JPS60213301A - Rolling mill - Google Patents

Abstract

PURPOSE:To obtain a rolling mill, compact and excellent in production efficiency, by forming one piece and two pieces of work rolls into a triangular shape and installing respective backup rolls nearly on the extensions of two imaginary lines formed by connecting the axial center of the former to those of the latter two rolls respectively. CONSTITUTION:Backup rolls 4, 5 are arranged respectively on the extensions of the lines formed by connecting the center of a work roll 1 to the centers of the 1st and 2nd lower work rolls 2, 3 respectively. A rolling material advanced from the left side is subjected to the rolling reduction of the 1st time at a biting point A of the rolls 1, 2, and is successively subjected to the rolling reduction of the 2nd time at a biting point B of the rolls 1, 3. In this case, because the roll gaps at the points A, B can be independently adjusted in the 1st and 2nd rolling-reduction systems constituted of the rolls 1, 2, 4 and 1, 3, 5 respectively, a prescribed sheet thickness is obtained. Further, because the roll 1 is supported by two pieces of the large diameter-rolls 4, 5, the roll 1 is made small in diameter as compared with the rolls 2, 3, and moreover a different peripheral-speeds rolling can be performed by setting the speeds of respective rolls 1, 2, 3 to V3>V1>V2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Professional Application) The present invention relates to a rolling mill for finishing cold +1JI or @III metal strips to a predetermined product thickness.

(Prior Art) The rolling mill of the present invention can be applied not only as a cold rolling mill but also as a hot rolling mill.Here, a case where it is used as a cold rolling mill will be compared with the prior art.

Conventionally, in order to produce cold-rolled coils with a predetermined product thickness from a hot-rolled film with a constant thickness, around 6 rolling mills of 4 or 6 types were arranged in tandem.

A continuous rolling mill that continuously rolls the hot-rolled coil discharged from the uncoiler and winds it up using a winder at the rear of the rolling mill, or a continuous rolling mill that continuously rolls the hot-rolled coil discharged from the uncoiler, or a continuous rolling mill that rolls the hot-rolled coil uncoiled from the uncoiler, or a continuous rolling mill that continuously rolls the hot-rolled coil discharged from the uncoiler, or a continuous rolling mill that rolls the hot rolled coil uncoiled from the uncoiler. There are reverse-type rolling mills that are equipped with a winder and run in reverse many times until a predetermined thickness is achieved. The machine requires a large number of rolling mills, which requires a huge investment in equipment, and the production efficiency of reverse rolling mills is low because a single rolling coil is reversed many times to finish a product of a predetermined thickness. There was a problem.

Therefore, in order to solve the above-mentioned problems of existing mills, it is necessary to obtain a large rolling reduction with one rolling mill, and the mill that achieves this is the Tristar mill (Japanese Patent Laid-Open No. 54-134058 Gin) and the PVJJE rolling machine (Japanese Patent Publication No. 53-22059) have been devised and disclosed. Since these mills perform 3-point downstream rolling with one rolling mill, it is possible to achieve a very large rolling reduction ratio, and the DI ability as a compact mill with high production capacity despite a small number of stands is achieved. have. What these rolling mills have in common is that the material to be rolled is sandwiched at the rolling point.
This method uses so-called different circumferential speed rolling, in which the speeds of the work rolls are different. The effect of this different circumferential speed rolling makes it possible to reduce the rolling reaction force and reduce the size of the mill. Furthermore, in the case of the TriStar mill, the rolling reaction is achieved by making use of the so-called different diameter roll effect, which reduces the equivalent roll diameter by making the central work roll diameter smaller than the other three work roll diameters. Efforts are being made to reduce force.

As mentioned above, the Tristar mill and Pv rolling mill that have been devised in recent years utilize multi-point rolling, different circumferential speed rolling, and different diameter roll rolling, and are compact mills with a high 1@ ratio. It has the following drawbacks.

1) It is difficult to fix the position of the central two-roll (the central work roll in Tristar mills, the central two-work roll in PV rolling mills) as an absolute position due to its rigidity 1 mechanism, and therefore It is not possible to accurately set the thickness of the exit side plate.

2) Outer book roll (3 around for Tristar Mill)
Even if a bending function is added to a wooden work roll, it is difficult to control its shape because it is not possible to uniquely determine how the central work roll will be displaced or deformed.

3) In Tristar, around the central work roll is approximately 2
40' rolled material is rolled in a wound state.

Since the rolling material speed between the first rolling point and the second rolling point and the rolling material speed between the second rolling point and the third rolling point are always different, the roll circumferential speed and the rolling material speed are different in at least one of them. . As a result, a hertofriction phenomenon occurs, and unless the lubrication is extremely good, problems arise in roll wear and surface roughness of the rolled material. In addition, even in a P rolling mill, it is impossible to achieve completely different circumferential speeds (that is, the theoretical rolling state in which the material exit speed matches the roll on the high-speed rotation side), and there is always a difference between the rolled material and the roll. Relative slippage occurs between the rolling points, and a belt friction phenomenon occurs over 180' from one rolling point to the next rolling point.

