disk rollers must be periodically exchanged.
- the disk rollers must be exchanged by lifting them one at a time by use of an overhead traveling crane while the mill housing is in an open state. Use of such an overhead traveling crane in the exchange the pair of disk rollers consumes much time, inevitably resulting in a reduction in the availability of the piercing mill.
- a bulge in the outer circumference increases as the degree of draft in the wall thickness of the hollow shell increases, in turn making the hollow shell susceptible to guide flaws.
- FIG. 1 is a schematic representation of the anomalous shape of a thin-wall hollow shell formed when the hollow shell is rolled by piercing rollers through use of disk rollers.
- material 1 to be rolled is helically traveling in a direction perpendicular to the plane of the drawing while being pierced by a plug 3 and rolled by piercing rollers 2, and disk rollers 4.
- the bulge in the circumference of the material 1 becomes large as a result of a decrease in the degree of draft, the material 1 is partially drawn into the clearance between the edge of a material-receiving side of each disk roller 4 and the outgoing side of the corresponding piercing roller 2, thereby generating guide flaws in the outer surface of the material.
- the disk rollers 4 are arranged so as to cross each other at a predetermined skew angle ⁇ (alpha) with respect to a pass line X-X along which the material travels while being rolled, such that the edges of the disk rollers 4 become parallel to outgoing sides of the piercing rollers 2 with a small clearance between them. In this case, if the support rigidity of the disk rollers 4 is insufficient, the disk rollers 4 rotate in an eccentric manner, thereby promoting generation of guide flaws.
- the conventionally-proposed piercing mill is likely to generate flaws in the surface of a material to be rolled because of low support rigidity of disk rollers. Further, in the case where the disk rollers are arranged at a skew angle ⁇ , eccentric rotations of the disk rollers cannot be prevented, thereby promoting generation of the guide flaws.
- the object of the present invention is to solve the drawbacks in the conventional piercing mill and to provide a piercing mill which enables flexible manufacture of a variety of differently-sized seamless steel tubes in small quantities by improving the ease of work such as setting of the skew angle ⁇ of the disk rollers, while ensuring sufficient support rigidity of the disk rollers and expanding the range of thin-wall tube rolling, to thereby improve the performance of the piercing mill.
- the gist of the present invention resides in a piercing mill for use in manufacturing seamless steel tubes as defined by the following (1) through (4). Part number used therein are described in FIG. 4 and 5, which will be described later.
- a piercing mill of the present invention is chiefly characterized by a pair of disk frames which are attached to the respective lateral sides of the mill housing and which can be opened sideward in a pivoting way; and a pair of sliding frames which are vertically arranged within each of the disk frames so as to be slidable and to hold the disk roller integrally formed with a shaft; wherein a skew angle of each of the disk roller is set by sliding the corresponding sliding frames in opposite directions.
- the disk rollers can be exchanged without use of an overhead traveling crane.
- the piercing mill comprises upper and lower chock frames which are provided at either end of the shaft of the disk roller and which support and incorporate chocks while permitting pivoting motion; and upper and lower opening control frames which are respectively attached to the upper and lower sliding frames and control the respective positions of the chock frames.
- the disk roller integrally formed with the shaft can be supported at both of its ends by respectively fitting the chock frames into the opening control frames.
- the clearance between the exit-side rollers and the disk rollers can be minimized, so that the range of thin-wall tube rolling can be expanded. Further, since sufficient support rigidity can be secured, it is possible to prevent the generation of surface flaws in the material which would otherwise result from eccentric rotation of the disk rollers when they come into contact with the material during piercing and rolling operation. Further, an example of the scheme for supporting the chock while permitting pivoting motion is a pin support.
- the piercing mill further comprises a screw-down mechanism provided on each of the upper and lower sliding frames and a balancing device provided on the upper sliding frame or on each of the upper sliding frame and the upper opening control frame.
- the opening of the disk roller is adjusted by the screw-down mechanism, and the height of the disk roller is adjusted by the balancing device.
- the piercing mill further comprises a rotary shaft for supporting the shaft of the disk frame, clamping means provided on the disk frame, and a clamping device disposed on the mill housing.
- the disk frame is fixedly supported in a heightwise direction thereof by means of the rotary shaft and the clamping means, as well as in the direction of pivotal movement of the disk frame by the clamping device when it is closed and fixed to the mill housing.
- the piercing mill of the present invention it become possible to secure the support rigidity of the disk rollers and enable the production of tubes having a thinner wall, to thereby improve the performance of the piercing mill, while improving the ease of work for adjusting the position of disk rollers. Further, as described above, it is possible to achieve a reduction in the time required to exchange the disk rollers, as well as to save significantly labor in the operations themselves.
- FIG. 3 through 8 An example of a specific structure of the piercing mill of the present invention is shown in FIG. 3 through 8, with reference to which the effects will be described in detail. Throughout the drawings, elements common to the drawings are assigned the same reference numerals.
- FIG. 3 is a view showing an example of the structure of a mill housing of a piercing mill according to the present invention.
- a mill housing 5 which constitutes the main body of the piercing mill, the surfaces in a direction perpendicular to a pass line X-X are opened.
- a pair of piercing rollers 2 which are disposed so as to be opposite to each other with respect to the pass line X-X, and a pair of disk rollers 4 which are disposed so as to be opposite to each other and orthogonal to the piercing rollers 2.
- a pair of disk frames 6 are supported by rotary shafts 7 on the respective lateral surfaces of the mill housing 5 and can be opened sideward in a pivoting manner.
- a disk roller 4 integrally formed with a shaft is supported on the internal surface of each disk frame 6.
- FIG. 4 is a perspective view showing the overall structure by which a disk frame is supported when the disk frame is pivoted.
- the disk frame 6 is supported by the rotary shaft 7 and is pivoted by the action of an unillustrated pivot cylinder. Exchange of the disk roller is performed in a state in which the disk frame 6 is swung.
- upper and lower sliding frames 8 and upper and lower opening control frames 10 attached thereto are provided in order to vertically support the disk roller 4.
- FIG. 5 is a perspective view illustrating a main structure of the disk frame supporting the disk roller integrally formed with the shaft.
- the sliding frame pair 8 consisting of the pair of an upper sliding frame 8a and a lower sliding frame 8b is provided within the disk frame 6.
- the upper and lower sliding frames 8a and 8b can slide in the direction indicated by arrow by the operation of a hydraulic cylinder 9 and a screw-down jack 9a (a hydraulic cylinder for use with the upper sliding frame 8a is not shown in the drawing).
- the upper opening control frame 10a is provided at the front end of the center of the upper sliding frame 8a
- the lower opening control frame 10a is provided at the front end of the center of the lower sliding frame 8b.
- the disk roller 4 is integrally formed with a shaft 4s.
- an upper chock 13 is fitted to an upper part of the shaft 4s of the disk roller 4, and this upper chock 13 is connected to a chock frame 11 via pin support. Since the chock 13 is retained by and incorporated in the upper chock frame 11 through support by a pin 13p, it can be pivoted in the direction of a skew line with skewing operations, which will be described later.
- a lower chock frame 12 which incorporates and supports the chock 13 via a pin, as is the case with the upper chock frame 11, is fitted around a lower part of the shaft 4s.
- a screw-down screw support groove 11c for receiving a screw-down screw of a balancing device, which will be described later, is formed in the upper chock frame 11, and the upper chock frame 11 is fitted into the upper opening control frame 10a provided in the upper sliding frame 8a.
- the lower chock frame 12 is fitted into the lower opening control frame 10b provided in the lower sliding frame 8b.
- the disk roller 4 are vertically supported through its the opposite ends such that the upper chock 13 and the lower chock 13 are aligned vertically.
- the chocks 13 incorporated in the respective chock frames 11 and 12 are tilted around the pin 13b as a result of sliding of the upper and lower sliding frames 8a and 8b in opposite directions, setting the skew angle ⁇ of the disk roller 4 to a predetermined angle.
- FIG. 6 is a schematic illustration of an operation required to set the skew angle ⁇ of the disk roller.
- the upper chock frame 11 is fitted into the upper opening control frame 10a
- the lower chock frame 12 is fitted into the lower opening control frame 10b, so that the disk roller 4 is at both of its ends supported and is positioned in axis Y1-Y1 perpendicular to the pass line X-X.
- the chock frames 11 and 12 cause parallel movement.
- the chocks 13 having the pins 13p supported by the chock frames 11 and 12 are tilted about the pins 13p along Y2-Y2 axis, so that the disk rollers 4 is located on Y2-Y2 axis.
- the disk roller 4 is tilted at a predetermined skew angle ⁇ with respect to the pass line X-X.
- the position of the disk roller 4; i.e., its height and opening is adjusted by the balancing device provided on the upper sliding frame, as well as by a screw-down mechanism provided on the sliding frame pair 8.
- the relationship between the arrangement of the disk rollers and the height and opening adjustment is shown in FIG. 7, which will be described next.
- the sliding of the disk roller in the front/back direction is performed by the operation of the hydraulic cylinder and the screw-down jack provided on each of the upper and lower sliding frames.
- FIG. 7 is a vertical cross-sectional view showing an example of the structure of the pair of disk rollers disposed so as to be opposite to each other within a mill housing.
- the material 1 to be rolled is helically traveling in a direction perpendicular to the plane of the drawing, and a pair of disk rollers 4, 4' are disposed so as to support this material 1.
- a thrusting force F1 and a rolling force F2 act on the disk rollers 4, 4'.
- the pair of disk rollers 4, 4' are identical to each other regarding construction exclusive of the degree of exertion of the thrusting force F1. Therefore, an explanation will be hereinbelow given to solely the construction and operation of the disk roller 4 of the disk roller pair provided on the lift side of the drawing.
- the disk roller 4 is at both of its ends supported reliably, thereby providing sufficient support rigidity.
- the balancing device 14 for controlling the height of the disk roller 4 is comprised of a screw-down (screw-up) screw 15 and a pull-back rod 16.
