JPS6325841B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rolling apparatus that can produce products with good shapes.

Reducing the rolling load generated during strip rolling has many advantages, such as downsizing the rolling mill, reducing operating costs due to reduced roll wear, and making it easier to roll high-strength materials. As shown in the figure, wrap strip a around rolls b and c,
A variable speed rolling mill has been developed and is already known in the art, which performs rolling so that the speeds of strip a and rolls b and c match at points d and e.

When rolling is performed using such a rolling mill, the direction of the frictional force acting on the contact arc df⌒ of roll b and the direction of the frictional force acting on the contact arc df⌒ of roll b and roll c
The direction of the frictional force acting on the contact arc eg⌒ is reversed, and the frictional force in the opposite direction acts on the upper and lower sides of the strip a, resulting in an increase in rolling force due to the effect of friction, that is, a friction hill.
is eliminated, and the rolling force is significantly reduced compared to normal rolling where the upper and lower rolls have the same circumferential speed. Furthermore, in order to stably achieve the rolling conditions as described above, it is desirable that the winding angles θ _b and θ c of the strip a around the rolls b and _c be as large as possible.

As shown in Fig. 2, the effect of the winding angles θ _{b and} θ _c is, for example, when the roll gap changes in the strip width direction due to bending deformation of rolls b and c due to rolling force, the strip The tension distribution in the width direction of the sheet changes, and within a certain range, the elongation rate remains constant regardless of the size of the roll gap, so it has the effect of giving uniform elongation in the width direction of the sheet and correcting the shape.

The value of tension that can change at this time is determined by roll b
If the side is Δt _b and the roll c side is Δt _c , then t ₀ −t ₀ e ^- 〓〓b≦Δt _b ≦t ₀ e〓〓b−t ₀ ...Equation (i) t ₁ −t ₁ e ^- 〓 〓c≦Δt _c ≦t ₁ e〓〓c−t ₁ ...Equation (ii) μ ; Friction coefficient between roll and strip θ _b ; Wrap angle of roll b θ _c ; Wrap angle of roll c t ₀ ; Inlet tension t ₁ ; expressed as outlet tension. Therefore, the larger the wrap angles θ _b and θ _c are, the larger the range in which the tensions Δt _b and Δt _c can be taken becomes, and the larger the shape modification effect becomes.

For this reason, such rolling mills require relatively narrow widths (e.g.
When rolling a strip with a width of 200 to 300 mm or less, no problem occurs, but as shown in Figure 3, when rolling a relatively wide strip a (for example, 1000 mm or more), the rolling force causes considerable deformation in roll r. Also, as shown in Fig. 4, roll r undergoes deformation due to thermal expansion and load during rolling, and the tension distribution in the width direction of the strip can no longer be corrected, resulting in a strip with good flatness and good shape. could not be rolled.

On the other hand, the entrance tension: t ₀ has the effect of reducing the entrance tension: t _b at the roll bite part by wrapping the strip around the roll b in the range of t _b = t ₀ e ^- 〓〓 < t ₀ . . This occurs when the rolling load is large relative to the elongation rate, but if a strip with a poor shape is wound around the roll on the entry side, the strip will not come into contact with the roll partially in the width direction. Local sagging occurs. This results in extreme tension nonuniformity in the width direction, which further deteriorates the shape of the strip during rolling and also causes meandering of the strip.

Furthermore, if the rolls a and b in FIG. 1 are made smaller in diameter and backing rolls are installed above and below them, the strip will be rolled between the backing rolls and, therefore, no backing rolls are generally provided. Therefore, rolls a and b need to have a large diameter to prevent bending.
This resulted in an increase in rolling force and torque.

The present invention was made with the object of making it possible to easily shape the strip by making the tension distribution uniform in the axial direction of the strip, and also to save power. a small-diameter roll supported by a backing roll; and a small-diameter roll disposed on the side opposite to the intermediate roll of the small-diameter roll and driven at a different circumferential speed from the small-diameter roll, and working together with the small-diameter roll to strip the strip. A rolling roll for rolling, an arm whose base end is pivoted downstream of the rolling roll and the small-diameter roll in the strip traveling direction and is capable of swinging in a vertical plane parallel to the strip traveling direction; The strip is pivotably supported on an arm parallel to each of the rolls and is passed between the small-diameter roll and the rolling roll, and is capable of wrapping the strip around the small-diameter roll and the backing roll at a required winding angle. A roll having a small diameter supported by the backing roll via an intermediate roll; a rolling roll disposed on the side opposite to the intermediate roll of the roll and driven at a different circumferential speed from the small-diameter roll and cooperating with the small-diameter roll to roll the strip; the rolling roll and the small-diameter roll; a rotary guide capable of rotating in a vertical plane parallel to the strip traveling direction on a line passing through the rotation center of the strip and near a position where the rolling roll and the small diameter roll face each other; The strip, which is pivoted in parallel with the roll and passed between the small diameter roll and the rolling roll, can be wound around the small diameter roll and the backing roll at a required winding angle, and also between the small diameter roll and the backing roll. The present invention is characterized by the provision of a deflector roll that can form a free span portion in which the strip does not come into contact with any of the rolls.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 shows a first embodiment of the present invention, in which 1 is a rolling mill housing, 2 is a small-diameter roll that is fitted into a housing window so as to be able to rise and fall freely, and is pivotally connected to a roll shaft box 3 so as to be freely drivable; is a similar roll axle box 5
6 is an intermediate roll pivoted to a roll shaft box 7 and located above the small diameter roll 2; 8 is pivotally mounted to a roll shaft box 9 and backs up the roll 6. A reserve roll to do, 1
2 and 12' are pivotally connected to the tips of arms 11 and 11' which can swing in a vertical plane parallel to the direction of strip movement by hydraulic cylinders 10 and 10'.
13 is a reduction cylinder, 14 is a reduction screw, 15, 16, 1
7 is a hydraulic piston device for roll balancing and roll bending, and 18 and 19 are deflector rolls arranged at the front and rear of the rolling mill main body.