4) A large amount of power is required because of three-point rolling, and in order to perform rolling at different circumferential speeds, most of the required power must be transmitted from the high-speed work roll at the final rolling point. Therefore, it may be necessary to increase the roll surface roughness in order to ensure the biting property, and in that case, it is necessary to apply light reduction again to improve the surface roughness.

5) In either case, it is difficult to thread the rolled material.

6) In any case (especially in the case of Tristar Mill),
The rolled material is unreasonable to deform, making it unsuitable for rolling thick materials.

(Object of the Invention) The object of the present invention is to eliminate the above-mentioned drawbacks of Tristar mills and PV rolling mills, and to achieve multi-point rolling of these.

The object of the present invention is to provide a compact rolling mill with high production efficiency, which is not found in conventional continuous rolling mills and reverse rolling mills, by retaining the advantages of different circumferential speed rolling and rolling with different diameter rolls.

In the present invention, two lower (or upper) work rolls are arranged for one upper (or lower) work roll, and the upper (or upper) work rolls are arranged approximately on the extension of the two center lines connecting the axes of the upper and lower work rolls. By providing a backup roll for the lower (or lower) work roll, two rolling systems are constructed around the axis of the upper (or lower) work roll.

(Structure of the Invention) An embodiment of the present invention will be described below with reference to FIGS. 4 to 7. Figure 4 is a front view of the rolled material in the example, Figure 5 is a front view of the rolled material in the example;
The figure shows a side view as seen from the exit side, and FIG. 6 shows a plan view. Further, FIG. 1757 shows the cross section CC in FIG. 4.

In FIGS. 4 to 7, 1 is an upper work roll, 2 is a first lower work roll, and 3 is a second lower work roll. In FIG. 7, the upper work roll 1 is supported at both ends by bearing boxes 8.8' through bearings 7, 7'. The first lower work roll 2 is connected to the bearing box 10 via bearings 9 and 9'.
, 10', and the second lower work roll 3 is also supported by a bearing box 11. Furthermore, upper work roll 1 is! 81 top backup roll 4
and a second upper backup roll 5, and a bearing box 12 for the first upper backup roll. 2nd-L
The backup roll bearing box 13 is movably housed in the housing 14.

The 1gl upper back up roll 4 and the second upper eight up roll 5 are operated by a worm reduction gear 111Jl&' and a lowering screw 1 by a lowering amount motor 17 shown in FIG.
5.15', it can be adjusted to any depressed position within the housing 14. Synchronization of the lowered positions of the work side and the drive side is ensured by the connection of the intermediate shaft 18. Also, between the IT lower work roll bearing box IO and the housing 14 and between the second lower work roll bearing box 11 and the housing 14, there is a liner + for pass line adjustment.
9 and 19' are provided, respectively. With these arrangements, the upper work roll 1. 1st upper backup roll 4. A first rolling system consisting of a first lower work roll 2 and an upper work roll 1 for freely setting the rolling amount between the upper work roll 2 and the second lower work roll. A second rolling system consisting of a second upper backup roll 5 and a second lower work roll is constructed in one rolling mill.

Further, in this embodiment, a built-in cylinder 20 is provided in the first lower work roll bearing box 1O, and - the upper work roll bearing box 8 and the first lower work roll bearing box]
By causing bending in the direction of the $l reduction system between 0 and 0, the shape of the rolled material at the first reduction point A can be controlled. Similarly, bearing box 1 for the second lower work roll
A built-in cylinder 21 is also installed in the upper work roll bearing box 8 and the second lower work roll bearing box 11 by generating a pending force in the direction of the second rolling system. The shape of the rolled material in B can also be freely controlled.

Next, in FIGS. 5 and 6, the main drive motor 22 is
The second lower work roll 3 is driven via the spindle 24, and the auxiliary drive motor 23 drives the first work roll 2 via the spindle 25. Generally, when rolling at different circumferential speeds, a large torque is required to drive the second lower work roll, and a relatively small torque is required for the first lower work roll, or conversely, it may be necessary to generate torque in the braking direction. Although this is known to be the case, this does not particularly limit the motor furuzuke. In this embodiment, the upper work roll 1 is idle, but in order to improve the control level for different circumferential speed pressures, the upper work roll l may be driven.

(Operation of the invention) The present invention will be explained in detail using FIG. In FIG. 2, 1 indicates the upper work roll, 2.3 indicates the first lower work roll, and fJ42 lower work roll, respectively. Hiba 7 Quatup roll 4, the second upper back up roll 5 is arranged on the extension connecting the center line of the second lower work roll 3 and the upper work roll l. First, the first roll is applied at the engagement point A between the roll 1 and the lower work roll 2.

Subsequently, the roll is rolled down for the second time at the meshing point B between the upper work roll 1 and the second lower work roll 2. in this case,
Upper work roll l, 1st lower work roll 2, 'MIJ
The first rolling system composed of three rolls, one backup roll 4, can independently adjust the gap at the IWA meeting point A.

