JPH03502428A - rolling mill stand - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] rolling mill stand industrial field The present invention relates to rolling technology, and more particularly to rolling mill stands.

Conventional technology What is currently clear is that an equal amount of displacement can be obtained with respect to the plane passing through the axis of the work roll. The upper and lower bank unrolls installed so that the There is no difference between the upper and lower longitudinal stiffness of the stand with respect to the opening. This causes an imbalance. This has a negative impact on the quality of rolled products. Main drive motor, line shaft, gear coupling, pinion stand The drive mechanism, splines, and sleeves attached to the neck of the work roll. This reduces the reliability of the rolling mill's power transmission device, which consists of mating rolls and the like.

The opening between the upper and lower work rolls will be referred to as the "roll gap" below. Make it.

If the torque distribution between both rolls is uneven, the rolling torque will not be transmitted to the upper and lower work rolls. This results in an imbalance in the loads acting on the drive.

If there is a difference in rigidity between the upper and lower parts of the stand relative to the roll gap, roll erosion will occur. Up and down work in the area of the side gap between the chock and the housing at the moment of engagement A mismatch occurs between the longitudinal displacements of the rolls.

Irregular patterns of slip areas are formed where the metal is deformed. i.e. , the speed of the metal is faster than the speed of the roll (and in other regions The opposite situation occurs in .

This results in uneven distribution of rolling torque and overloading of the roll drive. As a result, the reliability of the power transmission device of the stand is impaired as a whole.

Apart from this, different longitudinal displacements of the rolls cause the rolls to move at different circumferential speeds. It will be rotated. In this case, the biting force of the roll becomes smaller, so Increased chance of strip blockage and grow-back k) becomes more likely to occur.

As a conventionally known rolling mill stand, for example, USSR Patent No. 799,842 (SO- A 799,842), this rolling mill stand has upper and lower It has a roll housing that accommodates the work roll chock, and the upper and lower work The industrial rolls are installed in the roll housing with a gap between them. The longitudinal axes of the two are arranged in the same plane. Also, the same low The chocks of the upper and lower banked up rolls located inside the housing are Arranged so that the longitudinal axis lies in the same plane as the axis of the work roll .

Rolls configured in this way prevent the unstable balance of the work rolls during rolling operations. cause a state of When the strips bite, the work rolls Longitudinal displacement in the area of unavoidable side gaps between shock and housing The work roll, which is displaced in the longitudinal direction at the moment of zero biting, has different circumferential speeds. Different rolling torques act on the zero work roll, which starts rotating at is repeatedly overloaded. For this reason, the durability of the entire rolling mill power transmission system is affected. adversely affected.

In addition, the work rolls are unstable during rolling work and the work rolls are close to each other. Horizontal displacement causes growback, which impairs the quality of the product. .

Another known rolling mill stand is the one disclosed in Soviet Patent No. 789.170. The rolling mill stand consists of a roller that houses the chocks of the upper and lower work rolls. The upper and lower work rolls are installed with a gap between the roll housings. mounted within the housing so that their longitudinal axes lie in the same plane. It is composed of Also, the upper and lower batteries located inside the roll housing are also Quan roll chocks have their longitudinal axes directed opposite to the rolling direction. is displaced an equal distance away from the plane passing through the longitudinal axis of the work roll. It is arranged so that it can be done.

The horizontal component of the reaction force in each bank unroll (this component is applied to the work roll) (which causes play when placing the back unroll as described above). The chock of each work roll is pressed against the housing, which causes the The horizontal displacement of the work roll is: It continues to exist even when biting, but the amount of displacement is greater than the amount of displacement in the stand mentioned above. It's also small.

However, the longitudinal axis of the upper and lower bank unrolls is the same as the longitudinal axis of the work roll. Take the upper and lower backup rolls so that they are displaced equidistantly from the plane passing through the direction axis. Despite the configuration in which the Due to the different stiffness of the upper and lower parts of the housing, the area of the side gap between the chock and the housing This results in unequal longitudinal displacements of the upper and lower work rolls within.

Slip occurring in the upper and lower work rolls at a different speed than the strip being rolled Due to this, uneven loads and overloads are applied to the roll drive device, which affects the operation of the rolling mill. The overall durability of the force transmission device is impaired.

The difference in the slip speed of the upper and lower work rolls relative to the strip causes roll wear. This can lead to strip clogging and reduced product quality. Growback is caused.

Summary of the invention Therefore, the main object of the present invention is to minimize the glow bank and improve the stand driving device. Providing a rolling mill stand with rolls mounted for improved durability. It's there.

