JP3887501B2 - Sizing stand for ERW welded pipe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the production line of an electric resistance welded pipe in which a strip is continuously roll-formed to form an element pipe and welded seams, the outer diameter of the element pipe after welding is drawn to a predetermined dimension. It relates to the sizing stand that finishes the product tube.
[0002]
[Prior art]
As a conventional sizing stand, as shown in FIGS. 15 to 17, a type in which an upper and lower roll pair 1 driven by roll drive shafts 6 and 6 and an undriven left and right roll pair 2 are alternately arranged, FIG. 18 and FIG. 19, there is a type in which the upper and lower roll pairs 3 driven by the roll driving shafts 7 and 7 and the non-driven left and right roll pairs 4 are arranged in the same phase.
[0003]
However, for either type, in response to the recent demand for higher production line speeds and the demand for higher apertures to reduce the number of stands by increasing the aperture per stage, the following problems Has occurred.
That is, in the former type, since the outer diameter of the pipe is wrapped with two rolls, the diameter ratio between the minimum diameter portion 8 and the maximum diameter portion 9 of the roll that is in contact with the pipe is large. The feeding speed of the pipe in the diameter portion 9 becomes extremely fast, the pipe slips and a slip mark is attached to the pipe surface, thereby deteriorating the appearance quality of the pipe.
In the case of the latter type, since the contact area of the drive roll that comes into contact with the pipe is small, the drive torque to send out the pipe is restricted, and in combination with the effect of the resistance torque of the non-drive roll, if the pipe roll exceeds a certain limit value, Slips between rolls and the tube cannot be fed out.
[0004]
As a technique for solving these problems, a drive-type three-roll sizing stand (Japanese Patent Application No. 2-95444), a drive-type four-roll sizing stand (Japanese Patent Application No. 5-262893), and the like have been proposed.
In either case, the number of rolls wrapping the pipe cross section is increased to 3 to 4, and all the rolls in contact with the pipe are driven, and the configuration is capable of high speed and high drawing.
[0005]
[Problems to be solved by the invention]
However, in both of the drive type 3 roll sizing stand and the drive type 4 roll sizing stand, if the aperture amount per one stage stand is large, for example, when trying to reduce the outside diameter by 5% or more, adjacent drives There has been a problem that a phenomenon in which the pipe material rises and protrudes from the gap between the rolls (hereinafter referred to as “biting phenomenon”) occurs.
The present invention has been made in view of the above points, and an object of the present invention is to provide a sizing stand capable of further increasing the speed and drawing without degrading various characteristics such as processing accuracy and appearance quality.
[0006]
[Means for Solving the Problems]
The present invention uses the following means in order to solve the above problems.
That is, according to the first aspect of the present invention, the outer diameter of the welded pipe is drawn in the production line of an electric resistance welded pipe in which a strip is continuously roll-formed to form a bare pipe, and the butted seam is welded. In a 4-roll sizing stand that finishes a product pipe of a predetermined size, a diameter difference is provided between the upper and lower roll pairs and the left and right roll pairs, and the smaller diameter roll pair is disposed upstream in the pipe traveling direction. An overlapping portion is provided in the portion of the roll pair in contact with the element tube and the portion of the large diameter roll pair in contact with the element tube in the direction of tube travel.
[0007]
According to a second aspect of the present invention, a drive torque from a drive source such as an electric motor is transmitted to both the upper and lower roll pairs and the left and right roll pairs, and this transmission is performed by transmission of gears, universal joints, etc. to one end of each roll shaft. This is done through the mechanism.
[0008]
According to a third aspect of the present invention, a small-diameter roll is disposed on the left and right roll pair, a large-diameter roll is disposed on the upper and lower roll pair, and a roll shaft of the left and right roll pair extends upward via a universal joint, The left and right roll drive shafts and the upper and lower roll pairs of the upper and lower roll pairs are connected to the left and right roll drive shafts parallel to the roll shaft of the upper and lower roll pairs via a gear mechanism such as a worm reduction mechanism or a bevel gear mechanism. The roll shaft is linked and linked to a drive source such as an electric motor through a single distribution gear mechanism.