- the screw-down screw 15 is disposed on the upper opening control frame 10a, and the pull-back rod 16 is disposed on the upper sliding frame 8a.
- the screw-down screw 15 is disposed on the upper opening control frame 10a in FIG. 7, it may be provided on the upper sliding frame 8a.
- the height of the disk roller 4 is set according to the amount of movement of the screw-down screw 15. That is, the screw-down screw 15 is inserted into the screw-down screw support groove 11c provided in the upper chock frame 11 and adapted to adjust the height of the disk roller 4. At this time, a pre-load is exerted on the disk roller 4. More specifically, as indicated by an arrow in the drawing, the pull-back rod 16 is inserted into the support groove 13c formed in the upper chock 13 and provides upward pressure in the direction opposite to the direction of screw-down action of the screw-down screw 15. This operation is called a "backlash elimination.” Since the height of the disk roller 4 is controlled after the backlash has been absorbed, the accuracy of adjustment of the disk roller 4 is improved.
- the disk roller 4' provided on the right side of FIG. 7 receives the thrusting force F1 from the material 1 in the opposite direction, and therefore the pre-load is exerted on the disk roller 4' in the direction opposite to the direction in which the disk roller 4 receives the pre-load.
- the disk rollers 4, 4' on both sides of mill housing 5 are identical to each other.
- Screw-down mechanisms 17 for controlling the opening of the disk roller 4 are each made up of the screw-down (screw-up) screw 15 and a pull-back rod (not shown), as is the case with the balancing device 14.
- the screw-down mechanisms 17 are provided to the respective upper and lower sliding frames 8a and 8b.
- the opening on the upper or lower side of the disk roller 4 is independently controlled according to the movement amount of the corresponding screw-down screw 15.
- the positions of the disk roller 4 are controlled while the backlash of the screw-down mechanism 17 by virtue of the pulling back action of the pull-back rod, and therefore the accuracy of adjustment of the disk roller can be considerably improved.
- the disk frames are closed and fixedly attached to the mill housing during the piercing and rolling operation.
- the disk frames 6 are each fixedly maintained in a heightwise direction thereof by a combination of the rotary shaft 7 pivotally supporting the disk frame 6 and clamping means 18 provided on the disk frame 6.
- the disk frames 6 are fixed in a pivoting direction thereof by a clamping device 19 disposed on the mill housing 5 at a disk frame closure position.
- FIG. 8 is a schematic representation showing an example of the structure of a clamping device disposed at a disk frame closure position in order to fix the disk frame to the mill housing.
- a clamping device 19 is made up of a hydraulic cylinder 19a, a clamp lever 19b, a clamp 19c, and a clamp block 19d.
- the disk frame 6 is fixed in its pivoting direction by the clamp lever 19b and the clamp 19c as a result of actuation of the hydraulic cylinder 19a via the clamp block 19d attached to the disk frames.
- the piercing mill of the present invention it become possible to improve the ease of work for positional adjustment required upon exchange of disk rollers without use of an overhead traveling crane, while enabling easy and reliable setting of a skew angle of the disk roller, whereby production of tubes having thinner wall is enabled.
- the piercing mill is arranged so as to be able to support both ends of a shaft integrally formed with the disk roller, which allows ensure of sufficient support rigidity. As a result, the disk rollers are prevented from rotating in an eccentric manner during the piercing and rolling operations, in turn preventing generation of surface flaws in the material to be rolled.
- the piercing mill of the present invention is equipped with superior position adjustment and clamping mechanisms, the ease of work for position adjustment and setting accuracy are maintained, and the ease of the work for exchanging disk rollers can be improved without impairment of its function.
- the piercing mill of the present invention can be widely utilized in the field of seamless tube production so as to improve the production efficiency.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Control Of Metal Rolling (AREA)
- Crushing And Grinding (AREA)
Abstract
A piercing mill, which can manufacture thin-wall tubes, can secure a
sufficient support rigidity of disk roller, and can improve the ease of work for
adjusting the position of the disk rollers. The piercing mill compresses a mill
housing, a pair of disk frames 6 which can be opened sideward in a pivoting
manner with reference to a pass line, and a pair of sliding frames 8 which are
vertically arranged within each of the disk frames so as to be slidable. A skew
angle of the disk roller 4 is set by sliding the sliding frames in opposite
directions. The piercing mill improve the ease of work for positional
adjustment required when the disk rollers are exchanged. In addition, since
the skew angle of the disk roller can be set easily and reliably, the range of
thin-wall tube rolling can be expanded.
Description
The present invention relates to a piercing mill for use with a seamless
steel tube and, more particularly, to a piercing mill which enables thin-wall
piercing without impairing the ease of work for adjusting position of disk
rollers.
As a method of manufacturing seamless steel tubes under hot working
conditions, the Mannesmann tube-making process is widely employed. In this
tube-making process, a round billet heated to a high temperature is fed as a
material to be rolled into a piercing mill (a so-called "piercer"), which pierces
the axial center portion of the round billet to obtain a hollow shell. The thus-obtained
hollow shell is fed, directly or as needed after undergoing an
expansion or wall-thinning process in an elongator having the same structure
as that of the piercing mill, into a subsequent elongating mill such as a plug
mill, a mandrel mill, or the like so as to be elongated. Subsequently, the thus-elongated
tube undergoes a finishing process provided by a stretch reducer for
shape correction, a reeler for polishing, and a sizer for sizing, thereby becoming
a seamless steel tube product.
The piercing mill is comprised of a pair of piercing rollers disposed in a
vertical direction with respect to a pass line of a material to be rolled, and a pair
of disk rollers disposed in a direction perpendicular to the direction of layout of
the piercing rollers. The piercing mill is arranged so as to pierce and roll the
material while supporting and rotating it by use of the piercing rollers and the
disk rollers. The piercing rollers and the disk rollers are integrally retained
and fixedly positioned with respect to each other within a mill housing during
at least the rolling operation.
As described above, the piercing mill processes the material while
pressing the piercing rollers down on the material remained at a high
temperature, and therefore working surfaces of the piercing rollers are
damaged with a lapse of roll time. The disk rollers are also abraded when they
come into contact with the material. For these reasons, the piercing rollers
and the disk rollers must be periodically exchanged. Particularly, the disk
rollers must be exchanged by lifting them one at a time by use of an overhead
traveling crane while the mill housing is in an open state. Use of such an
overhead traveling crane in the exchange the pair of disk rollers consumes
much time, inevitably resulting in a reduction in the availability of the piercing
mill.
Various measures have already been proposed to solve this problem
associated with the exchange of the disk rollers of the piercing mill. One
example is disclosed in Japanese Patent Publication (Kokoku) No. 63-64248;
namely, the structure of a piercing mill capable of exchanging disk rollers
without use of an overhead traveling crane. In this structure, the disk rollers
are supported by drive shafts in a cantilever fashion and, therefore, have
insufficient rigidity when they are positioned during operation. More
specifically, if the disk rollers possess low support rigidity, they may rotate in an
eccentric manner while in contact with the material, thereby generating
surface flaws in the material.
If a thin-wall hollow shell is manufactured by piercing and rolling, a
bulge in the outer circumference increases as the degree of draft in the wall
thickness of the hollow shell increases, in turn making the hollow shell
susceptible to guide flaws.
FIG. 1 is a schematic representation of the anomalous shape of a thin-wall
hollow shell formed when the hollow shell is rolled by piercing rollers
through use of disk rollers. In FIG. 1, material 1 to be rolled is helically
traveling in a direction perpendicular to the plane of the drawing while being
pierced by a plug 3 and rolled by piercing rollers 2, and disk rollers 4. At this
time, if the bulge in the circumference of the material 1 becomes large as a
result of a decrease in the degree of draft, the material 1 is partially drawn into
the clearance between the edge of a material-receiving side of each disk roller 4
and the outgoing side of the corresponding piercing roller 2, thereby generating
guide flaws in the outer surface of the material. If the amount of the drawn
portion of the hollow shell is considerably large, the material stops rotating,
thereby interrupting the rolling operation. As illustrated in FIG. 2, the disk
rollers 4 are arranged so as to cross each other at a predetermined skew angle
α (alpha) with respect to a pass line X-X along which the material travels while
being rolled, such that the edges of the disk rollers 4 become parallel to
outgoing sides of the piercing rollers 2 with a small clearance between them.
In this case, if the support rigidity of the disk rollers 4 is insufficient, the disk
rollers 4 rotate in an eccentric manner, thereby promoting generation of guide
flaws.
The conventionally-proposed piercing mill is likely to generate flaws in
the surface of a material to be rolled because of low support rigidity of disk
rollers. Further, in the case where the disk rollers are arranged at a skew
angle α, eccentric rotations of the disk rollers cannot be prevented, thereby
promoting generation of the guide flaws.
In contrast, if an attempt is made to ensure sufficient support rigidity of
the disk rollers, the structure of the piercing mill becomes complicated and
attended by a further reduction in the ease of work for setting the skew angle
α of the disk rollers and for adjusting the position thereof. The decrease in the
ease of exchange of the disk rollers results not only in the reduced availability
of the piercing mill but also in a reduction in the overall efficiency of
manufacture of seamless steel tubes, particularly in the case of recent
continuous Mannesmann tube manufacturing facilities aimed at highly
efficient production of seamless steel tubes.
The object of the present invention is to solve the drawbacks in the
conventional piercing mill and to provide a piercing mill which enables flexible
manufacture of a variety of differently-sized seamless steel tubes in small
quantities by improving the ease of work such as setting of the skew angle α of
the disk rollers, while ensuring sufficient support rigidity of the disk rollers
and expanding the range of thin-wall tube rolling, to thereby improve the
performance of the piercing mill.
The gist of the present invention resides in a piercing mill for use in
manufacturing seamless steel tubes as defined by the following (1) through (4).
Part number used therein are described in FIG. 4 and 5, which will be described
later.