The above object of the present invention is to provide a rolling mill stand having the following configuration, that is, a housing. The housing has a chip for the upper work roll and the lower work roll. a shock is housed and the work rolls have their longitudinal axes coplanar. The upper and lower bars are arranged with a gap between them. The bank-up roll further includes a chock for the backup roll. their longitudinal axes are spaced apart from a plane passing through the longitudinal axes of the upper and lower work rolls. In the rolling mill stand arranged in the tick with the upper and lower Bank-up rolls have their longitudinal axes parallel to the longitudinal direction of the upper and lower work rolls. The upper and lower banks are arranged to be displaced by a distance consisting of a plane extending the adaxial line, and the upper and lower banks Each of the displacement amounts of the am rolls corresponds to the gap between the upper and lower work rolls. be inversely proportional to the stiffness of the appropriate part of the rolling mill stand with respect to the rolling mill stand, i.e. to change as follows, δ1/δ8=S friend/S+ here, δ1 is the upward backup from the plane passing through the longitudinal axes of the upper and lower work rolls; roll displacement amount, δ, is the downward backup from the plane passing through the longitudinal axes of the upper and lower work rolls; roll displacement amount, S, is the stiffness of the upper part of the rolling mill stand with respect to the gap between the upper and lower work rolls; , Sf is the rigidity of the lower part of the rolling mill stand between the gap between the upper and lower work rolls; , This is achieved by a rolling mill stand featuring:

Rolls constructed according to the method of the present invention have a bank-up profile suitable for working rolls. generates different horizontal components of reaction force at the stand, and Under rigid conditions, to produce equal horizontal displacement of the upper and lower work rolls. It has become.

The slip areas formed on the upper and lower work rolls at the metal deformation point are equally large. It's going to be. Therefore, the rolling torque on the rolls is at a common level, and the rolling torque on the rolls is at a common level. The load acts evenly on both sides of the drive, eliminating overloads. Also, strip Because the strip bites without any hindrance, it prevents clogging of the strip and Therefore, the quality of rolled products can be improved. Ru.

The rolling mill stand of the present invention reduces growback and improves rolling accuracy. In addition, the reliability of the rolling mill stand drive device can be improved. Ru.

Brief description of the drawing In order to be able to understand the invention better, a rolling mill stand according to the invention will be briefly described. Preferred embodiments of the invention will now be described with reference to the accompanying drawings, in which: FIG.

Example The rolling mill stand provided according to the invention has a housing 1, The roll 1 has an upper work roll 3 and a lower work roll 3 separated by a gap. The handle 2 that constitutes the support of the work roll 4 and the upper bank unroll 6 and the chock 5 constituting the support of the lower bank up roll 7 are accommodated. has been done. The respective longitudinal axes 8 of the upper and lower work rolls 3.4 lie in the same plane. It is located in

The longitudinal axis 9 of the upper bank-up roll 6 and the lower bank-up roll 7 The longitudinal axis 10 of is a plane passing through the longitudinal axis 8 of the upper and lower work rolls 3.4. The upper bank up is displaced by a distance in the opposite direction to the rolling direction. The displacement amount δ of the roll 6 is different from the displacement amount δ of the lower back unroll 7. There is.

Fluid-operated stationary cylinder II attached to the tip 2 of the lower work roll 4 so that the work roll 3 is pressed against the bank up roll 6.7. It has become.

The displacement amounts δ1 and δ8 of the upper and lower bank up rolls 6.7 correspond to the upper and lower work, respectively. Stiffness S,, S of the part 12.13 of the stand relative to the gap between the rolls 3.4 , will be selected based on.

As a result of the research, the stiffness S of the upper part 12 and the stiffness S8 of the lower part 13 of the stand are It has been found that the dynamic loads generated in the drive system (not shown) of Rule 3.4 are affected. The shadow @ (effect) of the taraya is due to the dynamic load acting on the drive device of the work roll 3.4. Linear stiffness S5, S! moments of elasticity determined for of elastLcity) when calculating the reduced torsional stiffness S1, Regarding S4, the upper part 12 and lower part of the stand separated by a roll gap By reducing the linear rigidity S, SR of the portion 13, the upper and lower working loca- tions are reduced. Evaluated against a Rule 3.4 drive.

According to another study1, the reduced torsional stiffness can be determined from the following relationship: I know it.

S, = r” Lβ, S, (1) Sa = r (2) Here, r is the radius of work roll 3 or 4; L is the nip angle (biting angle), β1 and β2 are the center of the upper and lower work rolls 3.4 and the center of the backup roll 6.7. It is the angle that the line passing through the center makes with the horizontal.

Bringing the moments of elasticity in the upper and lower drives to a common level, thus reducing the Make the speed of the work roll 3.4 equal to the speed of the strip at the point of metal deformation. requires a step to equalize the reduced stiffnesses Ss and Sa.