[0009]
According to a fourth aspect of the present invention, a push-pull mechanism using a hydraulic cylinder is provided at a position where the sizing stand is placed on a gantry, a distribution gear mechanism and a drive source are fixed on the gantry, and the distribution gear mechanism is further provided. A detachable joint device such as a gear coupling is disposed between the sizing stand and the sizing stand so that only the sizing stand can be replaced at once.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a plan view of a sizing line comprising a plurality of sizing stands of the present invention, FIG. 2 is a side view of the same, FIG. 3 is an explanatory view of a manufacturing process of an electric resistance welded pipe, FIG. 4 is a front view of roll assembly, and FIG. FIG. 6 is a side view of the roll assembly, FIG. 7 is an explanatory view of the roll arrangement, FIG. 8 is a side view of the sizing stand and peripheral devices, FIG. 9 is an overall front view of the sizing stand, and FIG. FIG. 11 is an enlarged front view of the periphery of the throttle portion, FIG. 12 is a side view of the same, FIG. 13 is a side sectional view showing the lifting mechanism of the lower roll pair, and FIG. 14 is an explanatory view showing the procedure for replacing the sizing stand. 15 is a side view of an arrangement of a conventional sizing stand, FIG. 16 is a front view of the pair of upper and lower rolls, FIG. 17 is a front view of the pair of left and right rolls, and FIG. FIG. 19 is a same front view.
[0011]
First, an outline of a sizing line including the sizing stand of the present invention and an electric resistance welded pipe manufacturing process having the sizing line in the manufacturing line will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the sizing line 10 is composed of a gantry 16 and a plurality of sizing units 15, 15... Mounted and fixed on the gantry 16. A sizing stand 11 for drawing, a distribution gear mechanism 12 that transmits a driving force to each roll of the sizing stand 11, and a roll drive motor 13 that drives the distribution gear mechanism 12.
[0012]
The sizing line 10 having such a configuration corresponds to the final forming step in the production line of the ERW weld pipe. That is, as shown in FIG. 3, the flat band plate is formed into a cylindrical shape sequentially in a raw tube forming line 32 including an edge bend roll stand 17, a breakdown roll stand 18, a side roll stand 19, and a fin pass roll stand 20. The raw pipe is further welded to a seam that is abutted by a welding line including a squeeze roll stand 21 and a welder 22, and then the raw pipe is a product pipe in the sizing line 10 of the present invention. It is drawn to size.
[0013]
Next, the arrangement of the rolls in the sizing stand 11 will be described with reference to FIGS.
As shown in FIGS. 4 to 6, the upper roll 23 and the lower roll 24, which are large diameter rolls, are arranged vertically with the tube 5 interposed therebetween, and the axes of the upper roll 23 and the lower roll 24 are parallel to each other, Each of the axial centers is arranged perpendicular to the tube traveling direction indicated by the arrow in the drawing.
A left roll 25 and a right roll 26, which are small-diameter rolls, are arranged upstream of the upper and lower rolls 23 and 24 in the pipe traveling direction, and the left and right rolls 25 and 26 are also the same as the upper and lower rolls 23 and 24. The shaft centers are parallel to each other at the left and right positions with the tube 5 in between, and both shaft centers are disposed perpendicular to the tube traveling direction. Moreover, overlapping portions 27, 27,... Are provided in adjacent portions between the left and right roll pairs 25, 26 and the upper and lower roll pairs 23, 24 so that there is no gap when viewed from the tube traveling direction.
[0014]
That is, by securing the overlapping portions 27, 27,... In this way, the material outflow from the gaps described above can be eliminated, and the occurrence of the “biting phenomenon” at the time of high drawing can be prevented.
However, in order to fully demonstrate this biting prevention effect, the upper and lower roll pairs 23 and 24 and the left and right roll pairs 25 and 26 are brought as close as possible, and the material to be squeezed out by the left and right roll pairs 25 and 26 is used. It is necessary to prevent the material from flowing out in a state where it can be continuously squeezed by the pair of upper and lower rolls 23 and 24.
[0015]
For this purpose, as shown in FIG. 7, it is extremely effective to provide a difference in diameter between the pair of rolls and to arrange the small-diameter roll on the upstream side in the tube traveling direction from the large-diameter roll pair.
This is because when a difference in diameter is provided between the upper and lower roll pairs 23 and 24 and the left and right roll pairs 25 and 26, the roll pairs are not interfered with each other and can be brought close to each other.
Further, when the centers of the left and right roll pairs 25 and 26 of the small-diameter roll are shifted by the advancing direction offset amount 28 and arranged on the upstream side of the centers of the upper and lower roll pairs 23 and 24, the pipe 5 and the upper and lower roll pairs 23. Since the contact start point 24 of 24 and the contact start point 35 of the pair of left and right rolls 25 and 26 are substantially the same position, the offset amount of the contact start point is extremely small as 29, and the upper, lower, left and right apertures are started almost simultaneously. As a result, the tube 5 is uniformly squeezed from the entire circumference by each roll, and the entire tube starts to be deformed uniformly, so that the “extruding phenomenon”, which is a local tube material protrusion phenomenon, is suppressed. is there. If a roll pair having the same diameter as the upper and lower roll pairs 23 and 24 is arranged as the left and right roll pairs 25 and 26, the contact start point becomes 36, and the offset amount of the contact start point increases from 29 to 30. It can be seen that a large deviation occurs in the aperture start time.
FIG. 7 is a diagram in which the pair of left and right rolls 25 and 26 of the small-diameter roll is rotated 90 degrees downward with the tube traveling direction as an axis to expand the contact start point in an easy-to-understand manner.
[0016]
Therefore, the diameter difference between the upper and lower roll pairs 23, 24 and the left and right roll pairs 25, 26 is made as large as possible, and the small diameter roll pair is arranged upstream of the large diameter roll pair. The pair of rolls and the pair of small diameter rolls can be arranged close to each other, and the “biting phenomenon” can be effectively suppressed by the overlapping portions 27, 27,.
[0017]
Next, the drive mechanism of each roll will be described with reference to FIGS.
As shown in FIG. 8, power is transmitted from the roll drive motor 13 fixed on the gantry 16 to the adjacent distribution gear mechanism 12, and from the distribution gear mechanism 12, a left and right roll drive universal joint 37, an upper roll Power is transmitted to the drive shaft of each roll in the sizing stand 11 via the drive universal joint 38 and the lower roll drive universal joint 39.
Accordingly, all the upper, lower, left and right rolls are driven by the power of an electric motor or the like, and the high drawing condition necessary for the present invention can be ensured.
[0018]
First, driving of the left and right rolls 25 and 26 will be described.
A left and right roll drive shaft 48 is connected to the left and right roll drive universal joint 37, and a worm 49a fixed to the left on the left and right roll drive shaft 48 meshes with a worm wheel 49b pivotally supported in front thereof. The worm wheel 49b is connected to a left roll drive pinion 69 supported by the left roll bearing 51 through a universal joint 67, a drive extension shaft 46, and a universal joint 44. A left roll drive gear 70 meshes with the left roll drive pinion 69, and the left roll drive gear 70 is fixed to one end of a left roll shaft 72 supported by the left roll bearing 51. The left roll 25 fixed to the left roll shaft 72 is driven by the driving force transmitted from the drive roll universal joint 37.
[0019]
Similarly, a worm 50a is fixed to the right on the left and right roll drive shaft 48, and the worm 50a is connected to the right roll via the worm wheel 50b, the universal joint 68, the drive extension shaft 47, and the universal joint 45. It is connected to a pinion 78 for driving the right roll that is supported by the bearing 52. The right roll driving gear 79 meshes with the right roll driving pinion 78, and the right roll driving gear 79 is fixed to one end of the right roll shaft 73 supported by the right roll bearing 52. The right roll 26 can be driven by the driving force transmitted from the driving roll universal joint 37.
[0020]
As described above, since the gear mechanisms 49 and 50 including the worms 49a and 50a and the worm wheels 49b and 50b are interposed in the middle of the transmission mechanism to the left and right rolls 25 and 26, the driving elements of the respective rolls are freely arranged. Even when the rolls are brought close to each other as in the present invention, positional interference between the drive mechanism of the left and right rolls 25 and 26 and the drive mechanism of the upper and lower rolls 23 and 24 can be avoided.
In addition, since a plurality of universal joints 44, 45, 67, and 68 are interposed between the left and right roll drive shaft 48 and the left and right rolls 25 and 26, the change in the interval between the left roll 25 and the right roll 26, which will be described later, is hindered. Accordingly, it is possible to quickly respond to changes in the drawing amount for processing into the raw pipes and product pipes of various diameters.
The gear mechanisms 49 and 50 including the worms 49a and 50a and the worm wheels 49b and 50b may be a combination of bevel gears and are not particularly limited.
[0021]
Here, the adjustment of the roll interval between the left and right rolls 25 and 26 will be described.
The left stand 74 is fixedly provided with an opening / closing fixing nut holder 55, and the opening / closing fixing nut holder 55 is provided with a screw hole so that an outer shaft portion of the left roll opening / closing manual screw shaft 53 can be screwed. An inner shaft end of the left roll opening / closing manual screw shaft 53 is rotatably fitted to a left roll shaft holding holder block 57 for fixing and holding the left roll bearing 51. Therefore, when the left roll opening / closing manual screw shaft 53 is rotated at the outer shaft end, the left roll opening / closing manual screw shaft 53 slides in the rotation shaft direction, and the left roll provided at the inner shaft end. The shaft holding holder block 57 can be moved.
The same applies to the right stand 75. That is, an opening / closing fixing nut holder 56 is fixed to the right stand 75, and a screw hole is provided in the opening / closing fixing nut holder 56 so that an outer shaft portion of a right roll opening / closing manual screw shaft 54 can be screwed. The right roll opening / closing manual screw shaft 54 has an inner shaft end rotatably inserted into a right roll shaft holding holder block 58 for fixing and holding the right roll bearing 52. When the screw shaft 54 is rotated at the outer shaft end, the right roll opening / closing manual screw shaft 54 slides in the rotation shaft direction and moves the right roll shaft holding holder block 58 provided at the inner shaft end. be able to.
Therefore, as described above, the distance between the left and right rolls 25 and 26 supported by the plurality of universal joints 44, 45, 67 and 68 is determined by rotating the left and right roll opening / closing manual screw shafts 53 and 54. The holding holder blocks 57 and 58 are slid to change their positions so that they can be freely adjusted.
[0022]
Next, driving of the upper and lower rolls 23 and 24 will be described.
One end of the upper roll shaft 42 is connected to the upper roll driving universal joint 38, and both ends of the upper roll shaft 42 are pivotally supported by the left and right upper roll bearing boxes 61 and 61, and The roll bearing boxes 61 and 61 are slidably incorporated in the upper portions of the side frames 82 and 82 of the stands 74 and 75, respectively. The upper roll 23 is fixed at a substantially central portion of the upper roll shaft 42, and the upper roll 23 can be driven via the upper roll driving universal joint 38.
Similarly, for the lower roll 24, one end of the lower roll shaft 43 is connected to the universal joint 39 for driving the lower roll, and both ends of the lower roll shaft 43 are rotatable to the left and right lower roll bearing boxes 62 and 62. The left and right lower roll bearing boxes 62, 62 are pivotally supported and are slidably incorporated in the lower portions of the side frames 82, 82,. The lower roll 24 is fixed at a substantially central portion of the lower roll shaft 43, and the lower roll 22 can be driven via a lower roll driving universal joint 39.
In both the upper and lower rolls 23 and 24, since the driving force is transmitted from the distribution gear mechanism 12 through the universal joints 38 and 39, the interval between the upper roll 23 and the lower roll 24 described later can be easily changed. be able to.
[0023]
Here, the adjustment of the roll interval between the upper and lower rolls 23 and 24 will be described.
An upper roll positioning motor 40 is disposed above the sizing stand 11, and an upper roll positioning horizontal shaft 60 extends from the upper roll positioning motor 40 and is horizontally provided between the left and right stands 74 and 75. As shown in FIG. 13, worm wheels 77 and 77 mesh with the left and right worms 76 and 76 fixed to both ends of the upper roll positioning horizontal shaft 60, and the left and right upper rolls are engaged with the worm wheels 77 and 77, respectively. Screw shafts 65 and 65 are screwed.
In such a configuration, when the upper roll positioning motor 40 is driven, the worms 76 and 76 rotate the worm wheels 77 and 77 and are screwed into screw holes formed in the worm wheels 77 and 77. The left and right upper roll screw shafts 65 and 65 are configured to slide simultaneously in the vertical direction.
