JPS586564B2 - Atsuenki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rolling mill, mainly a cold rolling mill, which has features of a four-high rolling mill and a five-high rolling mill.

Conventionally, a four-high rolling mill consisting of two working rolls and two backing rolls has been widely used.

Furthermore, a five-high or six-high rolling mill called a Taylor mill incorporating small-diameter operating rolls is known.

Furthermore, in recent years, a rolling mill (Japanese Patent Application Laid-open No. 4-117) has been developed in which an intermediate roll configured to be movable in the axial direction is inserted between the working roll and the hold-up roll.
No. 7-29260, etc.) have been proposed.

The above-mentioned four-high rolling mill is widely used because of its simple and robust structure, but the diameter of the operating rolls cannot be made very thin, and therefore it is difficult to roll ultra-thin steel plates etc. However, there was a drawback that it was not possible to perform rolling efficiently.

In addition, in order to eliminate the drawbacks of the four-high rolling mill, the Taylor mill is a rolling mill that incorporates a small diameter working roll that does not drive, and drives a backing roll or a roll inserted in the middle. Although the rolling efficiency is improved by using this method, it requires a complicated mechanism to correct the bending of the roll, and is expensive.

In addition, a rolling mill that allows intermediate rolls to move in the axial direction to adjust the shape has the advantage of being able to roll steel plates with good shapes even when rolling ultra-thin steel plates, but the mechanism is complicated due to the roll movement mechanism. This has the drawback of making the rolling mill expensive.

In addition, in order to adjust the shape, a 5- or 6-high rolling mill (Japanese Unexamined Patent Publication No. 49-7
No. 6760) has also been proposed, but the configuration is complicated, and since the drive is performed using work rolls,
Since the work roll itself cannot be made very thin, the rolling efficiency is the same as that of a conventional four-high rolling mill.

The present invention has been made in view of the conventional circumstances, and is a rolling mill that has the simplicity of a 4-high rolling mill and has the advantage of being operable as a 5-high rolling mill with the working rolls having a smaller diameter as required. .

That is, the gist of the present invention is to replace two non-driving small-diameter rolls installed in independent chocks in the position of the upper or lower working roll of a four-high cold rolling mill, and drive one lower or upper working roll. The strip is rolled between a driven working roll and a small-diameter roll facing it, and the relationship between the pass line and the rolling direction and the roll rotation direction is operated as a 4-high rolling mill. This is the same rolling mill as in the case where the rolling mill is used.

The relationship between the diameters of each roll is as follows.

Dmin< D 4 + D4'≦Dmax where: Dmin = Minimum diameter of the working roll in a 4-high rolling mill Dmax = Maximum diameter of the working roll in a 4-high rolling mill D4 = Diameter of the small-diameter working roll D4'=Diameter of small diameter intermediate roll The feature of the present invention is that a normal 4-high cold rolling mill is changed to a 5-high rolling mill on a case-by-case basis, and the equivalent working roll diameter is smaller than that of a 4-high rolling mill. This reduces the rolling force and facilitates rolling of thin materials.

In cold rolling, if you want to reduce edge drop and improve plate thickness accuracy in the width direction, you can reduce the working roll diameter as described above, but it is possible to reduce the diameter while using a 4-high rolling mill. In this case, the lateral rigidity decreases and the advantage of reducing the rolling force due to the diameter reduction is canceled out.

Further, when rolling foil with a four-high rolling mill, the minimum thickness is determined by the diameter of the work roll and the rolling lubricant, and it is desirable to reduce the diameter of the work roll for rolling thinner foils.

In order to meet these demands, the present invention has developed a rolling mill (operating roll diameter: 360φ to 56mm) that functions as a 4-high rolling mill.
One upper or lower operating hole (approximately 0φ) is configured to be interchangeable with two small diameter rolls, and it also functions as a 5-high rolling mill.

Figure 1 shows the roll arrangement of a typical four-high rolling mill with working rolls driven and backing rolls not driven. 1 and 1' are working rolls, 2.2' are backing rolls, and 3 is a bending cylinder for shape control. shows.

In the case of operating roll drive, the rolls 1 and 1' are driven by a motor, and the difference in roll diameter is limited to about 1/100 mm.

FIG. 2 shows a five-high rolling mill in which the upper operating roll is replaced with a smaller diameter roll according to the present invention, and is driven by the lower operating roll 1'.

4 and 4' are non-driven small diameter rolls, and the relationship between their diameters is 1,
If the usage range of 1' is Dmin to Dmax, then Dm
It is expressed as in<D4+D4'<max.

The two small-diameter rolls are assembled into independent chocks 5 and 5', respectively, as shown in FIGS. 3A and 3B, and these can freely move in the vertical direction.

Leave the two small diameter rolls on top of the lower operating roll 1',
It has a structure that can be assembled into a mill stand using a recombination device such as a porter bar or a separate recombination trolley.

FIG. 4 shows the rolling state when a small diameter roll is installed on top, using the dimensions of the roll biting part.

This figure shows a case where a material having an entrance thickness h1 is rolled with a rolling force P and has an exit thickness h2, and D4 and D are the diameters of the upper and lower rolls.

In general, in cold rolling, the tension indicated by T1 and T2 is applied at both the inlet and the outlet, so there is no sheet warpage at the outlet, and since the sheet is flat, geometrically the biting projected length L is the same between the upper and lower rolls.

When the deformation resistance of the material is K, the rolling force P is expressed as approximately, but since the rolling force P is the same, the roll diameter and the amount of removal are approximately inversely proportional.

In other words, in FIG. 4, the amount of killing a by the upper working roll is larger than the killing amount b by the lower working roll.

In actual measurements, when using a rolling mill with D4/D = 1/2, the rolling force when the same amount of cut is taken is the same as when the diameter of the upper and lower working rolls is D.
In other words, it has been reduced to 70 times when using a 4-high rolling mill.