When the strip S is wound around rolls and rolled, the rods of the hydraulic cylinders 10, 10' are moved back to position the rolls 12, 12' on the pass line, and the strip S is rolled at the lower part of the deflector roll 18, the upper part of the roll 12, Between rolls 2 and 4, roll 1
2' upper part and the lower part of the deflector roll 19,
By rotating the roll 12' on the downstream side of the rolling mill main body with respect to the strip traveling direction above the roll 8 by the hydraulic cylinder 10', the strip S is wound around the roll 2 and around the roll 8, and A free span part A is formed between the rolls 2 and 8 in which the strip S does not contact the rolls 2 and 8 or other rolls, and rolling is performed by driving the rolls 2 and 4 at different circumferential speeds. The strip on the entry side of the roll bit part (rolling part) is
Since it is not wrapped around roll 4, the tension applied to the strip is not reduced.
Even if the strip has a bad shape, the tension will flatten the shape of the strip. Also, the strip is not rolled between rolls 8 and 12';
The pressing force of the strip S by the roll 12' is
Assuming p', the strip tension T of the roll bit part (rolling part) is T = (μp' + T ₁ ) ^e 〓〓 T ₁ : Output side tension μ. Coefficient of friction between the roll and the strip θ : Strip The winding angle is the sum of the winding angle θ ₁ for roll 2 and the winding angle θ ₂ for roll 8 (see Figure 5). From this equation, by winding the strip S around rolls 2 and 8 and applying force p', S
It can be seen that the tension increases. Also, the roll 2 without the strip wound thereon has a smaller diameter than the roll 4 with the strip wound around it. It may be considered that the rolling load is approximately proportional to the diameter of the rolling roll. In this case, the average roll diameter: D _M is 2/D _M = 1/D ₄ + 1/D ₂ , where D ₄ : Diameter of roll 4 D ₂ : Diameter of roll 2, and D ₂ < D _M < D ₄ becomes.

Therefore, if the roll diameter of a conventional rolling mill that wraps the strip around the upper and lower rolls is the same as D ₄ , the rolling load will be lower by the amount that the average roll diameter is smaller than the rolling load, and the roll torque will also be lower. . Therefore, rolling can be performed with a small rolling force, and if the rolling force is the same as when the strip is not wound, a large rolling reduction or elongation can be obtained. Alternatively, rolls 2 and 4 that are not subjected to rolling reaction force
Either or both may be provided with a shape control device such as roll bending. Also, rolls 2 and 8
Since the free span part A is provided between the two to form a space, it is possible to install a nozzle header for roll cooling water in this space, and since the winding angle of the roll 2 is small, it is easy to cool the roll 2. Easy to roll bend.

When the strip S is rolled in a direction opposite to that shown in FIG.
is lowered, the roll 12' is rotated upward, and the strip S is wound around the rolls 2 and 8 from the direction opposite to that shown in FIG.

When changing the rolls, lower both rolls 12 and 12' to the pass line, leave the strip S extending approximately horizontally between rolls 2 and 4, and place each roll together with the axle box against the paper surface of Fig. and move it in the right angle direction and replace it. In FIG. 5, the rolls 4 and 2 are being driven. Further, the roll on the side where the roll is wound may drive any one of 2, 6, and 8 rolls, or a plurality of rolls. The rolling method includes different peripheral speed rolling in which the circumferential speed of the roll 4 is made to match the strip inlet speed and the strip exit speed is made to be the same, or different circumferential speed rolling in which the circumferential speed of the roll 4 and the strip exit speed are made to be the same and the roll 2 It is possible to perform rolling at different circumferential speeds in which the circumferential speed of the strip and the strip entry speed are matched.

6 and 7 show a second embodiment of the present invention, in which the center of rotation is located on a line passing through the centers of rotation of the rolls 2 and 4, and near the position where the rolls 2 and 4 face each other, parallel to the direction in which the strip travels. A rotary guide 20 that can be rotated in a vertical plane is supported by a support roll 21, and a gear 22 that can be rotated by a drive device (not shown) is meshed with the gear portion of the rotary guide 20. , rotatable deflector rolls 23, 23' are arranged at required positions on the rotary guide 20.