A piercing mill of the present invention is chiefly characterized by a pair
of disk frames which are attached to the respective lateral sides of the mill
housing and which can be opened sideward in a pivoting way; and a pair of
sliding frames which are vertically arranged within each of the disk frames so
as to be slidable and to hold the disk roller integrally formed with a shaft;
wherein a skew angle of each of the disk roller is set by sliding the
corresponding sliding frames in opposite directions.
Through adoption of the above-described configuration, it become
possible to easily and reliably set the skew angle of the disk roller, while
improving the ease of work for adjusting the height and opening of the disk
rollers. More specifically, the disk rollers can be exchanged without use of an
overhead traveling crane.
Further, the piercing mill comprises upper and lower chock frames
which are provided at either end of the shaft of the disk roller and which
support and incorporate chocks while permitting pivoting motion; and upper
and lower opening control frames which are respectively attached to the upper
and lower sliding frames and control the respective positions of the chock
frames. The disk roller integrally formed with the shaft can be supported at
both of its ends by respectively fitting the chock frames into the opening control
frames.
As a result, in the piercing mill of the present invention, the clearance
between the exit-side rollers and the disk rollers can be minimized, so that the
range of thin-wall tube rolling can be expanded. Further, since sufficient
support rigidity can be secured, it is possible to prevent the generation of
surface flaws in the material which would otherwise result from eccentric
rotation of the disk rollers when they come into contact with the material
during piercing and rolling operation. Further, an example of the scheme for
supporting the chock while permitting pivoting motion is a pin support.
The piercing mill further comprises a screw-down mechanism provided
on each of the upper and lower sliding frames and a balancing device provided
on the upper sliding frame or on each of the upper sliding frame and the upper
opening control frame. The opening of the disk roller is adjusted by the
screw-down mechanism, and the height of the disk roller is adjusted by the
balancing device. As a result, it become possible to expand the range of thin-wall
tube rolling by the piercing mill, while maintaining the ease of work for
position adjustment and setting accuracy, and to facilitate the work for
exchanging the disk rollers.
To ensure better accuracy of setting of the disk rollers, the piercing mill
further comprises a rotary shaft for supporting the shaft of the disk frame,
clamping means provided on the disk frame, and a clamping device disposed on
the mill housing. The disk frame is fixedly supported in a heightwise direction
thereof by means of the rotary shaft and the clamping means, as well as in the
direction of pivotal movement of the disk frame by the clamping device when it
is closed and fixed to the mill housing.
Accordingly, in the piercing mill of the present invention, it become
possible to secure the support rigidity of the disk rollers and enable the
production of tubes having a thinner wall, to thereby improve the performance
of the piercing mill, while improving the ease of work for adjusting the position
of disk rollers. Further, as described above, it is possible to achieve a
reduction in the time required to exchange the disk rollers, as well as to save
significantly labor in the operations themselves.
An example of a specific structure of the piercing mill of the present
invention is shown in FIG. 3 through 8, with reference to which the effects will
be described in detail. Throughout the drawings, elements common to the
drawings are assigned the same reference numerals.
FIG. 3 is a view showing an example of the structure of a mill housing of
a piercing mill according to the present invention. Of the surfaces of a mill
housing 5 which constitutes the main body of the piercing mill, the surfaces in a
direction perpendicular to a pass line X-X are opened. In the mill housing 5
are housed a pair of piercing rollers 2 which are disposed so as to be opposite to
each other with respect to the pass line X-X, and a pair of disk rollers 4 which
are disposed so as to be opposite to each other and orthogonal to the piercing
rollers 2. A pair of disk frames 6 are supported by rotary shafts 7 on the
respective lateral surfaces of the mill housing 5 and can be opened sideward in
a pivoting manner. A disk roller 4 integrally formed with a shaft is supported
on the internal surface of each disk frame 6.
FIG. 4 is a perspective view showing the overall structure by which a
disk frame is supported when the disk frame is pivoted. The disk frame 6 is
supported by the rotary shaft 7 and is pivoted by the action of an unillustrated
pivot cylinder. Exchange of the disk roller is performed in a state in which the
disk frame 6 is swung. Inside the disk frame 6, upper and lower sliding
frames 8 and upper and lower opening control frames 10 attached thereto are
provided in order to vertically support the disk roller 4.
FIG. 5 is a perspective view illustrating a main structure of the disk
frame supporting the disk roller integrally formed with the shaft. As shown in
FIG. 7 in an enlarged manner, the sliding frame pair 8 consisting of the pair of
an upper sliding frame 8a and a lower sliding frame 8b is provided within the
disk frame 6. The upper and lower sliding frames 8a and 8b can slide in the
direction indicated by arrow by the operation of a hydraulic cylinder 9 and a
screw-down jack 9a (a hydraulic cylinder for use with the upper sliding frame
8a is not shown in the drawing). The upper opening control frame 10a is
provided at the front end of the center of the upper sliding frame 8a, and the
lower opening control frame 10a is provided at the front end of the center of the
lower sliding frame 8b.
In contrast, the disk roller 4 is integrally formed with a shaft 4s. In FIG.
5, an upper chock 13 is fitted to an upper part of the shaft 4s of the disk roller 4,
and this upper chock 13 is connected to a chock frame 11 via pin support.
Since the chock 13 is retained by and incorporated in the upper chock frame 11
through support by a pin 13p, it can be pivoted in the direction of a skew line
with skewing operations, which will be described later. A lower chock frame
12 which incorporates and supports the chock 13 via a pin, as is the case with
the upper chock frame 11, is fitted around a lower part of the shaft 4s.
A screw-down screw support groove 11c for receiving a screw-down screw
of a balancing device, which will be described later, is formed in the upper chock
frame 11, and the upper chock frame 11 is fitted into the upper opening control
frame 10a provided in the upper sliding frame 8a. The lower chock frame 12 is
fitted into the lower opening control frame 10b provided in the lower sliding
frame 8b.
As a result of fitting of the chock frames 11 and 12 pin-supported at the
opposite ends of shaft 4s of the disk roller 4 into the upper and lower opening
control frames 10, the disk roller 4 are vertically supported through its the
opposite ends such that the upper chock 13 and the lower chock 13 are aligned
vertically. Subsequently, the chocks 13 incorporated in the respective chock
frames 11 and 12 are tilted around the pin 13b as a result of sliding of the upper
and lower sliding frames 8a and 8b in opposite directions, setting the skew
angle α of the disk roller 4 to a predetermined angle.
FIG. 6 is a schematic illustration of an operation required to set the skew
angle α of the disk roller. In the setting operation, the upper chock frame 11 is
fitted into the upper opening control frame 10a, and the lower chock frame 12 is
fitted into the lower opening control frame 10b, so that the disk roller 4 is at
both of its ends supported and is positioned in axis Y1-Y1 perpendicular to the
pass line X-X. When the sliding frames 8a and 8b are slid in opposite
directions, the chock frames 11 and 12 cause parallel movement. With this
movement, the chocks 13 having the pins 13p supported by the chock frames 11
and 12 are tilted about the pins 13p along Y2-Y2 axis, so that the disk rollers 4
is located on Y2-Y2 axis. Through these operations, the disk roller 4 is tilted
at a predetermined skew angle α with respect to the pass line X-X.
The position of the disk roller 4; i.e., its height and opening is adjusted
by the balancing device provided on the upper sliding frame, as well as by a
screw-down mechanism provided on the sliding frame pair 8. The relationship
between the arrangement of the disk rollers and the height and opening
adjustment is shown in FIG. 7, which will be described next. As described
above, the sliding of the disk roller in the front/back direction is performed by
the operation of the hydraulic cylinder and the screw-down jack provided on
each of the upper and lower sliding frames.
FIG. 7 is a vertical cross-sectional view showing an example of the
structure of the pair of disk rollers disposed so as to be opposite to each other
within a mill housing. In FIG. 7, the material 1 to be rolled is helically
traveling in a direction perpendicular to the plane of the drawing, and a pair of
disk rollers 4, 4' are disposed so as to support this material 1. Associated with
piercing of the material 1, a thrusting force F1 and a rolling force F2 act on the
disk rollers 4, 4'. The pair of disk rollers 4, 4' are identical to each other
regarding construction exclusive of the degree of exertion of the thrusting force
F1. Therefore, an explanation will be hereinbelow given to solely the
construction and operation of the disk roller 4 of the disk roller pair provided on
the lift side of the drawing.
As previously described, the chock frames 11 and 12 fitted around the
shaft 4s of the disk roller 4 through chock 13 by means of pin 13p, are
supported by the pair of upper and lower sliding frames 8a and 8b via the
opening control frames 10a and 10b. As a result, the disk roller 4 is at both of
its ends supported reliably, thereby providing sufficient support rigidity.
The balancing device 14 for controlling the height of the disk roller 4 is
comprised of a screw-down (screw-up) screw 15 and a pull-back rod 16. The
screw-down screw 15 is disposed on the upper opening control frame 10a, and
the pull-back rod 16 is disposed on the upper sliding frame 8a. Although the
screw-down screw 15 is disposed on the upper opening control frame 10a in FIG.
7, it may be provided on the upper sliding frame 8a.
The height of the disk roller 4 is set according to the amount of
movement of the screw-down screw 15. That is, the screw-down screw 15 is
inserted into the screw-down screw support groove 11c provided in the upper
chock frame 11 and adapted to adjust the height of the disk roller 4. At this
time, a pre-load is exerted on the disk roller 4. More specifically, as indicated
by an arrow in the drawing, the pull-back rod 16 is inserted into the support
groove 13c formed in the upper chock 13 and provides upward pressure in the
direction opposite to the direction of screw-down action of the screw-down screw
15. This operation is called a "backlash elimination." Since the height of the
disk roller 4 is controlled after the backlash has been absorbed, the accuracy of
adjustment of the disk roller 4 is improved. As previously described, the disk
roller 4' provided on the right side of FIG. 7 receives the thrusting force F1 from
the material 1 in the opposite direction, and therefore the pre-load is exerted on
the disk roller 4' in the direction opposite to the direction in which the disk
roller 4 receives the pre-load. In other respects regarding construction and
operation, the disk rollers 4, 4' on both sides of mill housing 5 are identical to
each other.