In addition, the upper work roll 1, the second lower work roll 3, the second
The second roll consists of three rolls of back-up roll 5.
The reduction system can also independently adjust the gap at the engagement point B. For this reason, the i1-th rolling reduction amount and the second rolling reduction amount can be set reliably, so that a predetermined plate thickness can be obtained.

Furthermore, in the configuration of the present invention, the work roll 1 is the first
Backup roll 4. 2nd backup role 5-2
Since it is held by a large diameter roll, it can be made smaller in diameter than the lower work roll 2.3, and the rolling reaction force due to rolling with different diameter rolls can be reduced.

In the rolling mill of the present invention, it is possible to drive any roll, but in particular, the second lower roll 3 is driven, the first lower roll 1 is auxiliary drive, and rolling is performed while applying a reverse torque to the first lower roll l. In this case, ■3≧v as shown in Figure 3.
1>v2, and it is possible to perform rolling at different circumferential speeds. In that case, the rolling reaction force can be roughly reduced by the effect of rolling at different circumferential speeds.

Next, since the upper work roll has a relatively small diameter, the il
, 12 back-up rolls are used as support rolls for bending, a strong shape control ability can be obtained. Therefore, by adding the bending function, a rolled material with an extremely small plate crown can be obtained.

Furthermore, the fiiJ1 rolling point and the second rolling point are approximately 90°, and belt friction phenomena such as slip wear between the rolled material and the roll due to the wrapping of the rolled material around the roll are slight. In particular, when the upper work roll is a fiddler (this is the most common usage), there is no belt friction phenomenon between the rolled material and the roll.

In addition, since it is a two-point reduction, the total reduction rate is slightly lower than that of a three-point reduction mill, but there is no need to apply excessive torque from the high-speed roll at the final reduction point, and reduction can be achieved without increasing the roll surface roughness. Therefore, it has the practical advantage of being able to obtain extremely good rolled material.

Furthermore, it is possible to thread the tip of rolled material without difficulty.
Compared to the TriStar mill and PV pressure machine, it has the great advantage of not requiring any special equipment for threading or time-consuming presets.

Finally, in the rolling mill of the present invention, unlike the Tristar mill, the rolled material does not wrap around the small diameter roll for about 270 m, and the deformation and posture of the rolled material are not unreasonable, so it is possible to roll thick materials. It has the excellent effect of being able to respond to

(Effects of the Invention) The rolling mill of the present invention utilizes the advantages of different circumferential speed rolling and rolling with different diameter rolls to significantly reduce rolling reaction force compared to conventional mills, making it an extremely lightweight and compact rolling mill. can do. Similarly, since the rolling reaction force is small, it is possible to achieve a large rolling reduction at one rolling point, and since it is a two-point rolling mill, the total rolling reduction is 2 times lower than that of a conventional mill.
It can be made twice as strong. In addition, by configuring a two-rolling system, which is the biggest feature of this rolling mill,
It is possible to precisely set the reduction amount ° at the two reduction points, especially for conventional tristars.

The accuracy of the exit plate thickness, which was the biggest drawback of the PVV rolling mill, can be made extremely high. Further, by adding a bender or the like to the two-pressure system, the shape can be freely controlled. This shape control also has the advantage of being more effective than conventional mills because the rolling reaction force is small.

Next, unlike in the case of a three-point reduction mill, there is no need to apply excessive torque only from the outermost roll, so there is no need to increase roll roughness, and there is no belt friction effect, so quality such as surface texture can be improved. In good condition.

As mentioned above, when the rolling mill of the present invention is used, it is possible not only to significantly reduce equipment costs, but also to achieve high accuracy in shape and thickness, and to produce high-quality steel with good surface quality. It has the great effect of being able to obtain high-quality rolled material.

[Brief explanation of the drawing]

Figures 1 (a) and (b) show the Tristar mill and PVV.
FIG. 2 is an explanatory diagram of the principle of the present invention, FIG. 3 is an explanatory diagram of different circumferential speed rolling in the present invention, and FIG. 4 is an explanatory diagram showing the rolling mill.
The figure is a front view showing one embodiment of the rolling mill of the present invention, FIG. 5 is a side view seen from the exit side of FIG. 4, FIG. 6 is a plan view of FIG. 4, and FIG. Cross-sectional view. 1... Upper work roll 2... First lower work roll 3... Second lower work roll 4... EAI upper backup roll 5... Second upper backup roll 14... Housing 15. ... Reduction screw 16 ... Worm reducer 20 ... Built-in cylinder 22 ... Main drive motor 23 ... Auxiliary drive motor A ... First reduction point B ... Second reduction point Patent applicant Representative Patent Attorney Tomoyuki Yafuki (and 1 other person) 1st Btb) 21st!1!31

Claims (1)

[Claims] One work roll and two wooden work rolls are formed in a triangular shape, and the axis of each of the two work rolls and one
A rolling mill characterized in that each head pack-up roll is arranged substantially on an extension line of two imaginary lines connecting the axes of book work rolls, and two sets of rolling systems are constituted.