The left and right upper roll screw shafts 65 and 65 are fixed to upper roll bearing boxes 61 and 61 that pivotally support the upper roll shaft 42, and the upper roll shaft 42 is moved along with the sliding of the upper roll screw shaft 65. Slid according to the side frames 82. For this reason, the height of the upper roll 23 can be adjusted by driving the upper roll positioning motor 40.
[0024]
The same applies to the height adjustment of the lower roll 24. That is, a lower roll positioning motor 41 is disposed below the sizing stand 11, and a lower roll positioning horizontal shaft 63 extends from the lower roll positioning motor 41 and is horizontally provided between the left and right stands 74 and 75. Yes. The left and right worms 76 and 76 fixed to both ends of the lower roll positioning horizontal shaft 63 are engaged with worm wheels 77 and 77, and the left and right lower roll screw shafts 66 and 66 are screwed into the worm wheels 77 and 77. It is disguised.
Therefore, by driving the lower roll positioning motor 41, the worms 76 and 76 rotate the worm wheels 77 and 77, and the left and right lower roll screw shafts 66 and 66 slide simultaneously in the vertical direction. The height of the lower roll 24 can be adjusted via lower roll bearing boxes 62 and 62 fixed to the screw shafts 66 and 66.
[0025]
Accordingly, as described above, the distance between the upper and lower rolls 23 and 24 supported at one end by the universal joints 38 and 39 is such that the roll screw shafts 65 and 66 are moved in the vertical direction by driving the upper and lower roll positioning motors 40 and 41. It can be freely adjusted by sliding and changing the interval between the roll bearing boxes 61 and 62 fixed thereto.
In this embodiment, a mechanism comprising a worm and a worm wheel is used as the upper and lower roll positioning deceleration mechanisms 59 and 64, but is not particularly limited.
[0026]
With the configuration as described above, the driving of each roll can be mechanically controlled by a single roll drive motor, and the upper and lower roll pairs 23 and 24 and the left and right roll pairs 25 and 26 can be controlled as in the present invention. Even when there is a difference in roll diameter, it is possible to always keep the rotation period of the roll as set.
In other words, as in the conventional control in which the rotational peripheral speed is electrically adjusted with separate roll drive motors, the roll inertia difference and load resistance difference during the transition period such as line speed increase and acceleration during operation. For example, there is a risk that the control will not follow and slips due to the difference in rotational peripheral speed between the upper and lower roll pairs 23 and 24 and the left and right roll pairs 25 and 26, and a surface quality defect called slip mark may occur on the pipe surface. However, it is possible to completely control and suppress the difference and fluctuation of the rotational peripheral speed by mechanically controlling the driving of each roll with a single roll driving motor.
In the present invention, since the drive mechanism including the roll drive motor 13 and the distribution gear mechanism 12 are all mounted on the gantry 16 adjacent to the sizing stand 11, the drive mechanism is provided above the sizing stand 11 as in the prior art. Compared to the case where it is disposed, the structure is simple and stable.
[0027]
The replacement mechanism of the sizing stand 11 will be described with reference to FIGS.
As shown in FIG. 8, a push-pull mechanism 14 is disposed on the left gantry 16 of the sizing stand 11, and the push-pull mechanism 14 includes a cylinder 14a and a rod 14b protruding from the cylinder 14a so as to extend and contract. And a push-pull bar 14c fixed to the tip of the rod 14b.
When the sizing stand 11 is attached, the rod 14b is extended, the push hook 14d of the push-pull bar 14c is locked to the protrusion 85 at the bottom of the sizing stand 11, and then the rod 14b is further extended to It can be pushed and moved to the distribution gear mechanism 12 side. Further, when the sizing stand 11 is removed, the rod 14b is contracted and the pulling hook 14e of the push-pull bar 14c is brought into contact with the protrusion 86 of the sizing stand 11, and the sizing stand 11 can be pulled out to the cylinder 14a side as it is.
[0028]
An example of the replacement procedure of the sizing stand having this configuration is shown in FIG.
In the mounting operation, first, the spare sizing stand 11 suspended by the wire 87 is transported by the crane onto the gantry 16, and is closer to the cylinder 14 a than the fixed hook 84 provided on the gantry 16. It is placed between the push-in hook 14d of 14c and the drawer hook 14e (a).