Screw-down mechanisms 17 for controlling the opening of the disk roller
4 are each made up of the screw-down (screw-up) screw 15 and a pull-back rod
(not shown), as is the case with the balancing device 14. The screw-down
mechanisms 17 are provided to the respective upper and lower sliding frames
8a and 8b. As a result, the opening on the upper or lower side of the disk roller
4 is independently controlled according to the movement amount of the
corresponding screw-down screw 15. The positions of the disk roller 4 are
controlled while the backlash of the screw-down mechanism 17 by virtue of the
pulling back action of the pull-back rod, and therefore the accuracy of
adjustment of the disk roller can be considerably improved.
The disk frames are closed and fixedly attached to the mill housing
during the piercing and rolling operation. To this end, as illustrated in FIG. 4,
the disk frames 6 are each fixedly maintained in a heightwise direction thereof
by a combination of the rotary shaft 7 pivotally supporting the disk frame 6 and
clamping means 18 provided on the disk frame 6. In contrast, the disk frames
6 are fixed in a pivoting direction thereof by a clamping device 19 disposed on
the mill housing 5 at a disk frame closure position.
FIG. 8 is a schematic representation showing an example of the
structure of a clamping device disposed at a disk frame closure position in order
to fix the disk frame to the mill housing. A clamping device 19 is made up of a
hydraulic cylinder 19a, a clamp lever 19b, a clamp 19c, and a clamp block 19d.
The disk frame 6 is fixed in its pivoting direction by the clamp lever 19b and the
clamp 19c as a result of actuation of the hydraulic cylinder 19a via the clamp
block 19d attached to the disk frames. In this case, it is desirable to provide a
level liner 20 to prevent the deflection of the disk frame 6 under its own weight.
According to the piercing mill of the present invention, it become possible
to improve the ease of work for positional adjustment required upon exchange
of disk rollers without use of an overhead traveling crane, while enabling easy
and reliable setting of a skew angle of the disk roller, whereby production of
tubes having thinner wall is enabled. Further, the piercing mill is arranged so
as to be able to support both ends of a shaft integrally formed with the disk
roller, which allows ensure of sufficient support rigidity. As a result, the disk
rollers are prevented from rotating in an eccentric manner during the piercing
and rolling operations, in turn preventing generation of surface flaws in the
material to be rolled.
Moreover, since the piercing mill of the present invention is equipped
with superior position adjustment and clamping mechanisms, the ease of work
for position adjustment and setting accuracy are maintained, and the ease of
the work for exchanging disk rollers can be improved without impairment of its
function.
Therefore, the piercing mill of the present invention can be widely
utilized in the field of seamless tube production so as to improve the production
efficiency.
Claims (5)
- A piercing mill for use with a seamless steel tube manufacturing system having an integral type mill housing which houses a pair of piercing rollers disposed so as to be opposite to each other with respect to a pass line, and a pair of disk rollers disposed so as to be opposite to and to cross each other such that a clearance between the surface of a material-receiving side of each disk roller and the surface of an outgoing-side of each piercing roller becomes small, characterized by comprising: a pair of disk frames which are attached to the respective lateral sides of the mill housing and which can be opened sideward in a pivoting manner; and a pair of sliding frames which are vertically arranged within each of the disk frames so as to be slidable and to hold the disk roller integrally formed with a shaft, wherein a skew angle of each of the disk roller is set by sliding the corresponding sliding frames in opposite directions.
- The piercing mill as defined in claim 1, characterized by further comprising an upper chock frame which is fitted to an upper portion of a shaft of the disk roller and which supports and incorporates a chock while permitting pivoting motion; a lower chock frame which is fitted around a lower portion of the shaft of the disk roller and which supports and incorporates the chock while permitting pivoting motion; an upper opening control frame which is attached to the upper sliding frame of the pair of sliding frames and controls the opening of the upper chock frame; and a lower opening control frame which is attached to the lower sliding frame and controls the opening of the lower chock frame, wherein the disk roller integrally formed with the shaft is supported at both of its ends by respectively fitting the chock frames into the opening control frames.
- The piercing mill as defined in claim 2, characterized in that the chock is pivotably supported via a pin.
- The piercing mill as defined in any one of claim 1 -3, characterized in that the height of the disk roller is adjusted by a balancing device provided on the upper sliding frame; and the opening of the disk roller is adjusted by screw-down mechanisms provided on the upper and lower sliding frames.