When the strip S is wound around a roll and rolled, the rotary guide 20 is rotated to position the deflector roll 23' at the solid line position in FIG. The rotary guide 20 is rotated clockwise from the state shown in FIG.
8, a free span part A is formed in which the strip S does not come into contact with the rolls 2, 8 or other rolls, and the direction of the strip S is changed by a deflector roll 23 (see FIG. 6). Rolling is then performed by driving the rolls 2 and 4 so that their circumferential speeds are different.

When replacing the rolls, the rotary guide 20 is rotated to the position shown in FIG. 7, and the rolls are replaced together with the axle box.

8 and 9 show a third embodiment of the present invention. In the previous embodiment, the roll 4 on which the strip is not wound has a large diameter, and the roll 2 on which the strip is wound has a small diameter, whereas in this embodiment In the example, the rolling roll 4' on which the strip is not wound is also made small in diameter, and receives a rolling reaction force below the rolling roll 4'.
A backing roll 24 supported by a roll shaft box 25 is provided. Therefore, it is possible to perform rolling with a lower rolling force than in the previous embodiment, and if the rolling force is the same as in the case where the strip is not wound, a large reduction ratio can be obtained. Also, each roll 2, 4', 6, 8, 2
Among the roll axle boxes 3, 5'7, 9, 25 that support the roll axle boxes 3, 5, 3, 7, 7, 9
Hydraulic pistons 15, 16, 5', 25,
These hydraulic pistons 15, 16, 17, and 26 can control roll bending, so that a strip with a better shape can be obtained.

When wrapping the strip S around a roll,
Since it is carried out in the same manner as the embodiments shown in FIGS. 6 and 7, the explanation will be omitted.

In the embodiment of the present invention, the same reference numerals are given to the same parts in FIGS. 5 to 9.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

According to the rolling apparatus of the present invention, it is possible to obtain a large elongation rate or reduction rate, and it is also possible to easily control the shape of the strip and reduce the rolling force, thereby reducing power consumption. Since the front strip is hardly wrapped around the roll, the tension on the entry side is reduced and the shape of the strip is not distorted.

Since there is a free span part of the strip between the two sets of rolls around which the strip is wound, a nozzle header for cooling the roll can be placed in the space.
Also, since the angle at which the strip is wrapped around a set of rolls is small, the rolls can be completely cooled.

Various excellent effects can be achieved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional variable speed rolling mill, Fig. 2 is a perspective view showing changes in rolling force distribution, Fig. 3 is an explanatory diagram showing bending deformation of the roll, and Fig. 4 is a diagram showing the thermal crown of the roll. FIG. 5 is an explanatory diagram of the first embodiment of the rolling apparatus of the present invention, FIG. 6 is an explanatory diagram of the second embodiment of the rolling apparatus of the present invention, and FIG. 7 is an explanatory diagram of the rolling apparatus of FIG. 6. FIG. 8 is an explanatory diagram of the third embodiment of the rolling apparatus of the present invention; FIG.
The figure is an explanatory view of the rolling apparatus shown in FIG. 8 during sheet passing and roll rearrangement. In the figure, 1 is a rolling mill housing, 2 is a small diameter roll, 4 is a large diameter roll, 6 is an intermediate roll, 8 is a backing roll, 10, 10' are fluid pressure cylinders, 11,
11' is the arm, 12, 12' are the rolls, 18, 1
9 is a deflector roll, 20 is a rotary guide, 23 and 23' are deflector rolls, and S is a strip.

Claims (1)

[Scope of Claims] 1. A small-diameter roll supported by a backing roll via an intermediate roll, and a roll disposed on the side opposite to the intermediate roll of the small-diameter roll and driven at different circumferential speeds from the small-diameter roll. a rolling roll that rolls the strip in cooperation with the small-diameter roll; and a rolling roll whose base end is pivoted downstream of the rolling roll and the small-diameter roll in the strip traveling direction, and which rolls the strip in a vertical plane parallel to the strip traveling direction. A swingable arm, and a strip that is pivotally supported on the arm in parallel with each of the rolls and passed between the small diameter roll and the rolling roll, are attached to the small diameter roll and the backing roll as required. A rolling apparatus characterized in that a roll is provided which can wrap the strip at a winding angle and can form a free span portion between the small diameter roll and the backing roll in which the strip does not come into contact with any of the rolls. 2. A small-diameter roll supported by a backing roll via an intermediate roll, and a small-diameter roll disposed on the side opposite to the intermediate roll of the small-diameter roll, the small-diameter roll being driven at different circumferential speeds, and cooperating with the small-diameter roll. A rolling roll that works to roll the strip, and a line passing through the rotational centers of the rolling roll and the small-diameter roll, and parallel to the strip traveling direction and perpendicular to the center of rotation near the position where the rolling roll and the small-diameter roll face each other. A rotary guide that can rotate in a plane, and a strip that is pivotally supported on the rotary guide in parallel with the rolls and passed between the small diameter roll and the rolling roll are required for the small diameter roll and the backing roll. A rolling apparatus characterized in that a deflector roll is provided which can wrap the strip at a winding angle of .about.100 .ANG.