Next, as described above, the rod 14b is extended so that the push-in hook 14d of the push-pull bar 14c is locked to the protrusion 85 of the sizing stand 11, and the sizing stand 11 is pushed out to the position of the fixed hook 84 as it is. The protrusion 86 is locked to the fixing hook 84 (b). Then, the left and right roll drive universal joint 37, the upper roll drive universal joint 38, and the lower roll drive universal joint 39 are all connected to the distribution gear mechanism 12, and power can be transmitted.
The removal work is basically performed in the reverse order of the attachment work. That is, the rod 14b is first pulled back, the push-in hook 14d is removed from the projection 85, the rod 14b is further contracted, the drawer hook 14e is brought into contact with the projection 86, and the sizing stand 11 is pulled out to the cylinder 14a side as it is (c). At the same time, the linkage with the distribution gear mechanism 12 by the left and right roll driving universal joint 37, the upper roll driving universal joint 38, and the lower roll driving universal joint 39 is also released. After this, the sizing stand 11 is pulled up from the gantry 16 by the wire 87, and is transported to the spare stand storage and stored.
[0029]
In this way, it is possible to replace only the sizing stand 11 with all the drive mechanisms including the roll drive motor 13 and the distribution gear mechanism 12 fixed on the gantry 16 adjacent to the sizing stand 11. Exchange can be done quickly.
That is, in the sizing line 10, roll replacement for changing the pipe size is frequently performed, so there is a strong demand for shortening the line stop time required as much as possible. However, as in the present invention, only the sizing stand 11 is replaced. If possible, prepare the same number of spare sizing stands as there are in-line stands in advance and change them to the type and position of the roll suitable for the pipe to be produced next offline. Thus, the sizing stand 11 can be replaced, and as a result, the line stop time can be minimized and a significant improvement in productivity can be achieved.
In this case, the detachable joint device between the sizing stand 11 and the distribution gear mechanism 12 has three left and right roll drive shafts 48, an upper roll upper roll shaft 42, and a lower roll lower roll shaft 43. Since the drive shafts are arranged in parallel and horizontally with each other, the configuration can be made simpler than in the prior art.
[0030]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
That is, as in claim 1, the outer diameter of the welded pipe is reduced in the production line of an electro-welded welded pipe in which a strip is continuously roll-formed to form a blank, and the butted seam is welded. In a 4-roll sizing stand that is molded and finished to a product pipe of a predetermined size, a diameter difference is provided between the upper and lower roll pairs and the left and right roll pairs, and the smaller diameter roll pair is arranged upstream in the pipe traveling direction. Since the overlapping part was provided in the direction of tube travel, the contact part of the roll pair of the roll pair and the contact part of the large-diameter roll pair was prevented, so that the biting phenomenon was reliably prevented and high drawing was achieved. As a result, it is possible to secure a good surface quality even in the case of high speed, and it is possible to increase the speed of the line by preventing slipping and to reduce the number of stand stages by increasing the amount of drawing per stage, thereby greatly improving productivity. it can.
[0031]
According to a second aspect of the present invention, a drive torque from a drive source such as an electric motor is transmitted to both the upper and lower roll pairs and the left and right roll pairs, and this transmission is performed by transmission of gears, universal joints, etc. to one end of each roll shaft. Since it was performed via the mechanism, all the upper, lower, left and right rolls are driven by power, and a high aperture can be achieved.
[0032]
According to a third aspect of the present invention, a small-diameter roll is disposed on the left and right roll pair, a large-diameter roll is disposed on the upper and lower roll pair, and a roll shaft of the left and right roll pair extends upward via a universal joint, The left and right roll drive shafts and the upper and lower roll pairs of the upper and lower roll pairs are connected to the left and right roll drive shafts parallel to the roll shaft of the upper and lower roll pairs via a gear mechanism such as a worm reduction mechanism or a bevel gear mechanism. Since the roll shaft is connected and interlocked to a drive source such as an electric motor through a single distribution gear mechanism, the position of the drive mechanism can be achieved even when the upper and lower roll pairs and the left and right roll pairs are brought close to each other as in the present invention. Interference can be prevented, and the roll rotation cycle can be kept at a set level because the roll shaft is mechanically controlled by a single roll drive motor. High quality pipes with no surface quality defects can be manufactured. Furthermore, the structure is simple and stable compared to the conventional case where a drive mechanism is installed on top of the sizing stand. Can be provided.