This can be interpreted as the roll diameter in equation (1) becoming smaller, and can be expressed as the equivalent roll diameter becoming smaller.

FIG. 5 is an exaggerated illustration of the rolling force distribution and roll deformation state in a typical conventional four-high cold rolling mill. When strip 6 is rolled with rolling force P, working roll 1,
It is a well-known fact that when the strip 1' is bent, the shape of the strip becomes wavy as shown in FIG. 6, and the cross section of the strip becomes thinner at the end as shown in FIG. 7, resulting in a so-called edge drop.

In addition, in order to flatten the shape of the strip during rolling, the working rolls 1 and 1' are given a roll profile with an initial convex curve as shown in Figure 8, or the roll profile shown in Figure 5, 3'.
The hydraulic cylinder between the operating rolls shown in Figure 2
A method of applying a reverse moment to the operating roll by applying F is also generally adopted.

FIG. 9 shows the case of a five-high rolling mill in which the equivalent roll diameter is reduced in order to reduce rolling force and edge drop in the present invention.

This is a 4-high cold rolling mill shown in Figures 1 and 5, in which non-driven small diameter rolls 4 and 4' are installed in the position of the upper working roll, and a 5-high cold rolling machine is driven by a single lower working roll 1'. It is a rolling mill.

Since the strip is rolled between the lower working roll 1' and the small diameter roll 4, the relationship between the pass line and the roll rotation direction and the rolling direction is the same as in the case of a four-high rolling mill.

In the case of cold rolling with the 5-high rolling mill shown in Fig. 9, the amount of cut with the same rolling force P by the small upper diameter roll 4 is naturally the case with work roll 1' when both the upper and lower work roll diameters are 4-high rolling mill. It can be made larger than that.

As a practical example, when obtaining the same amount of kill, as mentioned above,
When the diameter of the small diameter roll 4 is set to 1/2 of that of the lower work roll 1', the rolling force is reduced to a factor of 70 when the upper and lower work rolls have a large diameter.

This effect directly leads to a reduction in essi drop, but in reality, as shown in FIG. The resultant force of the outlet tension difference T1-T2 causes it to be pulled toward the inlet side, causing deflection, and this effect acts in a negative direction.

In order to cancel this, the difference between the frictional force Fw and the outlet tension T1-
This is done by adjusting the initial roll profile of the small diameter roll 4' which is subjected to the displacement of the small diameter roll 4 by the roll bending force F shown in FIG.

In Figure 9, rolling reaction force (rolling force) from the strip
is received by the highly rigid backing roll 2 via non-driving small diameter rolls 4 and 4', but as shown in Fig. 11, a feature of the 5-high rolling mill is that the small diameter roll 4' is rolled to match the strip width. By creating a stepped profile or a double curve profile as shown in Fig. 12, it is possible to release the bending moment at the end of the plate that is received from the small diameter roll 4 during rolling, and in addition to the large rigidity of the backing roll 2, The edge drop of the plate shape, especially at the edges, can be extremely reduced.

The relationship between the contact surface length L of the small diameter roll 4' with the backing roll and the strip width B in FIGS. 11 and 12 is B-L=0
~20mm is desirable.

In the present invention, each time the width B of the small diameter roll 4' is changed, the small diameter rolls 4, 4' and the chocks 5, 5' are both pulled out and assembled in advance, as shown in FIG.

Small diameter rolls and chokes 4' with different roll profiles
, 5'.

During rolling, it is possible to control the shape to reduce edge drops by using it in combination with roll bending, and it is possible to roll thin steel sheets without edge drops.

This is particularly effective in rolling high-carbon steel plates with high deformation resistance, and brings about a significant improvement in yield.

Other rolling materials can be rolled using a robust four-high rolling mill, and more appropriate rolling conditions can be achieved using the same equipment.

As described above, the present invention enables advantageous thin plate rolling to be carried out with low equipment costs, and is extremely useful industrially.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the configuration of a four-high rolling mill according to the present invention,
FIG. 2 is an explanatory diagram showing the configuration of a 5-high rolling mill, FIGS. The figure is an explanatory diagram showing the rolling state when small-diameter rolls are incorporated, Fig. 5 is an explanatory diagram exaggerating the distribution of rolling force and the deformation state of the rolls in a four-high rolling mill, and Fig. 6 is the shape FIG. 7 is a cross-sectional view in the width direction,
Fig. 8 is an explanatory diagram showing an example of a roll profile, Fig. 9 is an explanatory diagram showing a rolling state in a five-high rolling mill according to the present invention, and Fig. 10 is an explanatory diagram showing a rolling state when viewed from the axial direction of the roll. FIGS. 11 and 12 are explanatory views showing the operation, and are explanatory views showing the rolling state when the intermediate small diameter roll is changed to match the width of the rolled material. 1... Upper operating roll, 1'... Lower operating roll, 2...
...Upper reserve roll, 2'...Lower reserve roll, 4...
Small diameter roll (operating roll), 4'... Small diameter roll (intermediate roll), 5,5'... Roll chock, 6...
Rolled material.

Claims (1)

[Claims] 1. It functions as a four-high rolling mill, consisting of a pair of upper and lower backing rolls and a pair of upper and lower working rolls that are driven between the backing rolls. This rolling mill is configured to be compatible with two small diameter rolls that meet the conditions, and functions as a 5-high rolling mill. Dmin<D4 + D4'≦Dmax Where: Dmin = Minimum diameter of the working roll in a 4-high rolling mill Dmax = Maximum diameter of the working roll in a 4-high rolling mill D4 = Diameter of the small diameter roll (working roll) D4 ′ = Diameter of small diameter roll (intermediate roll)