- The piercing mill as defined in any one of claims 1 through 4, characterized by further comprising: a rotary shaft for supporting the shaft of the disk frame; clamping means provided on disk frame; and a clamping device disposed on the mill housing, whereby the disk frame is fixedly supported in a heightwise direction thereof by means of the rotary shaft and the clamping means, as well as in the direction of pivotal movement of the disk frame by the clamping means when it is closed and fixed to the mill housing.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP28002097 | 1997-10-14 | ||
JP28002097 | 1997-10-14 | ||
PCT/JP1998/004630 WO1999019093A1 (en) | 1997-10-14 | 1998-10-14 | Piercing mill |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1022068A1 true EP1022068A1 (en) | 2000-07-26 |
EP1022068A4 EP1022068A4 (en) | 2002-01-16 |
Family
ID=17619189
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP98947859A Withdrawn EP1022068A4 (en) | 1997-10-14 | 1998-10-14 | Piercing mill |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP1022068A4 (en) |
JP (1) | JP3239896B2 (en) |
WO (1) | WO1999019093A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
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CN104098257A (en) * | 2013-04-03 | 2014-10-15 | 颜良德 | Spiral transparent pipe pin-bending machine |
WO2016128923A1 (en) * | 2015-02-11 | 2016-08-18 | Danieli & C. Officine Meccaniche S.P.A. | Cross-rolling rolling stand for seamless pipes, with interchangeable lateral guide device |
CN111842742A (en) * | 2020-08-26 | 2020-10-30 | 太原科技大学 | Bevel gear driven single-ring roller rotary rolling mechanism |
CN112024607A (en) * | 2020-08-26 | 2020-12-04 | 太原科技大学 | Bevel gear driven double-ring roller rotary rolling mechanism |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
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CN100496780C (en) * | 2006-12-29 | 2009-06-10 | 太原重工股份有限公司 | Device for regulating baking angle of roll-box of large horizontal perforating machine |
CN107876566B (en) * | 2017-12-14 | 2023-07-04 | 天津腾飞钢管有限公司 | Seamless steel tube positioning and adjusting device |
CN111804855B (en) * | 2020-08-26 | 2022-08-02 | 太原科技大学 | Three-freedom-degree rotary rolling machine |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4488419A (en) * | 1981-08-19 | 1984-12-18 | Kocks Technik Gmbh & Co. | Skew rolling mill for tubes |
JPS6364248A (en) * | 1986-09-05 | 1988-03-22 | Hitachi Ltd | Color picture tube |
US5479805A (en) * | 1993-03-15 | 1996-01-02 | Mannesmann Aktiengesellschaft | Two-high cross rolling mill with guide disks |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS591008A (en) * | 1982-06-25 | 1984-01-06 | Ishikawajima Harima Heavy Ind Co Ltd | Disk guide exchanging device of piercer |
JPS6390306A (en) * | 1986-10-02 | 1988-04-21 | Kawasaki Steel Corp | Tilt type rolling method for seamless tube and its device |
JP2815749B2 (en) * | 1992-01-23 | 1998-10-27 | 住友重機械工業株式会社 | Vertical inclined drilling machine |
JP2558263Y2 (en) * | 1993-06-29 | 1997-12-24 | 住友重機械工業株式会社 | Adjustment device for disc roll for cross drilling machine |
-
1998
- 1998-10-14 EP EP98947859A patent/EP1022068A4/en not_active Withdrawn
- 1998-10-14 JP JP2000515711A patent/JP3239896B2/en not_active Expired - Fee Related
- 1998-10-14 WO PCT/JP1998/004630 patent/WO1999019093A1/en not_active Application Discontinuation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4488419A (en) * | 1981-08-19 | 1984-12-18 | Kocks Technik Gmbh & Co. | Skew rolling mill for tubes |
JPS6364248A (en) * | 1986-09-05 | 1988-03-22 | Hitachi Ltd | Color picture tube |
US5479805A (en) * | 1993-03-15 | 1996-01-02 | Mannesmann Aktiengesellschaft | Two-high cross rolling mill with guide disks |
Non-Patent Citations (2)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 012, no. 287 (E-643), 5 August 1988 (1988-08-05) & JP 63 064248 A (HITACHI LTD), 22 March 1988 (1988-03-22) * |
See also references of WO9919093A1 * |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104098257A (en) * | 2013-04-03 | 2014-10-15 | 颜良德 | Spiral transparent pipe pin-bending machine |
CN104098257B (en) * | 2013-04-03 | 2016-08-03 | 颜良德 | Spiral bright pipe bending legs machine |
WO2016128923A1 (en) * | 2015-02-11 | 2016-08-18 | Danieli & C. Officine Meccaniche S.P.A. | Cross-rolling rolling stand for seamless pipes, with interchangeable lateral guide device |
CN107206441A (en) * | 2015-02-11 | 2017-09-26 | 丹尼尔和科菲森梅克尼齐有限公司 | With the replaceable tandem rolling formula rolling machine frame for seamless pipe for being laterally guided equipment |
CN111842742A (en) * | 2020-08-26 | 2020-10-30 | 太原科技大学 | Bevel gear driven single-ring roller rotary rolling mechanism |
CN112024607A (en) * | 2020-08-26 | 2020-12-04 | 太原科技大学 | Bevel gear driven double-ring roller rotary rolling mechanism |
Also Published As
Publication number | Publication date |
---|---|
EP1022068A4 (en) | 2002-01-16 |
JP3239896B2 (en) | 2001-12-17 |
WO1999019093A1 (en) | 1999-04-22 |
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