[0033]
According to a fourth aspect of the present invention, a push-pull mechanism using a hydraulic cylinder is provided at a position where the sizing stand is placed on a gantry, a distribution gear mechanism and a drive source are fixed on the gantry, and the distribution gear mechanism is further provided. By installing a detachable joint device such as a gear coupling between the sizing stand and the sizing stand so that only the sizing stand can be replaced at once, the line stop time required for roll replacement can be shortened and productivity can be reduced. Can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a plan view of a sizing line comprising a plurality of sizing stands of the present invention.
FIG. 2 is a side view of the same.
FIG. 3 is an explanatory diagram of a manufacturing process of an electric resistance welded pipe.
FIG. 4 is a front view of roll assembly.
FIG. 5 is an enlarged front view of a roll wrap portion.
FIG. 6 is a side view of roll assembly.
FIG. 7 is an explanatory diagram of roll arrangement.
FIG. 8 is a side view of a sizing stand and peripheral devices.
FIG. 9 is an overall front view of a sizing stand.
FIG. 10 is a side view of the same.
FIG. 11 is an enlarged front view of the periphery of the aperture portion.
FIG. 12 is a side view of the same.
FIG. 13 is a side sectional view showing an elevating mechanism for a lower roll pair.
FIG. 14 is an explanatory diagram showing a procedure for replacing a sizing stand.
FIG. 15 is an arrangement side view of a conventional sizing stand.
FIG. 16 is a front view of a pair of upper and lower rolls.
FIG. 17 is a front view of a pair of left and right rolls.
FIG. 18 is an arrangement side view of another conventional sizing stand.
FIG. 19 is a front view of the same.
[Explanation of symbols]
5 Elementary tube
11 Sizing stand
12 Distributing gear mechanism
13 Drive source
14 Push-pull mechanism
14a Hydraulic cylinder
16 frame
23 Upper roll
24 Lower roll
25 Left roll
26 Right roll
27 Overlap
37, 38, 39 Removable joint device
42 Upper roll shaft
43 Lower roll axis
44, 45 Universal joint
48 Left and right roll drive shaft
49 Gear mechanism
72, 73 Roll shaft

Claims (4)

In the production line for ERW welded pipes, in which strips are continuously roll-formed to form raw pipes and welded joints are welded, the outer diameter of the welded raw pipes is drawn into a product pipe of a predetermined size. In the 4-roll sizing stand to be finished, a difference in diameter is provided between the upper and lower roll pairs and the left and right roll pairs, the roll pair on the small diameter side is arranged upstream in the tube traveling direction, and the small diameter roll pair contacts the raw pipe A sizing stand for an electric-welded welded pipe, wherein an overlapping part is provided in a portion in contact with an elemental pipe of a roll pair on the large diameter side in a tube traveling direction. Driving torque from a driving source such as an electric motor is transmitted to both the upper and lower roll pairs and the left and right roll pairs, and this transmission is performed via a transmission mechanism such as a gear and a universal joint to one end of each roll shaft. The sizing stand for an electric resistance welded pipe according to claim 1. A small-diameter roll is provided for the left and right roll pairs, and a large-diameter roll is provided for the upper and lower roll pairs. The roll shafts of the left and right roll pairs are extended upward via a universal joint. It is connected to a left and right roll drive shaft parallel to the roll axis of the upper and lower roll pair via a gear mechanism such as a bevel gear mechanism, and the left and right roll drive shaft and the upper and lower roll shafts of the upper and lower roll pair are connected together. 3. A sizing stand for an electric resistance welded pipe according to claim 2, wherein the sizing stand is connected to and linked to a drive source via a distribution gear mechanism of the base. A push / pull mechanism using a hydraulic cylinder is provided at the mounting position of the sizing stand on the gantry, a distribution gear mechanism and a drive source are fixed on the gantry, and further, between the distribution gear mechanism and the sizing stand. 4. The sizing stand for an electric resistance welded pipe according to claim 3, wherein only a sizing stand is replaceable by disposing a detachable joint device such as a gear coupling.

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