By comparing the relationship between equations (1) and (2) above, S t / S + - β1 /β, (3) can be obtained.

Since the angles β1 and β are small, they can be considered as follows. That is, β1#δ+ /’r6”r, β2#δ2/r, +r (4) Here, ro is the radius of backup roll 6 or 7, r is the radius of work roll 3 or 40 It is.

Substituting the above equation (4) into equation (3), we get δ, /δt = Sx / St To obtain (5) I can do it. That is, according to the present invention, the bank unloading for the work roll 3.4 is The displacements δ3 and δ2 of the prowl 6.7 are determined by the stand suitability with respect to the roll gap. The stiffness St of 2.13 changes in inverse proportion to St.

The rolling mill stand of the present invention operates as follows.

The friction caused by the contact between the two working rolls 3.4 and the strip at the moment of biting Due to the frictional force, the two work rolls 3.4 are forced to move between the tips 2 and the housing 1. In the region of the lateral gaps between them, they are longitudinally displaced in a direction opposite to the rolling direction.

These different displacement amounts δ1 and δ2 are related to the roll gap during the transient process. Therefore, the stiffness S1 of the appropriate part 12.13 of the stand changes in inverse proportion to St. Therefore, the work roll 3.4 is located in the area of the side gap between the tick 2 and the housing l. is displaced by the same distance. slip area (i.e. of upper and lower work rolls 3.4) The region where the velocity is faster than the velocity of the strip at the point where the strip is deformed. area or slowing area) are equal in size, so that the drive of the work roll 3.4 is The dynamic equipment will be able to handle the same dynamic load. This reduces drive overload. In addition, the operational reliability of the power transmission device of the stand is improved as a whole.

As mentioned above, the size of the slip area on the upper and lower work rolls 3.4 should be made equal. This increases the stability of the bite and reduces the possibility of strip clogging. . In addition, growback is reduced and the quality of rolled products is improved.

As an example, for the four high stands of a hot wide rolling mill, the back unroll Let us determine the relationship between the displacement amounts δ, , δ, in 6.7.

Practical experience that the displacement δ of the lower backup roll 7 is 10 m. Judging from, the rigidity S of the upper part 12 of the stand is s, −7,7・10” Determine N/m. Similarly, the stiffness S of the lower part 13 of the stand is S! −1,4 98・10"N/-. Substituting these values into equation (5), δ+" 19.5+m- can be obtained.

According to experiments, the quality of rolled products can be improved by setting δ and 62 in the same relationship. It is possible to improve the quality and ensure the operational reliability of the power transmission device of the stand. Wear.

Industrial applicability The present invention is particularly effective when used in hot and cold wide string rolling mills. Ru.

According to the present invention, glowback can be reduced by about 25 to 30%, and the roll drive device The dynamic load can be reduced by about 30 to 40%. Also, it practically eliminates overload. and improves the operational reliability of the power transmission system of the stand by approximately 20-25%. can be raised.

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Claims (1)

[Claims] The housing (1) has an upper work roll (1) inside the housing (1). 3) and the chock (2) of the lower work roll (4) are accommodated, and the work The rolls (3, 4) are arranged such that their longitudinal axes (8) lie in the same plane. The upper and lower backup rolls are placed with a gap between them. It further has a chock (5) of (6, 7), and the backup roll (6, 7), these longitudinal axes (9, 10) are connected to the upper and lower work rolls (3, 4). in said chock (5) at a distance from a plane passing through the longitudinal axis (8) of the In the rolling mill stand, the upper and lower back rolls (6, 7) are such that their longitudinal axes (9, 10) are the lengths of the upper and lower work rolls (3, 4). arranged at a distance from a plane passing through the manual axis (8), Each of the displacement positions (δ1, δ2) of the lower backup rolls (6, 7) is , the rolling mill stand with respect to the gap between the upper and lower work rolls (3, 4). is inversely proportional to the stiffness of the appropriate part (12 or 13) of to become δ1/δ2=S2/S1 here, δ1 is the height above the plane passing through the longitudinal axis (8) of the upper and lower work rolls (3, 4). The displacement position, δ2, of the upper back up roll (6) is the upper and lower work rolls (3, 4). Displacement of the lower back-up roll (7) from a plane passing through the longitudinal axis (8) of S1 is the rolling mill stand regarding the gap between the upper and lower work rolls (3, 4). The stiffness of the upper part (12) of the roll, S2 is the gap between the upper and lower work rolls (3, 4). The rigidity of the lower part (13) of the rolling mill stand with respect to A rolling mill stand featuring: